Increased prevalence of hyperthyroidism as an early and transient side-effect of implementing iodine prophylaxis.

PubMed

Gołkowski, Filip; Buziak-Bereza, Monika; Trofimiuk, Małgorzata; Bałdys-Waligórska, Agata; Szybiński, Zbigniew; Huszno, Bohdan

2007-08-01

To assess the prevalence of hyperthyroidism just after implementation of iodine prophylaxis among adults from an area with iodine deficiency. A total of 1648 adults (age 16 years and older) were sampled from an area of southern Poland during two nationwide epidemiological surveys. Of these, 1424 adults with negative medical history for thyroid disorders qualified for final analysis. The authors compared thyroid dysfunction in participants prior to (1989-1990) and after implementation of iodine prophylaxis (1997-1999). The southern part of Poland. We found an increase in the serum concentration of anti-thyroid microsomal antibodies from 4.9% in the years 1989-1990 to 12.1% after introduction of iodised household salt (P < 0.0001). The prevalence of hyperthyroidism (defined as thyroid-stimulating hormone < 0.4 microU ml- 1) significantly increased in the equivalent period from 4.8 to 6.5% (P = 0.009). We concluded that a sudden rise in iodine intake after implementation of iodine prophylaxis among adults from the area with iodine deficiency may lead to an increase in thyroid autoimmunity and prevalence of hyperthyroidism. Those possible early side-effects appear to be only temporary and are acceptable when compared with the evident benefits of adequate iodine intake.

The Transient High-Energy Sky and Early Universe Surveyor (THESEUS)

NASA Astrophysics Data System (ADS)

Amati, L.; O'Brien, P.; Goetz, D.; Tenzer, C.; Bozzo, E.

2017-10-01

The Transient High Energy Sky and Early Universe Surveyor (THESEUS) is a mission concept developed by a large international collaboration aimed at exploiting Gamma-Ray Bursts for investigating the early Universe. The main scientic objectives of THESEUS, currently under evaluation by ESA within the selection process for next M5 mission, include: investigating the star formation rate and metallicity evolution of the ISM and IGM up to redshift 10, detecting the first generation (pop III) of stars, studying the sources and physics of re-ionization, detecting the faint end of galaxies luminosity function. These goals will be achieved through a unique combination of instruments allowing GRB detection and arcmin localization over a broad FOV (more than 1sr) and an energy band extending from several MeVs down to 0.3 keV with unprecedented sensitivity, as well as on-board prompt (few minutes) follow-up with a 0.7m class IR telescope with both imaging and spectroscopic capabilities. Such instrumentation will also allow THESEUS to perform a monitoring of the X-ray sky with unprecedented sensitivity, which will provide a perfect service and sinergy to next generation multi-wavalength (e.g., E-ELT, SKA, CTA, ATHENA) and multi-messenger (aLIGO, aVIRGO, eLISA, ET, neutrino detectors, ...) facilities.

Estimating the impact of oyster restoration scenarios on transient fish production

USGS Publications Warehouse

McCoy, Elizabeth; Borrett, Stuart R.; LaPeyre, Megan K.; Peterson, Bradley J.

2017-01-01

Oyster reef restoration projects are increasing in number both to enhance oyster density and to retain valuable ecosystem services provided by oyster reefs. Although some oyster restoration projects have demonstrated success by increasing density and biomass of transient fish, it still remains a challenge to quantify the effects of oyster restoration on transient fish communities. We developed a bioenergetics model to assess the impact of selected oyster reef restoration scenarios on associated transient fish species. We used the model to analyze the impact of changes in (1) oyster population carrying capacity; (2) oyster population growth rate; and (3) diet preference of transient fish on oyster reef development and associated transient fish species. Our model results indicate that resident fish biomass is directly affected by oyster restoration and oyster biomass, and oyster restoration can have cascading impacts on transient fish biomass. Furthermore, the results highlight the importance of a favorable oyster population growth rate during early restoration years, as it can lead to rapid increases in mean oyster biomass and biomass of transient fish species. The model also revealed that a transient fish's diet solely dependent on oyster reef-derived prey could limit the biomass of transient fish species, emphasizing the importance of habitat connectivity in estuarine areas to enhance transient fish species biomass. Simple bioenergetics models can be developed to understand the dynamics of a system and make qualitative predictions of management and restoration scenarios.

Overexpression of Forebrain CRH During Early Life Increases Trauma Susceptibility in Adulthood

PubMed Central

Toth, Mate; Flandreau, Elizabeth I; Deslauriers, Jessica; Geyer, Mark A; Mansuy, Isabelle M; Merlo Pich, Emilio; Risbrough, Victoria B

2016-01-01

Although early-life stress is a significant risk factor for developing anxiety disorders, including posttraumatic stress disorder (PTSD), the underlying mechanisms are unclear. Corticotropin releasing hormone (CRH) is disrupted in individuals with PTSD and early-life stress and hence may mediate the effects of early-life stress on PTSD risk. We hypothesized that CRH hyper-signaling in the forebrain during early development is sufficient to increase response to trauma in adulthood. To test this hypothesis, we induced transient, forebrain-specific, CRH overexpression during early-life (pre-puberty, CRHOEdev) in double-mutant mice (Camk2a-rtta2 × tetO-Crh) and tested their behavioral and gene expression responses to the predator stress model of PTSD in adulthood. In one cohort of CRHOEdev exposed and unexposed mice, avoidance and arousal behaviors were examined 7–15 days after exposure to predator stress. In another cohort, gene expression changes in Crhr1, Crhr2, and Fkbp51 in forebrain of CRHOEdev exposed and unexposed mice were examined 7 days after predator stress. CRHOEdev induced robust increases in startle reactivity and reductions in startle inhibition independently of predator stress in both male and female mice. Avoidance behaviors after predator stress were highly dependent on sex and CRHOEdev exposure. Whereas stressed females exhibited robust avoidance responses that were not altered by CRHOEdev, males developed significant avoidance only when exposed to both CRHOEdev and stress. Quantitative real-time-PCR analysis indicated that CRHOEdev unexposed males exhibit significant changes in Crhr2 expression in the amygdala and bed nucleus stria terminalis in response to stress, whereas males exposed to CRHOEdev did not. Similar to CRHOEdev males, females exhibited no significant Crhr2 gene expression changes in response to stress. Cortical Fkbp51 expression was also significantly reduced by stress and CRHOEdev exposure in males, but not in females. These

Adaptive sampling of AEM transients

NASA Astrophysics Data System (ADS)

Di Massa, Domenico; Florio, Giovanni; Viezzoli, Andrea

2016-02-01

This paper focuses on the sampling of the electromagnetic transient as acquired by airborne time-domain electromagnetic (TDEM) systems. Typically, the sampling of the electromagnetic transient is done using a fixed number of gates whose width grows logarithmically (log-gating). The log-gating has two main benefits: improving the signal to noise (S/N) ratio at late times, when the electromagnetic signal has amplitudes equal or lower than the natural background noise, and ensuring a good resolution at the early times. However, as a result of fixed time gates, the conventional log-gating does not consider any geological variations in the surveyed area, nor the possibly varying characteristics of the measured signal. We show, using synthetic models, how a different, flexible sampling scheme can increase the resolution of resistivity models. We propose a new sampling method, which adapts the gating on the base of the slope variations in the electromagnetic (EM) transient. The use of such an alternative sampling scheme aims to get more accurate inverse models by extracting the geoelectrical information from the measured data in an optimal way.

Emerin plays a crucial role in nuclear invagination and in the nuclear calcium transient

PubMed Central

Shimojima, Masaya; Yuasa, Shinsuke; Motoda, Chikaaki; Yozu, Gakuto; Nagai, Toshihiro; Ito, Shogo; Lachmann, Mark; Kashimura, Shin; Takei, Makoto; Kusumoto, Dai; Kunitomi, Akira; Hayashiji, Nozomi; Seki, Tomohisa; Tohyama, Shugo; Hashimoto, Hisayuki; Kodaira, Masaki; Egashira, Toru; Hayashi, Kenshi; Nakanishi, Chiaki; Sakata, Kenji; Yamagishi, Masakazu; Fukuda, Keiichi

2017-01-01

Alteration of the nuclear Ca2+ transient is an early event in cardiac remodeling. Regulation of the nuclear Ca2+ transient is partly independent of the cytosolic Ca2+ transient in cardiomyocytes. One nuclear membrane protein, emerin, is encoded by EMD, and an EMD mutation causes Emery-Dreifuss muscular dystrophy (EDMD). It remains unclear whether emerin is involved in nuclear Ca2+ homeostasis. The aim of this study is to elucidate the role of emerin in rat cardiomyocytes by means of hypertrophic stimuli and in EDMD induced pluripotent stem (iPS) cell-derived cardiomyocytes in terms of nuclear structure and the Ca2+ transient. The cardiac hypertrophic stimuli increased the nuclear area, decreased nuclear invagination, and increased the half-decay time of the nuclear Ca2+ transient in cardiomyocytes. Emd knockdown cardiomyocytes showed similar properties after hypertrophic stimuli. The EDMD-iPS cell-derived cardiomyocytes showed increased nuclear area, decreased nuclear invagination, and increased half-decay time of the nuclear Ca2+ transient. An autopsied heart from a patient with EDMD also showed increased nuclear area and decreased nuclear invagination. These data suggest that Emerin plays a crucial role in nuclear structure and in the nuclear Ca2+ transient. Thus, emerin and the nuclear Ca2+ transient are possible therapeutic targets in heart failure and EDMD. PMID:28290476

Familial transient financial difficulties during infancy and long-term developmental concerns.

PubMed

Ramanathan, S; Balasubramanian, N; Faraone, S V

2017-09-01

Socioeconomic difficulties affect the cognitive and emotional development of children. However, the focus of prior studies has largely been on poverty and material hardship. This study expands on the existing literature by examining the impact of familial transient financial difficulties during infancy on long-term cognitive and behavioral outcomes. The National Longitudinal Surveys of Youth (79) were used to assess the association between a transient drop in family income by 50% or more (called transient income decline or TID) during the first 3 years of life and later-life Peabody Individual Achievement Math and Reading scores and behavior problem index (BPI) scores (N = 8272-17 348; median assessment age = 9 years). A subsample of matched siblings (N = 2049-4238) was examined to tease out maternal and intra-familial effects. Exposure to TID predicted increased total and externalizing BPI scores (std. coefficients of 0.10 and 0.09, respectively, p < 0.01) in the overall sample. Among matched siblings, exposure to TID predicted increased total, externalizing, and internalizing BPI scores (std. coefficients of 0.27, 0.25, and 0.23, respectively, p < 0.01). Familial transient financial difficulties can have long-lasting behavioral effects for infants. The study identifies an early risk factor and at-risk children, thus providing insight into developing early intervention measures for infants to avoid long-term behavioral problems.

Increase of transient lower esophageal sphincter relaxation associated with cascade stomach

PubMed Central

Kawada, Akiyo; Kusano, Motoyasu; Hosaka, Hiroko; Kuribayashi, Shiko; Shimoyama, Yasuyuki; Kawamura, Osamu; Akiyama, Junichi; Yamada, Masanobu; Akuzawa, Masako

2017-01-01

We previously reported that cascade stomach was associated with reflux symptoms and esophagitis. Delayed gastric emptying has been believed to initiate transient lower esophageal sphincter relaxation (TLESR). We hypothesized that cascade stomach may be associated with frequent TLESR with delayed gastric emptying. Eleven subjects with cascade stomach and 11 subjects without cascade stomach were enrolled. Postprandial gastroesophageal manometry and gastric emptying using a continuous 13C breath system were measured simultaneously after a liquid test meal. TLESR events were counted in early period (0–60 min), late period (60–120 min), and total monitoring period. Three parameters of gastric emptying were calculated: the half emptying time, lag time, and gastric emptying coefficient. The median frequency of TLESR events in the cascade stomach and non-cascade stomach groups was 6.0 (median), 4.6 (interquartile range) vs 5.0, 3.0 in the early period, 5.0, 3.2 vs 3.0, 1.8 in the late period, and 10.0, 6.2 vs 8.0, 5.0 in the total monitoring period. TLESR events were significantly more frequent in the cascade stomach group during the late and total monitoring periods. In contrast, gastric emptying parameters showed no significant differences between the two groups. We concluded that TLESR events were significantly more frequent in persons with cascade stomach without delayed gastric emptying. PMID:28584403

Optical and near-infrared study of the Ca-rich transient iPTF15eqv in the early phase

NASA Astrophysics Data System (ADS)

Kawahara, Naoki; Yamanaka, Masayuki; Kawabata, Koji; Nakaoka, Tatsuya; Kawabata, Miho; Maeda, Keiichi; Takaki, Katsutoshi; Akitaya, Hiroshi; Itoh, Ryosuke; Moritani, Yuki; Uemura, Makoto; Yoshida, Michitoshi

2018-01-01

Supernovae (SNe) exhibiting strong calcium features in their spectra are called Ca-rich transients. Frequently their early-phase spectra also exhibit helium absorption lines. They are mostly discovered in elliptical galaxies or at a remote location far from the host galaxy center. Well-observed samples are still too limited to clarify the explosion and progenitor properties. We present optical and near-infrared observations of a Ca-rich transient iPTF15eqv in the spiral galaxy NGC 3430. The data are obtained using 1.5-m Kanata telescope since Sep 28, 2015. While the discovery was at a post-maximum-phase, we infer the maximum date to be 30 days before the discovery date, by comparing its light curve and spectroscopic evolution to those of well-observed samples. The spectra exhibit absorption lines of He I and prominent emission lines of Ca II IR and [Ca II] from +31 to 69 d after the maximum date. We find that iPTF15eqv is more luminous than other Ca-rich transients by 1.5 to 2 mag on +31 d, and we estimate that the peak absolute magnitude in the R band is approximately -18 to -16.5 mag. The decline rate of the light curve between 30 and 60 d is similar to those of SNe Ib/c. The line velocity of the helium is similar to those of Ca-rich transients but also to SNe Ib. The ejecta properties inferred from our observations indicate that iPTF15eqv has a larger nickel mass than typical Ca-rich transients. While these properties show similarity to SNe Ib, we show that most of these properties are indeed shared by other Ca-rich transients. The properties of iPTF15eqv may thus still be regarded to be within the diversities among the Ca-rich transients.

Transient ischaemic attacks clinics provide equivalent and more efficient care than early in-hospital assessment.

PubMed

Martínez-Martínez, M M; Martínez-Sánchez, P; Fuentes, B; Cazorla-García, R; Ruiz-Ares, G; Correas-Callero, E; Lara-Lara, M; Díez-Tejedor, E

2013-02-01

Clinics for early management of transient ischaemic attacks (TIAs) have been developed in some stroke centres, resulting in reduced recurrence rates compared to appointment-based outpatient management, thus saving on hospitalization. We analysed the care process, recurrence rates and economic impact of the first year of work in our early-management TIA clinic and compared these with our previous in-hospital study protocols for low- and moderate-risk TIA patients. This was a prospective evaluation of the management of low- to moderate-risk TIA patients, comparing a new TIA clinic model (2010) with a previous hospitalization model (2009). Demographic data, vascular risk factor profiles, diagnostic test performance, secondary prevention measures, final aetiological diagnoses and cerebrovascular recurrences at 7 and 90 days were compared between in-hospital and TIA clinic assessed patients. We also carried out an economic comparison of the costs of each model's process. Two hundred and eleven low- to moderate-risk TIA patients were included, of whom 40.8% were hospitalized. There were no differences between the TIA clinic assessed and in-hospital assessed patients in terms of risk factor diagnosis and secondary prevention measures. The stroke recurrence rate (2.4% vs. 1.2%; P = 0.65) was low and similar for both groups (CI 95%, 0.214-20.436; P = 0.52). Cost per patient was €393.28 for clinic versus €1931.18 for in-hospital management. Outpatient management resulted in a 77.8% reduction in hospitalizations. Transient ischaemic attacks clinics are efficient for the early management of low- to moderate-risk TIA patients compared to in-hospital assessment, with no higher recurrence rates and at almost one-fifth the cost. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

Transient hyperglycemia during liver transplantation does not affect the early graft function.

PubMed

Blasi, Annabel; Beltran, Joan; Martin, Nuria; Martinez-Pallí, Graciela; Lozano, Juan J; Balust, Jaume; Torrents, Abigail; Taura, Pilar

2015-01-01

Background and rationale for the study. Hyperglycemia after graft reperfusion is a consistent finding in liver transplantation (LT) that remains poorly studied. We aim to describe its appearance in LT recipients of different types of grafts and its relation to the graft function. 436 LT recipients of donors after brain death (DBD), donors after cardiac death (DCD), and familial amyloidotic polyneuropathy (FAP) donors were reviewed. Serum glucose was measured at baseline, during the anhepatic phase, after graft reperfusion, and at the end of surgery. Early graft dysfunction (EAD) was assessed by Olthoff criteria. Caspase-3, IFN-γ, IL1β, and IL6 gene expression were measured in liver biopsy. The highest increase in glucose levels after reperfusion was observed in FAP LT recipients and the lowest in DCD LT recipients. Glucose level during the anhepatic phase was the only modifiable predictive variable of hyperglycemia after reperfusion. No relation was found between hyperglycemia after reperfusion and EAD. However, recipients with the highest glucose levels after reperfusion tended to achieve the best glucose control at the end of surgery and those who were unable to control the glucose value after reperfusion showed EAD more frequently. The highest levels of caspase-3 were found in recipients with the lowest glucose values after reperfusion. In conclusion, glucose levels increased after graft reperfusion to a different extent according to the donor type. Contrary to general belief, transient hyperglycemia after reperfusion does not appear to impact negatively on the liver graft function and could even be suggested as a marker of graft quality.

New SPIRITS discoveries of Infrared Transients and Variables

NASA Astrophysics Data System (ADS)

Jencson, J. E.; Kasliwal, M. M.; Adams, S.; Cook, D.; Tinyanont, S.; Kwan, S.; Prince, T.; Lau, R. M.; Perley, D.; Masci, F.; Helou, G.; Armus, L.; Surace, J.; Dyk, S. D. Van; Cody, A.; Boyer, M. L.; Bond, H. E.; Monson, A.; Bally, J.; Khan, R.; Levesque, E.; Fox, O.; Williams, R.; Whitelock, P. A.; Mohamed, S.; Gehrz, R. D.; Amodeo, S.; Shenoy, D.; Carlon, R.; Cass, A.; Corgan, D.; Dykhoff, D.; Faella, J.; Gburek, T.; Smith, N.; Cantiello, M.; Langer, N.; Ofek, E.; Johansson, J.; Parthasarathy, M.; Hsiao, E.; Phillips, M.; Morrell, N.; Gonzalez, C.; Contreras, C.

2017-10-01

We report the discoveries of mid-infrared transients/strong variables found in the course of the Spitzer InfraRed Intensive Transients Survey (SPIRITS) using Spitzer Early Release Data (ATel #6644, #7929, #8688, #8940, #9434, #10171, #10172, #10488).

Increases of Catalase and Glutathione Peroxidase Expressions by Lacosamide Pretreatment Contributes to Neuroprotection Against Experimentally Induced Transient Cerebral Ischemia.

PubMed

Choi, Hyun Young; Park, Joon Ha; Chen, Bai Hui; Shin, Bich Na; Lee, Yun Lyul; Kim, In Hye; Cho, Jeong-Hwi; Lee, Tae-Kyeong; Lee, Jae-Chul; Won, Moo-Ho; Ahn, Ji Hyeon; Tae, Hyun-Jin; Yan, Bing Chun; Hwang, In Koo; Cho, Jun Hwi; Kim, Young-Myeong; Kim, Sung Koo

2016-09-01

Lacosamide is a new antiepileptic drug which is widely used to treat partial-onset seizures. In this study, we examined the neuroprotective effect of lacosamide against transient ischemic damage and expressions of antioxidant enzymes such as Zn-superoxide dismutase (SOD1), Mn-superoxide dismutase (SOD2), catalase (CAT) and glutathione peroxidase (GPX) in the hippocampal cornu ammonis 1 (CA1) region following 5 min of transient global cerebral ischemia in gerbils. We found that pre-treatment with 25 mg/kg lacosamide protected CA1 pyramidal neurons from transient global cerebral ischemic insult using hematoxylin-eosin staining and neuronal nuclear antigen immunohistochemistry. Transient ischemia dramatically changed expressions of SOD1, SOD2 and GPX, not CAT, in the CA1 pyramidal neurons. Lacosamide pre-treatment increased expressions of CAT and GPX, not SOD1 and 2, in the CA1 pyramidal neurons compared with controls, and their expressions induced by lacosamide pre-treatment were maintained after transient cerebral ischemia. In brief, pre-treatment with lacosamide protected hippocampal CA1 pyramidal neurons from ischemic damage induced by transient global cerebral ischemia, and the lacosamide-mediated neuroprotection may be closely related to increases of CAT and GPX expressions by lacosamide pre-treatment.

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.

Effect of antemortem and postmortem factors on ( sup 3 H)MK-801 binding in the human brain: Transient elevation during early childhood

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

Kornhuber, J.; Mack-Burkhardt, F.; Konradi, C.

1989-01-01

The effect of a number of antemortem and postmortem factors on ({sup 3}H)MK-801 binding was investigated under equilibrium conditions in the frontal cortex of human brains of 38 controls. Binding values transiently increased during the early postnatal period reaching a maximum at the age of about 2 years. After age 10 years ({sup 3}H)MK-801 binding sites disappeared at 5.7% per decade. The storage time of brain tissue had a reducing effect on these binding sites. There was no effect of gender, brain weight or postmortem time interval and the binding sites were bilaterally symmetrically distributed in the frontal cortex.

Effect of leaf incubation temperature profiles on Agrobacterium tumefaciens-mediated transient expression.

PubMed

Jung, Sang-Kyu; McDonald, Karen A; Dandekar, Abhaya M

2015-01-01

Agrobacterium tumefaciens-mediated transient expression is known to be highly dependent on incubation temperature. Compared with early studies that were conducted at constant temperature, we examined the effect of variable leaf incubation temperature on transient expression. As a model system, synthetic endoglucanase (E1) and endoxylanase (Xyn10A) genes were transiently expressed in detached whole sunflower leaves via vacuum infiltration for biofuel applications. We found that the kinetics of transient expression strongly depended on timing of the temperature change as well as leaf incubation temperature. Surprisingly, we found that high incubation temperature (27-30 °C) which is suboptimal for T-DNA transfer, significantly enhanced transient expression if the high temperature was applied during the late phase (Day 3-6) of leaf incubation whereas incubation temperature in a range of 20-25 °C for an early phase (Day 0-2) resulted in higher production. On the basis of these results, we propose that transient expression is governed by both T-DNA transfer and protein synthesis in plant cells that have different temperature dependent kinetics. Because the phases were separated in time and had different optimal temperatures, we were then able to develop a novel two phase optimization strategy for leaf incubation temperature. Applying the time-varying temperature profile, we were able to increase the protein accumulation by fivefold compared with the control at a constant temperature of 20 °C. From our knowledge, this is the first report illustrating the effect of variable temperature profiling for improved transient expression. © 2015 American Institute of Chemical Engineers.

Transient elastography with the XL probe rapidly identifies patients with nonhepatic ascites.

PubMed

Kohlhaas, Anna; Durango, Esteban; Millonig, Gunda; Bastard, Cecile; Sandrin, Laurent; Golriz, Mohammad; Mehrabi, Arianeb; Büchler, Markus W; Seitz, Helmut Karl; Mueller, Sebastian

2012-01-01

In contrast with other elastographic techniques, ascites is considered an exclusion criterion for assessment of fibrosis stage by transient elastography. However, a normal liver stiffness could rule out hepatic causes of ascites at an early stage. The aim of the present study was to determine whether liver stiffness can be generally determined by transient elastography through an ascites layer, to determine whether the ascites-mediated increase in intra-abdominal pressure affects liver stiffness, and to provide initial data from a pilot cohort of patients with various causes of ascites. Using the XL probe in an artificial ascites model, we demonstrated (copolymer phantoms surrounded by water) that a transient elastography-generated shear wave allows accurate determination of phantom stiffness up to a water lamella of 20 mm. We next showed in an animal ascites model that increased intra-abdominal pressure does not affect liver stiffness. Liver stiffness was then determined in 24 consecutive patients with ascites due to hepatic (n = 18) or nonhepatic (n = 6) causes. The cause of ascites was eventually clarified using routine clinical, imaging, laboratory, and other tools. Valid (75%) or acceptable (25%) liver stiffness data could be obtained in 23 patients (95.8%) with ascites up to an ascites lamella of 39 mm. The six patients (25%) with nonhepatic causes of ascites (eg, pancreatitis, peritoneal carcinomatosis) had a significantly lower liver stiffness (<8 kPa) as compared with the remaining patients with hepatic ascites (>30 kPa). Mean liver stiffness was 5.4 kPa ± 1.3 versus 66.2 ± 13.3 kPa. In conclusion, the presence of ascites and increased intra-abdominal pressure does not alter underlying liver stiffness as determined by transient elastography. We suggest that, using the XL probe, transient elastography can be used first-line to identify patients with nonhepatic ascites at an early stage.

Short-term increases in transient receptor potential vanilloid-1 mediate stress-induced enhancement of neuronal excitation.

PubMed

Weitlauf, Carl; Ward, Nicholas J; Lambert, Wendi S; Sidorova, Tatiana N; Ho, Karen W; Sappington, Rebecca M; Calkins, David J

2014-11-12

Progression of neurodegeneration in disease and injury is influenced by the response of individual neurons to stressful stimuli and whether this response includes mechanisms to counter declining function. Transient receptor potential (TRP) cation channels transduce a variety of disease-relevant stimuli and can mediate diverse stress-dependent changes in physiology, both presynaptic and postsynaptic. Recently, we demonstrated that knock-out or pharmacological inhibition of the TRP vanilloid-1 (TRPV1) capsaicin-sensitive subunit accelerates degeneration of retinal ganglion cell neurons and their axons with elevated ocular pressure, the critical stressor in the most common optic neuropathy, glaucoma. Here we probed the mechanism of the influence of TRPV1 on ganglion cell survival in mouse models of glaucoma. We found that induced elevations of ocular pressure increased TRPV1 in ganglion cells and its colocalization at excitatory synapses to their dendrites, whereas chronic elevation progressively increased ganglion cell Trpv1 mRNA. Enhanced TRPV1 expression in ganglion cells was transient and supported a reversal of the effect of TRPV1 on ganglion cells from hyperpolarizing to depolarizing, which was also transient. Short-term enhancement of TRPV1-mediated activity led to a delayed increase in axonal spontaneous excitation that was absent in ganglion cells from Trpv1(-/-) retina. In isolated ganglion cells, pharmacologically activated TRPV1 mobilized to discrete nodes along ganglion cell dendrites that corresponded to sites of elevated Ca(2+). These results suggest that TRPV1 may promote retinal ganglion cell survival through transient enhancement of local excitation and axonal activity in response to ocular stress. Copyright © 2014 the authors 0270-6474/14/3415369-13$15.00/0.

Factors Affecting Canagliflozin-Induced Transient Urine Volume Increase in Patients with Type 2 Diabetes Mellitus.

PubMed

Tanaka, Hiroyuki; Takano, Kazuhiko; Iijima, Hiroaki; Kubo, Hajime; Maruyama, Nobuko; Hashimoto, Toshio; Arakawa, Kenji; Togo, Masanori; Inagaki, Nobuya; Kaku, Kohei

2017-02-01

Sodium glucose co-transporter 2 (SGLT2) inhibitors exhibit diuretic activity, which is a possible mechanism underlying the cardiovascular benefit of these inhibitors. However, the osmotic diuresis-induced increase in urine volume, and the risk of dehydration have been of concern with SGLT2 inhibitor treatment. This study aimed to investigate the mechanism underlying SGLT2 inhibitor canagliflozin-induced diuresis in Japanese type 2 diabetes mellitus (T2DM) patients. Thirteen T2DM patients received a daily oral dose of 100 mg canagliflozin before breakfast for 6 days. Blood and urine samples were collected at predetermined time points. The primary endpoint was evaluation of correlations between changes from baseline in urine volume and factors that are known to affect urine volume and between actual urine volume and these factors. Canagliflozin transiently increased urine volume and urinary sodium excretion on Day 1 with a return to baseline levels thereafter. Canagliflozin administration increased urinary glucose excretion, which was sustained during repeated-dose administration. Plasma atrial natriuretic peptide (ANP) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels decreased, while plasma renin activity increased. On Day 1 of treatment, changes in sodium and potassium excretion were closely correlated with changes in urine output. A post hoc multiple regression analysis showed changes in sodium excretion and water intake as factors that affected urine volume change at Day 1. Furthermore, relative to that at baseline, canagliflozin decreased blood glucose throughout the day and increased plasma total GLP-1 after breakfast. Canagliflozin induced transient sodium excretion and did not induce water intake at Day 1; hence, natriuresis rather than glucose-induced osmotic diuresis may be a major factor involved in the canagliflozin-induced transient increase in urine output. In addition, canagliflozin decreased plasma ANP and NT-proBNP levels and

LOCALIZATION OF SHORT DURATION GRAVITATIONAL-WAVE TRANSIENTS WITH THE EARLY ADVANCED LIGO AND VIRGO DETECTORS

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

Essick, Reed; Vitale, Salvatore; Katsavounidis, Erik

2015-02-20

The Laser Interferometer Gravitational wave Observatory (LIGO) and Virgo advanced ground-based gravitational-wave detectors will begin collecting science data in 2015. With first detections expected to follow, it is important to quantify how well generic gravitational-wave transients can be localized on the sky. This is crucial for correctly identifying electromagnetic counterparts as well as understanding gravitational-wave physics and source populations. We present a study of sky localization capabilities for two search and parameter estimation algorithms: coherent WaveBurst, a constrained likelihood algorithm operating in close to real-time, and LALInferenceBurst, a Markov chain Monte Carlo parameter estimation algorithm developed to recover generic transientmore » signals with latency of a few hours. Furthermore, we focus on the first few years of the advanced detector era, when we expect to only have two (2015) and later three (2016) operational detectors, all below design sensitivity. These detector configurations can produce significantly different sky localizations, which we quantify in detail. We observe a clear improvement in localization of the average detected signal when progressing from two-detector to three-detector networks, as expected. Although localization depends on the waveform morphology, approximately 50% of detected signals would be imaged after observing 100-200 deg{sup 2} in 2015 and 60-110 deg{sup 2} in 2016, although knowledge of the waveform can reduce this to as little as 22 deg{sup 2}. This is the first comprehensive study on sky localization capabilities for generic transients of the early network of advanced LIGO and Virgo detectors, including the early LIGO-only two-detector configuration.« less

Risk factors for early death in transient myeloproliferative disorder without phenotypic features of Down syndrome: a case report and literature review.

PubMed

Kawase, Koya; Azuma, Eiichi; Ohshita, Hironori; Tanaka, Tatsushi; Hanada, Yu; Sasaki, Tomoaki; Sugimoto, Mari; Togawa, Takao; Kouwaki, Masanori; Ito, Tsuyoshi; Hirayama, Masahiro; Koyama, Norihisa

2012-08-01

Not only in newborns with Down syndrome, but newborns without phenotypic features of Down syndrome also develop transient myeloproliferative disorder (TMD). In these cases, trisomy 21 and related chromosomal abnormalities are either constitutionally mosaic or limited to blood cells. Risk factors for early death of these patients are unknown so far. We here report a fatal case of TMD without phenotypic features of Down syndrome and review literature to identify risk factors associated with early death. Not only are gestational age and white blood cell count risk factors for early death in TMD with Down syndrome, but they also appear to be risk factors in TMD without Down syndrome.

Transient increase of interleukin-1β after prolonged febrile seizures promotes adult epileptogenesis through long-lasting upregulating endocannabinoid signaling

PubMed Central

Feng, Bo; Tang, Yangshun; Chen, Bin; Xu, Cenglin; Wang, Yi; Dai, Yunjian; Wu, Dengchang; Zhu, Junmin; Wang, Shuang; Zhou, Yudong; Shi, Liyun; Hu, Weiwei; Zhang, Xia; Chen, Zhong

2016-01-01

It remains unclear how infantile febrile seizures (FS) enhance adult seizure susceptibility. Here we showed that the transient increase of interleukin-1β (IL-1β) after prolonged FS promoted adult seizure susceptibility, which was blocked by interleukin-1 receptor antagonist (IL-1Ra) within a critical time window. Postnatal administered IL-1β alone mimicked the effect of FS on adult seizure susceptibility. IL-1R1 knockout mice were not susceptible to adult seizure after prolonged FS or IL-1β treatment. Prolonged FS or early-life IL-1β treatment increased the expression of cannabinoid type 1 receptor (CB1R) for over 50 days, which was blocked by IL-1Ra or was absent in IL-1R1 knockout mice. CB1R antagonist, knockdown and endocannabinoid synthesis inhibitor abolished FS or IL-1β-enhanced seizure susceptibility. Thus, this work identifies a pathogenic role of postnatal IL-1β/IL-1R1 pathway and subsequent prolonged prominent increase of endocannabinoid signaling in adult seizure susceptibility following prolonged FS, and highlights IL-1R1 as a potential therapeutic target for preventing the development of epilepsy after infantile FS. PMID:26902320

Association of transient hyperthyroidism and severity of hyperemesis gravidarum.

PubMed

Malek, Nor Zila Hassan; Kalok, Aida; Hanafiah, Zainal Abidin; Shah, Shamsul Azhar; Ismail, Nor Azlin Mohamed

2017-03-23

Background Transient non-immune hyperthyroidism in early pregnancy is hyperthyroidism diagnosed for the first time in early pregnancy, without evidence of thyroid autoimmunity or clinical findings of Grave's disease and resolved spontaneously as the pregnancy progressed. Hyperemesis gravidarum (HG) is the commonest cause with 66%-73% of women with severe HG were found to have elevated thyroid function. Materials and methods We conducted a cross sectional study to determine the prevalence of transient hyperthyroidism in patients with hyperemesis gravidarum and its relation to the severity of nausea and vomiting. Severity of nausea and vomiting in pregnancy was assessed using the modified pregnancy-unique quantification of emesis (PUQE) scoring system. Each patient had urine and blood investigations which also included a full blood count and thyroid and renal function tests. Patients with abnormal thyroid function were retested at 20 weeks of gestation. The patients' demographic data, electrolyte levels, thyroid function and their respective PUQE score were analyzed. Results The prevalence of transient hyperthyroidism in women with hyperemesis gravidarum was 4.8%. Although there was a significant association between the severity of the PUQE score and hypokalemia (p = 0.001), there was no significant association with transient hyperthyroidism in early pregnancy (p = 0.072). Free T4 and TSH values of all women with transient hyperthyroidism were normalized by 20 weeks of gestation. Conclusion Transient hyperthyroidism in pregnancy is not significantly associated with the severity of the PUQE score. Women with transient hyperthyroidism in pregnancy are normally clinically euthyroid, hence a routine thyroid function test is unnecessary unless they exhibit clinical signs or symptoms of hyperthyroidism.

On the use of variability time-scales as an early classifier of radio transients and variables

NASA Astrophysics Data System (ADS)

Pietka, M.; Staley, T. D.; Pretorius, M. L.; Fender, R. P.

2017-11-01

We have shown previously that a broad correlation between the peak radio luminosity and the variability time-scales, approximately L ∝ τ5, exists for variable synchrotron emitting sources and that different classes of astrophysical sources occupy different regions of luminosity and time-scale space. Based on those results, we investigate whether the most basic information available for a newly discovered radio variable or transient - their rise and/or decline rate - can be used to set initial constraints on the class of events from which they originate. We have analysed a sample of ≈800 synchrotron flares, selected from light curves of ≈90 sources observed at 5-8 GHz, representing a wide range of astrophysical phenomena, from flare stars to supermassive black holes. Selection of outbursts from the noisy radio light curves has been done automatically in order to ensure reproducibility of results. The distribution of rise/decline rates for the selected flares is modelled as a Gaussian probability distribution for each class of object, and further convolved with estimated areal density of that class in order to correct for the strong bias in our sample. We show in this way that comparing the measured variability time-scale of a radio transient/variable of unknown origin can provide an early, albeit approximate, classification of the object, and could form part of a suite of measurements used to provide early categorization of such events. Finally, we also discuss the effect scintillating sources will have on our ability to classify events based on their variability time-scales.

Transient extracellular application of gold nanostars increases hippocampal neuronal activity.

PubMed

Salinas, Kirstie; Kereselidze, Zurab; DeLuna, Frank; Peralta, Xomalin G; Santamaria, Fidel

2014-08-20

With the increased use of nanoparticles in biomedical applications there is a growing need to understand the effects that nanoparticles may have on cell function. Identifying these effects and understanding the mechanism through which nanoparticles interfere with the normal functioning of a cell is necessary for any therapeutic or diagnostic application. The aim of this study is to evaluate if gold nanoparticles can affect the normal function of neurons, namely their activity and coding properties. We synthesized star shaped gold nanoparticles of 180 nm average size. We applied the nanoparticles to acute mouse hippocampal slices while recording the action potentials from single neurons in the CA3 region. Our results show that CA3 hippocampal neurons increase their firing rate by 17% after the application of gold nanostars. The increase in excitability lasted for as much as 50 minutes after a transient 5 min application of the nanoparticles. Further analyses of the action potential shape and computational modeling suggest that nanoparticles block potassium channels responsible for the repolarization of the action potentials, thus allowing the cell to increase its firing rate. Our results show that gold nanoparticles can affect the coding properties of neurons by modifying their excitability.

Transient tracer applications in the Southern Ocean

NASA Astrophysics Data System (ADS)

Stöven, T.; Tanhua, T.; Hoppema, M.

2014-10-01

Transient tracers can be used to constrain the Inverse-Gaussian transit time distribution (IG-TTD) and thus provide information about ocean ventilation. Individual transient tracers have different time and application ranges which are defined by their atmospheric history (chronological transient tracers) or their decay rate (radioactive transient tracers). The classification ranges from tracers for highly ventilated water masses, e.g. sulfur hexafluoride (SF6), the decay of Tritium (δ3H) and to some extent also dichlorodifluoromethane (CFC-12) to tracers for less ventilated deep ocean basins, e.g. CFC-12, Argon-39 (39Ar) and radiocarbon (14C). The IG-TTD can be empirically constrained by using transient tracer couples with sufficiently different input functions. Each tracer couple has specific characteristics which influence the application limit of the IG-TTD. Here we provide an overview of commonly used transient tracer couples and their validity areas within the IG-TTD by using the concept of tracer age differences (TAD). New measured CFC-12 and SF6 data from a section along 10° E in the Southern Ocean in 2012 are presented. These are combined with a similar data set of 1998 along 6° E in the Southern Ocean as well as with 39Ar data from the early 1980s in the western Atlantic Ocean and the Weddell Sea for investigating the application limit of the IG-TTD and to analyze changes in ventilation in the Southern Ocean. We found that the IG-TTD can be constrained south to 46° S which corresponds to the Subantarctic Front (SAF) denoting the application limit. The constrained IG-TTD north of the SAF shows a slight increase in mean ages between 1998 and 2012 in the upper 1200 m between 42-46° S. The absence of SF6 inhibits ventilation analyses below this depth. The time lag analysis between the 1998 and 2012 data shows an increase in ventilation down to 1000 m and a steady ventilation between 2000 m-bottom south of the SAF between 51-55° S.

Transient elastography with the XL probe rapidly identifies patients with nonhepatic ascites

PubMed Central

Kohlhaas, Anna; Durango, Esteban; Millonig, Gunda; Bastard, Cecile; Sandrin, Laurent; Golriz, Mohammad; Mehrabi, Arianeb; Büchler, Markus W; Seitz, Helmut Karl; Mueller, Sebastian

2012-01-01

Background In contrast with other elastographic techniques, ascites is considered an exclusion criterion for assessment of fibrosis stage by transient elastography. However, a normal liver stiffness could rule out hepatic causes of ascites at an early stage. The aim of the present study was to determine whether liver stiffness can be generally determined by transient elastography through an ascites layer, to determine whether the ascites-mediated increase in intra-abdominal pressure affects liver stiffness, and to provide initial data from a pilot cohort of patients with various causes of ascites. Methods and results Using the XL probe in an artificial ascites model, we demonstrated (copolymer phantoms surrounded by water) that a transient elastography-generated shear wave allows accurate determination of phantom stiffness up to a water lamella of 20 mm. We next showed in an animal ascites model that increased intra-abdominal pressure does not affect liver stiffness. Liver stiffness was then determined in 24 consecutive patients with ascites due to hepatic (n = 18) or nonhepatic (n = 6) causes. The cause of ascites was eventually clarified using routine clinical, imaging, laboratory, and other tools. Valid (75%) or acceptable (25%) liver stiffness data could be obtained in 23 patients (95.8%) with ascites up to an ascites lamella of 39 mm. The six patients (25%) with nonhepatic causes of ascites (eg, pancreatitis, peritoneal carcinomatosis) had a significantly lower liver stiffness (<8 kPa) as compared with the remaining patients with hepatic ascites (>30 kPa). Mean liver stiffness was 5.4 kPa ± 1.3 versus 66.2 ± 13.3 kPa. Conclusion In conclusion, the presence of ascites and increased intra-abdominal pressure does not alter underlying liver stiffness as determined by transient elastography. We suggest that, using the XL probe, transient elastography can be used first-line to identify patients with nonhepatic ascites at an early stage. PMID:24367229

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).

Transient increase in the levels of gamma-tubulin complex in reorientation of cortical microtubules by gravity in azuki bean epicotyls

NASA Astrophysics Data System (ADS)

Soga, Kouichi; Kotake, Toshihisa; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Hoson, Takayuki

Azuki bean (Vigna angularis Ohwi et Ohashi) seedlings were exposed to centrifugal hypergravity, and the changes in the orientation of cortical microtubules and the expression of genes cording γ-tubulin complex (VaTUBG and VaSpc98p) were examined. By 300 g treatment, the percentage of cells with transverse microtubules was decreased, while that with longitudinal microtubules was increased in epicotyls. Hypergravity increased the expression of VaTUBG and VaSpc98p transiently. Also, the expression of both genes was increased transiently by removal of hypergravity stimulus. Lanthanum and gadolinium ions, potential blockers of mechanosensitive calcium ion-permeable channels (mechanoreceptors), nullified reorientation of microtubules as well as up-regulation of expression of VaTUBG and VaSpc98p by hypergravity. These results suggest that mechanoreceptors on the plasma membrane may perceive the gravity signal, which leads to reorientation of cortical microtubules by transiently stimulating the formation of γ-tubulin complex.

Scaling of Transient Storage Parameter Estimates with Increasing Reach Length in a Mountain Headwater Stream

NASA Astrophysics Data System (ADS)

Briggs, M.; Gooseff, M. N.; McGlynn, B.

2006-12-01

. Numerous studies have used the methods of stream tracer experiments and subsequent solute transport modeling to determine transient storage characteristics of streams. Experimental reach length is often determined by site logistics, morphology, specific study goals, etc. Harvey et al. [1996] provided guidance for optimal study reach lengths, based on the Dahmkoler number, as a balance between timescales of advective transport and transient storage. In this study, we investigate the scaling of parameters in a solute transport model (OTIS) with increasing spatial scale of investigation. We conducted 2 6-hour constant rate injections of dissolved NaCl in Spring Park Creek, a headwater stream in the Tenderfoot Creek Experimental Forest, Montana. Below the first injection we sampled 4 reaches ~200m in length, we then moved upstream 640m for the second injection and sampled 3 more ~200 m reaches. Solute transport simulations were conducted for each of these sub-reaches and for combinations of these sub-reaches, from which we assessed estimates of solute velocity, dispersion, transient storage exchange, storage zone size, and Fmed (proportion of median transport time due to storage). Dahmkoler values calculated for each simulation (sub-reaches as well as longer combined reach) were within an order of magnitude of 1, suggesting that our study reach lengths were appropriate. Length-weighted average solute transport and transient storage parameters for the sub-reaches were found to be comparable to their counterparts in the longer reach simulation. In particular the average dispersion found for the sub-reaches (0.43 m2/s) compared very favorably with the value for dispersion calculated for the larger reach (0.40 m2/s). In contrast the weighted average of storage zone size for the sub-reaches was much greater (1.17 m2) than those calculated for the injection reach as a whole (0.09 m2) by a factor of ~13. Weighted average values for transient storage exchange and size for

[Transient enlargement of craniopharyngioma cysts after stereotactic radiotherapy and radiosurgery].

PubMed

Mazerkina, N A; Savateev, A N; Gorelyshev, S K; Konovalov, A N; Trunin, Yu Yu; Golanov, A V; Medvedeva, O A; Kalinin, P L; Kutin, M A; Astafieva, L I; Krasnova, T S; Ozerova, V I; Serova, N K; Butenko, E I; Strunina, Yu V

Stereotactic radiotherapy/radiosurgery (RT/ES) is an effective technique for treating craniopharyngiomas (CPs). However, enlargement of the cystic part of the tumor occurs in some cases after irradiation. The enlargement may be transient and not require treatment or be a true relapse requiring treatment. In this study, we performed a retrospective analysis of 79 pediatric patients who underwent stereotactic RT or RS after resection of craniopharyngioma. Five-year relapse-free survival after complex treatment of CP was 86%. In the early period after irradiation, 3.5 months (2.7-9.4) on average, enlargement of the cystic component of the tumor was detected in 10 (12.7%) patients; in 9 (11.4%) of them, the enlargement was transient and did not require treatment; in one case, the patient underwent surgery due to reduced visual acuity. In 8 (10.1%) patients, an increase in the residual tumor (a solid component of the tumor in 2 cases and a cystic component of the tumor in 6 cases) occurred in the long-term period after irradiation - after 26.3 months (16.6-48.9) and did not decrease during follow-up in none of the cases, i.e. continued growth of the tumor was diagnosed. A statistical analysis revealed that differences in the terms of transient enlargement and true continued growth were statistically significant (p<0.01). Enlargement of a craniopharyngioma cyst in the early period (up to 1 year) after RT/RS is usually transient and does not require surgical treatment (except cases where worsening of neurological symptoms occurs, or occlusive hydrocephalus develops).

Red-breasted nuthatches detect early increases in spruce budworm populations

Treesearch

Hewlette S. Crawford; Daniel T. Jennings; Timothy L. Stone

1990-01-01

Early suppression .of increasing spruce budworm populations is essential to prevent epidemics; however, early changes in budworm numbers are difficult to detect. An effective and inexpensive method to detect early increases is needed. Red-breasted nuthatches eat more spruce budworm larvae and pupae as the insect increases in number. We estimated the number of large...

Recent SPIRITS discoveries of Infrared Transients and Variables with Spitzer/IRAC

NASA Astrophysics Data System (ADS)

Jencson, J. E.; Kasliwal, M. M.; Adams, S.; Cook, D.; Tinyanont, S.; Kwan, S.; Prince, T.; Lau, R. M.; Perley, D.; Masci, F.; Helou, G.; Armus, L.; Surace, J.; Dyk, S. D. Van; Cody, A.; Boyer, M. L.; Bond, H. E.; Monson, A.; Bally, J.; Khan, R.; Levesque, E.; Fox, O.; Williams, R.; Whitelock, P. A.; Mohamed, S.; Gehrz, R. D.; Amodeo, S.; Shenoy, D.; Carlon, R.; Cass, A.; Corgan, D.; Dykhoff, D.; Faella, J.; Gburek, T.; Smith, N.; Cantiello, M.; Langer, N.; Ofek, E.; Johansson, J.; Parthasarathy, M.; Hsiao, E.; Phillips, M.; Morrell, N.; Gonzalez, C.; Contreras, C.

2018-04-01

We report the discoveries of mid-infrared transients/strong variables found in the course of the Spitzer InfraRed Intensive Transients Survey (SPIRITS) using Spitzer Early Release Data (ATel #6644, #7929, #8688, #8940, #9434, #10171, #10172, #10488, #10903).

Early Initiation of Anticoagulation with Direct Oral Anticoagulants in Patients after Transient Ischemic Attack or Ischemic Stroke.

PubMed

Macha, Kosmas; Volbers, Bastian; Bobinger, Tobias; Kurka, Natalia; Breuer, Lorenz; Huttner, Hagen B; Schwab, Stefan; Köhrmann, Martin

2016-09-01

Direct oral anticoagulants (DOACs) are increasingly used for secondary prevention of cardioembolic stroke. While DOACs are associated with a long-term reduced risk of intracranial hemorrhage compared to vitamin K antagonists, pivotal trials avoided the very early period after stroke and few data exist on early initiation of DOAC therapy post stroke. We retrospectively analyzed data from our prospective database of all consecutive transient ischemic attack (TIA) or ischemic stroke patients with atrial fibrillation treated with DOACs during hospital stay. As per our institutional treatment algorithm for patients with cardioembolic ischemia DOACs are started immediately in TIA and minor stroke (group 1), within days 3-5 in patients with infarcts affecting one third or less of the middle cerebral artery, the anterior cerebral artery, or the posterior cerebral artery territories (group 2) as well as in infratentorial stroke (group 3) and after 1-2 weeks in patients with large infarcts (>⅓MCA territory, group 4). We investigated baseline characteristics, time to initiation of DOAC therapy after symptom onset, and hemorrhagic complications. In 243 included patients, administration of DOAC was initiated 40.5 hours (interquartile range [IQR] 23.0-65.5) after stroke onset in group 1 (n = 41) and after 76.7 hours (IQR 48.0-134.0), 108.4 hours (IQR 67.3-176.4), and 161.8 hours (IQR 153.9-593.8) in groups 2-4 (n = 170, 28, and 4), respectively. Two cases of asymptomatic intracranial hemorrhage (.8%) and 1 case of symptomatic intracranial hemorrhage (.4%) were observed, both in group 2. No severe safety issues were observed in early initiation of DOACs for secondary prevention after acute stroke in our in-patient cohort. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Transient rapamycin treatment can increase lifespan and healthspan in middle-aged mice

PubMed Central

Bitto, Alessandro; Ito, Takashi K; Pineda, Victor V; LeTexier, Nicolas J; Huang, Heather Z; Sutlief, Elissa; Tung, Herman; Vizzini, Nicholas; Chen, Belle; Smith, Kaleb; Meza, Daniel; Yajima, Masanao; Beyer, Richard P; Kerr, Kathleen F; Davis, Daniel J; Gillespie, Catherine H; Snyder, Jessica M; Treuting, Piper M; Kaeberlein, Matt

2016-01-01

The FDA approved drug rapamycin increases lifespan in rodents and delays age-related dysfunction in rodents and humans. Nevertheless, important questions remain regarding the optimal dose, duration, and mechanisms of action in the context of healthy aging. Here we show that 3 months of rapamycin treatment is sufficient to increase life expectancy by up to 60% and improve measures of healthspan in middle-aged mice. This transient treatment is also associated with a remodeling of the microbiome, including dramatically increased prevalence of segmented filamentous bacteria in the small intestine. We also define a dose in female mice that does not extend lifespan, but is associated with a striking shift in cancer prevalence toward aggressive hematopoietic cancers and away from non-hematopoietic malignancies. These data suggest that a short-term rapamycin treatment late in life has persistent effects that can robustly delay aging, influence cancer prevalence, and modulate the microbiome. DOI: http://dx.doi.org/10.7554/eLife.16351.001 PMID:27549339

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.

Associations of different phenotypes of wheezing illness in early childhood with environmental variables implicated in the aetiology of asthma.

PubMed

Granell, Raquel; Sterne, Jonathan A C; Henderson, John

2012-01-01

Asthma is a complex heterogeneous disease that has increased in prevalence in many industrialised countries. However, the causes of asthma inception remain elusive. Consideration of sub-phenotypes of wheezing may reveal important clues to aetiological risk factors. Longitudinal phenotypes capturing population heterogeneity in wheezing reports from birth to 7 years were derived using latent class analysis in the Avon Longitudinal Study of Parents and Children (ALSPAC). Probability of class membership was used to examine the association between five wheezing phenotypes (transient early, prolonged early, intermediate-onset, late-onset, persistent) and early life risk factors for asthma. Phenotypes had similar patterns and strengths of associations with early environmental factors. Comparing transient early with prolonged early wheezing showed a similar pattern of association with most exposure variables considered in terms of the direction of the effect estimates but with prolonged early wheezing tending to have stronger associations than transient early wheezing except for parity and day care attendance. Associations with early life risk factors suggested that prolonged early wheeze might be a severe form of transient early wheezing. Although differences were found in the associations of early life risk factors with individual phenotypes, these did not point to novel aetiological pathways. Persistent wheezing phenotype has features suggesting overlap of early and late-onset phenotypes.

Transient and permanent hypocalcemia after total thyroidectomy: Early predictive factors and long-term follow-up results.

PubMed

Seo, Sung Tae; Chang, Jae Won; Jin, Jun; Lim, Young Chang; Rha, Ki-Sang; Koo, Bon Seok

2015-12-01

Post-thyroidectomy hypocalcemia is among the most common complications of total thyroidectomy. The purpose of this study was to evaluate early predictive factors and long-term changes in intact parathyroid hormone (iPTH) levels in patients with transient and permanent hypocalcemia after total thyroidectomy. A total of 349 consecutive patients who underwent total thyroidectomy with or without neck dissection between 2009 and 2011 were reviewed. PTH, total calcium (Ca), and ionized Ca (iCa) levels were evaluated at 1 hour, and 1, 3, 5, and 7 days, and 1, 3, 6, and 12 months postoperatively. Biochemical profiles at 1 hour after total thyroidectomy in patients with transient and permanent hypocalcemia were compared. Patients with postoperative hypocalcemia were followed for 12 months. Lesser preoperative serum levels of Ca and more extensive surgery were significantly associated with postoperative hypocalcemia (P < .05). The absolute level and relative decline (%) in iPTH at 1 hour were the most reliable predictors of postoperative hypocalcemia according to the receiver operating characteristics curve, with a threshold of 10.42 pg/mL and 70%. Sensitivity and specificity of the predictors were 83.4% (95% CI, 76.4-89.1), 100% (95% CI, 84.6-100.0), 84.1 (95% CI, 77.2-89.7), and 95.5% (95% CI, 77.2-99.9), respectively. Parathyroid function recovered in the first month after total thyroidectomy in 78 of 99 patients (79%) with transient hypocalcemia. However, 46 of 61 patients (74%) with a subnormal iPTH level at 3 months after surgery had permanent hypocalcemia. Mean postoperative PTH level and the mean relative decline in PTH measured 1 hour postoperatively were the most reliable predictors of postoperative or permanent hypocalcemia. Copyright © 2015 Elsevier Inc. All rights reserved.

Early-Time Observations of the GRB 050319 Optical Transient

NASA Astrophysics Data System (ADS)

Quimby, R. M.; Rykoff, E. S.; Yost, S. A.; Aharonian, F.; Akerlof, C. W.; Alatalo, K.; Ashley, M. C. B.; Göǧüş, E.; Güver, T.; Horns, D.; Kehoe, R. L.; Kιzιloǧlu, Ü.; Mckay, T. A.; Özel, M.; Phillips, A.; Schaefer, B. E.; Smith, D. A.; Swan, H. F.; Vestrand, W. T.; Wheeler, J. C.; Wren, J.

2006-03-01

We present the unfiltered ROTSE-III light curve of the optical transient associated with GRB 050319 beginning 4 s after the cessation of γ-ray activity. We fit a power-law function to the data using the revised trigger time given by Chincarini and coworkers, and a smoothly broken power-law to the data using the original trigger disseminated through the GCN notices. Including the RAPTOR data from Woźniak and coworkers, the best-fit power-law indices are α=-0.854+/-0.014 for the single power-law and α1=-0.364+0.020-0.019, α2=-0.881+0.030-0.031, with a break at tb=418+31-30 s for the smoothly broken fit. We discuss the fit results, with emphasis placed on the importance of knowing the true start time of the optical transient for this multipeaked burst. As Swift continues to provide prompt GRB locations, it becomes more important to answer the question, ``when does the afterglow begin?'' in order to correctly interpret the light curves.

The early ultraviolet, optical, and radio evolution of the soft X-ray transient GRO J0422+32

NASA Technical Reports Server (NTRS)

Shrader, C. R.; Wagner, R. Mark; Hjellming, R. M.; Han, X. H.; Starrfield, S. G.

1994-01-01

We have monitored the evolution of the transient X-ray source GRO J0422+32 from approximately 2 weeks postdiscovery into its early decline phase at ultraviolet, optical, and radio wavelengths. Optical and ultraviolet spectra exhibit numerous, but relatively weak, high-excitation emission lines such as those arising from He II, N III, N V, and C IV superposed on an intrinsically blue continuum. High-resolution optical spectroscopy reveals line profiles which are double peaked, and in the case of the higher order Balmer lines, superposed on a broad absorption profile. The early outburst optical-ultraviolet continuum energy distribution is well represented by a two power-law fit with a break at approximately equal 4000 A. Radio observations with the Very Large Array (VLA) reveal a flat-spectrum source, slowly increasing in intensity at the earliest epochs observed, followed by an approximate power-law decay light curve with an index of -1. Light curves for each wavelength domain are presented and discussed. Notable are the multiple secondary outbursts seen in the optical more than 1 year postdiscovery, and spectral changes associated with secondary rises seen in the radio and UV. We find that the ultraviolet and optical characteristics of GRO J0422+32 as well as its radio evolution, are similar to other recent well-observed soft X-ray transients (also called X-ray novae) such as Cen X-4, A0620-00 (V616 Mon), and Nova Muscae 1991 (GS 1124-683), suggesting that GRO J0422+32 is also a member of that subclass of low-mass X-ray binaries. We present definitive astrometric determination of the source position, and place an upper limit of R approximately equals 20 from our analysis of the Palomar Observatory Sky Survey (POSS). Additionally, we derive distinct values for color excess from analysis of the optical (E(B-V) = 0.23) and ultraviolet (E(B-V) = 0.4) data, suggesting an intrinsic magnitude of 19-19.5 for the progenitor if it is mid-K dwarf. This leads to a likely range

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.

Immune cell infiltration in malignant middle cerebral artery infarction: comparison with transient cerebral ischemia

PubMed Central

Chu, Hannah X; Kim, Hyun Ah; Lee, Seyoung; Moore, Jeffrey P; Chan, Christopher T; Vinh, Antony; Gelderblom, Mathias; Arumugam, Thiruma V; Broughton, Brad RS; Drummond, Grant R; Sobey, Christopher G

2014-01-01

We tested whether significant leukocyte infiltration occurs in a mouse model of permanent cerebral ischemia. C57BL6/J male mice underwent either permanent (3 or 24 hours) or transient (1 or 2 hours+22- to 23-hour reperfusion) middle cerebral artery occlusion (MCAO). Using flow cytometry, we observed ∼15,000 leukocytes (CD45+high cells) in the ischemic hemisphere as early as 3 hours after permanent MCAO (pMCAO), comprising ∼40% lymphoid cells and ∼60% myeloid cells. Neutrophils were the predominant cell type entering the brain, and were increased to ∼5,000 as early as 3 hours after pMCAO. Several cell types (monocytes, macrophages, B lymphocytes, CD8+ T lymphocytes, and natural killer cells) were also increased at 3 hours to levels sustained for 24 hours, whereas others (CD4+ T cells, natural killer T cells, and dendritic cells) were unchanged at 3 hours, but were increased by 24 hours after pMCAO. Immunohistochemical analysis revealed that leukocytes typically had entered and widely dispersed throughout the parenchyma of the infarct within 3 hours. Moreover, compared with pMCAO, there were ∼50% fewer infiltrating leukocytes at 24 hours after transient MCAO (tMCAO), independent of infarct size. Microglial cell numbers were bilaterally increased in both models. These findings indicate that a profound infiltration of inflammatory cells occurs in the brain early after focal ischemia, especially without reperfusion. PMID:24326388

Clinical- and imaging-based prediction of stroke risk after transient ischemic attack: the CIP model.

PubMed

Ay, Hakan; Arsava, E Murat; Johnston, S Claiborne; Vangel, Mark; Schwamm, Lee H; Furie, Karen L; Koroshetz, Walter J; Sorensen, A Gregory

2009-01-01

Predictive instruments based on clinical features for early stroke risk after transient ischemic attack suffer from limited specificity. We sought to combine imaging and clinical features to improve predictions for 7-day stroke risk after transient ischemic attack. We studied 601 consecutive patients with transient ischemic attack who had MRI within 24 hours of symptom onset. A logistic regression model was developed using stroke within 7 days as the response criterion and diffusion-weighted imaging findings and dichotomized ABCD(2) score (ABCD(2) >/=4) as covariates. Subsequent stroke occurred in 25 patients (5.2%). Dichotomized ABCD(2) score and acute infarct on diffusion-weighted imaging were each independent predictors of stroke risk. The 7-day risk was 0.0% with no predictor, 2.0% with ABCD(2) score >/=4 alone, 4.9% with acute infarct on diffusion-weighted imaging alone, and 14.9% with both predictors (an automated calculator is available at http://cip.martinos.org). Adding imaging increased the area under the receiver operating characteristic curve from 0.66 (95% CI, 0.57 to 0.76) using the ABCD(2) score to 0.81 (95% CI, 0.74 to 0.88; P=0.003). The sensitivity of 80% on the receiver operating characteristic curve corresponded to a specificity of 73% for the CIP model and 47% for the ABCD(2) score. Combining acute imaging findings with clinical transient ischemic attack features causes a dramatic boost in the accuracy of predictions with clinical features alone for early risk of stroke after transient ischemic attack. If validated in relevant clinical settings, risk stratification by the CIP model may assist in early implementation of therapeutic measures and effective use of hospital resources.

Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation

PubMed Central

2012-01-01

Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1β and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors. PMID:22731117

Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation.

PubMed

Chen, Chen-Wen; Chen, Qian-Bo; Ouyang, Qing; Sun, Ji-Hu; Liu, Fang-Ting; Song, Dian-Wen; Yuan, Hong-Bin

2012-06-25

Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1 β and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors.

Earthquake triggering by transient and static deformations

USGS Publications Warehouse

Gomberg, J.; Beeler, N.M.; Blanpied, M.L.; Bodin, P.

1998-01-01

Observational evidence for both static and transient near-field and far-field triggered seismicity are explained in terms of a frictional instability model, based on a single degree of freedom spring-slider system and rate- and state-dependent frictional constitutive equations. In this study a triggered earthquake is one whose failure time has been advanced by ??t (clock advance) due to a stress perturbation. Triggering stress perturbations considered include square-wave transients and step functions, analogous to seismic waves and coseismic static stress changes, respectively. Perturbations are superimposed on a constant background stressing rate which represents the tectonic stressing rate. The normal stress is assumed to be constant. Approximate, closed-form solutions of the rate-and-state equations are derived for these triggering and background loads, building on the work of Dieterich [1992, 1994]. These solutions can be used to simulate the effects of static and transient stresses as a function of amplitude, onset time t0, and in the case of square waves, duration. The accuracies of the approximate closed-form solutions are also evaluated with respect to the full numerical solution and t0. The approximate solutions underpredict the full solutions, although the difference decreases as t0, approaches the end of the earthquake cycle. The relationship between ??t and t0 differs for transient and static loads: a static stress step imposed late in the cycle causes less clock advance than an equal step imposed earlier, whereas a later applied transient causes greater clock advance than an equal one imposed earlier. For equal ??t, transient amplitudes must be greater than static loads by factors of several tens to hundreds depending on t0. We show that the rate-and-state model requires that the total slip at failure is a constant, regardless of the loading history. Thus a static load applied early in the cycle, or a transient applied at any time, reduces the stress

Isolation stress and chronic mild stress induced immobility in the defensive burying behavior and a transient increased ethanol intake in Wistar rats.

PubMed

Vázquez-León, Priscila; Martínez-Mota, Lucía; Quevedo-Corona, Lucía; Miranda-Páez, Abraham

2017-09-01

Stress can be experienced with or without adverse effects, of which anxiety and depression are two of the most important due to the frequent comorbidity with alcohol abuse in humans. Historically, stress has been considered a cause of drug use, particularly alcohol abuse due to its anxiolytic effects. In the present work we exposed male Wistar rats to two different stress conditions: single housing (social isolation, SI), and chronic mild stress (CMS). We compared both stressed groups to group-housed rats and rats without CMS (GH) to allow the determination of a clear behavioral response profile related to their respective endocrine stress response and alcohol intake pattern. We found that SI and CMS, to a greater extent, induced short-lasting increased sucrose consumption, a transient increase in serum corticosterone level, high latency/immobility, and low burying behavior in the defensive burying behavior (DBB) test, and a transient increase in alcohol intake. Thus, the main conclusion was that stress caused by both SI and CMS induced immobility in the DBB test and, subsequently, induced a transient increased voluntary ethanol intake in Wistar rats with a free-choice home-cage drinking paradigm. Copyright © 2017 Elsevier Inc. All rights reserved.

56Fe particle exposure results in a long-lasting increase in a cellular index of genomic instability and transiently suppresses adult hippocampal neurogenesis in vivo

NASA Astrophysics Data System (ADS)

DeCarolis, Nathan A.; Rivera, Phillip D.; Ahn, Francisca; Amaral, Wellington Z.; LeBlanc, Junie A.; Malhotra, Shveta; Shih, Hung-Ying; Petrik, David; Melvin, Neal R.; Chen, Benjamin P. C.; Eisch, Amelia J.

2014-07-01

The high-LET HZE particles from galactic cosmic radiation pose tremendous health risks to astronauts, as they may incur sub-threshold brain injury or maladaptations that may lead to cognitive impairment. The health effects of HZE particles are difficult to predict and unfeasible to prevent. This underscores the importance of estimating radiation risks to the central nervous system as a whole as well as to specific brain regions like the hippocampus, which is central to learning and memory. Given that neurogenesis in the hippocampus has been linked to learning and memory, we investigated the response and recovery of neurogenesis and neural stem cells in the adult mouse hippocampal dentate gyrus after HZE particle exposure using two nestin transgenic reporter mouse lines to label and track radial glia stem cells (Nestin-GFP and Nestin-CreERT2/R26R:YFP mice, respectively). Mice were subjected to 56Fe particle exposure (0 or 1 Gy, at either 300 or 1000 MeV/n) and brains were harvested at early (24 h), intermediate (7 d), and/or long time points (2-3 mo) post-irradiation. 56Fe particle exposure resulted in a robust increase in 53BP1+ foci at both the intermediate and long time points post-irradiation, suggesting long-term genomic instability in the brain. However, 56Fe particle exposure only produced a transient decrease in immature neuron number at the intermediate time point, with no significant decrease at the long time point post-irradiation. 56Fe particle exposure similarly produced a transient decrease in dividing progenitors, with fewer progenitors labeled at the early time point but equal number labeled at the intermediate time point, suggesting a recovery of neurogenesis. Notably, 56Fe particle exposure did not change the total number of nestin-expressing neural stem cells. These results highlight that despite the persistence of an index of genomic instability, 56Fe particle-induced deficits in adult hippocampal neurogenesis may be transient. These data support

Testing the ontogenetic base for the transient model of inflorescence development.

PubMed

Bull-Hereñu, Kester; Claßen-Bockhoff, Regine

2013-11-01

Current research in plant science has concentrated on revealing ontogenetic processes of key attributes in plant evolution. One recently discussed model is the 'transient model' successful in explaining some types of inflorescence architectures based on two main principles: the decline of the so called 'vegetativeness' (veg) factor and the transient nature of apical meristems in developing inflorescences. This study examines whether both principles find a concrete ontogenetic correlate in inflorescence development. To test the ontogenetic base of veg decline and the transient character of apical meristems the ontogeny of meristematic size in developing inflorescences was investigated under scanning electron microscopy. Early and late inflorescence meristems were measured and compared during inflorescence development in 13 eudicot species from 11 families. The initial size of the inflorescence meristem in closed inflorescences correlates with the number of nodes in the mature inflorescence. Conjunct compound inflorescences (panicles) show a constant decrease of meristematic size from early to late inflorescence meristems, while disjunct compound inflorescences present an enlargement by merging from early inflorescence meristems to late inflorescence meristems, implying a qualitative change of the apical meristems during ontogeny. Partial confirmation was found for the transient model for inflorescence architecture in the ontogeny: the initial size of the apical meristem in closed inflorescences is consistent with the postulated veg decline mechanism regulating the size of the inflorescence. However, the observed biphasic kinetics of the development of the apical meristem in compound racemes offers the primary explanation for their disjunct morphology, contrary to the putative exclusive transient mechanism in lateral axes as expected by the model.

Transient flow combustion

NASA Technical Reports Server (NTRS)

Tacina, R. R.

1984-01-01

Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

Nonlinear modeling and dynamic analysis of a hydro-turbine governing system in the process of sudden load increase transient

NASA Astrophysics Data System (ADS)

Li, Huanhuan; Chen, Diyi; Zhang, Hao; Wang, Feifei; Ba, Duoduo

2016-12-01

In order to study the nonlinear dynamic behaviors of a hydro-turbine governing system in the process of sudden load increase transient, we establish a novel nonlinear dynamic model of the hydro-turbine governing system which considers the elastic water-hammer model of the penstock and the second-order model of the generator. The six nonlinear dynamic transfer coefficients of the hydro-turbine are innovatively proposed by utilizing internal characteristics and analyzing the change laws of the characteristic parameters of the hydro-turbine governing system. Moreover, from the point of view of engineering, the nonlinear dynamic behaviors of the above system are exhaustively investigated based on bifurcation diagrams and time waveforms. More importantly, all of the above analyses supply theoretical basis for allowing a hydropower station to maintain a stable operation in the process of sudden load increase transient.

Terminal Transient Phase of Chaotic Transients

NASA Astrophysics Data System (ADS)

Lilienkamp, Thomas; Parlitz, Ulrich

2018-03-01

Transient chaos in spatially extended systems can be characterized by the length of the transient phase, which typically grows quickly with the system size (supertransients). For a large class of these systems, the chaotic phase terminates abruptly, without any obvious precursors in commonly used observables. Here we investigate transient spatiotemporal chaos in two different models of this class. By probing the state space using perturbed trajectories we show the existence of a "terminal transient phase," which occurs prior to the abrupt collapse of chaotic dynamics. During this phase the impact of perturbations is significantly different from the earlier transient and particular patterns of (non)susceptible regions in state space occur close to the chaotic trajectories. We therefore hypothesize that even without perturbations proper precursors for the collapse of chaotic transients exist, which might be highly relevant for coping with spatiotemporal chaos in cardiac arrhythmias or brain functionality, for example.

Early weaning increases aggression and stereotypic behaviour in cats.

PubMed

Ahola, Milla K; Vapalahti, Katariina; Lohi, Hannes

2017-09-04

Behaviour problems are common in companion felines, and problematic behaviour may be a sign of chronic stress. In laboratory animals, early weaning increases the risk for aggression, anxiety, and stereotypic behaviour. However, very few studies have focused on early weaning in one of the world's most popular pets, the domestic cat, although weaning soon after the critical period of socialisation is common practice. To study the effects of early weaning (<12 weeks) on behaviour, a large data set (N = 5726, 40 breeds) was collected from home-living domestic cats through a questionnaire survey. The results show that weaning before 8 weeks of age increases the risk for aggression, but not fearful behaviour. Moreover, cats weaned after 14 weeks of age have a lower probability for aggression towards strangers than early weaned cats and a lower probability for stereotypic behaviour (excessive grooming) than cats weaned at 12 weeks. The effect of weaning age on stereotypic behaviour is partially explained by the effects on aggression. These findings indicate that early weaning has a detrimental effect on behaviour, and suggest delayed weaning as a simple and inexpensive approach to significantly improve the welfare of millions of domestic cats.

Early events in geotropism of seedling shoots

NASA Technical Reports Server (NTRS)

Pickard, B. G.

1985-01-01

Developments during the first ten minutes of geotropic stimulation in plant seedling shoots are reviewed. Topics include induction and curvature; early processes; the relationship between auxin, electric field, calcium, and differential growth; gravity reception leading to Went-Cholodny transport; and comparison of root and shoot. Early processes reviewed are sedimentation of amyloplasts, release of ethylene, rise of electrical and auxin asymmetry, redistribution of calcium, asymmetric vascular transport, increase in tendency to deposit callose, and simulation of putative exocytotic voltage transients.

Profiling of barrier capacitance and spreading resistance using a transient linearly increasing voltage technique.

PubMed

Gaubas, E; Ceponis, T; Kusakovskij, J

2011-08-01

A technique for the combined measurement of barrier capacitance and spreading resistance profiles using a linearly increasing voltage pulse is presented. The technique is based on the measurement and analysis of current transients, due to the barrier and diffusion capacitance, and the spreading resistance, between a needle probe and sample. To control the impact of deep traps in the barrier capacitance, a steady state bias illumination with infrared light was employed. Measurements of the spreading resistance and barrier capacitance profiles using a stepwise positioned probe on cross sectioned silicon pin diodes and pnp structures are presented.

Recombinant modified vaccinia virus Ankara generating excess early double-stranded RNA transiently activates protein kinase R and triggers enhanced innate immune responses.

PubMed

Wolferstätter, Michael; Schweneker, Marc; Späth, Michaela; Lukassen, Susanne; Klingenberg, Marieken; Brinkmann, Kay; Wielert, Ursula; Lauterbach, Henning; Hochrein, Hubertus; Chaplin, Paul; Suter, Mark; Hausmann, Jürgen

2014-12-01

Double-stranded RNA (dsRNA) is an important molecular pattern associated with viral infection and is detected by various extra- and intracellular recognition molecules. Poxviruses have evolved to avoid producing dsRNA early in infection but generate significant amounts of dsRNA late in infection due to convergent transcription of late genes. Protein kinase R (PKR) is activated by dsRNA and triggers major cellular defenses against viral infection, including protein synthesis shutdown, apoptosis, and type I interferon (IFN-I) production. The poxviral E3 protein binds and sequesters viral dsRNA and is a major antagonist of the PKR pathway. We found that the highly replication-restricted modified vaccinia virus Ankara (MVA) engineered to produce excess amounts of dsRNA early in infection showed enhanced induction of IFN-β in murine and human cells in the presence of an intact E3L gene. IFN-β induction required a minimum overlap length of 300 bp between early complementary transcripts and was strongly PKR dependent. Excess early dsRNA produced by MVA activated PKR early but transiently in murine cells and induced enhanced systemic levels of IFN-α, IFN-γ, and other cytokines and chemokines in mice in a largely PKR-dependent manner. Replication-competent chorioallantois vaccinia virus Ankara (CVA) generating excess early dsRNA also enhanced IFN-I production and was apathogenic in mice even at very high doses but showed no in vitro host range defect. Thus, genetically adjuvanting MVA and CVA to generate excess early dsRNA is an effective method to enhance innate immune stimulation by orthopoxvirus vectors and to attenuate replicating vaccinia virus in vivo. Efficient cellular sensing of pathogen-specific components, including double-stranded RNA (dsRNA), is an important prerequisite of an effective antiviral immune response. The prototype poxvirus vaccinia virus (VACV) and its derivative modified vaccinia virus Ankara (MVA) produce dsRNA as a by-product of viral

Testing the ontogenetic base for the transient model of inflorescence development

PubMed Central

Bull-Hereñu, Kester; Claßen-Bockhoff, Regine

2013-01-01

Backgrounds and Aims Current research in plant science has concentrated on revealing ontogenetic processes of key attributes in plant evolution. One recently discussed model is the ‘transient model’ successful in explaining some types of inflorescence architectures based on two main principles: the decline of the so called ‘vegetativeness’ (veg) factor and the transient nature of apical meristems in developing inflorescences. This study examines whether both principles find a concrete ontogenetic correlate in inflorescence development. Methods To test the ontogenetic base of veg decline and the transient character of apical meristems the ontogeny of meristematic size in developing inflorescences was investigated under scanning electron microscopy. Early and late inflorescence meristems were measured and compared during inflorescence development in 13 eudicot species from 11 families. Key Results The initial size of the inflorescence meristem in closed inflorescences correlates with the number of nodes in the mature inflorescence. Conjunct compound inflorescences (panicles) show a constant decrease of meristematic size from early to late inflorescence meristems, while disjunct compound inflorescences present an enlargement by merging from early inflorescence meristems to late inflorescence meristems, implying a qualitative change of the apical meristems during ontogeny. Conclusions Partial confirmation was found for the transient model for inflorescence architecture in the ontogeny: the initial size of the apical meristem in closed inflorescences is consistent with the postulated veg decline mechanism regulating the size of the inflorescence. However, the observed biphasic kinetics of the development of the apical meristem in compound racemes offers the primary explanation for their disjunct morphology, contrary to the putative exclusive transient mechanism in lateral axes as expected by the model. PMID:23425784

Short-term depression and transient memory in sensory cortex.

PubMed

Gillary, Grant; Heydt, Rüdiger von der; Niebur, Ernst

2017-12-01

Persistent neuronal activity is usually studied in the context of short-term memory localized in central cortical areas. Recent studies show that early sensory areas also can have persistent representations of stimuli which emerge quickly (over tens of milliseconds) and decay slowly (over seconds). Traditional positive feedback models cannot explain sensory persistence for at least two reasons: (i) They show attractor dynamics, with transient perturbations resulting in a quasi-permanent change of system state, whereas sensory systems return to the original state after a transient. (ii) As we show, those positive feedback models which decay to baseline lose their persistence when their recurrent connections are subject to short-term depression, a common property of excitatory connections in early sensory areas. Dual time constant network behavior has also been implemented by nonlinear afferents producing a large transient input followed by much smaller steady state input. We show that such networks require unphysiologically large onset transients to produce the rise and decay observed in sensory areas. Our study explores how memory and persistence can be implemented in another model class, derivative feedback networks. We show that these networks can operate with two vastly different time courses, changing their state quickly when new information is coming in but retaining it for a long time, and that these capabilities are robust to short-term depression. Specifically, derivative feedback networks with short-term depression that acts differentially on positive and negative feedback projections are capable of dynamically changing their time constant, thus allowing fast onset and slow decay of responses without requiring unrealistically large input transients.

Amyotrophic lateral sclerosis immunoglobulins increase intracellular calcium in a motoneuron cell line.

PubMed

Colom, L V; Alexianu, M E; Mosier, D R; Smith, R G; Appel, S H

1997-08-01

A hybrid motoneuron cell line (VSC4.1) was used as a model system to study the relationship between alterations in intracellular calcium and subsequent cell death induced by immunoglobulin fractions purified from sera of patients with ALS. Using fluo-3 fluorescence imaging, immunoglobulins from 8 of 10 patients with ALS were found to induce transient increases in intracellular calcium ([Ca2+]i) in differentiated VSC4.1 cells. These transient [Ca2+]i increases required extracellular calcium entry through voltage-gated calcium channels sensitive to synthetic FTX and to high concentrations (>1 microM) of omega-agatoxin IVa. The incidence of transient [Ca2+]i increases induced by ALS immunoglobulins correlated with the extent of cytotoxicity induced by the same ALS immunoglobulins in parallel cultures of VSC4.1 cells. Furthermore, manipulations which blocked transient [Ca2+]i increases (addition of synthetic FTX or omega-agatoxin IVa) also inhibited the cytotoxic effects of ALS immunoglobulins. No transient calcium increases were observed in VSC4.1 cells following addition of immunoglobulins from 7 neurologic disease control patients. However, transient [Ca2+]i increases were observed following addition of immunoglobulins from 4 of 5 patients with myasthenia gravis (MG). The [Ca2+]i changes induced by MG immunoglobulins were not blocked by s-FTX, suggesting that they result from a different mechanism than those induced by ALS immunoglobulins. These results suggest that immunoglobulins from patients with ALS can induce transient increases in intracellular calcium in a motoneuron cell line, which may represent early events in the cascade of processes leading to injury and death of susceptible cells.

Real-Time Gas Identification by Analyzing the Transient Response of Capillary-Attached Conductive Gas Sensor

PubMed Central

Bahraminejad, Behzad; Basri, Shahnor; Isa, Maryam; Hambli, Zarida

2010-01-01

In this study, the ability of the Capillary-attached conductive gas sensor (CGS) in real-time gas identification was investigated. The structure of the prototype fabricated CGS is presented. Portions were selected from the beginning of the CGS transient response including the first 11 samples to the first 100 samples. Different feature extraction and classification methods were applied on the selected portions. Validation of methods was evaluated to study the ability of an early portion of the CGS transient response in target gas (TG) identification. Experimental results proved that applying extracted features from an early part of the CGS transient response along with a classifier can distinguish short-chain alcohols from each other perfectly. Decreasing time of exposition in the interaction between target gas and sensing element improved the reliability of the sensor. Classification rate was also improved and time of identification was decreased. Moreover, the results indicated the optimum interval of the early transient response of the CGS for selecting portions to achieve the best classification rates. PMID:22219666

Increased Migration of Monocytes in Essential Hypertension Is Associated with Increased Transient Receptor Potential Channel Canonical Type 3 Channels

PubMed Central

Chen, Jing; Zhong, Jian; Yu, Hao; Xu, Xingsen; He, Hongbo; Yan, Zhencheng; Scholze, Alexandra; Liu, Daoyan; Zhu, Zhiming; Tepel, Martin

2012-01-01

Increased transient receptor potential canonical type 3 (TRPC3) channels have been observed in patients with essential hypertension. In the present study we tested the hypothesis that increased monocyte migration is associated with increased TRPC3 expression. Monocyte migration assay was performed in a microchemotaxis chamber using chemoattractants formylated peptide Met-Leu-Phe (fMLP) and tumor necrosis factor-α (TNF-α). Proteins were identified by immunoblotting and quantitative in-cell Western assay. The effects of TRP channel-inhibitor 2–aminoethoxydiphenylborane (2-APB) and small interfering RNA knockdown of TRPC3 were investigated. We observed an increased fMLP-induced migration of monocytes from hypertensive patients compared with normotensive control subjects (246±14% vs 151±10%). The TNF-α-induced migration of monocytes in patients with essential hypertension was also significantly increased compared to normotensive control subjects (221±20% vs 138±18%). In the presence of 2-APB or after siRNA knockdown of TRPC3 the fMLP-induced monocyte migration was significantly blocked. The fMLP-induced changes of cytosolic calcium were significantly increased in monocytes from hypertensive patients compared to normotensive control subjects. The fMLP-induced monocyte migration was significantly reduced in the presence of inhibitors of tyrosine kinase and phosphoinositide 3-kinase. We conclude that increased monocyte migration in patients with essential hypertension is associated with increased TRPC3 channels. PMID:22438881

Grazing disturbance increases transient but decreases persistent soil seed bank.

PubMed

Ma, Miaojun; Walck, Jeffrey L; Ma, Zhen; Wang, Lipei; Du, Guozhen

2018-04-30

Very few studies have examined whether the impacts of grazing disturbance on soil seed banks occur directly or indirectly through aboveground vegetation and soil properties. The potential role of the seed bank in alpine wetland restoration is also unknown. We used SEM (structural equation modeling) to explore the direct effect of grazing disturbance on the seed bank and the indirect effect through aboveground vegetation and soil properties. We also studied the role of the seed bank on the restoration potential in wetlands with various grazing intensities: low (fenced, winter grazed only), medium (seasonally grazed), and high (whole-year grazed). For the seed bank, species richness and density per plot showed no difference among grazing intensities for each depth (0-5, 5-10, 10-15 cm) and for the whole depth (0-15 cm) in spring and summer. There was no direct effect of grazing disturbance on seed bank richness and density both in spring and summer, and also no indirect effect on the seed bank through its direct effect on vegetation richness and abundance. Grazing disturbance indirectly increased spring seed bank density but decreased summer seed bank density through its direct effect (negative correlation) on soil moisture and total nitrogen and its indirect effect on vegetation abundance. Species composition of the vegetation changed with grazing regime, but that of the seed bank did not. An increased trend of similarity between the seed bank and aboveground vegetation with increased grazing disturbance was found in the shallow depth and in the whole depth only in spring. Although there was almost no change in seed bank size with grazing intensities, grazing disturbance increased the quantity of transient seeds but decreased persistent seeds. Persistent seeds stored in the soil could play a crucial role in vegetation regeneration and in restoration of degraded wetland ecosystems. The seed bank should be an integral part of alpine wetland restoration programs. �

Techniques for improving transients in learning control systems

NASA Technical Reports Server (NTRS)

Chang, C.-K.; Longman, Richard W.; Phan, Minh

1992-01-01

A discrete modern control formulation is used to study the nature of the transient behavior of the learning process during repetitions. Several alternative learning control schemes are developed to improve the transient performance. These include a new method using an alternating sign on the learning gain, which is very effective in limiting peak transients and also very useful in multiple-input, multiple-output systems. Other methods include learning at an increasing number of points progressing with time, or an increasing number of points of increasing density.

Energetic ion leakage from foreshock transient cores

NASA Astrophysics Data System (ADS)

Liu, Terry Z.; Angelopoulos, Vassilis; Hietala, Heli

2017-07-01

Earth's foreshock is filled with backstreaming particles that can interact with the ambient solar wind and its discontinuities to form foreshock transients. Many foreshock transients have a core with low dynamic pressure that can significantly perturb the bow shock and the magnetosphere-ionosphere system. Foreshock transients have also been recently recognized as sites of particle acceleration, which may be important for seeding the parent shock with energetic particles. A relevant step of this seeding would be energetic ion leakage into the surrounding foreshock environment. On the other hand, such leakage would also suppress the energetic particle flux contrast across foreshock transients' boundaries masking their perceived contribution to ion energization. To further examine this hypothesis of ion leakage, we report on multipoint case studies of three foreshock transient events selected from a large database. The cases were selected to exemplify, in increasing complexity, the nature and consequences of energetic ion leakage. Ion energy dispersion, observed upstream and/or downstream of the foreshock transients, is explained with a simple, ballistic model of ions leaking from the foreshock transients. Larger energies are required for leaked ions to reach the spacecraft as the distance between the transient and spacecraft increases. Our model, which explains well the observed ion energy dispersion and velocity distributions, can also be used to reveal the shape of the foreshock transients in three dimensions. Our results suggest that ion leakage from foreshock transient cores needs to be accounted for both in statistical studies and in global models of ion acceleration under quasi-parallel foreshock conditions.

Rheumatoid arthritis significantly increased recurrence risk after ischemic stroke/transient ischemic attack.

PubMed

Chen, Yih-Ru; Hsieh, Fang-I; Lien, Li-Ming; Hu, Chaur-Jong; Jeng, Jiann-Shing; Peng, Giia-Sheun; Tang, Sung-Chun; Chi, Nai-Fang; Sung, Yueh-Feng; Chiou, Hung-Yi

2018-06-02

The effect of RA on recurrent stroke is unknown. Therefore, we examined effects of rheumatoid arthritis (RA) on risk of stroke recurrence and investigated the interaction between RA and traditional cardiovascular risk factors on recurrence risk after ischemic stroke (IS) or transient ischemic attack (TIA). Of 3190 patients with IS or TIA recruited in this cohort study, 638 were comorbid with RA and 2552 without RA. Stroke recurrence, RA, lifestyle, lipid variables and other comorbidities were identified through linkage between a nationwide stroke database in Taiwan and the National Health Insurance claims database. Cox proportional hazard models with competing risk adjustment were used to evaluate the relationship between RA and recurrent stroke. Patients with RA showed a significantly increased risk of recurrent stroke, particular in recurrent IS/TIA. The increased risk of recurrent IS/TIA in RA patients may through the changes of triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C) ratio. A positive additive interaction was observed between RA and current smoking on the risk of recurrent IS/TIA. Significantly increased risks for recurrent IS/TIA were observed among RA patients who smoked > 40 years or those who smoked > 20 cigarettes/day. This study provides the first evidence that RA significantly increased recurrence IS/TIA risk. The changes of TG/HDL-C ratio may play some roles in the recurrence IS/TIA risk in RA patients. In addition, our results suggest that smoking increases the risk of recurrent IS/TIA in RA patients and reinforces the need for aggressive smoking cessation efforts in RA patients.

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.

Transient deep-water oxygenation in the early Cambrian Nanhua Basin, South China

NASA Astrophysics Data System (ADS)

Cheng, Meng; Li, Chao; Zhou, Lian; Feng, LianJun; Algeo, Thomas J.; Zhang, FeiFei; Romaniello, Stephen; Jin, ChengSheng; Ling, HongFei; Jiang, ShaoYong

2017-08-01

Many late Neoproterozoic to early Cambrian fossils of multicellular eukaryotes, including those of benthic animals, are found preserved under anoxic and even euxinic bottom-water conditions, which is contradictory to the consensus that oxygen is essential to eukaryotes. To investigate this conundrum, we conducted an integrated study of iron speciation, redox-sensitive trace elements, and Mo isotopes (δ98Mo) on the black shale interval of the lower Cambrian Hetang Formation (∼535-521 Ma) at Lantian, South China, in which benthic sponge fossils are abundant in the lower member (LM) but absent in the upper member (UM). Iron speciation data point to uniformly anoxic-ferruginous conditions in the LM and euxinic conditions in the UM, whereas the trace-element and δ98Mo data show greater secular variation in redox conditions. The LM shows higher mean trace element concentrations (Mo: 108 ppm, U: 36 ppm, V: 791 ppm) and lower and more variable δ98Mo (+0.13 to +1.76‰) relative to the UM (Mo: 45 ppm, U: 18 ppm, V: 265 ppm, δ98Mo: +1.59 to +1.67‰), and ratios of redox-sensitive trace element concentrations to total organic carbon are significantly more variable and higher on average in the LM relative to the UM. The appearance of sponge fossils and lower δ98Mo values correlate strongly with gray (i.e., lighter-colored) layers in the LM. These patterns can best be interpreted as recording mainly euxinic conditions throughout deposition of the study units, with more intense background euxinia in the LM relative to the UM, but also with frequent transient oxygenation events in the LM that do not appear in the UM. The transient oxygenation events of the LM led to the initial colonization of the deep Nanhua Basin by sponges, and the termination of these events in the UM caused sponge faunas to disappear until a general rise in O2 levels later in the Cambrian permitted their return to deeper-water habitats. Our study also illustrates that multiple geochemical and

Selective Vulnerability of Specific Retinal Ganglion Cell Types and Synapses after Transient Ocular Hypertension.

PubMed

Ou, Yvonne; Jo, Rebecca E; Ullian, Erik M; Wong, Rachel O L; Della Santina, Luca

2016-08-31

Key issues concerning ganglion cell type-specific loss and synaptic changes in animal models of experimental glaucoma remain highly debated. Importantly, changes in the structure and function of various RGC types that occur early, within 14 d after acute, transient intraocular pressure elevation, have not been previously assessed. Using biolistic transfection of individual RGCs and multielectrode array recordings to measure light responses in mice, we examined the effects of laser-induced ocular hypertension on the structure and function of a subset of RGCs. Among the α-like RGCs studied, αOFF-transient RGCs exhibited higher rates of cell death, with corresponding reductions in dendritic area, dendritic complexity, and synapse density. Functionally, OFF-transient RGCs displayed decreases in spontaneous activity and receptive field size. In contrast, neither αOFF-sustained nor αON-sustained RGCs displayed decreases in light responses, although they did exhibit a decrease in excitatory postsynaptic sites, suggesting that synapse loss may be one of the earliest signs of degeneration. Interestingly, presynaptic ribbon density decreased to a greater degree in the OFF sublamina of the inner plexiform layer, corroborating the hypothesis that RGCs with dendrites stratifying in the OFF sublamina may be damaged early. Indeed, OFF arbors of ON-OFF RGCs lose complexity more rapidly than ON arbors. Our results reveal type-specific differences in RGC responses to injury with a selective vulnerability of αOFF-transient RGCs, and furthermore, an increased susceptibility of synapses in the OFF sublamina. The selective vulnerability of specific RGC types offers new avenues for the design of more sensitive functional tests and targeted neuroprotection. Conflicting reports regarding the selective vulnerability of specific retinal ganglion cell (RGC) types in glaucoma exist. We examine, for the first time, the effects of transient intraocular pressure elevation on the structure

Examination of age-related epigenetic changes following early-life exposure to dichloroacetic acid

EPA Science Inventory

Recent studies have shown that transient early-life exposure to dichloroacetic acid (DCA), a pyruvate analog and metabolic reprogramming agent, increases liver cancer incidence in older mice. This carcinogenic effect is not associated with direct mutagenicity, persistent cytotoxi...

Circuit transients due to negative bias arcs-II. [on solar cell power systems in low earth orbit

NASA Technical Reports Server (NTRS)

Metz, R. N.

1986-01-01

Two new models of negative-bias arcing on a solar cell power system in Low Earth Orbit are presented. One is an extended, analytical model and the other is a non-linear, numerical model. The models are based on an earlier analytical model in which the interactions between solar cell interconnects and the space plasma as well as the parameters of the power circuit are approximated linearly. Transient voltages due to arcs struck at the negative thermal of the solar panel are calculated in the time domain. The new models treat, respectively, further linear effects within the solar panel load circuit and non-linear effects associated with the plasma interactions. Results of computer calculations with the models show common-mode voltage transients of the electrically floating solar panel struck by an arc comparable to the early model but load transients that differ substantially from the early model. In particular, load transients of the non-linear model can be more than twice as great as those of the early model and more than twenty times as great as the extended, linear model.

Transient increases in methylbutenol emission following partial defoliation of Pinus ponderosa

NASA Astrophysics Data System (ADS)

Gray, Dennis W.

Methybutenol (MBO or 2-methyl-3-butene-2-ol) is a five-carbon alcohol produced and emitted in large amounts by many species of pine native to Western North America. Upon entering the atmosphere, MBO may engage in a series of chemical reactions which may ultimately lead to the production of tropospheric ozone which is a damaging pollutant. While the physical factors controlling MBO emission are well understood, the ecological factors controlling MBO emission have yet to be addressed. This study examines the response of MBO emission from Pinus ponderosa to herbivory simulated by needle clipping. Following defoliation early in the season, MBO emission from some plants tripled but similar increase did not occur later in the season. Anecdotal evidence suggests that the variable response of MBO emission to defoliation may have been due to the action of insect herbivores early in the season, or may have been due to phenological changes in the plants over the course of the season.

Small gravitationally elicited voltage transients in pea stems

NASA Technical Reports Server (NTRS)

Pickard, B. G.

1984-01-01

Decapitated veritcal stem segments were observed for 45 min, noting the number of transients mu V for each 5-min interval. Results for two sets of stem segments are plotted. The average frequencies were 0.72 + or -0.05 and 0.66 + or - 0.04 per 5 min. One set of segments was swiveled gently to the horizontal position; then, recording continued for another 90 min. Transients continued in the vertical controls at a closely similar average rate 0.78 + or - 0.04 per 5 min. However, after the first 5-min interval the horizontally placed plants exhibited transients at an increased average rate of 1.08 + or - 0.04 per 5 min. The frequency of transients also increased following horizontal placement of intact shoots. However, it appears that this increase had two components: one due to gravity reception, and one due to the redistribution of indolacetic acid (IAA) believed to mediate gravitropic curvature (or, more specifically, to the increase of IAA in the lower tissue.

Early testosterone replacement attenuates intracellular calcium dyshomeostasis in the heart of testosterone-deprived male rats.

PubMed

Weerateerangkul, Punate; Shinlapawittayatorn, Krekwit; Palee, Siripong; Apaijai, Nattayaporn; Chattipakorn, Siriporn C; Chattipakorn, Nipon

2017-11-01

Testosterone deficiency in elderly men increases the risk of cardiovascular disease. In bilateral orchiectomized (ORX) animals, impaired cardiac Ca 2+ regulation was observed, and this impairment could be improved by testosterone replacement, indicating the important role of testosterone in cardiac Ca 2+ regulation. However, the temporal changes of Ca 2+ dyshomeostasis in testosterone-deprived conditions are unclear. Moreover, the effects of early vs. late testosterone replacement are unknown. We hypothesized that the longer the deprivation of testosterone, the greater the impairment of cardiac Ca 2+ homeostasis, and that early testosterone replacement can effectively reduce this adverse effect. Male Wistar rats were randomly divided into twelve groups, four sets of three. The first set were ORX for 2, 4 and 8 weeks, the second set were sham-operated groups of the same periods, the third set were ORX for 8 weeks coupled with a subcutaneous injection of vehicle (control), testosterone during weeks 1-8 (early replacement) or testosterone during weeks 5-8 (late replacement), and finally the 12-week sham-operated, ORX and ORX treated with testosterone groups. Cardiac Ca 2+ transients (n=4-5/group), L-type calcium current (I Ca-L ) (n=4/group), Ca 2+ regulatory proteins (n=6/group) and cardiac function (n=5/group) were determined. In the ORX rats, impaired cardiac Ca 2+ transients and reduced I Ca-L were observed initially 4 weeks after ORX as shown by decreased Ca 2+ transient amplitude, rising rate and maximum and average decay rates. No alteration of Ca 2+ regulatory proteins such as the L-type Ca 2+ channels, ryanodine receptor type 2, Na + -Ca 2+ exchangers and SERCA2a were observed. Early testosterone replacement markedly improved cardiac Ca 2+ transients, whereas late testosterone replacement did not. The cardiac contractility was also improved after early testosterone replacement. Impaired cardiac Ca 2+ homeostasis is time-dependent after testosterone

Recurrent transient ischaemic attack and early risk of stroke: data from the PROMAPA study.

PubMed

Purroy, Francisco; Jiménez Caballero, Pedro Enrique; Gorospe, Arantza; Torres, María José; Alvarez-Sabin, José; Santamarina, Estevo; Martínez-Sánchez, Patricia; Cánovas, David; Freijo, María José; Egido, Jose Antonio; Ramírez-Moreno, Jose M; Alonso-Arias, Arantza; Rodríguez-Campello, Ana; Casado, Ignacio; Delgado-Mederos, Raquel; Martí-Fàbregas, Joan; Fuentes, Blanca; Silva, Yolanda; Quesada, Helena; Cardona, Pere; Morales, Ana; de la Ossa, Natalia Pérez; García-Pastor, Antonio; Arenillas, Juan F; Segura, Tomas; Jiménez, Carmen; Masjuán, Jaime

2013-06-01

Many guidelines recommend urgent intervention for patients with two or more transient ischaemic attacks (TIAs) within 7 days (multiple TIAs) to reduce the early risk of stroke. To determine whether all patients with multiple TIAs have the same high early risk of stroke. Between April 2008 and December 2009, we included 1255 consecutive patients with a TIA from 30 Spanish stroke centres (PROMAPA study). We prospectively recorded clinical characteristics. We also determined the short-term risk of stroke (at 7 and 90 days). Aetiology was categorised using the TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. Clinical variables and extracranial vascular imaging were available and assessed in 1137/1255 (90.6%) patients. 7-Day and 90-day stroke risk were 2.6% and 3.8%, respectively. Large-artery atherosclerosis (LAA) was confirmed in 190 (16.7%) patients. Multiple TIAs were seen in 274 (24.1%) patients. Duration <1 h (OR=2.97, 95% CI 2.20 to 4.01, p<0.001), LAA (OR=1.92, 95% CI 1.35 to 2.72, p<0.001) and motor weakness (OR=1.37, 95% CI 1.03 to 1.81, p=0.031) were independent predictors of multiple TIAs. The subsequent risk of stroke in these patients at 7 and 90 days was significantly higher than the risk after a single TIA (5.9% vs 1.5%, p<0.001 and 6.8% vs 3.0%, respectively). In the logistic regression model, among patients with multiple TIAs, no variables remained as independent predictors of stroke recurrence. According to our results, multiple TIAs within 7 days are associated with a greater subsequent risk of stroke than after a single TIA. Nevertheless, we found no independent predictor of stroke recurrence among these patients.

A pulse of blue light induces a transient increase in activity of apoplastic K+ in laminar pulvinus of Phaseolus vulgaris L.

PubMed

Okazaki, Y; Azuma, K; Nishizaki, Y

2000-02-01

A pulse of blue light induced both a transient increase in activity of apoplastic K+ and membrane depolarization in laminar pulvinus of Phaseolus vulgaris L. This shows that blue-light-induced net efflux of K+ from motor cells is closely related to membrane depolarization.

TRANSIENT AMORPHOUS CALCIUM PHOSPHATE IN FORMING ENAMEL

PubMed Central

Beniash, Elia; Metzler, Rebecca A.; Lam, Raymond S.K.; Gilbert, P.U.P.A.

2009-01-01

Enamel, the hardest tissue in the body, begins as a three-dimensional network of nanometer size mineral particles, suspended in a protein gel. This mineral network serves as a template for mature enamel formation. To further understand the mechanisms of enamel formation we characterized the forming enamel mineral at an early secretory stage using x-ray absorption near-edge structure (XANES) spectromicroscopy, transmission electron microscopy (TEM), FTIR microspectroscopy and polarized light microscopy. We show that the newly formed enamel mineral is amorphous calcium phosphate (ACP), which eventually transforms into apatitic crystals. Interestingly, the size, shape and spatial organization of these amorphous mineral particles and older crystals are essentially the same, indicating that the mineral morphology and organization in enamel is determined prior to its crystallization. Mineralization via transient amorphous phases has been previously reported in chiton teeth, mollusk shells, echinoderm spicules and spines, and recent reports strongly suggest the presence transient amorphous mineral in forming vertebrate bones. The present finding of transient ACP in murine tooth enamel suggests that this strategy might be universal. PMID:19217943

Early and delayed long-term transcriptional changes and short-term transient responses during cold acclimation in olive leaves

PubMed Central

Leyva-Pérez, María de la O; Valverde-Corredor, Antonio; Valderrama, Raquel; Jiménez-Ruiz, Jaime; Muñoz-Merida, Antonio; Trelles, Oswaldo; Barroso, Juan Bautista; Mercado-Blanco, Jesús; Luque, Francisco

2015-01-01

Low temperature severely affects plant growth and development. To overcome this constraint, several plant species from regions having a cool season have evolved an adaptive response, called cold acclimation. We have studied this response in olive tree (Olea europaea L.) cv. Picual. Biochemical stress markers and cold-stress symptoms were detected after the first 24 h as sagging leaves. After 5 days, the plants were found to have completely recovered. Control and cold-stressed plants were sequenced by Illumina HiSeq 1000 paired-end technique. We also assembled a new olive transcriptome comprising 157,799 unigenes and found 6,309 unigenes differentially expressed in response to cold. Three types of response that led to cold acclimation were found: short-term transient response, early long-term response, and late long-term response. These subsets of unigenes were related to different biological processes. Early responses involved many cold-stress-responsive genes coding for, among many other things, C-repeat binding factor transcription factors, fatty acid desaturases, wax synthesis, and oligosaccharide metabolism. After long-term exposure to cold, a large proportion of gene down-regulation was found, including photosynthesis and plant growth genes. Up-regulated genes after long-term cold exposure were related to organelle fusion, nucleus organization, and DNA integration, including retrotransposons. PMID:25324298

Transient Diabetes Insipidus Following Thermal Burn; A Case Report and Literature Review.

PubMed

Dash, Suvashis; Ghosh, Shibajyoti

2017-10-01

Diabetes insipidus is a disease charaterised by increased urine production and thrist. Neurogenic diabetes insipidus following head trauma,autoimmune disease and infection is quite common but diabetes insipidus following thermal burn injury is a rare complication.We should know about this complication as its management need a comprehensive approach for satisfactory outcome. Thermal burn can cause different complications in early post burn period like electrolyte imbalance, dehydration, acute renal failure, but diabetes insipidus is a very rare and unusual complication that may come across in thermal burn. We should be aware about this condition to prevent and treat mortality and morbidity in burn patients. We have reported a case of transient diabetes insipidus in a patient of thermal burn in early post burn period. Patient was treated accordingly, leading to complete recovery.

Transient response of sap flow to wind speed.

PubMed

Chu, Chia R; Hsieh, Cheng-I; Wu, Shen-Yuang; Phillips, Nathan G

2009-01-01

Transient responses of sap flow to step changes in wind speed were experimentally investigated in a wind tunnel. A Granier-type sap flow sensor was calibrated and tested in a cylindrical tube for analysis of its transient time response. Then the sensor was used to measure the transient response of a well-watered Pachira macrocarpa plant to wind speed variations. The transient response of sap flow was described using the resistance-capacitance model. The steady sap flow rate increased as the wind speed increased at low wind speeds. Once the wind speed exceeded 8.0 m s(-1), the steady sap flow rate did not increase further. The transpiration rate, measured gravimetrically, showed a similar trend. The response of nocturnal sap flow to wind speed variation was also measured and compared with the results in the daytime. Under the same wind speed, the steady sap flow rate was smaller than that in the daytime, indicating differences between diurnal and nocturnal hydraulic function, and incomplete stomatal closure at night. In addition, it was found that the temporal response of the Granier sensor is fast enough to resolve the transient behaviour of water flux in plant tissue.

Transient times in linear metabolic pathways under constant affinity constraints.

PubMed

Lloréns, M; Nuño, J C; Montero, F

1997-10-15

In the early seventies, Easterby began the analytical study of transition times for linear reaction schemes [Easterby (1973) Biochim. Biophys. Acta 293, 552-558]. In this pioneer work and in subsequent papers, a state function (the transient time) was used to measure the period before the stationary state, for systems constrained to work under both constant and variable input flux, was reached. Despite the undoubted usefulness of this quantity to describe the time-dependent features of these kinds of systems, its application to the study of chemical reactions under other constraints is questionable. In the present work, a generalization of these magnitudes to linear metabolic pathways functioning under a constant-affinity constraint is carried out. It is proved that classical definitions of transient times do not reflect the actual properties of the transition to the steady state in systems evolving under this restriction. Alternatively, a more adequate framework for interpretation of the transient times for systems with both constant and variable input flux is suggested. Within this context, new definitions that reflect more accurately the transient characteristics of constant affinity systems are stated. Finally, the meaning of these transient times is discussed.

Increasing Early Childhood Preservice Teachers' Intercultural Sensitivity through the ABCs

ERIC Educational Resources Information Center

Monroe, Lisa; Ruan, Jiening

2018-01-01

While the early childhood student population has become increasingly diverse in the U.S., its teaching force remains primarily European American. The diverse student population demands that early childhood educators possess intercultural sensitivity in order to teach their culturally diverse learners effectively. This study examined the…

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

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.

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

Update on the Commensal VLA Low-band Ionospheric and Transient Experiment (VLITE)

NASA Astrophysics Data System (ADS)

Kassim, Namir E.; Clarke, Tracy E.; Ray, Paul S.; Polisensky, Emil; Peters, Wendy M.; Giacintucci, Simona; Helmboldt, Joseph F.; Hyman, Scott D.; Brisken, Walter; Hicks, Brian; Deneva, Julia S.

2017-01-01

The JVLA Low-band Ionospheric and Transient Experiment (VLITE) is a commensal observing system on the NRAO JVLA. The separate optical path of the prime-focus sub-GHz dipole feeds and the Cassegrain-focus GHz feeds provided an opportunity to expand the simultaneous frequency operation of the JVLA through joint observations across both systems. The low-band receivers on 10 JVLA antennas are outfitted with dedicated samplers and use spare fibers to transport the 320-384 MHz band to the VLITE correlator. The initial phase of VLITE uses a custom-designed real-time DiFX software correlator to produce autocorrelations, as well as parallel and cross-hand cross-correlations from the linear dipole feeds. NRL and NRAO have worked together to explore the scientific potential of the commensal low frequency system for ionospheric remote sensing, astrophysics and transients. VLITE operates at nearly 70% wall time with roughly 6200 hours of JVLA time recorded each year.VLITE data are used in real-time for ionospheric research and are transferred daily to NRL for processing in the astrophysics and transient pipelines. These pipelines provide automated radio frequency interference excision, calibration, imaging and self-calibration of data.We will review early scientific results from VLITE across all three science focus areas, including the ionosphere, slow (> 1 sec) transients, and astrophysics. We also discuss the future of the project, that includes its planned expansion to eVLITE including the addition of more antennas, and a parallel capability to search for fast (< 1 sec), dispersed transients, such as Fast Radio Bursts and Rotating Radio Transients. We will also present early results of commissioning tests to utilize VLITE data products to complement NRAO’s 3 GHz VLA Sky Survey (VLASS). Revised pipelines are under development for operation during the on-the-fly operation mode of the sky survey.

Apparent dispersion in transient groundwater flow

USGS Publications Warehouse

Goode, Daniel J.; Konikow, Leonard F.

1990-01-01

This paper investigates the effects of large-scale temporal velocity fluctuations, particularly changes in the direction of flow, on solute spreading in a two-dimensional aquifer. Relations for apparent longitudinal and transverse dispersivity are developed through an analytical solution for dispersion in a fluctuating, quasi-steady uniform flow field, in which storativity is zero. For transient flow, spatial moments are evaluated from numerical solutions. Ignored or unknown transients in the direction of flow primarily act to increase the apparent transverse dispersivity because the longitudinal dispersivity is acting in a direction that is not the assumed flow direction. This increase is a function of the angle between the transient flow vector and the assumed steady state flow direction and the ratio of transverse to longitudinal dispersivity. The maximum effect on transverse dispersivity occurs if storativity is assumed to be zero, such that the flow field responds instantly to boundary condition changes.

Association Between Transient Newborn Hypoglycemia and Fourth-Grade Achievement Test Proficiency: A Population-Based Study.

PubMed

Kaiser, Jeffrey R; Bai, Shasha; Gibson, Neal; Holland, Greg; Lin, Tsai Mei; Swearingen, Christopher J; Mehl, Jennifer K; ElHassan, Nahed O

2015-10-01

Prolonged neonatal hypoglycemia is associated with poor long-term neurocognitive function. However, little is known about an association between early transient newborn hypoglycemia and academic achievement. To determine if early (within the first 3 hours of life) transient hypoglycemia (a single initial low glucose concentration, followed by a second value above a cutoff) is associated with subsequent poor academic performance. A retrospective population-based cohort study of all infants born between January 1, 1998, and December 31, 1998, at the University of Arkansas for Medical Sciences who had at least 1 recorded glucose concentration (a universal newborn glucose screening policy was in effect) was conducted. Medical record data from newborns with normoglycemia or transient hypoglycemia were matched with their student achievement test scores in 2008 from the Arkansas Department of Education and anonymized. Logistic regression models were developed to evaluate the association between transient hypoglycemia and school-age achievement test proficiency based on perinatal factors. Common hypoglycemia cutoffs of a glucose level less than 35 mg/dL (primary) and less than 40 and 45 mg/dL (secondary) were investigated. All 1943 normoglycemic and transiently hypoglycemic infants (23-42 weeks' gestation) were eligible for inclusion in the study. Infants with prolonged hypoglycemia, congenital anomalies, or chromosomal abnormalities were excluded from the study. Hypoglycemia as a newborn. The primary outcome was proficiency on fourth-grade literacy and mathematics achievement tests at age 10 years. We hypothesized a priori that newborns with early transient hypoglycemia would be less proficient on fourth-grade achievement tests compared with normoglycemic newborns. Perinatal data were matched with fourth-grade achievement test scores in 1395 newborn-student pairs (71.8%). Transient hypoglycemia (glucose level <35, <40, and <45 mg/dL) was observed in 6.4% (89 of 1395), 10

Transient increase in sAPPα secretion in response to Aβ1-42 oligomers: an attempt of neuronal self-defense?

PubMed

Rose, Christiane; Dorard, Emilie; Audrain, Mickael; Gorisse-Hussonnois, Lucie; Cartier, Nathalie; Braudeau, Jérome; Allinquant, Bernadette

2018-01-01

Amyloid precursor protein (APP), a key molecule of Alzheimer disease, is metabolized in 2 antagonist pathways generating the soluble APP alpha (sAPPα) having neuroprotective properties and the beta amyloid (Aβ) peptide at the origin of neurotoxic oligomers, particularly Aβ1-42. Whether extracellular Aβ1-42 oligomers modulate the formation and secretion of sAPPα is not known. We report here that the addition of Aβ1-42 oligomers to primary cortical neurons induced a transient increase in α-secretase activity and secreted sAPPα 6-9 hours later. Preventing the generation of sAPPα by using small interfering RNAs (siRNAs) for the α-secretases ADAM10 and ADAM17 or for APP led to increased Aβ1-42 oligomer-induced cell death after 24 hours. Neuronal injuries due to oxidative stress or growth factor deprivation also generated sAPPα 7 hours later. Finally, acute injection of Aβ1-42 oligomers into wild-type mouse hippocampi induced transient secretion of sAPPα 48-72 hours later. Altogether, these data suggest that neurons respond to stress by generating sAPPα for their survival. These data must be taken into account when interpreting sAPPα levels as a biomarker in neurological disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Early and delayed long-term transcriptional changes and short-term transient responses during cold acclimation in olive leaves.

PubMed

Leyva-Pérez, María de la O; Valverde-Corredor, Antonio; Valderrama, Raquel; Jiménez-Ruiz, Jaime; Muñoz-Merida, Antonio; Trelles, Oswaldo; Barroso, Juan Bautista; Mercado-Blanco, Jesús; Luque, Francisco

2015-02-01

Low temperature severely affects plant growth and development. To overcome this constraint, several plant species from regions having a cool season have evolved an adaptive response, called cold acclimation. We have studied this response in olive tree (Olea europaea L.) cv. Picual. Biochemical stress markers and cold-stress symptoms were detected after the first 24 h as sagging leaves. After 5 days, the plants were found to have completely recovered. Control and cold-stressed plants were sequenced by Illumina HiSeq 1000 paired-end technique. We also assembled a new olive transcriptome comprising 157,799 unigenes and found 6,309 unigenes differentially expressed in response to cold. Three types of response that led to cold acclimation were found: short-term transient response, early long-term response, and late long-term response. These subsets of unigenes were related to different biological processes. Early responses involved many cold-stress-responsive genes coding for, among many other things, C-repeat binding factor transcription factors, fatty acid desaturases, wax synthesis, and oligosaccharide metabolism. After long-term exposure to cold, a large proportion of gene down-regulation was found, including photosynthesis and plant growth genes. Up-regulated genes after long-term cold exposure were related to organelle fusion, nucleus organization, and DNA integration, including retrotransposons. © The Author 2014. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

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.

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.

Sustained Perceptual Deficits from Transient Sensory Deprivation

PubMed Central

Sanes, Dan H.

2015-01-01

Sensory pathways display heightened plasticity during development, yet the perceptual consequences of early experience are generally assessed in adulthood. This approach does not allow one to identify transient perceptual changes that may be linked to the central plasticity observed in juvenile animals. Here, we determined whether a brief period of bilateral auditory deprivation affects sound perception in developing and adult gerbils. Animals were reared with bilateral earplugs, either from postnatal day 11 (P11) to postnatal day 23 (P23) (a manipulation previously found to disrupt gerbil cortical properties), or from P23-P35. Fifteen days after earplug removal and restoration of normal thresholds, animals were tested on their ability to detect the presence of amplitude modulation (AM), a temporal cue that supports vocal communication. Animals reared with earplugs from P11-P23 displayed elevated AM detection thresholds, compared with age-matched controls. In contrast, an identical period of earplug rearing at a later age (P23-P35) did not impair auditory perception. Although the AM thresholds of earplug-reared juveniles improved during a week of repeated testing, a subset of juveniles continued to display a perceptual deficit. Furthermore, although the perceptual deficits induced by transient earplug rearing had resolved for most animals by adulthood, a subset of adults displayed impaired performance. Control experiments indicated that earplugging did not disrupt the integrity of the auditory periphery. Together, our results suggest that P11-P23 encompasses a critical period during which sensory deprivation disrupts central mechanisms that support auditory perceptual skills. SIGNIFICANCE STATEMENT Sensory systems are particularly malleable during development. This heightened degree of plasticity is beneficial because it enables the acquisition of complex skills, such as music or language. However, this plasticity comes with a cost: nervous system development

Transient postnatal fluoxetine leads to decreased brain arachidonic acid metabolism and cytochrome P450 4A in adult mice.

PubMed

Ramadan, Epolia; Blanchard, Helene; Cheon, Yewon; Fox, Meredith A; Chang, Lisa; Chen, Mei; Ma, Kaizong; Rapoport, Stanley I; Basselin, Mireille

2014-05-01

Fetal and perinatal exposure to selective serotonin (5-HT) reuptake inhibitors (SSRIs) has been reported to alter childhood behavior, while transient early exposure in rodents is reported to alter their behavior and decrease brain extracellular 5-HT in adulthood. Since 5-HT2A/2C receptor-mediated neurotransmission can involve G-protein coupled activation of cytosolic phospholipase A2 (cPLA2), releasing arachidonic acid (ARA) from synaptic membrane phospholipid, we hypothesized that transient postnatal exposure to fluoxetine would alter brain ARA metabolism in adult mice. Brain ARA incorporation coefficients k* and rates Jin were quantitatively imaged following intravenous [1-(14)C]ARA infusion of unanesthetized adult mice that had been injected daily with fluoxetine (10mg/kg i.p.) or saline during postnatal days P4-P21. Expression of brain ARA metabolic enzymes and other relevant markers also was measured. On neuroimaging, k* and Jin was decreased widely in early fluoxetine- compared to saline-treated adult mice. Of the enzymes measured, cPLA2 activity was unchanged, while Ca(2+)-independent iPLA2 activity was increased. There was a significant 74% reduced protein level of cytochrome P450 (CYP) 4A, which can convert ARA to 20-HETE. Reduced brain ARA metabolism in adult mice transiently exposed to postnatal fluoxetine, and a 74% reduction in CYP4A protein, suggest long-term effects independent of drug presence in brain ARA metabolism, and in CYP4A metabolites. These changes might contribute to reported altered behavior following early SSRI in rodents. Published by Elsevier Ltd.

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.

Transiently Increasing cAMP Levels Selectively in Hippocampal Excitatory Neurons during Sleep Deprivation Prevents Memory Deficits Caused by Sleep Loss

PubMed Central

Bruinenberg, Vibeke M.; Tudor, Jennifer C.; Ferri, Sarah L.; Baumann, Arnd; Meerlo, Peter

2014-01-01

The hippocampus is particularly sensitive to sleep loss. Although previous work has indicated that sleep deprivation impairs hippocampal cAMP signaling, it remains to be determined whether the cognitive deficits associated with sleep deprivation are caused by attenuated cAMP signaling in the hippocampus. Further, it is unclear which cell types are responsible for the memory impairments associated with sleep deprivation. Transgenic approaches lack the spatial resolution to manipulate specific signaling pathways selectively in the hippocampus, while pharmacological strategies are limited in terms of cell-type specificity. Therefore, we used a pharmacogenetic approach based on a virus-mediated expression of a Gαs-coupled Drosophila octopamine receptor selectively in mouse hippocampal excitatory neurons in vivo. With this approach, a systemic injection with the receptor ligand octopamine leads to increased cAMP levels in this specific set of hippocampal neurons. We assessed whether transiently increasing cAMP levels during sleep deprivation prevents memory consolidation deficits associated with sleep loss in an object–location task. Five hours of total sleep deprivation directly following training impaired the formation of object–location memories. Transiently increasing cAMP levels in hippocampal neurons during the course of sleep deprivation prevented these memory consolidation deficits. These findings demonstrate that attenuated cAMP signaling in hippocampal excitatory neurons is a critical component underlying the memory deficits in hippocampus-dependent learning tasks associated with sleep deprivation. PMID:25411499

Transient Ischemic Attack

MedlinePlus Videos and Cool Tools

Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood ... The only difference between a stroke and TIA is that with TIA the blockage is transient (temporary). ...

Transient Go: A Mobile App for Transient Astronomy Outreach

NASA Astrophysics Data System (ADS)

Crichton, D.; Mahabal, A.; Djorgovski, S. G.; Drake, A.; Early, J.; Ivezic, Z.; Jacoby, S.; Kanbur, S.

2016-12-01

Augmented Reality (AR) is set to revolutionize human interaction with the real world as demonstrated by the phenomenal success of `Pokemon Go'. That very technology can be used to rekindle the interest in science at the school level. We are in the process of developing a prototype app based on sky maps that will use AR to introduce different classes of astronomical transients to students as they are discovered i.e. in real-time. This will involve transient streams from surveys such as the Catalina Real-time Transient Survey (CRTS) today and the Large Synoptic Survey Telescope (LSST) in the near future. The transient streams will be combined with archival and latest image cut-outs and other auxiliary data as well as historical and statistical perspectives on each of the transient types being served. Such an app could easily be adapted to work with various NASA missions and NSF projects to enrich the student experience.

Early and late components of EEG delay activity correlate differently with scene working memory performance

PubMed Central

Ng, Kenneth; Reichert, Chelsea P.

2017-01-01

Sustained and elevated activity during the working memory delay period has long been considered the primary neural correlate for maintaining information over short time intervals. This idea has recently been reinterpreted in light of findings generated from multiple neural recording modalities and levels of analysis. To further investigate the sustained or transient nature of activity, the temporal-spectral evolution (TSE) of delay period activity was examined in humans with high density EEG during performance of a Sternberg working memory paradigm with a relatively long six second delay and with novel scenes as stimuli. Multiple analyses were conducted using different trial window durations and different baseline periods for TSE computation. Sensor level analyses revealed transient rather than sustained activity during delay periods. Specifically, the consistent finding among the analyses was that high amplitude activity encompassing the theta range was found early in the first three seconds of the delay period. These increases in activity early in the delay period correlated positively with subsequent ability to distinguish new from old probe scenes. Source level signal estimation implicated a right parietal region of transient early delay activity that correlated positively with working memory ability. This pattern of results adds to recent evidence that transient rather than sustained delay period activity supports visual working memory performance. The findings are discussed in relation to synchronous and desynchronous intra- and inter-regional neural transmission, and choosing an optimal baseline for expressing temporal-spectral delay activity change. PMID:29016657

Transient, Inducible, Placenta-Specific Gene Expression in Mice

PubMed Central

Fan, Xiujun; Petitt, Matthew; Gamboa, Matthew; Huang, Mei; Dhal, Sabita; Druzin, Maurice L.; Wu, Joseph C.

2012-01-01

Molecular understanding of placental functions and pregnancy disorders is limited by the absence of methods for placenta-specific gene manipulation. Although persistent placenta-specific gene expression has been achieved by lentivirus-based gene delivery methods, developmentally and physiologically important placental genes have highly stage-specific functions, requiring controllable, transient expression systems for functional analysis. Here, we describe an inducible, placenta-specific gene expression system that enables high-level, transient transgene expression and monitoring of gene expression by live bioluminescence imaging in mouse placenta at different stages of pregnancy. We used the third generation tetracycline-responsive tranactivator protein Tet-On 3G, with 10- to 100-fold increased sensitivity to doxycycline (Dox) compared with previous versions, enabling unusually sensitive on-off control of gene expression in vivo. Transgenic mice expressing Tet-On 3G were created using a new integrase-based, site-specific approach, yielding high-level transgene expression driven by a ubiquitous promoter. Blastocysts from these mice were transduced with the Tet-On 3G-response element promoter-driving firefly luciferase using lentivirus-mediated placenta-specific gene delivery and transferred into wild-type pseudopregnant recipients for placenta-specific, Dox-inducible gene expression. Systemic Dox administration at various time points during pregnancy led to transient, placenta-specific firefly luciferase expression as early as d 5 of pregnancy in a Dox dose-dependent manner. This system enables, for the first time, reliable pregnancy stage-specific induction of gene expression in the placenta and live monitoring of gene expression during pregnancy. It will be widely applicable to studies of both placental development and pregnancy, and the site-specific Tet-On G3 mouse will be valuable for studies in a broad range of tissues. PMID:23011919

Selected specific rates of reactions of transients from water in aqueous solution. Hydrated electron, supplemental data. [Reactions with transients from water, with inorganic solutes, and with solutes

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

Ross, A.B.

1975-06-01

A compilation of rates of reactions of hydrated electrons with other transients and with organic and inorganic solutes in aqueous solution appeared in NSRDS-NBS 43, and covered the literature up to early 1971. This supplement includes additional rates which have been published through July 1973.

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).

Early Induction of Apple Fruitlet Abscission Is Characterized by an Increase of Both Isoprene Emission and Abscisic Acid Content12[W][OA

PubMed Central

Giulia, Eccher; Alessandro, Botton; Mariano, Dimauro; Andrea, Boschetti; Benedetto, Ruperti; Angelo, Ramina

2013-01-01

Apple (Malus domestica) fruitlet abscission represents an interesting model system to study the early phases of the shedding process, during which major transcriptomic changes and metabolic rearrangements occur within the fruit. In apple, the drop of fruits at different positions within the cluster can be selectively magnified through chemical thinners, such as benzyladenine and metamitron, acting as abscission enhancers. In this study, different abscission potentials were obtained within the apple fruitlet population by means of the above-cited thinners. A metabolomic study was conducted on the volatile organic compounds emitted by abscising fruitlets, allowing for identification of isoprene as an early marker of abscission induction. A strong correlation was also observed between isoprene production and abscisic acid (ABA) levels in the fruit cortex, which were shown to increase in abscising fruitlets with respect to nonabscising ones. Transcriptomic evidence indicated that abscission-related ABA is biologically active, and its increased biosynthesis is associated with the induction of a specific ABA-responsive 9-cis-epoxycarotenoid dioxygenase gene. According to a hypothetical model, ABA may transiently cooperate with other hormones and secondary messengers in the generation of an intrafruit signal leading to the downstream activation of the abscission zone. The shedding process therefore appears to be triggered by multiple interdependent pathways, whose fine regulation, exerted within a very short temporal window by both endogenous and exogenous factors, determines the final destiny of the fruitlets. PMID:23444344

Transient Phenomena in Multiphase and Multicomponent Systems: Research Report

NASA Astrophysics Data System (ADS)

Zur Beurteilung von Stoffen in der Landwirtschaft, Senatskommission

2000-09-01

Due to the reinforced risk and safety-analysis of industrial plants in chemical and energy-engineering there has been increased demand in industry for more information on thermo- and fluiddynamic effects of non-equilibria during strong transients. Therefore, the 'Deutsche Forschungsgemeinschaft' initiated a special research program focusing on the study of transient phenomena in multiphase systems with one or several components. This book describes macroscopic as well as microscopic transient situations. A large part of the book deals with numerical methods for describing transients in two-phase mixtures. New developments in measuring techniques are also presented.

Maternal insulin resistance and transient hyperglycemia impact the metabolic and endocrine phenotypes of offspring

PubMed Central

Kahraman, Sevim; Dirice, Ercument; De Jesus, Dario F.; Hu, Jiang

2014-01-01

Studies in both humans and rodents suggest that maternal diabetes leads to a higher risk of the fetus developing impaired glucose tolerance and obesity during adulthood. However, the impact of hyperinsulinemia in the mother on glucose homeostasis in the offspring has not been fully explored. We aimed to determine the consequences of maternal insulin resistance on offspring metabolism and endocrine pancreas development using the LIRKO mouse model, which exhibits sustained hyperinsulinemia and transient increase in blood glucose concentrations during pregnancy. We examined control offspring born to either LIRKO or control mothers on embryonic days 13.5, 15.5, and 17.5 and postpartum days 0, 4, and 10. Control offspring born to LIRKO mothers displayed low birth weights and subsequently rapidly gained weight, and their blood glucose and plasma insulin concentrations were higher than offspring born to control mothers in early postnatal life. In addition, concentrations of plasma leptin, glucagon, and active GLP-1 were higher in control pups from LIRKO mothers. Analyses of the endocrine pancreas revealed significantly reduced β-cell area in control offspring of LIRKO mothers shortly after birth. β-Cell proliferation and total islet number were also lower in control offspring of LIRKO mothers during early postnatal days. Together, these data indicate that maternal hyperinsulinemia and the transient hyperglycemia impair endocrine pancreas development in the control offspring and induce multiple metabolic alterations in early postnatal life. The relatively smaller β-cell mass/area and β-cell proliferation in these control offspring suggest cell-autonomous epigenetic mechanisms in the regulation of islet growth and development. PMID:25249504

On a method computing transient wave propagation in ionospheric regions

NASA Technical Reports Server (NTRS)

Gray, K. G.; Bowhill, S. A.

1978-01-01

A consequence of an exoatmospheric nuclear burst is an electromagnetic pulse (EMP) radiated from it. In a region far enough away from the burst, where nonlinear effects can be ignored, the EMP can be represented by a large-amplitude narrow-time-width plane-wave pulse. If the ionosphere intervenes the origin and destination of the EMP, frequency dispersion can cause significant changes in the original pulse upon reception. A method of computing these dispersive effects of transient wave propagation is summarized. The method described is different from the standard transform techniques and provides physical insight into the transient wave process. The method, although exact, can be used in approximating the early-time transient response of an ionospheric region by a simple integration with only explicit knowledge of the electron density, electron collision frequency, and electron gyrofrequency required. As an illustration of the method, it is applied to a simple example and contrasted with the corresponding transform solution.

Transient pressure analysis of a volume fracturing well in fractured tight oil reservoirs

NASA Astrophysics Data System (ADS)

Lu, Cheng; Wang, Jiahang; Zhang, Cong; Cheng, Minhua; Wang, Xiaodong; Dong, Wenxiu; Zhou, Yingfang

2017-12-01

This paper presents a semi-analytical model to simulate transient pressure curves for a vertical well with a reconstructed fracture network in fractured tight oil reservoirs. In the proposed model, the reservoir is a composite system and contains two regions. The inner region is described as a formation with a finite conductivity hydraulic fracture network and the flow in the fracture is assumed to be linear, while the outer region is modeled using the classical Warren-Root model where radial flow is applied. The transient pressure curves of a vertical well in the proposed reservoir model are calculated semi-analytically using the Laplace transform and Stehfest numerical inversion. As shown in the type curves, the flow is divided into several regimes: (a) linear flow in artificial main fractures; (b) coupled boundary flow; (c) early linear flow in a fractured formation; (d) mid radial flow in the semi-fractures of the formation; (e) mid radial flow or pseudo steady flow; (f) mid cross-flow; (g) closed boundary flow. Based on our newly proposed model, the effects of some sensitive parameters, such as elastic storativity ratio, cross-flow coefficient, fracture conductivity and skin factor, on the type curves were also analyzed extensively. The simulated type curves show that for a vertical fractured well in a tight reservoir, the elastic storativity ratios and crossflow coefficients affect the time and the degree of crossflow respectively. The pressure loss increases with an increase in the fracture conductivity. To a certain extent, the effect of the fracture conductivity is more obvious than that of the half length of the fracture on improving the production effect. With an increase in the wellbore storage coefficient, the fluid compressibility is so large that it might cover the early stage fracturing characteristics. Linear or bilinear flow may not be recognized, and the pressure and pressure derivative gradually shift to the right. With an increase in the skin

Transiently increasing cAMP levels selectively in hippocampal excitatory neurons during sleep deprivation prevents memory deficits caused by sleep loss.

PubMed

Havekes, Robbert; Bruinenberg, Vibeke M; Tudor, Jennifer C; Ferri, Sarah L; Baumann, Arnd; Meerlo, Peter; Abel, Ted

2014-11-19

The hippocampus is particularly sensitive to sleep loss. Although previous work has indicated that sleep deprivation impairs hippocampal cAMP signaling, it remains to be determined whether the cognitive deficits associated with sleep deprivation are caused by attenuated cAMP signaling in the hippocampus. Further, it is unclear which cell types are responsible for the memory impairments associated with sleep deprivation. Transgenic approaches lack the spatial resolution to manipulate specific signaling pathways selectively in the hippocampus, while pharmacological strategies are limited in terms of cell-type specificity. Therefore, we used a pharmacogenetic approach based on a virus-mediated expression of a Gαs-coupled Drosophila octopamine receptor selectively in mouse hippocampal excitatory neurons in vivo. With this approach, a systemic injection with the receptor ligand octopamine leads to increased cAMP levels in this specific set of hippocampal neurons. We assessed whether transiently increasing cAMP levels during sleep deprivation prevents memory consolidation deficits associated with sleep loss in an object-location task. Five hours of total sleep deprivation directly following training impaired the formation of object-location memories. Transiently increasing cAMP levels in hippocampal neurons during the course of sleep deprivation prevented these memory consolidation deficits. These findings demonstrate that attenuated cAMP signaling in hippocampal excitatory neurons is a critical component underlying the memory deficits in hippocampus-dependent learning tasks associated with sleep deprivation. Copyright © 2014 the authors 0270-6474/14/3415715-07$15.00/0.

Does Raising the Early Retirement Age Increase Employment of Older Workers?

PubMed

Staubli, Stefan; Zweimüller, Josef

2013-12-01

Two pension reforms in Austria increased the early retirement age (ERA) from 60 to 62 for men and from 55 to 58.25 for women. We find that raising the ERA increased employment by 9.75 percentage points among affected men and by 11 percentage points among affected women. The reforms had large spillover effects on the unemployment insurance program but negligible effects on disability insurance claims. Specifically, unemployment increased by 12.5 percentage points among men and by 11.8 percentage points among women. The employment response was largest among high-wage and healthy workers, while low-wage and less healthy workers either continued to retire early via disability benefits or bridged the gap to the ERA via unemployment benefits. Taking spillover effects and additional tax revenues into account, we find that for a typical birth-year cohort a one year increase in the ERA resulted in a reduction of net government expenditures of 107 million euros for men and of 122 million euros for women.

Internet-based information-seeking behavior for transient ischemic attack.

PubMed

Abedi, Vida; Mbaye, Marieme; Tsivgoulis, Georgios; Male, Shailesh; Goyal, Nitin; Alexandrov, Andrei V; Zand, Ramin

2015-12-01

In recent years, Internet became an increasingly important tool for accessing health information and is being used more frequently to promote public health. To use Google search data to explore information seeking behavior for transient ischemic attack. We selected two groups of keywords related to transient ischemic attack: 'Transient Ischemic Attack' and 'Mini Stroke'. We obtained all available online search data performed in the United States from the Google search engine for a 10-year span--January 2004 to December 2013. The monthly and daily search data for the selected keywords were analyzed--using moving average--to explore the trends, peaks, and declining effects. There were three significant concurrent peaks in the Google search data for the selected keywords. Each peak was directly associated with media coverage and news headlines related to the incident of transient ischemic attack in a public figure. Following each event, it took three- to seven-days for the search trend to return to its respective average value. Furthermore, the trend was steady for 'Transient Ischemic Attack'; however, the search interest for the keyword 'Mini Stroke' shows a steady increase. The overall search interest for the selected keywords was significantly higher in the southeastern United States. Our study shows that changes in online search behavior can be associated with media coverage of key events (in our case transient ischemic attack) in public figures. These findings suggest that multimedia health promotion campaigns might be more effective, if increased promptly after similar media coverage. © 2015 World Stroke Organization.

Early life stress confers lifelong stress susceptibility in mice via ventral tegmental area OTX2.

PubMed

Peña, Catherine J; Kronman, Hope G; Walker, Deena M; Cates, Hannah M; Bagot, Rosemary C; Purushothaman, Immanuel; Issler, Orna; Loh, Yong-Hwee Eddie; Leong, Tin; Kiraly, Drew D; Goodman, Emma; Neve, Rachael L; Shen, Li; Nestler, Eric J

2017-06-16

Early life stress increases risk for depression. Here we establish a "two-hit" stress model in mice wherein stress at a specific postnatal period increases susceptibility to adult social defeat stress and causes long-lasting transcriptional alterations that prime the ventral tegmental area (VTA)-a brain reward region-to be in a depression-like state. We identify a role for the developmental transcription factor orthodenticle homeobox 2 ( Otx2 ) as an upstream mediator of these enduring effects. Transient juvenile-but not adult-knockdown of Otx2 in VTA mimics early life stress by increasing stress susceptibility, whereas its overexpression reverses the effects of early life stress. This work establishes a mechanism by which early life stress encodes lifelong susceptibility to stress via long-lasting transcriptional programming in VTA mediated by Otx2 . Copyright © 2017, American Association for the Advancement of Science.

Velocity and size of droplets in dense region of diesel fuel spray on transient needle opening condition

NASA Astrophysics Data System (ADS)

Ueki, Hironobu; Ishida, Masahiro; Sakaguchi, Daisaku

2005-06-01

In order to investigate the effect of transient needle opening on early stage of spray behavior, simultaneous measurements of velocity and size of droplet were conducted by a newly developed laser 2-focus velocimeter (L2F). The micro-scale probe of the L2F was consisted of two foci with a distance of 36 µm. The tested nozzle had a single hole with a diameter of 0.2 mm. The measurements of injection pressure, needle lift, and crank angle were synchronized with the spray measurement by the L2F at the position 10 mm downstream from the nozzle exit. It has been clearly shown that the velocity and size of droplet increase with needle valve opening and that the probability density distribution of droplet size can be fitted to the Nukiyama-Tanasawa distribution under the transient needle opening condition.

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

Inhomogeneous Forcing and Transient Climate Sensitivity

NASA Technical Reports Server (NTRS)

Shindell, Drew T.

2014-01-01

Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10-15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (less than 1.3 C) is very unlikely.

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.

Analytical Assessment for Transient Stability Under Stochastic Continuous Disturbances

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

Ju, Ping; Li, Hongyu; Gan, Chun

Here, with the growing integration of renewable power generation, plug-in electric vehicles, and other sources of uncertainty, increasing stochastic continuous disturbances are brought to power systems. The impact of stochastic continuous disturbances on power system transient stability attracts significant attention. To address this problem, this paper proposes an analytical assessment method for transient stability of multi-machine power systems under stochastic continuous disturbances. In the proposed method, a probability measure of transient stability is presented and analytically solved by stochastic averaging. Compared with the conventional method (Monte Carlo simulation), the proposed method is many orders of magnitude faster, which makes itmore » very attractive in practice when many plans for transient stability must be compared or when transient stability must be analyzed quickly. Also, it is found that the evolution of system energy over time is almost a simple diffusion process by the proposed method, which explains the impact mechanism of stochastic continuous disturbances on transient stability in theory.« less

RISPERIDONE VERSUS HALOPERIDOL IN ACUTE AND TRANSIENT PSYCHOTIC DISORDER

PubMed Central

Chaudhuri, Bijoy Pratim; Bhagabati, Dipesh; Medhi, Dipanjali

2000-01-01

The mechanism of action of a relatively new antipsychotic drug-Risperidone differs from conventional antipsychotics like Haloperidol. We compared low dosages of Risperidone with near equivalent dosages of Haloperidol in first episode drug naive Acute and Transient Psychotic disorder. A single blind randomised four-week study protocol was employed. Highly significant and comparable efficacy as assessed by Brief Psychiatric Rating Scale and Global Assessment of Functioning Scale was seen at the end of the Study protocol in both the groups. Risperidone had significantly, an early onset of action on some of the positive as well as negative symptoms with less incidence of Extrapyramidal Symptoms in comparison to Haloperidol. We conclude that Risperidone may represent a potential useful first line agent in the treatment of Acute and Transient Psychotic Disorder. PMID:21407958

Metabolic studies of transient tyrosinemia in premature infants

NASA Technical Reports Server (NTRS)

Fernbach, S. A.; Summons, R. E.; Pereira, W. E.; Duffield, A. M.

1975-01-01

The recently developed technique of gas chromatography-mass spectrometry supported by computer has considerably improved the analysis of physiologic fluids. This study attempted to demonstrate the value of this system in the investigation of metabolite patterns in urine in two metabolic problems of prematurity, transient tyrosinemia and late metabolic acidosis. Serial 24-hr urine specimens were analyzed in 9 infants. Transient tyrosinemia, characterized by 5- 10-fold increases over basal excretion of tyrosine, p-hydroxyphenyllactate, and p-hydroxyphenylpyruvate in urine, was noted in five of the infants. Late metabolic acidosis was seen in four infants, but bore no relation to transient tyrosinemia.

Swelling and gas release in oxide fuels during fast temperature transients

NASA Astrophysics Data System (ADS)

Dollins, C. C.; Jursich, M.

1982-05-01

A previously reported intergranular swelling and gas release model for oxide fuels has been modified to predict fission gas behavior during fast temperature transients. Under steady state or slowly varying conditions it has been assumed in the previous model that the pressure caused by the fission gas within the gas bubbles is in equilibrium with the surface tension of the bubbles. During a fast transient, however, net vacancy migration to the bubbles may be insufficient to maintain this equilibrium. In order to ascertain the net vacancy flow, it is necessary to model the point defect behavior in the fuel. Knowing the net flow of vacancies to the bubble and the bubble size, the bubble diffusivity can be determined and the long range migration of the gas out of the fuel can be calculated. The model has also been modified to allow release of all the gas on the grain boundaries during a fast temperature transient. The gas release predicted by the revised model shows good agreement to fast transient gas release data from an EBR-II TREAT H-3 (Transient Reactor Test Facility) test. Agreement has also been obtained between predictions using the model and gas release data obtained by Argonne National Laboratory from out-of-reactor transient heating experiments on irradiated UO 2. It was found necessary to increase the gas bubble diffusivity used in the model by a factor of thirty during the transient to provide agreement between calculations and measurements. Other workers have also found that such an increase is necessary for agreement and attribute the increased diffusivity to yielding at the bubble surface due to the increased pressure.

Advanced Instrumentation for Transient Reactor Testing

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

Corradini, Michael L.; Anderson, Mark; Imel, George

Transient testing involves placing fuel or material into the core of specialized materials test reactors that are capable of simulating a range of design basis accidents, including reactivity insertion accidents, that require the reactor produce short bursts of intense highpower neutron flux and gamma radiation. Testing fuel behavior in a prototypic neutron environment under high-power, accident-simulation conditions is a key step in licensing nuclear fuels for use in existing and future nuclear power plants. Transient testing of nuclear fuels is needed to develop and prove the safety basis for advanced reactors and fuels. In addition, modern fuel development and designmore » increasingly relies on modeling and simulation efforts that must be informed and validated using specially designed material performance separate effects studies. These studies will require experimental facilities that are able to support variable scale, highly instrumented tests providing data that have appropriate spatial and temporal resolution. Finally, there are efforts now underway to develop advanced light water reactor (LWR) fuels with enhanced performance and accident tolerance. These advanced reactor designs will also require new fuel types. These new fuels need to be tested in a controlled environment in order to learn how they respond to accident conditions. For these applications, transient reactor testing is needed to help design fuels with improved performance. In order to maximize the value of transient testing, there is a need for in-situ transient realtime imaging technology (e.g., the neutron detection and imaging system like the hodoscope) to see fuel motion during rapid transient excursions with a higher degree of spatial and temporal resolution and accuracy. There also exists a need for new small, compact local sensors and instrumentation that are capable of collecting data during transients (e.g., local displacements, temperatures, thermal conductivity, neutron flux

Increased proximal acid reflux is associated with early readmission following lung transplantation.

PubMed

Lo, W-K; Goldberg, H J; Burakoff, R; Feldman, N; Chan, W W

2016-02-01

Gastroesophageal reflux disease has been associated with poor outcomes following lung transplantation. However, the association between pretransplant reflux and post-transplant readmission, an indicator of early clinical outcome, has not been previously assessed. This was a retrospective cohort study of lung transplant recipients undergoing pretransplant multichannel intraluminal impedance and pH (MII-pH) study off acid suppression at a tertiary care center since 2007. Subjects with pretransplant fundoplication were excluded. Time to readmission was defined as duration from post-transplant discharge to next hospital admission for any reason. Subgroup analysis was performed to exclude elective readmissions. Time-to-event analysis was performed using Cox proportional hazards model, with appropriate censoring. Forty-three subjects (60% men, mean age: 57, median follow-up: 1.7 years) met inclusion criteria for the study. Patient demographics and pretransplant cardiopulmonary function were similar between readmission cohorts. Time to all-cause readmission was associated with increased distal acid episodes (HR: 3.15, p = 0.04) and proximal acid episodes (HR: 3.61, p = 0.008) on impedance, increased acid exposure on pH (HR: 2.22, p = 0.04), and elevated Demeester score (HR: 2.26, p = 0.03). When elective readmissions were excluded, early readmission remained significantly associated with increased proximal acid reflux episodes (HR: 2.49, p = 0.04). All findings were confirmed on Kaplan-Meier analysis. Elevated proximal acid reflux on pretransplant MII-pH testing was associated with early readmission following lung transplantation, even after excluding elective readmissions. Exposure to severe acid reflux has measurable effects on early postoperative outcomes such as readmission, and aggressive early antireflux therapy should be considered. © 2015 John Wiley & Sons Ltd.

Does Raising the Early Retirement Age Increase Employment of Older Workers?*

PubMed Central

Staubli, Stefan; Zweimüller, Josef

2013-01-01

Two pension reforms in Austria increased the early retirement age (ERA) from 60 to 62 for men and from 55 to 58.25 for women. We find that raising the ERA increased employment by 9.75 percentage points among affected men and by 11 percentage points among affected women. The reforms had large spillover effects on the unemployment insurance program but negligible effects on disability insurance claims. Specifically, unemployment increased by 12.5 percentage points among men and by 11.8 percentage points among women. The employment response was largest among high-wage and healthy workers, while low-wage and less healthy workers either continued to retire early via disability benefits or bridged the gap to the ERA via unemployment benefits. Taking spillover effects and additional tax revenues into account, we find that for a typical birth-year cohort a one year increase in the ERA resulted in a reduction of net government expenditures of 107 million euros for men and of 122 million euros for women. PMID:24319299

Active Early: one-year policy intervention to increase physical activity among early care and education programs in Wisconsin.

PubMed

LaRowe, Tara L; Tomayko, Emily J; Meinen, Amy M; Hoiting, Jill; Saxler, Courtney; Cullen, Bridget

2016-07-20

Early childcare and education (ECE) is a prime setting for obesity prevention and the establishment of healthy behaviors. The objective of this quasi-experimental study was to examine the efficacy of the Active Early guide, which includes evidenced-based approaches, provider resources, and training, to improve physical activity opportunities through structured (i.e. teacher-led) activity and environmental changes thereby increasing physical activity among children, ages 2-5 years, in the ECE setting. Twenty ECE programs in Wisconsin, 7 family and 13 group, were included. An 80-page guide, Active Early, was developed by experts and statewide partners in the fields of ECE, public health, and physical activity and was revised by ECE providers prior to implementation. Over 12 months, ECE programs received on-site training and technical assistance to implement the strategies and resources provided in the Active Early guide. Main outcome measures included observed minutes of teacher-led physical activity, physical activity environment measured by the Environment and Policy Assessment and Observation (EPAO) instrument, and child physical activity levels via accelerometry. All measures were collected at baseline, 6 months, and 12 months and were analyzed for changes over time. Observed teacher-led physical activity significantly increased from 30.9 ± 22.7 min at baseline to 82.3 ± 41.3 min at 12 months. The change in percent time children spent in sedentary activity decreased significantly after 12 months (-4.4 ± 14.2 % time, -29.2 ± 2.6 min, p < 0.02). Additionally, as teacher led-activity increased, percent time children were sedentary decreased (r = -0.37, p < 0.05) and percent time spent in light physical activity increased (r = 0.35, p < 0.05). Among all ECE programs, the physical activity environment improved significantly as indicated by multiple sub-scales of the EPAO; scores showing the greatest increases were the

Ultrafast laser processing of copper: A comparative study of experimental and simulated transient optical properties

NASA Astrophysics Data System (ADS)

Winter, Jan; Rapp, Stephan; Schmidt, Michael; Huber, Heinz P.

2017-09-01

In this paper, we present ultrafast measurements of the complex refractive index for copper up to a time delay of 20 ps with an accuracy <1% at laser fluences in the vicinity of the ablation threshold. The measured refractive index n and extinction coefficient k are supported by a simulation including the two-temperature model with an accurate description of thermal and optical properties and a thermomechanical model. Comparison of the measured time resolved optical properties with results of the simulation reveals underlying physical mechanisms in three distinct time delay regimes. It is found that in the early stage (-5 ps to 0 ps) the thermally excited d-band electrons make a major contribution to the laser pulse absorption and create a steep increase in transient optical properties n and k. In the second time regime (0-10 ps) the material expansion influences the plasma frequency, which is also reflected in the transient extinction coefficient. In contrast, the refractive index n follows the total collision frequency. Additionally, the electron-ion thermalization time can be attributed to a minimum of the extinction coefficient at ∼10 ps. In the third time regime (10-20 ps) the transient extinction coefficient k indicates the surface cooling-down process.

Transient Thermoelectric Solution Employing Green's Functions

NASA Technical Reports Server (NTRS)

Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

2014-01-01

The study works to formulate convenient solutions to the problem of a thermoelectric couple operating under a time varying condition. Transient operation of a thermoelectric will become increasingly common as thermoelectric technology permits applications in an increasing number of uses. A number of terrestrial applications, in contrast to steady-state space applications, can subject devices to time varying conditions. For instance thermoelectrics can be exposed to transient conditions in the automotive industry depending on engine system dynamics along with factors like driving style. In an effort to generalize the thermoelectric solution a Greens function method is used, so that arbitrary time varying boundary and initial conditions may be applied to the system without reformulation. The solution demonstrates that in thermoelectric applications of a transient nature additional factors must be taken into account and optimized. For instance, the materials specific heat and density become critical parameters in addition to the thermal mass of a heat sink or the details of the thermal profile, such as oscillating frequency. The calculations can yield the optimum operating conditions to maximize power output andor efficiency for a given type of device.

Constraints on Transient Viscoelastic Rheology of the Asthenosphere From Seasonal Deformation

NASA Astrophysics Data System (ADS)

Chanard, Kristel; Fleitout, Luce; Calais, Eric; Barbot, Sylvain; Avouac, Jean-Philippe

2018-03-01

We discuss the constraints on short-term asthenospheric viscosity provided by seasonal deformation of the Earth. We use data from 195 globally distributed continuous Global Navigation Satellite System stations. Surface loading is derived from the Gravity Recovery and Climate Experiment and used as an input to predict geodetic displacements. We compute Green's functions for surface displacements for a purely elastic spherical reference Earth model and for viscoelastic Earth models. We show that a range of transient viscoelastic rheologies derived to explain the early phase of postseismic deformation may induce a detectable effect on the phase and amplitude of horizontal displacements induced by seasonal loading at long wavelengths (1,300-4,000 km). By comparing predicted and observed seasonal horizontal motion, we conclude that transient asthenospheric viscosity cannot be lower than 5 × 1017 Pa.s, suggesting that low values of transient asthenospheric viscosities reported in some postseismic studies cannot hold for the seasonal deformation global average.

Reduction of adenovirus E1A mRNA by RNAi results in enhanced recombinant protein expression in transiently transfected HEK293 cells.

PubMed

Hacker, David L; Bertschinger, Martin; Baldi, Lucia; Wurm, Florian M

2004-10-27

Human embryonic kidney 293 (HEK293) cells, a widely used host for large-scale transient expression of recombinant proteins, are transformed with the adenovirus E1A and E1B genes. Because the E1A proteins function as transcriptional activators or repressors, they may have a positive or negative effect on transient transgene expression in this cell line. Suspension cultures of HEK293 EBNA (HEK293E) cells were co-transfected with a reporter plasmid expressing the GFP gene and a plasmid expressing a short hairpin RNA (shRNA) targeting the E1A mRNAs for degradation by RNA interference (RNAi). The presence of the shRNA in HEK293E cells reduced the steady state level of E1A mRNA up to 75% and increased transient GFP expression from either the elongation factor-1alpha (EF-1alpha) promoter or the human cytomegalovirus (HCMV) immediate early promoter up to twofold. E1A mRNA depletion also resulted in a twofold increase in transient expression of a recombinant IgG in both small- and large-scale suspension cultures when the IgG light and heavy chain genes were controlled by the EF-1alpha promoter. Finally, transient IgG expression was enhanced 2.5-fold when the anti-E1A shRNA was expressed from the same vector as the IgG light chain gene. These results demonstrated that E1A has a negative effect on transient gene expression in HEK293E cells, and they established that RNAi can be used to enhance recombinant protein expression in mammalian cells.

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

PSH Transient Simulation Modeling

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

Muljadi, Eduard

PSH Transient Simulation Modeling presentation from the WPTO FY14 - FY16 Peer Review. Transient effects are an important consideration when designing a PSH system, yet numerical techniques for hydraulic transient analysis still need improvements for adjustable-speed (AS) reversible pump-turbine applications.

Studies of Transient Meteor Activity

NASA Technical Reports Server (NTRS)

Jenniskens, Peter M. M.

2002-01-01

Meteoroids bombard Earth's atmosphere daily, but occasionally meteor rates increase to unusual high levels when Earth crosses the relatively fresh ejecta of comets. These transient events in meteor activity provide clues about the whereabouts of Earth-threatening long-period comets, the mechanisms of large-grain dust ejection from comets, and the particle composition and size distribution of the cometary ejecta. Observations of these transient events provide important insight in natural processes that determine the large grain dust environment of comets, in natural phenomena that were prevalent during the time of the origin of life, and in processes that determine the hazard of civilizations to large impacts and of man-made satellites to the periodic blizzard of small meteoroids. In this proposal, three tasks form a coherent program aimed at elucidating various aspects of meteor outbursts, with special reference to planetary astronomy and astrobiology. Task 1 was a ground-based effort to observe periods of transient meteor activity. This includes: (1) stereoscopic imaging of meteors during transient meteor events for measurements of particle size distribution, meteoroid orbital dispersions and fluxes; and (2) technical support for Global-MS-Net, a network of amateur-operated automatic counting stations for meteor reflections from commercial VHF radio and TV broadcasting stations, keeping a 24h vigil on the level of meteor activity for the detection of new meteor streams. Task 2 consisted of ground-based and satellite born spectroscopic observations of meteors and meteor trains during transient meteor events for measurements of elemental composition, the presence of organic matter in the meteoroids, and products generated by the interaction of the meteoroid with the atmosphere. Task 3 was an airborne effort to explore the 2000 Leonid meteor outbursts, which are anticipated to be the most significant of transient meteor activity events in the remainder of the

Early changes in microbial colonization selectively modulate intestinal enzymes, but not inducible heat shock proteins in young adult Swine.

PubMed

Arnal, Marie-Edith; Zhang, Jing; Messori, Stefano; Bosi, Paolo; Smidt, Hauke; Lallès, Jean-Paul

2014-01-01

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but also

Early Changes in Microbial Colonization Selectively Modulate Intestinal Enzymes, but Not Inducible Heat Shock Proteins in Young Adult Swine

PubMed Central

Arnal, Marie-Edith; Zhang, Jing; Messori, Stefano; Bosi, Paolo; Smidt, Hauke; Lallès, Jean-Paul

2014-01-01

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but

A telephone hotline for transient ischaemic attack and stroke: prospective audit of a model to improve rapid access to specialist stroke care.

PubMed

Kerr, Enda; Arulraj, Nolan; Scott, Maggie; McDowall, Mike; van Dijke, Margrethe; Keir, Sarah; Sandercock, Peter; Dennis, Martin

2010-07-02

Patients with transient ischaemic attack or stroke benefit from early diagnosis, specialist assessment, and treatment with thrombolysis, and from stroke unit care and secondary prevention. The challenge with such patients is to minimise delays and ensure that treatment is appropriate, and to provide this care with the available resources. An ongoing prospective audit of a transient ischaemic attack and stroke clinic (1 January 2005 to 30 September 2009), as part of the Scottish Stroke Care Audit, and a three month targeted audit of immediate telephone access to a specialist stroke consultant (1 February 2009 to 30 April 2009). Stroke and transient ischaemic attack services in Lothian, a region of Scotland with a population of 810,000. Delays to assessment at a rapid access transient ischaemic attack and stroke clinic; delays to appropriate treatment. In February 2007 we introduced a 24 hours a day, seven days a week hotline to a consultant, who provided immediate advice on diagnosis, investigation, and emergency treatment for patients with transient ischaemic attack or stroke, and suggested the most appropriate care pathway, which might include an early appointment in a transient ischaemic attack and stroke clinic. The introduction of the hotline was associated with an immediate and sustained reduction in delays to assessment (from 13 to three days) and treatment. The proportion of participants taking statins at the time of visiting the clinic increased from 40% before the introduction of the hotline to 60% after the hotline was in place. Also, the hotline contributed to a reduction in the delay from last event to carotid surgery, from 58 days to 21.5 days. A total of 376 calls were received during the three month audit. Of the 273 (88%) referrers who responded to our questionnaire, 257 (94%) were very satisfied with the advice given over the hotline. Although associated with some disruption to the activities of the consultants, a 24 hours a day, seven days a week

Summary of the CTS Transient Event Counter data after one year of operation. [Communication Technology Satellite

NASA Technical Reports Server (NTRS)

Stevens, N. J.; Klinect, V. W.; Gore, J. V.

1977-01-01

The environmental charging of satellite surfaces during geomagnetic substorms is the apparent cause of a significant number of anomalous events occurring on geosynchronous satellites since the early 1970's. Electromagnetic pulses produced in connection with the differential charging of insulators can couple into the spacecraft harness and cause electronic switching anomalies. An investigation conducted to determine the response of the spacecraft surfaces to substorm particle fluxes makes use of a harness transient detector. The harness transient detector, called the Transient Event Counter (TEC) was built and integrated into the Canadian-American Communications Technology Satellite (CTS). A description of the TEC and its operational characteristics is given and the obtained data are discussed. The data show that the satellite surfaces appear to be charged to the point that discharges occur and that the discharge-induced transients couple into the wire harnesses.

[Early alcohol initiation and increased adult alcohol consumption: cause or indicator?].

PubMed

Geels, L M; Vink, J M; van Beek, J H D A; Willemsen, G; Bartels, M; Boomsma, D I

2013-01-01

Early alcohol initiation is strongly associated with increased alcohol consumption and alcohol abuse/dependence in adulthood. The mechanisms that underlie this association are unclear. To examine whether there is a causal link between early alcohol initiation and later alcohol consumption. Survey data were collected from twin pairs (age range 18-80) included in the Netherlands Twin Register (NTR). A discordant twin design was used to examine the origin of the link between early alcohol initiation and adult alcohol consumption. Within monozygotic pairs (82-143 pairs), twins who started drinking early were compared to their brother/sister who started drinking later, on frequency of alcohol use, weekly alcohol consumption, number of alcohol intoxications, excessive drinking, alcohol abuse/-dependence, and hazardous drinking. By drawing comparisons within monozygotic pairs, we were able to control for the effects of genes/shared environment. Additional analyses examined the effects of age, sex, and in-/exclusion of lifelong abstainers. Within monozygotic twin pairs, the twin who had started drinking early did not differ significantly from his/her brother/sister with respect to future alcohol consumption. Results were independent of age, sex, and in-/exclusion of lifelong abstainers. Early alcohol initiation did not have significant causal effects on subsequent alcohol consumption in adulthood and may be an indicator of a predisposition for alcohol consumption. Campaigns aimed at raising the minimum age for alcohol initiation will possibly have only a limited effect on adult alcohol consumption.

Risk of Wheezing Attacks in Infants With Transient Tachypnea Newborns.

PubMed

Golshantafti, Mohammad; Yavari, Tahereh; Afrand, Mohammadhosain

2016-02-01

The most common reason of respiratory distress in the newborn is transient tachypnea of the newborn (TTN). There are some reports saying that TTN is associated with increased frequencies of wheezing attacks. The aims of this study were to determine the risk factors associated with TTN and to determine the association between TTN and the development of wheezing syndromes in early life. In a historical cohort study, we recorded the characteristics of 70 infants born at the Shohadaye Kargar Hospital in Yazd between March 2005 and March 2009 and who were hospitalized because of TTN in the neonatal intensive-care unit. We called their parents at least four years after the infants were discharged from the hospital and asked about any wheezing attacks. Seventy other infants with no health problems during the newborn period were included in the study as the control group. The rate of wheezing attacks in newborns with TTN was more than patients with no TTN diagnosis (P = 0.014). TTN was found to be an independent risk factor for later wheezing attacks (relative risk [RR] = 2.8). The most obvious finding of this study was that TTN was an independent risk factor for wheezing attacks. So long-term medical care is suggested for these patients who may be at risk, because TTN may not be as transient as has been previously thought.

DDOTI: the Deca-Degree Optical Transient Imager

NASA Technical Reports Server (NTRS)

Watson, Alan M.; Lee, William H.; Troja, Eleonora; Roman-Zuniga, Carlos G.; Butler, Nathaniel R.; Kutyrev, Alexander S.; Gehrels, Neil A.; Angeles, Fernando; Basa, Stephane; Blanc, Pierre-Eric;

Discovery of a new X-ray transient in the globular cluster Liller 1

NASA Astrophysics Data System (ADS)

Homan, Jeroen; van den Berg, Maureen; Heinke, Craig; Pooley, David; Degenaar, Nathalie; van den Eijnden, Jakob; Bahramian, Arash; Gendreau, Keith; Arzoumanian, Zaven

2018-05-01

We report on the discovery of a new X-ray transient in the globular cluster Liller 1 with Chandra. Swift/XRT monitoring observations of the globular cluster Liller 1 in early April 2018 revealed low-level activity (around 0.1 ct/s) in the core of the cluster.

Transient triggering of near and distant earthquakes

USGS Publications Warehouse

Gomberg, J.; Blanpied, M.L.; Beeler, N.M.

1997-01-01

We demonstrate qualitatively that frictional instability theory provides a context for understanding how earthquakes may be triggered by transient loads associated with seismic waves from near and distance earthquakes. We assume that earthquake triggering is a stick-slip process and test two hypotheses about the effect of transients on the timing of instabilities using a simple spring-slider model and a rate- and state-dependent friction constitutive law. A critical triggering threshold is implicit in such a model formulation. Our first hypothesis is that transient loads lead to clock advances; i.e., transients hasten the time of earthquakes that would have happened eventually due to constant background loading alone. Modeling results demonstrate that transient loads do lead to clock advances and that the triggered instabilities may occur after the transient has ceased (i.e., triggering may be delayed). These simple "clock-advance" models predict complex relationships between the triggering delay, the clock advance, and the transient characteristics. The triggering delay and the degree of clock advance both depend nonlinearly on when in the earthquake cycle the transient load is applied. This implies that the stress required to bring about failure does not depend linearly on loading time, even when the fault is loaded at a constant rate. The timing of instability also depends nonlinearly on the transient loading rate, faster rates more rapidly hastening instability. This implies that higher-frequency and/or longer-duration seismic waves should increase the amount of clock advance. These modeling results and simple calculations suggest that near (tens of kilometers) small/moderate earthquakes and remote (thousands of kilometers) earthquakes with magnitudes 2 to 3 units larger may be equally effective at triggering seismicity. Our second hypothesis is that some triggered seismicity represents earthquakes that would not have happened without the transient load (i

Moderate alcohol exposure during early brain development increases stimulus-response habits in adulthood.

PubMed

Parker, Matthew O; Evans, Alexandra M-D; Brock, Alistair J; Combe, Fraser J; Teh, Muy-Teck; Brennan, Caroline H

2016-01-01

Exposure to alcohol during early central nervous system development has been shown variously to affect aspects of physiological and behavioural development. In extreme cases, this can extend to craniofacial defects, severe developmental delay and mental retardation. At more moderate levels, subtle differences in brain morphology and behaviour have been observed. One clear effect of developmental alcohol exposure is an increase in the propensity to develop alcoholism and other addictions. The mechanisms by which this occurs, however, are not currently understood. In this study, we tested the hypothesis that adult zebrafish chronically exposed to moderate levels of ethanol during early brain ontogenesis would show an increase in conditioned place preference for alcohol and an increased propensity towards habit formation, a key component of drug addiction in humans. We found support for both of these hypotheses and found that the exposed fish had changes in mRNA expression patterns for dopamine receptor, nicotinic acetylcholine receptor and μ-opioid receptor encoding genes. Collectively, these data show an explicit link between the increased proclivity for addiction and addiction-related behaviour following exposure to ethanol during early brain development and alterations in the neural circuits underlying habit learning. © 2014 Society for the Study of Addiction.

Feasibility of a transient elastography technique for in vitro arterial elasticity assessment.

PubMed

Brum, J; Balay, G; Bia, D; Armentano, R L; Negreira, C

2010-01-01

The early detection of biomechanical modifications in the arterial wall could be used as a predictor factor for various diseases, for example hypertension or atherosclerosis. In this work a transient elastography technique is used for the in vitro evaluation of the arterial wall elasticity. The obtained Young modulus is compared with the one obtained by a more classical approach: pressure-diameter relationships. As a sample an arterial phantom made of PolyVinyl Alcohol (PVA) gel was used. Diameter variation due to pressure variation inside the phantom was recorded by means of ultrasound. Through both techniques similar Young modulus estimations are obtained showing in this way the feasibility of applying transient elastography for the arterial wall elasticity assessment.

Transient gestational and neonatal hypothyroidism-induced specific changes in androgen receptor expression in skeletal and cardiac muscles of adult rat.

PubMed

Annapoorna, K; Anbalagan, J; Neelamohan, R; Vengatesh, G; Stanley, J; Amudha, G; Aruldhas, M M

2013-03-01

The present study aims to identify the association between androgen status and metabolic activity in skeletal and cardiac muscles of adult rats with transient gestational/neonatal-onset hypothyroidism. Pregnant and lactating rats were made hypothyroid by exposing to 0.05% methimazole in drinking water; gestational exposure was from embryonic day 9-14 (group II) or 21 (group III), lactational exposure was from postnatal day 1-14 (group IV) or 29 (group V). Serum was collected for hormone assay. Androgen receptor status, Glu-4 expression, and enzyme activities were assessed in the skeletal and cardiac muscles. Serum testosterone and estradiol levels decreased in adult rats of groups II and III, whereas testosterone remained normal but estradiol increased in group IV and V, when compared to coeval control. Androgen receptor ligand binding activity increased in both muscle phenotypes with a consistent increase in the expression level of its mRNA and protein expressions except in the forelimb of adult rats with transient hypothyroidism (group II-V). Glut-4 expression remained normal in skeletal and cardiac muscle of experimental rats. Specific activity of hexokinase and lactate dehydrogenase increased in both muscle phenotypes whereas, creatine kinase activity increased in skeletal muscles alone. It is concluded that transient gestational/lactational exposure to methimazole results in hypothyroidism during prepuberal life whereas it increases AR status and glycolytic activity in skeletal and cardiac muscles even at adulthood. Thus, the present study suggests that euthyroid status during prenatal and early postnatal life is essential to have optimal AR status and metabolic activity at adulthood. © Georg Thieme Verlag KG Stuttgart · New York.

Increased spring freezing vulnerability for alpine shrubs under early snowmelt.

PubMed

Wheeler, J A; Hoch, G; Cortés, A J; Sedlacek, J; Wipf, S; Rixen, C

2014-05-01

Alpine dwarf shrub communities are phenologically linked with snowmelt timing, so early spring exposure may increase risk of freezing damage during early development, and consequently reduce seasonal growth. We examined whether environmental factors (duration of snow cover, elevation) influenced size and the vulnerability of shrubs to spring freezing along elevational gradients and snow microhabitats by modelling the past frequency of spring freezing events. We sampled biomass and measured the size of Salix herbacea, Vaccinium myrtillus, Vaccinium uliginosum and Loiseleuria procumbens in late spring. Leaves were exposed to freezing temperatures to determine the temperature at which 50% of specimens are killed for each species and sampling site. By linking site snowmelt and temperatures to long-term climate measurements, we extrapolated the frequency of spring freezing events at each elevation, snow microhabitat and per species over 37 years. Snowmelt timing was significantly driven by microhabitat effects, but was independent of elevation. Shrub growth was neither enhanced nor reduced by earlier snowmelt, but decreased with elevation. Freezing resistance was strongly species dependent, and did not differ along the elevation or snowmelt gradient. Microclimate extrapolation suggested that potentially lethal freezing events (in May and June) occurred for three of the four species examined. Freezing events never occurred on late snow beds, and increased in frequency with earlier snowmelt and higher elevation. Extrapolated freezing events showed a slight, non-significant increase over the 37-year record. We suggest that earlier snowmelt does not enhance growth in four dominant alpine shrubs, but increases the risk of lethal spring freezing exposure for less freezing-resistant species.

ILLICIT DOPAMINE TRANSIENTS: RECONCILING ACTIONS OF ABUSED DRUGS

PubMed Central

Covey, Dan P.; Roitman, Mitchell F.; Garris, Paul A.

2014-01-01

Phasic increases in brain dopamine are required for cue-directed reward seeking. While compelling within the framework of appetitive behavior, the view that illicit drugs hijack reward circuits by hyper-activating these dopamine transients is inconsistent with established psychostimulant pharmacology. However, recent work reclassifying amphetamine (AMPH), cocaine, and other addictive dopamine-transporter inhibitors (DAT-Is) supports transient hyper-activation as a unifying hypothesis of abused drugs. We argue here that reclassification also identifies generating burst firing by dopamine neurons as a keystone action. Unlike natural rewards, which are processed by sensory systems, drugs act directly on the brain. Consequently, to mimic natural reward and exploit reward circuits, dopamine transients must be elicited de novo. Of available drug targets, only burst firing achieves this essential outcome. PMID:24656971

Features of Chaotic Transients in Excitable Media Governed by Spiral and Scroll Waves

NASA Astrophysics Data System (ADS)

Lilienkamp, Thomas; Christoph, Jan; Parlitz, Ulrich

2017-08-01

In excitable media, chaotic dynamics governed by spiral or scroll waves is often not persistent but transient. Using extensive simulations employing different mathematical models we identify a specific type-II supertransient by an exponential increase of transient lifetimes with the system size in 2D and an investigation of the dynamics (number and lifetime of spiral waves, Kaplan-Yorke dimension). In 3D, simulations exhibit an increase of transient lifetimes and filament lengths only above a critical thickness. Finally, potential implications for understanding cardiac arrhythmias are discussed.

Transient pseudohypoaldosteronism in infancy secondary to urinary tract infection.

PubMed

Abraham, Mary B; Larkins, Nicholas; Choong, Catherine S; Shetty, Vinutha B

2017-05-01

Hyponatraemia with hyperkalaemia in infancy is a typical presentation of congenital adrenal hyperplasia. In the presence of pyelonephritis, the same biochemical picture can occur with transient type 1 pseudohypoaldosteronism (PHA-1) also termed type 4 renal tubular acidosis. Recognition of PHA-1 enables appropriate management thus avoiding unnecessary investigations and treatment. To improve awareness of this condition, we present a case series to highlight the clinical and biochemical features of PHA-1. A retrospective chart review of patients diagnosed with transient PHA-1 at a tertiary children's hospital in Western Australia was conducted. Five male infants (32 days to 6 months) with transient PHA-1 were identified. Failure to thrive was the most common symptom with hyponatraemia on presentation. Two infants had antenatally diagnosed bilateral hydronephrosis and urinary tract infection (UTI) on admission. Two infants were treated for congenital adrenal hyperplasia and received hydrocortisone. All infants had UTI and required parenteral antibiotics. The condition was transient and hyponatraemia corrected by day 4 in all infants. There was no correlation between plasma sodium and aldosterone levels. The severity of PHA-1 was independent of the underlying renal anomaly. Four infants had hydronephrosis and vesicoureteric reflux. Surgical intervention was required in two infants. PHA-1 may be precipitated by UTI or urinary tract anomalies in early infancy. Urine analysis should be performed in infants with hyponatraemia. Diagnosis of PHA-1 facilitates appropriate renal investigations to reduce long-term morbidity. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

The Effect of Early Visual Deprivation on the Neural Bases of Auditory Processing.

PubMed

Guerreiro, Maria J S; Putzar, Lisa; Röder, Brigitte

2016-02-03

Transient congenital visual deprivation affects visual and multisensory processing. In contrast, the extent to which it affects auditory processing has not been investigated systematically. Research in permanently blind individuals has revealed brain reorganization during auditory processing, involving both intramodal and crossmodal plasticity. The present study investigated the effect of transient congenital visual deprivation on the neural bases of auditory processing in humans. Cataract-reversal individuals and normally sighted controls performed a speech-in-noise task while undergoing functional magnetic resonance imaging. Although there were no behavioral group differences, groups differed in auditory cortical responses: in the normally sighted group, auditory cortex activation increased with increasing noise level, whereas in the cataract-reversal group, no activation difference was observed across noise levels. An auditory activation of visual cortex was not observed at the group level in cataract-reversal individuals. The present data suggest prevailing auditory processing advantages after transient congenital visual deprivation, even many years after sight restoration. The present study demonstrates that people whose sight was restored after a transient period of congenital blindness show more efficient cortical processing of auditory stimuli (here speech), similarly to what has been observed in congenitally permanently blind individuals. These results underscore the importance of early sensory experience in permanently shaping brain function. Copyright © 2016 the authors 0270-6474/16/361620-11$15.00/0.

Increasing pre-kindergarten early literacy skills in children with developmental disabilities and delays.

PubMed

Pears, Katherine C; Kim, Hyoun K; Fisher, Philip A; Yoerger, Karen

2016-08-01

Two hundred and nine children receiving early childhood special education services for developmental disabilities or delays who also had behavioral, social, or attentional difficulties were included in a study of an intervention to increase school readiness, including early literacy skills. Results showed that the intervention had a significant positive effect on children's literacy skills from baseline to the end of summer before the start of kindergarten (d=.14). The intervention also had significant indirect effects on teacher ratings of children's literacy skills during the fall of their kindergarten year (β=.09). Additionally, when scores were compared to standard benchmarks, a greater percentage of the children who received the intervention moved from being at risk for reading difficulties to having low risk. Overall, this study demonstrates that a school readiness intervention delivered prior to the start of kindergarten may help increase children's early literacy skills. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

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.

Transient Hypothyroidism During Lactation Arrests Myelination in the Anterior Commissure of Rats. A Magnetic Resonance Image and Electron Microscope Study.

PubMed

Lucia, Federico S; Pacheco-Torres, Jesús; González-Granero, Susana; Canals, Santiago; Obregón, María-Jesús; García-Verdugo, José M; Berbel, Pere

2018-01-01

Thyroid hormone deficiency at early postnatal ages affects the cytoarchitecture and function of neocortical and telencephalic limbic areas, leading to impaired associative memory and in a wide spectrum of neurological and mental diseases. Neocortical areas project interhemispheric axons mostly through the corpus callosum and to a lesser extent through the anterior commissure (AC), while limbic areas mostly project through the AC and hippocampal commissures. Functional magnetic resonance data from children with late diagnosed congenital hypothyroidism and abnormal verbal memory processing, suggest altered ipsilateral and contralateral telencephalic connections. Gestational hypothyroidism affects AC development but the possible effect of transient and chronic postnatal hypothyroidism, as occurs in late diagnosed neonates with congenital hypothyroidism and in children growing up in iodine deficient areas, still remains unknown. We studied AC development using in vivo magnetic resonance imaging and electron microscopy in hypothyroid and control male rats. Four groups of methimazole (MMI) treated rats were studied. One group was MMI-treated from postnatal day (P) 0 to P21; some of these rats were also treated with L-thyroxine (T4) from P15 to P21, as a model for early transient hypothyroidism. Other rats were MMI-treated from P0 to P150 and from embryonic day (E) 10 to P170, as a chronic hypothyroidism group. The results were compared with age paired control rats. The normalized T2 signal using magnetic resonance image was higher in MMI-treated rats and correlated with the number and percentage of myelinated axons. Using electron microscopy, we observed decreased myelinated axon number and density in transient and chronic hypothyroid rats at P150, unmyelinated axon number increased slightly in chronic hypothyroid rats. In MMI-treated rats, the myelinated axon g-ratio and conduction velocity was similar to control rats, but with a decrease in conduction delays. These

Quantification of transient increase of the blood–brain barrier permeability to macromolecules by optimized focused ultrasound combined with microbubbles

PubMed Central

Shi, Lingyan; Palacio-Mancheno, Paolo; Badami, Joseph; Shin, Da Wi; Zeng, Min; Cardoso, Luis; Tu, Raymond; Fu, Bingmei M

2014-01-01

Radioimmunotherapy using a radiolabeled monoclonal antibody that targets tumor cells has been shown to be efficient for the treatment of many malignant cancers, with reduced side effects. However, the blood–brain barrier (BBB) inhibits the transport of intravenous antibodies to tumors in the brain. Recent studies have demonstrated that focused ultrasound (FUS) combined with microbubbles (MBs) is a promising method to transiently disrupt the BBB for the drug delivery to the central nervous system. To find the optimal FUS and MBs that can induce reversible increase in the BBB permeability, we employed minimally invasive multiphoton microscopy to quantify the BBB permeability to dextran-155 kDa with similar molecular weight to an antibody by applying different doses of FUS in the presence of MBs with an optimal size and concentration. The cerebral microcirculation was observed through a section of frontoparietal bone thinned with a micro-grinder. About 5 minutes after applying the FUS on the thinned skull in the presence of MBs for 1 minute, TRITC (tetramethylrhodamine isothiocyanate)-dextran-155 kDa in 1% bovine serum albumin in mammalian Ringer’s solution was injected into the cerebral circulation via the ipsilateral carotid artery by a syringe pump. Simultaneously, the temporal images were collected from the brain parenchyma ~100–200 μm below the pia mater. Permeability was determined from the rate of tissue solute accumulation around individual microvessels. After several trials, we found the optimal dose of FUS. At the optimal dose, permeability increased by ~14-fold after 5 minutes post-FUS, and permeability returned to the control level after 25 minutes. FUS without MBs or MBs injected without FUS did not change the permeability. Our method provides an accurate in vivo assessment for the transient BBB permeability change under the treatment of FUS. The optimal FUS dose found for the reversible BBB permeability increase without BBB disruption is reliable

An empirical model for transient crater growth in granular targets based on direct observations

NASA Astrophysics Data System (ADS)

Yamamoto, Satoru; Barnouin-Jha, Olivier S.; Toriumi, Takashi; Sugita, Seiji; Matsui, Takafumi

2009-09-01

The present paper describes observations of crater growth up to the time of transient crater formation and presents a new empirical model for transient crater growth as a function of time. Polycarbonate projectiles were impacted vertically into soda-lime glass sphere targets using a single-stage light-gas gun. Using a new technique with a laser sheet illuminating the target [Barnouin-Jha, O.S., Yamamoto, S., Toriumi, T., Sugita, S., Matsui, T., 2007. Non-intrusive measurements of the crater growth. Icarus, 188, 506-521], we measured the temporal change in diameter of crater cavities (diameter growth). The rate of increase in diameter at early times follows a power law relation, but the data at later times (before the end of transient crater formation) deviates from the power law relation. In addition, the power law exponent at early times and the degree of deviation from a power law at later times depend on the target. In order to interpret these features, we proposed to modify Maxwell's Z-model under the assumption that the strength of the excavation flow field decreases exponentially with time. We also derived a diameter growth model as: d(t)∝[1-exp(-βt)]γ, where d(t) is the apparent diameter of the crater cavity at time t after impact, and β and γ are constants. We demonstrated that the diameter growth model could represent well the experimental data for various targets with different target material properties, such as porosity or angle of repose. We also investigated the diameter growth for a dry sand target, which has been used to formulate previous scaling relations. The obtained results showed that the dry sand target has larger degree of deviation from a power law, indicating that the target material properties of the dry sand target have a significant effect on diameter growth, especially at later times. This may suggest that the previously reported scaling relations should be reexamined in order to account for the late-stage behavior with the

Transient increase in alcohol self-administration following a period of chronic exposure to corticosterone

PubMed Central

Besheer, Joyce; Fisher, Kristen R.; Lindsay, Tessa G.; Cannady, Reginald

2013-01-01

Stressful life events and chronic stressors have been associated with escalations in alcohol drinking. Stress exposure leads to the secretion of glucocorticoids (cortisol in the human; corticosterone (CORT) in the rodent). To model a period of heightened elevations in CORT, the present work assessed the effects of chronic exposure to the stress hormone CORT on alcohol self-administration. Male Long Evans rats were trained to self-administer a sweetened alcohol solution (2% sucrose/15% alcohol) resulting in moderate levels of daily alcohol intake (0.5–0.7 g/kg). Following stable baseline operant self-administration, rats received CORT in the drinking water for 7 days. A transient increase in alcohol self-administration was observed on the first self-administration session following CORT exposure, and behavior returned to control levels by the second session. Control experiments determined that this increase in alcohol self-administration was specific to alcohol, unrelated to general motor activation, and functionally dissociated from decreased CORT levels at the time of testing. These results indicate that repeated exposure to heightened levels of stress hormone (e.g., as may be experienced during stressful episodes) has the potential to lead to exacerbated alcohol intake in low to moderate drinkers. Given that maladaptive drinking patterns, such as escalated alcohol drinking following stressful episodes, have the potential to put an individual at risk for future drinking disorders, utilization of this model will be important for examination of neuroadaptations that occur as a consequence of CORT exposure in order to better understand escalated drinking following stressful episodes in nondependent individuals. PMID:23643750

Sensing of blood pressure increase by transient receptor potential vanilloid 1 receptors on baroreceptors.

PubMed

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N; Pan, Hui-Lin

2009-12-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis.

Sensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on Baroreceptors

PubMed Central

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N.

2009-01-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis. PMID:19726694

Transient oxytocin signaling primes the development and function of excitatory hippocampal neurons

PubMed Central

Ripamonti, Silvia; Ambrozkiewicz, Mateusz C; Guzzi, Francesca; Gravati, Marta; Biella, Gerardo; Bormuth, Ingo; Hammer, Matthieu; Tuffy, Liam P; Sigler, Albrecht; Kawabe, Hiroshi; Nishimori, Katsuhiko; Toselli, Mauro; Brose, Nils; Parenti, Marco; Rhee, JeongSeop

2017-01-01

Beyond its role in parturition and lactation, oxytocin influences higher brain processes that control social behavior of mammals, and perturbed oxytocin signaling has been linked to the pathogenesis of several psychiatric disorders. However, it is still largely unknown how oxytocin exactly regulates neuronal function. We show that early, transient oxytocin exposure in vitro inhibits the development of hippocampal glutamatergic neurons, leading to reduced dendrite complexity, synapse density, and excitatory transmission, while sparing GABAergic neurons. Conversely, genetic elimination of oxytocin receptors increases the expression of protein components of excitatory synapses and excitatory synaptic transmission in vitro. In vivo, oxytocin-receptor-deficient hippocampal pyramidal neurons develop more complex dendrites, which leads to increased spine number and reduced γ-oscillations. These results indicate that oxytocin controls the development of hippocampal excitatory neurons and contributes to the maintenance of a physiological excitation/inhibition balance, whose disruption can cause neurobehavioral disturbances. DOI: http://dx.doi.org/10.7554/eLife.22466.001 PMID:28231043

Spontaneous calcium transients in human neural progenitor cells mediated by transient receptor potential channels.

PubMed

Morgan, Peter J; Hübner, Rayk; Rolfs, Arndt; Frech, Moritz J

2013-09-15

Calcium signals affect many developmental processes, including proliferation, migration, survival, and apoptosis, processes that are of particular importance in stem cells intended for cell replacement therapies. The mechanisms underlying Ca(2+) signals, therefore, have a role in determining how stem cells respond to their environment, and how these responses might be controlled in vitro. In this study, we examined the spontaneous Ca(2+) activity in human neural progenitor cells during proliferation and differentiation. Pharmacological characterization indicates that in proliferating cells, most activity is the result of transient receptor potential (TRP) channels that are sensitive to Gd(3+) and La(3+), with the more subtype selective antagonist Ruthenium red also reducing activity, suggesting the involvement of transient receptor potential vanilloid (TRPV) channels. In differentiating cells, Gd(3+) and La(3+)-sensitive TRP channels also appear to underlie the spontaneous activity; however, no sub-type-specific antagonists had any effect. Protein levels of TRPV2 and TRPV3 decreased in differentiated cells, which is demonstrated by western blot. Thus, it appears that TRP channels represent the main route of Ca(2+) entry in human neural progenitor cells (hNPCs), but the responsible channel types are subject to substitution under differentiating conditions. The level of spontaneous activity could be increased and decreased by lowering and raising the extracellular K(+) concentration. Proliferating cells in low K(+) slowed the cell cycle, with a disproportionate increased percentage of cells in G1 phase and a reduction in S phase. Taken together, these results suggest a link between external K(+) concentration, spontaneous Ca(2+) transients, and cell cycle distribution, which is able to influence the fate of stem and progenitor cells.

Measurand transient signal suppressor

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr. (Inventor)

1994-01-01

A transient signal suppressor for use in a controls system which is adapted to respond to a change in a physical parameter whenever it crosses a predetermined threshold value in a selected direction of increasing or decreasing values with respect to the threshold value and is sustained for a selected discrete time interval is presented. The suppressor includes a sensor transducer for sensing the physical parameter and generating an electrical input signal whenever the sensed physical parameter crosses the threshold level in the selected direction. A manually operated switch is provided for adapting the suppressor to produce an output drive signal whenever the physical parameter crosses the threshold value in the selected direction of increasing or decreasing values. A time delay circuit is selectively adjustable for suppressing the transducer input signal for a preselected one of a plurality of available discrete suppression time and producing an output signal only if the input signal is sustained for a time greater than the selected suppression time. An electronic gate is coupled to receive the transducer input signal and the timer output signal and produce an output drive signal for energizing a control relay whenever the transducer input is a non-transient signal which is sustained beyond the selected time interval.

Transient Numerical Modeling of Catalytic Channels

NASA Technical Reports Server (NTRS)

Struk, Peter M.; Dietrich, Daniel L.; Miller, Fletcher J.; T'ien, James S.

2007-01-01

This paper presents a transient model of catalytic combustion suitable for isolated channels and monolith reactors. The model is a lumped two-phase (gas and solid) model where the gas phase is quasi-steady relative to the transient solid. Axial diffusion is neglected in the gas phase; lateral diffusion, however, is accounted for using transfer coefficients. The solid phase includes axial heat conduction and external heat loss due to convection and radiation. The combustion process utilizes detailed gas and surface reaction models. The gas-phase model becomes a system of stiff ordinary differential equations while the solid phase reduces, after discretization, into a system of stiff ordinary differential-algebraic equations. The time evolution of the system came from alternating integrations of the quasi-steady gas and transient solid. This work outlines the numerical model and presents some sensitivity studies on important parameters including internal transfer coefficients, catalytic surface site density, and external heat-loss (if applicable). The model is compared to two experiments using CO fuel: (1) steady-state conversion through an isothermal platinum (Pt) tube and (2) transient propagation of a catalytic reaction inside a small Pt tube. The model requires internal mass-transfer resistance to match the experiments at lower residence times. Under mass-transport limited conditions, the model reasonably predicted exit conversion using global mass-transfer coefficients. Near light-off, the model results did not match the experiment precisely even after adjustment of mass-transfer coefficients. Agreement improved for the first case after adjusting the surface kinetics such that the net rate of CO adsorption increased compared to O2. The CO / O2 surface mechanism came from a sub-set of reactions in a popular CH4 / O2 mechanism. For the second case, predictions improved for lean conditions with increased external heat loss or adjustment of the kinetics as in the

Exposure to dim light at night during early development increases adult anxiety-like responses.

PubMed

Borniger, Jeremy C; McHenry, Zachary D; Abi Salloum, Bachir A; Nelson, Randy J

2014-06-22

Early experiences produce effects that may persist throughout life. Therefore, to understand adult phenotype, it is important to investigate the role of early environmental stimuli in adult behavior and health. Artificial light at night (LAN) is an increasingly common phenomenon throughout the world. However, animals, including humans, evolved under dark night conditions. Many studies have revealed affective, immune, and metabolic alterations provoked by aberrant light exposure and subsequent circadian disruption. Pups are receptive to entraining cues from the mother and then light early during development, raising the possibility that the early life light environment may influence subsequent behavior. Thus, to investigate potential influences of early life exposure to LAN on adult phenotype, we exposed mice to dim (~5 lux; full spectrum white light) or dark (~0 lux) nights pre- and/or postnatally. After weaning at 3 weeks of age, all mice were maintained in dark nights until adulthood (9 weeks of age) when behavior was assessed. Mice exposed to dim light in early life increased anxiety-like behavior and fearful responses on the elevated plus maze and passive avoidance tests. These mice also displayed reduced growth rates, which ultimately normalized during adolescence. mRNA expression of brain derived neurotrophic factor (BDNF), a neurotrophin previously linked to early life environment and adult phenotype, was not altered in the prefrontal cortex or hippocampus by early life LAN exposure. Serum corticosterone concentrations were similar between groups at weaning, suggesting that early life LAN does not elicit a long-term physiologic stress response. Dim light exposure did not influence behavior on the open field, novel object, sucrose anhedonia, or forced swim tests. Our data highlight the potential deleterious consequences of low levels of light during early life to development and subsequent behavior. Whether these changes are due to altered maternal behavior

Transient physical and psychosocial activities increase the risk of nonpersistent and persistent low back pain: a case-crossover study with 12 months follow-up.

PubMed

Machado, Gustavo C; Ferreira, Paulo H; Maher, Chris G; Latimer, Jane; Steffens, Daniel; Koes, Bart W; Li, Qiang; Ferreira, Manuela L

2016-12-01

A previous study has shown that transient physical and psychosocial activities increased the risk of developing low back pain. However, the link between these factors in triggering nonpersistent or persistent episodes remains unclear. We aimed to investigate the association of transient exposures to physical and psychosocial activities with the development of nonpersistent or persistent low back pain. This was a case-crossover study with 12 months follow-up. We included 999 consecutive participants seeking care for a sudden onset of low back pain. Development of low back pain was the outcome measure. At baseline, participants reported transient exposures to 12 predefined activities over the 4 days preceding pain onset. After 12 months, participants were asked whether they had recovered and the date of recovery. Exposures in the 2-hour period preceding pain onset (case window) were compared with the 2-hour period, 24 hours before pain onset (control window) in a case-crossover design for all participants. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CI), and interaction analyses were used to compare estimates of nonpersistent (i.e., <6 weeks duration) and persistent cases. This study received funding from Australia's National Health and Medical Research Council (APP1003608). There were 832 participants (83%) who completed the 12 months follow-up successfully. Of these, 430 participants had nonpersistent low back pain (<6 weeks duration), whereas 352 reported persistent symptoms (≥6 weeks duration). Exposure to several transient activities, such as manual tasks involving heavy loads, awkward postures, live people or animals, moderate or vigorous physical activity, and being fatigued or tired during a task or activity, significantly increased the risk of both nonpersistent and persistent low back pain, with ORs ranging from 2.9 to 11.7. Overall, the risk of developing a persistent or a nonpersistent episode of

Increased amygdala reactivity following early life stress: a potential resilience enhancer role.

PubMed

Yamamoto, Tetsuya; Toki, Shigeru; Siegle, Greg J; Takamura, Masahiro; Takaishi, Yoshiyuki; Yoshimura, Shinpei; Okada, Go; Matsumoto, Tomoya; Nakao, Takashi; Muranaka, Hiroyuki; Kaseda, Yumiko; Murakami, Tsuneji; Okamoto, Yasumasa; Yamawaki, Shigeto

2017-01-18

Amygdala hyper-reactivity is sometimes assumed to be a vulnerability factor that predates depression; however, in healthy people, who experience early life stress but do not become depressed, it may represent a resilience mechanism. We aimed to test these hypothesis examining whether increased amygdala activity in association with a history of early life stress (ELS) was negatively or positively associated with depressive symptoms and impact of negative life event stress in never-depressed adults. Twenty-four healthy participants completed an individually tailored negative mood induction task during functional magnetic resonance imaging (fMRI) assessment along with evaluation of ELS. Mood change and amygdala reactivity were increased in never-depressed participants who reported ELS compared to participants who reported no ELS. Yet, increased amygdala reactivity lowered effects of ELS on depressive symptoms and negative life events stress. Amygdala reactivity also had positive functional connectivity with the bilateral DLPFC, motor cortex and striatum in people with ELS during sad memory recall. Increased amygdala activity in those with ELS was associated with decreased symptoms and increased neural features, consistent with emotion regulation, suggesting that preservation of robust amygdala reactions may reflect a stress buffering or resilience enhancing factor against depression and negative stressful events.

Illicit dopamine transients: reconciling actions of abused drugs.

PubMed

Covey, Dan P; Roitman, Mitchell F; Garris, Paul A

2014-04-01

Phasic increases in brain dopamine are required for cue-directed reward seeking. Although compelling within the framework of appetitive behavior, the view that illicit drugs hijack reward circuits by hyperactivating these dopamine transients is inconsistent with established psychostimulant pharmacology. However, recent work reclassifying amphetamine (AMPH), cocaine, and other addictive dopamine-transporter inhibitors (DAT-Is) supports transient hyperactivation as a unifying hypothesis of abused drugs. We argue here that reclassification also identifies generating burst firing by dopamine neurons as a keystone action. Unlike natural rewards, which are processed by sensory systems, drugs act directly on the brain. Consequently, to mimic natural rewards and exploit reward circuits, dopamine transients must be elicited de novo. Of available drug targets, only burst firing achieves this essential outcome. Copyright © 2014 Elsevier Ltd. All rights reserved.

A New Class of Transients Marking Intensified Accretion onto Supermassive Black Holes

NASA Astrophysics Data System (ADS)

Trakhtenbrot, Benny; Arcavi, Iair; Ricci, Claudio; Horesh, Assaf; Tacchella, Sandro; Stern, Daniel

2018-01-01

Our understanding of the demographics and evolution of supermassive black holes (SMBHs) beyond the local universe is limited to actively growing SMBHs, where relatively stable accretion of gas persists over several hundreds of millions of years. A growing number of transient and/or variable phenomena in galaxy nuclei have recently begun to shed new light on SMBH demographics and the physics of gas accretion onto these objects, tracing events where this accretion has drastically intensified. We present such an event, identified in the nucleus of an early-type galaxy at z=0.064, in which a previously-active SMBH experienced a dramatic increase in ultraviolet-optical emission. The emerging optical spectrum exhibits a mix of emission features, some of which are typical of luminous, unobscured active galactic nuclei. Other observed emission features of high-ionization species are likely driven by Bowen fluorescence -- seen for the first time in high-velocity lines, with ~2000 km/s, in a galaxy nucleus -- originating in dense, metal-rich gas that is exposed to the recently intensified UV radiation. Our multiwavelength space- and ground-based monitoring campaign shows that the spectral features and elevated UV flux show little to no evolution, over a period of at least six months. This disfavours the tidal disruption of a star as the origin of the UV “flash”, but suggests a rather longer-term re-ignition event. This event joins two other recently reported transients with similar emission properties, forming a new class of transients which has important implications for the identification and understanding of tidal disruption events, as well as other drivers of SMBH re-ignition.

VOEventNet: An Open Source of Transient Alerts for Astronomers.

NASA Astrophysics Data System (ADS)

Drake, Andrew J.; Williams, R.; Graham, M. J.; Mahabal, A.; Djorgovski, S. G.; White, R. R.; Vestrand, W. T.; Bloom, J.

2007-12-01

Event based astronomy is acquiring an increasingly important role in astronomy as large time-domain surveys such as Palomar Transient Factory (PTF), Pan-STARRs, SkyMapper and Allan Telescope Array (ATA) surveys come online. These surveys are expected to discover thousands of transients each year ranging from near earth asteroids to distant SNe. Although the primary instruments for of these surveys are in place, in order to fully utilize these event discovery streams, automated alerting and follow-up is a necessity. For the past two years the VOEventNet network has been globally distributing information about transient astronomical events using the VOEvent format, a Virtual Observatory standard. Events messages are openly distributed so that follow-up can utilize the most appropriate resources available in order to characterize the nature of the transients. Since its inception VOEventNet has broadcast more than 3500 SDSSSS Supernova candidates, 3300 GRB alert and follow-up notices from GCN, 700 OGLE microlensing event candidates, and 4300 newly discovered asteroid and optical transient candidates from the Palomar Quest survey. Additional transient event streams are expected this season including optical transients from the Catalina Sky Survey. VOEventNet astronomical transient events streams are available to all astronomers via traditional HTML tables, RSS news-feeds, real-time publication (via Jabber and TCP), and Google Sky mashups. VOEventNet currently carries out optical transient event follow-up with the Palomar 60 and 200in (Caltech), Faulkes Telescopes North and South (LCOGTN), RAPTOR (LANL), and PARITEL (UCB; CfA).

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.

Early Boost and Slow Consolidation in Motor Skill Learning

ERIC Educational Resources Information Center

Hotermans, Christophe; Peigneux, Philippe; de Noordhout, Alain Maertens; Moonen, Gustave; Maquet, Pierre

2006-01-01

Motor skill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as…

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.

Substance P modulates localized calcium transients and membrane current responses in murine colonic myocytes

PubMed Central

Bayguinov, Orline; Hagen, Brian; Sanders, Kenton M

2003-01-01

Neurokinins contribute to the neural regulation of gastrointestinal (GI) smooth muscles. We studied responses of murine colonic smooth muscle cells to substance P (SP) and NK1 and NK2 agonists using confocal microscopy and the patch clamp technique. Colonic myocytes generated localized Ca2+ transients that were coupled to spontaneous transient outward currents (STOCs). SP (10−10 M) increased Ca2+ transients and STOCs. Higher concentrations of SP (10−6 M) increased basal Ca2+ and inhibited Ca2+ transients and STOCs. Effects of SP were due to increased Ca2+ entry via L-type Ca2+ channels, and were mediated by protein kinase C (PKC). Nifedipine (10−6 M) and the PKC inhibitor, GF 109203X (10−6 M) reduced L-type Ca2+ current and blocked the effects of SP. SP responses depended upon parallel stimulation of NK1 and NK2 receptors. NK1 agonist ([Sar9,Met(O2)11]-substance P; SSP) and NK2 agonists (neurokinin A (NKA) or GR-64349) did not mimic the effects of SP alone, but NK1 and NK2 agonists were effective when added in combination (10−10–10−6 M). Consistent with this, either an NK1-specific antagonist (GR-82334; 10−7 M) or an NK2-specific antagonist (MEN 10,627; 10−7 M) blocked responses to SP (10−6 M). Ryanodine (10−5 M) blocked the increase in Ca2+ transients and STOCs in response to SP (10−10 M). Our findings show that low concentrations of SP, via PKC-dependent enhancement of L-type Ca2+ current and recruitment of ryanodine receptors, stimulate Ca2+ transients. At higher concentrations of SP (10−6 M), basal Ca2+ increases and spontaneous Ca2+ transients and STOCs are inhibited. PMID:12711623

The SED Machine: A Robotic Spectrograph for Fast Transient Classification

NASA Astrophysics Data System (ADS)

Blagorodnova, Nadejda; Neill, James D.; Walters, Richard; Kulkarni, Shrinivas R.; Fremling, Christoffer; Ben-Ami, Sagi; Dekany, Richard G.; Fucik, Jason R.; Konidaris, Nick; Nash, Reston; Ngeow, Chow-Choong; Ofek, Eran O.; O’ Sullivan, Donal; Quimby, Robert; Ritter, Andreas; Vyhmeister, Karl E.

2018-03-01

Current time domain facilities are finding several hundreds of transient astronomical events a year. The discovery rate is expected to increase in the future as soon as new surveys such as the Zwicky Transient Facility (ZTF) and the Large Synoptic Sky Survey (LSST) come online. Presently, the rate at which transients are classified is approximately one order or magnitude lower than the discovery rate, leading to an increasing “follow-up drought”. Existing telescopes with moderate aperture can help address this deficit when equipped with spectrographs optimized for spectral classification. Here, we provide an overview of the design, operations and first results of the Spectral Energy Distribution Machine (SEDM), operating on the Palomar 60-inch telescope (P60). The instrument is optimized for classification and high observing efficiency. It combines a low-resolution (R ∼ 100) integral field unit (IFU) spectrograph with “Rainbow Camera” (RC), a multi-band field acquisition camera which also serves as multi-band (ugri) photometer. The SEDM was commissioned during the operation of the intermediate Palomar Transient Factory (iPTF) and has already lived up to its promise. The success of the SEDM demonstrates the value of spectrographs optimized for spectral classification.

Learning in shifts of transient attention improves recognition of parts of ambiguous figure-ground displays.

PubMed

Kristjánsson, Arni

2009-04-24

Previously demonstrated learning effects in shifts of transient attention have only been shown to result in beneficial effects upon secondary discrimination tasks and affect landing points of express saccades. Can such learning result in more direct effects upon perception than previously demonstrated? Observers performed a cued Vernier acuity discrimination task where the cue was one of a set of ambiguous figure-ground displays (with a black and white part). The critical measure was whether, if a target appeared consistently within a part of a cue of a certain brightness, this would result in learning effects and whether such learning would then affect recognition of the cue parts. Critically the target always appeared within the same part of each individual cue. Some cues were used in early parts of streaks of repetition of cue-part brightness, and others in latter parts of such streaks. All the observers showed learning in shifts of transient attention, with improved performance the more often the target appeared within the part of the cue of the same brightness. Subsequently the observers judged whether cue-parts had been parts of the cues used on the preceding discrimination task. Recognition of the figure parts, where the target had consistently appeared, improved strongly with increased length of streaks of repetition of cue-part brightness. Learning in shifts of transient attention leads not only to faster attention shifts but to direct effects upon perception, in this case recognition of parts of figure-ground ambiguous cues.

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

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.

Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra

PubMed Central

Lindaas, Jakob; Benmergui, Joshua; Luus, Kristina A.; Chang, Rachel Y.-W.; Daube, Bruce C.; Euskirchen, Eugénie S.; Karion, Anna; Miller, John B.; Miller, Scot M.; Parazoo, Nicholas C.; Randerson, James T.; Sweeney, Colm; Thoning, Kirk; Veraverbeke, Sander; Miller, Charles E.; Wofsy, Steven C.

2017-01-01

High-latitude ecosystems have the capacity to release large amounts of carbon dioxide (CO2) to the atmosphere in response to increasing temperatures, representing a potentially significant positive feedback within the climate system. Here, we combine aircraft and tower observations of atmospheric CO2 with remote sensing data and meteorological products to derive temporally and spatially resolved year-round CO2 fluxes across Alaska during 2012–2014. We find that tundra ecosystems were a net source of CO2 to the atmosphere annually, with especially high rates of respiration during early winter (October through December). Long-term records at Barrow, AK, suggest that CO2 emission rates from North Slope tundra have increased during the October through December period by 73% ± 11% since 1975, and are correlated with rising summer temperatures. Together, these results imply increasing early winter respiration and net annual emission of CO2 in Alaska, in response to climate warming. Our results provide evidence that the decadal-scale increase in the amplitude of the CO2 seasonal cycle may be linked with increasing biogenic emissions in the Arctic, following the growing season. Early winter respiration was not well simulated by the Earth System Models used to forecast future carbon fluxes in recent climate assessments. Therefore, these assessments may underestimate the carbon release from Arctic soils in response to a warming climate. PMID:28484001

Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra.

PubMed

Commane, Róisín; Lindaas, Jakob; Benmergui, Joshua; Luus, Kristina A; Chang, Rachel Y-W; Daube, Bruce C; Euskirchen, Eugénie S; Henderson, John M; Karion, Anna; Miller, John B; Miller, Scot M; Parazoo, Nicholas C; Randerson, James T; Sweeney, Colm; Tans, Pieter; Thoning, Kirk; Veraverbeke, Sander; Miller, Charles E; Wofsy, Steven C

2017-05-23

High-latitude ecosystems have the capacity to release large amounts of carbon dioxide (CO 2 ) to the atmosphere in response to increasing temperatures, representing a potentially significant positive feedback within the climate system. Here, we combine aircraft and tower observations of atmospheric CO 2 with remote sensing data and meteorological products to derive temporally and spatially resolved year-round CO 2 fluxes across Alaska during 2012-2014. We find that tundra ecosystems were a net source of CO 2 to the atmosphere annually, with especially high rates of respiration during early winter (October through December). Long-term records at Barrow, AK, suggest that CO 2 emission rates from North Slope tundra have increased during the October through December period by 73% ± 11% since 1975, and are correlated with rising summer temperatures. Together, these results imply increasing early winter respiration and net annual emission of CO 2 in Alaska, in response to climate warming. Our results provide evidence that the decadal-scale increase in the amplitude of the CO 2 seasonal cycle may be linked with increasing biogenic emissions in the Arctic, following the growing season. Early winter respiration was not well simulated by the Earth System Models used to forecast future carbon fluxes in recent climate assessments. Therefore, these assessments may underestimate the carbon release from Arctic soils in response to a warming climate.

Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra

NASA Astrophysics Data System (ADS)

Commane, Róisín; Lindaas, Jakob; Benmergui, Joshua; Luus, Kristina A.; Chang, Rachel Y.-W.; Daube, Bruce C.; Euskirchen, Eugénie S.; Henderson, John M.; Karion, Anna; Miller, John B.; Miller, Scot M.; Parazoo, Nicholas C.; Randerson, James T.; Sweeney, Colm; Tans, Pieter; Thoning, Kirk; Veraverbeke, Sander; Miller, Charles E.; Wofsy, Steven C.

2017-05-01

High-latitude ecosystems have the capacity to release large amounts of carbon dioxide (CO2) to the atmosphere in response to increasing temperatures, representing a potentially significant positive feedback within the climate system. Here, we combine aircraft and tower observations of atmospheric CO2 with remote sensing data and meteorological products to derive temporally and spatially resolved year-round CO2 fluxes across Alaska during 2012-2014. We find that tundra ecosystems were a net source of CO2 to the atmosphere annually, with especially high rates of respiration during early winter (October through December). Long-term records at Barrow, AK, suggest that CO2 emission rates from North Slope tundra have increased during the October through December period by 73% ± 11% since 1975, and are correlated with rising summer temperatures. Together, these results imply increasing early winter respiration and net annual emission of CO2 in Alaska, in response to climate warming. Our results provide evidence that the decadal-scale increase in the amplitude of the CO2 seasonal cycle may be linked with increasing biogenic emissions in the Arctic, following the growing season. Early winter respiration was not well simulated by the Earth System Models used to forecast future carbon fluxes in recent climate assessments. Therefore, these assessments may underestimate the carbon release from Arctic soils in response to a warming climate.

A new offshore transport mechanism for shoreline-released tracer induced by transient rip currents and stratification

NASA Astrophysics Data System (ADS)

Kumar, Nirnimesh; Feddersen, Falk

2017-03-01

Offshore transport from the shoreline across the inner shelf of early-stage larvae and pathogens is poorly understood yet is critical for understanding larval fate and dilution of polluted shoreline water. With a novel coupling of a transient rip current (TRC) generating surf zone model and an ocean circulation model, we show that transient rip currents ejected onto a stratified inner shelf induce a new, previously unconsidered offshore transport pathway. For incident waves and stratification typical for Southern California in the fall, this mechanism subducts surf zone-origin tracers and transports them at least 800 m offshore at 1.2 km/d analogous to subduction at ocean fronts. This mechanism requires both TRCs and stratification. As TRCs are ubiquitous and the inner shelf is often stratified, this mechanism may have an important role in exporting early-stage larvae, pathogens, or other tracers onto the shelf.

Transcranial direct current stimulation transiently increases the blood-brain barrier solute permeability in vivo

NASA Astrophysics Data System (ADS)

Shin, Da Wi; Khadka, Niranjan; Fan, Jie; Bikson, Marom; Fu, Bingmei M.

2016-03-01

Transcranial Direct Current Stimulation (tDCS) is a non-invasive electrical stimulation technique investigated for a broad range of medical and performance indications. Whereas prior studies have focused exclusively on direct neuron polarization, our hypothesis is that tDCS directly modulates endothelial cells leading to transient changes in blood-brain-barrier (BBB) permeability (P) that are highly meaningful for neuronal activity. For this, we developed state-of-the-art imaging and animal models to quantify P to various sized solutes after tDCS treatment. tDCS was administered using a constant current stimulator to deliver a 1mA current to the right frontal cortex of rat (approximately 2 mm posterior to bregma and 2 mm right to sagittal suture) to obtain similar physiological outcome as that in the human tDCS application studies. Sodium fluorescein (MW=376), or FITC-dextrans (20K and 70K), in 1% BSA mammalian Ringer was injected into the rat (SD, 250-300g) cerebral circulation via the ipsilateral carotid artery by a syringe pump at a constant rate of ~3 ml/min. To determine P, multiphoton microscopy with 800-850 nm wavelength laser was applied to take the images from the region of interest (ROI) with proper microvessels, which are 100-200 micron below the pia mater. It shows that the relative increase in P is about 8-fold for small solute, sodium fluorescein, ~35-fold for both intermediate sized (Dex-20k) and large (Dex-70k) solutes, 10 min after 20 min tDCS pretreatment. All of the increased permeability returns to the control after 20 min post treatment. The results confirmed our hypothesis.

Human mesenchymal stromal cells transiently increase cytokine production by activated T cells before suppressing T-cell proliferation: effect of interferon-γ and tumor necrosis factor-α stimulation.

PubMed

Cuerquis, Jessica; Romieu-Mourez, Raphaëlle; François, Moïra; Routy, Jean-Pierre; Young, Yoon Kow; Zhao, Jing; Eliopoulos, Nicoletta

2014-02-01

Mesenchymal stromal cells (MSCs) suppress T-cell proliferation, especially after activation with inflammatory cytokines. We compared the dynamic action of unprimed and interferon (IFN)-γ plus tumor necrosis factor (TNF)-α-pretreated human bone marrow-derived MSCs on resting or activated T cells. MSCs were co-cultured with allogeneic peripheral blood mononuclear cells (PBMCs) at high MSC-to-PBMC ratios in the absence or presence of concomitant CD3/CD28-induced T-cell activation. The kinetic effects of MSCs on cytokine production and T-cell proliferation, cell cycle and apoptosis were assessed. Unprimed MSCs increased the early production of IFN-γ and interleukin (IL)-2 by CD3/CD28-activated PBMCs before suppressing T-cell proliferation. In non-activated PBMC co-cultures, low levels of IL-2 and IL-10 synthesis were observed with MSCs in addition to low levels of CD69 expression by T cells and no T-cell proliferation. MSCs also decreased apoptosis in resting and activated T cells and inhibited the transition of these cells into the sub-G0/G1 and the S phases. With inhibition of indoleamine 2,3 dioxygenase, MSCs increased CD3/CD28-induced T-cell proliferation. After priming with IFN-γ plus TNF-α, MSCs were less potent at increasing cytokine production by CD3/CD28-activated PBMCs and more effective at inhibiting T-cell proliferation but had preserved anti-apoptotic functions. Unprimed MSCs induce a transient increase in IFN-γ and IL-2 synthesis by activated T cells. Pre-treatment of MSCs with IFN-γ plus TNF-α may increase their effectiveness and safety in vivo. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Transient Co-Expression of Post-Transcriptional Gene Silencing Suppressors for Increased in Planta Expression of a Recombinant Anthrax Receptor Fusion Protein

PubMed Central

Arzola, Lucas; Chen, Junxing; Rattanaporn, Kittipong; Maclean, James M.; McDonald, Karen A.

2011-01-01

Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin), CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA) domain of human capillary morphogenesis 2 (CMG2), an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG). We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS): p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI), with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI. PMID:21954339

Transient co-expression of post-transcriptional gene silencing suppressors for increased in planta expression of a recombinant anthrax receptor fusion protein.

PubMed

Arzola, Lucas; Chen, Junxing; Rattanaporn, Kittipong; Maclean, James M; McDonald, Karen A

2011-01-01

Potential epidemics of infectious diseases and the constant threat of bioterrorism demand rapid, scalable, and cost-efficient manufacturing of therapeutic proteins. Molecular farming of tobacco plants provides an alternative for the recombinant production of therapeutics. We have developed a transient production platform that uses Agrobacterium infiltration of Nicotiana benthamiana plants to express a novel anthrax receptor decoy protein (immunoadhesin), CMG2-Fc. This chimeric fusion protein, designed to protect against the deadly anthrax toxins, is composed of the von Willebrand factor A (VWA) domain of human capillary morphogenesis 2 (CMG2), an effective anthrax toxin receptor, and the Fc region of human immunoglobulin G (IgG). We evaluated, in N. benthamiana intact plants and detached leaves, the expression of CMG2-Fc under the control of the constitutive CaMV 35S promoter, and the co-expression of CMG2-Fc with nine different viral suppressors of post-transcriptional gene silencing (PTGS): p1, p10, p19, p21, p24, p25, p38, 2b, and HCPro. Overall, transient CMG2-Fc expression was higher on intact plants than detached leaves. Maximum expression was observed with p1 co-expression at 3.5 days post-infiltration (DPI), with a level of 0.56 g CMG2-Fc per kg of leaf fresh weight and 1.5% of the total soluble protein, a ten-fold increase in expression when compared to absence of suppression. Co-expression with the p25 PTGS suppressor also significantly increased the CMG2-Fc expression level after just 3.5 DPI.

Thyrotoxic periodic paralysis associated with transient thyrotoxicosis due to painless thyroiditis.

PubMed

Oh, Sang Bo; Ahn, Jinhee; Oh, Min Young; Choi, Bo Gwang; Kang, Ji Hyun; Jeon, Yun Kyung; Kim, Sang Soo; Kim, Bo Hyun; Kim, Yong Ki; Kim, In Joo

2012-07-01

Thyrotoxic periodic paralysis (TPP) is a rare manifestation of hyperthyroidism characterized by muscle weakness and hypokalemia. All ethnicities can be affected, but TPP typically presents in men of Asian descent. The most common cause of TPP in thyrotoxicosis is Graves' disease. However, TPP can occur with any form of thyrotoxicosis. Up to our knowledge, very few cases ever reported the relationship between TPP and painless thyroiditis. We herein report a 25-yr-old Korean man who suffered from flaccid paralysis of the lower extremities and numbness of hands. The patient was subsequently diagnosed as having TPP associated with transient thyrotoxicosis due to painless thyroiditis. The paralytic attack did not recur after improving the thyroid function. Therefore, it is necessary that early diagnosis of TPP due to transient thyrotoxicosis is made to administer definite treatment and prevent recurrent paralysis.

Thyrotoxic Periodic Paralysis Associated with Transient Thyrotoxicosis Due to Painless Thyroiditis

PubMed Central

Oh, Sang Bo; Ahn, Jinhee; Oh, Min Young; Choi, Bo Gwang; Kang, Ji Hyun; Jeon, Yun Kyung; Kim, Sang Soo; Kim, Yong Ki; Kim, In Joo

2012-01-01

Thyrotoxic periodic paralysis (TPP) is a rare manifestation of hyperthyroidism characterized by muscle weakness and hypokalemia. All ethnicities can be affected, but TPP typically presents in men of Asian descent. The most common cause of TPP in thyrotoxicosis is Graves' disease. However, TPP can occur with any form of thyrotoxicosis. Up to our knowledge, very few cases ever reported the relationship between TPP and painless thyroiditis. We herein report a 25-yr-old Korean man who suffered from flaccid paralysis of the lower extremities and numbness of hands. The patient was subsequently diagnosed as having TPP associated with transient thyrotoxicosis due to painless thyroiditis. The paralytic attack did not recur after improving the thyroid function. Therefore, it is necessary that early diagnosis of TPP due to transient thyrotoxicosis is made to administer definite treatment and prevent recurrent paralysis. PMID:22787383

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.

Interferon-τ increases BoLA-I for implantation during early pregnancy in dairy cows.

PubMed

Zhu, Zhe; Li, Binbin; Wu, Yue; Wang, Xiao; Deng, GanZhen

2017-11-10

Interferon-τ (IFN-τ) signals pregnancy recognition in ruminants. We investigated the effects of IFN-τ produced by embryo trophoblastic cells (ETCs) on expression of bovine leukocyte antigen-I (BoLA-I), a bovine analogue of human MHC-I, in endometrial luminal epithelial cells (EECs) during early pregnancy in dairy cows. Expression of IFN-τ and BoLA-I was increased in endometrial tissues during early pregnancy. Expression of the anti-inflammatory cytokine IL-10 was increased in endometrial tissues, while expression of the pro-inflammatory cytokine IL-6 was decreased, indicating immunosuppression. Progesterone increased IFN-τ expression in EECs. IFN-τ increased p-STAT1 and p-STAT3 levels in EECs, but reduced TRAF3 levels. In addition, IFN-τ increased expression of BoLA-I and IL-10, but decreased expression of IL-6 in EECs. These results indicate that IFN-τ enables stable implantation in dairy cows by increasing expression of BoLA-I, and by immunosuppression mediated by increased IL-10 and decreased IL-6 expression.

Interferon-τ increases BoLA-I for implantation during early pregnancy in dairy cows

PubMed Central

Zhu, Zhe; Li, Binbin; Wu, Yue; Wang, Xiao; Deng, GanZhen

2017-01-01

Interferon-τ (IFN-τ) signals pregnancy recognition in ruminants. We investigated the effects of IFN-τ produced by embryo trophoblastic cells (ETCs) on expression of bovine leukocyte antigen-I (BoLA-I), a bovine analogue of human MHC-I, in endometrial luminal epithelial cells (EECs) during early pregnancy in dairy cows. Expression of IFN-τ and BoLA-I was increased in endometrial tissues during early pregnancy. Expression of the anti-inflammatory cytokine IL-10 was increased in endometrial tissues, while expression of the pro-inflammatory cytokine IL-6 was decreased, indicating immunosuppression. Progesterone increased IFN-τ expression in EECs. IFN-τ increased p-STAT1 and p-STAT3 levels in EECs, but reduced TRAF3 levels. In addition, IFN-τ increased expression of BoLA-I and IL-10, but decreased expression of IL-6 in EECs. These results indicate that IFN-τ enables stable implantation in dairy cows by increasing expression of BoLA-I, and by immunosuppression mediated by increased IL-10 and decreased IL-6 expression. PMID:29221114

Improved analysis of transient temperature data from permanent down-hole gauges (PDGs)

NASA Astrophysics Data System (ADS)

Zhang, Yiqun; Zheng, Shiyi; Wang, Qi

2017-08-01

With the installation of permanent down-hole gauges (PDGs) during oil field development, large volumes of high resolution and continuous down-hole information are obtainable. The interpretation of these real-time temperature and pressure data can optimize well performance, provide information about the reservoir and continuously calibrate the reservoir model. Although the dynamic temperature data have been interpreted in practice to predict flow profiling and provide characteristic information of the reservoir, almost all of the approaches rely on established non-isothermal models which depend on thermodynamic parameters. Another problem comes from the temperature transient analysis (TTA), which is underutilized compared with pressure transient analysis (PTA). In this study, several model-independent methods of TTA were performed. The entire set of PDG data consists of many flow events. By utilizing the wavelet transform, the exact points of flow-rate changes can be located. The flow regime changes, for example, from early time linear flow to later time pseudo-radial flow, among every transient period with constant flow-rate. For the early time region (ETR) that is caused by flow-rate change operations, the TTA, along with the PTA can greatly reduce the uncertainties in flow regime diagnosis. Then, the temperature variations during ETR were examined to infer the true reservoir temperature history, and the relationships between the wavelet detailed coefficients and the flow-rate changes were analysed. For the scenarios with constant reservoir-well parameters, the detailed flow-rate history can be generated by calculating the coefficient of relationship in advance. For later times, the flow regime changes to pseudo-radial flow. An analytical solution was introduced to describe the sand-face temperature. The formation parameters, such as permeability and skin factor, were estimated with the previously calculated flow-rate. It is necessary to analyse temperature

Two-Flux Method for Transient Radiative Transfer in a Semitransparent Layer

NASA Technical Reports Server (NTRS)

Siegel, Robert

1996-01-01

The two-flux method was used to obtain transient solutions for a plane layer including internal reflections and scattering. The layer was initially at uniform temperature, and was heated or cooled by external radiation and convection. The two-flux equations were examined as a means for evaluating the radiative flux gradient in the transient energy equation. Comparisons of transient temperature distributions using the two-flux method were made with results where the radiative flux gradient was evaluated from the exact radiative transfer equations. Good agreement was obtained for optical thicknesses from 0.5 to 5 and for refractive indices of 1 and 2. Illustrative results obtained with the two-flux method demonstrate the effect of isotropic scattering coupled with changing the refractive index. For small absorption with large scattering the maximum layer temperature is increased when the refractive index is increased. For larger absorption the effect is opposite, and the maximum temperature decreases with increased refractive index .

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.

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.

Transient solute transport with sorption in Poiseuille flow

NASA Astrophysics Data System (ADS)

Hesse, M. A.; Zhang, L.; Wang, M.

2016-12-01

Sorption onto the wall has been observed to both increase [Lungu and Moffatt, 1982] and decrease the average solute transport velocity [Golay, 1958], relative to the mean flow velocity. Similarly, opposite conclusion have been reached for the effect of sorption on dispersion. In this work, we study transient solute transport in Poiseuille flow with sorptive boundary and initial transversely uniform distribution (linear release) to reconcile the two different views on solute transport (figure 1) with sorption. Two-dimensional simulations in figure 2 show that there is a transition from fast transport dominated by a fast-moving pulse in the middle of the channel at early times, to slow transport at late times once desorption from the walls becomes important. A set of series solutions for zeroth, first and second longitudinal moment have been derived and we show that the zeroth-order term in the solution corresponds to the slow transport in the late regime, while the first-order term corresponds to the fast transport in the early regime (figure 3). Based on the analytical solution, the time scales for early regime and late regimes of both the velocity and the dispersion coefficient have been determined for an equilibrium sorption model and a kinetic linear sorption model. Furthermore, we give approximated analytical solution when both adsorption and desorption are slow. References M.J.E. Golay. Theory of chromatography in open and coated tubular columns iwth round and rectangular cross-sections. In D.H.Desty, editor, Gas Chromatography, pages 36-53, New York, 1958. Academic Press Inc. E.M. Lungu and H.K. Moffatt. the effect of wall conductance on heat diffusion in duct flow. Journal of Engineering Mathematics, 1692 ;121-136, 1982.

Thermal transient anemometer

DOEpatents

Bailey, James L.; Vresk, Josip

1989-01-01

A thermal transient anemometer having a thermocouple probe which is utilized to measure the change in temperature over a period of time to provide a measure of fluid flow velocity. The thermocouple probe is located in the fluid flow path and pulsed to heat or cool the probe. The cooling of the heated probe or the heating of the cooled probe from the fluid flow over a period of time is measured to determine the fluid flow velocity. The probe is desired to be locally heated near the tip to increase the efficiency of devices incorporating the probe.

Thermal transient anemometer

DOEpatents

Bailey, J.L.; Vresk, J.

1989-07-18

A thermal transient anemometer is disclosed having a thermocouple probe which is utilized to measure the change in temperature over a period of time to provide a measure of fluid flow velocity. The thermocouple probe is located in the fluid flow path and pulsed to heat or cool the probe. The cooling of the heated probe or the heating of the cooled probe from the fluid flow over a period of time is measured to determine the fluid flow velocity. The probe is desired to be locally heated near the tip to increase the efficiency of devices incorporating the probe. 12 figs.

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.

Migratory phase of Litomosoides sigmodontis filarial infective larvae is associated with pathology and transient increase of S100A9 expressing neutrophils in the lung

PubMed Central

Pionnier, Nicolas; Vallarino-Lhermitte, Nathaly; Lefoulon, Emilie; Nieguitsila, Adélaïde; Specht, Sabine; Carlin, Leo M.; Martin, Coralie

2017-01-01

Filarial infections are tropical diseases caused by nematodes of the Onchocercidae family such as Mansonella perstans. The infective larvae (L3) are transmitted into the skin of vertebrate hosts by blood-feeding vectors. Many filarial species settle in the serous cavities including M. perstans in humans and L. sigmodontis, a well-established model of filariasis in mice. L. sigmodontis L3 migrate to the pleural cavity where they moult into L4 around day 9 and into male and female adult worms around day 30. Little is known of the early phase of the parasite life cycle, after the L3 is inoculated in the dermis by the vector and enters the afferent lymphatic vessels and before the moulting processes in the pleural cavity. Here we reveal a pulmonary phase associated with lung damage characterized by haemorrhages and granulomas suggesting L3 reach the lung via pulmonary capillaries and damage the endothelium and parenchyma by crossing them to enter the pleural cavity. This study also provides evidence for a transient inflammation in the lung characterized by a very early recruitment of neutrophils associated with high expression levels of S100A8 and S100A9 proteins. PMID:28486498

Development of an Efficient Identifier for Nuclear Power Plant Transients Based on Latest Advances of Error Back-Propagation Learning Algorithm

NASA Astrophysics Data System (ADS)

Moshkbar-Bakhshayesh, Khalil; Ghofrani, Mohammad B.

2014-02-01

This study aims to improve the performance of nuclear power plants (NPPs) transients training and identification using the latest advances of error back-propagation (EBP) learning algorithm. To this end, elements of EBP, including input data, initial weights, learning rate, cost function, activation function, and weights updating procedure are investigated and an efficient neural network is developed. Usefulness of modular networks is also examined and appropriate identifiers, one for each transient, are employed. Furthermore, the effect of transient type on transient identifier performance is illustrated. Subsequently, the developed transient identifier is applied to Bushehr nuclear power plant (BNPP). Seven types of the plant events are probed to analyze the ability of the proposed identifier. The results reveal that identification occurs very early with only five plant variables, whilst in the previous studies a larger number of variables (typically 15 to 20) were required. Modular networks facilitated identification due to its sole dependency on the sign of each network output signal. Fast training of input patterns, extendibility for identification of more transients and reduction of false identification are other advantageous of the proposed identifier. Finally, the balance between the correct answer to the trained transients (memorization) and reasonable response to the test transients (generalization) is improved, meeting one of the primary design criteria of identifiers.

Transient-Switch-Signal Suppressor

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Circuit delays transmission of switch-opening or switch-closing signal until after preset suppression time. Used to prevent transmission of undesired momentary switch signal. Basic mode of operation simple. Beginning of switch signal initiates timing sequence. If switch signal persists after preset suppression time, circuit transmits switch signal to external circuitry. If switch signal no longer present after suppression time, switch signal deemed transient, and circuit does not pass signal on to external circuitry, as though no transient switch signal. Suppression time preset at value large enough to allow for damping of underlying pressure wave or other mechanical transient.

Mitochondrial Epigenetic Changes Link to Increased Diabetes Risk and Early-Stage Prediabetes Indicator

PubMed Central

Zheng, Louise D.; Linarelli, Leah E.; Brooke, Joseph; Smith, Cayleen; Wall, Sarah S.; Greenawald, Mark H.; Seidel, Richard W.; Estabrooks, Paul A.; Almeida, Fabio A.; Cheng, Zhiyong

2016-01-01

Type 2 diabetes (T2D) is characterized by mitochondrial derangement and oxidative stress. With no known cure for T2D, it is critical to identify mitochondrial biomarkers for early diagnosis of prediabetes and disease prevention. Here we examined 87 participants on the diagnosis power of fasting glucose (FG) and hemoglobin A1c levels and investigated their interactions with mitochondrial DNA methylation. FG and A1c led to discordant diagnostic results irrespective of increased body mass index (BMI), underscoring the need of new biomarkers for prediabetes diagnosis. Mitochondrial DNA methylation levels were not correlated with late-stage (impaired FG or A1c) but significantly with early-stage (impaired insulin sensitivity) events. Quartiles of BMI suggested that mitochondrial DNA methylation increased drastically from Q1 (20 < BMI < 24.9, lean) to Q2 (30 < BMI < 34.9, obese), but marginally from Q2 to Q3 (35 < BMI < 39.9, severely obese) and from Q3 to Q4 (BMI > 40, morbidly obese). A significant change was also observed from Q1 to Q2 in HOMA insulin sensitivity but not in A1c or FG. Thus, mitochondrial epigenetic changes link to increased diabetes risk and the indicator of early-stage prediabetes. Further larger-scale studies to examine the potential of mitochondrial epigenetic marker in prediabetes diagnosis will be of critical importance for T2D prevention. PMID:27298712

Features of postfailure fuel behavior in transient overpower and transient undercooled/overpower tests in the transient reactor test facility

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

Doerner, R.C.; Bauer, T.H.; Morman, J.A.

Prototypic oxide fuel was subjected to simulated, fast reactor severe accident conditions in a series of in-pile tests in the Transient Reactor Test Facility reactor. Seven experiments were performed on fresh and previously irradiated oxide fuel pins under transient overpower and transient undercooled. overpower accident conditions. For each of the tests, fuel motions were observed by the hodoscope. Hodoscope data are correlated with coolant flow, pressure, and temperature data recorded by the loop instrumentation. Data were analyzed from the onset of initial failure to a final mass distribution at the end of the test. In this paper results of thesemore » analyses are compared to pre- and posttest accident calculations and to posttest metallographic accident calculations and to posttest metallographic examinations and computed tomographic reconstructions from neutron radiographs.« less

Investigations of an Environmentally Induced Long Duration Hall Thruster Start Transient (PREPRINT)

DTIC Science & Technology

2006-02-06

Hall thruster start transient is produced by exposure of the thruster to ambient laboratory atmosphere. This behavior was first observed during operation of a cluster of four 200 W BHT-200 Hall effect thrusters where large anode discharge fluctuations, visible as increased anode current and a diffuse plume structure, occurred in an apparently random manner. During operation of a single thruster, the start transient appears as a quickly rising and later smoothly decaying elevated anode current with a diffuse plume that persists for less than 500 seconds. The start transient

Transient high glycaemic intake in the last trimester of pregnancy increases offspring birthweight and postnatal growth rate in sheep: a randomised control trial

PubMed Central

Smith, NA; McAuliffe, FM; Quinn, K; Lonergan, P; Evans, ACO

2009-01-01

Objective Investigate the effect of transient hyperglycemic intake (analogous to snacking on high glycaemic foods) in the third trimester of pregnancy on offspring birthweight and subsequent growth in sheep. Design Randomised trial. Setting University research farm. Sample Third trimester pregnant ewes. Methods Ewes were blocked on weight, age and litter size and were randomly assigned to receive oral administration of 100 ml of propylene glycol (PG; n = 51) or 100 ml of water (control, C; n = 53) twice/day. Twice during treatment, 12 ewes from each group were selected and blood samples collected to determine the glucose and insulin response to treatment. Main outcome measures At birth, blood was collected from the lambs, their body dimensions measured and body weights recorded at 0, 6 and 12 weeks of age after which lambs were slaughtered when they reached 40 kg live weight. Results Administration of PG elevated (P < 0.05) plasma glucose and insulin concentrations for 2 hours post administration compared with control ewes. Lambs (C: n = 80; PG: n = 70) born to ewes fed high glycaemic meals had higher birthweights (C: 5.01 ± 0.18 kg; PG: 5.27 ± 0.22 kg, P = 0.032), plasma glucose concentrations (P = 0.001) and ponderal index (weight/height3, P = 0.043) and reached a similar (P > 0.05) slaughter carcass weight (C: 20.0 ± 0.51 kg; PG: 20.6 ± 0.55 kg) at an earlier age (PG: 166.0 ± 13.2; C: 183.4 ± 13.8 days, P = 0.039) compared with control lambs. Conclusions Transient high glycaemic intakes in the third trimester of pregnancy resulted in heavier offspring at birth that had faster growth rates in early postnatal life. This animal model is relevant for studying the relationship between maternal diet, fetal size and the risk of childhood obesity. PMID:19385960

Transient Diabetes Insipidus Following Cardiopulmonary Bypass.

PubMed

Ekim, Meral; Ekim, Hasan; Yilmaz, Yunus Keser; Bolat, Ali

2015-04-01

Diabetes insipidus (DI) results from inadequate output of Antidiuretic Hormone (ADH) from the pituitary gland (central DI) or the inability of the kidney tubules to respond to ADH (nephrogenic DI). ADH is an octapeptide produced in the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior lobe of the pituitary gland. Cardiopulmonary Bypass (CPB) has been shown to cause a six-fold increased circulating ADH levels 12 hours after surgery. However, in some cases, ADH release may be transiently suppressed due to cardioplegia (cardiac standstill) or CPB leading to DI. We present the postoperative course of a 60-year-old man who developed transient DI after CPB. He was successfully treated by applying nasal desmopressin therapy. Relevant biochemical parameters should be monitored closely in patients who produce excessive urine after open heart surgery.

Large-Scale Impact Cratering and Early Earth Evolution

NASA Technical Reports Server (NTRS)

Grieve, R. A. F.; Cintala, M. J.

1997-01-01

The surface of the Moon attests to the importance of large-scale impact in its early crustal evolution. Previous models of the effects of a massive bombardment on terrestrial crustal evolution have relied on analogies with the Moon, with allowances for the presence of water and a thinner lithosphere. It is now apparent that strict lunar-terrestrial analogies are incorrect because of the "differential scaling" of crater dimensions and melt volumes with event size and planetary gravity. Impact melt volumes and "ancient cavity dimensions for specific impacts were modeled according to previous procedures. In the terrestrial case, the melt volume (V(sub m)) exceeds that of the transient cavity (V(sub tc)) at diameters > or = 400 km. This condition is reached on the Moon only with transient cavity diameters > or = 3000 km, equivalent to whole Moon melting. The melt volumes in these large impact events are minimum estimates, since, at these sizes, the higher temperature of the target rocks at depth will increase melt production. Using the modification-scaling relation of Croft, a transient cavity diameter of about 400 km in the terrestrial environment corresponds to an expected final impact "basin" diameter of about 900 km. Such a "basin" would be comparable in dimensions to the lunar basin Orientale. This 900-km "basin" on the early Earth, however, would not have had the appearance of Orientale. It would have been essentially a melt pool, and, morphologically, would have had more in common with the palimpsests structures on Callisto and Ganymede. With the terrestrial equivalents to the large multiring basins of the Moon being manifested as muted palimpsest-like structures filled with impact melt, it is unlikely they played a role in establishing the freeboard on the early Earth. The composition of the massive impact melt sheets (> 10 (exp 7) cu km) produced in "basin-forming" events on the early Earth would have most likely ranged from basaltic to more mafic for the

Protective Effects of Enriched Environment Against Transient Cerebral Ischemia-Induced Impairment of Passive Avoidance Memory and Long-Term Potentiation in Rats

PubMed Central

Ahmadalipour, Ali; Sadeghzadeh, Jafar; Samaei, Seyed Afshin; Rashidy-Pour, Ali

2017-01-01

Introduction: Enriched Environment (EE), a complex novel environment, has been demonstrated to improve synaptic plasticity in both injured and intact animals. The present study investigated the capacity of an early environmental intervention to normalize the impairment of passive avoidance memory and Long-Term Potentiation (LTP) induced by transient bilateral common carotid artery occlusion (2-vessel occlusion, 2VO) in rats. Methods: After weaning, young Wistar rats (22 days old) were housed in EE or Standard Environment (SE) for 40 days. Transient (30-min) incomplete forebrain ischemia was induced 4 days before the passive avoidance memory test and LTP induction. Results: The transient forebrain ischemia led to impairment of passive avoidance memory and LTP induction in the Perforant Path-Dentate Gyrus (PP-DG) synapses. Interestingly, housing and growing in EE prior to 2VO was found to significantly reverse 2VO-induced cognitive and LTP impairments. Conclusion: Our results suggest that early housing and growing in EE exhibits therapeutic potential to normalize cognitive and LTP abnormalities induced by 2VO ischemic model in rats.

Functional Imaging of Sleep Vertex Sharp Transients

PubMed Central

Stern, John M.; Caporro, Matteo; Haneef, Zulfi; Yeh, Hsiang J.; Buttinelli, Carla; Lenartowicz, Agatha; Mumford, Jeanette A.; Parvizi, Josef; Poldrack, Russell A.

2011-01-01

Objective The vertex sharp transient (VST) is an electroencephalographic (EEG) discharge that is an early marker of non-REM sleep. It has been recognized since the beginning of sleep physiology research, but its source and function remain mostly unexplained. We investigated VST generation using functional MRI (fMRI). Methods Simultaneous EEG and fMRI were recorded from 7 individuals in drowsiness and light sleep. VST occurrences on EEG were modeled with fMRI using an impulse function convolved with a hemodynamic response function to identify cerebral regions correlating to the VSTs. A resulting statistical image was thresholded at Z>2.3. Results Two hundred VSTs were identified. Significantly increased signal was present bilaterally in medial central, lateral precentral, posterior superior temporal, and medial occipital cortex. No regions of decreased signal were present. Conclusion The regions are consistent with electrophysiologic evidence from animal models and functional imaging of human sleep, but the results are specific to VSTs. The regions principally encompass the primary sensorimotor cortical regions for vision, hearing, and touch. Significance The results depict a network comprising the presumed VST generator and its associated regions. The associated regions functional similarity for primary sensation suggests a role for VSTs in sensory experience during sleep. PMID:21310653

Functional imaging of sleep vertex sharp transients.

PubMed

Stern, John M; Caporro, Matteo; Haneef, Zulfi; Yeh, Hsiang J; Buttinelli, Carla; Lenartowicz, Agatha; Mumford, Jeanette A; Parvizi, Josef; Poldrack, Russell A

2011-07-01

The vertex sharp transient (VST) is an electroencephalographic (EEG) discharge that is an early marker of non-REM sleep. It has been recognized since the beginning of sleep physiology research, but its source and function remain mostly unexplained. We investigated VST generation using functional MRI (fMRI). Simultaneous EEG and fMRI were recorded from seven individuals in drowsiness and light sleep. VST occurrences on EEG were modeled with fMRI using an impulse function convolved with a hemodynamic response function to identify cerebral regions correlating to the VSTs. A resulting statistical image was thresholded at Z>2.3. Two hundred VSTs were identified. Significantly increased signal was present bilaterally in medial central, lateral precentral, posterior superior temporal, and medial occipital cortex. No regions of decreased signal were present. The regions are consistent with electrophysiologic evidence from animal models and functional imaging of human sleep, but the results are specific to VSTs. The regions principally encompass the primary sensorimotor cortical regions for vision, hearing, and touch. The results depict a network comprising the presumed VST generator and its associated regions. The associated regions functional similarity for primary sensation suggests a role for VSTs in sensory experience during sleep. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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.

Apparatus Characterizes Transient Voltages in Real Time

NASA Technical Reports Server (NTRS)

Medelius, Pedro

2005-01-01

The figure shows a prototype of a relatively inexpensive electronic monitoring apparatus that measures and records selected parameters of lightning-induced transient voltages on communication and power cables. The selected parameters, listed below, are those most relevant to the ability of lightning-induced transients to damage electronic equipment. This apparatus bridges a gap between some traditional transient-voltage recorders that record complete waveforms and other traditional transient-voltage recorders that record only peak values: By recording the most relevant parameters and only those parameters this apparatus yields more useful information than does a traditional peak-value (only) recorder while imposing much smaller data-storage and data-transmission burdens than does a traditional complete-waveform recorder. Also, relative to a complete-waveform recorder, this apparatus is more reliable and can be built at lower cost because it contains fewer electronic components. The transients generated by sources other than lightning tend to have frequency components well below 1 MHz. Most commercial transient recorders can detect and record such transients, but cannot respond rapidly enough for recording lightning-induced transient voltage peaks, which can rise from 10 to 90 percent of maximum amplitude in a fraction of a microsecond. Moreover, commercial transient recorders cannot rearm themselves rapidly enough to respond to the multiple transients that occur within milliseconds of each other on some lightning strikes. One transient recorder, designed for Kennedy Space Center earlier [ Fast Transient-Voltage Recorder (KSC- 11991), NASA Tech Briefs, Vol. 23, No. 10, page 6a (October 1999)], is capable of sampling transient voltages at peak values up to 50 V in four channels at a rate of 20 MHz. That recorder contains a trigger circuit that continuously compares the amplitudes of the signals on four channels to a preset triggering threshold. When a trigger signal

Early boost and slow consolidation in motor skill learning.

PubMed

Hotermans, Christophe; Peigneux, Philippe; Maertens de Noordhout, Alain; Moonen, Gustave; Maquet, Pierre

2006-01-01

Motorskill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as 5-30 min after training but no longer observed 4 h later. This early boost is predictive of the performance achieved 48 h later, suggesting its functional relevance for memory processes.

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.

The joy of transient chaos.

PubMed

Tél, Tamás

2015-09-01

We intend to show that transient chaos is a very appealing, but still not widely appreciated, subfield of nonlinear dynamics. Besides flashing its basic properties and giving a brief overview of the many applications, a few recent transient-chaos-related subjects are introduced in some detail. These include the dynamics of decision making, dispersion, and sedimentation of volcanic ash, doubly transient chaos of undriven autonomous mechanical systems, and a dynamical systems approach to energy absorption or explosion.

The ZTF Bright Transient Survey

NASA Astrophysics Data System (ADS)

Fremling, C.; Sharma, Y.; Kulkarni, S. R.; Miller, A. A.; Taggart, K.; Perley, D. A.; Gooba, A.

2018-06-01

As a supplement to the Zwicky Transient Facility (ZTF; ATel #11266) public alerts (ATel #11685) we plan to report (following ATel #11615) bright probable supernovae identified in the raw alert stream from the ZTF Northern Sky Survey ("Celestial Cinematography"; see Bellm & Kulkarni, 2017, Nature Astronomy 1, 71) to the Transient Name Server (https://wis-tns.weizmann.ac.il) on a daily basis; the ZTF Bright Transient Survey (BTS; see Kulkarni et al., 2018; arXiv:1710.04223).

Characterizing SI Engine Transient Fuel Consumption in ...

EPA Pesticide Factsheets

Examine typical transient engine operation encountered over the EPA's vehicle and engine testing drive cycles to characterize that transient fuel usage, and then describe the changes made to ALPHA to better model transient engine operation. To present an approach to capture dynamic fuel consumption during engine transients and then implement these identified characteristics in ALPHA.

Effects of geoduck (Panopea generosa) aquaculture on resident and transient macrofauna communities of Puget Sound, Washington, USA

USGS Publications Warehouse

Mcdonald, P. Sean; Galloway, Aaron W.E.; McPeek, Kathleen C.; VanBlaricom, Glenn R.

2015-01-01

In Washington state, commercial culture of geoducks (Panopea generosa) involves large-scale out-planting of juveniles to intertidal habitats, and installation of PVC tubes and netting to exclude predators and increase early survival. Structures associated with this nascent aquaculture method are examined to determine whether they affect patterns of use by resident and transient macrofauna. Results are summarized from regular surveys of aquaculture operations and reference beaches in 2009 to 2011 at three sites during three phases of culture: (1) pregear (-geoducks, -structure), (2) gear present (+geoducks, +structures), and (3) postgear (+geoducks, -structures). Resident macroinvertebrates (infauna and epifauna) were sampled monthly (in most cases) using coring methods at low tide during all three phases. Differences in community composition between culture plots and reference areas were examined with permutational analysis of variance and homogeneity of multivariate dispersion tests. Scuba and shoreline transect surveys were used to examine habitat use by transient fish and macroinvertebrates. Analysis of similarity and complementary nonmetric multidimensional scaling were used to compare differences between species functional groups and habitat type during different aquaculture phases. Results suggest that resident and transient macrofauna respond differently to structures associated with geoduck aquaculture. No consistent differences in the community of resident macrofauna were observed at culture plots or reference areas at the three sites during any year. Conversely, total abundance of transient fish and macroinvertebrates were more than two times greater at culture plots than reference areas when aquaculture structures were in place. Community composition differed (analysis of similarity) between culture and reference plots during the gear-present phase, but did not persist to the next farming stage (postgear). Habitat complexity associated with shellfish

Radon inhalation protects against transient global cerebral ischemic injury in gerbils.

PubMed

Kataoka, Takahiro; Etani, Reo; Takata, Yuji; Nishiyama, Yuichi; Kawabe, Atsushi; Kumashiro, Masayuki; Taguchi, Takehito; Yamaoka, Kiyonori

2014-10-01

Although brain disorders are not the main indication for radon therapy, our previous study suggested that radon inhalation therapy might mitigate brain disorders. In this study, we assessed whether radon inhalation protects against transient global cerebral ischemic injury in gerbils. Gerbils were treated with inhaled radon at a concentration of 2,000 Bq/m(3) for 24 h. After radon inhalation, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that transient global cerebral ischemia induced neuronal damage in hippocampal CA1, and the number of damaged neurons was significantly increased compared with control. However, radon treatment inhibited ischemic damage. Superoxide dismutase (SOD) activity in the radon-treated gerbil brain was significantly higher than that in sham-operated gerbils. These findings suggested that radon inhalation activates antioxidative function, especially SOD, thereby inhibiting transient global cerebral ischemic injury in gerbils.

Are Sunflower chlorotic mottle virus infection symptoms modulated by early increases in leaf sugar concentration?

PubMed

Rodríguez, Marianela; Taleisnik, Edith; Lenardon, Sergio; Lascano, Ramiro

2010-09-15

Symptom development in a susceptible sunflower line inoculated with Sunflower chlorotic mottle virus (SuCMoV) was followed in the second pair of leaves at different post-inoculation times: before symptom expression (BS), at early (ES) and late (LS) symptom expression. Sugar and starch increases and photoinhibition were observed as early effects BS, and were maintained or enhanced later on, however, chlorophyll loss was detected only at LS. Photoinhibition correlated with a drastic decrease in D1 protein level. The progress of infection was accompanied by decreasing levels of apoplastic reactive oxygen species (ROS). In infected leaves, higher antioxidant enzyme activities (superoxide dismutase, SOD; ascorbate peroxidase, APX; glutathione reductase, GR) were observed from BS. The purpose of this work was to evaluate whether the early increases in carbohydrate accumulation may participate in SuCMoV symptom expression. Similar effects on photoinhibition, apoplastic ROS generation and antioxidant activity were generated when healthy leaves were treated with sugars. These results suggest that photoinhibitory processes and lower apoplastic superoxide levels induced by SuCMoV infection may be modulated by sugar increases. Copyright 2010 Elsevier GmbH. All rights reserved.

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior.

PubMed

Lipscomb, Shannon T; Laurent, Heidemarie; Neiderhiser, Jenae M; Shaw, Daniel S; Natsuaki, Misaki N; Reiss, David; Leve, Leslie D

2014-01-01

The current study examined interactions among genetic influences and children's early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children.

Ultrafast triggered transient energy storage by atomic layer deposition into porous silicon for integrated transient electronics

NASA Astrophysics Data System (ADS)

Douglas, Anna; Muralidharan, Nitin; Carter, Rachel; Share, Keith; Pint, Cary L.

2016-03-01

Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics.Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics. Electronic supplementary information (ESI) available: (i) Experimental details for ALD and material fabrication, ellipsometry film thickness, preparation of gel electrolyte and separator, details for electrochemical measurements, HRTEM image of VOx coated porous silicon, Raman spectroscopy for VOx as-deposited as well as annealed in air for 1 hour at 450 °C, SEM and transient behavior dissolution tests of uniformly coated VOx on

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.

Leukocyte integrin activation mediates transient neutropenia after G-CSF administration

PubMed Central

Tuschong, Laura; Bauer, Thomas R.; Yau, Yu Ying; Leitman, Susan F.; Hickstein, Dennis D.

2011-01-01

After administration of granulocyte colony-stimulating factor (G-CSF), there is a marked, albeit transient, drop in circulating neutrophils. To determine the role of leukocyte integrins in this disappearance, a dog having canine leukocyte adhesion deficiency (CLAD) or CLAD dogs who had undergone gene correction either by matched littermate allogeneic transplant or autologous gene therapy were evaluated. Shortly after G-CSF administration, a dramatic, yet transient, neutropenia was observed in the control littermates. This neutropenia was not as marked in the CLAD dogs. In all instances, it was CD18+ neutrophils that preferentially egressed from the circulation. The association of CD18 with this rapid loss suggested leukocyte integrin activation after G-CSF administration. To determine the activation status of the integrin, a monoclonal antibody recognizing the activated α-subunit cation binding domain (mAb24) was used to evaluate human leukocytes after G-CSF administration. Mirroring the dramatic decrease in circulating neutrophil numbers, there was a dramatic and specific increase in the activation of the α-subunit after G-CSF expression on polymorphonuclear leukocytes. This activation, like the drop in neutrophil count, was transient. These results demonstrate that the leukocyte integrin on circulating neutrophils is transiently activated after G-CSF administration and mediates the transient neutropenia observed after G-CSF administration. PMID:21844566

Normal pregnancy is associated with an increase in thrombin generation from the very early stages of the first trimester.

PubMed

Bagot, C N; Leishman, E; Onyiaodike, C C; Jordan, F; Freeman, D J

2017-09-01

Pregnancy is a hypercoagulable state associated with an increased risk of venous thrombosis, which begins during the first trimester, but the exact time of onset is unknown. Thrombin generation, a laboratory marker of thrombosis risk, increases during normal pregnancy but it is unclear exactly how early this increase occurs. We assessed thrombin generation by Calibrated Automated Thrombography in women undergoing natural cycle in vitro fertilization, who subsequently gave birth at term following a normal pregnancy (n=22). Blood samples were taken just prior to conception and repeated five times during very early pregnancy, up to Day 59 estimated gestation. Mean Endogenous Thrombin Potential (ETP), peak thrombin generation and Velocity Index (VI) increased significantly from pre-pregnancy to Day 43 gestation (p=0.024-0.0004). This change persisted to Day 59 gestation. The mean of the percentage change from baseline, accounting for inter-individual variation, in ETP, peak thrombin and VI increased significantly from pre-pregnancy to Day 32 gestation (p=0.0351-<0.0001) with the mean increase from baseline persisting to Day 59 gestation. Thrombin generation increases significantly during the very early stages of normal pregnancy when compared to the pre-pregnancy state. The increased risk of venous thrombosis therefore likely begins very early in a woman's pregnancy, suggesting that women considered clinically to be at high thrombotic risk should start thromboprophylaxis as early as possible after a positive pregnancy test. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

Transient carrier dynamics in a Mott insulator with antiferromagnetic order

NASA Astrophysics Data System (ADS)

Iyoda, Eiki; Ishihara, Sumio

2014-03-01

We study transient dynamics of hole carriers injected into a Mott insulator with antiferromagnetic long-range order. This "dynamical hole doping" contrasts with chemical hole doping. The theoretical framework for the transient carrier dynamics is presented based on the two-dimensional t-J model. The time dependencies of the optical conductivity spectra, as well as the one-particle excitation spectra, are calculated based on the Keldysh Green's function formalism at zero temperature combined with the self-consistent Born approximation. In the early stage after dynamical hole doping, the Drude component appears, and then incoherent components originating from hole-magnon scattering start to grow. Fast oscillatory behavior owing to coherent magnon and slow relaxation dynamics are confirmed in the spectra. The time profiles are interpreted as doped bare holes being dressed by magnon clouds and relaxed into spin polaron quasiparticle states. The characteristic relaxation times for Drude and incoherent peaks strongly depend on the momentum of the dynamically doped hole and the exchange constant. Implications for recent pump-probe experiments are discussed.

Early versus delayed rehabilitation following arthroscopic rotator cuff repair: A systematic review.

PubMed

Gallagher, Brian P; Bishop, Meghan E; Tjoumakaris, Fotios P; Freedman, Kevin B

2015-05-01

Early passive range of motion (ROM) following arthroscopic cuff repair is thought to decrease postoperative stiffness and improve functionality. However, early aggressive rehabilitation may compromise repair integrity. Our purpose was to perform a systematic review to determine if there are differences between early and delayed rehabilitation after arthroscopic rotator cuff repair in terms of clinical outcomes and healing. We performed a literature search with the terms 'arthroscopic rotator cuff', 'immobilization', 'early', 'delayed', 'late', and 'rehabilitation' using PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Selection criteria included: level I/II evidence ≤ 6 months in duration, comparing early versus delayed rehabilitation following arthroscopic repair. Data regarding demographics, sample sizes, duration, cuff pathology, surgery, rehabilitation, functional outcomes, pain, ROM and anatomic assessment of healing were analyzed. PRIMSA criteria were followed. We identified six articles matching our criteria. Three reported significantly increased functional scores within the first 3-6 months with early rehabilitation compared to the delayed group, only one of which continued to observe a difference at a final follow-up of 15 months. Four articles showed improved ROM in the first 3-6 months post-operatively with early rehabilitation. One noted transient differences in pain scores. Only one study noted significant differences in ROM at final follow-up. No study reported any significant difference in rates of rotator cuff re-tear. However, two studies noted a trend towards increased re-tear with early rehabilitation that did not reach significance. This was more pronounced in studies including medium-large tears. Early rehabilitation after arthroscopic cuff repair is associated with some initial improvements in ROM and function. Ultimately, similar clinical and anatomical outcomes between groups existed at 1 year. While there was no

Early Childhood Stress and Child Age Predict Longitudinal Increases in Obesogenic Eating Among Low-Income Children.

PubMed

Miller, Alison L; Gearhardt, Ashley N; Retzloff, Lauren; Sturza, Julie; Kaciroti, Niko; Lumeng, Julie C

2018-01-31

To identify whether psychosocial stress exposure during early childhood predicts subsequent increased eating in the absence of hunger (EAH), emotional overeating, food responsiveness, and enjoyment of food. This was an observational longitudinal study. Among 207 low-income children (54.6% non-Hispanic white, 46.9% girls), early childhood stress exposure was measured by parent report and a stress exposure index calculated, with higher scores indicating more stress exposure. Eating behaviors were measured in early (mean, 4.3; standard deviation, 0.5 years) and middle (mean, 7.9; standard deviation, 0.7 years) childhood. Observed EAH was assessed by measuring kilocalories of palatable food the child consumed after a meal. Parents reported on child eating behaviors on the Child Eating Behavior Questionnaire. Child weight and height were measured and body mass index z score (BMIz) calculated. Multivariable linear regression, adjusting for child sex, race/ethnicity, and BMIz, was used to examine the association of stress exposure with rate of change per year in each child eating behavior. Early childhood stress exposure predicted yearly increases in EAH (β = 0.14; 95% confidence interval, 0.002, 0.27) and Emotional Overeating (β = 0.14; 95% confidence interval, 0.008, 0.27). Stress exposure was not associated with Food Responsiveness (trend for decreased Enjoyment of Food; β = -0.13; 95% confidence interval, 0.002, -0.26). All child obesogenic eating behaviors increased with age (P < .05). Early stress exposure predicted increases in child eating behaviors known to associate with overweight/obesity. Psychosocial stress may confer overweight/obesity risk through eating behavior pathways. Targeting eating behaviors may be an important prevention strategy for children exposed to stress. Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Antibiotic Exposure in Early Life Increases Risk of Childhood Obesity: A Systematic Review and Meta-Analysis

PubMed Central

Shao, Xiaoqing; Ding, Xiaolian; Wang, Bin; Li, Ling; An, Xiaofei; Yao, Qiuming; Song, Ronghua; Zhang, Jin-an

2017-01-01

A number of studies have previously assessed the impact of antibiotic exposure in early life on the risk of childhood obesity, but no systematic assessment is currently available. A systematic review and meta-analysis was performed to comprehensively and quantitatively elucidate the risk of childhood obesity caused by antibiotic exposure in early life. Literature search was performed in PubMed, Embase, and Web of Science. Random-effect meta-analysis was used to pool the statistical estimates. Fifteen cohort studies involving 445,880 participants were finally included, and all those studies were performed in developed countries. Antibiotic exposure in early life significantly increased risk of childhood overweight [relative risk (RR) = 1.23, 95% confidence interval (CI) 1.13–1.35, P < 0.001] and childhood obesity (RR = 1.21, 95% CI 1.13–1.30, P < 0.001). Antibiotic exposure in early life also significantly increased the z-score of childhood body mass index (mean difference: 0.07, 95% CI 0.05–0.09, P < 0.00001). Importantly, there was an obvious dose–response relationship between antibiotic exposure in early life and childhood adiposity, with a 7% increment in the risk of overweight (RR = 1.07, 95% CI 1.01–1.15, P = 0.03) and a 6% increment in the risk of obesity (RR = 1.06, 95% CI 1.02–1.09, P < 0.001) for each additional course of antibiotic exposure. In conclusion, antibiotic exposure in early life significantly increases risk of childhood obesity. Moreover, current analyses are mainly taken from developed countries, and therefore the impact of antibiotic exposure on risk of childhood obesity in vulnerable populations or developing countries still needs to be evaluated in future studies. PMID:28775712

Quantification of metabolically active transient storage (MATS) in two reaches with contrasting transient storage and ecosystem respiration

Treesearch

Alba Argerich; Roy Haggerty; Eugènia Martí; Francesc Sabater; Jay Zarnetske

2011-01-01

Water transient storage zones are hotspots for metabolic activity in streams although the contribution of different types of transient storage zones to the whole�]reach metabolic activity is difficult to quantify. In this study we present a method to measure the fraction of the transient storage that is metabolically active (MATS) in two consecutive reaches...

Rapid All-Sky Transient Discovery and Analysis with Evryscope

NASA Astrophysics Data System (ADS)

Corbett, Henry T.; Law, Nicholas; Fors, Octavi; Ratzloff, Jeff; Goeke, Erin; Howard, Ward S.

2018-01-01

The Evryscope is an array of 24 small telescopes on a common mount, capable of observing the entire visible sky down to g' ~ 16 with a two-minute cadence. Each exposure covers 8000 square degrees over 691 MPix and requires minimal readout time, providing 97% continuous coverage of the night sky. The system's large field of view and rapid cadence enable exploration of a previously inaccessible parameter space of bright and fast transients, including nearby microlensing events, supernovae, and kilonovae GW counterparts. The first instrument, located at CTIO in Chile, was deployed in mid-2015 and is currently in production creating multi-year light curves with percent-level precision. A second identical system is on track for deployment at Mount Laguna Observatory in California in early 2018. Once operational, the two sites will provide simultaneous two-color photometry over a 4000 square degree overlapping region accessible to both instruments, operating as a combined discovery and follow-up network for transient phenomena on all nearby stars and many nearby galaxies. I will present recent science results from the Evryscope and an overview of our data reduction pipeline.

Thalamic Amnesia Mimicking Transient Global Amnesia.

PubMed

Giannantoni, Nadia M; Lacidogna, Giordano; Broccolini, Aldobrando; Pilato, Fabio; Profice, Paolo; Morosetti, Roberta; Caliandro, Pietro; Gambassi, Giovanni; Della Marca, Giacomo; Frisullo, Giovanni

2015-06-01

Transient global amnesia is a benign syndrome and one of the most frequent discharges from the emergency department that can hardly be distinguished from other mimicking diseases. No consensus in the evaluation of transient global amnesia has yet been found in the emergency setting. We describe a 69-year-old woman who presented to our emergency department with an abrupt onset of anterograde amnesia, preceded by a similar amnesic episode misinterpreted as transient global amnesia. Neuroradiologic, neuropsychological, and neurophysiological evaluations supported the diagnosis of vascular thalamic amnesia. We report a patient who clinically fulfilled transient global amnesia's criteria and in whom nevertheless was disclosed a thalamic ischemic lesion on neuroimaging.This case report highlights the importance of performing neuroradiologic screening in the emergency department even when clinical history and physical findings are highly suggestive for transient global amnesia.

Transient Optical Sky survey

NASA Astrophysics Data System (ADS)

Hadjiyska, Elena Ivanova

2009-06-01

Optical transients have been studied in isolated cases, but never mapped into a comprehensive data base in the past. These events vary in duration and signature, yet they are united under the umbrella of time varying observables and represent a significant portion of the dynamical processes in the universe. The Transient Optical Sky Survey (TOSS) System is a dedicated, ground-based system of small optical telescopes, observing nightly at fixed Declination while gathering 90 sec exposures and thus creating a repeated partial map of the sky. Presented here is a brief overview of some of the signatures of transient events and a description of the TOSS system along with the data acquired during the 2008-2009 observing campaign, potentially producing over 100,000 light curves.

Neutronics and Transient Calculations for the Conversion of the Transient Reactor Rest Facility (TREAT)

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

Kontogeorgakos, Dimitrios C.; Connaway, Heather M.; Papadias, Dionissios D.

2015-01-01

The Transient Reactor Test Facility (TREAT) is a graphite-reflected, graphitemoderated, and air-cooled reactor fueled with 93.1% enriched UO2 particles dispersed in graphite, with a carbon-to-235U ratio of ~10000:1. TREAT was used to simulate accident conditions by subjecting fuel test samples placed at the center of the core to high energy transient pulses. The transient pulse production is based on the core’s selflimiting nature due to the negative reactivity feedback provided by the fuel graphite as the core temperature rises. The analysis of the conversion of TREAT to low enriched uranium (LEU) is currently underway. This paper presents the analytical methodsmore » used to calculate the transient performance of TREAT in terms of power pulse production and resulting peak core temperatures. The validation of the HEU neutronics TREAT model, the calculation of the temperature distribution and the temperature reactivity feedback as well as the number of fissions generated inside fuel test samples are discussed.« less

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.

Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

NASA Technical Reports Server (NTRS)

Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

2015-01-01

During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior

PubMed Central

Lipscomb, Shannon T.; Laurent, Heidemarie; Neiderhiser, Jenae M.; Shaw, Daniel S.; Natsuaki, Misaki N.; Reiss, David; Leve, Leslie D.

2014-01-01

The current study examined interactions among genetic influences and children’s early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children. PMID:25067867

Increasing Early Reading Skills in Young Signing Deaf Children Using Shared Book Reading: A Feasibility Study

ERIC Educational Resources Information Center

Andrews, Jean F.; Liu, Hsiu-Tan; Liu, Chun-Jung; Gentry, Mary Anne; Smith, Zanthia

2017-01-01

A feasibility study was conducted to test a storybook intervention to increase early reading skills of 25 young signing deaf children of ages 4-9 in grades K through third grade. The children had wide ranges of hearing losses, non-verbal IQs, and signing skills. All were at risk for developing early reading skills, reading below the first grade…

Transient Receptor Potential Vanilloid 4 Activation-Induced Increase in Glycine-Activated Current in Mouse Hippocampal Pyramidal Neurons.

PubMed

Qi, Mengwen; Wu, Chunfeng; Wang, Zhouqing; Zhou, Li; Men, Chen; Du, Yimei; Huang, Songming; Chen, Lei; Chen, Ling

2018-01-01

Glycine plays an important role in regulating hippocampal inhibitory/ excitatory neurotransmission through activating glycine receptors (GlyRs) and acting as a co-agonist of N-methyl-d-aspartate-type glutamate receptors. Activation of transient receptor potential vanilloid 4 (TRPV4) is reported to inhibit hippocampal A-type γ-aminobutyric acid receptor, a ligand-gated chloride ion channel. GlyRs are also ligand-gated chloride ion channels and this paper aimed to explore whether activation of TRPV4 could modulate GlyRs. Whole-cell patch clamp recording was employed to record glycine-activated current (IGly) and Western blot was conducted to assess GlyRs subunits protein expression. Application of TRPV4 agonist (GSK1016790A or 5,6-EET) increased IGly in mouse hippocampal CA1 pyramidal neurons. This action was blocked by specific antagonists of TRPV4 (RN-1734 or HC-067047) and GlyR (strychnine), indicating that activation of TRPV4 increases strychnine-sensitive GlyR function in mouse hippocampal pyramidal neurons. GSK1016790A-induced increase in IGly was significantly attenuated by protein kinase C (PKC) (BIM II or D-sphingosine) or calcium/calmodulin-dependent protein kinase II (CaMKII) (KN-62 or KN-93) antagonists but was unaffected by protein kinase A or protein tyrosine kinase antagonists. Finally, hippocampal protein levels of GlyR α1 α2, α3 and β subunits were not changed by treatment with GSK1016790A for 30 min or 1 h, but GlyR α2, α3 and β subunits protein levels increased in mice that were intracerebroventricularly (icv.) injected with GSK1016790A for 5 d. Activation of TRPV4 increases GlyR function and expression, and PKC and CaMKII signaling pathways are involved in TRPV4 activation-induced increase in IGly. This study indicates that GlyRs may be effective targets for TRPV4-induced modulation of hippocampal inhibitory neurotransmission. © 2018 The Author(s). Published by S. Karger AG, Basel.

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.

Transient Relay Function of Midline Thalamic Nuclei during Long-Term Memory Consolidation in Humans

ERIC Educational Resources Information Center

Thielen, Jan-Willem; Takashima, Atsuko; Rutters, Femke; Tendolkar, Indira; Fernández, Guillén

2015-01-01

To test the hypothesis that thalamic midline nuclei play a transient role in memory consolidation, we reanalyzed a prospective functional MRI study, contrasting recent and progressively more remote memory retrieval. We revealed a transient thalamic connectivity increase with the hippocampus, the medial prefrontal cortex (mPFC), and a…

Transient Heat Transfer in TCAP Coils

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

Steimke, J.L.

1999-03-09

The Thermal Cycling Absorption Process (TCAP) is used to separate isotopes of hydrogen. TCAP involves passing a stream of mixed hydrogen isotopes through palladium deposited on kieselguhr (Pd/k) while cycling the temperature of the Pd/k. Kieselguhr is a silica mineral also called diatomite. To aid in the design of a full scale facility, the Thermal Fluids Laboratory was used by the Chemical and Hydrogen Technology Section to compare the heat transfer properties of three different configurations of stainless steel coils containing kieselguhr and helium. Testing of coils containing Pd/k and hydrogen isotopes would have been more prototypical but would havemore » been too expensive. Three stainless steel coils filled with kieselguhr were tested; one made from 2.0 inch diameter tubing, one made from 2.0 inch diameter tubing with foam copper embedded in the kieselguhr and one made from 1.25 inch diameter tubing. It was known prior to testing that increasing the tubing diameter from 1.25 inch to 2.0 inch would slow the rate of temperature change. The primary purpose of the testing was to measure to what extent the presence of copper foam in a 2.0" tubing coil would compensate for the effect of larger diameter. Each coil was connected to a pressure gage and the coil was evacuated and backfilled with helium gas. Helium was used instead of a mixture of hydrogen isotopes for reasons of safety. Each coil was quickly immersed in a stirred bath of ethylene glycol at a temperature of approximately 100 degrees Celsius. The coil pressure increased, reflecting the increase in average temperature of its contents. The pressure transient was recored as a function of time after immersion. Because of the actual process will use Pd/k instead of kieselguhr, additional tests were run to determine the differences in thermal properties between the two materials. The method was to position a thermocouple at the center of a hollow sphere and pack the sphere with Pd/k. The sphere was sealed

Transient Heat Transfer in TCAP Coils

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

Steimke, J.L.

1999-03-09

The Thermal Cycling Absorption Process (TCAP) is used to separate isotopes of hydrogen. TCAP involves passing a stream of mixed hydrogen isotopes through palladium deposited on kieselguhr (Pd/k) while cycling the temperature of the Pd/k. Kieselguhr is a silica mineral also called diatomite. To aid in the design of a full scale facility, the Thermal Fluids Laboratory was used by the Chemical and Hydrogen Technology Section to compare the heat transfer properties of three different configurations of stainless steel coils containing kieselguhr and helium. Testing of coils containing Pd/k and hydrogen isotopes would have been more prototypical but would havemore » been too expensive. Three stainless steel coils filled with kieselguhr were tested; one made from 2.0 inch diameter tubing, one made from 2.0 inch diameter tubing with foam copper embedded in the kieselguhr and one made from 1.25 inch diameter tubing. It was known prior to testing that increasing the tubing diameter from 1.25 inch to 2.0 inch would slow the rate of temperature change. The primary purpose of the testing was to measure to what extent the presence of copper foam in a 2.0 tubing coil would compensate for the effect of larger diameter. Each coil was connected to a pressure gage and the coil was evacuated and backfilled with helium gas. Helium was used instead of a mixture of hydrogen isotopes for reasons of safety. Each coil was quickly immersed in a stirred bath of ethylene glycol at a temperature of approximately 100 degrees Celsius. The coil pressure increased, reflecting the increase in average temperature of its contents. The pressure transient was recored as a function of time after immersion. Because of the actual process will use Pd/k instead of kieselguhr, additional tests were run to determine the differences in thermal properties between the two materials. The method was to position a thermocouple at the center of a hollow sphere and pack the sphere with Pd/k. The sphere was sealed

Mild neonatal hyperthyrotrophinaemia: 10-year experience suggests the condition is increasingly common but often transient.

PubMed

Oren, Asaf; Wang, Michael K; Brnjac, Lori; Mahmud, Farid H; Palmert, Mark R

2013-12-01

To examine a large population of infants with mild neonatal hyperthyrotrophinaemia (MNH) and determine prevalence, clinical characteristics and treatment history. Retrospective study of infants with MNH followed at The Hospital for Sick Children between 2000 and 2011. MNH was defined by an abnormal newborn screen followed by thyroid-stimulating hormone (TSH) between 5 and 30 mU/l and normal free T4 (FT4) on confirmatory tests. Mild neonatal hyperthyrotrophinaemia represented 22·3% of patients (103/462; 60 boys, 43 girls) within our clinic. Incidence increased from two of 20 in 2000 to 31 of 74 cases in 2010. Seventy eight percent of patients started L-thyroxine (initial dose: 8·3 ± 2·5 mcg/kg). The treated group had higher confirmatory TSH levels (P = 0·001) and had undergone thyroid scintigraphy more often (P = 0·0001) compared with the nontreated group. Evidence of overtreatment was detected in 45% of thyroid function tests obtained during treatment. Among the treated infants who had reached 3 years of age, 45% (N = 14) underwent a trial-off medication. Compared with those not trialled-off therapy, these infants were less likely to have had dose escalations during treatment (P = 0·001). The trial-off treatment was successful in 50% of cases. In the subset of infants with confirmatory TSH >10 mU/l, trial-off therapy was successful in 40%. None of the assessed variables predicted success of trial-off therapy. Mild neonatal hyperthyrotrophinaemia is an increasingly common diagnosis. It is more common in males and is often transient, but predictors of success of trial-off therapy were not identified. Further studies are needed to determine optimum L-thyroxine dosing and to determine whether treatment improves neurocognitive outcomes. © 2013 John Wiley & Sons Ltd.

Transient glutathione depletion in the substantia nigra compacta is associated with neuroinflammation in rats.

PubMed

Díaz-Hung, Mei-Li; Yglesias-Rivera, Arianna; Hernández-Zimbrón, Luis Fernando; Orozco-Suárez, Sandra; Ruiz-Fuentes, Jenny Laura; Díaz-García, Alexis; León-Martínez, Rilda; Blanco-Lezcano, Lisette; Pavón-Fuentes, Nancy; Lorigados-Pedre, Lourdes

2016-10-29

Glutathione (GSH) deficiency has been identified as an early event in the progression of Parkinson's disease. However, the role of GSH in the etiology and pathogenesis of this neurodegenerative disorder is not well established. The aim of this study is to assess the effect of transient GSH depletion in the substantia nigra pars compacta (SNpc) on neuroinflammation after the injection of a single dose of l-buthionine sulfoximine (BSO) into the SNpc of male Sprague-Dawley rats. The results showed that BSO treatment stimulates microglia (p<0.01) and astroglial response (p<0.01), c-Jun N-terminal kinase and inducible nitric oxide synthase (iNOS) (p<0.001) in the SNpc, accompanied by dopaminergic dysfunction. In addition, high levels of tumor necrosis factor α (p<0.01), interleukins IL-1β p<0.01), IL-6 p<0.001) and nitric oxide p<0.01) were found in the treated animals compared to control groups, while no significant differences were found in IL-10 levels. These results suggest that transient GSH depletion can increase the susceptibility of SNpc to degeneration by promoting an inflammatory response and nitrosative stress, reinforcing the possible role of GSH unbalance, oxygen/nitrogen reactive species and neuroinflammation as causal factors on the degeneration of the SNpc. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

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

Successful Object Encoding Induces Increased Directed Connectivity in Presymptomatic Early-Onset Alzheimer’s Disease

PubMed Central

Ochoa, John Fredy; Alonso, Joan Francesc; Duque, Jon Edinson; Tobón, Carlos Andrés; Mañanas, Miguel Angel; Lopera, Francisco; Hernández, Alher Mauricio

2016-01-01

Background: Recent studies report increases in neural activity in brain regions critical to episodic memory at preclinical stages of Alzheimer’s disease (AD). Although electroencephalography (EEG) is widely used in AD studies, given its non-invasiveness and low cost, there is a need to translate the findings in other neuroimaging methods to EEG. Objective: To examine how the previous findings using functional magnetic resonance imaging (fMRI) at preclinical stage in presenilin-1 E280A mutation carriers could be assessed and extended, using EEG and a connectivity approach. Methods: EEG signals were acquired during resting and encoding in 30 normal cognitive young subjects, from an autosomal dominant early-onset AD kindred from Antioquia, Colombia. Regions of the brain previously reported as hyperactive were used for connectivity analysis. Results: Mutation carriers exhibited increasing connectivity at analyzed regions. Among them, the right precuneus exhibited the highest changes in connectivity. Conclusion: Increased connectivity in hyperactive cerebral regions is seen in individuals, genetically-determined to develop AD, at preclinical stage. The use of a connectivity approach and a widely available neuroimaging technique opens the possibility to increase the use of EEG in early detection of preclinical AD. PMID:27792014

Discovery and Classification of ZTF Transients

NASA Astrophysics Data System (ADS)

Lunnan, Ragnhild; Taddia, Francesco; Sollerman, Jesper; Barbarino, Cristina; Goobar, Ariel; Fremling, Christoffer; Kasliwal, Mansi; Cannella, Chris; Blagorodnova, Nadejda; Neill, J. Don; Walters, Richard; Ho, Anna; Yan, Lin; Burdge, Kevin; Schulze, Steve; Yaron, Ofer; Gal-Yam, Avishay; Yang, Yi; Graham, Melissa; Golkhou, V. Zach; Bellm, Eric; Parley, Daniel; Zwicky Transient Facility Collaboration

2018-04-01

We report spectroscopic classifications of 17 transients discovered by the Zwicky Transient Facility (ZTF; ATel #11266) during science validation. Additional classifications of older transients have been reported to and are publicly available on the TNS. Spectra were obtained with DBSP at the Palomar 200-in Hale Telescope, with DIS at the ARC 3.5m telescope at Apache Point Observatory, and with SPRAT at Liverpool Telescope.

Transient nature of late Pleistocene climate variability.

PubMed

Crowley, Thomas J; Hyde, William T

2008-11-13

Climate in the early Pleistocene varied with a period of 41 kyr and was related to variations in Earth's obliquity. About 900 kyr ago, variability increased and oscillated primarily at a period of approximately 100 kyr, suggesting that the link was then with the eccentricity of Earth's orbit. This transition has often been attributed to a nonlinear response to small changes in external boundary conditions. Here we propose that increasing variablility within the past million years may indicate that the climate system was approaching a second climate bifurcation point, after which it would transition again to a new stable state characterized by permanent mid-latitude Northern Hemisphere glaciation. From this perspective the past million years can be viewed as a transient interval in the evolution of Earth's climate. We support our hypothesis using a coupled energy-balance/ice-sheet model, which furthermore predicts that the future transition would involve a large expansion of the Eurasian ice sheet. The process responsible for the abrupt change seems to be the albedo discontinuity at the snow-ice edge. The best-fit model run, which explains almost 60% of the variance in global ice volume during the past 400 kyr, predicts a rapid transition in the geologically near future to the proposed glacial state. Should it be attained, this state would be more 'symmetric' than the present climate, with comparable areas of ice/sea-ice cover in each hemisphere, and would represent the culmination of 50 million years of evolution from bipolar nonglacial climates to bipolar glacial climates.

A methodology for the efficient integration of transient constraints in the design of aircraft dynamic systems

NASA Astrophysics Data System (ADS)

Phan, Leon L.

The motivation behind this thesis mainly stems from previous work performed at Hispano-Suiza (Safran Group) in the context of the European research project "Power Optimised Aircraft". Extensive testing on the COPPER Bird RTM, a test rig designed to characterize aircraft electrical networks, demonstrated the relevance of transient regimes in the design and development of dynamic systems. Transient regimes experienced by dynamic systems may have severe impacts on the operation of the aircraft. For example, the switching on of a high electrical load might cause a network voltage drop inducing a loss of power available to critical aircraft systems. These transient behaviors are thus often regulated by dynamic constraints, requiring the dynamic signals to remain within bounds whose values vary with time. The verification of these peculiar types of constraints, which generally requires high-fidelity time-domain simulation, intervenes late in the system development process, thus potentially causing costly design iterations. The research objective of this thesis is to develop a methodology that integrates the verification of dynamic constraints in the early specification of dynamic systems. In order to circumvent the inefficiencies of time-domain simulation, multivariate dynamic surrogate models of the original time-domain simulation models are generated, building on a nonlinear system identification technique using wavelet neural networks (or wavenets), which allow the multiscale nature of transient signals to be captured. However, training multivariate wavenets can become computationally prohibitive as the number of design variables increases. Therefore, an alternate approach is formulated, in which dynamic surrogate models using sigmoid-based neural networks are used to emulate the transient behavior of the envelopes of the time-domain response. Thus, in order to train the neural network, the envelopes are extracted by first separating the scales of the dynamic response

Wide Field Radio Transient Surveys

NASA Astrophysics Data System (ADS)

Bower, Geoffrey

2011-04-01

The time domain of the radio wavelength sky has been only sparsely explored. Nevertheless, serendipitous discovery and results from limited surveys indicate that there is much to be found on timescales from nanoseconds to years and at wavelengths from meters to millimeters. These observations have revealed unexpected phenomena such as rotating radio transients and coherent pulses from brown dwarfs. Additionally, archival studies have revealed an unknown class of radio transients without radio, optical, or high-energy hosts. The new generation of centimeter-wave radio telescopes such as the Allen Telescope Array (ATA) will exploit wide fields of view and flexible digital signal processing to systematically explore radio transient parameter space, as well as lay the scientific and technical foundation for the Square Kilometer Array. Known unknowns that will be the target of future transient surveys include orphan gamma-ray burst afterglows, radio supernovae, tidally-disrupted stars, flare stars, and magnetars. While probing the variable sky, these surveys will also provide unprecedented information on the static radio sky. I will present results from three large ATA surveys (the Fly's Eye survey, the ATA Twenty CM Survey (ATATS), and the Pi GHz Survey (PiGSS)) and several small ATA transient searches. Finally, I will discuss the landscape and opportunities for future instruments at centimeter wavelengths.

Daytime Sleepiness Increases With Age in Early Adolescence: A Sleep Restriction Dose-Response Study.

PubMed

Campbell, Ian G; Burright, Christopher S; Kraus, Amanda M; Grimm, Kevin J; Feinberg, Irwin

2017-05-01

Daytime sleepiness increases across adolescence. This increase is commonly attributed to insufficient sleep durations resulting from increasingly limited time in bed. We tested the effects of 3 sleep schedules on daytime sleepiness and whether these effects changed with age in early adolescence. In 77 children ranging in age from 9.9 to 14 years, objective (multiple sleep latency test [MSLT]) and subjective (Karolinska sleepiness scale [KSS]) sleepiness was measured following 4 consecutive nights of either 7, 8.5, or 10 hours in bed. All participants completed all 3 sleep schedules. The order in which they completed the schedules was not randomized but was accounted for in all statistical analyses. Time in bed restriction decreased sleep duration and increased objective and subjective daytime sleepiness. Although the sleep durations did not change with age, the likelihood of falling asleep during the MSLT increased with age. Nevertheless, sleep restriction produced a greater increase in MSLT-measured sleepiness in younger participants. Subjective sleepiness measured with the KSS increased with shorter sleep duration, but this effect did not change with age. Increasing objective daytime sleepiness in early adolescence cannot simply be attributed to reduced sleep due to restricted sleep schedules. We propose that some of the increased daytime sleepiness of adolescents is a consequence of adolescent brain reorganization driven by synaptic pruning which decreases the intensity of waking brain activity. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Transient multivariable sensor evaluation

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

Vilim, Richard B.; Heifetz, Alexander

A method and system for performing transient multivariable sensor evaluation. The method and system includes a computer system for identifying a model form, providing training measurement data, generating a basis vector, monitoring system data from sensor, loading the system data in a non-transient memory, performing an estimation to provide desired data and comparing the system data to the desired data and outputting an alarm for a defective sensor.

Improving the management and referral of patients with transient ischaemic attacks: a change strategy for a health community.

PubMed

Wright, J; Harrison, S; McGeorge, M; Patterson, C; Russell, I; Russell, D; Small, N; Taylor, M; Walsh, M; Warren, E; Young, J

2006-02-01

Rapid referral and management of patients with transient ischaemic attacks is a key component in the national strategy for stroke prevention. However, patients with transient ischaemic attacks are poorly identified and undertreated. Before and after evaluation of quality improvement programme with controlled comparison in three primary care trusts reflecting diverse populations and organisational structures in an urban district in the North of England. The proportion of patients receiving antiplatelet drugs and safe driving advice on referral to a specialty clinic, and the numbers of referrals, adjusted for age, to the specialist clinic before and after the improvement programme. Interviews with patient and professionals to identify gaps and barriers to good practice; development of evidence based guidelines for the management of patients with transient ischaemic attacks; interactive multidisciplinary workshops for each primary care trust with feedback of individual audit results of referral practice; outreach visits to teams who were unable to attend the workshops; referral templates and desktop summaries to provide reminders of the guidelines to clinicians; incorporation of standards into professional contracts. A significant improvement occurred in identification and referral of patients with transient ischaemic attacks to specialist clinics, with a 41% increase in referrals from trained practices compared with control practices. There were also significant improvements in the early treatment and safety advice provided to patients before referral. A strategic approach to effective quality improvement across a diverse health community is feasible and achievable. Careful planning with patient and professional involvement to develop a tailored and multifaceted quality improvement programme to implement evidence based practice can work in very different primary care settings. Key components of the effectiveness of the model include contextual analysis, strong

Peculiar Behaviors of Faint Galactic Bulge Transients

NASA Technical Reports Server (NTRS)

Swank, J. H.

2004-01-01

The Rossi X-ray Timing Explorer PCA scans of the Galactic bulge (galactic longitude plus or minus 11 degrees) have detected 8 recent transients which have peak intensities of 10 to 400 mCrab. Some of the transient events have a fast rise and slow decay typical of accretion disk instabilities. It is common for these decays to be oscillatory, rather than steady, as if there are waves within the disk. There are also outbursts with symmetric light curves. In particular, the source in Terzan 2 which had a very long (decade) doubling of intensity peaking near the beginning of 1997, in 2004 has had two 30 day brightenings by a factor of 5 only 100 days apart. During each of these a burst was observed in snapshot observations near the peak. The source SLX 1735-269, also a burster, though not in our observations, has had irregularly repeated occurrences of fast swings between close to zero and 2-4 times normal. Some examples, such as the increase, drop, and slow recovery of GS 1826-238 suggest a change in the accretion disk such as emptying and refilling or a peculiar alignment. Follow up observations have provided deeper information about these transient sources and possible explanations for their behavior will be addressed.

Platelet activating factor induces transient blood-brain barrier opening to facilitate edaravone penetration into the brain.

PubMed

Fang, Weirong; Zhang, Rui; Sha, Lan; Lv, Peng; Shang, Erxin; Han, Dan; Wei, Jie; Geng, Xiaohan; Yang, Qichuan; Li, Yunman

2014-03-01

The blood-brain barrier (BBB) greatly limits the efficacy of many neuroprotective drugs' delivery to the brain, so improving drug penetration through the BBB has been an important focus of research. Here we report that platelet activating factor (PAF) transiently opened BBB and facilitated neuroprotectant edaravone penetration into the brain. Intravenous infusion with PAF induced a transient BBB opening in rats, reflected by increased Evans blue leakage and mild edema formation, which ceased within 6 h. Furthermore, rat regional cerebral blood flow (rCBF) declined acutely during PAF infusion, but recovered slowly. More importantly, this transient BBB opening significantly increased the penetration of edaravone into the brain, evidenced by increased edaravone concentrations in tissue interstitial fluid collected by microdialysis and analyzed by Ultra-performance liquid chromatograph combined with a hybrid quadrupole time-of-flight mass spectrometer (UPLC-MS/MS). Similarly, incubation of rat brain microvessel endothelial cells monolayer with 1 μM PAF for 1 h significantly increased monolayer permeability to (125)I-albumin, which recovered 1 h after PAF elimination. However, PAF incubation with rat brain microvessel endothelial cells for 1 h did not cause detectable cytotoxicity, and did not regulate intercellular adhesion molecule-1, matrix-metalloproteinase-9 and P-glycoprotein expression. In conclusion, PAF could induce transient and reversible BBB opening through abrupt rCBF decline, which significantly improved edaravone penetration into the brain. Platelet activating factor (PAF) transiently induces BBB dysfunction and increases BBB permeability, which may be due to vessel contraction and a temporary decline of regional cerebral blood flow (rCBF) triggered by PAF. More importantly, the PAF induced transient BBB opening facilitates neuroprotectant edaravone penetration into brain. The results of this study may provide a new approach to improve drug delivery into

DEdicated MONitor of EXotransits and Transients (DEMONEXT): Low-Cost Robotic and Automated Telescope for Followup of Exoplanetary Transits and Transients

NASA Astrophysics Data System (ADS)

Villanueva, Steven; Eastman, Jason D.; Gaudi, B. Scott; Pogge, Richard W.; Stassun, Keivan G.; Trueblood, Mark; Trueblood, Patricia

2017-01-01

We present the design, development, and early science from the DEdicated MONitor of EXotransits and Transients (DEMONEXT), an automated and robotic 20 inch telescope jointly funded by The Ohio State University and Vanderbilt University. The telescope is a PlaneWave CDK20 f/6.8 Corrected Dall-Kirkham Astrograph telescope on a Mathis Instruments MI-750/1000 Fork Mount located at Winer Observatory in Sonoita, AZ. DEMONEXT has a Hedrick electronic focuser, Finger Lakes Instrumentation (FLI) CFW-3-10 filter wheel, and a 2048 x 2048 pixel FLI Proline CCD3041 camera with a pixel scale of 0.90 arc-seconds per pixel and a 30.7 x 30.7 arc-minute field-of-view. The telescope's automation, controls, and scheduling are implemented in Python, including a facility to add new targets in real time for rapid follow-up of time-critical targets. DEMONEXT will be used for the confirmation and detailed investigation of newly discovered planet candidates from the Kilodegree Extremely Little Telescope (KELT) survey, exploration of the atmospheres of Hot Jupiters via transmission spectroscopy and thermal emission measurements, and monitoring of select eclipsing binary star systems as benchmarks for models of stellar evolution. DEMONEXT will enable rapid confirmation imaging of supernovae, flare stars, tidal disruption events, and other transients discovered by the All Sky Automated Survey for SuperNovae (ASAS-SN).

Transient Performance Improvement Circuit (TPIC)s for DC-DC converter applications

NASA Astrophysics Data System (ADS)

Lim, Sungkeun

Gordon Moore famously predicted the exponential increase in transistor integration and computing power that has been witnessed in recent decades [1]. In the near future, it is expected that more than one billion transistors will be integrated per chip, and advanced microprocessors will require clock speeds in excess of several GHz. The increasing number of transistors and high clock speeds will necessitate the consumption of more power. By 2014, it is expected that the maximum power consumption of the microprocessor will reach approximately 150W, and the maximum load current will be around 150A. Today's trend in power and thermal management is to reduce supply voltage as low as possible to reduce delivered power. It is anticipated that the Intel cores will operate on 0.8V of supply voltage by 2014 [2]. A significant challenge in Voltage Regulator Module (VRM) development for next generation microprocessors is to regulate the supply voltage within a certain tolerance band during high slew rate load transitions, since the required supply voltage tolerance band will be much narrower than the current requirement. If VR output impedance is maintained at a constant value from DC to high frequency, large output voltage spikes can be avoided during load cur- rent transients. Based on this, the Adaptive Voltage Position (AVP) concept was developed to achieve constant VR output impedance to improve transient response performance [3]. However, the VR output impedance can not be made constant over the entire frequency range with AVP design, because the AVP design makes the VR output impedance constant only at low frequencies. To make the output impedance constant at high frequencies, many bulk capacitors and ceramic capacitors are required. The tight supply voltage tolerance for the next generation of microprocessors during high slew rate load transitions requires fast transient response power supplies. A VRM can not follow the high slew rate load current transients, because

Runaway transient simulation of a model Kaplan turbine

NASA Astrophysics Data System (ADS)

Liu, S.; Zhou, D.; Liu, D.; Wu, Y.; Nishi, M.

2010-08-01

The runaway transient is a typical transient process of a hydro power unit, where the rotational speed of a turbine runner rapidly increases up to the runaway speed under a working head as the guide vanes cannot be closed due to some reason at the load rejection. In the present paper, the characteristics of the runaway transient of a model Kaplan turbine having ns = 479(m-kW) is simulated by using a time-dependent CFD technique where equation of rotational motion of runner, continuity equation and unsteady RANS equations with RNG k-epsilon turbulence model are solved iteratively. In the calculation, unstructured mesh is used to the whole flow passage, which consists of several sub-domains: entrance, casing, stay vanes + guide vanes, guide section, runner and draft tube. And variable speed sliding mesh technique is used to exchange interface flow information between moving part and stationary part, and three-dimensional unstructured dynamic mesh technique is also adopted to ensure mesh quality. Two cases were treated in the simulation of runaway transient characteristics after load rejection: one is the rated operating condition as the initial condition, and the other is the condition at the maximum head. Regarding the runaway speed, the experimental speed is 1.45 times the initial speed and the calculation is 1.47 times the initial for the former case. In the latter case, the experiment and the calculation are 1.67 times and 1.69 times respectively. From these results, it is recognized that satisfactorily prediction will be possible by using the present numerical method. Further, numerical results show that the swirl in the draft-tube flow becomes stronger in the latter part of the transient process so that a vortex rope will occur in the draft tube and its precession will cause the pressure fluctuations which sometimes affect the stability of hydro power system considerably.

[Neonatal morbidity in early-term newborns].

PubMed

Martínez-Nadal, S; Demestre, X; Raspall, F; Alvarez, J A; Elizari, M J; Vila, C; Sala, P

2014-07-01

In the last decades has increased significantly The birth of children from 37 to 38 weeks of gestation, a period called early term, has significantly increased in the past twenty years or so, parallel to the increase in induced deliveries and the cesarean rate. Retrospective cohorts population study, which included those babies born between 37 and 41 weeks of gestation in the period 1992-2011 (n=35.539). This population was divided into two cohorts, early term newborn (RNTP) of 37-38 weeks (n=11,318), and full term newborn (RNTC), of 39-41 weeks of gestation (n=24,221). The rates of cesarean section, neonatal unit admission, respiratory morbidity, apnea and need for assisted ventilation, hyperbilirubinemia requiring phototherapy, hypoglycemia, seizures, hypoxic-ischemia encephalopathy, need for parenteral nutrition and early sepsis were all reviewed. There was a progressive increase in the number of caesarean sections throughout the period studied (from 30.9% to 40.3%). The cesarean section rate was higher in RNTP than in the RNTC (38.3% vs 31.3%, P<.0001). On comparing the two groups, significant differences were found in the rate of admission to neonatal unit, 9.1% vs 3.5% (P<.0001); respiratory morbidity (hyaline membrane 0.14% vs 0.007% [P<.0001], transient tachypnea 1.71% vs 0.45% [P<.0001], mechanical ventilation 0.2% vs 0.07% [P<.009], continuous positive airway pressure 0.11% vs 0.01% [P<.0001]), phototherapy 0.29% vs 0.07% (P<.0001), hypoglycemia 0.54% vs 0.11% (P<.0001), parenteral nutrition 0.16% vs 0.04% (P<.0001). There were no significant differences in the rate of early sepsis, pneumothorax, aspiration syndromes, seizures and hypoxic-ischemic encephalopathy. In our environment, there is a significant number of RNTP, which have a significantly higher morbidity than newborns RNTC registered. After individualizing each case, it is essential not end a pregnancy before 39 weeks of gestation, except for maternal, placental or fetal conditions indicating

Fiber type-specific afferent nerve activity induced by transient contractions of rat bladder smooth muscle in pathological states

PubMed Central

Kuga, Nahoko; Tanioka, Asao; Hagihara, Koichiro; Kawai, Tomoyuki

2017-01-01

Bladder smooth muscle shows spontaneous phasic contractions, which undergo a variety of abnormal changes depending on pathological conditions. How abnormal contractions affect the activity of bladder afferent nerves remains to be fully tested. In this study, we examined the relationship between transient increases in bladder pressure, representing transient contraction of bladder smooth muscle, and spiking patterns of bladder afferent fibers of the L6 dorsal root, in rat pathological models. All recordings were performed at a bladder pressure of approximately 10 cmH2O by maintaining the degree of bladder filling. In the cyclophosphamide-induced model, both Aδ and C fibers showed increased sensitivity to transient bladder pressure increases. In the prostaglandin E2-induced model, Aδ fibers, but not C fibers, specifically showed overexcitation that was time-locked with transient bladder pressure increases. These fiber type-specific changes in nerve spike patterns may underlie the symptoms of urinary bladder diseases. PMID:29267380

Netherton Syndrome in a Neonate with Possible Growth Hormone Deficiency and Transient Hyperaldosteronism

PubMed Central

Ilias, Chatziioannidis; Evgenia, Babatseva; Aikaterini, Patsatsi; Asimina, Galli-Tsinopoulou; Constantina, Sarri; Maria, Lithoxopoulou; George, Mitsiakos; Paraskevi, Karagianni; Christos, Tsakalidis; Zissis, Mamuris; Nikolaos, Nikolaidis

2015-01-01

Netherton syndrome, a rare autosomal recessive genetic disorder, is classified as an ichthyosiform syndrome. In this report we present the case of a neonate with erythroderma shortly after birth, accompanied by severe hypernatremia, recurrent infections, transient hyperaldosteronism, and signs of growth hormone (GH) deficiency. DNA molecular analysis in the SPINK5 gene revealed heterozygosity in our index patient for 238insG and 2468delA frameshift mutations in exons 4 and 26, respectively, in the maternal allele and 1431-12G>A splice-site mutation in intron 15 in the paternal allele as well as the missense variation E420K in homozygous state. Combination of the identified mutations along with transient hyperaldosteronism and possible GH deficiency have not been described before. Accordingly, the importance of early multidisciplinary approach is highlighted, in order to reach accurate diagnosis, initiate prompt treatment, and ensure survival with fewer disease complications. PMID:26229701

Transient well flow in vertically heterogeneous aquifers

NASA Astrophysics Data System (ADS)

Hemker, C. J.

1999-11-01

A solution for the general problem of computing well flow in vertically heterogeneous aquifers is found by an integration of both analytical and numerical techniques. The radial component of flow is treated analytically; the drawdown is a continuous function of the distance to the well. The finite-difference technique is used for the vertical flow component only. The aquifer is discretized in the vertical dimension and the heterogeneous aquifer is considered to be a layered (stratified) formation with a finite number of homogeneous sublayers, where each sublayer may have different properties. The transient part of the differential equation is solved with Stehfest's algorithm, a numerical inversion technique of the Laplace transform. The well is of constant discharge and penetrates one or more of the sublayers. The effect of wellbore storage on early drawdown data is taken into account. In this way drawdowns are found for a finite number of sublayers as a continuous function of radial distance to the well and of time since the pumping started. The model is verified by comparing results with published analytical and numerical solutions for well flow in homogeneous and heterogeneous, confined and unconfined aquifers. Instantaneous and delayed drainage of water from above the water table are considered, combined with the effects of partially penetrating and finite-diameter wells. The model is applied to demonstrate that the transient effects of wellbore storage in unconfined aquifers are less pronounced than previous numerical experiments suggest. Other applications of the presented solution technique are given for partially penetrating wells in heterogeneous formations, including a demonstration of the effect of decreasing specific storage values with depth in an otherwise homogeneous aquifer. The presented solution can be a powerful tool for the analysis of drawdown from pumping tests, because hydraulic properties of layered heterogeneous aquifer systems with

Analysis of Spontaneous and Nerve-Evoked Calcium Transients in Intact Extraocular Muscles in Vitro

PubMed Central

Feng, Cheng-Yuan; Hennig, Grant W.; Corrigan, Robert D.; Smith, Terence K.; von Bartheld, Christopher S.

2012-01-01

Extraocular muscles (EOMs) have unique calcium handling properties, yet little is known about the dynamics of calcium events underlying ultrafast and tonic contractions in myofibers of intact EOMs. Superior oblique EOMs of juvenile chickens were dissected with their nerve attached, maintained in oxygenated Krebs buffer, and loaded with fluo-4. Spontaneous and nerve stimulation-evoked calcium transients were recorded and, following calcium imaging, some EOMs were double-labeled with rhodamine-conjugated alpha-bungarotoxin (rhBTX) to identify EOM myofiber types. EOMs showed two main types of spontaneous calcium transients, one slow type (calcium waves with 1/2max duration of 2–12 s, velocity of 25–50 μm/s) and two fast “flash-like” types (Type 1, 30–90 ms; Type 2, 90–150 ms 1/2max duration). Single pulse nerve stimulation evoked fast calcium transients identical to the fast (Type 1) calcium transients. Calcium waves were accompanied by a local myofiber contraction that followed the calcium transient wavefront. The magnitude of calcium-wave induced myofiber contraction far exceeded those of movement induced by nerve stimulation and associated fast calcium transients. Tetrodotoxin eliminated nerve-evoked transients, but not spontaneous transients. Alpha-bungarotoxin eliminated both spontaneous and nerve-evoked fast calcium transients, but not calcium waves, and caffeine increased wave activity. Calcium waves were observed in myofibers lacking spontaneous or evoked fast transients, suggestive of multiply-innervated myofibers, and this was confirmed by double-labeling with rhBTX. We propose that the abundant spontaneous calcium transients and calcium waves with localized contractions that do not depend on innervation may contribute to intrinsic generation of tonic functions of EOMs. PMID:22579493

Characterizing transient noise in the LIGO detectors.

PubMed

Nuttall, L K

2018-05-28

Data from the LIGO detectors typically contain many non-Gaussian noise transients which arise due to instrumental and environmental conditions. These non-Gaussian transients can be an issue for the modelled and unmodelled transient gravitational-wave searches, as they can mask or mimic a true signal. Data quality can change quite rapidly, making it imperative to track and find new sources of transient noise so that data are minimally contaminated. Several examples of transient noise and the tools used to track them are presented. These instances serve to highlight the diverse range of noise sources present at the LIGO detectors during their second observing run.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'. © 2018 The Author(s).

Characterizing transient noise in the LIGO detectors

NASA Astrophysics Data System (ADS)

Nuttall, L. K.

2018-05-01

Data from the LIGO detectors typically contain many non-Gaussian noise transients which arise due to instrumental and environmental conditions. These non-Gaussian transients can be an issue for the modelled and unmodelled transient gravitational-wave searches, as they can mask or mimic a true signal. Data quality can change quite rapidly, making it imperative to track and find new sources of transient noise so that data are minimally contaminated. Several examples of transient noise and the tools used to track them are presented. These instances serve to highlight the diverse range of noise sources present at the LIGO detectors during their second observing run. This article is part of a discussion meeting issue `The promises of gravitational-wave astronomy'.

A hybrid method for transient wave propagation in a multilayered solid

NASA Astrophysics Data System (ADS)

Tian, Jiayong; Xie, Zhoumin

2009-08-01

We present a hybrid method for the evaluation of transient elastic-wave propagation in a multilayered solid, integrating reverberation matrix method with the theory of generalized rays. Adopting reverberation matrix formulation, Laplace-Fourier domain solutions of elastic waves in the multilayered solid are expanded into the sum of a series of generalized-ray group integrals. Each generalized-ray group integral containing Kth power of reverberation matrix R represents the set of K-times reflections and refractions of source waves arriving at receivers in the multilayered solid, which was computed by fast inverse Laplace transform (FILT) and fast Fourier transform (FFT) algorithms. However, the calculation burden and low precision of FILT-FFT algorithm limit the application of reverberation matrix method. In this paper, we expand each of generalized-ray group integrals into the sum of a series of generalized-ray integrals, each of which is accurately evaluated by Cagniard-De Hoop method in the theory of generalized ray. The numerical examples demonstrate that the proposed method makes it possible to calculate the early-time transient response in the complex multilayered-solid configuration efficiently.

Teaching Children to Understand Operations in Early Childhood

ERIC Educational Resources Information Center

Ladhams, Jan

2005-01-01

The author discusses teaching early child mathematics in an environment of unique challenge in a remote region of Western Australia. The challenges include: (1) a high proportion of transient students; (2) a student population that is forty percent aboriginal, many for whom English is a second language; (3) students who consistently perform below…

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.

On transient rheology and glacial isostasy

NASA Technical Reports Server (NTRS)

Yuen, David A.; Sabadini, Roberto C. A.; Gasperini, Paolo; Boschi, Enzo

1986-01-01

The effect of transient creep on the inference of long-term mantle viscosity is investigated using theoretical predictions from self-gravitating, layered earth models with Maxwell, Burgers' body, and standard linear solid rheologies. The interaction between transient and steady-state rheologies is studied. The responses of the standard linear solid and Burgers' body models to transient creep in the entire mantle, and of the Burgers' body and Maxwell models to creep in the lower mantle are described. The models' responses are examined in terms of the surface displacement, free air gravity anomaly, wander of the rotation pole, and the secular variation of the degree 2 zonal coefficient of the earth's gravitational potential field. The data reveal that transient creep cannot operate throughout the entire mantle.

Transients control in Raman fiber amplifiers

NASA Astrophysics Data System (ADS)

Freitas, Marcio; Givigi, Sidney N., Jr.; Klein, Jackson; Calmon, Luiz C.; de Almeida, Ailson R.

2004-11-01

Raman fiber amplifiers (RFA) are being used in optical transmission communication systems in the recent years due to their advantages in comparison to erbium-doped fiber amplifiers (EDFA). Recently the analysis of RFAs dynamic response and transients control has become important in order to predict the system response to add/drop of channels or cable cuts in optical systems, and avoid impairments caused by the power transients. Fast signal power transients in the surviving channels are caused by the cross-gain saturation effect in RFA and the slope of the gain saturation characteristics determines the steady-state surviving channel power excursion. We are presenting the modeling and analysis of power transients and its control using a pump control method for a single and multi-pump scheme.

Transient immune deficiency in patients with acute Epstein-Barr virus infection.

PubMed

Junker, A K; Ochs, H D; Clark, E A; Puterman, M L; Wedgwood, R J

1986-09-01

To study the effect of primary Epstein-Barr virus (EBV) infection on antigen-specific antibody production, we immunized 17 college students who had developed acute infectious mononucleosis with the T-cell dependent neoantigen bacteriophage phi X174. During the early phase of infectious mononucleosis, the proportion of peripheral blood lymphocytes displaying Ia and T8 (CD8) phenotypes was increased and the T helper/suppressor (T4/T8) ratio was decreased (less than 1). These abnormalities disappeared during the convalescent phase. Correlating with EBV-induced changes in T lymphocytes, we demonstrated depressed humoral immune responses to bacteriophage phi X174 both in vivo and in vitro. In vitro coculture experiments indicated that the Ia+ suppressor T cells could inhibit antibody production and isotype switch. Removal of T8+ lymphocytes from patient T cells normalized in vitro antibody synthesis. In addition, impaired B-cell function was shown to be in part responsible for deficient antibody production. These studies demonstrate that infection with EBV affects both B and T lymphocytes and causes a broad-based transient immune deficiency in patients with uncomplicated infectious mononucleosis.

Moisture-triggered physically transient electronics

PubMed Central

Gao, Yang; Zhang, Ying; Wang, Xu; Sim, Kyoseung; Liu, Jingshen; Chen, Ji; Feng, Xue; Xu, Hangxun; Yu, Cunjiang

2017-01-01

Physically transient electronics, a form of electronics that can physically disappear in a controllable manner, is very promising for emerging applications. Most of the transient processes reported so far only occur in aqueous solutions or biofluids, offering limited control over the triggering and degradation processes. We report novel moisture-triggered physically transient electronics, which exempt the needs of resorption solutions and can completely disappear within well-controlled time frames. The triggered transient process starts with the hydrolysis of the polyanhydride substrate in the presence of trace amounts of moisture in the air, a process that can generate products of corrosive organic acids to digest various inorganic electronic materials and components. Polyanhydride is the only example of polymer that undergoes surface erosion, a distinct feature that enables stable operation of the functional devices over a predefined time frame. Clear advantages of this novel triggered transience mode include that the lifetime of the devices can be precisely controlled by varying the moisture levels and changing the composition of the polymer substrate. The transience time scale can be tuned from days to weeks. Various transient devices, ranging from passive electronics (such as antenna, resistor, and capacitor) to active electronics (such as transistor, diodes, optoelectronics, and memories), and an integrated system as a platform demonstration have been developed to illustrate the concept and verify the feasibility of this design strategy. PMID:28879237

Generalized seizures and transient contralateral hemiparesis following retrobulbar anesthesia: a case report.

PubMed

Dettoraki, Maria; Dimitropoulou, Chrisafoula; Nomikarios, Nikolaos; Moschos, Marilita M; Brοuzas, Dimitrios

2015-07-28

Retrobulbar block is a local anesthetic technique widely used for intraocular surgery. Although retrobulbar anesthesia is considered to be relatively safe, a number of serious adverse events have been reported. To our knowledge, immediate onset of generalized seizures with contralateral hemiparesis after retrobulbar anesthesia has not been reported. A 62-year-old Caucasian healthy male with a right eye retinal detachment was admitted for pars plana vitrectomy. During retrobulbar anesthesia with ropivacaine and before needle withdrawal, the patient developed twitching of the face which rapidly progressed to generalized tonic-clonic seizures. Arterial oxygen saturation decreased to 75 %. Chin lift was performed and 100 % oxygen was administrated via face mask, which increased saturation to 99 %. Midazolam 2 mg was administrated intravenously to control seizures. After cessation of seizures, left-sided hemiparesis was evident. Brain computed tomography and electroencephalogram were normal 3 h later. The patient underwent pars plana vitrectomy under general anesthesia 4 days later. Serious complications of local anesthesia for ophthalmic surgery are uncommon. We present a case in which generalized tonic-clonic seizures developed during retrobulbar anesthesia, followed by transient contralateral hemiparesis. The early onset of seizures indicated intra-arterial injection of the anesthetic. Our case suggested the need for close monitoring during the performance of retrobulbar anesthesia and the presence of well-trained personnel for early recognition and immediate management of the complications.

Asiago spectroscopic classification of six optical transients

NASA Astrophysics Data System (ADS)

Tomasella, L.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Ochner, P.; Pastorello, A.; Tartaglia, L.; Terreran, G.; Turatto, M.

2015-01-01

The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of the following transients. Targets were supplied by the Astronomy Section of the Rochester Academy of Sciences (arXiv:1103.5165), the CBAT Transient Objects Confirmation Page (TOCP) and the Gaia Photometric Science Alerts (validation phase).

Transient proton inflows during illumination of anaerobic Halobacterium halobium cells

NASA Technical Reports Server (NTRS)

Helgerson, S. L.; Stoeckenius, W.

1985-01-01

The roles of bacteriorhodopsin (bR), halorhodopsin (hR), and the H(+)-ATPase in the proton uptake in intact cells are examined. The Halobacterium halobium strains and solutions utilized in the experiment, and the techniques for measuring extracellular pH changes and intracellular K(+) concentrations are described. It is observed that in Halobacterium halobium strain R1, containing bR and hR, the light-driven proton uptake is divided into three transient inflows superimposed on the larger proton outflow. Under anaerobic conditions early proton uptake consists of an inflow which can be blocked with Dio-9 and a second inflow that can be eliminated by low concentrations (less than 125 nm) of triphenyltin chloride (TPT). The effects of Dio-9 and TPT on the passive proton-hydroxyl permeability of the cell membrane are investigated. A third transient light-driven proton flow observed at later times of illumination is studied. The data reveal that the first proton inflow correlates with proton dependent ATP synthesis; the second inflow is a passive uptake through an unidentified channel in response to electrogenic chloride pumping by bR and/or hR; and the third inflow correlates with the Na(+)/H(+) antiporter function.

Dissolved Nutrient Retention Dynamics in River Networks: A Modeling Investigation of Transient Flow and Scale Effects

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

Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu

In this paper, we use a dynamic network flow model, coupled with a transient storage zone biogeochemical model, to simulate dissolved nutrient removal processes at the channel network scale. We have explored several scenarios in respect of the combination of rainfall variability, and the biological and geomorphic characteristics of the catchment, to understand the dominant controls on removal and delivery of dissolved nutrients (e.g., nitrate). These model-based theoretical analyses suggested that while nutrient removal efficiency is lower during flood events compared to during baseflow periods, flood events contribute significantly to bulk nutrient removal, whereas bulk removal during baseflow periods ismore » less. This is due to the fact that nutrient supply is larger during flood events; this trend is even stronger in large rivers. However, the efficiency of removal during both periods decreases in larger rivers, however, due to (i) increasing flow velocities and thus decreasing residence time, and (ii) increasing flow depth, and thus decreasing nutrient uptake rates. Besides nutrient removal processes can be divided into two parts: in the main channel and in the hyporheic transient storage zone. When assessing their relative contributions the size of the transient storage zone is a dominant control, followed by uptake rates in the main channel and in the transient storage zone. Increasing size of the transient storage zone with downstream distance affects the relative contributions to nutrient removal of the water column and the transient storage zone, which also impacts the way nutrient removal rates scale with increasing size of rivers. Intra-annual hydrologic variability has a significant impact on removal rates at all scales: the more variable the streamflow is, compared to mean discharge, the less nutrient is removed in the channel network. A scale-independent first order uptake coefficient, ke, estimated from model simulations, is highly dependent on

Summer 1993 Transient Student Report.

ERIC Educational Resources Information Center

Kent State Univ., Warren, OH. Office of Institutional Research.

A study was conducted by the Trumbull Campus (TC) of Kent State University, in Ohio, to determine the motivations, objectives, and level of satisfaction of transient students, or students pursuing a degree at another institution but enrolled in courses at TC. Surveys were mailed to 50 transient students enrolled in summer 1993, with completed…

ZTF Bright Transient Survey classifications

NASA Astrophysics Data System (ADS)

Fremling, C.; Sharma, Y.; Skulkarni, S. R.; Walters, R.; Blagorodnova, N.; Neill, J. D.; Miller, A. A.; Taggart, K.; Perley, D. A.; Goobar, A.; Graham, M. L.

2018-06-01

The Zwicky Transient Facility (ZTF; ATel #11266) Bright Transient Survey (BTS; ATel #11688) reports classifications of the following targets. Spectra have been obtained with the Spectral Energy Distribution Machine (SEDM) (range 350-950nm, spectral resolution R 100) mounted on the Palomar 60-inch (P60) telescope (Blagorodnova et. al. 2018, PASP, 130, 5003).

Impaired mitochondria and intracellular calcium transients in the salivary glands of obese rats.

PubMed

Ittichaicharoen, Jitjiroj; Apaijai, Nattayaporn; Tanajak, Pongpan; Sa-Nguanmoo, Piangkwan; Chattipakorn, Nipon; Chattipakorn, Siriporn C

2017-04-01

Long-term consumption of a high-fat diet (HFD) causes not only obese-insulin resistance, but is also associated with mitochondrial dysfunction in several organs. However, the effect of obese-insulin resistance on salivary glands has not been investigated. We hypothesized that obese-insulin resistance induced by HFD impaired salivary gland function by reducing salivation, increasing inflammation, and fibrosis, as well as impairing mitochondrial function and calcium transient signaling. Male Wistar rats (200-220 g) were fed either a ND or an HFD (n = 8/group) for 16 weeks. At the end of week 16, salivary flow rates, metabolic parameters, and plasma oxidative stress were determined. Rats were then sacrificed and submandibular glands were removed to determine inflammation, fibrosis, apoptosis, mitochondrial function and dynamics, and intracellular calcium transient signaling. Long-term consumption of an HFD caused obese-insulin resistance and increased oxidative stress, fibrosis, inflammation, and apoptosis in the salivary glands. In addition, impaired mitochondrial function, as indicated by increased mitochondrial reactive oxygen species, mitochondrial membrane depolarization, and mitochondrial swelling in salivary glands and impaired intracellular calcium regulation, as indicated by a reduced intracellular calcium transient rising rate, decay rates, and amplitude of salivary acinar cells, were observed in HFD-fed rats. However, salivary flow rate and level of aquaporin 5 protein were not different between both groups. Although HFD consumption did not affect salivation, it caused obese-insulin resistance, leading to pathophysiological alteration of salivary glands, including impaired intracellular calcium transients, increased oxidative stress and inflammation, and salivary mitochondrial dysfunction.

Brief early handling increases morphine dependence in adult rats.

PubMed

Vazquez, Vincent; Penit-Soria, Jacqueline; Durand, Claudette; Besson, Marie-Jo; Giros, Bruno; Daugé, Valérie

2006-06-30

Short early manipulations of rodent postnatal environment may trigger long-term effects on neurobiological and behavioural phenotypes in adulthood. However, little is known about such effects of handling on the vulnerability to develop drug dependence. The present study aimed to analyze the long-term effects of a brief handling (1 min) on morphine and ethanol dependence and on the preproenkephalin (PPE) mRNA and mu opioid receptor levels. Handled rats showed a significant increase in morphine (25mg/l) but not ethanol (10%) consumption and preference after 7 weeks and no difference in morphine (2 and 5mg/kg) conditioned place preference. No difference of preproenkephalin mRNA and mu opioid receptor levels was detected in the mesolimbic system between both groups. These data emphasize that human brief handling, which can lead to morphine dependence development, constitutes in itself an experimental treatment and not a control condition.

Polycystic ovary syndrome and early-onset preeclampsia: reproductive manifestations of increased cardiovascular risk.

PubMed

Veltman-Verhulst, Susanne M; van Rijn, Bas B; Westerveld, H Egbertine; Franx, Arie; Bruinse, Hein W; Fauser, Bart C J M; Goverde, Angelique J

2010-01-01

Primary prevention of cardiovascular disease (CVD) in women is a major healthcare issue. Detection of premenopausal women with increased risk of CVD could enhance prevention strategies and reduce first event-related morbidity and mortality. In this study, we argue that an unfavorable metabolic constitution in women may present itself early in life as a reproductive complication, such as polycystic ovary syndrome (PCOS) and preeclampsia. We evaluated the cardiovascular risk of women with a history of early-onset preeclampsia and women with PCOS and assessed their need for implementation of early risk factor-reduction strategies. We performed a standardized evaluation of 240 women with a history of early-onset preeclampsia and 456 women diagnosed with PCOS for established major CVD risk factors. Metabolic syndrome characteristics were analyzed per body mass index category. Mean age was 30.6 and 29.0 years for women with preeclampsia and PCOS, respectively. High percentages of metabolic syndrome were found in both groups (preeclampsia group, 14.6%; and PCOS group, 18.4%), with an incidence of greater than 50% in both groups of women if body mass index was greater than 30 kg/m. Overall, more than 90% of the women qualified for either lifestyle or medical intervention according to the American Heart Association guideline for CVD prevention in women. Women with PCOS and early-onset preeclampsia already show an unfavorable cardiovascular risk profile with high need for lifestyle or medical intervention at a young age. We therefore recommend an active role of the gynecologist in routine screening and follow-up of women with reproductive conditions linked to future cardiovascular risk.

Analyte-induced spectral filtering in femtosecond transient absorption spectroscopy

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

Abraham, Baxter; Nieto-Pescador, Jesus; Gundlach, Lars

Here, we discuss the influence of spectral filtering by samples in femtosecond transient absorption measurements. Commercial instruments for transient absorption spectroscopy (TA) have become increasingly available to scientists in recent years and TA is becoming an established technique to measure the dynamics of photoexcited systems. Furthermore, we show that absorption of the excitation pulse by the sample can severely alter the spectrum and consequently the temporal pulse shape. This “spectral self-filtering” effect can lead to systematic errors and misinterpretation of data, most notably in concentration dependent measurements. Finally, the combination of narrow absorption peaks in the sample with ultrafast broadbandmore » excitation pulses is especially prone to this effect.« less

Analyte-induced spectral filtering in femtosecond transient absorption spectroscopy

DOE PAGES

Abraham, Baxter; Nieto-Pescador, Jesus; Gundlach, Lars

2017-03-06

Here, we discuss the influence of spectral filtering by samples in femtosecond transient absorption measurements. Commercial instruments for transient absorption spectroscopy (TA) have become increasingly available to scientists in recent years and TA is becoming an established technique to measure the dynamics of photoexcited systems. Furthermore, we show that absorption of the excitation pulse by the sample can severely alter the spectrum and consequently the temporal pulse shape. This “spectral self-filtering” effect can lead to systematic errors and misinterpretation of data, most notably in concentration dependent measurements. Finally, the combination of narrow absorption peaks in the sample with ultrafast broadbandmore » excitation pulses is especially prone to this effect.« less

Low-Level Blast Exposure Increases Transient Receptor Potential Vanilloid 1 (TRPV1) Expression in the Rat Cornea

PubMed Central

Por, Elaine D.; Choi, Jae-Hyek; Lund, Brian J.

2016-01-01

ABSTRACT Background: Blast-related ocular injuries sustained by military personnel have led to rigorous efforts to elucidate the effects of blast exposure on neurosensory function. Recent studies have provided some insight into cognitive and visual deficits sustained following blast exposure; however, limited data are available on the effects of blast on pain and inflammatory processes. Investigation of these secondary effects of blast exposure is necessary to fully comprehend the complex pathophysiology of blast-related injuries. The overall purpose of this study is to determine the effects of single and repeated blast exposure on pain and inflammatory mediators in ocular tissues. Methods: A compressed air shock tube was used to deliver a single or repeated blast (68.0 ± 2.7 kPa) to anesthetized rats daily for 5 days. Immunohistochemistry was performed on ocular tissues to determine the expression of the transient receptor potential vanilloid 1 (TRPV1) channel, calcitonin gene-related peptide (CGRP), substance P (SP), and endothelin-1 (ET-1) following single and repeated blast exposure. Neutrophil infiltration and myeloperoxidase (MPO) expression were also assessed in blast tissues via immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) analysis, respectively. Results: TRPV1 expression was increased in rat corneas exposed to both single and repeated blast. Increased secretion of CGRP, SP, and ET-1 was also detected in rat corneas as compared to control. Moreover, repeated blast exposure resulted in neutrophil infiltration in the cornea and stromal layer as compared to control animals. Conclusion: Single and repeated blast exposure resulted in increased expression of TRPV1, CGRP, SP, and ET-1 as well as neutrophil infiltration. Collectively, these findings provide novel insight into the activation of pain and inflammation signaling mediators following blast exposure. PMID:27049881

In vitro early changes in intercellular junctions by treatment with a chemical carcinogen.

PubMed

Tachikawa, T; Kohno, Y; Matsui, Y; Yoshiki, S

1986-06-01

To examine early intercellular junction changes caused by treatment with 9,10-dimethyl-1,2-benzanthracene (DMBA), rat lingual epithelium was cultivated in isolation and observed by electrophysiological, freeze-fracture and whole-mount electron microscopy. Electrophysiological measurements showed a transient decrease in membrane potential of -10.2 mV 6 h after the treatment. It returned to almost the same level as that of the control group 1 day later. Six hours after treatment, input resistance decreased rapidly to 5.3 M omega but increased to 18.0 M omega 12 h after treatment. Transient reduction of input resistance and membrane potential occurred prior to the decrease in the coupling ratio 6 h after treatment with DMBA. In freeze-fracture replicas, the number of gap junctions decreased by approximately 45% of the control value 6 h after treatment with DMBA. At 12 h and thereafter, the number and area of gap junctions subsequently decreased by 60-80% of the control value. Alterations in the number and area of desmosomes were similar to those of the gap junctions. The formation of epithelial cytoskeletons, partially devoid of the 2-4 and 5-8 nm filaments was also observed. A decrease in the density of filament networks beneath the plasma membranes was especially apparent. Treatment with a carcinogen brought about morphological cellular changes as early as 6 h after treatment, and such early changes might trigger metabolic cellular abnormalities. Affected cells appear to move away from normal cells in a process of repeated destruction and revision of intercellular junctions, and cytoskeletons.

Transient adhesion in a non-fully detached contact.

PubMed

Liu, Zheyu; Lu, Hongyu; Zheng, Yelong; Tao, Dashuai; Meng, Yonggang; Tian, Yu

2018-04-18

Continuous approaching and detaching displacement usually occurs in an adhesion test. Here, we found a transient adhesion force at the end of a non-fully detached contact. This force occurred when the nominal detaching displacement was less than the traditional quasi-static theory predicted zero force point. The transient adhesion force was ascribed to interfacial adhesion hysteresis, which was caused by the cracking process of the contact and the deformation competition between the sphere and supporting spring. Results indicated that the testing of adhesion can be significantly affected by different combinations of stiffnesses of the contact objects and the supporting spring cantilever. This combination should be carefully designed in an adhesion test. All these results enabled increased understanding of the nature of adhesion and can guide the design of adhesive actuators.

Increased Pre- and Early-Adolescent Stress in Youth with a Family History of Substance Use Disorder and Early Substance Use Initiation.

PubMed

Charles, Nora E; Mathias, Charles W; Acheson, Ashley; Bray, Bethany C; Ryan, Stacy R; Lake, Sarah L; Liang, Yuanyuan; Dougherty, Donald M

2015-10-01

Individuals with a family history of substance use disorders (Family History Positive) are more likely to have early-onset substance use (i.e., prior to age 15), which may contribute to their higher rates of substance use disorders. One factor that may differentiate Family History Positive youth who engage in early-onset substance use from other Family History Positive youth is exposure to stressors. The aim of this study was to quantify how exposure to stressors from age 11-15 varies as a function of family history of substance use disorders and early-onset substance use. Self-reported stressors were prospectively compared in a sample of predominately (78.9%) Hispanic youth that included 68 Family History Positive youth (50% female) who initiated substance use by age 15 and demographically matched non-users with (n = 136; 52.9% female) and without (n = 75; 54.7% female) family histories of substance use disorders. Stressors were assessed at 6-month intervals for up to 4 years. Both the severity of stressors and the degree to which stressors were caused by an individual's own behavior were evaluated. All three groups differed from one another in overall exposure to stressors and rates of increase in stressors over time, with Family History Positive youth who engaged in early-onset substance use reporting the greatest exposure to stressors. Group differences were more pronounced for stressors caused by the participants' behavior. Family History Positive users had higher cumulative severity of stressors of this type, both overall and across time. These results indicate greater exposure to stressors among Family History Positive youth with early-onset substance use, and suggest that higher rates of behavior-dependent stressors may be particularly related to early-onset use.

Increased Pre- and Early-Adolescent Stress in Youth with a Family History of Substance Use Disorder and Early Substance Use Initiation

PubMed Central

Charles, Nora E.; Mathias, Charles W.; Acheson, Ashley; Bray, Bethany C.; Ryan, Stacy R.; Lake, Sarah L.; Liang, Yuanyuan; Dougherty, Donald M.

2015-01-01

Individuals with a family history of substance use disorders (Family History Positive) are more likely to have early-onset substance use (i.e., prior to age 15), which may contribute to their higher rates of substance use disorders. One factor that may differentiate Family History Positive youth who engage in early-onset substance use from other Family History Positive youth is exposure to stressors. The aim of this study was to quantify how exposure to stressors from age 11 to 15 varies as a function of family history of substance use disorders and early-onset substance use. Self-reported stressors were prospectively compared in a sample of predominately (78.9%) Hispanic youth that included 68 Family History Positive youth (50% female) who initiated substance use by age 15 and demographically matched non-users with (n=136; 52.9% female) and without (n=75; 54.7% female) family histories of substance use disorders. Stressors were assessed at 6-month intervals for up to 4 years. Both the severity of stressors and the degree to which stressors were caused by an individual’s own behavior were evaluated. All three groups differed from one another in overall exposure to stressors and rates of increase in stressors over time, with Family History Positive youth who engaged in early-onset substance use reporting the greatest exposure to stressors. Group differences were more pronounced for stressors caused by the participants’ behavior. Family History Positive users had higher cumulative severity of stressors of this type, both overall and across time. These results indicate greater exposure to stressors among Family History Positive youth with early-onset substance use, and suggest that higher rates of behavior-dependent stressors may be particularly related to early-onset use. PMID:25788123

Transient generation of hydrogen peroxide is responsible for carcinostatic effects of hydrogen combined with platinum nanocolloid, together with increases intracellular ROS, DNA cleavages, and proportion of G2/M-phase.

PubMed

Saitoh, Yasukazu; Ikeshima, Minoru; Kawasaki, Naho; Masumoto, Aoi; Miwa, Nobuhiko

2016-01-01

In our previous study, we demonstrated that combined treatment with hydrogen (H2) and platinum nanocolloid (Pt-nc) exerted markedly antiproliferative effects on cancer cells compared with each treatment alone. However, because the related mechanisms remain unclear, we investigated carcinostatic mechanisms of the combined treatment with H2 + Pt-nc. Significant suppression of cell proliferation was confirmed at 52 h following combined treatment, and the similar effect was also observed by the 30- or 40-min transient treatment with H2 + Pt-nc. The transient treatments led to changes in cell size and morphology, loss of microvilli, and apoptosis-like cell death at 120 h after treatment. Moreover, transient combined treatment with H2 + Pt-nc induced cell-cycle arrest, as reflected by decreased proportions of G1-phase cells and accumulation of G2/M-phase cells. In contrast, intracellular peroxide levels were temporarily and significantly increased immediately after H2 + Pt-nc treatment but not after treatment with H2 or Pt-nc alone. Additionally, combined treatment-induced carcinostatic effects were significantly diminished in the presence of catalase, and marked hydrogen peroxide (H2O2) generation was confirmed after mixing Pt-nc into cell culture media containing a high concentration of H2. These changes are in agreement with the results that carcinostatic effects were induced after only 40 min of treatment with H2 + Pt-nc. Thus, transient and marked generation of H2O2 is responsible for the carcinostatic effects of combined treatment with H2 + Pt-nc.

Increased prolactin levels are associated with impaired processing speed in subjects with early psychosis.

PubMed

Montalvo, Itziar; Gutiérrez-Zotes, Alfonso; Creus, Marta; Monseny, Rosa; Ortega, Laura; Franch, Joan; Lawrie, Stephen M; Reynolds, Rebecca M; Vilella, Elisabet; Labad, Javier

2014-01-01

Hyperprolactinaemia, a common side effect of some antipsychotic drugs, is also present in drug-naïve psychotic patients and subjects at risk for psychosis. Recent studies in non-psychiatric populations suggest that increased prolactin may have negative effects on cognition. The aim of our study was to explore whether high plasma prolactin levels are associated with poorer cognitive functioning in subjects with early psychoses. We studied 107 participants: 29 healthy subjects and 78 subjects with an early psychosis (55 psychotic disorders with <3 years of illness, 23 high-risk subjects). Cognitive assessment was performed with the MATRICS Cognitive Consensus Cognitive Battery, and prolactin levels were determined as well as total cortisol levels in plasma. Psychopathological status was assessed and the use of psychopharmacological treatments (antipsychotics, antidepressants, benzodiazepines) recorded. Prolactin levels were negatively associated with cognitive performance in processing speed, in patients with a psychotic disorder and high-risk subjects. In the latter group, increased prolactin levels were also associated with impaired reasoning and problem solving and poorer general cognition. In a multiple linear regression analysis conducted in both high-risk and psychotic patients, controlling for potential confounders, prolactin and benzodiazepines were independently related to poorer cognitive performance in the speed of processing domain. A mediation analysis showed that both prolactin and benzodiazepine treatment act as mediators of the relationship between risperidone/paliperidone treatment and speed of processing. These results suggest that increased prolactin levels are associated with impaired processing speed in early psychosis. If these results are confirmed in future studies, strategies targeting reduction of prolactin levels may improve cognition in this population.

Increased Prolactin Levels Are Associated with Impaired Processing Speed in Subjects with Early Psychosis

PubMed Central

Montalvo, Itziar; Gutiérrez-Zotes, Alfonso; Creus, Marta; Monseny, Rosa; Ortega, Laura; Franch, Joan; Lawrie, Stephen M.; Reynolds, Rebecca M.; Vilella, Elisabet; Labad, Javier

2014-01-01

Hyperprolactinaemia, a common side effect of some antipsychotic drugs, is also present in drug-naïve psychotic patients and subjects at risk for psychosis. Recent studies in non-psychiatric populations suggest that increased prolactin may have negative effects on cognition. The aim of our study was to explore whether high plasma prolactin levels are associated with poorer cognitive functioning in subjects with early psychoses. We studied 107 participants: 29 healthy subjects and 78 subjects with an early psychosis (55 psychotic disorders with <3 years of illness, 23 high-risk subjects). Cognitive assessment was performed with the MATRICS Cognitive Consensus Cognitive Battery, and prolactin levels were determined as well as total cortisol levels in plasma. Psychopathological status was assessed and the use of psychopharmacological treatments (antipsychotics, antidepressants, benzodiazepines) recorded. Prolactin levels were negatively associated with cognitive performance in processing speed, in patients with a psychotic disorder and high-risk subjects. In the latter group, increased prolactin levels were also associated with impaired reasoning and problem solving and poorer general cognition. In a multiple linear regression analysis conducted in both high-risk and psychotic patients, controlling for potential confounders, prolactin and benzodiazepines were independently related to poorer cognitive performance in the speed of processing domain. A mediation analysis showed that both prolactin and benzodiazepine treatment act as mediators of the relationship between risperidone/paliperidone treatment and speed of processing. These results suggest that increased prolactin levels are associated with impaired processing speed in early psychosis. If these results are confirmed in future studies, strategies targeting reduction of prolactin levels may improve cognition in this population. PMID:24586772

Increased genetic vulnerability to smoking at CHRNA5 in early-onset smokers.

PubMed

Hartz, Sarah M; Short, Susan E; Saccone, Nancy L; Culverhouse, Robert; Chen, LiShiun; Schwantes-An, Tae-Hwi; Coon, Hilary; Han, Younghun; Stephens, Sarah H; Sun, Juzhong; Chen, Xiangning; Ducci, Francesca; Dueker, Nicole; Franceschini, Nora; Frank, Josef; Geller, Frank; Gubjartsson, Daniel; Hansel, Nadia N; Jiang, Chenhui; Keskitalo-Vuokko, Kaisu; Liu, Zhen; Lyytikäinen, Leo-Pekka; Michel, Martha; Rawal, Rajesh; Rosenberger, Albert; Scheet, Paul; Shaffer, John R; Teumer, Alexander; Thompson, John R; Vink, Jacqueline M; Vogelzangs, Nicole; Wenzlaff, Angela S; Wheeler, William; Xiao, Xiangjun; Yang, Bao-Zhu; Aggen, Steven H; Balmforth, Anthony J; Baumeister, Sebastian E; Beaty, Terri; Bennett, Siiri; Bergen, Andrew W; Boyd, Heather A; Broms, Ulla; Campbell, Harry; Chatterjee, Nilanjan; Chen, Jingchun; Cheng, Yu-Ching; Cichon, Sven; Couper, David; Cucca, Francesco; Dick, Danielle M; Foroud, Tatiana; Furberg, Helena; Giegling, Ina; Gu, Fangyi; Hall, Alistair S; Hällfors, Jenni; Han, Shizhong; Hartmann, Annette M; Hayward, Caroline; Heikkilä, Kauko; Hewitt, John K; Hottenga, Jouke Jan; Jensen, Majken K; Jousilahti, Pekka; Kaakinen, Marika; Kittner, Steven J; Konte, Bettina; Korhonen, Tellervo; Landi, Maria-Teresa; Laatikainen, Tiina; Leppert, Mark; Levy, Steven M; Mathias, Rasika A; McNeil, Daniel W; Medland, Sarah E; Montgomery, Grant W; Muley, Thomas; Murray, Tanda; Nauck, Matthias; North, Kari; Pergadia, Michele; Polasek, Ozren; Ramos, Erin M; Ripatti, Samuli; Risch, Angela; Ruczinski, Ingo; Rudan, Igor; Salomaa, Veikko; Schlessinger, David; Styrkársdóttir, Unnur; Terracciano, Antonio; Uda, Manuela; Willemsen, Gonneke; Wu, Xifeng; Abecasis, Goncalo; Barnes, Kathleen; Bickeböller, Heike; Boerwinkle, Eric; Boomsma, Dorret I; Caporaso, Neil; Duan, Jubao; Edenberg, Howard J; Francks, Clyde; Gejman, Pablo V; Gelernter, Joel; Grabe, Hans Jörgen; Hops, Hyman; Jarvelin, Marjo-Riitta; Viikari, Jorma; Kähönen, Mika; Kendler, Kenneth S; Lehtimäki, Terho; Levinson, Douglas F; Marazita, Mary L; Marchini, Jonathan; Melbye, Mads; Mitchell, Braxton D; Murray, Jeffrey C; Nöthen, Markus M; Penninx, Brenda W; Raitakari, Olli; Rietschel, Marcella; Rujescu, Dan; Samani, Nilesh J; Sanders, Alan R; Schwartz, Ann G; Shete, Sanjay; Shi, Jianxin; Spitz, Margaret; Stefansson, Kari; Swan, Gary E; Thorgeirsson, Thorgeir; Völzke, Henry; Wei, Qingyi; Wichmann, H-Erich; Amos, Christopher I; Breslau, Naomi; Cannon, Dale S; Ehringer, Marissa; Grucza, Richard; Hatsukami, Dorothy; Heath, Andrew; Johnson, Eric O; Kaprio, Jaakko; Madden, Pamela; Martin, Nicholas G; Stevens, Victoria L; Stitzel, Jerry A; Weiss, Robert B; Kraft, Peter; Bierut, Laura J

2012-08-01

Recent studies have shown an association between cigarettes per day (CPD) and a nonsynonymous single-nucleotide polymorphism in CHRNA5, rs16969968. To determine whether the association between rs16969968 and smoking is modified by age at onset of regular smoking. Primary data. Available genetic studies containing measures of CPD and the genotype of rs16969968 or its proxy. Uniform statistical analysis scripts were run locally. Starting with 94,050 ever-smokers from 43 studies, we extracted the heavy smokers (CPD >20) and light smokers (CPD ≤10) with age-at-onset information, reducing the sample size to 33,348. Each study was stratified into early-onset smokers (age at onset ≤16 years) and late-onset smokers (age at onset >16 years), and a logistic regression of heavy vs light smoking with the rs16969968 genotype was computed for each stratum. Meta-analysis was performed within each age-at-onset stratum. Individuals with 1 risk allele at rs16969968 who were early-onset smokers were significantly more likely to be heavy smokers in adulthood (odds ratio [OR] = 1.45; 95% CI, 1.36-1.55; n = 13,843) than were carriers of the risk allele who were late-onset smokers (OR = 1.27; 95% CI, 1.21-1.33, n = 19,505) (P = .01). These results highlight an increased genetic vulnerability to smoking in early-onset smokers.

Transient statistics in stabilizing periodic orbits

NASA Astrophysics Data System (ADS)

Meucci, R.; Gadomski, W.; Ciofini, M.; Arecchi, F. T.

1995-11-01

The statistics of chaotic and periodic transient time intervals preceding the stabilization of a given periodic orbit have been experimentally studied in a CO2 laser with modulated losses, subjected to a small subharmonic perturbation. As predicted by the theory, an exponential tail has been found in the probability distribution of chaotic transients. Furthermore, a fine periodic structure in the distributions of the periodic transients, resulting from the interaction of the control signal and the local structure of the chaotic attractor, has been revealed.

Single-Event Transients in Voltage Regulators

NASA Technical Reports Server (NTRS)

Johnston, Allan H.; Miyahira, Tetsuo F.; Irom, F.; Laird, Jamie S.

2006-01-01

Single-event transients are investigated for two voltage regulator circuits that are widely used in space. A circuit-level model is developed that can be used to determine how transients are affected by different circuit application conditions. Internal protection circuits-which are affected by load as well as internal thermal effects-can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. Although conventional output transients can be reduced by adding load capacitance, that approach is ineffective for dropouts from protection circuitry.

Characterizing SI Engine Transient Fuel Consumption in ALPHA

EPA Science Inventory

Examine typical transient engine operation encountered over the EPA's vehicle and engine testing drive cycles to characterize that transient fuel usage, and then describe the changes made to ALPHA to better model transient engine operation.

Production of high transient heat and particle fluxes in a linear plasma device

NASA Astrophysics Data System (ADS)

De Temmerman, G.; Zielinski, J. J.; van der Meiden, H.; Melissen, W.; Rapp, J.

2010-08-01

We report on the generation of high transient heat and particle fluxes in a linear plasma device by pulsed operation of the plasma source. A capacitor bank is discharged into the source to transiently increase the discharge current up to 1.7 kA, allowing peak densities and temperature of 70×1020 m-3 and 6 eV corresponding to a surface power density of about 400 MW m-2.

Rapidly Evolving Transients in the Dark Energy Survey

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

Pursiainen, M.; et al.

We present the results of a search for rapidly evolving transients in the Dark Energy Survey Supernova Programme. These events are characterized by fast light curve evolution (rise to peak inmore » $$\\lesssim 10$$ d and exponential decline in $$\\lesssim30$$ d after peak). We discovered 72 events, including 37 transients with a spectroscopic redshift from host galaxy spectral features. The 37 events increase the total number of rapid optical transients by more than factor of two. They are found at a wide range of redshifts ($0.05M_\\mathrm{g}>-22.25$$). The multiband photometry is well fit by a blackbody up to few weeks after peak. The events appear to be hot ($$T\\approx10000-30000$$ K) and large ($$R\\approx 10^{14}-2\\cdot10^{15}$$ cm) at peak, and generally expand and cool in time, though some events show evidence for a receding photosphere with roughly constant temperature. Spectra taken around peak are dominated by a blue featureless continuum consistent with hot, optically thick ejecta. We compare our events with a previously suggested physical scenario involving shock breakout in an optically thick wind surrounding a core-collapse supernova (CCSNe), we conclude that current models for such a scenario might need an additional power source to describe the exponential decline. We find these transients tend to favor star-forming host galaxies, which could be consistent with a core-collapse origin. However, more detailed modeling of the light curves is necessary to determine their physical origin.« less

Transient ischemic attack

MedlinePlus

... artery surgery - discharge Stroke - discharge Taking warfarin (Coumadin) Images Endarterectomy Transient Ischemic attack (TIA) References Biller J, Ruland S, Schneck MJ. Ischemic cerebrovascular disease. In Daroff ...

Light induces a rapid and transient increase in inositol-trisphosphate in toad rod outer segments

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

Brown, J.E.; Blazynski, C.; Cohen, A.I.

1987-08-14

The sub-second time course of changes in the content of (/sup 3/H)inositol-1,4,5-trisphosphate was determined in rod outer segments from very rapidly frozen Bufo retinas that had been incubated with (/sup 3/H)inositol. Rod outer segments were cut off frozen specimens with a cryostat microtome and the water soluble extracts were analyzed. The content of (/sup 3/H)inositol-1,4,5-trisphosphate rose after approximately 250 msec of bright illumination, but returned to the unstimulated level after 1 sec, whether the stimulus remained on or not. That is, there was rapid but transient change in the content of (/sup 3/H)inositol-1,4,5-trisphosphate after the onset of stimulation.

Early school outcomes for extremely preterm infants with transient neurological abnormalities.

PubMed

Harmon, Heidi M; Taylor, H Gerry; Minich, Nori; Wilson-Costello, Deanne; Hack, Maureen

2015-09-01

To determine if transient neurological abnormalities (TNA) at 9 months corrected age predict cognitive, behavioral, and motor outcomes at 6 years of age in extremely preterm infants. A cohort of 124 extremely preterm infants (mean gestational age 25.5wks; 55 males, 69 females), admitted to our unit between 2001 and 2003, were classified based on the Amiel-Tison Neurological Assessment at 9 months and 20 months corrected age as having TNA (n=17), normal neurological assessment (n=89), or neurologically abnormal assessment (n=18). The children were assessed at a mean age of 5 years 11 months (SD 4mo) on cognition, academic achievement, motor ability, and behavior. Compared with children with a normal neurological assessment, children with TNA had higher postnatal exposure to steroids (35% vs 9%) and lower adjusted mean scores on spatial relations (84 [standard error {SE} 5] vs 98 [SE 2]), visual matching (79 [SE 5] vs 91 [SE 2]), letter-word identification (97 [SE 4] vs 108 [SE 1]), and spelling (76 [SE 4] vs 96 [SE 2]) (all p<0.05). Despite a normalized neurological assessment, extremely preterm children with a history TNA are at higher risk for lower cognitive and academic skills than those with normal neurological findings during their first year of school. © 2015 Mac Keith Press.

Early school outcomes for extremely preterm infants with transient neurological abnormalities

PubMed Central

Harmon, Heidi; Taylor, H Gerry; Minich, Nori; Wilson-Costello, Deanne; Hack, Maureen

2015-01-01

AIM To determine if transient neurological abnormalities (TNA) at 9 months corrected age predict cognitive, behavioral, and motor outcomes at 6 years of age in extremely preterm infants. METHOD A cohort of 124 extremely preterm infants (mean gestational age 25.5wk; 55 males, 69 females), admitted to our unit between 2001 and 2003, were classified based on the Amiel-Tison Neurological Assessment at 9 months and 20 months corrected age as having TNA (n=17), normal neurological assessment (n=89), or neurologically abnormal assessment (n=18). The children were assessed at a mean age of 5 years 11 months (SD 4mo) on cognition, academic achievement, motor ability, and behavior. RESULTS Compared with children with a normal neurological assessment, children with TNA had higher postnatal exposure to steroids (35% vs 9%) and lower adjusted mean scores on spatial relations (84 [standard error {SE} 5] vs 98 [SE 2]), visual matching (79 [SE 5] vs 91 [SE 2]), letter–word identification (97 [SE 4] vs 108 [SE 1]), and spelling (76 [SE 4] vs 96 [SE 2]) (all p<0.05). INTERPRETATION Despite a normalized neurological assessment, extremely preterm children with a history TNA are at higher risk for lower cognitive and academic skills than those with normal neurological findings during their first year of school. PMID:26014665

Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): a prospective population-based sequential comparison.

PubMed

Rothwell, Peter M; Giles, Matthew F; Chandratheva, Arvind; Marquardt, Lars; Geraghty, Olivia; Redgrave, Jessica N E; Lovelock, Caroline E; Binney, Lucy E; Bull, Linda M; Cuthbertson, Fiona C; Welch, Sarah J V; Bosch, Shelley; Alexander, Faye C; Carasco-Alexander, Faye; Silver, Louise E; Gutnikov, Sergei A; Mehta, Ziyah

2007-10-20

(adjusted hazard ratio 0.20, 95% CI 0.08-0.49; p=0.0001); there was no significant change in risk in patients treated elsewhere. The reduction in risk was independent of age and sex, and early treatment did not increase the risk of intracerebral haemorrhage or other bleeding. Early initiation of existing treatments after TIA or minor stroke was associated with an 80% reduction in the risk of early recurrent stroke. Further follow-up is required to determine long-term outcome, but these results have immediate implications for service provision and public education about TIA and minor stroke.

Thermosensitive transient receptor potential channels (thermo-TRPs) in human corneal epithelial cells

PubMed Central

Mergler, Stefan; Garreis, Fabian; Sahlmüller, Monika; Reinach, Peter S.; Paulsen, Friedrich; Pleyer, Uwe

2010-01-01

Thermosensitive transient receptor potential proteins (TRPs) such as TRPV1-TRPV4 are all heat-activated non-selective cation channels that are modestly permeable to Ca2+. TRPV1, TRPV3 and TRPV4 functional expression were previously identified in human corneal epithelial cells (HCEC). However, the membrane currents were not described underlying their activation by either selective agonists or thermal variation. This study characterized the membrane currents and [Ca 2+]i transients induced by thermal and agonist TRPV1 and 4 stimulation. TRPV1 and 4 expressions were confirmed by RT-PCR and TRPV2 transcripts were also detected. In fura2-loaded HCEC, a TRPV1-3 selective agonist, 100 µM 2-aminoethoxydiphenyl borate (2-APB), induced intracellular Ca2+ transients and an increase in non-selective cation outward currents that were suppressed by ruthenium-red (RuR) (10–20 µM), a nonselective TRPV channel blocker. These changes were also elicited by rises in ambient temperature from 25 °C to over 40 °C. RuR (5 µM) and a selective TRPV1 channel blocker capsazepine (CPZ) (10 µM) or another related blocker, lanthanum chloride (La3+) (100 µM) suppressed these temperature-induced Ca2+ increases. Planar patch-clamp technique was used to characterize the currents underlying Ca2+ transients. Increasing the temperature to over 40 °C induced reversible rises in non-selective cation currents. Moreover, a hypotonic challenge (25 %) increased non-selective cation currents confirming TRPV4 activity. We conclude that HCEC possess in addition to thermo-sensitive TRPV3 activity TRPV1, TRPV2 and TRPV4 activity. Their activation confers temperature sensitivity at the ocular surface, which may protect the cornea against such stress. PMID:21506114

Six years after the El Mayor-Cucapah earthquake: Transient far-field postseismic vertical motion observed by tide gauges and GPS

NASA Astrophysics Data System (ADS)

Smith-Konter, B. R.; Gonzalez-Ortega, J. A.; Merrifield, M. A.; Tong, X.; Sandwell, D. T.; Hardy, S.; Howell, S. M.

2016-12-01

On April 4, 2010, the El Mayor-Cucapah earthquake (Mw 7.2) ruptured a 120 km long set of faults of the southernmost San Andreas Fault System in northeastern Baja California, Mexico. Near-field coseismic GPS observations revealed up to 1.1 m of horizontal surface slip and 0.6 m of vertical subsidence at near-field stations. Early near-field InSAR and GPS time series postseismic observations also suggested several tens of centimeters of afterslip occurred within the first two years, however postseismic transients due to viscoelastic or poroelastic relaxation have also been offered as candidate models. Here we investigate the role of viscoelastic transients from six years of regional far-field ( 200 km from rupture) tide gauge and vertical GPS time series observations to further constrain postseismic deformation mechanisms. Vertical viscoelastic postseismic models of the El Mayor-Cucapah earthquake suggest alternating quadrants of uplift and subsidence straddling the rupture, with uplift to the north near the Salton Trough and subsidence to the west spanning the San Diego and Ensenada regions. These decaying transient motions are confirmed by both vertical postseismic GPS and tide gauge-altimetry observations, in both the near- and far fields. For example, tide gauge data in San Diego, which typically record vertical land motions on the order of a few millimeters per year, recorded nearly 30 mm of transient land subsidence over the first 3 years. We find that the magnitude and decay of far-field postseismic subsidence can be attributed to viscoelastic relaxation of the mantle assuming a temporally varying rheology; viscosities as low as 1017 Pa-s for at least the first 6-12 months, followed by an increasing viscosity on the order of 1018 Pa-s in the years following, best fit the data. While transient viscosity anomalies have been previously suggested from GPS data spanning the first 1.5 years following the earthquake [Pollitz et al., 2012], the combined results from

Transient analysis of a solid oxide fuel cell stack with crossflow configuration

NASA Astrophysics Data System (ADS)

Yuan, P.; Liu, S. F.

2018-05-01

This study investigates the transient response of the cell temperature and current density of a solid oxide fuel cell having 6 stacks with crossflow configuration. A commercial software repeatedly solves the governing equations of each stack, and get the convergent results of the whole SOFC stack. The preliminary results indicate that the average current density of each stack is similar to others, so the power output between different stacks are uniform. Moreover, the average cell temperature among stacks is different, and the central stacks have higher temperature due to its harder heat dissipation. For the operating control, the cell temperature difference among stacks is worth to concern because the temperature difference will be over 10 °C in the analysis case. The increasing of the inlet flow rate of the fuel and air will short the transient state, increase the average current density, and drop the cell temperature difference among the stacks. Therefore, the inlet flow rate is an important factor for transient performance of a SOFC stack.

Increased lung and bladder cancer incidence in adults after in utero and early-life arsenic exposure.

PubMed

Steinmaus, Craig; Ferreccio, Catterina; Acevedo, Johanna; Yuan, Yan; Liaw, Jane; Durán, Viviana; Cuevas, Susana; García, José; Meza, Rodrigo; Valdés, Rodrigo; Valdés, Gustavo; Benítez, Hugo; VanderLinde, Vania; Villagra, Vania; Cantor, Kenneth P; Moore, Lee E; Perez, Saida G; Steinmaus, Scott; Smith, Allan H

2014-08-01

From 1958 to 1970, >100,000 people in northern Chile were exposed to a well-documented, distinct period of high drinking water arsenic concentrations. We previously reported ecological evidence suggesting that early-life exposure in this population resulted in increased mortality in adults from several outcomes, including lung and bladder cancer. We have now completed the first study ever assessing incident cancer cases after early-life arsenic exposure, and the first study on this topic with individual participant exposure and confounding factor data. Subjects included 221 lung and 160 bladder cancer cases diagnosed in northern Chile from 2007 to 2010, and 508 age and gender-matched controls. ORs adjusted for age, sex, and smoking in those only exposed in early life to arsenic water concentrations of ≤110, 110 to 800, and >800 μg/L were 1.00, 1.88 [95% confidence interval (CI), 0.96-3.71], and 5.24 (3.05-9.00; P(trend) < 0.001) for lung cancer, and 1.00, 2.94 (1.29-6.70), and 8.11 (4.31-15.25; P(trend) < 0.001) for bladder cancer. ORs were lower in those not exposed until adulthood. The highest category (>800 μg/L) involved exposures that started 49 to 52 years before, and ended 37 to 40 years before the cancer cases were diagnosed. Lung and bladder cancer incidence in adults was markedly increased following exposure to arsenic in early life, even up to 40 years after high exposures ceased. Such findings have not been identified before for any environmental exposure, and suggest that humans are extraordinarily susceptible to early-life arsenic exposure. Policies aimed at reducing early-life exposure may help reduce the long-term risks of arsenic-related disease. ©2014 American Association for Cancer Research.

Transiently increased glutamate cycling in rat PFC is associated with rapid onset of antidepressant-like effects.

PubMed

Chowdhury, G M I; Zhang, J; Thomas, M; Banasr, M; Ma, X; Pittman, B; Bristow, L; Schaeffer, E; Duman, R S; Rothman, D L; Behar, K L; Sanacora, G

2017-01-01

Several drugs have recently been reported to induce rapid antidepressant effects in clinical trials and rodent models. Although the cellular mechanisms involved remain unclear, reports suggest that increased glutamate transmission contributes to these effects. Here, we demonstrate that the antidepressant-like efficacy of three unique drugs, with reported rapid onset antidepressant properties, is coupled with a rapid transient rise in glutamate cycling in the medial prefronal cortex (mPFC) of awake rats as measured by ex vivo 1 H-[ 13 C]-nuclear magnetic resonance spectroscopy. Rats were acutely pretreated by intraperitoneal injection with a single dose of ketamine (1, 3, 10, 30 and 80 mg kg -1 ), Ro 25-6981 (1, 3 and 10 mg kg -1 ), scopolamine (5, 25 and 100 μg kg -1 ) or vehicle (controls). At fixed times after drug injection, animals received an intravenous infusion of [1,6- 13 C 2 ]glucose for 8 min to enrich the amino-acid pools of the brain with 13 C, followed by rapid euthanasia. The mPFC was dissected, extracted with ethanol and metabolite 13 C enrichments were measured. We found a clear dose-dependent effect of ketamine and Ro 25-6981 on behavior and the percentage of 13 C enrichment of glutamate, glutamine and GABA (γ-aminobutyric acid). Further, we also found an effect of scopolamine on both cycling and behavior. These studies demonstrate that three pharmacologically distinct classes of drugs, clinically related through their reported rapid antidepressant actions, share the common ability to rapidly stimulate glutamate cycling at doses pertinent for their antidepressant-like efficacy. We conclude that increased cycling precedes the antidepressant action at behaviorally effective doses and suggest that the rapid change in cycling could be used to predict efficacy of novel agents or identify doses with antidepressant activity.

Transient phosphorylation of tumor associated microtubule associated protein (TMAP)/cytoskeleton associated protein 2 (CKAP2) at Thr-596 during early phases of mitosis.

PubMed

Hong, Kyung Uk; Choi, Yong-Bock; Lee, Jung-Hwa; Kim, Hyun-Jun; Kwon, Hye-Rim; Seong, Yeon-Sun; Kim, Heung Tae; Park, Joobae; Bae, Chang-Dae; Hong, Kyeong-Man

2008-08-31

Tumor associated microtubule associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2) is a mitotic spindle-associated protein whose expression is cell cycle-regulated and also frequently deregulated in cancer cells. Two monoclonal antibodies (mAbs) against TMAP/CKAP2 were produced: B-1-13 and D-12-3. Interestingly, the reactivity of mAb D-12-3 to TMAP/CKAP2 was markedly decreased specifically in mitotic cell lysate. The epitope mapping study showed that mAb D-12-3 recognizes the amino acid sequence between 569 and 625 and that phosphorylation at T596 completely abolishes the reactivity of the antibody, suggesting that the differential reactivity originates from the phosphorylation status at T596. Immunofluorescence staining showed that mAb D-12-3 fails to detect TMAP/CKAP2 in mitotic cells between prophase and metaphase, but the staining becomes evident again in anaphase, suggesting that phosphorylation at T596 occurs transiently during early phases of mitosis. These results suggest that the cellular functions of TMAP/CKAP2 might be regulated by timely phosphorylation and dephosphorylation during the course of mitosis.

Transient phosphorylation of tumor associated microtubule associated protein (TMAP)/cytoskeleton associated protein 2 (CKAP2) at Thr-596 during early phases of mitosis

PubMed Central

Hong, Kyung Uk; Choi, Yong-Bock; Lee, Jung-Hwa; Kim, Hyun-Jun; Kwon, Hye-Rim; Seong, Yeon-Sun; Kim, Heung Tae; Park, Joobae

2008-01-01

Tumor associated microtubule associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2) is a mitotic spindle-associated protein whose expression is cell cycle-regulated and also frequently deregulated in cancer cells. Two monoclonal antibodies (mAbs) against TMAP/CKAP2 were produced: B-1-13 and D-12-3. Interestingly, the reactivity of mAb D-12-3 to TMAP/CKAP2 was markedly decreased specifically in mitotic cell lysate. The epitope mapping study showed that mAb D-12-3 recognizes the amino acid sequence between 569 and 625 and that phosphorylation at T596 completely abolishes the reactivity of the antibody, suggesting that the differential reactivity originates from the phosphorylation status at T596. Immunofluorescence staining showed that mAb D-12-3 fails to detect TMAP/CKAP2 in mitotic cells between prophase and metaphase, but the staining becomes evident again in anaphase, suggesting that phosphorylation at T596 occurs transiently during early phases of mitosis. These results suggest that the cellular functions of TMAP/CKAP2 might be regulated by timely phosphorylation and dephosphorylation during the course of mitosis. PMID:18779650

Removal of restrictions following primary THA with posterolateral approach does not increase the risk of early dislocation.

PubMed

Gromov, Kirill; Troelsen, Anders; Otte, Kristian Stahl; Ørsnes, Thue; Ladelund, Steen; Husted, Henrik

2015-01-01

Patient education and mobilization restrictions are often used in an attempt to reduce the risk of dislocation following primary THA. To date, there have been no studies investigating the safety of removal of mobilization restrictions following THA performed using a posterolateral approach. In this retrospective non-inferiority study, we investigated the rate of early dislocation following primary THA in an unselected patient cohort before and after removal of postoperative mobilization restrictions. From the Danish National Health Registry, we identified patients with early dislocation in 2 consecutive and unselected cohorts of patients who received primary THA at our institution from 2004 through 2008 (n = 946) and from 2010 through 2014 (n = 1,329). Patients in the first cohort were mobilized with functional restrictions following primary THA whereas patients in the second cohort were allowed unrestricted mobilization. Risk of early dislocation (within 90 days) was compared in the 2 groups and odds ratio (OR)-adjusted for possible confounders-was calculated. Reasons for early dislocation in the 2 groups were identified. When we adjusted for potential confounders, we found no increased risk of early dislocation within 90 days in patients who were mobilized without restrictions. Risk of dislocation within 90 days was lower (3.4% vs 2.8%), risk of dislocation within 30 days was lower (2.1% vs 2.0%), and risk of multiple dislocations (1.8% vs 1.1%) was lower in patients who were mobilized without restrictions, but not statistically significantly so. Increasing age was an independent risk factor for dislocation. Removal of mobilization restrictions from the mobilization protocol following primary THA performed with a posterolateral approach did not lead to an increased risk of dislocation within 90 days.

[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.

Planetary Perspective on Life on Early Mars and the Early Earth

NASA Technical Reports Server (NTRS)

Sleep, Norman H.; Zahnle, Kevin

1996-01-01

Impacts of asteroids and comets posed a major hazard to the continuous existence of early life on Mars as on the Earth. The chief danger was presented by globally distributed ejecta, which for very large impacts takes the form of transient thick rock vapor atmospheres; both planets suffered such impacts repeatedly. The exposed surface on both planets was sterilized when it was quickly heated to the temperature of condensed rock vapor by radiation and rock rain. Shallow water bodies were quickly evaporated and sterilized. Any surviving life must have been either in deep water or well below the surface.

Early stages of Ostwald ripening

NASA Astrophysics Data System (ADS)

Shneidman, Vitaly A.

2013-07-01

The Becker-Döring (BD) nucleation equation is known to predict a narrow double-exponential front (DEF) in the distribution of growing particles over sizes, which is due to early transient effects. When mass conservation is included, nucleation is eventually exhausted while independent growth is replaced by ripening. Despite the enormous difference in the associated time scales, and the resulting demand on numerics, within the generalized BD model the early DEF is shown to be crucial for the selection of the unique self-similar Lifshitz-Slyozov-Wagner asymptotic regime. Being preserved till the latest stages of growth, the DEF provides a universal part of the initial conditions for the ripening problem, regardless of the mass exchange mechanism between the nucleus and the matrix.

Are early-onset cannabis smokers at an increased risk of depression spells?

PubMed

Fairman, Brian J; Anthony, James C

2012-04-01

A recent research focus is a set of hypothesized adult-onset mental health disturbances possibly due to early-onset cannabis use (EOCU, onset <18 years). We seek to estimate the suspected EOCU-associated excess odds of experiencing an incident depression spell during adulthood, with comparisons to never cannabis smokers and those with delayed cannabis onset (i.e., not starting to smoke cannabis until adulthood). The National Surveys on Drug Use and Health (NSDUH) assess non-institutionalized community-dwelling residents of the United States after probability sampling each year. In aggregate, the NSDUH analytical sample included 173,775 adult participants from survey years 2005-2009 (74-76% of designated respondents). Standardized computer-assisted interviews collected information on background determinants, age of first cannabis use, and depression spell onset. Logistic regression was used to estimate EOCU-depression spell associations in the form of odds ratios, with statistical adjustment for sex, age, race/ethnicity, years of cannabis involvement, tobacco cigarette onset, and alcohol onset. About 1 in 10 experienced a depression spell during adulthood, and both early-onset and adult-onset cannabis smokers had a modest excess odds of a depression spell compared to never cannabis smokers, even with covariate adjustment (OR=1.7 and 1.8, respectively; both p<0.001). Estimates for early- and adult-onset cannabis smokers did not statistically differ from one another. Shared diathesis that might influence both EOCU and adult-onset depression spell is controlled no more than partially, as will be true until essentially all known early-life shared vulnerabilities are illuminated. Cannabis smoking initiated at any age signals a modest increased risk of a spell of depression in adulthood, even when adjusted for suspected confounding variables studied here. Delaying cannabis onset until adulthood does not appear to diminish the cannabis-associated risk. Copyright © 2011

Are early-onset cannabis smokers at an increased risk of depression spells?

PubMed Central

Fairman, Brian J.; Anthony, James C.

2012-01-01

Background A recent research focus is a set of hypothesized adult-onset mental health disturbances possibly due to early-onset cannabis use (EOCU, onset <18 years). We seek to estimate the suspected EOCU-associated excess odds of experiencing an incident depression spell during adulthood, with comparisons to never cannabis smokers and those with delayed cannabis onset (i.e., not starting to smoke cannabis until adulthood). Methods The National Surveys on Drug Use and Health (NSDUH) assess non-institutionalized community-dwelling residents of the United States after probability sampling each year. In aggregate, the NSDUH analytical sample included 173,775 adult participants from survey years 2005–2009 (74–76% of designated respondents). Standardized computer-assisted interviews collected information on background determinants, age of first cannabis use, and depression spell onset. Logistic regression was used to estimate EOCU-depression spell associations in the form of odds ratios, with statistical adjustment for sex, age, race/ethnicity, years of cannabis involvement, tobacco cigarette onset, and alcohol onset. Results About 1 in 10 experienced a depression spell during adulthood, and both early-onset and adult-onset cannabis smokers had a modest excess odds of a depression spell compared to never cannabis smokers, even with covariate adjustment (OR = 1.7 & 1.8, respectively; both p<0.001). Estimates for early- and adult-onset cannabis smokers did not statistically differ from one another. Limitations Shared diathesis that might influence both EOCU and adult-onset depression spell is controlled no more than partially, as will be true until essentially all known early-life shared vulnerabilities are illuminated. Conclusion Cannabis smoking initiated at any age signals a modest increased risk of a spell of depression in adulthood, even when adjusted for suspected confounding variables studied here. Delaying cannabis onset until adulthood does not appear to

Increased brain injury and vascular leakage after pretreatment with p38-inhibitor SB203580 in transient ischemia.

PubMed

Lennmyr, F; Ericsson, A; Gerwins, P; Ahlström, H; Terént, A

2003-11-01

Focal cerebral ischemia activates intracellular signaling pathways including the mitogen-activated protein kinase p38, which may be involved in the process of ischemic brain injury. In this study, the effect of pretreatment with the p38-inhibitor SB203580 on infarct size and blood-brain barrier (BBB) breakdown was investigated with magnetic resonance imaging (MRI). Rats were given SB203580 (n = 6) or vehicle (n = 6) in the right lateral ventricle prior to transient (90 min) middle cerebral artery occlusion (MCAO) on the left side. The rats were examined with serial MRI during MCAO, at reperfusion and after 1 and 4 days. The mean infarct size on T2-weighted images after 1 day was significantly higher in the SB203580-treated group than in controls (300 +/- 95 mm3 vs 126 +/- 75 mm3; P < 0.01). Vascular gadolinium leakage, indicating BBB breakdown, was significantly larger in the SB203580-treated group than in controls after 1 day (median leakage score 18.5; range 15-21 vs 6.5; 4-17; P < 0.05) and 4 days (11; 6-15 vs 3.5; 1-9; P < 0.05), although no significant difference was seen initially. Pretreatment with SB203580 may aggravate ischemic brain injury and cerebral vascular leakage in the present model of transient ischemia.

The bomb 14C transient in the Pacific Ocean

NASA Astrophysics Data System (ADS)

Rodgers, Keith B.; Schrag, Daniel P.; Cane, Mark A.; Naik, Naomi H.

2000-04-01

A modeling study of the bomb 14C transient is presented for the Pacific Ocean. A primitive equation ocean circulation model has been configured for a high-resolution domain that accounts for the Indonesian Throughflow (ITF). Four separate runs were performed: (1) seasonal forcing with 20 Sv of ITF transport, (2) seasonal forcing with 10 Sv of ITF transport, (3) seasonal forcing with no ITF transport, and (4) interannual forcing with 15 Sv of ITF transport. This study has two main objectives. First, it is intended to describe the time evolution of the bomb 14C transient. This serves as a tool with which one can identify the physical processes controlling the evolving bomb 14C distribution in the Pacific thermocline and thus provides an interpretive framework for the database of Δ14C measurements in the Pacific. Second, transient tracers are applied to the physical oceanographic problem of intergyre exchange. This is of importance in furthering our understanding of the potential role of the upper Pacific Ocean in climate variability. We use bomb 14C as a dye tracer of intergyre exchange between the subtropical gyres and the equatorial upwelling regions of the equatorial Pacific. Observations show that while the atmospheric Δ14C signal peaked in the early to mid-1960s, the Δ14C levels in the surface water waters of the subtropical gyres peaked near 1970, and the Δ14C of surface waters in the equatorial Pacific continued to rise through the 1980s. It is shown that the model exhibits skill in representing the large-scale observed features observed for the bomb 14C transient in the Pacific Ocean. The model successfully captures the basin-scale inventories of bomb 14C in the tropics as well as in the extratropics of the North Pacific. For the equatorial Pacific this is attributed to the model's high meridional resolution. The discrepancies in the three-dimensional distribution of bomb 14C between the model and data are discussed within the context of the dynamical

Increased salt intake during early ontogenesis lead to development of arterial hypertension in salt-resistant Wistar rats.

PubMed

Svitok, Pavel; Molcan, Lubos; Vesela, Anna; Kruzliak, Peter; Moravcik, Roman; Zeman, Michal

2015-01-01

A direct relationship exists between salt consumption and hypertension. Increased sodium intake does not automatically lead to a rise in blood pressure (BP) because of marked intra-individual variability in salt sensitivity. Wistar rats are a salt-resistant strain and increased salt intake in adults does not induce hypertension. Mechanisms regulating BP develop during early ontogenesis and increased sodium consumption by pregnant females leads to an increase in BP of their offspring, but early postnatal stages have not been sufficiently analyzed in salt-resistant strains of rats. The aim of this work was to study the effects of increased salt during early ontogeny on cardiovascular characteristics of Wistar rats. We used 16 control (C; 8 males + 8 females) rats fed with a standard diet (0.2% sodium) and 16 experimental (S; 8 males + 8 females) rats fed with a diet containing 0.8% sodium. BP was measured weekly and plasma renin activity, aldosterone and testosterone concentrations were assayed by radioimmunoassay after the experiment in 16-week-old animals. In the kidney, AT1 receptors were determined by the western blot. BP was higher in the S as compared with the C rats and did not differ between males and females. The relative left ventricle mass was increased in S as compared with C males and no differences were recorded in females. No significant differences between groups were found in hormonal parameters and AT1 receptors. Results indicate that moderately increased salt intake during postnatal ontogeny results in a BP rise even in salt-resistant rats.

Transient thermal characteristics of high-temperature SiC power module enhanced with Al-bump technology

NASA Astrophysics Data System (ADS)

Tanisawa, Hidekazu; Kato, Fumiki; Koui, Kenichi; Sato, Shinji; Watanabe, Kinuyo; Takahashi, Hiroki; Murakami, Yoshinori; Sato, Hiroshi

2018-04-01

In this paper, we demonstrate a mounting technology that improves the tolerance to transient power loss by adding a heat capacity near the device. Silicon carbide (SiC) power devices can operate at high temperatures, up to 250 °C, at which silicon (Si) power devices cannot. Therefore, it is possible to allow a large temperature difference between the device and ambient air. Thus, the size of a power converter equipped with an SiC power module is reduced by simplifying the cooling system. The temperature of the power module is important not only in the steady state, but in transient loads as well. Therefore, we developed the Al-bump flip-chip mounting technology to increase heat capacity near the device. With this proposed structure, the heat capacity per device increased by 1.7% compared with the total heat capacity of the conventional structure using wire bonding. The reduction in transient thermal impedance is observed from 0.003 to 3 s, and we confirmed that the transient thermal impedance is reduced very efficiently by 15% at the maximum, compared with the conventional structure.

The effect of Platelet Lysate on osteoblast proliferation associated with a transient increase of the inflammatory response in bone regeneration.

PubMed

Ruggiu, Alessandra; Ulivi, Valentina; Sanguineti, Francesca; Cancedda, Ranieri; Descalzi, Fiorella

2013-12-01

Platelet Lysate (PL) contains a cocktail of growth factors and cytokines, which actively participates in tissue repair and its clinical application has been broadly described. The aim of this study was to assess the regenerative potential of PL for bone repair. We demonstrated that PL stimulation induces a transient increase of the inflammatory response in quiescent human osteoblasts, via NF-kB activation, COX-2 induction, PGE2 production and secretion of pro-inflammatory cytokines. Furthermore, we showed that long-term PL stimulation enhances proliferation of actively replicating osteoblasts, without affecting their differentiation potential, along with changes of cell morphology, resulting in increased cell density at confluence. In confluent resting osteoblasts, PL treatment induced resumption of proliferation, change in cell morphology and increase of cell density at confluence. A burst of PL treatment (24-h) was sufficient to trigger such processes in both conditions. These results correlated with up-regulation of the proliferative and survival pathways ERKs and Akt and with cell cycle re-activation via induction of CyclinD1 and phosphorylation of Rb, following PL stimulation. Our findings demonstrate that PL treatment results in activation and expansion of resting osteoblasts, without affecting their differentiation potential. Therefore PL represents a good therapeutic candidate in regenerative medicine for bone repair. Copyright © 2013 Elsevier Ltd. All rights reserved.

Association Between Increased Vascular Density and Loss of Protective RAS in Early-stage NPDR

NASA Technical Reports Server (NTRS)

Radhakrishnan, Krishnan; Raghunandan, Sneha; Vyas, Ruchi J.; Vu, Amanda C.; Bryant, Douglas; Yaqian, Duan; Knecht, Brenda E.; Grant, Maria B.; Chalam, K. V.; Parsons-Wingerter, Patricia

2016-01-01

Our hypothesis predicts that retinal blood vessels increase in density during early-stage progression to moderate nonproliferative diabetic retinopathy (NPDR). The renin-angiotensin system (RAS) is implicated in the pathogenesis of DR and in the function of circulating angiogenic cells (CACs), a critical bone marrow-derived population that is instrumental in vascular repair.

Integrated transient thermal-structural finite element analysis

NASA Technical Reports Server (NTRS)

Thornton, E. A.; Dechaumphai, P.; Wieting, A. R.; Tamma, K. K.

1981-01-01

An integrated thermal structural finite element approach for efficient coupling of transient thermal and structural analysis is presented. Integrated thermal structural rod and one dimensional axisymmetric elements considering conduction and convection are developed and used in transient thermal structural applications. The improved accuracy of the integrated approach is illustrated by comparisons with exact transient heat conduction elasticity solutions and conventional finite element thermal finite element structural analyses.

Species-driven phases and increasing structure in early-successional plant communities.

PubMed

Zaplata, Markus K; Winter, Susanne; Fischer, Anton; Kollmann, Johannes; Ulrich, Werner

2013-01-01

Successional phases describe changes in ecological communities that proceed in steps rather than continuously. Despite their importance for the understanding of ecosystem development, there still exists no reliable definition of phases and no quantitative measure of phase transitions. In order to obtain these data, we investigated primary succession in an artificial catchment (6 ha) in eastern Germany over a period of 6 years. The data set consists of records of plant species and their cover values, and initial substrate properties, both from plots in a regular grid (20 m × 20 m) suitable for spatial data analysis. Community assembly was studied by analyses of species co-occurrence and nestedness. Additionally, we correlated lognormal and log series distributions of species abundance to each community. We here introduce a new general method for detection of successional phases based on the degree of transient spatial homogeneity in the study system. Spatially coherent vegetation patterns revealed nonoverlapping partitions within this sequence of primary succession and were characterized as two distinct ecological phases. Patterns of species co-occurrence were increasingly less random, and hence the importance of demographic stochasticity and neutral community assembly decreased during the study period. Our findings highlight the spatial dimension of successional phases and quantify the degree of change between these steps. They are an element for advancing a more reliable terminology of ecological successions.

Transient and persistent worsening renal function during hospitalization for acute heart failure.

PubMed

Krishnamoorthy, Arun; Greiner, Melissa A; Sharma, Puza P; DeVore, Adam D; Johnson, Katherine Waltman; Fonarow, Gregg C; Curtis, Lesley H; Hernandez, Adrian F

2014-12-01

Transient and persistent worsening renal function (WRF) may be associated with different risks during hospitalization for acute heart failure. We compared outcomes of patients hospitalized for acute heart failure with transient, persistent, or no WRF. We identified patients 65 years or older hospitalized with acute heart failure from a clinical registry linked to Medicare claims data. We defined WRF as an increase in serum creatinine of ≥ 0.3 mg/dL after admission. We further classified patients with WRF by the difference between admission and last recorded serum creatinine levels into transient WRF (< 0.3 mg/dL) or persistent WRF (≥ 0.3 mg/dL). We examined unadjusted rates and adjusted associations between 90-day outcomes and WRF status. Among 27,309 patients, 18,568 (68.0%) had no WRF, 3,205 (11.7%) had transient WRF, and 5,536 (20.3%) had persistent WRF. Patients with WRF had higher observed rates of 90-day postdischarge all-cause readmission and 90-day postadmission mortality (P < .001). After multivariable adjustment, transient WRF (hazard ratio [HR] 1.19, 99% CI 1.05-1.35) and persistent WRF (HR 1.73, 99% CI 1.57-1.91) were associated with higher risks of 90-day postadmission mortality (P < .001 for both). Compared with transient WRF, persistent WRF was associated with a higher risk of 90-day postadmission mortality (HR 1.46, 99% CI 1.28-1.66, P < .001). Transient and persistent WRF during hospitalization for acute heart failure were associated with higher adjusted risks for 90-day all-cause postadmission mortality. Patients with persistent WRF had worse outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

SCAT Classification of 4 Optical Transients

NASA Astrophysics Data System (ADS)

Tucker, Michael A.; Rowan, Dominick M.; Shappee, Benjamin J.; Dong, Subo; Bose, Subhash; Stanek, K. Z.

2018-06-01

The Spectral Classification of Astronomical Transients (SCAT) survey (ATel #11444) presents the classification of 4 optical transients. We report optical spectroscopy (330-970nm) taken with the University of Hawaii 88-inch (UH88) telescope using the SuperNova Integral Field Spectrograph (SNIFS).

Search for transient gravitational waves in coincidence with short-duration radio transients during 2007-2013

NASA Astrophysics Data System (ADS)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Holz, D. E.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Islas, G.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, K.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J.; Kim, K.; Kim, Nam-Gyu; Kim, Namjun; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Kokeyama, K.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B. M.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Logue, J.; Lombardi, A. L.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lück, H.; Lundgren, A. P.; Luo, J.; Lynch, R.; Ma, Y.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R. M.; Mageswaran, M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mendoza-Gandara, D.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, K. N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nedkova, K.; Nelemans, G.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Pereira, R.; Perreca, A.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Ricci, F.; Riles, K.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Setyawati, Y.; Sevigny, A.; Shaddock, D. A.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stiles, D.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D. J.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Wright, J. L.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, F.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; Archibald, A. M.; Banaszak, S.; Berndsen, A.; Boyles, J.; Cardoso, R. F.; Chawla, P.; Cherry, A.; Dartez, L. P.; Day, D.; Epstein, C. R.; Ford, A. J.; Flanigan, J.; Garcia, A.; Hessels, J. W. T.; Hinojosa, J.; Jenet, F. A.; Karako-Argaman, C.; Kaspi, V. M.; Keane, E. F.; Kondratiev, V. I.; Kramer, M.; Leake, S.; Lorimer, D.; Lunsford, G.; Lynch, R. S.; Martinez, J. G.; Mata, A.; McLaughlin, M. A.; McPhee, C. A.; Penucci, T.; Ransom, S.; Roberts, M. S. E.; Rohr, M. D. W.; Stairs, I. H.; Stovall, K.; van Leeuwen, J.; Walker, A. N.; Wells, B. L.; LIGO Scientific Collaboration; Virgo Collaboration

2016-06-01

We present an archival search for transient gravitational-wave bursts in coincidence with 27 single-pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo, and GEO interferometer network. We also discuss a check for gravitational-wave signals in coincidence with Parkes fast radio bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short-duration radio signals and transient gravitational-wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational-wave emission in coincidence with these radio transients was found, the current analysis serves as a prototype for similar future searches using more sensitive second-generation interferometers.

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.

Single Event Transients in Linear Integrated Circuits

NASA Technical Reports Server (NTRS)

Buchner, Stephen; McMorrow, Dale

2005-01-01

On November 5, 2001, a processor reset occurred on board the Microwave Anisotropy Probe (MAP), a NASA mission to measure the anisotropy of the microwave radiation left over from the Big Bang. The reset caused the spacecraft to enter a safehold mode from which it took several days to recover. Were that to happen regularly, the entire mission would be compromised, so it was important to find the cause of the reset and, if possible, to mitigate it. NASA assembled a team of engineers that included experts in radiation effects to tackle the problem. The first clue was the observation that the processor reset occurred during a solar event characterized by large increases in the proton and heavy ion fluxes emitted by the sun. To the radiation effects engineers on the team, this strongly suggested that particle radiation might be the culprit, particularly when it was discovered that the reset circuit contained three voltage comparators (LM139). Previous testing revealed that large voltage transients, or glitches appeared at the output of the LM139 when it was exposed to a beam of heavy ions [NI96]. The function of the reset circuit was to monitor the supply voltage and to issue a reset command to the processor should the voltage fall below a reference of 2.5 V [PO02]. Eventually, the team of engineers concluded that ionizing particle radiation from the solar event produced a negative voltage transient on the output of one of the LM139s sufficiently large to reset the processor on MAP. Fortunately, as of the end of 2004, only two such resets have occurred. The reset on MAP was not the first malfunction on a spacecraft attributed to a transient. That occurred shortly after the launch of NASA s TOPEX/Poseidon satellite in 1992. It was suspected, and later confirmed, that an anomaly in the Earth Sensor was caused by a transient in an operational amplifier (OP-15) [KO93]. Over the next few years, problems on TDRS, CASSINI, [PR02] SOHO [HA99,HA01] and TERRA were also attributed

Pre-treatment with Chrysanthemum indicum Linné extract protects pyramidal neurons from transient cerebral ischemia via increasing antioxidants in the gerbil hippocampal CA1 region

PubMed Central

Kim, In Hye; Lee, Tae-Kyeong; Cho, Jeong Hwi; Lee, Jae-Chul; Park, Joon Ha; Ahn, Ji Hyeon; Shin, Bich-Na; Chen, Bai Hui; Tae, Hyun-Jin; Kim, Yang Hee; Kim, Jong-Dai; Kim, Young-Myeong; Won, Moo-Ho; Kang, Il Jun

2017-01-01

Chrysanthemum indicum Linné extract (CIL) is used in herbal medicine in East Asia. In the present study, gerbils were orally pre-treated with CIL, and changes of antioxidant enzymes including superoxide dismutase (SOD) 1 and SOD2, catalase (CAT) and glutathione peroxidase (GPX) in the hippocampal CA1 region following 5 min of transient cerebral ischemia were investigated and the neuroprotective effect of CIL in the ischemic CA1 region was examined. SOD1, SOD2, CAT and GPX immunoreactivities were observed in the pyramidal cells of the CA1 region and their immunoreactivities were gradually decreased following ischemia-reperfusion and barely detectable at 5 days post-ischemia. CIL pre-treatment significantly increased immunoreactivities of SOD1, CAT and GPX, but not SOD2, in the CA1 pyramidal cells of the sham-operated animals. In addition, SOD1, SOD2, CAT and GPX immunoreactivities in the CA1 pyramidal cells were significantly higher compared with the ischemia-operated animals. Furthermore, it was identified that pre-treatment with CIL protected the CA1 pyramidal cells in the CA1 region using neuronal nuclei immunohistochemistry and Fluoro-Jade B histofluorescence staining; the protected CA1 pyramidal cells were 67.5% compared with the sham-operated animals. In conclusion, oral CIL pre-treatment increased endogenous antioxidant enzymes in CA1 pyramidal cells in the gerbil hippocampus and protected the cells from transient cerebral ischemic insult. This finding suggested that CIL is promising for the prevention of ischemia-induced neuronal damage. PMID:28534982

Transient atomic behavior and surface kinetics of GaN

NASA Astrophysics Data System (ADS)

Moseley, Michael; Billingsley, Daniel; Henderson, Walter; Trybus, Elaissa; Doolittle, W. Alan

2009-07-01

An in-depth model for the transient behavior of metal atoms adsorbed on the surface of GaN is developed. This model is developed by qualitatively analyzing transient reflection high energy electron diffraction (RHEED) signals, which were recorded for a variety of growth conditions of GaN grown by molecular-beam epitaxy (MBE) using metal-modulated epitaxy (MME). Details such as the initial desorption of a nitrogen adlayer and the formation of the Ga monolayer, bilayer, and droplets are monitored using RHEED and related to Ga flux and shutter cycles. The suggested model increases the understanding of the surface kinetics of GaN, provides an indirect method of monitoring the kinetic evolution of these surfaces, and introduces a novel method of in situ growth rate determination.

Spectroscopic Classifications of Optical Transients with Mayall/KOSMOS

NASA Astrophysics Data System (ADS)

Pan, Y.-C.; Downing, S.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

2016-01-01

We report the following classifications of optical transients from spectroscopic observations with the KOSMOS on the Mayall telescope. Targets were supplied by the All-Sky Automated Survey for Supernovae (ASAS-SN), Catalina Real-Time Transient Survey (CRTS) and the CBAT Transient Object Followup Reports.

Synchronizing noisy nonidentical oscillators by transient uncoupling

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

Tandon, Aditya, E-mail: adityat@iitk.ac.in; Mannattil, Manu, E-mail: mmanu@iitk.ac.in; Schröder, Malte, E-mail: malte@nld.ds.mpg.de

2016-09-15

Synchronization is the process of achieving identical dynamics among coupled identical units. If the units are different from each other, their dynamics cannot become identical; yet, after transients, there may emerge a functional relationship between them—a phenomenon termed “generalized synchronization.” Here, we show that the concept of transient uncoupling, recently introduced for synchronizing identical units, also supports generalized synchronization among nonidentical chaotic units. Generalized synchronization can be achieved by transient uncoupling even when it is impossible by regular coupling. We furthermore demonstrate that transient uncoupling stabilizes synchronization in the presence of common noise. Transient uncoupling works best if the unitsmore » stay uncoupled whenever the driven orbit visits regions that are locally diverging in its phase space. Thus, to select a favorable uncoupling region, we propose an intuitive method that measures the local divergence at the phase points of the driven unit's trajectory by linearizing the flow and subsequently suppresses the divergence by uncoupling.« less

Transient simulation of molten salt central receiver

NASA Astrophysics Data System (ADS)

Doupis, Dimitri; Wang, Chuan; Carcorze-Soto, Jorge; Chen, Yen-Ming; Maggi, Andrea; Losito, Matteo; Clark, Michael

2016-05-01

Alstom is developing concentrated solar power (CSP) utilizing 60/40wt% NaNO3-KNO3 molten salt as the working fluid in a tower receiver for the global renewable energy market. In the CSP power generation cycle, receivers undergo a daily cyclic operation due to the transient nature of solar energy. Development of robust and efficient start-up and shut-down procedures is critical to avoiding component failures due to mechanical fatigue resulting from thermal transients, thus maintaining the performance and availability of the CSP plant. The Molten Salt Central Receiver (MSCR) is subject to thermal transients during normal daily operation, a cycle that includes warmup, filling, operation, draining, and shutdown. This paper describes a study to leverage dynamic simulation and finite element analysis (FEA) in development of start-up, shutdown, and transient operation concepts for the MSCR. The results of the FEA also verify the robustness of the MSCR design to the thermal transients anticipated during the operation of the plant.

Free Trehalose Accumulation in Dormant Mycobacterium smegmatis Cells and Its Breakdown in Early Resuscitation Phase

PubMed Central

Shleeva, Margarita O.; Trutneva, Kseniya A.; Demina, Galina R.; Zinin, Alexander I.; Sorokoumova, Galina M.; Laptinskaya, Polina K.; Shumkova, Ekaterina S.; Kaprelyants, Arseny S.

2017-01-01

Under gradual acidification of growth medium resulting in the formation of dormant Mycobacterium smegmatis, a significant accumulation of free trehalose in dormant cells was observed. According to 1H- and 13C-NMR spectroscopy up to 64% of total organic substances in the dormant cell extract was represented by trehalose whilst the trehalose content in an extract of active cells taken from early stationary phase was not more than 15%. Trehalose biosynthesis during transition to the dormant state is provided by activation of genes involved in the OtsA-OtsB and TreY-TreZ pathways (according to RT-PCR). Varying the concentration of free trehalose in dormant cells by expression of MSMEG_4535 coding for trehalase we found that cell viability depends on trehalose level: cells with a high amount of trehalose survive much better than cells with a low amount. Upon resuscitation of dormant M. smegmatis, a decrease of free trehalose and an increase in glucose concentration occurred in the early period of resuscitation (after 2 h). Evidently, breakdown of trehalose by trehalase takes place at this time as a transient increase in trehalase activity was observed between 1 and 3 h of resuscitation. Activation of trehalase was not due to de novo biosynthesis but because of self-activation of the enzyme from the inactive state in dormant cells. Because, even a low concentration of ATP (2 mM) prevents self-activation of trehalase in vitro and after activation the enzyme is still sensitive to ATP we suggest that the transient character of trehalase activation in cells is due to variation in intracellular ATP concentration found in the early resuscitation period. The negative influence of the trehalase inhibitor validamycin A on the resuscitation of dormant cells proves the importance of trehalase for resuscitation. These experiments demonstrate the significance of free trehalose accumulation for the maintenance of dormant mycobacterial viability and the involvement of trehalose

Transient hypothyroidism after iodine-131 therapy for Grave's disease.

PubMed

Gómez, N; Gómez, J M; Orti, A; Gavaldà, L; Villabona, C; Leyes, P; Soler, J

1995-09-01

We studied 355 patients with Grave's disease to characterize transient hypothyroidism and its prognostic value following 131I therapy. The patients received therapeutic 131I treatment as follows: 333 received a dose < 10 mCi (6.6 +/- 1.9 mCi) and 22 received a dose > 10 mCi (12.8 +/- 2.9 mCi). Diagnosis of transient hypothyroidism was based on low T4, regardless of TSH within the first year after 131I followed by recovery of T4 and normal TSH. After administration of < 10 mCi 131I, 40 patients developed transient hypothyroidism during the first year; transient hypothyroidism was symptomatic in 15. There was no transient hypothyroidism after high doses (> 10 mCi) of 131I. Iodine-131 uptake > 70% at 2 hr before treatment was a risk factor for developing transient hypothyroidism (Odds ratio 2.8, 95% confidence interval 0.9-9.4). At diagnosis of transient hypothyroidism, basal TSH levels were high (51%), normal (35%) or low (14%); therefore, the transient hypothyroidism was not centralized. If hypothyroidism developed during the first 6 mo after basal TSH > 45 mU/liter ruled out transient hypothyroidism. The development of transient hypothyroidism and its hormonal pattern did not influence long-term thyroid function. Since no prognostic factors reliably predicted transient hypothyroidism before 131I or at the time of diagnosis, if hypothyroidism appears within the first months after 131I, the reevaluation of thyroid function later is warranted to avoid unnecessary chronic replacement therapy.

Supra- and Sub-Baseline Phosphocreatine Recovery in Developing Brain after Transient Hypoxia-Ischaemia: Relation to Baseline Energetics, Insult Severity and Outcome

ERIC Educational Resources Information Center

Iwata, Osuke; Iwata, Sachiko; Bainbridge, Alan; De Vita, Enrico; Matsuishi, Toyojiro; Cady, Ernest B.; Robertson, Nicola J.

2008-01-01

Following hypoxia-ischaemia (HI), an early biomarker of insult severity is desirable to target neuroprotective therapies to patients most likely to benefit; currently there are no biomarkers within the "latent phase" period before the establishment of secondary energy failure. Brief transient phosphocreatine (PCr) recovery overshoot (measured…

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.

Transient loads analysis for space flight applications

NASA Technical Reports Server (NTRS)

Thampi, S. K.; Vidyasagar, N. S.; Ganesan, N.

1992-01-01

A significant part of the flight readiness verification process involves transient analysis of the coupled Shuttle-payload system to determine the low frequency transient loads. This paper describes a methodology for transient loads analysis and its implementation for the Spacelab Life Sciences Mission. The analysis is carried out using two major software tools - NASTRAN and an external FORTRAN code called EZTRAN. This approach is adopted to overcome some of the limitations of NASTRAN's standard transient analysis capabilities. The method uses Data Recovery Matrices (DRM) to improve computational efficiency. The mode acceleration method is fully implemented in the DRM formulation to recover accurate displacements, stresses, and forces. The advantages of the method are demonstrated through a numerical example.

Semantic acquisition without memories: evidence from transient global amnesia.

PubMed

Guillery, B; Desgranges, B; Katis, S; de la Sayette, V; Viader, F; Eustache, F

2001-12-04

Transient global amnesia (TGA), characterised by a profound anterograde amnesia, is a model of interest to study the acquisition of novel meanings independent of episodic functioning. Three patients were tested during a TGA attack, two in the early recovery phase and the third during the acute phase of TGA, with a semantic priming task involving a restructuring process of conceptual knowledge. During TGA, all patients demonstrated priming effects. Results obtained the day after the episode with the same task showed that these effects persisted at least one day. Episodic memory seems not to be critical for the formation of novel connections among unrelated semantic representations, in accordance with Tulving's model of memory, i.e. episodic memory is not necessary for the acquisition of semantic information.

Variations in surface water-ground water interactions along a headwater mountain stream : comparisons between transient storage and water balance analyses

USGS Publications Warehouse

Ward, Adam S.; Payn, Robert A.; Gooseff, Michael N.; McGlynn, Brian L.; Bencala, Kenneth E.; Kelleher, Christa A.; Wondzell, Steven M.; Wagener, Thorsten

2013-01-01

The accumulation of discharge along a stream valley is frequently assumed to be the primary control on solute transport processes. Relationships of both increasing and decreasing transient storage, and decreased gross losses of stream water have been reported with increasing discharge; however, we have yet to validate these relationships with extensive field study. We conducted transient storage and mass recovery analyses of artificial tracer studies completed for 28 contiguous 100 m reaches along a stream valley, repeated under four base-flow conditions. We calculated net and gross gains and losses, temporal moments of tracer breakthrough curves, and best fit transient storage model parameters (with uncertainty estimates) for 106 individual tracer injections. Results supported predictions that gross loss of channel water would decrease with increased discharge. However, results showed no clear relationship between discharge and transient storage, and further analysis of solute tracer methods demonstrated that the lack of this relation may be explained by uncertainty and equifinality in the transient storage model framework. Furthermore, comparison of water balance and transient storage approaches reveals complications in clear interpretation of either method due to changes in advective transport time, which sets a the temporal boundary separating transient storage and channel water balance. We have little ability to parse this limitation of solute tracer methods from the physical processes we seek to study. We suggest the combined analysis of both transient storage and channel water balance more completely characterizes transport of solutes in stream networks than can be inferred from either method alone.

The relationship between transient and persistent worsening renal function and mortality in patients with acute decompensated heart failure.

PubMed

Aronson, Doron; Burger, Andrew J

2010-07-01

Worsening renal function (WRF) is an ominous complication in patients with acute heart failure syndrome (AHFS). Few data are available with regard to the clinical implications of transient versus persistent WRF in this setting. We studied 467 patients with AHFS and creatinine measurements at baseline and on days 2, 5, 14, and 30. WRF (>/= 0.5 mg/dL increase in serum creatinine above baseline at any time point) was defined as persistent when serum creatinine remained >/= 0.5 mg/dL above baseline throughout day 30, and transient when creatinine levels subsequently decreased to < 0.5 mg/dL above baseline. WRF occurred in 115 patients, and was transient in 39 patients (33.9%). The 6-month mortality rates were 17.3%, 20.5%, and 46.1% in patients without WRF, transient WRF, and persistent WRF, respectively. In a multivariable Cox model, compared with patients with stable renal function, the adjusted hazard ratio for mortality was 0.8 (95% CI 0.4-1.7; P = .58) in patients with transient WRF and 3.2 (95% CI 2.1-5.0; P < .0001) in patients with persistent WRF. Transient WRF is frequent among patients with AHFS. Whereas persistent WRF portends increased mortality, transient WRF appears to be associated with a better outcome as compared with persistent renal failure. Copyright 2010 Elsevier Inc. All rights reserved.

Increased error-related thalamic activity during early compared to late cocaine abstinence.

PubMed

Li, Chiang-Shan R; Luo, Xi; Sinha, Rajita; Rounsaville, Bruce J; Carroll, Kathleen M; Malison, Robert T; Ding, Yu-Shin; Zhang, Sheng; Ide, Jaime S

2010-06-01

Altered cognitive control is implicated in the shaping of cocaine dependence. One of the key component processes of cognitive control is error monitoring. Our previous imaging work highlighted greater activity in distinct cortical and subcortical regions including the dorsal anterior cingulate cortex (dACC), thalamus and insula when participants committed an error during the stop signal task (Li et al., 2008b). Importantly, dACC, thalamic and insular activity has been associated with drug craving. One hypothesis is that the intense interoceptive activity during craving prevents these cerebral structures from adequately registering error and/or monitoring performance. Alternatively, the dACC, thalamus and insula show abnormally heightened responses to performance errors, suggesting that excessive responses to salient stimuli such as drug cues could precipitate craving. The two hypotheses would each predict decreased and increased activity during stop error (SE) as compared to stop success (SS) trials in the SST. Here we showed that cocaine dependent patients (PCD) experienced greater subjective feeling of loss of control and cocaine craving during early (average of day 6) compared to late (average of day 18) abstinence. Furthermore, compared to PCD during late abstinence, PCD scanned during early abstinence showed increased thalamic as well as insular but not dACC responses to errors (SE>SS). These findings support the hypothesis that heightened thalamic reactivity to salient stimuli co-occur with cocaine craving and loss of self control. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Increased expression of neutrophil-related genes in patients with early sepsis-induced ARDS.

PubMed

Kangelaris, Kirsten Neudoerffer; Prakash, Arun; Liu, Kathleen D; Aouizerat, Bradley; Woodruff, Prescott G; Erle, David J; Rogers, Angela; Seeley, Eric J; Chu, Jeffrey; Liu, Tom; Osterberg-Deiss, Thomas; Zhuo, Hanjing; Matthay, Michael A; Calfee, Carolyn S

2015-06-01

The early sequence of events leading to the development of the acute respiratory distress syndrome (ARDS) in patients with sepsis remains inadequately understood. The purpose of this study was to identify changes in gene expression early in the course of illness, when mechanisms of injury may provide the most relevant treatment and prognostic targets. We collected whole blood RNA in critically ill patients admitted from the Emergency Department to the intensive care unit within 24 h of admission at a tertiary care center. Whole genome expression was compared in patients with sepsis and ARDS to patients with sepsis alone. We selected genes with >1 log2 fold change and false discovery rate <0.25, determined their significance in the literature, and performed pathway analysis. Several genes were upregulated in 29 patients with sepsis with ARDS compared with 28 patients with sepsis alone. The most differentially expressed genes included key mediators of the initial neutrophil response to infection: olfactomedin 4, lipocalin 2, CD24, and bactericidal/permeability-increasing protein. These gene expression differences withstood adjustment for age, sex, study batch, white blood cell count, and presence of pneumonia or aspiration. Pathway analysis demonstrated overrepresentation of genes involved in known respiratory and infection pathways. These data indicate that several neutrophil-related pathways may be involved in the early pathogenesis of sepsis-related ARDS. In addition, identifiable gene expression differences occurring early in the course of sepsis-related ARDS may further elucidate understanding of the neutrophil-related mechanisms in progression to ARDS. Copyright © 2015 the American Physiological Society.

Increased expression of neutrophil-related genes in patients with early sepsis-induced ARDS

PubMed Central

Prakash, Arun; Liu, Kathleen D.; Aouizerat, Bradley; Woodruff, Prescott G.; Erle, David J.; Rogers, Angela; Seeley, Eric J.; Chu, Jeffrey; Liu, Tom; Osterberg-Deiss, Thomas; Zhuo, Hanjing; Matthay, Michael A.; Calfee, Carolyn S.

2015-01-01

The early sequence of events leading to the development of the acute respiratory distress syndrome (ARDS) in patients with sepsis remains inadequately understood. The purpose of this study was to identify changes in gene expression early in the course of illness, when mechanisms of injury may provide the most relevant treatment and prognostic targets. We collected whole blood RNA in critically ill patients admitted from the Emergency Department to the intensive care unit within 24 h of admission at a tertiary care center. Whole genome expression was compared in patients with sepsis and ARDS to patients with sepsis alone. We selected genes with >1 log2 fold change and false discovery rate <0.25, determined their significance in the literature, and performed pathway analysis. Several genes were upregulated in 29 patients with sepsis with ARDS compared with 28 patients with sepsis alone. The most differentially expressed genes included key mediators of the initial neutrophil response to infection: olfactomedin 4, lipocalin 2, CD24, and bactericidal/permeability-increasing protein. These gene expression differences withstood adjustment for age, sex, study batch, white blood cell count, and presence of pneumonia or aspiration. Pathway analysis demonstrated overrepresentation of genes involved in known respiratory and infection pathways. These data indicate that several neutrophil-related pathways may be involved in the early pathogenesis of sepsis-related ARDS. In addition, identifiable gene expression differences occurring early in the course of sepsis-related ARDS may further elucidate understanding of the neutrophil-related mechanisms in progression to ARDS. PMID:25795726

Mechanism of transient force augmentation varying with two distinct timescales for interacting vortex rings

NASA Astrophysics Data System (ADS)

Fu, Zhidong; Qin, Suyang; Liu, Hong

2014-01-01

The dynamics of dual vortex ring flows is studied experimentally and numerically in a model system that consists of a piston-cylinder apparatus. The flows are generated by double identical strokes which have the velocity profile characterized by the sinusoidal function of half the period. By calculating the total wake impulse in two strokes in the experiments, it is found that the average propulsive force increases by 50% in the second stroke for the sufficiently small stroke length, compared with the first stroke. In the numerical simulations, two types of transient force augmentation are revealed, there being the transient force augmentation for the small stroke lengths and the absolute transient force augmentation for the large stroke lengths. The relative transient force augmentation increases to 78% for L/D = 1, while the absolute transient force augmentation for L/D = 4 is twice as much as that for L/D = 1. Further investigation demonstrates that the force augmentation is attributed to the interaction between vortex rings, which induces transport of vortex impulse and more evident fluid entrainment. The critical situation of vortex ring separation is defined and indicated, with vortex spacing falling in a narrow gap when the stroke lengths vary. A new model is proposed concerning the limiting process of impulse, further suggesting that apart from vortex formation timescale, vortex spacing should be interpreted as an independent timescale to reflect the dynamics of vortex interaction.

High ABCD2 Scores and In-Hospital Interventions following Transient Ischemic Attack

PubMed Central

Cutting, Shawna; Regan, Elizabeth; Lee, Vivien H.; Prabhakaran, Shyam

2016-01-01

Background and Purpose Following transient ischemic attack (TIA), there is increased risk for ischemic stroke. The American Heart Association recommends admission of patients with ABCD2 scores ≥3 for observation, rapid performance of diagnostic tests, and potential acute intervention. We aimed to determine if there is a relationship between ABCD2 scores, in-hospital ischemic events, and in-hospital treatments after TIA admission. Methods We reviewed consecutive patients admitted between 2006 and 2011 following a TIA, defined as transient focal neurological symptoms attributed to a specific vascular distribution and lasting <24 h. Three interventions were prespecified: anticoagulation for atrial fibrillation, carotid or intracranial revascularization, and intravenous or intra-arterial reperfusion therapies. We compared rates of in-hospital recurrent TIA or ischemic stroke and the receipt of interventions among patients with low (<3) versus high (≥3) ABCD2 scores. Results Of 249 patients, 11 patients (4.4%) had recurrent TIAs or strokes during their stay (8 TIAs, 3 strokes). All 11 had ABCD2 scores ≥3, and no neurological events occurred in patients with lower scores (5.1 vs. 0%; p = 0.37). Twelve patients (4.8%) underwent revascularization for large artery stenosis, 16 (6.4%) were started on anticoagulants, and no patient received intravenous or intra-arterial reperfusion therapy. The ABCD2 score was not associated with anticoagulation (p = 0.59) or revascularization (p = 0.20). Conclusions Higher ABCD2 scores may predict early ischemic events after TIA but do not predict the need for intervention. Outpatient evaluation for those with scores <3 would potentially have delayed revascularization or anticoagulant treatment in nearly one-fifth of ‘low-risk’ patients. PMID:27721312

Transient surface states during the CBE growth of GaAs

NASA Astrophysics Data System (ADS)

Farrell, T.; Hill, D.; Joyce, T. B.; Bullough, T. J.; Weightman, P.

1997-05-01

We report the occurrence of a transient surface state during the initial stages of CBE GaAs(0 0 1) growth. The state was detected in real-time reflectance ( R) and reflectance anisotropy spectroscopy (RAS) growth monitoring. At low growth rates, less than 1 μm/h, beam equivalent pressure (BEP) of triethylgallium (TEG) < 2.5 × 10 -5 mbar there was no change in R and the RAS signal changed from its pre-growth value under arsenic stabilisation at the growth temperature to its "during growth" value upon admission of the TEG, with the familiar monolayer oscillations. At higher TEG BEPs there was a rapid increase in R at all monitoring wavelengths, followed by a monotonic decay to its pre-growth value. This transient increase in R was accompanied by a change in the RAS signal, the magnitude and sign of which varied with wavelength. The initial increase in R is shown to be associated with the development of a metallic-like surface whereas the changes in the RAS signal are consistent with the formation of Ga dimers.

Developing Materials and Support for Early Childhood Educators To Increase Abilities To Become Effective Advocates.

ERIC Educational Resources Information Center

Robinson, Barbara J.

Because early childhood educators were minimally knowledgeable about and uninvolved in state legislative activities affecting their profession, an experienced child advocate developed a practicum to increase practitioners' knowledge and involvement. To attain practicum objectives, an advocacy handbook was developed and an advocacy project support…

Transient Cognitive Dynamics, Metastability, and Decision Making

PubMed Central

Rabinovich, Mikhail I.; Huerta, Ramón; Varona, Pablo; Afraimovich, Valentin S.

2008-01-01

The idea that cognitive activity can be understood using nonlinear dynamics has been intensively discussed at length for the last 15 years. One of the popular points of view is that metastable states play a key role in the execution of cognitive functions. Experimental and modeling studies suggest that most of these functions are the result of transient activity of large-scale brain networks in the presence of noise. Such transients may consist of a sequential switching between different metastable cognitive states. The main problem faced when using dynamical theory to describe transient cognitive processes is the fundamental contradiction between reproducibility and flexibility of transient behavior. In this paper, we propose a theoretical description of transient cognitive dynamics based on the interaction of functionally dependent metastable cognitive states. The mathematical image of such transient activity is a stable heteroclinic channel, i.e., a set of trajectories in the vicinity of a heteroclinic skeleton that consists of saddles and unstable separatrices that connect their surroundings. We suggest a basic mathematical model, a strongly dissipative dynamical system, and formulate the conditions for the robustness and reproducibility of cognitive transients that satisfy the competing requirements for stability and flexibility. Based on this approach, we describe here an effective solution for the problem of sequential decision making, represented as a fixed time game: a player takes sequential actions in a changing noisy environment so as to maximize a cumulative reward. As we predict and verify in computer simulations, noise plays an important role in optimizing the gain. PMID:18452000

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.

Detection of Northern Hemisphere Transient Baroclinic Eddies in REMS Pressure Data at Gale Crater Mars

NASA Astrophysics Data System (ADS)

Haberle, Robert; Kahre, Melinda A.; De la Torre, Manuel; Kass, David M.; Mars Science Laboratory Science Team

2016-10-01

Wintertime transient baroclinic eddies in the northern midlatitudes of Mars were identified in Viking Lander 2 (VL2, 48.3N, 134.0E) surface pressure data back in the early 1980s. Here we report the results of an analysis of REMS surface pressure data acquired by the Curiosity Rover in Gale Crater (4.5S, 137.4E) that suggests the meridional scale of these eddies is so large that the disturbances in the surface pressure fields they create extend across the equator and into the southern hemisphere. A power spectrum analysis of the seasonally detrended REMS pressure data from Ls=240-280 shows dominant periods of ~ 6 sols and ~2.2 sols (though with greatly reduced power) which are close the dominant periods of the transient eddies observed by VL2 at this season. Analysis of the surface pressure fields from the Ames Mars GCM for the same season also shows dominant periods at the grid points closest to VL2 and Gale Crater similar to those observed. In the model, the disturbances responsible for these oscillations are eastward traveling baroclinic eddies whose amplitudes are greatest at northern mid latitudes at this season, but whose meridional extent does indeed extend into the low latitudes of the southern hemisphere. REMS appears to be seeing the signature of these eddies, not only for this season but for the early fall and late winter seasons as well. While orbital images of the so called "flushing storms", which more closely correspond to the shorter period waves, show dust-lifting frontal systems that cross the equator, REMS data - even though acquired at a longitude of comparatively weak storm activity - provide the first in-situ evidence that northern hemisphere transient eddies can be detected at the surface in low latitudes of the southern hemisphere.

Transient immune impairment after a simulated long-haul flight.

PubMed

Wilder-Smith, Annelies; Mustafa, Fatima B; Peng, Chung Mien; Earnest, Arul; Koh, David; Lin, Gen; Hossain, Iqbal; MacAry, Paul A

2012-04-01

Almost 2 billion people travel aboard commercial airlines every year, with about 20% developing symptoms of the common cold within 1 wk after air travel. We hypothesize that hypobaric hypoxic conditions associated with air travel may contribute to immune impairment. We studied the effects of hypobaric hypoxic conditions during a simulated flight at 8000 ft (2438 m) cruising altitude on immune and stress markers in 52 healthy volunteers (mean age 31) before and on days 1, 4, and 7 after the flight. We did a cohort study using a generalized estimating equation to examine the differences in the repeated measures. Our findings show that the hypobaric hypoxic conditions of a 10-h overnight simulation flight are not associated with severe immune impairment or abnormal IgA or cortisol levels, but with transient impairment in some parameters: we observed a transient decrease in lymphocyte proliferative responses combined with an upregulation in CD69 and CD14 cells and a decrease in HLA-DR in the immediate days following the simulated flight that normalized by day 7 in most instances. These transient immune changes may contribute to an increased susceptibility to respiratory infections commonly seen after long-haul flights.

Flt1/VEGFR1 heterozygosity causes transient embryonic edema.

PubMed

Otowa, Yasunori; Moriwaki, Kazumasa; Sano, Keigo; Shirakabe, Masanori; Yonemura, Shigenobu; Shibuya, Masabumi; Rossant, Janet; Suda, Toshio; Kakeji, Yoshihiro; Hirashima, Masanori

2016-06-02

Vascular endothelial growth factor-A is a major player in vascular development and a potent vascular permeability factor under physiological and pathological conditions by binding to a decoy receptor Flt1 and its primary receptor Flk1. In this study, we show that Flt1 heterozygous (Flt1(+/-)) mouse embryos grow up to adult without life-threatening abnormalities but exhibit a transient embryonic edema around the nuchal and back regions, which is reminiscent of increased nuchal translucency in human fetuses. Vascular permeability is enhanced and an intricate infolding of the plasma membrane and huge vesicle-like structures are seen in Flt1(+/-) capillary endothelial cells. Flk1 tyrosine phosphorylation is elevated in Flt1(+/-) embryos, but Flk1 heterozygosity does not suppress embryonic edema caused by Flt1 heterozygosity. When Flt1 mutants are crossed with Aspp1(-/-) mice which exhibit a transient embryonic edema with delayed formation and dysfunction of lymphatic vessels, only 5.7% of Flt1(+/-); Aspp1(-/-) mice survive, compared to expected ratio (25%). Our results demonstrate that Flt1 heterozygosity causes a transient embryonic edema and can be a risk factor for embryonic lethality in combination with other mutations causing non-lethal vascular phenotype.

Reactor transient control in support of PFR/TREAT TUCOP experiments

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

Burrows, D.R.; Larsen, G.R.; Harrison, L.J.

1984-01-01

Unique energy deposition and experiment control requirements posed bythe PFR/TREAT series of transient undercooling/overpower (TUCOP) experiments resulted in equally unique TREAT reactor operations. New reactor control computer algorithms were written and used with the TREAT reactor control computer system to perform such functions as early power burst generation (based on test train flow conditions), burst generation produced by a step insertion of reactivity following a controlled power ramp, and shutdown (SCRAM) initiators based on both test train conditions and energy deposition. Specialized hardware was constructed to simulate test train inputs to the control computer system so that computer algorithms couldmore » be tested in real time without irradiating the experiment.« less

GABAergic inhibition through synergistic astrocytic neuronal interaction transiently decreases vasopressin neuronal activity during hypoosmotic challenge.

PubMed

Wang, Yu-Feng; Sun, Min-Yu; Hou, Qiuling; Hamilton, Kathryn A

2013-04-01

The neuropeptide vasopressin is crucial to mammalian osmotic regulation. Local hypoosmotic challenge transiently decreases and then increases vasopressin secretion. To investigate mechanisms underlying this transient response, we examined the effects of hypoosmotic challenge on the electrical activity of rat hypothalamic supraoptic nucleus (SON) vasopressin neurons using patch-clamp recordings. We found that 5 min exposure of hypothalamic slices to hypoosmotic solution transiently increased inhibitory postsynaptic current (IPSC) frequency and reduced the firing rate of vasopressin neurons. Recovery occurred by 10 min of exposure, even though the osmolality remained low. The γ-aminobutyric acid (GABA)A receptor blocker, gabazine, blocked the IPSCs and the hypoosmotic suppression of firing. The gliotoxin l-aminoadipic acid blocked the increase in IPSC frequency at 5 min and the recovery of firing at 10 min, indicating astrocytic involvement in hypoosmotic modulation of vasopressin neuronal activity. Moreover, β-alanine, an osmolyte of astrocytes and GABA transporter (GAT) inhibitor, blocked the increase in IPSC frequency at 5 min of hypoosmotic challenge. Confocal microscopy of immunostained SON sections revealed that astrocytes and magnocellular neurons both showed positive staining of vesicular GATs (VGAT). Hypoosmotic stimulation in vivo reduced the number of VGAT-expressing neurons, and increased co-localisation and molecular association of VGAT with glial fibrillary acidic protein that increased significantly by 10 min. By 30 min, neuronal VGAT labelling was partially restored, and astrocytic VGAT was relocated to the ventral portion while it decreased in the somatic zone of the SON. Thus, synergistic astrocytic and neuronal GABAergic inhibition could ensure that vasopressin neuron firing is only transiently suppressed under hypoosmotic conditions. © 2013 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Transient acidosis while retrieving a fear-related memory enhances its lability

PubMed Central

Du, Jianyang; Price, Margaret P; Taugher, Rebecca J; Grigsby, Daniel; Ash, Jamison J; Stark, Austin C; Hossain Saad, Md Zubayer; Singh, Kritika; Mandal, Juthika; Wemmie, John A; Welsh, Michael J

2017-01-01

Attenuating the strength of fearful memories could benefit people disabled by memories of past trauma. Pavlovian conditioning experiments indicate that a retrieval cue can return a conditioned aversive memory to a labile state. However, means to enhance retrieval and render a memory more labile are unknown. We hypothesized that augmenting synaptic signaling during retrieval would increase memory lability. To enhance synaptic transmission, mice inhaled CO2 to induce an acidosis and activate acid sensing ion channels. Transient acidification increased the retrieval-induced lability of an aversive memory. The labile memory could then be weakened by an extinction protocol or strengthened by reconditioning. Coupling CO2 inhalation to retrieval increased activation of amygdala neurons bearing the memory trace and increased the synaptic exchange from Ca2+-impermeable to Ca2+-permeable AMPA receptors. The results suggest that transient acidosis during retrieval renders the memory of an aversive event more labile and suggest a strategy to modify debilitating memories. DOI: http://dx.doi.org/10.7554/eLife.22564.001 PMID:28650315

Developmental Subchronic Exposure to Diphenylarsinic Acid Induced Increased Exploratory Behavior, Impaired Learning Behavior, and Decreased Cerebellar Glutathione Concentration in Rats

PubMed Central

Negishi, Takayuki; Matsunaga, Yuki

2013-01-01

In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0–6 weeks of age] and/or late period [7–12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA. PMID:24008832

Developmental subchronic exposure to diphenylarsinic acid induced increased exploratory behavior, impaired learning behavior, and decreased cerebellar glutathione concentration in rats.

PubMed

Negishi, Takayuki; Matsunaga, Yuki; Kobayashi, Yayoi; Hirano, Seishiro; Tashiro, Tomoko

2013-12-01

In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0-6 weeks of age] and/or late period [7-12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA.

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

Space Use and Habitat Selection by Resident and Transient Coyotes (Canis latrans)

PubMed Central

Hinton, Joseph W.; van Manen, Frank T.; Chamberlain, Michael J.

2015-01-01

Little information exists on coyote (Canis latrans) space use and habitat selection in the southeastern United States and most studies conducted in the Southeast have been carried out within small study areas (e.g., ≤1,000 km2). Therefore, studying the placement, size, and habitat composition of coyote home ranges over broad geographic areas could provide relevant insights regarding how coyote populations adjust to regionally varying ecological conditions. Despite an increasing number of studies of coyote ecology, few studies have assessed the role of transiency as a life-history strategy among coyotes. During 2009–2011, we used GPS radio-telemetry to study coyote space use and habitat selection on the Albemarle Peninsula of northeastern North Carolina. We quantified space use and 2nd- and 3rd-order habitat selection for resident and transient coyotes to describe space use patterns in a predominantly agricultural landscape. The upper limit of coyote home-range size was approximately 47 km2 and coyotes exhibiting shifting patterns of space use of areas >65 km2 were transients. Transients exhibited localized space use patterns for short durations prior to establishing home ranges, which we defined as “biding” areas. Resident and transient coyotes demonstrated similar habitat selection, notably selection of agricultural over forested habitats. However, transients exhibited stronger selection for roads than resident coyotes. Although transient coyotes are less likely to contribute reproductively to their population, transiency may be an important life history trait that facilitates metapopulation dynamics through dispersal and the eventual replacement of breeding residents lost to mortality. PMID:26148130

Space use and habitat selection by resident and transient coyotes (Canis latrans)

USGS Publications Warehouse

Hinton, Joseph W; van Manen, Frank T.; Chamberlain, Michael J

2015-01-01

Little information exists on coyote (Canis latrans) space use and habitat selection in the southeastern United States and most studies conducted in the Southeast have been carried out within small study areas (e.g., ≤1,000 km2). Therefore, studying the placement, size, and habitat composition of coyote home ranges over broad geographic areas could provide relevant insights regarding how coyote populations adjust to regionally varying ecological conditions. Despite an increasing number of studies of coyote ecology, few studies have assessed the role of transiency as a life-history strategy among coyotes. During 2009–2011, we used GPS radio-telemetry to study coyote space use and habitat selection on the Albemarle Peninsula of northeastern North Carolina. We quantified space use and 2nd- and 3rd-order habitat selection for resident and transient coyotes to describe space use patterns in a predominantly agricultural landscape. The upper limit of coyote home-range size was approximately 47 km2 and coyotes exhibiting shifting patterns of space use of areas >65 km2 were transients. Transients exhibited localized space use patterns for short durations prior to establishing home ranges, which we defined as “biding” areas. Resident and transient coyotes demonstrated similar habitat selection, notably selection of agricultural over forested habitats. However, transients exhibited stronger selection for roads than resident coyotes. Although transient coyotes are less likely to contribute reproductively to their population, transiency may be an important life history trait that facilitates metapopulation dynamics through dispersal and the eventual replacement of breeding residents lost to mortality.

Transient familial hyperbilirubinemia

MedlinePlus

... Babies with this disorder are born with severe jaundice . Causes Transient familial hyperbilirubinemia is an inherited disorder. ... death. Symptoms The newborn may have: Yellow skin (jaundice) Yellow eyes (icterus) Lethargy If untreated, seizures and ...

Transient Global Amnesia

MedlinePlus

... global amnesia is a sudden, temporary episode of memory loss that can't be attributed to a ... know well. But that doesn't make your memory loss less disturbing. Fortunately, transient global amnesia is ...

Transient studies of capillary-induced flow

NASA Technical Reports Server (NTRS)

Reagan, M. K.; Bowman, W. J.

1993-01-01

This paper presents the numerical and experimental results of a study performed on the transient rise of fluid in a capillary tube. The capillary tube problem provides an excellent mechanism from which to launch an investigation into the transient flow of a fluid in a porous wick structure where capillary forces must balance both adverse gravitational effects and frictional losses. For the study, a capillary tube, initially charged with a small volume of water, was lowered into a pool of water. The behavior of the column of fluid during the transient that followed as more water entered the tube from the pool was both numerically and experimentally studied.

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.

Transient rheology of crystallizing andesitic magmas

NASA Astrophysics Data System (ADS)

de Biasi, L. J.; Chevrel, M. O.; Hanson, J. B.; Cimarelli, C.; Lavallée, Y.; Dingwell, D. B.

2012-04-01

The viscosity of magma strongly influences its rheological behaviour, which is a key determinant of magma transport processes and volcanic eruptions. Understanding the factors controlling the viscosity of magma is important to our assessment of hazards posed by active volcanoes. In nature, magmas span a very wide range in viscosity (10-1 to 1014 Pa s), depending on chemical composition (including volatile content), temperature, and importantly, crystal fraction, which further induces a complex strain rate dependence (i.e. non-Newtonian rheology). Here, we present results of transient viscosities of a crystallizing andesitic melt (57 wt.% SiO2) from Tungurahua volcano (Ecuador). We followed the experimental method developed by Vona et al. (2011) for the concentric cylinder apparatus, but optimized its implementation by leaving the spindle in situ before quenching the experimental products, to preserve the complete developed texture of the sample. The viscosity is investigated under super-liquidus (1400 ° C) and sub-liquidus temperatures (1162 and 1167 ° C). For each temperature increment, thermal equilibrium is achieved over a period of days while the spindle constantly stirs the magma. Simultaneous monitoring of the torque is used to calculate the apparent viscosity of the transient suspension. To get a better understanding of the nucleation and crystal growth processes that are involved at sub-liquidus conditions, further time-step experiments were carried out, where the samples were quenched at various equilibration stages. The mineralogical assemblage, as well as the crystal fraction, distribution and preferential alignment were then quantitatively analyzed. At temperatures below the liquidus, the suspension shows a progressive, but irregular increase of the relative shear viscosity. First, the viscosity slightly increases, possibly due to the crystallization of small, equant oxides and the formation of plagioclase nuclei. After some time (1.5-2.5 days

Improving the management and referral of patients with transient ischaemic attacks: a change strategy for a health community

PubMed Central

Wright, J; Harrison, S; McGeorge, M; Patterson, C; Russell, I; Russell, D; Small, N; Taylor, M; Walsh, M; Warren, E; Young, J

2006-01-01

Problem Rapid referral and management of patients with transient ischaemic attacks is a key component in the national strategy for stroke prevention. However, patients with transient ischaemic attacks are poorly identified and undertreated. Design and setting Before and after evaluation of quality improvement programme with controlled comparison in three primary care trusts reflecting diverse populations and organisational structures in an urban district in the North of England. Key measures for improvement The proportion of patients receiving antiplatelet drugs and safe driving advice on referral to a speciality clinic, and the numbers of referrals, adjusted for age, to the specialist clinic before and after the improvement programme. Strategies for change Interviews with patient and professionals to identify gaps and barriers to good practice; development of evidence based guidelines for the management of patients with transient ischaemic attacks; interactive multidisciplinary workshops for each primary care trust with feedback of individual audit results of referral practice; outreach visits to teams who were unable to attend the workshops; referral templates and desktop summaries to provide reminders of the guidelines to clinicians; incorporation of standards into professional contracts. Effects of change A significant improvement occurred in identification and referral of patients with transient ischaemic attacks to specialist clinics, with a 41% increase in referrals from trained practices compared with control practices. There were also significant improvements in the early treatment and safety advice provided to patients before referral. Lessons learnt A strategic approach to effective quality improvement across a diverse health community is feasible and achievable. Careful planning with patient and professional involvement to develop a tailored and multifaceted quality improvement programme to implement evidence based practice can work in very different

Robust regression and posterior predictive simulation increase power to detect early bursts of trait evolution.

PubMed

Slater, Graham J; Pennell, Matthew W

2014-05-01

A central prediction of much theory on adaptive radiations is that traits should evolve rapidly during the early stages of a clade's history and subsequently slowdown in rate as niches become saturated--a so-called "Early Burst." Although a common pattern in the fossil record, evidence for early bursts of trait evolution in phylogenetic comparative data has been equivocal at best. We show here that this may not necessarily be due to the absence of this pattern in nature. Rather, commonly used methods to infer its presence perform poorly when when the strength of the burst--the rate at which phenotypic evolution declines--is small, and when some morphological convergence is present within the clade. We present two modifications to existing comparative methods that allow greater power to detect early bursts in simulated datasets. First, we develop posterior predictive simulation approaches and show that they outperform maximum likelihood approaches at identifying early bursts at moderate strength. Second, we use a robust regression procedure that allows for the identification and down-weighting of convergent taxa, leading to moderate increases in method performance. We demonstrate the utility and power of these approach by investigating the evolution of body size in cetaceans. Model fitting using maximum likelihood is equivocal with regards the mode of cetacean body size evolution. However, posterior predictive simulation combined with a robust node height test return low support for Brownian motion or rate shift models, but not the early burst model. While the jury is still out on whether early bursts are actually common in nature, our approach will hopefully facilitate more robust testing of this hypothesis. We advocate the adoption of similar posterior predictive approaches to improve the fit and to assess the adequacy of macroevolutionary models in general.

Victims of Chinese famine in early life have increased risk of metabolic syndrome in adulthood.

PubMed

Yu, Caizheng; Wang, Jing; Wang, Fei; Han, Xu; Hu, Hua; Yuan, Jing; Miao, Xiaoping; Yao, Ping; Wei, Sheng; Wang, Youjie; Liang, Yuan; Zhang, Xiaomin; Guo, Huan; Pan, An; Zheng, Dan; Tang, Yuhan; Yang, Handong; Wu, Tangchun; He, Meian

2018-02-05

To investigate the association of exposure to the Chinese famine during early life with metabolic syndrome risk in adults. There were 7,915 participants from Dongfeng-Tongji cohort were included in the present study. Participants were classified as non-exposed group, fetal exposed group, early childhood-, mid childhood-, and late childhood-exposed groups, respectively. Metabolic syndrome was defined according to International Diabetes Foundation criteria (2005). Logistic regression model was used to explore the association between famine exposure in early life and metabolic syndrome risk in adults. The metabolic syndrome prevalence in non-, fetal-, early childhood-, mid childhood-, and late childhood- exposed groups were 25.2%, 26.9%, 30.3%, 32.7%, and 32.7%, respectively. Compared with non-exposed group, participants exposed to famine in the fetal (0.96, 95% CI: 0.77-1.20), early childhood (1.24, 95% CI: 1.01-1.52), mid childhood (1.39, 95% CI: 1.13-1.72), and late childhood (1.33, 95% CI: 1.08-1.63) had higher metabolic syndrome prevalence risk in adults after adjustment for potential confounders (P for trend < 0.0001). In gender-specific analyses, women exposed to famine in early childhood (1.26, 95% CI: 1.02-1.56), mid childhood (1.43, 95% CI: 1.14-1.78), and late childhood (1.47, 95% CI: 1.18-1.84) had higher metabolic syndrome prevalence risk than non-exposed women (P for trend < 0.0001). There was a famine-gender interaction on metabolic syndrome prevalence risk (P for interaction = 0.0001). Results in the present study indicated that exposure to famine in early life increases the risk of metabolic syndrome in adulthood, particularly in women. Copyright © 2018 Elsevier Inc. All rights reserved.

Can state early intervention programs meet the increased demand of children suspected of having autism spectrum disorders?

PubMed

Wise, Marissa D; Little, Alison A; Holliman, Jaime Bruce; Wise, Paul H; Wang, C Jason

2010-01-01

To determine whether Early Intervention programs have the capacity to accommodate the expected increase in referrals following the American Academy of Pediatrics' 2007 recommendation for universal screening of 18- and 24-month-old children for Autism Spectrum Disorders (ASD). We conducted a telephone survey of all state and territory early. Intervention coordinators about the demand for ASD evaluations, services, and program capacity. We used multivariate models to examine state-level factors associated with the capacity to serve children with ASD. Fifty-two of the 57 coordinators (91%) responded to the survey. Most states reported an increase in demand for ASD-related evaluations (65%) and services (58%) since 2007. In addition, 46% reported that their current capacity poses a challenge to meeting the 45-day time limit for creating the Individualized Family Service Plan. Many states reported that they have shortages of ASD-related personnel, including behavioral therapists (89%), speech-language pathologists (82%), and occupational therapists (79%). Among states that reported the number of service hours (n = 34) 44% indicated that children with ASD receive 5 or fewer weekly service hours. Multivariate models showed that states with a higher percentage of African-American and Latino children were more likely to have provider shortages whereas states with higher population densities were more likely to offer a greater number of service hours. Many Early Intervention programs may not have the capability to address the expected increase in demand for ASD services. Early Intervention programs will likely need enhanced resources to provide all children with suspected ASD with appropriate evaluations and services.

Effect of transmitter turn-off time on transient soundings

USGS Publications Warehouse

Fitterman, D.V.; Anderson, W.L.

1987-01-01

A general procedure for computing the effect of non-zero turn-off time on the transient electromagnetic response is presented which can be applied to forward and inverse calculation methods for any transmitter-receiver configuration. We consider in detail the case of a large transmitter loop which has a receiver coil located at the center of the loop (central induction or in-loop array). For a linear turn-off ramp of width t0, the voltage response is shown to be the voltage due to an ideal step turn-off averaged over windows of width t0. Thus the effect is similar to that obtained by using averaging windows in the receiver. In general when time zero is taken to be the end of the ramp, the apparent resistivity increases for a homogeneous half-space over a limited time range. For time zero taken to be the start of the ramp the apparent resistivity is affected in the opposite direction. The effect of the ramp increases with increasing t0 and first-layer resistivity, is largest during the intermediate stage, and decreases with increasing time. It is shown that for a ramp turn-off, there is no effect in the early and late stages. For two-layered models with a resistive first layer (??1>??2), the apparent resistivity is increased in the intermediate stage. When the first layer is more conductive than the second layer (??1increases as time increases. Examples are presented which illustrate the strong influence of the geoelectrical section on the turn-off effect. Neglecting the turn-off ramp will affect data interpretation as shown by field examples; the influence is the greatest on near-surface layer parameters. ?? 1987.

Constraining the role of early land plants in Palaeozoic weathering and global cooling.

PubMed

Quirk, Joe; Leake, Jonathan R; Johnson, David A; Taylor, Lyla L; Saccone, Loredana; Beerling, David J

2015-08-22

How the colonization of terrestrial environments by early land plants over 400 Ma influenced rock weathering, the biogeochemical cycling of carbon and phosphorus, and climate in the Palaeozoic is uncertain. Here we show experimentally that mineral weathering by liverworts—an extant lineage of early land plants—partnering arbuscular mycorrhizal (AM) fungi, like those in 410 Ma-old early land plant fossils, amplified calcium weathering from basalt grains threefold to sevenfold, relative to plant-free controls. Phosphate weathering by mycorrhizal liverworts was amplified 9-13-fold over plant-free controls, compared with fivefold to sevenfold amplification by liverworts lacking fungal symbionts. Etching and trenching of phyllosilicate minerals increased with AM fungal network size and atmospheric CO2 concentration. Integration of grain-scale weathering rates over the depths of liverwort rhizoids and mycelia (0.1 m), or tree roots and mycelia (0.75 m), indicate early land plants with shallow anchorage systems were probably at least 10-fold less effective at enhancing the total weathering flux than later-evolving trees. This work challenges the suggestion that early land plants significantly enhanced total weathering and land-to-ocean fluxes of calcium and phosphorus, which have been proposed as a trigger for transient dramatic atmospheric CO2 sequestration and glaciations in the Ordovician. © 2015 The Authors.

Temperature shock, injury and transient sensitivity to nisin in Gram negatives.

PubMed

Boziaris, I S; Adams, M R

2001-10-01

The effect of thermal stresses on survival, injury and nisin sensitivity was investigated in Salmonella Enteritidis PT4, PT7 and Pseudomonas aeruginosa. Heating at 55 degrees C, rapid chilling to 0.5 degrees C or freezing at -20 degrees C produced transient sensitivity to nisin. Cells were only sensitive if nisin was present during stress. Resistance recovered rapidly afterwards, though some cells displayed residual injury. Injury was assessed by SDS sensitivity, hydrophobicity changes, lipopolysaccharide release and NPN uptake. LPS release and hydrophobicity were not always associated with transient nisin sensitivity. Uptake of NPN correlated better but persisted longer after treatment. Thermal shocks produce transient injury to the outer membrane, allowing nisin access. After treatment, the permeability barrier is rapidly restored by a process apparently involving reorganization rather than biosynthetic repair. Inclusion of nisin during food treatments that impose sub-lethal stress on Gram negatives could increase process lethality, enhancing microbiological safety and stability.

Transient loading of CD34+ hematopoietic progenitor cells with polystyrene nanoparticles.

PubMed

Deville, Sarah; Hadiwikarta, Wahyu Wijaya; Smisdom, Nick; Wathiong, Bart; Ameloot, Marcel; Nelissen, Inge; Hooyberghs, Jef

2017-01-01

CD34 + hematopoietic progenitor cells (HPCs) offer great opportunities to develop new treatments for numerous malignant and non-malignant diseases. Nanoparticle (NP)-based strategies can further enhance this potential, and therefore a thorough understanding of the loading behavior of HPCs towards NPs is essential for a successful application. The present study focusses on the interaction kinetics of 40 nm sized carboxylated polystyrene (PS) NPs with HPCs. Interestingly, a transient association of the NPs with HPCs is observed, reaching a maximum within 1 hour and declining afterwards. This behavior is not seen in dendritic cells (CD34-DCs) differentiated from HPCs, which display a monotonic increase in NP load. We demonstrate that this transient interaction requires an energy-dependent cellular process, suggesting active loading and release of NPs by HPCs. This novel observation offers a unique approach to transiently equip HPCs. A simple theoretical approach modeling the kinetics of NP loading and release is presented, contributing to a framework of describing this phenomenon.

Rapidly evolving and luminous transients from Pan-STARRS1

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

Drout, M. R.; Chornock, R.; Soderberg, A. M.

2014-10-10

In the past decade, several rapidly evolving transients have been discovered whose timescales and luminosities are not easily explained by traditional supernovae (SNe) models. The sample size of these objects has remained small due, at least in part, to the challenges of detecting short timescale transients with traditional survey cadences. Here we present the results from a search within the Pan-STARRS1 Medium Deep Survey (PS1-MDS) for rapidly evolving and luminous transients. We identify 10 new transients with a time above half-maximum (t {sub 1/2}) of less than 12 days and –16.5 > M > –20 mag. This increases the numbermore » of known events in this region of SN phase space by roughly a factor of three. The median redshift of the PS1-MDS sample is z = 0.275 and they all exploded in star-forming galaxies. In general, the transients possess faster rise than decline timescale and blue colors at maximum light (g {sub P1} – r {sub P1} ≲ –0.2). Best-fit blackbodies reveal photospheric temperatures/radii that expand/cool with time and explosion spectra taken near maximum light are dominated by a blue continuum, consistent with a hot, optically thick, ejecta. We find it difficult to reconcile the short timescale, high peak luminosity (L > 10{sup 43} erg s{sup –1}), and lack of UV line blanketing observed in many of these transients with an explosion powered mainly by the radioactive decay of {sup 56}Ni. Rather, we find that many are consistent with either (1) cooling envelope emission from the explosion of a star with a low-mass extended envelope that ejected very little (<0.03 M {sub ☉}) radioactive material, or (2) a shock breakout within a dense, optically thick, wind surrounding the progenitor star. After calculating the detection efficiency for objects with rapid timescales in the PS1-MDS we find a volumetric rate of 4800-8000 events yr{sup –1} Gpc{sup –3} (4%-7% of the core-collapse SN rate at z = 0.2).« less

Current thinking: return to play and transient quadriplegia.

PubMed

Cantu, Robert V; Cantu, Robert C

2005-02-01

Athletes that participate in contact and collision sports assume risk of serious injury each time they take the field. For those athletes that have sustained an episode of transient quadriplegia, the decision of whether to return to competition can be a difficult one. Some athletes, realizing how close they may have come to permanent injury, may decide that further participation is not in their best interest. Others may be somewhat undecided, and some may want to return at all costs. As the treating physician, the goal is to identify those athletes who after a single episode of transient quadriplegia are at increased risk for further injury and consequently should discontinue participation in contact sports. Factors that may contribute to that determination include mechanism of injury, prior history of neurologic symptoms or injury, and anatomic features that may predispose to further injury such as disc herniation, fracture, or cervical stenosis.

Pulsed electromagnetic fields promote the proliferation and differentiation of osteoblasts by reinforcing intracellular calcium transients.

PubMed

Tong, Jie; Sun, Lijun; Zhu, Bin; Fan, Yun; Ma, Xingfeng; Yu, Liyin; Zhang, Jianbao

2017-10-01

Pulsed electromagnetic fields (PEMF) can be used to treat bone-related diseases, but the underlying mechanism remains unclear, especially the process by which PEMFs initiate biological effects. In this study, we demonstrated the effects of PEMF on proliferation and differentiation of osteoblasts using the model of calcium transients induced by high extracellular calcium. Our results showed that PEMF can increase both the percentage of responding cells and amplitude of intracellular calcium transients induced by high extracellular calcium stimulation. Compared with corresponding extracellular calcium levels, PEMF stimulation increased proliferation and differentiation of osteoblasts and related gene expressions, such as insulin-like growth factor 1 (IGF-1), alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), which can be completely abolished by BAPTA-AM. Moreover, PEMF did not affect proliferation and differentiation of osteoblasts if no intracellular calcium transient was present in osteoblasts during PEMF exposure. Our results revealed that PEMF affects osteoblast proliferation and differentiation through enhanced intracellular calcium transients, which provided a cue to treat bone-related diseases with PEMF. Bioelectromagnetics. 38:541-549, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples

NASA Astrophysics Data System (ADS)

Suslova, A.; El-Atwani, O.; Sagapuram, D.; Harilal, S. S.; Hassanein, A.

2014-11-01

Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten.

Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples

PubMed Central

Suslova, A.; El-Atwani, O.; Sagapuram, D.; Harilal, S. S.; Hassanein, A.

2014-01-01

Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten. PMID:25366885

Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples.

PubMed

Suslova, A; El-Atwani, O; Sagapuram, D; Harilal, S S; Hassanein, A

2014-11-04

Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten.

Stability Test for Transient-Temperature Calculations

NASA Technical Reports Server (NTRS)

Campbell, W.

1984-01-01

Graphical test helps assure numerical stability of calculations of transient temperature or diffusion in composite medium. Rectangular grid forms basis of two-dimensional finite-difference model for heat conduction or other diffusion like phenomena. Model enables calculation of transient heat transfer among up to four different materials that meet at grid point.

Search for Transient Gravitational Waves in Coincidence with Short-Duration Radio Transients During 2007-2013

NASA Technical Reports Server (NTRS)

Abbott, B. P.; Hughey, Brennan; Zanolin, Michele; Szczepanczyk, Marek; Gill, Kiranjyot; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.;

Early behavioral inhibition and increased error monitoring predict later social phobia symptoms in childhood

PubMed Central

Lahat, Ayelet; Lamm, Connie; Chronis-Tuscano, Andrea; Pine, Daniel S.; Henderson, Heather A.; Fox, Nathan A.

2014-01-01

Objective Behavioral inhibition (BI) is an early childhood temperament characterized by fearful responses to novelty and avoidance of social interactions. During adolescence, a subset of children with stable childhood BI develop social anxiety disorder and concurrently exhibit increased error monitoring. The current study examines whether increased error monitoring in seven-year-old behaviorally inhibited children prospectively predicts risk for symptoms of social phobia at age 9. Method Two hundred and ninety one children were characterized on BI at 24 and 36 months of age. Children were seen again at 7 years of age, where they performed a Flanker task, and event-related-potential (ERP) indices of response monitoring were generated. At age 9, self- and maternal-report of social phobia symptoms were obtained. Results Children high in BI, compared to those low in BI, displayed increased error monitoring at age 7, as indexed by larger (i.e., more negative) error-related negativity (ERN) amplitudes. Additionally, early BI was related to later childhood social phobia symptoms at age 9 among children with a large difference in amplitude between ERN and correct-response negativity (CRN) at age 7. Conclusions Heightened error monitoring predicts risk for later social phobia symptoms in children with high BI. Research assessing response monitoring in children with BI may refine our understanding of the mechanisms underlying risk for later anxiety disorders and inform prevention efforts. PMID:24655654

A comparison of the effects of commercially available hawthorn preparations on calcium transients of isolated cardiomyocytes.

PubMed

Rodriguez, Michelle E; Poindexter, Brian J; Bick, Roger J; Dasgupta, Amitava

2008-12-01

We studied the potential cardiac effects of two alcohol extracts of commercially available hawthorn using rat cardiomyocytes and measuring calcium transients by real-time fluorescence spectrophotometry. One preparation was a blend of hawthorn flowers, leaves, and berries (extract #1), and the other (extract #2) was from a "berries-only" preparation. Fluorescent images and calcium transients were acquired concurrently. Addition of extract #1 resulted in the initiation of robust calcium transients and eventual calcium overload, while addition of extract #2 caused increased calcium sparking, initiation of calcium transients, and an increased beating rate but no calcium overload. To identify the mechanisms of increased calcium influx, adult rat cardiomyocytes were challenged with 10 microM ouabain, a Na(+),K(+)-ATPase inhibitor, and the calcium channel blocker nifedipine. The findings revealed that equal volumes of the two readily available hawthorn preparations demonstrated markedly different effects on isolated adult rat cardiomyocytes, suggesting important implications for patients who are using these preparations to supplement or even replace their prescribed cardiac medications as to which preparation(s) to use, and potential dire consequences, particularly in cardiac patients. Our study indicates that the mechanism of cardiac activity of hawthorn is via the Na(+),K(+)-ATPase and intracellular calcium concentrations are influenced.

Early Dexamethasone Treatment Induces Placental Apoptosis in Sheep

PubMed Central

Meng, Wenbin; Shang, Hongkai; Li, Shaofu; Sloboda, Deborah M.; Ehrlich, Loreen; Lange, Karolin; Xu, Huaisheng; Henrich, Wolfgang; Dudenhausen, Joachim W.; Plagemann, Andreas; Newnham, John P.; Challis, John R. G.

2015-01-01

Glucocorticoid treatment given in late pregnancy in sheep resulted in altered placental development and function. An imbalance of placental survival and apoptotic factors resulting in an increased rate of apoptosis may be involved. We have now investigated the effects of dexamethasone (DEX) in early pregnancy on binucleate cells (BNCs), placental apoptosis, and fetal sex as a determinant of these responses. Pregnant ewes carrying singleton fetuses (n = 105) were randomized to control (n = 56, 2 mL saline/ewe) or DEX treatment (n = 49, intramuscular injections of 0.14 mg/kg ewe weight per 12 hours over 48 hours) at 40 to 41 days of gestation (dG). Placentomes were collected at 50, 100, 125, and 140 dG. At 100 dG, DEX in females reduced BNC numbers, placental antiapoptotic (proliferating cell nuclear antigen), and increased proapoptotic factors (Bax, p53), associated with a temporarily decrease in fetal growth. At 125 dG, BNC numbers and apoptotic markers were restored to normal. In males, ovine placental lactogen-protein levels after DEX were increased at 50 dG, but at 100 and 140 dG significantly decreased compared to controls. In contrast to females, these changes were independent of altered BNC numbers or apoptotic markers. Early DEX was associated with sex-specific, transient alterations in BNC numbers, which may contribute to changes in placental and fetal development. Furthermore, in females, altered placental apoptosis markers may be involved. PMID:25063551

Ca2+ signalling and early embryonic patterning during zebrafish development.

PubMed

Webb, Sarah E; Miller, Andrew L

2007-09-01

1. It has been proposed that Ca2+ signalling, in the form of pulses, waves and steady gradients, may play a crucial role in key pattern-forming events during early vertebrate development. 2. With reference to the embryo of the zebrafish (Danio rerio), herein we review the Ca2+ transients reported from the cleavage to segmentation periods. This time-window includes most of the major pattern-forming events of early development, which transform a single-cell zygote into a complex multicellular embryo with established primary germ layers and body axes. 3. Data are presented to support our proposal that intracellular Ca2+ waves are an essential feature of embryonic cytokinesis and that propagating intercellular Ca2+ waves (both long and short range) may play a crucial role in: (i) the establishment of the embryonic periderm and the coordination of cell movements during epiboly, convergence and extension; (ii) the establishment of the basic embryonic axes and germ layers; and (iii) definition of the morphological boundaries of specific tissue domains and embryonic structures, including future organ anlagen. 4. The potential downstream targets of these Ca2+ transients are also discussed, as well as how they may integrate with other pattern-forming signalling pathways known to modulate early developmental events.

Early donor management increases the retrieval rate of hearts for transplantation in marginal donors.

PubMed

Abuanzeh, Razi; Hashmi, Faisal; Dimarakis, Ioannis; Khasati, Noman; Machaal, Ali; Yonan, Nizar; Venkateswaran, Rajamiyer V

2015-01-01

Organ donations continue to fall, failing to meet the clinical requirements for heart transplantation. Furthermore, the pathophysiology of brain stem death including hormonal and inflammatory changes may lead to significant donor heart injury. Early donor management may potentially alleviate these changes and therefore increase the number of available hearts for transplantation. We aimed to investigate whether early management of borderline donors can increase the heart retrieval rate. Between September 2011 and February 2013, we performed early donor management of 26 potential heart donors in the intensive care units of the respective donor hospitals. At the time of referral donors were considered as borderline based on high-dose inotrope requirements, history of hypertension and cardiopulmonary resuscitation. Our management protocol included insertion of a pulmonary artery catheter and performance of cardiac output studies, weaning noradrenaline and commencing arginine vasopressin, and administration of tri-iodothyronine, methylprednisolone and insulin. Our primary end-point was donor heart acceptance, depending collectively on the results of cardiac output studies, cardiac contractility and coronary artery patency at the time of retrieval operation. We retrieved 14 (56%) borderline hearts after donor management (Group A) with a 30-day survival rate of 86%. Twelve (44%) organs were declined due to poor heart function (n=8; 66.7%; P<0.001) and/or palpable coronary artery disease (n=4; 33.3%; P=0.018) (Group B). The mean age of Groups A and B was 42.77 and 47.78 years, respectively (P=0.19). Most of the female donors, i.e. 10 (83%), were declined, and only 4 (27%) were accepted (P=0.005). Majority of patients in both groups (Group A: 71.4%; n=10; and Group B: 66.7%; n=8) were on high-dose noradrenaline (>0.08 μg kg(-1) min(-2)) at the time of donor offer. Group A had a mean cardiac output of 6.29 and 3.09 l/min for Group B (P=0.01). A positive smoking history was

Association Between Increased Vascular Density and Loss of Protective RAS in Early-Stage NPDR

NASA Technical Reports Server (NTRS)

Radhakrishnan, Krishnan; Raghunandan, Sneha; Vyas, Ruchi J.; Vu, Amanda C.; Bryant, Douglas; Yaqian, Duan; Knecht, Brenda E.; Grant, Maria B.; Chalam, K . V.; Parsons-Wingerter, Patricia

2016-01-01

Our hypothesis predicts that retinal blood vessels increase in density during early-stage progression to moderate nonproliferative diabetic retinopathy (NPDR). The prevailing paradigm of NPDR progression is that vessels drop out prior to abnormal, vision-impairing regrowth at late-stage proliferative diabetic retinopathy (DR). However, surprising results for our previous preliminary study 1 with NASA's VESsel GENeration Analysis (VESGEN) software showed that vessels proliferated considerably during moderate NPDR compared to drop out at both mild and severe NPDR. Validation of our hypothesis will support development of successful early-stage regenerative therapies such as vascular repair by circulating angiogenic cells (CACs). The renin-angiotensin system (RAS)is implicated in the pathogenesis of DR and in the function of CACs, a critical bone marrow-derived population that is instrumental in vascular repair.

Colonoscopic screening shows increased early incidence and progression of adenomas in cystic fibrosis

PubMed Central

Niccum, David E.; Billings, Joanne L.; Dunitz, Jordan M.; Khoruts, Alexander

2018-01-01

Background Colorectal cancer is an emerging problem in cystic fibrosis (CF). The goal of this study was to evaluate adenoma detection by systematic colonoscopic screening and surveillance. Methods We analyzed prospectively collected results of colonoscopies initiated at age 40 years from 88 CF patients at a single Cystic Fibrosis Center. We also reviewed results of diagnostic colonoscopies from 27 patients aged 30–39 years performed during the same time period at the Center. Results The incidence of polyp detection increased markedly after age 40 in CF patients. Greater than 50% were found to have adenomatous polyps; approximately 25% had advanced adenomas as defined by size and/or histopathology; 3% were found to have colon cancer. Multivariate analysis demonstrated specific risk factors for adenoma formation and progression. Conclusions Early screening and more frequent surveillance should be considered in patients with CF due to early incidence and progression of adenomas in this patient population. PMID:26851188

Transient Seepage for Levee Engineering Analyses

NASA Astrophysics Data System (ADS)

Tracy, F. T.

2017-12-01

Historically, steady-state seepage analyses have been a key tool for designing levees by practicing engineers. However, with the advances in computer modeling, transient seepage analysis has become a potentially viable tool. A complication is that the levees usually have partially saturated flow, and this is significantly more complicated in transient flow. This poster illustrates four elements of our research in partially saturated flow relating to the use of transient seepage for levee design: (1) a comparison of results from SEEP2D, SEEP/W, and SLIDE for a generic levee cross section common to the southeastern United States; (2) the results of a sensitivity study of varying saturated hydraulic conductivity, the volumetric water content function (as represented by van Genuchten), and volumetric compressibility; (3) a comparison of when soils do and do not exhibit hysteresis, and (4) a description of proper and improper use of transient seepage in levee design. The variables considered for the sensitivity and hysteresis studies are pore pressure beneath the confining layer at the toe, the flow rate through the levee system, and a levee saturation coefficient varying between 0 and 1. Getting results for SEEP2D, SEEP/W, and SLIDE to match proved more difficult than expected. After some effort, the results matched reasonably well. Differences in results were caused by various factors, including bugs, different finite element meshes, different numerical formulations of the system of nonlinear equations to be solved, and differences in convergence criteria. Varying volumetric compressibility affected the above test variables the most. The levee saturation coefficient was most affected by the use of hysteresis. The improper use of pore pressures from a transient finite element seepage solution imported into a slope stability computation was found to be the most grievous mistake in using transient seepage in the design of levees.

Increased plasma leptin attenuates adaptive metabolism in early lactating dairy cows.

PubMed

Ehrhardt, Richard A; Foskolos, Andreas; Giesy, Sarah L; Wesolowski, Stephanie R; Krumm, Christopher S; Butler, W Ronald; Quirk, Susan M; Waldron, Matthew R; Boisclair, Yves R

2016-05-01

Mammals meet the increased nutritional demands of lactation through a combination of increased feed intake and a collection of adaptations known as adaptive metabolism (e.g., glucose sparing via insulin resistance, mobilization of endogenous reserves, and increased metabolic efficiency via reduced thyroid hormones). In the modern dairy cow, adaptive metabolism predominates over increased feed intake at the onset of lactation and develops concurrently with a reduction in plasma leptin. To address the role of leptin in the adaptive metabolism of early lactation, we asked which adaptations could be countered by a constant 96-h intravenous infusion of human leptin (hLeptin) starting on day 8 of lactation. Compared to saline infusion (Control), hLeptin did not alter energy intake or milk energy output but caused a modest increase in body weight loss. hLeptin reduced plasma glucose by 9% and hepatic glycogen content by 73%, and these effects were associated with a 17% increase in glucose disposal during an insulin tolerance test. hLeptin attenuated the accumulation of triglyceride in the liver by 28% in the absence of effects on plasma levels of the anti-lipolytic hormone insulin or plasma levels of free fatty acids, a marker of lipid mobilization from adipose tissue. Finally, hLeptin increased the plasma concentrations of T4 and T3 by nearly 50% without affecting other neurally regulated hormones (i.e., cortisol and luteinizing hormone (LH)). Overall these data implicate the periparturient reduction in plasma leptin as one of the signals promoting conservation of glucose and energy at the onset of lactation in the energy-deficient dairy cow. © 2016 Society for Endocrinology.

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.

Timing of transients: quantifying reaching times and transient behavior in complex systems

NASA Astrophysics Data System (ADS)

Kittel, Tim; Heitzig, Jobst; Webster, Kevin; Kurths, Jürgen

2017-08-01

In dynamical systems, one may ask how long it takes for a trajectory to reach the attractor, i.e. how long it spends in the transient phase. Although for a single trajectory the mathematically precise answer may be infinity, it still makes sense to compare different trajectories and quantify which of them approaches the attractor earlier. In this article, we categorize several problems of quantifying such transient times. To treat them, we propose two metrics, area under distance curve and regularized reaching time, that capture two complementary aspects of transient dynamics. The first, area under distance curve, is the distance of the trajectory to the attractor integrated over time. It measures which trajectories are ‘reluctant’, i.e. stay distant from the attractor for long, or ‘eager’ to approach it right away. Regularized reaching time, on the other hand, quantifies the additional time (positive or negative) that a trajectory starting at a chosen initial condition needs to approach the attractor as compared to some reference trajectory. A positive or negative value means that it approaches the attractor by this much ‘earlier’ or ‘later’ than the reference, respectively. We demonstrated their substantial potential for application with multiple paradigmatic examples uncovering new features.

Critical role of canonical transient receptor potential channel 7 in initiation of seizures.

PubMed

Phelan, Kevin D; Shwe, U Thaung; Abramowitz, Joel; Birnbaumer, Lutz; Zheng, Fang

2014-08-05

Status epilepticus (SE) is a life-threatening disease that has been recognized since antiquity but still causes over 50,000 deaths annually in the United States. The prevailing view on the pathophysiology of SE is that it is sustained by a loss of normal inhibitory mechanisms of neuronal activity. However, the early process leading to the initiation of SE is not well understood. Here, we show that, as seen in electroencephalograms, SE induced by the muscarinic agonist pilocarpine in mice is preceded by a specific increase in the gamma wave, and genetic ablation of canonical transient receptor potential channel (TRPC) 7 significantly reduces this pilocarpine-induced increase of gamma wave activity, preventing the occurrence of SE. At the cellular level, TRPC7 plays a critical role in the generation of spontaneous epileptiform burst firing in cornu ammonis (CA) 3 pyramidal neurons in brain slices. At the synaptic level, TRPC7 plays a significant role in the long-term potentiation at the CA3 recurrent collateral synapses and Schaffer collateral-CA1 synapses, but not at the mossy fiber-CA3 synapses. Taken together, our data suggest that epileptiform burst firing generated in the CA3 region by activity-dependent enhancement of recurrent collateral synapses may be an early event in the initiation process of SE and that TRPC7 plays a critical role in this cellular event. Our findings reveal that TRPC7 is intimately involved in the initiation of seizures both in vitro and in vivo. To our knowledge, this contribution to initiation of seizures is the first identified functional role for the TRPC7 ion channel.

Mucosal IgA increase in rats by continuous CLA feeding during suckling and early infancy.

PubMed

Pérez-Cano, Francisco J; Ramírez-Santana, Carolina; Molero-Luís, Marta; Castell, Margarida; Rivero, Montserrat; Castellote, Cristina; Franch, Angels

2009-03-01

The aim of this work was to establish the effect of the cis9,trans11 conjugated linoleic acid (CLA) isomer on mucosal immunity during early life in rats, a period when mucosal immunoglobulin production is poorly developed, as is also the case in humans. CLA supplementation was performed during three life periods: gestation, suckling, and early infancy. The immune status of supplemented animals was evaluated at two time points: at the end of the suckling period (21-day-old rats) and 1 week after weaning (28-day-old rats). Secretory IgA was quantified in intestinal washes from 28-day-old rats by ELISA technique. IgA, TGFbeta, and PPARgamma mRNA expression was measured in small intestine and colon by real time PCR, using Taqman specific probes and primers. IgA mucosal production was enhanced in animals supplemented with CLA during suckling and early infancy: in 28-day-old rats, IgA mRNA expression was increased in small intestine and colon by approximately 6- and 4-fold, respectively, and intestinal IgA protein by approximately 2-fold. TGFbeta gene expression was independent of age and type of tissue considered, and was not modified by dietary CLA. Gene expression of PPARgamma, a possible mediator of CLA's effects was also upregulated in animals receiving CLA during early life. In conclusion, dietary supplementation with CLA during suckling and extended to early infancy enhances development of the intestinal immune response in rats.

A transient laboratory method for determining the hydraulic properties of 'tight' rocks-I. Theory

USGS Publications Warehouse

Hsieh, P.A.; Tracy, J.V.; Neuzil, C.E.; Bredehoeft, J.D.; Silliman, Stephen E.

1981-01-01

Transient pulse testing has been employed increasingly in the laboratory to measure the hydraulic properties of rock samples with low permeability. Several investigators have proposed a mathematical model in terms of an initial-boundary value problem to describe fluid flow in a transient pulse test. However, the solution of this problem has not been available. In analyzing data from the transient pulse test, previous investigators have either employed analytical solutions that are derived with the use of additional, restrictive assumptions, or have resorted to numerical methods. In Part I of this paper, a general, analytical solution for the transient pulse test is presented. This solution is graphically illustrated by plots of dimensionless variables for several cases of interest. The solution is shown to contain, as limiting cases, the more restrictive analytical solutions that the previous investigators have derived. A method of computing both the permeability and specific storage of the test sample from experimental data will be presented in Part II. ?? 1981.

Efficacy and Tolerability of Indiplon in Transient Insomnia

PubMed Central

Rosenberg, Russell; Roth, Thomas; Scharf, Martin B.; Lankford, D. Alan; Farber, Robert

2007-01-01

Objectives: The efficacy of indiplon was evaluated by polysomnography (PSG) in an experimental model of transient insomnia consisting of the first night effect combined with a 2-hour phase advance. Methods: Healthy volunteers age 21–64 years (N=593; 62% female; mean (± SEM) years, 32±0.39) were randomized to double-blind treatment with a single nighttime dose of indiplon (10 mg or 20 mg) or placebo. PSG assessments included latency to persistent sleep (LPS, primary endpoint) and total sleep time (TST); self-report assessments included sleep quality (SQ); next day residual effects were evaluated by the Digit Symbol Substitution Test (DSST), Symbol Copying Test (SCT), and a Visual Analog Scale of sleepiness (VAS). Results: LPS mean (± SEM) values were significantly reduced on indiplon 10 mg (21.2±1.5 minutes) and indiplon 20 mg (16.8±1.1 minutes) compared to placebo (33.1±2.5minutes; p <0.0001 for both comparisons to placebo). TST mean (± SEM) values were significantly increased on indiplon 10 mg (414.5±3.9 minutes) and indiplon 20 mg (423.5±3.1 minutes) compared to placebo (402.9±3.9 minutes; p <0.005 for the 10 mg dose; p <0.0001 for the 20 mg dose). SQ was also significantly improved on both doses. There were no differences between indiplon and placebo on next day DSST, SCT, or VAS. Conclusions: Indiplon was effective in inducing sleep, increasing sleep duration, and improving overall sleep quality without next day residual effects in healthy volunteers in a model of transient insomnia. Citation: Rosenberg R; Roth T; Scharf MB et al. Efficacy and tolerability of indiplon in transient insomnia. J Clin Sleep Med 2007;3(4):374-379. PMID:17694726

Four RNA families with functional transient structures.

PubMed

Zhu, Jing Yun A; Meyer, Irmtraud M

2015-01-01

Protein-coding and non-coding RNA transcripts perform a wide variety of cellular functions in diverse organisms. Several of their functional roles are expressed and modulated via RNA structure. A given transcript, however, can have more than a single functional RNA structure throughout its life, a fact which has been previously overlooked. Transient RNA structures, for example, are only present during specific time intervals and cellular conditions. We here introduce four RNA families with transient RNA structures that play distinct and diverse functional roles. Moreover, we show that these transient RNA structures are structurally well-defined and evolutionarily conserved. Since Rfam annotates one structure for each family, there is either no annotation for these transient structures or no such family. Thus, our alignments either significantly update and extend the existing Rfam families or introduce a new RNA family to Rfam. For each of the four RNA families, we compile a multiple-sequence alignment based on experimentally verified transient and dominant (dominant in terms of either the thermodynamic stability and/or attention received so far) RNA secondary structures using a combination of automated search via covariance model and manual curation. The first alignment is the Trp operon leader which regulates the operon transcription in response to tryptophan abundance through alternative structures. The second alignment is the HDV ribozyme which we extend to the 5' flanking sequence. This flanking sequence is involved in the regulation of the transcript's self-cleavage activity. The third alignment is the 5' UTR of the maturation protein from Levivirus which contains a transient structure that temporarily postpones the formation of the final inhibitory structure to allow translation of maturation protein. The fourth and last alignment is the SAM riboswitch which regulates the downstream gene expression by assuming alternative structures upon binding of SAM. All

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

Rapid ionic modifications during the aequorin-detected calcium transient in a skinned canine cardiac Purkinje cell

PubMed Central

1985-01-01

A microprocessor-controlled system of microinjections and microaspirations has been developed to change, within approximately 1 ms, the [free Ca2+] at the outer surface of the sarcoplasmic reticulum (SR) wrapped around individual myofibrils (0.3-0.4 micron radius) of a skinned canine cardiac Purkinje cell (2.5-4.5 micron overall radius) at different phases of a Ca2+ transient. Simultaneously monitoring tension and aequorin bioluminescence provided two methods for estimating the peak myoplasmic [free Ca2+] reached during the spontaneous cyclic Ca2+ release from the SR obtained in the continuous presence of a bulk solution [free Ca2+] sufficiently high to overload the SR. These methods gave results in excellent agreement for the spontaneous Ca2+ release under a variety of conditions of pH and [free Mg2+], and of enhancement of Ca2+ release by calmodulin. Disagreement was observed, however, when the Ca2+ transient was modified during its ascending phase. The experiments also permitted quantification of the aequorin binding within the myofibrils and determination of its operational apparent affinity constant for Ca2+ at various [free Mg2+] levels. An increase of [free Ca2+] at the outer surface of the SR during the ascending phase of the Ca2+ transient induced further release of Ca2+. In contrast, an increase of [free Ca2+] during the descending phase of the Ca2+ transient did not cause further Ca2+ release. Varying [free H+], [free Mg2+], or the [Na+]/[K+] ratio had no significant effect on the Ca2+ transient during which the modification was applied, but it altered the subsequent Ca2+ transient. Therefore, Ca2+ appears to be the major, if not the only, ion controlling Ca2+ release from the SR rapidly enough to alter a Ca2+ transient during its course. PMID:3981128

SPIRITS: Uncovering Unusual Infrared Transients with Spitzer

NASA Astrophysics Data System (ADS)

Kasliwal, Mansi M.; Bally, John; Masci, Frank; Cody, Ann Marie; Bond, Howard E.; Jencson, Jacob E.; Tinyanont, Samaporn; Cao, Yi; Contreras, Carlos; Dykhoff, Devin A.; Amodeo, Samuel; Armus, Lee; Boyer, Martha; Cantiello, Matteo; Carlon, Robert L.; Cass, Alexander C.; Cook, David; Corgan, David T.; Faella, Joseph; Fox, Ori D.; Green, Wayne; Gehrz, R. D.; Helou, George; Hsiao, Eric; Johansson, Joel; Khan, Rubab M.; Lau, Ryan M.; Langer, Norbert; Levesque, Emily; Milne, Peter; Mohamed, Shazrene; Morrell, Nidia; Monson, Andy; Moore, Anna; Ofek, Eran O.; O' Sullivan, Donal; Parthasarathy, Mudumba; Perez, Andres; Perley, Daniel A.; Phillips, Mark; Prince, Thomas A.; Shenoy, Dinesh; Smith, Nathan; Surace, Jason; Van Dyk, Schuyler D.; Whitelock, Patricia A.; Williams, Robert

2017-04-01

We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS—SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer/IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between -11 and -14 (Vega-mag) and [3.6]-[4.5] colors between 0.3 mag and 1.6 mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1 mag yr-1 to >7 mag yr-1. SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.

Impacts of northern Tibetan Plateau on East Asian summer rainfall via modulating midlatitude transient eddies

NASA Astrophysics Data System (ADS)

Deng, Jiechun; Xu, Haiming; Shi, Ning; Zhang, Leying; Ma, Jing

2017-08-01

Roles of the Tibetan Plateau (TP) in forming and changing the seasonal Asian climate system have been widely explored. However, little is known about modulation effects of the TP on extratropical transient eddies (TEs) and subsequent synoptic responses of the East Asian rainfall. In this study, the Community Atmosphere Model version 5.1 coupled with a slab ocean model is employed to highlight the important role of the TP in regulating the upper-tropospheric transient wave train. Comparison between sensitivity experiments with and without the TP shows that the northern TP excites a strong anomalous anticyclone, which shifts the upper-level East Asian westerly jet northward and helps transfer barotropic and baroclinic energy from the mean flow to the synoptic TE flow. The transient wave train is primarily shifted northward by northern TP and is forced to propagate southeastward along the eastern flank of the TP until reaching eastern China. Before the strengthening of monsoonal southerlies, the TP-modulated transient wave train cools the troposphere, which decreases the static stability over northern China. Meanwhile, the associated anomalous warm advection induces ascending motion, leading to excessive rainfall by releasing unstable energy as the southerly strengthens. Due to the southeastward propagation of the wave train, anomalous heavy rainfall subsequently appears over eastern China from north to south, which increases day-to-day rainfall variation in this region. Additionally, occurrence of this upper-tropospheric transient wave train associated with low-level southerly peak is substantially increased by northern TP.

Early Attachment-Figure Separation and Increased Risk for Later Depression: Potential Mediation by Proinflammatory Processes

PubMed Central

Hennessy, Michael B.; Deak, Terrence; Schiml-Webb, Patricia A.

2009-01-01

Early maternal separation and other disruptions of attachment relations are known to increase risk for the later onset of depressive illness in vulnerable individuals. It is suggested here that sensitization involving proinflammatory processes may contribute to this effect. This argument is based on: (1) current notions of the role of proinflammatory cytokines in depressive illness; (2) evidence that proinflammatory cytokines mediate depressive-like behavior during separation in a rodent model of infant attachment; and (3) comparisons of the effects of early proinflammatory activation versus maternal separation on later proinflammatory activity and biobehavioral processes related to depression. The possible interaction of proinflammatory processes and corticotropin-releasing factor in the sensitization process is discussed. PMID:20359585

Enhanced tocopherol levels during early germination events in Chamaerops humilis var. humilis seeds.

PubMed

Siles, Laura; Alegre, Leonor; Tijero, Verónica; Munné-Bosch, Sergi

2015-10-01

Most angiosperms accumulate vitamin E in the form of tocopherols in seeds, exerting a protective antioxidant role. However, several palm trees principally accumulate tocotrienols, rather than tocopherols, in seeds, as it occurs in other monocots. To unravel the protective role of either tocopherols or tocotrienols against lipid peroxidation during seed germination in Chamaerops humilis var. humilis; seed viability, natural and induced germination capacity, seed water content, malondialdehyde levels (as an indicator of the extent of lipid peroxidation) and vitamin E levels (including both tocopherols and tocotrienols) were examined at various germination phases in a simulated, natural seed bank. At the very early stages of germination (operculum removal), malondialdehyde levels increased 2.8-fold, to decrease later up to 74%, thus indicating a transient lipid peroxidation at early stages of germination. Tocopherol levels were absent in quiescent seeds and did not increase during operculum removal, but increased later presumably dampening malondialdehyde accumulation. Thereafter, tocopherols continued increasing, while lipid peroxidation levels decreased. By contrast, tocotrienols levels remained constant or even decreased as germination progressed, showing no correlation with lipid peroxidation levels. We hypothesize that despite their high tocotrienol content, seeds synthesize tocopherols during germination to protect lipids from peroxidation events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Correlation of transient adenosine release and oxygen changes in the caudate-putamen

PubMed Central

Wang, Ying; Venton, B. Jill

2016-01-01

Adenosine is an endogenous nucleoside that modulates important physiological processes, such as vasodilation, in the central nervous system. A rapid, 2–4 seconds, mode of adenosine signaling has been recently discovered, but the relationship between this type of adenosine and blood flow change has not been characterized. In this study, adenosine and oxygen changes were simultaneously measured using fast-scan cyclic voltammetry. Oxygen changes occur when there is an increase in local cerebral blood flow and thus are a measure of vasodilation. About 34% of adenosine transients in the rat caudate-putamen are correlated with a subsequent transient change in oxygen. The amount of oxygen was correlated with the concentration of adenosine release and larger adenosine transients (over 0.4 μM) always had subsequent oxygen changes. The average duration of adenosine and oxygen transients were 3.2 seconds and 3.5 seconds, respectively. On average, the adenosine release starts and peaks 0.2 seconds prior to the oxygen. The A2a antagonist, SCH442416, decreased the number of both adenosine and oxygen transient events by about 32%. However, the A1 antagonist, DPCPX, did not significantly affect simultaneous adenosine and oxygen release. The nitric oxide (NO) synthase inhibitor L-NAME also did not affect the concentration or number of adenosine and oxygen release events. These results demonstrate that both adenosine and oxygen release are modulated via A2a receptors. The correlation of transient concentrations, time delay between adenosine and oxygen peaks, and effect of A2a receptors suggests adenosine modulates blood flow on a rapid, sub-second time scale. PMID:27314215

Conducted Transients on Spacecraft Primary Power Lines

NASA Technical Reports Server (NTRS)

Mc Closkey, John; Dimov, Jen

2017-01-01

One of the sources of potential interference on spacecraft primary power lines is that of conducted transients resulting from equipment being switched on and off of the bus. Susceptibility to such transients is addressed by some version of the CS06 requirement of MIL-STD-461462. This presentation provides a summary of the history of the CS06 requirement and test method, a basis for understanding of the sources of these transients, analysis techniques for determining their worst-case characteristics, and guidelines for minimizing their magnitudes and applying the requirement appropriately.

MOLECULAR AND MORPHOLOGICAL CHANGES IN ZEBRAFISH FOLLOWING TRANSIENT ETHANOL EXPOSURE DURING DEFINED DEVELOPMENTAL STAGES

PubMed Central

Zhang, Chengjin; Frazier, Jared M.; Chen, Hao; Liu, Yao; Lee, Ju-Ahng; Cole, Gregory J.

2014-01-01

Alcohol is a teratogen that has diverse effects on brain and craniofacial development, leading to a constellation of developmental disorders referred to as fetal alcohol spectrum disorder (FASD). The molecular basis of ethanol insult remains poorly understood, as does the relationship between molecular and behavioral changes as a consequence of prenatal ethanol exposure. Zebrafish embryos were exposed to a range of ethanol concentrations (0.5–5.0%) during defined developmental stages, and examined for morphological phenotypes characteristic of FASD. Embryos were also analyzed by in situ hybridization for changes in expression of defined cell markers for neural cell types that are sonic hedgehog-dependent. We show that transient binge-like ethanol exposures during defined developmental stages, such as early gastrulation and early neurulation, result in a range of phenotypes and changes in expression of Shh-dependent genes. The severity of fetal alcohol syndrome (FAS) morphological phenotypes, such as microphthalmia, depends on the embryonic stage and concentration of alcohol exposure, as does diminution of retinal Pax6a or forebrain and hindbrain GAD1 gene expression. We also show that changes in eye and brain morphology correlate with changes in Pax6a and GAD1 gene expression. Our results therefore show that transient binge-like ethanol exposures in zebrafish embryos produce the stereotypical morphological phenotypes of FAS, with the severity of phenotypes depending on the developmental stage and alcohol concentration of exposure. PMID:24929233

Transient Ischemic Attack

MedlinePlus

A transient ischemic attack (TIA) is a stroke that lasts only a few minutes. It happens when the blood supply to part of the brain is briefly blocked. Symptoms of a TIA are like other stroke symptoms, but do not ...

Acute lipophilicity-dependent effect of intravascular simvastatin in the early phase of focal cerebral ischemia.

PubMed

Beretta, S; Pastori, C; Sala, G; Piazza, F; Ferrarese, C; Cattalini, A; de Curtis, M; Librizzi, L

2011-05-01

The acute effects of simvastatin lactone (lipophilic) and simvastatin acid (hydrophilic) on transient focal ischemia were assessed using the isolated guinea pig brain maintained in vitro by arterial perfusion. This new model of cerebral ischemia allows the assessment of the very early phase of the ischemic process, with the functional preservation of the vascular and neuronal compartments and the blood-brain barrier (bbb). The middle cerebral artery was transiently tied for 30 min followed by reperfusion for 60 min. Statins (nanomolar doses) were administered by intravascular continuous infusion starting 60 min before ischemia induction. Brain cortical activity and arterial vascular tone were continuously recorded. At the end of the experiment immunoreactivity for microtubule-associated protein 2 (MAP-2), expression of survival kinases (ERK and Akt) and total anti-oxidant capacity were assayed. Brains treated with simvastatin lactone showed i) reduced amplitude and delayed onset of ischemic depressions, ii) preservation of MAP-2 immunoreactivity, iii) activation of ERK signaling in the ischemic hemisphere and iv) increase in whole-brain anti-oxidant capacity. Treatment with the bbb-impermeable simvastatin acid was ineffective on the above-mentioned parameters. Vascular resistance recordings and Akt signaling were unchanged by any statin treatment. Our findings suggest that intravascular-delivered simvastatin exerts an acute lipophilicity-dependent protective effect in the early phase of cerebral ischemia. Copyright © 2011 Elsevier Ltd. All rights reserved.

EBR-II high-ramp transients under computer control

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

Forrester, R.J.; Larson, H.A.; Christensen, L.J.

1983-01-01

During reactor run 122, EBR-II was subjected to 13 computer-controlled overpower transients at ramps of 4 MWt/s to qualify the facility and fuel for transient testing of LMFBR oxide fuels as part of the EBR-II operational-reliability-testing (ORT) program. A computer-controlled automatic control-rod drive system (ACRDS), designed by EBR-II personnel, permitted automatic control on demand power during the transients.

Kinetically Controlled Lifetimes in Redox-Responsive Transient Supramolecular Hydrogels.

PubMed

Wojciechowski, Jonathan P; Martin, Adam D; Thordarson, Pall

2018-02-28

It remains challenging to program soft materials to show dynamic, tunable time-dependent properties. In this work, we report a strategy to design transient supramolecular hydrogels based on kinetic control of competing reactions. Specifically, the pH-triggered self-assembly of a redox-active supramolecular gelator, N,N'-dibenzoyl-l-cystine (DBC) in the presence of a reducing agent, which acts to disassemble the system. The lifetimes of the transient hydrogels can be tuned simply by pH or reducing agent concentration. We find through kinetic analysis that gel formation hinders the ability of the reducing agent and enables longer transient hydrogel lifetimes than would be predicted. The transient hydrogels undergo clean cycles, with no kinetically trapped aggregates observed. As a result, multiple transient hydrogel cycles are demonstrated and can be predicted. This work contributes to our understanding of designing transient assemblies with tunable temporal control.

Physical Origin of Transient Negative Capacitance in a Ferroelectric Capacitor

NASA Astrophysics Data System (ADS)

Chang, Sou-Chi; Avci, Uygar E.; Nikonov, Dmitri E.; Manipatruni, Sasikanth; Young, Ian A.

2018-01-01

Transient negative differential capacitance, the dynamic reversal of transient capacitance in an electrical circuit, is of highly technological and scientific interest since it probes the foundation of ferroelectricity. We study a resistor-ferroelectric capacitor (R -FEC) network through a series of coupled equations based on Kirchhoff's law, electrostatics, and Landau theory. We show that transient negative capacitance (NC) in a R -FEC circuit originates from the mismatch in switching rate between the free charge on the metal plate and the bound charge in a ferroelectric (FE) capacitor during the polarization switching. This transient free charge-polarization mismatch is driven by the negative curvature of the FE free-energy landscape, and it is also analytically shown that a free-energy profile with a negative curvature is the only physical system that can describe transient NC in a R -FEC circuit. Furthermore, transient NC induced by the free charge-polarization mismatch is justified by its dependence on both external resistance and the intrinsic FE viscosity coefficient. The depolarization effect on FE capacitors emphasizes the importance of negative curvature to transient NC and also implies that transient and steady-state NC cannot be observed in a FE capacitor simultaneously. Finally, using the transient NC measurements, a procedure to experimentally determine the viscosity coefficient is presented to provide more insight into the relation between transient NC and the FE free-energy profile.

Constitutional SAMD9L mutations cause familial myelodysplastic syndrome and transient monosomy 7

PubMed Central

Pastor, Victor B.; Sahoo, Sushree S.; Boklan, Jessica; Schwabe, Georg C.; Saribeyoglu, Ebru; Strahm, Brigitte; Lebrecht, Dirk; Voss, Matthias; Bryceson, Yenan T.; Erlacher, Miriam; Ehninger, Gerhard; Niewisch, Marena; Schlegelberger, Brigitte; Baumann, Irith; Achermann, John C.; Shimamura, Akiko; Hochrein, Jochen; Tedgård, Ulf; Nilsson, Lars; Hasle, Henrik; Boerries, Melanie; Busch, Hauke; Niemeyer, Charlotte M.; Wlodarski, Marcin W.

2018-01-01

Familial myelodysplastic syndromes arise from haploinsufficiency of genes involved in hematopoiesis and are primarily associated with early-onset disease. Here we describe a familial syndrome in seven patients from four unrelated pedigrees presenting with myelodysplastic syndrome and loss of chromosome 7/7q. Their median age at diagnosis was 2.1 years (range, 1–42). All patients presented with thrombocytopenia with or without additional cytopenias and a hypocellular marrow without an increase of blasts. Genomic studies identified constitutional mutations (p.H880Q, p.R986H, p.R986C and p.V1512M) in the SAMD9L gene on 7q21, with decreased allele frequency in hematopoiesis. The non-random loss of mutated SAMD9L alleles was attained via monosomy 7, deletion 7q, UPD7q, or acquired truncating SAMD9L variants p.R1188X and p.S1317RfsX21. Incomplete penetrance was noted in 30% (3/10) of mutation carriers. Long-term observation revealed divergent outcomes with either progression to leukemia and/or accumulation of driver mutations (n=2), persistent monosomy 7 (n=4), and transient monosomy 7 followed by spontaneous recovery with SAMD9L-wildtype UPD7q (n=2). Dysmorphic features or neurological symptoms were absent in our patients, pointing to the notion that myelodysplasia with monosomy 7 can be a sole manifestation of SAMD9L disease. Collectively, our results define a new subtype of familial myelodysplastic syndrome and provide an explanation for the phenomenon of transient monosomy 7. Registered at: www.clinicaltrials.gov; #NCT00047268. PMID:29217778

Constitutional SAMD9L mutations cause familial myelodysplastic syndrome and transient monosomy 7.

PubMed

Pastor, Victor B; Sahoo, Sushree S; Boklan, Jessica; Schwabe, Georg C; Saribeyoglu, Ebru; Strahm, Brigitte; Lebrecht, Dirk; Voss, Matthias; Bryceson, Yenan T; Erlacher, Miriam; Ehninger, Gerhard; Niewisch, Marena; Schlegelberger, Brigitte; Baumann, Irith; Achermann, John C; Shimamura, Akiko; Hochrein, Jochen; Tedgård, Ulf; Nilsson, Lars; Hasle, Henrik; Boerries, Melanie; Busch, Hauke; Niemeyer, Charlotte M; Wlodarski, Marcin W

2018-03-01

Familial myelodysplastic syndromes arise from haploinsufficiency of genes involved in hematopoiesis and are primarily associated with early-onset disease. Here we describe a familial syndrome in seven patients from four unrelated pedigrees presenting with myelodysplastic syndrome and loss of chromosome 7/7q. Their median age at diagnosis was 2.1 years (range, 1-42). All patients presented with thrombocytopenia with or without additional cytopenias and a hypocellular marrow without an increase of blasts. Genomic studies identified constitutional mutations (p.H880Q, p.R986H, p.R986C and p.V1512M) in the SAMD9L gene on 7q21, with decreased allele frequency in hematopoiesis. The non-random loss of mutated SAMD9L alleles was attained via monosomy 7, deletion 7q, UPD7q, or acquired truncating SAMD9L variants p.R1188X and p.S1317RfsX21. Incomplete penetrance was noted in 30% (3/10) of mutation carriers. Long-term observation revealed divergent outcomes with either progression to leukemia and/or accumulation of driver mutations (n=2), persistent monosomy 7 (n=4), and transient monosomy 7 followed by spontaneous recovery with SAMD9L -wildtype UPD7q (n=2). Dysmorphic features or neurological symptoms were absent in our patients, pointing to the notion that myelodysplasia with monosomy 7 can be a sole manifestation of SAMD9L disease. Collectively, our results define a new subtype of familial myelodysplastic syndrome and provide an explanation for the phenomenon of transient monosomy 7. Registered at: www.clinicaltrials.gov; #NCT00047268 . Copyright© 2018 Ferrata Storti Foundation.

Changes in cerebral blood flow and vasoreactivity in response to acetazolamide in patients with transient global amnesia

PubMed Central

Sakashita, Y.; Kanai, M.; Sugimoto, T.; Taki, S.; Takamori, M.

1997-01-01

OBJECTIVE—Previous reports about changes in cerebral blood flow (CBF) in transient global amnesia disclosed decreased flow in some parts of the brain. However, CBF analyses in most reports were qualitative but not quantitative. The purpose of this study was to determine changes in CBF in transient global amnesia.
METHODS—The CBF was measured and the vasoreactive response to acetazolamide was evaluated in six patients with transient global amnesia using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). The CBF was measured during an attack in two patients and soon after an attack in the other four. About one month later, CBF was re-evaluated in each patient.
RESULTS—Two patients examined during an attack and one patient examined five hours after an attack had increased blood flow in the occipital cortex and cerebellum. Three patients examined at six to 10 hours after an attack had decreased blood flow in the thalamus, cerebellum, or putamen. These abnormalities of blood flow almost disappeared in all patients one month after onset. The vasodilatory response to acetazolamide, which was evaluated initially using SPECT, was poor in areas of increased blood flow. By the second evaluation of CBF with acetazolamide, the vasodilatory response had returned to normal.
CONCLUSIONS—In a patient with transient global amnesia, CBF increased in the vertebrobasilar territory during the attack and decreased afterwards. The vasodilatory response to acetazolamide may be impaired in the parts of the brain with increased blood flow. It is suggested that transient global amnesia is distinct from migraine but may share the same underlying mechanism.

 PMID:9408101

Line transients with corona

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

Saied, M.M.; Safar, Y.A.; Salama, M.H.

1987-01-01

This paper investigates the effect of corona on the electromagnetic transients along high voltage overhead lines. A method is presented to simulate the line by dividing it into a number of sections connected in cascade. For {ital n} line sections, the number of the unknown variables is 2{ital n} + 1. The method allows any waveform of the exciting voltage function, as well as any impedance loading condition. The corona is represented by voltage-dependent shunt current sources. A systematic way for writing a sufficient number of differential equations is shown. For their solution, a digital computer subroutine based on themore » Runge--Kutta--Verner method was used. An artificial frequency-dependent damping by means of linear resistors was used to suppress the Gibb's oscillations in the solution. The proposed method is applied to study the transients on a 40 km high voltage line with 30-ft flat phase spacing and a single 1.4 inch ACSR conductor per phase. The exciting voltage has a double-exponential impulse waveform. Solutions are given for three values of resistive loads Z{sub {ital c}}2Z{sub {ital c}} and Z{sub {ital c}}/2, where Z{sub {ital c}} is the line surge impedance. The results of two interesting cases of inductive and capacitive loads are also given. Physical interpretations for the different solutions are given. Also, the current-voltage duality between inductive and capacitive loads is recognized. The corona was found to attenuate and distort the travelling waves. For example, during one wave excursion, the reduction of the current wave peaks can reach values as high as 8.5%. The effect is more noticeable in the current than in the voltage waves. As expected, it increases also with the line corona losses. The effect of the increase of the line effective capacitance due to the corona discharge is also demonstrated.« less

Transient slow gamma synchrony underlies hippocampal memory replay

PubMed Central

Carr, Margaret F.; Karlsson, Mattias P.; Frank, Loren M.

2012-01-01

Summary The replay of previously stored memories during hippocampal sharp wave ripples (SWRs) is thought to support both memory retrieval and consolidation in distributed hippocampal-neocortical circuits. Replay events consist of precisely timed sequences of spikes from CA3 and CA1 neurons that are coordinated both within and across hemispheres. The mechanism of this coordination is not understood. Here we show that during SWRs in both awake and quiescent states there are transient increases in slow gamma (20-50Hz) power and synchrony across dorsal CA3 and CA1 networks of both hemispheres. These gamma oscillations entrain CA3 and CA1 spiking. Moreover, during awake SWRs, higher levels of slow gamma synchrony are predictive of higher quality replay of past experiences. Our results indicate that CA3–CA1 gamma synchronization is a central component of awake memory replay and suggest that transient gamma synchronization serves as a clocking mechanism to enable coordinated memory reactivation across the hippocampal network. PMID:22920260

Current Practice Trends for Use of Early Venous Thromboembolism Prophylaxis After Intracerebral Hemorrhage.

PubMed

Cherian, Laurel J; Smith, Eric E; Schwamm, Lee H; Fonarow, Gregg C; Schulte, Phillip J; Xian, Ying; Wu, Jingjing; Prabhakaran, Shyam K

2018-01-01

Venous thromboembolism (VTE) is common after intracerebral hemorrhage (ICH). Guidelines recommend early VTE prophylaxis. To determine characteristics associated with early chemoprophylaxis (CP) after ICH in the Get With The Guidelines-Stroke registry. In this observational cohort study, we identified patients with ICH between January 1, 2009 and September 30, 2013, who (1) were non-ambulatory and/or not comfort care measures by hospital day 2; (2) were not transferred to another acute care facility; and (3) had known VTE prophylaxis status at end of hospital day 2. Categories for VTE prophylaxis were as follows: (1) mechanical non-CP or (2) CP with or without mechanical prophylaxis. Early prophylaxis was defined as occurring by hospital day 2. Using multivariable logistic regression, we assessed patient, hospital, and geographic factors independently associated with early CP use. Among 74 283 patients with ICH from 1358 hospitals, 5929 (7.9%) received early CP, 66 444 (89.4%) received early mechanical/non-CP, and 1910 (2.6%) had no prophylaxis, mechanical or CP, within the first 2 days. There was no increase in early CP use over the study period; 60% of hospitals provided early CP to <9% of patients. In multivariable analysis, female sex, atrial fibrillation, diabetes, coronary, carotid, and peripheral artery disease, prior ischemic stroke or transient ischemic attack, hospital size >500 beds, and geographic region were independently associated with early vs no early CP use. Nationwide, the large majority of ICH patients receive early mechanical VTE prophylaxis only, without CP. Patient comorbidities and hospital characteristics such as geographic location are determinants of higher use of early CP. Copyright © 2017 by the Congress of Neurological Surgeons

Asiago spectroscopic classification of 3 transients

NASA Astrophysics Data System (ADS)

Tomasella, L.; Benetti, S.; Cappellaro, E.; Turatto, M.

2018-01-01

The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of AT 2018eq discovered by R. Belligoli (ISSP) in the direction of M31; PS18bq (AT2018bi) discovered by J. Grzegorzek and Pan-STARRS1 in UGC1791; and AT2018C (= Gaia18aak), a blue hostless transient discovered by Gaia.

Network Connectivity for Permanent, Transient, Independent, and Correlated Faults

NASA Technical Reports Server (NTRS)

White, Allan L.; Sicher, Courtney; henry, Courtney

2012-01-01

This paper develops a method for the quantitative analysis of network connectivity in the presence of both permanent and transient faults. Even though transient noise is considered a common occurrence in networks, a survey of the literature reveals an emphasis on permanent faults. Transient faults introduce a time element into the analysis of network reliability. With permanent faults it is sufficient to consider the faults that have accumulated by the end of the operating period. With transient faults the arrival and recovery time must be included. The number and location of faults in the system is a dynamic variable. Transient faults also introduce system recovery into the analysis. The goal is the quantitative assessment of network connectivity in the presence of both permanent and transient faults. The approach is to construct a global model that includes all classes of faults: permanent, transient, independent, and correlated. A theorem is derived about this model that give distributions for (1) the number of fault occurrences, (2) the type of fault occurrence, (3) the time of the fault occurrences, and (4) the location of the fault occurrence. These results are applied to compare and contrast the connectivity of different network architectures in the presence of permanent, transient, independent, and correlated faults. The examples below use a Monte Carlo simulation, but the theorem mentioned above could be used to guide fault-injections in a laboratory.

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.

Increased Aldosterone Release During Head-Up Tilt in Early Primary Hypertension.