Journal articles: 'Deep-seated Structures'

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Barla, Giovanni. "Numerical modeling of deep-seated landslides interacting with man-made structures." Journal of Rock Mechanics and Geotechnical Engineering 10, no. 6 (December 2018): 1020–36. http://dx.doi.org/10.1016/j.jrmge.2018.08.006.

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Poddar. "Grounded-source TEM modelling of some deep-seated 3D resistivity structures." Geophysical Prospecting 47, no. 6 (November 1999): 945–58. http://dx.doi.org/10.1046/j.1365-2478.1999.00157.x.

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Crawford, C. B., N. R. McCammon, and R. C. Butler. "Deep-seated consolidation settlements in the Fraser River delta." Canadian Geotechnical Journal 28, no. 2 (April 1, 1991): 298–303. http://dx.doi.org/10.1139/t91-035.

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This paper describes the settlements of three heavy silo structures at two cement plants located along the south arm of the Fraser River delta. In this area, it has not been possible to obtain sufficiently undisturbed samples for reliable consolidation tests, and it has been necessary therefore to employ in situ tests and site improvement techniques such as preloading and vibrocompaction for the design of foundations. In some cases, piles were used to redistribute heavy loads. Observations during the past 35 years have shown that most of the consolidation settlement has occurred in a deep layer of marine sediments and that it is largely completed within 10 years of the loading. Key words: case record, consolidation, foundation performance, in situ tests, preloading, settlements, site improvement.

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Abdelrahman, El‐Sayed M., Hesham M. El‐Araby, Tarek M. El‐Araby, and Khalid S. Essa. "A new approach to depth determination from magnetic anomalies." GEOPHYSICS 67, no. 5 (September 2002): 1524–31. http://dx.doi.org/10.1190/1.1512748.

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We have developed a semiautomatic method to determine the depth to shallow and deep‐seated structures from a magnetic anomaly profile. It involves using a relationship between the depths to two coaxial sources obtained by combining observations at symmetric points with respect to the coordinate of the sources center. For five established, fixed data points, the depth to the shallow structure is determined for each preassigned depth of the deep‐seated structure. The computed depths to the shallow structure are plotted against the computed depths to the deep‐seated structure, yielding a continuous, monotonically increasing depth curve. The spacing between the observations is then modified, producing several curves. The accepted estimates for the depths to both structures are read at the common intersection of these curves. The effective intensity and the angle of magnetization of both structures are also estimated. The proposed method was tested both on noisy synthetic and real magnetic data. In the case of synthetic data, the depth curves method determined the correct depths of both coaxial and laterally offset sources. In the case of practical data (vertical component anomaly over a chromite body in the Guleman concession, Turkey), the method suggested the shape of the buried shallow structure resembles a horizontal cylinder model buried at a depth of 31 m and the shape of the buried deep seated structure resembles a dike model buried at a depth of 62 m. The estimated shape and depth of the shallow structure are in very good agreement with the results obtained from drilling and surface geology. The area appears to still hold promise for chromite exploration from the deeper structure.

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GOODIN, ROBERT E. "Structures of Mutual Obligation." Journal of Social Policy 31, no. 4 (October 2002): 579–96. http://dx.doi.org/10.1017/s004727940200675x.

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‘Mutual obligation’ is a deft political slogan. Morally, it evokes deep-seated intuitions about ‘fair reciprocity’ and the ‘duty of fair play’. It seems an easy slide from those intuitions to ‘mutual obligation’ policies demanding work-for-the-dole. That slide is illegitimate, however. There are many different ways to structure mutual obligation. Workfare policies, such as the Howard government's ‘Mutual Obligation Initiative’ in Australia, pick out only one among many alternative regimes that would answer equally well to our root intuitions about ‘fair reciprocity’. Other ways of structuring mutual obligations within social welfare policy are both more standard and more desirable.

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Genshaft, Yu S., and I. P. Ilupin. "On genetic classification of chromian spinels in deep-seated rocks from continental structures." Russian Journal of Earth Sciences 4, no. 2 (March 26, 2002): 153–62. http://dx.doi.org/10.2205/2002es000086.

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Suvorov, A. I. "RELATIONSHIPS BETWEEN NEAR-SURFACE AND DEEP-SEATED STRUCTURES IN THE URALIAN-MONGOLIAN FOLDBELT." International Geology Review 32, no. 7 (July 1990): 645–56. http://dx.doi.org/10.1080/00206819009465806.

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Shashivadhanan, Sundaravadhanan. "Transparent Tubular Retractor in Cranial Surgery: A Retrospective Analysis." Indian Journal of Neurosurgery 09, no. 01 (December 9, 2019): 13–16. http://dx.doi.org/10.1055/s-0039-1698844.

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Abstract Introduction The fourth Industrial Revolution has touched nearly all aspects of neurosurgery and the newer tubular retractor systems are a testimony to this fact. They aid in providing better visualization with minimal damage to those neural structures, which happen to be innocent bystanders overlying the path of deep-seated lesions. In addition to providing better patient outcomes they are surgeon friendly with their ergonomic design and improved stability, thereby causing minimal fatigue, and aid in procedures requiring precision and perseverance. A retrospective study conducted at a single institute analyzed the efficacy of transparent tubular retractors during cranial surgery for deep-seated lesions. Materials and Methods This retrospective study was conducted between April 2015 and July 2018 in a single institute wherein 22 patents with various deep-seated intracranial lesions were operated using the transparent tubular retractor, View Site Brain Access System (VBAS, Vycor Medical Inc.). Observation Of the 22 cases, 45% were of spontaneous intracerebral hemorrhage; 27% were high-grade gliomas; and the rest were colloid cyst, cystic tumors, and metastatic tumors in equal proportion. Total tumor excision was achieved in 27%, while 90% excision was achieved in 45% cases. The overall complication rate was 13%. Conclusion The transparent tubular retractors contribute to minimal invasiveness by causing uniform distribution of retraction pressure and minimal disruption of fiber tracts. Their use has a definite role in improving surgical outcomes for deep-seated intracranial lesions.

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Chigira, Masahiro, Ching-Ying Tsou, Yuki Matsushi, Narumi Hiraishi, and Makoto Matsuzawa. "Topographic precursors and geological structures of deep-seated catastrophic landslides caused by Typhoon Talas." Geomorphology 201 (November 2013): 479–93. http://dx.doi.org/10.1016/j.geomorph.2013.07.020.

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Iyer, Rajiv, and Kaisorn Chaichana. "Minimally Invasive Resection of Deep-seated High-grade Gliomas Using Tubular Retractors and Exoscopic Visualization." Journal of Neurological Surgery Part A: Central European Neurosurgery 79, no. 04 (April 23, 2018): 330–36. http://dx.doi.org/10.1055/s-0038-1641738.

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Background and Study Aims/Objective Deep-seated high-grade gliomas (HGGs) represent a unique surgical challenge because they reside deep to critical cortical and subcortical structures and infiltrate functional areas of the brain. Therefore, accessing and resecting these tumors can often be challenging and associated with significant morbidity. We describe the use of minimally invasive approaches to access deep-seated HGGs to achieve extensive resections while minimizing surgical morbidity. Materials and Methods All patients who underwent resection of a deep-seated intraparenchymal HGG with the use of a tubular retractor with exoscopic visualization from January 2016 to May 2017 were identified prospectively at a single institution. Variables evaluated included tumor location, pre- and postoperative neurologic function, extent of resection, and length of hospital stay. Results Overall, 14 patients underwent resection of an HGG (11 glioblastomas, 3 anaplastic astrocytomas) with a tubular retractor under exoscopic visualization. Seven tumors (50%) involved the thalamus, three (21%) the motor corticospinal tract, two (14%) the inferior frontal occipital fasciculus, one (7%) each the basal ganglia and optic pathway. The median preoperative Karnofsky Performance Score (KPS) was 70 (interquartile range: 55–80), where the major presenting symptom was motor weakness in seven (50%). The average plus or minus the standard error of the mean percentage resection was 97.0 ± 1.2%. The median hospital stay was 4 days (range: 2–7). At 1 month postoperatively, median postoperative KPS (within 30 days) was 87 (range: 77–90), where eight (57%) were improved, five (36%) were stable, and one (7%) was worse postoperatively. Conclusions Deep-seated HGGs can be accessed, visualized, and resected using tubular retractors and exoscopic visualization with minimal morbidity.

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Iijima, Keiya, Masafumi Hirato, Takaaki Miyagishima, Keishi Horiguchi, Kenichi Sugawara, Junko Hirato, Hideaki Yokoo, and Yuhei Yoshimoto. "Microrecording and image-guided stereotactic biopsy of deep-seated brain tumors." Journal of Neurosurgery 123, no. 4 (October 2015): 978–88. http://dx.doi.org/10.3171/2014.10.jns14963.

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OBJECT Image-guided stereotactic brain tumor biopsy cannot easily obtain samples of small deep-seated tumor or selectively sample the most viable region of malignant tumor. Image-guided stereotactic biopsy in combination with depth microrecording was evaluated to solve such problems. METHODS Operative records, MRI findings, and pathological specimens were evaluated in 12 patients with small deep-seated brain tumor, in which image-guided stereotactic biopsy was performed with the aid of depth microrecording. The tumors were located in the caudate nucleus (1 patient), thalamus (7 patients), midbrain (2 patients), and cortex (2 patients). Surgery was performed with a frameless stereotactic system in 3 patients and with a frame-based stereotactic system in 9 patients. Microrecording was performed to study the electrical activities along the trajectory in the deep brain structures and the tumor. The correlations were studied between the electrophysiological, MRI, and pathological findings. Thirty-two patients with surface or large brain tumor were also studied, in whom image-guided stereotactic biopsy without microrecording was performed. RESULTS The diagnostic yield in the group with microrecording was 100% (low-grade glioma 4, high-grade glioma 4, diffuse large B-cell lymphoma 3, and germinoma 1), which was comparable to 93.8% in the group without microrecording. The postoperative complication rate was as low as that of the conventional image-guided method without using microelectrode recording, and the mortality rate was 0%, although the target lesions were small and deep-seated in all cases. Depth microrecording revealed disappearance of neural activity in the tumor regardless of the tumor type. Neural activity began to decrease from 6.3 ± 4.5 mm (mean ± SD) above the point of complete disappearance along the trajectory. Burst discharges were observed in 6 of the 12 cases, from 3 ± 1.4 mm above the point of decrease of neural activity. Injury discharges were often found at 0.5–1 mm along the trajectory between the area of decreased and disappeared neural activity. Close correlations between electrophysiological, MRI, and histological findings could be found in some cases. CONCLUSIONS Image-guided stereotactic biopsy performed using depth microrecording was safe, it provided accurate positional information in real time, and it could distinguish the tumor from brain structures during surgery. Moreover, this technique has potential for studying the epileptogenicity of the brain tumor.

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Saito, Kuniaki, Keiichi Kobayashi, Daisuke Shimada, Shohei Iijima, Yoshiaki Shiokawa, and Motoo Nagane. "STMO-14 SURGICAL MANAGEMENT OF DEEP-SEATED GLIOMA AROUND THALAMUS." Neuro-Oncology Advances 1, Supplement_2 (December 2019): ii20. http://dx.doi.org/10.1093/noajnl/vdz039.090.

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Abstract BACKGROUND Higher extent of resection contributes to better prognosis of the patients with glioma. However, resection of deep-seated glioma represents a surgical challenge not only because of the depth but because of adjacent eloquent structures such as pyramidal tract, deep venous system, and brainstem. METHODS We performed a retrospective review of patients with deep-seated glioma around thalamus who underwent surgery between March 2014 and February 2019. The tumors were removed with use of neuronavigation, DTI tractography, electrophysiological monitoring and photo dynamics diagnosis using aminolevulinic acid via interhemispheric or transcortical approach. Volumetric analysis of preoperative tumor volume as well as postoperative residual volumes was performed. RESULTS A total of 17 patients, ages ranged from 13–79 years (median; 51) were eligible. Twelve patients underwent radical resection and 5 underwent biopsy (2 with craniotomy, 2 with endoscopy, and 1 stereotactic biopsy). Pathological diagnosis consisted of glioblastoma (GBM) in 10, diffuse midline glioma (DMG) in 3, anaplastic astrocytoma in 3, and diffuse astrocytoma in 1. Extent of resection of the patients attempted radical resection was 96.7%±6.4%. Postoperatively, 12 patients developed hemianopsia, 2 had hemiparesis because of corticospinal tract injury, 2 sensory disturbance, and 3 cognitive dysfunction. At 1 month after surgery, Karnofsky performance status (KPS) worsened in 5 GBM patients and 1 DMG patient, while improved or stable in the rest 11 patients. CONCLUSION Resection of deep-seated glioma around thalamus accompanies a high risk of neurological deficits. Nevertheless, radical resection without KPS decline can be achieved by preserving the corticospinal tract, deep venous system, and brainstem and minimizing damages of surrounding brain.

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Gadgil, Nisha, Matthew Muir, Melissa A. Lopresti, and Sandi K. Lam. "An update on pediatric surgical epilepsy: Part II." Surgical Neurology International 10 (December 27, 2019): 258. http://dx.doi.org/10.25259/sni_418_2019.

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Background: Recent advances may allow surgical options for pediatric patients with refractory epilepsy not previously deemed surgical candidates. This review outlines major technological developments in the field of pediatric surgical epilepsy. Methods: The literature was comprehensively reviewed and summarized pertaining to stereotactic electroencephalography (sEEG), laser ablation, focused ultrasound (FUS), responsive neurostimulation (RNS), and deep brain stimulation (DBS) in pediatric epilepsy patients. Results: sEEG allows improved seizure localization in patients with widespread, bilateral, or deep-seated epileptic foci. Laser ablation may be used for destruction of deep-seated epileptic foci close to eloquent structures; FUS has a similar potential application. RNS is a palliative option for patients with eloquent, multiple, or broad epileptogenic foci. DBS is another palliative approach in children unsuitable for respective surgery. Conclusion: The landscape of pediatric epilepsy is changing due to improved diagnostic and treatment options for patients with refractory seizures. These interventions may improve seizure outcomes and decrease surgical morbidity, though further research is needed to define the appropriate role for each modality.

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Perneczky, Axel, and Georg Fries. "Use of a new aneurysm clip with an inverted-spring mechanism to facilitate visual control during clip application." Journal of Neurosurgery 82, no. 5 (May 1995): 898–99. http://dx.doi.org/10.3171/jns.1995.82.5.0898.

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✓ When operating on deep-seated cerebral aneurysms, the surgeon's visual control of clip application may be impaired by the clip holder unless adjacent structures are retracted. To improve visual control and reduce the necessity for retraction, the senior author (A.P.) developed a new concept: an aneurysm clip with an inverted-spring mechanism. The clip has two jaws that point away from the clip blades. The jaws of the clip holder articulate with the inner side of the clip jaws. By distending the jaws of the clip holder the blades of the clip are opened and vice versa. Thus the visual field increases while the clip application is proceeding. This instrumentation is useful, especially in cases of deep-seated aneurysms arising from the posterior circulation and in multiple aneurysms. In these latter cases even lesions located contralaterally could be reached with good visual control.

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Prinja, R. K. "Observations of deep-seated structure in the stellar winds of OB stars." Highlights of Astronomy 10 (1995): 344–48. http://dx.doi.org/10.1017/s1539299600011497.

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High-resolution, time-resolved spectroscopy in both optical and UV wavebands has shown that the outer layers of luminous OB stars vary on time scales of hours-days. Spectroscopic monitoring with the IUE satellite provides evidence that the stellar winds of luminous, hot stars are not smooth and steady, but are frequently disrupted by the presence of time-dependent structures. In addition, variability is often present in optical photospheric line profiles; these variations are likely due to the influence of photospheric velocity fields, especially those from one or more modes of nonradial pulsation (NRP). The process (or processes) responsible for the formation of time-dependent wind structure is (are) not known. Issues concerning potential connections between NRPs, variations at the base of the outflow, and the development of wind structure pose some of the greatest challenges to our understanding of mass-loss via radiatively driven stellar winds.

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Avellone, Giuseppe, Massimiliano R. Barchi, Raimondo Catalano, Maurizio Gasparo Morticelli, and Attilio Sulli. "Interference between shallow and deep-seated structures in the Sicilian fold and thrust belt, Italy." Journal of the Geological Society 167, no. 1 (January 2010): 109–26. http://dx.doi.org/10.1144/0016-76492008-163.

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Behr, Whitney M., and Roland Bürgmann. "What’s down there? The structures, materials and environment of deep-seated slow slip and tremor." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 379, no. 2193 (February 2021): 20200218. http://dx.doi.org/10.1098/rsta.2020.0218.

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Deep-seated slow slip and tremor (SST), including slow slip events, episodic tremor and slip, and low-frequency earthquakes, occur downdip of the seismogenic zone of numerous subduction megathrusts and plate boundary strike-slip faults. These events represent a fascinating and perplexing mode of fault failure that has greatly broadened our view of earthquake dynamics. In this contribution, we review constraints on SST deformation processes from both geophysical observations of active subduction zones and geological observations of exhumed field analogues. We first provide an overview of what has been learned about the environment, kinematics and dynamics of SST from geodetic and seismologic data. We then describe the materials, deformation mechanisms, and metamorphic and fluid pressure conditions that characterize exhumed rocks from SST source depths. Both the geophysical and geological records strongly suggest the importance of a fluid-rich and high fluid pressure habitat for the SST source region. Additionally, transient deformation features preserved in the rock record, involving combined frictional-viscous shear in regions of mixed lithology and near-lithostatic fluid pressures, may scale with the tremor component of SST. While several open questions remain, it is clear that improved constraints on the materials, environment, structure, and conditions of the plate interface from geophysical imaging and geologic observations will enhance model representations of the boundary conditions and geometry of the SST deformation process. This article is part of a discussion meeting issue ‘Understanding earthquakes using the geological record’.

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BURBERRY, C. M., and J. M. PALU. "The influence of the Great Falls Tectonic Zone on the thrust sheet geometry of the southern Sawtooth Range, Montana, USA." Geological Magazine 153, no. 5-6 (June 3, 2016): 845–65. http://dx.doi.org/10.1017/s0016756816000431.

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AbstractThe reactivation potential of pre-existing deep-seated structures influences deformation structures produced in subsequent compression. This contribution investigates thrust geometries produced in surface thrust sheets of the Sawtooth Range, Montana, USA, deforming over a previously faulted sedimentary section. Surface thrust fault patterns were picked using existing maps and remote sensing. Thrust location and regional transport direction was also verified in the field. These observations were used to design a series of analogue models, involving deformation of a brittle cover sequence over a lower section with varying numbers of vertical faults. A final model tested the effect of decoupling the upper cover and lower section with a ductile detachment, in a scenario closer to that of the Sawtooth Range. Results demonstrate that complexity in surface thrust sheets can be related to heterogeneity within the lower sedimentary section, even when there is a detachment between this section and the rest of the cover. This complexity is best observed in the map view, as the models do not show the deep-seated faults propagating into the cover. These results were then used to predict specific locations of discrete basement fault strands in the study area, associated with what is generally mapped as the Scapegoat-Bannatyne Trend. The deep-seated faults are more likely to be reactivated as strike-slip features in nature, given the small obliquity between the ENE-directed compression direction and the NE-oriented basement faults. More generally, these results can be used to govern evaluation of thrust belts deforming over faulted basement, and to predict the locations of specific fault strands in a region where this information is unknown.

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Vega, Rafael A., Jeffrey I. Traylor, Rajan Patel, Matthew Muir, Dheigo C. A. Bastos, and Sujit S. Prabhu. "Combined Surgical Resection and Laser Interstitial Thermal Therapy for Glioblastoma: Technical Note." Journal of Neurological Surgery Part A: Central European Neurosurgery 81, no. 04 (May 3, 2020): 348–54. http://dx.doi.org/10.1055/s-0040-1709163.

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Abstract Background Glioblastoma multiforme (GBM) is an aggressive intracranial malignancy that confers a poor prognosis despite maximum surgical resection and chemoradiotherapy. Survival decreases further with deep-seated lesions. Laser interstitial thermal therapy (LITT) is an emerging minimally invasive technique for tumor ablation shown to reduce tumor burden effectively, particularly in deep-seated locations less amenable to gross total resection. We describe our initial technical experience of using the combination of LITT followed by surgical resection in patients with GBMs that exhibit both an easily accessible and deep-seated component. Materials and Methods Patients with GBM who received concurrent LITT and surgical resection at our institution were identified. Patient demographic and clinical information was procured from the University of Texas MD Anderson Cancer Center electronic medical record along with preoperative, postoperative, and 1-month follow-up magnetic resonance imaging (MRI). Results Four patients (n = 2 male, n = 2 female) with IDH-wild type GBM who received combined LITT and surgical resection were identified and analyzed retrospectively. All patients received chemoradiotherapy before presentation. All but one patient (75%) received resection before presentation. Median age was 54 years (range: 44–56 years). Median length of hospital stay was 6.5 days (range: 2–47 days). Median extent of combined ablation/resection was 90.4%. One of the four patients experienced complications in the perioperative or immediate follow-up periods. Local recurrence was observed in one patient during the follow-up period. Conclusion Malignant gliomas in deep-seated locations or in close proximity to white matter structures are challenging to manage. LITT followed by surgical resection may provide an alternative for tumor debulking that minimizes potential morbidities and extent of residual tumor. Further studies comparing this approach with standard resection techniques are warranted.

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TAO, Mingxin. "Characteristics of mantle degassing and deep-seated geological structures in different typical fault zones of China." Science in China Series D 48, no. 7 (2005): 1074. http://dx.doi.org/10.1360/04yd0040.

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Zbořil, L., J. Bodnár, O. Orlický, and J. Šefara. "Geophysical investigation of deep-seated oil-bearing structures in the central part of the African continent." Journal of African Earth Sciences (1983) 5, no. 2 (1986): 155–62. http://dx.doi.org/10.1016/0899-5362(86)90005-9.

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Sandvik, Ulrika, Marcus Ohlsson, and Erik Edström. "Vascular complications in pediatric craniopharyngioma patients: a case-based update." Child's Nervous System 35, no. 12 (October 30, 2019): 2273–78. http://dx.doi.org/10.1007/s00381-019-04394-8.

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Abstract Purpose Craniopharyngiomas remain a challenging entity for neurosurgeons because of their deep-seated, midline location, and intimate relationship with critical neurovascular structures. With high long-term survival rates, patients with craniopharyngioma are likely to experience significant late morbidity related to both disease and therapy. Method and results In this paper, we present two cases of late vascular complications after multi-modal treatment of craniopharyngioma. Conclusion Available data suggests that pediatric patients with craniopharyngioma represent a particularly vulnerable group.

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Chauhan, Onkar S., F. Almeida, and Cesar Moraes. "Regional geomorphology of the continental slope of NW India: Delineation of the signatures of deep‐seated structures." Marine Geodesy 15, no. 4 (January 1992): 283–96. http://dx.doi.org/10.1080/01490419209388065.

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Eyles, Nicholas, Joseph Boyce, and Arsalan A. Mohajer. "The Bedrock Surface of the Western Lake Ontario Region: Evidence of Reactivated Basement Structures?" Géographie physique et Quaternaire 47, no. 3 (November 23, 2007): 269–83. http://dx.doi.org/10.7202/032957ar.

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ABSTRACT Lower Paleozoic bedrock strata, in south-central Ontario and the adjacent part of New York State are covered by a thick (100m+) blanket of Pleistocene glacial and interglacial sediments. The form of the buried bedrock surface has been reconstructed from 70,000 waterwell boreholes that extend through the entire Pleistocene cover using GIS data processing techniques. The sub-drift bedrock surface shows linear channels that connect the basins of lakes Huron, Ontario and Erie and which form part of an ancestral mid-continent Great Lake drainage system prior to modification and infilling during successive Pleistocene glaciations. This relict drainage system is cut across Lower Paleozoic carbonates and elastics up to 500 m thick, but the position of several channels is aligned above terrane boundaries, faults and other deep-seated and poorly understood geophysical anomalies in underlying mid-Proterozoic Grenville basement rocks. Other channels are controlled by a dominant northwest and northeast trending regional joint system. A close relationship among deeply seated geophysical lineaments, basement structures and topographic lineaments cut across thick Paleozoic cover strata suggests a history of Phanerozoic reactivation and upward propagation of fractures from the Precambrian basement. Several basement structures and lineaments are seismically active suggesting ongoing neotectonic activity across the 'stable' craton of south-central Ontario.

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Lemaire, Emilie, Anne-Sophie Mreyen, Anja Dufresne, and Hans-Balder Havenith. "Analysis of the Influence of Structural Geology on the Massive Seismic Slope Failure Potential Supported by Numerical Modelling." Geosciences 10, no. 8 (August 18, 2020): 323. http://dx.doi.org/10.3390/geosciences10080323.

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The stability of rock slopes is often guided significantly by the structural geology of the rocks composing the slope. In this work, we analysed the influences of structural characteristics, and of their seismic responses, on large and deep-seated rock slope failure development. The study was focused on the Tamins and Fernpass rockslides in the European Alps and on the Balta and Eagle’s Lake rockslides in the southeastern Carpathians. These case studies were compared with catastrophic rock slope failures with ascertained or very likely seismic origin in the Tien Shan Mountains. The main goals was to identify indicators for seismically-induced rock slope failures based on the source zone rock structures and failure scar geometry. We present examples of failures in anti-dip slopes and along-strike rock structures that were potentially (or partially) caused by seismic triggering, and we also considered a series of mixed structural types, which are more difficult to interpret conclusively. Our morpho-structural study was supported by distinct element numerical modelling that showed that seismic shaking typically induces deep-seated deformation in initially “stable” rock slopes. In addition, for failures partially triggered by dynamic shaking, these studies can help identify the contribution of the seismic factor to slope instability. The identification of the partial seismic origin on the basis of the dynamic response of rock structures can be particularly interesting for case histories in less seismically active mountain regions (in comparison with the Andes, Tien Shan, Pamirs), such as in the European Alps and the Carpathian Mountains.

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Stewart, Simon A. "Detachment-controlled triangle zones in extension and inversion tectonics." Interpretation 2, no. 4 (November 1, 2014): SM29—SM38. http://dx.doi.org/10.1190/int-2014-0026.1.

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“Triangle zone” geometry is well established in thrust tectonics, where the leading edge of a frontal thrust branches backward onto a hinterland-directed roof thrust, and the triangle zone thus formed defines the thrust system’s leading edge. Similar geometries occur in extension and inversion settings, where a triangle zone can form between a deep-seated master fault and a roof fault or backthrust located in a hanging-wall detachment. In basement-controlled extension, triangle zone development can occur when the shear strength of the master fault plane in the zone above a hanging-wall detachment cutoff exceeds that of a new or reactivated antithetic fault detaching on the hanging-wall dip slope. This structural style is characterized by pronounced hanging-wall synclines linked to detached extensional faults higher up the hanging-wall dip slopes. The same principles apply during early phases of inversion tectonics. The part of the master fault that is above the hanging-wall detachment cutoff may constitute a buttress that causes displacement to backthrust along any available detachment into accommodation structures such as emergent ramps. This structural style is characterized by compressional structures within the graben while there is minor or even no sign of inversion on the graben margin faults. These geometries could be accounted for by other processes, for example, localized deep-seated fault-controlled structures within graben, or salt redistribution. However, fieldwork and analog models demonstrate the admissibility of triangle zone kinematics across a range of tectonic settings in the presence of detachment layers that are thin relative to the overall stratigraphy — typically tens to hundreds of meters in thickness. These models can guide seismic interpretation of unusual fold structures in extensional and inverted graben. Seismic interpretation examples were evaluated from the North Sea and Saudi Arabia.

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Pickard, Susan. "Ageism, Existential and Ontological: Reviewing Approaches toward the Abject with the Help of Millett, Hodgman, Lessing, and Roth." University of Toronto Quarterly 90, no. 2 (June 2021): 111–26. http://dx.doi.org/10.3138/utq.90.2.04.

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In an important and provocative recent article, Paul Higgs and Chris Gilleard have linked ageism not only to structural and institutional practices but to deep-seated existential and ontological fears and horrors regarding deep old age, as crystallized in the social imaginary of the fourth age. This concept suggests the need to combat not just the more modifiable structures of ageism but also the murkier and therefore more obdurate cultural aspects, especially the association of deep old age with the abject. In this article, I suggest the writings of George Bataille may help reimagine the frailties, “uglinesses,” and filth associated with deep old age. Exploring literary memoir and fiction by a range of writers through the prism of Bataille’s work, I consider how this new approach to abjection can undermine ageism and also serve as a gateway to a more meaningful vision of both old age and the life course itself.

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Donzé, Frédéric-Victor, Laurent Truche, Parisa Shekari Namin, Nicolas Lefeuvre, and Elena F. Bazarkina. "Migration of Natural Hydrogen from Deep-Seated Sources in the São Francisco Basin, Brazil." Geosciences 10, no. 9 (September 2, 2020): 346. http://dx.doi.org/10.3390/geosciences10090346.

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Hydrogen gas is seeping from the sedimentary basin of São Franciso, Brazil. The seepages of H2 are accompanied by helium, whose isotopes reveal a strong crustal signature. Geophysical data indicates that this intra-cratonic basin is characterized by (i) a relatively high geothermal gradient, (ii) deep faults delineating a horst and graben structure and affecting the entire sedimentary sequence, (iii) archean to paleoproterozoïc basements enriched in radiogenic elements and displaying mafic and ultramafic units, and (iv) a possible karstic reservoir located 400 m below the surface. The high geothermal gradient could be due to a thin lithosphere enriched in radiogenic elements, which can also contribute to a massive radiolysis process of water at depth, releasing a significant amount of H2. Alternatively, ultramafic rocks that may have generated H2 during their serpentinization are also documented in the basement. The seismic profiles show that the faults seen at the surface are deeply rooted in the basement, and can drain deep fluids to shallow depths in a short time scale. The carbonate reservoirs within the Bambuí group which forms the main part of the sedimentary layers, are crossed by the fault system and represent good candidates for temporary H2 accumulation zones. The formation by chemical dissolution of sinkholes located at 400 m depth might explain the presence of sub-circular depressions seen at the surface. These sinkholes might control the migration of gas from temporary storage reservoirs in the upper layer of the Bambuí formation to the surface. The fluxes of H2 escaping out of these structures, which have been recently documented, are discussed in light of the newly developed H2 production model in the Precambrian continental crust.

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Lahan, M. M., R. T. Verave, and P. Y. Irarue. "Geochemical study on hot-spring water in West New Britain Province, Papua New Guinea." Geothermal Energy Science 3, no. 1 (October 13, 2015): 61–67. http://dx.doi.org/10.5194/gtes-3-61-2015.

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<p><strong>Abstract.</strong> West New Britain Province, which occupies the western part of New Britain Island in Papua New Guinea, is ideally located within an active tectonic region that influences volcanism creating an environment favourable for geothermal activity. Geothermal mapping of surface manifestations reveals high temperature geothermal prospects along the northern coastline of West New Britain Province that are further confirmed by geochemical analysis. The occurrence of geothermal features is confined to the Quaternary Kimbe Volcanics and alluvium in the lowland areas. The features in Talasea appear to be controlled by deep-seated northerly trending faults while structures in Hoskins also appear to be deep seated but have not been identified. The geothermal systems in West New Britain Province have not been drilled, but preliminary reconnaissance geothermal mapping and geochemical analysis reveals four high temperature geothermal prospects suitable for further investigation and development of geothermal energy. These are the Pangalu (Rabili) and Talasea Station geothermal prospects in Talasea and Kasiloli (Magouru) and Silanga (Bakama and Sakalu) geothermal prospects in Hoskins. The calculated reservoir temperatures for these fields are in the range of 245–310 °C. Recommendations are made for further follow-up exploratory investigations.</p>

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Rajesh, Garg, Wing-Yuk Ip, S. P. Chow, and Boris Kwok-Keung Fung. "TREATING DEEP-SEATEDMYCOBACTERIUM MARINUMINFECTION IN THE HAND: A REPORT OF THREE CASES." Hand Surgery 11, no. 01n02 (January 2006): 83–88. http://dx.doi.org/10.1142/s0218810406003140.

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We report three cases of an unusual aggressive type of Mycobacterium marinum infection of the hand which had been a nightmare both for us and the patient. These were the patients in which even after repeated thorough surgical debridement and appropriate (drug sensitive) medical treatment over a period had resulted in amputation or devastation of the soft tissues so extensively that almost only the neurovascular bundle, bone and the skin were the only structures left (cosmetic fingers — no function) at the last debridement after which the infection has not recurred. By presenting this article we want to stress on certain points pertaining to diagnosis, management, varied presentation and of course the dreadful complications of deep-seated M. marinum infection.

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Wołosiewicz, Bartosz. "The influence of the deep seated geological structures on the landscape morphology of the Dunajec River catchment area, Central Carpathians, Poland and Slovakia." Contemporary Trends in Geoscience 7, no. 1 (June 1, 2018): 21–47. http://dx.doi.org/10.2478/ctg-2018-0002.

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Abstract The area of the Dunajec river basin includes several geological units in the Central Carpathian region at the Polish-Slovakian borderland. The paper focuses on the geomorphometric parameters of the drainage system to recognize the influence of the deep seated geological structures on the morphology of the Dunajec river basin (Central Carpathians). The study were enriched with analysis of the geological maps and lineaments extracted from Digital Elevation Model. According to the obtained results, the massive NW-SE trending fault zones play a vital role in the geological architecture of the researched area. The development of the secondary fault structures has been determined by these dislocations and the manifestation of their activity can be observed as deformations of some of the other tectonic structures along the main fault zones, especially at the folds’ axes. Additionally, the geometric and morphometric features of the drainage system have also been influenced by the activity of these deep structures. The tectonic activity represented by the level of morphological rejuvenation, visible in the light of the morphometric parameters of the streams and the drainage basins, varies greatly between the tectonic units. This diversity is caused by both the lithological and structural features of these geological units.

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Hamisch, Christina A., Jana Minartz, Tobias Blau, Vanessa Hafkemeyer, Daniel Rueß, Alexandra Hellerbach, Stefan J. Grau, and Maximilian I. Ruge. "Frame-based stereotactic biopsy of deep-seated and midline structures in 511 procedures: feasibility, risk profile, and diagnostic yield." Acta Neurochirurgica 161, no. 10 (July 29, 2019): 2065–71. http://dx.doi.org/10.1007/s00701-019-04020-1.

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Bodily, Lance, Arlan H. Mintz, and Johnathan Engh. "Combined Awake Craniotomy with Endoscopic Port Surgery for Resection of a Deep-Seated Temporal Lobe Glioma: A Case Report." Case Reports in Medicine 2013 (2013): 1–3. http://dx.doi.org/10.1155/2013/401359.

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The authors describe the combination of awake craniotomy and minimally invasive endoscopic port surgery to resect a high-grade glioma located near eloquent structures of the temporal lobe. Combined minimally invasive techniques such as these may facilitate deep tumor resection within eloquent regions of the brain, allowing minimum white matter dissection. Technical aspects of this procedure, a case outcome involving this technique, and the direction of further investigations for the utility of these techniques are discussed.

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Campbell, S. D. G., M. F. Howells, M. Smith, and A. J. Reedman. "A Caradoc Failed-Rift within the Ordovician Marginal Basin of Wales." Geological Magazine 125, no. 3 (May 1988): 257–66. http://dx.doi.org/10.1017/s0016756800010190.

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AbstractThe dolerite and basalt intrusions within the Lower Palaeozoic sequence of northwest Wales are largely restricted to the outcrop of Ordovician strata. Their distribution and close association with known volcano-tectonic structures were controlled by a tectonic framework of deep-seated fractures. In central and northern Snowdonia, volcanism during Caradoc times was related to the evolution of a fracture-controlled trough. An increase in the extensional stress across the trough with time is reflected in the progressive increase in basaltic magma movement during the volcanic cycle. The trough represents an attempted rift in the lithospheric plate, which failed to create an ocean basin and was subsequently aborted.

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Onida, M., F. Galadini, and F. Forcella. "Application of paleoseismological techniques to the study of Late Pleistocene-Holocene deep-seated gravitational movements at the Mortirolo Pass (central Alps, Italy)." Netherlands Journal of Geosciences 80, no. 3-4 (December 2001): 209–27. http://dx.doi.org/10.1017/s0016774600023842.

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AbstractPaleoseismological techniques have been used to investigate gravitational deformations at the Mortirolo Pass (Valtellina region, central Alps), in order to improve the knowledge on the activation mechanisms and the evolution of deep-seated gravitational slope movements. The deformation has been responsible for mass sliding towards the Valtellina depression through the activation of several-hundred-metre-long shear planes. Minor shear planes dipping towards the mountain played the role of antithetic structures. Four trenches were excavated across scarps representing the surficial expression of shear planes affecting the bedrock and Late Pleistocene-Holocene deposits. The excavations enabled to investigate the stratigraphy of Quaternary deposits and the geometry and kinematics of the shear planes affecting them. Radiocarbon analyses on organic material contained in sediments and paleosols enabled to define a succession of displacement events which occurred during the Late Pleistocene-Holocene. Collected data indicate the persistence of the activity until recent times (last movement related to 1810-1540 cal. BP). A sudden movement has been detected along one of the main shear surfaces (dipping towards the valley) with a vertical displacement of several metres. In contrast, numerous displacements (with lower vertical offset) have been detected along the antithetic shear planes. Different hypotheses have been proposed in the past to define the origin of huge gravitational movements (glacial retreat, uplift of the Alpine chain, fault activity). However, the Late Pleistocene cycles of glacial loading and unloading on the mountain slopes seem to be the most probable factors causing deep-seated gravitational movements in the investigated region. A recent dramatic landslide in an area adjacent to the investigated one (Mt. Zandila-Valpola) testifies to the paroxistic evolution of the large scale gravitational deformations. The densely inhabited Valtellina region is affected by a large number of gravitational structures similar to those of the Mortirolo area. In consideration of the possible effects of the paroxistic activation of these structures, detailed studies on the chronology and kinematics of the deformations through the application of paleoseismological techniques should therefore be encouraged.

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Marčan, Marija, Denis Pavliha, Bor Kos, Tadeja Forjanič, and Damijan Miklavčič. "Web-based tool for visualization of electric field distribution in deep-seated body structures and planning of electroporation-based treatments." BioMedical Engineering OnLine 14, Suppl 3 (2015): S4. http://dx.doi.org/10.1186/1475-925x-14-s3-s4.

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Rybin, A. K., E. A. Bataleva, K. S. Nepeina, and V. E. Matyukov. "VOLUMETRIC AND SPATIAL SEGMENTATION OF THE TIEN SHAN LITHOSPHERE ACCORDING TO GEOPHYSICAL DATA." Geodynamics & Tectonophysics 12, no. 3 (September 17, 2021): 508–43. http://dx.doi.org/10.5800/gt-2021-12-3-0537.

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This article consolidates the results of studying the deep structure of the lithosphere of the Central Tien Shan, which aimed to identify the main tectonic elements in its geophysical models. We have compared the structural and geological data with the information on the deep structure obtained by geophysical methods and from the positions of earthquake hypocenters in the study area. According to geological concepts, the Tien Shan orogenic belt is characterized by longitudinal and transverse segmentation. The boundaries of the Northern, Middle, Southern Western and Eastern segments of the Tien Shan are deep-seated fault structures. In deep faults and channels of heat and mass transfer, endogenous processes are localized. High-velocity, geoelectrical and thermal models consider such faults and channels as contrasting objects that can be referred to as indicators of these processes.Our analysis of the locations of earthquake hypocenters from NNC, KNET, CAIIG, KRNET, SOME catalogues shows that seismic events are strongly confined to the fault zones and the boundaries of large blocks. A correlation between the anomalies of geophysical fields suggests the degree of inheritance of tectonic structures and the boundaries of the main tectonic segments of the Tien Shan. To compare the crustal and upper mantle heterogeneities reflected in different geophysical fields, we have analyzed seismic tomographic sections based on volumetric seismotomographic models geoelectric and velocity sections along profiles across the main tectonic elements of the study area. The sections are used to identify the zones with relatively low (i.e. reduced) seismic wave velocities and detect the deep-seated longitudinal segmentation of the folded belt. Objects showing anomalous seismic wave velocities are found in the seismotomographic sections at all the depths under consideration. The most contrasting differences in the velocities of P- and S-waves are typical of the depths of 0-5 km and 50-65 km, showing the most clearly observed Northern, Southern and Western segments of the Tien Shan. In general, the velocities of P- and S-waves at the Northern Tien Shan are higher than those at the Middle and Southern segments. We have analyzed the distribution of geoelectric heterogeneities identified from magnetotelluric sounding data in order to determine the boundaries of the main tectonic elements that are considered as the zones of increased electrical conductivity confined to the boundaries of the fault structures. The distribution of earthquake epicenters clearly reflects the segmentation of the Tien Shan into the Northern, Middle and Southern segments and shows the Western and Eastern Tien Shan relative to the Talas-Fergana fault. Ourstudies of the crust and the upper mantle of the Tien Shan have confirmed that the abovementioned tectonic segments have differences in their deep structures Based on a comprehensive analysis of the study results, we can qualitatively identify a relationship between the distribution of the velocity and geoelectric heterogeneities in the crust and upper mantle, seismicity and the stress-strain state of the crust.

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von Hartmann, H. "Deformation of the Carboniferous on the Oldenburg High and the Location of the Variscan Front in Northwest Germany." Netherlands Journal of Geosciences 82, no. 2 (July 2003): 169–76. http://dx.doi.org/10.1017/s0016774600020722.

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AbstractThe article tries to answer the question of the origin and structural development of the deformation of the pre-Permian units southwest of Bremen. An interpretetion of a 3D-seismic survey was made to resolve the structural style of the Upper Carboniferous with the aim to get some clues for the Variscan deformation of the Variscan foreland. The area is suitable for the evaluation because of the existence of a 3D-seismic survey. Moreover, the depth of the Zechstein at. 4500 m is not to deep for imaging deeper reflections and there is not a severe distortion of the reflection pattern by later tectonic developments. Because of the 3D insight into the complex and deep seated structures, other 2D-seismic investigations which image similar parts can be better understood and interpretation errors can be avoided. It is concluded that only 3D-seismic measurements can resolve the complex structural devolopment at this site.

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Kantelhardt, Sven R., Angelika Gutenberg, Axel Neulen, Naureen Keric, Mirjam Renovanz, and Alf Giese. "Video-Assisted Navigation for Adjustment of Image-Guidance Accuracy to Slight Brain Shift." Operative Neurosurgery 11, no. 4 (July 30, 2015): 504–11. http://dx.doi.org/10.1227/neu.0000000000000921.

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Abstract BACKGROUND Information supplied by an image-guidance system can be superimposed on the operating microscope oculars or on a screen, generating augmented reality. Recently, the outline of a patient's head and skull, injected in the oculars of a standard operating microscope, has been used to check the registration accuracy of image guidance. OBJECTIVE To propose the use of the brain surface relief and superficial vessels for real-time intraoperative visualization and image-guidance accuracy and for intraoperative adjustment for brain shift. METHODS A commercially available image-guidance system and a standard operating microscope were used. Segmentation of the brain surface and cortical blood vessel relief was performed manually on preoperative computed tomography and magnetic resonance images. The overlay of segmented digital and real operating-microscope images was used to monitor image-guidance accuracy. Adjustment for brain shift was performed by manually matching digital images on real structures. RESULTS Experimental manipulation on a phantom proved that the brain surface relief could be used to restore accuracy if the primary registration shifted. Afterward, the technique was used to assist during surgery of 5 consecutive patients with 7 deep-seated brain tumors. The brain surface relief could be successfully used to monitor registration accuracy after craniotomy and during the whole procedure. If a certain degree of brain shift occurred after craniotomy, the accuracy could be restored in all cases, and corticotomies were correctly centered in all cases. CONCLUSION The proposed method was easy to perform and augmented image-guidance accuracy when operating on small deep-seated lesions.

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Akbari, S. Hassan A., Peter T. Sylvester, Charles Kulwin, Mitesh V. Shah, Aravind Somasundaram, Ashwin A. Kamath, Thomas L. Beaumont, Keith M. Rich, and Michael R. Chicoine. "Initial Experience Using Intraoperative Magnetic Resonance Imaging During a Trans-Sulcal Tubular Retractor Approach for the Resection of Deep-Seated Brain Tumors: A Case Series." Operative Neurosurgery 16, no. 3 (May 30, 2018): 292–301. http://dx.doi.org/10.1093/ons/opy108.

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Abstract BACKGROUND Treatment of deep-seated subcortical intrinsic brain tumors remains challenging and may be improved with trans-sulcal tubular brain retraction techniques coupled with intraoperative magnetic resonance imaging (iMRI). OBJECTIVE To conduct a preliminary assessment of feasibility and efficacy of iMRI in tubular retractor-guided resections of intrinsic brain tumors. METHODS Assessment of this technique and impact upon outcomes were assessed in a preliminary series of brain tumor patients from 2 centers. RESULTS Ten patients underwent resection with a tubular retractor system and iMRI. Mean age was 53.2 ± 9.0 yr (range: 37-61 yr, 80% male). Lesions included 6 gliomas (3 glioblastomas, 1 recurrent anaplastic astrocytoma, and 2 low-grade gliomas) and 4 brain metastases (1 renal cell, 1 breast, 1 lung, and 1 melanoma). Mean maximal tumor diameter was 2.9 ± 0.95 cm (range 1.2-4.3 cm). The iMRI demonstrated subtotal resection (STR) in 6 of 10 cases (60%); additional resection was performed in 5 of 6 cases (83%), reducing STR rate to 2 of 10 cases (20%), with both having tumor encroaching on eloquent structures. Seven patients (70%) were stable or improved neurologically immediately postoperatively. Three patients (30%) had new postoperative neurological deficits, 2 of which were transient. Average hospital length of stay was 3.4 ± 2.0 d (range: 1-7 d). CONCLUSION Combining iMRI with tubular brain retraction techniques is feasible and may improve the extent of resection of deep-seated intrinsic brain tumors that are incompletely visualized with the smaller surgical exposure of tubular retractors.

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Dobretsov, N. L., M. M. Buslov, A. N. Vasilevskiy, S. M. Zhmodik, and A. V. Kotlyarov. "First Results and Prospects of a New Approach to the Study of Active Geologic Processes by Space and Ground Instrumental Measurements (by the Example of Kamchatka and the Central Asian Orogenic Belt)." Russian Geology and Geophysics 62, no. 1 (January 1, 2021): 44–67. http://dx.doi.org/10.2113/rgg20204227.

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Abstract ––The use of satellite-geological information permits generalization of studies of various active geologic processes in a new way. As reference examples, we consider geologic regions extensively covered by research with our contribution. The joint use of satellite images, maps of gravity anomalies, and seismic-tomography data for Kamchatka made it possible to construct 3D models of surficial and deep-seated (depths from 10–50 to 650 km) volcanic structures. For young volcanosedimentary structures of Kamchatka, it is possible to trace the interaction of various processes, from crystallization of magmas in magma chambers to ore and oil formation in calderas. Ancient tectonic structures and superposed Cenozoic deformations in the Tien Shan, Altai, and Baikal regions are clearly displayed in satellite images and on maps of gravity anomalies. The long-range impact of the Indo-Eurasian collision on the Tien Shan, Altai, and Baikal regions was expressed as shearing, which resulted in the most contrasting structures in the zones of junction of regional faults and along the framing of cratonal structures. The active structures of Gorny Altai contain numerous travertines, whose abundance is correlated with seismic activity. The mass formation of methane and gas hydrates in Lake Baikal might be related to mantle plume fluids.

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Sharma, Mayur, Ghaith Habboub, Mandana Behbahani, Danilo Silva, Gene H. Barnett, and Alireza M. Mohammadi. "Thermal injury to corticospinal tracts and postoperative motor deficits after laser interstitial thermal therapy." Neurosurgical Focus 41, no. 4 (October 2016): E6. http://dx.doi.org/10.3171/2016.7.focus16216.

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OBJECTIVE Laser interstitial thermal therapy (LITT) has been increasingly used to treat deep-seated tumors. Despite its being minimally invasive, there is a risk of LITT damaging adjacent critical structures, including corticospinal tracts (CSTs). In this study, the authors investigated the predictive value of overlap between the hyperthermic field and CSTs in determining postoperative motor deficit (PMDs). METHODS More than 140 patients underwent an LITT procedure in our institution between April 2011 and June 2015. Because of the tumor's proximity to critical structures, 80 of them underwent preoperative diffusion tensor imaging and were included in this study. Extent of the hyperthermic field was delineated by the software as thermal-damage-threshold (TDT) lines (yellow [43°C for 2 minutes], blue [43°C for 10 minutes], and white [43°C for 60 minutes]). The maximum volume and the surface area of overlaps between motor fibers and the TDT lines were calculated and compared with the PMDs. RESULTS High-grade glioma (n = 46) was the most common indication for LITT. Postoperative motor deficits (partial or complete) were seen in 14 patients (11 with permanent and 3 with temporary PMDs). The median overlap volumes between CSTs with yellow, blue, and white TDT lines in patients with any PMD (temporary or permanent) were 1.15, 0.68, and 0.41 cm3, respectively. The overlap volumes and surface areas revealed significant differences in those with PMDs and those with no deficits (p = 0.0019 and 0.003, 0.012 and 0.0012, and 0.001 and 0.005 for the yellow, blue, and white TDT lines, respectively). The receiver operating characteristic was used to select the optimal cutoff point of the overlapped volumes and areas. Cutoff points for overlap volumes and areas based on optimal sensitivity (92%–100%) and specificity (80%–90%) were 0.103, 0.068, and 0.046 cm3 and 0.15, 0.07, and 0.11 mm2 for the yellow, blue, and white TDT lines, respectively. CONCLUSIONS Even a minimal overlap between the TDT lines and CSTs can cause a PMD after LITT. Precise planning and avoidance of critical structures and important white matter fibers should be considered when treating deep-seated tumors.

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Duddleston, Pate J., Julian L. Gendreau, Kristen A. Little, Amber Andrews, and Willard D. Thompson. "Navigation-guided neuroendoscopic removal of an intracranial migratory pellet from the thalamus of a 4-year-old girl." Journal of Neurosurgery: Pediatrics 26, no. 4 (October 2020): 445–48. http://dx.doi.org/10.3171/2020.4.peds19606.

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Extraction of a bullet fragment seated in deep brain parenchyma utilizing a neuroendoscope has not been previously reported in the literature. The authors report the case of a 4-year-old patient who presented after a pellet gun injury with a projectile located 6 cm intracranially and lodged within the posterior thalamus and near the posterior limb of the internal capsule. Initial operative repair included repair of a CSF leak with duraplasty, minimal brain debridement, and elevation of a depressed skull fracture. Subsequent CT at 2 months postoperatively revealed migration of the deep intracranial pellet. This finding correlated with intermittent worsening neurological symptoms and signs. A rigid 3-mm neuroendoscope with CT stereotactic navigation was then used to remove the pellet fragment from the thalamus. The patient returned home with alleviation of clinical symptoms and an uneventful postoperative recovery. This case demonstrates that navigation-guided neuroendoscopy can be successfully used to remove projectile fragments from deep brain structures, especially when the migration is along the initial path of the bullet. This technique represents another low-risk curative option in the management of retained bullet fragments in gunshot wound injuries to the head.

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White, Shawna E., and John W. F. Waldron. "Inversion of Taconian extensional structures during Paleozoic orogenesis in western Newfoundland." Geological Society, London, Special Publications 470, no. 1 (June 6, 2018): 311–36. http://dx.doi.org/10.1144/sp470.17.

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AbstractWest Newfoundland was critical in developing the Wilson Cycle concept. Neoproterozoic rifting established a passive margin adjacent to the Iapetus Ocean. Ordovician (Taconian) arc–continent collision emplaced ophiolites and the thin-skinned Humber Arm Allochthon. Subsequent Devonian (Acadian) ocean closure produced basement-cutting thrust faults that control the present-day distribution of units. New mapping, and aeromagnetic and seismic interpretation, around Parsons Pond enabled the recognition of structures in poorly exposed areas.Following Cambrian to Middle Ordovician passive-margin deposition, Taconian deformation produced a flexural bulge unconformity. Subsequent extensional faults shed localized conglomerate into the foreland basin. The Humber Arm Allochthon contains a series of stacked and folded duplexes, typical of thrust belts. To the east, the Parsons Pond Thrust has transported shelf and foreland-basin units c. 8 km westwards above the allochthon. The Long Range Thrust shows major topographical expression but <1 km offset. Stratigraphic relationships indicate that most thrusts originated as normal faults, active during Neoproterozoic rifting, and subsequently during Taconian flexure. Devonian continental collision inverted the Parsons Pond and Long Range thrusts. Basement-cored fault-propagation folds in Newfoundland are structurally analogous to basement uplifts in other orogens, including the Laramide Orogen in western USA. Similar deep-seated inversion structures may extend through the northern Appalachians.

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Wendt, Alexander E. "The agent-structure problem in international relations theory." International Organization 41, no. 3 (1987): 335–70. http://dx.doi.org/10.1017/s002081830002751x.

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While neorealism and world-system theory both claim to be “structural” theories of international relations, they embody very different understandings of system structure and structural explanation. Neorealists conceptualize system structures in individualist terms as constraining the choices of preexisting state agents, whereas world-system theorists conceptualize system structures in structuralist terms as generating state agents themselves. These differences stem from what are, in some respects, fundamentally opposed solutions to the “agent-structure” or “micromacro” problem. This opposition, however, itself reflects a deeper failure of each theory to recognize the mutually constitutive nature of human agents and system structures—a failure which leads to deep-seated inadequacies in their respective explanations of state action. An alternative solution to the agent-structure problem, adapted from “structuration theory” in sociology, can overcome these inadequacies by avoiding both the reduction of system structures to state actors in neorealism and their reification in world-system theory. Structuration theory requires a philosophical basis in scientific realism, arguably the “new orthodoxy” in the philosophy of natural science, but as yet largely unrecognized by political scientists. The scientific realist/structuration approach generates an agenda for “structural-historical” research into the properties and dispositions of both state actors and the system structures in which they are embedded.

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Stakhovskaya, L. V., I. V. Tikhonova, and V. V. Gnezditsky. "Results of toposelective eeg mapping of patients with transitional global amnesia and discirculatory encephalopathy." Neurology Bulletin XXVII, no. 3-4 (July 15, 1995): 5–9. http://dx.doi.org/10.17816/nb78745.

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Correlating tBe data of toposelective mapping of electrical brain activity in patients witB transitional global amnesia (TGA) and in patients of control group witB discirculatory encephalopathy revealed that type IV curves prevail in patients with TGA (44%), and type I (44%) and III (28%) in patients of control group. Besides, in patients of the main group the mean value of slow to fast activity index in the left occipital region is certainly smaller, and the mean alpha-rythm value of peak frequency in the right occipital region is certainly greater than in patients of the control group. It is the authors' opinion that the revealed distinctions can point to the involvement of deep-seated brain structures and mediobasal regions of frontal and temporal lobes in pathologic process of TGA.

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Patel, Samir H., Jack Rock, and Samuel Ryu. "Spine radiosurgery and dose tolerance to the spinal cord." JBNC - JORNAL BRASILEIRO DE NEUROCIRURGIA 20, no. 2 (March 12, 2018): 161–68. http://dx.doi.org/10.22290/jbnc.v20i2.741.

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Radiosurgery is the utmost form of targeted radiation treatment that can eradicate the gross tumors, and it is a non-invasive procedure. It requires a high degree of accuracy and precision in targeting the deep-seated tumors which are usually surrounded by the functionally important normal structures. Recent advances of immobilization method and computerizedradiation delivery method with intensity modulation made it possible to perform radiosurgery to the spine. Spine radiosurgery achieved a rapid and durable pain control in majority of patients with spine metastasis. Radiosurgical decompression of the epidural spinal cord compression improved neurological function and ambulation. The most critical constraint of spine radiosurgery is the potential damage to the spinal cord. Nevertheless, the procedure is proven safe and complication has been minimal. Spine radiosurgery can be used for both malignant and benign tumors of the spinal column.

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Rychagov, S. N., E. I. Sandimirova, M. S. Chernov, O. V. Kravchenko, and E. V. Kartasheva. "The Composition, Structure, and Origin of Carbonate Concretions Sampled in the South Kambalnyi Central Thermal Field, Kamchatka." Journal of Volcanology and Seismology 15, no. 4 (July 2021): 258–72. http://dx.doi.org/10.1134/s0742046321040059.

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Abstract Carbonate concretions are formed at the base of a sequence of hydrothermal clay in the South Kambalnyi Central Thermal Field situated in the southern part of the Kambalnyi volcanic mountain range, Kamchatka. The concretions have complex chemical and mineral compositions: apart from aragonite which is the main component of each layer, the chemical compounds identified there include oxides of iron and silicon, sulfates of calcium and barium, sulfides of iron and other metals, carbonates of iron and manganese, siliceous ferromanganese formations, nitrogen compounds, and phosphates of calcium and rare metals. The concretions have diverse structures and textures that indicate a multiphase character of formation for these mineral aggregates. It is thought that their formation was due to the discharge of deep-seated alkaline metalliferous solutions in a zone of rock argillization of the South Kambalnyi Central Thermal Field.

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Takayama, Yutaro, Naoki Ikegaya, Keiya Iijima, Yuiko Kimura, Suguru Yokosako, Norihiro Muraoka, Kenzo Kosugi, Yuu Kaneko, Tetsuya Yamamoto, and Masaki Iwasaki. "Single-Institutional Experience of Chronic Intracranial Electroencephalography Based on the Combined Usage of Subdural and Depth Electrodes." Brain Sciences 11, no. 3 (February 28, 2021): 307. http://dx.doi.org/10.3390/brainsci11030307.

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Implantation of subdural electrodes on the brain surface is still widely performed as one of the “gold standard methods” for the presurgical evaluation of epilepsy. Stereotactic insertion of depth electrodes to the brain can be added to detect brain activities in deep-seated lesions to which surface electrodes are insensitive. This study tried to clarify the efficacy and limitations of combined implantation of subdural and depth electrodes in intractable epilepsy patients. Fifty-three patients with drug-resistant epilepsy underwent combined implantation of subdural and depth electrodes for long-term intracranial electroencephalography (iEEG) before epilepsy surgery. The detectability of early ictal iEEG change (EIIC) were compared between the subdural and depth electrodes. We also examined clinical factors including resection of MRI lesion and EIIC with seizure freedom. Detectability of EIIC showed no significant difference between subdural and depth electrodes. However, the additional depth electrode was useful for detecting EIIC from apparently deep locations, such as the insula and mesial temporal structures, but not in detecting EIIC in patients with ulegyria (glial scar). Total removal of MRI lesion was associated with seizure freedom. Depth electrodes should be carefully used after consideration of the suspected etiology to avoid injudicious usage.

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T, Aga, and Haruna A. I. "The field geology and petrography of the kofayi younger granite complex, central Nigeria." International Journal of Advanced Geosciences 7, no. 2 (July 22, 2019): 95. http://dx.doi.org/10.14419/ijag.v7i2.29055.

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The Kofayi Younger Granite Complex is one of the several anorogenic alkaline Younger Granite Complexes that is located approximately 45 kilometres north east of Jos, Nigeria. The complex is found to comprise of felsic rocks like; biotite-granites, biotite microgranites and granodiorites. They are also found to be associated with mafic rocks like diorites which, at some portions have formed hybrid rocks. Quartz- feldspar- granites are the porphyritic rocks that found in the ring complex. The complex intrude the basement rocks of central Nigeria. Structural trends on these rocks suggest that they were controlled by some deep seated structures of the basement. Mineral suite identified include; fayalite, pyroxene, amphibole, k-feldspar, biotite, quartz, iron- oxide and accessory minerals like zircon, apatite, and allanite. Generally, the petrography of these rock samples reveal the presence of a mafic magma which has two pulses (a mafic and felsic pulse) of injection.

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Journal articles on the topic 'Deep-seated Structures'

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