Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

PubMed

Tanaka, Y; Miyazawa, Y; Hashimoto, R; Nakano, I; Obayashi, T

1999-07-22

Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. To search for new anatomic substrates for focal retrograde amnesia. We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

Selecting Random Distributed Elements for HIFU using Genetic Algorithm

NASA Astrophysics Data System (ADS)

Zhou, Yufeng

2011-09-01

As an effective and noninvasive therapeutic modality for tumor treatment, high-intensity focused ultrasound (HIFU) has attracted attention from both physicians and patients. New generations of HIFU systems with the ability to electrically steer the HIFU focus using phased array transducers have been under development. The presence of side and grating lobes may cause undesired thermal accumulation at the interface of the coupling medium (i.e. water) and skin, or in the intervening tissue. Although sparse randomly distributed piston elements could reduce the amplitude of grating lobes, there are theoretically no grating lobes with the use of concave elements in the new phased array HIFU. A new HIFU transmission strategy is proposed in this study, firing a number of but not all elements for a certain period and then changing to another group for the next firing sequence. The advantages are: 1) the asymmetric position of active elements may reduce the side lobes, and 2) each element has some resting time during the entire HIFU ablation (up to several hours for some clinical applications) so that the decreasing efficiency of the transducer due to thermal accumulation is minimized. Genetic algorithm was used for selecting randomly distributed elements in a HIFU array. Amplitudes of the first side lobes at the focal plane were used as the fitness value in the optimization. Overall, it is suggested that the proposed new strategy could reduce the side lobe and the consequent side-effects, and the genetic algorithm is effective in selecting those randomly distributed elements in a HIFU array.

Neuropsychological functioning and brain energetics of drug resistant mesial temporal lobe epilepsy patients.

PubMed

Osório, Camila Moreira; Latini, Alexandra; Leal, Rodrigo Bainy; de Oliveira Thais, Maria Emília Rodrigues; Vascouto, Helena Dresch; Remor, Aline Pertile; Lopes, Mark William; Linhares, Marcelo Neves; Ben, Juliana; de Paula Martins, Roberta; Prediger, Rui Daniel; Hoeller, Alexandre Ademar; Markowitsch, Hans Joachim; Wolf, Peter; Lin, Kátia; Walz, Roger

2017-12-01

Interictal hypometabolism is commonly measured by 18-fluoro-deoxyglucose Positron Emission Tomography (FDG-PET) in the temporal lobe of patients with mesial temporal lobe epilepsy (MTLE-HS). Left temporal lobe interictal FDG-PET hypometabolism has been associated with verbal memory impairment, while right temporal lobe FDG-PET hypometabolism is associated with nonverbal memory impairment. The biochemical mechanisms involved in these findings remain unknown. In comparison to healthy controls (n=21), surgically treated patients with MTLE-HS (n=32, left side=17) had significant lower scores in the Rey Auditory Verbal Learning Test (RAVLT retention and delayed), Logical Memory II (LMII), Boston Naming test (BNT), Letter Fluency and Category Fluency. We investigated whether enzymatic activities of the mitochondrial enzymes Complex I (C I), Complex II (C II), Complex IV (C IV) and Succinate Dehydrogenase (SDH) from the resected samples of the middle temporal neocortex (mTCx), amygdala (AMY) and hippocampus (HIP) were associated with performance in the RAVLT, LMII, BNT and fluency tests of our patients. After controlling for the side of hippocampus sclerosis, years of education, disease duration, antiepileptic treatment and seizure outcome after surgery, no independent associations were observed between the cognitive test scores and the analyzed mitochondrial enzymatic activities (p>0.37). Results indicate that memory and language impairment observed in MTLE-HS patients are not strongly associated with the levels of mitochondrial CI, CII, SDH and C IV enzymatic activities in the temporal lobe structures ipsilateral to the HS lesion. Copyright © 2017 Elsevier B.V. All rights reserved.

Real-time windowing in imaging radar using FPGA technique

NASA Astrophysics Data System (ADS)

Ponomaryov, Volodymyr I.; Escamilla-Hernandez, Enrique

2005-02-01

The imaging radar uses the high frequency electromagnetic waves reflected from different objects for estimating of its parameters. Pulse compression is a standard signal processing technique used to minimize the peak transmission power and to maximize SNR, and to get a better resolution. Usually the pulse compression can be achieved using a matched filter. The level of the side-lobes in the imaging radar can be reduced using the special weighting function processing. There are very known different weighting functions: Hamming, Hanning, Blackman, Chebyshev, Blackman-Harris, Kaiser-Bessel, etc., widely used in the signal processing applications. Field Programmable Gate Arrays (FPGAs) offers great benefits like instantaneous implementation, dynamic reconfiguration, design, and field programmability. This reconfiguration makes FPGAs a better solution over custom-made integrated circuits. This work aims at demonstrating a reasonably flexible implementation of FM-linear signal and pulse compression using Matlab, Simulink, and System Generator. Employing FPGA and mentioned software we have proposed the pulse compression design on FPGA using classical and novel windows technique to reduce the side-lobes level. This permits increasing the detection ability of the small or nearly placed targets in imaging radar. The advantage of FPGA that can do parallelism in real time processing permits to realize the proposed algorithms. The paper also presents the experimental results of proposed windowing procedure in the marine radar with such the parameters: signal is linear FM (Chirp); frequency deviation DF is 9.375MHz; the pulse width T is 3.2μs taps number in the matched filter is 800 taps; sampling frequency 253.125*106 MHz. It has been realized the reducing of side-lobes levels in real time permitting better resolution of the small targets.

Application of CT perfusion to assess hemodynamics in symptomatic Moyamoya syndrome: focus on affected side and parameter characteristic.

PubMed

Huang, Shuran; Gao, Lingyun; Chen, Yueqin; Guo, Xiang; Liu, Deguo; Wang, Jiehuan; Shi, Zhitao; Sun, Zhanguo; Jin, Feng; Chen, Weijian; Yang, Yunjun

2018-01-27

Vascular and hemodynamic changes were not consistent in symptomatic and non-symptomatic cerebral hemisphere in patients with symptomatic moyamoya syndrome (MMS). Thus, the purpose of this study is to evaluate the hemodynamic difference between symptomatic and non-symptomatic cerebral hemisphere in patients with symptomatic MMS. Patients who were diagnosed with symptomatic MMS were retrospectively collected. All cases underwent CTP examination. Regions of interest (ROIs) were chosen in the mirroring bilateral frontal lobes, temporal lobes, the basal ganglia, and the brainstem as control region. The relative perfusion parameter values of symptomatic side were compared with non-symptomatic side. Of the 40 patients, 33 patients were taken into assessment. In all cases (n = 33), rCBF, rMTT, and rTTP in all regions of interest (ROIs) of the symptomatic side were significantly different from those of contralateral side. In unilateral MMS patients (n = 7), rCBF values were not significantly different between two sides in the temporal lobe and basal ganglia area; rTTP values were significantly higher in the symptomatic side. rMTT values were significantly higher only in the temporal lobe of symptomatic side. In bilateral MMS patients (n = 26), rCBF and rMTT in all ROIs of the symptomatic side were significantly different from those of contralateral side. However, there were no significant differences between two sides in all ROIs on rTTP values. This study demonstrates that rCBF and rMTT were more sensitive than rTTP for evaluating hemodynamic changes in patients with symptomatic bilateral MMS. Furthermore, patients with unilateral MMS may have a preserved rCBF compared to those with bilateral disease.

Double-Stage Delay Multiply and Sum Beamforming Algorithm Applied to Ultrasound Medical Imaging.

PubMed

Mozaffarzadeh, Moein; Sadeghi, Masume; Mahloojifar, Ali; Orooji, Mahdi

2018-03-01

In ultrasound (US) imaging, delay and sum (DAS) is the most common beamformer, but it leads to low-quality images. Delay multiply and sum (DMAS) was introduced to address this problem. However, the reconstructed images using DMAS still suffer from the level of side lobes and low noise suppression. Here, a novel beamforming algorithm is introduced based on expansion of the DMAS formula. We found that there is a DAS algebra inside the expansion, and we proposed use of the DMAS instead of the DAS algebra. The introduced method, namely double-stage DMAS (DS-DMAS), is evaluated numerically and experimentally. The quantitative results indicate that DS-DMAS results in an approximately 25% lower level of side lobes compared with DMAS. Moreover, the introduced method leads to 23%, 22% and 43% improvement in signal-to-noise ratio, full width at half-maximum and contrast ratio, respectively, compared with the DMAS beamformer. Copyright © 2018. Published by Elsevier Inc.

Paraxial propagation dynamics of the radially polarized Airy beams in uniaxial crystals orthogonal to the optical axis.

PubMed

Xie, Jintao; Zhang, Jianbin; Zheng, Xitao; Ye, Junran; Deng, Dongmei

2018-04-30

We study the paraxial propagation of the radially polarized Airy beams (RPAiBs) in uniaxial crystals orthogonal to the optical axis analytically and numerically. The propagation trajectory, the intensity and the radiation forces of the RPAiBs are investigated and the properties are elucidated by numerical examples in this paper. Results show that the RPAiBs evolve into the beams produced by the x-direction electric field (RPAiXBs) and the y-direction electric field (PRAiYBs) which are totally different in uniaxial crystals. During the propagation, the intensity of the RPAiXBs transfers from the side lobe in the x-direction to the main lobe and finally returns to the side lobe in the x-direction again, but that of the RPAiYBs transfers from the side lobe in the y-direction to the main lobe and flows to the side lobe in the x-direction at last. The effect of the intensity focusing for the RPAiXBs can be modulated by the ratio of the extraordinary index (ne) to the ordinary index (no) in anisotropic medium, which contributes to the intensity focusing of the RPAiBs in a short distance a lot. We can adjust the intensity distribution especially the focusing position, the propagation trajectory and the radiation forces distributions of the RPAiXBs through choosing an appropriate value of the ratio of ne to no to meet the actual usage accordingly.

Non-invasive evaluation of the effects of opening & closing of eyes, and of exposure to a minute light beam, as well as to electrical or magnetic field on the melatonin, serotonin, & other neuro-transmitters of human pineal gland representation areas & the heart.

PubMed

Omura, Y; Losco, B M; Takeshige, C

1993-01-01

Using the Bi-Digital O-Ring Test electromagnetic resonance phenomena between 2 identical substances, first the pineal gland representational (rep.) areas were localized on the 5 different locations on the surface of the head using microscope slides of the pineal gland or Melatonin (while the eyes are closed) as a reference control substance. The 3 pineal rep. areas along the mid-line of the head always showed two lobes connected as a "Dumbbell" shape, with one round or oval area at each side of the mid-line. From each side of the head, anterior and superior to the ear, it appeared in a shape resembling the side view of a pineal gland. When both eyes were open, Melatonin, Norepinephrine (NE), and Acetylcholine (ACh) markedly decreased, while Serotonin, Dopamine, and GABA increased significantly in the outer part of the pineal gland rep. areas. When both eyes were closed, Melatonin, NE and ACh increased markedly, with marked decrease in Serotonin, Dopamine and GABA in the outer part of the pineal gland rep. areas. However, in the inner core of the pineal gland rep. area, an opposite response was found. Thus, the pineal gland has 2 main lobes, and functionally each lobe seems to have two concentric areas with an inverse relationship, i.e., a "Functional Cortex" area and a "Functional Core" area. The biochemical changes between the cortex and the core are in an inverse relationship. Melatonin was also found in the S-A node & right side of normal heart when the eyes were closed. When the eyes were open, Melatonin was found in the left side of the heart, as well as the salivary glands, stomach, colon, etc. While both eyes were closed, when a weak light beam was exposed at different parts of the body, such as any part of the upper and lower extremities, Melatonin, NE, and ACh decreased, with an increase in Serotonin, GABA and Dopamine only in the functional cortices of the pineal gland lobes on the same side of the body. Even when both eyes were open, if a very weak narrow beam of light was exposed on any part of the body, Melatonin, NE and ACh decreased, while Serotonin, Dopamine and GABA increased compared with pre-exposure level in only the functional cortices of the pineal gland lobes in the same side of the light exposure, and the opposite effect was also observed in the functional core of the light exposed side only.(ABSTRACT TRUNCATED AT 400 WORDS)

Left lobe of the prostate during clinical prostate cancer screening: the dark side of the gland for right-handed examiners.

PubMed

Ploussard, G; Nicolaiew, N; Mongiat-Artus, P; Terry, S; Allory, Y; Vacherot, F; Abbou, C-C; Desgrandchamps, F; Salomon, L; de la Taille, A

2014-06-01

The predictive value of the abnormality side during digital rectal examination (DRE) has never been studied, suggesting that physicians examined the left lobe of the gland as well as the right lobe. We aimed to assess the predictive value of the side of DRE abnormality for prostate cancer (PCa) detection and aggressiveness in right-handed urologists. An analysis of a prospective database was carried out that included all consecutive men undergoing prostate biopsies between 2001 and 2012. The main end point was the predictive value of the abnormality side during DRE for cancer detection in clinically suspicious unilateral T2 disease. The diagnostic performance of left- versus right-sided abnormality was also assessed in terms of sensitivity, specificity and negative/positive predictive values. Overall, 308 patients had a suspicious unilateral clinical disease (detection rate 57.5%). The cancer detection rate was significantly higher in case of left-sided compared with right-sided clinical T2 stage (odds ratio 2.1). In case of left-sided disease, the number of positive cores, the rate of perineural invasion, the rate of primary grade 4 pattern and the percentage of cancer involvement per core were significantly higher compared with those reported for right-sided disease. The predictive value of abnormality laterality for cancer detection and aggressiveness remained statistically independent in multivariate models. The positive predictive value for cancer detection was 64.6 in case of suspicious left-sided disease versus 46.9 in case of right-sided disease. The risks of detecting PCa and aggressive disease on biopsy are significantly higher when DRE reveals a suspicious left-sided clinical disease as compared with right-sided disease. Right-handed physicians should be aware of this variance in diagnostic performance and potential underdetection of left-sided clinical disease, and should improve their examination of the left lobe of the gland by conducting longer exams or changing the patient's position.

[Clinical characteristics of epileptic seizures in insular gliomas].

PubMed

Buklina, S B; Bykanov, A E; Pitskhelauri, D I

To study the characteristics of epileptic seizures in insular gliomas. Forty-five patients with insular gliomas were examined. The spread of a tumor was established by MRI results and intraoperational findings. A tumor within the insular only was found in 9 out of 45 patients (7 left-sided and 2 right-sided). In 36 patients, a tumor slightly spread into temporal lobe pole and medial-basal regions of the frontal lobe (27 left-sided and 18 right-sided). The control group consisted of 50 patients with tumors of temporal and frontal lobes. Paroxysmal symptoms were similar in patients with tumors of the insular and patients with tumors of temporal lobes. Seizures in patients with frontal lobe tumors differed significantly from insular and temporal tumors, with the exception of a tumor localized in the opercula area. The following quantitative differences were identified: different forms of unconsciousness were significantly less frequent in symptomatic epilepsy in patients with insular tumor than in epilepsy caused by temporal lobe tumors (36% of patients vs 84% in temporal tumors (p<0.0001)). In patients with insular tumors, olfactory and taste hallucinations occur more often compared to temporal lobe tumors (51% vs 16% (p<0.003). The frequency of paroxysmal seizures of fear and anxiety in patients with those tumors was similar (20% with insular tumors and 14 with temporal tumors). An autonomic component of episeizures did not differ between tumors of both localizations. Olfactory and taste hallucinations were qualitatively similar in insular and temporal lobe tumors: smell and taste were unpleasant or associated with a danger: smell of burning, gas, something spoiled, sour, tart chemistry, taste of somethong metallic, chemical, sour. No pleasant smell or taste were reported. Epileptic seizures in insular tumors had similarities and certain differences compared with temporal seizures that well reflect function of the insula and its links, in the first turn, with limbic system structures.

Context sensitive formulations of antenna pattern correction and side lobe compensation for NOSS/LAMMR real time processing

NASA Technical Reports Server (NTRS)

Chin, R. T.; Beaudet, P. R.

1981-01-01

Large antenna multi-channel microwave radiometer (LAMMR) software specifications were written for LAMMR ground processing. There is a need to determine more computationally-efficient antenna temperature correction methods in compensating side lobe contributions especially near continents, islands and weather fronts. One of the major conclusions was that the antenna pattern corrections (APC) processes did not accomplish the implied goals of compensating for the antenna side lobe influences on brightness temperature. A-priori knowledge of land/water locations was shown to be needed and had to be incorporated in a context sensitive APC process if the artifacts caused by land presence is to be avoided. The high temperatures in land regions can severely bias the lower ocean response.

LATERAL OFFSET OF THE CORONAL MASS EJECTIONS FROM THE X-FLARE OF 2006 DECEMBER 13 AND ITS TWO PRECURSOR ERUPTIONS

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

Sterling, Alphonse C.; Moore, Ronald L.; Harra, Louise K., E-mail: alphonse.sterling@nasa.gov, E-mail: ron.moore@nasa.gov, E-mail: lkh@mssl.ucl.ac.uk

2011-12-10

Two GOES sub-C-class precursor eruptions occurred within {approx}10 hr prior to and from the same active region as the 2006 December 13 X4.3-class flare. Each eruption generated a coronal mass ejection (CME) with center laterally far offset ({approx}> 45 Degree-Sign ) from the co-produced bright flare. Explaining such CME-to-flare lateral offsets in terms of the standard model for solar eruptions has been controversial. Using Hinode/X-Ray Telescope (XRT) and EUV Imaging Spectrometer (EIS) data, and Solar and Heliospheric Observatory (SOHO)/Large Angle and Spectrometric Coronagraph (LASCO) and Michelson Doppler Imager (MDI) data, we find or infer the following. (1) The first precursormore » was a 'magnetic-arch-blowout' event, where an initial standard-model eruption of the active region's core field blew out a lobe on one side of the active region's field. (2) The second precursor began similarly, but the core-field eruption stalled in the side-lobe field, with the side-lobe field erupting {approx}1 hr later to make the CME either by finally being blown out or by destabilizing and undergoing a standard-model eruption. (3) The third eruption, the X-flare event, blew out side lobes on both sides of the active region and clearly displayed characteristics of the standard model. (4) The two precursors were offset due in part to the CME originating from a side-lobe coronal arcade that was offset from the active region's core. The main eruption (and to some extent probably the precursor eruptions) was offset primarily because it pushed against the field of the large sunspot as it escaped outward. (5) All three CMEs were plausibly produced by a suitable version of the standard model.« less

Superficial Temporal Artery-Superior Cerebellar Artery Bypass with Anterior Petrosectomy.

PubMed

Hokari, Masaaki; Asaoka, Katsuyuki; Shimbo, Daisuke; Uchida, Kazuki; Itamoto, Koji

2018-06-01

Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is associated with a relatively high risk of surgical complications, such as hematoma and/or edema caused by temporal lobe retraction. Therefore, the right side is typically used to avoid retraction of the left temporal lobe. In this report, we present a case of left STA-SCA bypass with anterior petrosectomy to avoid retraction of dominant-side temporal lobe and describe the surgical technique in detail. A 69-year-old man presented with gradual worsening of dysarthria and gait disturbance. Magnetic resonance imaging showed no signs of acute infarction, but digital subtraction angiography showed severe stenosis of basilar artery and faint flow in the distal basilar artery. On 3-dimensional computed tomography angiography, posterior communicating arteries were not visualized; we could identify the left SCA, but not the right SCA. Despite dual antiplatelet therapy, a small fresh brainstem infarct was detected 10 days after admission. To avert fatal brainstem infarction and further enlargement of the infarct, we performed left STA-SCA bypass with anterior petrosectomy to avoid retraction of the dominant-side temporal lobe. Postoperative imaging revealed no new lesions, such as infarction or temporal lobe contusional hematoma, and confirmed the patency of the bypass. Postoperative single-photon emission computed tomography demonstrated improved cerebral blood flow in the posterior circulation. The patient was transferred to another hospital for rehabilitation. This method helps minimize the risk of injury to the temporal lobe, especially that of the dominant side. Copyright © 2018. Published by Elsevier Inc.

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

Wicks, Christopher Donald; Madin, Mark Michael

A cam carrier assembly includes a cylinder head having valves and a camshaft having lobes. A cam carrier has a first side coupled with the cylinder head engaging around the valves and a second side with bearing surfaces supporting the camshaft. A series of apertures extend between the first and second sides for the lobes to interface with the valves. The cam carrier is made of carbon fiber composite insulating the camshaft from the cylinder head and providing substantial weight reduction to an upper section of an associated engine.

Auditory cortical activation and plasticity after cochlear implantation measured by PET using fluorodeoxyglucose.

PubMed

Łukaszewicz-Moszyńska, Zuzanna; Lachowska, Magdalena; Niemczyk, Kazimierz

2014-01-01

The purpose of this study was to evaluate possible relationships between duration of cochlear implant use and results of positron emission tomography (PET) measurements in the temporal lobes performed while subjects listened to speech stimuli. Other aspects investigated were whether implantation side impacts significantly on cortical representations of functions related to understanding speech (ipsi- or contralateral to the implanted side) and whether any correlation exists between cortical activation and speech therapy results. Objective cortical responses to acoustic stimulation were measured, using PET, in nine cochlear implant patients (age range: 15 to 50 years). All the patients suffered from bilateral deafness, were right-handed, and had no additional neurological deficits. They underwent PET imaging three times: immediately after the first fitting of the speech processor (activation of the cochlear implant), and one and two years later. A tendency towards increasing levels of activation in areas of the primary and secondary auditory cortex on the left side of the brain was observed. There was no clear effect of the side of implantation (left or right) on the degree of cortical activation in the temporal lobe. However, the PET results showed a correlation between degree of cortical activation and speech therapy results.

Auditory cortical activation and plasticity after cochlear implantation measured by PET using fluorodeoxyglucose

PubMed Central

Łukaszewicz-Moszyńska, Zuzanna; Lachowska, Magdalena; Niemczyk, Kazimierz

2014-01-01

Summary The purpose of this study was to evaluate possible relationships between duration of cochlear implant use and results of positron emission tomography (PET) measurements in the temporal lobes performed while subjects listened to speech stimuli. Other aspects investigated were whether implantation side impacts significantly on cortical representations of functions related to understanding speech (ipsi- or contralateral to the implanted side) and whether any correlation exists between cortical activation and speech therapy results. Objective cortical responses to acoustic stimulation were measured, using PET, in nine cochlear implant patients (age range: 15 to 50 years). All the patients suffered from bilateral deafness, were right-handed, and had no additional neurological deficits. They underwent PET imaging three times: immediately after the first fitting of the speech processor (activation of the cochlear implant), and one and two years later. A tendency towards increasing levels of activation in areas of the primary and secondary auditory cortex on the left side of the brain was observed. There was no clear effect of the side of implantation (left or right) on the degree of cortical activation in the temporal lobe. However, the PET results showed a correlation between degree of cortical activation and speech therapy results. PMID:25306122

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

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

Here, we numerically investigate the resonance and vibration characteristics of radial modes of laterally stiffened piezoelectric disc transducers. Lateral stiffening is modeled using a spring and vibration characteristics of the piezo-disc are investigated with increasing lateral stiffness. It is found that the resonant frequency response of the radial modes follows an asymptotic behavior approaching that of a clamped disc with increasing lateral stiffness. The radial mode vibration pattern of the discs is also found to be affected by lateral stiffness. While the vibration pattern of a free disc corresponds to a Bessel function, laterally stiffened discs show edge-effects where theymore » depart from the Bessel-like behavior. In addition, a fully clamped piezo-disc is found to have an extra side-lobe when compared to a free disc. Ultrasonic beam profiles generated from radial modes of laterally stiffened discs are numerically investigated. It is found that the free piezo-disc generates a Bessel beam that has multiple side-lobes. Increasing the lateral stiffness results in a significant reduction of side-lobes in the beam profile. This technique of generating a collimated beam with side-lobe reduction finds significant applications in imaging through concrete, drilling mud, and other highly attenuating materials.« less

Optimum concentric circular array antenna with high gain and side lobe reduction at 5.8 GHz

NASA Astrophysics Data System (ADS)

Zaid, Mohammed; Rafiqul Islam, Md; Habaebi, Mohamed H.; Zahirul Alam, AHM; Abdullah, Khaizuran

2017-11-01

The significance of high gain directional antennas stems from the need to cope up with the everyday progressing wireless communication systems. Due to low gain of the widely used microstrip antenna, combining multiple antennas in proper geometry increases the gain with good directive property. Over other array forms, this paper uses concentric circular array configuration for its compact structure and inherent symmetry in azimuth. This proposed array is composed of 9 elements on FR-4 substrate, which is designed for WLAN applications at 5.8GHz. Antenna Magus software is used for synthesis, while CST software is used for optimization. The proposed array is designed with optimum inter-element spacing and number of elements achieving a high directional gain of 15.7 dB compared to 14.2 dB of available literature, with a high reduction in side lobe level of -17.6 dB.

HST NICMOS Observations of the Polarization of NGC 1068

NASA Technical Reports Server (NTRS)

Simpson, Janet P.; Colgan, Sean W. J.; Erickson, Edwin F.; Hines, Dean C.; Schultz, A. S. B.; Trammell, Susan R.; DeVincenzi, D. (Technical Monitor)

2002-01-01

We have observed the polarized light at 2 microns in the center of NGC 1068 with HST (Hubble Space Telescope) NICMOS (Near Infrared Camera Multi Object Spectrometer) Camera 2. The nucleus is dominated by a bright, unresolved source, polarized at a level of 6.0 +/- 1.2% with a position angle of 122 degrees +/- 1.5 degrees. There are two polarized lobes extending tip to 8" northeast and southwest of the nucleus. The polarized flux in both lobes is quite clumpy, with the maximum polarization occurring in the southwest lobe at a level of 17% when smoothed to 0.23" resolution. The perpendiculars to the polarization vectors in these two lobes point back to the intense unresolved nuclear source to within one 0.076" Camera 2 pixel, thereby confirming that this source is the origin of the scattered light and therefore the probable AGN (Active Galactic Nuclei) central engine. Whereas the polarization of the nucleus is probably caused by dichroic absorption, the polarization in the lobes is almost certainly caused by scattering, with very little contribution from dichroic absorption. Features in the polarized lobes include a gap at a distance of about 1" from the nucleus toward the southwest lobe and a "knot" of emission about 5" northwest of the nucleus. Both features had been discussed by groundbased observers, but they are much better defined with the high spatial resolution of NICMOS. The northeast knot may be the side of a molecular cloud that is facing the nucleus, which cloud may be preventing the expansion of the northeast radio lobe at the head of the radio synchrotron-radiation-emitting jet. We also report the presence of two ghosts in the Camera 2 polarizers.

ECCM Waveform Investigation

DTIC Science & Technology

1977-08-01

period, duration/ peak power, and side lobe levels. A recommended waveform library is presented. One of the program results is that an optimum waveform...Areas a. Coding b. Pulse Repetition Period c. Peak Power/Pulse Duration d. Sidelobes 3. Performance Dependence Upon Bandwidth/Bandspan a... peak power and pulse duration, and range and Doppler sldelobe levels. The constraints upon waveforms due to the In- ability of the radar components

Risk factors for spatial memory impairment in patients with temporal lobe epilepsy.

PubMed

Amlerova, Jana; Laczo, Jan; Vlcek, Kamil; Javurkova, Alena; Andel, Ross; Marusic, Petr

2013-01-01

At present, the risk factors for world-centered (allocentric) navigation impairment in patients with temporal lobe epilepsy (TLE) are not known. There is some evidence on the importance of the right hippocampus but other clinical features have not been investigated yet. In this study, we used an experimental human equivalent to the Morris water maze to examine spatial navigation performance in patients with drug-refractory unilateral TLE. We included 47 left-hemisphere speech dominant patients (25 right sided; 22 left sided). The aim of our study was to identify clinical and demographic characteristics of TLE patients who performed poorly in allocentric spatial memory tests. Our results demonstrate that poor spatial navigation is significantly associated with younger age at epilepsy onset, longer disease duration, and lower intelligence level. Allocentric navigation in TLE patients was impaired irrespective of epilepsy lateralization. Good and poor navigators did not differ in their age, gender, or preoperative/postoperative status. This study provides evidence on risk factors that increase the likelihood of allocentric navigation impairment in TLE patients. The results indicate that not only temporal lobe dysfunction itself but also low general cognitive abilities may contribute to the navigation impairment. Copyright © 2012 Elsevier Inc. All rights reserved.

Influence of anxiety on memory performance in temporal lobe epilepsy

PubMed Central

Brown, Franklin C.; Westerveld, Michael; Langfitt, John T.; Hamberger, Marla; Hamid, Hamada; Shinnar, Shlomo; Sperling, Michael R.; Devinsky, Orrin; Barr, William; Tracy, Joseph; Masur, David; Bazil, Carl W.; Spencer, Susan S.

2013-01-01

This study examined the degree to which anxiety contributed to inconsistent material-specific memory difficulties among 243 temporal lobe epilepsy patients from the Multisite Epilepsy Study. Visual memory performance on the Rey Complex Figure Test (RCFT) was lower for those with high versus low level of anxiety, but was not found to be related to side of TLE. Verbal memory on the California Verbal Learning Test (CVLT) was significantly lower for left than right TLE patients with low anxiety, but equally impaired for those with high anxiety. These results suggest that we can place more confidence in the ability of verbal memory tests like the CVLT to lateralize to left TLE for those with low anxiety, but that verbal memory will be less likely to produce lateralizing information for those with high anxiety. This suggests that more caution is needed when interpreting verbal memory tests for those with high anxiety. These results indicated that RCFT performance was significantly affected by anxiety and did not lateralize to either side, regardless of anxiety level. This study adds to the existing literature which suggests that drawing-based visual memory tests do not lateralize among TLE patients, regardless of anxiety level. PMID:24291525

Carbocyanine dye labeling reveals a new motor nucleus in octopus brain.

PubMed

Robertson, J D; Schwartz, O M; Lee, P

1993-02-22

This work aims at a better understanding of the organization of the brain of Octopus vulgaris, emphasizing the touch and visual learning centers. We injected the carbocyanine dye, DiI, into the cerebrobrachial connectives and, separately, into the brachial nerves of living octopuses. In both experiments, retrogradely transported granules of DiI appeared in motor neurons in the superior buccal, posterior buccal and subvertical lobes and in a hitherto unsuspected motor nucleus of several hundred neurons in the posterior dorsal basal and median basal lobes. In addition we labeled afferent fibers by injecting DiI into the caudal (sensory) division of the cerebrobrachial connective on one side; the label spread throughout the superior buccal, posterior buccal and the lateral and median inferior frontal lobes mainly on the injected side. It extended through the cerebral tract into the subvertical lobe, into the superior frontal lobe through the interfrontal tract, through the posterior buccal commissure into the opposite posterior buccal lobe and into the median inferior frontal lobe. The work suggests a new function for the posterior dorsal and median basal lobes, which are shown for the first time to project through the inferior frontal lobe system into the brachial nerves. In addition it represents the first full report of the successful use of the carbocyanine dyes DiI and DiO for labeling nerve tissue in a live invertebrate animal.

Radial modes of laterally stiffened piezoelectric disc transducers for ultrasonic collimated beam generation

DOE PAGES

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

2017-07-15

Here, we numerically investigate the resonance and vibration characteristics of radial modes of laterally stiffened piezoelectric disc transducers. Lateral stiffening is modeled using a spring and vibration characteristics of the piezo-disc are investigated with increasing lateral stiffness. It is found that the resonant frequency response of the radial modes follows an asymptotic behavior approaching that of a clamped disc with increasing lateral stiffness. The radial mode vibration pattern of the discs is also found to be affected by lateral stiffness. While the vibration pattern of a free disc corresponds to a Bessel function, laterally stiffened discs show edge-effects where theymore » depart from the Bessel-like behavior. In addition, a fully clamped piezo-disc is found to have an extra side-lobe when compared to a free disc. Ultrasonic beam profiles generated from radial modes of laterally stiffened discs are numerically investigated. It is found that the free piezo-disc generates a Bessel beam that has multiple side-lobes. Increasing the lateral stiffness results in a significant reduction of side-lobes in the beam profile. This technique of generating a collimated beam with side-lobe reduction finds significant applications in imaging through concrete, drilling mud, and other highly attenuating materials.« less

The lateralising significance of hypergraphia in temporal lobe epilepsy.

PubMed

Roberts, J K; Robertson, M M; Trimble, M R

1982-02-01

Six patients with hypergraphia and epilepsy are presented and their clinical features compared with other patients reported in the literature. It is suggested that hypergraphia occurs more frequently in patients with right-sided non-dominant temporal lobe lesions, in contrast for example to the schizophreniform presentation of left-sided lesions. Other features of psychopathology possibly associated with non-dominant lesions, including elation, hypereligiosity and déjà vu experiences, are also discussed.

Comparison of mechanisms involved in image enhancement of Tissue Harmonic Imaging

NASA Astrophysics Data System (ADS)

Cleveland, Robin O.; Jing, Yuan

2006-05-01

Processes that have been suggested as responsible for the improved imaging in Tissue Harmonic Imaging (THI) include: 1) reduced sensitivity to reverberation, 2) reduced sensitivity to aberration, and 3) reduction in the amplitude of diffraction side lobes. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed and solved using a time-domain code. The numerical simulations were validated through experiments with tissue mimicking phantoms. The impact of aberration from tissue-like media was determined through simulations using three-dimensional maps of tissue properties derived from datasets available through the Visible Female Project. The experiments and simulations demonstrated that second harmonic imaging suffers less clutter from reverberation and side-lobes but is not immune to aberration effects. The results indicate that side lobe suppression is the most significant reason for the improvement of second harmonic imaging.

[Dynamics of functional MRI and speech function in patients after resection of frontal and temporal lobe tumors].

PubMed

Buklina, S B; Batalov, A I; Smirnov, A S; Poddubskaya, A A; Pitskhelauri, D I; Kobyakov, G L; Zhukov, V Yu; Goryaynov, S A; Kulikov, A S; Ogurtsova, A A; Golanov, A V; Varyukhina, M D; Pronin, I N

There are no studies on application of functional MRI (fMRI) for long-term monitoring of the condition of patients after resection of frontal and temporal lobe tumors. The study purpose was to correlate, using fMRI, reorganization of the speech system and dynamics of speech disorders in patients with left hemisphere gliomas before surgery and in the early and late postoperative periods. A total of 20 patients with left hemisphere gliomas were dynamically monitored using fMRI and comprehensive neuropsychological testing. The tumor was located in the frontal lobe in 12 patients and in the temporal lobe in 8 patients. Fifteen patients underwent primary surgery; 5 patients had repeated surgery. Sixteen patients had WHO Grade II and Grade III gliomas; the others had WHO Grade IV gliomas. Nineteen patients were examined preoperatively; 20 patients were examined at different times after surgery. Speech functions were assessed by a Luria's test; the dominant hand was determined using the Annette questionnaire; a family history of left-handedness was investigated. Functional MRI was performed on an HDtx 3.0 T scanner using BrainWavePA 2.0, Z software for fMRI data processing program for all calculations >7, p<0.001. In patients with extensive tumors and recurrent tumors, activation of right-sided homologues of the speech areas cold be detected even before surgery; but in most patients, the activation was detected 3 months or more after surgery. Therefore, reorganization of the speech system took time. Activation of right-sided homologues of the speech areas remained in all patients for up to a year. Simultaneous activation of right-sided homologues of both speech areas, the Broca's and Wernicke's areas, was detected more often in patients with frontal lobe tumors than in those with temporal lobe tumors. No additional activation foci in the left hemisphere were found at the thresholds used to process fMRI data. Recovery of the speech function, to a certain degree, occurred in all patients, but no clear correlation with fMRI data was found. Complex fMRI and neuropsychological studies in 20 patients after resection of frontal and temporal lobe tumors revealed individual features of speech system reorganization within one year follow-up. Probably, activation of right-sided homologues of the speech areas in the presence of left hemisphere tumors depends not only on the severity of speech disorder but also reflects individual involvement of the right hemisphere in enabling speech function. This is confirmed by right-sided activation, according to the fMRI data, in right-sided patients without aphasia and, conversely, the lack of activation of right-sided homologues of the speech areas in several patients with severe postoperative speech disorders during the entire follow-up period.

Phase-locked array of quantum cascade lasers with an integrated Talbot cavity.

PubMed

Wang, Lei; Zhang, Jinchuan; Jia, Zhiwei; Zhao, Yue; Liu, Chuanwei; Liu, Yinghui; Zhai, Shenqiang; Ning, Zhuo; Xu, Xiangang; Liu, Fengqi

2016-12-26

We show a phase-locked array of three quantum cascade lasers with an integrated Talbot cavity at one side of the laser array. The coupling scheme is called diffraction coupling. By controlling the length of Talbot to be a quarter of Talbot distance (Z_t/4), in-phase mode operation can be selected. The in-phase operation shows great modal stability under different injection currents, from the threshold current to the full power current. The far-field radiation pattern of the in-phase operation contains three lobes, one central maximum lobe and two side lobes. The interval between adjacent lobes is about 10.5°. The output power is about 1.5 times that of a single-ridge laser. Further studies should be taken to achieve better beam performance and reduce optical losses brought by the integrated Talbot cavity.

Side-to-Side Tracheobronchoplasty to Reconstruct Complex Congenital Tracheobronchial Stenosis.

PubMed

Ragalie, William S; Chun, Robert H; Martin, Timothy; Ghanayem, Nancy S; Berens, Richard J; Beste, David J; Mitchell, Michael E

2017-08-01

Long segment tracheobronchial stenosis is a rare congenital anomaly that can also occur in combination with abnormal bronchial arborization. Long segment tracheal reconstruction in the setting of a supernumerary bridging bronchus has been reported; however, these repairs can be particularly complex. We present our experience using the bridging bronchus to augment long segment tracheal stenosis with a side-to-side tracheobronchoplasty. Four patients with complex long segment tracheobronchial stenosis involving a bronchus suis (right upper lobe bronchus) and a bridging bronchus presented with refractory respiratory distress requiring urgent tracheal reconstruction. Patient 1 was initially managed with modified slide tracheoplasty and tracheostomy. Patients 2, 3, and 4 were managed with single-stage procedures. All patients underwent definitive long segment tracheobronchoplasty consisting of a side-to-side anastomosis between the bridging bronchus and the right upper lobe bronchus. Age at surgery was 569, 69, 24, and 142 days, respectively. Weight at surgery was 9.3, 4.3, 2.7, and 5.9 kg. All patients were weaned from mechanical ventilation at 84, 13, 47, and 8 days after side-to-side tracheobronchoplasty. All patients were alive and free from tracheostomy at follow-up of 6.7, 3.8, 2.7, and 0.5 years. Side-to-side tracheal reconstruction is feasible in severe cases of long segment tracheal stenosis with a right upper lobe bronchus and a bridging bronchus. This technique can be successfully applied in high-risk patients and in the neonatal period and can provide excellent midterm results. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

The lateralising significance of hypergraphia in temporal lobe epilepsy

PubMed Central

Roberts, JKA; Robertson, MM; Trimble, MR

1982-01-01

Six patients with hypergraphia and epilepsy are presented and their clinical features compared with other patients reported in the literature. It is suggested that hypergraphia occurs more frequently in patients with right-sided non-dominant temporal lobe lesions, in contrast for example to the schizophreniform presentation of left-sided lesions. Other features of psychopathology possibly associated with non-dominant lesions, including elation, hypereligiosity and déjà vu experiences, are also discussed. PMID:7069424

Morphology, structure, composition and build-up processes of the active channel-mouth lobe complex of the Congo deep-sea fan with inputs from remotely operated underwater vehicle (ROV) multibeam and video surveys

NASA Astrophysics Data System (ADS)

Dennielou, Bernard; Droz, Laurence; Babonneau, Nathalie; Jacq, Céline; Bonnel, Cédric; Picot, Marie; Le Saout, Morgane; Saout, Yohan; Bez, Martine; Savoye, Bruno; Olu, Karine; Rabouille, Christophe

2017-08-01

The detailed structure and composition of turbiditic channel-mouth lobes is still largely unknown because they commonly lie at abyssal water depths, are very thin and are therefore beyond the resolution of hull-mound acoustic tools. The morphology, structure and composition of the Congo turbiditic channel-mouth lobe complex (90×40 km; 2525 km2) were investigated with hull-mounted swath bathymetry, air gun seismics, 3.5 kHz sub-bottom profiler, sediment piston cores and also with high-resolution multibeam bathymetry and video acquired with a Remote Operating Vehicle (ROV). The lobe complex lies 760 km off the Congo River mouth in the Angola abyssal plain between 4740 and 5030 m deep. It is active and is fed by turbidity currents that deposit several centimetres of sediment per century. The lobe complex is subdivided into five lobes that have prograded. The lobes are dominantly muddy. Sand represents ca. 13% of the deposits and is restricted to the feeding channel and distributaries. The overall lobe body is composed of thin muddy to silty turbidites. The whole lobe complex is characterized by in situ mass wasting (slumps, debrites). The 1-m-resolution bathymetry shows pervasive slidings and block avalanches on the edges of the feeding channel and the channel mouth indicating that sliding occurs early and continuously in the lobe build-up. Mass wasting is interpreted as a consequence of very-high accumulation rates, over-steepening and erosion along the channels and is therefore an intrinsic process of lobe building. The bifurcation of feeding channels is probably triggered when the gradient in the distributaries at the top of a lobe becomes flat and when turbidity currents find their way on the higher gradient on the lobe side. It may also be triggered by mass wasting on the lobe side. When a new lobe develops, the abandoned lobes continue to collect significant turbiditic deposits from the feeding channel spillover, so that the whole lobe complex remains active. A conceptual lithostratigraphic model is proposed for five morpho-sedimentary environments: lobe rims, lobe body, distributaries, levees, feeding channel. This study shows that high-resolution bathymetry ROV observations are necessary to fully understand the build-up processes of modern channel-mouth lobes.

[Level of microwave radiation from mobile phone base stations built in residential districts].

PubMed

Hu, Ji; Lu, Yiyang; Zhang, Huacheng; Xie, Hebing; Yang, Xinwen

2009-11-01

To investigate the condition of microwave radiation pollution from mobile phone base station built in populated area. Random selected 18 residential districts where had base station and 10 residential districts where had no base stations. A TES-92 electromagnetic radiation monitor were used to measure the intensity of microwave radiation in external and internal living environment. The intensities of microwave radiation in the exposure residential districts were more higher than those of the control residential districts (p < 0.05). There was a intensity peak at about 10 m from the station, it would gradually weaken with the increase of the distance. The level of microwave radiation in antenna main lobe region is not certainly more higher than the side lobe direction, and the side lobe direction also is not more lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place in someplace. The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were more lower than those of outside the aluminum alloys security net (p < 0.05), but the inside or outside of glass-window appears almost no change (p > 0.05). Although all the measure dates on the ground around the base station could be below the primary standard in "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside or inside of a few window was even higher beyond the primary safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.

Evidence for a left-over-right inhibitory mechanism during figural creative thinking in healthy nonartists.

PubMed

Huang, Peiyu; Qiu, Lihua; Shen, Lin; Zhang, Yong; Song, Zhe; Qi, Zhiguo; Gong, Qiyong; Xie, Peng

2013-10-01

As a complex mental process, creativity requires the coordination of multiple brain regions. Previous pathological research on figural creativity has indicated that there is a mechanism by which the left side of the brain inhibits the activities of the right side of the brain during figural creative thinking, but this mechanism has not been directly demonstrated. In this study, we used functional magnetic resonance imaging (fMRI) to demonstrate the existence of this inhibitory mechanism in young adults (15 women, 11 men, mean age: 22 years) that were not artists. By making comparisons between brain activity during creative and uncreative tasks, we found increased activity in the left middle and inferior frontal lobe and strong decreases in activity in the right middle frontal lobe and the left inferior parietal lobe. As such, these data suggest that the left frontal lobe may inhibit the right hemisphere during figural creative thinking in normal people. Moreover, removal of this inhibition by practicing artistry or through specific damage to the left frontal lobe may facilitate the emergence of artistic creativity. Copyright © 2012 Wiley Periodicals, Inc.

Whole-brain MRI phenotyping in dysplasia-related frontal lobe epilepsy.

PubMed

Hong, Seok-Jun; Bernhardt, Boris C; Schrader, Dewi S; Bernasconi, Neda; Bernasconi, Andrea

2016-02-16

To perform whole-brain morphometry in patients with frontal lobe epilepsy and evaluate the utility of group-level patterns for individualized diagnosis and prognosis. We compared MRI-based cortical thickness and folding complexity between 2 frontal lobe epilepsy cohorts with histologically verified focal cortical dysplasia (FCD) (13 type I; 28 type II) and 41 closely matched controls. Pattern learning algorithms evaluated the utility of group-level findings to predict histologic FCD subtype, the side of the seizure focus, and postsurgical seizure outcome in single individuals. Relative to controls, FCD type I displayed multilobar cortical thinning that was most marked in ipsilateral frontal cortices. Conversely, type II showed thickening in temporal and postcentral cortices. Cortical folding also diverged, with increased complexity in prefrontal cortices in type I and decreases in type II. Group-level findings successfully guided automated FCD subtype classification (type I: 100%; type II: 96%), seizure focus lateralization (type I: 92%; type II: 86%), and outcome prediction (type I: 92%; type II: 82%). FCD subtypes relate to diverse whole-brain structural phenotypes. While cortical thickening in type II may indicate delayed pruning, a thin cortex in type I likely results from combined effects of seizure excitotoxicity and the primary malformation. Group-level patterns have a high translational value in guiding individualized diagnostics. © 2016 American Academy of Neurology.

[Predictors of verbal memory decline following temporal lobe surgery].

PubMed

de Vanssay-Maigne, A; Boutin, M; Baudoin-Chial, S

2008-05-01

Verbal memory decline can occur after temporal lobe surgery, especially when the left dominant hemisphere is involved. This potential functional risk must be evaluated before surgery. Among all factors that have been identified by several studies, the side of surgery (left dominant) and high baseline memory performance have been found to be predictive of verbal memory decline. Other factors such as etiology, sex, age at surgery, age at seizure onset, and duration may influence memory decline, but the results are not clear. Our purpose was to identify, in our population of patients and among all risk factors, those that may be predictive of verbal memory decline. Logistic regression was used to examine the effect of each factor on the postoperative verbal memory index (WMS-R) in 101 patients who underwent a right (n=49) or left (n=52) anterior temporal lobe resection. In the group as a whole, 22 % of the patients demonstrated verbal memory decline of more than one standard deviation. The verbal memory decline was significantly related to surgery on the left side and a high level of verbal memory performance. These factors were significant predictors of decline. The other factors (etiology, sex, age at surgery, age at seizure onset, and duration) were not found to be predictive of this decline. Our analysis demonstrates that the patients who are most at risk of undergoing verbal memory deterioration are those who undergo left-sided temporal resection and have good memory scores preoperatively. The contradictions found in the literature about the other factors could be explained by the diversity of the tests and criteria used to assess memory decline.

Antenna analysis using neural networks

NASA Technical Reports Server (NTRS)

Smith, William T.

1992-01-01

Conventional computing schemes have long been used to analyze problems in electromagnetics (EM). The vast majority of EM applications require computationally intensive algorithms involving numerical integration and solutions to large systems of equations. The feasibility of using neural network computing algorithms for antenna analysis is investigated. The ultimate goal is to use a trained neural network algorithm to reduce the computational demands of existing reflector surface error compensation techniques. Neural networks are computational algorithms based on neurobiological systems. Neural nets consist of massively parallel interconnected nonlinear computational elements. They are often employed in pattern recognition and image processing problems. Recently, neural network analysis has been applied in the electromagnetics area for the design of frequency selective surfaces and beam forming networks. The backpropagation training algorithm was employed to simulate classical antenna array synthesis techniques. The Woodward-Lawson (W-L) and Dolph-Chebyshev (D-C) array pattern synthesis techniques were used to train the neural network. The inputs to the network were samples of the desired synthesis pattern. The outputs are the array element excitations required to synthesize the desired pattern. Once trained, the network is used to simulate the W-L or D-C techniques. Various sector patterns and cosecant-type patterns (27 total) generated using W-L synthesis were used to train the network. Desired pattern samples were then fed to the neural network. The outputs of the network were the simulated W-L excitations. A 20 element linear array was used. There were 41 input pattern samples with 40 output excitations (20 real parts, 20 imaginary). A comparison between the simulated and actual W-L techniques is shown for a triangular-shaped pattern. Dolph-Chebyshev is a different class of synthesis technique in that D-C is used for side lobe control as opposed to pattern shaping. The interesting thing about D-C synthesis is that the side lobes have the same amplitude. Five-element arrays were used. Again, 41 pattern samples were used for the input. Nine actual D-C patterns ranging from -10 dB to -30 dB side lobe levels were used to train the network. A comparison between simulated and actual D-C techniques for a pattern with -22 dB side lobe level is shown. The goal for this research was to evaluate the performance of neural network computing with antennas. Future applications will employ the backpropagation training algorithm to drastically reduce the computational complexity involved in performing EM compensation for surface errors in large space reflector antennas.

Antenna analysis using neural networks

NASA Astrophysics Data System (ADS)

Smith, William T.

1992-09-01

Conventional computing schemes have long been used to analyze problems in electromagnetics (EM). The vast majority of EM applications require computationally intensive algorithms involving numerical integration and solutions to large systems of equations. The feasibility of using neural network computing algorithms for antenna analysis is investigated. The ultimate goal is to use a trained neural network algorithm to reduce the computational demands of existing reflector surface error compensation techniques. Neural networks are computational algorithms based on neurobiological systems. Neural nets consist of massively parallel interconnected nonlinear computational elements. They are often employed in pattern recognition and image processing problems. Recently, neural network analysis has been applied in the electromagnetics area for the design of frequency selective surfaces and beam forming networks. The backpropagation training algorithm was employed to simulate classical antenna array synthesis techniques. The Woodward-Lawson (W-L) and Dolph-Chebyshev (D-C) array pattern synthesis techniques were used to train the neural network. The inputs to the network were samples of the desired synthesis pattern. The outputs are the array element excitations required to synthesize the desired pattern. Once trained, the network is used to simulate the W-L or D-C techniques. Various sector patterns and cosecant-type patterns (27 total) generated using W-L synthesis were used to train the network. Desired pattern samples were then fed to the neural network. The outputs of the network were the simulated W-L excitations. A 20 element linear array was used. There were 41 input pattern samples with 40 output excitations (20 real parts, 20 imaginary).

When the Sun Gets in the Way: Stereo Science Observations on the Far Side of the Sun

NASA Astrophysics Data System (ADS)

Vourlidas, A.; Thompson, W. T.; Gurman, J. B.; Luhmann, J. G.; Curtis, D. W.; Schroeder, P. C.; Mewaldt, R. A.; Davis, A. J.; Wortman, K.; Russell, C. T.; Galvin, A. B.; Popecki, M.; Kistler, L. M.; Ellis, L.; Howard, R.; Rich, N.; Hutting, L.; Maksimovic, M.; Bale, S. D.; Goetz, K.

2014-12-01

With the two STEREO spacecraft on the opposite side of the Sun from Earth, pointing the high gain antenna at Earth means that it's also pointed very close to the Sun. This has resulted in unexpectedly high temperatures in the antenna feed horns on both spacecraft, and is forcing the mission operations team to take corrective action, starting in August 2014 for STEREO Ahead, and December 2014 for STEREO Behind. By off-pointing the antennas to use one of the lower power side lobes instead of the main lobe, the feed horn temperatures can be kept at a safe level while still allowing reliable communication with the spacecraft. However, the amount of telemetry that can be brought down will be highly reduced. Even so, significant science will still be possible from STEREO's unique position on the solar far side. We will discuss the science and space weather products that will be available from each STEREO instrument, when those products will be available, and how they will be used. Some data, including the regular space weather beacon products, will be brought down for an average of a few hours each day during the daily real-time passes, while the in situ and radio beacon data will be stored on the onboard recorder to provide a continuous 24-hour coverage for eventual downlink once the spacecraft is back to normal operations.

Propagation of an Airy beam through the atmosphere.

PubMed

Ji, Xiaoling; Eyyuboğlu, Halil T; Ji, Guangming; Jia, Xinhong

2013-01-28

In this paper, the effect of thermal blooming of an Airy beam propagating through the atmosphere is examined, and the effect of atmospheric turbulence is not considered. The changes of the intensity distribution, the centroid position and the mean-squared beam width of an Airy beam propagating through the atmosphere are studied by using the four-dimensional (4D) computer code of the time-dependent propagation of Airy beams through the atmosphere. It is shown that an Airy beam can't retain its shape and the structure when the Airy beam propagates through the atmosphere due to thermal blooming except for the short propagation distance, or the short time, or the low beam power. The thermal blooming results in a central dip of the center lobe, and causes the center lobe to spread and decrease. In contrast with the center lobe, the side lobes are less affected by thermal blooming, such that the intensity maximum of the side lobe may be larger than that of the center lobe. However, the cross wind can reduce the effect of thermal blooming. When there exists the cross wind velocity vx in x direction, the dependence of centroid position in x direction on vx is not monotonic, and there exists a minimum, but the centroid position in y direction is nearly independent of vx.

An improved schlieren method for measurement and automatic reconstruction of the far-field focal spot

PubMed Central

Wang, Zhengzhou; Hu, Bingliang; Yin, Qinye

2017-01-01

The schlieren method of measuring far-field focal spots offers many advantages at the Shenguang III laser facility such as low cost and automatic laser-path collimation. However, current methods of far-field focal spot measurement often suffer from low precision and efficiency when the final focal spot is merged manually, thereby reducing the accuracy of reconstruction. In this paper, we introduce an improved schlieren method to construct the high dynamic-range image of far-field focal spots and improve the reconstruction accuracy and efficiency. First, a detection method based on weak light beam sampling and magnification imaging was designed; images of the main and side lobes of the focused laser irradiance in the far field were obtained using two scientific CCD cameras. Second, using a self-correlation template matching algorithm, a circle the same size as the schlieren ball was dug from the main lobe cutting image and used to change the relative region of the main lobe cutting image within a 100×100 pixel region. The position that had the largest correlation coefficient between the side lobe cutting image and the main lobe cutting image when a circle was dug was identified as the best matching point. Finally, the least squares method was used to fit the center of the side lobe schlieren small ball, and the error was less than 1 pixel. The experimental results show that this method enables the accurate, high-dynamic-range measurement of a far-field focal spot and automatic image reconstruction. Because the best matching point is obtained through image processing rather than traditional reconstruction methods based on manual splicing, this method is less sensitive to the efficiency of focal-spot reconstruction and thus offers better experimental precision. PMID:28207758

A Left-Sided Approach for Resection of Hepatic Caudate Lobe Hemangioma: Two Case Reports and a Literature Review.

PubMed

Feng, Xielin; Hu, Yong; Peng, Junping; Liu, Aixiang; Tian, Lang; Zhang, Hui

2015-06-01

Resection of the hemangioma located in the caudate lobe is a major challenge in current liver surgery. This study aimed to present our surgical technique for this condition. Two consecutive patients with symptomatic hepatic hemangioma undergoing caudate lobectomy were investigated retrospectively. First, all the blood inflow of hemangioma from the portal vein and the hepatic artery at the base of the umbilical fissure was dissected. After the tumors became soft and tender, the short hepatic veins and the ligaments between the secondary porta hepatis were severed. At last the tumors were resected from the right lobe of the liver. The whole process was finished by a left-sided approach. Blood lost in Case 1 was 1650 mL because of ligature failing in one short hepatic vein, and in the other case, 210 mL. Operation time was 236 minutes and 130 minutes, respectively. Postoperative hospital stays were 11 and 5 days, respectively. The diameter of tumors was 9.0 cm and 6.5 cm. Case 1 required blood transfusion during surgery. No complications such as biliary fistula, postoperative bleeding, and liver failure occurred. The left-sided approach produced the best results for caudate lobe resection in our cases. The patients who recovered are living well and asymptomatic. Caudate lobectomy can be performed safely and quickly by a left-sided approach, which is carried out with optimized perioperative management and innovative surgical technique.

Is the lymphatic drainage of lung cancer lobe-specific? A surgical appraisal.

PubMed

Riquet, Marc; Rivera, Caroline; Pricopi, Ciprian; Arame, Alex; Mordant, Pierre; Foucault, Christophe; Dujon, Antoine; Le Pimpec-Barthes, Françoise

2015-03-01

Nowadays, early-stage lung cancers are more frequently encountered. Selective lymph node (LN) dissection based on lobe-specific lymphatic pathway has been proposed. Our aim was to study nodal involvement according to tumour location. We reviewed 1779 lobectomized patients and analysed their pathological characteristics according to tumour location: Group 1 (G1), right upper lobe; Group 2 (G2), right middle lobe; Group 3 (G3), right lower lobe; Group 4 (G4), left upper division; Group 5 (G5), lingula; Group 6 (G6), left lower lobe. The pN status was recorded for each group to analyse the lymphatic spread of non-small-cell lung cancer (NSCLC) according to tumour location. The numbers and proportions of lobectomies in each group were 613 patients in G1 (59.2%), 64 in G2 (6.4%), 359 in G3 (34.6%), 404 in G4 (54.3%), 54 in G5 (7.3%) and 286 in G6 (38.4%). The rates of pN2 involvement were similar, whatever the group was, even when deciphering single- and multistation diseases. on the right side, single-station N2 disease was mainly found in the superior mediastinum (SM) for G1 (95%), and in the inferior for G3 (90%). On the left side, single-station N2 was mainly found in the SM in G4 (94%), and the inferior in G6 (48%). Whatever the side, in case of two-station involvement, both mediastina were concerned in 40% (in G4) to 81% of the case (in G3). Long-term survival rates were different in skip metastasis, single- and multistation involvement, but not between lobes. Tumour location is not a predictor of nodal metastasis pattern. In surgical treatment of NSCLC, complete systematic mediastinal LN dissection remains the only acceptable procedure from an oncological point of view. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Associative episodic memory and recollective processes in childhood temporal lobe epilepsy.

PubMed

Martins, Sylvie; Guillery-Girard, Bérengère; Clochon, Patrice; Bulteau, Christine; Hertz-Pannier, Lucie; Chiron, Catherine; Eustache, Francis; Jambaqué, Isabelle

2015-03-01

While the current literature on children suffering from temporal lobe epilepsy (CTLE) mostly focuses on material-related episodic memory deficits according to seizure-onset lateralization, the present study examined associative episodic memory according to the type of information to memorize (e.g., factual, spatial, and sequential) and further investigated subjective and objective recollection. Eleven children with left temporal lobe epilepsy (LTLE), 10 children with right temporal lobe epilepsy (RTLE), among whom 9 displayed hippocampal sclerosis (HS), and 42 healthy controls completed the WHAT-WHEN-WHERE protocol (Guillery-Girard et al., 2013). Group comparisons were first conducted according to the affected side and second according to the underlying pathology. Results showed associative memory impairments in patients irrespective of the affected side. Moreover, this study revealed that HS is particularly deleterious to associative and subjective recollection in CTLE. In addition, this study emphasizes the need for assessing episodic memory in childhood TLE beyond material specificity. Copyright © 2015 Elsevier Inc. All rights reserved.

Ultrafast Ultrasound Imaging Using Combined Transmissions With Cross-Coherence-Based Reconstruction.

PubMed

Zhang, Yang; Guo, Yuexin; Lee, Wei-Ning

2018-02-01

Plane-wave-based ultrafast imaging has become the prevalent technique for non-conventional ultrasound imaging. The image quality, especially in terms of the suppression of artifacts, is generally compromised by reducing the number of transmissions for a higher frame rate. We hereby propose a new ultrafast imaging framework that reduces not only the side lobe artifacts but also the axial lobe artifacts using combined transmissions with a new coherence-based factor. The results from simulations, in vitro wire phantoms, the ex vivo porcine artery, and the in vivo porcine heart show that our proposed methodology greatly reduced the axial lobe artifact by 25±5 dB compared with coherent plane-wave compounding (CPWC), which was considered as the ultrafast imaging standard, and suppressed side lobe artifacts by 15 ± 5 dB compared with CPWC and coherent spherical-wave compounding. The reduction of artifacts in our proposed ultrafast imaging framework led to a better boundary delineation of soft tissues than CPWC.

Quantitative Evaluation of Medial Temporal Lobe Morphology in Children with Febrile Status Epilepticus: Results of the FEBSTAT Study.

PubMed

McClelland, A C; Gomes, W A; Shinnar, S; Hesdorffer, D C; Bagiella, E; Lewis, D V; Bello, J A; Chan, S; MacFall, J; Chen, M; Pellock, J M; Nordli, D R; Frank, L M; Moshé, S L; Shinnar, R C; Sun, S

2016-12-01

The pathogenesis of febrile status epilepticus is poorly understood, but prior studies have suggested an association with temporal lobe abnormalities, including hippocampal malrotation. We used a quantitative morphometric method to assess the association between temporal lobe morphology and febrile status epilepticus. Brain MR imaging was performed in children presenting with febrile status epilepticus and control subjects as part of the Consequences of Prolonged Febrile Seizures in Childhood study. Medial temporal lobe morphologic parameters were measured manually, including the distance of the hippocampus from the midline, hippocampal height:width ratio, hippocampal angle, collateral sulcus angle, and width of the temporal horn. Temporal lobe morphologic parameters were correlated with the presence of visual hippocampal malrotation; the strongest association was with left temporal horn width (P < .001; adjusted OR, 10.59). Multiple morphologic parameters correlated with febrile status epilepticus, encompassing both the right and left sides. This association was statistically strongest in the right temporal lobe, whereas hippocampal malrotation was almost exclusively left-sided in this cohort. The association between temporal lobe measurements and febrile status epilepticus persisted when the analysis was restricted to cases with visually normal imaging findings without hippocampal malrotation or other visually apparent abnormalities. Several component morphologic features of hippocampal malrotation are independently associated with febrile status epilepticus, even when complete hippocampal malrotation is absent. Unexpectedly, this association predominantly involves the right temporal lobe. These findings suggest that a spectrum of bilateral temporal lobe anomalies are associated with febrile status epilepticus in children. Hippocampal malrotation may represent a visually apparent subset of this spectrum. © 2016 by American Journal of Neuroradiology.

The temporal relation between seizure onset and arousal-awakening in temporal lobe seizures.

PubMed

Gumusyayla, Sadiye; Erdal, Abidin; Tezer, F Irsel; Saygi, Serap

2016-07-01

Our main aim was to determine the time interval between the seizure onsets and arousal-awakening related to these seizures in patients with temporal lobe epilepsy (TLE) and to discuss the role of lateralization on arousal-awakening mechanisms. Thirty-three TLE patients who underwent video-EEG monitoring with simultaneous polysomnography (PSG) and had recorded nocturnal seizures were retrospectively examined. These TLE patients had 64 seizures during sleep. The onsets of seizures and arousal-awakening related to these seizures were marked according to clinical and electrophysiological features. The time interval between the seizure onset and arousal-awakening related to the seizure was compared in patients with right- or left-sided temporal lobe seizures. In our TLE patients nocturnal seizures mostly followed arousal-awakening (64%). The time interval between the seizure onset and arousal-awakening related to the seizure was significantly shorter in patients with left-sided temporal lobe seizures (p=0.01). Video-EEG monitoring and PSG with scalp electrodes in our TLE patients showed that nocturnal seizures mostly followed arousal-awakening, and it was more pronounced in those with left-sided seizures. Arousal-awakening might be a signal for subsequent seizures in patients with TLE. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Performance Evaluation of a Biometric System Based on Acoustic Images

PubMed Central

Izquierdo-Fuente, Alberto; del Val, Lara; Jiménez, María I.; Villacorta, Juan J.

2011-01-01

An acoustic electronic scanning array for acquiring images from a person using a biometric application is developed. Based on pulse-echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side). Two Uniform Linear Arrays (ULA) with 15 λ/2-equispaced sensors have been employed, using different spatial apertures in order to reduce sidelobe levels. Working frequencies have been designed on the basis of the main lobe width, the grating lobe levels and the frequency responses of people and sensors. For a case-study with 10 people, the acoustic profiles, formed by all images acquired, are evaluated and compared in a mean square error sense. Finally, system performance, using False Match Rate (FMR)/False Non-Match Rate (FNMR) parameters and the Receiver Operating Characteristic (ROC) curve, is evaluated. On the basis of the obtained results, this system could be used for biometric applications. PMID:22163708

Frontal lobe epileptic seizures are accompanied by elevated pitch during verbal communication.

PubMed

Speck, Iva; Echternach, Matthias; Sammler, Daniela; Schulze-Bonhage, Andreas

2018-03-01

The objective of our study was to assess alterations in speech as a possible localizing sign in frontal lobe epilepsy. Ictal speech was analyzed in 18 patients with frontal lobe epilepsy (FLE) during seizures and in the interictal period. Matched identical words were analyzed regarding alterations in fundamental frequency (ƒo) as an approximation of pitch. In patients with FLE, ƒo of ictal utterances was significantly higher than ƒo in interictal recordings (p = 0.016). Ictal ƒo increases occurred in both FLE of right and left seizure origin. In contrast, a matched temporal lobe epilepsy (TLE) group showed less pronounced increases in ƒo, and only in patients with right-sided seizure foci. This study for the first time shows significant voice alterations in ictal speech in a cohort of patients with FLE. This may contribute to the localization of the epileptic focus. Increases in ƒo were interestingly found in frontal lobe seizures with origin in either hemisphere, suggesting a bilateral involvement to the planning of speech production, in contrast to a more right-sided lateralization of pitch perception in prosodic processing. Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.

Alteration of Duration Mismatch Negativity Induced by Transcranial Magnetic Stimulation Over the Left Parietal Lobe.

PubMed

Oshima, Hirokazu; Shiga, Tetsuya; Niwa, Shin-Ichi; Enomoto, Hiroyuki; Ugawa, Yoshikazu; Yabe, Hirooki

2017-01-01

Mismatch negativity (MMN) is generated by a comparison between an incoming sound and the memory trace of preceding sounds stored in sensory memory without any attention to the sound. N100 (N1) is associated with the afferent response to sound onset and reflects early analysis of stimulus characteristics. MMN generators are present in the temporal and frontal lobe, and N1 generators are present in the temporal lobe. The parietal lobe is involved in MMN generation elicited by a change in duration. The anatomical network connecting these areas, lateralization, and the effect of the side of ear stimulation on MMN remain unknown. Thus, we studied the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the left parietal lobe on MMN and N1 in 10 healthy subjects. Low-frequency rTMS over the left parietal lobe decreased the amplitude of MMN following right ear sound stimulation, but the amplitude was unaffected with left ear sound stimulation. We observed no significant changes in the amplitude of N1 or the latency of MMN or N1. These results suggest that low-frequency rTMS over the left parietal lobe modulates the detection of early auditory changes in duration in healthy subjects. Stimulation that is contralateral to the side of the ear experiencing sound may affect the generation of duration MMN more than ipsilateral stimulation. © EEG and Clinical Neuroscience Society (ECNS) 2016.

A componential analysis of proverb interpretation in patients with frontal lobe epilepsy and temporal lobe epilepsy: relationships with disease-related factors.

PubMed

McDonald, Carrie R; Delis, Dean C; Kramer, Joel H; Tecoma, Evelyn S; Iragui, Vicente J

2008-05-01

The ability to interpret nonliteral, metaphoric language was explored in patients with frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE), and matched control participants, to determine (1) if patients with FLE were impaired in their interpretations relative to those with TLE and controls, and (2) if disease-related variables (e.g., age of seizure onset) predicted performances in either patient group. A total of 22 patients with FLE, 20 patients with TLE, and 23 controls were administered a test of proverb interpretation to assess their ability to grasp the abstract meaning of nonliteral language. Participants were presented with a series of proverbs and asked to provide an oral interpretation of each. Responses to each proverb were scored according to their accuracy and level of abstractness. Patients with FLE, but not TLE, were impaired relative to controls in their overall interpretation of proverbs. However, a subgroup analysis revealed that only patients with left FLE showed impaired interpretation accuracy relative to the other groups, whereas patients with both left FLE and left TLE showed impaired abstraction. Patients with FLE were also impaired when they were asked to select the best interpretation of the proverb from response alternatives. In patients with FLE, only a left-sided seizure focus was associated with poorer performance. In patients with TLE, both an early age of onset and a left-sided seizure focus predicted poorer performance. Overall, FLE patients exhibit greater impairment than TLE patients in interpreting proverbs. However, the nature and disease-specific correlates of impaired performances in proverb interpretation differ between the groups.

A COMPONENTIAL ANALYSIS OF PROVERB INTERPRETATION IN PATIENTS WITH FRONTAL LOBE EPILEPSY AND TEMPORAL LOBE EPILEPSY: RELATIONSHIPS WITH DISEASE-RELATED FACTORS

PubMed Central

McDonald, Carrie R.; Delis, Dean C.; Kramer, Joel H.; Tecoma, Evelyn S.; Iragui, Vicente J.

2017-01-01

The ability to interpret nonliteral, metaphoric language was explored in patients with frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE), and matched control participants, to determine (1) if patients with FLE were impaired in their interpretations relative to those with TLE and controls, and (2) if disease-related variables (e.g., age of seizure onset) predicted performances in either patient group. A total of 22 patients with FLE, 20 patients with TLE, and 23 controls were administered a test of proverb interpretation to assess their ability to grasp the abstract meaning of nonliteral language. Participants were presented with a series of proverbs and asked to provide an oral interpretation of each. Responses to each proverb were scored according to their accuracy and level of abstractness. Patients with FLE, but not TLE, were impaired relative to controls in their overall interpretation of proverbs. However, a subgroup analysis revealed that only patients with left FLE showed impaired interpretation accuracy relative to the other groups, whereas patients with both left FLE and left TLE showed impaired abstraction. Patients with FLE were also impaired when they were asked to select the best interpretation of the proverb from response alternatives. In patients with FLE, only a left-sided seizure focus was associated with poorer performance. In patients with TLE, both an early age of onset and a left-sided seizure focus predicted poorer performance. Overall, FLE patients exhibit greater impairment than TLE patients in interpreting proverbs. However, the nature and disease-specific correlates of impaired performances in proverb interpretation differ between the groups. PMID:17853125

Thyroid gland rupture caused by blunt trauma to the neck.

PubMed

Hara, Hirotaka; Hirose, Yoshinobu; Yamashita, Hiroshi

2016-02-19

Thyroid rupture following blunt trauma is extremely rare, and neck pain without swelling may be the only presenting symptom. However, hemorrhage and hematoma subsequently causes severe tracheal compression and respiratory distress. A 71-year-old Japanese woman visited our emergency room with a complaint of increasing right-sided neck pain at the thyroid cartilage level after she tripped and accidentally hit her neck against a pole 3 h back. On admission, her vital signs were stable. There was no swelling or subcutaneous emphysema. Laryngeal endoscopy revealed mild laryngeal edema, although there was no impairment in vocal fold mobility on either side. Contrast-enhanced computed tomography (CT) revealed rupture of the right lobe of the thyroid gland accompanied by a large hematoma extending from the neck to the mediastinum. Under general anesthesia, the right lobe was resected and the hematoma was evacuated. Only a few isolated cases of thyroid rupture caused by blunt neck trauma have been reported in patients with normal thyroid glands and neck pain without swelling may be the only presenting symptom. When suspected, CT should be performed to confirm the diagnosis determine the optimal treatment.

Improvement of resolution in full-view linear-array photoacoustic computed tomography using a novel adaptive weighting method

NASA Astrophysics Data System (ADS)

Omidi, Parsa; Diop, Mamadou; Carson, Jeffrey; Nasiriavanaki, Mohammadreza

2017-03-01

Linear-array-based photoacoustic computed tomography is a popular methodology for deep and high resolution imaging. However, issues such as phase aberration, side-lobe effects, and propagation limitations deteriorate the resolution. The effect of phase aberration due to acoustic attenuation and constant assumption of the speed of sound (SoS) can be reduced by applying an adaptive weighting method such as the coherence factor (CF). Utilizing an adaptive beamforming algorithm such as the minimum variance (MV) can improve the resolution at the focal point by eliminating the side-lobes. Moreover, invisibility of directional objects emitting parallel to the detection plane, such as vessels and other absorbing structures stretched in the direction perpendicular to the detection plane can degrade resolution. In this study, we propose a full-view array level weighting algorithm in which different weighs are assigned to different positions of the linear array based on an orientation algorithm which uses the histogram of oriented gradient (HOG). Simulation results obtained from a synthetic phantom show the superior performance of the proposed method over the existing reconstruction methods.

Working memory network plasticity after anterior temporal lobe resection: a longitudinal functional magnetic resonance imaging study

PubMed Central

Stretton, Jason; Sidhu, Meneka K.; Winston, Gavin P.; Bartlett, Philippa; McEvoy, Andrew W.; Symms, Mark R.; Koepp, Matthias J.; Thompson, Pamela J.

2014-01-01

Working memory is a crucial cognitive function that is disrupted in temporal lobe epilepsy. It is unclear whether this impairment is a consequence of temporal lobe involvement in working memory processes or due to seizure spread to extratemporal eloquent cortex. Anterior temporal lobe resection controls seizures in 50–80% of patients with drug-resistant temporal lobe epilepsy and the effect of surgery on working memory are poorly understood both at a behavioural and neural level. We investigated the impact of temporal lobe resection on the efficiency and functional anatomy of working memory networks. We studied 33 patients with unilateral medial temporal lobe epilepsy (16 left) before, 3 and 12 months after anterior temporal lobe resection. Fifteen healthy control subjects were also assessed in parallel. All subjects had neuropsychological testing and performed a visuospatial working memory functional magnetic resonance imaging paradigm on these three separate occasions. Changes in activation and deactivation patterns were modelled individually and compared between groups. Changes in task performance were included as regressors of interest to assess the efficiency of changes in the networks. Left and right temporal lobe epilepsy patients were impaired on preoperative measures of working memory compared to controls. Working memory performance did not decline following left or right temporal lobe resection, but improved at 3 and 12 months following left and, to a lesser extent, following right anterior temporal lobe resection. After left anterior temporal lobe resection, improved performance correlated with greater deactivation of the left hippocampal remnant and the contralateral right hippocampus. There was a failure of increased deactivation of the left hippocampal remnant at 3 months after left temporal lobe resection compared to control subjects, which had normalized 12 months after surgery. Following right anterior temporal lobe resection there was a progressive increase of activation in the right superior parietal lobe at 3 and 12 months after surgery. There was greater deactivation of the right hippocampal remnant compared to controls between 3 and 12 months after right anterior temporal lobe resection that was associated with lesser improvement in task performance. Working memory improved after anterior temporal lobe resection, particularly following left-sided resections. Postoperative working memory was reliant on the functional capacity of the hippocampal remnant and, following left resections, the functional reserve of the right hippocampus. These data suggest that working memory following temporal lobe resection is dependent on the engagement of the posterior medial temporal lobes and eloquent cortex. PMID:24691395

Diffusion tensor tractography detection of functional pathway for the spread of epileptiform activity between temporal lobe and Rolandic region.

PubMed

Bhardwaj, Ratan D; Mahmoodabadi, Sina Zarei; Otsubo, Hiroshi; Snead, O Carter; Rutka, James T; Widjaja, Elysa

2010-02-01

The aim of the study was to assess the connectivity between magnetoencephalographic (MEG) dipoles in the temporal lobe and Rolandic region in children with temporal lobe epilepsy using diffusion tensor imaging (DTI) tractography. Six pediatric patients with intractable focal epilepsy had MEG performed, which showed MEG dipoles over both temporal and Rolandic regions in a unilateral hemisphere. DTI tractography was performed on each patient. Six control subjects were studied for comparison. Two volumes of interest (VOIs) that encompassed the MEG dipoles were drawn, one placed in temporal lobe and the other in Rolandic region. Similar VOIs were placed in the contralateral side in the patients and on both sides in controls. Fractional anisotropy (FA) and trace of the external capsules were compared between patients and controls. In all patients, a tractography pathway traversing through the external capsule, connecting the temporal and Rolandic MEG dipoles, was visualized. However, on the contralateral hemisphere in each patient, there was no evidence of a similar fiber tract. There was no corresponding tractography pathway identified in either hemisphere within the controls. There were no significant differences in FA and trace between the seizure focus side and contralateral side in the patients. There was no significant difference in FA, but a difference in trace between patients and controls. We have found aberrant tractography pathway traversing through the external capsule, connecting two distant foci of epileptiform activity. Chronic interictal epileptogenic discharge could play a causal role in the de novo organization of these tracts.

SIRE: a MIMO radar for landmine/IED detection

NASA Astrophysics Data System (ADS)

Ojowu, Ode; Wu, Yue; Li, Jian; Nguyen, Lam

2013-05-01

Multiple-input multiple-output (MIMO) radar systems have been shown to have significant performance improvements over their single-input multiple-output (SIMO) counterparts. For transmit and receive elements that are collocated, the waveform diversity afforded by this radar is exploited for performance improvements. These improvements include but are not limited to improved target detection, improved parameter identifiability and better resolvability. In this paper, we present the Synchronous Impulse Reconstruction Radar (SIRE) Ultra-wideband (UWB) radar designed by the Army Research Lab (ARL) for landmine and improvised explosive device (IED) detection as a 2 by 16 MIMO radar (with collocated antennas). Its improvement over its SIMO counterpart in terms of beampattern/cross range resolution are discussed and demonstrated using simulated data herein. The limitations of this radar for Radio Frequency Interference (RFI) suppression are also discussed in this paper. A relaxation method (RELAX) combined with averaging of multiple realizations of the measured data is presented for RFI suppression; results show no noticeable target signature distortion after suppression. In this paper, the back-projection (delay and sum) data independent method is used for generating SAR images. A side-lobe minimization technique called recursive side-lobe minimization (RSM) is also discussed for reducing side-lobes in this data independent approach. We introduce a data-dependent sparsity based spectral estimation technique called Sparse Learning via Iterative Minimization (SLIM) as well as a data-dependent CLEAN approach for generating SAR images for the SIRE radar. These data-adaptive techniques show improvement in side-lobe reduction and resolution for simulated data for the SIRE radar.

Prediction of seizure-onset laterality by using Wada memory asymmetries in pediatric epilepsy surgery candidates.

PubMed

Lee, Gregory P; Park, Yong D; Hempel, Ann; Westerveld, Michael; Loring, David W

2002-09-01

Because the capacity of intracarotid amobarbital (Wada) memory assessment to predict seizure-onset laterality in children has not been thoroughly investigated, three comprehensive epilepsy surgery centers pooled their data and examined Wada memory asymmetries to predict side of seizure onset in children being considered for epilepsy surgery. One hundred fifty-two children with intractable epilepsy underwent Wada testing. Although the type and number of memory stimuli and methods varied at each institution, all children were presented with six to 10 items soon after amobarbital injection. After return to neurologic baseline, recognition memory for the stimuli was assessed. Seizure onset was determined by simultaneous video-EEG recordings of multiple seizures. In children with unilateral temporal lobe seizures (n = 87), Wada memory asymmetries accurately predicted seizure laterality to a statistically significant degree. Wada memory asymmetries also correctly predicted side of seizure onset in children with extra-temporal lobe seizures (n = 65). Although individual patient prediction accuracy was statistically significant in temporal lobe cases, onset laterality was incorrectly predicted in < or =52% of children with left temporal lobe seizure onset, depending on the methods and asymmetry criterion used. There also were significant differences between Wada prediction accuracy across the three epilepsy centers. Results suggest that Wada memory assessment is useful in predicting side of seizure onset in many children. However, Wada memory asymmetries should be interpreted more cautiously in children than in adults.

Complete prefrontal lobe isolation surgery for recurrent epilepsy: A case report

PubMed Central

Yin, Shaoya; Jin, Weipeng; Li, Qingyun; Feng, Mei; Feng, Keke; Shao, Hui; Zhang, Xueqing; Wang, Shimin

2016-01-01

Epileptogenic focus resection is less effective for the treatment of frontal lobe epilepsy compared with temporal lobe epilepsy. However, there is currently a lack of effective therapeutic options for patients with frontal lobe epilepsy who are unsuitable for epileptogenic focus resection (such patients with epileptogenic foci in one frontal lobe in which the precise epileptic foci cannot be determined), or who experience recurrent epilepsy following epileptogenic focus resection. The present study reports a patient with frontal lobe epilepsy who underwent successful frontal lobe isolation surgery following a previous unsuccessful epileptogenic focus resection surgery. To ensure complete isolation of the prefrontal lobe, the surgery included division of the anterior commissure and the anterior part of the corpus callosum. The patient was followed-up for 16 months. Although the follow-up electroencephalogram presented a number of sharp waves on the affected side, the patient did not experience any seizures. The results suggest that prefrontal lobe isolation is an effective method of treating frontal lobe epilepsy, as division of the anterior commissure and the anterior part of the corpus callosum ensures disconnection of the prefrontal lobe from other regions of the brain. PMID:27882111

An Improved Adaptive Received Beamforming for Nested Frequency Offset and Nested Array FDA-MIMO Radar.

PubMed

Cheng, Sibei; Zhang, Qingjun; Bian, Mingming; Hao, Xinhong

2018-02-08

For the conventional FDA-MIMO (frequency diversity array multiple-input-multiple-output) Radar with uniform frequency offset and uniform linear array, the DOFs (degrees of freedom) of the adaptive beamformer are limited by the number of elements. A better performance-for example, a better suppression for strong interferences and a more desirable trade-off between the main lobe and side lobe-can be achieved with a greater number of DOFs. In order to obtain larger DOFs, this paper researches the signal model of the FDA-MIMO Radar with nested frequency offset and nested array, then proposes an improved adaptive beamforming method that uses the augmented matrix instead of the covariance matrix to calculate the optimum weight vectors and can be used to improve the output performances of FDA-MIMO Radar with the same element number or reduce the element number while maintain the approximate output performances such as the received beampattern, the main lobe width, side lobe depths and the output SINR (signal-to-interference-noise ratio). The effectiveness of the proposed scheme is verified by simulations.

Theoretical Radiation Patterns of NAVSPASUR Transmitter Antennas

DTIC Science & Technology

1988-11-30

NAVSPASUR handbooks[7,8]. Our calculated north-south 3 dB far-field beamwidth of 0.0210 agrees with the reported value, as does the first sidelobe level ...in Fig. 18, has far-field 3 dB beamwidth and first side lobe levels which agree with the reported values 0.220 and -13 dB, respectively. 3 Again, the...L. Berg .::, UT1 rAT pu;blic release 3 Novemer 198e I 30 November 1988 I I I = i i I I I29I /I I I EXECUTIVE SUMMARY I Interferometrics Inc. has

Emplacement of subaerial pahoehoe lava sheet flows into water: 1990 Kūpaianaha flow of Kilauea volcano at Kaimū Bay, Hawai`i

USGS Publications Warehouse

Umino, Susumu; Nonaka, Miyuki; Kauahikaua, James P.

2006-01-01

Episode 48 of the ongoing eruption of Kilauea, Hawai`i, began in July 1986 and continuously extruded lava for the next 5.5 years from a low shield, Kūpaianaha. The flows in March 1990 headed for Kalapana and inundated the entire town under 15–25 m of lava by the end of August. As the flows advanced eastward, they entered into Kaimū Bay, replacing it with a plain of lava that extends 300 m beyond the original shoreline. The focus of our study is the period from August 1 to October 31, 1990, when the lava buried almost 406,820 m2 of the 5-m deep bay. When lava encountered the sea, it flowed along the shoreline as a narrow primary lobe up to 400 m long and 100 m wide, which in turn inflated to a thickness of 5–6 m. The flow direction of the primary lobes was controlled by the submerged delta below the lavas and by damming up lavas fed at low extrusion rates. Breakout flows through circumferential and axial inflation cracks on the inflating primary lobes formed smaller secondary lobes, burying the lows between the primary lobes and hiding their original outlines. Inflated flow lobes eventually ruptured at proximal and/or distal ends as well as mid-points between the two ends, feeding new primary lobes which were emplaced along and on the shore side of the previously inflated lobes. The flow lobes mapped with the aid of aerial photographs were correlated with daily observations of the growing flow field, and 30 primary flow lobes were dated. Excluding the two repose periods that intervened while the bay was filled, enlargement of the flow field took place at a rate of 2,440–22,640 square meters per day in the bay. Lobe thickness was estimated to be up to 11 m on the basis of cross sections of selected lobes measured using optical measurement tools, measuring tape and hand level. The total flow-lobe volume added in the bay during August 1–October 31 was approximately 3.95 million m3, giving an average supply rate of 0.86 m3/s.

Emplacement of subaerial pahoehoe lava sheet flows into water: 1990 Kūpaianaha flow of Kilauea volcano at Kaimū Bay, Hawai`i

NASA Astrophysics Data System (ADS)

Umino, Susumu; Nonaka, Miyuki; Kauahikaua, Jim

2006-09-01

Episode 48 of the ongoing eruption of Kilauea, Hawai`i, began in July 1986 and continuously extruded lava for the next 5.5 years from a low shield, Kūpaianaha. The flows in March 1990 headed for Kalapana and inundated the entire town under 15-25 m of lava by the end of August. As the flows advanced eastward, they entered into Kaimū Bay, replacing it with a plain of lava that extends 300 m beyond the original shoreline. The focus of our study is the period from August 1 to October 31, 1990, when the lava buried almost 406,820 m2 of the 5-m deep bay. When lava encountered the sea, it flowed along the shoreline as a narrow primary lobe up to 400 m long and 100 m wide, which in turn inflated to a thickness of 5-6 m. The flow direction of the primary lobes was controlled by the submerged delta below the lavas and by damming up lavas fed at low extrusion rates. Breakout flows through circumferential and axial inflation cracks on the inflating primary lobes formed smaller secondary lobes, burying the lows between the primary lobes and hiding their original outlines. Inflated flow lobes eventually ruptured at proximal and/or distal ends as well as mid-points between the two ends, feeding new primary lobes which were emplaced along and on the shore side of the previously inflated lobes. The flow lobes mapped with the aid of aerial photographs were correlated with daily observations of the growing flow field, and 30 primary flow lobes were dated. Excluding the two repose periods that intervened while the bay was filled, enlargement of the flow field took place at a rate of 2,440-22,640 square meters per day in the bay. Lobe thickness was estimated to be up to 11 m on the basis of cross sections of selected lobes measured using optical measurement tools, measuring tape and hand level. The total flow-lobe volume added in the bay during August 1-October 31 was approximately 3.95 million m3, giving an average supply rate of 0.86 m3/s.

Hot-flow tests of a series of 10-percent-scale turbofan forced mixing nozzles

NASA Technical Reports Server (NTRS)

Head, V. L.; Povinelli, L. A.; Gerstenmaier, W. H.

1984-01-01

An approximately 1/10-scale model of a mixed-flow exhaust system was tested in a static facility with fully simulated hot-flow cruise and takeoff conditions. Nine mixer geometries with 12 to 24 lobes were tested. The areas of the core and fan stream were held constant to maintain a bypass ratio of approximately 5. The research results presented in this report were obtained as part of a program directed toward developing an improved mixer design methodology by using a combined analytical and experimental approach. The effects of lobe spacing, lobe penetration, lobe-to-centerbody gap, lobe contour, and scalloping of the radial side walls were investigated. Test measurements included total pressure and temperature surveys, flow angularity surveys, and wall and centerbody surface static pressure measurements. Contour plots at various stations in the mixing region are presented to show the mixing effectiveness for the various lobe geometries.

[INCIDENCE AND SURGICAL IMPORTANCE OF PYRAMIDAL LOBE AND TUBERCLE OF THE THYROID GLAND: A PROSPECTIVE STUDY].

PubMed

Kovacić, Marijan; Kovadcić, Ivan

2015-01-01

The pyramidal lobe and tubercles are common anatomic variations of the thyroid gland, and their frequency is highly represented. While pyramidal lobe requires additional seriousness in identifying and its removal, especially in patients with hyperthyroidism and thyroid cancer, the presence of tubercles is desirable. Tubercle is covered by recurrent laryngeal nerve and directs the surgeon in his search and besides this, serves to facilitate detection of the upper parathyroid glands. In this prospective study we analysed 342 patients who underwent total thyroidectomy in the period from January 2009 to March 2015. We looked at the incidence and anatomic characteristics of pyramidal lobe and tubercles of the thyroid gland. The pyramidal lobe was present in 52.3% of the patients with more frequent central and left placement. Bilateral tubercles were present in 14.9%, while position right-sided phenomenon was represented in 39.5% and 18.5% in lower left (64.3% patients). Their prevalence by gender showed no significant difference (p = 0.59; p = 0.2). Associated presence of pyramidal lobe and tubercles on one or both sides is highly represented in our group of patients (34%), also with no differences by gender (p = 0.29). Length of the pyramidal lobe ranged from 1.3 to 4.7 cm (average 2.3 cm), and the size of tubercles in 36% of patients was over 1 cm. Recurrent laryngeal nerve was only in 1.8% placed laterally of tubercles, and the upper parathyroid gland in 95.4% was located above tubercle. Considering that only 16.5% of our patients did not have any of these anatomical variations, their presence during surgery is the rule, not the exception.

Temporal evolution of hepatic anatomy during gestation and growth in the sheep.

PubMed

Douart, C; Briand, L; Betti, E; Bencharif, D; Tainturier, D

2015-02-01

In mammals, the liver undergoes a series of spectacular anatomical changes during development, particularly in domestic ruminants. In all domestic mammals, the liver retracts cranially until it reaches its definitive diaphragmatic position; however, in the sheep, it also withdraws from the entire left side of the diaphragm and seems to rotate through 180°. An anatomical study reveals that the hepatic conformation evolves very little during this topographical change. The latter occurs in two phases: an initial phase of marked regression of the left lobe, which starts from the beginning of the foetal period (44th day of gestation), followed by marked regression of the entire liver, which starts between the 90th and 117th days and ends between the 2nd and 3rd month of life. The path of hepatic regression is dictated by the particular layout of the liver's attachments in the sheep. The left triangular ligament, which holds the L lobe to the left in other species, is almost completely absent in the sheep, whilst the right lobe is fixed to the top of the diaphragm. As the liver regresses, the right lobe therefore draws the left lobe with it to the right-hand side. A statistical study shows constant regression of the hepatic surface area during the topographical evolution of the liver, with a particularly marked and sudden reduction between the end of the 4th month and the middle of the 5th month of gestation. It also shows that the regression of the left lobe is consistently greater than that of the right lobe and that the topographical regression of the liver cannot be predicted by measuring the weight of the liver, which behaves independently to the surface area of the liver. © 2014 Blackwell Verlag GmbH.

Congenital lobar emphysema: a case report

PubMed Central

2009-01-01

Congenital lobar emphysema is a rare variety of congenital malformation of lung characterized by over distension of a lobe of a lung due to partial obstruction of the bronchus. We are reporting a neonate admitted in the pediatric emergency ward with the respiratory distress since 16th day of life. Investigation revealed the overexpansion of the left upper lobe with mediastinal herniation, shifting of the mediastinum to the opposite side and collapse of the ipsilateral lower lobe. The baby was treated with conservative treatment and the condition of the baby was improved. PMID:19154591

Modified Liver Hanging Maneuver for En-bloc Right-sided Hepatectomy Combined with Total Caudate Lobectomy for Colon-Cancer Liver Metastasis and Hepatocellular Carcinoma.

PubMed

Hiroshima, Yukihiko; Matsuo, Kenichi; Kawaguchi, Daisuke; Kikuchi, Yutaro; Endo, Itaru; Koda, Keiji; Togo, Shinji; Hoffman, Robert M; Tanaka, Kuniya

2016-04-01

A right-sided hepatectomy with total caudate lobectomy is indicated for colorectal-cancer liver metastases (CLM) and hepatocellular carcinomas (HCC) located in the caudate lobe with extension to the right lobe of the liver. Caudate-lobe resection (i.e. segmentectomy 1 according to the Brisbane terminology) is one of the most difficult types of hepatectomy to carry out radically and safely. The deep portion of hepatic transection around the caudate lobe, hepatic veins and inferior vena cava is a critical source of massive bleeding. Prolonged transection can increase blood loss. We analyzed the outcome of 10 patients who underwent right-sided hepatectomy with caudate lobectomy using a modified liver hanging maneuver (mLHM) in comparison with 16 patients who underwent the operation without mLHM. Blood loss during liver transection and blood loss per unit area of cut surface were significantly less in the mLHM group (p=0.014 and 0.015, respectively). In patients diagnosed pathologically with liver impairment, transection time was significantly shorter in the mLHM group (p=0.038), as were red blood cell transfusion volume (p=0.042) and blood loss (p=0.049) during transection. Use of mLHM can potentially improve surgical outcomes by reducing blood loss and transection time, which are especially important for patients with liver impairment. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Outcome of temporal lobe epilepsy surgery predicted by statistical parametric PET imaging.

PubMed

Wong, C Y; Geller, E B; Chen, E Q; MacIntyre, W J; Morris, H H; Raja, S; Saha, G B; Lüders, H O; Cook, S A; Go, R T

1996-07-01

PET is useful in the presurgical evaluation of temporal lobe epilepsy. The purpose of this retrospective study is to assess the clinical use of statistical parametric imaging in predicting surgical outcome. Interictal 18FDG-PET scans in 17 patients with surgically-treated temporal lobe epilepsy (Group A-13 seizure-free, group B = 4 not seizure-free at 6 mo) were transformed into statistical parametric imaging, with each pixel representing a z-score value by using the mean and s.d. of count distribution in each individual patient, for both visual and quantitative analysis. Mean z-scores were significantly more negative in anterolateral (AL) and mesial (M) regions on the operated side than the nonoperated side in group A (AL: p < 0.00005, M: p = 0.0097), but not in group B (AL: p = 0.46, M: p = 0.08). Statistical parametric imaging correctly lateralized 16 out of 17 patients. Only the AL region, however, was significant in predicting surgical outcome (F = 29.03, p < 0.00005). Using a cut-off z-score value of -1.5, statistical parametric imaging correctly classified 92% of temporal lobes from group A and 88% of those from Group B. The preliminary results indicate that statistical parametric imaging provides both clinically useful information for lateralization in temporal lobe epilepsy and a reliable predictive indicator of clinical outcome following surgical treatment.

Broadband implementation of coprime linear microphone arrays for direction of arrival estimation.

PubMed

Bush, Dane; Xiang, Ning

2015-07-01

Coprime arrays represent a form of sparse sensing which can achieve narrow beams using relatively few elements, exceeding the spatial Nyquist sampling limit. The purpose of this paper is to expand on and experimentally validate coprime array theory in an acoustic implementation. Two nested sparse uniform linear subarrays with coprime number of elements ( M and N) each produce grating lobes that overlap with one another completely in just one direction. When the subarray outputs are combined it is possible to retain the shared beam while mostly canceling the other superfluous grating lobes. In this way a small number of microphones ( N+M-1) creates a narrow beam at higher frequencies, comparable to a densely populated uniform linear array of MN microphones. In this work beampatterns are simulated for a range of single frequencies, as well as bands of frequencies. Narrowband experimental beampatterns are shown to correspond with simulated results even at frequencies other than the arrays design frequency. Narrowband side lobe locations are shown to correspond to the theoretical values. Side lobes in the directional pattern are mitigated by increasing bandwidth of analyzed signals. Direction of arrival estimation is also implemented for two simultaneous noise sources in a free field condition.

Mesial temporal lobe morphology in intractable pediatric epilepsy: so-called hippocampal malrotation, associated findings, and relevance to presurgical assessment.

PubMed

Leach, James L; Awwad, Reem; Greiner, Hansel M; Vannest, Jennifer J; Miles, Lili; Mangano, Francesco T

2016-06-01

OBJECTIVE Diagnostic criteria for hippocampal malrotation (HIMAL) on brain MRI typically include a rounded hippocampus, vertical collateral sulcus, and architectural blurring. Relationship to epileptogenesis remains speculative, and usefulness for surgical guidance is unknown. The study was performed to determine the prevalence of hippocampal rotational anomalies in a cohort of pediatric patients with intractable epilepsy undergoing evaluation for surgery and to determine the significance of this finding in the context of surgical planning. METHODS Forty-eight surgically treated children with intractable epilepsy were compared with matched healthy subjects; reviewers were blinded to surgical side. Each temporal lobe was evaluated for rounded hippocampus, blurring, vertical collateral sulcus, wide choroidal fissure, enlarged temporal horn, low fornix, hippocampal signal, and findings of hippocampal sclerosis. A mesial temporal lobe (MTL) score was calculated by summing the number of features, and the collateral sulcus angle (CSA) was measured in each temporal lobe. Surgical side, pathological diagnosis, and imaging findings elsewhere in the brain were tabulated. Presence of HIMAL, associated imaging features, and MTL score were compared between sides, between epilepsy and control groups, in relationship to side of surgery, and in relationship to postoperative outcome. RESULTS Only 3 epilepsy patients (6.2%) and no controls exhibited all 3 features of HIMAL (p = 0.12). Eight of 48 (16.7%) epilepsy versus 2 of 48 (4.6%) control subjects had both a rounded hippocampus and vertical collateral sulcus (suggesting HIMAL) (p = 0.045). In control and epilepsy subjects, most findings were more prevalent on the left, and the left CSA was more vertical (p < 0.0001). Epilepsy subjects had higher MTL scores (z = -2.95, p = 0.002) and more acute CSAs (p = 0.04) than controls. Only lateralizing raw MTL score had a significant association with surgical side (p = 0.03, OR 7.33); however, this was not significant when hippocampal sclerosis cases were excluded. HIMAL findings were more prevalent and MTL scores were higher in patients with resections involving the temporal lobes. On group analysis, HIMAL findings did not predict eventual surgical side and did not predict outcome, although the numbers are small. In 4 patients the abnormally rotated hippocampus was resected and showed hippocampal sclerosis and/or dysplastic changes on histopathology. All of these patients had a good outcome after surgery. CONCLUSIONS While increased in prevalence in children with intractable epilepsy, imaging findings of HIMAL did not have preoperative lateralizing utility in this group. Findings of HIMAL (including round hippocampus, architectural blurring, and vertical collateral sulcus) did not predict outcome after surgery, although the small number of patients with these findings limits evaluation. In the small number of patients in which the malrotated hippocampus was removed, outcome was good. Further research is needed to continue to define this association in children with intractable epilepsy, focusing on a temporal lobe cohort.

Clinical value of CT-based preoperative software assisted lung lobe volumetry for predicting postoperative pulmonary function after lung surgery

NASA Astrophysics Data System (ADS)

Wormanns, Dag; Beyer, Florian; Hoffknecht, Petra; Dicken, Volker; Kuhnigk, Jan-Martin; Lange, Tobias; Thomas, Michael; Heindel, Walter

2005-04-01

This study was aimed to evaluate a morphology-based approach for prediction of postoperative forced expiratory volume in one second (FEV1) after lung resection from preoperative CT scans. Fifteen Patients with surgically treated (lobectomy or pneumonectomy) bronchogenic carcinoma were enrolled in the study. A preoperative chest CT and pulmonary function tests before and after surgery were performed. CT scans were analyzed by prototype software: automated segmentation and volumetry of lung lobes was performed with minimal user interaction. Determined volumes of different lung lobes were used to predict postoperative FEV1 as percentage of the preoperative values. Predicted FEV1 values were compared to the observed postoperative values as standard of reference. Patients underwent lobectomy in twelve cases (6 upper lobes; 1 middle lobe; 5 lower lobes; 6 right side; 6 left side) and pneumonectomy in three cases. Automated calculation of predicted postoperative lung function was successful in all cases. Predicted FEV1 ranged from 54% to 95% (mean 75% +/- 11%) of the preoperative values. Two cases with obviously erroneous LFT were excluded from analysis. Mean error of predicted FEV1 was 20 +/- 160 ml, indicating absence of systematic error; mean absolute error was 7.4 +/- 3.3% respective 137 +/- 77 ml/s. The 200 ml reproducibility criterion for FEV1 was met in 11 of 13 cases (85%). In conclusion, software-assisted prediction of postoperative lung function yielded a clinically acceptable agreement with the observed postoperative values. This method might add useful information for evaluation of functional operability of patients with lung cancer.

The left-right asymmetry of liver lobation is generated by Pitx2c-mediated asymmetries in the hepatic diverticulum.

PubMed

Womble, Mandy; Amin, Nirav M; Nascone-Yoder, Nanette

2018-07-15

Internal organs exhibit left-right asymmetric sizes, shapes and anatomical positions, but how these different lateralities develop is poorly understood. Here we use the experimentally tractable Xenopus model to uncover the morphogenetic events that drive the left-right asymmetrical lobation of the liver. On the right side of the early hepatic diverticulum, endoderm cells become columnar and apically constricted, forming an expanded epithelial surface and, ultimately, an enlarged right liver lobe. In contrast, the cells on the left side become rounder, and rearrange into a compact, stratified architecture that produces a smaller left lobe. Side-specific gain- and loss-of-function studies reveal that asymmetric expression of the left-right determinant Pitx2c elicits distinct epithelial morphogenesis events in the left side of the diverticulum. Surprisingly, the cellular events induced by Pitx2c during liver development are opposite those induced in other digestive organs, suggesting divergent cellular mechanisms underlie the formation of different lateralities. Copyright © 2018 Elsevier Inc. All rights reserved.

Qualitative and quantitative effects of harmonic echocardiographic imaging on endocardial edge definition and side-lobe artifacts

NASA Technical Reports Server (NTRS)

Rubin, D. N.; Yazbek, N.; Garcia, M. J.; Stewart, W. J.; Thomas, J. D.

2000-01-01

Harmonic imaging is a new ultrasonographic technique that is designed to improve image quality by exploiting the spontaneous generation of higher frequencies as ultrasound propagates through tissue. We studied 51 difficult-to-image patients with blinded side-by-side cineloop evaluation of endocardial border definition by harmonic versus fundamental imaging. In addition, quantitative intensities from cavity versus wall were compared for harmonic versus fundamental imaging. Harmonic imaging improved left ventricular endocardial border delineation over fundamental imaging (superior: harmonic = 71.1%, fundamental = 18.7%; similar: 10.2%; P <.001). Quantitative analysis of 100 wall/cavity combinations demonstrated brighter wall segments and more strikingly darker cavities during harmonic imaging (cavity intensity on a 0 to 255 scale: fundamental = 15.6 +/- 8.6; harmonic = 6.0 +/- 5.3; P <.0001), which led to enhanced contrast between the wall and cavity (1.89 versus 1.19, P <.0001). Harmonic imaging reduces side-lobe artifacts, resulting in a darker cavity and brighter walls, thereby improving image contrast and endocardial delineation.

Preoperative EEG predicts memory and selective cognitive functions after temporal lobe surgery.

PubMed Central

Tuunainen, A; Nousiainen, U; Hurskainen, H; Leinonen, E; Pilke, A; Mervaala, E; Vapalahti, M; Partanen, J; Riekkinen, P

1995-01-01

Preoperative and postoperative cognitive and memory functions, psychiatric outcome, and EEGs were evaluated in 32 epileptic patients who underwent temporal lobe surgery. The presence and location of preoperative slow wave focus in routine EEG predicted memory functions of the non-resected side after surgery. Neuropsychological tests of the function of the frontal lobes also showed improvement. Moreover, psychiatric ratings showed that seizure free patients had significantly less affective symptoms postoperatively than those who were still exhibiting seizures. After temporal lobectomies, successful outcome in postoperative memory functions can be achieved in patients with unilateral slow wave activity in preoperative EEGs. This study suggests a new role for routine EEG in preoperative evaluation of patients with temporal lobe epilepsy. PMID:7608663

Acoustical Techniques/Designs Investigated During the Southeast Asia Conflict 1966-1972

DTIC Science & Technology

1981-01-21

the inbuoy processor above, the three sensor channels, two directional and one omni, are multi - plexed together and via the RF link transmitted back to...width at the 10 db dco;.n points and mnximtum side lobe level of -15 db) requires at least six’ elements in the line. At a geometric wean frequency of...presentation provides the data to the operator in the most accessible format. The vehicle descriptors are easily extracted with the aid of multi -point

Temporal lobe epilepsy in a cat with a pyriform lobe oligodendroglioma and hippocampal necrosis.

PubMed

Vanhaesebrouck, An E; Posch, Barbara; Baker, Sam; Plessas, Ioannis N; Palmer, Anthony C; Constantino-Casas, Fernando

2012-12-01

A 14-year-old male domestic shorthair cat presented with an acute onset of aggressive behaviour, fear and hypersalivation. Neurological examination revealed bilateral mydriasis and left-sided facial twitching and hemiparesis. Magnetic resonance imaging (MRI) showed moderate bilateral symmetrical T2-hyperintensity along the entire hippocampus and bilateral asymmetric T2-hyperintensity in the pyriform lobes. Marked bilateral contrast enhancement of the hippocampus was evident on post-contrast T1-weighted images. The partial complex seizures were refractory to medical treatment and the cat was euthanased 4 days after admission. The clinical and MRI findings were consistent with feline hippocampal necrosis (FHN). On histopathology, neuronal necrosis and astrocytosis were present in the hippocampi and pyriform lobes. In addition, an oligodendroglioma was detected in the right pyriform lobe. Contrary to previous reports of FHN in which no underlying cause could be identified, we believe that in this case the seizure focus arose from a neoplastic lesion within the right pyriform lobe. This unique case report represents the so-called 'dual pathology' of temporal lobe epilepsy in humans, in which an extrahippocampal lesion within the temporal lobe results in hippocampal sclerosis.

The IASLC Lung Cancer Staging Project: Background Data and Proposals for the Classification of Lung Cancer with Separate Tumor Nodules in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer.

PubMed

Detterbeck, Frank C; Bolejack, Vanessa; Arenberg, Douglas A; Crowley, John; Donington, Jessica S; Franklin, Wilbur A; Girard, Nicolas; Marom, Edith M; Mazzone, Peter J; Nicholson, Andrew G; Rusch, Valerie W; Tanoue, Lynn T; Travis, William D; Asamura, Hisao; Rami-Porta, Ramón

2016-05-01

Separate tumor nodules with the same histologic appearance occur in the lungs in a small proportion of patients with primary lung cancer. This article addresses how such tumors can be classified to inform the eighth edition of the anatomic classification of lung cancer. Separate tumor nodules should be distinguished from second primary lung cancer, multifocal ground glass/lepidic tumors, and pneumonic-type lung cancer, which are addressed in separate analyses. Survival of patients with separate tumor nodules in the International Association for the Study of Lung Cancer database were analyzed. This was compared with a systematic literature review. Survival of clinically staged patients decreased according to the location of the separate tumor nodule relative to the index tumor (same lobe > same side > other side) in N0 and N-any cohorts (all M0 except possible other-side nodules). However, there was also a decrease in the proportion of patients resected; among only surgically resected or among nonresected patients no survival differences were noted. There were no survival differences between patients with same-lobe nodules and those with other T3 tumors, between patients with same-side nodules and those with T4 tumors, and patients with other-side nodules and those with other M1a tumors. The data correlated with those identified in a literature review. Tumors with same-lobe separate tumor nodules (with the same histologic appearance) are recommended to be classified as T3, same-side nodules as T4, and other-side nodules as M1a. Thus, there is no recommended change between the seventh and eighth edition of the TNM classification of lung cancer. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

System overview on electromagnetic compensation for reflector antenna surface distortion

NASA Technical Reports Server (NTRS)

Acosta, R. J.; Zaman, A. J.; Terry, J. D.

1993-01-01

The system requirements and hardware implementation for electromagnetic compensation of antenna performance degradations due to thermal effects was investigated. Future commercial space communication antenna systems will utilize the 20/30 GHz frequency spectrum and support very narrow multiple beams (0.3 deg) over wide angle field of view (15-20 beamwidth). On the ground, portable and inexpensive very small aperture terminals (VSAT) for transmitting and receiving video, facsimile and data will be employed. These types of communication system puts a very stringent requirement on spacecraft antenna beam pointing stability (less than .01 deg), high gain (greater than 50 dB) and very lowside lobes (less than -25 dB). Thermal analysis performed on the advanced communication technology satellite (ACTS) has shown that the reflector surfaces, the mechanical supporting structures and metallic surfaces on the spacecraft body will distort due thermal effects from a varying solar flux. The antenna performance characteristics (e.g., pointing stability, gain, side lobe, etc.) will degrade due to thermal distortion in the reflector surface and supporting structures. Specifically, antenna RF radiation analysis has shown that pointing error is the most sensitive antenna performance parameter to thermal distortions. Other antenna parameters like peak gain, cross polarization level (beam isolation), and side lobe level will also degrade with thermal distortions. In order to restore pointing stability and in general antenna performance several compensation methods were proposed. In general these compensation methods can be classified as being either of mechanical or electromagnetic type. This paper will address only the later one. In this approach an adaptive phased array antenna feed is used to compensate for the antenna performance degradation. Extensive work has been devoted to demonstrate the feasibility of adaptive feed compensation on space communication antenna systems. This paper addresses the system requirements for such a system and identify candidate technologies (analog and digital) for possible hardware implementation.

Insights into Intrinsic Brain Networks based on Graph Theory and PET in right- compared to left-sided Temporal Lobe Epilepsy.

PubMed

Vanicek, Thomas; Hahn, Andreas; Traub-Weidinger, Tatjana; Hilger, Eva; Spies, Marie; Wadsak, Wolfgang; Lanzenberger, Rupert; Pataraia, Ekaterina; Asenbaum-Nan, Susanne

2016-06-28

The human brain exhibits marked hemispheric differences, though it is not fully understood to what extent lateralization of the epileptic focus is relevant. Preoperative [(18)F]FDG-PET depicts lateralization of seizure focus in patients with temporal lobe epilepsy and reveals dysfunctional metabolic brain connectivity. The aim of the present study was to compare metabolic connectivity, inferred from inter-regional [(18)F]FDG PET uptake correlations, in right-sided (RTLE; n = 30) and left-sided TLE (LTLE; n = 32) with healthy controls (HC; n = 31) using graph theory based network analysis. Comparing LTLE and RTLE and patient groups separately to HC, we observed higher lobar connectivity weights in RTLE compared to LTLE for connections of the temporal and the parietal lobe of the contralateral hemisphere (CH). Moreover, especially in RTLE compared to LTLE higher local efficiency were found in the temporal cortices and other brain regions of the CH. The results of this investigation implicate altered metabolic networks in patients with TLE specific to the lateralization of seizure focus, and describe compensatory mechanisms especially in the CH of patients with RTLE. We propose that graph theoretical analysis of metabolic connectivity using [(18)F]FDG-PET offers an important additional modality to explore brain networks.

Levator Glandulae Thyroideae, a Fibromusculoglandular Band with Absence of Pyramidal Lobe and Its Innervation: A Case Report

PubMed Central

Chaudhary, Priti; Singh, Zora; Khullar, Meenakshi; Arora, Kamal

2013-01-01

Amongst the endocrine glands, thyroid gland is well known for its developmental anomalies, which range from common to rare ones. The presence of levator glandulae thyroideae and its anatomical variations gain importance in the pathologies which are related to thyroid gland and their treatment modalities. Levator glandulae thyroideae is a fibromuscular band. If it is present, it is usually seen on the left side, to connect the pyramidal lobe of thyroid gland and the hyoid bone. But levator glandulae thyroideae which stretches from isthmus to the body of hyoid bone is rare and only very few cases have been reported in the medical literature. During a routine dissection of the thyroid gland in a 55 years old male cadaver, a Levator Glandulae Thyroideae (which was fibromusculoglandular in nature) was seen, with the absence of pyramidal lobe on the left side. It directly came from upper border of isthmus and went upto hyoid bone. It also had innervation from branches of external laryngeal nerve. This was also associated with absence of superior thyroid artery on the same side. The knowledge on various developmental anomalies of the gland and variations in neurovascular relations will help the surgeons in plan thyroid surgeries in a better and safe way. PMID:23998080

Proper name retrieval in temporal lobe epilepsy: naming of famous faces and landmarks.

PubMed

Benke, Thomas; Kuen, Eva; Schwarz, Michael; Walser, Gerald

2013-05-01

The objective of this study was to further explore proper name (PN) retrieval and conceptual knowledge in patients with left and right temporal lobe epilepsy (69 patients with LTLE and 62 patients with RTLE) using a refined assessment procedure. Based on the performance of a large group of age- and education-matched normals, a new test of famous faces and famous landmarks was designed. Recognition, naming, and semantic knowledge were assessed consecutively, allowing for a better characterization of deficient levels in the naming system. Impairment in PN retrieval was common in the cohort with TLE. Furthermore, side of seizure onset impaired stages of name retrieval differently: LTLE impaired the lexico-phonological processing, whereas RTLE mainly impaired the perceptual-semantic stage of object recognition. In addition to deficient PN retrieval, patients with TLE had reduced conceptual knowledge regarding famous persons and landmarks. Copyright © 2013 Elsevier Inc. All rights reserved.

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

Madin, Mark Michael; Wicks, Christopher Donald

A cam carrier assembly includes a body made of a material lighter than aluminum. The body has a first side operably coupled with a cylinder head and a second side having bearing surfaces with bearing inserts. The bearing inserts support the camshaft. A series of apertures extend between the first and second sides of the body. Lobes of the camshaft operably couple with the valves of the cylinder head through the series of apertures extending between the first and second sides of the body.

A 4-Week Preoperative Ketogenic Micronutrient-Enriched Diet Is Effective in Reducing Body Weight, Left Hepatic Lobe Volume, and Micronutrient Deficiencies in Patients Undergoing Bariatric Surgery: a Prospective Pilot Study.

PubMed

Schiavo, Luigi; Pilone, Vincenzo; Rossetti, Gianluca; Barbarisi, Alfonso; Cesaretti, Manuela; Iannelli, Antonio

2018-03-03

Before bariatric surgery (BS), moderate weight loss, left hepatic lobe volume reduction, and micronutrient deficiency (MD) identification and correction are desirable. The objective of this study was to assess the safety and the effectiveness of a 4-week preoperative ketogenic micronutrient-enriched diet (KMED) in reducing body weight (BW), left hepatic lobe volume, and correcting MD in patients scheduled for BS. In this prospective pilot study, a cohort of morbidly obese patients (n = 27, 17 females, 10 males) with a mean body mass index (BMI) of 45.2 kg/m 2 scheduled for BS underwent a 4-week preoperative KMED. Their BW, BMI, fat mass (FM), fat-free mass (FFM), resting metabolic rate (RMR), left hepatic lobe volume, micronutrient status, and biochemical and metabolic patterns were measured before and after the 4-week KMED. Patient compliance was assessed by validated questionnaires (3-day estimated food records and 72-h recall). Qualitative methods (5-point Likert questionnaire) were used to measure diet acceptability and side effects. All patients completed the study. We observed highly significant decreases in BW (- 10.3%, p < 0.001, in males; - 8.2%, p < 0.001, in females), left hepatic lobe volume (- 19.8%, p < 0.001), and an amelioration of patient micronutrient status. All patients showed a high frequency of acceptability and compliance in following the diet. No adverse side effect was reported. This study demonstrates that a 4-week preoperative KMED is safe and effective in reducing BW, left hepatic lobe volume, and correcting MD in obese patients scheduled for BS.

An innovative, highly sensitive receiver system for the Square Kilometre Array Mid Radio Telescope

NASA Astrophysics Data System (ADS)

Tan, Gie Han; Lehmensiek, Robert; Billade, Bhushan; Caputa, Krzysztof; Gauffre, Stéphane; Theron, Isak P.; Pantaleev, Miroslav; Ljusic, Zoran; Quertier, Benjamin; Peens-Hough, Adriaan

2016-07-01

The Square Kilometre Array (SKA) Project is a global science and engineering project realizing the next-generation radio telescopes operating in the metre and centimetre wavelengths regions. This paper addresses design concepts of the broadband, exceptionally sensitive receivers and reflector antennas deployed in the SKA1-Mid radio telescope to be located in South Africa. SKA1-Mid (350 MHz - 13.8 GHz with an option for an upper limit of 24 GHz) will consist of 133 reflector antennas using an unblocked aperture, offset Gregorian configuration with an effective diameter of 15 m. Details on the unblocked aperture Gregorian antennas, low noise front ends and advanced direct digitization receivers, are provided from a system design perspective. The unblocked aperture results in increased aperture efficiency and lower side-lobe levels compared to a traditional on-axis configuration. The low side-lobe level reduces the noise contribution due to ground pick-up but also makes the antenna less susceptible to ground-based RFI sources. The addition of extra shielding on the sub-reflector provides a further reduction of ground pick-up. The optical design of the SKA1-Mid reflector antenna has been tweaked using advanced EM simulation tools in combination with sophisticated models for sky, atmospheric and ground noise contributions. This optimal antenna design in combination with very low noise, partially cryogenic, receivers and wide instantaneous bandwidth provide excellent receiving sensitivity in combination with instrumental flexibility to accommodate a wide range of astronomical observation modes.

Atypical handedness in mesial temporal lobe epilepsy.

PubMed

Doležalová, Irena; Schachter, Steven; Chrastina, Jan; Hemza, Jan; Hermanová, Markéta; Rektor, Ivan; Pažourková, Marta; Brázdil, Milan

2017-07-01

The main aim of our study was to investigate the handedness of patients with mesial temporal lobe epilepsy (MTLE). We also sought to identify clinical variables that correlated with left-handedness in this population. Handedness (laterality quotient) was assessed in 73 consecutive patients with MTLE associated with unilateral hippocampal sclerosis (HS) using the Edinburgh Handedness Inventory. Associations between right- and left-handedness and clinical variables were investigated. We found that 54 (74.0%) patients were right-handed, and 19 (26%) patients were left-handed. There were 15 (36.6%) left-handed patients with left-sided seizure onset compared to 4 (12.5%) left-handed patients with right-sided seizure onset (p=0.030). Among patients with left-sided MTLE, age at epilepsy onset was significantly correlated with handedness (8years of age [median; min-max 0.5-17] in left-handers versus 15years of age [median; min-max 3-30] in right-handers (p<0.001). Left-sided MTLE is associated with atypical handedness, especially when seizure onset occurs during an active period of brain development, suggesting a bi-hemispheric neuroplastic process for establishing motor dominance in patients with early-onset left-sided MTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

A RAND Analysis Tool for Intelligence, Surveillance, and Reconnaissance: The Collections Operations Model

DTIC Science & Technology

2008-01-01

appropriate; scan cycle, emission interval, or emission probability; frequency bands; relative angular size of 2 Carl Rhodes, Jeff Hagen, and Mark...choices based on its own perceptions. An agent has autonomy. 2 In this report, “behaviors” are individual scripts , programs, instructions, or decision...relative angular size of main and side lobes (for directional signals); and the effective radiated power of each radiative lobe. With these parameters and

An Improved Adaptive Received Beamforming for Nested Frequency Offset and Nested Array FDA-MIMO Radar

PubMed Central

Cheng, Sibei; Zhang, Qingjun; Bian, Mingming; Hao, Xinhong

2018-01-01

For the conventional FDA-MIMO (frequency diversity array multiple-input-multiple-output) Radar with uniform frequency offset and uniform linear array, the DOFs (degrees of freedom) of the adaptive beamformer are limited by the number of elements. A better performance—for example, a better suppression for strong interferences and a more desirable trade-off between the main lobe and side lobe—can be achieved with a greater number of DOFs. In order to obtain larger DOFs, this paper researches the signal model of the FDA-MIMO Radar with nested frequency offset and nested array, then proposes an improved adaptive beamforming method that uses the augmented matrix instead of the covariance matrix to calculate the optimum weight vectors and can be used to improve the output performances of FDA-MIMO Radar with the same element number or reduce the element number while maintain the approximate output performances such as the received beampattern, the main lobe width, side lobe depths and the output SINR (signal-to-interference-noise ratio). The effectiveness of the proposed scheme is verified by simulations. PMID:29419814

Mutual Coupling and Compensation in FMCW MIMO Radar Systems

NASA Astrophysics Data System (ADS)

Schmid, Christian M.; Feger, Reinhard; Wagner, Christoph; Stelzer, Andreas

2011-09-01

This paper deals with mutual coupling, its effects and the compensation thereof in frequency-modulated continuous-wave (FMCW) multiple-input multiple-output (MIMO) array radar systems. Starting with a signal model we introduce mutual coupling and its primary sources in FMCW MIMO systems. We also give a worst-case boundary of the effects that mutual coupling can have on the side lobe level of an array. A method of dealing with and compensating for these effects is covered in this paper and verified by measurements from a 77-GHz FMCW radar system.

Positive pressure ventilation in a patient with a right upper lobar bronchocutaneous fistula: right upper bronchus occlusion using the cuff of a left-sided double lumen endobronchial tube.

PubMed

Omori, Chieko; Toyama, Hiroaki; Takei, Yusuke; Ejima, Yutaka; Yamauchi, Masanori

2017-08-01

In patients with a bronchocutaneous fistula, positive pressure ventilation leads to air leakage and potential hypoxemia. A male patient with a right upper bronchocutaneous fistula was scheduled for esophageal reconstruction. His preoperative chest computed tomography image revealed aeration in the right middle and lower lobe, a large bulla in the left upper lobe, and pleural effusion and pneumonia in the left lower lobe. Therefore, left one-lung ventilation was considered to result in hypoxemia. Before anesthesia induction, the bronchocutaneous fistula was covered with gauze and film to prevent air leakage. After anesthesia induction, mask ventilation was performed with a peak positive pressure of 10 cmH 2 O. A left-sided double lumen endobronchial tube (DLT) was then inserted into the right main bronchus for occluding only the right superior bronchus, and two-lung ventilation was performed to minimize airway pressure and maintain oxygenation, which did not cause air leakage through the fistula. During anesthesia, no ventilation-related difficulty was faced. The method of inserting a left-sided DLT into the right main bronchus and occluding the right upper bronchus selectively by bronchial cuff is considered to be an option for mechanical ventilation in patients with a right upper bronchial fistula, as demonstrated in the present case.

The morphology, processes, and evolution of Monterey Fan: a revisit

USGS Publications Warehouse

Gardner, James V.; Bohannon, Robert G.; Field, Michael E.; Masson, Douglas G.

2010-01-01

Long-range (GLORIA) and mid-range (TOBI) sidescan imagery and seismic-reflection profiles have revealed the surface morphology and architecture of the complete Monterey Fan. The fan has not developed a classic wedge shape because it has been blocked for much of its history by Morro Fracture Zone. The barrier has caused the fan to develop an upper-fan and lower-fan sequence that are distinctly different from one another. The upper-fan sequence is characterized by Monterey and Ascension Channels and associated Monterey Channel-levee system. The lower-fan sequence is characterized by depositional lobes of the Ascension, Monterey, and Sur-Parkington-Lucia systems, with the Monterey depositional lobe being the youngest. Presently, the Monterey depositional lobe is being downcut because the system has reached a new, lower base level in the Murray Fracture Zone. A five-step evolution of Monterey Fan is presented, starting with initial fan deposition in the Late Miocene, about 5.5 Ma. This first stage was one of filling bathymetric lows in the oceanic basement in what was to become the upper-fan segment. The second stage involved filling the bathymetric low on the north side of Morro Fracture Zone, and probably not much sediment was transported beyond the fracture zone. The third stage witnessed sediment being transported around both ends of Morro Fracture Zone and initial sedimentation on the lower-fan segment. During the fourth stage Ascension Channel was diverted into Monterey Channel, thereby cutting off sedimentation to the Ascension depositional lobe.

Evidence for Gradual External Reconnection Before Explosive Eruption of a Solar Filament

NASA Technical Reports Server (NTRS)

Sterling, Alphonse C.; Moore, Ronald L.

2003-01-01

We observe a slowly-evolving quiet region solar eruption of 1999 April 18, using EUV images from the EUV Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO), and soft X-ray images from the Soft X-ray Telescope (SXT) on Yohkoh. Using difference images, where an early image is subtracted from later images, we examine dimmings and brightenings in the region for evidence of the eruption mechanism. A filament rose slowly at about 1 kilometer per second for six hours before being rapidly ejected at about 16 kilometers per second, leaving flare brightenings and post-flare loops in its wake. Magnetograms from the Michelson Doppler Imager (MDI) on SOHO show that the eruption occurred in a large quadrupo1ar magnetic region, with the filament located on the neutral line of the quadrupole's central inner lobe, between the inner two of the four polarity domains. In step with the slow rise, subtle EIT dimmings commence and gradually increase over the two polarity domains on one side of the filament, i.e. in some of the loops of one of the two side lobes of the quadrupole. Concurrently, soft X-ray brightenings gradually increase in both side lobes. Both of these effects suggest heating in the side-lobe magnetic arcades, which gradually increase over several hours before the fast eruption. Also during the slow pre-eruption phase, SXT dimmings gradually increase in the feet and legs of the central lobe, indicating expansion of the central-lobe magnetic arcade enveloping the filament. During the rapid ejection, these dimmings rapidly grow in darkness and in area, especially in the ends of the sigmoid field that erupts with the filament, and flare brightenings begin underneath the fast-moving but still low-altitude filament. We consider two models for explaining the eruption: "breakout," which says that reconnection occurs high above the filament prior to eruption, and tether cutting, which says that the eruption is unleashed by reconnection beneath the filament. The pre-eruption evolution is consistent with gradual breakout that led to (and perhaps caused) the fast eruption. Tether-cutting reconnection below the filament begins early in the rapid ejection, but our data are not complete enough to determine whether this reconnection began early enough to be the cause of the fast-phase onset. Thus, our observations are consistent with gradual breakout reconnection causing the long slow rise of the filament, but allow the cause of the sudden onset of the explosive fast phase to be either a jump in the breakout reconnection rate or the onset of runaway tether-cutting reconnection, or both.

Physics of tissue harmonic imaging by ultrasound

NASA Astrophysics Data System (ADS)

Jing, Yuan

Tissue Harmonic Imaging (THI) is an imaging modality that is currently deployed on diagnostic ultrasound scanners. In THI the amplitude of the ultrasonic pulse that is used to probe the tissue is large enough that the pulse undergoes nonlinear distortion as it propagates into the tissue. One result of the distortion is that as the pulse propagates energy is shifted from the fundamental frequency of the source pulse into its higher harmonics. These harmonics will scatter off objects in the tissue and images formed from the scattered higher harmonics are considered to have superior quality to the images formed from the fundamental frequency. Processes that have been suggested as possibly responsible for the improved imaging in THI include: (1) reduced sensitivity to reverberation, (2) reduced sensitivity to aberration, and (3) reduction in side lobes. By using a combination of controlled experiments and numerical simulations, these three reasons have been investigated. A single element transducer and a clinical ultrasound scanner with a phased array transducer were used to image a commercial tissue-mimicking phantom with calibrated targets. The higher image quality achieved with THI was quantified in terms of spatial resolution and "clutter" signals. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed. A time-domain code for solving the KZK equation was validated with measurements of the acoustic field generated by the single element transducer and the phased array transducer. The code was used to investigate the impact of aberration using tissue-like media with three-dimensional variations in all acoustic properties. The three-dimensional maps of tissue properties were derived from the datasets available through the Visible Female project. The experiments and simulations demonstrated that second harmonic imaging (1) suffers less clutter associated with reverberation; (2) is not immune to aberration effects and (3) suffers less clutter due to reduced side-lobe levels. The results indicate that side lobe suppression is the most significant reason for the improvement of second harmonic imaging.

Conception and realization of a semiconductor based 240 GHz full 3D MIMO imaging system

NASA Astrophysics Data System (ADS)

Weisenstein, Christian; Kahl, Matthias; Friederich, Fabian; Haring Bolívar, Peter

2017-02-01

Multiple-input multiple-output (MIMO) imaging systems in the terahertz frequency range have a high potential in the field of non-destructive testing (NDT). With such systems it is possible to detect defects in composite materials, for example cracks or delaminations in fiber composites. To investigate mass-produced products it is necessary to study the objects in close to real-time on a conveyor without affecting the production cycle time. In this work we present the conception and realization of a 3D MIMO imaging system for in-line investigation of composite materials and structures. To achieve a lateral resolution of 1 mm, in order to detect such small defects in composite materials with a moderate number of elements, precise sensor design is crucial. In our approach we use the effective aperture concept. The designed sparse array consists of 32 transmitters and 30 receivers based on planar semiconductor components. High range resolution is achieved by an operating frequency between 220 GHz and 260 GHz in a stepped frequency continuous wave (SFCW) setup. A matched filter approach is used to simulate the reconstructed 3D image through the array. This allows the evaluation of the designed array geometry in regard of resolution and side lobe level. In contrast to earlier demonstrations, in which synthetic reconstruction is only performed in a 2D plane, an optics-free full 3D recon- struction has been implemented in our concept. Based on this simulation we designed an array geometry that enables to resolve objects with a resolution smaller than 1mm and moderate side lobe level.

Decision making under ambiguity and under risk in mesial temporal lobe epilepsy.

PubMed

Delazer, Margarete; Zamarian, Laura; Bonatti, Elisabeth; Kuchukhidze, Giorgi; Koppelstätter, Florian; Bodner, Thomas; Benke, Thomas; Trinka, Eugen

2010-01-01

Decision making is essential in everyday life. Though the importance of the mesial temporal lobe in emotional processing and feedback learning is generally recognized, decision making in mesial temporal lobe epilepsy (mTLE) is almost unexplored so far. Twenty-eight consecutive epilepsy patients with drug resistant mTLE and fifty healthy controls performed decision tasks under initial ambiguity (participants have to learn by feedback to make advantageous decisions) and under risk (advantageous choices may be made by estimating risks and by rational strategies). A subgroup analysis compared the performance of patients affected by MRI-verified abnormalities of the hippocampus or amygdala. The effect of lesion side was also assessed. In decision under ambiguity, mTLE patients showed marked deficits and did not improve over the task. Patients with hippocampus abnormality and patients with amygdala abnormality showed comparable deficits. No difference was found between right and left TLE groups. In decision under risk, mTLE patients performed at the same level as controls. Results suggest that mTLE patients have difficulties in learning from feedback and in making decisions in uncertain, ambiguous situations. By contrast, they are able to make advantageous decisions when full information is given and risks, possible gains and losses are exactly defined.

Crossed aphasia following cerebral infarction in a right-handed patient with atypical cerebral language dominance.

PubMed

Tan, Xiaoping; Guo, Yang; Dun, Saihong; Sun, Hongzan

2018-05-18

Crossed aphasia (CA), usually referred to as an acquired language disturbance, is caused by a lesion in the cerebral hemisphere ipsilateral to the dominant hand, and the exact mechanism is not clear. The development of handedness is influenced by education and training and the impact of habitualization, while language is more susceptible to the impact of speech habits, and it is not absolutely accurate to judge cerebral language dominance by the degree of hand preference. We describe a case of CA after right hemispheric stroke in a right-handed patient with atypical language dominance and attempt to analyze the mechanism of CA based on functional imaging methods, including arterial spin labeling (ASL) and positron emission tomography/magnetic resonance imaging (PET-MRI). Brain MRI at 24 h after admission showed a large cerebral infarction in the right cerebral hemisphere, including the posteroinferior part of Broca's area in the right frontal lobe, the right temporal lobe, and the right occipital lobe. The patient exhibited a non-fluent aphasia on a standard language test (the Aphasia Battery of Chinese [ABC]) performed on the 7th day after onset. Thus, atypical language dominance was suspected. One week after admission, ASL imaging showed high perfusion in the infarct core zone and low perfusion in the left cerebellar hemisphere. Two months later, PET/MRI demonstrated low metabolism in the posterior frontal lobe, temporal lobe, temporal occipital junction area, and the right basal ganglia. The findings suggest that the patient has right-sided cerebral language dominance, or that both hemispheres have linguistic functions. Not all patients show linguistic capabilities on the side opposite hand preference. The language dominance should be predicted by a combination of clinical manifestations and functional imaging techniques.

External validation of a nomogram for prediction of side-specific extracapsular extension at robotic radical prostatectomy.

PubMed

Zorn, Kevin C; Gallina, Andrea; Hutterer, Georg C; Walz, Jochen; Shalhav, Arieh L; Zagaja, Gregory P; Valiquette, Luc; Gofrit, Ofer N; Orvieto, Marcelo A; Taxy, Jerome B; Karakiewicz, Pierre I

2007-11-01

Several staging tools have been developed for open radical prostatectomy (ORP) patients. However, the validity of these tools has never been formally tested in patients treated with robot-assisted laparoscopic radical prostatectomy (RALP). We tested the accuracy of an ORP-derived nomogram in predicting the rate of extracapsular extension (ECE) in a large RALP cohort. Serum prostate specific antigen (PSA) and side-specific clinical stage and biopsy Gleason sum information were used in a previously validated nomogram predicting side-specific ECE. The nomogram-derived predictions were compared with the observed rate of ECE, and the accuracy of the predictions was quantified. Each prostate lobe was analyzed independently. As complete data were available for 576 patients, the analyses targeted 1152 prostate lobes. Median age and serum PSA concentration at radical prostatectomy were 60 years and 5.4 ng/mL, respectively. The majority of side-specific clinical stages were T(1c) (993; 86.2%). Most side-specific biopsy Gleason sums were 6 (572; 49.7%). The median side-specific percentages of positive cores and of cancer were, respectively, 20.0% and 5.0%. At final pathologic review, 107 patients (18.6%) had ECE, and side-specific ECE was present in 117 patients (20.3%). The nomogram was 89% accurate in the RALP cohort v 84% in the previously reported ORP validation. The ORP side-specific ECE nomogram is highly accurate in the RALP population, suggesting that predictive and possibly prognostic tools developed in ORP patients may be equally accurate in their RALP counterparts.

Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004

NASA Astrophysics Data System (ADS)

Nentwig, Vanessa; Bahlburg, Heinrich; Monthy, Devis

2015-03-01

The Seychelles, an archipelago in the Indian Ocean at a distance of 4,500-5,000 km from the west coast of Sumatra, were severely affected by the December 26, 2004 tsunami with wave heights up to 4 m. Since the tsunami history of small islands often remains unclear due to a young historical record, it is important to study the geological traces of high energy events preserved along their coasts. We conducted a survey of the impact of the 2004 Indian Ocean tsunami on the inner Seychelles islands. In detail we studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond in the Curieuse Marine National Park on the east coast of Curieuse Island. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami in 2004 by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap and assuring a low energetic hydrodynamic environment for the protection of the mangroves. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The tsunami caused a change of habitat by the sedimentation of sand lobes in the mangrove forest. The dark organic rich mangrove soil (1.9 Φ) was covered by bimodal fine to medium carbonate sand (1.7-2.2 Φ) containing coarser carbonate shell fragments and debris. Intertidal sediments and the mangrove soil acted as sources of the lobe deposits. The sand sheet deposited by the tsunami is organized into different lobes. They extend landwards to different inundation distances as a function of the morphology of the onshore area. The maximum extent of 180 m from the shoreline indicates the minimum inundation distance to the tsunami. The top parts of the sand lobes cover the pneumatophores of the mangroves. There is no landward fining trend along the sand lobes and normal grading of the deposits is rare, occurring only in 1 of 7 sites. The sand lobe deposits also lack sedimentary structures. On the surface of the sand lobes numerous mostly fragmented shells of bivalves and molluscs were distributed up to 150 m from the coastline. Intact bivalve shells were mostly found positioned with the convex side upwards. On small ledges of a granitic body at 130-150 m from the shore mostly fragmented and gravel sized shells were deposited at different elevations up to 4 m above sea level. This implies a run up height of at least 4 m above sea level up to 150 m from the present shoreline.

Occia Crater

NASA Image and Video Library

2012-05-10

This image from NASA Dawn spacecraft of asteroid Vesta shows Occia crater, located in Vesta Gegania quadrangle, in Vesta southern hemisphere. A distinctive butterfly pattern is seen consisting of two separate lobes of ejecta on the opposite sides.

Range resolution improvement in passive bistatic radars using nested FM channels and least squares approach

NASA Astrophysics Data System (ADS)

Arslan, Musa T.; Tofighi, Mohammad; Sevimli, Rasim A.; ćetin, Ahmet E.

2015-05-01

One of the main disadvantages of using commercial broadcasts in a Passive Bistatic Radar (PBR) system is the range resolution. Using multiple broadcast channels to improve the radar performance is offered as a solution to this problem. However, it suffers from detection performance due to the side-lobes that matched filter creates for using multiple channels. In this article, we introduce a deconvolution algorithm to suppress the side-lobes. The two-dimensional matched filter output of a PBR is further analyzed as a deconvolution problem. The deconvolution algorithm is based on making successive projections onto the hyperplanes representing the time delay of a target. Resulting iterative deconvolution algorithm is globally convergent because all constraint sets are closed and convex. Simulation results in an FM based PBR system are presented.

Suppression of side lobes in a spectrum of fibre Bragg gratings due to the transverse displacement of phase mask with respect to the optical fibre

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

Abdullina, S R; Nemov, I N; Babin, Sergei A

2012-09-30

The possibility of apodisation of fibre Bragg gratings (FBGs) recorded in the interference region of two Gaussian beams in the phase-mask scheme is considered. The FBG reflection spectra are numerically simulated for different values of recordingbeam parameters and the distance between the axes of interfering beams diffracted into different orders, which is varied by transverse displacement of the phase mask with respect to the optical fibre. Suppression of side lobes and smoothing out of the FBG spectrum with an increase in the transverse displacement of the phase mask is experimentally demonstrated. It is shown that this effect is caused bymore » the equalisation of the mean induced refractive index in the FBG region. (optical fibres, lasers and amplifiers. properties and applications)« less

Analysis of EEG Related Saccadic Eye Movement

NASA Astrophysics Data System (ADS)

Funase, Arao; Kuno, Yoshiaki; Okuma, Shigeru; Yagi, Tohru

Our final goal is to establish the model for saccadic eye movement that connects the saccade and the electroencephalogram(EEG). As the first step toward this goal, we recorded and analyzed the saccade-related EEG. In the study recorded in this paper, we tried detecting a certain EEG that is peculiar to the eye movement. In these experiments, each subject was instructed to point their eyes toward visual targets (LEDs) or the direction of the sound sources (buzzers). In the control cases, the EEG was recorded in the case of no eye movemens. As results, in the visual experiments, we found that the potential of EEG changed sharply on the occipital lobe just before eye movement. Furthermore, in the case of the auditory experiments, similar results were observed. In the case of the visual experiments and auditory experiments without eye movement, we could not observed the EEG changed sharply. Moreover, when the subject moved his/her eyes toward a right-side target, a change in EEG potential was found on the right occipital lobe. On the contrary, when the subject moved his/her eyes toward a left-side target, a sharp change in EEG potential was found on the left occipital lobe.

Comparison of active-set method deconvolution and matched-filtering for derivation of an ultrasound transit time spectrum.

PubMed

Wille, M-L; Zapf, M; Ruiter, N V; Gemmeke, H; Langton, C M

2015-06-21

The quality of ultrasound computed tomography imaging is primarily determined by the accuracy of ultrasound transit time measurement. A major problem in analysis is the overlap of signals making it difficult to detect the correct transit time. The current standard is to apply a matched-filtering approach to the input and output signals. This study compares the matched-filtering technique with active set deconvolution to derive a transit time spectrum from a coded excitation chirp signal and the measured output signal. The ultrasound wave travels in a direct and a reflected path to the receiver, resulting in an overlap in the recorded output signal. The matched-filtering and deconvolution techniques were applied to determine the transit times associated with the two signal paths. Both techniques were able to detect the two different transit times; while matched-filtering has a better accuracy (0.13 μs versus 0.18 μs standard deviations), deconvolution has a 3.5 times improved side-lobe to main-lobe ratio. A higher side-lobe suppression is important to further improve image fidelity. These results suggest that a future combination of both techniques would provide improved signal detection and hence improved image fidelity.

Adaptive near-field beamforming techniques for sound source imaging.

PubMed

Cho, Yong Thung; Roan, Michael J

2009-02-01

Phased array signal processing techniques such as beamforming have a long history in applications such as sonar for detection and localization of far-field sound sources. Two sometimes competing challenges arise in any type of spatial processing; these are to minimize contributions from directions other than the look direction and minimize the width of the main lobe. To tackle this problem a large body of work has been devoted to the development of adaptive procedures that attempt to minimize side lobe contributions to the spatial processor output. In this paper, two adaptive beamforming procedures-minimum variance distorsionless response and weight optimization to minimize maximum side lobes--are modified for use in source visualization applications to estimate beamforming pressure and intensity using near-field pressure measurements. These adaptive techniques are compared to a fixed near-field focusing technique (both techniques use near-field beamforming weightings focusing at source locations estimated based on spherical wave array manifold vectors with spatial windows). Sound source resolution accuracies of near-field imaging procedures with different weighting strategies are compared using numerical simulations both in anechoic and reverberant environments with random measurement noise. Also, experimental results are given for near-field sound pressure measurements of an enclosed loudspeaker.

Bilateral temporal lobe volume reduction parallels cognitive impairment in progressive aphasia.

PubMed

Andersen, C; Dahl, C; Almkvist, O; Ostberg, P; Julin, P; Wahlund, L O

1997-10-01

Patients with isolated aphasia in the absence of other cognitive abnormalities have been the focus of several studies during the past decade. It has been called primary progressive aphasia (PPA), and the typical features of this syndrome are marked atrophy of the left temporal lobe according to the radiological examination and a language disorder as the initial symptom. In previous studies of PPA, the selection of the patients was based mainly on linguistic symptoms. Now, when computed tomography or magnetic resonance imaging scans are part of the routine investigation of cognitive impairment and suspected dementia, the patients with lobar atrophy will be found at an earlier stage. In the present study, we used a new approach and defined the study group by selecting patients with obvious left temporal lobe atrophy, assessed by MRI, and we referred to them as patients with temporal lobe atrophy (TLA). To identify the features that distinguish TLA from other primary neurodegenerative disorders. Six patients with TLA were compared with patients with Alzheimer disease (AD), patients with frontal lobe dementia (FLD), and healthy control subjects. The investigations included magnetic resonance imaging volumetry, single photon emission computed tomography, and neuropsychologic and linguistic evaluations. In the TLA group, the mean volume of the left temporal lobe was 35% smaller than the right, while in the AD and FLD groups, the atrophy was symmetrical and bilateral. In the TLA group, the absolute volumes of the temporal lobes were significantly smaller on the left side compared with the AD and FLD groups, whereas there was no difference on the right side. The cerebral blood flow pattern in TLA was asymmetric and differed from that in the other study groups. All patients with TLA had a history of progressive Wernicke-type aphasia, ranging from 2 to 6 years. They showed primary verbal memory impairment but had preserved visuospatial functions. The clinical condition of all patients with TLA deteriorated during the study period; severe aphasia developed, and the patients exhibited signs of frontal lobe dysfunction. Serial volumetric measurements in 4 of 6 patients showed an annual 8% to 9% decrease of both left and right temporal lobes. The initial marked asymmetry in cognitive function found in patients with TLA contrasts with the general decline found in patients with AD. The bilateral degenerative process evident in patients with TLA paralleled the clinical deterioration, indicating TLA to be a non-AD lobar atrophy that develops into generalized cognitive dysfunction and dementia.

Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

PubMed Central

Reyna, Alberto; Panduro, Marco A.; Del Rio Bocio, Carlos

2014-01-01

This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction. PMID:24701150

[Left ventricular projectile migration after an accidental close-range gunshot wound].

PubMed

Driessen, A; Tjardes, T; Eikermann, C; Trojan, S; Fröhlich, M; Grimaldi, G; Kosse, N

2016-07-01

We report the case of a 24-year-old female after sustaining a shotgun wound in the left upper extremity and chest. Initial emergency diagnostics revealed numerous shotgun pellets scattered throughout the left-side soft tissue, chest and upper lung lobe with one pellet having migrated into the left ventricle of the heart.Due to the devastating injury pattern, gunshot wounds are interdisciplinarily challenging and should include extended initial diagnostics, such as contrast agent CT. The potential toxicity of elevated lead blood levels have to be taken into further account.

Millimeter-Wave Wireless Power Transfer Technology for Space Applications

NASA Technical Reports Server (NTRS)

Chattopadhyay, Goutam; Manohara, Harish; Mojarradi, Mohammad M.; Vo, Tuan A.; Mojarradi, Hadi; Bae, Sam Y.; Marzwell, Neville

2008-01-01

In this paper we present a new compact, scalable, and low cost technology for efficient receiving of power using RF waves at 94 GHz. This technology employs a highly innovative array of slot antennas that is integrated on substrate composed of gold (Au), silicon (Si), and silicon dioxide (SiO2) layers. The length of the slots and spacing between them are optimized for a highly efficient beam through a 3-D electromagnetic simulation process. Antenna simulation results shows a good beam profile with very low side lobe levels and better than 93% antenna efficiency.

Double dipole antenna SIS receivers at 100 and 400 GHz

NASA Technical Reports Server (NTRS)

Skalare, A.; Vandestadt, H.; Degraauw, T.; Panhuyzen, R. A.; Dierichs, M. M. T. M.

1992-01-01

Antenna patterns were measured between 95 and 120 GHz for a double dipole antenna / ellipsoidal lens combination. The structure produces a non-astigmatic beam with low side lobe levels over that whole band. A heterodyne SIS receiver based on this concept gave a best noise temperature of 145 K DSB at 98 GHz. Measurements were also made with a 400 GHz heterodyne SIS receiver, using a double dipole antenna in conjunction with a hyperhemispherical lens. The best noise temperature was 220 K DSB at 402 GHz. On-chip stubs were used to tune out the SIS junction capacitance.

Right side neglect in right cerebellar lesion

PubMed Central

Silveri, M; Misciagna, S; Terrezza, G

2001-01-01

A patient is described who developed right side hemineglect after a right cerebellar lesion. This spatial disorder was interpreted as a secondary effect of a deficit of the motor organisation in the right hemispace due to left frontal diaschisis. The pathological base may be the interruption of a highly integrated system which includes the lateral cerebellum and the contralateral frontal lobe.

 PMID:11413276

Adaptive HIFU noise cancellation for simultaneous therapy and imaging using an integrated HIFU/imaging transducer

PubMed Central

Jeong, Jong Seob; Cannata, Jonathan Matthew; Shung, K Kirk

2010-01-01

It was previously demonstrated that it is feasible to simultaneously perform ultrasound therapy and imaging of a coagulated lesion during treatment with an integrated transducer that is capable of high intensity focused ultrasound (HIFU) and B-mode ultrasound imaging. It was found that coded excitation and fixed notch filtering upon reception could significantly reduce interference caused by the therapeutic transducer. During HIFU sonication, the imaging signal generated with coded excitation and fixed notch filtering had a range side-lobe level of less than −40 dB, while traditional short-pulse excitation and fixed notch filtering produced a range side-lobe level of −20 dB. The shortcoming is, however, that relatively complicated electronics may be needed to utilize coded excitation in an array imaging system. It is for this reason that in this paper an adaptive noise canceling technique is proposed to improve image quality by minimizing not only the therapeutic interference, but also the remnant side-lobe ‘ripples’ when using the traditional short-pulse excitation. The performance of this technique was verified through simulation and experiments using a prototype integrated HIFU/imaging transducer. Although it is known that the remnant ripples are related to the notch attenuation value of the fixed notch filter, in reality, it is difficult to find the optimal notch attenuation value due to the change in targets or the media resulted from motion or different acoustic properties even during one sonication pulse. In contrast, the proposed adaptive noise canceling technique is capable of optimally minimizing both the therapeutic interference and residual ripples without such constraints. The prototype integrated HIFU/imaging transducer is composed of three rectangular elements. The 6 MHz center element is used for imaging and the outer two identical 4 MHz elements work together to transmit the HIFU beam. Two HIFU elements of 14.4 mm × 20.0 mm dimensions could increase the temperature of the soft biological tissue from 55 °C to 71 °C within 60 s. Two types of experiments for simultaneous therapy and imaging were conducted to acquire a single scan-line and B-mode image with an aluminum plate and a slice of porcine muscle, respectively. The B-mode image was obtained using the single element imaging system during HIFU beam transmission. The experimental results proved that the combination of the traditional short-pulse excitation and the adaptive noise canceling method could significantly reduce therapeutic interference and remnant ripples and thus may be a better way to implement real-time simultaneous therapy and imaging. PMID:20224162

Adaptive HIFU noise cancellation for simultaneous therapy and imaging using an integrated HIFU/imaging transducer.

PubMed

Jeong, Jong Seob; Cannata, Jonathan Matthew; Shung, K Kirk

2010-04-07

It was previously demonstrated that it is feasible to simultaneously perform ultrasound therapy and imaging of a coagulated lesion during treatment with an integrated transducer that is capable of high intensity focused ultrasound (HIFU) and B-mode ultrasound imaging. It was found that coded excitation and fixed notch filtering upon reception could significantly reduce interference caused by the therapeutic transducer. During HIFU sonication, the imaging signal generated with coded excitation and fixed notch filtering had a range side-lobe level of less than -40 dB, while traditional short-pulse excitation and fixed notch filtering produced a range side-lobe level of -20 dB. The shortcoming is, however, that relatively complicated electronics may be needed to utilize coded excitation in an array imaging system. It is for this reason that in this paper an adaptive noise canceling technique is proposed to improve image quality by minimizing not only the therapeutic interference, but also the remnant side-lobe 'ripples' when using the traditional short-pulse excitation. The performance of this technique was verified through simulation and experiments using a prototype integrated HIFU/imaging transducer. Although it is known that the remnant ripples are related to the notch attenuation value of the fixed notch filter, in reality, it is difficult to find the optimal notch attenuation value due to the change in targets or the media resulted from motion or different acoustic properties even during one sonication pulse. In contrast, the proposed adaptive noise canceling technique is capable of optimally minimizing both the therapeutic interference and residual ripples without such constraints. The prototype integrated HIFU/imaging transducer is composed of three rectangular elements. The 6 MHz center element is used for imaging and the outer two identical 4 MHz elements work together to transmit the HIFU beam. Two HIFU elements of 14.4 mm x 20.0 mm dimensions could increase the temperature of the soft biological tissue from 55 degrees C to 71 degrees C within 60 s. Two types of experiments for simultaneous therapy and imaging were conducted to acquire a single scan-line and B-mode image with an aluminum plate and a slice of porcine muscle, respectively. The B-mode image was obtained using the single element imaging system during HIFU beam transmission. The experimental results proved that the combination of the traditional short-pulse excitation and the adaptive noise canceling method could significantly reduce therapeutic interference and remnant ripples and thus may be a better way to implement real-time simultaneous therapy and imaging.

Quantification of mu and non-mu opiate receptors in temporal lobe epilepsy using positron emission tomography.

PubMed

Mayberg, H S; Sadzot, B; Meltzer, C C; Fisher, R S; Lesser, R P; Dannals, R F; Lever, J R; Wilson, A A; Ravert, H T; Wagner, H N

1991-07-01

Alterations in a variety of neurotransmitter systems have been identified in experimental models of epilepsy and in brain tissue from patients with intractable temporal lobe seizures. The availability of new high-affinity radioligands permits the study of some neuroreceptors in vivo with positron emission tomography (PET). We previously characterized the in vivo binding of 11C-carfentanil, a potent and selective mu opiate receptor agonist, and described increases in 11C-carfentanil binding in the temporal neocortex of patients with unilateral temporal lobe epilepsy. These studies have been extended to 11C-diprenorphine, which labels mu, kappa, and delta opiate receptor subtypes. Paired measurements of opiate receptor binding were performed with PET using 11C-carfentanil and 11C-diprenorphine in patients with unilateral temporal lobe seizures. Carfentanil binding, reflecting changes in mu opiate receptors, was increased in the temporal neocortex and decreased in the amygdala on the side of the epileptic focus. Diprenorphine binding, reflecting mu as well as non-mu opiate subtypes, was not significantly different among regions in the focus and nonfocus temporal lobes. Regional glucose metabolism, measured using 18F-2-fluoro-2-deoxyglucose, was decreased in the mesial and lateral aspects of the temporal lobe ipsilateral to the epileptogenic focus. The variation in pattern of carfentanil and diprenorphine binding supports a differential regulation of opiate subtypes in unilateral temporal lobe epilepsy.

Sensitivity and specificity of memory and naming tests for identifying left temporal-lobe epilepsy.

PubMed

Umfleet, Laura Glass; Janecek, Julie K; Quasney, Erin; Sabsevitz, David S; Ryan, Joseph J; Binder, Jeffrey R; Swanson, Sara J

2015-01-01

The sensitivity and specificity of the Selective Reminding Test (SRT) Delayed Recall, Wechsler Memory Scale (WMS) Logical Memory, the Boston Naming Test (BNT), and two nonverbal memory measures for detecting lateralized dysfunction in association with side of seizure focus was examined in a sample of 143 patients with left or right temporal-lobe epilepsy (TLE). Scores on the SRT and BNT were statistically significantly lower in the left TLE group compared with the right TLE group, whereas no group differences emerged on the Logical Memory subtest. No significant group differences were found with nonverbal memory measures. When the SRT and BNT were both entered as predictors in a logistic regression, the BNT, although significant, added minimal value to the model beyond the variance accounted for by the SRT Delayed Recall. Both variables emerged as significant predictors of side of seizure focus when entered into separate regressions. Sensitivity and specificity of the SRT and BNT ranged from 56% to 65%. The WMS Logical Memory and nonverbal memory measures were not significant predictors of the side of seizure focus.

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Control of the angular distribution of the radiation emitted by phase-locked laser arrays

NASA Astrophysics Data System (ADS)

Kachurin, O. R.; Lebedev, F. V.; Napartovich, M. A.; Khlynov, M. E.

1991-03-01

A numerical investigation was made of the influence of the number and packing density of a linear array of periodically arranged coherent sources on the efficiency of redistributing the radiation power from the side lobes to the main lobe of the angular distribution of the emitted radiation by using a binary phase corrector mounted in the image-doubling plane. The results are given of experimental investigations of a new device for improving the radiation pattern of phase-locked laser arrays.

Postoperative recovery of hippocampal contralateral diffusivity in medial temporal lobe epilepsy.

PubMed

Thivard, Lionel; Tanguy, Marie-Laure; Adam, Claude; Clémenceau, Stéphane; Dezamis, Edouard; Lehéricy, Stéphane; Dormont, Didier; Chiras, Jacques; Baulac, Michel; Dupont, Sophie

2007-03-01

To search for a recovery after surgery of mean diffusivity (MD) values in the contralateral nonsclerotic hippocampus of patients with medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). Twenty-four MTLE patients (12 right-sided and 12 left-sided MTLE) and 36 healthy volunteers were investigated using diffusion tensor imaging. A region-of-interest approach was used to measure pre- and postoperative interictal hippocampal MD values in patients. Diffusion abnormalities in contralateral nonsclerotic hippocampus recovered after surgery (p<0.0001). A subgroup of 14 patients exhibited a clear increase in MD values whereas the remaining 10 patients were stable. No significant difference was found between the two subgroups for each of the electroclinical data studied including early postoperative outcome, all patients being either seizure free or with rare persistent auras. This finding suggests that diffusion abnormalities in contralateral hippocampus may represent a functional mechanism linked to the active epileptic process.

An airport wind shear detection and warning system using Doppler radar: A feasibility study

NASA Technical Reports Server (NTRS)

Mccarthy, J.; Blick, E. F.; Elmore, K. L.

1981-01-01

A feasibility study was conducted to determine whether ground based Doppler radar could measure the wind along the path of an approaching aircraft with sufficient accuracy to predict aircraft performance. Forty-three PAR approaches were conducted, with 16 examined in detail. In each, Doppler derived longitudinal winds were compared to aircraft measured winds; in approximately 75 percent of the cases, the Doppler and aircraft winds were in acceptable agreement. In the remaining cases, errors may have been due to a lack of Doppler resolution, a lack of co-location of the two sampling volumes, the presence of eddy or vortex like disturbances within the pulse volume, or the presence of point targets in antenna side lobes. It was further concluded that shrouding techniques would have reduced the side lobe problem. A ground based Doppler radar operating in the optically clear air, provides the appropriate longitudinal winds along an aircraft's intended flight path.

Nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating embedded in water

NASA Astrophysics Data System (ADS)

Jiménez, N.; Romero-García, V.; Picó, R.; Garcia-Raffi, L. M.; Staliunas, K.

2015-11-01

We report the nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating immersed in water. In the linear regime, the system presents high focal gain (32 dB), with a narrow beam-width and intense side lobes as it is common in focusing by Fresnel-like lenses. Activating the nonlinearity of the host medium by using high amplitude incident waves, the focusing properties of the lens dramatically change. Theoretical predictions show that the focal gain of the system extraordinary increases in the strongly nonlinear regime (Mach number of 6.1 × 10-4). Particularly, the harmonic generation is locally activated at the focal spot, and the second harmonic beam is characterized by strongly reduced side-lobes and an excellent beam profile as experiments show in agreement with theory. The results can motivate applications in medical therapy or second harmonic imaging.

Interictal 18FDG PET findings in temporal lobe epilepsy with déjà vu.

PubMed

Adachi, N; Koutroumanidis, M; Elwes, R D; Polkey, C E; Binnie, C D; Reynolds, E H; Barrington, S F; Maisey, M N; Panayiotopoulos, C P

1999-01-01

The authors studied the functional anatomy of the déjà vu (DV) experience in nonlesional temporal lobe epilepsy (TLE), using interictal fluorine-18 fluorodeoxyglucose PET in 14 patients with and 17 patients without DV. Several clinical conditions, such as age at PET study, side of ictal onset zone, and dominance for language, were no different between the two groups. The patients with DV showed significant relative reductions in glucose metabolism in the mesial temporal structures and the parietal cortex. The findings demonstrate that ictal DV is of no lateralizing value. They further suggest that temporal lobe dysfunction is necessary but not sufficient for the generation of DV. Extensive association cortical areas may be involved as part of the network that integrates this distinct experience.

Imbalance of community structures in epilepsy

NASA Astrophysics Data System (ADS)

Ortega, G. J.; Herrera Peco, I.; García de Sola, R.; Pastor, J.

2010-09-01

Epilepsy is commonly associated with synchronous activity in the form of spikes and also in developed seizures. Desynchronised activity seems to play an important role also in the seizure process, favouring the initiation of seizures. The aim of the present work is to explore synchronization activity in the inner areas in the temporal lobe of epileptic patients by a novel approach. Two temporal lobe epilepsy (TLE) patients' records have been analyzed through a cluster analysis. Electrical activity in the inner part of the temporal has been recorded by using Foramen Ovale Electrodes (FOE), a semi-invasive technique frequently used in drug resistant epileptic patients. Instead of tracking synchronized activity, we give here special attention to desynchronized activity, mainly those areas which are not included in synchronization clusters. Our results show that electrical activity in the epileptic side behaves in a less cohesive fashion than the contra-lateral side. There exists a clear tendency in the epileptic side to be organized as isolated clusters of electrical activity as compared with the contra-lateral side, which is organized in the form of large clusters of synchronous activity. In particular, we shall give special attention to the cluster desynchronization during the seizures. As we shall show, our results can help in understand several characteristics of the seizures dynamics.

Collateral brain damage, a potential source of cognitive impairment after selective surgery for control of mesial temporal lobe epilepsy.

PubMed

Helmstaedter, C; Van Roost, D; Clusmann, H; Urbach, H; Elger, C E; Schramm, J

2004-02-01

Highly selective epilepsy surgery in temporal lobe epilepsy is intended to achieve seizure freedom at a lower cognitive risk than standard en bloc resections, but bears the risk of collateral cortical damage resulting from the surgical approach. To investigate cortical damage associated with selective amygdalo-hippocampectomy (SAH). 34 epileptic patients were evaluated. They were randomly assigned to SAH using either a sylvian (9 left/10 right) or a transcortical surgical approach (5 left/10 right). Postoperative MRI signal intensity changes adjacent to the approach were correlated with performance changes in serial word and design list learning. Losses in verbal learning and recognition memory were positively related to signal intensity changes, independent of the side of the resection, the surgical approach, or the extent of the mesial resection. Losses in consolidation/retrieval (memory) were greater after left sided surgery. Losses in design learning were related to right sided surgery and signal intensity changes. Seizure outcome (85% seizure-free) did not differ depending on the side or type of surgery. Collateral damage to cortical tissues adjacent to the surgical approach contributes to postoperative verbal and figural memory outcome after SAH. Controlling for collateral damage may clarify the controversial memory outcomes after SAH reported by different surgical centres.

Super-resolution Doppler beam sharpening method using fast iterative adaptive approach-based spectral estimation

NASA Astrophysics Data System (ADS)

Mao, Deqing; Zhang, Yin; Zhang, Yongchao; Huang, Yulin; Yang, Jianyu

2018-01-01

Doppler beam sharpening (DBS) is a critical technology for airborne radar ground mapping in forward-squint region. In conventional DBS technology, the narrow-band Doppler filter groups formed by fast Fourier transform (FFT) method suffer from low spectral resolution and high side lobe levels. The iterative adaptive approach (IAA), based on the weighted least squares (WLS), is applied to the DBS imaging applications, forming narrower Doppler filter groups than the FFT with lower side lobe levels. Regrettably, the IAA is iterative, and requires matrix multiplication and inverse operation when forming the covariance matrix, its inverse and traversing the WLS estimate for each sampling point, resulting in a notably high computational complexity for cubic time. We propose a fast IAA (FIAA)-based super-resolution DBS imaging method, taking advantage of the rich matrix structures of the classical narrow-band filtering. First, we formulate the covariance matrix via the FFT instead of the conventional matrix multiplication operation, based on the typical Fourier structure of the steering matrix. Then, by exploiting the Gohberg-Semencul representation, the inverse of the Toeplitz covariance matrix is computed by the celebrated Levinson-Durbin (LD) and Toeplitz-vector algorithm. Finally, the FFT and fast Toeplitz-vector algorithm are further used to traverse the WLS estimates based on the data-dependent trigonometric polynomials. The method uses the Hermitian feature of the echo autocorrelation matrix R to achieve its fast solution and uses the Toeplitz structure of R to realize its fast inversion. The proposed method enjoys a lower computational complexity without performance loss compared with the conventional IAA-based super-resolution DBS imaging method. The results based on simulations and measured data verify the imaging performance and the operational efficiency.

Characteristic measurement for femtosecond laser pulses using a GaAs PIN photodiode as a two-photon photovoltaic receiver

NASA Astrophysics Data System (ADS)

Chen, Junbao; Xia, Wei; Wang, Ming

2017-06-01

Photodiodes that exhibit a two-photon absorption effect within the spectral communication band region can be useful for building an ultra-compact autocorrelator for the characteristic inspection of optical pulses. In this work, we develop an autocorrelator for measuring the temporal profile of pulses at 1550 nm from an erbium-doped fiber laser based on the two-photon photovoltaic (TPP) effect in a GaAs PIN photodiode. The temporal envelope of the autocorrelation function contains two symmetrical temporal side lobes due to the third order dispersion of the laser pulses. Moreover, the joint time-frequency distribution of the dispersive pulses and the dissimilar two-photon response spectrum of GaAs and Si result in different delays for the appearance of the temporal side lobes. Compared with Si, GaAs displays a greater sensitivity for pulse shape reconstruction at 1550 nm, benefiting from the higher signal-to-noise ratio of the side lobes and the more centralized waveform of the autocorrelation trace. We also measure the pulse width using the GaAs PIN photodiode, and the resolution of the measured full width at half maximum of the TPP autocorrelation trace is 0.89 fs, which is consistent with a conventional second-harmonic generation crystal autocorrelator. The GaAs PIN photodiode is shown to be highly suitable for real-time second-order autocorrelation measurements of femtosecond optical pulses. It is used both for the generation and detection of the autocorrelation signal, allowing the construction of a compact and inexpensive intensity autocorrelator.

Nonlinear pulse compression in pulse-inversion fundamental imaging.

PubMed

Cheng, Yun-Chien; Shen, Che-Chou; Li, Pai-Chi

2007-04-01

Coded excitation can be applied in ultrasound contrast agent imaging to enhance the signal-to-noise ratio with minimal destruction of the microbubbles. Although the axial resolution is usually compromised by the requirement for a long coded transmit waveforms, this can be restored by using a compression filter to compress the received echo. However, nonlinear responses from microbubbles may cause difficulties in pulse compression and result in severe range side-lobe artifacts, particularly in pulse-inversion-based (PI) fundamental imaging. The efficacy of pulse compression in nonlinear contrast imaging was evaluated by investigating several factors relevant to PI fundamental generation using both in-vitro experiments and simulations. The results indicate that the acoustic pressure and the bubble size can alter the nonlinear characteristics of microbubbles and change the performance of the compression filter. When nonlinear responses from contrast agents are enhanced by using a higher acoustic pressure or when more microbubbles are near the resonance size of the transmit frequency, higher range side lobes are produced in both linear imaging and PI fundamental imaging. On the other hand, contrast detection in PI fundamental imaging significantly depends on the magnitude of the nonlinear responses of the bubbles and thus the resultant contrast-to-tissue ratio (CTR) still increases with acoustic pressure and the nonlinear resonance of microbubbles. It should be noted, however, that the CTR in PI fundamental imaging after compression is consistently lower than that before compression due to obvious side-lobe artifacts. Therefore, the use of coded excitation is not beneficial in PI fundamental contrast detection.

2-D Ultrasound Sparse Arrays Multidepth Radiation Optimization Using Simulated Annealing and Spiral-Array Inspired Energy Functions.

PubMed

Roux, Emmanuel; Ramalli, Alessandro; Tortoli, Piero; Cachard, Christian; Robini, Marc C; Liebgott, Herve

2016-12-01

Full matrix arrays are excellent tools for 3-D ultrasound imaging, but the required number of active elements is too high to be individually controlled by an equal number of scanner channels. The number of active elements is significantly reduced by the sparse array techniques, but the position of the remaining elements must be carefully optimized. This issue is faced here by introducing novel energy functions in the simulated annealing (SA) algorithm. At each iteration step of the optimization process, one element is freely translated and the associated radiated pattern is simulated. To control the pressure field behavior at multiple depths, three energy functions inspired by the pressure field radiated by a Blackman-tapered spiral array are introduced. Such energy functions aim at limiting the main lobe width while lowering the side lobe and grating lobe levels at multiple depths. Numerical optimization results illustrate the influence of the number of iterations, pressure measurement points, and depths, as well as the influence of the energy function definition on the optimized layout. It is also shown that performance close to or even better than the one provided by a spiral array, here assumed as reference, may be obtained. The finite-time convergence properties of SA allow the duration of the optimization process to be set in advance.

A Novel Functional Magnetic Resonance Imaging Paradigm for the Preoperative Assessment of Auditory Perception in a Musician Undergoing Temporal Lobe Surgery.

PubMed

Hale, Matthew D; Zaman, Arshad; Morrall, Matthew C H J; Chumas, Paul; Maguire, Melissa J

2018-03-01

Presurgical evaluation for temporal lobe epilepsy routinely assesses speech and memory lateralization and anatomic localization of the motor and visual areas but not baseline musical processing. This is paramount in a musician. Although validated tools exist to assess musical ability, there are no reported functional magnetic resonance imaging (fMRI) paradigms to assess musical processing. We examined the utility of a novel fMRI paradigm in an 18-year-old left-handed pianist who underwent surgery for a left temporal low-grade ganglioglioma. Preoperative evaluation consisted of neuropsychological evaluation, T1-weighted and T2-weighted magnetic resonance imaging, and fMRI. Auditory blood oxygen level-dependent fMRI was performed using a dedicated auditory scanning sequence. Three separate auditory investigations were conducted: listening to, humming, and thinking about a musical piece. All auditory fMRI paradigms activated the primary auditory cortex with varying degrees of auditory lateralization. Thinking about the piece additionally activated the primary visual cortices (bilaterally) and right dorsolateral prefrontal cortex. Humming demonstrated left-sided predominance of auditory cortex activation with activity observed in close proximity to the tumor. This study demonstrated an fMRI paradigm for evaluating musical processing that could form part of preoperative assessment for patients undergoing temporal lobe surgery for epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.

One declarative memory system or two? The relationship between episodic and semantic memory in children with temporal lobe epilepsy.

PubMed

Smith, Mary Lou; Lah, Suncica

2011-09-01

This study explored verbal semantic and episodic memory in children with unilateral temporal lobe epilepsy to determine whether they had impairments in both or only 1 aspect of memory, and to examine relations between performance in the 2 domains. Sixty-six children and adolescents (37 with seizures of left temporal lobe onset, 29 with right-sided onset) were given 4 tasks assessing different aspects of semantic memory (picture naming, fluency, knowledge of facts, knowledge of word meanings) and 2 episodic memory tasks (story recall, word list recall). High rates of impairments were observed across tasks, and no differences were found related to the laterality of the seizures. Individual patient analyses showed that there was a double dissociation between the 2 aspects of memory in that some children were impaired on episodic but not semantic memory, whereas others showed intact episodic but impaired semantic memory. This double dissociation suggests that these 2 memory systems may develop independently in the context of temporal lobe pathology, perhaps related to differential effects of dysfunction in the lateral and mesial temporal lobe structures. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Temporal lobe epilepsy: analysis of patients with dual pathology.

PubMed

Salanova, V; Markand, O; Worth, R

2004-02-01

To determine the frequency and types of dual pathology in patients with temporal lobe epilepsy (TLE) and to analyze the clinical manifestations and surgical outcome. A total of 240 patients with TLE underwent temporal resections following a comprehensive pre-surgical evaluation. Thirty-seven (15.4%) of these had hippocampal sclerosis (HS) or temporal lobe gliosis in association with another lesion (dual pathology). Eighteen of 37 patients with dual pathology had heterotopia of the temporal lobe, nine had cortical dysplasia, four had cavernous angiomas or arteriovenous malformations, one had a dysembryoplastic neuroepithelial tumor, one had a contusion and four patients had cerebral infarctions in childhood. 68.5% had abnormal head magnetic resonance imagings, 91.3% had abnormal positron emission tomography scans, and 96% had abnormal ictal SPECT. The intracarotid amobarbital procedure (IAP) showed impaired memory of the epileptogenic side in 72% of the patients. Twenty patients had left and 17 had right-sided en bloc temporal resections, including the lesion and mesial temporal structures. Twenty-six (70.2%) became seizure-free, eight (21.6%) had rare seizures, two (5.4%) had worthwhile seizure reduction and one (2.7%) had no improvement (range of follow-up 1-16 years, mean = 7.4 years). 15.4% had dual pathology. The dual pathology was almost exclusively seen in patients whose lesions were congenital, or occurred early in life, suggesting that the hippocampus is more vulnerable and more readily develops HS in early childhood. Resections, including the lateral and mesial temporal structures led to a favorable outcome with no mortality and little morbidity.

Olfactory Groove Meningiomas: Comparison of Extent of Frontal Lobe Changes After Lateral and Bifrontal Approaches.

PubMed

Nanda, Anil; Maiti, Tanmoy K; Bir, Shyamal C; Konar, Subhas K; Guthikonda, Bharat

2016-10-01

Olfactory groove meningiomas often are behaviorally silent. Numerous surgical approaches have been described in the literature for the successful removal of these meningiomas. Lateral (pterional/frontolateral) and anterior (bifrontal/fronto-orbito-basal) approaches with their various modifications remain the 2 major corridors in resecting them. In this study, we discuss our experience in microsurgical treatment of these tumors at our institution and assess the extent of frontal lobe damage after the resection of tumor. We reviewed the medical records of patients who underwent surgical excision of olfactory groove meningiomas from 1990 to 2014. To measure the extent of frontal lobe damage via lateral and anterior approaches, we measured the volume of porencephalic cave in the postoperative magnetic resonance imaging by using Brainlab software. The ratio of volume of porencephalic cave to tumor was measured between 2 sides and 2 approaches. Fifty-seven patients with olfactory groove meningiomas, who underwent 62 microsurgical resection procedures in 1990-2014 were included in the study (74% were more than 5 cm at presentation). Pterional and bifrontal craniotomies were the most commonly used approaches. At follow-up, the volume of porencephalic cave after lateral approach was significantly less in the side contralateral to craniotomy irrespective of tumor size. The difference between ratio of volume of porencephalic cave and initial tumor was significantly less after lateral approaches, when compared to anterior approaches. Lateral approaches (pterional/frontolateral) resulted in less frontal lobe change and better olfactory preservation in comparison to anterior approaches in present series. Published by Elsevier Inc.

Three-Dimensional Anatomy of the White Matter Fibers of the Temporal Lobe: Surgical Implications.

PubMed

Pescatori, Lorenzo; Tropeano, Maria Pia; Manfreda, Andrea; Delfini, Roberto; Santoro, Antonio

2017-04-01

The aim of this work is to describe in detail the complex 3-dimensional organization of the white matter of the temporal lobe and discuss the surgical implications of the approaches to lesions located into the mesial temporal region and within the temporal horn and the atrium of the lateral ventricles. Sixteen human cerebral hemispheres fixed in a 10% formalin solution for at least 40 days were studied. After removal of the arachnoid membrane, the hemispheres were frozen at -15°C for at least 14 days, and the Klingler technique, which consists of the microscopic dissection and progressive identification of white matter fibers, was performed. The dissection allowed us to appreciate the topographical organization of the white matter of the temporal lobe identifying the most important association, projection, and commissural fasciculi. The dissection from the lateral side allowed the progressive visualization of the superior longitudinal fasciculus and its components, the extreme and external capsule, the uncinate fasciculus, the inferior fronto-occipital fasciculus, the anterior commissure, the internal capsule, and the optic radiations. The dissection was completed from the inferior and medial side for identification of the cingulum and the fornix. The complex 3-dimensional organization of the white matter substance of the temporal lobe is characterized by 2 main systems of boundaries: the sagittal stratum and the temporal stem. Their knowledge is essential for the appropriate treatment of pathologies localized in this region as demonstrated by the 2 clinical cases presented in this work. Copyright © 2017 Elsevier Inc. All rights reserved.

Decreased functional connectivity and structural deficit in alertness network with right-sided temporal lobe epilepsy.

PubMed

Gao, Yujun; Zheng, Jinou; Li, Yaping; Guo, Danni; Wang, Mingli; Cui, Xiangxiang; Ye, Wei

2018-04-01

Patients with temporal lobe epilepsy (TLE) often suffer from alertness alterations. However, specific regions connected with alertness remain controversial, and whether these regions have structural impairment is also elusive. This study aimed to investigate the characteristics and neural mechanisms underlying the functions and structures of alertness network in patients with right-sided temporal lobe epilepsy (rTLE) by performing the attentional network test (ANT), resting-state functional magnetic resonance imaging (R-SfMRI), and diffusion tensor imaging (DTI).A total of 47 patients with rTLE and 34 healthy controls underwent ANT, R-SfMRI, and DTI scan. The seed-based functional connectivity (FC) method and deterministic tractography were used to analyze the data.Patients with rTLE had longer reaction times in the no-cue and double-cue conditions. However, no differences were noted in the alertness effect between the 2 groups. The patient group had lower FC compared with the control group in the right inferior parietal lobe (IPL), amygdala, and insula. Structural deficits were found in the right parahippocampal gyrus, superior temporal pole, insula, and amygdala in the patient group compared with the control group. Also significantly negative correlations were observed between abnormal fractional anisotropy (between the right insula and the superior temporal pole) and illness duration in the patients with rTLE.The findings of this study suggested abnormal intrinsic and phasic alertness, decreased FC, and structural deficits within the alerting network in the rTLE. This study provided new insights into the mechanisms of alertness alterations in rTLE.

A diffusional kurtosis imaging study of idiopathic generalized epilepsy with unilateral interictal epileptiform discharges in children.

PubMed

Zhang, Yuzhen; Gao, Yu; Zhou, Minxiong; Wu, Jie; Zee, Chishing; Wang, Dengbin

2016-10-01

To investigate brain abnormalities in children with a clinical diagnosis of idiopathic generalized epilepsy (IGE) and unilateral interictal epileptiform discharges (IED) demonstrated on electroencephalography (EEG) by diffusional kurtosis imaging (DKI). DKI images were obtained from 18 patients (n=9 each in the left and right hemispheres). Fractional anisotropy (FA), mean diffusivity (MD), and mean kurtosis (MK) maps were estimated through voxel-based analyses, and compared with 18 normal controls matched for age and sex. In the left side group, the significant differences of FA were in the left fusiform gyrus and occipital lobe of the white matter (WM). The significant differences of MD were in the left pons. The significant differences of MK were in the anterior cingulate gyrus, limbic lobe, gray matter (GM) and WM of the right cerebrum. In the right side group, the significant differences of FA were in the WM of the left cerebrum. MD identified differences in the frontal, temporal, occipital, and parietal lobes of both hemispheres, especially in the limbic system, fusiform gyrus, uncus, and parahippocampal gyrus. The significant differences of MK were in the GM of the right cerebrum, particularly in the rolandic operculum and frontal lobe. DKI is sensitive for the detection of diffusion abnormalities in both WM and GM of IGE in children. Secondary brain abnormalities may exist in regions outside the unilateral epileptogenic zone through the limbic epileptic network, and can be detected by DKI indices FA, MD and MK. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Use of an optokinetic chart stimulation intervention for restoration of voluntary movement, postural control and mobility in acute stroke patients and one post intensive care polyneuropathy patient: A case series.

PubMed

Chitambira, Benjamin

2011-01-01

The objective of this case series is to report on the use of an optokinetic chart stimulation intervention to restore voluntary movement, postural control and mobility in acute stroke patients and one post intensive care polyneuropathy patient. An optokinetic chart was moved in front of the patient: from side to side, up and down and finally forwards and backwards. Specific active-assisted exercises of affected shoulder anti-gravity muscles were also carried out. Except for strokes involving basal ganglia, parietal and temporal lobes simultaneously, optokinetic stimulation was effective in restoring voluntary movements, postural control and mobility. In single lobe strokes and those that do not involve simultaneous extensive damage to the basal ganglia, parietal and temporal lobes optokinetics may be one of the neuro-modulation techniques that use cranial nerve circuits of key movement and postural control input organs to enhance neural plasticity. Extensive temporal- parietal strokes may need longer periods of rehabilitation. Further research using a combination of vestibular interventions may provide an effective intervention for severely disabling extensive temporal-parietal strokes. Further studies with this optokinetic chart intervention are also recommended for chronic stroke patients.

Anatomy of the Temporal Lobe

PubMed Central

Kiernan, J. A.

2012-01-01

Only primates have temporal lobes, which are largest in man, accommodating 17% of the cerebral cortex and including areas with auditory, olfactory, vestibular, visual and linguistic functions. The hippocampal formation, on the medial side of the lobe, includes the parahippocampal gyrus, subiculum, hippocampus, dentate gyrus, and associated white matter, notably the fimbria, whose fibres continue into the fornix. The hippocampus is an inrolled gyrus that bulges into the temporal horn of the lateral ventricle. Association fibres connect all parts of the cerebral cortex with the parahippocampal gyrus and subiculum, which in turn project to the dentate gyrus. The largest efferent projection of the subiculum and hippocampus is through the fornix to the hypothalamus. The choroid fissure, alongside the fimbria, separates the temporal lobe from the optic tract, hypothalamus and midbrain. The amygdala comprises several nuclei on the medial aspect of the temporal lobe, mostly anterior the hippocampus and indenting the tip of the temporal horn. The amygdala receives input from the olfactory bulb and from association cortex for other modalities of sensation. Its major projections are to the septal area and prefrontal cortex, mediating emotional responses to sensory stimuli. The temporal lobe contains much subcortical white matter, with such named bundles as the anterior commissure, arcuate fasciculus, inferior longitudinal fasciculus and uncinate fasciculus, and Meyer's loop of the geniculocalcarine tract. This article also reviews arterial supply, venous drainage, and anatomical relations of the temporal lobe to adjacent intracranial and tympanic structures. PMID:22934160

Seismic responses and controlling factors of Miocene deepwater gravity-flow deposits in Block A, Lower Congo Basin

NASA Astrophysics Data System (ADS)

Wang, Linlin; Wang, Zhenqi; Yu, Shui; Ngia, Ngong Roger

2016-08-01

The Miocene deepwater gravity-flow sedimentary system in Block A of the southwestern part of the Lower Congo Basin was identified and interpreted using high-resolution 3-D seismic, drilling and logging data to reveal development characteristics and main controlling factors. Five types of deepwater gravity-flow sedimentary units have been identified in the Miocene section of Block A, including mass transport, deepwater channel, levee, abandoned channel and sedimentary lobe deposits. Each type of sedimentary unit has distinct external features, internal structures and lateral characteristics in seismic profiles. Mass transport deposits (MTDs) in particular correspond to chaotic low-amplitude reflections in contact with mutants on both sides. The cross section of deepwater channel deposits in the seismic profile is in U- or V-shape. The channel deposits change in ascending order from low-amplitude, poor-continuity, chaotic filling reflections at the bottom, to high-amplitude, moderate to poor continuity, chaotic or sub-parallel reflections in the middle section and to moderate-weak amplitude, good continuity, parallel or sub-parallel reflections in the upper section. The sedimentary lobes are laterally lobate, which corresponds to high-amplitude, good-continuity, moundy reflection signatures in the seismic profile. Due to sediment flux, faults, and inherited terrain, few mass transport deposits occur in the northeastern part of the study area. The front of MTDs is mainly composed of channel-levee complex deposits, while abandoned-channel and lobe-deposits are usually developed in high-curvature channel sections and the channel terminals, respectively. The distribution of deepwater channel, levee, abandoned channel and sedimentary lobe deposits is predominantly controlled by relative sea level fluctuations and to a lesser extent by tectonism and inherited terrain.

Optical antenna gain. III - The effect of secondary element support struts on transmitter gain

NASA Technical Reports Server (NTRS)

Klein, B. J.; Degnan, J. J.

1976-01-01

The effect of a secondary-element spider support structure on optical antenna transmitter gain is analyzed. An expression describing the influence of the struts on the axial gain, in both the near and far fields, is derived as a function of the number of struts and their width. It is found that, for typical systems, the struts degrade the on-axis gain by less than 0.4 dB, and the first side-lobe level is not increased significantly. Contour plots have also been included to show the symmetry of the far-field distributions for three- and four-support members.

Are the dimensions of submarine lobe systems independent of allogenic factors?

NASA Astrophysics Data System (ADS)

Prélat, A.; Covault, J. A.; Hodgson, D. M.; Fildani, A.; Flint, S. S.

2010-05-01

Submarine lobe dimensions from six different systems are compared: 1) the exhumed Permian Fan 3 lobe complex of the Tanqua Karoo, South Africa; 2) the modern Amazon fan channel-mouth lobe complex, offshore Brazil; 3) a portion of the modern distal Zaïre fan, offshore Angola / Congo; 4) a Pleistocene fan of the Kutai Basin, subsurface offshore Indonesia; 5) the modern Golo system, offshore east Corsica, France; and 6) a lobe complex deposited in the shallow subsurface, offshore Nigeria. These six systems have significantly different source-to-sink configurations (shelf dimension and slope topography), sediment supply characteristics (calibre and rate), tectonic settings, (palaeo) latitude, and delivery systems. Despite these differences, the lobe deposits share similar geometric and dimensional characteristics. Lobes are grouped into two distinct populations of geometries that can be related to basin-floor topography. The first population corresponds to areally extensive but thin lobes (average width 14 km × length 35 km × thickness 12 m) that were deposited onto low relief basin floor areas, like the Tanqua Karoo, the Amazon and the Zaïre systems. The second population corresponds to areally smaller but thicker lobes (average width 5 km × length 8 km × thickness 30 m) that were deposited into settings with higher amplitude of relief, like in the Corsican trough, the Kutai basin, and offshore Nigeria. Basin floor topography confining the lobes can be very subtle, and only occur on one side of the system. The two populations of lobe types, however, share similar volumes, in the order of 1 or 2 km3. The largest lobes are observed in the Zaïre fan, where the average lobe volume reaches 3.3 km3 and the smallest lobes are observed in the Corsican trough where the average lobe volume is 0.4 km3. This variation in lobe volume is minor when compared to the variation observed in present-day up-dip drainage systems, which provide sediment to the deep-water depositional systems and their lobes. This suggests that there is a limit to the total volume of sediment that individual lobes can reach before they shift to a new locus of deposition. In otherwords, big systems do not build big lobes, rather more lobes per unit time. Indeed, in the Amazon and the Zaïre systems, lobe life span is estimated to be 600 and 1450 years, respectively, whereas in the Corsican Golo system, lobe life span is ~ 10 times longer, around 10 to 14 × 103 years. A fundamental control on lobe volume is the propensity for flows to find the lowest topography. We postulate that a fundamental control on all distributive systems is the ratio of lobe thickness to feeder channel depth. The surface gradient from the feeder channel base and lobe top will tend to reduce through time as a lobe builds. This is not sustainable, and when a steeper lateral gradient is present a new depositional low will be used for flows to fill.

Brain biochemical correlates of the plasma homocysteine level: a proton magnetic resonance spectroscopy study in the elderly subjects.

PubMed

Chen, Cheng-Sheng; Kuo, Yu-Ting; Tsai, Hui-Yi; Li, Chun-Wei; Lee, Chen-Chang; Yen, Cheng-Fang; Lin, Hsiu-Fen; Ko, Chih-Hung; Juo, Suh-Hang Hank; Yeh, Yi-Chun; Liu, Gin-Chung

2011-07-01

An elevated plasma homocysteine level has been reported to be associated with various neuropsychiatric diseases. However, little is known about the brain biochemical changes associated with the higher plasma homocysteine level. The main goal of this study was to examine the sex difference in brain biochemical concentrations using brain proton magnetic resonance spectroscopy (H MRS), and to elucidate the biochemical changes associated with plasma homocysteine levels by sex in healthy elderly subjects. Seventy elderly subjects without any clinical psychiatric and neurological disease underwent 3-T brain H MRS. MRS spectra were acquired from voxels placed on the left side of the basal ganglia, frontal lobe, and hippocampus. Brain biochemical concentrations were compared between the elderly male and female participants. Correlations between these biochemical concentrations and plasma homocysteine levels by sex were analyzed. Female participants had significantly higher levels of choline in the left frontal lobe and hippocampus, and lower creatine and myo-inositol, in the left basal ganglia than did males. A higher homocysteine level was correlated with a lower N-acetylaspartate (NAA) concentration in the left hippocampus in elderly women (r = -0.44; p = 0.03) but not in elderly men. This study found that there was a sex difference in brain biochemical concentrations in the elderly participants. A higher plasma homocysteine level was associated with a lower NAA in the hippocampus of elderly women. The sex difference in association between brain biochemical concentrations and plasma homocysteine levels needs further investigation. We speculate that after menopause, women lose protection of estrogen from the neurotoxic effects of homocysteine in the hippocampus. Future studies are required to examine this speculation.

Cardiopulmonary complications during pediatric seizures: A prelude to understanding SUDEP

PubMed Central

Singh, Kanwaljit; Katz, Eliot S.; Zarowski, Marcin; Loddenkemper, Tobias; Llewellyn, Nichelle; Manganaro, Sheryl; Gregas, Matt; Pavlova, Milena; Kothare, Sanjeev V.

2017-01-01

Summary Purpose Sudden unexpected death in epilepsy (SUDEP) is an important, unexplained cause of death in epilepsy. Role of cardiopulmonary abnormalities in the pathophysiology of SUDEP is unclear in the pediatric population. Our objective was to assess cardiopulmonary abnormalities during epileptic seizures in children, with the long-term goal of identifying potential mechanisms of SUDEP. Methods We prospectively recorded cardiopulmonary functions using pulse-oximetry, electrocardiography (ECG), and respiratory inductance plethysmography (RIP). Logistic regression was used to evaluate association of cardiorespiratory findings with seizure characteristics and demographics. Key Findings We recorded 101 seizures in 26 children (average age 3.9 years). RIP provided analyzable data in 78% and pulse-oximetry in 63% seizures. Ictal central apnea was more prevalent in patients with younger age (p = 0.01), temporal lobe (p < 0.001), left-sided (p < 0.01), symptomatic generalized (p = 0.01), longer duration seizures (p < 0.0002), desaturation (p < 0.0001), ictal bradycardia (p < 0.05), and more antiepileptic drugs (AEDs; p < 0.01), and was less prevalent in frontal lobe seizures (p < 0.01). Ictal bradypnea was more prevalent in left-sided (p < 0.05), symptomatic generalized seizures (p < 0.01), and in brain magnetic resonance imaging (MRI) lesions (p < 0.1). Ictal tachypnea was more prevalent in older-age (p = 0.01), female gender (p = 0.05), frontal lobe (p < 0.05), right-sided seizures (p < 0.001), fewer AEDs (p < 0.01), and less prevalent in lesional (p < 0.05) and symptomatic generalized seizures (p < 0.05). Ictal bradycardia was more prevalent in male patients (p < 0.05) longer duration seizures (p < 0.05), desaturation (p = 0.001), and more AEDs (p < 0.05), and was less prevalent in frontal lobe seizures (p = 0.01). Ictal and postictal bradycardia were directly associated (p < 0.05). Desaturation was more prevalent in longer-duration seizures (p < 0.0001), ictal apnea (p < 0.0001), ictal bradycardia (p = 0.001), and more AEDs (p = 0.001). Significance Potentially life-threatening cardiopulmonary abnormalities such as bradycardia, apnea, and hypoxemia in pediatric epileptic seizures are associated with predictable patient and seizure characteristics, including seizure subtype and duration. PMID:23731396

An asymmetric jet-launching model for the protoplanetary nebula CRL 618

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

Velázquez, Pablo F.; Raga, Alejandro C.; Toledo-Roy, Juan C.

We propose an asymmetrical jet-ejection mechanism in order to model the mirror symmetry observed in the lobe distribution of some protoplanetary nebulae (pPNs), such as the pPN CRL 618. Three-dimensional hydrodynamical simulations of a precessing jet launched from an orbiting source were carried out, including an alternation in the ejections of the two outflow lobes, depending on which side of the precessing accretion disk is hit by the accretion column from a Roche lobe-filling binary companion. Both synthetic optical emission maps and position-velocity diagrams were obtained from the numerical results with the purpose of carrying out a direct comparison withmore » observations. Depending on the observer's point of view, multipolar morphologies are obtained that exhibit a mirror symmetry at large distances from the central source. The obtained lobe sizes and their spatial distributions are in good agreement with the observed morphology of the pPN CRL 618. We also obtain that the kinematic ages of the fingers are similar to those obtained in the observations.« less

Increase in left liver lobe function after preoperative right portal vein embolisation assessed with gadolinium-EOB-DTPA MRI.

PubMed

Geisel, Dominik; Lüdemann, Lutz; Keuchel, Thomas; Malinowski, Maciej; Seehofer, Daniel; Stockmann, Martin; Hamm, Bernd; Gebauer, Bernhard; Denecke, Timm

2013-09-01

To prospectively evaluate the early development of regional liver function after right portal vein embolisation (PVE) with Gd-EOB-DTPA-enhanced MRI in patients scheduled for extended right hemihepatectomy. Ten patients who received a PVE before an extended hemihepatectomy were examined before and 14 days after PVE using Gd-EOB-DTPA-enhanced MRI of the liver. In these sequences representative region of interest measurements were performed in the embolised right (RLL) and the non-embolised left liver lobe (LLL). The volume as well as hepatic uptake index (HUI) was calculated independently for each lobe. Relative enhancement 14 days after PVE decreased in the RLL and increased significantly in the LLL (P < 0.05). Average hepatic uptake index (HUI) for RLL was significantly lower 14 days after PVE than before PVE (P < 0.05) and significantly higher for LLL (P < 0.05). A significant shift of contrast uptake from the right to the left liver lobe can be depicted as early as 14 days after right PVE by using Gd-EOB-DTPA-enhanced MRI, which could reflect the redirected portal venous blood flow and the rapid utilisation of a hepatic functional reserve. • Preoperative portal vein embolisation (PVE) is widely performed before right-sided hepatic resection. • PVE increases intravenous contrast medium uptake in the left lobe of liver. • The hepatic uptake index for the left liver lobe increases rapidly after PVE. • Left liver lobe function increase may be visualised by Gd-EOB-DTPA-enhanced MRI.

Surgical techniques in radiation induced temporal lobe necrosis in nasopharyngeal carcinoma patients.

PubMed

Alfotih, Gobran Taha Ahmed; Zheng, Mei Guang; Cai, Wang Qing; Xu, Xin Ke; Hu, Zhen; Li, Fang Cheng

2016-01-01

Radiation induced brain injury ranges from acute reversible edema to late, irreversible radiation necrosis. Radiation induced temporal lobe necrosis is associated with permanent neurological deficits and occasionally progresses to death. We present our experience with surgery on radiation induced temporal lobe necrosis (RTLN) in nasopharyngeal carcinoma (NPC) patients with special consideration of clinical presentation, surgical technique, and outcomes. This retrospective study includes 12 patients with RTLN treated by the senior author between January 2010 and December 2014. Patients initially sought medical treatment due to headache; other symptoms were hearing loss, visual deterioration, seizure, hemiparesis, vertigo, memory loss and agnosia. A temporal approach through a linear incision was performed for all cases. RTLN was found in one side in 7 patients, and bilaterally in 5. 4 patients underwent resection of necrotic tissue bilaterally and 8 patients on one side. No death occurred in this series of cases. There were no post-operative complications, except 1 patient who developed aseptic meningitis. All 12 patients were free from headache. No seizure occurred in patients with preoperative epilepsy. Other symptoms such as hemiparesis and vertigo improved in all patients. Memory loss, agnosia and hearing loss did not change post-operatively in all cases. The follow-up MR images demonstrated no recurrence of necrotic lesions in all 12 patients. Neurosurgical intervention through a temporal approach with linear incision is warranted in patients with radiation induced temporal lobe necrosis with significant symptoms and signs of increased intracranial pressure, minimum space occupying effect on imaging, or neurological deterioration despite conservative management. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

The predictive value of FDG-PET with 3D-SSP for surgical outcomes in patients with temporal lobe epilepsy.

PubMed

Higo, Takuma; Sugano, Hidenori; Nakajima, Madoka; Karagiozov, Kostadin; Iimura, Yasushi; Suzuki, Masaru; Sato, Kiyoshi; Arai, Hajime

2016-10-01

We retrospectively evaluated the diagnostic value of (18)F-2-fluorodeoxy-d-glucose positron emission tomography (FDG-PET) with statistical analysis for the foci detection and predictive utility for postsurgical seizure outcome of patients with mesial temporal lobe epilepsy (mTLE). We evaluated 40 patients who were diagnosed mTLE and underwent selective amygdalohippocampectomy (SAH) or anterior temporal lobectomy (ATL) in our institute. Preoperative interictal FDG-PET with statistical analysis using three-dimensional stereotactic surface projection (3D-SSP) was detected with several clinical data including seizure semiology, MRI, scalp electroencephalography, surgical procedure with SAH or ATL and postsurgical outcome. The region of interest (ROI) was defined on 'Hippocampus & Amygdala', 'Parahippocampal gyrus & Uncus', 'T1 & T2', and 'T3 & Fusiform gyrus'. We obtained the ratio of hypometabolism difference (RHD) by 3D-SSP, and evaluated the relation among hypometabolic extent, surgical outcome and surgical procedure. The RHD in each ROIs ipsilateral to operative side was significantly higher than that of contralateral side in good outcome group. Hypometabolism of 'Hippocampus & Amygdala' was most reliable prognostic factor. Patients of discordant with presurgical examinations hardly showed obvious lateralized hypometabolism. Nevertheless, when they have significantly high RHD in mesial temporal lobe, good surgical outcome was expected. There was not significant difference of RHD distribution between SAH and ATL in good outcome group. Significant hypometabolism in mesial temporal lobe on FDG-PET with 3D-SSP is useful to predict good surgical outcome for patients with mTLE, particularly in discordant patients with hypometabolism in mesial temporal structure. However, FDG-PET is not indicative of surgical procedure. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Cognitive Function and Heat Shock Protein 70 in Children With Temporal Lobe Epilepsy.

PubMed

Oraby, Azza M; Raouf, Ehab R Abdol; El-Saied, Mostafa M; Abou-Khadra, Maha K; Helal, Suzette I; Hashish, Adel F

2017-01-01

We conducted the present study to examine cognitive function and serum heat shock protein 70 levels among children with temporal lobe epilepsy. The Stanford-Binet Intelligence Test was carried out to examine cognitive function in 30 children with temporal lobe epilepsy and 30 controls. Serum heat shock protein 70 levels were determined with an enzyme-linked immunosorbent assay. The epilepsy group had significantly lower cognitive function testing scores and significantly higher serum heat shock protein 70 levels than the control group; there were significant negative correlations between serum heat shock protein 70 levels and short-term memory and composite scores. Children with uncontrolled seizures had significantly lower verbal reasoning scores and significantly higher serum heat shock protein 70 levels than children with controlled seizures. Children with temporal lobe epilepsy have cognitive dysfunction and elevated levels of serum heat shock protein 70, which may be considered a stress biomarker.

Cholinesterase inhibitors are compatible with psychosocial intervention for Alzheimer disease patients suggested by neuroimaging findings.

PubMed

Meguro, Kenichi

2017-01-30

We previously reported that the frontal lobe was stimulated by psychosocial intervention for dementia patients, and that the parietal lobe was associated with logical judgment. We hypothesized that the combined therapeutic approach with symptomatic drug treatment can directly stimulate not only attention function but also judgment function indirectly to observing other participants' behaviors. Fifty-two patients with Alzheimer disease underwent the group reminiscence approach with reality orientation, as well as the donepezil treatment. The cerebral blood flow (CBF) was assessed with 99m Tc-ECD SPECT. Two analyses were performed: Analysis 1 was to compare Responders vs. Non-responders as shown by MMSE scores, whereas Analysis 2 was to compare Good vs. Poor reminders of the intervention content. We found that the CBF in the frontal lobe was significantly higher in Responders (vs. Non-responders). The CBF in the parietal lobe, especially the left side, was significantly higher in the Good reminders (vs. Poor reminders). The donepezil stimulated the areas similar to where the psychosocial intervention was previously found to be stimulated directly, thus the drug was thought to be compatible for psychosocial intervention. The parietal lobe was stimulated indirectly, suggesting that the indirect effect of the intervention may be based on logical judgment function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Kumagusu Minakata with temporal lobe epilepsy: a pathographic study].

PubMed

Sengoku, Akira

2006-01-01

Kumagusu Minakata (1867-1941), a Japanese genius devoted to natural history and folklore, is famous for his immense range of works (including 50 monographs in 'Nature') and his discovery of several varieties of mycetozoa. His diary and the observations of other persons reveal that he was affected by several grand mal epileptic seizures, and he complained himself of frequent déjà vu experiences which he called promnesia according to Myers. Promnesia means, for example, "I have lived through all this before, and I know what will happen this next minute." Minakata also had this rare type of aural sign. MRI analysis of his postmortem brain found evidence of right hippocampal atrophy. This result showed that he had temporal lobe epilepsy with focus of the right side, and this coincides with his déjà vu experiences which were the aura of the loss of consciousness. However, he did not notice that these were aural signs, and he also complained of memory disturbances due to frequent déjà vu. His behavioral characteristics were peculiar, and those of Dostoyevsky who also had temporal lobe epilepsy were similar. Temporal lobe epilepsies may influence behavioral patterns which control the emotions. As a positive point, some patients with temporal lobe epilepsy can exhibit their primordial mental actions and perform persistent works.

Familial temporal lobe epilepsy due to focal cortical dysplasia type IIIa.

PubMed

Fabera, Petr; Krijtova, Hana; Tomasek, Martin; Krysl, David; Zamecnik, Josef; Mohapl, Milan; Jiruska, Premysl; Marusic, Petr

2015-09-01

Focal cortical dysplasia (FCD) represents a common cause of refractory epilepsy. It is considered a sporadic disorder, but its occasional familial occurrence suggests the involvement of genetic mechanisms. Siblings with intractable epilepsy were referred for epilepsy surgery evaluation. Both patients were examined using video-EEG monitoring, MRI examination and PET imaging. They underwent left anteromedial temporal lobe resection. Electroclinical features pointed to left temporal lobe epilepsy and MRI examination revealed typical signs of left-sided hippocampal sclerosis and increased white matter signal intensity in the left temporal pole. PET examination confirmed interictal hypometabolism in the left temporal lobe. Histopathological examination of resected tissue demonstrated the presence FCD type IIIa, i.e. hippocampal sclerosis and focal cortical dysplasia in the left temporal pole. We present a unique case of refractory mesial temporal lobe epilepsy in siblings, characterized by an identical clinical profile and histopathology of FCD type IIIa, who were successfully treated by epilepsy surgery. The presence of such a high concordance between the clinical and morphological data, together with the occurrence of epilepsy and febrile seizures in three generations of the family pedigree points towards a possible genetic nature of the observed FCD type IIIa. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Major Martian Volcanoes from MOLA - Arsia Mons

NASA Technical Reports Server (NTRS)

2000-01-01

Two views of Arsia Mons, the southern most of the Tharsis montes, shown as topography draped over a Viking image mosaic. MOLA topography clearly shows the caldera structure and the flank massive breakout that produced a major side lobe. The vertical exaggeration is 10:1.

Coded excitation with spectrum inversion (CEXSI) for ultrasound array imaging.

PubMed

Wang, Yao; Metzger, Kurt; Stephens, Douglas N; Williams, Gregory; Brownlie, Scott; O'Donnell, Matthew

2003-07-01

In this paper, a scheme called coded excitation with spectrum inversion (CEXSI) is presented. An established optimal binary code whose spectrum has no nulls and possesses the least variation is encoded as a burst for transmission. Using this optimal code, the decoding filter can be derived directly from its inverse spectrum. Various transmission techniques can be used to improve energy coupling within the system pass-band. We demonstrate its potential to achieve excellent decoding with very low (< 80 dB) side-lobes. For a 2.6 micros code, an array element with a center frequency of 10 MHz and fractional bandwidth of 38%, range side-lobes of about 40 dB have been achieved experimentally with little compromise in range resolution. The signal-to-noise ratio (SNR) improvement also has been characterized at about 14 dB. Along with simulations and experimental data, we present a formulation of the scheme, according to which CEXSI can be extended to improve SNR in sparse array imaging in general.

MSU Antenna Pattern Data

NASA Technical Reports Server (NTRS)

Mo, Tsan; Kleespies, Thomas J.; Green, J. Philip

2000-01-01

The Microwave Sounding Unit (MSU) antenna pattern data for nine MSU Flight Models (FMs) have been successfully rescued from 22-year old 7-track and 9-track magnetic tapes and cartridges. These antenna pattern data were unpacked into user-friendly ASCII format, and are potentially useful for making antenna pattern corrections to MSU antenna temperatures in retrieving the true brightness temperatures. We also properly interpreted the contents of the data and show how to convert the measured antenna signal amplitude in volts into relative antenna power in dB with proper normalization. It is found that the data are of high quality with a 60-dB drop in the co-polarized antenna patterns from the central peak value to its side-lobe regions at scan angles beyond 30 deg. The unpacked antenna pattern data produced in this study provide a useful database for data users to correct the antenna side-lobe contribution to MSU measurements. All of the data are available to the scientific community on a single CD-ROM.

Temporal lobe epilepsy: origin and significance of simple and complex auras.

PubMed Central

Taylor, D C; Lochery, M

1987-01-01

The aura experience of 88 patients with temporal lobe epilepsy was recorded, classified and analysed. Despite the great richness of the 215 experiences described, correlations with left or right brain, nature of lesion, age of onset, etc. were only apparent when a classification into three aura groups was used. "Simple primitive" auras as sole auras were more likely with early onset epilepsy, in lower IQ patients, in males, from the right temporal lobe, and with mesial temporal sclerosis. Exclusively "intellectual" auras were confined to a group of high IQ males. The number of aura experiences described per person correlated with Verbal IQ for males but not females, but also varied with side, sex, and nature of lesion. The results are discussed in terms of the necessary conditions for aura and their relevance and in relationship to the results of brain stimulation studies by Penfield and others. PMID:3612148

Functional correlates of musical and visual ability in frontotemporal dementia.

PubMed

Miller, B L; Boone, K; Cummings, J L; Read, S L; Mishkin, F

2000-05-01

The emergence of new skills in the setting of dementia suggests that loss of function in one brain area can release new functions elsewhere. To characterise 12 patients with frontotemporal dementia (FTD) who acquired, or sustained, new musical or visual abilities despite progression of their dementia. Twelve patients with FTD who acquired or maintained musical or artistic ability were compared with 46 patients with FTD in whom new or sustained ability was absent. The group with musical or visual ability performed better on visual, but worse on verbal tasks than did the other patients with FTD. Nine had asymmetrical left anterior dysfunction. Nine showed the temporal lobe variant of FTD. Loss of function in the left anterior temporal lobe may lead to facilitation of artistic or musical skills. Patients with the left-sided temporal lobe variant of FTD offer an unexpected window into the neurological mediation of visual and musical talents.

Loculated pneumothorax due to a rare combination resulting in an interesting chest radiograph.

PubMed

Isaac, Barney Thomas Jesudason; Samuel, Johnson Thamarathu; Mukherjee, Dipak K; Pittman, Marcus

2017-11-01

A 35 years old man presented with acute onset left sided pleuritic chest pain and shortness of breath. On evaluation, he was found to have an interesting chest radiograph which showed a loculated pneumothorax with collapse of the left upper lobe and lingula but fully expanded left lower lobe. He is a known asthmatic who had allergic broncho pulmonary aspergillosis (ABPA) previously with left upper lobe and lingular collapse secondary to mucous plugging. This resolved on treatment with steroids and itraconazole. An interesting combination of events is proposed to explain the current presentation. CT scan chest and blood tests confirmed this sequence of events. He was appropriately treated resulting in complete clinical and radiological recovery. The events leading to the presentation and the likely physiological background for this interesting chest radiograph are discussed. © 2016 John Wiley & Sons Ltd.

Vibration detecting apparatus for multi-rotor rotary piston engines

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

Fujimoto, Y.; Sasaki, H.; Karimata, Y.

1987-04-28

A multi-rotor rotary piston engine is described comprising rotor housings each having an inner wall surface of a two-lobe trochoidal form, an intermediate housing having opposite side surfaces and located between two adjacent ones of the rotor housings, a pair of side housings attached to outer surfaces of outermost rotor housings, rotors which are disposed in respective ones of the rotor housings and carried by an eccentric shaft, adjacent rotors each having a side surface adapted for sliding engagement with the side surfaces of the intermediate housing, vibration detecting means mounted on the intermediate housing for detecting engine vibrations, themore » vibration detecting means being oriented so that it has a sensitivity in the direction substantially perpendicular to the side surface of the intermediate housing.« less

Long-term consequences of a prolonged febrile seizure in a dual pathology model.

PubMed

Gibbs, Steve; Chattopadhyaya, Bidisha; Desgent, Sébastien; Awad, Patricia N; Clerk-Lamalice, Olivier; Levesque, Maxime; Vianna, Rose-Mari; Rébillard, Rose-Marie; Delsemme, Andrée-Anne; Hébert, David; Tremblay, Luc; Lepage, Martin; Descarries, Laurent; Di Cristo, Graziella; Carmant, Lionel

2011-08-01

Clinical evidence suggests that febrile status epilepticus (SE) in children can lead to acute hippocampal injury and subsequent temporal lobe epilepsy. The contribution of febrile SE to the mechanisms underlying temporal lobe epilepsy are however poorly understood. A rat model of temporal lobe epilepsy following hyperthermic SE was previously established in our laboratory, wherein a focal cortical lesion induced at postnatal day 1 (P1), followed by a hyperthermic SE (more than 30 min) at P10, leads to hippocampal atrophy at P22 (dual pathology model) and spontaneous recurrent seizures (SRS) with mild visuospatial memory deficits in adult rats. The goal of this study was to identify the long term electrophysiological, anatomical and molecular changes in this model. Following hyperthermic SE, all cortically lesioned pups developed progressive SRS as adults, characterized by the onset of highly rhythmic activity in the hippocampus. A reduction of hippocampal volume on the side of the lesion preceded the SRS and was associated with a loss of hippocampal neurons, a marked decrease in pyramidal cell spine density, an increase in the hippocampal levels of NMDA receptor NR2A subunit, but no significant change in GABA receptors. These findings suggest that febrile SE in the abnormal brain leads to hippocampal injury that is followed by progressive network reorganization and molecular changes that contribute to the epileptogenesis as well as the observed memory deficits. Copyright © 2011 Elsevier Inc. All rights reserved.

Wake-Up Right-Sided Hemiparesis and Dysarthria in a Heavy Snorer.

PubMed

Brunetti, Valerio; Ferilli, Michela Ada Noris; Vollono, Catello; Di Franco, Antonino; Della Marca, Giacomo

2018-01-01

A 57-year-old man was referred to the ED for wake-up right-sided hemiparesis, hypoesthesia, dysarthria, and a National Institutes of Health Stroke Scale score of 7. Urgent CT brain scanning showed an ischemic lesion of the left temporal and insular lobes. The patient was admitted to the stroke unit, and acetylsalicylic acid 300 mg and low-molecular-weight heparin 6,000 IU were administered. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Human-like brain hemispheric dominance in birdsong learning.

PubMed

Moorman, Sanne; Gobes, Sharon M H; Kuijpers, Maaike; Kerkhofs, Amber; Zandbergen, Matthijs A; Bolhuis, Johan J

2012-07-31

Unlike nonhuman primates, songbirds learn to vocalize very much like human infants acquire spoken language. In humans, Broca's area in the frontal lobe and Wernicke's area in the temporal lobe are crucially involved in speech production and perception, respectively. Songbirds have analogous brain regions that show a similar neural dissociation between vocal production and auditory perception and memory. In both humans and songbirds, there is evidence for lateralization of neural responsiveness in these brain regions. Human infants already show left-sided dominance in their brain activation when exposed to speech. Moreover, a memory-specific left-sided dominance in Wernicke's area for speech perception has been demonstrated in 2.5-mo-old babies. It is possible that auditory-vocal learning is associated with hemispheric dominance and that this association arose in songbirds and humans through convergent evolution. Therefore, we investigated whether there is similar song memory-related lateralization in the songbird brain. We exposed male zebra finches to tutor or unfamiliar song. We found left-sided dominance of neuronal activation in a Broca-like brain region (HVC, a letter-based name) of juvenile and adult zebra finch males, independent of the song stimulus presented. In addition, juvenile males showed left-sided dominance for tutor song but not for unfamiliar song in a Wernicke-like brain region (the caudomedial nidopallium). Thus, left-sided dominance in the caudomedial nidopallium was specific for the song-learning phase and was memory-related. These findings demonstrate a remarkable neural parallel between birdsong and human spoken language, and they have important consequences for our understanding of the evolution of auditory-vocal learning and its neural mechanisms.

Frontal lobe functioning during a simple response conflict task in first-episode psychosis and its relationship to treatment response.

PubMed

Shafritz, Keith M; Ikuta, Toshikazu; Greene, Allison; Robinson, Delbert G; Gallego, Juan; Lencz, Todd; DeRosse, Pamela; Kingsley, Peter B; Szeszko, Philip R

2018-05-09

Prior functional magnetic resonance imaging (fMRI) studies have investigated the neural mechanisms underlying cognitive control in patients with psychosis with findings of both hypo- and hyperfrontality. One factor that may contribute to inconsistent findings is the use of complex and polyfactorial tasks to investigate frontal lobe functioning. In the current study we employed a simple response conflict task during fMRI to examine differences in brain activation between patients experiencing their first-episode of psychosis (n = 33) and age- and sex-matched healthy volunteers (n = 33). We further investigated whether baseline brain activation among patients predicted changes in symptom severity and treatment response following 12 weeks of controlled antipsychotic treatment. During the task subjects were instructed to press a response button on the same side or opposite side of a circle that appeared on either side of a central fixation point. Imaging data revealed that for the contrast of opposite-side vs. same-side, patients showed significantly greater activation compared with healthy volunteers in the anterior cingulate cortex and intraparietal sulcus. Among patients, greater baseline anterior cingulate cortex, temporal-parietal junction, and superior temporal cortex activation predicted greater symptom reduction and therapeutic response following treatment. All findings remained significant after covarying for task performance. Intact performance on this relatively parsimonious task was associated with frontal hyperactivity suggesting the need for patients to utilize greater neural resources to achieve task performance comparable to healthy individuals. Moreover, frontal hyperactivity observed using a simple fMRI task may provide a biomarker for predicting treatment response in first-episode psychosis.

Toward a better understanding of the savant brain.

PubMed

Corrigan, Neva M; Richards, Todd L; Treffert, Darold A; Dager, Stephen R

2012-08-01

The objectives of this study are to investigate the neuroanatomy, regional brain connectivity, and neurochemistry of a prodigious artistic savant; to place these findings within the context of existing neuroimaging literature of savant syndrome; and to discuss the utility of newer imaging modalities to extend our current understanding of mechanisms underlying savant skills. High-resolution magnetic resonance (MR) imaging, J-resolved MR spectroscopy, and diffusion tensor imaging data were acquired during a single scanning session for a 63-year-old male autistic savant with prodigious artistic skills. Regional and compartmental brain volumes, N-acetyl aspartate, choline, creatine, glutamate and γ-aminobutyric acid concentrations, fractional anisotropy values, and white matter bundle volumes as well as axial, radial, and mean diffusivities were calculated. No gross anatomical differences were observed. By morphological assessment, cerebral volume (1362 mL) was larger than normative literature values for adult males. The corpus callosum was intact and did not exhibit abnormal structural features. The right cerebral hemisphere was 1.9% larger than the left hemisphere; the right amygdala and right caudate nuclei were 24% and 9.9% larger, respectively, compared with the left side. In contrast, the putamen was 8.3% larger on the left side. Fractional anisotropy was increased on the right side as compared with the left for 4 of the 5 bilateral regions studied (the amygdala, caudate, frontal lobe, and hippocampus). Fiber tract bundle volumes were larger on the right side for the amygdala, hippocampus, frontal lobe, and occipital lobe. Both the left and the right hippocampi had substantially increased axial and mean diffusivities as compared with those of a comparison sample of nonsavant adult males. The corpus callosum and left amygdala also exhibited high axial, radial, and mean diffusivities. MR spectroscopy revealed markedly decreased γ-aminobutyric acid and glutamate in the parietal lobe. Although examination of brain gross morphometry demonstrated no clinically remarkable abnormalities, utilization of conventional as well as newer MR imaging technologies revealed several atypical structural and chemical features that may be involved in the special skills of this prodigious savant. The multimodal imaging approach presented in this study is suitable for the evaluation of larger samples of savants with a diverse range of talents to investigate common brain features that may underlie the exceptional cognitive capabilities characteristic of savant syndrome. Given the high co-occurrence of the two syndromes, elucidating the underlying neurophysiologic basis of savant syndrome may also lead to a better understanding of autism spectrum disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

Rapid Decision-Making with Side-Specific Perceptual Discrimination in Ants

PubMed Central

Stroeymeyt, Nathalie; Guerrieri, Fernando J.; van Zweden, Jelle S.; d'Ettorre, Patrizia

2010-01-01

Background Timely decision making is crucial for survival and reproduction. Organisms often face a speed-accuracy trade-off, as fully informed, accurate decisions require time-consuming gathering and treatment of information. Optimal strategies for decision-making should therefore vary depending on the context. In mammals, there is mounting evidence that multiple systems of perceptual discrimination based on different neural circuits emphasize either fast responses or accurate treatment of stimuli depending on the context. Methodology/Principal Findings We used the ant Camponotus aethiops to test the prediction that fast information processing achieved through direct neural pathways should be favored in situations where quick reactions are adaptive. Social insects discriminate readily between harmless group-members and dangerous strangers using easily accessible cuticular hydrocarbons as nestmate recognition cues. We show that i) tethered ants display rapid aggressive reactions upon presentation of non-nestmate odor (120 to 160 ms); ii) ants' aggressiveness towards non-nestmates can be specifically reduced by exposure to non-nestmate odor only, showing that social interactions are not required to alter responses towards non-nestmates; iii) decision-making by ants does not require information transfer between brain hemispheres, but relies on side-specific decision rules. Conclusions/Significance Our results strongly suggest that first-order olfactory processing centers (up to the antennal lobes) are likely to play a key role in ant nestmate recognition. We hypothesize that the coarse level of discrimination achieved in the antennal lobes early in odor processing provides enough information to determine appropriate behavioral responses towards non-nestmates. This asks for a reappraisal of the mechanisms underlying social recognition in insects. PMID:20808782

Tunable complex-valued multi-tap microwave photonic filter based on single silicon-on-insulator microring resonator.

PubMed

Lloret, Juan; Sancho, Juan; Pu, Minhao; Gasulla, Ivana; Yvind, Kresten; Sales, Salvador; Capmany, José

2011-06-20

A complex-valued multi-tap tunable microwave photonic filter based on single silicon-on-insulator microring resonator is presented. The degree of tunability of the approach involving two, three and four taps is theoretical and experimentally characterized, respectively. The constraints of exploiting the optical phase transfer function of a microring resonator aiming at implementing complex-valued multi-tap filtering schemes are also reported. The trade-off between the degree of tunability without changing the free spectral range and the number of taps is studied in-depth. Different window based scenarios are evaluated for improving the filter performance in terms of the side-lobe level.

[Right-sided hemihepatectomy in echinococcosis of the liver in pregnancy].

PubMed

Blöchle, C; Lloyd, D M; Izbicki, J R; Schröder, S; Brölsch, C E

1993-07-01

The treatment of symptomatic echinococcal disease of the liver during pregnancy is a rare, but difficult problem. A 42 year old, pregnant woman with obstructive jaundice and acute cholangitis due to extensive echinococcus cysticus infection of the right hepatic lobe is presented. A formal, right hemihepatectomy was successfully performed.

GPS Space Service Volume: Ensuring Consistent Utility Across GPS Design Builds for Space Users

NASA Technical Reports Server (NTRS)

Bauer, Frank H.; Parker, Joel Jefferson Konkl; Valdez, Jennifer Ellen

2015-01-01

GPS availability and signal strength originally specified for users on or near surface of Earth with transmitted power levels specified at edge-of-Earth, 14.3 degrees. Prior to the SSV specification, on-orbit performance of GPS varied from block build to block build (IIA, IIRM, IIF) due to antenna gain and beam width variances. Unstable on-orbit performance results in significant risk to space users. Side-lobe signals, although not specified, were expected to significantly boost GPS signal availability for users above the constellation. During GPS III Phase A, NASA noted significant discrepancies in power levels specified in GPS III specification documents, and measured on-orbit performance. To stabilize the signal for high altitude space users, NASA DoD team in 2003-2005 led the creation of new Space Service Volume (SSV) definition and specifications.

Changing patterns of brain activation during maze learning.

PubMed

Van Horn, J D; Gold, J M; Esposito, G; Ostrem, J L; Mattay, V; Weinberger, D R; Berman, K F

1998-05-18

Recent research has found that patterns of brain activation involving the frontal cortex during novel task performance change dramatically following practice and repeat performance. Evidence for differential left vs. right frontal lobe activation, respectively, during episodic memory encoding and retrieval has also been reported. To examine these potentially related issues regional cerebral blood flow (rCBF) was measured in 15 normal volunteers using positron emission tomography (PET) during the naive and practiced performance of a maze task paradigm. SPM analysis indicated a largely right-sided, frontal lobe activation during naive performance. Following training and practice, performance of the same maze task elicited a more posterior pattern of rCBF activation involving posterior cingulate and precuneus. The change in the pattern of rCBF activation between novel and practiced task conditions agrees with results found in previous studies using repeat task methodology, and indicates that the neural circuitry required for encoding novel task information differs from that required when the same task has become familiar and information is being recalled. The right-sided preponderance of activation during naive performance may relate to task novelty and the spatially-based nature of the stimuli, whereas posterior areas activated during repeat performance are those previously found to be associated with visuospatial memory recall. Activation of these areas, however, does not agree with previously reported findings of left-sided activation during verbal episodic memory encoding and right-sided activation during retrieval, suggesting different neural substrates for verbal and visuospatial processing within memory. Copyright 1998 Elsevier Science B.V.

Dynamics of copper-phthalocyanine molecules on Au/Ge(001).

PubMed

Sotthewes, K; Heimbuch, R; Zandvliet, H J W

2015-10-07

Spatially resolved current-time scanning tunneling spectroscopy combined with current-distance spectroscopy has been used to characterize the dynamic behavior of copper-phthalocyanine (CuPc) molecules adsorbed on a Au-modified Ge(001) surface. The analyzed CuPc molecules are adsorbed in a "molecular bridge" configuration, where two benzopyrrole groups (lobes) are connected to a Au-induced nanowire, whereas the other two lobes are connected to the adjacent nanowire. Three types of lobe configurations are found: a bright lobe, a dim lobe, and a fuzzy lobe. The dim and fuzzy lobes exhibit a well-defined switching behavior between two discrete levels, while the bright lobe shows a broad oscillation band. The observed dynamic behavior is induced by electrons that are injected into the LUMO+1 orbital of the CuPc molecule. By precisely adjusting the tip-molecule distance, the switching frequency of the lobes can be tuned accurately.

Dynamics of copper-phthalocyanine molecules on Au/Ge(001)

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

Sotthewes, K.; Heimbuch, R.; Zandvliet, H. J. W.

2015-10-07

Spatially resolved current-time scanning tunneling spectroscopy combined with current-distance spectroscopy has been used to characterize the dynamic behavior of copper-phthalocyanine (CuPc) molecules adsorbed on a Au-modified Ge(001) surface. The analyzed CuPc molecules are adsorbed in a “molecular bridge” configuration, where two benzopyrrole groups (lobes) are connected to a Au-induced nanowire, whereas the other two lobes are connected to the adjacent nanowire. Three types of lobe configurations are found: a bright lobe, a dim lobe, and a fuzzy lobe. The dim and fuzzy lobes exhibit a well-defined switching behavior between two discrete levels, while the bright lobe shows a broad oscillationmore » band. The observed dynamic behavior is induced by electrons that are injected into the LUMO+1 orbital of the CuPc molecule. By precisely adjusting the tip-molecule distance, the switching frequency of the lobes can be tuned accurately.« less

Brain activity associated with memory and cognitive function during jaw-tapping movement in healthy subjects using functional magnetic resonance imaging.

PubMed

Cho, Seung-Yeon; Shin, Ae-Sook; Na, Byung-Jo; Jahng, Geon-Ho; Park, Seong-Uk; Jung, Woo-Sang; Moon, Sang-Kwan; Park, Jung-Mi

2013-06-01

To determine whether jaw-tapping movement, a classically described as an indication of personal well-being and mental health, stimulates the memory and the cognitive regions of the brain and is associated with improved brain performance. Twelve healthy right-handed female subjects completed the study. Each patient performed a jaw-tapping task and an n-back task during functional magnetic resonance imaging (fMRI). The subjects were trained to carry out the jaw-tapping movement at home twice a day for 4 weeks. The fMRI was repeated when they returned. During the first and second jaw-tapping session, both sides of precentral gyrus and the right middle frontal gyrus (BA 6) were activated. And during the second session of the jaw-tapping task, parts of frontal lobe and temporal lobe related to memory function were more activated. In addition, the total percent task accuracy in n-back task significantly increased after 4 weeks of jawtapping movement. After jaw-tapping training for 4 weeks, brain areas related to memory showed significantly increased blood oxygen level dependent signals. Jaw-tapping movement might be a useful exercise for stimulating the memory and cognitive regions of the brain.

Surgical Management and Long-Term Seizure Outcome After Surgery for Temporal Lobe Epilepsy Associated with Cerebral Cavernous Malformations.

PubMed

Yang, Peng-Fan; Pei, Jia-Sheng; Jia, Yan-Zeng; Lin, Qiao; Xiao, Hui; Zhang, Ting-Ting; Zhong, Zhong-Hui

2018-02-01

Operative strategies for cerebral cavernous malformation (CCM)-associated temporal lobe epilepsy and timing of surgical intervention continue to be debated. This study aimed to establish an algorithm to evaluate the efficacy of surgical intervention strategies, to maximize positive surgical outcomes and minimize postsurgical neurologic deficits. 47 patients having undergone operation for CCM-associated temporal lobe epilepsy were retrospectively reviewed. They had received a diagnostic series for seizure localization, including long-term video electroencephalography (vEEG), high-resolution magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT). In patients with mesial temporal lobe CCMs, the involved structures (amygdala, hippocampus, or parahippocampal gyrus) were resected in addition to the lesions. Patients with neocortical epileptogenic CCM underwent extended lesionectomy guided by intraoperative electrocorticography; further performance of amygdalohippocampectomy depended on the extent of hippocampal epileptogenicity. The study cohort contained 28 patients with drug-resistant epilepsy (DRE), 12 with chronic epilepsy (CE), and 7 with sporadic seizure (SS). Normal temporal lobe metabolism was seen in 7/7 patients of the SS group. Hypometabolism was found in all patients with chronic disease except for those with posterior inferior and middle temporal gyrus cavernous malformations (CMs). Of the 31 patients with superficial neocortical CCM, 7 had normal PET without hippocampal sclerosis, 14 had ipsilateral temporal lobe hypometabolism without hippocampal sclerosis, and 10 had obvious hippocampal sclerosis and hypometabolism. Seizure freedom in DRE, CE, and SS was 82.1%, 75%, and 100%, respectively. A significant difference was found between lesion laterality and postoperative seizure control; the rate was lower in left-sided cases because of less aggressive resection. Our study demonstrates that the data from the presurgical evaluation, particularly regarding CM location, responsiveness to antiepileptic drugs, and temporal lobe metabolism, are crucial parameters for choosing surgical approaches to CCM-associated temporal lobe epilepsy. By this operative strategy, patients may receive maximized seizure control and minimized postsurgical neurologic sequelae. Copyright © 2017 Elsevier Inc. All rights reserved.

Neocortical temporal FDG-PET hypometabolism correlates with temporal lobe atrophy in hippocampal sclerosis associated with microscopic cortical dysplasia.

PubMed

Diehl, Beate; LaPresto, Eric; Najm, Imad; Raja, Shanker; Rona, Sabine; Babb, Thomas; Ying, Zhong; Bingaman, William; Lüders, Hans O; Ruggieri, Paul

2003-04-01

Medically intractable temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), with or without cortical dysplasia (CD), is associated with atrophy of the hippocampal formation and regional fluorodeoxyglucose positron-emission tomography (FDG-PET) hypometabolism. The relation between areas of functional and structural abnormalities is not well understood. We investigate the relation between FDG-PET metabolism and temporal lobe (TL) and hippocampal atrophy in patients with histologically proven isolated HS and HS associated with CD. Twenty-three patients underwent en bloc resection of the mesial and anterolateral neocortical structures. Ten patients were diagnosed with isolated HS; 13 patients had associated microscopic CD. Temporal lobe volumes (TLVs) and hippocampal volumes were measured. Magnetic resonance imaging (MRI) and PET were co-registered, and regions of interest (ROIs) determined as gray matter of the mesial, lateral, and anterior temporal lobe. All patients (HS with or without CD) had significant ipsilateral PET hypometabolism in all three regions studied (p < 0.0001). In patients with isolated HS, the most prominent hypometabolism was in the anterior and mesial temporal lobe, whereas in dual pathology, it was in the lateral temporal lobe. TLVs and hippocampal volumes were significantly smaller on the epileptogenic side (p < 0.05). The PET asymmetries ipsilateral/contralateral to the epileptogenic zone and TLV asymmetries correlated significantly for the anterior and lateral temporal lobes (p < 0.05) in the HS+CD group, but not in the isolated HS group. Mesial temporal hypometabolism was not significantly different between the two groups. Temporal neocortical microscopic CD with concurrent HS is associated with more prominent lateral temporal metabolic dysfunction compared with isolated HS in TL atrophy. Further studies are needed to confirm these findings and correlate the PET hypometabolic patterns with outcome data in patients operated on for HS with or without CD.

Temporal lobe surgery in childhood and neuroanatomical predictors of long-term declarative memory outcome

PubMed Central

Skirrow, Caroline; Cross, J. Helen; Harrison, Sue; Cormack, Francesca; Harkness, William; Coleman, Rosie; Meierotto, Ellen; Gaiottino, Johanna; Vargha-Khadem, Faraneh

2015-01-01

The temporal lobes play a prominent role in declarative memory function, including episodic memory (memory for events) and semantic memory (memory for facts and concepts). Surgical resection for medication-resistant and well-localized temporal lobe epilepsy has good prognosis for seizure freedom, but is linked to memory difficulties in adults, especially when the removal is on the left side. Children may benefit most from surgery, because brain plasticity may facilitate post-surgical reorganization, and seizure cessation may promote cognitive development. However, the long-term impact of this intervention in children is not known. We examined memory function in 53 children (25 males, 28 females) who were evaluated for epilepsy surgery: 42 underwent unilateral temporal lobe resections (25 left, 17 right, mean age at surgery 13.8 years), 11 were treated only pharmacologically. Average follow-up was 9 years (range 5–15). Post-surgical change in visual and verbal episodic memory, and semantic memory at follow-up were examined. Pre- and post-surgical T1-weighted MRI brain scans were analysed to extract hippocampal and resection volumes, and evaluate post-surgical temporal lobe integrity. Language lateralization indices were derived from functional magnetic resonance imaging. There were no significant pre- to postoperative decrements in memory associated with surgery. In contrast, gains in verbal episodic memory were seen after right temporal lobe surgery, and visual episodic memory improved after left temporal lobe surgery, indicating a functional release in the unoperated temporal lobe after seizure reduction or cessation. Pre- to post-surgical change in memory function was not associated with any indices of brain structure derived from MRI. However, better verbal memory at follow-up was linked to greater post-surgical residual hippocampal volumes, most robustly in left surgical participants. Better semantic memory at follow-up was associated with smaller resection volumes and greater temporal pole integrity after left temporal surgery. Results were independent of post-surgical intellectual function and language lateralization. Our findings indicate post-surgical, hemisphere-dependent material-specific improvement in memory functions in the intact temporal lobe. However, outcome was linked to the anatomical integrity of the temporal lobe memory system, indicating that compensatory mechanisms are constrained by the amount of tissue which remains in the operated temporal lobe. Careful tailoring of resections for children undergoing epilepsy surgery may enhance long-term memory outcome. PMID:25392199

Human-like brain hemispheric dominance in birdsong learning

PubMed Central

Moorman, Sanne; Gobes, Sharon M. H.; Kuijpers, Maaike; Kerkhofs, Amber; Zandbergen, Matthijs A.; Bolhuis, Johan J.

2012-01-01

Unlike nonhuman primates, songbirds learn to vocalize very much like human infants acquire spoken language. In humans, Broca’s area in the frontal lobe and Wernicke’s area in the temporal lobe are crucially involved in speech production and perception, respectively. Songbirds have analogous brain regions that show a similar neural dissociation between vocal production and auditory perception and memory. In both humans and songbirds, there is evidence for lateralization of neural responsiveness in these brain regions. Human infants already show left-sided dominance in their brain activation when exposed to speech. Moreover, a memory-specific left-sided dominance in Wernicke’s area for speech perception has been demonstrated in 2.5-mo-old babies. It is possible that auditory-vocal learning is associated with hemispheric dominance and that this association arose in songbirds and humans through convergent evolution. Therefore, we investigated whether there is similar song memory-related lateralization in the songbird brain. We exposed male zebra finches to tutor or unfamiliar song. We found left-sided dominance of neuronal activation in a Broca-like brain region (HVC, a letter-based name) of juvenile and adult zebra finch males, independent of the song stimulus presented. In addition, juvenile males showed left-sided dominance for tutor song but not for unfamiliar song in a Wernicke-like brain region (the caudomedial nidopallium). Thus, left-sided dominance in the caudomedial nidopallium was specific for the song-learning phase and was memory-related. These findings demonstrate a remarkable neural parallel between birdsong and human spoken language, and they have important consequences for our understanding of the evolution of auditory-vocal learning and its neural mechanisms. PMID:22802637

Massive malignant pleural effusion due to lung adenocarcinoma in 13-year-old boy.

PubMed

Afghani, Reza; Hajimohammadi, Amir; Azarhoush, Ramin; Kazemi-Nejad, Vahideh; Yari, Behrouz; Rezapour Esfahani, Mona

2016-05-01

A 13-year-old boy with no risk factors for lung cancer presented with a massive left-sided pleural effusion and a mediastinal shift on chest radiography and computed tomography. A chest tube drained bloody pleural fluid with an exudative pattern. A pleural biopsy and wedge biopsy of the left lower lobe revealed mucinous adenocarcinoma in the left lower lobe wedge biopsy and metastatic adenocarcinoma in the pleural biopsy. The patient is currently undergoing chemotherapy. Radiotherapy is planned after shrinkage of the tumor. Adenocarcinoma of the lung is very rarely seen in teenagers or children, especially in the absence of risk factors. © The Author(s) 2016.

Air Vehicle Integration and Technology Research (AVIATR). Delivery Order 0002: Condition-Based Maintenance Plus Structural Integrity (CBM+SI) Strategy Development

DTIC Science & Technology

2010-11-01

material. The rubber is laser -etched with rows of tiny, interconnected channels or galleries, to which air pressure is applied. Any propagating crack... clad one side. The Upper Lobe has a radius of approximately 85” (compound curvature) in the region of interest. As stated previously, the skin is...7079-T6 sheet; clad one side with a varying thickness of 0.050” to 0.071” (varies according to stability requirements for compression combined with

Functional MR imaging or Wada test: which is the better predictor of individual postoperative memory outcome?

PubMed

Dupont, Sophie; Duron, Emmanuelle; Samson, Séverine; Denos, Marisa; Volle, Emmanuelle; Delmaire, Christine; Navarro, Vincent; Chiras, Jacques; Lehéricy, Stéphane; Samson, Yves; Baulac, Michel

2010-04-01

To retrospectively determine whether blood oxygen level-dependent functional magnetic resonance (MR) imaging can aid prediction of postoperative memory changes in epileptic patients after temporal lobe surgery. This study was approved by the local ethics committee, and informed consent was obtained from all patients. Data were analyzed from 25 patients (12 women, 13 men; age range, 19-52 years) with refractory epilepsy in whom temporal lobe surgery was performed after they underwent preoperative functional MR imaging, the Wada test, and neuropsychological testing. The functional MR imaging protocol included three different memory tasks (24-hour delayed recognition, encoding, and immediate recognition). Individual activations were measured in medial temporal lobe (MTL) regions of both hemispheres. The prognostic accuracy of functional MR imaging for prediction of postoperative memory changes was compared with the accuracy of the Wada test and preoperative neuropsychological testing by using a backward multiple regression analysis. An equation that was based on left functional MR imaging MTL activation during delayed recognition, side of the epileptic focus, and preoperative global verbal memory score was used to correctly predict worsening of verbal memory in 90% of patients. The right functional MR imaging MTL activation did not substantially correlate with the nonverbal memory outcome, which was only predicted by using the preoperative nonverbal global score. Wada test data were not good predictors of changes in either verbal or nonverbal memory. Findings suggest that functional MR imaging activation during a delayed-recognition task is a better predictor of individual postoperative verbal memory outcome than is the Wada test. RSNA, 2010

Low-Profile, Dual-Wavelength, Dual-Polarized Antenna

NASA Technical Reports Server (NTRS)

Carswell, James R.

2010-01-01

A single-aperture, low-profile antenna design has been developed that supports dual-polarization and simultaneous operation at two wavelengths. It realizes multiple beams in the elevation plane, and supports radiometric, radar, and conical scanning applications. This antenna consists of multiple azimuth sticks, with each stick being a multilayer, hybrid design. Each stick forms the h-plane pattern of the C and Ku-band vertically and horizontally polarized antenna beams. By combining several azimuth sticks together, the elevation beam is formed. With a separate transceiver for each stick, the transmit phase and amplitude of each stick can be controlled to synthesize a beam at a specific incidence angle and to realize a particular side-lobe pattern. By changing the transmit phase distribution through the transceivers, the transmit antenna beam can be steered to different incidence angles. By controlling the amplitude distribution, different side lobe patterns and efficiencies can be realized. The receive beams are formed using digital beam synthesis techniques, resulting in very little loss in the receive path, thus enabling a very-low loss receive antenna to support passive measurements.

Speckle imaging of active galactic nuclei: NGC 1068 and NGC 4151

NASA Astrophysics Data System (ADS)

Ebstein, Steven Michael

High resolution images of NGC 1068 and NGC 4151 in the 5007 A line and the nearby continuum produced from data taken with the PAPA photon counting imaging detector using the technique of speckle imaging are presented. The images show an unresolved core of 5007 A emission in the middle of an extended emission region. The extended emission tends to lie alongside the subarcsecond radio structure. In NGC 4151, the extended emission comes from a nearly linear structure extending on both sides of the unresolved core. In NGC 1068, the extended emission is concentrated in lobes lying to the unresolved core but the emission is concentrated in lobes lying to either side of the major axis. The continuum of NGC 4151 is spatially unresolved. The continuum of NGC 1068 is extended approx. 1 in to the SW of the center of the 5007 A emission. Certain aspects of the PAPA detector are discussed, including the variable threshold discriminators that track the image intensifier pulse height and the camera artifacts. The data processing is described in detail.

NAVIGATION PERFORMANCE IN HIGH EARTH ORBITS USING NAVIGATOR GPS RECEIVER

NASA Technical Reports Server (NTRS)

Bamford, William; Naasz, Bo; Moreau, Michael C.

2006-01-01

NASA GSFC has developed a GPS receiver that can acquire and track GPS signals with sensitivity significantly lower than conventional GPS receivers. This opens up the possibility of using GPS based navigation for missions in high altitude orbit, such as Geostationary Operational Environmental Satellites (GOES) in a geostationary orbit, and the Magnetospheric MultiScale (MMS) Mission, in highly eccentric orbits extending to 12 Earth radii and higher. Indeed much research has been performed to study the feasibility of using GPS navigation in high Earth orbits and the performance achievable. Recently, GSFC has conducted a series of hardware in-the-loop tests to assess the performance of this new GPS receiver in various high Earth orbits of interest. Tracking GPS signals to down to approximately 22-25 dB-Hz, including signals from the GPS transmitter side-lobes, steady-state navigation performance in a geostationary orbit is on the order of 10 meters. This paper presents the results of these tests, as well as sensitivity analysis to such factors as ionosphere masks, use of GPS side-lobe signals, and GPS receiver sensitivity.

Mu-opiate receptors measured by positron emission tomography are increased in temporal lobe epilepsy.

PubMed

Frost, J J; Mayberg, H S; Fisher, R S; Douglass, K H; Dannals, R F; Links, J M; Wilson, A A; Ravert, H T; Rosenbaum, A E; Snyder, S H

1988-03-01

Neurochemical studies in animal models of epilepsy have demonstrated the importance of multiple neurotransmitters and their receptors in mediating seizures. The role of opiate receptors and endogenous opioid peptides in seizure mechanisms is well developed and is the basis for measuring opiate receptors in patients with epilepsy. Patients with complex partial seizures due to unilateral temporal seizure foci were studied by positron emission tomography using 11C-carfentanil to measure mu-opiate receptors and 18F-fluoro-deoxy-D-glucose to measure glucose utilization. Opiate receptor binding is greater in the temporal neocortex on the side of the electrical focus than on the opposite side. Modeling studies indicate that the increase in binding is due to an increase in affinity or the number of unoccupied receptors. No significant asymmetry of 11C-carfentanil binding was detected in the amygdala or hippocampus. Glucose utilization correlated inversely with 11C-carfentanil binding in the temporal neocortex. Increased opiate receptors in the temporal neocortex may represent a tonic anticonvulsant system that limits the spread of electrical activity from other temporal lobe structures.

Laparoscopic anatomy of the equine abdomen.

PubMed

Galuppo, L D; Snyder, J R; Pascoe, J R

1995-04-01

Laparoscopy was performed on 6 horses (2 mares, 2 geldings, 2 stallions) to determine the normal laparoscopic anatomy of the equine abdomen. After withholding feed for 36 hours, horses were examined from the left and right paralumbar fossae, and the visceral anatomic structures were recorded by videotape and photography. One mare developed emphysema located subcutaneously at the primary laparoscopic portal; otherwise, there were no complications. The anatomic structures of diagnostic importance that were observed in the left half of the abdomen were the hepatic duct; left lateral and quadrate lobes of the liver; stomach; spleen; left kidney with the associated nephrosplenic ligament; segments of jejunum, descending colon, and ascending colon; left side of the male and female reproductive tracts; urinary bladder; vaginal ring; and mesorchium. Important structures observed in the right side of the abdomen were portions of the common hepatic duct; left lateral, quadrate, and right lobes of the liver; caudate process of the liver; stomach; duodenum; right dorsal colon, epiploic foramen; omental bursa; right kidney; base of the cecum; segments of jejunum, descending colon, and ascending colon; urinary bladder; right half of the male and female reproductive tracts; and rectum.

Rhythmic ictal nonclonic hand (RINCH) motions in temporal lobe epilepsy: invasive EEG findings, incidence, and lateralizing value.

PubMed

Kuba, Robert; Musilová, Klára; Vojvodič, Nikola; Tyrlíková, Ivana; Rektor, Ivan; Brázdil, Milan

2013-10-01

The main purpose of this retrospective analysis was to evaluate the incidence and lateralization value of rhythmic ictal nonclonic hand (RINCH) motions in patients with temporal lobe epilepsy (TLE), who were classified as Engel I at least 2 years after epilepsy surgery. We analyzed the distribution of ictal activity at the time of RINCH appearance in patients in whom RINCH motions were present during invasive EEG monitoring. A group of 120 patients was included in this study. In total, we reviewed 491 seizures: 277 seizures in patients with temporal lobe epilepsy (TLE) associated with hippocampal sclerosis (TLE-HS group) and 214 in TLE caused by other lesions (TLE-OTH group). We analyzed 29 patients (79 of the seizures) during invasive EEG monitoring. Fisher's exact test and binomial test were used for the statistical analysis. RINCH motions were observed in 24 out of 120 patients (20%) and in 48 out of 491 seizures (9.8%). There was no significant difference between the occurrence of RINCH motions in patients with TLE-HS and in patients with TLE-OTH, or between gender, right/left-sided TLE, and language dominant/nondominant TLE. RINCH motions were contralateral to the seizure onset in 83.3% of patients and 91.7% of seizures (p=0.0015; p<0.001, respectively). There were no differences in the lateralizing value of RINCH motions in patients with TLE-HS or TLE-OTH. We analyzed RINCH motions in 5 patients/7 seizures during invasive EEG. In all 7 seizures with RINCH motions, we observed the widespread activation of the temporal lobe (mesial and lateral, opercular and polar regions) contralateral to the side of RINCH motions. In all 7 seizures, we observed that at the time of RINCH motion onset, at least 1 explored region of the frontal lobe was affected by the ictal activity. In 3 seizures, we observed time-locked epileptic activation associated with the appearance of RINCH motions, i.e., in the orbitofrontal cortex in 2 seizures and in both the orbitofrontal cortex and anterior cingulate gyrus in 1 seizure. RINCH motions are a relatively frequent ictal sign in patients with TLE. They have a high lateralizing value in these patients, occurring contralateral to the ictal onset. RINCH motions usually occur after the spread of ictal activity beyond the temporal lobe, and their appearance is usually associated with the presence of ictal activity in various regions of the contralateral frontal lobe, mainly the orbitofrontal cortex and anterior cingulate gyrus. This is the first study analysing this phenomenon during invasive EEG recording. Copyright © 2013 Elsevier B.V. All rights reserved.

Fourier transform (FT)-artifacts and power-function resolution filter in Fourier transform mass spectrometry.

PubMed

Kanawati, Basem; Bader, Theresa M; Wanczek, Karl-Peter; Li, Yan; Schmitt-Kopplin, Philippe

2017-10-15

Peak picking algorithms in mass spectrometry face the challenge of picking the correct signals from a mass spectrum. In some cases signal wiggles (side lobes) are also chosen in the produced mass list as if they were real signals. Constraints which are defined in such algorithms do not always guarantee wiggle-free accurate mass list generation out of raw mass spectra. This problem intensifies with acquisitions, which are accompanied by longer transients. Thus, the problem represents a contemporary issue, which propagates with modern high-memory digitizers and exists in both MS and MS/MS spectra. A solariX FTMS mass spectrometer with an Infinity ICR cell (Bruker Daltonics, Bremen, Germany) coupled to a 12 Tesla magnet (Magnex, UK) was used for the experimental study. Time-domain transients of several different data point lengths 512k, 1M, 2M, 4M, 8M were obtained and were Fourier-transformed to obtain frequency spectra which show the effect of the transient truncation on sinc wiggle developments in FT-ICR-MS. MATLAB simulations were also performed to investigate the origin of the Fourier transform (FT)-artifacts. A new filter has been developed to identify and remove FT-artifacts (sinc side lobes) from both frequency and mass spectra. The newly developed filter is based on distinguishing between the FWHM of the correct frequency/mass signals and the FWHM of their corresponding wiggles. The filter draws a reliable confidence limit of resolution range, within which a correct frequency/mass signal is identified. The filter is applicable over a wide mass range of metabolic interest (100-1200 amu). The origin of FT-artifacts due to time-domain transient truncations was thoroughly investigated both experimentally and by simulations in this study. A new solution for this problem with automatic recognition and elimination of these FT-artifacts (side lobes/wiggles) is provided, which is independent of any intensity thresholds, magnetic field strengths and time-domain transient lengths. Copyright © 2017 John Wiley & Sons, Ltd.

Polysplenia syndrome with duodenal and pancreatic dysplasia in a Holstein calf: a case report.

PubMed

Kondoh, Daisuke; Kawano, Tomomi; Kikuchi, Tomoaki; Hatate, Kaoru; Watanabe, Kenichi; Sasaki, Motoki; Yamagishi, Norio; Inokuma, Hisashi; Kitamura, Nobuo

2017-09-29

Laterality disorders of the abdominal organs include situs inversus totalis that mirrors the arrangements of all internal organs and heterotaxy syndrome (situs ambiguus) in which the thoracic or abdominal organs are abnormally arranged. Heterotaxy is often accompanied by multiple congenital malformations, and it generally comprises asplenia and polysplenia syndromes. To our knowledge, polysplenia syndrome has been reported in only three cattle, and computerized tomographic (CT) images of these animals were not obtained. A six-month-old Holstein heifer had ruminal tympani and right abdominal distension. CT imaging showed that the rumen occupied the right side of the abdominal cavity, the omasum and abomasum occupied the left ventral side and the liver was positioned on the left. The colon and cecum were located at the left dorsum of the cavity, and the left kidney was located more cranially than the right. Postmortem findings revealed two spleens attached to the rumen. Significantly, the duodenum was too short to be divided into segments, except the cranial and descending parts, or flexures, except the cranial flexure, and the pancreas, which lacked a left lobe, was covered with mesojejunum. The liver comprised a relatively large right lobe and a small left lobe without quadrate and caudate lobes. The caudal vena cava that connected to the left azygous vein passed irregularly through the aortic hiatus of the diaphragm, and the common hepatic vein without the caudal vena cava passed through the caval foramen. Although the lungs and heart were morphologically normal, the right atrium received three major systemic veins. Polysplenia syndrome was diagnosed based on the CT and postmortem findings. We defined the positions of the abdominal organs and morphological abnormalities in various organs of a calf with polysplenia syndrome based on CT and postmortem findings. These findings will improve understanding of the malpositioning and malformations that can occur in the organs of cattle with polysplenia syndrome.

Distal turbidite fan/lobe succession of the Late Oligocene Zuberec Fm. - architecture and hierarchy (Central Western Carpathians, Orava-Podhale basin)

NASA Astrophysics Data System (ADS)

Starek, Dušan; Fuksi, Tomáš

2017-08-01

A part of the Upper Oligocene sand-rich turbidite systems of the Central Carpathian Basin is represented by the Zuberec Formation. Sand/mud-mixed deposits of this formation are well exposed in the northern part of the basin, allowing us to interpret the turbidite succession as terminal lobe deposits of a submarine fan. This interpretation is based on the discrimination of three facies associations that are comparable to different components of distributive lobe deposits in deep-water fan systems. They correspond to the lobe off-axis, lobe fringe and lobe distal fringe depositional subenvironments, respectively. The inferences about the depositional paleoenvironment based on sedimentological observations are verified by statistical analyses. The bed-thickness frequency distributions and vertical organization of the facies associations show cyclic trends at different hierarchical levels that enable us to reconstruct architectural elements of a turbidite fan. First, small-scale trends correspond with shift in the lobe element centroid between successive elements. Differences in the distribution and frequency of sandstone bed thicknesses as well as differences in the shape of bed-thickness frequency distributions between individual facies associations reflect a gradual fining and thinning in a down-dip direction. Second, meso-scale trends are identified within lobes and they generally correspond to the significant periodicity identified by the time series analysis of the bed thicknesses. The meso-scale trends demonstrate shifts in the position of the lobe centroid within the lobe system. Both types of trends have a character of a compensational stacking pattern and could be linked to autogenic processes. Third, a largescale trend documented by generally thickening-upward stacking pattern of beds, accompanied by a general increase of the sandstones/mudstones ratio and by a gradual change of percentage of individual facies, could be comparable to lobe-system scale. This trend probably indicates a gradual basinward progradation of lobe system controlled by allogenic processes related to tectonic activity of sources and sea-level fluctuations.

Quantification of incidental mediastinal and hilar irradiation delivered during definitive stereotactic body radiation therapy for peripheral non-small cell lung cancer

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

Martin, Kate L.; Gomez, Jorge; Nazareth, Daryl P.

2012-07-01

To determine the amount of incidental radiation dose received by the mediastinal and hilar nodes for patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). Fifty consecutive patients with NSCLC, treated using an SBRT technique, were identified. Of these patients, 38 had a prescription dose of 60 Gy in 20-Gy fractions and were eligible for analysis. For each patient, ipsilateral upper (level 2) and lower (level 4) paratracheal, and hilar (level 10) nodal regions were contoured on the planning computed tomography (CT) images. Using the clinical treatment plan, dose and volume calculations were performed retrospectivelymore » for each nodal region. SBRT to upper lobe tumors resulted in an average total ipsilateral mean dose of between 5.2 and 7.8 Gy for the most proximal paratracheal nodal stations (2R and 4R for right upper lobe lesions, 2L and 4L for left upper lobe lesions). SBRT to lower lobe tumors resulted in an average total ipsilateral mean dose of between 15.6 and 21.5 Gy for the most proximal hilar nodal stations (10R for right lower lobe lesions, 10 l for left lower lobe lesions). Doses to more distal nodes were substantially lower than 5 Gy. The often substantial incidental irradiation, delivered during SBRT for peripheral NSCLC of the lower lobes to the most proximal hilar lymph nodes may be therapeutic for low-volume, subclinical nodal disease. Treatment of peripheral upper lobe lung tumors delivers less incidental irradiation to the paratracheal lymph nodes with lower likelihood of therapeutic benefit.« less

A unified framework for the functional organization of the medial temporal lobes and the phenomenology of episodic memory.

PubMed

Ranganath, Charan

2010-11-01

There is currently an intense debate about the nature of recognition memory and about the roles of medial temporal lobe subregions in recognition memory processes. At a larger level, this debate has been about whether it is appropriate to propose unified theories to explain memory at neural, functional, and phenomenological levels of analysis. Here, I review findings from physiology, functional imaging, and lesion studies in humans, monkeys, and rodents relevant to the roles of medial temporal lobe subregions in recognition memory, as well as in short-term memory and perception. The results from these studies are consistent with the idea that there is functional heterogeneity in the medial temporal lobes, although the differences among medial temporal lobe subregions do not precisely correspond to different types of memory tasks, cognitive processes, or states of awareness. Instead, the evidence is consistent with the idea that medial temporal lobe subregions differ in terms of the kind of information they process and represent, and that these regions collectively support episodic memory by binding item and context information. © 2010 Wiley-Liss, Inc.

Concomitant fractional anisotropy and volumetric abnormalities in temporal lobe epilepsy: cross-sectional evidence for progressive neurologic injury.

PubMed

Keller, Simon S; Schoene-Bake, Jan-Christoph; Gerdes, Jan S; Weber, Bernd; Deppe, Michael

2012-01-01

In patients with temporal lobe epilepsy and associated hippocampal sclerosis (TLEhs) there are brain abnormalities extending beyond the presumed epileptogenic zone as revealed separately in conventional magnetic resonance imaging (MRI) and MR diffusion tensor imaging (DTI) studies. However, little is known about the relation between macroscopic atrophy (revealed by volumetric MRI) and microstructural degeneration (inferred by DTI). For 62 patients with unilateral TLEhs and 68 healthy controls, we determined volumes and mean fractional anisotropy (FA) of ipsilateral and contralateral brain structures from T1-weighted and DTI data, respectively. We report significant volume atrophy and FA alterations of temporal lobe, subcortical and callosal regions, which were more diffuse and bilateral in patients with left TLEhs relative to right TLEhs. We observed significant relationships between volume loss and mean FA, particularly of the thalamus and putamen bilaterally. When corrected for age, duration of epilepsy was significantly correlated with FA loss of an anatomically plausible route - including ipsilateral parahippocampal gyrus and temporal lobe white matter, the thalamus bilaterally, and posterior regions of the corpus callosum that contain temporal lobe fibres - that may be suggestive of progressive brain degeneration in response to recurrent seizures. Chronic TLEhs is associated with interrelated DTI-derived and volume-derived brain degenerative abnormalities that are influenced by the duration of the disorder and the side of seizure onset. This work confirms previously contradictory findings by employing multi-modal imaging techniques in parallel in a large sample of patients.

Measurement of frontal lobe volume and thalamic volume in fetuses with congenital heart disease at different gestational weeks using three dimensional ultra sonography and its clinical value.

PubMed

Li-Fei, Zhu; Hong-Xiong, Liu; Ying, H E

2016-11-01

Our study aimed to investigate the measurement of frontal lobe volume and thalamic volume in fetuses with congenital heart disease (CHD) at different gestational weeks using three dimensional (3-D) ultrasonography and its clinical value. Then, 238 pregnant women who received obstetric ultrasonography in ultrasound department of Internal Medicine of our hospital were enrolled between March 2013 to April 2014. In this study, 85 fetuses were diagnosed to develop CHD by prenatal fetal echocardiography, and the other 153 fetuses were normal. Frontal lobe volume, thalamic volume and cerebral blood flow was determined by color Doppler ultrasonic diagnostic apparatus (type: GE Voluson E8). The level of MCA-PI and CPR in CHD fetus group performed significantly lower than that in normal fetus group (P<0.05), but the level of UA-PI performed significantly higher than that in normal fetus group (P<0.05). When gestational age <30 weeks, there was no significant difference in thalamic volume and frontal lobe volume between the two groups (P<0.05); when gestational age <30 weeks, the level of CHD fetus group performed significantly lower thalamic volume and frontal lobe volume than that in normal fetus group (P<0.05). When gestational age <30 weeks, there was no significant difference in BPD, HC, and GA between the two groups (P<0.05); when gestational age <30 weeks, the level of BPD, HC and GA in CHD fetus group performed significantly lower than that in normal fetus group (P<0.05). If gestational age <30 weeks, CHD performed a small impact on fetal frontal lobe volume and thalamic volume; if gestational age <30 weeks, the level of frontal lobe volume and thalamic volume in fetuses with CHD performed significantly lower than that in normal fetuses.

Temporal lobe volumes in patients with hippocampal sclerosis with or without cortical dysplasia.

PubMed

Diehl, B; Najm, I; LaPresto, E; Prayson, R; Ruggieri, P; Mohamed, A; Ying, Z; Lieber, M; Babb, T; Bingaman, W; Lüders, H O

2004-05-25

Recent MRI-based volume reconstruction studies in intractable temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) suggested atrophy that extends to the adjacent neocortical areas. To study the extent of temporal lobe volume (TLV) abnormalities in patients with pathologically confirmed HS (with or without cortical dysplasia [CD]) who underwent anterior temporal lobectomy for the treatment of drug-resistant TLE. Fifty patients (right TLE: n = 24; left TLE: n = 26) were found to have HS (hippocampal cell loss of >30%). Associated neocortical CD was seen in 20 patients (43%). MRI-based TLVs and hippocampal and hemispheric volume reconstructions in all patients were compared between pathologic groups and with volumes acquired from 10 age-matched control subjects. TLVs ipsilateral to the epileptogenic zone in patients with TLE were smaller than TLVs in control subjects (p < 0.01). In patients with left TLE, TLVs ipsilateral to the epileptogenic zone were smaller than contralateral TLVs (left: 66.6 +/- 8.3 cm3, right: 74.9 +/- 10.0 cm3; p < 0.001). In patients with right TLE, there were no significant asymmetries. The contralateral TLVs (regardless of the side of surgery) were smaller in the HS + CD group than the HS group (HS + CD group: 74.9 +/- 8.6 cm3, HS group: 79.7 +/- 6.6 cm3; p < 0.05). Patients with HS + CD had a tendency to have less hippocampal atrophy and slightly smaller TLVs ipsilateral to the epileptogenic zone, accounting for significantly smaller TLV/hippocampal volume ratios compared with patients with HS alone. Drug-resistant TLE due to HS is associated with extrahippocampal temporal lobe atrophy. The presence of bilateral temporal lobe atrophy is suggestive of a more widespread (bilateral) temporal lobe involvement in patients with HS and CD.

Mesial Temporal Sclerosis: Accuracy of NeuroQuant versus Neuroradiologist.

PubMed

Azab, M; Carone, M; Ying, S H; Yousem, D M

2015-08-01

We sought to compare the accuracy of a volumetric fully automated computer assessment of hippocampal volume asymmetry versus neuroradiologists' interpretations of the temporal lobes for mesial temporal sclerosis. Detecting mesial temporal sclerosis (MTS) is important for the evaluation of patients with temporal lobe epilepsy as it often guides surgical intervention. One feature of MTS is hippocampal volume loss. Electronic medical record and researcher reports of scans of patients with proved mesial temporal sclerosis were compared with volumetric assessment with an FDA-approved software package, NeuroQuant, for detection of mesial temporal sclerosis in 63 patients. The degree of volumetric asymmetry was analyzed to determine the neuroradiologists' threshold for detecting right-left asymmetry in temporal lobe volumes. Thirty-six patients had left-lateralized MTS, 25 had right-lateralized MTS, and 2 had bilateral MTS. The estimated accuracy of the neuroradiologist was 72.6% with a κ statistic of 0.512 (95% CI, 0.315-0.710) [moderate agreement, P < 3 × 10(-6)]), whereas the estimated accuracy of NeuroQuant was 79.4% with a κ statistic of 0.588 (95% CI, 0.388-0.787) [moderate agreement, P < 2 × 10(-6)]). This discrepancy in accuracy was not statistically significant. When at least a 5%-10% volume discrepancy between temporal lobes was present, the neuroradiologists detected it 75%-80% of the time. As a stand-alone fully automated software program that can process temporal lobe volume in 5-10 minutes, NeuroQuant compares favorably with trained neuroradiologists in predicting the side of mesial temporal sclerosis. Neuroradiologists can often detect even small temporal lobe volumetric changes visually. © 2015 by American Journal of Neuroradiology.

The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic Stimulation

ERIC Educational Resources Information Center

Battelli, Lorella; Alvarez, George A.; Carlson, Thomas; Pascual-Leone, Alvaro

2009-01-01

Interhemispheric competition between homologous areas in the human brain is believed to be involved in a wide variety of human behaviors from motor activity to visual perception and particularly attention. For example, patients with lesions in the posterior parietal cortex are unable to selectively track objects in the contralesional side of…

Characterization of Global Near-Nadir Backscatter for Remote Sensing Radar Design

NASA Technical Reports Server (NTRS)

Spencer, Michael W.; Long, David G.

2000-01-01

In order to evaluate side-lobe contamination from the near-nadir region for Ku-Band radars, a statistical characterization of global near-nadir backscatter is constructed. This characterization is performed for a variety of surface types using data from TRMM, Seasat, and Topex. An assessment of the relative calibration accuracy of these sensors is also presented.

Characterization of Global Near-Nadir Backscatter for Remote Sensing Radar Design

NASA Technical Reports Server (NTRS)

Spencer, Michael W.; Long, David G.

2000-01-01

In order to evaluate side-lobe contamination from the near-nadir region for Ku-Band radars, a statistical characterization of global near-nadir backscatter is constructed. This characterization is performed for a variety of surface types using data from TRMM, Seasat, and Topex. An assessment of the relative calibration accuracy of them sensors is also presented.

Laparoscopic left lobe liver resection in a porcine model: a study of the efficacy and safety of different surgical techniques.

PubMed

Eiriksson, Kristinn; Kristinn, Eiriksson; Fors, Diddi; Diddi, Fors; Rubertsson, Sten; Sten, Rubertsson; Arvidsson, Dag; Dag, Arvidsson

2009-05-01

Laparoscopic liver surgery is evolving and the best technique for dividing the liver parenchyma is currently under debate. The aim of this study was to study different techniques during a full laparoscopic lobe resection, and determine the efficacy and risks of bleeding and gas embolism. Sixteen pigs were randomized to two groups: group US underwent an operation with Ultracision shears (AutoSonix) and ultrasonic dissector (CUSA) and group VS with a vessel sealing system (Ligasure) and ultrasonic dissector. A left lobe resection was performed. Transesophageal endoscopic echocardiography (TEE) was used to detect gas emboli in the right side of the heart and pulmonary artery. The operations and TEE were recorded for later assessment. Compared with group VS, group US exhibited significantly more intraoperative bleeding (p = 0.02), a trend towards a longer operation time (p = 0.08), and a trend towards more embolization for grade I emboli. In total, 10 of 15 animals had emboli during the operation. This study showed that a laparoscopic left lobe resection can be performed with a combination of AutoSonix and CUSA as well as with Ligasure and CUSA instrumentation. In our hands, less bleeding was incurred with Ligasure than with AutoSonix.

The Shape and Orientation of the Homunculus Nebula

NASA Astrophysics Data System (ADS)

Davidson, K.; Gull, T. R.; Ishibashi, K.; Hillier, D. J.

2000-12-01

Doppler velocities can be used to trace a cross-section of the bipolar ``Homunculus'' nebula of material ejected from η Car in the giant eruption seen 160 years ago. However, normal ground-based observations have not had sufficient spatial resolution for this task. Data obtained with HST/STIS in March 2000 now provide the first satisfactory results. The configuration's inclination or tilt can be measured reliably, for the first time, by using velocities in the equatorial debris-disk. We find that the angle between bipolar axis and line of sight is close to 41 degrees. Even with excellent data, the bipolar lobe shape is intrinsically difficult to measure. A shape resembling a hot-air balloon fits the data best. Earlier descriptions as ``osculating spheres'' or ``flask-like shapes'' or ``polar caps'' each contain limited elements of truth. The outer or polar parts of each lobe appear to contain more mass than the lobe sides. Our data show interesting structure near the equatorial mid-plane, probably more important than the lobe shapes. In addition to equatorial debris from the great eruption of the 1840's, velocities corresponding to a later ejection time, around 1900, are also present. There are hints of pre-1840 equatorial ejecta too, but these are uncertain. This work is supported by NASA through grant GO-8327 from the STScI.

[Simultanagnosia and scene agnosia induced by right posterior cerebral artery infarction: a case report].

PubMed

Kobayashi, Yasutaka; Muramatsu, Tomoko; Sato, Mamiko; Hayashi, Hiromi; Miura, Toyoaki

2015-01-01

A 68-year-old man was admitted to our hospital for rehabilitation of topographical disorientation. Brain magnetic resonance imaging revealed infarction in the right medial side of the occipital lobe. On neuropsychological testing, he scored low for the visual information-processing task; however, his overall cognitive function was retained. He could identify parts of the picture while describing the context picture of the Visual Perception Test for Agnosia but could not explain the contents of the entire picture, representing so-called simultanagnosia. Further, he could morphologically perceive both familiar and new scenes, but could not identify them, representing so-called scene agnosia. We report this case because simultanagnosia associated with a right occipital lobe lesion is rare.

Depositional patterns of the Mississippi Fan surface: Evidence from GLORIA II and high-resolution seismic profiles

USGS Publications Warehouse

Twichell, David C.; Kenyon, Neil H.; Parson, Lindsay M.; McGregor, Bonnie A.

1991-01-01

GLORIA long-range side-scan sonar imagery and 3.5-kHz seismic-reflection profiles depict a series of nine elongate deposits with generally high-backscatter surfaces covering most of the latest fanlobe sequence of the Mississippi Fan in the eastern Gulf of Mexico. The youngest deposit is a “slump” that covers a 250 by 100 km area of the middle and upper fan. The remaining mapped deposits, termed depositional lobes, are long (as much as 200 km) and relatively thin (less than 35 m thick) bodies. Small channels and lineations on the surface of many of these depositional lobes radiate from a single, larger main channel that is the conduit through which sediment has been supplied to these surficial deposits on the fan. The 3.5-kHz profiles show that adjacent depositional lobes overlap one another rather than interfingering, indicating that only one lobe was an active site of deposition at a time. Shifting of the depositional sites appears to be caused by both aggradation and avulsion. The chronology developed from the overlapping relations indicates the oldest of the mapped depositional lobes are on the lowermost fan, and the youngest are further up the fan. Depositional lobes on the lower fan consist of a series of smaller, elongate features with high-backscatter surfaces (540 km in length) located at the ends of previously unrecognized small channels (< 5 m deep). These small channels extend as much as 120 km from the main channel. Small channelized turbidity currents and/or debris flows, sand flows, or mud flows appear to be the dominant transport process constructing these depositional lobes. Channelized flow is an important mechanism for transporting sediment away from the main channel on this fan and the resulting facies created by these small flows are laterally discontinuous.

Determinants of brain metabolism changes in mesial temporal lobe epilepsy.

PubMed

Chassoux, Francine; Artiges, Eric; Semah, Franck; Desarnaud, Serge; Laurent, Agathe; Landre, Elisabeth; Gervais, Philippe; Devaux, Bertrand; Helal, Ourkia Badia

2016-06-01

To determine the main factors influencing metabolic changes in mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS). We prospectively studied 114 patients with MTLE (62 female; 60 left HS; 15- to 56-year-olds) with (18) F-fluorodeoxyglucose-positron emission tomography and correlated the results with the side of HS, structural atrophy, electroclinical features, gender, age at onset, epilepsy duration, and seizure frequency. Imaging processing was performed using statistical parametric mapping. Ipsilateral hypometabolism involved temporal (mesial structures, pole, and lateral cortex) and extratemporal areas including the insula, frontal lobe, perisylvian regions, and thalamus, more extensively in right HS (RHS). A relative increase of metabolism (hypermetabolism) was found in the nonepileptic temporal lobe and in posterior areas bilaterally. Voxel-based morphometry detected unilateral hippocampus atrophy and gray matter concentration decrease in both frontal lobes, more extensively in left HS (LHS). Regardless of the structural alterations, the topography of hypometabolism correlated strongly with the extent of epileptic networks (mesial, anterior-mesiolateral, widespread mesiolateral, and bitemporal according to the ictal spread), which were larger in RHS. Notably, widespread perisylvian and bitemporal hypometabolism was found only in RHS. Mirror hypermetabolism was grossly proportional to the hypometabolic areas, coinciding partly with the default mode network. Gender-related effect was significant mainly in the contralateral frontal lobe, in which metabolism was higher in female patients. Epilepsy duration correlated with the contralateral temporal metabolism, positively in LHS and negatively in RHS. Opposite results were found with age at onset. High seizure frequency correlated negatively with the contralateral metabolism in LHS. Epileptic networks, as assessed by electroclinical correlations, appear to be the main determinant of hypometabolism in MTLE. Compensatory mechanisms reflected by a relative hypermetabolism in the nonepileptic temporal lobe and in extratemporal areas seem more efficient in LHS and in female patients, whereas long duration, late onset of epilepsy, and high seizure frequency may reduce these adaptive changes. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Detailed anatomy of a deep-water carbonate breccia lobe (Upper Jurassic, French subalpine basin)

NASA Astrophysics Data System (ADS)

Courjault, Thomas; Grosheny, Danièle; Ferry, Serge; Sausse, Judith

2011-06-01

Detailed correlations across Tithonian carbonate breccia deposits in the Drôme River area (northern part of the so-called "Vocontian Through") suggest the depositional system was that of an elongated deep-water lobe, up to 70 km long and 20 to 30 km wide, for a thickness reaching 200 m. The Drôme lobe, as it is now called, is mainly made of slope to basinal mudstones breccias with minor platform components, interpreted as debris flow and mud flow deposits, associated with slump deposits. It is basically a base-of-slope system, whose elongated depositional area implies it was a "point-sourced" gravity system, thus perhaps connected to a small canyon cut onto the western slope of the basin. But the mostly mudstone material of the breccias also suggests that the walls of this inferred canyon were the main supplier of the lobe, not the carbonate platform proper. The updip part of the lobe has a complex internal geometry as the deposition of breccia bed packages is interrupted by scourings locally 50 m-deep, indicating maybe a canyon mouth environment. The middle part of the lobe is dominated by pure vertical aggradation of breccia beds with minor intervening erosion. In the downdip part of the system a morphological compensation mechanism occurs as breccia beds tend to spread laterally. A huge slump carrying large mudstone olistoliths ends the breccia deposition at the beginning of the Berriasian. This megaslump deposit was mostly emplaced on the right side of the breccia lobe supporting the idea of a depositional relief. Our observations thus show that previous interpretations as a submarine canyon infilling or as shallow-water breccias formed in-situ by cyclic loading under attenuating hurricane waves approaching the platform are not consistent with our observations. The internal geometry of the system studied brings new data about a poorly-studied kind of "turbidite" systems that of deep-water carbonate breccias.

A comparison between temporal and subband minimum variance adaptive beamforming

NASA Astrophysics Data System (ADS)

Diamantis, Konstantinos; Voxen, Iben H.; Greenaway, Alan H.; Anderson, Tom; Jensen, Jørgen A.; Sboros, Vassilis

2014-03-01

This paper compares the performance between temporal and subband Minimum Variance (MV) beamformers for medical ultrasound imaging. Both adaptive methods provide an optimized set of apodization weights but are implemented in the time and frequency domains respectively. Their performance is evaluated with simulated synthetic aperture data obtained from Field II and is quantified by the Full-Width-Half-Maximum (FWHM), the Peak-Side-Lobe level (PSL) and the contrast level. From a point phantom, a full sequence of 128 emissions with one transducer element transmitting and all 128 elements receiving each time, provides a FWHM of 0.03 mm (0.14λ) for both implementations at a depth of 40 mm. This value is more than 20 times lower than the one achieved by conventional beamforming. The corresponding values of PSL are -58 dB and -63 dB for time and frequency domain MV beamformers, while a value no lower than -50 dB can be obtained from either Boxcar or Hanning weights. Interestingly, a single emission with central element #64 as the transmitting aperture provides results comparable to the full sequence. The values of FWHM are 0.04 mm and 0.03 mm and those of PSL are -42 dB and -46 dB for temporal and subband approaches. From a cyst phantom and for 128 emissions, the contrast level is calculated at -54 dB and -63 dB respectively at the same depth, with the initial shape of the cyst being preserved in contrast to conventional beamforming. The difference between the two adaptive beamformers is less significant in the case of a single emission, with the contrast level being estimated at -42 dB for the time domain and -43 dB for the frequency domain implementation. For the estimation of a single MV weight of a low resolution image formed by a single emission, 0.44 * 109 calculations per second are required for the temporal approach. The same numbers for the subband approach are 0.62 * 109 for the point and 1.33 * 109 for the cyst phantom. The comparison demonstrates similar resolution but slightly lower side-lobes and higher contrast for the subband approach at the expense of increased computation time.

Task activation and functional connectivity show concordant memory laterality in temporal lobe epilepsy.

PubMed

Sideman, Noah; Chaitanya, Ganne; He, Xiaosong; Doucet, Gaelle; Kim, Na Young; Sperling, Michael R; Sharan, Ashwini D; Tracy, Joseph I

2018-04-01

In epilepsy, asymmetries in the organization of mesial temporal lobe (MTL) functions help determine the cognitive risk associated with procedures such as anterior temporal lobectomy. Past studies have investigated the change/shift in a visual episodic memory laterality index (LI) in mesial temporal lobe structures through functional magnetic resonance imaging (fMRI) task activations. Here, we examine whether underlying task-related functional connectivity (FC) is concordant with such standard fMRI laterality measures. A total of 56 patients with temporal lobe epilepsy (TLE) (Left TLE [LTLE]: 31; Right TLE [RTLE]: 25) and 34 matched healthy controls (HC) underwent fMRI scanning during performance of a scene encoding task (SET). We assessed an activation-based LI of the hippocampal gyrus (HG) and parahippocampal gyrus (PHG) during the SET and its correspondence with task-related FC measures. Analyses involving the HG and PHG showed that the patients with LTLE had a consistently higher LI (right-lateralized) than that of the HC and group with RTLE, indicating functional reorganization. The patients with RTLE did not display a reliable contralateral shift away from the pathology, with the mesial structures showing quite distinct laterality patterns (HG, no laterality bias; PHG, no evidence of LI shift). The FC data for the group with LTLE provided confirmation of reorganization effects, revealing that a rightward task LI may be based on underlying connections between several left-sided regions (middle/superior occipital and left medial frontal gyri) and the right PHG. The FCs between the right HG and left anterior cingulate/medial frontal gyri were also observed in LTLE. Importantly, the data demonstrate that the areas involved in the LTLE task activation shift to the right hemisphere showed a corresponding increase in task-related FCs between the hemispheres. Altered laterality patterns based on mesial temporal lobe epilepsy (MTLE) pathology manifest as several different phenotypes, varying according to side of seizure onset and the specific mesial structures involved. There is good correspondence between task LI activation and FC patterns in the setting of LTLE, suggesting that reliable visual episodic memory reorganization may require both a shift in nodal activation and a change in nodal connectivity with mesial temporal structures involved in memory. Copyright © 2018. Published by Elsevier Inc.

Laurentide glacial landscapes: the role of ice streams

USGS Publications Warehouse

Patterson, C.J.

1998-01-01

Glacial landforms of the North American prairie can be divided into two suites that result from different styles of ice flow: 1) a lowland suite of level-to-streamlined till consistent with formation beneath ice streams, and 2) an upland and lobe-margin suite of thick, hummocky till and glacial thrust blocks consistent with formation at ice-stream and ice-lobe margins. Southern Laurentide ice lobes hypothetically functioned as outlets of ice streams. Broad branching lowlands bounded by escarpments mark the stable positions of the ice streams that fed the lobes. If the lobes and ice streams were similar to modern ice streams, their fast flow was facilitated by high subglacial water pressure. Favorable geology and topography in the midcontinent encouraged nonuniform ice flow and controlled the location of ice streams and outlet lobes.

Noise measurements for various configurations of a model of a mixer nozzle externally blown flap system

NASA Technical Reports Server (NTRS)

Goodykoontz, J. H.; Wagner, J. M.; Sargent, N. B.

1973-01-01

Noise data were taken for variations to a large scale model of an externally blown flap lift augmentation system. The variations included two different mixer nozzles (7 and 8 lobes), two different wing models (2 and 3 flaps), and different lateral distances between the wing chord line and the nozzle centerline. When the seven lobe was used with the trailing flap in the 60 deg position, increasing the wing to nozzle distance had no effect on the sound level. When the eight lobe nozzle was used there was a decrease in sound level. With the 20 deg flap setting the noise level decreased when the distance was increased using either nozzle.

SU-E-J-90: Lobar-Level Lung Ventilation Analysis Using 4DCT and Deformable Image Registration

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

Du, K; Bayouth, J; Patton, T

2015-06-15

Purpose: To assess regional changes in human lung ventilation and mechanics using four-dimensional computed tomography (4DCT) and deformable image registration. This work extends our prior analysis of the entire lung to a lobe-based analysis. Methods: 4DCT images acquired from 20 patients prior to radiation therapy (RT) were used for this analysis. Jacobian ventilation and motion maps were computed from the displacement field after deformable image registration between the end of expiration breathing phase and the end of inspiration breathing phase. The lobes were manually segmented on the reference phase by a medical physicist expert. The voxel-by-voxel ventilation and motion magnitudemore » for all subjects were grouped by lobes and plotted into cumulative voxel frequency curves respectively. In addition, to eliminate the effect of different breathing efforts across subjects, we applied the inter-subject equivalent lung volume (ELV) method on a subset of the cohort and reevaluated the lobar ventilation. Results: 95% of voxels in the lung are expanding during inspiration. However, some local regions of lung tissue show far more expansion than others. The greatest expansion with respiration occurs within the lower lobes; between exhale and inhale the median expansion in lower lobes is approximately 15%, while the median expansion in upper lobes is 10%. This appears to be driven by a subset of lung tissues within the lobe that have greater expansion; twice the number of voxels in the lower lobes (20%) expand by > 30% when compared to the upper lobes (10%). Conclusion: Lung ventilation and motion show significant difference on the lobar level. There are different lobar fractions of driving voxels that contribute to the major expansion of the lung. This work was supported by NIH grant CA166703.« less

FOURTH SEMINAR TO THE MEMORY OF D.N. KLYSHKO: Algebraic solution of the synthesis problem for coded sequences

NASA Astrophysics Data System (ADS)

Leukhin, Anatolii N.

2005-08-01

The algebraic solution of a 'complex' problem of synthesis of phase-coded (PC) sequences with the zero level of side lobes of the cyclic autocorrelation function (ACF) is proposed. It is shown that the solution of the synthesis problem is connected with the existence of difference sets for a given code dimension. The problem of estimating the number of possible code combinations for a given code dimension is solved. It is pointed out that the problem of synthesis of PC sequences is related to the fundamental problems of discrete mathematics and, first of all, to a number of combinatorial problems, which can be solved, as the number factorisation problem, by algebraic methods by using the theory of Galois fields and groups.

A method to improve the range resolution in stepped frequency continuous wave radar

NASA Astrophysics Data System (ADS)

Kaczmarek, Paweł

2018-04-01

In the paper one of high range resolution methods - Aperture Sampling - was analysed. Unlike MUSIC based techniques it proved to be very efficient in terms of achieving unambiguous synthetic range profile for ultra-wideband stepped frequency continuous wave radar. Assuming that minimal distance required to separate two targets in depth (distance) corresponds to -3 dB width of received echo, AS provided a 30,8 % improvement in range resolution in analysed scenario, when compared to results of applying IFFT. Output data is far superior in terms of both improved range resolution and reduced side lobe level than used typically in this area Inverse Fourier Transform. Furthermore it does not require prior knowledge or an estimate of number of targets to be detected in a given scan.

Effects of surgical side and site on psychological symptoms following epilepsy surgery in adults.

PubMed

Prayson, Brigid E; Floden, Darlene P; Ferguson, Lisa; Kim, Kevin H; Jehi, Lara; Busch, Robyn M

2017-03-01

This retrospective study examined the potential role of side and site of surgery in psychological symptom change after epilepsy surgery and determined the base rate of psychological change at the individual level. Two-hundred twenty-eight adults completed the Personality Assessment Inventory (PAI) before and after temporal (TLR; n=190) or frontal lobe resection (FLR; n=38). Repeated measures ANOVAs with bootstrapping examined differences in psychological outcome as a function of surgical site separately in patients who underwent left- versus right-sided resections. Individual's PAI score changes were then used to determine the prevalence of clinically meaningful postoperative symptom change. Following left-sided resections, there were significant group-by-time interactions on Somatic Complaints, Anxiety, and Anxiety Related Disorders. There was also a trend in this direction on the Depression scale. TLR patients endorsed greater preoperative symptoms than FLR patients on all of these scales, except the Somatic Complaints scale. After surgery, TLR patients reported symptom improvement on all four scales, while scores of FLR patients remained relatively stable over time. Endorsement of Mania-related symptoms increased in both TLR and FLR groups from pre-to post-surgical testing. Following right-sided resections, both groups endorsed symptom improvements on Somatic Complaints, Anxiety, and Depression scales following surgery. In addition, the TLR group endorsed more Mania-related symptoms than the FLR group regardless of time. Patterns of meaningful change in individual patients were generally consistent with group findings, with the most frequent improvements observed following TLR. However, there were a small subset of patients who reported symptom exacerbation after surgery. Our results suggest that surgical lateralization and localization are important factors in postoperative psychological outcome and highlight the importance of considering psychological change at the individual patient level. Further research is needed to identify potential risk factors for symptom exacerbation to aid in preoperative counseling and identify those patients most in need of postoperative psychological surveillance. Copyright © 2016 Elsevier Inc. All rights reserved.

Headache Following Occipital Brain Lesion: A Case of Migraine Triggered by Occipital Spikes?

PubMed

Vollono, Catello; Mariotti, Paolo; Losurdo, Anna; Giannantoni, Nadia Mariagrazia; Mazzucchi, Edoardo; Valentini, Piero; De Rose, Paola; Della Marca, Giacomo

2015-10-01

This study describes the case of an 8-year-old boy who developed a genuine migraine after the surgical excision, from the right occipital lobe, of brain abscesses due to selective infestation of the cerebrum by Entamoeba histolytica. After the surgical treatment, the boy presented daily headaches with typical migraine features, including right-side parieto-temporal pain, nausea, vomiting, and photophobia. Electroencephalography (EEG) showed epileptiform discharges in the right occipital lobe, although he never presented seizures. Clinical and neurophysiological observations were performed, including video-EEG and polygraphic recordings. EEG showed "interictal" epileptiform discharges in the right occipital lobe. A prolonged video-EEG recording performed before, during, and after an acute attack ruled out ictal or postictal migraine. In this boy, an occipital lesion caused occipital epileptiform EEG discharges without seizures, probably prevented by the treatment. We speculate that occipital spikes, in turn, could have caused a chronic headache with features of migraine without aura. Occipital epileptiform discharges, even in absence of seizures, may trigger a genuine migraine, probably by means of either the trigeminovascular or brainstem system. © EEG and Clinical Neuroscience Society (ECNS) 2014.

[Diagnosis and surgical treatment of cystic pulmonary hypoplasia with aortic blood supply].

PubMed

Opanasenko, N S; Klimenko, V I; Kshanovskiĭ, A É; Tereshkovich, A V; Kalenichenko, M I; Konik, B N; Demus, R S; Obremskaia, O K; Levanda, L I; Kononenko, V A; Mikitenko, I Iu

2013-12-01

Cystic pulmonary hypoplasia with aortic blood supply--it is a rare inborn failure, in which the part of pulmonary tissue is developing separately from tracheo-bronchial tree and takes blood supply from systemic blood circulation. Diagnosis of the disease is a complicated, and it is necessary to apply modern radiological methods of visualization. The results of treatment of 27 patients, suffering cystic pulmonary hypoplasia with aortic blood supply, in the clinic through 50 yrs, were analyzed. All the patients were operated on.In 17 (63%) patients lobectomy was performed, in 4 (14.8%)--the left-sided lower lobe pyramid was excised, in 1 (3.7%)--the left-sided wedge resection of C(X), in 1 (3.7%)--the left-sided pulmonectomy, in 1 (3.7%)--left-sided resection of C(VIII) - C(IX). The rate of intraoperative complications--14.8%, and postoperative--7.4%. Efficacy of surgical treatment for this period constitutes 100%.

Photogrammetric and Global Positioning System Measurements of Active Pahoehoe Lava Lobe Emplacement on Kilauea, Hawaii

NASA Technical Reports Server (NTRS)

Hamilton, Christopher W.; Glaze, Lori S.; James, Mike R.; Baloga, Stephen M.; Fagents, Sarah A.

2012-01-01

Basalt is the most common rock type on the surface of terrestrial bodies throughout the solar system and -- by total volume and areal coverage -- pahoehoe flows are the most abundant form of basaltic lava in subaerial and submarine environments on Earth. A detailed understanding of pahoehoe emplacement processes is necessary for developing accurate models of flow field development, assessing hazards associated with active lava flows, and interpreting the significance of lava flow morphology on Earth and other planetary bodies. Here, we examine the active emplacement of pahoehoe lobes along the margins of the Hook Flow from Pu'u 'O'o on Kilauea, Hawaii. Topographic data were acquired between 21 and 23 February 2006 using stereo-imaging and differential global positing system (DGPS) measurements. During this time, the average discharge rate for the Hook Flow was 0.01-0.05 cubic m/s. Using stereogrammetric point clouds and interpolated digital terrain models (DTMs), active flow fronts were digitized at 1 minute intervals. These areal spreading maps show that the lava lobe grew by a series of breakouts tha t broadly fit into two categories: narrow (0.2-0.6 m-wide) toes that grew preferentially down-slope, and broad (1.4-3.5 m-wide) breakouts that formed along the sides of the lobe, nearly perpendicular to the down-flow axis. These lobes inflated to half of their final thickness within approx 5 minutes, with a rate of inflation that generally deceased with time. Through a combination of down-slope and cross-slope breakouts, lobes developed a parabolic cross-sectional shape within tens of minutes. We also observed that while the average local discharge rate for the lobe was generally constant at 0.0064 +/- 0.0019 cubic m/s, there was a 2 to 6 fold increase in the areal coverage rate every 4.1 +/- 0.6 minutes. We attribute this periodicity to the time required for the dynamic pressurization of the liquid core of the lava lobe to exceed the cooling-induced strength of the lobe margins. Using DGPS-derived DTMs of the topography before and after pahoehoe lobe emplacement, we observed that the lava typically concentrated within existing topographic lows, with the lobe reaching a maximum thickness of approx 1.2 m above the lowest points of the initial topography and above reverse-facing slopes. Lobe margins were typically controlled by high-standing topography, with the zone directly adjacent to the final flow margin having average relief that is approx 4 cm higher than the lava-inundated region. This suggests that irregularities approx 25% of the height of the smallest breakout elements (i.e., toes) can exert a strong control on the paths of low-discharge pahoehoe lobes, with stagnated toes forming confining margins that allow interior portions of flow to topographically invert the landscape by inflation.

Concomitant Fractional Anisotropy and Volumetric Abnormalities in Temporal Lobe Epilepsy: Cross-Sectional Evidence for Progressive Neurologic Injury

PubMed Central

Gerdes, Jan S.; Weber, Bernd; Deppe, Michael

2012-01-01

Background In patients with temporal lobe epilepsy and associated hippocampal sclerosis (TLEhs) there are brain abnormalities extending beyond the presumed epileptogenic zone as revealed separately in conventional magnetic resonance imaging (MRI) and MR diffusion tensor imaging (DTI) studies. However, little is known about the relation between macroscopic atrophy (revealed by volumetric MRI) and microstructural degeneration (inferred by DTI). Methodology/Principal Findings For 62 patients with unilateral TLEhs and 68 healthy controls, we determined volumes and mean fractional anisotropy (FA) of ipsilateral and contralateral brain structures from T1-weighted and DTI data, respectively. We report significant volume atrophy and FA alterations of temporal lobe, subcortical and callosal regions, which were more diffuse and bilateral in patients with left TLEhs relative to right TLEhs. We observed significant relationships between volume loss and mean FA, particularly of the thalamus and putamen bilaterally. When corrected for age, duration of epilepsy was significantly correlated with FA loss of an anatomically plausible route - including ipsilateral parahippocampal gyrus and temporal lobe white matter, the thalamus bilaterally, and posterior regions of the corpus callosum that contain temporal lobe fibres - that may be suggestive of progressive brain degeneration in response to recurrent seizures. Conclusions/Significance Chronic TLEhs is associated with interrelated DTI-derived and volume-derived brain degenerative abnormalities that are influenced by the duration of the disorder and the side of seizure onset. This work confirms previously contradictory findings by employing multi-modal imaging techniques in parallel in a large sample of patients. PMID:23071638

[A case of traumatic middle meningeal arteriovenous fistula on the side of the head opposite to the injured side].

PubMed

Takeuchi, Satoru; Takasato, Yoshio; Masaoka, Hiroyuki; Hayakawa, Takanori; Otani, Naoki; Yoshino, Yoshikazu; Yatsushige, Hiroshi; Sugawara, Takashi; Aoyagi, Chikashi; Suzuki, Go

2009-10-01

A rare case of a traumatic middle meningeal arteriovenous fistula on the side of the head opposite to the injured side was reported. A 21-year-old man was admitted to our hospital after a traffic accident in which the right side of his head was hit. CT scans and MR images on admission showed a right temporal bone fracture, traumatic subarachnoid hemorrhage, and a left frontal lobe contusion. Three months after the head injury, he complained of tinnitus and exophthalmos. One year after the head injury, left external carotid angiograms showed a dural arteriovenous fistula fed by the left dilated middle meningeal artery and draining into the middle meningeal vein. Early filling of the sphenoparietal sinus, cavernous sinus, superior ophthalmic vein, and the cortical vein were also detected. Transarterial embolization of the left middle meningeal fistula was performed, resulting in the disappearance of the lesion. The postoperative course was uneventful.

Histopathological changes associated with high intensity focused ultrasound (HIFU) treatment for localised adenocarcinoma of the prostate

PubMed Central

Van Leenders, G J L H; Beerlage, H; Ruijter, E; de la Rosette, J J M C H; van de Kaa, C A

2000-01-01

Aims—Investigation of the histopathological changes in prostatectomy specimens of patients with prostate cancer after high intensity focused ultrasound (HIFU) and identification of immunohistochemical markers for tissue damage after HIFU treatment. Methods—Nine patients diagnosed with adenocarcinoma of the prostate underwent unilateral HIFU treatment seven to 12 days before radical prostatectomy. The prostatectomy specimens were analysed histologically. Immunohistochemical staining and electron microscopy were performed to characterise more subtle phenotypic changes. Results—All prostatectomy specimens revealed well circumscribed HIFU lesions at the dorsal side of the prostate lobe treated. Most epithelial glands in the centre of the HIFU lesions revealed signs of necrosis. Glands without apparently necrotic features were also situated in the HIFU lesions, raising the question of whether lethal destruction had occurred. This epithelium reacted with antibodies to pancytokeratin, prostate specific antigen (PSA), and Ki67, but did not express cytokeratin 8, which is indicative of severe cellular damage. Ultrastructural examination revealed disintegration of cellular membranes and cytoplasmic organelles consistent with cell necrosis. HIFU treatment was incomplete at the ventral, lateral, and dorsal sides of the prostate lobe treated. Conclusions—HIFU treatment induces a spectrum of morphological changes ranging from apparent light microscopic necrosis to more subtle ultrastructural cell damage. All HIFU lesions are marked by loss of cytokeratin 8. HIFU does not affect the whole area treated, leaving vital tissue at the ventral, lateral, and dorsal sides of the prostate. Key Words: prostate cancer • high intensity focused ultrasound treatment PMID:10889823

Complex Pupil Masks for Aberrated Imaging of Closely Spaced Objects

NASA Astrophysics Data System (ADS)

Reddy, A. N. K.; Sagar, D. K.; Khonina, S. N.

2017-12-01

Current approach demonstrates the suppression of optical side-lobes and the contraction of the main lobe in the composite image of two object points of the optical system under the influence of defocusing effect when an asymmetric phase edges are imposed over the apodized circular aperture. The resolution of two point sources having different intensity ratio is discussed in terms of the modified Sparrow criterion, functions of the degree of coherence of the illumination, the intensity difference and the degree of asymmetric phase masking. Here we have introduced and explored the effects of focus aberration (defect-of-focus) on the two-point resolution of the optical systems. Results on the aberrated composite image of closely spaced objects with amplitude mask and asymmetric phase masks forms a significant contribution in astronomical and microscopic observations.

Risk to verbal memory following anterior temporal lobectomy in patients with severe left-sided hippocampal sclerosis.

PubMed

Martin, Roy C; Kretzmer, Tracy; Palmer, Cheryl; Sawrie, Stephen; Knowlton, Robert; Faught, Edward; Morawetz, Richard; Kuzniecky, Ruben

2002-12-01

Previous investigations indicate low risk for memory loss following anterior temporal lobectomy (ATL) in patients with severe hippocampal sclerosis (HS) compared with patients with mild HS. However, these conclusions have been established primarily with group-level analyses. To investigate individual base rate risk for verbal memory loss following ATL in patients who have pathologically verified mild, moderate, or severe HS. One hundred fifteen patients with unilateral temporal lobe epilepsy (68 with left-sided and 47 with right-sided epilepsy) were included. Acquisition, retrieval, and recognition components of verbal memory, as measured by the California Verbal Learning Test, were assessed before and after ATL. Postoperatively, the degree of neuronal loss and reactive gliosis of the hippocampus was assessed via a 3-tiered rating system establishing mild, moderate, and severe pathologic features. Patients with preoperative magnetic resonance imaging-based evidence of lesions outside the mesial temporal area (side of surgical resection) were excluded. Neither seizure laterality nor severity of HS was associated with preoperative verbal memory performance. Postoperatively, the left-sided ATL group demonstrated significant decline across the acquisition (P<.01), retrival (P<.001), and recognition (P<.001) verbal memory components compared with the right-sided ATL group. Patients who underwent left-sided ATL and had mild HS displayed the largest magnitude and percentage proportion of postoperative decline across all verbal memory components. However, 28 (48%) of the 58 patients who underwent left-sided ATL and who had moderate and severe HS displayed statistically reliable declines on retrieval aspects of verbal memory. Most patients undergoing right-sided ATL, regardless of the extent of hippocampal pathologic features, displayed no postoperative memory change. Substantial individual heterogeneity of memory outcome exists across groups of patients undergoing ATL, with various degrees of pathologically verified HS. Patients undergoing left-sided ATL who have mild HS seem at greatest risk for broad-spectrum verbal memory decline. However, when examining outcome on a patient-by-patient basis, many patients undergoing left-sided ATL who have moderate to severe HS were also vulnerable to verbal memory loss. This risk seems selective to a retrieval-based aspect of verbal memory.

A critical examination of bifrontal electroconvulsive therapy: clinical efficacy, cognitive side effects, and directions for future research.

PubMed

Crowley, Kevin; Pickle, Jody; Dale, Roman; Fattal, Omar

2008-12-01

Bifrontal (BF) electroconvulsive therapy (ECT), although researched less extensively than bitemporal (BT) or right unilateral (RUL) ECT, has been suggested to be comparable to the other 2 electrode placements with respect to clinical efficacy while resulting in less cognitive impairment than BT ECT. Imaging studies have indicated that seizures induced by BF ECT affect the brain differently than BT or RUL ECT, in that BF ECT increases cerebral blood flow in the frontal lobes more intensely than either of the other 2 placements. Therefore, it is possible that the cognitive impairment manifested after a course of BF ECT could also be different than the impairment seen with BT and RUL ECT. Research conducted on cognitive impairment from BF ECT to date has been inadequate due to the use of nonspecific cognitive measures (such as the Mini-Mental Status Examination) or an inordinate focus on memory functioning (which is believed to be mostly subsumed in the temporal lobes). Because BF ECT increases cerebral blood flow in the frontal lobes more intensely than either of the other placements, research must instead focus on investigating the possible effects of BF ECT on executive functioning, which is believed to be subsumed in the frontal lobes. This is especially important because of the established relationship between executive dysfunction and depression and also because of the increasing popularity of BF ECT.

The regional association between bronchiectasis and lung cancer in chest CT.

PubMed

Kim, Yeon Wook; Lee, Chang-Hoon; Jin, Kwang-Nam; Lee, Jung-Kyu; Heo, Eun Young; Park, Sung Soo; Chung, Hee Soon; Kim, Deog Kyeom

2016-11-15

Limited studies have examined the association between lung cancer and bronchiectasis (BE). This study evaluated the regional association between BE and lung cancer by analyzing the lobar location of lung cancer in patients with underlying BE. This clustered multi-level study enrolled patients who had underlying BE and were newly diagnosed with lung cancer between January 1, 2010 and May 30, 2013 in two referral hospitals in South Korea. By analyzing the presence of lung cancer and underlying BE as event variables at the level of lung lobes on chest computed tomography (CT), we evaluated the association of BE and lung cancer by the locations of the diseases. Eighty-one patients with BE and combined lung cancer were enrolled. Within 486 lung lobes of the patients, combined BE and lung cancer in the same lobe was found in 11 lobes (2.3 %). Using the general estimating equation assuming BE as a risk factor of lung cancer, the results indicated that the prevalence of lung cancer was significantly lower in the lobes with pre-existing BE (β = -1.09, p-value = 0.001). Regionally, pre-existing BE was associated with a lower risk of the occurrence of lung cancer in the same lobe.

[One-stage Operation through the Same Skin Incision for Synchronous Double Primary Breast and Lung Cancer;Report of a Case].

PubMed

Takahashi, Noriyuki; Kuga, Yoko; Uno, Satoko; Saito, Keita

2018-02-01

A 75-year-old woman noticed a small mass in the right side breast and consulted our hospital. The results of the detailed examination indicated the synchronous double primary right breast cancer and the same side lung cancer (rS5). One-stage operation from the same skin incision was scheduled. Volume rendering (VR) of computed tomography (CT)-scan was very useful in deciding the position and the length of the skin incision. The breast tumor resection and the right middle lobe resection were successfully performed through 6.5 cm skin incision.

Selective amygdalohippocampectomy versus standard temporal lobectomy in patients with mesiotemporal lobe epilepsy and unilateral hippocampal sclerosis: post-operative facial emotion recognition abilities.

PubMed

Wendling, Anne-Sophie; Steinhoff, Bernhard J; Bodin, Frédéric; Staack, Anke M; Zentner, Josef; Scholly, Julia; Valenti, Maria-Paula; Schulze-Bonhage, Andreas; Hirsch, Edouard

2015-03-01

Surgical treatment of mesial temporal lobe epilepsy (mTLE) patients involves the removal either of the left or the right hippocampus. Since the mesial temporal lobe is responsible for emotion recognition abilities, we aimed to assess facial emotion recognition (FER) in two homogeneous patient cohorts that differed only in the administered surgery design since anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy (SAH) were performed independently of the underlying electroclinical conditions. The patient selection for the two respective surgical procedures was carried out retrospectively between 2000 and 2009 by two independent epilepsy centres, the Kork Epilepsy Centre, Germany and the University Hospital of Strasbourg, France. All included patients had presented with unilateral hippocampus sclerosis (HS) without associated dysplasia or white matter blurring and had become seizure-free postoperatively. Psychometric evaluation was carried out with the Ekman 60 Faces Test and screened for depression and psychosomatic symptoms with the SCL-90 R and the BDI. Thirty healthy volunteers participated as control subjects. Sixty patients were included, 27 had undergone SAH and 33 ATL. Patients and controls obtained comparable scores in FER for surprise, happiness, anger and sadness. Concerning fear and disgust the patient group scored significantly worse. Left-sided operations led to the the most pronounced impairment. The ATL group scored significantly worse for recognition of fear compared with SAH patients. Inversely, after SAH scores for disgust were significantly lower than after ATL, independently of the side of resection. Unilateral temporal damage impairs FER. Different neurosurgical procedures may affect FER differently. Copyright © 2015 Elsevier B.V. All rights reserved.

Neuronal Injury and Glial Changes Are Hallmarks of Open Field Blast Exposure in Swine Frontal Lobe

PubMed Central

Kallakuri, Srinivasu; Desai, Alok; Feng, Ke; Tummala, Sharvani; Saif, Tal; Chen, Chaoyang; Zhang, Liying; Cavanaugh, John M.; King, Albert I.

2017-01-01

With the rapid increase in the number of blast induced traumatic brain injuries and associated neuropsychological consequences in veterans returning from the operations in Iraq and Afghanistan, the need to better understand the neuropathological sequelae following exposure to an open field blast exposure is still critical. Although a large body of experimental studies have attempted to address these pathological changes using shock tube models of blast injury, studies directed at understanding changes in a gyrencephalic brain exposed to a true open field blast are limited and thus forms the focus of this study. Anesthetized, male Yucatan swine were subjected to forward facing medium blast overpressure (peak side on overpressure 224–332 kPa; n = 7) or high blast overpressure (peak side on overpressure 350–403 kPa; n = 5) by detonating 3.6 kg of composition-4 charge. Sham animals (n = 5) were subjected to all the conditions without blast exposure. After a 3-day survival period, the brain was harvested and sections from the frontal lobes were processed for histological assessment of neuronal injury and glial reactivity changes. Significant neuronal injury in the form of beta amyloid precursor protein immunoreactive zones in the gray and white matter was observed in the frontal lobe sections from both the blast exposure groups. A significant increase in the number of astrocytes and microglia was also observed in the blast exposed sections compared to sham sections. We postulate that the observed acute injury changes may progress to chronic periods after blast and may contribute to short and long-term neuronal degeneration and glial mediated inflammation. PMID:28107370

On the right side? A longitudinal study of left- versus right-lateralized semantic dementia.

PubMed

Kumfor, Fiona; Landin-Romero, Ramon; Devenney, Emma; Hutchings, Rosalind; Grasso, Roberto; Hodges, John R; Piguet, Olivier

2016-03-01

The typical presentation of semantic dementia is associated with marked, left predominant anterior temporal lobe atrophy and with changes in language. About 30% of individuals, however, present with predominant right anterior temporal lobe atrophy, usually accompanied by behavioural changes and prosopagnosia. Here, we aimed to establish whether these initially distinct clinical presentations evolve into a similar syndrome at the neural and behavioural level. Thirty-one patients who presented with predominant anterior temporal lobe atrophy were included. Based on imaging, patients were categorized as either predominant left (n = 22) or right (n = 9) semantic dementia. Thirty-three Alzheimer's disease patients and 25 healthy controls were included for comparison. Participants completed the Addenbrooke's Cognitive Examination, a Face and Emotion Processing Battery and the Cambridge Behavioural Inventory, and underwent magnetic resonance imaging annually. Longitudinal neuroimaging analyses showed greater right temporal pole atrophy in left semantic dementia than Alzheimer's disease, whereas right semantic dementia showed greater orbitofrontal and left temporal lobe atrophy than Alzheimer's disease. Importantly, direct comparisons between semantic dementia groups revealed that over time, left semantic dementia showed progressive thinning in the right temporal pole, whereas right semantic dementia showed thinning in the orbitofrontal cortex and anterior cingulate. Behaviourally, longitudinal analyses revealed that general cognition declined in all patients. In contrast, patients with left and right semantic dementia showed greater emotion recognition decline than Alzheimer's disease. In addition, left semantic dementia showed greater motivation loss than Alzheimer's disease. Correlational analyses revealed that emotion recognition was associated with right temporal pole, right medial orbitofrontal and right fusiform integrity, while changes in motivation were associated with right temporal pole cortical thinning. While left and right semantic dementia show distinct profiles at presentation, both phenotypes develop deficits in emotion recognition and behaviour. These findings highlight the pervasive socio-emotional deficits in frontotemporal dementia, even in patients with an initial language presentation. These changes reflect right anterior temporal and orbitofrontal cortex degeneration, underscoring the role of these regions in social cognition and behaviour. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Levels of processing with free and cued recall and unilateral temporal lobe epilepsy.

PubMed

Lespinet-Najib, Véronique; N'Kaoua, Bernard; Sauzéon, Hélène; Bresson, Christel; Rougier, Alain; Claverie, Bernard

2004-04-01

This study investigates the role of the temporal lobes in levels-of-processing tasks (phonetic and semantic encoding) according to the nature of recall tasks (free and cued recall). These tasks were administered to 48 patients with unilateral temporal epilepsy (right "RTLE"=24; left "LTLE"=24) and a normal group (n=24). The results indicated that LTLE patients were impaired for semantic processing (free and cued recall) and for phonetic processing (free and cued recall), while for RTLE patients deficits appeared in free recall with semantic processing. It is suggested that the left temporal lobe is involved in all aspects of verbal memory, and that the right temporal lobe is specialized in semantic processing. Moreover, our data seem to indicate that RTLE patients present a retrieval processing impairment (semantic condition), whereas the LTLE group is characterized by encoding difficulties in the phonetic and semantic condition.

Analysis of Satellite Communications Antenna Patterns

NASA Technical Reports Server (NTRS)

Rahmat-Samii, Y.

1985-01-01

Computer program accurately and efficiently predicts far-field patterns of offset, or symmetric, parabolic reflector antennas. Antenna designer uses program to study effects of varying geometrical and electrical (RF) parameters of parabolic reflector and its feed system. Accurate predictions of far-field patterns help designer predict overall performance of antenna. These reflectors used extensively in modern communications satellites and in multiple-beam and low side-lobe antenna systems.

Visuo-spatial memory deficits following medial temporal lobe damage: A comparison of three patient groups.

PubMed

Esfahani-Bayerl, Nazli; Finke, Carsten; Braun, Mischa; Düzel, Emrah; Heekeren, Hauke R; Holtkamp, Martin; Hasper, Dietrich; Storm, Christian; Ploner, Christoph J

2016-01-29

The contributions of the hippocampal formation and adjacent regions of the medial temporal lobe (MTL) to memory are still a matter of debate. It is currently unclear, to what extent discrepancies between previous human lesion studies may have been caused by the choice of distinct patient models of MTL dysfunction, as disorders affecting this region differ in selectivity, laterality and mechanisms of post-lesional compensation. Here, we investigated the performance of three distinct patient groups with lesions to the MTL with a battery of visuo-spatial short-term memory tasks. Thirty-one subjects with either unilateral damage to the MTL (postsurgical lesions following resection of a benign brain tumor, 6 right-sided lesions, 5 left) or bilateral damage (10 post-encephalitic lesions, 10 post-anoxic lesions) performed a series of tasks requiring short-term memory of colors, locations or color-location associations. We have shown previously that performance in the association task critically depends on hippocampal integrity. Patients with postsurgical damage of the MTL showed deficient performance in the association task, but performed normally in color and location tasks. Patients with left-sided lesions were almost as impaired as patients with right-sided lesions. Patients with bilateral post-encephalitic lesions showed comparable damage to MTL sub-regions and performed similarly to patients with postsurgical lesions in the association task. However, post-encephalitic patients showed additional impairments in the non-associative color and location tasks. A strikingly similar pattern of deficits was observed in post-anoxic patients. These results suggest a distinct cerebral organization of associative and non-associative short-term memory that was differentially affected in the three patient groups. Thus, while all patient groups may provide appropriate models of medial temporal lobe dysfunction in associative visuo-spatial short-term memory, additional deficits in non-associative memory tasks likely reflect damage of regions outside the MTL. Importantly, the choice of a patient model in human lesion studies of the MTL significantly influences overall performance patterns in visuo-spatial memory tasks. Copyright © 2015 Elsevier Ltd. All rights reserved.

Treating autism by targeting the temporal lobes.

PubMed

Chi, Richard P; Snyder, Allan W

2014-11-01

Compelling new findings suggest that an early core signature of autism is a deficient left anterior temporal lobe response to language and an atypical over-activation of the right anterior temporal lobe. Intriguingly, our recent results from an entirely different line of reasoning and experiments also show that applying cathodal stimulation (suppressing) at the left anterior temporal lobe together with anodal stimulation (facilitating) at the right anterior temporal lobe, by transcranial direct current stimulation (tDCS), can induce some autistic-like cognitive abilities in otherwise normal adults. If we could briefly induce autistic like cognitive abilities in healthy individuals, it follows that we might be able to mitigate some autistic traits by reversing the above stimulation protocol, in an attempt to restore the typical dominance of the left anterior temporal lobe. Accordingly, we hypothesize that at least some autistic traits can be mitigated, by applying anodal stimulation (facilitating) at the left anterior temporal lobe together with cathodal stimulation (suppressing) at the right anterior temporal lobe. Our hypothesis is supported by strong convergent evidence that autistic symptoms can emerge and later reverse due to the onset and subsequent recovery of various temporal lobe (predominantly the left) pathologies. It is also consistent with evidence that the temporal lobes (especially the left) are a conceptual hub, critical for extracting meaning from lower level sensory information to form a coherent representation, and that a deficit in the temporal lobes underlies autistic traits. Copyright © 2014 Elsevier Ltd. All rights reserved.

Levels of Processing with Free and Cued Recall and Unilateral Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Lespinet-Najib, Veronique; N'Kaoua, Bernard; Sauzeon, Helene; Bresson, Christel; Rougier, Alain; Claverie, Bernard

2004-01-01

This study investigates the role of the temporal lobes in levels-of-processing tasks (phonetic and semantic encoding) according to the nature of recall tasks (free and cued recall). These tasks were administered to 48 patients with unilateral temporal epilepsy (right ''RTLE''=24; left ''LTLE''=24) and a normal group (n=24). The results indicated…

Restricted growth and insulin-like growth factor-1 deficiency in mice lacking presenilin-1 in the neural crest cell lineage

PubMed Central

Nakajima, Mitsunari; Watanabe, Sono; Okuyama, Satoshi; Shen, Jie; Furukawa, Yoshiko

2012-01-01

Presenilin-1 (PS1) is a transmembrane protein that is in many cases responsible for the development of early-onset familial Alzheimer’s disease. PS1 is essential for neurogenesis, somitogenesis, angiogenesis, and cardiac morphogenesis. We report here that PS1 is also required for maturation and/or maintenance of the pituitary gland. We generated PS1-conditional knockout (PS1-cKO) mice by crossing floxed PS1 and Wnt1-cre mice, in which PS1 was lacking in the neural crest-derived cell lineage. Although the PS1-cKO mice exhibited no obvious phenotypic abnormalities for several days after birth, reduced body weight in the mutant was evident by the age of 3 to 5 weeks. Pituitary weight and serum insulin-like growth factor (IGF)-1 level were also reduced in the mutant. Histologic analysis revealed severe atrophy of the cytosol in the anterior and intermediate pituitary lobes of the mutant. Immunohistochemistry did not reveal clear differences in the expression levels of thyroid-stimulating hormone, adrenocorticotropic hormone, or prolactin in the mutant pituitary. In contrast, growth hormone expression levels were reduced in the anterior lobe of the mutant. PS1 was defective in the posterior lobe, but not the anterior or intermediate lobes, in the mutant pituitary. These findings suggest that PS1 indirectly mediates the development and/or maintenance of the anterior and intermediate lobes in the pituitary gland via actions in other regions, such as the posterior lobe. PMID:19665542

200 kHz Commercial Sonar Systems Generate Lower Frequency Side Lobes Audible to Some Marine Mammals

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

Deng, Zhiqun; Southall, Brandon; Carlson, Thomas J.

2014-04-15

The spectral properties of pulses transmitted by three commercially available 200 kHz echo sounders were measured to assess the possibility that sound energy in below the center (carrier) frequency might be heard by marine mammals. The study found that all three sounders generated sound at frequencies below the center frequency and within the hearing range of some marine mammals and that this sound was likely detectable by the animals over limited ranges. However, at standard operating source levels for the sounders, the sound below the center frequency was well below potentially harmful levels. It was concluded that the sounds generatedmore » by the sounders could affect the behavior of marine mammals within fairly close proximity to the sources and that that the blanket exclusion of echo sounders from environmental impact analysis based solely on the center frequency output in relation to the range of marine mammal hearing should be reconsidered.« less

[Electormagnetic field of the mobile phone base station: case study].

PubMed

Bieńkowski, Paweł; Zubrzak, Bartłomiej; Surma, Robert

2011-01-01

The paper presents changes in the electromagnetic field intensity in a school building and its surrounding after the mobile phone base station installation on the roof of the school. The comparison of EMF intensity measured before the base station was launched (electromagnetic background measurement) and after starting its operation (two independent control measurements) is discussed. Analyses of measurements are presented and the authors also propose the method of the electromagnetic field distribution adjustment in the area of radiation antennas side lobe to reduce the intensity of the EMF level in the base station proximity. The presented method involves the regulation of the inclination. On the basis of the measurements, it was found that the EMF intensity increased in the building and its surroundings, but the values measured with wide margins meet the requirements of the Polish law on environmental protection.

Nonlinear propagation in ultrasonic fields: measurements, modelling and harmonic imaging.

PubMed

Humphrey, V F

2000-03-01

In high amplitude ultrasonic fields, such as those used in medical ultrasound, nonlinear propagation can result in waveform distortion and the generation of harmonics of the initial frequency. In the nearfield of a transducer this process is complicated by diffraction effects associated with the source. The results of a programme to study the nonlinear propagation in the fields of circular, focused and rectangular transducers are described, and comparisons made with numerical predictions obtained using a finite difference solution to the Khokhlov-Zabolotskaya-Kuznetsov (or KZK) equation. These results are extended to consider nonlinear propagation in tissue-like media and the implications for ultrasonic measurements and ultrasonic heating are discussed. The narrower beamwidths and reduced side-lobe levels of the harmonic beams are illustrated and the use of harmonics to form diagnostic images with improved resolution is described.

Direction selective structural-acoustic coupled radiator

NASA Astrophysics Data System (ADS)

Seo, Hee-Seon; Kim, Yang-Hann

2005-04-01

This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

Macroscopic anatomy of the reproductive tract of the reproductively quiescent female emu (Dromaius novaehollandiae).

PubMed

Reed, Robert B; Cope, Lee A; Blackford, James T

2011-04-01

Three reproductively quiescent female emus (Dromaius novaehollandiae) were embalmed with 10% formalin solution. The reproductive tract was dissected and described. The reproductive tract consists of an ovary and oviduct situated on the left side of the abdominal cavity. The left ovary is dark brown to black in colour with follicles covering the ventral surface. The ovary is located medial to the spleen and closely associated with the ventral surface of the cranial and middle lobes of the left kidney. The oviduct is a relatively straight tube that extends from the level of the cranial extent of the left ilium to the caudal border of the left pubic bone. The oviduct is grossly divided into the infundibulum, magnum, isthmus, uterus and vagina using variations in the mucosal fold pattern. © 2010 Blackwell Verlag GmbH.

Inhalation of the propeller from a spinhaler.

PubMed

Polosa, R; Finnerty, J P

1991-02-01

A 39 yr old man with a 5 yr history of asthma opened his spinhaler to inspect it. He sucked at the capsule to see if its contents were damp. The capsule and propeller came off the spindle, and he aspirated them. He attended a casualty department. The chest radiogram was normal. Over the next three months he developed dypnoea and pain in his chest. He also noticed a whistling noise from his chest, more marked when he lay on his right side. On renewed examination, expiration was prolonged over the right side of the chest, and an occasional whistling wheeze could be heard on that side. A renewed chest radiogram was normal. By means of rigid bronchoscopy, the spindle was removed from its lodged position in the right intermediary bronchus just beyond the orifice to the right upper lobe.

Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction.

PubMed

Bejot, Yannick; Caillier, Marie; Osseby, Guy-Victor; Didi, Roy; Ben Salem, Douraied; Moreau, Thibault; Giroud, Maurice

2008-02-01

Ischemia of the areas supplied by the anterior cerebral artery is relatively uncommon. In addition, combined hemiballismus and masturbation have rarely been reported in patients with cerebrovascular disease. We describe herein a 62-year-old right-handed man simultaneously exhibiting right side hemiballismus and involuntary masturbation with the left hand after bilateral infarction of the anterior cerebral artery territory. Right side hemiballismus was related to the disruption of afferent fibers from the left frontal lobe to the left subthalamic nucleus. Involuntary masturbation using the left hand was exclusively linked to a callosal type of alien hand syndrome secondary to infarction of the right side of the anterior corpus callosum. After 2 weeks, these abnormal behaviours were completely extinguished. This report stresses the wide diversity of clinical manifestations observed after infarction of the anterior cerebral artery territory.

Thyroid lobe ablation with iodine- ¹³¹I in patients with differentiated thyroid carcinoma: a randomized comparison between 1.1 and 3.7 GBq activities.

PubMed

Giovanella, Luca; Piccardo, Arnoldo; Paone, Gaetano; Foppiani, Luca; Treglia, Giorgio; Ceriani, Luca

2013-08-01

The present study was undertaken to evaluate the ablation rate after administration of 1.1 or 3.7 GBq of iodine- (¹³¹I) to patients with low-risk differentiated thyroid carcinoma (DTC) primarily treated by lobectomy. Enrolled were 136 consecutive patients affected by histologically proven low-risk DTC previously treated by lobectomy. Patients were randomized to receive a single dose of 1.1 or 3.7 GBq of ¹³¹I in an equivalence trial. Successful thyroid ablation was defined as a negative diagnostic whole-body scan and stimulated thyroglobulin levels lower than 2 ng/ml in the absence of thyroglobulin antibodies. The patient demographic and clinical data were well balanced at baseline. The ablation rate was significantly (P<0.01) higher in patients treated with 3.7 GBq (75%) than in those treated with 1.1 GBq (54%) of radioiodine. No relevant side effects occurred in either group. Radioiodine lobe ablation with a single administration of 3.7 GBq is a simple and safe mode of treatment, achieving an ablation rate higher than that of 1.1 GBq. This procedure may be offered as an alternative to completion thyroidectomy in highly selected DTC patients who had experienced complications during initial surgery or for whom completion thyroidectomy is contraindicated.

Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

PubMed

Ahmedov, Merdin Lyutviev; Kemerdere, Rahsan; Baran, Oguz; Inal, Berrin Bercik; Gumus, Alper; Coskun, Cihan; Yeni, Seher Naz; Eren, Bulent; Uzan, Mustafa; Tanriverdi, Taner

2017-10-01

We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r 2  = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r 2  = 0.7, P = 0.00001 and r 2  = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r 2  = 0.06, P = 0.00001). Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature. Copyright © 2017 Elsevier Inc. All rights reserved.

Antennas.

DTIC Science & Technology

1982-03-03

drum of a particular diameter [3]. The supply drum was braked in doing this in order to create the necessary stretching force. The rewinding was done...Solar .4 and Lunar disc . Unfortunately, the accuracy of this method is low, and side lobes are practically impossible to measure. Preliminary trueing of...component). This recording of the Sun contains radiation from a group of spots on the right half (of the recording) of the Solar disc . Since the

Pulmonary Lobe Segmentation with Probabilistic Segmentation of the Fissures and a Groupwise Fissure Prior

PubMed Central

Bragman, Felix J.S.; McClelland, Jamie R.; Jacob, Joseph; Hurst, John R.; Hawkes, David J.

2017-01-01

A fully automated, unsupervised lobe segmentation algorithm is presented based on a probabilistic segmentation of the fissures and the simultaneous construction of a population model of the fissures. A two-class probabilistic segmentation segments the lung into candidate fissure voxels and the surrounding parenchyma. This was combined with anatomical information and a groupwise fissure prior to drive non-parametric surface fitting to obtain the final segmentation. The performance of our fissure segmentation was validated on 30 patients from the COPDGene cohort, achieving a high median F1-score of 0.90 and showed general insensitivity to filter parameters. We evaluated our lobe segmentation algorithm on the LOLA11 dataset, which contains 55 cases at varying levels of pathology. We achieved the highest score of 0.884 of the automated algorithms. Our method was further tested quantitatively and qualitatively on 80 patients from the COPDGene study at varying levels of functional impairment. Accurate segmentation of the lobes is shown at various degrees of fissure incompleteness for 96% of all cases. We also show the utility of including a groupwise prior in segmenting the lobes in regions of grossly incomplete fissures. PMID:28436850

Per Operative Study of Relation of Zuckerkandl Tubercle with Recurrent Laryngeal Nerve in Thyroid Surgery.

PubMed

Singh, Priyanka; Sharma, Kalpana; Agarwal, Sunita

2017-09-01

To identify Zuckerkandl tubercle and to determine relationship between the recurrent laryngeal nerve and Zuckerkandl tubercle (ZT). Peroperative study. Intraoperatively Zuckerkandl tubercle was identified. Size of the thyroid lobe and Zuckerkandl tubercle were co-related and direction of tubercle in relation to recurrent laryngeal nerve was examined. Grading of tubercle on the basis of size was done. We studied its direction and relation with recurrent laryngeal nerve. ZT was identified in 87.86% (179 out of 206) of cases. In the study amongst the 179 cases in whom ZT could be identified, ZT was found on the right side (85.41% i.e. 123 out of 144), 81.41% (92 out of 113) to the left side and 15.68% (8 out of 51) were B/L. ZT was found posterior to the tubercle in 97.22%(175 out of 179) cases and anterior to the tubercle in 2.77% (5 out of 179) cases. The relationship between recurrent laryngeal nerve and ITA was studied. ITA was anterior to RLN (in 70.89%) and posterior to RLN in 29.10%. Thus, ZT is an important landmark for identification of RLN during thyroidectomy ( p value 0.001). Level of evidence III.

Buried Crater

NASA Image and Video Library

2002-12-04

With a location roughly equidistant between two of the largest volcanic constructs on the planet, the fate of the approximately 50 km 31 mile impact crater in this image from NASA Mars Odyssey was sealed. It has been buried to the rim by lava flows. The MOLA context image shows pronounced flow lobes surrounding the crater, a clear indication of the most recent episode of volcanism that could have contributed to its infilling. Breaches in the rim are clearly evident in the image and suggest locations through which lavas could have flowed. These openings appear to be limited to the west side of the crater. Other craters in the area are nearly obliterated by the voluminous lava flows, further demonstrating one of the means by which Mars renews its surface. The MOLA context image shows pronounced flow lobes surrounding the crater, a clear indication of the most recent episode of volcanism that could have contributed to its infilling. Breaches in the rim are clearly evident in the image and suggest locations through which lavas could have flowed. These openings appear to be limited to the west side of the crater. Other craters in the area are nearly obliterated by the voluminous lava flows, further demonstrating one of the means by which Mars renews its surface. http://photojournal.jpl.nasa.gov/catalog/PIA04018

Experimental and numerical investigation of tissue harmonic imaging (THI)

NASA Astrophysics Data System (ADS)

Jing, Yuan; Yang, Xinmai; Cleveland, Robin O.

2003-04-01

In THI the probing ultrasonic pulse has enough amplitude that it undergoes nonlinear distortion and energy shifts from the fundamental frequency of the pulse into its higher harmonics. Images generated from the second harmonic (SH) have superior quality to the images formed from the fundamental frequency. Experiments with a single element focused ultrasound transducer were used to compare a line target embedded in a tissue phantom using either fundamental or SH imaging. SH imaging showed an improvement in both the axial resolution (0.70 mm vs 0.92 mm) and the lateral resolution (1.02 mm vs 2.70 mm) of the target. In addition, the contrast-to-tissue ratio of the target was 2 dB higher with SH imaging. A three-dimensional model of the forward propagation has been developed to simulate the experimental system. The model is based on a time-domain code for solving the KZK equation and accounts for arbitrary spatial variations in all tissue properties. The code was used to determine the impact of a nearfield layer of fat on the fundamental and second harmonic signals. For a 15 mm thick layer the SH side-lobes remained the same but the fundamental side-lobes increased by 2 dB. [Work supported by the NSF through the Center for Subsurface Sensing and Imaging Systems.

Autobiographical memory loss following a right prefrontal lobe tumour resection: a case report and review of the literature.

PubMed

Jamjoom, A A B; Gallo, P; Kandasamy, J; Phillips, J; Sokol, D

2017-07-01

The right prefrontal lobe has not traditionally been considered eloquent brain. Resection of tumours within this region does not typically lead to permanent functional impairment. In this report, we highlight the case of a patient who developed autobiographical memory loss following an uncomplicated resection of a right prefrontal tumour. A previously fit and well 15-year old presented with a persistent right-sided headache. An MRI demonstrated an expanded right mid-frontal gyrus with changes consistent with a low-grade tumour. The patient underwent a right-sided craniotomy and resection of the lesion which was confirmed as a WHO grade II diffuse astrocytoma. Postoperatively, the patient reported profound retrograde amnesia for a range of memory components, in particular autobiographical memory and semantic memory. Postoperative imaging showed a good resection margin with no evidence of underlying brain injury. Over an 18-month period, the patient showed no improvement in autobiographical memory; however, significant relearning of semantic knowledge took place and her academic performance was found to be in line with expectations for her age. In this report, we discuss a case and review the literature on the role of the right prefrontal cortex in memory and caution on the perception of right prefrontal non-eloquence.

Imaging of odor perception delineates functional disintegration of the limbic circuits in mesial temporal lobe epilepsy.

PubMed

Ciumas, Carolina; Lindström, Per; Aoun, Bernard; Savic, Ivanka

2008-01-15

Metabolic and neuro-receptor abnormalities within the extrafocal limbic circuits are established in mesial temporal lobe epilepsy (MTLE). However, very little is known about how these circuits process external stimuli. We tested whether odor activation can help delineate limbic functional disintegration in MTLE, and measured cerebral blood flow with PET during birhinal smelling of familiar and unfamiliar odors, using smelling of odorless air as the baseline condition. Patients with MTLE (13 left-sided, 10 right-sided) and 21 controls were investigated. In addition to odor activation, the analysis included functional connectivity, using right and left piriform cortex as seed regions. Healthy controls activated the amygdala, piriform, anterior insular, and cingulate cortices on both sides. Smelling of familiar odors engaged, in addition, the right parahippocampus, and the left Brodmann Area (BA) 44, 45, 47. Patients failed to activate the amygdala, piriform and the anterior insular cortex in the epileptogenic hemisphere. Furthermore, those with left MTLE did not activate the left BA 44, 45 and 47 with familiar odors, which they perceived as less familiar than controls. Congruent with the activation data each seed region was in patients functionally disconnected with the contralateral amygdala+piriform+insular cortex. The functional disintegration in patients exceeded the reduced activation, and included the contralateral temporal neocortex, and in subjects with right MTLE also the right orbitofrontal cortex. Imaging of odor perception may be used to delineate functional disintegration of the limbic networks in MTLE. It shows an altered response in several regions, which may underlie some interictal behavioral problems associated with this condition.

Incomplete Hippocampal Inversion: A Comprehensive MRI Study of Over 2000 Subjects.

PubMed

Cury, Claire; Toro, Roberto; Cohen, Fanny; Fischer, Clara; Mhaya, Amel; Samper-González, Jorge; Hasboun, Dominique; Mangin, Jean-François; Banaschewski, Tobias; Bokde, Arun L W; Bromberg, Uli; Buechel, Christian; Cattrell, Anna; Conrod, Patricia; Flor, Herta; Gallinat, Juergen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Ittermann, Bernd; Lemaitre, Hervé; Martinot, Jean-Luc; Nees, Frauke; Paillère Martinot, Marie-Laure; Orfanos, Dimitri P; Paus, Tomas; Poustka, Luise; Smolka, Michael N; Walter, Henrik; Whelan, Robert; Frouin, Vincent; Schumann, Gunter; Glaunès, Joan A; Colliot, Olivier

2015-01-01

The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ(2)-test, p < 10(-28)). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe.

Incomplete Hippocampal Inversion: A Comprehensive MRI Study of Over 2000 Subjects

PubMed Central

Cury, Claire; Toro, Roberto; Cohen, Fanny; Fischer, Clara; Mhaya, Amel; Samper-González, Jorge; Hasboun, Dominique; Mangin, Jean-François; Banaschewski, Tobias; Bokde, Arun L. W.; Bromberg, Uli; Buechel, Christian; Cattrell, Anna; Conrod, Patricia; Flor, Herta; Gallinat, Juergen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Ittermann, Bernd; Lemaitre, Hervé; Martinot, Jean-Luc; Nees, Frauke; Paillère Martinot, Marie-Laure; Orfanos, Dimitri P.; Paus, Tomas; Poustka, Luise; Smolka, Michael N.; Walter, Henrik; Whelan, Robert; Frouin, Vincent; Schumann, Gunter; Glaunès, Joan A.; Colliot, Olivier

2015-01-01

The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ2−test, p < 10−28). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe. PMID:26733822

Preparing an autonomous, low-cost GNSS positioning and timing function on board a GEO telecom mission: a study case

NASA Astrophysics Data System (ADS)

Zin, A.; Scotti, M.; Mangolini, E.; Cappelluti, I.; Fiordiponti, R.; Amalric, J.; Flament, P.; Brouillard, E.; Kowaltschek, S.

2015-06-01

The purpose of this paper is to present a viable solution for a low-cost, autonomous GNSS positioning and timing function integrated in the avionics of a GEO telecomm satellite. This paper is based on a study currently carried out by Thales Alenia Space under an ARTES contract with ESA, funded by the Italian Space Agency. The availability of an autonomous means of positioning in GEO platform is essential in reducing the constraints on the ground control. This is even more true in the case of the transfer to the GEO orbit, where the current trend is to implement the low-thrust electrical propulsion and this phase could have a duration of months: the GNSS function can autonomously feed the on-board trajectory propagator with the spacecraft position fixes, in order to constrain the state estimate of the on-board filter. In order to achieve large availability of position and timing of the hosting platform, the tracking of the GNSS antenna side lobes is a critical feature. Based on the recent experiences of SGR GEO, additional insights on the side-lobe levels were made available to the GNSS community and this allows to better target a receiver architecture whose performance can be more precisely determined for the study case. This paper will show the findings in terms of GNSS function architecture for the GEO application, as well as the integration of this function inside the avionic computer. The focus is on a single frequency receiver, targeting at least GPS L1 and Galileo E1 signals. Optimizations in terms of sharing of HW resources with the on-board computer (oscillator, DC/DC converter) and the overall redundancy strategy are presented. Extension and implications for covering to the GTO case is presented as well. The expected receiver performances (position and timing accuracy, autonomy) are provided through in-orbit simulations, including a realistic receiver model.

Frontal lobe regulation of blood glucose levels: support for the limited capacity model in hostile violence-prone men.

PubMed

Walters, Robert P; Harrison, Patti Kelly; Campbell, Ransom W; Harrison, David W

2016-12-01

Hostile men have reliably displayed an exaggerated sympathetic stress response across multiple experimental settings, with cardiovascular reactivity for blood pressure and heart rate concurrent with lateralized right frontal lobe stress (Trajanoski et al., in Diabetes Care 19(12):1412-1415, 1996; see Heilman et al., in J Neurol Neurosurg Psychiatry 38(1):69-72, 1975). The current experiment examined frontal lobe regulatory control of glucose in high and low hostile men with concurrent left frontal lobe (Control Oral Word Association Test [verbal]) or right frontal lobe (Ruff Figural Fluency Test [nonverbal]) stress. A significant interaction was found for Group × Condition, F (1,22) = 4.16, p ≤ .05 with glucose levels (mg/dl) of high hostile men significantly elevated as a function of the right frontal stressor (M = 101.37, SD = 13.75) when compared to the verbal stressor (M = 95.79, SD = 11.20). Glucose levels in the low hostile group remained stable for both types of stress. High hostile men made significantly more errors on the right frontal but not the left frontal stressor (M = 17.18, SD = 19.88) when compared to the low hostile men (M = 5.81, SD = 4.33). These findings support our existing frontal capacity model of hostility (Iribarren et al., in J Am Med Assoc 17(19):2546-2551, 2000; McCrimmon et al., in Physiol Behav 67(1):35-39, 1999; Brunner et al., in Diabetes Care 21(4):585-590, 1998), extending the role of the right frontal lobe to regulatory control over glucose mobilization.

[Prediction of occult carcinoma in contralateral nodules based on the ultrasonic features of unilateral papillary thyroid carcinoma].

PubMed

Yang, L M; Li, Q; Zhao, B W; Lyu, J G; Xu, H S; Xu, L L; Li, S Y; Gao, L; Zhu, J

2017-04-07

Objective: To investigate the occurrence of occult carcinoma in contralateral lobes based on the ultrasonic features of unilateral papillary thyroid carcinoma. Methods: The study included 202 consecutives cases of unilateral papillary thyroid carcinoma with benign nodules in the contralateral lobe identified by preoperative ultrasound or fine-needle aspiration from June 2014 to December 2015. All patients received total thyroidectomies, and with postoperative pathological examination they were divided into two groups, one including 60 cases with positive occult cancer and another one consisting of 142 cases with negative occult cancer. Univariate and multivariate analyses were performed to analyze the sonographic features of unilateral papillary thyroid carcinoma relevant to the occurrence of occult carcinoma in the contralateral nodules. Results: Univariate analysis indicated occult carcinoma in the contralateral lobes was associated with Hashimoto's thyroiditis(χ(2)=3.955, P =0.047), unclear border (χ(2)=4.375, P =0.036)and multifocality in the ipsilateral(χ(2)=7.375, P =0.007), but not with tumors maximum size, location, A/T, shape, internal structure, internal echo, acoustic halo, calcification, capsular invasion and blood flow signal in the lobe with carcinoma on another side. Multivariate analysis showed unclear border ( OR =2.727, P =0.010) and multifocality in the ipsilateral( OR =2.807, P =0.005)of carcinoma were independent predictive factor for contralateral occult PTC. Conclusions: Unclear border and multifocality of PTC in the ipsilateral were closely relevant to the occurrence of occult carcinoma in the contralateral nodules.

Differential growth of pavement cells of Arabidopsis thaliana leaf epidermis as revealed by microbead labeling.

PubMed

Elsner, Joanna; Lipowczan, Marcin; Kwiatkowska, Dorota

2018-02-01

In numerous vascular plants, pavement cells of the leaf epidermis are shaped like a jigsaw-puzzle piece. Knowledge about the subcellular pattern of growth that accompanies morphogenesis of such a complex shape is crucial for studies of the role of the cytoskeleton, cell wall and phytohormones in plant cell development. Because the detailed growth pattern of the anticlinal and periclinal cell walls remains unknown, our aim was to measure pavement cell growth at a subcellular resolution. Using fluorescent microbeads applied to the surface of the adaxial leaf epidermis of Arabidopsis thaliana as landmarks for growth computation, we directly assessed the growth rates for the outer periclinal and anticlinal cell walls at a subcellular scale. We observed complementary tendencies in the growth pattern of the outer periclinal and anticlinal cell walls. Central portions of periclinal walls were characterized by relatively slow growth, while growth of the other wall portions was heterogeneous. Local growth of the periclinal walls accompanying lobe development after initiation was relatively fast and anisotropic, with maximal extension usually in the direction along the lobe axis. This growth pattern of the periclinal walls was complemented by the extension of the anticlinal walls, which was faster on the lobe sides than at the tips. Growth of the anticlinal and outer periclinal walls of leaf pavement cells is heterogeneous. The growth of the lobes resembles cell elongation via diffuse growth rather than tip growth. © 2018 Botanical Society of America.

The Analysis of the Strength, Distribution and Direction for the EEG Phase Synchronization by Musical Stimulus

NASA Astrophysics Data System (ADS)

Ogawa, Yutaro; Ikeda, Akira; Kotani, Kiyoshi; Jimbo, Yasuhiko

In this study, we propose the EEG phase synchronization analysis including not only the average strength of the synchronization but also the distribution and directions under the conditions that evoked emotion by musical stimuli. The experiment is performed with the two different musical stimuli that evoke happiness or sadness for 150 seconds. It is found that the average strength of synchronization indicates no difference between the right side and the left side of the frontal lobe during the happy stimulus, the distribution and directions indicate significant differences. Therefore, proposed analysis is useful for detecting emotional condition because it provides information that cannot be obtained only by the average strength of synchronization.

Elevated mitochondrial gene expression during rat liver regeneration after portal vein ligation.

PubMed

Shimizu, Y; Suzuki, H; Nimura, Y; Onoue, S; Nagino, M; Tanaka, M; Ozawa, T

1995-10-01

We explored the molecular basis of mitochondrial energy production during rat liver regeneration after portal vein ligation. Ligation of the left branch of the portal vein induces an increase in the weight of the nonligated lobe, counterbalancing the reduced weight of the ligated lobe. Using this model, we investigated changes in mitochondrial DNA-binding proteins, mitochondrial DNA, and mitochondrial messenger RNA (mRNA) in rat hepatocytes of the nonligated lobes. The amount of mitochondrial DNA-binding protein increased maximally (200% to 300% of the preoperative level) at 12 hours after the operation, before an increase (390%) in mitochondrial DNA content at 24 hours, and parallel to an increase (240%) in mitochondrial mRNA levels at 12 hours. These results suggest that the energy supply for liver regeneration is achieved through enhancement of mitochondrial DNA replication as well as transcription, in which the mitochondrial DNA-binding proteins probably play regulatory roles. We also found that in the nonligated lobes, mRNA levels of hepatocyte growth factor increased to a detectable level only 12 hours after the operation. These molecular biochemical data help explain why preoperative portal vein embolization, which is a modification of portal vein branch ligation, is an effective method to prevent posthepatectomy liver failure.

Nonthermal ablation of deep brain targets: A simulation study on a large animal model

PubMed Central

Top, Can Barış; White, P. Jason; McDannold, Nathan J.

2016-01-01

Purpose: Thermal ablation with transcranial MRI-guided focused ultrasound (FUS) is currently limited to central brain targets because of heating and other beam effects caused by the presence of the skull. Recently, it was shown that it is possible to ablate tissues without depositing thermal energy by driving intravenously administered microbubbles to inertial cavitation using low-duty-cycle burst sonications. A recent study demonstrated that this ablation method could ablate tissue volumes near the skull base in nonhuman primates without thermally damaging the nearby bone. However, blood–brain disruption was observed in the prefocal region, and in some cases, this region contained small areas of tissue damage. The objective of this study was to analyze the experimental model with simulations and to interpret the cause of these effects. Methods: The authors simulated prior experiments where nonthermal ablation was performed in the brain in anesthetized rhesus macaques using a 220 kHz clinical prototype transcranial MRI-guided FUS system. Low-duty-cycle sonications were applied at deep brain targets with the ultrasound contrast agent Definity. For simulations, a 3D pseudospectral finite difference time domain tool was used. The effects of shear mode conversion, focal steering, skull aberrations, nonlinear propagation, and the presence of skull base on the pressure field were investigated using acoustic and elastic wave propagation models. Results: The simulation results were in agreement with the experimental findings in the prefocal region. In the postfocal region, however, side lobes were predicted by the simulations, but no effects were evident in the experiments. The main beam was not affected by the different simulated scenarios except for a shift of about 1 mm in peak position due to skull aberrations. However, the authors observed differences in the volume, amplitude, and distribution of the side lobes. In the experiments, a single element passive cavitation detector was used to measure the inertial cavitation threshold and to determine the pressure amplitude to use for ablation. Simulations of the detector’s acoustic field suggest that its maximum sensitivity was in the lower part of the main beam, which may have led to excessive exposure levels in the experiments that may have contributed to damage in the prefocal area. Conclusions: Overall, these results suggest that case-specific full wave simulations before the procedure can be useful to predict the focal and the prefocal side lobes and the extent of the resulting bioeffects produced by nonthermal ablation. Such simulations can also be used to optimally position passive cavitation detectors. The disagreement between the simulations and the experiments in the postfocal region may have been due to shielding of the ultrasound field due to microbubble activity in the focal region. Future efforts should include the effects of microbubble activity and vascularization on the pressure field. PMID:26843248

Structural MRI research in patients with nasopharyngeal carcinoma following radiotherapy: A DTI and VBM study.

PubMed

Leng, Xi; Fang, Peng; Lin, Huan; An, Jie; Tan, Xin; Zhang, Chi; Wu, Donglin; Shen, Wen; Qiu, Shijun

2017-11-01

The aim of the present study was to investigate the microstructural characteristics of the brain lobes following radiotherapy (RT) for patients with nasopharyngeal carcinoma (NPC) at distinct times. Diffusion tensor imaging (DTI) and 3D-T1-weighted imaging was performed in 70 age- and sex-matched subjects, 24 of whom were pre-treatment patients. The patients were divided into three groups, according to the time following completion of RT. Fractional anisotropy (FA) and gray matter (GM) volume were determined. The DTI data were analyzed using tract-based spatial statistics and the GM volume was analyzed using voxel-based morphometry (VBM). Compared with the pre-RT group, the mean FA values in the left parietal lobe white matter (WM) and right cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05). In addition, the mean FA values in the right parietal lobe WM decreased significantly in the post-RT 6-12 month group (P<0.05), compared with the pre-RT group. The FA level in the right temporal lobe remained significantly decreased, compared with that in the pre-RT group (P<0.05) for 1 year after RT. Furthermore, compared with pre-RT group, the GM volume in the bilateral frontal lobe, right occipital lobe, left parietal lobe, right temporal lobe and left cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05), and in the bilateral temporal lobe, parietal lobe, right frontal lobe and left cerebellum, the GM volume decreased significantly in the post-RT 6-12 month group (P<0.05). The GM volume in the right temporal lobe, bilateral frontal lobe and bilateral cerebellum remained significantly decreased compared with that in the pre-RT group (P<0.05) for 1 year after RT. A combination of DTI and VBM may be used to determine radiation-induced brain injury in patients treated for NPC.

Video-assisted thoracoscopic surgery (VATS) right upper lobectomy for non-small-cell lung cancer with an azygos lobe

PubMed Central

Samancilar, Ozgur; Kaya, Seyda Ors; Sevinc, Serpil; Akcay, Onur; Ceylan, Kenan Can

2016-01-01

Although it is not a pathologically significant entity, cases of azygos lobe (AL) are interesting due to the difficulty of performing video-assisted thoracoscopic surgery (VATS) procedures in the affected patients and the presence of a congenital malformation. Currently, videothoracoscopic surgery has advanced to such a level that most thoracic procedures can be performed with video assistance. However, some technical difficulties may arise in cases with anatomical anomalies such as AL. This report presents the case of a patient with an azygos lobe who underwent videothoracoscopic lung resection due to the presence of non-small-cell lung carcinoma in the upper lobe of the right lung. PMID:28096840

The effect of glycosylation on the transferrin structure: A molecular dynamic simulation analysis.

PubMed

Ghanbari, Z; Housaindokht, M R; Bozorgmehr, M R; Izadyar, M

2016-09-07

Transferrins have been defined by the highly cooperative binding of iron and a carbonate anion to form a Fe-CO3-Tf ternary complex. As such, the layout of the binding site residues affects transferrin function significantly; In contrast to N-lobe, C-lobe binding site of the transferrin structure has been less characterized and little research which surveyed the interaction of carbonate with transferrin in the C-lobe binding site has been found. In the present work, molecular dynamic simulation was employed to gain access into the molecular level understanding of carbonate binding site and their interactions in each lobe. Residues responsible for carbonate binding of transferrin structure were pointed out. In addition, native human transferrin is a glycoprotein that two N-linked complex glycan chains located in the C-lobe. Usually, in the molecular dynamic simulation for simplifying, glycan is removed from the protein structure. Here, we explore the effect of glycosylation on the transferrin structure. Glycosylation appears to have an effect on the layout of the binding site residue and transferrin structure. On the other hand, sometimes the entire transferrin formed by separated lobes that it allows the results to be interpreted in a straightforward manner rather than more parameters required for full length protein. But, it should be noted that there are differences between the separated lobe and full length transferrin, hence, a comparative analysis by the molecular dynamic simulation was performed to investigate such structural variations. Results revealed that separation in C-lobe caused a significant structural variation in comparison to N-lobe. Consequently, the separated lobes and the full length one are different, showing the importance of the interlobe communication and the impact of the lobes on each other in the transferrin structure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neurotrophins and their receptors in the rat pituitary gland: regulation of BDNF and trkB mRNA levels by adrenal hormones.

PubMed

Kononen, J; Soinila, S; Persson, H; Honkaniemi, J; Hökfelt, T; Pelto-Huikko, M

1994-12-01

We studied the expression of messenger ribonucleic acids (mRNAs) for neurotrophins and neurotrophin receptors in the rat pituitary gland and examined the influence of adrenal hormones on their mRNA levels, using in situ hybridization and Northern blot analysis. The only neurotrophin present at detectable levels in the pituitary was brain-derived neurotrophic factor (BDNF), which was observed in the anterior and intermediate lobes. Several transcripts of the putative receptor for BDNF, trkB, were present in the anterior and posterior lobes of the pituitary. A low amount of trkC mRNA was found in both the anterior and the intermediate lobe. Dexamethasone treatment decreased both BDNF and trkB mRNA levels in the anterior lobe of the pituitary. Adrenalectomy had no effect on trkB expression, but it decreased BDNF mRNA levels in comparison to the control animals. This effect could not be reversed by dexamethasone substitution, suggesting that BDNF, mRNA levels may be regulated not only by glucocorticoids but also by other adrenal hormones. These results demonstrate that BDNF, trkB and trkC are expressed in the pituitary gland and that glucocorticoids and possibly other adrenal hormones may modulate pituitary functions by regulating the expression of neurotrophic factors and their receptors. Whether BDNF acts as a secreted hormone, a trophic factor, or has autocrine/paracrine functions within the pituitary through its receptor, trkB, remains to be studied.

Frontal lobe function in temporal lobe epilepsy

PubMed Central

Stretton, J.; Thompson, P.J.

2012-01-01

Summary Temporal lobe epilepsy (TLE) is typically associated with long-term memory dysfunction. The frontal lobes support high-level cognition comprising executive skills and working memory that is vital for daily life functioning. Deficits in these functions have been increasingly reported in TLE. Evidence from both the neuropsychological and neuroimaging literature suggests both executive function and working memory are compromised in the presence of TLE. In relation to executive impairment, particular focus has been paid to set shifting as measured by the Wisconsin Card Sorting Task. Other discrete executive functions such as decision-making and theory of mind also appear vulnerable but have received little attention. With regard to working memory, the medial temporal lobe structures appear have a more critical role, but with emerging evidence of hippocampal dependent and independent processes. The relative role of underlying pathology and seizure spread is likely to have considerable bearing upon the cognitive phenotype and trajectory in TLE. The identification of the nature of frontal lobe dysfunction in TLE thus has important clinical implications for prognosis and surgical management. Longitudinal neuropsychological and neuroimaging studies assessing frontal lobe function in TLE patients pre- and postoperatively will improve our understanding further. PMID:22100147

Lactoferrin binding protein B – a bi-functional bacterial receptor protein

PubMed Central

Ostan, Nicholas K. H.; Yu, Rong-Hua; Ng, Dixon; Lai, Christine Chieh-Lin; Sarpe, Vladimir; Schriemer, David C.

2017-01-01

Lactoferrin binding protein B (LbpB) is a bi-lobed outer membrane-bound lipoprotein that comprises part of the lactoferrin (Lf) receptor complex in Neisseria meningitidis and other Gram-negative pathogens. Recent studies have demonstrated that LbpB plays a role in protecting the bacteria from cationic antimicrobial peptides due to large regions rich in anionic residues in the C-terminal lobe. Relative to its homolog, transferrin-binding protein B (TbpB), there currently is little evidence for its role in iron acquisition and relatively little structural and biophysical information on its interaction with Lf. In this study, a combination of crosslinking and deuterium exchange coupled to mass spectrometry, information-driven computational docking, bio-layer interferometry, and site-directed mutagenesis was used to probe LbpB:hLf complexes. The formation of a 1:1 complex of iron-loaded Lf and LbpB involves an interaction between the Lf C-lobe and LbpB N-lobe, comparable to TbpB, consistent with a potential role in iron acquisition. The Lf N-lobe is also capable of binding to negatively charged regions of the LbpB C-lobe and possibly other sites such that a variety of higher order complexes are formed. Our results are consistent with LbpB serving dual roles focused primarily on iron acquisition when exposed to limited levels of iron-loaded Lf on the mucosal surface and effectively binding apo Lf when exposed to high levels at sites of inflammation. PMID:28257520

Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

PubMed

Langen, Carolyn D; White, Tonya; Ikram, M Arfan; Vernooij, Meike W; Niessen, Wiro J

2015-01-01

Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1) middle-aged versus elderly subjects; and (2) patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only fractional anisotropy and mean correlation showed regional differences. The presented visualizations were helpful in comparing and evaluating connectivity measures on multiple levels in both studies.

Radio and X-ray structure of Centaurus A

NASA Technical Reports Server (NTRS)

Feigelson, E. D.

1982-01-01

Recent studies of the nearby radio galaxy Centaurus A with the Very Large Array and the Einstein X-Ray Observatory reveal complex radio and X-ray structures. A prominent one-sided jet comprised of resolved knots located 0.2-6 kpc from the nucleus is seen in both radio and X-rays. The X-ray emission is probably synchrotron, requiring in situ reacceleration up to about ten million. Inverse Compton emission is not a likely explanation though a thermal model in which the nucleus ejects dense 100,000 solar mass clouds cannot be excluded. An elongated X-ray region is also found near the 'middle' radio lobe and optical HII regions about 30 kpc NE of the nucleus. Conditions around the active nucleus, the absence of X-rays from the inner radio lobes, and X-ray evidence for a hot interstellar medium are briefly discussed

Massive cortico-subcortical ischemic stroke with a consecutive hemorrhagic event: a case report.

PubMed

Pirici, D; Ion, Daniela Adriana; Mogoantă, L; Mărgăritescu, Otilia; Pirici, Ionica; Foarfă, Camelia; Tudorică, Valerica; Panduru, N M; Coconu, Marieta; Checheriţă, I A

2011-01-01

We report a case of a 78-year-old woman with a large cerebral infarction probably due to athermanous embolism following atrial fibrillation. The patient, known with atrial fibrillation, high blood pressure and heart failure, complained of headache and motor impairment on the left side of the body. CT imaging revealed a subacute ischemic lesion in the right fronto-occipital lobes, and an old ischemic lesion in the right fronto-parietal lobes. Anticoagulant treatment was conducted with careful monitoring of the coagulability status. After almost three weeks, suddenly the patient became comatose and died shortly after. Macroscopic and microscopic examination confirmed the cortico-subcortical ischemic lesions, but also identified a fresh hemorrhagic site in pons, distant from the initial lesion sites. An immunohistochemical study identified blood vessels in the ischemic sites completely isolated from any glial support. This is a rare case of a large cerebral infarction with a pontine hemorrhagic event.

Bilateral Arterial Embolization of the Prostate Through a Single Prostatic Artery: A Case Series

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

Amouyal, Gregory, E-mail: gregamouyal@hotmail.com; Pellerin, Olivier, E-mail: olivier.pellerin@aphp.fr; Giudice, Costantino Del, E-mail: costantino.delgiudice@aphp.fr

Peri-prostatic shunts are frequent during PAE, carrying the risk of non-target embolization of penis/corpus cavernosum or rectum but also the potential advantage to irrigate the contralateral lobe. Sometimes, bilateral embolization is impossible, carrying the risk of limited clinical success. The possibility to reach contralateral prostatic territory from the ipsilateral prostatic artery (PA) and embolize it via peri/intra-prostatic anastomoses could be of interest in this situation. We describe a series of three consecutive patients (among 89 consecutive patients treated by PAE for symptomatic BPH) who underwent successful embolization of both prostatic lobes through catheterization of a PA on only one side.more » All patients had clinical success after a mean follow-up of 3.3 months. Dosimetry of these three procedures indicates that there may be radiation dose savings.« less

Evolutionary Beamforming Optimization for Radio Frequency Charging in Wireless Rechargeable Sensor Networks.

PubMed

Yao, Ke-Han; Jiang, Jehn-Ruey; Tsai, Chung-Hsien; Wu, Zong-Syun

2017-08-20

This paper investigates how to efficiently charge sensor nodes in a wireless rechargeable sensor network (WRSN) with radio frequency (RF) chargers to make the network sustainable. An RF charger is assumed to be equipped with a uniform circular array (UCA) of 12 antennas with the radius λ , where λ is the RF wavelength. The UCA can steer most RF energy in a target direction to charge a specific WRSN node by the beamforming technology. Two evolutionary algorithms (EAs) using the evolution strategy (ES), namely the Evolutionary Beamforming Optimization (EBO) algorithm and the Evolutionary Beamforming Optimization Reseeding (EBO-R) algorithm, are proposed to nearly optimize the power ratio of the UCA beamforming peak side lobe (PSL) and the main lobe (ML) aimed at the given target direction. The proposed algorithms are simulated for performance evaluation and are compared with a related algorithm, called Particle Swarm Optimization Gravitational Search Algorithm-Explore (PSOGSA-Explore), to show their superiority.

Choice of antenna geometry for microwave power transmission from solar power satellites

NASA Technical Reports Server (NTRS)

Potter, Seth D.

1992-01-01

A comparison is made between square and circular transmitting antennas for solar power satellite microwave power transmission. It is seen that the exclusion zone around the rectenna needed to protect populations from microwaves is smaller for a circular antenna operating at 2.45 GHz than it is for a square antenna at that frequency. If the frequency is increased, the exclusion zone size remains the same for a square antenna, but becomes even smaller for a circular antenna. Peak beam intensity is the same for both antennas if the frequency and antenna area are equal. The circular antenna puts a somewhat greater amount of power in the main lobe and somewhat less in the side lobes. Since rain attenuation and atmospheric heating remain problems above 10 GHz, it is recommended that future solar power satellite work concentrate on circular transmitting antennas at frequencies of roughly 10 GHz.

CMG–Pol epsilon dynamics suggests a mechanism for the establishment of leading-strand synthesis in the eukaryotic replisome

PubMed Central

Janska, Agnieszka; Goswami, Panchali; Renault, Ludovic; Abid Ali, Ferdos; Kotecha, Abhay; Costa, Alessandro

2017-01-01

The replisome unwinds and synthesizes DNA for genome duplication. In eukaryotes, the Cdc45–MCM–GINS (CMG) helicase and the leading-strand polymerase, Pol epsilon, form a stable assembly. The mechanism for coupling DNA unwinding with synthesis is starting to be elucidated, however the architecture and dynamics of the replication fork remain only partially understood, preventing a molecular understanding of chromosome replication. To address this issue, we conducted a systematic single-particle EM study on multiple permutations of the reconstituted CMG–Pol epsilon assembly. Pol epsilon contains two flexibly tethered lobes. The noncatalytic lobe is anchored to the motor of the helicase, whereas the polymerization domain extends toward the side of the helicase. We observe two alternate configurations of the DNA synthesis domain in the CMG-bound Pol epsilon. We propose that this conformational switch might control DNA template engagement and release, modulating replisome progression. PMID:28373564

Correlated Oscillations Due to Similar Multipath Effects Seen in Two Widely Separated Radio Telescopes

NASA Astrophysics Data System (ADS)

Diep, P. N.; Phuong, N. T.; Darriulat, P.; Nhung, P. T.; Anh, P. T.; Dong, P. N.; Hoai, D. T.; Thao, N. T.

2014-07-01

A multipath mechanism similar to that used in Australia sixty years ago by the Sea-cliff Interferometer is shown to generate correlations between the periods of oscillations observed by two distant radio telescopes pointed to the Sun. The oscillations are the result of interferences between the direct wave detected in the main antenna lobe and its reflection on ground detected in a side lobe. A model is made of such oscillations in the case of two observatories located at equal longitudes and opposite tropical latitudes, respectively in Ha Noi (Viet Nam) and Learmonth (Australia), where similar radio telescopes are operated at 1.4 GHz. Simple specular reflection from ground is found to give a good description of the observed oscillations and to explain correlations that had been previously observed and for which no satisfactory interpretation, instrumental or other, had been found.

Subependymal Heterotopia Mimicking Mass in Conventional Magnetic Resonance Imaging: Demonstration With 3T Advanced Neuroimages.

PubMed

Aktas, Filiz; Ogul, Hayri

2017-10-01

The authors reported a rare patient with large subependymal heterotopia mimicking cerebral neoplasia. A 22-year-old female was admitted with a history of right-sided paresthesia accompanied by progressive headache. Cerebral magnetic resonance (MR) imaging showed a large solid lesion in the left frontal lobe. Advanced MR images proved that the lesion was compatible with subependymal heterotopia. Large subependymal heterotopia may mimick cerebral neoplasia.

Experimental demonstration of PAM-DWMT for passive optical network

NASA Astrophysics Data System (ADS)

Lin, Bangjiang; Zhang, Kaiwei; Tang, Xuan; Ghassemlooy, Zabih; Lin, Chun; Zhou, Zhenlei

2018-07-01

We experimentally demonstrate a discrete wavelet multitone (DWMT) modulation scheme based on pulse amplitude modulation (PAM) for next generation passive optical network (PON), which offers high tolerance against chromatic dispersion, high spectral efficiency, low peak to average power ratio (PAPR) and low side lobes. The experimental results show the chromatic dispersion induced power penalties are negligible after 20km fiber transmission. Compared with orthogonal frequency division multiplexing (OFDM), DWMT offers a better receiver sensitivity.

Characteristics and Use of a Parametric End-Fired Array for Acoustics in Air

DTIC Science & Technology

2007-03-01

as a sonar application for underwater use. The vast majority of the research for parametric arrays was devoted to underwater applications until the...and also for the calibration of hydrophones and receivers for wide band sonar . All of the researchers mentioned above mainly focused their efforts on...features, which include very high directivity at low frequencies without unwanted side lobes. They are generally used as a wide band sonar system

Microwave Landing System. Phase II. Tracker Error Study.

DTIC Science & Technology

1974-12-01

the runways and environs. The geographical locations of the four phototheodolite towers are indicated on Figure 1-1. A Contraves Model C phototheodolite...temperature 400 K above 500 elevation (dark sky) Side lobe location 1.720 (Ist) Type of scan Monopulse R-f transmission line Rectangular waveguide Line loss ...receiving 1.3 db Line loss transmitting 2.3 db System Facts Azimuth coverage 3600 Elevation coverage -10* to 190* (tracking -10* to 85*) Range accuracy

Four new species of Ligophorus (Monogenea: Dactylogyridae) parasitic on Mugil liza (Actinopterygii: Mugilidae) from Guandu River, southeastern Brazil.

PubMed

Abdallah, Vanessa D; de Azevedo, Rodney K; Luque, José L

2009-08-01

Four species of Ligophorus (Monogenea: Dactylogyridae), i.e., L. tainhae n. sp., L. brasiliensis n. sp., L. guanduensis n. sp., and L. lizae n. sp., are described. The specimens were collected from the gills of Mugil liza (Mugilidae) from the Guandu River (22 degrees 48'32"S, 43 degrees 37'35"W), State of Rio de Janeiro, Brazil, between January 2008 and March 2008. The male copulatory organ of L. tainhae n. sp. differs from the all known species of this genus in having the largest accessory piece, the length of accessory piece exceeding the length of the copulatory organ tube, and the distal tip of the lower lobe crossing the upper lobe. Ligophorus brasiliensis n. sp. and L. guanduensis n. sp. have a similar shape of the accessory piece, but in L. guanduensis n. sp. the lower lobe is larger than the upper lobe (as opposed to L. brasiliensis n. sp.), the ratio between length of upper lobe and the length of the proximal part of the accessory piece before the bifurcation is shorter and the distal tip of the lower lobe extends to the level of the upper lobe (in L. brasiliensis n. sp. the distal tip of lower lobe crossing the upper lobe). In L. lizae n. sp., the terminal bifurcations of the accessory piece are equal in length and unequal in the other 3 new species. Species of Ligophorus are recorded for the first time from Brazil.

Dense Pyroclastic Flows of the 16 -17 August 2006 Eruption of Tungurahua Volcano, Ecuador

NASA Astrophysics Data System (ADS)

Hall, M. L.; Mothes, P. A.; Ramon, P.; Arellano, S.; Barba, D.; Palacios, P.

2007-05-01

The 16-17 August 2006 eruption of Tungurahua volcano in central Ecuador was preceded by 7 years of threatening activity and finally a VEI=2 eruption on 14-15 July 2006. The larger August eruption witnessed tens of pyroclastic flows that descended 17 different channels up to 8.5 km to the volcano's base on the NW, N, W, and SW sides. Tungurahua (5023m) is a steep-sided, low SiO2 andesitic volcano with 2600 to 3200m of relief. The initial, small nuee ardentes began around 1700hr (local time), the larger flows occurred between 2147hr and 0100hr (17 Aug.), and a total of 31 events were indicated by seismic signals. The deposits of three distinct flow cycles are recognized at the NW base of the cone. On the Los Pajaros depositional fan, deposits of flows 1 and 2 are widespread laterally (<600m) and have low-aspect morphologies with low snouts and without levees. Their outer surfaces are covered with accessory > juvenile clasts that mainly range from 15 to 25cm in diameter, conversely their interiors are comprised of 40-42% clasts of 1-25cm size and a matrix (58-60%) of sand-size grains. The earlier flow 1 was accompanied by an ash cloud surge that leveled, but did not scorch, all trees, brush, even metal antenna posts, leaving a 1-10cm thick sandy ash layer upon flow 1's deposit. On the fan as well as in gullies on the upper flanks, flow 3 deposits form long narrow lobes with 1-2m high frontal snouts that are followed by empty flow channels, 5-15m wide, bounded by parallel levees 1-1.5m high. Within these channels subsequent flow lobes are found as remnant pulses. Unlike flows 1 and 2, flow 3 lobes are covered with 0.5-3m cauliflower-shaped, slightly vesiculated bombs that are rarely abraded; the deposit's interior has a 45% sandy matrix. During the climatic eruptive phase continuous lava fountaining, 500-700m high, and crater spilling likely fed a continual stream of fragmented lava onto the cone's upper steep flanks, from which dense pyroclastic mass flows were initiated by gravity. Flows 1 and 2 were more fluidized (due to entrained air and fines), faster, and had wider lateral extents. Flow 3 was poorly fluidized, highly channelized, and behaved more like an inertial granular flow that formed as a continuous avalanche stream that separated into consecutive pulses along the runout channel.

Submarine fans: Characteristics, models, classification, and reservoir potential

NASA Astrophysics Data System (ADS)

Shanmugam, G.; Moiola, R. J.

1988-02-01

Submarine-fan sequences are important hydrocarbon reservoirs throughout the world. Submarine-fan sequences may be interpreted from bed-thickness trends, turbidite facies associations, log motifs, and seismic-reflection profiles. Turbidites occurring predominantly in channels and lobes (or sheet sands) constitute the major portion of submarine-fan sequences. Thinning- and thickening-upward trends are suggestive of channel and lobe deposition, respectively. Mounded seismic reflections are commonly indicative of lower-fan depositional lobes. Fan models are discussed in terms of modern and ancient fans, attached and detached lobes, highly efficient and poorly efficient systems, and transverse and longitudinal fans. In general, depositional lobes are considered to be attached to feeder channels. Submarine fans can be classified into four types based on their tectonic settings: (1) immature passive-margin fans (North Sea type); (2) mature passive-margin fans (Atlantic type); (3) active-margin fans (Pacific type); and (4) mixed-setting fans. Immature passive-margin fans (e.g., Balder, North Sea), and active-margin fans (e.g., Navy, Pacific Ocean) are usually small, sand-rich, and possess well developed lobes. Mature passive-margin fans (e.g., Amazon, Atlantic Ocean) are large, mud-rich, and do not develop typical lobes. However, sheet sands are common in the lower-fan regions of mature passive-margin fans. Mixed-setting fans display characteristics of either Atlantic type (e.g., Bengal, Bay of Bengal), or Pacific type (Orinoco, Caribbean), or both. Conventional channel-lobe models may not be applicable to fans associated with mature passive margins. Submarine fans develop primarily during periods of low sea level on both active- and passive-margin settings. Consequently, hydrocarbon-bearing fan sequences are associated generally with global lowstands of sea level. Channel-fill sandstones in most tectonic settings are potential reservoirs. Lobes exhibit the most favorable reservoir quality in terms of sand content, lateral continuity, and porosity development. Lower-fan sheet sands may also make good reservoirs. Quartz-rich sandstones of mature passive-margin fans are most likely to preserve depositional porosity, whereas lithic sandstones of active-margin fans may not.

Memory Functions following Surgery for Temporal Lobe Epilepsy in Children

ERIC Educational Resources Information Center

Jambaque, Isabelle; Dellatolas, Georges; Fohlen, Martine; Bulteau, Christine; Watier, Laurence; Dorfmuller, Georg; Chiron, Catherine; Delalande, Olivier

2007-01-01

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level,…

MEG Evidence for Incremental Sentence Composition in the Anterior Temporal Lobe

ERIC Educational Resources Information Center

Brennan, Jonathan R.; Pylkkänen, Liina

2017-01-01

Research investigating the brain basis of language comprehension has associated the left anterior temporal lobe (ATL) with sentence-level combinatorics. Using magnetoencephalography (MEG), we test the parsing strategy implemented in this brain region. The number of incremental parse steps from a predictive left-corner parsing strategy that is…

Expression of a repressor form of the Arabidopsis thaliana transcription factor TCP16 induces the formation of ectopic meristems.

PubMed

Uberti-Manassero, Nora G; Coscueta, Ezequiel R; Gonzalez, Daniel H

2016-11-01

Plants that express a fusion of the Arabidopsis thaliana class I TCP transcription factor TCP16 to the EAR repressor domain develop several phenotypic alterations, including rounder leaves, short petioles and pedicels, and delayed elongation of sepals, petals and anthers. In addition, these plants develop lobed cotyledons and ectopic meristems. Ectopic meristems are formed on the adaxial side of cotyledon petioles and arise from a cleft that is formed at this site. Analysis of the expression of reporter genes indicated that meristem genes are reactivated at the site of emergence of ectopic meristems, located near the bifurcation of cotyledon veins. The plants also show increased transcript levels of the boundary-specific CUP-SHAPED COTYLEDON (CUC) genes. The results suggest that TCP16 is able to modulate the induction of meristematic programs and the differentiation state of plant cells. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A case of squamous cell carcinoma of lung presenting with paraneoplastic type of acanthosis nigricans

PubMed Central

Mukherjee, Subhasis; Pandit, Sudipta; Deb, Jaydip; Dattachaudhuri, Arunabha; Bhuniya, Sourin; Bhanja, Pulakesh

2011-01-01

A 70-years-old male presented with blackening of both hands and face for last six months which was progressive and attended dermatology outpatients department. Dermatologist opined the skin lesions as acanthosis nigricans. He was referred to our department to evaluate for any underlying internal malignancy as he was a smoker. His chest X-ray revealed right sided hilar prominence with a mid zone cavity with fluid level. Fibreoptic bronchoscopy was done, there was one ulcerative growth in right middle lobe bronchus. Biopsy from the ulcer revealed probable squamous cell carcinoma. CT scan of thorax was also done and CT guided FNAC of Rt lung lesion yielded non small cell carcinoma. His skin lesions were also biopsied and diagnosis of acanthosis nigricans was confirmed. Here we report a case of acanthosis nigricans associated with non-small cell cancer of lung. PMID:21654990

Linear antenna array optimization using flower pollination algorithm.

PubMed

Saxena, Prerna; Kothari, Ashwin

2016-01-01

Flower pollination algorithm (FPA) is a new nature-inspired evolutionary algorithm used to solve multi-objective optimization problems. The aim of this paper is to introduce FPA to the electromagnetics and antenna community for the optimization of linear antenna arrays. FPA is applied for the first time to linear array so as to obtain optimized antenna positions in order to achieve an array pattern with minimum side lobe level along with placement of deep nulls in desired directions. Various design examples are presented that illustrate the use of FPA for linear antenna array optimization, and subsequently the results are validated by benchmarking along with results obtained using other state-of-the-art, nature-inspired evolutionary algorithms such as particle swarm optimization, ant colony optimization and cat swarm optimization. The results suggest that in most cases, FPA outperforms the other evolutionary algorithms and at times it yields a similar performance.

Biophysical characterization of the calmodulin-like domain of Plasmodium falciparum calcium dependent protein kinase 3

PubMed Central

Andresen, Cecilia; Niklasson, Markus; Cassman Eklöf, Sofie; Wallner, Björn

2017-01-01

Calcium dependent protein kinases are unique to plants and certain parasites and comprise an N-terminal segment and a kinase domain that is regulated by a C-terminal calcium binding domain. Since the proteins are not found in man they are potential drug targets. We have characterized the calcium binding lobes of the regulatory domain of calcium dependent protein kinase 3 from the malaria parasite Plasmodium falciparum. Despite being structurally similar, the two lobes differ in several other regards. While the monomeric N-terminal lobe changes its structure in response to calcium binding and shows global dynamics on the sub-millisecond time-scale both in its apo and calcium bound states, the C-terminal lobe could not be prepared calcium-free and forms dimers in solution. If our results can be generalized to the full-length protein, they suggest that the C-terminal lobe is calcium bound even at basal levels and that activation is caused by the structural reorganization associated with binding of a single calcium ion to the N-terminal lobe. PMID:28746405

Preserving lung after traumatic transection of left lower lobe bronchus from bullet injury.

PubMed

Hanif, Muhammad Shoaib; Mishwani, A H; Oparka, J; Buchan, K

2015-06-01

A 22-year-old soldier was shot in the left chest by a bullet from close range. He was found to have a left haemothorax and remained shocked despite aggressive resuscitation. Due to difficult terrain and night time movement restrictions, there were limitations to the transfer of patient. So he was attended at a peripheral hospital. At emergency thoracotomy, three segmental arteries to left upper lobe were ligated and haemostasis was secured. The level of transection of left lower lobe bronchus was identified to be below the origin of the apical segmental bronchus. The lower lobe bronchus was successfully re-attached and followed up with a daily bronchoscopic clearance of distal airway. The patient made a full recovery. Anastomosis of left lower lobe bronchus after traumatic transection is a viable option for preserving an amputated lobe, in trauma settings, provided haemostatic control has been adequately achieved. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures

PubMed Central

Zepeda, Rodrigo; Cole, Andrew J.; Cash, Sydney S.

2016-01-01

Abstract Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these ‘scalp-negative seizures’ is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer’s disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings. PMID:27474219

Hippocampal Atrophy Is Associated with Altered Hippocampus-Posterior Cingulate Cortex Connectivity in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis.

PubMed

Shih, Y C; Tseng, C E; Lin, F-H; Liou, H H; Tseng, W Y I

2017-03-01

Unilateral mesial temporal lobe epilepsy and hippocampal sclerosis have structural and functional abnormalities in the mesial temporal regions. To gain insight into the pathophysiology of the epileptic network in mesial temporal lobe epilepsy with hippocampal sclerosis, we aimed to clarify the relationships between hippocampal atrophy and the altered connection between the hippocampus and the posterior cingulate cortex in patients with mesial temporal lobe epilepsy with hippocampal sclerosis. Fifteen patients with left mesial temporal lobe epilepsy with hippocampal sclerosis and 15 healthy controls were included in the study. Multicontrast MR imaging, including high-resolution T1WI, diffusion spectrum imaging, and resting-state fMRI, was performed to measure the hippocampal volume, structural connectivity of the inferior cingulum bundle, and intrinsic functional connectivity between the hippocampus and the posterior cingulate cortex, respectively. Compared with controls, patients had decreased left hippocampal volume (volume ratio of the hippocampus and controls, 0.366% ± 0.029%; patients, 0.277% ± 0.063%, corrected P = .002), structural connectivity of the bilateral inferior cingulum bundle (generalized fractional anisotropy, left: controls, 0.234 ± 0.020; patients, 0.193 ± 0.022, corrected P = .0001, right: controls, 0.226 ± 0.022; patients, 0.208 ± 0.017, corrected P = .047), and intrinsic functional connectivity between the left hippocampus and the left posterior cingulate cortex (averaged z-value: controls, 0.314 ± 0.152; patients, 0.166 ± 0.062). The left hippocampal volume correlated with structural connectivity positively (standardized β = 0.864, P = .001), but it had little correlation with intrinsic functional connectivity (standardized β = -0.329, P = .113). On the contralesional side, the hippocampal volume did not show any significant correlation with structural connectivity or intrinsic functional connectivity ( F 2,12 = 0.284, P = .757, R 2 = 0.045). In left mesial temporal lobe epilepsy with hippocampal sclerosis, the left inferior cingulum bundle undergoes degeneration in tandem with the left hippocampal volume, whereas intrinsic functional connectivity seems to react by compensating the loss of connectivity. Such insight might be helpful in understanding the development of the epileptic network in left mesial temporal lobe epilepsy with hippocampal sclerosis. © 2017 by American Journal of Neuroradiology.

Onset of psychosis at age 81? With regard to frontal lobe syndromes

PubMed Central

Pedro, Patrícia; Telles-Correia, Diogo; Godinho, Iolanda; Chagas, Carlos

2015-01-01

When the frontal lobe of the brain is affected important behavioral changes may occur mainly at the level of executive functioning, i.e., planning, decision-making, judgment and self-perception. However, the behavioral changes may be of different nature with marked indifference and apathy. We report a clinical case of an 81-year-old patient with sudden onset of behavioral changes that were initially interpreted as an acute confusional episode of infectious etiology, but actually they were due to an ischemic lesion in the frontal lobe. PMID:26398362

Latest Pleistocene advance and collapse of the Matanuska - Knik glacier system, Anchorage Lowland, southern Alaska

NASA Astrophysics Data System (ADS)

Kopczynski, Sarah E.; Kelley, Samuel E.; Lowell, Thomas V.; Evenson, Edward B.; Applegate, Patrick J.

2017-01-01

At the end of the last ice age, glacier systems worldwide underwent dramatic retreat. Here, we document the advance and retreat of a glacier system with adjacent marine- and land-based components during the latter part of the Termination. We utilize three lines of evidence: lithologic provenance, geomorphic mapping, and radiocarbon ages derived from lake cores to reconstruct glacier extent and timing of advance and retreat within our study area centered at N 61.50°, W 149.50°, just north of Anchorage, Alaska. Two glaciers, sourced in the Talkeetna and Chugach Mountains, flowed down the Matanuska and Knik Valleys forming a coalesced lobe that advanced onto the Anchorage Lowlands and terminated at Elmendorf Moraine. We use the presence of lithologies unique to the Matanuska catchment in glacial drift to delineate the paleoflow lines and to estimate the suture line of the two glacier systems. The eastern side of the lobe, attributed to ice flow from the Knik Valley, was in contact with elevated marine waters within the Knik Arm fjord, and thus retreat was likely dominated by calving. Geomorphic evidence suggests the western side of the lobe, attributed to ice flow from Matanuska Valley, retreated due to stagnation. We constrain retreat of the combined Matanuska and Knik lobe with thirteen new radiocarbon ages, in addition to previously published radiocarbon ages, and with geomorphic evidence suggesting the retreat occurred in two phases. Retreat from the Elmendorf Moraine began between 16.8 and 16.4 ka BP. A second, faster retreat phase occurred later and was completed by 13.7 ka BP. With the 140 km of total retreat occurring over ∼3000 years or less. This pattern of glacial advance and retreats agrees well with the deglacial histories from the southern sectors of the Cordilleran Ice Sheet, as well as many other alpine glacier systems in the western U.S. and northern Alaska. This consistent behavior of glacier systems may indicate that climate oscillated over western North America early in deglaciation before it was recorded in other proxies such as ice cores. Furthermore, the period in which we note mountain glacier collapse in northwestern North America is synchronous with the worldwide glacial termination raising questions about intrahemispheric linkages.

Double-coronal X-Ray and Microwave Sources Associated with a Magnetic Breakout Solar Eruption

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

Chen, Yao; Wu, Zhao; Zhao, Di

Double-coronal hard X-ray (HXR) sources are believed to be critical observational evidence of bi-directional energy release through magnetic reconnection in large-scale current sheets in solar flares. Here, we present a study on double-coronal sources observed in both HXR and microwave regimes, revealing new characteristics distinct from earlier reports. This event is associated with a footpoint-occulted X1.3-class flare (2014 April 25, starting at 00:17 UT) and a coronal mass ejection that were likely triggered by the magnetic breakout process, with the lower source extending upward from the top of the partially occulted flare loops and the upper source co-incident with rapidlymore » squeezing-in side lobes (at a speed of ∼250 km s{sup −1} on both sides). The upper source can be identified at energies as high as 70–100 keV. The X-ray upper source is characterized by flux curves that differ from those of the lower source, a weak energy dependence of projected centroid altitude above 20 keV, a shorter duration, and an HXR photon spectrum slightly harder than those of the lower source. In addition, the microwave emission at 34 GHz also exhibits a similar double-source structure and the microwave spectra at both sources are in line with gyrosynchrotron emission given by non-thermal energetic electrons. These observations, especially the co-incidence of the very-fast squeezing-in motion of side lobes and the upper source, indicate that the upper source is associated with (and possibly caused by) this fast motion of arcades. This sheds new light on the origin of the corona double-source structure observed in both HXRs and microwaves.« less

A rare presentation of aspergillus infection as empyema thoracis

PubMed Central

Goel, Manoj K; Juneja, Deven; Jain, Satinder K; Chaudhuri, Saikiran; Kumar, Ajay

2010-01-01

A 57-year-old diabetic and hypertensive man presented with a short history of fever, dry cough and right side chest pain. A chest radiograph showed right pleural based homogenous shadow in middle and lower zones with obliteration of right costo-phrenic angle suggestive of right side effusion. Aspiration of pleural fluid revealed frank pus for which inter-costal tube drainage was performed. Due to persistence of empyema, the patient was subjected to thoracoscopy. Thoracoscopy showed multiloculated empyema. Thoracoscopic pleural biopsy and fluid showed septate fungal hyphae. Thoracotomy and parietal pleurectomy, with resection of part of right lower lobe, was carried out. Pleural fluid, pleural and lung tissue culture grew Aspergillus fumigatus. The patient showed good recovery with voriconazole after thoracotomy. PMID:20539768

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.

PubMed

Lambon Ralph, Matthew A; Ehsan, Sheeba; Baker, Gus A; Rogers, Timothy T

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy

PubMed Central

Ehsan, Sheeba; Baker, Gus A.; Rogers, Timothy T.

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients’ accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants. PMID:22287382

Lobed Mixer Design for Noise Suppression Acoustic and Aerodynamic Test Data Analysis

NASA Technical Reports Server (NTRS)

Mengle, Vinod G.; Dalton, William N.; Boyd, Kathleen (Technical Monitor); Bridges, James (Technical Monitor)

2002-01-01

A comprehensive database for the acoustic and aerodynamic characteristics of several model-scale lobe mixers of bypass ratio 5 to 6 has been created for mixed jet speeds up to 1080 ft/s at typical take-off (TO) conditions of small-to-medium turbofan engines. The flight effect was simulated for Mach numbers up to 0.3. The static thrust performance and plume data were also obtained at typical TO and cruise conditions. The tests were done at NASA Lewis anechoic dome and ASK's FluiDyne Laboratories. The effect of several lobe mixer and nozzle parameters, such as, lobe scalloping, lobe count, lobe penetration and nozzle length was examined in terms of flyover noise at constant altitude. Sound in the nozzle reference frame was analyzed to understand the source characteristics. Several new concepts, mechanisms and methods are reported for such lobed mixers, such as, "boomerang" scallops, "tongue" mixer, detection of "excess" internal noise sources, and extrapolation of flyover noise data from one flight speed to different flight speeds. Noise reduction of as much as 3 EPNdB was found with a deeply scalloped mixer compared to annular nozzle at net thrust levels of 9500 lb for a 29 in. diameter nozzle after optimizing the nozzle length.

Modern sediment characteristics and accumulation rates from the delta front to prodelta of the Yellow River (Huanghe)

NASA Astrophysics Data System (ADS)

Zhou, Liangyong; Liu, Jian; Saito, Yoshiki; Gao, Maosheng; Diao, Shaobo; Qiu, Jiandong; Pei, Shaofeng

2016-08-01

Since 1976, the main channel of the Yellow River (Huanghe) has been on the east side of the delta complex, and the river has prograded a broad new delta lobe in Laizhou Bay of the Bohai Sea. In 2012, extensive bathymetric and high-resolution seismic profiles were conducted and sediment cores were collected off the new delta lobe. This study examined delta sedimentation and morphology along a profile across the modern subaqueous Yellow River delta and into Laizhou Bay, by analyzing sediment radionuclides (137Cs, 210Pb and 7Be), sedimentary structure, grain-size composition, organic carbon content, and morphological changes between 1976 and 2012. The change in the bathymetric profile, longitudinal to the river's course, reveals subaqueous delta progradation during this period. The subbottom boundary between the new delta lobe sediment and the older seafloor sediment (before the 1976 course shift) was identified in terms of lithology and radionuclide distributions, and recognized as a downlap surface in the seismic record. The accumulation rate of the new delta lobe sediment is estimated to be 5-18.6 cm year-1 on the delta front slope, 2 cm year-1 at the toe of the slope, and 1-2 cm year-1 in the shelf areas of Laizhou Bay. Sediment facies also change offshore, from alternations of gray and brown sediment in the proximal area to gray bioturbated fine sediment in the distal area. Based on 7Be distribution, the shorter-term deposition rate was at least 20 cm year-1 in the delta front.

Flight behavior of the rhinoceros beetle Trypoxylus dichotomus during electrical nerve stimulation.

PubMed

Van Truong, Tien; Byun, Doyoung; Lavine, Laura Corley; Emlen, Douglas J; Park, Hoon Cheol; Kim, Min Jun

2012-09-01

Neuronal stimulation is an intricate part of understanding insect flight behavior and control insect itself. In this study, we investigated the effects of electrical pulses applied to the brain and basalar muscle of the rhinoceros beetle (Trypoxylus dichotomus). To understand specific neuronal stimulation mechanisms, responses and flight behavior of the beetle, four electrodes were implanted into the two optic lobes, the brain's central complex and the ventral nerve cord in the posterior pronotum. We demonstrated flight initiation, turning and cessation by stimulating the brain. The change undergone by the wing flapping in response to the electrical signal was analyzed from a sequence of images captured by a high-speed camera. Here, we provide evidence to distinguish the important differences between neuronal and muscular flight stimulations in beetles. We found that in the neural potential stimulation, both the hind wing and the elytron were suppressed. Interestingly, the beetle stopped flying whenever a stimulus potential was applied between the pronotum and one side of the optic lobe, or between the ventral nerve cord in the posterior pronotum and the central complex. In-depth experimentation demonstrated the effective of neural stimulation over muscle stimulation for flight control. During electrical stimulation of the optic lobes, the beetle performed unstable flight, resulting in alternating left and right turns. By applying the electrical signal into both the optic lobes and the central complex of the brain, we could precisely control the direction of the beetle flight. This work provides an insight into insect flight behavior for future development of insect-micro air vehicle.

Contributions of the Medial Temporal Lobe to Declarative Memory Retrieval: Manipulating the Amount of Contextual Retrieval

ERIC Educational Resources Information Center

Tendolkar, Indira; Arnold, Jennifer; Petersson, Karl Magnus; Weis, Susanne; Brockhaus-Dumke, Anke; van Eijndhoven, Philip; Buitelaar, Jan; Fernandez, Guillen

2008-01-01

We investigated how the hippocampus and its adjacent mediotemporal structures contribute to contextual and noncontextual declarative memory retrieval by manipulating the amount of contextual information across two levels of the same contextual dimension in a source memory task. A first analysis identified medial temporal lobe (MTL) substructures…

Facial recognition in children after perinatal stroke.

PubMed

Ballantyne, A O; Trauner, D A

1999-04-01

To examine the effects of prenatal or perinatal stroke on the facial recognition skills of children and young adults. It was hypothesized that the nature and extent of facial recognition deficits seen in patients with early-onset lesions would be different from that seen in adults with later-onset neurologic impairment. Numerous studies with normal and neurologically impaired adults have found a right-hemisphere superiority for facial recognition. In contrast, little is known about facial recognition in children after early focal brain damage. Forty subjects had single, unilateral brain lesions from pre- or perinatal strokes (20 had left-hemisphere damage, and 20 had right-hemisphere damage), and 40 subjects were controls who were individually matched to the lesion subjects on the basis of age, sex, and socioeconomic status. Each subject was given the Short-Form of Benton's Test of Facial Recognition. Data were analyzed using the Wilcoxon matched-pairs signed-rank test and multiple regression. The lesion subjects performed significantly more poorly than did matched controls. There was no clear-cut lateralization effect, with the left-hemisphere group performing significantly more poorly than matched controls and the right-hemisphere group showing a trend toward poorer performance. Parietal lobe involvement, regardless of lesion side, adversely affected facial recognition performance in the lesion group. Results could not be accounted for by IQ differences between lesion and control groups, nor was lesion severity systematically related to facial recognition performance. Pre- or perinatal unilateral brain damage results in a subtle disturbance in facial recognition ability, independent of the side of the lesion. Parietal lobe involvement, in particular, has an adverse effect on facial recognition skills. These findings suggest that the parietal lobes may be involved in the acquisition of facial recognition ability from a very early point in brain development, but that there is sufficient potential to reorganize or compensate such that the residual deficits, though significant, are subtle.

Hilar cholangiocarcinoma: Cross sectional evaluation of disease spectrum

PubMed Central

Mahajan, Mangal S; Moorthy, Srikanth; Karumathil, Sreekumar P; Rajeshkannan, R; Pothera, Ramchandran

2015-01-01

Although hilar cholangiocarcinoma is relatively rare, it can be diagnosed on imaging by identifying its typical pattern. In most cases, the tumor appears to be centered on the right or left hepatic duct with involvement of the ipsilateral portal vein, atrophy of hepatic lobe on that side, and invasion of adjacent liver parenchyma. Multi-detector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP) are commonly used imaging modalities to assess the longitudinal and horizontal spread of tumor. PMID:25969643

Function Lateralization via Measuring Coherence Laterality

PubMed Central

Wang, Ze; Mechanic-Hamilton, Dawn; Pluta, John; Glynn, Simon; Detre, John A.

2009-01-01

A data-driven approach for lateralization of brain function based on the spatial coherence difference of functional MRI (fMRI) data in homologous regions-of-interest (ROI) in each hemisphere is proposed. The utility of using coherence laterality (CL) to determine function laterality was assessed first by examining motor laterality using normal subjects’ data acquired both at rest and with a simple unilateral motor task and subsequently by examining mesial temporal lobe memory laterality in normal subjects and patients with temporal lobe epilepsy. The motor task was used to demonstrate that CL within motor ROI correctly lateralized functional stimulation. In patients with unilateral epilepsy studied during a scene-encoding task, CL in a hippocampus-parahippocampus-fusiform (HPF) ROI was concordant with lateralization based on task activation, and the CL index (CLI) significantly differentiated the right side group to the left side group. By contrast, normal controls showed a symmetric HPF CLI distribution. Additionally, similar memory laterality prediction results were still observed using CL in epilepsy patients with unilateral seizures after the memory encoding effect was removed from the data, suggesting the potential for lateralization of pathological brain function based on resting fMRI data. A better lateralization was further achieved via a combination of the proposed approach and the standard activation based approach, demonstrating that assessment of spatial coherence changes provides a complementary approach to quantifying task-correlated activity for lateralizing brain function. PMID:19345736

Preliminary study of synthetic aperture tissue harmonic imaging on in-vivo data

NASA Astrophysics Data System (ADS)

Rasmussen, Joachim H.; Hemmsen, Martin C.; Madsen, Signe S.; Hansen, Peter M.; Nielsen, Michael B.; Jensen, Jørgen A.

2013-03-01

A method for synthetic aperture tissue harmonic imaging is investigated. It combines synthetic aperture sequen- tial beamforming (SASB) with tissue harmonic imaging (THI) to produce an increased and more uniform spatial resolution and improved side lobe reduction compared to conventional B-mode imaging. Synthetic aperture sequential beamforming tissue harmonic imaging (SASB-THI) was implemented on a commercially available BK 2202 Pro Focus UltraView ultrasound system and compared to dynamic receive focused tissue harmonic imag- ing (DRF-THI) in clinical scans. The scan sequence that was implemented on the UltraView system acquires both SASB-THI and DRF-THI simultaneously. Twenty-four simultaneously acquired video sequences of in-vivo abdominal SASB-THI and DRF-THI scans on 3 volunteers of 4 different sections of liver and kidney tissues were created. Videos of the in-vivo scans were presented in double blinded studies to two radiologists for image quality performance scoring. Limitations to the systems transmit stage prevented user defined transmit apodization to be applied. Field II simulations showed that side lobes in SASB could be improved by using Hanning transmit apodization. Results from the image quality study show, that in the current configuration on the UltraView system, where no transmit apodization was applied, SASB-THI and DRF-THI produced equally good images. It is expected that given the use of transmit apodization, SASB-THI could be further improved.

Synoptic Formation of Double Tropopauses

NASA Astrophysics Data System (ADS)

Liu, Chengji; Barnes, Elizabeth

2018-01-01

Double tropopauses are ubiquitous in the midlatitude winter hemisphere and represent the vertical stacking of two stable tropopause layers separated by a less stable layer. By analyzing COSMIC GPS data, reanalysis, and eddy life cycle simulations, we demonstrate that they often occur during Rossby wave breaking and act to increase the stratosphere-to-troposphere exchange of mass. We further investigate the adiabatic formation of double tropopauses and propose two mechanisms by which they can occur. The first mechanism operates at the tropopause break in the subtropics where the higher tropical tropopause sits on one side of the break and the lower extratropical tropopause sits on the other. The double tropopauses are then formed by differential meridional advection of the higher and lower tropopauses on the two sides of the tropopause break. We show that anticyclonic wave breaking can form double tropopauses mainly by providing stronger poleward advection of the higher tropopause in its poleward lobe. Cyclonic wave breaking mainly forms double tropopauses by providing stronger equatorward advection of the lower tropopause in its equatorward lobe. We demonstrate in the COSMIC GPS data and reanalysis that about half of the double tropopauses in the Northern Hemisphere winter can be directly attributed to such differential advection. For the second mechanism, adiabatic destabilization of the air above the tropopause contributes to the formation of a double tropopause. In this case, a tropopause inversion layer is necessary for this destabilization to result in a double tropopause.

The error analysis of Lobular and segmental division of right liver by volume measurement.

PubMed

Zhang, Jianfei; Lin, Weigang; Chi, Yanyan; Zheng, Nan; Xu, Qiang; Zhang, Guowei; Yu, Shengbo; Li, Chan; Wang, Bin; Sui, Hongjin

2017-07-01

The aim of this study is to explore the inconsistencies between right liver volume as measured by imaging and the actual anatomical appearance of the right lobe. Five healthy donated livers were studied. The liver slices were obtained with hepatic segments multicolor-infused through the portal vein. In the slices, the lobes were divided by two methods: radiological landmarks and real anatomical boundaries. The areas of the right anterior lobe (RAL) and right posterior lobe (RPL) on each slice were measured using Photoshop CS5 and AutoCAD, and the volumes of the two lobes were calculated. There was no statistically significant difference between the volumes of the RAL or RPL as measured by the radiological landmarks (RL) and anatomical boundaries (AB) methods. However, the curves of the square error value of the RAL and RPL measured using CT showed that the three lowest points were at the cranial, intermediate, and caudal levels. The U- or V-shaped curves of the square error rate of the RAL and RPL revealed that the lowest value is at the intermediate level and the highest at the cranial and caudal levels. On CT images, less accurate landmarks were used to divide the RAL and RPL at the cranial and caudal layers. The measured volumes of hepatic segments VIII and VI would be less than their true values, and the measured volumes of hepatic segments VII and V would be greater than their true values, according to radiological landmarks. Clin. Anat. 30:585-590, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Neural Correlates of Subliminal Language Processing.

PubMed

Axelrod, Vadim; Bar, Moshe; Rees, Geraint; Yovel, Galit

2015-08-01

Language is a high-level cognitive function, so exploring the neural correlates of unconscious language processing is essential for understanding the limits of unconscious processing in general. The results of several functional magnetic resonance imaging studies have suggested that unconscious lexical and semantic processing is confined to the posterior temporal lobe, without involvement of the frontal lobe-the regions that are indispensable for conscious language processing. However, previous studies employed a similarly designed masked priming paradigm with briefly presented single and contextually unrelated words. It is thus possible, that the stimulation level was insufficiently strong to be detected in the high-level frontal regions. Here, in a high-resolution fMRI and multivariate pattern analysis study we explored the neural correlates of subliminal language processing using a novel paradigm, where written meaningful sentences were suppressed from awareness for extended duration using continuous flash suppression. We found that subjectively and objectively invisible meaningful sentences and unpronounceable nonwords could be discriminated not only in the left posterior superior temporal sulcus (STS), but critically, also in the left middle frontal gyrus. We conclude that frontal lobes play a role in unconscious language processing and that activation of the frontal lobes per se might not be sufficient for achieving conscious awareness. © The Author 2014. Published by Oxford University Press.

True memory, false memory, and subjective recollection deficits after focal parietal lobe lesions.

PubMed

Drowos, David B; Berryhill, Marian; André, Jessica M; Olson, Ingrid R

2010-07-01

There is mounting evidence that the posterior parietal cortex (PPC) plays an important role in episodic memory. We previously found that patients with PPC damage exhibit retrieval-related episodic memory deficits. Here we assess whether parietal lobe damage affects episodic memory on a different task: the Deese-Roediger-McDermott (DRM) false-memory paradigm. Two patients with bilateral PPC damage and a group of matched controls were tested. In Experiment 1, the task was to remember words; in Experiment 2 the task was to remember pictures of common objects. Prior studies have shown that normal participants have high levels of false memory to words, low levels to pictures. The patients exhibited significantly lower levels of false memory to words. One patient showed significantly elevated levels of false memory to pictures. The patients' false memories were accompanied by reduced levels of recollection, as tested by a Remember/Know procedure. PPC damage causes decreased levels of false memories and an abnormal Remember/Know profile. Their false memory rate is similar to the rate exhibited by patients with medial temporal lobe damage. These results support the view that portions of the PPC play a critical role in objective and subjective aspects of recollection.

Decreased frontal lobe phosphocreatine levels in methamphetamine users

PubMed Central

Sung, Young-Hoon; Yurgelun-Todd, Deborah A.; Shi, Xian-Feng; Kondo, Douglas G.; Lundberg, Kelly J.; McGlade, Erin C.; Hellem, Tracy L.; Huber, Rebekah S.; Fiedler, Kristen K.; Harrell, Renee E.; Nickerson, Bethany R.; Kim, Seong-Eun; Jeong, Eun-Kee; Renshaw, Perry F.

2012-01-01

BACKGROUND Mitochondria-related mechanisms have been suggested to mediate methamphetamine (METH) toxicity. However, changes in brain energetics associated with highenergy phosphate metabolism have not been investigated in METH users. Phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) was used to evaluate changes in mitochondrial high energy phosphates, including phosphocreatine (PCr) and β-nucleoside triphosphate (β-NTP, primarily ATP in brain) levels. We hypothesized that METH users would have decreased high-energy PCr levels in the frontal gray matter. METHODS Study participants consisted of 51 METH (age=32.8±6.7) and 23 healthy comparison (age=31.1±7.5) subjects. High-energy phosphate metabolite levels were compared between the groups and potential gender differences were explored. RESULTS METH users had lower ratios of PCr to total pool of exchangeable phosphate (PCr/TPP) in the frontal lobe as compared to the healthy subjects (p=0.001). The lower PCr levels in METH subjects were significantly associated with lifetime amount of METH use (p=0.003). A sub-analysis for gender differences revealed that female METH users, who had lower daily amounts (1.1±1.0 gram) of METH use than males (1.4±1.7 gram), had significantly lower PCr/TPP ratios than male METH users, controlling for the amount of METH use (p=0.02). CONCLUSIONS The present findings suggest that METH compromises frontal lobe high-energy phosphate metabolism in a dose-responsive manner. Our findings also suggest that the abnormality in frontal lobe high-energy phosphate metabolism might be more prominent in female than in male METH users. This is significant as decreased PCr levels have been associated with depressive symptoms, and poor responses to antidepressant treatment have been reported in those with decreased PCr levels. PMID:23084413

Contribution of frontal and temporal lobe function to memory interference from divided attention at retrieval.

PubMed

Fernandes, Myra A; Davidson, Patrick S R; Glisky, Elizabeth L; Moscovitch, Morris

2004-07-01

On the basis of their scores on composite measures of frontal and temporal lobe function, derived from neuropsychological testing, seniors were divided preexperimentally into 4 groups. Participants studied a list of unrelated words under full attention and recalled them while concurrently performing an animacy decision task to words, an odd-digit identification task to numbers, or no distracting task. Large interference effects on memory were produced by the animacy but not by the odd-digit distracting task, and this pattern was not influenced by level of frontal or temporal lobe function. Results show associative retrieval is largely disrupted by competition for common representations, and it is not affected by a reduction in general processing resources, attentional capacity, or competition for memory structures in the temporal lobe.

Variations and asymmetries in regional brain surface in the genus Homo.

PubMed

Balzeau, Antoine; Holloway, Ralph L; Grimaud-Hervé, Dominique

2012-06-01

Paleoneurology is an important field of research within human evolution studies. Variations in size and shape of an endocast help to differentiate among fossil hominin species whereas endocranial asymmetries are related to behavior and cognitive function. Here we analyse variations of the surface of the frontal, parieto-temporal and occipital lobes among different species of Homo, including 39 fossil hominins, ten fossil anatomically modern Homo sapiens and 100 endocasts of extant modern humans. We also test for the possible asymmetries of these features in a large sample of modern humans and observe individual particularities in the fossil specimens. This study contributes important new information about the brain evolution in the genus Homo. Our results show that the general pattern of surface asymmetry for the different regional brain surfaces in fossil species of Homo does not seem to be different from the pattern described in a large sample of anatomically modern H. sapiens, i.e., the right hemisphere has a larger surface than the left, as do the right frontal, the right parieto-temporal and the left occipital lobes compared with the contra-lateral side. It also appears that Asian Homo erectus specimens are discriminated from all other samples of Homo, including African and Georgian specimens that are also sometimes included in that taxon. The Asian fossils show a significantly smaller relative size of the parietal and temporal lobes. Neandertals and anatomically modern H. sapiens, who share the largest endocranial volume of all hominins, show differences when considering the relative contribution of the frontal, parieto-temporal and occipital lobes. These results illustrate an original variation in the pattern of brain organization in hominins independent of variations in total size. The globularization of the brain and the enlargement of the parietal lobes could be considered derived features observed uniquely in anatomically modern H. sapiens. Copyright © 2012 Elsevier Ltd. All rights reserved.

Three-dimensional vasculature of the bovine liver.

PubMed

Shirai, W; Sato, T; Shibuya, H; Naito, K; Tsukise, A

2005-12-01

To clarify anatomical distribution of Fasciola infection, the vascular and ductal architectures of the liver were studied by means of corrosion cast technique using synthetic resin. The arteria hepatica propria (AP) passes as the arteria gastroduodenalis (AG); AP becomes the left trunk after the porta hepatis; AP passes on the right side of vena porta communis (VPC) and projects AG while curving in a U-shape below the portal vein. Hepatic veins located between the vena hepatica media (HM) and vena hepatica dextra (HD) varied widely among specimens and were irregular, including the vena hepatica dorso-lateralis sinistra (Hds), vena hepatica dorso-lateralis dextra (Hdd), vena hepatica lobi caudati (Hlc), venae hepaticae processus caudati (Hpc), venae hepaticae processus papillaris (Hpp), and the hepatic vein to the dorsal intermediate part, which directly or indirectly drained into the vena cava caudalis. The courses of the bovine hepatic veins were markedly diverse, and anastomoses between vena hepatica sinistra (HS) and Hds were observed in about a half of the livers. The portal vein entered the liver as VPC slightly above the centre of the right lobe on the visceral surface. The intermediate or transverse part [pars transversa trunci sinistri (PTS)] of truncus sinister (TS), which extends from the entry of the portal vein into the left lobe of the liver, was slightly arched downward [pars umbilicalis trunci sinistri (PUS)]. The portal vein further arched from the distal end of TS to the umbilical vein and ran towards the inter-lobar incision between the left lobe and quadrate lobe. Based on these branches, hepatic segments were determined as 13 or 14 areas. A total of 15 bile ducts were derived from various lobes. The hepatic duct was about 2.6-6 cm long from the confluence of the right and left hepatic ducts to the division of the cystic duct and the common hepatic duct.

Single-voxel and multi-voxel spectroscopy yield comparable results in the normal juvenile canine brain when using 3 Tesla magnetic resonance imaging.

PubMed

Lee, Alison M; Beasley, Michaela J; Barrett, Emerald D; James, Judy R; Gambino, Jennifer M

2018-06-10

Conventional magnetic resonance imaging (MRI) characteristics of canine brain diseases are often nonspecific. Single- and multi-voxel spectroscopy techniques allow quantification of chemical biomarkers for tissues of interest and may help to improve diagnostic specificity. However, published information is currently lacking for the in vivo performance of these two techniques in dogs. The aim of this prospective, methods comparison study was to compare the performance of single- and multi-voxel spectroscopy in the brains of eight healthy, juvenile dogs using 3 Tesla MRI. Ipsilateral regions of single- and multi-voxel spectroscopy were performed in symmetric regions of interest of each brain in the parietal (n = 3), thalamic (n = 2), and piriform lobes (n = 3). In vivo single-voxel spectroscopy and multi-voxel spectroscopy metabolite ratios from the same size and multi-voxel spectroscopy ratios from different sized regions of interest were compared. No significant difference was seen between single-voxel spectroscopy and multi-voxel spectroscopy metabolite ratios for any lobe when regions of interest were similar in size and shape. Significant lobar single-voxel spectroscopy and multi-voxel spectroscopy differences were seen between the parietal lobe and thalamus (P = 0.047) for the choline to N-acetyl aspartase ratios when large multi-voxel spectroscopy regions of interest were compared to very small multi-voxel spectroscopy regions of interest within the same lobe; and for the N-acetyl aspartase to creatine ratios in all lobes when single-voxel spectroscopy was compared to combined (pooled) multi-voxel spectroscopy datasets. Findings from this preliminary study indicated that single- and multi-voxel spectroscopy techniques using 3T MRI yield comparable results for similar sized regions of interest in the normal canine brain. Findings also supported using the contralateral side as an internal control for dogs with brain lesions. © 2018 American College of Veterinary Radiology.

LMI1-like genes involved in leaf margin development of Brassica napus.

PubMed

Ni, Xiyuan; Liu, Han; Huang, Jixiang; Zhao, Jianyi

2017-06-01

In rapeseed (Brassica napus L.), leaf margins are variable and can be entire, serrate, or lobed. In our previous study, the lobed-leaf gene (LOBED-LEAF 1, BnLL1) was mapped to a 32.1 kb section of B. napus A10. Two LMI1-like genes, BnaA10g26320D and BnaA10g26330D, were considered the potential genes that controlled the lobed-leaf trait in rapeseed. In the present study, these two genes and another homologous gene (BnaC04g00850D) were transformed into Arabidopsis thaliana (L.) Heynh. plants to identify their functions. All three LMI1-like genes of B. napus produced serrate leaf margins. The expression analysis indicated that the expression level of BnaA10g26320D determined the difference between lobed- and entire-leaved lines in rapeseed. Therefore, it is likely that BnaA10g26320D corresponds to BnLL1.

RAiSE III: 3C radio AGN energetics and composition

NASA Astrophysics Data System (ADS)

Turner, Ross J.; Shabala, Stanislav S.; Krause, Martin G. H.

2018-03-01

Kinetic jet power estimates based exclusively on observed monochromatic radio luminosities are highly uncertain due to confounding variables and a lack of knowledge about some aspects of the physics of active galactic nuclei (AGNs). We propose a new methodology to calculate the jet powers of the largest, most powerful radio sources based on combinations of their size, lobe luminosity, and shape of their radio spectrum; this approach avoids the uncertainties encountered by previous relationships. The outputs of our model are calibrated using hydrodynamical simulations and tested against independent X-ray inverse-Compton measurements. The jet powers and lobe magnetic field strengths of radio sources are found to be recovered using solely the lobe luminosity and spectral curvature, enabling the intrinsic properties of unresolved high-redshift sources to be inferred. By contrast, the radio source ages cannot be estimated without knowledge of the lobe volumes. The monochromatic lobe luminosity alone is incapable of accurately estimating the jet power or source age without knowledge of the lobe magnetic field strength and size, respectively. We find that, on average, the lobes of the Third Cambridge Catalogue of Radio Sources (3C) have magnetic field strengths approximately a factor three lower than the equipartition value, inconsistent with equal energy in the particles and the fields at the 5σ level. The particle content of 3C radio lobes is discussed in the context of complementary observations; we do not find evidence favouring an energetically dominant proton population.

Modified temporal approach for a rostro-temporal basal meningioma in a cat.

PubMed

Forterre, Franck; Jaggy, André; Rohrbach, Helene; Dickomeit, Marc; Konar, Martin

2009-06-01

An 11-year-old neutered female domestic shorthair indoor cat was presented to our hospital for treatment of a left-sided rostro-temporal basal meningioma. Focal seizures in the facial muscles had been observed sporadically for 1 year. Two weeks prior to presentation the cat had developed generalised seizures and was treated with symptomatic anticonvulsive treatment. Focal facial seizures, especially on the right side, persisted after medical therapy. From the computed tomography scan, a basal meningioma was suspected by the treating veterinarian. A left-sided suprazygomatical temporobasal approach to the zygomatic arch was chosen because it causes less soft tissue damage. After craniotomy, durotomy and gentle dorsal retraction of the left piriform lobe, the meningioma was removed. Postoperative magnetic resonance imaging confirmed complete excision of the tumour. One day after surgery the cat was alert and a left-sided facial nerve palsy was noticed. Otherwise the neurological examination was normal. Anticonvulsive and eye moistening therapy was continued for 3 months. Six months after surgery the cat was clinically normal without any recurrence of seizures.

A young infant with musicogenic epilepsy.

PubMed

Lin, Kuang-Lin; Wang, Huei-Shyong; Kao, Pan-Fu

2003-05-01

Musicogenic epilepsy is a relatively rare form of epilepsy. In its pure form, it is characterized by epileptic seizures that are provoked exclusively by listening to music. The usual type of seizure is partial complex or generalized tonic-clonic. Precipitating factors are quite specific, such as listening to only one composition or the actual playing of music on an instrument. However, simple sound also can be a trigger. We report a 6-month-old infant with musicogenic epilepsy. She manifested right-sided focal seizures with occasional generalization. The seizures were frequently triggered by loud music, especially that by the Beatles. The interictal electroencephalography results were normal. Ictal spikes were present throughout the left temporal area during continuous electroencephalograpic monitoring. Brain magnetic resonance imaging results were normal, whereas single-photon emission computed tomography of the brain revealed hypoperfusion of the left temporal area. The young age and epileptogenic left temporal lobe lesion in this patient with musicogenic epilepsy were unusual characteristics. Theoretically, three levels of integration are involved in music processing in the brain. The involved integration of this infant's brain may be the sensory level rather than the emotional level. Nevertheless, the personal musicality and musical style of the Beatles might play an important role in this patient's epilepsy.

Islets of Langerhans in the parakeet, Psittacula krameri.

PubMed

Gupta, Y K; Kumar, S

1980-01-01

The pancreatic gland of Psittacula krameri is divisible into 4 lobes i.e. dorsal, ventral, third and splenic. The endocrine part is composed of alpha 1-, alpha 2- and beta-cells. The islets are of 4 kinds viz., alpha islets (having alpha 1- and alpha 2-cells), beta islets (having beta- and alpha 1-cells), pure beta islets (consisting of beta-cells exclusively) and mixed islets (with beta-, alpha 1- and alpha 2-cells). The distribution of alpha islets is mostly restricted to the splenic and third lobes whereas the beta islets are found in all 4 lobes. Though the alpha islets are only few in the dorsal lobe, their size is best developed in the third and dorsal lobes. Sometimes beta and alpha islets are present in very close proximity but their cells never mingle. An interesting feature was the complete absence of alpha islets from the ventral lobe.A relative abundance of alpha 2- cells in this bird seems to be associated with its comparatively higher blood glucose level and frugivorous habit. Tinctorial reactions suggest that the insulin content of the endocrine pancreas is low. There were no seasonal changes in the islet tissue of P. krameri.

Verbal Memory Compensation: Application to Left and Right Temporal Lobe Epileptic Patients

ERIC Educational Resources Information Center

Bresson, Christel; Lespinet-Najib, Veronique; Rougier, Alain; Claverie, Bernard; N'Kaoua, Bernard

2007-01-01

This study investigates the compensatory impact of cognitive aids on left and right temporal lobe epileptic patients suffering from verbal memory disorders, who were candidates for surgery. Cognitive aids are defined in the levels-of-processing framework and deal with the depth of encoding, the elaboration of information, and the use of retrieval…

Apolipoprotein E in Temporal Lobe Epilepsy: A Case-Control Study

PubMed Central

Kumar, Amit; Tripathi, Manjari; Pandey, Ravindra M.; Ramakrishnan, Lakshmy; Srinivas, M.; Luthra, Kalpana

2006-01-01

Purpose: To investigate the relationship of apolipoprotein E (apoE) genotype, plasma levels of apoE and lipids in temporal lobe epilepsy (TLE) patients in Asian Indians. Status of plasma levels of Apo E in epilepsy patients has not been reported till date. Methods: ApoE gene polymorphism was analyzed in 58 patients with temporal lobe epilepsy (TLE) and 57 age and sex approximated controls using Polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Levels of plasma apoE and lipids were measured using ELISA and enzymatic kits respectively. Results: The distribution of ApoE genotype in epilepsy patients and controls was comparable. Higher levels of plasma ApoE were observed in TLE patients as compared to controls (p = 0.0001). Individuals with plasma levels of apoE > 190 mg/L were at 20 times higher odds (95%CI = 2.46–163.34, p = 0.005), while those with levels of apoE between 150–190 mg/L were at 4.9 times higher odds (95% CI = 1.85–13.9, p = 0.001), to develop TLE. Conclusions: We have observed for the first time, high levels of plasma apoE in epilepsy patients. The findings of this case-control study suggest that apolipoprotein E may play an important role in epilepsy. PMID:17264404

Test-retest reliability of diffusion tensor imaging of the liver at 3.0 T.

PubMed

Girometti, Rossano; Maieron, Marta; Lissandrello, Giovanni; Bazzocchi, Massimo; Zuiani, Chiara

2015-06-01

This study was done to evaluate test-retest reliability of liver diffusion tensor imaging (LDTI). Ten healthy volunteers (median age 23 years) underwent two LDTI scans on a 3.0 T magnet during two imaging sessions separated by 2 weeks (session-1/-2, respectively). Fifteen gradient directions and b values of 0-1,000 s/mm(2) were used. Two radiologists in consensus assessed liver apparent diffusion coefficient (ADC) and fraction of anisotropy (FA) values on ADC and FA maps at four reference levels, namely: right upper level (RUL), right lower level (RLL), left upper level (LUL) and left lower level (LLL). We then assessed (a) whether ADC and FA values overlapped when measured on different levels within the same imaging session or between different imaging sessions; (b) the degree of variability on an intra-session and inter-session basis, respectively, using the coefficient of variation (CV). In sessions 1 and 2, the ADC/FA values were significantly larger in the left liver lobe (LUL/LLL) compared to right liver lobe (RUL/RLL) (p < 0.05/6). Intra-session CVs were 9.51 % (session 1) and 9.73 % (session 2) for ADC, and 12.93 % (session 1) and 11.82 % (session 2) for FA, respectively. When comparing RUL, RLL, LUL and LLL on an inter-session basis, CVs were 6.52, 8.20, 6.52 and 11.06 % for ADC, and 15.42, 15.80, 15.42 and 6.80 % for FA, respectively. LDTI provides consistent and repeatable measurements. However, since larger left lobe ADC/FA values can be attributed to artefacts, right lobe values should be considered the most reliable measurements of water diffusivity within the liver.

Yuty Crater Ejecta

NASA Image and Video Library

2018-03-26

Off the image to the right is Yuty Crater, located between Simud and Tiu Valles. The crater ejcta forms the large lobes along the right side of this VIS image. This type of ejecta was created by surface flow rather than air fall. It is thought that the near surface materials contained volatiles (like water) which mixed with the ejecta at the time of the impact. Orbit Number: 68736 Latitude: 22.247 Longitude: 325.213 Instrument: VIS Captured: 2017-06-12 17:57 https://photojournal.jpl.nasa.gov/catalog/PIA22303

Sparse aperiodic arrays for optical beam forming and LIDAR.

PubMed

Komljenovic, Tin; Helkey, Roger; Coldren, Larry; Bowers, John E

2017-02-06

We analyze optical phased arrays with aperiodic pitch and element-to-element spacing greater than one wavelength at channel counts exceeding hundreds of elements. We optimize the spacing between waveguides for highest side-mode suppression providing grating lobe free steering in full visible space while preserving the narrow beamwidth. Optimum waveguide placement strategies are derived and design guidelines for sparse (> 1.5 λ and > 3 λ average element spacing) optical phased arrays are given. Scaling to larger array areas by means of tiling is considered.

Diffraction effects on angular response of X-ray collimators

NASA Technical Reports Server (NTRS)

Blake, R. L.; Barrus, D. M.; Fenimore, E.

1976-01-01

Angular responses have been measured for X-ray collimators with half-widths ranging from minutes of arc down to 10 arcsec. In the seconds-of-arc range, diffraction peaks at off-axis angles can masquerade as side lobes of the collimator angular response. Measurements and qualitative physical arguments lead to a rule of thumb for collimator design; namely, the angle of first minimum in the Fraunhofer single-slit diffraction pattern should be less than one-fourth of the collimator geometrical full-width at half-maximum intensity.

Right Dorsolateral Frontal Lobe N-Acetyl Aspartate and Myoinositol Concentration Estimation in Type 2 Diabetes with Magnetic Resonance Spectroscopy.

PubMed

Nagothu, Rajani Santhakumari; Reddy, Yogananda Indla; Rajagopalan, Archana; Varma, Ravi

2015-07-01

Chronic hyperglycaemia in type 2 diabetes, effects the central nervous system by altering the concentrations of brain metabolites like N-acetyl aspartate (NAA) and myoinositol (mI), which are indicators of neuronal integrity and glial cell damage respectively. Dorsolateral frontal lobe is associated with aspects of cognition especially right frontal lobe is involved in episodic memory retrieval, ninety percent of the diabetic cases are type 2 in nature globally and yoga is very effective in stabilizing the brain metabolites by bringing the blood glucose levels to near or within the physiological range in type 2 diabetes. The aim of the study was to observe the effects of yogasana and pranayama on glycosilated haemoglobin (HbA1c) levels and right dorsolateral frontal cortical NAA and mI concentration in type 2 diabetic subjects. It's a case control study. Sixty eight type 2 diabetic subjects of both the sex, aged between 35-65 years are included in the study, subjects are divided in to test and control group 34 each. Test group subjects did the yogasana and pranayama for a period of 6 months, 6 days in a week, 45-60 minutes daily under the supervision of a qualified yoga teacher. Control group subjects are not on any specific exercise regimen. Both the group subjects are taking oral hypoglycaemic agents. HbA1c levels are measured using the Bio-Rad D-10™ haemoglobin A1c program and Magnetic Resonance Spectroscopy (MRS) is used in assessing the metabolite concentrations. Analysis of data was done by using unpaired t-test. P-value for HbA1c level is <0.001, which is highly significant statistically. P-value for NAA was < 0.02 and for myoinositol was < 0.01, which are statistically significant. HbA1c levels in control and test group subjects are 7.7 ± 1.84 and 6.02 ± 0.46 respectively. NAA concentrations in the right dorsolateral frontal lobe of control and test group are 1.44 ± 0.15 and 1.54 ± 0.19 respectively. The mI concentrations in the right dorsolateral frontal lobe of control and test group are 0.61 ± 0.22 and 0.47 ± 0.24 respectively. Yogasana and pranayama minimized the neuronal and glial cellular damage in test group, which is evident by minimal changes in right dorsolateral frontal lobe NAA and mI levels in type 2 diabetic subjects.

Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures.

PubMed

Lam, Alice D; Zepeda, Rodrigo; Cole, Andrew J; Cash, Sydney S

2016-10-01

Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these 'scalp-negative seizures' is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer's disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hyperphosphorylated tau in patients with refractory epilepsy correlates with cognitive decline: a study of temporal lobe resections.

PubMed

Tai, Xin You; Koepp, Matthias; Duncan, John S; Fox, Nick; Thompson, Pamela; Baxendale, Sallie; Liu, Joan Y W; Reeves, Cheryl; Michalak, Zuzanna; Thom, Maria

2016-09-01

SEE BERNASCONI DOI101093/AWW202 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Temporal lobe epilepsy, the most prevalent form of chronic focal epilepsy, is associated with a high prevalence of cognitive impairment but the responsible underlying pathological mechanisms are unknown. Tau, the microtubule-associated protein, is a hallmark of several neurodegenerative diseases including Alzheimer's disease and chronic traumatic encephalopathy. We hypothesized that hyperphosphorylated tau pathology is associated with cognitive decline in temporal lobe epilepsy and explored this through clinico-pathological study. We first performed pathological examination on tissue from 33 patients who had undergone temporal lobe resection between ages 50 and 65 years to treat drug-refractory temporal lobe epilepsy. We identified hyperphosphorylated tau protein using AT8 immunohistochemistry and compared this distribution to Braak patterns of Alzheimer's disease and patterns of chronic traumatic encephalopathy. We quantified tau pathology using a modified tau score created specifically for analysis of temporal lobectomy tissue and the Braak staging, which was limited without extra-temporal brain areas available. Next, we correlated tau pathology with pre- and postoperative cognitive test scores and clinical risk factors including age at time of surgery, duration of epilepsy, history of secondary generalized seizures, history of head injury, handedness and side of surgery. Thirty-one of 33 cases (94%) showed hyperphosphorylated tau pathology in the form of neuropil threads and neurofibrillary tangles and pre-tangles. Braak stage analysis showed 12% of our epilepsy cohort had a Braak staging III-IV compared to an age-matched non-epilepsy control group from the literature (8%). We identified a mixture of tau pathology patterns characteristic of Alzheimer's disease and chronic traumatic encephalopathy. We also found unusual patterns of subpial tau deposition, sparing of the hippocampus and co-localization with mossy fibre sprouting, a feature of temporal lobe epilepsy. We demonstrated that the more extensive the tau pathology, the greater the decline in verbal learning (Spearman correlation, r = -0.63), recall (r = -0.44) and graded naming test scores (r = -0.50) over 1-year post-temporal lobe resection (P < 0.05). This relationship with tau burden was also present when examining decline in verbal learning from 3 months to 1 year post-resection (r = -0.54). We found an association between modified tau score and history of secondary generalized seizures (likelihood-ratio χ(2), P < 0.05) however there was no clear relationship between tau pathology and other clinical risk factors assessed. Our findings suggest an epilepsy-related tauopathy in temporal lobe epilepsy, which contributes to accelerated cognitive decline and has diagnostic and treatment implications. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hyperphosphorylated tau in patients with refractory epilepsy correlates with cognitive decline: a study of temporal lobe resections

PubMed Central

Tai, Xin You; Koepp, Matthias; Duncan, John S.; Fox, Nick; Thompson, Pamela; Baxendale, Sallie; Liu, Joan Y. W.; Reeves, Cheryl; Michalak, Zuzanna

2016-01-01

Abstract See Bernasconi (doi:10.1093/aww202) for a scientific commentary on this article. Temporal lobe epilepsy, the most prevalent form of chronic focal epilepsy, is associated with a high prevalence of cognitive impairment but the responsible underlying pathological mechanisms are unknown. Tau, the microtubule-associated protein, is a hallmark of several neurodegenerative diseases including Alzheimer’s disease and chronic traumatic encephalopathy. We hypothesized that hyperphosphorylated tau pathology is associated with cognitive decline in temporal lobe epilepsy and explored this through clinico-pathological study. We first performed pathological examination on tissue from 33 patients who had undergone temporal lobe resection between ages 50 and 65 years to treat drug-refractory temporal lobe epilepsy. We identified hyperphosphorylated tau protein using AT8 immunohistochemistry and compared this distribution to Braak patterns of Alzheimer’s disease and patterns of chronic traumatic encephalopathy. We quantified tau pathology using a modified tau score created specifically for analysis of temporal lobectomy tissue and the Braak staging, which was limited without extra-temporal brain areas available. Next, we correlated tau pathology with pre- and postoperative cognitive test scores and clinical risk factors including age at time of surgery, duration of epilepsy, history of secondary generalized seizures, history of head injury, handedness and side of surgery. Thirty-one of 33 cases (94%) showed hyperphosphorylated tau pathology in the form of neuropil threads and neurofibrillary tangles and pre-tangles. Braak stage analysis showed 12% of our epilepsy cohort had a Braak staging III-IV compared to an age-matched non-epilepsy control group from the literature (8%). We identified a mixture of tau pathology patterns characteristic of Alzheimer’s disease and chronic traumatic encephalopathy. We also found unusual patterns of subpial tau deposition, sparing of the hippocampus and co-localization with mossy fibre sprouting, a feature of temporal lobe epilepsy. We demonstrated that the more extensive the tau pathology, the greater the decline in verbal learning (Spearman correlation, r = −0.63), recall (r = −0.44) and graded naming test scores (r = −0.50) over 1-year post-temporal lobe resection (P < 0.05). This relationship with tau burden was also present when examining decline in verbal learning from 3 months to 1 year post-resection (r = −0.54). We found an association between modified tau score and history of secondary generalized seizures (likelihood-ratio χ2, P < 0.05) however there was no clear relationship between tau pathology and other clinical risk factors assessed. Our findings suggest an epilepsy-related tauopathy in temporal lobe epilepsy, which contributes to accelerated cognitive decline and has diagnostic and treatment implications. PMID:27497924

Partial anomalous pulmonary venous connection with suspected pulmonary hypertension in a cat.

PubMed

Nicolson, Geoff; Daley, Michael; Makara, Mariano; Beijerink, Niek

2015-12-01

Partial anomalous pulmonary venous connection has previously been reported in the dog, but never in a cat. A 14-month-old Devon Rex cat was presented for echocardiography to evaluate a heart murmur noticed during a routine examination. The pertinent finding was right-sided cardiomegaly in the absence of an atrial septal defect or tricuspid regurgitation; pulmonary hypertension was suspected. A thoracic computed tomographic angiography study identified a partial anomalous pulmonary venous connection with the lobar veins of the left caudal, right middle, right caudal and accessory lung lobes draining into the caudal vena cava. The resultant volume overload is an easily overlooked differential diagnosis for right-sided cardiac enlargement. This is the first such report of this anomaly in a cat. Copyright © 2015 Elsevier B.V. All rights reserved.

Deterioration of dyslexia after non-dominant temporal lobectomy for drug-resistant epilepsy.

PubMed

Haeren, Roel H L; Hendriks, Marc P H; Vlooswijk, Marielle; Verdyck, Lex; van Kranen-Mastenbroek, Vivianne H J M; Wagner, Louis; van Benthum, Sophie; Schijns, Olaf E M G

2016-03-01

We present a patient with drug-resistant right-sided temporal lobe epilepsy, caused by a ganglioglioma of the parahippocampal gyrus. Preoperatively, the patient was also known to have dyslexia. A right-sided anterior temporal lobectomy, including complete lesionectomy, was performed. Several months after the otherwise uncomplicated procedure, the patient complained about visual memory disturbances, accompanied by increased reading and spelling problems. Postoperative neuropsychological examination revealed deterioration of the visual memory functions, compared to the preoperative assessment, and consequently provided a possible explanation for worsening of the pre-existing dyslexia. In this case report, we hypothesize on the cause of this unusual deterioration and present recommendations to be included in the preoperative epilepsy surgery evaluation for patients with verbal or reading disorders such as dyslexia.

Counterfactual cognitive deficit in persons with Parkinson's disease

PubMed Central

McNamara, P; Durso, R; Brown, A; Lynch, A

2003-01-01

Background: Counterfactuals are mental representations of alternatives to past events. Recent research has shown them to be important for other cognitive processes, such as planning, causal reasoning, problem solving, and decision making—all processes independently linked to the frontal lobes. Objective: To test the hypothesis that counterfactual thinking is impaired in some patients with Parkinson's disease and is linked to frontal dysfunction in these patients. Methods. Measures of counterfactual processing and frontal lobe functioning were administered to 24 persons with Parkinson's disease and 15 age matched healthy controls. Results. Patients with Parkinson's disease spontaneously generated significantly fewer counterfactuals than controls despite showing no differences from controls on a semantic fluency test; they also performed at chance levels on a counterfactual inference test, while age matched controls performed above chance levels on this test. Performance on both the counterfactual generation and inference tests correlated significantly with performance on two tests traditionally linked to frontal lobe functioning (Stroop colour–word interference and Tower of London planning tasks) and one test of pragmatic social communication skills. Conclusions: Counterfactual thinking is impaired in Parkinson's disease. This impairment may be related to frontal lobe dysfunction. PMID:12876235

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.

Verbal learning and memory outcome in selective amygdalohippocampectomy versus temporal lobe resection in patients with hippocampal sclerosis.

PubMed

Foged, Mette Thrane; Vinter, Kirsten; Stauning, Louise; Kjær, Troels W; Ozenne, Brice; Beniczky, Sándor; Paulson, Olaf B; Madsen, Flemming Find; Pinborg, Lars H

2018-02-01

With the advent of new very selective techniques like thermal laser ablation to treat drug-resistant focal epilepsy, the controversy of resection size in relation to seizure outcome versus cognitive deficits has gained new relevance. The purpose of this study was to test the influence of the selective amygdalohippocampectomy (SAH) versus nonselective temporal lobe resection (TLR) on seizure outcome and cognition in patients with mesial temporal lobe epilepsy (MTLE) and histopathological verified hippocampal sclerosis (HS). We identified 108 adults (>16years) with HS, operated between 1995 and 2009 in Denmark. Exclusion criteria are the following: Intelligence below normal range, right hemisphere dominance, other native languages than Danish, dual pathology, and missing follow-up data. Thus, 56 patients were analyzed. The patients were allocated to SAH (n=22) or TLR (n=34) based on intraoperative electrocorticography. Verbal learning and verbal memory were tested pre- and postsurgery. Seizure outcome did not differ between patients operated using the SAH versus the TLR at 1year (p=0.951) nor at 7years (p=0.177). Verbal learning was more affected in patients resected in the left hemisphere than in the right (p=0.002). In patients with left-sided TLR, a worsening in verbal memory performance was found (p=0.011). Altogether, 73% were seizure-free for 1year and 64% for 7years after surgery. In patients with drug-resistant focal MTLE, HS and no magnetic resonance imaging (MRI) signs of dual pathology, selective amygdalohippocampectomy results in sustained seizure freedom and better memory function compared with patients operated with nonselective temporal lobe resection. Copyright © 2017 Elsevier Inc. All rights reserved.

Design for high-power, single-lobe, grating-surface-emitting quantum cascade lasers enabled by plasmon-enhanced absorption of antisymmetric modes

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

Sigler, C.; Kirch, J. D.; Mawst, L. J.

2014-03-31

Resonant coupling of the transverse-magnetic polarized (guided) optical mode of a quantum-cascade laser (QCL) to the antisymmetric surface-plasmon modes of 2nd-order distributed-feedback (DFB) metal/semiconductor gratings results in strong antisymmetric-mode absorption. In turn, lasing in the symmetric mode, that is, surface emission in a single-lobe far-field beam pattern, is strongly favored over controllable ranges in grating duty cycle and tooth height. By using core-region characteristics of a published 4.6 μm-emitting QCL, grating-coupled surface-emitting (SE) QCLs are analyzed and optimized for highly efficient single-lobe operation. For infinite-length devices, it is found that when the antisymmetric mode is resonantly absorbed, the symmetric mode hasmore » negligible absorption loss (∼0.1 cm{sup −1}) while still being efficiently outcoupled, through the substrate, by the DFB grating. For finite-length devices, 2nd-order distributed Bragg reflector (DBR) gratings are used on both sides of the DFB grating to prevent uncontrolled reflections from cleaved facets. Equations for the threshold-current density and the differential quantum efficiency of SE DFB/DBR QCLs are derived. For 7 mm-long, 8.0 μm-wide, 4.6 μm-emitting devices, with an Ag/InP grating of ∼39% duty cycle, and ∼0.22 μm tooth height, threshold currents as low as 0.45 A are projected. Based on experimentally obtained internal efficiency values from high-performance QCLs, slope efficiencies as high as 3.4 W/A are projected; thus, offering a solution for watt-range, single-lobe CW operation from SE, mid-infrared QCLs.« less

Visual cortex activation in kinesthetic guidance of reaching.

PubMed

Darling, W G; Seitz, R J; Peltier, S; Tellmann, L; Butler, A J

2007-06-01

The purpose of this research was to determine the cortical circuit involved in encoding and controlling kinesthetically guided reaching movements. We used (15)O-butanol positron emission tomography in ten blindfolded able-bodied volunteers in a factorial experiment in which arm (left/right) used to encode target location and to reach back to the remembered location and hemispace of target location (left/right side of midsagittal plane) varied systematically. During encoding of a target the experimenter guided the hand to touch the index fingertip to an external target and then returned the hand to the start location. After a short delay the subject voluntarily moved the same hand back to the remembered target location. SPM99 analysis of the PET data contrasting left versus right hand reaching showed increased (P < 0.05, corrected) neural activity in the sensorimotor cortex, premotor cortex and posterior parietal lobule (PPL) contralateral to the moving hand. Additional neural activation was observed in prefrontal cortex and visual association areas of occipital and parietal lobes contralateral and ipsilateral to the reaching hand. There was no statistically significant effect of target location in left versus right hemispace nor was there an interaction of hand and hemispace effects. Structural equation modeling showed that parietal lobe visual association areas contributed to kinesthetic processing by both hands but occipital lobe visual areas contributed only during dominant hand kinesthetic processing. This visual processing may also involve visualization of kinesthetically guided target location and use of the same network employed to guide reaches to visual targets when reaching to kinesthetic targets. The present work clearly demonstrates a network for kinesthetic processing that includes higher visual processing areas in the PPL for both upper limbs and processing in occipital lobe visual areas for the dominant limb.

Density Fluctuation in Asymmetric Nozzle Plumes and Correlation with Far Field Noise

NASA Technical Reports Server (NTRS)

Panda, J.; Zaman, K. B. M. Q.

2001-01-01

A comparative experimental study of air density fluctuations in the unheated plumes of a circular, 4-tabbed-circular, chevron-circular and 10-lobed rectangular nozzles was performed at a fixed Mach number of 0.95 using a recently developed Rayleigh scattering based technique. Subsequently, the flow density fluctuations are cross-correlated with the far field sound pressure fluctuations to determine sources for acoustics emission. The nearly identical noise spectra from the baseline circular and the chevron nozzles are found to be in agreement with the similarity in spreading, turbulence fluctuations, and flow-sound correlations measured in the plumes. The lobed nozzle produced the least low frequency noise, in agreement with the weakest overall density fluctuations and flow-sound correlation. The tabbed nozzle took an intermediate position in the hierarchy of noise generation, intensity of turbulent fluctuation and flow-sound correlation. Some of the features in the 4-tabbed nozzle are found to be explainable in terms of splitting of the jet in a central large core and 4 side jetlets.

Evolutionary Beamforming Optimization for Radio Frequency Charging in Wireless Rechargeable Sensor Networks

PubMed Central

Yao, Ke-Han; Jiang, Jehn-Ruey; Tsai, Chung-Hsien; Wu, Zong-Syun

2017-01-01

This paper investigates how to efficiently charge sensor nodes in a wireless rechargeable sensor network (WRSN) with radio frequency (RF) chargers to make the network sustainable. An RF charger is assumed to be equipped with a uniform circular array (UCA) of 12 antennas with the radius λ, where λ is the RF wavelength. The UCA can steer most RF energy in a target direction to charge a specific WRSN node by the beamforming technology. Two evolutionary algorithms (EAs) using the evolution strategy (ES), namely the Evolutionary Beamforming Optimization (EBO) algorithm and the Evolutionary Beamforming Optimization Reseeding (EBO-R) algorithm, are proposed to nearly optimize the power ratio of the UCA beamforming peak side lobe (PSL) and the main lobe (ML) aimed at the given target direction. The proposed algorithms are simulated for performance evaluation and are compared with a related algorithm, called Particle Swarm Optimization Gravitational Search Algorithm-Explore (PSOGSA-Explore), to show their superiority. PMID:28825648

Chandra Observations of Extended X-Ray Emission in ARP 220

NASA Technical Reports Server (NTRS)

McDowell, J. C.; Clements, D. L.; Lamb, S. A.; Shaked, S.; Hearn, N. C.; Colina, L.; Mundell, C.; Borne, K.; Baker, A. C.; Arribas, S.

2003-01-01

We resolve the extended X-ray emission from the prototypical ultraluminous infrared galaxy Arp 220. Extended, faint, edge-brightened, soft X-ray lobes outside the optical galaxy are observed to a distance of 1CL 15 kpc on each side of the nuclear region. Bright plumes inside the optical isophotes coincide with the optical line emission and extend 1 1 kpc from end to end across the nucleus. The data for the plumes cannot be fitted by a single-temperature plasma and display a range of temperatures from 0.2 to 1 keV. The plumes emerge from bright, diffuse circumnuclear emission in the inner 3 kpc centered on the Ha peak, which is displaced from the radio nuclei. There is a close morphological correspondence between the Ha and soft X-ray emission on all spatial scales. We interpret the plumes as a starburst-driven superwind and discuss two interpretations of the emission from the lobes in the context of simulations of the merger dynamics of Arp 220.

Mesoscale Diffractive Photonics in Geosciences

NASA Astrophysics Data System (ADS)

Minin, I. V.; Minin, O. V.

2016-06-01

The scattered light by various dielectric particles in atmosphere give information about the type of molecules and particles and their location, which are important to definition of propagation limitations through atmospheric and space weather variations, crisis communications, etc. Although these investigations explain far field properties of disturbed radiations, the solution of the physical problem requires simulations of the interactions in near-field. It has been shown that strongly localized EM field near the surface of single dielectric particle may be form by non-spherical and non-symmetrical mesoscale particles both as in transmitting as in reflection mode. It was also shown that the main lobe is narrower in case of 3 cube chain than single cube in far field, but there are many side-scattering lobes. It was mentioned that unique advantages provided by mesoscale dielectric photonic crystal based particles with three spatial dimensions of arbitrary shape allow developing a new types of micro/nano-probes with subwavelength resolution for ultra compact spectrometer-free sensor for on board a spacecraft or a plane.

Apparatus and method for laser beam diagnosis

DOEpatents

Salmon, Jr., Joseph T.

1991-01-01

An apparatus and method is disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam.

Apparatus and method for laser beam diagnosis

DOEpatents

Salmon, J.T. Jr.

1991-08-27

An apparatus and method are disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam. 11 figures.

The Differential Contributions of Conceptual Representation Format and Language Structure to Levels of Semantic Abstraction Capacity.

PubMed

Gainotti, Guido

2017-06-01

This paper reviews some controversies concerning the original and revised versions of the 'hub-and-spoke' model of conceptual representations and their implication for abstraction capacity levels. The 'hub-and-spoke' model, which is based on data gathered in patients with semantic dementia (SD), is the most authoritative model of conceptual knowledge. Patterson et al.'s (Nature Reviews Neuroscience, 8(12), 976-987, 2007) classical version of this model maintained that conceptual representations are stored in a unitary 'amodal' format in the right and left anterior temporal lobes (ATLs), because in SD the semantic disorder cuts across modalities and categories. Several authors questioned the unitary nature of these representations. They showed that the semantic impairment is 'multi-modal'only in the advanced stages of SD, when atrophy affects the ATLs bilaterally, but that impariments can be modality-specific in lateralised (early) stages of the disease. In these cases, SD mainly affects lexical-semantic knowledge when atrophy predominates on the left side and pictorial representations when atrophy prevails on the right side. Some aspects of the model (i.e. the importance of spokes, the multimodal format of representations and the graded convergence of modalities within the ATLs), which had already been outlined by Rogers et al. (Psychological Review, 111(1), 205-235, 2004) in a computational model of SD, were strengthened by these results. The relevance of these theoretical problems and of empirical data concerning the neural substrate of concrete and abstract words is discussed critically. The conclusion of the review is that the highest levels of abstraction are due more to the structuring influence of language than to the format of representations.

Sedimentology of onshore tsunami deposits of the Indian Ocean tsunami, 2004 in the mangrove forest of the Curieuse Marine National Park, Seychelles

NASA Astrophysics Data System (ADS)

Nentwig, V.; Bahlburg, H.; Monthy, D.

2012-12-01

The Seychelles were severely affected by the December 26, 2004 tsunami in the Indian Ocean. Since the tsunami history of small islands often remains unclear due to a young historiography we conducted a study of onshore tsunami deposits on the Seychelles in order to understand the scale of impact of the 2004 Indian Ocean tsunami and potential predecessors. As part of this project we found and studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond bay on the east coast of Curieuse Island. The 2004 Indian Ocean tsunami caused a change of habitat due to sedimentation of an extended sand sheet in the mangrove forest. We present results of the first detailed sedimentological study of onshore tsunami deposits of the 2004 Indian Ocean tsunami conducted on the Seychelles. The Curieuse mangrove forest at Old Turtle Pond bay is part of the Curieuse Marine National Park. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The silt to fine sand sized and organic rich mangrove soil was subsequently covered by carbonate fine to medium sand (1.5 to 2.1 Φ) containing coarser carbonate shell debris which had been trapped outside the mangrove bay before the tsunami. The tsunami deposited a sand sheet which is organized into different lobes. They extend landwards to different inundation distances as a function of morphology. Maximum inundation distance is 200 m. The sediments often cover the pneumatophores of the mangroves. No landward fining trend of the sand sheet has been observed. On the different sand lobes carbonate-cemented sandstone debris ranging in size from 0.5 up to 12 cm occurs. Also numerous mostly fragmented shells of bivalves and molluscs were distributed on top of the sand lobes. Intact bivalve shells were mostly positioned with the convex side upwards. On small ledges of a granitic body at 120 m from the shore fragmented and complete shells were deposited at different elevations of up to 4 m. This implies a run up height of at least 4 m above sea level at this distance from the shore. Our study presents the mapping of the tsunamigenic sand lobes, their grain size distribution and petrographic variations of their components compared to the mangrove soil. The difference in the grain size and amount of organic material of the mangrove soil compared to the sand lobes indicate that the coarser material was entrained from outside of the mangrove forest by the tsunami. The similarity of the grain size distributions of the sediment of the sand lobes and of a reference beach/intertidal sample suggests the lagoon between the mangrove forest and the causeway as the probable sediment source area. The fact that the mangrove forest is surrounded by granitic hills and the appearance of the carbonate sandstone debris mostly on the surface of the sand sheets supports this assumption.

Debonding Stress Concentrations in a Pressurized Lobed Sandwich-Walled Generic Cryogenic Tank

NASA Technical Reports Server (NTRS)

Ko, William L.

2004-01-01

A finite-element stress analysis has been conducted on a lobed composite sandwich tank subjected to internal pressure and cryogenic cooling. The lobed geometry consists of two obtuse circular walls joined together with a common flat wall. Under internal pressure and cryogenic cooling, this type of lobed tank wall will experience open-mode (a process in which the honeycomb is stretched in the depth direction) and shear stress concentrations at the junctures where curved wall changes into flat wall (known as a curve-flat juncture). Open-mode and shear stress concentrations occur in the honeycomb core at the curve-flat junctures and could cause debonding failure. The levels of contributions from internal pressure and temperature loading to the open-mode and shear debonding failure are compared. The lobed fuel tank with honeycomb sandwich walls has been found to be a structurally unsound geometry because of very low debonding failure strengths. The debonding failure problem could be eliminated if the honeycomb core at the curve-flat juncture is replaced with a solid core.

Circadian locomotor rhythms in the cricket, Gryllodes sigillatus. II. Interactions between bilaterally paired circadian pacemakers.

PubMed

Ushirogawa, H; Abe, Y; Tomioka, K

1997-10-01

The optic lobe is essential for circadian locomotor rhythms in the cricket, Gryllodes sigillatus. We examined potential interactions between the bilaterally paired optic lobes in circadian rhythm generation. When one optic lobe was removed, the free-running period of the locomotor rhythm slightly but significantly lengthened. When exposed to light-dark cycles (LD) with 26 hr period, intact and sham operated animals were clearly entrained to the light cycle, but a large number of animals receiving unilateral optic nerve severance showed rhythm dissociation. In the dissociation, two rhythmic components appeared; one was readily entrained to the given LD and the other free-ran with a period shorter than 24 hr, and activity was expressed only when they were inphase. The period of the free-running component was significantly longer than that of the animals with a single blinded pacemaker kept in LD13:13, suggesting that the pacemaker on the intact side had some influence on the blinded pacemaker even in the dissociated state. The ratio of animals with rhythm dissociation was greater with the lower light intensity of the LD. The results suggest that the bilaterally distributed pacemakers are only weakly coupled to one another but strongly suppress the activity driven by the partner pacemaker during their subjective day. The strong suppression of activity would be advantageous to keep a stable nocturnality for this cricket living indoors.

A comparative quantitative analysis of magnetic susceptibility artifacts in echo planar and PROPELLER diffusion-weighted images

NASA Astrophysics Data System (ADS)

Cho, Jae-Hwan; Lee, Hae-Kag; Yang, Han-Joon; Lee, Gui-Won; Park, Yong-Soon; Chung, Woon-Kwan

2013-01-01

In this study, the authors investigated whether periodically-rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging (DWI) can remove magnetic susceptibility artifacts and compared apparent diffusion coefficient (ADC) values for PROPELLER DWI and the common echo planar (EP) DWI. Twenty patients that underwent brain MRI with a metal dental implant were selected. A 3.0T MR scanner was then used to obtain EP DWI, PROPELLER DWI, and corresponding apparent diffusion coefficient (ADC) maps for a b-value of 0 and 1,000 s/mm2. The frequencies of magnetic susceptibility artifacts in four parts of the brain (bilateral temporal lobes, pons, and orbit) were selected. In the ADC maps, we measured the ADC values of both sides of the temporal lobe and the pons. According to the study results, the frequency of magnetic susceptibility artifacts in PROPELLER DW images was lower than it was in EP DW images. In ADC maps, the ADC values of the bilateral temporal lobes and the pons were all higher in PROPELLER ADC maps than in EP ADC maps. Our findings show that when a high-field MRI machine is used, magnetic susceptibility artifacts can distort anatomical structures and produce high-intensity signals. Furthermore, our findings suggest that in many cases, PROPELLER DWI would be helpful in terms of achieving a correct diagnosis.

A new venous conduit utilizing the recipient portal vein branches for segment V in adult partial liver transplantation.

PubMed

Moon, I S; Kim, D G; Lee, M D; Hong, S K; Park, S C; Oh, D Y; Ahn, S T; Lee, Y J

2005-03-01

Right anterior-medial lobe congestion due to temporary clamping of segment V and/or VIII is common in the operative theater during adult donor right lobe liver transplantation, the most common procedure in our institute. We have used an autogenous saphenous vein conduit to recipient portal vein tributaries in 15 cases, as a "Y-to-I venoplasty" since January 2004. The recipient portal vein is transected 5 mm proximal to its bifurcation and extended to both sides with partial hepatic dissection. The "Y-to-I venoplasty" is made by suture closure of the portal vein transversely to form a tube. The average length is 7.5 cm with a 1.3 cm width. One end of "Y-to-I venoplasty" conduit is anastomosed to the donor segment V branch on the back table. And the other end is anastomosed directly to the IVC via a new window or the middle hepatic vein stump in recipient. The phase distension of the conduit with respiration is noted in the operative field. A 6/15 (40%) patency rate, was observed by CT angiography at the second postoperative week. All-patient conduits showed good flow on serial examinations at the 60th postoperative day. This new venous graft, made of recipient portal vein is a good conduit for segment V decongestion in adult right lobe partial liver transplantation.

Comparison of automated volumetry of the hippocampus using NeuroQuant® and visual assessment of the medial temporal lobe in Alzheimer's disease.

PubMed

Persson, Karin; Barca, Maria Lage; Cavallin, Lena; Brækhus, Anne; Knapskog, Anne-Brita; Selbæk, Geir; Engedal, Knut

2017-01-01

Background Different clinically feasible methods for evaluation of medial temporal lobe atrophy exists and are useful in diagnostic work-up of Alzheimer's disease (AD). Purpose To compare the diagnostic properties of two clinically available magnetic resonance imaging (MRI)-based methods-an automated volumetric software, NeuroQuant® (NQ) (evaluation of hippocampus volume) and the Scheltens scale (visual evaluation of medial temporal lobe atrophy [MTA])-in patients with AD dementia, and subjective and mild cognitive impairment (non-dementia). Material and Methods MRIs from 56 patients (31 AD, 25 non-dementia) were assessed with both methods. Correlations between the methods were calculated and receiver operating curve (ROC) analyses that yield area under the curve (AUC) statistics were conducted. Results High correlations were found between the two MRI assessments for the total hippocampal volume measured with NQ and mean MTA score (-0.753, P < 0.001), for the right (-0.767, P < 0.001), and for the left (-0.675, P < 0.001) sides. The NQ total measure yielded somewhat higher AUC (0.88, "good") compared to the MTA mean measure (0.80, "good") in the comparison of patients with AD and non-dementia, but the accuracy was in favor of the MTA scale. Conclusion The two methods correlated highly and both methods reached equally "good" power.

Prototapirella ciliates from wild habituated Virunga mountain gorillas (Gorilla beringei beringei) in Rwanda with the descriptions of two new species.

PubMed

Ito, Akira; Eckardt, Winnie; Stoinski, Tara S; Gillespie, Thomas R; Tokiwa, Toshihiro

2016-06-01

The morphology of Prototapirella fosseyi n. sp., P. rwanda n. sp. and P. gorillaeImai, Ikeda, Collet, and Bonhomme, 1991 in the Entodiniomorphida were described from the mountain gorillas, Gorilla beringei beringei, in Rwanda. The ciliates have a retractable adoral ciliary zone, four non-retractable ciliary tufts in four caudalia, and one broad skeletal plate beneath the body surface. P. rwanda has a dorsal lobe and ventral lobes in two rows whereas P. fosseyi has no lobes. These two new species have an elongated body, a flat tail flap leaning to the ventral, a macronucleus with a tapering anterior end, a round posterior end and a shallow depression on the dorsal side, a micronucleus lying near the anterior end of macronucleus, a thin left region of the skeletal plate, a distinct skeletal rod plate, and four contractile vacuoles. P. gorillae has some variations in the nuclei and the skeletal plate. The infraciliary bands of three Prototapirella species were the same as some Triplumaria species; a C-shaped adoral polybrachykinety, a slender perivestibular polybrachykinety, and paralabial kineties in their retractable adoral ciliary zone and short lateral polybrachykineties in their four caudalia. The perivestibular polybrachykinety is joined only to the right end of adoral polybrachykinety. Copyright © 2016 Elsevier GmbH. All rights reserved.

Efficacy and cognitive side effects of tiagabine and topiramate in patients with epilepsy.

PubMed

Fritz, N; Glogau, S; Hoffmann, J; Rademacher, M; Elger, C E; Helmstaedter, C

2005-05-01

Whereas the efficacy of the newer antiepileptic drugs (AEDs) is well established, there remain questions regarding their cognitive side effects. Therefore, we performed a comparative open randomized trial with TPM and TGB as add-on therapy, with particular consideration of cognition, mood, and health-related quality of life (HRQOL). Forty-one patients with refractory epilepsy were randomly assigned to one of the two treatment groups (TPM vs TGB) and received neuropsychological testing at baseline (T1), after titration (3 months, T2), and during the maintenance phase (another 3 months, T3). Tests included measures of intelligence, attention, working memory, episodic memory, language, and self-report questionnaires regarding mood and HRQOL. Twenty patients (8 TPM, 12 TGB) discontinued the trial for different reasons (no group difference). Seizure outcome (intention-to-treat analysis) was comparably good in both groups (8.1% seizure free, 29.7% seizure reduction>50%). From baseline to after the titration paired sample t tests revealed significant deterioration in verbal fluency, language comprehension, working memory, and visual block tapping under TPM and a deterioration in verbal memory (delayed free recall) in the TGB group. These functions remained stable in the maintenance phase. Self-report measures initially indicated concerns about AED side effects in both groups and concerns about worse cognitive functioning and depression under TPM. In the maintenance phase the TGB group reported feeling a lack of energy, whereas patients on TPM demonstrated improvement on all QOLIE scales on a descriptive level. This study demonstrates the comparable efficacy of TPM and TGB. Consistent with previous reports, TPM but not TGB appears to be associated with persistent negative cognitive side effects on frontal lobe-associated functions, the degree of which may be estimated by the fact that this effect was observed with a very small sample size. In contrast, in patients taking TPM, initially negatively affected HRQOL returns to baseline in the long run on a descriptive level. The latter finding may be interpreted in accordance with the observation that objective performance and subjective self-report under TPM can be dissociated.

Photoacoustic simulation study of chirp excitation response from different size absorbers

NASA Astrophysics Data System (ADS)

Jnawali, K.; Chinni, B.; Dogra, V.; Rao, N.

2017-03-01

Photoacoustic (PA) imaging is a hybrid imaging modality that integrates the strength of optical and ultrasound imaging. Nanosecond (ns) pulsed lasers used in current PA imaging systems are expensive, bulky and they often waste energy. We propose and evaluate, through simulations, the use of a continuous wave (CW) laser whose amplitude is linear frequency modulated (chirp) for PA imaging. The chirp signal provides signal-to-side-lobe ratio (SSR) improvement potential and full control over PA signal frequencies excited in the sample. The PA signal spectrum is a function of absorber size and the time frequencies present in the chirp. A mismatch between the input chirp spectrum and the output PA signal spectrum can affect the compressed pulse that is recovered from cross-correlating the two. We have quantitatively characterized this effect. The k-wave Matlab tool box was used to simulate PA signals in three dimensions for absorbers ranging in size from 0.1 mm to 0.6 mm, in response to laser excitation amplitude that is linearly swept from 0.5 MHz to 4 MHz. This sweep frequency range was chosen based on the spectrum analysis of a PA signal generated from ex-vivo human prostate tissue samples. In comparison, the energy wastage by a ns laser pulse was also estimated. For the chirp methodology, the compressed pulse peak amplitude, pulse width and side lobe structure parameters were extracted for different size absorbers. While the SSR increased 6 fold with absorber size, the pulse width decreased by 25%.

Neural correlates of conversion disorder: overview and meta-analysis of neuroimaging studies on motor conversion disorder.

PubMed

Boeckle, Markus; Liegl, Gregor; Jank, Robert; Pieh, Christoph

2016-06-10

Conversion Disorders (CD) are prevalent functional disorders. Although the pathogenesis is still not completely understood, an interaction of genetic, neurobiological, and psychosocial factors is quite likely. The aim of this study is to provide a systematic overview on imaging studies on CDs and investigate neuronal areas involved in Motor Conversion Disorders (MCD). A systematic literature search was conducted on CD. Subsequently a meta-analysis of functional neuroimaging studies on MCD was implemented using an Activation Likelihood Estimation (ALE). We calculated differences between patients and healthy controls as well as between affected versus unaffected sides in addition to an overall analysis in order to identify neuronal areas related to MCD. Patients with MCD differ from healthy controls in the amygdala, superior temporal lobe, retrosplenial area, primary motor cortex, insula, red nucleus, thalamus, anterior as well as dorsolateral prefrontal and frontal cortex. When comparing affected versus unaffected sides, temporal cortex, dorsal anterior cingulate cortex, supramarginal gyrus, dorsal temporal lobe, anterior insula, primary somatosensory cortex, superior frontal gyrus and anterior prefrontal as well as frontal cortex show significant differences. Neuronal areas seem to be involved in the pathogenesis, maintenance or as a result of MCD. Areas that are important for motor-planning, motor-selection or autonomic response seem to be especially relevant. Our results support the emotional unawareness theory but also underline the need of more support by conduction imaging studies on both CD and MCD.

Gelatinous fibers and variant secondary growth related to stem undulation and contraction in a monkey ladder vine, Bauhinia glabra (Fabaceae).

PubMed

Fisher, Jack B; Blanco, Mario A

2014-04-01

Some of the most striking stem shapes occur in species of Bauhinia (Fabaceae) known as monkey ladder vines. Their mature stems are flattened and develop regular undulations. Although stems have variant (anomalous) secondary growth, the mechanism causing the undulations is unknown. We measured stem segments over time (20 mo), described stem development using light microscopy, and correlated the changes in stem shape with anatomy. Growing stems are initially straight and bear tendrils on short axillary branches. The inner secondary xylem has narrow vessels and lignified fibers. As stems age, they become flattened and increasingly undulated with the production of two lobes of outer secondary xylem (OX) with wide vessels and only gelatinous fibers (G-fibers). Similar G-fibers are present in the secondary phloem and the cortical sclerified layer. In transverse sections, the concave side of each undulation has a greater area and quantity of G-fibers than the opposite convex side. Some older stems are not undulated and have less lobing of OX. Undulation causes a shortening of the stem segments: up to 28% of the original length. Uneven distribution of G-fibers produces tensions that are involved in the protracted development of undulations. While young extending shoots attach by lateral branch tendrils, older stems may maintain their position in the canopy using undulations and persistent branch bases as gripping devices. Flattened and undulated stems with G-fibers produce flexible woody stems.

Individual prediction of change in delayed recall of prose passages after left-sided anterior temporal lobectomy.

PubMed

Jokeit, H; Ebner, A; Holthausen, H; Markowitsch, H J; Moch, A; Pannek, H; Schulz, R; Tuxhorn, I

1997-08-01

Prognostic variables for individual memory outcome after left anterior temporal lobectomy (ATL) were studied in 27 patients with refractory temporal lobe epilepsy. The difference between pre- and postoperative performance in the delayed recall of two prose passages (Story A and B) from the Wechsler Memory Scale served as measure of postoperative memory change. Fifteen independent clinical, neuropsychological, and electrophysiological variables were submitted to a multiple linear regression analysis. Preoperative immediate and delayed recall of story content and right hemisphere Wada memory performance for pictorial and verbal items explained very well postoperative memory changes in recall of Story B. Delayed recall of Story B, but not of Story A, had high concurrent validity to other measures of memory. Patients who became seizure-free did not differ in memory change from patients who continued to have seizures after ATL. The variables age at epilepsy onset and probable age at temporal lobe damage provided complementary information for individual prediction but with less effectiveness than Wada test data. Our model confirmed that good preoperative memory functioning and impaired right hemispheric Wada memory performance for pictorial items predict a high risk of memory loss after left ATL. The analyses demonstrate that the combination of independent measures delivers more information than Wada test performance or any other variable alone. The suggested function can be used routinely to estimate the individual severity of verbal episodic memory impairment that might occur after left-sided ATL and offers a rational basis for the counseling of patients.

Towards the optimisation of acoustic fields for ablative therapies of tumours in the upper abdomen

NASA Astrophysics Data System (ADS)

Gélat, P.; ter Haar, G.; Saffari, N.

2013-08-01

The efficacy of high intensity focused ultrasound (HIFU) for the non-invasive treatment of cancer has been demonstrated for a range of different cancers including those of the liver, kidney, prostate and breast. As a non-invasive focused therapy, HIFU offers considerable advantages over other techniques such as chemotherapy and surgical resection, in terms of its non-invasiveness and low risk of harmful side effects. There is, however, a number of significant challenges which currently hinder its widespread clinical application. One of these challenges is the need to transmit sufficient energy through the ribcage to induce tissue necrosis at the required foci whilst minimising the formation of side lobes and sparing healthy tissue. Ribs both absorb and reflect ultrasound strongly. As such, a common side effect of focusing ultrasound in regions located behind the rib cage is the overheating of bone and surrounding tissue, which can lead to skin burns. Successful treatment of a patient with tumours in the upper abdomen therefore requires a thorough understanding of the way acoustic and thermal energy are deposited. This is likely to rely on a treatment planning procedure in which optimal source velocity distributions are obtained so as to maximise a dose quantity at the treatment sites, whilst ensuring that this quantity does not exceed a specified threshold at other field locations, particularly on the surface of the ribs. Previously, a boundary element approach based on a Generalised Minimal Residual (GMRES) implementation of the Burton-Miller formulation was developed to predict the field of a multi-element HIFU array scattered by human ribs, the topology of which was obtained from CT scan data [1]. This work describes the reformulation of the boundary element equations as a least-squares minimisation problem with non-linear constraints. The methodology was subsequently tested at an excitation frequency of 100 kHz on a spherical multi-element array in the presence of a perfectly rigid cylindrical scatterer with hemi-spherical end-caps. Reduction of side lobes in the exterior domain and of acoustic pressure magnitudes on the surface of the cylinder were achieved whilst preserving a local maximum in the focal region.

Activations in temporal areas using visual and auditory naming stimuli: A language fMRI study in temporal lobe epilepsy.

PubMed

Gonzálvez, Gloria G; Trimmel, Karin; Haag, Anja; van Graan, Louis A; Koepp, Matthias J; Thompson, Pamela J; Duncan, John S

2016-12-01

Verbal fluency functional MRI (fMRI) is used for predicting language deficits after anterior temporal lobe resection (ATLR) for temporal lobe epilepsy (TLE), but primarily engages frontal lobe areas. In this observational study we investigated fMRI paradigms using visual and auditory stimuli, which predominately involve language areas resected during ATLR. Twenty-three controls and 33 patients (20 left (LTLE), 13 right (RTLE)) were assessed using three fMRI paradigms: verbal fluency, auditory naming with a contrast of auditory reversed speech; picture naming with a contrast of scrambled pictures and blurred faces. Group analysis showed bilateral temporal activations for auditory naming and picture naming. Correcting for auditory and visual input (by subtracting activations resulting from auditory reversed speech and blurred pictures/scrambled faces respectively) resulted in left-lateralised activations for patients and controls, which was more pronounced for LTLE compared to RTLE patients. Individual subject activations at a threshold of T>2.5, extent >10 voxels, showed that verbal fluency activated predominantly the left inferior frontal gyrus (IFG) in 90% of LTLE, 92% of RTLE, and 65% of controls, compared to right IFG activations in only 15% of LTLE and RTLE and 26% of controls. Middle temporal (MTG) or superior temporal gyrus (STG) activations were seen on the left in 30% of LTLE, 23% of RTLE, and 52% of controls, and on the right in 15% of LTLE, 15% of RTLE, and 35% of controls. Auditory naming activated temporal areas more frequently than did verbal fluency (LTLE: 93%/73%; RTLE: 92%/58%; controls: 82%/70% (left/right)). Controlling for auditory input resulted in predominantly left-sided temporal activations. Picture naming resulted in temporal lobe activations less frequently than did auditory naming (LTLE 65%/55%; RTLE 53%/46%; controls 52%/35% (left/right)). Controlling for visual input had left-lateralising effects. Auditory and picture naming activated temporal lobe structures, which are resected during ATLR, more frequently than did verbal fluency. Controlling for auditory and visual input resulted in more left-lateralised activations. We hypothesise that these paradigms may be more predictive of postoperative language decline than verbal fluency fMRI. Copyright © 2016 Elsevier B.V. All rights reserved.

Long term outcome of temporal lobe epilepsy surgery: analyses of 140 consecutive patients

PubMed Central

Jutila, L; Immonen, A; Mervaala, E; Partanen, J; Partanen, K; Puranen, M; Kalviainen, R; Alafuzoff, I; Hurskainen, H; Vapalahti, M; Ylinen, A

2002-01-01

Objective: To analyse the long term results of temporal lobe epilepsy surgery in a national epilepsy surgery centre for adults, and to evaluate preoperative factors predicting a good postoperative outcome on long term follow up. Methods: Longitudinal follow up of 140 consecutive adult patients operated on for drug resistant temporal lobe epilepsy. Results: 46% of patients with unilateral temporal lobe epilepsy became seizure-free, 10% had only postoperative auras, and 15% had rare seizures on follow up for (mean (SD)) 5.4 (2.6) years, range 0.25 to 10.5 years. The best outcome was after introduction of a standardised magnetic resonance (MR) imaging protocol (1993–99): in unilateral temporal lobe epilepsy, 52% of patients became seizure-free, 7% had only postoperative auras, and 17% had rare seizures (median follow up 3.8 years, range 0.25 to 6.5 years); in palliative cases (incomplete removal of focus), a reduction in seizures of at least 80% was achieved in 71% of cases (median follow up 3.1 years, range 1.1 to 6.8 years). Most seizure relapses (86%) occurred within one year of the operation, and outcome at one year did not differ from the long term outcome. Unilateral hippocampal atrophy with or without temporal cortical atrophy on qualitative MR imaging (p < 0.001, odds ratio (OR) 5.2, 95% confidence interval (CI) 2.0 to 13.7), other unitemporal structural lesions on qualitative MR imaging (p ≤ 0.001, OR 6.9, 95% CI 2.2 to 21.5), onset of epilepsy before the age of five years (p < 0.05, OR 2.9, 95% CI 1.2 to 7.2), and focal seizures with ictal impairment of consciousness and focal ictal EEG as a predominant seizure type (p < 0.05, OR 3.4, 95% CI 1.2 to 9.1) predicted Engel I–II outcome. Hippocampal volume reduction of at least 1 SD from the mean of controls on the side of the seizure onset (p < 0.05, OR 3.1, 95% CI 1.1 to 9.2) also predicted Engel I–II outcome. Conclusions: Outcome at one year postoperatively is highly predictive of long term outcome after temporal lobe epilepsy surgery. Unitemporal MR imaging abnormalities, early onset of epilepsy, and seizure type predominance are factors associated with good postoperative outcome. PMID:12397139

Size-frequency distribution of boulders ≥7 m on comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Pajola, Maurizio; Vincent, Jean-Baptiste; Güttler, Carsten; Lee, Jui-Chi; Bertini, Ivano; Massironi, Matteo; Simioni, Emanuele; Marzari, Francesco; Giacomini, Lorenza; Lucchetti, Alice; Barbieri, Cesare; Cremonese, Gabriele; Naletto, Giampiero; Pommerol, Antoine; El-Maarry, Mohamed R.; Besse, Sébastien; Küppers, Michael; La Forgia, Fiorangela; Lazzarin, Monica; Thomas, Nicholas; Auger, Anne-Thérèse; Sierks, Holger; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst U.; Agarwal, Jessica; A'Hearn, Michael F.; Barucci, Maria A.; Bertaux, Jean-Loup; Da Deppo, Vania; Davidsson, Björn; De Cecco, Mariolino; Debei, Stefano; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Groussin, Olivier; Gutierrez, Pedro J.; Hviid, Stubbe F.; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kramm, J.-Rainer; Kürt, Ekkehard; Lara, Luisa M.; Lin, Zhong-Yi; Lopez Moreno, Jose J.; Magrin, Sara; Marchi, Simone; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Oklay, Nilda; Preusker, Frank; Scholten, Frank; Tubiana, Cecilia

2015-11-01

Aims: We derive for the first time the size-frequency distribution of boulders on a comet, 67P/Churyumov-Gerasimenko (67P), computed from the images taken by the Rosetta/OSIRIS imaging system. We highlight the possible physical processes that lead to these boulder size distributions. Methods: We used images acquired by the OSIRIS Narrow Angle Camera, NAC, on 5 and 6 August 2014. The scale of these images (2.44-2.03 m/px) is such that boulders ≥7 m can be identified and manually extracted from the datasets with the software ArcGIS. We derived both global and localized size-frequency distributions. The three-pixel sampling detection, coupled with the favorable shadowing of the surface (observation phase angle ranging from 48° to 53°), enables unequivocally detecting boulders scattered all over the illuminated side of 67P. Results: We identify 3546 boulders larger than 7 m on the imaged surface (36.4 km2), with a global number density of nearly 100/km2 and a cumulative size-frequency distribution represented by a power-law with index of -3.6 +0.2/-0.3. The two lobes of 67P appear to have slightly different distributions, with an index of -3.5 +0.2/-0.3 for the main lobe (body) and -4.0 +0.3/-0.2 for the small lobe (head). The steeper distribution of the small lobe might be due to a more pervasive fracturing. The difference of the distribution for the connecting region (neck) is much more significant, with an index value of -2.2 +0.2/-0.2. We propose that the boulder field located in the neck area is the result of blocks falling from the contiguous Hathor cliff. The lower slope of the size-frequency distribution we see today in the neck area might be due to the concurrent processes acting on the smallest boulders, such as i) disintegration or fragmentation and vanishing through sublimation; ii) uplifting by gas drag and consequent redistribution; and iii) burial beneath a debris blanket. We also derived the cumulative size-frequency distribution per km2 of localized areas on 67P. By comparing the cumulative size-frequency distributions of similar geomorphological settings, we derived similar power-law index values. This suggests that despite the selected locations on different and often opposite sides of the comet, similar sublimation or activity processes, pit formation or collapses, as well as thermal stresses or fracturing events occurred on multiple areas of the comet, shaping its surface into the appearance we see today.

[A case of brain metastasis discovered after surgery for lung cancer based on changes in CEA, in which long-term survival was obtained by repeated gammaknife irradiation].

PubMed

Kakeya, Hiroshi; Inoue, Yuichi; Sawai, Toyomitsu; Ikuta, Yasushi; Ohno, Hideaki; Yanagihara, Katsunori; Higashiyama, Yasuhito; Miyazaki, Yoshitsugu; Soda, Hiroshi; Tashiro, Takayoshi; Kohno, Shigeru

2005-12-01

A 58-year-old man underwent right lower lobectomy for lung adenocarcinoma in June 1998. Since a high level of tumor marker CEA persisted after surgery, chemotherapy was additionally performed, and the CEA level subsequently normalized. However, the CEA level increased in April 1999, and brain metastasis was found in the left occipital lobe, and the first gammaknife irradiation was performed. Multiple brain metastases were found when CEA increased again in August 1999, and the second gammaknife irradiation was performed. Moreover, brain metastases were found in the left frontal and occipital lobes in February 2000, and the third gammaknife irradiation was performed. CEA normalized thereafter, but increased in February 2001. Brain metastasis was found in the right occipital lobe, and the fourth gammaknife irradiation was performed. CEA has remained within the normal range for about 4 years thereafter. Long-term survival was possible by repeated gammaknife irradiation for brain metastases. Monitoring of CEA played an important role in finding recurrent brain metastasis in this patient.

Left inferior parietal lobe engagement in social cognition and language

PubMed Central

Bzdok, Danilo; Hartwigsen, Gesa; Reid, Andrew; Laird, Angela R.; Fox, Peter T.; Eickhoff, Simon B.

2017-01-01

Social cognition and language are two core features of the human species. Despite distributed recruitment of brain regions in each mental capacity, the left parietal lobe (LPL) represents a zone of topographical convergence. The present study quantitatively summarizes hundreds of neuroimaging studies on social cognition and language. Using connectivity-based parcellation on a meta-analytically defined volume of interest (VOI), regional coactivation patterns within this VOI allowed identifying distinct subregions. Across parcellation solutions, two clusters emerged consistently in rostro-ventral and caudo-ventral aspects of the parietal VOI. Both clusters were functionally significantly associated with social-cognitive and language processing. In particular, the rostro-ventral cluster was associated with lower-level processing facets, while the caudo-ventral cluster was associated with higher-level processing facets in both mental capacities. Contrarily, in the (less stable) dorsal parietal VOI, all clusters reflected computation of general-purpose processes, such as working memory and matching tasks, that are frequently co-recruited by social or language processes. Our results hence favour a rostro-caudal distinction of lower-versus higher-level processes underlying social cognition and language in the left inferior parietal lobe. PMID:27241201

[Effects of temporal lobe epilepsy and idiopathic epilepsy on cognitive function and emotion in children].

PubMed

Yang, Xiao-Yan; Long, Li-Li; Xiao, Bo

2016-07-01

To investigate the effects of temporal lobe epilepsy and idiopathic epilepsy on cognitive function and emotion in children and the risk factors for cognitive impairment. A retrospective analysis was performed for the clinical data of 38 children with temporal lobe epilepsy and 40 children with idiopathic epilepsy. The controls were 42 healthy children. All subjects received the following neuropsychological tests: Montreal Cognitive Assessment (MoCA) scale, verbal fluency test, digit span test, block design test, Social Anxiety Scale for Children (SASC), and Depression Self-rating Scale for Children (DSRSC). Compared with the control group, the temporal lobe epilepsy and idiopathic epilepsy groups showed significantly lower scores of MoCA, verbal fluency, digit span, and block design (P<0.05) and significantly higher scores on SASC and DSRSC (P<0.05). Compared with the idiopathic epilepsy group, the temporal lobe epilepsy group showed significantly lower scores of MoCA, verbal fluency, digit span, and block design (P<0.05) and significantly higher scores on SASC and DSRSC (P<0.05). In the temporal lobe epilepsy group, MoCA score was negatively correlated with SASC score, DSRSC score, and seizure frequency (r=-0.571, -0.529, and -0.545 respectively; P<0.01). In the idiopathic epilepsy group, MoCA score was also negatively correlated with SASC score, DSRSC score, and seizure frequency (r=-0.542, -0.487, and -0.555 respectively; P<0.01). Children with temporal lobe epilepsy and idiopathic epilepsy show impaired whole cognition, verbal fluency, memory, and executive function and have anxiety and depression, which are more significant in children with temporal lobe epilepsy. High levels of anxiety, depression, and seizure frequency are risk factors for impaired cognitive function.

Seismic geomorphology of the Lobed-channel System of Upper Miocene Huangliu Formation, Yinggehai Basin, Northwestern South China Sea

NASA Astrophysics Data System (ADS)

Liu, H.

2016-02-01

Three-dimensional seismic data have been widely used in interpreting ancient river systems and their associated sediment deposits. Thin-bed reservoirs of lobed-channel system in lithostratigraphic units of Dongfang (DF) area are one of the major study areas for reservoir growth in the Yinggehai basin of northwestern South China Sea. Although it is understood that the transport mechanics of parent substrate and alluvium determine the morphology of channel for lobed-channel system, the transport mechanism and regional gradient are relatively poorly understood. This study is focused on the application of various techniques in seismic geomorphology to the Yinggehai Basin at paleo-water-depth of 120m to assess influences of regional gradient and relative sea level change on lobed-channel palaeogeomorphology in shallow-water environments. The Vietnam paleo-Blue River, which located at south of modern Red River, flowed through DF area and transported turbidity deposit to DF area in the coastal environment. In 3-D seismic survey area, four fifth-order sequences in first member of upper Miocene Huangliu formation were identified using well and seismic data. Seismic inversion and 90° phasing of seismic data were used to convert seismic traces to pseudolithologic logs. Stratal slicing made it possible to interpolate and extrapolate well-data-derived sequence and identify submarine fan, channel fill, lobes and overbank deposit. Strata slices suggested that sea-floor slopes exerted main influence on channel morphology. Specifically, DF13-1 block had high gradient, which mainly distributed mud-sand-rich lobes. However, DF13-2 block established low gradient, which mostly indicated sand-rich braided channels. The values of sinuosity, channel widths, meander-belt widths in DF13-2 block are all greater than these in DF13-1 block. In addition, results of carbon isotope measurements and foraminiferal research of two blocks suggest that paleo sea level in DF13-2 block (30m 150m) was higher than that of DF13-1 block (20m 90m). It also deciphered why channels in DF13-2 incised deeply because of the stronger hydrodynamic energy in the shallow-water environments. Thus DF13-2 block was formed in a lobed-channel and sand rich system, compared with DF13-1 of channelized-lobes and mud-sand rich system.

The side of chronic low back pain matters: evidence from the primary motor cortex excitability and the postural adjustments of multifidi muscles.

PubMed

Massé-Alarie, Hugo; Beaulieu, Louis-David; Preuss, Richard; Schneider, Cyril

2017-03-01

Hemispheric lateralization of pain processing was reported with overactivation of the right frontal lobe. Specifically in chronic low back pain (CLBP), functional changes in the left primary motor cortex (M1) with impaired anticipatory postural activation (APA) of trunk muscles have been observed. Given the connections between frontal and M1 areas for motor planning, it is hypothesized that the pain side could differently influence M1 function and APA of paravertebral multifidus (MF) muscles. This study aimed at testing whether people with right- versus left-sided CLBP showed different M1 excitability and APA. Thirty-five individuals with lateralized CLBP (19 right-sided and 16 left-sided) and 13 pain-free subjects (normative values) were tested for the excitability of MF M1 area (active motor threshold-AMT) with transcranial magnetic stimulation and for the latency of MF APA during bilateral shoulder flexion and during unilateral hip extension in prone lying. In the right-sided CLBP group, the AMT of both M1 areas was lower than in the left-sided group and the pain-free subjects; the latency of MF APA was shorter in bilateral shoulder flexion and in the left hip extension tasks as compared to the left-sided group. In CLBP, an earlier MF APA was correlated with lower AMT in both tasks. People with right-sided CLBP presented with increased M1 excitability in both hemispheres and earlier MF APA. These results likely rely on cortical motor adaptation related to the tasks and axial muscles tested. Future studies should investigate whether CLBP side-related differences have a clinical impact, e.g. in diagnosis and intervention.

Intracranial toxoplasmosis presenting as panhypopituitarism in an immunocompromised patient.

PubMed

Hamdeh, Shadi; Abbas, Anum; Fraker, Jessica; Lambrecht, J E

2015-12-01

A 37-year-old man presented with worsening headache, vomiting, and right-sided weakness over the last few weeks. A head computed tomography showed a left hemispheric posterior medial parietal lobe lesion with surrounding edema. Further imaging with magnetic resonance imaging showed multiple enhancing mass lesions. The largest lesion measured 2.4 cm within the left occipital parietal region (Figure A and B). Laboratory data showed reactive HIV antibodies, confirmed by Western blot. An absolute CD4 count was 22 cells/μL. Other laboratory test results showed low sodium, thyrotropin, FT4, FT3, cortisol levels, corticotropin, luteinizing hormone, and testosterone. Based on these findings, the brain lesions were believed to be causing his panhypopituitarism. A brain biopsy confirmed the presence of Toxoplasma gondii by polymerase chain reaction. The patient was started on pyrimethamine and clindamycin for toxoplasmosis treatment, and azithromycin and sulfamethoxazole/trimethoprime for appropriate prophylaxis. He was also started on hormone supplementation. His symptoms were completely resolved at the time of discharge.

A new functional method to choose the target lobe for lung volume reduction in emphysema - comparison with the conventional densitometric method.

PubMed

Hetzel, Juergen; Boeckeler, Michael; Horger, Marius; Ehab, Ahmed; Kloth, Christopher; Wagner, Robert; Freitag, Lutz; Slebos, Dirk-Jan; Lewis, Richard Alexander; Haentschel, Maik

2017-01-01

Lung volume reduction (LVR) improves breathing mechanics by reducing hyperinflation. Lobar selection usually focuses on choosing the most destroyed emphysematous lobes as seen on an inspiratory CT scan. However, it has never been shown to what extent these densitometric CT parameters predict the least deflation of an individual lobe during expiration. The addition of expiratory CT analysis allows measurement of the extent of lobar air trapping and could therefore provide additional functional information for choice of potential treatment targets. To determine lobar vital capacity/lobar total capacity (LVC/LTC) as a functional parameter for lobar air trapping using on an inspiratory and expiratory CT scan. To compare lobar selection by LVC/LTC with the established morphological CT density parameters. 36 patients referred for endoscopic LVR were studied. LVC/LTC, defined as delta volume over maximum volume of a lobe, was calculated using inspiratory and expiratory CT scans. The CT morphological parameters of mean lung density (MLD), low attenuation volume (LAV), and 15th percentile of Hounsfield units (15%P) were determined on an inspiratory CT scan for each lobe. We compared and correlated LVC/LTC with MLD, LAV, and 15%P. There was a weak correlation between the functional parameter LVC/LTC and all inspiratory densitometric parameters. Target lobe selection using lowest lobar deflation (lowest LVC/LTC) correlated with target lobe selection based on lowest MLD in 18 patients (50.0%), with the highest LAV in 13 patients (36.1%), and with the lowest 15%P in 12 patients (33.3%). CT-based measurement of deflation (LVC/LTC) as a functional parameter correlates weakly with all densitometric CT parameters on a lobar level. Therefore, morphological criteria based on inspiratory CT densitometry partially reflect the deflation of particular lung lobes, and may be of limited value as a sole predictor for target lobe selection in LVR.

A multilevel-ROI-features-based machine learning method for detection of morphometric biomarkers in Parkinson's disease.

PubMed

Peng, Bo; Wang, Suhong; Zhou, Zhiyong; Liu, Yan; Tong, Baotong; Zhang, Tao; Dai, Yakang

2017-06-09

Machine learning methods have been widely used in recent years for detection of neuroimaging biomarkers in regions of interest (ROIs) and assisting diagnosis of neurodegenerative diseases. The innovation of this study is to use multilevel-ROI-features-based machine learning method to detect sensitive morphometric biomarkers in Parkinson's disease (PD). Specifically, the low-level ROI features (gray matter volume, cortical thickness, etc.) and high-level correlative features (connectivity between ROIs) are integrated to construct the multilevel ROI features. Filter- and wrapper- based feature selection method and multi-kernel support vector machine (SVM) are used in the classification algorithm. T1-weighted brain magnetic resonance (MR) images of 69 PD patients and 103 normal controls from the Parkinson's Progression Markers Initiative (PPMI) dataset are included in the study. The machine learning method performs well in classification between PD patients and normal controls with an accuracy of 85.78%, a specificity of 87.79%, and a sensitivity of 87.64%. The most sensitive biomarkers between PD patients and normal controls are mainly distributed in frontal lobe, parental lobe, limbic lobe, temporal lobe, and central region. The classification performance of our method with multilevel ROI features is significantly improved comparing with other classification methods using single-level features. The proposed method shows promising identification ability for detecting morphometric biomarkers in PD, thus confirming the potentiality of our method in assisting diagnosis of the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Electric potential of the moon in the magnetosheath and in the geomagnetic tail

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

Moskalenko, A.M.

1995-03-01

A layer of charged particles near the lunar surface is investigated. It is shown that in the magnetosheath and in the tail lobes, where secondary electronic emission of lunar soil in the plasma sheet is low, the electrostatic potential as a function of the height over the subsolar region of the surface is nonmonotone. As the terminator is approached, the potential becomes a negative monotone function. For most temperatures of the primary electrons that exist in the plasma sheet, secondary electron emission is high. In the case of high secondary electron emission, the electric potential is nonmonotone, and the variationmore » of the potential in the double layer is determined by the secondary electron emission and varies weakly in the passage from the dark side to the bright side.« less

The anterior temporal artery: an underutilized but robust donor for revascularization of the distal middle cerebral artery.

PubMed

Tayebi Meybodi, Ali; Lawton, Michael T; Griswold, Dylan; Mokhtari, Pooneh; Payman, Andre; Benet, Arnau

2017-10-01

OBJECTIVE The anterior temporal artery (ATA) supplies an area of the brain that, if sacrificed, does not cause a noticeable loss of function. Therefore, the ATA may be used as a donor in intracranial-intracranial (IC-IC) bypass procedures. The capacities of the ATA as a donor have not been studied previously. In this study, the authors assessed the feasibility of using the ATA as a donor for revascularization of different segments of the distal middle cerebral artery (MCA). METHODS The ATA was studied in 15 cadaveric specimens (8 heads, excluding 1 side). First, the cisternal segment of the artery was untethered from arachnoid adhesions and small branches feeding the anterior temporal lobe and insular cortex, to evaluate its capacity for a side-to-side bypass to insular, opercular, and cortical segments of the MCA. Any branch entering the anterior perforated substance was preserved. Then, the ATA was cut at the opercular-cortical junction and the capacity for an end-to-side bypass was assessed. RESULTS From a total of 17 ATAs, 4 (23.5%) arose as an early MCA branch. The anterior insular zone and the frontal parasylvian cortical arteries were the best targets (in terms of mobility and caliber match) for a side-to-side bypass. Most of the insula was accessible for end-to-side bypass, but anterior zones of the insula were more accessible than posterior zones. End-to-side bypass was feasible for most recipient cortical arteries along the opercula, except for posterior temporal and parietal regions. Early ATAs reached significantly farther on the insular MCA recipients than non-early ATAs for both side-to-side and end-to-side bypasses. CONCLUSIONS The ATA is a robust arterial donor for IC-IC bypass procedures, including side-to-side and end-to-side techniques. The evidence provided in this work supports the use of the ATA as a donor for distal MCA revascularization in well-selected patients.

Frontal lobe dysfunction in long-term cannabis users.

PubMed

Lundqvist, T; Jönsson, S; Warkentin, S

2001-01-01

This study examined the neurophysiological effects of cannabis. Cerebral blood flow (CBF) was measured in 12 long-term cannabis users shortly after cessation of cannabis use (mean 1.6 days). The findings showed significantly lower mean hemispheric blood flow values and significantly lower frontal values in the cannabis subjects compared to normal controls. The results suggest that the functional level of the frontal lobes is affected by long-term cannabis use.

The medial temporal lobe-conduit of parallel connectivity: a model for attention, memory, and perception.

PubMed

Mozaffari, Brian

2014-01-01

Based on the notion that the brain is equipped with a hierarchical organization, which embodies environmental contingencies across many time scales, this paper suggests that the medial temporal lobe (MTL)-located deep in the hierarchy-serves as a bridge connecting supra- to infra-MTL levels. Bridging the upper and lower regions of the hierarchy provides a parallel architecture that optimizes information flow between upper and lower regions to aid attention, encoding, and processing of quick complex visual phenomenon. Bypassing intermediate hierarchy levels, information conveyed through the MTL "bridge" allows upper levels to make educated predictions about the prevailing context and accordingly select lower representations to increase the efficiency of predictive coding throughout the hierarchy. This selection or activation/deactivation is associated with endogenous attention. In the event that these "bridge" predictions are inaccurate, this architecture enables the rapid encoding of novel contingencies. A review of hierarchical models in relation to memory is provided along with a new theory, Medial-temporal-lobe Conduit for Parallel Connectivity (MCPC). In this scheme, consolidation is considered as a secondary process, occurring after a MTL-bridged connection, which eventually allows upper and lower levels to access each other directly. With repeated reactivations, as contingencies become consolidated, less MTL activity is predicted. Finally, MTL bridging may aid processing transient but structured perceptual events, by allowing communication between upper and lower levels without calling on intermediate levels of representation.

Study of Far—Field Directivity Pattern for Linear Arrays

NASA Astrophysics Data System (ADS)

Ana-Maria, Chiselev; Luminita, Moraru; Laura, Onose

2011-10-01

A model to calculate directivity pattern in far field is developed in this paper. Based on this model, the three-dimensional beam pattern is introduced and analyzed in order to investigate geometric parameters of linear arrays and their influences on the directivity pattern. Simulations in azimuthal plane are made to highlight the influence of transducers parameters, including number of elements and inter-element spacing. It is true that these parameters are important factors that influence the directivity pattern and the appearance of side-lobes for linear arrays.

Communication satellite technology: State of the art and development opportunities

NASA Technical Reports Server (NTRS)

Woodford, J. B. (Compiler)

1978-01-01

Opportunities in communication satellite technology are identified and defined. Factors that tend to limit the ready availability of satellite communication to an increasingly wide group of users are evaluated. Current primary limitations on this wide utilization are the availability of frequency and/or synchronous equatorial satellite positions and the cost of individual user Earth terminals. The former could be ameliorated through the reuse of frequencies, the use of higher frequency bands, and the reduction of antenna side lobes. The latter limitation requires innovative hardware, design, careful system design, and large scale production.

The frequency hopping pattern design for random hopping frequency signal based on stationary phase principle

NASA Astrophysics Data System (ADS)

Liao, Zhikun; Lu, Dawei; Hu, Jiemin; Zhang, Jun

2018-04-01

For the random hopping frequency signal, the modulated frequencies are randomly distributed over given bandwidth. The randomness of modulated frequency not only improves the electronic counter countermeasure capability for radar systems, but also determines its performance of range compression. In this paper, the range ambiguity function of RHF signal is firstly derived. Then, a design method of frequency hopping pattern based on stationary phase principle to improve the peak to side-lobe ratio is proposed. Finally, the simulated experiments show a good effectiveness of the presented design method.

Decline in word-finding: The objective cognitive finding most relevant to patients after mesial temporal lobe epilepsy surgery.

PubMed

Pauli, Carla; de Oliveira Thais, Maria Emilia Rodrigues; Guarnieri, Ricardo; Schwarzbold, Marcelo Liborio; Diaz, Alexandre Paim; Ben, Juliana; Linhares, Marcelo Neves; Markowitsch, Hans Joachim; Wolf, Peter; Wiebe, Samuel; Lin, Katia; Walz, Roger

2017-10-01

The purpose of this study was to investigate the following: i) the objective impairment in neuropsychological tests that were associated with the subjective perception of cognitive function decline in Brazilian patients who underwent mesial temporal lobe epilepsy (MTLE) surgery and ii) the predictive variables for those impaired objective neuropsychological tests. Forty-eight adults with MTLE (27 right HS and 23 male) were divided according to their perception of changes (Decline or No-decline) of cognitive function domain of the QOLIE-31 questionnaire applied before and 1year after the ATL. The mean (SD) of changes in the raw score difference of the neuropsychological tests before and after the ATL was compared between Decline and No-decline groups. Receiver Operating Characteristic curves, sensitivity, specificity, and predictive values were used to assess the optimum cutoff points of neuropsychological test score changes to predict patient-reported subjective cognitive decline. Six (12.5%) patients reported a perception of cognitive function decline after ATL. Among the 25 cognitive tests analyzed, only changes in the Boston Naming Test (BNT) were associated with subjective cognitive decline reported by patients. A reduction of ≥8 points in the raw score of BNT after surgery had 91% of sensitivity and 45% specificity for predicting subjective perception of cognitive function decline by the patient. Left side surgery and age older than 40years were more associated with an important BNT reduction with overall accuracy of 91.7%, 95% predictive ability for no impairment, and 75% for impairment of cognitive function. Impairment in word-finding seems to be the objective cognitive finding most relevant to Brazilian patients after mesial temporal lobe epilepsy surgery. Similar to American patients, the side of surgery and age are good predictors for no decline in the BNT, but shows a lower accuracy to predict its decline. If replicated in other populations, the results may have wider implications for the surgical management of patients with drug-resistant MTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular isomerization induced by ultrashort infrared pulses. I. Few-cycle to sub-one-cycle Gaussian pulses and the role of the carrier-envelope phase.

PubMed

Uiberacker, Christoph; Jakubetz, Werner

2004-06-22

Using 550 previously calculated vibrational energy levels and dipole moments we performed simulations of the HCN-->HNC isomerization dynamics induced by sub-one-cycle and few-cycle IR pulses, which we represent as Gaussian pulses with 0.25-2 optical cycles in the pulse width. Starting from vibrationally pre-excited states, isomerization probabilities of up to 50% are obtained for optimized pulses. With decreasing number of optical cycles a strong dependence on the carrier-envelope phase (CEP) emerges. Although the optimized pulse parameters change significantly with the number of optical cycles, the distortion by the Gaussian envelope produces nearly equal fields, with a positive lobe followed by a negative one. The positions and areas of the lobes are also almost unchanged, irrespective of the number of cycles in the half-width. Isomerization proceeds via a pump-dumplike mechanism induced by the sequential lobes. The first lobe prepares a wave packet incorporating many delocalized states above the barrier. It is the motion of this wave packet across the barrier, which determines the timing of the pump and dump lobes. The role of the pulse parameters, and in particular of the CEP, is to produce the correct lobe sequence, size and timing within a continuous pulse. (c) 2004 American Institute of Physics.

The effect of applied transducer force on acoustic radiation force impulse quantification within the left lobe of the liver.

PubMed

Porra, Luke; Swan, Hans; Ho, Chien

2015-08-01

Introduction: Acoustic Radiation Force Impulse (ARFI) Quantification measures shear wave velocities (SWVs) within the liver. It is a reliable method for predicting the severity of liver fibrosis and has the potential to assess fibrosis in any part of the liver, but previous research has found ARFI quantification in the right lobe more accurate than in the left lobe. A lack of standardised applied transducer force when performing ARFI quantification in the left lobe of the liver may account for some of this inaccuracy. The research hypothesis of this present study predicted that an increase in applied transducer force would result in an increase in SWVs measured. Methods: ARFI quantification within the left lobe of the liver was performed within a group of healthy volunteers (n = 28). During each examination, each participant was subjected to ARFI quantification at six different levels of transducer force applied to the epigastric abdominal wall. Results: A repeated measures ANOVA test showed that ARFI quantification was significantly affected by applied transducer force (p = 0.002). Significant pairwise comparisons using Bonferroni correction for multiple comparisons showed that with an increase in applied transducer force, there was a decrease in SWVs. Conclusion: Applied transducer force has a significant effect on SWVs within the left lobe of the liver and it may explain some of the less accurate and less reliable results in previous studies where transducer force was not taken into consideration. Future studies in the left lobe of the liver should take this into account and control for applied transducer force.

Integrated Interpretation of Geophysical, Geotechnical, and Environmental Monitoring Data to Define Precursors for Landslide Activation

NASA Astrophysics Data System (ADS)

Uhlemann, S.; Chambers, J.; Merritt, A.; Wilkinson, P.; Meldrum, P.; Gunn, D.; Maurer, H.; Dixon, N.

2014-12-01

To develop a better understanding of the failure mechanisms leading to first time failure or reactivation of landslides, the British Geological Survey is operating an observatory on an active, shallow landslide in North Yorkshire, UK, which is a typical example of slope failure in Lias Group mudrocks. This group and the Whitby Mudstone Formation in particular, show one of the highest landslide densities in the UK. The observatory comprises geophysical (i.e., ERT and self-potential monitoring, P- and S-wave tomography), geotechnical (i.e. acoustic emission and inclinometer), and hydrological and environmental monitoring (i.e. weather station, water level, soil moisture, soil temperature), in addition to movement monitoring using real-time kinematic GPS. In this study we focus on the reactivation of the landslide at the end of 2012, after an exceptionally wet summer. We present an integrated interpretation of the different data streams. Results show that the two lobes (east and west), which form the main focus of the observatory, behave differently. While water levels, and hence pore pressures, in the eastern lobe are characterised by a continuous increase towards activation resulting in significant movement (i.e. metres), water levels in the western lobe are showing frequent drainage events and thus lower pore pressures and a lower level of movement (i.e. tens of centimetres). This is in agreement with data from the geoelectrical monitoring array. During the summer season, resistivities generally increase due to decreasing moisture levels. However, during the summer of 2012 this seasonal pattern was interrupted, with the reactivated lobe displaying strongly decreasing resistivities (i.e. increasing moisture levels). The self-potential and soil moisture data show clear indications of moisture accumulation prior to the reactivation, followed by continuous discharge towards the base of the slope. Using the different data streams, we present 3D volumetric images of gravimetric moisture content (derived from the ERT data) that highlight the reasons for the differential behaviour and indicate precursors for landslide reactivation.

Experimental river delta size set by multiple floods and backwater hydrodynamics.

PubMed

Ganti, Vamsi; Chadwick, Austin J; Hassenruck-Gudipati, Hima J; Fuller, Brian M; Lamb, Michael P

2016-05-01

River deltas worldwide are currently under threat of drowning and destruction by sea-level rise, subsidence, and oceanic storms, highlighting the need to quantify their growth processes. Deltas are built through construction of sediment lobes, and emerging theories suggest that the size of delta lobes scales with backwater hydrodynamics, but these ideas are difficult to test on natural deltas that evolve slowly. We show results of the first laboratory delta built through successive deposition of lobes that maintain a constant size. We show that the characteristic size of delta lobes emerges because of a preferential avulsion node-the location where the river course periodically and abruptly shifts-that remains fixed spatially relative to the prograding shoreline. The preferential avulsion node in our experiments is a consequence of multiple river floods and Froude-subcritical flows that produce persistent nonuniform flows and a peak in net channel deposition within the backwater zone of the coastal river. In contrast, experimental deltas without multiple floods produce flows with uniform velocities and delta lobes that lack a characteristic size. Results have broad applications to sustainable management of deltas and for decoding their stratigraphic record on Earth and Mars.

Experimental river delta size set by multiple floods and backwater hydrodynamics

PubMed Central

Ganti, Vamsi; Chadwick, Austin J.; Hassenruck-Gudipati, Hima J.; Fuller, Brian M.; Lamb, Michael P.

2016-01-01

River deltas worldwide are currently under threat of drowning and destruction by sea-level rise, subsidence, and oceanic storms, highlighting the need to quantify their growth processes. Deltas are built through construction of sediment lobes, and emerging theories suggest that the size of delta lobes scales with backwater hydrodynamics, but these ideas are difficult to test on natural deltas that evolve slowly. We show results of the first laboratory delta built through successive deposition of lobes that maintain a constant size. We show that the characteristic size of delta lobes emerges because of a preferential avulsion node—the location where the river course periodically and abruptly shifts—that remains fixed spatially relative to the prograding shoreline. The preferential avulsion node in our experiments is a consequence of multiple river floods and Froude-subcritical flows that produce persistent nonuniform flows and a peak in net channel deposition within the backwater zone of the coastal river. In contrast, experimental deltas without multiple floods produce flows with uniform velocities and delta lobes that lack a characteristic size. Results have broad applications to sustainable management of deltas and for decoding their stratigraphic record on Earth and Mars. PMID:27386534

Is there a creative functional paradoxical facilitation in juvenile myoclonic epilepsy?

PubMed

Senf, Philine; Scheuren, Lena; Holtkamp, Martin

2016-09-01

In patients with juvenile myoclonic epilepsy (JME), a specific personality profile suggestive of frontal lobe dysfunctions has been described. From a neurobiological point of view, the frontal lobe seems to be crucial for creative processes, although the exact role remains unclear. The theory of creative paradoxical functional facilitation (PFF) assumes that disinhibited frontal lobe function can enhance creative abilities. The aim of the current study was to explore our hypothesis that JME is associated with higher artistic creativity based on the theory of PFF. We assessed 25 patients with JME aged 18 to 40years in regard to neuropsychological creativity testing. Results were compared with those of 25 age-, sex-, and level of education-matched healthy control subjects (HC) and patients with temporal lobe epilepsy (TLE). Creative abilities were assessed using two validated and standardized tests: 1) nonverbal: the incomplete figure task of Torrance Test of Creative Thinking and 2) verbal: verbal creativity test. Additionally, a basic assessment of fluid intelligence (test for problem solving) and frontal lobe function (trail-making test) was administered to all participants. Verbal creativity was impaired in both groups with epilepsy compared with that in HC (specific score: JME vs. HC, p=0.008; TLE vs. HC, p=0.003). In regard to nonverbal creative abilities, both groups with epilepsy exhibited fair performance. Level of fluid intelligence was even in all groups (p=0.433). Only patients with JME showed deficits in the frontal lobe test of psychomotor speed (time in seconds: 67.7 JME vs. 54.6 TLE vs. 52.8 HC; p=0.045). Overall, our study did not reveal increased creativity in JME. The current findings provide insights into creative abilities in two different epilepsy syndromes. Knowledge on specific neuropsychological strengths or deficits in patients with epilepsy may be useful for treatment or counseling. Copyright © 2016 Elsevier Inc. All rights reserved.

Space Shuttle Main Engine High Pressure Fuel Turbopump Turbine Blade Cracking

NASA Technical Reports Server (NTRS)

Lee, Henry

1988-01-01

The analytical results from two-dimensional (2D) and three-dimensional (3D) finite element model investigations into the cracking of Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) first- and second-stage turbine blades are presented. Specifically, the initiation causes for transverse cracks on the pressure side of the firststage blade fir tree lobes and face/corner cracks on the downstream fir tree face of the second-state blade are evaluated. Because the blade material, MAR-M-246 Hf (DS), is highly susceptible to hydrogen embrittlement in the -100 F to 400 F thermal environment, a steady-state condition (full power level = 109 percent) rather than a start-up or shut-down transient was considered to be the most likely candidate for generating a high-strain state in the fir tree areas. Results of the analyses yielded strain levels on both first- and second-stage blade fir tree regions that are of a magnitude to cause hydrogen assisted low cycle fatigue cracking. Also evident from the analysis is that a positive margin against fir tree cracking exists for the planned design modifications, which include shot peening for both first- and second-stage blade fir tree areas.

Life-threatening intrathyroidal parathyroid adenoma

PubMed Central

Dogan, Ugur; Koc, Umit; Mayir, Burhan; Habibi, Mani; Dogan, Berna; Gomceli, Ismail; Bulbuller, Nurullah

2015-01-01

Acute primary hyperparathyroidism and parathyroid crisis are characterized by life-threatening hypercalcemia, a rare disorder. A 69-year-old female patient presented at our hospital’s neurology clinic with weakness, nausea, vomiting, depression, and hypercalcemia. Treatment of hypercalcemia resulted in no improvement in neurological symptoms, indicating resistance to treatment. Thyroid ultrasonography and parathyroid scintigraphy revealed hypoechoic nodules in the right lobe, pieces of nodules in the left lobe, and high serum calcium and parathyroid hormone levels. After provision of intensive medical treatment including hydration, diuresis, and bisphosphonate infusion resulted in only minimal decrease in the calcium level, urgent surgical treatment was performed. Frozen biopsy of the right intrathyroidal giant parathyroid adenoma in the right lobe confirmed initial diagnosis of primary hyperparathyroidism. Based on the biopsy findings, right parathyroidectomy and right total and left subtotal thyroidectomy were performed. Histopathologic examination revealed a parathyroid adenoma localized inside large thyroid nodules. Review of the findings resulted in diagnosis of intrathyroidal parathyroid adenoma. Symptoms of hypercalcemia improved rapidly during the postoperative period. PMID:25785164

Controlling satellite communication system unwanted emissions in congested RF spectrum

NASA Astrophysics Data System (ADS)

Olsen, Donald; Heymann, Roger

2007-09-01

The International Telecommunication Union (ITU), a United Nations (UN) agency, is the agency that, under an international treaty, sets radio spectrum usage regulations among member nations. Within the United States of America (USA), the organization that sets regulations, coordinates an application for use, and provides authorization for federal government/agency use of the radio frequency (RF) spectrum is the National Telecommunications and Information Administration (NTIA). In this regard, the NTIA defines which RF spectrum is available for federal government use in the USA, and how it is to be used. The NTIA is a component of the United States (U.S.) Department of Commerce of the federal government. The significance of ITU regulations is that ITU approval is required for U.S. federal government/agency permission to use the RF spectrum outside of U.S. boundaries. All member nations have signed a treaty to do so. U.S. federal regulations for federal use of the RF spectrum are found in the Manual of Regulations and Procedures for Federal Radio Frequency Management, and extracts of the manual are found in what is known as the Table of Frequency Allocations. Nonfederal government and private sector use of the RF spectrum within the U.S. is regulated by the Federal Communications Commission (FCC). There is a need to control "unwanted emissions" (defined to include out-of-band emissions, which are those immediately adjacent to the necessary and allocated bandwidth, plus spurious emissions) to preclude interference to all other authorized users. This paper discusses the causes, effects, and mitigation of unwanted RF emissions to systems in adjacent spectra. Digital modulations are widely used in today's satellite communications. Commercial communications sector standards are covered for the most part worldwide by Digital Video Broadcast - Satellite (DVB-S) and digital satellite news gathering (DSNG) evolutions and the second generation of DVB-S (DVB-S2) standard, developed by the European Telecommunications Standards Institute (ETSI). In the USA, the Advanced Television Systems Committee (ATSC) has adopted Europe's DVB-S and DVB-S2 standards for satellite digital transmission. With today's digital modulations, RF spectral side lobes can extend out many times the modulating frequency on either side of the carrier at excessive power levels unless filtered. Higher-order digital modulations include quadrature phase shift keying (QPSK), 8 PSK (8-ary phase shift keying), 16 APSK (also called 12-4 APSK (amplitude phase shift keying)), and 16 QAM (quadrature amplitude modulation); they are key for higher spectrum efficiency to enable higher data rate transmissions in limited available bandwidths. Nonlinear high-power amplifiers (HPAs) can regenerate frequency spectral side lobes on input-filtered digital modulations. The paper discusses technologies and techniques for controlling these spectral side lobes, such as the use of square root raised cosine (SRRC) filtering before or during the modulation process, HPA output power back-off (OPBO), and RF filters after the HPA. Spectral mask specifications are a common method of the NTIA and ITU to define spectral occupancy power limits. They are intended to reduce interference among RF spectrum users by limiting excessive radiation at frequencies beyond the regulatory allocated bandwidth.The focus here is on the communication systems of U.S. government satellites used for space research, space operations, Earth exploration satellite services (EESS), meteorological satellite services (METSATS), and other government services. The 8025 to 8400 megahertz (MHz) X band can be used to illustrate the "unwanted emissions" issue. 8025 to 8400 MHz abuts the 8400 to 8450 MHz band allocated by the NTIA and ITU to space research for space-to-Earth transmissions such as receiving very weak Deep Space Network signals. The views and ideas expressed in this paper are those of the authors and do not necessarily reflect those of The Aerospace Corporation or The National Oceanic and Atmospheric Administration (NOAA) and its National Environmental Satellite Service (NESDIS).

Fornix and medial temporal lobe lesions lead to comparable deficits in complex visual perception.

PubMed

Lech, Robert K; Koch, Benno; Schwarz, Michael; Suchan, Boris

2016-05-04

Recent research dealing with the structures of the medial temporal lobe (MTL) has shifted away from exclusively investigating memory-related processes and has repeatedly incorporated the investigation of complex visual perception. Several studies have demonstrated that higher level visual tasks can recruit structures like the hippocampus and perirhinal cortex in order to successfully perform complex visual discriminations, leading to a perceptual-mnemonic or representational view of the medial temporal lobe. The current study employed a complex visual discrimination paradigm in two patients suffering from brain lesions with differing locations and origin. Both patients, one with extensive medial temporal lobe lesions (VG) and one with a small lesion of the anterior fornix (HJK), were impaired in complex discriminations while showing otherwise mostly intact cognitive functions. The current data confirmed previous results while also extending the perceptual-mnemonic theory of the MTL to the main output structure of the hippocampus, the fornix. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Sulci of the liver found after death: Their nature and potential teaching value.

PubMed

Macchi, V; Porzionato, A; Stecco, C; Parenti, A; Newell, R L M; De Caro, R

2013-07-01

Accessory sulci of the liver are more commonly found after death than in life, raising questions as to their causation and possible classification. We have analyzed a group of 180 livers sampled from un-embalmed (96) and embalmed cadavers (84). In un-embalmed cadavers, no accessory sulci were found on the diaphragmatic surface in 58 cases. Diaphragmatic sulci were found in the right lobe of 38 livers. When removed from the abdominal cavity and placed flat on the examination table (the "bench position") all 58 livers without sulci appreciable in the abdominal cavity showed the appearance of two sulci. The first ran from the right side of the inferior vena cava (IVC), curving anteriorly to the inferior border of the liver, at a point midway between the right extremity of the inferior border and the gallbladder fossa, concave towards the left. The second sulcus ran from the left side of the IVC, curving anteriorly to reach the inferior border of the liver at the level of the gallbladder fossa, concave towards the right. With progressive side-to-side manual compression, the sulci on the diaphragmatic surface become more evident. Division of the hepatic parenchyma along the two sulci exposed the right and middle hepatic veins respectively in more than 90% of cases. In embalmed cadavers, 24 livers showed antero-posterior sulci in the superior surface, visible and palpable on the liver examined in situ. When the livers with sulci had been removed from the abdomen for further examination, the appearance of the superior surface did not change. In a removed liver, accessory sulci can be divided into true, "diaphragmatic," sulci and "false" sulci due to the position of the free liver on the examination table. The "false" sulci may be considered as further morphological evidence of the functional anatomical division of the liver. Their demonstration may also be useful in teaching its topographical and surgical anatomy. Copyright © 2012 Wiley Periodicals, Inc.

Clinical evidence of parietal cortex dysfunction and correlation with extent of allodynia in CRPS type 1.

PubMed

Cohen, H; McCabe, C; Harris, N; Hall, J; Lewis, J; Blake, D R

2013-04-01

Unusual symptoms such as digit misidentification and neglect-like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction. Twenty-two patients with chronic CRPS attending an in-patient rehabilitation programme underwent standard neurological examination followed by clinical assessment of parietal lobe function and detailed sensory testing. Fifteen (68%) patients had evidence of parietal lobe dysfunction. Six (27%) subjects failed six or more test categories and demonstrated new clinical signs consistent with their parietal testing impairments, which were impacting significantly on activities of daily living. A higher incidence was noted in subjects with >1 limb involvement, CRPS affecting the dominant side and in left-handed subjects. Eighteen patients (82%) had mechanical allodynia covering 3-57.5% of the body surface area. Allochiria (unilateral tactile stimulation perceived only in the analogous location on the opposite limb), sensory extinction (concurrent bilateral tactile stimulation perceived only in one limb), referred sensations (unilateral tactile stimulation perceived concurrently in another discrete body area) and dysynchiria (unilateral non-noxious tactile stimulation perceived bilaterally as noxious) were present in some patients. Greater extent of body surface allodynia was correlated with worse parietal function (Spearman's rho = -0.674, p = 0.001). In patients with chronic CRPS, detailed clinical examination may reveal parietal dysfunction, with severity relating to the extent of allodynia. © 2012 European Federation of International Association for the Study of Pain Chapters.

Three-dimensional Fourier transform evaluation of sequences of spatially and temporally modulated speckle interferograms.

PubMed

Trillo, C; Doval, A F; López-Vázquez, J C

2010-07-05

Phase evaluation methods based on the 2D spatial Fourier transform of a speckle interferogram with spatial carrier usually assume that the Fourier spectrum of the interferogram has a trimodal distribution, i. e. that the side lobes corresponding to the interferential terms do not overlap the other two spectral terms, which are related to the intensity of the object and reference beams, respectively. Otherwise, part of the spectrum of the object beam is inside the inverse-transform window of the selected interference lobe and induces an error in the resultant phase map. We present a technique for the acquisition and processing of speckle interferogram sequences that separates the interference lobes from the other spectral terms when the aforementioned assumption does not apply and regardless of the temporal bandwidth of the phase signal. It requires the recording of a sequence of interferograms with spatial and temporal carriers, and their processing with a 3D Fourier transform. In the resultant 3D spectrum, the spatial and temporal carriers separate the conjugate interferential terms from each other and from the term related to the object beam. Experimental corroboration is provided through the measurement of the amplitude of surface acoustic waves in plates with a double-pulsed TV holography setup. The results obtained with the proposed method are compared to those obtained with the processing of individual interferograms with the regular spatial-carrier 2D Fourier transform method.

Venus - Impact Crater 'Jeanne

NASA Technical Reports Server (NTRS)

1991-01-01

This Magellan full-resolution image shows Jeanne crater, a 19.5 kilometer (12 mile) diameter impact crater. Jeanne crater is located at 40.0 degrees north latitude and 331.4 degrees longitude. The distinctive triangular shape of the ejecta indicates that the impacting body probably hit obliquely, traveling from southwest to northeast. The crater is surrounded by dark material of two types. The dark area on the southwest side of the crater is covered by smooth (radar-dark) lava flows which have a strongly digitate contact with surrounding brighter flows. The very dark area on the northeast side of the crater is probably covered by smooth material such as fine-grained sediment. This dark halo is asymmetric, mimicking the asymmetric shape of the ejecta blanket. The dark halo may have been caused by an atmospheric shock or pressure wave produced by the incoming body. Jeanne crater also displays several outflow lobes on the northwest side. These flow-like features may have formed by fine-grained ejecta transported by a hot, turbulent flow created by the arrival of the impacting object. Alternatively, they may have formed by flow of impact melt.

Left inferior parietal lobe engagement in social cognition and language.

PubMed

Bzdok, Danilo; Hartwigsen, Gesa; Reid, Andrew; Laird, Angela R; Fox, Peter T; Eickhoff, Simon B

2016-09-01

Social cognition and language are two core features of the human species. Despite distributed recruitment of brain regions in each mental capacity, the left parietal lobe (LPL) represents a zone of topographical convergence. The present study quantitatively summarizes hundreds of neuroimaging studies on social cognition and language. Using connectivity-based parcellation on a meta-analytically defined volume of interest (VOI), regional coactivation patterns within this VOI allowed identifying distinct subregions. Across parcellation solutions, two clusters emerged consistently in rostro-ventral and caudo-ventral aspects of the parietal VOI. Both clusters were functionally significantly associated with social-cognitive and language processing. In particular, the rostro-ventral cluster was associated with lower-level processing facets, while the caudo-ventral cluster was associated with higher-level processing facets in both mental capacities. Contrarily, in the (less stable) dorsal parietal VOI, all clusters reflected computation of general-purpose processes, such as working memory and matching tasks, that are frequently co-recruited by social or language processes. Our results hence favour a rostro-caudal distinction of lower- versus higher-level processes underlying social cognition and language in the left inferior parietal lobe. Copyright © 2016 Elsevier Ltd. All rights reserved.

Shed a light in fatigue detection with near-infrared spectroscopy during long-lasting driving

NASA Astrophysics Data System (ADS)

Gao, Yuan; Pan, Boan; Li, Kai; Li, Ting

2016-03-01

Fatigue driving is one of the leading roles to induce traffic accident and injury, which urgently desires a novel technique to monitor the fatigue level at driving. Functional near infrared spectroscopy (fNIRS) is capable of noninvasive monitoring brain-activities-related hemodynamic responses. Here, we developed a fINRS imager and setup a classic psychological experiment to trigger visual divided attention which varied responding to driving fatigue, and attempted to record the drive-fatigue-level correlated hemodynamic response in the prefrontal cortex. 7 volunteers were recruited to take 7 hours driving and the experimental test was repeated every 1 hour and 8 times in total. The hemodynamic response were extracted and graphed with pseudo image. The analysis on the relationship between the fNIRS-measured hemodynamic response and fatigue level finally displayed that the oxyhemoglobin concentration in one channel of left prefrontal lobe increased with driving duration in significant correlation. And the spatial pattern of hemodynamic response in the prefrontal lobe varied with driving duration as well. The findings indicated the potential of fNIRSmeasured hemodynamic index in some sensitive spot of prefrontal lobe as a driving fatigue indicator and the promising use of fNIRS in traffic safety field.

Neural Correlates of Subliminal Language Processing

PubMed Central

Axelrod, Vadim; Bar, Moshe; Rees, Geraint; Yovel, Galit

2015-01-01

Language is a high-level cognitive function, so exploring the neural correlates of unconscious language processing is essential for understanding the limits of unconscious processing in general. The results of several functional magnetic resonance imaging studies have suggested that unconscious lexical and semantic processing is confined to the posterior temporal lobe, without involvement of the frontal lobe—the regions that are indispensable for conscious language processing. However, previous studies employed a similarly designed masked priming paradigm with briefly presented single and contextually unrelated words. It is thus possible, that the stimulation level was insufficiently strong to be detected in the high-level frontal regions. Here, in a high-resolution fMRI and multivariate pattern analysis study we explored the neural correlates of subliminal language processing using a novel paradigm, where written meaningful sentences were suppressed from awareness for extended duration using continuous flash suppression. We found that subjectively and objectively invisible meaningful sentences and unpronounceable nonwords could be discriminated not only in the left posterior superior temporal sulcus (STS), but critically, also in the left middle frontal gyrus. We conclude that frontal lobes play a role in unconscious language processing and that activation of the frontal lobes per se might not be sufficient for achieving conscious awareness. PMID:24557638

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.

Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

NASA Technical Reports Server (NTRS)

Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

2014-01-01

NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

NASA Astrophysics Data System (ADS)

Smith, Nathan; Ginsburg, Adam; Bally, John

2018-03-01

We present Atacama Large Millimeter Array (ALMA) observations of 12CO 2-1 emission from circumstellar material around the massive star Eta Carinae (η Car). These observations reveal new structural details about the cool equatorial torus located ˜4000 au from the star. The CO torus is not a complete azimuthal loop, but rather, is missing its near side, which appears to have been cleared away. The missing material matches the direction of apastron in the eccentric binary system, making it likely that η Car's companion played an important role in disrupting portions of the torus soon after ejection. Molecular gas seen in ALMA data aligns well with the cool dust around η Car previously observed in mid-infrared (IR) maps, whereas hot dust resides at the inner surface of the molecular torus. The CO also coincides with the spatial and velocity structure of near-IR H2 emission. Together, these suggest that the CO torus seen by ALMA is actually the pinched waist of the Homunculus polar lobes, which glows brightly because it is close to the star and warmer than the poles. The near side of the torus appears to be a blowout, associated with fragmented equatorial ejecta. We discuss implications for the origin of various features north-west of the star. CO emission from the main torus implies a total gas mass in the range of 0.2-1 M⊙ (possibly up to 5 M⊙ or more, although with questionable assumptions). Deeper observations are needed to constrain CO emission from the cool polar lobes.

Thermal oxidation saves $500,000, lifts capacity, upholds compliance

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

Harley, C.G.; Nagy, A.J.; Sendecki, M.

1985-12-01

The age and destruction of the heat recovery system dictated the replacement of the original fume incinerator at the Congoleum Resilient Flooring Division Plant in Trenton, NJ. The original unit, installed in 1967, had a conventional air-to-oil heat recovery system. Plant personnel placed high priority on finding a replacement with a higher thermal efficiency while still maintaining environmental integrity. A proprietary software program was used to obtain values for NPV (net pressure value) for several competitive equipment systems. The NPV allows simple comparison of equipment based on data such as purchase pgsrice, cost of installation, operating costs, and maintenance costsmore » for the predicted life span of each unit. Based on NPV analysis, a regenerative thermal oxidation unit was selected. To assure expansion capability, Congoleum opted for a 30,000 scfm system. The regenerative thermal oxidation unit consists of a central combustion chamber with five lobes extending radially outward. Each lobe is packed with ceramic refractory elements (saddles) which serve as heat exchange media. The elements are retained by perforated refractory blocks on the hot combustion chamber side and by a grating on the cold side. Estimated savings from the system, about a half million dollars the first year, are expected to significantly exceed Congoleum's original estimates. About half of the total savings will result from reduced consumption of natural gas since the unit is fueled mainly by the organic material in the process exhaust. The other half of the savings has resulted from improvements in production efficiency and the recycling of waste heat from the thermal oxidizer.« less

Effects of duloxetine on microRNA expression profile in frontal lobe and hippocampus in a mouse model of depression.

PubMed

Pan, Bing; Liu, Yamei

2015-01-01

Depression is a major mood disorder affecting people worldwide. The posttranscriptional gene regulation mediated by microRNAs (miRNAs) which may have critical roles in the pathogenesis of depression. However, to date, little is known about the effects of the antidepressant drug duloxetine on miRNA expression profile in chronic unpredictable mild stress (CUMS)-induced depression model in mice. Healthy adult male Kunming mice were randomly divided into three groups: control group, model group and duloxetine group. Sucrose preference test and open field test were used to represent the behavioral change. MiRNAs levels in frontal lobe and hippocampus of mice were analyzed using miRNA microarrays assay. We observed that long-term treatment with duloxetine significantly ameliorated the CUMS procedure-induced sucrose preference decreases and mice treated with duloxetine demonstrated a reversal of the number of crossings, and rearings reduced by CUMS. A significant upregulation of miR-132 and miR-18a in hippocampus in the duloxetine treatment group compared with model group, whereas the levels of miR-134 and miR-124a were significantly downregulated. Furthermore, miR-18a showed significant upregulation in frontal lobe in the duloxetine treatment group relative to model group. Our data showed that miRNA expression profile in frontal lobe and hippocampus was affected by duloxetine in mice model of depression. The effect was especially pronounced in the hippocampus, suggesting that hippocampus might be the action site of duloxetine, which presumably worked by regulating the expression of miRNA levels.

Determining Surgical Candidacy in Temporal Lobe Epilepsy

PubMed Central

Mansouri, Alireza; Fallah, Aria; Valiante, Taufik A.

2012-01-01

Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy that is amenable to surgical treatment. In the carefully selected patient, excellent seizure outcome can be achieved with minimal or no side effects from surgery. This may result in improved psychosocial functioning, achieving higher education, and maintaining or gaining employment. The objective of this paper is to discuss the surgical selection process of a patient with TLE. We define what constitutes a patient that has medically refractory TLE, describe the typical history and physical examination, and distinguish between mesial TLE and neocortical TLE. We then review the role of routine (ambulatory/sleep-deprived electroencephalography (EEG), video EEG, magnetic resonance imaging (MRI), neuropsychological testing, and Wada testing) and ancillary preoperative testing (positron emission tomography, single-photon emission computed tomography (SPECT), subtraction ictal SPECT correlated to MRI (SISCOM), magnetoencephalography, magnetic resonance spectroscopy, and functional MRI) in selecting surgical candidates. We describe the surgical options for resective epilepsy surgery in TLE and its commonly associated risks while highlighting some of the controversies. Lastly, we present teaching cases to illustrate the presurgical workup of patients with medically refractory TLE. PMID:22957238

Modeling ADHD-type arousal with unilateral frontal cortex damage in rats and beneficial effects of play therapy.

PubMed

Panksepp, Jaak; Burgdorf, Jeff; Turner, Cortney; Gordon, Nakia

2003-06-01

It has been recently shown that human adolescents with Attention Deficit/Hyperactivity Disorder (ADHD) have frontal lobe deficits, especially on the right sides of their brains (). ADHD is commonly treated with psychostimulants which may have adverse consequences. Hence, less invasive therapies need to be developed. In the present work, we tested the ability of right frontal lesions to induce hyperactivity in rats. We also evaluated the effects of chronic play therapy during early adolescence to reduce both hyperactivity and the elevated playfulness later in development. Play therapy was able to reduce both hyperactivity and excessive playfulness. In additional work, we found that access to rough-and-tumble play in normal animals could enhance subsequent behavioral indices of behavioral inhibition (i.e., freezing in response to a startle stimulus) that appeared to be independent of increased fearfulness and fatigue. Overall, these results suggest that (1) neonatal frontal lobe lesions can be used as an animal model of the overactivity in ADHD and (2) rough-and-tumble play therapy may be a new useful treatment for ADHD.

Neurobehavioral and neurometabolic (SPECT) correlates of paranormal information: involvement of the right hemisphere and its sensitivity to weak complex magnetic fields.

PubMed

Roll, W G; Persinger, M A; Webster, D L; Tiller, S G; Cook, C M

2002-02-01

Experiments were designed to help elucidate the neurophysiological correlates for the experiences reported by Sean Harribance. For most of his life he has routinely experienced "flashes of images" of objects that were hidden and of accurate personal information concerning people with whom he was not familiar. The specificity of details for target pictures of people was correlated positively with the proportion of occipital alpha activity. Results from a complete neuropsychological assessment, Single Photon Emission Computed Tomography (SPECT), and screening electroencephalography suggested that his experiences were associated with increased activity within the parietal lobe and occipital regions of the right hemisphere. Sensed presences (subjectively localized to his left side) were evoked when weak, magnetic fields, whose temporal structure simulated long-term potentiation in the hippocampus, were applied over his right temporoparietal lobes. These results suggest that the phenomena attributed to paranormal or "extrasensory" processes are correlated quantitatively with morphological and functional anomalies involving the right parietotemporal cortices (or its thalamic inputs) and the hippocampal formation.

The right hippocampus leads the bilateral integration of gamma-parsed lateralized information

PubMed Central

Benito, Nuria; Martín-Vázquez, Gonzalo; Makarova, Julia; Makarov, Valeri A; Herreras, Oscar

2016-01-01

It is unclear whether the two hippocampal lobes convey similar or different activities and how they cooperate. Spatial discrimination of electric fields in anesthetized rats allowed us to compare the pathway-specific field potentials corresponding to the gamma-paced CA3 output (CA1 Schaffer potentials) and CA3 somatic inhibition within and between sides. Bilateral excitatory Schaffer gamma waves are generally larger and lead from the right hemisphere with only moderate covariation of amplitude, and drive CA1 pyramidal units more strongly than unilateral waves. CA3 waves lock to the ipsilateral Schaffer potentials, although bilateral coherence was weak. Notably, Schaffer activity may run laterally, as seen after the disruption of the connecting pathways. Thus, asymmetric operations promote the entrainment of CA3-autonomous gamma oscillators bilaterally, synchronizing lateralized gamma strings to converge optimally on CA1 targets. The findings support the view that interhippocampal connections integrate different aspects of information that flow through the left and right lobes. DOI: http://dx.doi.org/10.7554/eLife.16658.001 PMID:27599221

Simulating memory outcome before right selective amygdalohippocampectomy.

PubMed

Patrikelis, Panayiotis; Lucci, Giuliana; Siatouni, Anna; Zalonis, Ioannis; Sakas, Damianos E; Gatzonis, Stylianos

2013-01-01

In this paper we present the case of a left-sided speech dominant patient with right medial temporal sclerosis (RMTS) and pharmacoresistant epilepsy who showed improved verbal memory during intracarotid amobarbital test (IAT) at his right hemisphere as compared with his own performance before the drug injection (baseline), as well as after right selective amygdalohippocampectomy. We suggest that the defective verbal memory shown by this patient is due to abnormal activity of his right hippocampus that interfered with the function of his left hippocampus. This hypothesis was demonstrated by the fact that disconnection of the two hippocampi, either by anesthetisation or by resection of the right hippocampus, disengaged the left hippocampus and, consequently improved its function. This paper main objective is twofold: first to contribute to the field of neuropsychology of epilepsy surgery by emphasising on postoperative memory outcomes in right medial temporal lobe epilepsy (RMTLE) patients, particularly those undergoing amygdalohippocampectomy, as the pattern of memory changes after resection of the right temporal lobe is less clear; second, by focusing on memory performance asymmetries during IAT, and comparatively considering them with neuropsychological memory performance, because of their possible prognostic-simulating value.

Single-Side Two-Location Spotlight Imaging for Building Based on MIMO Through-Wall-Radar.

PubMed

Jia, Yong; Zhong, Xiaoling; Liu, Jiangang; Guo, Yong

2016-09-07

Through-wall-radar imaging is of interest for mapping the wall layout of buildings and for the detection of stationary targets within buildings. In this paper, we present an easy single-side two-location spotlight imaging method for both wall layout mapping and stationary target detection by utilizing multiple-input multiple-output (MIMO) through-wall-radar. Rather than imaging for building walls directly, the images of all building corners are generated to speculate wall layout indirectly by successively deploying the MIMO through-wall-radar at two appropriate locations on only one side of the building and then carrying out spotlight imaging with two different squint-views. In addition to the ease of implementation, the single-side two-location squint-view detection also has two other advantages for stationary target imaging. The first one is the fewer multi-path ghosts, and the second one is the smaller region of side-lobe interferences from the corner images in comparison to the wall images. Based on Computer Simulation Technology (CST) electromagnetic simulation software, we provide multiple sets of validation results where multiple binary panorama images with clear images of all corners and stationary targets are obtained by combining two single-location images with the use of incoherent additive fusion and two-dimensional cell-averaging constant-false-alarm-rate (2D CA-CFAR) detection.

What role does the anterior temporal lobe play in sentence-level processing? Neural correlates of syntactic processing in semantic PPA

PubMed Central

Wilson, Stephen M.; DeMarco, Andrew T.; Henry, Maya L.; Gesierich, Benno; Babiak, Miranda; Mandelli, Maria Luisa; Miller, Bruce L.; Gorno-Tempini, Maria Luisa

2014-01-01

Neuroimaging and neuropsychological studies have implicated the anterior temporal lobe (ATL) in sentence-level processing, with syntactic structure-building and/or combinatorial semantic processing suggested as possible roles. A potential challenge to the view that the ATL is involved in syntactic aspects of sentence processing comes from the clinical syndrome of semantic variant primary progressive aphasia (semantic PPA, also known as semantic dementia). In semantic PPA, bilateral neurodegeneration of the anterior temporal lobes is associated with profound lexical semantic deficits, yet syntax is strikingly spared. The goal of this study was to investigate the neural correlates of syntactic processing in semantic PPA, in order to determine which regions normally involved in syntactic processing are damaged in semantic PPA, and whether spared syntactic processing depends on preserved functionality of intact regions, preserved functionality of atrophic regions, or compensatory functional reorganization. We scanned 20 individuals with semantic PPA and 24 age-matched controls using structural and functional MRI. Participants performed a sentence comprehension task that emphasized syntactic processing and minimized lexical semantic demands. We found that in controls, left inferior frontal and left posterior temporal regions were modulated by syntactic processing, while anterior temporal regions were not significantly modulated. In the semantic PPA group, atrophy was most severe in the anterior temporal lobes, but extended to the posterior temporal regions involved in syntactic processing. Functional activity for syntactic processing was broadly similar in patients and controls; in particular, whole-brain analyses revealed no significant differences between patients and controls in the regions modulated by syntactic processing. The atrophic left anterior temporal lobe did show abnormal functionality in semantic PPA patients, however this took the unexpected form of a failure to deactivate. Taken together, our findings indicate that spared syntactic processing in semantic PPA depends on preserved functionality of structurally intact left frontal regions and moderately atrophic left posterior temporal regions, but no functional reorganization was apparent as a consequence of anterior temporal atrophy and dysfunction. These results suggest that the role of the anterior temporal lobe in sentence processing is less likely to relate to syntactic structure-building, and more likely to relate to higher level processes such as combinatorial semantic processing. PMID:24345172

Frontal lobe function and behavioral changes in amyotrophic lateral sclerosis: a study from Southwest China.

PubMed

Wei, QianQian; Chen, XuePing; Zheng, ZhenZhen; Huang, Rui; Guo, XiaoYan; Cao, Bei; Zhao, Bi; Shang, Hui-Fang

2014-12-01

Despite growing interest, the frequency and characteristics of frontal lobe functional and behavioral deficits in Chinese people with amyotrophic lateral sclerosis (ALS), as well as their impact on the survival of ALS patients, remain unknown. The Chinese version of the frontal assessment battery (FAB) and frontal behavioral inventory (FBI) were used to evaluate 126 sporadic ALS patients and 50 healthy controls. The prevalence of frontal lobe dysfunction was 32.5%. The most notable impairment domain of the FAB was lexical fluency (30.7%). The binary logistic regression model revealed that an onset age older than 45 years (OR 5.976, P = 0.002) and a lower educational level (OR 0.858, P = 0.002) were potential determinants of an abnormal FAB. Based on the FBI score, 46.0% of patients showed varied degrees of frontal behavioral changes. The most common impaired neurobehavioral domains were irritability (25.4%), logopenia (20.6%) and apathy (19.0%). The binary logistic regression model revealed that the ALS Functional Rating Scale-Revised scale score (OR 0.127, P = 0.001) was a potential determinant of an abnormal FBI. Frontal functional impairment and the severity of frontal behavioral changes were not associated with the survival status or the progression of ALS by the cox proportional hazard model and multivariate regression analyses, respectively. Frontal lobe dysfunction and frontal behavioral changes are common in Chinese ALS patients. Frontal lobe dysfunction may be related to the onset age and educational level. The severity of frontal behavioral changes may be associated with the ALSFRS-R. However, the frontal functional impairment and the frontal behavioral changes do not worsen the progression or survival of ALS.

Altered Brain Network in Amyotrophic Lateral Sclerosis: A Resting Graph Theory-Based Network Study at Voxel-Wise Level.

PubMed

Zhou, Chaoyang; Hu, Xiaofei; Hu, Jun; Liang, Minglong; Yin, Xuntao; Chen, Lin; Zhang, Jiuquan; Wang, Jian

2016-01-01

Amyotrophic lateral sclerosis (ALS) is a rare degenerative disorder characterized by loss of upper and lower motor neurons. Neuroimaging has provided noticeable evidence that ALS is a complex disease, and shown that anatomical and functional lesions extend beyond precentral cortices and corticospinal tracts, to include the corpus callosum; frontal, sensory, and premotor cortices; thalamus; and midbrain. The aim of this study is to investigate graph theory-based functional network abnormalities at voxel-wise level in ALS patients on a whole brain scale. Forty-three ALS patients and 44 age- and sex-matched healthy volunteers were enrolled. The voxel-wise network degree centrality (DC), a commonly employed graph-based measure of network organization, was used to characterize the alteration of whole brain functional network. Compared with the controls, the ALS patients showed significant increase of DC in the left cerebellum posterior lobes, bilateral cerebellum crus, bilateral occipital poles, right orbital frontal lobe, and bilateral prefrontal lobes; significant decrease of DC in the bilateral primary motor cortex, bilateral sensory motor region, right prefrontal lobe, left bilateral precuneus, bilateral lateral temporal lobes, left cingulate cortex, and bilateral visual processing cortex. The DC's z-scores of right inferior occipital gyrus were significant negative correlated with the ALSFRS-r scores. Our findings confirm that the regions with abnormal network DC in ALS patients were located in multiple brain regions including primary motor, somatosensory and extra-motor areas, supporting the concept that ALS is a multisystem disorder. Specifically, our study found that DC in the visual areas was altered and ALS patients with higher DC in right inferior occipital gyrus have more severity of disease. The result demonstrated that the altered DC value in this region can probably be used to assess severity of ALS.

Left-Sided Catamenial Pneumothorax with Thoracic Endometriosis and Bullae in the Alveolar Wall

PubMed Central

Takahashi, Ryo; Mizobuchi, Teruaki; Ebana, Hiroki; Yamanaka, Sumitaka

2016-01-01

Catamenial pneumothorax (CP) is generally caused by intraperitoneal air leaking from the uterus into the thoracic cavity via a defect in the endometrial tissue of the diaphragm and is usually detected in the right thorax. We report a case of left-sided CP caused by endometriosis in the visceral pleura and with no abnormal findings in the diaphragm. A 33-year-old female patient presented at the end of a course of low-dose contraceptive pills for pelvic endometriosis, with spontaneous pneumothorax in the left chest. Chest CT revealed a bulla in the left upper lung lobe. The patient underwent partial resection of the lung. Immunohistochemistry confirmed the presence of endometrial stromal tissue in the visceral pleura and confirmed this as the cause of pneumothorax since there were no observable abnormalities in the diaphragm. This case suggests that immunohistochemical examination of patients with spontaneous pneumothorax can detect alternative endometrial lesions. PMID:27507105

Left-Sided Catamenial Pneumothorax with Thoracic Endometriosis and Bullae in the Alveolar Wall.

PubMed

Takahashi, Ryo; Kurihara, Masatoshi; Mizobuchi, Teruaki; Ebana, Hiroki; Yamanaka, Sumitaka

2017-04-20

Catamenial pneumothorax (CP) is generally caused by intraperitoneal air leaking from the uterus into the thoracic cavity via a defect in the endometrial tissue of the diaphragm and is usually detected in the right thorax. We report a case of left-sided CP caused by endometriosis in the visceral pleura and with no abnormal findings in the diaphragm. A 33-year-old female patient presented at the end of a course of low-dose contraceptive pills for pelvic endometriosis, with spontaneous pneumothorax in the left chest. Chest CT revealed a bulla in the left upper lung lobe. The patient underwent partial resection of the lung. Immunohistochemistry confirmed the presence of endometrial stromal tissue in the visceral pleura and confirmed this as the cause of pneumothorax since there were no observable abnormalities in the diaphragm. This case suggests that immunohistochemical examination of patients with spontaneous pneumothorax can detect alternative endometrial lesions.

Intractable epilepsy: management and therapeutic alternatives.

PubMed

Schuele, Stephan U; Lüders, Hans O

2008-06-01

More than half of patients with newly diagnosed epilepsy achieve complete seizure control without major side-effects. Patients who continue to have seizures after initial medical therapy should have an early and detailed assessment to confirm the diagnosis, to determine the underlying cause and epilepsy syndrome, and to choose an adequate treatment strategy. The risks and potential benefits of surgical procedures or experimental therapy have to be weighed against the chance of improvement and the potential side-effects of additional medical therapy. Surgery for temporal lobe epilepsy, the most common cause of focal epilepsy, can control seizures and improve quality of life in appropriately selected patients. However, around 20-30% of patients do not respond to medical or surgical treatment. The management of chronic intractable epilepsy requires comprehensive care to address the adverse events of medical treatment, quality of life issues, and comorbid disorders. Much research focuses on the experimental treatment options that offer hope of seizure reduction or cure.

[Atypical injury pattern of a pedestrian run over by an unimog in the epigastric region].

PubMed

Guddat, Saskia Sabrina; Müller-Rakow, Peter; Wiedmann, Peter; Püschel, Klaus; Tsokos, Michael

2007-01-01

Strongly intoxicated, a 37-year-old man fell in front of the right back wheel of an emergency vehicle (MB Unimog) and was run over according to eye witnesses. He died in hospital shortly afterwards. The autopsy revealed that he bled to death from a traumatic liver rupture (bursting of the right hepatic lobe and severing of a piece of tissue measuring 17 x 8 x 4 cm). There were no injuries classicaly seen in victims run over by a car. The atypical injury findings in this case are due to the special features of the accident vehicle: The Unimog (an all-wheel vehicle with a fixed rear axle and flat coils) struck the right side of the body lying on the street with its rear wheel and was then lifted over the body by its fixed axle without touching the left side.

Urolift - minimally invasive surgical BPH management.

PubMed

Pushkaran, Anish; Stainer, Victoria; Muir, Gordon; Shergill, Iqbal S

2017-03-01

An ideal treatment option for symptomatic Benign Prostatic Hyperplasia (BPH) should relieve lower urinary tract symptoms (LUTS) and restore Quality of Life (QoL). Currently available medical therapies and surgical options for symptomatic BPH have side effects that adversely affects quality of life. Prostatic urethral lift (PUL) is a novel endourology procedure that promises to relieve LUTS without the aforementioned side effects. Areas covered: We diligently reviewed all the published literature on PUL, till July 2016 using standard search criteria. Expert commentary: There is good quality evidence to establish the efficiency of PUL in treating symptomatic BPH without adversely affecting the QoL. Based on the current literature, PUL can be considered as an option for those symptomatic BPH patients with small or medium size prostates (< 80 ml) without median lobe enlargement, who failed on medical therapy or are intolerant to it and wish to preserve their sexual function.

Cerebral hemorrhage in infective endocarditis caused by Actinobacillus actinomycetemcomitans.

PubMed

Lin, Gen-Min; Chu, Kai-Min; Juan, Chun-Jung; Chang, Feng-Yee

2007-11-01

Cerebral hemorrhage occurs rarely in endocarditis caused by Actinobacillus actinomycetemcomitans. A 51-year-old man with a prosthetic mitral valve, who had been prophylactically treated (7 years) with warfarin, presented with intermittent fever. On admission, a Levine grade II/VI systolic cardiac murmur was detected. A transthoracic echocardiogram was negative for valve vegetation. Cefepime (1 g every 8 hours) was administered intravenously. On day 4, culturing of Gram-negative bacilli from blood and a transesophageal echocardiogram revealed a small oscillating filament attached to lateral mitral prosthetic ring on the atrial side. Ceftriaxone (2 g once daily) was started. Gait instability and left-side weakness developed abruptly 2 weeks later; brain magnetic resonance imaging revealed a hematoma over the right parietal-occipital lobe. Ceftriaxone was adjusted to 2 g every 12 hours. Actinobacillus actinomycetemcomitans was identified 3 weeks later. Recovery was achieved, with significant interval improvement and resolution of the cerebral lesions evident on CT.

Cerebral Oximetry as an Auxiliary Diagnostic Tool in the Diagnosis of Brain Death.

PubMed

Tatli, O; Bekar, O; Imamoglu, M; Gonenc Cekic, O; Aygun, A; Eryigit, U; Karaca, Y; Sahin, A; Turkmen, S; Turedi, S

2017-10-01

To investigate the efficacy of cerebral oximetry (CO) as an auxiliary diagnostic tool in brain death (BD). This observational case-control study was performed on patients with suspected BD. Patients with diagnosis of BD confirmed by the brain death committee were enrolled as the BD group and other patients as the non-BD group. CO monitoring was performed at least 6 h, and cerebral tissue oxygen saturation (ScO 2 ) parameters were compared. Mean ScO 2 level in the BD group was lower than non-brain-dead patients: mean difference for right lobe = 6.48 (95% confidence interval [CI] 0.08-12.88) and for left lobe = 6.09 (95% CI -0.22-12.41). Maximum ScO 2 values in the BD group were significantly lower than the non-BD group: mean difference for right lobe = 8.20 (95% CI 1.64-14.77) and for left lobe = 9.54 (95% CI 3.06-16.03). The area under the curve for right lobe maximum ScO 2 was 0.69 (95% CI 0.55-0.81) and for left lobe was 0.72 (95% CI 0.58-0.84). Maximum ScO 2 in brain-dead patients at CO monitoring is significantly low. However, this cannot be used to differentiate brain-dead and non-brain-dead patients. CO monitoring is therefore not an appropriate auxiliary diagnostic tool for confirming BD. Copyright © 2017 Elsevier Inc. All rights reserved.

Frontal Lobe Hemodynamic Responses to Painful Stimulation: A Potential Brain Marker of Nociception

PubMed Central

Steele, Sarah C.; Peng, Ke; Boas, David A.; Becerra, Lino; Borsook, David

2016-01-01

The purpose of this study was to use functional near-infrared spectroscopy (fNIRS) to examine patterns of both activation and deactivation that occur in the frontal lobe in response to noxious stimuli. The frontal lobe was selected because it has been shown to be activated by noxious stimuli in functional magnetic resonance imaging studies. The brain region is located behind the forehead which is devoid of hair, providing a relative ease of placement for fNIRS probes on this area of the head. Based on functional magnetic resonance imaging studies showing blood-oxygenation-level dependent changes in the frontal lobes, we evaluated functional near-infrared spectroscopy measures in response to two levels of electrical pain in awake, healthy human subjects (n = 10; male = 10). Each subject underwent two recording sessions separated by a 30-minute resting period. Data collected from 7 subjects were analyzed, containing a total of 38/36 low/high intensity pain stimuli for the first recording session and 27/31 pain stimuli for the second session. Our results show that there is a robust and significant deactivation in sections of the frontal cortices. Further development and definition of the specificity and sensitivity of the approach may provide an objective measure of nociceptive activity in the brain that can be easily applied in the surgical setting. PMID:27806119

Frontal Lobe Hemodynamic Responses to Painful Stimulation: A Potential Brain Marker of Nociception.

PubMed

Aasted, Christopher M; Yücel, Meryem A; Steele, Sarah C; Peng, Ke; Boas, David A; Becerra, Lino; Borsook, David

2016-01-01

The purpose of this study was to use functional near-infrared spectroscopy (fNIRS) to examine patterns of both activation and deactivation that occur in the frontal lobe in response to noxious stimuli. The frontal lobe was selected because it has been shown to be activated by noxious stimuli in functional magnetic resonance imaging studies. The brain region is located behind the forehead which is devoid of hair, providing a relative ease of placement for fNIRS probes on this area of the head. Based on functional magnetic resonance imaging studies showing blood-oxygenation-level dependent changes in the frontal lobes, we evaluated functional near-infrared spectroscopy measures in response to two levels of electrical pain in awake, healthy human subjects (n = 10; male = 10). Each subject underwent two recording sessions separated by a 30-minute resting period. Data collected from 7 subjects were analyzed, containing a total of 38/36 low/high intensity pain stimuli for the first recording session and 27/31 pain stimuli for the second session. Our results show that there is a robust and significant deactivation in sections of the frontal cortices. Further development and definition of the specificity and sensitivity of the approach may provide an objective measure of nociceptive activity in the brain that can be easily applied in the surgical setting.

Dose–Volume Relationships Associated With Temporal Lobe Radiation Necrosis After Skull Base Proton Beam Therapy

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

McDonald, Mark W., E-mail: markmcdonaldmd@gmail.com; Indiana University Health Proton Therapy Center, Bloomington, Indiana; Linton, Okechukwu R.

Purpose: We evaluated patient and treatment parameters correlated with development of temporal lobe radiation necrosis. Methods and Materials: This was a retrospective analysis of a cohort of 66 patients treated for skull base chordoma, chondrosarcoma, adenoid cystic carcinoma, or sinonasal malignancies between 2005 and 2012, who had at least 6 months of clinical and radiographic follow-up. The median radiation dose was 75.6 Gy (relative biological effectiveness [RBE]). Analyzed factors included gender, age, hypertension, diabetes, smoking status, use of chemotherapy, and the absolute dose:volume data for both the right and left temporal lobes, considered separately. A generalized estimating equation (GEE) regression analysis evaluatedmore » potential predictors of radiation necrosis, and the median effective concentration (EC50) model estimated dose–volume parameters associated with radiation necrosis. Results: Median follow-up time was 31 months (range 6-96 months) and was 34 months in patients who were alive. The Kaplan-Meier estimate of overall survival at 3 years was 84.9%. The 3-year estimate of any grade temporal lobe radiation necrosis was 12.4%, and for grade 2 or higher radiation necrosis was 5.7%. On multivariate GEE, only dose–volume relationships were associated with the risk of radiation necrosis. In the EC50 model, all dose levels from 10 to 70 Gy (RBE) were highly correlated with radiation necrosis, with a 15% 3-year risk of any-grade temporal lobe radiation necrosis when the absolute volume of a temporal lobe receiving 60 Gy (RBE) (aV60) exceeded 5.5 cm{sup 3}, or aV70 > 1.7 cm{sup 3}. Conclusions: Dose–volume parameters are highly correlated with the risk of developing temporal lobe radiation necrosis. In this study the risk of radiation necrosis increased sharply when the temporal lobe aV60 exceeded 5.5 cm{sup 3} or aV70 > 1.7 cm{sup 3}. Treatment planning goals should include constraints on the volume of temporal lobes receiving higher dose. The EC50 model provides suggested dose–volume temporal lobe constraints for conventionally fractionated high-dose skull base radiation therapy.« less

Evaluation of anterior third of superior sagittal sinus in normal population: Identifying the subgroup with dominant drainage.

PubMed

Sahoo, Sushanta K; Ghuman, Mandeep S; Salunke, Pravin; Vyas, Sameer; Bhar, Rahat; Khandelwal, N K

2016-01-01

The ligation and transection of anterior third of superior sagittal sinus (AT-SSS) is an important step to approach anterior skull base lesions. Some clinical studies have shown frontal lobe venous infarct following such surgical procedures questioning the safety of its ligation. We have studied the variations in venous drainage patterns to AT-SSS in the normal population using postcontrast magnetic resonance venogram (MRV). A novel scoring system to recognize the subgroup with dominant venous drainage from frontal lobes has been described. In this study, 60 three-dimensional contrast-enhanced (CE) MRVs were obtained from those cases being evaluated for a headache not harboring any intracranial mass lesion. The AT-SSS with all its draining veins was studied in detail. Morphology of individual veins such as length, caliber, tributaries, and angulation with AT-SSS was studied, and a numerical value of 0 or 1 was assigned for each of the above parameters. Summing up these scores derived from the individual cortical veins quantified the drainage of AT-SSS. There are 3-4 veins on either side draining to AT-SSS. Barely, 3% of the veins had > 3 tributaries. Only 6.6% of veins had a caliber >3 mm, and 16.5% drained at acute angles to AT-SSS. About 26% of the veins did cross at least half of the lateral frontal lobe. We found in 26 individuals the AT-SSS score was 0-2, in 22 it was 3-5 and, in only in 12 (20%) the score was 6 or more (dominant drainage). There are anatomical variations in venous drainage of frontal lobes into AT-SSS. Those with dominant drainage are likely to develop venous congestion and complications if sacrificed. It is possible to identify these individuals on the basis of venous drainage pattern as shown in CE-MRV.

Clinical utility of flumazenil-PET versus [18F]fluorodeoxyglucose-PET and MRI in refractory partial epilepsy. A prospective study in 100 patients.

PubMed

Ryvlin, P; Bouvard, S; Le Bars, D; De Lamérie, G; Grégoire, M C; Kahane, P; Froment, J C; Mauguière, F

1998-11-01

We assessed the clinical utility of [11C]flumazenil-PET (FMZ-PET) prospectively in 100 epileptic patients undergoing a pre-surgical evaluation, and defined the specific contribution of this neuro-imaging technique with respect to those of MRI and [18F]fluorodeoxyglucose-PET (FDG-PET). All patients benefited from a long term video-EEG monitoring, whereas an intracranial EEG investigation was performed in 40 cases. Most of our patients (73%) demonstrated a FMZ-PET abnormality; this hit rate was significantly higher in temporal lobe epilepsy (94%) than in other types of epilepsy (50%) (P < 0.001). Most FMZ-PET findings coexisted with a MRI abnormality (81%), including hippocampal atrophy (35%) and focal hypometabolism on FDG-PET (89%). The area of decreased FMZ binding was often smaller than that of glucose hypometabolism (48%) or larger than that of the MRI abnormality (28%). FMZ-PET did not prove superior to FDG-PET in assessing the extent of the ictal onset zone, as defined by intracranial EEG recordings. However, it provided useful data which were complementary to those of MRI and FDG-PET in three situations: (i) in temporal lobe epilepsy associated with MRI signs of hippocampal sclerosis, FMZ-PET abnormalities delineated the site of seizure onset precisely, whenever they were coextensive with FDG-PET abnormalities; (ii) in bi-temporal epilepsy, FMZ-PET helped to confirm the bilateral origin of seizures by showing a specific pattern of decreased FMZ binding in both temporal lobes in 33% of cases; (iii) in patients with a unilateral cryptogenic frontal lobe epilepsy, FMZ-PET provided further evidence of the side and site of seizure onset in 55% of cases. Thus, FMZ-PET deserves to be included in the pre-surgical evaluation of these specific categories of epileptic patients, representing approximately half of the population considered for epilepsy surgery.

Proteomic analysis and comparison of the biopsy and autopsy specimen of human brain temporal lobe.

PubMed

He, Sizhi; Wang, Qingsong; He, Jintang; Pu, Hai; Yang, Wei; Ji, Jianguo

2006-09-01

The proteomic study on human temporal lobe can help us to understand the physiological function of CNS in normal as well as in pathological state. Proteomic tools are potent for the assessment of protein stability post mortem. In this pilot study, the human temporal lobe biopsy specimen with chronic pharmacoresistant temporal lobe epilepsy (TLE) and autopsy specimen in control were separated by 2-DE. Using MALDI-TOF-MS and MS/MS, 375 protein spots were identified which were the products of 267 genes. Six down-regulated and 23 up-regulated protein spots in the autopsy specimen were ascertained after the gel image analysis with the ImageMaster software. A number of proteins that include neurotransmitter metabolic and glycolytic enzymes, cytoprotective proteins and cytoskeleton were found decreased while the precursor of apolipoprotein A-I increased in the TLE brain. We tried several methods to prepare the protein samples and found that DNase and RNase treatment, ultracentrifugation and Amersham clean-up kit purification can improve gel separation quality. This work optimized the sample preparation method and constructed a primary protein database of human temporal lobe and found some proteins with remarkable level change probably involved in the post-mortem process and chronic pharmacoresistant TLE pathogenesis.

Quantification of Hepcidin-related Iron Accumulation in the Rat Liver.

PubMed

Böser, Preethne; Mordashova, Yulia; Maasland, Mark; Trommer, Isabel; Lorenz, Helga; Hafner, Mathias; Seemann, Dietmar; Mueller, Bernhard K; Popp, Andreas

2016-02-01

Hepcidin was originally detected as a liver peptide with antimicrobial activity and it functions as a central regulator in the systemic iron metabolism. Consequently suppression of hepcidin leads to iron accumulation in the liver. AbbVie developed a monoclonal antibody ([mAb]; repulsive guidance molecule [RGMa/c] mAb) that downregulates hepcidin expression by influencing the RGMc/bone morphogenetic protein (BMP)/neogenin receptor complex and causes iron deposition in the liver. In a dose range finding study with RGMa/c mAb, rats were treated with different dose levels for a total of 4 weekly doses. The results of this morphometric analysis in the liver showed that iron accumulation is not homogenous between liver lobes and the left lateral lobe was the most responsive lobe in the rat. Quantitative hepcidin messenger RNA analysis showed that the left lateral lobe was the most responsive lobe showing hepcidin downregulation with increasing antibody dose. In addition, the morphometric analysis had higher sensitivity than the chemical iron extraction and quantification using a colorimetric assay. In conclusion, the Prussian blue stain in combination with semi-quantitative and quantitative morphometric analysis is the most reliable method to demonstrate iron accumulation in the liver compared to direct measurement of iron in unfixed tissue using a colorimetric assay. © The Author(s) 2016.

Airborne ultrasonic phased arrays using ferroelectrets: a new fabrication approach.

PubMed

Ealo, Joao L; Camacho, Jorge J; Fritsch, Carlos

2009-04-01

In this work, a novel procedure that considerably simplifies the fabrication process of ferroelectret-based multielement array transducers is proposed and evaluated. Also, the potential of ferroelectrets being used as active material for air-coupled ultrasonic transducer design is demonstrated. The new construction method of multi-element transducers introduces 2 distinctive improvements. First, active ferroelectret material is not discretized into elements, and second, the need of structuring upper and/or lower electrodes in advance of the permanent polarization of the film is removed. The aperture discretization and the mechanical connection are achieved in one step using a through-thickness conductive tape. To validate the procedure, 2 linear array prototypes of 32 elements, with a pitch of 3.43 mm and a wide usable frequency range from 30 to 300 kHz, were built and evaluated using a commercial phased-array system. A low crosstalk among elements, below -30 dB, was measured by interferometry. Likewise, a homogeneous response of the array elements, with a maximum deviation of +/-1.8 dB, was obtained. Acoustic beam steering measurements were accomplished at different deflection angles using a calibrated microphone. The ultrasonic beam parameters, namely, lateral resolution, side lobe level, grating lobes, and focus depth, were congruent with theory. Acoustic images of a single reflector were obtained using one of the array elements as the receiver. Resulting images are also in accordance with numerical simulation, demonstrating the feasibility of using these arrays in pulse-echo mode. The proposed procedure simplifies the manufacturing of multidimensional arrays with arbitrary shape elements and not uniformly distributed. Furthermore, this concept can be extended to nonflat arrays as long as the transducer substrate conforms to a developable surface.

The Synergistic Effect of Raloxifene, Fluoxetine, and Bromocriptine Protects Against Pilocarpine-Induced Status Epilepticus and Temporal Lobe Epilepsy.

PubMed

Pottoo, Faheem Hyder; Tabassum, Nahida; Javed, Md Noushad; Nigar, Shah; Rasheed, Rouqia; Khan, Ayash; Barkat, Md Abul; Alam, Md Sabir; Maqbool, Amir; Ansari, Mohammad Azam; Barreto, George E; Ashraf, Ghulam Md

2018-06-07

The present antiepileptic drugs pose several problems in the management of seizures owing to their meager neuroprotective potential, adverse effects on bone, detrimental effects on cognitive function, chronic toxicity, drug interactions, side effects including aggression, agitation, and irritability and sometimes exacerbation of seizures. We followed up progressive preclinical investigation in mice against pilocarpine (PILO)-induced status epilepticus (SE) and temporal lobe epilepsy (TLE). To determine the response of raloxifene (RF) (4 and 8 mg/kg), fluoxetine (FT) (14 and 22 mg/kg), bromocriptine (BC) (6 and 10 mg/kg), and their low-dose combinations, oral treatment was scheduled for 28 days followed by PILO (300 mg/kg, i.p). The response was stalked for intensive behavioral monitoring of convulsions, hippocampal neuropeptide Y (NPY), and oxidative stress discernment along with histomorphological studies. The resultant data confirmed the therapeutic potential of triple drug combination of raloxifene (4 mg/kg) with fluoxetine (14 mg/kg) and bromocriptine (6 mg/kg) compared to monotherapy with raloxifene (4 mg/kg), and bromocriptine (6 mg/kg) as otherwise monotherapy with fluoxetine (14 mg/kg) was ineffective to suppress convulsions; an effect better than sodium valproate (300 mg/kg), a standard AED, was validated. Most profoundly, PILO-induced compensatory increases in hippocampal NPY levels (20.01%), which was escalated (100%) with the triple drug combination. The same pattern of results was superseded for oxidative stress indices and neuronal damage. The results for the first time demonstrate the propitious role of triple drug combination in the management of SE and TLE. Therapeutically, this enhancing profile of drugs fosters a safer and more effective drug-combination regimen. Graphical abstract ᅟ.

Fermi/LAT observations of lobe-dominant radio galaxy 3C 207 and possible radiation region of γ-rays

NASA Astrophysics Data System (ADS)

Guo, Sheng-Chu; Zhang, Hai-Ming; Zhang, Jin; Liang, En-Wei

2018-06-01

3C 207 is a lobe-dominant radio galaxy with a one sided jet and bright knots, spanning a kpc-Mpc scale, which have been resolved in the radio, optical and X-ray bands. This target was confirmed as a γ-ray emitter with Fermi/LAT, but it is uncertain whether the γ-ray emission region is the core or knots due to the low spatial resolution of Fermi/LAT. We present an analysis of its Fermi/LAT data acquired during the past 9 years. Different from the radio and optical emission from the core, it is found that the γ-ray emission is steady without detection of flux variation at over a 2σ confidence level. This likely implies that the γ-ray emission is from its knots. We collect the radio, optical and X-ray data of knot-A, the closest knot from the core at 1.4″, and compile its spectral energy distribution (SED). Although the single-zone synchrotron+SSC+IC/CMB model that assumes knot-A is at rest can reproduce the SED in the radio-optical-X-ray band, the predicted γ-ray flux is lower than the LAT observations and the derived magnetic field strength deviates from the equipartition condition by 3 orders of magnitude. Assuming that knot-A is moving relativistically, its SED from radio to γ-ray bands would be represented well with the single-zone synchrotron+SSC+IC/CMB model under the equipartition condition. These results likely suggest that the γ-ray emission may be from knot-A via the IC/CMB process and the knot should have relativistical motion. The jet power derived from our model parameters is also roughly consistent with the kinetic power estimated with radio data.

Repetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp.

PubMed

Bharath, R D; Biswal, B B; Bhaskar, M V; Gohel, S; Jhunjhunwala, K; Panda, R; George, L; Gupta, A K; Pal, P K

2015-05-01

Writer's cramp (WC) is a focal task-specific dystonia of the hand which is increasingly being accepted as a network disorder. Non-invasive cortical stimulation using repetitive transcranial magnetic stimulation (rTMS) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsfMRI). Nineteen patients with right-sided WC and 20 matched healthy controls (HCs) were prospectively evaluated. All patients underwent a single session of rTMS and rsfMRI was acquired before (R1) and after (R2) rTMS. Seed-based functional connectivity analysis of several regions in the motor network was performed for HCs, R1 and R2 using SPM8 software. Thresholded (P < 0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After rTMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamus-right globus pallidus-right thalamus-right prefrontal lobe network loop. It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by rTMS probably act through subcortical and trans-hemispheric unaffected connections. Longitudinal studies with therapeutic rTMS will be required to ascertain whether such information could be used to select patients prior to rTMS therapy. © 2015 EAN.

Low noise 874 GHz receivers for the International Submillimetre Airborne Radiometer (ISMAR)

NASA Astrophysics Data System (ADS)

Hammar, A.; Sobis, P.; Drakinskiy, V.; Emrich, A.; Wadefalk, N.; Schleeh, J.; Stake, J.

2018-05-01

We report on the development of two 874 GHz receiver channels with orthogonal polarizations for the International Submillimetre Airborne Radiometer. A spline horn antenna and dielectric lens, a Schottky diode mixer circuit, and an intermediate frequency (IF) low noise amplifier circuit were integrated in the same metallic split block housing. This resulted in a receiver mean double sideband (DSB) noise temperature of 3300 K (minimum 2770 K, maximum 3400 K), achieved at an operation temperature of 40 °C and across a 10 GHz wide IF band. A minimum DSB noise temperature of 2260 K at 20 °C was measured without the lens. Three different dielectric lens materials were tested and compared with respect to the radiation pattern and noise temperature. All three lenses were compliant in terms of radiation pattern, but one of the materials led to a reduction in noise temperature of approximately 200 K compared to the others. The loss in this lens was estimated to be 0.42 dB. The local oscillator chains have a power consumption of 24 W and consist of custom-designed Schottky diode quadruplers (5% power efficiency in operation, 8%-9% peak), commercial heterostructure barrier varactor (HBV) triplers, and power amplifiers that are pumped by using a common dielectric resonator oscillator at 36.43 GHz. Measurements of the radiation pattern showed a symmetric main beam lobe with full width half maximum <5° and side lobe levels below -20 dB. Return loss of a prototype of the spline horn and lens was measured using a network analyzer and frequency extenders to 750-1100 GHz. Time-domain analysis of the reflection coefficients shows that the reflections are below -25 dB and are dominated by the external waveguide interface.

Cold-flow acoustic evaluation of a small scale, divergent, lobed nozzle for supersonic jet noise suppression

NASA Technical Reports Server (NTRS)

Huff, R. G.; Groesbeck, D. E.

1975-01-01

A supersonic jet noise suppressor was tested with cold flow for acoustic and thrust characteristics at nozzle- to atmospheric-pressure ratios of 1.5 to 4.0. Jet noise suppression and spectral characteristics of the divergent, lobed, suppressor (DLS) nozzle with and without an ejector are presented. Suppression was obtained at nozzle pressure ratios of 2.5 to 4.0. The largest, maximum-lobe, sound pressure level suppression with a hard-wall ejector was 14.6 decibels at a nozzle pressure ratio of 3.5. The thrust loss was 2 percent. In general, low-frequency jet noise was suppressed, leaving higher frequencies essentially unchanged. Without the ejector the nozzle showed a thrust loss of 11 percent together with slightly poorer noise suppression.

Tracals Evaluation Report. Communications Initial Evaluation Report, Keesler AFB, Mississippi, 10-15 March 1980.

DTIC Science & Technology

1980-05-15

antenna platform . Moving 320.1 MHz from antenna B to antenna G at the GATR site would reduce the lobing structure for this frequency and provide more...uniform coverage. Providing increased antenna separation by spacing only four antennas along the east and west sides of the antenna platform would also...E~ 0 / C4 Is- / It /;/ ,iK 4 I’~ / / ~;~:;’/if ~4Co j0 I i0 - - - -L C4- j Wix L -,> 3-4 = x GZ li i Iz 3 0 Cc -, A25-4 L Attachment 25 ooLa I.- 0

Beam steering performance of compressed Luneburg lens based on transformation optics

NASA Astrophysics Data System (ADS)

Gao, Ju; Wang, Cong; Zhang, Kuang; Hao, Yang; Wu, Qun

2018-06-01

In this paper, two types of compressed Luneburg lenses based on transformation optics are investigated and simulated using two different sources, namely, waveguides and dipoles, which represent plane and spherical wave sources, respectively. We determined that the largest beam steering angle and the related feed point are intrinsic characteristics of a certain type of compressed Luneburg lens, and that the optimized distance between the feed and lens, gain enhancement, and side-lobe suppression are related to the type of source. Based on our results, we anticipate that these lenses will prove useful in various future antenna applications.

Study of the spectral bandwidth of a double-pass acousto-optic system [Invited].

PubMed

Champagne, Justine; Kastelik, Jean-Claude; Dupont, Samuel; Gazalet, Joseph

2018-04-01

Acousto-optic tunable filters are known as efficient instruments for spectral and spatial filtering of light. In this paper, we analyze the bandwidth dependence of a double-pass filter. The interaction geometry chosen allows the simultaneous diffraction of the ordinary and the extraordinary optical modes by a single ultrasonic frequency. We present the main parameters of a custom device (design, optical range, driving frequency) and experimental results concerning the angular deviation of the beams including the effect of optical birefringence. The spectral resolution and the side lobes' significance are discussed. Spectral bandwidth of such a system is analyzed.

Weak network efficiency in young children with Autism Spectrum Disorder: Evidence from a functional near-infrared spectroscopy study.

PubMed

Li, Yanwei; Yu, Dongchuan

2016-10-01

Functional near infrared spectroscopy (fNIRS) is particularly suited for the young population and ecological measurement. However, thus far, not enough effort has been given to the clinical diagnosis of young children with Autism Spectrum Disorder (ASD) by using fNIRS. The current study provided some insights into the quantitative analysis of functional networks in young children (ages 4.8-8.0years old) with and without ASD and, in particular, investigated the network efficiency and lobe-level connectivity of their functional networks while watching a cartoon. The main results included that: (i) Weak network efficiency was observed in young children with ASD, even for a wide range of threshold for the binarization of functional networks; (ii) A maximum classification accuracy rate of 83.3% was obtained for all participants by using the k-means clustering method with network efficiencies as the feature parameters; and (iii) Weak lobe-level inter-region connections were uncovered in the right prefrontal cortex, including its linkages with the left prefrontal cortex and the bilateral temporal cortex. Such results indicate that the right prefrontal cortex might make a major contribution to the psychopathology of young children with ASD at the functional network architecture level, and at the functional lobe-connectivity level, respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

Explicit memory and implicit memory in occipital lobe stroke patients.

PubMed

Gong, Liang; Wang, JiHua; Feng, Lei; Wang, MeiHong; Li, Xiu; Hu, JiaYun; Wang, Kai

2015-03-01

Occipital stroke patients mainly showed cortical blindness and unilateral vision loss; memory is generally reserved. Recent reports from neuroimaging show the occipital lobe may be involved in the processing of implicit memory (IM), especially the perception type of IM processing. In this study, we explored the explicit memory (EM) and IM damage in occipital lobe stroke patients. A total of 25 occipital strokes and 29 years of age, educational level equivalent healthy controls (HCs), evaluated by using immediate recall, delayed recall, recognition for EM tasks, picture identification, and category exemplar generation for IM tasks. There was no significant difference between occipital stroke patients and HCs in EM tasks and category exemplar generation task. In the picture identification task, occipital lobe stroke group score was poorer than HC group, the results were statistically significant, but in the pictures identify rate, occipital stroke patients and normal control group had no significant difference. The occipital stroke patients may have IM damage, primarily damage the perception type of IM priming effects, which was unrelated with their cortical blindness. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Effects of Passive Fuel-Air Mixing Control on Burner Emissions Via Lobed Fuel Injectors

NASA Technical Reports Server (NTRS)

Mitchell, M. G.; Smith, O. I.; Karagozian, A. R.

1999-01-01

The present experimental study examines the effects of differing levels of passive fuel-air premixing on flame structures and their associated NO(x) and CO emissions. Four alternative fuel injector geometries were explored, three of which have lobed shapes. These lobed injectors mix fuel and air and strain species inter-faces to differing extents due to streamwise vorticity generation, thus creating different local or core equivalence ratios within flow regions upstream of flame ignition and stabilization. Prior experimental studies of two of these lobed injector flowfields focused on non-reactive mixing characteristics and emissions measurements for the case where air speeds were matched above and below the fuel injector, effectively generating stronger streamwise vorticity than spanwise vorticity. The present studies examine the effects of airstream mismatch (and hence additional spanwise vorticity generation), effects of confinement of the crossflow to reduce the local equivalence ratio, and the effects of altering the geometry and position of the flameholders. NO(x) and CO emissions as well as planar laser-induced fluorescence imaging (PLIF) of seeded acetone are used to characterize injector performance and reactive flow evolution.

Decreased astroglial monocarboxylate transporter 4 expression in temporal lobe epilepsy.

PubMed

Liu, Bei; Niu, Le; Shen, Ming-Zhi; Gao, Lei; Wang, Chao; Li, Jie; Song, Li-Jia; Tao, Ye; Meng, Qiang; Yang, Qian-Li; Gao, Guo-Dong; Zhang, Hua

2014-10-01

Efflux of monocaroxylates like lactate, pyruvate, and ketone bodies from astrocytes through monocarboxylate transporter 4 (MCT4) supplies the local neuron population with metabolic intermediates to meet energy requirements under conditions of increased demand. Disruption of this astroglial-neuron metabolic coupling pathway may contribute to epileptogenesis. We measured MCT4 expression in temporal lobe epileptic foci excised from patients with intractable epilepsy and in rats injected with pilocarpine, an animal model of temporal lobe epilepsy (TLE). Cortical MCT4 expression levels were significantly lower in TLE patients compared with controls, due at least partially to MCT4 promoter methylation. Expression of MCT4 also decreased progressively in pilocarpine-treated rats from 12 h to 14 days post-administration. Underexpression of MCT4 in cultured astrocytes induced by a short hairpin RNA promoted apoptosis. Knockdown of astrocyte MCT4 also suppressed excitatory amino acid transporter 1 (EAAT1) expression. Reduced MCT4 and EAAT1 expression by astrocytes may lead to neuronal hyperexcitability and epileptogenesis in the temporal lobe by reducing the supply of metabolic intermediates and by allowing accumulation of extracellular glutamate.

Sensitivity to musical structure in the human brain

PubMed Central

McDermott, Josh H.; Norman-Haignere, Sam; Kanwisher, Nancy

2012-01-01

Evidence from brain-damaged patients suggests that regions in the temporal lobes, distinct from those engaged in lower-level auditory analysis, process the pitch and rhythmic structure in music. In contrast, neuroimaging studies targeting the representation of music structure have primarily implicated regions in the inferior frontal cortices. Combining individual-subject fMRI analyses with a scrambling method that manipulated musical structure, we provide evidence of brain regions sensitive to musical structure bilaterally in the temporal lobes, thus reconciling the neuroimaging and patient findings. We further show that these regions are sensitive to the scrambling of both pitch and rhythmic structure but are insensitive to high-level linguistic structure. Our results suggest the existence of brain regions with representations of musical structure that are distinct from high-level linguistic representations and lower-level acoustic representations. These regions provide targets for future research investigating possible neural specialization for music or its associated mental processes. PMID:23019005

Comparative factor analysis of the effect of postoperative peripheral parenteral nutrition on recovery of right lobe liver donors.

PubMed

Hsieh, Chia-En; Lin, Kuo-Hua; Lin, Chia-Cheng; Hwu, Yueh-Juen; Lin, Ping-Yi; Lin, Hui-Chuan; Ko, Chih-Jan; Wang, Su-Han; Chen, Yao-Li

2015-04-01

Intensive nutritional support can reduce the catabolic response, improve protein synthesis, and promote liver regeneration. This study examined whether postoperative peripheral parenteral nutrition may improve recovery and reduce the length of hospital stay in right lobe liver donors. In this retrospective study, we enrolled liver donors with residual liver volume < 50%. Donors were classified into 2 groups: donors who received (n = 44) or did not receive (n = 40) postoperative peripheral parenteral nutrition. Liver function tests included alanine aminotransferase and total bilirubin levels, and postoperative complications included pleural effusion, atelectasis, and wound complications. Hospital length of stay was included as a potential risk factor for the evaluation of the effect of postoperative peripheral parenteral nutrition on recovery of right lobe liver donors. Male sex (β, 22.04; 95% confidence interval: 6.22 - 37.86) was a significant predictor of changes in postoperative alanine aminotransferase level. Male sex (β, 0.045; 95% confidence interval: 0.16 - 37.86) and receipt of peripheral parenteral nutrition (β, -0.045; 95% confidence interval: -0.72 - 0.17) were significant predictors of changes in total bilirubin level. Postoperative atelectasis (P < .001), pleural effusion (P < .011), and total complications (P = .015) had significantly lower incidence in the peripheral parenteral nutrition than control group. Multivariate logistic regression showed that recipients of peripheral parenteral nutrition (odds ratio, 0.161; 95% confidence interval: 0.043 - 0.598) and age (odds ratio, 0.870; 95% confidence interval: 0.782 - 0.968) were significant preoperative risk factors for postoperative complications. Postoperative peripheral parenteral nutrition is associated with a lower incidence of pleural effusion and atelectasis, a more rapid recovery of hyperbilirubinemia, and shorter length of stay in right lobe liver donors.

Differences in the neural correlates of frontal lobe tests.

PubMed

Matsuoka, Teruyuki; Kato, Yuka; Imai, Ayu; Fujimoto, Hiroshi; Shibata, Keisuke; Nakamura, Kaeko; Yamada, Kei; Narumoto, Jin

2018-01-01

The Executive Interview (EXIT25), the executive clock-drawing task (CLOX1), and the Frontal Assessment Battery (FAB) are used to assess executive function at the bedside. These tests assess distinct psychometric properties. The aim of this study was to examine differences in the neural correlates of the EXIT25, CLOX1, and FAB based on magnetic resonance imaging. Fifty-eight subjects (30 with Alzheimer's disease, 10 with mild cognitive impairment, and 18 healthy controls) participated in this study. Multiple regression analyses were performed to examine the brain regions correlated with the EXIT25, CLOX1, and FAB scores. Age, gender, and years of education were included as covariates. Statistical thresholds were set to uncorrected P-values of 0.001 at the voxel level and 0.05 at the cluster level. The EXIT25 score correlated inversely with the regional grey matter volume in the left lateral frontal lobe (Brodmann areas 6, 9, 44, and 45). The CLOX1 score correlated positively with the regional grey matter volume in the right orbitofrontal cortex (Brodmann area 11) and the left supramarginal gyrus (Brodmann area 40). The FAB score correlated positively with the regional grey matter volume in the right precentral gyrus (Brodmann area 6). The left lateral frontal lobe (Brodmann area 9) and the right lateral frontal lobe (Brodmann area 46) were identified as common brain regions that showed association with EXIT25, CLOX1, and FAB based only a voxel-level threshold. The results of this study suggest that the EXIT25, CLOX1, and FAB may be associated with the distinct neural correlates of the frontal cortex. © 2018 Japanese Psychogeriatric Society.

Dopamine-regulated adrenocorticotropic hormone secretion in lactating rats: functional plasticity of melanotropes.

PubMed

Oláh, Márk; Fehér, Pálma; Ihm, Zsófia; Bácskay, Ildikó; Kiss, Timea; Freeman, Marc E; Nagy, Gyorgy M; Vecsernyés, Miklós

2009-01-01

Pro-opiomelanocortin (POMC) is processed to adrenocorticotropic hormone (ACTH) and beta-lipotropin in corticotropes of the anterior lobe, and to alpha-melanocyte-stimulating hormone (alpha-MSH) and beta-endorphin in melanotropes of the intermediate lobe (IL) of the pituitary gland. While ACTH secretion is predominantly under the stimulatory influence of the hypothalamic factors, hormone secretion of the IL is tonically inhibited by neuroendocrine dopamine (NEDA) neurons. Lobe-specific POMC processing is not absolute. For example, D(2) type DA receptor (D2R)-deficient mice have elevated plasma ACTH levels, although it is known that corticotropes do not express D2R(s). Moreover, observations that suckling does not influence alpha-MSH release, while it induces an increase in plasma ACTH is unexplained. The aim of the present study was to investigate the involvement of the NEDA system in the regulation of ACTH secretion and the participation of the IL in ACTH production in lactating rats. Untreated and estradiol (E(2))-substituted ovariectomized (OVX) females were also studied. The concentration of ACTH in the IL was higher in lactating rats than in OVX rats, while the opposite change in alpha-MSH level of the IL was observed. DA levels in the IL and the neural lobe were lower in lactating rats than in OVX rats. Suckling-induced ACTH response was eliminated by pretreatment with the DA receptor agonist, bromocriptine (BRC). Inhibition of DA biosynthesis by alpha-methyl-p-tyrosine (alphaMpT) and blockade of D2R by domperidone (DOM) elevated plasma ACTH levels, but did not influence plasma alpha-MSH levels in lactating rats. The same drugs had opposite effects in OVX and OVX + E(2) animals. In lactating mothers, BRC was able to block ACTH responses induced by both alphaMpT and DOM. Surgical denervation of the IL elevated basal plasma levels of ACTH. Taken together, these data indicate that melanotropes synthesize ACTH during lactation and its release from these cells is regulated by NEDA neurons. Copyright 2009 S. Karger AG, Basel.

Dopamine-Regulated Adrenocorticotropic Hormone Secretion in Lactating Rats: Functional Plasticity of Melanotropes

PubMed Central

Oláh, Márk; Fehér, Pálma; Ihm, Zsófia; Bácskay, Ildikó; Kiss, Timea; Freeman, Marc E.; Nagy, György M.; Vecsernyés, Miklós

2009-01-01

Pro-opiomelanocortin (POMC) is processed to adrenocorticotropic hormone (ACTH) and β-lipotropin in corticotropes of the anterior lobe, and to α-melanocyte-stimulating hormone (α-MSH) and β-endorphin in melanotropes of the intermediate lobe (IL) of the pituitary gland. While ACTH secretion is predominantly under the stimulatory influence of the hypothalamic factors, hormone secretion of the IL is tonically inhibited by neuroendocrine dopamine (NEDA) neurons. Lobe-specific POMC processing is not absolute. For example, D2 type DA receptor (D2R)-deficient mice have elevated plasma ACTH levels, although it is known that corticotropes do not express D2R(s). Moreover, observations that suckling does not influence α-MSH release, while it induces an increase in plasma ACTH is unexplained. The aim of the present study was to investigate the involvement of the NEDA system in the regulation of ACTH secretion and the participation of the IL in ACTH production in lactating rats. Untreated and estradiol (E2)-substituted ovariectomized (OVX) females were also studied. The concentration of ACTH in the IL was higher in lactating rats than in OVX rats, while the opposite change in α-MSH level of the IL was observed. DA levels in the IL and the neural lobe were lower in lactating rats than in OVX rats. Suckling-induced ACTH response was eliminated by pretreatment with the DA receptor agonist, bromocriptine (BRC). Inhibition of DA biosynthesis by α-methyl-p-tyrosine (αMpT) and blockade of D2R by domperidone (DOM) elevated plasma ACTH levels, but did not influence plasma α-MSH levels in lactating rats. The same drugs had opposite effects in OVX and OVX + E2 animals. In lactating mothers, BRC was able to block ACTH responses induced by both αMpT and DOM. Surgical denervation of the IL elevated basal plasma levels of ACTH. Taken together, these data indicate that melanotropes synthesize ACTH during lactation and its release from these cells is regulated by NEDA neurons. PMID:19641299

Identification of Amnestic Mild Cognitive Impairment Using Multi-Modal Brain Features: A Combined Structural MRI and Diffusion Tensor Imaging Study.

PubMed

Xie, Yunyan; Cui, Zaixu; Zhang, Zhongmin; Sun, Yu; Sheng, Can; Li, Kuncheng; Gong, Gaolang; Han, Ying; Jia, Jianping

2015-01-01

Identifying amnestic mild cognitive impairment (aMCI) is of great clinical importance because aMCI is a putative prodromal stage of Alzheimer's disease. The present study aimed to explore the feasibility of accurately identifying aMCI with a magnetic resonance imaging (MRI) biomarker. We integrated measures of both gray matter (GM) abnormalities derived from structural MRI and white matter (WM) alterations acquired from diffusion tensor imaging at the voxel level across the entire brain. In particular, multi-modal brain features, including GM volume, WM fractional anisotropy, and mean diffusivity, were extracted from a relatively large sample of 64 Han Chinese aMCI patients and 64 matched controls. Then, support vector machine classifiers for GM volume, FA, and MD were fused to distinguish the aMCI patients from the controls. The fused classifier was evaluated with the leave-one-out and the 10-fold cross-validations, and the classifier had an accuracy of 83.59% and an area under the curve of 0.862. The most discriminative regions of GM were mainly located in the medial temporal lobe, temporal lobe, precuneus, cingulate gyrus, parietal lobe, and frontal lobe, whereas the most discriminative regions of WM were mainly located in the corpus callosum, cingulum, corona radiata, frontal lobe, and parietal lobe. Our findings suggest that aMCI is characterized by a distributed pattern of GM abnormalities and WM alterations that represent discriminative power and reflect relevant pathological changes in the brain, and these changes further highlight the advantage of multi-modal feature integration for identifying aMCI.

Influence of parameter settings in voxel-based morphometry 8. Using DARTEL and region-of-interest on reproducibility in gray matter volumetry.

PubMed

Goto, M; Abe, O; Aoki, S; Hayashi, N; Miyati, T; Takao, H; Matsuda, H; Yamashita, F; Iwatsubo, T; Mori, H; Kunimatsu, A; Ino, K; Yano, K; Ohtomo, K

2015-01-01

To investigate whether reproducibility of gray matter volumetry is influenced by parameter settings for VBM 8 using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) with region-of-interest (ROI) analyses. We prepared three-dimensional T1-weighted magnetic resonance images (3D-T1WIs) of 21 healthy subjects. All subjects were imaged with each of five MRI systems. Voxel-based morphometry 8 (VBM 8) and WFU PickAtlas software were used for gray matter volumetry. The bilateral ROI labels used were those provided as default settings with the software: Frontal Lobe, Hippocampus, Occipital Lobe, Orbital Gyrus, Parietal Lobe, Putamen, and Temporal Lobe. All 3D-T1WIs were segmented to gray matter with six parameters of VBM 8, with each parameter having between three and eight selectable levels. Reproducibility was evaluated as the standard deviation (mm³) of measured values for the five MRI systems. Reproducibility was influenced by 'Bias regularization (BiasR)', 'Bias FWHM', and 'De-noising filter' settings, but not by 'MRF weighting', 'Sampling distance', or 'Warping regularization' settings. Reproducibility in BiasR was influenced by ROI. Superior reproducibility was observed in Frontal Lobe with the BiasR1 setting, and in Hippocampus, Parietal Lobe, and Putamen with the BiasR3*, BiasR1, and BiasR5 settings, respectively. Reproducibility of gray matter volumetry was influenced by parameter settings in VBM 8 using DARTEL and ROI. In multi-center studies, the use of appropriate settings in VBM 8 with DARTEL results in reduced scanner effect.

Ionospheric control of the dawn-dusk asymmetry of the Mars magnetotail current sheet

NASA Astrophysics Data System (ADS)

Liemohn, Michael W.; Xu, Shaosui; Dong, Chuanfei; Bougher, Stephen W.; Johnson, Blake C.; Ilie, Raluca; De Zeeuw, Darren L.

2017-06-01

This study investigates the role of solar EUV intensity at controlling the location of the Mars magnetotail current sheet and the structure of the lobes. Four simulation results are examined from a multifluid magnetohydrodynamic model. The solar wind and interplanetary magnetic field (IMF) conditions are held constant, and the Mars crustal field sources are omitted from the simulation configuration. This isolates the influence of solar EUV. It is found that solar maximum conditions, regardless of season, result in a Venus-like tail configuration with the current sheet shifted to the -Y (dawnside) direction. Solar minimum conditions result in a flipped tail configuration with the current sheet shifted to the +Y (duskside) direction. The lobes follow this pattern, with the current sheet shifting away from the larger lobe with the higher magnetic field magnitude. The physical process responsible for this solar EUV control of the magnetotail is the magnetization of the dayside ionosphere. During solar maximum, the ionosphere is relatively strong and the draped IMF field lines quickly slip past Mars. At solar minimum, the weaker ionosphere allows the draped IMF to move closer to the planet. These lower altitudes of the closest approach of the field line to Mars greatly hinder the day-to-night flow of magnetic flux. This results in a buildup of magnetic flux in the dawnside lobe as the S-shaped topology on that side of the magnetosheath extends farther downtail. The study demonstrates that the Mars dayside ionosphere exerts significant control over the nightside induced magnetosphere of that planet.