Compact Optical Temporal Processors

Cataloged from PDF version of article.Optical signal processing can be done with time-lens devices. A temporal processor based on chirp-z transformers is suggested. This configuration is more compact than a conventional 4-f temporal processor. On the basis of implementation aspects of such a temporal processor, we did a performance analysis. This analysis leads to the conclusion that an ultrafast optical temporal processor can be implemented

Placental Pathology in Relation to Uterine Artery Doppler Findings in Pregnancies with Severe Intrauterine Growth Restriction and Abnormal Umbilical Artery Doppler Changes

OBJECTIVES: Current guidelines for diagnosis and management of early-onset intrauterine growth restriction (IUGR) rely on umbilical artery Doppler (UAD), without including uterine artery Doppler (UtAD). We hypothesized that IUGR cases with abnormal UAD but normal UtAD has a different spectrum of placental pathology compared with those with abnormal UtAD. STUDY DESIGN: Retrospective review of pregnancies with sonographic evidence of IUGR and abnormal UAD prior to delivery. Cases with ≥ 1 UtAD record(s) after 18(+0) weeks' gestation and placental pathology were included. Cases were stratified according to initial UtAD pulsatility index (PI) values (n = 196): normal (n = 19; PI < 95th centile for gestational age/no notching), intermediate (n = 69; PI ≥ 95th centile/no/unilateral notching) and abnormal (n = 108; PI ≥ 95th centile/bilateral notching). Pregnancy outcomes and placental pathology were compared between groups. RESULTS: Women in the normal group delivered later than those in the abnormal group (30.1 ± 3.5 vs. 28.0 ± 3.5 weeks; mean ± standard deviation; p = 0.03). Their placentas exhibited higher rates of chronic intervillositis (15.8 vs. 0.9%; p = 0.01), chorangiosis (15.8 vs. 0.9%; p < 0.0001), and massive perivillous fibrin deposition (21.1 vs. 7.4%; p = 0.05), but had lower rates of uteroplacental vascular insufficiency (26.3 vs. 79.6%; p < 0.0001). CONCLUSION: Approximately 10% of pregnancies with early-onset IUGR and abnormal UAD exhibited normal UtAD waveforms. They delivered later, and their placentas exhibited unusual placental pathologies

Scopolamine induces deficits in spontaneous object-location recognition and fear-learning in marmoset monkeys

The non-selective muscarinic receptor antagonist scopolamine (SCP) induces memory deficits in both animals and humans. However, few studies have assessed the effects of amnesic agents on memory functions of marmosets – a small-bodied neotropical primate that is becoming increasingly used as a translational model for several neuropathologies. Here we assessed the effects of an acute SCP administration (0.03 mg/kg, sc) on the behavior of adult marmoset monkeys in two tasks. In the spontaneous object-location (SOL) recognition task, two identical neutral stimuli were explored on the sample trial, after which preferential exploration of the displaced versus the stationary object was analyzed on the test trial. In the fear-motivated behavior (FMB) procedure, the same subjects were submitted to an initial baseline trial, followed by an exposure period to a snake model and lastly a post-exposure trial. All trials and inter-trial intervals lasted 10 min for both tests. Results showed that on the SOL test trial, the saline group explored the displaced object significantly longer than its identical stationary counterpart, whereas SCP-treated marmosets explored both objects equivalently. In the FMB test, the saline group – but not the SCP-treated animals – spent significantly less time where the stimulus had been specifically encountered and more time being vigilant of their surroundings, compared to pre-exposure levels. Drug-related effects on general activity, overall exploration (SOL task) and behavioral response to the aversive stimulus (FMB task) were not observed. SCP thus impaired the marmosets’ short-term ability to detect changes associated with the spatial location of ethologically irrelevant (SOL task) and relevant stimuli (FMB task). Similar results have been reported in other animal species. Marmosets may thus help reduce the translational gap between pre-clinical studies and memory-associated human pathologies

Arctic air pollution: Challenges and opportunities for the next decade

The Arctic is a sentinel of global change. This region is influenced by multiple physical and socio-economic drivers and feedbacks, impacting both the natural and human environment. Air pollution is one such driver that impacts Arctic climate change, ecosystems and health but significant uncertainties still surround quantification of these effects. Arctic air pollution includes harmful trace gases (e.g. tropospheric ozone) and particles (e.g. black carbon, sulphate) and toxic substances (e.g. polycyclic aromatic hydrocarbons) that can be transported to the Arctic from emission sources located far outside the region, or emitted within the Arctic from activities including shipping, power production, and other industrial activities. This paper qualitatively summarizes the complex science issues motivating the creation of a new international initiative, PACES (air Pollution in the Arctic: Climate, Environment and Societies). Approaches for coordinated, international and interdisciplinary research on this topic are described with the goal to improve predictive capability via new understanding about sources, processes, feedbacks and impacts of Arctic air pollution. Overarching research actions are outlined, in which we describe our recommendations for 1) the development of trans-disciplinary approaches combining social and economic research with investigation of the chemical and physical aspects of Arctic air pollution; 2) increasing the quality and quantity of observations in the Arctic using long-term monitoring and intensive field studies, both at the surface and throughout the troposphere; and 3) developing improved predictive capability across a range of spatial and temporal scales

Detection of pollution transport events southeast of Mexico City using ground-based visible spectroscopy measurements of nitrogen dioxide

This work presents ground based differential optical absorption spectroscopy (DOAS) measurements of nitrogen dioxide (NO&lt;sub&gt;2&lt;/sub&gt;) during the MILAGRO field campaign in March 2006 at the Tenango del Aire research site located to the southeast of Mexico City. The DOAS NO&lt;sub&gt;2&lt;/sub&gt; column density measurements are used in conjunction with ceilometer, meteorological and surface nitric oxide (NO), nitrogen oxides (NO&lt;sub&gt;x&lt;/sub&gt;) and total reactive nitrogen (NO&lt;sub&gt;y&lt;/sub&gt;) measurements to analyze pollution transport events to the southeast of Mexico City during the MILARGO field campaign. The study divides the data set into three case study pollution transport events that occurred at the Tenango del Aire research site. The unique data set is then used to provide an in depth analysis of example days of each of the pollution transport events. An in depth analysis of 13 March 2006, a Case One day, shows the transport of several air pollution plumes during the morning through the Tenango del Aire research site when southerly winds are present and demonstrates how DOAS tropospheric NO&lt;sub&gt;2&lt;/sub&gt; vertical column densities (VCD), surface NO&lt;sub&gt;2&lt;/sub&gt; mixing ratios and ceilometer data are used to determine the vertical homogeneity of the pollution layer. The analysis of 18 March 2006, a Case Two day, shows that when northerly winds are present for the entire day, the air at the Tenango del Aire research site is relatively clean and no major pollution plumes are detected. Case 3 days are characterized by relatively clean air throughout the morning with large DOAS NO&lt;sub&gt;2&lt;/sub&gt; enhancements detected in the afternoon. The analysis of 28 March 2006 show the DOAS NO&lt;sub&gt;2&lt;/sub&gt; enhancements are likely due to lightning activity and demonstrate how suitable ground-based DOAS measruements are for monitoring anthropogenic and natural pollution sources that reside above the mixing layer

Time-to-birth prediction models and the influence of expert opinions

Preterm birth is the leading cause of death among children under five years old. The pathophysiology and etiology of preterm labor are not yet fully understood. This causes a large number of unnecessary hospitalizations due to high--sensitivity clinical policies, which has a significant psychological and economic impact. In this study, we present a predictive model, based on a new dataset containing information of 1,243 admissions, that predicts whether a patient will give birth within a given time after admission. Such a model could provide support in the clinical decision-making process. Predictions for birth within 48 h or 7 days after admission yield an Area Under the Curve of the Receiver Operating Characteristic (AUC) of 0.72 for both tasks. Furthermore, we show that by incorporating predictions made by experts at admission, which introduces a potential bias, the prediction effectiveness increases to an AUC score of 0.83 and 0.81 for these respective tasks

The human leukemia virus HTLV-1 alters the structure and transcription of host chromatin in cis

Chromatin looping controls gene expression by regulating promoter-enhancer contacts, the spread of epigenetic modifications, and the segregation of the genome into transcriptionally active and inactive compartments. We studied the impact on the structure and expression of host chromatin by the human retrovirus HTLV-1. We show that HTLV-1 disrupts host chromatin structure by forming loops between the provirus and the host genome; certain loops depend on the critical chromatin architectural protein CTCF, which we recently discovered binds to the HTLV-1 provirus. We show that the provirus causes two distinct patterns of abnormal transcription of the host genome in cis: bidirectional transcription in the host genome immediately flanking the provirus, and clone-specific transcription in cis at non-contiguous loci up to >300 kb from the integration site. We conclude that HTLV-1 causes insertional mutagenesis up to the megabase range in the host genome in >104 persistently-maintained HTLV-1+ T-cell clones in vivo

Spinoza

"Spinoza", second edition. Encyclopedia entry for the Springer Encyclopedia of EM Phil and the Sciences, ed. D. Jalobeanu and C. T. Wolfe