Circadian rhythm disturbance after radiotherapy for brain tumor in infantile period; Clinical effect of L-thyroxine and vitamin B[sub 12

Energy Technology Data Exchange (ETDEWEB)

Kubota, Masaya; Shinozaki, Masako (Metropolitan Medical Center for the Severely Handicapped, Fuchu, Tokyo (Japan)); Sasaki, Hideo

1993-08-01

We report a 19-year-old man suffering from circadian sleep-wake (S-W) rhythm disturbance after total tumor resection and whole brain irradiation. The patient was diagnosed as having astrocytoma in the right temporal lobe by CT scan and angiography at the age of 6 months. After total tumor resection and whole brain irradiation ([sup 60]Co 60 Gy), he showed profound psychomotor retardation, endoclinologic dysfunction including hypothyroidism and growth hormone deficiency, and S-W rhythm disturbance. At age 19, brain MRI revealed asymmetrical low intensity in the hypothalamic region. On endoclinological examination panhypopituitarism due to primary hypothalamic lesion was evident. His S-W rhythm was disturbed; i.e., sleep periods were dispersedly distributed throughout 24 hours. He showed a lethargic tendency in the daytime. All-day polysomnography revealed abnormal sleep structure such as the absence of sleep spindle and hump, peripheral apnea, snoring and low oxygen saturation. After L-thyroxine supplementation his daily activity improved gradually. The decrease in short time sleep and tendency of a free-running rhythm were observed and oxygen saturation improved remarkably. Peripheral apnea and snoring disappeared. This wakening effect of L-thyroxine administration may be due to improvement of hypothyroidism symptom such as myxoedematous pharynx. It also seems related to the alteration of the central S-W rhythm regulation, because free-running rhythm appeared after L-thyroxine administration. Vitamin B[sub 12] (VB[sub 12]), which has been reported to be effective for S-W rhythm disorders, was not effective for our patient's free-running rhythm. Compared with the patients responding to VB[sub 12], our patient's organic brain damage was more evident radiologically and endoclinologically. Following the hypothesis that VB[sub 12] has a potential to reinforce the entrainment of circadian rhythm, our patient's organic brain damage may include entrainment

Developmental disturbances of the fetal brain in guinea-pigs caused by methylmercury

Energy Technology Data Exchange (ETDEWEB)

Inouye, Minoru; Kajiwara, Yuji

1988-08-01

Pregnant guinea-pigs of Hartley strain were orally administered methylmercuric chloride once at a dose of 7.5 mg Hg/animal (weighing 500-800 g) on one of days 21, 28, 35, 42 or 49 (3-7 weeks) of gestation. They were killed on day 63 (9 weeks) and their fetuses were removed. Both maternal and fetal blood, brain, liver and kidney, and fetal hair, urine, gastric content and amniotic fluid as well, were sampled for mercury analysis. The fetal brains were also examined pathologically. The maternal kidney contained mercury at a high concentration but the fetal kidney did not. The mercury concentration was strikingly high in the fetal hair, but fairly low in the urine, gastric contents and amniotic fluid. Mercury distributed unevenly in various brain regions of both dams and fetuses after treatment at 6 and 7 weeks of pregnancy (3 and 2 weeks before sampling). The concentration was high in the neopallium and archipallium, followed by the paleopallium, diencephalon and mesencephalon, but low in the rhombencephalon, including cerebellum. Mercury contents were relatively low and distributed almost evenly in various brain regions of both the dams and fetuses following treatment at 3, 4 and 5 weeks of pregnancy. Morphologically, the fetal brains were disturbed in the development following treatment at 3, 4 and 5 weeks of pregnancy. The cerebral cortex was thinned, the nucleus caudatus putamen and the hippocampal formation were reduced in size, and the lateral ventricles were dilated. However, the histological architecture of the cerebral cortex was not strikingly maldeveloped; only a slight disarrangement of the cellular alignment was noted. Following treatment at 6 and 7 weeks of pregnancy, focal degeneration of the neuronal cells was observed in the fetal neocortex; the severe cases showed spongy degeneration and dysgenetic hydrocephalus.

Neuroendocrine Disturbances One to Five or More Years after Traumatic Brain Injury and Aneurysmal Subarachnoid Hemorrhage: Data from the German Database on Hypopituitarism.

Science.gov (United States)

Krewer, Carmen; Schneider, Manfred; Schneider, Harald Jörn; Kreitschmann-Andermahr, Ilonka; Buchfelder, Michael; Faust, Michael; Berg, Christian; Wallaschofski, Henri; Renner, Caroline; Uhl, Eberhard; Koenig, Eberhard; Jordan, Martina; Stalla, Günter Karl; Kopczak, Anna

2016-08-15

Neuroendocrine disturbances are common after traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH), but only a few data exist on long-term anterior pituitary deficiencies after brain injury. We present data from the Structured Data Assessment of Hypopituitarism after TBI and SAH, a multi-center study including 1242 patients. We studied a subgroup of 351 patients, who had sustained a TBI (245) or SAH (106) at least 1 year before endocrine assessment (range 1-55 years) in a separate analysis. The highest prevalence of neuroendocrine disorders was observed 1-2 years post-injury, and it decreased over time only to show another maximum in the long-term phase in patients with brain injury occurring ≥5 years prior to assessment. Gonadotropic and somatotropic insufficiencies were most common. In the subgroup from 1 to 2 years after brain injury (n = 126), gonadotropic insufficiency was the most common hormonal disturbance (19%, 12/63 men) followed by somatotropic insufficiency (11.5%, 7/61), corticotropic insufficiency (9.2%, 11/119), and thyrotropic insufficiency (3.3%, 4/122). In patients observed ≥ 5 years after brain injury, the prevalence of somatotropic insufficiency increased over time to 24.1%, whereas corticotropic and thyrotrophic insufficiency became less frequent (2.5% and 0%, respectively). The prevalence differed regarding the diagnostic criteria (laboratory values vs. physician`s diagnosis vs. stimulation tests). Our data showed that neuroendocrine disturbances are frequent even years after TBI or SAH, in a cohort of patients who are still on medical treatment.

Modeling dynamic behavior of superconducting maglev systems under external disturbances

Science.gov (United States)

Huang, Chen-Guang; Xue, Cun; Yong, Hua-Dong; Zhou, You-He

2017-08-01

For a maglev system, vertical and lateral displacements of the levitation body may simultaneously occur under external disturbances, which often results in changes in the levitation and guidance forces and even causes some serious malfunctions. To fully understand the effect of external disturbances on the levitation performance, in this work, we build a two-dimensional numerical model on the basis of Newton's second law of motion and a mathematical formulation derived from magnetoquasistatic Maxwell's equations together with a nonlinear constitutive relation between the electric field and the current density. By using this model, we present an analysis of dynamic behavior for two typical maglev systems consisting of an infinitely long superconductor and a guideway of different arrangements of infinitely long parallel permanent magnets. The results show that during the vertical movement, the levitation force is closely associated with the flux motion and the moving velocity of the superconductor. After being disturbed at the working position, the superconductor has a disturbance-induced initial velocity and then starts to periodically vibrate in both lateral and vertical directions. Meanwhile, the lateral and vertical vibration centers gradually drift along their vibration directions. The larger the initial velocity, the faster their vibration centers drift. However, the vertical drift of the vertical vibration center seems to be independent of the direction of the initial velocity. In addition, due to the lateral and vertical drifts, the equilibrium position of the superconductor in the maglev systems is not a space point but a continuous range.

Forest disturbances under climate change

Czech Academy of Sciences Publication Activity Database

Seidl, R.; Thom, D.; Kautz, M.; Martin-Benito, D.; Peltoniemi, M.; Vacchiano, G.; Wild, Jan; Ascoli, D.; Petr, M.; Honkaniemi, J.; Lexer, M. J.; Trotsiuk, V.; Mairota, P.; Svoboda, M.; Fabrika, M.; Nagel, T.A.; Reyer, C. P. O.

2017-01-01

Roč. 7, č. 6 (2017), s. 395-402 ISSN 1758-678X R&D Projects: GA MŠk(CZ) LD15158 Institutional support: RVO:67985939 Keywords : climate change * disturbance * forest Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 19.304, year: 2016

A Coordinating Strategy for Biofuel Supply Chain under Disturbance Using Revenue Sharing Contract Approach

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Nana Geng

2018-05-01

Full Text Available Biofuel is considered to be an important alternative energy in the future transportation. Its development is supported by the rest of the world. However, biofuel industry development is still very slow. From the previous research it is known that the supply chain coordination and other problems need to be solved to promote the supply chain ability. This paper studies biodiesel supply chain coordination problem from the view of disturbance management. It gives a disturbed coordination strategy which contains the optimal order quantity and the contract parameters. This paper has then verified the disturbed coordination strategy through using the actual data of Jiangsu Yueda Kate New Energy Co. Ltd. The result shows that when the market demand and the recovery cost are simultaneously disturbed, the coordination can make the biodiesel supply chain robust and the new strategy under the revenue sharing contract is better than the original one.

Whole-brain structural topology in adult attention-deficit/hyperactivity disorder: Preserved global - disturbed local network organization.

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Sidlauskaite, Justina; Caeyenberghs, Karen; Sonuga-Barke, Edmund; Roeyers, Herbert; Wiersema, Jan R

2015-01-01

Prior studies demonstrate altered organization of functional brain networks in attention-deficit/hyperactivity disorder (ADHD). However, the structural underpinnings of these functional disturbances are poorly understood. In the current study, we applied a graph-theoretic approach to whole-brain diffusion magnetic resonance imaging data to investigate the organization of structural brain networks in adults with ADHD and unaffected controls using deterministic fiber tractography. Groups did not differ in terms of global network metrics - small-worldness, global efficiency and clustering coefficient. However, there were widespread ADHD-related effects at the nodal level in relation to local efficiency and clustering. The affected nodes included superior occipital, supramarginal, superior temporal, inferior parietal, angular and inferior frontal gyri, as well as putamen, thalamus and posterior cerebellum. Lower local efficiency of left superior temporal and supramarginal gyri was associated with higher ADHD symptom scores. Also greater local clustering of right putamen and lower local clustering of left supramarginal gyrus correlated with ADHD symptom severity. Overall, the findings indicate preserved global but altered local network organization in adult ADHD implicating regions underpinning putative ADHD-related neuropsychological deficits.

Study of landscape change under forest harvesting and climate warming-induced fire disturbance

Science.gov (United States)

S. He Hong; David J. Mladenoff; Eric J. Gustafson

2002-01-01

We examined tree species responses under forest harvesting and an increased fire disturbance scenario due to climate warming in northern Wisconsin where northern hardwood and boreal forests are currently predominant. Individual species response at the ecosystem scale was simulated with a gap model, which integrates soil, climate and species data, stratified by...

Biofuel production system with operation flexibility: Evaluation of economic and environmental performance under external disturbance

Science.gov (United States)

Kou, Nannan

Biomass derived liquid hydrocarbon fuel (biofuel) has been accepted as an effective way to mitigate the reliance on petroleum and reduce the greenhouse gas emissions. An increasing demand for second generation biofuels, produced from ligno-cellulosic feedstock and compatible with current infrastructure and vehicle technologies, addresses two major challenges faced by the current US transportation sector: energy security and global warming. However, biofuel production is subject to internal disturbances (feedstock supply and commodity market) and external factors (energy market). The biofuel industry has also heavily relied on government subsidy during the early development stages. In this dissertation, I investigate how to improve the economic and environmental performance of biorefineries (and biofuel plant), as well as enhance its survivability under the external disturbances. Three types of disturbance are considered: (1) energy market fluctuation, (2) subsidy policy uncertainty, and (3) extreme weather conditions. All three factors are basically volatile, dynamic, and even unpredictable, which makes them difficult to model and have been largely ignored to date. Instead, biofuel industry and biofuel research are intensively focused on improving feedstock conversion efficiency and capital cost efficiency while assuming these advancements alone will successfully generate higher profit and thus foster the biofuel industry. The collapse of the largest corn ethanol biofuel company, Verasun Energy, in 2008 calls into question this efficiency-driven approach. A detailed analysis has revealed that although the corn ethanol plants operated by Verasun adopted the more efficient (i.e. higher ethanol yield per bushel of corn and lower capital cost) dry-mill technology, they could not maintain a fair profit margin under fluctuating market condition which made ethanol production unprofitable. This is because dry-mill plant converts a single type of biomass feedstock (corn

Dynamic modelling and adaptive robust tracking control of a space robot with two-link flexible manipulators under unknown disturbances

Science.gov (United States)

Yang, Xinxin; Ge, Shuzhi Sam; He, Wei

2018-04-01

In this paper, both the closed-form dynamics and adaptive robust tracking control of a space robot with two-link flexible manipulators under unknown disturbances are developed. The dynamic model of the system is described with assumed modes approach and Lagrangian method. The flexible manipulators are represented as Euler-Bernoulli beams. Based on singular perturbation technique, the displacements/joint angles and flexible modes are modelled as slow and fast variables, respectively. A sliding mode control is designed for trajectories tracking of the slow subsystem under unknown but bounded disturbances, and an adaptive sliding mode control is derived for slow subsystem under unknown slowly time-varying disturbances. An optimal linear quadratic regulator method is proposed for the fast subsystem to damp out the vibrations of the flexible manipulators. Theoretical analysis validates the stability of the proposed composite controller. Numerical simulation results demonstrate the performance of the closed-loop flexible space robot system.

Whole-brain structural topology in adult attention-deficit/hyperactivity disorder: Preserved global – disturbed local network organization

Directory of Open Access Journals (Sweden)

Justina Sidlauskaite

2015-01-01

Full Text Available Prior studies demonstrate altered organization of functional brain networks in attention-deficit/hyperactivity disorder (ADHD. However, the structural underpinnings of these functional disturbances are poorly understood. In the current study, we applied a graph-theoretic approach to whole-brain diffusion magnetic resonance imaging data to investigate the organization of structural brain networks in adults with ADHD and unaffected controls using deterministic fiber tractography. Groups did not differ in terms of global network metrics — small-worldness, global efficiency and clustering coefficient. However, there were widespread ADHD-related effects at the nodal level in relation to local efficiency and clustering. The affected nodes included superior occipital, supramarginal, superior temporal, inferior parietal, angular and inferior frontal gyri, as well as putamen, thalamus and posterior cerebellum. Lower local efficiency of left superior temporal and supramarginal gyri was associated with higher ADHD symptom scores. Also greater local clustering of right putamen and lower local clustering of left supramarginal gyrus correlated with ADHD symptom severity. Overall, the findings indicate preserved global but altered local network organization in adult ADHD implicating regions underpinning putative ADHD-related neuropsychological deficits.

Thermospheric/ionospheric disturbances under quiet and magneto-perturbed conditions

Science.gov (United States)

Zakharov, Ivan G.; Mozgovaya, O. L.

2003-04-01

The basic mechanisms of ionospheric storms (IS) are investigated sufficiently full. Despite of it a quantitative forecast of ionospheric disturbance is not always satisfactory. One of the possible causes can be related to the insufficient account of a background ionospheric. In particualr using electron concentration Ne in the peak of F2-region and total electron content are shown, that the amplitude of a IS positive phase for similar magnetic storms can differ by ~1,5 times. Hence a cause of distinction can be variations in the thermosphere conditions, not reflected by known activity indices. For further research we used the incoherent scatter radar data of the Institute of ionosphere in height range 200-1000 km in the very quiet periods coming to the geomagnetic disturbance. A steady periodic disturbance in Ne during quiet conditions in all heights is established, which can be identified as tidal moda m=6. The amplitude of wave is ~15%, the phase changes with a height. The storm onset leads to an increase of the amplitudes approximately twice without a change in the phase. An ionospheric disturbance in very quiet conditions can lead to additional complicating an ionosphere reaction to magnetic storm.

Value of MRI of the brain in patients with systemic lupus erythematosus and neurologic disturbance

International Nuclear Information System (INIS)

Jennings, J.E.; Sundgren, P.C.; Maly, P.; Attwood, J.; McCune, J.

2004-01-01

Our objective was to review the frequency and pattern of signal abnormalities seen on conventional MRI in patients with suspected neuropsychiatric systemic lupus erythematosus (NP-SLE). We reviewed 116 MRI examinations of the brain performed on 85 patients with SLE, (81 women, four men, aged 21-78 years, mean 40.6 years) presenting with neurological disturbances. MRI was normal or nearly normal in 34%. In 60% high-signal lesions were observed on T2-weighted images, frequently in the frontal and parietal subcortical white matter. Infarct-like lesions involving gray and white matter were demonstrated in 21 of cases. Areas of restricted diffusion were seen in 12 of the 67 patients who underwent diffusion-weighted imaging. Other abnormalities included loss of brain volume, hemorrhage, meningeal enhancement, and bilateral high signal in occipital white-matter. The MRI findings alone did not allow us to distinguish between thromboembolic and inflammatory events in many patients. Some patients with normal MRI improved clinically while on immunosuppressive therapy. More sensitive and/or specific imaging methods, such as spectroscopy and perfusion-weighted imaging, should be investigated in these subgroups of patients with suspected NP-SLE. (orig.)

Optimization of Vehicular Trajectories under Gaussian Noise Disturbances

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Joan Garcia-Haro

2012-12-01

Full Text Available Nowadays, research on Vehicular Technology aims at automating every single mechanical element of vehicles, in order to increase passengers’ safety, reduce human driving intervention and provide entertainment services on board. Automatic trajectory tracing for vehicles under especially risky circumstances is a field of research that is currently gaining enormous attention. In this paper, we show some results on how to develop useful policies to execute maneuvers by a vehicle at high speeds with the mathematical optimization of some already established mobility conditions of the car. We also study how the presence of Gaussian noise on measurement sensors while maneuvering can disturb motion and affect the final trajectories. Different performance criteria for the optimization of such maneuvers are presented, and an analysis is shown on how path deviations can be minimized by using trajectory smoothing techniques like the Kalman Filter. We finalize the paper with a discussion on how communications can be used to implement these schemes.

CORRECTION OF DISTURBED NEUROIMMUNE INTERACTIONS IN EXPERIMENTAL TRAUMATIC BRAIN INJURY BY MEANS OF RECOMBINANT INTERLEUKIN 2

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S. N. Shanin

2018-01-01

Full Text Available Traumatic brain injury (TBI commonly proceeds as a severe disease with high morbidity that can lead to neurological disorders in some of these patients. TBI is associated by multidirectional abnormalities of immune system, which affect quantity and functions of T-, B-, and NK-lymphocytes leading to infectious complications or autosensibilization. Restoration of the disturbances in neuroimmune interactions after TBI may be achieved by means of immunomodulators that have neuroprotective properties and may potentially initiate regenerative CNS activity. IL-2 is a cytokine that possesses neurooperative and neuroprotective properties. In immune system, IL-2 is produced by T-cells in response to antigen stimuli; in CNS, by brain cells. Lack of IL-2 production by both T-lymphocytes and brain cells increases a possibility of autoimmune and inflammatory pathologies. The objective of present study was to evaluate possible effects of human recombinant IL-2 (rIL-2, Roncoleukin®, Biothech Ltd., Russia upon state and correction of immune and neuro-endocrine TBI consequences. The study was performed in adult Wistar rats. Mechanical TBI was produced by the dropping load model. 72 hours after inflicting the TBI, r-IL-2, at dose 30 mg/kg was injected once a day for three times. The animals from control group received 0.15M NaCl solution over the same period. The results have shown that, within first hours and days after TBI, corticosterone levels showed a sharp increase, whereas testosterone concentrations were decreased.In parallel, an increase in cytotoxic and proliferative activity of splenocytes was revealed, as well as increased number of splenocytes at their late apoptotic stage. Three daily injections of rIL-2 resulted into a significant increase in corticosterone and testosterone levels in injured animals on the day 7 after TBI. The animals treated with rIL-2 have exhibited more rapid normalization of cytotoxic and proliferative activity of splenocytes

Climate change and forest disturbances

Science.gov (United States)

Virginia H. Dale; Linda A. Joyce; Steve McNulty; Ronald P. Neilson; Matthew P. Ayres; Michael D. Flannigan; Paul J. Hanson; Lloyd C. Irland; Ariel E. Lugo; Chris J. Peterson; Daniel Simberloff; Frederick J. Swanson; Brian J. Stocks; Michael Wotton

2001-01-01

This article examines how eight disturbances influence forest structure, composition, and function, and how climate change may influence the severity, frequency, and magnitude of disturbances to forests. We focus on examples from the United States, although these influences occur worldwide. We also consider options for coping with disturbance under changing climate....

Nonlinear modeling and stability analysis of hydro-turbine governing system with sloping ceiling tailrace tunnel under load disturbance

International Nuclear Information System (INIS)

Guo, Wencheng; Yang, Jiandong; Wang, Mingjiang; Lai, Xu

2015-01-01

Highlights: • Novel nonlinear mathematical model of hydro-turbine governing system is proposed. • Hopf bifurcation analysis on the governing system is conducted. • Stability of the system under load disturbance is studied. • Influence of four factors on stability is analyzed. • Optimization methods of improving system stability are put forward. - Abstract: In order to overcome the problem of nonlinear dynamics of hydro-turbine governing system with sloping ceiling tailrace tunnel, which is caused by the interface movement of the free surface-pressurized flow in the tailrace tunnel, and the difficulty of analyzing the stability of system, this paper uses the Hopf bifurcation theory to study the stability of hydro-turbine governing system of hydropower station with sloping ceiling tailrace tunnel. Firstly, a novel and rational nonlinear mathematical model of the hydro-turbine governing system is proposed. This model contains the dynamic equation of pipeline system which can accurately describe the motion characteristics of the interface of free surface-pressurized flow in sloping ceiling tailrace tunnel. According to the nonlinear mathematical model, the existence and direction of Hopf bifurcation of the nonlinear dynamic system are analyzed. Furthermore, the algebraic criterion of the occurrence of Hopf bifurcation is derived. Then the stability domain and bifurcation diagram of hydro-turbine governing system are drawn by the algebraic criterion, and the characteristics of stability under different state parameters are investigated. Finally, the influence of step load value, ceiling slope angle and section form of tailrace tunnel and water depth at the interface in tailrace tunnel on stability are analyzed based on stable domain. The results indicate that: The Hopf bifurcation of hydro-turbine governing system with sloping ceiling tailrace tunnel is supercritical. The phase space trajectories of characteristic variables stabilize at the equilibrium points

Small-scale variations in leaf shape under anthropogenic disturbance in dioecious forest forb mercurialis perennis: A geometric morphometric examination

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Vujić Vukica

2016-01-01

Full Text Available Plants are exposed to increasing levels of diverse human activities that have profound effects on their overall morphology and, specifically, on leaf morphology. Anthropogenic disturbances in urban and suburban forest recreational sites are attracting growing research interest. To explore the persisting recreational impact on leaf shape and size, we conducted a field study on the dioecious forb Mercurialis perennis L. (Euphorbiaceae, typical for undisturbed understory communities. We selected adjacent sites in a suburban forest, which experience contrasting regimes of disturbance by human trampling under otherwise concordant natural conditions. Patterns of leaf shape and size variation and putative sex-specific response to disturbance were analyzed using a geometric morphometric approach. In addition to leaf-level data, plant height, internode and leaf number were analyzed to explore the same response at the whole-plant level. The results show significant variations associated with disturbance at both levels: plants growing under a heavy disturbance regime had shorter stems with a greater number of wider and shorter leaves. Significant differences between sites were also found for leaf size, with larger leaves observed in an undisturbed site. The effects of sex and sex x site interaction on leaf size and shape were nonsignificant, pointing to the absence of sexual dimorphism and sex-specific response to disturbance. Contrary to leaf shape and size, all three analyzed shoot traits showed highly significant sexual dimorphism, with male plants being higher and having higher leaf and internode count. [Projekat Ministarstva nauke Republike Srbije, br. 173025

Alteration of the irisin–brain-derived neurotrophic factor axis contributes to disturbance of mood in COPD patients

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Papp C

2017-07-01

Full Text Available Csaba Papp,1 Krisztian Pak,2 Tamas Erdei,2 Bela Juhasz,2 Ildiko Seres,3 Anita Szentpéteri,3 Laszlo Kardos,4 Maria Szilasi,5 Rudolf Gesztelyi,2 Judit Zsuga1 1Department of Health Systems Management and Quality Management for Health Care, Faculty of Public Health, 2Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, 3Department of Internal Medicine, Faculty of Medicine, University of Debrecen, 4Department of Clinical Pharmacology, Infectious Diseases and Allergology, Kenezy Gyula Teaching County Hospital and Outpatient Clinic, 5Department of Pulmonology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary Abstract: COPD is accompanied by limited physical activity, worse quality of life, and increased prevalence of depression. A possible link between COPD and depression may be irisin, a myokine, expression of which in the skeletal muscle and brain positively correlates with physical activity. Irisin enhances the synthesis of brain-derived neurotrophic factor (BDNF, a neurotrophin involved in reward-related processes. Thus, we hypothesized that mood disturbances accompanying COPD are reflected by the changes in the irisin–BDNF axis. Case history, routine laboratory parameters, serum irisin and BDNF levels, pulmonary function, and disease-specific quality of life, measured by St George’s Respiratory Questionnaire (SGRQ, were determined in a cohort of COPD patients (n=74. Simple and then multiple linear regression were used to evaluate the data. We found that mood disturbances are associated with lower serum irisin levels (SGRQ’s Impacts score and reciprocal of irisin showed a strong positive association; β: 419.97; 95% confidence interval [CI]: 204.31, 635.63; P<0.001. This association was even stronger among patients in the lower 50% of BDNF levels (β: 434.11; 95% CI: 166.17, 702.05; P=0.002, while it became weaker for patients in the higher 50% of BDNF concentrations (β: 373.49; 95% CI: -74.91, 821.88; P=0

The 'selfish brain' is regulated by aquaporins and autophagy under nutrient deprivation.

Science.gov (United States)

Ye, Qiao; Wu, Yonghong; Gao, Yan; Li, Zhihui; Li, Weiguang; Zhang, Chenggang

2016-05-01

The brain maintains its mass and physiological functional capacity compared with other organs under harsh conditions such as starvation, a mechanism termed the 'selfish brain' theory. To further investigate this phenomenon, mice were examined following water and/or food deprivation. Although the body weights of the mice, the weight of the organs except the brain and blood glucose levels were significantly reduced in the absence of water and/or food, the brain weight maintained its original state. Furthermore, no significant differences in the water content of the brain or its energy balance were observed when the mice were subjected to water and/or food deprivation. To further investigate the mechanism underlying the brain maintenance of water and substance homeostasis, the expression levels of aquaporins (AQPs) and autophagy‑specific protein long‑chain protein 3 (LC3) were examined. During the process of water and food deprivation, no significant differences in the transcriptional levels of AQPs were observed. However, autophagy activity levels were initially stimulated, then suppressed in a time‑dependent manner. LC3 and AQPs have important roles for the survival of the brain under conditions of food and water deprivation, which provided further understanding of the mechanism underlying the 'selfish brain' phenomenon. Although not involved in the energy regulation of the 'selfish brain', AQPs were observed to have important roles in water and food deprivation, specifically with regards to the control of water content. Additionally, the brain exhibits an 'unselfish strategy' using autophagy during water and/or food deprivation. The present study furthered current understanding of the 'selfish brain' theory, and identified additional regulating target genes of AQPs and autophagy, with the aim of providing a basis for the prevention of nutrient shortage in humans and animals.

Interrelation between Neuroendocrine Disturbances and Medical Complications Encountered during Rehabilitation after TBI

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Caroline I. E. Renner

2015-09-01

Full Text Available Traumatic brain injury is not a discrete event but an unfolding sequence of damage to the central nervous system. Not only the acute phase but also the subacute and chronic period after injury, i.e., during inpatient rehabilitation, is characterized by multiple neurotransmitter alterations, cellular dysfunction, and medical complications causing additional secondary injury. Neuroendocrine disturbances also influence neurological outcome and are easily overlooked as they often present with diffuse symptoms such as fatigue, depression, poor concentration, or a decline in overall cognitive function; these are also typical sequelae of traumatic brain injury. Furthermore, neurological complications such as hydrocephalus, epilepsy, fatigue, disorders of consciousness, paroxysmal sympathetic hyperactivity, or psychiatric-behavioural symptoms may mask and/or complicate the diagnosis of neuroendocrine disturbances, delay appropriate treatment and impede neurorehabilitation. The present review seeks to examine the interrelation between neuroendocrine disturbances with neurological complications frequently encountered after moderate to severe TBI during rehabilitation. Common neuroendocrine disturbances and medical complications and their clinical implications are discussed.

Ionizing radiation action of transport systems of Na+ and K+ of neutronal membranes. Potassium ions reaccumulation with brain slices

International Nuclear Information System (INIS)

Dvoretsky, A.I.; Shainskaya, A.M.; Ananyeva, T.V.; Kulikova, I.A.

1990-01-01

The biological effect of ionizing radiation (IR) on the Na,K pump of the surviving brain cortex slices was investigated. It was shown that IR leads to marked disturbances in the Na,K pump activity and causes essential phasic changes in potassium ion reaccumulation by brain slices in different time after exposure. The possibility of modelling the radiation effect with the help of phospholipase A2 and decylenic acid was shown. The mechanisms of the functional disturbance of Na-K pump of nerve cells after irradiation are under discussion. (author)

To favor survival under food shortage, the brain disables costly memory.

Science.gov (United States)

Plaçais, Pierre-Yves; Preat, Thomas

2013-01-25

The brain regulates energy homeostasis in the organism. Under resource shortage, the brain takes priority over peripheral organs for energy supply. But can the brain also down-regulate its own consumption to favor survival? We show that the brain of Drosophila specifically disables the costly formation of aversive long-term memory (LTM) upon starvation, a physiological state required for appetitive LTM formation. At the neural circuit level, the slow oscillations normally triggered in two pairs of dopaminergic neurons to enable aversive LTM formation were abolished in starved flies. Transient artificial activation of these neurons during training restored LTM formation in starved flies but at the price of a reduced survival. LTM formation is thus subject to adaptive plasticity that helps survival under food shortage.

[Changes in vegetation and soil characteristics under tourism disturbance in lakeside wetland of northwest Yunnan Plateau, Southwest China].

Science.gov (United States)

Tang, Ming-Yan; Yang, Yong-Xing

2014-05-01

The characteristics of vegetation and soil were investigated in Bita Lake and Shudu Lake wetlands in northwest Yunnan Plateau under tourism disturbance. The 22 typical plots in the wetlands were classified into 4 types by TWINSPAN, including primary wetland, light degradation, moderate degradation, and severe degradation. Along the degradation gradient, the plant community density, coverage, species number and Shannon diversity index increased and the plant height decreased in Bita Lake and Shudu Lake wetlands, and Whittaker diversity index increased in Bita Lake wetland. Plant species number, soil organic matter, total nitrogen, porosity, available nitrogen, available phosphorus and available potassium contents were higher in Shudu Lake wetland than in Bita Lake wetland, but the plant density, height, soil total potassium and pH were opposite. Canonical correspondence analysis (CCA) by importance values of 42 plants and 11 soil variables showed that soil organic matter, total nitrogen and total potassium were the key factors on plant species distribution in Bita Lake and Shudu Lake wetlands under tourism disturbance. TWINSPAN classification and analysis of vegetation-soil characteristics indicated the effects of tourism disturbance in Bita Lake wetland were larger than in Shudu Lake wetland.

Brain network disturbance related to posttraumatic stress and traumatic brain injury in veterans.

Science.gov (United States)

Spielberg, Jeffrey M; McGlinchey, Regina E; Milberg, William P; Salat, David H

2015-08-01

Understanding the neural causes and consequences of posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) is a high research priority, given the high rates of associated disability and suicide. Despite remarkable progress in elucidating the brain mechanisms of PTSD and mTBI, a comprehensive understanding of these conditions at the level of brain networks has yet to be achieved. The present study sought to identify functional brain networks and topological properties (measures of network organization and function) related to current PTSD severity and mTBI. Graph theoretic tools were used to analyze resting-state functional magnetic resonance imaging data from 208 veterans of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn, all of whom had experienced a traumatic event qualifying for PTSD criterion A. Analyses identified brain networks and topological network properties linked to current PTSD symptom severity, mTBI, and the interaction between PTSD and mTBI. Two brain networks were identified in which weaker connectivity was linked to higher PTSD re-experiencing symptoms, one of which was present only in veterans with comorbid mTBI. Re-experiencing was also linked to worse functional segregation (necessary for specialized processing) and diminished influence of key regions on the network, including the hippocampus. Findings of this study demonstrate that PTSD re-experiencing symptoms are linked to weakened connectivity in a network involved in providing contextual information. A similar relationship was found in a separate network typically engaged in the gating of working memory, but only in veterans with mTBI. Published by Elsevier Inc.

The International Research Training Group on "Brain-Behavior Relationship of Normal and Disturbed Emotions in Schizophrenia and Autism" as an Example of German-American Cooperation in Doctoral Training

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Schneider, Frank; Gur, Ruben C.

2008-01-01

The International Research Training Group "Brain-Behavior Relationship of Normal and Disturbed Emotions in Schizophrenia and Autism" (IRTG 1328), funded by the German Research Council (DFG), is a German-American cooperation. Its major aims are interdisciplinary and international scientific cooperation and the support of young scientists…

The effect of natural disturbances on the risk from hydrogeomorphic hazards under climate change

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Scheidl, Christian; Thaler, Thomas; Seidl, Rupert; Rammer, Werner; Kohl, Bernhard; Markart, Gerhard

2017-04-01

Recent storm events in Austria show once more how floods, sediment transport processes and debris flows constitute a major threat in alpine regions with a high density of population and an increasing spatial development. As protection forests have a major control function on runoff and erosion, they directly affect the risk from such hydrogeomorphic processes. However, research on future climate conditions, with an expected increase of the global average surface temperature of 3-5°C by 2100, compared to the first decade of the 20th century, raises a number of open questions for a sustainable and improved hazard management in mountain forests. For Europe, for instance, a climate-induced increase in forest disturbances like wildfire, wind, and insect's outbreaks is highly likely for the coming decades. Especially in protection forests, future scenarios of such climate induced natural disturbances and their impact on the protective effect remain an unresolved issue. Combining methods from forestry, hydrology and geotechnical engineering our project uses an integral approach to simulate possible effects of natural disturbances on hydrogeomorphic hazards in the perspective of future protection forest developments. With the individual-based forest landscape and disturbance model (iLand) we conduct an ensemble of forest landscape simulations, assessing the impact of future changes in natural disturbance regimes in four selected torrential catchments. These catchments are situated in two different forest growth areas. Drainage rate simulations are based on the conceptual hydrological model (ZEMOKOST), whereas simulations of the effect of forest disturbances on hillslope erosion processes are conducted by the Distributed Hydrology Soil Vegetation Model (DHSVM). Beside process based simulations, we also emphasis to identify the risk perception and adaptive capacity to mitigate a probable loss of protection functions in forests. For this reason, a postal survey among

Structure of magnetic field disturbances under development of disruptive instability in the ''Tokamak-6''

International Nuclear Information System (INIS)

Merezhkin, V.G.

1978-01-01

The structure and dynamics of disturbances of a poloidal field during the development of the breakaway instability in the Tokamak-6 are investigated. The behaviour of the symmetric and dipole field component, and the peculiarities of the structure of screw disturbances in a minor and major breakaways are analyzed. It was established that the structure of screw disturbances in minor breakaways is unchangeable and that the rearrangement in major breakaways is of a discrete nature. The relationship between the symmetric and screw components of disturbances of the poloidal field at the forward front of the disturbance increase was revealed. Data on the increments, scales and structure of screw disturbances, the ratios between the symmetric and screw components of field disturbances, and also on the magnitude of energy losses in typical breakaways are given

Visuospatial Attention Disturbance in Duchenne Muscular Dystrophy

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De Moura, Maria Clara Drummond Soares; do Valle, Luiz Eduardo Ribeiro; Resende, Maria Bernadete Dutra; Pinto, Katia Osternack

2010-01-01

Aim: The cognitive deficits present in the Duchenne muscular dystrophy (DMD) are not yet well characterized. Attention, considered to be the brain mechanism responsible for the selection of sensory stimuli, could be disturbed in DMD, contributing, at least partially, to the observed global cognitive deficit. The aim of this study was to…

Idaho forest carbon projections from 2017 to 2117 under forest disturbance and climate change scenarios

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Hudak, A. T.; Crookston, N.; Kennedy, R. E.; Domke, G. M.; Fekety, P.; Falkowski, M. J.

2017-12-01

Commercial off-the-shelf lidar collections associated with tree measures in field plots allow aboveground biomass (AGB) estimation with high confidence. Predictive models developed from such datasets are used operationally to map AGB across lidar project areas. We use a random selection of these pixel-level AGB predictions as training for predicting AGB annually across Idaho and western Montana, primarily from Landsat time series imagery processed through LandTrendr. At both the landscape and regional scales, Random Forests is used for predictive AGB modeling. To project future carbon dynamics, we use Climate-FVS (Forest Vegetation Simulator), the tree growth engine used by foresters to inform forest planning decisions, under either constant or changing climate scenarios. Disturbance data compiled from LandTrendr (Kennedy et al. 2010) using TimeSync (Cohen et al. 2010) in forested lands of Idaho (n=509) and western Montana (n=288) are used to generate probabilities of disturbance (harvest, fire, or insect) by land ownership class (public, private) as well as the magnitude of disturbance. Our verification approach is to aggregate the regional, annual AGB predictions at the county level and compare them to annual county-level AGB summarized independently from systematic, field-based, annual inventories conducted by the US Forest Inventory and Analysis (FIA) Program nationally. This analysis shows that when federal lands are disturbed the magnitude is generally high and when other lands are disturbed the magnitudes are more moderate. The probability of disturbance in corporate lands is higher than in other lands but the magnitudes are generally lower. This is consistent with the much higher prevalence of fire and insects occurring on federal lands, and greater harvest activity on private lands. We found large forest carbon losses in drier southern Idaho, only partially offset by carbon gains in wetter northern Idaho, due to anticipated climate change. Public and

The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity.

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Bongers, Frans; Poorter, Lourens; Hawthorne, William D; Sheil, Douglas

2009-08-01

The intermediate disturbance hypothesis (IDH) predicts local species diversity to be maximal at an intermediate level of disturbance. Developed to explain species maintenance and diversity patterns in species-rich ecosystems such as tropical forests, tests of IDH in tropical forest remain scarce, small-scale and contentious. We use an unprecedented large-scale dataset (2504 one-hectare plots and 331,567 trees) to examine whether IDH explains tree diversity variation within wet, moist and dry tropical forests, and we analyse the underlying mechanism by determining responses within functional species groups. We find that disturbance explains more variation in diversity of dry than wet tropical forests. Pioneer species numbers increase with disturbance, shade-tolerant species decrease and intermediate species are indifferent. While diversity indeed peaks at intermediate disturbance levels little variation is explained outside dry forests, and disturbance is less important for species richness patterns in wet tropical rain forests than previously thought.

Artificial neural networks for control of a grid-connected rectifier/inverter under disturbance, dynamic and power converter switching conditions.

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Li, Shuhui; Fairbank, Michael; Johnson, Cameron; Wunsch, Donald C; Alonso, Eduardo; Proaño, Julio L

2014-04-01

Three-phase grid-connected converters are widely used in renewable and electric power system applications. Traditionally, grid-connected converters are controlled with standard decoupled d-q vector control mechanisms. However, recent studies indicate that such mechanisms show limitations in their applicability to dynamic systems. This paper investigates how to mitigate such restrictions using a neural network to control a grid-connected rectifier/inverter. The neural network implements a dynamic programming algorithm and is trained by using back-propagation through time. To enhance performance and stability under disturbance, additional strategies are adopted, including the use of integrals of error signals to the network inputs and the introduction of grid disturbance voltage to the outputs of a well-trained network. The performance of the neural-network controller is studied under typical vector control conditions and compared against conventional vector control methods, which demonstrates that the neural vector control strategy proposed in this paper is effective. Even in dynamic and power converter switching environments, the neural vector controller shows strong ability to trace rapidly changing reference commands, tolerate system disturbances, and satisfy control requirements for a faulted power system.

Fundamental Dynamical Modes Underlying Human Brain Synchronization

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Catalina Alvarado-Rojas

2012-01-01

Full Text Available Little is known about the long-term dynamics of widely interacting cortical and subcortical networks during the wake-sleep cycle. Using large-scale intracranial recordings of epileptic patients during seizure-free periods, we investigated local- and long-range synchronization between multiple brain regions over several days. For such high-dimensional data, summary information is required for understanding and modelling the underlying dynamics. Here, we suggest that a compact yet useful representation is given by a state space based on the first principal components. Using this representation, we report, with a remarkable similarity across the patients with different locations of electrode placement, that the seemingly complex patterns of brain synchrony during the wake-sleep cycle can be represented by a small number of characteristic dynamic modes. In this space, transitions between behavioral states occur through specific trajectories from one mode to another. These findings suggest that, at a coarse level of temporal resolution, the different brain states are correlated with several dominant synchrony patterns which are successively activated across wake-sleep states.

Future 400 kV Algerian network and radio electric disturbances in dry weather and under rain

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Brahami M.

2007-01-01

Full Text Available The development of the electrical power networks to very high voltage (V.H.V reveals problems involved in the high electric fields; it is essential to consider it in the design of installations in order to avoid or to mitigate some problematic or dangerous effects. Among the most important harmful effects, we can note the "radio interference disturbances". The principal aim of this paper is the use of a simulation programme using an analytical method based on the theory of propagation modes, made by one of the authors, for determination and calculation of the exact profile of disturbance field of actual high voltage lines (220 kV and in project (400 kV in dry weather and under rain. Specific software called "effect corona" was developed for this purpose.

Temporal and spatial evolution characteristics of disturbance wave in a hypersonic boundary layer due to single-frequency entropy disturbance.

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Wang, Zhenqing; Tang, Xiaojun; Lv, Hongqing; Shi, Jianqiang

2014-01-01

By using a high-order accurate finite difference scheme, direct numerical simulation of hypersonic flow over an 8° half-wedge-angle blunt wedge under freestream single-frequency entropy disturbance is conducted; the generation and the temporal and spatial nonlinear evolution of boundary layer disturbance waves are investigated. Results show that, under the freestream single-frequency entropy disturbance, the entropy state of boundary layer is changed sharply and the disturbance waves within a certain frequency range are induced in the boundary layer. Furthermore, the amplitudes of disturbance waves in the period phase are larger than that in the response phase and ablation phase and the frequency range in the boundary layer in the period phase is narrower than that in these two phases. In addition, the mode competition, dominant mode transformation, and disturbance energy transfer exist among different modes both in temporal and in spatial evolution. The mode competition changes the characteristics of nonlinear evolution of the unstable waves in the boundary layer. The development of the most unstable mode along streamwise relies more on the motivation of disturbance waves in the upstream than that of other modes on this motivation.

High Dietary Fructose: Direct or Indirect Dangerous Factors Disturbing Tissue and Organ Functions.

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Zhang, Dong-Mei; Jiao, Rui-Qing; Kong, Ling-Dong

2017-03-29

High dietary fructose is a major contributor to insulin resistance and metabolic syndrome, disturbing tissue and organ functions. Fructose is mainly absorbed into systemic circulation by glucose transporter 2 (GLUT2) and GLUT5, and metabolized in liver to produce glucose, lactate, triglyceride (TG), free fatty acid (FFA), uric acid (UA) and methylglyoxal (MG). Its extrahepatic absorption and metabolism also take place. High levels of these metabolites are the direct dangerous factors. During fructose metabolism, ATP depletion occurs and induces oxidative stress and inflammatory response, disturbing functions of local tissues and organs to overproduce inflammatory cytokine, adiponectin, leptin and endotoxin, which act as indirect dangerous factors. Fructose and its metabolites directly and/or indirectly cause oxidative stress, chronic inflammation, endothelial dysfunction, autophagy and increased intestinal permeability, and then further aggravate the metabolic syndrome with tissue and organ dysfunctions. Therefore, this review addresses fructose-induced metabolic syndrome, and the disturbance effects of direct and/or indirect dangerous factors on the functions of liver, adipose, pancreas islet, skeletal muscle, kidney, heart, brain and small intestine. It is important to find the potential correlations between direct and/or indirect risk factors and healthy problems under excess dietary fructose consumption.

High Dietary Fructose: Direct or Indirect Dangerous Factors Disturbing Tissue and Organ Functions

Directory of Open Access Journals (Sweden)

Dong-Mei Zhang

2017-03-01

Full Text Available High dietary fructose is a major contributor to insulin resistance and metabolic syndrome, disturbing tissue and organ functions. Fructose is mainly absorbed into systemic circulation by glucose transporter 2 (GLUT2 and GLUT5, and metabolized in liver to produce glucose, lactate, triglyceride (TG, free fatty acid (FFA, uric acid (UA and methylglyoxal (MG. Its extrahepatic absorption and metabolism also take place. High levels of these metabolites are the direct dangerous factors. During fructose metabolism, ATP depletion occurs and induces oxidative stress and inflammatory response, disturbing functions of local tissues and organs to overproduce inflammatory cytokine, adiponectin, leptin and endotoxin, which act as indirect dangerous factors. Fructose and its metabolites directly and/or indirectly cause oxidative stress, chronic inflammation, endothelial dysfunction, autophagy and increased intestinal permeability, and then further aggravate the metabolic syndrome with tissue and organ dysfunctions. Therefore, this review addresses fructose-induced metabolic syndrome, and the disturbance effects of direct and/or indirect dangerous factors on the functions of liver, adipose, pancreas islet, skeletal muscle, kidney, heart, brain and small intestine. It is important to find the potential correlations between direct and/or indirect risk factors and healthy problems under excess dietary fructose consumption.

Effects of Flood Control Strategies on Flood Resilience Under Sociohydrological Disturbances

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Sung, Kyungmin; Jeong, Hanseok; Sangwan, Nikhil; Yu, David J.

2018-04-01

A community capacity to cope with flood hazards, or community flood resilience, emerges from the interplay of hydrological and social processes. This interplay can be significantly influenced by the flood control strategy adopted by a society, i.e., how a society sets its desired flood protection level and strives to achieve this goal. And this interplay can be further complicated by rising land-sea level differences, seasonal water level fluctuations, and economic change. But not much research has been done on how various forms of flood control strategies affect human-flood interactions under these disturbances and therefore flood resilience in the long run. The current study is an effort to address these issues by developing a conceptual model of human-flood interaction mediated by flood control strategies. Our model extends the existing model of Yu et al. (2017), who investigated the flood resilience of a community-based flood protection system in coastal Bangladesh. The major extensions made in this study are inclusions of various forms of flood control strategies (both adaptive and nonadaptive ones), the challenge of rising land-sea level differences, and various high tide level scenarios generated from modifying the statistical variances and averages. Our results show that adaptive forms of flood control strategies tend to outperform nonadaptive ones for maintaining the model community's flood protection system. Adaptive strategies that dynamically adjust target flood protection levels through close monitoring of flood damages and social memories of flood risk can help the model community deal with various disturbances.

The Dimensionality of Body Image Disturbance.

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Galgan, Richard J.; And Others

1987-01-01

Examined personality variables in 75 male and 75 female college students. Found two dimensions underlying body image disturbance variables, one loading on body image dissatisfaction and one loading on body image disturbance. Low negative correlation between two factors suggests that distortion and dissatisfaction are fairly distinct and that body…

Spatiotemporal psychopathology I: No rest for the brain's resting state activity in depression? Spatiotemporal psychopathology of depressive symptoms.

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Northoff, Georg

2016-01-15

Despite intense neurobiological investigation in psychiatric disorders like major depressive disorder (MDD), the basic disturbance that underlies the psychopathological symptoms of MDD remains, nevertheless, unclear. Neuroimaging has focused mainly on the brain's extrinsic activity, specifically task-evoked or stimulus-induced activity, as related to the various sensorimotor, affective, cognitive, and social functions. Recently, the focus has shifted to the brain's intrinsic activity, otherwise known as its resting state activity. While various abnormalities have been observed during this activity, their meaning and significance for depression, along with its various psychopathological symptoms, are yet to be defined. Based on findings in healthy brain resting state activity and its particular spatial and temporal structure - defined in a functional and physiological sense rather than anatomical and structural - I claim that the various depressive symptoms are spatiotemporal disturbances of the resting state activity and its spatiotemporal structure. This is supported by recent findings that link ruminations and increased self-focus in depression to abnormal spatial organization of resting state activity. Analogously, affective and cognitive symptoms like anhedonia, suicidal ideation, and thought disorder can be traced to an increased focus on the past, increased past-focus as basic temporal disturbance o the resting state. Based on these findings, I conclude that the various depressive symptoms must be conceived as spatiotemporal disturbances of the brain's resting state's activity and its spatiotemporal structure. Importantly, this entails a new form of psychopathology, "Spatiotemporal Psychopathology" that directly links the brain and psyche, therefore having major diagnostic and therapeutic implications for clinical practice. Copyright © 2015 Elsevier B.V. All rights reserved.

A case of gait disturbance caused by low-dose gabapentin

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Kanao-Kanda, Megumi; Kanda, Hirotsugu; Takahata, Osamu; Kunisawa, Takayuki

2016-01-01

Gabapentin, an anticonvulsant agent, is now often used for the treatment of neuropathic pain all over the world. It is unclear whether the combined use of gabapentin, sodium valproate, and flunitrazepam results in enhancement of the side effect, a gait disturbance. A 60-year-old man was taking oral sodium valproate for symptomatic epilepsy after a brain contusion and flunitrazepam to relieve insomnia. Oral gabapentin therapy was started for suspected neuropathic pain. Although the initial dose of oral gabapentin (200 mg) relieved the pain, the lower extremities became weak, resulting in a gait disturbance. The therapy was restarted with a halved dose, and this resolved the gait disturbance and relieved the pain. PMID:27354808

Connectome-harmonic decomposition of human brain activity reveals dynamical repertoire re-organization under LSD.

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Atasoy, Selen; Roseman, Leor; Kaelen, Mendel; Kringelbach, Morten L; Deco, Gustavo; Carhart-Harris, Robin L

2017-12-15

Recent studies have started to elucidate the effects of lysergic acid diethylamide (LSD) on the human brain but the underlying dynamics are not yet fully understood. Here we used 'connectome-harmonic decomposition', a novel method to investigate the dynamical changes in brain states. We found that LSD alters the energy and the power of individual harmonic brain states in a frequency-selective manner. Remarkably, this leads to an expansion of the repertoire of active brain states, suggestive of a general re-organization of brain dynamics given the non-random increase in co-activation across frequencies. Interestingly, the frequency distribution of the active repertoire of brain states under LSD closely follows power-laws indicating a re-organization of the dynamics at the edge of criticality. Beyond the present findings, these methods open up for a better understanding of the complex brain dynamics in health and disease.

Re-irradiation for metastatic brain tumors with whole-brain radiotherapy

International Nuclear Information System (INIS)

Akiba, Takeshi; Kunieda, Etsuo; Kogawa, Asuka; Komatsu, Tetsuya; Tamai, Yoshifumi; Ohizumi, Yukio

2012-01-01

The objective of this study was to determine whether second whole-brain irradiation is beneficial for patients previously treated with whole-brain irradiation. A retrospective analysis was done for 31 patients with brain metastases who had undergone re-irradiation. Initial whole-brain irradiation was performed with 30 Gy/10 fractions for 87% of these patients. Whole-brain re-irradiation was performed with 30 Gy/10 fractions for 42% of these patients (3-40 Gy/1-20 fractions). Three patients underwent a third whole-brain irradiation. The median interval between the initial irradiation and re-irradiation was 10 months (range: 2-69 months). The median survival time after re-irradiation was 4 months (range: 1-21 months). The symptomatic improvement rate after re-irradiation was 68%, and the partial and complete tumor response rate was 55%. Fifty-two percent of the patients developed Grade 1 acute reactions. On magnetic resonance imaging, brain atrophy was observed in 36% of these patients after the initial irradiation and 74% after re-irradiation. Grade ≥2 encephalopathy or cognitive disturbance was observed in 10 patients (32%) after re-irradiation. Based on univariate analysis, significant factors related to survival after re-irradiation were the location of the primary cancer (P=0.003) and the Karnofsky performance status at the time of re-irradiation (P=0.008). A Karnofsky performance status ≥70 was significant based on multivariate analysis (P=0.050). Whole-brain re-irradiation for brain metastases placed only a slight burden on patients and was effective for symptomatic improvement. However, their remaining survival time was limited and the incidence of cognitive disturbance was rather high. (author)

Clinical application of synthesized brain surface imaging for preoperative simulation of brain biopsy under local anesthesia

International Nuclear Information System (INIS)

Ogura, Yuko; Katada, Kazuhiro; Imai, Fumihiro; Fujisawa, Kazuhisa; Takeshita, Gen; Kanno, Tetsuo; Koga, Sukehiko

1994-01-01

Surface anatomy scanning (SAS) is the technique which permits the direct visualization of brain surface structures, including cortical sulci, guri, subcortical lesions as well as skin markings for craniotomy. A synthesized brain surface image is a technique that combines MR angiography (MRA) with SAS, and it proposed by us for detecting cerebral superficial veins with these surface structures on the same image. The purpose of this report is to present the result of applying the synthesized brain surface image to the preoperative simulation of biopsy under local anesthesia in 2 cases of multiple metastatic brain tumors. The parameters for SAS were TR/TE=50/40 msec, flip angle=60deg by the fast T 2 technique using refocused FID in steady-state (STERF technique). SAS images were processed by gray scale reversal. The MRA data were acquired with two-dimensional time of flight (TOF) sequence after intravenous administration of Gd-DTPA. Before imaging, the water-filled plastic tubes were placed on the patients scalp as markings for craniotomy. Their positions were planned by the neurosurgeons. On SAS, the markings for burr-hole appeared located above the tumors. However on the synthesized brain surface images, the positions of burr-hole were considered to be inadequate, since superficial cerebral vein and sinus were also visualized in the area of the markings. From these results, the positions of burr-hole were reset to avoid the venous structures, and so as to include the lesions in operations. The biopsies were performed successfully and safely because the venous structure could be excluded from the operative field. By this technique it was easy to confirm the relationships among lesions, skin markings and venous structures. The technique described appears to be a useful method for preoperative simulation of biopsies for multiple metastatic brain tumors under local anesthesia. (author)

Interactions of landscape disturbances and climate change dictate ecological pattern and process: spatial modeling of wildfire, insect, and disease dynamics under future climates

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Loehman, Rachel A.; Keane, Robert E.; Holsinger, Lisa M.; Wu, Zhiwei

2016-01-01

ContextInteractions among disturbances, climate, and vegetation influence landscape patterns and ecosystem processes. Climate changes, exotic invasions, beetle outbreaks, altered fire regimes, and human activities may interact to produce landscapes that appear and function beyond historical analogs.ObjectivesWe used the mechanistic ecosystem-fire process model FireBGCv2 to model interactions of wildland fire, mountain pine beetle (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola) under current and future climates, across three diverse study areas.MethodsWe assessed changes in tree basal area as a measure of landscape response over a 300-year simulation period for the Crown of the Continent in north-central Montana, East Fork of the Bitterroot River in western Montana, and Yellowstone Central Plateau in western Wyoming, USA.ResultsInteracting disturbances reduced overall basal area via increased tree mortality of host species. Wildfire decreased basal area more than beetles or rust, and disturbance interactions modeled under future climate significantly altered landscape basal area as compared with no-disturbance and current climate scenarios. Responses varied among landscapes depending on species composition, sensitivity to fire, and pathogen and beetle suitability and susceptibility.ConclusionsUnderstanding disturbance interactions is critical for managing landscapes because forest responses to wildfires, pathogens, and beetle attacks may offset or exacerbate climate influences, with consequences for wildlife, carbon, and biodiversity.

Zinc movement in the brain under kainate-induced seizures.

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Takeda, Atsushi; Hirate, Maki; Tamano, Haruna; Oku, Naoto

2003-05-01

On the basis of the evidence that elimination of 65Zn from the brain of epilepsy (EL) mice is facilitated by induction of seizures, zinc movement in the brain was studied in mice injected with kainate (12 mg/kg x 3), which exhibited status epilepticus within 120 min after the last injection of kainate. Zinc concentrations in the brain were determined 24 h after the last injection of kainate. Zinc concentrations in the hippocampus, amygdala and cerebral cortex, in which zinc-containing glutamatergic neuron terminals exist, were significantly decreased by the treatment with kainate, while that in the cerebellum was not decreased. Timm's stain in the brain was extensively attenuated 24 h after the last injection of kainate. These results indicate that zinc homeostasis in the brain is affected by kainate-induced seizures. In the hippocampus of rats injected with kainate (10 mg/kg), furthermore, the release of zinc and glutamate into the extracellular fluid was studied using in vivo microdialysis. The levels of zinc and glutamate in the perfusate were increased along with seizure severity after injection of kainate. It is likely that zinc concentration in the synaptic vesicles is decreased by the excess excitation of glutamatergic neurons. The present study suggests that the excessive release of zinc and glutamate from the neuron terminals under kainate-induced seizures is associated with the loss of zinc from the brain.

Histological Architecture Underlying Brain-Immune Cell-Cell Interactions and the Cerebral Response to Systemic Inflammation.

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Shimada, Atsuyoshi; Hasegawa-Ishii, Sanae

2017-01-01

Although the brain is now known to actively interact with the immune system under non-inflammatory conditions, the site of cell-cell interactions between brain parenchymal cells and immune cells has been an open question until recently. Studies by our and other groups have indicated that brain structures such as the leptomeninges, choroid plexus stroma and epithelium, attachments of choroid plexus, vascular endothelial cells, cells of the perivascular space, circumventricular organs, and astrocytic endfeet construct the histological architecture that provides a location for intercellular interactions between bone marrow-derived myeloid lineage cells and brain parenchymal cells under non-inflammatory conditions. This architecture also functions as the interface between the brain and the immune system, through which systemic inflammation-induced molecular events can be relayed to the brain parenchyma at early stages of systemic inflammation during which the blood-brain barrier is relatively preserved. Although brain microglia are well known to be activated by systemic inflammation, the mechanism by which systemic inflammatory challenge and microglial activation are connected has not been well documented. Perturbed brain-immune interaction underlies a wide variety of neurological and psychiatric disorders including ischemic brain injury, status epilepticus, repeated social defeat, and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Proinflammatory status associated with cytokine imbalance is involved in autism spectrum disorders, schizophrenia, and depression. In this article, we propose a mechanism connecting systemic inflammation, brain-immune interface cells, and brain parenchymal cells and discuss the relevance of basic studies of the mechanism to neurological disorders with a special emphasis on sepsis-associated encephalopathy and preterm brain injury.

Brain neurotransmitters and hippocampal proteome in pigs under stress and environmental enrichment

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Laura Arroyo

2017-06-01

Full Text Available Stress and wellbeing are psychological conditions that are mediated by the central nervous system. In the brain, stress is mediated mainly by the hypothalamus, which will activate the hypothalamic-pituitary-adrenal (HPA axis, leading to the secretion of cortisol, the paradigmatic stress hormone. Other brain areas as the amygdala, the hippocampus or the prefrontal cortex (PFC are involved in emotions such as happiness, anxiety and fear. Communication between brain areas is achieved by chemical neurotransmitters (NTs, which are secreted by presynaptic neurons to reach postsynaptic neurons, where they will cause a variation in membrane polarization and other cell signaling actions, leading to physiological responses. Amongst these NTs, catecholamines (noradrenaline and dopamine and serotonin play an important role. On the other hand, the adverse effects of stress may be counteracted by housing the individuals under environmental enrichment conditions. This long-term situation should have an effect, not only on NTs, but also on the brain proteome. Under the hypothesis that different stress situations will lead to changes in NT composition that will be specific for crucial brain areas, we have tested the effects of transport stress, handling stress at the slaughterhouse, and the stress-susceptible genotype (Ryr1 on the amine NT concentration in amygdala, hippocampus, PFC and hypothalamus of pigs. The effects of living under environmentally enriched or control conditions on the NT concentration in several brain regions and on the hippocampus proteome has been also analyzed. In conclusion, genetic factors as well as management conditions related to housing, transport and slaughterhouse alter in different degree the catecholaminergic and the serotoninergic neurotransmission in the brain, and give clues about how different individual types are able to react to external challenges. Likewise, environmental enrichment leads to changes in the proteome

Psychopathology of Time in Brain Disease and Schizophrenia

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John Cutting

1990-01-01

Full Text Available The literature on disturbance of time-sense in brain disease and schizophrenia is reviewed and the subjective experience of altered time-sense reported by 45 out of 350 personally interviewed schizophrenics is analyzed. A review of the literature on the effect of brain damage revealed that some phenomena (déjà vu, reduplication of time, altered tempo to events were linked with right hemisphere dysfunction, one phenomenon (incorrect sequencing of events was linked with left anterior brain damage, and others (disrupted “biological clock”, disturbed serise of rate of flow of current or past events could arise from subcortical as well as focal cortical damage. The sparse literature on disturbed time-sense in schizophrenia suggested that there was a shared psychopathology in this respect with right hemisphere dysfunction. The phenomena encountered in the 45 schizophrenics are described and classified.

Response of a Hypersonic Boundary Layer to Freestream Pulse Acoustic Disturbance

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Zhenqing Wang

2014-01-01

Full Text Available The response of hypersonic boundary layer over a blunt wedge to freestream pulse acoustic disturbance was investigated. The stability characteristics of boundary layer for freestream pulse wave and continuous wave were analyzed comparatively. Results show that freestream pulse disturbance changes the thermal conductivity characteristics of boundary layer. For pulse wave, the number of main disturbance clusters decreases and the frequency band narrows along streamwise. There are competition and disturbance energy transfer among different modes in boundary layer. The dominant mode of boundary layer has an inhibitory action on other modes. Under continuous wave, the disturbance modes are mainly distributed near fundamental and harmonic frequencies, while under pulse wave, the disturbance modes are widely distributed in different modes. For both pulse and continuous waves, most of disturbance modes slide into a lower-growth or decay state in downstream, which is tending towards stability. The amplitude of disturbance modes in boundary layer under continuous wave is considerably larger than pulse wave. The growth rate for the former is also considerably larger than the later the disturbance modes with higher growth are mainly distributed near fundamental and harmonic frequencies for the former, while the disturbance modes are widely distributed in different frequencies for the latter.

Response of a hypersonic boundary layer to freestream pulse acoustic disturbance.

Science.gov (United States)

Wang, Zhenqing; Tang, Xiaojun; Lv, Hongqing

2014-01-01

The response of hypersonic boundary layer over a blunt wedge to freestream pulse acoustic disturbance was investigated. The stability characteristics of boundary layer for freestream pulse wave and continuous wave were analyzed comparatively. Results show that freestream pulse disturbance changes the thermal conductivity characteristics of boundary layer. For pulse wave, the number of main disturbance clusters decreases and the frequency band narrows along streamwise. There are competition and disturbance energy transfer among different modes in boundary layer. The dominant mode of boundary layer has an inhibitory action on other modes. Under continuous wave, the disturbance modes are mainly distributed near fundamental and harmonic frequencies, while under pulse wave, the disturbance modes are widely distributed in different modes. For both pulse and continuous waves, most of disturbance modes slide into a lower-growth or decay state in downstream, which is tending towards stability. The amplitude of disturbance modes in boundary layer under continuous wave is considerably larger than pulse wave. The growth rate for the former is also considerably larger than the later the disturbance modes with higher growth are mainly distributed near fundamental and harmonic frequencies for the former, while the disturbance modes are widely distributed in different frequencies for the latter.

Brain atrophy during aging

International Nuclear Information System (INIS)

Matsuzawa, Taiju; Yamada, Kenji; Yamada, Susumu; Ono, Shuichi; Takeda, Shunpei; Hatazawa, Jun; Ito, Masatoshi; Kubota, Kazuo

1985-01-01

Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT. Brain atrophy was minimal in 34-35 years old in both sexes, increased exponentially to the increasing age after 34-35 years, and probably resulted in dementia, such as vascular or multi-infarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34-35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extent of brain atrophy (20 - 30 %) existed among aged subjects. Progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was the decrease in the cerebral blood flow. We have classified brain atrophy into sulcal and cisternal enlargement type (type I), ventricular enlargement type (type II) and mixed type (type III) according to the clinical study using NMR-CT. Brain atrophy of type I progresses significantly in almost all of the geriatric disorders. This type of brain atrophy progresses significantly in heavy smokers and drinkers. Therefore this type of brain atrophy might be caused by the decline in the blood flow in anterior and middle cerebral arteries. Brain atrophy of type II was caused by the disturbance of cerebrospinal fluid circulation after cerebral bleeding and subarachnoid bleeding. Brain atrophy of type III was seen in vascular dementia or multi-infarct dementia which was caused by loss of brain matter after multiple infarction, and was seen also in dementia of Alzheimer type in which degeneration of nerve cells results in brain atrophy. NMR-CT can easily detect small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy. (J.P.N.)

[Traumatic brain injuries--forensic and expertise aspects].

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Vuleković, Petar; Simić, Milan; Misić-Pavkov, Gordana; Cigić, Tomislav; Kojadinović, Zeljko; Dilvesi, Dula

2008-01-01

Traumatic brain injuries have major socio-economic importance due to their frequency, high mortality and serious consequences. According to their nature the consequences of these injuries may be classified as neurological, psychiatric and esthetic. Various lesions of brain structures cause neurological consequences such as disturbance of motor functions, sensibility, coordination or involuntary movements, speech disturbances and other deviations, as well as epilepsy. Psychiatric consequences include cognitive deficit, emotional disturbances and behavior disturbances. CRIMINAL-LEGAL ASPECT OF TRAUMATIC BRAIN INJURIES AND LITIGATION: Criminal-legal aspect of traumatic brain injuries expertise understands the qualification of these injuries as mild, serious and qualified serious body injuries as well as the expertise about the mechanisms of their occurrence. Litigation expertise includes the estimation of pain, fear, diminished, i.e. lost vital activity and disability, esthetic marring, and psychological suffer based on the diminished general vital activity and esthetic marring. Evaluation of consequences of traumatic brain injuries should be performed only when it can be positively confirmed that they are permanent, i.e. at least one year after the injury. Expertise of these injuries is interdisciplinary. Among clinical doctors the most competent medical expert is the one who is in charge for diagnostics and injury treatment, with the recommendation to avoid, if possible, the doctor who conducted treatment. For the estimation of general vital activity, the neurological consequences, pain and esthetic marring expertise, the most competent doctors are neurosurgeon and neurologist. Psychological psychiatric consequences and fear expertise have to be performed by the psychiatrist. Specialists of forensic medicine contribute with knowledge of criminal low and legal expertise.

A case of gait disturbance caused by low-dose gabapentin

Directory of Open Access Journals (Sweden)

Kanao-Kanda M

2016-06-01

Full Text Available Megumi Kanao-Kanda, Hirotsugu Kanda, Osamu Takahata, Takayuki Kunisawa Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan Abstract: Gabapentin, an anticonvulsant agent, is now often used for the treatment of neuropathic pain all over the world. It is unclear whether the combined use of gabapentin, sodium valproate, and flunitrazepam results in enhancement of the side effect, a gait disturbance. A 60-year-old man was taking oral sodium valproate for symptomatic epilepsy after a brain contusion and flunitrazepam to relieve insomnia. Oral gabapentin therapy was started for suspected neuropathic pain. Although the initial dose of oral gabapentin (200 mg relieved the pain, the lower extremities became weak, resulting in a gait disturbance. The therapy was restarted with a halved dose, and this resolved the gait disturbance and relieved the pain. Keywords: gabapentin, gait disturbance, side effect, neuropathic pain

Neurobiological basis of parenting disturbance.

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Newman, Louise K; Harris, Melissa; Allen, Joanne

2011-02-01

It has been proposed that early attachment relationships shape the structure and reactivity of social brain structures that underlie later social capacities. We provide a review of the literature surrounding the development of neurological regulatory systems during infancy and outline recent research suggesting these systems go on to underlie adaptive parental responses. We review evidence in the peer-reviewed psychiatric literature including (i) observational human literature on the neurobiological and social sequelae of early parenting experiences, (ii) experimental animal literature on the effects of early maternal care on neurological development, (iii) experimental animal literature on the neurobiological underpinnings of parenting behaviours, (iv) observational and fMRI evidence on the neurobiological correlates of parenting behaviours, (v) functional and volumetric imaging studies on adults affected by borderline personality disorder. The development of infant regulatory systems is influenced by early parenting experiences. These frontolimbic regulatory systems are also heavily implicated in normal parental responses to infant cues. These frontolimbic disturbances are also observed in studies of borderline personality disorder; a disorder associated with poor emotional regulation, early trauma and disturbed parenting. While the current literature is limited to animal models of abnormal care giving, existing disorders associated with deficits in regulatory capacity and abnormal frontolimbic functioning may yet provide a human model of the neurobiology of parenting disturbance.

ALTERATIONS IN BRAIN CREATINE CONCENTRATIONS UNDER LONG-TERM SOCIAL ISOLATION (EXPERIMENTAL STUDY).

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Koshoridze, N; Kuchukashvili, Z; Menabde, K; Lekiashvili, Sh; Koshoridze, M

2016-02-01

Stress represents one of the main problems of modern humanity. This study was done for understanding more clearly alterations in creatine content of the brain under psycho-emotional stress induced by long-term social isolation. It was shown that under 30 days social isolation creatine amount in the brain was arisen, while decreasing concentrations of synthesizing enzymes (AGAT, GAMT) and creatine transporter protein (CrT). Another important point was that such changes were accompanied by down-regulation of creatine kinase (CK), therefore the enzyme's concentration was lowered. In addition, it was observed that content of phosphocreatine (PCr) and ATP were also reduced, thus indicating down-regulation of energy metabolism of brain that is really a crucial point for its normal functioning. To sum up the results it can be underlined that long-term social isolation has negative influence on energy metabolism of brain; and as a result reduce ATP content, while increase of free creatine concentration, supposedly maintaining maximal balance for ATP amount, but here must be also noted that up-regulated oxidative pathways might have impact on blood brain barrier, resulting on its permeability.

Trajectory Control of Scale-Free Dynamical Networks with Exogenous Disturbances

International Nuclear Information System (INIS)

Yang Hongyong; Zhang Shun; Zong Guangdeng

2011-01-01

In this paper, the trajectory control of multi-agent dynamical systems with exogenous disturbances is studied. Suppose multiple agents composing of a scale-free network topology, the performance of rejecting disturbances for the low degree node and high degree node is analyzed. Firstly, the consensus of multi-agent systems without disturbances is studied by designing a pinning control strategy on a part of agents, where this pinning control can bring multiple agents' states to an expected consensus track. Then, the influence of the disturbances is considered by developing disturbance observers, and disturbance observers based control (DOBC) are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multi-agent systems with disturbances under the composite controller can be achieved for scale-free network topology. Finally, by analyzing examples of multi-agent systems with scale-free network topology and exogenous disturbances, the verities of the results are proved. Under the DOBC with the designed parameters, the trajectory convergence of multi-agent systems is researched by pinning two class of the nodes. We have found that it has more stronger robustness to exogenous disturbances for the high degree node pinned than that of the low degree node pinned. (interdisciplinary physics and related areas of science and technology)

Sleep disorders in children with traumatic brain injury: a case of serious neglect.

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Stores, Gregory; Stores, Rachel

2013-09-01

The aim of this study was to review the basic aspects of sleep disturbance in children with traumatic brain injury (TBI). A search was performed on reports of sleep disturbances in children who had suffered TBI. Adults with TBI were also considered to anticipate the nature and significance of such disturbances in younger patients. Types of reported sleep disturbance were noted and their possible aetiology and management considered. Sleep disturbance has consistently been associated with TBI but the literature suggests that this aspect of patient care is often inadequately considered and there has been little research on the subject, especially in relation to children. Excessive daytime sleepiness is often mentioned, less so insomnia and parasomnias, but there is little information about the specific sleep disorders underlying these problems. Sleep disorders with potentially important developmental consequences have been neglected in the care of children with TBI. Screening for sleep problems should be routine and followed, if indicated, by a detailed diagnosis of the child's underlying specific sleep disorder, the possible aetiology of which includes neuropathology and potential medical, psychological, or psychiatric comorbidities. Appropriate assessments and modern treatment options are now well defined although generally underutilized. Further well-designed research is needed for which guidelines are available. © 2013 Mac Keith Press.

Sleep in childhood and adolescence: age-specific sleep characteristics, common sleep disturbances and associated difficulties.

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Barclay, Nicola L; Gregory, Alice M

2014-01-01

Sleep changes throughout the lifespan, with particularly salient alterations occurring during the first few years of life, as well as during the transition from childhood to adolescence. Such changes are partly the result of brain maturation; complex changes in the organisation of the circadian system; as well as changes in daily routine, environmental demands and responsibilities. Despite the automaticity of sleep, given that it is governed by a host of complex mechanisms, there are times when sleep becomes disturbed. Sleep disturbances in childhood are common and may stem from behavioural difficulties or abnormalities in physiological processes-and, in some cases manifest into diagnosable sleep disorders. As well as occurring exclusively, childhood sleep disturbances often co-occur with other difficulties. The purpose of this chapter is to outline the neurobiology of typical sleep/wake processes, and describe changes in sleep physiology and architecture from birth to adulthood. Furthermore, common childhood sleep disorders are described as are their associations with other traits, including all of the syndromes presented in this handbook: ASDs, ADHD, schizophrenia and emotional/behavioural difficulties. Throughout, we attempt to explain possible mechanisms underlying these disorders and their associations.

Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?

NARCIS (Netherlands)

Prinzing, A.; Dauber, J.; Hammer, E.; Hammouti, N.; Bohning-Gaese, K.

2008-01-01

Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a

Cerebral Glucose Metabolism and Sedation in Brain-injured Patients: A Microdialysis Study.

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Hertle, Daniel N; Santos, Edgar; Hagenston, Anna M; Jungk, Christine; Haux, Daniel; Unterberg, Andreas W; Sakowitz, Oliver W

2015-07-01

Disturbed brain metabolism is a signature of primary damage and/or precipitates secondary injury processes after severe brain injury. Sedatives and analgesics target electrophysiological functioning and are as such well-known modulators of brain energy metabolism. Still unclear, however, is how sedatives impact glucose metabolism and whether they differentially influence brain metabolism in normally active, healthy brain and critically impaired, injured brain. We therefore examined and compared the effects of anesthetic drugs under both critical (1 mmol/L) extracellular brain glucose levels. We performed an explorative, retrospective analysis of anesthetic drug administration and brain glucose concentrations, obtained by bedside microdialysis, in 19 brain-injured patients. Our investigations revealed an inverse linear correlation between brain glucose and both the concentration of extracellular glutamate (Pearson r=-0.58, P=0.01) and the lactate/glucose ratio (Pearson r=-0.55, P=0.01). For noncritical brain glucose levels, we observed a positive linear correlation between midazolam dose and brain glucose (Pbrain glucose levels, extracellular brain glucose was unaffected by any type of sedative. These findings suggest that the use of anesthetic drugs may be of limited value in attempts to influence brain glucose metabolism in injured brain tissue.

Developmental trajectories of brain maturation and behavior: Relevance to major mental illnesses

Directory of Open Access Journals (Sweden)

Sedona Lockhart

2018-05-01

Full Text Available Adverse events in childhood and adolescence, such as social neglect or drug abuse, are known to lead to behavioral changes in young adulthood. This is particularly true for the subset of people who are intrinsically more vulnerable to stressful conditions. Yet the underlying mechanisms for such developmental trajectory from early life insult to aberrant adult behavior remains elusive. Adolescence is a period of dynamic physiological, psychological, and behavioral changes, encompassing a distinct neurodevelopmental stage called the ‘critical period’. During adolescence, the brain is uniquely susceptible to stress. Stress mediators may lead to disturbances to biological processes that can cause permanent alterations in the adult stage, even as severe as the onset of mental illness when paired with genetic risk and environmental factors. Understanding the molecular factors governing the critical period and how stress can disturb the maturation processes will allow for better treatment and prevention of late adolescent/young adult onset psychiatric disorders. Keywords: Adolescence, Critical period, Developmental trajectory, Brain maturation, Adult behavior

Fixed position holding control for self-propulsion barges under disturbance condition; Gairanka ni okeru jiko baji no teiten hoji seigyo ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Kijima, K; Murata, W; Furukawa, Y [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1996-04-10

In direct hoisting work in suspension bridge construction, since a cable crane directly hoists a bridge beam block put on a barge on the sea, precise fixed position holding function is required for a barge. The control system was then designed on the basis of an ILQ control theory, and the effect of change in time constant as design parameter on fixed position holding performance was studied. In addition, the critical disturbance for fixed position holding control was studied through numerical simulation under various disturbance conditions using the above designed control system. As a result, in the design of control systems on the basis of an ILQ control theory, the precise control system could be designed by diminishing, in particular, the time constant for state variable around a z axis among time constants according to the extent of disturbance. The control performance was largely affected by response delay period from sensing of disturbance to beginning of control. 3 refs., 7 figs., 2 tabs.

Modulating conscious movement intention by noninvasive brain stimulation and the underlying neural mechanisms.

Science.gov (United States)

Douglas, Zachary H; Maniscalco, Brian; Hallett, Mark; Wassermann, Eric M; He, Biyu J

2015-05-06

Conscious intention is a fundamental aspect of the human experience. Despite long-standing interest in the basis and implications of intention, its underlying neurobiological mechanisms remain poorly understood. Using high-definition transcranial DC stimulation (tDCS), we observed that enhancing spontaneous neuronal excitability in both the angular gyrus and the primary motor cortex caused the reported time of conscious movement intention to be ∼60-70 ms earlier. Slow brain waves recorded ∼2-3 s before movement onset, as well as hundreds of milliseconds after movement onset, independently correlated with the modulation of conscious intention by brain stimulation. These brain activities together accounted for 81% of interindividual variability in the modulation of movement intention by brain stimulation. A computational model using coupled leaky integrator units with biophysically plausible assumptions about the effect of tDCS captured the effects of stimulation on both neural activity and behavior. These results reveal a temporally extended brain process underlying conscious movement intention that spans seconds around movement commencement. Copyright © 2015 Douglas et al.

Smith predictor-based multiple periodic disturbance compensation for long dead-time processes

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Tan, Fang; Li, Han-Xiong; Shen, Ping

2018-05-01

Many disturbance rejection methods have been proposed for processes with dead-time, while these existing methods may not work well under multiple periodic disturbances. In this paper, a multiple periodic disturbance rejection is proposed under the Smith predictor configuration for processes with long dead-time. One feedback loop is added to compensate periodic disturbance while retaining the advantage of the Smith predictor. With information of the disturbance spectrum, the added feedback loop can remove multiple periodic disturbances effectively. The robust stability can be easily maintained through the rigorous analysis. Finally, simulation examples demonstrate the effectiveness and robustness of the proposed method for processes with long dead-time.

Pacing and awareness: brain regulation of physical activity.

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Edwards, A M; Polman, R C J

2013-11-01

The aim of this current opinion article is to provide a contemporary perspective on the role of brain regulatory control of paced performances in response to exercise challenges. There has been considerable recent conjecture as to the role of the brain during exercise, and it is now broadly accepted that fatigue does not occur without brain involvement and that all voluntary activity is likely to be paced at some level by the brain according to individualised priorities and knowledge of personal capabilities. This article examines the role of pacing in managing and distributing effort to successfully accomplish physical tasks, while extending existing theories on the role of the brain as a central controller of performance. The opinion proposed in this article is that a central regulator operates to control exercise performance but achieves this without the requirement of an intelligent central governor located in the subconscious brain. It seems likely that brain regulation operates at different levels of awareness, such that minor homeostatic challenges are addressed automatically without conscious awareness, while larger metabolic disturbances attract conscious awareness and evoke a behavioural response. This supports the view that the brain regulates exercise performance but that the interpretation of the mechanisms underlying this effect have not yet been fully elucidated.

Increased Sleep Need and Reduction of Tuberomammillary Histamine Neurons after Rodent Traumatic Brain Injury.

Science.gov (United States)

Noain, Daniela; Büchele, Fabian; Schreglmann, Sebastian R; Valko, Philipp O; Gavrilov, Yuri V; Morawska, Marta M; Imbach, Lukas L; Baumann, Christian R

2018-01-01

Although sleep-wake disturbances are prevalent and well described after traumatic brain injury, their pathophysiology remains unclear, most likely because human traumatic brain injury is a highly heterogeneous entity that makes the systematic study of sleep-wake disturbances in relation to trauma-induced histological changes a challenging task. Despite increasing interest, specific and effective treatment strategies for post-traumatic sleep-wake disturbances are still missing. With the present work, therefore, we aimed at studying acute and chronic sleep-wake disturbances by electrophysiological means, and at assessing their histological correlates after closed diffuse traumatic brain injury in rats with the ultimate goal of generating a model of post-traumatic sleep-wake disturbances and associated histopathological findings that accurately represents the human condition. We assessed sleep-wake behavior by means of standard electrophysiological recordings before and 1, 7, and 28 days after sham or traumatic brain injury procedures. Sleep-wake findings were then correlated to immunohistochemically labeled and stereologically quantified neuronal arousal systems. Compared with control animals, we found that closed diffuse traumatic brain injury caused increased sleep need one month after trauma, and sleep was more consolidated. As histological correlate, we found a reduced number of histamine immunoreactive cells in the tuberomammillary nucleus, potentially related to increased neuroinflammation. Monoaminergic and hypocretinergic neurotransmitter systems in the hypothalamus and rostral brainstem were not affected, however. These results suggest that our rat traumatic brain injury model reflects human post-traumatic sleep-wake disturbances and associated histopathological findings very accurately, thus providing a study platform for novel treatment strategies for affected patients.

Sleep disturbance induces neuroinflammation and impairment of learning and memory.

Science.gov (United States)

Zhu, Biao; Dong, Yuanlin; Xu, Zhipeng; Gompf, Heinrich S; Ward, Sarah A P; Xue, Zhanggang; Miao, Changhong; Zhang, Yiying; Chamberlin, Nancy L; Xie, Zhongcong

2012-12-01

Hospitalized patients can develop cognitive function decline, the mechanisms of which remain largely to be determined. Sleep disturbance often occurs in hospitalized patients, and neuroinflammation can induce learning and memory impairment. We therefore set out to determine whether sleep disturbance can induce neuroinflammation and impairment of learning and memory in rodents. Five to 6-month-old wild-type C57BL/6J male mice were used in the studies. The mice were placed in rocking cages for 24 h, and two rolling balls were present in each cage. The mice were tested for learning and memory function using the Fear Conditioning Test one and 7 days post-sleep disturbance. Neuroinflammation in the mouse brain tissues was also determined. Of the Fear Conditioning studies at one day and 7 days after sleep disturbance, twenty-four hour sleep disturbance decreased freezing time in the context test, which assesses hippocampus-dependent learning and memory; but not the tone test, which assesses hippocampus-independent learning and memory. Sleep disturbance increased pro-inflammatory cytokine IL-6 levels and induced microglia activation in the mouse hippocampus, but not the cortex. These results suggest that sleep disturbance induces neuroinflammation in the mouse hippocampus, and impairs hippocampus-dependent learning and memory in mice. Pending further studies, these findings suggest that sleep disturbance-induced neuroinflammation and impairment of learning and memory may contribute to the development of cognitive function decline in hospitalized patients. Copyright © 2012 Elsevier Inc. All rights reserved.

Using perturbations to identify the brain circuits underlying active vision.

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Wurtz, Robert H

2015-09-19

The visual and oculomotor systems in the brain have been studied extensively in the primate. Together, they can be regarded as a single brain system that underlies active vision--the normal vision that begins with visual processing in the retina and extends through the brain to the generation of eye movement by the brainstem. The system is probably one of the most thoroughly studied brain systems in the primate, and it offers an ideal opportunity to evaluate the advantages and disadvantages of the series of perturbation techniques that have been used to study it. The perturbations have been critical in moving from correlations between neuronal activity and behaviour closer to a causal relation between neuronal activity and behaviour. The same perturbation techniques have also been used to tease out neuronal circuits that are related to active vision that in turn are driving behaviour. The evolution of perturbation techniques includes ablation of both cortical and subcortical targets, punctate chemical lesions, reversible inactivations, electrical stimulation, and finally the expanding optogenetic techniques. The evolution of perturbation techniques has supported progressively stronger conclusions about what neuronal circuits in the brain underlie active vision and how the circuits themselves might be organized.

Functional brain imaging to investigate the higher brain dysfunction induced by diffuse brain injury

International Nuclear Information System (INIS)

Nariai, Tadashi; Inaji, Motoki; Ohno, Kikuo; Hiura, Mikio; Ishii, Kenji; Hosoda, Chihiro

2011-01-01

Higher brain dysfunction is the major problem of patients who recover from neurotrauma the prevents them from returning to their previous social life. Many such patients do not have focal brain damage detected with morphological imaging. We focused on studying the focal brain dysfunction that can be detected only with functional imaging with positron emission tomography (PET) in relation to the score of various cognition batteries. Patients who complain of higher brain dysfunction without apparent morphological cortical damage were recruited for this study. Thirteen patients with diffuse axonal injury (DAI) or cerebral concussion was included. They underwent a PET study to image glucose metabolism by 18 F-fluorodeoxyglucose (FDG), and central benodiazepine receptor (cBZD-R) (marker of neuronal body) by 11 C-flumazenil, together with cognition measurement by WAIS-R, WMS-R, and WCST etc. PET data were compared with age matched normal controls using statistical parametric mapping (SPM)2. DAI patients had a significant decrease in glucose matabolism and cBZD-R distribution in the cingulated cortex than normal controls. Patients diagnosed with concussion because of shorter consciousness disturbance also had abnormal FDG uptake and cBZD-R distribution. Cognition test scores were variable among patients. Degree of decreased glucose metabolism and cBZD-R distribution in the dominant hemishphere corresponded well to the severity of cognitive disturbance. PET molecular imaging was useful to depict focal cortical dysfunction of neurotrauma patients even when morphological change was not apparent. This method may be promising to clarify the pathophysiology of higher brain dysfunction of patients with diffuse axonal injury or chronic traumatic encephalopathy. (author)

Disturbance regimes and the historical range and variation in terrestrial ecosystems

Science.gov (United States)

Robert Keane

2017-01-01

Disturbances are major drivers of ecological dynamics and it is the cumulative effects of disturbances across space and time that define a disturbance regime and dictate biodiversity by influencing the ranges of vegetation structures, compositions, and processes on landscapes. This range and variation of landscape characteristics under historical disturbance regimes...

Segmental sensory disturbance in brain stem infarctions of the lateral lower pons and lateral medulla

International Nuclear Information System (INIS)

Matsumoto, Sadayuki; Yamasaki, Masahiro; Maya, Kiyomi; Imai, Terukuni; Okuda, Bungo.

1987-01-01

We reported on seven cases of brainstem infarctions of the lateral lower pons and lateral medulla, the sensory deficit manifested over the trunk or the leg namely segmental sensory disturbances. All patients showed dissociated sensory disturbance of pain and temperature with retained deep sensations except two cases in which touch was also slightly impaired. The sensory distribution was classified into two types. The first ''crossed type'', ipsilatral face and contralateral trunk and leg below the level was involved in 4 cases, and the second ''unilateral type'' contralateral face and trunk above the level in 3 cases. Clinico-anatomical evaluation was executed by MRI. Lesions were detected in the lateral lower pons in two cases and in the lateral medulla in one case. The location of lesions by MRI revealed more lateral lesions showed ''crossed type'' of segmental sensory disturbance and more medial lesions ''unilateral type''. It was shown that the segmental sensory disturbance could be explained by the partial involvement of the lateral spinothalamic tract, which is arranged with the fibers from the sacral segments most lateral. We considered it very important to differentiate the segmental sensory disturbance by brainstem lesion in practical clinical diagnosis. We also emphasize the type of segmental sensory disturbance could be a localizing sign in the lateral brainstem as such, ''crossed type'' indicating the lesion of the lateral portion and ''unilateral type'' the medial portion of the lateral lower brainstem. (author)

Corticonic models of brain mechanisms underlying cognition and intelligence

Science.gov (United States)

Farhat, Nabil H.

underlying intelligence and other higher level brain functions.

Age-related similarities and differences in brain activity underlying reversal learning

Directory of Open Access Journals (Sweden)

Kaoru eNashiro

2013-05-01

Full Text Available The ability to update associative memory is an important aspect of episodic memory and a critical skill for social adaptation. Previous research with younger adults suggests that emotional arousal alters brain mechanisms underlying memory updating; however, it is unclear whether this applies to older adults. Given that the ability to update associative information declines with age, it is important to understand how emotion modulates the brain processes underlying memory updating in older adults. The current study investigated this question using reversal learning tasks, where younger and older participants (age ranges 19-35 and 61-78 respectively learn a stimulus–outcome association and then update their response when contingencies change. We found that younger and older adults showed similar patterns of activation in the frontopolar OFC and the amygdala during emotional reversal learning. In contrast, when reversal learning did not involve emotion, older adults showed greater parietal cortex activity than did younger adults. Thus, younger and older adults show more similarities in brain activity during memory updating involving emotional stimuli than during memory updating not involving emotional stimuli.

Robust consensus algorithm for multi-agent systems with exogenous disturbances under convergence conditions

Science.gov (United States)

Jiang, Yulian; Liu, Jianchang; Tan, Shubin; Ming, Pingsong

2014-09-01

In this paper, a robust consensus algorithm is developed and sufficient conditions for convergence to consensus are proposed for a multi-agent system (MAS) with exogenous disturbances subject to partial information. By utilizing H∞ robust control, differential game theory and a design-based approach, the consensus problem of the MAS with exogenous bounded interference is resolved and the disturbances are restrained, simultaneously. Attention is focused on designing an H∞ robust controller (the robust consensus algorithm) based on minimisation of our proposed rational and individual cost functions according to goals of the MAS. Furthermore, sufficient conditions for convergence of the robust consensus algorithm are given. An example is employed to demonstrate that our results are effective and more capable to restrain exogenous disturbances than the existing literature.

Imaging of Brain Connectivity in Dementia: Clinical Implications for Diagnosis of its Underlying Diseases

NARCIS (Netherlands)

R. Meijboom (Rozanna)

2017-01-01

markdownabstractIn this thesis we investigated the use of advanced magnetic resonance imaging (MRI) techniques in identifying subtle brain abnormalities, associating brain abnormalities with disease symptomatology, and improving early (differential) diagnosis in several diseases underlying dementia.

Reward-Related Ventral Striatum Activity Buffers against the Experience of Depressive Symptoms Associated with Sleep Disturbances.

Science.gov (United States)

Avinun, Reut; Nevo, Adam; Knodt, Annchen R; Elliott, Maxwell L; Radtke, Spenser R; Brigidi, Bartholomew D; Hariri, Ahmad R

2017-10-04

Sleep disturbances represent one risk factor for depression. Reward-related brain function, particularly the activity of the ventral striatum (VS), has been identified as a potential buffer against stress-related depression. We were therefore interested in testing whether reward-related VS activity would moderate the effect of sleep disturbances on depression in a large cohort of young adults. Data were available from 1129 university students (mean age 19.71 ± 1.25 years; 637 women) who completed a reward-related functional MRI task to assay VS activity and provided self-reports of sleep using the Pittsburgh Sleep Quality Index and symptoms of depression using a summation of the General Distress/Depression and Anhedonic Depression subscales of the Mood and Anxiety Symptoms Questionnaire-short form. Analyses revealed that as VS activity increased the association between sleep disturbances and depressive symptoms decreased. The interaction between sleep disturbances and VS activity was robust to the inclusion of sex, age, race/ethnicity, past or present clinical disorder, early and recent life stress, and anxiety symptoms, as well as the interactions between VS activity and early or recent life stress as covariates. We provide initial evidence that high reward-related VS activity may buffer against depressive symptoms associated with poor sleep. Our analyses help advance an emerging literature supporting the importance of individual differences in reward-related brain function as a potential biomarker of relative risk for depression. SIGNIFICANCE STATEMENT Sleep disturbances are a common risk factor for depression. An emerging literature suggests that reward-related activity of the ventral striatum (VS), a brain region critical for motivation and goal-directed behavior, may buffer against the effect of negative experiences on the development of depression. Using data from a large sample of 1129 university students we demonstrate that as reward-related VS activity

Circadian Rhythm Disturbances in Mood Disorders: Insights into the Role of the Suprachiasmatic Nucleus

Science.gov (United States)

2017-01-01

Circadian rhythm disturbances are a common symptom among individuals with mood disorders. The suprachiasmatic nucleus (SCN), in the ventral part of the anterior hypothalamus, orchestrates physiological and behavioral circadian rhythms. The SCN consists of self-sustaining oscillators and receives photic and nonphotic cues, which entrain the SCN to the external environment. In turn, through synaptic and hormonal mechanisms, the SCN can drive and synchronize circadian rhythms in extra-SCN brain regions and peripheral tissues. Thus, genetic or environmental perturbations of SCN rhythms could disrupt brain regions more closely related to mood regulation and cause mood disturbances. Here, we review clinical and preclinical studies that provide evidence both for and against a causal role for the SCN in mood disorders. PMID:29230328

Designing a capacitated multi-configuration logistics network under disturbances and parameter uncertainty: a real-world case of a drug supply chain

Science.gov (United States)

Shishebori, Davood; Babadi, Abolghasem Yousefi

2018-03-01

This study investigates the reliable multi-configuration capacitated logistics network design problem (RMCLNDP) under system disturbances, which relates to locating facilities, establishing transportation links, and also allocating their limited capacities to the customers conducive to provide their demand on the minimum expected total cost (including locating costs, link constructing costs, and also expected costs in normal and disturbance conditions). In addition, two types of risks are considered; (I) uncertain environment, (II) system disturbances. A two-level mathematical model is proposed for formulating of the mentioned problem. Also, because of the uncertain parameters of the model, an efficacious possibilistic robust optimization approach is utilized. To evaluate the model, a drug supply chain design (SCN) is studied. Finally, an extensive sensitivity analysis was done on the critical parameters. The obtained results show that the efficiency of the proposed approach is suitable and is worthwhile for analyzing the real practical problems.

Memory and learning disturbances in multiple sclerosis

International Nuclear Information System (INIS)

Izquierdo, Guillermo; Mir, Jordi; Gonzalez, Manuel; Martinez-Parra, Carlos; Campoy, Francisco Jr

1991-01-01

Thirty-five patients with definite multiple sclerosis (MS) were studied. They underwent neuropsychological testing and magnetic resonance imaging (MRI). The MRI findings at different brain areas levels were compared with the neuropsychological findings. A quantitative system was used to measure MRI-MS lesions. In this series, a positive correlation was established between memory and learning disturbances measured by Battery 144, and the lesions measured by MRI (total, hemispheric and , particularly, periventricular lesions). MRI can detect MS lesions, and this study shows that a correlation between MRI and neuropsychological findings is possible if quantitative methods are used to distinguish different MS involvement areas in relation to neuropsychological tasks. These findings suggest that hemispheric lesions in MS produce cognitive disturbances and MRI could be a useful tool in predicting memory and learning impairment. (author). 20 refs.; 1 fig.; 2 tabs

Radiation-induced apoptosis and developmental disturbance of the brain

Energy Technology Data Exchange (ETDEWEB)

Inouye, Minoru [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine

1995-03-01

The developing mammalian brain is highly susceptible to ionizing radiation. A significant increase in small head size and mental retardation has been noted in prenatally exposed survivors of the atomic bombing, with the highest risk in those exposed during 8-15 weeks after fertilization. This stage corresponds to day 13 of pregnancy for mice and day 15 for rats in terms of brain development. The initial damage produced by radiation at this stage is cell death in the ventricular zone (VZ) of the brain mantle, the radiosensitive germinal cell population. During histogenesis of the cerebellum the external granular layer (EGL) is also radiosensitive. Although extensive cell death results in microcephaly and histological abnormlity, both VZ and EGL have an ability to recover from a considerable cell loss and form the normal structure of the central nervous system. The number of cell deaths to induce tissue abnormalities in adult brain rises in the range of 15-25% of the germinal cell population; and the threshold doses are about 0.3 Gy for cerebral defects and 1 Gy for cerebellar anomalies in both mice and rats. A similar threshold level is suggested in human cases in induction of mental retardation. Radiation-induced cell death in the VZ and EGL has been revealed as apoptosis, by the nuclear and cytoplasmic condensation, transglutaminase activation, required macromolecular synthesis, and internucleosomal DNA cleavage. Apoptosis of the germinal cell is assumed to eliminate acquired genetic damage. Once an abnormality in DNA has been induced and fixed in a germinal cell, it would be greatly amplified during future proliferation. These cells would commit suicide when injured for replacement by healthy cells, rather than undertake DNA repair. In fact they show very slow repair of cellular damage. Thus the high sensitivity of undifferentiated neural cells to the lethal effect of radiation may constitute a biological defense mechanism. (author) 69 refs.

Radiation-induced apoptosis and developmental disturbance of the brain

International Nuclear Information System (INIS)

Inouye, Minoru

1995-01-01

The developing mammalian brain is highly susceptible to ionizing radiation. A significant increase in small head size and mental retardation has been noted in prenatally exposed survivors of the atomic bombing, with the highest risk in those exposed during 8-15 weeks after fertilization. This stage corresponds to day 13 of pregnancy for mice and day 15 for rats in terms of brain development. The initial damage produced by radiation at this stage is cell death in the ventricular zone (VZ) of the brain mantle, the radiosensitive germinal cell population. During histogenesis of the cerebellum the external granular layer (EGL) is also radiosensitive. Although extensive cell death results in microcephaly and histological abnormlity, both VZ and EGL have an ability to recover from a considerable cell loss and form the normal structure of the central nervous system. The number of cell deaths to induce tissue abnormalities in adult brain rises in the range of 15-25% of the germinal cell population; and the threshold doses are about 0.3 Gy for cerebral defects and 1 Gy for cerebellar anomalies in both mice and rats. A similar threshold level is suggested in human cases in induction of mental retardation. Radiation-induced cell death in the VZ and EGL has been revealed as apoptosis, by the nuclear and cytoplasmic condensation, transglutaminase activation, required macromolecular synthesis, and internucleosomal DNA cleavage. Apoptosis of the germinal cell is assumed to eliminate acquired genetic damage. Once an abnormality in DNA has been induced and fixed in a germinal cell, it would be greatly amplified during future proliferation. These cells would commit suicide when injured for replacement by healthy cells, rather than undertake DNA repair. In fact they show very slow repair of cellular damage. Thus the high sensitivity of undifferentiated neural cells to the lethal effect of radiation may constitute a biological defense mechanism. (author) 69 refs

Brain network response underlying decisions about abstract reinforcers.

Science.gov (United States)

Mills-Finnerty, Colleen; Hanson, Catherine; Hanson, Stephen Jose

2014-12-01

Decision making studies typically use tasks that involve concrete action-outcome contingencies, in which subjects do something and get something. No studies have addressed decision making involving abstract reinforcers, where there are no action-outcome contingencies and choices are entirely hypothetical. The present study examines these kinds of choices, as well as whether the same biases that exist for concrete reinforcer decisions, specifically framing effects, also apply during abstract reinforcer decisions. We use both General Linear Model as well as Bayes network connectivity analysis using the Independent Multi-sample Greedy Equivalence Search (IMaGES) algorithm to examine network response underlying choices for abstract reinforcers under positive and negative framing. We find for the first time that abstract reinforcer decisions activate the same network of brain regions as concrete reinforcer decisions, including the striatum, insula, anterior cingulate, and VMPFC, results that are further supported via comparison to a meta-analysis of decision making studies. Positive and negative framing activated different parts of this network, with stronger activation in VMPFC during negative framing and in DLPFC during positive, suggesting different decision making pathways depending on frame. These results were further clarified using connectivity analysis, which revealed stronger connections between anterior cingulate, insula, and accumbens during negative framing compared to positive. Taken together, these results suggest that not only do abstract reinforcer decisions rely on the same brain substrates as concrete reinforcers, but that the response underlying framing effects on abstract reinforcers also resemble those for concrete reinforcers, specifically increased limbic system connectivity during negative frames. Copyright © 2014 Elsevier Inc. All rights reserved.

[Metronidazole-Induced Encephalopathy during Brain Abscess Treatment:Two Case Reports].

Science.gov (United States)

Yokoyama, Yuka; Asaoka, Katsuyuki; Sugiyama, Taku; Uchida, Kazuki; Shimbo, Daisuke; Kobayashi, Satoshi; Itamoto, Koji

2015-10-01

Metronidazole is a widely used antibiotic against anaerobic bacteria and protozoa. We report two cases of metronidazole-induced encephalopathy(MIE)during treatment of a brain abscess with metronidazole. The patients developed mental disturbance, and brain MRI showed reversible signals on DWI, FLAIR, and T2. Case 1: A 48-year-old woman was admitted to our hospital with a cerebellar abscess. We initiated treatment with oral metronidazole. After taking the medication, she developed mental disturbance, and her brain MRI showed a hyperintensity within the corpus callosum. We suspected metronidazole toxicity and discontinued metronidazole treatment. The symptoms resolved rapidly within a week, and the hyperintensity on the MRI disappeared. Case 2: A 22-year-old man was admitted to our hospital with a brain abscess. We initiated treatment with oral metronidazole. On day 38, he developed mental disturbance, and his MRI showed hyperintensities within the bilateral dentate nuclei and corpus callosum. These symptoms were consistent with MIE. After cessation of metronidazole, his symptoms and abnormal MRI signals completely disappeared.

History of aphasia: From brain to language

NARCIS (Netherlands)

Eling, P.A.T.M.; Whitaker, H.A.; Finger, S.; Boller, F.; Tyler, K.L.

2009-01-01

An historical overview is presented that focuses on the changes both in approach and topics with respect to language disturbances due to brain lesions. Early cases of language disorders were described without any theorizing about language or its relation to the brain. Also, three forms of speech

Sleep disturbance in mental health problems and neurodegenerative disease

Directory of Open Access Journals (Sweden)

Anderson KN

2013-05-01

Full Text Available Kirstie N Anderson1 Andrew J Bradley2,3 1Department of Neurology, Newcastle Upon Tyne Hospitals NHS Trust, Newcastle Upon Tyne, UK; 2Eli Lilly and Company Limited, Lilly House, Basingstoke, UK; 3Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, UK Abstract: Sleep has been described as being of the brain, by the brain, and for the brain. This fundamental neurobiological behavior is controlled by homeostatic and circadian (24-hour processes and is vital for normal brain function. This review will outline the normal sleep–wake cycle, the changes that occur during aging, and the specific patterns of sleep disturbance that occur in association with both mental health disorders and neurodegenerative disorders. The role of primary sleep disorders such as insomnia, obstructive sleep apnea, and REM sleep behavior disorder as potential causes or risk factors for particular mental health or neurodegenerative problems will also be discussed. Keywords: sleep, mental health, neurodegenerative disorders, cognition

Implications of recurrent disturbance for genetic diversity.

Science.gov (United States)

Davies, Ian D; Cary, Geoffrey J; Landguth, Erin L; Lindenmayer, David B; Banks, Sam C

2016-02-01

Exploring interactions between ecological disturbance, species' abundances and community composition provides critical insights for ecological dynamics. While disturbance is also potentially an important driver of landscape genetic patterns, the mechanisms by which these patterns may arise by selective and neutral processes are not well-understood. We used simulation to evaluate the relative importance of disturbance regime components, and their interaction with demographic and dispersal processes, on the distribution of genetic diversity across landscapes. We investigated genetic impacts of variation in key components of disturbance regimes and spatial patterns that are likely to respond to climate change and land management, including disturbance size, frequency, and severity. The influence of disturbance was mediated by dispersal distance and, to a limited extent, by birth rate. Nevertheless, all three disturbance regime components strongly influenced spatial and temporal patterns of genetic diversity within subpopulations, and were associated with changes in genetic structure. Furthermore, disturbance-induced changes in temporal population dynamics and the spatial distribution of populations across the landscape resulted in disrupted isolation by distance patterns among populations. Our results show that forecast changes in disturbance regimes have the potential to cause major changes to the distribution of genetic diversity within and among populations. We highlight likely scenarios under which future changes to disturbance size, severity, or frequency will have the strongest impacts on population genetic patterns. In addition, our results have implications for the inference of biological processes from genetic data, because the effects of dispersal on genetic patterns were strongly mediated by disturbance regimes.

Magnetic resonance imaging based noninvasive measurements of brain hemodynamics in neonates

DEFF Research Database (Denmark)

De Vis, Jill B; Alderliesten, Thomas; Hendrikse, Jeroen

2016-01-01

Perinatal disturbances of brain hemodynamics can have a detrimental effect on the brain's parenchyma with consequently adverse neurodevelopmental outcome. Noninvasive, reliable tools to evaluate the neonate's brain hemodynamics are scarce. Advances in magnetic resonance imaging have provided new...

Electric field versus neutral wind control of the equatorial anomaly under quiet and disturbed condition: A global perspective from SUNDIAL 86

International Nuclear Information System (INIS)

Abdu, M.A.; Sobral, J.H.A.; Trivedi, N.B.; Reddy, B.M.; Fejer, B.G.; Szuszczewicz, E.P.; Walker, G.O.; Kikuchi, T.

1990-01-01

Developments of equatorial Ionization Anomaly (EIA) under quiescent and disturbed ionospheric conditions are investigated using the data collected from the low-latitude network of ionosondes and magnetometers operated at different longitude sectors of the globe as a part of the SUNDIAL 86 campaign (22 September to 3 October, 1986). Based on case studies of EIA developments, attention is focused on identifiying the EIA response to changes in the electric fields associated with the equatorial electrojet and counter electrojet events. The response time of the EIA to electric field changes is found to vary from 2.5 to 4 h. An anomalous EIA development observed in the morning sector on September 23 suggested possible electric field penetration to low latitude during a substorm energy storage/Dst development phase. The analysis also shows that the afternoon EIA could be inhibited due to equatorward blowing disturbed neutral winds. The results of the present analysis emphasize the need for pursuing further investigations for the response of EIA to magnetosphere-induced disturbances

Brain Regions Underlying Word Finding Difficulties in Temporal Lobe Epilepsy

Science.gov (United States)

Trebuchon-Da Fonseca, Agnes; Guedj, Eric; Alario, F-Xavier; Laguitton, Virginie; Mundler, Olivier; Chauvel, Patrick; Liegeois-Chauvel, Catherine

2009-01-01

Word finding difficulties are often reported by epileptic patients with seizures originating from the language dominant cerebral hemisphere, for example, in temporal lobe epilepsy. Evidence regarding the brain regions underlying this deficit comes from studies of peri-operative electro-cortical stimulation, as well as post-surgical performance.…

Disturbance hydrology: Preparing for an increasingly disturbed future

Science.gov (United States)

Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

2017-01-01

This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre- and post-disturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

Model reduction of nonlinear systems subject to input disturbances

KAUST Repository

Ndoye, Ibrahima; Laleg-Kirati, Taous-Meriem

2017-01-01

The method of convex optimization is used as a tool for model reduction of a class of nonlinear systems in the presence of disturbances. It is shown that under some conditions the nonlinear disturbed system can be approximated by a reduced order

PSO-based PID Speed Control of Traveling Wave Ultrasonic Motor under Temperature Disturbance

Science.gov (United States)

Arifin Mat Piah, Kamal; Yusoff, Wan Azhar Wan; Azmi, Nur Iffah Mohamed; Romlay, Fadhlur Rahman Mohd

2018-03-01

Traveling wave ultrasonic motors (TWUSMs) have a time varying dynamics characteristics. Temperature rise in TWUSMs remains a problem particularly in sustaining optimum speed performance. In this study, a PID controller is used to control the speed of TWUSM under temperature disturbance. Prior to developing the controller, a linear approximation model which relates the speed to the temperature is developed based on the experimental data. Two tuning methods are used to determine PID parameters: conventional Ziegler-Nichols(ZN) and particle swarm optimization (PSO). The comparison of speed control performance between PSO-PID and ZN-PID is presented. Modelling, simulation and experimental work is carried out utilizing Fukoku-Shinsei USR60 as the chosen TWUSM. The results of the analyses and experimental work reveal that PID tuning using PSO-based optimization has the advantage over the conventional Ziegler-Nichols method.

Therapeutic brain modulation with targeted large neutral amino acid supplements in the Pah-enu2 phenylketonuria mouse model.

Science.gov (United States)

van Vliet, Danique; Bruinenberg, Vibeke M; Mazzola, Priscila N; van Faassen, Martijn Hjr; de Blaauw, Pim; Pascucci, Tiziana; Puglisi-Allegra, Stefano; Kema, Ido P; Heiner-Fokkema, M Rebecca; van der Zee, Eddy A; van Spronsen, Francjan J

2016-11-01

Phenylketonuria treatment consists mainly of a Phe-restricted diet, which leads to suboptimal neurocognitive and psychosocial outcomes. Supplementation of large neutral amino acids (LNAAs) has been suggested as an alternative dietary treatment strategy to optimize neurocognitive outcome in phenylketonuria and has been shown to influence 3 brain pathobiochemical mechanisms in phenylketonuria, but its optimal composition has not been established. In order to provide additional pathobiochemical insight and develop optimal LNAA treatment, several targeted LNAA supplements were investigated with respect to all 3 biochemical disturbances underlying brain dysfunction in phenylketonuria. Pah-enu2 (PKU) mice received 1 of 5 different LNAA-supplemented diets beginning at postnatal day 45. Control groups included phenylketonuria mice receiving an isonitrogenic and isocaloric high-protein diet or the AIN-93M diet, and wild-type mice receiving the AIN-93M diet. After 6 wk, brain and plasma amino acid profiles and brain monoaminergic neurotransmitter concentrations were measured. Brain Phe concentrations were most effectively reduced by supplementation of LNAAs, such as Leu and Ile, with a strong affinity for the LNAA transporter type 1. Brain non-Phe LNAAs could be restored on supplementation, but unbalanced LNAA supplementation further reduced brain concentrations of those LNAAs that were not (sufficiently) included in the LNAA supplement. To optimally ameliorate brain monoaminergic neurotransmitter concentrations, LNAA supplementation should include Tyr and Trp together with LNAAs that effectively reduce brain Phe concentrations. The requirement for Tyr supplementation is higher than it is for Trp, and the relative effect of brain Phe reduction is higher for serotonin than it is for dopamine and norepinephrine. The study shows that all 3 biochemical disturbances underlying brain dysfunction in phenylketonuria can be targeted by specific LNAA supplements. The study thus

Disturbing forest disturbances

Energy Technology Data Exchange (ETDEWEB)

Volney, W.J.A.; Hirsch, K.G. [Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB (Canada)

2005-10-01

This paper described the role that disturbances play in maintaining the ecological integrity of Canadian boreal forests. Potential adaptation options to address the challenges that these disturbances present were also examined. Many forest ecosystems need fire for regeneration, while other forests rely on a cool, wet disintegration process driven by insects and commensal fungi feeding on trees to effect renewal. While there are characteristic natural, temporal and spatial patterns to these disturbances, recent work has demonstrated that the disturbances are being perturbed by climatic change that has been compounded by anthropogenic disturbances in forests. Fire influences species composition and age structure, regulates forest insects and diseases, affects nutrient cycling and energy fluxes, and maintains the productivity of different habitats. Longer fire seasons as a result of climatic change will lead to higher intensity fires that may more easily evade initial attacks and become problematic. Fire regimes elevated beyond the range of natural variation will have a dramatic effect on the regional distribution and functioning of forest ecosystems and pose a threat to the safety and prosperity of people. While it was acknowledged that if insect outbreaks were to be controlled on the entire forest estate, the productivity represented by dead wood would be lost, it was suggested that insects such as the forest tent caterpillar and the spruce bud worm may also pose a greater threat as the climate gets warmer and drier. Together with fungal associates, saproxylic arthropods are active in nutrient cycling and ultimately determine the fertility of forest sites. It was suggested that the production of an age class structure and forest mosaic would render the forest landscape less vulnerable to the more negative aspects of climate change on vegetation response. It was concluded that novel management design paradigms are needed to successfully reduce the risk from threats

Neurobiology Underlying Fibromyalgia Symptoms

Directory of Open Access Journals (Sweden)

Marta Ceko

2012-01-01

Full Text Available Fibromyalgia is characterized by chronic widespread pain, clinical symptoms that include cognitive and sleep disturbances, and other abnormalities such as increased sensitivity to painful stimuli, increased sensitivity to multiple sensory modalities, and altered pain modulatory mechanisms. Here we relate experimental findings of fibromyalgia symptoms to anatomical and functional brain changes. Neuroimaging studies show augmented sensory processing in pain-related areas, which, together with gray matter decreases and neurochemical abnormalities in areas related to pain modulation, supports the psychophysical evidence of altered pain perception and inhibition. Gray matter decreases in areas related to emotional decision making and working memory suggest that cognitive disturbances could be related to brain alterations. Altered levels of neurotransmitters involved in sleep regulation link disordered sleep to neurochemical abnormalities. Thus, current evidence supports the view that at least some fibromyalgia symptoms are associated with brain dysfunctions or alterations, giving the long-held “it is all in your head” view of the disorder a new meaning.

Speech and Language Disturbances in Neurology Practice

Directory of Open Access Journals (Sweden)

Oğuz Tanrıdağ

2009-12-01

Full Text Available Despite the well-known facts discerned from interesting cases of speech and language disturbances over thousands of years, the scientific background and the limitless discussions for nearly 150 years, this field has been considered one of the least important subjects in neurological sciences. In this review, we first analyze the possible causes for this “stepchild” attitude towards this subject and we then summarize the practical aspects concerning speech and language disturbances. Our underlying expectation with this review is to explain the facts concerning those disturbances that might offer us opportunities to better understand the nervous system and the affected patients

Patterns of diversity and regeneration in unmanaged moist deciduous forests in response to disturbance in Shiwalik Himalayas, India

Directory of Open Access Journals (Sweden)

Mukesh Kumar Gautam

2016-06-01

Full Text Available We studied vegetation attributes in Indian tropical moist deciduous unmanaged forests to determine the influence of forest disturbances on them. We enumerated 89 species: 72 under moderate disturbance and 54 under least disturbance. The data from 3399 stems [>5 cm diameter at breast height (dbh] decreased linearly along the disturbance gradient. The basal area was largest in least disturbed forests (61 m2/ha and smallest in intensely disturbed forest (41 m2/ha. Under least and moderate disturbance, tree density-diameter distribution had negative exponential curves, whereas highly disturbed forests had unimodal-shaped curves where a few trees 5–10 cm and >50 cm in diameter were recorded. Most tree and shrub layer species under heavy and intense disturbance had impaired regeneration. Moderate disturbance intensity thus apparently benefits species diversity, stand density, and regeneration. Decline in seedlings and saplings, especially tree species, threaten forest regeneration and the maintenance of species diversity of unmanaged tropical forests.

[A novel proposal explaining sleep disturbance of children in Japan--asynchronization].

Science.gov (United States)

Kohyama, Jun

2008-07-01

It has been reported that more than half of the children in Japan suffer from daytime sleepiness. In contrast, about one quarter of junior high-school students in Japan complain of insomnia. According to the International Classification of Sleep Disorders (Second edition), these children could be diagnosed as having behaviorally-induced insufficient sleep syndrome due to inadequate sleeping habits. Getting on adequate amount of sleep should solve such problems;however, such a therapeutic approach often fails. Although social factors are involved in these sleep disturbances, I feel that a novel notion - asynchronization - leads to an understanding of the pathophysiology of disturbances in these children. Further, it could contribute to resolve their problems. The essence of asynchronization is a disturbance of various aspects (e.g., cycle, amplitude, phase, and interrelationship) of the biological rhythms that normally exhibits circadian oscillation. The main cause of asynchronization is hypothesized to be the combination of light exposure during night and the lack of light exposure in the morning. Asynchronization results in the disturbance of variable systems. Thus, symptoms of asynchronization include disturbances of the autonomic nervous system (sleepiness, insomnia, disturbance of hormonal excretion, gastrointestinal problems, etc.) and higher brain function (disorientation, loss of sociality, loss of will or motivation, impaired alertness and performance, etc.). Neurological (attention deficit, aggression, impulsiveness, hyperactivity, etc.), psychiatric (depressive disorders, personality disorders, anxiety disorders, etc.) and somatic (tiredness, fatigue, etc.) disturbances could also be symptoms of asynchronization. At the initial phase of asynchronization, disturbances are functional and can be resolved relatively easily, such as by the establishment of a regular sleep-wakefulness cycle;however, without adequate intervention the disturbances could gradually

Network topology and functional connectivity disturbances precede the onset of Huntington's disease.

Science.gov (United States)

Harrington, Deborah L; Rubinov, Mikail; Durgerian, Sally; Mourany, Lyla; Reece, Christine; Koenig, Katherine; Bullmore, Ed; Long, Jeffrey D; Paulsen, Jane S; Rao, Stephen M

2015-08-01

burden increased. These disturbances were often related to long-range connections involving peripheral nodes and interhemispheric connections. A strong association was found between weaker connectivity and decreased rich-club organization, indicating that whole-brain simple connectivity partially expressed disturbances in the communication of highly-connected hubs. However, network topology and network-based statistic connectivity metrics did not correlate with key markers of executive dysfunction (Stroop Test, Trail Making Test) in prodromal Huntington's disease, which instead were related to whole-brain connectivity disturbances in nodes (right inferior parietal, right thalamus, left anterior cingulate) that exhibited multiple aberrant connections and that mediate executive control. Altogether, our results show for the first time a largely disease burden-dependent functional reorganization of whole-brain networks in prodromal Huntington's disease. Both analytic approaches provided a unique window into brain reorganization that was not related to brain atrophy or motor symptoms. Longitudinal studies currently in progress will chart the course of functional changes to determine the most sensitive markers of disease progression. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hypocretinergic and cholinergic contributions to sleep-wake disturbances in a mouse model of traumatic brain injury

Directory of Open Access Journals (Sweden)

Hannah E. Thomasy

2017-01-01

Full Text Available Disorders of sleep and wakefulness occur in the majority of individuals who have experienced traumatic brain injury (TBI, with increased sleep need and excessive daytime sleepiness often reported. Behavioral and pharmacological therapies have limited efficacy, in part, because the etiology of post-TBI sleep disturbances is not well understood. Severity of injuries resulting from head trauma in humans is highly variable, and as a consequence so are their sequelae. Here, we use a controlled laboratory model to investigate the effects of TBI on sleep-wake behavior and on candidate neurotransmitter systems as potential mediators. We focus on hypocretin and melanin-concentrating hormone (MCH, hypothalamic neuropeptides important for regulating sleep and wakefulness, and two potential downstream effectors of hypocretin actions, histamine and acetylcholine. Adult male C57BL/6 mice (n=6–10/group were implanted with EEG recording electrodes and baseline recordings were obtained. After baseline recordings, controlled cortical impact was used to induce mild or moderate TBI. EEG recordings were obtained from the same animals at 7 and 15 days post-surgery. Separate groups of animals (n=6–8/group were used to determine effects of TBI on the numbers of hypocretin and MCH-producing neurons in the hypothalamus, histaminergic neurons in the tuberomammillary nucleus, and cholinergic neurons in the basal forebrain. At 15 days post-TBI, wakefulness was decreased and NREM sleep was increased during the dark period in moderately injured animals. There were no differences between groups in REM sleep time, nor were there differences between groups in sleep during the light period. TBI effects on hypocretin and cholinergic neurons were such that more severe injury resulted in fewer cells. Numbers of MCH neurons and histaminergic neurons were not altered under the conditions of this study. Thus, we conclude that moderate TBI in mice reduces wakefulness and increases

Disturbance effect of music on processing of verbal and spatial memories.

Science.gov (United States)

Iwanaga, Makoto; Ito, Takako

2002-06-01

The purpose of the present study was to examine the disturbance effect of music on performances of memory tasks. Subjects performed a verbal memory task and a spatial memory task in 4 sound conditions, including the presence of vocal music, instrumental music, a natural sound (murmurings of a stream), and no music. 47 undergraduate volunteers were randomly assigned to perform tasks under each condition. Perceived disturbance was highest under the vocal music condition regardless of the type of task. A disturbance in performance by music was observed only with the verbal memory task under the vocal and the instrumental music conditions. These findings were discussed from the perspectives of the working memory hypothesis and the changing state model.

Disturbance Hydrology: Preparing for an Increasingly Disturbed Future

Science.gov (United States)

Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

2017-12-01

This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre and postdisturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

Classification of Underlying Causes of Power Quality Disturbances: Deterministic versus Statistical Methods

Directory of Open Access Journals (Sweden)

Emmanouil Styvaktakis

2007-01-01

Full Text Available This paper presents the two main types of classification methods for power quality disturbances based on underlying causes: deterministic classification, giving an expert system as an example, and statistical classification, with support vector machines (a novel method as an example. An expert system is suitable when one has limited amount of data and sufficient power system expert knowledge; however, its application requires a set of threshold values. Statistical methods are suitable when large amount of data is available for training. Two important issues to guarantee the effectiveness of a classifier, data segmentation, and feature extraction are discussed. Segmentation of a sequence of data recording is preprocessing to partition the data into segments each representing a duration containing either an event or a transition between two events. Extraction of features is applied to each segment individually. Some useful features and their effectiveness are then discussed. Some experimental results are included for demonstrating the effectiveness of both systems. Finally, conclusions are given together with the discussion of some future research directions.

Cortical Auditory Disorders: A Case of Non-Verbal Disturbances Assessed with Event-Related Brain Potentials

Directory of Open Access Journals (Sweden)

Sönke Johannes

1998-01-01

Full Text Available In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians’ musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19–30 and by event-related potentials (ERP recorded in a modified 'oddball paradigm’. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

Cortical auditory disorders: a case of non-verbal disturbances assessed with event-related brain potentials.

Science.gov (United States)

Johannes, Sönke; Jöbges, Michael E.; Dengler, Reinhard; Münte, Thomas F.

1998-01-01

In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians' musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19-30) and by event-related potentials (ERP) recorded in a modified 'oddball paradigm'. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

Sensory disturbances, inhibitory deficits, and the P50 wave in schizophrenia

Directory of Open Access Journals (Sweden)

Vlcek P

2014-07-01

Full Text Available Premysl Vlcek,1 Petr Bob,1,2 Jiri Raboch1 1Center for Neuropsychiatric Research of Traumatic Stress, Department of Psychiatry and UHSL, First Faculty of Medicine, Charles University, Prague, Czech Republic; 2Central European Institute of Technology (CEITEC, Masaryk University, Brno, Czech Republic Abstract: Sensory gating disturbances in schizophrenia are often described as an inability to filter redundant sensory stimuli that typically manifest as inability to gate neuronal responses related to the P50 wave, characterizing a decreased ability of the brain to inhibit various responses to insignificant stimuli. It implicates various deficits of perceptual and attentional functions, and this inability to inhibit, or “gate”, irrelevant sensory inputs leads to sensory and information overload that also may result in neuronal hyperexcitability related to disturbances of habituation mechanisms. These findings seem to be particularly important in the context of modern electrophysiological and neuroimaging data suggesting that the filtering deficits in schizophrenia are likely related to deficits in the integrity of connections between various brain areas. As a consequence, this brain disintegration produces disconnection of information, disrupted binding, and disintegration of consciousness that in terms of modern neuroscience could connect original Bleuler’s concept of “split mind” with research of neural information integration. Keywords: event-related potential, information overload, inhibition, P50 wave, schizophrenia, splitting

Effect of brain-derived neurotrophic factor on the formation of psycho-vegetative syndrome with brain injury

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Selyanina N.V.

2016-09-01

Full Text Available Aim: to determine the role of brain-derived neurotrophic factor in the formation and forecasting of psycho-vegetative syndrome in patients with cerebral mild to moderate injury. Material and Methods. There have been 150 patients with contusion of the brain, examined. Indicators of neurological, psycho-vegetative status, quantitative content of brain-derived neurotrophic factor (BDNF and nerve growth factor (NGF in the serum were studied. Results. At patients with brain contusion neurological, psycho-vegetative disturbances and decrease neurotrophic factors are determined. It was found to depend of the content of BDNF and psycho-vegetative indicators. Conclusion. The level of brain-derived neurotrophic factor serum (less than 300 pg/ml is a predictor of psycho-vegetative syndrome in the long term of the brain injury.

Neuronal substrates of sensory gating within the human brain.

NARCIS (Netherlands)

Grunwald, T.; Boutros, N.N.; Pezer, N.; Oertzen, J. von; Fernandez, G.S.E.; Schaller, C.; Elger, C.E.

2003-01-01

BACKGROUND: For the human brain, habituation to irrelevant sensory input is an important function whose failure is associated with behavioral disturbances. Sensory gating can be studied by recording the brain's electrical responses to repeated clicks: the P50 potential is normally reduced to the

Interaction between lexical and grammatical language systems in the brain

Science.gov (United States)

Ardila, Alfredo

2012-06-01

This review concentrates on two different language dimensions: lexical/semantic and grammatical. This distinction between a lexical/semantic system and a grammatical system is well known in linguistics, but in cognitive neurosciences it has been obscured by the assumption that there are several forms of language disturbances associated with focal brain damage and hence language includes a diversity of functions (phoneme discrimination, lexical memory, grammar, repetition, language initiation ability, etc.), each one associated with the activity of a specific brain area. The clinical observation of patients with cerebral pathology shows that there are indeed only two different forms of language disturbances (disturbances in the lexical/semantic system and disturbances in the grammatical system); these two language dimensions are supported by different brain areas (temporal and frontal) in the left hemisphere. Furthermore, these two aspects of the language are developed at different ages during child's language acquisition, and they probably appeared at different historical moments during human evolution. Mechanisms of learning are different for both language systems: whereas the lexical/semantic knowledge is based in a declarative memory, grammatical knowledge corresponds to a procedural type of memory. Recognizing these two language dimensions can be crucial in understanding language evolution and human cognition.

Interaction of historical and nonhistorical disturbances maintains native plant communities.

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Davies, K W; Svejcar, T J; Bates, J D

2009-09-01

Historical disturbance regimes are often considered a critical element in maintaining native plant communities. However, the response of plant communities to disturbance may be fundamentally altered as a consequence of invasive plants, climate change, or prior disturbances. The appropriateness of historical disturbance patterns under modern conditions and the interactions among disturbances are issues that ecologists must address to protect and restore native plant communities. We evaluated the response of Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh plant communities to their historical disturbance regime compared to other disturbance regimes. The historical disturbance regime of these plant communities was periodic fires with minimal grazing by large herbivores. We also investigated the influence of prior disturbance (grazing) on the response of these communities to subsequent disturbance (burning). Treatments were: (1) ungrazed (livestock grazing excluded since 1936) and unburned, (2) grazed and unburned, (3) ungrazed and burned (burned in 1993), and (4) grazed and burned. The ungrazed-burned treatment emulated the historical disturbance regime. Vegetation cover, density, and biomass production were measured the 12th, 13th, and 14th year post-burning. Prior to burning the presence of Bromus tectorum L., an exotic annual grass, was minimal (resilience to more severe disturbances. Modern deviations from historical conditions can alter ecosystem response to disturbances, thus restoring the historical disturbance regime may not be an appropriate strategy for all ecosystems.

Optimal Transmission Line Switching under Geomagnetic Disturbances

International Nuclear Information System (INIS)

Lu, Mowen; Nagarajan, Harsha; Yamangil, Emre; Bent, Russell; Backhaus, Scott

2017-01-01

Recently, there have been increasing concerns about how geomagnetic disturbances (GMDs) impact electrical power systems. Geomagnetically-induced currents (GICs) can saturate transformers, induce hot spot heating and increase reactive power losses. These effects can potentially cause catastrophic damage to transformers and severely impact the ability of a power system to deliver power. To address this problem, we develop a model of GIC impacts to power systems that includes 1) GIC thermal capacity of transformers as a function of normal Alternating Current (AC) and 2) reactive power losses as a function of GIC. We also use this model to derive an optimization problem that protects power systems from GIC impacts through line switching, generator dispatch, and load shedding. We then employ state-of-the-art convex relaxations of AC power flow equations to lower bound the objective. We demonstrate the approach on a modified RTS96 system and UIUC 150-bus system and show that line switching is an effective means to mitigate GIC impacts. We also provide a sensitivity analysis of decisions with respect to GMD direction.

Transience after disturbance: Obligate species recovery dynamics depend on disturbance duration.

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Singer, Alexander; Johst, Karin

2017-06-01

After a disturbance event, population recovery becomes an important species response that drives ecosystem dynamics. Yet, it is unclear how interspecific interactions impact species recovery from a disturbance and which role the disturbance duration (pulse or press) plays. Here, we analytically derive conditions that govern the transient recovery dynamics from disturbance of a host and its obligately dependent partner in a two-species metapopulation model. We find that, after disturbance, species recovery dynamics depend on the species' role (i.e. host or obligately dependent species) as well as the duration of disturbance. Host recovery starts immediately after the disturbance. In contrast, for obligate species, recovery depends on disturbance duration. After press disturbance, which allows dynamics to equilibrate during disturbance, obligate species immediately start to recover. Yet, after pulse disturbance, obligate species continue declining although their hosts have already begun to increase. Effectively, obligate species recovery is delayed until a necessary host threshold occupancy is reached. Obligates' delayed recovery arises solely from interspecific interactions independent of dispersal limitations, which contests previous explanations. Delayed recovery exerts a two-fold negative effect, because populations continue declining to even smaller population sizes and the phase of increased risk from demographic stochastic extinction in small populations is prolonged. We argue that delayed recovery and its determinants -species interactions and disturbance duration - have to be considered in biodiversity management. Copyright © 2017 Elsevier Inc. All rights reserved.

The Corpus Callosum Area and Brain Volume in Alzheimer's Disease, Mild Cognitive Impairment and Healthy Controls

International Nuclear Information System (INIS)

Choi, Hee Seok; Kim, Kwang Ki; Yoon, Yup Yoon; Seo, Hyung Suk

2009-01-01

To compare the corpus callosum (CC) area and brain volume among individuals with Alzheimer's disease (AD), mild cognitive impairment (MCI) and healthy controls (HC). To evaluate the relationship of CC area and brain volume in 111 subjects (M:F = 48:63; mean age, 56.9 years) without memory disturbance and 28 subjects (11:17; 66.7years) with memory disturbance. The 11 AD (3:8; 75.7 years), 17 MCI (8:9; 60.9 years) and 28 selected HC (11:17; 66.4 years) patients were investigated for comparison of their CC area and brain volume. A good positive linear correlation was found between CC area and brain volume in subjects without and with memory disturbance (r = 0.64 and 0.66, respectively, p 2 , 715.4 ± 107 cm3) were significantly smaller than in MCI patients (595.9 ± 108, 844.1 ± 85) and the HCs (563.2 ± 75, 818.9 ± 109) (p < 0.05). The CC area and brain volume were not significantly different between MCI patients and the HCs. The CC area was significantly correlated with brain volume. Both CC area and brain volume were significantly smaller in the AD patients

Dynamic responses of a wind turbine drivetrain under turbulent wind and voltage disturbance conditions

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Chengwu Li

2016-05-01

Full Text Available Wind energy is known as one of the most efficient clean renewable energy sources and has attracted extensive research interests in both academic and industry fields. In this study, the effects of turbulent wind and voltage disturbance on a wind turbine drivetrain are analyzed, and a wind turbine drivetrain dynamic model combined with the electric model of a doubly fed induction generator is established. The proposed model is able to account for the dynamic interaction between turbulent wind, voltage disturbance, and mechanical system. Also, the effects of time-varying meshing stiffness, transmission error, and bearing stiffness are included in the mechanical part of the coupled dynamic model. From the resultant model, system modes are computed. In addition, by considering the actual control strategies in the simulation process, the effects of turbulent wind and voltage disturbance on the geared rotor system are analyzed. The computational results show that the turbulent wind and voltage disturbance can cause adverse effects on the wind turbine drivetrain, especially the gearbox. A series of parametric studies are also performed to understand the influences of generator and gearbox parameters on the drivetrain system dynamics. Finally, the appropriate generator parameters having a positive effect on the gearbox in alleviating the extreme loads and the modeling approach for investigating the transient performance of generator are discussed.

Model reduction of nonlinear systems subject to input disturbances

KAUST Repository

Ndoye, Ibrahima

2017-07-10

The method of convex optimization is used as a tool for model reduction of a class of nonlinear systems in the presence of disturbances. It is shown that under some conditions the nonlinear disturbed system can be approximated by a reduced order nonlinear system with similar disturbance-output properties to the original plant. The proposed model reduction strategy preserves the nonlinearity and the input disturbance nature of the model. It guarantees a sufficiently small error between the outputs of the original and the reduced-order systems, and also maintains the properties of input-to-state stability. The matrices of the reduced order system are given in terms of a set of linear matrix inequalities (LMIs). The paper concludes with a demonstration of the proposed approach on model reduction of a nonlinear electronic circuit with additive disturbances.

Lateralization of Egocentric and Allocentric Spatial Processing after Parietal Brain Lesions

Science.gov (United States)

Iachini, Tina; Ruggiero, Gennaro; Conson, Massimiliano; Trojano, Luigi

2009-01-01

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted…

Summary and implications of out-of-pile investigations of local cooling disturbances in LMFBR subassembly geometry under single-phase and boiling conditions

International Nuclear Information System (INIS)

Huber, F.; Peppler, W.

1985-05-01

The consequences of local cooling disturbances in subassemblies of LMFBRs have been investigated out-of-pile at KfK. Flow and temperature distributions in the disturbed region as well as cooling under boiling conditions up to loss of cooling were investigated. Fission gas release was simulated by gas injection. A total of 16 different blockages in 20 test set-ups were used, four of them under sodium and the rest under water conditions. Mainly planar plates of different sizes and arrangements were used as blockages. In some of the experiments performed in water also porous blockages were investigated. The test sections consisted of electrically heated pin bundles with a thermal-hydraulic characteristic corresponding to that of an SNR 300 subassembly. With different parameter settings the single-phase tests in water furnished a multitude of test results on flow and temperature fields and on the behaviour of gas in the recirculation zone. In the experiments involving boiling two boiling patterns were observed: steady-state boiling and oscillating boiling. With increasing boiling intensity the boiling region grew to some extent, but it remained always confined to the blocked zone because of the relatively cold sodium flow around this zone. In the experiments simulating fission gas release it was found that under certain conditions gas accumulates in the reverse flow region behind a blockage and leads to loss of cooling. (orig./GL) [de

Disturbed cortico-amygdalar functional connectivity as pathophysiological correlate of working memory deficits in bipolar affective disorder.

Science.gov (United States)

Stegmayer, Katharina; Usher, Juliana; Trost, Sarah; Henseler, Ilona; Tost, Heike; Rietschel, Marcella; Falkai, Peter; Gruber, Oliver

2015-06-01

Patients suffering from bipolar affective disorder show deficits in working memory functions. In a previous functional magnetic resonance imaging study, we observed an abnormal hyperactivity of the amygdala in bipolar patients during articulatory rehearsal in verbal working memory. In the present study, we investigated the dynamic neurofunctional interactions between the right amygdala and the brain systems that underlie verbal working memory in both bipolar patients and healthy controls. In total, 18 euthymic bipolar patients and 18 healthy controls performed a modified version of the Sternberg item-recognition (working memory) task. We used the psychophysiological interaction approach in order to assess functional connectivity between the right amygdala and the brain regions involved in verbal working memory. In healthy subjects, we found significant negative functional interactions between the right amygdala and multiple cortical brain areas involved in verbal working memory. In comparison with the healthy control subjects, bipolar patients exhibited significantly reduced functional interactions of the right amygdala particularly with the right-hemispheric, i.e., ipsilateral, cortical regions supporting verbal working memory. Together with our previous finding of amygdala hyperactivity in bipolar patients during verbal rehearsal, the present results suggest that a disturbed right-hemispheric "cognitive-emotional" interaction between the amygdala and cortical brain regions underlying working memory may be responsible for amygdala hyperactivation and affects verbal working memory (deficits) in bipolar patients.

Learning after acquired brain injury. Learning the hard way

NARCIS (Netherlands)

Boosman, H.

2015-01-01

Background: When the brain has suffered damage, the learning process can be considerably disturbed. Brain damage can influence what is learned, but also how learning takes place. What patients can learn can be viewed in terms of ‘learning ability’ and how patients learn in terms of ‘learning style’.

Qualitative and quantitative estimations of the effect of geomagnetic field variations on human brain functional state

International Nuclear Information System (INIS)

Belisheva, N.K.; Popov, A.N.; Petukhova, N.V.; Pavlova, L.P.; Osipov, K.S.; Tkachenko, S.Eh.; Baranova, T.I.

1995-01-01

The comparison of functional dynamics of human brain with reference to qualitative and quantitative characteristics of local geomagnetic field (GMF) variations was conducted. Steady and unsteady states of human brain can be determined: by geomagnetic disturbances before the observation period; by structure and doses of GMF variations; by different combinations of qualitative and quantitative characteristics of GMF variations. Decrease of optimal GMF activity level and the appearance of aperiodic disturbances of GMF can be a reason of unsteady brain's state. 18 refs.; 3 figs

Viewing the functional consequences of traumatic brain injury by using brain SPECT.

Science.gov (United States)

Pavel, D; Jobe, T; Devore-Best, S; Davis, G; Epstein, P; Sinha, S; Kohn, R; Craita, I; Liu, P; Chang, Y

2006-03-01

High-resolution brain SPECT is increasingly benefiting from improved image processing software and multiple complementary display capabilities. This enables detailed functional mapping of the disturbances in relative perfusion occurring after TBI. The patient population consisted of 26 cases (ages 8-61 years)between 3 months and 6 years after traumatic brain injury.A very strong case can be made for the routine use of Brain SPECT in TBI. Indeed it can provide a detailed evaluation of multiple functional consequences after TBI and is thus capable of supplementing the clinical evaluation and tailoring the therapeutic strategies needed. In so doing it also provides significant additional information beyond that available from MRI/CT. The critical factor for Brain SPECT's clinical relevance is a carefully designed technical protocol, including displays which should enable a comprehensive description of the patterns found, in a user friendly mode.

Disturbance and distributions: avoiding exclusion in a warming world

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Douglas Sheil

2016-03-01

Full Text Available I highlight how disturbance determines species distributions and the implications for conservation practice. In particular, I describe opportunities to mitigate some of the threats to species resulting from climate change. Ecological theory shows that disturbance processes can often slow or prevent the exclusion of species by competitors and that different disturbance regimes result in different realized niches. There is much evidence of disturbance influencing where species occur. For example, disturbance can lower the high elevation treeline, thus expanding the area for high elevation vegetation that cannot otherwise persist under tree cover. The role of disturbance in influencing interspecific competition and resulting species persistence and distributions appears unjustly neglected. I identify various implications, including opportunities to achieve in situ conservation by expanding plant species ranges and reducing species vulnerability to competitive exclusion. Suitable frequencies, scales, intensities, spatial configurations, and timings of the right forms of disturbance can improve the persistence of targeted species in a wide range of contexts. Such options could reduce the extinctions likely to be associated with climate change. More generally, these mechanisms and the resulting realizable niche also offer novel insights to understanding and manipulating species distributions.

Daytime, low latitude, vertical ExB drift velocities, inferred from ground-based magnetometer observations in the Peruvian, Philippine and Indian longitude sectors under quiet and disturbed conditions

CERN Document Server

Anderson, D; Chau, J; Yumoto, K; Bhattacharya, A; Alex, S

2006-01-01

Daytime, low latitude, vertical ExB drift velocities, inferred from ground-based magnetometer observations in the Peruvian, Philippine and Indian longitude sectors under quiet and disturbed conditions

Clinical use of 'ROTOP-NEUROSPECT' in several brain diseases. Die klinische Anwendung von 'ROTOP-NEUROSPECT' bei verschiedenen hirnorganischen Erkrankungen

Energy Technology Data Exchange (ETDEWEB)

Wuensche, A.; Kaempfer, I.; Loessner, J.; Wagner, A.; Dietrich, J.; Strauss, I.; Neumann, G.; Otto, L.; Koegler, A.; Schenk, S.; Schneider, G. (Leipzig Univ., Klinik fuer Radiologie, Abt. Nuklearmedizin (Germany) Leipzig Univ. (Germany). Klinik fuer Neurologie Leipzig Univ. (Germany). Klinik fuer Neurochirurgie Bezirkskrankenhaus fuer Psychiatrie, Leipzig-Doesen (Germany))

1990-01-01

We proofed the suitibility of ROTOP-NEUROSPECT (R*) (HMPAO) from Rossendorf for consideration of disturbed brain circulation in 42 patients. Results we compared with morphological methods (X-ray computing tomography, angiography) and with clinical and neurological findings. We found often a disturbed brain circulation in emission computing tomography (SPECT) before morphological changes in X-ray computing tomography (CT). ROTOP-NEUROSPECT (R*) from Rossendorf is very well for consideration of disturbed brain circulation, we did not see quality differences between ROTOP-NEUROSPECT and CERETEC from Amersham. Activity accumulations in the liver and gall of both radiopharmaceuticals did not influence the test, because of the big distance to the brain. (orig.).

Reduced astrocyte density underlying brain volume reduction in activity-based anorexia rats

NARCIS (Netherlands)

Frintrop, Linda; Liesbrock, Johanna; Paulukat, Lisa; Johann, Sonja; Kas, Martien J; Tolba, Rene; Heussen, Nicole; Neulen, Joseph; Konrad, Kerstin; Herpertz-Dahlmann, Beate; Beyer, Cordian; Seitz, Jochen

2017-01-01

OBJECTIVES: Severe grey and white matter volume reductions were found in patients with anorexia nervosa (AN) that were linked to neuropsychological deficits while their underlying pathophysiology remains unclear. For the first time, we analysed the cellular basis of brain volume changes in an animal

Brain activation for response inhibition under gaming cue distraction in internet gaming disorder

Directory of Open Access Journals (Sweden)

Gin-Chung Liu

2014-01-01

Full Text Available We evaluated neural substrates related to the loss of control in college students with internet gaming disorder (IGD. We hypothesized that deficit in response inhibition under gaming cue distraction was the possible mechanism for the loss of control internet use. Eleven cases of IGD and 11 controls performed Go/NoGo tasks with/without gaming distraction in the functional magnetic resonance imaging scanner. When the gaming picture was shown as background while individuals were performing Go/NoGo tasks, the IGD group committed more commission errors. The control group increased their brain activations more over the right dorsolateral prefrontal cortex (DLPFC and superior parietal lobe under gaming cue distraction in comparison with the IGD group. Furthermore, brain activation of the right DLPFC and superior parietal lobe were negatively associated with performance of response inhibition among the IGD group. The results suggest that the function of response inhibition was impaired under gaming distraction among the IGD group, and individuals with IGD could not activate right DLPFC and superior parietal lobe to keep cognitive control and attention allocation for response inhibition under gaming cue distraction. This mechanism should be addressed in any intervention for IGD.

Age-related decline in cerebral blood flow and brain atrophy

International Nuclear Information System (INIS)

Takeda, Shumpei; Matsuzawa, Taiju; Yamada, Kenji

1987-01-01

Using computed tomography, the authors studied brain atrophy during aging in 536 men and 529 women with no neurologic disturbances. They measured cerebrospinal fluid (CSF) space volume and cranial cavity volume above the level of the tentorium cerebelli and calculated a brain atrophy index. CFS space volume strated to increase significantly in the group aged from 45 to 54 years, while the BAI started to increase significantly in the group aged from 35 to 44 years in both men and women. The BAI increased exponentially with the increasing age after 25 years, continuing to increase until 75 years or more in both men and women: log BAI = -0.260 + 0.0150 x age, r = 0.707, n = 493, p < 0.001 in men; log BAI = -0.434 + 0.0162 x age, r = 0.757, n = 504, p < 0.001 in women. Using the xenon-133 inhalation method, the authors studied age-related decline in regional cerebral blood flow (regional initial slope index; rISI) in 197 men and 238 women with no neurologic disturbances, ranging in age from 19 to 88 years. The rISI values in women declined almost linearly with the advancing age from the 50s to the 80s except the 70s. The rISI values in men declined with the advancing age from the 40s to the 60s, but remained unchanged thereafter until the 80s, suggesting the existence of a threshold of rISI values. We estimated the rISI values (probable threshold of brain atrophy), the frequency under which is equivalent to the volume of brain tissues atrophying in a decade, and obtained constant values as about 32 for men and about 37 for women in the 50s, 60s and 70s. If the frequency of rISI values in the brain is distributed according to a Gaussian function and mean of rISI values decreases linearly to the increasing age, then brain tissues having rISI values below the thresholds degenerate almost exponentially with the increasing age, leading to the exponential atrophy of the brain. (J.P.N.)

Functional hierarchy underlies preferential connectivity disturbances in schizophrenia.

Science.gov (United States)

Yang, Genevieve J; Murray, John D; Wang, Xiao-Jing; Glahn, David C; Pearlson, Godfrey D; Repovs, Grega; Krystal, John H; Anticevic, Alan

2016-01-12

Schizophrenia may involve an elevated excitation/inhibition (E/I) ratio in cortical microcircuits. It remains unknown how this regulatory disturbance maps onto neuroimaging findings. To address this issue, we implemented E/I perturbations within a neural model of large-scale functional connectivity, which predicted hyperconnectivity following E/I elevation. To test predictions, we examined resting-state functional MRI in 161 schizophrenia patients and 164 healthy subjects. As predicted, patients exhibited elevated functional connectivity that correlated with symptom levels, and was most prominent in association cortices, such as the fronto-parietal control network. This pattern was absent in patients with bipolar disorder (n = 73). To account for the pattern observed in schizophrenia, we integrated neurobiologically plausible, hierarchical differences in association vs. sensory recurrent neuronal dynamics into our model. This in silico architecture revealed preferential vulnerability of association networks to E/I imbalance, which we verified empirically. Reported effects implicate widespread microcircuit E/I imbalance as a parsimonious mechanism for emergent inhomogeneous dysconnectivity in schizophrenia.

Volumetric quantification of brain development using MRI

International Nuclear Information System (INIS)

Iwasaki, N.; Hamano, K.; Okada, Y.; Horigome, Y.; Nakayama, J.; Takeya, T.; Takita, H.; Nose, T.

1997-01-01

We devised a three-dimensional method for estimation of cerebral development and myelination which measures cerebral volume using MRI. Accuracy of the system was estimated using cadaver brains. The mean percentage error in the calculated volumes compared with the real volumes was 2.33 %, range 0.00-5.33 %. We applied the method to the volume of both cerebral hemispheres (CH), basal ganglia, thalamus and internal capsule (BT), and myelinated white matter (WM) in 44 neurologically normal individuals (4 months to 28 years of age), 13 patients with spastic motor disturbances (2-25 years of age), and 9 patients with athetotic motor disturbances (2-23 years of age). In the neurologically normal cases, the volumes of CH, BT and WM increased with age; the volume of MW more slowly than that of CH. In cases with spastic motor disturbances, the volumes of CH, BT and WM were between -1.4 and 3.5 SD, -1.0 and -3.5 SD, and 0.0 and -5.2 SD respectively, of those of neurologically-normal cases. On the other hand, 7 of the 9 cases with athetotic motor disturbances were within 2 SD of the volume of CH in neurologically normal cases. Our method for direct measurement of cerebral volume based on serial MRI should be useful for the accurate assessment of brain development and quantitative analysis of delayed myelination. (orig.)

The Corpus Callosum Area and Brain Volume in Alzheimer's Disease, Mild Cognitive Impairment and Healthy Controls

Energy Technology Data Exchange (ETDEWEB)

Choi, Hee Seok; Kim, Kwang Ki; Yoon, Yup Yoon [Dongguk University Medical Center, Goyang (Korea, Republic of); Seo, Hyung Suk [Korea University Ansan Hospital, Ansan (Korea, Republic of)

2009-07-15

To compare the corpus callosum (CC) area and brain volume among individuals with Alzheimer's disease (AD), mild cognitive impairment (MCI) and healthy controls (HC). To evaluate the relationship of CC area and brain volume in 111 subjects (M:F = 48:63; mean age, 56.9 years) without memory disturbance and 28 subjects (11:17; 66.7years) with memory disturbance. The 11 AD (3:8; 75.7 years), 17 MCI (8:9; 60.9 years) and 28 selected HC (11:17; 66.4 years) patients were investigated for comparison of their CC area and brain volume. A good positive linear correlation was found between CC area and brain volume in subjects without and with memory disturbance (r = 0.64 and 0.66, respectively, p < 0.01). The CC area and brain volume in AD patients (498.7 +- 72 mm{sup 2}, 715.4 +- 107 cm3) were significantly smaller than in MCI patients (595.9 +- 108, 844.1 +- 85) and the HCs (563.2 +- 75, 818.9 +- 109) (p < 0.05). The CC area and brain volume were not significantly different between MCI patients and the HCs. The CC area was significantly correlated with brain volume. Both CC area and brain volume were significantly smaller in the AD patients

Common resting brain dynamics indicate a possible mechanism underlying zolpidem response in severe brain injury

Science.gov (United States)

Williams, Shawniqua T; Conte, Mary M; Goldfine, Andrew M; Noirhomme, Quentin; Gosseries, Olivia; Thonnard, Marie; Beattie, Bradley; Hersh, Jennifer; Katz, Douglas I; Victor, Jonathan D; Laureys, Steven; Schiff, Nicholas D

2013-01-01

Zolpidem produces paradoxical recovery of speech, cognitive and motor functions in select subjects with severe brain injury but underlying mechanisms remain unknown. In three diverse patients with known zolpidem responses we identify a distinctive pattern of EEG dynamics that suggests a mechanistic model. In the absence of zolpidem, all subjects show a strong low frequency oscillatory peak ∼6–10 Hz in the EEG power spectrum most prominent over frontocentral regions and with high coherence (∼0.7–0.8) within and between hemispheres. Zolpidem administration sharply reduces EEG power and coherence at these low frequencies. The ∼6–10 Hz activity is proposed to arise from intrinsic membrane properties of pyramidal neurons that are passively entrained across the cortex by locally-generated spontaneous activity. Activation by zolpidem is proposed to arise from a combination of initial direct drug effects on cortical, striatal, and thalamic populations and further activation of underactive brain regions induced by restoration of cognitively-mediated behaviors. DOI: http://dx.doi.org/10.7554/eLife.01157.001 PMID:24252875

Critical Role of Peripheral Vasoconstriction in Fatal Brain Hyperthermia Induced by MDMA (Ecstasy) under Conditions That Mimic Human Drug Use

Science.gov (United States)

Kim, Albert H.; Wakabayashi, Ken T.; Baumann, Michael H.; Shaham, Yavin

2014-01-01

MDMA (Ecstasy) is an illicit drug used by young adults at hot, crowed “rave” parties, yet the data on potential health hazards of its abuse remain controversial. Here, we examined the effect of MDMA on temperature homeostasis in male rats under standard laboratory conditions and under conditions that simulate drug use in humans. We chronically implanted thermocouple microsensors in the nucleus accumbens (a brain reward area), temporal muscle, and facial skin to measure temperature continuously from freely moving rats. While focusing on brain hyperthermia, temperature monitoring from the two peripheral locations allowed us to evaluate the physiological mechanisms (i.e., intracerebral heat production and heat loss via skin surfaces) that underlie MDMA-induced brain temperature responses. Our data confirm previous reports on high individual variability and relatively weak brain hyperthermic effects of MDMA under standard control conditions (quiet rest, 22−23°C), but demonstrate dramatic enhancements of drug-induced brain hyperthermia during social interaction (exposure to male conspecific) and in warm environments (29°C). Importantly, we identified peripheral vasoconstriction as a critical mechanism underlying the activity- and state-dependent potentiation of MDMA-induced brain hyperthermia. Through this mechanism, which prevents proper heat dissipation to the external environment, MDMA at a moderate nontoxic dose (9 mg/kg or ∼1/5 of LD50 in rats) can cause fatal hyperthermia under environmental conditions commonly encountered by humans. Our results demonstrate that doses of MDMA that are nontoxic under cool, quiet conditions can become highly dangerous under conditions that mimic recreational use of MDMA at rave parties or other hot, crowded venues. PMID:24899699

Volumetric quantification of brain volume in children using sequential CT scans

International Nuclear Information System (INIS)

Hamano, K.; Iwasaki, N.; Kawashima, K.; Takita, H.

1990-01-01

We devised a three dimensional method for the accurate measurement of brain volume and applied it to 32 neurologically normal children, 7 children with only mental retardation and 15 children with both mental retardation and motor disturbance. In the group of neurologically normal children, the total brain volume increased from 723 cm 3 to 1407 cm 3 in order of age. The correlation ratio between the total brain volume and age was significant (P 00600.0001). The values of the total brain volume and the developmental curve were similar to those of the total brain weight of normal children previously reported. The combined volume of the cerebellum, the midbrain, the pons, and the medulla also increased from 76 cm 3 to 200 cm 3 in a manner similar to that of the total brain. The correlation between total brain volume and head circumference was significant (P<0.0001). In the group of children with mental retardation, the total brain volume was relatively smaller than that of neurologically normal children. In the group of the children with mental retardation and motor disturbance, 10 out of 15 cases showed values below -2 SD of those of neurologically normal children. The values of the total brain volume were each less than -3 SD in 3 cases whose head circumferences were each more than -3 SD. Our method for the direct measurement of brain volume based on serial CT scans may be useful for the accurate examination of brain development. (orig.)

Insulin sensitivity : modulation by the brain

NARCIS (Netherlands)

Coomans, Claudia Pascalle

2012-01-01

The studies in this thesis contribute to the understanding of the role of the brain in insulin sensitivity. We demonstrate that disturbances in circadian rhythm resulting in alterations in SCN output, can contribute to the development of insulin resistance. We also shown that insulin-stimulated

Seeking potential contributions to future carbon budget in conterminous US forests considering disturbances

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Zhang, Fangmin; Pan, Yude; Birdsey, Richard A.; Chen, Jing M.; Dugan, Alexa

2017-11-01

Currently, US forests constitute a large carbon sink, comprising about 9 % of the global terrestrial carbon sink. Wildfire is the most significant disturbance influencing carbon dynamics in US forests. Our objective is to estimate impacts of climate change, CO2 concentration, and nitrogen deposition on the future net biome productivity (NBP) of US forests until the end of twenty-first century under a range of disturbance conditions. We designate three forest disturbance scenarios under one future climate scenario to evaluate factor impacts for the future period (2011-2100): (1) no wildfires occur but forests continue to age (Saging), (2) no wildfires occur and forest ages are fixed in 2010 (Sfixed_nodis), and (3) wildfires occur according to a historical pattern, consequently changing forest age (Sdis_age_change). Results indicate that US forests remain a large carbon sink in the late twenty-first century under the Sfixed_nodis scenario; however, they become a carbon source under the Saging and Sdis_age_change scenarios. During the period of 2011 to 2100, climate is projected to have a small direct effect on NBP, while atmospheric CO2 concentration and nitrogen deposition have large positive effects on NBP regardless of the future climate and disturbance scenarios. Meanwhile, responses to past disturbances under the Sfixed_nodis scenario increase NBP regardless of the future climate scenarios. Although disturbance effects on NBP under the Saging and Sdis_age_change scenarios decrease with time, both scenarios experience an increase in NBP prior to the 2050s and then a decrease in NBP until the end of the twenty-first century. This study indicates that there is potential to increase or at least maintain the carbon sink of conterminous US forests at the current level if future wildfires are reduced and age structures are maintained at a productive mix. The effects of CO2 on the future carbon sink may overwhelm effects of other factors at the end of the twenty

Migration of two antibiotics during resuspension under simulated wind-wave disturbances in a water-sediment system.

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Li, Shu; Huang, Zheng; Wang, Yi; Liu, Yu-Qing; Luo, Ran; Shang, Jing-Ge; Liao, Qian-Jia-Hua

2018-02-01

In this study, the migration of antibiotics (norfloxacin, NOR; and sulfamethoxazole, SMX) under simulated resuspension conditions across the sediment-water interface were quantified for two locations in China: point A, located in Meiliang Bay of Lake Taihu, and point B, located in Dapukou of Lake Taihu. The concentrations of suspended solids (SS) in the overlying water amounted to 100, 500, and 1000 mg/L during background, moderate, and strong simulated wind-wave disturbances, respectively. At each SS level, the initial concentrations of the two antibiotics were set to 1, 5, and 10 mg/L. The results showed that both resuspended SS and the initial concentration of antibiotics could influence the migration of NOR in the water-sediment system. Specifically, both higher SS and initial antibiotic concentrations were associated with higher rates of migration and accumulation of NOR from water to sediment. In contrast, the migration of SMX in the water-sediment system was not impacted by SS or initial antibiotic concentration. The adsorption capacities of sediments for NOR and SMX were significantly different at both locations, possibly reflecting differences in cation exchange capacity (CEC) and organic material (OM) contents. In general, higher CEC and OM values were found in sediments with a higher adsorption capacity for the antibiotics. When CEC and OM values of sediments were higher, the adsorption capacity reached up to 51.73 mg/kg. Large differences in the migration from water to sediment were observed for the two antibiotics, with NOR migration rates higher than those of SMX. The accumulation of NOR in surface sediment during resuspension was about 14 times higher than that of SMX. The main reason for this is that the chemical adsorption of NOR is seldom reversible. Overall, this study demonstrates that resuspension of NOR and SMX attached to sediments under simulated wind-wave disturbances can promote the migration of the antibiotics from water to sediment

Scaling disturbance instead of richness to better understand anthropogenic impacts on biodiversity.

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Stephen J Mayor

Full Text Available A primary impediment to understanding how species diversity and anthropogenic disturbance are related is that both diversity and disturbance can depend on the scales at which they are sampled. While the scale dependence of diversity estimation has received substantial attention, the scale dependence of disturbance estimation has been essentially overlooked. Here, we break from conventional examination of the diversity-disturbance relationship by holding the area over which species richness is estimated constant and instead manipulating the area over which human disturbance is measured. In the boreal forest ecoregion of Alberta, Canada, we test the dependence of species richness on disturbance scale, the scale-dependence of the intermediate disturbance hypothesis, and the consistency of these patterns in native versus exotic species and among human disturbance types. We related field observed species richness in 1 ha surveys of 372 boreal vascular plant communities to remotely sensed measures of human disturbance extent at two survey scales: local (1 ha and landscape (18 km2. Supporting the intermediate disturbance hypothesis, species richness-disturbance relationships were quadratic at both local and landscape scales of disturbance measurement. This suggests the shape of richness-disturbance relationships is independent of the scale at which disturbance is assessed, despite that local diversity is influenced by disturbance at different scales by different mechanisms, such as direct removal of individuals (local or indirect alteration of propagule supply (landscape. By contrast, predictions of species richness did depend on scale of disturbance measurement: with high local disturbance richness was double that under high landscape disturbance.

Common and distinct brain networks underlying verbal and visual creativity.

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Zhu, Wenfeng; Chen, Qunlin; Xia, Lingxiang; Beaty, Roger E; Yang, Wenjing; Tian, Fang; Sun, Jiangzhou; Cao, Guikang; Zhang, Qinglin; Chen, Xu; Qiu, Jiang

2017-04-01

Creativity is imperative to the progression of human civilization, prosperity, and well-being. Past creative researches tends to emphasize the default mode network (DMN) or the frontoparietal network (FPN) somewhat exclusively. However, little is known about how these networks interact to contribute to creativity and whether common or distinct brain networks are responsible for visual and verbal creativity. Here, we use functional connectivity analysis of resting-state functional magnetic resonance imaging data to investigate visual and verbal creativity-related regions and networks in 282 healthy subjects. We found that functional connectivity within the bilateral superior parietal cortex of the FPN was negatively associated with visual and verbal creativity. The strength of connectivity between the DMN and FPN was positively related to both creative domains. Visual creativity was negatively correlated with functional connectivity within the precuneus of the pDMN and right middle frontal gyrus of the FPN, and verbal creativity was negatively correlated with functional connectivity within the medial prefrontal cortex of the aDMN. Critically, the FPN mediated the relationship between the aDMN and verbal creativity, and it also mediated the relationship between the pDMN and visual creativity. Taken together, decreased within-network connectivity of the FPN and DMN may allow for flexible between-network coupling in the highly creative brain. These findings provide indirect evidence for the cooperative role of the default and executive control networks in creativity, extending past research by revealing common and distinct brain systems underlying verbal and visual creative cognition. Hum Brain Mapp 38:2094-2111, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Neuroendocrine Disturbances after Brain Damage: An Important and Often Undiagnosed Disorder

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Fatih Tanriverdi

2015-04-01

Full Text Available Traumatic brain injury (TBI is a common and significant public health problem all over the world. Until recently, TBI has been recognized as an uncommon cause of hypopituitarism. The studies conducted during the last 15 years revealed that TBI is a serious cause of hypopituitarism. Although the underlying pathophysiology has not yet been fully clarified, new data indicate that genetic predisposition, autoimmunity and neuroinflammatory changes may play a role in the development of hypopituitarism. Combative sports, including boxing and kickboxing, both of which are characterized by chronic repetitive head trauma, have been shown as new causes of neuroendocrine abnormalities, mainly hypopituitarism, for the first time during the last 10 years. Most patients with TBI-induced pituitary dysfunction remain undiagnosed and untreated because of the non-specific and subtle clinical manifestations of hypopituitarism. Replacement of the deficient hormones, of which GH is the commonest hormone lost, may not only reverse the clinical manifestations and neurocognitive dysfunction, but may also help posttraumatic disabled patients resistant to classical treatment who have undiagnosed hypopituitarism and GH deficiency in particular. Therefore, early diagnosis, which depends on the awareness of TBI as a cause of neuroendocrine abnormalities among the medical community, is crucially important.

Composite control for raymond mill based on model predictive control and disturbance observer

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Dan Niu

2016-03-01

Full Text Available In the raymond mill grinding process, precise control of operating load is vital for the high product quality. However, strong external disturbances, such as variations of ore size and ore hardness, usually cause great performance degradation. It is not easy to control the current of raymond mill constant. Several control strategies have been proposed. However, most of them (such as proportional–integral–derivative and model predictive control reject disturbances just through feedback regulation, which may lead to poor control performance in the presence of strong disturbances. For improving disturbance rejection, a control method based on model predictive control and disturbance observer is put forward in this article. The scheme employs disturbance observer as feedforward compensation and model predictive control controller as feedback regulation. The test results illustrate that compared with model predictive control method, the proposed disturbance observer–model predictive control method can obtain significant superiority in disturbance rejection, such as shorter settling time and smaller peak overshoot under strong disturbances.

Harnessing landscape heterogeneity for managing future disturbance risks in forest ecosystems

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Seidl, Rupert; Albrich, Katharina; Thom, Dominik; Rammer, Werner

2018-01-01

In order to prevent irreversible impacts of climate change on the biosphere it is imperative to phase out the use of fossil fuels. Consequently, the provisioning of renewable resources such as timber and biomass from forests is an ecosystem service of increasing importance. However, risk factors such as changing disturbance regimes are challenging the continuous provisioning of ecosystem services, and are thus a key concern in forest management. We here used simulation modeling to study different risk management strategies in the context of timber production under changing climate and disturbance regimes, focusing on a 8127 ha forest landscape in the Northern Front Range of the Alps in Austria. We show that under a continuation of historical management, disturbances from wind and bark beetles increase by +39.5% on average over 200 years in response to future climate change. Promoting mixed forests and climate-adapted tree species as well as increasing management intensity effectively reduced future disturbance risk. Analyzing the spatial patterns of disturbance on the landscape, we found a highly uneven distribution of risk among stands (Gini coefficients up to 0.466), but also a spatially variable effectiveness of silvicultural risk reduction measures. This spatial variability in the contribution to and control of risk can be used to inform disturbance management: Stands which have a high leverage on overall risk and for which risks can effectively be reduced (24.4% of the stands in our simulations) should be a priority for risk mitigation measures. In contrast, management should embrace natural disturbances for their beneficial effects on biodiversity in areas which neither contribute strongly to landscape-scale risk nor respond positively to risk mitigation measures (16.9% of stands). We here illustrate how spatial heterogeneity in forest landscapes can be harnessed to address both positive and negative effects of changing natural disturbance regimes in

The brain stem function in patients with brain bladder

International Nuclear Information System (INIS)

Takahashi, Toshihiro

1990-01-01

A syndrome of detrusor-sphincter dyssynergia (DSD) is occasionally found in patients with brain bladder. To evaluate the brain stem function in cases of brain bladder, urodynamic study, dynamic CT scan of the brain stem (DCT) and auditory brainstem response (ABR) were performed. The region of interest of DCT aimed at the posterolateral portion of the pons. The results were analysed in contrast with the presense of DSD in urodynamic study. DCT studies were performed in 13 cases with various brain diseases and 5 control cases without neurological diseases. Abnormal patterns of the time-density curve consisted of low peak value, prolongation of filling time and low rapid washout ratio (low clearance ratio) of the contrast medium. Four of 6 cases with DSD showed at least one of the abnormal patterns of the time-density curve bilaterally. In 7 cases without DSD none showed bilateral abnormality of the curve and in 2 of 7 cases only unilateral abnormality was found. ABR was performed in 8 patients with brain diseases. The interpeak latency of the wave I-V (I-V IPL) was considered to be prolonged in 2 cases with DSD compared to that of 4 without DSD. In 2 cases with DSD who had normal DCT findings, measurement of the I-V IPL was impossible due to abnormal pattern of the ABR wave. Above mentioned results suggests the presence of functional disturbance at the posterolateral portion of the pons in cases of brain bladder with DSD. (author)

Monitoring and Assessment of Military Installation Land Condition under Training Disturbance Using Remote Sensing

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Rijal, Santosh

Various military training activities are conducted in more than 11.3 million hectares of land (> 5,500 training sites) in the United States (U.S.). These training activities directly and indirectly degrade the land. Land degradation can impede continuous military training. In order to sustain long term training missions and Army combat readiness, the environmental conditions of the military installations need to be carefully monitored and assessed. Furthermore, the National Environmental Policy Act of 1969 (NEPA) and the U.S. Army Regulation 200-2 require the DoD to minimize the environmental impacts of training and document the environmental consequences of their actions. To achieve these objectives, the Department of Army initiated an Integrated Training Area Management (ITAM) program to manage training lands through assessing their environmental requirements and establishing policies and procedures to achieve optimum, sustainable use of training lands. One of the programs under ITAM, Range and Training Land Assessment (RTLA) was established to collect field-based data for monitoring installation's environmental condition. Due to high cost and inefficiencies involved in the collection of field data, the RTLA program was stopped in several military installations. Therefore, there has been a strong need to develop an efficient and low cost remote sensing based methodology for assessing and monitoring land conditions of military installations. It is also important to make a long-term assessment of installation land condition for understanding cumulative impacts of continuous military training activities. Additionally, it is unclear that compared to non-military land condition, to what extent military training activities have led to the degradation of land condition for military installations. The first paper of this dissertation developed a soil erosion relevant and image derived cover factor (ICF) based on linear spectral mixture (LSM) analysis to assess and

The effect of the diazepam to the free radical under the brain radiation injury

International Nuclear Information System (INIS)

Huo Hongmei; Wang Chen; Zhang Zhilin

2007-01-01

Objective: To study the effect of the diazepam on free radical under in the brain radiation injury in the early stage. Methods: A model of whole brain radiation injury in wakefulness was established in the Sprague-Dawley rat. Diazepam was given intraperitoneally 30 minutes before radiation. The brain tissue homogenate was prepared respectively while the rats were executed 6 hours, 1 day, 1 week, 1 month after irradiation. The contents of the superoxide dismutase (SOD) and the malondialdehyde (MDA) in the tissue homogenate were measured by chemical colorimetry. Results: Diazepam could increase the vigor of SOD and reduce the MDA contents after irradiated. Conclusions: Diazepam has certain neuroprotection effect on radiation injury and decreasing the level of the free radicals. (authors)

On one approach to health protection: Music of the brain.

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Fedotchev, Alexander; Radchenko, Grigoriy; Zemlianaia, Anna

2017-10-18

This review presents the current status of a method for prevention and timely correction of human functional disturbances that was first proposed by Russian neurologist Ya.I. Levin in 1998 and further developed by the authors. The approach is named "Music of the Brain" and is based on musical or music-like stimulation organized in strict accordance with the biopotentials of a patient's brain. Initial studies on the music of the brain approach were analyzed, and its limitations were noted. To enhance the efficiency and usability of the approach, several combinations of music therapy with neurofeedback technique - musical neurofeedback - were developed. Enhanced efficiency of the approach has been shown for correction of functional disturbances during pregnancy and for elimination of stress-induced states in high technology specialists. The use and advantages of musical neurofeedback technology for increasing human cognitive activity, correcting sleep disturbances and treatment of disorders of attention were verified. After further development and testing the approach may be suited for a wide range of therapeutic and rehabilitation procedures in the protection of public health.

Brain atrophy during aging

International Nuclear Information System (INIS)

Matsuzawa, Taiju; Takeda, Shumpei; Hatazawa, Jun

1985-01-01

Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT and following results were obtained. Brain atrophy was minimal in 34 -- 35 years old in both sexes, increased exponentially to the increasing age after 34 -- 35 years, and probably resulted in dementia, such as vascular or multiinfarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34 -- 35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extents of brain atrophy (20 -- 30 %) existed among aged subjects. Some aged subjects had little or no atrophy of their brains, as seen in young subjects, and others had markedly shrunken brains associated with senility. From these results there must be pathological factors promoting brain atrophy with a great individual difference. We have studied the relation of intelligence to brain volume, and have ascertained that progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was decrease in the cerebral blood flow. MNR-CT can easily detected small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy, while X-CT can not. Therefore NMR-CT is very useful for detection of subtle changes in the brain. (J.P.N.)

Hyperactivation in the habenula as a link between depression and sleep disturbance

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Hidenori eAizawa

2013-12-01

Full Text Available Depression occurs frequently with sleep disturbance such as insomnia. Sleep in depression is associated with disinhibition of the rapid eye movement (REM sleep. Despite the coincidence of the depression and sleep disturbance, neural substrate for depressive behaviors and sleep regulation remains unknown.Habenula is an epithalamic structure regulating the activities of monoaminergic neurons in the brain stem. Since the imaging studies showed blood flow increase in the habenula of depressive patients, hyperactivation of the habenula has been implicated in the pathophysiology of the depression. Recent electrophysiological studies reported a novel role of the habenular structure in regulation of REM sleep. In this article, we propose possible cellular mechanisms which could elicit the hyperactivation of the habenular neurons and a hypothesis that dysfunction in the habenular circuit causes the behavioral and sleep disturbance in depression. Analysis of the animals with hyperactivated habenula would open the door to understand roles of the habenula in the heterogeneous symptoms such as reduced motor behavior and altered REM sleep in depression.

CCAAT/Enhancer Binding Protein β in relation to ER Stress, Inflammation, and Metabolic Disturbances

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Sophie E. van der Krieken

2015-01-01

Full Text Available The prevalence of the metabolic syndrome and underlying metabolic disturbances increase rapidly in developed countries. Various molecular targets are currently under investigation to unravel the molecular mechanisms that cause these disturbances. This is done in attempt to counter or prevent the negative health consequences of the metabolic disturbances. Here, we reviewed the current knowledge on the role of C/EBP-β in these metabolic disturbances. C/EBP-β deletion in mice resulted in downregulation of hepatic lipogenic genes and increased expression of β-oxidation genes in brown adipose tissue. Furthermore, C/EBP-β is important in the differentiation and maturation of adipocytes and is increased during ER stress and proinflammatory conditions. So far, studies were only conducted in animals and in cell systems. The results found that C/EBP-β is an important transcription factor within the metabolic disturbances of the metabolic system. Therefore, it is interesting to examine the potential role of C/EBP-β at molecular and physiological level in humans.

Effects of climate change and anthropogenic modification on a disturbance-dependent species in a large riverine system

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Zeigler, Sara; Catlin, Daniel H.; Bomberger Brown, M.; Fraser, J.D.; Dinan, Lauren R.; Hunt, Kelsi L.; Jorgensen, Joel G.; Karpanty, Sarah M.

2017-01-01

Humans have altered nearly every natural disturbance regime on the planet through climate and land-use change, and in many instances, these processes may have interacting effects. For example, projected shifts in temperature and precipitation will likely influence disturbance regimes already affected by anthropogenic fire suppression or river impoundments. Understanding how disturbance-dependent species respond to complex and interacting environmental changes is important for conservation efforts. Using field-based demographic and movement rates, we conducted a metapopulation viability analysis for piping plovers (Charadrius melodus), a threatened disturbance-dependent species, along the Missouri and Platte rivers in the Great Plains of North America. Our aim was to better understand current and projected future metapopulation dynamics given that natural disturbances (flooding or high-flow events) have been greatly reduced by river impoundments and that climate change could further alter the disturbance regime. Although metapopulation abundance has been substantially reduced under the current suppressed disturbance regime (high-flow return interval ~ 20 yr), it could grow if the frequency of high-flow events increases as predicted under likely climate change scenarios. We found that a four-year return interval would maximize metapopulation abundance, and all subpopulations in the metapopulation would act as sources at a return interval of 15 yr or less. Regardless of disturbance frequency, the presence of even a small, stable source subpopulation buffered the metapopulation and sustained a low metapopulation extinction risk. Therefore, climate change could have positive effects in ecosystems where disturbances have been anthropogenically suppressed when climatic shifts move disturbance regimes toward more historical patterns. Furthermore, stable source populations, even if unintentionally maintained through anthropogenic activities, may be critical for the

Ameliorating effects of traditional Chinese medicine preparation, Chinese materia medica and active compounds on ischemia/reperfusion-induced cerebral microcirculatory disturbances and neuron damage

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Sun, Kai; Fan, Jingyu; Han, Jingyan

2015-01-01

Ischemic stroke and ischemia/reperfusion (I/R) injury induced by thrombolytic therapy are conditions with high mortality and serious long-term physical and cognitive disabilities. They have a major impact on global public health. These disorders are associated with multiple insults to the cerebral microcirculation, including reactive oxygen species (ROS) overproduction, leukocyte adhesion and infiltration, brain blood barrier (BBB) disruption, and capillary hypoperfusion, ultimately resulting in tissue edema, hemorrhage, brain injury and delayed neuron damage. Traditional Chinese medicine (TCM) has been used in China, Korea, Japan and other Asian countries for treatment of a wide range of diseases. In China, the usage of compound TCM preparation to treat cerebrovascular diseases dates back to the Han Dynasty. Even thousands of years earlier, the medical formulary recorded many classical prescriptions for treating cerebral I/R-related diseases. This review summarizes current information and underlying mechanisms regarding the ameliorating effects of compound TCM preparation, Chinese materia medica, and active components on I/R-induced cerebral microcirculatory disturbances, brain injury and neuron damage. PMID:26579420

At risk of being risky: The relationship between “brain age” under emotional states and risk preference

OpenAIRE

Marc D. Rudolph; Oscar Miranda-Domínguez; Alexandra O. Cohen; Kaitlyn Breiner; Laurence Steinberg; Richard J. Bonnie; Elizabeth S. Scott; Kim Taylor-Thompson; Jason Chein; Karla C. Fettich; Jennifer A. Richeson; Danielle V. Dellarco; Adriana Galván; B.J. Casey; Damien A. Fair

2017-01-01

Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N = 212; 10–25y) examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the “brain age” of a ...

Research on Francis Turbine Modeling for Large Disturbance Hydropower Station Transient Process Simulation

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Guangtao Zhang

2015-01-01

Full Text Available In the field of hydropower station transient process simulation (HSTPS, characteristic graph-based iterative hydroturbine model (CGIHM has been widely used when large disturbance hydroturbine modeling is involved. However, by this model, iteration should be used to calculate speed and pressure, and slow convergence or no convergence problems may be encountered for some reasons like special characteristic graph profile, inappropriate iterative algorithm, or inappropriate interpolation algorithm, and so forth. Also, other conventional large disturbance hydroturbine models are of some disadvantages and difficult to be used widely in HSTPS. Therefore, to obtain an accurate simulation result, a simple method for hydroturbine modeling is proposed. By this method, both the initial operating point and the transfer coefficients of linear hydroturbine model keep changing during simulation. Hence, it can reflect the nonlinearity of the hydroturbine and be used for Francis turbine simulation under large disturbance condition. To validate the proposed method, both large disturbance and small disturbance simulations of a single hydrounit supplying a resistive, isolated load were conducted. It was shown that the simulation result is consistent with that of field test. Consequently, the proposed method is an attractive option for HSTPS involving Francis turbine modeling under large disturbance condition.

[Brain oedema and acute liver failure].

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Spahr, L

2003-04-01

Brain oedema leading to intracranial hypertension occurs in a significant proportion of patients with acute liver failure in whom it is a leading cause of death. Although precise pathogenic mechanisms associated to this severe complication remain incompletely understood, increasing evidence points to gut-derived neurotoxins including ammonia as key mediators in cerebral osmotic and perfusion disturbances. The management of brain oedema and intracranial hypertension requires a multidisciplinar approach in a center where liver transplantation is available, as this option is the only treatment modality that provides improvement in outcome. This article reviews the most common causes of acute liver failure and the standard of supportive care management, and describes future potential therapeutic aspects of brain oedema and intracranial hypertension.

[Sleep disturbances in children with autistic spectrum disorders].

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Kelmanson, I A

2015-01-01

An association between sleep disorders and autistic spectrum disorders in children is considered. Characteristic variants of sleep disorders, including resistance to going to bed, frequent night awakenings, parasomnias, changes in sleep structure, primarily, the decrease in the percentage of rapid eye movement sleep, are presented. Attention is focused on the possibility of the direct relationship between sleep disturbance and the pathogenesis of autistic spectrum disorders. A role of pathological alterations in the production of neuromediators and morphological changes in the brain structures characteristic of autistic spectrum disorders in the genesis of sleep disorders in children is discussed. Possible non-pharmacological and pharmacological approaches are suggested.

General anesthetics inhibit erythropoietin induction under hypoxic conditions in the mouse brain.

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Tomoharu Tanaka

Full Text Available Erythropoietin (EPO, originally identified as a hematopoietic growth factor produced in the kidney and fetal liver, is also endogenously expressed in the central nervous system (CNS. EPO in the CNS, mainly produced in astrocytes, is induced under hypoxic conditions in a hypoxia-inducible factor (HIF-dependent manner and plays a dominant role in neuroprotection and neurogenesis. We investigated the effect of general anesthetics on EPO expression in the mouse brain and primary cultured astrocytes.BALB/c mice were exposed to 10% oxygen with isoflurane at various concentrations (0.10-1.0%. Expression of EPO mRNA in the brain was studied, and the effects of sevoflurane, halothane, nitrous oxide, pentobarbital, ketamine, and propofol were investigated. In addition, expression of HIF-2α protein was studied by immunoblotting. Hypoxia-induced EPO mRNA expression in the brain was significantly suppressed by isoflurane in a concentration-dependent manner. A similar effect was confirmed for all other general anesthetics. Hypoxia-inducible expression of HIF-2α protein was also significantly suppressed with isoflurane. In the experiments using primary cultured astrocytes, isoflurane, pentobarbital, and ketamine suppressed hypoxia-inducible expression of HIF-2α protein and EPO mRNA.Taken together, our results indicate that general anesthetics suppress activation of HIF-2 and inhibit hypoxia-induced EPO upregulation in the mouse brain through a direct effect on astrocytes.

Altered blood-brain barrier transport in neuro-inflammatory disorders.

Science.gov (United States)

Schenk, Geert J; de Vries, Helga E

2016-06-01

During neurodegenerative and neuroinflammatory disorders of the central nervous system (CNS), such as Alzheimer's disease (AD) and multiple sclerosis (MS), the protective function of the blood-brain barrier (BBB) may be severely impaired. The general neuro-inflammatory response, ranging from activation of glial cells to immune cell infiltration that is frequently associated with such brain diseases may underlie the loss of the integrity and function of the BBB. Consequentially, the delivery and disposition of drugs to the brain will be altered and may influence the treatment efficiency of such diseases. Altered BBB transport of drugs into the CNS during diseases may be the result of changes in both specific transport and non-specific transport pathways. Potential alterations in transport routes like adsorptive mediated endocytosis and receptor-mediated endocytosis may affect drug delivery to the brain. As such, drugs that normally are unable to traverse the BBB may reach their target in the diseased brain due to increased permeability. In contrast, the delivery of (targeted) drugs could be hampered during inflammatory conditions due to disturbed transport mechanisms. Therefore, the inventory of the neuro-inflammatory status of the neurovasculature (or recovery thereof) is of utmost importance in choosing and designing an adequate drug targeting strategy under disease conditions. Within this review we will briefly discuss how the function of the BBB can be affected during disease and how this may influence the delivery of drugs into the diseased CNS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chronic Sleep Disturbance Impairs Glucose Homeostasis in Rats

NARCIS (Netherlands)

Barf, R. Paulien; Meerlo, Peter; Scheurink, Anton J. W.

2010-01-01

Epidemiological studies have shown an association between short or disrupted sleep and an increased risk for metabolic disorders. To assess a possible causal relationship, we examined the effects of experimental sleep disturbance on glucose regulation in Wistar rats under controlled laboratory

Climate-driven disturbances in the San Juan River sub-basin of the Colorado River

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Bennett, Katrina E.; Bohn, Theodore J.; Solander, Kurt; McDowell, Nathan G.; Xu, Chonggang; Vivoni, Enrique; Middleton, Richard S.

2018-01-01

Accelerated climate change and associated forest disturbances in the southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances on the basin scale, and none on the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change on a headwater basin to the Colorado River, the San Juan River watershed, using a robustly calibrated (Nash-Sutcliffe efficiency 0.76) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce evapotranspiration and increase streamflow. In this study, annual average regional streamflow under the coupled climate-disturbance scenarios is at least 6-11 % lower than those scenarios accounting for climate change alone; for forested zones of the San Juan River basin, streamflow is 15-21 % lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbance scenarios indicate a high risk of low water availability for forested headwater systems of the Colorado River basin. These findings also indicate that explicit representation of land cover disturbances is required in modeling efforts that consider the impact of climate change on water resources.

The role of melatonin in radiation induced biochemical disturbances in brain and thyroid gland in adult male albino rats

International Nuclear Information System (INIS)

Abdel Kader, S.M.; EI-Sherbiny, E.M.

2007-01-01

Radiation induced changes in adult male albino male rats before and after melatonin administration were monitored to detect some biochemical changes in brain and thyroid gland. The parameters monitored were dopamine (DA), norepinephdne (NE) and gamma aminobutyric acid (GABA) in brain and triiodothyronine (T 3 ) thyroxine (T 4 ) and thyroid stimulating hormone (TSH) in serum of irradiated adult male albino rats before and after intraperitoneal injection of melatonin. Results indicated that 6.0 Gy whole body γ-irradiated rats showed gradual and significant decrease in DA, NE and GABA contents in different brain areas under investigation (cerebellum, pons+medulla oblongata, corpus striatum, cerebral cortex, hypothalamus, midbrain and hippocampus). The maximum effect of whole body γ-irradiation was observed after 21 days. Moreover, gradual and significant decrease in serum T 3 and T 4 levels were recorded after γ-irradiation. However, TSH level showed significant elevation throughout the experimental period. Melatonin at a dose level of 15 mg/kg b.wt. was intraperitoneally injected daily 30 minutes after 6.0 Gy whole body γ-irradiation, ameliorated DA, NE and GABA contents in different brain areas compared to those measured in irradiated rats. Moreover, melatonin gradually attenuated the effect of γ-irradiation on serum T 3 and T 4 levels to reach nearly the control level at day 21 after melatonin injection. However, melatonin ameliorated the elevated TSH level induced by γ-irradiation to reach its corresponding control value at day 21

Sleep disturbance caused by meaningful sounds and the effect of background noise

Science.gov (United States)

Namba, Seiichiro; Kuwano, Sonoko; Okamoto, Takehisa

2004-10-01

To study noise-induced sleep disturbance, a new procedure called "noise interrupted method"has been developed. The experiment is conducted in the bedroom of the house of each subject. The sounds are reproduced with a mini-disk player which has an automatic reverse function. If the sound is disturbing and subjects cannot sleep, they are allowed to switch off the sound 1 h after they start to try to sleep. This switch off (noise interrupted behavior) is an important index of sleep disturbance. Next morning they fill in a questionnaire in which quality of sleep, disturbance of sounds, the time when they switched off the sound, etc. are asked. The results showed a good relationship between L and the percentages of the subjects who could not sleep in an hour and between L and the disturbance reported in the questionnaire. This suggests that this method is a useful tool to measure the sleep disturbance caused by noise under well-controlled conditions.

Disturbance observer-based L1 robust tracking control for hypersonic vehicles with T-S disturbance modeling

Directory of Open Access Journals (Sweden)

Yang Yi

2016-11-01

Full Text Available This article concerns a disturbance observer-based L1 robust anti-disturbance tracking algorithm for the longitudinal models of hypersonic flight vehicles with different kinds of unknown disturbances. On one hand, by applying T-S fuzzy models to represent those modeled disturbances, a disturbance observer relying on T-S disturbance models can be constructed to track the dynamics of exogenous disturbances. On the other hand, L1 index is introduced to analyze the attenuation performance of disturbance for those unmodeled disturbances. By utilizing the existing convex optimization algorithm, a disturbance observer-based proportional-integral-controlled input is proposed such that the stability of hypersonic flight vehicles can be ensured and the tracking error for velocity and altitude in hypersonic flight vehicle models can converge to equilibrium point. Furthermore, the satisfactory disturbance rejection and attenuation with L1 index can be obtained simultaneously. Simulation results on hypersonic flight vehicle models can reflect the feasibility and effectiveness of the proposed control algorithm.

At risk of being risky: The relationship between "brain age" under emotional states and risk preference.

Science.gov (United States)

Rudolph, Marc D; Miranda-Domínguez, Oscar; Cohen, Alexandra O; Breiner, Kaitlyn; Steinberg, Laurence; Bonnie, Richard J; Scott, Elizabeth S; Taylor-Thompson, Kim; Chein, Jason; Fettich, Karla C; Richeson, Jennifer A; Dellarco, Danielle V; Galván, Adriana; Casey, B J; Fair, Damien A

2017-04-01

Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N=212; 10-25y) examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the "brain age" of a given individual then validate it with an independent measure of cortical thickness. We then show, on average, that "brain age" across the group during the teen years has the propensity to look younger in emotional contexts. Further, we show this phenotype (i.e. a younger brain age in emotional contexts) relates to a group mean difference in risk perception - a pattern exemplified greatest in young-adults (ages 18-21). The results are suggestive of a specified functional brain phenotype that relates to being at "risk to be risky." Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Disturbance Observer based internal Model Controller Design: Applications to Tracking Control of Optical Disk Drive

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyun Taek; Suh, Il Hong [Hanyang University (Korea, Republic of)

1999-02-01

A digital tracking controller is proposed for a precise positioning control under a large repetitive and/or non repetitive disturbances. The proposed controller consists of the internal model controller and the disturbance observer to eliminate the modeling uncertainty. A sufficient condition is given for robust stability of the proposed control system. Numerical Examples are illustrated for a precise head positioning of optical disk drives regardless of a torque disturbance and/or output disturbance. (author). 8 refs., 19 figs.

Neuropsychology of humor: an introduction. Part II. Humor and the brain.

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Derouesné, Christian

2016-09-01

Impairment of the perception or comprehension of humor is observed in patients with focal brain lesions in both hemispheres, but mainly in the right frontal lobe. Studies by functional magnetic resonance imaging in healthy subjects show that humor is associated with activation of two main neural systems in both hemispheres. The detection and resolution of incongruity, cognitive groundings of humor, are associated with activation of the medial prefrontal and temporoparietal cortex, and the humor appreciation with activation of the orbito-frontal and insular cortex, amygdala and the brain reward system. However, activation of these areas is not humor-specific and can be observed in various cognitive or emotional processes. Event-related potential studies confirm the involvement of both hemispheres in humor processing, and suggest that left prefrontal area is associated with joke comprehension and right prefrontal area with the resolution stage. Humor thus appears to be a complex and dynamic functional process involving, on one hand, two specialized but not specific neural systems linked to humor apprehension and appreciation, and, on the other hand, multiple interconnected functional brain networks including neural patterns underlying the moral framework and belief system, acquired by conditioning or imitation during the cognitive development and social interactions of the individual, and more distributed systems associated with the analysis of the current context of humor occurrence. Disturbances of the sense of humor could then result from focal brain alterations localized in one or two of the specialized areas underlying the comprehension or appreciation of humor, or from perturbations of the network interconnectivity in non-focal brain disorders such as Alzheimer's disease or schizophrenia.

Disturbance of visual search by stimulating to posterior parietal cortex in the brain using transcranial magnetic stimulation

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Iramina, Keiji; Ge, Sheng; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo

2009-04-01

In this study, we applied a transcranial magnetic stimulation (TMS) to investigate the temporal aspect for the functional processing of visual attention. Although it has been known that right posterior parietal cortex (PPC) in the brain has a role in certain visual search tasks, there is little knowledge about the temporal aspect of this area. Three visual search tasks that have different difficulties of task execution individually were carried out. These three visual search tasks are the "easy feature task," the "hard feature task," and the "conjunction task." To investigate the temporal aspect of the PPC involved in the visual search, we applied various stimulus onset asynchronies (SOAs) and measured the reaction time of the visual search. The magnetic stimulation was applied on the right PPC or the left PPC by the figure-eight coil. The results show that the reaction times of the hard feature task are longer than those of the easy feature task. When SOA=150 ms, compared with no-TMS condition, there was a significant increase in target-present reaction time when TMS pulses were applied. We considered that the right PPC was involved in the visual search at about SOA=150 ms after visual stimulus presentation. The magnetic stimulation to the right PPC disturbed the processing of the visual search. However, the magnetic stimulation to the left PPC gives no effect on the processing of the visual search.

Effects of naltrexone in postnatal rats on the recovery of disturbed brain and lymphatic tissues after X-irradiation or ethylnitrosourea treatment in utero

International Nuclear Information System (INIS)

Schmahl, W.G.; Plendl, J.; Reinoehl-Kompa, S.

1987-01-01

The role of endogenous opioid systems in preweaning development after intrauterine exposure to X-irradiation or ethylnitrosourea (ENU) was explored in rats using naltrexone, a potent antagonist of beta-endorphin. After daily s.c. injections of 50 mg/kg naltrexone only the prenatally untreated controls had body weights increased by 11% from control level on day 28 (weaning). In the X-irradiated as well as the ENU-treated pups no significant effects of naltrexone on body weight gain were observed. However, brain weight increased in all animals under the influence of naltrexone, irrespective of prenatal treatment or the severity of brain lesions: 9.5% above control values in untreated offspring and 14% after X-irradiation (1 Gy) on gestation day 14. The brain weight of ENU-treated rats (50 mg/kg on gest. day 14) was 13% higher after postnatal naltrexone application than that of their postnatally untreated counterparts. ENU (80 mg/kg) effects on the brain when given on gestation day 18 were ameliorated to 9.2% by naltrexone in the weaning period. Naltrexone significantly increased the thymus weight in controls. Prenatally treated animals also showed an increased thymus weight at weaning, presumably due to compensatory growth. In these cases naltrexone revealed a suppressive effect on the thymus, whereas spleen weight was apparently not influenced by naltrexone treatment. These results provide compelling evidence that endogenous opioid systems play a crucial role not only in normal development, but also in reparative growth events of the brain after prenatal injuries. The thymus, predominantly containing T-lymphocytes, seems to represent another sensitive system which is regulated under the influence of opioids

Effects of naltrexone in postnatal rats on the recovery of disturbed brain and lymphatic tissues after X-irradiation or ethylnitrosourea treatment in utero

Energy Technology Data Exchange (ETDEWEB)

Schmahl, W.G.; Plendl, J.; Reinoehl-Kompa, S.

1987-01-01

The role of endogenous opioid systems in preweaning development after intrauterine exposure to X-irradiation or ethylnitrosourea (ENU) was explored in rats using naltrexone, a potent antagonist of beta-endorphin. After daily s.c. injections of 50 mg/kg naltrexone only the prenatally untreated controls had body weights increased by 11% from control level on day 28 (weaning). In the X-irradiated as well as the ENU-treated pups no significant effects of naltrexone on body weight gain were observed. However, brain weight increased in all animals under the influence of naltrexone, irrespective of prenatal treatment or the severity of brain lesions: 9.5% above control values in untreated offspring and 14% after X-irradiation (1 Gy) on gestation day 14. The brain weight of ENU-treated rats (50 mg/kg on gest. day 14) was 13% higher after postnatal naltrexone application than that of their postnatally untreated counterparts. ENU (80 mg/kg) effects on the brain when given on gestation day 18 were ameliorated to 9.2% by naltrexone in the weaning period. Naltrexone significantly increased the thymus weight in controls. Prenatally treated animals also showed an increased thymus weight at weaning, presumably due to compensatory growth. In these cases naltrexone revealed a suppressive effect on the thymus, whereas spleen weight was apparently not influenced by naltrexone treatment. These results provide compelling evidence that endogenous opioid systems play a crucial role not only in normal development, but also in reparative growth events of the brain after prenatal injuries. The thymus, predominantly containing T-lymphocytes, seems to represent another sensitive system which is regulated under the influence of opioids.

Contribution of seagrass plants to CO2 capture in a tropical seagrass meadow under experimental disturbance.

Science.gov (United States)

Deyanova, Diana; Gullström, Martin; Lyimo, Liberatus D; Dahl, Martin; Hamisi, Mariam I; Mtolera, Matern S P; Björk, Mats

2017-01-01

Coastal vegetative habitats are known to be highly productive environments with a high ability to capture and store carbon. During disturbance this important function could be compromised as plant photosynthetic capacity, biomass, and/or growth are reduced. To evaluate effects of disturbance on CO2 capture in plants we performed a five-month manipulative experiment in a tropical seagrass (Thalassia hemprichii) meadow exposed to two intensity levels of shading and simulated grazing. We assessed CO2 capture potential (as net CO2 fixation) using areal productivity calculated from continuous measurements of diel photosynthetic rates, and estimates of plant morphology, biomass and productivity/respiration (P/R) ratios (from the literature). To better understand the plant capacity to coping with level of disturbance we also measured plant growth and resource allocation. We observed substantial reductions in seagrass areal productivity, biomass, and leaf area that together resulted in a negative daily carbon balance in the two shading treatments as well as in the high-intensity simulated grazing treatment. Additionally, based on the concentrations of soluble carbohydrates and starch in the rhizomes, we found that the main reserve sources for plant growth were reduced in all treatments except for the low-intensity simulated grazing treatment. If permanent, these combined adverse effects will reduce the plants' resilience and capacity to recover after disturbance. This might in turn have long-lasting and devastating effects on important ecosystem functions, including the carbon sequestration capacity of the seagrass system.

Glucose, insulin and the brain: modulation of cognition and synaptic plasticity in health and disease: a preface

NARCIS (Netherlands)

Gispen, W.H.; Biessels, G.J.; Bravenboer, B.

2004-01-01

The brain has long been viewed as an insulin-insensitive organ. Following the demonstration of insulin receptors in the brain, this assumption has been challenged, and a whole new field of research has emerged. Insulin appears to play a role in brain physiology, and disturbances of cerebral insulin

Brain atrophy during aging. Quantitative studies with X-CT and NMR-CT

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Matsuzawa, Taiju; Yamada, Kenji; Yamada, Susumu; Ono, Shuichi; Takeda, Shunpei; Hatazawa, Jun; Ito, Masatoshi; Kubota, Kazuo

1985-12-01

Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT. Brain atrophy was minimal in 34-35 years old in both sexes, increased exponentially to the increasing age after 34-35 years, and probably resulted in dementia, such as vascular or multi-infarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34-35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extent of brain atrophy (20 - 30 %) existed among aged subjects. Progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was the decrease in the cerebral blood flow. We have classified brain atrophy into sulcal and cisternal enlargement type (type I), ventricular enlargement type (type II) and mixed type (type III) according to the clinical study using NMR-CT. Brain atrophy of type I progresses significantly in almost all of the geriatric disorders. This type of brain atrophy progresses significantly in heavy smokers and drinkers. Therefore this type of brain atrophy might be caused by the decline in the blood flow in anterior and middle cerebral arteries. Brain atrophy of type II was caused by the disturbance of cerebrospinal fluid circulation after cerebral bleeding and subarachnoid bleeding. Brain atrophy of type III was seen in vascular dementia or multi-infarct dementia which was caused by loss of brain matter after multiple infarction, and was seen also in dementia of Alzheimer type in which degeneration of nerve cells results in brain atrophy. NMR-CT can easily detect small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy. (J.P.N.).

An investigation on motor-driven power steering-based crosswind disturbance compensation for the reduction of driver steering effort

Science.gov (United States)

Kim, Kyuwon; Kim, Boemjun; Go, Youngil; Park, Jaeyong; Park, Joonhong; Suh, Insoo; Yi, Kyongsu

2014-07-01

This paper describes a lateral disturbance compensation algorithm for an application to a motor-driven power steering (MDPS)-based driver assistant system. The lateral disturbance including wind force and lateral load transfer by bank angle reduces the driver's steering refinement and at the same time increases the possibility of an accident. A lateral disturbance compensation algorithm is designed to determine the motor overlay torque of an MDPS system for reducing the manoeuvreing effort of a human driver under lateral disturbance. Motor overlay torque for the compensation of driver's steering torque induced by the lateral disturbance consists of human torque feedback and feedforward torque. Vehicle-driver system dynamics have been investigated using a combined dynamic model which consists of a vehicle dynamic model, driver steering dynamic model and lateral disturbance model. The human torque feedback input has been designed via the investigation of the vehicle-driver system dynamics. Feedforward input torque is calculated to compensate additional tyre self-aligning torque from an estimated lateral disturbance. The proposed compensation algorithm has been implemented on a developed driver model which represents the driver's manoeuvreing characteristics under the lateral disturbance. The developed driver model has been validated with test data via a driving simulator in a crosswind condition. Human-in-the-loop simulations with a full-scale driving simulator on a virtual test track have been conducted to investigate the real-time performance of the proposed lateral disturbance compensation algorithm. It has been shown from simulation studies and human-in-the-loop simulation results that the driver's manoeuvreing effort and a lateral deviation of the vehicle under the lateral disturbance can be significantly reduced via the lateral disturbance compensation algorithm.

Disturbance, neutral theory, and patterns of beta diversity in soil communities.

Science.gov (United States)

Maaß, Stefanie; Migliorini, Massimo; Rillig, Matthias C; Caruso, Tancredi

2014-12-01

Beta diversity describes how local communities within an area or region differ in species composition/abundance. There have been attempts to use changes in beta diversity as a biotic indicator of disturbance, but lack of theory and methodological caveats have hampered progress. We here propose that the neutral theory of biodiversity plus the definition of beta diversity as the total variance of a community matrix provide a suitable, novel, starting point for ecological applications. Observed levels of beta diversity (BD) can be compared to neutral predictions with three possible outcomes: Observed BD equals neutral prediction or is larger (divergence) or smaller (convergence) than the neutral prediction. Disturbance might lead to either divergence or convergence, depending on type and strength. We here apply these ideas to datasets collected on oribatid mites (a key, very diverse soil taxon) under several regimes of disturbances. When disturbance is expected to increase the heterogeneity of soil spatial properties or the sampling strategy encompassed a range of diverging environmental conditions, we observed diverging assemblages. On the contrary, we observed patterns consistent with neutrality when disturbance could determine homogenization of soil properties in space or the sampling strategy encompassed fairly homogeneous areas. With our method, spatial and temporal changes in beta diversity can be directly and easily monitored to detect significant changes in community dynamics, although the method itself cannot inform on underlying mechanisms. However, human-driven disturbances and the spatial scales at which they operate are usually known. In this case, our approach allows the formulation of testable predictions in terms of expected changes in beta diversity, thereby offering a promising monitoring tool.

Manipulation of colony environment modulates honey bee aggression and brain gene expression.

Science.gov (United States)

Rittschof, C C; Robinson, G E

2013-11-01

The social environment plays an essential role in shaping behavior for most animals. Social effects on behavior are often linked to changes in brain gene expression. In the honey bee (Apis mellifera L.), social modulation of individual aggression allows colonies to adjust the intensity with which they defend their hive in response to predation threat. Previous research has showed social effects on both aggression and aggression-related brain gene expression in honey bees, caused by alarm pheromone and unknown factors related to colony genotype. For example, some bees from less aggressive genetic stock reared in colonies with genetic predispositions toward increased aggression show both increased aggression and more aggressive-like brain gene expression profiles. We tested the hypothesis that exposure to a colony environment influenced by high levels of predation threat results in increased aggression and aggressive-like gene expression patterns in individual bees. We assessed gene expression using four marker genes. Experimentally induced predation threats modified behavior, but the effect was opposite of our predictions: disturbed colonies showed decreased aggression. Disturbed colonies also decreased foraging activity, suggesting that they did not habituate to threats; other explanations for this finding are discussed. Bees in disturbed colonies also showed changes in brain gene expression, some of which paralleled behavioral findings. These results show that bee aggression and associated molecular processes are subject to complex social influences. © 2013 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

A brief introduction of ICRP Publication 49: Developmental effects of irradiation on the brain of the embryo and fetus

International Nuclear Information System (INIS)

Kusama, Tomoko

1988-01-01

ICRP established a task group within its Committee 1 to carry out studies on the effects of irradiation on the central nerve system of embryos and fetuses. The present article summarizes the study results presented in the report, named ICRP Publication 49, published by the task group. Publication 49 consists of seven chapters dealing with the introduction, development of brain and auxiliary organs of embryo primates, retarded development of central nerve system, ionizing radiation as factor in teratogenesis of central nerve system, maximum susceptibility period, risk estimation for human being, and necessity of research. Radiation may cause either organogenetic or histological disturbances depending on the developmental stage of the brain. Results of animal tests can be applied to studies on the morphogenetic disturbances in human beings. Data on embryos and fetuses that received radiation in Hiroshima or Nagasaki are currently used for the estimation of the risk of disturbance in the brain of human embryos and fetuses. Risk estimation for the brain of human embryo exposed to radiation is discussed. (Nogami, K.)

Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment

Directory of Open Access Journals (Sweden)

Sun H

2016-08-01

Full Text Available Hongtao Sun,1,* Maohua Zheng,2,* Yanmin Wang,1 Yunfeng Diao,1 Wanyong Zhao,1 Zhengjun Wei1 1Sixth Department of Neurosurgery, Affiliated Hospital of Logistics University of People’s Armed Police Force, Tianjin, 2Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, People’s Republic of China *These authors contributed equally to this work Objective: The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2 in the course of mild hypothermia treatment (MHT for treating severe traumatic brain injury (sTBI. Methods: There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP, jugular venous oxygen saturation (SjvO2, and cerebral perfusion pressure (CPP were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Results: Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Conclusion: Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome. Keywords: severe traumatic brain injury, hypothermia, brain tissue partial pressure of oxygen, therapy

Functional brain networks underlying detection and integration of disconfirmatory evidence.

Science.gov (United States)

Lavigne, Katie M; Metzak, Paul D; Woodward, Todd S

2015-05-15

.g., 17s after trial onset) the hemodynamic responses associated with all three networks were simultaneously active. These findings highlight distinct cognitive processes and corresponding functional brain networks underlying stages of disconfirmatory evidence integration, and demonstrate the power of multivariate and multi-experiment methodology in cognitive neuroscience. Copyright © 2015 Elsevier Inc. All rights reserved.

[Sex differentiation of central nervous system--brain of man and woman].

Science.gov (United States)

Arai, Yasumasa

2004-02-01

Sex differentiation of human brain is mostly dependent on the prenatal exposure to androgen(testosterone). Congenital aromatase deficiency does not disturb male brain development in men. This is quite different from experimental evidence from rodents whose brains need intraneuronal aromatization from androgen to estrogen to induce sex differentiation. There is evidence for male-female differences in brain structures. Some of them(INHA-3) appear to be related with sexual orientation. The other(BNST) might participate in forming gender-identity. In addition, sexually dimorphic features are recognized in some cognitive activities. The possible involvement of genetic factors in human brain sex differentiation is also discussed.

A Right Brain/Left Brain Model of Acting.

Science.gov (United States)

Bowlen, Clark

Using current right brain/left brain research, this paper develops a model that explains acting's underlying quality--the actor is both himself and the character. Part 1 presents (1) the background of the right brain/left brain theory, (2) studies showing that propositional communication is a left hemisphere function while affective communication…

Different brain activation under left and right ventricular stimulation: an fMRI study in anesthetized rats.

Science.gov (United States)

Suzuki, Hideaki; Sumiyoshi, Akira; Kawashima, Ryuta; Shimokawa, Hiroaki

2013-01-01

Myocardial ischemia in the anterior wall of the left ventricule (LV) and in the inferior wall and/or right ventricle (RV) shows different manifestations that can be explained by the different innervations of cardiac afferent nerves. However, it remains unclear whether information from different areas of the heart, such as the LV and RV, are differently processed in the brain. In this study, we investigated the brain regions that process information from the LV or RV using cardiac electrical stimulation and functional magnetic resonance imaging (fMRI) in anesthetized rats because the combination of these two approaches cannot be used in humans. An electrical stimulation catheter was inserted into the LV or RV (n = 12 each). Brain fMRI scans were recorded during LV or RV stimulation (9 Hz and 0.3 ms width) over 10 blocks consisting of alternating periods of 2 mA for 30 sec followed by 0.2 mA for 60 sec. The validity of fMRI signals was confirmed by first and second-level analyses and temporal profiles. Increases in fMRI signals were observed in the anterior cingulate cortex and the right somatosensory cortex under LV stimulation. In contrast, RV stimulation activated the right somatosensory cortex, which was identified more anteriorly compared with LV stimulation but did not activate the anterior cingulate cortex. This study provides the first evidence for differences in brain activation under LV and RV stimulation. These different brain processes may be associated with different clinical manifestations between anterior wall and inferoposterior wall and/or RV myocardial ischemia.

Brain MRI findings of carbon disulfide poisoning

International Nuclear Information System (INIS)

Cha, Joo Hee; Kim, Mi Jung; Yim, Sang Hyuk; Kim, Sam Soo; Han, Heon; Kim, Rok Ho

2002-01-01

To evaluate the findings of brain MRI in patients with carbon disulfide poisoning. Ninety-one patients who had suffered carbon disulfide poisoning [male:female=87:4; age, 32-74 (mean 53.3) years] were included in this study. To determine the extent of white matter hyperintensity (Grade 0-V) and lacunar infarction, T2-weighted MR imaging of the brain was performed. T2-weighted images depicted white matter hyperintensity in 70 patients (76.9%) and lacunar infarcts in 27 (29.7%). In these patients, the prevalent findings at T2-weighted MR imaging of the brain were white matter hyperintensity and lacunar infarcts. Disturbance of the cardiovascular system by carbon disulfide might account for these results

Brain phenotype of transgenic mice overexpressing cystathionine β-synthase.

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Vinciane Régnier

Full Text Available The cystathionine β-synthase (CBS gene, located on human chromosome 21q22.3, is a good candidate for playing a role in the Down Syndrome (DS cognitive profile: it is overexpressed in the brain of individuals with DS, and it encodes a key enzyme of sulfur-containing amino acid (SAA metabolism, a pathway important for several brain physiological processes.Here, we have studied the neural consequences of CBS overexpression in a transgenic mouse line (60.4P102D1 expressing the human CBS gene under the control of its endogenous regulatory regions. These mice displayed a ∼2-fold increase in total CBS proteins in different brain areas and a ∼1.3-fold increase in CBS activity in the cerebellum and the hippocampus. No major disturbance of SAA metabolism was observed, and the transgenic mice showed normal behavior in the rotarod and passive avoidance tests. However, we found that hippocampal synaptic plasticity is facilitated in the 60.4P102D1 line.We demonstrate that CBS overexpression has functional consequences on hippocampal neuronal networks. These results shed new light on the function of the CBS gene, and raise the interesting possibility that CBS overexpression might have an advantageous effect on some cognitive functions in DS.

Brain phenotype of transgenic mice overexpressing cystathionine β-synthase.

Science.gov (United States)

Régnier, Vinciane; Billard, Jean-Marie; Gupta, Sapna; Potier, Brigitte; Woerner, Stéphanie; Paly, Evelyne; Ledru, Aurélie; David, Sabrina; Luilier, Sabrina; Bizot, Jean-Charles; Vacano, Guido; Kraus, Jan P; Patterson, David; Kruger, Warren D; Delabar, Jean M; London, Jaqueline

2012-01-01

The cystathionine β-synthase (CBS) gene, located on human chromosome 21q22.3, is a good candidate for playing a role in the Down Syndrome (DS) cognitive profile: it is overexpressed in the brain of individuals with DS, and it encodes a key enzyme of sulfur-containing amino acid (SAA) metabolism, a pathway important for several brain physiological processes. Here, we have studied the neural consequences of CBS overexpression in a transgenic mouse line (60.4P102D1) expressing the human CBS gene under the control of its endogenous regulatory regions. These mice displayed a ∼2-fold increase in total CBS proteins in different brain areas and a ∼1.3-fold increase in CBS activity in the cerebellum and the hippocampus. No major disturbance of SAA metabolism was observed, and the transgenic mice showed normal behavior in the rotarod and passive avoidance tests. However, we found that hippocampal synaptic plasticity is facilitated in the 60.4P102D1 line. We demonstrate that CBS overexpression has functional consequences on hippocampal neuronal networks. These results shed new light on the function of the CBS gene, and raise the interesting possibility that CBS overexpression might have an advantageous effect on some cognitive functions in DS.

Disturbance rejection performance analyses of closed loop control systems by reference to disturbance ratio.

Science.gov (United States)

Alagoz, Baris Baykant; Deniz, Furkan Nur; Keles, Cemal; Tan, Nusret

2015-03-01

This study investigates disturbance rejection capacity of closed loop control systems by means of reference to disturbance ratio (RDR). The RDR analysis calculates the ratio of reference signal energy to disturbance signal energy at the system output and provides a quantitative evaluation of disturbance rejection performance of control systems on the bases of communication channel limitations. Essentially, RDR provides a straightforward analytical method for the comparison and improvement of implicit disturbance rejection capacity of closed loop control systems. Theoretical analyses demonstrate us that RDR of the negative feedback closed loop control systems are determined by energy spectral density of controller transfer function. In this manner, authors derived design criteria for specifications of disturbance rejection performances of PID and fractional order PID (FOPID) controller structures. RDR spectra are calculated for investigation of frequency dependence of disturbance rejection capacity and spectral RDR analyses are carried out for PID and FOPID controllers. For the validation of theoretical results, simulation examples are presented. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

A Semiactive and Adaptive Hybrid Control System for a Tracked Vehicle Hydropneumatic Suspension Based on Disturbance Identification

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Shousong Han

2017-01-01

Full Text Available The riding conditions for a high-speed tracked vehicle are quite complex. To enhance the adaptability of suspension systems to different riding conditions, a semiactive and self-adaptive hybrid control strategy based on disturbance velocity and frequency identification was proposed. A mathematical model of the semiactive, self-adaptive hybrid suspension control system, along with a performance evaluation function, was established. Based on a two-degree-of-freedom (DOF suspension system, the kinematic relations and frequency zero-crossing detection method were defined, and expressions for the disturbance velocity and disturbance frequency of the road were obtained. Optimal scheduling of the semiactive hybrid damping control gain (csky, cground, chybrid and self-adaptive control gain (cv under different disturbances were realized by exploiting the particle swarm multiobjective optimization algorithm. An experimental study using a carefully designed test rig was performed under a number of typical riding conditions of tracked vehicles, and the results showed that the proposed control strategy is capable of accurately recognizing different disturbances, shifting between control modes (semiactive/self-adaptive, and scheduling the damping control gain according to the disturbance identification outcomes; hence, the proposed strategy could achieve a good trade-off between ride comfort and ride safety and efficiently increase the overall performance of the suspension under various riding conditions.

The Significance of Brain Transcranial Sonography in Burning Mouth Syndrome: a Pilot Study

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Iris Zavoreo

2017-01-01

Full Text Available Objective: Burning mouth syndrome (BMS is a chronic disorder which is affecting mostly postmenopausal women and is characterized by burning symptoms in the oral cavity on the clinically healthy oral mucosa. The results of previous studies suggested a possible role of peripheral and/or central neurological disturbances in these patients. The aim of this study was to analyze patients with burning mouth syndrome using transcranial sonography. Methods: By use of transcranial sonography of the brain parenchyma, substantia nigra, midbrain raphe and brain nucleus were evaluated in 20 patients with BMS (64.7±12.3 years and 20 controls with chronic pain in the lumbosacral region (61.5±15. Statistical analysis was performed by use of Student t test with significance set at p<0.05. Results: The results of this study have shown hypoechogenicity of the substantia nigra and midbrain raphe as well as hyperechogenicity of the brain nucleus in BMS patients (p<0,05 as compared to controls. Conclusions: Altered transcranial sonography findings of the brain parenchyma, midbrain raphe and brain nucleus in patients with burning mouth syndrome might reflect central disturbances within this syndrome.

Negative Symptoms and Reward Disturbances in Schizophrenia Before and After Antipsychotic Monotherapy

DEFF Research Database (Denmark)

Nielsen, Mette Ødegaard; Rostrup, Egill; Broberg, Brian Villumsen

2018-01-01

BACKGROUND: Negative symptoms (NS) are a central part of the symptomatology of schizophrenia, which is highly correlated to the functional outcome. Disturbances of the brain reward system are suggested to be central in the pathogenesis of NS by decreasing motivation and hedonic experiences...... = .001). DISCUSSION: Patients improving in NS score had a less aberrant reward system at baseline, but reward related activity was reduced over time. Patients not improving in NS showed decreased striatal reward-activity at baseline, which improved over time. Whether this is associated with alteration....... In this study, we compared reward-related brain activity in patients improving and not improving in NS after treatment with amisulpride. METHODS: Thirty-nine antipsychotic-naive patients and 49 healthy controls completed functional magnetic resonance imaging with a modified monetary incentive delay task...

Clinical standard of neurosurgical disorder. (9) Disturbance of consciousness

International Nuclear Information System (INIS)

Ohta, Tomio

2009-01-01

Functional diagnosis of consciousness disturbance (CD) in acute and chronic stages is becoming more important along with the progress of morphological diagnosis by CT and MRI at the stroke and brain lesion. Here described and discussed are the definition of consciousness and unconsciousness, cause and scoring of CD by various scaling and clinical significance of the scale for therapy. The author's definition for consciousness is based on patients' self identity and orientation. The above CD is essentially caused by the increased intracranial pressure, which is evaluable by imaging as the increase is derived from the herniation by tumor or edema mainly through transtentorial (uncal, hippocampal) and/or foraminal (cerebellar tonsillar) pathways. Scaling of CD stands on three factors of validity, reliability and feasibility, of which standards of JCS (Japan coma scale) and GCS (Glasgow coma scale) have been widely employed. In discussion of merit/demerit of JCS and GCS, the author et al. have proposed a new scale ECS (emergency coma scale) with 3 levels of digit code for patient's response and behavior under CD. Therapeutic outcome is greatly affected by acute CD levels evaluable by scaling, in which awakening/alertness relates with mortality, and local symptom/consciousness, with morbidity. ECS is now globally getting around. (K.T.)

The linguistics of schizophrenia: thought disturbance as language pathology across positive symptoms

OpenAIRE

Hinzen, Wolfram; Rossell?, Joana

2015-01-01

We hypothesize that linguistic (dis-)organization in the schizophrenic brain plays a more central role in the pathogenesis of this disease than commonly supposed. Against the standard view, that schizophrenia is a disturbance of thought or selfhood, we argue that the origins of the relevant forms of thought and selfhood at least partially depend on language. The view that they do not is premised by a theoretical conception of language that we here identify as ‘Cartesian’ and contrast with a r...

The linguistics of schizophrenia: thought disturbance as language pathology across positive symptoms

OpenAIRE

Wolfram eHinzen; Wolfram eHinzen; Wolfram eHinzen; Joana eRosselló

2015-01-01

We hypothesize that linguistic (dis-) organization in the schizophrenic brain plays a much more central role in the pathogenesis of this disease than commonly supposed. Against the standard view, that schizophrenia is a disturbance of thought or selfhood, we argue that the origins of the relevant forms of thought and selfhood at least partially depend on language. The view that they do not is premised by a theoretical conception of language that we here identify as ‘Cartesian’ and contrast wi...

Decrease in fMRI brain activation during working memory performed after sleeping under 10 lux light.

Science.gov (United States)

Kang, Seung-Gul; Yoon, Ho-Kyoung; Cho, Chul-Hyun; Kwon, Soonwook; Kang, June; Park, Young-Min; Lee, Eunil; Kim, Leen; Lee, Heon-Jeong

2016-11-09

The aim of this study was to investigate the effect of exposure to dim light at night (dLAN) when sleeping on functional brain activation during a working-memory tasks. We conducted the brain functional magnetic resonance imaging (fMRI) analysis on 20 healthy male subjects. All participants slept in a polysomnography laboratory without light exposure on the first and second nights and under a dim-light condition of either 5 or 10 lux on the third night. The fMRI scanning was conducted during n-back tasks after second and third nights. Statistical parametric maps revealed less activation in the right inferior frontal gyrus (IFG) after exposure to 10-lux light. The brain activity in the right and left IFG areas decreased more during the 2-back task than during the 1- or 0-back task in the 10-lux group. The exposure to 5-lux light had no significant effect on brain activities. The exposure to dLAN might influence the brain function which is related to the cognition.

Detection and classification of power quality disturbances using S-transform and modular neural network

Energy Technology Data Exchange (ETDEWEB)

Bhende, C.N.; Mishra, S.; Panigrahi, B.K. [Department of Electrical Engineering, Indian Institute of Technology, New Delhi 110016 (India)

2008-01-15

This paper presents an S-transform based modular neural network (NN) classifier for recognition of power quality disturbances. The excellent time - frequency resolution characteristics of the S-transform makes it an attractive candidate for the analysis of power quality (PQ) disturbances under noisy condition and has the ability to detect the disturbance correctly. On the other hand, the performance of wavelet transform (WT) degrades while detecting and localizing the disturbances in the presence of noise. Features extracted by using the S-transform are applied to a modular NN for automatic classification of the PQ disturbances that solves a relatively complex problem by decomposing it into simpler subtasks. Modularity of neural network provides better classification, model complexity reduction and better learning capability, etc. Eleven types of PQ disturbances are considered for the classification. The simulation results show that the combination of the S-transform and a modular NN can effectively detect and classify different power quality disturbances. (author)

Torsional Vibration of a Shafting System under Electrical Disturbances

Directory of Open Access Journals (Sweden)

Ling Xiang

2012-01-01

Full Text Available Torsional vibration responses of a nonlinear shafting system are studied by a modified Riccati torsional transfer matrix combining with the Newmark-β method. Firstly, the system is modeled as a chain consisting of an elastic spring with concentrated mass points, from which a multi-segment lumped mass model is established. Secondly, accumulated errors are eliminated from the eigenfrequencies and responses of the system's torsional vibration by this newly developed procedure. The incremental transfer matrix method, combining the modified Riccati torsional transfer matrix with Newmark-β method, is further applied to solve the dynamical equations for the torsional vibration of the nonlinear shafting system. Lastly, the shafting system of a turbine-generator is employed as an illustrating example, and simulation analysis has been performed on the transient responses of the shaft's torsional vibrations during typical power network disturbances, such as three-phase short circuit, two-phase short circuit and asynchronous juxtaposition. The results validate the present method and are instructive for the design of a turbo-generator shaft.

Disturbance recording system

International Nuclear Information System (INIS)

Chandra, A.K.; Deshpande, S.V.; Mayya, A.; Vaidya, U.W.; Premraj, M.K.; Patil, N.B.

1994-01-01

A computerized system for disturbance monitoring, recording and display has been developed for use in nuclear power plants and is versatile enough to be used where ever a large number of parameters need to be recorded, e.g. conventional power plants, chemical industry etc. The Disturbance Recording System (DRS) has been designed to continuously monitor a process plant and record crucial parameters. The DRS provides a centralized facility to monitor and continuously record 64 process parameters scanned every 1 sec for 5 days. The system also provides facility for storage of 64 parameters scanned every 200 msec during 2 minutes prior to and 3 minutes after a disturbance. In addition the system can initiate, on demand, the recording of 8 parameters at a fast rate of every 5 msec for a period of 5 sec. and thus act as a visicorder. All this data is recorded in non-volatile memory and can be displayed, printed/plotted and used for subsequent analysis. Since data can be stored densely on floppy disks, the volume of space required for archival storage is also low. As a disturbance recorder, the DRS allows the operator to view the state of the plant prior to occurrence of the disturbance and helps in identifying the root cause. (author). 10 refs., 7 figs

At risk of being risky: the relationship between “brain age” under emotional states and risk preference

Science.gov (United States)

Rudolph, Marc D.; Miranda-Dominguez, Oscar; Cohen, Alexandra O.; Breiner, Kaitlyn; Steinberg, Laurence; Bonnie, Richard J.; Scott, Elizabeth S.; Taylor-Thompson, Kim A.; Chein, Jason; Fettich, Karla C.; Richeson, Jennifer A.; Dellarco, Danielle V.; Galván, Adriana; Casey, BJ; Fair, Damien A.

2017-01-01

Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N=212; 10–25y) examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the “brain age” of a given individual then validate it with an independent measure of cortical thickness. We then show, on average, that “brain age” across the group during the teen years has the propensity to look younger in emotional contexts. Further, we show this phenotype (i.e. a younger brain age in emotional contexts) relates to a group mean difference in risk perception – a pattern exemplified greatest in young-adults (ages 18–21). The results are suggestive of a specified functional brain phenotype that relates to being at “risk to be risky.” PMID:28279917

At risk of being risky: The relationship between “brain age” under emotional states and risk preference

Directory of Open Access Journals (Sweden)

Marc D. Rudolph

2017-04-01

Full Text Available Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N = 212; 10–25y examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the “brain age” of a given individual then validate it with an independent measure of cortical thickness. We then show, on average, that “brain age” across the group during the teen years has the propensity to look younger in emotional contexts. Further, we show this phenotype (i.e. a younger brain age in emotional contexts relates to a group mean difference in risk perception − a pattern exemplified greatest in young-adults (ages 18–21. The results are suggestive of a specified functional brain phenotype that relates to being at “risk to be risky.”

Possible neuro-Sweet disease mimicking brain tumor in the medulla oblongata--case report.

Science.gov (United States)

Akiba, Chihiro; Esaki, Takanori; Ando, Maya; Furuya, Tsuyoshi; Noda, Kazuyuki; Nakao, Yasuaki; Yamamoto, Takuji; Okuma, Yasuyuki; Mori, Kentaro

2011-01-01

A 62-year-old male presented with a rare case of possible neuro-Sweet Disease (NSD) mimicking brain tumor in the medulla oblongata, manifesting as numbness in the bilateral upper and lower extremities, gait disturbance, dysarthria, and swallowing disturbance which gradually deteriorated over 3 months. Magnetic resonance imaging showed a mass lesion in the medulla oblongata, extending to the upper cervical cord with rim enhancement by gadolinium. The preoperative diagnosis was brain tumor, such as glioma, or inflammatory disease. His neurological symptoms gradually deteriorated, so biopsy was performed through the midline suboccipital approach. Histological examination showed infiltration of inflammatory cells, mainly lymphocytes and macrophages. Human leukocyte antigen typing showed Cw1 and B54 which strongly suggested possible NSD. Steroid pulse therapy was started after surgery and the clinical symptoms improved. Neurosurgeons should be aware of inflammatory disorders such as NSD mimicking brain tumor.

Numerical modelling of the structure of electromagnetic disturbances generated by acoustic-gravity waves

International Nuclear Information System (INIS)

Pogorel'tsev, A.I.; Bidlingmajer, E.R.

1992-01-01

A numeric model of electromagnetic field disturbances generated under the interaction of acoustic-gravitational waves with ionospheric plasma is elaborated and vertical structure of the above disturbances is calculated. The estimates shown that electromagnetic disturbances can penetrate into neutral atmosphere and can be recorded through measurements of the variation of magnetic field and electron field vertical component near the earth is surface. A conclusion is made on a feasibility of monitoring of acoustic-gravitational wave activity in the lower thermosphere through land measurements of magnetic and electric field variations

Glucose metabolism in different regions of the rat brain under hypokinetic stress influence

Science.gov (United States)

Konitzer, K.; Voigt, S.

1980-01-01

Glucose metabolism in rats kept under long term hypokinetic stress was studied in 7 brain regions. Determination was made of the regional levels of glucose, lactate, glutamate, glutamine, aspartate, gamma-aminobutyrate and the incorporation of C-14 from plasma glucose into these metabolites, in glycogen and protein. From the content and activity data the regional glucose flux was approximated quantitatively. Under normal conditions the activity gradient cortex and frontal pole cerebellum, thalamus and mesencephalon, hypothalamus and pons and medulla is identical with that of the regional blood supply (measured with I131 serum albumin as the blood marker). Within the first days of immobilization a functional hypoxia occurred in all brain regions and the utilization of cycle amino acids for protein synthesis was strongly diminished. After the first week of stress the capillary volumes of all regions increased, aerobic glucose metabolism was enhanced (factors 1.3 - 2.0) and the incorporation of glucose C-14 via cycle amino acids into protein was considerably potentiated. The metabolic parameters normalized between the 7th and 11th week of stress. Blood supply and metabolic rate increased most in the hypothalamus.

Defining Disturbance for Microbial Ecology.

Science.gov (United States)

Plante, Craig J

2017-08-01

Disturbance can profoundly modify the structure of natural communities. However, microbial ecologists' concept of "disturbance" has often deviated from conventional practice. Definitions (or implicit usage) have frequently included climate change and other forms of chronic environmental stress, which contradict the macrobiologist's notion of disturbance as a discrete event that removes biomass. Physical constraints and disparate biological characteristics were compared to ask whether disturbances fundamentally differ in microbial and macroorganismal communities. A definition of "disturbance" for microbial ecologists is proposed that distinguishes from "stress" and other competing terms, and that is in accord with definitions accepted by plant and animal ecologists.

Influence of upstream disturbance on the draft-tube flow of Francis turbine under part-load conditions

Science.gov (United States)

Chen, Ting; Zheng, Xianghao; Zhang, Yu-ning; Li, Shengcai

2018-02-01

Owing to the part-load operations for the enhancement of grid flexibility, the Francis turbine often suffers from severe low-frequency and large-amplitude hydraulic instability, which is mostly pertinent to the highly unsteady swirling vortex rope in the draft tube. The influence of disturbances in the upstream (e.g., large-scale vortex structures in the spiral casing) on the draft-tube vortex flow is not well understood yet. In the present paper, the influence of the upstream disturbances on the vortical flow in the draft tube is studied based on the vortex identification method and the analysis of several important parameters (e.g., the swirl number and the velocity profile). For a small guide vane opening (representing the part-load condition), the vortices triggered in the spiral casing propagate downstream and significantly affect the swirling vortex-rope precession in the draft tube, leading to the changes of the intensity and the processional frequency of the swirling vortex rope. When the guide vane opening approaches the optimum one (representing the full-load condition), the upstream disturbance becomes weaker and thus its influences on the downstream flow are very limited.

Model suggests potential for Porites coral population recovery after removal of anthropogenic disturbance (Luhuitou, Hainan, South China Sea).

Science.gov (United States)

Zhao, Meixia; Riegl, Bernhard; Yu, Kefu; Shi, Qi; Zhang, Qiaomin; Liu, Guohui; Yang, Hongqiang; Yan, Hongqiang

2016-09-13

Population models are important for resource management and can inform about potential trajectories useful for planning purposes, even with incomplete monitoring data. From size frequency data on Luhuitou fringing reef, Hainan, South China Sea, a matrix population model of massive corals (Porites lutea) was developed and trajectories over 100 years under no disturbance and random disturbances were projected. The model reflects a largely open population of Porites lutea, with low local recruitment and preponderance of imported recruitment. Under no further disturbance, the population of Porites lutea will grow and its size structure will change from predominance of small size classes to large size classes. Therewith, total Porites cover will increase. Even under random disturbances every 10 to 20 years, the Porites population could remain viable, albeit at lower space cover. The models suggest recovery at Luhuitou following the removal of chronic anthropogenic disturbance. Extending the area of coral reef reserves to protect the open coral community and the path of connectivity is advisable and imperative for the conservation of Hainan's coral reefs.

Model suggests potential for Porites coral population recovery after removal of anthropogenic disturbance (Luhuitou, Hainan, South China Sea)

Science.gov (United States)

Zhao, Meixia; Riegl, Bernhard; Yu, Kefu; Shi, Qi; Zhang, Qiaomin; Liu, Guohui; Yang, Hongqiang; Yan, Hongqiang

2016-09-01

Population models are important for resource management and can inform about potential trajectories useful for planning purposes, even with incomplete monitoring data. From size frequency data on Luhuitou fringing reef, Hainan, South China Sea, a matrix population model of massive corals (Porites lutea) was developed and trajectories over 100 years under no disturbance and random disturbances were projected. The model reflects a largely open population of Porites lutea, with low local recruitment and preponderance of imported recruitment. Under no further disturbance, the population of Porites lutea will grow and its size structure will change from predominance of small size classes to large size classes. Therewith, total Porites cover will increase. Even under random disturbances every 10 to 20 years, the Porites population could remain viable, albeit at lower space cover. The models suggest recovery at Luhuitou following the removal of chronic anthropogenic disturbance. Extending the area of coral reef reserves to protect the open coral community and the path of connectivity is advisable and imperative for the conservation of Hainan’s coral reefs.

A Proposal for the Diagnosis of Emotional Disturbance.

Science.gov (United States)

Eaves, Ronald C.

1982-01-01

The underlying reasons for muddled definitions of emotional disturbance and their resultant befuddled diagnostic processes are discussed in terms of four factors: (1) the impact of theory, (2) societal diversity, (3) benchmarks for decision making, and (4) instrumentation. The author presents a method for diagnosis that is practical, functional,…

Disturbed vesicular trafficking of membrane proteins in prion disease.

Science.gov (United States)

Uchiyama, Keiji; Miyata, Hironori; Sakaguchi, Suehiro

2013-01-01

The pathogenic mechanism of prion diseases remains unknown. We recently reported that prion infection disturbs post-Golgi trafficking of certain types of membrane proteins to the cell surface, resulting in reduced surface expression of membrane proteins and abrogating the signal from the proteins. The surface expression of the membrane proteins was reduced in the brains of mice inoculated with prions, well before abnormal symptoms became evident. Prions or pathogenic prion proteins were mainly detected in endosomal compartments, being particularly abundant in recycling endosomes. Some newly synthesized membrane proteins are delivered to the surface from the Golgi apparatus through recycling endosomes, and some endocytosed membrane proteins are delivered back to the surface through recycling endosomes. These results suggest that prions might cause neuronal dysfunctions and cell loss by disturbing post-Golgi trafficking of membrane proteins via accumulation in recycling endosomes. Interestingly, it was recently shown that delivery of a calcium channel protein to the cell surface was impaired and its function was abrogated in a mouse model of hereditary prion disease. Taken together, these results suggest that impaired delivery of membrane proteins to the cell surface is a common pathogenic event in acquired and hereditary prion diseases.

Intermittent fasting is neuroprotective in focal cerebral ischemia by minimizing autophagic flux disturbance and inhibiting apoptosis.

Science.gov (United States)

Jeong, Ji Heun; Yu, Kwang Sik; Bak, Dong Ho; Lee, Je Hun; Lee, Nam Seob; Jeong, Young Gil; Kim, Dong Kwan; Kim, Jwa-Jin; Han, Seung-Yun

2016-11-01

Previous studies have demonstrated that autophagy induced by caloric restriction (CR) is neuroprotective against cerebral ischemia. However, it has not been determined whether intermittent fasting (IF), a variation of CR, can exert autophagy-related neuroprotection against cerebral ischemia. Therefore, the neuroprotective effect of IF was evaluated over the course of two weeks in a rat model of focal cerebral ischemia, which was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). Specifically, the role of autophagy modulation as a potential underlying mechanism for this phenomenon was investigated. It was demonstrated that IF reduced infarct volume and brain edema, improved neurobehavioral deficits, and rescued neuronal loss after MCAO/R. Furthermore, neuronal apoptosis was decreased by IF in the rat cortex. An increase in the number of autophagosomes (APs) was demonstrated in the cortices of IF-treated rats, using immunofluorescence staining and transmission electron microscopy. Using immunoblots, an IF-induced increase was detected in microtubule-associated protein 1 light chain 3 (LC3)-II, Rab7, and cathepsin D protein levels, which corroborated previous morphological studies. Notably, IF reduced the accumulation of APs and p62, demonstrating that IF attenuated the MCAO/R-induced disturbance of autophagic flux in neurons. The findings of the present study suggest that IF-induced neuroprotection in focal cerebral ischemia is due, at least in part, to the minimization of autophagic flux disturbance and inhibition of apoptosis.

Disturbing, Disordered or Disturbed? Perspectives on the Definition of Problem Behavior in Educational Settings.

Science.gov (United States)

Wood, Frank H., Ed.; Lakin, K. Charlie, Ed.

The book contains five papers presented at a 1979 topical conference on the definition of emotional disturbance and behavioral disorders in educational settings. The first paper, by F. Wood, is titled "Defining Disturbing, Disordered, and Disturbed Behavior." Topics covered include ambivalence about defining deviant behavior by special educators,…

Response diversity can increase ecological resilience to disturbance in coral reefs.

Science.gov (United States)

Baskett, Marissa L; Fabina, Nicholas S; Gross, Kevin

2014-08-01

Community-level resilience depends on the interaction between multiple populations that vary in individual responses to disturbance. For example, in tropical reefs, some corals can survive higher stress (resistance) while others exhibit faster recovery (engineering resilience) following disturbances such as thermal stress. While each type will negatively affect the other through competition, each might also benefit the other by reducing the potential for an additional competitor such as macroalgae to invade after a disturbance. To determine how community composition affects ecological resilience, we modeled coral-macroalgae interactions given either a resistant coral, a resilient coral, or both together. Having both coral types (i.e., response diversity) can lead to observable enhanced ecological resilience if (1) the resilient coral is not a superior competitor and (2) disturbance levels are high enough such that the resilient coral would collapse when considered alone. This enhanced resilience occurs through competitor-enabled rescue where each coral increases the potential for the other to recover from disturbance through external recruitment, such that both corals benefit from the presence of each other in terms of total cover and resilience. Therefore, conservation management aimed at protecting resilience under global change requires consideration of both diversity and connectivity between sites experiencing differential disturbance.

Disturbance Regimes Predictably Alter Diversity in an Ecologically Complex Bacterial System

Directory of Open Access Journals (Sweden)

Sean M. Gibbons

2016-12-01

Full Text Available Diversity is often associated with the functional stability of ecological communities from microbes to macroorganisms. Understanding how diversity responds to environmental perturbations and the consequences of this relationship for ecosystem function are thus central challenges in microbial ecology. Unimodal diversity-disturbance relationships, in which maximum diversity occurs at intermediate levels of disturbance, have been predicted for ecosystems where life history tradeoffs separate organisms along a disturbance gradient. However, empirical support for such peaked relationships in macrosystems is mixed, and few studies have explored these relationships in microbial systems. Here we use complex microbial microcosm communities to systematically determine diversity-disturbance relationships over a range of disturbance regimes. We observed a reproducible switch between community states, which gave rise to transient diversity maxima when community states were forced to mix. Communities showed reduced compositional stability when diversity was highest. To further explore these dynamics, we formulated a simple model that reveals specific regimes under which diversity maxima are stable. Together, our results show how both unimodal and non-unimodal diversity-disturbance relationships can be observed as a system switches between two distinct microbial community states; this process likely occurs across a wide range of spatially and temporally heterogeneous microbial ecosystems.

Metabolic changes in the brain

International Nuclear Information System (INIS)

Meermann, H.

1982-01-01

A positron emission tomograph (PET) is described for displaying the flow pattern of radioactive isotope-labelled substances injected into the human brain. This is claimed to assist in diagnosis of circulation disturbances and to show sugar and oxygen uptake. Emitted gamma rays are detected by rings of 96 detectors whose outputs are used to produce a computer-generated reproduction of the brain, with different colours or densities on a cathode ray tube representing concentration of the labelled substance. Epileptic spasms, Huntington's chorea and drug uptake, as well as albumen content variations due to tumours, are stated to be capable of display. Future uses of the ''PET'' tomograph are discussed. (G.M.E.)

Sleep Disturbances in Neurodevelopmental Disorders.

Science.gov (United States)

Robinson-Shelton, Althea; Malow, Beth A

2016-01-01

Sleep disturbances are extremely prevalent in children with neurodevelopmental disorders compared to typically developing children. The diagnostic criteria for many neurodevelopmental disorders include sleep disturbances. Sleep disturbance in this population is often multifactorial and caused by the interplay of genetic, neurobiological and environmental overlap. These disturbances often present either as insomnia or hypersomnia. Different sleep disorders present with these complaints and based on the clinical history and findings from diagnostic tests, an appropriate diagnosis can be made. This review aims to provide an overview of causes, diagnosis, and treatment of sleep disturbances in neurodevelopmental disorders that present primarily with symptoms of hypersomnia and/or insomnia.

Emotional and personality changes following brain tumour resection.

Science.gov (United States)

Jenkins, Lisanne M; Drummond, Katharine J; Andrewes, David G

2016-07-01

Psychological distress has a high prevalence in brain tumour patients, and understanding the emotional and personality changes that may follow neurosurgery is important for clinical management of these patients. We aimed to characterise these emotional and personality changes using subjective, observer-rated and clinical measures. We examined subjective changes in emotional experience and observer-rated changes to personality disturbances following neurosurgery for brain tumours (n=44), compared to a control group that had undergone spinal surgery (n=26). Participants completed the Hospital Anxiety and Depression Scale and a Subjective Emotional Change Questionnaire. Observers who knew the patients well also completed the Iowa Rating Scale of Personality Change. Compared to controls, patients with tumours reported significantly more changes to their subjective experience of emotions following neurosurgery, particularly anger, disgust and sadness. For the observer-ratings, tumour patients were described as having significant changes in the personality disturbances of irritability, impulsivity, moodiness, inflexibility, and being easily overwhelmed. Anxiety and depression were not significantly different between groups. Neurosurgical resection of a brain tumour is a major life event that changes patients' subjective experiences of different emotions, and leads to observer-rated changes in personality. In this study, these changes were not accompanied by increases in anxiety or depression. We conclude with a discussion of biological and psychosocial mechanisms that can impact emotional functioning and personality in patients with brain tumours. Copyright © 2015 Elsevier Ltd. All rights reserved.

PET scan perfusion imaging in the Prader-Willi syndrome: new insights into the psychiatric and social disturbances

International Nuclear Information System (INIS)

Mantoulan, C.; Payoux, P.; Mantoulan, C.; Diene, G.; Glattard, M.; Molinas, C.; Tauber, M.; Payoux, P.; Sevely, A.; Glattard, M.; Roge, B.; Molinas, C.; Tauber, M.; Zilbovicius, M.; Celsis, P.; Celsis, P.

2011-01-01

The Prader-Willi syndrome (PWS), a rare multisystem genetic disease, leads to severe disabilities, such as morbid obesity, endocrine dysfunctions, psychiatric disorders, and social disturbances. We explored the whole brain of patients with PWS to detect abnormalities that might explain the behavioral and social disturbances, as well as the psychiatric disorders of these patients. Nine patients with PWS (six males, three females; mean age 16.4 years) underwent a positron emission tomography (PET) scan with H(2)(15)O as a tracer to measure regional cerebral blood flow (rCBF). The images were compared with those acquired from nine controls (six males, three females; mean age 21.2 years). A morphologic magnetic resonance imaging (MRI) was also performed in PWS patients, and their cognitive and behavioral skills were assessed with Wechsler Intelligence Scale for Children III and the Child Behavior Check List (CBCL). The MRI images showed no evident anatomic abnormalities, whereas PET scans revealed hypo-perfused brain regions in PWS patients compared with controls, particularly in the anterior cingulum and superior temporal regions. We observed a significant relationship (P≤0.05) between rCBF in the hypo-perfused regions and CBCL scores. The functional consequences of these perfusion abnormalities in specific brain regions might explain the behavioral and social problems observed in these individuals. (authors)

A Delta Operator Approach for the Discrete-Time Active Disturbance Rejection Control on Induction Motors

Directory of Open Access Journals (Sweden)

John Cortés-Romero

2013-01-01

Full Text Available The problem of active disturbance rejection control of induction motors is tackled by means of a generalized PI observer based discrete-time control, using the delta operator approach as the methodology of analyzing the sampled time process. In this scheme, model uncertainties and external disturbances are included in a general additive disturbance input which is to be online estimated and subsequently rejected via the controller actions. The observer carries out the disturbance estimation, thus reducing the complexity of the controller design. The controller efficiency is tested via some experimental results, performing a trajectory tracking task under load variations.

Disturbance attenuation for uncertain control systems with contributions by Alberto Isidori and Dietrich Flockerzi

CERN Document Server

Knobloch, Hans Wilhelm

2014-01-01

  This book presents a survey on recent attempts to treat classical regulator design problems in case of an uncertain dynamics. It is shown that source of the uncertainty can be twofold: (i) The system is under the influence of an exogenous disturbance about which one has only incomplete - or none - information. (ii) A portion of the dynamical law is unspecified - due to imperfect modeling. Both cases are described by the state space model in a unified way “Disturbance Attenuation for Uncertain Control Systems” presents a variety of approaches to the design problem in the presence of a (partly) unknown disturbance signal. There is a clear philosophy underlying each approach which can be characterized by either one of the following terms: Adaptive Control, Worst Case Design, Dissipation Inequalities.  .

Developmental trajectories of brain maturation and behavior: Relevance to major mental illnesses.

Science.gov (United States)

Lockhart, Sedona; Sawa, Akira; Niwa, Minae

2018-05-01

Adverse events in childhood and adolescence, such as social neglect or drug abuse, are known to lead to behavioral changes in young adulthood. This is particularly true for the subset of people who are intrinsically more vulnerable to stressful conditions. Yet the underlying mechanisms for such developmental trajectory from early life insult to aberrant adult behavior remains elusive. Adolescence is a period of dynamic physiological, psychological, and behavioral changes, encompassing a distinct neurodevelopmental stage called the 'critical period'. During adolescence, the brain is uniquely susceptible to stress. Stress mediators may lead to disturbances to biological processes that can cause permanent alterations in the adult stage, even as severe as the onset of mental illness when paired with genetic risk and environmental factors. Understanding the molecular factors governing the critical period and how stress can disturb the maturation processes will allow for better treatment and prevention of late adolescent/young adult onset psychiatric disorders. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Cross Talk Between Brain Innate Immunity and Serotonin Signaling Underlies Depressive-Like Behavior Induced by Alzheimer's Amyloid-β Oligomers in Mice.

Science.gov (United States)

Ledo, Jose Henrique; Azevedo, Estefania P; Beckman, Danielle; Ribeiro, Felipe C; Santos, Luis E; Razolli, Daniela S; Kincheski, Grasielle C; Melo, Helen M; Bellio, Maria; Teixeira, Antonio L; Velloso, Licio A; Foguel, Debora; De Felice, Fernanda G; Ferreira, Sergio T

2016-11-30

Considerable clinical and epidemiological evidence links Alzheimer's disease (AD) and depression. However, the molecular mechanisms underlying this connection are largely unknown. We reported recently that soluble Aβ oligomers (AβOs), toxins that accumulate in AD brains and are thought to instigate synapse damage and memory loss, induce depressive-like behavior in mice. Here, we report that the mechanism underlying this action involves AβO-induced microglial activation, aberrant TNF-α signaling, and decreased brain serotonin levels. Inactivation or ablation of microglia blocked the increase in brain TNF-α and abolished depressive-like behavior induced by AβOs. Significantly, we identified serotonin as a negative regulator of microglial activation. Finally, AβOs failed to induce depressive-like behavior in Toll-like receptor 4-deficient mice and in mice harboring a nonfunctional TLR4 variant in myeloid cells. Results establish that AβOs trigger depressive-like behavior via a double impact on brain serotonin levels and microglial activation, unveiling a cross talk between brain innate immunity and serotonergic signaling as a key player in mood alterations in AD. Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the main cause of dementia in the world. Brain accumulation of amyloid-β oligomers (AβOs) is a major feature in the pathogenesis of AD. Although clinical and epidemiological data suggest a strong connection between AD and depression, the underlying mechanisms linking these two disorders remain largely unknown. Here, we report that aberrant activation of the brain innate immunity and decreased serotonergic tonus in the brain are key players in AβO-induced depressive-like behavior in mice. Our findings may open up new possibilities for the development of effective therapeutics for AD and depression aimed at modulating microglial function. Copyright © 2016 the authors 0270-6474/16/3612106-11$15.00/0.

Brain mechanisms underlying human communication

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Matthijs L Noordzij

2009-07-01

Full Text Available Human communication has been described as involving the coding-decoding of a conventional symbol system, which could be supported by parts of the human motor system (i.e. the “mirror neurons system”. However, this view does not explain how these conventions could develop in the first place. Here we target the neglected but crucial issue of how people organize their non-verbal behavior to communicate a given intention without pre-established conventions. We have measured behavioral and brain responses in pairs of subjects during communicative exchanges occurring in a real, interactive, on-line social context. In two fMRI studies, we found robust evidence that planning new communicative actions (by a sender and recognizing the communicative intention of the same actions (by a receiver relied on spatially overlapping portions of their brains (the right posterior superior temporal sulcus. The response of this region was lateralized to the right hemisphere, modulated by the ambiguity in meaning of the communicative acts, but not by their sensorimotor complexity. These results indicate that the sender of a communicative signal uses his own intention recognition system to make a prediction of the intention recognition performed by the receiver. This finding supports the notion that our communicative abilities are distinct from both sensorimotor processes and language abilities.

Brain mechanisms underlying human communication.

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Noordzij, Matthijs L; Newman-Norlund, Sarah E; de Ruiter, Jan Peter; Hagoort, Peter; Levinson, Stephen C; Toni, Ivan

2009-01-01

Human communication has been described as involving the coding-decoding of a conventional symbol system, which could be supported by parts of the human motor system (i.e. the "mirror neurons system"). However, this view does not explain how these conventions could develop in the first place. Here we target the neglected but crucial issue of how people organize their non-verbal behavior to communicate a given intention without pre-established conventions. We have measured behavioral and brain responses in pairs of subjects during communicative exchanges occurring in a real, interactive, on-line social context. In two fMRI studies, we found robust evidence that planning new communicative actions (by a sender) and recognizing the communicative intention of the same actions (by a receiver) relied on spatially overlapping portions of their brains (the right posterior superior temporal sulcus). The response of this region was lateralized to the right hemisphere, modulated by the ambiguity in meaning of the communicative acts, but not by their sensorimotor complexity. These results indicate that the sender of a communicative signal uses his own intention recognition system to make a prediction of the intention recognition performed by the receiver. This finding supports the notion that our communicative abilities are distinct from both sensorimotor processes and language abilities.

A game theoretic approach to a finite-time disturbance attenuation problem

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Rhee, Ihnseok; Speyer, Jason L.

1991-01-01

A disturbance attenuation problem over a finite-time interval is considered by a game theoretic approach where the control, restricted to a function of the measurement history, plays against adversaries composed of the process and measurement disturbances, and the initial state. A zero-sum game, formulated as a quadratic cost criterion subject to linear time-varying dynamics and measurements, is solved by a calculus of variation technique. By first maximizing the quadratic cost criterion with respect to the process disturbance and initial state, a full information game between the control and the measurement residual subject to the estimator dynamics results. The resulting solution produces an n-dimensional compensator which expresses the controller as a linear combination of the measurement history. A disturbance attenuation problem is solved based on the results of the game problem. For time-invariant systems it is shown that under certain conditions the time-varying controller becomes time-invariant on the infinite-time interval. The resulting controller satisfies an H(infinity) norm bound.

Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach.

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Jiménez, José Víctor; Carrillo-Pérez, Diego Luis; Rosado-Canto, Rodrigo; García-Juárez, Ignacio; Torre, Aldo; Kershenobich, David; Carrillo-Maravilla, Eduardo

2017-08-01

Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

Disturbance by optimal discrimination

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Kawakubo, Ryûitirô; Koike, Tatsuhiko

2018-03-01

We discuss the disturbance by measurements which unambiguously discriminate between given candidate states. We prove that such an optimal measurement necessarily changes distinguishable states indistinguishable when the inconclusive outcome is obtained. The result was previously shown by Chefles [Phys. Lett. A 239, 339 (1998), 10.1016/S0375-9601(98)00064-4] under restrictions on the class of quantum measurements and on the definition of optimality. Our theorems remove these restrictions and are also applicable to infinitely many candidate states. Combining with our previous results, one can obtain concrete mathematical conditions for the resulting states. The method may have a wide variety of applications in contexts other than state discrimination.

Receptivity of Boundary Layer over a Blunt Wedge due to Freestream Pulse Disturbances at Mach 6

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Jianqiang Shi

2016-01-01

Full Text Available Direct numerical simulation (DNS of a hypersonic compressible flow over a blunt wedge with fast acoustic disturbances in freestream is performed. The receptivity characteristics of boundary layer to freestream pulse acoustic disturbances are numerically investigated at Mach 6, and the frequency effects of freestream pulse wave on boundary layer receptivity are discussed. Results show that there are several main disturbance mode clusters in boundary layer under acoustic pulse wave, and the number of main disturbance clusters decreases along the streamwise. As disturbance wave propagates from upstream to downstream direction, the component of the modes below fundamental frequency decreases, and the component of the modes above second harmonic components increases quickly in general. There are competition and disturbance energy transfer between different boundary layer modes. The nose boundary layer is dominated by the nearby mode of fundamental frequency. The number of the main disturbance mode clusters decreases as the freestream disturbance frequency increases. The frequency range with larger growth narrows along the streamwise. In general, the amplitudes of both fundamental mode and harmonics become larger with the decreasing of freestream disturbance frequency. High frequency freestream disturbance accelerates the decay of disturbance wave in downstream boundary layer.

Colorado River basin sensitivity to disturbance impacts

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Bennett, K. E.; Urrego-Blanco, J. R.; Jonko, A. K.; Vano, J. A.; Newman, A. J.; Bohn, T. J.; Middleton, R. S.

2017-12-01

The Colorado River basin is an important river for the food-energy-water nexus in the United States and is projected to change under future scenarios of increased CO2emissions and warming. Streamflow estimates to consider climate impacts occurring as a result of this warming are often provided using modeling tools which rely on uncertain inputs—to fully understand impacts on streamflow sensitivity analysis can help determine how models respond under changing disturbances such as climate and vegetation. In this study, we conduct a global sensitivity analysis with a space-filling Latin Hypercube sampling of the model parameter space and statistical emulation of the Variable Infiltration Capacity (VIC) hydrologic model to relate changes in runoff, evapotranspiration, snow water equivalent and soil moisture to model parameters in VIC. Additionally, we examine sensitivities of basin-wide model simulations using an approach that incorporates changes in temperature, precipitation and vegetation to consider impact responses for snow-dominated headwater catchments, low elevation arid basins, and for the upper and lower river basins. We find that for the Colorado River basin, snow-dominated regions are more sensitive to uncertainties. New parameter sensitivities identified include runoff/evapotranspiration sensitivity to albedo, while changes in snow water equivalent are sensitive to canopy fraction and Leaf Area Index (LAI). Basin-wide streamflow sensitivities to precipitation, temperature and vegetation are variable seasonally and also between sub-basins; with the largest sensitivities for smaller, snow-driven headwater systems where forests are dense. For a major headwater basin, a 1ºC of warming equaled a 30% loss of forest cover, while a 10% precipitation loss equaled a 90% forest cover decline. Scenarios utilizing multiple disturbances led to unexpected results where changes could either magnify or diminish extremes, such as low and peak flows and streamflow timing

miR-98 and let-7g* protect the blood-brain barrier under neuroinflammatory conditions.

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Rom, Slava; Dykstra, Holly; Zuluaga-Ramirez, Viviana; Reichenbach, Nancy L; Persidsky, Yuri

2015-12-01

Pathologic conditions in the central nervous system, regardless of the underlying injury mechanism, show a certain level of blood-brain barrier (BBB) impairment. Endothelial dysfunction is the earliest event in the initiation of vascular damage caused by inflammation due to stroke, atherosclerosis, trauma, or brain infections. Recently, microRNAs (miRNAs) have emerged as a class of gene expression regulators. The relationship between neuroinflammation and miRNA expression in brain endothelium remains unexplored. Previously, we showed the BBB-protective and anti-inflammatory effects of glycogen synthase kinase (GSK) 3β inhibition in brain endothelium in in vitro and in vivo models of neuroinflammation. Using microarray screening, we identified miRNAs induced in primary human brain microvascular endothelial cells after exposure to the pro-inflammatory cytokine, tumor necrosis factor-α, with/out GSK3β inhibition. Among the highly modified miRNAs, let-7 and miR-98 were predicted to target the inflammatory molecules, CCL2 and CCL5. Overexpression of let-7 and miR-98 in vitro and in vivo resulted in reduced leukocyte adhesion to and migration across endothelium, diminished expression of pro-inflammatory cytokines, and increased BBB tightness, attenuating barrier 'leakiness' in neuroinflammation conditions. For the first time, we showed that miRNAs could be used as a therapeutic tool to prevent the BBB dysfunction in neuroinflammation.

Intertidal soft-sediment community does not respond to disturbance as postulated by the intermediate disturbance hypothesis

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Gerwing, Travis G.; Allen Gerwing, Alyssa M.; Macdonald, Tara; Cox, Kieran; Juanes, Francis; Dudas, Sarah E.

2017-11-01

The Intermediate Disturbance Hypothesis (IDH) predicts that disturbances of an intermediate frequency or intensity will maximize community biodiversity/richness. Once almost universally accepted, controversy now surrounds this hypothesis, and there have even been calls for its abandonment. Therefore, we experimentally evaluated if an infaunal community along the north coast of British Columbia, Canada, would respond to disturbances as predicted by the IDH. The characteristics of this soft-sediment intertidal mudflat (productivity, species pool, population growth rate) maximized our chances of finding evidence to support the IDH. More specifically, we tested if intermediate severities and frequencies of disturbance maximized infaunal community richness by mechanically disturbing sediment, and varying the intensity (0%, 25%, 50%, 75%, and 100% of the surface area of a plot disturbed) and frequency of sediment disturbance (never, once, twice, and every week during a four week period). No effect of frequency or intensity of sediment disturbance on community richness was observed. Further, none of our experimental treatments were statistically different than the controls. This is likely due to the subtle difference between successional stages in this soft-sediment habitat (difference of less than one taxa between treatments). Therefore, in habitats whose productivity, regional species pool, and population growth rates would otherwise suggest a response to disturbances as predicted by the IDH, minor differences between successional stages may result in richness patterns that deviate from those predicted by the IDH.

Denitrifying Bioreactors Resist Disturbance from Fluctuating Water Levels

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Sarah K. Hathaway

2017-06-01

Full Text Available Nitrate can be removed from wastewater streams, including subsurface agricultural drainage systems, using woodchip bioreactors to promote microbial denitrification. However, the variations in water flow in these systems could make reliable performance from this microbially-mediated process a challenge. In the current work, the effects of fluctuating water levels on nitrate removal, denitrifying activity, and microbial community composition in laboratory-scale bioreactors were investigated. The performance was sensitive to changing water level. An average of 31% nitrate was removed at high water level and 59% at low water level, despite flow adjustments to maintain a constant theoretical hydraulic retention time. The potential activity, as assessed through denitrifying enzyme assays, averaged 0.0008 mg N2O-N/h/dry g woodchip and did not show statistically significant differences between reactors, sampling depths, or operational conditions. In the denitrifying enzyme assays, nitrate removal consistently exceeded nitrous oxide production. The denitrifying bacterial communities were not significantly different from each other, regardless of water level, meaning that the denitrifying bacterial community did not change in response to disturbance. The overall bacterial communities, however, became more distinct between the two reactors when one reactor was operated with periodic disturbances of changing water height, and showed a stronger effect at the most severely disturbed location. The communities were not distinguishable, though, when comparing the same location under high and low water levels, indicating that the communities in the disturbed reactor were adapted to fluctuating conditions rather than to high or low water level. Overall, these results describe a biological treatment process and microbial community that is resistant to disturbance via water level fluctuations.

Cytogenetic studies in femalie X-ray assistants with menstrual disturbances

International Nuclear Information System (INIS)

Marinova, G.; Dimcheva, M.; Kincheva, V.

1976-01-01

Cytogenetic analyses were performed in thirty, otherwise genitally and extragenitally unaffected, female X-ray assistants with menstrual disturbances (oligomenorrhea, secondary amenorrhea, irregular bleedings, hypermenorrhea) developing in the course of occupational experience under intermittent, chronic, low-level exposure conditions, the dose accumulated remaining below the maximum permissible dose. Seventeen of these subjects showed changes in chromosome constitution, namely: aneuploidy, up to 34,2%; breaks, 2 - 14,3%; gaps, 5,6 - 16,7;; and dicentrics, in one case, 2,8%. Increase in occupational experience was found to be associated with increase in percentage of menstrual disturbances and in chromosome aberrations. (author)

Study of brain metabolism using positron emission computed tomography

Energy Technology Data Exchange (ETDEWEB)

Heiss, W D

1983-03-21

Positron emission tomography permits the three-dimensional regional measurement of metabolism and blood flow in the brain. For the determination of cerebral metabolic rates of glucose by PET /sup 18/fluordeoxyglucose is usually applied: cerebral metabolic rate of glucose was found to be 36 to 47 ..mu..mol/100 g/min in the grey matter and 23 to 29 ..mu..mol/100 g/min in the white matter of normal volunteers. During physiologic activation metabolic rate of glucose is increased in the respective brain areas in relation to the strength and complexity of the stimulation. In patients suffering from ischaemic stroke glucose metabolism is markedly decreased within the infarction. Additonally, glucose metabolism is reduced by 20% in morphologically intact areas of the homolateral cortex, in the basal ganglia, in the cortical area contralateral to the infarction and in the contralateral cerebellum. This remote reduction of glucose utilization is probably caused by functional inactivation of these brain structures; it could be responsible for the diffuse organic syndrome in stroke victims not caused by the focal lesion. In patients suffering from dementia of the multi-infarct type and of the Alzheimer type glucose metabolism is reduced; the lesions in Alzheimer cases are most prominent in partietal and frontal cortical areas. In Chorea Huntington cases glucose metabolism is primarily disturbed in the striate, especially in the caudate nucleus; in these cases the metabolic disturbance can be detected earlier than the atrophy in computed tomograms. Disturbances of glucose and oxygen utilization are not necessary causes, but may also be sequelae od functional impairment. Additional information on pathogentic mechanisms may be obtained by the investigation of the protein synthesis.

Anthropogenic disturbance in tropical forests can double biodiversity loss from deforestation.

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Barlow, Jos; Lennox, Gareth D; Ferreira, Joice; Berenguer, Erika; Lees, Alexander C; Mac Nally, Ralph; Thomson, James R; Ferraz, Silvio Frosini de Barros; Louzada, Julio; Oliveira, Victor Hugo Fonseca; Parry, Luke; Solar, Ricardo Ribeiro de Castro; Vieira, Ima C G; Aragão, Luiz E O C; Begotti, Rodrigo Anzolin; Braga, Rodrigo F; Cardoso, Thiago Moreira; de Oliveira, Raimundo Cosme; Souza, Carlos M; Moura, Nárgila G; Nunes, Sâmia Serra; Siqueira, João Victor; Pardini, Renata; Silveira, Juliana M; Vaz-de-Mello, Fernando Z; Veiga, Ruan Carlo Stulpen; Venturieri, Adriano; Gardner, Toby A

2016-07-07

Concerted political attention has focused on reducing deforestation, and this remains the cornerstone of most biodiversity conservation strategies. However, maintaining forest cover may not reduce anthropogenic forest disturbances, which are rarely considered in conservation programmes. These disturbances occur both within forests, including selective logging and wildfires, and at the landscape level, through edge, area and isolation effects. Until now, the combined effect of anthropogenic disturbance on the conservation value of remnant primary forests has remained unknown, making it impossible to assess the relative importance of forest disturbance and forest loss. Here we address these knowledge gaps using a large data set of plants, birds and dung beetles (1,538, 460 and 156 species, respectively) sampled in 36 catchments in the Brazilian state of Pará. Catchments retaining more than 69–80% forest cover lost more conservation value from disturbance than from forest loss. For example, a 20% loss of primary forest, the maximum level of deforestation allowed on Amazonian properties under Brazil’s Forest Code, resulted in a 39–54% loss of conservation value: 96–171% more than expected without considering disturbance effects. We extrapolated the disturbance-mediated loss of conservation value throughout Pará, which covers 25% of the Brazilian Amazon. Although disturbed forests retained considerable conservation value compared with deforested areas, the toll of disturbance outside Pará’s strictly protected areas is equivalent to the loss of 92,000–139,000 km2 of primary forest. Even this lowest estimate is greater than the area deforested across the entire Brazilian Amazon between 2006 and 2015 (ref. 10). Species distribution models showed that both landscape and within-forest disturbances contributed to biodiversity loss, with the greatest negative effects on species of high conservation and functional value. These results demonstrate an urgent need

Bicarbonate sensing in mouse cortical astrocytes during extracellular acid/base disturbances

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Naoshin, Zinnia; Defren, Sabrina; Schmaelzle, Jana; Weber, Tobias; Schneider, Hans‐Peter

2017-01-01

Key points The present study suggests that the electrogenic sodium–bicarbonate cotransporter, NBCe1, supported by carbonic anhydrase II, CAII, provides an efficient mechanism of bicarbonate sensing in cortical astrocytes. This mechanism is proposed to play a major role in setting the pHi responses to extracellular acid/base challenges in astrocytes.A decrease in extracellular [HCO3 −] during isocapnic acidosis and isohydric hypocapnia, or an increase in intracellular [HCO3 −] during hypercapnic acidosis, was effectively sensed by NBCe1, which carried bicarbonate out of the cells under these conditions, and caused an acidification and sodium fall in WT astrocytes, but not in NBCe1‐knockout astrocytes.Isocapnic acidosis, hypercapnic acidosis and isohydric hypocapnia evoked inward currents in NBCe1‐ and CAII‐expressing Xenopus laevis oocytes, but not in native oocytes, suggesting that NBCe1 operates in the outwardly directed mode under these conditions consistent with our findings in astrocytes.We propose that bicarbonate sensing of astrocytes may have functional significance during extracellular acid/base disturbances in the brain, as it not only alters intracellular pH/[HCO3 −]‐dependent functions of astrocytes, but also modulates the extracellular pH/[HCO3 −] in brain tissue. Abstract Extracellular acid/base status of the mammalian brain undergoes dynamic changes during many physiological and pathological events. Although intracellular pH (pHi) of astrocytes responds to extracellular acid/base changes, the mechanisms mediating these changes have remained unresolved. We have previously shown that the electrogenic sodium–bicarbonate cotransporter, NBCe1, is a high‐affinity bicarbonate carrier in cortical astrocytes. In the present study, we investigated whether NBCe1 plays a role in bicarbonate sensing in astrocytes, and in determining the pHi responses to extracellular acid/base challenges. We measured changes in intracellular H+ and Na+ in

Adaptive tracking control of leader-following linear multi-agent systems with external disturbances

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Lin, Hanquan; Wei, Qinglai; Liu, Derong; Ma, Hongwen

2016-10-01

In this paper, the consensus problem for leader-following linear multi-agent systems with external disturbances is investigated. Brownian motions are used to describe exogenous disturbances. A distributed tracking controller based on Riccati inequalities with an adaptive law for adjusting coupling weights between neighbouring agents is designed for leader-following multi-agent systems under fixed and switching topologies. In traditional distributed static controllers, the coupling weights depend on the communication graph. However, coupling weights associated with the feedback gain matrix in our method are updated by state errors between neighbouring agents. We further present the stability analysis of leader-following multi-agent systems with stochastic disturbances under switching topology. Most traditional literature requires the graph to be connected all the time, while the communication graph is only assumed to be jointly connected in this paper. The design technique is based on Riccati inequalities and algebraic graph theory. Finally, simulations are given to show the validity of our method.

Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment.

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Sun, Hongtao; Zheng, Maohua; Wang, Yanmin; Diao, Yunfeng; Zhao, Wanyong; Wei, Zhengjun

2016-01-01

The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2) in the course of mild hypothermia treatment (MHT) for treating severe traumatic brain injury (sTBI). There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP), jugular venous oxygen saturation (SjvO2), and cerebral perfusion pressure (CPP) were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome.

Analysis of disturbance

International Nuclear Information System (INIS)

Ciala-Wein, H.; Stegmaier, W.

1977-12-01

The analyses of disturbances are the supposition for the development of processes and plants. They are very important in the field of nuclear testing plants. In this report are described the possibilities to register the circumstances of the disturbance in a pilot waste processing facility and a computer programme to interpret them. This is a first scheme and it will be necessary to complete it. (orig.) [de

Quantifying Forest and Coastal Disturbance from Industrial Mining Using Satellite Time Series Analysis Under Very Cloudy Conditions

Science.gov (United States)

Alonzo, M.; Van Den Hoek, J.; Ahmed, N.

2015-12-01

The open-pit Grasberg mine, located in the highlands of Western Papua, Indonesia, and operated by PT Freeport Indonesia (PT-FI), is among the world's largest in terms of copper and gold production. Over the last 27 years, PT-FI has used the Ajkwa River to transport an estimated 1.3 billion tons of tailings from the mine into the so-called Ajkwa Deposition Area (ADA). The ADA is the product of aggradation and lateral expansion of the Ajkwa River into the surrounding lowland rainforest and mangroves, which include species important to the livelihoods of indigenous Papuans. Mine tailings that do not settle in the ADA disperse into the Arafura Sea where they increase levels of suspended particulate matter (SPM) and associated concentrations of dissolved copper. Despite the mine's large-scale operations, ecological impact of mine tailings deposition on the forest and estuarial ecosystems have received minimal formal study. While ground-based inquiries are nearly impossible due to access restrictions, assessment via satellite remote sensing is promising but hindered by extreme cloud cover. In this study, we characterize ridgeline-to-coast environmental impacts along the Ajkwa River, from the Grasberg mine to the Arafura Sea between 1987 and 2014. We use "all available" Landsat TM and ETM+ images collected over this time period to both track pixel-level vegetation disturbance and monitor changes in coastal SPM levels. Existing temporal segmentation algorithms are unable to assess both acute and protracted trajectories of vegetation change due to pervasive cloud cover. In response, we employ robust, piecewise linear regression on noisy vegetation index (NDVI) data in a manner that is relatively insensitive to atmospheric contamination. Using this disturbance detection technique we constructed land cover histories for every pixel, based on 199 image dates, to differentiate processes of vegetation decline, disturbance, and regrowth. Using annual reports from PT-FI, we show

Mental status in pregnant women with brain injury sequels

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A. A. Volynkin

2017-01-01

Full Text Available Objective: to investigate emotional disturbances in pregnant women with sequels of brain injury (BI.Patients and methods. A total of 47 pregnant women with a history of BI, who had been admitted to the Department of Obstetric Physiology, Moscow Regional Research Institute of Obstetrics and Gynecology, in 2013-2015, were examined. All the patients underwent a comprehensive neurological and neuropsychological examination using the Miltidimensional Fatigue Inventory-20 (MFI-20, the Hospital Anxiety and Depression Scale (HADS, and the Spielberg-Hanin Situational and Personal Anxiety Scale.Results. The pregnant women with BI sequels were found to have emotional changes involving asthenic, anxiety, and depressive components. In these women, anxiety symptoms were most common (53.3%; psychoemotional disturbance and asthenic and depressive manifestations were identified in 23.4 and 14.9% of cases. This investigation first verified the structural (situational and personal components of post-traumatic anxiety syndrome in the pregnant women. It revealed that an increased level of situational anxiety and physical symptoms of fatigue was observed in brain concussion sequels; and after brain contusion (BC, alarm acquired personality traits, asthenia was of a mental nature. In the pregnant women with BI sequels, depression was diagnosed only at the subclinical level and more often noted after BC (p=0.0473. 

Metabolic mapping of the effects of the antidepressant fluoxetine on the brains of congenitally helpless rats

OpenAIRE

Shumake, Jason; Colorado, Rene A.; Barrett, Douglas W.; Gonzalez-Lima, F.

2010-01-01

Antidepressants require adaptive brain changes before efficacy is achieved, and they may impact the affectively disordered brain differently than the normal brain. We previously demonstrated metabolic disturbances in limbic and cortical regions of the congenitally helpless rat, a model of susceptibility to affective disorder, and we wished to test whether administration of fluoxetine would normalize these metabolic differences. Fluoxetine was chosen because it has become a first-line drug for...

Hypothalamus-Related Resting Brain Network Underlying Short-Term Acupuncture Treatment in Primary Hypertension

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Hongyan Chen

2013-01-01

Full Text Available The present study attempted to explore modulated hypothalamus-seeded resting brain network underlying the cardiovascular system in primary hypertensive patients after short-term acupuncture treatment. Thirty right-handed patients (14 male were divided randomly into acupuncture and control groups. The acupuncture group received a continuous five-day acupuncture treatment and undertook three resting-state fMRI scans and 24-hour ambulatory blood pressure monitoring (ABPM as well as SF-36 questionnaires before, after, and one month after acupuncture treatment. The control group undertook fMRI scans and 24-hour ABPM. For verum acupuncture, average blood pressure (BP and heart rate (HR decreased after treatment but showed no statistical differences. There were no significant differences in BP and HR between the acupuncture and control groups. Notably, SF-36 indicated that bodily pain (P = 0.005 decreased and vitality (P = 0.036 increased after acupuncture compared to the baseline. The hypothalamus-related brain network showed increased functional connectivity with the medulla, brainstem, cerebellum, limbic system, thalamus, and frontal lobes. In conclusion, short-term acupuncture did not decrease BP significantly but appeared to improve body pain and vitality. Acupuncture may regulate the cardiovascular system through a complicated brain network from the cortical level, the hypothalamus, and the brainstem.

CONSEQUENCES OF SEVERE TRAUMATIC BRAIN INJURY IN CHILDREN AND THEIR TREATMENT

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N.N. Zavadenko

2006-01-01

Full Text Available Traumatic brain injury is one of the major causes for invalidization in children. The research purpose is an integrated study of consequences of severe and moderate closed traumatic brain injury in children and evaluation of their dynamics during therapy by means of a no tropic medication — cerebrolysin (Ebewe Pharma, Austria. The total of 283 children aged from 4 to 14 years were examined in the longaterm period of severe and moderate closed traumatic brain injury, from 6 months to 4 years after injury. Their neurological status was characterized by nona specific focal symptoms along with evident motor coordination disturbances, elements of dynamic and staticoloa comotory ataxia, reduction in execution speed of serial movements. Statistically significant differences with ageamatched controls were confirmed for measures of acousticaverbal memory and sustained attention. Posttraumatic epilepsy developed in 16 (5,7% patients with the onset of secondarily generalized seizures in 4–12 months following the injury. Effectiveness of the no tropic medication was evaluated in 60 patients aged from 7 to 12 years, who were distributed into 2 equal groups. The research has confirmed a positive effect of no tropic medication in the treatment of traumatic brain injury consequences manifested in the regression of headaches, fatigue, motor coordination disturbances along with improvements of memory, attention, intellectual performance rates, as well as EEG characteristics.Key words: traumatic brain injury, consequences, children, therapy, nootropic medications.

Different shades of default mode disturbance in schizophrenia: Subnodal covariance estimation in structure and function.

Science.gov (United States)

Lefort-Besnard, Jérémy; Bassett, Danielle S; Smallwood, Jonathan; Margulies, Daniel S; Derntl, Birgit; Gruber, Oliver; Aleman, Andre; Jardri, Renaud; Varoquaux, Gaël; Thirion, Bertrand; Eickhoff, Simon B; Bzdok, Danilo

2018-02-01

Schizophrenia is a devastating mental disease with an apparent disruption in the highly associative default mode network (DMN). Interplay between this canonical network and others probably contributes to goal-directed behavior so its disturbance is a candidate neural fingerprint underlying schizophrenia psychopathology. Previous research has reported both hyperconnectivity and hypoconnectivity within the DMN, and both increased and decreased DMN coupling with the multimodal saliency network (SN) and dorsal attention network (DAN). This study systematically revisited network disruption in patients with schizophrenia using data-derived network atlases and multivariate pattern-learning algorithms in a multisite dataset (n = 325). Resting-state fluctuations in unconstrained brain states were used to estimate functional connectivity, and local volume differences between individuals were used to estimate structural co-occurrence within and between the DMN, SN, and DAN. In brain structure and function, sparse inverse covariance estimates of network coupling were used to characterize healthy participants and patients with schizophrenia, and to identify statistically significant group differences. Evidence did not confirm that the backbone of the DMN was the primary driver of brain dysfunction in schizophrenia. Instead, functional and structural aberrations were frequently located outside of the DMN core, such as in the anterior temporoparietal junction and precuneus. Additionally, functional covariation analyses highlighted dysfunctional DMN-DAN coupling, while structural covariation results highlighted aberrant DMN-SN coupling. Our findings reframe the role of the DMN core and its relation to canonical networks in schizophrenia. We thus underline the importance of large-scale neural interactions as effective biomarkers and indicators of how to tailor psychiatric care to single patients. © 2017 Wiley Periodicals, Inc.

Visually Determined Soil Disturbance Classes Used as Indices of Forest Harvesting Disturbance

Science.gov (United States)

W. Michael Aust; James A. Burger; Emily A. Carter; David P. Preston; Steven C. Patterson

1998-01-01

Visual estimates of soil and site disturbances are used by foresters, soil scientists, logging supervisors. and machinery operators to minimize harvest disturbances to forest sites, to evaluate compliance with forestry Best Management Practices (BMPs), and to determine the need for ameliorative practices such as tnechanical site preparation. Although estimates are...

Left brain, right brain: facts and fantasies.

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Michael C Corballis

2014-01-01

Full Text Available Handedness and brain asymmetry are widely regarded as unique to humans, and associated with complementary functions such as a left-brain specialization for language and logic and a right-brain specialization for creativity and intuition. In fact, asymmetries are widespread among animals, and support the gradual evolution of asymmetrical functions such as language and tool use. Handedness and brain asymmetry are inborn and under partial genetic control, although the gene or genes responsible are not well established. Cognitive and emotional difficulties are sometimes associated with departures from the "norm" of right-handedness and left-brain language dominance, more often with the absence of these asymmetries than their reversal.

Left brain, right brain: facts and fantasies.

Science.gov (United States)

Corballis, Michael C

2014-01-01

Handedness and brain asymmetry are widely regarded as unique to humans, and associated with complementary functions such as a left-brain specialization for language and logic and a right-brain specialization for creativity and intuition. In fact, asymmetries are widespread among animals, and support the gradual evolution of asymmetrical functions such as language and tool use. Handedness and brain asymmetry are inborn and under partial genetic control, although the gene or genes responsible are not well established. Cognitive and emotional difficulties are sometimes associated with departures from the "norm" of right-handedness and left-brain language dominance, more often with the absence of these asymmetries than their reversal.

Brain-computer interfacing under distraction: an evaluation study

Science.gov (United States)

Brandl, Stephanie; Frølich, Laura; Höhne, Johannes; Müller, Klaus-Robert; Samek, Wojciech

2016-10-01

Objective. While motor-imagery based brain-computer interfaces (BCIs) have been studied over many years by now, most of these studies have taken place in controlled lab settings. Bringing BCI technology into everyday life is still one of the main challenges in this field of research. Approach. This paper systematically investigates BCI performance under 6 types of distractions that mimic out-of-lab environments. Main results. We report results of 16 participants and show that the performance of the standard common spatial patterns (CSP) + regularized linear discriminant analysis classification pipeline drops significantly in this ‘simulated’ out-of-lab setting. We then investigate three methods for improving the performance: (1) artifact removal, (2) ensemble classification, and (3) a 2-step classification approach. While artifact removal does not enhance the BCI performance significantly, both ensemble classification and the 2-step classification combined with CSP significantly improve the performance compared to the standard procedure. Significance. Systematically analyzing out-of-lab scenarios is crucial when bringing BCI into everyday life. Algorithms must be adapted to overcome nonstationary environments in order to tackle real-world challenges.

Emotional disturbances among adult diabetic patients attending a diabetic clinic in a Malaysian general hospital

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Ali SabriRadeef1, Ramli Musa, NikNurFatnoonBintiNik Ahmad, Ghasak Ghazi Faisal

2014-11-01

Full Text Available Introduction: Emotional disturbances such as depression, anxiety and stress play an important role in the management of diabetes mellitus since their presence can adversely affect glycemic control, quality of life and compliance with medications. Despite this, emotional disturbances are consistently under-diagnosed and under-treated by physicians in general practice. Objectives: This study aims to determine the prevalence and severity of emotional disturbances among diabetic patients Methodology: This is a cross sectional study conducted on a sample of 200 patients with diabetes mellitus attending the diabetic clinic at the Hospital Tengku Ampuan Afzan, Pahang state, Malaysia. The prevalence and severity of depressive, anxiety and stress symptoms were assessed in those diabetic patients by using the self-rating Bahasa Malaysia version of the Depression, Anxiety and Stress Scales (DASS-42. Results: The prevalence of depression, anxiety, and stress among diabetic patients was 13.5%, 28%, 11% respectively. Most of the patients with emotional disturbances had moderate depression and anxiety symptoms. However, stress symptoms were mild. Although females showed higher prevalence of emotional disturbances, only anxiety was significantly higher than males. Conclusion: Diabetic patients are at risk to develop psychiatric illnesses in the form of depression, anxiety and stress. Anxiety symptoms were more prominent than depression and stress in diabetic patients

Children's sleep disturbance scale in differentiating neurological disorders.

Science.gov (United States)

Cohen, Rony; Halevy, Ayelet; Shuper, Avinoam

2013-12-01

We use the Sleep Disturbance Scale for Children (SDSC) routinely as a tool for evaluating children's sleep quality in our pediatric neurology clinic. We analyzed at its ability to detect sleep disturbances distinctive to selected neurological disorders. One-hundred and eighty-six children (age range 2-18 years) who were evaluated by the SDSC questionnaire were divided into three groups according to their principal diagnosis: epilepsy, attention deficit hyperactivity disorder, or others. Their responses were analyzed. The average frequency of abnormal total sleep score was 26.9%. The most frequent sleep disorders were excessive somnolence (25.3%), initiating and maintaining sleep (24.7%), and arousal/nightmares (23.1%). There were no significant group differences for total scores or sleep disorder-specific scores; although a sleep-wake transition disorder was more frequent among children with epilepsy (31%). A literature search revealed that the frequency of abnormal total scores in several neurological disorders (e.g., epilepsy, cerebral palsy) ranges between 20% and 30%. The mechanism underlying sleep disturbances in many neurological disorders may be unrelated to that of the primary disease but rather originate from nonspecific or environmental factors (e.g., familial/social customs and habits, temperament, psychological parameters). Although the SDSC is noninformative for studying the effect of a specific neurological disorder on sleep, we still recommend its implementation for screening for sleep disturbances in children with neurological abnormalities. Copyright © 2013 Elsevier Inc. All rights reserved.

Modulating Conscious Movement Intention by Noninvasive Brain Stimulation and the Underlying Neural Mechanisms

OpenAIRE

Douglas, Zachary H.; Maniscalco, Brian; Hallett, Mark; Wassermann, Eric M.; He, Biyu J.

2015-01-01

Conscious intention is a fundamental aspect of the human experience. Despite long-standing interest in the basis and implications of intention, its underlying neurobiological mechanisms remain poorly understood. Using high-definition transcranial DC stimulation (tDCS), we observed that enhancing spontaneous neuronal excitability in both the angular gyrus and the primary motor cortex caused the reported time of conscious movement intention to be ∼60–70 ms earlier. Slow brain waves recorded ∼2–...

DISTURBANCES OF BIOLOGICAL RHYTHMS IN A RAT CHRONIC MILD STRESS MODEL OF DEPRESSION

DEFF Research Database (Denmark)

Christiansen, Sofie; Wiborg, Ove; Bouzinova, Elena

validated animal model of depression, the chronic mild stress model (CMS). Depression-like and control rats were killed by decapitation within 24 h. Trunk blood, brain and liver tissue were collected. The quantitative amount of plasma corticosterone and melatonin were measured using an ELISA and RIA kit...... that depression-like animals showed an abnormal circadian rhythm in the liver and in subregions of the rat brains related to depression. However, the SCN was partly protected against stress. We found an increased level of corticosteron and melatonin, in the depression-like animals as well as a shifted circadian......Aim: The focus of this project is to identify biomarkers related to circadian disturbances in major depressive disorder. Background: A large body of clinical data from depressed individuals showed that sleep, temperature, hormones, physiological states and moodchanges are consistent...

Anti-disturbance rapid vibration suppression of the flexible aerial refueling hose

Science.gov (United States)

Su, Zikang; Wang, Honglun; Li, Na

2018-05-01

As an extremely dangerous phenomenon in autonomous aerial refueling (AAR), the flexible refueling hose vibration caused by the receiver aircraft's excessive closure speed should be suppressed once it appears. This paper proposed a permanent magnet synchronous motor (PMSM) based refueling hose servo take-up system for the vibration suppression of the flexible refueling hose. A rapid back-stepping based anti-disturbance nonsingular fast terminal sliding mode (NFTSM) control scheme with a specially established finite-time convergence NFTSM observer is proposed for the PMSM based hose servo take-up system under uncertainties and disturbances. The unmeasured load torque and other disturbances in the PMSM system are reconstituted by the NFTSM observer and to be compensated during the controller design. Then, with the back-stepping technique, a rapid anti-disturbance NFTSM controller is proposed for the PMSM angular tracking to improve the tracking error convergence speed and tracking precision. The proposed vibration suppression scheme is then applied to PMSM based hose servo take-up system for the refueling hose vibration suppression in AAR. Simulation results show the proposed scheme can suppress the hose vibration rapidly and accurately even the system is exposed to strong uncertainties and probe position disturbances, it is more competitive in tracking accuracy, tracking error convergence speed and robustness.

Drug-Induced Apoptosis: Mechanism by which Alcohol and Many Other Drugs Can Disrupt Brain Development

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John W. Olney

2013-07-01

Full Text Available Maternal ingestion of alcohol during pregnancy can cause a disability syndrome termed Fetal Alcohol Spectrum Disorder (FASD, which may include craniofacial malformations, structural pathology in the brain, and a variety of long-term neuropsychiatric disturbances. There is compelling evidence that exposure to alcohol during early embryogenesis (4th week of gestation can cause excessive death of cell populations that are essential for normal development of the face and brain. While this can explain craniofacial malformations and certain structural brain anomalies that sometimes accompany FASD, in many cases these features are absent, and the FASD syndrome manifests primarily as neurobehavioral disorders. It is not clear from the literature how alcohol causes these latter manifestations. In this review we will describe a growing body of evidence documenting that alcohol triggers widespread apoptotic death of neurons and oligodendroglia (OLs in the developing brain when administered to animals, including non-human primates, during a period equivalent to the human third trimester of gestation. This cell death reaction is associated with brain changes, including overall or regional reductions in brain mass, and long-term neurobehavioral disturbances. We will also review evidence that many drugs used in pediatric and obstetric medicine, including general anesthetics (GAs and anti-epileptics (AEDs, mimic alcohol in triggering widespread apoptotic death of neurons and OLs in the third trimester-equivalent animal brain, and that human children exposed to GAs during early infancy, or to AEDs during the third trimester of gestation, have a significantly increased incidence of FASD-like neurobehavioral disturbances. These findings provide evidence that exposure of the developing human brain to GAs in early infancy, or to alcohol or AEDs in late gestation, can cause FASD-like neurodevelopmental disability syndromes. We propose that the mechanism by which

Brain-to-brain coupling during handholding is associated with pain reduction.

Science.gov (United States)

Goldstein, Pavel; Weissman-Fogel, Irit; Dumas, Guillaume; Shamay-Tsoory, Simone G

2018-03-13

The mechanisms underlying analgesia related to social touch are not clear. While recent research highlights the role of the empathy of the observer to pain relief in the target, the contribution of social interaction to analgesia is unknown. The current study examines brain-to-brain coupling during pain with interpersonal touch and tests the involvement of interbrain synchrony in pain alleviation. Romantic partners were assigned the roles of target (pain receiver) and observer (pain observer) under pain-no-pain and touch-no-touch conditions concurrent with EEG recording. Brain-to-brain coupling in alpha-mu band (8-12 Hz) was estimated by a three-step multilevel analysis procedure based on running window circular correlation coefficient and post hoc power of the findings was calculated using simulations. Our findings indicate that hand-holding during pain administration increases brain-to-brain coupling in a network that mainly involves the central regions of the pain target and the right hemisphere of the pain observer. Moreover, brain-to-brain coupling in this network was found to correlate with analgesia magnitude and observer's empathic accuracy. These findings indicate that brain-to-brain coupling may be involved in touch-related analgesia.

Automated attribution of remotely-sensed ecological disturbances using spatial and temporal characteristics of common disturbance classes.

Science.gov (United States)

Cooper, L. A.; Ballantyne, A.

2017-12-01

Forest disturbances are critical components of ecosystems. Knowledge of their prevalence and impacts is necessary to accurately describe forest health and ecosystem services through time. While there are currently several methods available to identify and describe forest disturbances, especially those which occur in North America, the process remains inefficient and inaccessible in many parts of the world. Here, we introduce a preliminary approach to streamline and automate both the detection and attribution of forest disturbances. We use a combination of the Breaks for Additive Season and Trend (BFAST) detection algorithm to detect disturbances in combination with supervised and unsupervised classification algorithms to attribute the detections to disturbance classes. Both spatial and temporal disturbance characteristics are derived and utilized for the goal of automating the disturbance attribution process. The resulting preliminary algorithm is applied to up-scaled (100m) Landsat data for several different ecosystems in North America, with varying success. Our results indicate that supervised classification is more reliable than unsupervised classification, but that limited training data are required for a region. Future work will improve the algorithm through refining and validating at sites within North America before applying this approach globally.

Sleep Disturbances in Mood Disorders.

Science.gov (United States)

Rumble, Meredith E; White, Kaitlin Hanley; Benca, Ruth M

2015-12-01

The article provides an overview of common and differentiating self-reported and objective sleep disturbances seen in mood-disordered populations. The importance of considering sleep disturbances in the context of mood disorders is emphasized, because a large body of evidence supports the notion that sleep disturbances are a risk factor for onset, exacerbation, and relapse of mood disorders. In addition, potential mechanisms for sleep disturbance in depression, other primary sleep disorders that often occur with mood disorders, effects of antidepressant and mood-stabilizing drugs on sleep, and the adjunctive effect of treating sleep in patients with mood disorders are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

99mTc-HMPAO perfusion indices and brain-mapping in stroke patients

International Nuclear Information System (INIS)

Minchev, D.; Klisarova, A.

1997-01-01

It is the purpose of the study to establish correlations between 99mTc-HMPAO (hexamethylpropylenaminoxym) perfusion indices and changes in brain-mapping among patients with acute stroke. Forty-six patients with definitely proved stroke syndrome are investigated in the first 72 hours and 15 days after the onset of cerebrovascular accident using clinical, neuro-physiological and 99mTc-HMPAO SPECT methods. Regional and hemispheric perfusion asymmetry correlate with the brain-mapping cerebral disturbance (p < 0.001). In patients presenting focal hypoperfusion there is a significant correlation between perfusion indices and local EEG disturbance (r = 0.87). The dynamic study demonstrates a significant correlation between perfusion indices and electrical cerebral disturbance in the first 72 hours after the onset of the cerebrovascular accident. Fifteen days later no such correlation is documented. The obtained results demonstrate the essential practical bearing of 99mTc-HMPAO SPECT indices on the objective assessment of perfusion hemispheric and regional asymmetry in stroke patients, and the possibility of being used for indirect estimation of the regional cerebral blood flow in acute stroke patients against the background of visual and quantitative EEG changes (author)

[A 53-year-old man with herpes encephalitis showing acceleration of improvement in higher brain function after general anesthesia with sevoflurane: a case report].

Science.gov (United States)

Togashi, Naohiko; Kaida, Kenichi; Hongo, Yu; Ogawa, Go; Ishikawa, Yukinobu; Takeda, Katsuhiko; Kamakura, Keiko

2014-01-01

We experienced a right-handed 53-year-old man who presented with disturbance of consciousness and fever. Herpes simplex encephalitis (HSE) was diagnosed based on the detection of herpes simplex virus DNA in the cerebrospinal fluid. The administration of acyclovir for 42 days improved his consciousness level. Drowsiness, fever and seizures reappeared 20 days after stopping acyclovir treatment (day 67) and he responded well to vidarabine and methylprednisolone pulse therapy. An assessment of aphasia on day 98 revealed transcortical sensory aphasia. Brain MRI showed lesion in the left temporal lobe, bilateral insular cortexes and bilateral frontal lobe. His higher brain dysfunction continued. On day 156, he underwent hip replacement arthroplasty under general anesthesia sevoflurane. His higher brain dysfunction rapidly improved thereafter. We concluded that the accelerated improvement in our patient's higher brain function was related to the protective effect of sevoflurane. Some reports also show the protective effects of sevoflurane in experimental allergic encephalomyelitis by inhibition of T cell activation. These protective and anti-inflammatory effects may explain the accelerated improvement in higher brain function after general anesthesia.

Numerical study of wave disturbance in liquid cooling film

Directory of Open Access Journals (Sweden)

S.R. Shine

2013-06-01

Full Text Available Transient numerical simulations are carried out to investigate the liquid-gas interface characteristics associated with liquid film cooling flows. A two-dimensional axisymmetric multi-phase numerical model using finite volume formulation is developed. The model has been validated against available experimental data for liquid-film cooling flows inside tubes. The model has been used to predict the interface characteristics for a variety of imposed parameters and momentum flux ratios under cold flow conditions wherein both the coolant and mainstream are maintained at the same temperature. Disturbance waves are observed at the liquid-gas interface for coolant flows above a critical value and after a finite distance from the inlet. The distance toward the wave inception point increased with the increase of momentum flux ratio. However, at higher momentum flux ratios, the properties of the disturbance waves did not vary significantly. The parameters related to the liquid-gas interface waves, namely, wave velocity, frequency, amplitude and wave length have been analyzed in detail. Analysis indicates that the liquid entrainment is due to the shearing of the disturbance wave crest.

Alcohol and the sleeping brain.

Science.gov (United States)

Colrain, Ian M; Nicholas, Christian L; Baker, Fiona C

2014-01-01

Alcohol acts as a sedative that interacts with several neurotransmitter systems important in the regulation of sleep. Acute administration of large amounts of alcohol prior to sleep leads to decreased sleep-onset latency and changes in sleep architecture early in the night, when blood alcohol levels are high, with subsequent disrupted, poor-quality sleep later in the night. Alcohol abuse and dependence are associated with chronic sleep disturbance, lower slow-wave sleep, and more rapid-eye-movement sleep than normal, that last long into periods of abstinence and may play a role in relapse. This chapter outlines the evidence for acute and chronic alcohol effects on sleep architecture and sleep electroencephalogram, evidence for tolerance with repeated administration, and possible underlying neurochemical mechanisms for alcohol's effects on sleep. Also discussed are sex differences as well as effects of alcohol on sleep homeostasis and circadian regulation. Evidence for the role of sleep disruption as a risk factor for developing alcohol dependence is discussed in the context of research conducted in adolescents. The utility of sleep-evoked potentials in the assessment of the effects of alcoholism on sleep and the brain and in abstinence-mediated recovery is also outlined. The chapter concludes with a series of questions that need to be answered to determine the role of sleep and sleep disturbance in the development and maintenance of problem drinking and the potential beneficial effects of the treatment of sleep disorders for maintenance of abstinence in alcoholism. © 2014 Elsevier B.V. All rights reserved.

Investigating the correlation between computerized tomography changes and quantitative consciousness disturbances in stroke patients

International Nuclear Information System (INIS)

Toneva, Yu.; Manchev, I.; Tsolova, M.

1997-01-01

One-hundred and nine patients undergo computerized tomographic (CT) and clinical investigations. The correlation between CT finding and quantitative consciousness disturbances has been studied. The somatic, neurologic and mental states are evaluated, and the changes in consciousness are classified according to a 4-degree rating system adopted in this country, namely: obnubilation, somnolence, sopor and coma. For the purpose a computerized tomograph CE 10000 is used. Cerebral infarctions in the right middle cerebral artery pool predominate. Here the disturbances are of a milder degree - obnubilation and somnolence. In stroke syndrome cases the states of sopor and coma are more frequent which may be explained with the rather severely manifested brain edema. In either form of cerebrovascular disease the quantitative disorders of consciousness are not dependent on the location of the accident in the dominant hemisphere. They are directly related to the CT documented size of pathological focus

Global synchronization of general delayed complex networks with stochastic disturbances

International Nuclear Information System (INIS)

Tu Li-Lan

2011-01-01

In this paper, global synchronization of general delayed complex networks with stochastic disturbances, which is a zero-mean real scalar Wiener process, is investigated. The networks under consideration are continuous-time networks with time-varying delay. Based on the stochastic Lyapunov stability theory, Ito's differential rule and the linear matrix inequality (LMI) optimization technique, several delay-dependent synchronous criteria are established, which guarantee the asymptotical mean-square synchronization of drive networks and response networks with stochastic disturbances. The criteria are expressed in terms of LMI, which can be easily solved using the Matlab LMI Control Toolbox. Finally, two examples show the effectiveness and feasibility of the proposed synchronous conditions. (general)

Morphology in the total electron content under geomagnetic disturbed conditions: results from global ionosphere maps

Directory of Open Access Journals (Sweden)

Zhao Biqiang

2007-07-01

Full Text Available Using 8-year global ionosphere maps (GIMs of TEC products from the Jet Propulsion Laboratory (JPL, we make a statistical study on the morphology of the global ionospheric behaviors with respect to the geomagnetic disturbances. Results show that the behaviors of TEC during geomagnetic storm present clear seasonal and local time variations under geomagnetic control in a similar way as those of NmF2 (Field and Rishbeth, 1997. A negative phase of TEC occurs with high probability in the summer hemisphere and most prominent near the geomagnetic poles, while a positive phase is obvious in the winter hemisphere and in the far pole region. A negative storm effect toward lower latitudes tends to occur from post-midnight to the morning sector and recedes to high latitude in the afternoon. A positive storm effect is separated by geomagnetic latitudes and magnetic local time. Furthermore, ionospheric responses at different local time sectors with respect to the storm commencement shows very different developing processes corresponding to the evolution of the geomagnetic storm. A daytime positive storm effect is shown to be more prominent in the American region than those in the Asian and European regions, which may suggest a longitudinal effect of the ionospheric storm.

Morphology in the total electron content under geomagnetic disturbed conditions: results from global ionosphere maps

Directory of Open Access Journals (Sweden)

Z. Biqiang

2007-07-01

Full Text Available Using 8-year global ionosphere maps (GIMs of TEC products from the Jet Propulsion Laboratory (JPL, we make a statistical study on the morphology of the global ionospheric behaviors with respect to the geomagnetic disturbances. Results show that the behaviors of TEC during geomagnetic storm present clear seasonal and local time variations under geomagnetic control in a similar way as those of NmF2 (Field and Rishbeth, 1997. A negative phase of TEC occurs with high probability in the summer hemisphere and most prominent near the geomagnetic poles, while a positive phase is obvious in the winter hemisphere and in the far pole region. A negative storm effect toward lower latitudes tends to occur from post-midnight to the morning sector and recedes to high latitude in the afternoon. A positive storm effect is separated by geomagnetic latitudes and magnetic local time. Furthermore, ionospheric responses at different local time sectors with respect to the storm commencement shows very different developing processes corresponding to the evolution of the geomagnetic storm. A daytime positive storm effect is shown to be more prominent in the American region than those in the Asian and European regions, which may suggest a longitudinal effect of the ionospheric storm.

The linguistics of schizophrenia: thought disturbance as language pathology across positive symptoms.

Science.gov (United States)

Hinzen, Wolfram; Rosselló, Joana

2015-01-01

We hypothesize that linguistic (dis-)organization in the schizophrenic brain plays a more central role in the pathogenesis of this disease than commonly supposed. Against the standard view, that schizophrenia is a disturbance of thought or selfhood, we argue that the origins of the relevant forms of thought and selfhood at least partially depend on language. The view that they do not is premised by a theoretical conception of language that we here identify as 'Cartesian' and contrast with a recent 'un-Cartesian' model. This linguistic model empirically argues for both (i) a one-to-one correlation between human-specific thought or meaning and forms of grammatical organization, and (ii) an integrative and co-dependent view of linguistic cognition and its sensory-motor dimensions. Core dimensions of meaning mediated by grammar on this model specifically concern forms of referential and propositional meaning. A breakdown of these is virtually definitional of core symptoms. Within this model the three main positive symptoms of schizophrenia fall into place as failures in language-mediated forms of meaning, manifest either as a disorder of speech perception (Auditory Verbal Hallucinations), abnormal speech production running without feedback control (Formal Thought Disorder), or production of abnormal linguistic content (Delusions). Our hypothesis makes testable predictions for the language profile of schizophrenia across symptoms; it simplifies the cognitive neuropsychology of schizophrenia while not being inconsistent with a pattern of neurocognitive deficits and their correlations with symptoms; and it predicts persistent findings on disturbances of language-related circuitry in the schizophrenic brain.

The linguistics of schizophrenia: thought disturbance as language pathology across positive symptoms

Directory of Open Access Journals (Sweden)

Wolfram eHinzen

2015-07-01

Full Text Available We hypothesize that linguistic (dis- organization in the schizophrenic brain plays a much more central role in the pathogenesis of this disease than commonly supposed. Against the standard view, that schizophrenia is a disturbance of thought or selfhood, we argue that the origins of the relevant forms of thought and selfhood at least partially depend on language. The view that they do not is premised by a theoretical conception of language that we here identify as ‘Cartesian’ and contrast with a recent ‘un-Cartesian’ model. This linguistic model empirically argues for both (i a one-to-one correlation between human-specific thought or meaning and forms of grammatical organization, and (ii an integrative and co-dependent view of linguistic cognition and its sensory-motor dimensions. Core dimensions of meaning mediated by grammar on this model specifically concern forms of referential and propositional meaning. A breakdown of these is virtually definitional of core symptoms. Within this model the three main positive symptoms of schizophrenia fall into place as failures in language-mediated forms of meaning, manifest either as a disorder of speech perception (Auditory Verbal Hallucinations, AVHs, abnormal speech production running without feedback control (Formal Thought Disorder, FTD, or production of abnormal linguistic content (Delusions. Our hypothesis makes testable predictions for the language profile of schizophrenia across symptoms; it simplifies the cognitive neuropsychology of schizophrenia while not being inconsistent with a pattern of neurocognitive deficits and their correlations with symptoms; and it predicts persistent findings on disturbances of language-related circuitry in the schizophrenic brain.

Icariin reverses corticosterone-induced depression-like behavior, decrease in hippocampal brain-derived neurotrophic factor (BDNF) and metabolic network disturbances revealed by NMR-based metabonomics in rats.

Science.gov (United States)

Gong, Meng-Juan; Han, Bin; Wang, Shu-mei; Liang, Sheng-wang; Zou, Zhong-jie

2016-05-10

Previously published reports have revealed the antidepressant-like effects of icariin in a chronic mild stress model of depression and in a social defeat stress model in mice. However, the therapeutic effect of icariin in an animal model of glucocorticoid-induced depression remains unclear. This study aimed to investigate antidepressant-like effect and the possible mechanisms of icariin in a rat model of corticosterone (CORT)-induced depression by using a combination of behavioral and biochemical assessments and NMR-based metabonomics. The depression model was established by subcutaneous injections of CORT for 21 consecutive days in rats, as evidenced by reduced sucrose intake and hippocampal brain-derived neurotrophic factor (BDNF) levels, together with an increase in immobility time in a forced swim test (FST). Icariin significantly increased sucrose intake and hippocampal BDNF level and decreased the immobility time in FST in CORT-induced depressive rats, suggesting its potent antidepressant activity. Moreover, metabonomic analysis identified eight, five and three potential biomarkers associated with depression in serum, urine and brain tissue extract, respectively. These biomarkers are primarily involved in energy metabolism, lipid metabolism, amino acid metabolism and gut microbe metabolism. Icariin reversed the pathological process of CORT-induced depression, partially via regulation of the disturbed metabolic pathways. These results provide important mechanistic insights into the protective effects of icariin against CORT-induced depression and metabolic dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

[Bacterial brain abscess--experiences with 67 patients].

Science.gov (United States)

Berlit, P; Fedel, C; Tornow, K; Schmiedek, P

1996-08-01

Sixty-seven patients with brain abscess were managed over 19 years (1975-1993). Our series had a 2.5 to 1 male predominance; the age distribution was from 3 days to 81 years. The underlying conditions of hematogenic brain abscesses (n = 33; 49%) included lung infections (n = 16), heart disease (n = 4), sepsis (n = 10), and other foci (n = 3). Otolaryngologic infections led to the abscess in 10 cases; there were 9 traumatic abscesses. The causes remained unknown in 15 cases. There were 47 solitary abscesses (70%) and 20 multiple abscesses. The most frequent presenting signs and symptoms were neurologic deficits (n = 17), disturbances of consciousness (n = 14), seizures (n = 6), and headaches, meningism and vomiting (n = 13). Causative organisms were isolated in 39 cases (58%) and included staphylococci (n = 6), streptococci (n = 6), enterobacteriae (n = 2), and anaerobic pathogens (n = 9). The most reliable laboratory sign of inflammation was an elevated ESR (52/59 patients). With the advent of computed tomography, burr hole aspiration of the abscess with or without drainage was possible in 30 cases; the mortality in this subgroup was 9%. All 4 patients with surgical excision in the pre CT-era died. The mortality of patients treated with antibiotics only was 62% (18/29). Overall mortality was 37% (25/67), including 5 cases with post mortem-diagnosis of brain abscess. Good recovery was achieved in 29/42 survivors. Predictors of a poor outcome were the patient's age, the level of consciousness, multiple abscesses, polybacterial cultures, and a hematogenic etiology, but not the size of the abscess.

Coping with continuous human disturbance in the wild: insights from penguin heart rate response to various stressors.

OpenAIRE

Viblanc, V.A.; Smith, A.D.; Gineste, B.; Groscolas, R.

2012-01-01

Abstract Background A central question for ecologists is the extent to which anthropogenic disturbances (e.g. tourism) might impact wildlife and affect the systems under study. From a research perspective, identifying the effects of human disturbance caused by research-related activities is crucial in order to understand and account for potential biases and derive appropriate conclusions from the data. Results Here, we document a case of biological adjustment to chronic human disturbance in a...

Complex network inference from P300 signals: Decoding brain state under visual stimulus for able-bodied and disabled subjects

Science.gov (United States)

Gao, Zhong-Ke; Cai, Qing; Dong, Na; Zhang, Shan-Shan; Bo, Yun; Zhang, Jie

2016-10-01

Distinguishing brain cognitive behavior underlying disabled and able-bodied subjects constitutes a challenging problem of significant importance. Complex network has established itself as a powerful tool for exploring functional brain networks, which sheds light on the inner workings of the human brain. Most existing works in constructing brain network focus on phase-synchronization measures between regional neural activities. In contrast, we propose a novel approach for inferring functional networks from P300 event-related potentials by integrating time and frequency domain information extracted from each channel signal, which we show to be efficient in subsequent pattern recognition. In particular, we construct brain network by regarding each channel signal as a node and determining the edges in terms of correlation of the extracted feature vectors. A six-choice P300 paradigm with six different images is used in testing our new approach, involving one able-bodied subject and three disabled subjects suffering from multiple sclerosis, cerebral palsy, traumatic brain and spinal-cord injury, respectively. We then exploit global efficiency, local efficiency and small-world indices from the derived brain networks to assess the network topological structure associated with different target images. The findings suggest that our method allows identifying brain cognitive behaviors related to visual stimulus between able-bodied and disabled subjects.

Imaging evidence for anatomical disturbances and neuroplastic compensation in persons with Tourette syndrome

DEFF Research Database (Denmark)

Plessen, Kerstin J; Bansal, Ravi; Peterson, Bradley S

2009-01-01

BACKGROUND: Tourette syndrome (TS) is a disorder of chronic motor and vocal tics that begins in childhood. METHODS: A systematic Medline search was conducted to identify existing anatomical imaging studies in persons with TS. RESULTS: Thirty studies were identified, and their methods and findings......, and methods of image analysis, the preponderance of evidence suggests that disturbances in the development of the motor portions of cortical-subcortical circuits likely predispose to the development TS and that neuroplastic changes in control systems of the brain help to modulate the severity of symptom...

Perception of Barriers to the Diagnosis and Receipt of Treatment for Neuropsychiatric Disturbances After Traumatic Brain Injury.

Science.gov (United States)

Albrecht, Jennifer S; O'Hara, Lyndsay M; Moser, Kara A; Mullins, C Daniel; Rao, Vani

2017-12-01

To explore perceptions of barriers and facilitators to the diagnosis and receipt of treatment for neuropsychiatric disturbances (NPDs) after traumatic brain injury (TBI). Qualitative study using semistructured interviews and focus groups. A clinic specializing in the treatment of TBI NPDs, an urban trauma center, and a large urban academic hospital. A sample (N=33) of health care providers (n=10) who treat individuals with TBI, persons with TBI (n=18), and caregivers (n=5). Not applicable. Topic guides for the interviews and focus groups were guided by previous literature, clinical experience, and the goals of the project and focused on the 3 most common TBI NPDs: depression, anxiety, and posttraumatic stress disorder. The interviews and focus groups were audio-recorded and transcribed verbatim. We performed a conventional content analysis on the transcripts and grouped concepts into overall themes, incorporating feedback from stakeholders. Patient education, insurance, provider type, time since TBI, caregiver support, and recognition or screening for TBI NPDs were the most frequently mentioned barriers or facilitators to the diagnosis and treatment of TBI NPDs by both interview and focus group participants. We grouped these and other frequently mentioned concepts into 3 broad themes: education, access, and support. Each of these themes is explored in depth and supported with direct quotations. This study explored patient, caregiver, and health care provider and identified barriers and facilitators to the diagnosis and receipt of treatment for TBI NPDs. Barriers included poor provider education on TBI NPDs and limited access to care due to lack of insurance, transportation, and income. Facilitators included patient education on TBI NPDs and strong caregiver support. Future studies should develop and pilot interventions aimed at quality of care that address the identified barriers and facilitators. Copyright © 2017 American Congress of Rehabilitation Medicine

Astrocyte–endothelial interactions and blood–brain barrier permeability*

Science.gov (United States)

Abbott, N Joan

2002-01-01

The blood–brain barrier (BBB) is formed by brain endothelial cells lining the cerebral microvasculature, and is an important mechanism for protecting the brain from fluctuations in plasma composition, and from circulating agents such as neurotransmitters and xenobiotics capable of disturbing neural function. The barrier also plays an important role in the homeostatic regulation of the brain microenvironment necessary for the stable and co-ordinated activity of neurones. The BBB phenotype develops under the influence of associated brain cells, especially astrocytic glia, and consists of more complex tight junctions than in other capillary endothelia, and a number of specific transport and enzyme systems which regulate molecular traffic across the endothelial cells. Transporters characteristic of the BBB phenotype include both uptake mechanisms (e.g. GLUT-1 glucose carrier, L1 amino acid transporter) and efflux transporters (e.g. P-glycoprotein). In addition to a role in long-term barrier induction and maintenance, astrocytes and other cells can release chemical factors that modulate endothelial permeability over a time-scale of seconds to minutes. Cell culture models, both primary and cell lines, have been used to investigate aspects of barrier induction and modulation. Conditioned medium taken from growing glial cells can reproduce some of the inductive effects, evidence for involvement of diffusible factors. However, for some features of endothelial differentiation and induction, the extracellular matrix plays an important role. Several candidate molecules have been identified, capable of mimicking aspects of glial-mediated barrier induction of brain endothelium; these include TGFβ, GDNF, bFGF, IL-6 and steroids. In addition, factors secreted by brain endothelial cells including leukaemia inhibitory factor (LIF) have been shown to induce astrocytic differentiation. Thus endothelium and astrocytes are involved in two-way induction. Short-term modulation of brain

Predictability of prototype flash flood events in the Western Mediterranean under uncertainties of the precursor upper-level disturbance: the HYDROPTIMET case studies

Directory of Open Access Journals (Sweden)

R. Romero

2005-01-01

uncertainty in the representation of the upper-level disturbance and the necessity to cope with it within the operational context when attempting to issue short to mid-range numerical weather predictions of these high impact weather events, a systematic exploration of the predictability of the three selected case studies subject to uncertainties in the representation of the upper-level precursor disturbance is carried out in this paper. The study is based on an ensemble of mesoscale numerical simulations of each event with the MM5 non-hydrostatic model after perturbing in a systematic way the upper-level disturbance, in the sense of displacing slightly this disturbance upstream/downstream along the zonal direction and intensifying/weakening its amplitude. These perturbations are guided by a previous application of the MM5-adjoint model, which consistently shows high sensitivities of the dynamical control of the heavy rain to the flow configuration about the upper-level disturbance on the day before, thus confirming the precursor characteristics of this agent. The perturbations are introduced to the initial conditions by applying a potential vorticity (PV inversion procedure to the positive PV anomaly associated with the upper-level disturbance, and then using the inverted fields (wind, temperature and geopotential to modify under a physically consistent balance the model initial fields. The results generally show that the events dominated by mesoscale low-level disturbances (Catalogne and last stage of the Piémont episode are very sensitive to the initial uncertainties, such that the heavy rain location and magnitude are in some of the experiments strongly changed in response to the 'forecast errors' of the cyclone trajectory, intensity, shape and translational speed. In contrast, the other situations (Cévennes and initial stage of the Piémont episode, dominated by a larger scale system wich basically acts to guarantee the establishment and persistence of the southerly LLJ

Globally Efficient Brain Organization and Treatment Response in Psychosis: A Connectomic Study of Gyrification

OpenAIRE

Palaniyappan, Lena; Marques, Tiago Reis; Taylor, Heather; Mondelli, Valeria; Reinders, A. A. T. Simone; Bonaccorso, Stefania; Giordano, Annalisa; DiForti, Marta; Simmons, Andrew; David, Anthony S.; Pariante, Carmine M.; Murray, Robin M.; Dazzan, Paola

2016-01-01

Background: Converging evidence suggests that patients with first-episode psychosis who show a poor treatment response may have a higher degree of neurodevelopmental abnormalities than good Responders. Characterizing the disturbances in the relationship among brain regions (covariance) can provide more information on neurodevelopmental integrity than searching for localized changes in the brain. Graph-based connectomic approach can measure structural covariance thus providing information on t...

Disturbance Decoupling of Switched Linear Systems

NARCIS (Netherlands)

Yurtseven, E.; Heemels, W.P.M.H.; Camlibel, M.K.

2010-01-01

In this paper we consider disturbance decoupling problems for switched linear systems. We will provide necessary and sufficient conditions for three different versions of disturbance decoupling, which differ based on which signals are considered to be the disturbance. In the first version the

The Presenting Feature and Role of General Practitioners and Non-neurosurgeon Physicians in Recognizing Pediatric Brain Tumors

Directory of Open Access Journals (Sweden)

Wihasto Suryaningtyas

2010-04-01

Full Text Available AIM: To determine the presenting features and role of non-neurosurgeon physician in recognizing the signs and symptoms of brain tumours in children. METHOD: Medical records of 31 pediatric brain tumor patients treated in Department of Neurosurgery, Soetomo General Hospital, Airlangga University Faculty of Medicine, Surabaya from August 2005 to September 2006 were reviewed. RESULTS: Thirty five percents f parents went to pediatrician as their first contact physician, 25% to general practitioner, 20% neurologist, 20% to neurosurgeon. Neurosurgeon was the second and third contact physician receiving refferal from non-neurosurgeon physician. The most common symptoms were headache (71%, vomiting (61%, motor weakness (48%, visual disturbance (45%, decrease level of consciousness (45% and seizures (38%, unsteadiness (35%. The most common symptoms that led the parents to find medical help at any time were motor disturbance (48%, vomiting (48%, visual disturbance (45%, unsteadiness (35%, decrease level of consciousness (32%, seizures (32%, headache (32%. All patients had neurological signs at diagnosis; 58% had papilloedema, 48% cranial nerve abnormalities, 35% cerebellar signs, 32% motor disturbance, 29% a reduced level of consciousness, 12% cranial enlargement. Duration of symptoms at admission was 1 months (32%, 2 months (42%, 3-6 months (19%, more than 6 months (7%. A short symptom interval was significantly associated with high grade tumours and patient age 3 years or younger. CONCLUSION: The symptoms and signs are often nonspecific, mimicking more common diseases. Therefore, the possibility of a brain neoplasm should always be considered, it materializes very rarely. Benign neurologic symptoms such as headache, which last for 2 months or more, should indicate the need of additional studies. Our results higlighted the neurologic impairments which might facilitate early recognition of a brain neoplasm. Neurologic problems as the only symptom of brain

Disturbance analysis in nuclear power plants

International Nuclear Information System (INIS)

Sillamaa, M.A.

Disturbance analysis is any systematic procedure that helps an operator determine what has failed. This paper describes the typical information currently provided in CANDU power plants to help the operator respond to a disturbance. It presents a simplified model of how an operator could get into trouble, and briefly reviews development work on computerized disturbance analysis systems for nuclear power plants being done in various countries including Canada. Disturbance analysis systems promise to be useful tools in helping operators improve their response to complex situations. However, the originality and complexity of the work for a disturbance analysis system and the need to develop operator confidence and management support require a 'walk before you run' approach

[Taste disturbance after general anesthesia with classic laryngeal mask airway (CLM)].

Science.gov (United States)

Arimune, Mutsuaki

2007-07-01

A 27-year-old man underwent the right knee joint operation under general anesthesia with CLM. After the operation, he complained of taste disturbance of the left side of the tongue. We measured electrical taste threshold and the serum level of zinc, copper and iron. The taste threshold was elevated in the two nerve areas of the left side of the tongue (chorda tympani, N. glossopharyngeus) and the serum levels of zinc and iron were low. We concluded that he had been short of zinc and iron and the insertion of CLM had triggered taste disturbance.

The Development of Neuroendocrine Disturbances over Time: Longitudinal Findings in Patients after Traumatic Brain Injury and Subarachnoid Hemorrhage

Directory of Open Access Journals (Sweden)

Anna Kopczak

2015-12-01

Full Text Available Previous reports suggest that neuroendocrine disturbances in patients with traumatic brain injury (TBI or aneurysmal subarachnoid hemorrhage (SAH may still develop or resolve months or even years after the trauma. We investigated a cohort of n = 168 patients (81 patients after TBI and 87 patients after SAH in whom hormone levels had been determined at various time points to assess the course and pattern of hormonal insufficiencies. Data were analyzed using three different criteria: (1 patients with lowered basal laboratory values; (2 patients with lowered basal laboratory values or the need for hormone replacement therapy; (3 diagnosis of the treating physician. The first hormonal assessment after a median time of three months after the injury showed lowered hormone laboratory test results in 35% of cases. Lowered testosterone (23.1% of male patients, lowered estradiol (14.3% of female patients and lowered insulin-like growth factor I (IGF-I values (12.1% were most common. Using Criterion 2, a higher prevalence rate of 55.6% of cases was determined, which correlated well with the prevalence rate of 54% of cases using the physicians’ diagnosis as the criterion. Intraindividual changes (new onset insufficiency or recovery were predominantly observed for the somatotropic axis (12.5%, the gonadotropic axis in women (11.1% and the corticotropic axis (10.6%. Patients after TBI showed more often lowered IGF-I values at first testing, but normal values at follow-up (p < 0.0004. In general, most patients remained stable. Stable hormone results at follow-up were obtained in 78% (free thyroxine (fT4 values to 94.6% (prolactin values.

Brain Responses Underlying Anthropomorphism, Agency, and Social Attribution in Autism Spectrum Disorder.

Science.gov (United States)

Ammons, Carla J; Doss, Constance F; Bala, David; Kana, Rajesh K

2018-01-01

Theory of Mind (ToM), the ability to attribute mental states to oneself and others, is frequently impaired in Autism Spectrum Disorder (ASD) and may result from altered activation of social brain regions. Conversely, Typically Developing (TD) individuals overextend ToM and show a strong tendency to anthropomorphize and interpret biological motion in the environment. Less is known about how the degree of anthropomorphism influences intentional attribution and engagement of the social brain in ASD. This fMRI study examines the extent of anthropomorphism, its role in social attribution, and the underlying neural responses in ASD and TD using a series of human stick figures and geometrical shapes. 14 ASD and 14 TD adults watched videos of stick figures and triangles interacting in random or socially meaningful ways while in an fMRI scanner. In addition, they completed out-of-scanner measures of ToM skill and real-world social deficits. Whole brain statistical analysis was performed for regression and within and between group comparisons of all conditions using SPM12's implementation of the general linear model. ToM network regions were activated in response to social movement and human-like characters in ASD and TD. In addition, greater ToM ability was associated with increased TPJ and MPFC activity while watching stick figures; whereas more severe social symptoms were associated with reduced right TPJ activation in response to social movement. These results suggest that degree of anthropomorphism does not differentially affect social attribution in ASD and highlights the importance of TPJ in ToM and social attribution.

The Disturbing Student and the Judicial Process

Science.gov (United States)

Ragle, John D.; Paine, Gage E.

2009-01-01

The Assessment-Intervention of Student Problems (AISP) model is a useful tool for preparing student affairs professionals to assess the problems of disturbed, disturbing, or disturbed/disturbing students and to make appropriate referrals. It is particularly useful because it emphasizes the necessity of developing an integrated system for this…

Variants of early-onset restrictive eating disturbances in middle childhood.

Science.gov (United States)

Kurz, Susanne; van Dyck, Zoé; Dremmel, Daniela; Munsch, Simone; Hilbert, Anja

2016-01-01

This study sought to determine the factor structure of the newly developed self-report screening questionnaire Eating Disturbances in Youth-Questionnaire (EDY-Q) as well as to report the distribution of variants of early-onset restrictive eating disturbances characteristic of avoidant/restrictive food intake disorder (ARFID) in a middle childhood population sample. Using the EDY-Q, a total of 1,444 children aged 8-13 years were screened in elementary schools in Switzerland via self-report. The factor analysis of the 12 items covering ARFID related symptoms was performed using a principal component analysis (PCA). The PCA showed a four factor solution, with clear allocation to the scales covering three variants of early-onset restrictive eating disturbances and weight problems. Inadequate overall food intake was reported by 19.3% of the children, a limited accepted amount of food by 26.1%, and food avoidance based on a specific underlying fear by 5.0%. The postulated factor structure of the EDY-Q was confirmed, further supporting the existence of distinct variants of early-onset restrictive eating disturbances. Avoidant/restrictive eating behavior seems to be a common experience in middle childhood, but results have to be confirmed using validated interviews. © 2015 Wiley Periodicals, Inc.

Impact of global warming on cyclonic disturbances over south Asian ...

Indian Academy of Sciences (India)

The model simulations under the scenarios of increasing greenhouse gas concentrations and sulphate aerosols are analysed to study the likely changes in the frequency, intensity and the tracks of cyclonic disturbances forming over north Indian Ocean (Bay of Bengal and Arabian Sea) and the Indian landmass during ...

Involvement of Neuroinflammation during Brain Development in Social Cognitive Deficits in Autism Spectrum Disorder and Schizophrenia.

Science.gov (United States)

Nakagawa, Yutaka; Chiba, Kenji

2016-09-01

Development of social cognition, a unique and high-order function, depends on brain maturation from childhood to adulthood in humans. Autism spectrum disorder (ASD) and schizophrenia have similar social cognitive deficits, although age of onset in each disorder is different. Pathogenesis of these disorders is complex and contains several features, including genetic risk factors, environmental risk factors, and sites of abnormalities in the brain. Although several hypotheses have been postulated, they seem to be insufficient to explain how brain alterations associated with symptoms in these disorders develop at distinct developmental stages. Development of ASD appears to be related to cerebellar dysfunction and subsequent thalamic hyperactivation in early childhood. By contrast, schizophrenia seems to be triggered by thalamic hyperactivation in late adolescence, whereas hippocampal aberration has been possibly initiated in childhood. One of the possible culprits is metal homeostasis disturbances that can induce dysfunction of blood-cerebrospinal fluid barrier. Thalamic hyperactivation is thought to be induced by microglia-mediated neuroinflammation and abnormalities of intracerebral environment. Consequently, it is likely that the thalamic hyperactivation triggers dysregulation of the dorsolateral prefrontal cortex for lower brain regions related to social cognition. In this review, we summarize the brain aberration in ASD and schizophrenia and provide a possible mechanism underlying social cognitive deficits in these disorders based on their distinct ages of onset. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

[STUDYING THE ROLE OF BRAIN MELANOCORTIN RECEPTORS IN THE SUPPRESSING OF FOOD INTAKE UNDER ETHER STRESS IN MICE].

Science.gov (United States)

Bazhan, N M; Kulikova, E V; Makarova, E N; Yakovleva, T V; Kazantseva, A Yu

2015-12-01

Melanocortin (MC) system regulates food intake under the rest conditions. Stress inhibits food intake. It is not clear whether brain MC system is involved in stress-induced anorexia in mice. The aim of the work was to investigate the effect of pharmacological blockade and activation of brain MC receptors on food intake under stress. C57B1/6J male mice were subjected to ether stress (0.5 minute ether anesthesia) before the administration of saline solution or synthetic non-selective blocker (SHU9119) or agonist (Melanotan II) of MC receptors into the lateral brain ventricle. Food intake was pre-stimulated with 17 hours of fasting in all mice. Ether stress decreased food intake, increased the plasma corticosterone level and hypothalamic mRNA AgRP (natural MC receptor antagonist) level at 1 hour after the stress. Pharmacological blockade of the MC receptors weakened stress-induced anorexia and decreased mRNA AgRP level in the hypothalamus. Pharmacological stimulation of the MC receptors enhanced ether stress-induced anorexia and hypercortisolism. Thus, our data demonstrated that the central MC system was involved in the development of stress-induced anorexia in mice.

Diagnostic work up for language testing in patients undergoing awake craniotomy for brain lesions in language areas.

Science.gov (United States)

Bilotta, Federico; Stazi, Elisabetta; Titi, Luca; Lalli, Diana; Delfini, Roberto; Santoro, Antonio; Rosa, Giovanni

2014-06-01

Awake craniotomy is the technique of choice in patients with brain tumours adjacent to primary and accessory language areas (Broca's and Wernicke's areas). Language testing should be aimed to detect preoperative deficits, to promptly identify the occurrence of new intraoperative impairments and to establish the course of postoperative language status. Aim of this case series is to describe our experience with a dedicated language testing work up to evaluate patients with or at risk for language disturbances undergoing awake craniotomy for brain tumour resection. Pre- and intra operative testing was accomplished with 8 tests. Intraoperative evaluation was accomplished when patients were fully cooperative (Ramsey awake craniotomy for brain tumour resection with preoperative language disturbances or at risk for postoperative language deficits. This approach allows a systematic evaluation and recording of language function status and can be accomplished even when a neuropsychologist or speech therapist are not involved in the operation crew.

Clinical evaluation of dose-volume-effect relationship in radiation injury of the brain

International Nuclear Information System (INIS)

Saito, Mari

1990-01-01

Radiation brain injury, including functional disturbances or morphological changes (brain atrophy, periventricular lucencies or ventricular dilatation), were studied by CT in patients with primary intracranial neoplasms who were followed-up for at least 5 months after receiving radiotherapy. Each of 33 patients with medulloblastoma, pinealregion tumor or malignant lymphoma received a total dose of 40-61 Gy by conventional fractionation using a whole brain irradiation field boosted by a localized field. Of these patients, 19 (58%) developed radiation brain injury. It was concluded that the volume-dose was one of the most important factors influencing the development of radiation brain injury. Age at the time of radiotherapy and time of follow-up after the treatment were also considered to be important factors. (author)

Impacts and underlying factors of landscape-scale, historical disturbance of mountain forest identified using archival documents

Czech Academy of Sciences Publication Activity Database

Brůna, Josef; Wild, Jan; Svoboda, M.; Heurich, M.; Müllerová, Jana

2013-01-01

Roč. 2013, č. 305 (2013), s. 294-306 ISSN 0378-1127 R&D Projects: GA ČR GAP504/10/0843 Institutional support: RVO:67985939 Keywords : mountain forests * disturbance * historical range of variability Subject RIV: EF - Botanics Impact factor: 2.667, year: 2013

Copper exposure induces oxidative injury, disturbs the antioxidant system and changes the Nrf2/ARE (CuZnSOD) signaling in the fish brain: Protective effects of myo-inositol

Energy Technology Data Exchange (ETDEWEB)

Jiang, Wei-Dan; Liu, Yang [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Hu, Kai [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Jiang, Jun [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Li, Shu-Hong [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Feng, Lin, E-mail: fenglin@sicau.edu.cn [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Zhou, Xiao-Qiu, E-mail: xqzhouqq@tom.com [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China)

2014-10-15

Highlights: • Cu exposure increased ROS production, lipid and protein oxidation of fish brain. • Cu exposure caused depletion of some antioxidants in the brain of fish. • Cu exposure up-regulated mRNA levels of brain CuZnSOD, GPx1a and GR genes in fish. • Cu exposure induced Nrf2 nuclear translocation and binding to ARE in fish brain. • Myo-inositol can inhibit Cu-induced toxic effects in the brain of fish. - Abstract: The brain is the center of the nervous system in all vertebrates, and homeostasis of the brain is crucial for fish survival. Copper (Cu) is essential for normal cellular processes in most eukaryotic organisms but is toxic in excess. Although Cu is indicated as a potent neurotoxicant, information regarding its threat to fish brain and underlying mechanisms is still scarce. In accordance, the objective of this study was to assess the effects and the potential mechanism of Cu toxicity by evaluating brain oxidative status, the enzymatic and mRNA levels of antioxidant genes, as well as the Nrf2/ARE signaling in the brain of fish after Cu exposure. The protective effects of myo-inositol (MI) against subsequent Cu exposure were also investigated. The results indicate that induction of oxidative stress by Cu is shown by increases in brain ROS production, lipid peroxidation and protein oxidation, which are accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), CuZnSOD, glutathione-S-transferase (GST) and glutathione reductase (GR) activities and glutathione (GSH) content. Cu exposure increased the catalase (CAT) and glutathione peroxidase (GPx) activities. Further molecular results showed that Cu exposure up-regulated CuZnSOD, GPx1a and GR mRNA levels, suggesting an adaptive mechanism against stress. Moreover, Cu exposure increased fish brain Nrf2 nuclear accumulation and increased its ability of binding to ARE (CuZnSOD), which supported the increased CuZnSOD mRNA levels. In addition, Cu exposure caused increases of

Copper exposure induces oxidative injury, disturbs the antioxidant system and changes the Nrf2/ARE (CuZnSOD) signaling in the fish brain: Protective effects of myo-inositol

International Nuclear Information System (INIS)

Jiang, Wei-Dan; Liu, Yang; Hu, Kai; Jiang, Jun; Li, Shu-Hong; Feng, Lin; Zhou, Xiao-Qiu

2014-01-01

Highlights: • Cu exposure increased ROS production, lipid and protein oxidation of fish brain. • Cu exposure caused depletion of some antioxidants in the brain of fish. • Cu exposure up-regulated mRNA levels of brain CuZnSOD, GPx1a and GR genes in fish. • Cu exposure induced Nrf2 nuclear translocation and binding to ARE in fish brain. • Myo-inositol can inhibit Cu-induced toxic effects in the brain of fish. - Abstract: The brain is the center of the nervous system in all vertebrates, and homeostasis of the brain is crucial for fish survival. Copper (Cu) is essential for normal cellular processes in most eukaryotic organisms but is toxic in excess. Although Cu is indicated as a potent neurotoxicant, information regarding its threat to fish brain and underlying mechanisms is still scarce. In accordance, the objective of this study was to assess the effects and the potential mechanism of Cu toxicity by evaluating brain oxidative status, the enzymatic and mRNA levels of antioxidant genes, as well as the Nrf2/ARE signaling in the brain of fish after Cu exposure. The protective effects of myo-inositol (MI) against subsequent Cu exposure were also investigated. The results indicate that induction of oxidative stress by Cu is shown by increases in brain ROS production, lipid peroxidation and protein oxidation, which are accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), CuZnSOD, glutathione-S-transferase (GST) and glutathione reductase (GR) activities and glutathione (GSH) content. Cu exposure increased the catalase (CAT) and glutathione peroxidase (GPx) activities. Further molecular results showed that Cu exposure up-regulated CuZnSOD, GPx1a and GR mRNA levels, suggesting an adaptive mechanism against stress. Moreover, Cu exposure increased fish brain Nrf2 nuclear accumulation and increased its ability of binding to ARE (CuZnSOD), which supported the increased CuZnSOD mRNA levels. In addition, Cu exposure caused increases of

A case of leukoencephalopathy caused by radiation and chemotherapy for brain metastasis of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Shigeru; Sonoo, Hiroshi; Nomura, Tsunehisa; Ohkubo, Sumiko; Yamamoto, Yutaka; Tanaka, Katsuhiro; Kurebayashi, Junichi; Hiratsuka, Junichi [Kawasaki Medical School, Kurashiki, Okayama (Japan)

2002-08-01

A case of treatment-related leukoencephalopathy is presented. A patient with breast cancer metastasis to the brain, liver, bone and distant lymph nodes was treated with whole brain radiation and docetaxcel. Eleven months after radiation, magnetic resonance imaging showed diffuse leukoencephalopathy. Twenty-two months after radiation, the patient had gait disturbance, parkinsonism, dementia and urinary incontinence. From this experience, stereotactic radiosurgery such as cyber knife and gamma knife therapy, representing a new modality for delivering intense focal radiation, should be come preferred techniques for treating patients with brain metastases, to avoid the potential cognitive side effects of fractionated whole-brain radiotherapy. (author)

Integrating Landsat-derived disturbance maps with FIA inventory data: Applications for state-Level forest resource assessments

Science.gov (United States)

Sonja Oswalt; Chengquan Huang; Hua Shi; James Vogelmann; Zhiliang Zhu; Samuel N. Goward; John Coulston

2009-01-01

Landsat images have been widely used for assessing forest characteristics and dynamics. Recently, significant progress has been made towards indepth exploration of the rich Landsat archive kept by the U.S. Geological Survey to improve our under standing of forest disturbance and recovery processes. In this study, we used Landsat images to map forest disturbances at...

Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica ? A Pilot Study

OpenAIRE

Doring, Thomas Martin; Granado, Vanessa; Rueda, Fernanda; Deistung, Andreas; Reichenbach, Juergen R.; Tukamoto, Gustavo; Gasparetto, Emerson Leandro; Schweser, Ferdinand

2016-01-01

Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO) using quantitative susceptibility mapping (QSM), a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y) and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y) underwen...

Prenatal irradiation and developmental disorders of the brain

International Nuclear Information System (INIS)

Kameyama, Yoshiro

1987-01-01

The radiation sensitivity of the brain of a growing fetus is higher than that of other organs and tissues. Of the various organs in the human body, the brain has the most complicated structure. The major features of developmental disorders of the brain, which are produced rather easily by external causes, are: (a) the sensitive period for developmental disorders is long, (b) undifferentiated nerve cells are sensitive to external causes and (c) such disorders leads to irreversible functional failures after birth. The malformation of the brain and its relations with the sensitivity are briefly described. Experiments with prenatal animals have shown that major developmental disorders of brain tissue include death of undifferentiated cells, lack of constituent neurons and disturbance in structure of the cortex, and that typical developmental abnormalities include dysgenetic hydrocephaly, microcephalia, etc. Teratological features of histogenetic disorders of the brain are then briefly outlined. Various experimental results on these and other disorders caused by radiations are presented and discussed. Data on fetuses exposed to radiations at Hiroshima and Nagasaki are also given and discussed. The last section of the report deals with risk evaluation. (Nogami, K.)

Neuroimaging of post-traumatic higher brain dysfunction using 123I-Iomazenil (IMZ) SPECT

International Nuclear Information System (INIS)

Nakagawara, Jyoji; Kamiyama, Kenji; Takahashi, Masaaki; Nakamura, Hirohiko

2010-01-01

In patients with mild traumatic brain injury (MTBI), higher brain dysfunctions which consist of cognitive impairments such as memory, attention, performance and social behavioral disturbances could be rarely apparent. However, higher brain dysfunctions should be identified by neuropsychological tests and supported by a social welfare for handicapped patients. Acknowledgement of higher brain dysfunctions after MTBI without obvious brain damages on morphological neuroimagings could be a social issue under controversy. An imaging of cortical neuron damages in patients with higher brain dysfunctions after MTBI was studied by functional neuroimaging using 123 I-Iomazenil (IMZ) single photon emission computed tomography (SPECT). Statistical imaging analyses using 3 dimensional stereotactic surface projections (3D-SSP) for 123 I-IMZ SPECT and 123 I-IMP SPECT as cerebral blood flow (CBF) studies were performed in 11 patients with higher brain dysfunctions after MTBI. In all patients with higher brain dysfunctions defined by neuropsychological tests, cortical neuron damages were observed in bilateral medial frontal lobes, but reduction of CBF in bilateral medial frontal lobes were less obviously showed in 8 patients (apparent in 3 and little in 5). Group comparison of 3D-SSP of 123 I-IMZ SPECT between 11 patients and 18 normal controls demonstrated significant selective loss of cortical neuron in bilateral medial frontal gyrus (MFG). Extent of abnormal pixels on each cortical gyrus using stereotactic extraction estimation (SEE) for 3D-SSP of 123 I-IMZ SPECT confirmed that 8 patients had abnormal pixel extent >10% in bilateral MFG and 5 patients had abnormal pixel extent >10% in bilateral anterior cingulate gyrus. In patients with MTBI, higher brain dysfunctions seems to correlate with selective loss of cortical neuron within bilateral MFG which could be caused by Wallerian degeneration as secondary phenomena after diffuse axonal injury within corpus callosum. Statistical

Identification of Individuals with Serious Emotional Disturbance Using the Draw a Person: Screening Procedure for Emotional Disturbance.

Science.gov (United States)

McNeish, Timothy J.; Naglieri, Jack A.

1993-01-01

Regular education students (n=81) and students with serious emotional disturbance (n=81,) were matched on age (7-13), gender, race, and intelligence. They completed drawings which were scored using the "Draw a Person: Screening Procedure for Emotional Disturbance." Students with emotional disturbance scored significantly higher than did…

Too big or too narrow? Disturbance characteristics determine the functional resilience in virtual microbial ecosystems

Science.gov (United States)

König, Sara; Firle, Anouk-Letizia; Koehnke, Merlin; Banitz, Thomas; Frank, Karin

2017-04-01

dramatically. Under recurrent disturbance events, this threshold is shifted to lower disturbance sizes. The more frequent disturbances are recurring, the lower is the critical disturbance size. Our simulation results indicate the importance of spatial characteristics of disturbance events for the functional resilience of microbial ecosystems. Critical values for disturbance size and fragmentation emerge from an interplay between both characteristics. In consequence, a precise definition of the specific disturbance regime is necessary for analysing functional resilience. With this study, we show that we need to consider the influence of fragmentation in terrestrial environments not only on population extincions but also on the resilience of ecosystem functions. Moreover, spatial disturbance characteristics - which are widely discussed on landscape scale - are an important factor on smaller scales, too.

Sleep disturbances in Parkinsonism.

Science.gov (United States)

Askenasy, J J M

2003-02-01

The present article is meant to suggest an approach to the guidelines for the therapy of sleep disturbances in Parkinson's Disease (PD) patients.The factors affecting the quality of life in PD patients are depression, sleep disturbances and dependence. A large review of the literature on sleep disturbances in PD patients, provided the basis for the following classification of the sleep-arousal disturbances in PD patients. We suggest a model based on 3 steps in the treatment of sleep disturbances in PD patients. This model allowing the patient, the spouse or the caregiver a quiet sleep at night, may postpone the retirement and the institutionalization of the PD patient. I. Correct diagnosis of sleep disorders based on detailed anamnesis of the patient and of the spouse or of the caregiver. One week recording on a symptom diary (log) by the patient or the caregiver. Correct diagnosis of sleep disorders co morbidities. Selection of the most appropriate sleep test among: polysomnography (PSG), multiple sleep latency test (MSLT), multiple wake latency test (MWLT), Epworth Sleepiness Scale, actigraphy or video-PSG. II. The nonspecific therapeutic approach consists in: a) Checking the sleep effect on motor performance, is it beneficial, worse or neutral. b) Psycho-physical assistance. c) Dopaminergic adjustment is necessary owing to the progression of the nigrostriatal degeneration and the increased sensitivity of the terminals, which alter the normal modulator mechanisms of the motor centers in PD patients. Among the many neurotransmitters of the nigro-striatal pathway one can distinguish two with a major influence on REM and NonREM sleep. REM sleep corresponds to an increased cholinergic receptor activity and a decreased dopaminergic activity. This is the reason why REM sleep deprivation by suppressing cholinergic receptor activity ameliorates PD motor symptoms. L-Dopa and its agonists by suppressing cholinergic receptors suppress REM sleep. The permanent adjustment

The in vitro blood-brain barrier model under OGD condition

DEFF Research Database (Denmark)

Tornabene, Erica; Helms, Hans Christian Cederberg; Berndt, Philipp

Introduction - The blood-brain barrier (BBB) is a physical, transport and metabolic barrier which plays a key role in preventing uncontrolled exchanges between blood and brain, ensuring an optimal environment for neurons activity. This extent interface is created by the endothelial cells forming...... the wall of brain capillaries. The restrictive nature of the BBB is due to the presence of tight junctions, which seal the paracellular space, a low number of endocytotic vesicles and the presence of efflux transporters, resulting in a very tight layer. Ischemic insult and the subsequent reperfusion...... of therapies to treat this devastating disease. Materials and Methods - Primary cultures of endothelial cells from bovine brain microvessels were cocultured with rat astrocytes in transwell inserts. At day 11, cells were treated with 4h of OGD by changing the culture medium with glucose-free medium...

Insulin-Resistant Brain State: the culprit in sporadic Alzheimer’s Disease?

Science.gov (United States)

Correia, Sónia C.; Santos, Renato X.; Perry, George; Zhu, Xiongwei; Moreira, Paula I.; Smith, Mark A.

2011-01-01

Severe abnormalities in brain glucose/energy metabolism and insulin signaling have been documented to take a pivotal role in early sporadic Alzheimer’s disease (sAD) pathology. Indeed, the “insulin-resistant brain state” has been hypothesized to form the core of the neurodegenerative events that occur in sAD. In this vein, intracerebroventricular administration of subdiabetogenic doses of streptozotocin (STZ) in rats can induce an insulin-resistant brain state, which is proposed as a suitable experimental model of sAD. This review highlights the involvement of disturbed brain insulin metabolism in sAD etiopathogenesis. Furthermore, current knowledge demonstrates that central STZ administration produces brain pathology and behavioral changes that resemble changes found in sAD patients. The STZ-intracerebroventricularly treated rat represents a promising experimental tool in this field by providing new insights concerning early brain alterations in sAD, which can be translated in novel etiopathogenic and therapeutic approaches in this disease. PMID:21262392

Clear signals or mixed messages: inter-individual emotion congruency modulates brain activity underlying affective body perception

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de Gelder, B.

2016-01-01

The neural basis of emotion perception has mostly been investigated with single face or body stimuli. However, in daily life one may also encounter affective expressions by groups, e.g. an angry mob or an exhilarated concert crowd. In what way is brain activity modulated when several individuals express similar rather than different emotions? We investigated this question using an experimental design in which we presented two stimuli simultaneously, with same or different emotional expressions. We hypothesized that, in the case of two same-emotion stimuli, brain activity would be enhanced, while in the case of two different emotions, one emotion would interfere with the effect of the other. The results showed that the simultaneous perception of different affective body expressions leads to a deactivation of the amygdala and a reduction of cortical activity. It was revealed that the processing of fearful bodies, compared with different-emotion bodies, relied more strongly on saliency and action triggering regions in inferior parietal lobe and insula, while happy bodies drove the occipito-temporal cortex more strongly. We showed that this design could be used to uncover important differences between brain networks underlying fearful and happy emotions. The enhancement of brain activity for unambiguous affective signals expressed by several people simultaneously supports adaptive behaviour in critical situations. PMID:27025242

Long-term disturbance dynamics and resilience of tropical peat swamp forests.

Science.gov (United States)

Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

2015-01-01

1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c . 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c . 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c . 500 years ago, these communities started to decline. 5. Synthesis . Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude

Optimism and the brain: trait optimism mediates the protective role of the orbitofrontal cortex gray matter volume against anxiety.

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Dolcos, Sanda; Hu, Yifan; Iordan, Alexandru D; Moore, Matthew; Dolcos, Florin

2016-02-01

Converging evidence identifies trait optimism and the orbitofrontal cortex (OFC) as personality and brain factors influencing anxiety, but the nature of their relationships remains unclear. Here, the mechanisms underlying the protective role of trait optimism and of increased OFC volume against symptoms of anxiety were investigated in 61 healthy subjects, who completed measures of trait optimism and anxiety, and underwent structural scanning using magnetic resonance imaging. First, the OFC gray matter volume (GMV) was associated with increased optimism, which in turn was associated with reduced anxiety. Second, trait optimism mediated the relation between the left OFC volume and anxiety, thus demonstrating that increased GMV in this brain region protects against symptoms of anxiety through increased optimism. These results provide novel evidence about the brain-personality mechanisms protecting against anxiety symptoms in healthy functioning, and identify potential targets for preventive and therapeutic interventions aimed at reducing susceptibility and increasing resilience against emotional disturbances. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Latitudinal profile of the ionospheric disturbance dynamo magnetic signature: comparison with the DP2 magnetic disturbance

Directory of Open Access Journals (Sweden)

K. Z. Zaka

2009-09-01

Full Text Available During magnetic storms, the auroral electrojets intensification affects the thermospheric circulation on a global scale. This process which leads to electric field and current disturbance at middle and low latitudes, on the quiet day after the end of a storm, has been attributed to the ionospheric disturbance dynamo (Ddyn. The magnetic field disturbance observed as a result of this process is the reduction of the H component amplitude in the equatorial region which constitutes the main characteristic of the ionospheric disturbance dynamo process, associated with a westward electric current flow. The latitudinal profile of the Ddyn disturbance dynamo magnetic signature exhibits an eastward current at mid latitudes and a westward one at low latitudes with a substantial amplification at the magnetic equator. Such current flow reveals an "anti-Sq" system established between the mid latitudes and the equatorial region and opposes the normal Sq current vortex. However, the localization of the eastward current and consequently the position and the extent of the "anti-Sq" current vortex changes from one storm to another. Indeed, for a strong magnetic storm, the eastward current is well established at mid latitudes about 45° N and for a weak magnetic storm, the eastward current is established toward the high latitudes (about 60° N, near the Joule heating region, resulting in a large "anti-Sq" current cell. The latitudinal profile of the Ddyn disturbance as well as the magnetic disturbance DP2 generated by the mechanism of prompt penetration of the magnetospheric convection electric field in general, show a weak disturbance at the low latitudes with a substantial amplification at the magnetic equator. Due to the intensity of the storm, the magnitude of the DP2 appears higher than the Ddyn over the American and Asian sector contrary to the African sector.

Problems of radiotherapy on the brain tumors in children less than two years of age

Energy Technology Data Exchange (ETDEWEB)

Miyagami, Mitsusuke; Tsubokawa, Takashi (Nihon Univ., Tokyo (Japan). School of Medicine); Nishimoto, Hiroshi; Ueno, Yuhichi

1990-06-01

Impaired growth and mental or developmental disturbance due to radiotherapy for 10 cases of brain tumors in the children ages less than 2 years old were evaluated. Six cases of brain tumor which did not involve the hypothalamic-pituitary axis, were followed more than 2 years after cranial or craniospinal irradiation. Four cases irradiated greater than 2900 rad to the whole brain all revealed markedly lower body heights than -2 SD of the medium. Growth impairment was found to be progressive over time, and markedly evident after 2 years following cranial or craniospinal radiotherapy. Somatomedin C in the blood was measured in 8 cases of brain tumors in childhood receiving radiotherapy. The measurement of Somatomedin C showed markedly low values measuring 0.19 to 0.54 U/ml (medium; 0.36 U/ml) in children having lower body height than -2 SD. Mental retardation or developmental disturbances were found in IQ or DQ tests in all of 5 infants or children younger than 2 years with brain tumors who got radiotherapy over 2900 rad to the whole brain. A case of craniopharyngioma, which had 5400 rad for tumor localization at the hypothalamus-pituitary axis and showed markedly low height, was given growth hormone and grew to normal height without distinct side effects. It was suggested that radiotherapy for brain tumors in infants or children should have special care in deciding the dose, field and time of radiation. If low height due to radiotherapy results, growth hormone therapy should be used for its treatment in childhood. (author).

Conservation of wildlife populations: factoring in incremental disturbance.

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Stewart, Abbie; Komers, Petr E

2017-06-01

Progressive anthropogenic disturbance can alter ecosystem organization potentially causing shifts from one stable state to another. This potential for ecosystem shifts must be considered when establishing targets and objectives for conservation. We ask whether a predator-prey system response to incremental anthropogenic disturbance might shift along a disturbance gradient and, if it does, whether any disturbance thresholds are evident for this system. Development of linear corridors in forested areas increases wolf predation effectiveness, while high density of development provides a safe-haven for their prey. If wolves limit moose population growth, then wolves and moose should respond inversely to land cover disturbance. Using general linear model analysis, we test how the rate of change in moose ( Alces alces ) density and wolf ( Canis lupus ) harvest density are influenced by the rate of change in land cover and proportion of land cover disturbed within a 300,000 km 2 area in the boreal forest of Alberta, Canada. Using logistic regression, we test how the direction of change in moose density is influenced by measures of land cover change. In response to incremental land cover disturbance, moose declines occurred where 43% of land cover was disturbed and wolf density declined. Wolves and moose appeared to respond inversely to incremental disturbance with the balance between moose decline and wolf increase shifting at about 43% of land cover disturbed. Conservation decisions require quantification of disturbance rates and their relationships to predator-prey systems because ecosystem responses to anthropogenic disturbance shift across disturbance gradients.

Occult CSF flow disturbance of patients with Alzheimer type dementia and vascular dementia

International Nuclear Information System (INIS)

Kono, Kazuhiko; Sugita, Yasuko; Funaki, Chiaki

1994-01-01

We report results of Iotrolan CT-cisternography on 41 demented patients (13 males and 28 females) to find 'occult normal pressure hydrocephalus'. These patients were suspected to have CSF flow disturbance from clinical symptoms and simple brain CT scan findings. Their average age, duration of dementia, and score of Hasegawa's dementia scale (HDS) were 76.2 years, 5.9 years, 9.5/32.5,respectively. Before performing CT-cisternography, clinical diagnosis for their dementia were vascular dementia in 18 patients. Alzheimer type dementia in 12, suspect of NPH in 5, and other diagnoses in 6. From the results of cisternography, we found 13 patients with CSF flow disturbance (contrast material remained in the ventricle more than 48 hours after injection), and 17 patients with normal CSF flow. The former showed lower scores of HDS, higher urinary incontinence scores and smaller areas of the interhemispheric fissure on CT scan than the latter. But the former showed no significant difference from the latter in the average age, duration of dementia and width of the ventricles. (author)

How disturbance, competition, and dispersal interact to prevent tree range boundaries from keeping pace with climate change.

Science.gov (United States)

Liang, Yu; Duveneck, Matthew J; Gustafson, Eric J; Serra-Diaz, Josep M; Thompson, Jonathan R

2018-01-01

Climate change is expected to cause geographic shifts in tree species' ranges, but such shifts may not keep pace with climate changes because seed dispersal distances are often limited and competition-induced changes in community composition can be relatively slow. Disturbances may speed changes in community composition, but the interactions among climate change, disturbance and competitive interactions to produce range shifts are poorly understood. We used a physiologically based mechanistic landscape model to study these interactions in the northeastern United States. We designed a series of disturbance scenarios to represent varied disturbance regimes in terms of both disturbance extent and intensity. We simulated forest succession by incorporating climate change under a high-emissions future, disturbances, seed dispersal, and competition using the landscape model parameterized with forest inventory data. Tree species range boundary shifts in the next century were quantified as the change in the location of the 5th (the trailing edge) and 95th (the leading edge) percentiles of the spatial distribution of simulated species. Simulated tree species range boundary shifts in New England over the next century were far below (usually change (usually more than 110 km over 100 years) under a high-emissions scenario. Simulated species` ranges shifted northward at both the leading edge (northern boundary) and trailing edge (southern boundary). Disturbances may expedite species' recruitment into new sites, but they had little effect on the velocity of simulated range boundary shifts. Range shifts at the trailing edge tended to be associated with photosynthetic capacity, competitive ability for light and seed dispersal ability, whereas shifts at the leading edge were associated only with photosynthetic capacity and competition for light. This study underscores the importance of understanding the role of interspecific competition and disturbance when studying tree range

miR-Let7A Controls the Cell Death and Tight Junction Density of Brain Endothelial Cells under High Glucose Condition.

Science.gov (United States)

Song, Juhyun; Yoon, So Ra; Kim, Oh Yoen

2017-01-01

Hyperglycemia-induced stress in the brain of patients with diabetes triggers the disruption of blood-brain barrier (BBB), leading to diverse neurological diseases including stroke and dementia. Recently, the role of microRNA becomes an interest in the research for deciphering the mechanism of brain endothelial cell damage under hyperglycemia. Therefore, we investigated whether mircoRNA Let7A (miR-Let7A) controls the damage of brain endothelial (bEnd.3) cells against high glucose condition. Cell viability, cell death marker expressions (p-53, Bax, and cleaved poly ADP-ribose polymerase), the loss of tight junction proteins (ZO-1 and claudin-5), proinflammatory response (interleukin-6, tumor necrosis factor- α ), inducible nitric oxide synthase, and nitrite production were confirmed using MTT, reverse transcription-PCR, quantitative-PCR, Western blotting, immunofluorescence, and Griess reagent assay. miR-Let7A overexpression significantly prevented cell death and loss of tight junction proteins and attenuated proinflammatory response and nitrite production in the bEnd.3 cells under high glucose condition. Taken together, we suggest that miR-Let7A may attenuate brain endothelial cell damage by controlling cell death signaling, loss of tight junction proteins, and proinflammatory response against high glucose stress. In the future, the manipulation of miR-Let7A may be a novel solution in controlling BBB disruption which leads to the central nervous system diseases.

Reaction Wheel Disturbance Model Extraction Software - RWDMES

Science.gov (United States)

Blaurock, Carl

2009-01-01

The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

The Significance of Brain Transcranial Sonography in Burning Mouth Syndrome: a Pilot Study.

Science.gov (United States)

Zavoreo, Iris; Vučićević, Vanja; Boras; Zadravec, Dijana; Bašić, Vanja; Kes; Ciliga, Dubravka; Gabrić, Dragana

2017-03-01

Burning mouth syndrome (BMS) is a chronic disorder which is affecting mostly postmenopausal women and is characterized by burning symptoms in the oral cavity on the clinically healthy oral mucosa. Also, the results of previous studies suggested a possible role of peripheral and/or central neurological disturbances in these patients. The aim of this study was to analyze patients with burning mouth syndrome using transcranial sonography. By use of transcranial sonography of the brain parenchyma, substantia nigra , midbrain raphe and brain nucleus were evaluated in 20 patients with BMS (64.7±12.3 years) and 20 controls with chronic pain in the lumbosacral region (61.5±15). Statistical analysis was performed by use of Student t test with significance set at pburning mouth syndrome might reflect central disturbances within this syndrome. Burning Mouth Syndrome; Transcranial Sonography; substantia nigra; Midbrain Raphe Nuclei; Red Nucleus.

Asymptotic tracking and disturbance rejection of the blood glucose regulation system.

Science.gov (United States)

Ashley, Brandon; Liu, Weijiu

2017-07-01

Type 1 diabetes patients need external insulin to maintain blood glucose within a narrow range from 65 to 108 mg/dl (3.6 to 6.0 mmol/l). A mathematical model for the blood glucose regulation is required for integrating a glucose monitoring system into insulin pump technology to form a closed-loop insulin delivery system on the feedback of the blood glucose, the so-called "artificial pancreas". The objective of this paper is to treat the exogenous glucose from food as a glucose disturbance and then develop a closed-loop feedback and feedforward control system for the blood glucose regulation system subject to the exogenous glucose disturbance. For this, a mathematical model for the glucose disturbance is proposed on the basis of experimental data, and then incorporated into an existing blood glucose regulation model. Because all the eigenvalues of the disturbance model have zero real parts, the center manifold theory is used to establish blood glucose regulator equations. We then use their solutions to synthesize a required feedback and feedforward controller to reject the disturbance and asymptotically track a constant glucose reference of 90  mg/dl. Since the regulator equations are nonlinear partial differential equations and usually impossible to solve analytically, a linear approximation solution is obtained. Our numerical simulations show that, under the linear approximate feedback and feedforward controller, the blood glucose asymptotically tracks its desired level of 90 mg/dl approximately. Copyright © 2017 Elsevier Inc. All rights reserved.

Chronic human disturbance affects plant trait distribution in a seasonally dry tropical forest

Science.gov (United States)

Sfair, Julia C.; de Bello, Francesco; de França, Thaysa Q.; Baldauf, Cristina; Tabarelli, Marcelo

2018-02-01

The effects of human disturbance on biodiversity can be mediated by environmental conditions, such as water availability, climate and nutrients. In general, disturbed, dry or nutrient-depleted soils areas tend to have lower taxonomic diversity. However, little is known about how these environmental conditions affect functional composition and intraspecific variability in tropical dry forests. We studied a seasonally dry tropical forest (SDTF) under chronic anthropogenic disturbance (CAD) along rainfall and soil nutrient gradients to understand how these factors influence the taxonomic and functional composition. Specifically we evaluated two aspects of CAD, wood extraction and livestock pressure (goat and cattle grazing), along soil fertility and rainfall gradients on shrub and tree traits, considering species turnover and intraspecific variability. In addition, we also tested how the traits of eight populations of the most frequent species are affected by wood extraction, livestock pressure, rainfall and soil fertility. In general, although CAD and environmental gradients affected each trait of the most widespread species differently, the most abundant species also had a greater variation of traits. Considering species turnover, wood extraction is associated with species with a smaller leaf area and lower investment in leaf mass, probably due to the indirect effects of this disturbance type on the vegetation, i.e. the removal of branches and woody debris clears the vegetation, favouring species that minimize water loss. Livestock pressure, on the other hand, affected intraspecific variation: the herbivory caused by goats and cattle promoted individuals which invest more in wood density and leaf mass. In this case, the change of functional composition observed is a direct effect of the disturbance, such as the decrease of palatable plant abundance by goat and cattle herbivory. In synthesis, CAD, rainfall and soil fertility can affect trait distribution at community

Elimination of zinc-65 from the brain under kainate-induced seizures.

Science.gov (United States)

Takeda, Atsushi; Hirate, Maki; Oku, Naoto

2004-04-01

On the basis of the previous evidence that 65Zn concentrations in the brain of EL (epilepsy) mice was affected by induction of seizures, 65Zn movement in the brain was quantitatively evaluated in ddY mice treated with kainate. Six days after intravenous injection of 65ZnCl2, mice were intraperitoneally injected with kainate (10 mg/kg x 6 times in 2 weeks). Myoclonic jerks were observed during treatment with kainate. Twenty days after 65Zn injection, 65Zn distribution in the brain was compared between the kainite-treated and control mice. 65Zn distribution in the brain of the kainate-treated mice was overall lower than in the control mice. 65Zn concentration was significantly decreased in the frontal cortex, hippocampal CA1, thalamus and hypothalamus by treatment with kainate. These results demonstrate that kainate-induced seizures are linked to decreased zinc concentrations in the brain.

Concepts and Challenges in Disturbance Hydrology

Science.gov (United States)

Ebel, B. A.; Mirus, B. B.

2016-12-01

Landscape disturbances are increasing, often promoted and enhanced by climate shifts and human activities. Insect infestations, wildfires, earthquakes, urban development, forest harvest, mineral and petroleum resource extraction, and hurricanes are common landscape disturbances that can have profound hydrologic consequences. These cause relatively abrupt changes in the landscape, which alter local processes on plots and hillslopes in addition to coarser-scale processes across watersheds through cross-scale interactions. Shifts in soil properties and cover of vegetation and leaf litter change the water storage or buffering capacity as well as the hydrologic functional connectivity across multiple scales. These changes increase the risk of catastrophic flooding, erosion, and mass movements that degrade water resources, ecosystem services, and protection from hydrologically driven natural hazards. Although it is imperative that we understand the hydrologic effects of these disturbances, several major barriers exist. Four challenges are: (i) overlapping disturbances in space and time with unknown recovery trajectories, (ii) a paucity of long-term recovery records (>5 years duration), (iii) inefficacy of traditional modeling and parameterization approaches, and (iv) lack of pre-disturbance characterization. Examples of these challenges will be presented along with proposed opportunities for improved mechanistic understanding of processes and thresholds in disturbance hydrology.

Nonunity gain minimal-disturbance measurement

DEFF Research Database (Denmark)

Sabuncu, Metin; Mišta, L.; Fiurášek, J.

2007-01-01

We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes...

Potential increases in natural disturbance rates could offset forest management impacts on ecosystem carbon stocks

Science.gov (United States)

Bradford, John B.; Jensen, Nicholas R.; Domke, Grant M.; D’Amato, Anthony W.

2013-01-01

Forested ecosystems contain the majority of the world’s terrestrial carbon, and forest management has implications for regional and global carbon cycling. Carbon stored in forests changes with stand age and is affected by natural disturbance and timber harvesting. We examined how harvesting and disturbance interact to influence forest carbon stocks over the Superior National Forest, in northern Minnesota. Forest inventory data from the USDA Forest Service, Forest Inventory and Analysis program were used to characterize current forest age structure and quantify the relationship between age and carbon stocks for eight forest types. Using these findings, we simulated the impact of alternative management scenarios and natural disturbance rates on forest-wide terrestrial carbon stocks over a 100-year horizon. Under low natural mortality, forest-wide total ecosystem carbon stocks increased when 0% or 40% of planned harvests were implemented; however, the majority of forest-wide carbon stocks decreased with greater harvest levels and elevated disturbance rates. Our results suggest that natural disturbance has the potential to exert stronger influence on forest carbon stocks than timber harvesting activities and that maintaining carbon stocks over the long-term may prove difficult if disturbance frequency increases in response to climate change.

Spatial Domain Adaptive Control of Nonlinear Rotary Systems Subject to Spatially Periodic Disturbances

Directory of Open Access Journals (Sweden)

Yen-Hsiu Yang

2012-01-01

Full Text Available We propose a generic spatial domain control scheme for a class of nonlinear rotary systems of variable speeds and subject to spatially periodic disturbances. The nonlinear model of the rotary system in time domain is transformed into one in spatial domain employing a coordinate transformation with respect to angular displacement. Under the circumstances that measurement of the system states is not available, a nonlinear state observer is established for providing the estimated states. A two-degree-of-freedom spatial domain control configuration is then proposed to stabilize the system and improve the tracking performance. The first control module applies adaptive backstepping with projected parametric update and concentrates on robust stabilization of the closed-loop system. The second control module introduces an internal model of the periodic disturbances cascaded with a loop-shaping filter, which not only further reduces the tracking error but also improves parametric adaptation. The overall spatial domain output feedback adaptive control system is robust to model uncertainties and state estimated error and capable of rejecting spatially periodic disturbances under varying system speeds. Stability proof of the overall system is given. A design example with simulation demonstrates the applicability of the proposed design.

Quality of Irrigation Water Affects Soil Functionality and Bacterial Community Stability in Response to Heat Disturbance.

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Frenk, Sammy; Hadar, Yitzhak; Minz, Dror

2018-02-15

Anthropogenic activities alter the structure and function of a bacterial community. Furthermore, bacterial communities structured by the conditions the anthropogenic activities present may consequently reduce their stability in response to an unpredicted acute disturbance. The present mesocosm-scale study exposed soil bacterial communities to different irrigation water types, including freshwater, fertilized freshwater, treated wastewater, and artificial wastewater, and evaluated their response to a disturbance caused by heat. These effectors may be considered deterministic and stochastic forces common in agricultural operations of arid and semiarid regions. Bacterial communities under conditions of high mineral and organic carbon availability (artificial wastewater) differed from the native bacterial community and showed a proteobacterial dominance. These bacterial communities had a lower resistance to the heat treatment disturbance than soils under conditions of low resource availability (high-quality treated wastewater or freshwater). The latter soil bacterial communities showed a higher abundance of operational taxonomic units (OTUs) classified as Bacilli These results were elucidated by soil under conditions of high resource availability, which lost higher degrees of functional potential and had a greater bacterial community composition change. However, the functional resilience, after the disturbance ended, was higher under a condition of high resource availability despite the bacterial community composition shift and the decrease in species richness. The functional resilience was directly connected to the high growth rates of certain Bacteroidetes and proteobacterial groups. A high stability was found in samples that supported the coexistence of both resistant OTUs and fast-growing OTUs. IMPORTANCE This report presents the results of a study employing a hypothesis-based experimental approach to reveal the forces involved in determining the stability of a

The content of catecholamines in the adrenal glands and sections of the brain under hypokinesia and injection of some neurotropic agents

Science.gov (United States)

Melnik, B. E.; Paladiy, E. S.

1980-01-01

The dynamics of catecholamine content were studied in the adrenal glands and in various region of the brain of white rats under hypokinesia and injections of neurotropic agents. Profound changes in body catecholamine balance occured as a result of prolonged acute restriction of motor activity. Adrenalin retention increased and noradrenanalin retention decreased in the adrenal glands, hypothalamus, cerebral hemispheres, cerebellum and medulla oblongata. Observed alterations in catecholamine retention varied depending upon the type of neurotropic substance utilized. Mellipramine increased catecholamine retention in the tissues under observation while spasmolytin brought about an increase in adrenalin concentration in the adrenals and a decrease in the brain.

Influence of disturbance on temperate forest productivity

Science.gov (United States)

Peters, Emily B.; Wythers, Kirk R.; Bradford, John B.; Reich, Peter B.

2013-01-01

Climate, tree species traits, and soil fertility are key controls on forest productivity. However, in most forest ecosystems, natural and human disturbances, such as wind throw, fire, and harvest, can also exert important and lasting direct and indirect influence over productivity. We used an ecosystem model, PnET-CN, to examine how disturbance type, intensity, and frequency influence net primary production (NPP) across a range of forest types from Minnesota and Wisconsin, USA. We assessed the importance of past disturbances on NPP, net N mineralization, foliar N, and leaf area index at 107 forest stands of differing types (aspen, jack pine, northern hardwood, black spruce) and disturbance history (fire, harvest) by comparing model simulations with observations. The model reasonably predicted differences among forest types in productivity, foliar N, leaf area index, and net N mineralization. Model simulations that included past disturbances minimally improved predictions compared to simulations without disturbance, suggesting the legacy of past disturbances played a minor role in influencing current forest productivity rates. Modeled NPP was more sensitive to the intensity of soil removal during a disturbance than the fraction of stand mortality or wood removal. Increasing crown fire frequency resulted in lower NPP, particularly for conifer forest types with longer leaf life spans and longer recovery times. These findings suggest that, over long time periods, moderate frequency disturbances are a relatively less important control on productivity than climate, soil, and species traits.

Finding disturbances in on-farm biogas production.

Science.gov (United States)

Antonio, Pereira-Querol Marco; Laura, Seppänen

2012-01-01

When implementing innovations, disturbances are very likely to take place. Disturbances are undesirable because they can lead to unwanted outcomes, such as economic losses and work overload to workers. However, they can be powerful opportunities for learning and re-designing innovations. Here, we will present activity theoretical tools for analyzing disturbances in a way that they could be used as learning opportunities. We illustrate the proposed tools by analyzing a disturbance that took place during the implementation of a project of biogas production. By interpreting the disturbance process with a network of activity systems, we found that on-farm disturbances were formed as ruptures, innovations and asynchronies originated in other activity systems. This finding suggests that disturbances are outcomes of the functioning of networks, rather than simple results of failure of individuals or technical devices. The proposed tools could be used in interventions to help practitioners and ergonomists to recognize the systemic and networked nature of problems, and therefore, realize that they may require the collaboration of actors from different activities. In this sense, disturbances may be turned into opportunities for learning and developing innovations. We conclude by discussing how the method could be used in ergonomic design and intervention.

Asymptotic stability and disturbance attenuation properties for a class of networked control systems

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

In this paper, stability and disturbance attenuation issues for a class of Networked Control Systems (NCSs)under uncertain access delay and packet dropout effects are considered. Our aim is to find conditions on the delay and packet dropout rate, under which the system stability and H∞ disturbance attenuation properties are preserved to a desired level. The basic idea in this paper is to formulate such Networked Control System as a discrete-time switched system. Then the NCSs' stability and performance problems can be reduced to the corresponding problems for switched systems, which have been studied for decades and for which a number of results are available in the literature. The techniques in this paper are based on recent progress in the discrete-time switched systems and piecewise Lyapunov functions.

Brain region specific mitophagy capacity could contribute to selective neuronal vulnerability in Parkinson's disease

Directory of Open Access Journals (Sweden)

Zabel Claus

2011-09-01

Full Text Available Abstract Parkinson's disease (PD is histologically well defined by its characteristic degeneration of dopaminergic neurons in the substantia nigra pars compacta. Remarkably, divergent PD-related mutations can generate comparable brain region specific pathologies. This indicates that some intrinsic region-specificity respecting differential neuron vulnerability exists, which codetermines the disease progression. To gain insight into the pathomechanism of PD, we investigated protein expression and protein oxidation patterns of three different brain regions in a PD mouse model, the PINK1 knockout mice (PINK1-KO, in comparison to wild type control mice. The dysfunction of PINK1 presumably affects mitochondrial turnover by disturbing mitochondrial autophagic pathways. The three brain regions investigated are the midbrain, which is the location of substantia nigra; striatum, the major efferent region of substantia nigra; and cerebral cortex, which is more distal to PD pathology. In all three regions, mitochondrial proteins responsible for energy metabolism and membrane potential were significantly altered in the PINK1-KO mice, but with very different region specific accents in terms of up/down-regulations. This suggests that disturbed mitophagy presumably induced by PINK1 knockout has heterogeneous impacts on different brain regions. Specifically, the midbrain tissue seems to be most severely hit by defective mitochondrial turnover, whereas cortex and striatum could compensate for mitophagy nonfunction by feedback stimulation of other catabolic programs. In addition, cerebral cortex tissues showed the mildest level of protein oxidation in both PINK1-KO and wild type mice, indicating either a better oxidative protection or less reactive oxygen species (ROS pressure in this brain region. Ultra-structural histological examination in normal mouse brain revealed higher incidences of mitophagy vacuoles in cerebral cortex than in striatum and substantia

Sleep disturbances and glucose homeostasis

NARCIS (Netherlands)

Barf, R. Paulien; Scheurink, Anton J.W.

2011-01-01

Sleep disturbances, induced by either lifestyle, shift work or sleeping disorders, have become more prevalent in our 24/7 Western society. Sleep disturbances are associated with impaired health including metabolic diseases such as obesity and type 2 diabetes. The question remains whether there is a

Modelling natural disturbances in forest ecosystems: a review

OpenAIRE

Seidl, Rupert; Fernandes, Paulo M.; Fonseca, Teresa F.; Gillet, François; Jönsson, Anna Maria; Merganičová, Katarína; Netherer, Sigrid; Arpaci, Alexander; Bontemps, Jean-Daniel; Bugmann, Harald

2011-01-01

Natural disturbances play a key role in ecosystem dynamics and are important factors for sustainable forest ecosystem management. Quantitative models are frequently employed to tackle the complexities associated with disturbance processes. Here we review the wide variety of approaches to modelling natural disturbances in forest ecosystems, addressing the full spectrum of disturbance modelling from single events to integrated disturbance regimes. We applied a general, process-based framework f...

Platelet activation and dysfunction in a large-animal model of traumatic brain injury and hemorrhage

DEFF Research Database (Denmark)

Sillesen, Martin; Johansson, Pär I; Rasmussen, Lars S

2013-01-01

Traumatic brain injury (TBI) and hemorrhage are the leading causes of trauma-related mortality. Both TBI and hemorrhage are associated with coagulation disturbances, including platelet dysfunction. We hypothesized that platelet dysfunction could be detected early after injury...

The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity

NARCIS (Netherlands)

Bongers, F.; Poorter, L.; Hawthorne, W.D.; Sheil, D.

2009-01-01

The intermediate disturbance hypothesis (IDH) predicts local species diversity to be maximal at an intermediate level of disturbance. Developed to explain species maintenance and diversity patterns in species-rich ecosystems such as tropical forests, tests of IDH in tropical forest remain scarce,

Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

Science.gov (United States)

Reyer, Christopher P. O.; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G.; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P.; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Guerra Hernández, Juan; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J.; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A.; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E.; Hanewinkel, Marc

2017-03-01

Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

Science.gov (United States)

Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

2017-01-01

Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures. PMID:28855959

Reduced astrocyte density underlying brain volume reduction in activity-based anorexia rats

Science.gov (United States)

Frintrop, Linda; Liesbrock, Johanna; Paulukat, Lisa; Johann, Sonja; Kas, Martien J; Tolba, Rene; Heussen, Nicole; Neulen, Joseph; Konrad, Kerstin; Herpertz-Dahlmann, Beate; Beyer, Cordian; Seitz, Jochen

2018-04-01

Severe grey and white matter volume reductions were found in patients with anorexia nervosa (AN) that were linked to neuropsychological deficits while their underlying pathophysiology remains unclear. For the first time, we analysed the cellular basis of brain volume changes in an animal model (activity-based anorexia, ABA). Female rats had 24 h/day running wheel access and received reduced food intake until a 25% weight reduction was reached and maintained for 2 weeks. In ABA rats, the volumes of the cerebral cortex and corpus callosum were significantly reduced compared to controls by 6% and 9%, respectively. The number of GFAP-positive astrocytes in these regions decreased by 39% and 23%, total astrocyte-covered area by 83% and 63%. In neurons no changes were observed. The findings were complemented by a 60% and 49% reduction in astrocyte (GFAP) mRNA expression. Volumetric brain changes in ABA animals mirror those in human AN patients. These alterations are associated with a reduction of GFAP-positive astrocytes as well as GFAP expression. Reduced astrocyte functioning could help explain neuronal dysfunctions leading to symptoms of rigidity and impaired learning. Astrocyte loss could constitute a new research target for understanding and treating semi-starvation and AN.

A National Disturbance Modeling System to Support Ecological Carbon Sequestration Assessments

Science.gov (United States)

Hawbaker, T. J.; Rollins, M. G.; Volegmann, J. E.; Shi, H.; Sohl, T. L.

2009-12-01

The U.S. Geological Survey (USGS) is prototyping a methodology to fulfill requirements of Section 712 of the Energy Independence and Security Act (EISA) of 2007. At the core of the EISA requirements is the development of a methodology to complete a two-year assessment of current carbon stocks and other greenhouse gas (GHG) fluxes, and potential increases for ecological carbon sequestration under a range of future climate changes, land-use / land-cover configurations, and policy, economic and management scenarios. Disturbances, especially fire, affect vegetation dynamics and ecosystem processes, and can also introduce substantial uncertainty and risk to the efficacy of long-term carbon sequestration strategies. Thus, the potential impacts of disturbances need to be considered under different scenarios. As part of USGS efforts to meet EISA requirements, we developed the National Disturbance Modeling System (NDMS) using a series of statistical and process-based simulation models. NDMS produces spatially-explicit forecasts of future disturbance locations and severity, and the resulting effects on vegetation dynamics. NDMS is embedded within the Forecasting Scenarios of Future Land Cover (FORE-SCE) model and informs the General Ensemble Biogeochemical Modeling System (GEMS) for quantifying carbon stocks and GHG fluxes. For fires, NDMS relies on existing disturbance histories, such as the Landsat derived Monitoring Trends in Burn Severity (MTBS) and Vegetation Change Tracker (VCT) data being used to update LANDFIRE fuels data. The MTBS and VCT data are used to parameterize models predicting the number and size of fires in relation to climate, land-use/land-cover change, and socioeconomic variables. The locations of individual fire ignitions are determined by an ignition probability surface and then FARSITE is used to simulate fire spread in response to weather, fuels, and topography. Following the fire spread simulations, a burn severity model is used to determine annual

Relative impact of previous disturbance history on the likelihood of additional disturbance in the Northern United States Forest Service USFS Region

Science.gov (United States)

Hernandez, A. J.

2015-12-01

The Landsat archive is increasingly being used to detect trends in the occurrence of forest disturbance. Beyond information about the amount of area affected, forest managers need to know if and how disturbance regimes change. The National Forest System (NFS) has developed a comprehensive plan for carbon monitoring that requires a detailed temporal mapping of forest disturbances across 75 million hectares. A long-term annual time series that shows the timing, extent, and type of disturbance beginning in 1990 and ending in 2011 has been prepared for several USFS Regions, including the Northern Region. Our mapping starts with an automated detection of annual disturbances using a time series of historical Landsat imagery. Automated detections are meticulously inspected, corrected and labeled using various USFS ancillary datasets. The resulting maps of verified disturbance show the timing and types are fires, harvests, insect activity, disease, and abiotic (wind, drought, avalanche) damage. Also, the magnitude of each change event is modeled in terms of the proportion of canopy cover lost. The sequence of disturbances for every pixel since 1990 has been consistently mapped and is available across the entirety of NFS. Our datasets contain sufficient information to describe the frequency of stand replacement, as well as how often disturbance results in only a partial loss of canopy. This information provides empirical insight into how an initial disturbance may predispose a stand to further disturbance, and it also show a climatic signal in the occurrence of processes such as fire and insect epidemics. Thus, we have the information to model the likelihood of occurrence of certain disturbances after a given event (i.e. if we have a fire in the past what does that do to the likelihood of occurrence of insects in the future). Here, we explore if previous disturbance history is a reliable predictor of additional disturbance in the future and we present results of applying

Sediment Dynamics Within Buffer Zone and Sinkhole Splay Areas Under Extreme Soil Disturbance Conditions.

Science.gov (United States)

Schoonover, Jon E; Crim, Jackie F; Williard, Karl W J; Groninger, John W; Zaczek, James J; Pattumma, Klairoong

2015-09-01

Sedimentation dynamics were assessed in sinkholes within training areas at Ft. Knox Military Installation, a karst landscape subjected to decades of tracked vehicle use and extreme soil disturbance. Sinkholes sampled were sediment-laden and behaved as intermittent ponds. Dendrogeomorphic analyses were conducted using willow trees (Salix spp.) located around the edge of 18 sinkholes to estimate historical sedimentation rates, and buried bottles were installed in 20 sinkholes at the center, outer edge, and at the midpoint between the center and edge to estimate annual sedimentation rates. Sedimentation data were coupled with vegetation characteristics of sinkhole buffers to determine relationships among these variables. The dendrogeomorphic method estimated an average accumulation rate of 1.27 cm year(-1) translating to a sediment loss rate of 46.1 metric ton year(-1) from the training areas. However, sediment export to sinkholes was estimated to be much greater (118.6 metric ton year(-1)) via the bottle method. These data suggest that the latter method provided a more accurate estimate since accumulation was greater in the center of sinkholes compared to the periphery where dendrogeomorphic data were collected. Vegetation data were not tightly correlated with sedimentation rates, suggesting that further research is needed to identify a viable proxy for direct measures of sediment accumulation in this extreme deposition environment. Mitigation activities for the sinkholes at Ft. Knox's tank training area, and other heavily disturbed karst environments where extreme sedimentation exists, should consider focusing on flow path and splay area management.

Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica - A Pilot Study.

Directory of Open Access Journals (Sweden)

Thomas Martin Doring

Full Text Available Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO using quantitative susceptibility mapping (QSM, a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y underwent MRI of the brain at 3 Tesla. Quantitative maps of the effective transverse relaxation rate (R2* and magnetic susceptibility were calculated and a blinded ROI-based group comparison analysis was performed. Normality of the data and differences between patients and controls were tested by Kolmogorov-Smirnov and t-test, respectively. Correlation with age was studied using Spearman's rank correlation and an ANCOVA-like analysis. Magnetic susceptibility values were decreased in the red nucleus (p0.95; between -15 and -22 ppb depending on reference region with a trend toward increasing differences with age. R2* revealed significantly decreased relaxation in the optic radiations of five of the 12 patients (p<0.0001; -3.136±0.567 s-1. Decreased relaxation in the optic radiation is indicative for demyelination, which is in line with previous findings. Decreased magnetic susceptibility in the red nucleus is indicative for a lower brain iron concentration, a chemical redistribution of iron into less magnetic forms, or both. Further investigations are necessary to elucidate the pathological cause or consequence of this finding.

Microbiota-Brain-Gut Axis and Neurodegenerative Diseases.

Science.gov (United States)

Quigley, Eamonn M M

2017-10-17

The purposes of this review were as follows: first, to provide an overview of the gut microbiota and its interactions with the gut and the central nervous system (the microbiota-gut-brain axis) in health, second, to review the relevance of this axis to the pathogenesis of neurodegenerative diseases, such as Parkinson's disease, and, finally, to assess the potential for microbiota-targeted therapies. Work on animal models has established the microbiota-gut-brain axis as a real phenomenon; to date, the evidence for its operation in man has been limited and has been confronted by considerable logistical challenges. Animal and translational models have incriminated a disturbed gut microbiota in a number of CNS disorders, including Parkinson's disease; data from human studies is scanty. While a theoretical basis can be developed for the use of microbiota-directed therapies in neurodegenerative disorders, support is yet to come from high-quality clinical trials. In theory, a role for the microbiota-gut-brain axis is highly plausible; clinical confirmation is awaited.

Hypobaric Hypoxia Imbalances Mitochondrial Dynamics in Rat Brain Hippocampus

Directory of Open Access Journals (Sweden)

Khushbu Jain

2015-01-01

Full Text Available Brain is predominantly susceptible to oxidative stress and mitochondrial dysfunction during hypobaric hypoxia, and therefore undergoes neurodegeneration due to energy crisis. Evidences illustrate a high degree of association for mitochondrial fusion/fission imbalance and mitochondrial dysfunction. Mitochondrial fusion/fission is a recently reported dynamic mechanism which frequently occurs among cellular mitochondrial network. Hence, the study investigated the temporal alteration and involvement of abnormal mitochondrial dynamics (fusion/fission along with disturbed mitochondrial functionality during chronic exposure to hypobaric hypoxia (HH. The Sprague-Dawley rats were exposed to simulated high altitude equivalent to 25000 ft for 3, 7, 14, 21, and 28 days. Mitochondrial morphology, distribution within neurons, enzyme activity of respiratory complexes, Δψm, ADP: ATP, and expression of fission/fusion key proteins were determined. Results demonstrated HH induced alteration in mitochondrial morphology by damaged, small mitochondria observed in neurons with disturbance of mitochondrial functionality and reduced mitochondrial density in neuronal processes manifested by excessive mitochondrial fragmentation (fission and decreased mitochondrial fusion as compared to unexposed rat brain hippocampus. The study suggested that imbalance in mitochondrial dynamics is one of the noteworthy mechanisms occurring in hippocampal neurons during HH insult.

Primary sleep disorders can cause long-term sleep disturbance in patients with autoimmune mediated limbic encephalitis.

Science.gov (United States)

Anderson, Kirstie N; Kelly, Thomas P; Griffiths, Timothy D

2013-07-01

Antibody mediated limbic encephalitis causes a sub acute encephalopathy with an amnestic syndrome, seizures and often an affective prodrome. Sleep disturbance including abnormal dream sleep and insomnia are described in a percentage of long-term survivors but there are very few detailed assessments of sleep disturbance in patients beyond the acute phase of illness. The objectives of this study were to understand the causes of sleep disturbance in the long-term survivors of antibody mediated limbic encephalitis. We screened twelve patients under long-term follow up with sleep questionnaires and went on to perform detailed sleep studies (polysomnography) in those who reported sleep disturbance. Two were found to have persistent, severe central and obstructive sleep apnoea and two others to have restless legs and periodic limb movements of sleep. This highlights the need to investigate sleep disturbance in this group of patients. Effective treatments may be available to improve quality of life and daytime function. Copyright © 2012 Elsevier B.V. All rights reserved.

On the Application of Joint-Domain Dictionary Mapping for Multiple Power Disturbance Assessment

Directory of Open Access Journals (Sweden)

Delong Cai

2018-02-01

Full Text Available This paper proposes a joint-domain dictionary mapping method to obtain high assessment accuracy of multiple power disturbances. Firstly, in order to achieve resolutions in both the time and frequency domains, a joint-domain dictionary is proposed which consists of a discrete Hartley base and an identity matrix. Due to the low correlation between the discrete Hartley base and the identity matrix, the joint-domain dictionary mapping can separately capture the approximations of the sinusoidal components and transients. Since the mapping coefficients contain the physical quantities, the eigenvalues of each component can be effectively estimated. A quantified eigenvalue classifier was designed for identifying power disturbances using the estimated eigenvalues. The proposed method was compared with several advanced methods through simulated power disturbances under different noise conditions, and actual data from the Institute of Electrical and Electronics Engineers Power and Energy Society database. The results reveal that the joint-domain dictionary mapping technique shows good performance on parameter estimation and recognition precision, even dealing with complicated multiple power disturbances.

Brain Events Underlying Episodic Memory Changes in Aging: A Longitudinal Investigation of Structural and Functional Connectivity.

Science.gov (United States)

Fjell, Anders M; Sneve, Markus H; Storsve, Andreas B; Grydeland, Håkon; Yendiki, Anastasia; Walhovd, Kristine B

2016-03-01

Episodic memories are established and maintained by close interplay between hippocampus and other cortical regions, but degradation of a fronto-striatal network has been suggested to be a driving force of memory decline in aging. We wanted to directly address how changes in hippocampal-cortical versus striatal-cortical networks over time impact episodic memory with age. We followed 119 healthy participants (20-83 years) for 3.5 years with repeated tests of episodic verbal memory and magnetic resonance imaging for quantification of functional and structural connectivity and regional brain atrophy. While hippocampal-cortical functional connectivity predicted memory change in young, changes in cortico-striatal functional connectivity were related to change in recall in older adults. Within each age group, effects of functional and structural connectivity were anatomically closely aligned. Interestingly, the relationship between functional connectivity and memory was strongest in the age ranges where the rate of reduction of the relevant brain structure was lowest, implying selective impacts of the different brain events on memory. Together, these findings suggest a partly sequential and partly simultaneous model of brain events underlying cognitive changes in aging, where different functional and structural events are more or less important in various time windows, dismissing a simple uni-factorial view on neurocognitive aging. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Clear signals or mixed messages: inter-individual emotion congruency modulates brain activity underlying affective body perception.

Science.gov (United States)

de Borst, A W; de Gelder, B

2016-08-01

The neural basis of emotion perception has mostly been investigated with single face or body stimuli. However, in daily life one may also encounter affective expressions by groups, e.g. an angry mob or an exhilarated concert crowd. In what way is brain activity modulated when several individuals express similar rather than different emotions? We investigated this question using an experimental design in which we presented two stimuli simultaneously, with same or different emotional expressions. We hypothesized that, in the case of two same-emotion stimuli, brain activity would be enhanced, while in the case of two different emotions, one emotion would interfere with the effect of the other. The results showed that the simultaneous perception of different affective body expressions leads to a deactivation of the amygdala and a reduction of cortical activity. It was revealed that the processing of fearful bodies, compared with different-emotion bodies, relied more strongly on saliency and action triggering regions in inferior parietal lobe and insula, while happy bodies drove the occipito-temporal cortex more strongly. We showed that this design could be used to uncover important differences between brain networks underlying fearful and happy emotions. The enhancement of brain activity for unambiguous affective signals expressed by several people simultaneously supports adaptive behaviour in critical situations. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Disorders of brain development and phakomatosis

International Nuclear Information System (INIS)

Merhemis, Z.

2006-01-01

Full text: Disorders of brain development and phakomatosis are resulting from disturbed embryonic-foetal development One third of all major embryological anomalies involve CNS, and over 2000 different anomalies have been described. Anomalies of the brain often cause foetal and neonatal death, and mental and physical retardation in pediatric group. The majority of disorders of brain development and phakomatosis are idiopathic, and most of them are not hereditary or familial. Ultrasonography plays the important role in screening foetal and neonatal brain, but after closure of fontanels it is difficult to find the acoustic window. CT has limited contrast resolution, and disadvantage exposing infant to ionizing radiation. It is helpful to demonstrate the presence of calcifications. MR imaging has proved to be a diagnostic tool of major importance in children with disorders of brain development and phakomatosis. The excellent grey/white matter differentiation and multiplanar imaging capabilities of MR allow a systematic analysis of the brain. Disorders occurring in the first 4 weeks of gestation: Disorders of neural tube closure; Chiari malformation; Cephaloceles; Dermoid/Epidermoid. Disorders occurring between 5 and 10 weeks of gestation: Holoprosencephaly; Septo-optic dysplasia; Diencephalic cyst; Dandy Walker complex; Mega cistern magna. Disorders occurring between 2 and 5 months of gestation: Disorders of sulcation and cellular migration; Lissencephaly; Pachigyria; Schizencephaly; Heterotopias; Megaencephaly; Polymicrogyria; Porencephaly; Arachnoid cyst. Corpus callosum anomalies. Phakomatosis: Neurocutaneous Syndromes Neurofibromatosis Type 1 and 2; Tuberous Sclerosis; von Hippel-Lindau disease; Studge-Weber sy; Osler-Weber- Rendu sy

Disturbance History,Spatial Variability, and Patterns of Biodiversity

Science.gov (United States)

Bendix, J.; Wiley, J. J.; Commons, M.

2012-12-01

The intermediate disturbance hypothesis predicts that species diversity will be maximized in environments experiencing intermediate intensity disturbance, after an intermediate timespan. Because many landscapes comprise mosaics with complex disturbance histories, the theory implies that each patch in those mosaics should have a distinct level of diversity reflecting combined impact of the magnitude of disturbance and the time since it occurred. We modeled the changing patterns of species richness across a landscape experiencing varied scenarios of simulated disturbance. Model outputs show that individual landscape patches have highly variable species richness through time, with the details reflecting the timing, intensity and sequence of their disturbance history. When the results are mapped across the landscape, the resulting temporal and spatial complexity illustrates both the contingent nature of diversity and the danger of generalizing about the impacts of disturbance.

Large Scale Functional Brain Networks Underlying Temporal Integration of Audio-Visual Speech Perception: An EEG Study.

Science.gov (United States)

Kumar, G Vinodh; Halder, Tamesh; Jaiswal, Amit K; Mukherjee, Abhishek; Roy, Dipanjan; Banerjee, Arpan

2016-01-01

Observable lip movements of the speaker influence perception of auditory speech. A classical example of this influence is reported by listeners who perceive an illusory (cross-modal) speech sound (McGurk-effect) when presented with incongruent audio-visual (AV) speech stimuli. Recent neuroimaging studies of AV speech perception accentuate the role of frontal, parietal, and the integrative brain sites in the vicinity of the superior temporal sulcus (STS) for multisensory speech perception. However, if and how does the network across the whole brain participates during multisensory perception processing remains an open question. We posit that a large-scale functional connectivity among the neural population situated in distributed brain sites may provide valuable insights involved in processing and fusing of AV speech. Varying the psychophysical parameters in tandem with electroencephalogram (EEG) recordings, we exploited the trial-by-trial perceptual variability of incongruent audio-visual (AV) speech stimuli to identify the characteristics of the large-scale cortical network that facilitates multisensory perception during synchronous and asynchronous AV speech. We evaluated the spectral landscape of EEG signals during multisensory speech perception at varying AV lags. Functional connectivity dynamics for all sensor pairs was computed using the time-frequency global coherence, the vector sum of pairwise coherence changes over time. During synchronous AV speech, we observed enhanced global gamma-band coherence and decreased alpha and beta-band coherence underlying cross-modal (illusory) perception compared to unisensory perception around a temporal window of 300-600 ms following onset of stimuli. During asynchronous speech stimuli, a global broadband coherence was observed during cross-modal perception at earlier times along with pre-stimulus decreases of lower frequency power, e.g., alpha rhythms for positive AV lags and theta rhythms for negative AV lags. Thus, our

I Meant to Do That: Determining the Intentions of Action in the Face of Disturbances.

Science.gov (United States)

Horowitz, Justin; Patton, James

2015-01-01

Our actions often do not match our intentions when there are external disturbances such as turbulence. We derived a novel modeling approach for determining this motor intent from targeted reaching motions that are disturbed by an unexpected force. First, we demonstrated how to mathematically invert both feedforward (predictive) and feedback controls to obtain an intended trajectory. We next examined the model's sensitivity to a realistic range of parameter uncertainties, and found that the expected inaccuracy due to all possible parameter mis-estimations was less than typical movement-to-movement variations seen when humans reach to similar targets. The largest sensitivity arose mainly from uncertainty in joint stiffnesses. Humans cannot change their intent until they acquire sensory feedback, therefore we tested the hypothesis that a straight-line intent should be evident for at least the first 120 milliseconds following the onset of a disturbance. As expected, the intended trajectory showed no change from undisturbed reaching for more than 150 milliseconds after the disturbance onset. Beyond this point, however, we detected a change in intent in five out of eight subjects, surprisingly even when the hand is already near the target. Knowing such an intent signal is broadly applicable: enhanced human-machine interaction, the study of impaired intent in neural disorders, the real-time determination (and manipulation) of error in training, and complex systems that embody planning such as brain machine interfaces, team sports, crowds, or swarms. In addition, observing intent as it changes might act as a window into the mechanisms of planning, correction, and learning.

I Meant to Do That: Determining the Intentions of Action in the Face of Disturbances.

Directory of Open Access Journals (Sweden)

Justin Horowitz

Full Text Available Our actions often do not match our intentions when there are external disturbances such as turbulence. We derived a novel modeling approach for determining this motor intent from targeted reaching motions that are disturbed by an unexpected force. First, we demonstrated how to mathematically invert both feedforward (predictive and feedback controls to obtain an intended trajectory. We next examined the model's sensitivity to a realistic range of parameter uncertainties, and found that the expected inaccuracy due to all possible parameter mis-estimations was less than typical movement-to-movement variations seen when humans reach to similar targets. The largest sensitivity arose mainly from uncertainty in joint stiffnesses. Humans cannot change their intent until they acquire sensory feedback, therefore we tested the hypothesis that a straight-line intent should be evident for at least the first 120 milliseconds following the onset of a disturbance. As expected, the intended trajectory showed no change from undisturbed reaching for more than 150 milliseconds after the disturbance onset. Beyond this point, however, we detected a change in intent in five out of eight subjects, surprisingly even when the hand is already near the target. Knowing such an intent signal is broadly applicable: enhanced human-machine interaction, the study of impaired intent in neural disorders, the real-time determination (and manipulation of error in training, and complex systems that embody planning such as brain machine interfaces, team sports, crowds, or swarms. In addition, observing intent as it changes might act as a window into the mechanisms of planning, correction, and learning.

A review of endocrine late effects in children after brain tumor therapy

International Nuclear Information System (INIS)

Marx, M.; Langer, T.; Beck, J.D.; Doerr, H.G.

1999-01-01

Background: Advances in the therapy of malignant brain tumors in children have led to a significant improvement in survival rates over the last few decades. As a result, the recognition and treatment of late effects have become more important. In addition to secondary tumors and deficiencies in cognitive and intellectual skills, the resulting endocrine disturbances play an important role. Method: Own data and literature review. Results: Deviations from the normal growth hormone secretion are usually recognized first and are most common, and have already been observed after conventional whole brain irradiation with 18 G. With some delay, other hypothalamopituitary deficiencies may occur, including panhypopituitarism. Puberty may come too early or too late or may not appear at all. Girls in particular, frequently experience an early and rapid pubertal development after brain tumor therapy, which may lead to further reduction in height due to an accelerated bone maturation. Functional disturbances of the thyroid and adrenal glands due to hypothalamic or pituitary deficiency are less common, and usually seen only after a radiation dose of over 40 Gy. Conclusion: Survivors of childhood brain tumors must be considered as long-term survivors, in whom the first therapy-induced long-term side effects appear almost immediately after the end of therapy. Maximum quality of life for the individual patient can only be achieved by long-term care and close cooperation of specialists in the different medical disciplines involved. (orig.) [de

An Adaptive Orientation Estimation Method for Magnetic and Inertial Sensors in the Presence of Magnetic Disturbances

Directory of Open Access Journals (Sweden)

Bingfei Fan

2017-05-01

Full Text Available Magnetic and inertial sensors have been widely used to estimate the orientation of human segments due to their low cost, compact size and light weight. However, the accuracy of the estimated orientation is easily affected by external factors, especially when the sensor is used in an environment with magnetic disturbances. In this paper, we propose an adaptive method to improve the accuracy of orientation estimations in the presence of magnetic disturbances. The method is based on existing gradient descent algorithms, and it is performed prior to sensor fusion algorithms. The proposed method includes stationary state detection and magnetic disturbance severity determination. The stationary state detection makes this method immune to magnetic disturbances in stationary state, while the magnetic disturbance severity determination helps to determine the credibility of magnetometer data under dynamic conditions, so as to mitigate the negative effect of the magnetic disturbances. The proposed method was validated through experiments performed on a customized three-axis instrumented gimbal with known orientations. The error of the proposed method and the original gradient descent algorithms were calculated and compared. Experimental results demonstrate that in stationary state, the proposed method is completely immune to magnetic disturbances, and in dynamic conditions, the error caused by magnetic disturbance is reduced by 51.2% compared with original MIMU gradient descent algorithm.

The interplay between climate change, forests, and disturbances

Science.gov (United States)

Virginia H. Dale; Linda A. Joyce; Steve McNulty; Ronald P. Neilson

2000-01-01

Climate change affects forests both directly and indirectly through disturbances. Disturbances are a natural and integral part of forest ecosystems, and climate change can alter these natural interactions. When disturbances exceed their natural range of variation, the change in forest structure and function may be extreme. Each disturbance affects forests differently....

The Cognitive Basis for Sentence Planning Difficulties in Discourse after Traumatic Brain Injury

Science.gov (United States)

Peach, Richard K.

2013-01-01

Purpose: Analyses of language production of individuals with traumatic brain injury (TBI) place increasing emphasis on microlinguistic (i.e., within-sentence) patterns. It is unknown whether the observed problems involve implementation of well-formed sentence frames or represent a fundamental linguistic disturbance in computing sentence structure.…

Brain SPECT analysis by 3D-SSP and clinical features of Parkinson's disease

International Nuclear Information System (INIS)

Mito, Yasunori; Yoshida, Kazuto; Makino, Kenichi; Yabe, Ichiro; Kikuchi, Seiji; Sasaki, Hidenao; Tashiro, Kunio

2006-01-01

The aim of the present study is to investigate the association of symptoms in Parkinson's disease (PD) with cerebral perfusion on single photon emission computed tomography (SPECT). The clinical features of PD were compared with SPECT images of the brain obtained by three-dimensional stereotactic surface projection (3D-SSP) analysis. Thirty-eight patients who had PD without dementia (17 men and 21 women with a mean age of 68.6±4.7 years) were enrolled in this study. Their symptoms were rated using the unified parkinson's disease rating scale (UPDRS). Within a week, all patients were examined by SPECT with I-123, and reconstructed images were analyzed with 3D-SSP using an image-analysis software, iSSP ver. 3.5. Data on brain surface perfusion extracted by 3D-SSP analysis were compared between the PD patients and the normal control group. The same comparisons were made for subgroups of PD patients with severe symptoms, such as tremor, gait disturbance, bradykinesia, and the UPDRS motor score. Cerebral perfusion was decreased at the anterior cingulate cortex and occipital lobe of the PD patients compared with the normal controls. In the subgroups with severe gait disturbance and severe bradykinesia, additional hypoperfusion was seen at the lateral frontal association and lateral temporal association and the medial frontal gyrus, and by the pixel-by-pixel comparison, perfusion was significantly decreased (p<0.05) at the medial frontal gyrus and anterior cingulate cortex compared with the normal control group. In PD patients, severe gait disturbance and bradykinesia may be correlated with hypoperfusion of the medial aspect of the frontal lobe. This suggests that functional disturbance of the supplementary motor area and other parts of the frontal lobe are involved in the development of gait disturbance and bradykinesia in PD. (author)

Sleep disturbances in critically ill patients in ICU: how much do we know?

DEFF Research Database (Denmark)

Boyko, Y.; Ording, H.; Jennum, Poul

2012-01-01

the underlying literature. There are no studies of level 1 evidence proving the positive impact of the tested interventions on the critically ill patients sleep pattern. Thus, disturbed sleep in critically ill patients with all the severe consequences remains an unresolved problem and needs further investigation.......Sleep disturbances in the intensive care unit (ICU) seem to lead to development of delirium, prolonged ICU stay, and increased mortality. That is why sufficient sleep is important for good outcome and recovery in critically ill patients. A variety of small studies reveal pathological sleep patterns...... in critically ill patients including abnormal circadian rhythm, high arousal and awakening index, reduced Slow Wave Sleep, and Rapid Eye Movement sleep. The purpose of this study is to summarise different aspects of sleep-awake disturbances, causes and handling methods in critically ill patients by reviewing...

Mammalian engineers drive soil microbial communities and ecosystem functions across a disturbance gradient.

Science.gov (United States)

Eldridge, David J; Delgado-Baquerizo, Manuel; Woodhouse, Jason N; Neilan, Brett A

2016-11-01

The effects of mammalian ecosystem engineers on soil microbial communities and ecosystem functions in terrestrial ecosystems are poorly known. Disturbance from livestock has been widely reported to reduce soil function, but disturbance by animals that forage in the soil may partially offset these negative effects of livestock, directly and/or indirectly by shifting the composition and diversity of soil microbial communities. Understanding the role of disturbance from livestock and ecosystem engineers in driving soil microbes and functions is essential for formulating sustainable ecosystem management and conservation policies. We compared soil bacterial community composition and enzyme concentrations within four microsites: foraging pits of two vertebrates, the indigenous short-beaked echidna (Tachyglossus aculeatus) and the exotic European rabbit (Oryctolagus cuniculus), and surface and subsurface soils along a gradient in grazing-induced disturbance in an arid woodland. Microbial community composition varied little across the disturbance gradient, but there were substantial differences among the four microsites. Echidna pits supported a lower relative abundance of Acidobacteria and Cyanobacteria, but a higher relative abundance of Proteobacteria than rabbit pits and surface microsites. Moreover, these microsite differences varied with disturbance. Rabbit pits had a similar profile to the subsoil or the surface soils under moderate and high, but not low disturbance. Overall, echidna foraging pits had the greatest positive effect on function, assessed as mean enzyme concentrations, but rabbits had the least. The positive effects of echidna foraging on function were indirectly driven via microbial community composition. In particular, increasing activity was positively associated with increasing relative abundance of Proteobacteria, but decreasing Acidobacteria. Our study suggests that soil disturbance by animals may offset, to some degree, the oft-reported negative

State-and-transition simulation modeling to compare outcomes of alternative management scenarios under two natural disturbance regimes in a forested landscape in northeastern Wisconsin, USA

Directory of Open Access Journals (Sweden)

Amanda Swearingen

2015-07-01

Full Text Available Comparisons of the potential outcomes of multiple land management strategies and an understanding of the influence of potential increases in climate-related disturbances on these outcomes are essential for long term land management and conservation planning. To provide these insights, we developed an approach that uses collaborative scenario development and state-and-transition simulation modeling to provide land managers and conservation practitioners with a comparison of potential landscapes resulting from alternative management scenarios and climate conditions, and we have applied this approach in the Wild Rivers Legacy Forest (WRLF area in northeastern Wisconsin. Three management scenarios were developed with input from local land managers, scientists, and conservation practitioners: 1 continuation of current management, 2 expanded working forest conservation easements, and 3 cooperative ecological forestry. Scenarios were modeled under current climate with contemporary probabilities of natural disturbance and under increased probability of windthrow and wildfire that may result from climate change in this region. All scenarios were modeled for 100 years using the VDDT/TELSA modeling suite. Results showed that landscape composition and configuration were relatively similar among scenarios, and that management had a stronger effect than increased probability of windthrow and wildfire. These findings suggest that the scale of the landscape analysis used here and the lack of differences in predominant management strategies between ownerships in this region play significant roles in scenario outcomes. The approach used here does not rely on complex mechanistic modeling of uncertain dynamics and can therefore be used as starting point for planning and further analysis.

A climatological morphology of ionospheric disturbances at high and polar latitudes

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Dimitris N. Fotiadis

2016-01-01

Full Text Available After a historical introduction on the first well-documented observations of ionospheric phenomena and a review of the current, state-of-the art polar ionospheric studies, a climatological morphology of the irregular F-region plasma structures at high and polar latitudes is being presented, following a feature-aided pattern recognition method. Using the available in three solar cycles hourly foF2 data from 18 ionosonde stations, an ionospheric definition of disturbed conditions, independent of any causative mechanism, is being applied and positive/negative disturbances of duration smaller than 24 hours are sorted out. No latitudinal/longitudinal bins or seasons are defined and disturbances in each month and station are handled separately while four local time intervals of storm commencement are considered, according to solar zenith angle. A median profile per disturbance is produced only when a minimum occurrence probability is satisfied. Non-systematic features are excluded from this analysis by careful selection of the time window under morphological investigation. First, the median profiles of disturbance patterns are fitted to standard distributions and then, if they fail, they are grouped according to their major characteristic features and are described by a dynamic variation envelope along with their distribution in space and time. The present model, while being a non-conditional stand-alone model of ionospheric storms at high and polar latitudes offered to radio users, may complement existing empirical models. Finally, the present model may ultimately reveal cause-effect relationships with geomagnetic field or interplanetary parameters after further correlation studies undertaken in the future.

Propagating Disturbances in Coronal Loops: A Detailed Analysis of Propagation Speeds

Science.gov (United States)

Kiddie, G.; De Moortel, I.; Del Zanna, G.; McIntosh, S. W.; Whittaker, I.

2012-08-01

Quasi-periodic disturbances have been observed in the outer solar atmosphere for many years. Although first interpreted as upflows (Schrijver et al., Solar Phys. 187, 261, 1999), they have been widely regarded as slow magneto-acoustic waves, due to their observed velocities and periods. However, recent observations have questioned this interpretation, as periodic disturbances in Doppler velocity, line width, and profile asymmetry were found to be in phase with the intensity oscillations (De Pontieu and McIntosh, Astrophys. J. 722, 1013, 2010; Tian, McIntosh, and De Pontieu, Astrophys. J. Lett. 727, L37, 2011), suggesting that the disturbances could be quasi-periodic upflows. Here we conduct a detailed analysis of the velocities of these disturbances across several wavelengths using the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). We analysed 41 examples, including both sunspot and non-sunspot regions of the Sun. We found that the velocities of propagating disturbances (PDs) located at sunspots are more likely to be temperature dependent, whereas the velocities of PDs at non-sunspot locations do not show a clear temperature dependence. This suggests an interpretation in terms of slow magneto-acoustic waves in sunspots but the nature of PDs in non-sunspot (plage) regions remains unclear. We also considered on what scale the underlying driver is affecting the properties of the PDs. Finally, we found that removing the contribution due to the cooler ions in the 193 Å wavelength suggests that a substantial part of the 193 Å emission of sunspot PDs can be attributed to the cool component of 193 Å.

Simulation of electron density disturbances of the ionospheric D region produced by high-energy particle fluxes

International Nuclear Information System (INIS)

Martynenko, S.I.

1989-01-01

Using the large-scale tim expansion analytical solutions of electron concentration balance equation in D-region of the ionosphere for pulsed and periodic changes in the rate of ion formatin under the effect of fluxes of precipitating high-energy particles are obtained. Possible effect of disturbances of temperature of nutrals is taken into account. On the basis of model representations the space-time structure of emerging ionospheric disturbances is discussed

The brain stem function in patients with brain bladder; Clinical evaluation using dynamic CT scan and auditory brainstem response

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Toshihiro (Yokohama City Univ. (Japan). Faculty of Medicine)

1990-11-01

A syndrome of detrusor-sphincter dyssynergia (DSD) is occasionally found in patients with brain bladder. To evaluate the brain stem function in cases of brain bladder, urodynamic study, dynamic CT scan of the brain stem (DCT) and auditory brainstem response (ABR) were performed. The region of interest of DCT aimed at the posterolateral portion of the pons. The results were analysed in contrast with the presense of DSD in urodynamic study. DCT studies were performed in 13 cases with various brain diseases and 5 control cases without neurological diseases. Abnormal patterns of the time-density curve consisted of low peak value, prolongation of filling time and low rapid washout ratio (low clearance ratio) of the contrast medium. Four of 6 cases with DSD showed at least one of the abnormal patterns of the time-density curve bilaterally. In 7 cases without DSD none showed bilateral abnormality of the curve and in 2 of 7 cases only unilateral abnormality was found. ABR was performed in 8 patients with brain diseases. The interpeak latency of the wave I-V (I-V IPL) was considered to be prolonged in 2 cases with DSD compared to that of 4 without DSD. In 2 cases with DSD who had normal DCT findings, measurement of the I-V IPL was impossible due to abnormal pattern of the ABR wave. Above mentioned results suggests the presence of functional disturbance at the posterolateral portion of the pons in cases of brain bladder with DSD. (author).

Natural disturbance impacts on Canada's forest carbon budget

International Nuclear Information System (INIS)

Kurz, W.

2004-01-01

Wildfire and insect outbreaks are major determinants of forest dynamics in Canada, transferring carbon within the ecosystem, releasing carbon into the atmosphere and influencing post-disturbance carbon dynamics. This paper discusses the impacts of global climate change on natural disturbances. Higher temperatures and drier conditions are likely to increase burned areas in Canada and will also increase the impacts of insects, allowing for an expanded range and stressing their host species. Long-term changes in disturbance regimes have already affected Canada's forest age-class structure. Statistics of lower disturbance periods and carbon production were compared with periods of higher disturbance. Scenario analyses were conducted for the period of 1996 to 2032, assuming that annual insect and fire disturbance rates in timber-productive forests were 20 per cent higher and carbon production 20 per cent lower than base scenarios using average disturbance rates. It was concluded that these conditions could cause carbon stocks in Canada's forests to decline. The future carbon balance of Canada's forests will be affected by the rate of natural and human-induced disturbances. 4 refs

Tools for determining critical levels of atmospheric ammonia under the influence of multiple disturbances

International Nuclear Information System (INIS)

Pinho, P.; Llop, E.; Ribeiro, M.C.; Cruz, C.; Soares, A.; Pereira, M.J.; Branquinho, C.

2014-01-01

Critical levels (CLEs) of atmospheric ammonia based on biodiversity changes have been mostly calculated using small-scale single-source approaches, to avoid interference by other factors, which also influence biodiversity. Thus, it is questionable whether these CLEs are valid at larger spatial scales, in a multi- disturbances context. To test so, we sampled lichen diversity and ammonia at 80 sites across a region with a complex land-cover including industrial and urban areas. At a regional scale, confounding factors such as industrial pollutants prevailed, masking the CLEs. We propose and use a new tool to calculate CLEs by stratifying ammonia concentrations into classes, and focusing on the highest diversity values. Based on the significant correlations between ammonia and biodiversity, we found the CLE of ammonia for Mediterranean evergreen woodlands to be 0.69 μg m −3 , below the previously accepted value of 1.9 μg m −3 , and below the currently accepted pan-European CLE of 1.0 μg m −3 . - Highlights: • Biodiversity responds to multiple disturbances. • This prevents calculation regional critical levels of atmospheric ammonia. • We propose a tool to overcome that, based on the maximum biodiversity observed. • Critical level for Mediterranean evergreen woodlands was revised down to 0.69 μg m −3 . - Critical levels of atmospheric ammonia have not been calculated at a regional scale. Using a new method, we revised down the current Mediterranean evergreen woodlands critical level to 0.69 μg m −3

The affection of the disturbance of the hydrodynamics of blood in case of stress on pathological increase of level of low density lipoproteins in blood. The formation of cylindrical plaques, and their participation in the development of acute ischemic disorders of heart and brain.

Science.gov (United States)

Rusanov, S E

2017-09-01

In this article is given the new insight about the affection of stress on the increase of level of low density lipoproteins (LDL) in the blood, which is connected with the disturbance of hydrodynamics in the bloodstream, the attention was paid to the cylindrical cholesterol plaque, and it's classification. The disturbance of hydrodynamics of blood under the stress leads to the formation of a cylindrical cholesterol plaque, which repeats the contour of the vessel, and leads to the ischemic disorders of the heart and brain. The cylindrical cholesterol plaque goes through several stages of development: friable, yielding, dense, old. In the case of destruction of friable, fresh cholesterol plaque, releases a big quantity of low-density lipoproteins. This leads to the pathological increase of level of LDL in the blood. In the case of long disturbance of hydrodynamics, occurs the formation of strong links between low-density lipoproteins. Yielding cholesterol plaque is formed. Further maturation of cylindrical cholesterol plaque, leads to it's densifying and damage. We may emphasize, that short periods of strong contraction and expansion of vessels lead to the increase of level of LDL in the blood. Self-dependent restoration of normal level of LDL in blood occurs in the case of restoration of pressure in the limits of numbers, which are specific for particular person, and which don't exceed the physiological standard. Among patients with long duration of stress, the duration of vasospasm increases. LDL, without having a possibility to crumble, begin to stick together and form the yielding cylindrical plaque. It is characterized by having of not so strong connection with the vascular wall, and maintains only at the expanse of iteration of the vascular wall, it has cylindrical shape, is elastic and yellow. The thickness and length of walls depends on the degree of cross-clamping during the time of formation of yielding cylindrical plaque. In the case of stopping of spasm

Recovery of lotic macroinvertebrate communities from disturbance

Science.gov (United States)

Wallace, J. Bruce

1990-09-01

Ecosystem disturbances produce changes in macrobenthic community structure (abundances, biomass, and production) that persist for a few weeks to many decades. Examples of disturbances with extremely long-term effects on benthic communities include contamination by persistent toxic agents, physical changes in habitats, and altered energy inputs. Stream size, retention, and local geomorphology may ameliorate the influence of disturbances on invertebrates. Disturbances can alter food webs and may select for favorable genotypes (e.g., insecticidal resistance). Introductions of pesticides into lotic ecosystems, which do not result in major physical changes within habitats, illustrate several factors that influence invertebrate recovery time from disturbance. These include: (1) magnitude of original contamination, toxicity, and extent of continued use; (2) spatial scale of the disturbance; (3) persistence of the pesticide; (4) timing of the contamination in relation to the life history stages of the organisms; (5) vagility of populations influenced by pesticides; and (6) position within the drainage network. The ability of macroinvertebrates to recolonize denuded stream habitats may vary greatly depending on regional life histories, dispersal abilities, and position within the stream network (e.g., headwaters vs larger rivers). Although downstream drift is the most frequently cited mechanism of invertebrate recolonization following disturbance in middle- and larger-order streams, evidence is presented that shows aerial recolonization to be potentially important in headwater streams. There is an apparent stochastic element operating for aerial recolonization, depending on the timing of disturbance and flight periods of various taxa. Available evidence indicates that recolonization of invertebrate taxa without an aerial adult stage requires longer periods of time than for those that possess winged, terrestrial adult stages (i.e., most insects). Innovative, manipulative

Advanced modelling of doubly fed induction generator wind turbine under network disturbance

DEFF Research Database (Denmark)

Seman, S.; Iov, Florin; Niiranen, J.

This paper presents a variable speed wind turbine simulator. The simulator is used for a 2 MW wind turbine transient behavior study during a short-term symmetrical network disturbance. The mechanical part of wind turbine model consists of the rotor aerodynamic model, the wind turbine control...... converter, the model of the main transformer and a simple model of the grid. The simulation results obtained by means of the detailed wind turbine model are compared with the results obtained from a simplified simulator with an analytical model and FEM model of DFIG. The comparison of the results shows...... and the drive train model. The Doubly Fed Induction Generator (DFIG) is represented by an analytical two-axis model with constant lumped parameters and by Finite Element Method (FEM) based model. The model of the DFIG is coupled with the model of the passive crowbar protected and DTC controlled frequency...

The inhibition of the kynurenine pathway prevents behavioral disturbances and oxidative stress in the brain of adult rats subjected to an animal model of schizophrenia.

Science.gov (United States)

Réus, Gislaine Z; Becker, Indianara R T; Scaini, Giselli; Petronilho, Fabricia; Oses, Jean P; Kaddurah-Daouk, Rima; Ceretta, Luciane B; Zugno, Alexandra I; Dal-Pizzol, Felipe; Quevedo, João; Barichello, Tatiana

2018-02-02

Evidence has shown that the kynurenine pathway (KP) plays a role in the onset of oxidative stress and also in the pathophysiology of schizophrenia. The aim of this study was to use a pharmacological animal model of schizophrenia induced by ketamine to investigate if KP inhibitors could protect the brains of Wistar rats against oxidative stress and behavioral changes. Ketamine, injected at the dose of 25mg/kg, increased spontaneous locomotor activity. However, the inhibitors of tryptophan 2,3-dioxygenase (TDO), indoleamine 2,3-dioxygenase (IDO) and kynurenine-3-monooxygenase (KMO) were able to reverse these changes. In addition, the IDO inhibitor prevented lipid peroxidation, and decreased the levels of protein carbonyl in the prefrontal cortex (PFC), hippocampus and striatum. It also increased the activity of superoxide dismutase (SOD) in the hippocampus, as well as increasing the levels of catalase activity in the PFC and hippocampus. The TDO inhibitor prevented lipid damage in the striatum and reduced the levels of protein carbonyl in the hippocampus and striatum. Also, the TDO inhibitor increased the levels of SOD activity in the striatum and CAT activity in the hippocampus of ketamine-induced pro-oxidant effects. Lipid damage was not reversed by the KMO inhibitor. The KMO inhibitor increased the levels of SOD activity in the hippocampus, and reduced the levels of protein carbonyl while elevating the levels of CAT activity in the striatum of rats that had been injected with ketamine. Our findings revealed that the KP pathway could be a potential mechanism by which a schizophrenia animal model induced by ketamine could cause interference by producing behavioral disturbance and inducing oxidative stress in the brain, suggesting that the inhibition of the KP pathway could be a potential target in treating schizophrenia. Copyright © 2017 Elsevier Inc. All rights reserved.

Targeting myeloid cells to the brain using non-myeloablative conditioning.

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Chotima Böttcher

Full Text Available Bone marrow-derived cells (BMDCs are able to colonize the central nervous system (CNS at sites of damage. This ability makes BMDCs an ideal cellular vehicle for transferring therapeutic genes/molecules to the CNS. However, conditioning is required for bone marrow-derived myeloid cells to engraft in the brain, which so far has been achieved by total body irradiation (TBI and by chemotherapy (e.g. busulfan treatment. Unfortunately, both regimens massively disturb the host's hematopoietic compartment. Here, we established a conditioning protocol to target myeloid cells to sites of brain damage in mice using non-myeloablative focal head irradiation (HI. This treatment was associated with comparatively low inflammatory responses in the CNS despite cranial radiation doses which are identical to TBI, as revealed by gene expression analysis of cytokines/chemokines such as CCL2, CXCL10, TNF-α and CCL5. HI prior to bone marrow transplantation resulted in much lower levels of blood chimerism defined as the percentage of donor-derived cells in peripheral blood ( 95% or busulfan treatment (> 50%. Nevertheless, HI effectively recruited myeloid cells to the area of motoneuron degeneration in the brainstem within 7 days after facial nerve axotomy. In contrast, no donor-derived cells were detected in the lesioned facial nucleus of busulfan-treated animals up to 2 weeks after transplantation. Our findings suggest that myeloid cells can be targeted to sites of brain damage even in the presence of very low levels of peripheral blood chimerism. We established a novel non-myeloablative conditioning protocol with minimal disturbance of the host's hematopoietic system for targeting BMDCs specifically to areas of pathology in the brain.

Animal responses to natural disturbance and climate extremes: a review

Science.gov (United States)

Sergio, Fabrizio; Blas, Julio; Hiraldo, Fernando

2018-02-01

-preparation for conservationists, as well as mentality changes for all. Under all conditions, disturbances may soon become the defining signatures of most ecosystems and the dynamic leitmotif of modern ecology.

Brain networks underlying mental imagery of auditory and visual information.

Science.gov (United States)

Zvyagintsev, Mikhail; Clemens, Benjamin; Chechko, Natalya; Mathiak, Krystyna A; Sack, Alexander T; Mathiak, Klaus

2013-05-01

Mental imagery is a complex cognitive process that resembles the experience of perceiving an object when this object is not physically present to the senses. It has been shown that, depending on the sensory nature of the object, mental imagery also involves correspondent sensory neural mechanisms. However, it remains unclear which areas of the brain subserve supramodal imagery processes that are independent of the object modality, and which brain areas are involved in modality-specific imagery processes. Here, we conducted a functional magnetic resonance imaging study to reveal supramodal and modality-specific networks of mental imagery for auditory and visual information. A common supramodal brain network independent of imagery modality, two separate modality-specific networks for imagery of auditory and visual information, and a common deactivation network were identified. The supramodal network included brain areas related to attention, memory retrieval, motor preparation and semantic processing, as well as areas considered to be part of the default-mode network and multisensory integration areas. The modality-specific networks comprised brain areas involved in processing of respective modality-specific sensory information. Interestingly, we found that imagery of auditory information led to a relative deactivation within the modality-specific areas for visual imagery, and vice versa. In addition, mental imagery of both auditory and visual information widely suppressed the activity of primary sensory and motor areas, for example deactivation network. These findings have important implications for understanding the mechanisms that are involved in generation of mental imagery. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Computer aided analysis of disturbances

International Nuclear Information System (INIS)

Baldeweg, F.; Lindner, A.

1986-01-01

Computer aided analysis of disturbances and the prevention of failures (diagnosis and therapy control) in technological plants belong to the most important tasks of process control. Research in this field is very intensive due to increasing requirements to security and economy of process control and due to a remarkable increase of the efficiency of digital electronics. This publication concerns with analysis of disturbances in complex technological plants, especially in so called high risk processes. The presentation emphasizes theoretical concept of diagnosis and therapy control, modelling of the disturbance behaviour of the technological process and the man-machine-communication integrating artificial intelligence methods, e.g., expert system approach. Application is given for nuclear power plants. (author)

Brain glucose transport and phosphorylation under acute insulin-induced hypoglycemia in mice: an 18F-FDG PET study.

Science.gov (United States)

Alf, Malte F; Duarte, João M N; Schibli, Roger; Gruetter, Rolf; Krämer, Stefanie D

2013-12-01

We addressed the questions of how cerebral glucose transport and phosphorylation change under acute hypoglycemia and what the underlying mechanisms of adaptation are. Quantitative (18)F-FDG PET combined with the acquisition of real-time arterial input function was performed on mice. Hypoglycemia was induced and maintained by insulin infusion. PET data were analyzed with the 2-tissue-compartment model for (18)F-FDG, and the results were evaluated with Michaelis-Menten saturation kinetics. Glucose clearance from plasma to brain (K1,glc) and the phosphorylation rate constant increased with decreasing plasma glucose (Gp), in particular at a Gp of less than 2.5 mmol/L. Estimated cerebral glucose extraction ratios taking into account an increased cerebral blood flow (CBF) at a Gp of less than 2 mmol/L were between 0.14 and 0.79. CBF-normalized K1,glc values were in agreement with saturation kinetics. Phosphorylation rate constants indicated intracellular glucose depletion at a Gp of less than 2-3 mmol/L. When brain regions were compared, glucose transport under hypoglycemia was lowest in the hypothalamus. Alterations in glucose transport and phosphorylation, as well as intracellular glucose depletion, under acute hypoglycemia can be modeled by saturation kinetics taking into account an increase in CBF. Distinct transport kinetics in the hypothalamus may be involved in its glucose-sensing function.

Autism as an adaptive common variant pathway for human brain development

Directory of Open Access Journals (Sweden)

Mark H. Johnson

2017-06-01

Full Text Available While research on focal perinatal lesions has provided evidence for recovery of function, much less is known about processes of brain adaptation resulting from mild but widespread disturbances to neural processing over the early years (such as alterations in synaptic efficiency. Rather than being viewed as a direct behavioral consequence of life-long neural dysfunction, I propose that autism is best viewed as the end result of engaging adaptive processes during a sensitive period. From this perspective, autism is not appropriately described as a disorder of neurodevelopment, but rather as an adaptive common variant pathway of human functional brain development.

Hydrological disturbance diminishes predator control in wetlands.

Science.gov (United States)

Dorn, Nathan J; Cook, Mark I

2015-11-01

Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

Sleep disturbances after non-cardiac surgery

DEFF Research Database (Denmark)

Rosenberg, Jacob

2001-01-01

. The sleep disturbances seem to be related to the magnitude of trauma and thereby to the surgical stress response and/or post-operative opioid administration. Post-operative sleep disturbances may contribute to the development of early post-operative fatigue, episodic hypoxaemia, haemodynamic instability......After major non-cardiac surgery sleep pattern is usually disturbed with initial suppression of rapid eye movement sleep with a subsequent rebound during the first post-operative week. Deep sleep is also suppressed for several days after the operation and subjective sleep quality is impaired...... and altered mental status, all with a potential negative effect on post-operative outcome. Minimizing surgical trauma and avoiding or minimizing use of opioids for pain relief may prevent or reduce post-operative sleep disturbances. Post-operative sleep pattern represents an important research field, since...

Information-disturbance tradeoff in quantum measurements

International Nuclear Information System (INIS)

Maccone, Lorenzo

2006-01-01

We present a simple information-disturbance tradeoff relation valid for any general measurement apparatus: The disturbance between input and output states is lower bounded by the information the apparatus provides in distinguishing these two states

Brain Injury Association of America

Science.gov (United States)

... Only) 1-800-444-6443 Welcome to the Brain Injury Association of America (BIAA) Brain injury is not an event or an outcome. ... misunderstood, under-funded neurological disease. People who sustain brain injuries must have timely access to expert trauma ...

Upregulation of transcription factor NRF2-mediated oxidative stress response pathway in rat brain under short-term chronic hypobaric hypoxia.

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Sethy, Niroj Kumar; Singh, Manjulata; Kumar, Rajesh; Ilavazhagan, Govindasamy; Bhargava, Kalpana

2011-03-01

Exposure to high altitude (and thus hypobaric hypoxia) induces electrophysiological, metabolic, and morphological modifications in the brain leading to several neurological clinical syndromes. Despite the known fact that hypoxia episodes in brain are a common factor for many neuropathologies, limited information is available on the underlying cellular and molecular mechanisms. In this study, we investigated the temporal effect of short-term (0-12 h) chronic hypobaric hypoxia on global gene expression of rat brain followed by detailed canonical pathway analysis and regulatory network identification. Our analysis revealed significant alteration of 33, 17, 53, 81, and 296 genes (p stress response pathway and genes were detected at all time points suggesting activation of NRF2-ARE antioxidant defense system. The results were further validated by assessing the expression levels of selected genes in temporal as well as brain regions with quantitative RT-PCR and western blot. In conclusion, our whole brain approach with temporal monitoring of gene expression patterns during hypobaric hypoxia has resulted in (1) deciphering sequence of pathways and signaling networks activated during onset of hypoxia, and (2) elucidation of NRF2-orchestrated antioxidant response as a major intrinsic defense mechanism. The results of this study will aid in better understanding and management of hypoxia-induced brain pathologies.

Effect of bulk modulus on deformation of the brain under rotational accelerations

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Ganpule, S.; Daphalapurkar, N. P.; Cetingul, M. P.; Ramesh, K. T.

2018-01-01

Traumatic brain injury such as that developed as a consequence of blast is a complex injury with a broad range of symptoms and disabilities. Computational models of brain biomechanics hold promise for illuminating the mechanics of traumatic brain injury and for developing preventive devices. However, reliable material parameters are needed for models to be predictive. Unfortunately, the properties of human brain tissue are difficult to measure, and the bulk modulus of brain tissue in particular is not well characterized. Thus, a wide range of bulk modulus values are used in computational models of brain biomechanics, spanning up to three orders of magnitude in the differences between values. However, the sensitivity of these variations on computational predictions is not known. In this work, we study the sensitivity of a 3D computational human head model to various bulk modulus values. A subject-specific human head model was constructed from T1-weighted MRI images at 2-mm3 voxel resolution. Diffusion tensor imaging provided data on spatial distribution and orientation of axonal fiber bundles for modeling white matter anisotropy. Non-injurious, full-field brain deformations in a human volunteer were used to assess the simulated predictions. The comparison suggests that a bulk modulus value on the order of GPa gives the best agreement with experimentally measured in vivo deformations in the human brain. Further, simulations of injurious loading suggest that bulk modulus values on the order of GPa provide the closest match with the clinical findings in terms of predicated injured regions and extent of injury.

Four-level time decomposition quasi-static power flow and successive disturbances analysis. [Power system disturbances

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Jovanovic, S M [Nikola Tesla Inst., Belgrade (YU)

1990-01-01

This paper presents a model and an appropriate numerical procedure for a four-level time decomposition quasi-static power flow and successive disturbances analysis of power systems. The analysis consists of the sequential computation of the zero, primary, secondary and tertiary quasi-static states and of the estimation of successive structural disturbances during the 1200 s dynamics after a structural disturbance. The model is developed by detailed inspection of the time decomposition characteristics of automatic protection and control devices. Adequate speed of the numerical procedure is attained by a specific application of the inversion matrix lemma and the decoupled model constant coefficient matrices. The four-level time decomposition quasi-static method is intended for security and emergency analysis. (author).

[The role of alterations in the brain signaling systems regulated by insulin, IGF-1 and leptin in the transition of impaired glucose tolerance to overt type 2 diabetes mellitus].

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Shpakov, A O

2014-01-01

One of the crucial factors leading to the development of pre-diabetes and type 2 diabetes mellitus (DM2) are the disturbances in the brain hormonal signaling systems regulated by insulin, insulin-like growth factor-1 (IGF-1) and leptin. The causes of these disturbances are the changes in the redox balance and lipid metabolism leading to lipotoxicity and endoplasmic reticulum stress in neuronal cells, as well as the dysfunctions in neurotransmitter systems of the brain that are functionally associated with insulin, IGF-1 and leptin signaling systems. The identification of molecular disturbances in insulin, IGF-1 and leptin systems of the brain in pre-diabetes and DM2 can be used for early diagnostics of these diseases, and to develop new strategies for preventive treatment of DM2 at the pre-diabetic stage. In the review, the literature data and the results of own investigations concerning the changes in the insulin, IGF-1 and leptin systems of the brain in pre-diabetes and DM2 and their role in the etiology and pathogenesis of DM2 are analyzed, and the approaches to restore the functional activity of these systems are discussed.

Microgravity Disturbance Predictions in the Combustion Integrated Rack

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Just, M.; Grodsinsky, Carlos M.

2002-01-01

This paper will focus on the approach used to characterize microgravity disturbances in the Combustion Integrated Rack (CIR), currently scheduled for launch to the International Space Station (ISS) in 2005. Microgravity experiments contained within the CIR are extremely sensitive to vibratory and transient disturbances originating on-board and off-board the rack. Therefore, several techniques are implemented to isolate the critical science locations from external vibration. A combined testing and analysis approach is utilized to predict the resulting microgravity levels at the critical science location. The major topics to be addressed are: 1) CIR Vibration Isolation Approaches, 2) Disturbance Sources and Characterization, 3) Microgravity Predictive Modeling, 4) Science Microgravity Requirements, 6) Microgravity Control, and 7) On-Orbit Disturbance Measurement. The CIR is using the Passive Rack Isolation System (PaRIS) to isolate the rack from offboard rack disturbances. By utilizing this system, CIR is connected to the U.S. Lab module structure by either 13 or 14 umbilical lines and 8 spring / damper isolators. Some on-board CIR disturbers are locally isolated by grommets or wire ropes. CIR's environmental and science on board support equipment such as air circulation fans, pumps, water flow, air flow, solenoid valves, and computer hard drives cause disturbances within the rack. These disturbers along with the rack structure must be characterized to predict whether the on-orbit vibration levels during experimentation exceed the specified science microgravity vibration level requirements. Both vibratory and transient disturbance conditions are addressed. Disturbance levels/analytical inputs are obtained for each individual disturber in a "free floating" condition in the Glenn Research Center (GRC) Microgravity Emissions Lab (MEL). Flight spare hardware is tested on an Orbital Replacement Unit (ORU) basis. Based on test and analysis, maximum disturbance level

Melatonin disturbs SUMOylation mediated crosstalk between c-Myc and Nestin via MT1 activation and promotes the sensitivity of Paclitaxel in brain cancer stem cells.

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Lee, Hyemin; Lee, Hyo-Jung; Jung, Ji Hoon; Shin, Eun Ah; Kim, Sung-Hoon

2018-04-14

Here the underlying antitumor mechanism of melatonin and its potency as a sensitizer of Paclitaxel was investigated in X02 cancer stem cells. Melatonin suppressed sphere formation and induced G2/M arrest in X02 cells expressing Nestin, CD133, CXCR4 and SOX-2 as biomarkers of stemness. Furthermore, melatonin reduced the expression of CDK2, CDK4, cyclin D1, cyclin E, and c-Myc and upregulated cyclin B1 in X02 cells. Notably, genes of c-Myc related mRNAs were differentially expressed in melatonin treated X02 cells by microarray analysis. Consistently, melatonin reduced the expression of c-Myc at mRNA and protein levels, which was blocked by MG132. Of note, overexpression of c-Myc increased the expression of Nestin, while overexpression of Nestin enhanced c-Myc through crosstalk despite different locations, nucleus and cytoplasm. Interestingly, melatonin attenuated small ubiquitin-related modifier-1 (SUMO-1) more than SUMO-2 or SUMO-3 and disturbed nuclear translocation of Nestin for direct binding to c-Myc by SUMOylation of SUMO-1 protein by immunofluorescence and immunoprecipitation. Also, melatonin reduced trimethylated histone H3K4me3 and H3K36me3 more than dimethylation in X02 cells by Western blotting and Chromatin immunoprecipitation assay. Notably, melatonin upregulated MT1, not MT2, in X02 cells and melatonin receptor inhibitor Luzindole blocked the ability of melatonin to decrease the expression of Nestin, p-c-Myc(S62) and c-Myc. Furthermore, melatonin promoted cytotoxicity, sub G1 accumulation and apoptotic body formation by Paclitaxcel in X02 cells. Taken together, these findings suggest that melatonin inhibits stemness via suppression of c-Myc, Nestin, and histone methylation via MT1 activation and promotes anticancer effect of Paclitaxcel in brain cancer stem cells. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

[Anti-Ma2, anti-NMDA-receptor and anti-GluRε2 limbic encephalitis with testicular seminoma: short-term memory disturbance].

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Kubota, Akihiro; Tajima, Takashi; Narukawa, Shinya; Yamazato, Masamizu; Fukaura, Hikoaki; Takahashi, Yukitoshi; Tanaka, Keiko; Shimizu, Jun; Nomura, Kyoichi

2012-01-01

A 36-year-old man presented with cognitive impairment and disturbance of short-term memory functions with character change. Cerebrospinal fluid analysis revealed no abnormalities; however, brain MRI revealed high-signal intensity from bilateral hippocampus lesions on fluid attenuated inversion recovery (FLAIR) images and T(2) weighted images. The 18F-fluorodeoxyglucose PET demonstrated high glucose uptake in the bilateral hippocampus lesions. He was diagnosed as limbic encephalitis, and was administered high-dose intravenous methylprednisolone and immune adsorption plasma therapy followed by intravenous immunoglobulin therapy. MRI abnormalities improved after treatment but recent memory disturbance remained. Ma2 antibody, NMDA-receptor antibody, and GluRε2 antibody were positive. Eleven months atter the onset of disease, the tumor was identified in left testicle by ultrasound and removed the tumor. The pathological findings were seminoma. We experienced a case of paraneoplastic limbic encephalitis associated with seminoma with short-term memory disturbance. The occurrence of paraneoplastic limbic encephalitis with antibodies against cell membrane (NMDA-receptor antibody and GluRε2 antibody) and intracellular (Ma2 antibody) is rare even in the literature.

The Storm Time Evolution of the Ionospheric Disturbance Plasma Drifts

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Zhang, Ruilong; Liu, Libo; Le, Huijun; Chen, Yiding; Kuai, Jiawei

2017-11-01

In this paper, we use the C/NOFS and ROCSAT-1 satellites observations to analyze the storm time evolution of the disturbance plasma drifts in a 24 h local time scale during three magnetic storms driven by long-lasting southward IMF Bz. The disturbance plasma drifts during the three storms present some common features in the periods dominated by the disturbance dynamo. The newly formed disturbance plasma drifts are upward and westward at night, and downward and eastward during daytime. Further, the disturbance plasma drifts are gradually evolved to present significant local time shifts. The westward disturbance plasma drifts gradually migrate from nightside to dayside. Meanwhile, the dayside downward disturbance plasma drifts become enhanced and shift to later local time. The local time shifts in disturbance plasma drifts are suggested to be mainly attributed to the evolution of the disturbance winds. The strong disturbance winds arisen around midnight can constantly corotate to later local time. At dayside the westward and equatorward disturbance winds can drive the F region dynamo to produce the poleward and westward polarization electric fields (or the westward and downward disturbance drifts). The present results indicate that the disturbance winds corotated to later local time can affect the local time features of the disturbance dynamo electric field.

Diet and Age Interactions with Regards to Cholesterol Regulation and Brain Pathogenesis

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Romina M. Uranga

2010-01-01

Full Text Available Cholesterol is an essential molecule for brain homeostasis; yet, hypercholesterolemia and its numerous complications are believed to play a role in promoting multiple aspects of brain pathogenesis. An ever increasing number of individuals in modern Western Society are regularly consuming diets high in fat which promote the development of hypercholesterolemia. Additionally, modern societies are becoming increasingly aged, causing a collision between increased hypercholesterolemia and increased aging, which will likely lead to the development of increased pathological conditions due to hypercholesterolemia, thereby promoting deleterious neurochemical and behavioral changes in the brain. Lastly, while beneficial in controlling cholesterol levels, the long-term use of statins itself may potentially promote adverse effects on brain homeostasis, although specifics on this remain largely unknown. This review will focus on linking the current understanding of diet-induced hypercholesterolemia (as well as statin use to the development of oxidative stress, neurochemical alterations, and cognitive disturbances in the aging brain.

Managing Sleep Disturbances in Cirrhosis

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Xun Zhao

2016-01-01

Full Text Available Sleep disturbances, particularly daytime sleepiness and insomnia, are common problems reported by patients suffering from liver cirrhosis. Poor sleep negatively impacts patients’ quality of life and cognitive functions and increases mortality. Although sleep disturbances can be an early sign of hepatic encephalopathy (HE, many patients without HE still complain of poor quality sleep. The pathophysiology of these disturbances is not fully understood but is believed to be linked to impaired hepatic melatonin metabolism. This paper provides an overview for the clinician of common comorbidities contributing to poor sleep in patients with liver disease, mainly restless leg syndrome and obstructive sleep apnea. It discusses nondrug and pharmacologic treatment options in these patients, such as the use of light therapy and histamine (H1 blockers.

POPULATION STRUCTURE AND SPATIAL DISTRIBUTION OF Ceratozamia mexicana BRONGN. (ZAMIACEAE IN PRESERVED AND DISTURBED ENVIRONMENTS

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Andrés Rivera-Fernández

2012-11-01

Full Text Available Vegetal populations are affected by biotic and abiotic factors that influence the regeneration processes. The aims of this study were to know the population structure of Ceratozamia mexicana under two contrasting conditions (conserved site and disturbed site, and to determine if the sexual structure, the population density and the spatial distribution of C. mexicana are modified by effect of disturbance. Eight plots of 25 m2 within each site (conserved and disturbed were used. The structure and spatial distribution of the sites were determined. Methods included analysis of variance, spatial distribution indexes, and climatic and edaphic factors determined by conventional methods for their comparison. The conserved site showed a demographic structure of an inverted "J", while the disturbed site varied slightly with more discontinuous distribution. Population density was 0.78 individuals/m2 in the conserved site and 0.26 individuals/m2 in the disturbed site. Spatial distribution for all development stages of the plant was random, with the exception of the seedling stage, which was aggregated. Results showed that perturbation decreases the density of plants and removes reproductive individuals, which threatens the persistence of the population.

Disturbance alters local-regional richness relationships in appalachian forests

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Belote, R.T.; Sanders, N.J.; Jones, R.H.

2009-01-01

Whether biological diversity within communities is limited by local interactions or regional species pools remains an important question in ecology. In this paper, we investigate how an experimentally applied tree-harvesting disturbance gradient influenced local-regional richness relationships. Plant species richness was measured at three spatial scales (2 ha = regional; 576 m2 and 1 m2 = local) on three occasions (one year pre-disturbance, one year post-disturbance, and 10 years post-disturbance) across five disturbance treatments (uncut control through clearcut) replicated throughout the southern Appalachian Mountains, USA. We investigated whether species richness in 576-m2 plots and 1-m2 subplots depended on species richness in 2-ha experimental units and whether this relationship changed through time before and after canopy disturbance. We found that, before disturbance, the relationship between local and regional richness was weak or nonexistent. One year after disturbance local richness was a positive function of regional richness, because local sites were colonized from the regional species pool. Ten years after disturbance, the positive relationship persisted, but the slope had decreased by half. These results suggest that disturbance can set the stage for strong influences of regional species pools on local community assembly in temperate forests. However, as time since disturbance increases, local controls on community assembly decouple the relationships between regional and local diversity. ?? 2009 by the Ecological Society of America.

The Relationship between Sleep Quality and Brain Amyloid Burden.

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Brown, Belinda M; Rainey-Smith, Stephanie R; Villemagne, Victor L; Weinborn, Michael; Bucks, Romola S; Sohrabi, Hamid R; Laws, Simon M; Taddei, Kevin; Macaulay, S Lance; Ames, David; Fowler, Christopher; Maruff, Paul; Masters, Colin L; Rowe, Christopher C; Martins, Ralph N

2016-05-01

To evaluate the association between self-reported sleep quality and levels of brain β-amyloid (Aβ) burden, and to determine the effect of the apolipoprotein E (APOE) ε4 allele on any associations found. This study is a cross-sectional analysis of 184 cognitively healthy men and women aged over 60 y. We measured sleep quality factors: specifically, sleep duration, latency (time taken to fall asleep), disturbances, efficiency, daytime dysfunction, and overall sleep quality, using the Pittsburgh Sleep Quality Index. All participants underwent Aβ positron emission tomography imaging for the quantification of brain Aβ burden and were APOE genotyped. Linear regression analyses were used to evaluate the relationship between sleep quality factors and brain Aβ burden, adjusting for age, body mass index, cardiovascular disease, and symptoms of depression, with APOE ε4 carriage entered as a moderator. Of the sleep factors, longer sleep latency was associated with higher levels of brain Aβ (B = 0.003 [standard error = 0.001], P = 0.02). APOE ε4 allele (carrier/noncarrier) did not moderate the relationship between sleep latency and brain Aβ burden. Our findings suggest a relationship between brain Aβ burden and sleep latency, independent of APOE ε4 genotype. © 2016 Associated Professional Sleep Societies, LLC.

Brain structural network topological alterations of the left prefrontal and limbic cortex in psychogenic erectile dysfunction.

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Chen, Jianhuai; Chen, Yun; Gao, Qingqiang; Chen, Guotao; Dai, Yutian; Yao, Zhijian; Lu, Qing

2018-05-01

Despite increasing understanding of the cerebral functional changes and structural abnormalities in erectile dysfunction, alterations in the topological organization of brain networks underlying psychogenic erectile dysfunction remain unclear. Here, based on the diffusion tensor image data of 25 patients and 26 healthy controls, we investigated the topological organization of brain structural networks and its correlations with the clinical variables using the graph theoretical analysis. Patients displayed a preserved overall small-world organization and exhibited a less connectivity strength in the left inferior frontal gyrus, amygdale and the right inferior temporal gyrus. Moreover, an abnormal hub pattern was observed in patients, which might disturb the information interactions of the remaining brain network. Additionally, the clustering coefficient of the left hippocampus was positively correlated with the duration of patients and the normalized betweenness centrality of the right anterior cingulate gyrus and the left calcarine fissure were negatively correlated with the sum scores of the 17-item Hamilton Depression Rating Scale. These findings suggested that the damaged white matter and the abnormal hub distribution of the left prefrontal and limbic cortex might contribute to the pathogenesis of psychogenic erectile dysfunction and provided new insights into the understanding of the pathophysiological mechanisms of psychogenic erectile dysfunction.

Cerebral Metabolism and the Role of Glucose Control in Acute Traumatic Brain Injury.

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Buitrago Blanco, Manuel M; Prashant, Giyarpuram N; Vespa, Paul M

2016-10-01

This article reviews key concepts of cerebral glucose metabolism, neurologic outcomes in clinical trials, the biology of the neurovascular unit and its involvement in secondary brain injury after traumatic brain insults, and current scientific and clinical data that demonstrate a better understanding of the biology of metabolic dysfunction in the brain, a concept now known as cerebral metabolic energy crisis. The use of neuromonitoring techniques to better understand the pathophysiology of the metabolic crisis is reviewed and a model that summarizes the triphasic view of cerebral metabolic disturbance supported by existing scientific data is outlined. The evidence is summarized and a template for future research provided. Copyright © 2016 Elsevier Inc. All rights reserved.

Brain limbic system-based intelligent controller application to lane change manoeuvre

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Kim, Changwon; Langari, Reza

2011-12-01

This paper presents the application of a novel neuromorphic control strategy for lane change manoeuvres in the highway environment. The lateral dynamics of a vehicle with and without wind disturbance are derived and utilised to implement a control strategy based on the brain limbic system. To show the robustness of the proposed controller, several disturbance conditions including wind, uncertainty in the cornering stiffness, and changes in the vehicle mass are investigated. To demonstrate the performance of the suggested strategy, simulation results of the proposed method are compared with the human driver model-based control scheme, which has been discussed in the literature. The simulation results demonstrate the superiority of the proposed controller in energy efficiency, driving comfort, and robustness.

Design of disturbances control model at automotive company

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Marie, I. A.; Sari, D. K.; Astuti, P.; Teorema, M.

2017-12-01

The discussion was conducted at PT. XYZ which produces automotive components and motorcycle products. The company produced X123 type cylinder head which is a motor vehicle forming component. The disturbances in the production system has affected the company performance in achieving the target of Key Performance Indicator (KPI). Currently, the determination of the percentage of safety stock of cylinder head products is not in accordance to the control limits set by the company (60% - 80%), and tends to exceed the control limits that cause increasing the inventory wastage in the company. This study aims to identify the production system disturbances that occurs in the production process of manufacturing components of X123 type cylinder head products and design the control model of disturbance to obtain control action and determine the safety stock policy in accordance with the needs of the company. The design stage has been done based on the Disturbance Control Model which already existing and customized with the company need in controlling the production system disturbances at the company. The design of the disturbances control model consists of sub-model of the risk level of the disturbance, sub-model of action status, sub-model action control of the disturbance, and sub-model of determining the safety stock. The model can assist the automotive company in taking the decision to perform the disturbances control action in production system cylinder head while controlling the percentage of the safety stock.

Characterizing sleeping habits and disturbances among Saudi adults.

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Al-Tannir, Mohamad; Kobrosly, Samer Y; Al-Badr, Ahmad H; Salloum, Nourhan A; Altannir, Youssef M

2016-12-01

To characterize sleeping habits, assess sleep disturbance prevalence, and identify associated factors among Saudi adults.  Methods: A total of 1720 adults were approached for this observational cross-sectional study between October 2014 and March 2015. The study took place in Riyadh, the capital of Saudi Arabia. We used a questionnaire to describe sleeping characteristics in relation to existing chronic diseases, smoking status, obesity, daily performance and sociodemographic variables. Results: The response rate was 79.6% (1369 participants), 61.6% have or may have sleeping disturbances of which 18.6% claimed either slowed or stopped breathing during sleep. Women reported a higher prevalence of sleep disturbances (65.2%). Feeling tired was significantly associated with sleep disturbance (49% versus 19.7%) (p greater than 0.001). Approximately 78.4% of those with sleep disturbance significantly believed that their ability to perform daily tasks is affected (p=0.005). Moreover, smoking and obesity were significantly associated with sleep disturbances (p less than 0.01). Participants with asthma, hypertension, chronic heart disease, and diabetes mellitus reported significantly more sleeping disturbance (p=0.016 to p=0.001). Conclusions: Sleep disturbances are associated with obesity, smoking, chronic health conditions, and lower performance among  Saudi adults.

DSOGI-PLL Based Power Control Method to Mitigate Control Errors Under Disturbances of Grid Connected Hybrid Renewable Power Systems

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Mehmet Emin Meral

2018-01-01

Full Text Available The control of power converter devices is one of the main research lines in interfaced renewable energy sources, such as solar cells and wind turbines. Therefore, suitable control algorithms should be designed in order to regulate power or current properly and attain a good power quality for some disturbances, such as voltage sag/swell, voltage unbalances and fluctuations, long interruptions, and harmonics. Various synchronisation techniques based control strategies are implemented for the hybrid power system applications under unbalanced conditions in literature studies. In this paper, synchronisation algorithms based Proportional-Resonant (PR power/current controller is applied to the hybrid power system (solar cell + wind turbine + grid, and Dual Second Order Generalized Integrator-Phase Locked Loop (DSOGI-PLL based PR controller in stationary reference frame provides a solution to overcome these problems. The influence of various cases, such as unbalance, and harmonic conditions, is examined, analysed and compared to the PR controllers based on DSOGI-PLL and SRF-PLL. The results verify the effectiveness and correctness of the proposed DSOGI-PLL based power control method.

Finite-time H∞ control for linear continuous system with norm-bounded disturbance

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Meng, Qingyi; Shen, Yanjun

2009-04-01

In this paper, the definition of finite-time H∞ control is presented. The system under consideration is subject to time-varying norm-bounded exogenous disturbance. The main aim of this paper is focused on the design a state feedback controller which ensures that the closed-loop system is finite-time bounded (FTB) and reduces the effect of the disturbance input on the controlled output to a prescribed level. A sufficient condition is presented for the solvability of this problem, which can be reduced to a feasibility problem involving linear matrix inequalities (LMIs). A detailed solving method is proposed for the restricted linear matrix inequalities. Finally, examples are given to show the validity of the methodology.

The potential role of Morus alba leaves extract on the brain of mice infected with Schistosoma mansoni.

Science.gov (United States)

Bauomy, Amira A

2014-01-01

Schistosomiasis is a neglected tropical disease which is associated with neuropsychiatric and neuropathological disorders. Herein, the main goal of the presented work is to investigate the effect of Morus alba leaves extract in mice brain infected with Schistosoma mansoni. Since, the resistance of Schistosomes to antischistosomal drug (praziquantel) has been examined, schistosomiasis induced brain oxidative stress as evidenced by the decrease of glutathione level, total antioxidant capacity and the activity of catalase significantly, while a significant elevation in the levels of nitrite/nitrate and malondialdhyde. In addition, the infection resulted in neurochemical disturbances, the main inhibitory amino acid, γ- aminobutyric acid level was decreased. In contrast, the level of chloride ions and acetylcholine esterase activity were significantly increased. Moreover, the histopathological section showed some impairments in the brain. The treatment with Morus alba leaves extract ameliorated the induced disturbances in schistosome-infected mice where the levels of non-enzymatic and enzymatic antioxidants were elevated. On the other hand, the levels of nitrite/nitrate and malondialdhyde were significantly reduced. Likewise, treatment of mice with Morus alba leaves extract improved the altered levels of γ- aminobutyric acid level and chloride ion. Also, it improved the recorded impairments of the histopathological section in the brain of schistosome infected mice.

An assessment of the iPad 2 as a CT teleradiology tool using brain CT with subtle intracranial hemorrhage under conventional illumination.

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Park, Joon Bum; Choi, Hyuk Joong; Lee, Jeong Hun; Kang, Bo Seung

2013-08-01

We examined the potential of the iPad 2 as a teleradiologic tool for evaluating brain computed tomography (CT) with subtle hemorrhage in the conventional lighting conditions which are common situations in the remote CT reading. The comparison of the clinician's performance was undertaken through detecting hemorrhage by the iPad 2 and the clinical liquid crystal display (LCD) monitor. We selected 100 brain CT exams performed for head trauma or headache. Fifty had subtle radiological signs of intracranial hemorrhage (ICH), while the other 50 showed no significant abnormality. Five emergency medicine physicians reviewed these brain CT scans using the iPad 2 and the LCD monitor, scoring the probability of ICH on each exam on a five-point scale. Result showed high sensitivities and specificities in both devices. We generated receiver operating characteristic curves and calculated the average area under the curve of the iPad 2 and the LCD (0.935 and 0.900). Using the iPad 2 and reliable internet connectivity, clinicians can provide remote evaluation of brain CT with subtle hemorrhage under suboptimal viewing condition. Considering the distinct advantages of the iPad 2, the popular out-of-hospital use of mobile CT teleradiology would be anticipated soon.

Effect of a Roughness Element on the Receptivity of a Hypersonic Boundary Layer over a Blunt Cone Due to Pulse Entropy Disturbance with a Single Frequency

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Zhenqing Wang

2018-05-01

Full Text Available A high-order finite difference method was used to simulate the hypersonic flow field over a blunt cone with different height roughness elements. The unsteady flow field induced by pulse disturbances was analyzed and compared with that under continuous disturbances. The temporal and spatial evolution characteristics of disturbances in the boundary layer were investigated and the propagation of different disturbance modes in the boundary layer was researched through the fast Fourier transform (FFT method. The effect of the roughness element on the receptivity characteristic of the hypersonic boundary layer under pulse entropy disturbances was explored. The results showed that the different mode disturbances near roughness in the boundary layer were enlarged in the upstream half of the roughness element and suppressed in the downstream half. However, the effect of roughness weakened gradually as the disturbance frequency increased in the boundary layer. A phenomenon of mode competition in the downstream region of the roughness element exited. As the disturbances propagated downstream, the fundamental mode gradually became the dominant mode. A certain promotion effect on the mode competition was induced by the roughness element and the effect was enhanced with the increase in the roughness element height.

300 Area Disturbance Report

Energy Technology Data Exchange (ETDEWEB)

LL Hale; MK Wright; NA Cadoret

1999-01-07

The objective of this study was to define areas of previous disturbance in the 300 Area of the U.S. Department of Energy (DOE) Hanford Site to eliminate these areas from the cultural resource review process, reduce cultural resource monitoring costs, and allow cultural resource specialists to focus on areas where subsurface disturbance is minimal or nonexistent. Research into available sources suggests that impacts from excavations have been significant wherever the following construction activities have occurred: building basements and pits, waste ponds, burial grounds, trenches, installation of subsurface pipelines, power poles, water hydrants, and well construction. Beyond the areas just mentioned, substrates in the' 300 Area consist of a complex, multidimen- sional mosaic composed of undisturbed stratigraphy, backfill, and disturbed sediments; Four Geographic Information System (GIS) maps were created to display known areas of disturbance in the 300 Area. These maps contain information gleaned from a variety of sources, but the primary sources include the Hanford GIS database system, engineer drawings, and historic maps. In addition to these maps, several assumptions can be made about areas of disturbance in the 300 Area as a result of this study: o o Buried pipelines are not always located where they are mapped. As a result, cultural resource monitors or specialists should not depend on maps depicting subsurface pipelines for accurate locations of previous disturbance. Temporary roads built in the early 1940s were placed on layers of sand and gravel 8 to 12 in. thick. Given this information, it is likely that substrates beneath these early roads are only minimally disturbed. Building foundations ranged from concrete slabs no more than 6 to 8 in. thick to deeply excavated pits and basements. Buildings constructed with slab foundations are more numerous than may be expected, and minimally disturbed substrates may be expected in these locations. Historic

Not only in the brain: Cabanis and the Montpellierian tradition of localization.

Science.gov (United States)

Kaitaro, T

2000-01-01

Antonio Damasio (1995) has recently presented evidence to the effect that we are perhaps wrong in thinking that it is only the brain that thinks. Rational decision making involves emotional reactions as a necessary condition and background. And since emotions involve bodily reactions which are not limited to the brain but which embrace the autonomous nervous system and the viscera, one could say that we actually think with our bodies and not merely with our brains. According to Damasio the incapacity of patients with frontal lobe pathology in decision making could be explained by a disturbance in emotional reactions involving the whole organism. Philosophical discussions concerning brains in a vat have completely forgotten these aspects of our mental life. Despite the fact that the idea that we think exclusively with our brains has during the modern age been a rather widely held "received view," there is a physiological and philosophical tradition which regarded mental functions as the result of the interaction of several organs, instead of seeing them as the result of the activity of the brain alone.

Fatty acid composition of total lipids and phospholipids of muscular tissue and brain of rats under the impact of vibration

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N. M. Kostyshyn

2016-06-01

Full Text Available Fatty acids are important structural components of biological membranes, energy substrate of cells involved in fixing phospholipid bilayer proteins, and acting as regulators and modulators of enzymatic activity. Under the impact of vibration oscillations there can occur shifts in the ratio of different groups of fatty acids, and degrees of their saturation may change. The imbalance between saturated, monounsaturated and polyunsaturated fatty acids, which occurs later in the cell wall, disrupts fluidity and viscosity of lipid phase and causes abnormal cellular metabolism. Aim. In order to study the impact of vibration on the level of fatty acids of total lipids in muscular tissue and fatty acid composition of phospholipids in muscles and brain, experimental animals have been exposed to vertical vibration oscillations with different frequency for 28 days. Methods and results. Tissues fragments of hip quadriceps and brain of rats were used for obtaining methyl esters of fatty acids studied by the method of gas-liquid chromatography. It was found that the lipid content, ratio of its separate factions and fatty acid composition in muscular tissue and brain of animals with the action of vibration considerably varies. With the increase of vibration acceleration tendency to increase in absolute quantity of total lipids fatty acids can be observed at the account of increased level of saturated and monounsaturated ones. These processes are caused by activation of self-defense mechanisms of the body under the conditions of deviations from stabilized physiological norm, since adaptation requires certain structural and energy costs. Increase in the relative quantity of saturated and monounsaturated fatty acids in phospholipids of muscles and brain and simultaneous reduction in concentration of polyunsaturated fatty acids are observed. Conclusion. These changes indicate worsening of structural and functional organization of muscles and brain cell membranes of

Rehabilitation after severe brain injury: a follow-up study of a behaviour modification approach.

OpenAIRE

Eames, P; Wood, R

1985-01-01

Twenty four patients with severe brain injury who had disturbed behaviours preventing rehabilitation or care in ordinary settings were treated in a token economy. This long-term follow-up study indicates that post-traumatic behaviour disorders can be lastingly improved, and that lengthy rehabilitation can have surprisingly good effects.

α(1)-adrenoceptor blocker naftopidil improves sleep disturbance with reduction in nocturnal urine volume.

Science.gov (United States)

Yokoyama, Osamu; Aoki, Yoshitaka; Tsujimura, Akira; Takao, Tetsuya; Namiki, Mikio; Okuyama, Akihiko

2011-04-01

To examine the mechanism underlying improvements in nocturia by α(1)-blockers, we investigated whether the α(1)-blocker naftopidil acts on nocturia with sleep disturbance using a frequency/volume chart (FVC). A total of 56 male patients with lower urinary tract symptoms were enrolled. The inclusion criteria were as follows: eight or more points on the I-PSS; three or more points on the I-PSS score for nocturia; and prostate volume larger than 20 ml. Patients received 50 mg of naftopidil once daily for 4 weeks, and non-responders received 75 mg for another 4 weeks. All patients were examined, and their data entered into FVC for 2 days before and after administration of naftopidil. Quality of sleep was also evaluated using modified Pittsburgh sleep quality index (PSQI). Patients with sleep quality scores of three or four were assigned to sleep disturbance group (n = 33), while those with scores of less than three were assigned to non-disturbance group (n = 23). After administration of naftopidil, total I-PSS decreased and nocturia score decreased from 3.5 to 2.6 (P < 0.01). Total mean score of modified PSQI in sleep disturbance group became significantly lower after administration of naftopidil (from 16.9 to 14.0; P < 0.01). Naftopidil significantly decreased nocturnal urine volume, resulting in a decrease in the nocturnal polyuria index in both sleep disturbance and non-disturbance groups. These results suggest that α(1)-blockers have the ability to normalize sleep disorders. Naftopidil improved nocturnal polyuria regardless of the presence of sleep disturbance, meaning that it might directly reduce nocturnal urine production.

Origin of hyperbolicity in brain-to-brain coordination networks

Science.gov (United States)

Tadić, Bosiljka; Andjelković, Miroslav; Šuvakov, Milovan

2018-02-01

Hyperbolicity or negative curvature of complex networks is the intrinsic geometric proximity of nodes in the graph metric space, which implies an improved network function. Here, we investigate hidden combinatorial geometries in brain-to-brain coordination networks arising through social communications. The networks originate from correlations among EEG signals previously recorded during spoken communications comprising of 14 individuals with 24 speaker-listener pairs. We find that the corresponding networks are delta-hyperbolic with delta_max=1 and the graph diameter D=3 in each brain. While the emergent hyperbolicity in the two-brain networks satisfies delta_max/D/2 neuronal correlation patterns ranging from weak coordination to super-brain structure. These topology features are in qualitative agreement with the listener’s self-reported ratings of own experience and quality of the speaker, suggesting that studies of the cross-brain connector networks can reveal new insight into the neural mechanisms underlying human social behavior.

Brain-computer interfacing under distraction: an evaluation study

DEFF Research Database (Denmark)

Brandl, Stephanie; Frølich, Laura; Höhne, Johannes

2016-01-01

Objective. While motor-imagery based brain-computer interfaces (BCIs) have been studied over many years by now, most of these studies have taken place in controlled lab settings. Bringing BCI technology into everyday life is still one of the main challenges in this field of research. Approach...

Disturbed prepulse inhibition in patients with schizophrenia is consequential to dysfunction of selective attention.

Science.gov (United States)

Scholes, Kirsty E; Martin-Iverson, Mathew T

2010-03-01

Controversy exists as to the cause of disturbed prepulse inhibition (PPI) in patients with schizophrenia. This study aimed to clarify the nature of PPI in schizophrenia using improved methodology. Startle and PPI were measured in 44 patients with schizophrenia and 32 controls across a range of startling stimulus intensities under two conditions, one while participants were attending to the auditory stimuli (ATTEND condition) and one while participants completed a visual task in order to ensure they were ignoring the auditory stimuli (IGNORE condition). Patients showed reduced PPI of R(MAX) (reflex capacity) and increased PPI of Hillslope (reflex efficacy) only under the INGORE condition, and failed to show the same pattern of attentional modulation of the reflex parameters as controls. In conclusion, disturbed PPI in schizophrenia appears to result from deficits in selective attention, rather than from preattentive dysfunction.

Mapping of forest disturbance magnitudes across the US National Forest System

Science.gov (United States)

Hernandez, A. J.; Healey, S. P.; Ramsey, R. D.; McGinty, C.; Garrard, C.; Lu, N.; Huang, C.

2013-12-01

A precise record in conjunction with ongoing monitoring of carbon pools constitutes essentials inputs for the continuous modernization of an ever- dynamic science such as climate change. This is particularly important in forested ecosystems for which accurate field archives are available and can be used in combination with historic satellite imagery to obtain spatially explicit estimates of several indicators that can be used in the assessment of said carbon pools. Many forest disturbance processes limit storage of carbon in forested ecosystems and thereby reduce those systems' capacity to mitigate changes in the global climate system. A component of the US National Forest System's (NFS) comprehensive plan for carbon monitoring includes accounting for mapped disturbances, such as fires, harvests, and insect activity. A long-term time series of maps that show the timing, extent, type, and magnitude of disturbances going back to 1990 has been prepared for the United States Forest Service (USFS) Northern Region, and is currently under preparation for the rest of the NFS regions covering more than 75 million hectares. Our mapping approach starts with an automated initial detection of annual disturbances using imagery captured within the growing season from the Landsat archive. Through a meticulous process, the initial detections are then visually inspected, manually corrected and labeled using various USFS ancillary datasets and Google Earth high-resolution historic imagery. We prepared multitemporal models of percent canopy cover and live tree carbon (T/ha) that were calibrated with extensive (in excess of 2000 locations) field data from the US Forest Service Forest Inventory and Analysis program (FIA). The models were then applied to all the years of the radiometrically corrected and normalized Landsat time series in order to provide annual spatially explicit estimates of the magnitude of change in terms of these two attributes. Our results provide objective, widely

Irreversible amnesia in rats and edible snails under conditions of associative memory reconsolidation disturbance caused by NMDA-glutamate receptor antagonist.

Science.gov (United States)

Storozheva, Z I; Solntseva, S V; Nikitin, V P; Proshin, A T; Sherstnev, V V

2011-01-01

The effect of MK-801, an antagonist to NMDA-glutamate receptors, on reconsolidation of olfactory discrimination task in rats and taste discrimination in edible snails was examined. Twenty-four hours after conditioning, the animals received a single systemic injection of MK-801 followed by a reminding conditional stimulus. Disturbances in retrieval of the acquired task were observed 10 days after injection followed by a reminding procedure. Repeated conditioning of these animals did not restore the task. Injection of MK-801 without reminding stimulation had no effect on task retention. Thus, disturbances of NMDA-dependent reconsolidation of the associative memory in animals of different taxonomic groups irreversibly eliminated long-term memory.

The reciprocal associations between identity disturbance, relationship disturbance, and suicidal ideation among Chinese adolescents: A three-wave cross-lag study.

Science.gov (United States)

Ren, Yaxuan; Zhang, Xu; You, Jianing; Jiang, Yongqiang; Lin, Min-Pei; Leung, Freedom

2017-12-18

Adolescence is a developmental period associated with a heightened risk for suicidal ideation. During this phase of life, individuals tend to focus on both intrapersonal self and interpersonal relationships. Thus, it is of much significance to understand the roles of intrapersonal and interpersonal factors in the development of suicidal ideation among adolescents. The present study examined the reciprocal associations between identity disturbance, relationship disturbance, and suicidal ideation by using a three-wave cross-lag model in a sample of adolescents. A number of 3,600 Chinese adolescents (56.6% females, mean age = 14.58 years) completed questionnaires assessing the three main study variables as well as depressive symptoms, anxiety, and suicidal attempts three times at 6-month intervals. After controlling for gender, age, depressive symptoms, anxiety, and suicidal attempts, relationship disturbance significantly predicted suicidal ideation over time, and vice versa. Suicidal ideation significantly predicted identity disturbance over time, but not vice versa. We also found the mediating effect of relationship disturbance in the path from identity disturbance to suicidal ideation. The results suggested the important role of previous relationship disturbance in predicting later suicidal ideation. Theoretical and clinical implications of these findings were discussed. © 2017 Wiley Periodicals, Inc.

The Impact of Reading Intervention on Brain Responses Underlying Language in Children With Autism.

Science.gov (United States)

Murdaugh, Donna L; Deshpande, Hrishikesh D; Kana, Rajesh K

2016-01-01

Deficits in language comprehension have been widely reported in children with autism spectrum disorders (ASD), with behavioral and neuroimaging studies finding increased reliance on visuospatial processing to aid in language comprehension. However, no study to date, has taken advantage of this strength in visuospatial processing to improve language comprehension difficulties in ASD. This study used a translational neuroimaging approach to test the role of a visual imagery-based reading intervention in improving the brain circuitry underlying language processing in children with ASD. Functional magnetic resonance imaging (MRI), in a longitudinal study design, was used to investigate intervention-related change in sentence comprehension, brain activation, and functional connectivity in three groups of participants (age 8-13 years): an experimental group of ASD children (ASD-EXP), a wait-list control group of ASD children (ASD-WLC), and a group of typically developing control children. After intervention, the ASD-EXP group showed significant increase in activity in visual and language areas and right-hemisphere language area homologues, putamen, and thalamus, suggestive of compensatory routes to increase proficiency in reading comprehension. Additionally, ASD children who had the most improvement in reading comprehension after intervention showed greater functional connectivity between left-hemisphere language areas, the middle temporal gyrus and inferior frontal gyrus while reading high imagery sentences. Thus, the findings of this study, which support the principles of dual coding theory [Paivio 2007], suggest the potential of a strength-based reading intervention in changing brain responses and facilitating better reading comprehension in ASD children. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Disturbance torque rejection properties of the NASA/JPL 70-meter antenna axis servos

Science.gov (United States)

Hill, R. E.

1989-01-01

Analytic methods for evaluating pointing errors caused by external disturbance torques are developed and applied to determine the effects of representative values of wind and friction torque. The expressions relating pointing errors to disturbance torques are shown to be strongly dependent upon the state estimator parameters, as well as upon the state feedback gain and the flow versus pressure characteristics of the hydraulic system. Under certain conditions, when control is derived from an uncorrected estimate of integral position error, the desired type 2 servo properties are not realized and finite steady-state position errors result. Methods for reducing these errors to negligible proportions through the proper selection of control gain and estimator correction parameters are demonstrated. The steady-state error produced by a disturbance torque is found to be directly proportional to the hydraulic internal leakage. This property can be exploited to provide a convenient method of determining system leakage from field measurements of estimator error, axis rate, and hydraulic differential pressure.

Depression Disturbs Germany

Institute of Scientific and Technical Information of China (English)

2011-01-01

The suicide of Robert Enke,the goalkeeper of the Germany national football team who had battled depression for years,stunned the country and cast depression into the national spotlight as a disturbing disease.

Hormonal, electrolyte disturbances and features of hemostasis in term newborn infants of mothers with gestational diabetes mellitus.

Directory of Open Access Journals (Sweden)

Evgeny Viktorovich Mikhalev

2015-03-01

Full Text Available The article reviews the available data on investigations in the field of electrolyte (calcium, magnesium, hormonal (insulin, leptin and hemostasis disturbances in term newborns from women with gestational diabetes; possible mechanisms of their development are also highlighted. The review describes changes in blood glucose concentration in term newborns from women with gestational diabetes, and their impact on the child's condition. In addition to already known factors causing macrosomia and other metabolic disorders in term neonates, the role of leptin (peptide hormone that regulates energy metabolism is quite discussable. Low leptin levels lead to the development of obesity. It is also confirmed, that leptin influences brain development of the newborn, leading to later cognitive deficits in children from women with GDM. The aim of the review is to summarize the available data on investigations in the field of electrolyte (calcium, magnesium, hormonal (insulin, leptin and hemostasis disturbances in term newborns from women with gestational diabetes.

The role of recurrent disturbances for ecosystem multifunctionality.

Science.gov (United States)

Villnäs, Anna; Norkko, Joanna; Hietanen, Susanna; Josefson, Alf B; Lukkari, Kaarina; Norkko, Alf

2013-10-01

Ecosystem functioning is threatened by an increasing number of anthropogenic stressors, creating a legacy of disturbance that undermines ecosystem resilience. However, few empirical studies have assessed to what extent an ecosystem can tolerate repeated disturbances and sustain its multiple functions. By inducing increasingly recurring hypoxic disturbances to a sedimentary ecosystem, we show that the majority of individual ecosystem functions experience gradual degradation patterns in response to repetitive pulse disturbances. The degradation in overall ecosystem functioning was, however, evident at an earlier stage than for single ecosystem functions and was induced after a short pulse of hypoxia (i.e., three days), which likely reduced ecosystem resistance to further hypoxic perturbations. The increasing number of repeated pulse disturbances gradually moved the system closer to a press response. In addition to the disturbance regime, the changes in benthic trait composition as well as habitat heterogeneity were important for explaining the variability in overall ecosystem functioning. Our results suggest that disturbance-induced responses across multiple ecosystem functions can serve as a warning signal for losses of the adaptive capacity of an ecosystem, and might at an early stage provide information to managers and policy makers when remediation efforts should be initiated.

Preface: Impacts of extreme climate events and disturbances on carbon dynamics

Science.gov (United States)

Xiao, Jingfeng; Liu, Shuguang; Stoy, Paul C.

2016-01-01

The impacts of extreme climate events and disturbances (ECE&D) on the carbon cycle have received growing attention in recent years. This special issue showcases a collection of recent advances in understanding the impacts of ECE&D on carbon cycling. Notable advances include quantifying how harvesting activities impact forest structure, carbon pool dynamics, and recovery processes; observed drastic increases of the concentrations of dissolved organic carbon and dissolved methane in thermokarst lakes in western Siberia during a summer warming event; disentangling the roles of herbivores and fire on forest carbon dioxide flux; direct and indirect impacts of fire on the global carbon balance; and improved atmospheric inversion of regional carbon sources and sinks by incorporating disturbances. Combined, studies herein indicate several major research needs. First, disturbances and extreme events can interact with one another, and it is important to understand their overall impacts and also disentangle their effects on the carbon cycle. Second, current ecosystem models are not skillful enough to correctly simulate the underlying processes and impacts of ECE&D (e.g., tree mortality and carbon consequences). Third, benchmark data characterizing the timing, location, type, and magnitude of disturbances must be systematically created to improve our ability to quantify carbon dynamics over large areas. Finally, improving the representation of ECE&D in regional climate/earth system models and accounting for the resulting feedbacks to climate are essential for understanding the interactions between climate and ecosystem dynamics.

Forest Disturbance Mapping Using Dense Synthetic Landsat/MODIS Time-Series and Permutation-Based Disturbance Index Detection

Directory of Open Access Journals (Sweden)

David Frantz

2016-03-01

Full Text Available Spatio-temporal information on process-based forest loss is essential for a wide range of applications. Despite remote sensing being the only feasible means of monitoring forest change at regional or greater scales, there is no retrospectively available remote sensor that meets the demand of monitoring forests with the required spatial detail and guaranteed high temporal frequency. As an alternative, we employed the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM to produce a dense synthetic time series by fusing Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS nadir Bidirectional Reflectance Distribution Function (BRDF adjusted reflectance. Forest loss was detected by applying a multi-temporal disturbance detection approach implementing a Disturbance Index-based detection strategy. The detection thresholds were permutated with random numbers for the normal distribution in order to generate a multi-dimensional threshold confidence area. As a result, a more robust parameterization and a spatially more coherent detection could be achieved. (i The original Landsat time series; (ii synthetic time series; and a (iii combined hybrid approach were used to identify the timing and extent of disturbances. The identified clearings in the Landsat detection were verified using an annual woodland clearing dataset from Queensland’s Statewide Landcover and Trees Study. Disturbances caused by stand-replacing events were successfully identified. The increased temporal resolution of the synthetic time series indicated promising additional information on disturbance timing. The results of the hybrid detection unified the benefits of both approaches, i.e., the spatial quality and general accuracy of the Landsat detection and the increased temporal information of synthetic time series. Results indicated that a temporal improvement in the detection of the disturbance date could be achieved relative to the irregularly spaced Landsat

Substorm-related thermospheric density and wind disturbances derived from CHAMP observations

Directory of Open Access Journals (Sweden)

P. Ritter

2010-06-01

Full Text Available The input of energy and momentum from the magnetosphere is most efficiently coupled into the high latitude ionosphere-thermosphere. The phenomenon we are focusing on here is the magnetospheric substorm. This paper presents substorm related observations of the thermosphere derived from the CHAMP satellite. With its sensitive accelerometer the satellite can measure the air density and zonal winds. Based on a large number of substorm events the average high and low latitude thermospheric response to substorm onsets was deduced. During magnetic substorms the thermospheric density is enhanced first at high latitudes. Then the disturbance travels at an average speed of 650 m/s to lower latitudes, and 3–4 h later the bulge reaches the equator on the night side. Under the influence of the Coriolis force the travelling atmospheric disturbance (TAD is deflected westward. In accordance with present-day atmospheric models the disturbance zonal wind velocities during substorms are close to zero near the equator before midnight and attain moderate westward velocities after midnight. In general, the wind system is only weakly perturbed (Δvy<20 m/s by substorms.

Adaptive control of dynamical synchronization on evolving networks with noise disturbances

Science.gov (United States)

Yuan, Wu-Jie; Zhou, Jian-Fang; Sendiña-Nadal, Irene; Boccaletti, Stefano; Wang, Zhen

2018-02-01

In real-world networked systems, the underlying structure is often affected by external and internal unforeseen factors, making its evolution typically inaccessible. An adaptive strategy was introduced for maintaining synchronization on unpredictably evolving networks [Sorrentino and Ott, Phys. Rev. Lett. 100, 114101 (2008), 10.1103/PhysRevLett.100.114101], which yet does not consider the noise disturbances widely existing in networks' environments. We provide here strategies to control dynamical synchronization on slowly and unpredictably evolving networks subjected to noise disturbances which are observed at the node and at the communication channel level. With our strategy, the nodes' coupling strength is adaptively adjusted with the aim of controlling synchronization, and according only to their received signal and noise disturbances. We first provide a theoretical analysis of the control scheme by introducing an error potential function to seek for the minimization of the synchronization error. Then, we show numerical experiments which verify our theoretical results. In particular, it is found that our adaptive strategy is effective even for the case in which the dynamics of the uncontrolled network would be explosive (i.e., the states of all the nodes would diverge to infinity).

Changes in Soil Fungal Community Structure with Increasing Disturbance Frequency.

Science.gov (United States)

Cho, Hyunjun; Kim, Mincheol; Tripathi, Binu; Adams, Jonathan

2017-07-01

Although disturbance is thought to be important in many ecological processes, responses of fungal communities to soil disturbance have been little studied experimentally. We subjected a soil microcosm to physical disturbance, at a range of frequencies designed to simulate ecological disturbance events. We analyzed the fungal community structure using Illumina HiSeq sequencing of the ITS1 region. Fungal diversity was found to decline with the increasing disturbance frequencies, with no sign of the "humpback" pattern found in many studies of larger sedentary organisms. There is thus no evidence of an effect of release from competition resulting from moderate disturbance-which suggests that competition and niche overlap may not be important in limiting soil fungal diversity. Changing disturbance frequency also led to consistent differences in community composition. There were clear differences in OTU-level composition, with different disturbance treatments each having distinct fungal communities. The functional profile of fungal groups (guilds) was changed by the level of disturbance frequency. These predictable differences in community composition suggest that soil fungi can possess different niches in relation to disturbance frequency, or time since last disturbance. Fungi appear to be most abundant relative to bacteria at intermediate disturbance frequencies, on the time scale we studied here.

Cerebral perfusion and neuropsychological follow up in mild traumatic brain injury : Acute versus chronic disturbances?

NARCIS (Netherlands)

Metting, Zwany; Spikman, Jacoba M.; Rodiger, Lars A.; van der Naalt, Joukje

In a subgroup of patients with mild traumatic brain injury (TBI) residual symptoms, interfering with outcome and return to work, are found. With neuropsychological assessment cognitive deficits can be demonstrated although the pathological underpinnings of these cognitive deficits are not fully

Does sleep disturbance affect the amyloid clearance mechanisms in Alzheimer's disease?

Science.gov (United States)

Yulug, Burak; Hanoglu, Lutfu; Kilic, Ertugrul

2017-10-01

Sleep is an important factor that plays a key role in Alzheimer's disease pathogenesis. However, it is still unclear whether poor-quality sleep may overlap with sleep disturbances in the underlying dysfunctional mechanisms of amyloid beta (Aβ) clearance metabolism. Here, we aimed to evaluate the current evidence on the role of sleep deprivation in Aβ clearance metabolism. To that end, we discuss possible mechanisms underlying the bidirectional interaction between the sleep deprivation and Aβ clearance pathways. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

Structural changes in brain substance in children with epilepsy (MRI findings)

International Nuclear Information System (INIS)

Kaduk, Je.G.

2000-01-01

The structural changes in the brain substance and the parameters of liquor-containing spaces in children with epilepsy are studied. Structural morphological changes in the brain were found in 30, 7 % of cases. In 27, 7 % MRI findings did not differ from the control. The number of porencephalic changes in the both groups was similar (4, 2 - 4, 3 % of cases). Hypotrophy of cortical and subcortical structures, dysgenesis of the colossal body were observed in the group of local epilepsy. Typodense changes of pervantricular structures were more frequent in the patients will local disease. Hypodense changes of the periventricular structures were more frequent in the patients with local disturbances