Mangala Fossae

NASA Image and Video Library

2015-05-22

The linear wall at the bottom of this image from NASA 2001 Mars Odyssey spacecraft is a fault. The linear depression caused by faulting is part of a long depression called Mangala Fossae. Orbit Number: 58979 Latitude: -17.9823 Longitude: 210.806 Instrument: VIS Captured: 2015-04-01 00:54 http://photojournal.jpl.nasa.gov/catalog/PIA19468

Measurement of Lacrimal Sac Fossa Using Orbital Computed Tomography.

PubMed

Kang, Dongwan; Park, Jinhwan; Na, Jaehoon; Lee, Hwa; Baek, Sehyun

2017-01-01

To evaluate the clinical usefulness of measuring the lacrimal sac fossa length using orbital computed tomography in normal Koreans. The authors retrospectively evaluated 140 patients (70 males and 70 females) who underwent orbital computed tomography at Guro Hospital and who had no history of orbital disease or orbital trauma. Computed tomography scans of the right orbit, including the proportion of the lacrimal bone and maxillary bone that comprise the lacrimal sac fossa, were evaluated at 3 different axial planes (lower, middle, and upper levels). Additionally, the mid-point thickness and maximum thickness of the maxillary bone were measured. Finally, the authors also evaluated the relationship between nasal bone height and maxillary bone thickness in the lacrimal sac fossa. Maxillary bone thickness in the lacrimal sac fossa was thicker in males than in females at mid-point thickness and maximum thickness (P < 0.05). However, there was no significant difference in the size of the lacrimal sac fossa and the proportion of the maxillary bone between males and females.In comparisons between maxillary cross-sections, bone thickness was greater toward the upper level of the lacrimal sac fossa (P = 0.008), and the proportion of the maxillary bone was also greater (P = 0.006).Aging had a significant positive correlation with maxillary bone thickness at all 3 axial planes (P < 0.05), but there was no relationship between age and maxillary bone proportion. Nasal bone height and maxillary bone thickness were also not significantly related. In comprising the lacrimal sac fossa, the maxillary bone accounted for a bigger proportion than the lacrimal bone. Male maxillary bone thickness was greater than female thickness. The authors also observed that maxillary bone thickness increased toward the upper areas of the lacrimal sac fossa and with increasing subject age. Understanding the form and variation of a normal lacrimal sac fossa is helpful for preparing for a

Medusae Fossae #2

NASA Technical Reports Server (NTRS)

1998-01-01

Extensive wind-swept plains of the Medusae Fossae formation on Mars. This southern subframe image, frame 3104, is of a 3.0 x 4.7 km area centered near 2.0 degrees north, 163.8 degrees west.

Figure caption from Science Magazine

Medusae Fossae #1

NASA Technical Reports Server (NTRS)

1998-01-01

Extensive wind-swept plains of the Medusae Fossae formation on Mars. This northern subframe image, frame 3104, is of a 3.0 x 4.7 km area centered near 2.4 degrees north, 163.8 degrees west.

Figure caption from Science Magazine

Claritas Fossae

NASA Image and Video Library

2016-10-05

The linear depressions in this VIS image are some of the numerous graben that make up Claritas Fossae. Graben form when two faults cause a block of material to be dropped to a lower elevation. Orbit Number: 65197 Latitude: -35.7709 Longitude: 251.553 Instrument: VIS Captured: 2016-08-25 03:51 http://photojournal.jpl.nasa.gov/catalog/PIA21004

Mangala Fossa

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 29 May 2002) The Science Today's THEMIS release captures Mangala Fossa. Mangala Fossa is a graben, which in geologic terminology translates into a long parallel to semi-parallel fracture or trough. Grabens are dropped or downthrown areas relative to the rocks on either side and these features are generally longer than they are wider. There are numerous dust devil trails seen in this image. In the lower portion of this image several dust devil tracks can be seen cutting across the upper surface then down the short stubby channel and finally back up and over to the adjacent upper surface. Some dust avalanche streaks on slopes are also visible. The rough material in the upper third of the image contains a portion of the rim of a 90 km diameter crater located in Daedalia Planum. The smooth crater floor has a graben (up to 7 km wide) and channel (2 km wide) incised into its surface. In the middle third and right of this image one can see ripples (possibly fossil dunes) on the crater floor material just above the graben. The floor of Mangala Fossa and the southern crater floor surface also have smaller linear ridges trending from the upper left to lower right. These linear ridges could be either erosional (yardangs) or depositional (dunes) landforms. The lower third of the scene contains a short stubby channel (near the right margin) and lava flow front (lower left). The floor of this channel is fairly smooth with some linear crevasses located along its course. One gets the impression that the channel floor is mantled with some type of indurated material that permits cracks to form in its surface. The Story In the Daedalia Plains on Mars, the rim of an old eroded crater rises up, a wreck of its former self (see context image at right). From the rough, choppy crater rim (top of the larger THEMIS image), the terrain descends to the almost smooth crater floor, gouged deeply by a trough, a channel, and the occasional dents of small, scattered craters. The deep

Posterior fossa tumor

MedlinePlus

... Most tumors of the posterior fossa are primary brain cancers. They start in the brain, rather than spreading from somewhere else in the ... nausea, vomiting, or vision changes. Alternative Names ... JF, Hollander AB, Alonso-Basanta M, et al. Cancer of the central nervous system. In: Niederhuber JE, ...

Nili Fossae

NASA Image and Video Library

2016-07-20

Nili Fossae is a large band of parallel graben located to the northeast of Syrtis Major. The graben in this image from NASA 2001 Mars Odyssey spacecraft were formed by tectonic activity, with faulting that creates the linear depression. Orbit Number: 64105 Latitude: 23.3115 Longitude: 78.6126 Instrument: VIS Captured: 2016-05-27 05:24 http://photojournal.jpl.nasa.gov/catalog/PIA20785

Glenoid fossa responses to mandibular lateral shift in growing rats.

PubMed

Liu, Chang; Kaneko, Sawa; Soma, Kunimichi

2007-07-01

To evaluate the morphological and histological responses of the glenoid fossa to mandibular lateral shift in growing rats. A resin plate was placed on the upper incisors of 4-week-old rats in the experimental groups to displace the mandible to the left during closure. The rats were killed after 2, 4, 8, and 12 weeks. The morphometric measurements were performed on dry skulls, and tissue blocks were processed for periodic acid and Schiff's reagent (PAS) staining to examine the new bone formation. Gross measurements showed asymmetry in both the position and size of the fossae between the two sides after 4 weeks of lateral shift. The glenoid fossa on the ipsilateral side was repositioned relatively backward, outward and upward compared with the contralateral side and control group, whereas the fossa on the contralateral side was relocated relatively forward and downward compared with the control group. The length of the fossa was smaller on the ipsilateral side than on contralateral side and control group. At 2 weeks, the amount of newly formed bone in the posterior region of the fossa was higher in the experimental group than the control group. It is suggested that the mandibular lateral shift causes asymmetry in the position and size of the glenoid fossa and that this phenomenon can be related to different bilateral directional new bone formation in the posterior region.

Tissue interaction is required for glenoid fossa development during temporomandibular joint formation

PubMed Central

Wang, Ying; Liu, Chao; Rohr, Joseph; Liu, Hongbing; He, Fenglei; Yu, Jian; Sun, Cheng; Li, Lu; Gu, Shuping; Chen, YiPing

2011-01-01

The mammalian temporomandibular joint (TMJ) develops from two distinct mesenchymal condensations that grow towards each other and ossify through different mechanisms, with the glenoid fossa undergoing intramembranous ossification while the condyle being endochondral in origin. In this study, we used various genetically modified mouse models to investigate tissue interaction between the condyle and glenoid fossa during TMJ formation in mice. We report that either absence or dislocation of the condyle results in an arrested glenoid fossa development. In both cases, glenoid fossa development was initiated, but failed to sustain, and became regressed subsequently. However, condyle development appears to be independent upon the presence of the forming glenoid fossa. In addition, we show that substitution of condyle by Meckel’s cartilage is able to sustain glenoid fossa development. These observations suggest that proper signals from the developing condyle or Meckel’s cartilage are required to sustain the glenoid fossa development. PMID:21953591

Nili Fossae - False Color

NASA Image and Video Library

2016-04-27

The THEMIS camera contains 5 filters. The data from different filters can be combined in multiple ways to create a false color image. This image from NASA 2001 Mars Odyssey spacecraft shows part of Nili Fossae.

Assessment of growth dynamics of human cranium middle fossa in foetal period.

PubMed

Skomra, Andrzej; Kędzia, Alicja; Dudek, Krzysztof; Bogacz, Wiesław

2014-01-01

Available literature analysis demonstrated smallness of studies of cranial base. The goal of the study was to analyse the medial fossa of the human cranium in the foetal period against other fossae. Survey material consisted of 110 human foetuses at a morphological age of 16-28 weeks of foetal life, CRL 98-220 mm. Anthropological, preparation method, reverse method and statistical analysis were utilized. The survey incorporated the following computer programmes: Renishaw, TraceSurf, AutoCAD, CATIA. The reverse method seems especially interesting (impression with polysiloxane (silicone elastomer of high adhesive power used in dentistry) with 18 D 4823 activator. Elicited impression accurately reflected complex shape of cranium base. On assessing the relative rate of cranium medial fossa, the rate was found to be stable (linear model) for the whole of the analysed period and is 0.19%/week, which stands for the gradual and steady growth of the middle fossa in relation to the whole of the cranium base. At the same time, from the 16th till 28th week of foetal life, relative volume of the cranium middle fossa increases more intensively than cranium anterior fossa, whereas the cranium middle fossa volume as compared with the cranium posterior fossa is definitely slower. In the analysed period, the growth rate of the cranium base middle fossa was bigger in the 4th and 5th weeks than in the 6th and 7th weeks of foetal life. The investigations revealed cranium base asymmetry of the left side. Furthermore, the anterior fossae volume on the left side is significantly bigger than the one of the fossae on the right side. Volume growth rate is more intensive in the 4th and 5th than in the 6th and 7th weeks of foetal life. In the examined period, the relative growth rate of cranium base middle fossa is 0.19%/week and it is stable - linear model. The study revealed correlations in the form of mathematical models, which enabled foetuses age assessment.

[Anatomy and malformations of the posterior cranial fossa].

PubMed

Struffert, T

2016-11-01

Many important structures are located in the confined space within the posterior cranial fossa. This article describes the main aspects of the anatomy. As a uniform classification of malformations of the posterior cranial fossa does not exist the main syndromes, such as Chiari malformations, zerebellar hypoplasia and dysplasia are discussed separately.

Claritas Fossae

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 20 June 2002) The Science The eastern rim of this unnamed crater in Claritas Fossae is very degraded. This indicates that this crater is very ancient and has been subjected to erosion and subsequent bombardment from other impactors such as asteroids and comets. One of these later (younger) craters is seen in the upper right of this image superimposed upon the older crater rim material. Note that this smaller younger crater rim is sharper and more intact than the older crater rim. This region is also mantled with a blanket of dust. This dust mantle causes the underlying topography to take on a more subdued appearance. The Story Not every crater on Mars has a name. The one in this image doesn't. What would you name it if you could? That's what planetary scientists ask themselves when they come across such features. If they think of a good name, they can submit it for approval to a group of world astronomers who are members of the International Astronomical Union. There are special rules, though, so not any name can be selected. The selection committee especially wants to make sure that all world cultures are represented. While this crater may not have a name, the region it lies in does. It is called Claritas Fossae. 'Claritas' is the Latin word for 'bright.' 'Fossae' are long, narrow, shallow depressions that mark the region. You can see these best in the context image to the right. You can tell just by looking at this crater that it is very ancient. Its rim is very degraded from erosion and bombardment from other impactors such as asteroids and comets. Compare its roughened rim to the smoother outline of the small crater on the rim's edge (upper right). The smoother rim of the small one means that it is considerably younger than its older, choppier neighbor. You know it was certainly created after the large crater because it lies on top of the rim. Other than the old and young generations of craters, the surface looks pretty uniform in hue and perhaps even

Sacra Fossae

NASA Image and Video Library

2018-04-19

Located on the western margin of Lunae Planum, Sacra Fossae is a group of linear depressions. The right angle turns and uniform width seen in this VIS image indicate that these channels were formed by faulting rather than liquid flow. Two bounding faults with a down-dropped interior are called graben. Orbit Number: 71244 Latitude: 17.7623 Longitude: 288.309 Instrument: VIS Captured: 2018-01-05 09:06 https://photojournal.jpl.nasa.gov/catalog/PIA22373

Temporal fossa hemangiopericytoma: a case series.

PubMed

Heiser, Marc A; Waldron, James S; Tihan, Tarik; Parsa, Andrew T; Cheung, Steven W

2009-10-01

Review clinical experience with temporal fossa hemangiopericytomas (HPCs). Retrospective case series review. Tertiary referral center. Intracranial HPCs within the temporal fossa. Craniotomy for either subtotal or gross total tumor excision. Determination of clinical outcome (alive with no evidence of disease, alive with disease, and died of disease). Five cases of HPC involving the temporal fossa were treated at our tertiary referral center for the period from 1995 to 2008. All but 1 patient were men. The age of presentation ranged from 31 to 62 years, and duration of follow-up ranged from 8 to 153 months. Clinical presentation was protean; headache was the most common symptom. Gross total tumor excision was achieved in 2 patients, whereas subtotal tumor excision was achieved in 3 patients. Reasons for subtotal resection included excessive intraoperative blood loss and inextricable tumor. Histologically, all tumors were composed of tightly packed, randomly oriented (jumbled-up) tumor cells with little intervening collagen. CD34 staining mostly highlighted the vascular background. One patient died of disease, 2 patients were alive with disease, and 2 patients had no evidence of disease. Management of temporal fossa HPC is challenging because clinical presentation is often late, and extent of tumor excision is constrained by vital structures in the cranial base and intracranial contents. A multidisciplinary approach with neurosurgery and neurotology undertaken to achieve the most complete tumor resection possible, whereas minimizing morbidity are likely to confer a longer period of symptom-free survival and improves curability of these difficult lesions.

Recurrent hemorrhage in hemangioblastoma involving the posterior fossa: Case report

PubMed Central

Marvin, Eric; Akhter, Asad S.; Coppens, Jeroen R.

2017-01-01

Background: Hemangioblastomas (HGBs) are the most common primary intra-axial posterior fossa tumor in adults. Although spontaneous hemorrhage of these tumors is exceedingly rare, despite their vascular nature, we describe a case of recurrent hemorrhage with associated tonsillar herniation, and demonstrate that a surgical approach can provide a suitable outcome. Case Description: A 54-year-old female with von Hippel-Lindau (VHL) syndrome presented with acute loss of consciousness and Glasgow Coma Scale (GCS) was 4. Computed tomographic (CT) images demonstrated large volume subarachnoid hemorrhage of the posterior fossa with intraventricular extension and intraparenchymal hemorrhage involving the right cerebellar tonsil. Magnetic resonance imaging (MRI) displayed three lesions in the posterior fossa, two near the hemorrhage site. Patient underwent suboccipital craniectomy with a decent recovery followed by radiosurgery as she refused resection. A second hemorrhage occurred ultimately prompting surgical resection of the three posterior fossa lesions, with a reasonable postoperative course. Conclusion: Hemorrhage of HGBs of the posterior fossa can present in conjunction of tonsillar herniation. Re-hemorrhage appears to be likely if prior acute hemorrhage has occurred. A stepwise approach of surgical decompression and resection may provide the best outcome. PMID:28713626

Post-traumatic osteochondral ''loose body'' of the olecranon fossa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bassett, L.W.; Mirra, J.M.; Forrester, D.M.

1981-12-01

Three cases of intra-articular osteochondral bodies with the olecranon fossa are reported. All patients had had severe trauma to the elbow, and in each case an osteochondral fragment, nourished by the synovial fluid, became enlarged and finally lodged within the fossa. The radiological and pathological features and presumed pathogenesis are described.

Lateral transzygomatic middle fossa approach and its extensions: surgical technique and 3D anatomy.

PubMed

Chotai, Silky; Kshettry, Varun R; Petrak, Alex; Ammirati, Mario

2015-03-01

Various approaches to lesions involving the middle fossa and cavernous sinus (CS), with and without posterior fossa extension have been described. In the present study, we describe the surgical technique for the extradural lateral tranzygomatic middle fossa approach and its extensions, highlight relevant 3D anatomy. Simulations of the lateral transzygomatic middle fossa approach and its extensions were performed in four silicon-injected formalin fixed cadaveric heads. The step-by-step description and relevant anatomy was documented with 3D photographs. The lateral transzygomatic middle fossa approach is particularly useful for lesions involving the middle fossa with and without CS invasion, extending to the posterior fossa and involving the clinoidal region. This approach incorporates direct lateral positioning of patient, frontotemporal craniotomy with zygomatic arch osteotomy, extradural elevation of the temporal lobe, and delamination of the outer layer of the lateral CS wall. Extradural drilling of the sphenoid wing and anterior clinoid process allows entry into the CS through the superior wall and exposure of the clinoidal segment of the ICA. Posteriorly, drilling the petrous apex allows exposure of the ventral brainstem from trigeminal to facial nerve and can be extended to the interpeduncular fossa by division of the superior petrosal sinus. The present study illustrates 3D anatomical relationships of the lateral transzygomatic middle fossa approach with its extensions. This approach allows wide access to different topographic areas (clinoidal region and clinoidal ICA, the entire CS, and the posterior fossa from the interpeduncular fossa to the facial nerve) via a lateral trajectory. Precise knowledge of technique and anatomy is necessary to properly execute this approach. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of Rapid Maxillary Expansion on Glenoid Fossa and Condyle-Fossa Relationship in Growing Patients (MEGP): Study Protocol for a Controlled Clinical Trial

PubMed Central

Ghoussoub, Mona Sayegh; Rifai, Khaldoun; Garcia, Robert; Sleilaty, Ghassan

2018-01-01

Aims and Objectives: Rapid maxillary expansion (RME) is an orthodontic nonsurgical procedure aiming at increasing the width of the maxilla by opening mainly the intermaxillary suture in patients presenting a transverse maxillary skeletal deficiency. The objectives of the current prospective controlled clinical and radiographic study are to evaluate the hypothesis that RME in growing patients will result in radiographic changes at the level of interglenoid fossa distance, condyle-fossa relationship, and nasal cavity widths compared to the group who received no treatment initially and served as untreated control. Materials and Methods: In this prospective controlled clinical and radiographic study, forty healthy growing patients selected from a school-based population following a large screening campaign, ranging in age between 8 and 13 years, presenting a maxillary constriction with bilateral crossbite, and candidates for RME are being recruited. The first group will include participants willing to undergo treatment (n = 25) and the other group will include those inclined to postpone (n = 15). Results: The primary outcome is to compare radiologically the interglenoid fossa distance and the condyle-fossa relationship; nasal cavity width will be a secondary outcome. A multivariable analysis of Covariance model will be used, with the assessment of the time by group interaction, using age as covariate. The project protocol was reviewed and approved by the Ethics Committee of the Lebanese University, National Institute in Lebanon (CUEMB process number 31/04/2015). The study is funded by the Lebanese University and Centre National de Recherche Scientifique, Lebanon (Number: 652 on 14/04/2016). Conclusion: This prospective controlled clinical trial will give information about the effect of RME on the glenoid fossa and condyle-fossa relationship and its impact on the nasal cavity width. Trial Registration: Retrospectively registered in BioMed Central (DOI10.1186/ISRCTN

Bony eminence on the middle cranial fossa corresponding to the temporomandibular joint.

PubMed

Tsunoda, Atsunobu; Sumi, Takuro; Shirakura, Satoshi; Kishimoto, Seiji; Akita, Keiichi

2007-07-01

We report a nameless bony eminence over the temporomandibular joint (TMJ) and its possible clinical significance. Forty-two half heads of 21 UK Caucasian cadavers (61-95 years old, mean 84.3 +/- 8.2 years, male:female = 11:10) were used to investigate the surface of the middle cranial fossa (MCF) over the TMJ. The thickness of the bony roof of the glenoid fossa was also measured. A bony eminence over the glenoid fossa was observed in half of the specimens. Some showed a complete oval bulge, which completely reflected the contour of the glenoid fossa. The others showed a bony bulge, which partially reflected that contour. The mean (+/-SD) thickness of the bone in the roof of glenoid fossa was 1.5 +/- 1.2 mm. The mean bony thickness of specimens showing the eminence was 0.8 +/- 0.5 mm, whereas it was 2.3 +/- 1.2 mm in specimens without an eminence. These differences were statistically significant (P < 0.01). The osteological features we describe may be relevant to certain clinical problems. Traumatic dislocation of mandibular condyle, for example, might relate to a weakness of the glenoid fossa. Copyright 2006 Wiley-Liss, Inc.

[Cochlear implantation through the middle fossa approach].

PubMed

Szyfter, W; Colletti, V; Pruszewicz, A; Kopeć, T; Szymiec, E; Kawczyński, M; Karlik, M

2001-01-01

The inner part of cochlear implant is inserted into inner ear during surgery through mastoid and middle ear. It is a classical method, used in the majority cochlear centers in the world. This is not a suitable method in case of chronic otitis media and middle ear malformation. In these cases Colletti proposed the middle fossa approach and cochlear implant insertion omitting middle ear structures. In patient with bilateral chronic otitis media underwent a few ears operations without obtaining dry postoperative cavity. Cochlear implantation through the middle fossa approach was performed in this patient. The bone fenster was cut, temporal lobe was bent and petrosus pyramid upper surface was exposed. When the superficial petrosal greater nerve, facial nerve and arcuate eminence were localised, the cochlear was open in the basal turn and electrode were inserted. The patient achieves good results in the postoperative speech rehabilitation. It confirmed Colletti tesis that deeper electrode insertion in the cochlear implantation through the middle fossa approach enable use of low and middle frequencies, which are very important in speech understanding.

Piezosurgery for the repair of middle cranial fossa meningoencephaloceles.

PubMed

Acharya, Aanand N; Rajan, Gunesh P

2015-03-01

To describe the use of a piezosurgery medical device to perform a craniotomy and produce a split calvarial graft for the repair of middle cranial fossa meningoencephaloceles. Retrospective case review. Tertiary referral hospital. Ten consecutive patients undergoing middle cranial fossa approach for the repair of meningoencephaloceles. Therapeutic. Intraoperative and postoperative complications, success rate as defined by the ability to fashion a split calvarial graft that achieves complete closure of the tegmen defect. As a secondary outcome measure, evidence of integration of the split calvarial bone graft with the adjacent skull base was assessed. There were no intraoperative or postoperative complications. An appropriately sized calvarial bone graft was produced, and complete closure of the tegmen defect was achieved in all 10 cases. Computed tomography demonstrated evidence of integration of the bone graft in eight cases between 4 and 9 months after surgery. The piezosurgery medical device provides a safe and effective means by which the middle fossa craniotomy and split calvarial bone graft can be produced to repair defects of the middle fossa tegmen, with integration of the bone graft in the majority of cases.

Decreased sudomotor function is involved in the formation of atopic eczema in the cubital fossa.

PubMed

Takahashi, Aya; Murota, Hiroyuki; Matsui, Saki; Kijima, Akiko; Kitaba, Shun; Lee, Jeong-Beom; Katayama, Ichiro

2013-12-01

Eczema in the cubital fossa, which is susceptible to sweat, is frequently observed in atopic dermatitis (AD). However, there has been no direct evidence that sweating causes eczema in the cubital fossa. To investigate this issue, axon reflex-mediated sweating volume (AXR) and skin barrier function in the cubital fossa were measured in subjects with AD and in healthy volunteers, and were applied to clinical feature of the cubital fossa. AXR in the cubital fossa decreased in AD subjects; it positively correlated only with water-holding capacity in healthy subjects but not in patients with in AD. Furthermore, AD subjects with lichenoid eczema and either prurigo or papules over the cubital fossa showed extremely decreased AXR. These results suggest that decreased sweating is a major source of water in the stratum corneum, and decreased sudomotor function may be involved in both the cause and aggravation of representative atopic eczema in the cubital fossa.

Nili Fossae Resource and Science ROIs

NASA Astrophysics Data System (ADS)

Markle, L. M.

2015-10-01

The Nili Fossae region presents multiple resource and science ROIs for establishing a permanent colony on Mars. Water ice appears to cover a large are and multiple geological formations provide opportunity for science missions.

Medusae Fossae #1

NASA Image and Video Library

1998-03-13

Extensive wind-swept plains of the Medusae Fossae formation on Mars. This northern subframe image, frame 3104, is of a 3.0 x 4.7 km area centered near 2.4 degrees north, 163.8 degrees west. Science Magazine, Volume 279, Number 5357, 13 March 1998, M. C. Malin, et. al., "Early Views of the Martian Surface from the Mars Orbiter Camera of Mars Global Surveyor", pp. 1681-1685 (Fig. 1A) http://photojournal.jpl.nasa.gov/catalog/PIA00800

An anatomical study of the intersigmoid fossa and applications for internal hernia surgery.

PubMed

Somé, O R; Ndoye, J M; Yohann, R; Nolan, G; Roccia, H; Dakoure, W P; Chaffanjon, P

2017-03-01

To improve the knowledge of the morphometry and the surrounding anatomical structures of the intersigmoid fossa and to determine possible surgical applications. Forty eight adult cadavers (29 female and 19 male; mean age 83 years) underwent dissection in the Laboratoire d'Anatomie des Alpes Francaises. Two injections in the right carotid resulted in a total body concentration of formalin of 1.3 %. The study parameters were the dimensions of the intersigmoid fossa orifice and the fossa's relationship to surrounding structures. Data were recorded and analyzed using Microsoft Office Excel (MS Cerp). A Pearson coefficient r was used to examine the correlation between the length of colon and the ISF volume. The intersigmoid fossa was present in 75 % of cases (n = 36). The average dimensions for the transverse diameter, longitudinal diameter, and the depth were, respectively, 20.5 ± 0.2, 20.3 ± 0.13, and 26.8 ± 0.2 mm. The primary and secondary roots bordering this fossa measured on average 59.1 ± 0.1 and 48.3 ± 0.13 mm. In 13.9 % of cases (n = 5), the maximum depth was >40 mm and in 16.7 % of cases (n = 6), one of the diameters of the orifice entry of the fossa was >40 mm. The ureter and external iliac artery were the most frequently encountered structures during the dissection of the fundus of the intersigmoid fossa. The intersigmoid fossa remains present in most of the reported dissections of cadavers. It constitutes an essential landmark in the surgery of the sigmoid colon due to its deep structural relationship with the left ureter and external iliac artery.

MR imaging evaluation of inferior olivary nuclei: comparison of postoperative subjects with and without posterior fossa syndrome.

PubMed

Patay, Z; Enterkin, J; Harreld, J H; Yuan, Y; Löbel, U; Rumboldt, Z; Khan, R; Boop, F

2014-04-01

Posterior fossa syndrome is a severe postoperative complication occurring in up to 29% of children undergoing posterior fossa tumor resection; it is most likely caused by bilateral damage to the proximal efferent cerebellar pathways, whose fibers contribute to the Guillain-Mollaret triangle. When the triangle is disrupted, hypertrophic olivary degeneration develops. We hypothesized that MR imaging patterns of inferior olivary nucleus changes reflect patterns of damage to the proximal efferent cerebellar pathways and show association with clinical findings, in particular the presence or absence of posterior fossa syndrome. We performed blinded, randomized longitudinal MR imaging analyses of the inferior olivary nuclei of 12 children with and 12 without posterior fossa syndrome after surgery for midline intraventricular tumor in the posterior fossa. The Fisher exact test was performed to investigate the association between posterior fossa syndrome and hypertrophic olivary degeneration on MR imaging. The sensitivity and specificity of MR imaging findings of bilateral hypertrophic olivary degeneration for posterior fossa syndrome were measured. Of the 12 patients with posterior fossa syndrome, 9 had bilateral inferior olivary nucleus abnormalities. The 12 patients without posterior fossa syndrome had either unilateral or no inferior olivary nucleus abnormalities. The association of posterior fossa syndrome and hypertrophic olivary degeneration was statistically significant (P < .0001). Hypertrophic olivary degeneration may be a surrogate imaging indicator for damage to the contralateral proximal efferent cerebellar pathway. In the appropriate clinical setting, bilateral hypertrophic olivary degeneration may be a sensitive and specific indicator of posterior fossa syndrome.

Medusae Fossae Formation

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 16 April 2002) The Science This THEMIS visible image was acquired near 11o N, 159o W (201o E) and shows examples of the remarkable variations that can be seen in the erosion of the Medusae Fossae Formation. This Formation is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region, like many others throughout the Medusae Fossae Formation, the surface has been eroded by the wind into a series of linear ridges called yardangs. These ridges generally point in direction of the prevailing winds that carved them, and demonstrate the power of martian winds to erode the landscape of Mars. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Within this single image it is possible to see differing amounts of erosion and stripping of layers in the Medusae Fossae Formation. Near the bottom (southern) edge of the image a rock layer with a relatively smooth upper surface covers much of the image. Moving upwards (north) in the image this layer becomes more and more eroded. At first there are isolated regions where the smooth unit has been eroded to produce sets of parallel ridges and knobs. Further north these linear knobs increase in number, and only small, isolated patches of the smooth upper surface remain. Finally, at the top of the image, even the ridges have been removed, exposing the remarkably smooth top of hard, resistant layer below. This sequence of layers with differing hardness and resistance to erosion is common on Earth and on Mars, and suggests significant variations in the physical properties, composition, particle size, and/or cementation of these martian layers. As is common throughout the Medusae Fossae Formation, very few impact craters are visible, indicating that the surface exposed is relatively young, and that the process of erosion may be active today

Medusae Fossae Formation

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 10 April 2002) The Science This THEMIS visible image was acquired near 7o S, 172o W (188o E) and shows a remarkable martian geologic deposit known as the Medusae Fossae Formation. This Formation, seen here as the raised plateau in the upper two-thirds of the image, is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region the deposit has been heavily eroded by the wind to produce a series of linear ridges called yardangs. These parallel ridges point in direction of the prevailing winds that carved them, and demonstrate the power of martian winds to sculpt the dry landscape of Mars. The Medusae Fossae Formation has been completely stripped from the surface in the lower third of the image, revealing a harder layer below that is more resistant to wind erosion. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Several ancient craters that were once completely buried by this deposit are being exposed, or exhumed, as the overlying Medusae Formation is removed. Very few impact craters are visible on this Formation, indicating that the surface seen today is relatively young, and that the processes of erosion are likely to be actively occurring. The Story Medusa of Greek mythology fame, the name-giver to this region, had snaky locks of hair that could turn a person to stone. Wild and unruly, this monster of the underworld could certainly wreak havoc on the world of the human imagination. As scary as she was, Medusa would have no advantage over the fierce, masterful winds blowing across Mars, which once carved the streaky, terrain at the top of this image. Wild and whipping, these winds have slowly eroded away the 'topsoil,' revealing ancient craters and other surface features they once covered. The loosely cemented particles of this 'topsoil' are likely made up of dust

Endoscopic endonasal approach for mass resection of the pterygopalatine fossa

PubMed Central

Plzák, Jan; Kratochvil, Vít; Kešner, Adam; Šurda, Pavol; Vlasák, Aleš; Zvěřina, Eduard

2017-01-01

OBJECTIVES: Access to the pterygopalatine fossa is very difficult due to its complex anatomy. Therefore, an open approach is traditionally used, but morbidity is unavoidable. To overcome this problem, an endoscopic endonasal approach was developed as a minimally invasive procedure. The surgical aim of the present study was to evaluate the utility of the endoscopic endonasal approach for the management of both benign and malignant tumors of the pterygopalatine fossa. METHOD: We report our experience with the endoscopic endonasal approach for the management of both benign and malignant tumors and summarize recent recommendations. A total of 13 patients underwent surgery via the endoscopic endonasal approach for pterygopalatine fossa masses from 2014 to 2016. This case group consisted of 12 benign tumors (10 juvenile nasopharyngeal angiofibromas and two schwannomas) and one malignant tumor. RESULTS: No recurrent tumor developed during the follow-up period. One residual tumor (juvenile nasopharyngeal angiofibroma) that remained in the cavernous sinus was stable. There were no significant complications. Typical sequelae included hypesthesia of the maxillary nerve, trismus, and dry eye syndrome. CONCLUSION: The low frequency of complications together with the high efficacy of resection support the use of the endoscopic endonasal approach as a feasible, safe, and beneficial technique for the management of masses in the pterygopalatine fossa. PMID:29069259

Demographic confounders in volumetric MRI analysis: is the posterior fossa really small in the adult Chiari 1 malformation?

PubMed

Roller, Lauren A; Bruce, Beau B; Saindane, Amit M

2015-04-01

Measurement of posterior fossa volume has been proposed to have diagnostic utility and physiologic significance in the Chiari malformation type 1. This study evaluated the effects of demographics on posterior fossa volume and total intracranial volume in adult control subjects, adult patients with Chiari malformation type 1, and adult patients with idiopathic intracranial hypertension, who may share some imaging features of patients with Chiari malformation type 1. Twenty-eight patients with Chiari malformation type 1, 21 patients with idiopathic intracranial hypertension, and 113 control subjects underwent brain MRI including contrast-enhanced 3D gradient-recalled echo (GRE) T1-weighted imaging. Linear measurements of the posterior fossa and intracranial space were obtained. Manual segmentation of the posterior fossa and intracranial space was performed to yield posterior fossa volume and total intracranial volume. Age, sex, race, and body mass index (weight in kilograms divided by the square of height in meters; BMI) were controlled for when comparing cohorts. Three of the 12 linear measurements significantly predicted total intracranial volume (accounting for 74% of variance), and four predicted posterior fossa volume (54% of variance). Age, race, sex, and BMI each statistically significantly influenced posterior fossa volume and total intracranial volume. No statistically significant differences in posterior fossa volume, total intracranial volume, or ratio of posterior fossa volume to total intracranial volume were seen between the Chiari malformation type 1 group and control group after controlling for demographics. Patients with idiopathic intracranial hypertension were more likely than control subjects to have smaller posterior fossa volumes (odds ratio [OR]=1.81; p=0.01) and larger total intracranial volumes (OR=1.24; p=0.06). Linear measurements of the posterior fossa are not strong predictors of posterior fossa volume. Age, race, sex, and BMI have

3D printing the pterygopalatine fossa: a negative space model of a complex structure.

PubMed

Bannon, Ross; Parihar, Shivani; Skarparis, Yiannis; Varsou, Ourania; Cezayirli, Enis

2018-02-01

The pterygopalatine fossa is one of the most complex anatomical regions to understand. It is poorly visualized in cadaveric dissection and most textbooks rely on schematic depictions. We describe our approach to creating a low-cost, 3D model of the pterygopalatine fossa, including its associated canals and foramina, using an affordable "desktop" 3D printer. We used open source software to create a volume render of the pterygopalatine fossa from axial slices of a head computerised tomography scan. These data were then exported to a 3D printer to produce an anatomically accurate model. The resulting 'negative space' model of the pterygopalatine fossa provides a useful and innovative aid for understanding the complex anatomical relationships of the pterygopalatine fossa. This model was designed primarily for medical students; however, it will also be of interest to postgraduates in ENT, ophthalmology, neurosurgery, and radiology. The technical process described may be replicated by other departments wishing to develop their own anatomical models whilst incurring minimal costs.

Cerebellar medulloblastoma: the importance of posterior fossa dose to survival and patterns of failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silverman, C.L.; Simpson, J.R.

1982-11-01

Fifty patients with biopsy-proven cerebellar medulloblastoma were retrospectively analyzed for prognostic factors, survival and patterns of failure. Five- and ten-year actuarial survivals for the entire group were 51% and 42%. Survival and local control were significantly better for the 21 patients who received doses greater than 5000 rad to the posterior fossa (85% and 80% respectively) than for the remaining patients (38% and 38%, respectively). Significant prognostic factors included achievement of local control in the posterior fossa (p = .0001) and dose to the posterior fossa (p = .0005). Sex, age, duration of symptoms, extent of surgery and initial T-stagemore » of disease were not significant. Posterior fossa was the predominant site of failure (71% of failures), but 10% of patients failed in the cerebrum and 12% outside the CNS. This experience confirms that survival rates of 70-80% are achievable with current treatment policies but accurate and consistent dose delivery to the posterior fossa is essential.« less

Cerebellar medulloblastoma: the importance of posterior fossa dose to survival and patterns of failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silverman, C.L.; Simpson, J.R.

1982-11-01

Fifty patients with biopsy-proven cerebellar medulloblastoma were retrospectively analyzed for prognostic factors, survival and patterns of failure. Five- and ten-year actuarial survivals for the entire group were 51% and 42%. Survival and local control were significantly better for the 21 patients who received doses greater that 5000 rad to the posterior fossa (85% and 80% respectively) than for the remaining patients (38% and 38%, respectively). Significant prognostic factors included achievement of local control in the posterior fossa (p = .0001) and dose to the posterior fossa (p = .0005). Sex, age, duration of symptoms, extent of surgery and initial T-stagemore » of disease were not significant. Posterior fossa was the predominant site of failure (71% of failures), but 10% of patients failed in the cerebrum and 12% outside the CNS. This experience confirms that survival rates of 70-80% are achievable with current treatment policies but accurate and consistent dose delivery to the posterior fossa is essential.« less

Nili Fossae Trough, Candidate MSL Landing Site

NASA Image and Video Library

2010-12-20

This image from NASA Mars Reconnaissance Orbiter shows Nili Fossae region of Mars, one of the largest exposures of clay minerals, and a prime candidate landing site for Mars Science Laboratory rover, Curiosity.

[Acute epidural hematoma of the posterior fossa caused by forehead impact].

PubMed

Abe, S; Furukawa, K; Endo, S; Hoshi, S; Kanaya, H

1988-03-01

A rare case of acute epidural hematoma of the posterior fossa caused by forehead impact is reported. This 36-year-old man fell from a truck and hit his face. He was conscious and was brought to our center 30 minutes after the injury. On admission, a contused wound of the right forehead was noticed. He was restless and had severe pain in the neck and upper extremities. Skull X-ray showed a linear fracture of the frontal bone and computed tomography (CT) scan was normal. He continued to be restless and sudden respiratory arrest and pupillary dilation occurred 10 hours after the admission. A CT scan revealed a lenticular high density area in the left posterior fossa which extended to the supratentorial region. The 4th ventricle was compressed and displaced to the right and also the quadrigeminal and ambient cisterns were not visualized at all. Immediate surgery disclosed a 30 g epidural hematoma of the left posterior fossa and the supratentorium and the clot was completely evacuated. The source of bleeding could not be identified. Opening of the dura revealed contusion in the occipital lobe. He died on the 17th postoperative day. The possible mechanism in the production of the posterior fossa hematoma in this case is discussed.

Posttraumatic epidermal inclusion cyst of the deep infratemporal fossa.

PubMed

Acarturk, T O; Stofman, G M

2001-01-01

The authors report a case of an epidermal inclusion cyst found in the deep infratemporal fossa 12 years after the patient sustained blunt trauma to that region. Posttraumatic epidermal inclusion cysts are rare and occur mainly in the fingers, palms, and soles. Introduction of the epidermal elements into the dermis during the trauma is thought to be the cause. This case is rare in presentation, with few reports in the English literature that describe an epidermal inclusion cyst in the deep infratemporal fossa. Review of the English literature disclosed no other cases of epidermal inclusion cyst after blunt trauma involving the deep infratemporal region.

Endoscopic Third Ventriculostomy before Posterior Fossa Tumor Surgery in Adult Patients.

PubMed

Marx, Sascha; El Damaty, Ahmed; Manwaring, Jotham; El Refaee, Ehab; Fleck, Steffen; Fritsch, Michael; Gaab, Michael R; Schroeder, H W S; Baldauf, Jörg

2018-03-01

 Obstructive hydrocephalus in patients with posterior fossa tumors is frequently seen. Treatment options include immediate tumor removal or prior cerebrospinal fluid (CSF) diversion procedures. The necessity and feasibility of an ETV in these situations has not yet been proven in adult patients.  We retrospectively reviewed our prospectively maintained database for ETVs before surgery of posterior fossa tumors in adults. The primary focus of data analyses was the question of whether the ETV was suitable to treat the acute situation of hydrocephalus without an increased rate of complications due to the special anatomical situation with a posterior fossa tumor. We also analyzed whether any further CSF diverting procedures were necessary.  A total of 40 adult patients who underwent an ETV before posterior fossa tumor surgery were analyzed. Overall, 33 patients (82.5%) had clinical signs of hydrocephalus, and all of them improved in their clinical course after ETV. Seven patients (17.5%) did not demonstrate clinical signs of hydrocephalus, but ETV was performed with prophylactic or palliative intent in six patients and one patient, respectively. No complications were observed due to ETV itself. No permanent shunting procedure was necessary in a mean follow-up of 76.5 months. Early additional CSF diverting procedures (redo ETV, external ventricular drain) were performed in five patients (12.5%).  The present series confirms the feasibility and safety of ETV before posterior fossa tumor surgery in adult patients. If patients had symptomatic hydrocephalus before tumor surgery, an ETV can be performed, followed by early elective tumor surgery. A prophylactic ETV in asymptomatic patients is not advised. Early elective tumor surgery should be performed in these patients. Georg Thieme Verlag KG Stuttgart · New York.

Extra-skeletal Ewing's sarcoma of the nasal fossa.

PubMed

Lane, S; Ironside, J W

1990-07-01

Extraskeletal Ewing's sarcoma is rarely found arising in the head and neck region. An unusual case arising in the nasal fossa in a young child is reported and the differential diagnosis, pathology and treatment discussed.

Rippled Surfaces on a Slope in Coloe Fossae

NASA Image and Video Library

2014-01-09

This observation from NASA Mars Reconnaissance Orbiter shows a set of landforms that appears to form a nested chevron pattern on a slope in Coloe Fossae. Interestingly, nearby surfaces on the same slope are all parallel.

Endoscopic Removal of a Bullet in Rosenmuller Fossa: Case Report

PubMed Central

Burks, Joshua D.; Glenn, Chad A.; Conner, Andrew K.; Bonney, Phillip A.; Sanclement, Jose A.; Sughrue, Michael E.

2016-01-01

Fractures of the anterior skull base may occur in gunshot victims and can result in traumatic cerebrospinal fluid (CSF) leak. Less commonly, CSF leaks occur days or even weeks after the trauma occurred. Here, we present the case of a 21-year-old man with a delayed-onset, traumatic CSF leak secondary to a missile injury that left a bullet fragment in the Rosenmuller fossa. The patient was treated successfully with endoscopic, endonasal extraction of the bullet, and repair with a nasal septal flap. Foreign bodies lodged in Rosenmuller fossa can be successfully treated with endoscopic skull base surgery. PMID:27330924

Metrics and textural features of MRI diffusion to improve classification of pediatric posterior fossa tumors.

PubMed

Rodriguez Gutierrez, D; Awwad, A; Meijer, L; Manita, M; Jaspan, T; Dineen, R A; Grundy, R G; Auer, D P

2014-05-01

Qualitative radiologic MR imaging review affords limited differentiation among types of pediatric posterior fossa brain tumors and cannot detect histologic or molecular subtypes, which could help to stratify treatment. This study aimed to improve current posterior fossa discrimination of histologic tumor type by using support vector machine classifiers on quantitative MR imaging features. This retrospective study included preoperative MRI in 40 children with posterior fossa tumors (17 medulloblastomas, 16 pilocytic astrocytomas, and 7 ependymomas). Shape, histogram, and textural features were computed from contrast-enhanced T2WI and T1WI and diffusivity (ADC) maps. Combinations of features were used to train tumor-type-specific classifiers for medulloblastoma, pilocytic astrocytoma, and ependymoma types in separation and as a joint posterior fossa classifier. A tumor-subtype classifier was also produced for classic medulloblastoma. The performance of different classifiers was assessed and compared by using randomly selected subsets of training and test data. ADC histogram features (25th and 75th percentiles and skewness) yielded the best classification of tumor type (on average >95.8% of medulloblastomas, >96.9% of pilocytic astrocytomas, and >94.3% of ependymomas by using 8 training samples). The resulting joint posterior fossa classifier correctly assigned >91.4% of the posterior fossa tumors. For subtype classification, 89.4% of classic medulloblastomas were correctly classified on the basis of ADC texture features extracted from the Gray-Level Co-Occurence Matrix. Support vector machine-based classifiers using ADC histogram features yielded very good discrimination among pediatric posterior fossa tumor types, and ADC textural features show promise for further subtype discrimination. These findings suggest an added diagnostic value of quantitative feature analysis of diffusion MR imaging in pediatric neuro-oncology. © 2014 by American Journal of Neuroradiology.

Geology of the Bellona Fossae (V15) Region of Venus

NASA Astrophysics Data System (ADS)

Zimbelman, J. R.

2002-05-01

A preliminary geologic map of the the Bellona Fossae (V15) quadrangle on Venus was produced as part of the NASA-funded planetary mapping program. Geologic interpretations are based primarily on the basis of morphology, texture, radar reflectance, and relative stratigraphy derived from Magellan Synthetic Aperture Radar (SAR) images, based on FMAP mosaics showing SAR data at 75 m/pixel resolution, and compiled on a digital base map at 1:5M scale produced by the U.S. Geological Survey. This quadrangle covers approximately 5 million square kilometers of the northern lowlands of Venus, and it includes the Bellona Fossae and Fee Fossae fracture systems of western Kawelu Planitia and northern Ulfrun Regio, along with an arcuate chain of volcano-tectonic centers called coronae (e.g., Ki and Tituba Coronae). Exposed materials are dominated by relatively featureless regional plains and several centers of lobate plains (e.g., Uzume Fluctus) interpreted to be lava flow fields emplaced by effusion from separate vents. Based on stratigraphic relationships at unit contacts, the oldest exposed material units are isolated patches of complex-faulted tessera terrain, restricted to the eastern and southwestern margins of the quadrangle. Relatively small exposures of lineated plains, mountain belt, ridged plains, and dark plains materials are scattered throughout the quadrangle, with only a few impact craters and their associated ejecta and impact-induced flows (e.g., Mumtaz-Mahal crater) representing the latest materials. The tectonism associated with the coronae appears to predate the regional plains for the most part, but individual coronae are the source for lobate plains volcanism which implies that activity at these structural features encompasses much of the time span portrayed in the regional stratigraphy. Northeast-southwest-oriented lineaments exposed in Bellona Fossae not only are generally coincident with the coronae structures, but also cut patches of the stratigraphically

Diagnostic imaging of posterior fossa anomalies in the fetus.

PubMed

Robinson, Ashley James; Ederies, M Ashraf

2016-10-01

Ultrasound and magnetic resonance imaging are the two imaging modalities used in the assessment of the fetus. Ultrasound is the primary imaging modality, whereas magnetic resonance is used in cases of diagnostic uncertainty. Both techniques have advantages and disadvantages and therefore they are complementary. Standard axial ultrasound views of the posterior fossa are used for routine scanning for fetal anomalies, with additional orthogonal views directly and indirectly obtainable using three-dimensional ultrasound techniques. Magnetic resonance imaging allows not only direct orthogonal imaging planes, but also tissue characterization, for example to search for blood breakdown products. We review the nomenclature of several posterior fossa anomalies using standardized criteria, and we review cerebellar abnormalities based on an etiologic classification. Copyright © 2016 Elsevier Ltd. All rights reserved.

Increased depth-diameter ratios in the Medusae Fossae Formation deposits of Mars

NASA Technical Reports Server (NTRS)

Barlow, N. G.

1993-01-01

Depth to diameter ratios for fresh impact craters on Mars are commonly cited as approximately 0.2 for simple craters and 0.1 for complex craters. Recent computation of depth-diameter ratios in the Amazonis-Memnonia region of Mars indicates that craters within the Medusae Fossae Formation deposits found in this region display greater depth-diameter ratios than expected for both simple and complex craters. Photoclinometric and shadow length techniques have been used to obtain depths of craters within the Amazonis-Memnonia region. The 37 craters in the 2 to 29 km diameter range and displaying fresh impact morphologies were identified in the area of study. This region includes the Amazonian aged upper and middle members of the Medusae Fossae Formation and Noachian aged cratered and hilly units. The Medusae Fossae Formation is characterized by extensive, flat to gently undulating deposits of controversial origin. These deposits appear to vary from friable to indurated. Early analysis of crater degradation in the Medusae Fossae region suggested that simple craters excavated to greater depths than expected based on the general depth-diameter relationships derived for Mars. However, too few craters were available in the initial analysis to estimate the actual depth-diameter ratios within this region. Although the analysis is continuing, we are now beginning to see a convergence towards specific values for the depth-diameter ratio depending on geologic unit.

Sirenum Fossae Trough

NASA Technical Reports Server (NTRS)

2000-01-01

[figure removed for brevity, see original site]

The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) orbits the red planet twelve times each day. The number of pictures that MOC can take varies from orbit to orbit, depending upon whether the data are being stored in MGS's onboard tape recorder for playback at a later time, or whether the data are being sent directly back to Earth via a real-time radio link. More data can be acquired during orbits with real-time downlink.

During real-time orbits, the MOC team often will take a few random or semi-random pictures in between the carefully-selected, hand-targeted images. On rare occasions, one of these random pictures will surprise the MOC team. The picture shown here is an excellent example, because the high resolution view (top) is centered so nicely on a trough and an adjacent, shallow crater that it is as if someone very carefully selected the target for MOC. The high-resolution view covers an area only 1.1 km (0.7 mi) wide by 2.3 km (1.4 mi) long. Hitting a target such as this with such a small image is very difficult to do, on purpose, because there are small uncertainties in the predicted orbit, the maps used to select targets, and the minor adjustments of spacecraft pointing at any given moment. Nevertheless, a very impressive image was received.

The high resolution view crosses one of the troughs of the Sirenum Fossae near 31.2oS, 152.3oW. The context image (above) was acquired at the same time as the high resolution view on July 23, 2000. The small white box shows the location of the high resolution picture. The lines running diagonally across the context image from upper right toward lower left are the Sirenum Fossae troughs, formed by faults that are radial to the volcanic region of Tharsis. Both pictures are illuminated from the upper left. The scene shows part of the martian southern hemisphere nearly autumn.

Knife wound to the posterior fossa in a child.

PubMed

Mohan, Avinash L; Slim, Michel; Benzil, Deborah L

2005-03-01

Knife wounds to the posterior fossa are a rare occurrence, especially in children. We report an 8-year-old girl who sustained a penetrating knife injury through the occipital bone into the posterior fossa. On presentation, the large knife blade was firmly embedded in her head. Radiographic evaluation was limited to plain X-rays because of the large size and sharpness of the embedded blade. Innovative positioning was used during intubation and then the patient was positioned semi-prone on the operating room table. The blade was surgically removed and the dura was closed. Atypical penetrating cranial injuries in children may require the treatment team to take a creative approach to the evaluation and repair of the lesion in order to maximize patient safety and minimize the risk of neurological injury.

Lacrimal fossa lesions: a review of 146 cases in Egypt

PubMed Central

Eldesouky, Mohammed A; Elbakary, Molham A; Sabik, Saly; Shareef, Mohamed M

2014-01-01

Purpose The incidence and clinical and imaging criteria of different pathological forms of lacrimal fossa lesions in the Delta region of Egypt were studied. Methods A retrospective study of patients with lacrimal fossa lesions for the past 10 years was conducted. A total of 146 cases were identified. Their medical records were reviewed for clinical and imaging data (computed tomography scan, magnetic resonance imaging scan, or both). A definitive diagnosis based on pathological examination of biopsies was also reviewed. Results Among the patients reviewed, 43.15% had inflammatory lacrimal gland lesions, 26.71% had lymphoproliferative lesions, and 21.92% had epithelial lesions; 8.22% had rare lesions (5.48% were dacryops and 2.74% had hemangioma). The study included 71.92% benign lesions and 28.08% malignant lesions, which were distributed between 19.18% malignant lymphoma and 8.9% malignant epithelial tumors. According to the pathological origin of the lesions, they may be classified into 78.08% nonepithelial lesions and 21.92% epithelial lesions (16.44% epithelial tumors, and 5.48% dermoid cysts). Conclusion Lacrimal fossa lesions show a wide pathological range. Inflammatory lesions are most frequent, followed by lymphoproliferative and epithelial lesions. Analysis of clinical and radiological criteria is helpful in the differential diagnosis of lacrimal gland lesions. PMID:25210428

Gamma Knife radiosurgery for posterior fossa meningiomas: a multicenter study.

PubMed

Sheehan, Jason P; Starke, Robert M; Kano, Hideyuki; Barnett, Gene H; Mathieu, David; Chiang, Veronica; Yu, James B; Hess, Judith; McBride, Heyoung L; Honea, Norissa; Nakaji, Peter; Lee, John Y K; Rahmathulla, Gazanfar; Evanoff, Wendi A; Alonso-Basanta, Michelle; Lunsford, L Dade

2015-06-01

Posterior fossa meningiomas represent a common yet challenging clinical entity. They are often associated with neurovascular structures and adjacent to the brainstem. Resection can be undertaken for posterior fossa meningiomas, but residual or recurrent tumor is frequent. Stereotactic radiosurgery (SRS) has been used to treat meningiomas, and this study evaluates the outcome of this approach for those located in the posterior fossa. At 7 medical centers participating in the North American Gamma Knife Consortium, 675 patients undergoing SRS for a posterior fossa meningioma were identified, and clinical and radiological data were obtained for these cases. Females outnumbered males at a ratio of 3.8 to 1, and the median patient age was 57.6 years (range 12-89 years). Prior resection was performed in 43.3% of the patient sample. The mean tumor volume was 6.5 cm(3), and a median margin dose of 13.6 Gy (range 8-40 Gy) was delivered to the tumor. At a mean follow-up of 60.1 months, tumor control was achieved in 91.2% of cases. Actuarial tumor control was 95%, 92%, and 81% at 3, 5, and 10 years after radiosurgery. Factors predictive of tumor progression included age greater than 65 years (hazard ratio [HR] 2.36, 95% CI 1.30-4.29, p = 0.005), prior history of radiotherapy (HR 5.19, 95% CI 1.69-15.94, p = 0.004), and increasing tumor volume (HR 1.05, 95% CI 1.01-1.08, p = 0.005). Clinical stability or improvement was achieved in 92.3% of patients. Increasing tumor volume (odds ratio [OR] 1.06, 95% CI 1.01-1.10, p = 0.009) and clival, petrous, or cerebellopontine angle location as compared with petroclival, tentorial, and foramen magnum location (OR 1.95, 95% CI 1.05-3.65, p = 0.036) were predictive of neurological decline after radiosurgery. After radiosurgery, ventriculoperitoneal shunt placement, resection, and radiation therapy were performed in 1.6%, 3.6%, and 1.5%, respectively. Stereotactic radiosurgery affords a high rate of tumor control and neurological preservation

Congenital cholesteatoma of the infratemporal fossa with congenital aural atresia and mastoiditis: a case report.

PubMed

Abdel-Aziz, Mosaad

2012-06-25

Congenital cholesteatoma may be expected in abnormally developed ear, it may cause bony erosion of the middle ear cleft and extend to the infratemporal fossa. We present the first case of congenital cholesteatoma of the infratemporal fossa in a patient with congenital aural atresia that has been complicated with acute mastoiditis. A sixteen year old Egyptian male patient presented with congenital cholesteatoma of the infratemporal fossa with congenital aural atresia complicated with acute mastoiditis. Two weeks earlier, the patient suffered pain necessitating hospital admission, magnetic resonance imaging revealed a soft tissue mass in the right infratemporal fossa. On presentation to our institute, Computerized tomography was done as a routine, it proved the diagnosis of mastoiditis, pure tone audiometry showed an air-bone gap of 60 dB. Cortical mastoidectomy was done for treatment of mastoiditis, removal of congenital cholesteatoma was carried out with reconstruction of external auditory canal. Follow-up of the patient for 2 years and 3 months showed a patent, infection free external auditory canal with an air-bone gap has been reduced to 35db. One year after the operation; MRI was done and it showed no residual or recurrent cholesteatoma. Congenital cholesteatoma of the infratemporal fossa in cases of congenital aural atresia can be managed safely even if it was associated with mastoiditis. It is an original case report of interest to the speciality of otolaryngology.

Dislocation of the mandibular condyle into the middle cranial fossa causing an epidural haematoma.

PubMed

Struewer, Johannes; Kiriazidis, Ilias; Figiel, Jens; Dukatz, Thomas; Frangen, Thomas; Ziring, Ewgeni

2012-07-01

Dislocation of the mandibular condyle into the middle cranial fossa is a rare complication of mandibular trauma due to anatomical and biomechanical factors. Owing to the proximity of the temporal glenoid fossa to the middle meningeal artery, there is the risk of serious sequelae in case of trauma. The authors report the case of a 36-year-old male patient, who was beaten up in a family dispute and presented with complex mandibular and maxillofacial fractures, including mandibular condyle intrusion into the middle cranial fossa causing extensive meningeal bleeding. The patient underwent immediate surgery, with evacuation of the epidural haematoma via a temporal approach. In addition open reduction and reconstruction of the temporal glenoid fossa via anatomic reduction of the fragments was performed. A functional occlusion was re-established via miniplate reconstruction of the complex mandibular body and ramus fractures. Prompt diagnosis and a multidisciplinary approach are essential to minimize the complications. Advanced imaging modalities of computed tomography are indicated. Treatment options should be individualized in particular in case of suspected neurological injury. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Decrypting the Formation Conditions of the Basement Carbonate-Bearing Rocks at Nili Fossae

NASA Astrophysics Data System (ADS)

Brown, A. J.

2015-12-01

The Nili Fossae region is the site of a number of proposed Landing Sites for the Mars 2020 Rover. A distinguishing feature of many of these sites is the access to large exposures of carbonate (Ehlmann et al. 2008). Serpentinization has been proposed as a formation mechanism of these carbonates, including carbonated (Brown et al. 2010, Viviano, et al. 2013) and low temperature, near surface serpentinization. The potential for carbonated serpentization at Nili Fossae links the region to Earth analogs in terrestrial greenstone belts such as the Pilbara in Western Australia, where talc-carbonate bearing komatiite cumulate units of the Dresser Formation overlie the siliceous, stromatolite-bearing Strelley Pool Chert unit (Van Kranendonk and Pirajno, 2004). If a similar relationship exists on Mars, investigations of rocks stratigraphically beneath the carbonate-bearing units at Nili Fossae ("the basement rocks") may provide the best chance to examine well preserved organic material from the Noachian. This hypothesis is testable by Mars 2020. In preparation for the the Mars 2020 landing site, we are examining the thermodynamic relationships that favor formation of serpentine and talc-carbonate and different pressures and temperatures in the crust (Barnes 2007). This will allow us to constrain the low grade metamorphism required to replicate the proposed models of serpentinisation and help us understand the regional metamophic gradient that is critical to furthering our knowledge of the ancient rocks of Nili Fossae. Refs:Barnes, S. J. "Komatiites: Petrology, Volcanology, Metamorphism, and Geochemistry." S.E.G. 13 (2007): 13. Brown, A. J., et al.. "Hydrothermal Formation of Clay-Carbonate Alteration Assemblages in the Nili Fossae Region of Mars." EPSL 297 (2010): 174-82. Ehlmann, B. L. et al. "Orbital Identification of Carbonate-Bearing Rocks on Mars." Science 322, no. 5909 1828-32. Van Kranendonk, M.J., and F. Pirajno. "Geochemistry of Metabasalts and Hydrothermal

Arachnoid Cyst in the Middle Cranial Fossa Presenting with Pulsatile Exophthalmos: Case Report and Literature Review

PubMed Central

SAITO, Atsushi; KON, Hiroyuki; HARYU, Shinya; MINO, Masaki; SASAKI, Tatsuya; NISHIJIMA, Michiharu

2014-01-01

A 20-year-old woman suffered gradual progression of right pulsatile exophthalmos and slight headache. Computed tomography (CT) demonstrated outward and downward displacement of the right globe and an arachnoid cyst in the right middle cranial fossa associated with thinned and anterior protrusion of a bony orbit. Microscopic cystocisternotomy was performed and the cerebrospinal fluid (CSF) inside of the cyst communicated into the carotid cistern and cistern in the posterior cranial fossa. Pulsatile exophthalmos improved immediately after surgery. Arachnoid cyst in the middle cranial fossa presenting with exophthalmos is rare. Microscopic cystocisternotomy might successfully improve CSF flow and relieve exophthalmos. PMID:24305013

Endoscopic surgical treatment of neurogenic tumor in pterygopalatine and infratemporal fossae via extended medial maxillectomy.

PubMed

Xu, Feng; Sun, Xicai; Hu, Li; Wang, Jingjing; Wang, Dehui; Pasic, Thomas R; Kern, Robert C

2011-02-01

The endoscopic extended medial maxillectomy approach for the management of lesions of the pterygopalatine and infratemporal fossa provides excellent exposure and results with good hemostasis and low morbidity. This approach is a viable alternative to the open approaches to these areas. To describe an endoscopic extended medial maxillectomy approach for the treatment of nonmalignant tumors in the pterygopalatine and infratemporal fossa. From January 2004 to June 2007, five patients who had tumors in the pterygopalatine fossa and/or infratemporal fossa, and underwent surgical resection of the tumors with the endoscopic extended medial maxillectomy approach, were reviewed regarding demographics, preoperative images, tumor cell type, surgical techniques, and outcomes. Five patients underwent the procedure mentioned above; three females and two males with a mean age of 38 and a range of 21-58 years. All patients had adequate exposure and total tumor resection with the endoscopic extended medial maxillectomy approach. None of the patients required an external approach for tumor extirpation. There were no major postoperative complications. No evidence of tumor recurrence was noted after follow-up for 12-78 months.

[Morphometric evaluation of the lateral fossa during the pre-gyrus period].

PubMed

Varlam, H; Macovei, G N; Antohe, D St

2002-09-01

During edification of neocortex, the lateral fossa is involved in the process of development of cerebral hemispheres. It changes its shape and, from a shallow depression at the end of the 3rd month, it becomes a triangular surface with marked borders. Finally, in the same time with the appearance of circumvolutions the opercles that limit it come closer and give rise to the lateral sulcus. The evolution of the lateral fossa can be analysed by linear and surface parameters. Morphometric and statistic analyse of these parameters, compared with those of the cerebral hemisphere, allowed us to establish some original criteria for appreciating the growth of the foetal brain.

Two distinct populations of Chiari I malformation based on presence or absence of posterior fossa crowdedness on magnetic resonance imaging.

PubMed

Taylor, Davis G; Mastorakos, Panagiotis; Jane, John A; Oldfield, Edward H

2017-06-01

OBJECTIVE A subset of patients with Chiari I malformation demonstrate patent subarachnoid spaces around the cerebellum, indicating that reduced posterior fossa volume alone does not account for tonsillar descent. The authors distinguish two subsets of Chiari I malformation patients based on the degree of "posterior fossa crowdedness" on MRI. METHODS Two of the coauthors independently reviewed the preoperative MR images of 49 patients with Chiari I malformation and categorized the posterior fossa as "spacious" or "crowded." Volumetric analysis of posterior fossa structures was then performed using open-source DICOM software. The preoperative clinical and imaging features of the two groups were compared. RESULTS The posterior fossae of 25 patients were classified as spacious and 20 as crowded by both readers; 4 were incongruent. The volumes of the posterior fossa compartment, posterior fossa tissue, and hindbrain (posterior fossa tissue including herniated tonsils) were statistically similar between the patients with spacious and crowed subtypes (p = 0.33, p = 0.17, p = 0.20, respectively). However, patients in the spacious and crowded subtypes demonstrated significant differences in the ratios of posterior fossa tissue to compartment volumes as well as hindbrain to compartment volumes (p = 0.001 and p = 0.0004, respectively). The average age at surgery was 29.2 ± 19.3 years (mean ± SD) and 21.9 ± 14.9 years for spacious and crowded subtypes, respectively (p = 0.08). Syringomyelia was more prevalent in the crowded subtype (50% vs 28%, p = 0.11). CONCLUSIONS The authors' study identifies two subtypes of Chiari I malformation, crowded and spacious, that can be distinguished by MRI appearance without volumetric analysis. Earlier age at surgery and presence of syringomyelia are more common in the crowded subtype. The presence of the spacious subtype suggests that crowdedness alone cannot explain the pathogenesis of Chiari I malformation in many patients, supporting

Complete Recovery of Visual Disorder Following Surgical Resection of Adenoid Cystic Carcinoma Arising in the Pterygopalatine Fossa

PubMed Central

Du, Wei; Cui, Meng; Li, Peng; Wang, Jiheng; Luo, Ruihua; Qi, Jinxing; Zhao, Ming; Lou, Weihua

2015-01-01

Abstract Adenoid cystic carcinoma (ACC) arising in the pterygopalatine fossa was rare, only 3 cases have been reported. In previous literature, few authors reported whether the visual deficit could be resolved following the resection of the tumor. One patient with visual dysfunction induced by ACC arising in the pterygopalatine fossa was reported. Complete visual recovery was achieved following the operation. And the patient was satisfied with the appearance and the functional results in the follow-up. Visual loss contributed by the tumor in the pterygopalatine fossa could recover in selected patients. PMID:26039119

Advances in the Study of the Middle Cranial Fossa through Cutting Edge Neuroimaging Techniques.

PubMed

Juanes Méndez, Juan A; Ruisoto, Pablo; Paniagua, Juan C; Prats, Alberto

2018-01-16

The objective of this paper is to present a morphometric study of the middle cranial fossa from the study of 87 patients using cutting edge multislice computed tomography scans (32 detectors) and Magnetic Resonance Imaging. The study presents a detailed anatomical-radiological and morphometric analysis of the middle cranial fossa as well as its neurovascular elements in normal conditions. The implications of this investigation in training and clinical contexts are discussed.

Cerberus Fossae, Elysium, Mars: a source for lava and water

NASA Astrophysics Data System (ADS)

Plescia, J. B.

2003-07-01

Cerberus Fossae, a long fracture system in the southeastern part of Elysium, has acted as a conduit for the release of both lava and water onto the surface. The southeastern portion of the fracture system localized volcanic vents having varying morphology. In addition, low shields occur elsewhere on the Cerberus plains. Three locations where the release of water has occurred have been identified along the northwest (Athabasca and Grjota' Vallis) and southeast (Rahway Vallis) portions of the fossae. Water was released both catastrophically and noncatastrophically from these locations. A fluvial system that extends more than 2500 km has formed beginning at the lower flank of the Elysium rise across the Cerberus plains and out through Marte Vallis into Amazonis Planitia. The timing of the events is Late Amazonian.

Unilateral abducens and bilateral facial nerve palsies associated with posterior fossa exploration surgery

PubMed Central

Khalil, Ayman; Clerkin, James; Mandiwanza, Tafadzwa; Green, Sandra; Javadpour, Mohsen

2016-01-01

Multiple cranial nerves palsies following a posterior fossa exploration confined to an extradural compartment is a rare clinical presentation. This case report describes a young man who developed a unilateral abducens and bilateral facial nerve palsies following a posterior fossa exploration confined to an extradural compartment. There are different theories to explain this presentation, but the exact mechanism remains unclear. We propose that this patient cranial nerve palsies developed following cerebrospinal fluid (CSF) leak, potentially as a consequence of rapid change in CSF dynamics. PMID:26951144

Traumatic acute subdural haematomas of the posterior fossa: clinicoradiological analysis of 24 patients.

PubMed

d'Avella, D; Servadei, F; Scerrati, M; Tomei, G; Brambilla, G; Massaro, F; Stefini, R; Cristofori, L; Conti, A; Cardali, S; Tomasello, F

2003-12-01

We report 24 patients with a traumatic acute subdural haematoma of the posterior fossa managed between 1997 and 1999 at 8 Italian neurosurgical centres. Each centre provided data about patients' clinico-radiological findings, management, and outcomes, which were retrospectively reviewed. A poor result occurred in 14 patients (58.3%). Ten patients (41.7%) had favourable results. Patients were divided into two groups according to their admission Glasgow Coma Scale (GCS) scores. In Group 1 (12/24 cases; GCS score, > or =8), the outcome was favourable in 75% of cases. In Group 2 (12/12 cases; GCS score, <8), the outcome was poor in 91.6% of cases. Nineteen patients underwent posterior fossa surgery. Factors correlating to outcome were GCS score, status of the basal cisterns and the fourth ventricle, and the presence of supratentorial hydrocephalus. Multivariate analysis showed significant independent prognostic effect only for GCS score (P<0.05). acute posterior fossa subdural haematomas can be divided into two distinct groups: those patients admitted in a comatose state and those with a moderate/mild head injury on admission. Comatose patients present usually with signs of posterior fossa mass effect and have a high percentage of bad outcomes. On the contrary, patients admitted with a GCS of 8 or higher are expected to recover. In these patients the thickness of the haematoma (<1 cm) seems to be a guide to indicate surgical evacuation of the haematoma.

NAS: The first year

NASA Technical Reports Server (NTRS)

Bailey, F. R.; Kutler, Paul

1988-01-01

Discussed are the capabilities of NASA's Numerical Aerodynamic Simulation (NAS) Program and its application as an advanced supercomputing system for computational fluid dynamics (CFD) research. First, the paper describes the NAS computational system, called the NAS Processing System Network, and the advanced computational capabilities it offers as a consequence of carrying out the NAS pathfinder objective. Second, it presents examples of pioneering CFD research accomplished during NAS's first operational year. Examples are included which illustrate CFD applications for predicting fluid phenomena, complementing and supplementing experimentation, and aiding in design. Finally, pacing elements and future directions for CFD and NAS are discussed.

Severe macroglossia after posterior fossa and craniofacial surgery in children.

PubMed

Bouaoud, J; Joly, A; Picard, A; Thierry, B; Arnaud, E; James, S; Hennessy, I; McGarvey, B; Cairet, P; Vecchione, A; Vergnaud, E; Duracher, C; Khonsari, R H

2018-04-01

Massive swelling of the tongue can occur after posterior fossa and craniofacial surgery. Several hypotheses have been proposed to explain the occurrence of such severe postoperative macroglossia, but this phenomenon is still poorly understood. Severe postoperative macroglossia can be a life-threatening condition due to upper airway obstruction. Three cases of severe postoperative macroglossia that occurred after cervical spine, craniofacial, and posterior fossa surgical procedures are reported here. These cases required specialized maxillofacial management and a prolonged stay in the intensive care unit. Causal factors involved in this condition are reported, in order to highlight appropriate prevention and treatment options adapted to the management of paediatric patients. An overview of the current literature on severe postoperative macroglossia in paediatric populations is also provided. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Infraorbital Foramen and Pterygopalatine Fossa Location in Dry Skulls: Anatomical Guidelines for Local Anesthesia

PubMed Central

2017-01-01

Purpose The aim of the study was to locate the infraorbital foramen (IOF) in relation to the infraorbital margin (IOM) for proper injections of local anesthetics in skull specimens. Another aim was to determine the depth of needle penetration into pterygopalatine fossa through the greater palatine canal (GPC). Materials and Methods 102 skull halves were used to measure the distances between (1) IOF and IOM and (2) IOF and alveolar ridge of maxilla at second premolar. Needles were inserted and bent at a 45° angle, passing through the GPC at the level of hard palate. The depth of the tip of needle emerging out of GPC into pterygopalatine fossa was measured. Results The mean distance between IOF and IOM was 6.46 ± 1.57 mm on the right side and 6.74 ± 1.72 mm on the left. The mean distance between IOF and alveolar bone process of the maxilla at second premolar was 29.07 ± 3.58 mm on the right side and 29.39 ± 3.78 mm on the left. The mean depth of penetration of the needle into the pterygopalatine fossa was similar on both sides. Conclusions Proper identification of IOF and pterygopalatine fossa is of great significance during local anesthesia injections, due to their close proximity to vital anatomic structures. PMID:29410916

A systematic review of neuropsychological outcomes following posterior fossa tumor surgery in children.

PubMed

Hanzlik, Emily; Woodrome, Stacey E; Abdel-Baki, Mohamed; Geller, Thomas J; Elbabaa, Samer K

2015-10-01

Central nervous system tumors are the most common solid tumors in the pediatric population. As children with central nervous system (CNS) tumors are surviving into adolescence and adulthood, more research is being focused on the long-term cognitive outcomes of the survivors. This review examines the literature on different cognitive outcomes of survivors of different childhood posterior fossa CNS tumor types. The authors reviewed the literature for articles published from 2000 to 2012 about long-term neuropsychological outcomes of children diagnosed with posterior fossa brain tumors before the age of 18, which distinguished between histological tumor types, and had a minimum follow-up of 3 years. The literature search returned 13 articles, and a descriptive analysis was performed comparing intelligence quotient (IQ), attention/executive function, and memory components of 456 survivors of childhood posterior fossa tumors. Four articles directly compared astrocytoma and medulloblastoma survivors and showed medulloblastoma survivors fared worse in IQ, attention/executive function, and memory measurements. Five articles reporting medulloblastomas found IQ, attention, and memory scores to be significantly below the standardized means. Articles examining astrocytoma survivors found IQ scores within the normal range for the population. Survivors of ependymomas reported 2/23 survivors impaired on IQ scores, while a second study reported a significant number of ependymoma survivors lower than the expected population norm. Tumor histopathology and the type of postoperative adjuvant therapy seem to have a significant impact on the long-term neuropsychological complications of pediatric posterior fossa CNS tumor survivors. Age at diagnosis and treatment factors are important variables that affect the outcomes of the survivors.

Endoscopic third ventriculostomy and posterior fossa tumors.

PubMed

Di Rocco, Federico; Jucá, Carlos Eduardo; Zerah, Michel; Sainte-Rose, Christian

2013-02-01

The management of hydrocephalus associated with a posterior fossa tumor is debated. Some authors emphasize the advantages of an immediate tumor removal that may normalize the cerebrospinal fluid (CSF) dynamics. However, in clinical practice, the mere excision of the lesion has been demonstrated to be accompanied by a persisting hydrocephalus in about one third of the cases. Preoperative endoscopic third ventriculostomy (ETV) offers several advantages. It may control the intracranial pressure (ICP), avoid the necessity of an emergency procedure, allow appropriate scheduling of the operation for tumor removal, and eliminate the risks related to the presence of an external drainage. The procedure also reduces the incidence of postoperative hydrocephalus. A final advantage, more difficult to weight, but obvious to the neurosurgeon, is the possibility to remove the lesion with a relaxed brain and normal ICP. In the postoperative phase, ETV can be used in case of persisting hydrocephalus, both in patients who underwent only the excision of the tumor and in those whose preoperative ETV failed as a consequence of intraventricular bleeding with secondary closure of the stoma (redoETV). The main advantage of postoperative ETV is that the procedure is carried out only in case of persisting hydrocephalus; its use is consequently more selective than preoperative ETV. The disadvantage consists in the common use of an external CSF drainage in the first few postoperative days, which is necessary to control the pressure and for ruling out those cases that reach a spontaneous cure of the hydrocephalus. The authors review the criteria for patient selection and the results of ETV performed in case of hydrocephalus secondary to a posterior fossa tumor. Preoperative ETV constitutes an effective procedure for controlling the hydrocephalus associated with posterior fossa tumors. It might lower the rate of persistent postoperative hydrocephalus and result in a short hospital stay. Low

Unilateral abducens and bilateral facial nerve palsies associated with posterior fossa exploration surgery.

PubMed

Khalil, Ayman; Clerkin, James; Mandiwanza, Tafadzwa; Green, Sandra; Javadpour, Mohsen

2016-03-06

Multiple cranial nerves palsies following a posterior fossa exploration confined to an extradural compartment is a rare clinical presentation. This case report describes a young man who developed a unilateral abducens and bilateral facial nerve palsies following a posterior fossa exploration confined to an extradural compartment. There are different theories to explain this presentation, but the exact mechanism remains unclear. We propose that this patient cranial nerve palsies developed following cerebrospinal fluid (CSF) leak, potentially as a consequence of rapid change in CSF dynamics. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2016.

Posterior fossa meningiomas: surgical experience in 161 cases.

PubMed

Roberti, F; Sekhar, L N; Kalavakonda, C; Wright, D C

2001-07-01

We report the clinical, radiological, and surgical findings of patients with posterior fossa meningiomas surgically treated at our institution over the last 6 years. We reviewed 161 consecutive cases of posterior fossa meningiomas operated on between April 1993 and April 1999 at The George Washington University Medical Center. There were 128 female and 33 male patients (mean age 47 years, range of 10-81 years). Meningiomas were classified as petroclival (110 cases), foramen magnum (21 cases), cerebellar hemispheric, lateral tentorial (14 cases), cerebellopontine angle (9 cases), and jugular foramen (7 cases). Mean tumor equivalent diameter (TED) = (D1xD2xDE)(1/3) was 3.1 cm (range of 0.53-8.95). Head pain (50% of cases) and disturbance of gait (44%) were the most common presenting symptoms, and cranial neuropathies the most common neurological signs on admission. Mean preoperative performance status (Karnofsky scale) was 80.2 (range 40-100). Surgical approaches to these tumors included partial labyrinthectomy petrous apicectomy, fronto-temporal/fronto-temporal orbitozygomatic osteotomy, retrosigmoidal, extreme lateral, transpetrosal, and combined. In 38 cases a staged procedure was performed. Gross-total resection was achieved in 57% of patients, and subtotal/partial in 43%. Surgical mortality was 2.5% and complications were encountered in 41% of patients. Postoperative CSF leak occurred in 22 cases (13.6%). The mean follow-up was 19 months, ranging from 0.2 to 63.6, and the mean performance status of patients with a follow-up of at least 12 months was 77 (range of 40-100). Recurrence or progression of disease was found in 13.7% of cases (follow-up 2 years or more). Our experience suggests that although posterior fossa meningiomas represent a continuing challenge for contemporary neurosurgeons, such tumors may be completely or subtotally removed with low rate of mortality and acceptable morbidity, allowing most of these patients to achieve a good outcome in a long

Arterial relationships to the nerves and some rigid structures in the posterior cranial fossa.

PubMed

Surchev, N

2008-09-01

The close relationships between the cranial nerves and the arterial vessels in the posterior cranial fossa are one of the predisposing factors for artery-nerve compression. The aim of this study was to examine the relationships of the vertebral and basilar arteries to some skull and dural structures and the nerves in the posterior cranial fossa. For this purpose, the skull bases and brains of 70 cadavers were studied. The topographic relationships of the vertebral and basilar arteries to the cranial nerves in the posterior cranial fossa were studied and the distances between the arteries and some osseous formations were measured. The most significant variations in arterial position were registered in the lower half of the basilar artery. Direct contact with an artery was established for the hypoglossal canal, jugular tubercle, and jugular foramen. The results reveal additional information about the relationships of the nerves and arteries to the skull and dural formations in the posterior cranial fossa. New quantitative information is given to illustrate them. The conditions for possible artery-nerve compression due to arterial dislocation are discussed and two groups (lines) of compression points are suggested. The medial line comprises of the brain stem points, usually the nerve root entry/exit zone. The lateral line includes the skull eminences, on which the nerves lie, or skull and dural foramina through which they exit the cranial cavity. (c) 2008 Wiley-Liss, Inc.

Properties of the Medussae Fossae Formation and its relation to the volcanic history of Mars

NASA Astrophysics Data System (ADS)

Ivanov, Anton B.; Cantini, Federico

2016-10-01

Medussae Fossae (MFF) is a well known formation, stretching west of Tharsis volanoes. It is characterized as a relatively young Amazonian units (Amm, Amu), due to widespread signs of erosion. Earth based imaging radar observations at 3.5 cm [1] and 12 cm [2] have discovered a dark radar feature (Stealth), which roughly correlates with the MFF outline.Recent investigations [3], suggested that the unit emplacement is in fact during Hesperian period, but it is composed of material that can be easily eroded. It is not clear when the erosion happened and if it is a continuing process. Hypotheses on MFF formation range from volcanic material emplacement (ash flow tuffs or pyroclastic materials) to an ice-rich dusty mantle, deposited during high obliquity.In this work, we will present the latest observations of the East Medussae Fossae formation by the long wavelength MARSIS radar, continuing the work reported in [4], as well as complementing data surveyed by SHARAD data in [5]. The MARSIS radar has detected strong subsurface interfaces in the areas of Gordi and Eumenides Dorsae at depths up to 1.5km. We will present our analysis of the data, inferring the dielectric properties of the material to constrain properties of the material constituting the Medusae Fossae formation. We will also demonstrate an efficient user interface to work with MARSIS data inside a Geographical Information System (GIS).The research leading to these results has received funding from the European Unions Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement 607379.[1] D. Muhleman, et al., "Radar images of mars," Science, vol. 253, no. 5027, 1991.[2] J. K. Harmon, et al., "Arecibo radar imagery of Mars: The major volcanic provinces," Icarus, vol. 220, aug 2012.[3] L. Kerber, et al., "The dispersal of pyroclasts from Apollinaris Patera, Mars: Implications for the origin of the Medusae Fossae Formation," Icarus, vol. 216, nov 2011.[4] T. R. Watters, et al., "Radar Sounding of the

Transperineal ultrasound-guided implantation of electromagnetic transponders in the prostatic fossa for localization and tracking during external beam radiation therapy.

PubMed

Garsa, Adam A; Verma, Vivek; Michalski, Jeff M; Gay, Hiram A

2014-01-01

To describe a transperineal ultrasound-guided technique for implantation of electromagnetic transponders into the prostatic fossa. Patients were placed in the dorsal lithotomy position, and local anesthetic was administered. On ultrasound, the bladder, urethra, vesicourethral anastomosis, rectum, and the prostatic fossa were carefully identified. Three transponders were implanted into the prostatic fossa under ultrasound guidance in a triangular configuration and implantation was verified by fluoroscopy. Patients underwent computed tomography (CT) simulation approximately 1 week later. All patients in this study were subsequently treated with intensity modulated radiation therapy (IMRT) to the prostatic fossa. From 2008 to 2012, 180 patients received transperineal implantation of electromagnetic transponders into the prostatic fossa and subsequently received IMRT. There were no cases of severe hematuria or rectal bleeding requiring intervention. There were no grade 3 or 4 toxicities. Three patients (1.7%) had a transponder missing on the subsequent CT simulation. Thirteen patients (7.3%) had transponder migration with a geometric residual that exceeded 2 mm for 3 consecutive days (5.6%) or rotation that exceeded 10 degrees for 5 consecutive days (1.7%). These patients underwent a resimulation CT scan to identify the new transponder coordinates. A transperineal technique for implantation of electromagnetic transponders into the prostatic fossa is safe and well tolerated, with no severe toxicity after implantation. There is a low rate of transponder loss or migration.

Prostatic fossa gauze-packing in the prevention of blood clot obstruction of the bladder after transvesical prostatectomy.

PubMed

Umunna, J I

2010-01-01

Clot obstruction often complicates transvesical prostatectomy. Any measure that prevents this will be a great relief to both surgeon and patient. To demonstrate that packing the prostatic fossa with roller gauze bandage after transvesical prostatectomy can prevent post-operative clot blockage of bladder drainage . Charts of all patients who had transvesical prostatectomy at Jasman Hospital Udo by me from 1988 to 1997 were sorted into two groups , Group A, not packed and Group B, packed. Information sought included patient's age, type of prostatectomy performed, whether the prostatic fossa was packed or not , average duration of catheter drainage, and complications. There were 68 patients who had no fossa packing and 72 in Group B with fossa packing. The age range of the two groups A and B were respective 45-85 year-old and 50-83 years. In both groups the highest number of patients was in the 60 t0 79 age bracket (48 in group A , 70%, and 56 in group B (78%). Bladder blockage occurred in 32(47%) patients without packing and none (0%) in group B with packing. Average duration of bladder drainage was 14 days in each group. There was no persisting vesico-cutaneous fistula. Temporary urinary incontinence occurred in three (3%) patients who had no packing and in five (7%) with packing. Gauze-packing of the prostatic fossa during transvesical prostatectomy can prevent bladder obstruction from clot retention without undue complications.

Growing skull fracture of the posterior cranial fossa and of the orbital roof.

PubMed

Caffo, M; Germanò, A; Caruso, G; Meli, F; Calisto, A; Tomasello, F

2003-03-01

Growing Skull Fractures (GSF) are rare complications of head trauma, primarily reported in infancy and early childhood. GSF are commonly located on calvaria, and rarely in other locations, including the skull base. In this study, we report two cases of GSF occurring in unusual locations. The first, a 8-month old girl, with a GSF of the suboccipital posterior fossa region, and the second, a 4-year old boy with a GSF of the right orbital roof. Both cases underwent operative treatment of the GSF, with microsurgical dissection and excision of the protruding gliotic brain tissue, watertight duraplasty and autologous bone cranial repair. The authors conducted a Medline search of the relevant English literature from 1966 to 2002. From the search, three cases of suboccipital posterior fossa region GSF and twelve series of orbital GSF, describing a total of 22 cases, have been found. A survey of the pathogenic mechanisms underlying this entity in these locations is reported. A review of suboccipital posterior fossa and orbital roof GSF cases, of nosological, ophthalmological and neurological data, neuroradiological and operative findings, and results of different treatment strategies are described.

Pressure Sore at an Unusual Site- the Bilateral Popliteal Fossa: A Case report

PubMed Central

Kataria, Kamal; Sagar, Sushma; Singhal, Manish; Yadav, Rajni

2012-01-01

Pressure sore is tissue ulceration due to unrelieved pressure, altered sensory perception, and exposure to moisture. Geriatric patients with organic problems and patients with spinal cord injuries are the high-risk groups. Soft tissues over bony prominences are the common sites for ulcer development. About 95% of pressure ulcers occur in the lower part of the body. Ischial tuberosity, greater trochanter, sacrum and heel are common sites. In addition to these, pressure sores at unusual sites like nasal alae, malar eminences, cervical region and medial side of knee have also been described. Only 1.6% of the patients present with sores in areas outside the pelvis and lower extremity. In a paraplegic patient, pressure sores are usually over extensor surface of knee and heel but pressure ulcer over popliteal fossa are extremely rare. We herein report a case of a 36-years-old diabetic and paraplegic male, who presented with multiple bed sores involving the sacral area, heels and bilateral popliteal fossa. Popliteal fossa is an unusual site for pressure sores. Only one similar case has been previously reported in the literature. PMID:29181131

Management of the stricture of fossa navicularis and pendulous urethral strictures

PubMed Central

Singh, Shrawan K.; Agrawal, Santosh K.; Mavuduru, Ravimohan S.

2011-01-01

Objective: Management of distal anterior urethral stricture is a common problem faced by practicing urologists. Literature on urethral stricture mainly pertains to bulbar urethral stricture and pelvic fracture urethral distraction defect. The present article aims to review the management of the strictures of fossa navicularis and pendulous urethra. Materials and Methods: The literature in English language was searched from the National Library of Medicine database, using the appropriate key words for the period 1985-2010. Out of 475 articles, 115 were selected for the review based on their relevance to the topic. Results: Etiology of stricture is shifting from infective to inflammatory and iatrogenic causes. Stricture of fossa navicularis is most often caused by lichen sclerosus et atrophicus and instrumentation. Direct visual internal urethrotomy is limited to selected cases in the management of pendulous urethral stricture. With experience and identification of various prognostic factors, conservative management by dilatation and internal urethrotomy is being replaced by various reconstructive procedures, using skin flaps and grafts with high success rates. Single-stage urethroplasty is preferred over the 2-stage procedure as the latter disfigures the penis and poses sexual problems temporarily. Conclusions: Flaps or grafts are useful for single-stage reconstruction of fossa navicularis and pendulous urethral strictures. The buccal and lingual mucosa serves as a preferred resource material for providing the inner lining of the urethra. Off-the-shelf materials, such as acellular collagen matrix, are promising. PMID:22022062

Resection in the popliteal fossa for metastatic melanoma.

PubMed

Marone, Ugo; Caracò, Corrado; Chiofalo, Maria Grazia; Botti, Gerardo; Mozzillo, Nicola

2007-01-19

Traditionally metastatic melanoma of the distal leg and the foot metastasize to the lymph nodes of the groin. Sometimes the first site of nodal disease can be the popliteal fossa. This is an infrequent event, with rare reports in literature and when it occurs, radical popliteal node dissection must be performed. We report a case of a 36-year old man presented with diagnosis of 2 mm thick, Clark's level II-III, non ulcerated melanoma of the left heel, which developed during the course of the disease popliteal node metastases, after a superficial and deep groin dissection for inguinal node involvement. Five months after popliteal lymph node dissection he developed systemic disease, therefore he received nine cycles of dacarbazine plus fotemustine. To date (56 months after prior surgery and 11 months after chemotherapy) he is alive with no evidence of disease. In case of groin metastases from melanoma of distal lower extremities, clinical and ultrasound examination of ipsilateral popliteal fossa is essential. When metastatic disease is found, radical popliteal dissection is the standard of care. Therefore knowledge of anatomy and surgical technique about popliteal lymphadenectomy are required to make preservation of structures that if injured, can produce a permanent, considerable disability.

Resection in the popliteal fossa for metastatic melanoma

PubMed Central

Marone, Ugo; Caracò, Corrado; Chiofalo, Maria Grazia; Botti, Gerardo; Mozzillo, Nicola

2007-01-01

Background Traditionally metastatic melanoma of the distal leg and the foot metastasize to the lymph nodes of the groin. Sometimes the first site of nodal disease can be the popliteal fossa. This is an infrequent event, with rare reports in literature and when it occurs, radical popliteal node dissection must be performed. Case presentation We report a case of a 36-year old man presented with diagnosis of 2 mm thick, Clark's level II-III, non ulcerated melanoma of the left heel, which developed during the course of the disease popliteal node metastases, after a superficial and deep groin dissection for inguinal node involvement. Five months after popliteal lymph node dissection he developed systemic disease, therefore he received nine cycles of dacarbazine plus fotemustine. To date (56 months after prior surgery and 11 months after chemotherapy) he is alive with no evidence of disease. Conclusion In case of groin metastases from melanoma of distal lower extremities, clinical and ultrasound examination of ipsilateral popliteal fossa is essential. When metastatic disease is found, radical popliteal dissection is the standard of care. Therefore knowledge of anatomy and surgical technique about popliteal lymphadenectomy are required to make preservation of structures that if injured, can produce a permanent, considerable disability. PMID:17239242

Comparison between magnetic resonance imaging and fetopathology in the evaluation of fetal posterior fossa non-cystic abnormalities.

PubMed

Tilea, B; Delezoide, A L; Khung-Savatovski, S; Guimiot, F; Vuillard, E; Oury, J F; Garel, C

2007-06-01

To compare magnetic resonance imaging (MRI) and fetopathological findings in the evaluation of non-cystic fetal posterior fossa anomalies and to describe associated abnormalities. This was a prospective study from 2000 to 2005 of fetuses identified on ultrasound as having sonographic suspicion of posterior fossa malformation. All underwent a thorough MRI examination of the fetal brain, after which we classified each fetus as presenting one of the following pathologies: vermian hypoplasia or agenesis, cerebellar and/or brain stem hypoplasia, destructive or dysplastic lesions. All of the pregnancies were then terminated, after which the whole fetus underwent fetopathological examination. We compared the findings from MRI and fetopathological examinations and recorded the associated cerebral and extracerebral abnormalities. Twenty-five fetuses were included. MRI was performed at a mean gestational age of 31 weeks, and fetopathological examination at 33 weeks. In 12 cases we observed vermian hypoplasia, six had partial vermian agenesis, 11 had cerebellar hemisphere hypoplasia, seven had brain stem hypoplasia, four had destructive lesions and six had dysplastic lesions. The two techniques were similar in their performance with respect to the detection of vermian agenesis, brain stem hypoplasia and destructive lesions. There were four false-positive results of MRI for vermian hypoplasia and a poor agreement regarding cerebellar hemisphere hypoplasia. No dysplastic lesions were diagnosed by MRI. None of the posterior fossa malformations was isolated and many cerebral and extracerebral abnormalities were found. A systematic analysis of the posterior fossa in fetal MRI makes it possible to diagnose accurately most posterior fossa malformations. These malformations never occurred in isolation in our study.

Visible and Near-Infrared Spectroscopy of Hephaestus Fossae Cratered Cones, Mars

NASA Astrophysics Data System (ADS)

Dapremont, A.; Wray, J. J.

2017-12-01

Hephaestus Fossae are a system of sub-parallel fractures on Mars (> 500 km long) interpreted as near-surface tensional cracks [1]. Images of the Martian surface from the High Resolution Imaging Science Experiment have revealed cratered cones within the Hephaestus Fossae region. A volcanic origin (cinder/tuff cones) has been proposed for these features based on morphometric measurements and fine-scale surface characteristics [2]. In an effort to further constrain the origin of these cones as the products of igneous or sedimentary volcanism, we use data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). We take advantage of CRISM's S (0.4 - 1.0 microns) and L (1.0 - 3.9 microns) detector wavelength ranges to investigate the presence or absence of spectral signatures consistent with previous identifications of igneous and mud volcanism products on Mars [3,4]. Hephaestus Fossae cratered cone rims exhibit a consistent nanophase ferric oxide signature. We also identify ferrous phases and 3-micron absorptions (attributed to fundamental vibrational stretch frequencies in H2O) on the crater rims of several cones. Mafic signatures on cratered cone rims support an igneous provenance for these features. The 3-micron absorptions are consistent with the presence of structurally bound or adsorbed water. Our CRISM observations are similar to those of small edifice features in Chryse Planitia, which were interpreted as mud volcanism products based on their enrichment of nanophase ferric minerals and 3-micron absorptions on summit crater rims [3]. Hydrothermal activity was invoked for a Coprates Chasma pitted cone (scoria/tuff cone) based on CRISM identification of partially dehydrated opaline silica, which we do not observe in Hephaestus Fossae [4]. Our spectral observations are more consistent with mud volcanism, but we do not definitively rule out an igneous volcanic origin for the cones in our study region. We demonstrate that VNIR spectroscopy is a valuable

Morphometric features of posterior cranial fossa are different between Chiari I malformation with and without syringomyelia.

PubMed

Yan, Huang; Han, Xiao; Jin, Mengran; Liu, Zhen; Xie, Dingding; Sha, Shifu; Qiu, Yong; Zhu, Zezhang

2016-07-01

To investigate whether the posterior cranial fossa (PCF) morphology in Chiari I malformation without syringomyelia (also called syrinx) (CMI-only) is different from that in Chiari I malformation with syrinx (CMI-S). Nineteen CMI patients without syrinx constituted the CMI-only group, whereas 48 CMI patients with syrinx were assigned to the CMI-S group. Another cohort of 40 age-matched asymptomatic adolescents was enrolled to serve as the control group. Six measurements were evaluated and compared between these three groups from T1-weighted magnetic resonance (MR) imaging, including the length of the clivus (AB), the anteroposterior diameter of the foramen magnum (BC), the length of the supraocciput (CD), the anteroposterior diameter of the posterior fossa (DA), the posterior fossa height (BE) and the clivus gradient ([Formula: see text]). The posterior cranial fossa morphology in relation to syrinx severity was also investigated. Compared to the normal controls, the AB, CD, DA, BE and [Formula: see text] were significantly larger in the CMI-S group. Similar changes in AB, CD, DA and BE were also demonstrated in the CMI-only group, while the clivus gradient ([Formula: see text]) was found to be normal when compared with the control group. A significantly decreased clivus gradient was observed in the CMI-S group as compared to CMI-only group. In addition, the clivus was significantly flattened in patients with a distended-syrinx in comparison to those with a non-distended syrinx. Small size of the posterior fossa was detected both in CMI cases with and without syrinx. The clivus gradient served as the only morphologic difference in the PCF between CMI-S and CMI-only patients and was correlated with the severity of the syrinx, may support the theory that the restricted circulation of cerebrospinal fluid at the anterior paramedial subarachnoid space contributes to the formation of a syrinx.

Western Medusa Fossae Formation: Dust and Dunes

NASA Image and Video Library

2015-09-16

This beautifully contrasted infrared-color image shows an area approximately 600 by 900 meters. This is a close-up from NASA Mars Reconnaissance Orbiter spacecraft of the western Medusa Fossae formation where we can see dust-covered rocky, bedrock surfaces beige and a bluish-tinted sand sheet that transitions into several dunes. The bluish sand is thought to originate from the bedrock that lies beneath the dust. If true, this has implications for the composition of the formation, which has been highly debated over the years. http://photojournal.jpl.nasa.gov/catalog/PIA19939

Comparison of posterior fossa volumes and clinical outcomes after decompression of Chiari malformation Type I.

PubMed

Khalsa, Siri Sahib S; Siu, Alan; DeFreitas, Tiffani A; Cappuzzo, Justin M; Myseros, John S; Magge, Suresh N; Oluigbo, Chima O; Keating, Robert F

2017-05-01

OBJECTIVE Previous studies have indicated an association of Chiari malformation Type I (CM-I) and a small posterior fossa. Most of these studies have been limited by 2D quantitative methods, and more recent studies utilizing 3D methodologies are time-intensive with manual segmentation. The authors sought to develop a more automated tool to calculate the 3D posterior fossa volume, and correlate its changes after decompression with surgical outcomes. METHODS A semiautomated segmentation program was developed, and used to compare the pre- and postoperative volumes of the posterior cranial fossa (PCF) and the CSF spaces (cisterna magna, prepontine cistern, and fourth ventricle) in a cohort of pediatric patients with CM-I. Volume changes were correlated with postoperative symptomatic improvements in headache, syrinx, tonsillar descent, cervicomedullary kinking, and overall surgical success. RESULTS Forty-two pediatric patients were included in this study. The mean percentage increase in PCF volume was significantly greater in patients who showed clinical improvement versus no improvement in headache (5.89% vs 1.54%, p < 0.05) and tonsillar descent (6.52% vs 2.57%, p < 0.05). Overall clinical success was associated with a larger postoperative PCF volume increase (p < 0.05). These clinical improvements were also significantly associated with a larger increase in the volume of the cisterna magna (p < 0.05). The increase in the caudal portion of the posterior fossa volume was also larger in patients who showed improvement in syrinx (6.63% vs 2.58%, p < 0.05) and cervicomedullary kinking (9.24% vs 3.79%, p < 0.05). CONCLUSIONS A greater increase in the postoperative PCF volume, and specifically an increase in the cisterna magna volume, was associated with a greater likelihood of clinical improvements in headache and tonsillar descent in patients with CM-I. Larger increases in the caudal portion of the posterior fossa volume were also associated with a greater likelihood of

The Lost City Hydrothermal Field: A Spectroscopic and Astrobiological Analogue for Nili Fossae, Mars

NASA Astrophysics Data System (ADS)

Amador, Elena S.; Bandfield, Joshua L.; Brazelton, William J.; Kelley, Deborah

2017-11-01

Low-temperature serpentinization is a critical process with respect to Earth's habitability and the Solar System. Exothermic serpentinization reactions commonly produce hydrogen as a direct by-product and typically produce short-chained organic compounds indirectly. Here, we present the spectral and mineralogical variability in rocks from the serpentine-driven Lost City Hydrothermal Field on Earth and the olivine-rich region of Nili Fossae on Mars. Near- and thermal-infrared spectral measurements were made from a suite of Lost City rocks at wavelengths similar to those for instruments collecting measurements of the martian surface. Results from Lost City show a spectrally distinguishable suite of Mg-rich serpentine, Ca carbonates, talc, and amphibole minerals. Aggregated detections of low-grade metamorphic minerals in rocks from Nili Fossae were mapped and yielded a previously undetected serpentine exposure in the region. Direct comparison of the two spectral suites indicates similar mineralogy at both Lost City and in the Noachian (4-3.7 Ga) bedrock of Nili Fossae, Mars. Based on mapping of these spectral phases, the implied mineralogical suite appears to be extensive across the region. These results suggest that serpentinization was once an active process, indicating that water and energy sources were available, as well as a means for prebiotic chemistry during a time period when life was first emerging on Earth. Although the mineralogical assemblages identified on Mars are unlikely to be directly analogous to rocks that underlie the Lost City Hydrothermal Field, related geochemical processes (and associated sources of biologically accessible energy) were once present in the subsurface, making Nili Fossae a compelling candidate for a once-habitable environment on Mars.

Posterior fossa reconstruction using titanium plate for the treatment of cerebellar ptosis after decompression for Chiari malformation.

PubMed

Udani, Vikram; Holly, Langston T; Chow, Daniel; Batzdorf, Ulrich

2014-01-01

We describe our use of a perforated titanium plate to perform a partial posterior fossa cranioplasty in the treatment of cerebellar ptosis and dural ectasia after posterior fossa decompression (PFD). Twelve patients who had undergone PFD underwent posterior fossa reconstruction using a titanium plate. Symptoms were related to either descent of the cerebellum into the decompression or to dural ectasia into the craniectomy defect. Twelve patients who had undergone large suboccipital craniectomies and who presented with persistent headaches and some with neurological symptoms related to syringomyelia, underwent reoperation with placement of a small titanium plate. Ten of 12 patients showed symptomatic improvement after reoperation. Placement of a titanium plate appears to be an effective method of treatment of cerebellar ptosis and dural ectasia after PFD for Chiari malformation. Copyright © 2014 Elsevier Inc. All rights reserved.

[Extended middle fossa approach in treatment of vestibular schwannoma--technique of surgery and postoperative complications].

PubMed

Jamróz, Barbara; Niemczyk, Kazimierz; Morawski, Krzysztof; Bartoszewicz, Robert

2010-06-01

The main tumor of cerebellopontine angle are vestibular schwannoma (80-90%). According to National Institute of Health Consensus Development Conference the best treatment method is microsurgery. There are three principal surgical approaches: translabyrinthin, retrosigmoid and middle fossa. Only the latter two approaches provide the possibility of hearing preservation. Technique of surgery and postoperative morbidity after MFA. 39 patients (40 tumor) suffered from tumor of cerebellopontine angle, operated by using middle fossa approach in years 1998-2007. We evaluate hearing preservation and function of facial nerve and others postoperative morbidity. 22.5% of patients has hearing impairment and 32.5% has facial weakness. By individual cases we observed: CSF leak, meningitis, corneal ulceration, ischialgia, wound bleeding and venue thrombosis. 1/3 of patients suffered from headache and disequilibrium and 1/6 suffered from tinnitus. According to NIH middle fossa approach is one of three possible approaches in microsurgery of cerebellopontine angle tumors. There is possible total tumor removal with hearing preservation. Monitoring of facial and cochlear nerve during operation is recommended.

The Lost City Hydrothermal Field: A Spectroscopic and Astrobiological Analogue for Nili Fossae, Mars.

PubMed

Amador, Elena S; Bandfield, Joshua L; Brazelton, William J; Kelley, Deborah

2017-11-01

Low-temperature serpentinization is a critical process with respect to Earth's habitability and the Solar System. Exothermic serpentinization reactions commonly produce hydrogen as a direct by-product and typically produce short-chained organic compounds indirectly. Here, we present the spectral and mineralogical variability in rocks from the serpentine-driven Lost City Hydrothermal Field on Earth and the olivine-rich region of Nili Fossae on Mars. Near- and thermal-infrared spectral measurements were made from a suite of Lost City rocks at wavelengths similar to those for instruments collecting measurements of the martian surface. Results from Lost City show a spectrally distinguishable suite of Mg-rich serpentine, Ca carbonates, talc, and amphibole minerals. Aggregated detections of low-grade metamorphic minerals in rocks from Nili Fossae were mapped and yielded a previously undetected serpentine exposure in the region. Direct comparison of the two spectral suites indicates similar mineralogy at both Lost City and in the Noachian (4-3.7 Ga) bedrock of Nili Fossae, Mars. Based on mapping of these spectral phases, the implied mineralogical suite appears to be extensive across the region. These results suggest that serpentinization was once an active process, indicating that water and energy sources were available, as well as a means for prebiotic chemistry during a time period when life was first emerging on Earth. Although the mineralogical assemblages identified on Mars are unlikely to be directly analogous to rocks that underlie the Lost City Hydrothermal Field, related geochemical processes (and associated sources of biologically accessible energy) were once present in the subsurface, making Nili Fossae a compelling candidate for a once-habitable environment on Mars. Key Words: Mars-Habitability-Serpentinization-Analogue. Astrobiology 17, 1138-1160.

Surgery for juvenile nasopharyngeal angiofibroma with lateral extension to the infratemporal fossa.

PubMed

Yamada, Masato; Tsunoda, Atsunobu; Tokumaru, Takao; Aoyagi, Masaru; Kawano, Yoshihisa; Yano, Tomoyuki; Kishimoto, Seiji

2014-08-01

The study aimed to assess the usefulness of skull base surgery for large juvenile nasopharyngeal angiofibroma (JNA) with lateral extension to the infratemporal fossa. Eleven cases were enrolled for this study, and the mean age was 17.7 years old (range: 8-32). Six out of 11 cases underwent surgery as an initial treatment, and the other five underwent secondary surgery after initial surgery or radiotherapy in other institutions. The range of extension of tumor, feeding arteries, surgical approach, and treatment outcome were estimated. All tumors originated from the sphenopalatine foramen. Based on the imaging study, there was extension to the cavernous sinus observed in eight cases, as well as to the middle cranial fossa (8), orbit (4), and anterior cranial fossa (1). These tumors were diagnosed as Andrews' Stage IVa (3) and IVb (8). However, infiltration into the cavernous sinus was observed in one case only during surgery. Ten tumors were separated carefully from the cavernous sinus or dura and were accurately diagnosed as Stage IIIb. In all cases, the main arterial feeders of the JNAs were branches of the external carotid artery, which were embolized prior to surgery. However, 10 cases were also fed by branches of the internal carotid artery (branches of the ophthalmic artery), in which these arteries could not be embolized. Coronal skin incision (1) and a facial dismasking flap (9) were used, and in one case, wide lateral skin incision with temporary incision of the facial nerve was applied. The orbito-zygomatic approach and its modification was applied to all the cases. Fronto-lateral craniotomy was applied in four cases and lateral craniotomy in seven cases. Total resection was achieved in 10 cases and subtotal resection in one case. No mortality was noted in this series. Temporal trismus was observed in all cases which subsided gradually. Cheek numbness and facial palsy were observed in three and two cases, respectively. Coupled with craniotomy, tumor removal

The use of wavelet filters for reducing noise in posterior fossa Computed Tomography images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pita-Machado, Reinado; Perez-Diaz, Marlen, E-mail: mperez@uclv.edu.cu; Lorenzo-Ginori, Juan V., E-mail: mperez@uclv.edu.cu

Wavelet transform based de-noising like wavelet shrinkage, gives the good results in CT. This procedure affects very little the spatial resolution. Some applications are reconstruction methods, while others are a posteriori de-noising methods. De-noising after reconstruction is very difficult because the noise is non-stationary and has unknown distribution. Therefore, methods which work on the sinogram-space don’t have this problem, because they always work over a known noise distribution at this point. On the other hand, the posterior fossa in a head CT is a very complex region for physicians, because it is commonly affected by artifacts and noise which aremore » not eliminated during the reconstruction procedure. This can leads to some false positive evaluations. The purpose of our present work is to compare different wavelet shrinkage de-noising filters to reduce noise, particularly in images of the posterior fossa within CT scans in the sinogram-space. This work describes an experimental search for the best wavelets, to reduce Poisson noise in Computed Tomography (CT) scans. Results showed that de-noising with wavelet filters improved the quality of posterior fossa region in terms of an increased CNR, without noticeable structural distortions.« less

Repair of Spontaneous Cerebrospinal Fluid Otorrhea from Defect of Middle Cranial Fossa

PubMed Central

Goh, Young Bum; Han, Chi-Sung

2013-01-01

Spontaneous cerebrospinal fluid (CSF) otorrhea is defined as CSF otorrhea where there are no identifiable causes including previous trauma, surgery, infection, neoplasm or congenital anomaly. The condition is rare. The origin of CSF leak is commonly a defect in the tegmen of the middle cranial fossa. The pathophysiology of spontaneous CSF otorrhea is unclear. Two theories of the etiology of bony defects of the temporal bone are the congenital bony defect theory and arachnoid granulation theory. The authors experienced a case of a 49-year-old female patient admitted with the complaint of persistent right ear fullness. Computed tomography revealed a large defect of the middle fossa and suspicious CSF otorrhea through the defect of tegmen tympani. Repair was successful with multiple bone chips using the transmastoid approach. The postoperative course was good and there has been no recurrence of the CSF leakage. PMID:24653924

UAS-NAS Stakeholder Feedback Report

NASA Technical Reports Server (NTRS)

Randall, Debra; Murphy, Jim; Grindle, Laurie

2016-01-01

The need to fly UAS in the NAS to perform missions of vital importance to national security and defense, emergency management, science, and to enable commercial applications has been continually increasing over the past few years. To address this need, the NASA Aeronautics Research Mission Directorate (ARMD) Integrated Aviation Systems Program (IASP) formulated and funded the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project (hereafter referred to as UAS-NAS Project) from 2011 to 2016. The UAS-NAS Project identified the following need statement: The UAS community needs routine access to the global airspace for all classes of UAS. The Project identified the following goal: To provide research findings to reduce technical barriers associated with integrating UAS into the NAS utilizing integrated system level tests in a relevant environment. This report provides a summary of the collaborations between the UAS-NAS Project and its primary stakeholders and how the Project applied and incorporated the feedback.

[Linear accelerator-based stereotactic radiation treatment of patients with medial middle fossa meningiomas].

PubMed

Golanov, A V; Cherekaev, V A; Serova, N K; Pronin, I N; Gorlachev, G E; Kotel'nikova, T M; Podoprigora, A E; Kudriavtseva, P A; Galkin, M V

2010-01-01

Medial middle fossa meningiomas are challenging for neurosurgical treatment. Invasion of cranial nerves and vessels leads to high risk of complications after removal of such meningiomas. Currently methods of conformal stereotactic radiation treatment are applied wider and wider for the discussed lesions. During a 3.5-year period 80 patients with medial middle fossa meningiomas were treated in Burdenko Moscow Neurosurgical Institute using linear accelerator "Novalis". In 31 case radiation treatment was preceded by surgical resection. In majority of patients symptoms included cranial nerve dysfunction: oculomotor disturbances in 62.5%, trigeminal impairment--in 37.5%, visual deficit--in 43.8%, facial nerve palsy--in 1.25%. 74 patients underwent radiotherapy with classical fractioning, 2--in hypofractionated mode and 4 received radiosurgery. In cases of classical fractioning mean marginal dose reached 46.3 Gy during 28-33 fractions, in hypofractioning (7 fractions)--31.5 Gy, in radiosurgery--16.25 Gy. Mean follow-up period was 18.4 months (6-42 months). Control of tumor growth was achieved in 97.5% of cases (78 patients): in 42 (52.5%) lesion shrinked, in 36 (45%) stabilization was observed. Clinical examination revealed improvement of visual function in 15 patients (18%) and deterioration in 2 (2.5%). No new neuropathies were found. Stereotactic radiation treatment is the method of choice for medial anterior and middle fossa meningiomas due to effective control of tumor progression and minimal rate of complications.

Correlation of Acute and Late Brainstem Toxicities With Dose-Volume Data for Pediatric Patients With Posterior Fossa Malignancies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nanda, Ronica H., E-mail: rhazari@emory.edu; Ganju, Rohit G.; Schreibmann, Edward

Purpose: Radiation-induced brainstem toxicity after treatment of pediatric posterior fossa malignancies is incompletely understood, especially in the era of intensity modulated radiation therapy (IMRT). The rates of, and predictive factors for, brainstem toxicity after photon RT for posterior fossa tumors were examined. Methods and Materials: After institutional review board approval, 60 pediatric patients treated at our institution for nonmetastatic infratentorial ependymoma and medulloblastoma with IMRT were included in the present analysis. Dosimetric variables, including the mean and maximum dose to the brainstem, the dose to 10% to 90% of the brainstem (in 10% increments), and the volume of the brainstemmore » receiving 40, 45, 50, and 55 Gy were recorded for each patient. Acute (onset within 3 months) and late (>3 months of RT completion) RT-induced brainstem toxicities with clinical and radiographic correlates were scored using Common Terminology Criteria for Adverse Events, version 4.0. Results: Patients aged 1.4 to 21.8 years underwent IMRT or volumetric arc therapy postoperatively to the posterior fossa or tumor bed. At a median clinical follow-up period of 2.8 years, 14 patients had developed symptomatic brainstem toxicity (crude incidence 23.3%). No correlation was found between the dosimetric variables examined and brainstem toxicity. Vascular injury or ischemia showed a strong trend toward predicting brainstem toxicity (P=.054). Patients with grade 3 to 5 brainstem toxicity had undergone treatment to significant volumes of the posterior fossa. Conclusion: The results of the present series demonstrate a low, but not negligible, risk of brainstem radiation necrosis for pediatric patients with posterior fossa malignancies treated with IMRT. No specific dose-volume correlations were identified; however, modern treatment volumes might help limit the incidence of severe toxicity. Additional work investigating inherent biologic sensitivity might also

Embolization of dural arteriovenous fistula of the anterior cranial fossa through the middle meningeal artery with Onyx.

PubMed

Deng, Jian-Ping; Li, Jiang; Zhang, Tao; Yu, Jia; Zhao, Zhen-Wei; Gao, Guo-Dong

2014-02-01

Dural arteriovenous fistula (DAVF) of the anterior cranial fossa is usually treated by surgical disconnection or endovascular embolization via the ophthalmic artery. The middle meningeal artery is a rarely used approach. This study investigated the safety and efficacy of embolization of DAVF of the anterior cranial fossa with Onyx through the middle meningeal artery. A retrospective review of a prospective cerebral vascular disease database was performed. Patients with DAVF of the anterior cranial fossa managed with embolization through the middle meningeal artery with Onyx were selected. Information on demography, symptoms and signs, angiographic examinations, interventional treatments, angiographic and clinical results, and follow-up was collected and analyzed. Five patients were included in this study, four of whom had hemorrhage. All fistulas were fed by the bilateral ethmoidal arteries arising from the ophthalmic artery and by the anterior branch of the middle meningeal artery. The abnormal shunt unilaterally drained into the superior sagittal sinus with interposition of the cortical veins all five patients. All endovascular treatments were successful with evidence of an angiographic cure. No complications occurred, and all patients recovered uneventfully without neurologic deficits. There were nearly no symptoms among the patients during follow-up. Embolization of DAVF of the anterior cranial fossa via the middle meningeal artery with Onyx is safe, effective, and a good choice for management of DAVF. More cases are needed to verify these findings. Copyright © 2013. Published by Elsevier B.V.

Primary non-Hodgkin's lymphoma of the infratemporal fossa: a rare case report.

PubMed

Thakur, Jagdeep S; Minhas, Ravinder S; Mohindroo, Narinder K; Sharma, Dev R; Mohindroo, Shobha; Thakur, Anamika

2009-06-21

The head and neck are two of the most common sites of extranodal non-Hodgkin's lymphoma (NHL). However, primary tumors of the infratemporal fossa are infrequent, and NHL in this region is extremely rare. We present a case of a 41-year-old female that presented with swelling in the right preauricular region that had persisted for the past two years. The patient was diagnosed as having a small lymphocytic NHL. She initially underwent chemo-radiation but reported relapse. The tumor was excised and again the patient underwent chemotherapy. The patient remained symptomatic and developed a second primary squamous cell carcinoma in the right retromolar trigone. We discussed NHL with an emphasis on extranodal manifestations. Extranodal NHL that is limited to a single site can be managed by surgery and regular follow up. To the best of our knowledge, this is only the second case of primary NHL of the infratemporal fossa to be reported in the literature.

Effect of Incremental Endoscopic Maxillectomy on Surgical Exposure of the Pterygopalatine and Infratemporal Fossae.

PubMed

Upadhyay, Smita; Dolci, Ricardo L L; Buohliqah, Lamia; Fiore, Mariano E; Ditzel Filho, Leo F S; Prevedello, Daniel M; Otto, Bradley A; Carrau, Ricardo L

2016-02-01

Objective Access to the pterygopalatine and infratemporal fossae presents a significant surgical challenge, owing to their deep-seated location and complex neurovascular anatomy. This study elucidates the benefits of incremental medial maxillectomies to access this region. We compared access to the medial aspect of the infratemporal fossa provided by medial maxillectomy, anteriorly extended medial maxillectomy, endoscopic Denker approach (i.e., Sturmann-Canfield approach), contralateral transseptal approach, and the sublabial anterior maxillotomy (SAM). Methods We studied 10 cadaveric specimens (20 sides) dissecting the pterygopalatine and infratemporal fossae bilaterally. Radius of access was calculated using a navigation probe aligned with the endoscopic line of sight. Area of exposure was calculated as the area removed from the posterior wall of maxillary sinus. Surgical freedom was calculated by computing the working area at the proximal end of the instrument with the distal end fixed at a target. Results The endoscopic Denker approach offered a superior area of exposure (8.46 ± 1.56 cm(2)) and superior surgical freedom. Degree of lateral access with the SAM approach was similar to that of the Denker. Conclusion Our study suggests that an anterior extension of the medial maxillectomy or a cross-court approach increases both the area of exposure and surgical freedom. Further increases can be seen upon progression to a Denker approach.

Effect of Incremental Endoscopic Maxillectomy on Surgical Exposure of the Pterygopalatine and Infratemporal Fossae

PubMed Central

Upadhyay, Smita; Dolci, Ricardo L. L.; Buohliqah, Lamia; Fiore, Mariano E.; Filho, Leo F.S. Ditzel; Prevedello, Daniel M.; Otto, Bradley A.; Carrau, Ricardo L.

2015-01-01

Objective Access to the pterygopalatine and infratemporal fossae presents a significant surgical challenge, owing to their deep-seated location and complex neurovascular anatomy. This study elucidates the benefits of incremental medial maxillectomies to access this region. We compared access to the medial aspect of the infratemporal fossa provided by medial maxillectomy, anteriorly extended medial maxillectomy, endoscopic Denker approach (i.e., Sturmann-Canfield approach), contralateral transseptal approach, and the sublabial anterior maxillotomy (SAM). Methods We studied 10 cadaveric specimens (20 sides) dissecting the pterygopalatine and infratemporal fossae bilaterally. Radius of access was calculated using a navigation probe aligned with the endoscopic line of sight. Area of exposure was calculated as the area removed from the posterior wall of maxillary sinus. Surgical freedom was calculated by computing the working area at the proximal end of the instrument with the distal end fixed at a target. Results The endoscopic Denker approach offered a superior area of exposure (8.46 ± 1.56 cm2) and superior surgical freedom. Degree of lateral access with the SAM approach was similar to that of the Denker. Conclusion Our study suggests that an anterior extension of the medial maxillectomy or a cross-court approach increases both the area of exposure and surgical freedom. Further increases can be seen upon progression to a Denker approach. PMID:26949591

Cysts of the fossa of Rosenmüller: report of two cases.

PubMed

Lloyd, Simon K W; Di Cuffa, Riccardo A; Seymour, Felicity K; Savy, Lloyd E; Grant, Henry R

2010-08-01

Cystic lesions of the nasopharynx are rare. Two cases of mucous retention cysts originating from the fossa of Rosenmüller are described, together with their characteristic radiologic appearance, which allows differentiation from other types of lesions in this region. The differential diagnosis and treatment options are discussed.

Trans-zygomatic middle cranial fossa approach to access lesions around the cavernous sinus and anterior parahippocampus: a minimally invasive skull base approach.

PubMed

Melamed, Itay; Tubbs, R Shane; Payner, Troy D; Cohen-Gadol, Aaron A

2009-08-01

Exposure of the cavernous sinus or anterior parahippocampus often involves a wide exposure of the temporal lobe and mobilization of the temporalis muscle associated with temporal lobe retraction. The authors present a cadaveric study to illustrate the feasibility, advantages and landmarks necessary to perform a trans-zygomatic middle fossa approach to lesions around the cavernous sinus and anterior parahippocampus. The authors performed bilateral trans-zygomatic middle fossae exposures to reach the cavernous sinus and parahippocampus in five cadavers (10 sides). We assessed the morbidity associated with this procedure and compared the indications, advantages, and disadvantages of this method versus more extensive skull base approaches. A vertical linear incision along the middle portion of the zygomatic arch was extended one finger breadth inferior to the inferior edge of the zygomatic arch. Careful dissection inferior to the arch allowed preservation of facial nerve branches. A zygomatic osteotomy was followed via a linear incision through the temporalis muscle and exposure of the middle cranial fossa floor. A craniotomy along the inferolateral temporal bone and middle fossa floor allowed extradural dissection along the middle fossa floor and exposure of the cavernous sinus including all three divisions of the trigeminal nerve. Intradural inspection demonstrated adequate exposure of the parahippocampus. Exposure of the latter required minimal or no retraction of the temporal lobe. The trans-zygomatic middle fossa approach is a simplified skull base exposure using a linear incision, which may avoid the invasivity of more extensive skull base approaches while providing an adequate corridor for resection of cavernous sinus and parahippocampus lesions. The advantages of this approach include its efficiency, ease, minimalism, preservation of the temporalis muscle, and minimal retraction of the temporal lobe.

Clinical studies of photodynamic therapy for malignant brain tumors: facial nerve palsy after temporal fossa photoillumination

NASA Astrophysics Data System (ADS)

Muller, Paul J.; Wilson, Brian C.; Lilge, Lothar D.; Varma, Abhay; Bogaards, Arjen; Fullagar, Tim; Fenstermaker, Robert; Selker, Robert; Abrams, Judith

2003-06-01

In two randomized prospective studies of brain tumor PDT more than 180 patients have been accrued. At the Toronto site we recognized two patients who developed a lower motor neuron (LMN) facial paralysis in the week following the PDT treatment. In both cases a temporal lobectomy was undertaken and the residual tumor cavity was photo-illuminated. The surface illuminated included the temporal fossa floor, thus potentially exposing the facial nerve to the effect of PDT. The number of frontal, temporal, parietal, and occipital tumors in this cohort was 39, 24, 12 and 4, respectively. Of the 24 temporal tumors 18 were randomized to Photofrin-PDT. Of these 18 a temporal lobectomy was carried out exposing the middle fossa floor as part of the tumor resection. In two of the 10 patients where the lobectomy was carried out and the fossa floor was exposed to light there occurred a postoperative facial palsy. Both patients recovered facial nerve function in 6 and 12 weeks, respectively. 46 J/cm2 were used in the former and 130 J/cm2 in the latter. We did not encounter a single post-operative LMN facial plasy in the 101 phase 2 patients treated with Photofrin-PDT. Among 688 supratentorial brain tumor operations in the last decade involving all pathologies and all locations no case of early post-operative LMN facial palsy was identified in the absence of PDT. One further patient who had a with post-PDT facial palsy was identified at the Denver site. Although it is possible that these patients had incidental Bell's palsy, we now recommend shielding the temporal fossa floor during PDT.

Image-interactive orientation in the middle cranial fossa approach to the internal auditory canal: an experimental study.

PubMed

Vrionis, F D; Robertson, J H; Foley, K T; Gardner, G

1997-01-01

Approaches through the middle cranial fossa directed at reaching the internal auditory canal (IAC) invariably employ exposure of the geniculate ganglion, the superior semicircular canal (SSC) or the epitympanum. This involves risk to the facial nerve and hearing apparatus. To minimize this risk, we conducted a laboratory study on 9 cadaver temporal bones by using an image-interactive guidance system (StealthStation) to provide topographic orientation in the middle fossa approach. Surface anatomic fiducials such as the umbo of the tympanic membrane, Henle's spine, the root of the zygoma and various sutures were used as fiducials for registration of CT-images of the temporal bone. Accurate localization of the IAC was achieved in every specimen. Mean target localization error varied from 1.20 to 1.38 mm for critical structures in the temporal bone such as the apex of the cochlea, crus commune, ampula of the SSC and facial hiatus. Our results suggest that frameless stereotaxy may be used as an alternative to current methods in localizing the IAC in patients with small vestibular schwannomas or intractable vertigo undergoing middle fossa surgery.

[A pediatric case of hydatid cyst in the infratemporal fossa].

PubMed

Hiroual, A; Elbouihi, M; Fawzi, S; Lahmiti, S; Aimmadeddine, S; Mansouri-Hattab, N

2014-06-01

Hydatid cyst or disease is an anthropozoonosis due to the development of the larval form of the taenia Echinococcus granulosus in humans. It is endemic in Morocco. The location of a hydatid cyst in the infratemporal fossa (ITF) is extremely rare. The authors report a pediatric case. An 11 year old child was admitted to hospital with a history of left latero-facial swelling gradually increasing in volume for 2 months, CT scan of the face revealed a cystic formation of 7 cm diameter sitting at the left ITF, hydatid serology was negative. A transzygomatic approach allowed the excision of the cyst. The histopathological examination of the resected specimen confirmed the diagnosis of hydatid cyst. The location at the infratemporal fossa of an expansive process such as hydatid cyst in children may have a particular impact on adjacent structures and a more meaningful clinical expression. The rate of growth of hydatid cysts is highly variable and ranges from 1 to 5 cm a year. Hydatid serology is often negative. CT examination is the gold-standard radiological examination. Surgical removal of the hydatid cyst is the most effective treatment. The transzygomatic approach allowed a sufficient access to the cyst and a good quality of excision. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Clay at Nili Fossae

NASA Technical Reports Server (NTRS)

2006-01-01

This image of the Nili Fossae region of Mars was compiled from separate images taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and the High-Resolution Imaging Science Experiment (HiRISE), two instruments on NASA's Mars Reconnaissance Orbiter. The images were taken at 0730 UTC (2:30 a.m. EDT) on Oct. 4, 2006, near 20.4 degrees north latitude, 78.5 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36 to 3.92 micrometers, and shows features as small as 18 meters (60 feet) across. HiRISE's image was taken in three colors, but its much higher resolution shows features as small as 30 centimeters (1 foot) across.

CRISM's sister instrument on the Mars Express spacecraft, OMEGA, discovered that some of the most ancient regions of Mars are rich in clay minerals, formed when water altered the planet's volcanic rocks. From the OMEGA data it was unclear whether the clays formed at the surface during Mars' earliest history of if they formed at depth and were later exposed by impact craters or erosion of the overlying rocks. Clays are an indicator of wet, benign environments possibly suitable for biological processes, making Nili Fossae and comparable regions important targets for both CRISM and HiRISE.

In this visualization of the combined data from the two instruments, the CRISM data were used to calculate the strengths of spectral absorption bands due to minerals present in the scene. The two major minerals detected by the instrument are olivine, a mineral characteristic of primitive igneous rocks, and clay. Areas rich in olivine are shown in red, and minerals rich in clay are shown in green. The derived colors were then overlayed on the HiRISE image.

The area where the CRISM and HiRISE data overlap is shown at the upper left, and is about 5 kilometers (3 miles) across. The three boxes outlined in blue are enlarged to show how the different minerals in the scene match up with different landforms. In the image

Longitudinal MRI assessment: the identification of relevant features in the development of Posterior Fossa Syndrome in children

NASA Astrophysics Data System (ADS)

Spiteri, M.; Lewis, E.; Windridge, D.; Avula, S.

2015-03-01

Up to 25% of children who undergo brain tumour resection surgery in the posterior fossa develop posterior fossa syndrome (PFS). This syndrome is characterised by mutism and disturbance in speech. Our hypothesis is that there is a correlation between PFS and the occurrence of hypertrophic olivary degeneration (HOD) in lobes within the posterior fossa, known as the inferior olivary nuclei (ION). HOD is exhibited as an increase in size and intensity of the ION on an MR image. Intra-operative MRI (IoMRI) is used during surgical procedures at the Alder Hey Children's Hospital, Liver- pool, England, in the treatment of Posterior Fossa tumours and allows visualisation of the brain during surgery. The final MR scan on the IoMRI allows early assessment of the ION immediately after the surgical procedure. The longitudinal MRI data of 28 patients was analysed in a collaborative study with Alder Hey Children's Hospital, in order to identify the most relevant imaging features that relate to the development of PFS, specifically related to HOD. A semi-automated segmentation process was carried out to delineate the ION on each MRI. Feature selection techniques were used to identify the most relevant features amongst the MRI data, demographics and clinical data provided by the hospital. A support vector machine (SVM) was used to analyse the discriminative ability of the selected features. The results indicate the presence of HOD as the most efficient feature that correlates with the development of PFS, followed by the change in intensity and size of the ION and whether HOD occurred bilaterally or unilaterally.

Temporalis myofascial repair of traumatic defects of the anterior fossa. Technical note.

PubMed

Gillespie, R P; Shagets, F W; de los Reyes, R A

1986-06-01

Bilateral temporalis myofascial flaps in continuity with frontal periosteum can be used in repairing extensive dural and bone defects of the anterior cranial fossa floor. The technique of preserving and using this flap is described and offers an alternative to the use of frontal pericranial tissue for repair of anterior dural defects.

Normal fetal posterior fossa in MR imaging: new biometric data and possible clinical significance.

PubMed

Ber, R; Bar-Yosef, O; Hoffmann, C; Shashar, D; Achiron, R; Katorza, E

2015-04-01

Posterior fossa malformations are a common finding in prenatal diagnosis. The objectives of this study are to re-evaluate existing normal MR imaging biometric data of the fetal posterior fossa, suggest and evaluate new parameters, and demonstrate the possible clinical applications of these data. This was a retrospective review of 215 fetal MR imaging examinations with normal findings and 5 examinations of fetuses with a suspected pathologic posterior fossa. Six previously reported parameters and 8 new parameters were measured. Three new parameter ratios were calculated. Interobserver agreement was calculated by using the intraclass correlation coefficient. For measuring each structure, 151-211 MR imaging examinations were selected, resulting in a normal biometry curve according to gestational age for each parameter. Analysis of the ratio parameters showed that vermian lobe ratio and cerebellar hemisphere ratio remain constant with gestational age and that the vermis-to-cisterna magna ratio varies with gestational age. Measurements of the 5 pathologic fetuses are presented on the normal curves. Interobserver agreement was excellent, with the intraclass correlation coefficients of most parameters above 0.9 and only 2 parameters below 0.8. The biometry curves derived from new and existing biometric data and presented in this study may expand and deepen the biometry we use today, while keeping it simple and repeatable. By applying these extensive biometric data on suspected abnormal cases, diagnoses may be confirmed, better classified, or completely altered. © 2015 by American Journal of Neuroradiology.

Head CT: Image quality improvement of posterior fossa and radiation dose reduction with ASiR - comparative studies of CT head examinations.

PubMed

Guziński, Maciej; Waszczuk, Łukasz; Sąsiadek, Marek J

2016-10-01

To evaluate head CT protocol developed to improve visibility of the brainstem and cerebellum, lower bone-related artefacts in the posterior fossa and maintain patient radioprotection. A paired comparison of head CT performed without Adaptive Statistical Iterative Reconstruction (ASiR) and a clinically indicated follow-up with 40 % ASiR was acquired in one group of 55 patients. Patients were scanned in the axial mode with different scanner settings for the brain and the posterior fossa. Objective image quality analysis was performed with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality analysis was based on brain structure visibility and evaluation of the artefacts. We achieved 19 % reduction of total DLP and significantly better image quality of posterior fossa structures. SNR for white and grey matter in the cerebellum were 34 % to 36 % higher, respectively, CNR was improved by 142 % and subjective analyses were better for images with ASiR. When imaging parameters are set independently for the brain and the posterior fossa imaging, ASiR has a great potential to improve CT performance: image quality of the brainstem and cerebellum is improved, and radiation dose for the brain as well as total radiation dose are reduced. •With ASiR it is possible to lower radiation dose or improve image quality •Sequentional imaging allows setting scan parameters for brain and posterior-fossa independently •We improved visibility of brainstem structures and decreased radiation dose •Total radiation dose (DLP) was decreased by 19.

Preauricular infratemporal fossa approach for advanced malignant parotid tumors.

PubMed

Leonetti, John P; Benscoter, Brent J; Marzo, Sam J; Borrowdale, Richard W; Pontikis, George C

2012-09-01

The aims of this study were to demonstrate the surgical technique involved in the preauricular infratemporal fossa (ITF) approach, outline the clinical indications for use of this technique, and present the results in using this approach in 159 patients with malignant parotid tumors. At the conclusion of this article, the reader should be able to understand the utility of the preauricular infratemporal fossa approach in the management of patients with advanced malignant parotid tumors. This was a retrospective chart review of 159 patients treated at a tertiary care academic medical center following institutional review board approval. A comprehensive medical records review was performed for all patients with malignant parotid tumors who underwent a preauricular ITF approach between July 1988 and July 2010. The most common presenting symptoms were pain and trismus, whereas the presence of a parotid mass and facial paralysis were the most common clinical signs. Mucoepidermoid and adenoid cystic carcinoma accounted for 63% of the tumors, and perineural invasion was found in nearly 71% of the patients. Despite negative surgical margins in 92% of the patients, local or regional tumor recurrence was found in 17% of the cases. The mean follow-up time was 12.8 years. The preauricular ITF approach should be used in the surgical extirpation of advanced malignant parotid neoplasms. This technique provides proximal facial nerve identification, internal carotid artery protection, and negative tumor margins at the skull base. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Hemangiopericytoma of the infratemporal fossa: progression toward malignancy in a 30-year history.

PubMed

Brucoli, Matteo; Giarda, Mariangela; Valente, Guido; Benech, Arnaldo

2005-11-01

Hemangiopericytoma is a rare vascular tumor first described by Stout and Murray in 1942 and characterized by a proliferation of Zimmermann's pericytes, smooth muscle cells arranged around blood vessels. This tumor presents as a slowly enlarging painless mass. Diagnosis with certainty is often a difficult one because of the close likeness with other spindle cell tumors; it requires the help of immunohistochemical techniques and sometimes ultrastructural techniques. Only 15% of hemangiopericytomas are localized in the cervicofacial region; in particular, occurrence in the infratemporal fossa is an exceptional occurrence. In this article, we report an unusual case of recidivate hemangiopericytoma of the infratemporal fossa that has progressively assumed features of malignancy over 30 years. The hemangiopericytoma relapse potentiality is elevated, even when the histologic characteristics of the tumor indicate a low aggressivity, and therefore every hemangiopericytoma must be considered to have malignant potential. In conclusion, the unpredictable behavior of hemangiopericytoma requires a radical primary treatment to avoid the risk of relapses that always are frequent and aggressive.

Mortality Rates After Emergent Posterior Fossa Decompression for Ischemic or Hemorrhagic Stroke in Older Patients.

PubMed

Puffer, Ross C; Graffeo, Christopher; Rabinstein, Alejandro; Van Gompel, Jamie J

2016-08-01

Cerebellar stroke causes major morbidity in the aging population. Guidelines from the American Stroke Association recommend emergent decompression in patients who have brainstem compression, hydrocephalus, or clinical deterioration. The objective of this study was to determine 30-day and 1-year mortality rates in patients >60 years old undergoing emergent posterior fossa decompression. Surgical records identified all patients >60 years old who underwent emergent posterior fossa decompression. Mortality rates were calculated at 30 days and 1 year postoperatively, and these rates were compared with patient and procedure characteristics. During 2000-2014, 34 emergent posterior fossa decompressions were performed in patients >60 years old. Mortality rates at 30 days were 0%, 33%, and 25% for age deciles 60-69 years, 70-79 years, and ≥80 years. Increasing age (alive at 30 days 75.2 years ± 1.7 vs. deceased 81.1 years ± 1.7, P = 0.01) and smaller craniectomy dimensions were associated with 30-day mortality. Mortality rates at 1 year were 0%, 50%, and 67% for age deciles 60-69 years, 70-79 years, and ≥80 years. Increasing age was significantly associated with mortality at 1 year (alive at 1 year 72.3 years ± 2.0 vs. deceased 81.1 years ± 1.2, P < 0.01). Type of pathology, side of pathology, volume of bleed/infarct, and placement of an external ventricular drain were not associated with mortality. Age was independent of admission Glasgow Coma Scale score as a predictor of mortality at 30 days, 90 days, and 1 year postoperatively. Increasing age and smaller craniectomy size were significantly associated with mortality in patients undergoing emergent posterior fossa decompression. Among patients ≥80 years old, one-quarter were dead within 1 month of the operation, and more than two-thirds were dead within 1 year. Copyright © 2016 Elsevier Inc. All rights reserved.

Systematic review and meta-analysis of isolated posterior fossa malformations on prenatal imaging (part 2): neurodevelopmental outcome.

PubMed

D'Antonio, F; Khalil, A; Garel, C; Pilu, G; Rizzo, G; Lerman-Sagie, T; Bhide, A; Thilaganathan, B; Manzoli, L; Papageorghiou, A T

2016-07-01

Diagnosis of isolated posterior fossa anomalies in children is biased by the fact that only those that are symptomatic are brought to the attention of the appropriate clinical personnel, and the reported rate is often affected by the adoption of different nomenclature, diagnostic criteria, outcome measures, duration of follow-up and neurodevelopmental tools. The aim of this systematic review was to explore the neurodevelopmental outcome of fetuses with a prenatal diagnosis of isolated posterior fossa anomalies. MEDLINE and EMBASE were searched electronically, utilizing combinations of the relevant medical subject heading terms for 'posterior fossa' and 'outcome'. Studies assessing the neurodevelopmental outcome in children with a prenatal diagnosis of isolated posterior fossa malformations were considered eligible. The posterior fossa anomalies analyzed included Dandy-Walker malformation (DWM), mega cisterna magna (MCM), Blake's pouch cyst (BPC) and vermian hypoplasia (VH). Two authors reviewed all abstracts independently. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies. Meta-analyses of proportions were used to combine data, and between-study heterogeneity was explored using the I(2) statistic. A total of 1640 articles were identified; 95 were assessed for eligibility and a total of 16 studies were included in the systematic review. The overall rate of abnormal neurodevelopmental outcome in children with a prenatal diagnosis of DWM was 58.2% (95% CI, 21.8-90.0%) and varied from 0-100%. In those with a prenatal diagnosis of MCM, the rate of abnormal neurodevelopmental outcome was 13.8% (95% CI, 7.3-21.9%), with a range of 0-50%. There was no significant association between BPC and the occurrence of abnormal neurodevelopmental delay, with a rate of 4.7% (95% CI, 0.7-12.1%) and range of 0-5%. Although affected by the very small number of studies, there was a non-significant occurrence of abnormal

Flow Patterns of Lobate Debris Aprons and Lineated Valley Fill North of Ismeniae Fossae, Mars

NASA Astrophysics Data System (ADS)

Baker, D. M.; Head, J. W.; Marchant, D. R.

2009-03-01

Flow patterns are mapped within lobate debris aprons and lineated valley fill north of Ismeniae Fossae, Mars. Flowlines are sourced in plateau alcoves and form large, well-integrated systems, consistent with a debris-covered glacier interpretation.

[Efficacies of arthroscopic debridement and olecranon fossa plasty in the treatment of osteoarthritis and posterior elbow impingement].

PubMed

Liu, Yu-jie; Wang, Jun-liang; Li, Hai-feng; Qi, Wei; Wang, Ning

2012-07-17

To evaluate the efficacies of arthroscopic debridement and removal of osteophyma for olecroanon and olecranon fossa plasty for posterior impingement of elbow joint. Between 1999 and 2008, a total of 21 cases were diagnosed with osteoarthritis and posterior elbow impingement. There were 15 males and 6 females. And there were 16 right and 15 left cases. They included volleyball players (n = 7), tennis players (n = 7), golf enthusiasts (n = 4) and fencers (n = 3). The average duration of onset-operation was 3.5 years (range: 2.5 - 8). Arthroscopic exploration revealed synovial hyperplasia hypertrophy, cartilage degeneration and olecranon fossa hyperplasia with deformed olecranon fossa. Debridement and plasty were performed. Loose bodies were removed from elbow joint in 6 patients. Partial resection of posterior olecranon tip was performed and osteophytes or fibrous tissue removed in this area. Dynamic observation showed no posterior elbow impingement. Postoperative follow-up was conducted in 19 cases and 2 cases became lost to follow-up. The average follow-up period was 25.3 months (range: 18 - 42). All patients were evaluated preoperatively and postoperatively with the Hospital for Special Surgery Elbow Assessment Scale. The outcomes were excellent (n = 12), good (n = 7) and fair (n = 2). Postoperative patients elbow swelling and pain relieve, sports and life function returns to normal, elbow flexion and rotating mobility obviously improved. With the elbow radiological films to measure the range of motion, the average range of motion was 90.5° preoperatively and improved to 130° postoperatively. There was significant improvement in all cases. Posterior elbow impingement is caused by hyperextension trauma and elbow overuse during specific sporting activities. Arthroscopic debridement and olecroanon or olecranon fossa plasty demonstrates excellent results for posterior impingement of elbow joint.

Transzygomatic approach with intraoperative neuromonitoring for resection of middle cranial fossa tumors.

PubMed

Son, Byung Chul; Lee, Sang Won; Kim, Sup; Hong, Jae Taek; Sung, Jae Hoon; Yang, Seung-Ho

2012-02-01

The authors reviewed the surgical experience and operative technique in a series of 11 patients with middle fossa tumors who underwent surgery using the transzygomatic approach and intraoperative neuromonitoring (IOM) at a single institution. This approach was applied to trigeminal schwannomas (n = 3), cavernous angiomas (n = 3), sphenoid wing meningiomas (n = 3), a petroclival meningioma (n = 1), and a hemangiopericytoma (n = 1). An osteotomy of the zygoma, a low-positioned frontotemporal craniotomy, removal of the remaining squamous temporal bone, and extradural drilling of the sphenoid wing made a flat trajectory to the skull base. Total resection was achieved in 9 of 11 patients. Significant motor pathway damage can be avoided using a change in motor-evoked potentials as an early warning sign. Four patients experienced cranial nerve palsies postoperatively, even though free-running electromyography of cranial nerves showed normal responses during the surgical procedure. A simple transzygomatic approach provides a wide surgical corridor for accessing the cavernous sinus, petrous apex, and subtemporal regions. Knowledge of the middle fossa structures is essential for anatomic orientation and avoiding injuries to neurovascular structures, although a neuronavigation system and IOM helps orient neurosurgeons.

A novel method for stereotactic, endoscope-assisted transtentorial placement of a shunt catheter into symptomatic posterior fossa cysts.

PubMed

Turner, Michael S; Nguyen, Ha Son; Payner, Troy D; Cohen-Gadol, Aaron A

2011-07-01

Posterior fossa cysts are usually divided into Dandy-Walker malformations, arachnoid cysts, and isolated and/or trapped fourth ventricles. Shunt placement is a mainstay treatment for decompression of these fluid collections when their expansion becomes symptomatic. Although several techniques to drain symptomatic posterior fossa cysts have been described, each method carries its own advantages and disadvantages. This article describes an alternative technique. In 10 patients, the authors used an alternative technique involving stereotactic and endoscopic methods to place a catheter in symptomatic posterior fossa cysts across the tentorium. Discussion of these cases is included, along with a review of various approaches to shunt placement in this region and recommendations regarding the proposed technique. No patient suffered intracranial hemorrhage related to the procedure and catheter implantation. All 3 patients who underwent placement of a new transtentorial cystoperitoneal shunt and a new ventriculoperitoneal shunt did not suffer any postoperative complication; a decrease in the size of their posterior fossa cysts was evident on CT scans obtained during the 1st postoperative day. Follow-up CT scans demonstrated either stable findings or further interval decrease in the size of their cysts. In 1 patient, the postoperative head CT demonstrated that the transtentorial catheter terminated posterior to the right parietal occipital region without entering the retrocerebellar cyst. This patient underwent a repeat operation for proximal shunt revision, resulting in an acceptable catheter implantation. The patient in Case 8 suffered from a shunt infection and subsequently underwent hardware removal and aqueductoplasty with stent placement. The patient in Case 9 demonstrated a slight increase in fourth ventricle size and was returned to the operating room. Exploration revealed a kink in the tubing connecting the distal limb of the Y connector to the valve. The Y

Factors associated with spinal fusion after posterior fossa decompression in pediatric patients with Chiari I malformation and scoliosis.

PubMed

Mackel, Charles E; Cahill, Patrick J; Roguski, Marie; Samdani, Amer F; Sugrue, Patrick A; Kawakami, Noriaki; Sturm, Peter F; Pahys, Joshua M; Betz, Randal R; El-Hawary, Ron; Hwang, Steven W

2016-12-01

OBJECTIVE The authors performed a study to identify clinical characteristics of pediatric patients diagnosed with Chiari I malformation and scoliosis associated with a need for spinal fusion after posterior fossa decompression when managing the scoliotic curve. METHODS The authors conducted a multicenter retrospective review of 44 patients, aged 18 years or younger, diagnosed with Chiari I malformation and scoliosis who underwent posterior fossa decompression from 2000 to 2010. The outcome of interest was the need for spinal fusion after decompression. RESULTS Overall, 18 patients (40%) underwent posterior fossa decompression alone, and 26 patients (60%) required a spinal fusion after the decompression. The mean Cobb angle at presentation and the proportion of patients with curves > 35° differed between the decompression-only and fusion cohorts (30.7° ± 11.8° vs 52.1° ± 26.3°, p = 0.002; 5 of 18 vs 17 of 26, p = 0.031). An odds ratio of 1.0625 favoring a need for fusion was established for each 1° of increase in Cobb angle (p = 0.012, OR 1.0625, 95% CI 1.0135-1.1138). Among the 14 patients older than 10 years of age with a primary Cobb angle exceeding 35°, 13 (93%) ultimately required fusion. Patients with at least 1 year of follow-up whose curves progressed more 10° after decompression were younger than those without curve progression (6.1 ± 3.0 years vs 13.7 ± 3.2 years, p = 0.001, Mann-Whitney U-test). Left apical thoracic curves constituted a higher proportion of curves in the decompression-only group (8 of 16 vs 1 of 21, p = 0.002). CONCLUSIONS The need for fusion after posterior fossa decompression reflected the curve severity at clinical presentation. Patients presenting with curves measuring > 35°, as well as those greater than 10 years of age, may be at greater risk for requiring fusion after posterior fossa decompression, while patients less than 10 years of age may require routine monitoring for curve progression. Left apical thoracic curves

[Management of arachnoid cysts of the middle cranial fossa accompanied by subdural effusions].

PubMed

Abderrahmen, K; Saadaoui, K; Bouhoula, A; Boubaker, A; Jemel, H

2012-10-01

Subdural effusions are uncommon but known complications of arachnoid cysts of the middle cranial fossa. They mainly occur after minor head traumas in young patients. Here, we report eight cases of arachnoid cyst of the middle cranial fossa associated with subdural hematoma in five cases and hygroma in three cases. Major symptoms are signs of raised intracranial pressure. CT scan and MRI showed the cyst and the subdural effusion. An excellent therapeutic result was achieved with evacuation of the subdural fluid via burr holes in the five cases of subdural hematoma while in the two cases of hygroma a subduro-peritoneal shunt was necessary. In the last case, a temporal craniotomy was performed with evacuation of the hygroma and fenestration of the cyst. We suggest treating only the complicating event in the case of a subdural hematoma via burr holes evacuation. Whereas, in the case of hygroma we think that craniotomy with fenestration of the cyst or the use of a subdural shunt are more often needed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Branchial sinus of the piriform fossa: reappraisal of third and fourth branchial anomalies.

PubMed

James, Adrian; Stewart, Craig; Warrick, Paul; Tzifa, Constance; Forte, Vito

2007-11-01

The objective of this study was to review clinical and embryologic aspects of third and fourth branchial anomalies. Retrospective study. We reviewed the institutional and departmental databases at our institution to identify all cases of third and fourth branchial anomalies encountered from 1992 to 2006. All patient records were examined with respect to demographics, clinical history, and radiologic and pathologic reports. We identified 17 cases of third and fourth branchial anomalies, the largest series of its kind reported to date. The lesions were predominantly left sided, all presenting with neck infection. Fistula formation was iatrogenic, secondary to incision and drainage. Preoperative direct laryngoscopy always revealed a pit within the apex of the piriform fossa. Surgical excision involved ipsilateral thyroidectomy as the lesion passed through the thyroid gland. No lesions following the classical course of a either a third or fourth branchial anomaly were identified. The clinical presentation of branchial sinuses arising from the piriform fossa is more in keeping with derivation from the thymopharyngeal duct (of the third pouch) than the hypothetical course of third and fourth branchial fistulae.

Therapeutic Impact of Cytoreductive Surgery and Irradiation of Posterior Fossa Ependymoma in the Molecular Era: A Retrospective Multicohort Analysis

PubMed Central

Ramaswamy, Vijay; Hielscher, Thomas; Mack, Stephen C.; Lassaletta, Alvaro; Lin, Tong; Pajtler, Kristian W.; Jones, David T.W.; Luu, Betty; Cavalli, Florence M.G.; Aldape, Kenneth; Remke, Marc; Mynarek, Martin; Rutkowski, Stefan; Gururangan, Sridharan; McLendon, Roger E.; Lipp, Eric S.; Dunham, Christopher; Hukin, Juliette; Eisenstat, David D.; Fulton, Dorcas; van Landeghem, Frank K.H.; Santi, Mariarita; van Veelen, Marie-Lise C.; Van Meir, Erwin G.; Osuka, Satoru; Fan, Xing; Muraszko, Karin M.; Tirapelli, Daniela P.C.; Oba-Shinjo, Sueli M.; Marie, Suely K.N.; Carlotti, Carlos G.; Lee, Ji Yeoun; Rao, Amulya A. Nageswara; Giannini, Caterina; Faria, Claudia C.; Nunes, Sofia; Mora, Jaume; Hamilton, Ronald L.; Hauser, Peter; Jabado, Nada; Petrecca, Kevin; Jung, Shin; Massimi, Luca; Zollo, Massimo; Cinalli, Giuseppe; Bognár, László; Klekner, Almos; Hortobágyi, Tibor; Leary, Sarah; Ermoian, Ralph P.; Olson, James M.; Leonard, Jeffrey R.; Gardner, Corrine; Grajkowska, Wieslawa A.; Chambless, Lola B.; Cain, Jason; Eberhart, Charles G.; Ahsan, Sama; Massimino, Maura; Giangaspero, Felice; Buttarelli, Francesca R.; Packer, Roger J.; Emery, Lyndsey; Yong, William H.; Soto, Horacio; Liau, Linda M.; Everson, Richard; Grossbach, Andrew; Shalaby, Tarek; Grotzer, Michael; Karajannis, Matthias A.; Zagzag, David; Wheeler, Helen; von Hoff, Katja; Alonso, Marta M.; Tuñon, Teresa; Schüller, Ulrich; Zitterbart, Karel; Sterba, Jaroslav; Chan, Jennifer A.; Guzman, Miguel; Elbabaa, Samer K.; Colman, Howard; Dhall, Girish; Fisher, Paul G.; Fouladi, Maryam; Gajjar, Amar; Goldman, Stewart; Hwang, Eugene; Kool, Marcel; Ladha, Harshad; Vera-Bolanos, Elizabeth; Wani, Khalida; Lieberman, Frank; Mikkelsen, Tom; Omuro, Antonio M.; Pollack, Ian F.; Prados, Michael; Robins, H. Ian; Soffietti, Riccardo; Wu, Jing; Metellus, Phillipe; Tabori, Uri; Bartels, Ute; Bouffet, Eric; Hawkins, Cynthia E.; Rutka, James T.; Dirks, Peter; Pfister, Stefan M.; Merchant, Thomas E.; Gilbert, Mark R.; Armstrong, Terri S.; Korshunov, Andrey; Ellison, David W.

2016-01-01

Purpose Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known. Methods Four independent nonoverlapping retrospective cohorts of posterior fossa ependymomas (n = 820) were profiled using genome-wide methylation arrays. Risk stratification models were designed based on known clinical and newly described molecular biomarkers identified by multivariable Cox proportional hazards analyses. Results Molecular subgroup is a powerful independent predictor of outcome even when accounting for age or treatment regimen. Incompletely resected EPN_PFA ependymomas have a dismal prognosis, with a 5-year progression-free survival ranging from 26.1% to 56.8% across all four cohorts. Although first-line (adjuvant) radiation is clearly beneficial for completely resected EPN_PFA, a substantial proportion of patients with EPN_PFB can be cured with surgery alone, and patients with relapsed EPN_PFB can often be treated successfully with delayed external-beam irradiation. Conclusion The most impactful biomarker for posterior fossa ependymoma is molecular subgroup affiliation, independent of other demographic or treatment variables. However, both EPN_PFA and EPN_PFB still benefit from increased extent of resection, with the survival rates being particularly poor for subtotally resected EPN_PFA, even with adjuvant radiation therapy. Patients with EPN_PFB who undergo gross total resection are at lower risk for relapse and should be considered for inclusion in a randomized clinical trial of observation alone with radiation reserved for those who experience recurrence. PMID:27269943

Analysis of the Volumes of the Posterior Cranial Fossa, Cerebellum, and Herniated Tonsils Using the Stereological Methods in Patients with Chiari Type I Malformation

PubMed Central

Vurdem, Ümit Erkan; Acer, Niyazi; Ertekin, Tolga; Savranlar, Ahmet; İnci, Mehmet Fatih

2012-01-01

Objective. The aim of this study was to determine the posterior cranial fossa volume, cerebellar volume, and herniated tonsillar volume in patients with chiari type I malformation and control subjects using stereological methods. Material and Methods. These volumes were estimated retrospectively using the Cavalieri principle as a point-counting technique. We used magnetic resonance images taken from 25 control subjects and 30 patients with chiari type I malformation. Results. The posterior cranial fossa volume in patients with chiari type I malformation was significantly smaller than the volume in the control subjects (P < 0.05). In the chiari type I malformation group, the cerebellar volume was smaller than the control group, but this difference was not statistically significant (P > 0.05). In the chiari type I malformation group, the ratio of cerebellar volume to posterior cranial fossa volume was higher than in the control group. We also found a positive correlation between the posterior cranial fossa volume and cerebellar volume for each of the groups (r = 0.865, P < 0.001). The mean (±SD) herniated tonsillar volume and length were 0.89 ± 0.50 cm3 and 9.63 ± 3.37 mm in the chiari type I malformation group, respectively. Conclusion. This study has shown that posterior cranial fossa and cerebellum volumes can be measured by stereological methods, and the ratio of these measurements can contribute to the evaluation of chiari type I malformation cases. PMID:22629166

Avian Cerebellar Floccular Fossa Size Is Not a Proxy for Flying Ability in Birds

PubMed Central

Walsh, Stig A.; Iwaniuk, Andrew N.; Knoll, Monja A.; Bourdon, Estelle; Barrett, Paul M.; Milner, Angela C.; Nudds, Robert L.; Abel, Richard L.; Sterpaio, Patricia Dello

2013-01-01

Extinct animal behavior has often been inferred from qualitative assessments of relative brain region size in fossil endocranial casts. For instance, flight capability in pterosaurs and early birds has been inferred from the relative size of the cerebellar flocculus, which in life protrudes from the lateral surface of the cerebellum. A primary role of the flocculus is to integrate sensory information about head rotation and translation to stabilize visual gaze via the vestibulo-occular reflex (VOR). Because gaze stabilization is a critical aspect of flight, some authors have suggested that the flocculus is enlarged in flying species. Whether this can be further extended to a floccular expansion in highly maneuverable flying species or floccular reduction in flightless species is unknown. Here, we used micro computed-tomography to reconstruct “virtual” endocranial casts of 60 extant bird species, to extract the same level of anatomical information offered by fossils. Volumes of the floccular fossa and entire brain cavity were measured and these values correlated with four indices of flying behavior. Although a weak positive relationship was found between floccular fossa size and brachial index, no significant relationship was found between floccular fossa size and any other flight mode classification. These findings could be the result of the bony endocranium inaccurately reflecting the size of the neural flocculus, but might also reflect the importance of the flocculus for all modes of locomotion in birds. We therefore conclude that the relative size of the flocculus of endocranial casts is an unreliable predictor of locomotor behavior in extinct birds, and probably also pterosaurs and non-avian dinosaurs. PMID:23825638

A Cognitive and Affective Pattern in Posterior Fossa Strokes in Children: A Case Series

ERIC Educational Resources Information Center

Kossorotoff, Manoelle; Gonin-Flambois, Coralie; Gitiaux, Cyril; Quijano, Susana; Boddaert, Nathalie; Bahi-Buisson, Nadia; Barnerias, Christine; Dulac, Olivier; Brunelle, Francis; Desguerre, Isabelle

2010-01-01

Aim: Posterior fossa strokes account for about 10% of ischaemic strokes in children. Although motor and dysautonomic symptoms are common, to our knowledge cognitive and affective deficits have not been described in the paediatric literature. Our aim, therefore, was to describe these symptoms and deficits. Method: In a retrospective study, we…

[A rare tumor of the infratemporal fossa].

PubMed

Bourhaleb, Z; Chekrine, T; Bouamama, I; Bouchbika, Z; Benchakroun, N; Jouhadi, H; Tawfiq, N; Sahraoui, S; Benider, A

2010-06-01

Giant cell tumors of bone (GCT) are usually benign and relatively rare. They have an aggressive behavior and an unpredictable prognosis. They occur mainly in the young adult, with a preferential localization in long bones. We report a giant cell infratemporal fossa tumor. A 55-year-old female patient consulted for swelling in the right cheek. Surgical excision was incomplete because of the subtemporal tumor localization. Histological assessment proved a GCT. Forty-five grays postoperative external radiotherapy was applied to the surgical site. The patient had local control at the 12-month follow-up. GCTs are seldom observed in the facial skeleton (2%). The recommended treatment is surgery. Radiotherapy can be indicated in case of incomplete or impossible surgical excision, or when surgery would be responsible for a major functional deficit. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Articular disc and eminence modeling after experimental relocation of the glenoid fossa in growing rabbits.

PubMed

Pirttiniemi, P; Kantomaa, T; Tuominen, M; Salo, L

1994-02-01

The articular surface of the glenoid fossa shows some analogy to the mandibular condyle, since the surface is covered by secondary cartilage, which makes the process more elastic than purely bony structures. The condylar cartilage has been shown to be responsive to alterations in load pressures, and this secondary type of cartilage is also able to increase its proliferative activity to a limited extent when the load pressure is altered. The aim here was to measure changes in proliferative activity and type II collagen secretion in the articular surface of the glenoid fossa after steady experimental posterior relocation of the fossa in the rabbit without actively interfering with normal masticatory action. The shape of the articular disc and interrelations of the joint components were measured macroscopically. Twenty-four five-day-old rabbits underwent gluing of the interparietal, temporoparietal, and lambdoidal sutures. Three experimental and 3 control rabbits were injected with tritiated thymidine at 10, 15, 20, and 30 days and were killed after 2 h for histological, autoradiographic, and immunohistochemical examination. The total number of labeled cells in the proliferative layer near the articular eminence was higher in the experimental group, the difference being greatest in the 15- and 20-day-old rabbits. Immunohistochemical examination revealed less staining for type II collagen on the postero-inferior side of the eminence in the experimental group. The articular disc was flattened in the experimental group, and the elastic tissue bundle connecting the articular eminence and the anterior border of the disc was significantly narrower and longer.

Mineral Spectra from Nili Fossae, Mars

NASA Technical Reports Server (NTRS)

2008-01-01

Spectra collected by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) indicate the presence of three distinct minerals. The graphed information comes from an observation of terrain in the Nili Fossae area of northern Mars. CRISM is one of six science instruments on NASA's Mars Reconnaissance Orbiter.

Iron-magnesium smectite clay is formed through alteration of rocks by liquid water and is characterized by distinctive absorptions at 1.4, 1.9, and 2.3 micrometers due to water (H2O) and OH in the atomic structure of the mineral. Olivine is an iron magnesium silicate and primary igneous mineral, and water is not in its structure. Its spectrum is characterized by a strong and broad absorption at 1.0 micrometer due to ferrous iron (Fe2+). Carbonate is an alteration mineral identified by the distinctive paired absorptions at 2.3 and 2.5 micrometers. The precise band positions at 2.31 and 2.51 micrometers identify the carbonate at this location as magnesium carbonate. The broad 1.0 micrometer band indicates some small amount of ferrous iron is also present and the feature at 1.9 micrometers indicates the presence of water. CRISM researchers believe the magnesium carbonate found in the Nili Fossae region formed from alteration of olivine by water.

The data come from a CRISM image catalogued as FRT00003E12. The spectra shown here are five-pixel-by-five-pixel averages of CRISM L-detector spectra taken from three different areas within the image that have then been ratioed to a five-pixel-by-five-pixel common denominator spectrum taken from a spectrally unremarkable area with no distinctive mineralogic signatures. This technique highlights the spectral contrasts between regions due to their unique mineralogy. The spectral wavelengths near 2.0 micrometers are affected by atmospheric absorptions and have been removed for clarity.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars

[Comparison of posterior fossa decompression with and without duraplasty for surgical management for adult Chiari malformation type Ⅰ].

PubMed

Li, H Y; Li, Y M; Chen, H; Li, Y; Shi, X W

2017-07-04

Objective: To evaluate and compare the efficacy between posterior fossa decompression without duraplasty (PFD) and posterior fossa decompression with duraplasty (PFDD) in the surgical management for adult Chiari Ⅰ malformation. Methods: Fifty-seven patients suffered from Chiari malformation type Ⅰ were treated in Department of Neurosurgery, Henan Provincial People's Hospital from August 2008 to October 2013. Twenty-three patients received posterior fossa decompression without duraplasty and the other 34 patients received posterior fossa decompression with duraplasty. The clinical results were retrospectively analyzed to compare the efficacy of two different surgical approaches. Results: There was no death or severe neurological dysfunction case in 57 patients of the two groups. Patients undergoing PFD had shorter length of hospital stay[(13.7±3.5) d vs (16.2±4.1) d, P <0.05]and surgical time[(98.7±22.1) min vs (132.3±39.6)min, P <0.05]. Cerebrospinal fluid-related complications and intracranial infection were more common in patients undergoing PFDD[(0/23, 0) vs (8/34, 23.5%), P <0.05]. Clinical improvement was comparable in two groups[(15/23, 65.2%) vs (26/34, 76.5%), P >0.05]at the one-year follow-up. The rate of syrinx regression in patients with Syringomyelia was higher in patients undergoing PFDD[(3/12, 25%) vs (17/22, 77.3%), P <0.05]. Conclusion: For adult patients with Chiari malformation type Ⅰ, PFD has the advantages of simple manipulation, short length of hospital stay and low incidence of cerebrospinal fluid-related complications and intracranial infection, compared with PFDD. It is comparable to PFDD in clinical improvement, but the effect of PFD is not as good as that of PFDD in the aspect of syrinx regression.

Hephaestus Fossae

NASA Technical Reports Server (NTRS)

2002-01-01

[figure removed for brevity, see original site] (Released 3 July 2002) Off the western flank of Elysium are the Hephaestus Fossae, including linear arrangements of small, round pits. These features are commonly called 'pit chains' and most likely represent the collapse of lava tubes. Lava tubes allow molten rock to move long distances underground. When the lava drains out it leaves unsupported tunnels, which can collapse and form pits. These particular pit chains are unusual because they change direction abruptly. In the lower portion of the image, pits have collapsed at the bends and allow us to observe the sharp, nearly right angle corners. These direction changes are most likely due to some sort of structural control during the emplacement of the lava tubes. There is an extraordinarily high concentration of small, degraded craters on the plains surface. The size range of these craters is fairly consistent and they all appear to be of similar age. It is unlikely that these were caused by primary impacts (impacts of meteors onto the surface) because both the size and timing distributions of primary impactors vary tremendously. However, the craters in the image could have been created from secondary impacts. Secondaries are impacts of material that is excavated during a large cratering event nearby or from the disintegration of a primary meteor in the atmosphere into many smaller parts that rain onto the surface. In contrast to these older, small craters, there is a relatively young crater in the center of the image. A hummocky ejecta blanket is visible around the crater and has covered some of the smaller craters on the plain around it. The edges of the crater are sharp, formed by rocky material in the crater rim. This material is visible as the layer of rough, grooved material at the top of the inside walls. Small dust avalanches have left dark streaks down the inside walls of the crater.

Therapeutic Impact of Cytoreductive Surgery and Irradiation of Posterior Fossa Ependymoma in the Molecular Era: A Retrospective Multicohort Analysis.

PubMed

Ramaswamy, Vijay; Hielscher, Thomas; Mack, Stephen C; Lassaletta, Alvaro; Lin, Tong; Pajtler, Kristian W; Jones, David T W; Luu, Betty; Cavalli, Florence M G; Aldape, Kenneth; Remke, Marc; Mynarek, Martin; Rutkowski, Stefan; Gururangan, Sridharan; McLendon, Roger E; Lipp, Eric S; Dunham, Christopher; Hukin, Juliette; Eisenstat, David D; Fulton, Dorcas; van Landeghem, Frank K H; Santi, Mariarita; van Veelen, Marie-Lise C; Van Meir, Erwin G; Osuka, Satoru; Fan, Xing; Muraszko, Karin M; Tirapelli, Daniela P C; Oba-Shinjo, Sueli M; Marie, Suely K N; Carlotti, Carlos G; Lee, Ji Yeoun; Rao, Amulya A Nageswara; Giannini, Caterina; Faria, Claudia C; Nunes, Sofia; Mora, Jaume; Hamilton, Ronald L; Hauser, Peter; Jabado, Nada; Petrecca, Kevin; Jung, Shin; Massimi, Luca; Zollo, Massimo; Cinalli, Giuseppe; Bognár, László; Klekner, Almos; Hortobágyi, Tibor; Leary, Sarah; Ermoian, Ralph P; Olson, James M; Leonard, Jeffrey R; Gardner, Corrine; Grajkowska, Wieslawa A; Chambless, Lola B; Cain, Jason; Eberhart, Charles G; Ahsan, Sama; Massimino, Maura; Giangaspero, Felice; Buttarelli, Francesca R; Packer, Roger J; Emery, Lyndsey; Yong, William H; Soto, Horacio; Liau, Linda M; Everson, Richard; Grossbach, Andrew; Shalaby, Tarek; Grotzer, Michael; Karajannis, Matthias A; Zagzag, David; Wheeler, Helen; von Hoff, Katja; Alonso, Marta M; Tuñon, Teresa; Schüller, Ulrich; Zitterbart, Karel; Sterba, Jaroslav; Chan, Jennifer A; Guzman, Miguel; Elbabaa, Samer K; Colman, Howard; Dhall, Girish; Fisher, Paul G; Fouladi, Maryam; Gajjar, Amar; Goldman, Stewart; Hwang, Eugene; Kool, Marcel; Ladha, Harshad; Vera-Bolanos, Elizabeth; Wani, Khalida; Lieberman, Frank; Mikkelsen, Tom; Omuro, Antonio M; Pollack, Ian F; Prados, Michael; Robins, H Ian; Soffietti, Riccardo; Wu, Jing; Metellus, Phillipe; Tabori, Uri; Bartels, Ute; Bouffet, Eric; Hawkins, Cynthia E; Rutka, James T; Dirks, Peter; Pfister, Stefan M; Merchant, Thomas E; Gilbert, Mark R; Armstrong, Terri S; Korshunov, Andrey; Ellison, David W; Taylor, Michael D

2016-07-20

Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known. Four independent nonoverlapping retrospective cohorts of posterior fossa ependymomas (n = 820) were profiled using genome-wide methylation arrays. Risk stratification models were designed based on known clinical and newly described molecular biomarkers identified by multivariable Cox proportional hazards analyses. Molecular subgroup is a powerful independent predictor of outcome even when accounting for age or treatment regimen. Incompletely resected EPN_PFA ependymomas have a dismal prognosis, with a 5-year progression-free survival ranging from 26.1% to 56.8% across all four cohorts. Although first-line (adjuvant) radiation is clearly beneficial for completely resected EPN_PFA, a substantial proportion of patients with EPN_PFB can be cured with surgery alone, and patients with relapsed EPN_PFB can often be treated successfully with delayed external-beam irradiation. The most impactful biomarker for posterior fossa ependymoma is molecular subgroup affiliation, independent of other demographic or treatment variables. However, both EPN_PFA and EPN_PFB still benefit from increased extent of resection, with the survival rates being particularly poor for subtotally resected EPN_PFA, even with adjuvant radiation therapy. Patients with EPN_PFB who undergo gross total resection are at lower risk for relapse and should be considered for inclusion in a randomized clinical trial of observation alone with radiation reserved for those who experience recurrence. © 2016 by American Society of Clinical Oncology.

Schwannoma-like tumor in the anterior cranial fossa immunonegative for Leu7 but immunopositive for Schwann/2E.

PubMed

Bohoun, Christian Aïssè; Terakawa, Yuzo; Goto, Takeo; Tanaka, Sayaka; Kuwae, Yuko; Ohsawa, Masahiko; Morisako, Hiroki; Nakajo, Kosuke; Sato, Hidetoshi; Ohata, Kenji; Yokoo, Hideaki

2017-06-01

Schwannoma arising from the olfactory system, often called olfactory groove schwannoma (OGS), is rare, as the olfactory bulb and tract, belonging to the central nervous system, should lack Schwann cells. Another rare entity called olfactory ensheathing cell tumor (OECT) has been reported, which mimics clinical and radiological characteristics of OGS. Here, we report two rare cases of schwannoma-like tumor in the anterior cranial fossa that showed negative staining for Leu7, but positive staining for Schwann/2E, and discuss their origin. Two cases of mass lesions in the anterior cranial fossa in a 26-year-old man and a 24-year-old woman were successfully removed. Morphological examination of these tumors was compatible with a diagnosis of schwannoma. Immunohistochemically, both cases were negative for Leu7, yielding a diagnosis of OECT, but were positive for the schwannoma-specific marker, Schwann/2E. Immunohistochemical staining results in our two cases question the current assumption that OGS and OECT can be distinguished only by Leu7 staining pattern. In conclusion, the origins of OGS and OECT remain to be determined, and further studies in larger numbers of cases are needed to characterize these rare tumors in the anterior cranial fossa. © 2016 Japanese Society of Neuropathology.

Rostral cranial fossa as a site for cerebrospinal fluid drainage - volumetric studies in dog breeds of different size and morphotype.

PubMed

Sokołowski, Wojciech; Czubaj, Norbert; Skibniewski, Michał; Barszcz, Karolina; Kupczyńska, Marta; Kinda, Wojciech; Kiełbowicz, Zdzisław

2018-05-18

Hydrocephalus is a multifactorial condition, whose aetiology is not fully understood. Congenital hydrocephalus frequently occurs in small and brachycephalic dog breeds. Although it is widely accepted that the cribriform plate located in the rostral cranial fossa (RCF) is a site of cerebrospinal fluid (CSF) drainage, the RCF has not been studied extensively. Literature reports indicate that a decreased caudal cranial fossa (CCF) volume in the course of the Chiari-like malformation may obstruct CSF circulation. We hypothesised that morphological diversity among different breeds in the volume of the RCF may affect CSF circulation. The aim of the study was to carry out a volumetric analysis of the RCF and the cranial cavity and to determine the ratio between them in dog breeds of different size and morphotype. We performed computed tomography (CT) morphometric analysis of the RCF compartment by obtaining volume measurements from the transverse and reformatted sagittal and dorsal planes. The rostral cranial fossa percentage - volume of the rostral cranial fossa/volume of cranial cavity × 100 (volRCF/volCC × 100) was lower in small and brachycephalic dog breeds than in the other dogs. A reduced RCF volume was detected in small and brachycephalic dog breeds, some of which are predisposed to congenital hydrocephalus. This may lead to overcrowding of brain parenchyma in the RCF and may impede CSF circulation. Our observations may be useful for future studies focusing on the causes and new therapies to treat conditions such as hydrocephalus and syringomyelia.

Combined Endoscopic Transorbital and Endonasal Repair of High Flow Orbital Apex/Middle Fossa Cerebrospinal Fluid Leak with a Nasoseptal Flap.

PubMed

Lucke-Wold, Brandon; Mendez, Gustavo; Cua, David; Akins, Paul; Gillham, Haley; Ciporen, Jeremy

2018-01-01

High flow orbital apex or middle fossa cerebrospinal fluid (CSF) leaks can be life threatening and complex to repair. These leaks associated with large dural defects are most commonly repaired with an open temporalis muscle patch or free flaps, but these flaps do not always stop the leak. A 65-year-old patient presented two years after orbital exenteration and radiation for squamous cell carcinoma. He developed multi-organism meningitis and pneumocephalus secondary to a large high-flow orbital apex/middle fossa CSF leak. To repair the leak, a combined endoscopic transorbital/endonasal approach with pedicled nasospetal flap and dermis fat graft was used. We describe the unique endoscopic technique that was used to treat the life threatening high flow orbital apex/middle fossa CSF leak. The technique allowed the use of the transposed pedicled flap, which is an alternative to the free flap in controlling CSF leak. Cisternogram post-operatively and clinical exam confirmed resolution of CSF leak. Although a critically ill patient at admission with a modified Rankin scale (MRS) of 5, he was discharged home on continued IV antibiotic therapy with a MRS of 3. Endoscopic evaluation at three months after treatment showed the effectiveness of the flap and he continued to improve clinically. This is the first case to describe a combined endoscopic transorbital and endonasal repair of high flow orbital apex/middle fossa CSF leak with a pedicled nasoseptal flap. These techniques can be utilized during initial reconstruction after orbital exenteration or as a salvage flap.

Posterior fossa anomalies diagnosed with fetal MRI: associated anomalies and neurodevelopmental outcomes.

PubMed

Patek, Kyla J; Kline-Fath, Beth M; Hopkin, Robert J; Pilipenko, Valentina V; Crombleholme, Timothy M; Spaeth, Christine G

2012-01-01

The purpose of this study was to describe the relationship between intracranial and extracranial anomalies and neurodevelopmental outcome for fetuses diagnosed with a posterior fossa anomaly (PFA) on fetal MRI. Cases of Dandy-Walker malformation, vermian hypogenesis/hypoplasia, and mega cisterna magna (MCM) were identified through the Fetal Care Center of Cincinnati between January 2004 and December 2010. Parental interview and retrospective chart review were used to assess neurodevelopmental outcome. Posterior fossa anomalies were identified in 59 fetuses; 9 with Dandy-Walker malformation, 36 with vermian hypogenesis/hypoplasia, and 14 with MCM. Cases with isolated PFAs (14/59) had better outcomes than those with additional anomalies (p = 0.00016), with isolated cases of MCM all being neurodevelopmentally normal. Cases with additional intracranial anomalies had a worse outcome than those without intracranial anomalies (p = 0.00017). The presence of extracranial anomalies increased the likelihood of having a poor outcome (p = 0.00014) as did the identification of an abnormal brainstem (p = 0.00018). Intracranial and extracranial anomalies were good predictors of neurodevelopmental outcome in this study. The prognosis was poor for individuals with an abnormal brainstem, whereas those with isolated MCM had normal neurodevelopmental outcome. © 2012 John Wiley & Sons, Ltd.

Behavioural abnormalities of the hyposulphataemic Nas1 knock-out mouse.

PubMed

Dawson, Paul Anthony; Steane, Sarah Elizabeth; Markovich, Daniel

2004-10-05

We recently generated a sodium sulphate cotransporter knock-out mouse (Nas1-/-) which has increased urinary sulphate excretion and hyposulphataemia. To examine the consequences of disturbed sulphate homeostasis in the modulation of mouse behavioural characteristics, Nas1-/- mice were compared with Nas1+/- and Nas1+/+ littermates in a series of behavioural tests. The Nas1-/- mice displayed significantly (P < 0.001) decreased marble burying behaviour (4.33 +/- 0.82 buried) when compared to Nas1+/+ (7.86 +/- 0.44) and Nas1+/- (8.40 +/- 0.37) animals, suggesting that Nas1-/- mice may have decreased object-induced anxiety. The Nas1-/- mice also displayed decreased locomotor activity by moving less distance (1.53 +/- 0.27 m, P < 0.05) in an open-field test when compared to Nas1+/+ (2.31 +/- 0.24 m) and Nas1+/- (2.15 +/- 0.19 m) mice. The three genotypes displayed similar spatiotemporal and ethological behaviours in the elevated-plus maze and open-field test, with the exception of a decreased defecation frequency by the Nas1-/- mice (40% reduction, P < 0.01). There were no significant differences between Nas1-/- and Nas1+/+ mice in a rotarod performance test of motor coordination and in the forced swim test assessing (anti-)depressant-like behaviours. This is the first study to demonstrate behavioural abnormalities in the hyposulphataemic Nas1-/- mice.

Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars

NASA Technical Reports Server (NTRS)

Bleamaster, Leslie F., III; Crown, David A.

2009-01-01

Geologic mapping studies at the 1:1M-scale are being used to assess geologic materials and processes that shape the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary may provide constraints on: 1) origin of the dichotomy boundary, 2) paleo-environments and climate conditions, and 3) various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The results of this work will include two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

ModFossa: A library for modeling ion channels using Python.

PubMed

Ferneyhough, Gareth B; Thibealut, Corey M; Dascalu, Sergiu M; Harris, Frederick C

2016-06-01

The creation and simulation of ion channel models using continuous-time Markov processes is a powerful and well-used tool in the field of electrophysiology and ion channel research. While several software packages exist for the purpose of ion channel modeling, most are GUI based, and none are available as a Python library. In an attempt to provide an easy-to-use, yet powerful Markov model-based ion channel simulator, we have developed ModFossa, a Python library supporting easy model creation and stimulus definition, complete with a fast numerical solver, and attractive vector graphics plotting.

A Prostate Fossa Contouring Instructional Module: Implementation and Evaluation.

PubMed

Gunther, Jillian R; Liauw, Stanley L; Choi, Seungtaek; Mohamed, Abdallah S R; Thaker, Nikhil G; Fuller, Clifton D; Stepaniak, Christopher J; Das, Prajnan; Golden, Daniel W

2016-07-01

Radiation oncology trainees frequently learn to contour through clinical experience and lectures. A hands-on contouring module was developed to teach delineation of the postoperative prostate clinical target volume (CTV) and improve contouring accuracy. Medical students independently contoured a prostate fossa CTV before and after receiving educational materials and live instruction detailing the RTOG approach to contouring this CTV. Metrics for volume overlap and surface distance (Dice similarity coefficient, Hausdorff distance (HD), and mean distance) determined discordance between student and consensus contours. An evaluation assessed perception of session efficacy (1 = "not at all" to 5 = "extremely"; reported as median[interquartile range]). Non-parametric statistical tests were used. Twenty-four students at two institutions completed the module, and 21 completed the evaluation (88% response). The content was rated as "quite" important (4[3.5-5]). The module improved comfort contouring a prostate fossa (pre 1[1-2] vs. post 4[3-4], p<.01), ability to find references (pre 2[1-3] vs. post 4[3.5-4], p<0.01), knowledge of CT prostate/pelvis anatomy (pre 2[1.5-3] vs. post 3[3-4], p<.01), and ability to use contouring software tools (pre 2[2-3.5] vs. post 3[3-4], p=.01). After intervention, mean DSC increased (0.29 to 0.68, p<0.01) and HD and mean distance both decreased, respectively (42.8 to 30.0, p<.01; 11.5 to 1.9, p<.01). A hands-on module to teach CTV delineation to medical students was developed and implemented. Student and expert contours exhibited near "excellent agreement" (as defined in the literature) after intervention. Additional modules to teach target delineation to all educational levels can be developed using this model. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Numerical Aerodynamic Simulation (NAS)

NASA Technical Reports Server (NTRS)

Peterson, V. L.; Ballhaus, W. F., Jr.; Bailey, F. R.

1983-01-01

The history of the Numerical Aerodynamic Simulation Program, which is designed to provide a leading-edge capability to computational aerodynamicists, is traced back to its origin in 1975. Factors motivating its development and examples of solutions to successively refined forms of the governing equations are presented. The NAS Processing System Network and each of its eight subsystems are described in terms of function and initial performance goals. A proposed usage allocation policy is discussed and some initial problems being readied for solution on the NAS system are identified.

NAS-current status and future plans

NASA Technical Reports Server (NTRS)

Bailey, F. R.

1987-01-01

The Numerical Aerodynamic Simulation (NAS) has met its first major milestone, the NAS Processing System Network (NPSN) Initial Operating Configuration (IOC). The program has met its goal of providing a national supercomputer facility capable of greatly enhancing the Nation's research and development efforts. Furthermore, the program is fulfilling its pathfinder role by defining and implementing a paradigm for supercomputing system environments. The IOC is only the begining and the NAS Program will aggressively continue to develop and implement emerging supercomputer, communications, storage, and software technologies to strengthen computations as a critical element in supporting the Nation's leadership role in aeronautics.

Medusae Fossae Formation

NASA Technical Reports Server (NTRS)

1998-01-01

An exotic terrain of wind-eroded ridges and residual smooth surfaces are seen in one of the highest resolution images ever taken of Mars from orbit. The Medusae Fossae formation is believed to be formed of the fragmental ejecta of huge explosive volcanic eruptions. When subjected to intense wind-blasting over hundreds of millions of years, this material erodes easily once the uppermost tougher crust is breached. In the Mars Orbiter Camera (MOC) image shown on the right, the crust, or cap rock, can be seen in the upper right part of the picture. The finely-spaced ridges are similar to features on Earth called yardangs, which are formed by intense winds plucking individual grains from, and by wind-driven sand blasting particles off, sedimentary deposits.

The MOC image was taken on October 30, 1997 at 11:05 AM PST, shortly after the Mars Global Surveyor spacecraft's 31st closest approach to Mars. The image covers an area 3.6 X 21.5 km (2.2 X 13.4 miles) at 3.6 m (12 feet) per picture element--craters only 11 m (36 feet, about the size of a swimming pool) across can be seen. The context image (left; the best Viking view of the area; VO 1 387S34) has a resolution of 240 m/pixel, or 67 times lower resolution than the MOC frame.

Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

Neglected foreign body infratemporal fossa, a typical presentation: a case report.

PubMed

Sajad, Mir; Kirmani, Masood A; Patigaroo, A R

2011-07-01

A 25 year old male presented to our ENT OPD with the history of hyperemic swelling left zygomatic area with a pointed pustule in the centre resembling a furuncle,which progressed into a discharging sinus, complicated by trismus. The patient had a past history of trauma in the vicinity of the left zygomatic area 4-months back with a pointed stick the tip of the stick which had got lodged in the wound at that time was removed. The diagnostic dilemma was solved as neglected foreign body infratemporal fossa.

Neogene volcanism associated with back-arc basin tectonics at the northern Fossa Magna, NE Japan

NASA Astrophysics Data System (ADS)

Okamura, S.; Inaba, M.; Shinjo, R.; Adachi, Y.

2016-12-01

New isotopic and trace element data presented here imply a temporal change in magma sources and thermal conditions beneath the northern Fossa Magna of NE Japan from the Miocene to the Pliocene. Rocks from more sediment melt-rich Early Miocene volcanoes have less radiogenic 176Hf/177Hf and 143Nd/144Nd, high Zr/Hf, and little or no Hf anomaly (Hf/Hf*; ˜1.0). The mantle wedge in the Early Miocene consisted of enriched mantle source. We propose that during the onset of subduction, influx of hot asthenospheric mantle provided sufficient heat to partially melt newly subducting sediment. Geochemical modeling results suggest breakdown of zircon in the slab surface sediments for the Early Miocene lavas in the northern Fossa Magna region. In the Middle Miocene, the injection of hot and depleted asthenospheric material replaced the mantle beneath the northern Fossa Magna region of NE Japan. This caused the isotopic signature of the rocks to change from enriched to depleted. The Middle Miocene lavas characterized by most radiogenic Hf and Nd isotope ratios, have high Zr/Hf, low Lu/Hf, and little or no Hf anomaly. An appropriate working petrogenetic model is that the Middle Miocene lavas were derived from asthenospheric depleted mantle, slightly ( < 1%) contaminated by slab melt accompanied by full dissolution of zircon. All the Late Miocene and Pliocene samples are characterized by distinctly more radiogenic 176Hf/177Hf and 143Nd/144Nd, and more negative Hf anomalies (greater Hf/Hf* variability; ˜0.3). The Pliocene samples are displaced toward lower Hf/Hf* and Zr/Hf, and higher Lu/Hf relative to the Middle Miocene samples, which requires mixing between depleted mantle and a partial melt of subducted metasediment saturated with trace quantity of zircon.

Postoperative intraspinal subdural collections after pediatric posterior fossa tumor resection: incidence, imaging, and clinical features.

PubMed

Harreld, J H; Mohammed, N; Goldsberry, G; Li, X; Li, Y; Boop, F; Patay, Z

2015-05-01

Postoperative intraspinal subdural collections in children after posterior fossa tumor resection may temporarily hinder metastasis detection by MR imaging or CSF analysis, potentially impacting therapy. We investigated the incidence, imaging and clinical features, predisposing factors, and time course of these collections after posterior fossa tumor resection. Retrospective review of postoperative spine MRI in 243 children (5.5 ± 4.6 years of age) from our clinical data base postresection of posterior fossa tumors from October 1994 to August 2010 yielded 37 (6.0 ± 4.8 years of age) subjects positive for postoperative intraspinal subdural collections. Their extent and signal properties were recorded for postoperative (37/37), preoperative (15/37), and follow-up spine (35/37) MRI. Risk factors were compared with age-matched internal controls (n = 37, 5.9 ± 4.5 years of age). Associations of histology, hydrocephalus and cerebellar tonsillar herniation, and postoperative intracranial subdural collections with postoperative intraspinal subdural collections were assessed by the Fisher exact test or χ(2) test. The association between preoperative tumor volume and postoperative intraspinal subdural collections was assessed by the Wilcoxon rank sum test. The overall incidence of postoperative intraspinal subdural collections was 37/243 (15.2%), greatest ≤7 days postoperatively (36%); 97% were seen 0-41 days postoperatively (12.9 ± 11.0 days). They were T2 hyperintense and isointense to CSF on T1WI, homogeneously enhanced, and resolved on follow-up MR imaging (35/35). None were symptomatic. They were associated with intracranial subdural collections (P = .0011) and preoperative tonsillar herniation (P = .0228). Postoperative intraspinal subdural collections are infrequent and clinically silent, resolve spontaneously, and have a distinctive appearance. Preoperative tonsillar herniation appears to be a predisposing factor. In this series, repeat MR imaging by 4 weeks

Middle cranial fossa approach to repair tegmen defects assisted by three-dimensionally printed temporal bone models.

PubMed

Ahmed, Sameer; VanKoevering, Kyle K; Kline, Stephanie; Green, Glenn E; Arts, H Alexander

2017-10-01

To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of patients undergoing repair of lateral skull base defects and spontaneous cerebrospinal fluid leaks with the middle cranial fossa approach. Case series. 3D-printed temporal bone models-based on patient-specific, high-resolution computed tomographic imaging-were constructed using inexpensive polymer materials. Preoperatively, the models demonstrated the extent of temporal lobe retraction necessary to visualize the proposed defects in the lateral skull base. Also preoperatively, Silastic sheeting was arranged across the modeled tegmen, marked, and cut to cover all of the proposed defect sites. The Silastic sheeting was then sterilized and subsequently served as a precise intraoperative template for a synthetic dural replacement graft. Of note, these grafts were customized without needing to retract the temporal lobe. Five patients underwent the middle cranial fossa approach assisted by 3D-printed temporal bone models to repair tegmen defects and spontaneous cerebrospinal fluid leaks. No complications were encountered. The prefabricated dural repair grafts were easily placed and fit precisely onto the middle fossa floor without any additional modifications. All defects were covered as predicted by the 3D temporal bone models. At their postoperative visits, all five patients maintained resolution of their spontaneous cerebrospinal fluid leaks. Inexpensive 3D-printed temporal bone models of tegmen defects can serve as beneficial adjuncts during lateral skull base repair. The models provide a panoramic preoperative view of all tegmen defects and allow for custom templating of dural grafts without temporal lobe retraction. 4 Laryngoscope, 127:2347-2351, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus

NASA Technical Reports Server (NTRS)

Zimbelman, J. R.

2010-01-01

This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geologic maps, generated under an earlier PGG mapping grant.

Condyle-fossa modifications and muscle interactions during herbst treatment, part 1. New technological methods.

PubMed

Voudouris, John C; Woodside, Donald G; Altuna, Gurkan; Kuftinec, Mladen M; Angelopoulos, Gerassimos; Bourque, Paul J

2003-06-01

Changes in the condyle, the glenoid fossa, and the muscles of mastication were investigated in subjects undergoing continuous orthopedic advancement of the mandible with a Herbst-block appliance. The total sample consisted of 56 subjects and included 15 nonhuman primates (in the middle mixed, early permanent, and permanent dentitions), 17 human Herbst patients in the early permanent dentition, and 24 human controls from the Burlington Growth Center. The 8 nonhuman primates in the middle mixed dentition were the focus of this study. Mandibular advancement was obtained progressively in 5 animals by adding stops to the telescopic arms of fixed functional Herbst appliances with occlusal coverage; activations of 5.0 mm, 7.0 mm, and 8.0 mm were achieved. Two primates served as controls, and the third was a sham control. Two experimental animals and the 2 controls also wore surgically implanted electromyographic electrodes in the superior and inferior heads of the lateral pterygoid muscles and in the superficial masseter and anterior digastric muscles. Changes in condylar growth direction and amount were assessed with the Björk method from measurements made on serial cephalometric tracings superimposed on metallic implants. Undecalcified sections, treated with intravenous tetracycline vital staining, were viewed with fluorescence microscopy to examine histologic changes in the condyle and the glenoid fossa. New bone formation in the fossa associated with continuous mandibular protrusion was quantified by using computerized histomorphometric analysis of decalcified histological sections and polarized light. The unique combination of permanently implanted electromyographic electrodes, tetracycline vital staining, and histomorphometry represents a significant technological advancement in methods and materials. Together, they demonstrated different muscle-bone interaction results for functional appliances than those reported in previous studies. In Part 1 of this study, we

Interdisciplinary Clinical Management of High Grade Arteriovenous Malformations and Ruptured Flow-Related Aneurysms in the Posterior Fossa

PubMed Central

Mpotsaris, A.; Loehr, C.; Harati, A.; Lohmann, F.; Puchner, M.; Weber, W.

2010-01-01

Summary Posterior fossa arteriovenous malformations are rare entities and treatment modalities technically challenging. In recent years new therapeutic options have emerged through microsurgical and endovascular means. Based on a series of six cases we describe combined interdisciplinary treatment strategies and report the outcome in a midterm follow-up interval of 12 months. Clinical case data were collected during acute phase and follow-up including standardized angiographic control intervals during follow-up and assessment of the outcome. Treatment options included endovascular techniques as well as microsurgical techniques. All reported cases had SAH based on ruptured flow-related aneurysms in posterior fossa AVM; three out of six had multiple aneurysms. In one case we observed a de novo formation of two flow-associated distal aneurysms in an interval of ten years. Two patients were treated only endovascularly, one patient only surgically and three patients with combined methods. Five out of six patients had a good outcome (GOS 4 or 5). One died in the acute phase. Infratentorial AVMs are rare but characterized by a high risk of rupture and SAH, especially in conjunction with flow related aneurysms, which are predictors of poor outcome. The anatomic conditions of the posterior fossa may lead quickly to life-threatening complications due to mass effects. The present study indicates that treatment strategies in the acute phase should focus on flow-related aneurysms, followed by an elective AVM embolization and ectomy whenever possible. An experienced interdisciplinary team and the combination of techniques contribute to a reduction of complications and to a better outcome. PMID:21162770

Endoscopic transnasal resection of anterior cranial fossa meningiomas.

PubMed

de Divitiis, Enrico; Esposito, Felice; Cappabianca, Paolo; Cavallo, Luigi M; de Divitiis, Oreste; Esposito, Isabella

2008-01-01

The extended transnasal approach, a recent surgical advancements for the ventral skull base, allows excellent midline access to and visibility of the anterior cranial fossa, which was previously thought to be approachable only via a transcranial route. The extended transnasal approach allows early decompression of the optic canals, obviates the need for brain retraction, and reduces neurovascular manipulation. Between 2004 and 2007, 11 consecutive patients underwent transnasal resection of anterior cranial fossa meningiomas--4 olfactory groove (OGM) and 7 tuberculum sellae (TSM) meningiomas. Age at surgery, sex, symptoms, and imaging studies were reviewed. Tumor size and tumor extension were estimated, and the anteroposterior, vertical, and horizontal diameters were measred on MR images. Medical records, surgical complications, and outcomes of the patients were collected. A gross-total removal of the lesion was achieved in 10 patients (91%), and in 1 patient with a TSM only a near-total (> 90%) resection was possible. Four patients with preoperative visual function defect had a complete recovery, whereas 3 patients experienced a transient worsening of vision, fully recovered within few days. In 3 patients (2 with TSMs and 1 with an OGM), a postoperative CSF leak occurred, requiring a endoscopic surgery for skull base defect repair. Another patient (a case involving a TSM) developed transient diabetes insipidus. The operative time ranged from 6 to 10 hours in the OGM group and from 4.5 to 9 hours in the TSM group. The mean duration of the hospital stay was 13.5 and 10 days in the OGM and TSM groups, respectively. Six patients (3 with OGMs and 3 with TSMs) required a blood transfusion. Surgery-related death occurred in 1 patient with TSM, in whom the tumor was successfully removed. The technique offers a minimally invasive route to the midline anterior skull base, allowing the surgeon to avoid using brain retraction and reducing manipulation of the large vessels and

[Ultrasound measurement of fetal posterior fossa at 11 to 13⁺⁶ gestational weeks for screening open spina bifida].

PubMed

Qin, Feng-Zhen; Li, Sheng-Li; Wen, Hua-Xuan; Ouyang, Yu-Rong; Zheng, Qiong; Bi, Jing-Ru

2014-06-01

To establish the normal reference ranges of transabdominal ultrasound measurements of the posterior fossa structure in fetuses at 11 to 13⁺⁶ gestational weeks and explore their clinical value in screening open spina bifida (OSB). Between January, 2013 and September, 541 randomly selected normal fetuses underwent nuchal translucency at the gestational age 11 to 13⁺⁶ weeks. The parameters of the posterior fossa were measured in mid-sagittal view of the fetal face and the axial view of the transverse cerebellum insonated through the anterior fontanel by transabdominal ultrasound to establish the normal reference ranges. The measurements were obtained from 3 fetuses with OSB for comparison with the reference ranges. In normal fetuses, the parameters of the posterior fossa measured in the two views showed no significant differences (P>0.05). Two high echogenic lines were observed in normal fetuses, as compared with one in fetuses with OSB representing the posterior border of the brain stem and the anterior border of the fourth ventricle. The line between the posterior border of the fourth ventricle and the anterior border of the cisterna magna was not displayed in fetuses with OSB. The anteroposterior diameters of the brain stem, the fourth ventricle, and cisterna magna all increased in positive correlation with the crown-lump length in normal fetuses. In the 3 OSB fetuses, the anteroposterior diameter of the brain stem exceeded the 95th percentile and the anteroposterior diameter of fourth ventrical-cisterner magena was below the 5th percentile of the reference range for CRL; the brain stem to fourth ventrical-cisterner magena anteroposterior diameter ratio was increased to above 1. The established normal reference ranges of the parameters of fetal posterior fossa may provide assistance in early OSB detection. The absence of the posterior border of the fourth ventricle and the anterior border of the cisterna magna and a brainstem to fourth ventrical

MOLA Topography of Small Volcanoes in Tempe Terra and Ceraunius Fossae, Mars: Implications for Eruptive Styles

NASA Technical Reports Server (NTRS)

Wong, M. P.; Sakimoto, S. E. H.; Garvin, J. B.

2001-01-01

We use Mars Orbiter Laser Altimeter (MOLA) data to measure small volcanoes in the Tempe Terra and Ceraunius Fossae regions of Mars. We find that previous geometry estimates based on imagery alone are inaccurate, but MOLA data support image-based interpretations of eruptive style. Additional information is contained in the original extended abstract.

The SMART-NAS Testbed

NASA Technical Reports Server (NTRS)

Aquilina, Rudolph A.

2015-01-01

The SMART-NAS Testbed for Safe Trajectory Based Operations Project will deliver an evaluation capability, critical to the ATM community, allowing full NextGen and beyond-NextGen concepts to be assessed and developed. To meet this objective a strong focus will be placed on concept integration and validation to enable a gate-to-gate trajectory-based system capability that satisfies a full vision for NextGen. The SMART-NAS for Safe TBO Project consists of six sub-projects. Three of the sub-projects are focused on exploring and developing technologies, concepts and models for evolving and transforming air traffic management operations in the ATM+2 time horizon, while the remaining three sub-projects are focused on developing the tools and capabilities needed for testing these advanced concepts. Function Allocation, Networked Air Traffic Management and Trajectory Based Operations are developing concepts and models. SMART-NAS Test-bed, System Assurance Technologies and Real-time Safety Modeling are developing the tools and capabilities to test these concepts. Simulation and modeling capabilities will include the ability to assess multiple operational scenarios of the national airspace system, accept data feeds, allowing shadowing of actual operations in either real-time, fast-time and/or hybrid modes of operations in distributed environments, and enable integrated examinations of concepts, algorithms, technologies, and NAS architectures. An important focus within this project is to enable the development of a real-time, system-wide safety assurance system. The basis of such a system is a continuum of information acquisition, analysis, and assessment that enables awareness and corrective action to detect and mitigate potential threats to continuous system-wide safety at all levels. This process, which currently can only be done post operations, will be driven towards "real-time" assessments in the 2035 time frame.

UAS Integration into the NAS Project

NASA Technical Reports Server (NTRS)

Bauer, Jeff

2010-01-01

The goal of the UAS Integration in the NAS Project is to contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS This goal will be accomplished through a two-phased approach of system-level integration of key concepts, technologies and/or procedures, and demonstrations of integrated capabilities in an operationally relevant environment. Technical objectives include: PHASE 1: a) Validating the key technical areas identified by this project. System-level analyses, a State of the Art Analysis (SOAA), and a ConOps will identify the challenges and barriers preventing routine UAS access to the NAS. b) Developing a national roadmap and gap analysis identifying specific deliverables in the area of operations, procedures, and technologies that will impact future policy decisions. PHASE 2: a) Provide regulators with a methodology for developing airworthiness requirements for UAS and data to support development of certifications standards and regulatory guidance. b) Provide systems-level integrated testing of concepts and/or capabilities that address barriers to routine access to the NAS. Through simulation and flight testing, address issues including separation assurance, communications requirements, and Pilot Aircraft Interfaces (PAIs) in operationally relevant environments

The Need for Vendor Source Code at NAS. Revised

NASA Technical Reports Server (NTRS)

Carter, Russell; Acheson, Steve; Blaylock, Bruce; Brock, David; Cardo, Nick; Ciotti, Bob; Poston, Alan; Wong, Parkson; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

The Numerical Aerodynamic Simulation (NAS) Facility has a long standing practice of maintaining buildable source code for installed hardware. There are two reasons for this: NAS's designated pathfinding role, and the need to maintain a smoothly running operational capacity given the widely diversified nature of the vendor installations. NAS has a need to maintain support capabilities when vendors are not able; diagnose and remedy hardware or software problems where applicable; and to support ongoing system software development activities whether or not the relevant vendors feel support is justified. This note provides an informal history of these activities at NAS, and brings together the general principles that drive the requirement that systems integrated into the NAS environment run binaries built from source code, onsite.

Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars: Introductory Report

NASA Technical Reports Server (NTRS)

Bleamaster, Leslie F., III; Crown, David A.

2008-01-01

Geologic mapping studies at the 1:1M-scale will be used to characterize geologic processes that have shaped the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary will provide the ability to: 1) further test original dichotomy formation hypotheses, 2) constrain ancient paleoenvironments and climate conditions, and 3) evaluate various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The result will be two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

Effect of sample freezing on the isolation of Mycoplasma spp. from the clitoral fossa of the mare.

PubMed Central

Bermudez, V; Miller, R B; Johnson, W; Rosendal, S; Ruhnke, L

1988-01-01

The growth of Mycoplasma equigenitalium and Mycoplasma subdolum from specimens collected from the clitoral fossa of each of four Standardbred mares was not diminished by freezing of the specimens in liquid nitrogen (-196 degrees C) for up to 30 days when compared to samples cultured immediately. PMID:3349394

Identification of hydrated silicate minerals on Mars using MRO-CRISM: Geologic context near Nili Fossae and implications for aqueous alteration

USGS Publications Warehouse

Ehlmann, B.L.; Mustard, J.F.; Swayze, G.A.; Clark, R.N.; Bishop, J.L.; Poulet, F.; Des Marais, D.J.; Roach, L.H.; Milliken, R.E.; Wray, J.J.; Barnouin-Jha, O.; Murchie, S.L.

2009-01-01

The Noachian terrain west of the Isidis basin hosts a diverse collection of alteration minerals in rocks comprising varied geomorphic units within a 100,000 km2 region in and near the Nili Fossae. Prior investigations in this region by the Observatoire pour l'Min??ralogie, l'Eau, les Glaces, et l'Activit?? (OMEGA) instrument on Mars Express revealed large exposures of both mafic minerals and iron magnesium phyllosilicates in stratigraphic context. Expanding on the discoveries of OMEGA, the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter (MRO) has found more spatially widespread and mineralogically diverse alteration minerals than previously realized, which represent multiple aqueous environments. Using CRISM near-infrared spectral data, we detail the basis for identification of iron and magnesium smectites (including both nontronite and more Mg-rich varieties), chlorite, prehnite, serpentine, kaolinite, potassium mica (illite or muscovite), hydrated (opaline) silica, the sodium zeolite analcime, and magnesium carbonate. The detection of serpentine and analcime on Mars is reported here for the first time. We detail the geomorphic context of these minerals using data from high-resolution imagers onboard MRO in conjunction with CRISM. We find that the distribution of alteration minerals is not homogeneous; rather, they occur in provinces with distinctive assemblages of alteration minerals. Key findings are (1) a distinctive stratigraphy, in and around the Nili Fossae, of kaolinite and magnesium carbonate in bedrock units always overlying Fe/Mg smectites and (2) evidence for mineral phases and assemblages indicative of low-grade metamorphic or hydrothermal aqueous alteration in cratered terrains. The alteration minerals around the Nili Fossae are more typical of those resulting from neutral to alkaline conditions rather than acidic conditions, which appear to have dominated much of Mars. Moreover, the mineralogic

Synovial sarcoma of the temporomandibular joint and infratemporal fossa.

PubMed

Nomura, Fuminori; Kishimoto, Seiji

2014-12-01

Synovial sarcoma in the head and neck region is rare, and is difficult to resect with adequate safety margins because of its anatomical complexity. We herein report our experiences with synovial sarcoma in this region, and review the literature regarding the management of such cases. We retrospectively examined four cases of synovial sarcoma arising from the temporomandibular joint (TMJ) area and infratemporal fossa. Only one patient remains alive without disease, while the other three patients have died. The local control of these tumors has improved because of the progress in the surgical operation methods, while it is expected that there is still a high rate of deaths due to distant metastasis increase. The development of strong chemotherapy is needed for the use after the initial treatment and surgery. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

NASA's UAS NAS Access Project

NASA Technical Reports Server (NTRS)

Johnson, Charles W.

2011-01-01

The vision of the Unmanned Aircraft System (UAS) Integration in the National Airspace System (NAS) Project is "A global transportation system which allows routine access for all classes of UAS." The goal of the UAS Integration in the NAS Project is to "contribute capabilities that reduce technical barriers related to the safety and operational challenges associated with enabling routine UAS access to the NAS." This goal will be accomplished through a two-phased approach based on development of system-level integration of key concepts, technologies and/or procedures, and demonstrations of integrated capabilities in an operationally relevant environment. Phase 1 will take place the first two years of the Project and Phase 2 will take place the following three years. The Phase 1 and 2 technical objectives are: Phase 1: Developing a gap analysis between current state of the art and the Next Generation Air Transportation System (NextGen) UAS Concept of Operations . Validating the key technical areas identified by this Project . Conducting initial modeling, simulation, and flight testing activities . Completing Sub-project Phase 1 deliverables (spectrum requirements, comparative analysis of certification methodologies, etc.) and continue Phase 2 preparation (infrastructure, tools, etc.) Phase 2: Providing regulators with a methodology for developing airworthiness requirements for UAS, and data to support development of certifications standards and regulatory guidance . Providing systems-level, integrated testing of concepts and/or capabilities that address barriers to routine access to the NAS. Through simulation and flight testing, address issues including separation assurance, communications requirements, and human systems integration in operationally relevant environments. The UAS in the NAS Project will demonstrate solutions in specific technology areas, which will address operational/safety issues related to UAS access to the NAS. Since the resource allocation for

Nili Fossae in Natural Color and Across the Spectrum

NASA Technical Reports Server (NTRS)

2007-01-01

The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) took this image of the Nili Fossae region at 0643 UTC (2:43 a.m. EDT) on June 21, 2007, near 21.15 degrees north latitude, 74.24 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 20 meters (66 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point, and is one of several dozen that CRISM has taken to map the minerals at candidate landing sites for the Mars Science Laboratory (MSL) mission, which will launch in 2010.

The Nili Fossae region is critical to understanding the history of water on Mars and whether water ever formed environments suitable for life, because the region is underlain by a layer of phyllosilicate (clay) minerals. This type of mineralogy formed where water was in contact with Mars' crustal rocks for very long periods, altering the silicates in volcanic rocks. In addition, phyllosilicates can encapsulate and preserve organic chemicals associated with life (if life was present). Its rocky record of an ancient wet environment makes Nili Fossae a top contender among the 30-plus landing sites being considered for MSL, whose objectives include measuring the chemistry preserved in an ancient wet environment.

This series of four different versions of the same 544-color image illustrates the mineral-mapping capability that comes from moving beyond the wavelength range of the human eye, and into infrared wavelengths where minerals leave distinct 'fingerprints' in reflected sunlight. At upper left, more than three dozen of the distinct wavelengths measured by CRISM were combined to mimic how the human eye would see the image. The subtle shading comes from the Sun's position high in Mars' sky when the image was taken, creating few shadows. The bland, butterscotch color comes from the dust coating nearly all of the Martian surface to some degree. At upper right

Nucleotide-dependent switch in proteasome assembly mediated by the Nas6 chaperone

PubMed Central

Li, Frances; Tian, Geng; Langager, Deanna; Sokolova, Vladyslava; Finley, Daniel; Park, Soyeon

2017-01-01

The proteasome is assembled via the nine-subunit lid, nine-subunit base, and 28-subunit core particle (CP). Previous work has shown that the chaperones Rpn14, Nas6, Hsm3, and Nas2 each bind a specific ATPase subunit of the base and antagonize base–CP interaction. Here, we show that the Nas6 chaperone also obstructs base–lid association. Nas6 alternates between these two inhibitory modes according to the nucleotide state of the base. When ATP cannot be hydrolyzed, Nas6 interferes with base–lid, but not base–CP, association. In contrast, under conditions of ATP hydrolysis, Nas6 obstructs base–CP, but not base–lid, association. Modeling of Nas6 into cryoelectron microscopy structures of the proteasome suggests that Nas6 controls both base–lid affinity and base–CP affinity through steric hindrance; Nas6 clashes with the lid in the ATP-hydrolysis–blocked proteasome, but clashes instead with the CP in the ATP-hydrolysis–competent proteasome. Thus, Nas6 provides a dual mechanism to control assembly at both major interfaces of the proteasome. PMID:28137839

Cerebrospinal fluid leaks following spinal or posterior fossa surgery: use of fat grafts for prevention and repair.

PubMed

Black, P

2000-01-01

Cerebrospinal fluid (CSF) leaks are relatively common following spinal or posterior fossa surgery. A midline dural tear in the spine is readily repaired by direct application of a suture. However, far-lateral or ventral dural tears are problematic. Fat is an ideal sealant because it is impermeable to water. In this paper the author reports his experience with using fat grafts for the prevention or repair of CSF leaks and proposes a technique in which a large sheet of fat, harvested from the patient's subcutaneous layer, is used to cover not only the dural tear(s) but all of the exposed dura and is tucked into the lateral recess. This procedure prevents CSF from seeping around the fat, which may be tacked to the dura with a few sutures. Fibrin glue is spread on the surface of the fat and is further covered with Surgicel or Gelfoam. For ventral dural tears (associated with procedures in which disc material is excised), fat is packed into the disc space to seal off the ventral dural leak. Leaks in the posterior fossa are managed similarly to those in the spine. Dural suture lines, following suboccipital or spinal intradural exploration, are prophylactically protected from CSF leakage in the same manner. With one exception, 27 dural tears noted during 1650 spinal procedures were successfully repaired using this technique. There was one case of postoperative CSF leakage in 150 cases in which intradural exploration for tumor or other lesions was undertaken. Both postoperative CSF leaks were controlled by applying additional skin sutures. The use of a fat graft is recommended as a rapid, effective means of prevention and repair of CSF leaks following posterior fossa and spinal surgery.

Incidence, Risks, and Sequelae of Posterior Fossa Syndrome in Pediatric Medulloblastoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korah, Mariam P., E-mail: mariam@radonc.emory.or; Esiashvili, Natia; Mazewski, Claire M.

2010-05-01

Purpose: To investigate the incidence, risks, severity, and sequelae of posterior fossa syndrome (PFS) in children with medulloblastoma. Methods and Materials: Between 1990 and 2007, 63 children with medulloblastoma at Emory University and Children's Healthcare of Atlanta were treated with craniectomy followed by radiation. Fifty-one patients were assigned to a standard-risk group, and 12 patients were assigned to a high-risk group. Five patients had <1.5-cm{sup 2} residual tumor, 4 had >=1.5-cm{sup 2} residual tumor, and the remainder had no residual tumor. Eleven patients had disseminated disease. Patients received craniospinal irradiation at a typical dose of 23.4 Gy or 36 Gymore » for standard- or high-risk disease, respectively. The posterior fossa was given a total dose of 54 or 55.8 Gy. Nearly all patients received chemotherapy following cooperative group protocols. Results: Median follow-up was 7 years. PFS developed in 18 patients (29%). On univariate analysis, brainstem invasion, midline tumor location, younger age, and the absence of radiographic residual tumor were found to be predictors of PFS; the last two variables remained significant on multivariate analysis. From 1990 to 2000 and from 2001 to 2007, the proportions of patients with no radiographic residual tumor were 77% and 94%, respectively. During the same eras, the proportions of patients with PFS were 17% and 39%. Only 4 patients had complete recovery at last follow-up. Conclusions: The incidence of PFS increased in the latter study period and is proportional to more aggressive surgery. Children with midline tumors exhibiting brainstem invasion are at increased risk. With the increased incidence of PFS and the permanent morbidity in many patients, the risks and benefits of complete tumor removal in all patients need to be reexamined.« less

The correlation between hematoma volume and outcome in ruptured posterior fossa arteriovenous malformations indicates the importance of surgical evacuation of hematomas.

PubMed

Yilmaz, Adem; Musluman, Ahmet Murat; Kanat, Ayhan; Cavusoglu, Halit; Terzi, Yuksel; Aydin, Yunus

2011-01-01

The correlation between hematoma volume and outcome in ruptured arteriovenous malformations (AVM) with accompanying posterior fossa hematoma was retrospectively evaluated. Microsurgery operations were performed on 127 patients with intracranial AVM between January 1998 and January 2009 at our clinic. Fifteen (11.8%) patients were identified as suffering from posterior fossa AVM, and twelve of these patients presented with a cerebellar hematoma. All patients were clinically evaluated according to the following criteria: modified Rankin Scale (mRS) prior to surgery, Spetzler-Martin grade (SMG) of the AVMs, hematoma volume prior to surgery, and mRS following surgery. Postoperative mRS scores were significantly lower than preoperative scores (p=0.0001). Postoperative outcomes were concordant with the SMG of the AVMs (r=0.67, p=0.033), hematoma volume (r=0.537, p=0.072) and preoperative mRS scores (r=0.764, p=0.004). These analyses show that the postoperative mRS score is strongly correlated with a preoperative mRS score, hematoma volume and SMG. Posterior fossa AVMs present an increased risk for hemorrhage and for increased morbidity and mortality. Cases with hematoma should be operated on an urgent basis. We conclude that hematoma volume is a factor that impacts postoperative results and prognosis. SMG and preoperative mRS scores were also correlated with outcome.

Comparative morphology and histology of the nasal fossa in four mammals: gray squirrel, bobcat, coyote and white-tailed deer

PubMed Central

Yee, Karen K.; Craven, Brent A.; Wysocki, Charles J.; Van Valkenburgh, Blaire

2016-01-01

Although the anatomy of the nasal fossa is broadly similar among terrestrial mammals, differences are evident in the intricacies of nasal turbinal architecture, which varies from simple scroll-like to complex branching forms, and in the extent of nonsensory and olfactory epithelium covering the turbinals. In this study, detailed morphological and immunohistochemical examinations and quantitative measurements of the turbinals and epithelial lining of the nasal fossa were conducted in an array of species that include the gray squirrel, bobcat, coyote, and white-tailed deer. Results show that much more of the nose is lined with olfactory epithelium in the smallest species (gray squirrel) than in the larger species. In two species with similar body masses, bobcat and coyote, the foreshortened felid snout influences turbinal size and results in a decrease of olfactory epithelium on the ethmoturbinals relative to the longer canine snout. Ethmoturbinal surface area exceeds that of the maxilloturbinals in all four sampled animals, except the white-tailed deer, in which the two are similar in size. Combining our results with published data from a broader array of mammalian noses, it is apparent that olfactory epithelial surface area is influenced by body mass, but is also affected by aspects of life history, such as diet and habitat, as well as skull morphology, itself a product of multiple compromises between various functions, such as feeding, vision, and cognition. The results of this study warrant further examination of other mammalian noses to broaden our evolutionary understanding of nasal fossa anatomy. PMID:27090617

Supratentorial Neurometabolic Alterations in Pediatric Survivors of Posterior Fossa Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rueckriegel, Stefan M., E-mail: rueckriegel.s@nch.uni-wuerzburg.de; Driever, Pablo Hernaiz; Bruhn, Harald

2012-03-01

Purpose: Therapy and tumor-related effects such as hypoperfusion, internal hydrocephalus, chemotherapy, and irradiation lead to significant motor and cognitive sequelae in pediatric posterior fossa tumor survivors. A distinct proportion of those factors related to the resulting late effects is hitherto poorly understood. This study aimed at separating the effects of neurotoxic factors on central nervous system metabolism by using H-1 MR spectroscopy to quantify cerebral metabolite concentrations in these patients in comparison to those in age-matched healthy peers. Methods and Materials: Fifteen patients with World Health Organization (WHO) I pilocytic astrocytoma (PA) treated by resection only, 24 patients with WHOmore » IV medulloblastoma (MB), who additionally received chemotherapy and craniospinal irradiation, and 43 healthy peers were investigated using single-volume H-1 MR spectroscopy of parietal white matter and gray matter. Results: Concentrations of N-acetylaspartate (NAA) were significantly decreased in white matter (p < 0.0001) and gray matter (p < 0.0001) of MB patients and in gray matter (p = 0.005) of PA patients, compared to healthy peers. Decreased creatine concentrations in parietal gray matter correlated significantly with older age at diagnosis in both patient groups (MB patients, p = 0.009, r = 0.52; PA patients, p = 0.006, r = 0.7). Longer time periods since diagnosis were associated with lower NAA levels in white matter of PA patients (p = 0.008, r = 0.66). Conclusions: Differently decreased NAA concentrations were observed in both PA and MB groups of posterior fossa tumor patients. We conclude that this reflects a disturbance of the neurometabolic steady state of normal-appearing brain tissue due to the tumor itself and to the impact of surgery in both patient groups. Further incremental decreases of metabolite concentrations in MB patients may point to additional harm caused by irradiation and chemotherapy. The stronger decrease of NAA in

Posterior fossa scintiangiography: documentation of genetic penetrance of von Hippel--Lindau syndrome in a clinically unaffected girl and her father

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hattner, R.S.

1975-09-01

The syndrome of von Hippel and Lindau is a rare hereditary disorder constituted by retinal angiomata, posterior fossa and spinal cord hemangioblastomata, cystic and adenomatous dysplasia of major organs, and occasionally renal cell carcinomata. Although the syndrome is transmitted by an autosomal dominant gene, the penetrance is variable and affected persons may have any or all of the elements of the disease. The 16-year-old clinically normal daughter of a patient with the von Hippel--Lindau syndrome demonstrated a vascular posterior fossa lesion on /sup 99m/Tc-DTPA scintiangiography that failed detection in delayed images. Contrast arteriography corroborated the presence of a hemangioblastoma. Noninvasivemore » demonstration of the genetic penetrance of this disorder offers its victims an opportunity for low morbidity early surgical cure of the associated brain lesions. (auth)« less

Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus

NASA Technical Reports Server (NTRS)

Zimbelman, J. R.

2009-01-01

This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geo-logic maps, generated under an earlier PGG mapping grant.

Determination of composition of non-homogeneous GaInNAs layers

NASA Astrophysics Data System (ADS)

Pucicki, D.; Bielak, K.; Ściana, B.; Radziewicz, D.; Latkowska-Baranowska, M.; Kováč, J.; Vincze, A.; Tłaczała, M.

2016-01-01

Dilute nitride GaInNAs alloys grown on GaAs have become perspective materials for so called low-cost GaAs-based devices working within the optical wavelength range up to 1.6 μm. The multilayer structures of GaInNAs/GaAs multi-quantum well (MQW) samples usually are analyzed by using high resolution X-ray diffraction (HRXRD) measurements. However, demands for precise structural characterization of the GaInNAs containing heterostructures requires taking into consideration all inhomogeneities of such structures. This paper describes some of the material challenges and progress in structural characterization of GaInNAs layers. A new algorithm for structural characterization of dilute nitrides which bounds contactless electro-reflectance (CER) or photo-reflectance (PR) measurements and HRXRD analysis results together with GaInNAs quantum well band diagram calculation is presented. The triple quantum well (3QW) GaInNAs/GaAs structures grown by atmospheric-pressure metalorganic vapor-phase epitaxy (AP-MOVPE) were investigated according to the proposed algorithm. Thanks to presented algorithm, more precise structural data including the nonuniformity in the growth direction of GaInNAs/GaAs QWs were achieved. Therefore, the proposed algorithm is mentioned as a nondestructive method for characterization of multicomponent inhomogeneous semiconductor structures with quantum wells.

NATIONAL ALCOHOL SURVEY (NAS)

EPA Science Inventory

National Alcohol Survey (NAS) is designed to assess the trends in drinking practices and problems in the national population, including attitudes, norms, treatment and experiences and adverse consequences. It also studies the effects of public policy on drinking practices (i.e., ...

UAS NAS IHITL Test Readiness Review (TRR)

NASA Technical Reports Server (NTRS)

Murphy, Jim; Brignola, Michael P.; Rorie, Conrad; Santiago, Confesor; Guminsky, Mike; Cross, Ken

2014-01-01

Requesting release of IHITL test readiness review (TRR) charts to ensure UAS-NAS project primary stakeholders, the Federal Aviation Administration through the RTCA special committee -228 and the Office of the Secretary of Defense Sense and Avoid Science and Research Panel, are well informed on the IHITL test plan and expected outcomes as they relate to their needs to safely fly UAS in the NAS.

Role of Cerebellum in Fine Speech Control in Childhood: Persistent Dysarthria after Surgical Treatment for Posterior Fossa Tumour

ERIC Educational Resources Information Center

Morgan, A. T.; Liegeois, F.; Liederkerke, C.; Vogel, A. P.; Hayward, R.; Harkness, W.; Chong, K.; Vargha-Khadem, F.

2011-01-01

Dysarthria following surgical resection of childhood posterior fossa tumour (PFT) is most commonly documented in a select group of participants with mutism in the acute recovery phase, thus limiting knowledge of post-operative prognosis for this population of children as a whole. Here we report on the speech characteristics of 13 cases seen…

Posterior Fossa Craniotomy for Adherent Fourth Ventricle Neurocysticercosis.

PubMed

Franko, Lynze R; Pandian, Balaji; Gupta, Avneesh; Savastano, Luis E; Chen, Kevin S; Riddell, James; Orringer, Daniel A

2018-06-14

Neurocysticercosis (NCC) is an infectious helminthic disease often presenting in patients who have immigration or travel history from areas where NCC is endemic. Fourth ventricle cysts from NCC pose a unique treatment challenge, as there is little consensus on the best treatment. This case study describes the treatment of a patient with fourth ventricle neurocysticercosis (FVNCC), examines the therapeutic decision-making, and provides a video of a posterior fossa craniotomy (PFC) resection of a degenerative cyst. The patient presented with headache, dizziness, nausea, and memory difficulties. A fourth ventricle cyst consistent with NCC was found on magnetic resonance imaging, and serum enzyme-linked immunosorbent assay (ELISA) confirmed the diagnosis. The cyst was removed utilizing an open PFC followed by antihelminthic therapy and corticosteroids. There was resolution of symptoms at 9 mo postoperatively. Several treatment modalities have been proposed for isolated cysts in the fourth ventricle, including medication, ventriculoperitoneal shunt, endoscopic removal, and PFC. The treatment decision is complex, and there is little guidance on the best treatment choices. In this article, we describe treatment via PFC for an adherent FVNCC cyst.

Appearance of fetal posterior fossa at 11-14 weeks in fetuses with Dandy-Walker malformation or chromosomal anomalies.

PubMed

Volpe, P; Contro, E; Fanelli, T; Muto, B; Pilu, G; Gentile, M

2016-06-01

To describe the sonographic appearance of fetal posterior fossa anatomy at 11-14 weeks of pregnancy and to assess the outcome of fetuses with increased intracranial translucency (IT) and/or brainstem-to-occipital bone (BSOB) diameter. Reference ranges for brainstem (BS), IT and cisterna magna (CM) measurements, BSOB diameter and the BS : BSOB ratio were obtained from the first-trimester ultrasound examination of 233 fetuses with normal postnatal outcome (control group). The intraobserver and interobserver variability of measurements were investigated using 73 stored ultrasound images. In addition, a study group of 17 fetuses with increased IT and/or BSOB diameter was selected to assess outcome. No significant intraobserver or interobserver variability was found for any measurement in the control group. In the study group, IT was increased in all cases and BSOB diameter was above the 95(th) centile of the calculated normal range in all but two (88%) cases. In 13/17 study cases, only two of the three posterior brain spaces were recognized on ultrasound. These 13 fetuses had a larger BSOB diameter than did the four cases that showed all three posterior brain spaces, and had severe associated anomalies including Dandy-Walker malformation (DWM) and/or chromosomal anomalies. Visualization of the fetal posterior fossa anatomy at 11-14 weeks' gestation is feasible. Increased fluid in the posterior brain at 11-14 weeks, particularly in the case of non-visibility of the septation that divides the future fourth ventricle from the CM, is an important risk factor for cystic posterior fossa malformations, in particular DWM, and/or chromosomal aberrations. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Comparative Morphology and Histology of the Nasal Fossa in Four Mammals: Gray Squirrel, Bobcat, Coyote, and White-Tailed Deer.

PubMed

Yee, Karen K; Craven, Brent A; Wysocki, Charles J; Van Valkenburgh, Blaire

2016-07-01

Although the anatomy of the nasal fossa is broadly similar among terrestrial mammals, differences are evident in the intricacies of nasal turbinal architecture, which varies from simple scroll-like to complex branching forms, and in the extent of nonsensory and olfactory epithelium covering the turbinals. In this study, detailed morphological and immunohistochemical examinations and quantitative measurements of the turbinals and epithelial lining of the nasal fossa were conducted in an array of species that include the gray squirrel, bobcat, coyote, and white-tailed deer. Results show that much more of the nose is lined with olfactory epithelium in the smallest species (gray squirrel) than in the larger species. In two species with similar body masses, bobcat and coyote, the foreshortened felid snout influences turbinal size and results in a decrease of olfactory epithelium on the ethmoturbinals relative to the longer canine snout. Ethmoturbinal surface area exceeds that of the maxilloturbinals in all four sampled animals, except the white-tailed deer, in which the two are similar in size. Combining our results with published data from a broader array of mammalian noses, it is apparent that olfactory epithelial surface area is influenced by body mass, but is also affected by aspects of life history, such as diet and habitat, as well as skull morphology, itself a product of multiple compromises between various functions, such as feeding, vision, and cognition. The results of this study warrant further examination of other mammalian noses to broaden our evolutionary understanding of nasal fossa anatomy. Anat Rec, 299:840-852, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

National Airspace System (NAS) open system architecture and protocols

DOT National Transportation Integrated Search

2003-08-14

This standard establishes the open systems data communications architecture and authorized protocol standards for the National Airspace System (NAS). The NAS will consist of various types of processors and communications networks procured from a vari...

Condyle fossa relationship associated with functional posterior crossbite, before and after rapid maxillary expansion.

PubMed

Leonardi, Rosalia; Caltabiano, Mario; Cavallini, Costanza; Sicurezza, Edoardo; Barbato, Ersilia; Spampinato, Concetto; Giordano, Daniela

2012-11-01

To investigate condylar symmetry and condyle fossa relationships in subjects with functional posterior crossbite comparing findings before and after rapid maxillary expansion (RME) treatment through low-dose computed tomography (CT). Twenty-six patients (14 girls and 12 boys, mean age 9.6 ± 1.4 years) with functional posterior crossbite (FPXB) diagnosis underwent rapid palatal expansion with a Hyrax appliance. Patients' temporomandibular joints (TMJ) underwent multislice CT scans before rapid palatal expansion (T0) and after (T1). Joint spaces were compared with those of a control sample of 13 subjects (7 girls and 5 boys, mean age 11 ± 0.6 years). Anterior space (AS), superior space (SS), and posterior space (PS) joint space measurements at T0 between the FPXB side and contralateral side demonstrated no statistically significant differences. After RME treatment (T1), all three joint spaces increased on both the FPXB side and the non-crossbite side. However, differences were statistically significant only for the SS when comparing the two sides at T1. SS increased more than AS and PS in the non-crossbite condyle (0.28 mm) and FPXB condyle (0.37 mm), and PS increased only on the FPXB side (0.34 mm). There were no statistically significant differences in condyle position within the glenoid fossa between the FPXB and non-crossbite side before treatment. Increases in joint spaces were observed after treatment with RME on both sides. These changes were, however, of small amounts.

Transarterial treatment with Onyx of Cognard type IV anterior cranial fossa dural arteriovenous fistulas.

PubMed

Li, Chuanhui; Wu, Zhongxue; Yang, Xinjian; Li, Youxiang; Jiang, Chuhan; He, Hongwei

2014-03-01

Cognard type IV anterior cranial fossa dural arteriovenous fistulas (DAVFs) are rare lesions with a high risk of intracranial hemorrhage. We present our experience with the use of Onyx via the arterial route in these aggressive lesions. Between October 2009 and October 2011, six consecutive patients diagnosed with Cognard type IV anterior cranial fossa DAVFs were treated transarterially with Onyx in our department. All patients were male; mean age was 55 years (range 38-68). Four patients presented with intracranial hemorrhage as the initial manifestation; one patient presented with seizures at the time of diagnosis and experienced intracranial hemorrhage during the antiepileptic therapy; and the other patient was asymptomatic. In five patients, complete obliteration was achieved with transarterial Onyx injection in a single treatment session; in the remaining patient, subtotal occlusion was achieved and gamma knife treatment was followed. The average time of injection was 19 min (range 5-28) for every pedicle catheterized and the average amount of Onyx was 3.2 ml (range 0.4-6.3) for each lesion. All patients recovered uneventfully after embolization. No mortality or permanent morbidity was observed in this series. Follow-up digital subtraction or MR angiography confirmed durable obliteration of the fistulas in five cured cases. No patients suffered intracranial hemorrhage during the follow-up period. In this small series, our experience with the use of Onyx for arterial embolization of Cognard type IV DAVFs is encouraging, with durable complete cure in most lesions without severe complications.

Natural attenuation software (NAS): Assessing remedial strategies and estimating timeframes

USGS Publications Warehouse

Mendez, E.; Widdowson, M.; Chapelle, F.; Casey, C.

2005-01-01

Natural Attenuation Software (NAS) is a screening tool to estimate remediation timeframes for monitored natural attenuation (MNA) and to assist in decision-making on the level of source zone treatment in conjunction with MNA using site-specific remediation objectives. Natural attenuation processes that NAS models include are advection, dispersion, sorption, non-aqueous phase liquid (NAPL) dissolution, and biodegradation of either petroleum hydrocarbons or chlorinated ethylenes. Newly-implemented enhancements to NAS designed to maximize the utility of NAS for site managers were observed. NAS has expanded source contaminant specification options to include chlorinated ethanes and chlorinated methanes, and to allow for the analysis of any other user-defined contaminants that may be subject to microbially-mediated transformations (heavy metals, radioisotopes, etc.). Included is the capability to model co-mingled plumes, with constituents from multiple contaminant categories. To enable comparison of remediation timeframe estimates between MNA and specific engineered remedial actions , NAS was modified to incorporate an estimation technique for timeframes associated with pump-and-treat remediation technology for comparison to MNA. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

NAS Grid Benchmarks. 1.0

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob; Frumkin, Michael; Biegel, Bryan A. (Technical Monitor)

2002-01-01

We provide a paper-and-pencil specification of a benchmark suite for computational grids. It is based on the NAS (NASA Advanced Supercomputing) Parallel Benchmarks (NPB) and is called the NAS Grid Benchmarks (NGB). NGB problems are presented as data flow graphs encapsulating an instance of a slightly modified NPB task in each graph node, which communicates with other nodes by sending/receiving initialization data. Like NPB, NGB specifies several different classes (problem sizes). In this report we describe classes S, W, and A, and provide verification values for each. The implementor has the freedom to choose any language, grid environment, security model, fault tolerance/error correction mechanism, etc., as long as the resulting implementation passes the verification test and reports the turnaround time of the benchmark.

New NAS Parallel Benchmarks Results

NASA Technical Reports Server (NTRS)

Yarrow, Maurice; Saphir, William; VanderWijngaart, Rob; Woo, Alex; Kutler, Paul (Technical Monitor)

1997-01-01

NPB2 (NAS (NASA Advanced Supercomputing) Parallel Benchmarks 2) is an implementation, based on Fortran and the MPI (message passing interface) message passing standard, of the original NAS Parallel Benchmark specifications. NPB2 programs are run with little or no tuning, in contrast to NPB vendor implementations, which are highly optimized for specific architectures. NPB2 results complement, rather than replace, NPB results. Because they have not been optimized by vendors, NPB2 implementations approximate the performance a typical user can expect for a portable parallel program on distributed memory parallel computers. Together these results provide an insightful comparison of the real-world performance of high-performance computers. New NPB2 features: New implementation (CG), new workstation class problem sizes, new serial sample versions, more performance statistics.

Fluvio geomorphic set-up of Noctis Fossae in Noctis Labyrinthus of Syria-Planum Provenance, Mars

NASA Astrophysics Data System (ADS)

Chavan, A. A.; Bhandari, S.

2017-12-01

The modern era of planetary exploration has revealed fluvial or fluvial like landforms on the extraterrestrial surfaces of planets and moons of our solar system. This has posed as interesting challenges for advancing our fundamental understanding of fluvial processes and their associated landforms on the planetary surfaces especially on Mars. It has been recognized through earlier studies that the channels and valleys are extensively dissected on Mars. The Valleys are low lying, elongate troughs surrounded by elevated topography. Moreover, valley networks on Mars are the most noticeable features attesting that different geological processes and possibly climatic conditions prevailed in the past and played a vital role in formulating the Martian topography. Channel incisions which are a domino effect both tectonic and surface runoff and groundwater sapping. The components of surface runoff have been deciphered with the help of morphometric exercises. Further, the geomorphological studies of these landforms are critical in understanding the regional tectonics. The present work is an assessment of Fluvio geomorphic set-up of Noctis Fossae in Noctis Labyrinthus of Syria-Planum Provenance, Mars. This study focuses on the fluvio geomorphology of the southern highlands (00 to 400S to 850-1200W) to determine how these features were formed, which process formed these valleys and includes the probable causes resulting into the development of the topography. Keywords: Noctis Fossae; Noctis Labyrinthus; Syria Planum; Mars

The NAS Computational Aerosciences Archive

NASA Technical Reports Server (NTRS)

Miceli, Kristina D.; Globus, Al; Lasinski, T. A. (Technical Monitor)

1995-01-01

In order to further the state-of-the-art in computational aerosciences (CAS) technology, researchers must be able to gather and understand existing work in the field. One aspect of this information gathering is studying published work available in scientific journals and conference proceedings. However, current scientific publications are very limited in the type and amount of information that they can disseminate. Information is typically restricted to text, a few images, and a bibliography list. Additional information that might be useful to the researcher, such as additional visual results, referenced papers, and datasets, are not available. New forms of electronic publication, such as the World Wide Web (WWW), limit publication size only by available disk space and data transmission bandwidth, both of which are improving rapidly. The Numerical Aerodynamic Simulation (NAS) Systems Division at NASA Ames Research Center is in the process of creating an archive of CAS information on the WWW. This archive will be based on the large amount of information produced by researchers associated with the NAS facility. The archive will contain technical summaries and reports of research performed on NAS supercomputers, visual results (images, animations, visualization system scripts), datasets, and any other supporting meta-information. This information will be available via the WWW through the NAS homepage, located at http://www.nas.nasa.gov/, fully indexed for searching. The main components of the archive are technical summaries and reports, visual results, and datasets. Technical summaries are gathered every year by researchers who have been allotted resources on NAS supercomputers. These summaries, together with supporting visual results and references, are browsable by interested researchers. Referenced papers made available by researchers can be accessed through hypertext links. Technical reports are in-depth accounts of tools and applications research projects

Safety of Venipuncture Sites at the Cubital Fossa as Assessed by Ultrasonography.

PubMed

Mukai, Kanae; Nakajima, Yukari; Nakano, Tomotaka; Okuhira, Manami; Kasashima, Aya; Hayashi, Rina; Yamashita, Misaki; Urai, Tamae; Nakatani, Toshio

2017-11-15

The aim of the present observational study was to identify safe and suitable venipuncture sites for nursing in the clinical setting using ultrasonography to measure the depth and cross-sectional area of each superficial vein before and after tourniquet application as well as the distance between each superficial vein and the median nerve or brachial artery. Twenty healthy volunteers (21.8 [0.6] y) were recruited. The visible rate of each superficial vein before and after tourniquet application was 65% for the basilic vein, 90% to 95% for the median cubital vein, and 65% to 80% for the cephalic vein. The cross-sectional area of the median cubital vein after tourniquet application was significantly larger than that of the basilic vein and cephalic vein. The distance between the basilic vein or median cubital vein and median nerve was significantly smaller than that between the cephalic vein and median nerve. The distance between the basilic vein or median cubital vein and brachial artery was significantly smaller than that between the cephalic vein and brachial artery. These results demonstrated that the cephalic vein at the cubital fossa is a relatively safe venipuncture site because of its distance from the median nerve and brachial artery. When puncturing the cephalic vein is difficult because it is not visible, the median cubital vein at the cubital fossa may be selected for venipuncture due to its cross-sectional area and visibility; however, care is needed to avoid penetrating the vein because the median nerve and brachial artery are located underneath.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Giant Aneurysmal Bone Cyst of the Anterior Cranial Fossa and Paranasal Sinuses Presenting in Pregnancy: Case Report and Literature Review

PubMed Central

Hnenny, Luke; Roundy, Neil; Zherebitskiy, Victor; Grafe, Marjorie; Mansoor, Atiya; Dogan, Aclan

2015-01-01

Background and Purpose Aneurysmal bone cysts (ABCs) rarely involve the cranium and have seldom been reported in pregnancy. Clinical Presentation We describe a case of a 28-year-old woman who presented at 37 weeks of gestation with 3 months of gradually worsening vision, 10 months of proptosis, and restricted ocular motility on the left. Brain imaging revealed a multicystic enhancing mass measuring 5.9 × 5.3 × 3.7 cm, centered on the cribriform plate on the left, extending into the anterior cranial fossa superiorly as well as the left nasal cavity, maxillary, sphenoid, and frontal sinuses. Her clinical course is described in detail; 3-month postoperative imaging demonstrated no residual mass. Conclusion A literature review revealed five previous cases of ABCs associated with pregnancy. We report a rare case of a giant ABC of fibrous dysplasia involving the paranasal sinuses and anterior cranial fossa. We postulate on the possible influence of pregnancy on the clinical course. PMID:26623230

An Implementation Plan for NFS at NASA's NAS Facility

NASA Technical Reports Server (NTRS)

Lam, Terance L.; Kutler, Paul (Technical Monitor)

1998-01-01

This document discusses how NASA's NAS can benefit from the Sun Microsystems' Network File System (NFS). A case study is presented to demonstrate the effects of NFS on the NAS supercomputing environment. Potential problems are addressed and an implementation strategy is proposed.

Radiological imaging detection of tumors localized in fossa cranii posterior.

PubMed

Kabashi, Serbeze; Muçaj, Sefedin; Ahmetgjekaj, Ilir; Gashi, Sanije; Fazliu, Ilir; Dreshaj, Shemsedin; Shala, Nexhmedin

2008-01-01

Intracranial tumors are characterized by a variety imaging aspects and their detection is always a challenge. Clinical application of Magnetic Resonance Imaging (MRI) and Computerized Tomography has provided an earlier detection and treatment of many CNS pathologies. The aim of this study is to estimate the role of CT and MRI in the determination of posterior fossa tumors. During period 2000-2005 in UCCK-Prishtina, 368 patients were diagnosed with intracranial tumors. Fifty-nine of them were found to have tumor localized in fossa crani posterior (FCP) without any significant difference between genders (50.8% female vs. 49.2% male, chi2 test=0.02 p=0.896). The average age of patients with FCP tumors was 33.1 (SD +/- 22.5, rank 1-70). The most of these patients were registered in 2003 (20.3%) whereas the least in 2000 (11.9%). The most affected age-group was 0-9 (25.4%) and 50-59 (23.7%) whereas the incidences was between 30-39 years of age (3.4%). Tumor types that more often were found in young's individuals were: Astrocytomas with a peak incidence in teenagers (average age was 12-year-old SD +/- 7.5, rank 3-23), next was Medulloblastomas (average age was 11-years-old, SD +/- 2.9, rank 6-16 years) and ependymomas (average age was 6.8-years-old, SD +/- 4.6, rank 1-12). Patients with osseous tumors are characterized by older age than median (61.0, SD +/- 4.2, rank 58-64), then metastases (53.0, SD +/- 5.3, rank 45-60) and meningiomas (50.8, SD +/- 7.7, rank 38-63). The overall average mortality was 0.41 cases per 100,000 inhabitants with variations through years from 0.30-0.50/100,000 inhabitants. Comparing with other countries, for some types of FCP tumors, lower morbidity is shown in Kosova, with mean incidence 0.41/100,000. The most frequent tumors in children were medulloblastomas, brainstem gliomas, astrocytomas and ependymomas whereas meningiomas and metastasis were most often found in adults. For FCP tumors detection, MRI had 100% sensitivity, specificity and

Life-threatening macroglossia after posterior fossa surgery: a surgical positioning problem?

PubMed

Vermeersch, G; Menovsky, T; De Ridder, D; De Bodt, M; Saldien, V; Van de Heyning, P

2014-01-01

A 55-year-old woman was operated in the lateral park bench position with significant neck flexion and oral packing. Macroglossia was noticed immediately postoperatively after endotracheal extubation. The patient was reintubated for 13 days and subsequently required a tracheostoma. After the placement of the tracheostoma and the removal of the endotracheal tube, the congestion of the tongue decreased markedly within 24 hours. Macroglossia is a rare complication following posterior fossa procedures with few cases reported so far. It can cause airway obstruction, which could be a life-threatening complication, and it therefore requires prompt treatment. The aetiology of postoperative macroglossia remains uncertain and has been attributed to arterial, venous and lymphatic compression, mechanical compression, or neurogenic causes. This article describes new insights into aetiology and also describes preventive measures and possible treatment.

Reversible dyscognition in patients with a unilateral, middle fossa arachnoid cyst revealed by using a laptop based neuropsychological test battery (CANTAB).

PubMed

Torgersen, Johan; Helland, Christian; Flaatten, Hans; Wester, Knut

2010-11-01

The aim of this study was to evaluate and validate the Cambridge Neuropsychological Test Automated Battery (CANTAB) in a Norwegian group of patients undergoing surgery for middle fossa arachnoid cysts (AC). We also wanted to assess health related quality of life (HRQOL) in these patients to see if it could be improved by decompression of the AC. Adult patients (>18 years) with unilateral middle fossa AC and no previous history of neurological disease, head injury, or a psychiatric disorder were eligible for inclusion. We used four tests from CANTAB to assess the level of neuropsychological performance: paired associate learning (PAL) and delayed matching to sample (DMS) assessed temporal lobe functions, while Stockings of Cambridge (SOC) and intra-extra dimensional (IED) shift focused on frontal lobe functions. Patients with postoperative cerebral complications were reported, but excluded from neuropsychological follow-up. In addition to the CANTAB data, pre- and postoperative clinical and radiological data were collected. HRQOL was assessed using Short Form 36 (SF-36) pre- and postoperatively. We found significant improvement in the two temporal tests assessing memory, but no improvement in the two frontal tests assessing executive function. HRQOL was significantly reduced preoperatively in two of eight SF-36 domains and improved significantly in four domains postoperatively. CANTAB facilitates detection of cognitive improvements after decompression of the cyst in patients with AC in the middle fossa. The improvements were detected on the tests sensitive to temporal lobe problems only, not on the tests more sensitive to frontal lobe affection. This establishes construct validity for CANTAB for the first time in this population.

Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation type I in adult patients

PubMed Central

Chen, Junchen; Li, Yongning; Wang, Tianyu; Gao, Jun; Xu, Jincheng; Lai, Runlong; Tan, Dianhui

2017-01-01

Abstract Chiari malformation type I (CM-I) is a congenital neurosurgical disease about the herniation of cerebellar tonsil through the foramen magnum. A variety of surgical techniques for CM-I have been used, and there is a controversy whether to use posterior fossa decompression with duraplasty (PFDD) or posterior fossa decompression without duraplasty (PFD) in CM-I patients. Here, we compared the clinical results and effectiveness of PFDD and PFD in adult patients with CM-I. The cases of 103 adult CM-I patients who underwent posterior fossa decompression with or without duraplasty from 2008 to 2014 were reviewed retrospectively. Patients were divided into 2 groups according to the surgical techniques: PFDD group (n = 70) and PFD group (n = 33). We compared the demographics, preoperative symptoms, radiographic characteristics, postoperative complications, and clinical outcomes between the PFD and PFDD patients. No statistically significant differences were found between the PFDD and PFD groups with regard to demographics, preoperative symptoms, radiographic characteristics, and clinical outcomes(P > 0.05); however, the postoperative complication aseptic meningitis occurred more frequently in the PFDD group than in the PFD group (P = 0.027). We also performed a literature review about the PFDD and PFD and made a summary of these preview studies. Our study suggests that both PFDD and PFD could achieve similar clinical outcomes for adult CM-I patients. The choice of surgical procedure should be based on the patient's condition. PFDD may lead to a higher complication rate and autologous grafts seemed to perform better than nonautologous grafts for duraplasty. PMID:28121938

[CLINICAL STUDIES ON EFFECT OF ARTHROSCOPIC INTERCONDYLAR FOSSA ANGIOPLASTY ON ABILITY OF NEUROMUSCULAR CONTROL IN ELDERLY PATIENTS WITH KNEE OSTEOARTHRITIS].

PubMed

Huang, Jingmin; Wang, Haijiao; Wu, Jiang; Li, Dongchao; Li, Yuhong

2015-08-01

To study the effect of arthroscopic intercondylar fossa angioplasty on the ability of neuromuscular control of the knee joint in elderly patients with knee osteoarthritis (KOA). Between June 2012 and March 2013, 20 elderly patients with KOA and in accordance with inclusion and exclusion criteria underwent arthroscopic intercondylar fossa angioplasty (operation group), and 20 healthy elderly people served as control group. There was no significant difference in age, height, weight, and body mass index between 2 groups (P > 0.05). The proprioception capability (using passive regeneration test at measurement angles of 15, 30, and 60°) and quadriceps mobilization [including maximum voluntary contraction (MVC), central activation ratio (CAR), and activation deficit (AD)] were measured to avaluate the neuromuscular control of the knee; the Lysholm score was used to evaluate knee function. The above indexes were measured to assess the knee neuromuscular control and recovery of joint function in patients of operation group at 3, 6, and 9 months after operation. Compared with the control group, MVC, CAR, and Lysholm scores were significantly decreased, and the AD and passive knee angle difference were significantly increased in operation group (P < 0.05) before operation. With the time after operation, the Lysholm score, CAR, and MVC increased gradually, and the AD and the passive knee angle difference decreased gradually. There was no significant difference in the indexes between 2 groups at 9 months after operation (P > 0.05). Arthroscopic intercondylar fossa angioplasty can relieve ACL pressure, abrasion, and impact, which will recover the ability of neuromuscular control, increase proprioception and quadriceps mobilization capacity, and improve the joint function.

Spectral classification and mineralogical characterization of Nili Fossae for a better understanding of hydrated mineralogies.

NASA Astrophysics Data System (ADS)

Serventi, Giovanna; Carli, Cristian; Altieri, Francesca; Geminale, Anna; Sgavetti, Maria; Grassi, Davide; Orosei, Roberto; Bellucci, Giancarlo

2017-04-01

The presence of hydrated minerals on Mars provides a record of water-related processes and, in particular, the identification of phyllosilicates puts constraints on the evolution of Mars (Poulet et al., 2005). Even if data from the Observatoire pour la Minèralogie, l'Eau, les Glaces, et l'Activitè (OMEGA) and from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) show the presence of different hydrated minerals, on Mars the spectral regions where hydrated minerals absorb are also affected by atmospheric features due to gaseous components, mostly CO2 and H2O. Among the different methods that have been proposed to separate the atmospheric signatures from the hydrated absorptions, we use the Surface Atmosphere Separation (SAS) method proposed by Geminale et al. (2015) to analyze the Nili Fossae region (in particular, four MEX orbit have been selected and a mosaic have been created). In this work, we spectrally classify the Nili Fossae region using the Spectral Angle Mapping (SAM, Kruse et al., 1993) classification and using a spectral library iteratively built from the image though the Pixel Purity Index (PPI, Boardman, 1995). Mainly, we recognized five spectral regions dominated by: iron-hydroxides, pyroxenes (both orthopyroxene and clinopyroxene), olivine and phyllosilicates, in accordance with the literature. Then, we focused on the hydrated regions: absorptions in the 1.9-2.3 µm are fundamental to recognize a hydrated mineralogy, and to discriminate between phyllosilicates characterized by different cations in the octahedral environment. Comparing our results with maps from Mangold et al. (2007) and Poulet et al (2007), we demonstrated that the SAS+SAM technique permits to identify hydrated regions that cannot be easily recognized using the spectral mapping applied to images corrected with Mons Olympus method (Langevin et al., 2005). Furthermore, applying the MGM algorithm to a set of spectra selected from hydrated regions, we recognized the

Anterolateral corridor approach to the infratemporal fossa and central skull base in maxillectomy: rationale and technical aspects.

PubMed

McMahon, Jeremy D; Crowther, John; Taylor, William M; Wong, Ling Siew; Paterson, Tom; Devine, John; Wales, Craig; MacIver, Colin

2015-11-01

We describe the technical aspects and report our clinical experience of a surgical approach to the infratemporal fossa that aims to reduce local recurrence after operations for cancer of the posterior maxilla. We tested the technique by operating on 3 cadavers and then used the approach in 16 patients who had posterolateral maxillectomy for disease that arose on the maxillary alveolus or junction of the hard and soft palate (maxillary group), and in 19 who had resection of the masticatory compartment and central skull base for advanced sinonasal cancer (sinonasal group). Early proximal ligation of the maxillary artery was achieved in all but one of the 35 patients. Access to the infratemporal fossa enabled division of the pterygoid muscles and pterygoid processes under direct vision in all cases. No patient in the maxillary group had local recurrence at median follow up of 36 months. Four patients (21%) in the sinonasal group had local recurrence at median follow up of 27 months. Secondary haemorrhage from the cavernous segment of the internal carotid artery resulted in the only perioperative death. The anterolateral corridor approach enables controlled resection of tumours that extend into the masticatory compartment. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

NAS infrastructure management system build 1.5 computer-human interface

DOT National Transportation Integrated Search

2001-01-01

Human factors engineers from the National Airspace System (NAS) Human Factors Branch (ACT-530) of the Federal Aviation Administration William J. Hughes Technical Center conducted an evaluation of the NAS Infrastructure Management System (NIMS) Build ...

Delineation of Two Clinically and Molecularly Distinct Subgroups of Posterior Fossa Ependymoma

PubMed Central

Witt, Hendrik; Mack, Stephen C.; Ryzhova, Marina; Bender, Sebastian; Sill, Martin; Isserlin, Ruth; Benner, Axel; Hielscher, Thomas; Milde, Till; Remke, Marc; Jones, David T.W.; Northcott, Paul A.; Garzia, Livia; Bertrand, Kelsey C.; Wittmann, Andrea; Yao, Yuan; Roberts, Stephen S.; Massimi, Luca; Van Meter, Tim; Weiss, William A.; Gupta, Nalin; Grajkowska, Wiesia; Lach, Boleslaw; Cho, Yoon-Jae; von Deimling, Andreas; Kulozik, Andreas E.; Witt, Olaf; Bader, Gary D.; Hawkins, Cynthia E.; Tabori, Uri; Guha, Abhijit; Rutka, James T.; Lichter, Peter; Korshunov, Andrey

2014-01-01

Summary Despite the histological similarity of ependymomas from throughout the neuroaxis, the disease likely comprises multiple independent entities, each with a distinct molecular pathogenesis. Transcriptional profiling of two large independent cohorts of ependymoma reveals the existence of two demographically, transcriptionally, genetically, and clinically distinct groups of posterior fossa (PF) ependymomas. Group A patients are younger, have laterally located tumors with a balanced genome, and are much more likely to exhibit recurrence, metastasis at recurrence, and death compared with Group B patients. Identification and optimization of immunohistochemical (IHC) markers for PF ependymoma subgroups allowed validation of our findings on a third independent cohort, using a human ependymoma tissue microarray, and provides a tool for prospective prognostication and stratification of PF ependymoma patients. PMID:21840481

Trans aqueductal, third ventricle - Cervical subarachnoid stenting: An adjuvant cerebro spinal fluid diversion procedure in midline posterior fossa tumors with hydrocephalus: The technical note and case series.

PubMed

Teegala, Ramesh

2016-01-01

Persistent or progressive hydrocephalus is one of the complex problems of posterior fossa tumors associated with hydrocephalus. The author evaluated the effectiveness of single-stage tumor decompression associated with a stent technique (trans aqueductal third ventricle - Cervical subarachnoid stenting) as an adjuvant cerebro spinal fluid (CSF) diversion procedure in controlling the midline posterior fossa tumors with hydrocephalus. Prospective clinical case series of 15 patients was evaluated from July 2006 to April 2012. Fifteen clinicoradiological diagnosed cases of midline posterior fossa tumors with hydrocephalus were included in this study. All the tumors were approached through the cerebello medullary (telo velo tonsilar) fissure technique. Following the excision of the posterior fossa tumor, a sizable stent was placed across the aqueduct from the third ventricle to the cervical subarachnoid space. There were nine male and six female patients with an average age of 23 years. Complete tumor excision could be achieved in 12 patients and subtotal excision with clearance of aqueduct in remaining three patients. Hydrocephalus was controlled effectively in all the patients. There were no stent-related complications. This study showed the reliability of single-stage tumor excision followed by placement of aqueductal stent. The success rate of this technique is comparable to those of conventional CSF diversion procedures. This is a simple, safe, and effective procedure for the management of persistent and or progressive hydrocephalus. This technique may be very useful in situations where the patient's follow-up is compromised and the patients who are from a poor economic background. Long-term results need further evaluation to assess the overall functioning of this stent technique.

Branchial fistula arising from pyriform fossa: CT diagnosis of a case and discussion of radiological features.

PubMed

Chauhan, Narvir Singh; Sharma, Yash Paul; Bhagra, Tilak; Sud, Bindu

2012-01-01

Anomalies of third or fourth branchial apparatus origin are very uncommon and present as recurrent neck infections or thyroiditis with a predominant left-sided involvement. Radiological diagnosis requires a high index of suspicion and is critical for initiation of proper treatment. We describe a case of branchial sinus of pyriform fossa with external fistulization that presented in adulthood and was diagnosed on computed tomographic scan. The radiological features of this rare anomaly are revisited. Copyright © 2012 Elsevier Inc. All rights reserved.

Fast imaging employing steady-state acquisition (FIESTA) MRI to investigate cerebrospinal fluid (CSF) within dural reflections of posterior fossa cranial nerves.

PubMed

Noble, David J; Scoffings, Daniel; Ajithkumar, Thankamma; Williams, Michael V; Jefferies, Sarah J

2016-11-01

There is no consensus approach to covering skull base meningeal reflections-and cerebrospinal fluid (CSF) therein-of the posterior fossa cranial nerves (CNs VII-XII) when planning radiotherapy (RT) for medulloblastoma and ependymoma. We sought to determine whether MRI and specifically fast imaging employing steady-state acquisition (FIESTA) sequences can answer this anatomical question and guide RT planning. 96 posterior fossa FIESTA sequences were reviewed. Following exclusions, measurements were made on the following scans for each foramen respectively (left, right); internal acoustic meatus (IAM) (86, 84), jugular foramen (JF) (83, 85) and hypoglossal canal (HC) (42, 45). A protocol describes measurement procedure. Two observers measured distances for five cases and agreement was assessed. One observer measured all the remaining cases. IAM and JF measurement interobserver variability was compared. Mean measurement difference between observers was -0.275 mm (standard deviation 0.557). IAM and JF measurements were normally distributed. Mean IAM distance was 12.2 mm [95% confidence interval (CI) 8.8-15.6]; JF was 7.3 mm (95% CI 4.0-10.6). The HC was difficult to visualize on many images and data followed a bimodal distribution. Dural reflections of posterior fossa CNs are well demonstrated by FIESTA MRI. Measuring CSF extension into these structures is feasible and robust; mean CSF extension into IAM and JF was measured. We plan further work to assess coverage of these structures with photon and proton RT plans. Advances in knowledge: We have described CSF extension beyond the internal table of the skull into the IAM, JF and HC. Oncologists planning RT for patients with medulloblastoma and ependymoma may use these data to guide contouring.

A Method for Suppressing Line Overload Phenomena Using NAS Battery Systems

NASA Astrophysics Data System (ADS)

Ohtaka, Toshiya; Iwamoto, Shinichi

In this paper, we pay attention to the superior operating control function and instantaneous discharging characteristics of NAS battery systems, and propose a method for determining installation planning and operating control schemes of NAS battery systems for suppressing line overload phenomena. In the stage of planning, a target contingency is identified, and an optimal allocation and capacity of NAS battery systems and an amount of generation changes are determined for the contingency. In the stage of operation, the control strategy of NAS battery system is determined. Simulations are carried out for verifying the validity of the proposed method using the IEEJ 1 machine V system model and an example 2 machine 16 bus system model.

Multi-stage formation of La Fossa Caldera (Vulcano Island, Italy) from an integrated subaerial and submarine analysis

NASA Astrophysics Data System (ADS)

Casalbore, D.; Romagnoli, C.; Bosman, A.; De Astis, G.; Lucchi, F.; Tranne, C. A.; Chiocci, F. L.

2018-06-01

The analysis of multibeam bathymetry, seismic profiles, ROV dive and seafloor sampling, integrated with stratigraphic and geological data derived from subaerial field studies, provides information on the multi-stage formation and evolution of La Fossa Caldera at the active volcanic system of Vulcano (Aeolian Islands). The caldera is mostly subaerial and delimited by well-defined rims associated to three different collapse events occurred at about 80, 48-24, and 13-8 ka, respectively. The NE part of the caldera presently lies below the sea-level and is delimited by two partially degraded rim segments, encompassing a depressed and eroded area of approximately 2 km2. We present here further morphological and petrochemical evidence linking the subaerial caldera rims to its submarine counterparts. Particularly, one of the submarine rims can be directly correlated with the subaerial eastern caldera border related to the intermediate (48-24 ka) collapse event. The other submarine rim cannot be directly linked to any subaerial caldera rim, because of the emplacement of the Vulcanello lava platform during the last 2 millennia that interrupts the caldera border. However, morphological interpretation and the trachyte composition of dredged lavas allow us to associate this submarine rim with the younger (13-8 ka) caldera collapse event that truncated the trachyte-rhyolite Monte Lentia dome complex in the NW sector of Vulcano. The diachronicity of the different collapse events forming the La Fossa Caldera can also explain the morpho-structural mismatch of some hundreds of meters between the two submarine caldera rims. A small part of this offset could be also accounted by tectonic displacement along NE-SW trending lineaments breaching and dismantling the submarine portion of the caldera. A network of active erosive gullies, whose headwall arrive up to the coast, is in fact responsible of the marked marine retrogressive erosion affecting the NE part of the caldera, where

A decision analysis tool for the assessment of posterior fossa tumour surgery outcomes in children--the "Liverpool Neurosurgical Complication Causality Assessment Tool".

PubMed

Zakaria, Rasheed; Ellenbogen, Jonathan; Graham, Catherine; Pizer, Barry; Mallucci, Conor; Kumar, Ram

2013-08-01

Complications may occur following posterior fossa tumour surgery in children. Such complications are subjectively and inconsistently reported even though they may have significant long-term behavioural and cognitive consequences for the child. This makes comparison of surgeons, programmes and treatments problematic. We have devised a causality tool for assessing if an adverse event after surgery can be classified as a surgical complication using a series of simple questions, based on a tool used in assessing adverse drug reactions. This tool, which we have called the "Liverpool Neurosurgical Complication Causality Assessment Tool", was developed by reviewing a series of ten posterior fossa tumour cases with a panel of neurosurgery, neurology, oncology and neuropsychology specialists working in a multidisciplinary paediatric tumour treatment programme. We have demonstrated its use and hope that it may improve reliability between different assessors both in evaluating the outcomes of existing programmes and treatments as well as aiding in trials which may directly compare the effects of surgical and medical treatments.

Medusae Fossae Formation - High Resolution Image

NASA Technical Reports Server (NTRS)

1998-01-01

An exotic terrain of wind-eroded ridges and residual smooth surfaces are seen in one of the highest resolution images ever taken of Mars from orbit. The Medusae Fossae formation is believed to be formed of the fragmental ejecta of huge explosive volcanic eruptions. When subjected to intense wind-blasting over hundreds of millions of years, this material erodes easily once the uppermost tougher crust is breached. The crust, or cap rock, can be seen in the upper right part of the picture. The finely-spaced ridges are similar to features on Earth called yardangs, which are formed by intense winds plucking individual grains from, and by wind-driven sand blasting particles off, sedimentary deposits.

The image was taken on October 30, 1997 at 11:05 AM PST, shortly after the Mars Global Surveyor spacecraft's 31st closest approach to Mars. The image covers an area 3.6 X 21.5 km (2.2 X 13.4 miles) at 3.6 m (12 feet) per picture element--craters only 11 m (36 feet, about the size of a swimming pool) across can be seen. The best Viking view of the area (VO 1 387S34) has a resolution of 240 m/pixel, or 67 times lower resolution than the MOC frame.

Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

Systematic review and meta-analysis of isolated posterior fossa malformations on prenatal ultrasound imaging (part 1): nomenclature, diagnostic accuracy and associated anomalies.

PubMed

D'Antonio, F; Khalil, A; Garel, C; Pilu, G; Rizzo, G; Lerman-Sagie, T; Bhide, A; Thilaganathan, B; Manzoli, L; Papageorghiou, A T

2016-06-01

To explore the outcome in fetuses with prenatal diagnosis of posterior fossa anomalies apparently isolated on ultrasound imaging. MEDLINE and EMBASE were searched electronically utilizing combinations of relevant medical subject headings for 'posterior fossa' and 'outcome'. The posterior fossa anomalies analyzed were Dandy-Walker malformation (DWM), mega cisterna magna (MCM), Blake's pouch cyst (BPC) and vermian hypoplasia (VH). The outcomes observed were rate of chromosomal abnormalities, additional anomalies detected at prenatal magnetic resonance imaging (MRI), additional anomalies detected at postnatal imaging and concordance between prenatal and postnatal diagnoses. Only isolated cases of posterior fossa anomalies - defined as having no cerebral or extracerebral additional anomalies detected on ultrasound examination - were included in the analysis. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies. We used meta-analyses of proportions to combine data and fixed- or random-effects models according to the heterogeneity of the results. Twenty-two studies including 531 fetuses with posterior fossa anomalies were included in this systematic review. The prevalence of chromosomal abnormalities in fetuses with isolated DWM was 16.3% (95% CI, 8.7-25.7%). The prevalence of additional central nervous system (CNS) abnormalities that were missed at ultrasound examination and detected only at prenatal MRI was 13.7% (95% CI, 0.2-42.6%), and the prevalence of additional CNS anomalies that were missed at prenatal imaging and detected only after birth was 18.2% (95% CI, 6.2-34.6%). Prenatal diagnosis was not confirmed after birth in 28.2% (95% CI, 8.5-53.9%) of cases. MCM was not significantly associated with additional anomalies detected at prenatal MRI or detected after birth. Prenatal diagnosis was not confirmed postnatally in 7.1% (95% CI, 2.3-14.5%) of cases. The rate of chromosomal anomalies in fetuses with

The NAS Alert System: A look at the first eight years

USGS Publications Warehouse

Fuller, Pamela L.; Neilson, Matt; Huge, Dane H.

2013-01-01

The U.S. Geological Survey's Nonindigenous Aquatic Species (NAS) database program (http://nas.er.usgs.gov) tracks the distribution of introduced aquatic organisms across the United States. Awareness of, and timely response to, novel species introductions by those involved in nonindigenous aquatic species management and research requires a framework for rapid dissemination of occurrence data as it is incorporated into the NAS database. In May 2004, the NAS program developed an alert system to notify registered users of new introductions as part of a national early detection/rapid response system. This article summarizes information on system users and dispatched alerts from the system's inception through the end of 2011. The NAS alert system has registered over 1,700 users, with approximately 800 current subscribers. A total of 1,189 alerts had been transmitted through 2011. More alerts were sent for Florida (134 alerts) than for any other state. Fishes comprise the largest taxonomic group of alerts (440), with mollusks, plants, and crustaceans each containing over 100 alerts. Most alerts were for organisms that were intentionally released (414 alerts), with shipping, escape from captivity, and hitchhiking also representing major vectors. To explore the archive of sent alerts and to register, the search and signup page for the alert system can be found online at http://nas.er.usgs.gov/AlertSystem/default.aspx.

NAS Panel endorses science center concept

NASA Astrophysics Data System (ADS)

Science and technology centers, as proposed by President Ronald Reagan in his January 1987 State of the Union message, could make “significant contributions to science and to the nation's economic competitiveness,” according to a new report by a National Academy of Sciences (NAS) panel. What will be necessary to realize these contributions, the panel cautioned, are proper management, adequate resources, and, “above all, the selection of programs for which the centers are the most effective form of organization.”NSF plans to support science and technology centers, beginning October 1, 1988, which is the start of fiscal year 1988. NSF requested guidance from the NAS panel in implementing the program. Although other government agencies will participate in the program, NSF will play the primary role.

Fast imaging employing steady-state acquisition (FIESTA) MRI to investigate cerebrospinal fluid (CSF) within dural reflections of posterior fossa cranial nerves

PubMed Central

Scoffings, Daniel; Ajithkumar, Thankamma; Williams, Michael V; Jefferies, Sarah J

2016-01-01

Objective: There is no consensus approach to covering skull base meningeal reflections—and cerebrospinal fluid (CSF) therein—of the posterior fossa cranial nerves (CNs VII–XII) when planning radiotherapy (RT) for medulloblastoma and ependymoma. We sought to determine whether MRI and specifically fast imaging employing steady-state acquisition (FIESTA) sequences can answer this anatomical question and guide RT planning. Methods: 96 posterior fossa FIESTA sequences were reviewed. Following exclusions, measurements were made on the following scans for each foramen respectively (left, right); internal acoustic meatus (IAM) (86, 84), jugular foramen (JF) (83, 85) and hypoglossal canal (HC) (42, 45). A protocol describes measurement procedure. Two observers measured distances for five cases and agreement was assessed. One observer measured all the remaining cases. Results: IAM and JF measurement interobserver variability was compared. Mean measurement difference between observers was −0.275 mm (standard deviation 0.557). IAM and JF measurements were normally distributed. Mean IAM distance was 12.2 mm [95% confidence interval (CI) 8.8–15.6]; JF was 7.3 mm (95% CI 4.0–10.6). The HC was difficult to visualize on many images and data followed a bimodal distribution. Conclusion: Dural reflections of posterior fossa CNs are well demonstrated by FIESTA MRI. Measuring CSF extension into these structures is feasible and robust; mean CSF extension into IAM and JF was measured. We plan further work to assess coverage of these structures with photon and proton RT plans. Advances in knowledge: We have described CSF extension beyond the internal table of the skull into the IAM, JF and HC. Oncologists planning RT for patients with medulloblastoma and ependymoma may use these data to guide contouring. PMID:27636022

Computational Investigation of Cerebrospinal Fluid Dynamics in the Posterior Cranial Fossa and Cervical Subarachnoid Space in Patients with Chiari I Malformation.

PubMed

Støverud, Karen-Helene; Langtangen, Hans Petter; Ringstad, Geir Andre; Eide, Per Kristian; Mardal, Kent-Andre

2016-01-01

Previous computational fluid dynamics (CFD) studies have demonstrated that the Chiari malformation is associated with abnormal cerebrospinal fluid (CSF) flow in the cervical part of the subarachnoid space (SAS), but the flow in the SAS of the posterior cranial fossa has received little attention. This study extends previous modelling efforts by including the cerebellomedullary cistern, pontine cistern, and 4th ventricle in addition to the cervical subarachnoid space. The study included one healthy control, Con1, and two patients with Chiari I malformation, P1 and P2. Meshes were constructed by segmenting images obtained from T2-weighted turbo spin-echo sequences. CFD simulations were performed with a previously verified and validated code. Patient-specific flow conditions in the aqueduct and the cervical SAS were used. Two patients with the Chiari malformation and one control were modelled. The results demonstrated increased maximal flow velocities in the Chiari patients, ranging from factor 5 in P1 to 14.8 in P2, when compared to Con1 at the level of Foramen Magnum (FM). Maximal velocities in the cervical SAS varied by a factor 2.3, while the maximal flow in the aqueduct varied by a factor 3.5. The pressure drop from the pontine cistern to the cervical SAS was similar in Con1 and P1, but a factor two higher in P2. The pressure drop between the aqueduct and the cervical SAS varied by a factor 9.4 where P1 was the one with the lowest pressure jump and P2 and Con1 differed only by a factor 1.6. This pilot study demonstrates that including the posterior cranial fossa is feasible and suggests that previously found flow differences between Chiari I patients and healthy individuals in the cervical SAS may be present also in the SAS of the posterior cranial fossa.

UAS-NAS Flight Test Series 3: Test Environment Report

NASA Technical Reports Server (NTRS)

Hoang, Ty; Murphy, Jim; Otto, Neil

2016-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communications (Comm), and Certification to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Detect and Avoid (DAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project is conducting a series of human-in-the-loop (HITL) and flight test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity, and

The NAS kernel benchmark program

NASA Technical Reports Server (NTRS)

Bailey, D. H.; Barton, J. T.

1985-01-01

A collection of benchmark test kernels that measure supercomputer performance has been developed for the use of the NAS (Numerical Aerodynamic Simulation) program at the NASA Ames Research Center. This benchmark program is described in detail and the specific ground rules are given for running the program as a performance test.

Polygonal ridge networks on Mars: Diversity of morphologies and the special case of the Eastern Medusae Fossae Formation

NASA Astrophysics Data System (ADS)

Kerber, Laura; Dickson, James L.; Head, James W.; Grosfils, Eric B.

2017-01-01

Polygonal ridge networks, also known as boxwork or reticulate ridges, are found in numerous locations and geological contexts across Mars. Distinguishing the morphologies and geological context of the ridge networks sheds light on their potential as astrobiological and mineral resource sites of interest. The most widespread type of ridge morphology is characteristic of the Nili Fossae and Nilosyrtis region and consists of thin, criss-crossing ridges with a variety of heights, widths, and intersection angles. They are found in ancient Noachian terrains at a variety of altitudes (between -2500 and 2200 m) and geographic locations and are likely to be chemically altered fracture planes or mineral veins. They occur in the same general areas as valley networks and ancient lake basins, but they are not more numerous where these water-related features are concentrated, and can appear in places where th morphologies are absent. Similarly, some of the ridge networks are located near hydrated mineral detections, but there is not a one-to-one correlation. Smaller, light-toned ridges of variable widths have been found in Gale Crater and other rover sites and are interpreted to be smaller versions of the Nili-like ridges, mostly formed by the mineralization of fractures. This type of ridge is likely to be found in many other places on Mars as more high-resolution data become available. Sinus Meridiani contains many flat-topped ridges arranged into quasi-circular patterns. The ridges are eroding from a clay-rich unit, and could be formed by a similar process as the Nili-type ridges, but at a much larger scale and controlled by fractures made through a different process. Hellas Basin is host to a fourth type of ridge morphology consisting of large, thick, light-toned ridges forming regular polygons at several superimposed scales. While still enigmatic, these are most likely to be the result of sediment-filled fractures. The Eastern Medusae Fossae Formation contains large swaths

National Air Space (NAS) Data Exchange Environment Through 2060

NASA Technical Reports Server (NTRS)

Roy, Aloke

2015-01-01

NASA's NextGen Concepts and Technology Development (CTD) Project focuses on capabilities to improve safety, capacity and efficiency of the National Air Space (NAS). In order to achieve those objectives, NASA sought industry-Government partnerships to research and identify solutions for traffic flow management, dynamic airspace configuration, separation assurance, super density operations, airport surface operations and similar forward-looking air-traffic modernization (ATM) concepts. Data exchanges over NAS being the key enabler for most of these ATM concepts, the Sub-Topic area 3 of the CTD project sought to identify technology candidates that can satisfy air-to-air and air/ground communications needs of the NAS in the year 2060 timeframe. Honeywell, under a two-year contract with NASA, is working on this communications technology research initiative. This report summarizes Honeywell's research conducted during the second year of the study task.

NAS Technical Summaries, March 1993 - February 1994

NASA Technical Reports Server (NTRS)

1995-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1993-94 operational year concluded with 448 high-speed processor projects and 95 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

Cholecystokinin-Assisted Hydrodissection of the Gallbladder Fossa during FDG PET/CT-guided Liver Ablation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tewari, Sanjit O., E-mail: tewaris@mskcc.org; Petre, Elena N., E-mail: petree@mskcc.org; Osborne, Joseph, E-mail: osbornej@mskcc.org

2013-12-15

A 68-year-old female with colorectal cancer developed a metachronous isolated fluorodeoxyglucose-avid (FDG-avid) segment 5/6 gallbladder fossa hepatic lesion and was referred for percutaneous ablation. Pre-procedure computed tomography (CT) images demonstrated a distended gallbladder abutting the segment 5/6 hepatic metastasis. In order to perform ablation with clear margins and avoid direct puncture and aspiration of the gallbladder, cholecystokinin was administered intravenously to stimulate gallbladder contraction before hydrodissection. Subsequently, the lesion was ablated successfully with sufficient margins, of greater than 1.0 cm, using microwave with ultrasound and FDG PET/CT guidance. The patient tolerated the procedure very well and was discharged home themore » next day.« less

UAS-NAS Integrated Human in the Loop: Test Environment Report

NASA Technical Reports Server (NTRS)

Murphy, Jim; Otto, Neil; Jovic, Srba

2015-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research was broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of the Test Infrastructure theme was to enable development and validation of airspace integration procedures and performance standards, including the execution of integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project developed an adaptable, scalable, and schedulable relevant test environment incorporating live, virtual, and constructive elements capable of validating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project planned to conduct three integrated events: a Human-in-the-Loop simulation and two Flight Test series that integrated key concepts, technologies and/or procedures in a relevant air traffic environment. Each of

High-resolution STIR for 3-T MRI of the posterior fossa: visualization of the lower cranial nerves and arteriovenous structures related to neurovascular compression.

PubMed

Hiwatashi, Akio; Yoshiura, Takashi; Yamashita, Koji; Kamano, Hironori; Honda, Hiroshi

2012-09-01

Preoperative evaluation of small vessels without contrast material is sometimes difficult in patients with neurovascular compression disease. The purpose of this retrospective study was to evaluate whether 3D STIR MRI could simultaneously depict the lower cranial nerves--fifth through twelfth--and the blood vessels in the posterior fossa. The posterior fossae of 47 adults (26 women, 21 men) without gross pathologic changes were imaged with 3D STIR and turbo spin-echo heavily T2-weighted MRI sequences and with contrast-enhanced turbo field-echo MR angiography (MRA). Visualization of the cranial nerves on STIR images was graded on a 4-point scale and compared with visualization on T2-weighted images. Visualization of the arteries on STIR images was evaluated according to the segments in each artery and compared with that on MRA images. Visualization of the veins on STIR images was also compared with that on MRA images. Statistical analysis was performed with the Mann-Whitney U test. There were no significant differences between STIR and T2-weighted images with respect to visualization of the cranial nerves (p > 0.05). Identified on STIR and MRA images were 94 superior cerebellar arteries, 81 anteroinferior cerebellar arteries, and 79 posteroinferior cerebellar arteries. All veins evaluated were seen on STIR and MRA images. There were no significant differences between STIR and MRA images with respect to visualization of arteries and veins (p > 0.05). High-resolution STIR is a feasible method for simultaneous evaluation of the lower cranial nerves and the vessels in the posterior fossa without the use of contrast material.

Hybrid Network Architectures for the Next Generation NAS

NASA Technical Reports Server (NTRS)

Madubata, Christian

2003-01-01

To meet the needs of the 21st Century NAS, an integrated, network-centric infrastructure is essential that is characterized by secure, high bandwidth, digital communication systems that support precision navigation capable of reducing position errors for all aircraft to within a few meters. This system will also require precision surveillance systems capable of accurately locating all aircraft, and automatically detecting any deviations from an approved path within seconds and be able to deliver high resolution weather forecasts - critical to create 4- dimensional (space and time) profiles for up to 6 hours for all atmospheric conditions affecting aviation, including wake vortices. The 21st Century NAS will be characterized by highly accurate digital data bases depicting terrain, obstacle, and airport information no matter what visibility conditions exist. This research task will be to perform a high-level requirements analysis of the applications, information and services required by the next generation National Airspace System. The investigation and analysis is expected to lead to the development and design of several national network-centric communications architectures that would be capable of supporting the Next Generation NAS.

SMART NAS Test Bed Overview

NASA Technical Reports Server (NTRS)

Palopo, Kee

2016-01-01

These slides presents an overview of SMART NAS Test Bed. The test bed is envisioned to be connected to operational systems and to allow a new concept and technology to be evaluated in its realistic environment. Its role as an accelerator of concepts and technologies development, its use-case-driven development approach, and its state are presented.

NAS Applications and Advanced Algorithms

NASA Technical Reports Server (NTRS)

Bailey, David H.; Biswas, Rupak; VanDerWijngaart, Rob; Kutler, Paul (Technical Monitor)

1997-01-01

This paper examines the applications most commonly run on the supercomputers at the Numerical Aerospace Simulation (NAS) facility. It analyzes the extent to which such applications are fundamentally oriented to vector computers, and whether or not they can be efficiently implemented on hierarchical memory machines, such as systems with cache memories and highly parallel, distributed memory systems.

[Extended endoscopic endonasal posterior (transclival) approach to tumors of the clival region and ventral posterior cranial fossa. Part 1. Topographic and anatomical features of the clivus and adjacent structures].

PubMed

Shkarubo, A N; Koval', K V; Dobrovol'skiy, G F; Shkarubo, M A; Karnaukhov, V V; Kadashev, B A; Andreev, D N; Chernov, I V; Gadzhieva, O A; Aleshkina, O Yu; Anisimova, E A; Kalinin, P L; Kutin, M A; Fomichev, D V; Sharipov, O I; Ismailov, D B; Selivanov, E S

to describe the main topographic and anatomical features of the clival region and its adjacent structures for improvement and optimization of the extended endoscopic endonasal posterior (transclival) approach for resection of tumors of the clival region and ventral posterior cranial fossa. We performed a craniometric study of 125 human skulls and a topographic anatomical study of heads of 25 cadavers, the arterial and venous bed of which was stained with colored silicone (the staining technique was developed by the authors) to visualize bed features and individual variability. Currently, we have clinical material from more than 120 surgical patients with various skull base tumors of the clival region and ventral posterior cranial fossa (chordomas, pituitary adenomas, meningiomas, cholesteatomas, etc.) who were operated on using the endoscopic transclival approach. We present the main anatomical landmarks and parameters of some anatomical structures that are required for performing the endoscopic endonasal posterior approach. The anatomical landmarks, such as the intradural openings of the abducens and glossopharyngeal nerves, may be used to arbitrarily divide the clival region into the superior, middle, and inferior thirds. The anatomical landmarks important for the surgeon, which are detected during a topographic anatomical study of the skull base, facilitate identification of the boundaries between the different clival portions and the C1 segments of the internal carotid arteries. The superior, middle, and inferior transclival approaches provide an access to the ventral surface of the upper, middle, and lower neurovascular complexes in the posterior cranial fossa. The endoscopic transclival approach may be used to access midline tumors of the posterior cranial fossa. The approach is an alternative to transcranial approaches in surgical treatment of clival region lesions. This approach provides results comparable (and sometimes better) to those of the transcranial

Emergency department CT screening of patients with nontraumatic neurological symptoms referred to the posterior fossa: comparison of thin versus thick slice images.

PubMed

Kamalian, Shervin; Atkinson, Wendy L; Florin, Lauren A; Pomerantz, Stuart R; Lev, Michael H; Romero, Javier M

2014-06-01

Evaluation of the posterior fossa (PF) on 5-mm-thick helical CT images (current default) has improved diagnostic accuracy compared to 5-mm sequential CT images; however, 5-mm-thick images may not be ideal for PF pathology due to volume averaging of rapid changes in anatomy in the Z-direction. Therefore, we sought to determine if routine review of 1.25-mm-thin helical CT images has superior accuracy in screening for nontraumatic PF pathology. MRI proof of diagnosis was obtained within 6 h of helical CT acquisition for 90 consecutive ED patients with, and 88 without, posterior fossa lesions. Helical CT images were post-processed at 1.25 and 5-mm-axial slice thickness. Two neuroradiologists blinded to the clinical/MRI findings reviewed both image sets. Interobserver agreement and accuracy were rated using Kappa statistics and ROC analysis, respectively. Of the 90/178 (51 %) who were MR positive, 60/90 (66 %) had stroke and 30/90 (33 %) had other etiologies. There was excellent interobserver agreement (κ > 0.97) for both thick and thin slice assessments. The accuracy, sensitivity, and specificity for 1.25-mm images were 65, 44, and 84 %, respectively, and for 5-mm images were 67, 45, and 85 %, respectively. The diagnostic accuracy was not significantly different (p > 0.5). In this cohort of patients with nontraumatic neurological symptoms referred to the posterior fossa, 1.25-mm-thin slice CT reformatted images do not have superior accuracy compared to 5-mm-thick images. This information has implications on optimizing resource utilizations and efficiency in a busy emergency room. Review of 1.25-mm-thin images may help diagnostic accuracy only when review of 5-mm-thick images as current default is inconclusive.

NASA Advanced Supercomputing (NAS) User Services Group

NASA Technical Reports Server (NTRS)

Pandori, John; Hamilton, Chris; Niggley, C. E.; Parks, John W. (Technical Monitor)

2002-01-01

This viewgraph presentation provides an overview of NAS (NASA Advanced Supercomputing), its goals, and its mainframe computer assets. Also covered are its functions, including systems monitoring and technical support.

Superolateral dislocation of an intact mandibular condyle into the temporal fossa: case report and literature review.

PubMed

Sharma, Divashree; Khasgiwala, Ankit; Maheshwari, Bharat; Singh, Charanpreet; Shakya, Neelam

2017-02-01

Temporomandibular joint dislocation refers to the dislodgement of mandibular condyle from the glenoid fossa. Anterior and anteromedial dislocations of the mandibular condyle are frequently reported in the literature, but superolateral dislocation is a rare presentation. This report outlines a case of superolateral dislocation of an intact mandibular condyle that occurred in conjunction with an ipsilateral mandibular parasymphysis fracture. A review of the clinical features of superolateral dislocation of the mandibular condyle and the possible techniques of its reduction ranging from the most conservative means to extensive surgical interventions is presented. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of magnetic resonance imaging and computed tomography in suspected lesions in the posterior cranial fossa.

PubMed Central

Teasdale, G. M.; Hadley, D. M.; Lawrence, A.; Bone, I.; Burton, H.; Grant, R.; Condon, B.; Macpherson, P.; Rowan, J.

1989-01-01

OBJECTIVE--To compare computed tomography and magnetic resonance imaging in investigating patients suspected of having a lesion in the posterior cranial fossa. DESIGN--Randomised allocation of newly referred patients to undergo either computed tomography or magnetic resonance imaging; the alternative investigation was performed subsequently only in response to a request from the referring doctor. SETTING--A regional neuroscience centre serving 2.7 million. PATIENTS--1020 Patients recruited between April 1986 and December 1987, all suspected by neurologists, neurosurgeons, or other specialists of having a lesion in the posterior fossa and referred for neuroradiology. The groups allocated to undergo computed tomography or magnetic resonance imaging were well matched in distributions of age, sex, specialty of referring doctor, investigation as an inpatient or an outpatient, suspected site of lesion, and presumed disease process; the referring doctor's confidence in the initial clinical diagnosis was also similar. INTERVENTIONS--After the patients had been imaged by either computed tomography or magnetic resonance (using a resistive magnet of 0.15 T) doctors were given the radiologist's report and a form asking if they considered that imaging with the alternative technique was necessary and, if so, why; it also asked for their current diagnoses and their confidence in them. MAIN OUTCOME MEASURES--Number of requests for the alternative method of investigation. Assessment of characteristics of patients for whom further imaging was requested and lesions that were suspected initially and how the results of the second imaging affected clinicians' and radiologists' opinions. RESULTS--Ninety three of the 501 patients who initially underwent computed tomography were referred subsequently for magnetic resonance imaging whereas only 28 of the 493 patients who initially underwent magnetic resonance imaging were referred subsequently for computed tomography. Over the study the

Case of a strangulated right paraduodenal fossa hernia in a malrotated gut.

PubMed

Ong, Michelle; Roberts, Matthew; Perera, Marlon; Pretorius, Casper

2017-07-24

We report an unusual case of a strangulated internal hernia resulting from a right paraduodenal fossa hernia (PDH) in the context of bowel malrotation. There are few documented cases of PDHs associated with a concomitant gut malrotation. Emergency laparotomy was performed based on clinical and radiological. Intraoperatively, the proximal jejunum was seen to enter a hernia sac formed by an aberrant duodenojejunal flexure located to the right of the aorta. This was presumed to be a strangulated internal hernia of the paraduodenal recess in a malrotated gut. The hernia neck was widened and the sac obliterated to allow reduction of the contents. On reduction and warming, the insulted small bowel appeared viable and returned to the abdominal cavity without resection. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Corticospinal activation confounds cerebellar effects of posterior fossa stimuli.

PubMed

Fisher, Karen M; Lai, H Ming; Baker, Mark R; Baker, Stuart N

2009-12-01

To investigate the efficacy of magnetic stimulation over the posterior fossa (PF) as a non-invasive assessment of cerebellar function in man. We replicated a previously reported conditioning-test paradigm in 11 healthy subjects. Transcranial magnetic stimulation (TMS) at varying intensities was applied to the PF and motor cortex with a 3, 5 or 7 ms interstimulus interval (ISI), chosen randomly for each trial. Surface electromyogram (EMG) activity was recorded from two intrinsic hand muscles and two forearm muscles. Responses were averaged and rectified, and MEP amplitudes were compared to assess whether suppression of the motor output occurred as a result of the PF conditioning pulse. Cortical MEPs were suppressed following conditioning-test ISIs of 5 or 7 ms. No suppression occurred with an ISI of 3 ms. PF stimuli alone also produced EMG responses, suggesting direct activation of the corticospinal tract (CST). CST collaterals are known to contact cortical inhibitory interneurones; antidromic CST activation could therefore contribute to the observed suppression of cortical MEPs. PF stimulation probably activates multiple pathways; even at low intensities it should not be regarded as a selective assessment of cerebellar function unless stringent controls can confirm the absence of confounding activity in other pathways.

UAS Integration in the NAS: Detect and Avoid

NASA Technical Reports Server (NTRS)

Shively, Jay

2018-01-01

This presentation will cover the structure of the unmanned aircraft systems (UAS) integration into the national airspace system (NAS) project (UAS-NAS Project). The talk also details the motivation of the project to help develop standards for a detect-and-avoid (DAA) system, which is required in order to comply with requirements in manned aviation to see-and-avoid other traffic so as to maintain well clear. The presentation covers accomplishments reached by the project in Phase 1 of the research, and touches on the work to be done in Phase 2. The discussion ends with examples of the display work developed as a result of the Phase 1 research.

A new species of Dermopristis Kearn, Whittington & Evans-Gowing, 2010 (Monogenea: Microbothriidae), with observations on associations between the gut diverticula and reproductive system and on the presence of denticles in the nasal fossae of the host Glaucostegus typus (Bennett) (Elasmobranchii: Rhinobatidae).

PubMed

Whittington, Ian D; Kearn, Graham C

2011-09-01

Dermopristis cairae n. sp. (Monogenea: Microbothriidae) is described from the skin and possibly from the nasal fossae of the giant shovel-nosed ray Glaucostegus typus (Bennett). The new species is distinguished from D. paradoxus Kearn, Whittington & Evans-Gowing, 2010 by its larger size, body shape, lack of transverse ridges on the ventral surface and absence of a seminal receptacle. Extensive short gut branches lie dorsal to the testes and adjacent to the coiled region of the vas deferens and the oötype, possibly reflecting high metabolic demand in these areas. Denticles are present in the lining of the nasal fossae of G. typus, providing a firm substrate for the cement-based attachment of a microbothriid. However, confirmation that D. cairae inhabits the nasal fossae of G. typus is required.

Subtemporal-anterior transtentoral approach to middle cranial fossa microsurgical anatomy.

PubMed

Xu, Zhiming; Wang, Weimin; Zhang, Jingjing; Liu, Wei; Feng, Yugong; Li, Gang

2014-11-01

This study aimed to describe the topography of inferior and external dura mater of the middle cranial fossa through subtemporal-anterior transpetrosal approach and discuss the feasibility of improving the approach. Eight formalin-fixed adult cadaveric heads were studied, with the bones milled away in the lateral triangle region of the petrous bone, Kawase rhombus region, and inner triangle region of the petrous apex. The distances between the targets in these regions, as well as the angles after the dissection of zygomatic arch, were measured, and then the exposed petroclival and retrochiasmatic areas were observed under the microscope. There were significant variations in the distances between targets in the 3 milled regions among the specimens. After the dissection of zygomatic arch, the surgical view got an average increase of 12 degrees. The subtemporal anterior transpetrosal approach, as an improved subtemporal approach, can expose the lesions optimally, causing no injury to the hearing and reducing injuries to temporal lobe. On the other hand, the lateral bone of the petrous parts of the temporal bone is removed so as to improve the view to the retrochiasmatic area and expand the operative field.

Increased condylar growth after experimental relocation of the glenoid fossa.

PubMed

Pirttiniemi, P; Kantomaa, T; Tuominen, M

1993-09-01

Attempts to increase mandibular growth by the stimulation of condylar proliferative activity, either experimentally or with functional appliances in humans, have led to controversial results. The aim of this study was to measure changes in proliferative activity in the mandibular condyle after steady experimental posterior relocation of the glenoid fossa in the rabbit without actively interfering with normal masticatory action. The method differed from most previous experimental procedures, which force the mandible anteriorly to stimulate functional appliance therapy. Twelve 5-day-old rabbits underwent gluing of the interparietal, temporoparietal, and lambdoidal sutures. Three experimental and three control rabbits were injected with tritiated thymidine at 10, 15, 20, and 30 days and were killed after 2 h for histological and autoradiographic examination. The total number of labeled cells in the prechondroblastic layer was higher in the experimental group, the difference being greatest in the 20-day-old rabbits. The highest proliferative activity in the experimental group was found in the area immediately posterior to the articular contact surface. There was a tendency for the cartilage layers to be thicker in the experimental group, especially in the extreme anterior segments of the condyle.

[Methods in neonatal abstinence syndrome (NAS): results of a nationwide survey in Austria].

PubMed

Bauchinger, S; Sapetschnig, I; Danda, M; Sommer, C; Resch, B; Urlesberger, B; Raith, W

2015-08-01

Neonatal abstinence syndrome (NAS) occurs in neonates whose mothers have taken addictive drugs or were under substitution therapy during pregnancy. Incidence numbers of NAS are on the rise globally, even in Austria NAS is not rare anymore. The aim of our survey was to reveal the status quo of dealing with NAS in Austria. A questionnaire was sent to 20 neonatology departments all over Austria, items included questions on scoring, therapy, breast-feeding and follow-up procedures. The response rate was 95%, of which 94.7% had written guidelines concerning NAS. The median number of children being treated per year for NAS was 4. Finnegan scoring system is used in 100% of the responding departments. Morphine is being used most often, in opiate abuse (100%) as well as in multiple substance abuse (44.4%). The most frequent forms of morphine preparation are morphine and diluted tincture of opium. Frequency as well as dosage of medication vary broadly. 61.1% of the departments supported breast-feeding, regulations concerned participation in a substitution programme and general contraindications (HIV, HCV, HBV). Our results revealed that there is a big west-east gradient in patients being treated per year. NAS is not a rare entity anymore in Austria (up to 50 cases per year in Vienna). Our survey showed that most neonatology departments in Austria treat their patients following written guidelines. Although all of them base these guidelines on international recommendations there is no national consensus. © Georg Thieme Verlag KG Stuttgart · New York.

(GaIn)(NAs) growth using di-tertiary-butyl-arsano-amine (DTBAA)

NASA Astrophysics Data System (ADS)

Sterzer, E.; Ringler, B.; Nattermann, L.; Beyer, A.; von Hänisch, C.; Stolz, W.; Volz, K.

2017-06-01

III/V semiconductors containing small amounts of Nitrogen (N) are very interesting for a variety of optoelectronic applications. Unfortunately, the conventionally used N precursor 1,1-dimethylhydrazine (UDMHy) has an extremely low N incorporation efficiency in GaAs when grown using metal organic vapor phase epitaxy. Alloying Ga(NAs) with Indium (In) even leads to an exponential reduction of N incorporation. The huge amount of UDMHy in turn changes drastically the growth conditions. Furthermore, the application of this material is still hampered by the large carbon incorporation, most probably originating from the metal organic precursors. Hence, novel precursors for dilute nitride growth are needed. This paper will show (GaIn)(NAs) growth studies with the novel precursor di-tertiary-butyl-arsano-amine in combination with tri-ethyl-gallium and tri-methyl-indium. We show an extremely high N incorporation efficiency in the In containing (GaIn)(NAs). The (GaIn)(NAs) samples investigated in this study have been examined using high resolution X-Ray diffraction, room temperature photoluminescence and atomic force microscope measurements as well as secondary ion mass spectrometry.

A case of symptomatic mass in the right iliac fossa: a Bermuda Triangle which often lies the right diagnosis.

PubMed

Panarese, Alessandra; Pironi, Daniele; Pontone, Stefano; Vendettuoli, Maurizio; De Cristofaro, Flaminia; Antonelli, Manila; Romani, Annamaria; Filippini, Angelo

2014-02-24

Disease of the iliac fossa can often be accompanied by non-specific symptoms and some of these are exclusively caused by the compression of bulky masses of other neighboring structures. In young women a differential diagnosis is a non trivial task as several possible causes have to be taken into account. Thus, intraligamentary tumors, which are extremely rare finding, are frequently confused with uterus, ovary or intestinal tumors. Even if myomas are the most benign tumors of the female genital tract, broad ligament leiomyomas are an unusual finding in women of reproductive age. These tumors are often asymptomatic until they reach a volume likely to cause symptoms related to the mass pressure. An accurate patient's anamnesis and examination serve as a guide to further examinations. Ultrasound is the first line imaging as it can show ovarian or other pelvic mass and doesn't involve exposure to radiations in young patients, who can be pregnant. We describe the clinical presentation and imaging features of a broad ligament leiomyoma, which presented as an inguinal mass in a patient with a right iliac fossa pain. We also report our diagnostic process performing the differential diagnosis with other potential pathologies of RIF. In these cases, a preoperative disease classification discriminating the benign or malignant tumor nature is closely linked to the proper patient management.

Security Controls Hurt Research, NAS Warns.

ERIC Educational Resources Information Center

Kolata, Gina

1982-01-01

A National Academy of Sciences (NAS) report found no evidence that leaks of technical information from universities or other research centers have damaged national security. However, in areas where control is warranted, decisions should be based on criteria. These criteria and issues related to security control and technological transfer are…

Low temperature grown GaNAsSb: A promising material for photoconductive switch application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, K. H.; Yoon, S. F.; Wicaksono, S.

2013-09-09

We report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of the switch and shortened the carrier lifetime. The switch exhibited a dark resistivity of 10{sup 7} Ω cm, a photo-absorption of up to 2.1 μm, and a carrier lifetime of ∼1.3 ps. These results strongly support the suitability of low temperature grown GaNAsSb in the photoconductivemore » switch application.« less

The Age of the Medusae Fossae Formation

NASA Astrophysics Data System (ADS)

Kerber, L.; Head, J. W.

2008-09-01

Introduction The Medusae Fossae Formation (MFF) is a complicated and discontinuous formation located in the southern parts of Elysium Planitia and Amazonis Planitia (130°-230°E and 12°S-12°N), covering an area of approximately 2.1 x 106 km2 and having an estimated volume of 1.4 x 106 km3 [1]. It is thought to have been deposited during the Amazonian period [2,3]. However, much of the cratering record may have been erased as friable units were eroded and long-buried terrains exhumed [4-6]. The formation is characterized by large accumulations of fine-grained, friable deposits and evidence of large amounts of erosion. There are many theories regarding the emplacement of this formation; recently the literature has focused on three possibilities: ignimbrites, ash fall, and aeolian dust. Some modified and inverted fluvial channels have been found within the deposit [7,8], (Fig. 1), indicating that there was some fluvial activity during or after the emplacement of the MFF. If the MFF is among the youngest surficial deposits on Mars [9], it is implied that meandering, channelized flow must have extended into the Amazonian, a significant constraint when considering the atmospheric evolution of the planet through time. Because of the wide implications that these findings have for the evolution of Mars and the Martian atmosphere, it is instructive to re-examine the evidence for the Amazonian age of the MFF. The initial conclusion comes from two main arguments: the relatively few superposed craters on the unit, and the superposition of the MFF on young lowland lava deposits [1, 9]. Using new high resolution data, we reexamine the relationships both within the MFF and with respect to adjacent units. Cratering Record The cratering record of the MFF and other easily eroded units has often been deemed unreliable [4, 10, 12], but it continues to be cited as evidence for the formation's young age. Throughout the MFF, pedestal craters, inverted craters, and remnant knobs can be

Six Years of Parallel Computing at NAS (1987 - 1993): What Have we Learned?

NASA Technical Reports Server (NTRS)

Simon, Horst D.; Cooper, D. M. (Technical Monitor)

1994-01-01

In the fall of 1987 the age of parallelism at NAS began with the installation of a 32K processor CM-2 from Thinking Machines. In 1987 this was described as an "experiment" in parallel processing. In the six years since, NAS acquired a series of parallel machines, and conducted an active research and development effort focused on the use of highly parallel machines for applications in the computational aerosciences. In this time period parallel processing for scientific applications evolved from a fringe research topic into the one of main activities at NAS. In this presentation I will review the history of parallel computing at NAS in the context of the major progress, which has been made in the field in general. I will attempt to summarize the lessons we have learned so far, and the contributions NAS has made to the state of the art. Based on these insights I will comment on the current state of parallel computing (including the HPCC effort) and try to predict some trends for the next six years.

Unexpected rare complication of the facial paralysis in a patient with an antrochoanal polyp following canine fossa puncture.

PubMed

Kim, Ah-Young; Choi, Myoung Su

2015-05-14

Canine fossa puncture (CFP) combined with endoscopic sinus surgery is a simple and effective method for treating antrochoanal polyps, particularly those that originate in the anterior, inferior or medial aspect of the antrum. Several complications can occur following CFP, including facial paraesthesia and dental numbness. However, facial palsy is extremely rare after CFP. We postulated that a possible mechanism of facial palsy is pressure injury to the soft tissues adjacent to the puncture site, which can damage the buccal branch of the facial nerve during CFP. 2015 BMJ Publishing Group Ltd.

An unusual and spectacular case of spindle cell lipoma of the posterior neck invading the spinal cervical canal and posterior cranial fossa.

PubMed

Petit, Damien; Menei, Philippe; Fournier, Henri-Dominique

2011-11-01

The authors describe the first case of spindle cell lipoma of the posterior neck invading the upper cervical spinal canal and the posterior cranial fossa. Spindle cell lipoma is an extremely rare variant of benign lipoma. It usually occurs as a solitary subcutaneous well-circumscribed lesion in the posterior neck or shoulders of adult men. Local aggressiveness is unusual. This 61-year-old man presented with an increased left cerebellar syndrome and headaches. He also had a posterior neck tumefaction, which had been known about for a long time. Computed tomography and MR imaging studies revealed a voluminous mass extending to the upper cervical canal and posterior cranial fossa and eroding the neighboring bones. The lesion was well delimited, and contrast enhancement was intense and heterogeneous. The tumor, which had initially developed under the muscles of the posterior neck, was totally resected. Histological assessment revealed numerous fat cells with spindle cells secreting collagen. The large size of the tumor and the submuscular location, bone erosion, and compression of the CNS were unusual in this rare subtype of benign adipose tumor. Its presentation could simulate a sarcoma.

Applications Performance on NAS Intel Paragon XP/S - 15#

NASA Technical Reports Server (NTRS)

Saini, Subhash; Simon, Horst D.; Copper, D. M. (Technical Monitor)

1994-01-01

The Numerical Aerodynamic Simulation (NAS) Systems Division received an Intel Touchstone Sigma prototype model Paragon XP/S- 15 in February, 1993. The i860 XP microprocessor with an integrated floating point unit and operating in dual -instruction mode gives peak performance of 75 million floating point operations (NIFLOPS) per second for 64 bit floating point arithmetic. It is used in the Paragon XP/S-15 which has been installed at NAS, NASA Ames Research Center. The NAS Paragon has 208 nodes and its peak performance is 15.6 GFLOPS. Here, we will report on early experience using the Paragon XP/S- 15. We have tested its performance using both kernels and applications of interest to NAS. We have measured the performance of BLAS 1, 2 and 3 both assembly-coded and Fortran coded on NAS Paragon XP/S- 15. Furthermore, we have investigated the performance of a single node one-dimensional FFT, a distributed two-dimensional FFT and a distributed three-dimensional FFT Finally, we measured the performance of NAS Parallel Benchmarks (NPB) on the Paragon and compare it with the performance obtained on other highly parallel machines, such as CM-5, CRAY T3D, IBM SP I, etc. In particular, we investigated the following issues, which can strongly affect the performance of the Paragon: a. Impact of the operating system: Intel currently uses as a default an operating system OSF/1 AD from the Open Software Foundation. The paging of Open Software Foundation (OSF) server at 22 MB to make more memory available for the application degrades the performance. We found that when the limit of 26 NIB per node out of 32 MB available is reached, the application is paged out of main memory using virtual memory. When the application starts paging, the performance is considerably reduced. We found that dynamic memory allocation can help applications performance under certain circumstances. b. Impact of data cache on the i860/XP: We measured the performance of the BLAS both assembly coded and Fortran

Balancing the shortcomings of microscope and endoscope: endoscope-assisted technique in microsurgical removal of recurrent epidermoid cysts in the posterior fossa.

PubMed

Ebner, F H; Roser, F; Thaher, F; Schittenhelm, J; Tatagiba, M

2010-10-01

We report about endoscope-assisted surgery of epidermoid cysts in the posterior fossa focusing on the application of neuro-endoscopy and the clinical outcome in cases of recurrent epidermoid cysts. 25 consecutively operated patients with an epidermoid cyst in the posterior fossa were retrospectively analysed. Surgeries were performed both with an operating microscope (OPMI Pentero or NC 4, Zeiss Company, Oberkochen, Germany) and endoscopic equipment (4 mm rigid endoscopes with 30° and 70° optics; Karl Storz Company, Tuttlingen, Germany) under continuous intraoperative monitoring. Surgical reports and DVD-recordings were evaluated for identification of adhesion areas and surgical details. 7 (28%) of the 25 patients were recurrences of previously operated epidermoid cysts. Mean time to recurrence was 17 years (8-22 years). In 5 cases the endoscope was used as an adjunctive tool for inspection/endoscope-assisted removal of remnants. The effective time of use of the endoscope was limited to the end stage of the procedure, but was very effective. In a modern operative setting and with the necessary surgical experience recurrent epidermoid cysts may be removed with excellent clinical results. The combined use of microscope and endoscope offers relevant advantages in demanding anatomic situations. © Georg Thieme Verlag KG Stuttgart · New York.

Pharmacists' and prescribers' neonatal abstinence syndrome (NAS) prevention behaviors: a preliminary analysis.

PubMed

Hagemeier, Nicholas E; Click, Ivy A; Flippin, Heather; Gilliam, Holly; Ross, Alexandra; Basden, Jeri Ann; Carico, Ronald

2018-02-01

Background Maternal opioid use and neonatal abstinence syndrome (NAS) incidence have increased markedly in the US in recent years. Objectives (1) To assess prescribers' and community pharmacists' guideline-based NAS prevention behaviors; (2) to describe providers' perceptions of contraceptive appropriateness in female patients of childbearing age. Method Cross-sectional study of 100 randomly selected primary care physicians, 100 prescribers authorized to engage in in-office treatment of opioid use disorders with buprenorphine, 100 pain management clinic directors, and 100 community pharmacists in Tennessee (N = 400 providers total) to evaluate self-reported engagement in 15 NAS prevention behaviors and perceived appropriateness of 8 contraceptive methods in opioid using women of childbearing age. Results An overall response rate of 17.5% was obtained. Pain clinic directors reported the most engagement in NAS prevention, engaging 80% or more of female patients of childbearing age prescribed an opioid in 11 prevention behaviors, followed by buprenorphine prescribers (8 behaviors), primary care physicians (5 behaviors), and community pharmacists (2 behaviors). Pain clinic directors, primary care physicians, and community pharmacists perceived oral contraceptive pills and patches to be as appropriate as long-acting, reversible forms of contraception (e.g., implants, injectable depots, intrauterine devices). Conclusion Provider engagement in behaviors that could prevent NAS is variable. Interventions should be implemented that equip providers to engage patients in conversations about long-acting, reversible contraception.

Three-dimensional assessment of mandibular and glenoid fossa changes after bone-anchored Class III intermaxillary traction

PubMed Central

De Clerck, Hugo; Nguyen, Tung; de Paula, Leonardo Koerich; Cevidanes, Lucia

2013-01-01

Introduction Conventional treatment for young Class III patients involves extraoral devices designed to either protract the maxilla or restrain mandibular growth. The use of skeletal anchorage offers a promising alternative to obtain orthopedic results with fewer dental compensations. Our aim was to evaluate 3-dimensional changes in the mandibles and the glenoid fossae of Class III patients treated with bone-anchored maxillary protraction. Methods Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years (mean age, 11.10 ± 1.1 year) were treated with Class III intermaxillary elastics and bilateral miniplates (2 in the infrazygomatic crests of the maxilla and 2 in the anterior mandible). The patients had cone-beam computed tomography images taken before initial loading and at the end of active treatment. Three-dimensional models were generated from these images, registered on the anterior cranial base, and analyzed by using color maps. Results Posterior displacement of the mandible at the end of treatment was observed in all subjects (posterior ramus: mean, 2.74 ± 1.36 mm; condyles: mean, 2.07 ± 1.16 mm; chin: mean, −0.13 ± 2.89 mm). Remodeling of the glenoid fossa at the anterior eminence (mean, 1.38 ± 1.03 mm) and bone resorption at the posterior wall (mean, −1.34 ± 0.6 mm) were observed in most patients. Conclusions This new treatment approach offers a promising alternative to restrain mandibular growth for Class III patients with a component of mandibular prognathism or to compensate for maxillary deficiency in patients with hypoplasia of the midface. Future studies with long-term follow-up and comparisons with facemask and chincup therapies are needed to better understand the treatment effects. PMID:22748987

The NAS parallel benchmarks

NASA Technical Reports Server (NTRS)

Bailey, D. H.; Barszcz, E.; Barton, J. T.; Carter, R. L.; Lasinski, T. A.; Browning, D. S.; Dagum, L.; Fatoohi, R. A.; Frederickson, P. O.; Schreiber, R. S.

1991-01-01

A new set of benchmarks has been developed for the performance evaluation of highly parallel supercomputers in the framework of the NASA Ames Numerical Aerodynamic Simulation (NAS) Program. These consist of five 'parallel kernel' benchmarks and three 'simulated application' benchmarks. Together they mimic the computation and data movement characteristics of large-scale computational fluid dynamics applications. The principal distinguishing feature of these benchmarks is their 'pencil and paper' specification-all details of these benchmarks are specified only algorithmically. In this way many of the difficulties associated with conventional benchmarking approaches on highly parallel systems are avoided.

Looking Backward: Parting Reflections on Higher Education Reform from NAS's Founding President

ERIC Educational Resources Information Center

Balch, Stephen H.

2012-01-01

Twenty-five years at the helm of the National Association of Scholars (NAS) have left the author with vivid memories: of knocks and bruises, peaks of exhilaration and, especially, unforgettable characters. But as for lessons learned, that's a very different story. In this article, the author shares some of the successes that happened in NAS for…

NAS Panel faults export controls

NASA Astrophysics Data System (ADS)

Katzoff, Judith A.

A study prepared by a top-level panel says that current export controls on militarily sensitive U.S. technology may be “overcorrecting” previous weaknesses in that system, resulting in “a complex and confusing control system” that makes it more difficult for U.S. businesses to compete in international markets. Moreover, this control system has “an increasingly corrosive effect” on U.S. relations with allies. The panel recommended that the United States concentrate more effort on bringing about uniformity in the export control policies of countries belonging to the Coordinating Committee on Multilateral Export Controls (CoCom), i.e., most of the member nations in NATO (the North Atlantic Treaty Organization) and Japan.The 21-member panel was appointed by the Committee on Science, Engineering, and Public Policy (COSEPUP), a joint unit of the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the Institute of Medicine (IOM). The panel, composed of administrators, researchers, and former government officials, was chaired by AGU member Lew Allen, Jr., director of the Jet Propulsion Laboratory (Pasadena, Calif.) and former chief of staff of the U.S. Air Force. Their report was supported by NAS funds, by a number of private organizations (including AGU), by the U.S. Departments of Commerce, Defense, Energy, and State, by the National Science Foundation, and by the National Aeronautics and Space Administration.

An improved NAS-RIF algorithm for image restoration

NASA Astrophysics Data System (ADS)

Gao, Weizhe; Zou, Jianhua; Xu, Rong; Liu, Changhai; Li, Hengnian

2016-10-01

Space optical images are inevitably degraded by atmospheric turbulence, error of the optical system and motion. In order to get the true image, a novel nonnegativity and support constants recursive inverse filtering (NAS-RIF) algorithm is proposed to restore the degraded image. Firstly the image noise is weaken by Contourlet denoising algorithm. Secondly, the reliable object support region estimation is used to accelerate the algorithm convergence. We introduce the optimal threshold segmentation technology to improve the object support region. Finally, an object construction limit and the logarithm function are added to enhance algorithm stability. Experimental results demonstrate that, the proposed algorithm can increase the PSNR, and improve the quality of the restored images. The convergence speed of the proposed algorithm is faster than that of the original NAS-RIF algorithm.

Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software

NASA Technical Reports Server (NTRS)

Hunter, George; Boisvert, Benjamin

2013-01-01

This document is the final report for the project entitled "Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software." This report consists of 17 sections which document the results of the several subtasks of this effort. The Probabilistic NAS Platform (PNP) is an air operations simulation platform developed and maintained by the Saab Sensis Corporation. The improvements made to the PNP simulation include the following: an airborne distributed separation assurance capability, a required time of arrival assignment and conformance capability, and a tactical and strategic weather avoidance capability.

Neonatal Abstinence Syndrome (NAS) in Southwestern Border States: Examining Trends, Population Correlates, and Implications for Policy.

PubMed

Hussaini, Khaleel S; Garcia Saavedra, Luigi F

2018-03-23

Introduction Neonatal abstinence syndrome (NAS) is withdrawal syndrome in newborns following birth and is primarily caused by maternal drug use during pregnancy. This study examines trends, population correlates, and policy implications of NAS in two Southwest border states. Materials and Methods A cross-sectional analysis of Hospital Inpatient Discharge Data (HIDD) was utilized to examine the incidence of NAS in the Southwest border states of Arizona (AZ) and New Mexico (NM). All inpatient hospital births in AZ and NM from January 1, 2008 through December 31, 2013 with ICD9-CM codes for NAS (779.5), cocaine (760.72), or narcotics (760.75) were extracted. Results During 2008-2013 there were 1472 NAS cases in AZ and 888 in NM. The overall NAS rate during this period was 2.83 per 1000 births (95% CI 2.68-2.97) in AZ and 5.31 (95% CI 4.96-5.66) in NM. NAS rates increased 157% in AZ and 174% in NM. NAS newborns were more likely to have low birth weight, have respiratory distress, more likely to have feeding difficulties, and more likely to be on state Medicaid insurance. AZ border region (border with Mexico) had NAS rates significantly higher than the state rate (4.06 per 1000 births [95% CI 3.68-4.44] vs. 2.83 [95% CI 2.68-2.97], respectively). In NM, the border region rate (2.09 per 1000 births [95% CI 1.48-2.69]) was significantly lower than the state rate (5.31 [95% CI 4.96-5.66]). Conclusions Despite a dramatic increase in the incidence of NAS in the U.S. and, in particular, the Southwest border states of AZ and NM, there is still scant research on the overall incidence of NAS, its assessment in the southwest border, and associated long-term outcomes. The Healthy Border (HB) 2020 binational initiative of the U.S.-Mexico Border Health Commission is an initiative that addresses several public health priorities that not only include chronic and degenerative diseases, infectious diseases, injury prevention, maternal and child health but also mental health and

NAS Parallel Benchmarks. 2.4

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob; Biegel, Bryan A. (Technical Monitor)

2002-01-01

We describe a new problem size, called Class D, for the NAS Parallel Benchmarks (NPB), whose MPI source code implementation is being released as NPB 2.4. A brief rationale is given for how the new class is derived. We also describe the modifications made to the MPI (Message Passing Interface) implementation to allow the new class to be run on systems with 32-bit integers, and with moderate amounts of memory. Finally, we give the verification values for the new problem size.

A branchial cyst of the pyriform fossa transoral laser resection: a case report.

PubMed

Abdelfattah, Hesham Mostafa; Ahmed, Mohammed Elrabie; Ahmed, Mona El-Rabie; Ahmed, Mohamed Abd El-Kader; Moussa, Abd-Elmateen

2016-02-01

Pyriform sinus malformations represent rare third and fourth branchial anomalies. Fistulae at the latter site were initially described and make up less than 1 % of all brachial anomalies. They may be discovered incidentally, or may present as a neck mass with recurrent infection, dysphagia, or airway compromise, and can be an unusual cause of dysphonia in infant and children. Here, we present a case of third branchial cyst located in pharyngeal wall of the left pyriform sinus which presented with dysphonia since birth in a 6-year-old girl. Transoral CO2 laser excision was carried out successfully with no communicating tract. The patient's dysphonia showed progressive regression at 1-year follow-up. Third branchial cyst in the left pyriform sinus (Bailey's type IV) is an unusual cause of dysphonia in pediatric. Our present case report is the first brachial cyst to be reported in the pyriform fossa and the second branchial anomalies to be excised transorally with CO2 laser.

A new isocentric technique for exact geometric matching in the radiotherapy of the breast and ipsilateral supraclavicular fossa using dual asymmetric jaws.

PubMed

Romeo, Nando

2012-10-01

In some clinical situations breast or chest wall radiotherapy for cancer is given in association with supraclavicular fossa irradiation. Often the treatment is delivered by two tangential fields to the breast or chest wall and an anterior field that irradiates the supraclavicular region. The tissue between the breast or chest wall and the supraclavicular region may be under or overdosed, because of the junction between the two tangential fields and the anterior field. To present a new isocentric technique for exact geometric matching between the two tangential fields and the anterior field. Patients are positioned with both arms raised. Using three-dimensional trigonometry, two half-fields, with isocenter between the breast and the supraclavicular region, are easily matched. The tangential fields have a collimator rotation to protect the lung without additional shielding. The correct gantry, collimator and couch positions are defined for the anterior field to match the tangential fields. A general formula for exact geometric matching in radiotherapy of the breast and supraclavicular fossa is presented. The method does not require additional shielding to eliminate divergence other than the four independent jaws. The result is simple to implement in modern delivery facilities. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Operational implications and proposed infrastructure changes for NAS integration of remotely piloted aircraft (RPA)

DOT National Transportation Integrated Search

2014-12-01

The intent of this report is to provide (1) an initial assessment of National Airspace System (NAS) infrastructure affected by continuing development and deployment of unmanned aircraft systems into the NAS, and (2) a description of process challenge...

UAS in the NAS: Survey Responses by ATC, Manned Aircraft Pilots, and UAS Pilots

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; McAdaragh, Raymon; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

2014-01-01

NASA currently is working with industry and the Federal Aviation Administration (FAA) to establish future requirements for Unmanned Aircraft Systems (UAS) flying in the National Airspace System (NAS). To work these issues NASA has established a multi-center "UAS Integration in the NAS" project. In order to establish Ground Control Station requirements for UAS, the perspective of each of the major players in NAS operations was desired. Three on-line surveys were administered that focused on Air Traffic Controllers (ATC), pilots of manned aircraft, and pilots of UAS. Follow-up telephone interviews were conducted with some survey respondents. The survey questions addressed UAS control, navigation, and communications from the perspective of small and large unmanned aircraft. Questions also addressed issues of UAS equipage, especially with regard to sense and avoid capabilities. From the civilian ATC and military ATC perspectives, of particular interest are how mixed operations (manned / UAS) have worked in the past and the role of aircraft equipage. Knowledge gained from this information is expected to assist the NASA UAS Integration in the NAS project in directing research foci thus assisting the FAA in the development of rules, regulations, and policies related to UAS in the NAS.

UAS in the NAS: Survey Responses by ATC, Manned Aircraft Pilots, and UAS Pilots

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; McAdaragh, Raymon; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

2013-01-01

NASA currently is working with industry and the Federal Aviation Administration (FAA) to establish future requirements for Unmanned Aircraft Systems (UAS) flying in the National Airspace System (NAS). To work these issues NASA has established a multi-center UAS Integration in the NAS project. In order to establish Ground Control Station requirements for UAS, the perspective of each of the major players in NAS operations was desired. Three on-line surveys were administered that focused on Air Traffic Controllers (ATC), pilots of manned aircraft, and pilots of UAS. Follow-up telephone interviews were conducted with some survey respondents. The survey questions addressed UAS control, navigation, and communications from the perspective of small and large unmanned aircraft. Questions also addressed issues of UAS equipage, especially with regard to sense and avoid capabilities. From the ATC and military ATC perspective, of particular interest is how mixed-operations (manned/UAS) have worked in the past and the role of aircraft equipage. Knowledge gained from this information is expected to assist the NASA UAS in the NAS project in directing research foci thus assisting the FAA in the development of rules, regulations, and policies related to UAS in the NAS.

Comparison of Origin 2000 and Origin 3000 Using NAS Parallel Benchmarks

NASA Technical Reports Server (NTRS)

Turney, Raymond D.

2001-01-01

This report describes results of benchmark tests on the Origin 3000 system currently being installed at the NASA Ames National Advanced Supercomputing facility. This machine will ultimately contain 1024 R14K processors. The first part of the system, installed in November, 2000 and named mendel, is an Origin 3000 with 128 R12K processors. For comparison purposes, the tests were also run on lomax, an Origin 2000 with R12K processors. The BT, LU, and SP application benchmarks in the NAS Parallel Benchmark Suite and the kernel benchmark FT were chosen to determine system performance and measure the impact of changes on the machine as it evolves. Having been written to measure performance on Computational Fluid Dynamics applications, these benchmarks are assumed appropriate to represent the NAS workload. Since the NAS runs both message passing (MPI) and shared-memory, compiler directive type codes, both MPI and OpenMP versions of the benchmarks were used. The MPI versions used were the latest official release of the NAS Parallel Benchmarks, version 2.3. The OpenMP versiqns used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN 3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

Stereotactic robot-assisted MRI-guided laser thermal ablation of radiation necrosis in the posterior cranial fossa: technical note.

PubMed

Chan, Alvin Y; Tran, Diem Kieu T; Gill, Amandip S; Hsu, Frank P K; Vadera, Sumeet

2016-10-01

Laser interstitial thermal therapy (LITT) is a minimally invasive procedure used to treat a variety of intracranial lesions. Utilization of robotic assistance with stereotactic procedures has gained attention due to potential for advantages over conventional techniques. The authors report the first case in which robot-assisted MRI-guided LITT was used to treat radiation necrosis in the posterior fossa, specifically within the cerebellar peduncle. The use of a stereotactic robot allowed the surgeon to perform LITT using a trajectory that would be extremely difficult with conventional arc-based techniques. A 60-year-old man presented with facial weakness and brainstem symptoms consistent with radiation necrosis. He had a history of anaplastic astrocytoma that was treated with CyberKnife radiosurgery 1 year prior to presentation, and he did well for 11 months until his symptoms recurred. The location and form of the lesion precluded excision but made the patient a suitable candidate for LITT. The location and configuration of the lesion required a trajectory for LITT that was too low for arc-based stereotactic navigation, and thus the ROSA robot (Medtech) was used. Using preoperative MRI acquisitions, the lesion in the posterior fossa was targeted. Bone fiducials were used to improve accuracy in registration, and the authors obtained an intraoperative CT image that was then fused with the MR image by the ROSA robot. They placed the laser applicator and then ablated the lesion under real-time MR thermometry. There were no complications, and the patient tolerated the procedure well. Postoperative 2-month MRI showed complete resolution of the lesion, and the patient had some improvement in symptoms.

Comparison of Porcine and Bovine Collagen Dural Substitutes in Posterior Fossa Decompression for Chiari I Malformation in Adults.

PubMed

Lee, Christine K; Mokhtari, Tara; Connolly, Ian D; Li, Gordon; Shuer, Lawrence M; Chang, Steven D; Steinberg, Gary K; Hayden Gephart, Melanie

2017-12-01

Posterior fossa decompression surgeries for Chiari malformations are susceptible to postoperative complications such as pseudomeningocele, external cerebrospinal fluid (CSF) leak, and meningitis. Various dural substitutes have been used to improve surgical outcomes. This study examined whether the collagen matrix dural substitute type correlated with the incidence of postoperative complications after posterior fossa decompression in adult patients with Chiari I malformations. A retrospective cohort study was conducted of 81 adult patients who underwent an elective decompressive surgery for treatment of symptomatic Chiari I malformations, with duraplasty involving a dural substitute derived from either bovine or porcine collagen matrix. Demographics and treatment characteristics were correlated with surgical outcomes. A total of 81 patients were included in the study. Compared with bovine dural substitute, porcine dural substitute was associated with a significantly higher risk of pseudomeningocele occurrence (odds ratio, 5.78; 95% confidence interval, 1.65-27.15; P = 0.01) and a higher overall complication rate (odds ratio, 3.70; 95% confidence interval, 1.23-12.71; P = 0.03) by univariate analysis. There was no significant difference in the rate of meningitis, repeat operations, or overall complication rate between the 2 dural substitutes. In addition, estimated blood loss was a significant risk factor for meningitis (P = 0.03). Multivariate analyses again showed that porcine dural substitute was associated with pseudomeningocele occurrence, although the association with higher overall complication rate did not reach significance. Dural substitutes generated from porcine collagen, compared with those from bovine collagen, were associated with a higher likelihood of pseudomeningocele development in adult patients undergoing Chiari I malformation decompression and duraplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

Osteochondrosis, Synovial Fossae, and Articular Indentations in the Talus and Distal Tibia of Growing Domestic Pigs and Wild Boars.

PubMed

Etterlin, P E; Ekman, S; Strand, R; Olstad, K; Ley, C J

2017-05-01

Articular osteochondrosis (OC) often develops in typical locations within joints, and the characterization of OC distribution in the pig tarsus is incomplete. Prevalence of OC is high in domestic pigs but is presumed to be low in wild boars. Postmortem and computed tomography (CT) examinations of the talus and distal tibia from 40 domestic pigs and 39 wild boars were evaluated for the locations and frequencies of OC, synovial fossae, and other articular indentations, and frequency distribution maps were made. All domestic pigs but only 5 wild boars (13%) had OC on the talus. In domestic pigs, OC consistently affected the axial aspect of the medial trochlea tali in 11 (28%) joints and the distomedial talus in 26 (65%) joints. In wild boars, all OC lesions consistently affected the distomedial talus. On the articular surface of the distal tibia, all domestic pigs and 34 wild boars (87%) had synovial fossae and 7 domestic pigs (18%) had superficial cartilage fibrillation opposite an OC lesion (kissing lesion). Other articular indentations occurred in the intertrochlear groove of the talus in all domestic pigs and 13 wild boars (33%) and were less common on the trochlea tali. The prevalence of tarsal OC in wild boars is low. In domestic pigs and wild boars, OC is typically localized to the distomedial talus and in domestic pigs also to the medial trochlea tali. Further investigations into the reasons for the low OC prevalence in wild boars may help in developing strategies to reduce OC incidence in domestic pigs.

Effect of antimony on the deep-level traps in GaInNAsSb thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Islam, Muhammad Monirul, E-mail: islam.monir.ke@u.tsukuba.ac.jp; Miyashita, Naoya; Ahsan, Nazmul

2014-09-15

Admittance spectroscopy has been performed to investigate the effect of antimony (Sb) on GaInNAs material in relation to the deep-level defects in this material. Two electron traps, E1 and E2 at an energy level 0.12 and 0.41 eV below the conduction band (E{sub C}), respectively, were found in undoped GaInNAs. Bias-voltage dependent admittance confirmed that E1 is an interface-type defect being spatially localized at the GaInNAs/GaAs interface, while E2 is a bulk-type defect located around mid-gap of GaInNAs layer. Introduction of Sb improved the material quality which was evident from the reduction of both the interface and bulk-type defects.

NAS Grid Benchmarks: A Tool for Grid Space Exploration

NASA Technical Reports Server (NTRS)

Frumkin, Michael; VanderWijngaart, Rob F.; Biegel, Bryan (Technical Monitor)

2001-01-01

We present an approach for benchmarking services provided by computational Grids. It is based on the NAS Parallel Benchmarks (NPB) and is called NAS Grid Benchmark (NGB) in this paper. We present NGB as a data flow graph encapsulating an instance of an NPB code in each graph node, which communicates with other nodes by sending/receiving initialization data. These nodes may be mapped to the same or different Grid machines. Like NPB, NGB will specify several different classes (problem sizes). NGB also specifies the generic Grid services sufficient for running the bench-mark. The implementor has the freedom to choose any specific Grid environment. However, we describe a reference implementation in Java, and present some scenarios for using NGB.

Examination of Frameworks for Safe Integration of Intelligent Small UAS into the NAS

NASA Technical Reports Server (NTRS)

Logan, Michael J.

2012-01-01

This paper discusses a proposed framework for the safe integration of small unmanned aerial systems (sUAS) into the National Airspace System (NAS). The paper briefly examines the potential uses of sUAS to build an understanding of the location and frequency of potential future flight operations based on the future applications of the sUAS systems. The paper then examines the types of systems that would be required to meet the application-level demand to determine "classes" of platforms and operations. A framework for categorization of the "intelligence" level of the UAS is postulated for purposes of NAS integration. Finally, constraints on the intelligent systems are postulated to ensure their ease of integration into the NAS.

Silent internal sinus of the pyriform fossa: a rare adult manifestation of a branchial anomaly.

PubMed

Lin, Chao-Jung; Lin, Yaoh-Shiang; Kang, Bor-Hwang; Lee, Jin-Chin

2003-03-01

Branchial anomalies present with a wide range of pathologic characteristics, including cysts, fistulas, and sinuses of the head and neck region. Branchial cysts are most commonly diagnosed during the second through fourth decades of life, while branchial sinuses and fistulas are diagnosed almost exclusively in children with infection episodes. Only rarely has an internal sinus of a third or fourth branchial anomaly manifested in adults as a noninfectious swelling in the neck during swallowing. In this report, we describe our experience treating a 21-year-old man with a left-sided swallowing-induced neck protrusion of 10 years' duration. Findings of physical examination, videolaryngoscopy, and a pharyngoesophagogram confirmed the diagnosis of internal sinus of the pyriform fossa, with uncertain origin of a third or fourth branchial anomaly. The patient underwent regular follow-up as an outpatient and experienced no further infectious episodes.

First-principles study on structure stabilities of α-S and Na-S battery systems

NASA Astrophysics Data System (ADS)

Momida, Hiroyoshi; Oguchi, Tamio

2014-03-01

To understand microscopic mechanisms of charge and discharge reactions in Na-S batteries, there has been increasing needs to study fundamental atomic and electronic structures of elemental S as well as that of Na-S phases. The most stable form of S is known to be an orthorhombic α-S crystal at ambient temperature and pressure, and α-S consists of puckered S8 rings which crystallize in space group Fddd . In this study, the crystal structure of α-S is examined by using first-principles calculations with and without the van der Waals interaction corrections of Grimme's method, and results clearly show that the van der Waals interactions between the S8 rings have crucial roles on cohesion of α-S. We also study structure stabilities of Na2S, NaS, NaS2, and Na2S5 phases with reported crystal structures. Using calculated total energies of the crystal structure models, we estimate discharge voltages assuming discharge reactions from 2Na+ xS -->Na2Sx, and discharge reactions in Na/S battery systems are discussed by comparing with experimental results. This work was partially supported by Elements Strategy Initiative for Catalysts and Batteries (ESICB) of Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan.

Complications of the Middle Cranial Fossa Approach for Acoustic Neuroma Removal.

PubMed

Scheich, Matthias; Ginzkey, Christian; Ehrmann Müller, Desiree; Shehata Dieler, Wafaa; Hagen, Rudolf

2017-08-01

To analyze postoperative complications after microsurgery for acoustic neuroma (AN) via the middle fossa approach (MFA). In total, 203 consecutive patients of a tertiary skull base referral center at a university hospital were included in this retrospective chart and database analysis. All patients had undergone primary microsurgery at the Otorhinolaryngology department via MFA between December 2005 and October 2014. Postoperative complications were documented during the inpatient stay and outpatient follow-up. Overall, 41 complications were registered in 35 patients. The most common was cerebrospinal fluid (CSF) leakage in 13% of the patients. Bleeding complications were documented in seven patients: two cerebellar bleedings, one subdural and one epidural hematoma, two hematomas of the skin, and one bleeding through the closed wound. Two patients experienced meningitis and one patient had a transient ischemic attack. Furthermore, three cases of deep vein thrombosis occurred, which led to a lethal pulmonary embolism in one case. One patient sustained temporary palsy of the vocal fold and another reported antibiotic-associated diarrhea. Acoustic neuroma surgery via the MFA can be conducted with low morbidity and mortality. The most common complication is CSF leakage, which can be treated in most cases in a stepwise conservative manner. Severe adverse events that may require revision surgery are very scarce (1%).

Rare Complication in Third Maxillary Molar Extraction: Dislocation in Infratemporal Fossa.

PubMed

Battisti, Andrea; Priore, Paolo; Giovannetti, Filippo; Barbera, Giorgio; D'Alessandro, Francesco; Valentini, Valentino

2017-10-01

Removal of impacted third maxillary molar is frequently carried out without difficulties and low rate of intraoperative complications. The rare and particularly challenger to manage it is the third molar dislocation into the infratemporal fossa (IF). In this clinical report, the authors present their solution to manage and resolve this particular complication. A 28-year-old woman was referred to the emergency rescue unit of the authors' hospital by her dentistry, after the attempt to extract the left impacted maxillary third molar. During the procedure the tooth accidentally dislodged and was lost sight of it. The patient had significant mouth-opening limitation, omolateral mid face swelling and pain. Computer tomography was immediately performed to determine the exact position of the tooth, showing the dental element dislocated into the IF. Considering all of possible complications the best surgical option must guarantee a direct approach and a constant eye contact of the tooth, even in case of further displacement during the procedure, and allow early surgery. The authors used an endoscopic transoral approach through the preexisted access and solved all the issues reducing morbidity. Removing tooth from the IF could be burdened by serious risk of bleeding and/or nerve injury. The endoscopic approach provides direct view of the IF reducing morbidity.

A Percutaneous Transtubular Middle Fossa Approach for Intracanalicular Tumors.

PubMed

Bernardo, Antonio; Evins, Alexander I; Tsiouris, Apostolos J; Stieg, Philip E

2015-07-01

In cases of small intracanalicular tumors (≤ 1.5 cm), the middle fossa approach (MFA) provides the ability for adequate tumor removal with preservation of existing auditory function. Application of a minimally invasive tubular retractor in this approach may help mitigate the risk of postoperative seizures, aphasia, and venous complications by minimizing intraoperative retraction of the temporal lobe. We propose a minimally invasive microscopic and/or endoscopic percutaneous transtubular MFA for the management of intracanalicular tumors. Subtemporal keyhole craniectomies were performed on 5 preserved cadaveric heads (10 sides), with 6 sides previously injected with a synthetic tumor model. A ViewSite Brain Access System tubular retractor (Vycor Medical, Inc., Boca Raton, Florida, USA) was used to provide minimal temporal retraction and protection of the surrounding anatomy. An extradural dissection of the internal auditory canal was performed under microscopic and endoscopic visualization with a minimally invasive surgical drill and tube shaft instruments, the intracanalicular tumors were removed, and degree of resection was assessed. All 10 approaches were completed successfully through the tubular retractor with minimal retraction of the temporal lobe. Excellent visualization of the structures within the internal auditory canal was achieved with both the microscope and 3-dimensional endoscope. On the 6 synthetic intracanalicular tumors resected, 5 gross total (Grade I) and 1 near total (Grade II) resections were achieved. A percutaneous transtubular MFA is a feasible minimally invasive option for resection of small intracanalicular tumors with potential preservation of auditory function, reduced temporal retraction, and enhanced protection of surrounding structures. Copyright © 2015 Elsevier Inc. All rights reserved.

Data communication requirements for the advanced NAS network

NASA Technical Reports Server (NTRS)

Levin, Eugene; Eaton, C. K.; Young, Bruce

1986-01-01

The goal of the Numerical Aerodynamic Simulation (NAS) Program is to provide a powerful computational environment for advanced research and development in aeronautics and related disciplines. The present NAS system consists of a Cray 2 supercomputer connected by a data network to a large mass storage system, to sophisticated local graphics workstations, and by remote communications to researchers throughout the United States. The program plan is to continue acquiring the most powerful supercomputers as they become available. In the 1987/1988 time period it is anticipated that a computer with 4 times the processing speed of a Cray 2 will be obtained and by 1990 an additional supercomputer with 16 times the speed of the Cray 2. The implications of this 20-fold increase in processing power on the data communications requirements are described. The analysis was based on models of the projected workload and system architecture. The results are presented together with the estimates of their sensitivity to assumptions inherent in the models.

Efficacy of Posterior Fossa Decompression with Duraplasty for Patients with Chiari Malformation Type I: A Systematic Review and Meta-Analysis.

PubMed

Chai, Zhi; Xue, Xiaoming; Fan, Huijie; Sun, Lin; Cai, Hongyu; Ma, Yanmiao; Ma, Cungen; Zhou, Ran

2018-05-01

To quantitatively assess and compare the effectiveness and safety of posterior fossa decompression with duraplasty (PFDD) and posterior fossa decompression (PFD) in treating patients with Chiari malformation type I. PubMed, Embase, and Cochrane Library were searched through May 2017. Fourteen cohort studies comprising 3666 patients with Chiari malformation type I were included. Studies were pooled, and the relative risk (RR) and corresponding 95% confidence interval (CI) were calculated. The decrease in syringomyelia was better in patients in the PFDD group than in patients in the PFD group (RR = 1.57, 95% CI = 1.07-2.32, P heterogeneity  = 0.042, I 2  = 56.6%). The incidence of cerebrospinal fluid leak (RR = 5.23, 95% CI = 2.61-10.51, P heterogeneity  = 0.830, I 2  = 0%) and aseptic meningitis (RR = 4.02, 95% CI = 1.46-11.03, P heterogeneity  = 0.960, I 2  = 0%) significantly increased among patients in the PFDD group compared with patients in the PFD group. When stratifying by age, a significantly reduced risk in the reoperation rate was observed in the adult group. However, the clinical improvement and the incidence of wound infection were not significantly different between the 2 groups. This study confirmed that the decrease in syringomyelia was better for patients treated with PFDD than for patients treated with PFD alone. However, no significant difference was found in the clinical improvement and the reoperation rate between the 2 groups. Copyright © 2018 Elsevier Inc. All rights reserved.

Standard deviation analysis of the mastoid fossa temperature differential reading: a potential model for objective chiropractic assessment.

PubMed

Hart, John

2011-03-01

This study describes a model for statistically analyzing follow-up numeric-based chiropractic spinal assessments for an individual patient based on his or her own baseline. Ten mastoid fossa temperature differential readings (MFTD) obtained from a chiropractic patient were used in the study. The first eight readings served as baseline and were compared to post-adjustment readings. One of the two post-adjustment MFTD readings fell outside two standard deviations of the baseline mean and therefore theoretically represents improvement according to pattern analysis theory. This study showed how standard deviation analysis may be used to identify future outliers for an individual patient based on his or her own baseline data. Copyright © 2011 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Pediatric Chiari malformation type I: long-term outcomes following small-bone-window posterior fossa decompression with autologous-fascia duraplasty

PubMed Central

Liu, Hai; Yang, Chenlong; Yang, Jun; Xu, Yulun

2017-01-01

Chiari malformation type I (CM-I) is a common hindbrain disorder that is associated with deformity and elongation of the cerebellar tonsils. Although CM-I occurs in both pediatric and adult patients, its prevalence, clinical features and management in the pediatric population are not well defined. The current study evaluated a consecutive case series of 92 children (38 females and 54 males) who were diagnosed with congenital CM-I. All patients underwent small-bone-window posterior fossa decompression with autologous-fascia duraplasty. Clinical and radiological features were analyzed and long-term follow-up data were recorded. Risk factors associated with clinical outcomes were investigated using comprehensive statistical methods. Out of the 92 children, 11 (12.0%) were asymptomatic. Associated ventricular dilation was observed in 24 children (26.1%) and concomitant syringomyelia was observed in 72 children (78.3%). A total of 44 children (47.8%) showed scoliosis on plain films. Follow-up data (mean duration, 88.6 months) were available for all patients. Syringomyelia was absent or markedly reduced in 56 patients (77.8%). Symptoms were alleviated in 66 patients, remained unchanged in 12 patients and progressed in 3 patients. Statistical analysis indicated that the cerebellar tonsillar descent (CTD) grade, basilar invagination and platybasia influenced the clinical outcome (P<0.05). In conclusion, early recognition and surgical treatment of CM-I in pediatric patients can lead to good outcomes. The current results suggested that small-bone-window posterior fossa decompression with autologous-fascia duraplasty was an effective safe treatment option with a low complication rate. High CTD grade, basilar invagination and platybasia were indicated to be predictors of poor clinical prognosis. PMID:29285106

Ubiquity and Diversity of Heterotrophic Bacterial nasA Genes in Diverse Marine Environments

PubMed Central

Jiang, Xuexia; Dang, Hongyue; Jiao, Nianzhi

2015-01-01

Nitrate uptake by heterotrophic bacteria plays an important role in marine N cycling. However, few studies have investigated the diversity of environmental nitrate assimilating bacteria (NAB). In this study, the diversity and biogeographical distribution of NAB in several global oceans and particularly in the western Pacific marginal seas were investigated using both cultivation and culture-independent molecular approaches. Phylogenetic analyses based on 16S rRNA and nasA (encoding the large subunit of the assimilatory nitrate reductase) gene sequences indicated that the cultivable NAB in South China Sea belonged to the α-Proteobacteria, γ-Proteobacteria and CFB (Cytophaga-Flavobacteria-Bacteroides) bacterial groups. In all the environmental samples of the present study, α-Proteobacteria, γ-Proteobacteria and Bacteroidetes were found to be the dominant nasA-harboring bacteria. Almost all of the α-Proteobacteria OTUs were classified into three Roseobacter-like groups (I to III). Clone library analysis revealed previously underestimated nasA diversity; e.g. the nasA gene sequences affiliated with β-Proteobacteria, ε-Proteobacteria and Lentisphaerae were observed in the field investigation for the first time, to the best of our knowledge. The geographical and vertical distributions of seawater nasA-harboring bacteria indicated that NAB were highly diverse and ubiquitously distributed in the studied marginal seas and world oceans. Niche adaptation and separation and/or limited dispersal might mediate the NAB composition and community structure in different water bodies. In the shallow-water Kueishantao hydrothermal vent environment, chemolithoautotrophic sulfur-oxidizing bacteria were the primary NAB, indicating a unique nitrate-assimilating community in this extreme environment. In the coastal water of the East China Sea, the relative abundance of Alteromonas and Roseobacter-like nasA gene sequences responded closely to algal blooms, indicating that NAB may be

The dysraphic state of the posterior fossa. Clinical review of the Dandy-Walker syndrome and the so-called arachnoid cysts.

PubMed

Carteri, A; Gerosa, M; Gaini, S M; Villani, R

1979-01-01

The Authors report their case material concerning some basic items of the dysraphic pathology of the Posterior Fossa: 22 cases of Dandy Walker syndromes (DWS) and "Arachnoid Cysts" (PFC). The mean clinical findings (predominant involvement of the vestibular structures of the brain stem in the DWS, frequent epileptic seizures and some cases of hypothalamic disturbances in the PFC) are discussed in the light of current embryological theories on Weed's "area membranacea". Finally the results of differential surgical treatments are examined: good or satisfactory results were obtained with shunts, while still debatable seems to be the direct surgical approach.

Autotasked Performance in the NAS Workload: A Statistical Analysis

NASA Technical Reports Server (NTRS)

Carter, R. L.; Stockdale, I. E.; Kutler, Paul (Technical Monitor)

1998-01-01

A statistical analysis of the workload performance of a production quality FORTRAN code for five different Cray Y-MP hardware and system software configurations is performed. The analysis was based on an experimental procedure that was designed to minimize correlations between the number of requested CPUs and the time of day the runs were initiated. Observed autotasking over heads were significantly larger for the set of jobs that requested the maximum number of CPUs. Speedups for UNICOS 6 releases show consistent wall clock speedups in the workload of around 2. which is quite good. The observed speed ups were very similar for the set of jobs that requested 8 CPUs and the set that requested 4 CPUs. The original NAS algorithm for determining charges to the user discourages autotasking in the workload. A new charging algorithm to be applied to jobs run in the NQS multitasking queues also discourages NAS users from using auto tasking. The new algorithm favors jobs requesting 8 CPUs over those that request less, although the jobs requesting 8 CPUs experienced significantly higher over head and presumably degraded system throughput. A charging algorithm is presented that has the following desirable characteristics when applied to the data: higher overhead jobs requesting 8 CPUs are penalized when compared to moderate overhead jobs requesting 4 CPUs, thereby providing a charging incentive to NAS users to use autotasking in a manner that provides them with significantly improved turnaround while also maintaining system throughput.

UAS Integration in the NAS FY15 Annual Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Randall, Debra; Hackenburg, Davis

2015-01-01

This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS progress and future directions.

Nas transgenic mouse line allows visualization of Notch pathway activity in vivo

PubMed Central

Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

2006-01-01

The Notch signalling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular the precise mapping of its sites of activity, remain unclear. To address this issue, we have generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jκ binding sites. Here we show that this transgenic line, we named NAS for Notch Activity Sensor, displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jκ deficient background indicating that it indeed requires Notch/RBP-Jκ signalling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signalling pathway. PMID:16708386

Investigations of the Optical Properties of GaNAs Alloys by First-Principle.

PubMed

Borovac, Damir; Tan, Chee-Keong; Tansu, Nelson

2017-12-11

We present a Density Functional Theory (DFT) analysis of the optical properties of dilute-As GaN 1-x As x alloys with arsenic (As) content ranging from 0% up to 12.5%. The real and imaginary parts of the dielectric function are investigated, and the results are compared to experimental and theoretical values for GaN. The analysis extends to present the complex refractive index and the normal-incidence reflectivity. The refractive index difference between GaN and GaNAs alloys can be engineered to be up to ~0.35 in the visible regime by inserting relatively low amounts of As-content into the GaN system. Thus, the analysis elucidates on the birefringence of the dilute-As GaNAs alloys and comparison to other experimentally characterized III-nitride systems is drawn. Our findings indicate the potential of GaNAs alloys for III-nitride based waveguide and photonic circuit design applications.

Nas transgenic mouse line allows visualization of Notch pathway activity in vivo.

PubMed

Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

2006-06-01

The Notch signaling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular, the precise mapping of its sites of activity, remain unclear. To address this issue, we generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jkappa binding sites. Here we show that this transgenic line, which we termed NAS (for Notch Activity Sensor), displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jkappa-deficient background, indicating that it indeed requires Notch/RBP-Jkappa signaling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signaling pathway.

Padrões de refluxo nas veias safenas em homens com insuficiência venosa crônica

PubMed Central

Engelhorn, Carlos Alberto; Coral, Francisco Eduardo; Soares, Isabela Chaves Monteiro; Corrêa, Gabriel Fernando de Araújo; Ogeda, Jaqueline Pozzolo; Hara, Larissa Yuri; Murasse, Luisa Saemi

2016-01-01

Resumo Contexto A insuficiência venosa crônica (IVCr) é frequente e predomina nas mulheres, mas ainda há poucas informações sobre o refluxo nas veias safenas na população masculina. Objetivos Identificar os diferentes padrões de refluxo nas veias safenas magnas (VSMs) e parvas (VSPs) em homens, correlacionando esses dados com a apresentação clínica conforme a classificação Clínica, Etiológica, Anatômica e Fisiopatológica (CEAP). Métodos Foram avaliados 369 membros inferiores de 207 homens pela ultrassonografia vascular (UV) com diagnóstico clínico de IVCr primária. As variáveis analisadas foram a classificação CEAP, o padrão de refluxo nas VSMs e VSPs e a correlação entre os dois. Resultados Nos 369 membros avaliados, 72,9% das VSMs apresentaram refluxo com predominância do padrão segmentar (33,8%). Nas VSPs, 16% dos membros inferiores analisados apresentaram refluxo, sendo o mais frequente o padrão distal (33,9%). Dos membros classificados como C4, C5 e C6, 100% apresentaram refluxo na VSM com predominância do refluxo proximal (25,64%), e 38,46% apresentaram refluxo na VSP com equivalência entre os padrões distal e proximal (33,3%). Refluxo na junção safeno-femoral (JSF) foi detectado em 7,1% dos membros nas classes C0 e C1, 35,6% nas classes C2 e C3, e 64,1% nas classes C4 a C6. Conclusões O padrão de refluxo segmentar é predominante na VSM, e o padrão de refluxo distal é predominante na VSP. A ocorrência de refluxo na JSF é maior em pacientes com IVCr mais avançada. PMID:29930603

Tantalus Fossae

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 25 June 2002) The Science Tantalus Fossae is a set of long valleys on the eastern side of Alba Patera. These valleys are referred to as grabens and are formed by extension of the crust and faulting. When large amounts of pressure or tension are applied to rocks on timescales that are fast enough that the rock cannot respond by deforming, the rock breaks along faults. In the case of a graben, two parallel faults are formed by extension of the crust and the rock in between the faults drops downward into the space created by the extension. Numerous sets of grabens are visible in this THEMIS image, trending from north-northeast to south-southwest. Because the faults defining the graben are formed parallel to the direction of the applied stress, we know that extensional forces were pulling the crust apart in the west-northwest/east-southeast direction. The large number of grabens around Alba Patera is generally believed to be the result of extensional forces associated with the uplift of Alba Patera. Also visible in this image are a series of linearly aligned pits, called a pit chain. The pits are not the result of impact cratering, but are similar to sinkholes on Earth. Sinkholes are typically formed by the removal of rock (commonly limestone) underground by groundwater -- when enough rock is removed, the overlying rock becomes too heavy to be supported, and it collapses, forming a pit. Unlike sinkholes, however, the pit chains near Alba Patera were likely formed when empty underground lava tubes collapsed, accounting for the presence and alignment of many pits. Numerous channel features are also observed in the image, and follow the local topographic slope, which is downhill to the east-southeast. One of these, a long channel in the center of the image, nicely demonstrates the complex relations possible between geologic features. The geologist's rule of superposition says that a feature on top of (superposing) another feature, or cutting across another

Geologic Mapping of the Medusae Fossae Formation on Mars (MC-8 SE and MC-23 NW) and the Northern Lowlands of Venus (V-16 and V-15)

NASA Technical Reports Server (NTRS)

Zimbelman, J. R.

2008-01-01

This report summarizes the status of a mapping project supported by NASA grant NNX07AP42G, funding for which became available on July 18, focusing on the mapping of the Medusae Fossae Formation (MFF) on Mars. The report also briefly discusses the status of maps of Venus and Ascraeus Mons, begun under previous NASA grants but which are still in progress.

One-dimensional carbon-sulfur composite fibers for Na-S rechargeable batteries operating at room temperature.

PubMed

Hwang, Tae Hoon; Jung, Dae Soo; Kim, Joo-Seong; Kim, Byung Gon; Choi, Jang Wook

2013-09-11

Na-S batteries are one type of molten salt battery and have been used to support stationary energy storage systems for several decades. Despite their successful applications based on long cycle lives and low cost of raw materials, Na-S cells require high temperatures above 300 °C for their operations, limiting their propagation into a wide range of applications. Herein, we demonstrate that Na-S cells with solid state active materials can perform well even at room temperature when sulfur-containing carbon composites generated from a simple thermal reaction were used as sulfur positive electrodes. Furthermore, this structure turned out to be robust during repeated (de)sodiation for ~500 cycles and enabled extraordinarily high rate performance when one-dimensional morphology is adopted using scalable electrospinning processes. The current study suggests that solid-state Na-S cells with appropriate atomic configurations of sulfur active materials could cover diverse battery applications where cost of raw materials is critical.

Object-Oriented Implementation of the NAS Parallel Benchmarks using Charm++

NASA Technical Reports Server (NTRS)

Krishnan, Sanjeev; Bhandarkar, Milind; Kale, Laxmikant V.

1996-01-01

This report describes experiences with implementing the NAS Computational Fluid Dynamics benchmarks using a parallel object-oriented language, Charm++. Our main objective in implementing the NAS CFD kernel benchmarks was to develop a code that could be used to easily experiment with different domain decomposition strategies and dynamic load balancing. We also wished to leverage the object-orientation provided by the Charm++ parallel object-oriented language, to develop reusable abstractions that would simplify the process of developing parallel applications. We first describe the Charm++ parallel programming model and the parallel object array abstraction, then go into detail about each of the Scalar Pentadiagonal (SP) and Lower/Upper Triangular (LU) benchmarks, along with performance results. Finally we conclude with an evaluation of the methodology used.

Thermal analysis of fractures at Cerberus Fossae, Mars: Detection of air convection in the porous debris apron

NASA Astrophysics Data System (ADS)

Antoine, R.; Lopez, T.; Baratoux, D.; Rabinowicz, M.; Kurita, K.

2011-08-01

This study investigates the cause of high nighttime temperatures within Cerberus Fossae, a system of fractures affecting the Central Elysium Planitia. The inner parts (walls and floor) of the fractures are up to 40 K warmer than the surrounding plains. However, several temperature profiles exhibit a local temperature minima occurring in the central part of the fractures. We examined first the influence of cooling efficiency at night in the case of a strong reduction of the sky proportion induced by the fracture's geometry. However, the lack of correlation between temperature and sky proportion, calculated from extracted Mars Orbiter Laser Altimeter (MOLA) profiles argues against this hypothesis. Albedo variations were considered but appear to be limited within the fractures, and are generally not correlated with the temperatures. Variations of the thermal properties of bedrocks exposures, debris aprons and sand dunes inferred from high-resolution images do not either correlate with temperature variations within the fractures. As none of these factors taken alone, or combined, can satisfactorily explain the temperature variations within and near the fracture, we suggest that geothermal heat transported by air convection within the porous debris aprons may contribute to explain high temperatures at night and the local minima on the fracture floor. The conditions for the occurrence of the suggested phenomenon and the consequences on the surface temperature are numerically explored. A conservative geothermal gradient of 20 mW/m 2 was used in the simulations, this value being consistent with either inferred lithosphere elastic thicknesses below the shield volcanoes of the Tharsis dome or values predicted from numerical simulations of the thermal evolution of Mars. The model results indicate that temperature differences of 10-20 K between the central and upper parts of the fracture are explained in the case of high Darcy velocities which require high permeability values

78 FR 12951 - TRICARE; Elimination of the Non-Availability Statement (NAS) Requirement for Non-Emergency...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-26

... There are no anticipated budgetary health care cost increases. Requiring a NAS for a relatively few non... Inpatient Mental Health Care AGENCY: Office of the Secretary, Department of Defense. ACTION: Final rule... inpatient mental health care in order for a TRICARE Standard beneficiary's claim to be paid. Currently, NAS...

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project FY17 Annual Review

NASA Technical Reports Server (NTRS)

Sakahara, Robert; Hackenberg, Davis; Johnson, William

2017-01-01

This presentation was presented to the Integrated Aviation Systems Program at the FY17 Annual Review of the UAS-NAS project. The presentation captures the overview of the work completed by the UAS-NAS project and its subprojects.

Parallelization of NAS Benchmarks for Shared Memory Multiprocessors

NASA Technical Reports Server (NTRS)

Waheed, Abdul; Yan, Jerry C.; Saini, Subhash (Technical Monitor)

1998-01-01

This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platforms is a challenging task. Ideally, a user develops a sequential version of the application, leaving the task of porting to new generations of high performance computing systems to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically and present the results of parallelization to the users. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks.

Quantum dot-like emitters formed due to alloy fluctuations in GaNAs-based nanowires.

NASA Astrophysics Data System (ADS)

Buyanova, Irina; Jansson, M.; Filippov, S.; Stehr, J.; Palisaitis, J.; Persson, P.; Ishikawa, F.; Chen, Weimin

Group III-V semiconductor nanowires with embedded quantum dots (QDs) are currently attracting increasing attention as a highly attractive platform for a variety of advanced applications ranging from third generation photovoltaics to quantum information technologies. In this work, we show that local fluctuations in N composition inside coaxial GaAs/GaNAs nanowires induces three-dimensional confining potentials equivalent to that for QDs thus forming optically active and highly localized states inside the GaNAs shell. Principal quantization axis of these states is concluded to mainly coincide with the nanowire axis, based on the strong polarization of the detected emission orthogonal to the nanowire axis revealed from polarization-resolved micro-photoluminescence studies. This is partly attributed to a predominantly uniaxial tensile strain field in the GaNAs shell caused by lattice mismatch with the GaAs core. GaNAs alloys can, therefore, be used as an active material in hybrid QD-NW structures utilized for fabrication of nanoscale polarized-light sources that are efficient within the near-infrared spectral range. Financial support by the Swedish Energy Agency (Grant # P40119-1) and the Swedish Research Council (Grant # 2015-05532) is greatly appreciated.

Implementation of NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Schultz, Matthew; Jin, Hao-Qiang; Yan, Jerry

2000-01-01

A number of features make Java an attractive but a debatable choice for High Performance Computing (HPC). In order to gauge the applicability of Java to the Computational Fluid Dynamics (CFD) we have implemented NAS Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would move Java closer to Fortran in the competition for CFD applications.

Applications Performance Under MPL and MPI on NAS IBM SP2

NASA Technical Reports Server (NTRS)

Saini, Subhash; Simon, Horst D.; Lasinski, T. A. (Technical Monitor)

1994-01-01

On July 5, 1994, an IBM Scalable POWER parallel System (IBM SP2) with 64 nodes, was installed at the Numerical Aerodynamic Simulation (NAS) Facility Each node of NAS IBM SP2 is a "wide node" consisting of a RISC 6000/590 workstation module with a clock of 66.5 MHz which can perform four floating point operations per clock with a peak performance of 266 Mflop/s. By the end of 1994, 64 nodes of IBM SP2 will be upgraded to 160 nodes with a peak performance of 42.5 Gflop/s. An overview of the IBM SP2 hardware is presented. The basic understanding of architectural details of RS 6000/590 will help application scientists the porting, optimizing, and tuning of codes from other machines such as the CRAY C90 and the Paragon to the NAS SP2. Optimization techniques such as quad-word loading, effective utilization of two floating point units, and data cache optimization of RS 6000/590 is illustrated, with examples giving performance gains at each optimization step. The conversion of codes using Intel's message passing library NX to codes using native Message Passing Library (MPL) and the Message Passing Interface (NMI) library available on the IBM SP2 is illustrated. In particular, we will present the performance of Fast Fourier Transform (FFT) kernel from NAS Parallel Benchmarks (NPB) under MPL and MPI. We have also optimized some of Fortran BLAS 2 and BLAS 3 routines, e.g., the optimized Fortran DAXPY runs at 175 Mflop/s and optimized Fortran DGEMM runs at 230 Mflop/s per node. The performance of the NPB (Class B) on the IBM SP2 is compared with the CRAY C90, Intel Paragon, TMC CM-5E, and the CRAY T3D.

An Integrated Gate Turnaround Management Concept Leveraging Big Data Analytics for NAS Performance Improvements

NASA Technical Reports Server (NTRS)

Chung, William W.; Ingram, Carla D.; Ahlquist, Douglas Kurt; Chachad, Girish H.

2016-01-01

"Gate Turnaround" plays a key role in the National Air Space (NAS) gate-to-gate performance by receiving aircraft when they reach their destination airport, and delivering aircraft into the NAS upon departing from the gate and subsequent takeoff. The time spent at the gate in meeting the planned departure time is influenced by many factors and often with considerable uncertainties. Uncertainties such as weather, early or late arrivals, disembarking and boarding passengers, unloading/reloading cargo, aircraft logistics/maintenance services and ground handling, traffic in ramp and movement areas for taxi-in and taxi-out, and departure queue management for takeoff are likely encountered on the daily basis. The Integrated Gate Turnaround Management (IGTM) concept is leveraging relevant historical data to support optimization of the gate operations, which include arrival, at the gate, departure based on constraints (e.g., available gates at the arrival, ground crew and equipment for the gate turnaround, and over capacity demand upon departure), and collaborative decision-making. The IGTM concept provides effective information services and decision tools to the stakeholders, such as airline dispatchers, gate agents, airport operators, ramp controllers, and air traffic control (ATC) traffic managers and ground controllers to mitigate uncertainties arising from both nominal and off-nominal airport gate operations. IGTM will provide NAS stakeholders customized decision making tools through a User Interface (UI) by leveraging historical data (Big Data), net-enabled Air Traffic Management (ATM) live data, and analytics according to dependencies among NAS parameters for the stakeholders to manage and optimize the NAS performance in the gate turnaround domain. The application will give stakeholders predictable results based on the past and current NAS performance according to selected decision trees through the UI. The predictable results are generated based on analysis of the

Statistical Analysis of NAS Parallel Benchmarks and LINPACK Results

NASA Technical Reports Server (NTRS)

Meuer, Hans-Werner; Simon, Horst D.; Strohmeier, Erich; Lasinski, T. A. (Technical Monitor)

1994-01-01

In the last three years extensive performance data have been reported for parallel machines both based on the NAS Parallel Benchmarks, and on LINPACK. In this study we have used the reported benchmark results and performed a number of statistical experiments using factor, cluster, and regression analyses. In addition to the performance results of LINPACK and the eight NAS parallel benchmarks, we have also included peak performance of the machine, and the LINPACK n and n(sub 1/2) values. Some of the results and observations can be summarized as follows: 1) All benchmarks are strongly correlated with peak performance. 2) LINPACK and EP have each a unique signature. 3) The remaining NPB can grouped into three groups as follows: (CG and IS), (LU and SP), and (MG, FT, and BT). Hence three (or four with EP) benchmarks are sufficient to characterize the overall NPB performance. Our poster presentation will follow a standard poster format, and will present the data of our statistical analysis in detail.

NAS technical summaries. Numerical aerodynamic simulation program, March 1992 - February 1993

NASA Technical Reports Server (NTRS)

1994-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1992-93 operational year concluded with 399 high-speed processor projects and 91 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

NAS technical summaries: Numerical aerodynamic simulation program, March 1991 - February 1992

NASA Technical Reports Server (NTRS)

1992-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefiting other supercomputer centers in Government and industry. This report contains selected scientific results from the 1991-92 NAS Operational Year, March 4, 1991 to March 3, 1992, which is the fifth year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP. The Cray-2, the first generation supercomputer, has four processors, 256 megawords of central memory, and a total sustained speed of 250 million floating point operations per second. The Cray Y-MP, the second generation supercomputer, has eight processors and a total sustained speed of one billion floating point operations per second. Additional memory was installed this year, doubling capacity from 128 to 256 megawords of solid-state storage-device memory. Because of its higher performance, the Cray Y-MP delivered approximately 77 percent of the total number of supercomputer hours used during this year.

Design handbook : energy efficiency and water conservation in NAS facilities

DOT National Transportation Integrated Search

1997-09-30

This handbook was created to provide definitive energy efficiency and water conservation design criteria for the design of NAS facilities. FAA-HDBK-001 provides implementation strategies and tools to comply with E.O. 12902, Energy and Water Conservat...

[Effects of creating a tunnel through intercondylar fossa under arthroscopy for the treatment of complex tears at the medial meniscus posterior horn].

PubMed

Dong, Ling-Dai; Bing, Chang-Jian; Li, Jian-Lin; Cai, Yue

2017-04-25

To discuss the advantages of the arthroscopic treatment for complex tears of the medial meniscus posterior horn by creating a tunnel passageway through the intercondylar fossa. All 127 patients including 24 males and 103 females with complex tears at the medial meniscus posterior horn were reviewed. The age of all patients ranged from 45 to 78 years old, with an average of 67 years old. All 127 patients were treated with partial meniscectomy, in which 112 patients were treated with partial meniscectomy smoothly with three incisions (anterior medial incision, anterior lateral incision, high anterior lateral incision), and 15 patients were treated with four incisions (anterior medial incision, anterior lateral incision, high anterior lateral incision, posterior medial incision). Four aspects were estimated:whether the meniscus posterior horns could be observed totally and conveniently, whether tools could be pushed to target area conveniently, the damage of adjacent cartilages, operation time(the operation time of partial meniscectomy). Posterior horns of all patients were totally and conveniently observed, tools were conveniently pushed to the target area in all cases, and all the cases had no iatrogenic injuries at adjacent cartilages. The operation time of partial meniscectomy at posterior horns with three incisions ranged from 5 to 10 minutes, and it ranged from 10 to 30 minutes with four incisions. It is very convenient and fast of the arthroscopy to treat complex tears of the medial meniscus posterior horn by creating a tunnel through the intercondylor fossa. Iatrogenic injuries of the adjacent cartilages were prevented to the greatest extent.

Benefits of a Unified LaSRS++ Simulation for NAS-Wide and High-Fidelity Modeling

NASA Technical Reports Server (NTRS)

Glaab, Patricia; Madden, Michael

2014-01-01

The LaSRS++ high-fidelity vehicle simulation was extended in 2012 to support a NAS-wide simulation mode. Since the initial proof-of-concept, the LaSRS++ NAS-wide simulation is maturing into a research-ready tool. A primary benefit of this new capability is the consolidation of the two modeling paradigms under a single framework to save cost, facilitate iterative concept testing between the two tools, and to promote communication and model sharing between user communities at Langley. Specific benefits of each type of modeling are discussed along with the expected benefits of the unified framework. Current capability details of the LaSRS++ NAS-wide simulations are provided, including the visualization tool, live data interface, trajectory generators, terminal routing for arrivals and departures, maneuvering, re-routing, navigation, winds, and turbulence. The plan for future development is also described.

UAS Integration in the NAS Project - FY 14 Annual Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Randall, Debra; Hackenberg, Davis

2014-01-01

This briefing gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS Projects progress and future directions.

DOE Radiation Research Program is floundering - NAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lobsenz, G.

1994-04-20

The Energy Department's radiation health effects research program is floundering in a morass of administrative confusion due to an ill-considered 1990 joint management agreement between DOE and the Health and Human Services Department, a National Academy of Sciences panel says. The NAS panel said the [open quotes]administrative difficulties[close quotes] created by the DOE-HHS agreement appear to be [open quotes]stifling creativity and efficiency within DOE's Epidemiology Research Program, delaying the completion and publication of research.[close quotes] The panel also expressed concern that DOE has failed to adequately fund or staff its health research office, and that the department had no mastermore » research plan to identify research needs or set forth uniform, scientifically rigorous data collection procedures. The panel said DOE's lack of commitment was particularly evident in its failure to set up an effective health surveillance program for its nuclear work force. In addition, the panel said DOE had fallen short on promises to create a comprehensive computer bank of health research data that would be continually updated with new information gleaned from an ongoing worker surveillance program. While recommending enhancements, the NAS panel emphasized that DOE's health research program would not be able to function effectively until the department revamped its joint management agreement with HHS.« less

Development of profound Chiari I malformation and cerebellar tissue loss and resolution following shunting of posterior fossa extra-axial cyst. Case report.

PubMed

Khan, Rabia; Oakes, Peter; Tubbs, R Shane; Oakes, W Jerry

2017-01-01

Chiari I malformation can be due to a multitude of etiologies such as craniosynostosis or hydrocephalus. A posterior fossa extra-axial cyst (PFEAC) appears to be an extremely rare cause of this form of hindbrain herniation. Herein, we report a case of PFEAC that presented with no Chiari I malformation and then presented months later with a significant Chiari I malformation. Following shunt placement of a PFEAC, striking reversal of the Chiari malformation as well as reconstitution of the cerebellum was noted. Patients with PFEAC might develop a Chiari I malformation and this might be treated with shunting of the PFEAC alone.

Stability of unsaturated pyroclastic deposits at La Fossa flank (Vulcano Island, Italy): Do soil suction variations establish a link with crater degassing ?

NASA Astrophysics Data System (ADS)

Olivares, L.; Tommasi, P.; Madonia, P.; Moretti, R.

2012-04-01

The stability of steep ( > 40°) slopes in loose or poorly cemented pyroclastic materials mantling some of the Italian mountain areas is guaranteed by the positive effects of matrix suction on shear strength until an increase in saturation (and hence a decrease in suction) occurs. Therefore, unsaturated cohesionless or slightly-bonded pyroclastic steep deposits are relatively stable. Slope instability, initiated by wetting, can occur through different processes, such as vapor condensation and, most typically, rainfall infiltration. The main effect is the decrease in suction up to possible development of positive pore pressures. Here, we examine the peculiar case of a landslide on the flank of the pyroclastic cone of La Fossa volcanic edifice in Vulcano Island (Aeolian Archipelago, Southern Italy). Its initiation is believed to have been influenced by a sharp increase in condensed vapor produced by the degassing of the active volcano. In active volcanoes hydraulic conditions are affected not only by infiltrating rainwater but also by volcanic activity, which produces complex changes in the state variables of pore fluids (i.e. pore fluid pressure). In particular, volcanic activity can modify pore fluid pressure as far as to induce slope instability. At La Fossa crater the phenomenon was evidenced by in situ monitoring of soil suction and soil temperature. In situ observations and measurements indicate that seepage of condensed vapor is appreciable. Simple models based on the geotechnical characterization of pyroclastic materials suggest the hypothesis that variations in suction can be significant to stability of volcano slopes when these are very close to limit conditions and if material hydraulic anisotropy is considered. Noteworthy, at La Fossa at Vulcano Island steam condensation increased and variations of chemical ratios at fumaloles occurred while large slope movements developed on the NE flank of the cone during the most intense well documented volcanic unrest

Lumbar subdural cerebrospinal fluid collection with acute cauda equina syndrome after posterior fossa decompression for Chiari malformation Type I: case report.

PubMed

Darwish, Houssein A; Oldfield, Edward H

2016-09-01

This report describes the circumstances of a patient with a cauda equina syndrome due to the development of a lumbar subdural CSF collection with ventral displacement of the cauda equina shortly following posterior fossa decompression for Chiari malformation Type I (CM-I). This unusual, but clinically significant, complication was successfully treated with percutaneous drainage of the extraarachnoid CSF collection. Although there are a few cases of intracranial subdural hygroma developing after surgery for CM-I, often attributed to a pinhole opening in the arachnoid, as far as the authors can determine, a spinal subdural hygroma associated with surgery for CM-I has not been recognized.

Meeting of Experts on NASA's Unmanned Aircraft System (UAS) Integration in the National Airspace Systems (NAS) Project

NASA Technical Reports Server (NTRS)

Wolfe, Jean; Bauer, Jeff; Bixby, C.J.; Lauderdale, Todd; Shively, Jay; Griner, James; Hayhurst, Kelly

2010-01-01

Topics discussed include: Aeronautics Research Mission Directorate Integrated Systems Research Program (ISRP) and UAS Integration in the NAS Project; UAS Integration into the NAS Project; Separation Assurance and Collision Avoidance; Pilot Aircraft Interface Objectives/Rationale; Communication; Certification; and Integrated Tests and Evaluations.

QNAP 1263U Network Attached Storage (NAS)/ Storage Area Network (SAN) Device Users Guide

DTIC Science & Technology

2016-11-01

standard Ethernet network. Operating either a NAS or SAN is vital for the integrity of the data stored on the drives found in the device. Redundant...speed of the network itself. Many standards are in place for transferring data, including more standard ones such as File Transfer Protocol and Server ...following are the procedures for connecting to the NAS administrative web page: 1) Open a web browser and browse to 192.168.40.8:8080. 2) Enter the

Great Balls of Fire: A probabilistic approach to quantify the hazard related to ballistics - A case study at La Fossa volcano, Vulcano Island, Italy

NASA Astrophysics Data System (ADS)

Biass, Sébastien; Falcone, Jean-Luc; Bonadonna, Costanza; Di Traglia, Federico; Pistolesi, Marco; Rosi, Mauro; Lestuzzi, Pierino

2016-10-01

We present a probabilistic approach to quantify the hazard posed by volcanic ballistic projectiles (VBP) and their potential impact on the built environment. A model named Great Balls of Fire (GBF) is introduced to describe ballistic trajectories of VBPs accounting for a variable drag coefficient and topography. It relies on input parameters easily identifiable in the field and is designed to model large numbers of VBPs stochastically. Associated functions come with the GBF code to post-process model outputs into a comprehensive probabilistic hazard assessment for VBP impacts. Outcomes include probability maps to exceed given thresholds of kinetic energies at impact, hazard curves and probabilistic isoenergy maps. Probabilities are calculated either on equally-sized pixels or zones of interest. The approach is calibrated, validated and applied to La Fossa volcano, Vulcano Island (Italy). We constructed a generic eruption scenario based on stratigraphic studies and numerical inversions of the 1888-1890 long-lasting Vulcanian cycle of La Fossa. Results suggest a ~ 10- 2% probability of occurrence of VBP impacts with kinetic energies ≤ 104 J at the touristic locality of Porto. In parallel, the vulnerability to roof perforation was estimated by combining field observations and published literature, allowing for a first estimate of the potential impact of VBPs during future Vulcanian eruptions. Results indicate a high physical vulnerability to the VBP hazard, and, consequently, half of the building stock having a ≥ 2.5 × 10- 3% probability of roof perforation.

Implementation of the NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Frumkin, Michael A.; Schultz, Matthew; Jin, Haoqiang; Yan, Jerry; Biegel, Bryan (Technical Monitor)

2002-01-01

Several features make Java an attractive choice for High Performance Computing (HPC). In order to gauge the applicability of Java to Computational Fluid Dynamics (CFD), we have implemented the NAS (NASA Advanced Supercomputing) Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would position Java closer to Fortran in the competition for CFD applications.

Endoscopic endonasal approach to the anteromedial temporal fossa and mobilization of the lateral wall of the cavernous sinus through the inferior orbital fissure and V1-V2 corridor: An anatomical study and clinical considerations.

PubMed

Hanakita, Shunya; Chang, Wei-Chieh; Watanabe, Kentaro; Ronconi, Daniel; Labidi, Moujahed; Park, Hun-Ho; Oyama, Kenichi; Bernat, Anne-Laure; Froelich, Sebastien

2018-04-27

The aim of this study was to identify key anatomical landmarks useful in gaining access to the anteromedial temporal region via the corridor formed by the inferior orbital fissure (IOF), the ophthalmic branch (V1), and the maxillary branch (V2) of the trigeminal nerve via the EEA. An anatomical dissection of six cadaver heads was performed to confirm the feasibility and applicability of the EEA for accessing the anteromedial temporal region. Following middle turbinectomy, the lateral recess of the sphenoid sinus was opened, the orbital apex exposed, and the posterior wall of the maxillary sinus was removed, in sequence. The IOF and the pterygopalatine fossa (PPF) were then identified. After opening the foramen rotundum (FR) and removing the bony structure between the FR, V2 was transposed downward. The orbital muscle of Müller was removed. The PPF was mobilized downward exposing the greater wing of the sphenoid bone (GWS). The GWS between V1 and V2 was drilled, thus exposing the temporal dura. With blunt dissection, the medial temporal dura was peeled away from the cavernous sinus (CS) in order to increase access to the anteromedial temporal region. In this study, the anteromedial temporal fossa was exposed by drilling the V1-V2 triangle corridor via the EEA. Endoscopic endonasal exposure of the anteromedial temporal fossa is feasible and requires limited endonasal work. This approach may be considered as an alternate surgical corridor to the temporomesial lobe that offers the advantages of a direct route with less temporal lobe retraction. Copyright © 2018. Published by Elsevier Inc.

High-resolution MRI of cranial nerves in posterior fossa at 3.0 T.

PubMed

Guo, Zi-Yi; Chen, Jing; Liang, Qi-Zhou; Liao, Hai-Yan; Cheng, Qiong-Yue; Fu, Shui-Xi; Chen, Cai-Xiang; Yu, Dan

2013-02-01

To evaluate the influence of high-resolution imaging obtainable with the higher field strength of 3.0 T on the visualization of the brain nerves in the posterior fossa. In total, 20 nerves were investigated on MRI of 12 volunteers each and selected for comparison, respectively, with the FSE sequences with 5 mm and 2 mm section thicknesses and gradient recalled echo (GRE) sequences acquired with a 3.0-T scanner. The MR images were evaluated by three independent readers who rated image quality according to depiction of anatomic detail and contrast with use of a rating scale. In general, decrease of the slice thickness showed a significant increase in the detection of nerves as well as in the image quality characteristics. Comparing FSE and GRE imaging, the course of brain nerves and brainstem vessels was visualized best with use of the three-dimensional (3D) pulse sequence. The comparison revealed the clear advantage of a thin section. The increased resolution enabled immediate identification of all brainstem nerves. GRE sequence most distinctly and confidently depicted pertinent structures and enables 3D reconstruction to illustrate complex relations of the brainstem. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Unstructured Adaptive (UA) NAS Parallel Benchmark. Version 1.0

NASA Technical Reports Server (NTRS)

Feng, Huiyu; VanderWijngaart, Rob; Biswas, Rupak; Mavriplis, Catherine

2004-01-01

We present a complete specification of a new benchmark for measuring the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

Preservation of the Myofascial Cuff During Posterior Fossa Surgery to Reduce the Rate of Pseudomeningocele Formation and Cerebrospinal Fluid Leak: A Technical Note

PubMed Central

Felbaum, Daniel R; Anaizi, Amjad; Mason, Robert B; Jean, Walter C; Voyadzis, Jean M

2016-01-01

Introduction: Suboccipital craniotomy is a workhorse neurosurgical operation for approaching the posterior fossa but carries a high risk of pseudomeningocele and cerebrospinal fluid (CSF) leak. We describe our experience with a simple T-shaped fascial opening that preserves the occipital myofascial cuff as compared to traditional methods to reduce this risk. Methods: A single institution, retrospective review of prospectively collected database was performed of patients that underwent a suboccipital craniectomy or craniotomy. Patient data was reviewed for craniotomy or craniectomy, dural graft, and/or sealant use as well as CSF complications. A pseudomeningocele was defined as a subcutaneous collection of cerebrospinal fluid palpable clinically and confirmed on imaging. A CSF leak was defined as a CSF-cutaneous fistula manifested by CSF leaking through the wound. All patients underwent regular postoperative visits of two weeks, one month, and three months. Results: Our retrospective review identified 33 patients matching the inclusion criteria. Overall, our cohort had a 21% (7/33) rate of clinical and radiographic pseudomeningocele formation with 9% (3/33) requiring surgical revision or a separate procedure. The rate of clinical and radiographic pseudomeningocele formation in the myofascial cuff preservation technique was less than standard techniques (12% and 31%, respectively). Revision or further surgical procedures were also reduced in the myofascial cuff preservation technique vs. the standard technique (6% vs 13%). Conclusions: Preservation of the myofascial cuff during posterior fossa surgery is a simple and adoptable technique that reduces the rate of pseudomeningocele formation and CSF leak as compared with standard techniques.   PMID:28133584

Preservation of the Myofascial Cuff During Posterior Fossa Surgery to Reduce the Rate of Pseudomeningocele Formation and Cerebrospinal Fluid Leak: A Technical Note.

PubMed

Felbaum, Daniel R; Mueller, Kyle; Anaizi, Amjad; Mason, Robert B; Jean, Walter C; Voyadzis, Jean M

2016-12-28

 Suboccipital craniotomy is a workhorse neurosurgical operation for approaching the posterior fossa but carries a high risk of pseudomeningocele and cerebrospinal fluid (CSF) leak. We describe our experience with a simple T-shaped fascial opening that preserves the occipital myofascial cuff as compared to traditional methods to reduce this risk.  A single institution, retrospective review of prospectively collected database was performed of patients that underwent a suboccipital craniectomy or craniotomy. Patient data was reviewed for craniotomy or craniectomy, dural graft, and/or sealant use as well as CSF complications. A pseudomeningocele was defined as a subcutaneous collection of cerebrospinal fluid palpable clinically and confirmed on imaging. A CSF leak was defined as a CSF-cutaneous fistula manifested by CSF leaking through the wound. All patients underwent regular postoperative visits of two weeks, one month, and three months.  Our retrospective review identified 33 patients matching the inclusion criteria. Overall, our cohort had a 21% (7/33) rate of clinical and radiographic pseudomeningocele formation with 9% (3/33) requiring surgical revision or a separate procedure. The rate of clinical and radiographic pseudomeningocele formation in the myofascial cuff preservation technique was less than standard techniques (12% and 31%, respectively). Revision or further surgical procedures were also reduced in the myofascial cuff preservation technique vs. the standard technique (6% vs 13%).  Preservation of the myofascial cuff during posterior fossa surgery is a simple and adoptable technique that reduces the rate of pseudomeningocele formation and CSF leak as compared with standard techniques.

UAS Integration in the NAS Project: Integrated Test and Evaluation (IT&E) Flight Test 3. Revision E

NASA Technical Reports Server (NTRS)

Marston, Michael

2015-01-01

The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

Compositional dependence of the band gap in Ga(NAsP) quantum well heterostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jandieri, K., E-mail: kakhaber.jandieri@physik.uni-marburg.de; Ludewig, P.; Wegele, T.

We present experimental and theoretical studies of the composition dependence of the direct band gap energy in Ga(NAsP)/GaP quantum well heterostructures grown on either (001) GaP- or Si-substrates. The theoretical description takes into account the band anti-crossing model for the conduction band as well as the modification of the valence subband structure due to the strain resulting from the pseudomorphic epitaxial growth on the respective substrate. The composition dependence of the direct band gap of Ga(NAsP) is obtained for a wide range of nitrogen and phosphorus contents relevant for laser applications on Si-substrate.

Late Noachian/Early Hesperian Ridge Network in Nili Fossae: Evidence for Water-Saturated Near-Surface Crust

NASA Astrophysics Data System (ADS)

Mustard, J. F.; Pascuzzo, A.

2017-12-01

The region north of the contact between Syrtis Major and the Isidis Basin is populated by thousands of ridges 100s of meters in length, up to a few 10s of meters high and 15-50 meters wide. The resistant ridges are being exhumed from weak early Noachian smectite-bearing host rocks. Hypotheses for the formation include igneous intrusion or fill, impact-induced breccia dikes and chemical alteration of pre-existing fracture planes or mineralized fracture planes through groundwater circulation (our preferred mode of formation). Mineralogic interpretations of visible-near infrared reflectance spectra from the CRISM instrument on MRO may be critical in interpreting the formation process. While most of the ridges are at the limit of CRISM's spatial resolution of 18 m/pixel, CRISM has a special observing mode which can increase the resolution in the along track observing (ATO) direction by a factor of 2-3 (e.g. 6 m). Using a combination of full resolution and one ATO observation, we have analyzed well-exposed ridges in the Nili Fossae region. Ridges are commonly exposed from beneath a distinctive mafic capping rock rich in olivine and variably altered to magnesite. Many of the ridges exhibit weaker smectite absorptions near 1.9 and 2.3 µm compared to the host rock but no additional spectral features are observed. One cause for weaker absorptions is grain size (i.e. solid rock shows weaker absorptions than its powdered equivalent). Alternatively the presence of a spectrally neutral cementing compound or mineral like quartz could lead to weaker features. Timing of ridge formation is constrained by two key stratigraphic makers. First the ridges were likely formed after the Isidis basin-forming event, 3.9 Ga, because many are observed between the 1st and 2nd rings of the basin structure and would not have survived the impact event otherwise. Second the ridges are exhumed from beneath a distinctive olivine-rich mafic cap unit with its emplacement dated to between the Isidis

A morphometric study of the atlas occipitalization and coexisted congenital anomalies of the vertebrae and posterior cranial fossa with neurological importance.

PubMed

Natsis, Konstantinos; Lyrtzis, Christos; Totlis, Trifon; Anastasopoulos, Nikolaos; Piagkou, Maria

2017-01-01

Our study highlights the morphometry of the partial and complete atlas occipitalization (AOZ), its coexistence with fusions of the 2nd and 3rd cervical vertebrae and morphological and morphometric abnormalities of the posterior cranial fossa that are of paramount neurological importance. One hundred and eighty adult dry skulls, the atlas and axis vertebrae were examined. Four skulls (2.2 %) showed AOZ. Two of them (1.1 %) presented a partial AOZ, one male skull (0.6 %) a complete AOZ and a female skull (0.6 %) had a fused left hemiatlas with the occipital bone and a fusion of the 2nd and 3rd cervical vertebrae. The inner anteroposterior and transverse diameters of the foramen magnum (FM) in the control group were 34.6 ± 3.46 and 29.3 ± 3.47 mm. Only the skull with the complete AOZ had a reduced outer anteroposterior diameter of the FM (29.8 mm), while no specimen was found with a reduced transverse diameter. A wide total decrease (range 13.1-50.9 %) in the surface area of the FM in skulls with AOZ was detected. Extracranial, the clivus length in two skulls with AOZ was smaller than the normal range. No skull was detected with a reduction in the intracranial length of the clivus. All skulls with the AOZ had a vermian fossa. The study adds important morphometric details about the partial and complete AOZ and correlates the phenomenon of synostosis with the narrowing of the FM, particularly in the case of complete AOZ. Awareness of the AOZ and other fusions of the upper cervical vertebrae and their topographical relations and attendant problems are of paramount importance to surgeons, when operate to the craniocervical junction, or interpret imaging studies to plan a safe surgery for nerve or spinal tissue decompression.

Multifractal modeling, segmentation, prediction, and statistical validation of posterior fossa tumors

NASA Astrophysics Data System (ADS)

Islam, Atiq; Iftekharuddin, Khan M.; Ogg, Robert J.; Laningham, Fred H.; Sivakumar, Bhuvaneswari

2008-03-01

In this paper, we characterize the tumor texture in pediatric brain magnetic resonance images (MRIs) and exploit these features for automatic segmentation of posterior fossa (PF) tumors. We focus on PF tumor because of the prevalence of such tumor in pediatric patients. Due to varying appearance in MRI, we propose to model the tumor texture with a multi-fractal process, such as a multi-fractional Brownian motion (mBm). In mBm, the time-varying Holder exponent provides flexibility in modeling irregular tumor texture. We develop a detailed mathematical framework for mBm in two-dimension and propose a novel algorithm to estimate the multi-fractal structure of tissue texture in brain MRI based on wavelet coefficients. This wavelet based multi-fractal feature along with MR image intensity and a regular fractal feature obtained using our existing piecewise-triangular-prism-surface-area (PTPSA) method, are fused in segmenting PF tumor and non-tumor regions in brain T1, T2, and FLAIR MR images respectively. We also demonstrate a non-patient-specific automated tumor prediction scheme based on these image features. We experimentally show the tumor discriminating power of our novel multi-fractal texture along with intensity and fractal features in automated tumor segmentation and statistical prediction. To evaluate the performance of our tumor prediction scheme, we obtain ROCs and demonstrate how sharply the curves reach the specificity of 1.0 sacrificing minimal sensitivity. Experimental results show the effectiveness of our proposed techniques in automatic detection of PF tumors in pediatric MRIs.

Self-assembled GaInNAs/GaAsN quantum dot lasers: solid source molecular beam epitaxy growth and high-temperature operation

PubMed Central

Liu, CY; Sun, ZZ; Yew, KC

2006-01-01

Self-assembled GaInNAs quantum dots (QDs) were grown on GaAs (001) substrate using solid-source molecular-beam epitaxy (SSMBE) equipped with a radio-frequency nitrogen plasma source. The GaInNAs QD growth characteristics were extensively investigated using atomic-force microscopy (AFM), photoluminescence (PL), and transmission electron microscopy (TEM) measurements. Self-assembled GaInNAs/GaAsN single layer QD lasers grown using SSMBE have been fabricated and characterized. The laser worked under continuous wave (CW) operation at room temperature (RT) with emission wavelength of 1175.86 nm. Temperature-dependent measurements have been carried out on the GaInNAs QD lasers. The lowest obtained threshold current density in this work is ∼1.05 kA/cm2from a GaInNAs QD laser (50 × 1,700 µm2) at 10 °C. High-temperature operation up to 65 °C was demonstrated from an unbonded GaInNAs QD laser (50 × 1,060 µm2), with high characteristic temperature of 79.4 K in the temperature range of 10–60 °C.

UAS in the NAS Flight Test Series 3 Overview

NASA Technical Reports Server (NTRS)

Murphy, James R.

2015-01-01

The UAS Integration in the NAS Project is conducting a series of flight tests to acheive the following objectives: 1.) Validate results previously collected during project simulations with live data 2.) Evaluate TCAS IISS interoperability 3.) Test fully integrated system in a relevant live test environment 4.) Inform final DAA and C2 MOPS 5.) Reduce risk for Flight Test Series 4.

UAS-NAS Project Demo - Mini HITL Week 2 Stats

NASA Technical Reports Server (NTRS)

Murphy, James R.; Fern, Lisa C.; Rorie, Robert C.; Shively, Robert; Jovic, Srboljub

2016-01-01

The UAS-NAS Project demo will showcase recent research efforts to ensure the interoperability between proposed UAS detect and avoid (DAA) human machine interface requirements (developed within RTCA SC-228) and existing collision avoidance displays. Attendees will be able to view the current state of the art of the DAA pilot traffic, alerting and guidance displays integrated with Traffic advisory and Collision Avoidance (TCAS) II in the UAS-NAS Project's research UAS ground control station (developed in partnership with the Air Force Research Laboratory). In addition, attendees will have the opportunity to interact with the research UAS ground control station and "fly" encounters, using the DAA and TCAS II displays to avoid simulated aircraft. The display of the advisories will be hosted on a laptop with an external 30" monitor, running the Vigilant Spirit system. DAA advisories will be generated by the JADEM software tool, connected to the system via the LVC Gateway. A repeater of the primary flight display will be shown on a 55" monitor mounted on a stand at the back of the booth to show the pilot interaction to the passersby.

Greenhouse policy study from NAS

NASA Astrophysics Data System (ADS)

Maggs, William Ward

The National Academy of Sciences will produce a study for the Environmental Protection Agency on policy responses to global warming. The report is due out before the end of 1990.Dan J. Evans, former U.S. Senator and former Governor of Washington, will chair a panel of the Commission on Science, Engineering, and Public Policy, a body of the councils of the NAS, National Academy of Engineering, and Institute of Medicine. Evans is a registered civil engineer and previously chaired the Pacific Northwest Electric Power and Conservation Planning Council.The 13-person panel includes AGU members Stephen Schneider of the National Center for Atmospheric Research and Robert Frosch, Vice President of Research Laboratores at General Motors Corp., Jessica Mathews, Vice President of the World Resources Institute, and Sir Crispin Tickell, the United Kingdom's Ambassador to the United Nations.

Temporal lobe sulcal pattern and the bony impressions in the middle cranial fossa: the case of the el Sidrón (Spain) neandertal sample.

PubMed

Rosas, Antonio; Peña-Melián, Angel; García-Tabernero, Antonio; Bastir, Markus; De La Rasilla, Marco

2014-12-01

Correspondence between temporal lobe sulcal pattern and bony impressions on the middle cranial fossae (MCF) was analyzed. MCF bone remains (SD-359, SD-315, and SD-1219) from the El Sidrón (Spain) neandertal site are analyzed in this context. Direct comparison of the soft and hard tissues from the same individual was studied by means of: 1) dissection of two human heads; 2) optic (white light) surface scans; 3) computed tomography and magnetic resonance of the same head. The inferior temporal sulcus and gyrus are the features most strongly influencing MCF bone surface. The Superior temporal sulcus and middle temporal and fusiform gyri also leave imprints. Temporal lobe form differs between Homo sapiens and neandertals. A wider and larger post-arcuate fossa (posterior limit of Brodmann area 20 and the anterior portion of area 37) is present in modern humans as compared to neandertals. However other traits of the MCF surface are similar in these two large-brained human groups. A conspicuous variation is appreciated in the more vertical location of the inferior temporal gyrus in H. sapiens. In parallel, structures of the lower surface of the temporal lobe are more sagittally orientated. Grooves accommodating the fusiform and the lower temporal sulci become grossly parallel to the temporal squama. These differences can be understood within the context of a supero-lateral deployment of the lobe in H. sapiens, a pattern previously identified (Bastir et al., Nat Commun 2 (2011) 588-595). Regarding dural sinus pattern, a higher incidence of petrosquamous sinus is detected in neandertal samples. © 2014 Wiley Periodicals, Inc.

Reference Ranges for Transvaginal Examined Fossa Posterior Structures in Fetuses from 45 to 84 mm Crown-Rump Length.

PubMed

Altmann, Reinhard; Specht, Christian; Scharnreitner, Iris; Schertler, Caroline; Mayer, Richard; Arzt, Wolfgang; Scheier, Matthias

2018-06-05

The study aimed to describe reference values for structures of the posterior fossa in fetuses with a crown-rump length (CRL) between 45 and 84 mm. This was a prospective, cross-sectional study including 216 normal appearing fetuses. In transvaginal acquired 3-dimensional volume blocks, the longest diameter of the vermis (VE), posterior membranous area (PMA), medulla-oblongata-pons angle (MOPA), diameters of the medulla oblongata (MO) and pons (PO), and the area of Blake's pouch (BP) were measured. Polynomial or linear regression analysis were performed to calculate the mean, 5th and 95th centile according to CRL. In 20 fetuses, intra- and interobserver repeatability were calculated. There is a curvilinear correlation between CRL and PO (PO [mean] = 1.3893 + 0.004356 × CRL + 0.000002610 × CRL3; SD = 1.6818 - 0.03765 × CRL + 0.000003831 × CRL3; R2 = 0.489); CRL and MO (MO [mean] = 1.5959-0.001905 × CRL + 0.000003362*CRL3; SD = -0.1417 + 0.005404 × CRL + 0.0000004988 × CRL3; R2 = 0.525); CRL and VE (VE [mean] = -0.3640 + 0.04302 × CRL+ 0.000001486 × CRL3; SD = 0.5854 - 0.004812 × CRL + 0.0000005896 × CRL3; R2 = 0.643); CRL and PMA (PMA [mean] = 0.6901 + 0.04307 × CRL - 0.0000008459 × CRL3; SD = -0.4232 + 0.02026 × CRL - 0.000001320 × CRL3; R2 = 0.272); CRL and BP (mm2; BP [mean] -12.2067 + 0.3334 × CRL - 0.00001262 × CRL3; SD = -1.6431 + 0.06380 × CRL+ 0.0000003257 × CRL3; R2 = 0.289). The relation between CRL and MOPA (°) is best described by a linear regression (MOPA [mean] = 79.6332 + 0.6122 × CRL; SD = 4.8453 + 0.07333 × CRL; R2 = 0.318). We provide reference values for anatomical structures of the posterior fossa of fetuses between 45 and 84 mm CRL. The established reference values might ease the diagnosis of fetal malformations in early pregnancy. © 2018 S. Karger AG, Basel.

Lineated Valley Fills and Lobate Debris Aprons in Coloe Fossae: Evolutionary characteristics and time-stratigraphic relationships.

NASA Astrophysics Data System (ADS)

Schreiner, Björn; van Gasselt, Stephan; Neukum, Gerhard; HRSC Co-Investigator Team

2010-05-01

Mid-latitude regions of Mars, especially the crustal dichotomy boundary between highlands and northern lowlands are characterized by lineated valley fills (LVF) and lobate debris aprons (LDA). These features reveal evidence of ice-rich deposits. LDAs are assumed to consist of a mixture of ice and rock/debris consistent with models of apron formation such as rock glacier ice assisted creep of talus, ice-rich landslides, or debris-covered glaciers. Deposition of ice at these latitudes is consistent with athmospheric circulation models and predictions of spin axis and orbital variations for the past history of Mars. In this study we measured crater size frequency distributions of LVS and LDA including unrelaxed glacier-like convex bodies in the Coloe Fossae region (35°N, 55°E) and determined late amazonian crater retention ages of 30-50 Ma and 80-100 Ma which gives evidence of repeated deposition of mantling material from surrounding head walls with continuous resurfacing between active periods. We use new HRSC data for topography and imaging in conjunction with high resolution CTX imaging data.

Functional Requirements Document for HALE UAS Operations in the NAS: Step 1. Version 3

NASA Technical Reports Server (NTRS)

2006-01-01

The purpose of this Functional Requirements Document (FRD) is to compile the functional requirements needed to achieve the Access 5 Vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the national airspace system (NAS)" for Step 1. These functional requirements could support the development of a minimum set of policies, procedures and standards by the Federal Aviation Administration (FAA) and various standards organizations. It is envisioned that this comprehensive body of work will enable the FAA to establish and approve regulations to govern safe operation of UAS in the NAS on a routine or daily "file and fly" basis. The approach used to derive the functional requirements found within this FRD was to decompose the operational requirements and objectives identified within the Access 5 Concept of Operations (CONOPS) into the functions needed to routinely and safely operate a HALE UAS in the NAS. As a result, four major functional areas evolved to enable routine and safe UAS operations for an on-demand basis in the NAS. These four major functions are: Aviate, Navigate, Communicate, and Avoid Hazards. All of the functional requirements within this document can be directly traceable to one of these four major functions. Some functions, however, are traceable to several, or even all, of these four major functions. These cross-cutting functional requirements support the "Command / Control: function as well as the "Manage Contingencies" function. The requirements associated to these high-level functions and all of their supporting low-level functions are addressed in subsequent sections of this document.

Liquid Posterior Fossa Epidural Hematoma in Pediatric Trauma: A Single-Center Case Series.

PubMed

Han, Kun; Li, Zhaojian; Yin, Hongwei; Yao, Weicheng; Lan, Xiaolei; Bo, Yongli

2018-06-14

 Liquid posterior fossa epidural hematoma (LPFEH) following head trauma is uncommon, and very few such cases have been described in the literature. Eight patients with this entity and their treatments are presented here.  We performed a single-institution retrospective analysis of all patients with diagnosed LPFEH over a 3-year period. Collected data included clinical history, laboratory results, treatment, and review of all imaging studies performed.  Eight pediatric cases were identified with imaging findings consistent with LPFEH; no adult case was identified. Enlargement of ventricles appeared on computed tomography (CT) in six cases, and secondary epilepsy onset occurred in three cases with severe dilated ventricles. Routine hematologic and coagulation tests failed to disclose anemia or abnormal coagulation in each case. Five patients underwent burr-hole drainage of the hematoma and recovered completely. Conservative therapy was adopted in three patients for small hematomas, and hematoma enlargement was not observed in the follow-up CT scans.  LPFEH is a rare subtype of traumatic epidural hematoma specifically recognized in the pediatric population. Minimally invasive burr-hole drainage is a feasible procedure for the patient with evident space-occupying effect. Coagulation dysfunction or low hemoglobin as a possible contributing factor and its role in formation of LPFEH was excluded. Georg Thieme Verlag KG Stuttgart · New York.

[Ethmoid sinus mucocele penetrating to the orbit and anterior cranial fossa - case report].

PubMed

Paradowska-Opałka, Beata; Kawczyński, Maciej; Jaworowska, Ewa

2013-01-01

Paranasal sinus mucocele is the cystic formation lined by inflammatory changed mucoperiosteum. This is slow-growing pathology with a tendency to bone erosion. The symptoms are dependent on the direction of the penetration, and are as follows: increasing headaches, deformations of frontal or orbital region, ophthalmic manifestations such as lacrimation, decreased visual acuity, exophthalmos, ocular movement limitation, diplopia. The most common location of the mucocele is fronto-ethmoid region. The most useful diagnostic tests are a magnetic resonance imaging (MRI) and a computed tomography (CT) which show the progress of the disease and bone destructions. Surgery is the only method of treatment (external approach or FESS). This paper reports the case of a 74-year-old woman with ethmoid mucocele penetrating into the orbit, frontal sinus and anterior cranial fossa with compression of frontal lobe of the brain. The patient underwent CT and MRI and was treated with endoscopic intranasal marsupialization of the cyst. There are no clinical signs of disease recurrence 7 months after surgery. The endoscopic surgical management in treatment of sinus mucocele is a good alternative to the operation from external approach because of its low invasiveness, low complication risk, rapid healing and good therapeutic effects. Copyright © 2012 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

The CAS-NAS forum for new leaders in space science

NASA Astrophysics Data System (ADS)

Smith, David H.

The space science community is thoroughly international, with numerous nations now capable of launching scientific payloads into space either independently or in concert with others. As such, it is important for national space-science advisory groups to engage with like-minded groups in other spacefaring nations. The Space Studies Board of the US National Academy of Sciences' (NAS') National Research Council has provided scientific and technical advice to NASA for more than 50 years. Over this period, the Board has developed important multilateral and bilateral partnerships with space scientists around the world. The primary multilateral partner is COSPAR, for which the Board serves as the US national committee. The Board's primary bilateral relationship is with the European Science Foundation’s European Space Science Committee. Burgeoning Chinese space activities have resulted in several attempts in the past decade to open a dialogue between the Board and space scientists in China. On each occasion, the external political environment was not conducive to success. The most recent efforts to engage the Chinese space researchers began in 2011 and have proved particularly successful. Although NASA is currently prohibited from engaging in bilateral activities with China, the Board has established a fruitful dialogue with its counterpart in the Chinese Academy of Sciences (CAS). A joint NAS-CAS activity, the Forum for New Leaders in Space Science, has been established to provide opportunities for a highly select group of young space scientists from China and the United States to discuss their research activities in an intimate and collegial environment at meetings to be held in both nations. The presentation will describe the current state of US-China space relations, discuss the goals of the joint NAS-CAS undertaking and report on the activities at the May, 2014, Forum in Beijing and the planning for the November, 2014, Forum in Irvine, California.

UAS in the NAS - Analysis Results and Recommendations for Integration of CNPC and ATC Communications Simulation Report

NASA Technical Reports Server (NTRS)

Kubat, Gregory

2016-01-01

This report addresses a deliverable to the UAS-in-the-NAS project for recommendations for integration of CNPC and ATC communications based on analysis results from modeled radio system and NAS-wide UA communication architecture simulations. For each recommendation, a brief explanation of the rationale for its consideration is provided with any supporting results obtained or observed in our simulation activity.

Efficacy of texture, shape, and intensity features for robust posterior-fossa tumor segmentation in MRI

NASA Astrophysics Data System (ADS)

Ahmed, S.; Iftekharuddin, K. M.; Ogg, R. J.; Laningham, F. H.

2009-02-01

Our previous works suggest that fractal-based texture features are very useful for detection, segmentation and classification of posterior-fossa (PF) pediatric brain tumor in multimodality MRI. In this work, we investigate and compare efficacy of our texture features such as fractal and multifractional Brownian motion (mBm), and intensity along with another useful level-set based shape feature in PF tumor segmentation. We study feature selection and ranking using Kullback -Leibler Divergence (KLD) and subsequent tumor segmentation; all in an integrated Expectation Maximization (EM) framework. We study the efficacy of all four features in both multimodality as well as disparate MRI modalities such as T1, T2 and FLAIR. Both KLD feature plots and information theoretic entropy measure suggest that mBm feature offers the maximum separation between tumor and non-tumor tissues in T1 and FLAIR MRI modalities. The same metrics show that intensity feature offers the maximum separation between tumor and non-tumor tissue in T2 MRI modality. The efficacies of these features are further validated in segmenting PF tumor using both single modality and multimodality MRI for six pediatric patients with over 520 real MR images.

Minimally Invasive Supraorbital Key-hole Approach for the Treatment of Anterior Cranial Fossa Meningiomas

PubMed Central

IACOANGELI, Maurizio; NOCCHI, Niccolò; NASI, Davide; DI RIENZO, Alessandro; DOBRAN, Mauro; GLADI, Maurizio; COLASANTI, Roberto; ALVARO, Lorenzo; POLONARA, Gabriele; SCERRATI, Massimo

2016-01-01

The most important target of minimally invasive surgery is to obtain the best therapeutic effect with the least iatrogenic injury. In this background, a pivotal role in contemporary neurosurgery is played by the supraorbital key-hole approach proposed by Perneczky for anterior cranial base surgery. In this article, it is presented as a possible valid alternative to the traditional craniotomies in anterior cranial fossa meningiomas removal. From January 2008 to January 2012 at our department 56 patients underwent anterior cranial base meningiomas removal. Thirty-three patients were submitted to traditional approaches while 23 to supraorbital key-hole technique. A clinical and neuroradiological pre- and postoperative evaluation were performed, with attention to eventual complications, length of surgical procedure, and hospitalization. Compared to traditional approaches the supraorbital key-hole approach was associated neither to a greater range of postoperative complications nor to a longer surgical procedure and hospitalization while permitting the same lesion control. With this technique, minimization of brain exposition and manipulation with reduction of unwanted iatrogenic injuries, neurovascular structures preservation, and a better aesthetic result are possible. The supraorbital key-hole approach according to Perneckzy could represent a valid alternative to traditional approaches in anterior cranial base meningiomas surgery. PMID:26804334

Chromosomal aneuploidies and copy number variations in posterior fossa abnormalities diagnosed by prenatal ultrasonography.

PubMed

Lei, Ting; Feng, Jie-Ling; Xie, Ying-Jun; Xie, Hong-Ning; Zheng, Ju; Lin, Mei-Fang

2017-11-01

To explore the genetic aetiology of fetal posterior fossa abnormalities (PFAs). This study involved cases of PFAs that were identified by prenatal ultrasonographic screening and confirmed postnatally between January 2012 and January 2016. Conventional cytogenetic analyses and chromosomal microarray analysis were performed, and chromosomal aneuploidies and copy number variations (CNVs) were identified. Among 74 cases included in this study, 8 were of Blake's pouch cyst; 7, Dandy-Walker malformation; 11, vermian hypoplasia; 32, enlarged cisterna magna; and 16, cerebellar hypoplasia. The rates of nonbenign chromosomal aberrations (including chromosomal aneuploidies, pathogenic CNVs, and variants of unknown significance) were 2/8 (25.0%), 2/7 (28.5%), 8/11 (72.7%), 7/32 (21.9%), and 6/16 (37.5%), respectively. Cases were also classified as isolated PFAs (30/74), PFAs with other central nervous system (CNS) abnormalities (13/74), or PFAs with extra-CNS structural abnormalities (31/74). No fetuses with isolated PFAs or PFAs accompanied by other CNS abnormalities exhibited chromosomal aneuploidies or pathogenic CNVs. The rate of pathogenic chromosomal aberrations in the remaining fetuses was 17/31 (22.9%). The combined use of chromosomal microarray analysis and karyotype analysis might assist the prenatal diagnosis and management of PFAs, with extra-CNS structural abnormalities being detected by ultrasonography. © 2017 John Wiley & Sons, Ltd.

Supercomputing 2002: NAS Demo Abstracts

NASA Technical Reports Server (NTRS)

Parks, John (Technical Monitor)

2002-01-01

The hyperwall is a new concept in visual supercomputing, conceived and developed by the NAS Exploratory Computing Group. The hyperwall will allow simultaneous and coordinated visualization and interaction of an array of processes, such as a the computations of a parameter study or the parallel evolutions of a genetic algorithm population. Making over 65 million pixels available to the user, the hyperwall will enable and elicit qualitatively new ways of leveraging computers to accomplish science. It is currently still unclear whether we will be able to transport the hyperwall to SC02. The crucial display frame still has not been completed by the metal fabrication shop, although they promised an August delivery. Also, we are still working the fragile node issue, which may require transplantation of the compute nodes from the present 2U cases into 3U cases. This modification will increase the present 3-rack configuration to 5 racks.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project KDP-C Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Sakahara, Robert; Hackenberg, Davis; Johnson, William

2017-01-01

The topics discussed are the UAS-NAS project life-cycle and ARMD thrust flow down, as well as the UAS environments and how we operate in those environments. NASA's Armstrong Flight Research Center at Edwards, CA, is leading a project designed to help integrate unmanned air vehicles into the world around us. The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS in the NAS, will contribute capabilities designed to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The project falls under the Integrated Systems Research Program office managed at NASA Headquarters by the agency's Aeronautics Research Mission Directorate. NASA's four aeronautics research centers - Armstrong, Ames Research Center, Langley Research Center, and Glenn Research Center - are part of the technology development project. With the use and diversity of unmanned aircraft growing rapidly, new uses for these vehicles are constantly being considered. Unmanned aircraft promise new ways of increasing efficiency, reducing costs, enhancing safety and saving lives 460265main_ED10-0132-16_full.jpg Unmanned aircraft systems such as NASA's Global Hawks (above) and Predator B named Ikhana (below), along with numerous other unmanned aircraft systems large and small, are the prime focus of the UAS in the NAS effort to integrate them into the national airspace. Credits: NASA Photos 710580main_ED07-0243-37_full.jpg The UAS in the NAS project envisions performance-based routine access to all segments of the national airspace for all unmanned aircraft system classes, once all safety-related and technical barriers are overcome. The project will provide critical data to such key stakeholders and customers as the Federal Aviation Administration and RTCA Special Committee 203 (formerly the Radio Technical Commission for Aeronautics) by conducting integrated, relevant system-level tests to adequately address

Theoretical studies of optical gain tuning by hydrostatic pressure in GaInNAs/GaAs quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gladysiewicz, M.; Wartak, M. S.; Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5

In order to describe theoretically the tuning of the optical gain by hydrostatic pressure in GaInNAs/GaAs quantum wells (QWs), the optical gain calculations within kp approach were developed and applied for N-containing and N-free QWs. The electronic band structure and the optical gain for GaInNAs/GaAs QW were calculated within the 10-band kp model which takes into account the interaction of electron levels in the QW with the nitrogen resonant level in GaInNAs. It has been shown that this interaction increases with the hydrostatic pressure and as a result the optical gain for GaInNAs/GaAs QW decreases by about 40% and 80%more » for transverse electric and transverse magnetic modes, respectively, for the hydrostatic pressure change from 0 to 40 kilobars. Such an effect is not observed for N-free QWs where the dispersion of electron and hole energies remains unchanged with the hydrostatic pressure. This is due to the fact that the conduction and valence band potentials in GaInAs/GaAs QW scale linearly with the hydrostatic pressure.« less

NAS Requirements Checklist for Job Queuing/Scheduling Software

NASA Technical Reports Server (NTRS)

Jones, James Patton

1996-01-01

The increasing reliability of parallel systems and clusters of computers has resulted in these systems becoming more attractive for true production workloads. Today, the primary obstacle to production use of clusters of computers is the lack of a functional and robust Job Management System for parallel applications. This document provides a checklist of NAS requirements for job queuing and scheduling in order to make most efficient use of parallel systems and clusters for parallel applications. Future requirements are also identified to assist software vendors with design planning.

Optical Properties of A GaInNAs Multi-Quantum Well Semiconductor

NASA Astrophysics Data System (ADS)

Hughes, Timothy S.; Ren, Shang-Fen; Jiang, De-Sheng; Xiaogan, Liang

2002-03-01

Optoelectronic devices used today depend on lasers that have wavelengths in the optical fiber transmission window of 1.3 to 1.55 micrometers. When using GaAs substrate semiconductor lasers, we typically see this range of light emission. Quaternary materials, such as GaInNAs grown on this substrate, not only allow us to control the output wavelength, but it also allows us to manipulate the lattice constant. Further research has potential to produce low-costing highly efficient Vertical Cavity Surface Emitting Lasers (VCSEL). Using a Fourier-Transform Spectrometer, a method of using a Michelson Interferometer to measure the interference between two coherent beams, we measured and analyzed the photoluminescence spectra of a GaInNAs multi-quantum well semiconductor, grown using the Molecular Beam Epitaxy (MBE) growth technique. The experiments of this research were carried out in an undergraduate international research experience at the Chinese Semiconductor Institute supported by the Division of International Programs of NSF.

A Descriptive Analysis of Nursing Staff Behaviors in a Teaching Nursing Home: Differences among NAs, LPNs, and RNs.

ERIC Educational Resources Information Center

Burgio, Louis D.; And Others

1990-01-01

Various staff behaviors in nursing home were sampled 7 times a day, 5 days a week over 37 months and were coded separately for registered nurses (RNs), licensed practical nurses (LPNs), and nurses' aides (NAs). Found LPNs displayed significantly more patient care behaviors and NAs significantly more nonwork behaviors than other nursing staff. RNs…

Concepts of Integration for UAS Operations in the NAS

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Chamberlain, James P.; Munoz, Cesar A.; Hoffler, Keith D.

2012-01-01

One of the major challenges facing the integration of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is the lack of an onboard pilot that can comply with the legal requirement identified in the US Code of Federal Regulations (CFR) that pilots see and avoid other aircraft. UAS will be expected to demonstrate the means to perform the function of see and avoid while preserving the safety level of the airspace and the efficiency of the air traffic system. This paper introduces a Sense and Avoid (SAA) concept for integration of UAS into the NAS that is currently being developed by the National Aeronautics and Space Administration (NASA) and identifies areas that require additional experimental evaluation to further inform various elements of the concept. The concept design rests on interoperability principles that take into account both the Air Traffic Control (ATC) environment as well as existing systems such as the Traffic Alert and Collision Avoidance System (TCAS). Specifically, the concept addresses the determination of well clear values that are large enough to avoid issuance of TCAS corrective Resolution Advisories, undue concern by pilots of proximate aircraft and issuance of controller traffic alerts. The concept also addresses appropriate declaration times for projected losses of well clear conditions and maneuvers to regain well clear separation.

The role of N-H complexes in the control of localized center recombination in hydrogenated GaInNAs (Conference Presentation)

NASA Astrophysics Data System (ADS)

Whiteside, Vincent R.; Fukuda, Miwa; Estes, Nicholas J.; Wang, Bin; Brown, Collin R.; Hossain, Khalid; Golding, Terry D.; Leroux, Mathieu; Al Khalfioui, Mohamed; Tischler, Joseph G.; Ellis, Chase T.; Glaser, Evan R.; Sellers, Ian R.

2017-04-01

A significant improvement in the quality of dilute nitrides has recently led to the ability to reveal depletion widths in excess of 1 μm at 1 eV [1]. The real viability of dilute nitrides for PV has been recently demonstrated with the reporting of a record efficiency of 43.5% from a 4J MJSC including GaInNAs(Sb) [2]. Despite the progress made, these materials remain poorly understood and work continues to improve their lifetime and reproducibility. We have investigated the possibility of improving the functionality of GaInNAs using hydrogenation to selectively passivate mid-gap defects, while preserving the substitutional nitrogen. Temperature dependent photoluminescence measurements of the intrinsic region of a GaInNAs p-i-n solar cell show a classic "s-shape" associated with localization prior to hydrogenation. No sign of this "s-shape" is evident after hydrogenation, despite the retention of substitutional nitrogen as evidenced by the band absorption of 1 eV. The absence of an "s-shape" at low-temperature in hydrogenated GaInNAs is rather curious since, even in high quality nitrides this behavior is due to the emission of isoelectronic centers created via N-As substitution [3]. The potential origins of this behavior will be discussed. The promise of this process for GaInNAs solar cells was demonstrated by a three-fold improvement in the performance of a hydrogenated device with respect to an as-grown reference [4]. [1] "Wide-depletion width GaInNAs solar cells by thermal annealing," I. R. Sellers, W-S. Tan, K. Smith, S. Hooper, S. Day and M. Kauer, Applied Physics Letters 99, 151111 (2011) [2] "43.5% efficient lattice matched solar cells," M. Wiemer, V. Sabnis, and H. Yuen, Proc. SPIE 8108, 810804 (2011) [3]"Probing the nature of carrier localization in GaInNAs, epilayers using optical methods," T. Ysai, B. Barman, T. Scarce, G. Lindberg, M. Fukuda, V. R. Whiteside, J. C. Keay, M. B. Johnson, I. R. Sellers, M. Al Khalfioui, M. Leroux, B. A. Weinstein and A

Neonatal Abstinence Syndrome (NAS): Transitioning Methadone Treated Infants From An Inpatient to an Outpatient Setting

PubMed Central

Backes, Carl H.; Backes, Carl R.; Gardner, Debra; Nankervis, Craig A.; Giannone, Peter J.; Cordero, Leandro

2013-01-01

Background Each year in the US approximately 50,000 neonates receive inpatient pharmacotherapy for the treatment of neonatal abstinence syndrome (NAS). Objective To compare the safety and efficacy of a traditional inpatient only approach with a combined inpatient and outpatient methadone treatment program. Design/Methods Retrospective review (2007-9). Infants were born to mothers maintained on methadone or buprenorphine in an antenatal substance abuse program. All infants received methadone for NAS treatment as inpatient. Methadone weaning for the traditional group (75 pts) was inpatient while the combined group (46 pts) was outpatient. Results Infants in the traditional and combined groups were similar in demographics, obstetrical risk factors, birth weight, GA and the incidence of prematurity (34 & 31%). Hospital stay was shorter in the combined than in the traditional group (13 vs 25d; p < 0.01). Although the duration of treatment was longer for infants in the combined group (37 vs 21d, p<0.01), the cumulative methadone dose was similar (3.6 vs 3.1mg/kg, p 0.42). Follow-up: Information was available for 80% of infants in the traditional and 100% of infants in the combined group. All infants in the combined group were seen ≤ 72 hours from hospital discharge. Breast feeding was more common among infants in the combined group (24 vs. 8% p<0.05). Following discharge there were no differences between the two groups in hospital readmissions for NAS. Prematurity (<37w GA) was the only predictor for hospital readmission for NAS in both groups (p 0.02, OR 5). Average hospital cost for each infant in the combined group was $13,817 less than in the traditional group. Conclusions A combined inpatient and outpatient methadone treatment in the management of NAS decreases hospital stay and substantially reduces cost. Additional studies are needed to evaluate the potential long term benefits of the combined approach on infants and their families. PMID:21852772

Evidence for Recent Liquid Water on Mars: Gullies in Sirenum Fossae Trough

NASA Technical Reports Server (NTRS)

2000-01-01

This mosaic of two Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images shows about 20 different gullies coming down the south-facing wall of a trough in the Sirenum Fossae/Gorgonum Chaos region of the martian southern hemisphere. Each channel and its associated fan--or apron--of debris appears to have started just below the same hard, resistant layer of bedrock located approximately 100 meters (about 325 feet) below the top of the trough wall. The layer beneath this hard, resistant bedrock is interpreted to be permeable, which allows ground water to percolate through it and--at the location of this trough--seep out onto the martian surface. The channels and aprons only occur on the south-facing slope of this valley created by faults on each side of the trough. The depression is approximately 1.4 km (0.9 mi) across.

The mosaic was constructed from two pictures taken on September 16, 1999, and May 1, 2000. The black line is a gap between the two images that was not covered by MOC. The scene covers an area approximately 5.5 kilometers (3.4 miles) wide by 4.9 km (3.0 mi) high. Sunlight illuminates the area from the upper left. The image is located near 38.5oS, 171.3oW. MOC high resolution images are taken black-and-white (grayscale); the color seen here has been synthesized from the colors of Mars observed by the MOC wide angle cameras and by the Viking Orbiters in the late 1970s.

NAS (Host/ARTS) IIIA to VME Modem Interface ATC Interface Hardware Manual

DOT National Transportation Integrated Search

1990-10-01

This document is reference material for personnel using the National Airspace : System (NAS) (HOST or ARTS IIIA) Air Traffic Control (ATC) Interface Subsystem. : It was originally developed to be part of the Data Link Test and Analysis System : (DATA...

The temperature dependence of atomic incorporation characteristics in growing GaInNAs films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jingling; Gao, Fangliang; Wen, Lei

We have systematically studied the temperature dependence of incorporation characteristics of nitrogen (N) and indium (In) in growing GaInNAs films. With the implementation of Monte-Carlo simulation, the low N adsorption energy (−0.10 eV) is demonstrated. To understand the atomic incorporation mechanism, temperature dependence of interactions between Group-III and V elements are subsequently discussed. We find that the In incorporation behaviors rather than that of N are more sensitive to the T{sub g}, which can be experimentally verified by exploring the compositional modulation and structural changes of the GaInNAs films by means of high-resolution X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope,more » and secondary ion mass spectroscopy.« less

Differences in Supratentorial Damage of White Matter in Pediatric Survivors of Posterior Fossa Tumors With and Without Adjuvant Treatment as Detected by Magnetic Resonance Diffusion Tensor Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rueckriegel, Stefan Mark, E-mail: stefan.rueckriegel@charite.d; Driever, Pablo Hernaiz; Blankenburg, Friederike

2010-03-01

Purpose: To elucidate morphologic correlates of brain dysfunction in pediatric survivors of posterior fossa tumors by using magnetic resonance diffusion tensor imaging (DTI) to examine neuroaxonal integrity in white matter. Patients and Methods: Seventeen medulloblastoma (MB) patients who had received surgery and adjuvant treatment, 13 pilocytic astrocytoma (PA) patients who had been treated only with surgery, and age-matched healthy control subjects underwent magnetic resonance imaging on a 3-Tesla system. High-resolution conventional T1- and T2-weighted magnetic resonance imaging and DTI data sets were obtained. Fractional anisotropy (FA) maps were analyzed using tract-based spatial statistics, a part of the Functional MRI ofmore » the Brain Software Library. Results: Compared with control subjects, FA values of MB patients were significantly decreased in the cerebellar midline structures, in the frontal lobes, and in the callosal body. Fractional anisotropy values of the PA patients were not only decreased in cerebellar hemispheric structures as expected, but also in supratentorial parts of the brain, with a distribution similar to that in MB patients. However, the amount of significantly decreased FA was greater in MB than in PA patients, underscoring the aggravating neurotoxic effect of the adjuvant treatment. Conclusions: Neurotoxic mechanisms that are present in PA patients (e.g., internal hydrocephalus and damaged cerebellar structures affecting neuronal circuits) contribute significantly to the alteration of supratentorial white matter in pediatric posterior fossa tumor patients.« less

Shadow Mode Assessment Using Realistic Technologies for the National Airspace (SMART NAS)

NASA Technical Reports Server (NTRS)

Kopardekar, Parimal H.

2014-01-01

Develop a simulation and modeling capability that includes: (a) Assessment of multiple parallel universes, (b) Accepts data feeds, (c) Allows for live virtual constructive distribute environment, (d) Enables integrated examinations of concepts, algorithms, technologies and National Airspace System (NAS) architectures.

Strain relaxation induced surface morphology of heterogeneous GaInNAs layers grown on GaAs substrate

NASA Astrophysics Data System (ADS)

Gelczuk, Ł.; Jóźwiak, G.; Moczała, M.; Dłużewski, P.; Dąbrowska-Szata, M.; Gotszalk, T. P.

2017-07-01

The partially-relaxed heterogeneous GaInNAs layers grown on GaAs substrate by atmospheric pressure vapor phase epitaxy (AP-MOVPE) were investigated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The planar-view TEM image shows a regular 2D network of misfit dislocations oriented in two orthogonal 〈1 1 0〉 crystallographic directions at the (0 0 1) layer interface. Moreover, the cross-sectional view TEM image reveals InAs-rich and V-shaped precipitates in the near surface region of the GaInNAs epitaxial layer. The resultant undulating surface morphology, known as a cross-hatch pattern, is formed as observed by AFM. The numerical analysis of the AFM image of the GaInNAs layer surface with the well-defined cross-hatch morphology enabled us to determine a lower bound of actual density of misfit dislocations. However, a close correspondence between the asymmetric distribution of interfacial misfit dislocations and undulating surface morphology is observed.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project - Systems Integration and Operationalization (SIO) Demonstration

NASA Technical Reports Server (NTRS)

Swieringa, Kurt

2018-01-01

The UAS-NAS Project hosted a Systems Integration Operationalization (SIO) Industry Day for the SIO Request for Information (RFI) on November 30, 2017 in San Diego, California. This presentation is being presented to the same group as a follow up regarding the progress that the UAS-NAS project has made on the SIO RFI. The presentation will be virtual with a teleconference

UAS Integration in the NAS Project: Integrated Test and LVC Infrastructure

NASA Technical Reports Server (NTRS)

Murphy, Jim; Hoang, Ty

2015-01-01

Overview presentation of the Integrated Test and Evaluation sub-project of the Unmanned Aircraft System (UAS) in the National Airspace System (NAS). The emphasis of the presentation is the Live, Virtual, and Constructive (LVC) system (a broadly used name for classifying modeling and simulation) infrastructure and use of external assets and connection.

Classification and Microvascular Flap Selection for Anterior Cranial Fossa Reconstruction.

PubMed

Vargo, James D; Przylecki, Wojciech; Camarata, Paul J; Andrews, Brian T

2018-05-18

 Microvascular reconstruction of the anterior cranial fossa (ACF) creates difficult challenges. Reconstructive goals and flap selection vary based on the defect location within the ACF. This study evaluates the feasibility and reliability of free tissue transfer for salvage reconstruction of low, middle, and high ACF defects.  A retrospective review was performed. Reconstructions were anatomically classified as low (anterior skull base), middle (frontal bar/sinus), and high (frontal bone/soft tissue). Subjects were evaluated based on pathologic indication and goal, type of flap used, and complications observed.  Eleven flaps in 10 subjects were identified and anatomic sites included: low ( n  = 5), middle ( n  = 3), and high ( n  = 3). Eight of 11 reconstructions utilized osteocutaneous flaps including the osteocutaneous radial forearm free flap (OCRFFF) ( n  = 7) and fibula ( n  = 1). Other reconstructions included a split calvarial graft wrapped within a temporoparietal fascia free flap ( n  = 1), latissimus myocutaneous flap ( n  = 1), and rectus abdominis myofascial flap ( n  = 1). All 11 flaps were successful without microvascular compromise. No complications were observed in the high and middle ACF defect groups. Two of five flaps in the low defect group using OCRFFF flaps failed to achieve surgical goals despite demonstrating healthy flaps upon re-exploration. Complications included persistent cerebrospinal fluid leak ( n  = 1) and pneumocephalus ( n  = 1), requiring flap repositioning in one subject and a second microvascular flap in the second subject to achieve surgical goals.  In our experience, osteocutaneous flaps (especially the OCRFFF) are preferred for complete autologous reconstruction of high and middle ACF defects. Low skull base defects are more difficult to reconstruct, and consideration of free muscle flaps (no bone) should be weighed as an option in this anatomic area. Thieme Medical Publishers

UAS Integration in the NAS Project: Flight Test 3 Data Analysis of JADEM-Autoresolver Detect and Avoid System

NASA Technical Reports Server (NTRS)

Gong, Chester; Wu, Minghong G.; Santiago, Confesor

2016-01-01

The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS Integration in the NAS, aims to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The UAS Integration in the NAS Project conducted a flight test activity, referred to as Flight Test 3 (FT3), involving several Detect-and-Avoid (DAA) research prototype systems between June 15, 2015 and August 12, 2015 at the Armstrong Flight Research Center (AFRC). This report documents the flight testing and analysis results for the NASA Ames-developed JADEM-Autoresolver DAA system, referred to as 'Autoresolver' herein. Four flight test days (June 17, 18, 22, and July 22) were dedicated to Autoresolver testing. The objectives of this test were as follows: 1. Validate CPA prediction accuracy and detect-and-avoid (DAA, formerly known as self-separation) alerting logic in realistic flight conditions. 2. Validate DAA trajectory model including maneuvers. 3. Evaluate TCAS/DAA interoperability. 4. Inform final Minimum Operating Performance Standards (MOPS). Flight test scenarios were designed to collect data to directly address the objectives 1-3. Objective 4, inform final MOPS, was a general objective applicable to the UAS in the NAS project as a whole, of which flight test is a subset. This report presents analysis results completed in support of the UAS in the NAS project FT3 data review conducted on October 20, 2015. Due to time constraints and, to a lesser extent, TCAS data collection issues, objective 3 was not evaluated in this analysis.

Reconstruction of cubital fossa skin necrosis with radial collateral artery perforator-based propeller flap (RCAP).

PubMed

Chaput, B; Gandolfi, S; Ho Quoc, C; Chavoin, J-P; Garrido, I; Grolleau, J-L

2014-02-01

In recent years, perforator flaps have become an indispensable tool for the reconstruction process. Most recently, "propeller" perforator flaps allow each perforator vessels to become a flap donor site. Once the perforator of interest is identified by acoustic Doppler, the cutaneous or fascio-cutaneous island is designed and then customized according to the principle of "perforasome". So, the flap can be rotated such a propeller, up to 180°. Ideally the donor site is self-closing, otherwise it can be grafted at the same time. Through a skin necrosis secondary to a contrast medium extravasation of the cubital fossa in a 47-year-old man, we describe the use of propeller perforator flap based on a perforator of the radial collateral artery (RCAP). The perforator was identified preoperatively by acoustic Doppler then the flap was adapted bespoke to cover the loss of substance. Ultimately, the result was very satisfying. Well experienced for lower-extremity reconstruction, perforator-based propeller flap are still few reported for upper limb. It is likely that in the future, propeller flap supersede in many indication not only free flaps and locoregional flaps but also, leaving no room for uncertainties of the vascular network, the classic random flaps. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Many-body design of highly strained GaInNAs electroabsorption modulators on GaInAs ternary substrates

NASA Astrophysics Data System (ADS)

Fujisawa, Takeshi; Arai, Masakazu; Kano, Fumiyoshi

2010-05-01

Electroabsorption in highly strained GaInAs and GaInNAs quantum wells (QWs) grown on GaInAs or quasi-GaInAs substrates is investigated by using microscopic many-body theory. The effects of various parameters, such as strain, barrier height, substrate composition, and temperature are thoroughly examined. It is shown that the value of the absorption coefficient strongly depends on the depth of the QWs under large bias electric field due to the small overlap integral of wave functions between the conduction and valence bands. The use of GaInNAs QWs makes the strain in the well layer very small. Further, the effective quantum-well depth is increased in GaInNAs QWs due to the anticrossing interaction between the conduction and N-resonant bands, making it possible to obtain larger absorption coefficient under large bias electric fields without using wide-band gap materials for barriers.

UAS Integration in the NAS Project: Detect and Avoid Display UNITED Demo

NASA Technical Reports Server (NTRS)

Roberts, Zachary

2017-01-01

This demo shows the UAS-NAS project's Vigilant Spirit Control Station developed in partnership with the U.S. Air Force Research Lab. Attendees will be able to view encounters and see how the DAA and TCAS II alerting and guidance displays are used to avoid simulated aircraft.

Performance and Scalability of the NAS Parallel Benchmarks in Java

NASA Technical Reports Server (NTRS)

Frumkin, Michael A.; Schultz, Matthew; Jin, Haoqiang; Yan, Jerry; Biegel, Bryan A. (Technical Monitor)

2002-01-01

Several features make Java an attractive choice for scientific applications. In order to gauge the applicability of Java to Computational Fluid Dynamics (CFD), we have implemented the NAS (NASA Advanced Supercomputing) Parallel Benchmarks in Java. The performance and scalability of the benchmarks point out the areas where improvement in Java compiler technology and in Java thread implementation would position Java closer to Fortran in the competition for scientific applications.

NASA UAS Integration into the NAS Project: Human Systems Integration

NASA Technical Reports Server (NTRS)

Shively, Jay

2016-01-01

This presentation provides an overview of the work the Human Systems Integration (HSI) sub-project has done on detect and avoid (DAA) displays while working on the UAS (Unmanned Aircraft System) Integration into the NAS project. The most recent simulation on DAA interoperability with Traffic Collision Avoidance System (TCAS) is discussed in the most detail. The relationship of the work to the larger UAS community and next steps are also detailed.

Minimally Invasive Exposure of the Maxillary Artery at the Anteromedial Infratemporal Fossa.

PubMed

Rodriguez Rubio, Roberto; Kola, Olivia; Tayebi Meybodi, Ali; Tabani, Halima; Feng, Xuequan; Burkhardt, Jan-Karl; Yousef, Sonia; Lawton, Michael T; Benet, Arnau

2018-04-12

The maxillary artery (MA) has been described as a reliable donor for extracranial-intracranial high-flow bypass. Existing techniques to harvest MA require brain retraction and drilling of the middle fossa (with or without a zygomatic osteotomy), carrying the potential risks of venous bleeding, injury to the branches of the maxillary or mandibular nerves, muscular transection, or temporomandibular junction disorders. To describe a novel technique to expose the MA without bony drilling and with minimal impact to surrounding structures. A conventional curvilinear incision was performed in 10 cadaveric specimens, prior to elevating the scalp to expose the zygomatic root and lateral orbital rim. The sphenozygomatic suture was followed to the anterolateral edge of the inferior orbital fissure (IOF) to locate and harvest the pterygoid segment of the MA. Topographic anatomy was assessed using surrounding landmarks and 3D Cartesian coordinates to define the surgical area. The number of visible MA branches and their lengths were recorded. The MA was successfully exposed in all specimens. This approach allowed 6 branches of MA to be exposed. The average length of exposure was 23.3 ± 8.3 mm and the average surgical area was 2.8 ± 0.9 cm2. The IOF was 11.5 ± 4.2 mm from the MA. Our technique provides landmarks to identify the distal pterygoid segment of MA as a donor for extracranial-intracranial bypasses without the need for additional craniectomies. Clear anatomical landmarks, including the sphenozygomatic suture, anterolateral edge of IOF, infraorbital artery, and the pterygomaxillary fissure defined a trajectory to efficiently localize the MA with minimal risk to surrounding structures.

Extranasopharyngeal angiofibroma: clinical and radiological presentation.

PubMed

Szymańska, Anna; Szymański, Marcin; Morshed, Kamal; Czekajska-Chehab, Elżbieta; Szczerbo-Trojanowska, Małgorzata

2013-02-01

Nasopharyngeal angiofibroma (NA) is a rare, vascular tumor affecting adolescent males. Due to aggressive local growth, skull base location and risk of profound hemorrhage, NA is a challenge for surgeons. Angiofibromas have been sporadically described in extanasopharyngeal locations. We review ten cases of extranasopharyngeal angiofibroma (ENA) and discuss the incidence, clinical presentation and management of this pathology. The group consisted of 4 males and 5 females aged 8-49. There were 7 patients with nasal angiofibroma, 1 patient with laryngeal angiofibroma, 1 patient with oral angiofibroma and another patient with infratemporal fossa tumor. In patients with nasal angiofibroma most common presenting symptoms were nasal obstruction and epistaxis. Patients with laryngeal angiofibroma suffered from mild dysphagia and patients with the infratemporal fossa tumor had painless cheek swelling. In four patients with nasal tumor computed tomography (CT) demonstrated mass with strong to intermediate contrast enhancement. In one patient with nasal tumor carotid angiography demonstrated pathological vessels without intensive tumor blush. Infratemporal fossa tumor showed intensive contrast enhancement on CT and magnetic resonance imaging (MRI) scans, and abundant vascularity on angiography. Laryngeal and oral angiofibroma required no radiological imaging. Three nasal tumors were evaluated before introduction of CT to clinical practice. All patients underwent surgery. No recurrences developed. ENAs differ significantly from NAs regarding clinical and radiological presentations. They lack typical clinical and radiological features as they develop in all age groups and in females, may be less vascularised, arise from various sites and produce a variety of symptoms.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Subcommittee Final

NASA Technical Reports Server (NTRS)

Johnson, Chuck; Griner, James H.; Hayhurst, Kelly J.; Shively, Robert J.; Consiglio, Maria; Muller, Eric; Murphy, James; Kim, Sam

2012-01-01

UAS Integration in the NAS Project overview with details from each of the subprojects. Subprojects include: Communications, Certification, Integrated Test and Evaluation, Human Systems Integration, and Separation Assurance/Sense and Avoid Interoperability.

Evaluating the Information Power Grid using the NAS Grid Benchmarks

NASA Technical Reports Server (NTRS)

VanderWijngaartm Rob F.; Frumkin, Michael A.

2004-01-01

The NAS Grid Benchmarks (NGB) are a collection of synthetic distributed applications designed to rate the performance and functionality of computational grids. We compare several implementations of the NGB to determine programmability and efficiency of NASA's Information Power Grid (IPG), whose services are mostly based on the Globus Toolkit. We report on the overheads involved in porting existing NGB reference implementations to the IPG. No changes were made to the component tasks of the NGB can still be improved.

Optimization of nas lemoore scheduling to support a growing aircraft population

DTIC Science & Technology

2017-03-01

requirements, and, without knowing the other squadrons’ flight plans , creates his or her squadron’s flight schedule. Figure 2 illustrates the process each...Lemoore, they do not communicate their flight schedules among themselves; hence, the daily flight plan generated by each squadron is independently...manual process for aircraft flight scheduling at Naval Air Station (NAS) Lemoore accommodates the independent needs of 16 fighter resident squadrons as

Efficacy of texture, shape, and intensity feature fusion for posterior-fossa tumor segmentation in MRI.

PubMed

Ahmed, Shaheen; Iftekharuddin, Khan M; Vossough, Arastoo

2011-03-01

Our previous works suggest that fractal texture feature is useful to detect pediatric brain tumor in multimodal MRI. In this study, we systematically investigate efficacy of using several different image features such as intensity, fractal texture, and level-set shape in segmentation of posterior-fossa (PF) tumor for pediatric patients. We explore effectiveness of using four different feature selection and three different segmentation techniques, respectively, to discriminate tumor regions from normal tissue in multimodal brain MRI. We further study the selective fusion of these features for improved PF tumor segmentation. Our result suggests that Kullback-Leibler divergence measure for feature ranking and selection and the expectation maximization algorithm for feature fusion and tumor segmentation offer the best results for the patient data in this study. We show that for T1 and fluid attenuation inversion recovery (FLAIR) MRI modalities, the best PF tumor segmentation is obtained using the texture feature such as multifractional Brownian motion (mBm) while that for T2 MRI is obtained by fusing level-set shape with intensity features. In multimodality fused MRI (T1, T2, and FLAIR), mBm feature offers the best PF tumor segmentation performance. We use different similarity metrics to evaluate quality and robustness of these selected features for PF tumor segmentation in MRI for ten pediatric patients.

Outcomes of urethral calculi patients in an endemic region and an undiagnosed primary fossa navicularis calculus.

PubMed

Verit, Ayhan; Savas, Murat; Ciftci, Halil; Unal, Dogan; Yeni, Ercan; Kaya, Mete

2006-02-01

Urethral calculus is a rare form of urolithiasis with an incidence lower than 0.3%. We determined the outcomes of 15 patients with urethral stone, of which 8 were pediatric, including an undiagnosed primary fossa navicularis calculus. Fifteen consecutive male patients, of whom eight were children, with urethral calculi were assessed between 2000 and 2005 with a mean of 19 months' follow-up. All stones were fusiform in shape and solitary. Acute urinary retention, interrupted or weak stream, pain (penile, urethral, perineal) and gross hematuria were the main presenting symptoms in 7 (46.7%), 4 (26.7%), 3 (20%) and 1 (6.6%) patient, respectively. Six of them had accompanying urethral pathologies such as stenosis (primary or with hypospadias) and diverticulum. Two patients were associated with upper urinary tract calculi but none of them secondary to bladder calculi. A 50-year-old patient with a primary urethral stone disease had urethral meatal stenosis accompanied by lifelong lower urinary tract symptoms. Unlike the past reports, urethral stones secondary to bladder calculi were decreasing, especially in the pediatric population. However, the pediatric patients in their first decade are still under risk secondary to the upper urinary tract calculi or the primary ones.

Dosimetry and field matching for radiotherapy to the breast and superclavicular fossa

NASA Astrophysics Data System (ADS)

Winfield, Elizabeth

Radiotherapy for early breast cancer aims to achieve local disease control and decrease loco-regional recurrence rates. Treatment may be directed to breast or chest wall alone or, include regional lymph nodes. When using tangential fields to treat the breast a separate anterior field directed to the axilla and supraclavicular fossa (SCF) is needed to treat nodal areas. The complex geometry of this region necessitates matching of adjacent radiation fields in three dimensions. The potential exists for zones of overdosage or underdosage along the match line. Cosmetic results may be compromised if treatment fields are not accurately aligned. Techniques for field matching vary between centres in the UK. A study of dosimetry across the match line region using different techniques, as reported in the multi-centre START Trial Quality Assurance (QA) programme, was undertaken. A custom-made anthropomorphic phantom was designed to assess dose distribution in three dimensions using film dosimetry. Methods with varying degrees of complexity were employed to match tangential and SCF beams. Various techniques combined half beam blocking and machine rotations to achieve geometric alignment. Matching of asymmetric beams allowed a single isocentre technique to be used. Where field matching was not undertaken a gap between tangential and SCF fields was employed. Results demonstrated differences between techniques in addition to variations within the same technique between different centres. Geometric alignment techniques produced more homogenous dose distributions in the match region than gap techniques or those techniques not correcting for field divergence. For this multi-centre assessment of match plane techniques film dosimetry used in conjunction with a breast shaped phantom provided relative dose information. This study has highlighted the difficulties of matching treatment fields to achieve homogenous dose distribution through the region of the match plane and the degree of

Human Foramen Magnum Area and Posterior Cranial Fossa Volume Growth in Relation to Cranial Base Synchondrosis Closure in the Course of Child Development.

PubMed

Coll, Guillaume; Lemaire, Jean-Jacques; Di Rocco, Federico; Barthélémy, Isabelle; Garcier, Jean-Marc; De Schlichting, Emmanuel; Sakka, Laurent

2016-11-01

To date, no study has compared the evolution of the foramen magnum area (FMA) and the posterior cranial fossa volume (PCFV) with the degree of cranial base synchondrosis ossification. To illustrate these features in healthy children. The FMA, the PCFV, and the ossification of 12 synchondroses according to the Madeline and Elster scale were retrospectively analyzed in 235 healthy children using millimeter slices on a computed tomography scan. The mean FMA of 6.49 cm in girls was significantly inferior to the FMA of 7.67 cm in boys (P < .001). In both sexes, the growth evolved in a 2-phase process, with a phase of rapid growth from birth to 3.75 years old (yo) followed by a phase of stabilization. In girls, the first phase was shorter (ending at 2.6 yo) than in boys (ending at 4.33 yo) and proceeded at a higher rate. PCFV was smaller in girls (P < .001) and displayed a biphasic pattern in the whole population, with a phase of rapid growth from birth to 3.58 yo followed by a phase of slow growth until 16 yo. In girls, the first phase was more active and shorter (ending at 2.67 yo) than in boys (ending at 4.5 yo). The posterior interoccipital synchondroses close first, followed by the anterior interoccipital and occipitomastoidal synchondroses, the lambdoid sutures simultaneously, then the petro-occipital and spheno-occipital synchondroses simultaneously. The data provide a chronology of synchondrosis closure. We showed that FMA and PCFV are constitutionally smaller in girls at birth (P ≤ .02) and suggest that a sex-related difference in the FMA is related to earlier closure of anterior interoccipital synchondroses in girls (P = .01). AIOS, anterior interoccipital synchondrosesFMA, foramen magnum areaLS, lambdoid suturesOMS, occipitomastoidal synchondrosesPCFV, posterior cranial fossa volumePIOS, posterior interoccipital synchondrosesPOS, petro-occipital synchondrosesSOS, spheno-occipital synchondrosisyo, years old.

Web Prep: How to Prepare NAS Reports For Publication on the Web

NASA Technical Reports Server (NTRS)

Walatka, Pamela; Balakrishnan, Prithika; Clucas, Jean; McCabe, R. Kevin; Felchle, Gail; Brickell, Cristy

1996-01-01

This document contains specific advice and requirements for NASA Ames Code IN authors of NAS reports. Much of the information may be of interest to other authors writing for the Web. WebPrep has a graphic Table of Contents in the form of a WebToon, which simulates a discussion between a scientist and a Web publishing consultant. In the WebToon, Frequently Asked Questions about preparing reports for the Web are linked to relevant text in the body of this document. We also provide a text-only Table of Contents. The text for this document is divided into chapters: each chapter corresponds to one frame of the WebToons. The chapter topics are: converting text to HTML, converting 2D graphic images to gif, creating imagemaps and tables, converting movie and audio files to Web formats, supplying 3D interactive data, and (briefly) JAVA capabilities. The last chapter is specifically for NAS staff authors. The Glossary-Index lists web related words and links to topics covered in the main text.

The Performance of the NAS HSPs in 1st Half of 1994

NASA Technical Reports Server (NTRS)

Bergeron, Robert J.; Walter, Howard (Technical Monitor)

1995-01-01

During the first six months of 1994, the NAS (National Airspace System) 16-CPU Y-MP C90 Von Neumann (VN) delivered an average throughput of 4.045 GFLOPS while the ACSF (Aeronautics Consolidated Supercomputer Facility) 8-CPU Y-MP C90 Eagle averaged 1.658 GFLOPS. The VN rate represents a machine efficiency of 26.3% whereas the Eagle rate corresponds to a machine efficiency of 21.6%. VN displayed a greater efficiency than Eagle primarily because the stronger workload demand for its CPU cycles allowed it to devote more time to user programs and less time to idle. An additional factor increasing VN efficiency was the ability of the UNICOS 8.0 Operating System to deliver a larger fraction of CPU time to user programs. Although measurements indicate increasing vector length for both workloads, insufficient vector lengths continue to hinder HSP (High Speed Processor) performance. To improve HSP performance, NAS should continue to encourage the HSP users to modify their codes to increase program vector length.

Fretted Terrain Valley in Coloe Fossae Region

NASA Technical Reports Server (NTRS)

2006-01-01

[figure removed for brevity, see original site] Figure 1 Click on image for larger version

The image in figure 1 shows lineated valley fill in one of a series of enclosed, intersecting troughs known as Coloe (Choloe) Fossae. Lineated valley fill consists of rows of material in valley centers that are parallel to the valley walls. It is probably made of ice-rich material and boulders that are left behind when the ice-rich material sublimates. Very distinct rows can be seen near the south (bottom) wall of the valley. Lineated valley fill is thought to result from mass wasting (downslope movement) of ice-rich material from valley walls towards their centers. It is commonly found in valleys near the crustal dichotomy that separates the two hemispheres of Mars. The valley shown here joins four other valleys with lineated fill near the top left corner of this image. Their juncture is a topographic low, suggesting that the lineated valley fill from the different valleys may be flowing or creeping towards the low area (movement towards the upper left of the image). The valley walls appear smooth at first glance but are seen to be speckled with small craters several meters in diameter at HiRISE resolution (see contrast-enhanced subimage). This indicates that at least some of the wall material has been stable to mass wasting for some period of time. Also seen on the valley wall are elongated features shaped like teardrops. These are most likely slightly older craters that have been degraded due to potentially recent downhill creep. It is unknown whether the valley walls are shedding material today. The subimage is approximately 140 x 400 m (450 x 1280 ft).

Image PSP_001372_2160 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 11, 2006. The complete image is centered at 35.5 degrees latitude, 56.8 degrees East longitude. The range to the target site was 290.3 km (181

Shallow radar (SHARAD) sounding observations of the Medusae Fossae Formation, Mars

USGS Publications Warehouse

Carter, L.M.; Campbell, B.A.; Watters, T.R.; Phillips, R.J.; Putzig, N.E.; Safaeinili, A.; Plaut, J.J.; Okubo, C.H.; Egan, A.F.; Seu, R.; Biccari, D.; Orosei, R.

2009-01-01

The SHARAD (shallow radar) sounding radar on the Mars Reconnaissance Orbiter detects subsurface reflections in the eastern and western parts of the Medusae Fossae Formation (MFF). The radar waves penetrate up to 580 m of the MFF and detect clear subsurface interfaces in two locations: west MFF between 150 and 155?? E and east MFF between 209 and 213?? E. Analysis of SHARAD radargrams suggests that the real part of the permittivity is ???3.0, which falls within the range of permittivity values inferred from MARSIS data for thicker parts of the MFF. The SHARAD data cannot uniquely determine the composition of the MFF material, but the low permittivity implies that the upper few hundred meters of the MFF material has a high porosity. One possibility is that the MFF is comprised of low-density welded or interlocked pyroclastic deposits that are capable of sustaining the steep-sided yardangs and ridges seen in imagery. The SHARAD surface echo power across the MFF is low relative to typical martian plains, and completely disappears in parts of the east MFF that correspond to the radar-dark Stealth region. These areas are extremely rough at centimeter to meter scales, and the lack of echo power is most likely due to a combination of surface roughness and a low near-surface permittivity that reduces the echo strength from any locally flat regions. There is also no radar evidence for internal layering in any of the SHARAD data for the MFF, despite the fact that tens-of-meters scale layering is apparent in infrared and visible wavelength images of nearby areas. These interfaces may not be detected in SHARAD data if their permittivity contrasts are low, or if the layers are discontinuous. The lack of closely spaced internal radar reflectors suggests that the MFF is not an equatorial analog to the current martian polar deposits, which show clear evidence of multiple internal layers in SHARAD data. ?? 2008 Elsevier Inc.

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2010 CFR

2010-10-01

...-conditioning system (Specified under 600 Sections) 5 Entire boiler plant system (Specified under 700 Sections... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Payments under fixed-price construction contracts (without NAS). 852.236-82 Section 852.236-82 Federal Acquisition Regulations System...

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2010 CFR

2010-10-01

... (cold, constant temperature) 5 Entire air-conditioning system (Specified under 600 Sections) 5 Entire... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Payments under fixed-price construction contracts (including NAS). 852.236-83 Section 852.236-83 Federal Acquisition Regulations System...

NAS Decadal Review Town Hall

NASA Astrophysics Data System (ADS)

The National Academies of Sciences, Engineering and Medicine is seeking community input for a study on the future of materials research (MR). Frontiers of Materials Research: A Decadal Survey will look at defining the frontiers of materials research ranging from traditional materials science and engineering to condensed matter physics. Please join members of the study committee for a town hall to discuss future directions for materials research in the United States in the context of worldwide efforts. In particular, input on the following topics will be of great value: progress, achievements, and principal changes in the R&D landscape over the past decade; identification of key MR areas that have major scientific gaps or offer promising investment opportunities from 2020-2030; and the challenges that MR may face over the next decade and how those challenges might be addressed. This study was requested by the Department of Energy and the National Science Foundation. The National Academies will issue a report in 2018 that will offer guidance to federal agencies that support materials research, science policymakers, and researchers in materials research and other adjoining fields. Learn more about the study at http://nas.edu/materials.

Pressure and PL study of dilute-N GaInNAs films for applications in photovoltaics

NASA Astrophysics Data System (ADS)

Lindberg, George; Fukuda, Miwa; Al Khalfioui, M.; Hossain, Khalid; Sellers, Ian; Weinstein, Bernard

2013-03-01

Multi-junction photovoltaic devices employing dilute-N GaInNAs alloys are currently of high interest for efficient solar energy conversion. The negative band-bowing produced by introducing a few percent N into GaInAs provides a convenient way to match the 1eV component of the solar spectrum, providing recombination losses in localized states can be reduced while maintaining favorable carrier extraction. High pressure photoluminescence (PL) experiments exploring the localization of band-edge excitons in dilute-N GaInNAs films grown by plasma assisted MBE will be discussed. The effects of post-growth annealing and hydrogen incorporation on the PL spectra of the films are considered. Research supported by Amethyst Research Inc. through the State of Oklahoma, ONAP program.

Room-temperature electron spin amplifier based on Ga(In)NAs alloys.

PubMed

Puttisong, Yuttapoom; Buyanova, Irina A; Ptak, Aaron J; Tu, Charles W; Geelhaar, Lutz; Riechert, Henning; Chen, Weimin M

2013-02-06

The first experimental demonstration of a spin amplifier at room temperature is presented. An efficient, defect-enabled spin amplifier based on a non-magnetic semiconductor, Ga(In)NAs, is proposed and demonstrated, with a large spin gain (up to 2700% at zero field) for conduction electrons and a high cut-off frequency of up to 1 GHz. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Brain Perfusion and Diffusion Abnormalities in Children Treated for Posterior Fossa Brain Tumors.

PubMed

Li, Matthew D; Forkert, Nils D; Kundu, Palak; Ambler, Cheryl; Lober, Robert M; Burns, Terry C; Barnes, Patrick D; Gibbs, Iris C; Grant, Gerald A; Fisher, Paul G; Cheshier, Samuel H; Campen, Cynthia J; Monje, Michelle; Yeom, Kristen W

2017-06-01

To compare cerebral perfusion and diffusion in survivors of childhood posterior fossa brain tumor with neurologically normal controls and correlate differences with cognitive dysfunction. We analyzed retrospectively arterial spin-labeled cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) in 21 patients with medulloblastoma (MB), 18 patients with pilocytic astrocytoma (PA), and 64 neurologically normal children. We generated ANCOVA models to evaluate treatment effects on the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, and cerebral white matter at time points an average of 5.7 years after original diagnosis. A retrospective review of patient charts identified 12 patients with neurocognitive data and in whom the relationship between IQ and magnetic resonance imaging variables was assessed for each brain structure. Patients with MB (all treated with surgery, chemotherapy, and radiation) had significantly lower global CBF relative to controls (10%-23% lower, varying by anatomic region, all adjusted P?

Immunohistochemical analysis of H3K27me3 demonstrates global reduction in group-A childhood posterior fossa ependymoma and is a powerful predictor of outcome.

PubMed

Panwalkar, Pooja; Clark, Jonathan; Ramaswamy, Vijay; Hawes, Debra; Yang, Fusheng; Dunham, Christopher; Yip, Stephen; Hukin, Juliette; Sun, Yilun; Schipper, Matthew J; Chavez, Lukas; Margol, Ashley; Pekmezci, Melike; Chung, Chan; Banda, Adam; Bayliss, Jill M; Curry, Sarah J; Santi, Mariarita; Rodriguez, Fausto J; Snuderl, Matija; Karajannis, Matthias A; Saratsis, Amanda M; Horbinski, Craig M; Carret, Anne-Sophie; Wilson, Beverly; Johnston, Donna; Lafay-Cousin, Lucie; Zelcer, Shayna; Eisenstat, David; Silva, Marianna; Scheinemann, Katrin; Jabado, Nada; McNeely, P Daniel; Kool, Marcel; Pfister, Stefan M; Taylor, Michael D; Hawkins, Cynthia; Korshunov, Andrey; Judkins, Alexander R; Venneti, Sriram

2017-11-01

Posterior fossa ependymomas (EPN_PF) in children comprise two morphologically identical, but biologically distinct tumor entities. Group-A (EPN_PFA) tumors have a poor prognosis and require intensive therapy. In contrast, group-B tumors (EPN_PFB) exhibit excellent prognosis and the current consensus opinion recommends future clinical trials to test the possibility of treatment de-escalation in these patients. Therefore, distinguishing these two tumor subtypes is critical. EPN_PFA and EPN_PFB can be distinguished based on DNA methylation signatures, but these assays are not routinely available. We have previously shown that a subset of poorly prognostic childhood EPN_PF exhibits global reduction in H3K27me3. Therefore, we set out to determine whether a simple immunohistochemical assay for H3K27me3 could be used to segregate EPN_PFA from EPN_PFB tumors. We assembled a cohort of 230 childhood ependymomas and H3K27me3 immunohistochemistry was assessed as positive or negative in a blinded manner. H3K27me3 staining results were compared with DNA methylation-based subgroup information available in 112 samples [EPN_PFA (n = 72) and EPN_PFB tumors (n = 40)]. H3K27me3 staining was globally reduced in EPN_PFA tumors and immunohistochemistry showed 99% sensitivity and 100% specificity in segregating EPN_PFA from EPN_PFB tumors. Moreover, H3K27me3 immunostaining was sufficient to delineate patients with worse prognosis in two independent, non-overlapping cohorts (n = 133 and n = 97). In conclusion, immunohistochemical evaluation of H3K27me3 global reduction is an economic, easily available and readily adaptable method for defining high-risk EPN_PFA from low-risk posterior fossa EPN_PFB tumors to inform prognosis and to enable the design of future clinical trials.

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2013 CFR

2013-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2011 CFR

2011-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2012 CFR

2012-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

48 CFR 852.236-82 - Payments under fixed-price construction contracts (without NAS).

Code of Federal Regulations, 2014 CFR

2014-10-01

... “Network Analysis System (NAS).” Payments Under Fixed-Price Construction Contracts (APR 1984) The clause..., as applied to each branch, shall equal the total cost of such branch. The total cost of all branches... readily available for inspection and inventory by the resident engineer. (4) Such materials and/or...

[Teratoma of the rhinopharynx and the infratemporal fossa in neonates: report of 3 cases].

PubMed

Benlyazid, A; Lescanne, E; Marque, A; Robier, A; Beutter, P; Ployet, M J

2001-02-01

Teratomas are tumors which develop in childhood or early adulthood, generally in the gonads. More rarely these tumors may be found in an axial localization, notably in cervicofacial forms. We report three cases of teratomas observed in rhinopharynx of three neonates operated at the Clocheville General Hospital. We present the main anatomoclinical features of these tumors, focusing on the cervicofacial forms in neonates. All three cases occurred in female neonates presenting acute dyspnea within the first hours of life, requiring intubation in two cases. The first two tumors invaded the infratemoral region and the third was a pediculated tumor of the velum exteriorized via the mouth. In one case antenatal ultrasound had suggested the diagnosis of a right temporomaxillary tumor. Rapid excision of the rhinopharngyeal component allow extubation for the two intubated infants and pathology diagnosis. In the first infant operated at 2 months, the lateral route was adapted to age, with mandibulotomy with section of the coronoid process but preserving the mandibular condyle. The second infant was operated at the age of 3 weeks using a wide frontotemporoperitonial approach then at the age of 3.5 months for recurrence extending to the floor of the temporal fossa and the middle ear. A type C infratemporal approach was used with lost-bone temporal craniectomy. Per-buccal excision was possible in the third infant with resection at the base of implantation. No recurrence has been observed in the first two cases at 3.5 and 2.5 months follow-up in the first two cases. The third infant was lost to follow-up.

Posterior fossa volume and response to suboccipital decompression in patients with Chiari I malformation.

PubMed

Badie, B; Mendoza, D; Batzdorf, U

1995-08-01

Smaller posterior fossa (PF) volume has been suggested to be one of the mechanisms responsible for tonsillar herniation through the foramen magnum in patients with Chiari I malformation (CM I). Although previous radiological analyses of the cranial anatomy have suggested a smaller PF volume in patients with CM I, the relationship of the PF volume to decompressive surgery has not been reported. We have measured the ratio of PF volume to supratentorial volume (PF ratio [PFR]) in 20 patients with CM I and 20 control patients by retrospectively studying their magnetic resonance images with a computerized image analyzer. The mean PFR in patients with CM I (with or without syringomyelia) was significantly smaller than for those in the control group (15.6 +/- 1.9 versus 17.5 +/- 1.2, P = 0.0008). Although PFR did not correlate with the extent of tonsillar herniation in patients with CM I, it did directly correlate with their age, i.e., younger patients with CM I (but not control patients) had smaller PFRs. All but three patients responded both clinically and radiographically to decompressive surgery. Those patients who did not benefit from surgical intervention had normal PFRs. We conclude that: 1) PFRs are smaller in most patients with CM I; 2) a smaller PF may be a primary cause of tonsillar herniation; 3) patients with CM I who have smaller PFRs tend to develop symptoms earlier than those with normal values; 4) patients with smaller PFRs tend to respond better to suboccipital decompression.

Volcanic emissions from soils at the base of La Fossa volcano, Vulcano island, Italy

NASA Astrophysics Data System (ADS)

Obenholzner, J. H.; Parks, J. L.

2006-12-01

A top-sealed plastic tube with a diameter of ca. 15 cm had been buried vertically at the base of La Fossa volcano, Volcano island, Italy, next to the front of the obsidian flow. The tube had been filled with quartz wool to condense vapors emanating from the soil. At ca. 75 cm below the surface the sample had been exposed to vapors from Sept. 2005 to April 2006. The leached sample had not been in touch with the ground. Another glass wool cushion (ca. 3 cm thick) had been underneath to minimize capillary effects. Leaching of the quartz wool and ICP-MS analysis documented positive values for: Mg, Al, Si, P, K, Ca, Cr, Mn, Ni, Cu, Zn, Cd, Sn, Pb. Leaching with nitric acid documented also V and Fe. Acid leaching produced higher values for all elements, except K and Sn, than leaching with deionized water. Negative values had been obtained for As, Se, Mo. Influence from soil breathing can be excluded as the active fumaroles contain As and Se. This experiment documents for the first time an unknown element transport by vapors/gases through a volcanic edifice interacting with hydrothermal and magmatic gases. It remains unknown if elements detected are entering the atmosphere or are getting adsorbed onto the volcanic ash soil particles derived from reworked surge beds. This question is very important as soils might be an unknown filter medium to filter volcanically polluted air in case of major volcanic crises. Data can be obtained from the authors.

Cratered cones in Southern Cerberus Palus, Mars: Evidence for phreatovolcanism associated with interactions between Amazonian aged lavas and the Medusae Fossae Formation

NASA Astrophysics Data System (ADS)

Stacey, K.; Kerber, L.

2017-12-01

Abundant cratered cones have been identified in Southern Cerberus Palus where young, Cerberus Fossae-derived lavas interact with Medusae Fossae Formation (MFF) materials from Aeolis Planum and Zephyria Planum. These regions contain cones analogous to Icelandic pseudocraters, but the cones display characteristics that differentiate them from others that have been previously described elsewhere on Mars. The cones in this study are found abutting the MFF border, where yardang fleets are embayed by Cerberus lavas, and within flood lavas that overlie MFF deposits west of Zephyria Planum. Rootless cones have formerly been observed in areas of Athabasca Valles, Amazonis Planitia, Elysium Planitia, and Marte Valles. Using HiRISE and CTX imagery from the Mars Reconnaissance Orbiter, Southern Cerberus Palus cones are observed to preferentially form along the tops of partially and fully embayed yardangs. In addition, the cones often form in circular groups atop impact crater rims, and occasionally have large cracks along their flanks. Some cones are also found in linear chains along fissures of obscured origins. Several of these attributes have been noted in previous studies of Martian cratered cones and interpreted as a result of unusual contact geometries with the substrate and a tendency to form at topographic highs, where overburden pressures are minimal (Jaeger et al 2007). Surrounding many cones are areas of light colored, smooth material with lobate margins, below the level of the neighboring rubbly lava. The surface texture of this material is similar to the smooth, polygonally fractured material often found in rifts between Cerberus lava plates, but do not appear to result from tearing in the surrounding lava surface, as they have no preferred size or direction. Due to their overall morphology and distribution, the cones in this study are interpreted to most likely be rootless, hydrovolcanic features formed by explosive interactions between lava flows and H2O present

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2013 CFR

2013-10-01

... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2014 CFR

2014-10-01

... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

48 CFR 852.236-83 - Payments under fixed-price construction contracts (including NAS).

Code of Federal Regulations, 2012 CFR

2012-10-01

... shall show on the critical path method (CPM) network the total cost of the guarantee period services in... prescribed in 832.111, insert the following clause in contracts that contain a section entitled “Network...) Failure either to meet schedules in Section Network Analysis System (NAS), or to process the Interim Arrow...

[Dermoid cysts of the posterior cerebral fossa in children revealed by recurrent aseptic meningitis: Report of two cases and a review of the literature].

PubMed

Kouadria, R; Derkaoui, M

2018-03-01

Dermoid cysts of central nervous system are very rare. The usual clinical presentation is dominated by intracranial hypertension, epilepsy and cranial palsy. The revelation mode could be recurrent aseptic meningitis. The aim of this case report is to consider the dermoid cyst as regards the differential diagnosis in children treated for recurrent aseptic meningitis to avoid misdiagnosis and ice qui a orienté le diagnostic à une méningitnadequate treatment. Two children were admitted in the pediatric department for recurrent aseptic meningitis. The MRI confirmed the presence of a posterior fossa dermoid cyst. Loss of meningitis after microsurgical resection. The diagnosis of dermoid cyst is performed and reconsidered at an early stage in aseptic meningitis in order to establish an adequate therapy, which is surgery. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Retrospective comparison of three-dimensional imaging sequences in the visualization of posterior fossa cranial nerves.

PubMed

Ors, Suna; Inci, Ercan; Turkay, Rustu; Kokurcan, Atilla; Hocaoglu, Elif

2017-12-01

To compare efficancy of three-dimentional SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolutions) and CISS (constructive interference in steady state) sequences in the imaging of the cisternal segments of cranial nerves V-XII. Temporal MRI scans from 50 patients (F:M ratio, 27:23; mean age, 44.5±15.9 years) admitted to our hospital with vertigo, tinnitus, and hearing loss were retrospectively analyzed. All patients had both CISS and SPACE sequences. Quantitative analysis of SPACE and CISS sequences was performed by measuring the ventricle-to-parenchyma contrast-to-noise ratio (CNR). Qualitative analysis of differences in visualization capability, image quality, and severity of artifacts was also conducted. A score ranging 'no artefact' to 'severe artefacts and unreadable' was used for the assessment of artifacts and from 'not visualized' to 'completely visualized' for the assesment of image quality, respectively. The distribution of variables was controlled by the Kolmogorov-Smirnov test. Samples t-test and McNemar's test were used to determine statistical significance. Rates of visualization of posterior fossa cranial nerves in cases of complete visualization were as follows: nerve V (100% for both sequences), nerve VI (94% in SPACE, 86% in CISS sequences), nerves VII-VIII (100% for both sequences), IX-XI nerve complex (96%, 88%); nerve XII (58%, 46%) (p<0.05). SPACE sequences showed fewer artifacts than CISS sequences (p<0.002). Copyright © 2017 Elsevier B.V. All rights reserved.

Medusae Fossae-Elysium Region, Mars: Depression in the HEND/Odyssey Map of Mars Epithermal Neutrons

NASA Technical Reports Server (NTRS)

Ivanov, M. A.; Litvak, M. L.; Mitrofanov, I. G.; Boynton, W.; Saunders, R. S.

2003-01-01

The first data from the Gamma Ray Spectrometer (GRS) onboard Mars Odyssey spacecraft showed that the low neutron fluxes characterize both subpolar regions of Mars. The low neutron fluxes mean the presence of hydrogen-rich soils and have been interpreted as an indication on abundant water ice in these areas. The equatorial region of Mars (equatorward of approx. 50 deg) is characterized by higher fluxes of both epithermal (0.4 eV-100 keV, come from depth 1-2 m) and fast (3.4-7.3 MeV, come from depth 0.2-0.3 m) neutrons meaning that this area is mostly dry. The pattern of distribution of the neutron fluxes is in a good agreement with the theoretical predictions on the stability of ground ice on present Mars. The actual distribution of the ice, however, depends on variations of thermal inertia of soils and albedo of the surface. The flux of the epithermal neutrons detected by the HEND instrument, which is part of GRS, has two noticeable depressions in the equatorial region, one in Arabia Terra and another in the Medusae Fossae-Elysium region (MFER). Here we present the initial results of analysis of characteristics of the neutron fluxes and regional geological setting of the epithermal neutron depression in this area. The main goal of our study was to put some constraints on the time of the anomaly formation and to assess possible form of hydrogen (ground ice vs. chemically bound water) there.

Macroscopic Innervation of the Dura Mater Covering the Middle Cranial Fossa in Humans Correlated to Neurovascular Headache

PubMed Central

Lee, Shin-Hyo; Hwang, Seung-Jun; Koh, Ki-Seok; Song, Wu-Chul; Han, Sang-Don

2017-01-01

The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA) in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler’s method. Overall, the nervus spinosus (NS) from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases (N = 36). Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%). The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%). These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion. PMID:29311855

Macroscopic Innervation of the Dura Mater Covering the Middle Cranial Fossa in Humans Correlated to Neurovascular Headache.

PubMed

Lee, Shin-Hyo; Hwang, Seung-Jun; Koh, Ki-Seok; Song, Wu-Chul; Han, Sang-Don

2017-01-01

The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA) in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler's method. Overall, the nervus spinosus (NS) from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases ( N = 36). Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%). The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%). These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion.

Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package: Automation Impacts of ROA's in the NAS

NASA Technical Reports Server (NTRS)

2005-01-01

The purpose of this document is to analyze the impact of Remotely Operated Aircraft (ROA) operations on current and planned Air Traffic Control (ATC) automation systems in the En Route, Terminal, and Traffic Flow Management domains. The operational aspects of ROA flight, while similar, are not entirely identical to their manned counterparts and may not have been considered within the time-horizons of the automation tools. This analysis was performed to determine if flight characteristics of ROAs would be compatible with current and future NAS automation tools. Improvements to existing systems / processes are recommended that would give Air Traffic Controllers an indication that a particular aircraft is an ROA and modifications to IFR flight plan processing algorithms and / or designation of airspace where an ROA will be operating for long periods of time.

Validation of the nursing workload scoring systems "Nursing Activities Score" (NAS), and "Therapeutic Intervention Scoring System For Critically Ill Children" (TISS-C) in a Greek Paediatric Intensive Care Unit.

PubMed

Nieri, Alexandra-Stavroula; Manousaki, Kalliopi; Kalafati, Maria; Padilha, Katia Grilio; Stafseth, Siv K; Katsoulas, Theodoros; Matziou, Vasiliki; Giannakopoulou, Margarita

2018-04-11

To assess the reliability and validity of the Greek version of Nursing Activities Score (NAS), and Therapeutic Intervention Scoring System for Critically Ill Children (TISS-C) in a Greek Paediatric Intensive Care Unit (PICU). A methodological study was performed in one PICU of the largest Paediatric Hospital in Athens-Greece. The culturally adapted and validated Greek NAS version, enriched according to the Norwegian paediatric one (P-NAS), was used. TISS-C and Norwegian paediatric interventions were translated to Greek language and backwards. Therapeutic Intervention Scoring System (TISS-28) was used as a gold standard. Two independent observers simultaneously recorded 30 daily P-NAS and TISS-C records. Totally, 188 daily P-NAS, TISS-C and TISS-28 reports in a sample of 29 patients have been obtained during 5 weeks. Descriptive statistics, reliability and validity measures were applied using SPSS (ver 22.0) (p ≤ 0.05). Kappa was 0.963 for P-NAS and 0.9895 for TISS-C (p < 0.001) and Intraclass Correlation Coefficient for all scale items of TISS-C was 1.00 (p < 0.001). P-NAS, TISS-28 and TISS-C measurements were significantly correlated (0.680 ≤ rho ≤ 0.743, p < 0.001). The mean score(±SD) for TISS-28, P-NAS and TISS-C was 23.05(±5.72), 58.14(±13.98) and 20.21(±9.66) respectively. These results support the validity of P-NAS and TISS-C scales to be used in Greek PICUs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Navigation in Grid Space with the NAS Grid Benchmarks

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Hood, Robert; Biegel, Bryan A. (Technical Monitor)

2002-01-01

We present a navigational tool for computational grids. The navigational process is based on measuring the grid characteristics with the NAS Grid Benchmarks (NGB) and using the measurements to assign tasks of a grid application to the grid machines. The tool allows the user to explore the grid space and to navigate the execution at a grid application to minimize its turnaround time. We introduce the notion of gridscape as a user view of the grid and show how it can be me assured by NGB, Then we demonstrate how the gridscape can be used with two different schedulers to navigate a grid application through a rudimentary grid.

NASA's UAS Integration into the NAS: A Report on the Human Systems Integration Phase 1 Simulation Activities

NASA Technical Reports Server (NTRS)

Fern, Lisa; Rorie, R. Conrad; Shively, R. Jay

2014-01-01

In 2011 the National Aeronautics and Space Administration (NASA) began a five-year Project to address the technical barriers related to routine access of Unmanned Aerial Systems (UAS) in the National Airspace System (NAS). Planned in two phases, the goal of the first phase was to lay the foundations for the Project by identifying those barriers and key issues to be addressed to achieve integration. Phase 1 activities were completed two years into the five-year Project. The purpose of this paper is to review activities within the Human Systems Integration (HSI) subproject in Phase 1 toward its two objectives: 1) develop GCS guidelines for routine UAS access to the NAS, and 2) develop a prototype display suite within an existing Ground Control Station (GCS). The first objective directly addresses a critical barrier for UAS integration into the NAS - a lack of GCS design standards or requirements. First, the paper describes the initial development of a prototype GCS display suite and supporting simulation software capabilities. Then, three simulation experiments utilizing this simulation architecture are summarized. The first experiment sought to determine a baseline performance of UAS pilots operating in civil airspace under current instrument flight rules for manned aircraft. The second experiment examined the effect of currently employed UAS contingency procedures on Air Traffic Control (ATC) participants. The third experiment compared three GCS command and control interfaces on UAS pilot response times in compliance with ATC clearances. The authors discuss how the results of these and future simulation and flight-testing activities contribute to the development of GCS guidelines to support the safe integration of UAS into the NAS. Finally, the planned activities for Phase 2, including an integrated human-in-the-loop simulation and two flight tests are briefly described.

Merging field mapping and numerical simulation to interpret the lithofacies variations from unsteady pyroclastic density currents on uneven terrain: The case of La Fossa di Vulcano (Aeolian Islands, Italy)

NASA Astrophysics Data System (ADS)

Doronzo, Domenico M.; Dellino, Pierfrancesco; Sulpizio, Roberto; Lucchi, Federico

2017-01-01

In order to obtain results from computer simulations of explosive volcanic eruptions, one either needs a statistical approach to test a wide range of initial and boundary conditions, or needs using a well-constrained field case study via stratigraphy. Here we followed the second approach, using data obtained from field mapping of the Grotta dei Palizzi 2 pyroclastic deposits (Vulcano Island, Italy) as input for numerical modeling. This case study deals with impulsive phreatomagmatic explosions of La Fossa Cone that generated ash-rich pyroclastic density currents, interacting with the topographic high of the La Fossa Caldera rim. One of the simplifications in dealing with well-sorted ash (one particle size in the model) is to highlight the topographic effects on the same pyroclastic material in an unsteady current. We demonstrate that by merging field data with 3D numerical simulation results it is possible to see key details of the dynamical current-terrain interaction, and to interpret the lithofacies variations of the associated deposits as a function of topography-induced sedimentation (settling) rate. Results suggest that a value of the sedimentation rate lower than 5 kg/m2 s at the bed load can still be sheared by the overlying current, producing tractional structures (laminae) in the deposits. Instead, a sedimentation rate higher than that threshold can preclude the formation of tractional structures, producing thicker massive deposits. We think that the approach used in this study could be applied to other case studies (both for active and ancient volcanoes) to confirm or refine such threshold value of the sedimentation rate, which is to be considered as an upper value as for the limitations of the numerical model.

A Peek into a Cul-De-Sac and a Mews of Martian Dust Storm Activity: Western Hellas and Syria-Claritas Fossae During Mars Year 29

NASA Astrophysics Data System (ADS)

Heavens, N. G.

2016-12-01

Western Hellas Planitia (WHP) and the region encompassed by Syria Planum and Claritas Fossae are the main centers of textured dust storm activity in Mars's southern low to mid-latitudes. (Texture in this context refers to distinct fine structure at the cloud tops indicative of active lifting.) WHP is a well-known initiation zone for regional and global dust storm activity and often the end point of the Utopia "flushing storm" track. Syria-Claritas Fossae (SCF), too, can be a lifting center in global dust storm activity. Indeed, SCF and the area to its west was the region most denuded of dust by the Mars Year (MY) 25 global dust storm, perhaps suggesting that SCF contained the principal lifting center of the storm. Thus, if the Acidalia and Utopia storm tracks are Mars's dust storm alleys, through which dust storms pass quickly again and again; WHP might be a cul-de-sac and SCF something like a mews, where dust storm activity can enter more or less easily but may not as easily leave. In this presentation, I will focus on dust storm activity in these areas in a typical non-global dust storm year, MY 29. Synthesizing visible imagery by the Mars Color Imager (MARCI) on board Mars Reconnaissance Orbiter (MRO) and Mars Climate Sounder (MCS) also on board MRO, I will consider the climatology, morphology, texture, and vertical structure of dust storm activity in these areas in order to infer their governing dynamics. This investigation has two aims: (1) to understand why these areas are centers of textured dust storm activity; and (2) to connect the characteristics of smaller-scale dust storm activity in these regions to the underlying dynamics in order to understand the role of WHP and SCF in the dynamics of global dust storms. This work is supported by NASA's Mars Data Analysis Program (NNX14AM32G).

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

NASA Technical Reports Server (NTRS)

Griner, James H.

2013-01-01

NASA's UAS Integration in the NAS project, has partnered with Rockwell Collins to develop a concept Control and Non-Payload Communication system prototype radio, operating on recently allocated UAS frequency spectrum bands. The prototype radio will be used to validate initial proposed performance requirements for UAS control communications. This presentation will give an overview of the current status of the design, development, and flight test planning for this prototype radio.

Enhancement of photoluminescence from GaInNAsSb quantum wells upon annealing: improvement of material quality and carrier collection by the quantum well.

PubMed

Baranowski, M; Kudrawiec, R; Latkowska, M; Syperek, M; Misiewicz, J; Sarmiento, T; Harris, J S

2013-02-13

In this study we apply time resolved photoluminescence and contactless electroreflectance to study the carrier collection efficiency of a GaInNAsSb/GaAs quantum well (QW). We show that the enhancement of photoluminescence from GaInNAsSb quantum wells annealed at different temperatures originates not only from (i) the improvement of the optical quality of the GaInNAsSb material (i.e., removal of point defects, which are the source of nonradiative recombination) but it is also affected by (ii) the improvement of carrier collection by the QW region. The total PL efficiency is the product of these two factors, for which the optimal annealing temperatures are found to be ~700 °C and ~760 °C, respectively, whereas the optimal annealing temperature for the integrated PL intensity is found to be between the two temperatures and equals ~720 °C. We connect the variation of the carrier collection efficiency with the modification of the band bending conditions in the investigated structure due to the Fermi level shift in the GaInNAsSb layer after annealing.

Ultramicroporous Carbon through an Activation-Free Approach for Li-S and Na-S Batteries in Carbonate-Based Electrolyte.

PubMed

Hu, Lei; Lu, Yue; Zhang, Tianwen; Huang, Tao; Zhu, Yongchun; Qian, Yitai

2017-04-26

We report an activation-free approach for fabricating ultramicroporous carbon as an accommodation of sulfur molecules for Li-S and Na-S batteries applications in carbonate-based electrolyte. Because of the high specific surface area of 967 m 2 g -1 , as well as 51.8% of the pore volume is contributed by ultramicropore with pore size less than 0.7 nm, sulfur cathode exhibits superior electrochemical behavior in carbonate-based electrolyte with a capacity of 507.9 mA h g -1 after 500 cycles at 2 C in Li-S batteries and 392 mA h g -1 after 200 cycles at 1 C in Na-S batteries, respectively.

The OpenMP Implementation of NAS Parallel Benchmarks and its Performance

NASA Technical Reports Server (NTRS)

Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry

1999-01-01

As the new ccNUMA architecture became popular in recent years, parallel programming with compiler directives on these machines has evolved to accommodate new needs. In this study, we examine the effectiveness of OpenMP directives for parallelizing the NAS Parallel Benchmarks. Implementation details will be discussed and performance will be compared with the MPI implementation. We have demonstrated that OpenMP can achieve very good results for parallelization on a shared memory system, but effective use of memory and cache is very important.

Systematic Review of Endoscopic Obliteration Techniques for Managing Congenital Piriform Fossa Sinus Tracts in Children.

PubMed

Lachance, Sophie; Chadha, Neil K

2016-02-01

Piriform fossa sinus tracts (PFSTs) are a recognized cause of recurrent deep neck infections in the pediatric population. Conventional management has historically required open resection, but over recent years minimally invasive endoscopic approaches to obliterate the pharyngeal opening of the sinus have been performed in many centers. However, there is a lack of clear evidence regarding the success rate and safety of these approaches. To determine the success rate of endoscopic management of PFST through a systematic review of the existing literature. MEDLINE (1964-2014) and bibliographies of identified papers. Two authors independently reviewed 170 abstracts and identified relevant studies for full-text review. Data were independently extracted from those studies, and the Oxford Centre for Evidence-Based Medicine guidelines were used to classify the level of evidence. Thirteen studies met the inclusion criteria, comprising a total of 84 patients. All included studies were evidence level 4 (case series). Various methods of obliterating the PFST were described: electrocautery (n = 39), laser (n = 19), trichloroacetic acid (n = 19), silver nitrate (n = 4), combination of silver nitrate and laser (n = 2), and fibrin glue (n = 1). The success rate for endoscopic management of PFST was 89.3% overall (90.5% in primary cases and 85.7% in revision cases). The only adverse event reported was temporary vocal cord immobility in 2.4% (n = 2) of cases. Endoscopic management of pediatric PFST appears to be safe and effective, as a primary option and for revision after open surgery. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Partial maxillectomy for ameloblastoma of the maxilla with infratemporal fossa involvement: A combined endoscopic endonasal and transoral approach.

PubMed

Guha, A; Hart, L; Polachova, H; Chovanec, M; Schalek, P

2018-02-21

Ameloblastoma represents the most common epithelial odontogenic tumor. Because of the proximity of the maxillary tumors to the orbit and skull base, it should be managed as radically as possible. Maxillectomy, mainly via the transfacial or transoral approach, represents the most common type of surgical procedure. Drawback of these approaches is limited control of the superiomedial extent of the tumour in the paranasal area. We report the use of a combined endoscopic endonasal and transoral approach to manage maxillary plexiform ameloblastoma in a 48-year-old male patient. A combined endoscopic endonasal and transoral approach enabled the radical removal of tumour with a 1.5cm margin of radiographically intact bone with good control from both intrasinusal and intraoral aspects. Adequate visualization of the extent of the lesion (e.g. orbit, infratemporal fossa, anterior cranial base) had been achieved. Non-complicated healing was achieved. This technique of partial maxillectomy led to very good aesthetic and functional results. No recurrence had been noted during review appointments. The combination of endoscopic endonasal and transoral approach for a partial maxillectomy allows sufficient reduction of the defect, thus eliminating the necessity for reconstruction and reducing the morbidity associated with it. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: KDP-A for Phase 2 Minimum Operational Performance Standards

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Hackenberg, Davis L.

2016-01-01

UAS Integration in the NAS Project has: a) Developed Technical Challenges that are crucial to UAS integration, aligned with NASA's Strategic Plan and Thrusts, and support FAA standards development. b) Demonstrated rigorous project management processes through the execution of previous phases. c) Defined Partnership Plans. d) Established path to KDP-C. Request approval of Technical Challenges, execution of partnerships and plans, and execution of near-term FY17 activities. There is an increasing need to fly UAS in the NAS to perform missions of vital importance to National Security and Defense, Emergency Management, and Science. There is also an emerging need to enable commercial applications such as cargo transport (e.g. FedEx). Unencumbered NAS Access for Civil/Commercial UAS. Provide research findings, utilizing simulation and flight tests, to support the development and validation of DAA and C2 technologies necessary for integrating Unmanned Aircraft Systems into the National Airspace System.

Middle cranial fossa approach for the repair of spontaneous cerebrospinal fluid leaks to the middle ear.

PubMed

Altuna, Xabier; Navarro, Juan José; García, Leire; Ugarte, Ane; Thomas, Izaskun

Spontaneous cerebrospinal fluid (CSF) leaks to the middle ear due to tegmen tympani defects can result in hearing loss or hypoacusis and predispose to meningitis as well as other neurological complications. Surgical repair of the defect can be performed through a middle cranial fossa (MCF) approach or a transmastoid approach. We conducted a retrospective study of the patients in our Department due to a spontaneous CSF leak to the middle ear treated using a MCF approach during a 6-year period (2009-2014). Thirteen patients with spontaneous CSF leak to the middle ear were treated with this approach. The primary and first symptom in all of them was conductive hearing loss. In all cases, the defect or defects were closed in a multilayer manner using muscle, temporalis fascia and cortical bone. Minimum follow-up in this series was 14 months, with successful closure in all but one patient (who required reintervention). We found no intra- or postoperative complications due to the craniotomy, and the audiometry improved and normalised in all cases except for the failed case. The MCF approach with a multilayer closure of the defect is an effective technique for repairing spontaneous CSF leaks to the middle ear and for restoring hearing in these patients. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

Post-operative diffusion weighted imaging as a predictor of posterior fossa syndrome permanence in paediatric medulloblastoma.

PubMed

Chua, Felicia H Z; Thien, Ady; Ng, Lee Ping; Seow, Wan Tew; Low, David C Y; Chang, Kenneth T E; Lian, Derrick W Q; Loh, Eva; Low, Sharon Y Y

2017-03-01

Posterior fossa syndrome (PFS) is a serious complication faced by neurosurgeons and their patients, especially in paediatric medulloblastoma patients. The uncertain aetiology of PFS, myriad of cited risk factors and therapeutic challenges make this phenomenon an elusive entity. The primary objective of this study was to identify associative factors related to the development of PFS in medulloblastoma patient post-tumour resection. This is a retrospective study based at a single institution. Patient data and all related information were collected from the hospital records, in accordance to a list of possible risk factors associated with PFS. These included pre-operative tumour volume, hydrocephalus, age, gender, extent of resection, metastasis, ventriculoperitoneal shunt insertion, post-operative meningitis and radiological changes in MRI. Additional variables included molecular and histological subtypes of each patient's medulloblastoma tumour. Statistical analysis was employed to determine evidence of each variable's significance in PFS permanence. A total of 19 patients with appropriately complete data was identified. Initial univariate analysis did not show any statistical significance. However, multivariate analysis for MRI-specific changes reported bilateral DWI restricted diffusion changes involving both right and left sides of the surgical cavity was of statistical significance for PFS permanence. The authors performed a clinical study that evaluated possible risk factors for permanent PFS in paediatric medulloblastoma patients. Analysis of collated results found that post-operative DWI restriction in bilateral regions within the surgical cavity demonstrated statistical significance as a predictor of PFS permanence-a novel finding in the current literature.

NAS (Numerical Aerodynamic Simulation Program) technical summaries, March 1989 - February 1990

NASA Technical Reports Server (NTRS)

1990-01-01

Given here are selected scientific results from the Numerical Aerodynamic Simulation (NAS) Program's third year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP supercomputer. Topics covered include flow field analysis of fighter wing configurations, large-scale ocean modeling, the Space Shuttle flow field, advanced computational fluid dynamics (CFD) codes for rotary-wing airloads and performance prediction, turbulence modeling of separated flows, airloads and acoustics of rotorcraft, vortex-induced nonlinearities on submarines, and standing oblique detonation waves.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

NASA Technical Reports Server (NTRS)

Fern, Lisa

2017-01-01

This presentation summarizes the simulation work conducted by the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project. It focuses on the contribution of that research to the development of RTCA Special Committee 228's (SC-228) Minimum Operational Performance Standards (MOPS) for UAS. The research objectives and primary findings from four different human-in-the-loop simulations are discussed, along with the specific requirements these studies led to in the final MOPS document.

[Inventive activity of the Department of Metabolism Regulation of the Palladin Institute of Biochemistry of NAS of Ukraine].

PubMed

Danilova, V M; Vynogradova, R P; Chernysh, I G; Petrenko, T M

2016-01-01

The article is devoted to the inventive activity of the Department of Metabolism Regulation of the Palladin Institute of Biochemistry of NAS of Ukraine in the context of the history of its inception, development and the research activities of its founder, academician of NAS of Ukraine M. F. Guly as well as his students and followers. It briefly tells about practical achievements of M. F. Guly which were as significant, immense and diverse as his scientific accomplishments. The paper analyses in detail the practical results of scientific research of his students and followers aimed to solve practical problems of medicine, food-processing, agriculture, and which are essentially a continuation of the ideas and projects of M. F. Guly.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project FY16 Annual Review

NASA Technical Reports Server (NTRS)

Grindle, Laurie; Hackenberg, Davis

2016-01-01

This presentation gives insight into the research activities and efforts being executed in order to integrate unmanned aircraft systems into the national airspace system. This briefing is to inform others of the UAS-NAS FY16 progress and future directions.

Amorphous MoS3 as the sulfur-equivalent cathode material for room-temperature Li-S and Na-S batteries.

PubMed

Ye, Hualin; Ma, Lu; Zhou, Yu; Wang, Lu; Han, Na; Zhao, Feipeng; Deng, Jun; Wu, Tianpin; Li, Yanguang; Lu, Jun

2017-12-12

Many problems associated with Li-S and Na-S batteries essentially root in the generation of their soluble polysulfide intermediates. While conventional wisdom mainly focuses on trapping polysulfides at the cathode using various functional materials, few strategies are available at present to fully resolve or circumvent this long-standing issue. In this study, we propose the concept of sulfur-equivalent cathode materials, and demonstrate the great potential of amorphous MoS 3 as such a material for room-temperature Li-S and Na-S batteries. In Li-S batteries, MoS 3 exhibits sulfur-like behavior with large reversible specific capacity, excellent cycle life, and the possibility to achieve high areal capacity. Most remarkably, it is also fully cyclable in the carbonate electrolyte under a relatively high temperature of 55 °C. MoS 3 can also be used as the cathode material of even more challenging Na-S batteries to enable decent capacity and good cycle life. Operando X-ray absorption spectroscopy (XAS) experiments are carried out to track the structural evolution of MoS 3 It largely preserves its chain-like structure during repetitive battery cycling without generating any free polysulfide intermediates.

Identification of nitrogen- and host-related deep-level traps in n-type GaNAs and their evolution upon annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelczuk, Ł., E-mail: lukasz.gelczuk@pwr.edu.pl; Kudrawiec, R., E-mail: robert.kudrawiec@pwr.edu.pl; Henini, M.

2014-07-07

Deep level traps in as-grown and annealed n-GaNAs layers (doped with Si) of various nitrogen concentrations (N=0.2%, 0.4%, 0.8%, and 1.2%) were investigated by deep level transient spectroscopy. In addition, optical properties of GaNAs layers were studied by photoluminescence and contactless electroreflectance. The identification of N- and host-related traps has been performed on the basis of band gap diagram [Kudrawiec, Appl. Phys. Lett. 101, 082109 (2012)], which assumes that the activation energy of electron traps of the same microscopic nature decreases with the rise of nitrogen concentration in accordance with the N-related shift of the conduction band towards trap levels.more » The application of this diagram has allowed to investigate the evolution of donor traps in GaNAs upon annealing. In general, it was observed that the concentration of N- and host-related traps decreases after annealing and PL improves very significantly. However, it was also observed that some traps are generated due to annealing. It explains why the annealing conditions have to be carefully optimized for this material system.« less

Effects of growth rate on structural property and adatom migration behaviors for growth of GaInNAs/GaAs (001) by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Li, Jingling; Gao, Peng; Zhang, Shuguang; Wen, Lei; Gao, Fangliang; Li, Guoqiang

2018-03-01

We have investigated the structural properties and the growth mode of GaInNAs films prepared at different growth rates (Rg) by molecular beam epitaxy. The crystalline structure is studied by high resolution X-ray diffraction, and the evolution of GaInNAs film surface morphologies is studied by atomic force microscopy. It is found that both the crystallinity and the surface roughness are improved by increasing Rg, and the change in the growth mode is attributed to the adatom migration behaviors particularly for In atoms, which is verified by elemental analysis. In addition, we have presented some theoretical calculation results related to the N adsorption energy to show the unique N migration behavior, which is instructive to interpret the growth mechanism of GaInNAs films.

The ischiorectal fossa: an alternative route for the administration of prostaglandin in cattle

PubMed Central

Colazo, Marcos G.; MartÍnez, Marcelo F.; Kastelic, John P.; Mapletoft, Reuben J.; Carruthers, Terry D.

2002-01-01

Three experiments were conducted to investigate the ischiorectal fossa (IRF) as a route for the administration of prostaglandin F2α (dinoprost) in cattle. In Experiment 1, 21 nonlactating Holstein cows were given 100 μg of gonadotropin releasing hormone (GnRH), intramuscularly (IM), and, 7 d later, 25 mg of dinoprost into the IRF. Sixteen cows had serum progesterone concentrations ≥ 1.0 ng/mL at the time of dinoprost treatment, and all of these had rapid and complete luteolysis; the other 5 cows were not considered to have a functional corpus luteum (CL) at the time of treatment. There were minimal adverse behavioral reactions to the IRF injections and no visible or palpable tissue reactions at the injection site. In Experiment 2, 74 Holstein heifers were given 25 mg of dinoprost by IRF injection. Luteolysis occurred in 84.3% of the heifers with a functional CL (as determined by the serum progesterone concentration at the time of treatment). Of the heifers bred by either natural service or artificial insemination, 61.8% became pregnant. In Experiment 3, 48 beef heifers received dinoprost 7 d after ovulation, as follows: 25 mg, IM (n = 9); 25 mg, IRF (n = 10); 10 mg, IRF (n = 10); 10 mg, subcutaneously (SC) (n = 10); or 10 mg, intravulvosubmucosally (IVSM) (n = 9). Fewer heifers (P < 0.05) were found to be in estrus or ovulating in the 10 mg IVSM group (0% and 11%, respectively) than in the 25 mg IM group (100% and 100%), the 25 mg IRF group (90% and 100%, respectively), or the 10 mg IRF group (80% and 80%). The rates of estrus (50%) and ovulation (50%) were intermediate in the 10 mg SC group. In summary, 25 mg of dinoprost injected into the IRF caused minimal behavioral or tissue response and induced luteolysis and fertile estrus. In addition, 10 mg of dinoprost injected into the IRF was as efficacious as 25 mg given either IM or into the IRF in inducing estrus and ovulation. PMID:12125185

Middle Fossa Approach for Vestibular Schwannoma: Good Hearing and Facial Nerve Outcomes with Low Morbidity.

PubMed

Raheja, Amol; Bowers, Christian A; MacDonald, Joel D; Shelton, Clough; Gurgel, Richard K; Brimley, Cameron; Couldwell, William T

2016-08-01

The middle fossa approach (MFA) is not used as frequently as the traditional translabyrinthine and retrosigmoid approaches for accessing vestibular schwannomas (VSs). Here, MFA was used to remove primarily intracanalicular tumors in patients in whom hearing preservation is a goal of surgery. A retrospective chart review was performed to identify consecutive adult patients who underwent MFA for VS. Demographic profile, perioperative complications, pre- and postoperative hearing, and facial nerve outcomes were analyzed with linear regression analysis to identify factors predicting hearing outcome. Among 78 identified patients (mean age, 49 years; 53% female; mean tumor size, 7.5 mm), 78% had functional hearing preoperatively (American Academy of Otolaryngology-Head and Neck Surgery class A/B). Follow-up audiologic data were available for 60 patients overall (mean follow-up, 15.1 months). The hearing preservation rate was 75.5% (37/49) at last known follow-up for patients with functional hearing preoperatively. Other than preoperative hearing status (P < 0.001), none of the factors assessed, including demographic profile, size of tumor, and fundal fluid cap, predicted hearing preservation (P > 0.05). Good functional preservation of the facial nerve (House-Brackmann class I/II) was achieved in 90% of patients. The only operative complications were 3 wound infections (3.8%). Preliminary results from this single-center retrospective study of patients undergoing MFA for resection of VS showed that good hearing preservation and facial nerve outcomes could be achieved with few complications. These results suggest that resection via the MFA is a rational alternative to watchful waiting or stereotactic radiosurgery. Copyright © 2016 Elsevier Inc. All rights reserved.

[Intracranial granulocytic sarcoma extending from the posterior fossa to the carotid space via the jugular foramen: a case report].

PubMed

Baba, Shiro; Matsuo, Takayuki; Ishizaka, Shunsuke; Morikawa, Minoru; Suyama, Kazuhiko; Nagata, Izumi

2010-01-01

Granulocytic sarcoma consists of neoplastic granulocytic precursors and myeloblasts. It is a focal lesion seen in 2-10.9% of acute myelogenous leukaemia (AML) patients. It usually develops either concurrently with the AML or after a remission. On rare occasions, it may be an initial manifestation of AML. Most common involvement sites are bone, periostium, soft tissue, lymph nodes and skin. Intracranial granulocytic sarcoma rarely occurs in meningeal or parenchymal form. We present an extremely rare case of intracranial granulocytic sarcoma extending from the posterior fossa to the carotid space via the jugular foramen in a 69 year old female. This form of involvement has not been previously reported. On MRI, the lesion appears isointense compared with normal grey matter in T1 and T2 weighted images and shows homogeneous contrast enhancement. With these findings, it is difficult to differentiate the lesion from other extraaxial tumours such as meningioma, paraganglioma, schwannoma, carcinoma, metastatic tumor, malignant lymphoma. However, granulocytic sarcoma, densely increased tumour cells restrict diffusion and reduce the extracellular volume fraction, tends to be markedly hyperintense on diffusion-weighted MR images and exhibits a marked decrease in ADC values. Therefore, DWI may be helpful in differentiating granulocytic sarcoma from other intracranial lesions.

A Framework for Safe Integration of Small UAS Into the NAS

NASA Technical Reports Server (NTRS)

Logan, Michael J.; Bland, Geoffrey; Murray, Jennifer

2011-01-01

This paper discusses a proposed framework for the safe integration of small unmanned aerial systems (sUAS) into the National Airspace System (NAS). The paper examines the potential uses of sUAS to build an understanding of the location and frequency of potential future flight operations based on the future applications of the sUAS systems. The paper then examines the types of systems that would be required to meet the application-level demand to determine classes of platforms and operations. Finally, a framework is proposed for both airworthiness and operations that attempts to balance safety with utility for these important systems.

A Comparison of Cerebellar Retraction Pressures in Posterior Fossa Surgery: Extended Retrosigmoid Versus Traditional Retrosigmoid Approach.

PubMed

Liebelt, Brandon D; Huang, Meng; Britz, Gavin W

2018-05-01

The retrosigmoid approach is broadly applicable to many posterior fossa procedures. However, cerebellar retraction is often necessary for lesions in the cerebellopontine angle, which can lead to complications. An extended retrosigmoid approach skeletonizes the sigmoid sinus and allows a wider corridor with less retraction. This study investigated the differences in retraction pressure between the retrosigmoid and extended retrosigmoid approach in a cadaveric model. Anatomic dissection of 2 cadaveric heads was performed for comparison of surgical approaches. Bilateral measurements were obtained on each head, providing 4 sets of data. Retrosigmoid craniotomy was first performed with recording of retraction pressure necessary for 1.5-cm exposure. The exposure was then expanded to an extended retrosigmoid approach, and retraction pressures were recorded. Mean retraction pressure in cadaver 1 for retrosigmoid and extended retrosigmoid approaches was 20.25 ± 5.9 mm Hg and 10.25 ± 3.8 mm Hg, respectively; in cadaver 2, values were 11.75 ± 3.1 mm Hg and 4.75 ± 1.8 mm Hg, respectively. This corresponded to a mean relative reduction in retraction pressure of 49.4% in cadaver 1 and 59.6% in cadaver 2 by using the extended retrosigmoid approach. Retraction pressures were also significantly less (P < 0.05) for the extended retrosigmoid group when comparing all surgical approaches (N = 4). The extended retrosigmoid approach gains better visualization with reduced brain retraction. In our study, cerebellar retraction pressures were greatly reduced when using the extended retrosigmoid approach in a cadaveric model. Copyright © 2018. Published by Elsevier Inc.

UAS Integration Into the NAS: An Examination of Baseline Compliance in the Current Airspace System

NASA Technical Reports Server (NTRS)

Fern, Lisa; Kenny, Caitlin A.; Shively, Robert J.; Johnson, Walter

2012-01-01

As a result of the FAA Modernization and Reform Act of 2012, Unmanned Aerial Systems (UAS) are expected to be integrated into the National Airspace System (NAS) by 2015. Several human factors challenges need to be addressed before UAS can safely and routinely fly in the NAS with manned aircraft. Perhaps the most significant challenge is for the UAS to be non-disruptive to the air traffic management system. Another human factors challenge is how to provide UAS pilots with intuitive traffic information in order to support situation awareness (SA) of their airspace environment as well as a see-and-avoid capability comparable to manned aircraft so that a UAS pilot could safely maneuver the aircraft to maintain separation and collision avoidance if necessary. A simulation experiment was conducted to examine baseline compliance of UAS operations in the current airspace system. Researchers also examined the effects of introducing a Cockpit Situation Display (CSD) into a UAS Ground Control Station (GCS) on UAS pilot performance, workload and situation awareness while flying in a positively controlled sector. Pilots were tasked with conducting a highway patrol police mission with a Medium Altitude Long Endurance (MALE) UAS in L.A. Center airspace with two mission objectives: 1) to reroute the UAS when issued new instructions from their commander, and 2) to communicate with Air Traffic Control (ATC) to negotiate flight plan changes and respond to vectoring and altitude change instructions. Objective aircraft separation data, workload ratings, SA data, and subjective ratings regarding UAS operations in the NAS were collected. Results indicate that UAS pilots were able to comply appropriately with ATC instructions. In addition, the introduction of the CSD improved pilot SA and reduced workload associated with UAS and ATC interactions.

Redshift and blueshift of GaNAs/GaAs multiple quantum wells induced by rapid thermal annealing

NASA Astrophysics Data System (ADS)

Sun, Yijun; Cheng, Zhiyuan; Zhou, Qiang; Sun, Ying; Sun, Jiabao; Liu, Yanhua; Wang, Meifang; Cao, Zhen; Ye, Zhi; Xu, Mingsheng; Ding, Yong; Chen, Peng; Heuken, Michael; Egawa, Takashi

2018-02-01

The effects of rapid thermal annealing (RTA) on the optical properties of GaNAs/GaAs multiple quantum wells (MQWs) grown by chemical beam epitaxy (CBE) are studied by photoluminescence (PL) at 77 K. The results show that the optical quality of the MQWs improves significantly after RTA. With increasing RTA temperature, PL peak energy of the MQWs redshifts below 1023 K, while it blueshifts above 1023 K. Two competitive processes which occur simultaneously during RTA result in redshift at low temperature and blueshift at high temperature. It is also found that PL peak energy shift can be explained neither by nitrogen diffusion out of quantum wells nor by nitrogen reorganization inside quantum wells. PL peak energy shift can be quantitatively explained by a modified recombination coupling model in which redshift nonradiative recombination and blueshift nonradiative recombination coexist. The results obtained have significant implication on the growth and RTA of GaNAs material for high performance optoelectronic device application.

[A Case of Ruptured Internal Carotid-Posterior Communicating Artery Aneurysm Associated with Acute Subdural Hematoma, Extending from the Interhemispheric Space to the Posterior Fossa].

PubMed

Otsuka, Hiroaki; Fukuda, Yuhtaka; Yoshimura, Shouta; Somagawa, Chika; Hiu, Takeshi; Ono, Tomonori; Ushijima, Ryujirou; Toda, Keisuke; Tsutsumi, Keisuke

2016-06-01

A 69-year-old woman was admitted to our hospital because of a sudden severe headache without a history of head trauma. CT and MRI revealed an acute subdural hematoma (ASDH) extending from the right interhemispheric space to the posterior fossa bilaterally, with a small amount of subarachnoid hemorrhage that was predominantly localized to the left side of the basal cistern. CT angiogram demonstrated a long protruding ruptured aneurysm at the junction of the right internal carotid and posterior communicating arteries (IC/PC AN) with a posteroinferior projection, associated with a small bleb located near the tentorial edge close to the ipsilateral posterior clinoid process, for which she received clipping surgery. Though rare, IC/PC AN could cause pure or nearly pure ASDH in the above-mentioned distribution. Therefore, in patients with such ASDH, especially without a history of head injury or precise information regarding the situation at the time of onset, urgent imaging evaluation and early intervention are essential to prevent devastating re-rupture events.

NAS Demand Predictions, Transportation Systems Analysis Model (TSAM) Compared with Other Forecasts

NASA Technical Reports Server (NTRS)

Viken, Jeff; Dollyhigh, Samuel; Smith, Jeremy; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

2006-01-01

The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These

Enhancement of photocurrent in epitaxial lift-off thin-film GaInNAsSb solar cells due to light-confinement structure

NASA Astrophysics Data System (ADS)

Miyashita, Naoya; Behaghel, Benoît; Guillemoles, Jean-François; Okada, Yoshitaka

2018-07-01

This work focuses on the characterization of GaInNAsSb solar cells whose substrates are removed via the epitaxial lift-off (ELO) technique. As a result of the substrate removal, increases in the photocurrent and the interference feature were clearly observed. This is clear evidence of the light-confinement effect, whereby some of the unabsorbed photons at the rear metal contact were reflected back towards the front side of the ELO thin-film cell. We successfully demonstrated that the ELO technique can be applied for the GaInNAsSb cell, and the light management should add flexibility in designing the cell structures.

Unmanned Aircraft Systems (UAS): Addressing the Regulatory Issues for National Airspace System (NAS) Integration

DTIC Science & Technology

2009-04-01

terms of IFR operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface...are serviced by a radar approach control, and that have a certain number of IFR operations or passenger enplanements. Although the configuration of...ft MSL Figure 3 depicts DoD UASs operating in their respective NAS classifications: Global Hawk Predator B Transponder See & Avoid DME IFR

Right Iliac Fossa Pain Treatment (RIFT) Study: protocol for an international, multicentre, prospective observational study

PubMed Central

2018-01-01

Introduction Patients presenting with right iliac fossa (RIF) pain are a common challenge for acute general surgical services. Given the range of potential pathologies, RIF pain creates diagnostic uncertainty and there is subsequent variation in investigation and management. Appendicitis is a diagnosis which must be considered in all patients with RIF pain; however, over a fifth of patients undergoing appendicectomy, in the UK, have been proven to have a histologically normal appendix (negative appendicectomy). The primary aim of this study is to determine the contemporary negative appendicectomy rate. The study’s secondary aims are to determine the rate of laparoscopy for appendicitis and to validate the Appendicitis Inflammatory Response (AIR) and Alvarado prediction scores. Methods and analysis This multicentre, international prospective observational study will include all patients referred to surgical specialists with either RIF pain or suspected appendicitis. Consecutive patients presenting within 2-week long data collection periods will be included. Centres will be invited to participate in up to four data collection periods between February and August 2017. Data will be captured using a secure online data management system. A centre survey will profile local policy and service delivery for management of RIF pain. Ethics and dissemination Research ethics are not required for this study in the UK, as determined using the National Research Ethics Service decision tool. This study will be registered as a clinical audit in participating UK centres. National leads in countries outside the UK will oversee appropriate registration and study approval, which may include completing full ethical review. The study will be disseminated by trainee-led research collaboratives and through social media. Peer-reviewed publications will be published under corporate authorship including ‘RIFT Study Group’ and ‘West Midlands Research Collaborative’. PMID:29331965

Operational Overview for Unmanned Aircraft Systems (UAS) Integration in the National Airspace (NAS) Project Flight Test Series 3

NASA Technical Reports Server (NTRS)

Valkov, Steffi

2017-01-01

This presentation is a high level overview of the flight testing that took place in 2015 for the UAS-NAS project. All topics in the presentation discussed at a high level and no technical details are provided.

[Arthrodesis of the shoulder. A new and soft-tissue-sparing technique with a deep locking plate in the supraspinatus fossa].

PubMed

Klonz, A; Habermeyer, P

2007-10-01

Arthrodesis of the glenohumeral joint is a difficult intervention that involves a relatively high probability of complications. A stable internal fixation and secure consolidation is required. The operation needs to achieve several conditions: thorough denudation of the cartilage and partial decortication of the subchondral bone; good congruence of the corresponding surfaces; compression of the gap by tension screws and lasting stability. For increased primary stability a neutralizing plate is generally used as well as a compression screw. Up to now, the plate has usually been applied starting from the scapular spine and extending across the acromial corner to the humeral shaft. A wide exposure is needed for this procedure; the plate is difficult to shape during the operation and often causes some discomfort because it protrudes at the acromial corner. We present an alternative position of the plate in the supraspinatus fossa, where we have sited a 4.5 mm LCP locking plate (Synthes). The implant is inserted under the acromion, does not cause any discomfort at the acromial corner, and is far easier to shape. When it is used in association with a transarticular compressive screw, the technique results in a very stable situation, which allows physiotherapy from the first day after surgery onward.

Quantitative analysis of attachment of the labrum to the glenoid fossa: a cadaveric study.

PubMed

Yoshida, Masahito; Goto, Hideyuki; Nozaki, Masahiro; Nishimori, Yasuhiro; Takenaga, Tetsuya; Murase, Atsunori; Nagaya, Yuko; Iguchi, Hirotaka; Kobayashi, Masaaki; Sugimoto, Katsumasa; Nishiyama, Takeshi; Otsuka, Takanobu

2015-09-01

This study investigated the direct and continuous attachment of the labrum to the glenoid fossa, including the fibrocartilaginous tissue, using image-analysis software and histology. Twenty-six cadaveric shoulders (11 male, 15 female; mean age 80.1 years; age range 36-103 years) were used. The glenoid of each specimen was divided into six pie-slice-shaped pieces from the center perpendicular to the articular surface by radial incisions at the 2, 4, 6, 8, 10, and 12 o'clock positions. The general distribution of the labrum, including the fibrocartilage, was assessed in hematoxylin and eosin-, Safranin O- and Azan-Mallory-stained sections. The continuous length of attachment of the labrum to the glenoid was measured using image-analysis software. The width of attachment to the articular surface of the glenoid was assessed in each position. The labrum attached to both the articular surface and the neck of the glenoid in all shoulders (100 %) in the 4 and 6 o'clock positions. The mean length of the entire attachment to the glenoid was 4.6 mm (range 3.2-6.1 mm). The width of attachment from the bony edge of the glenoid to the edge of the labrum on the articular surface ranged from 0 to 4.3 mm. The length of the entire attachment of the labrum was shortest in the 2 o'clock position (p = 0.229). Additionally, the length of the entire attachment of the labrum was longest in the 4 o'clock position. The width of attachment to the articular surface of the glenoid was greatest in the 4 o'clock position (p < 0.01). In the 4 and 6 o'clock positions, the labrum attached to both the articular surface and neck of the glenoid in all of the shoulders (100 %). The length of the entire attachment to the labrum, including the fibrocartilage, was shortest in the 2 o'clock position. The width of attachment to the articular surface of the glenoid was greatest in the 4 o'clock position (p < 0.01).

Middle infratemporal fossa less invasive approach for radical resection of parapharyngeal tumors: surgical microanatomy and clinical application.

PubMed

Nonaka, Yoichi; Fukushima, Takanori; Watanabe, Kentaro; Sakai, Jun; Friedman, Allan H; Zomorodi, Ali R

2016-01-01

Surgery of the infratemporal fossa (ITF) and parapharyngeal area presents a formidable challenge to the surgeon due to its anatomical complexity and limited access. Conventional surgical approaches to these regions were often too invasive and necessitate sacrifice of normal function and anatomy. To describe a less invasive transcranial extradural approach to ITF parapharyngeal lesions and to determine its advantages, 17 patients with ITF parapharyngeal neoplasms who underwent tumor resection via this approach were enrolled in the study. All lesions located in the ITF precarotid parapharyngeal space were resected through a small operative corridor between the trigeminal nerve third branch (V3) and the temporomandibular joint (TMJ). Surgical outcomes and postoperative complications were evaluated. Pathological diagnosis included schwannoma in eight cases, paraganglioma in two cases, gangliocytoma in two cases, carcinosarcoma in one case, giant cell tumor in one case, pleomorphic adenoma in one case, chondroblastoma in one case, and juvenile angiofibroma in one case. Gross total resection was achieved in 12 cases, near-total and subtotal resection were in 3 and 2 cases, respectively. The most common postoperative complication was dysphagia. Surgical exposure can be customized from minimal (drilling of retrotrigeminal area) to maximal (full skeletonization of V3, removal of all structures lying lateral to the petrous segment of internal carotid artery) according to tumor size and location. Since the space between the V3 and TMJ is the main corridor of this approach, the key maneuver is the anterior translocation of V3 to obtain an acceptable surgical field.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project. NASA Contributions to the SARP WC Definition

NASA Technical Reports Server (NTRS)

Randall, Debra K.; Consiglio, Maria Cristina; Santiago, Confesor

2014-01-01

To better inform sense and avoid research needs and to understand ongoing investigation of potential solutions that ultimately lead to the assisting the FAA with their Congressional mandate to fly UAS in the NAS.

Remotely Operated Aircraft (ROA) Impact on the National Airspace System (NAS) Work Package, 2005: Composite Report on FAA Flight Plan and Operational Evaluation Plan. Version 7.0

NASA Technical Reports Server (NTRS)

2005-01-01

The purpose of this document is to present the findings that resulted from a high-level analysis and evaluation of the following documents: (1) The OEP (Operational Evolution Plan) Version 7 -- a 10-year plan for operational improvements to increase capacity and efficiency in U.S. air travel and transport and other use of domestic airspace. The OEP is the FAA commitment to operational improvements. It is outcome driven, with clear lines of accountability within FAA organizations. The OEP concentrates on operational solutions and integrates safety, certification, procedures, staffing, equipment, avionics and research; (2) The Draft Flight Plan 2006 through 2010 -- a multi-year strategic effort, setting a course for the FAA through 2001, to provide the safest and most efficient air transportation system in the world; (3) The NAS System Architecture Version 5 -- a blueprint for modernizing the NAS and improving NAS services and capabilities through the year 2015; and (4) The NAS-SR-1000 System Requirements Specification (NASSRS) -- a compilation of requirements which describe the operational capabilities for the NAS. The analysis is particularly focused on examining the documents for relevance to existing and/or planned future UAV operations. The evaluation specifically focuses on potential factors that could materially affect the development of a commercial ROA industry, such as: (1) Design limitations of the CNS/ATM system, (2) Human limitations, The information presented was taken from program specifications or program office lead personnel.

Molecular heterogeneity and CXorf67 alterations in posterior fossa group A (PFA) ependymomas.

PubMed

Pajtler, Kristian W; Wen, Ji; Sill, Martin; Lin, Tong; Orisme, Wilda; Tang, Bo; Hübner, Jens-Martin; Ramaswamy, Vijay; Jia, Sujuan; Dalton, James D; Haupfear, Kelly; Rogers, Hazel A; Punchihewa, Chandanamali; Lee, Ryan; Easton, John; Wu, Gang; Ritzmann, Timothy A; Chapman, Rebecca; Chavez, Lukas; Boop, Fredrick A; Klimo, Paul; Sabin, Noah D; Ogg, Robert; Mack, Stephen C; Freibaum, Brian D; Kim, Hong Joo; Witt, Hendrik; Jones, David T W; Vo, Baohan; Gajjar, Amar; Pounds, Stan; Onar-Thomas, Arzu; Roussel, Martine F; Zhang, Jinghui; Taylor, J Paul; Merchant, Thomas E; Grundy, Richard; Tatevossian, Ruth G; Taylor, Michael D; Pfister, Stefan M; Korshunov, Andrey; Kool, Marcel; Ellison, David W

2018-06-16

Of nine ependymoma molecular groups detected by DNA methylation profiling, the posterior fossa type A (PFA) is most prevalent. We used DNA methylation profiling to look for further molecular heterogeneity among 675 PFA ependymomas. Two major subgroups, PFA-1 and PFA-2, and nine minor subtypes were discovered. Transcriptome profiling suggested a distinct histogenesis for PFA-1 and PFA-2, but their clinical parameters were similar. In contrast, PFA subtypes differed with respect to age at diagnosis, gender ratio, outcome, and frequencies of genetic alterations. One subtype, PFA-1c, was enriched for 1q gain and had a relatively poor outcome, while patients with PFA-2c ependymomas showed an overall survival at 5 years of > 90%. Unlike other ependymomas, PFA-2c tumors express high levels of OTX2, a potential biomarker for this ependymoma subtype with a good prognosis. We also discovered recurrent mutations among PFA ependymomas. H3 K27M mutations were present in 4.2%, occurring only in PFA-1 tumors, and missense mutations in an uncharacterized gene, CXorf67, were found in 9.4% of PFA ependymomas, but not in other groups. We detected high levels of wildtype or mutant CXorf67 expression in all PFA subtypes except PFA-1f, which is enriched for H3 K27M mutations. PFA ependymomas are characterized by lack of H3 K27 trimethylation (H3 K27-me3), and we tested the hypothesis that CXorf67 binds to PRC2 and can modulate levels of H3 K27-me3. Immunoprecipitation/mass spectrometry detected EZH2, SUZ12, and EED, core components of the PRC2 complex, bound to CXorf67 in the Daoy cell line, which shows high levels of CXorf67 and no expression of H3 K27-me3. Enforced reduction of CXorf67 in Daoy cells restored H3 K27-me3 levels, while enforced expression of CXorf67 in HEK293T and neural stem cells reduced H3 K27-me3 levels. Our data suggest that heterogeneity among PFA ependymomas could have clinicopathologic utility and that CXorf67 may have a functional role in these tumors.

EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments (External Review Draft)

EPA Science Inventory