TY - JOUR A1 - Huss, André M. A1 - Halbgebauer, Steffen A1 - Öckl, Patrick A1 - Trebst, Corinna A1 - Spreer, Annette A1 - Borisow, Nadja A1 - Harrer, Andrea A1 - Brecht, Isabel A1 - Balint, Bettina A1 - Stich, Oliver A1 - Schlegel, Sabine A1 - Retzlaff, Nele A1 - Winkelmann, Alexander A1 - Roesler, Romy A1 - Lauda, Florian A1 - Yildiz, Özlem A1 - Voß, Elke A1 - Muche, Rainer A1 - Rauer, Sebastian A1 - Bergh, Florian Then A1 - Otto, Markus A1 - Paul, Friedemann A1 - Wildemann, Brigitte A1 - Kraus, Jörg A1 - Ruprecht, Klemens A1 - Stangel, Martin A1 - Buttmann, Mathias A1 - Zettl, Uwe K. A1 - Tumani, Hayrettin T1 - Importance of cerebrospinal fluid analysis in the era of McDonald 2010 criteria: a German-Austrian retrospective multicenter study in patients with a clinically isolated syndrome JF - Journal of Neurology N2 - The majority of patients presenting with a first clinical symptom suggestive of multiple sclerosis (MS) do not fulfill the MRI criteria for dissemination in space and time according to the 2010 revision of the McDonald diagnostic criteria for MS and are thus classified as clinically isolated syndrome (CIS). To re-evaluate the utility of cerebrospinal fluid (CSF) analysis in the context of the revised McDonald criteria from 2010, we conducted a retrospective multicenter study aimed at determining the prevalence and predictive value of oligoclonal IgG bands (OCBs) in patients with CIS. Patients were recruited from ten specialized MS centers in Germany and Austria. We collected data from 406 patients; at disease onset, 44/406 (11 %) fulfilled the McDonald 2010 criteria for MS. Intrathecal IgG OCBs were detected in 310/362 (86 %) of CIS patients. Those patients were twice as likely to convert to MS according to McDonald 2010 criteria as OCB-negative individuals (hazard ratio = 2.1, p = 0.0014) and in a shorter time period of 25 months (95 % CI 21-34) compared to 47 months in OCB-negative individuals (95 % CI 36-85). In patients without brain lesions at first attack and presence of intrathecal OCBs (30/44), conversion rate to MS was 60 % (18/30), whereas it was only 21 % (3/14) in those without OCBs. Our data confirm that in patients with CIS the risk of conversion to MS substantially increases if OCBs are present at onset. CSF analysis definitely helps to evaluate the prognosis in patients who do not have MS according to the revised McDonald criteria. KW - multiple sklerosis KW - MRI criteria KW - conversion KW - MS KW - CSF KW - biomarker KW - OCB Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186619 VL - 263 IS - 12 ER - TY - JOUR A1 - Perkovic, Vlado A1 - Agarwal, Rajiv A1 - Fioretto, Paola A1 - Hemmelgarn, Brenda R. A1 - Levin, Adeera A1 - Thomas, Merlin C. A1 - Wanner, Christoph A1 - Kasiske, Bertram L. A1 - Wheeler, David C. A1 - Groop, Per-Henrik T1 - Management of patients with diabetes and CKD: conclusions from a "Kidney Disease: Improving Global Outcomes" (KDIGO) controversies conference JF - Kidney International N2 - The prevalence of diabetes around the world has reached epidemic proportions and is projected to increase to 642 million people by 2040. Diabetes is already the leading cause of end-stage kidney disease (ESKD) in most developed countries, and the growth in the number of people with ESKD around the world parallels the increase in diabetes. The presence of kidney disease is associated with a markedly elevated risk of cardiovascular disease and death in people with diabetes. Several new therapies and novel investigational agents targeting chronic kidney disease patients with diabetes are now under development. This conference was convened to assess our current state of knowledge regarding optimal glycemic control, current antidiabetic agents and their safety, and new therapies being developed to improve kidney function and cardiovascular outcomes for this vulnerable population. KW - stage renal-disease KW - converting enzyme-inhibition KW - dietary sodium restriction KW - intensive glucose control KW - albumin excretion rate KW - blood pressure KW - cardiovascular outcomes KW - randomized trial KW - glycemic control KW - receptor KW - antidiabetic agents KW - cardiovascular disease KW - chronic kidney disease KW - diabetes KW - renoprotection KW - antagonist Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186599 VL - 90 IS - 6 ER - TY - JOUR A1 - Ansell, Melvyn B. A1 - Kostakis, George E. A1 - Braunschweig, Holger A1 - Navarro, Oscar A1 - Spencer, John T1 - Synthesis of functionalized hydrazines: facile homogeneous (N-heterocyclic carbene)-palladium(0)-catalyzed diboration and silaboration of azobenzenes JF - Advanced Synthesis & Catalysis N2 - The bis(N-heterocyclic carbene)(diphenylacetylene)palladium complex Pd(ITMe)\(_2\)(PhCCPh)] (ITMe=1,3,4,5-tetramethylimidazol-2-ylidene) acts as a highly active pre-catalyst in the diboration and silaboration of azobenzenes to synthesize a series of novel functionalized hydrazines. The reactions proceed using commercially available diboranes and silaboranes under mild reaction conditions. KW - Palladium-catalyzed silaboration KW - B-B bond KW - molecular-structure KW - terminal alkynes KW - crystal-structure KW - alkenes KW - complexes KW - mechanism KW - boron KW - design KW - azobenzenes KW - dilaboration KW - N-heterocyclic carbenes KW - palladium KW - silaboration Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186582 VL - 358 IS - 23 ER - TY - JOUR A1 - Jarius, Sven A1 - Ruprecht, Klemens A1 - Kleiter, Ingo A1 - Borisow, Nadja A1 - Asgari, Nasrin A1 - Pitarokoili, Kalliopi A1 - Pache, Florence A1 - Stich, Oliver A1 - Beume, Lena-Alexandra A1 - Hümmert, Martin W. A1 - Ringelstein, Marius A1 - Trebst, Corinna A1 - Winkelmann, Alexander A1 - Schwarz, Alexander A1 - Buttmann, Mathias A1 - Zimmermann, Hanna A1 - Kuchling, Joseph A1 - Franciotta, Diego A1 - Capobianco, Marco A1 - Siebert, Eberhard A1 - Lukas, Carsten A1 - Korporal-Kuhnke, Mirjam A1 - Haas, Jürgen A1 - Fechner, Kai A1 - Brandt, Alexander U. A1 - Schanda, Kathrin A1 - Aktas, Orhan A1 - Paul, Friedemann A1 - Reindl, Markus A1 - Wildemann, Brigitte T1 - MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 2: Epidemiology, clinical presentation, radiological and laboratory features, treatment responses, and long-term outcome JF - Journal of Neuroinflammation N2 - Background A subset of patients with neuromyelitis optica spectrum disorders (NMOSD) has been shown to be seropositive for myelin oligodendrocyte glycoprotein antibodies (MOG-IgG). Objective To describe the epidemiological, clinical, radiological, cerebrospinal fluid (CSF), and electrophysiological features of a large cohort of MOG-IgG-positive patients with optic neuritis (ON) and/or myelitis (n = 50) as well as attack and long-term treatment outcomes. Methods Retrospective multicenter study. Results The sex ratio was 1:2.8 (m:f). Median age at onset was 31 years (range 6-70). The disease followed a multiphasic course in 80% (median time-to-first-relapse 5 months; annualized relapse rate 0.92) and resulted in significant disability in 40% (mean follow-up 75 ± 46.5 months), with severe visual impairment or functional blindness (36%) and markedly impaired ambulation due to paresis or ataxia (25%) as the most common long-term sequelae. Functional blindness in one or both eyes was noted during at least one ON attack in around 70%. Perioptic enhancement was present in several patients. Besides acute tetra-/paraparesis, dysesthesia and pain were common in acute myelitis (70%). Longitudinally extensive spinal cord lesions were frequent, but short lesions occurred at least once in 44%. Fourty-one percent had a history of simultaneous ON and myelitis. Clinical or radiological involvement of the brain, brainstem, or cerebellum was present in 50%; extra-opticospinal symptoms included intractable nausea and vomiting and respiratory insufficiency (fatal in one). CSF pleocytosis (partly neutrophilic) was present in 70%, oligoclonal bands in only 13%, and blood-CSF-barrier dysfunction in 32%. Intravenous methylprednisolone (IVMP) and long-term immunosuppression were often effective; however, treatment failure leading to rapid accumulation of disability was noted in many patients as well as flare-ups after steroid withdrawal. Full recovery was achieved by plasma exchange in some cases, including after IVMP failure. Breakthrough attacks under azathioprine were linked to the drug-specific latency period and a lack of cotreatment with oral steroids. Methotrexate was effective in 5/6 patients. Interferon-beta was associated with ongoing or increasing disease activity. Rituximab and ofatumumab were effective in some patients. However, treatment with rituximab was followed by early relapses in several cases; end-of-dose relapses occurred 9-12 months after the first infusion. Coexisting autoimmunity was rare (9%). Wingerchuk’s 2006 and 2015 criteria for NMO(SD) and Barkhof and McDonald criteria for multiple sclerosis (MS) were met by 28%, 32%, 15%, 33%, respectively; MS had been suspected in 36%. Disease onset or relapses were preceded by infection, vaccination, or pregnancy/delivery in several cases. Conclusion Our findings from a predominantly Caucasian cohort strongly argue against the concept of MOG-IgG denoting a mild and usually monophasic variant of NMOSD. The predominantly relapsing and often severe disease course and the short median time to second attack support the use of prophylactic long-term treatments in patients with MOG-IgG-positive ON and/or myelitis. KW - Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) KW - Aquaporin-4 antibodies (AQP4-IgG, NMO-IgG) KW - Optic neuritis KW - Transverse myelitis KW - Longitudinally extensive transverse myelitis KW - Magnetic resonance imaging KW - Autoantibodies KW - Neuromyelitis optica spectrum disorders (NMOSD) KW - Cerebrospinal fluid KW - Oligoclonal bands KW - Electrophysiology KW - Evoked potentials KW - Treatment KW - Therapy KW - Methotrexate KW - Azathioprine KW - Rituximab KW - Ofatumumab KW - Interferon beta KW - Glatiramer acetate KW - Natalizumab KW - Outcome KW - Pregnancy KW - Infections KW - Vaccination KW - Multiple sclerosis KW - Barkhof criteria KW - McDonald criteria KW - Wingerchuk criteria 2006 and 2015 KW - IPND criteria KW - International consensus diagnostic criteria for neuromyelitis optica spectrum disorders Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165570 VL - 13 IS - 280 ER - TY - JOUR A1 - Pache, Florence A1 - Zimmermann, Hanna A1 - Mikolajczak, Janine A1 - Schumacher, Sophie A1 - Lacheta, Anna A1 - Oertel, Frederike C. A1 - Bellmann-Strobl, Judith A1 - Jarius, Sven A1 - Wildemann, Brigitte A1 - Reindl, Markus A1 - Waldman, Amy A1 - Soelberg, Kerstin A1 - Asgari, Nasrin A1 - Ringelstein, Marius A1 - Aktas, Orhan A1 - Gross, Nikolai A1 - Buttmann, Mathias A1 - Ach, Thomas A1 - Ruprecht, Klemens A1 - Paul, Friedemann A1 - Brandt, Alexander U. T1 - MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 4: Afferent visual system damage after optic neuritis in MOG-IgG-seropositive versus AQP4-IgG-seropositive patients JF - Journal of Neuroinflammation N2 - Background Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been reported in patients with aquaporin-4 antibody (AQP4-IgG)-negative neuromyelitis optica spectrum disorders (NMOSD). The objective of this study was to describe optic neuritis (ON)-induced neuro-axonal damage in the retina of MOG-IgG-positive patients in comparison with AQP4-IgG-positive NMOSD patients. Methods Afferent visual system damage following ON was bilaterally assessed in 16 MOG-IgG-positive patients with a history of ON and compared with that in 16 AQP4-IgG-positive NMOSD patients. In addition, 16 healthy controls matched for age, sex, and disease duration were analyzed. Study data included ON history, retinal optical coherence tomography, visual acuity, and visual evoked potentials. Results Eight MOG-IgG-positive patients had a previous diagnosis of AQP4-IgG-negative NMOSD with ON and myelitis, and eight of (mainly recurrent) ON. Twenty-nine of the 32 eyes of the MOG-IgG-positive patients had been affected by at least one episode of ON. Peripapillary retinal nerve fiber layer thickness (pRNFL) and ganglion cell and inner plexiform layer volume (GCIP) were significantly reduced in ON eyes of MOG-IgG-positive patients (pRNFL = 59 ± 23 μm; GCIP = 1.50 ± 0.34 mm3) compared with healthy controls (pRNFL = 99 ± 6 μm, p < 0.001; GCIP = 1.97 ± 0.11 mm3, p < 0.001). Visual acuity was impaired in eyes after ON in MOG-IgG-positive patients (0.35 ± 0.88 logMAR). There were no significant differences in any structural or functional visual parameters between MOG-IgG-positive and AQP4-IgG-positive patients (pRNFL: 59 ± 21 μm; GCIP: 1.41 ± 0.27 mm3; Visual acuity = 0.72 ± 1.09 logMAR). Importantly, MOG-IgG-positive patients had a significantly higher annual ON relapse rate than AQP4-IgG-positive patients (median 0.69 vs. 0.29 attacks/year, p = 0.004), meaning that on average a single ON episode caused less damage in MOG-IgG-positive than in AQP4-IgG-positive patients. pRNFL and GCIP loss correlated with the number of ON episodes in MOG-IgG-positive patients (p < 0.001), but not in AQP4-IgG-positive patients. Conclusions Retinal neuro-axonal damage and visual impairment after ON in MOG-IgG-positive patients are as severe as in AQP4-IgG-positive NMOSD patients. In MOG-IgG-positive patients, damage accrual may be driven by higher relapse rates, whereas AQP4-IgG-positive patients showed fewer but more severe episodes of ON. Given the marked damage in some of our MOG-IgG-positive patients, early diagnosis and timely initiation and close monitoring of immunosuppressive therapy are important. KW - Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) KW - aquaporin-4 antibodies (AQP4-IgG) KW - NMO-IgG KW - neuromyelitis optica KW - Devic syndrome KW - neuromyelitis optica spectrum disorders (NMOSD) KW - optic neuritis KW - optical coherence tomography KW - visual evoked potentials KW - visual acuity KW - retinal neuro-axonal damage Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165551 VL - 13 IS - 282 ER - TY - JOUR A1 - Sterkenburg, Anthe S. A1 - Hoffmann, Anika A1 - Reichel, Julia A1 - Lohle, Kristin A1 - Eveslage, Maria A1 - Warmuth-Metz, Monika A1 - Müller, Hermann L. T1 - Nuchal skinfold thickness: A novel parameter for assessment of body composition in childhood craniopharyngioma JF - Journal of Clinical Endocrinology & Metabolism N2 - Context: Hypothalamic obesity, cardiovascular disease (CVD), and relapse/progression have a major impact on prognosis in childhood-onset craniopharyngioma (CP). We analyzed nuchal skinfold thickness (NST) on magnetic resonance imaging performed for follow-up monitoring as a novel parameter for body composition (BC) and CVD in CP. Objective: The objective of the study was to identify the association of NST with body mass index (BMI), waist to height ratio (WHtR), functional capacity, and blood pressure (BP) in CP and controls. Design: This was a cross-sectional and longitudinal prospective study in CP patients. Setting: The study was conducted at HIT-Endo, KRANIOPHARYNGEOM 2000/2007. Patients: Participants included 94 CP patients and 75 controls. Interventions: There were no interventions. Main Outcome Measures: Association of NST with BC and BP in 43 CP and 43 controls was measured. Results: NST correlated with BMI SD score (SDS; r = 0.78; P = .001; n = 169) and WHtR (r = 0.85; P = .001; n = 86) in the total cohort and CP patients (NST-BMI SDS: r = 0.77, P = .001, n = 94); NST-WHtR: r = 0.835, P = .001, n = 43) and controls (NST-BMI SDS: r = 0.792, P = .001, n = 75; NST-WHtR: r = 0.671, P = .001, n = 43). In CP, systolic BP correlated with NST (r = 0.575, P = .001), BMI SDS (r = 0.434, P = .004), and WHtR (r = 0.386, P = .011). Similar results were observed for diastolic BP in CP. In multivariate analyses, NST had a predictive value for hypertension in postpubertal CP and controls (odds ratio 6.98, 95% confidence interval 1.65, 29.5], P = .008). During a longitudinal follow-up, changes in NST correlated with changes in BMI SDS (P = .001) and WHtR (P = .01) but not with changes in BP and functional capacity. Conclusions: Because monitoring of magnetic resonance imaging and BC is essential for follow-up in CP, NST could serve as a novel and clinically relevant parameter for longitudinal assessment of BC and CVD risk in CP. KW - to-height ratio KW - subcutaneous adipose-tissue KW - disease risk-factors KW - long-term survivors KW - guality-of-life KW - mass index KW - neck circumference KW - onset craniopharyngioma KW - german multicenter KW - visceral adiposity Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186562 VL - 101 IS - 12 ER - TY - JOUR A1 - Appel, Mirjam A1 - Scholz, Claus-Jürgen A1 - Kocabey, Samet A1 - Savage, Sinead A1 - König, Christian A1 - Yarali, Ayse T1 - Independent natural genetic variation of punishment- versus relief-memory JF - Biology Letters N2 - A painful event establishes two opponent memories: cues that are associated with pain onset are remembered negatively, whereas cues that coincide with the relief at pain offset acquire positive valence. Such punishment-versus relief-memories are conserved across species, including humans, and the balance between them is critical for adaptive behaviour with respect to pain and trauma. In the fruit fly, Drosophila melanogaster as a study case, we found that both punishment-and relief-memories display natural variation across wild-derived inbred strains, but they do not covary, suggesting a considerable level of dissociation in their genetic effectors. This provokes the question whether there may be heritable inter-individual differences in the balance between these opponent memories in man, with potential psycho-clinical implications. KW - associative memory KW - Drosophila melanogaster KW - natural genetic variation KW - opponent processes KW - punishment KW - fruit-flies KW - relief KW - reward KW - rats Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186554 VL - 12 IS - 12 ER - TY - JOUR A1 - Müller, Stefanie H. A1 - Girard, Simon L. A1 - Hopfner, Franziska A1 - Merner, Nancy D. A1 - Bourassa, Cynthia V. A1 - Lorenz, Delia A1 - Clark, Lorraine N. A1 - Tittmann, Lukas A1 - Soto-Ortolaza, Alexandra I. A1 - Klebe, Stephan A1 - Hallett, Mark A1 - Schneider, Susanne A. A1 - Hodgkinson, Colin A. A1 - Lieb, Wolfgang A1 - Wszolek, Zbigniew K. A1 - Pendziwiat, Manuela A1 - Lorenzo-Betancor, Oswaldo A1 - Poewe, Werner A1 - Ortega-Cubero, Sara A1 - Seppi, Klaus A1 - Rajput, Alex A1 - Hussl, Anna A1 - Rajput, Ali H. A1 - Berg, Daniela A1 - Dion, Patrick A. A1 - Wurster, Isabel A1 - Shulman, Joshua M. A1 - Srulijes, Karin A1 - Haubenberger, Dietrich A1 - Pastor, Pau A1 - Vilariño-Güell, Carles A1 - Postuma, Ronald B. A1 - Bernard, Geneviève A1 - Ladwig, Karl-Heinz A1 - Dupré, Nicolas A1 - Jankovic, Joseph A1 - Strauch, Konstantin A1 - Panisset, Michel A1 - Winkelmann, Juliane A1 - Testa, Claudia M. A1 - Reischl, Eva A1 - Zeuner, Kirsten E. A1 - Ross, Owen A. A1 - Arzberger, Thomas A1 - Chouinard, Sylvain A1 - Deuschl, Günther A1 - Louis, Elan D. A1 - Kuhlenbäumer, Gregor A1 - Rouleau, Guy A. T1 - Genome-wide association study in essential tremor identifies three new loci JF - Brain N2 - We conducted a genome-wide association study of essential tremor, a common movement disorder characterized mainly by a postural and kinetic tremor of the upper extremities. Twin and family history studies show a high heritability for essential tremor. The molecular genetic determinants of essential tremor are unknown. We included 2807 patients and 6441 controls of European descent in our two-stage genome-wide association study. The 59 most significantly disease-associated markers of the discovery stage were genotyped in the replication stage. After Bonferroni correction two markers, one (rs10937625) located in the serine/threonine kinase STK32B and one (rs17590046) in the transcriptional coactivator PPARGC1A were associated with essential tremor. Three markers (rs12764057, rs10822974, rs7903491) in the cell-adhesion molecule CTNNA3 were significant in the combined analysis of both stages. The expression of STK32B was increased in the cerebellar cortex of patients and expression quantitative trait loci database mining showed association between the protective minor allele of rs10937625 and reduced expression in cerebellar cortex. We found no expression differences related to disease status or marker genotype for the other two genes. Replication of two lead single nucleotide polymorphisms of previous small genome-wide association studies (rs3794087 in SLC1A2, rs9652490 in LINGO1) did not confirm the association with essential tremor. KW - quality-control KW - disease KW - tool KW - movement disorders KW - genome-wide association study KW - tremor KW - genetics KW - essential tremor Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186541 VL - 139 ER - TY - JOUR A1 - Wheeler, Nicole E. A1 - Barquist, Lars A1 - Kingsley, Robert A. A1 - Gardner, Paul P. T1 - A profile-based method for identifying functional divergence of orthologous genes in bacterial genomes JF - Bioinformatics N2 - Motivation: Next generation sequencing technologies have provided us with a wealth of information on genetic variation, but predi cting the functional significance of this variation is a difficult task. While many comparative genomics studies have focused on gene flux and large scale changes, relatively little attention has been paid to quantifying the effects of single nucleotide polymorphisms and indels on protein function, particularly in bacterial genomics. Results: We present a hidden Markov model based approach we call delta-bitscore (DBS) for identifying orthologous proteins that have diverged at the amino acid sequence level in a way that is likely to impact biological function. We benchmark this approach with several widely used datasets and apply it to a proof-of-concept study of orthologous proteomes in an investigation of host adaptation in Salmonella enterica. We highlight the value of the method in identifying functional divergence of genes, and suggest that this tool may be a better approach than the commonly used dN/dS metric for identifying functionally significant genetic changes occurring in recently diverged organisms. KW - Host adaptation KW - Salmonella-enteritidis KW - Sequence identity KW - Rapid evolution KW - Variants KW - Cystic-fibriosis KW - Strains KW - Pathogenicity KW - Typhimurium KW - Yersinia Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186502 VL - 32 IS - 23 ER - TY - JOUR A1 - Vaze, Koustubh M. A1 - Helfrich-Förster, Charlotte T1 - Drosophila ezoana uses an hour-glass or highly damped circadian clock for measuring night length and inducing diapause JF - Physiological Entomology N2 - Insects inhabiting the temperate zones measure seasonal changes in day or night length to enter the overwintering diapause. Diapause induction occurs after the duration of the night exceeds a critical night length (CNL). Our understanding of the time measurement mechanisms is continuously evolving subsequent to Bünning’s proposal that circadian systems play the clock role in photoperiodic time measurement (Bünning, 1936). Initially, the photoperiodic clocks were considered to be either based on circadian oscillators or on simple hour-glasses, depending on ‘positive’ or ‘negative’ responses in Nanda–Hamner and Bünsow experiments (Nanda & Hammer, 1958; Bünsow, 1960). However, there are also species whose responses can be regarded as neither ‘positive’, nor as ‘negative’, such as the Northern Drosophila species Drosophila ezoana, which is investigated in the present study. In addition, modelling efforts show that the ‘positive’ and ‘negative’ Nanda–Hamner responses can also be provoked by circadian oscillators that are damped to different degrees: animals with highly sustained circadian clocks will respond ‘positive’ and those with heavily damped circadian clocks will respond ‘negative’. In the present study, an experimental assay is proposed that characterizes the photoperiodic oscillators by determining the effects of non-24-h light/dark cycles (T-cycles) on critical night length. It is predicted that there is (i) a change in the critical night length as a function of T-cycle period in sustained-oscillator-based clocks and (ii) a fxed night-length measurement (i.e. no change in critical night length) in damped-oscillator-based clocks. Drosophila ezoana flies show a critical night length of approximately 7 h irrespective of T-cycle period, suggesting a damped-oscillator-based photoperiodic clock. The conclusion is strengthened by activity recordings revealing that the activity rhythm of D. ezoana flies also dampens in constant darkness. KW - photoperiodic time mesurement KW - wyeomyia smithii KW - protophormia terraenovae KW - immunoreactive neurons KW - geographical variation KW - reproductive diapause KW - rhythmic components KW - locomotor activity KW - circadian clock KW - damped-oscillator-model of photoperiodic clock KW - diapause KW - Drosophila KW - hour-glass KW - pitcher-plant mosquito KW - bug riptortus-pedestris KW - Nanda-Hamner KW - photoperiodism Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204278 VL - 41 IS - 4 ER -