Dampening Spontaneous Activity Improves the Light Sensitivity and Spatial Acuity of Optogenetic Retinal Prosthetic Responses

Retinitis pigmentosa is a progressive retinal dystrophy that causes irreversible visual impairment and blindness. Retinal prostheses currently represent the only clinically available vision-restoring treatment, but the quality of vision returned remains poor. Recently, it has been suggested that the pathological spontaneous hyperactivity present in dystrophic retinas may contribute to the poor quality of vision returned by retinal prosthetics by reducing the signal-to-noise ratio of prosthetic responses. Here, we investigated to what extent blocking this hyperactivity can improve optogenetic retinal prosthetic responses. We recorded activity from channelrhodopsin-expressing retinal ganglion cells in retinal wholemounts in a mouse model of retinitis pigmentosa. Sophisticated stimuli, inspired by those used in clinical visual assessment, were used to assess light sensitivity, contrast sensitivity and spatial acuity of optogenetic responses; in all cases these were improved after blocking spontaneous hyperactivity using meclofenamic acid, a gap junction blocker. Our results suggest that this approach significantly improves the quality of vision returned by retinal prosthetics, paving the way to novel clinical applications. Moreover, the improvements in sensitivity achieved by blocking spontaneous hyperactivity may extend the dynamic range of optogenetic retinal prostheses, allowing them to be used at lower light intensities such as those encountered in everyday life

Establishment of the Alfalfa Weevil Parasite \u3ci\u3eMicroctonus Aethiopoides (Hymenoptera: Braconidae)\u3c/i\u3e in Michigan

Microctonus aethiopoides, a braconid parasite of adult alfalfa weevil, Hypera postica, is now established in southeastern Minnesota. Releases were made near Caledonia in Houston County, in 1978 and 1979, and near Rosemount in Dakota County, in 1979 and 1980. M. aethiopoides was recovered in Houston County in 1979, a new state record, and since has expanded its range more than 40 km from the release site. Establishment in Dakota County was unexpected because of low host densities, but parasites were recovered there in 1983. Other workers have recovered M. aethiopoides in Olmstead County

Spread of epileptiform activity in the immature rat neocortex studied with voltage-sensitive dyes and laser scanning microscopy

1. Adult rats and rats with a postnatal age of 3-29 days (PN 3-29) were used for the preparation of in vitro slices of the frontal neocortex. Epileptiform activity was induced by bath application of the gamma-aminobutyric acid-A (GABAA) receptor antagonists bicuculline or picrotoxin. 2. The voltage-sensitive dye RH 414 and a laser scanning microscope were used for multiple-site optical recordings of membrane potential changes associated with epileptiform activity. Optical signals were compared with simultaneously measured extra-cellular field potentials. 3. Optical signals could be reliably recorded for the duration of the experiments (2-4 h). Extracellular recordings of convulsant-induced paroxysmal depolarizing shifts (PDSs) in slices stained with RH 414 were comparable with those obtained in unstained slices. Changes in dye signals in response to reductions in extracellular calcium, addition of tetrodotoxin (TTX), or application of excitatory amino acid receptor antagonists indicate that the fluorescence changes correlate well with established electrophysiological measures of epileptiform activity. 4. In slices from adult animals, dye signals were observed at all recording sites. The response with the shortest latency occurred invariably at the site of stimulation, and activity spread rapidly in both vertical and horizontal directions. Spread was significantly faster in the vertical than in the horizontal direction. 5. Epileptiform activity was absent or only weakly expressed in slices from PN 3-9 animals. Activity was detectable predominantly in upper cortical layers. 6. Dye signals were observed at all measurement points in slices from PN 10-19 animals. In this age group, peak amplitude increased with spread of activity from lower to upper cortical layers. There was no significant difference between the speed of propagation in the vertical and in the horizontal directions. Spontaneous epileptiform activity occurred at a high rate in the PN 10-19 age group, and signals associated with spontaneous epileptiform events were largest in upper layers. 7. In the PN 10-19 age group, optical signals were characterized by the repetitive occurrence of PDS discharges superimposed on a sustained response. The amplitude of the sustained response decreased with increasing distance from the site of stimulation. Analysis of the latencies revealed that the superimposed PDS-like events were generated at multiple sites within the scanning area. Amplitude and rate of rise were largest in slices from PN 10-19 animals. These values declined with ongoing development

In vivo stability of ester- and ether-linked phospholipid-containing liposomes as measured by perturbed angular correlation spectroscopy

To evaluate liposome formulations for use as intracellular sustained-release drug depots, we have compared the uptake and degradation in rat liver and spleen of liposomes of various compositions, containing as their bulk phospholipid an ether-linked phospholipid or one of several ester-linked phospholipids, by perturbed angular correlation spectroscopy. Multilamellar and small unilamellar vesicles (MLVs and SUVs), composed of egg phosphatidylcholine, sphingomyelin, distearoyl phosphatidylcholine (DSPC), dipalmitoyl phosphatidylcholine (DPPC) or its analog dihexadecylglycerophosphorylcholine (DHPC), and cholesterol plus phosphatidylserine, and containing (111)In complexed to nitrilotriacetic acid, were injected intravenously in rats. Recovery of (111)In-labeled liposomes in blood, liver, and spleen was assessed at specific time points after injection and the percentage of liposomes still intact in liver and spleen was determined by measurement of the time-integrated angular perturbation factor ([G22(∞)] of the (111)In label. We found that MLVs but not SUVs, having DHPC as their bulk phospholipid, showed an increased resistance against lysosomal degradation as compared to other phospholipid-containing liposomes. The use of diacyl phospholipids with a high gel/liquid-crystalline phase-transition temperature, such as DPPC and DSPC, also retarded degradation of MLV, but not of SUV in the dose range tested, while the rate of uptake of these liposomes by the liver was lower

An early record of Meloidogyne fallax from Ireland

Root-knot nematodes, Meloidogyne spp., cause huge economic losses worldwide. Currently, three Meloidogyne spp. are present on the quarantine A2 list of EPPO, M. chitwoodi, M. fallax and M. enterolobii. As a quarantine organism, M. fallax has been detected in England and Northern Ireland on sport turf in 2011, and in England on leek in 2013. However, its presence in Ireland has probably been overlooked since 1965, when Mr. John F. Moore and Dr. Mary T. Franklin had detected a new Meloidogyne species for that time. While the relevant data was recorded and a preliminary manuscript describing the species was prepared but never submitted for publication, and together with the original slides, pictures and drawings, it was restudied recently. We compared the population of Irish Meloidogyne sp. to other similar Meloidogyne spp. Careful observation and comparison shows that it belongs to M. fallax. The characters found to be common for Irish Meloidogyne sp. and M. fallax are female stylet length (14.6 mu m) with oval to rounded basal knobs, oval shaped perineal pattern with moderately high dorsal arch, slender stylet in males (18.5 mu m) with set off and rounded basal knobs, slightly set off male head with one post-labial annule and incomplete transverse incisures, and second-stage juveniles with large and rounded stylet basal knobs, and a gradually tapering tail (46.9 mu m) with a broadly rounded tip and a clearly delimitated smooth hyaline part sometimes marked by constrictions (12.9 mu m). The host test and gall formation also correspond to M. fallax. The identification could not be additionally supported by molecular analysis, as we were unable to extract DNA from the old permanent slides. Nevertheless, our study reveals that the Meloidogyne species detected in Ireland in 1965 belongs to M. fallax

Clear-sky biases in satellite infrared estimates of upper tropospheric humidity and its trends

We use microwave retrievals of upper tropospheric humidity (UTH) to estimate the impact of clear-sky-only sampling by infrared instruments on the distribution, variability and trends in UTH. Our method isolates the impact of the clear-sky-only sampling, without convolving errors from other sources. On daily time scales IR-sampled UTH contains large data gaps in convectively active areas, with only about 20-30 % of the tropics (30 S­ 30 N) being sampled. This results in a dry bias of about -9 %RH in the area-weighted tropical daily UTH time series. On monthly scales, maximum clear-sky bias (CSB) is up to -30 %RH over convectively active areas. The magnitude of CSB shows significant correlations with UTH itself (-0.5) and also with the variability in UTH (-0.6). We also show that IR-sampled UTH time series have higher interannual variability and smaller trends compared to microwave sampling. We argue that a significant part of the smaller trend results from the contrasting influence of diurnal drift in the satellite measurements on the wet and dry regions of the tropics

Hackerville: A laboratory environment for security literacy

Teenage internet usage is on the rise. With the increase in activity comes a need to train students to be secure online. But awareness campaigns and top ten lists aren\u27t enough. With the ever evolving attack vectors, students need to be able to adapt and recognize potentially malicious attacks. Literacy is therefore the best course of action when teaching students how to be safe and secure online. And a course will need to have a hands-on component, so that students can experience attacks in a safe and secure environment, as well as be able to recognize attacks when they happen. The objective of this paper is to create a lab framework to be used with a security literacy course. This framework will be modular, with the ability to add new modules as new attacks, and new types of websites come about. The lab will need to have the ability to evolve with the ever-changing attack landscape. In this paper, I present, in detail, how this framework works, and what components are necessary to make this framework successful

Time-Domain Measurement of Spontaneous Vibrational Decay of Magnetically Trapped NH

The v = 1 -> 0 radiative lifetime of NH (X triplet-Sigma-, v=1,N=0) is determined to be tau_rad,exp. = 37.0 +/- 0.5 stat +2.0 / -0.8 sys miliseconds, corresponding to a transition dipole moment of |mu_10| = 0.0540 + 0.0009 / -0.0018 Debye. To achieve the long observation times necessary for direct time-domain measurement, vibrationally excited NH (X triplet-Sigma-, v=1,N=0) radicals are magnetically trapped using helium buffer-gas loading. Simultaneous trapping and lifetime measurement of both the NH(v=1, N=0) and NH(v=0,N=0) populations allows for accurate extraction of tau_rad,exp. Background helium atoms are present during our measurement of tau_rad,exp., and the rate constant for helium atom induced collisional quenching of NH(v=1,N=0) was determined to be k_q < 3.9 * 10^-15 cm^3/s. This bound on k_q yields the quoted systematic uncertainty on tau_rad,exp. Using an ab initio dipole moment function and an RKR potential, we also determine a theoretical value of 36.99 ms for this lifetime, in agreement with our experimental value. Our results provide an independent determination of tau_rad,10, test molecular theory, and furthermore demonstrate the efficacy of buffer-gas loading and trapping in determining metastable radiative and collisional lifetimes.Comment: 10 pages + 3 figures (11 pages total) v2 has minor corrections and explanations accepted for publication in PR

Nonrigid reconstruction of 3D breast surfaces with a low-cost RGBD camera for surgical planning and aesthetic evaluation

Accounting for 26% of all new cancer cases worldwide, breast cancer remains the most common form of cancer in women. Although early breast cancer has a favourable long-term prognosis, roughly a third of patients suffer from a suboptimal aesthetic outcome despite breast conserving cancer treatment. Clinical-quality 3D modelling of the breast surface therefore assumes an increasingly important role in advancing treatment planning, prediction and evaluation of breast cosmesis. Yet, existing 3D torso scanners are expensive and either infrastructure-heavy or subject to motion artefacts. In this paper we employ a single consumer-grade RGBD camera with an ICP-based registration approach to jointly align all points from a sequence of depth images non-rigidly. Subtle body deformation due to postural sway and respiration is successfully mitigated leading to a higher geometric accuracy through regularised locally affine transformations. We present results from 6 clinical cases where our method compares well with the gold standard and outperforms a previous approach. We show that our method produces better reconstructions qualitatively by visual assessment and quantitatively by consistently obtaining lower landmark error scores and yielding more accurate breast volume estimates

Der Toll-like-Rezeptor-4-Signalweg bei Cystischer Fibrose

Mutationen des Gens für den Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), ein cAMP-regulierten Chlorid-Kanal in der apikalen Membran von Epithelzellen sekretorischer Organe, führen zur klinischen Manifestation der letal verlaufenden Erbkrankheit Cystische Fibrose (CF). Diese ist gekennzeichnet durch eine frühe von Neutrophilen dominierte chronische Entzündung der Lunge mit letztlich permanenter bakterieller Besiedlung, vor allem mit Pseudomonas aeruginosa. Dabei lassen die Mutation und der Funktionsverlust des CFTR eine intrinsisch dysregulierte Immunantwort bei CF vermuten. In vivo- und in vitro-Untersuchungen zur Expression von Komponenten der angeborenen Immunabwehr, wie Toll-like Rezeptoren (TLRs) und proinflammatorische Zytokine, liefern widersprüchliche oder nicht aussagekräftige Ergebnisse. Somit ist weiterhin unklar, ob Immunreaktionen bei CF beeinträchtigt oder bereits frühzeitig übermäßig stark aktiviert sind. Im Rahmen dieser Arbeit konnte in einem Zellkulturmodell der bronchialen CF-Epithelzelllinie CFBE und der CFTR-korrigierten Kontrolle gezeigt werden, dass die durch Signaltransduktion über TLR-4 vermittelte Immunreaktion nach Stimulation mit dem Gram-negativen Bakterium P. aeruginosa und dem bakteriellen Zellwandbestandteil LPS bei CF-Zellen beeinträchtigt war. Die CFTR-korrigierten Zellen waren in der Lage, durch dreifache Steigerung der Sekretion von IL-8, IL-6 und IP-10 stärker auf Stimuli von P. aeruginosa zu reagieren als CF-Zellen. Die Ursache der geschwächten Reaktionsfähigkeit bei CF lag in der verringerten Oberflächenexpression von TLR-4, die in einer reduzierten Bindung bakterieller Komponenten und damit in einer verminderten Aktivierung des Transkriptionsfaktors NF-κB resultierte. Die verringerte Oberflächenexpression von TLR-4 ging allerdings nicht mit einer reduzierten mRNA-Expression einher. Vielmehr lagen der Rezeptor oder seine Vorstufen bei CF-Zellen vermehrt intrazellulär vor. Dies ist vermutlich auf Veränderungen im Zusammenhang mit dem Funktionsverlust des CFTR zurückzuführen. Hierbei kommt es zu einem erhöhten intrazellulären pH-Wert, der die Aktivität und Effektivität posttranslationaler Modifikationen wie die Glykosylierung von Membranproteinen beeinträchtigt. Das verringerte Vorliegen von maturem TLR-4 oder erforderlichen Co-Rezeptoren könnte einen reduzierten Einbau in die Zellmembran bedeuten. Zusammenfassend unterstützen die vorliegenden Ergebnisse die Ansicht eines durch den Funktionsverlust des CFTR verursachten Krankheitsbildes bei CF. Die Veränderungen des TLR-4-Signalwegs könnten eine effektive Pathogenabwehr durch sowohl angeborene als auch adaptive Immunität nachhaltig beeinflussen und auf diese Weise eine frühzeitige Infektion und bakterielle Besiedlung der CF-Lunge begünstigen