Regional effects of streptozotocin-induced diabetes on shortening and calcium transport in epicardial and endocardial myocytes from rat left ventricle.

PubMed

Smail, Manal M A; Qureshi, Muhammad A; Shmygol, Anatoliy; Oz, Murat; Singh, Jaipaul; Sydorenko, Vadym; Arabi, Alya; Howarth, Frank C; Al Kury, Lina

2016-11-01

In the heart, the left ventricle pumps blood at higher pressure than the right ventricle. Within the left ventricle, the electromechanical properties of ventricular cardiac myocytes vary transmurally and this may be related to the gradients of stress and strain experienced in vivo across the ventricular wall. Diabetes is also associated with alterations in hemodynamic function. The aim of this study was to investigate shortening and Ca 2+ transport in epicardial (EPI) and endocardial (ENDO) left ventricular myocytes in the streptozotocin (STZ)-induced diabetic rat. Shortening, intracellular Ca 2+ and L-type Ca 2+ current (I Ca,L ) were measured by video detection, fura-2 microfluorimetry, and whole-cell patch clamp techniques, respectively. Time to peak (TPK) shortening was prolonged to similar extents in ENDO and EPI myocytes from STZ-treated rats compared to ENDO and EPI myocytes from controls. Time to half (THALF) relaxation of shortening was prolonged in ENDO myocytes from STZ-treated rats compared to ENDO controls. TPK Ca 2+ transient was prolonged in ENDO myocytes from STZ-treated rats compared to ENDO controls. THALF decay of the Ca 2+ transient was prolonged in ENDO myocytes from STZ-treated rats compared to ENDO controls. Sarcoplasmic reticulum (SR) fractional release of Ca 2+ was reduced in EPI myocytes from STZ-treated rats compared to EPI controls. I C a,L activation, inactivation, and recovery from inactivation were not significantly altered in EPI and ENDO myocytes from STZ-treated rats or controls. Regional differences in Ca 2+ transport may partly underlie differences in ventricular myocyte shortening across the wall of the healthy and the STZ-treated rat left ventricle. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

[Intervention among patients with right bundle branch block and left anterior hemiblock. Operatory risk (author's transl)].

PubMed

Coriat, P; Harari, A; Tarot, J P; Ducardonnet, A; Viars, P

1981-01-01

In order to assess the risk of advanced heart block during anesthesia in patients with right bundle branch block and left anterior hemiblock, 35 consecutive patients were monitored throughout the pre-, intra- and postoperative period. As conventional ECG monitoring may only detect advanced atrioventricular block, patients were monitored according to the Holter method which can easily detect even minor changes of atrioventricular conduction namely slight increased PR interval or dropped P wave. All patients were asymptomatic, in normal sinus rhythm without second degree AV block. Surgical procedures were performed under general anesthesia (n = 15) and epidural anesthesia using lidocaine (n = 20). No episode of second or third degree atrioventricular block occurred. The only modifications observed were rare and transient increase of PR, occurring during surgical procedures in 5 patients, always associated with a sinus bradycardia. They immediately regressed at the termination of the sinus bradycardia either spontaneously or following atropine injection, strongly suggesting the responsability of increased vagal tone. Thus general or epidural anesthesia did not compromise infranodal conduction in any of the observed patients. These data indicate that anesthesia can be safely used without prophylactic preoperative insertion of pacemakers in patients with asymptomatic chronic right bundle branch block and left anterior hemi-block.

Forgetting heart break: a fascinating case of transient left ventricular apical ballooning syndrome associated with dissociative amnesia.

PubMed

Toussi, Amir; Bryk, Jodie; Alam, Abdulkader

2014-01-01

Transient left ventricular apical ballooning syndrome (TLVABS), also known as takotsubo cardiomyopathy, is characterized by transient left ventricular dysfunction, electrocardiographic changes, and release of myocardial enzymes that mimic acute myocardial infarction in patients without angiographic evidence of coronary artery disease. Most patients are post-menopausal women and an emotional or physiologic stressor frequently precedes the presentation. Psychogenic or dissociative amnesia is a memory disorder characterized by sudden retrograde memory loss with inability to recall personal information said to occur for a period of time ranging from hours to years after a stressful event. Interestingly, the mechanism of both disorders has been linked to plasma elevation in catecholamines. Here we present the case of a 66-year-old female diagnosed with both TLVABS and dissociative amnesia following the sudden unexpected death of her sister. To our knowledge, this is surprisingly the first report of the co-occurrence of TLVABS and dissociative amnesia, two processes with a potential shared underlying etiology. © 2013.

Two-dimensional aortographic coronary angiography with synchrotron radiation at aortic regurgitation state

NASA Astrophysics Data System (ADS)

Takeda, Tohoru; Umetani, Keiji; Doi, Toshiki; Itai, Yuji; Yu, Quanwen; Akatsuka, Takao

1999-10-01

At aortic regurgitation state, 2D synchrotron radiation (SR) coronary arteriography (CAG) with aortographic contrast injection was examined theoretically and animal experiments were performed to confirm its diagnostic ability. This system consisted of a silicon monocrystal, fluorescent plate, avalanche-type pickup tube camera, and image acquisition system. The experiment was performed at synchrotron sources in the Photon Factory of Tsukuba. The x- ray energy was adjusted to just above the iodine K-edge. Theoretical calculation described that the coronary arteries overlapping on left ventricle could not be demonstrated well with a high signal-to-noise ratio by using the aortographic CAG with SR. The canine coronary arteries without overlap over the left ventricle were demonstrated clearly, however, the image quality appear to be reduced. The coronary artery overlapping over left ventricle could not be demonstrated well, however the transient reduction of left ventricular wall motion was revealed by transient stenotic procedure of left anterior descending coronary artery.

Persistent Left Unilateral Mirror Writing: A Neuropsychological Case Study

ERIC Educational Resources Information Center

Angelillo, Valentina G.; De Lucia, Natascia; Trojano, Luigi; Grossi, Dario

2010-01-01

Mirror writing (MW) is a rare disorder in which a script runs in direction opposite to normal and individual letters are reversed. The disorder generally occurs after left-hemisphere lesions, is transient and is observed on the left hand, whereas usually motor impairments prevent assessment of direction of right handwriting. We describe a…

A Fluent Language Disorder Following Antepartum Left-Hemisphere Brain Injury.

ERIC Educational Resources Information Center

Feldman, Heidi M.; And Others

1992-01-01

This article describes the language development in a left-handed young child with a left middle cerebral artery infarction. Patterns of development observed between 36 and 60 months of age are described as a transient jargon or fluent aphasia possibly resulting from initial reliance on an uninjured right hemisphere. (Author/DB)

Non-invasive detection of language-related prefrontal high gamma band activity with beamforming MEG.

PubMed

Hashimoto, Hiroaki; Hasegawa, Yuka; Araki, Toshihiko; Sugata, Hisato; Yanagisawa, Takufumi; Yorifuji, Shiro; Hirata, Masayuki

2017-10-27

High gamma band (>50 Hz) activity is a key oscillatory phenomenon of brain activation. However, there has not been a non-invasive method established to detect language-related high gamma band activity. We used a 160-channel whole-head magnetoencephalography (MEG) system equipped with superconducting quantum interference device (SQUID) gradiometers to non-invasively investigate neuromagnetic activities during silent reading and verb generation tasks in 15 healthy participants. Individual data were divided into alpha (8-13 Hz), beta (13-25 Hz), low gamma (25-50 Hz), and high gamma (50-100 Hz) bands and analysed with the beamformer method. The time window was consecutively moved. Group analysis was performed to delineate common areas of brain activation. In the verb generation task, transient power increases in the high gamma band appeared in the left middle frontal gyrus (MFG) at the 550-750 ms post-stimulus window. We set a virtual sensor on the left MFG for time-frequency analysis, and high gamma event-related synchronization (ERS) induced by a verb generation task was demonstrated at 650 ms. In contrast, ERS in the high gamma band was not detected in the silent reading task. Thus, our study successfully non-invasively measured language-related prefrontal high gamma band activity.

Treatment with sodium hyaluronate eye drops in a patient who had early-onset bleb leakage after trabeculectomy with mitomycin C

PubMed Central

Sagara, Hideto; Sekiryu, Tetsuju; Noji, Hiroki; Ogasawara, Masashi; Imaizumi, Kimihiro; Yago, Keiko

2015-01-01

We present the case of a 47-year-old man who had bilateral proliferative diabetic retinopathy and neovascular glaucoma. Schirmer I test revealed tear secretions of 5 mm and 3 mm in the right and left eyes, respectively. Tear breakup times in the right and left eyes were 7 and 8 seconds, respectively. The ocular surface staining in both eyes was scored as Grade 1 as per the Oxford scheme. Retinal photocoagulation was performed for correction of the proliferative diabetic retinopathy and rubeosis iridis, which resolved with treatment. However, the intraocular pressure in the left eye could not be adequately controlled. Therefore, trabeculectomy with mitomycin C using limbal-based conjunctival flap was performed. Three hours after the surgery, the patient developed a large and diffuse filtering bleb, but no leakage occurred from the conjunctival scar. However, on the first postoperative day, leakage was noted and the conjunctiva was at the leakage point. The leakage resolved transiently, but recurred the next day. Severe keratoconjunctival epithelial failure was detected, and the patient was administrated 0.1% sodium hyaluronate eye drops six times daily. The epithelial failure improved, and many microcysts were detected on the bleb surface where the epithelial failure improved. The leakage resolved 2 days after initiation of the sodium hyaluronate eye drops. The microcysts disappeared and the bleb surface became smooth 1 month later. PMID:26664245

Treatment with sodium hyaluronate eye drops in a patient who had early-onset bleb leakage after trabeculectomy with mitomycin C.

PubMed

Sagara, Hideto; Sekiryu, Tetsuju; Noji, Hiroki; Ogasawara, Masashi; Imaizumi, Kimihiro; Yago, Keiko

2015-01-01

We present the case of a 47-year-old man who had bilateral proliferative diabetic retinopathy and neovascular glaucoma. Schirmer I test revealed tear secretions of 5 mm and 3 mm in the right and left eyes, respectively. Tear breakup times in the right and left eyes were 7 and 8 seconds, respectively. The ocular surface staining in both eyes was scored as Grade 1 as per the Oxford scheme. Retinal photocoagulation was performed for correction of the proliferative diabetic retinopathy and rubeosis iridis, which resolved with treatment. However, the intraocular pressure in the left eye could not be adequately controlled. Therefore, trabeculectomy with mitomycin C using limbal-based conjunctival flap was performed. Three hours after the surgery, the patient developed a large and diffuse filtering bleb, but no leakage occurred from the conjunctival scar. However, on the first postoperative day, leakage was noted and the conjunctiva was at the leakage point. The leakage resolved transiently, but recurred the next day. Severe keratoconjunctival epithelial failure was detected, and the patient was administrated 0.1% sodium hyaluronate eye drops six times daily. The epithelial failure improved, and many microcysts were detected on the bleb surface where the epithelial failure improved. The leakage resolved 2 days after initiation of the sodium hyaluronate eye drops. The microcysts disappeared and the bleb surface became smooth 1 month later.

Transient global amnesia: implicit/explicit memory dissociation and PET assessment of brain perfusion and oxygen metabolism in the acute stage.

PubMed

Eustache, F; Desgranges, B; Petit-Taboué, M C; de la Sayette, V; Piot, V; Sablé, C; Marchal, G; Baron, J C

1997-09-01

To assess explicit memory and two components of implicit memory--that is, perceptual-verbal skill learning and lexical-semantic priming effects--as well as resting cerebral blood flow (CBF) and oxygen metabolism (CMRO2) during the acute phase of transient global amnesia. In a 59 year old woman, whose amnestic episode fulfilled all current criteria for transient global amnesia, a neuropsychological protocol was administered, including word learning, story recall, categorical fluency, mirror reading, and word stem completion tasks. PET was performed using the (15)O steady state inhalation method, while the patient still exhibited severe anterograde amnesia and was interleaved with the cognitive tests. There was a clear cut dissociation between impaired long term episodic memory and preserved implicit memory for its two components. Categorical fluency was significantly altered, suggesting word retrieval strategy--rather than semantic memory--impairment. The PET study disclosed a reduced CMRO2 with relatively or fully preserved CBF in the left prefrontotemporal cortex and lentiform nucleus, and the reverse pattern over the left occipital cortex. The PET alterations with patchy CBF-CMRO2 uncoupling would be compatible with a migraine-like phenomenon and indicate that the isolated assessment of perfusion in transient global amnesia may be misleading. The pattern of metabolic depression, with sparing of the hippocampal area, is one among the distinct patterns of brain dysfunction that underlie the (apparently) uniform clinical presentation of transient global amnesia. The finding of a left prefrontal hypometabolism in the face of impaired episodic memory and altered verbal fluency would fit present day concepts from PET activation studies about the role of this area in episodic and semantic memory encoding/retrieval. Likewise, the changes affecting the lenticular nucleus but sparing the caudate would be consistent with the normal performance in perceptual-verbal skill learning. Finally, unaltered lexical-semantic priming effects, despite left temporal cortex hypometabolism, suggest that these processes are subserved by a more distributed neocortical network.

Transient Beneficial Effects of Excitatory Theta Burst Stimulation in a Patient with Phonological Agraphia after Left Supramarginal Gyrus Infarction

ERIC Educational Resources Information Center

Nardone, Raffaele; De Blasi, Pierpaolo; Zuccoli, Giulio; Tezzon, Frediano; Golaszewski, Stefan; Trinka, Eugen

2012-01-01

We report a patient showing isolated phonological agraphia after an ischemic stroke involving the left supramarginal gyrus (SMG). In this patient, we investigated the effects of focal repetitive transcranial magnetic stimulation (rTMS) given as theta burst stimulation (TBS) over the left SMG, corresponding to the Brodmann area (BA) 40. The patient…

Transient spectral domain optical coherence tomography findings in classic MEWDS: a case report.

PubMed

Lavigne, Luciana Castro; Isaac, David Leonardo Cruvinel; Duarte Júnior, José Osório; Avila, Marcos Pereira de

2014-01-01

The purpose of this study was to describe a patient with multiple evanescent white dot syndrome (MEWDS) who presented with classic retinal findings and transient changes in outer retinal anatomy. A 20-year-old man presented with mild blurred vision in the left eye, reporting flu-like symptoms 1 week before the visual symptoms started. Fundus examination of the left eye revealed foveal granularity and multiple scattered spots deep to the retina in the posterior pole. Fluorescein angiography and indocyanine green angiography showed typical MEWDS findings. Spectral Domain Optical Coherence Tomography has shown transient changes in outer retinal anatomy with disappearance of inner segment-outer segment junction and mild attenuation of external limiting membrane. Six months later, Spectral Domain Optical Coherence Tomography has shown complete resolution with recovery of normal outer retinal aspect.

Alterations in left ventricular volumes induced by Valsalva manoeuvre

NASA Technical Reports Server (NTRS)

Brooker, J. Z.; Alderman, E. L.; Harrison, D. C.

1974-01-01

Five patients were studied with left ventriculography during different phases of the Valsalva manoeuvre. Small doses of contrast medium allowed adequate repetitive visualization of the left ventricle for volume calculation. During strain phase, the volume of the left ventricle decreased by nearly 50 per cent in each case, and stroke volume and cardiac output also dropped strikingly. Release of straining was attended by a sharp rebound of left ventricular volume to control levels, with a transient surge of increased cardiac output 42 per cent above that of the resting state.

Real-time detection of transients in OGLE-IV with application of machine learning

NASA Astrophysics Data System (ADS)

Klencki, Jakub; Wyrzykowski, Łukasz

2016-06-01

The current bottleneck of transient detection in most surveys is the problem of rejecting numerous artifacts from detected candidates. We present a triple-stage hierarchical machine learning system for automated artifact filtering in difference imaging, based on self-organizing maps. The classifier, when tested on the OGLE-IV Transient Detection System, accepts 97% of real transients while removing up to 97.5% of artifacts.

Dose-dependent suppression by ethanol of transient auditory 40-Hz response.

PubMed

Jääskeläinen, I P; Hirvonen, J; Saher, M; Pekkonen, E; Sillanaukee, P; Näätänen, R; Tiitinen, H

2000-02-01

Acute alcohol (ethanol) challenge is known to induce various cognitive disturbances, yet the neural basis of the effect is poorly known. The auditory transient evoked gamma-band (40-Hz) oscillatory responses have been suggested to be associated with various perceptual and cognitive functions in humans; however, alcohol effects on auditory 40-Hz responses have not been investigated to date. The objective of the study was to test the dose-related impact of alcohol on auditory transient evoked 40-Hz responses during a selective-attention task. Ten healthy social drinkers ingested, in four separate sessions, 0.00, 0. 25, 0.50, or 0.75 g/kg of 10% (v/v) alcohol solution. The order of the sessions was randomized and a double-blind procedure was employed. During a selective attention task, 300-Hz standard and 330-Hz deviant tones were presented to the left ear, and 1000-Hz standards and 1100-Hz deviants to the right ear of the subjects (P=0. 425 for each standard, P=0.075 for each deviant). The subjects attended to a designated ear, and were to detect the deviants therein while ignoring tones to the other ear. The auditory transient evoked 40-Hz responses elicited by both the attended and unattended standard tones were significantly suppressed by the 0.50 and 0.75 g/kg alcohol doses. Alcohol suppresses auditory transient evoked 40-Hz oscillations already with moderate blood alcohol concentrations. Given the putative role of gamma-band oscillations in cognition, this finding could be associated with certain alcohol-induced cognitive deficits.

Exploring the temporal dynamics of sustained and transient spatial attention using steady-state visual evoked potentials.

PubMed

Zhang, Dan; Hong, Bo; Gao, Shangkai; Röder, Brigitte

2017-05-01

While the behavioral dynamics as well as the functional network of sustained and transient attention have extensively been studied, their underlying neural mechanisms have most often been investigated in separate experiments. In the present study, participants were instructed to perform an audio-visual spatial attention task. They were asked to attend to either the left or the right hemifield and to respond to deviant transient either auditory or visual stimuli. Steady-state visual evoked potentials (SSVEPs) elicited by two task irrelevant pattern reversing checkerboards flickering at 10 and 15 Hz in the left and the right hemifields, respectively, were used to continuously monitor the locus of spatial attention. The amplitude and phase of the SSVEPs were extracted for single trials and were separately analyzed. Sustained attention to one hemifield (spatial attention) as well as to the auditory modality (intermodal attention) increased the inter-trial phase locking of the SSVEP responses, whereas briefly presented visual and auditory stimuli decreased the single-trial SSVEP amplitude between 200 and 500 ms post-stimulus. This transient change of the single-trial amplitude was restricted to the SSVEPs elicited by the reversing checkerboard in the spatially attended hemifield and thus might reflect a transient re-orienting of attention towards the brief stimuli. Thus, the present results demonstrate independent, but interacting neural mechanisms of sustained and transient attentional orienting.

Functional reorganisation in chronic pain and neural correlates of pain sensitisation: A coordinate based meta-analysis of 266 cutaneous pain fMRI studies.

PubMed

Tanasescu, Radu; Cottam, William J; Condon, Laura; Tench, Christopher R; Auer, Dorothee P

2016-09-01

Maladaptive mechanisms of pain processing in chronic pain conditions (CP) are poorly understood. We used coordinate based meta-analysis of 266 fMRI pain studies to study functional brain reorganisation in CP and experimental models of hyperalgesia. The pattern of nociceptive brain activation was similar in CP, hyperalgesia and normalgesia in controls. However, elevated likelihood of activation was detected in the left putamen, left frontal gyrus and right insula in CP comparing stimuli of the most painful vs. other site. Meta-analysis of contrast maps showed no difference between CP, controls, mood conditions. In contrast, experimental hyperalgesia induced stronger activation in the bilateral insula, left cingulate and right frontal gyrus. Activation likelihood maps support a shared neural pain signature of cutaneous nociception in CP and controls. We also present a double dissociation between neural correlates of transient and persistent pain sensitisation with general increased activation intensity but unchanged pattern in experimental hyperalgesia and, by contrast, focally increased activation likelihood, but unchanged intensity, in CP when stimulated at the most painful body part. Copyright © 2016. Published by Elsevier Ltd.

Clinical and electrocardiographic presentations of transient trifascicular block in three cats.

PubMed

Oxford, Eva M; Giacomazzi, Flavia B; Moïse, N Sydney; Santilli, Roberto A

2018-06-01

This report describes transient trifascicular block in three cats presented with lethargy and inappetence, and elevated cardiac troponin I concentrations. The electrocardiogram (ECG) of cat 1 showed a sinus rhythm with pronounced first-degree atrioventricular (AV) block, right bundle branch block, and left anterior fascicular block. The ECG of cat 2 showed truncular left bundle branch block alternating with left anterior fascicular block coupled with prolonged PR intervals, second-degree heart block, and paroxysmal third-degree AV block. The ECG of cat 3 showed first-degree AV block with concomitant right bundle branch block. The diagnosis of trifascicular block was made when paroxysmal third-degree AV block was documented. All cats recovered with medical management within weeks. Each cat resumed a sinus rhythm. Elevated cardiac troponin I concentrations suggested myocarditis that improved. Copyright © 2018 Elsevier B.V. All rights reserved.

[Acute stent thrombosis and reverse transient left ventricular dilatation after performing a single-photon emission computed tomography myocardial perfusion].

PubMed

Miranda, B; Pizzi, M N; Aguadé-Bruix, S; Domingo, E; Candell-Riera, J

2015-01-01

A 63-year-old male patient with a history of stent implantation in the left anterior descending three months before. Due to the presentation of vegetative symptoms, he was referred for gated-SPECT myocardial perfusion. During acquisition of the resting images he presented chest pain and ST segment elevation, so that urgent cardiac catheterization was performed, showing stent thrombosis. Rest perfusion imaging showed a defect in anterior and apical perfusion, more severe and extensive than in the stress images, with striking left ventricular dilatation and a fall in the ejection fraction related to the acute ischemia phenomenon. Intense exercise is associated with a transient activation of the coagulation system and hemodynamic changes that might induce thrombosis, especially in recently implanted coronary stents that probably still have not become completely endothelialized. Copyright © 2014 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

White matter pathways for prosodic structure building: A case study.

PubMed

Sammler, Daniela; Cunitz, Katrin; Gierhan, Sarah M E; Anwander, Alfred; Adermann, Jens; Meixensberger, Jürgen; Friederici, Angela D

2018-05-11

The relevance of left dorsal and ventral fiber pathways for syntactic and semantic comprehension is well established, while pathways for prosody are little explored. The present study examined linguistic prosodic structure building in a patient whose right arcuate/superior longitudinal fascicles and posterior corpus callosum were transiently compromised by a vasogenic peritumoral edema. Compared to ten matched healthy controls, the patient's ability to detect irregular prosodic structure significantly improved between pre- and post-surgical assessment. This recovery was accompanied by an increase in average fractional anisotropy (FA) in right dorsal and posterior transcallosal fiber tracts. Neither general cognitive abilities nor (non-prosodic) syntactic comprehension nor FA in right ventral and left dorsal fiber tracts showed a similar pre-post increase. Together, these findings suggest a contribution of right dorsal and inter-hemispheric pathways to prosody perception, including the right-dorsal tracking and structuring of prosodic pitch contours that is transcallosally informed by concurrent syntactic information. Copyright © 2018 Elsevier Inc. All rights reserved.

The association between acute mental stress and abnormal left atrial electrophysiology.

PubMed

O'Neal, Wesley T; Hammadah, Muhammad; Sandesara, Pratik B; Almuwaqqat, Zakaria; Samman-Tahhan, Ayman; Gafeer, Mohamad M; Abdelhadi, Naser; Wilmot, Kobina; Al Mheid, Ibhar; Bremner, Douglas J; Kutner, Michael; Soliman, Elsayed Z; Shah, Amit J; Quyyumi, Arshed A; Vaccarino, Viola

2017-10-01

Acute stress may trigger atrial fibrillation (AF), but the underlying mechanisms are unclear. We examined if acute mental stress results in abnormal left atrial electrophysiology as detected by more negative deflection of P-wave terminal force in lead V 1 (PTFV 1 ), a well-known marker of AF risk. We examined this hypothesis in 422 patients (mean age = 56 ± 10 years; 61% men; 44% white) with stable coronary heart disease who underwent mental (speech task) stress testing. PTFV 1 was defined as the duration (milliseconds) times the value of the depth (μV) of the downward deflection (terminal portion) of the P-wave in lead V 1 measured on digital electrocardiograms (ECG). Electrocardiographic left atrial abnormality was defined as PTFV 1 ≤ -4000 μV*ms. Mean PTFV 1 values during stress and recovery were compared with rest. The percentage of participants who developed left atrial abnormality during stress and recovery was compared with the percentage at rest. Compared with rest, PTFV 1 became more negative during mental stress (mean change =  -348, 95% CI = [-515, -182]; P < 0.001) and no change was observed at recovery (mean change = 12, 95%CI = [-148, 172]; P = 0.89). A larger percentage of participants showed left atrial abnormality on ECGs obtained at stress (n = 163, 39%) and recovery (n = 142, 34%) compared with rest (n = 127, 30%). Acute mental stress alters left atrial electrophysiology, suggesting that stressful situations promote adverse transient electrical changes to provide the necessary substrate for AF. © 2017 Wiley Periodicals, Inc.

The Neural Bases of Event Monitoring across Domains: a Simultaneous ERP-fMRI Study

PubMed Central

Tarantino, Vincenza; Mazzonetto, Ilaria; Formica, Silvia; Causin, Francesco; Vallesi, Antonino

2017-01-01

The ability to check and evaluate the environment over time with the aim to detect the occurrence of target stimuli is supported by sustained/tonic as well as transient/phasic control processes, which overall might be referred to as event monitoring. The neural underpinning of sustained attentional control processes involves a fronto-parietal network. However, it has not been well-defined yet whether this cortical circuit acts irrespective of the specific material to be monitored and whether this mediates sustained as well as transient monitoring processes. In the current study, the functional activity of brain during an event monitoring task was investigated and compared between two cognitive domains, whose processing is mediated by differently lateralized areas. Namely, participants were asked to monitor sequences of either faces (supported by right-hemisphere regions) or tools (left-hemisphere). In order to disentangle sustained from transient components of monitoring, a simultaneous EEG-fMRI technique was adopted within a block design. When contrasting monitoring versus control blocks, the conventional fMRI analysis revealed the sustained involvement of bilateral fronto-parietal regions, in both task domains. Event-related potentials (ERPs) showed a more positive amplitude over frontal sites in monitoring compared to control blocks, providing evidence of a transient monitoring component. The joint ERP-fMRI analysis showed that, in the case of face monitoring, this transient component relies on right-lateralized areas, including the inferior parietal lobule and the middle frontal gyrus. In the case of tools, no fronto-parietal areas correlated with the transient ERP activity, suggesting that in this domain phasic monitoring processes were masked by tonic ones. Overall, the present findings highlight the role of bilateral fronto-parietal regions in sustained monitoring, independently of the specific task requirements, and suggest that right-lateralized areas subtend transient monitoring processes, at least in some task contexts. PMID:28785212

Impulsive artistic creativity as a presentation of transient cognitive alterations.

PubMed

Finkelstein, Y; Vardi, J; Hod, I

1991-01-01

A 27-year-old right-handed male mosaic artisan who had not shown any interest in drawing or artistic activity was admitted to the Department of Neurology for attacks of bizarre behavior and convulsive disorder. The patient reported feeling "waves" engulfing him during the attacks, leaving him floating helplessly. During some attacks, the patient impulsively initiated drawing activity. Interictal sleep-deprivation EEG showed a left frontotemporal focus of paroxysmal discharge. Brain tomography with SPECT showed low 99Tc-HMPAO uptake in the left frontoparietal region. Psychodiagnostic tests gave evidence of dysfunction of the left frontal region, with preference of the right hemisphere. It is suggested that the attacks of altered cognitive state were, in this case, provoked by spreading depression of the left hemisphere, while the integrative functions of the right hemisphere remained intact. Thus, the impulsive artistic creativity during the attacks may represent a "release phenomenon" of the complex visuospatial skills of the right (subdominant) hemisphere. This symptomatology of transient cognitive alterations is unique and, to the best of our knowledge, has not been previously reported.

Electrical stimulation-based renal nerve mapping exacerbates ventricular arrhythmias during acute myocardial ischaemia.

PubMed

Huang, Bing; Zhou, Xiaoya; Wang, Menglong; Li, Xuefei; Zhou, Liping; Meng, Guannan; Wang, Yuhong; Wang, Zhuo; Wang, Songyun; Yu, Lilei; Jiang, Hong

2018-06-01

Blood pressure elevation in response to transient renal nerve stimulation (RNS) has been used to determine the ablation target and endpoint of renal denervation. This study aimed to evaluate the safety of transient RNS in canines with normal or ischaemic hearts. In ten normal (Group 1) and six healed myocardial infarction (HMI) (Group 2) canines, a large-tip catheter was inserted into the left or right renal artery to perform transient RNS. The left stellate ganglion neural activity (LSGNA) and ventricular electrophysiological parameters were measured at baseline and during transient RNS. In another 20 acute myocardial infarction (AMI) canines, RNS (Group 3, n = 10) or sham RNS (Group 4, n = 10) was intermittently (1 min ON and 4 min OFF) performed for 1 h following AMI induction. The LSGNA and AMI-induced ventricular arrhythmias were analysed. In normal and HMI canines, although transient RNS significantly increased the LSGNA and facilitated the action potential duration (APD) alternans, it did not induce any ventricular arrhythmias and did not change the ventricular effective refractory period, APD or maximum slope of the APD restitution curve. In AMI canines, transient RNS significantly exacerbated LSG activation and promoted the incidence of ventricular arrhythmias. Transient RNS did not increase the risk of ventricular arrhythmias in normal or HMI hearts, but it significantly promoted the occurrence of ventricular arrhythmias in AMI hearts. Therefore, electrical stimulation-based renal nerve mapping may be unsafe in AMI patients and in patients with a high risk for malignant ventricular arrhythmias.

Clinical characteristics and thrombolysis in myocardial infarction frame counts in women with transient left ventricular apical ballooning syndrome.

PubMed

Bybee, Kevin A; Prasad, Abhiram; Barsness, Greg W; Lerman, Amir; Jaffe, Allan S; Murphy, Joseph G; Wright, R Scott; Rihal, Charanjit S

2004-08-01

The characteristics of 16 women with transient left ventricular (LV) apical ballooning syndrome in a United States population are presented. Additionally, Thrombolysis In Myocardial Infarction (TIMI) frame counts were evaluated during the acute period. Patients generally presented with anterior ST-elevation acute coronary syndrome in the absence of obstructive coronary disease. All patients had LV apical wall motion abnormalities. An acute emotional or physiologic stressor preceded most cases. TIMI frame counts were abnormal in all patients and often abnormal in all 3 major coronary vessels, suggesting that the diffuse impairment of coronary microcirculatory function may play a role in the pathogenesis of the syndrome.

Comparison of exercise and pharmacological stress gated SPECT in detecting transient left ventricular dysfunction.

PubMed

Demir, Hakan; Tan, Yusuf Z; Isgoren, Serkan; Gorur, Gozde D; Kozdag, Guliz; Ural, Ertan; Berk, Fatma

2008-06-01

Transient left ventricular contractile dysfunction (TLVD) is observed owing to post-exercise stunning in patients with coronary artery disease (CAD). Pharmacological stimulation differs from exercise stress because it does not cause demand ischemia. The aim of this study was to determine whether TLVD could also be seen after pharmacological stress (dipyridamole). Of the patients in whom gated single-photon emission computed tomography (GSPECT) was performed in our institution from January 2004 to April 2007, 439 subjects with known or suspected CAD were included in the study. GSPECT was performed for all patients following exercise (group I, n = 220) or pharmacological stress (group II, n = 219) according to a 2-day (stress-rest) protocol after injection of Tc-99m methoxyisobutyl-isonitrile (MIBI). Stress, rest, and difference (stress-rest value) left ventricular ejection fractions (SLVEF, RLVEF, and DLVEF) and transient ischemic dilatation (TID) ratio were derived automatically. Summed stress score, summed rest score, and summed difference score (SDS) for myocardial perfusion were calculated using a 20-segment model and a five-point scoring system. An SDS > 3 was considered as ischemic. On the basis of the perfusion findings, patients were subdivided into a normal (group A, n = 216) and ischemia group (group B, n = 223). DLVEF and perfusion scores of all groups were compared. Relationships between DLVEF and perfusion, and between TID ratio and DLVEF were also evaluated. Stress-induced ischemia was observed in 223 of 439 patients (50.8%). In group A, the difference between stress and rest LVEF values was not significant (P = 0.670 and P = 0.200 for groups IA and IIA, respectively). However, LVEF was significantly decreased after stress compared with rest values for group B (P < 0.0001 for groups IB and IIB). TLVD (< or =-5% for DLVEF) was observed in 20 of 216 (9%) and 81 of 223 subjects (36%) in patients in groups A and B, respectively (P < 0.0001). In group I, we found TLVD in 46 of 119 (39%) and 12 of 101 (12%) subjects, in patients with and without ischemia, respectively (P < 0.0001). On the other hand, in group II, TLVD was detected in 35 of 104 (34%) and 8 of 115 (7%) patients with and without ischemia, respectively (P < 0.0001). And also, we found significant good correlations between TID ratios and DLVEF values in four subgroups (r = -0.55, r = -0.62, r = -0.59, and r = -0.41; for groups IA, IB, IIA, and IIB, respectively, P < 0.0001 for all). Dipyridamole is believed to be less likely than exercise to induce ischemia. However, in this study, TLVD after stress was observed following not only exercise but also pharmacological stress, consistent with ischemia.

DETECTION OF FAST RADIO TRANSIENTS WITH MULTIPLE STATIONS: A CASE STUDY USING THE VERY LONG BASELINE ARRAY

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

Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.

2011-07-10

Recent investigations reveal an important new class of transient radio phenomena that occur on submillisecond timescales. Often, transient surveys' data volumes are too large to archive exhaustively. Instead, an online automatic system must excise impulsive interference and detect candidate events in real time. This work presents a case study using data from multiple geographically distributed stations to perform simultaneous interference excision and transient detection. We present several algorithms that incorporate dedispersed data from multiple sites, and report experiments with a commensal real-time transient detection system on the Very Long Baseline Array. We test the system using observations of pulsar B0329+54.more » The multiple-station algorithms enhanced sensitivity for detection of individual pulses. These strategies could improve detection performance for a future generation of geographically distributed arrays such as the Australian Square Kilometre Array Pathfinder and the Square Kilometre Array.« less

An ultrasound transient elastography system with coded excitation.

PubMed

Diao, Xianfen; Zhu, Jing; He, Xiaonian; Chen, Xin; Zhang, Xinyu; Chen, Siping; Liu, Weixiang

2017-06-28

Ultrasound transient elastography technology has found its place in elastography because it is safe and easy to operate. However, it's application in deep tissue is limited. The aim of this study is to design an ultrasound transient elastography system with coded excitation to obtain greater detection depth. The ultrasound transient elastography system requires tissue vibration to be strictly synchronous with ultrasound detection. Therefore, an ultrasound transient elastography system with coded excitation was designed. A central component of this transient elastography system was an arbitrary waveform generator with multi-channel signals output function. This arbitrary waveform generator was used to produce the tissue vibration signal, the ultrasound detection signal and the synchronous triggering signal of the radio frequency data acquisition system. The arbitrary waveform generator can produce different forms of vibration waveform to induce different shear wave propagation in the tissue. Moreover, it can achieve either traditional pulse-echo detection or a phase-modulated or a frequency-modulated coded excitation. A 7-chip Barker code and traditional pulse-echo detection were programmed on the designed ultrasound transient elastography system to detect the shear wave in the phantom excited by the mechanical vibrator. Then an elasticity QA phantom and sixteen in vitro rat livers were used for performance evaluation of the two detection pulses. The elasticity QA phantom's results show that our system is effective, and the rat liver results show the detection depth can be increased more than 1 cm. In addition, the SNR (signal-to-noise ratio) is increased by 15 dB using the 7-chip Barker coded excitation. Applying 7-chip Barker coded excitation technique to the ultrasound transient elastography can increase the detection depth and SNR. Using coded excitation technology to assess the human liver, especially in obese patients, may be a good choice.

Left atrial accessory appendages, diverticula, and left-sided septal pouch in multi-slice computed tomography. Association with atrial fibrillation and cerebrovascular accidents.

PubMed

Hołda, Mateusz K; Koziej, Mateusz; Wszołek, Karolina; Pawlik, Wiesław; Krawczyk-Ożóg, Agata; Sorysz, Danuta; Łoboda, Piotr; Kuźma, Katarzyna; Kuniewicz, Marcin; Lelakowski, Jacek; Dudek, Dariusz; Klimek-Piotrowska, Wiesława

2017-10-01

The aim of this study is to provide a morphometric description of the left-sided septal pouch (LSSP), left atrial accessory appendages, and diverticula using cardiac multi-slice computed tomography (MSCT) and to compare results between patient subgroups. Two hundred and ninety four patients (42.9% females) with a mean of 69.4±13.1years of age were investigated using MSCT. The presence of the LSSP, left atrial accessory appendages, and diverticula was evaluated. Multiple logistic regression analysis was performed to check whether the presence of additional left atrial structures is associated with increased risk of atrial fibrillation and cerebrovascular accidents. At least one additional left atrial structure was present in 51.7% of patients. A single LSSP, left atrial diverticulum, and accessory appendage were present in 35.7%, 16.0%, and 4.1% of patients, respectively. After adjusting for other risk factors via multiple logistic regression, patients with LSSP are more likely to have atrial fibrillation (OR=2.00, 95% CI=1.14-3.48, p=0.01). The presence of a LSSP was found to be associated with an increased risk of transient ischemic attack using multiple logistic regression analysis after adjustment for other risk factors (OR=3.88, 95% CI=1.10-13.69, p=0.03). In conclusion LSSPs, accessory appendages, and diverticula are highly prevalent anatomic structures within the left atrium, which could be easily identified by MSCT. The presence of LSSP is associated with increased risk for atrial fibrillation and transient ischemic attack. Copyright © 2017 Elsevier B.V. All rights reserved.

OGLE-IV Transient Search summary of season 2015b

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Kostrzewa-Rutkowska, Z.; Klencki, J.; Sitek, M.; Mroz, P.; Udalski, A.; Kozlowski, S.; Skowron, J.; Poleski, R.; Szymanski, M. K.; Pietrzynski, G.; Soszynski, I.; Ulaczyk, K.; Pietrukowicz, P.

2015-12-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013) in the 2015b transient observing season (from August) has been operating in dual mode: regular as in previous years (detections every couple of days based on at least two positive detections), and rapid (automatised detections within 15 mins after the single frame was taken, details in Klencki et al. in prep.).

Detection of right-to-left shunts: comparison between the International Consensus and Spencer Logarithmic Scale criteria.

PubMed

Lao, Annabelle Y; Sharma, Vijay K; Tsivgoulis, Georgios; Frey, James L; Malkoff, Marc D; Navarro, Jose C; Alexandrov, Andrei V

2008-10-01

International Consensus Criteria (ICC) consider right-to-left shunt (RLS) present when Transcranial Doppler (TCD) detects even one microbubble (microB). Spencer Logarithmic Scale (SLS) offers more grades of RLS with detection of >30 microB corresponding to a large shunt. We compared the yield of ICC and SLS in detection and quantification of a large RLS. We prospectively evaluated paradoxical embolism in consecutive patients with ischemic strokes or transient ischemic attack (TIA) using injections of 9 cc saline agitated with 1 cc of air. Results were classified according to ICC [negative (no microB), grade I (1-20 microB), grade II (>20 microB or "shower" appearance of microB), and grade III ("curtain" appearance of microB)] and SLS criteria [negative (no microB), grade I (1-10 microB), grade II (11-30 microB), grade III (31100 microB), grade IV (101300 microB), grade V (>300 microB)]. The RLS size was defined as large (>4 mm) using diameter measurement of the septal defects on transesophageal echocardiography (TEE). TCD comparison to TEE showed 24 true positive, 48 true negative, 4 false positive, and 2 false negative cases (sensitivity 92.3%, specificity 92.3%, positive predictive value (PPV) 85.7%, negative predictive value (NPV) 96%, and accuracy 92.3%) for any RLS presence. Both ICC and SLS were 100% sensitive for detection of large RLS. ICC and SLS criteria yielded a false positive rate of 24.4% and 7.7%, respectively when compared to TEE. Although both grading scales provide agreement as to any shunt presence, using the Spencer Scale grade III or higher can decrease by one-half the number of false positive TCD diagnoses to predict large RLS on TEE.

Systemic Hypertension and Transient Ischemic Attack in a 6-Year-Old Girl with Fibromuscular Dysplasia Treated with Percutaneous Angioplasty

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

Foa-Torres, Gustavo; Ganame, Javier, E-mail: javier.ganame@uzleuven.b; Juaneda, Ernesto

We describe a 6-year-old girl with arterial hypertension secondary to fibromuscular dysplasia with stenoses of both renal arteries and transient ischemic attack due to extracranial right internal carotid artery subtotal occlusion as well as left internal carotid artery stenosis. She was treated with percutaneous angioplasty of both renal and both carotid arteries.

Laughter-induced left bundle branch block.

PubMed

Chow, Grant V; Desai, Dipan; Spragg, David D; Zakaria, Sammy

2012-10-01

We present the case of a patient with ischemic heart disease and intermittent left bundle branch block, reproducibly induced by laughter. Following treatment of ischemia with successful deployment of a drug-eluting stent, no further episodes of inducible LBBB were seen. Transient ischemia, exacerbated by elevated intrathoracic pressure during laughter, may have contributed to onset of this phenomenon. © 2012 Wiley Periodicals, Inc.

Perioperative management of calves undergoing implantation of a left ventricular assist device.

PubMed

Wilson, D V; Kantrowitz, A; Pacholewicz, J; Salat, O; Paules, B R; Zhou, Y; Dawe, E J

2000-01-01

To describe perioperative management of calves that underwent left lateral thoracotomy, aortic cross-clamping, partial left heart bypass and implantation of a left ventricular assist device. A total of 43 healthy castrated male calves, weighing 121 +/- 24 kg. Diazepam (mean +/- SD, 0.26 +/- 0.07 mg/kg), ketamine (5.9 +/- 2.17 mg/kg) and isoflurane were used in the anesthetic management of calves undergoing implantation of a left ventricular assist device in the descending thoracic aorta. Other adjunctive agents administered were fentanyl (11 +/- 5.4 microg/kg), lidocaine (4.9 +/- 3.19 mg/kg), bupivacaine (0.75%) and butorphanol (0.49 +/- 0.13 mg/kg). None of the calves regurgitated at induction or during intubation. A tube was used to drain the rumen and prevent bloat during the procedure. Partial left heart bypass was used to perfuse the caudal half of the body during the period of aortic cross clamp and device implantation. Initial mean systemic blood pressure was 96 +/- 25 mm Hg, and pressures measured in the auricular artery increased during aortic cross-clamping and bypass. Vasoconstrictor therapy was required to treat caudal arterial hypotension during the procedure in 9 calves. Mean systemic arterial pressures returned to baseline values by the end of the anesthetic period. Initial mean pulmonary arterial pressures (PAP) were 22 +/- 3 mm Hg. A significant but transient increase in pulmonary arterial pressure occurred after both heparin and protamine administration. The described anesthetic protocol was effective for thoracotomy and implantation of an intra-aortic left ventricular assist device in normal calves. Partial left ventricular bypass was a useful adjunct during the period of aortic cross clamp. The doses of heparin and protamine administered were effective. Responsibility to monitor oxygenation of the cranial half of the animal continues during the bypass period as hypoxemia due to pulmonary dysfunction will not be detected by the perfusionist.

Reduced Sodium Current in the Lateral Ventricular Wall Induces Inferolateral J-Waves.

PubMed

Meijborg, Veronique M F; Potse, Mark; Conrath, Chantal E; Belterman, Charly N W; De Bakker, Jacques M T; Coronel, Ruben

2016-01-01

J-waves in inferolateral leads are associated with a higher risk for idiopathic ventricular fibrillation. We aimed to test potential mechanisms (depolarization or repolarization dependent) responsible for inferolateral J-waves. We hypothesized that inferolateral J-waves can be caused by regional delayed activation of myocardium that is activated late during normal conditions. Computer simulations were performed to evaluate how J-point elevation is influenced by reducing sodium current conductivity (GNa), increasing transient outward current conductivity (Gto), or cellular uncoupling in three predefined ventricular regions (lateral, anterior, or septal). Two pig hearts were Langendorff-perfused with selective perfusion with a sodium channel blocker of lateral or anterior/septal regions. Volume-conducted pseudo-electrocardiograms (ECG) were recorded to detect the presence of J-waves. Epicardial unipolar electrograms were simultaneously recorded to obtain activation times (AT). Simulation data showed that conduction slowing, caused by reduced sodium current, in lateral, but not in other regions induced inferolateral J-waves. An increase in transient outward potassium current or cellular uncoupling in the lateral zone elicited slight J-point elevations which did not meet J-wave criteria. Additional conduction slowing in the entire heart attenuated J-waves and J-point elevations on the ECG, because of masking by the QRS. Experimental data confirmed that conduction slowing attributed to sodium channel blockade in the left lateral but not in the anterior/septal ventricular region induced inferolateral J-waves. J-waves coincided with the delayed activation. Reduced sodium current in the left lateral ventricular myocardium can cause inferolateral J-waves on the ECG.

RFI flagging implications for short-duration transients

NASA Astrophysics Data System (ADS)

Cendes, Y.; Prasad, P.; Rowlinson, A.; Wijers, R. A. M. J.; Swinbank, J. D.; Law, C. J.; van der Horst, A. J.; Carbone, D.; Broderick, J. W.; Staley, T. D.; Stewart, A. J.; Huizinga, F.; Molenaar, G.; Alexov, A.; Bell, M. E.; Coenen, T.; Corbel, S.; Eislöffel, J.; Fender, R.; Grießmeier, J.-M.; Jonker, P.; Kramer, M.; Kuniyoshi, M.; Pietka, M.; Stappers, B.; Wise, M.; Zarka, P.

2018-04-01

With their wide fields of view and often relatively long coverage of any position in the sky in imaging survey mode, modern radio telescopes provide a data stream that is naturally suited to searching for rare transients. However, Radio Frequency Interference (RFI) can show up in the data stream in similar ways to such transients, and thus the normal pre-treatment of filtering RFI (flagging) may also remove astrophysical transients from the data stream before imaging. In this paper we investigate how standard flagging affects the detectability of such transients by examining the case of transient detection in an observing mode used for Low Frequency Array (LOFAR; van Haarlem et al., 2013) surveys. We quantify the fluence range of transients that would be detected, and the reduction of their SNR due to partial flagging. We find that transients with a duration close to the integration sampling time, as well as bright transients with durations on the order of tens of seconds, are completely flagged. For longer transients on the order of several tens of seconds to minutes, the flagging effects are not as severe, although part of the signal is lost. For these transients, we present a modified flagging strategy which mitigates the effect of flagging on transient signals. We also present a script which uses the differences between the two strategies, and known differences between transient RFI and astrophysical transients, to notify the observer when a potential transient is in the data stream.

Gender differences in regional cerebral activity during the perception of emotion: a functional MRI study.

PubMed

Hofer, Alex; Siedentopf, Christian M; Ischebeck, Anja; Rettenbacher, Maria A; Verius, Michael; Felber, Stephan; Fleischhacker, W Wolfgang

2006-08-15

Whether men activate different brain regions during various emotions compared to women or whether gender differences exist in transient emotional states has been the subject of only few studies. We used event-related functional magnetic resonance imaging (fMRI) to investigate gender differences during the perception of positive or negative emotions. The experiment comprised two emotional conditions (pleasant/unpleasant visual stimuli) during which fMRI data were acquired. Altogether, 38 healthy volunteers (19 males, 19 females) were investigated. When subtracting the activation values of men from those of women, suprathreshold positive signal changes were detected in the right posterior cingulate, the left putamen and the left cerebellum during positive mood induction, and in bilateral superior temporal gyri and cerebellar vermis during negative mood induction. The subtraction of activation values of women from those of men yielded no significant differences. Our findings suggest gender-related neural responses to emotional stimuli and could contribute to the understanding of mechanisms underlying gender-related vulnerability of the prevalence and severity of neuropsychiatric disorders.

Neuromodulation therapy does not influence blood flow distribution or left-ventricular dynamics during acute myocardial ischemia.

PubMed

Kingma, J G; Linderoth, B; Ardell, J L; Armour, J A; DeJongste, M J; Foreman, R D

2001-08-13

Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with angina pectoris refractory to conventional therapeutic strategies. The purpose of this study was to determine whether spinal cord stimulation (SCS) in dogs affects regional myocardial blood flow and left-ventricular (LV) function before and during transient obstruction of the left anterior descending coronary artery (LAD). In anesthetized dogs, regional myocardial blood flow distribution was determined using radiolabeled microspheres and left-ventricular function was measured by impedance-derived pressure-volume loops. SCS was accomplished by stimulating the dorsal T1-T2 segments of the spinal cord using epidural bipolar electrodes at 90% of motor threshold (MT) (50 Hz, 0.2-ms duration). Effects of 5-min SCS were assessed under basal conditions and during 4-min occlusion of the LAD. SCS alone evoked no change in regional myocardial blood flow or cardiovascular indices. Transient LAD occlusion significantly diminished blood flow within ischemic, but not in non-ischemic myocardial tissue. Left ventricular pressure-volume loops were shifted rightward during LAD occlusion. Cardiac indices were altered similarly during LAD occlusion and concurrent SCS. SCS does not influence the distribution of blood flow within the non-ischemic or ischemic myocardium. Nor does it modify LV pressure-volume dynamics in the anesthetized experimental preparation.

Pathological laughter as prodromal manifestation of transient ischemic attacks--case report and brief review.

PubMed

Dulamea, Adriana O; Matei, Costel; Mindruta, Ioana; Ionescu, Virgil

2015-10-12

Based on a case report, the authors reviewed the data about involuntary emotional expression disorder (IEED). IEED includes the syndromes of pathological laughing and crying (PLC) and emotional lability (EL). PLC is a rare disorder of emotional expression characterized by relatively uncontrollable episodes of laughter and crying or both that do not have an apparent motivating stimulus. Authors report the case of a 59-year-old man who presented with recurrent episodes of PLC of approximately 2 min duration, consisting of accelerated breathing, emission of guttural, snoring sounds, frowning of the eyebrows, followed by laughter accompanied by motor restlessness of all four limbs. PLC episodes preceded left carotid transient ischemic attacks (TIA's) manifested by reversible aphasia and right hemiparesis. Electroencephalography performed during PLC episodes revealed no spike-wave activity. Brain magnetic resonance imaging showed lacunar infarcts in the left lenticulo-capsulo-thalamic area and multiple round lesions in the cortical-subcortical and in the deep white matter of frontal-parietal-occipital lobes bilaterally, with T2 hyperintensity, T1 isointensity and no diffusion changes. The episodes were interpreted as transient ischemic attacks although gelastic seizures could not be excluded. The etiological investigations revealed unstable plaques on the left carotid artery bulb and the aortic arch and a degenerative mitral valve stenosis. The patient was treated first with antiplatelet therapy and antiepileptic drugs but PLC stopped only after anticoagulation was started. During follow-up the patient continued to have left carotid and vertebrobasilar TIA's being on oral anticoagulation. The patient became asymptomatic only after mitral valve replacement was performed. This case illustrates the difficulty distinguishing between gelastic epilepsy and TIA's in cases of PLC episodes and discuss the neuroanatomic bases and pathophysiology of this rare condition.

Changing axis deviation during acute myocardial infarction.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-07-09

Changing axis deviation has been reported during acute myocardial infarction also associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. We present a case of changing axis deviation in a 70-year-old Italian man with acute myocardial infarction. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Intelligent transient transitions detection of LRE test bed

NASA Astrophysics Data System (ADS)

Zhu, Fengyu; Shen, Zhengguang; Wang, Qi

2013-01-01

Health Monitoring Systems is an implementation of monitoring strategies for complex systems whereby avoiding catastrophic failure, extending life and leading to improved asset management. A Health Monitoring Systems generally encompasses intelligence at many levels and sub-systems including sensors, actuators, devices, etc. In this paper, a smart sensor is studied, which is use to detect transient transitions of liquid-propellant rocket engines test bed. In consideration of dramatic changes of variable condition, wavelet decomposition is used to work real time in areas. Contrast to traditional Fourier transform method, the major advantage of adding wavelet analysis is the ability to detect transient transitions as well as obtaining the frequency content using a much smaller data set. Historically, transient transitions were only detected by offline analysis of the data. The methods proposed in this paper provide an opportunity to detect transient transitions automatically as well as many additional data anomalies, and provide improved data-correction and sensor health diagnostic abilities. The developed algorithms have been tested on actual rocket test data.

Time Domain Astronomy with Fermi GBM in the Multi-messenger Era

NASA Astrophysics Data System (ADS)

Wilson-Hodge, Colleen A.; Fermi GBM team, GBM-LIGO team

2018-01-01

As the Multi-Messenger era begins with detections of gravitational waves with LIGO/Virgo and neutrinos with IceCube, the Fermi Gamma-ray Burst Monitor (GBM) provides context observations of gamma-ray transients between 8 keV and 40 MeV. Fermi GBM has a wide field of view, high uptime, and both in-orbit triggering and high time resolution continuous data enabling offline searches for weaker transients. GBM detects numerous gamma-ray bursts (GRBs), soft gamma-ray repeaters, X-ray bursters, solar flares and terrestrial gamma-ray flashes. Longer timescale transients, predominantly in our galaxy so far, are detected using the Earth occultation technique and epoch-folding for periodic sources. The GBM team has developed two ground-based searches to enhance detections of faint transients, especially short GRBs. The targeted search uses the time and location of an event detected with another instrument to coherently search the GBM data, increasing the sensitivity to a transient. The untargeted search agnostically searches the GBM data for all directions and times to find weaker transients. This search finds about 80 short GRBs per year, adding to the 40 per year triggered on-orbit. With its large field of view, high duty cycle and increasingly sophisticated detection methods, Fermi GBM is expected to have a major role in the Multi-Messenger era.

Induction motor inter turn fault detection using infrared thermographic analysis

NASA Astrophysics Data System (ADS)

Singh, Gurmeet; Anil Kumar, T. Ch.; Naikan, V. N. A.

2016-07-01

Induction motors are the most commonly used prime movers in industries. These are subjected to various environmental, thermal and load stresses that ultimately reduces the motor efficiency and later leads to failure. Inter turn fault is the second most commonly observed faults in the motors and is considered the most severe. It can lead to the failure of complete phase and can even cause accidents, if left undetected or untreated. This paper proposes an online and non invasive technique that uses infrared thermography, in order to detect the presence of inter turn fault in induction motor drive. Two methods have been proposed that detect the fault and estimate its severity. One method uses transient thermal monitoring during the start of motor and other applies pseudo coloring technique on infrared image of the motor, after it reaches a thermal steady state. The designed template for pseudo-coloring is in acquiescence with the InterNational Electrical Testing Association (NETA) thermographic standard. An index is proposed to assess the severity of the fault present in the motor.

Workshop targets development of geodetic transient detection methods: 2009 SCEC Annual Meeting: Workshop on transient anomalous strain detection; Palm Springs, California, 12-13 September 2009

USGS Publications Warehouse

Murray-Moraleda, Jessica R.; Lohman, Rowena

2010-01-01

The Southern California Earthquake Center (SCEC) is a community of researchers at institutions worldwide working to improve understanding of earthquakes and mitigate earthquake risk. One of SCEC's priority objectives is to “develop a geodetic network processing system that will detect anomalous strain transients.” Given the growing number of continuously recording geodetic networks consisting of hundreds of stations, an automated means for systematically searching data for transient signals, especially in near real time, is critical for network operations, hazard monitoring, and event response. The SCEC Transient Detection Test Exercise began in 2008 to foster an active community of researchers working on this problem, explore promising methods, and combine effective approaches in novel ways. A workshop was held in California to assess what has been learned thus far and discuss areas of focus as the project moves forward.

Imaging of underground karst water channels using an improved multichannel transient Rayleigh wave detecting method

PubMed Central

Zheng, Xuhui; Liu, Lei; Li, Gao; Zhou, Fubiao; Xu, Jiemin

2018-01-01

Geological and hydrogeological conditions in karst areas are complicated from the viewpoint of engineering. The construction of underground structures in these areas is often disturbed by the gushing of karst water, which may delay the construction schedule, result in economic losses, and even cause heavy casualties. In this paper, an innovative method of multichannel transient Rayleigh wave detecting is proposed by introducing the concept of arrival time difference phase between channels (TDP). Overcoming the restriction of the space-sampling law, the proposed method can extract the phase velocities of different frequency components from only two channels of transient Rayleigh wave recorded on two adjacent detecting points. This feature greatly improves the work efficiency and lateral resolution of transient Rayleigh wave detecting. The improved multichannel transient Rayleigh wave detecting method is applied to the detection of karst caves and fractures in rock mass of the foundation pit of Yan’an Road Station of Guiyang Metro. The imaging of the detecting results clearly reveals the distribution of karst water inflow channels, which provided significant guidance for water plugging and enabled good control over karst water gushing in the foundation pit. PMID:29883492

Imaging of underground karst water channels using an improved multichannel transient Rayleigh wave detecting method.

PubMed

Zheng, Xuhui; Liu, Lei; Sun, Jinzhong; Li, Gao; Zhou, Fubiao; Xu, Jiemin

2018-01-01

Geological and hydrogeological conditions in karst areas are complicated from the viewpoint of engineering. The construction of underground structures in these areas is often disturbed by the gushing of karst water, which may delay the construction schedule, result in economic losses, and even cause heavy casualties. In this paper, an innovative method of multichannel transient Rayleigh wave detecting is proposed by introducing the concept of arrival time difference phase between channels (TDP). Overcoming the restriction of the space-sampling law, the proposed method can extract the phase velocities of different frequency components from only two channels of transient Rayleigh wave recorded on two adjacent detecting points. This feature greatly improves the work efficiency and lateral resolution of transient Rayleigh wave detecting. The improved multichannel transient Rayleigh wave detecting method is applied to the detection of karst caves and fractures in rock mass of the foundation pit of Yan'an Road Station of Guiyang Metro. The imaging of the detecting results clearly reveals the distribution of karst water inflow channels, which provided significant guidance for water plugging and enabled good control over karst water gushing in the foundation pit.

Segregation by onset asynchrony.

PubMed

Hancock, P J B; Walton, L; Mitchell, G; Plenderleith, Y; Phillips, W A

2008-08-05

We describe a simple psychophysical paradigm for studying figure-ground segregation by onset asynchrony. Two pseudorandom arrays of Gabor patches are displayed, to left and right of fixation. Within one array, a subset of elements form a figure, such as a randomly curving path, that can only be reliably detected when their onset is not synchronized with that of the background elements. Several findings are reported. First, for most participants, segregation required an onset asynchrony of 20-40 ms. Second, detection was no better when the figure was presented first, and thus by itself, than when the background elements were presented first, even though in the latter case the figure could not be detected in either of the two successive displays alone. Third, asynchrony segregated subsets of randomly oriented elements equally well. Fourth, asynchronous onsets aligned with the path could be discriminated from those lying on the path but not aligned with it. Fifth, both transient and sustained neural activity contribute to detection. We argue that these findings are compatible with neural signaling by synchronized rate codes. Finally, schizophrenic disorganization is associated with reduced sensitivity. Thus, in addition to bearing upon basic theoretical issues, this paradigm may have clinical utility.

Exploring methods of cGPS transient detections for the Chilean cGPS network in conjunction with displacement predictions from seismic catalogues: To what extent can we detect seismic and aseismic motion in the cGPS network?

NASA Astrophysics Data System (ADS)

Bedford, J. R.; Moreno, M.; Oncken, O.; Li, S.; Schurr, B.; Metzger, S.; Baez, J. C.; Deng, Z.; Melnick, D.

2016-12-01

Various algorithms for the detection of transient deformation in cGPS networks are under currently being developed to relieve us of by-eye detection, which is an error prone and time-expensive activity. Such algorithms aim to separate the time series into secular, seasonal, and transient components. Additional white and coloured noise, as well as common-mode (network correlated) noise, may remain in the separated transient component of the signal, depending on the processing flow before the separation step. The a-priori knowledge of regional seismicity can assist in the recognition of steps in the data, which are generally corrected for if they are above the noise-floor. Sometimes, the cumulative displacement caused by small earthquakes can create a seemingly continuous transient signal in the cGPS leading to confusion as to whether to attribute this transient motion as seismic or aseismic. Here we demonstrate the efficacy of various transient detection algorithms for subsets of the Chilean cGPS network and present the optimal processing flow for teasing out the transients. We present a step-detection and removal algorithm and estimate the seismic efficiency of any detected transient signals by forward modelling the surface displacements of the earthquakes and comparing to the recovered transient signals. A major challenge in separating signals in the Chilean cGPS network is the overlapping of postseismic effects at adjacent segments: For example, a Mw 9 earthquake will produce a postseismic viscoelastic relaxation that is sustained over decades and several hundreds of kilometres. Additionally, it has been observed in Chile and Japan that following moderately large earthquakes (e.g. Mw > 8) the secular velocities of adjacent segments in the subduction margin suddenly change and remain changed: this effect may be related to a change in speed of slab subduction rather than viscoelastic relaxation, and therefore the signal separation algorithms that assume a time-independent secular velocity at each station may need to be revised to account for this effect. Accordingly, we categorize the recovered separated secular and transient signals of a particular station in terms of the seismic cycle in both its own and adjacent segments and discuss the appropriate modelling strategy for this station given its category.

A Matched Filter Technique for Slow Radio Transient Detection and First Demonstration with the Murchison Widefield Array

NASA Astrophysics Data System (ADS)

Feng, L.; Vaulin, R.; Hewitt, J. N.; Remillard, R.; Kaplan, D. L.; Murphy, Tara; Kudryavtseva, N.; Hancock, P.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Deshpande, A. A.; Gaensler, B. M.; Greenhill, L. J.; Hazelton, B. J.; Johnston-Hollitt, M.; Lonsdale, C. J.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Ord, S. M.; Prabu, T.; Udaya Shankar, N.; Srivani, K. S.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.

2017-03-01

Many astronomical sources produce transient phenomena at radio frequencies, but the transient sky at low frequencies (<300 MHz) remains relatively unexplored. Blind surveys with new wide-field radio instruments are setting increasingly stringent limits on the transient surface density on various timescales. Although many of these instruments are limited by classical confusion noise from an ensemble of faint, unresolved sources, one can in principle detect transients below the classical confusion limit to the extent that the classical confusion noise is independent of time. We develop a technique for detecting radio transients that is based on temporal matched filters applied directly to time series of images, rather than relying on source-finding algorithms applied to individual images. This technique has well-defined statistical properties and is applicable to variable and transient searches for both confusion-limited and non-confusion-limited instruments. Using the Murchison Widefield Array as an example, we demonstrate that the technique works well on real data despite the presence of classical confusion noise, sidelobe confusion noise, and other systematic errors. We searched for transients lasting between 2 minutes and 3 months. We found no transients and set improved upper limits on the transient surface density at 182 MHz for flux densities between ˜20 and 200 mJy, providing the best limits to date for hour- and month-long transients.

OGLE-IV Real-Time Transient Search

NASA Astrophysics Data System (ADS)

Wyrzykowski, Ł.; Kostrzewa-Rutkowska, Z.; Kozłowski, S.; Udalski, A.; Poleski, R.; Skowron, J.; Blagorodnova, N.; Kubiak, M.; Szymański, M. K.; Pietrzyński, G.; Soszyński, I.; Ulaczyk, K.; Pietrukowicz, P.; Mróz, P.

2014-09-01

We present the design and first results of a real-time search for transients within the 650 sq. deg. area around the Magellanic Clouds, conducted as part of the OGLE-IV project and aimed at detecting supernovae, novae and other events. The average sampling of about four days from September to May, yielded a detection of 238 transients in 2012/2013 and 2013/2014 seasons. The superb photometric and astrometric quality of the OGLE data allows for numerous applications of the discovered transients. We use this sample to prepare and train a Machine Learning-based automated classifier for early light curves, which distinguishes major classes of transients with more than 80% of correct answers. Spectroscopically classified 49 supernovae Type Ia are used to construct a Hubble Diagram with statistical scatter of about 0.3 mag and fill the least populated region of the redshifts range in the Union sample. We investigate the influence of host galaxy environments on supernovae statistics and find the mean host extinction of AI=0.19±0.10 mag and AV=0.39±0.21 mag based on a subsample of supernovae Type Ia. We show that the positional accuracy of the survey is of the order of 0.5 pixels (0.13'') and that the OGLE-IV Transient Detection System is capable of detecting transients within the nuclei of galaxies. We present a few interesting cases of nuclear transients of unknown type. All data on the OGLE transients are made publicly available to the astronomical community via the OGLE website.

The Swift/BAT Hard X-ray Transient Monitor: A Status Report

NASA Astrophysics Data System (ADS)

Krimm, Hans A.; Bloom, J. S.; Markwardt, C.; Miler-Jones, J.; Gehrels, N.; Kennea, J. A.; Holland, S.; Sivakoff, G. R.; Swift/BAT Team

2013-04-01

The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. This monitor was first announced at the 2006 HEAD meeting. Seven years later, it continues to operate and provides near real-time light curves of more than 900 astrophysical sources. The BAT observes ~75% of the sky each day with a 3-sigma detection sensitivity of 7 mCrab for a full-day observation and a time resolution as fine as 64 seconds. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of archival light curves spanning nearly seven years. The primary interface for the BAT transient monitor is a public web page. Since February 2005, 223 sources have been detected in the monitor, 142 of them persistent and 81 detected only in outburst. From 2006-2013, fourteen new sources have been discovered by the BAT transient monitor. We will describe the methodology of the transient monitor, present a summary of its statistics, and discuss the detection of known and newly discovered sources.

The Swift/BAT Hard X-ray Transient Monitor: A Status Report

NASA Astrophysics Data System (ADS)

Krimm, Hans A.; Swift/BAT Team

2011-09-01

The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. This monitor was first announced at the 2006 HEAD meeting. Five years later, it continues to operate and provides near real-time light curves of more than 900 astrophysical sources. The BAT observes 75% of the sky each day with a 3-sigma detection sensitivity of 7 mCrab for a full-day observation and a time resolution as fine as 64 seconds. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of archival light curves spanning nearly seven years. The primary interface for the BAT transient monitor is a public web page. Since February 2005, 172 sources have been detected in the monitor, 89 of them persistent and 83 detected only in outburst. From 2006-2011, nine new sources have been discovered by the BAT transient monitor. We will describe the methodology of the transient monitor, present a summary of its statistics, and discuss the detection of known and newly discovered sources.

The Swift/BAT Hard X-ray Transient Monitor

NASA Technical Reports Server (NTRS)

Krimm, H. A.; Holland, S. T.; Corbet, R.H.D.; Pearlman, A. B.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.;

Construction of a High Temporal-spectral Resolution Spectrometer for Detection of Fast Transients from Observations of the Sun at 1.4 GHz.

NASA Astrophysics Data System (ADS)

Casillas-Perez, G. A.; Jeyakumar, S.; Perez-Enriquez, R.

2014-12-01

Transients explosive events with time durations from nanoseconds to several hours, are observed in the Sun at high energy bands such as gamma ray and xray. In the radio band, several types of radio bursts are commonly detected from the ground. A few observations of the Sun in the past have also detected a new class of fast transients which are known to have short-live electromagnetic emissions with durations less than 100 ms. The mechanisms that produce such fast transiets remain unclear. Observations of such fast transients over a wide bandwidth is necessary to uderstand the underlying physical process that produce such fast transients. Due to their very large flux densities, fast radio transients can be observed at high time resolution using small antennas in combination with digital signal processing techniques. In this work we report the progress of an spectrometer that is currently in construction at the Observatorio de la Luz of the Universidad de Guanajuato. The instrument which will have the purpose of detecting solar fast radio transients, involves the use of digital devices such as FPGA and ADC cards, in addition with a receiver with high temporal-spectral resolution centered at 1.4 GHz and a pair of 2.3 m satellite dish.

Transient involuntary mirror writing triggered by anxiety.

PubMed

Della Sala, Sergio; Calia, Clara; De Caro, Maria Fara; McIntosh, Robert D

2015-01-01

Mirror writing (MW) has mainly been observed in left-hemisphere-damaged patients writing with the left hand. This study evaluated the presence of MW in 24 patients with mild cognitive impairment (MCI). We found that MW is not a typical feature of MCI. However, one woman (FC), mislabeled initially with MCI but in fact affected by anxiety, showed florid MW when writing with her left hand, which resolved as her anxiety receded. This case study supports anecdotal reports of MW triggered by anxiety, and the features of FC's performance indicate a motor rather than a perceptual basis for the phenomenon.

An improved ELF/VLF method for globally geolocating sprite-producing lightning

NASA Astrophysics Data System (ADS)

Price, Colin; Asfur, Mustafa; Lyons, Walter; Nelson, Thomas

2002-02-01

The majority of sprites, the most common of transient luminous events (TLEs) in the upper atmosphere, are associated with a sub-class of positive cloud-to-ground lightning flashes (+CGs) whose characteristics are slowly being revealed. These +CGs produce extremely low frequency (ELF) and very low frequency (VLF) radiation detectable at great distances from the parent thunderstorm. During the STEPS field program in the United States, ELF/VLF transients associated with sprites were detected in the Negev Desert, Israel, some 11,000 km away. Within a two-hour period on 4 July 2000, all of the sprites detected optically in the United States produced detectable ELF/VLF transients in Israel. All of these transients were of positive polarity (representing positive lightning). Using the VLF data to obtain the azimuth of the transients, and the ELF data to calculate the distance between the source and receiver, we remotely determined the position of the sprite-forming lightning with an average locational error of 184 km (error of 1.6%).

Fast Neural Dynamics of Proactive Cognitive Control in a Task-Switching Analogue of the Wisconsin Card Sorting Test.

PubMed

Gema Díaz-Blancat; Juan García-Prieto; Fernando Maestú; Francisco Barceló

2018-05-01

One common assumption has been that prefrontal executive control is mostly required for target detection (Posner and Petersen in Ann Rev Neurosci 13:25-42, 1990). Alternatively, cognitive control has also been related to anticipatory updating of task-set (contextual) information, a view that highlights proactive control processes. Frontoparietal cortical networks contribute to both proactive control and reactive target detection, although their fast dynamics are still largely unexplored. To examine this, we analyzed rapid magnetoencephalographic (MEG) source activations elicited by task cues and target cards in a task-cueing analogue of the Wisconsin Card Sorting Test. A single-task (color sorting) condition with equivalent perceptual and motor demands was used as a control. Our results revealed fast, transient and largely switch-specific MEG activations across frontoparietal and cingulo-opercular regions in anticipation of target cards, including (1) early (100-200 ms) cue-locked MEG signals at visual, temporo-parietal and prefrontal cortices of the right hemisphere (i.e., calcarine sulcus, precuneus, inferior frontal gyrus, anterior insula and supramarginal gyrus); and (2) later cue-locked MEG signals at the right anterior and posterior insula (200-300 ms) and the left temporo-parietal junction (300-500 ms). In all cases larger MEG signal intensity was observed in switch relative to repeat cueing conditions. Finally, behavioral restart costs and test scores of working memory capacity (forward digit span) correlated with cue-locked MEG activations at key nodes of the frontoparietal network. Together, our findings suggest that proactive cognitive control of task rule updating can be fast and transiently implemented within less than a second and in anticipation of target detection.

Acute myocardial infarction with changing axis deviation.

PubMed

Patanè, Salvatore; Marte, Filippo

2011-07-01

Changing axis deviation has been rarely reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been rarely reported also during acute myocardial infarction associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. Left anterior hemiblock development during acute inferior myocardial infarction can be an indicator of left anterior descending coronary artery lesions, multivessel coronary artery disease, and impaired left ventricular systolic function. We present a case of changing axis deviation in a 62-year-old Italian man with acute myocardial infarction. Also this case focuses attention on changing axis deviation during acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Literacy shapes thought: the case of event representation in different cultures

PubMed Central

Dobel, Christian; Enriquez-Geppert, Stefanie; Zwitserlood, Pienie; Bölte, Jens

2013-01-01

There has been a lively debate whether conceptual representations of actions or scenes follow a left-to-right spatial transient when participants depict such events or scenes. It was even suggested that conceptualizing the agent on the left side represents a universal. We review the current literature with an emphasis on event representation and on cross-cultural studies. While there is quite some evidence for spatial bias for representations of events and scenes in diverse cultures, their extent and direction depend on task demands, one‘s native language, and importantly, on reading and writing direction. Whether transients arise only in subject-verb-object languages, due to their linear sentential position of event participants, is still an open issue. We investigated a group of illiterate speakers of Yucatec Maya, a language with a predominant verb-object-subject structure. They were compared to illiterate native speakers of Spanish. Neither group displayed a spatial transient. Given the current literature, we argue that learning to read and write has a strong impact on representations of actions and scenes. Thus, while it is still under debate whether language shapes thought, there is firm evidence that literacy does. PMID:24795665

Absence of rotational activity detected using 2-dimensional phase mapping in the corresponding 3-dimensional phase maps in human persistent atrial fibrillation.

PubMed

Pathik, Bhupesh; Kalman, Jonathan M; Walters, Tomos; Kuklik, Pawel; Zhao, Jichao; Madry, Andrew; Sanders, Prashanthan; Kistler, Peter M; Lee, Geoffrey

2018-02-01

Current phase mapping systems for atrial fibrillation create 2-dimensional (2D) maps. This process may affect the accurate detection of rotors. We developed a 3-dimensional (3D) phase mapping technique that uses the 3D locations of basket electrodes to project phase onto patient-specific left atrial 3D surface anatomy. We sought to determine whether rotors detected in 2D phase maps were present at the corresponding time segments and anatomical locations in 3D phase maps. One-minute left atrial atrial fibrillation recordings were obtained in 14 patients using the basket catheter and analyzed off-line. Using the same phase values, 2D and 3D phase maps were created. Analysis involved determining the dominant propagation patterns in 2D phase maps and evaluating the presence of rotors detected in 2D phase maps in the corresponding 3D phase maps. Using 2D phase mapping, the dominant propagation pattern was single wavefront (36.6%) followed by focal activation (34.0%), disorganized activity (23.7%), rotors (3.3%), and multiple wavefronts (2.4%). Ten transient rotors were observed in 9 of 14 patients (64%). The mean rotor duration was 1.1 ± 0.7 seconds. None of the 10 rotors observed in 2D phase maps were seen at the corresponding time segments and anatomical locations in 3D phase maps; 4 of 10 corresponded with single wavefronts in 3D phase maps, 2 of 10 with 2 simultaneous wavefronts, 1 of 10 with disorganized activity, and in 3 of 10 there was no coverage by the basket catheter at the corresponding 3D anatomical location. Rotors detected in 2D phase maps were not observed in the corresponding 3D phase maps. These findings may have implications for current systems that use 2D phase mapping. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

The Swift-BAT Hard X-Ray Transient Monitor

NASA Technical Reports Server (NTRS)

Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.; Pearlman, A. B.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.;

THE SWIFT/BAT HARD X-RAY TRANSIENT MONITOR

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

Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.

2013-11-01

The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as fine as 64 s. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. Themore » primary interface for the BAT transient monitor is a public Web site. Between 2005 February 12 and 2013 April 30, 245 sources have been detected in the monitor, 146 of them persistent and 99 detected only in outburst. Among these sources, 17 were previously unknown and were discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and filtering for the BAT transient monitor and review its sensitivity and exposure. We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries. For the new sources that are previously unpublished, we present basic data analysis and interpretations.« less

Stochastic left-right neuronal asymmetry in Caenorhabditis elegans.

PubMed

Alqadah, Amel; Hsieh, Yi-Wen; Xiong, Rui; Chuang, Chiou-Fen

2016-12-19

Left-right asymmetry in the nervous system is observed across species. Defects in left-right cerebral asymmetry are linked to several neurological diseases, but the molecular mechanisms underlying brain asymmetry in vertebrates are still not very well understood. The Caenorhabditis elegans left and right amphid wing 'C' (AWC) olfactory neurons communicate through intercellular calcium signalling in a transient embryonic gap junction neural network to specify two asymmetric subtypes, AWC OFF (default) and AWC ON (induced), in a stochastic manner. Here, we highlight the molecular mechanisms that establish and maintain stochastic AWC asymmetry. As the components of the AWC asymmetry pathway are highly conserved, insights from the model organism C. elegans may provide a window onto how brain asymmetry develops in humans.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

[Takotsubo syndrome. Transient left ventricular dyskinesia].

PubMed

Pérez Pérez, F M; Sánchez Salado, J

2014-03-01

The Takotsubo syndrome, also called transient apical dyskinesia syndrome, was first described in Japan in the 1990s. It is a rare entity found in almost 1% of all patients with suspicion of acute coronary syndrome. It usually affects postmenopausal women with a few cardiovascular risk factors. It is characterized by angina-type chest pain, electrocardiographic changes, elevation of the enzymes of myocardial injury, absence of coronary obstruction on angiography, and a characteristic left ventricular anteroapical dyskinesia, which returns to normal within a few days. Severe emotional stress is the most common trigger for this syndrome. The aetiopathogenesis of this syndrome remains to be defined. This syndrome has been considered a clinical condition since 2001, when a series of 88 cases was published. It is a disease with a partially known mechanism, characterised by the morphology adopted by the left ventricle secondary to hypokinesis or dyskinesia of the apical segments, and hypercontractility of basal segments. Unlike acute coronary syndrome, patients with left ventricle dysfunction do not have atherothrombotic disease in the coronary arteries. In addition, the alterations described are reversible. Some clinical diagnostic criteria have been proposed, although they are still controversial, as well as in the complementary examinations required for diagnosis. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

Transient left ventricular dysfunction due to coronary spasm after spinal anesthesia with bupivacaine - a case report.

PubMed

Elikowski, Waldemar; Małek-Elikowska, Małgorzata; Słomczyński, Marek; Horbacka, Karolina; Bartkowski, Jarosław; Kalawski, Bartosz

2017-10-23

Bupivacaine is a long-acting local anesthetic (LA) used for cutaneous infiltration, peripheral nerve blocks, epidural and spinal anesthesia. However, its application may result in cardiovascular complications such as: hypotension, bradycardia, cardiac arrest and toxic myocardial injury. The authors describe a 53-year-old male with a history of cigarette smoking, admitted for an elective inguinal hernia surgery. Before surgery, the patient received subarachnoid injection of bupivacaine (20 mg). After the operation, he developed transient hypotension. Blood pressure returned to normal after gelofusine infusion; no sympathomimetics were administered. The male denied chest pain; however, ECG showed ST segment elevation coexisting with left ventricular anterolateral hypokinesia and decreased longitudinal strain in echocardiography. A significant increase in troponin I level was suggestive rather of myocardial infarction than of takotsubo cardiomyopathy. Urgent coronary angiography revealed left anterior descending artery spasm, which remitted after intracoronary nitroglycerin injection. Normalization of ECG and echocardiography was observed within a few days. The authors indicate that the presented atypical adverse effect of bupivacaine manifested itself with delay and that coronary spasm proceeded without angina. A close observation of the patient after anesthetic procedure with LA should be extended over the postoperative period.

Calculating transient rates from surveys

NASA Astrophysics Data System (ADS)

Carbone, D.; van der Horst, A. J.; Wijers, R. A. M. J.; Rowlinson, A.

2017-03-01

We have developed a method to determine the transient surface density and transient rate for any given survey, using Monte Carlo simulations. This method allows us to determine the transient rate as a function of both the flux and the duration of the transients in the whole flux-duration plane rather than one or a few points as currently available methods do. It is applicable to every survey strategy that is monitoring the same part of the sky, regardless the instrument or wavelength of the survey, or the target sources. We have simulated both top-hat and Fast Rise Exponential Decay light curves, highlighting how the shape of the light curve might affect the detectability of transients. Another application for this method is to estimate the number of transients of a given kind that are expected to be detected by a survey, provided that their rate is known.

Decreased Metabolism in the Posterior Medial Network with Concomitantly Increased Metabolism in the Anterior Temporal Network During Transient Global Amnesia.

PubMed

Yi, SangHak; Park, Young Ho; Jang, Jae-Won; Lim, Jae-Sung; Chun, In Kook; Kim, SangYun

2018-05-01

Perturbation of corticohippocampal circuits is a key step in the pathogenesis of transient global amnesia. We evaluated the spatial distribution of altered cerebral metabolism to determine the location of the corticohippocampal circuits perturbed during the acute stage of transient global amnesia. A consecutive series of 12 patients with transient global amnesia who underwent 18 F-fluorodeoxyglucose positron emission tomography within 3 days after symptom onset was identified. We used statistical parametric mapping with two contrasts to identify regions of decreased and increased brain metabolism in transient global amnesia patients compared with 25 age-matched controls. Transient global amnesia patients showed hypometabolic clusters in the left temporal and bilateral parieto-occipital regions that belong to the posterior medial network as well as, hypermetabolic clusters in the bilateral inferior frontal regions that belong to the anterior temporal network. The posterior medial and anterior temporal networks are the two main corticohippocampal circuits involved in memory-guided behavior. Decreased metabolism in the posterior medial network might explain the impairment of episodic memory observed during the acute stage of transient global amnesia. Concomitant increased metabolism within the anterior temporal network might occur as a compensatory mechanism.

Double Neutron Star Mergers and Short Gamma-ray Bursts: Long-lasting High-energy Signatures and Remnant Dichotomy

NASA Astrophysics Data System (ADS)

Murase, Kohta; Toomey, Michael W.; Fang, Ke; Oikonomou, Foteini; Kimura, Shigeo S.; Hotokezaka, Kenta; Kashiyama, Kazumi; Ioka, Kunihito; Mészáros, Peter

2018-02-01

The recent detection of gravitational waves and electromagnetic counterparts from the double neutron star merger event GW+EM170817 supports the standard paradigm of short gamma-ray bursts (SGRBs) and kilonovae/macronovae. It is important to reveal the nature of the compact remnant left after the merger, either a black hole or neutron star, and their physical link to the origin of the long-lasting emission observed in SGRBs. The diversity of the merger remnants may also lead to different kinds of transients that can be detected in future. Here we study the high-energy emission from the long-lasting central engine left after the coalescence, under certain assumptions. In particular, we consider the X-ray emission from a remnant disk and the nonthermal nebular emission from disk-driven outflows or pulsar winds. We demonstrate that late-time X-ray and high-frequency radio emission can provide useful constraints on properties of the hidden compact remnants and their connections to long-lasting SGRB emission, and we discuss the detectability of nearby merger events through late-time observations at ∼30–100 days after the coalescence. We also investigate the GeV–TeV gamma-ray emission that occurs in the presence of long-lasting central engines and show the importance of external inverse Compton radiation due to upscattering of X-ray photons by relativistic electrons in the jet. We also search for high-energy gamma rays from GW170817 in the Fermi-LAT data and report upper limits on such long-lasting emission. Finally, we consider the implications of GW+EM170817 and discuss the constraints placed by X-ray and high-frequency radio observations.

The Volumetric Rate of Calcium-rich Transients in the Local Universe

NASA Astrophysics Data System (ADS)

Frohmaier, Chris; Sullivan, Mark; Maguire, Kate; Nugent, Peter

2018-05-01

We present a measurement of the volumetric rate of “calcium-rich” optical transients in the local universe, using a sample of three events from the Palomar Transient Factory (PTF). This measurement builds on a detailed study of the PTF transient detection efficiencies and uses a Monte Carlo simulation of the PTF survey. We measure the volumetric rate of calcium-rich transients to be higher than previous estimates: {1.21}-0.39+1.13 × {10}-5 events yr‑1 Mpc‑3. This is equivalent to 33%–94% of the local volumetric Type Ia supernova rate. This calcium-rich transient rate is sufficient to reproduce the observed calcium abundances in galaxy clusters, assuming an asymptotic calcium yield per calcium-rich event of ∼0.05 {M}ȯ . We also study the PTF detection efficiency of these transients as a function of position within their candidate host galaxies. We confirm as a real physical effect previous results that suggest that calcium-rich transients prefer large physical offsets from their host galaxies.

Proper Image Subtraction—Optimal Transient Detection, Photometry, and Hypothesis Testing

NASA Astrophysics Data System (ADS)

Zackay, Barak; Ofek, Eran O.; Gal-Yam, Avishay

2016-10-01

Transient detection and flux measurement via image subtraction stand at the base of time domain astronomy. Due to the varying seeing conditions, the image subtraction process is non-trivial, and existing solutions suffer from a variety of problems. Starting from basic statistical principles, we develop the optimal statistic for transient detection, flux measurement, and any image-difference hypothesis testing. We derive a closed-form statistic that: (1) is mathematically proven to be the optimal transient detection statistic in the limit of background-dominated noise, (2) is numerically stable, (3) for accurately registered, adequately sampled images, does not leave subtraction or deconvolution artifacts, (4) allows automatic transient detection to the theoretical sensitivity limit by providing credible detection significance, (5) has uncorrelated white noise, (6) is a sufficient statistic for any further statistical test on the difference image, and, in particular, allows us to distinguish particle hits and other image artifacts from real transients, (7) is symmetric to the exchange of the new and reference images, (8) is at least an order of magnitude faster to compute than some popular methods, and (9) is straightforward to implement. Furthermore, we present extensions of this method that make it resilient to registration errors, color-refraction errors, and any noise source that can be modeled. In addition, we show that the optimal way to prepare a reference image is the proper image coaddition presented in Zackay & Ofek. We demonstrate this method on simulated data and real observations from the PTF data release 2. We provide an implementation of this algorithm in MATLAB and Python.

Maintaining perceptual constancy while remaining vigilant: left hemisphere change blindness and right hemisphere vigilance.

PubMed

Vos, Leia; Whitman, Douglas

2014-01-01

A considerable literature suggests that the right hemisphere is dominant in vigilance for novel and survival-related stimuli, such as predators, across a wide range of species. In contrast to vigilance for change, change blindness is a failure to detect obvious changes in a visual scene when they are obscured by a disruption in scene presentation. We studied lateralised change detection using a series of scenes with salient changes in either the left or right visual fields. In Study 1 left visual field changes were detected more rapidly than right visual field changes, confirming a right hemisphere advantage for change detection. Increasing stimulus difficulty resulted in greater right visual field detections and left hemisphere detection was more likely when change occurred in the right visual field on a prior trial. In Study 2 an intervening distractor task disrupted the influence of prior trials. Again, faster detection speeds were observed for the left visual field changes with a shift to a right visual field advantage with increasing time-to-detection. This suggests that a right hemisphere role for vigilance, or catching attention, and a left hemisphere role for target evaluation, or maintaining attention, is present at the earliest stage of change detection.

Transient Faults in Computer Systems

NASA Technical Reports Server (NTRS)

Masson, Gerald M.

1993-01-01

A powerful technique particularly appropriate for the detection of errors caused by transient faults in computer systems was developed. The technique can be implemented in either software or hardware; the research conducted thus far primarily considered software implementations. The error detection technique developed has the distinct advantage of having provably complete coverage of all errors caused by transient faults that affect the output produced by the execution of a program. In other words, the technique does not have to be tuned to a particular error model to enhance error coverage. Also, the correctness of the technique can be formally verified. The technique uses time and software redundancy. The foundation for an effective, low-overhead, software-based certification trail approach to real-time error detection resulting from transient fault phenomena was developed.

Takotsubo cardiomyopathy in a patient with Addison disease.

PubMed

Punnam, Sujeeth Reddy; Gourineni, Nandu; Gupta, Vishal

2010-10-08

Transient left ventricular apical ballooning syndrome, also known as Takotsubo Cardiomyopathy (Broken Heart Syndrome) is increasingly being reported in the medical literature. Its clinical picture resembles of an acute coronary syndrome with transient apical dyskinesia and normal coronary arteries. We report here a case of Takotsubo cardiomyopathy in a patient with Addison disease with reversible cardiomyopathy. To the best of our knowledge there has been only one other reported case of this syndrome with Addison disease but with a different outcome. Copyright © 2008 Elsevier Ireland Ltd. All rights reserved.

Case of paraneoplastic retinopathy with retinal ON-bipolar cell dysfunction and subsequent resolution of ERGs.

PubMed

Ueno, Shinji; Nakanishi, Ayami; Nishi, Kayo; Suzuki, Shiro; Terasaki, Hiroko

2015-02-01

To report a patient with cancer-associated retinopathy and retinal ON-bipolar cell dysfunction who had a resolution of the electroretinograms (ERGs) after a resection of an ovarian cancer and chemotherapy. A 71-year-old Japanese female patient visited us complaining of night blindness and photopsia in both eyes for 6 months. Her visual acuity was 20/20 in both eyes, and fundus examination, fluorescence angiography, and optical coherence tomography showed no abnormalities in both eyes. The rod responses of the ERGs were absent and bright-flash ERGs were electronegative. The ON responses of the focal macular ERGs and full-field long-flash ERGs were absent. These ERG findings indicate an ON-bipolar cell dysfunction. A general physical examination revealed the presence of ovarian cancer. After resection of the ovarian cancer and adjuvant chemotherapy, the ERGs of the left eye completely recovered within 2 years and those of right eye recovered subsequently. The autoantibody against transient receptor potential melastatin 1 (TRPM1) was not detected in the serum. Our case demonstrates that retinal ON-bipolar dysfunction can be caused by ovarian cancer. Our case indicates that some autoantibodies against other than TRPM1 might cause transient dysfunction of retinal ON-bipolar cells.

Development of an algorithm for automatic detection and rating of squeak and rattle events

NASA Astrophysics Data System (ADS)

Chandrika, Unnikrishnan Kuttan; Kim, Jay H.

2010-10-01

A new algorithm for automatic detection and rating of squeak and rattle (S&R) events was developed. The algorithm utilizes the perceived transient loudness (PTL) that approximates the human perception of a transient noise. At first, instantaneous specific loudness time histories are calculated over 1-24 bark range by applying the analytic wavelet transform and Zwicker loudness transform to the recorded noise. Transient specific loudness time histories are then obtained by removing estimated contributions of the background noise from instantaneous specific loudness time histories. These transient specific loudness time histories are summed to obtain the transient loudness time history. Finally, the PTL time history is obtained by applying Glasberg and Moore temporal integration to the transient loudness time history. Detection of S&R events utilizes the PTL time history obtained by summing only 18-24 barks components to take advantage of high signal-to-noise ratio in the high frequency range. A S&R event is identified when the value of the PTL time history exceeds the detection threshold pre-determined by a jury test. The maximum value of the PTL time history is used for rating of S&R events. Another jury test showed that the method performs much better if the PTL time history obtained by summing all frequency components is used. Therefore, r ating of S&R events utilizes this modified PTL time history. Two additional jury tests were conducted to validate the developed detection and rating methods. The algorithm developed in this work will enable automatic detection and rating of S&R events with good accuracy and minimum possibility of false alarm.

Detecting tidal disruption events of massive black holes in normal galaxies with the Einstein Probe

NASA Astrophysics Data System (ADS)

Yuan, W.; Komossa, S.; Zhang, C.; Feng, H.; Ling, Z.-X.; Zhao, D. H.; Zhang, S.-N.; Osborne, J. P.; O'Brien, P.; Willingale, R.; Lapington, J.

2016-02-01

Stars are tidally disrupted and accreted when they approach massive black holes (MBHs) closely, producing a flare of electromagnetic radiation. The majority of the (approximately two dozen) tidal disruption events (TDEs) identified so far have been discovered by their luminous, transient X-ray emission. Once TDEs are detected in much larger numbers, in future dedicated transient surveys, a wealth of new applications will become possible. Here, we present the proposed Einstein Probe mission, which is a dedicated time-domain soft X-ray all-sky monitor aiming at detecting X-ray transients including TDEs in large numbers. The mission consists of a wide-field micro-pore Lobster-eye imager (60° × 60°), and is designed to carry out an all-sky transient survey at energies of 0.5-4 keV. It will also carry a more sensitive telescope for X-ray follow-ups, and will be capable of issuing public transient alerts rapidly. Einstein Probe is expected to revolutionise the field of TDE research by detecting several tens to hundreds of events per year from the early phase of flares, many with long-term, well sampled lightcurves.

Persistent left unilateral mirror writing: A neuropsychological case study.

PubMed

Angelillo, Valentina G; De Lucia, Natascia; Trojano, Luigi; Grossi, Dario

2010-09-01

Mirror writing (MW) is a rare disorder in which a script runs in direction opposite to normal and individual letters are reversed. The disorder generally occurs after left-hemisphere lesions, is transient and is observed on the left hand, whereas usually motor impairments prevent assessment of direction of right handwriting. We describe a left-handed patient with complete left hand mirror writing, still evident 2 years after a hemorrhagic stroke in left nucleo-capsular region. Since the patient could write with his right hand he underwent several writing tasks with either hand, and a thorough assessment to clarify the nature of MW. MW was evident in writing to dictation with left hand only, both in right and left hemispace, but the patient could modify his behavior when a verbal instruction was provided. No mirror errors were found in reading words, in copying geometric figures and in spatial orientation tasks. MW in our patient could be accounted for by a failure in automatic transformation of grapho-motor programs to write with the left hand. A lack of concern (a sort of anosodiaphoria) and a poor cognitive flexibility could contribute to long-term persistence of MW. 2010 Elsevier Inc. All rights reserved.

Mary, a Pipeline to Aid Discovery of Optical Transients

NASA Astrophysics Data System (ADS)

Andreoni, I.; Jacobs, C.; Hegarty, S.; Pritchard, T.; Cooke, J.; Ryder, S.

2017-09-01

The ability to quickly detect transient sources in optical images and trigger multi-wavelength follow up is key for the discovery of fast transients. These include events rare and difficult to detect such as kilonovae, supernova shock breakout, and `orphan' Gamma-ray Burst afterglows. We present the Mary pipeline, a (mostly) automated tool to discover transients during high-cadenced observations with the Dark Energy Camera at Cerro Tololo Inter-American Observatory (CTIO). The observations are part of the `Deeper Wider Faster' programme, a multi-facility, multi-wavelength programme designed to discover fast transients, including counterparts to Fast Radio Bursts and gravitational waves. Our tests of the Mary pipeline on Dark Energy Camera images return a false positive rate of 2.2% and a missed fraction of 3.4% obtained in less than 2 min, which proves the pipeline to be suitable for rapid and high-quality transient searches. The pipeline can be adapted to search for transients in data obtained with imagers other than Dark Energy Camera.

Changes in left ventricular repolarization and ion channel currents following a transient rate increase superimposed on bradycardia in anesthetized dogs.

PubMed

Rubart, M; Lopshire, J C; Fineberg, N S; Zipes, D P

2000-06-01

We previously demonstrated in dogs that a transient rate increase superimposed on bradycardia causes prolongation of ventricular refractoriness that persists for hours after resumption of bradycardia. In this study, we examined changes in membrane currents that are associated with this phenomenon. The whole cell, patch clamp technique was used to record transmembrane voltages and currents, respectively, in single mid-myocardial left ventricular myocytes from dogs with 1 week of complete AV block; dogs either underwent 1 hour of left ventricular pacing at 120 beats/min or did not undergo pacing. Pacing significantly heightened mean phase 1 and peak plateau amplitudes by approximately 6 and approximately 3 mV, respectively (P < 0.02), and prolonged action potential duration at 90% repolarization from 235+/-8 msec to 278+/-8 msec (1 Hz; P = 0.02). Rapid pacing-induced changes in transmembrane ionic currents included (1) a more pronounced cumulative inactivation of the 4-aminopyridine-sensitive transient outward K+ current, Ito, over the range of physiologic frequencies, resulting from a approximately 30% decrease in the population of quickly reactivating channels; (2) increases in peak density of L-type Ca2+ currents, I(Ca.L), by 15% to 35 % between +10 and +60 mV; and (3) increases in peak density of the Ca2+-activated chloride current, I(Cl.Ca), by 30% to 120% between +30 and +50 mV. Frequency-dependent reduction in Ito combined with enhanced I(Ca.L) causes an increase in net inward current that may be responsible for the observed changes in ventricular repolarization. This augmentation of net cation influx is partially antagonized by an increase in outward I(Ca.Cl).

Bicarbonate refractory QRS prolongation and left bundle-branch block following escitalopram and lamotrigine overdose: A case report and literature review of toxic left bundle-branch block.

PubMed

Farkas, A N; Marcott, M; Yanta, J H; Pizon, A F

2018-05-02

Toxic prolongation of the QRS interval most often results from blockade of cardiac voltage-gated sodium channels and manifests on electrocardiogram with a right bundle-branch block-like morphology. Rarely, a left bundle-branch block (LBBB) morphology has been reported. We report a case of transient LBBB resultant from ingestion of lamotrigine and citalopram which was refractory to sodium bicarbonate therapy and eventually resolved spontaneously. Cases of toxic LBBB are less likely to respond to bicarbonate therapy, suggesting that this finding is due to a mechanism other than sodium channel blockade. © 2018 John Wiley & Sons Ltd.

The Volumetric Rate of Calcium-rich Transients in the Local Universe

DOE PAGES

Frohmaier, Chris; Sullivan, Mark; Maguire, Kate; ...

2018-05-04

Here, we present a measurement of the volumetric rate of "calcium-rich" optical transients in the local universe, using a sample of three events from the Palomar Transient Factory (PTF). This measurement builds on a detailed study of the PTF transient detection efficiencies and uses a Monte Carlo simulation of the PTF survey. We measure the volumetric rate of calcium-rich transients to be higher than previous estimates: 1.21 -0.39 +1.13 10 -5 events yr -1Mpc -3. This is equivalent to 33%-94% of the local volumetric Type Ia supernova rate. This calcium-rich transient rate is sufficient to reproduce the observed calcium abundancesmore » in galaxy clusters, assuming an asymptotic calcium yield per calcium-rich event of ~0.05 M ⊙. As a result, we also study the PTF detection efficiency of these transients as a function of position within their candidate host galaxies. We confirm as a real physical effect previous results that suggest that calcium-rich transients prefer large physical offsets from their host galaxies.« less

The Volumetric Rate of Calcium-rich Transients in the Local Universe

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

Frohmaier, Chris; Sullivan, Mark; Maguire, Kate

Here, we present a measurement of the volumetric rate of "calcium-rich" optical transients in the local universe, using a sample of three events from the Palomar Transient Factory (PTF). This measurement builds on a detailed study of the PTF transient detection efficiencies and uses a Monte Carlo simulation of the PTF survey. We measure the volumetric rate of calcium-rich transients to be higher than previous estimates: 1.21 -0.39 +1.13 10 -5 events yr -1Mpc -3. This is equivalent to 33%-94% of the local volumetric Type Ia supernova rate. This calcium-rich transient rate is sufficient to reproduce the observed calcium abundancesmore » in galaxy clusters, assuming an asymptotic calcium yield per calcium-rich event of ~0.05 M ⊙. As a result, we also study the PTF detection efficiency of these transients as a function of position within their candidate host galaxies. We confirm as a real physical effect previous results that suggest that calcium-rich transients prefer large physical offsets from their host galaxies.« less

The use of transient evoked otoacoustic emissions as a hearing screen following grommet insertion.

PubMed

Dale, O T; McCann, L J; Thio, D; Wells, S C; Drysdale, A J

2011-07-01

This study aimed to evaluate the sensitivity of transient evoked otoacoustic emission testing as a screening tool for hearing loss in children, after grommet insertion. A prospective study was conducted of 48 children (91 ears) aged three to 16 years who had undergone grommet insertion for glue ear. At post-operative review, pure tone audiometry was performed followed by transient evoked otoacoustic emission testing. Outcomes for both tests, in each ear, were compared. The pure tone audiometry threshold was ≤ 20 dB in 85 ears (93.4 per cent), 25 dB in two ears (2.2 per cent) and ≥ 30 dB in four ears (4.4 per cent). Transient evoked otoacoustic emissions were detected in 69 ears (75.8 per cent). The sensitivity of transient evoked otoacoustic emission testing for detecting hearing loss was 100 per cent for ≥ 30 dB loss but only 66.7 per cent for ≥ 25 dB loss. Transient evoked otoacoustic emission testing offers a sensitive means of detecting hearing loss of ≥ 30 dB following grommet insertion in children. However, the use of such testing as a screening tool may miss some cases of mild hearing loss.

The Deep Lens Survey : Real--time Optical Transient and Moving Object Detection

NASA Astrophysics Data System (ADS)

Becker, Andy; Wittman, David; Stubbs, Chris; Dell'Antonio, Ian; Loomba, Dinesh; Schommer, Robert; Tyson, J. Anthony; Margoniner, Vera; DLS Collaboration

2001-12-01

We report on the real-time optical transient program of the Deep Lens Survey (DLS). Meeting the DLS core science weak-lensing objective requires repeated visits to the same part of the sky, 20 visits for 63 sub-fields in 4 filters, on a 4-m telescope. These data are reduced in real-time, and differenced against each other on all available timescales. Our observing strategy is optimized to allow sensitivity to transients on several minute, one day, one month, and one year timescales. The depth of the survey allows us to detect and classify both moving and stationary transients down to ~ 25th magnitude, a relatively unconstrained region of astronomical variability space. All transients and moving objects, including asteroids, Kuiper belt (or trans-Neptunian) objects, variable stars, supernovae, 'unknown' bursts with no apparent host, orphan gamma-ray burst afterglows, as well as airplanes, are posted on the web in real-time for use by the community. We emphasize our sensitivity to detect and respond in real-time to orphan afterglows of gamma-ray bursts, and present one candidate orphan in the field of Abell 1836. See http://dls.bell-labs.com/transients.html.

AN ELDERLY PATIENT WITH ACUTE TRANSIENT OUTER RETINAL DISRUPTION RESEMBLING BILATERAL MULTIPLE EVANESCENT WHITE DOT SYNDROME.

PubMed

Golshani, Cyrus; Gal-Or, Orly; Giovinazzo, Vincent; Freund, K Bailey

2017-11-07

To report an unusual case of an elderly patient with transient outer retinal disruption resembling bilateral multiple evanescent white dot syndrome. Observational case report. Fundus photographs, fluorescein angiography, standard and ultra-widefield fundus autofluorescence, and cross-sectional and en face optical coherence tomography were used to characterize and describe the clinical findings. A 67-year-old woman presented with decreased vision and floaters in her left eye. Best-corrected visual acuity was 20/20-3 in the right eye and 20/80-2 in the left eye. Funduscopic examination showed small deep white dots and foveal granularity of the left eye corresponding to hyperautofluorescent spots on fundus autofluorescence and ellipsoid zone disruption on spectral domain optical coherence tomography. The asymptomatic right eye had evidence of subretinal deposits on spectral domain optical coherence tomography but was otherwise unremarkable. At 4-week follow-up, the patient noted resolution of her symptoms in the left eye but had developed floaters and blurry vision in her right eye. The left eye showed resolving white spots and ellipsoid zone disruption. However, the right eye had new evidence of white spots corresponding to hyperautofluorescent spots on fundus autofluorescence. Spectral domain optical coherence tomography demonstrated subretinal deposits overlying areas of ellipsoid zone disruption. At 8-week follow-up, the patient was asymptomatic in both eyes with best-corrected visual acuity of 20/20 in both eyes. The hyperautofluorescent spots on ultra-widefield fundus autofluorescence had faded with restoration of ellipsoid zone disruption in both eyes and disappearance of subretinal deposits. Our case demonstrates multimodal retinal imaging findings resembling multiple evanescent white dot syndrome in an elderly patient. The bilateral presentation, presence of subretinal deposits before symptom onset, and older age of the patient were atypical features for this entity.

Transient versus Permanent Congenital Hypothyroidism after the Age of 3 Years in Infants Detected on the First versus Second Newborn Screening Test in Oregon, USA.

PubMed

Ford, George A; Denniston, Sara; Sesser, David; Skeels, Michael R; LaFranchi, Stephen H

2016-01-01

The newborn screening (NBS) program in Oregon, USA, collects two routine specimens in all infants. The aim of our study was to determine the incidence of permanent versus transient congenital hypothyroidism (CH) in infants detected on the first versus second screening test. Thyroid function was determined in infants after the age of 3 years diagnosed with CH and born in Oregon between 2005 and 2011. Permanent hypothyroidism was defined as a TSH rise >10 mIU/ml after the first year on treatment or a TSH rise >6 mIU/ml with temporary discontinuation of l-thyroxine after the age of 3 years. Of the cases detected on the first test, 72 of 87 (83%) were permanent and 15 of 87 (17%) were transient, while of the cases detected on the second test, 5 of 22 (23%) were permanent and 17 of 22 (77%) were transient (OR 16.3, p < 0.001). There was a female preponderance detected on the first screen versus a male preponderance on the second screen. Blood spot and serum thyroid function tests at diagnosis, before treatment, were not meaningfully different between the two groups. The mean l-thyroxine dose at the age of 3 years was greater on the first screen: 61.2 versus 36.6 μg/day. Infants detected on the second NBS specimen have a higher incidence of transient CH. © 2016 S. Karger AG, Basel.

Total coliform and E. coli in public water systems using undisinfected ground water in the United States.

PubMed

Messner, Michael J; Berger, Philip; Javier, Julie

2017-06-01

Public water systems (PWSs) in the United States generate total coliform (TC) and Escherichia coli (EC) monitoring data, as required by the Total Coliform Rule (TCR). We analyzed data generated in 2011 by approximately 38,000 small (serving fewer than 4101 individuals) undisinfected public water systems (PWSs). We used statistical modeling to characterize a distribution of TC detection probabilities for each of nine groupings of PWSs based on system type (community, non-transient non-community, and transient non-community) and population served (less than 101, 101-1000 and 1001-4100 people). We found that among PWS types sampled in 2011, on average, undisinfected transient PWSs test positive for TC 4.3% of the time as compared with 3% for undisinfected non-transient PWSs and 2.5% for undisinfected community PWSs. Within each type of PWS, the smaller systems have higher median TC detection than the larger systems. All TC-positive samples were assayed for EC. Among TC-positive samples from small undisinfected PWSs, EC is detected in about 5% of samples, regardless of PWS type or size. We evaluated the upper tail of the TC detection probability distributions and found that significant percentages of some system types have high TC detection probabilities. For example, assuming the systems providing data are nationally-representative, then 5.0% of the ∼50,000 small undisinfected transient PWSs in the U.S. have TC detection probabilities of 20% or more. Communities with such high TC detection probabilities may have elevated risk of acute gastrointestinal (AGI) illness - perhaps as great or greater than the attributable risk to drinking water (6-22%) calculated for 14 Wisconsin community PWSs with much lower TC detection probabilities (about 2.3%, Borchardt et al., 2012). Published by Elsevier GmbH.

Apparatus and method for transient thermal infrared emission spectrometry

DOEpatents

McClelland, John F.; Jones, Roger W.

1991-12-24

A method and apparatus for enabling analysis of a solid material (16, 42) by applying energy from an energy source (20, 70) top a surface region of the solid material sufficient to cause transient heating in a thin surface layer portion of the solid material (16, 42) so as to enable transient thermal emission of infrared radiation from the thin surface layer portion, and by detecting with a spectrometer/detector (28, 58) substantially only the transient thermal emission of infrared radiation from the thin surface layer portion of the solid material. The detected transient thermal emission of infrared radiation is sufficiently free of self-absorption by the solid material of emitted infrared radiation, so as to be indicative of characteristics relating to molecular composition of the solid material.

Real-time detection of optical transients with RAPTOR

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

Borozdin, K. N.; Brumby, Steven P.; Galassi, M. C.

2002-01-01

Fast variability of optical objects is an interesting though poorly explored subject in modern astronomy. Real-time data processing and identification of transient, celestial events in the images is very important, for such study as it allows rapid follow-up with more sensitive instruments, We discuss an approach which we have chosen for the RAPTOR project which is a pioneering close-loop system combining real-time transient detection with rapid follow-up. Our data processing pipeline is able to identify and localize an optical transient within seconds after the observation. We describe the challenges we met, solutions we found and some results obtained in ourmore » search for fast optical transients. The software pipeline we have developed for RAPTOR can easily be applied to the data from other experiments.« less

SEA0400 fails to alter the magnitude of intracellular Ca2+ transients and contractions in Langendorff-perfused guinea pig heart.

PubMed

Szentandrássy, Norbert; Birinyi, Péter; Szigeti, Gyula; Farkas, Attila; Magyar, János; Tóth, András; Csernoch, László; Varró, András; Nánási, Péter P

2008-07-01

SEA0400 is a recently developed inhibitor of the Na+/Ca2+ exchanger (NCX) shown to suppress both forward and reverse mode operation of NCX. Present experiments were designed to study the effect of partial blockade of NCX on Ca handling and contractility in Langendorff-perfused guinea pig hearts loaded with the fluorescent Ca-sensitive dye fura-2. Left ventricular pressure and intracellular calcium concentration ([Ca2+]i) were synchronously recorded before and after cumulative superfusion with 0.3 and 1 muM SEA0400. SEA0400 caused no significant change in the systolic and diastolic values of left ventricular pressure and [Ca2+]i. Accordingly, pulse pressure and amplitude of the [Ca2+]i transient also remained unchanged in the presence of SEA0400. SEA0400 had no influence either on the time required to reach peak values of pressure and [Ca2+)]i or on half relaxation time. On the other hand, both 0.3 and 1 microM SEA0400 significantly increased the decay time constant of [Ca2+]i transients, obtained by fitting its descending limb between 30% and 90% of relaxation, from 127 +/- 7 to 165 +/- 7 and 177 +/- 14 ms, respectively (P < 0.05, n=6). In contrast to the guinea pig hearts, rat hearts responded to SEA0400 treatment with increased [Ca2+]i transients and contractility. These interspecies differences observed in the effect of SEA0400 can be explained by the known differences in calcium handling between the two species.

OGLE-IV Transient Search report 31 December 2016, part 1

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Hamanowicz, A.; Kostrzewa-Rutkowska, Z.; Klencki, J.; Sitek, M.; Udalski, A.; Kozlowski, S.; Ulaczyk, K.; Soszynski, I.; Mroz, P.; Szymanski, M. K.; Poleski, R.; Pietrukowicz, P.; Pawlak, M.; Skowron, J.

2016-12-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013; Klencki et al. 2016, AcA, 66,15) announces discovery of 52 transients discovered in last three months.

OGLE-IV Transient Search report 31 December 2016, part 2

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Hamanowicz, A.; Kostrzewa-Rutkowska, Z.; Klencki, J.; Sitek, M.; Udalski, A.; Kozlowski, S.; Ulaczyk, K.; Soszynski, I.; Mroz, P.; Szymanski, M. K.; Poleski, R.; Pietrukowicz, P.; Pawlak, M.; Skowron, J.

2016-12-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013; Klencki et al. 2016, AcA, 66,15) announces discovery of 46 transients discovered in last three months.

Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome).

PubMed

Maciel, Bruno Araújo; Cidrão, Alan Alves de Lima; Sousa, Italo Bruno Dos Santos; Ferreira, José Adailson da Silva; Messias Neto, Valdevino Pedro

2013-03-01

Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concentrations were increased. Acute myocardial infarction without ST segment elevation was suspected, and coronary angiography was immediately performed, which showed severe diffuse left ventricular hypokinesia, medial-apical systolic ballooning, and a lack of significant coronary injury. The patient was referred to the intensive care unit and was successfully treated with supportive therapy. As this case shows, Takotsubo syndrome might simulate the clinical manifestations of acute myocardial infarction, and coronary angiography is necessary to distinguish between both myocardial infarction and myocardial infarction in the acute stage. The present patient progressed with spontaneous resolution of the ventricular dysfunction without any sequelae.

Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome)

PubMed Central

Maciel, Bruno Araújo; Cidrão, Alan Alves de Lima; Sousa, Ítalo Bruno dos Santos; Ferreira, José Adailson da Silva; Messias Neto, Valdevino Pedro

2013-01-01

Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concentrations were increased. Acute myocardial infarction without ST segment elevation was suspected, and coronary angiography was immediately performed, which showed severe diffuse left ventricular hypokinesia, medial-apical systolic ballooning, and a lack of significant coronary injury. The patient was referred to the intensive care unit and was successfully treated with supportive therapy. As this case shows, Takotsubo syndrome might simulate the clinical manifestations of acute myocardial infarction, and coronary angiography is necessary to distinguish between both myocardial infarction and myocardial infarction in the acute stage. The present patient progressed with spontaneous resolution of the ventricular dysfunction without any sequelae. PMID:23887762

Revealing transient strain in geodetic data with Gaussian process regression

NASA Astrophysics Data System (ADS)

Hines, T. T.; Hetland, E. A.

2018-03-01

Transient strain derived from global navigation satellite system (GNSS) data can be used to detect and understand geophysical processes such as slow slip events and post-seismic deformation. Here we propose using Gaussian process regression (GPR) as a tool for estimating transient strain from GNSS data. GPR is a non-parametric, Bayesian method for interpolating scattered data. In our approach, we assume a stochastic prior model for transient displacements. The prior describes how much we expect transient displacements to covary spatially and temporally. A posterior estimate of transient strain is obtained by differentiating the posterior transient displacements, which are formed by conditioning the prior with the GNSS data. As a demonstration, we use GPR to detect transient strain resulting from slow slip events in the Pacific Northwest. Maximum likelihood methods are used to constrain a prior model for transient displacements in this region. The temporal covariance of our prior model is described by a compact Wendland covariance function, which significantly reduces the computational burden that can be associated with GPR. Our results reveal the spatial and temporal evolution of strain from slow slip events. We verify that the transient strain estimated with GPR is in fact geophysical signal by comparing it to the seismic tremor that is associated with Pacific Northwest slow slip events.

Cilia in vertebrate left-right patterning.

PubMed

Dasgupta, Agnik; Amack, Jeffrey D

2016-12-19

Understanding how left-right (LR) asymmetry is generated in vertebrate embryos is an important problem in developmental biology. In humans, a failure to align the left and right sides of cardiovascular and/or gastrointestinal systems often results in birth defects. Evidence from patients and animal models has implicated cilia in the process of left-right patterning. Here, we review the proposed functions for cilia in establishing LR asymmetry, which include creating transient leftward fluid flows in an embryonic 'left-right organizer'. These flows direct asymmetric activation of a conserved Nodal (TGFβ) signalling pathway that guides asymmetric morphogenesis of developing organs. We discuss the leading hypotheses for how cilia-generated asymmetric fluid flows are translated into asymmetric molecular signals. We also discuss emerging mechanisms that control the subcellular positioning of cilia and the cellular architecture of the left-right organizer, both of which are critical for effective cilia function during left-right patterning. Finally, using mosaic cell-labelling and time-lapse imaging in the zebrafish embryo, we provide new evidence that precursor cells maintain their relative positions as they give rise to the ciliated left-right organizer. This suggests the possibility that these cells acquire left-right positional information prior to the appearance of cilia.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

Cryptogenic embolic stroke in a girl with a trisomy 21 mosaic.

PubMed

Stöllberger, Claudia; Weiss, Simone; Zlabinger, Gerhard; Finsterer, Josef

2012-06-01

Stroke in trisomy 21 may be due to cardioembolism, atherosclerosis, vasculitis, moyamoya disease, sinus venous thrombosis, internal carotid hypoplasia or infections like endocarditis with septic emboli, meningitis or brain abscess. In rare cases, however, stroke etiology remains unexplained. We present a 19 year old Caucasian girl with trisomy 21 with a 47XX+21 karyotype who suffered at age 11 years from a transient ischemic attack with left hemiparesis, and at age 17 years from an ischemic stroke in the territory of the right cerebral medial artery. She suffered from arterial hypertension, obesity and hypercholesterolemia. Since blood coagulation studies, immunologic parameters, blood cultures, 24-h Holter monitoring, transthoracic and transesophageal echocardiography, magnetic resonance angiography of the extra- and intracranial vessels, thoracic and abdominal aorta and renal arteries did not provide any explanation for the stroke, implantation of a loop recorder is considered in order to detect episodes of clinically silent atrial fibrillation.

Fast computation of the kurtogram for the detection of transient faults

NASA Astrophysics Data System (ADS)

Antoni, Jérôme

2007-01-01

The kurtogram is a fourth-order spectral analysis tool recently introduced for detecting and characterising non-stationarities in a signal. The paradigm relies on the assertion that each type of transient is associated with an optimal (frequency/frequency resolution) dyad { f,Δf} which maximises its kurtosis, and hence its detection. However, the complete exploration of the whole plane ( f,Δf) is a formidable task hardly amenable to on-line industrial applications. In this communication we describe a fast algorithm for computing the kurtogram over a grid that finely samples the ( f,Δf) plane. Its complexity is on the order of N log N, similarly to the FFT. The efficiency of the algorithm is then illustrated on several industrial cases concerned with the detection of incipient transient faults.

Validation of Electromechanical Wave Imaging in a canine model during pacing and sinus rhythm

PubMed Central

Grondin, Julien; Costet, Alexandre; Bunting, Ethan; Gambhir, Alok; Garan, Hasan; Wan, Elaine; Konofagou, Elisa E.

2016-01-01

Background Accurate determination of regional areas of arrhythmic triggers is of key interest to diagnose arrhythmias and optimize their treatment. Electromechanical wave imaging (EWI) is an ultrasound technique that can image the transient deformation in the myocardium following electrical activation and therefore has the potential to detect and characterize location of triggers of arrhythmias. Objectives The objectives of this study are to investigate the relationship between electromechanical and electrical activation of the left-ventricular (LV) endocardial surface during epicardial and endocardial pacing as well as during sinus rhythm and also to investigate the distribution of electromechanical delays. Methods In this study, six canines were investigated. Two external electrodes were sutured onto the epicardial surface of the left ventricle (LV). A 64-electrode basket catheter was inserted through the apex of the LV. Ultrasound channel data were acquired at 2000 frames/s during epicardial and endocardial pacing as well as during sinus rhythm. Electromechanical and electrical activation maps were synchronously obtained from the ultrasound data and the basket catheter respectively. Results The mean correlation coefficient between electromechanical and electrical activation was R=0.81 for epicardial anterior pacing, R=0.79 for epicardial lateral pacing, R=0.69 for endocardial pacing and R=0.56 for sinus rhythm. Conclusions The electromechanical activation sequence determined by EWI follows the electrical activation sequence and more specifically in the case of pacing. This finding is of key interest in the role that EWI can play in the detection of the anatomical source of arrhythmias and the planning of pacing therapies such as cardiovascular resynchronization therapy. PMID:27498277

Change-point detection of induced and natural seismicity

NASA Astrophysics Data System (ADS)

Fiedler, B.; Holschneider, M.; Zoeller, G.; Hainzl, S.

2016-12-01

Earthquake rates are influenced by tectonic stress buildup, earthquake-induced stress changes, and transient aseismic sources. While the first two sources can be well modeled due to the fact that the source is known, transient aseismic processes are more difficult to detect. However, the detection of the associated changes of the earthquake activity is of great interest, because it might help to identify natural aseismic deformation patterns (such as slow slip events) and the occurrence of induced seismicity related to human activities. We develop a Bayesian approach to detect change-points in seismicity data which are modeled by Poisson processes. By means of a Likelihood-Ratio-Test, we proof the significance of the change of the intensity. The model is also extended to spatiotemporal data to detect the area of the transient changes. The method is firstly tested for synthetic data and then applied to observational data from central US and the Bardarbunga volcano in Iceland.

Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus) and Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Middle San Luis Rey River, San Diego County, southern California—2017 data summary

USGS Publications Warehouse

Allen, Lisa D.; Howell, Scarlett L.; Kus, Barbara E.

2018-04-20

We surveyed for Least Bell’s Vireos (LBVI) (Vireo bellii pusillus) and Southwestern Willow Flycatchers (SWFL) (Empidonax traillii extimus) along the San Luis Rey River, between College Boulevard in Oceanside and Interstate 15 in Fallbrook, California (middle San Luis Rey River), in 2017. Surveys were conducted from April 13 to July 11 (LBVI) and from May 16 to July 28 (SWFL). We found 146 LBVI territories, at least 107 of which were occupied by pairs. Five additional transient LBVIs were detected. LBVIs used five different habitat types in the survey area: mixed willow, willow-cottonwood, willow-sycamore, riparian scrub, and upland scrub. Forty-four percent of the LBVIs occurred in habitat characterized as mixed willow and 89 percent of the LBVI territories occurred in areas with greater than 50 percent native plant cover. Of 16 banded LBVIs detected in the survey area, 8 had been given full color-band combinations prior to 2017. Four other LBVIs with single (natal) federal bands were recaptured and banded in 2017. Three LBVIs with single dark blue federal bands indicating that they were banded as nestlings on the lower San Luis Rey River and one LBVI with a single gold federal band indicating that it was banded as a nestling on Marine Corps Base Camp Pendleton (MCBCP) could not be recaptured for identification. One banded LBVI emigrated from the middle San Luis Rey River to the lower San Luis Rey River in 2017.One resident SWFL territory and one transient Willow Flycatcher of unknown subspecies (WIFL) were observed in the survey area in 2017. The resident SWFL territory, which was comprised of mixed willow habitat (5–50 percent native plant cover), was occupied by a single male from May 22 to June 21, 2017. No evidence of pairing or nesting activity was observed. The SWFL male was banded with a full color-combination indicating that he was originally banded as a nestling on the middle San Luis Rey River in 2014 and successfully bred in the survey area in 2016. The male SWFL left the middle San Luis Rey River after June 21, 2017 and subsequently was detected on the San Dieguito River on June 26, 2017, by USGS biologists. The transient WIFL was detected on May 30, 2017, in mixed willow habitat comprised of 50–95 percent of native plant cover.

OGLE-IV Transient Search report 25 September 2017 part 2

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Gromadzki, M.; Hamanowicz, A.; Rybicki, K.; Klencki, J.; Kozlowski, S.; Udalski, A.; Poleski, R.; Szymanski, M. K.; Skowron, J.; Ulaczyk, K.; Pawlak, M.; Mroz, P.; Soszynski, I.; Pietrukowicz, P.; Sitek, M.; Ihanec, N.

2017-09-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013; Klencki et al. 2016, AcA, 66,15) announces discovery of 49 new on-going and recently finished transients discovered since Jan 2017.

OGLE-IV Transient Search report 25 September 2017 part 1

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Gromadzki, M.; Hamanowicz, A.; Rybicki, K.; Klencki, J.; Kozlowski, S.; Udalski, A.; Poleski, R.; Szymanski, M. K.; Skowron, J.; Ulaczyk, K.; Pawlak, M.; Mroz, P.; Soszynski, I.; Pietrukowicz, P.; Sitek, M.; Ihanec, N.

2017-09-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013; Klencki et al. 2016, AcA, 66,15) announces discovery of 50 new on-going and recently finished transients discovered since Jan 2017.

AMPLATZER versus Figulla occluder for transcatheter patent foramen ovale closure.

PubMed

Trabattoni, Daniela; Gaspardone, Achille; Sgueglia, Gregory A; Fabbiocchi, Franco; Gioffrè, Gaetano; Montorsi, Piero; Calligaris, Giuseppe; Iamele, Maria; De Santis, Antonella; Bartorelli, Antonio L

2017-04-20

The aim of this observational study was to compare acute and 12-month results of percutaneous closure of patent foramen ovale (PFO) with two occluder devices. Between June 2007 and October 2014, 406 consecutive patients (48.1±13.3 years, 243 women) underwent percutaneous PFO closure with either the AMPLATZER (n=179) or the Figulla (n=227) device after a stroke or a transient ischaemic attack ascribed to the PFO. A right-to-left shunt grade >1 was previously detected in all patients and atrial septal aneurysm was present in 111 (27.5%) patients. Patients were followed up with a contrast transthoracic echocardiogram and clinically at 24 hours, six months, and 12 months after the procedure. A high procedural success was observed in both groups. Despite a trend towards a higher incidence of acute residual shunt immediately after device deployment among Figulla occluder patients, a residual grade ≥2 right-to-left shunt was observed in 4.5% of patients, independently of the device used for PFO closure. The only difference reported after Figulla device implantation was a lower rate of supraventricular arrhythmias (9% vs. 17%, p=0.02). According to this two-centre study, PFO closure appears safe and effective with the Figulla occluder as well as with the AMPLATZER device.

Structural Brain Changes Following Left Temporal Low-Frequency rTMS in Patients with Subjective Tinnitus

PubMed Central

Langguth, Berthold; Poeppl, Timm B.; Rupprecht, Rainer; Hajak, Göran; Landgrebe, Michael; Schecklmann, Martin

2014-01-01

Repetitive transcranial magnetic stimulation (rTMS) of the temporal cortex has been used to treat patients with subjective tinnitus. While rTMS is known to induce morphological changes in healthy subjects, no study has investigated yet whether rTMS treatment induces grey matter (GM) changes in tinnitus patients as well, whether these changes are correlated with treatment success, and whether GM at baseline is a useful predictor for treatment outcome. Therefore, we examined magnetic resonance images of 77 tinnitus patients who were treated with rTMS of the left temporal cortex (10 days, 2000 stimuli/day, 1 Hz). At baseline and after the last treatment session high-resolution structural images of the brain were acquired and tinnitus severity was assessed. For a subgroup of 41 patients, additional brain scans were done after a follow-up period of 90 days. GM changes were analysed by means of voxel based morphometry. Transient GM decreases were detectable in several brain regions, especially in the insula and the inferior frontal cortex. These changes were not related to treatment outcome though. Baseline images correlated with change in tinnitus severity in the frontal cortex and the lingual gyrus, suggesting that GM at baseline might hold potential as a possible predictor for treatment outcome. PMID:24991438

The Rapid Gamma-ray Burst Response Campaign with ROTSE

NASA Astrophysics Data System (ADS)

Balsano, R.; Bloch, J.; Casperson, D.; Fletcher, S.; Gisler, G.; Hills, J.; Priedhorsky, W.; Szymanski, J.; Wren, J.; Akerlof, C.; Kehoe, R.; McKay, T.; Pawl, A.; Marshall, S.; Lee, B.; Barthelmy, S.; Butterworth, P.; Cline, T.

2000-04-01

The main goal of the Robotic Optical Transient Search Experiment (ROTSE) is to detect optical emission from Gamma-ray Bursts (GRBs) during and immediately following GRBs. The instruments comprising ROTSE consist of wide-field optics on rapidly slewing mounts optimized for quick response to GRBs localized to several degree regions. Thus far, only one prompt optical counterpart to a GRB has been discovered although simple scaling arguments suggest more should be easily detected. This talk will cover ROTSE responses to GRBs detected by the Burst and Transient Source Experiment and the soon-to-be-launched High Energy Transient Experiment. The expansion of ROTSE to a global network of identical telescopes will also be briefly discussed.

The role of auditory transient and deviance processing in distraction of task performance: a combined behavioral and event-related brain potential study

PubMed Central

Berti, Stefan

2013-01-01

Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechanism is capable of distracting ongoing task performance. In contrast, it is open whether transient detection—which does not rely on predictive coding mechanisms—can trigger behavioral distraction, too. In the present study, the effect of rare auditory changes on visual task performance is tested in an auditory-visual cross-modal distraction paradigm. The rare changes are either embedded within a continuous standard stimulation (triggering deviance detection) or are presented within an otherwise silent situation (triggering transient detection). In the event-related brain potentials, deviants elicited the mismatch negativity (MMN) while transients elicited an enhanced N1 component, mirroring pre-attentive change detection in both conditions but on the basis of different neuro-cognitive processes. These sensory components are followed by attention related ERP components including the P3a and the reorienting negativity (RON). This demonstrates that both types of changes trigger switches of attention. Finally, distraction of task performance is observable, too, but the impact of deviants is higher compared to transients. These findings suggest different routes of distraction allowing for the automatic processing of a wide range of potentially relevant changes in the environment as a pre-requisite for adaptive behavior. PMID:23874278

Automated transient detection in the STEREO Heliospheric Imagers.

NASA Astrophysics Data System (ADS)

Barnard, Luke; Scott, Chris; Owens, Mat; Lockwood, Mike; Tucker-Hood, Kim; Davies, Jackie

2014-05-01

Since the launch of the twin STEREO satellites, the heliospheric imagers (HI) have been used, with good results, in tracking transients of solar origin, such as Coronal Mass Ejections (CMEs), out far into the heliosphere. A frequently used approach is to build a "J-map", in which multiple elongation profiles along a constant position angle are stacked in time, building an image in which radially propagating transients form curved tracks in the J-map. From this the time-elongation profile of a solar transient can be manually identified. This is a time consuming and laborious process, and the results are subjective, depending on the skill and expertise of the investigator. Therefore, it is desirable to develop an automated algorithm for the detection and tracking of the transient features observed in HI data. This is to some extent previously covered ground, as similar problems have been encountered in the analysis of coronagraph data and have led to the development of products such as CACtus etc. We present the results of our investigation into the automated detection of solar transients observed in J-maps formed from HI data. We use edge and line detection methods to identify transients in the J-maps, and then use kinematic models of the solar transient propagation (such as the fixed-phi and harmonic mean geometric models) to estimate the solar transients properties, such as transient speed and propagation direction, from the time-elongation profile. The effectiveness of this process is assessed by comparison of our results with a set of manually identified CMEs, extracted and analysed by the Solar Storm Watch Project. Solar Storm Watch is a citizen science project in which solar transients are identified in J-maps formed from HI data and tracked multiple times by different users. This allows the calculation of a consensus time-elongation profile for each event, and therefore does not suffer from the potential subjectivity of an individual researcher tracking an event. Furthermore, we present preliminary results regarding the estimation of the ambient solar wind speed from the automated analysis of the HI J-maps, by the tracking of numerous small scale features entrained into the ambient solar wind, which can only be tracked out to small elongations.

Two peculiar fast transients in a strongly lensed host galaxy

NASA Astrophysics Data System (ADS)

Rodney, S. A.; Balestra, I.; Bradac, M.; Brammer, G.; Broadhurst, T.; Caminha, G. B.; Chirivı, G.; Diego, J. M.; Filippenko, A. V.; Foley, R. J.; Graur, O.; Grillo, C.; Hemmati, S.; Hjorth, J.; Hoag, A.; Jauzac, M.; Jha, S. W.; Kawamata, R.; Kelly, P. L.; McCully, C.; Mobasher, B.; Molino, A.; Oguri, M.; Richard, J.; Riess, A. G.; Rosati, P.; Schmidt, K. B.; Selsing, J.; Sharon, K.; Strolger, L.-G.; Suyu, S. H.; Treu, T.; Weiner, B. J.; Williams, L. L. R.; Zitrin, A.

2018-04-01

A massive galaxy cluster can serve as a magnifying glass for distant stellar populations, as strong gravitational lensing magnifies background galaxies and exposes details that are otherwise undetectable. In time-domain astronomy, imaging programmes with a short cadence are able to detect rapidly evolving transients, previously unseen by surveys designed for slowly evolving supernovae. Here, we describe two unusual transient events discovered in a Hubble Space Telescope programme that combined these techniques with high-cadence imaging on a field with a strong-lensing galaxy cluster. These transients were faster and fainter than any supernovae, but substantially more luminous than a classical nova. We find that they can be explained as separate eruptions of a luminous blue variable star or a recurrent nova, or as an unrelated pair of stellar microlensing events. To distinguish between these hypotheses will require clarification of the cluster lens models, along with more high-cadence imaging of the field that could detect related transient episodes. This discovery suggests that the intersection of strong lensing with high-cadence transient surveys may be a fruitful path for future astrophysical transient studies.

Real-time Recovery Efficiencies and Performance of the Palomar Transient Factory’s Transient Discovery Pipeline

NASA Astrophysics Data System (ADS)

Frohmaier, C.; Sullivan, M.; Nugent, P. E.; Goldstein, D. A.; DeRose, J.

2017-05-01

We present the transient source detection efficiencies of the Palomar Transient Factory (PTF), parameterizing the number of transients that PTF found versus the number of similar transients that occurred over the same period in the survey search area but were missed. PTF was an optical sky survey carried out with the Palomar 48 inch telescope over 2009-2012, observing more than 8000 square degrees of sky with cadences of between one and five days, locating around 50,000 non-moving transient sources, and spectroscopically confirming around 1900 supernovae. We assess the effectiveness with which PTF detected transient sources, by inserting ≃ 7 million artificial point sources into real PTF data. We then study the efficiency with which the PTF real-time pipeline recovered these sources as a function of the source magnitude, host galaxy surface brightness, and various observing conditions (using proxies for seeing, sky brightness, and transparency). The product of this study is a multi-dimensional recovery efficiency grid appropriate for the range of observing conditions that PTF experienced and that can then be used for studies of the rates, environments, and luminosity functions of different transient types using detailed Monte Carlo simulations. We illustrate the technique using the observationally well-understood class of type Ia supernovae.

Characterization of an In Vivo Z-DNA Detection Probe Based on a Cell Nucleus Accumulating Intrabody.

PubMed

Gulis, Galina; Silva, Izabel Cristina Rodrigues; Sousa, Herdson Renney; Sousa, Isabel Garcia; Bezerra, Maryani Andressa Gomes; Quilici, Luana Salgado; Maranhao, Andrea Queiroz; Brigido, Marcelo Macedo

2016-09-01

Left-handed Z-DNA is a physiologically unstable DNA conformation, and its existence in vivo can be attributed to localized torsional distress. Despite evidence for the existence of Z-DNA in vivo, its precise role in the control of gene expression is not fully understood. Here, an in vivo probe based on an anti-Z-DNA intrabody is proposed for native Z-DNA detection. The probe was used for chromatin immunoprecipitation of potential Z-DNA-forming sequences in the human genome. One of the isolated putative Z-DNA-forming sequences was cloned upstream of a reporter gene expression cassette under control of the CMV promoter. The reporter gene encoded an antibody fragment fused to GFP. Transient co-transfection of this vector along with the Z-probe coding vector improved reporter gene expression. This improvement was demonstrated by measuring reporter gene mRNA and protein levels and the amount of fluorescence in co-transfected CHO-K1 cells. These results suggest that the presence of the anti-Z-DNA intrabody can interfere with a Z-DNA-containing reporter gene expression. Therefore, this in vivo probe for the detection of Z-DNA could be used for global correlation of Z-DNA-forming sequences and gene expression regulation.

THE DIFFERENCE IMAGING PIPELINE FOR THE TRANSIENT SEARCH IN THE DARK ENERGY SURVEY

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

Kessler, R.; Scolnic, D.; Marriner, J.

2015-12-15

We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg{sup 2} fields are repeatedly observed in the g, r, i, z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImgmore » functions are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are ∼130 detections per deg{sup 2} per observation in each band, of which only ∼25% are artifacts. Of the ∼7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another ∼30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. The DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 “shallow” fields with single-epoch 50% completeness depth ∼23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our 2 “deep” fields with mag-depth ∼24.5, the efficiency falls to 1/2 at z ≈ 1.1. A remaining performance issue is that the measured fluxes have additional scatter (beyond Poisson fluctuations) that increases with the host galaxy surface brightness at the transient location. This bright-galaxy issue has minimal impact on the SNe Ia program, but it may lower the efficiency for finding fainter transients on bright galaxies.« less

The Difference Imaging Pipeline for the Transient Search in the Dark Energy Survey

NASA Astrophysics Data System (ADS)

Kessler, R.; Marriner, J.; Childress, M.; Covarrubias, R.; D'Andrea, C. B.; Finley, D. A.; Fischer, J.; Foley, R. J.; Goldstein, D.; Gupta, R. R.; Kuehn, K.; Marcha, M.; Nichol, R. C.; Papadopoulos, A.; Sako, M.; Scolnic, D.; Smith, M.; Sullivan, M.; Wester, W.; Yuan, F.; Abbott, T.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Carnero Rosell, A.; Carrasco Kind, M.; Castander, F. J.; Crocce, M.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Eifler, T. F.; Fausti Neto, A.; Flaugher, B.; Frieman, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D. J.; Kuropatkin, N.; Li, T. S.; Maia, M. A. G.; Marshall, J. L.; Martini, P.; Miller, C. J.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Sanchez, E.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Tarle, G.; Thaler, J.; Thomas, R. C.; Tucker, D.; Walker, A. R.; DES Collaboration

2015-12-01

We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg2 fields are repeatedly observed in the g, r, i, z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImg functions are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are ˜130 detections per deg2 per observation in each band, of which only ˜25% are artifacts. Of the ˜7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another ˜30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. The DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 “shallow” fields with single-epoch 50% completeness depth ˜23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our 2 “deep” fields with mag-depth ˜24.5, the efficiency falls to 1/2 at z ≈ 1.1. A remaining performance issue is that the measured fluxes have additional scatter (beyond Poisson fluctuations) that increases with the host galaxy surface brightness at the transient location. This bright-galaxy issue has minimal impact on the SNe Ia program, but it may lower the efficiency for finding fainter transients on bright galaxies.

THE DIFFERENCE IMAGING PIPELINE FOR THE TRANSIENT SEARCH IN THE DARK ENERGY SURVEY

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

Kessler, R.; Marriner, J.; Childress, M.

2015-11-06

We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg(2) fields are repeatedly observed in the g, r, i, z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImg functionsmore » are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are similar to 130 detections per deg(2) per observation in each band, of which only similar to 25% are artifacts. Of the similar to 7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another similar to 30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. The DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 "shallow" fields with single-epoch 50% completeness depth similar to 23.5, the SN Ia efficiency falls to 1/2 at redshift z approximate to 0.7; in our 2 "deep" fields with mag-depth similar to 24.5, the efficiency falls to 1/2 at z approximate to 1.1. A remaining performance issue is that the measured fluxes have additional scatter (beyond Poisson fluctuations) that increases with the host galaxy surface brightness at the transient location. This bright-galaxy issue has minimal impact on the SNe Ia program, but it may lower the efficiency for finding fainter transients on bright galaxies.« less

The Difference Imaging Pipeline for the Transient Search in the Dark Energy Survey

DOE PAGES

Kessler, R.

2015-09-09

We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg 2 fields are repeatedly observed in the g, r, i, zpassbands with a cadence of about 1 week. Our observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImg functionsmore » are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are ~130 detections per deg 2 per observation in each band, of which only ~25% are artifacts. Of the ~7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another ~30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. Furthermore, the DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 "shallow" fields with single-epoch 50% completeness depth ~23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our 2 "deep" fields with mag-depth ~24.5, the efficiency falls to 1/2 at z ≈ 1.1. A remaining performance issue is that the measured fluxes have additional scatter (beyond Poisson fluctuations) that increases with the host galaxy surface brightness at the transient location. This bright-galaxy issue has minimal impact on the SNe Ia program, but it may lower the efficiency for finding fainter transients on bright galaxies.« less

OGLE-IV Transient Search report 26 August 2016

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Sitek, M.; Kostrzewa-Rutkowska, Z.; Udalski, A.; Kozlowski, S.; Klencki, J.

2016-08-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013; Klencki et al. 2016, AcA, 66,15) announces resumption of operation in the beginning of 2016B season and discovery of 45 new on-going transients.

Research on photodiode detector-based spatial transient light detection and processing system

NASA Astrophysics Data System (ADS)

Liu, Meiying; Wang, Hu; Liu, Yang; Zhao, Hui; Nan, Meng

2016-10-01

In order to realize real-time signal identification and processing of spatial transient light, the features and the energy of the captured target light signal are first described and quantitatively calculated. Considering that the transient light signal has random occurrence, a short duration and an evident beginning and ending, a photodiode detector based spatial transient light detection and processing system is proposed and designed in this paper. This system has a large field of view and is used to realize non-imaging energy detection of random, transient and weak point target under complex background of spatial environment. Weak signal extraction under strong background is difficult. In this paper, considering that the background signal changes slowly and the target signal changes quickly, filter is adopted for signal's background subtraction. A variable speed sampling is realized by the way of sampling data points with a gradually increased interval. The two dilemmas that real-time processing of large amount of data and power consumption required by the large amount of data needed to be stored are solved. The test results with self-made simulative signal demonstrate the effectiveness of the design scheme. The practical system could be operated reliably. The detection and processing of the target signal under the strong sunlight background was realized. The results indicate that the system can realize real-time detection of target signal's characteristic waveform and monitor the system working parameters. The prototype design could be used in a variety of engineering applications.

Transient myocardial tissue and function changes during a marathon in less fit marathon runners.

PubMed

Gaudreault, Valerie; Tizon-Marcos, Helena; Poirier, Paul; Pibarot, Philippe; Gilbert, Philippe; Amyot, Marc; Rodés-Cabau, Josep; Després, Jean-Pierre; Bertrand, Olivier; Larose, Eric

2013-10-01

Although regular physical activity improves health, strenuous exercise might transiently increase cardiac risk. Training and fitness might provide protection. We prospectively studied 20 recreational marathon runners without known cardiovascular disease or symptoms: at peak training before, immediately after, and 3 months after a 42.2-km marathon. Changes in global/segmental myocardial function, edema, resting perfusion, and fibrosis were measured. At peak training, runners exercised 8.1 ± 2.3 hours and 62 ± 18 km per week with mean maximal oxygen consumption (VO2max) of 53.2 ± 8.3 mL/kg/min. In response to the marathon, global left ventricular and right ventricular ejection fraction decreased in half of the runners; these runners had poorer peak training distance, training time, and fitness level. Change in global left ventricular ejection fraction was associated with VO2max. Overall, 36% of segments developed edema, 53% decreased function, and 59% decreased perfusion. Significant agreement was observed between segment decreasing function, decreasing perfusion, and developing edema. Myocardial changes were reversible at 3 months. Completing a marathon leads to localized myocardial edema, diminished perfusion, and decreased function occurring more extensively in less trained and fit runners. Although reversible, these changes might contribute to the transient increase in cardiac risk reported during sustained vigorous exercise. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Hemispheric language dominance measured by repetitive navigated transcranial magnetic stimulation and postoperative course of language function in brain tumor patients.

PubMed

Ille, Sebastian; Kulchytska, Nataliia; Sollmann, Nico; Wittig, Regina; Beurskens, Eva; Butenschoen, Vicki M; Ringel, Florian; Vajkoczy, Peter; Meyer, Bernhard; Picht, Thomas; Krieg, Sandro M

2016-10-01

The resection of left-sided perisylvian brain lesions harbors the risk of postoperative aphasia. Because it is known that language function can shift between hemispheres in brain tumor patients, the preoperative knowledge of the patient's language dominance could be helpful. We therefore investigated the hemispheric language dominance by repetitive navigated transcranial magnetic stimulation (rTMS) and surgery-related deficits of language function. We pooled the bicentric language mapping data of 80 patients undergoing the resection of left-sided perisylvian brain lesions in our two university neurosurgical departments. We calculated error rates (ERs; ER = errors per stimulations) for both hemispheres and defined the hemispheric dominance ratio (HDR) as the quotient of the left- and right-sided ER (HDR >1= left dominant; HDR <1= right dominant). The course of the patient's language function was evaluated and correlated with the preoperative HDR. Only three of 80 patients (4%) presented with permanent surgery-related aphasia and 24 patients (30%) with transient surgery-related aphasia. The mean HDR (± standard deviation) of patients with new aphasia after five days was significantly higher (1.68±1.07) than the HDR of patients with no new language deficit (1.37±1.08) (p=0.0482). With a predefined cut-off value of 0.5 for HDR, we achieved a sensitivity for predicting new aphasia of 100%. A higher preoperative HDR significantly correlates with an increased risk for transient aphasia. Moreover, the intensive preoperative workup in this study led to a considerably low rate of permanent aphasia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of corneal thickness after the instillation of topical anesthetics: proparacaine versus oxybuprocaine.

PubMed

Nam, Sang Min; Lee, Hyung Keun; Kim, Eung Kweon; Seo, Kyoung Yul

2006-01-01

To compare changes in human corneal thickness after the instillation of proparacaine with those after oxybuprocaine instillation with time over a period of 10 minutes. Eighteen healthy young participants were recruited. Proparacaine was used in the right eye and oxybuprocaine in the left. Right and left baseline corneal thicknesses were measured every 30 seconds for 10 minutes using a noncontact specular microscope by 1 observer. Baseline corneal thickness was defined as the average of all values taken over 10 minutes. Changes in corneal thickness were measured every 20 seconds for 10 minutes after the administration of 1 drop of 0.5% proparacaine onto the right cornea and 1 drop of 0.4% oxybuprocaine onto the left cornea. Mean baseline right cornea thickness was 531 +/- 45 microm, and that of the left cornea was 531 +/- 42 microm. The corneal thickness after proparacaine increased by 8.6 microm ( approximately 4.5-12.6 microm, 95% CI) and then returned to baseline within 80 seconds. Corneal thickness after applying oxybuprocaine increased by 7.7 microm (3.6-11.2 microm, 95% CI) and then returned to baseline within 80 seconds. There was a second transient increase about 5 minutes later after proparacaine instillation but no additional transient increase after oxybuprocaine instillation. Oxybuprocaine is similar to proparacaine in terms of the severity of its effect on corneal thickness. Corneal thickness instability may occur for 5 minutes after proparacaine administration. Changes in corneal thickness after topical anesthetic instillation should be considered when performing measurements for refractive surgery or central corneal thickness in glaucoma patients.

Frequency and predictors of acute ischaemic lesions on brain magnetic resonance imaging in young patients with a clinical diagnosis of transient ischaemic attack.

PubMed

Tanislav, C; Grittner, U; Fazekas, F; Thijs, V; Tatlisumak, T; Huber, R; von Sarnowski, B; Putaala, J; Schmidt, R; Kropp, P; Norrving, B; Martus, P; Gramsch, C; Giese, A K; Rolfs, A; Enzinger, C

2016-07-01

Acute lesions in patients with transient ischaemic attack (TIA) are important as they are associated with increased risk for recurrence. Characteristics associated with acute lesions in young TIA patients were therefore investigated. The sifap1 study prospectively recruited a multinational European cohort (n = 5023) of patients aged 18-55 years with acute cerebrovascular event. The detection of acute ischaemic lesions was based on diffusion-weighted imaging (DWI). The frequency of DWI lesions was assessed in 829 TIA patients who met the criteria of symptom duration <24 h and their association with demographic, clinical and imaging variables was analysed. The median age was 46 years (interquartile range 40-51 years); 45% of the patients were female. In 121 patients (15%) ≥1 acute DWI lesion was detected. In 92 patients, DWI lesions were found in the anterior circulation, mostly located in cortical-subcortical areas (n = 63). Factors associated with DWI lesions in multiple regression analysis were left hemispheric presenting symptoms [odds ratio (OR) 1.92, 95% confidence interval (CI) 1.27-2.91], dysarthria (OR 2.17, 95% CI 1.38-3.43) and old brain infarctions on MRI (territories of the middle and posterior cerebral artery: OR 2.43, 95% CI 1.42-4.15; OR 2.41, 95% CI 1.02-5.69, respectively). In young patients with a clinical TIA 15% demonstrated acute DWI lesions on brain MRI, with an event pattern highly suggestive of an embolic origin. Except for the association with previous infarctions there was no clear clinical predictor for acute ischaemic lesions, which indicates the need to obtain MRI in young individuals with TIA. © 2016 EAN.

A hybrid three-class brain-computer interface system utilizing SSSEPs and transient ERPs

NASA Astrophysics Data System (ADS)

Breitwieser, Christian; Pokorny, Christoph; Müller-Putz, Gernot R.

2016-12-01

Objective. This paper investigates the fusion of steady-state somatosensory evoked potentials (SSSEPs) and transient event-related potentials (tERPs), evoked through tactile simulation on the left and right-hand fingertips, in a three-class EEG based hybrid brain-computer interface. It was hypothesized, that fusing the input signals leads to higher classification rates than classifying tERP and SSSEP individually. Approach. Fourteen subjects participated in the studies, consisting of a screening paradigm to determine person dependent resonance-like frequencies and a subsequent online paradigm. The whole setup of the BCI system was based on open interfaces, following suggestions for a common implementation platform. During the online experiment, subjects were instructed to focus their attention on the stimulated fingertips as indicated by a visual cue. The recorded data were classified during runtime using a multi-class shrinkage LDA classifier and the outputs were fused together applying a posterior probability based fusion. Data were further analyzed offline, involving a combined classification of SSSEP and tERP features as a second fusion principle. The final results were tested for statistical significance applying a repeated measures ANOVA. Main results. A significant classification increase was achieved when fusing the results with a combined classification compared to performing an individual classification. Furthermore, the SSSEP classifier was significantly better in detecting a non-control state, whereas the tERP classifier was significantly better in detecting control states. Subjects who had a higher relative band power increase during the screening session also achieved significantly higher classification results than subjects with lower relative band power increase. Significance. It could be shown that utilizing SSSEP and tERP for hBCIs increases the classification accuracy and also that tERP and SSSEP are not classifying control- and non-control states with the same level of accuracy.

Normal tubular regeneration and differentiation of the post-ischemic kidney in mice lacking vimentin.

PubMed Central

Terzi, F.; Maunoury, R.; Colucci-Guyon, E.; Babinet, C.; Federici, P.; Briand, P.; Friedlander, G.

1997-01-01

Proliferation and dedifferentiation of tubular cells are the hallmark of early regeneration after renal ischemic injury. Vimentin, a class III intermediate filament expressed only in mesenchymal cells of mature mammals, was shown to be transiently expressed in post-ischemic renal tubular epithelial cells. Vimentin re-expression was interpreted as a marker of cellular dedifferentiation, but its role in tubular regeneration after renal ischemia has also been hypothesized. This role was evaluated in mice bearing a null mutation of the vimentin gene. Expression of vimentin, proliferating cell nuclear antigen (a marker of cellular proliferation), and villin (a marker of differentiated brush-border membranes) was studied in wild-type (Vim+/+), heterozygous (Vim+/-), and homozygous (Vim-/-) mice subjected to transient ischemia of the left kidney. As expected, vimentin was detected by immunohistochemistry at the basal pole of proximal tubular cells from post-ischemic kidney in Vim+/+ and Vim+/- mice from day 2 to day 28. The expression of the reporter gene beta-galactosidase in Vim+/- and Vim-/- mice confirmed the tubular origin of vimentin. No compensatory expression of keratin could be demonstrated in Vim-/- mice. The intensity of proliferating cell nuclear antigen labeling and the pattern of villin expression were comparable in Vim-/-, Vim+/- and Vim+/+ mice at any time of the study. After 60 days, the structure of post-ischemic kidneys in Vim-/- mice was indistinguishable from that of normal non-operated kidneys in Vim+/+ mice. In conclusion, 1) the pattern of post-ischemic proximal tubular cell proliferation, differentiation, and tubular organization was not impaired in mice lacking vimentin and 2) these results suggest that the transient tubular expression of vimentin is not instrumental in tubular regeneration after renal ischemic injury. Images Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 PMID:9094992

A bilateral cortical network responds to pitch perturbations in speech feedback

PubMed Central

Kort, Naomi S.; Nagarajan, Srikantan S.; Houde, John F.

2014-01-01

Auditory feedback is used to monitor and correct for errors in speech production, and one of the clearest demonstrations of this is the pitch perturbation reflex. During ongoing phonation, speakers respond rapidly to shifts of the pitch of their auditory feedback, altering their pitch production to oppose the direction of the applied pitch shift. In this study, we examine the timing of activity within a network of brain regions thought to be involved in mediating this behavior. To isolate auditory feedback processing relevant for motor control of speech, we used magnetoencephalography (MEG) to compare neural responses to speech onset and to transient (400ms) pitch feedback perturbations during speaking with responses to identical acoustic stimuli during passive listening. We found overlapping, but distinct bilateral cortical networks involved in monitoring speech onset and feedback alterations in ongoing speech. Responses to speech onset during speaking were suppressed in bilateral auditory and left ventral supramarginal gyrus/posterior superior temporal sulcus (vSMG/pSTS). In contrast, during pitch perturbations, activity was enhanced in bilateral vSMG/pSTS, bilateral premotor cortex, right primary auditory cortex, and left higher order auditory cortex. We also found speaking-induced delays in responses to both unaltered and altered speech in bilateral primary and secondary auditory regions, the left vSMG/pSTS and right premotor cortex. The network dynamics reveal the cortical processing involved in both detecting the speech error and updating the motor plan to create the new pitch output. These results implicate vSMG/pSTS as critical in both monitoring auditory feedback and initiating rapid compensation to feedback errors. PMID:24076223

Results from a model-independent method of monitoring a geodetic network for patterns of transient deformation

NASA Technical Reports Server (NTRS)

Hurst, Kenneth; Granat, Robert

2005-01-01

We have implmented two multi-station detectors for transient crustal deformation within the Southern California Integrated GPS (SCGIN). One the the primary goals of SCIGN is to detect transient deformation associated with the earthquake cycle in Southern California.

Inverse Transient Analysis for Classification of Wall Thickness Variations in Pipelines

PubMed Central

Tuck, Jeffrey; Lee, Pedro

2013-01-01

Analysis of transient fluid pressure signals has been investigated as an alternative method of fault detection in pipeline systems and has shown promise in both laboratory and field trials. The advantage of the method is that it can potentially provide a fast and cost effective means of locating faults such as leaks, blockages and pipeline wall degradation within a pipeline while the system remains fully operational. The only requirement is that high speed pressure sensors are placed in contact with the fluid. Further development of the method requires detailed numerical models and enhanced understanding of transient flow within a pipeline where variations in pipeline condition and geometry occur. One such variation commonly encountered is the degradation or thinning of pipe walls, which can increase the susceptible of a pipeline to leak development. This paper aims to improve transient-based fault detection methods by investigating how changes in pipe wall thickness will affect the transient behaviour of a system; this is done through the analysis of laboratory experiments. The laboratory experiments are carried out on a stainless steel pipeline of constant outside diameter, into which a pipe section of variable wall thickness is inserted. In order to detect the location and severity of these changes in wall conditions within the laboratory system an inverse transient analysis procedure is employed which considers independent variations in wavespeed and diameter. Inverse transient analyses are carried out using a genetic algorithm optimisation routine to match the response from a one-dimensional method of characteristics transient model to the experimental time domain pressure responses. The accuracy of the detection technique is evaluated and benefits associated with various simplifying assumptions and simulation run times are investigated. It is found that for the case investigated, changes in the wavespeed and nominal diameter of the pipeline are both important to the accuracy of the inverse analysis procedure and can be used to differentiate the observed transient behaviour caused by changes in wall thickness from that caused by other known faults such as leaks. Further application of the method to real pipelines is discussed.

Semi-Supervised Novelty Detection with Adaptive Eigenbases, and Application to Radio Transients

NASA Technical Reports Server (NTRS)

Thompson, David R.; Majid, Walid A.; Reed, Colorado J.; Wagstaff, Kiri L.

2011-01-01

We present a semi-supervised online method for novelty detection and evaluate its performance for radio astronomy time series data. Our approach uses adaptive eigenbases to combine 1) prior knowledge about uninteresting signals with 2) online estimation of the current data properties to enable highly sensitive and precise detection of novel signals. We apply the method to the problem of detecting fast transient radio anomalies and compare it to current alternative algorithms. Tests based on observations from the Parkes Multibeam Survey show both effective detection of interesting rare events and robustness to known false alarm anomalies.

Physiological response of cardiac tissue to bisphenol a: alterations in ventricular pressure and contractility

PubMed Central

Brooks, Daina; Chandra, Akhil; Jaimes, Rafael; Sarvazyan, Narine; Kay, Matthew

2015-01-01

Biomonitoring studies have indicated that humans are routinely exposed to bisphenol A (BPA), a chemical that is commonly used in the production of polycarbonate plastics and epoxy resins. Epidemiological studies have shown that BPA exposure in humans is associated with cardiovascular disease; however, the direct effects of BPA on cardiac physiology are largely unknown. Previously, we have shown that BPA exposure slows atrioventricular electrical conduction, decreases epicardial conduction velocity, and prolongs action potential duration in excised rat hearts. In the present study, we tested if BPA exposure also adversely affects cardiac contractile performance. We examined the impact of BPA exposure level, sex, and pacing rate on cardiac contractile function in excised rat hearts. Hearts were retrogradely perfused at constant pressure and exposed to 10−9-10−4 M BPA. Left ventricular developed pressure and contractility were measured during sinus rhythm and during pacing (5, 6.5, and 9 Hz). Ca2+ transients were imaged from whole hearts and from neonatal rat cardiomyocyte layers. During sinus rhythm in female hearts, BPA exposure decreased left ventricular developed pressure and inotropy in a dose-dependent manner. The reduced contractile performance was exacerbated at higher pacing rates. BPA-induced effects on contractile performance were also observed in male hearts, albeit to a lesser extent. Exposure to BPA altered Ca2+ handling within whole hearts (reduced diastolic and systolic Ca2+ transient potentiation) and neonatal cardiomyocytes (reduced Ca2+ transient amplitude and prolonged Ca2+ transient release time). In conclusion, BPA exposure significantly impaired cardiac performance in a dose-dependent manner, having a major negative impact upon electrical conduction, intracellular Ca2+ handing, and ventricular contractility. PMID:25980024

Frequency of Inverted Electrocardiographic T Waves (Cerebral T Waves) in Patients With Acute Strokes and Their Relation to Left Ventricular Wall Motion Abnormalities.

PubMed

Stone, Jeremy; Mor-Avi, Victor; Ardelt, Agnieszka; Lang, Roberto M

2018-01-01

Transient, symmetric, and deep inverted electrocardiogram (ECG) T waves in the setting of stroke, commonly referred to as cerebral T waves, are rare, and the underlying mechanism is unclear. Our study aimed to test the hypothesis that cerebral T waves are associated with transient cardiac dysfunction. This retrospective study included 800 patients admitted with the primary diagnosis of hemorrhagic or ischemic stroke. ECGs were examined for cerebral T waves, defined as T-wave inversion of ≥5 mm depth in ≥4 contiguous precordial leads. Echocardiograms of those meeting these criteria were examined for the presence of left ventricular (LV) wall motion abnormalities. Follow-up evaluation included both ECG and echocardiogram. Of the 800 patients, 17 had cerebral T waves on ECG (2.1%). All 17 patients had ischemic strokes, of which 11 were in the middle cerebral artery distribution (65%), and 2 were cerebellar (12%), whereas the remaining 4 involved other locations. Follow-up ECG showed resolution of the T-wave changes in all 17 patients. Of these patients, 14 (82%) had normal wall motion, and 3 had transient wall motion abnormalities (18%). Two of these patients had Takotsubo-like cardiomyopathy with apical ballooning, and the third had globally reduced LV function. Coronary angiography showed no significant disease to explain the LV dysfunction. In summary, in our cohort of patients with acute stroke, cerebral T waves were rare and occurred only in ischemic stroke. Eighteen percent of patients with cerebral T waves had significant transient wall motion abnormalities. Patients with stroke with cerebral T waves, especially in those with ischemic strokes, should be assessed for cardiac dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparing the effects of sustained and transient spatial attention on the orienting towards and the processing of electrical nociceptive stimuli.

PubMed

Van der Lubbe, Rob H J; Blom, Jorian H G; De Kleine, Elian; Bohlmeijer, Ernst T

2017-02-01

We examined whether sustained vs. transient spatial attention differentially affect the processing of electrical nociceptive stimuli. Cued nociceptive stimuli of a relevant intensity (low or high) on the left or right forearm required a foot pedal press. The cued side varied trial wise in the transient attention condition, while it remained constant during a series of trials in the sustained attention condition. The orienting phase preceding the nociceptive stimuli was examined by focusing on lateralized EEG activity. ERPs were computed to examine the influence of spatial attention on the processing of the nociceptive stimuli. Results for the orienting phase showed increased ipsilateral alpha and beta power above somatosensory areas in both the transient and the sustained attention conditions, which may reflect inhibition of ipsilateral and/or disinhibition of contralateral somatosensory areas. Cued nociceptive stimuli evoked a larger N130 than uncued stimuli, both in the transient and the sustained attention conditions. Support for increased efficiency of spatial attention in the sustained attention condition was obtained for the N180 and the P540 component. We concluded that spatial attention is more efficient in the case of sustained than in the case of transient spatial attention. Copyright © 2016 Elsevier B.V. All rights reserved.

OGLE-IV Transient Search report 07 August 2015

NASA Astrophysics Data System (ADS)

Wyrzykowski, L.; Kostrzewa-Rutkowska, Z.; Udalski, A.; Kozlowski, S.; Poleski, R.; Pietrzynski, G.; Sitek, M.

2015-08-01

The OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013) reports the discovery of 10 new transients. Most of them appeared near or on top of apparent galaxies and their light curves resemble those of supernovae near or after their peak brightness.

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

PubMed

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

2014-06-01

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

Tricuspid and mitral regurgitation detected by color flow Doppler in the acute phase of Kawasaki disease

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

Suzuki, A.; Kamiya, T.; Tsuchiya, K.

Valvular lesions in the acute phase of Kawasaki disease were studied in 19 children. The patients were intensively observed by color flow Doppler every day from the day of hospitalization up to 12 days after the onset of the disease and 2 or more times a week thereafter, for up to 28 days. Mitral regurgitation (MR) was found in 9 patients (47%) and tricuspid regurgitation (TR) in 10 (53%). MRs were of transient type and confirmed from 7.5 +/- 1.6 (mean +/- standard deviation) to 13.1 +/- 6.5 days after the onset of the disease. Both types of valvular regurgitationmore » were mild. The direction of regurgitation was from the center of valvular coaptation toward the posterior wall of the atrium. Neither valvular prolapse nor valvular deformity was noted. In patients with MR, left ventricular ejection fraction on M-mode echocardiography was significantly lower in the acute phase than in the convalescent phase of the disease (p less than 0.05). Using gallium-67 scintigram, the positive uptake of the isotope was noted in 7 (88%) of 8 patients with MR, but not found at all in 8 patients free of MR. These results suggest that MR and TR are often transient in the acute phase of Kawasaki disease and could be attributed to myocarditis.« less

Choroid vascular occlusion and ischemic optic neuropathy after facial calcium hydroxyapatite injection- a case report.

PubMed

Chou, Chien-Chih; Chen, Hsin-Han; Tsai, Yi-Yu; Li, You-Ling; Lin, Hui-Ju

2015-03-08

We reported a case of sudden monocular vision loss after calcium hydroxyapatite (CaHA) injection into the nasal tip and dorsum with detailed retina images. A healthy, 35-year-old woman received CaHA filler injection for nose augmentation. Ten minutes after the procedure, she developed nausea, vomiting, headache, ptosis, and left periorbital pain. After 30 minutes, she complained of progressively blurring vision in the left eye. The best-corrected visual acuity (BCVA) in her left eye was 30 cm ahead of hand motion. Left exotropia was noted in primary gaze. Limitations in adduction, supraduction, and infraduction of the left eye were also observed. Slit lamp examination of the left eye revealed a pink conjunctiva, a clear cornea, a mild anterior chamber reaction, a sluggish papillary light reflex, and a semi-dilated pupil. A positive relative afferent pupillary defect was observed in the left eye. Fundus examination revealed optic disc edema and some linear whitish opacity over the superior and temporal sites in the left eye, suggesting multiple CaHA emboli in the choroid vessels. Although the majority of adverse reactions are mild and transient, surgeons should be alert about extremely rare serious adverse events such as visual loss.

Congenital left ventricular wall abnormalities in adults detected by gated cardiac multidetector computed tomography: clefts, aneurysms, diverticula and terminology problems.

PubMed

Erol, Cengiz; Koplay, Mustafa; Olcay, Ayhan; Kivrak, Ali Sami; Ozbek, Seda; Seker, Mehmet; Paksoy, Yahya

2012-11-01

Our aim was to evaluate congenital left ventricular wall abnormalities (clefts, aneurysms and diverticula), describe and illustrate imaging features, discuss terminology problems and determine their prevalence detected by cardiac CT in a single center. Coronary CT angiography images of 2093 adult patients were evaluated retrospectively in order to determine congenital left ventricular wall abnormalities. The incidence of left ventricular clefts (LVC) was 6.7% (141 patients) and statistically significant difference was not detected between the sexes regarding LVC (P=0.5). LVCs were single in 65.2% and multiple in 34.8% of patients. They were located at the basal to mid inferoseptal segment of the left ventricle in 55.4%, the basal to mid anteroseptal segment in 24.1%, basal to mid inferior segment in 17% and septal-apical septal segment in 3.5% of cases. The cleft length ranged from 5 to 22 mm (mean 10.5 mm) and they had a narrow connection with the left ventricle (mean 2.5 mm). They were contractile with the left ventricle and obliterated during systole. Congenital left ventricular septal aneurysm that was located just under the aortic valve was detected in two patients (0.1%). No case of congenital left ventricular diverticulum was detected. Cardiac CT allows us to recognize congenital left ventricular wall abnormalities which have been previously overlooked in adults. LVC is a congenital structural variant of the myocardium, is seen more frequently than previously reported and should be differentiated from aneurysm and diverticulum for possible catastrophic complications of the latter two. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Right-to-left shunt detection sensitivity with air-saline and air-succinil gelatin transcranial Doppler.

PubMed

Puledda, Francesca; Toscano, Massimiliano; Pieroni, Alessio; Veneroso, Gabriele; Di Piero, Vittorio; Vicenzini, Edoardo

2016-02-01

Air-saline transcranial Doppler is nowadays the first-choice examination to identify right-to-left shunt. To increase right-to-left shunt detection in echocardiography, cardiologists also use air-gelatin mixtures, which are more stable, more echogenic, and easier to be prepared. We assessed the sensitivity of air-gelatin compared with air-saline for transcranial Doppler right-to-left shunt detection. Air-saline transcranial Doppler, during unilateral middle cerebral artery monitoring at rest and after Valsalva maneuver, was performed in patients referred to our neurosonology laboratory for right-to-left shunt detection. The same transcranial Doppler protocol was repeated with air-gelatin. To consider transcranial Doppler positive for cardiac right-to-left shunt, at least one embolic signal had to be detected within 20″ from contrast injection. Later signals were interpreted of pulmonary origin. Trans-thoracic echocardiography was repeated with both air-saline and air-gelatin. A total of 97 patients were enrolled; 46 had negative transcranial Doppler for cardiac right-to-left shunt with both air-saline and air-gelatin; out of these, four patients with air-saline plus two more patients with air-gelatin presented late, isolated microemboli, slightly more numerous with air-gelatin: these were interpreted as pulmonary shunts and confirmed with trans-thoracic echocardiography. In 28 patients with already early positive air-saline transcranial Doppler at rest, air-gelatin induced a marked right-to-left shunt increase, facilitating its visualization at trans-thoracic echocardiography. In 23 patients in whom air-saline transcranial Doppler was negative at rest and positive for cardiac right-to-left shunt only after Valsalva maneuver, air-gelatin was able to reveal shunt also at rest. Air-gelatin increases right-to-left shunt detection sensitivity with transcranial Doppler in particular at rest, even in patients in whom air-saline mixture fails to identify the shunt. The choice of air-gelatin mixture should be considered for multicentric, clinical, and research trials. © 2016 World Stroke Organization.

Real-time Recovery Efficiencies and Performance of the Palomar Transient Factory's Transient Discovery Pipeline

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

Frohmaier, C.; Sullivan, M.; Nugent, P. E.

In this paper, we present the transient source detection efficiencies of the Palomar Transient Factory (PTF), parameterizing the number of transients that PTF found versus the number of similar transients that occurred over the same period in the survey search area but were missed. PTF was an optical sky survey carried out with the Palomar 48 inch telescope over 2009–2012, observing more than 8000 square degrees of sky with cadences of between one and five days, locating around 50,000 non-moving transient sources, and spectroscopically confirming around 1900 supernovae. We assess the effectiveness with which PTF detected transient sources, by insertingmore » $$\\simeq 7$$ million artificial point sources into real PTF data. We then study the efficiency with which the PTF real-time pipeline recovered these sources as a function of the source magnitude, host galaxy surface brightness, and various observing conditions (using proxies for seeing, sky brightness, and transparency). The product of this study is a multi-dimensional recovery efficiency grid appropriate for the range of observing conditions that PTF experienced and that can then be used for studies of the rates, environments, and luminosity functions of different transient types using detailed Monte Carlo simulations. Finally, we illustrate the technique using the observationally well-understood class of type Ia supernovae.« less

Real-time Recovery Efficiencies and Performance of the Palomar Transient Factory's Transient Discovery Pipeline

DOE PAGES

Frohmaier, C.; Sullivan, M.; Nugent, P. E.; ...

2017-05-09

In this paper, we present the transient source detection efficiencies of the Palomar Transient Factory (PTF), parameterizing the number of transients that PTF found versus the number of similar transients that occurred over the same period in the survey search area but were missed. PTF was an optical sky survey carried out with the Palomar 48 inch telescope over 2009–2012, observing more than 8000 square degrees of sky with cadences of between one and five days, locating around 50,000 non-moving transient sources, and spectroscopically confirming around 1900 supernovae. We assess the effectiveness with which PTF detected transient sources, by insertingmore » $$\\simeq 7$$ million artificial point sources into real PTF data. We then study the efficiency with which the PTF real-time pipeline recovered these sources as a function of the source magnitude, host galaxy surface brightness, and various observing conditions (using proxies for seeing, sky brightness, and transparency). The product of this study is a multi-dimensional recovery efficiency grid appropriate for the range of observing conditions that PTF experienced and that can then be used for studies of the rates, environments, and luminosity functions of different transient types using detailed Monte Carlo simulations. Finally, we illustrate the technique using the observationally well-understood class of type Ia supernovae.« less

Transient global amnesia after taking sibutramine: a case report.

PubMed

Fu, Pin-Kuei; Hsu, Hung-Yi; Wang, Pao-Yu

2010-03-01

Sibutramine (Meridia in the United States, Reductil in Europe) is approved for weight reduction and weight maintenance. Although amnesia and seizure is listed as a reported adverse event of sibutramine in the US product information, our literature search in the PubMed website database found no published reports of theses adverse events. We report a 39-year-old healthy woman who had an episode of sudden memory loss lasting for several hours after taking sibutramine for 4 days. Cranial computed tomography scan, magnetic resonance imaging, and magnetic resonance angiography of the head all showed normal results. Electroencephalogram showed spike and wave complexes with phase reversal in the left mesial temporal area. Transient global amnesia was suspected clinically and transient epileptic amnesia provoked by sibutramine was also proposed. Three months after this episode, the follow-up electroencephalogram was normal. This patient did not take any anticonvulsant, and there were no more episodes of memory impairment. This case serves to emphasize that sibutramine which was used for weight reduction might induce transient global amnesia or provoke transient epileptic amnesia. Physicians should be careful to monitor for this adverse effect when sibutramine is prescribed.

Status Of The Swift Burst Alert Telescope Hard X-ray Transient Monitor

NASA Astrophysics Data System (ADS)

Krimm, Hans A.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J.; Fenimore, E.; Gehrels, N.; Markwardt, C. B.; Palmer, D.; Sakamoto, T.; Skinner, G. K.; Stamatikos, M.; Tueller, J.

2010-01-01

The Swift Burst Alert Telescope hard X-ray transient monitor has been operating since October 1, 2006. More than 700 sources are tracked on a daily basis and light curves are produced and made available to the public on two time scales: a single Swift pointing (approximately 20 minutes) and the weighted average for each day. Of the monitored sources, approximately 33 are detected daily and another 100 have had one or more outburst during the Swift mission. The monitor is also sensitive to the detection of previously undiscovered sources and we have reported the discovery of four galactic sources and one source in the Large Magellanic Cloud. Follow-up target of opportunity observations with Swift and the Rossi X-Ray Timing Explorer have revealed that three of these new sources are pulsars and two are black hole candidates. In addition, the monitor has led to the announcement of significant outbursts from 24 different galactic and extra-galactic sources, many of which have had follow-up Swift XRT, UVOT and ground based multi-wavelength observations. The transient monitor web pages currently receive an average of 21 visits per day. We will report on the most important results from the transient monitor and also on detection and exposure statistics and outline recent and planned improvements to the monitor. The transient monitor web page is http://swift.gsfc.nasa.gov/docs/swift/results/transients/.

Blood RNA biomarker panel detects both left- and right-sided colorectal neoplasms: a case-control study.

PubMed

Chao, Samuel; Ying, Jay; Liew, Gailina; Marshall, Wayne; Liew, Choong-Chin; Burakoff, Robert

2013-07-23

Colonoscopy is widely regarded to be the gold standard for colorectal cancer (CRC) detection. Recent studies, however, suggest that the effectiveness of colonoscopy is mostly confined to tumors on the left side of the colon (descending, sigmoid, rectum), and that the technology has poor tumor detection for right-sided (cecum, ascending, transverse) lesions. A minimally invasive test that can detect both left-sided and right-sided lesions could increase the effectiveness of screening colonoscopy by revealing the potential presence of neoplasms in the right-sided "blind spot". We previously reported on a seven-gene, blood-based biomarker panel that effectively stratifies a patient's risk of having CRC. For the current study, we assessed the effectiveness of the seven-gene panel for the detection of left- and right-sided CRC lesions. Results were evaluated for 314 patients with CRC (left-sided: TNM I, 65; TNM II, 57; TNM III, 60; TNM IV, 17; unknown, 9. right-sided: TNM I, 28; TNM II, 29; TNM III, 38; TNM IV, 12; unknown, 1 and including two samples with both left and right lesions) and 328 control samples. Blood samples were obtained prior to clinical staging and therapy. Most CRC subjects had localized disease (stages I and II, 58%); regional (stage III) and systemic (stage IV) disease represented 32% and 9%, respectively, of the study population. The panel detected left-sided (74%, 154/208) and right-sided (85%, 92/108) lesions with an overall sensitivity of 78% (215/316) at a specificity of 66% (215/328). Treatable cancer (stages I to III) was detected with left-sided lesion sensitivity of 76% (138/182) and right-sided sensitivity of 84% (80/95). This seven-gene biomarker panel detected right-sided CRC lesions across all cancer stages with a sensitivity that is at least equal to that for left-sided lesions. This study supports the use of this panel as the basis for a patient-friendly, blood-based test that can be easily incorporated into a routine physical examination in advance of colonoscopy to provide a convenient companion diagnostic and a pre-screening alert, ultimately leading to enhanced CRC screening effectiveness.

Recurrent patterns of atrial depolarization during atrial fibrillation assessed by recurrence plot quantification.

PubMed

Censi, F; Barbaro, V; Bartolini, P; Calcagnini, G; Michelucci, A; Gensini, G F; Cerutti, S

2000-01-01

The aim of this study was to determine the presence of organization of atrial activation processes during atrial fibrillation (AF) by assessing whether the activation sequences are wholly random or are governed by deterministic mechanisms. We performed both linear and nonlinear analyses based on the cross correlation function (CCF) and recurrence plot quantification (RPQ), respectively. Recurrence plots were quantified by three variables: percent recurrence (PR), percent determinism (PD), and entropy of recurrences (ER). We recorded bipolar intra-atrial electrograms in two atrial sites during chronic AF in 19 informed subjects, following two protocols. In one, both recording sites were in the right atrium; in the other protocol, one site was in the right atrium, the other one in the left atrium. We extracted 19 episodes of type I AF (Wells' classification). RPQ detected transient recurrent patterns in all the episodes, while CCF was significant only in ten episodes. Surrogate data analysis, based on a cross-phase randomization procedure, decreased PR, PD, and ER values. The detection of spatiotemporal recurrent patterns together with the surrogate data results indicate that during AF a certain degree of local organization exists, likely caused by deterministic mechanisms of activation.

The Caltech-NRAO Stripe 82 Survey (CNSS) Paper. I. The Pilot Radio Transient Survey in 50 Deg.(exp. 2)

NASA Technical Reports Server (NTRS)

Mooley, K. P.; Hallinan, G.; Bourke, S.; Horesh, A.; Myers, S. T.; Frail, D. A.; Kulkarni, S. R.; Levitan, D. B.; Kasliwal, M. M.; Cenko, S. B.;

The Rapidly Moving Telescope: an Instrument for the Precise Study of Optical Transients

NASA Technical Reports Server (NTRS)

Teegarden, B. J.; Vonrosenvinge, T. T.; Cline, T. L.; Kaipa, R.

1983-01-01

The development of a small telescope with a very rapid pointing capability is described whose purpose is to search for and study fast optical transients that may be associated with gamma-ray bursts and other phenomena. The primary motivation for this search is the discovery of the existence of a transient optical event from the known location of a gamma-ray bursts. The telescope has the capability of rapidly acquiring any target in the night sky within 0.7 second and locating the object's position with + or - 1 arcsec accuracy. The initial detection of the event is accomplished by the MIT explosive transient camera or ETC. This provides rough pointing coordinates to the RMT on the average within approximately 1 second after the detection of the event.

Cortical cholinergic signaling controls the detection of cues

PubMed Central

Gritton, Howard J.; Howe, William M.; Mallory, Caitlin S.; Hetrick, Vaughn L.; Berke, Joshua D.; Sarter, Martin

2016-01-01

The cortical cholinergic input system has been described as a neuromodulator system that influences broadly defined behavioral and brain states. The discovery of phasic, trial-based increases in extracellular choline (transients), resulting from the hydrolysis of newly released acetylcholine (ACh), in the cortex of animals reporting the presence of cues suggests that ACh may have a more specialized role in cognitive processes. Here we expressed channelrhodopsin or halorhodopsin in basal forebrain cholinergic neurons of mice with optic fibers directed into this region and prefrontal cortex. Cholinergic transients, evoked in accordance with photostimulation parameters determined in vivo, were generated in mice performing a task necessitating the reporting of cue and noncue events. Generating cholinergic transients in conjunction with cues enhanced cue detection rates. Moreover, generating transients in noncued trials, where cholinergic transients normally are not observed, increased the number of invalid claims for cues. Enhancing hits and generating false alarms both scaled with stimulation intensity. Suppression of endogenous cholinergic activity during cued trials reduced hit rates. Cholinergic transients may be essential for synchronizing cortical neuronal output driven by salient cues and executing cue-guided responses. PMID:26787867

Goaf water detection using the grounded electrical source airborne transient electromagnetic system

NASA Astrophysics Data System (ADS)

Li, D.; Ji, Y.; Guan, S.; Wu, Y.; Wang, A.

2017-12-01

To detect the geoelectric characteristic of goaf water, the grounded electrical source airborne transient electromagnetic (GREATEM) system (developed by Jilin University, China) is applied to the goaf water detection since its advantages of considerable prospecting depth, lateral resolution and detection efficiency. For the test of GREATEM system in goaf water detection, an experimental survey was conducted at Qinshui coal mine (Shanxi province, China). After data acquisition, noise reduction and inversion, the resistivity profiles of survey area is presented. The results highly agree the investigation information provided by Shanxi Coal Geology Geophysical Surveying Exploration Institute (China), conforming that the GREATEM system is an effective technique for resistivity detection of goaf water.

Blind detection of isolated astrophysical pulses in the spatial Fourier transform domain

NASA Astrophysics Data System (ADS)

Schmid, Natalia A.; Prestage, Richard M.

2018-07-01

We present a novel approach for the detection of isolated transients in pulsar surveys and fast radio transient observations. Rather than the conventional approach of performing a computationally expensive blind dispersion measure search, we take the spatial Fourier transform (SFT) of short (˜ few seconds) sections of data. A transient will have a characteristic signature in the SFT domain, and we present a blind statistic which may be used to detect this signature at an empirical zero false alarm rate. The method has been evaluated using simulations, and also applied to two fast radio burst observations. In addition to its use for current observations, we expect this method will be extremely beneficial for future multibeam observations made by telescopes equipped with phased array feeds.

Blind detection of isolated astrophysical pulses in the spatial Fourier transform domain

NASA Astrophysics Data System (ADS)

Schmid, Natalia A.; Prestage, Richard M.

2018-04-01

We present a novel approach for the detection of isolated transients in pulsar surveys and fast radio transient observations. Rather than the conventional approach of performing a computationally expensive blind DM search, we take the spatial Fourier transform (SFT) of short (˜ few seconds) sections of data. A transient will have a characteristic signature in the SFT domain, and we present a blind statistic which may be used to detect this signature at an empirical zero False Alarm Rate (FAR). The method has been evaluated using simulations, and also applied to two fast radio burst observations. In addition to its use for current observations, we expect this method will be extremely beneficial for future multi-beam observations made by telescopes equipped with phased array feeds.

Understanding the importance of transient resonances in extreme mass ratio inspirals

NASA Astrophysics Data System (ADS)

Berry, C. P. L.; Cole, R. H.; Cañizares, P.; Gair, J. R.

2017-05-01

Extreme mass ratio inspirals (EMRIs) occur when a compact object orbits a much larger one, like a solar-mass black hole around a supermassive black hole. The orbit has 3 frequencies which evolve through the inspiral. If the orbital radial frequency and polar frequency become commensurate, the system passes through a transient resonance. Evolving through resonance causes a jump in the evolution of the orbital parameters. We study these jumps and their impact on EMRI gravitational-wave detection. Jumps are smaller for lower eccentricity orbits; since most EMRIs have small eccentricities when passing through resonances, we expect that the impact on detection will be small. Neglecting the effects of transient resonances leads to a loss of ∼ 4% of detectable signals for an astrophysically motivated population of EMRIs.

IDIOPATHIC MULTIFOCAL CHOROIDITIS PRESENTING WITH A TRANSIENT PERIPAPILLARY WHITE RING.

PubMed

Gattoussi, Sarra; Ghadiali, Quraish; Dolz-Marco, Rosa; Freund, K Bailey

2017-11-22

We describe with multimodal imaging the presentation and follow-up for a patient with idiopathic multifocal choroiditis and a transient peripapillary white ring. Case report. A 39-year-old Asian woman was initially seen for an evaluation of lattice degeneration in 2015. Her medical history included Graves disease and psoriasis. Best-corrected visual acuity was 20/25 in her right eye and 20/25 in her left eye. Ultra-widefield fundus autofluorescence imaging showed a curvilinear hyperautofluorescent line in her right eye. One year later, the patient returned complaining of floaters in her right eye for 1 month. Her visual acuity was unchanged. Funduscopic examination showed new inflammatory yellowish lesions in the right eye corresponding to hyperreflective sub-retinal pigment epithelium lesions on structural spectral domain optical coherence tomography. Fluorescein angiography showed corresponding late staining of these active lesions. Late-phase indocyanine green angiography showed multiple nummular hypocyanescent dots. Ultra-widefield fundus autofluorescence showed large areas of hyperautofluorescence. The patient was started on a 60-mg oral prednisone taper and demonstrated subsequent regression of the inflammatory lesions. Ten months later, the patient returned emergently with complaints of floaters in both eyes for 2 days and a new temporal scotoma in her left eye. Funduscopic examination demonstrated a white ring around the optic nerve of the left eye corresponding to a hyperautofluorescent lesion. Ultra-widefield fundus autofluorescence showed new areas of hyperautofluorescence in both eyes. Structural spectral domain optical coherence tomography showed new sub-retinal pigment epithelium inflammatory lesions and a disruption of the ellipsoid zone in both eyes. The patient was again treated with a 60-mg oral prednisone taper and demonstrated subsequent restoration of the ellipsoid zone. To our knowledge, this is the first report of a transient annular white ring occurring in a case of multifocal choroiditis. There was marked restoration of the disrupted ellipsoid zone after treatment with oral corticosteroids.

Sensitivity quantification of remote detection NMR and MRI

NASA Astrophysics Data System (ADS)

Granwehr, J.; Seeley, J. A.

2006-04-01

A sensitivity analysis is presented of the remote detection NMR technique, which facilitates the spatial separation of encoding and detection of spin magnetization. Three different cases are considered: remote detection of a transient signal that must be encoded point-by-point like a free induction decay, remote detection of an experiment where the transient dimension is reduced to one data point like phase encoding in an imaging experiment, and time-of-flight (TOF) flow visualization. For all cases, the sensitivity enhancement is proportional to the relative sensitivity between the remote detector and the circuit that is used for encoding. It is shown for the case of an encoded transient signal that the sensitivity does not scale unfavorably with the number of encoded points compared to direct detection. Remote enhancement scales as the square root of the ratio of corresponding relaxation times in the two detection environments. Thus, remote detection especially increases the sensitivity of imaging experiments of porous materials with large susceptibility gradients, which cause a rapid dephasing of transverse spin magnetization. Finally, TOF remote detection, in which the detection volume is smaller than the encoded fluid volume, allows partial images corresponding to different time intervals between encoding and detection to be recorded. These partial images, which contain information about the fluid displacement, can be recorded, in an ideal case, with the same sensitivity as the full image detected in a single step with a larger coil.

Protection of Renewable-dominated Microgrids: Challenges and Potential Solutions.

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

Elkhatib, Mohamed; Ellis, Abraham; Milan Biswal

keywords : Microgrid Protection, Impedance Relay, Signal Processing-based Fault Detec- tion, Networked Microgrids, Communication-Assisted Protection In this report we address the challenge of designing efficient protection system for inverter- dominated microgrids. These microgrids are characterised with limited fault current capacity as a result of current-limiting protection functions of inverters. Typically, inverters limit their fault contribution in sub-cycle time frame to as low as 1.1 per unit. As a result, overcurrent protection could fail completely to detect faults in inverter-dominated microgrids. As part of this project a detailed literature survey of existing and proposed microgrid protection schemes were conducted. The surveymore » concluded that there is a gap in the available microgrid protection methods. The only credible protection solution available in literature for low- fault inverter-dominated microgrids is the differential protection scheme which represents a robust transmission-grade protection solution but at a very high cost. Two non-overcurrent protection schemes were investigated as part of this project; impedance-based protection and transient-based protection. Impedance-based protection depends on monitoring impedance trajectories at feeder relays to detect faults. Two communication-based impedance-based protection schemes were developed. the first scheme utilizes directional elements and pilot signals to locate the fault. The second scheme depends on a Central Protection Unit that communicates with all feeder relays to locate the fault based on directional flags received from feeder relays. The later approach could potentially be adapted to protect networked microgrids and dynamic topology microgrids. Transient-based protection relies on analyzing high frequency transients to detect and locate faults. This approach is very promising but its implementation in the filed faces several challenges. For example, high frequency transients due to faults can be confused with transients due to other events such as capacitor switching. Additionally, while detecting faults by analyzing transients could be doable, locating faults based on analyzing transients is still an open question.« less

Protection of Renewable-dominated Microgrids: Challenges and Potential Solutions

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

Elkhatib, Mohamed; Ellis, Abraham; Biswal, Milan

In this report we address the challenge of designing efficient protection system for inverter- dominated microgrids. These microgrids are characterised with limited fault current capacity as a result of current-limiting protection functions of inverters. Typically, inverters limit their fault contribution in sub-cycle time frame to as low as 1.1 per unit. As a result, overcurrent protection could fail completely to detect faults in inverter-dominated microgrids. As part of this project a detailed literature survey of existing and proposed microgrid protection schemes were conducted. The survey concluded that there is a gap in the available microgrid protection methods. The only crediblemore » protection solution available in literature for low- fault inverter-dominated microgrids is the differential protection scheme which represents a robust transmission-grade protection solution but at a very high cost. Two non-overcurrent protection schemes were investigated as part of this project; impedance-based protection and transient-based protection. Impedance-based protection depends on monitoring impedance trajectories at feeder relays to detect faults. Two communication-based impedance-based protection schemes were developed. the first scheme utilizes directional elements and pilot signals to locate the fault. The second scheme depends on a Central Protection Unit that communicates with all feeder relays to locate the fault based on directional flags received from feeder relays. The later approach could potentially be adapted to protect networked microgrids and dynamic topology microgrids. Transient-based protection relies on analyzing high frequency transients to detect and locate faults. This approach is very promising but its implementation in the filed faces several challenges. For example, high frequency transients due to faults can be confused with transients due to other events such as capacitor switching. Additionally, while detecting faults by analyzing transients could be doable, locating faults based on analyzing transients is still an open question.« less

On-Die Sensors for Transient Events

NASA Astrophysics Data System (ADS)

Suchak, Mihir Vimal

Failures caused by transient electromagnetic events like Electrostatic Discharge (ESD) are a major concern for embedded systems. The component often failing is an integrated circuit (IC). Determining which IC is affected in a multi-device system is a challenging task. Debugging errors often requires sophisticated lab setups which require intentionally disturbing and probing various parts of the system which might not be easily accessible. Opening the system and adding probes may change its response to the transient event, which further compounds the problem. On-die transient event sensors were developed that require relatively little area on die, making them inexpensive, they consume negligible static current, and do not interfere with normal operation of the IC. These circuits can be used to determine the pin involved and the level of the event in the event of a transient event affecting the IC, thus allowing the user to debug system-level transient events without modifying the system. The circuit and detection scheme design has been completed and verified in simulations with Cadence Virtuoso environment. Simulations accounted for the impact of the ESD protection circuits, parasitics from the I/O pin, package and I/O ring, and included a model of an ESD gun to test the circuit's response to an ESD pulse as specified in IEC 61000-4-2. Multiple detection schemes are proposed. The final detection scheme consists of an event detector and a level sensor. The event detector latches on the presence of an event at a pad, to determine on which pin an event occurred. The level sensor generates current proportional to the level of the event. This current is converted to a voltage and digitized at the A/D converter to be read by the microprocessor. Detection scheme shows good performance in simulations when checked against process variations and different kind of events.

A case of transient central diabetes insipidus after aorto-coronary bypass operation.

PubMed

Yu, Chung-Hoon; Cho, Jang-Hee; Jung, Hee-Yeon; Lim, Jeong-Hoon; Jin, Mi-Kyung; Kwon, Owen; Hong, Kyung-Deuk; Choi, Ji-Young; Yoon, Se-Hee; Kim, Chan-Duck; Kim, Yong-Lim; Kim, Gun-Jik; Park, Sun-Hee

2012-09-01

Diabetes insipidus (DI) is characterized by excessive urination and thirst. This disease results from inadequate output of antidiuretic hormone (ADH) from the pituitary gland or the absence of the normal response to ADH in the kidney. We present a case of transient central DI in a patient who underwent a cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG). A 44-yr-old male underwent a CABG operation. An hour after the operation, the patient developed polyuria and was diagnosed with central DI. The patient responded to desmopressin and completely recovered five days after surgery. It is probable that transient cerebral ischemia resulted in the dysfunction of osmotic receptors in the hypothalamus or hypothalamus-pituitary axis during CPB. It is also possible that cardiac standstill altered the left atrial non-osmotic receptor function and suppressed ADH release. Therefore, we suggest that central DI is a possible cause of polyuria after CPB.

A Case of Transient Central Diabetes Insipidus after Aorto-Coronary Bypass Operation

PubMed Central

Yu, Chung-Hoon; Cho, Jang-Hee; Jung, Hee-Yeon; Lim, Jeong-Hoon; Jin, Mi-Kyung; Kwon, Owen; Hong, Kyung-Deuk; Choi, Ji-Young; Yoon, Se-Hee; Kim, Chan-Duck; Kim, Yong-Lim; Kim, Gun-Jik

2012-01-01

Diabetes insipidus (DI) is characterized by excessive urination and thirst. This disease results from inadequate output of antidiuretic hormone (ADH) from the pituitary gland or the absence of the normal response to ADH in the kidney. We present a case of transient central DI in a patient who underwent a cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG). A 44-yr-old male underwent a CABG operation. An hour after the operation, the patient developed polyuria and was diagnosed with central DI. The patient responded to desmopressin and completely recovered five days after surgery. It is probable that transient cerebral ischemia resulted in the dysfunction of osmotic receptors in the hypothalamus or hypothalamus-pituitary axis during CPB. It is also possible that cardiac standstill altered the left atrial non-osmotic receptor function and suppressed ADH release. Therefore, we suggest that central DI is a possible cause of polyuria after CPB. PMID:22969261

Parameter Transient Behavior Analysis on Fault Tolerant Control System

NASA Technical Reports Server (NTRS)

Belcastro, Christine (Technical Monitor); Shin, Jong-Yeob

2003-01-01

In a fault tolerant control (FTC) system, a parameter varying FTC law is reconfigured based on fault parameters estimated by fault detection and isolation (FDI) modules. FDI modules require some time to detect fault occurrences in aero-vehicle dynamics. This paper illustrates analysis of a FTC system based on estimated fault parameter transient behavior which may include false fault detections during a short time interval. Using Lyapunov function analysis, the upper bound of an induced-L2 norm of the FTC system performance is calculated as a function of a fault detection time and the exponential decay rate of the Lyapunov function.

Usefulness of left ventricular speckle tracking echocardiography and novel measures of left atrial structure and function in diagnosing paroxysmal atrial fibrillation in ischemic stroke and transient ischemic attack patients.

PubMed

Skaarup, Kristoffer Grundtvig; Christensen, Hanne; Høst, Nis; Mahmoud, Masti Mahdy; Ovesen, Christian; Olsen, Flemming Javier; Jensen, Jan Skov; Biering-Sørensen, Tor

2017-12-01

Asymptomatic paroxysmal atrial fibrillation (PAF) is often assumed to be the cause of cryptogenic ischemic strokes (IS) and transient ischemic attacks (TIA). We examined the usefulness of measures obtained by 2D speckle tracking echocardiography and novel left atrial measurements, in the diagnosis of PAF in patients with IS and TIA. We retrospectively included 205 patients who after acute IS or TIA underwent an echocardiogram in sinus rhythm. Patients were designated as PAF-patients if they had one or more reported incidents of AF before or after their echocardiographic examination. None of the conventional echocardiographic parameters were significantly associated with PAF. Of the speckle tracking measurements, only early diastolic strain rate (0.7±0.2 s -1 vs. 0.8±0.3 s -1 , p = 0.048) and global longitudinal displacement (GLD) (3.15 ± 1.40 mm vs. 3.87 ± 1.56 mm, p = 0.007) proved significantly different. Of the left atrial parameters both minimal and maximal left atrium volume divided by left ventricular length (min LAV/LVL and max LAV/LVL, respectively) were significantly impaired (min LAV/LVL: 3.7 ± 2.1 cm 2 vs. 2.8 ± 1.11 cm 2 , p = 0.012; max LAV/LVL: 6.6 ± 3.1 cm 2 vs. 5.6 ± 1.7 cm 2 , p = 0.012). GLD, min max LAV/LVL proved significant after adjustment for age, gender, CHA 2 DS 2 -VASc and NIHSS. By combining information regarding age, GLD, min and max LAV/LVL the diagnostic accuracy of PAF improved, resulting in a significantly increased area under the curve (p = 0.037). In patients with IS and TIA GLD, min and max LAV/LVL were independently associated with the presence of PAF.

Electrical and Optical Studies of Deep Levels in Nominally Undoped Thallium Bromide

NASA Astrophysics Data System (ADS)

Smith, Holland M.; Haegel, Nancy M.; Phillips, David J.; Cirignano, Leonard; Ciampi, Guido; Kim, Hadong; Chrzan, Daryl C.; Haller, Eugene E.

2014-02-01

Photo-induced conductivity transient spectroscopy (PICTS) and cathodoluminescence (CL) measurements were performed on nominally undoped detector grade samples of TlBr. In PICTS measurements, nine traps were detected in the temperature range 80-250 K using four-gate analysis. Five of the traps are tentatively identified as electron traps, and four as hole traps. CL measurements yielded two broad peaks common to all samples and most likely associated with defects. Correlations between the optically and electrically detected deep levels are considered. Above 250 K, the photoconductivity transients measured in the PICTS experiments exhibited anomalous transient behavior, indicated by non-monotonic slope variations as a function of time. The origin of the transients is under further investigation, but their presence precludes the accurate determination of trap parameters in TlBr above 250 K with traditional PICTS analysis. Their discovery was made possible by the use of a PICTS system that records whole photoconductivity transients, as opposed to reduced and processed signals.

Fast, transient and specific intracellular ROS changes in living root hair cells responding to Nod factors (NFs).

PubMed

Cárdenas, Luis; Martínez, Adán; Sánchez, Federico; Quinto, Carmen

2008-12-01

The role of reactive oxygen species (ROS) in root-nodule development and metabolism has been extensively studied. However, there is limited evidence showing ROS changes during the earliest stages of the interaction between legumes and rhizobia. Herein, using ratio-imaging analysis, increasing and transient ROS levels were detected at the tips of actively growing root hair cells within seconds after addition of Nod factors (NFs). This transient response (which lasted up to 3 min) was Nod-factor-specific, as chitin oligomers (pentamers) failed to induce a similar response. When chitosan, a fungal elicitor, or ATP was used instead, a sustained increasing signal was observed. As ROS levels are transiently elevated after the perception of NFs, we propose that this ROS response is characteristic of the symbiotic interaction. Furthermore, we discuss the remarkable spatial and temporal coincidences between ROS and transiently increased calcium levels observed in root hair cells immediately after the detection of NFs.

EXTraS unveils a supernova shock break-out candidate in XMM-Newton archival data

NASA Astrophysics Data System (ADS)

Tiengo, A.; Novara, G.; Lisini, G.; De Luca, A.; Salvaterra, R.; Belfiore, A.; Marelli, M.; Salvetti, D.; Mereghetti, S.; Vianello, G.

2017-10-01

During the search for short X-ray transients within the Exploring the X-ray Transient and variable Sky (EXTraS) project, we discovered a new X-ray source that can be detected only in a ˜5 minutes interval of a ˜21 hours long XMM-Newton observation. Thanks to dedicated follow-up observations, we found that its position is consistent with a galaxy at redshift z=0.092. At this redshift, the transient released 2×10^{46} erg in the 0.3-10 keV energy band. Its luminosity and spectral and timing properties make it an analogue of the X-ray transient associated to SN2008, detected by Swift/XRT during an observation of the nearby supernova-rich galaxy NGC 2770. The discovery of this much more distant transient in a field galaxy during a systematic analysis of the full XMM-Newton archive allows us to better constrain the rate of these rare events.

Interpreting signals from astrophysical transient experiments.

PubMed

O'Brien, Paul T; Smartt, Stephen J

2013-06-13

Time-domain astronomy has come of age with astronomers now able to monitor the sky at high cadence, both across the electromagnetic spectrum and using neutrinos and gravitational waves. The advent of new observing facilities permits new science, but the ever-increasing throughput of facilities demands efficient communication of coincident detections and better subsequent coordination among the scientific community so as to turn detections into scientific discoveries. To discuss the revolution occurring in our ability to monitor the Universe and the challenges it brings, on 25-26 April 2012, a group of scientists from observational and theoretical teams studying transients met with representatives of the major international transient observing facilities at the Kavli Royal Society International Centre, UK. This immediately followed the Royal Society Discussion Meeting 'New windows on transients across the Universe' held in London. Here, we present a summary of the Kavli meeting at which the participants discussed the science goals common to the transient astronomy community and analysed how to better meet the challenges ahead as ever more powerful observational facilities come on stream.

Electrical velocimetry for non-invasive monitoring of the closure of the ductus arteriosus in preterm infants.

PubMed

Rodríguez Sánchez de la Blanca, Ana; Sánchez Luna, M; González Pacheco, N; Arriaga Redondo, M; Navarro Patiño, N

2018-02-01

Closure of a patent ductus arteriosus (PDA) in preterm infants modifies cardiac output and induces adaptive changes in the hemodynamic situation. The present study aims to analyze those changes, through a non-invasive cardiac output monitor based on blood electrical velocimetry, in preterm babies. A prospective observational study of preterm infants with a gestational age of less than 28 weeks, and a hemodynamic significant PDA, requires intravenous ibuprofen or surgical closure. All patients were monitored with electrical velocimetry before treatment and through the following 72 h. Two groups were defined, ibuprofen and surgical closure. Variations of cardiac output were analyzed from the basal situation and at 1, 8, 24, 48, and 72 h on each group. During a 12-month period, 18 patients were studied. The median gestational age in the ibuprofen group (12/18) was 26 +5  weeks (25 +5 -27 +3 ) with a median birth weight of 875 (670-1010) g. The cardiac output index (CI) value was 0.29 l/kg/min (0.24-0.34). Among the patients with confirmed ductus closure (50%), a significant CI decrease was shown (0.24 vs 0.29 l/kg/min; P 0.03) after 72 h (three ibuprofen doses). A statistically significant decrease in systolic volume (SVI) was found: 1.62 vs 1.88 ml/kg, P 0.03 with a decrease in contractility (ICON), 85 vs 140, P 0.02. The gestational age in the surgical group (6/18) was 25 +2  weeks (24-26 +3 ) with a median weight of 745 (660-820) g. All patients in this group showed a decrease in the immediate postoperative CI (1 h after surgery) 0.24 vs 0.30 l/kg/min, P 0.05, and a significant decrease in contractility (ICON 77 vs 147, P 0.03). In addition, a no statistically significant decrease in SVI (1.54 vs 1.83 ml/kg, P 0.06), as well as an increase in systemic vascular resistance (10,615 vs 8797 dyn/cm 2 , P 0.08), were detected. This deterioration was transient without significant differences in the remaining periods of time evaluated. The surgical closure of the PDA in preterm infants causes a transient deterioration of cardiac function linked to a documented decrease in the left ventricular output. The hemodynamic changes detected after pharmacological PDA closure are similar but those patients present a better clinical tolerance to changes in the cardiac output. What is Known: • Surgical ductus closure generates acute hemodynamic changes in cardiac output and left ventricular function. What is New: • The hemodynamic changes detected after pharmacological ductus closure are similar to those found in the surgical closure. Electrical velocimetry can detect those changes.

Silent Aortic Dissection Presenting as Transient Locked-In Syndrome

PubMed Central

Nadour, Wadih; Goldwasser, Brian; Biederman, Robert W.; Taffe, Kevin

2008-01-01

Acute aortic dissection is a medical emergency. Without prompt recognition and treatment, the mortality rate is high. An atypical presentation makes timely diagnosis difficult, especially if the patient is experiencing no characteristic pain. Many patients with aortic dissection are reported to have presented with various neurologic manifestations, but none with only a presentation of transient locked-in syndrome. Herein, we report a case of completely painless aortic dissection in a woman who presented with a transient episode of anarthria, quadriplegia, and preserved consciousness. On physical examination, she had a 40-point difference in blood pressure between her left and right arms, and a loud diastolic murmur. The diagnosis of acute aortic dissection was reached via a combination of radiography, computed tomography, echocardiography, and a high index of clinical suspicion. The patient underwent emergency surgery and ultimately experienced a successful outcome. To our knowledge, this is the 1st report of aortic dissection that presented solely as locked-in syndrome. We suggest that silent aortic dissection be added to the differential diagnosis for transient locked-in syndrome. PMID:18941610

Capture-recapture survival models taking account of transients

USGS Publications Warehouse

Pradel, R.; Hines, J.E.; Lebreton, J.D.; Nichols, J.D.

1997-01-01

The presence of transient animals, common enough in natural populations, invalidates the estimation of survival by traditional capture- recapture (CR) models designed for the study of residents only. Also, the study of transit is interesting in itself. We thus develop here a class of CR models to describe the presence of transients. In order to assess the merits of this approach we examme the bias of the traditional survival estimators in the presence of transients in relation to the power of different tests for detecting transients. We also compare the relative efficiency of an ad hoc approach to dealing with transients that leaves out the first observation of each animal. We then study a real example using lazuli bunting (Passerina amoena) and, in conclusion, discuss the design of an experiment aiming at the estimation of transience. In practice, the presence of transients is easily detected whenever the risk of bias is high. The ad hoc approach, which yields unbiased estimates for residents only, is satisfactory in a time-dependent context but poorly efficient when parameters are constant. The example shows that intermediate situations between strict 'residence' and strict 'transience' may exist in certain studies. Yet, most of the time, if the study design takes into account the expected length of stay of a transient, it should be possible to efficiently separate the two categories of animals.

A Patch-Based Method for Repetitive and Transient Event Detection in Fluorescence Imaging

PubMed Central

Boulanger, Jérôme; Gidon, Alexandre; Kervran, Charles; Salamero, Jean

2010-01-01

Automatic detection and characterization of molecular behavior in large data sets obtained by fast imaging in advanced light microscopy become key issues to decipher the dynamic architectures and their coordination in the living cell. Automatic quantification of the number of sudden and transient events observed in fluorescence microscopy is discussed in this paper. We propose a calibrated method based on the comparison of image patches expected to distinguish sudden appearing/vanishing fluorescent spots from other motion behaviors such as lateral movements. We analyze the performances of two statistical control procedures and compare the proposed approach to a frame difference approach using the same controls on a benchmark of synthetic image sequences. We have then selected a molecular model related to membrane trafficking and considered real image sequences obtained in cells stably expressing an endocytic-recycling trans-membrane protein, the Langerin-YFP, for validation. With this model, we targeted the efficient detection of fast and transient local fluorescence concentration arising in image sequences from a data base provided by two different microscopy modalities, wide field (WF) video microscopy using maximum intensity projection along the axial direction and total internal reflection fluorescence microscopy. Finally, the proposed detection method is briefly used to statistically explore the effect of several perturbations on the rate of transient events detected on the pilot biological model. PMID:20976222

Transient and sustained neural responses to death-related linguistic cues

PubMed Central

Shi, Zhenhao

2013-01-01

Recent research showed that perception of death-related vs death-unrelated linguistic cues produced increased frontoparietal activity but decreased insular activity. This study investigated (i) whether the increased frontoparietal and decreased insular activities are, respectively, associated with transient trial-specific processes of death-related linguistic cues and sustained death-related thought during death-relevance judgments on linguistic cues and (ii) whether the neural activity underlying death-related thought can predict individuals’ dispositional death anxiety. Participants were presented with death-related/unrelated words, life-related/unrelated words, and negative-valence/neutral words in separate sessions. Participants were scanned using functional magnetic resonance imaging while performing death-relevance, life-relevance, and valence judgments on the words, respectively. The contrast of death-related vs death-unrelated words during death-relevance judgments revealed transient increased activity in the left inferior parietal lobule, the right frontal eye field, and the right superior parietal lobule. The contrast of death-relevance judgments vs life-relevance/valence judgments showed decreased activity in the bilateral insula. The sustained insular activity was correlated with dispositional death anxiety, but only in those with weak transient frontoparietal responses to death-related words. Our results dissociate the transient and sustained neural responses to death-related linguistic cues and suggest that the combination of the transient and sustained neural activities can predict dispositional death anxiety. PMID:22422804

Transient Events in Archival Very Large Array Observations of the Galactic Center

NASA Astrophysics Data System (ADS)

Chiti, Anirudh; Chatterjee, Shami; Wharton, Robert; Cordes, James; Lazio, T. Joseph W.; Kaplan, David L.; Bower, Geoffrey C.; Croft, Steve

2016-12-01

The Galactic center has some of the highest stellar densities in the Galaxy and a range of interstellar scattering properties, which may aid in the detection of new radio-selected transient events. Here, we describe a search for radio transients in the Galactic center, using over 200 hr of archival data from the Very Large Array at 5 and 8.4 GHz. Every observation of Sgr A* from 1985 to 2005 has been searched using an automated processing and detection pipeline sensitive to transients with timescales between 30 s and 5 minutes with a typical detection threshold of ˜100 mJy. Eight possible candidates pass tests to filter false-positives from radio-frequency interference, calibration errors, and imaging artifacts. Two events are identified as promising candidates based on the smoothness of their light curves. Despite the high quality of their light curves, these detections remain suspect due to evidence of incomplete subtraction of the complex structure in the Galactic center, and apparent contingency of one detection on reduction routines. Events of this intensity (˜100 mJy) and duration (˜100 s) are not obviously associated with known astrophysical sources, and no counterparts are found in data at other wavelengths. We consider potential sources, including Galactic center pulsars, dwarf stars, sources like GCRT J1745-3009, and bursts from X-ray binaries. None can fully explain the observed transients, suggesting either a new astrophysical source or a subtle imaging artifact. More sensitive multiwavelength studies are necessary to characterize these events, which, if real, occur with a rate of {14}-12+32 {{hr}}-1 {\\deg }-2 in the Galactic center.

RAPTOR: Closed-Loop monitoring of the night sky and the earliest optical detection of GRB 021211

NASA Astrophysics Data System (ADS)

Vestrand, W. T.; Borozdin, K.; Casperson, D. J.; Fenimore, E.; Galassi, M.; McGowan, K.; Starr, D.; White, R. R.; Wozniak, P.; Wren, J.

2004-10-01

We discuss the RAPTOR (Rapid Telescopes for Optical Response) sky monitoring system at Los Alamos National Laboratory. RAPTOR is a fully autonomous robotic system that is designed to identify and make follow-up observations of optical transients with durations as short as one minute. The RAPTOR design is based on Biomimicry of Human Vision. The sky monitor is composed of two identical arrays of telescopes, separated by 38 kilometers, which stereoscopically monitor a field of about 1300 square-degrees for transients. Both monitoring arrays are carried on rapidly slewing mounts and are composed of an ensemble of wide-field telescopes clustered around a more powerful narrow-field telescope called the ``fovea'' telescope. All telescopes are coupled to real-time analysis pipelines that identify candidate transients and relay the information to a central decision unit that filters the candidates to find real celestial transients and command a response. When a celestial transient is found, the system can point the fovea telescopes to any position on the sky within five seconds and begin follow-up observations. RAPTOR also responds to Gamma Ray Burst (GRB) alerts generated by GRB monitoring spacecraft. Here we present RAPTOR observations of GRB 021211 that constitute the earliest detection of optical emission from that event and are the second fastest achieved for any GRB. The detection of bright optical emission from GRB021211, a burst with modest gamma-ray fluence, indicates that prompt optical emission, detectable with small robotic telescopes, is more common than previously thought. Further, the very fast decline of the optical afterglow from GRB 021211 suggests that some so-called ``optically dark'' GRBs were not detected only because of the slow response of the follow-up telescopes.

Non-invasive measurement of liver and pancreas fibrosis in patients with cystic fibrosis.

PubMed

Friedrich-Rust, Mireen; Schlueter, Nina; Smaczny, Christina; Eickmeier, Olaf; Rosewich, Martin; Feifel, Kirstin; Herrmann, Eva; Poynard, Thierry; Gleiber, Wolfgang; Lais, Christoph; Zielen, Stefan; Wagner, Thomas O F; Zeuzem, Stefan; Bojunga, Joerg

2013-09-01

Patients with cystic fibrosis (CF) have a relevant morbidity and mortality caused by CF-related liver-disease. While transient elastography (TE) is an established elastography method in hepatology centers, Acoustic-Radiation-Force-Impulse (ARFI)-Imaging is a novel ultrasound-based elastography method which is integrated in a conventional ultrasound-system. The aim of the present study was to evaluate the prevalence of liver-fibrosis in patients with CF using TE, ARFI-imaging and fibrosis blood tests. 106 patients with CF were prospectively included in the present study and received ARFI-imaging of the left and right liver-lobe, ARFI of the pancreas TE of the liver and laboratory evaluation. The prevalence of liver-fibrosis according to recently published best practice guidelines for CFLD was 22.6%. Prevalence of significant liver-fibrosis assessed by TE, ARFI-right-liver-lobe, ARFI-left-liver-lobe, Fibrotest, Fibrotest-corrected-by-haptoglobin was 17%, 24%, 40%, 7%, and 16%, respectively. The best agreement was found for TE, ARFI-right-liver-lobe and Fibrotest-corrected-by-haptoglobin. Patients with pancreatic-insufficiency had significantly lower pancreas-ARFI-values as compared to patients without. ARFI-imaging and TE seem to be promising non-invasive methods for detection of liver-fibrosis in patients with CF. Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Unveiling the population of orphan γ-ray bursts

NASA Astrophysics Data System (ADS)

Ghirlanda, G.; Salvaterra, R.; Campana, S.; Vergani, S. D.; Japelj, J.; Bernardini, M. G.; Burlon, D.; D'Avanzo, P.; Melandri, A.; Gomboc, A.; Nappo, F.; Paladini, R.; Pescalli, A.; Salafia, O. S.; Tagliaferri, G.

2015-06-01

Gamma-ray bursts (GRBs) are detectable in the γ-ray band if their jets are oriented toward the observer. However, for each GRB with a typical θjet, there should be ~2/θ2jet bursts whose emission cone is oriented elsewhere in space. These off-axis bursts can eventually be detected when, due to the deceleration of their relativistic jets, the beaming angle becomes comparable to the viewing angle. Orphan afterglows (OAs) should outnumber the current population of bursts detected in the γ-ray band even if they have not been conclusively observed so far at any frequency. We compute the expected flux of the population of orphan afterglows in the mm, optical, and X-ray bands through a population synthesis code of GRBs and the standard afterglow emission model. We estimate the detection rate of OAs with ongoing and forthcoming surveys. The average duration of OAs as transients above a given limiting flux is derived and described with analytical expressions: in general OAs should appear as daily transients in optical surveys and as monthly/yearly transients in the mm/radio band. We find that ~2 OA yr-1 could already be detected by Gaia and up to 20 OA yr-1 could be observed by the ZTF survey. A larger number of 50 OA yr-1 should be detected by LSST in the optical band. For the X-ray band, ~26 OA yr-1 could be detected by the eROSITA. For the large population of OA detectable by LSST, the X-ray and optical follow up of the light curve (for the brightest cases) and/or the extensive follow up of their emission in the mm and radio band could be the key to disentangling their GRB nature from other extragalactic transients of comparable flux density.

Temperature Rise Induced by a Rotating/Dithering Laser Beam on a Finite Solid

DTIC Science & Technology

2010-12-01

selected point. 98 THIS PAGE INTENTIONALLY LEFT BLANK 99 LIST OF REFERENCES [1] G. Araya , and G. Gutierrez, “Analytical solution for a transient... 2006 . [2] J. E. Moody and R. H. Hendel, “Temperature profiles induced by a scanning cw laser beam,” Journal of Applied Physics, vol. 53(6), pp

High Throughput Screen to Identify Novel Drugs that Inhibit Prostate Cancer Metastasis

DTIC Science & Technology

2005-10-01

mutants of the SSeCKS α promoter fused to luciferase reporter cassettes (left) were transiently expressed along with pRL-TK- renilla in either P69 or...DU145 cells, and the resulting luciferase activity was normalized to that of renilla activity. Figure 3. Semi quantitative RT-PCR of SSeCKS (either

Real-time detection and data acquisition system for the left ventricular outline. Ph.D. Thesis - Stanford Univ.

NASA Technical Reports Server (NTRS)

Reiber, J. H. C.

1976-01-01

To automate the data acquisition procedure, a real-time contour detection and data acquisition system for the left ventricular outline was developed using video techniques. The X-ray image of the contrast-filled left ventricle is stored for subsequent processing on film (cineangiogram), video tape or disc. The cineangiogram is converted into video format using a television camera. The video signal from either the TV camera, video tape or disc is the input signal to the system. The contour detection is based on a dynamic thresholding technique. Since the left ventricular outline is a smooth continuous function, for each contour side a narrow expectation window is defined in which the next borderpoint will be detected. A computer interface was designed and built for the online acquisition of the coordinates using a PDP-12 computer. The advantage of this system over other available systems is its potential for online, real-time acquisition of the left ventricular size and shape during angiocardiography.

Functional magnetic resonance imaging to determine hemispheric language dominance prior to carotid endarterectomy.

PubMed

Smits, M; Wieberdink, R G; Bakker, S L M; Dippel, D W J

2011-04-01

We describe a left-handed patient with transient aphasia and bilateral carotid stenosis. Computed tomography (CT) arteriography showed a 90% stenosis of the right and 30% stenosis of the left internal carotid artery. Head CT and magnetic resonance imaging (MRI) of the brain showed no recent ischemic changes. As only the symptomatic side would require surgical intervention, and because hemispheric dominance for language in left-handed patients may be either left or right sided, a preoperative assessment of hemispheric dominance was required. We used functional MRI to determine hemispheric dominance for language and hence to establish the indication for carotid endarterectomy surgery. Functional MRI demonstrated right hemispheric dominance for language and right-sided carotid endarterectomy was performed. We propose that the clinical use of functional MRI as a noninvasive imaging technique for the assessment of hemispheric language dominance may be extended to the assessment of hemispheric language dominance prior to carotid endarterectomy. Copyright © 2010 by the American Society of Neuroimaging.

Visual and auditory accessory stimulus offset and the Simon effect.

PubMed

Nishimura, Akio; Yokosawa, Kazuhiko

2010-10-01

We investigated the effect on the right and left responses of the disappearance of a task-irrelevant stimulus located on the right or left side. Participants pressed a right or left response key on the basis of the color of a centrally located visual target. Visual (Experiment 1) or auditory (Experiment 2) task-irrelevant accessory stimuli appeared or disappeared at locations to the right or left of the central target. In Experiment 1, responses were faster when onset or offset of the visual accessory stimulus was spatially congruent with the response. In Experiment 2, responses were again faster when onset of the auditory accessory stimulus and the response were on the same side. However, responses were slightly slower when offset of the auditory accessory stimulus and the response were on the same side than when they were on opposite sides. These findings indicate that transient change information is crucial for a visual Simon effect, whereas sustained stimulation from an ongoing stimulus also contributes to an auditory Simon effect.

Long-term efficacy of linear-scanning 808 nm diode laser for hair removal compared to a scanned alexandrite laser.

PubMed

Grunewald, Sonja; Bodendorf, Marc Oliver; Zygouris, Alexander; Simon, Jan Christoph; Paasch, Uwe

2014-01-01

Alexandrite and diode lasers are commonly used for hair removal. To date, the available spot sizes and repetition rates are defining factors in terms of penetration depth, treatment speed, and efficacy. Still, larger treatment areas and faster systems are desirable. To compare the efficacy, tolerability, and subject satisfaction of a continuously linear-scanning 808 nm diode laser with an alexandrite 755 nm laser for axillary hair removal. A total of 31 adults with skin types I-IV received 6 treatments at 4-week intervals with a 755 nm alexandrite laser (right axilla) and a continuously linear-scanning 808 nm diode laser (left axilla). Axillary hair density was assessed using a computerized hair detection system. There was a significant reduction in axillary hair after the 6th treatment (P < 0.05) on both sides (left, 808 nm: hair clearance of 72.16%; right, 755 nm: hair clearance of 71.30%). The difference in reduction between the two lasers was not significant, but both were persistant at 18 months follow-up (left: hair clearance of 73.71%; right: hair clearance of 71.90%). Erythema and perifollicular edema were more common after alexandrite laser treatment, but all side effects were transient. While 62.50% of patients reported more pain in response to treatment with the new diode laser, all patients rated treatment with either laser tolerable. Treatment with either the alexandrite or the linear-scanning diode laser results in significant, comparable, persistent (at least 18 months) axillary hair reduction among individuals with skin types I-IV. © 2013 Wiley Periodicals, Inc.

Study on the Relationships between Intrinsic Functional Connectivity of the Default Mode Network and Transient Epileptic Activity.

PubMed

Lopes, Renaud; Moeller, Friederike; Besson, Pierre; Ogez, François; Szurhaj, William; Leclerc, Xavier; Siniatchkin, Michael; Chipaux, Mathilde; Derambure, Philippe; Tyvaert, Louise

2014-01-01

Simultaneous recording of electroencephalogram and functional MRI (EEG-fMRI) is a powerful tool for localizing epileptic networks via the detection of hemodynamic changes correlated with interictal epileptic discharges (IEDs). fMRI can be used to study the long-lasting effect of epileptic activity by assessing stationary functional connectivity during the resting-state period [especially, the connectivity of the default mode network (DMN)]. Temporal lobe epilepsy (TLE) and idiopathic generalized epilepsy (IGE) are associated with low responsiveness and disruption of DMN activity. A dynamic functional connectivity approach might enable us to determine the effect of IEDs on DMN connectivity and to better understand the correlation between DMN connectivity changes and altered consciousness. We studied dynamic changes in DMN intrinsic connectivity and their relation to IEDs. Six IGE patients (with generalized spike and slow-waves) and 6 TLE patients (with unilateral left temporal spikes) were included. Functional connectivity before, during, and after IEDs was estimated using a sliding window approach and compared with the baseline period. No dependence on window size was observed. The baseline DMN connectivity was decreased in the left hemisphere (ipsilateral to the epileptic focus) in TLEs and was less strong but remained bilateral in IGEs. We observed an overall increase in DMN intrinsic connectivity prior to the onset of IEDs in both IGEs and TLEs. After IEDs in TLEs, we found that DMN connectivity increased before it returned to baseline values. Most of the DMN regions with increased connectivity before and after IEDs were lateralized to the left hemisphere in TLE (i.e., ipsilateral to the epileptic focus). RESULTS suggest that DMN connectivity may facilitate IED generation and may be affected at the time of the IED. However, these results need to be confirmed in a larger independent cohort.

Transient Amaurosis and Diplopia After Inferior Alveolar Nerve Block.

PubMed

Odabaşi, Onur; Şahin, Onur; Polat, Mehmet Emrah

2017-10-01

A 40-year-old female patient was admitted to the authors' oral and maxillofacial clinic for removal of her lower left second molar under local anesthesia. The patient's medical history revealed that she had cardiac arhythmia and hypertension. Inferior alveolar nerve block was achieved using 2 mL of sefacaine (%3 mepivacaine HCL, without epinephrine). The patient complained of loss of vision in her left eye. All procedures were stopped immediately. Within 2 minutes the patient reported diplopia. All of the symptoms disappeared about 5 minutes after initial observation. Follow-up after 1 day revealed no complications. The procedure was then performed uneventfully.

Risk of advanced heart block during extradural anaesthesia in patients with right bundle branch block and left anterior hemiblock.

PubMed

Coriat, P; Harari, A; Ducardonet, A; Tarot, J P; Viars, P

1981-05-01

Electrocardiographic recording by Holter monitoring demonstrated the absence of any modification, however minimal, of the intranodal conduction during surgical procedures under extradural anaesthesia in 20 patients with right bundle branch block (RBBB) and left anterior hemiblock (LAHB) but without symptoms. These data suggest that extradural anaesthesia can be used safely in patients with asymptomatic chronic RBBB and LAHB without prophylactic insertion of pacemakers. However, patients having experienced either syncope or transient Mobitz II second degree AV block are likely to have a trifascicular block and increased risk of advanced heart block during extradural anaesthesia.

Bilateral medial medullary infarction due to bilateral vertebral artery dissection.

PubMed

Fukuda, Masafumi; Aiba, Toyotaka; Takahashi, Sho

2004-03-01

We describe a 52-year-old woman who experienced transient motor weakness and numbness of the left extremities and presented 2 days later with severe hemiparesis and sensory impairment of the right extremities and right lingual palsy. Magnetic resonance imaging (MRI) revealed bilateral upper medial medullary infarction, primarily in the left ventral portion. The findings of both three-dimensional (3D) computed tomographic and conventional angiography suggested dissection of both intracranial vertebral arteries (VAs). Medial medullary infarction is generally caused by atherosclerosis within a VA or anterior spinal artery. This is the first report of bilateral medial medullary infarction due to dissection of both intracranial VAs.

OPTICAL THERMONUCLEAR TRANSIENTS FROM TIDAL COMPRESSION OF WHITE DWARFS AS TRACERS OF THE LOW END OF THE MASSIVE BLACK HOLE MASS FUNCTION

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

MacLeod, Morgan; Ramirez-Ruiz, Enrico; Guillochon, James

In this paper, we model the observable signatures of tidal disruptions of white dwarf (WD) stars using massive black holes (MBHs) of moderate mass, ≈10{sup 3}–10{sup 5} M{sub ⊙}. When the WD passes deep enough within the MBH’s tidal field, these signatures include thermonuclear transients from burning during maximum compression. We combine a hydrodynamic simulation that includes nuclear burning of the disruption of a 0.6 M{sub ⊙} C/O WD with a Monte Carlo radiative transfer calculation to synthesize the properties of a representative transient. The transient’s emission emerges in the optical, with light curves and spectra reminiscent of Type I supernovae. Themore » properties are strongly viewing angle dependent, and key spectral signatures are ≈10,000 km s{sup −1} doppler shifts, due to the orbital motion of the unbound ejecta. Disruptions of He WDs likely produce large quantities of intermediate-mass elements, offering a possible production mechanism for Ca-rich transients. Accompanying multi-wavelength transients are fueled by accretion and arise from the nascent accretion disk and relativistic jet. If MBHs of moderate mass exist with number densities similar to those of supermassive BHs, both high-energy wide-field monitors and upcoming optical surveys should detect tens to hundreds of WD tidal disruptions per year. The current best strategy for their detection may therefore be deep optical follow-up of high-energy transients of unusually long duration. The detection rate or the nondetection of these transients by current and upcoming surveys can thus be used to place meaningful constraints on the extrapolation of the MBH mass function to moderate masses.« less

The Unprecedented Properties of the First Electromagnetic Counterpart to a Gravitational-wave Source

NASA Astrophysics Data System (ADS)

Siebert, M. R.; Foley, R. J.; Drout, M. R.; Kilpatrick, C. D.; Shappee, B. J.; Coulter, D. A.; Kasen, D.; Madore, B. F.; Murguia-Berthier, A.; Pan, Y.-C.; Piro, A. L.; Prochaska, J. X.; Ramirez-Ruiz, E.; Rest, A.; Contreras, C.; Morrell, N.; Rojas-Bravo, C.; Simon, J. D.

2017-10-01

We discovered Swope Supernova Survey 2017a (SSS17a) in the LIGO/Virgo Collaboration (LVC) localization volume of GW170817, the first detected binary neutron star (BNS) merger, only 10.9 hr after the trigger. No object was present at the location of SSS17a only a few days earlier, providing a qualitative spatial and temporal association with GW170817. Here, we quantify this association, finding that SSS17a is almost certainly the counterpart of GW170817, with the chance of a coincidence being ≤9× {10}-6 (90% confidence). We arrive at this conclusion by comparing the optical properties of SSS17a to other known astrophysical transients, finding that SSS17a fades and cools faster than any other observed transient. For instance, SSS17a fades >5 mag in g within 7 days of our first data point, while all other known transients of similar luminosity fade by <1 mag during the same time period. Its spectra are also unique, being mostly featureless, even as it cools. The rarity of “SSS17a-like” transients combined with the relatively small LVC localization volume and recent non-detection imply the extremely unlikely chance coincidence. We find that the volumetric rate of SSS17a-like transients is ≤1.6× {10}4 Gpc-3 yr-1 and the Milky Way rate is ≤slant 0.19 per century. A transient survey designed to discover similar events should be high cadence and observe in red filters. The LVC will likely detect substantially more BNS mergers than current optical surveys will independently discover SSS17a-like transients, however a 1 day cadence survey with the Large Synoptic Survey Telescope (LSST) could discover an order of magnitude more events.

Real-time Transients from Palomar-QUEST Synoptic Sky Survey

NASA Astrophysics Data System (ADS)

Mahabal, Ashish A.; Drake, A.; Djorgovski, S. G.; Donalek, C.; Glikman, E.; Graham, M. J.; Williams, R.; Baltay, C.; Rabinowitz, D.; Bauer, A.; Ellman, N.; Lauer, R.; PQ Team Indiana

2006-12-01

The data from the driftscans of the Palomar-QUEST synoptic sky survey is now routinely processed in real-time. We describe here the various components of the pipeline. We search for both variable and transient objects, including supernovae, variable AGN, GRB orphan afterglows, cataclysmic variables, interesting stellar flares, novae, other types of variable stars, and do not exclude the possibility of even entirely new types of objects or phenomena. In order to flag as many asteroids as possible we have been doing two 4-hour scans of the same area covering 250 sq. deg and detect over a million sources. Flagging a source as a candidate transient requires detection in at least two filters besides its absence in fiducial sky constructed from past images. We use various software filters to eliminate instrument artifacts, and false alarms due to the proximity of bright, saturated stars which dominate the initial detection rate. This leaves up to a couple of hundred asteroids and genuine transients. Previously known asteroids are flagged through an automated comparison with a databases of known asteroids, and new ones through apparent motion. In the end, we have typically 10 20 astrophysical transients remaining per night, and we are currently working on their automated classification, and spectroscopic follow-up. We present preliminary results from real-time follow-up of a few candidates carried out with the Palomar 200-inch telescope as part of a pilot project. Finally we outline the plans for the much harder problem of classifying the transients more accurately for distribution through VOEventNet to astronomers interested only in specific types of transients, more details and overall setting of which is covered in our VOEventNet poster (Drake et al.)

Follow-up of high energy neutrinos detected by the ANTARES telescope

NASA Astrophysics Data System (ADS)

Mathieu, Aurore

2016-04-01

The ANTARES telescope is well-suited to detect high energy neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky with a high duty cycle. Potential neutrino sources are gamma-ray bursts, core-collapse supernovae and flaring active galactic nuclei. To enhance the sensitivity of ANTARES to such sources, a detection method based on follow-up observations from the neutrino direction has been developed. This program, denoted as TAToO, includes a network of robotic optical telescopes (TAROT, Zadko and MASTER) and the Swift-XRT telescope, which are triggered when an "interesting" neutrino is detected by ANTARES. A follow-up of special events, such as neutrino doublets in time/space coincidence or a single neutrino having a very high energy or in the specific direction of a local galaxy, significantly improves the perspective for the detection of transient sources. The analysis of early and long term follow-up observations to search for fast and slowly varying transient sources, respectively, has been performed and the results covering optical and X-ray data are presented in this contribution.

Detecting Thermal Cloaks via Transient Effects

PubMed Central

Sklan, Sophia R.; Bai, Xue; Li, Baowen; Zhang, Xiang

2016-01-01

Recent research on the development of a thermal cloak has concentrated on engineering an inhomogeneous thermal conductivity and an approximate, homogeneous volumetric heat capacity. While the perfect cloak of inhomogeneous κ and inhomogeneous ρcp is known to be exact (no signals scattering and only mean values penetrating to the cloak’s interior), the sensitivity of diffusive cloaks to defects and approximations has not been analyzed. We analytically demonstrate that these approximate cloaks are detectable. Although they work as perfect cloaks in the steady-state, their transient (time-dependent) response is imperfect and a small amount of heat is scattered. This is sufficient to determine the presence of a cloak and any heat source it contains, but the material composition hidden within the cloak is not detectable in practice. To demonstrate the feasibility of this technique, we constructed a cloak with similar approximation and directly detected its presence using these transient temperature deviations outside the cloak. Due to limitations in the range of experimentally accessible volumetric specific heats, our detection scheme should allow us to find any realizable cloak, assuming a sufficiently large temperature difference. PMID:27605153

Reaction-based small-molecule fluorescent probes for dynamic detection of ROS and transient redox changes in living cells and small animals.

PubMed

Lü, Rui

2017-09-01

Dynamic detection of transient redox changes in living cells and animals has broad implications for human health and disease diagnosis, because intracellular redox homeostasis regulated by reactive oxygen species (ROS) plays important role in cell functions, normal physiological functions and some serious human diseases (e.g., cancer, Alzheimer's disease, diabetes, etc.) usually have close relationship with the intracellular redox status. Small-molecule ROS-responsive fluorescent probes can act as powerful tools for dynamic detection of ROS and redox changes in living cells and animals through fluorescence imaging techniques; and great advances have been achieved recently in the design and synthesis of small-molecule ROS-responsive fluorescent probes. This article highlights up-to-date achievements in designing and using the reaction-based small-molecule fluorescent probes (with high sensitivity and selectivity to ROS and redox cycles) in the dynamic detection of ROS and transient redox changes in living cells and animals through fluorescence imaging. Copyright © 2017. Published by Elsevier Ltd.

High-energy Gamma-Ray Activity from V404 Cygni Detected by AGILE during the 2015 June Outburst

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

Piano, G.; Munar-Adrover, P.; Tavani, M.

The AGILE satellite detected transient high-energy γ -ray emission from the X-ray binary V404 Cygni, during the 2015 June outburst observed in radio, optical, X-ray, and soft γ -ray frequencies. The activity was observed by AGILE in the 50–400 MeV energy band, between 2015 June 24 UT 06:00:00 and 2015 June 26 UT 06:00:00 (MJD 57197.25–57199.25), with a detection significance of ∼4.3 σ . The γ -ray detection, consistent with a contemporaneous observation by Fermi -LAT, is correlated with a bright flare observed at radio and hard X-ray frequencies, and with a strong enhancement of the 511 keV line emission,more » possibly indicating plasmoid ejections in a lepton-dominated transient jet. The AGILE observations of this binary system are compatible with a microquasar scenario in which transient jets are responsible for the high-energy γ -ray emission.« less

Intermittent/transient fault phenomena in digital systems

NASA Technical Reports Server (NTRS)

Masson, G. M.

1977-01-01

An overview of the intermittent/transient (IT) fault study is presented. An interval survivability evaluation of digital systems for IT faults is discussed along with a method for detecting and diagnosing IT faults in digital systems.

Laser-induced transient grating setup with continuously tunable period

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

Vega-Flick, A.; Applied Physics Department, CINVESTAV-Unidad Mérida, Carretera Antigua a Progreso Km 6, Cordemex, Mérida, Yucatán 97310 Mexico; Eliason, J. K.

2015-12-15

We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup.

Cardiogenic Pulmonary Edema in a Dog Following Initiation of Therapy for Concurrent Hypoadrenocorticism and Hypothyroidism.

PubMed

Paik, Jooyae; Kang, Ji-Houn; Chang, Dongwoo; Yang, Mhan-Pyo

A 5 yr old intact female cocker spaniel dog weighing 7.8 kg was referred with anorexia, vomiting, and depression. At referral, the dog was diagnosed initially with typical hypoadrenocorticism, and 2 d later, concurrent primary hypothyroidism was detected. Hormonal replacement therapies, including fludrocortisone, prednisolone, and levothyroxine, were initiated, but a few days later the dog became abruptly tachypneic, and thoracic radiographs indicated the development of pulmonary edema. Echocardiography showed that there were abnormalities indicating impaired left ventricular function, although the heart valves were normal. Following treatment with pimobendan and furosemide, the pulmonary edema resolved. The dog had no recurrence of the clinical signs after 10 mo of follow-up, despite being off all cardiac medications; consequently, the cardiac failure was transient or reversible in this dog. The case report describes the stepwise diagnosis and successful treatment of cardiogenic pulmonary edema after initiation of hormonal replacement therapy for concurrent hypoadrenocorticism and hypothyroidism in a dog.

Gamma ray transients

NASA Technical Reports Server (NTRS)

Cline, Thomas L.

1987-01-01

The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

Transient water stress in a vegetation canopy - Simulations and measurements

NASA Technical Reports Server (NTRS)

Carlson, Toby N.; Belles, James E.; Gillies, Robert R.

1991-01-01

Consideration is given to observational and modeling evidence of transient water stress, the effects of the transpiration plateau on the canopy radiometric temperature, and the factors responsible for the onset of the transpiration plateau, such as soil moisture. Attention is also given to the point at which the transient stress can be detected by remote measurement of surface temperature.

A Doppler Transient Model Based on the Laplace Wavelet and Spectrum Correlation Assessment for Locomotive Bearing Fault Diagnosis

PubMed Central

Shen, Changqing; Liu, Fang; Wang, Dong; Zhang, Ao; Kong, Fanrang; Tse, Peter W.

2013-01-01

The condition of locomotive bearings, which are essential components in trains, is crucial to train safety. The Doppler effect significantly distorts acoustic signals during high movement speeds, substantially increasing the difficulty of monitoring locomotive bearings online. In this study, a new Doppler transient model based on the acoustic theory and the Laplace wavelet is presented for the identification of fault-related impact intervals embedded in acoustic signals. An envelope spectrum correlation assessment is conducted between the transient model and the real fault signal in the frequency domain to optimize the model parameters. The proposed method can identify the parameters used for simulated transients (periods in simulated transients) from acoustic signals. Thus, localized bearing faults can be detected successfully based on identified parameters, particularly period intervals. The performance of the proposed method is tested on a simulated signal suffering from the Doppler effect. Besides, the proposed method is used to analyze real acoustic signals of locomotive bearings with inner race and outer race faults, respectively. The results confirm that the periods between the transients, which represent locomotive bearing fault characteristics, can be detected successfully. PMID:24253191

Deep-HiTS: Rotation Invariant Convolutional Neural Network for Transient Detection

NASA Astrophysics Data System (ADS)

Cabrera-Vives, Guillermo; Reyes, Ignacio; Förster, Francisco; Estévez, Pablo A.; Maureira, Juan-Carlos

2017-02-01

We introduce Deep-HiTS, a rotation-invariant convolutional neural network (CNN) model for classifying images of transient candidates into artifacts or real sources for the High cadence Transient Survey (HiTS). CNNs have the advantage of learning the features automatically from the data while achieving high performance. We compare our CNN model against a feature engineering approach using random forests (RFs). We show that our CNN significantly outperforms the RF model, reducing the error by almost half. Furthermore, for a fixed number of approximately 2000 allowed false transient candidates per night, we are able to reduce the misclassified real transients by approximately one-fifth. To the best of our knowledge, this is the first time CNNs have been used to detect astronomical transient events. Our approach will be very useful when processing images from next generation instruments such as the Large Synoptic Survey Telescope. We have made all our code and data available to the community for the sake of allowing further developments and comparisons at https://github.com/guille-c/Deep-HiTS. Deep-HiTS is licensed under the terms of the GNU General Public License v3.0.

A Doppler transient model based on the laplace wavelet and spectrum correlation assessment for locomotive bearing fault diagnosis.

PubMed

Shen, Changqing; Liu, Fang; Wang, Dong; Zhang, Ao; Kong, Fanrang; Tse, Peter W

2013-11-18

The condition of locomotive bearings, which are essential components in trains, is crucial to train safety. The Doppler effect significantly distorts acoustic signals during high movement speeds, substantially increasing the difficulty of monitoring locomotive bearings online. In this study, a new Doppler transient model based on the acoustic theory and the Laplace wavelet is presented for the identification of fault-related impact intervals embedded in acoustic signals. An envelope spectrum correlation assessment is conducted between the transient model and the real fault signal in the frequency domain to optimize the model parameters. The proposed method can identify the parameters used for simulated transients (periods in simulated transients) from acoustic signals. Thus, localized bearing faults can be detected successfully based on identified parameters, particularly period intervals. The performance of the proposed method is tested on a simulated signal suffering from the Doppler effect. Besides, the proposed method is used to analyze real acoustic signals of locomotive bearings with inner race and outer race faults, respectively. The results confirm that the periods between the transients, which represent locomotive bearing fault characteristics, can be detected successfully.

Identification of speech transients using variable frame rate analysis and wavelet packets.

PubMed

Rasetshwane, Daniel M; Boston, J Robert; Li, Ching-Chung

2006-01-01

Speech transients are important cues for identifying and discriminating speech sounds. Yoo et al. and Tantibundhit et al. were successful in identifying speech transients and, emphasizing them, improving the intelligibility of speech in noise. However, their methods are computationally intensive and unsuitable for real-time applications. This paper presents a method to identify and emphasize speech transients that combines subband decomposition by the wavelet packet transform with variable frame rate (VFR) analysis and unvoiced consonant detection. The VFR analysis is applied to each wavelet packet to define a transitivity function that describes the extent to which the wavelet coefficients of that packet are changing. Unvoiced consonant detection is used to identify unvoiced consonant intervals and the transitivity function is amplified during these intervals. The wavelet coefficients are multiplied by the transitivity function for that packet, amplifying the coefficients localized at times when they are changing and attenuating coefficients at times when they are steady. Inverse transform of the modified wavelet packet coefficients produces a signal corresponding to speech transients similar to the transients identified by Yoo et al. and Tantibundhit et al. A preliminary implementation of the algorithm runs more efficiently.

A mathematical model of action potential heterogeneity in adult rat left ventricular myocytes.

PubMed Central

Pandit, S V; Clark, R B; Giles, W R; Demir, S S

2001-01-01

Mathematical models were developed to reconstruct the action potentials (AP) recorded in epicardial and endocardial myocytes isolated from the adult rat left ventricle. The main goal was to obtain additional insight into the ionic mechanisms responsible for the transmural AP heterogeneity. The simulation results support the hypothesis that the smaller density and the slower reactivation kinetics of the Ca(2+)-independent transient outward K(+) current (I(t)) in the endocardial myocytes can account for the longer action potential duration (APD), and more prominent rate dependence in that cell type. The larger density of the Na(+) current (I(Na)) in the endocardial myocytes results in a faster upstroke (dV/dt(max)). This, in addition to the smaller magnitude of I(t), is responsible for the larger peak overshoot of the simulated endocardial AP. The prolonged APD in the endocardial cell also leads to an enhanced amplitude of the sustained K(+) current (I(ss)), and a larger influx of Ca(2+) ions via the L-type Ca(2+) current (I(CaL)). The latter results in an increased sarcoplasmic reticulum (SR) load, which is mainly responsible for the higher peak systolic value of the Ca(2+) transient [Ca(2+)](i), and the resultant increase in the Na(+)-Ca(2+) exchanger (I(NaCa)) activity, associated with the simulated endocardial AP. In combination, these calculations provide novel, quantitative insights into the repolarization process and its naturally occurring transmural variations in the rat left ventricle. PMID:11720973

Fission products behaviour during a power transient: Their inventory in an intragranular bubble

NASA Astrophysics Data System (ADS)

Desgranges, L.; Blay, Th.; Lamontagne, J.; Roure, I.; Bienvenu, Ph.

2017-09-01

The behaviour of fission products is a key issue during Anticipated Operational Occurrences (AOOs) or Condition II transients or accidental sequence for nuclear fuel. Here we characterized how fission products behaved inside chromium doped UO2 pellet during a power ramp. At the pellet centre fission products have left the UO2 lattice and can be found in bubbles. The composition of the bubbles was determined using an original experimental methodology. The existence of separated precipitates made of metallic fission products for the one, and volatile fission products for the other, was evidenced. This result is discussed with regards to the behaviour of fission products during a power ramp.

Machine Learning for Zwicky Transient Facility

NASA Astrophysics Data System (ADS)

Mahabal, Ashish; Zwicky Transient Facility, Catalina Real-Time Transient Survey

2018-01-01

The Zwicky Transient Facility (ZTF) will operate from 2018 to 2020 covering the accessible sky with its large 47 square degree camera. The transient detection rate is expected to be about a million per night. ZTF is thus a perfect LSST prototype. The big difference is that all of the ZTF transients can be followed up by 4- to 8-m class telescopes. Given the large numbers, using human scanners for separating the genuine transients from artifacts is out of question. For that first step as well as for classifying the transients with minimal follow-up requires machine learning. We describe the tools and plans to take on this task using follow-up facilities, and knowledge gained from archival datasets.

Multiple-Beam Detection of Fast Transient Radio Sources

NASA Technical Reports Server (NTRS)

Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.

2011-01-01

A method has been designed for using multiple independent stations to discriminate fast transient radio sources from local anomalies, such as antenna noise or radio frequency interference (RFI). This can improve the sensitivity of incoherent detection for geographically separated stations such as the very long baseline array (VLBA), the future square kilometer array (SKA), or any other coincident observations by multiple separated receivers. The transients are short, broadband pulses of radio energy, often just a few milliseconds long, emitted by a variety of exotic astronomical phenomena. They generally represent rare, high-energy events making them of great scientific value. For RFI-robust adaptive detection of transients, using multiple stations, a family of algorithms has been developed. The technique exploits the fact that the separated stations constitute statistically independent samples of the target. This can be used to adaptively ignore RFI events for superior sensitivity. If the antenna signals are independent and identically distributed (IID), then RFI events are simply outlier data points that can be removed through robust estimation such as a trimmed or Winsorized estimator. The alternative "trimmed" estimator is considered, which excises the strongest n signals from the list of short-beamed intensities. Because local RFI is independent at each antenna, this interference is unlikely to occur at many antennas on the same step. Trimming the strongest signals provides robustness to RFI that can theoretically outperform even the detection performance of the same number of antennas at a single site. This algorithm requires sorting the signals at each time step and dispersion measure, an operation that is computationally tractable for existing array sizes. An alternative uses the various stations to form an ensemble estimate of the conditional density function (CDF) evaluated at each time step. Both methods outperform standard detection strategies on a test sequence of VLBA data, and both are efficient enough for deployment in real-time, online transient detection applications.

Transient Rotor Activity During Prolonged 3-Dimensional Phase Mapping in Human Persistent Atrial Fibrillation.

PubMed

Pathik, Bhupesh; Kalman, Jonathan M; Walters, Tomos; Kuklik, Pawel; Zhao, Jichao; Madry, Andrew; Prabhu, Sandeep; Nalliah, Chrishan; Kistler, Peter; Lee, Geoffrey

2018-01-01

This study sought to validate a 3-dimensional (3D) phase mapping system and determine the distribution of dominant propagation patterns in persistent atrial fibrillation (AF). Currently available systems display phase as simplified 2-dimensional maps. We developed a novel 3D phase mapping system that uses the 3D location of basket catheter electrodes and the patient's 3D left atrial surface geometry to interpolate phase and create a 3D representation of phase progression. Six-min AF recordings from the left atrium were obtained in 14 patients using the Constellation basket catheter and analyzed offline. Exported signals underwent both phase and traditional activation analysis and were then visualized using a novel 3D mapping system. Analysis involved: 1) validation of phase analysis by comparing beat-to-beat AF cycle length calculated using phase inversion with that determined from activation timing in the same 20-s segment; 2) validation of 3D phase by comparing propagation patterns observed using 3D phase with 3D activation in the same 1-min segment; and 3) determining the distribution of dominant propagation patterns in 6-min recordings using 3D phase. There was strong agreement of beat-to-beat AF cycle length between activation analysis and phase inversion (R 2  = 0.91). There was no significant difference between 3D activation and 3D phase in mean percentage of propagation patterns classified as single wavefronts (p = 0.99), focal activations (p = 0.26), disorganized activity (p = 0.76), or multiple wavefronts (p = 0.70). During prolonged 3D phase, single wavefronts were the most common propagation pattern (50.2%). A total of 34 rotors were seen in 9 of 14 patients. All rotors were transient with mean duration of 1.0 ± 0.6 s. Rotors were only observed in areas of high electrode density where the interelectrode distance was significantly shorter than nonrotor sites (7.4 [interquartile range: 6.3 to 14.6] vs. 15.3 mm [interquartile range: 10.1 to 22.2]; p < 0.001). During prolonged 3D phase mapping, transient rotors were observed in 64% of patients and reformed at the same anatomic location in 44% of patients. The electrode density of the basket catheter may limit the detection of rotors. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

All-Sky Monitoring with the Fermi Gamma Ray Burst Monitor

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.

2010-01-01

We are currently monitoring the transient hard X-ray/soft gamma ray sky using the Gamma Ray Burst Monitor (GBM) on-board Fermi. The twelve GBM NaI detectors span 8 keV to 1MeV, while the two GBM BGO detectors span about 150 keV to 40 MeV. With GBM, we detect transient events on multiple timescales. Brief events, such as Gamma Ray Bursts, Solar flares, and magnetar bursts are detected with on-board triggers. On longer timescales, we use the Earth occultation technique to monitor a number of sources, including X-ray binaries, AGN, and solar flaring activity. To date we have detected 7 sources above 100 keV. Transient activity from accretion-powered pulsars is monitored using epoch-folding techniques. With GBM we track the pulsed flux and frequency for a number of pulsars. We will present highlights of GBM observations on various timescales.

Weak Fault Feature Extraction of Rolling Bearings Based on an Improved Kurtogram.

PubMed

Chen, Xianglong; Feng, Fuzhou; Zhang, Bingzhi

2016-09-13

Kurtograms have been verified to be an efficient tool in bearing fault detection and diagnosis because of their superiority in extracting transient features. However, the short-time Fourier Transform is insufficient in time-frequency analysis and kurtosis is deficient in detecting cyclic transients. Those factors weaken the performance of the original kurtogram in extracting weak fault features. Correlated Kurtosis (CK) is then designed, as a more effective solution, in detecting cyclic transients. Redundant Second Generation Wavelet Packet Transform (RSGWPT) is deemed to be effective in capturing more detailed local time-frequency description of the signal, and restricting the frequency aliasing components of the analysis results. The authors in this manuscript, combining the CK with the RSGWPT, propose an improved kurtogram to extract weak fault features from bearing vibration signals. The analysis of simulation signals and real application cases demonstrate that the proposed method is relatively more accurate and effective in extracting weak fault features.

Songbird use of floodplain and upland forests along the Upper Mississippi River corridor during spring migration

USGS Publications Warehouse

Kirsch, Eileen M.; Heglund, Patricia J.; Gray, Brian R.; Mckann, Patrick

2013-01-01

The Upper Mississippi River is thought to provide important stopover habitat for migrating landbirds because of its north-south orientation and floodplain forests. The river flows through the Driftless Area of southwestern Wisconsin and southeastern Minnesota where forests are plentiful, yet forests of the floodplain and Driftless Area uplands differ greatly in landscape setting, tree species composition, and topography. We compared landbird assemblages in these upland and floodplain forests over three springs, 2005–2007, using line-transect surveys at randomly selected areas in and within 16 km of the floodplain. We found more species of both transient and locally breeding migrants per survey in floodplain than in upland forest. Detections of transient neotropical migrants did not differ statistically by habitat. Detections of locally breeding neotropical and temperate-zone migrants and transient temperate-zone migrants were greater in floodplain than in upland forest. Between floodplain and upland forest, assemblages of locally breeding species, including neotropical and temperate-zone migrants (of which some individuals were in transit), differed substantially, but assemblages of transients (including both neotropical and temperate-zone migrants) did not differ as much. Only two species of transient migrants had clear affinities for floodplain forest, and none had an affinity for upland forest, whereas most locally breeding migrants had an affinity for either upland or floodplain forest. Within each spring, however, detections of transient neotropical migrants shifted from being greater in floodplain to greater in upland forests. This intraseasonal shift may be related to the phenology of certain tree species.

Performance Characterization of Swept Ramp Obstacle Fields in Pulse Detonation Applications

DTIC Science & Technology

2010-03-01

field of practical obstacle geometries. 15. NUMBER OF PAGES 97 14. SUBJECT TERMS Pulse Detonation , PDE , Transient Plasma Ignition, TPI, Swept... Detonation Transition NI - National Instruments NPS - Naval Postgraduate School PDC - Pulse Detonation Combustor PDE - Pulse Detonation Engine...with incredible grace. xvi THIS PAGE INTENTIONALLY LEFT BLANK 1 I. INTRODUCTION Pulse detonation engines ( PDE ) continue to be explored due to

Can we observe neutrino flares in coincidence with explosive transients?

NASA Astrophysics Data System (ADS)

Guépin, C.; Kotera, K.

2017-12-01

The new generation of powerful instruments is reaching sensitivities and temporal resolutions that will allow multi-messenger astronomy of explosive transient phenomena, with high-energy neutrinos as a central figure. We derive general criteria for the detectability of neutrinos from powerful transient sources for given instrument sensitivities. In practice, we provide the minimum photon flux necessary for neutrino detection based on two main observables: the bolometric luminosity and the time variability of the emission. This limit can be compared to the observations in specified wavelengths in order to target the most promising sources for follow-ups. Our criteria can also help distinguishing false associations of neutrino events with a flaring source. We find that relativistic transient sources such as high- and low-luminosity gamma-ray bursts (GRBs), blazar flares, tidal disruption events, and magnetar flares could be observed with IceCube, as they have a good chance to occur within a detectable distance. Of the nonrelativistic transient sources, only luminous supernovae appear as promising candidates. We caution that our criterion should not be directly applied to low-luminosity GRBs and type Ibc supernovae, as these objects could have hosted a choked GRB, leading to neutrino emission without a relevant counterpart radiation. We treat the concrete example of PKS 1424-418 major outburst and the possible association with an IceCube event IC 35.

Detecting aseismic strain transients from seismicity data

USGS Publications Warehouse

Llenos, A.L.; McGuire, J.J.

2011-01-01

Aseismic deformation transients such as fluid flow, magma migration, and slow slip can trigger changes in seismicity rate. We present a method that can detect these seismicity rate variations and utilize these anomalies to constrain the underlying variations in stressing rate. Because ordinary aftershock sequences often obscure changes in the background seismicity caused by aseismic processes, we combine the stochastic Epidemic Type Aftershock Sequence model that describes aftershock sequences well and the physically based rate- and state-dependent friction seismicity model into a single seismicity rate model that models both aftershock activity and changes in background seismicity rate. We implement this model into a data assimilation algorithm that inverts seismicity catalogs to estimate space-time variations in stressing rate. We evaluate the method using a synthetic catalog, and then apply it to a catalog of M???1.5 events that occurred in the Salton Trough from 1990 to 2009. We validate our stressing rate estimates by comparing them to estimates from a geodetically derived slip model for a large creep event on the Obsidian Buttes fault. The results demonstrate that our approach can identify large aseismic deformation transients in a multidecade long earthquake catalog and roughly constrain the absolute magnitude of the stressing rate transients. Our method can therefore provide a way to detect aseismic transients in regions where geodetic resolution in space or time is poor. Copyright 2011 by the American Geophysical Union.

Novel Analysis Software for Detecting and Classifying Ca2+ Transient Abnormalities in Stem Cell-Derived Cardiomyocytes

PubMed Central

Penttinen, Kirsi; Siirtola, Harri; Àvalos-Salguero, Jorge; Vainio, Tiina; Juhola, Martti; Aalto-Setälä, Katriina

2015-01-01

Comprehensive functioning of Ca2+ cycling is crucial for excitation–contraction coupling of cardiomyocytes (CMs). Abnormal Ca2+ cycling is linked to arrhythmogenesis, which is associated with cardiac disorders and heart failure. Accordingly, we have generated spontaneously beating CMs from induced pluripotent stem cells (iPSC) derived from patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), which is an inherited and severe cardiac disease. Ca2+ cycling studies have revealed substantial abnormalities in these CMs. Ca2+ transient analysis performed manually lacks accepted analysis criteria, and has both low throughput and high variability. To overcome these issues, we have developed a software tool, AnomalyExplorer based on interactive visualization, to assist in the classification of Ca2+ transient patterns detected in CMs. Here, we demonstrate the usability and capability of the software, and we also compare the analysis efficiency to manual analysis. We show that AnomalyExplorer is suitable for detecting normal and abnormal Ca2+ transients; furthermore, this method provides more defined and consistent information regarding the Ca2+ abnormality patterns and cell line specific differences when compared to manual analysis. This tool will facilitate and speed up the analysis of CM Ca2+ transients, making it both more accurate and user-independent. AnomalyExplorer can be exploited in Ca2+ cycling analysis to study basic disease pathology and the effects of different drugs. PMID:26308621

Novel Analysis Software for Detecting and Classifying Ca2+ Transient Abnormalities in Stem Cell-Derived Cardiomyocytes.

PubMed

Penttinen, Kirsi; Siirtola, Harri; Àvalos-Salguero, Jorge; Vainio, Tiina; Juhola, Martti; Aalto-Setälä, Katriina

2015-01-01

Comprehensive functioning of Ca2+ cycling is crucial for excitation-contraction coupling of cardiomyocytes (CMs). Abnormal Ca2+ cycling is linked to arrhythmogenesis, which is associated with cardiac disorders and heart failure. Accordingly, we have generated spontaneously beating CMs from induced pluripotent stem cells (iPSC) derived from patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), which is an inherited and severe cardiac disease. Ca2+ cycling studies have revealed substantial abnormalities in these CMs. Ca2+ transient analysis performed manually lacks accepted analysis criteria, and has both low throughput and high variability. To overcome these issues, we have developed a software tool, AnomalyExplorer based on interactive visualization, to assist in the classification of Ca2+ transient patterns detected in CMs. Here, we demonstrate the usability and capability of the software, and we also compare the analysis efficiency to manual analysis. We show that AnomalyExplorer is suitable for detecting normal and abnormal Ca2+ transients; furthermore, this method provides more defined and consistent information regarding the Ca2+ abnormality patterns and cell line specific differences when compared to manual analysis. This tool will facilitate and speed up the analysis of CM Ca2+ transients, making it both more accurate and user-independent. AnomalyExplorer can be exploited in Ca2+ cycling analysis to study basic disease pathology and the effects of different drugs.

Interpreting signals from astrophysical transient experiments

PubMed Central

O’Brien, Paul T.; Smartt, Stephen J.

2013-01-01

Time-domain astronomy has come of age with astronomers now able to monitor the sky at high cadence, both across the electromagnetic spectrum and using neutrinos and gravitational waves. The advent of new observing facilities permits new science, but the ever-increasing throughput of facilities demands efficient communication of coincident detections and better subsequent coordination among the scientific community so as to turn detections into scientific discoveries. To discuss the revolution occurring in our ability to monitor the Universe and the challenges it brings, on 25–26 April 2012, a group of scientists from observational and theoretical teams studying transients met with representatives of the major international transient observing facilities at the Kavli Royal Society International Centre, UK. This immediately followed the Royal Society Discussion Meeting ‘New windows on transients across the Universe’ held in London. Here, we present a summary of the Kavli meeting at which the participants discussed the science goals common to the transient astronomy community and analysed how to better meet the challenges ahead as ever more powerful observational facilities come on stream. PMID:23630383

Preliminary analysis of data from SRI international transient pulse monitor on board P78-2 SCATHA satellite

NASA Technical Reports Server (NTRS)

Damron, S. A.; Adamo, R. C.; Nanevicz, J. E.

1980-01-01

The satellite charging at high altitudes (SCATHA) program addresses the occurrence of electrostatic discharges causing undesirable effects like deleterious transients in electronic circuits on satellites. The high altitude plasma environment and the effects of the interaction of this environment with the orbiting satellite are studied. The SRI transient pulse monitor (TPM) detects the transient electromagnetic signals induced in selected circuits. As a transient detector the TPM records transient signals, indicates the number of transients observed, and gives peak amplitude of the largest transient during each second's interval. Most of the early data from the TPM contain pulses associated with internal electrical activity and electrostatic charging on the surface of the P78-2 is evidenced. It is found that periods of external discharging do not necessarily coincide with periods in which high potentials are measured on the satellite's surface.

Transient fault behavior in a microprocessor: A case study

NASA Technical Reports Server (NTRS)

Duba, Patrick

1989-01-01

An experimental analysis is described which studies the susceptibility of a microprocessor based jet engine controller to upsets caused by current and voltage transients. A design automation environment which allows the run time injection of transients and the tracing from their impact device to the pin level is described. The resulting error data are categorized by the charge levels of the injected transients by location and by their potential to cause logic upsets, latched errors, and pin errors. The results show a 3 picoCouloumb threshold, below which the transients have little impact. An Arithmetic and Logic Unit transient is most likely to result in logic upsets and pin errors (i.e., impact the external environment). The transients in the countdown unit are potentially serious since they can result in latched errors, thus causing latent faults. Suggestions to protect the processor against these errors, by incorporating internal error detection and transient suppression techniques, are also made.

Adrenal venous sampling in primary aldosteronism: multinomial regression modeling to detect aldosterone secretion lateralization when right adrenal sampling is missing.

PubMed

Durivage, Camille; Blanchette, Rémi; Soulez, Gilles; Chagnon, Miguel; Gilbert, Patrick; Giroux, Marie-France; Bourdeau, Isabelle; Oliva, Vincent L; Lacroix, André; Therasse, Eric

2017-02-01

Difficulty to recognize or canulate the right adrenal vein is the most frequent cause of adrenal venous sampling (AVS) failure. We aimed to assess multinomial regression modeling (MRM) of peripheral and left adrenal vein samplings to detect lateralization of aldosterone secretion when the right AVS is missing. Simultaneous bilateral AVS samplings were performed before (basal) and after intravenous cosyntropin injection in 188 consecutive patients between December 1989 and September 2015. Different reference standards for lateralization of aldosterone secretion were defined for basal and for postcosyntropin AVS and according to lateralization index cutoffs at least 2 and at least 4. MRMs were built to detect lateralization of aldosterone secretion according to these reference standards using only peripheral and left adrenal veins samplings (without the right AVS). Detection accuracy was assessed by the area under the receiver operating characteristic (AUROC) curves and detection sensitivities were reported for specificity at least 95%. For basal AVS with lateralization index at least 2, AUROC were respectively 0.931 [95% confidence interval (CI) 0.894-0.968] and 0.922 (95% CI 0.882-0.962) for right and left lateralization of aldosterone secretion detection and MRM could detect respectively 65.5 and 62.7% of the right and left lateralization of aldosterone secretion. For AVS after cosyntropin with lateralization index at least 4, AUROC were respectively 0.964 (95% CI: 0.940-0.987) and 0.955 (95% CI: 0.927-0.983) for right and left lateralization of aldosterone secretion, and MRM could detect respectively 77.2 and 72.9% of the right and left lateralization of aldosterone secretion. MRM can detect lateralization of aldosterone secretion without the right AVS in most patients and could eliminate the need for repeat AVS when right adrenal vein canulation is nonselective or impossible.

[Takotsubo cardiomyopathy in the context of Staphylococcus aureus sepsis].

PubMed

Núñez, D; Bermejo, R; Rodríguez-Velasco, A

2014-03-01

Takotsubo cardiomyopathy consists of a transient dysfunction of the left ventricle. It is characterised by an impaired left ventricular segmentary contractility, without significant coronary lesions in the coronary angiography. It usually occurs after an episode of physical or emotional stress. We present the case of a 70 year-old woman, who, in the postoperative period of an ankle osteosynthesis, developed a Takotsubo cardiomyopathy in the context of a sepsis caused by Staphylococcus aureus. She presented with acute lung oedema and a clinical picture of low cardiac output. The echocardiogram showed left ventricular medioapical akinesia. Coronary angiography was normal. She was treated with supportive measures with good progress. At 33 days from onset she was able to be discharged from hospital to home with normal systolic function on echocardiography. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Exploring results of the possibility on detecting cosmic ray particles by acoustic way

NASA Technical Reports Server (NTRS)

Jiang, Y.; Yuan, Y.; Li, Y.; Chen, D.; Zheng, R.; Song, J.

1985-01-01

It has been demonstrated experimentally and theoretically that high energy particles produce detectable sounds in water. However, no one has been able to detect an acoustic signal generated by a high energy cosmic ray particle in water. Results show that transient ultrasonic signals in a large lake or reservoir are fairly complex and that the transient signals under water may arise mainly from sound radiation from microbubbles. This field is not explored in detail. Perhaps, the sounds created by cosmic ray particles hide in these ultrasonic signals. In order to develop the technique of acoustic detection, it is most important to make a thorough investigation of these ultrasonic signals in water.

FLaapLUC: A pipeline for the generation of prompt alerts on transient Fermi-LAT γ-ray sources

NASA Astrophysics Data System (ADS)

Lenain, J.-P.

2018-01-01

The large majority of high energy sources detected with Fermi-LAT are blazars, which are known to be very variable sources. High cadence long-term monitoring simultaneously at different wavelengths being prohibitive, the study of their transient activities can help shedding light on our understanding of these objects. The early detection of such potentially fast transient events is the key for triggering follow-up observations at other wavelengths. A Python tool, FLaapLUC, built on top of the Science Tools provided by the Fermi Science Support Center and the Fermi-LAT collaboration, has been developed using a simple aperture photometry approach. This tool can effectively detect relative flux variations in a set of predefined sources and alert potential users. Such alerts can then be used to trigger target of opportunity observations with other facilities. It is shown that FLaapLUC is an efficient tool to reveal transient events in Fermi-LAT data, providing quick results which can be used to promptly organise follow-up observations. Results from this simple aperture photometry method are also compared to full likelihood analyses. The FLaapLUC package is made available on GitHub and is open to contributions by the community.

Left-sided strokes are more often recognized than right-sided strokes: the Rotterdam study.

PubMed

Portegies, Marileen L P; Selwaness, Mariana; Hofman, Albert; Koudstaal, Peter J; Vernooij, Meike W; Ikram, M Arfan

2015-01-01

Left-sided strokes are reported to be more common than right-sided strokes, but it is unknown whether they occur more often or are simply recognized more easily by clinicians. In a large unselected community-dwelling population, we examined the frequency of clinical left- and right-sided strokes and transient ischemic attacks (TIAs) and compared it with the frequency of left- and right-sided infarcts on MRI. This study was conducted within the population-based Rotterdam Study. Between 1990 and 2012, 13 894 participants were followed up for first-ever stroke and TIA. MRI scans were performed within a random subgroup of 5081 persons and were rated for the presence of supratentorial cortical and lacunar infarcts. We compared frequencies of left- and right-sided strokes, TIAs, or MRI infarcts using binomial and Fisher exact tests. After a mean follow-up of 9.6 (±6.0) years, 1252 patients had a stroke, of which 704 were ischemic, and 799 participants had a TIA. Within the subgroup with MRI, we identified 673 infarcts. Ischemic strokes were more frequently left-sided (57.7%; 95% confidence interval, 53.7-61.6) than right-sided, similar to TIAs (57.8% left-sided; 53.4-62.3). In contrast, we found no left-right difference in distribution of infarcts on MRI (51.9% left-sided; 48.1-55.6). Clinical ischemic strokes and TIAs are more frequently left-sided than right-sided, whereas this difference is not present for infarcts on MRI. This suggests that left-sided strokes and TIAs are more easily recognized. Consequently, there should be more attention for symptoms of right-sided strokes and TIAs. © 2014 American Heart Association, Inc.

A pilot survey for transients and variables with the Australian Square Kilometre Array Pathfinder

NASA Astrophysics Data System (ADS)

Bhandari, S.; Bannister, K. W.; Murphy, T.; Bell, M.; Raja, W.; Marvil, J.; Hancock, P. J.; Whiting, M.; Flynn, C. M.; Collier, J. D.; Kaplan, D. L.; Allison, J. R.; Anderson, C.; Heywood, I.; Hotan, A.; Hunstead, R.; Lee-Waddell, K.; Madrid, J. P.; McConnell, D.; Popping, A.; Rhee, J.; Sadler, E.; Voronkov, M. A.

2018-05-01

We present a pilot search for variable and transient sources at 1.4 GHz with the Australian Square Kilometre Array Pathfinder (ASKAP). The search was performed in a 30 deg2 area centred on the NGC 7232 galaxy group over 8 epochs and observed with a near-daily cadence. The search yielded nine potential variable sources, rejecting the null hypothesis that the flux densities of these sources do not change with 99.9% confidence. These nine sources displayed flux density variations with modulation indices m ≥ 0.1 above our flux density limit of ˜1.5 mJy. They are identified to be compact AGN/quasars or galaxies hosting an AGN, whose variability is consistent with refractive interstellar scintillation. We also detect a highly variable source with modulation index m > 0.5 over a time interval of a decade between the Sydney University Molonglo Sky Survey (SUMSS) and our latest ASKAP observations. We find the source to be consistent with the properties of long-term variability of a quasar. No transients were detected on timescales of days and we place an upper limit ρt < 0.01 deg-2 with 95% confidence for non-detections on near-daily timescales. The future VAST-Wide survey with 36-ASKAP dishes will probe the transient phase space with similar cadence to our pilot survey, but better sensitivity, and will detect and monitor rarer brighter events.

Transient survey rates for orphan afterglows from compact merger jets

NASA Astrophysics Data System (ADS)

Lamb, Gavin P.; Tanaka, Masaomi; Kobayashi, Shiho

2018-06-01

Orphan afterglows from short γ-ray bursts (GRBs) are potential candidates for electromagnetic (EM) counterpart searches to gravitational wave (GW) detected neutron star or neutron star black hole mergers. Various jet dynamical and structure models have been proposed that can be tested by the detection of a large sample of GW-EM counterparts. We make predictions for the expected rate of optical transients from these jet models for future survey telescopes, without a GW or GRB trigger. A sample of merger jets is generated in the redshift limits 0 ≤ z ≤ 3.0, and the expected peak r-band flux and time-scale above the Large Synoptic Survey Telescope (LSST) or Zwicky Transient Factory (ZTF) detection threshold, mr = 24.5 and 20.4, respectively, is calculated. General all-sky rates are shown for mr ≤ 26.0 and mr ≤ 21.0. The detected orphan and GRB afterglow rate depends on jet model, typically 16≲ R≲ 76 yr-1 for the LSST, and 2≲ R ≲ 8 yr-1 for ZTF. An excess in the rate of orphan afterglows for a survey to a depth of mr ≤ 26 would indicate that merger jets have a dominant low-Lorentz factor population, or the jets exhibit intrinsic jet structure. Careful filtering of transients is required to successfully identify orphan afterglows from either short- or long-GRB progenitors.

76 FR 27232 - Airworthiness Directives; Airbus Model A310 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... rototest inspection to detect cracks in the area of frame 47 and frame 54, install new doublers, and repair if necessary. Repetitive visual inspections to detect cracks on frame 46 between the left- and right... visual inspections to detect cracks at the T- section connecting frame 50A to the beam between the left...

Left ventricular mass, blood pressure, and lowered cognitive performance in the Framingham offspring.

PubMed

Elias, Merrill F; Sullivan, Lisa M; Elias, Penelope K; D'Agostino, Ralph B; Wolf, Philip A; Seshadri, Sudha; Au, Rhoda; Benjamin, Emelia J; Vasan, Ramachandran S

2007-03-01

The purpose of this study was to determine whether echocardiographic left ventricular mass is related to cognitive performance beyond casual blood pressure adjusting for the influence of other vascular risk factors. We used multivariable regression analyses to relate left ventricular mass assessed at a routine examination (1995-1998) to measures of cognitive ability obtained routinely (1998-2001) in 1673 Framingham Offspring Study participants (56% women; mean age: 57 years) free from stroke, transient ischemic attack, and dementia. We adjusted for the following covariates hierarchically: (1) age, education, sex, body weight, height, interval between left ventricular mass measurement and neuropsychological testing (basic model); (2) basic model+blood pressure+treatment for hypertension; and (3) basic model+blood pressure+treatment for hypertension+vascular risk factors and prevalent cardiovascular disease. For the basic model, left ventricular mass was inversely associated with abstract reasoning (similarities), visual-spatial memory and organization, and verbal memory. For the basic model+blood pressure+treatment for hypertension, left ventricular mass was inversely associated with similarities and visual-spatial memory and organization. For the basic+blood pressure+treatment for hypertension+risk factors+cardiovascular disease model, no significant associations were observed. Echocardiographic left ventricular mass is associated with cognitive performance beyond casual and time-averaged systolic blood pressure, but this association is attenuated and rendered nonsignificant with additional adjustment for cardiovascular risk factors and cardiovascular disease, thus suggesting that these variables play an important role in mediating the association between left ventricular mass and cognition.

Fully automatic detection of salient features in 3-d transesophageal images.

PubMed

Curiale, Ariel H; Haak, Alexander; Vegas-Sánchez-Ferrero, Gonzalo; Ren, Ben; Aja-Fernández, Santiago; Bosch, Johan G

2014-12-01

Most automated segmentation approaches to the mitral valve and left ventricle in 3-D echocardiography require a manual initialization. In this article, we propose a fully automatic scheme to initialize a multicavity segmentation approach in 3-D transesophageal echocardiography by detecting the left ventricle long axis, the mitral valve and the aortic valve location. Our approach uses a probabilistic and structural tissue classification to find structures such as the mitral and aortic valves; the Hough transform for circles to find the center of the left ventricle; and multidimensional dynamic programming to find the best position for the left ventricle long axis. For accuracy and agreement assessment, the proposed method was evaluated in 19 patients with respect to manual landmarks and as initialization of a multicavity segmentation approach for the left ventricle, the right ventricle, the left atrium, the right atrium and the aorta. The segmentation results revealed no statistically significant differences between manual and automated initialization in a paired t-test (p > 0.05). Additionally, small biases between manual and automated initialization were detected in the Bland-Altman analysis (bias, variance) for the left ventricle (-0.04, 0.10); right ventricle (-0.07, 0.18); left atrium (-0.01, 0.03); right atrium (-0.04, 0.13); and aorta (-0.05, 0.14). These results indicate that the proposed approach provides robust and accurate detection to initialize a multicavity segmentation approach without any user interaction. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Buccofacial apraxia and left cerebral haemorrhage.

PubMed

Maeshima, S; Truman, G; Smith, D S; Dohi, N; Itakura, T; Komai, N

1997-11-01

We examined 33 patients with left intracerebral haemorrhage to investigate the relations to buccofacial apraxia (BFA). BFA was present in 18 cases at 1 month and disappeared in 3 cases and persisted in 15 cases at 6 month from the onset. The existence of BFA seems to be partially dependent the haematoma volume which may cause the organic damage in lenticulate nucleus, insula, posterior limb or internal capsule and anterior portion of paraventricle white matter. All patients with BFA had aphasia (Broca 6, Wernicke 1, Total 10, Amnestic 1). Aphasia of the patients with transient BFA improved as well as the patients without BFA after BFA disappeared. We suspected that improvement or aphasia might be affected by BFA.

Role of nuclear cardiology in evaluating the total ischemic burden in coronary artery disease

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

Beller, G.A.

1987-03-09

Goals of exercise radionuclide imaging are to: enhance sensitivity, specificity and predictive value of coronary artery disease (CAD) detection; noninvasively assess extent and severity of functionally significant CAD; determine prognosis so that specific therapeutic strategies can be more rationally implemented; detect silent ischemia in asymptomatic subjects or in patients with known CAD with a higher degree of specificity than can be accomplished by electrocardiogram stress testing alone; evaluate the response to therapeutic interventions aimed at enhancing coronary blood flow. Two major radionuclide techniques are currently used in evaluating the total ischemic burden in patients with CAD. These are myocardial perfusionmore » imaging with either thallium-201 or rubidium-82, and radionuclide angiography performed after administration of technetium-99m. Areas of diminished thallium-201 activity on early postexercise images are abnormal and represent either areas of stress-induced ischemia or myocardial scar. To differentiate between the two, delayed images are obtained to determine if the initial postexercise defect either persists or demonstrates redistribution. Defects demonstrating redistribution represent transient ischemia, whereas areas of previous infarction or scar usually appear as persistent defects. Patients with left main or 3-vessel CAD usually show multiple thallium-201 redistribution defects in more than 1 vascular supply region, a phenomenon often associated with abnormal lung thallium-201 uptake.« less

Functional connectivity in the prefrontal cortex measured by near-infrared spectroscopy during ultrarapid object recognition

NASA Astrophysics Data System (ADS)

Medvedev, Andrei V.; Kainerstorfer, Jana M.; Borisov, Sergey V.; Vanmeter, John

2011-01-01

Near-infrared spectroscopy (NIRS) is a developing technology for low-cost noninvasive functional brain imaging. With multichannel optical instruments, it becomes possible to measure not only local changes in hemoglobin concentrations but also temporal correlations of those changes in different brain regions which gives an optical analog of functional connectivity traditionally measured by fMRI. We recorded hemodynamic activity during the Go-NoGo task from 11 right-handed subjects with probes placed bilaterally over prefrontal areas. Subjects were detecting animals as targets in natural scenes pressing a mouse button. Data were low-pass filtered <1 Hz and cardiac/respiration/superficial layers artifacts were removed using Independent Component Analysis. Fisher's transformed correlations of poststimulus responses (30 s) were averaged over groups of channels unilaterally in each hemisphere (intrahemispheric connectivity) and the corresponding channels between hemispheres (interhemispheric connectivity). The hemodynamic response showed task-related activation (an increase/decrease in oxygenated/deoxygenated hemoglobin, respectively) greater in the right versus left hemisphere. Intra- and interhemispheric functional connectivity was also significantly stronger during the task compared to baseline. Functional connectivity between the inferior and the middle frontal regions was significantly stronger in the right hemisphere. Our results demonstrate that optical methods can be used to detect transient changes in functional connectivity during rapid cognitive processes.

Metaiodobenzylguanidine (/sup 131/I) scintigraphy detects impaired myocardial sympathetic neuronal transport function of canine mechanical-overload heart failure

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

Rabinovitch, M.A.; Rose, C.P.; Rouleau, J.L.

1987-12-01

In heart failure secondary to chronic mechanical overload, cardiac sympathetic neurons demonstrate depressed catecholamine synthetic and transport function. To assess the potential of sympathetic neuronal imaging for detection of depressed transport function, serial scintigrams were acquired after the intravenous administration of metaiodobenzylguanidine (/sup 131/I) to 13 normal dogs, 3 autotransplanted (denervated) dogs, 5 dogs with left ventricular failure, and 5 dogs with compensated left ventricular hypertrophy due to a surgical arteriovenous shunt. Nine dogs were killed at 14 hours postinjection for determination of metaiodobenzylguanidine (/sup 131/I) and endogenous norepinephrine content in left atrium, left ventricle, liver, and spleen. By 4more » hours postinjection, autotransplanted dogs had a 39% reduction in mean left ventricular tracer accumulation, reflecting an absent intraneuronal tracer pool. Failure dogs demonstrated an accelerated early mean left ventricular tracer efflux rate (26.0%/hour versus 13.7%/hour in normals), reflecting a disproportionately increased extraneuronal tracer pool. They also showed reduced late left ventricular and left atrial concentrations of tracer, consistent with a reduced intraneuronal tracer pool. By contrast, compensated hypertrophy dogs demonstrated a normal early mean left ventricular tracer efflux rate (16.4%/hour) and essentially normal late left ventricular and left atrial concentrations of tracer. Metaiodobenzylguanidine (/sup 131/I) scintigraphic findings reflect the integrity of the cardiac sympathetic neuronal transport system in canine mechanical-overload heart failure. Metaiodobenzylguanidine (/sup 123/I) scintigraphy should be explored as a means of early detection of mechanical-overload heart failure in patients.« less

Detection of Northern Hemisphere transient eddies at Gale Crater Mars

NASA Astrophysics Data System (ADS)

Haberle, Robert M.; Juárez, Manuel de la Torre; Kahre, Melinda A.; Kass, David M.; Barnes, Jeffrey R.; Hollingsworth, Jeffery L.; Harri, Ari-Matti; Kahanpää, Henrik

2018-06-01

The Rover Environmental Monitoring Station (REMS) on the Curiosity Rover is operating in the Southern Hemisphere of Mars and is detecting synoptic period oscillations in the pressure data that we attribute to Northern Hemisphere transient eddies. We base this interpretation on the similarity in the periods of the eddies and their seasonal variations with those observed in northern midlatitudes by Viking Lander 2 (VL-2) 18 Mars years earlier. Further support for this interpretation comes from global circulation modeling which shows similar behavior in the transient eddies at the grid points closest to Curiosity and VL-2. These observations provide the first in situ evidence that the frontal systems often associated with "Flushing Dust Storms" do cross the equator and extend into the Southern Hemisphere.

The distribution of calcium in toad cardiac pacemaker cells during spontaneous firing.

PubMed

Ju, Y K; Allen, D G

2000-12-01

Isolated, spontaneously active pacemaker cells from the sinus venosus region of the toad heart were loaded with the calcium indicator fluo-3. The cells were examined with a confocal microscope to investigate the distribution of calcium during spontaneous activity. Three classes of calcium-related signals were present. First, intense, localised, time-invariant signals were detected from structures distributed across the cell interior. Based on the insensitivity to saponin and the distribution in the cell, these signals appear to arise from fluo-3 located in the sarcoplasmic reticulum and the nuclear envelope. Second, spatially uniform signals from the cytoplasm were present at rest and showed spontaneous increases in [Ca2+]i which propagated along the cell. These Ca2+ transients were uniform in intensity across the diameter of the cell and we could detect no significant delay in the middle of the cell compared to the edges. However, within the nucleus the Ca2+ transient showed a clear delay compared to the cytoplasm. Third, localised, transient increases in [Ca2+]i (Ca2+ sparks) which did not propagate were also detectable. These could be detected both near the surface membrane and in the interior of the cell and reduced in magnitude and increased in duration in the presence of ryanodine. The frequency of firing of Ca2+ sparks significantly increased in the 200-ms period preceding a spontaneous Ca2+ transient. These results suggest that pacemaker cells contain sarcoplasmic reticulum which is distributed across the cell. The Ca2+ transient is uniform across the cell indicating that near-synchronous release of Ca2+ from the sarcoplasmic reticulum is achieved. Ca2+ sparks occur in pacemaker cells though their role in pacemaker function remains to be elucidated.

Transient sequences in a hypernetwork generated by an adaptive network of spiking neurons.

PubMed

Maslennikov, Oleg V; Shchapin, Dmitry S; Nekorkin, Vladimir I

2017-06-28

We propose a model of an adaptive network of spiking neurons that gives rise to a hypernetwork of its dynamic states at the upper level of description. Left to itself, the network exhibits a sequence of transient clustering which relates to a traffic in the hypernetwork in the form of a random walk. Receiving inputs the system is able to generate reproducible sequences corresponding to stimulus-specific paths in the hypernetwork. We illustrate these basic notions by a simple network of discrete-time spiking neurons together with its FPGA realization and analyse their properties.This article is part of the themed issue 'Mathematical methods in medicine: neuroscience, cardiology and pathology'. © 2017 The Author(s).

Application of the modified transient plane source technique for early detection of liquid explosives

NASA Astrophysics Data System (ADS)

Bateman, Robert; Harris, Adam; Lee, Linda; Howle, Christopher R.; Ackermann, Sarah L. G.

2016-05-01

The paper will review the feasibility of adapting the Modified Transient Plane Source (MTPS) method as a screening tool for early-detection of explosives and hazardous materials. Materials can be distinguished from others based on their inherent thermal properties (e.g. thermal effusivity) in testing through different types of barrier materials. A complimentary advantage to this technique relative to other traditional detection technologies is that it can penetrate reflective barrier materials, such as aluminum, easily. A strong proof-of-principle is presented on application of the MTPS transient thermal property measuring in the early-screening of liquid explosives. The work demonstrates a significant sensitivity to distinguishing a wide range of fluids based on their thermal properties through a barrier material. The work covers various complicating factors to the longer-term adoption of such a method including the impact of carbonization and viscosity. While some technical challenges remain, the technique offers significant advantages in complimenting existing detection methods in being able to penetrate reflective metal containers (e.g. aluminum soft drinkscans) with ease.

A novel method for transient detection in high-cadence optical surveys. Its application for a systematic search for novae in M 31

NASA Astrophysics Data System (ADS)

Soraisam, Monika D.; Gilfanov, Marat; Kupfer, Thomas; Masci, Frank; Shafter, Allen W.; Prince, Thomas A.; Kulkarni, Shrinivas R.; Ofek, Eran O.; Bellm, Eric

2017-03-01

Context. In the present era of large-scale surveys in the time domain, the processing of data, from procurement up to the detection of sources, is generally automated. One of the main challenges in the astrophysical analysis of their output is contamination by artifacts, especially in the regions of high surface brightness of unresolved emission. Aims: We present a novel method for identifying candidates for variable and transient sources from the outputs of optical time-domain survey data pipelines. We use the method to conduct a systematic search for novae in the intermediate Palomar Transient Factory (iPTF) observations of the bulge part of M 31 during the second half of 2013. Methods: We demonstrate that a significant fraction of artifacts produced by the iPTF pipeline form a locally uniform background of false detections approximately obeying Poissonian statistics, whereas genuine variable and transient sources, as well as artifacts associated with bright stars, result in clusters of detections whose spread is determined by the source localization accuracy. This makes the problem analogous to source detection on images produced by grazing incidence X-ray telescopes, enabling one to utilize the arsenal of powerful tools developed in X-ray astronomy. In particular, we use a wavelet-based source detection algorithm from the Chandra data analysis package CIAO. Results: Starting from 2.5 × 105 raw detections made by the iPTF data pipeline, we obtain approximately 4000 unique source candidates. Cross-matching these candidates with the source-catalog of a deep reference image of the same field, we find counterparts for 90% of the candidates. These sources are either artifacts due to imperfect PSF matching or genuine variable sources. The remaining approximately 400 detections are transient sources. We identify novae among these candidates by applying selection cuts to their lightcurves based on the expected properties of novae. Thus, we recovered all 12 known novae (not counting one that erupted toward the end of the survey) registered during the time span of the survey and discovered three nova candidates. Our method is generic and can be applied to mining any target out of the artifacts in optical time-domain data. As it is fully automated, its incompleteness can be accurately computed and corrected for.

Neuroanatomical correlates of biological motion detection.

PubMed

Gilaie-Dotan, Sharon; Kanai, Ryota; Bahrami, Bahador; Rees, Geraint; Saygin, Ayse P

2013-02-01

Biological motion detection is both commonplace and important, but there is great inter-individual variability in this ability, the neural basis of which is currently unknown. Here we examined whether the behavioral variability in biological motion detection is reflected in brain anatomy. Perceptual thresholds for detection of biological motion and control conditions (non-biological object motion detection and motion coherence) were determined in a group of healthy human adults (n=31) together with structural magnetic resonance images of the brain. Voxel based morphometry analyzes revealed that gray matter volumes of left posterior superior temporal sulcus (pSTS) and left ventral premotor cortex (vPMC) significantly predicted individual differences in biological motion detection, but showed no significant relationship with performance on the control tasks. Our study reveals a neural basis associated with the inter-individual variability in biological motion detection, reliably linking the neuroanatomical structure of left pSTS and vPMC with biological motion detection performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Left atrial appendage resection can be performed minimally invasively with good clinical and echocardiographic outcomes without any severe risk.

PubMed

Inoue, Takafumi; Suematsu, Yoshihiro

2018-01-22

The adverse effects of left atrial appendage (LAA) closure have not yet been evaluated. This study aimed to prove the safety and low invasiveness of LAA resection through our thoracoscopic stand-alone left atrial appendectomy experience. Eighty-seven patients [mean age 68 ± 9 years, 68 men (78%), mean congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischaemic attack to thromboembolism, vascular disease, age 65-74 years and sex category (CHA2DS2-VASc) score 2.9 ± 1.6 points] who had undergone thoracoscopic left atrial appendectomy were selected. The operative and clinical data (left atrial diameter, left ventricular diameter of systole/diastole, ejection fraction, brain natriuretic peptide and human atrial natriuretic peptide) were evaluated. All procedures were performed without cardiopulmonary bypass or cardiac arrest. The LAA was resected with an endoscopic linear cutter device. Except for 1 case with severe pleural adhesion, all operations were performed thoracoscopically. The preoperative and postoperative data are as follows: left atrial diameter 43 ± 5 mm and 43 ± 5 mm (P = 0.8); left ventricular diameter of systole/diastole 50 ± 5/35 ± 6 mm and 48 ± 5/34 ± 6 mm (P < 0.01); ejection fraction 57 ± 10% and 56 ± 10% (P = 0.11); brain natriuretic peptide 97 ± 77 pg/ml and 72 ± 65 pg/ml (P < 0.01) and human atrial natriuretic peptide 73 ± 64 pg/ml and 96 ± 67 pg/ml (P = 0.03), respectively. The mean volume of bleeding in the operation was very small (<10 ml). The mean length of postoperative in-hospital stay was 3.8 ± 1.8 days. All the patients were discharged while maintaining their preoperative activities of daily living without major complications. No thrombus or residual stumps were detected during the 3-month postoperative computed tomography follow-up. The perioperative heart function did not change significantly in this study. Bleeding with resection was minimal, and no rebleeding events occurred. LAA resection did not affect negatively on the cardiac function and did not increase the risk of bleeding risk. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

The GMRT High Resolution Southern Sky Survey for Pulsars and Transients. I. Survey Description and Initial Discoveries

NASA Astrophysics Data System (ADS)

Bhattacharyya, B.; Cooper, S.; Malenta, M.; Roy, J.; Chengalur, J.; Keith, M.; Kudale, S.; McLaughlin, M.; Ransom, S. M.; Ray, P. S.; Stappers, B. W.

2016-02-01

We are conducting a survey for pulsars and transients using the Giant Metrewave Radio Telescope (GMRT). The GMRT High Resolution Southern Sky (GHRSS) survey is an off-Galactic plane (| b| > 5) survey in the declination range -40° to -54° at 322 MHz. With the high time (up to 30.72 μs) and frequency (up to 0.016275 MHz) resolution observing modes, the 5σ detection limit is 0.5 mJy for a 2 ms pulsar with a 10% duty cycle at 322 MHz. The total GHRSS sky coverage of 2866 deg2 will result from 1953 pointings, each covering 1.8 deg2. The 10σ detection limit for a 5 ms transient burst is 1.6 Jy for the GHRSS survey. In addition, the GHRSS survey can reveal transient events like rotating radio transients or fast radio bursts. With 35% of the survey completed (I.e., 1000 deg2), we report the discovery of 10 pulsars, 1 of which is a millisecond pulsar (MSP), which is among the highest pulsar per square degree discovery rates for any off-Galactic plane survey. We re-detected 23 known in-beam pulsars. Utilizing the imaging capability of the GMRT, we also localized four of the GHRSS pulsars (including the MSP) in the gated image plane within ±10″. We demonstrated rapid convergence in pulsar timing with a more precise position than is possible with single-dish discoveries. We also show that we can localize the brightest transient sources with simultaneously obtained lower time resolution imaging data, demonstrating a technique that may have application in the Square Kilometre Array.

Enhancement of Attentional Performance by Selective Stimulation of α4β2* nAChRs: Underlying Cholinergic Mechanisms

PubMed Central

Howe, William M; Ji, Jinzhao; Parikh, Vinay; Williams, Sarah; Mocaër, Elisabeth; Trocmé-Thibierge, Caryn; Sarter, Martin

2010-01-01

Impairments in attention are a major component of the cognitive symptoms of neuropsychiatric and neurodegenerative disorders. Using an operant sustained attention task (SAT), including a distractor condition (dSAT), we assessed the putative pro-attentional effects of the selective α4β2* nicotinic acetylcholine receptor (nAChR) agonist S 38232 in comparison with the non-selective agonist nicotine. Neither drug benefited SAT performance. However, in interaction with the increased task demands implemented by distractor presentation, the selective agonist, but not nicotine, enhanced the detection of signals during the post-distractor recovery period. This effect is consistent with the hypothesis that second-long increases in cholinergic activity (‘transients') mediate the detection of cues and that nAChR agonists augment such transients. Electrochemical recordings of prefrontal cholinergic transients evoked by S 38232 and nicotine indicated that the α4β2* nAChR agonist evoked cholinergic transients that were characterized by a faster rise time and more rapid decay than those evoked by nicotine. Blockade of the α7 nAChR ‘sharpens' nicotine-evoked transients; therefore, we determined the effects of co-administration of nicotine and the α7 nAChR antagonist methyllycaconitine on dSAT performance. Compared with vehicle and nicotine alone, this combined treatment significantly enhanced the detection of signals. These results indicate that compared with nicotine, α4β2* nAChR agonists significantly enhance attentional performance and that the dSAT represents a useful behavioral screening tool. The combined behavioral and electrochemical evidence supports the hypothesis that nAChR agonist-evoked cholinergic transients, which are characterized by rapid rise time and fast decay, predict robust drug-induced enhancement of attentional performance. PMID:20147893

[Clinical and sperm follow-up after subinguinal varicocelectomy].

PubMed

Vicari, E; Arancio, A; Costanzo, C; Ingrassia, G; Cannizzaro, M A

2000-06-01

In order to evaluate the sperm output and the adverse-side-effects after subinguinal varicoceloctomy, a follow-up study of 16 months was performed on 196 selected patients (aged from 22 to 43 years) affected by left varicocele (VR). In the pre-treatment, both Doppler ultrasonography and didymo-epididymal ultrasonography allowed to distinguish two homogeneous patient groups: group A (no. = 136), including patients affected by VR alone and, group B (n. = 60), including patients with VR combined to coincidental didymo-epididymal morphological abnormalities, DEMA). These DEMA lesions (testis size < 12 ml, epididymides abnormalities: increased head- > or = 12 mm- and/or tail- > or = 6 mm-diameter, multiple microcysts, large idrocele) were omolaterally to VR in 30/60 (50%), eterolaterally in 19/60 (31.7%) or bilaterally in 11/60 (18.3%). During sperm follow-up, group A patients showed both a significant temporal change (p < 0.01 ANOVA) of all sperm parameters studied (sperm density, total sperm count, motility and morphology) from month 8 onward and sperm values significantly higher than found in group B patients. On the contrary, the sperm parameters of group B patients did not change significantly during the follow-up observations. As far as the varicocelectomy-mediated clinical symptoms, some patients complained early and transiently (on 1-2-4 weeks following varicocelectomy) the following symptoms: didymal pain (1.5%), didymo-epididymal pain (4.1%) and parasthesiaes on the anterior-medial side of the left thigh (4.1%) or scrotal (3.1%); only four patients (2%) complained permanent paresthesiaes on the anterior-medial side of the left thigh. Furthermore, the clinical follow-up also revealed a low rate of complications: persistent VR (3.6%), hydrocele (1.5%), intrascrotal venous ecstasies (6.1%), epididymitis (0.5%). Some morpho-structural abnormalities at US scans were transient (1-2 weeks): scrotal oedema (6.1%), orchitis (2%), orchi-epididymitis (1%). Subinguinal varicocelectomy performed on large population demonstrated a significant improvement of the sperm output from month 8th onward in patients with VR alone, while sperm parameters did not show any significant change in patients with VR plus coincidental DEMA. This surgical technique also demonstrated safety since both low rates of symptoms and (transient) complications were registered.

Mapping the "Depression Switch" During Intraoperative Testing of Subcallosal Cingulate Deep Brain Stimulation.

PubMed

Choi, Ki Sueng; Riva-Posse, Patricio; Gross, Robert E; Mayberg, Helen S

2015-11-01

The clinical utility of monitoring behavioral changes during intraoperative testing of subcallosal cingulate deep brain stimulation is unknown. To characterize the structural connectivity correlates of deep brain stimulation-evoked behavioral effects using probabilistic tractography in depression. Categorization of acute behavioral effects was conducted in 9 adults undergoing deep brain stimulation implantation surgery for chronic treatment-resistant depression in a randomized and blinded testing session at Emory University. Patients were studied from September 1, 2011, through June 30, 2013. Post hoc analyses of the structural tractography patterns mediating distinct categories of evoked behavioral effects were defined, including the best response overall. Data analyses were performed from May 1 through July 1, 2015. Categorization of stimulation-induced transient behavioral effects and delineation of the shared white matter tracts mediating response subtypes. Among the 9 patients, 72 active and 36 sham trials were recorded. The following stereotypical behavior patterns were identified: changes in interoceptive (noted changes in body state in 30 of 72 active and 4 of 36 sham trials) and in exteroceptive (shift in attention from patient to others in 9 of 72 active and 0 sham trials) awareness. The best response was a combination of exteroceptive and interoceptive changes at a single left contact for all 9 patients. Structural connectivity showed that the best response contacts had a pattern of connections to the bilateral ventromedial frontal cortex (via forceps minor and left uncinate fasciculus) and to the cingulate cortex (via left cingulum bundle), whereas behaviorally salient but nonbest contacts had only cingulate involvement. The involvement of the 3 white matter bundles during stimulation of the best contacts suggests a mechanism for the observed transient "depression switch." This analysis of transient behavior changes during intraoperative deep brain stimulation of the subcallosal cingulate and the subsequent identification of unique connectivity patterns may provide a biomarker of a rapid-onset depression switch to guide surgical implantation and to refine and optimize algorithms for the selection of contacts in long-term stimulation for treatment-resistant depression.

Cortico-subcortical organization of language networks in the right hemisphere: an electrostimulation study in left-handers.

PubMed

Duffau, Hugues; Leroy, Marianne; Gatignol, Peggy

2008-12-01

We have studied the configuration of the cortico-subcortical language networks within the right hemisphere (RH) in nine left-handers, being operated on while awake for a cerebral glioma. Intraoperatively, language was mapped using cortico-subcortical electrostimulation, to avoid permanent deficit. In frontal regions, cortical stimulation elicited articulatory disorders (ventral premotor cortex), anomia (dorsal premotor cortex), speech arrest (pars opercularis), and semantic paraphasia (dorsolateral prefrontal cortex). Insular stimulation generated dysarthria, parietal stimulation phonemic paraphasias, and temporal stimulation semantic paraphasias. Subcortically, the superior longitudinal fasciculus (inducing phonological disturbances when stimulated), inferior occipito-frontal fasciculus (eliciting semantic disturbances during stimulation), subcallosal fasciculus (generating control disturbances when stimulated), and common final pathway (inducing articulatory disorders during stimulation) were identified. These cortical and subcortical structures were preserved, avoiding permanent aphasia, despite a transient immediate postoperative language worsening. Both intraoperative results and postsurgical transitory dysphasia support the major role of the RH in language in left-handers, and provide new insights into the anatomo-functional cortico-subcortical organization of the language networks in the RH-suggesting a "mirror" configuration in comparison to the left hemisphere.

The Influences of Glycosylation on the Antigenicity, Immunogenicity, and Protective Efficacy of Ebola Virus GP DNA Vaccines

DTIC Science & Technology

2006-11-22

multiple muta- tions were not studied, (iii) a vaccinia virus (VACV)- T7 system was used for transient expression, (iv) pseudotyped retrovi- ruses were used...those studies produced little to no detectable GP1 or GP2 in the transient VACV- T7 expression assays, whereas in our studies with the DNA con- structs...type GP2 was detected in pseudotyped retroviruses, a result seemingly in conflict with these authors’ findings with the VACV- T7 expression. Although

Spitzer Characterization of Transients from the Palomar Transient Factory

NASA Astrophysics Data System (ADS)

Kasliwal, Mansi; Ofek, Eran; Corsi, Alessandra; Nugent, Peter; Kulkarni, Shri; Cao, Yi; Helou, George; Gal-Yam, Avishay; Arcavi, Iair; Ben-Ami, Sagi

2012-12-01

We propose to continue Spitzer/IRAC follow-up of optical transients discovered by the Palomar Transient Factory. Our goals are: (i) probe the mass loss history and characterize the circumstellar environment of supernovae. (ii) construct a late-time bolometric light curve; the mid-infrared observations complement our ground-based optical and near-infrared data and (iii) understand the physical origin of new classes of transients (specifically, intermediate luminosity red transients) where the mystery is literally enshrouded in dust. We select extremely nearby supernovae, both thermonuclear and core-collapse, where the thermal echo is easily detectable in the mid-infrared. We also select peculiar supernovae that show tell-tale signs of circumstellar interaction. We also select rare and red gap transients in the local universe for IRAC follow-up. Additionally, we request low-impact target of opportunity observations for new discoveries in 2013. Our total request is 24 hrs.

Spitzer Characterization of Transients from the Palomar Transient Factory

NASA Astrophysics Data System (ADS)

Kasliwal, Mansi; Goobar, Ariel; Johansson, Joel; Cenko, Brad; Ofek, Eran; Nugent, Peter; Kulkarni, Shri; Cao, Yi; Helou, George; Gal-Yam, Avishay; Arcavi, Iair; Ben-Ami, Sagi

2013-10-01

We propose to continue Spitzer/IRAC follow-up of optical transients discovered by the Palomar Transient Factory. Our goals are: (i) probe the mass loss history and characterize the circumstellar environment of supernovae. (ii) construct a late-time bolometric light curve; the mid-infrared observations complement our ground-based optical and near-infrared data and (iii) understand the physical origin of new classes of transients (specifically, intermediate luminosity red transients) where the mystery is literally enshrouded in dust. We select extremely nearby supernovae, both thermonuclear and core-collapse, where the thermal echo is easily detectable in the mid-infrared. We also select peculiar supernovae that show tell-tale signs of circumstellar interaction. We also select rare and red gap transients in the local universe. Additionally, we request low-impact target of opportunity observations for new discoveries in 2014. Our total request is 17 hrs.

Location identification of closed crack based on Duffing oscillator transient transition

NASA Astrophysics Data System (ADS)

Liu, Xiaofeng; Bo, Lin; Liu, Yaolu; Zhao, Youxuan; Zhang, Jun; Deng, Mingxi; Hu, Ning

2018-02-01

The existence of a closed micro-crack in plates can be detected by using the nonlinear harmonic characteristics of the Lamb wave. However, its location identification is difficult. By considering the transient nonlinear Lamb under the noise interference, we proposed a location identification method for the closed crack based on the quantitative measurement of Duffing oscillator transient transfer in the phase space. The sliding short-time window was used to create a window truncation of to-be-detected signal. And then, the periodic extension processing for transient nonlinear Lamb wave was performed to ensure that the Duffing oscillator has adequate response time to reach a steady state. The transient autocorrelation method was used to reduce the occurrence of missed harmonic detection due to the random variable phase of nonlinear Lamb wave. Moreover, to overcome the deficiency in the quantitative analysis of Duffing system state by phase trajectory diagram and eliminate the misjudgment caused by harmonic frequency component contained in broadband noise, logic operation method of oscillator state transition function based on circular zone partition was adopted to establish the mapping relation between the oscillator transition state and the nonlinear harmonic time domain information. Final state transition discriminant function of Duffing oscillator was used as basis for identifying the reflected and transmitted harmonics from the crack. Chirplet time-frequency analysis was conducted to identify the mode of generated harmonics and determine the propagation speed. Through these steps, accurate position identification of the closed crack was achieved.

realfast: Real-time, Commensal Fast Transient Surveys with the Very Large Array

NASA Astrophysics Data System (ADS)

Law, C. J.; Bower, G. C.; Burke-Spolaor, S.; Butler, B. J.; Demorest, P.; Halle, A.; Khudikyan, S.; Lazio, T. J. W.; Pokorny, M.; Robnett, J.; Rupen, M. P.

2018-05-01

Radio interferometers have the ability to precisely localize and better characterize the properties of sources. This ability is having a powerful impact on the study of fast radio transients, where a few milliseconds of data is enough to pinpoint a source at cosmological distances. However, recording interferometric data at millisecond cadence produces a terabyte-per-hour data stream that strains networks, computing systems, and archives. This challenge mirrors that of other domains of science, where the science scope is limited by the computational architecture as much as the physical processes at play. Here, we present a solution to this problem in the context of radio transients: realfast, a commensal, fast transient search system at the Jansky Very Large Array. realfast uses a novel architecture to distribute fast-sampled interferometric data to a 32-node, 64-GPU cluster for real-time imaging and transient detection. By detecting transients in situ, we can trigger the recording of data for those rare, brief instants when the event occurs and reduce the recorded data volume by a factor of 1000. This makes it possible to commensally search a data stream that would otherwise be impossible to record. This system will search for millisecond transients in more than 1000 hr of data per year, potentially localizing several Fast Radio Bursts, pulsars, and other sources of impulsive radio emission. We describe the science scope for realfast, the system design, expected outcomes, and ways in which real-time analysis can help in other fields of astrophysics.

Effective image differencing with convolutional neural networks for real-time transient hunting

NASA Astrophysics Data System (ADS)

Sedaghat, Nima; Mahabal, Ashish

2018-06-01

Large sky surveys are increasingly relying on image subtraction pipelines for real-time (and archival) transient detection. In this process one has to contend with varying point-spread function (PSF) and small brightness variations in many sources, as well as artefacts resulting from saturated stars and, in general, matching errors. Very often the differencing is done with a reference image that is deeper than individual images and the attendant difference in noise characteristics can also lead to artefacts. We present here a deep-learning approach to transient detection that encapsulates all the steps of a traditional image-subtraction pipeline - image registration, background subtraction, noise removal, PSF matching and subtraction - in a single real-time convolutional network. Once trained, the method works lightening-fast and, given that it performs multiple steps in one go, the time saved and false positives eliminated for multi-CCD surveys like Zwicky Transient Facility and Large Synoptic Survey Telescope will be immense, as millions of subtractions will be needed per night.

Transient Astrophysics Probe

NASA Astrophysics Data System (ADS)

Camp, Jordan; Transient Astrophysics Probe Team

2018-01-01

The Transient Astrophysics Probe (TAP) is a wide-field multi-wavelength transient mission proposed for flight starting in the late 2020s. The mission instruments include unique “Lobster-eye” imaging soft X-ray optics that allow a ~1600 deg2 FoV; a high sensitivity, 1 deg2 FoV soft X-ray telescope; a 1 deg2 FoV Infrared telescope with bandpass 0.6-3 micron; and a set of 8 NaI gamma-ray detectors. TAP’s most exciting capability will be the observation of tens per year of X-ray and IR counterparts of GWs involving stellar mass black holes and neutron stars detected by LIGO/Virgo/KAGRA/LIGO-India, and possibly several per year X-ray counterparts of GWs from supermassive black holes, detected by LISA and Pulsar Timing Arrays. TAP will also discover hundreds of X-ray transients related to compact objects, including tidal disruption events, supernova shock breakouts, and Gamma-Ray Bursts from the epoch of reionization.

Transient GFP expression in Nicotiana plumbaginifolia suspension cells: the role of gene silencing, cell death and T-DNA loss.

PubMed

Weld, R; Heinemann, J; Eady, C

2001-03-01

The transient nature of T-DNA expression was studied with a gfp reporter gene transferred to Nicotiana plumbaginifolia suspension cells from Agrobacterium tumefaciens. Individual GFP-expressing protoplasts were isolated after 4 days' co-cultivation. The protoplasts were cultured without selection and 4 weeks later the surviving proto-calluses were again screened for GFP expression. Of the proto-calluses initially expressing GFP, 50% had lost detectable GFP activity during the first 4 weeks of culture. Multiple T-DNA copies of the gfp gene were detected in 10 of 17 proto-calluses lacking visible GFP activity. The remaining 7 cell lines contained no gfp sequences. Our results confirm that transiently expressed T-DNAs can be lost during growth of somatic cells and demonstrate that transiently expressing cells frequently integrate multiple T-DNAs that become silenced. In cells competent for DNA uptake, cell death and gene silencing were more important barriers to the recovery of stably expressing transformants than lack of T-DNA integration.

Assessment of Impulse Noise Level and Acoustic Trauma in Military Personnel

PubMed Central

Rezaee, Maryam; Mojtahed, Mohammad; Ghasemi, Mohammad; Saedi, Babak

2012-01-01

Background: Military personnel are usually exposed to high levels of impulse noise (IN) which can lead to hearing loss. Objectives: The purpose of this study was to assess the effects of relatively low level exposure of impulse noise (IN) during shooting practice on hearing using pure tone audiometry (PTA) and transiently evoked otoacoustic emission (TEOAE) in military personnel. Materials and Methods: Forty male soldiers (mean age 20.08 years) were recruited for the study. Prior to their first shooting practice, PTA and TEOAE were recorded. After 15 minutes and one week post- practice PTA and TEOAE were compared. Results: Immediately after shooting practice significant differences in PTA at 500, 1000, and 4000 Hz were observed for the right ear and no significant difference at any frequency for the left ear. There was a significant difference in the amplitude of TEOAE 15 minutes after shooting practice at 500, 1000, 2000, 3000, and 4000 Hz in the right ear, while for the left ear the difference was significant at 1000 and 2000 Hz. One week after exposure a significant difference at 500 and 4000 Hz was found only in the right ear and a significant difference in the amplitude of TEOAE was observed at 500, 1000, 2000, 3000, and 4000 Hz. Conclusions: Even exposure lower than permissible levels may lead to acoustic trauma. TEOAE is more sensitive than PTA in detecting early hearing loss after military shooting exercises. Hearing protection equipment and appropriate surveillance programs are recommended. PMID:24749098

Characteristics of right-sided colonic neoplasia and colonoscopy barriers limiting their early detection and prognosis: a review of the literature.

PubMed

Fischbach, Wolfgang; Elsome, Rory; Amlani, Bharat

2018-06-05

Colonoscopy provides less protection from colorectal cancer in the right colon than the left. Areas covered: This review examines patient outcomes and colonoscopy success rates to identify factors that limit the protective effect of colonoscopy in the right colon. The MEDLINE and Embase databases were searched for literature from 2000 onwards, on the long-term outcomes and differences in screening practice between the right and left colon. In total, 12 systematic reviews (including nine meta-analyses) and 44 primary data records were included. Differences in patient outcomes and colonoscopy practice were identified between the right and left colon, suggesting that several factors, many of which disproportionally affect the right colon, impact lesion detection rates. Shorter withdrawal times reduce detection rates, while longer times significantly increase detection; mostly of adenomas in the right colon. Colonoscope attachments often only show a significant improvement in detection rates in the right colon, suggesting detection is more challenging due to visibility of the right colonic mucosa. Higher bowel cleansing grades significantly improve detection rates in the right colon compared to the left. Expert commentary: These findings confirm the need for continued improvement of colonoscopy effectiveness, and obligatory quality assessment, overall and especially in the right colon.

Detection of atrial fibrillation after ischemic stroke or transient ischemic attack: a systematic review and meta-analysis.

PubMed

Kishore, Amit; Vail, Andy; Majid, Arshad; Dawson, Jesse; Lees, Kennedy R; Tyrrell, Pippa J; Smith, Craig J

2014-02-01

Atrial fibrillation (AF) confers a high risk of recurrent stroke, although detection methods and definitions of paroxysmal AF during screening vary. We therefore undertook a systematic review and meta-analysis to determine the frequency of newly detected AF using noninvasive or invasive cardiac monitoring after ischemic stroke or transient ischemic attack. Prospective observational studies or randomized controlled trials of patients with ischemic stroke, transient ischemic attack, or both, who underwent any cardiac monitoring for a minimum of 12 hours, were included after electronic searches of multiple databases. The primary outcome was detection of any new AF during the monitoring period. We prespecified subgroup analysis of selected (prescreened or cryptogenic) versus unselected patients and according to duration of monitoring. A total of 32 studies were analyzed. The overall detection rate of any AF was 11.5% (95% confidence interval, 8.9%-14.3%), although the timing, duration, method of monitoring, and reporting of diagnostic criteria used for paroxysmal AF varied. Detection rates were higher in selected (13.4%; 95% confidence interval, 9.0%-18.4%) than in unselected patients (6.2%; 95% confidence interval, 4.4%-8.3%). There was substantial heterogeneity even within specified subgroups. Detection of AF was highly variable, and the review was limited by small sample sizes and marked heterogeneity. Further studies are required to inform patient selection, optimal timing, methods, and duration of monitoring for detection of AF/paroxysmal AF.

Cosmic Explosions (Optical)

NASA Astrophysics Data System (ADS)

Kulkarni, S. R.

2012-04-01

One of the principal motivations of wide-field and synoptic surveys is the search for, and study of, transients. By transients I mean those sources that arise from the background, are detectable for some time, and then fade away to oblivion. Transients in distant galaxies need to be sufficiently bright as to be detectable, and in almost all cases those transients are catastrophic events, marking the deaths of stars. Exemplars include supernovæ and gamma-ray bursts. In our own Galaxy, the transients are strongly variable stars, and in almost all cases are at best cataclysmic rather than catastrophic. Exemplars include flares from M dwarfs, novæ of all sorts (dwarf novæ, recurrent novæ, classical novæ, X-ray novæ) and instabilities in the surface layers of stars such as S Dor or η Carina. In the nearby Universe (say out to the Virgo cluster) we have sufficient sensitivity to see novæ. In 1 I review the history of transients (which is intimately related to the advent of wide-field telescopic imaging). In 2 I summarize wide-field imaging projects, and I then review the motivations that led to the design of the Palomar Transient Factory (PTF). Next comes a summary of the astronomical returns from PTF (3), and that is followed by lessons that I have learnt from PTF (4). I conclude that, during this decade, the study of optical transients will continue to flourish (and may even accelerate as surveys at other wavelengths-notably radio, UV and X-ray-come on-line). Furthermore, it is highly likely that there will be a proliferation of highly-specialized searches for transients. Those searches may well remain active even in the era of LSST (5). I end the article by discussing the importance of follow-up telescopes for transient object studies-a topical issue, given the Portfolio Review that is being undertaken in the US.

Towards Development of a 3-State Self-Paced Brain-Computer Interface

PubMed Central

Bashashati, Ali; Ward, Rabab K.; Birch, Gary E.

2007-01-01

Most existing brain-computer interfaces (BCIs) detect specific mental activity in a so-called synchronous paradigm. Unlike synchronous systems which are operational at specific system-defined periods, self-paced (asynchronous) interfaces have the advantage of being operational at all times. The low-frequency asynchronous switch design (LF-ASD) is a 2-state self-paced BCI that detects the presence of a specific finger movement in the ongoing EEG. Recent evaluations of the 2-state LF-ASD show an average true positive rate of 41% at the fixed false positive rate of 1%. This paper proposes two designs for a 3-state self-paced BCI that is capable of handling idle brain state. The two proposed designs aim at detecting right- and left-hand extensions from the ongoing EEG. They are formed of two consecutive detectors. The first detects the presence of a right- or a left-hand movement and the second classifies the detected movement as a right or a left one. In an offline analysis of the EEG data collected from four able-bodied individuals, the 3-state brain-computer interface shows a comparable performance with a 2-state system and significant performance improvement if used as a 2-state BCI, that is, in detecting the presence of a right- or a left-hand movement (regardless of the type of movement). It has an average true positive rate of 37.5% and 42.8% (at false positives rate of 1%) in detecting right- and left-hand extensions, respectively, in the context of a 3-state self-paced BCI and average detection rate of 58.1% (at false positive rate of 1%) in the context of a 2-state self-paced BCI. PMID:18288260

Limits on radio emission from meteors using the MWA

NASA Astrophysics Data System (ADS)

Zhang, Xiang; Hancock, Paul; Devillepoix, Hadrien A. R.; Wayth, Randall B.; Beardsley, A.; Crosse, B.; Emrich, D.; Franzen, T. M. O.; Gaensler, B. M.; Horsley, L.; Johnston-Hollitt, M.; Kaplan, D. L.; Kenney, D.; Morales, M. F.; Pallot, D.; Steele, K.; Tingay, S. J.; Trott, C. M.; Walker, M.; Williams, A.; Wu, C.; Ji, Jianghui; Ma, Yuehua

2018-04-01

Recently, low frequency, broadband radio emission has been observed accompanying bright meteors by the Long Wavelength Array (LWA). The broadband spectra between 20 and 60 MHz were captured for several events, while the spectral index (dependence of flux density on frequency, with Sν∝να) was estimated to be -4 ± 1 during the peak of meteor afterglows. Here we present a survey of meteor emission and other transient events using the Murchison Widefield Array (MWA) at 72-103 MHz. In our 322-hour survey, down to a 5σ detection threshold of 3.5 Jy/beam, no transient candidates were identified as intrinsic emission from meteors. We derived an upper limit of -3.7 (95% confidence limit) on the spectral index in our frequency range. We also report detections of other transient events, like reflected FM broadcast signals from small satellites, conclusively demonstrating the ability of the MWA to detect and track space debris on scales as small as 0.1 m in low Earth orbits.

Weak Fault Feature Extraction of Rolling Bearings Based on an Improved Kurtogram

PubMed Central

Chen, Xianglong; Feng, Fuzhou; Zhang, Bingzhi

2016-01-01

Kurtograms have been verified to be an efficient tool in bearing fault detection and diagnosis because of their superiority in extracting transient features. However, the short-time Fourier Transform is insufficient in time-frequency analysis and kurtosis is deficient in detecting cyclic transients. Those factors weaken the performance of the original kurtogram in extracting weak fault features. Correlated Kurtosis (CK) is then designed, as a more effective solution, in detecting cyclic transients. Redundant Second Generation Wavelet Packet Transform (RSGWPT) is deemed to be effective in capturing more detailed local time-frequency description of the signal, and restricting the frequency aliasing components of the analysis results. The authors in this manuscript, combining the CK with the RSGWPT, propose an improved kurtogram to extract weak fault features from bearing vibration signals. The analysis of simulation signals and real application cases demonstrate that the proposed method is relatively more accurate and effective in extracting weak fault features. PMID:27649171

Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence

NASA Astrophysics Data System (ADS)

Patcharoen, Theerasak; Yoomak, Suntiti; Ngaopitakkul, Atthapol; Pothisarn, Chaichan

2018-04-01

This paper describes the combination of discrete wavelet transforms (DWT) and artificial intelligence (AI), which are efficient techniques to identify the type of inrush current, analyze the origin and possible cause on the capacitor bank switching. The experiment setup used to verify the proposed techniques can be detected and classified the transient inrush current from normal capacitor rated current. The discrete wavelet transforms are used to detect and classify the inrush current. Then, output from wavelet is acted as input of fuzzy inference system for discriminating the type of switching transient inrush current. The proposed technique shows enhanced performance with a discrimination accuracy of 90.57%. Both simulation study and experimental results are quite satisfactory with providing the high accuracy and reliability which can be developed and implemented into a numerical overcurrent (50/51) and unbalanced current (60C) protection relay for an application of shunt capacitor bank protection in the future.

Cholinergic Interneurons Underlie Spontaneous Dopamine Release in Nucleus Accumbens

PubMed Central

2017-01-01

The release of dopamine from terminals in the NAc is regulated by a number of factors, including voltage-gated ion channels, D2-autoreceptors, and nAChRs. Cholinergic interneurons (CINs) drive dopamine release through activation of nAChRs on dopamine terminals. Using cyclic voltammetry in mouse brain slices, nAChR-dependent spontaneous dopamine transients and the mechanisms underlying the origin were examined in the NAc. Spontaneous events were infrequent (0.3 per minute), but the rate and amplitude were increased after blocking Kv channels with 4-aminopyridine. Although the firing frequency of CINs was increased by blocking glutamate reuptake with TBOA and the Sk blocker apamin, only 4-aminopyridine increased the frequency of dopamine transients. In contrast, inhibition of CIN firing with the μ/δ selective opioid [Met5]enkephalin (1 μm) decreased spontaneous dopamine transients. Cocaine increased the rate and amplitude of dopamine transients, suggesting that the activity of the dopamine transporter limits the detection of these events. In the presence of cocaine, the rate of spontaneous dopamine transients was further increased after blocking D2-autoreceptors. Blockade of muscarinic receptors had no effect on evoked dopamine release, suggesting that feedback inhibition of acetylcholine release was not involved. Thus, although spontaneous dopamine transients are reliant on nAChRs, the frequency was not strictly governed by the activity of CINs. The increase in frequency of spontaneous dopamine transients induced by cocaine was not due to an increase in cholinergic tone and is likely a product of an increase in detection resulting from decreased dopamine reuptake. SIGNIFICANCE STATEMENT The actions of dopamine in the NAc are thought to be responsible for endogenous reward and the reinforcing properties of drugs of abuse, such as psychostimulants. The present work examines the mechanisms underlying nAChR-induced spontaneous dopamine release. This study demonstrates that spontaneous dopamine release is (1) dependent of the activation of nicotinic receptors, (2) independent on the spontaneous activity of cholinergic interneurons, and (3) that cocaine increased the detection of dopamine transients by prolonging the presence and increasing the diffusion of dopamine in the extracellular space. The release of acetylcholine is therefore responsible for spontaneous dopamine transients, and cocaine augments dopamine tone without altering activity of cholinergic interneurons. PMID:28115487

A transient, flat spectrum radio pulsar near the Galactic Centre

NASA Astrophysics Data System (ADS)

Dexter, J.; Degenaar, N.; Kerr, M.; Deller, A.; Deneva, J.; Lazarus, P.; Kramer, M.; Champion, D.; Karuppusamy, R.

2017-06-01

Recent studies have shown possible connections between highly magnetized neutron stars ('magnetars'), whose X-ray emission is too bright to be powered by rotational energy, and ordinary radio pulsars. In addition to the magnetar SGR J1745-2900, one of the radio pulsars in the Galactic Centre (GC) region, PSR J1746-2850, had timing properties implying a large magnetic field strength and young age, as well as a flat spectrum. All characteristics are similar to those of rare, transient, radio-loud magnetars. Using several deep non-detections from the literature and two new detections, we show that this pulsar is also transient in the radio. Both the flat spectrum and large amplitude variability are inconsistent with the light curves and spectral indices of three radio pulsars with high magnetic field strengths. We further use frequent, deep archival imaging observations of the GC in the past 15 yr to rule out a possible X-ray outburst with a luminosity exceeding the rotational spin-down rate. This source, either a transient magnetar without any detected X-ray counterpart or a young, strongly magnetized radio pulsar producing magnetar-like radio emission, further blurs the line between the two categories. We discuss the implications of this object for the radio emission mechanism in magnetars and for star and compact object formation in the GC.

ARECIBO PULSAR SURVEY USING ALFA: PROBING RADIO PULSAR INTERMITTENCY AND TRANSIENTS

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

Deneva, J. S.; Cordes, J. M.; McLaughlin, M. A.

We present radio transient search algorithms, results, and statistics from the ongoing Arecibo Pulsar ALFA (PALFA) survey of the Galactic plane. We have discovered seven objects through a search for isolated dispersed pulses. All of these objects are Galactic and have measured periods between 0.4 and 4.7 s. One of the new discoveries has a duty cycle of 0.01%, smaller than that of any other radio pulsar. We discuss the impact of selection effects on the detectability and classification of intermittent sources, and compare the efficiencies of periodicity and single-pulse (SP) searches for various pulsar classes. For some cases wemore » find that the apparent intermittency is likely to be caused by off-axis detection or a short time window that selects only a few bright pulses and favors detection with our SP algorithm. In other cases, the intermittency appears to be intrinsic to the source. No transients were found with DMs large enough to require that they originate from sources outside our Galaxy. Accounting for the on-axis gain of the ALFA system, as well as the low gain but large solid-angle coverage of far-out sidelobes, we use the results of the survey so far to place limits on the amplitudes and event rates of transients of arbitrary origin.« less

Discovery of ZTF18abauprj, a young Type Ia supernova in NGC 6279

NASA Astrophysics Data System (ADS)

Miller, A. A.; Graham, M.; Bellm, E.; Ho, A.; Adams, S. M.; De, K.; Fremling, C.; Kulkarni, S. R.; Perley, D. A.; Gal-Yam, A.; Gooba, A.

2018-06-01

We report the detection of a new transient candidate identified during routine operations of the Zwicky Transient Facility (ZTF; ATel #11266). The transient, named ZTF18abauprj, was discovered on 2018-06-15.25 UT with g = 19.4 mag. ZTF18abauprj is located at R.A., Dec = 16:59:05.07 +47:14:11.1 (J2000), roughly 37.5 arcsec ( 19 kpc) from the nucleus of NGC 6279.

Distinguishing transient signals and instrumental disturbances in semi-coherent searches for continuous gravitational waves with line-robust statistics

NASA Astrophysics Data System (ADS)

Keitel, David

2016-05-01

Non-axisymmetries in rotating neutron stars emit quasi-monochromatic gravitational waves. These long-duration ‘continuous wave’ signals are among the main search targets of ground-based interferometric detectors. However, standard detection methods are susceptible to false alarms from instrumental artefacts that resemble a continuous-wave signal. Past work [Keitel, Prix, Papa, Leaci and Siddiqi 2014, Phys. Rev. D 89 064023] showed that a Bayesian approach, based on an explicit model of persistent single-detector disturbances, improves robustness against such artefacts. Since many strong outliers in semi-coherent searches of LIGO data are caused by transient disturbances that last only a few hours or days, I describe in a recent paper [Keitel D 2015, LIGO-P1500159] how to extend this approach to cover transient disturbances, and demonstrate increased sensitivity in realistic simulated data. Additionally, neutron stars could emit transient signals which, for a limited time, also follow the continuous-wave signal model. As a pragmatic alternative to specialized transient searches, I demonstrate how to make standard semi-coherent continuous-wave searches more sensitive to transient signals. Focusing on the time-scale of a single segment in the semi-coherent search, Bayesian model selection yields a simple detection statistic without a significant increase in computational cost. This proceedings contribution gives a brief overview of both works.

Is everything clear about Tako-tsubo syndrome?

PubMed

Petrov, Ivo S; Tokmakova, Mariya P; Marchov, Daniel N; Kichukov, Kostadin N

2011-01-01

Tako-tsubo syndrome is a novel cardio-vascular disease affecting predominantly postmenopausal women exposed to unexpected strong emotional or physical stress, in the absence of significant coronary heart disease. It is characterized by acute onset of severe chest pain and/or acute left ventricular failure, ECG-changes, typical left ventricular angiographic findings, good prognosis and positive resolution of the morphological and clinical manifestations. First described in 1990 in Japan by Sato, Tako-tsubo cardiomyopathy is characterized by transient contractile abnormalities of the left ventricle, causing typical left ventricular apical ballooning at end-systole with concomitant compensatory basal hyperkinesia. There are also atypical forms, presenting with left ventricular systolic dysfunction which affects the mid-portions of the left ventricle. The etiology of the disease still remains unclear. Many theories have been put forward about the potential underlying pathophysiological mechanisms that may trigger this syndrome among which are the theory of catecholamine excess, the theory of multivessel coronary vasospasm, the ischemic theory, and the theory of microvascular dysfunction and dynamic left ventricular gradient induced by elevated circulating catecholamine levels. Adequate management of Tako-tsubo syndrome demands immediate preparation for coronary angiography. Once the diagnosis is made, treatment is primarily symptomatic and includes monitoring for complications. Patients with Tako-tsubo syndrome most frequently develop acute LV failure, pulmonary edema, rhythm and conductive disturbances and apical thrombosis. Treatment is symptomatic and includes administration of diuretics, vasodilators and mechanical support of circulation with intra-aortic balloon counterpulsation.

Left insular cortex and left SFG underlie prismatic adaptation effects on time perception: evidence from fMRI.

PubMed

Magnani, Barbara; Frassinetti, Francesca; Ditye, Thomas; Oliveri, Massimiliano; Costantini, Marcello; Walsh, Vincent

2014-05-15

Prismatic adaptation (PA) has been shown to affect left-to-right spatial representations of temporal durations. A leftward aftereffect usually distorts time representation toward an underestimation, while rightward aftereffect usually results in an overestimation of temporal durations. Here, we used functional magnetic resonance imaging (fMRI) to study the neural mechanisms that underlie PA effects on time perception. Additionally, we investigated whether the effect of PA on time is transient or stable and, in the case of stability, which cortical areas are responsible of its maintenance. Functional brain images were acquired while participants (n=17) performed a time reproduction task and a control-task before, immediately after and 30 min after PA inducing a leftward aftereffect, administered outside the scanner. The leftward aftereffect induced an underestimation of time intervals that lasted for at least 30 min. The left anterior insula and the left superior frontal gyrus showed increased functional activation immediately after versus before PA in the time versus the control-task, suggesting these brain areas to be involved in the executive spatial manipulation of the representation of time. The left middle frontal gyrus showed an increase of activation after 30 min with respect to before PA. This suggests that this brain region may play a key role in the maintenance of the PA effect over time. Copyright © 2014. Published by Elsevier Inc.

A Study of Coronal-Interplanetary Coupling Mechanisms

DTIC Science & Technology

1991-04-30

Magnetic Feild in Astrophys. J., Vol. 344, 478-493, 1989. 111.3. Reflection and Trapping of Transient Alfven Waves Propagating in an Isothermal...1990. VI.4. A Comparison Between Progressive Extension Method (PEM) and Iterative Method (IM) for Magnetic Feild Extrapolations in the Solar...Flight Center. Representative results are shown in the upper left panel of Figure 1 in which (a) shows the observed vector magnetic field at photospheric

Influence of LVAD function on mechanical unloading and electromechanical delay: a simulation study.

PubMed

Heikhmakhtiar, Aulia Khamas; Ryu, Ah Jin; Shim, Eun Bo; Song, Kwang-Soup; Trayanova, Natalia A; Lim, Ki Moo

2018-05-01

This study hypothesized that a left ventricular assist device (LVAD) shortens the electromechanical delay (EMD) by mechanical unloading. The goal of this study is to examine, by computational modeling, the influence of LVAD on EMD for four heart failure (HF) cases ranging from mild HF to severe HF. We constructed an integrated model of an LVAD-implanted cardiovascular system, then we altered the Ca 2+ transient magnitude, with scaling factors 1, 0.9, 0.8, and 0.7 representing HF1, HF2, HF3, and HF4, respectively, in order of increasing HF severity. The four HF conditions are classified into two groups. Group one is the four HF conditions without LVAD, and group two is the conditions treated with continuous LVAD pump. The single-cell mechanical responses showed that EMD was prolonged with the higher load. The findings indicated that in group one, the HF-induced Ca2 + transient remodeling prolonged the mechanical activation time (MAT) and decreased the contractile tension, which reduced the left ventricle (LV) pressure, and increased the end-diastolic strain. In group two, LVAD shortened MAT of the ventricles. Furthermore, LVAD reduced the contractile tension, and end-diastolic strain, but increased the aortic pressure. The computational study demonstrated that LVAD shortens EMD by mechanical unloading of the ventricle.

Oblique rift opening revealed by reoccurring magma injection in central Iceland.

PubMed

Ruch, Joël; Wang, Teng; Xu, Wenbin; Hensch, Martin; Jónsson, Sigurjón

2016-08-05

Extension deficit builds up over centuries at divergent plate boundaries and is recurrently removed during rifting events, accompanied by magma intrusions and transient metre-scale deformation. However, information on transient near-field deformation has rarely been captured, hindering progress in understanding rifting mechanisms and evolution. Here we show new evidence of oblique rift opening during a rifting event influenced by pre-existing fractures and two centuries of extension deficit accumulation. This event originated from the Bárðarbunga caldera and led to the largest basaltic eruption in Iceland in >200 years. The results show that the opening was initially accompanied by left-lateral shear that ceased with increasing opening. Our results imply that pre-existing fractures play a key role in controlling oblique rift opening at divergent plate boundaries.

Semantic memory and frontal executive function during transient global amnesia.

PubMed

Hodges, J R

1994-05-01

To assess semantic memory and frontal executive function, two patients underwent neuropsychological testing during transient global amnesia (TGA) and after an interval of 6-8 weeks. In spite of a profound deficit in anterograde verbal and non-verbal memory, semantic memory was normal, as judged by category fluency measures, picture naming, and picture-word and picture-picture matching, and reading ability was normal. Similarly, there were no deficits on a number of tests known to be sensitive to frontal executive dysfunction. A hexamethylpropyleneamine-oxime (HMPAO) single photon emission CT (SPECT) scan, obtained on one patient 24 hours post-TGA, showed focal left temporal lobe hypoperfusion which had resolved three months later. The observed dissociation between episodic and semantic memory is discussed in the light of contemporary cognitive theories of memory organisation.

Successful treatment of refractory demodicosis and transient papules with a single dose of fluralaner in a dog with uncontrolled severe endocrine disease.

PubMed

Morita, Tatsushi; Momota, Yutaka; Mori, Akihiro; Oda, Hitomi; Ike, Kazunori; Sako, Toshinori

2018-04-27

A 12-year-old female Shih-Tzu with hyperadrenocorticism and hypothyroidism developed concurrent refractory generalized demodicosis that did not respond to doramectin treatment. Although amitraz treatment was effective, the dog developed severe diabetes, which resulted in the cessation of amitraz and trilostane. Attempts to control the diabetes were unsuccessful, and its hyperadrenocorticism was left untreated, leading to the recurrence of demodicosis. However, demodicosis went into complete remission with a single dose of fluralaner. Transient erythematous papules appeared on the trunk three days after the administration of fluralaner, but no other adverse reactions were noted. We demonstrated that fluralaner is a potent treatment for demodicosis, and skin eruptions are possible after the first dose of the drug.

Optical and X-ray early follow-up of ANTARES neutrino alerts

NASA Astrophysics Data System (ADS)

Adrián-Martínez, S.; Ageron, M.; Albert, A.; Samarai, I. Al; André, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bogazzi, C.; Bormuth, R.; Bou-Cabo, M.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Dekeyser, I.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Dumas, A.; Eberl, T.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fermani, P.; Folger, F.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Gracia-Ruiz, R.; Graf, K.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herrero, A.; Hößl, J.; Hofestädt, J.; Hugon, C.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Lattuada, D.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; Martini, S.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Neff, M.; Nezri, E.; Păvălaš, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Richter, R.; Roensch, K.; Rostovtsev, A.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schulte, S.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Tamburini, C.; Trovato, A.; Tselengidou, M.; Tönnis, C.; Turpin, D.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vecchi, M.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; Klotz, A.; Boer, M.; Le Van Suu, A.; Akerlof, C.; Zheng, W.; Evans, P.; Gehrels, N.; Kennea, J.; Osborne, J. P.; Coward, D. M.

2016-02-01

High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from a single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.

Optical and X-ray early follow-up of ANTARES neutrino alerts

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

Adrián-Martínez, S.; Ardid, M.; Ageron, M.

High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from amore » single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.« less

Usefulness of cardiotoxicity assessment using calcium transient in human induced pluripotent stem cell-derived cardiomyocytes.

PubMed

Watanabe, Hitoshi; Honda, Yayoi; Deguchi, Jiro; Yamada, Toru; Bando, Kiyoko

2017-01-01

Monitoring dramatic changes in intracellular calcium ion levels during cardiac contraction and relaxation, known as calcium transient, in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) would be an attractive strategy for assessing compounds on cardiac contractility. In addition, as arrhythmogenic compounds are known to induce characteristic waveform changes in hiPSC-CMs, it is expected that calcium transient would allow evaluation of not only compound-induced effects on cardiac contractility, but also compound arrhythmogenic potential. Using a combination of calcium transient in hiPSC-CMs and a fast kinetic fluorescence imaging detection system, we examined in this study changes in calcium transient waveforms induced by a series of 17 compounds that include positive/negative inotropic agents as well as cardiac ion channel activators/inhibitors. We found that all positive inotropic compounds induced an increase in peak frequency and/or peak amplitude. The effects of a negative inotropic compound could clearly be detected in the presence of a β-adrenergic receptor agonist. Furthermore, most arrhythmogenic compounds raised the ratio of peak decay time to peak rise time (D/R ratio) in calcium transient waveforms. Compound concentrations at which these parameters exceeded cutoff values correlated well with systemic exposure levels at which arrhythmias were reported to be evoked. In conclusion, we believe that peak analysis of calcium transient and determination of D/R ratio are reliable methods for assessing compounds' cardiac contractility and arrhythmogenic potential, respectively. Using these approaches would allow selection of compounds with low cardiotoxic potential at the early stage of drug discovery.

Sustained and transient attention in the continuous performance task.

PubMed

Smid, H G O M; de Witte, M R; Homminga, I; van den Bosch, R J

2006-08-01

One of the most frequently applied methods to study abnormal cognition is the Continuous Performance Task (CPT). It is unclear, however, which cognitive functions are engaged in normal CPT performance. The aims of the present study were to identify the neurocognitive functions engaged in the main variants of the CPT and to determine to what extent these variants differentially engage these functions. We hypothesized that the main CPT versions (CPT-X, CPT-AX, CPT-Identical Pairs) can be distinguished by whether they demand sustained or transient attention and sustained or transient response preparation. Transient attention to objects like letters or digits, that is, the need to switch attention to different objects from trial to trial, impairs target detection accuracy relative to sustained attention to a single object. Transient response preparation, that is, the possibility to switch response preparation on and off from trial to trial, improves response speed relative to having to sustain response preparation across all trials. Comparison of task performance and Event-Related brain Potentials (ERPs) of healthy participants obtained in the main CPT variants confirmed these hypotheses. Behavioral and ERP measures indicated worse target detection in the CPT-AX than in the CPT-X, consistent with a higher demand on transient attention in that task. In contrast, behavioral and ERP measures indicated higher response speed in the CPT-AX than in the CPT-X, associated with more response preparation in advance of the targets. This supports the idea of increased transient response preparation in the CPT-AX. We conclude that CPTs differ along at least two task variables that each influences a different cognitive function.

[A Comparison Study on Early Damage Detection of Left Ventricular Function Based on Doppler Imaging Method for Children with Tumor].

PubMed

Liu, Ying; Zhang, Haowei; Zhang, Hang

2015-12-01

The early damage detection and evaluation are of great significance in treatment and prognosis to the left ventricular function for children with tumor. In this paper, it is reported that the early damage of the left ventricular function was observed by pulsed wave Doppler (PWD) and tissue Doppler imaging (TDI) in our laboratory. Eighty children half a year to fourteen years old were included in this study. The cardiac function indices in chemotherapy group and control group were measured and compared. The results showed that there was significant difference in mitral and tricuspid annulus flow spectrum between the two groups. Compared with PWD,TDI is more prompt, objective and accurate in detecting early damage of left ventricular function in children with tumor. And TDI is a good method for early identification of ventricular function damage in children with tumor.

[Echocardiographic diagnosis of atrial thrombosis].

PubMed

Pinto Tortolero, R; Vargas Barrón, J; Rodas, M A; Díaz de la Vega, V; Horwitz, S

1982-01-01

Seventy patients with rheumatic mitral disease were studied by M-Mode and 2D echocardiography in order to detect left atrial thrombosis before surgery. Thrombosis were suspected by the observation of abnormal echoes in the left atrium. During surgery 17 (24%) patients had atrial thrombosis. It had been suspected by echocardiography in 12 (sensitivity 70%). In 53 patients thrombosis were not found during surgery; in 46 the echo had been also negative (specificity 86%). There was a false positive detection of thrombosis by echo in 7 patients (14%) and false negativity in 5 (30%). Patients with atrial thrombosis had atrial fibrilation in 91% of cases; and the most frequent valvular disease was mitral stenosis. There was not a direct relationship among existence of left atrial thrombosis and the anteroposterior diameter of the left atrium as measured by echo. We conclude that echocardiography has good specificity to rule out atrial thrombosis and moderate sensitivity to detect it in rheumatic mitral disease.

Swift/XRT detects a new accretion outburst of the Galactic center neutron star transient GRS 1741-2853

NASA Astrophysics Data System (ADS)

Degenaar, N.; Wijnands, R.; Reynolds, M. T.; Miller, J. M.; Kennea, J. A.

2017-10-01

Daily Swift/XRT monitoring observations of the Galactic center (Degenaar et al. 2015) have picked up renewed activity of the transient neutron star low-mass X-ray binary and thermonuclear X-ray burster GRS 1741-2853, which is located 10 arcmin NW of Sgr A*. During a 1 ks PC-mode observation performed on 2017 October 11 the source is detected at a net count rate of 0.015 counts/s and it has been steadily brightening since, indicating the onset of a new accretion outburst.

Fast transient analysis and first-stage collision-induced dissociation with the flowing atmospheric-pressure afterglow ionization source to improve analyte detection and identification.

PubMed

Shelley, Jacob T; Hieftje, Gary M

2010-04-01

The recent development of ambient desorption/ionization mass spectrometry (ADI-MS) has enabled fast, simple analysis of many different sample types. The ADI-MS sources have numerous advantages, including little or no required sample pre-treatment, simple mass spectra, and direct analysis of solids and liquids. However, problems of competitive ionization and limited fragmentation require sample-constituent separation, high mass accuracy, and/or tandem mass spectrometry (MS/MS) to detect, identify, and quantify unknown analytes. To maintain the inherent high throughput of ADI-MS, it is essential for the ion source/mass analyzer combination to measure fast transient signals and provide structural information. In the current study, the flowing atmospheric-pressure afterglow (FAPA) ionization source is coupled with a time-of-flight mass spectrometer (TOF-MS) to analyze fast transient signals (<500 ms FWHM). It was found that gas chromatography (GC) coupled with the FAPA source resulted in a reproducible (<5% RSD) and sensitive (detection limits of <6 fmol for a mixture of herbicides) system with analysis times of ca. 5 min. Introducing analytes to the FAPA in a transient was also shown to significantly reduce matrix effects caused by competitive ionization by minimizing the number and amount of constituents introduced into the ionization source. Additionally, MS/MS with FAPA-TOF-MS, enabling analyte identification, was performed via first-stage collision-induced dissociation (CID). Lastly, molecular and structural information was obtained across a fast transient peak by modulating the conditions that caused the first-stage CID.

Effect of Thermal Diffusivity on the Detectability of TNDE

NASA Technical Reports Server (NTRS)

Zhao, Junduo; Chu, Tsuchin; Russell, Samuel S.

2000-01-01

The effect of thermal diffusively on the defect detectability in Carbon/Epoxy composite panels by transient thermography is presented in this paper. A series of Finite Element Models were constructed and analyzed to simulate the transient heat transfer phenomenon during Thermographic Non-destructive Evaluation (TNDE) of composite panels with square defects. Six common carbon fibers were considered. The models were built for composites with various combinations of fibers and volumetric ratios. Finite Element Analysis of these models showed the trends of the detectable range and the maximum thermal contrast versus the thermal diffusivity of various composites. Additionally, the trends of defect size to depth ratio and the thermal contrast has been investigated.

Transient Dynamics Simulation of Airflow in a CT-Scanned Human Airway Tree: More or Fewer Terminal Bronchi?

PubMed Central

Zhang, Baihua; Li, Jianhua; Yue, Yong; Qian, Wei

2017-01-01

Using computational fluid dynamics (CFD) method, the feasibility of simulating transient airflow in a CT-based airway tree with more than 100 outlets for a whole respiratory period is studied, and the influence of truncations of terminal bronchi on CFD characteristics is investigated. After an airway model with 122 outlets is extracted from CT images, the transient airflow is simulated. Spatial and temporal variations of flow velocity, wall pressure, and wall shear stress are presented; the flow pattern and lobar distribution of air are gotten as well. All results are compared with those of a truncated model with 22 outlets. It is found that the flow pattern shows lobar heterogeneity that the near-wall air in the trachea is inhaled into the upper lobe while the center flow enters the other lobes, and the lobar distribution of air is significantly correlated with the outlet area ratio. The truncation decreases airflow to right and left upper lobes and increases the deviation of airflow distributions between inspiration and expiration. Simulating the transient airflow in an airway tree model with 122 bronchi using CFD is feasible. The model with more terminal bronchi decreases the difference between the lobar distributions at inspiration and at expiration. PMID:29333194

Congenital anomalies of the left brachiocephalic vein detected in adults on computed tomography.

PubMed

Yamamuro, Hiroshi; Ichikawa, Tamaki; Hashimoto, Jun; Ono, Shun; Nagata, Yoshimi; Kawada, Shuichi; Kobayashi, Makiko; Koizumi, Jun; Shibata, Takeo; Imai, Yutaka

2017-10-01

Anomalous left brachiocephalic vein (BCV) is a rare and less known systemic venous anomaly. We evaluated congenital anomalies of the left BCV in adults detected during computed tomography (CT) examinations. This retrospective study included 81,425 patients without congenital heart disease who underwent chest CT. We reviewed the recorded reports and CT images for congenital anomalies of the left BCV including aberrant and supernumerary BCVs. The associated congenital aortic anomalies were assessed. Among 73,407 cases at a university hospital, 22 (16 males, 6 females; mean age, 59 years) with aberrant left BCVs were found using keyword research on recorded reports (0.03%). Among 8018 cases at the branch hospital, 5 (4 males, 1 female; mean age, 67 years) with aberrant left BCVs were found using CT image review (0.062%). There were no significant differences in incidences of aberrant left BCV between the two groups. Two cases had double left BCVs. Eleven cases showed high aortic arches. Two cases had the right aortic arch, one case had an incomplete double aortic arch, and one case was associated with coarctation. Aberrant left BCV on CT examination in adults was extremely rare. Some cases were associated with aortic arch anomalies.

A serendipitous all sky survey for bright objects in the outer solar system

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

Brown, M. E.; Drake, A. J.; Djorgovski, S. G.

2015-02-01

We use seven year's worth of observations from the Catalina Sky Survey and the Siding Spring Survey covering most of the northern and southern hemisphere at galactic latitudes higher than 20° to search for serendipitously imaged moving objects in the outer solar system. These slowly moving objects would appear as stationary transients in these fast cadence asteroids surveys, so we develop methods to discover objects in the outer solar system using individual observations spaced by months, rather than spaced by hours, as is typically done. While we independently discover eight known bright objects in the outer solar system, the faintestmore » having V=19.8±0.1, no new objects are discovered. We find that the survey is nearly 100% efficient at detecting objects beyond 25 AU for V≲19.1 (V≲18.6 in the southern hemisphere) and that the probability that there is one or more remaining outer solar system object of this brightness left to be discovered in the unsurveyed regions of the galactic plane is approximately 32%.« less

Effects of Activation Energy to Transient Response of Semiconductor Gas Sensor

NASA Astrophysics Data System (ADS)

Fujimoto, Akira; Ohtani, Tatsuki

The smell classifiable gas sensor will be desired for many applications such as gas detection alarms, process controls for food production and so on. We have tried to realize the sensor using transient responses of semiconductor gas sensor consisting of tin dioxide and pointed out that the sensor gave us different transient responses for kinds of gas. Results of model calculation showed the activation energy of chemical reaction on the sensor surface strongly depended on the transient response. We tried to estimate the activation energies by molecular orbital calculation with SnO2 Cluster. The results show that there is a liner relationship between the gradient of the transient responses and activation energies for carboxylic and alcoholic gases. Transient response will be predicted from activation energy in the same kind of gas and the smell discrimination by single semiconductor gas sensor will be realized by this relationship.

Imaging of optically diffusive media by use of opto-elastography

NASA Astrophysics Data System (ADS)

Bossy, Emmanuel; Funke, Arik R.; Daoudi, Khalid; Tanter, Mickael; Fink, Mathias; Boccara, Claude

2007-02-01

We present a camera-based optical detection scheme designed to detect the transient motion created by the acoustic radiation force in elastic media. An optically diffusive tissue mimicking phantom was illuminated with coherent laser light, and a high speed camera (2 kHz frame rate) was used to acquire and cross-correlate consecutive speckle patterns. Time-resolved transient decorrelations of the optical speckle were measured as the results of localised motion induced in the medium by the radiation force and subsequent propagating shear waves. As opposed to classical acousto-optic techniques which are sensitive to vibrations induced by compressional waves at ultrasonic frequencies, the proposed technique is sensitive only to the low frequency transient motion induced in the medium by the radiation force. It therefore provides a way to assess both optical and shear mechanical properties.

Transient contribution of left posterior parietal cortex to cognitive restructuring

PubMed Central

Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

2015-01-01

Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring. PMID:25775998

Transient contribution of left posterior parietal cortex to cognitive restructuring.

PubMed

Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

2015-03-17

Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring.

Increasing contextual demand modulates anterior and lateral prefrontal brain regions associated with proactive interference.

PubMed

Wolf, Robert Christian; Walter, Henrik; Vasic, Nenad

2010-01-01

Using a parametric version of a modified item-recognition paradigm with three different load levels and by means of event-related functional magnetic resonance imaging, this study tested the hypothesis that cerebral activation associated with intratrial proactive interference (PI) during working memory retrieval is influenced by increased context processing. We found activation of left BA 45 during interference trials across all levels of cognitive processing, and left lateralized activation of the dorsolateral prefrontal cortex (DLPFC, BA 9/46) and the frontopolar cortex (FPC, BA 10) with increasing contextual load. Compared with high susceptibility to PI, low susceptibility was associated with activation of the left DLPFC. These results suggest that an intratrial PI effect can be modulated by increasing context processing of a transiently relevant stimulus set. Moreover, PI resolution associated with increasing context load involves multiple prefrontal regions including the ventro- and dorsolateral prefrontal cortex as well as frontopolar brain areas. Furthermore, low susceptibility to PI might be influenced by increased executive control exerted by the DLPFC.

Electrocardiography cannot reliably differentiate transient left ventricular apical ballooning syndrome from anterior ST-segment elevation myocardial infarction.

PubMed

Bybee, Kevin A; Motiei, Arashk; Syed, Imran S; Kara, Tomas; Prasad, Abhiram; Lennon, Ryan J; Murphy, Joseph G; Hammill, Stephen C; Rihal, Charanjit S; Wright, R Scott

2007-01-01

The presentation and electrocardiographic (ECG) characteristics of transient left ventricular apical ballooning syndrome (TLVABS) can be similar to that of anterior ST-segment elevation myocardial infarction (STEMI). We tested the hypothesis that the ECG on presentation could reliably differentiate these syndromes. Between January 1, 2002 and July 31, 2004, we identified 18 consecutive patients with TLVABS who were matched with 36 subjects presenting with acute anterior STEMI due to atherothrombotic left anterior descending coronary artery occlusion. All patients with TLVABS were women (mean age, 72.0 +/- 13.1 years). The heart rate, PR interval, QRS duration, and corrected QT interval were similar between groups. Distribution of ST elevation was similar, but patients with anterior STEMI exhibited greater ST elevation. Regressive partitioning analysis indicated that the combination of ST elevation in lead V2 of less than 1.75 mm and ST-segment elevation in lead V3 of less than 2.5 mm was a suggestive predictor of TLVABS (sensitivity, 67%; specificity, 94%). Conditional logistic regression indicated that the formula: (3 x ST-elevation lead V2) + (ST-elevation V3) + (2 x ST-elevation V5) allowed possible discrimination between TLVABS and anterior STEMI with an optimal cutoff level of less than 11.5 mm for TLVABS (sensitivity, 94%; specificity, 72%). Patients with TLVABS were less likely to have concurrent ST-segment depression (6% vs 44%; P = .003). Women presenting with TLVABS have similar ECG findings to patients with anterior infarct but with less-prominent ST-segment elevation in the anterior precordial ECG leads. These ECG findings are relatively subtle and do not have sufficient predictive value to allow reliable emergency differentiation of these syndromes.

Imagining the future: The core episodic simulation network dissociates as a function of timecourse and the amount of simulated information

PubMed Central

Thakral, Preston P.; Benoit, Roland G.; Schacter, Daniel L.

2017-01-01

Neuroimaging data indicate that episodic memory (i.e., remembering specific past experiences) and episodic simulation (i.e., imagining specific future experiences) are associated with enhanced activity in a common set of neural regions, often referred to as the core network. This network comprises the hippocampus, parahippocampal cortex, lateral and medial parietal cortex, lateral temporal cortex, and medial prefrontal cortex. Evidence for a core network has been taken as support for the idea that episodic memory and episodic simulation are supported by common processes. Much remains to be learned about how specific core network regions contribute to specific aspects of episodic simulation. Prior neuroimaging studies of episodic memory indicate that certain regions within the core network are differentially sensitive to the amount of information recollected (e.g., the left lateral parietal cortex). In addition, certain core network regions dissociate as a function of their timecourse of engagement during episodic memory (e.g., transient activity in the posterior hippocampus and sustained activity in the left lateral parietal cortex). In the current study, we assessed whether similar dissociations could be observed during episodic simulation. We found that the left lateral parietal cortex modulates as a function of the amount of simulated details. Of particular interest, while the hippocampus was insensitive to the amount of simulated details, we observed a temporal dissociation within the hippocampus: transient activity occurred in relatively posterior portions of the hippocampus and sustained activity occurred in anterior portions. Because the posterior hippocampal and lateral parietal findings parallel those observed previously during episodic memory, the present results add to the evidence that episodic memory and episodic simulation are supported by common processes. Critically, the present study also provides evidence that regions within the core network support dissociable processes. PMID:28324695

Asphyxia causes ultrasonographic D-shaping of the left ventricle--an experimental porcine study.

PubMed

Sørensen, A H; Wemmelund, K B; Møller-Helgestad, O K; Sloth, E; Juhl-Olsen, P

2016-02-01

In critical care, early diagnosis and correct treatment are of the utmost importance. Focused ultrasonography has gained acceptance as a pivotal tool for this by elucidating the underlying pathology. For example, massive pulmonary embolism is characterised by right ventricular dilatation. However, theoretically these characteristics might also be generated by asphyxia and the consequent hypoxia. We aimed to evaluate the ultrasonographic characteristics of asphyxia in a porcine model. Nineteen (13 intervention, 6 control) piglets were subjected to asphyxia until cardiac arrest, by disconnecting the ventilator tube. Ultrasonographic short-axis cine loops of the left ventricle were obtained every 30 seconds. The left ventricular (LV) eccentricity index (index of LV D-shaping) was quantified along with LV end-diastolic/end-systolic areas. Invasive pressures were measured throughout. The LV eccentricity index increased from 1.14 (1.10-1.31) to 1.86 (1.48-2.38), (P = 0.002), after 1.5 min, receded thereafter to baseline levels followed by a second increase after 5.5 min. LV end-diastolic area decreased from 11.6 cm(2) (11.1-13.2) to 6.3 cm(2) (3.3 -11.0) after 2.0 min (P = 0.009). Subsequently, values returned to the baseline level. The early and transient acute dilatation of the RV, coinciding with D-shaping of the LV and decrease in LV end-diastolic area seen in our study represent a combination of ultrasonographic characteristics normally attributed to pulmonary embolism. Early changes in ventricular chamber sizes and shape with septal flattening related to asphyxia can occur, but appear to be transient and disappear as circulatory collapse progresses, in an animal model. Despite this, asphyxia may represent a cause of ultrasonographic misinterpretation. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Effects of Prolonged Spaceflight on Atrial Size, Atrial Electrophysiology, and Risk of Atrial Fibrillation.

PubMed

Khine, Htet W; Steding-Ehrenborg, Katarina; Hastings, Jeffrey L; Kowal, Jamie; Daniels, James D; Page, Richard L; Goldberger, Jeffery J; Ng, Jason; Adams-Huet, Beverley; Bungo, Michael W; Levine, Benjamin D

2018-05-01

The prevalence of atrial fibrillation (AF) in active astronauts is ≈5%, similar to the general population but at a younger age. Risk factors for AF include left atrial enlargement, increased number of premature atrial complexes, and certain parameters on signal-averaged electrocardiography, such as P-wave duration, root mean square voltage for the terminal 20 ms of the signal-averaged P wave, and P-wave amplitude. We aimed to evaluate changes in atrial structure, supraventricular beats, and atrial electrophysiology to determine whether spaceflight could increase the risk of AF. Thirteen astronauts underwent cardiac magnetic resonance imaging to assess atrial structure and function before and after 6 months in space and high-resolution Holter monitoring for multiple 48-hour time periods before flight, during flight, and on landing day. Left atrial volume transiently increased after 6 months in space (12±18 mL; P =0.03) without changing atrial function. Right atrial size remained unchanged. No changes in supraventricular beats were noted. One astronaut had a large increase in supraventricular ectopic beats but none developed AF. Filtered P-wave duration did not change over time, but root mean square voltage for the terminal 20 ms decreased on all fight days except landing day. No changes in P-wave amplitude were seen in leads II or V 1 except landing day for lead V 1 . Six months of spaceflight may be sufficient to cause transient changes in left atrial structure and atrial electrophysiology that increase the risk of AF. However, there was no definite evidence of increased supraventricular arrhythmias and no identified episodes of AF. © 2018 American Heart Association, Inc.

Neuroprotective effects of ischemic preconditioning on hippocampal CA1 pyramidal neurons through maintaining calbindin D28k immunoreactivity following subsequent transient cerebral ischemia

PubMed Central

Kim, In Hye; Jeon, Yong Hwan; Lee, Tae-Kyeong; Cho, Jeong Hwi; Lee, Jae-Chul; Park, Joon Ha; Ahn, Ji Hyeon; Shin, Bich-Na; Kim, Yang Hee; Hong, Seongkweon; Yan, Bing Chun; Won, Moo-Ho; Lee, Yun Lyul

2017-01-01

Ischemic preconditioning elicited by a non-fatal brief occlusion of blood flow has been applied for an experimental therapeutic strategy against a subsequent fatal ischemic insult. In this study, we investigated the neuroprotective effects of ischemic preconditioning (2-minute transient cerebral ischemia) on calbindin D28k immunoreactivity in the gerbil hippocampal CA1 area following a subsequent fatal transient ischemic insult (5-minute transient cerebral ischemia). A large number of pyramidal neurons in the hippocampal CA1 area died 4 days after 5-minute transient cerebral ischemia. Ischemic preconditioning reduced the death of pyramidal neurons in the hippocampal CA1 area. Calbindin D28k immunoreactivity was greatly attenuated at 2 days after 5-minute transient cerebral ischemia and it was hardly detected at 5 days post-ischemia. Ischemic preconditioning maintained calbindin D28k immunoreactivity after transient cerebral ischemia. These findings suggest that ischemic preconditioning can attenuate transient cerebral ischemia-caused damage to the pyramidal neurons in the hippocampal CA1 area through maintaining calbindin D28k immunoreactivity. PMID:28761424

The Palomar Transient Factory: High Quality Realtime Data Processing in a Cost-Constrained Environment

NASA Astrophysics Data System (ADS)

Surace, J.; Laher, R.; Masci, F.; Grillmair, C.; Helou, G.

2015-09-01

The Palomar Transient Factory (PTF) is a synoptic sky survey in operation since 2009. PTF utilizes a 7.1 square degree camera on the Palomar 48-inch Schmidt telescope to survey the sky primarily at a single wavelength (R-band) at a rate of 1000-3000 square degrees a night. The data are used to detect and study transient and moving objects such as gamma ray bursts, supernovae and asteroids, as well as variable phenomena such as quasars and Galactic stars. The data processing system at IPAC handles realtime processing and detection of transients, solar system object processing, high photometric precision processing and light curve generation, and long-term archiving and curation. This was developed under an extremely limited budget profile in an unusually agile development environment. Here we discuss the mechanics of this system and our overall development approach. Although a significant scientific installation in of itself, PTF also serves as the prototype for our next generation project, the Zwicky Transient Facility (ZTF). Beginning operations in 2017, ZTF will feature a 50 square degree camera which will enable scanning of the entire northern visible sky every night. ZTF in turn will serve as a stepping stone to the Large Synoptic Survey Telescope (LSST), a major NSF facility scheduled to begin operations in the early 2020s.

LIMITS ON THE EVENT RATES OF FAST RADIO TRANSIENTS FROM THE V-FASTR EXPERIMENT

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

Wayth, Randall B.; Tingay, Steven J.; Deller, Adam T.

2012-07-10

We present the first results from the V-FASTR experiment, a commensal search for fast transient radio bursts using the Very Long Baseline Array (VLBA). V-FASTR is unique in that the widely spaced VLBA antennas provide a discriminant against non-astronomical signals and a mechanism for the localization and identification of events that is not possible with single dishes or short baseline interferometers. Thus, far V-FASTR has accumulated over 1300 hr of observation time with the VLBA, between 90 cm and 3 mm wavelength (327 MHz-86 GHz), providing the first limits on fast transient event rates at high radio frequencies (>1.4 GHz).more » V-FASTR has blindly detected bright individual pulses from seven known pulsars but has not detected any single-pulse events that would indicate high-redshift impulsive bursts of radio emission. At 1.4 GHz, V-FASTR puts limits on fast transient event rates comparable with the PALFA survey at the Arecibo telescope, but generally at lower sensitivities, and comparable to the 'fly's eye' survey at the Allen Telescope Array, but with less sky coverage. We also illustrate the likely performance of the Phase 1 SKA dish array for an incoherent fast transient search fashioned on V-FASTR.« less

A FRAMEWORK FOR INTERPRETING FAST RADIO TRANSIENTS SEARCH EXPERIMENTS: APPLICATION TO THE V-FASTR EXPERIMENT

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

Trott, Cathryn M.; Tingay, Steven J.; Wayth, Randall B.

2013-04-10

We define a framework for determining constraints on the detection rate of fast transient events from a population of underlying sources, with a view to incorporate beam shape, frequency effects, scattering effects, and detection efficiency into the metric. We then demonstrate a method for combining independent data sets into a single event rate constraint diagram, using a probabilistic approach to the limits on parameter space. We apply this new framework to present the latest results from the V-FASTR experiment, a commensal fast transients search using the Very Long Baseline Array (VLBA). In the 20 cm band, V-FASTR now has themore » ability to probe the regions of parameter space of importance for the observed Lorimer and Keane fast radio transient candidates by combining the information from observations with differing bandwidths, and properly accounting for the source dispersion measure, VLBA antenna beam shape, experiment time sampling, and stochastic nature of events. We then apply the framework to combine the results of the V-FASTR and Allen Telescope Array Fly's Eye experiments, demonstrating their complementarity. Expectations for fast transients experiments for the SKA Phase I dish array are then computed, and the impact of large differential bandwidths is discussed.« less

Automated Detection and Modeling of Slow Slip: Case Study of the Cascadia Subduction Zone

NASA Astrophysics Data System (ADS)

Crowell, B. W.; Bock, Y.; Liu, Z.

2012-12-01

The discovery of transient slow slip events over the past decade has changed our understanding of tectonic hazards and the earthquake cycle. Proper geodetic characterization of transient deformation is necessary for studies of regional interseismic, coseismic and postseismic tectonics, and miscalculations can affect our understanding of the regional stress field. We utilize two different methods to create a complete record of slow slip from continuous GPS stations in the Cascadia subduction zone between 1996 and 2012: spatiotemporal principal component analysis (PCA) and the relative strength index (RSI). The PCA is performed on 100 day windows of nearby stations to locate signals that exist across many stations in the network by looking at the ratio of the first two eigenvalues. The RSI is a financial momentum oscillator that looks for changes in individual time series with respect to previous epochs to locate rapid changes, indicative of transient deformation. Using both methods, we create a complete history of slow slip across the Cascadia subduction zone, fully characterizing the timing, progression, and magnitude of events. We inject the results from the automated transient detection into a time-dependent slip inversion and apply a Kalman filter based network inversion method to image the spatiotemporal variation of slip transients along the Cascadia margin.

Optical Timing of X-Ray Transient MAXI J1727-203 with ULTRACAM/NTT

NASA Astrophysics Data System (ADS)

Paice, J. A.; Gandhi, P.; Dhillon, V. S.; Marsh, T. R.; Buckley, D. A. H.; Kotze, M. M.; Altamirano, D.; Charles, P. A.

2018-06-01

MAXI J1727-203 is a new X-ray transient discovered on 5th June 2018 14:29 UT by MAXI (ATel #11683), with an optical counterpart detected by GROND (Atel #11690) and confirmed by the Hiltner telescope (ATel #11691), MASTER (ATel #11692) and Swift/UVOT (ATel #11697).

Advances in transient (pulsed) eddy current for inspection of multi-layer aluminum structures in the presence of ferrous fasteners

NASA Astrophysics Data System (ADS)

Desjardins, D. R.; Vallières, G.; Whalen, P. P.; Krause, T. W.

2012-05-01

An experimental investigation of the electromagnetic processes underlying transient (pulsed) eddy current inspection of aircraft wing structures in the vicinity of ferrous fasteners is performed. The separate effects of transient excitation of ferrous fastener and eddy currents induced in the surrounding aluminum structure are explored using a transmit-receive configuration with transient excitation of a steel rod, an aluminum plate with a bore hole and a steel rod through the bore hole. Observations are used to interpret results from a coupled driving and differential coil sensing unit applied to detect fatigue cracks emanating from bolt holes in aluminum structures with ferrous fasteners present. In particular, it is noted that abrupt magnetization of the fastener, by the probe's central driving unit, can transfer flux and consequently, induce strong eddy current responses deep within the aluminum structure in the vicinity of the bore hole. Rotation of the probe, centered over the fastener, permits detection of subsurface discontinuities, such as cracks, by the pair of differentially connected pickup coils.

Accurate computer-aided quantification of left ventricular parameters: experience in 1555 cardiac magnetic resonance studies from the Framingham Heart Study.

PubMed

Hautvast, Gilion L T F; Salton, Carol J; Chuang, Michael L; Breeuwer, Marcel; O'Donnell, Christopher J; Manning, Warren J

2012-05-01

Quantitative analysis of short-axis functional cardiac magnetic resonance images can be performed using automatic contour detection methods. The resulting myocardial contours must be reviewed and possibly corrected, which can be time-consuming, particularly when performed across all cardiac phases. We quantified the impact of manual contour corrections on both analysis time and quantitative measurements obtained from left ventricular short-axis cine images acquired from 1555 participants of the Framingham Heart Study Offspring cohort using computer-aided contour detection methods. The total analysis time for a single case was 7.6 ± 1.7 min for an average of 221 ± 36 myocardial contours per participant. This included 4.8 ± 1.6 min for manual contour correction of 2% of all automatically detected endocardial contours and 8% of all automatically detected epicardial contours. However, the impact of these corrections on global left ventricular parameters was limited, introducing differences of 0.4 ± 4.1 mL for end-diastolic volume, -0.3 ± 2.9 mL for end-systolic volume, 0.7 ± 3.1 mL for stroke volume, and 0.3 ± 1.8% for ejection fraction. We conclude that left ventricular functional parameters can be obtained under 5 min from short-axis functional cardiac magnetic resonance images using automatic contour detection methods. Manual correction more than doubles analysis time, with minimal impact on left ventricular volumes and ejection fraction. Copyright © 2011 Wiley Periodicals, Inc.

Small Near-Earth Asteroids in the Palomar Transient Factory Survey: A Real-Time Streak-detection System

NASA Astrophysics Data System (ADS)

Waszczak, Adam; Prince, Thomas A.; Laher, Russ; Masci, Frank; Bue, Brian; Rebbapragada, Umaa; Barlow, Tom; Surace, Jason; Helou, George; Kulkarni, Shrinivas

2017-03-01

Near-Earth asteroids (NEAs) in the 1-100 meter size range are estimated to be ˜1,000 times more numerous than the ˜15,000 currently cataloged NEAs, most of which are in the 0.5-10 kilometer size range. Impacts from 10-100 meter size NEAs are not statistically life-threatening, but may cause significant regional damage, while 1-10 meter size NEAs with low velocities relative to Earth are compelling targets for space missions. We describe the implementation and initial results of a real-time NEA-discovery system specialized for the detection of small, high angular rate (visually streaked) NEAs in Palomar Transient Factory (PTF) images. PTF is a 1.2-m aperture, 7.3 deg2 field of view (FOV) optical survey designed primarily for the discovery of extragalactic transients (e.g., supernovae) in 60-second exposures reaching ˜20.5 visual magnitude. Our real-time NEA discovery pipeline uses a machine-learned classifier to filter a large number of false-positive streak detections, permitting a human scanner to efficiently and remotely identify real asteroid streaks during the night. Upon recognition of a streaked NEA detection (typically within an hour of the discovery exposure), the scanner triggers follow-up with the same telescope and posts the observations to the Minor Planet Center for worldwide confirmation. We describe our 11 initial confirmed discoveries, all small NEAs that passed 0.3-15 lunar distances from Earth. Lastly, we derive useful scaling laws for comparing streaked-NEA-detection capabilities of different surveys as a function of their hardware and survey-pattern characteristics. This work most directly informs estimates of the streak-detection capabilities of the Zwicky Transient Facility (ZTF, planned to succeed PTF in 2017), which will apply PTF’s current resolution and sensitivity over a 47-deg2 FOV.

Method for detecting moment connection fracture using high-frequency transients in recorded accelerations

USGS Publications Warehouse

Rodgers, J.E.; Elebi, M.

2011-01-01

The 1994 Northridge earthquake caused brittle fractures in steel moment frame building connections, despite causing little visible building damage in most cases. Future strong earthquakes are likely to cause similar damage to the many un-retrofitted pre-Northridge buildings in the western US and elsewhere. Without obvious permanent building deformation, costly intrusive inspections are currently the only way to determine if major fracture damage that compromises building safety has occurred. Building instrumentation has the potential to provide engineers and owners with timely information on fracture occurrence. Structural dynamics theory predicts and scale model experiments have demonstrated that sudden, large changes in structure properties caused by moment connection fractures will cause transient dynamic response. A method is proposed for detecting the building-wide level of connection fracture damage, based on observing high-frequency, fracture-induced transient dynamic responses in strong motion accelerograms. High-frequency transients are short (<1 s), sudden-onset waveforms with frequency content above 25 Hz that are visually apparent in recorded accelerations. Strong motion data and damage information from intrusive inspections collected from 24 sparsely instrumented buildings following the 1994 Northridge earthquake are used to evaluate the proposed method. The method's overall success rate for this data set is 67%, but this rate varies significantly with damage level. The method performs reasonably well in detecting significant fracture damage and in identifying cases with no damage, but fails in cases with few fractures. Combining the method with other damage indicators and removing records with excessive noise improves the ability to detect the level of damage. ?? 2010 Elsevier B.V. All rights reserved.

Detection of phasic dopamine by D1 and D2 striatal medium spiny neurons.

PubMed

Yapo, Cedric; Nair, Anu G; Clement, Lorna; Castro, Liliana R; Hellgren Kotaleski, Jeanette; Vincent, Pierre

2017-12-15

Brief dopamine events are critical actors of reward-mediated learning in the striatum; the intracellular cAMP-protein kinase A (PKA) response of striatal medium spiny neurons to such events was studied dynamically using a combination of biosensor imaging in mouse brain slices and in silico simulations. Both D1 and D2 medium spiny neurons can sense brief dopamine transients in the sub-micromolar range. While dopamine transients profoundly change cAMP levels in both types of medium spiny neurons, the PKA-dependent phosphorylation level remains unaffected in D2 neurons. At the level of PKA-dependent phosphorylation, D2 unresponsiveness depends on protein phosphatase-1 (PP1) inhibition by DARPP-32. Simulations suggest that D2 medium spiny neurons could detect transient dips in dopamine level. The phasic release of dopamine in the striatum determines various aspects of reward and action selection, but the dynamics of the dopamine effect on intracellular signalling remains poorly understood. We used genetically encoded FRET biosensors in striatal brain slices to quantify the effect of transient dopamine on cAMP or PKA-dependent phosphorylation levels, and computational modelling to further explore the dynamics of this signalling pathway. Medium-sized spiny neurons (MSNs), which express either D 1 or D 2 dopamine receptors, responded to dopamine by an increase or a decrease in cAMP, respectively. Transient dopamine showed similar sub-micromolar efficacies on cAMP in both D1 and D2 MSNs, thus challenging the commonly accepted notion that dopamine efficacy is much higher on D 2 than on D 1 receptors. However, in D2 MSNs, the large decrease in cAMP level triggered by transient dopamine did not translate to a decrease in PKA-dependent phosphorylation level, owing to the efficient inhibition of protein phosphatase 1 by DARPP-32. Simulations further suggested that D2 MSNs can also operate in a 'tone-sensing' mode, allowing them to detect transient dips in basal dopamine. Overall, our results show that D2 MSNs may sense much more complex patterns of dopamine than previously thought. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Left cytoarchitectonic BA 44 processes syntactic gender violations in determiner phrases.

PubMed

Heim, Stefan; van Ermingen, Muna; Huber, Walter; Amunts, Katrin

2010-10-01

Recent neuroimaging studies make contradictory predictions about the involvement of left Brodmann's area (BA) 44 in processing local syntactic violations in determiner phrases (DPs). Some studies suggest a role for BA 44 in detecting local syntactic violations, whereas others attribute this function to the left premotor cortex. Therefore, the present event-related functional magnetic resonance imaging (fMRI) study investigated whether left-cytoarchitectonic BA 44 was activated when German DPs involving syntactic gender violations were compared with correct DPs (correct: 'der Baum'-the[masculine] tree[masculine]; violated: 'das Baum'--the[neuter] tree[masculine]). Grammaticality judgements were made for both visual and auditory DPs to be able to generalize the results across modalities. Grammaticality judgements involved, among others, left BA 44 and left BA 6 in the premotor cortex for visual and auditory stimuli. Most importantly, activation in left BA 44 was consistently higher for violated than for correct DPs. This finding was behaviourally corroborated by longer reaction times for violated versus correct DPs. Additional brain regions, showing the same effect, included left premotor cortex, supplementary motor area, right middle and superior frontal cortex, and left cerebellum. Based on earlier findings from the literature, the results indicate the involvement of left BA 44 in processing local syntactic violations when these include morphological features, whereas left premotor cortex seems crucial for the detection of local word category violations. © 2010 Wiley-Liss, Inc.

Normalizing effect of heroin maintenance treatment on stress-induced brain connectivity

PubMed Central

Walter, Marc; Gerber, Hana; Seifritz, Erich; Brenneisen, Rudolf; Wiesbeck, Gerhard A.; Riecher-Rössler, Anita; Lang, Undine E.; Borgwardt, Stefan

2015-01-01

Recent evidence has shown that a single maintenance dose of heroin attenuates psychophysiological stress responses in heroin-dependent patients, probably reflecting the effectiveness of heroin-assisted therapies for the treatment of severe heroin addiction. However, the underlying neural circuitry of these effects has not yet been investigated. Using a cross-over, double-blind, vehicle-controlled design, 22 heroin-dependent and heroin-maintained outpatients from the Centre of Substance Use Disorders at the University Hospital of Psychiatry in Basel were studied after heroin and placebo administration, while 17 healthy controls from the general population were included for placebo administration only. Functional magnetic resonance imaging was used to detect brain responses to fearful faces and dynamic causal modelling was applied to compute fear-induced modulation of connectivity within the emotional face network. Stress responses were assessed by hormone releases and subjective ratings. Relative to placebo, heroin acutely reduced the fear-induced modulation of connectivity from the left fusiform gyrus to the left amygdala and from the right amygdala to the right orbitofrontal cortex in dependent patients. Both of these amygdala-related connectivity strengths were significantly increased in patients after placebo treatment (acute withdrawal) compared to healthy controls, whose connectivity estimates did not differ from those of patients after heroin injection. Moreover, we found positive correlations between the left fusiform gyrus to amygdala connectivity and different stress responses, as well as between the right amygdala to orbitofrontal cortex connectivity and levels of craving. Our findings indicate that the increased amygdala-related connectivity during fearful face processing after the placebo treatment in heroin-dependent patients transiently normalizes after acute heroin maintenance treatment. Furthermore, this study suggests that the assessment of amygdala-related connectivity during fear processing may provide a prognostic tool to assess stress levels in heroin-dependent patients and to quantify the efficacy of maintenance treatments in drug addiction. PMID:25414039

Study on the Relationships between Intrinsic Functional Connectivity of the Default Mode Network and Transient Epileptic Activity

PubMed Central

Lopes, Renaud; Moeller, Friederike; Besson, Pierre; Ogez, François; Szurhaj, William; Leclerc, Xavier; Siniatchkin, Michael; Chipaux, Mathilde; Derambure, Philippe; Tyvaert, Louise

2014-01-01

Rationale: Simultaneous recording of electroencephalogram and functional MRI (EEG–fMRI) is a powerful tool for localizing epileptic networks via the detection of hemodynamic changes correlated with interictal epileptic discharges (IEDs). fMRI can be used to study the long-lasting effect of epileptic activity by assessing stationary functional connectivity during the resting-state period [especially, the connectivity of the default mode network (DMN)]. Temporal lobe epilepsy (TLE) and idiopathic generalized epilepsy (IGE) are associated with low responsiveness and disruption of DMN activity. A dynamic functional connectivity approach might enable us to determine the effect of IEDs on DMN connectivity and to better understand the correlation between DMN connectivity changes and altered consciousness. Method: We studied dynamic changes in DMN intrinsic connectivity and their relation to IEDs. Six IGE patients (with generalized spike and slow-waves) and 6 TLE patients (with unilateral left temporal spikes) were included. Functional connectivity before, during, and after IEDs was estimated using a sliding window approach and compared with the baseline period. Results: No dependence on window size was observed. The baseline DMN connectivity was decreased in the left hemisphere (ipsilateral to the epileptic focus) in TLEs and was less strong but remained bilateral in IGEs. We observed an overall increase in DMN intrinsic connectivity prior to the onset of IEDs in both IGEs and TLEs. After IEDs in TLEs, we found that DMN connectivity increased before it returned to baseline values. Most of the DMN regions with increased connectivity before and after IEDs were lateralized to the left hemisphere in TLE (i.e., ipsilateral to the epileptic focus). Conclusion: Results suggest that DMN connectivity may facilitate IED generation and may be affected at the time of the IED. However, these results need to be confirmed in a larger independent cohort. PMID:25346721

[A unique case of secondary takotsubo syndrome].

PubMed

Arcari, Luca; Limite, Luca Rosario; Autore, Camillo; Volpe, Massimo; Musumeci, Maria Beatrice

2018-04-01

Takotsubo syndrome (TTS) is an acute cardiac syndrome characterized by transient systolic left ventricular dysfunction frequently preceded by stressful events. It typically affects postmenopausal women without angiographic evidence of obstructive coronary artery disease. We report here an uncommon occurrence of secondary TTS in a male with coronary artery disease after exogenous catecholamine administration and pacemaker implantation. This unexpected case suggests that, in such clinical scenario, a TTS diagnosis might be considered even in unsuspected individuals.

Beauty parlor stroke syndrome due to a bone fragment from an osteophyte of the atlas: case report.

PubMed

Kameda, Takuya; Otani, Koji; Tamura, Takamitsu; Konno, Shinichi

2018-04-01

Beauty parlor stroke syndrome (BPSS) is a rare condition characterized by mechanical impingement of a vertebral artery (VA) during neck rotation and/or hyperextension followed by vertebrobasilar insufficiency. However, there have been no reports of BPSS in which the cause of mechanical impingement was identified and no cases for which surgical treatment was reported. The authors report the case of a 56-year-old Japanese man who presented with presyncope that occurred during cervical extension. Given the possibility of vertebrobasilar insufficiency, digital subtraction angiography and CT angiography were performed. These studies revealed that the right VA was hypoplastic and the left VA was dominant. Moreover, in the position of cervical extension, the dominant left VA showed constriction caused by a bone fragment of an osteophyte of the atlas. Removal of the bone fragment was performed. Postoperative left vertebral angiography showed improvement of blood flow in the extended position, and the presyncope completely disappeared. The pathomechanism of this case was a bone fragment compressing the left VA in the C-1 groove during neck extension. In BPSS patients with recurrent transient symptoms, the possibility of this mechanism of VA constriction by a free bone fragment should be considered.

A very rare venous anomaly in a living liver donor: left hepatic venous connection to the right atrium.

PubMed

Uraz, S; Duran, C; Balci, D; Akin, B; Dayangac, M; Kurt, Z; Ayanoglu, O H; Killi, R; Yuzer, Y; Tokat, Y

2007-06-01

In humans, three main hepatic veins drain the liver into the inferior vena cava below the diaphragm. This report represents the first living donor liver that had a rare anatomic variation of the left hepatic vein draining directly to the right atrium, which was detected preoperatively by routine investigations of the living donor transplantation. This type of anomaly may present potentially fatal challenges to a donor operation if not detected preoperatively, especially when the left lobe is the choice for explantation.

Functional difference between sustained and transient modulations of cognitive control in the simon task: evidence from false alarm responses on no-go trials.

PubMed

Hasegawa, Kunihiro; Takahashi, Shin'ya

2013-01-01

Cognitive control in response compatibility tasks is modulated by the task context. Two types of contextual modulations have been demonstrated; sustained (block-wise) and transient (trial-by-trial). Recent research suggests that these modulations have different underlying mechanisms. This study presents new evidence supporting this claim by comparing false alarm (FA) responses on no-go trials of the Simon task between the sustained and transient contexts. In Experiment 1, the sustained context was manipulated so that a block included a larger number of incongruent trials. Results showed that participants made more FA responses by the hand opposite to the stimulus location. This suggests a generation of response bias in which the task-irrelevant location information is utilized in a reversed manner (i.e., to respond with the right hand to a stimulus presented on the left side and vice versa). Next, Experiment 2 examined the effect of the transient context and found that overall FA rate was lower when a no-go trial was preceded by an incongruent trial than by a congruent trial, whereas such response bias as that shown in Experiment 1 was not demonstrated. This suggests that the transient conflict context enhances inhibition of the task-irrelevant process but does not make the task-irrelevant information actively usable. Based on these results, we propound two types of cognitive control modulations as adaptive behaviors: response biasing based on utilization of the task-irrelevant information under the sustained conflict context and transient enhancement of inhibition of the task-irrelevant process based on the online conflict monitoring.

Liverpool telescope 2: a new robotic facility for rapid transient follow-up

NASA Astrophysics Data System (ADS)

Copperwheat, C. M.; Steele, I. A.; Barnsley, R. M.; Bates, S. D.; Bersier, D.; Bode, M. F.; Carter, D.; Clay, N. R.; Collins, C. A.; Darnley, M. J.; Davis, C. J.; Gutierrez, C. M.; Harman, D. J.; James, P. A.; Knapen, J. H.; Kobayashi, S.; Marchant, J. M.; Mazzali, P. A.; Mottram, C. J.; Mundell, C. G.; Newsam, A.; Oscoz, A.; Palle, E.; Piascik, A.; Rebolo, R.; Smith, R. J.

2015-03-01

The Liverpool Telescope is one of the world's premier facilities for time domain astronomy. The time domain landscape is set to radically change in the coming decade, with synoptic all-sky surveys such as LSST providing huge numbers of transient detections on a nightly basis; transient detections across the electromagnetic spectrum from other major facilities such as SVOM, SKA and CTA; and the era of `multi-messenger astronomy', wherein astrophysical events are detected via non-electromagnetic means, such as neutrino or gravitational wave emission. We describe here our plans for the Liverpool Telescope 2: a new robotic telescope designed to capitalise on this new era of time domain astronomy. LT2 will be a 4-metre class facility co-located with the Liverpool Telescope at the Observatorio del Roque de Los Muchachos on the Canary island of La Palma. The telescope will be designed for extremely rapid response: the aim is that the telescope will take data within 30 seconds of the receipt of a trigger from another facility. The motivation for this is twofold: firstly it will make it a world-leading facility for the study of fast fading transients and explosive phenomena discovered at early times. Secondly, it will enable large-scale programmes of low-to-intermediate resolution spectral classification of transients to be performed with great efficiency. In the target-rich environment of the LSST era, minimising acquisition overheads will be key to maximising the science gains from any follow-up programme. The telescope will have a diverse instrument suite which is simultaneously mounted for automatic changes, but it is envisaged that the primary instrument will be an intermediate resolution, optical/infrared spectrograph for scientific exploitation of transients discovered with the next generation of synoptic survey facilities. In this paper we outline the core science drivers for the telescope, and the requirements for the optical and mechanical design.

Event-related cerebral hemodynamics reveal target-specific resource allocation for both "go" and "no-go" response-based vigilance tasks.

PubMed

Shaw, Tyler H; Funke, Matthew E; Dillard, Michael; Funke, Gregory J; Warm, Joel S; Parasuraman, Raja

2013-08-01

Transcranial Doppler sonography was used to measure cerebral blood flow velocity (CBFV) in the right and left cerebral hemispheres during the performance of a 50-min visual vigilance session. Observers monitored a simulated flight of unmanned aerial vehicles for cases in which one of the vehicles was flying in an inappropriate direction relative to its cohorts. Two types of vigilance tasks were employed: a traditional task in which observers made button press ("go") responses to critical signals, and a modification of the traditional task called the Sustained Attention to Response Task (SART) in which "go" responses acknowledged nonsignal events and response withholding ("no-go") signified signal detection. Signal detections and global CBFV scores declined over time. In addition, fine-grained event-related analyses revealed that the detection of signals was accompanied by an elevation of CBFV that was not present with missed signals. As was the case with the global scores, the magnitude of the transient CBFV increments associated with signal detection also declined over time, and these findings were independent of task type. The results support the view of CBFV as an index of the cognitive evaluation of stimulus significance, and a resource model of vigilance in which the need for continuous attention produces a depletion of information-processing assets that are not replenished as the task progresses. Further, temporal declines in the magnitude of event-related CBFV in response to critical signals only is evidence that the decrement function in vigilance is due to attentional processing and not specific task elements such as the required response format. Copyright © 2013. Published by Elsevier Inc.

Limits on radio emission from meteors using the MWA

NASA Astrophysics Data System (ADS)

Zhang, X.; Hancock, P.; Devillepoix, H. A. R.; Wayth, R. B.; Beardsley, A.; Crosse, B.; Emrich, D.; Franzen, T. M. O.; Gaensler, B. M.; Horsley, L.; Johnston-Hollitt, M.; Kaplan, D. L.; Kenney, D.; Morales, M. F.; Pallot, D.; Steele, K.; Tingay, S. J.; Trott, C. M.; Walker, M.; Williams, A.; Wu, C.; Ji, Jianghui; Ma, Yuehua

2018-07-01

Recently, low-frequency, broad-band radio emission has been observed accompanying bright meteors by the Long Wavelength Array (LWA). The broad-band spectra between 20 and 60 MHz were captured for several events, while the spectral index (dependence of flux density on frequency, with Sν ∝ να) was estimated to be -4 ± 1 during the peak of meteor afterglows. Here we present a survey of meteor emission and other transient events using the Murchison Wide Field Array (MWA) at 72-103 MHz. In our 322 h survey, down to a 5σ detection threshold of 3.5 Jy beam-1, no transient candidates were identified as intrinsic emission from meteors. We derived an upper limit of -3.7 (95 per cent confidence limit) on the spectral index in our frequency range. We also report detections of other transient events, such as reflected FM broadcast signals from small satellites, conclusively demonstrating the ability of the MWA to detect and track space debris on scales as small as 0.1 m in low Earth orbits.

A Novel Transient Fault Current Sensor Based on the PCB Rogowski Coil for Overhead Transmission Lines

PubMed Central

Liu, Yadong; Xie, Xiaolei; Hu, Yue; Qian, Yong; Sheng, Gehao; Jiang, Xiuchen

2016-01-01

The accurate detection of high-frequency transient fault currents in overhead transmission lines is the basis of malfunction detection and diagnosis. This paper proposes a novel differential winding printed circuit board (PCB) Rogowski coil for the detection of transient fault currents in overhead transmission lines. The interference mechanism of the sensor surrounding the overhead transmission line is analyzed and the guideline for the interference elimination is obtained, and then a differential winding printed circuit board (PCB) Rogowski coil is proposed, where the branch and return line of the PCB coil were designed to be strictly symmetrical by using a joining structure of two semi-rings and collinear twisted pair differential windings in each semi-ring. A serial test is conducted, including the frequency response, linearity, and anti-interference performance as well as a comparison with commercial sensors. Results show that a PCB Rogowski coil has good linearity and resistance to various external magnetic field interferences, thus enabling it to be widely applied in fault-current-collecting devices. PMID:27213402

Extreme Ultraviolet Explorer observations of the magnetic cataclysmic variable RE 1938-461

NASA Technical Reports Server (NTRS)

Warren, John K.; Vallerga, John V.; Mauche, Christopher W.; Mukai, Koji; Siegmund, Oswald H. W.

1993-01-01

The magnetic cataclysmic variable RE 1938-461 was observed by the Extreme Ultraviolet Explorer (EUVE) Deep Survey instrument on 1992 July 8-9 during in-orbit calibration. It was detected in the Lexan/ boron (65-190 A) band, with a quiescent count rate of 0.0062 +/- 0.0017/s, and was not detected in the aluminum/carbon (160-360 A) band. The Lexan/boron count rate is lower than the corresponding ROSAT wide-field camera Lexan/boron count rate. This is consistent with the fact that the source was in a low state during an optical observation performed just after the EUVE observation, whereas it was in an optical high state during the ROSAT observation. The quiescent count rates are consistent with a virtual cessation of accretion. Two transient events lasting about 1 hr occurred during the Lexan/boron pointing, the second at a count rate of 0.050 +/- 0.006/s. This appears to be the first detection of an EUV transient during the low state of a magnetic cataclysmic variable. We propose two possible explanations for the transient events.

Asymmetric top-down modulation of ascending visual pathways in pigeons.

PubMed

Freund, Nadja; Valencia-Alfonso, Carlos E; Kirsch, Janina; Brodmann, Katja; Manns, Martina; Güntürkün, Onur

2016-03-01

Cerebral asymmetries are a ubiquitous phenomenon evident in many species, incl. humans, and they display some similarities in their organization across vertebrates. In many species the left hemisphere is associated with the ability to categorize objects based on abstract or experience-based behaviors. Using the asymmetrically organized visual system of pigeons as an animal model, we show that descending forebrain pathways asymmetrically modulate visually evoked responses of single thalamic units. Activity patterns of neurons within the nucleus rotundus, the largest thalamic visual relay structure in birds, were differently modulated by left and right hemispheric descending systems. Thus, visual information ascending towards the left hemisphere was modulated by forebrain top-down systems at thalamic level, while right thalamic units were strikingly less modulated. This asymmetry of top-down control could promote experience-based processes within the left hemisphere, while biasing the right side towards stimulus-bound response patterns. In a subsequent behavioral task we tested the possible functional impact of this asymmetry. Under monocular conditions, pigeons learned to discriminate color pairs, so that each hemisphere was trained on one specific discrimination. Afterwards the animals were presented with stimuli that put the hemispheres in conflict. Response patterns on the conflicting stimuli revealed a clear dominance of the left hemisphere. Transient inactivation of left hemispheric top-down control reduced this dominance while inactivation of right hemispheric top-down control had no effect on response patterns. Functional asymmetries of descending systems that modify visual ascending pathways seem to play an important role in the superiority of the left hemisphere in experience-based visual tasks. Copyright © 2015. Published by Elsevier Ltd.

Representation of Semantic Similarity in the Left Intraparietal Sulcus: Functional Magnetic Resonance Imaging Evidence

PubMed Central

Neyens, Veerle; Bruffaerts, Rose; Liuzzi, Antonietta G.; Kalfas, Ioannis; Peeters, Ronald; Keuleers, Emmanuel; Vogels, Rufin; De Deyne, Simon; Storms, Gert; Dupont, Patrick; Vandenberghe, Rik

2017-01-01

According to a recent study, semantic similarity between concrete entities correlates with the similarity of activity patterns in left middle IPS during category naming. We examined the replicability of this effect under passive viewing conditions, the potential role of visuoperceptual similarity, where the effect is situated compared to regions that have been previously implicated in visuospatial attention, and how it compares to effects of object identity and location. Forty-six subjects participated. Subjects passively viewed pictures from two categories, musical instruments and vehicles. Semantic similarity between entities was estimated based on a concept-feature matrix obtained in more than 1,000 subjects. Visuoperceptual similarity was modeled based on the HMAX model, the AlexNet deep convolutional learning model, and thirdly, based on subjective visuoperceptual similarity ratings. Among the IPS regions examined, only left middle IPS showed a semantic similarity effect. The effect was significant in hIP1, hIP2, and hIP3. Visuoperceptual similarity did not correlate with similarity of activity patterns in left middle IPS. The semantic similarity effect in left middle IPS was significantly stronger than in the right middle IPS and also stronger than in the left or right posterior IPS. The semantic similarity effect was similar to that seen in the angular gyrus. Object identity effects were much more widespread across nearly all parietal areas examined. Location effects were relatively specific for posterior IPS and area 7 bilaterally. To conclude, the current findings replicate the semantic similarity effect in left middle IPS under passive viewing conditions, and demonstrate its anatomical specificity within a cytoarchitectonic reference frame. We propose that the semantic similarity effect in left middle IPS reflects the transient uploading of semantic representations in working memory. PMID:28824405

Investigations into the Early Life History of Naturally Produced Spring Chinook Salmon in the Grande Ronde River Basin : Fish Research Project Oregon : Annual Progress Report Project Period 1 September 1998 to 31 August 1999.

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

Jonasson, Brian C.

2000-01-01

We determined migration timing and abundance of juvenile spring chinook salmon from three populations in the Grande Ronde River basin. We estimated 13,180 juvenile chinook salmon left upper rearing areas of the Grande Ronde River from July 1998 to June 1999; approximately 0.2% of the migrants left in summer, 18% in fall and 82% in spring. We estimated 15,949 juvenile chinook salmon left upper rearing areas of Catherine Creek from July 1998 to June 1999; approximately 0.2% of the migrants left in summer, 57% in fall, 2% in winter, and 41% in spring. We estimated 14,537 juvenile chinook salmon leftmore » the Grande Ronde Valley, located below the upper rearing areas in Catherine Creek and the Grande Ronde River, from October 1998 to June 1999; approximately 99% of the migrants left in spring. We estimated 31,113 juvenile chinook salmon left upper rearing areas of the Lostine River from July 1998 to June 1999; approximately 4% of the migrants left in summer, 57% in fall, 3% in winter, and 36% in spring. We estimated 42,705 juvenile spring chinook salmon left the Wallowa Valley, located below the mouth of the Lostine River, from August 1998 to June 1999; approximately 46% of the migrants left in fall, 6% in winter, and 47% in spring. Juvenile chinook salmon PIT-tagged on the upper Grande Ronde River were detected at Lower Granite Dam from 31 March to 20 June 1999, with a median passage date of 5 May. PIT-tagged salmon from Catherine Creek were detected at Lower Granite Dam from 19 April to 9 July 1999, with a median passage date of 24 May. PIT-tagged salmon from the Lostine River were detected at Lower Granite Dam from 31 March through 8 July 1999, with a median passage date of 4 May. Juveniles tagged as they left the upper rearing areas of the Grande Ronde River in fall and that overwintered in areas downstream were detected in the hydrosystem at a higher rate than fish tagged during winter in the upper rearing areas, indicating a higher overwinter survival in the downstream areas. Juveniles tagged as they left the upper rearing areas of Catherine Creek in fall and that overwintered in areas downstream were detected in the hydrosystem at a lower rate than fish tagged during winter in the upper rearing areas, indicating a higher overwinter survival in the upper rearing areas. Juveniles tagged as they left the upper rearing areas of the Lostine River in fall and that overwintered in areas downstream were detected in the hydrosystem at a similar rate to fish tagged during winter in the upper rearing areas, indicating similar overwinter survival in the upstream and downstream areas. Chinook salmon parr were generally associated with low velocity habitat types, that is pools, during both winter and summer in the Lostine River.« less

Detection of Microcracks in Trunnion Rods Using Ultrasonic Guided Waves

DTIC Science & Technology

2015-07-01

49 Figure 40. Larger second echo from PMN-PT vs. PZT transducer. ........................................................ 50...Figure. 41 Nonlinear crack simulations: two polished ends pulled together (top left), fatigued aluminum (bottom left), nut coupled and shims hammered... fatigued rods, can go through opening and closing variations during their deterioration. Microcracked rods need to be detected and quantified

The Right Hemisphere Advantage in Visual Change Detection Depends on Temporal Factors

ERIC Educational Resources Information Center

Spotorno, Sara; Faure, Sylvane

2011-01-01

What accounts for the Right Hemisphere (RH) functional superiority in visual change detection? An original task which combines one-shot and divided visual field paradigms allowed us to direct change information initially to the RH or the Left Hemisphere (LH) by deleting, respectively, an object included in the left or right half of a scene…

Effect of ischemic preconditioning on antioxidant status in the gerbil hippocampal CA1 region after transient forebrain ischemia

PubMed Central

Park, Seung Min; Park, Chan Woo; Lee, Tae-Kyeong; Cho, Jeong Hwi; Park, Joon Ha; Lee, Jae-Chul; Chen, Bai Hui; Shin, Bich-Na; Ahn, Ji Hyeon; Tae, Hyun-Jin; Shin, Myoung Cheol; Ohk, Taek Geun; Cho, Jun Hwi; Won, Moo-Ho; Choi, Soo Young; Kim, In Hye

2016-01-01

Ischemic preconditioning (IPC) is a condition of sublethal transient global ischemia and exhibits neuroprotective effects against subsequent lethal ischemic insult. We, in this study, examined the neuroprotective effects of IPC and its effects on immunoreactive changes of antioxidant enzymes including superoxide dismutase (SOD) 1 and SOD2, catalase (CAT) and glutathione peroxidase (GPX) in the gerbil hippocampal CA1 region after transient forebrain ischemia. Pyramidal neurons of the stratum pyramidale (SP) in the hippocampal CA1 region of animals died 5 days after lethal transient ischemia without IPC (8.6% (ratio of remanent neurons) of the sham-operated group); however, IPC prevented the pyramidal neurons from subsequent lethal ischemic injury (92.3% (ratio of remanent neurons) of the sham-operated group). SOD1, SOD2, CAT and GPX immunoreactivities in the sham-operated animals were easily detected in pyramidal neurons in the stratum pyramidale (SP) of the hippocampal CA1 region, while all of these immunoreactivities were rarely detected in the stratum pyramidale at 5 days after lethal transient ischemia without IPC. Meanwhile, their immunoreactivities in the sham-operated animals with IPC were similar to (SOD1, SOD2 and CAT) or higher (GPX) than those in the sham-operated animals without IPC. Furthermore, their immunoreactivities in the stratum pyramidale of the ischemia-operated animals with IPC were steadily maintained after lethal ischemia/reperfusion. Results of western blot analysis for SOD1, SOD2, CAT and GPX were similar to immunohistochemical data. In conclusion, IPC maintained or increased the expression of antioxidant enzymes in the stratum pyramidale of the hippocampal CA1 region after subsequent lethal transient forebrain ischemia and IPC exhibited neuroprotective effects in the hippocampal CA1 region against transient forebrain ischemia. PMID:27630689

Transient Volcano Deformation Event Detection over Variable Spatial Scales in Alaska

NASA Astrophysics Data System (ADS)

Li, J. D.; Rude, C. M.; Gowanlock, M.; Herring, T.; Pankratius, V.

2016-12-01

Transient deformation events driven by volcanic activity can be monitored using increasingly dense networks of continuous Global Positioning System (GPS) ground stations. The wide spatial extent of GPS networks, the large number of GPS stations, and the spatially and temporally varying scale of deformation events result in the mixing of signals from multiple sources. Typical analysis then necessitates manual identification of times and regions of volcanic activity for further study and the careful tuning of algorithmic parameters to extract possible transient events. Here we present a computer-aided discovery system that facilitates the discovery of potential transient deformation events at volcanoes by providing a framework for selecting varying spatial regions of interest and for tuning the analysis parameters. This site specification step in the framework reduces the spatial mixing of signals from different volcanic sources before applying filters to remove interfering signals originating from other geophysical processes. We analyze GPS data recorded by the Plate Boundary Observatory network and volcanic activity logs from the Alaska Volcano Observatory to search for and characterize transient inflation events in Alaska. We find 3 transient inflation events between 2008 and 2015 at the Akutan, Westdahl, and Shishaldin volcanoes in the Aleutian Islands. The inflation event detected in the first half of 2008 at Akutan is validated other studies, while the inflation events observed in early 2011 at Westdahl and in early 2013 at Shishaldin are previously unreported. Our analysis framework also incorporates modelling of the transient inflation events and enables a comparison of different magma chamber inversion models. Here, we also estimate the magma sources that best describe the deformation observed by the GPS stations at Akutan, Westdahl, and Shishaldin. We acknowledge support from NASA AIST-NNX15AG84G (PI: V. Pankratius).

Brief hypo-osmotic shock causes test cell death, prevents neurula rotation, and disrupts left-right asymmetry in Ciona intestinalis.

PubMed

Katsumoto, Shimpei; Hatta, Kohei; Nakagawa, Masashi

2013-05-01

Ascidian Ciona intestinalis tadpole larvae exhibit left-right asymmetry. The photoreceptors are situated on the right side of the sensory vesicle, and the tail curls along the left side of the trunk within the chorion. In tailbud embryos, the Ci-pitx gene is expressed in the left-side epidermis. It was previously reported that embryos generated from naked eggs, which lack the chorionic membrane and accessory cells (follicle cells attached to the outside of the chorion and test cells covering the inner surface of the chorion), show bilateral expression of Ci-pitx. This suggested that the chorion or accessory cells are needed for generation of asymmetry. Here, we show that a brief treatment with 60% artificial seawater (ASW) before, but not after, the neurula stage results in bilateral expression of Ci-pitx in the chorion of tailbud embryos, loss of follicle cells, and randomization of both the direction of tail curling and the locations of photoreceptors in larvae. This treatment also impaired the transient counterclockwise rotation within the chorion at the neurula stage. Nearly all test cells in the chorion died following 60% ASW treatment. These results suggest that dead test cells blocked the neural rotation and impaired left-right asymmetry. We also showed that tailbud embryos and larvae generated from defolliculated eggs produced by 80% ASW treatment, in which the test cells were alive, showed normal left-right asymmetry, suggesting that the follicle cells were not essential for asymmetric morphogenesis.

Transient functional suppression and facilitation of Japanese ideogram writing induced by repetitive transcranial magnetic stimulation of posterior inferior temporal cortex.

PubMed

Ueki, Yoshino; Mima, Tatsuya; Nakamura, Kimihiro; Oga, Tatsuhide; Shibasaki, Hiroshi; Nagamine, Takashi; Fukuyama, Hidenao

2006-08-16

The Japanese writing system is unique in that it is composed of two different orthographies: kanji (morphograms) and kana (syllabograms). The retrieval of the visual orthographic representations of Japanese kanji is crucial to the process of writing in Japanese. We used low-frequency repetitive transcranial magnetic stimulation (rTMS) to clarify the functional relevance of the left and right posterior inferior temporal cortex (PITC) to this process in native Japanese speakers. The experimental paradigms included the mental recall of kanji, kana-to-kanji transcription, semantic judgment, oral reading, and copying of kana and kanji. The first two tasks require the visualization of the kanji image of the word. We applied 0.9 Hz rTMS (600 total pulses) over individually determined left or right PITC to suppress cortical activity and measured subsequent task performance. In the mental recall of kanji and kana-to-kanji transcription, rTMS over the left PITC prolonged reaction times (RTs), whereas rTMS over the right PITC reduced RTs. In the other tasks, which do not involve the mental visualization of kanji, rTMS over the left or right PITC had no effect on performance. These results suggest that the left PITC is crucial for the retrieval of the visual graphic representation of kanji. Furthermore, the right PITC may work to suppress the dominant left PITC in the neural network for kanji writing, which involves visual word recognition.

Electrocardiography as a Tool for Validating Myocardial Ischemia–Reperfusion Procedures in Mice

PubMed Central

Preda, Mihai B; Burlacu, Alexandrina

2010-01-01

This paper evaluates the modifications induced by ischemia and ischemia–reperfusion in mice after permanent or transient, respectively, ligation of the left coronary artery and establishes a correlation among the extent of ischemia, electrocardiograph features, and infarct size. The left coronary artery was ligated 1 mm distal from the tip of the left auricle. Histologic analysis revealed that 30-min ischemia (n = 9) led to infarction involving 9.7% ± 0.5% of the left ventricle, whereas 1-h ischemia (n = 9) resulted in transmural infarction of 16.1% ± 4.6% of the left ventricle. In contrast, 24-h ischemia (n = 8) and permanent ischemia (n = 8) induced similarly sized infarcts (33% ± 2% and 31.8% ± 0.7%, respectively), suggesting ineffective reperfusion after 24-h ischemia. Electrocardiography revealed that ligation of the left coronary artery led to ST height elevation (204 compared with 14 μV) and QTc prolongation (136 compared with 76 ms). Both parameters rapidly normalized on reperfusion, demonstrating that electrocardiography was important for validating correct ligation and reperfusion. In addition, electrocardiography predicted the severity of the myocardial damage induced by ischemia. Our results show that electrocardiographic changes present after 30-min ischemia were reversed on reperfusion; however, prolonged ischemia induced pathologic electrocardiographic patterns that remained even after reperfusion. The mouse model of myocardial ischemia–reperfusion can be improved by using electrocardiography to validate ligation and reperfusion during surgery and to predict the severity of infarction. PMID:21262130

Microgravity

NASA Image and Video Library

2000-04-14

Representatives of NASA materials science experiments supported the NASA exhibit at the Rernselaer Polytechnic Institute's Space Week activities, April 5 through 11, 1999. From left to right are: Angie Jackman, project manager at NASA's Marshall Space Flight Center for dendritic growth experiments; Dr. Martin Glicksman of Rennselaer Polytechnic Instutute, Troy, NY, principal investigator on the Isothermal Dendritic Growth Experiment (IDGE) that flew three times on the Space Shuttle; and Dr. Matthew Koss of College of the Holy Cross in Worcester, MA, a co-investigator on the IDGE and now principal investigator on the Transient Dendritic Solidification Experiment being developed for the International Space Station (ISS). The image at far left is a dendrite grown in Glicksman's IDGE tests aboard the Shuttle. Glicksman is also principal investigator for the Evolution of Local Microstructures: Spatial Instabilities of Coarsening Clusters.

Association between left ventricular perfusion defects and myocardial deformation indexes in heart transplantation recipients.

PubMed

D'Andrea, Antonello; De Rimini, Maria Luisa; America, Raffaella; Cirillo, Chiara; Riegler, Lucia; Limongelli, Giuseppe; D'Alto, Michele; Salerno, Gemma; Maiello, Ciro; Muto, Pietro; Russo, Maria Giovanna; Calabrò, Raffaele; Bossone, Eduardo; Pacileo, Giuseppe

2017-10-01

The aim of the study was to analyze possible correlations between strain echocardiography (STE) and PET myocardial perfusion in a population of heart transplantation (HTx) recipients showing preserved left ventricular (LV) ejection fraction. By STE, LV global longitudinal strain (LV GLS) was lower in HTx. PET showed no transient or chronic ischemia in 83 of 115 HTx (73%). Fixed perfusion defects were observed in 17% of HTx and reversible ischemia in 10%. Significant coronary stenosis was observed only in 10 cases. GLS was independently associated with age at HTx and fixed perfusion defects (HR 0.41; P<.001). Such relationships underline STE ability to early identify HTx pts with subclinical myocardial dysfunction during long-term follow-up. © 2017, Wiley Periodicals, Inc.

Life-Threatening Complication During Percutaneous Ablation of Adrenal Gland Metastasis: Takotsubo Syndrome

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

Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Buy, Xavier, E-mail: Xavier.buy@chru-strasbourg.f; Zickler, Pierre, E-mail: pierre.zickler@chru-strasbourg.f

2010-06-15

A rare life-threatening complication during percutaneous cryoablation of an adrenal gland metastasis from a lung carcinoma is reported. The patient presented hypertensive crisis at the beginning of the thawing cycle, followed by electrocardiographic change which necessitated interruption of the procedure and his transfer to the intensive care unit with suspicion of heart infarct. There was a slight increase in cardiac enzyme levels, and ventricular angiography demonstrated transient hypokinesis-dyskinesis of the mid left ventricular segments without apical involvement, while the coronary arteries showed no significant stenosis on coronarography. These findings led to the diagnosis of Takotsubo cardiomyopathy left ventricular dysfunction syndrome.more » This is the first case of Takotsubo cardiomyopathy occurring as a complication during percutaneous ablation of an adrenal gland tumor.« less

An adolescent with intact motor skills and intelligence after infant hemorrhagic stroke without rehabilitation therapy: a case report.

PubMed

Lee, Shenghuo; Yan, Tiebin; Lu, Xiao

2012-01-01

Devastating intracerebral hemorrhagic stroke is rarely encountered in children, but it has a high mortality rate. The case of a 15-year-old boy who survived a major stroke at 40 days old is described. He showed no significant motor or intelligence impairment in adolescence until he was hospitalized for transient left had tremors and slight left hand weakness caused by a cyst. The patient's almost complete motor recovery highlights the power of neural plasticity in young patients. The pediatric stroke was huge, but this did not affect his adolescent movement or intelligence, demonstrating the great neuroplastic potential of the developing human brain. These observations may help increase our knowledge about stroke in children and improve the treatment of pediatric stroke patients.

Clinics in diagnostic imaging (163). Transient lateral patellar dislocation with trochlear dysplasia

PubMed Central

Zhang, Junwei; Lee, Chin Hwee

2015-01-01

A 14-year-old girl presented with left knee pain and swelling after an injury. Magnetic resonance (MR) imaging showed a transient lateral patellar dislocation with patellar osteochondral fracture, medial patellofemoral ligament tear and underlying femoral trochlear dysplasia. Open reduction and internal fixation of the osteochondral fracture, plication of the medial patellar retinaculum and lateral release were performed. As lateral patellar dislocation is often clinically unsuspected, an understanding of its characteristic imaging features is important in making the diagnosis. Knowledge of the various predisposing factors for patellar instability may also influence the choice of surgical management. We also discuss signs of acute injury and chronic instability observed on MR imaging, and the imaging features of anatomical variants that predispose an individual to lateral patellar dislocation. Treatment options and postsurgical imaging appearances are also briefly described. PMID:26512145

Takotsubo cardiomyopathy: Pathophysiology, diagnosis and treatment.

PubMed

Komamura, Kazuo; Fukui, Miho; Iwasaku, Toshihiro; Hirotani, Shinichi; Masuyama, Tohru

2014-07-26

In 1990, takotsubo cardiomyopathy (TCM) was first discovered and reported by a Japanese cardiovascular specialist. Since then, this heart disease has gained worldwide acceptance as an independent disease entity. TCM is an important entity that differs from acute myocardial infarction. It occurs more often in postmenopausal elderly women, is characterized by a transient hypokinesis of the left ventricular (LV) apex, and is associated with emotional or physical stress. Wall motion abnormality of the LV apex is generally transient and resolves within a few days to several weeks. Its prognosis is generally good. However, there are some reports of serious TCM complications, including hypotension, heart failure, ventricular rupture, thrombosis involving the LV apex, and torsade de pointes. It has been suggested that coronary spasm, coronary microvascular dysfunction, catecholamine toxicity and myocarditis might contribute to the pathogenesis of TCM. However, its pathophysiology is not clearly understood.

The Nature of the Remarkable Transient GRB 110328A

NASA Astrophysics Data System (ADS)

Fruchter, Andrew

2010-09-01

One orbit was approved for GO/DD 12447. The PI was given permission to use time under his related approved GRB program, 12370, for subsequent observations of this GRB. To allow the second visit to go forward quickly, it was kept on the schedule as GO/DD 12447, but the orbit was charged to GO 12370. As a result, THE SECOND VISIT OF 12447 HAS THE PROPRIETARY PERIOD ASSOCIATED WITH 12370. We apologize for the confusion caused by this change. However, it was done to allow rapid observations of an unusual astrophysical object.We propose HST observations of the extraordinary transient, GRB 110328A. This object triggered the Swift automatic burst detection twice over the course of about ninety minutes, and has continued to be a bright X-ray source for the two days since. While this behavior might typically suggest a Galactic source, the high Galactic latitude of the object, and its coincidence with a star-forming galaxy at z=0.35 instead suggests a new type of extragalactic transient. WFC3 imaging in the optical and NIR will allow us to search for a varying point source to far greater depth than could be done from the ground, given the presence of an apparent host, and the use of the F160W filter may allow us to pierce enshrouding dust, if extinction is the reason for the present lack of a detection in the optical. While we do not yet know the astrophysical source of this transient, it appears unique among the hundreds of transients so far detected by Swift. This alone should provide strong grounds for HST observations of this unusual and potentially important object.

Direct observation of back energy transfer in blue phosphorescent materials for organic light emitting diodes by time-resolved optical waveguide spectroscopy.

PubMed

Hirayama, H; Sugawara, Y; Miyashita, Y; Mitsuishi, M; Miyashita, T

2013-02-25

We demonstrate a high-sensitive transient absorption technique for detection of excited states in an organic thin film by time-resolved optical waveguide spectroscopy. By using a laser beam as a probe light, we detect small change in the transient absorbance which is equivalent to 10 -7 absorbance unit in a conventional method. This technique was applied to organic thin films of blue phosphorescent materials for organic light emitting diodes. We directly observed the back energy transfer from emitting guest molecules to conductive host molecules.

[Study on transient absorption spectrum of tungsten nanoparticle with HepG2 tumor cell].

PubMed

Cao, Lin; Shu, Xiao-Ning; Liang, Dong; Wang, Cong

2014-07-01

Significance of this study lies in tungsten nano materials can be used as a preliminary innovative medicines applied basic research. This paper investigated the inhibition of tungsten nanoparticles which effected on human hepatoma HepG2 cells by MTT. The authors use transient absorption spectroscopy (TAS) technology absorption and emission spectra characterization of charge transfer between nanoparticles and tumor cell. The authors discussed the role of the tungsten nanoparticles in the tumor early detection of the disease and its anti-tumor properties. In the HepG2 experiments system, 100-150 microg x mL(-1) is the best drug concentration of anti-tumor activity which recact violently within 6 hours and basically completed in 24 hours. The results showed that transient absorption spectroscopy can be used as tumor detection methods and characterization of charge transfer between nano-biosensors and tumor cells. Tungsten nanoparticles have potential applications as anticancer drugs.

Transient astronomy with the Gaia satellite.

PubMed

Hodgkin, Simon T; Wyrzykowski, Łukasz; Blagorodnova, Nadejda; Koposov, Sergey

2013-06-13

Gaia is a cornerstone European Space Agency astrometry space mission and a successor to the Hipparcos mission. Gaia will observe the whole sky for 5 years, providing a serendipitous opportunity for the discovery of large numbers of transient and anomalous events, e.g. supernovae, novae and microlensing events, gamma-ray burst afterglows, fallback supernovae, as well as theoretical or unexpected phenomena. In this paper, we discuss our preparations to use Gaia to search for transients at optical wavelengths, and briefly describe the early detection, classification and prompt publication of anomalous sources.

Radio Non-Detection of the Currently Outbursting Transient Source in NGC 6440

NASA Astrophysics Data System (ADS)

Tetarenko, A. J.; Bahramian, A.; Sivakoff, G. R.; Heinke, C. O.; Shaw, A. W.; Wijnands, R.; Degenaar, N.; Miller-Jones, J. C. A.; Kuulkers, R. Plotkin E.; Chomiuk, L.; Strader, J.; Tremou, E.; Kennea, J. A.; Altamirano, D.; in't Zand, J. J. M.; Deller, A.; Maccarone, T. J.

2017-10-01

We report follow-up VLA radio observations of NGC 6440, which has recently shown evidence of transient X-ray activity (ATel #10821, #10826). Our VLA observations occurred on 2017 Oct 11, with scans on source between 01:07:09 - 02:48:18 UTC (MJD = 58037.0466 - 58037.1169), in X band (8 - 12 GHz).

Dichotic listening in patients with splenial and nonsplenial callosal lesions.

PubMed

Pollmann, Stefan; Maertens, Marianne; von Cramon, D Yves; Lepsien, Joeran; Hugdahl, Kenneth

2002-01-01

The authors found splenial lesions to be associated with left ear suppression in dichotic listening of consonant-vowel syllables. This was found in both a rapid presentation dichotic monitoring task and a standard dichotic listening task, ruling out attentional limitations in the processing of high stimulus loads as a confounding factor. Moreover, directed attention to the left ear did not improve left ear target detection in the patients, independent of callosal lesion location. The authors' data may indicate that auditory callosal fibers pass through the splenium more posterior than previously thought. However, further studies should investigate whether callosal fibers between primary and secondary auditory cortices, or between higher level multimodal cortices, are vital for the detection of left ear targets in dichotic listening.

Left-handers show no self-advantage in detecting a delay in visual feedback concerning an active movement.

PubMed

Hoover, Adria E N; Elzein, Yasmeenah; Harris, Laurence R

2016-07-01

Right-handed people show an advantage in detecting a delay in visual feedback concerning an active movement of their right hand when it is viewed in a natural perspective compared to when it is seen as if viewing another person's hand (Hoover and Harris in Exp Brain Res 233:1053-1060, 2012. doi: 10.1007/s00221-014-4181-9 ; Exp Brain Res 222:389-397, 2015a. doi: 10.1007/s00221-012-3224-3 ). This self-advantage is unique to their dominant hand and may reflect an enhanced sense of ownership which contributes to how right-handed people relate to the world. Here we asked whether left-handers show the same pattern of performance for their dominant hand. We measured the minimum delay that could be detected by 29 left-handers when viewing either their dominant or non-dominant hand from 'self' or 'other' perspectives and compared their thresholds to an age-matched sample of 22 right-handers. Right-handers showed a significant signature self-advantage of 19 ms when viewing their dominant hand in an expected 'self' perspective compared to 'other' perspectives. Left-handers, however, showed no such advantage for either their dominant or non-dominant hand. This lack of self-advantage in detecting delayed visual feedback might indicate a less secure sense of body ownership amongst left-handers.

Asteroids in the High Cadence Transient Survey

NASA Astrophysics Data System (ADS)

Peña, J.; Fuentes, C.; Förster, F.; Maureira, J. C.; San Martín, J.; Littín, J.; Huijse, P.; Cabrera-Vives, G.; Estévez, P. A.; Galbany, L.; González-Gaitán, S.; Martínez, J.; de Jaeger, Th.; Hamuy, M.

2018-03-01

We report on the serendipitous observations of solar system objects imaged during the High cadence Transient Survey 2014 observation campaign. Data from this high-cadence wide-field survey was originally analyzed for finding variable static sources using machine learning to select the most-likely candidates. In this work, we search for moving transients consistent with solar system objects and derive their orbital parameters. We use a simple, custom motion detection algorithm to link trajectories and assume Keplerian motion to derive the asteroid’s orbital parameters. We use known asteroids from the Minor Planet Center database to assess the detection efficiency of the survey and our search algorithm. Trajectories have an average of nine detections spread over two days, and our fit yields typical errors of {σ }a∼ 0.07 {au}, σ e ∼ 0.07 and σ i ∼ 0.°5 in semimajor axis, eccentricity, and inclination, respectively, for known asteroids in our sample. We extract 7700 orbits from our trajectories, identifying 19 near-Earth objects, 6687 asteroids, 14 Centaurs, and 15 trans-Neptunian objects. This highlights the complementarity of supernova wide-field surveys for solar system research and the significance of machine learning to clean data of false detections. It is a good example of the data-driven science that Large Synoptic Survey Telescope will deliver.

An investigation on die crack detection using Temperature Sensitive Parameter for high speed LED mass production

NASA Astrophysics Data System (ADS)

Annaniah, Luruthudass; Devarajan, Mutharasu; San, Teoh Kok

To ensure the highest quality & long-term reliability of LED components it is necessary to examine LED dice that have sustained mechanical damage during the manufacturing process. This paper has demonstrated that detection of die crack in mass manufactured LEDs can be achieved by measuring Temperature Sensitive Parameters (TSPs) during final testing. A newly-designed apparatus and microcontroller was used for this investigation in order to achieve the millisecond switching time needed for detecting thermal transient effects and at the same time meet the expected speed for mass manufacturing. Evaluations conducted at lab scale shows that thermal transient behaviour of cracked die is significantly different than that of an undamaged die. Having an established test limits to differentiate cracked dice, large volume tests in a production environment were used to confirm the effectiveness of this test method. Failure Bin Analysis (FBA) of this high volume experiment confirmed that all the cracked die LEDs were detected and the undamaged LEDs passed this test without over-rejection. The work verifies that tests based on TSP are effective in identifying die cracks and it is believed that the method could be extended to other types of rejects that have thermal transient signatures such as die delamination.

Neutrino masses and leptogenesis in left-right symmetric models: a review from a model building perspective

NASA Astrophysics Data System (ADS)

Hati, Chandan; Patra, Sudhanwa; Pritimita, Prativa; Sarkar, Utpal

2018-03-01

In this review, we present several variants of left-right symmetric models in the context of neutrino masses and leptogenesis. In particular, we discuss various low scale seesaw mechanisms like linear seesaw, inverse seesaw, extended seesaw and their implications to lepton number violating process like neutrinoless double beta decay. We also visit an alternative framework of left-right models with the inclusion of vector-like fermions to analyze the aspects of universal seesaw. The symmetry breaking of left-right symmetric model around few TeV scale predicts the existence of massive right-handed gauge bosons W_R and Z_R which might be detected at the LHC in near future. If such signals are detected at the LHC that can have severe implications for leptogenesis, a mechanism to explain the observed baryon asymmetry of the Universe. We review the implications of TeV scale left-right symmetry breaking for leptogenesis.

Percutaneous fiber optic angioscopy of the left ventricle in patients with rheumatic valvular disease

NASA Astrophysics Data System (ADS)

Hirose, Junichi; Oshima, Tomomitsu; Fujimori, Yoshiharu; Uchida, Yasumi

1993-05-01

Recent advances in fiberoptic technology enabled us to observe percutaneously the cardiac chambers and valves. We examined left ventricular luminal and valvular changes by percutaneous fiberoptic angioscopy in patients with rheumatic valvular disease. Six patients with echocardiographic rheumatic changes in the mitral valves, underwent angioscopy during routine cardiac catheterization. The fiberscope 4.2 F in diameter, and the guiding catheter 9 F in external diameter with an inflatable balloon around the distal most tip were used for angioscopy. The left ventricular endocardial surface was diffusely white in color or white and brown in mosaic fashion. Echocardiography and angiography had low sensitivity for detecting the changes of the left ventricular luminal surface. Whitish changes which were observed by angioscopy were not related to the indices derived from echocardiography and angiography. The results indicate the possibility of percutaneous angioscopy in detecting left ventricular luminal changes in patients with rheumatic valvular disease.

Physical limits of flow sensing in the left-right organizer

PubMed Central

Ferreira, Rita R; Vilfan, Andrej; Jülicher, Frank; Supatto, Willy; Vermot, Julien

2017-01-01

Fluid flows generated by motile cilia are guiding the establishment of the left-right asymmetry of the body in the vertebrate left-right organizer. Competing hypotheses have been proposed: the direction of flow is sensed either through mechanosensation, or via the detection of chemical signals transported in the flow. We investigated the physical limits of flow detection to clarify which mechanisms could be reliably used for symmetry breaking. We integrated parameters describing cilia distribution and orientation obtained in vivo in zebrafish into a multiscale physical study of flow generation and detection. Our results show that the number of immotile cilia is too small to ensure robust left and right determination by mechanosensing, given the large spatial variability of the flow. However, motile cilia could sense their own motion by a yet unknown mechanism. Finally, transport of chemical signals by the flow can provide a simple and reliable mechanism of asymmetry establishment. DOI: http://dx.doi.org/10.7554/eLife.25078.001 PMID:28613157

Impact of transcranial direct current stimulation on attentional bias for threat: a proof-of-concept study among individuals with social anxiety disorder

PubMed Central

Billieux, Joël; Philippot, Pierre; De Raedt, Rudi; Baeken, Chris; de Timary, Philippe; Maurage, Pierre; Vanderhasselt, Marie-Anne

2017-01-01

Abstract Cognitive models posit that social anxiety disorder (SAD) is associated with and maintained by attentional bias (AB) for social threat. However, over the last years, it has been suggested that AB in SAD may result from a decreased activation of the left prefrontal cortex, and particularly of its dorsolateral part (dlPFC). Accordingly, a transient increase of neural activity within the left dlPFC via non-invasive brain stimulation decreases AB in non-anxious control participants. Yet, none of these studies focused on SAD. This is especially unfortunate as SAD constitutes the main target for which a genuine reduction of AB may be most appropriate. In this experiment, we sought to investigate the causal influence of left dlPFC neuromodulation on AB among 19 female individuals with a DSM-5 diagnosis of SAD. We adopted a double-blind within-subject protocol in which we delivered a single-session of anodal versus sham transcranial Direct Current Stimulation (tDCS) over the left dlPFC during the completion of a probe discrimination task assessing AB. Consistent with our hypothesis, participants demonstrated a significant decrease in AB during the anodal tDCS over the left DLPFC relative to the sham stimulation. These findings value tDCS as an innovative procedure to gain new insight into the underlying mechanisms of SAD. PMID:27531388

M.I.T. studies of transient X-ray phenomena. [astronomical observations

NASA Technical Reports Server (NTRS)

Canizares, C. R.

1976-01-01

A variety of transient X-ray phenomena have been studied. Data from the OSO-7 satellite reveal both long and short time-scale transients. Extensive observations have been made of the Lupus X-ray Nova (3U1543-47) and GX339-4(MX 1658-48) which may represent a very different type of transient source. A unique, intense X-ray flare lasting ten minutes was also recorded, and the X-ray emission from the active galaxy Cen A was found to vary significantly over a period of several days. In a recent balloon flight the Crab pulsar, NP0532, was observed to exhibit a transient pulsed component distinct from the usual main pulse and interpulse. A sounding-rocket experiment detected an ultrasoft transient X-ray source tentatively associated with SS Cygni, and preliminary results from SAS-3 show a very hard spectrum for the new source A0535 + 26. On the other hand, extensive OSO-7 null observations of both Type I and II supernovae and of the flaring radio star Algol make it unlikely that these types of objects are potent transient X-ray emitters.

Evaluation of a multi-channel algorithm for reducing transient sounds.

PubMed

Keshavarzi, Mahmoud; Baer, Thomas; Moore, Brian C J

2018-05-15

The objective was to evaluate and select appropriate parameters for a multi-channel transient reduction (MCTR) algorithm for detecting and attenuating transient sounds in speech. In each trial, the same sentence was played twice. A transient sound was presented in both sentences, but its level varied across the two depending on whether or not it had been processed by the MCTR and on the "strength" of the processing. The participant indicated their preference for which one was better and by how much in terms of the balance between the annoyance produced by the transient and the audibility of the transient (they were told that the transient should still be audible). Twenty English-speaking participants were tested, 10 with normal hearing and 10 with mild-to-moderate hearing-impairment. Frequency-dependent linear amplification was provided for the latter. The results for both participant groups indicated that sounds processed using the MCTR were preferred over the unprocessed sounds. For the hearing-impaired participants, the medium and strong settings of the MCTR were preferred over the weak setting. The medium and strong settings of the MCTR reduced the annoyance produced by the transients while maintaining their audibility.

MDCT detection of anomalous origins of the left main coronary artery: report of 2 cases.

PubMed

Matsumoto, Naoya; Sato, Yuichi; Kunimasa, Taeko; Yoda, Shunichi; Yokoyama, Shinichiro; Takayama, Tadateru; Komatsu, Sei; Achenbach, Stephan; Saito, Satoshi; Hirayama, Atsushi

2008-11-28

The left main coronary artery (LMCA) arising either from the right sinus of Valsalva, separately from the right coronary artery (RCA), or from the RCA as a single coronary artery is an extremely rare coronary artery anomaly. We report 2 cases of anomalous origins of the LMCA detected by multidetector-row computed tomography.

Analysis of temperature profile and electric field in natural rubber glove due to microwave heating: effects of waveguide position

NASA Astrophysics Data System (ADS)

Keangin, P.; Narumitbowonkul, U.; Rattanadecho, P.

2018-01-01

Natural rubber (NR) is the key raw material used in the manufacture of other products such as rubber band, tire and shoes. Recently, the NR is used in natural rubber glove ( NRG) manufacturing in the industrial and medical fields. This research aims to investigate the electromagnetic wave propagation and heat transfer in NRG due to heating with microwave energy within the microwave oven at a microwave frequency of 2.45 GHz. Three-dimensional model of NRG and microwave oven are considered in this work. The comparative effects of waveguide position on the electric field and temperature profile in NRG when subjected to microwave energy are discussed. The finite element method (FEM) is used to solve the transient Maxwell’s equation coupled with the transient heat transfer equation. The simulation results with computer programs are validated with experimental results. The placement of waveguides in three cases are left hand side of microwave oven, right hand side of microwave oven and left and right hand sides of microwave oven are investigated. The findings revealed that the placing the waveguide on the right side of the microwave oven gives the highest electric field and temperature profile. The values obtained provide an indication toward understanding the study of heat transfer in NRG during microwave heating in the industry.

Altered Left Ventricular Ion Channel Transcriptome in a High-Fat-Fed Rat Model of Obesity: Insight into Obesity-Induced Arrhythmogenesis

PubMed Central

Yon, Marianne; Pickavance, Lucy; Yanni Gerges, Joseph; Davis, Gershan; Wilding, John; Jian, Kun; Hart, George; Boyett, Mark

2016-01-01

Introduction. Obesity is increasingly common and is associated with an increased prevalence of cardiac arrhythmias. The aim of this study was to see whether in obesity there is proarrhythmic gene expression of ventricular ion channels and related molecules. Methods and Results. Rats were fed on a high-fat diet and compared to control rats on a normal diet (n = 8). After 8 weeks, rats on the high-fat diet showed significantly greater weight gain and higher adiposity. Left ventricle samples were removed at 8 weeks and mRNA expression of ion channels and other molecules was measured using qPCR. Obese rats had significant upregulation of Cav1.2, HCN4, Kir2.1, RYR2, NCX1, SERCA2a, and RYR2 mRNA and downregulation of ERG mRNA. In the case of HCN4, it was confirmed that there was a significant increase in protein expression. The potential effects of the mRNA changes on the ventricular action potential and intracellular Ca2+ transient were predicted using computer modelling. Modelling predicted prolongation of the ventricular action potential and an increase in the intracellular Ca2+ transient, both of which would be expected to be arrhythmogenic. Conclusion. High-fat diet causing obesity results in arrhythmogenic cardiac gene expression of ion channels and related molecules. PMID:27747100

Transient chaos - a resolution of breakdown of quantum-classical correspondence in optomechanics.

PubMed

Wang, Guanglei; Lai, Ying-Cheng; Grebogi, Celso

2016-10-17

Recently, the phenomenon of quantum-classical correspondence breakdown was uncovered in optomechanics, where in the classical regime the system exhibits chaos but in the corresponding quantum regime the motion is regular - there appears to be no signature of classical chaos whatsoever in the corresponding quantum system, generating a paradox. We find that transient chaos, besides being a physically meaningful phenomenon by itself, provides a resolution. Using the method of quantum state diffusion to simulate the system dynamics subject to continuous homodyne detection, we uncover transient chaos associated with quantum trajectories. The transient behavior is consistent with chaos in the classical limit, while the long term evolution of the quantum system is regular. Transient chaos thus serves as a bridge for the quantum-classical transition (QCT). Strikingly, as the system transitions from the quantum to the classical regime, the average chaotic transient lifetime increases dramatically (faster than the Ehrenfest time characterizing the QCT for isolated quantum systems). We develop a physical theory to explain the scaling law.

Transient chaos - a resolution of breakdown of quantum-classical correspondence in optomechanics

PubMed Central

Wang, Guanglei; Lai, Ying-Cheng; Grebogi, Celso

2016-01-01

Recently, the phenomenon of quantum-classical correspondence breakdown was uncovered in optomechanics, where in the classical regime the system exhibits chaos but in the corresponding quantum regime the motion is regular - there appears to be no signature of classical chaos whatsoever in the corresponding quantum system, generating a paradox. We find that transient chaos, besides being a physically meaningful phenomenon by itself, provides a resolution. Using the method of quantum state diffusion to simulate the system dynamics subject to continuous homodyne detection, we uncover transient chaos associated with quantum trajectories. The transient behavior is consistent with chaos in the classical limit, while the long term evolution of the quantum system is regular. Transient chaos thus serves as a bridge for the quantum-classical transition (QCT). Strikingly, as the system transitions from the quantum to the classical regime, the average chaotic transient lifetime increases dramatically (faster than the Ehrenfest time characterizing the QCT for isolated quantum systems). We develop a physical theory to explain the scaling law. PMID:27748418

Electromagnetic transients as triggers in searches for gravitational waves from compact binary mergers

NASA Astrophysics Data System (ADS)

Kelley, Luke Zoltan; Mandel, Ilya; Ramirez-Ruiz, Enrico

2013-06-01

The detection of an electromagnetic transient which may originate from a binary neutron star merger can increase the probability that a given segment of data from the LIGO-Virgo ground-based gravitational-wave detector network contains a signal from a binary coalescence. Additional information contained in the electromagnetic signal, such as the sky location or distance to the source, can help rule out false alarms and thus lower the necessary threshold for a detection. Here, we develop a framework for determining how much sensitivity is added to a gravitational-wave search by triggering on an electromagnetic transient. We apply this framework to a variety of relevant electromagnetic transients, from short gamma-ray bursts (GRBs) to signatures of r-process heating to optical and radio orphan afterglows. We compute the expected rates of multimessenger observations in the advanced detector era and find that searches triggered on short GRBs—with current high-energy instruments, such as Fermi—and nucleosynthetic “kilonovae”—with future optical surveys, like the Large Synoptic Survey Telescope—can boost the number of multimessenger detections by 15% and 40%, respectively, for a binary neutron star progenitor model. Short GRB triggers offer precise merger timing but suffer from detection rates decreased by beaming and the high a priori probability that the source is outside the LIGO-Virgo sensitive volume. Isotropic kilonovae, on the other hand, could be commonly observed within the LIGO-Virgo sensitive volume with an instrument roughly an order of magnitude more sensitive than current optical surveys. We propose that the most productive strategy for making multimessenger gravitational-wave observations is using triggers from future deep, optical all-sky surveys, with characteristics comparable to the Large Synoptic Survey Telescope, which could make as many as ten such coincident observations a year.

Triggered Firing and Atrial Fibrillation in Transgenic Mice With Selective Atrial Fibrosis Induced by Overexpression of TGF-β1

PubMed Central

Choi, Eue-Keun; Chang, Po-Cheng; Lee, Young-Soo; Lin, Shien-Fong; Zhu, Wuqiang; Maruyama, Mitsunori; Fishbein, Michael C.; Chen, Zhenhui; der Lohe, Michael Rubart-von; Field, Loren J.; Chen, Peng-Sheng

2013-01-01

Background Calcium transient triggered firing (CTTF) is induced by large intracellular calcium (Cai) transient and short action potential duration (APD). We hypothesized that CTTF underlies the mechanisms of early afterdepolarization (EAD) and spontaneous recurrent atrial fibrillation (AF) in transgenic (Tx) mice with overexpression of transforming growth factor β1 (TGF-β1). Methods and Results MHC-TGFcys33ser Tx mice develop atrial fibrosis because of elevated levels of TGF-β1. We studied membrane potential and Cai transients of isolated superfused atria from Tx and wild-type (Wt) littermates. Short APD and persistently elevated Cai transients promoted spontaneous repetitive EADs, triggered activity and spontaneous AF after cessation of burst pacing in Tx but not Wt atria (39% vs. 0%, P=0.008). We were able to map optically 4 episodes of spontaneous AF re-initiation. All first and second beats of spontaneous AF originated from the right atrium (4/4, 100%), which is more severely fibrotic than the left atrium. Ryanodine and thapsigargin inhibited spontaneous re-initiation of AF in all 7 Tx atria tested. Western blotting showed no significant changes of calsequestrin or sarco/endoplasmic reticulum Ca2+-ATPase 2a. Conclusions Spontaneous AF may occur in the Tx atrium because of CTTF, characterized by APD shortening, prolonged Cai transient, EAD and triggered activity. Inhibition of Ca2+ release from the sarcoplasmic reticulum suppressed spontaneous AF. Our results indicate that CTTF is an important arrhythmogenic mechanism in TGF-β1 Tx atria. PMID:22447020

Hemozoin-generated vapor nanobubbles for transdermal reagent- and needle-free detection of malaria

PubMed Central

Lukianova-Hleb, Ekaterina Y.; Campbell, Kelly M.; Constantinou, Pamela E.; Braam, Janet; Olson, John S.; Ware, Russell E.; Sullivan, David J.; Lapotko, Dmitri O.

2014-01-01

Successful diagnosis, screening, and elimination of malaria critically depend on rapid and sensitive detection of this dangerous infection, preferably transdermally and without sophisticated reagents or blood drawing. Such diagnostic methods are not currently available. Here we show that the high optical absorbance and nanosize of endogenous heme nanoparticles called “hemozoin,” a unique component of all blood-stage malaria parasites, generates a transient vapor nanobubble around hemozoin in response to a short and safe near-infrared picosecond laser pulse. The acoustic signals of these malaria-specific nanobubbles provided transdermal noninvasive and rapid detection of a malaria infection as low as 0.00034% in animals without using any reagents or drawing blood. These on-demand transient events have no analogs among current malaria markers and probes, can detect and screen malaria in seconds, and can be realized as a compact, easy-to-use, inexpensive, and safe field technology. PMID:24379385

Hemozoin-generated vapor nanobubbles for transdermal reagent- and needle-free detection of malaria.

PubMed

Lukianova-Hleb, Ekaterina Y; Campbell, Kelly M; Constantinou, Pamela E; Braam, Janet; Olson, John S; Ware, Russell E; Sullivan, David J; Lapotko, Dmitri O

2014-01-21

Successful diagnosis, screening, and elimination of malaria critically depend on rapid and sensitive detection of this dangerous infection, preferably transdermally and without sophisticated reagents or blood drawing. Such diagnostic methods are not currently available. Here we show that the high optical absorbance and nanosize of endogenous heme nanoparticles called "hemozoin," a unique component of all blood-stage malaria parasites, generates a transient vapor nanobubble around hemozoin in response to a short and safe near-infrared picosecond laser pulse. The acoustic signals of these malaria-specific nanobubbles provided transdermal noninvasive and rapid detection of a malaria infection as low as 0.00034% in animals without using any reagents or drawing blood. These on-demand transient events have no analogs among current malaria markers and probes, can detect and screen malaria in seconds, and can be realized as a compact, easy-to-use, inexpensive, and safe field technology.

OBSERVATIONS OF ROTATING RADIO TRANSIENTS WITH THE FIRST STATION OF THE LONG WAVELENGTH ARRAY

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

Taylor, G. B.; Stovall, K.; McCrackan, M.

2016-11-10

Rotating radio transients (RRATs) are a subclass of pulsars first identified in 2006 that are detected only in searches for single pulses and not through their time averaged emission. Here, we present the results of observations of 19 RRATs using the first station of the Long Wavelength Array (LWA1) at frequencies between 30 and 88 MHz. The RRATs observed here were first detected in higher frequency pulsar surveys. Of the 19 RRATs observed, two sources were detected and their dispersion measures, periods, pulse profiles, and flux densities are reported and compared to previous higher frequency measurements. We find a lowmore » detection rate (11%), which could be a combination of the lower sensitivity of LWA1 compared to higher frequency telescopes, and the result of scattering by the interstellar medium or a spectral turnover.« less

Neutrino detection of transient sources with optical follow-up observations

NASA Astrophysics Data System (ADS)

Dornic, D.; Ageron, M.; Al Samarai, I.; Basa, S.; Bertin, V.; Brunner, J.; Busto, J.; Escoffier, S.; Schussler, F.; Vallage, B.; Vecchi, M.

2010-12-01

The ANTARES telescope has the opportunity to detect transient neutrino sources,such as gamma-ray bursts,core-collapse supernovae,flares of active galactic nuclei. To enhance the sensitivity to these sources, a new detection method based on coincident observations of neutrinos and optical signals has been developed. For this purpose the ANTARES Collaboration has implemented a fast on-line muon track reconstruction with a good angular resolution. These characteristics allow to trigger a network of optical telescopes in order to identify the nature of the neutrino sources. An optical follow-up of special events, such as neutrino doublets, coincident in time and direction, or single neutrinos with a very high energy, would not only give access to the nature of their sources but also improve the sensitivity for neutrino detection. The alert system is operational since early 2009, and as of September 2010, 22 alerts have been sent to the TAROT and ROTSE telescopes.

A TRANSIENT SUB-EDDINGTON BLACK HOLE X-RAY BINARY CANDIDATE IN THE DUST LANES OF CENTAURUS A

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

Burke, Mark J.; Raychaudhury, Somak; Kraft, Ralph P.

2012-04-20

We report the discovery of a bright X-ray transient CXOU J132527.6-430023 in the nearby early-type galaxy NGC 5128. The source was first detected over the course of five Chandra observations in 2007, reaching an unabsorbed outburst luminosity of (1-2) Multiplication-Sign 10{sup 38} erg s{sup -1} in the 0.5-7.0 keV band before returning to quiescence. Such luminosities are possible for both stellar-mass black hole and neutron star (NS) X-ray binary transients. Here, we attempt to characterize the nature of the compact object. No counterpart has been detected in the optical or radio sky, but the proximity of the source to themore » dust lanes allows for the possibility of an obscured companion. The brightness of the source after a >100-fold increase in X-ray flux makes it either the first confirmed transient non-ultraluminous X-ray black hole system in outburst to be subject to detailed spectral modeling outside the Local Group, or a bright (>10{sup 38} erg s{sup -1}) transient NS X-ray binary, which are very rare. Such a large increase in flux would appear to lend weight to the view that this is a black hole transient. X-ray spectral fitting of an absorbed power law yielded unphysical photon indices, while the parameters of the best-fit absorbed disk blackbody model are typical of an accreting {approx}10 M{sub Sun} black hole in the thermally dominant state.« less

Outflow-driven Transients from the Birth of Binary Black Holes. I. Tidally Locked Secondary Supernovae

NASA Astrophysics Data System (ADS)

Kimura, Shigeo S.; Murase, Kohta; Mészáros, Peter

2017-12-01

We propose a new type of electromagnetic transient associated with the birth of binary black holes (BBHs), which may lead to merger events accompanied by gravitational waves in ∼ 0.1{--}1 {Gyr}. We consider the newborn BBHs formed through the evolution of isolated massive stellar binaries. For a close massive binary, consisting of a primary black hole (BH) and a secondary Wolf–Rayet (WR) star that are orbiting around each other, the spin period of the WR star can be tidally synchronized to its orbital period. Then the angular momentum of the outer material of the WR star is large enough to form an accretion disk around a newborn, secondary BH, following its core-collapse. This disk may produce an energetic outflow with a kinetic energy of ∼ {10}50{--}{10}52 {erg} and an outflow velocity of ∼ {10}10 {cm} {{{s}}}-1, resulting in an optical transient with an absolute magnitude from approximately ‑14 to approximatley ‑17 with a duration of around a day. This type of transient also produces detectable radio signals ∼ 1{--}10 years after the birth of BBHs, via synchrotron emission from nonthermal electrons accelerated at external shocks. The predicted optical transients have a shorter duration than ordinary core-collapse supernovae. Dedicated optical transient surveys can detect them and distinguish them from ordinary SNe using the different features of its light curve and late-time spectrum. In this paper (Paper I), we investigate disk-driven outflows from the secondary BH, whereas possible signals from the primary BH will be discussed in Paper II.

Characterization of electrical appliances in transient state

NASA Astrophysics Data System (ADS)

Wójcik, Augustyn; Winiecki, Wiesław

2017-08-01

The article contains the study about electrical appliance characterization on the basis of power grid signals. To represent devices, parameters of current and voltage signals recorded during transient states are used. In this paper only transients occurring as a result of switching on devices are considered. The way of data acquisition performed in specialized measurement setup developed for electricity load monitoring is described. The paper presents the method of transients detection and the method of appliance parameters calculation. Using the set of acquired measurement data and appropriate software the set of parameters for several household appliances operating in different operating conditions was processed. Usefulness of appliances characterization in Non-Intrusive Appliance Load Monitoring System (NIALMS) with the use of proposed method is discussed focusing on obtained results.

Supernova and optical transient observations using the three wide-field telescope array of the KMTNet

NASA Astrophysics Data System (ADS)

Moon, Dae-Sik; Kim, Sang Chul; Lee, Jae-Joon; Pak, Mina; Park, Hong Soo; He, Matthias Y.; Antoniadis, John; Ni, Yuan Qi; Lee, Chung-Uk; Kim, Seung-Lee; Park, Byeong-Gon; Kim, Dong-Jin; Cha, Sang-Mok; Lee, Yongseok; Gonzalez, Santiago

2016-08-01

The Korea Microlensing Telescope Network (KMTNet) is a network of three new 1.6-m, wide-field telescopes spread over three different sites in Chile, South Africa and Australia. Each telescope is equipped with a four square degree wide-field CCD camera, making the KMTNet an ideal facility for discovering and monitoring early supernovae and other rapidly evolving optical transients by providing 24-hour continuous sky coverage. We describe our inaugurating program of observing supernovae and optical transients using about 20% of the KMTNet time in 2015-2019. Our early results include detection of infant supernovae, novae and peculiar transients as well as numerous variable stars and low surface brightness objects such as dwarf galaxies.

Minimum depth of investigation for grounded-wire TEM due to self-transients

NASA Astrophysics Data System (ADS)

Zhou, Nannan; Xue, Guoqiang

2018-05-01

The grounded-wire transient electromagnetic method (TEM) has been widely used for near-surface metalliferous prospecting, oil and gas exploration, and hydrogeological surveying in the subsurface. However, it is commonly observed that such TEM signal is contaminated by the self-transient process occurred at the early stage of data acquisition. Correspondingly, there exists a minimum depth of investigation, above which the observed signal is not applicable for reliable data processing and interpretation. Therefore, for achieving a more comprehensive understanding of the TEM method, it is necessary to perform research on the self-transient process and moreover develop an approach for quantifying the minimum detection depth. In this paper, we first analyze the temporal procedure of the equivalent circuit of the TEM method and present a theoretical equation for estimating the self-induction voltage based on the inductor of the transmitting wire. Then, numerical modeling is applied for building the relationship between the minimum depth of investigation and various properties, including resistivity of the earth, offset, and source length. It is guide for the design of survey parameters when the grounded-wire TEM is applied to the shallow detection. Finally, it is verified through applications to a coal field in China.

Pulsating star products from the Palomar Transient Factory: Ultra-long period Cepheids in M31 and RR Lyrae in Kepler field

NASA Astrophysics Data System (ADS)

Ngeow, Chow-Choong

2017-09-01

The Palomar Transient Factory (PTF) and its successor, the intermediate PTF (iPTF), are wide-field synoptic sky surveys aimed to detect transients. Even though the main science goal for PTF/iPTF is to detect various types of transients, the synoptic nature of the surveys can also be used for the study of variable stars. In this proceedings contribution, I will first give a brief introduction to PTF/iPTF, followed by the two pulsating stars studies using the PTF/iPTF data: the Ultra-Long Period Cepheids (ULPC) in M31 and the RR Lyrae in the Kepler field. For the formal study, we searched the M31's ULPC using PTF imaging data, and follow up the candidates with other telescopes. Our finding revealed that there are only two ULPC in M31. I will give a brief implication of our finding in distance scale studies. For the latter study, I will present our work on the derivation of metallicity-light curve relation in native PTF/iPTF R-band using the RRab stars in the Kepler field.

Millimeter transient point sources in the SPTpol 100 square degree survey

DOE PAGES

Whitehorn, N.; Natoli, T.; Ade, P. A. R.; ...

2016-10-18

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg 2 patch of sky centered atmore » R.A. 23 h30 m and decl. –55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. As a result, one candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low (p = 0.01) to confirm detection.« less

MILLIMETER TRANSIENT POINT SOURCES IN THE SPTpol 100 SQUARE DEGREE SURVEY

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

Whitehorn, N.; Haan, T. de; George, E. M.

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg{sup 2} patch of sky centered atmore » R.A. 23{sup h}30{sup m} and decl. −55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. One candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low ( p = 0.01) to confirm detection.« less

Millimeter transient point sources in the SPTpol 100 square degree survey

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

Whitehorn, N.; Natoli, T.; Ade, P. A. R.

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg 2 patch of sky centered atmore » R.A. 23 h30 m and decl. –55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. As a result, one candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low (p = 0.01) to confirm detection.« less

Left Superior Vena Cava Draining Into Left Atrium in Tetralogy of Fallot-Four Cases of a Rare Association.

PubMed

Ramman, Tarun Raina; Dutta, Nilanjan; Chowdhuri, Kuntal Roy; Agrawal, Sunny; Girotra, Sumir; Azad, Sushil; Radhakrishnan, Sitaraman; Iyer, Parvathi Unninayar; Iyer, Krishna Subramony

2018-01-01

Persistent left superior vena cava is a common congenital anomaly of the thoracic venous system. Left superior vena cava draining into left atrium is a malformation of sinus venosus and caval system. The anomaly may be a cause of unexplained hypoxia even in adults. It may give rise to various diagnostic and technical challenges during cardiac catheterization and open-heart surgery. It is often detected serendipitously during diagnostic workup. Isolated left superior vena cava opening into left atrium is very commonly associated with other congenital heart defects. But tetralogy of Fallot is very rarely associated with persistent left superior vena cava which drains into left atrium. We report four such cases who underwent surgical correction successfully.

Detecting Tooth Damage in Geared Drive Trains

NASA Technical Reports Server (NTRS)

Nachtsheim, Philip R.

1997-01-01

This paper describes a method that was developed to detect gear tooth damage that does not require a priori knowledge of the frequency characteristic of the fault. The basic idea of the method is that a few damaged teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the frequency interval which excludes the frequency of the lowest dominant normal tooth load fluctuation and all frequencies above it. The method reacted significantly to the tooth fracture damage results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.

Changes in the expression of DNA-binding/differentiation protein inhibitors in neurons and glial cells of the gerbil hippocampus following transient global cerebral ischemia

PubMed Central

LEE, JAE-CHUL; CHEN, BAI HUI; CHO, JEONG-HWI; KIM, IN HYE; AHN, JI HYEON; PARK, JOON HA; TAE, HYUN-JIN; CHO, GEUM-SIL; YAN, BING CHUN; KIM, DAE WON; HWANG, IN KOO; PARK, JINSEU; LEE, YUN LYUL; CHOI, SOO YOUNG; WON, MOO-HO

2015-01-01

Inhibitors of DNA-binding/differentiation (ID) proteins bind to basic helix-loop-helix (bHLH) transcription factors, including those that regulate differentiation and cell-cycle progression during development, and regulate gene transcription. However, little is known about the role of ID proteins in the brain under transient cerebral ischemic conditions. In the present study, we examined the effects of ischemia-reperfusion (I-R) injury on the immunoreactivity and protein levels of IDs 1–4 in the gerbil hippocampus proper Cornu Ammonis regions CA1–3 following 5 min of transient cerebral ischemia. Strong ID1 immunoreactivity was detected in the nuclei of pyramidal neurons in the hippocampal CA1–3 regions; immunoreactivity was significantly changed following I-R in the CA1 region, but not in the CA2/3 region. Five days following I-R, ID1 immunoreactivity was not detected in the CA1 pyramidal neurons. ID1 immunoreactivity was detected only in GABAergic interneurons in the ischemic CA1 region. Weak ID4 immunoreactivity was detected in non-pyramidal cells, and immunoreactivity was again only changed in the ischemic CA1 region. Five days following I-R, strong ID4 immunoreactivity was detected in non-pyramidal cells, which were identified as microglia, and not astrocytes, in the ischemic CA1 region. Furthermore, changes in the protein levels of ID1 and ID4 in the ischemic CA1 region studied by western blot were consistent with patterns of immunoreactivity. In summary, these results indicate that immunoreactivity and protein levels of ID1 and ID4 are distinctively altered following transient cerebral ischemia only in the CA1 region, and that the changes in ID1 and ID4 expression may relate to the ischemia-induced delayed neuronal death. PMID:25503067

Chandra X-ray constraints on the candidate Ca-rich gap transient SN 2016hnk

NASA Astrophysics Data System (ADS)

Sell, P. H.; Arur, K.; Maccarone, T. J.; Kotak, R.; Knigge, C.; Sand, D. J.; Valenti, S.

2018-03-01

We present a Chandra observation of SN 2016hnk, a candidate Ca-rich gap transient. This observation was specifically designed to test whether or not this transient was the result of the tidal detonation of a white dwarf by an intermediate-mass black hole. Since we detect no X-ray emission 28 d after the discovery of the transient, as predicted from fall-back accretion, we rule out this model. Our upper limit of ˜10 M⊙ does not allow us to rule out a neutron star or stellar-mass black hole detonator due limits on the sensitivity of Chandra to soft X-rays and unconstrained variables tied to the structure of super-Eddington accretion discs. Together with other Chandra and multiwavelength observations, our analysis strongly argues against the intermediate-mass black hole tidal detonation scenario for Ca-rich gap transients more generally.

Transient Phenomena: Opportunities for New Discoveries

NASA Technical Reports Server (NTRS)

Lazio, T. Joseph W.

2010-01-01

Known classes of radio wavelength transients range from the nearby (stellar flares and radio pulsars) to the distant Universe (gamma-ray burst afterglows). Hypothesized classes of radio transients include analogs of known objects, such as extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, such as prompt emission from gamma-ray bursts, evaporating black holes and transmitters from other civilizations. Time domain astronomy has been recognized internationally as a means of addressing key scientific questions in astronomy and physics, and pathfinders and Precursors to the Square Kilometre Array (SKA) are beginning to offer a combination of wider fields of view and more wavelength agility than has been possible in the past. These improvements will continue when the SKA itself becomes operational. I illustrate the range of transient phenomena and discuss how the detection and study of radio transients will improve immensely.

Transient classification in LIGO data using difference boosting neural network

NASA Astrophysics Data System (ADS)

Mukund, N.; Abraham, S.; Kandhasamy, S.; Mitra, S.; Philip, N. S.

2017-05-01

Detection and classification of transients in data from gravitational wave detectors are crucial for efficient searches for true astrophysical events and identification of noise sources. We present a hybrid method for classification of short duration transients seen in gravitational wave data using both supervised and unsupervised machine learning techniques. To train the classifiers, we use the relative wavelet energy and the corresponding entropy obtained by applying one-dimensional wavelet decomposition on the data. The prediction accuracy of the trained classifier on nine simulated classes of gravitational wave transients and also LIGO's sixth science run hardware injections are reported. Targeted searches for a couple of known classes of nonastrophysical signals in the first observational run of Advanced LIGO data are also presented. The ability to accurately identify transient classes using minimal training samples makes the proposed method a useful tool for LIGO detector characterization as well as searches for short duration gravitational wave signals.

Rule-Guided Executive Control of Response Inhibition: Functional Topography of the Inferior Frontal Cortex

PubMed Central

Cai, Weidong; Leung, Hoi-Chung

2011-01-01

Background The human inferior frontal cortex (IFC) is a large heterogeneous structure with distinct cytoarchitectonic subdivisions and fiber connections. It has been found involved in a wide range of executive control processes from target detection, rule retrieval to response control. Since these processes are often being studied separately, the functional organization of executive control processes within the IFC remains unclear. Methodology/Principal Findings We conducted an fMRI study to examine the activities of the subdivisions of IFC during the presentation of a task cue (rule retrieval) and during the performance of a stop-signal task (requiring response generation and inhibition) in comparison to a not-stop task (requiring response generation but not inhibition). We utilized a mixed event-related and block design to separate brain activity in correspondence to transient control processes from rule-related and sustained control processes. We found differentiation in control processes within the IFC. Our findings reveal that the bilateral ventral-posterior IFC/anterior insula are more active on both successful and unsuccessful stop trials relative to not-stop trials, suggesting their potential role in the early stage of stopping such as triggering the stop process. Direct countermanding seems to be outside of the IFC. In contrast, the dorsal-posterior IFC/inferior frontal junction (IFJ) showed transient activity in correspondence to the infrequent presentation of the stop signal in both tasks and the left anterior IFC showed differential activity in response to the task cues. The IFC subdivisions also exhibited similar but distinct patterns of functional connectivity during response control. Conclusions/Significance Our findings suggest that executive control processes are distributed across the IFC and that the different subdivisions of IFC may support different control operations through parallel cortico-cortical and cortico-striatal circuits. PMID:21673969

Cerebral High-Intensity Transient Signals during Pediatric Cardiac Catheterization: A Pilot Study Using Transcranial Doppler Ultrasonography.

PubMed

LaRovere, Kerri L; Kapur, Kush; McElhinney, Doff B; Razumovsky, Alexander; Kussman, Barry D

2017-07-01

Cerebral emboli are one potential cause of acute brain injury in children with congenital heart disease (CHD) undergoing cardiac catheterization. In this pilot study using transcranial Doppler (TCD) ultrasonography, we sought to evaluate the incidence, burden, and circumstances of cerebral high-intensity transient signals (HITS), presumably representing emboli, during pediatric cardiac catheterization. Emboli monitoring of the right middle cerebral artery was performed in five children. HITS, counted offline, were defined as unidirectional signals associated with audible "chirp" and sinusoidal correlation. HITS were grouped as single, >10 HITS ("cluster"), or HITS "with curtain effect" per 3-5 cardiac cycles. Cerebral blood flow velocity (CBFV) and pulsatility index (PI) were recorded after anesthetic induction (baseline). Total HITS in the cohort was 1,697 (790 single HITS, 606 HITS within clusters, and 301 HITS within curtains). HITS in clusters and curtains comprised 53% (907/1,697) of total HITS, and occurred in 44 clusters/curtains. Events associated with clusters/curtains included left ventricular angiography (39%; 17/44), right ventricular angiography (16%; 7/44), device placement (16%; 7/44), heparin bolus (9%; 4/44), pulmonary artery angiography (9%; 4/44), venous access (5%; 2/44), right atrial angiography (2%; 1/44), arterial access (2%; 1/44), and hemodynamic measurements (2%; 1/44). No patient had clinically detectable neurologic injury. HITS are common during pediatric cardiac catheterization, and associated with procedural factors. Whether curtains/clusters are worse than single, repetitive HITS is unknown. Larger studies are needed to determine whether HITS are a marker of risk of neurologic injury from emboli during pediatric cardiac catheterization. Copyright © 2017 by the American Society of Neuroimaging.

[Computerized interpretation of the electrocardiogram in the diagnosis of left ventricular hypertrophy. The ELECTROPRES project].

PubMed

Barrios, V; Calderón, A; Coca, A; González-Juanatey, J R; Sarríá, A; Rodríguez-Padial, L

2011-09-01

Despite its low sensitivity, the electrocardiogram (ECG) is the tool used the most in the daily practice for detection of left ventricular hypertrophy (LVH). This study has aimed to assess the impact of the computerized interpretation of the ECG on the diagnosis of LVH in the practical clinical setting. ELECTROPRES is a project based on a free access computer platform that permits an online interpretation of the electrocardiogram. It includes 19 different left LVH criteria previously validated by echocardiography in a substudy. We analyzed the data from the first 669 patients with essential arterial hypertension (ATH) included in the ELECTROPRES platform from 21 primary care centers in 9 of the 17 Spanish autonomous communities. Up to April 2010, a cohort of 669 hypertensive patients (51.7% women), with a mean age of 66.3±11.89 years, was analyzed. The mean evolution of the disease was 8 years, and the patients had been receiving an average of 2.4 antihypertensive agents. Systolic blood pressure was 139±17 mmHg and diastolic blood pressure 76±11. The ECG-known frequency of LVH was 3%. The prevalence of LVH increased up to 33.3% (P<0.001) with the ELECTROPRES platform. When all the criteria were independently examined, the Lewis index (R-I+S-III) and the Cornell product [(R-aVL+S-V3 (+6 for women)] were those in which the most cases of left ventricular hypertrophy were detected (24.8% and 13.3%, respectively). The Lewis index and the Cornell product were the criteria that detected more cases of left ventricular hypertrophy, regardless of the AHT stage and of the presence of cardiovascular complications. The ECG computerized reading (ELECTROPRES platform) significantly increases detection of left ventricular hypertrophy in a population of essential hypertense subjects compared to conventional detection with the ECG by the physician in the usual clinical practice setting. Copyright © 2011 Elsevier España, S.L. All rights reserved.

Continuous monitoring of regional function by a miniaturized ultrasound transducer allows early quantification of low-grade myocardial ischemia.

PubMed

Hyler, Stefan; Pischke, Søren E; Halvorsen, Per Steinar; Espinoza, Andreas; Bergsland, Jacob; Tønnessen, Tor Inge; Fosse, Erik; Skulstad, Helge

2015-04-01

Sensitive methods for the early detection of myocardial dysfunction are still needed, as ischemia is a leading cause of decreased ventricular function during and after heart surgery. The aim of this study was to test the hypothesis that low-grade ischemia could be detected quantitatively by a miniaturized epicardial ultrasound transducer (Ø = 3 mm), allowing continuous monitoring. In 10 pigs, transducers were positioned in the left anterior descending and circumflex coronary artery areas. Left ventricular pressure was obtained by a micromanometer. The left internal mammary artery was grafted to the left anterior descending coronary artery, which was occluded proximal to the anastomosis. Left internal mammary artery flow was stepwise reduced by 25%, 50%, and 75% for 18 min each. From the transducers, M-mode traces were obtained, allowing continuous tissue velocity traces and displacement measurements. Regional work was assessed as left ventricular pressure-displacement loop area. Tissue lactate measured from intramyocardial microdialysis was used as reference method to detect ischemia. All steps of coronary flow reduction demonstrated reduced peak systolic velocity (P < .05) and regional work (P < .01).The decreases in peak systolic velocity and regional work were closely related to the degree of ischemia, demonstrated by their correlations with lactate (R = -0.74, P < .01, and R = -0.64, P < .01, respectively). The circumflex coronary artery area was not affected by any of the interventions. The epicardially attached miniaturized ultrasound transducer allowed the precise detection of different levels of coronary flow reduction. The results also showed a quantitative and linear relationship among coronary flow, ischemia, and myocardial function. Thus, the ultrasound transducer has the potential to improve the monitoring of myocardial ischemia and to detect graft failure during and after heart surgery. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Functional and structural comparison of visual lateralization in birds – similar but still different

PubMed Central

Ströckens, Felix

2014-01-01

Vertebrate brains display physiological and anatomical left-right differences, which are related to hemispheric dominances for specific functions. Functional lateralizations likely rely on structural left-right differences in intra- and interhemispheric connectivity patterns that develop in tight gene-environment interactions. The visual systems of chickens and pigeons show that asymmetrical light stimulation during ontogeny induces a dominance of the left hemisphere for visuomotor control that is paralleled by projection asymmetries within the ascending visual pathways. But structural asymmetries vary essentially between both species concerning the affected pathway (thalamo- vs. tectofugal system), constancy of effects (transient vs. permanent), and the hemisphere receiving stronger bilateral input (right vs. left). These discrepancies suggest that at least two aspects of visual processes are influenced by asymmetric light stimulation: (1) visuomotor dominance develops within the ontogenetically stronger stimulated hemisphere but not necessarily in the one receiving stronger bottom-up input. As a secondary consequence of asymmetrical light experience, lateralized top-down mechanisms play a critical role in the emergence of hemispheric dominance. (2) Ontogenetic light experiences may affect the dominant use of left- and right-hemispheric strategies. Evidences from social and spatial cognition tasks indicate that chickens rely more on a right-hemispheric global strategy whereas pigeons display a dominance of the left hemisphere. Thus, behavioral asymmetries are linked to a stronger bilateral input to the right hemisphere in chickens but to the left one in pigeons. The degree of bilateral visual input may determine the dominant visual processing strategy when redundant encoding is possible. This analysis supports that environmental stimulation affects the balance between hemispheric-specific processing by lateralized interactions of bottom-up and top-down systems. PMID:24723898

Detection of ischemical dyssynchrony in patients with normal duration of QRS at rest and during exercise echocardiography (Dyssynchrony in coronary artery disease patients during exercise).

PubMed

Zagatina, A; Guseva, O; Bartosh-Zelenaya, S Y; Zhuravskaya, N

2014-04-01

Ischemic segments cannot develop a sufficient amount of strength during systole, so theoretically they begin to contract later in comparison with non-ischemic zones. There is a lack of information about methods that can detect dyssynchrony during exercise in patients with QRS not longer 100 ms. The aim of the study was to compare different methods of detection regarding left ventricular moving dyssynchrony in patients with significant coronary stenosis artery lesions: pulsed-wave of PW-TDI, strain (S) and strain rate (SR). The study included 133 subjects: 106 consecutive patients who were scheduled for coronary angiography with previous stress-echocardiography and 27 healthy persons. All the patients underwent a supine bicycle exercise test. Seventy-six patients had stenoses and 30 subjects had no significant lesions by coronary angiography. There was a detectable difference between time parameters of left ventricle contraction for the two groups and controls before and during exercise using all Doppler methods. Subgroups of patients without previous myocardial infarction and without hypertrophy of left ventricle had the same results. Maximal difference was observed using strain method. There was a moderate correlation between time parameters and the existence of significant lesions of coronary arteries. Patients without prolongations of QRS with significant lesions of coronary arteries have detectable left ventricular dyssynchrony before and during exercise.

Single Protein Structural Analysis with a Solid-state Nanopore Sensor

NASA Astrophysics Data System (ADS)

Li, Jiali; Golovchenko, Jene; McNabb, David

2005-03-01

We report on the use of solid-state nanopore sensors to detect single polypeptides. These solid-state nanopores are fabricated in thin membranes of silicon nitride by ion beam sculpting...[1]. When an electrically biased nanopore is exposed to denatured proteins in ionic solution, discrete transient electronic signals: current blockages are observed. We demonstrate examples of such transient electronic signals for Bovine Serum Albumin (BSA) and human placental laminin M proteins in Guanidine hydrochloride solution, which suggest that these polypeptides are individually translocating through the nanopore during the detecting process. The amplitude of the current blockages is proportional to the bias voltage. No transient current blockages are observed when proteins are not present in the solution. To probe protein-folding state, pH and temperature dependence experiments are performed. The results demonstrate a solid-state nanopore sensor can be used to detect and analyze single polypeptide chains. Similarities and differences with signals obtained from double stranded DNA in a solid-state nanopore and single stranded DNA in a biological nanopore are discussed. [.1] Li, J., D. Stein, C. McMullan, D. Branton, M.J. Aziz, and J.A. Golovchenko, Ion-beam sculpting at nanometre length scales. Nature, 2001. 412(12 July): p. 166-169.

A New Type of Transient High-Energy Source in the Direction of the Galactic Centre

NASA Technical Reports Server (NTRS)

Kouveliotou, C.; VanParadijs, J.; Fishman, G. J.; Briggs, M. S.; Kommers, J.; Harmon, B. A.; Meegan, C. A.; Lewin, W. H. G.

1996-01-01

Sources of high-energy (greater than 20 keV) bursts fall into two distinct types: the non-repeating gamma-ray bursters, several thousand of which have been detected but whose origin remains unknown, and the soft gamma-ray repeaters (SGRs), of which there are only three. The SGRs are known to be associated with supernova remnants, suggesting that the burst events most probably originate from young neutron stars. Here we report the detection of a third type of transient high-energy source. On 2 December 1995, we observed the onset of a sequence of hard X-ray bursts from a direction close to that of the Galactic Center. The interval between bursts was initially several minutes, but after two days, the burst rate had dropped to about one per hour and has been largely unchanged since then. More than 1,000 bursts have now been detected, with remarkably similar light curves and intensities; this behaviour is unprecendented among transient X-ray and gamma-ray sources. We suggest that the origin of these bursts might be related to the spasmodic accretion of material onto a neutron star.

Detection of intracardiac shunt flow in atrial septal defect using a real-time two-dimensional color-coded Doppler flow imaging system and comparison with contrast two-dimensional echocardiography.

PubMed

Suzuki, Y; Kambara, H; Kadota, K; Tamaki, S; Yamazato, A; Nohara, R; Osakada, G; Kawai, C

1985-08-01

To evaluate the noninvasive detection of shunt flow using a newly developed real-time 2-dimensional color-coded Doppler flow imaging system (D-2DE), 20 patients were examined, including 10 with secundum atrial septal defect (ASD) and 10 control subjects. These results were compared with contrast 2-dimensional echocardiography (C-2DE). Doppler 2DE displayed the blood flow toward the transducer as red and the blood flow away from the transducer as blue in 8 shades, each shade adding green according to the degree of variance in Doppler frequency. In the patients with ASD, D-2DE clearly visualized left-to-right shunt flow in 7 of 10 patients. In 5 of these 7 patients, C-2DE showed a negative contrast effect in the same area of the right atrium. Thus, D-2DE increased the sensitivity over C-2DE for detecting left-to-right shunt flow (from 50% to 70%). However, the specificity was slightly less in D-2DE (90%) than C-2DE (100%). Doppler 2DE could not visualize right-to-left shunt flow in all patients with ASD, though C-2DE showed a positive contrast effect in the left-sided heart in 9 of 10 patients with ASD. Thus, D-2DE is clinically useful for detecting left-to-right shunt flow in patients with ASD.

Development of a transient expression assay for detecting environmental oestrogens in zebrafish and medaka embryos

PubMed Central

2012-01-01

Background Oestrogenic contaminants are widespread in the aquatic environment and have been shown to induce adverse effects in both wildlife (most notably in fish) and humans, raising international concern. Available detecting and testing systems are limited in their capacity to elucidate oestrogen signalling pathways and physiological impacts. Here we developed a transient expression assay to investigate the effects of oestrogenic chemicals in fish early life stages and to identify target organs for oestrogenic effects. To enhance the response sensitivity to oestrogen, we adopted the use of multiple tandem oestrogen responsive elements (EREc38) in a Tol2 transposon mediated Gal4ff-UAS system. The plasmid constructed (pTol2_ERE-TATA-Gal4ff), contains three copies of oestrogen response elements (3ERE) that on exposure to oestrogen induces expression of Gal4ff which this in turn binds Gal4-responsive Upstream Activated Sequence (UAS) elements, driving the expression of a second reporter gene, EGFP (Enhanced Green Fluorescent Protein). Results The response of our construct to oestrogen exposure in zebrafish embryos was examined using a transient expression assay. The two plasmids were injected into 1–2 cell staged zebrafish embryos, and the embryos were exposed to various oestrogens including the natural steroid oestrogen 17ß-oestradiol (E2), the synthetic oestrogen 17α- ethinyloestradiol (EE2), and the relatively weak environmental oestrogen nonylphenol (NP), and GFP expression was examined in the subsequent embryos using fluorescent microscopy. There was no GFP expression detected in unexposed embryos, but specific and mosaic expression of GFP was detected in the liver, heart, somite muscle and some other tissue cells for exposures to steroid oestrogen treatments (EE2; 10 ng/L, E2; 100 ng/L, after 72 h exposures). For the NP exposures, GFP expression was observed at 10 μg NP/L after 72 h (100 μg NP/L was toxic to the fish). We also demonstrate that our construct works in medaka, another model fish test species, suggesting the transient assay is applicable for testing oestrogenic chemicals in fish generally. Conclusion Our results indicate that the transient expression assay system can be used as a rapid integrated testing system for environmental oestrogens and to detect the oestrogenic target sites in developing fish embryos. PMID:22726887

Advanced LIGO low-latency searches

NASA Astrophysics Data System (ADS)

Kanner, Jonah; LIGO Scientific Collaboration, Virgo Collaboration

2016-06-01

Advanced LIGO recently made the first detection of gravitational waves from merging binary black holes. The signal was first identified by a low-latency analysis, which identifies gravitational-wave transients within a few minutes of data collection. More generally, Advanced LIGO transients are sought with a suite of automated tools, which collectively identify events, evaluate statistical significance, estimate source position, and attempt to characterize source properties. This low-latency effort is enabling a broad multi-messenger approach to the science of compact object mergers and other transients. This talk will give an overview of the low-latency methodology and recent results.

Takotsubo cardiomyopathy: Pathophysiology, diagnosis and treatment

PubMed Central

Komamura, Kazuo; Fukui, Miho; Iwasaku, Toshihiro; Hirotani, Shinichi; Masuyama, Tohru

2014-01-01

In 1990, takotsubo cardiomyopathy (TCM) was first discovered and reported by a Japanese cardiovascular specialist. Since then, this heart disease has gained worldwide acceptance as an independent disease entity. TCM is an important entity that differs from acute myocardial infarction. It occurs more often in postmenopausal elderly women, is characterized by a transient hypokinesis of the left ventricular (LV) apex, and is associated with emotional or physical stress. Wall motion abnormality of the LV apex is generally transient and resolves within a few days to several weeks. Its prognosis is generally good. However, there are some reports of serious TCM complications, including hypotension, heart failure, ventricular rupture, thrombosis involving the LV apex, and torsade de pointes. It has been suggested that coronary spasm, coronary microvascular dysfunction, catecholamine toxicity and myocarditis might contribute to the pathogenesis of TCM. However, its pathophysiology is not clearly understood. PMID:25068020

Yard Sale

NASA Technical Reports Server (NTRS)

2006-01-01

17 July 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a bright plain west of Schiaparelli Crater, Mars, which is host to several features, some of them long-lived and others that are transient. The circular features scattered somewhat randomly throughout the scene are impact craters, all of which are in a variety of states of degradation. In the lower left (southwest) corner of the image, there is a small hill surrounded by ripples of windblown sediment, and near the center of the image, there is an active dust devil casting a shadow to the east as it makes its way across the plain.

Location near: 5.9oS, 348.2oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Autumn

"Occult cutaneous lymphangiectasis": an unusual case of cutaneous lymphangioma.

PubMed

Kakinuma, Hiroshi

2002-01-01

An unusual case of cutaneous lymphatic abnormality is described and named as "occult cutaneous lymphangietasis". A 26-year-old man had noticed pigmented maculae in the left inguinofemoral region and waist, which had gradually increased in number for as long as he could remember. The peculiar distribution of the eruptions and their transient saccular dilatation due to infection suggested that they were of lymphatic origin. Lymphangiography showed the presence of dilated lymphatics in the left inguinofemoral area and correspondence of the distribution of dermal backflow with the locations of the pigmented maculae. The histology is consistent with a diagnosis of lymphangioma. We could find no other reports of cases of cutaneous lymphangioma featuring pigmented maculae as the sole manifestation, although whether the pigmentation is an original clinical feature of this type of lymphatic abnormality is still an open question.

Tako-Tsubo cardiomyopathy presenting with cardiogenic shock successfully treated with milrinone: a case report.

PubMed

Doyen, Denis; Dellamonica, Jean; Moceri, Pamela; Moschietto, Sébastien; Hyvernat, Hervé; Ferrari, Emile; Bernardin, Gilles

2014-01-01

We report the case of a middle age patient presenting with Tako-Tsubo cardiomyopathy (TTC) complicated by cardiogenic shock that was successfully handled with milrinone. A 64-year old man presented with cardiogenic shock after benzodiazepine and alcohol intoxication. A slight elevation of troponin and typical left ventricular ballooning without coronary lesions suggested TTC. Within a few hours milrinone infusion normalized the cardiac index. TTC is responsible for severe transient left ventricular dysfunction occurring after physical or psychological stress. The major pathophysiological mechanism involved is disproportionate catecholamine secretion, which may stun the myocardium. We considered if treatment of this unique physiopathology with catecholamines could be dangerous in these patients and if alternative inotropes such as milrinone should be preferred. Copyright © 2014 The Authors. Published by Mosby, Inc. All rights reserved.

Timing and Targeting of Treatment in Left Ventricular Hypertrophy.

PubMed

Nam, Deokhwa; Reineke, Erin L

2017-01-01

In most clinical cases, left ventricular hypertrophy (LVH) occurs over time from persistent cardiac stress. At the molecular level, this results in both transient and long-term changes to metabolic, sarcomeric, ion handling, and stress signaling pathways. Although this is initially an adaptive change, the mechanisms underlying LVH eventually lead to maladaptive changes including fibrosis, decreased cardiac function, and failure. Understanding the regulators of long-term changes, which are largely driven by transcriptional remodeling, is a crucial step in identifying novel therapeutic targets for preventing the downstream negative effects of LVH and treatments that could reverse or prevent it. The development of effective therapeutics, however, will require a critical understanding of what to target, how to modify important pathways, and how to identify the stage of pathology in which a specific treatment should be used.

Cavernous hemangioma of the orbit: an unusual acute presentation

PubMed Central

Louisraj, Sophia; Ponnudurai, Thendral; Rodriguez, Dominic; Thomas, Philip A; Nelson Jesudasan, Christadoss Arul

2017-01-01

We report an unusual presentation of an orbital cavernous hemangioma in a 26-year-old female, who noted sudden redness and swelling of the left eye (LE) on waking up. At presentation, upper eyelid edema with periorbital ecchymosis and subconjunctival hemorrhage were noted in the LE. Although there was transient symptomatic relief with topical medications, blurring of vision developed in the LE. When seen 10 days later, the patient’s LE showed axial proptosis. Magnetic resonance imaging revealed an intraconal soft tissue mass in the superomedial quadrant of the left orbit. Superior orbitotomy with mass excision was done; histopathological examination of the excised mass revealed a cavernous hemangioma. The patient had complete visual recovery following surgery. To our knowledge, an acute presentation of an orbital cavernous hemangioma with subconjunctival hemorrhage and periorbital ecchymosis has not previously been reported. PMID:28769595

All-optical in-depth detection of the acoustic wave emitted by a single gold nanorod

NASA Astrophysics Data System (ADS)

Xu, Feng; Guillet, Yannick; Ravaine, Serge; Audoin, Bertrand

2018-04-01

A single gold nanorod dropped on the surface of a silica substrate is used as a transient optoacoustic source of gigahertz hypersounds. We demonstrate the all-optical detection of the as-generated acoustic wave front propagating in the silica substrate. For this purpose, time-resolved femtosecond pump-probe experiments are performed in a reflection configuration. The fundamental breathing mode of the nanorod is detected at 23 GHz by interferometry, and the longitudinal acoustic wave radiated in the silica substrate is detected by time-resolved Brillouin scattering. By tuning the optical probe wavelength from 750 to 900 nm, hypersounds with wavelengths of 260-315 nm are detected in the silica substrate, with corresponding acoustic frequencies in the range of 19-23 GHz. To confirm the origin of these hypersounds, we theoretically analyze the influence of the acoustic excitation spectrum on the temporal envelope of the transient reflectivity. This analysis proves that the acoustic wave detected in the silica substrate results from the excitation of the breathing mode of the nanorod. These results pave the way for performing local in-depth elastic nanoscopy.

Intracranial and visceral arterial embolization of a cardiac myxoma that was treated with endovascular stent-retriever therapy

PubMed Central

Thibodeau, Cheryl; McGowan, Amelia

2016-01-01

We report a case of a ruptured left atrial myxoma with multiple synchronous sites of embolization, including the intracranial cerebral (left middle cerebral artery (MCA) and basilar), visceral (renal, superior mesenteric artery (SMA)) and peripheral circulatory beds (aorta and lower extremities). This synchronous embolization resulted in a catastrophic neurologic and systemic event. An intracranial stent retriever was used to restore cerebral circulation in the symptomatic left MCA distribution, which resulted in resolution of the acute neurologic deficits. Endovascular and open surgical interventions were later performed to address the residual cardiac mass and other embolic sites. The patient survived the event with the loss of her right leg below the knee and a transient dialysis requirement. The purpose of this case report is to document the successful utilization of a stent-retriever device in removing an embolized myxoma from the cerebral circulation, to review the unique pathology of this source of embolic stroke and to reiterate the importance of considering embolic and non-thrombotic etiologies of acute ischemic stroke, especially in atypical patient populations and patient presentations. PMID:27306523

Contemporary review on the pathogenesis of takotsubo syndrome: The heart shedding tears: Norepinephrine churn and foam at the cardiac sympathetic nerve terminals.

PubMed

Y-Hassan, Shams; De Palma, Rodney

2017-02-01

Takotsubo syndrome (TS), an increasingly recognized acute cardiac disease entity, is characterized by a unique pattern of circumferential and typically regional left ventricular wall motion abnormality resulting in a conspicuous transient ballooning of the left ventricle during systole. The mechanism of the disease remains elusive. However, the sudden onset of acute myocardial stunning in a systematic pattern extending beyond a coronary artery territory; the history of a preceding emotional or physical stress factor in two thirds of cases; the signs of sympathetic denervation at the regions of left ventricular dysfunction on sympathetic scintigraphy; the finding of myocardial edema and other signs consistent with (catecholamine-induced) myocarditis shown by cardiac magnetic resonance imaging; and the contraction band necrosis on histopathological examination all argue strongly for the involvement of the cardiac sympathetic nervous system in the pathogenesis of TS. In this narrative review, extensive evidence in support of local cardiac sympathetic nerve hyperactivation, disruption and norepinephrine spillover causing TS in predisposed patients is provided. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Optical studies of the X-ray transient XTE J2123-058 - II. Phase-resolved spectroscopy

NASA Astrophysics Data System (ADS)

Hynes, R. I.; Charles, P. A.; Haswell, C. A.; Casares, J.; Zurita, C.; Serra-Ricart, M.

2001-06-01

We present time-resolved spectroscopy of the soft X-ray transient XTEJ2123-058 in outburst. A useful spectral coverage of 3700-6700Å was achieved spanning two orbits of the binary, with single-epoch coverage extending to ~9000Å. The optical spectrum approximates a steep blue power law, consistent with emission on the Rayleigh-Jeans tail of a hot blackbody spectrum. The strongest spectral lines are Heii 4686Å and Ciii/Niii 4640Å (Bowen blend) in emission. Their relative strengths suggest that XTEJ2123-058 was formed in the Galactic plane, not in the halo. Other weak emission lines of Heii and Civ are present, and Balmer lines show a complex structure, blended with Heii. Heii 4686-Å profiles show a complex multiple S-wave structure, with the strongest component appearing at low velocities in the lower-left quadrant of a Doppler tomogram. Hα shows transient absorption between phases 0.35 and 0.55. Both of these effects appear to be analogous to similar behaviour in SW Sex type cataclysmic variables. We therefore consider whether the spectral line behaviour of XTEJ2123-058 can be explained by the same models invoked for those systems.

Transient peripartum osteoporosis of the femoral head in first and third pregnancy.

PubMed

Truszczyńska, Aleksandra; Walczak, Piotr; Rapała, Kazimierz

2012-01-01

The aim of this article was to present transient peripartum femoral head osteoporosis. This very rare condition occurred twice in our patient-a woman in her 30s. The cases described in the literature were mostly unilateral, with bilateral hip involvement noted much less frequently. In our patient, transient osteoporosis occurred in the third trimester of her first pregnancy in the right hip, her second pregnancy was uncomplicated, and in the third trimester of the patient's third pregnancy, osteoporotic changes were noted in the left hip joint. The patient breastfed her first and third babies only 3 wk each. She breastfed her second baby for 4 mo. The diagnostic workup was based on the clinical examination and radiographic/magnetic resonance imaging, which revealed bone marrow edema, and the dual-energy X-ray absorptiometry scans. The treatment consisted in core decompression of the femoral head (foragé), unloading of the hip using crutches as well as administration of calcitonin and calcium supplements. Complete recovery of the femoral heads was achieved. The follow-up time was 7 yr. Copyright © 2012 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Experimental Study of Fluid Structure Interaction Effects on Metal Plates Under Fully Developed Laminar Flow

DTIC Science & Technology

2011-12-01

UU NSN 7540–01–280–5500 Standard Form 298 (Rev. 8–98) Prescribed by ANSI Std. Z39.18 ii THIS PAGE INTENTIONALLY LEFT BLANK iii Approved for...modeled using the finite element analysis simulation code, ANSYS 13.0. The main objective of these simulations was to determine the location at which...transient response of the test plate under FSI conditions, computational studies were carried out in ANSYS 13.0 Multi-field (MFX) simulation

Ergotamine-Induced Takotsubo Cardiomyopathy.

PubMed

Ozpelit, Ebru; Ozpelit, Mehmet E; Akdeniz, Bahri; Göldeli, Özhan

2016-01-01

Takotsubo cardiomyopathy (TC) is a recently increasing diagnosed disease showed by transient apical or mid-apical left ventricular dysfunction. It is known as a disease of postmenopausal women, which is usually triggered by emotional or physical stress. Although the trigger is mostly endogenous, some drugs have also been reported as the cause. Published case reports of TC associated with drug usage consist of sympathomimetic drugs, inotropic agents, thyroid hormone, cocaine, and 5-fluorouracil. We present an unusual case of TC in which the possible trigger is ergotamine toxicity.

New methods to constrain the radio transient rate: results from a survey of four fields with LOFAR.

PubMed

Carbone, D; van der Horst, A J; Wijers, R A M J; Swinbank, J D; Rowlinson, A; Broderick, J W; Cendes, Y N; Stewart, A J; Bell, M E; Breton, R P; Corbel, S; Eislöffel, J; Fender, R P; Grießmeier, J-M; Hessels, J W T; Jonker, P; Kramer, M; Law, C J; Miller-Jones, J C A; Pietka, M; Scheers, L H A; Stappers, B W; van Leeuwen, J; Wijnands, R; Wise, M; Zarka, P

2016-07-01

We report on the results of a search for radio transients between 115 and 190 MHz with the LOw-Frequency ARray (LOFAR). Four fields have been monitored with cadences between 15 min and several months. A total of 151 images were obtained, giving a total survey area of 2275 deg 2 . We analysed our data using standard LOFAR tools and searched for radio transients using the LOFAR Transients Pipeline. No credible radio transient candidate has been detected; however, we are able to set upper limits on the surface density of radio transient sources at low radio frequencies. We also show that low-frequency radio surveys are more sensitive to steep-spectrum coherent transient sources than GHz radio surveys. We used two new statistical methods to determine the upper limits on the transient surface density. One is free of assumptions on the flux distribution of the sources, while the other assumes a power-law distribution in flux and sets more stringent constraints on the transient surface density. Both of these methods provide better constraints than the approach used in previous works. The best value for the upper limit we can set for the transient surface density, using the method assuming a power-law flux distribution, is 1.3 × 10 -3  deg -2 for transients brighter than 0.3 Jy with a time-scale of 15 min, at a frequency of 150 MHz. We also calculated for the first time upper limits for the transient surface density for transients of different time-scales. We find that the results can differ by orders of magnitude from previously reported, simplified estimates.

Fallopian Tube Herniation through Left Sided Abdominal Drain Site.

PubMed

Hussain, Khalid; Masood, Jovaria

2016-06-01

Intra-abdominal drains have been used since long to prevent intra-abdominal collection, and detect any anastomotic leaks. We report a case of left sided fallopian tube herniation from a left lower abdominal drain site in a 27-year female who underwent caesarian section for breach presentation. Several complications related to drain usage has been described but left sided fallopian tube prolapse through drain site has not been reported in literature.

Left Atrial 4D Blood Flow Dynamics and Hemostasis following Electrical Cardioversion of Atrial Fibrillation.

PubMed

Cibis, Merih; Lindahl, Tomas L; Ebbers, Tino; Karlsson, Lars O; Carlhäll, Carl-Johan

2017-01-01

Background: Electrical cardioversion in patients with atrial fibrillation is followed by a transiently impaired atrial mechanical function, termed atrial stunning. During atrial stunning, a retained risk of left atrial thrombus formation exists, which may be attributed to abnormal left atrial blood flow patterns. 4D Flow cardiovascular magnetic resonance (CMR) enables blood flow assessment from the entire three-dimensional atrial volume throughout the cardiac cycle. We sought to investigate left atrial 4D blood flow patterns and hemostasis during left atrial stunning and after left atrial mechanical function was restored. Methods: 4D Flow and morphological CMR data as well as blood samples were collected in fourteen patients at two time-points: 2-3 h (Time-1) and 4 weeks (Time-2) following cardioversion. The volume of blood stasis and duration of blood stasis were calculated. In addition, hemostasis markers were analyzed. Results: From Time-1 to Time-2: Heart rate decreased (61 ± 7 vs. 56 ± 8 bpm, p = 0.01); Maximum change in left atrial volume increased (8 ± 4 vs. 22 ± 15%, p = 0.009); The duration of stasis (68 ± 11 vs. 57 ± 8%, p = 0.002) and the volume of stasis (14 ± 9 vs. 9 ± 7%, p = 0.04) decreased; Thrombin-antithrombin complex (TAT) decreased (5.2 ± 3.3 vs. 3.3 ± 2.2 μg/L, p = 0.008). A significant correlation was found between TAT and the volume of stasis ( r 2 = 0.69, p < 0.001) at Time-1 and between TAT and the duration of stasis ( r 2 = 0.34, p = 0.04) at Time-2. Conclusion: In this longitudinal study, left atrial multidimensional blood flow was altered and blood stasis was elevated during left atrial stunning compared to the restored left atrial mechanical function. The coagulability of blood was also elevated during atrial stunning. The association between blood stasis and hypercoagulability proposes that assessment of left atrial 4D flow can add to the pathophysiological understanding of thrombus formation during atrial fibrillation related atrial stunning.

Left atrium by echocardiography in clinical practice: from conventional methods to new echocardiographic techniques.

PubMed

Ancona, Roberta; Comenale Pinto, Salvatore; Caso, Pio; D'Andrea, Antonello; Di Salvo, Giovanni; Arenga, Fortunato; Coppola, Maria Gabriella; Sellitto, Vincenzo; Macrino, Maria; Calabrò, Raffaele

2014-01-01

Although often referred to as "the forgotten chamber", compared with left ventricle (LV), especially in the past years, the left atrium (LA) plays a critical role in the clinical expression and prognosis of patients with heart and cerebrovascular disease, as demonstrated by several studies. Echocardiographers initially focused on early detection of atrial geometrical abnormalities through monodimensional atrial diameter quantification and then bidimensional (2D) areas and volume estimation. Now, together with conventional echocardiographic parameters, new echocardiographic techniques, such as strain Doppler, 2D speckle tracking and three-dimensional (3D) echocardiography, allow assessing early LA dysfunction and they all play a fundamental role to detect early functional remodelling before anatomical alterations occur. LA dysfunction and its important prognostic implications may be detected sooner by LA strain than by volumetric measurements.

Effects of propranolol treatment on left ventricular function and intracellular calcium regulation in rats with postinfarction heart failure

PubMed Central

Litwin, Sheldon E; Katz, Sarah E; Morgan, James P; Douglas, Pamela S

1999-01-01

Chronic treatment with beta-adrenergic blocking agents can improve survival in patients with heart failure. The mechanisms underlying the beneficial effects and whether these effects are generalizable to ischaemic heart failure are unresolved.We performed echocardiographic-Doppler examinations in rats (n=28) 1 and 6 weeks after myocardial infarction (MI) or sham surgery. Rats were randomized to no treatment or propranolol (500 mg/l in drinking water) after the first echocardiogram. Isometric contractions and intracellular Ca transients were recorded simultaneously in noninfarcted left ventricular (LV) papillary muscles.Untreated MI rats had significant LV dilatation (10.6±0.4* vs 8.9±0.3 mm, MI vs control), impaired systolic function (fractional shortening=11±2* vs 38±2%), and a restrictive LV diastolic filling pattern. MI rats receiving propranolol had similar LV chamber sizes (10.6±0.5 mm) and systolic function (13±2%). The propranolol treated animals had higher LV end-diastolic pressures (27±2* vs 20±3 mmHg) and a more restricted LV diastolic filling pattern (increased ratio of early to late filling velocities and more rapid E wave deceleration rate). Contractility of papillary muscles from untreated MI rats was depressed (1.6±0.3 vs 2.4±0.5 g mm−2). In addition, Ca transients were prolonged and the inotropic response to isoproterenol was blunted. Propranolol treatment did not improve force development (1.6±0.3 g mm−2) or the duration of Ca transients during isoproterenol stimulation.Chronic propranolol treatment in rats with postinfarction heart failure did not improve LV remodeling or systolic function. LV diastolic pressures and filling patterns were worsened by propranolol. Treatment also did not produce appreciable improvement in contractility, intracellular Ca regulation or beta-adrenergic responsiveness in the noninfarcted myocardium. PMID:10455325

The Transient Receptor Potential Vanilloid 2 Cation Channel Is Abundant in Macrophages Accumulating at the Peri-Infarct Zone and May Enhance Their Migration Capacity towards Injured Cardiomyocytes following Myocardial Infarction

PubMed Central

Goryainov, Pavel; Landa, Natalie; Barshack, Iris; Avivi, Camila; Semo, Jonathan; Keren, Gad

2014-01-01

Purpose A novel family of transient receptor potential (TRP) channels, that may hold a role in calcium homeostasis, has recently been described. By employing a GeneChip array analysis we have demonstrated a clear and specific upregulation of the TRP vanilloid 2 (TRPV2) mRNA in the left ventricles (LV) 3–5 days post-acute myocardial infarction (MI) compared to sham-operated controls, both in rats and in mice. We sought to characterize the cardiac cellular subpopulations in which TRPV2 is overexpressed upon acute MI. Methods Lewis rats underwent an acute MI by ligation of the left anterior descending artery or chest opening only (sham). The animals were terminated at various time points and an immunohistochemical (IHC) and immunofloerescent (IFC) staining of the LV sections as well as a flow cytometry analysis of LV-derived cells were carried out, using anti-TRPV2 and anti-monocyte/macrophage antibodies. Rat alveolar macrophage cells, NR8383, transiently transfected with TRPV2 siRNA were allowed to migrate towards hypoxic conditioned media of the rat cardiac myoblast line H9C2 using a trans-well migration assay. The macrophage cells migrating to the bottom side of the inserts were counted. Results The IHC and IFC staining as well as the flow cytometry data demonstrated a substantial expression of TRPV2 in infiltrating macrophages in the peri-infarct region 3–5 days post-acute MI. The in vitro migration assay data demonstrated that following inhibition of the TRPV2 channel, the number of migrating macrophages towards conditioned medium of hypoxic cardiomyocytes was significantly reduced. Conclusions TRPV2 is highly expressed on the peri-infarct infiltrating macrophages and may play an important role in post-MI phagocytosis. Better characterization of this channel may pave the way for identifying a new target for modulating the dramatic post-MI immune reactions. PMID:25136832

Very bright optical transient near the Trifid and Lagoon Nebulae

NASA Astrophysics Data System (ADS)

Dunsby, Peter

2018-03-01

Peter Dunsby (University of Cape Town) reports the detection of a very bright optical transient in the region between the Lagoon and Trifid Nebulae based on observations obtained from Cape Town on 20 March 2018, between 01:00 and 03:45 UT. The object was visible throughout the full duration of the observations and not seen when this field was observed previously (08 March 2018).

High energy transients: The millisecond domain

NASA Astrophysics Data System (ADS)

Rao, A. R.

2018-02-01

The search for high energy transients in the millisecond domain has come to the focus in recent times due to the detection of gravitational wave events and the identification of fast radio bursts as cosmological sources. Here we highlight the sensitivity limitations in the currently operating hard X-ray telescopes and give some details of the search for millisecond events in the AstroSat CZT Imager data.

Left-right compatibility in the processing of trading verbs.

PubMed

Vicario, Carmelo M; Rumiati, Raffaella I

2014-01-01

The research investigating the nature of cognitive processes involved in the representation of economical outcomes is growing. Within this research, the mental accounting model proposes that individuals may well use cognitive operations to organize, evaluate, and keep track of their financial activities (Thaler, 1999). Here we wanted to test this hypothesis by asking to a group of participants to detect a syntax mistake of verbs indicating incoming and going out activities related to economical profit (trading verbs), swapping (swapping verbs) and thinking (thinking verbs). We reported a left-right compatibility for trading verbs (i.e., participants were faster with their right hand while detecting verb referring to a monetary gain with respect to a monetary loss; and faster with their left hand while detecting a monetary loss with respect to a monetary gain). However, this pattern of result was not reported while detecting swapping verbs. Results are discussed taking into account the mental accounting theory as well as to the spatial mapping of valence hypothesis.

The distributed neural system for top-down letter processing: an fMRI study

NASA Astrophysics Data System (ADS)

Liu, Jiangang; Feng, Lu; Li, Ling; Tian, Jie

2011-03-01

This fMRI study used Psychophysiological interaction (PPI) to investigate top-down letter processing with an illusory letter detection task. After an initial training that became increasingly difficult, participant was instructed to detect a letter from pure noise images where there was actually no letter. Such experimental paradigm allowed for isolating top-down components of letter processing and minimizing the influence of bottom-up perceptual input. A distributed cortical network of top-down letter processing was identified by analyzing the functional connectivity patterns of letter-preferential area (LA) within the left fusiform gyrus. Such network extends from the visual cortex to high level cognitive cortexes, including the left middle frontal gyrus, left medial frontal gyrus, left superior parietal gyrus, bilateral precuneus, and left inferior occipital gyrus. These findings suggest that top-down letter processing contains not only regions for processing of letter phonology and appearance, but also those involved in internal information generation and maintenance, and attention and memory processing.

The MWA Transients Survey (MWATS).

NASA Astrophysics Data System (ADS)

Bell, M.; Murphy, T.; Kaplan, D. L.; Croft, S. D.; Hancock, P.; Rowlinson, A.; Wayth, R.; Gaensler, B.; Hurley-Walker, N.; Offringa, A.; Loi, C.; Bannister, K.; Trott, C.; Marquart, J.

2017-01-01

We propose the continuation of the MWA transients survey to search for and monitor low frequency transient and variable radio sources in the southern sky. This proposal is aimed at commensally utilising data from the GLEAM-X (G0008) project in semester 2017-A. The aim of this commensal data acquisition is to commission long baseline observations for transient science. In particular this will involve studying the impact of the ionosphere on calibration and imaging, and developing the techniques needed to produce science quality data products. The proposed drift scans with LST locking (see G0008 proposal) are particularly exciting as we can test image subtraction for transient and variable identification. This survey is targeted at studying objects such as AGN (intrinsic and extrinsic variability), long duration synchrotron emitters, pulsars and transients of unknown origin. The maps generated from this survey will be analysed with the Variables and Slow Transients (VAST) detection pipeline. The motivation for this survey is as follows: (i) To obtain temporal data on an extremely large and robust sample of low frequency sources to explore and quantify both intrinsic and extrinsic variability; (ii) To search and find new classes of low frequency radio transients that previously remained undetected and obscured from multi-wavelength discovery; (iii) To place rigorous statistics on the occurrence of both transients and variables prior to the Australian SKA era.

Searching for MHz Transients with the VLA Low-band Ionosphere and Transient Experiment (VLITE)

NASA Astrophysics Data System (ADS)

Polisensky, Emil; Peters, Wendy; Giacintucci, Simona; Clarke, Tracy; Kassim, Namir E.; hyman, Scott D.; van der Horst, Alexander; Linford, Justin; Waldron, Zach; Frail, Dale

2018-01-01

NRL and NRAO have expanded the low frequency capabilities of the VLA through the VLA Low-band Ionosphere and Transient Experiment (VLITE, http://vlite.nrao.edu/ ), effectively making the instrument two telescopes in one. VLITE is a commensal observing system that harvests data from the prime focus in parallel with normal Cassegrain focus observing on a subset of VLA antennas. VLITE provides over 6000 observing hours per year in a > 5 square degree field-of-view using 64 MHz bandwidth centered on 352 MHz. By operating in parallel, VLITE offers invaluable low frequency data to targeted observations of transient sources detected at higher frequencies. With arcsec resolution and mJy sensitivity, VLITE additionally offers great potential for blind searches of rarer radio-selected transients. We use catalog matching software on the imaging products from the daily astrophysics pipeline and the LOFAR Transients Pipeline (TraP) on repeated observations of the same fields to search for coherent and incoherent astronomical transients on timescales of a few seconds to years. We present the current status of the VLITE transient science program from its initial deployment on 10 antennas in November 2014 through its expansion to 16 antennas in the summer of 2017. Transient limits from VLITE’s first year of operation (Polisensky et al. 2016) are updated per the most recent analysis.

Colonoscopy can miss diverticula of the left colon identified by barium enema.

PubMed

Niikura, Ryota; Nagata, Naoyoshi; Shimbo, Takuro; Akiyama, Junichi; Uemura, Naomi

2013-04-21

To identify the diagnostic value of colonoscopy for diverticulosis as determined by barium enema. A total of 65 patients with hematochezia who underwent colonoscopy and barium enema were analyzed, and the diagnostic value of colonoscopy for diverticula was assessed. The receiver operating characteristic area under the curve was compared in relation to age (< 70 or ≥ 70 years), sex, and colon location. The number of diverticula was counted, and the detection ratio was calculated. Colonic diverticula were observed in 46 patients with barium enema. Colonoscopy had a sensitivity of 91% and specificity of 90%. No significant differences were found in the receiver operating characteristic area under the curve (ROC-AUC) for age group or sex. The ROC-AUC of the left colon was significantly lower than that of the right colon (0.81 vs 0.96, P = 0.02). Colonoscopy identified 486 colonic diverticula, while barium enema identified 1186. The detection ratio for the entire colon was therefore 0.41 (486/1186). The detection ratio in the left colon (0.32, 189/588) was significantly lower than that of the right colon (0.50, 297/598) (P < 0.01). Compared with barium enema, only half the number of colonic diverticula can be detected by colonoscopy in the entire colon and even less in the left colon.

Study of X-ray transients with Scanning Sky Monitor (SSM) onboard AstroSat

NASA Astrophysics Data System (ADS)

Ramadevi, M. C.; Ravishankar, B. T.; Sarwade, Abhilash R.; Vaishali, S.; Iyer, Nirmal Kumar; Nandi, Anuj; Girish, V.; Agarwal, Vivek Kumar; Baby, Blessy Elizabeth; Hasan, Mohammed; Seetha, S.; Bhattacharya, Dipankar

2018-02-01

Scanning Sky Monitor (SSM) onboard AstroSat is an X-ray sky monitor in the energy range 2.5-10 keV. SSM scans the sky for X-ray transient sources in this energy range of interest. If an X-ray transient source is detected in outburst by SSM, the information will be provided to the astronomical community for follow-up observations to do a detailed study of the source in various other bands. SSM instrument, since its power-ON in orbit, has observed a number of X-ray sources. This paper discusses observations of few X-ray transients by SSM. The flux reported by SSM for few sources during its Performance Verification phase (PV phase) is studied and the results are discussed.

Outflow-driven Transients from the Birth of Binary Black Holes. II. Primary-induced Accretion Transients

NASA Astrophysics Data System (ADS)

Kimura, Shigeo S.; Murase, Kohta; Mészáros, Peter

2017-12-01

We discuss the electromagnetic radiation from newborn binary black holes (BBHs). As a consequence of the evolution of massive stellar binaries, a binary consisting of a primary black hole (BH) and a secondary Wolf–Rayet star is expected as a BBH progenitor system. We investigate optical transients from the birth of BBHs powered by the Bondi–Hoyle–Lyttleton accretion onto the primary BH, which occur ∼1–10 Gyr earlier than gravitational-wave signals at the BH–BH merger. When the secondary massive star collapses into a BH, it may eject a fraction of its outer material and may form a disk around the primary BH and induces a powerful disk wind. These primary-induced winds can lead to optical transients with a kinetic energy of ∼1047–3 × 1048 erg, an ejecta velocity of 108–109 cm s‑1, a duration of a few days, and an absolute magnitude ranging from about ‑11 to ‑14. The light curves and late-time spectra of these transients are distinctive from those of ordinary supernovae, and detection of this type of transient is possible by future optical transient surveys if the event rate of this transient is comparable to the merger rate of BBHs. This paper focuses on the emissions from disk-driven transients induced by the primary BH, different from Paper I, which focuses on wind-driven transients from the tidally locked secondary massive star.

One nuclear calcium transient induced by a single burst of action potentials represents the minimum signal strength in activity-dependent transcription in hippocampal neurons.

PubMed

Yu, Yan; Oberlaender, Kristin; Bengtson, C Peter; Bading, Hilmar

2017-07-01

Neurons undergo dramatic changes in their gene expression profiles in response to synaptic stimulation. The coupling of neuronal excitation to gene transcription is well studied and is mediated by signaling pathways activated by cytoplasmic and nuclear calcium transients. Despite this, the minimum synaptic activity required to induce gene expression remains unknown. To address this, we used cultured hippocampal neurons and cellular compartment analysis of temporal activity by fluorescence in situ hybridization (catFISH) that allows detection of nascent transcripts in the cell nucleus. We found that a single burst of action potentials, consisting of 24.4±5.1 action potentials during a 6.7±1.9s depolarization of 19.5±2.0mV causing a 9.3±0.9s somatic calcium transient, is sufficient to activate transcription of the immediate early gene arc (also known as Arg3.1). The total arc mRNA yield produced after a single burst-induced nuclear calcium transient was very small and, compared to unstimulated control neurons, did not lead to a significant increase in arc mRNA levels measured using quantitative reverse transcriptase PCR (qRT-PCR) of cell lysates. Significantly increased arc mRNA levels became detectable in hippocampal neurons that had undergone 5-8 consecutive burst-induced nuclear calcium transients at 0.05-0.15Hz. These results indicate that a single burst-induced nuclear calcium transient can activate gene expression and that transcription is rapidly shut off after synaptic stimulation has ceased. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flexible echolocation behavior of trawling bats during approach of continuous or transient prey cues

PubMed Central

Übernickel, Kirstin; Tschapka, Marco; Kalko, Elisabeth K. V.

2013-01-01

Trawling bats use echolocation not only to detect and classify acoustically continuous cues originated from insects at and above water surfaces, but also to detect small water-dwelling prey items breaking the water surface for a very short time, producing only transient cues to be perceived acoustically. Generally, bats need to adjust their echolocation behavior to the specific task on hand, and because of the diversity of prey cues they use in hunting, trawling bats should be highly flexible in their echolocation behavior. We studied the adaptations in the behavior of Noctilio leporinus when approaching either a continuous cue or a transient cue that disappeared during the approach of the bat. Normally the bats reacted by dipping their feet in the water at the cue location. We found that the bats typically started to adapt their calling behavior at approximately 410 ms before prey contact in continuous cue trials, but were also able to adapt their approach behavior to stimuli onsets as short as 177 ms before contact, within a minimum reaction time of 50.9 ms in response to transient cues. In both tasks the approach phase ended between 32 and 53 ms before prey contact. Call emission always continued after the end of the approach phase until around prey contact. In some failed capture attempts, call emission did not cease at all after prey contact. Probably bats used spatial memory to dip at the original location of the transient cue after its disappearance. The duration of the pointed dips was significantly longer in transient cue trials than in continuous cue trials. Our results suggest that trawling bats possess the ability to modify their generally rather stereotyped echolocation behavior during approaches within very short reaction times depending on the sensory information available. PMID:23675352

Test of the Weak Equivalence Principle using LIGO observations of GW150914 and Fermi observations of GBM transient 150914

NASA Astrophysics Data System (ADS)

Liu, Molin; Zhao, Zonghua; You, Xiaohe; Lu, Jianbo; Xu, Lixin

2017-07-01

About 0.4 s after the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a transient gravitational-wave (GW) signal GW150914, the Fermi Gamma-ray Burst Monitor (GBM) also found a weak electromagnetic transient (GBM transient 150914). Time and location coincidences favor a possible association between GW150904 and GBM transient 150914. Under this possible association, we adopt Fermi's electromagnetic (EM) localization and derive constraints on possible violations of the Weak Equivalence Principle (WEP) from the observations of two events. Our calculations are based on four comparisons: (1) The first is the comparison of the initial GWs detected at the two LIGO sites. From the different polarizations of these initial GWs, we obtain a limit on any difference in the parametrized post-Newtonian (PPN) parameter Δγ ≲10-10. (2) The second is a comparison of GWs and possible EM waves. Using a traditional super-Eddington accretion model for GBM transient 150914, we again obtain an upper limit Δγ ≲10-10. Compared with previous results for photons and neutrinos, our limits are five orders of magnitude stronger than those from PeV neutrinos in blazar flares, and seven orders stronger than those from MeV neutrinos in SN1987A. (3) The third is a comparison of GWs with different frequencies in the range [35 Hz, 250 Hz]. (4) The fourth is a comparison of EM waves with different energies in the range [1 keV, 10 MeV]. These last two comparisons lead to an even stronger limit, Δγ ≲10-8. Our results highlight the potential of multi-messenger signals exploiting different emission channels to strengthen existing tests of the WEP.

Characterizing the recovery of a solid surface after tungsten nano-tendril formation

NASA Astrophysics Data System (ADS)

Wright, G. M.; van Eden, G. G.; Kesler, L. A.; De Temmerman, G.; Whyte, D. G.; Woller, K. B.

2015-08-01

Recovery of a flat tungsten surface from a nano-tendril surface is attempted through three techniques; a mechanical wipe, a 1673 K annealing, and laser-induced thermal transients. Results were determined through SEM imaging and elastic recoil detection to assess the helium content in the surface. The mechanical wipe leaves a ∼0.5 μm deep layer of nano-tendrils on the surface post-wipe regardless of the initial nano-tendril layer depth. Laser-induced thermal transients only significantly impact the surface morphology at heat loads of 35.2 MJ/m2 s1/2 or above, however a fully flat or recovered surface was not achieved for 100 transients at this heat load despite reducing the helium content by a factor of ∼7. A 1673 K annealing removes all detectable levels of helium but sub-surface voids/bubbles remain intact. The surface is recovered to a nearly flat state with only some remnants of nano-tendrils re-integrating into the surface remaining.

The Swift-BAT Hard X-ray Transient Monitor

NASA Technical Reports Server (NTRS)

Krimm, Hans; Markwardt, C. B.; Sanwal, D.; Tueller, J.

2006-01-01

The Burst Alert Telescope (BAT) on the Swift satellite is a large field of view instrument that continually monitors the sky to provide the gamma-ray burst trigger for Swift. An average of more than 70% of the sky is observed on a daily basis. The survey mode data is processed on two sets on time scales: from one minute to one day as part of the transient monitor program, and from one spacecraft pointing (approx.20 minutes) to the full mission duration for the hard X-ray survey program. The transient monitor has recently become public through the web site http:// swift.gsfc.nasa.gov/docs/swift/results/transients/. Sky images are processed to detect astrophysical sources in the 15-50 keV energy band and the detected flux or upper limit is calculated for >100 sources on time scales up to one day. Light curves are updated each time that new BAT data becomes available (approx.10 times daily). In addition, the monitor is sensitive to an outburst from a new or unknown source. Sensitivity as a function of time scale for catalog and unknown sources will be presented. The daily exposure for a typical source is approx.1500-3000 seconds, with a 1-sigma sensitivity of approx.4 mCrab. 90% of the sources are sampled at least every 16 days, but many sources are sampled daily. It is expected that the Swift-BAT transient monitor will become an important resource for the high energy astrophysics community.

IMPLICATIONS OF THE TENTATIVE ASSOCIATION BETWEEN GW150914 AND A FERMI -GBM TRANSIENT

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

Li, Xiang; Yuan, Qiang; Jin, Zhi-Ping

2016-08-10

The merger-driven gamma-ray bursts (GRBs) and their associated gravitational-wave (GW) radiation, if both are successfully detected, have some far-reaching implications, including, for instance: (i) the statistical comparison of the physical properties of the short/long-short GRBs with and without GW detection can test the general origin model; (ii) revealing the physical processes taking place at the central engine; (iii) measuring the velocity of the gravitational wave directly/accurately. In this work, we discuss these implications in the case of a possible association of GW150914/Gamma-ray Burst Monitor (GBM) transient 150914. We compared GBM transient 150914 with other SGRBs and found that such anmore » event may be a distinct outlier in some statistical diagrams, possibly due to its specific binary black hole merger origin. However, the presence of a “new” group of SGRBs with “unusual” physical parameters is also possible. If the outflow of GBM transient 150914 was launched by the accretion onto the nascent black hole, the magnetic activity rather than the neutrino process is likely responsible for the energy extraction, and the accretion disk mass is estimated to be ∼10{sup −5} M {sub ⊙}. The GW150914/GBM transient 150914 association, if confirmed, would provide the first opportunity to directly measure the GW velocity, and its departure from the speed of the light should be within a factor of ∼10{sup −17}.« less

Swift-BAT: Transient Source Monitoring

NASA Astrophysics Data System (ADS)

Barbier, L. M.; Barthelmy, S.; Cummings, J.; Gehrels, N.; Krimm, H.; Markwardt, C.; Mushotzky, R.; Parsons, A.; Sakamoto, T.; Tueller, J.; Fenimore, E.; Palmer, D.; Skinner, G.; Swift-BAT Team

2005-12-01

The Burst Alert Telescope (BAT) on the Swift satellite is a large field of view instrument that continually monitors the sky to provide the gamma-ray burst trigger for Swift. An average of more than 70% of the sky is observed on a daily basis. The survey mode data is processed on two sets of time scales: from one minute to one day as part of the transient monitor program, and from one spacecraft pointing ( ˜20 minutes) to the full mission duration for the hard X-ray survey program. In the transient monitor program, sky images are processed to detect astrophysical sources in six energy bands covering 15-350 keV. The detected flux or upper limit in each energy band is calculated for >300 objects on time scales up to one day. In addition, the monitor is sensitive to an outburst from a new or unknown source. Sensitivity as a function of time scale for catalog and unknown sources will be presented. The daily exposure for a typical source is ˜1500 - 3000 seconds, with a 1-sigma sensitivity of ˜4mCrab. 90% of the sources are sampled at least every 16 days, but many sources are sampled daily. The BAT team will soon make the results of the transient monitor public to the astrophysical community through the Swift mission web page. It is expected that the Swift-BAT transient monitor will become an important resource for the high energy astrophysics community.

A new way of searching for transients: the ADWO method and its results

NASA Astrophysics Data System (ADS)

Bagoly, Z.; Szecsi, D.; Ripa, J.; Racz, I. I.; Csabai, I.; Dobos, L.; Horvath, I.; Balazs, L. G.; Toth, L. V.

2017-12-01

With the detection of gravitational wave emissions from from merging compact objects, it is now more important than ever to effectively mine the data-set of gamma-satellites for non-triggered, short-duration transients. Hence we developed a new method called the Automatized Detector Weight Optimization (ADWO), applicable for space-borne detectors such as Fermi's GBM and RHESSI's Ge detectors. Provided that the trigger time of an astrophysical event is well known (as in the case of a gravitational wave detection) but the detector response matrix is uncertain, ADWO combines the data of all detectors and energy channels to provide the best signal-to-noise ratio. We used ADWO to successfully identify any potential electromagnetic counterpart of gravitational wave events, as well as to detect previously un-triggered short-duration GRBs in the data-sets.

Automated detection of optical counterparts to GRBs with RAPTOR

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

Wozniak, P. R.; Vestrand, W. T.; Evans, S.

2006-05-19

The RAPTOR system (RAPid Telescopes for Optical Response) is an array of several distributed robotic telescopes that automatically respond to GCN localization alerts. Raptor-S is a 0.4-m telescope with 24 arc min. field of view employing a 1k x 1k Marconi CCD detector, and has already detected prompt optical emission from several GRBs within the first minute of the explosion. We present a real-time data analysis and alert system for automated identification of optical transients in Raptor-S GRB response data down to the sensitivity limit of {approx} 19 mag. Our custom data processing pipeline is designed to minimize the timemore » required to reliably identify transients and extract actionable information. The system utilizes a networked PostgreSQL database server for catalog access and distributes email alerts with successful detections.« less

Putative β4-adrenoceptors in rat ventricle mediate increases in contractile force and cell Ca2+: comparison with atrial receptors and relationship to (−)-[3H]-CGP 12177 binding

PubMed Central

Sarsero, Doreen; Molenaar, Peter; Kaumann, Alberto J; Freestone, Nicholas S

1999-01-01

We identified putative β4-adrenoceptors by radioligand binding, measured increases in ventricular contractile force by (−)-CGP 12177 and (±)-cyanopindolol and demonstrated increased Ca2+ transients by (−)-CGP 12177 in rat cardiomyocytes.(−)-[3H]-CGP 12177 labelled 13–22 fmol mg−1 protein ventricular β1, β2-adrenoceptors (pKD ∼9.0) and 50–90 fmol mg−1 protein putative β4-adrenoceptors (pKD ∼7.3). The affinity values (pKi) for (β1,β2-) and putative β4-adrenoceptors, estimated from binding inhibition, were (−)-propranolol 8.4, 5.7; (−)-bupranolol 9.7, 5.8; (±)-cyanopindolol 10.0,7.4.In left ventricular papillary muscle, in the presence of 30 μM 3-isobutyl-1-methylxanthine, (−)-CGP 12177 and (±)-cyanopindolol caused positive inotropic effects, (pEC50, (−)-CGP 12177, 7.6; (±)-cyanopindolol, 7.0) which were antagonized by (−)-bupranolol (pKB 6.7–7.0) and (−)-CGP 20712A (pKB 6.3–6.6). The cardiostimulant effects of (−)-CGP 12177 in papillary muscle, left and right atrium were antagonized by (±)-cyanopindolol (pKP 7.0–7.4).(−)-CGP 12177 (1 μM) in the presence of 200 nM (−)-propranolol increased Ca2+ transient amplitude by 56% in atrial myocytes, but only caused a marginal increase in ventricular myocytes. In the presence of 1 μM 3-isobutyl-1-methylxanthine and 200 nM (−)-propranolol, 1 μM (−)-CGP 12177 caused a 73% increase in Ca2+ transient amplitude in ventricular myocytes. (−)-CGP 12177 elicited arrhythmic transients in some atrial and ventricular myocytes.Probably by preventing cyclic AMP hydrolysis, 3-isobutyl-1-methylxanthine facilitates the inotropic function of ventricular putative β4-adrenoceptors, suggesting coupling to Gs protein-adenylyl cyclase. The receptor-mediated increases in contractile force are related to increases of Ca2+ in atrial and ventricular myocytes. The agreement of binding affinities of agonists with cardiostimulant potencies is consistent with mediation through putative β4-adrenoceptors labelled with (−)-[3H]-CGP 12177. PMID:10602323

Automatic detection and recognition of traffic signs in stereo images based on features and probabilistic neural networks

NASA Astrophysics Data System (ADS)

Sheng, Yehua; Zhang, Ka; Ye, Chun; Liang, Cheng; Li, Jian

2008-04-01

Considering the problem of automatic traffic sign detection and recognition in stereo images captured under motion conditions, a new algorithm for traffic sign detection and recognition based on features and probabilistic neural networks (PNN) is proposed in this paper. Firstly, global statistical color features of left image are computed based on statistics theory. Then for red, yellow and blue traffic signs, left image is segmented to three binary images by self-adaptive color segmentation method. Secondly, gray-value projection and shape analysis are used to confirm traffic sign regions in left image. Then stereo image matching is used to locate the homonymy traffic signs in right image. Thirdly, self-adaptive image segmentation is used to extract binary inner core shapes of detected traffic signs. One-dimensional feature vectors of inner core shapes are computed by central projection transformation. Fourthly, these vectors are input to the trained probabilistic neural networks for traffic sign recognition. Lastly, recognition results in left image are compared with recognition results in right image. If results in stereo images are identical, these results are confirmed as final recognition results. The new algorithm is applied to 220 real images of natural scenes taken by the vehicle-borne mobile photogrammetry system in Nanjing at different time. Experimental results show a detection and recognition rate of over 92%. So the algorithm is not only simple, but also reliable and high-speed on real traffic sign detection and recognition. Furthermore, it can obtain geometrical information of traffic signs at the same time of recognizing their types.

Transient hypothyroidism in the newborn: to treat or not to treat

PubMed Central

Kanike, Neelakanta; Davis, Ajuah

2017-01-01

Transient congenital hypothyroidism (CH) refers to a temporary deficiency of thyroid hormone identified after birth, with low thyroxine (T4) and elevated thyrotropin (TSH), which later recovers to improved thyroxine production, typically in first few months of infancy. Approximately 17% to 40% of children diagnosed with CH by newborn screening (NBS) programs were later determined to have transient hypothyroidism. Causes of transient CH are prematurity, iodine deficiency, maternal thyrotropin receptor blocking antibodies, maternal intake of anti-thyroid drugs, maternal or neonatal iodine exposure, loss of function mutations and hepatic hemangiomas. The classic clinical symptoms and signs of CH are usually absent immediately after birth in vast majority of infants due to temporary protection from maternal thyroxine. NBS has been largely successful in preventing intellectual disability by early detection of CH by performing thyroid function tests in infants with abnormal screening results. In this review we present the evidence for decision making regarding treatment vs. withholding treatment in infants with transient CH and present a rational approach to identifying transient CH based on American Academy of Pediatrics (AAP) recommendation. PMID:29184815

Photometric Characteristics of Sprites and Elves Derived from JEM-GLIMS Nadir Observations (Invited)

NASA Astrophysics Data System (ADS)

Sato, M.; Takahashi, Y.; Adachi, T.; Kobayashi, N.; Mihara, M.; Ushio, T.; Morimoto, T.; Suzuki, M.; Yamazaki, A.; Inan, U.; Linscott, I.

2013-12-01

The main goal of the JEM-GLIMS mission is to identify the horizontal structures of Transient Luminous Events (TLEs) and spatiotemporal relationship between TLEs and their parent lightning discharges based on the nadir observations from the International Space Station (ISS). For this purpose JEM-GLIMS equips two sets of optical instruments (LSI: CMOS camera, and PH: spectrophotometers) and two sets of radio wave receivers (VLFR: VLF receiver, and VITF: VHF interferometer). As all these instruments are installed at the bottom plane of the bus module facing to the Earth, JEM-GLIMS can carry out the nadir observations continuously. JEM-GLIMS was launched by HTV3 and was successfully installed at the exposed facility of the Japanese Experiment Module (JEM) on August 9, 2012. After the initial checkout operations, JEM-GLIMS finally started continuous observations on November 20, 2012. In the period from November 20, 2012 to June 30, 2013, totally 1597 transient optical events related to lightning flashes and/or TLE emissions were detected by the optical instruments. In 578 of these events, both LSI and PH detected clear transient optical signals well above the noise level. In order to derive sprite events from the detected transient optical events, we analyzed PH light-curve data first and estimated the peak irradiance related to the transient optical flashes. Then, we compared these intensities with the atmospheric transmittance. Finally, LSI image data are examined to clarify the morphological properties of the optical emission. We analyzed a transient optical event detected at 00:56:29.198 UT on December 15, 2012. The peak intensities of PH channels are estimated to be 1.4E-2 W/m2 (150-280 nm), 2.3E-4 W/m2 (316 nm), 5.9E-4 W/m2 (337 nm), 4.0E-4 W/m2 (392 nm), 4.2E-4 W/m2 (762 nm), and 6.3E-2 W/m2 (600-900 nm), respectively. It is found that all these intensities are significantly stronger than the lightning emission affected by the atmospheric transmittance. This fact implies that the light sources exist not only in the troposphere but also in the mesosphere. At the image data obtained by the narrow-band filter camera (LSI-2), a pancake structure with bright spots was confirmed. Thus, we attributed the pancake structure and bright spots to a sprite halo and sprite streamers, respectively. We further analyzed a transient optical event obtained at 01:41:00.466 UT on March 30, 2013. In this event very strong pulse signals are detected only by PH1 (150-280 nm) and PH4 (600-900 nm). Since the field-of-view (FOV) of PH4 is 86.8 deg., which is larger than that of other PH channels (FOV=42.7 deg.), a lightning discharge seems to be occurred within PH4 FOV but without FOV of the other PH channels. Nevertheless, the existence of the strong FUV emission detected by PH1 means the occurrence of elves. At the presentation, we will show the results derived from LSI and PH data analysis and will discuss the photometric characteristics more in detail.

Intraprocedural left ventricular free wall rupture diagnosed by left ventriculogram in a patient with infero-posterior myocardial infarction and severe aortic stenosis.

PubMed

Konishi, Takao; Funayama, Naohiro; Yamamoto, Tadashi; Nishihara, Hiroshi; Hotta, Daisuke; Kikuchi, Kenjiro; Yokoyama, Hideo; Ohori, Katsumi

2016-06-06

Left ventricular wall rupture remains a major lethal complication of acute myocardial infarction and hypertension is a well-known predisposing factor of cardiac rupture after myocardial infarction. An 87-year-old man was admitted to our hospital, diagnosed as acute myocardial infarction (AMI). The echocardiogram showed 0.67-cm(2) aortic valve, consistent with severe aortic stenosis (AS). A coronary angiography showed a chronic occlusion of the proximal left circumflex artery and a 99 % stenosis and thrombus in the mid right coronary artery. During percutaneous angioplasty of the latter, transient hypotension and bradycardia developed at the time of balloon inflation, and low doses of noradrenaline and etilefrine were intravenously administered as needed. The patient suddenly lost consciousness and developed electro-mechanical dissociation. Cardio-pulmonary resuscitation followed by insertion of an intra-aortic balloon pump (IABP) and percutaneous cardiopulmonary support were initiated. The echocardiogram revealed moderate pericardial effusion, though the site of free wall rupture was not distinctly visible. A left ventriculogram clearly showed an infero-posterior apical wall rupture. Surgical treatment was withheld because of the interim development of brain death. In this patient, who presented with severe AS, the administration of catecholamine to stabilize the blood pressure probably increased the intraventricular pressures considerably despite apparently normal measurements of the central aortic pressure. IABP, temporary pacemaker, or both are recommended instead of intravenous catecholamines for patients with AMI complicated with significant AS to stabilize hemodynamic function during angioplasty.

Cardiogenic shock caused by a left midventricular obstruction during refeeding in a patient with anorexia nervosa.

PubMed

Sakamoto, Yoko; Kioka, Hidetaka; Hashimoto, Ryota; Takeda, Saori; Momose, Kota; Ohtani, Tomohito; Yamaguchi, Osamu; Wasa, Masafumi; Nakatani, Satoshi; Sakata, Yasushi

2017-03-01

Refeeding syndrome occurs when reinstating nutrition to severely malnourished patients. It can sometimes be fatal, particularly as a result of cardiac involvement such as congestive heart failure and arrhythmias. The aim of this study was to report a case of cardiogenic shock that occurred during refeeding in a patient with anorexia nervosa (AN). The cardiogenic shock was due to a previously unrecognized mechanism, namely a transient left midventricular obstruction that completely disappeared after treatment. A 46-y-old woman with AN who had followed a carbohydrate- and a fat-deficient diet for >10 y was hospitalized for dyspnea on exertion. She had severely impaired cardiac systolic function on admission and was considered high risk for refeeding syndrome. During a stepwise increase of calories, she showed no electrolyte or mineral abnormalities characteristic of refeeding syndrome. After intravenous administration of a fat emulsion, the patient suffered from cardiogenic shock due to an unexpected mechanism, namely a left midventricular obstruction caused by cardiac hypercontraction, a thickened left ventricular wall, and intravascular volume depletion. With cessation of the fat emulsion and initiation of volume repletion she recovered from shock immediately and her echocardiogram returned to normal by discharge. This case illustrated a novel cause of cardiogenic shock during refeeding and the need for caution during the intravenous administration of a fat emulsion in patients with initial left ventricular systolic dysfunction. Copyright © 2016 Elsevier Inc. All rights reserved.

Reshaping the brain after stroke: The effect of prismatic adaptation in patients with right brain damage.

PubMed

Crottaz-Herbette, Sonia; Fornari, Eleonora; Notter, Michael P; Bindschaedler, Claire; Manzoni, Laura; Clarke, Stephanie

2017-09-01

Prismatic adaptation has been repeatedly reported to alleviate neglect symptoms; in normal subjects, it was shown to enhance the representation of the left visual space within the left inferior parietal cortex. Our study aimed to determine in humans whether similar compensatory mechanisms underlie the beneficial effect of prismatic adaptation in neglect. Fifteen patients with right hemispheric lesions and 11 age-matched controls underwent a prismatic adaptation session which was preceded and followed by fMRI using a visual detection task. In patients, the prismatic adaptation session improved the accuracy of target detection in the left and central space and enhanced the representation of this visual space within the left hemisphere in parts of the temporal convexity, inferior parietal lobule and prefrontal cortex. Across patients, the increase in neuronal activation within the temporal regions correlated with performance improvements in this visual space. In control subjects, prismatic adaptation enhanced the representation of the left visual space within the left inferior parietal lobule and decreased it within the left temporal cortex. Thus, a brief exposure to prismatic adaptation enhances, both in patients and in control subjects, the competence of the left hemisphere for the left space, but the regions extended beyond the inferior parietal lobule to the temporal convexity in patients. These results suggest that the left hemisphere provides compensatory mechanisms in neglect by assuming the representation of the whole space within the ventral attentional system. The rapidity of the change suggests that the underlying mechanism relies on uncovering pre-existing synaptic connections. Copyright © 2017 Elsevier Ltd. All rights reserved.

21 CFR 870.1220 - Electrode recording catheter or electrode recording probe.

Code of Federal Regulations, 2010 CFR

2010-04-01

... electrocardiogram, or to detect cardiac output or left-to-right heart shunts. The device may be unipolar or... a special indicator for cardiac output or left-to-right heart shunt determinations. (b...

21 CFR 870.1220 - Electrode recording catheter or electrode recording probe.

Code of Federal Regulations, 2011 CFR

2011-04-01

... electrocardiogram, or to detect cardiac output or left-to-right heart shunts. The device may be unipolar or... a special indicator for cardiac output or left-to-right heart shunt determinations. (b...

21 CFR 870.1220 - Electrode recording catheter or electrode recording probe.

Code of Federal Regulations, 2012 CFR

2012-04-01

... electrocardiogram, or to detect cardiac output or left-to-right heart shunts. The device may be unipolar or... a special indicator for cardiac output or left-to-right heart shunt determinations. (b...

21 CFR 870.1220 - Electrode recording catheter or electrode recording probe.

Code of Federal Regulations, 2013 CFR

2013-04-01

... electrocardiogram, or to detect cardiac output or left-to-right heart shunts. The device may be unipolar or... a special indicator for cardiac output or left-to-right heart shunt determinations. (b...

21 CFR 870.1220 - Electrode recording catheter or electrode recording probe.

Code of Federal Regulations, 2014 CFR

2014-04-01

... electrocardiogram, or to detect cardiac output or left-to-right heart shunts. The device may be unipolar or... a special indicator for cardiac output or left-to-right heart shunt determinations. (b...

Detectability of compact binary merger macronovae

NASA Astrophysics Data System (ADS)

Rosswog, S.; Feindt, U.; Korobkin, O.; Wu, M.-R.; Sollerman, J.; Goobar, A.; Martinez-Pinedo, G.

2017-05-01

We study the optical and near-infrared luminosities and detectability of radioactively powered electromagnetic transients (‘macronovae’) occuring in the aftermath of binary neutron star and neutron star black hole mergers. We explore the transients that result from the dynamic ejecta and those from different types of wind outflows. Based on full nuclear network simulations we calculate the resulting light curves in different wavelength bands. We scrutinize the robustness of the results by comparing (a) two different nuclear reaction networks and (b) two macronova models. We explore in particular how sensitive the results are to the production of α-decaying trans-lead nuclei. We compare two frequently used mass models: the finite-range Droplet model (FRDM) and the nuclear mass model of Duflo and Zuker (DZ31). We find that the abundance of α-decaying trans-lead nuclei has a significant impact on the observability of the resulting macronovae. For example, the DZ31 model yields considerably larger abundances resulting in larger heating rates and thermalization efficiencies and therefore predicts substantially brighter macronova transients. We find that the dynamic ejecta from NSNS models can reach peak K-band magnitudes in excess of  -15 while those from NSBH cases can reach beyond  -16. Similar values can be reached by some of our wind models. Several of our models (both wind and dynamic ejecta) yield properties that are similar to the transient that was observed in the aftermath of the short GRB 130603B. We further explore the expected macronova detection frequencies for current and future instruments such as VISTA, ZTF and LSST.

The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera

NASA Astrophysics Data System (ADS)

Soares-Santos, M.; Holz, D. E.; Annis, J.; Chornock, R.; Herner, K.; Berger, E.; Brout, D.; Chen, H.-Y.; Kessler, R.; Sako, M.; Allam, S.; Tucker, D. L.; Butler, R. E.; Palmese, A.; Doctor, Z.; Diehl, H. T.; Frieman, J.; Yanny, B.; Lin, H.; Scolnic, D.; Cowperthwaite, P.; Neilsen, E.; Marriner, J.; Kuropatkin, N.; Hartley, W. G.; Paz-Chinchón, F.; Alexander, K. D.; Balbinot, E.; Blanchard, P.; Brown, D. A.; Carlin, J. L.; Conselice, C.; Cook, E. R.; Drlica-Wagner, A.; Drout, M. R.; Durret, F.; Eftekhari, T.; Farr, B.; Finley, D. A.; Foley, R. J.; Fong, W.; Fryer, C. L.; García-Bellido, J.; Gill, M. S. S.; Gruendl, R. A.; Hanna, C.; Kasen, D.; Li, T. S.; Lopes, P. A. A.; Lourenço, A. C. C.; Margutti, R.; Marshall, J. L.; Matheson, T.; Medina, G. E.; Metzger, B. D.; Muñoz, R. R.; Muir, J.; Nicholl, M.; Quataert, E.; Rest, A.; Sauseda, M.; Schlegel, D. J.; Secco, L. F.; Sobreira, F.; Stebbins, A.; Villar, V. A.; Vivas, K.; Walker, A. R.; Wester, W.; Williams, P. K. G.; Zenteno, A.; Zhang, Y.; Abbott, T. M. C.; Abdalla, F. B.; Banerji, M.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; Desai, S.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruen, D.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Jeltema, T.; Johnson, M. W. G.; Johnson, M. D.; Kent, S.; Krause, E.; Kron, R.; Kuehn, K.; Kuhlmann, S.; Lahav, O.; Lima, M.; Maia, M. A. G.; March, M.; McMahon, R. G.; Menanteau, F.; Miquel, R.; Mohr, J. J.; Nichol, R. C.; Nord, B.; Ogando, R. L. C.; Petravick, D.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Thomas, R. C.; Troxel, M. A.; Vikram, V.; Wechsler, R. H.; Weller, J.; Dark Energy Survey; Dark Energy Camera GW-EM Collaboration

2017-10-01

We present the Dark Energy Camera (DECam) discovery of the optical counterpart of the first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon as the localization region became accessible from Chile. We imaged 70 deg2 in the I and z bands, covering 93% of the initial integrated localization probability, to a depth necessary to identify likely optical counterparts (e.g., a kilonova). At 11.4 hr post-merger we detected a bright optical transient located 10\\buildrel{\\prime\\prime}\\over{.} 6 from the nucleus of NGC 4993 at redshift z = 0.0098, consistent (for {H}0=70 km s-1 Mpc-1) with the distance of 40 ± 8 Mpc reported by the LIGO Scientific Collaboration and the Virgo Collaboration (LVC). At detection the transient had magnitudes of I=17.3 and z=17.4, and thus an absolute magnitude of {M}I=-15.7, in the luminosity range expected for a kilonova. We identified 1500 potential transient candidates. Applying simple selection criteria aimed at rejecting background events such as supernovae, we find the transient associated with NGC 4993 as the only remaining plausible counterpart, and reject chance coincidence at the 99.5% confidence level. We therefore conclude that the optical counterpart we have identified near NGC 4993 is associated with GW170817. This discovery ushers in the era of multi-messenger astronomy with gravitational waves and demonstrates the power of DECam to identify the optical counterparts of gravitational-wave sources.

On the Interpretation of the Fermi-GBM Transient Observed in Coincidence with LIGO Gravitational-wave Event GW150914

NASA Astrophysics Data System (ADS)

Connaughton, V.; Burns, E.; Goldstein, A.; Blackburn, L.; Briggs, M. S.; Christensen, N.; Hui, C. M.; Kocevski, D.; Littenberg, T.; McEnery, J. E.; Racusin, J.; Shawhan, P.; Veitch, J.; Wilson-Hodge, C. A.; Bhat, P. N.; Bissaldi, E.; Cleveland, W.; Giles, M. M.; Gibby, M. H.; von Kienlin, A.; Kippen, R. M.; McBreen, S.; Meegan, C. A.; Paciesas, W. S.; Preece, R. D.; Roberts, O. J.; Stanbro, M.; Veres, P.

2018-01-01

The weak transient detected by the Fermi Gamma-ray Burst Monitor (GBM) 0.4 s after GW150914 has generated much speculation regarding its possible association with the black hole binary merger. Investigation of the GBM data by Connaughton et al. revealed a source location consistent with GW150914 and a spectrum consistent with a weak, short gamma-ray burst. Greiner et al. present an alternative technique for fitting background-limited data in the low-count regime, and call into question the spectral analysis and the significance of the detection of GW150914-GBM presented in Connaughton et al. The spectral analysis of Connaughton et al. is not subject to the limitations of the low-count regime noted by Greiner et al. We find Greiner et al. used an inconsistent source position and did not follow the steps taken in Connaughton et al. to mitigate the statistical shortcomings of their software when analyzing this weak event. We use the approach of Greiner et al. to verify that our original spectral analysis is not biased. The detection significance of GW150914-GBM is established empirically, with a false-alarm rate (FAR) of ∼ {10}-4 Hz. A post-trials false-alarm probability (FAP) of 2.2× {10}-3 (2.9σ ) of this transient being associated with GW150914 is based on the proximity in time to the gravitational-wave event of a transient with that FAR. The FAR and the FAP are unaffected by the spectral analysis that is the focus of Greiner et al.

Simulating intrafraction prostate motion with a random walk model.

PubMed

Pommer, Tobias; Oh, Jung Hun; Munck Af Rosenschöld, Per; Deasy, Joseph O

2017-01-01

Prostate motion during radiation therapy (ie, intrafraction motion) can cause unwanted loss of radiation dose to the prostate and increased dose to the surrounding organs at risk. A compact but general statistical description of this motion could be useful for simulation of radiation therapy delivery or margin calculations. We investigated whether prostate motion could be modeled with a random walk model. Prostate motion recorded during 548 radiation therapy fractions in 17 patients was analyzed and used for input in a random walk prostate motion model. The recorded motion was categorized on the basis of whether any transient excursions (ie, rapid prostate motion in the anterior and superior direction followed by a return) occurred in the trace and transient motion. This was separately modeled as a large step in the anterior/superior direction followed by a returning large step. Random walk simulations were conducted with and without added artificial transient motion using either motion data from all observed traces or only traces without transient excursions as model input, respectively. A general estimate of motion was derived with reasonable agreement between simulated and observed traces, especially during the first 5 minutes of the excursion-free simulations. Simulated and observed diffusion coefficients agreed within 0.03, 0.2 and 0.3 mm 2 /min in the left/right, superior/inferior, and anterior/posterior directions, respectively. A rapid increase in variance at the start of observed traces was difficult to reproduce and seemed to represent the patient's need to adjust before treatment. This could be estimated somewhat using artificial transient motion. Random walk modeling is feasible and recreated the characteristics of the observed prostate motion. Introducing artificial transient motion did not improve the overall agreement, although the first 30 seconds of the traces were better reproduced. The model provides a simple estimate of prostate motion during delivery of radiation therapy.

Usefulness of free-breathing readout-segmented echo-planar imaging (RESOLVE) for detection of malignant liver tumors: comparison with single-shot echo-planar imaging (SS-EPI).

PubMed

Tokoro, Hirokazu; Fujinaga, Yasunari; Ohya, Ayumi; Ueda, Kazuhiko; Shiobara, Aya; Kitou, Yoshihiro; Ueda, Hitoshi; Kadoya, Masumi

2014-10-01

We aimed to clarify the usefulness of free-breathing readout-segmented echo-planar imaging (RESOLVE), which is multi-shot echo-planar imaging based on a 2D-navigator-based reacquisition technique, for detecting malignant liver tumor. In 77 patients with malignant liver tumors, free-breathing RESOLVE and respiratory-triggered single-shot echo-planar imaging (SS-EPI) at 3-T MR unit were performed. We set a scan time up to approximately 5 min (300s) before examination, measured actual scan time and assessed (1) susceptibility and (2) motion artifacts in the right and left liver lobes (3, no artifact; 1, marked), and (3) detectability of malignant liver tumors (3, good; 1, poor) using a 3-point scale. The median actual scan time of RESOLVE/SS-EPI was 365/423s. The median scores of each factor in RESOLVE/SS-EPI were as following in this order: (1) 3/2 (right lobe); 3/3 (left lobe), (2) 2/3 (right lobe); 1/2 (left lobe), and (3) 3/3, respectively. Significant differences were noted between RESOLVE and SS-EPI in all evaluated factors (P<0.05) except for susceptibility of left lobe and detectability of the lesions. Despite the effect of motion artifacts, RESOLVE provides a comparable detectability of the lesion and the advantage of reducing scanning time compared with SS-EPI. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Auditory Conflict Resolution Correlates with Medial–Lateral Frontal Theta/Alpha Phase Synchrony

PubMed Central

Huang, Samantha; Rossi, Stephanie; Hämäläinen, Matti; Ahveninen, Jyrki

2014-01-01

When multiple persons speak simultaneously, it may be difficult for the listener to direct attention to correct sound objects among conflicting ones. This could occur, for example, in an emergency situation in which one hears conflicting instructions and the loudest, instead of the wisest, voice prevails. Here, we used cortically-constrained oscillatory MEG/EEG estimates to examine how different brain regions, including caudal anterior cingulate (cACC) and dorsolateral prefrontal cortices (DLPFC), work together to resolve these kinds of auditory conflicts. During an auditory flanker interference task, subjects were presented with sound patterns consisting of three different voices, from three different directions (45° left, straight ahead, 45° right), sounding out either the letters “A” or “O”. They were asked to discriminate which sound was presented centrally and ignore the flanking distracters that were phonetically either congruent (50%) or incongruent (50%) with the target. Our cortical MEG/EEG oscillatory estimates demonstrated a direct relationship between performance and brain activity, showing that efficient conflict resolution, as measured with reduced conflict-induced RT lags, is predicted by theta/alpha phase coupling between cACC and right lateral frontal cortex regions intersecting the right frontal eye fields (FEF) and DLPFC, as well as by increased pre-stimulus gamma (60–110 Hz) power in the left inferior fontal cortex. Notably, cACC connectivity patterns that correlated with behavioral conflict-resolution measures were found during both the pre-stimulus and the pre-response periods. Our data provide evidence that, instead of being only transiently activated upon conflict detection, cACC is involved in sustained engagement of attentional resources required for effective sound object selection performance. PMID:25343503

Auditory conflict resolution correlates with medial-lateral frontal theta/alpha phase synchrony.

PubMed

Huang, Samantha; Rossi, Stephanie; Hämäläinen, Matti; Ahveninen, Jyrki

2014-01-01

When multiple persons speak simultaneously, it may be difficult for the listener to direct attention to correct sound objects among conflicting ones. This could occur, for example, in an emergency situation in which one hears conflicting instructions and the loudest, instead of the wisest, voice prevails. Here, we used cortically-constrained oscillatory MEG/EEG estimates to examine how different brain regions, including caudal anterior cingulate (cACC) and dorsolateral prefrontal cortices (DLPFC), work together to resolve these kinds of auditory conflicts. During an auditory flanker interference task, subjects were presented with sound patterns consisting of three different voices, from three different directions (45° left, straight ahead, 45° right), sounding out either the letters "A" or "O". They were asked to discriminate which sound was presented centrally and ignore the flanking distracters that were phonetically either congruent (50%) or incongruent (50%) with the target. Our cortical MEG/EEG oscillatory estimates demonstrated a direct relationship between performance and brain activity, showing that efficient conflict resolution, as measured with reduced conflict-induced RT lags, is predicted by theta/alpha phase coupling between cACC and right lateral frontal cortex regions intersecting the right frontal eye fields (FEF) and DLPFC, as well as by increased pre-stimulus gamma (60-110 Hz) power in the left inferior fontal cortex. Notably, cACC connectivity patterns that correlated with behavioral conflict-resolution measures were found during both the pre-stimulus and the pre-response periods. Our data provide evidence that, instead of being only transiently activated upon conflict detection, cACC is involved in sustained engagement of attentional resources required for effective sound object selection performance.

Periprocedural intracardiac echocardiography for left atrial appendage closure: a dual-center experience.

PubMed

Berti, Sergio; Paradossi, Umberto; Meucci, Francesco; Trianni, Giuseppe; Tzikas, Apostolos; Rezzaghi, Marco; Stolkova, Miroslava; Palmieri, Cataldo; Mori, Fabio; Santoro, Gennaro

2014-09-01

This dual-center study sought to demonstrate the utility and safety of intracardiac echocardiography (ICE) in providing adequate imaging guidance as an alternative to transesophageal echocardiography (TEE) during Amplatzer Cardiac Plug device implantation. Over 90% of intracardiac thrombi in atrial fibrillation originate from the left atrial appendage (LAA). Patients with contraindications to anticoagulation are potential candidates for LAA percutaneous occlusion. TEE is typically used to guide implantation. ICE-guided percutaneous LAA closure was performed in 121 patients to evaluate the following tasks typically achieved by TEE: assessment of the LAA dimension for device sizing; guidance of transseptal puncture; verification of the delivery sheath position; confirmation of location and stability of the device before and after release and continuous monitoring to detect procedural complications. In 51 consecutive patients, we compared the measurements obtained by ICE and fluoroscopy to choose the size of the device. The device was successfully implanted in 117 patients, yielding a technical success rate of 96.7%. Procedural success was achieved in 113 cases (93.4%). Four major adverse events (3 cardiac tamponades and 1 in-hospital transient ischemic attack) occurred. There was significant correlation in the measurements for device sizing assessed by angiography and ICE (r = 0.94, p < 0.0001). ICE imaging was able to perform the tasks typically provided by TEE during implantation of the Amplatzer Cardiac Plug device for LAA occlusion. Therefore, we provide evidence that the use of ICE offered accurate measurements of LAA dimension in order to select the correct device sizes. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

[Functional mapping using subdural electrodes combined with monitoring during awake craniotomy enabled preservation of function and extensive resection of a glioma adjacent to the parietal lobe language sites: a case report].

PubMed

Takebayashi, Kento; Saito, Taiichi; Nitta, Masayuki; Tamura, Manabu; Maruyama, Takashi; Muragaki, Yoshihiro; Okada, Yoshikazu

2015-01-01

Surgical resection of gliomas located in the dominant parietal lobe is difficult because this lesion is surrounded by multiple functional areas. Although functional mapping during awake craniotomy is very useful for resection of gliomas adjacent to eloquent areas, the limited time available makes it difficult to sufficiently evaluate multiple functions, such as language, calculative ability, distinction of right and left sides, and finger recognition. Here, we report a case of anaplastic oligodendroglioma, which was successfully treated with a combination of functional mapping using subdural electrodes and monitoring under awake craniotomy for glioma. A 32-year-old man presented with generalized seizure. Magnetic resonance imaging revealed a non-enhanced tumor in the left angular and supramarginal gyri. In addition, the tumor showed high accumulation on 11C-methionine positron emission tomography(PET)(tumor/normal brain tissue ratio=3.20). Preparatory mapping using subdural electrodes showed absence of brain function on the tumor lesion. Surgical removal was performed using cortical mapping during awake craniotomy with an updated navigation system using intraoperative magnetic resonance imaging(MRI). The tumor was resected until aphasia was detected by functional monitoring, and the extent of tumor resection was 93%. The patient showed transient transcortical aphasia and Gerstmann's syndrome after surgery but eventually recovered. The pathological diagnosis was anaplastic oligodendroglioma, and the patient was administered chemo-radiotherapy. The patient has been progression free for more than 2 years. The combination of subdural electrode mapping and monitoring during awake craniotomy is useful in order to achieve preservation of function and extensive resection for gliomas in the dominant parietal lobe.

Active Coupled Oscillators in the Inner Ear

NASA Astrophysics Data System (ADS)

Strimbu, Clark Elliott

Auditory and vestibular systems are endowed with an active process that enables them to detect signals as small as a few Angstroms; they also exhibit frequency selectivity; show strong nonlinearities; and can exhibit as spontaneous activity. Much of this active process comes from the sensory hair cells at the periphery of the auditory and vestibular systems. Each hair cell is capped by an eponymous hair bundle, a specialized structure that transduces mechanical forces into electrical signals. Experiments on mechanically decoupled cells from the frog sacculus have shown that individual hair bundles behave in an active manner analogous to an intact organ suggesting a common cellular basis for the active processes seen in many species. In particular, mechanically decoupled hair bundles show rapid active movements in response to transient stimuli and exhibit spontaneous oscillations. However, a single mechanosensitive hair cell is unable to match the performance of an entire organ. In vivo, hair bundles are often coupled to overlying membranes, gelatinous extracellular matrices. We used an in vitro preparation of the frog sacculus in which the otolithic membrane has been left intact. Under natural coupling conditions, there is a strong degree of correlation across the saccular epithelium, suggesting that the collective response of many cells contributes to the extreme sensitivity of this organ. When the membrane is left intact, the hair bundles do not oscillate spontaneously, showing that the natural coupling and loading tunes them into a quiescent regime. However, when stimulated by a pulse, the bundles show a rapid biphasic response that is abolished when the transduction channels are blocked. The active forces generated by the bundles are sufficient to move the overlying membrane.

ATCA radio detection of the new X-ray transient MAXI J1813-095 as a candidate radio-quiet black hole X-ray binary

NASA Astrophysics Data System (ADS)

Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Tetarenko, A. J.; JACPOT XRB Collaboration

2018-02-01

We observed the new X-ray transient MAXI J1813-095 (ATels #11323, #11326, #11332) with the Australia Telescope Compact Array (ATCA) between 2018-02-22 20:52 UT and 2018-02-23 02:59 UT. Our observations were taken simultaneously at 5.5 and 9 GHz, with a bandwidth of 2 GHz at each frequency.

Search for Hard X-Ray Emission from the Soft X-Ray Transient Aquila X-1

NASA Astrophysics Data System (ADS)

Harmon, B. A.; Zhang, S. N.; Paciesas, W. S.; Tavani, M.; Kaaret, P.; Ford, E.

1994-12-01

We are investigating the possibility of hard x-ray emission from the recurrent soft x-ray transient and x-ray burst source Aquila X-1 (Aql X-1). Outbursts of this source are relatively frequent with a spacing of ~ 4-10 months (Kitamoto, S. et al. 1993, ApJ, 403, 315). The recent detections of hard tails (\\(>\\)20 keV) in low luminosity x-ray bursters (Barret, D. & Vedrenne, G. 1994, ApJ Supp. S. 92, 505) suggest that neutron star transient systems such as Aql X-1 can produce hard x-ray emission which is detectable by BATSE. We are correlating reported optical and soft x-ray observations since 1991 of Aql X-1 with BATSE observations in order to search for hard x-ray emission episodes, and to study their temporal and spectral evolution. We will present preliminary results of this search in the 20-1000 keV band using the Earth occultation technique applied to the large area detectors. If this work is successful, we hope to alert the astronomical community for the next Aql X-1 outburst expected in 1995. Simultaneous x-ray/hard x-ray and optical observations of Aql X-1 during outburst would be of great importance for the modeling of soft x-ray transients and related systems.

Magnetic resonance imaging detection of multiple ischemic injury produced in an adult rat model of minor stroke followed by mild transient cerebral ischemia.

PubMed

Tuor, Ursula I; Qiao, Min

2017-04-01

To determine whether cumulative brain damage produced adjacent to a minor stroke that is followed by a mild transient ischemia is detectable with MRI and histology, and whether acute or chronic recovery between insults influences this damage. A minor photothrombotic (PT) stroke was followed acutely (1-2 days) or chronically (7 days) by a mild transient middle cerebral artery occlusion (tMCAO). MRI was performed after each insult, followed by final histology. The initial PT produced small hyperintense T 2 and DW infarct lesions and peri-lesion regions of scattered necrosis and modestly increased T 2 . Following tMCAO, in a slice and a region adjacent to the PT, a region of T 2 augmentation was observed when recovery between insults was acute but not chronic. Within the PT slice, a modest region of exacerbated T 2 change proximate to the PT was also observed in the chronic group. Corresponding histological changes within regions of augmented T 2 included increased vacuolation and cell death. Within regions adjacent to an experimental minor stroke, a recurrence of a mild transient cerebral ischemia augmented T 2 above increases produced by tMCAO alone, reflecting increased damage in this region. Exacerbation appeared broader with acute versus chronic recovery between insults.

[Transient congenital hypothyroidism due to biallelic defects of DUOX2 gene. Two clinical cases].

PubMed

Enacán, Rosa E; Masnata, María E; Belforte, Fiorella; Papendieck, Patricia; Olcese, María C; Siffo, Sofía; Gruñeiro-Papendieck, Laura; Targovnik, Héctor; Rivolta, Carina M; Chiesa, Ana E

2017-06-01

Congenital hypothyroidism affects 1:2000-3000 newborns detected by neonatal screening programs. Dual oxidases, DUOX1 and 2, generate hydrogen peroxide needed for the thyroid hormone synthesis. Hipotiroidismo congénito transitorio por defectos bialélicos del gen DUOX2. Dos casos clínicos Transient congenital hypothyroidism due to biallelic defects of DUOX2 gene. Two clinical cases Mutations in the DUOX2 gene have been described in transient and permanent congenital hypothyroidism. Two brothers with congenital hypothyroidism detected by neonatal screening with eutopic gland and elevated thyroglobulin are described. They were treated with levothyroxine until it could be suspended in both during childhood, assuming the picture as transient. Organification disorder was confirmed. Both patients were compounds heterozygous for a mutation in exon 9 of the paternal allele (c.1057_1058delTT, p.F353PfsX36 or p.F353fsX388) and in exon 11 of the maternal allele (c.1271T > G, p.Y425X) of DUOX2 gene. Our finding confirms that the magnitude of the defect of DUOX2 is not related to the number of inactivated alleles, suggesting compensatory mechanisms in the peroxide supply. Sociedad Argentina de Pediatría.

Swift Follow-Up Observations of Candidate Gravitational-Wave Transient Events

NASA Technical Reports Server (NTRS)

Evans, P. A.; Fridriksson, J. K.; Gehrels, N.; Homan, J.; Osborne, J. P.; Siegel, M.; Beardmore, A.; Handbauer, P.; Gelbord, J.; Kennea, J. A.;

Swift Follow-up Observations of Candidate Gravitational-wave Transient Events

NASA Astrophysics Data System (ADS)

Evans, P. A.; Fridriksson, J. K.; Gehrels, N.; Homan, J.; Osborne, J. P.; Siegel, M.; Beardmore, A.; Handbauer, P.; Gelbord, J.; Kennea, J. A.; Smith, M.; Zhu, Q.; LIGO Scientific Collaboration; Virgo Collaboration; Aasi, J.; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Ajith, P.; Allen, B.; Allocca, A.; Amador Ceron, E.; Amariutei, D.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Ast, S.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P.; Ballardin, G.; Ballmer, S.; Bao, Y.; Barayoga, J. C. B.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Basti, A.; Batch, J.; Bauchrowitz, J.; Bauer, Th. S.; Bebronne, M.; Beck, D.; Behnke, B.; Bejger, M.; Beker, M. G.; Bell, A. S.; Bell, C.; Belopolski, I.; Benacquista, M.; Berliner, J. M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bhadbade, T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biswas, R.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Blom, M.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bond, C.; Bondarescu, R.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, S.; Bosi, L.; Bouhou, B.; Braccini, S.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Breyer, J.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burguet-Castell, J.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Calloni, E.; Camp, J. B.; Campsie, P.; Cannon, K.; Canuel, B.; Cao, J.; Capano, C. D.; Carbognani, F.; Carbone, L.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chalermsongsak, T.; Charlton, P.; Chassande-Mottin, E.; Chen, W.; Chen, X.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Chow, J.; Christensen, N.; Chua, S. S. Y.; Chung, C. T. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J. A.; Clayton, J. H.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colacino, C. N.; Colla, A.; Colombini, M.; Conte, A.; Conte, R.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M.; Coulon, J.-P.; Couvares, P.; Coward, D. M.; Cowart, M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, R. M.; Dahl, K.; Damjanic, M.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dattilo, V.; Daudert, B.; Daveloza, H.; Davier, M.; Daw, E. J.; Day, R.; Dayanga, T.; De Rosa, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; Del Pozzo, W.; Dent, T.; Dergachev, V.; DeRosa, R.; Dhurandhar, S.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Emilio, M. Di Paolo; Di Virgilio, A.; Díaz, M.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorsher, S.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Eikenberry, S.; Endrőczi, G.; Engel, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Farr, B. F.; Favata, M.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Ferrini, F.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Foley, S.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franc, J.; Franco, S.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M. A.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fujimoto, M.-K.; Fulda, P. J.; Fyffe, M.; Gair, J.; Galimberti, M.; Gammaitoni, L.; Garcia, J.; Garufi, F.; Gáspár, M. E.; Gelencser, G.; Gemme, G.; Genin, E.; Gennai, A.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gil-Casanova, S.; Gill, C.; Gleason, J.; Goetz, E.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Griffo, C.; Grote, H.; Grover, K.; Grunewald, S.; Guidi, G. M.; Guido, C.; Gupta, R.; Gustafson, E. K.; Gustafson, R.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Hayau, J.-F.; Heefner, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Herrera, V.; Heurs, M.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Holtrop, M.; Hong, T.; Hooper, S.; Hough, J.; Howell, E. J.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Izumi, K.; Jacobson, M.; James, E.; Jang, Y. J.; Jaranowski, P.; Jesse, E.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Kalmus, P.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kasprzack, M.; Kasturi, R.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kaufman, K.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Keitel, D.; Kelley, D.; Kells, W.; Keppel, D. G.; Keresztes, Z.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, B. K.; Kim, C.; Kim, H.; Kim, K.; Kim, N.; Kim, Y. M.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kline, J.; Kokeyama, K.; Kondrashov, V.; Koranda, S.; Korth, W. Z.; Kowalska, I.; Kozak, D.; Kringel, V.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kurdyumov, R.; Kwee, P.; Lam, P. K.; Landry, M.; Langley, A.; Lantz, B.; Lastzka, N.; Lawrie, C.; Lazzarini, A.; Le Roux, A.; Leaci, P.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Leong, J. R.; Leonor, I.; Leroy, N.; Letendre, N.; Lhuillier, V.; Li, J.; Li, T. G. F.; Lindquist, P. E.; Litvine, V.; Liu, Y.; Liu, Z.; Lockerbie, N. A.; Lodhia, D.; Logue, J.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J.; Lubinski, M.; Lück, H.; Lundgren, A. P.; Macarthur, J.; Macdonald, E.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Mageswaran, M.; Mailand, K.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Marque, J.; Martelli, F.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Masserot, A.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McDaniel, P.; McGuire, S. C.; McIntyre, G.; McIver, J.; Meadors, G. D.; Mehmet, M.; Meier, T.; Melatos, A.; Melissinos, A. C.; Mendell, G.; Menéndez, D. F.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Michel, C.; Milano, L.; Miller, J.; Minenkov, Y.; Mingarelli, C. M. F.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moe, B.; Mohan, M.; Mohapatra, S. R. P.; Moraru, D.; Moreno, G.; Morgado, N.; Morgia, A.; Mori, T.; Morriss, S. R.; Mosca, S.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Müller-Ebhardt, H.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nash, T.; Naticchioni, L.; Necula, V.; Nelson, J.; Neri, I.; Newton, G.; Nguyen, T.; Nishizawa, A.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E.; Nuttall, L.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Oldenberg, R. G.; O'Reilly, B.; O'Shaughnessy, R.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Page, A.; Palladino, L.; Palomba, C.; Pan, Y.; Pankow, C.; Paoletti, F.; Paoletti, R.; Papa, M. A.; Parisi, M.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Pedraza, M.; Penn, S.; Perreca, A.; Persichetti, G.; Phelps, M.; Pichot, M.; Pickenpack, M.; Piergiovanni, F.; Pierro, V.; Pihlaja, M.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Poggiani, R.; Pöld, J.; Postiglione, F.; Poux, C.; Prato, M.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Quetschke, V.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radkins, H.; Raffai, P.; Rakhmanov, M.; Ramet, C.; Rankins, B.; Rapagnani, P.; Raymond, V.; Re, V.; Reed, C. M.; Reed, T.; Regimbau, T.; Reid, S.; Reitze, D. H.; Ricci, F.; Riesen, R.; Riles, K.; Roberts, M.; Robertson, N. A.; Robinet, F.; Robinson, C.; Robinson, E. L.; Rocchi, A.; Roddy, S.; Rodriguez, C.; Rodruck, M.; Rolland, L.; Rollins, J. G.; Romano, J. D.; Romano, R.; Romie, J. H.; Rosińska, D.; Röver, C.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Salemi, F.; Sammut, L.; Sandberg, V.; Sankar, S.; Sannibale, V.; Santamaría, L.; Santiago-Prieto, I.; Santostasi, G.; Saracco, E.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Savage, R. L.; Schilling, R.; Schnabel, R.; Schofield, R. M. S.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Seifert, F.; Sellers, D.; Sentenac, D.; Sergeev, A.; Shaddock, D. A.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sidery, T. L.; Siemens, X.; Sigg, D.; Simakov, D.; Singer, A.; Singer, L.; Sintes, A. M.; Skelton, G. R.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, R. J. E.; Smith-Lefebvre, N. D.; Somiya, K.; Sorazu, B.; Speirits, F. C.; Sperandio, L.; Stefszky, M.; Steinert, E.; Steinlechner, J.; Steinlechner, S.; Steplewski, S.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S. E.; Stroeer, A. S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sung, M.; Susmithan, S.; Sutton, P. J.; Swinkels, B.; Szeifert, G.; Tacca, M.; Taffarello, L.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, R.; ter Braack, A. P. M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Thüring, A.; Titsler, C.; Tokmakov, K. V.; Tomlinson, C.; Toncelli, A.; Tonelli, M.; Torre, O.; Torres, C. V.; Torrie, C. I.; Tournefier, E.; Travasso, F.; Traylor, G.; Tse, M.; Ugolini, D.; Vahlbruch, H.; Vajente, G.; van den Brand, J. F. J.; Van Den Broeck, C.; van der Putten, S.; van Veggel, A. A.; Vass, S.; Vasuth, M.; Vaulin, R.; Vavoulidis, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Villar, A. E.; Vinet, J.-Y.; Vitale, S.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A.; Wade, L.; Wade, M.; Waldman, S. J.; Wallace, L.; Wan, Y.; Wang, M.; Wang, X.; Wanner, A.; Ward, R. L.; Was, M.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D. J.; Whiting, B. F.; Wiesner, K.; Wilkinson, C.; Willems, P. A.; Williams, L.; Williams, R.; Willke, B.; Wimmer, M.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Wittel, H.; Woan, G.; Wooley, R.; Worden, J.; Yablon, J.; Yakushin, I.; Yamamoto, H.; Yamamoto, K.; Yancey, C. C.; Yang, H.; Yeaton-Massey, D.; Yoshida, S.; Yvert, M.; Zadrożny, A.; Zanolin, M.; Zendri, J.-P.; Zhang, F.; Zhang, L.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zweizig, J.

2012-12-01

We present the first multi-wavelength follow-up observations of two candidate gravitational-wave (GW) transient events recorded by LIGO and Virgo in their 2009-2010 science run. The events were selected with low latency by the network of GW detectors (within less than 10 minutes) and their candidate sky locations were observed by the Swift observatory (within 12 hr). Image transient detection was used to analyze the collected electromagnetic data, which were found to be consistent with background. Off-line analysis of the GW data alone has also established that the selected GW events show no evidence of an astrophysical origin; one of them is consistent with background and the other one was a test, part of a "blind injection challenge." With this work we demonstrate the feasibility of rapid follow-ups of GW transients and establish the sensitivity improvement joint electromagnetic and GW observations could bring. This is a first step toward an electromagnetic follow-up program in the regime of routine detections with the advanced GW instruments expected within this decade. In that regime, multi-wavelength observations will play a significant role in completing the astrophysical identification of GW sources. We present the methods and results from this first combined analysis and discuss its implications in terms of sensitivity for the present and future instruments.

MULTIPLE EVANESCENT WHITE DOT SYNDROME WITH SUBRETINAL DEPOSITS.

PubMed

Gal-Or, Orly; Sorenson, John A; Gattoussi, Sarra; Dolz-Marco, Rosa; Freund, K Bailey

2017-06-13

To describe the multimodal imaging findings of transient subretinal deposits occurring in multiple evanescent white dot syndrome (MEWDS). The multimodal imaging characteristics of transient subretinal deposits occurring in MEWDS were investigated with ultra-widefield color and fundus autofluorescence, cross-sectional and en-face optical coherence tomography (OCT), en face OCT-angiography, and quantitative autofluorescence. A 28-year-old woman presented with photopsia and temporal visual field loss in her right eye. Her best-corrected visual acuity was 20/20 in her right eye and 20/25 in her left eye. Funduscopic examination showed characteristic peripapillary hyperautofluorescent white dots of MEWDS corresponding to ellipsoid zone disruption on OCT. These lesions became confluent throughout the posterior fundus over the next 4 weeks. As the patient's symptoms were resolving, a second type of transient hyperautofluorescent lesion was noted which corresponded to hyperreflective subretinal deposits on cross-sectional and en face structural OCT. These subretinal deposits were most evident at 10-week follow-up and had nearly resolved at 14-week follow-up. Quantitative autofluorescence showed that, unlike the acute MEWDS lesions, the hyperautoflurescence of the subretinal deposits persisted after photobleaching. At multiple time points over 14 weeks of follow-up, OCT angiography showed no evidence of retinal or choroidal flow abnormalities. Transient subretinal deposits may develop during MEWDS in areas of previous diffuse outer retinal disruption. As these deposits remain hyperautoflurescent on quantitative autofluorescence after photobleaching, they may represent accumulations of debris originating from damaged photoreceptor outer segments.

Transient prehypertensive treatment in spontaneously hypertensive rats: a comparison of losartan and amlodipine regarding long-term blood pressure, cardiac and renal protection.

PubMed

Peng, Feng; Lin, Jinxiu; Lin, Liming; Tang, Hong

2012-12-01

The aim of this study was to compare the effectiveness of transient prehypertensive treatment with losartan compared with amlodipine in spontaneously hypertensive rats (SHRs) on long-term blood pressure (BP), cardiac and renal protection. SHRs were prehypertensively treated with losartan, amlodipine or saline. Rats were followed up until 46 weeks of age. The left ventricular (LV) geometry and function were assessed by echocardiography. Angiotensin II (Ang II) and aldosterone (Aldo) were measured by radioimmunoassay. Ang II type 1 (AT1R) and type 2 (AT2R) receptor protein expression was determined by western blotting. The systolic blood pressure (SBP) in losartan-treated SHRs (SHR-Los) was persistently reduced until 46 weeks of age, but returned to untreated SHR levels in amlodipine-treated SHRs (SHR-Aml) from 30 weeks onwards. Compared to untreated SHRs, the albuminuria excretion in SHR-Los at week 46 was markedly decreased, the plasma, myocardium and renal tissue Ang II and Aldo levels in SHR-Los at week 46 were markedly decreased; AT1R and TGF-β1 protein expression was downregulated and AT2R protein was upregulated. Compared to untreated SHRs, the left ventricular mass index (LVMI) and collagen volume fraction (CVF) in SHR-Los were markedly decreased until week 46, and the left ventricular ejection fraction (LVEF) and cardiac brain natriuretic peptide mRNA expression were improved, whereas similar LVMI and elevated CVF were observed in SHR-Aml, and the LVEF decreased significantly below that of untreated SHRs at week 46, with cardiac BNP mRNA expression increasing slightly. Prehypertensive treatment with losartan was more effective than amlodipine on delaying long-term BP increase and ameliorating cardiac, renal structure and function, which may be related to the permanent attenuation of the circulating and local renin-angiotensin systems.

Prenatal diagnosis of congenital syphilis presenting with transient pleural effusion in the fetus: a case report and rising incidence of congenital syphilis in South Korea.

PubMed

Park, J Y; Han, G H; Kwon, D Y; Hong, H R; Seol, H J

2015-01-01

Congenital syphilis is preventable and curable if maternal infection is detected early, and pregnant women in Korea are screened routinely for this disease. Nevertheless, the incidence of congenital syphilis is not decreasing. Prenatal diagnosis of congenital syphilis is difficult and treatment is usually based on maternal syphilis serology. Prenatal ultrasonographic examination may sometimes reveal abnormal features suggesting congenital infection. The authors report a case of congenital syphilis that was diagnosed in both fetus and asymptomatic mother following detection on prenatal ultrasonography of transient fetal pleural effusion. The case is noteworthy for its sonographic presentation as fetal pleural effusion rapidly resolved spontaneously.

Raman spectrum of bacteriochlorophyll a in the S1 state

NASA Astrophysics Data System (ADS)

Nishizawa, Ei-ichi; Hashimoto, Hideki; Koyama, Yasushi

1991-07-01

The S 1 Raman spectrum of bacteriochlorophyll a is reported for the first time. A one-color experiment using the 351 nm picosecond pulses (duration 50 ps and repetition 1 kHz) for tetrahydrofuran solution detected a transient species, which showed distinct Raman lines at 1567, 1409 and 1320 cm -1 and weak profiles around 1169, 1092, 1051 and 794 cm -1. The other one-color experiment using the 355 nm nanosecond pulses (duration 12 ns and repetition 10 Hz) detected the T 1 species reported previously showing Raman lines at 1578 and 1330 cm -1. Thus, the newly identified transient species, which was pumped and probed within 50 ps, is assigned to S 1.

Discovery of Possible Nova in M31 : P60-M31-080723

NASA Astrophysics Data System (ADS)

Kasliwal, M. M.; Cenko, S. B.; Rau, A.; Ofek, E. O.; Quimby, R.; Kulkarni, S. R.

2008-07-01

On UT 2008 July 23.33, P60-FasTING (Palomar 60-inch Fast Transients In Nearby Galaxies) discovered a faint optical transient in M31 at RA(J2000)=00:43:27.28, DEC(J2000) = +41:10:03.3. P60-M31-080723 has a brightness of g = 19.3 +/- 0.2 (photometric calibration wrt USNO-B) and it is offset by 8.1'E,6.1'S from the center of M31. It was also marginally detected on July 22.32 at g = 19.8 +/- 0.2. It was not detected on the previous several nights with 3-sigma upper limits in table below.

Transient thermal camouflage and heat signature control

NASA Astrophysics Data System (ADS)

Yang, Tian-Zhi; Su, Yishu; Xu, Weikai; Yang, Xiao-Dong

2016-09-01

Thermal metamaterials have been proposed to manipulate heat flux as a new way to cloak or camouflage objects in the infrared world. To date, however, thermal metamaterials only operate in the steady-state and exhibit detectable, transient heat signatures. In this letter, the theoretical basis for a thermal camouflaging technique with controlled transient diffusion is presented. This technique renders an object invisible in real time. More importantly, the thermal camouflaging device instantaneously generates a pre-designed heat signature and behaves as a perfect thermal illusion device. A metamaterial coating with homogeneous and isotropic thermal conductivity, density, and volumetric heat capacity was fabricated and very good camouflaging performance was achieved.

Acute transient hemiparesis induced by lightning strike.

PubMed

Rahmani, Seyed Hesam; Faridaalaee, Gholamreza; Jahangard, Samira

2015-07-01

According to data from the National Oceanic and Atmospheric Administration,in the years from 1959 to 1994, lightning was responsible for more than 3000 deaths and nearly 10,000 casualties. The most important characteristic features of lightning injuries are multisystem involvement and widely variable severity. Lightning strikes are primarily a neurologic injury that affects all 3 components of the nervous system: central, autonomic,and peripheral. Neurologic complications of lightning strikes vary from transient benign symptoms to permanent disability. Many patients experience a temporary paralysis called keraunoparalysis. Here we reported a 22-year-old mountaineer man with complaining of left sided hemiparesis after being hit by a lightning strike in the mountain 3 hours ago. There was no loss of consciousness at hitting time. On arrival the patient was alert, awake and hemodynamically stable. In neurologic examination cranial nerves were intact, left sided upper and lower extremity muscle force was I/V with a combination of complete sensory loss, and right-sided muscle force and sensory examination were normal. There is not any evidence of significant vascular impairment in the affected extremities. Brain MRI and CT scan and cervical MRI were normal. During 2 days of admission, with intravenous hydration, heparin 5000 unit SC q12hr and physical therapy of the affected limbs, motor and sensory function improved and was normal except mild paresthesia. He was discharged 1 day later for outpatient follow up while vitamin B1 100mg orally was prescribed.Paresthesia improved after 3 days without further sequels.

Investigation of the cardiomyocyte dysfunction in bradykinin type 2 receptor knockout mice.

PubMed

Roman-Campos, Danilo; Duarte, Hugo Leonardo; Gomes, Enéas Ricardo; Castro, Carlos Henrique; Guatimosim, Silvia; Natali, Antonio José; Almeida, Alvair Pinto; Pesquero, João Bosco; Pesquero, Jorge Luiz; Cruz, Jader Santos

2010-12-18

Bradykinin type 2 receptor (B(2)R) is the key component to trigger the intracellular signaling pathway in response to bradykinin under physiological conditions. The present study sought to investigate whether the B(2)R gene deletion will have an impact on myocardial function. Isolated cell shortening, patch-clamp technique, Western blot and confocal microscopy. Isolated cell shortening measurements showed significant reduction in B(2)R knockout (B(2)R(-/-)) left ventricular cardiac myocytes' shortening. Whole-cell recordings were used to study the electrophysiological aspects of the left ventricular B(2)R(-/-) cardiomyocytes. Results showed: 1) action potential lengthening; 2) unchanged inwardly rectifying K(+) current; 3) reduced transient outward K(+) (I(to)) and L-type Ca(2+) current densities; 5) changes in kinetic properties related to I(to) and I(Ca,L). In addition, transient sarcoplasmic reticulum (SR) Ca(2+) release was found to be smaller in B(2)R(-/-) cardiomyocytes. Importantly, evidence is provided that NO constitutive production is, at least in part, responsible for the reported electrophysiological modifications observed in cardiomyocytes from B(2)R(-/-) mice. Surprisingly, NO is not involved in the SR Ca(2+) release reduction as demonstrated in the present study. Taken together, our findings indicate that B(2)R plays a fundamental role in the regulation of cardiac function and Ca(2+) homeostasis, probably through a NO dependent pathway. These results may contribute to our understanding of the kinins participation in the control of cardiac function. Copyright © 2010 Elsevier Inc. All rights reserved.

The Corralitos Observatory program for the detection of lunar transient phenomena

NASA Technical Reports Server (NTRS)

Hynek, J. A.; Dunlap, J. R.; Hendry, E. M.

1976-01-01

This is a final report on the establishment, observing procedures, and observational results of a survey program for the detection of lunar transient phenomena (LTP's) by electro-optical image conversion means. For survey, a unique detection system with an image orthicon was used as the primary element in conjunction with a 24-in. f/20 Cassegrainian telescope. Observations in three spectral ranges, with 6,466 man-hours of observing, were actually performed during the period from October 27, 1965, to April 26, 1972. Within this entire period, no color or feature change within the detection capabilities of the instrumentation was observed, either independently or in follow up of amateur LTP reports, with the exception of one general bluing and several localized bluings (probably ascribable to the effects of the terrestrial atmosphere) that were observed solely by the Corralitos system. A table is presented indicating amateur and professional reports of LTP's and the results of efforts to confirm these reports through the Corralitos system.

Systemic Staphylococcus pseudintermedius infection in an arctic fox (Vulpes lagopus) with severe multifocal suppurative meningoencephalitis and nephritis.

PubMed

Iwata, Kei; Kasuya, Kazufumi; Takayama, Kou; Nakahara, Yusuke; Kobayashi, Yoshifumi; Kato, Asako; Senba, Hironobu; Yanagisawa, Masae; Shibahara, Tomoyuki

2018-06-11

A 2-year-female arctic fox (Vulpes lagopus) developed anorexia, dehydration, and emaciation during the quarantine period for importation from Norway, and died 17 days later. At necropsy, a fistula was observed on the left gluteal region, and the left eye, left brain, and kidneys were discolored. Histologically, severe diffuse suppurative meningoencephalitis and renal abscesses were detected. Numerous Gram-positive cocci were detected in these lesions. Multidrug-susceptible Staphylococcus pseudintermedius were isolated from the lesions. These results suggest that S. pseudintermedius can cause severe multifocal suppurative meningoencephalitis and nephritis in foxes. This is the first report of multidrug-susceptible S. pseudintermedius meningoencephalitis and nephritis in a fox.

New Southern Cataclysmic Variables: Discoveries from MASTER-SAAO

NASA Astrophysics Data System (ADS)

Buckley, D. A. H.; Potter, S. B.; Kniazev, A.; Lipunov, V.; Gorbovskoy, E.; Tiurina, N.

2017-03-01

In this paper we report on new cataclysmic variables (CVs) discovered by the first local optical transient detection system established at the SAAO Sutherland station, namely MASTER-SAAO. The characteristics of the MASTER-SAAO system are described and the parameters of the survey compared to the Catalina Real Time Survey (CRTS). To date MASTER-SAAO has discovered over 200 (non-Solar System) optical transients with about 75% of these being likely new CVs, most being dwarf novae (DNe). Approximately 50% of the DNe have outburst amplitudes in excess of 4 magnitudes, with some extreme amplitude (> 7 mag), probable WZ Sge systems. The MASTER-SAAO detection limit of B = 19-20 is comparable to the ˜20 magnitude limit of the CRTS (depending on CV colour). Based on the CV detection statistics of CRTS, we believe that MASTER-SAAO is detecting essentially the same CV population as CRTS, for a detection outburst amplitude threshold >2.2 magnitudes. We also present results of the initial follow-up program on CVs discovered by MASTER, including dwarf novae, a bright new VY Scl system and a new eclipsing polar.

Enhancing Continuous Online Microdialysis Using Dexamethasone: Measurement of Dynamic Neurometabolic Changes during Spreading Depolarization.

PubMed

Varner, Erika L; Leong, Chi Leng; Jaquins-Gerstl, Andrea; Nesbitt, Kathryn M; Boutelle, Martyn G; Michael, Adrian C

2017-08-16

Microdialysis is well established in chemical neuroscience as a mainstay technology for real time intracranial chemical monitoring in both animal models and human patients. Evidence shows that microdialysis can be enhanced by mitigating the penetration injury caused during the insertion of microdialysis probes into brain tissue. Herein, we show that retrodialysis of dexamethasone in the rat cortex enhances the microdialysis detection of K + and glucose transients induced by spreading depolarization. Without dexamethasone, quantification of glucose transients was unreliable by 5 days after probe insertion. With dexamethasone, robust K + and glucose transients were readily quantified at 2 h, 5 days, and 10 days after probe insertion. The amplitudes of the K + transients declined day-to-day following probe insertion, and the amplitudes of the glucose transients exhibited a decreasing trend that did not reach statistical significance. Immunohistochemistry and fluorescence microscopy confirm that dexamethasone is highly effective at preserving a healthy probe-brain interface for at least 10 days even though retrodialysis of dexamethasone ceased after 5 days.

Real-time Automatic Search for Multi-wavelength Counterparts of DWF Transients

NASA Astrophysics Data System (ADS)

Murphy, Christopher; Cucchiara, Antonino; Andreoni, Igor; Cooke, Jeff; Hegarty, Sarah

2018-01-01

The Deeper Wider Faster (DWF) survey aims to find and classify the fastest transients in the Universe. DWF utilizes the Dark Energy Camera (DECam), collecting a continuous sequence of 20s images over a 3 square degree field of view.Once an interesting transient is detected during DWF observations, the DWF collaboration has access to several facilities for rapid follow-up in multiple wavelengths (from gamma to radio).An online web tool has been designed to help with real-time visual classification of possible astrophysical transients in data collected by the DWF observing program. The goal of this project is to create a python-based code to improve the classification process by querying several existing archive databases. Given the DWF transient location and search radius, the developed code will extract a list of possible counterparts and all available information (e.g. magnitude, radio fluxes, distance separation).Thanks to this tool, the human classifier can make a quicker decision in order to trigger the collaboration rapid-response resources.

Left-Sided Catamenial Pneumothorax with Thoracic Endometriosis and Bullae in the Alveolar Wall

PubMed Central

Takahashi, Ryo; Mizobuchi, Teruaki; Ebana, Hiroki; Yamanaka, Sumitaka

2016-01-01

Catamenial pneumothorax (CP) is generally caused by intraperitoneal air leaking from the uterus into the thoracic cavity via a defect in the endometrial tissue of the diaphragm and is usually detected in the right thorax. We report a case of left-sided CP caused by endometriosis in the visceral pleura and with no abnormal findings in the diaphragm. A 33-year-old female patient presented at the end of a course of low-dose contraceptive pills for pelvic endometriosis, with spontaneous pneumothorax in the left chest. Chest CT revealed a bulla in the left upper lung lobe. The patient underwent partial resection of the lung. Immunohistochemistry confirmed the presence of endometrial stromal tissue in the visceral pleura and confirmed this as the cause of pneumothorax since there were no observable abnormalities in the diaphragm. This case suggests that immunohistochemical examination of patients with spontaneous pneumothorax can detect alternative endometrial lesions. PMID:27507105

Left-Sided Catamenial Pneumothorax with Thoracic Endometriosis and Bullae in the Alveolar Wall.

PubMed

Takahashi, Ryo; Kurihara, Masatoshi; Mizobuchi, Teruaki; Ebana, Hiroki; Yamanaka, Sumitaka

2017-04-20

Catamenial pneumothorax (CP) is generally caused by intraperitoneal air leaking from the uterus into the thoracic cavity via a defect in the endometrial tissue of the diaphragm and is usually detected in the right thorax. We report a case of left-sided CP caused by endometriosis in the visceral pleura and with no abnormal findings in the diaphragm. A 33-year-old female patient presented at the end of a course of low-dose contraceptive pills for pelvic endometriosis, with spontaneous pneumothorax in the left chest. Chest CT revealed a bulla in the left upper lung lobe. The patient underwent partial resection of the lung. Immunohistochemistry confirmed the presence of endometrial stromal tissue in the visceral pleura and confirmed this as the cause of pneumothorax since there were no observable abnormalities in the diaphragm. This case suggests that immunohistochemical examination of patients with spontaneous pneumothorax can detect alternative endometrial lesions.

Salient features of the ciliated organ of asymmetry

PubMed Central

Amack, Jeffrey D.

2014-01-01

Many internal organs develop distinct left and right sides that are essential for their functions. In several vertebrate embryos, motile cilia generate an asymmetric fluid flow that plays an important role in establishing left-right (LR) signaling cascades. These ‘LR cilia’ are found in the ventral node and posterior notochordal plate in mammals, the gastrocoel roof plate in amphibians and Kupffer’s vesicle in teleost fish. I consider these transient ciliated structures as the ‘organ of asymmetry’ that directs LR patterning of the developing embryo. Variations in size and morphology of the organ of asymmetry in different vertebrate species have raised questions regarding the fundamental features that are required for LR determination. Here, I review current models for how LR asymmetry is established in vertebrates, discuss the cellular architecture of the ciliated organ of asymmetry and then propose key features of this organ that are critical for orienting the LR body axis. PMID:24481178

Sweet Chestnut (Castanea sativa Mill.) Bark Extract: Cardiovascular Activity and Myocyte Protection against Oxidative Damage

PubMed Central

Chiarini, Alberto; Micucci, Matteo; Ioan, Pierfranco; Fimognari, Carmela; Gallina Toschi, Tullia; Comandini, Patrizia; Hrelia, Silvana

2013-01-01

This work was aimed at evaluating the cardioprotective effects of Castanea sativa Mill. (CSM) bark extract characterized in its phenolic composition by HPLC-DAD-MS analysis. The study was performed using primary cultures of neonatal rat cardiomyocytes to investigate the antioxidant and cytoprotective effects of CSM bark extract and isolated guinea pig left and right atria, left papillary muscle, and aorta to evaluate its direct effect on cholinergic and adrenergic response. In cultured cardiomyocytes the CSM bark extract reduced intracellular reactive oxygen species formation and improved cell viability following oxidative stress in dose-dependent manner. Moreover, the extract decreased the contraction induced by noradrenaline (1 μM) in guinea pig aortic strips and induced transient negative chronotropic and positive inotropic effects without involvement of cholinergic or adrenergic receptors in the guinea pig atria. Our results indicate that CSM bark extract exhibits antioxidant activity and might induce cardioprotective effect. PMID:23533692

Transient right-to-left shunt in massive pulmonary embolism.

PubMed

Panoutsopoulos, G; Ilias, L; Christakopoulou, I

2000-06-01

A 56-yr-old man, two months after an operation for an acoustic neurinoma, gradually developed dyspnea. Massive pulmonary embolism (MPE), with a significant right-to-left (R-L) shunt, was seen in a perfusion scan of the lungs with Tc-99m MAA. Radioactivity was noted in the thyroid, spleen, kidneys and brain. A cardiac ultrasound study did not reveal intracardiac shunting. A few days later, when the patient's condition improved, another perfusion scan of the lungs did not show the shunt, whereas a subsequent digital subtraction angiographic study confirmed the diagnosis of MPE but failed to reveal the cause of the shunt. In the absence of any possible pathophysiological mechanism, to explain the observed R-L shunt, we deduce that the particles of Tc-99m MAA might have passed through the precapillary pulmonary arteriovenous anastomoses and/or through dilated pulmonary capillaries, as a result of highly increased pulmonary vascular pressure due to MPE.

Late myocardial ischemia with ST-segment elevation after negative dobutamine stress echocardiography in a patient with normal coronary arteries.

PubMed

Cabani, Enrico; Lattanzi, Fabio; Paci, Anna Maria; Pieroni, Andrea; Baria, Luca; Tommasi, Salvatore Mario De

2009-04-01

Late complications after pharmacological stress echocardiography are infrequent but potentially dreadful events. We report the case of a 80-year-old woman admitted to hospital for rest chest pain with trivial troponin increase, normal left ventricular function and no significant ECG changes. A dobutamine stress echocardiography was performed for diagnostic purpose, with a negative result. About 30 min after the end of dobutamine infusion, she developed ST-segment elevation in inferior leads associated with chest pain and left ventricular dyssynergy, promptly resolved by sublingual nitrates. Subsequently, angiography documented the absence of significant coronary stenoses. The following clinical course was uneventful. Transient myocardial ischemia was likely due to dobutamine-induced coronary spasm. The case emphasizes the utility of routine, long-lasting monitoring of patients after stress echocardiography, even if negative, to counteract possible late life-threatening complications.

Localization of spontaneous bursting neuronal activity in the preterm human brain with simultaneous EEG-fMRI.

PubMed

Arichi, Tomoki; Whitehead, Kimberley; Barone, Giovanni; Pressler, Ronit; Padormo, Francesco; Edwards, A David; Fabrizi, Lorenzo

2017-09-12

Electroencephalographic recordings from the developing human brain are characterized by spontaneous neuronal bursts, the most common of which is the delta brush. Although similar events in animal models are known to occur in areas of immature cortex and drive their development, their origin in humans has not yet been identified. Here, we use simultaneous EEG-fMRI to localise the source of delta brush events in 10 preterm infants aged 32-36 postmenstrual weeks. The most frequent patterns were left and right posterior-temporal delta brushes which were associated in the left hemisphere with ipsilateral BOLD activation in the insula only; and in the right hemisphere in both the insular and temporal cortices. This direct measure of neural and hemodynamic activity shows that the insula, one of the most densely connected hubs in the developing cortex, is a major source of the transient bursting events that are critical for brain maturation.

VLITE-Fast: A Real-time, 350 MHz Commensal VLA Survey for Fast Transients

NASA Astrophysics Data System (ADS)

Kerr, Matthew; Ray, Paul S.; Kassim, Namir E.; Clarke, Tracy; Deneva, Julia; Polisensky, Emil

2018-01-01

The VLITE (VLA Low Band Ionosphere and Transient Experiment; http://vlite.nrao.edu) program operates commensally during all Very Large Array observations, collecting data from 320 to 384 MHz. Recently expanded to include 16 antennas, the large field of view and huge time on sky offer good coverage of the transient, low-frequency sky. We describe the VLITE-Fast system, a GPU-based signal processor capable of detecting short (<1s) transients in real time and triggering recording of baseband voltage for offline imaging. In the case of Fast Radio Bursts, this offers the opportunity for discovering host galaxies of non-repeating FRBs, and in the case of single pulses, the identification of pulsar positions for dedicated follow-up. We describe the observing system, techniques for mitigating interference, and initial results from searches for FRBs.

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

Espinosa-Paredes, Gilberto; Prieto-Guerrero, Alfonso; Nunez-Carrera, Alejandro

This paper introduces a wavelet-based method to analyze instability events in a boiling water reactor (BWR) during transient phenomena. The methodology to analyze BWR signals includes the following: (a) the short-time Fourier transform (STFT) analysis, (b) decomposition using the continuous wavelet transform (CWT), and (c) application of multiresolution analysis (MRA) using discrete wavelet transform (DWT). STFT analysis permits the study, in time, of the spectral content of analyzed signals. The CWT provides information about ruptures, discontinuities, and fractal behavior. To detect these important features in the signal, a mother wavelet has to be chosen and applied at several scales tomore » obtain optimum results. MRA allows fast implementation of the DWT. Features like important frequencies, discontinuities, and transients can be detected with analysis at different levels of detail coefficients. The STFT was used to provide a comparison between a classic method and the wavelet-based method. The damping ratio, which is an important stability parameter, was calculated as a function of time. The transient behavior can be detected by analyzing the maximum contained in detail coefficients at different levels in the signal decomposition. This method allows analysis of both stationary signals and highly nonstationary signals in the timescale plane. This methodology has been tested with the benchmark power instability event of Laguna Verde nuclear power plant (NPP) Unit 1, which is a BWR-5 NPP.« less

Single-Molecule Counting of Point Mutations by Transient DNA Binding

NASA Astrophysics Data System (ADS)

Su, Xin; Li, Lidan; Wang, Shanshan; Hao, Dandan; Wang, Lei; Yu, Changyuan

2017-03-01

High-confidence detection of point mutations is important for disease diagnosis and clinical practice. Hybridization probes are extensively used, but are hindered by their poor single-nucleotide selectivity. Shortening the length of DNA hybridization probes weakens the stability of the probe-target duplex, leading to transient binding between complementary sequences. The kinetics of probe-target binding events are highly dependent on the number of complementary base pairs. Here, we present a single-molecule assay for point mutation detection based on transient DNA binding and use of total internal reflection fluorescence microscopy. Statistical analysis of single-molecule kinetics enabled us to effectively discriminate between wild type DNA sequences and single-nucleotide variants at the single-molecule level. A higher single-nucleotide discrimination is achieved than in our previous work by optimizing the assay conditions, which is guided by statistical modeling of kinetics with a gamma distribution. The KRAS c.34 A mutation can be clearly differentiated from the wild type sequence (KRAS c.34 G) at a relative abundance as low as 0.01% mutant to WT. To demonstrate the feasibility of this method for analysis of clinically relevant biological samples, we used this technology to detect mutations in single-stranded DNA generated from asymmetric RT-PCR of mRNA from two cancer cell lines.

Global transients in ultraviolet and red-infrared ranges from data of Universitetsky-Tatiana-2 satellite

NASA Astrophysics Data System (ADS)

Garipov, G. K.; Khrenov, B. A.; Klimov, P. A.; Klimenko, V. V.; Mareev, E. A.; Martines, O.; Mendoza, E.; Morozenko, V. S.; Panasyuk, M. I.; Park, I. H.; Ponce, E.; Rivera, L.; Salazar, H.; Tulupov, V. I.; Vedenkin, N. N.; Yashin, I. V.

2013-01-01

Light detectors sensitive to wavelength ranges 240-400 nm and beyond 610 nm (which we refer to, for simplicity, as the UV and Red bands) on board Universitetsky-Tatiana-2 satellite have detected transient flashes in the atmosphere of duration 1-128 ms. Measured ratio of the number of Red photons to the number of UV photons indicates that source of transient radiation is at high atmosphere altitude (>50 km). Distribution of events with various photon numbers Qa in the atmosphere found to be different for "luminous" events Qa = 1023 - 1026 (with exponent of differential distribution -2.2) and for "faint" events Qa = 1021 - 1023 (with exponent - 0.97). Luminous event parameters (atmosphere altitude, energy released to radiation, and temporal profiles) are similar to observed elsewhere parameters of transient luminous events (TLE) of elves, sprites, halo, and gigantic blue jets types. Global map of luminous events demonstrates concentration to equatorial zones (latitudes 30°N to 30°S) above continents. Faint events (with number of photons Qa = 1020 - 5ṡ 1021) are distributed more uniformly over latitudes and longitudes. Phenomenon of series of transients registered every minute along satellite orbit (from 3 to 16 transients in one series) was observed. Most TLE-type events belonged to series. Single transients are in average fainter than serial ones. Some transients belonging to series occurs far away of thunderstorm regions. Origin of faint single transients is not clear; several hypothetical models of their production are discussed.

Transesophageal Echocardiography and Contrast-TCD in the Detection of a Patent Foramen Ovale: Experience with 111 Patients

NASA Technical Reports Server (NTRS)

Klotzsch, Christof; Janben, Gerhard; Berlit, Peter

1994-01-01

Patent foramen ovale (PFO) is increasingly recognized in association with cryptogenic stroke. Using transesophageal echocardiography (TEE) and transcranial Doppler sonography with ultrasonic contrast medium contrast-(TCD), we evaluated the frequency of a PFO as the fundamental condition of paradoxical embolism in 111 patients after cerebral ischemia. There was a right-left shunt in 50 patients (45%) with TEE. In 31 of 40 patients with stroke of unknown etiology, a PFO was the only detectable finding associated with cerebral ischemia. Using TEE as he "gold standard," the sensitivity of contrast-TCD was 91.3%, specificity 93.8%, and the overall accuracy 92.8%. contrast-TCD failed to detect a right-left shunt in four patients, but there were four other patients with negative TEE and positive contrast-TCD. We conclude that contrast-TCD is a highly sensitive method for detecting a right-left shunt. Its advantages are low cost, its ability to detect single contrast-medium embolism, and control of the Valsalva maneuver by observing the decrease of cerebral blood flow. Evidence of PFO in cryptogenic stroke should prompt a search for a subclinical venous thrombosis as the embolic source.

Right-to-left-shunt detected by c-TCD using the orbital window in comparison with temporal bone windows.

PubMed

Kobayashi, Kazuto; Kimura, Kazumi; Iguchi, Yasuyuki; Sakai, Kenichirou; Aoki, Junya; Iwanaga, Takeshi; Shibazaki, Kensaku

2012-01-01

There have been some reports on right-to-left shunt as a cause of cryptogenic stroke. Although contrast transcranial Doppler (c-TCD) can detect RLS, an insufficient temporal window has occasionally restricted its applicability. Thus, we compared the rates of detecting RLS among temporal windows for the middle cerebral arteries (MCAs) and the orbital window for the internal carotid artery (ICA) on c-TCD. We used c-TCD to detect RLS in patients with suspected ischemic stroke. We enrolled patients who had both sufficient bilateral temporal windows for MCAs and a right orbital window for ICA and performed c-TCD using all three windows simultaneously. We enrolled 106 consecutive patients and identified microembolic signals (MES) in 30 (28%) of them. Among these 30 patients, 15 had MES from all 3 windows. When these 30 patients were defined as being positive for RLS, the rates of detection were 67%, 73%, and 80% from the right temporal, left temporal, and right orbital windows, respectively (P= .795). The right orbital window as well as the temporal window for c-TCD could detect RLS. Insonation from the orbital window should be useful for patients who lack temporal windows. Copyright © 2010 by the American Society of Neuroimaging.

Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch

PubMed Central

Behroozmand, Roozbeh; Ibrahim, Nadine; Korzyukov, Oleg; Robin, Donald A.; Larson, Charles R.

2014-01-01

The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing. PMID:24355545

Detection of an epidermoid cyst in the foot of a horse by use of magnetic resonance imaging.

PubMed

Sanz, Macarena G; Sampson, Sarah N; Schneider, Robert K; Gavin, Patrick R; Baszler, Timothy V

2006-06-15

CASE DESCRIPTION-A 4-year-old Quarter Horse stallion was evaluated because of a 10-month history of moderate (grade 3/5) left forelimb lameness (detectable during trotting over a smooth, hard surface). CLINICAL FINDINGS-No abnormalities were detected in either forelimb via palpation or application of hoof testers; however, lameness was eliminated after administration of a palmar digital nerve block in the left forelimb. Whereas radiography and ultrasonography did not identify any left forelimb foot abnormalities, magnetic resonance (MR) imaging revealed a circumscribed soft tissue mass in the distal aspect of the digital flexor tendon sheath (DFTS) dorsal to the lateral aspect of the deep digital flexor tendon. Subsequently, the left forelimb DFTS was injected with local anesthetic, which resulted in 90% improvement of the horse's lameness. TREATMENT AND OUTCOME-The distal aspect of the left forelimb DFTS was evaluated tenoscopically. The mass was removed under tenoscopic guidance, after which the distal digital annular ligament was transected. The horse received phenylbutazone orally for 10 days, and the left forelimb DFTS was injected with hyaluronic acid and methylprednisolone acetate 7 days after the surgery. Following a rehabilitation program, the horse was returned to full training at 6 months after surgery and competed successfully during a 2-year follow-up period. CLINICAL RELEVANCE-Use of MR imaging should be considered in all lame horses for which a definitive diagnosis cannot be made via radiography, ultrasonography, or other imaging techniques, especially when the lameness has been localized to a specific anatomic region by use of diagnostic anesthesia.

Influence of presenting electrocardiographic findings on the treatment and outcomes of patients with non-ST-segment elevation myocardial infarction.

PubMed

Patel, Jigar H; Gupta, Raghav; Roe, Matthew T; Peng, S Andrew; Wiviott, Stephen D; Saucedo, Jorge F

2014-01-15

The influence of the presenting electrocardiographic (ECG) findings on the treatment and outcomes of patients with non-ST-segment elevation myocardial infarction (NSTEMI) has not been studied in contemporary practice. We analyzed the clinical characteristics, in-hospital management, and in-hospital outcomes of patients with NSTEMI in the Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines (ACTION Registry-GWTG) according to the presenting ECG findings. A total of 175,556 patients from 485 sites from January 2007 to September 2011 were stratified by the ECG findings on presentation: ST depression (n = 40,146, 22.9%), T-wave inversions (n = 24,627, 14%), transient ST-segment elevation (n = 5,050, 2.9%), and no ischemic changes (n = 105,733, 60.2%). Patients presenting with ST-segment depression were the oldest and had the greatest prevalence of major cardiac risk factors. Coronary angiography was performed most frequently in the transient ST-segment elevation group, followed by the T-wave inversion, ST-segment depression, and no ischemic changes groups. The angiogram revealed that patients with ST-segment depression had more left main, proximal left anterior descending, and 3-vessel coronary artery disease and underwent coronary artery bypass grafting most often. In contrast, patients with transient ST-segment elevation had 1-vessel CAD and underwent percutaneous coronary intervention the most. The unadjusted mortality was highest in the ST-segment depression group, followed by the no ischemic changes, transient ST-segment elevation, and T-wave inversion group. Adjusted mortality using the ACTION Registry-GWTG in-hospital mortality model with the no ischemic changes group as the reference showed that in-hospital mortality was similar in the transient ST-segment elevation (odds ratio 1.15, 95% confidence interval 0.97 to 1.37; p = 0.10), higher in the ST-segment depression group (odds ratio 1.46, 95% confidence interval 1.37 to 1.54; p <0.0001), and lower in the T-wave inversion group (odds ratio 0.91, 95% confidence interval 0.83 to 0.99; p = 0.026). In conclusion, the clinical and angiographic characteristics and treatment and outcomes of patients with NSTEMI differed substantially according to the presenting ECG findings. Patients with ST-segment depression have a greater burden of co-morbidities and coronary atherosclerosis and have a greater risk of adjusted in-hospital mortality compared with the other groups. These findings highlight the importance of integrating the presenting ECG findings into the risk stratification algorithm for patients with NSTEMI. Copyright © 2014 Elsevier Inc. All rights reserved.

Theoretical Models of Optical Transients. I. A Broad Exploration of the Duration-Luminosity Phase Space

NASA Astrophysics Data System (ADS)

Villar, V. Ashley; Berger, Edo; Metzger, Brian D.; Guillochon, James

2017-11-01

The duration-luminosity phase space (DLPS) of optical transients is used, mostly heuristically, to compare various classes of transient events, to explore the origin of new transients, and to influence optical survey observing strategies. For example, several observational searches have been guided by intriguing voids and gaps in this phase space. However, we should ask, do we expect to find transients in these voids given our understanding of the various heating sources operating in astrophysical transients? In this work, we explore a broad range of theoretical models and empirical relations to generate optical light curves and to populate the DLPS. We explore transients powered by adiabatic expansion, radioactive decay, magnetar spin-down, and circumstellar interaction. For each heating source, we provide a concise summary of the basic physical processes, a physically motivated choice of model parameter ranges, an overall summary of the resulting light curves and their occupied range in the DLPS, and how the various model input parameters affect the light curves. We specifically explore the key voids discussed in the literature: the intermediate-luminosity gap between classical novae and supernovae, and short-duration transients (≲ 10 days). We find that few physical models lead to transients that occupy these voids. Moreover, we find that only relativistic expansion can produce fast and luminous transients, while for all other heating sources events with durations ≲ 10 days are dim ({M}{{R}}≳ -15 mag). Finally, we explore the detection potential of optical surveys (e.g., Large Synoptic Survey Telescope) in the DLPS and quantify the notion that short-duration and dim transients are exponentially more difficult to discover in untargeted surveys.

Relation of Coronary Flow Reserve to Other Findings on Positron Emission Tomography Myocardial Perfusion Imaging and Left Heart Catheterization in Patients With End-stage Renal Disease Being Evaluated for Kidney Transplant.

PubMed

Paz, Yehuda; Morgenstern, Rachelle; Weinberg, Richard; Chiles, Mariana; Bhatti, Navdeep; Ali, Ziad; Mohan, Sumit; Bokhari, Sabahat

2017-12-01

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD) and often goes undetected. Abnormal coronary flow reserve (CFR), which predicts increased risk of cardiac death, may be present in patients with ESRD without other evidence of coronary artery disease (CAD). We prospectively studied 131 patients who had rest and dipyridamole pharmacologic stress N 13 -ammonia positron emission tomography myocardial perfusion imaging (PET MPI) for kidney transplant evaluation. Thirty-four patients also had left heart catheterization. Abnormal PET MPI was defined as qualitative ischemia or infarct, stress electrocardiogram ischemia, or transient ischemic dilation. CFR was calculated as the ratio of stress to rest coronary blood flow. Global CFR < 2 was defined as abnormal. Of 131 patients who had PET MPI (66% male, 55.6 ± 12.1 years), 30% (39 of 131) had abnormal PET MPI and 59% (77 of 131) had abnormal CFR. In a subset of 34 patients who had left heart catheterization (66% male, 61.0 ± 12.1 years), 68% (23 of 34) had abnormal CFR on PET MPI, and 68% (23 of 34) had ≥70% obstruction on left heart catheterization. Abnormal CFR was not significantly associated with abnormal PET MPI (p = 0.13) or obstructive CAD on left heart catheterization (p = 0.26). In conclusion, in the first prospective study of PET MPI in patients with ESRD, abnormal CFR is highly prevalent and is independent of abnormal findings on PET MPI or obstructive CAD on left heart catheterization. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of unilatral- and bilateral inhibition of rostral ventral tegmental area and central nucleus of amygdala on morphine-induced place conditioning in male Wistar rat.

PubMed

Mohammadian, Zahra; Sahraei, Hedayat; Meftahi, Gholam Hossein; Ali-Beik, Hengameh

2017-03-01

The rostral ventral tegmental area (VTAR) and central nucleus of amygdala (CeA) are considered the main regions for induction of psychological dependence on abused drugs, such as morphine. The main aim of this study was to investigate the transient inhibition of each right and left side as well as both sides of the VTAR and the CeA by lidocaine (2%) on morphine reward properties using the conditioned place preference (CPP) method. Male Wistar rats (250±20 g) 7 days after recovery from surgery and cannulation were conditioned to morphine (7.5 mg/kg) in CPP apparatus. Five minutes before morphine injection in conditioning phase, lidocaine was administered either uni- or bilaterally into the VTAR (0.25 μL/site) or CeA (0.5 μL/site). The results revealed that lidocaine administration into the left side, but not the right side of the VTAR and the CeA reduced morphine CPP significantly. The reduction was potentiated when lidocaine was injected into both sides of the VTAR and the CeA. The number of compartment crossings was reduced when lidocaine was injected into both sides of the VTAR and the CeA as well as the left side. Rearing was reduced when lidocaine was injected into the right, but not the left side of the VTAR. Sniffing and rearing increased when animals received lidocaine in the right side and reduced in the group that received lidocaine in the left side of the CeA. It was concluded that the right and the left side of VTAR and the CeA play different roles in morphine-induced activity and reward. © 2016 John Wiley & Sons Australia, Ltd.

A long-lasting improvement of tactile extinction after galvanic vestibular stimulation: two Sham-stimulation controlled case studies.

PubMed

Kerkhoff, Georg; Hildebrandt, Helmut; Reinhart, Stefan; Kardinal, Mareike; Dimova, Violeta; Utz, Kathrin S

2011-01-01

Sensory extinction is frequent and often persistent after brain damage. Previous studies have shown the transient influence of sensory stimulation on tactile extinction. In the present two case studies we investigated whether subliminal galvanic vestibular stimulation (GVS) modulates tactile extinction. GVS induces polarity-specific changes in cerebral excitability in the vestibular cortices and adjacent cortical areas in the temporo-parietal cortex via polarization of the vestibular nerves. Two patients (DL, CJ) with left-sided tactile extinction due to chronic (5 vs. 6 (1/2) years lesion age) right-hemisphere lesions (right fronto-parietal in DL, right frontal and discrete parietal in CJ) were examined. Both showed normal tactile sensitivity to light touch and yielded 90-100% correct identifications in unilateral tactile stimulations for both hands. In Baseline investigations without GVS and Sham-GVS both showed stable left-sided tactile extinction rates of 40-55% (DL) and 49-72% (CJ). In contrast, one session of right-cathodal GVS (intensity: 0.6 mA, duration: 20 min) permanently improved tactile identification of identical stimuli, while a second session with left-cathodal GVS significantly reduced left-sided extinction rates for different stimuli in DL. Patient CJ's left-sided tactile extinction was significantly improved by left-cathodal GVS (0.5 mA, 20 min) for different stimuli, while right-cathodal GVS induced a significant reduction for identical materials. In contrast, Sham-stimulation was ineffective. Improvements remained stable for at least 1 year (DL) resp. 3 weeks (CJ). Control experiments ruled out improvements in tactile extinction merely by retesting. In conclusion, chronic tactile extinction may be permanently improved by GVS in a polarity-specific way. Copyright © 2010 Elsevier Ltd. All rights reserved.

Possible role of magnetic reconnection in the electromagnetic counterpart of binary black hole merger

NASA Astrophysics Data System (ADS)

Fraschetti, F.

2018-04-01

We propose a qualitative scenario to interpret the argued association between the direct measurement of the gravitational wave event GW150914 by Laser Interferometer Gravitational Wave Observatory (LIGO)-Virgo collaborations and the hard X-ray transient detected by Fermi-Gamma-ray Burst Monitor (GBM) 0.4 sec after. In a binary system of two gravitationally collapsing objects with a non-vanishing electric charge, the compenetration of the two magnetospheres occurring during the coalescence, through magnetic reconnection, produces a highly collimated relativistic outflow that becomes optically thin and shines in the GBM field of view. We propose that this process should be expected as a commonplace in the future joint gravitational/electromagnetic detections and, in case of neutron star-neutron star merger event, might lead to detectable X- or γ-ray precursors to, or transients associated with, the gravitational bursts.

Detection of Helicobacter pylori by Real-Time PCR for 16s rRNA in Stools of NonInfected Healthy Children, Using ELISA Antigen Stool Test as the Gold Standard.

PubMed

George, Sergio; Mamani, Nora; Lucero, Yalda; Torres, Juan Pablo; Farfán, Mauricio; Lagomarcino, Anne J; Orellana, Andrea; O'Ryan, Miguel

2016-12-01

We previously detected Helicobacter pylori infection by stool antigen ELISA assay in 33-41% of asymptomatic Chilean children between 2-3 years of age, of which 11-20% had a transient infection and 21-22% a persistent infection. A total of 88% of ELISA-positive samples were also rtPCR positive, while 37/133 (33%) of ELISA-negative stool samples were rtPCR positive. The significance of a ELISA-negative/rtPCR-positive sample requires clarification. We aimed to determine whether rtPCR is able to detect persistent infections not detected by ELISA. We selected 36 children with an ELISA-negative/rtPCR-positive stool sample, of which 25 were never H. pylori infected according to ELISA, and 11 had a transient infection with an ELISA-positive sample before or after the discordant sample. At least two additional consecutive ELISA-negative samples per child were tested in duplicate by rtPCR for the 16s rRNA gene. A total of 14 of 78 (17.9%) rtPCR reactions were positive, but only 4/78 (5.1%) were positive in both duplicates, representing a total of 3/36 (8.3%) children with an additional rtPCR-positive sample, only one of whom was persistently negative by ELISA. One child with a transient infection had two positive rtPCR reactions despite negative ELISA samples. In H. pylori noninfected or transiently infected children, as determined by stool ELISA, additional ELISA-negative/rtPCR-positive stool samples were found in 8.3% of children, but a possible persistent infection was only identified in 2.7% of children. Thus, the characterization of infection dynamics in children is not being misrepresented by application of stool ELISA. Furthermore, rtPCR does not significantly improve dynamic characterization. © 2016 John Wiley & Sons Ltd.

Usefulness of two- and three-dimensional transesophageal echocardiography in the assessment of proximal left coronary system compression by a paraprosthetic aortic valve abscess.

PubMed

Ahmad, Amier; McElwee, Samuel K; Jiang, Amy Z; Barssoum, Kirolos N; Elkaryoni, Ahmed E; Arisha, Mohammed J; Srialluri, Swetha; Seghatol, Frank; Nanda, Navin C

2017-02-01

Paraprosthetic aortic valve abscess represents a rare, but lethal complication of infective endocarditis. We report a case of proximal left coronary system compression by a paraprosthetic aortic valve abscess whose detection was augmented using live/real time three-dimensional transesophageal echocardiography. Our case illustrates the usefulness of combined two- and three-dimensional transesophageal echocardiography in detecting this finding. © 2017, Wiley Periodicals, Inc.