The effect of alcohol on cervical and ocular vestibular evoked myogenic potentials in healthy volunteers

OBJECTIVE: We investigated the effect of alcohol on the cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs). As alcohol produces gaze-evoked nystagmus (GEN), we also tested the effect of nystagmus independent of alcohol by recording oVEMPs during optokinetic stimulation (OKS). METHODS: The effect of alcohol was tested in 14 subjects over multiple rounds of alcohol consumption up to a maximum breath alcohol concentration (BrAC) of 1.5‰ (mean 0.97‰). The effect of OKS was tested in 11 subjects at 5, 10 and 15deg/sec. RESULTS: oVEMP amplitude decreased from baseline to the highest BrAC level by 27% (range 5-50%, P<0.001), but there was no significant effect on oVEMP latency or cVEMP amplitude or latency. There was a significant negative effect of OKS on oVEMP amplitude (16%, P=0.006). CONCLUSIONS: We found a selective effect of alcohol on oVEMP amplitude, but no effect on the cVEMP. Vertical nystagmus elicited by OKS reduced oVEMP amplitude. SIGNIFICANCE: Alcohol selectively affects oVEMP amplitude. Despite the effects of alcohol and nystagmus, both reflexes were reliably recorded in all subjects and conditions. An absent response in a patient affected by alcohol or nystagmus indicates a vestibular deficit

'Brain Circulation' – Diaspora als treibende Kraft bei der Entwicklung der Herkunftsländer:Seminar "Brain Drain und Brain Gain. Migration und Entwicklung"

Seit Beginn des 21. Jahrhunderts hat die Diskussion über den Zusammenhang von Migration und Entwicklung eine neue Richtung bekommen. Wurde die Emigration von Hochqualifizierten aus Entwicklungsländern bislang zumeist als ein abgeschlossener Prozess gesehen, der für die Abgabeländer in einem Humankapitalverlust (brain drain) und für die Aufnahmeländer (meistenteils Industrieländer) in einem Humankapitalgewinn (brain gain) resultiert, so wird Elitenmigration heute mehr und mehr als ein zirkulärer Prozess der Hin- und Her- bzw. Weiterwanderung angesehen (brain circulation), von dem nicht nur Industrieländer, sondern potentiell auch Entwicklungsländer profitieren können. Alle hier veröffentlichten Arbeiten des Politikwissenschaftsseminars "Brain Drain und Brain Gain. Migration und Entwicklung" unter Leitung von Prof. Thränhardt und Dr. Uwe Hunger aus dem Sommersemester 2005 stellen originäre und eigenständige Forschungsarbeiten dar und tragen durch ihre sorgfältige Recherche dazu bei, weitere neue, wichtige Erkenntnisse für diese immer noch junge Forschungsrichtung zusammenzutragen. Die eigenständigen Arbeiten der Studierenden behandeln ein Thema, das sich in der Forschung gerade durchzusetzen beginnt und Lösungsansätze für die Probleme einer globalisierten und zusammenwachsenden Welt öffnet

Ethanol consumption impairs vestibulo-ocular reflex function measured by the video head impulse test and dynamic visual acuity

Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38‰. All tests were normal at baseline. VOR gain measured by vHIT decreased 25% by the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement.NHMR

No downregulation of immune function during breeding in two year-round breeding bird species in an equatorial East African environment

Some equatorial environments exhibit substantial within-location variation in environmental conditions throughout the year and yet have year-round breeding birds. This implies that breeding in such systems are potentially unrelated to the variable environmental conditions. By breeding not being influenced by environmental conditions, we become sure that any differences in immune function between breeding and non-breeding birds do not result from environmental variation, therefore allowing for exclusion of the confounding effect of variation in environmental conditions. This create a unique opportunity to test if immune function is down-regulated during reproduction compared to non-breeding periods. We compared the immune function of sympatric male and female chick-feeding and non-breeding red-capped Calandrella cinerea and rufous-naped larks Mirafra africana in equatorial East Africa. These closely-related species occupy different niches and have different breeding strategies in the same grassland habitat. Red-capped larks prefer areas with short grass or almost bare ground, and breed during low rainfall periods. Rufous-naped larks prefer areas of tall grass and scattered shrubs and breed during high rainfall. We measured the following immune indices: nitric oxide, haptoglobin, agglutination and lysis, and measured total monthly rain, monthly average minimum (T-min) and maximum (T-max) temperatures. Contrary to our predictions, we found no down-regulation of immune function during breeding; breeding birds had higher nitric oxide than non-breeding ones in both species, while the other three immune indices did not differ between breeding phases. Red-capped larks had higher nitric oxide concentrations than Rufous-naped larks, which in turn had higher haptoglobin levels than red-capped larks. T-max was higher during breeding than during non-breeding for red-capped larks only, suggesting potential confounding effect of T-max on the comparison of immune function between breeding and non-breeding birds for this species. Overall, we conclude that in the two year-round breeding equatorial larks, immune function is not down-regulated during breeding

Distribution of prostate nodes: a PET/CT-derived anatomic atlas of prostate cancer patients before and after surgical treatment

Background: In order to define adequate radiation portals in nodal positive prostate cancer a detailed knowledge of the anatomic lymph-node distribution is mandatory. We therefore systematically analyzed the localization of Choline PET/CT positive lymph nodes and compared it to the RTOG recommendation of pelvic CTV, as well as to previous work, the SPECT sentinel lymph node atlas. Methods: Thirty-two patients being mostly high risk patients with a PSA of 12.5 ng/ml (median) received PET/CT before any treatment. Eighty-seven patients received PET/CT for staging due to biochemical failure with a median PSA of 3.12 ng/ml. Each single PET-positive lymph node was manually contoured in a "virtual" patient dataset to achieve a 3-D visualization, resulting in an atlas of the cumulative PET positive lymph node distribution. Further the PET-positive lymph node location in each patient was assessed with regard to the existence of a potential geographic miss (i.e. PET-positive lymph nodes that would not have been treated adequately by the RTOG consensus on CTV definition of pelvic lymph nodes). Results: Seventy-eight and 209 PET positive lymph nodes were detected in patients with no prior treatment and in postoperative patients, respectively. The most common sites of PET positive lymph nodes in patients with no prior treatment were external iliac (32.1 %), followed by common iliac (23.1 %) and para-aortic (19.2 %). In postoperative patients the most common sites of PET positive lymph nodes were common iliac (24.9 %), followed by external iliac (23.0 %) and para-aortic (20.1 %). In patients with no prior treatment there were 34 (43.6 %) and in postoperative patients there were 77 (36.8 %) of all detected lymph nodes that would not have been treated adequately using the RTOG CTV. We compared the distribution of lymph nodes gained by Choline PET/CT to the preexisting SPECT sentinel lymph node atlas and saw an overall good congruence. Conclusions: Choline PET/CT and SPECT sentinel lymph node atlas are comparable to each other. More than one-third of the PET positive lymph nodes in patients with no prior treatment and in postoperative patients would not have been treated adequately using the RTOG CTV. To reduce geographical miss, image based definition of an individual target volume is necessary

Ordered assembly of the asymmetrically branched lipid-linked oligosaccharide in the endoplasmic reticulum is ensured by the substrate specificity of the individual glycosyltransferases

The assembly of the lipid-linked core oligosaccharide Glc3Man9GlcNAc2, the substrate for N-linked glycosylation of proteins in the endoplasmic reticulum (ER), is catalyzed by different glycosyltransferases located at the membrane of the ER. We report on the identification and characterization of the ALG12 locus encoding a novel mannosyltransferase responsible for the addition of the α-1,6 mannose to dolichollinked Man7GlcNAc2. The biosynthesis of the highly branched oligosaccharide follows an ordered pathway which ensures that only completely assembled oligosaccharide is transferred from the lipid anchor to proteins. Using the combination of mutant strains affected in the assembly pathway of lipid-linked oligosaccharides and overexpression of distinct glycosyltransferases, we were able to define the substrate specificities of the transferases that are critical for branching. Our results demonstrate that branched oligosaccharide structures can be specifically recognized by the ER glycosyltransferases. This substrate specificity of the different transferases explains the ordered assembly of the complex structure of lipid-linked Glc3Man9GlcNAc2 in the endoplasmic reticulu

DNA content of a functioning chicken kinetochore

© The Author(s) 2014. In order to understand the three-dimensional structure of the functional kinetochore in vertebrates, we require a complete list and stoichiometry for the protein components of the kinetochore, which can be provided by genetic and proteomic experiments. We also need to know how the chromatin-containing CENP-A, which makes up the structural foundation for the kinetochore, is folded, and how much of that DNA is involved in assembling the kinetochore. In this MS, we demonstrate that functioning metaphase kinetochores in chicken DT40 cells contain roughly 50 kb of DNA, an amount that corresponds extremely closely to the length of chromosomal DNA associated with CENP-A in ChIP-seq experiments. Thus, during kinetochore assembly, CENP-A chromatin is compacted into the inner kinetochore plate without including significant amounts of flanking pericentromeric heterochromatin. © 2014 The Author(s).Wellcome Trust [grant number 073915]; Wellcome Trust Centre for Cell Biology (core grant numbers 077707 and 092076); Darwin Trust of Edinburg

Are Dutch Skylarks partial migrants? Ring recovery data and radio-telemetry suggest local coexistence of contrasting migration strategies

In western Europe, farmland birds have declined in recent decades by almost 50% (BirdLife International 2004, EBCC 2009, PECBMS 2009. While declines are frequently associated with changed or changing conditions during the breeding season and deterioration of the breeding habitat In The Netherlands, the Skylark Alauda arvensis is one of the farmland species with the steepest decline: numbers dropped by almost 95% from around 700,000 Are Dutch Skylarks partial migrants? Ring recovery data and radio-telemetry suggest local coexistence of contrasting migration strategies In recent years, Skylarks Alauda arvensis have undergone dramatic population declines in many European countries. Evidence exists for deteriorating conditions during the breeding season, but little is known about the situation during the rest of the annual cycle. Here we use two approaches to test if the Dutch breeding population of Skylarks consists of resident and/or migratory individuals. First, we present an analysis of ring recoveries from the Dutch Ringing Centre &quot;Vogeltrekstation&quot;. Out of 25 recoveries, 12 Skylarks were resident in winter, 10 migrated and three were classified as probable migrants. Resident birds were accompanied during winter by birds from northern and eastern Europe. Very limited natal and breeding dispersal recorded in the same dataset suggests that our results were not influenced by long dispersal distances. Next, we compared these results to a local radio-telemetry study in the northern Netherlands. During two different years we equipped a total of 27 Skylarks from a breeding population with radio-transmitters and followed them during the subsequent winter. Four birds were found to winter locally. Out of 23 individuals that we did not find in winter, 14 returned in the following breeding season to the study area, all with a working transmitter, suggesting that they wintered outside our study area. Two ring recoveries of birds from the same study population indeed showed migration to south-west Europe. Based on these two lines of evidence, we conclude local coexistence of a resident and a migrant strategy in Dutch Skylarks. The findings of our study are important for the planning of conservation efforts, as we can only protect this rapidly declining species when we know their behaviour and whereabouts throughout the entire annual cycle. Skylark populations from northern Europe migrate to south-west Europe, mainly to France and Spain, whereas southern European and British populations are thought to be resident Futhermore, it is unclear whether resident and migratory strategies occur within a single Skylark population. Partial migration is defined as occurring when one part of the population remains in the breeding area year round and another part migrates In this study we investigated migration strategies of Skylarks in The Netherlands using two different approaches. First, we analysed all ring recoveries of Skylarks from the database of the Dutch ringing centre &quot;Vogeltrekstation&quot;. Second, we conducted a radio-telemetry study in a local breeding population of Skylarks in the northern Netherlands. We combine the results of both approaches to evaluate whether Skylarks that breed in The Netherlands migrate or winter locally. Additionally, we analyse the ring recoveries of Skylarks that spend the winter in The Netherlands, to trace their origin. Finally, we present data on natal and breeding dispersal of Skylarks ringed in The Netherlands during the breeding season to verify that our results on the migratory strategies of Skylarks are not in fact influenced by long-distance dispersal. METHODS Ring recoveries Since 1911 more than 88,000 Skylarks have been ringed in The Netherlands (Vogeltrekstation data until November 2008), of which 497 were recovered. The database contains an additional 35 recoveries of birds ringed in other countries and found in The Netherlands. We selected all cases where distinction between migration strategies (resident in winter vs. migrant) is possible (n = 25, Appendix 1). These include birds that were (1) ringed during the breeding season in The Netherlands (either as nestling or as breeding adult) and recovered in any winter, or during any autumn or spring migration; (2) ringed during winter and reported during the breeding season in The Netherlands; and (3) ringed during migration and recovered during the breeding season within The Netherlands. We define migration based on distance between ringing and recovery site by visually deriving a divide in travelled distance between residents and migrants (see To evaluate whether, in addition to Dutch birds, Skylarks from northern origins also winter in The Netherlands, we selected all birds that were ringed during winter (20 Nov -29 Jan) in The Netherlands and were later recovered further north. We additionally checked for the origin of late migrants (1 Nov -19 Nov). If long-distance natal or breeding dispersal occurs in Skylarks, this could potentially influence our results given the selection criteria we used to classify migrants. Therefore we performed an analysis of natal and breeding dispersal by selecting all recoveries from birds ringed during the breeding season as either nestlings or adults and that were recovered during any subsequent breeding season (n = 43). Of these 43 recoveries, 23 birds were found by the ringer and 20 by another person, and thus estimated dispersal is not only based on birds recaptured by a ringer within a study population. Study area for radiotelemetry We obtained detailed information on a breeding population in the &quot;Aekingerzand&quot;, part of the National Park Drents-Friese Wold in the northern Netherlands (52°55&apos;N; 6°18&apos;E). The area is a mixture of open sand, groups of trees, heath-and grasslands on nutrient-poor soil and surrounded by a thin belt of forests. The wider surroundings are characterised by agricultural fields and small villages. The study population consists of about 100 pairs; the vast majority of individuals are colour-ringed. Radio-tracking We equipped 28 Skylarks with radio-transmitters. Eight birds (3 adult males, 4 adult females, 1 juvenile female) received the transmitter in the period 13 Jul -26 Sep 2007 and another 20 (9 adult males, 4 adult females, 4 juvenile males, 2 juvenile females and 1 male of unknown age) in the period 3 Aug -22 Sep 2008 when all birds showed active moult. Ageing of the birds was based on previous ringing or on plumage characteristics; sex was determined by wing length and in doubtful cases confirmed by molecular sexing. The radio-transmitters (172 MHz-band) were specifically designed for this project by JDJC Corp. d.b.a. Sparrow Systems, United States. The life-time was assumed by the manufacturer to be at least 6-7 months. In fact, in all cases where birds returned to the breeding grounds, transmitters continued to work for longer than this expected life-span and one transmitter was still working one year after attachment. Transmitters were fixed on the back of a bird using figure-eight-harnesses (Rappole &amp; Tipton 1991) made from elasticated cotton thread. Transmitters, including harness, ranged in weight from 1.29 to 1.50 g, equalling 3.1-5.2% of a bird&apos;s body weight at time of attachment. During the period when transmitters were attached, Skylarks in this study population are close to their minimum weight in the annual cycle (A. Hegemann, unpubl.). From when transmitters were attached until the end of September we carried out repeated searches for birds in the study area to check if birds were still present and to determine if transmitters produced regular signals on the supposed frequency. One transmitter attached to a bird in 2007 failed to work properly due to an antenna that was broken two weeks after attachment. Therefore we excluded this bird from further analysis. Starting in October when birds left the Aekingerzand, we searched for radio-tagged birds using two portable ICOM IC-R20-receivers with hand-held 5-element yagi-antennas. In a radius of up to 8 km around the Aekingerzand, the agricultural landscape was checked for the presence of radio-tagged birds by one person searching for 4-5 days per week and about five hours per day. In the open landscape (excluding villages and wooded areas) we scanned for all used frequencies, conducting scans at regular distances of not more than 1 km apart. In addition we used a dipole antenna mounted on the roof of a car with a automatically scanning receiver to search for birds while driving around the search area. During winter 2008/09 the hand-held antenna was mounted on a 4-m long plastic pole to increase reception. Furthermore we conducted telemetry from a small aircraft (Cessna skyhawk), flying for 2-4 hours at a height of 250-300 m and with a speed of 100-110 km/h in circles over the study area. Flights were completed once in winter 2007/08 (on 8 December) and twice in winter 2008/09 (on 16 January and 6 February). With these flights we covered an area with a radius of about 12 km around the Aekingerzand. During the flight on 8 December 2007 we received signals from one bird we did not find previously by ground telemetry. During the two flights in winter 2008/09 we did not find any additional birds. During all flights radio-tagged birds with known location, or one additional transmitter that was not attached to a 137 bird, were used as references values. From the air we were able to detect these references signals from a distance of at least 2 km. Another search flight was flown in spring 2009 (on 3 March) to search for potentially dispersed birds, but none were found. RESULTS Migration strategies from ringing data Based on 25 ring recoveries, we classified 12 birds as residents, 10 as migrants and three as probable migrants Origin of birds wintering in The Netherlands Eleven birds ringed in winter in The Netherlands were recovered in or on their way towards breeding areas outside The Netherlands, in Denmark (n = 8), Russia (n = 1), Sweden (n = 1) and Norway (n = 1) (Appendix 2). Additionally two birds ringed during the breeding season in Denmark and Norway, respectively, were found in winter in The Netherlands. Furthermore, birds that were ringed during the last part of the southward migration period in The Netherlands (1 Nov -19 Nov) were later reported in Denmark (n = 8) and Russia (n = 1) (Appendix 2). Natal and breeding philopatry Thirty Skylarks ringed as nestlings were reported during a later year as breeding birds. Twenty-six of these birds (1 male, 18 female, 7 unknown) were found within 4 km of the ringing site, and four (all unknown sex) had dispersed further than 10 km from the place of hatching. The furthest recovery was found in a fresh pellet of a Montagu&apos;s Harrier Circus pygargus one year after being ringed as a nestling, at a distance of 41 km from its place of hatching (H.J. Ottens, pers. comm.). Because Montagu&apos;s Harriers of this specific population hunt over distances of more than 18 km from their nest site (C. Trierweiler, pers. comm.), the actual dispersal distance of this bird remains uncertain. Of the 13 birds ringed as adults (5 males, 7 females, 1 unknown) during the breeding season all were reported in subsequent years within 2 km of the site of ringing. Radio-telemetry of Aekingerzand population In the winter of 2007/08 all radio-tagged birds had left the Aekingerzand by 2 October. In the course of the winter we detected signals from three of the seven radio-tagged birds (43%) at distances of 0-9 km from the Aekingerzand. These included two adult males and one adult female ( In the winter of 2008/09 we located only one of the 20 radio-tagged birds in the search area around the Aekingerzand (5%, Both winters combined, we found three of 17 males and one of 10 females to winter locally (Fisher&apos;s Exact Test, P = 1). Four adults were found to winter locally, while we did not detect any of the seven juveniles in winter (Fisher&apos;s Exact Test, P = 0.55). The proportion of birds we found in our study area during winter, differed between the two years (Fisher&apos;s Exact Test, P = 0.04). DISCUSSION Ring recoveries from the entire Netherlands for the past 100 years clearly demonstrate that Dutch Skylarks are partial migrants; some birds migrate to the southwest and others winter close to their breeding grounds. Our radio-telemetry study on a local breeding population in the northern part of The Netherlands confirmed that some birds winter very close to the breeding location while others were not found in winter in the immediat

Synthetic retinal analogues modify the spectral and kinetic characteristics of microbial rhodopsin optogenetic tools

Optogenetic tools have become indispensable in neuroscience to stimulate or inhibit excitable cells by light. Channelrhodopsin-2 (ChR2) variants have been established by mutating the opsin backbone or by mining related algal genomes. As an alternative strategy, we surveyed synthetic retinal analogues combined with microbial rhodopsins for functional and spectral properties, capitalizing on assays in C. elegans, HEK cells and larval Drosophila. Compared with all-trans retinal (ATR), Dimethylamino-retinal (DMAR) shifts the action spectra maxima of ChR2 variants H134R and H134R/T159C from 480 to 520 nm. Moreover, DMAR decelerates the photocycle of ChR2(H134R) and (H134R/T159C), thereby reducing the light intensity required for persistent channel activation. In hyperpolarizing archaerhodopsin-3 and Mac, naphthyl-retinal and thiophene-retinal support activity alike ATR, yet at altered peak wavelengths. Our experiments enable applications of retinal analogues in colour tuning and altering photocycle characteristics of optogenetic tools, thereby increasing the operational light sensitivity of existing cell lines or transgenic animals