mass of 15m leads to a y coefficient of approximately 0.01 cal/mole deg^ and to an electronic entropy change of 1.50 cal/mole deg. The y value is much larger than for usual metals and is of the same order of magnitude as the values found in V-doped TigOg/* Ti-doped VgOg,^^ and other vanadium oxides.^^ This result might be characteristic of a highly correlated electron gas for the metallic phase.^^ For the 150-K transition, as the total entropy change is 3.40 cal/mole deg, the electronic contribution to the transition seems to be of the same order of magnitude as the lattice contribution. Therefore, the electronphonon interactions are likely to play an important part in the 150-K transition, although the electron correlations in the 3d band of the metallic phase are not taken into account in this interpretation. Further work is in progress and will be published later.We wish to thank F. De Bergevin for his help in calculating the entropy of the 130-K transition. We are also grateful to B. K. Chakraverty and D. B. McWhan for helpful discussions, to R. Lagnier for the low-temperature specif ic-heat measurements, and to M. Alario and E. L. Evans for the electron microscope studies. Phys. Rev. B 7^, 326 (1973). The Debye temperatures calculated from the coefficients of the T^ law given in this paper are 410, 496, and 591 K for V4O7, V2O3, and VO2, respectively. Zilrich, SwitzerlandWe have measured the resistivity of single-crystal paramagnetic Tb^^Y^.^^Sb with jc = 0, 0.05,0.20,0.40. At low temperatures a resistance anomaly develops in proportion to x, The observed resistance anomaly reflects the temperature-dependent probability that the conduction electrons are scattered from the crystal-field-split 4/ levels of the Tb ions by elastic as well as inelastic processes. A calculation of this anomaly yields excellent agreement for those values of x for which indirect exchange can be neglected.In the last few years there has been an increasing interest in the crystal-field splitting of the 4/ electronic level of the rare earth ions and its many profound effects/ If the ion is of the non-Kramers type (J integral), the crystal-fieldonly ground state may be a singlet. In such a 1321

Bei 2062,1 A.-E. wird eine Absorptionslinie des Jodatoms gefunden, was durch Verbreiterung der sehr scharfen Linie mittels Argon erleichtert wird. Ferner wird ein bei hoherer Temperatur erscheinendes Absorptionsbandenspektrum des Sauerstoffs autgelost erhalten. Es wurde von etwa 1930 A.-E. an (Absorption schon bei Zimmertemperatur) bis tiber 2210 A.-E. hinaus photographiert, indem es bei bis 1050°fortschreitender Erhitzung ilberall intensiver wnrde und sich bis zu immer langeren Wellen verfolgen lieJl. Das Entwirren der Spektren der Nichtmetaile wiirde durch Auffindung ihrer Absorptionsserien sehr erleichtert, doch gelingt diese nicht so leicht wie bei den Metallen. Z. B. miissen die Halogene erst in Atome dissoziiert werden, Beim Aufsuchen der ersten Absorptionslinie des Jods besteht ferner die Schwierigkeit, daf in dem betreffenden Spektralgebiet das Jod starke allgemeine bzw. Bandenabsorption hat, welche eine einzelne Absorptionslinie vollig verdecken wtirde, auch entgeht die letztere wegen ihrer geringen Breite leicht der Beobachtung, denn Spektroskope hochsten Auflosungsvermogens stehen im Ultraviolett bei etwa :2000 A.-E. kaum zur Verftigung. SchlieLllich besitzt die Luft in diesem Gebiet ein vom Sauerstoff herrtihrendes Absorptionsspektrum, d as erst bei Erhitzung etwa von 500°an e r s c.hein t ') und bei den zur Dissoziation des Jods notigen Temperaturen die Beobachtung erschwert. Diese Linien bzw. Banden verfolgten wir von etwa 2210 A.-E. an bis 1830 A.E.Nach dem kurzwelligeu Ende waren sie offenbar nur durch unsere Apparatur begrenzt. In Fig. 2 zeigt das Spektrum e ein kleines Stuck dieser Sauerstoffbanden, aufgenommen bei 1050°. Mit Riicksicht auf dieses Luft-Absorptionsspektrum muJ.lte bei der Erhitzung des J odrohres dafUr gesorgt werden, daf nicht vor und hinter der Rohre merkliche Luftstrecken mit erhitzt wurden. Nach Berticksichtigung ailer dieser Umstande fanden wir im hocherhitzten Joddampf eine Absorptionslinie bei 2062,1 A..-E. Darans berechnet sich eine Anregungsspannung von 5,98 Volt. 1) In einer weiteren Arbeit soll ausfiihrlicher tiber dieses Absorptionsspektrum berichtet werden. Uber eine lichtelektrische Messung der nichtauigelosten Absorption vgl. v. Wartenberg, Phys. ZS. 11, 1168, 1910.

Purpose: The Faroe Islands are home to 50,000 genetically isolated people in the North Atlantic. The prevalence of open-angle glaucoma (OAG) in the Faroese population is unknown. Consequently, we conducted a survey to determine the prevalence of OAG in the Faroese population. We also investigated the role of known glaucoma-causing genes in Faroese OAG. Materials and Methods:We conducted a prospective survey of known and newly diagnosed glaucoma patients at the Faroese National Hospital, Landssjukrahusid, Tórshavn between October 1, 2015 to December 31, 2017. In addition we reviewed the only eye care provider in the Faroese Islands by scrutinizing electronic medical records between 2009 and June 15, 2014, October 1, 2015 and the partly overlapping prescriptions for ocular hypotensive medications in 2016 to identify patients with either a diagnosis of glaucoma, a diagnosis of ocular hypertension or a prescription for ocular hypotensive medications. Next, we prospectively confirmed diagnoses with complete eye examinations. Patient DNA samples were tested for variations in known glaucoma-causing genes [myocilin (MYOC), optineurin (OPTN), and TANK binding kinase 1 (TBK1)]. Results:We determined the age-related prevalence of OAG January 1, 2017 in individuals 40 years or older to be 10.7/1000 (1.07%) and highly age-related. A diagnosis of OAG was present in 264 patients, of whom 211 (79.9%) had primary OAG (including normal tension glaucoma), 49 (18.6%) had pseudoexfoliation glaucoma, and 4 (1.5%) had pigmentary glaucoma. Among patients receiving medications for glaucoma, nearly 50% had primary OAG, while the majority of the rest had ocular hypertension or secondary glaucoma. No disease-causing variants were detected in MYOC, OPTN, or TBK1. Conclusions:The calculated prevalence of OAG in the Faroe Islands was 1.07%. The absence of MYOC, OPTN, or TBK1 diseasecausing variants in Faroese primary OAG patients suggests that a different, potentially unique set of genes may be contributing to the pathogenesis of glaucoma in this population.

Purpose To describe the finding of bright hyperautofluorescent streaks in the peripheral retina in tuberous sclerosis. Observations A woman with a pathogenic TSC1 mutation and cutaneous manifestations of tuberous sclerosis underwent fundus examination and was found to have a cluster of thin, yellowish streaks in the inferior peripheral fundus of her left eye. The streaks were hyperautofluorescent in blue light and associated with irregular thickening of the photoreceptor-pigment epithelium complex on optical coherence tomography. Conclusions and importance The cluster of outer retinal abnormalities in a sector of the peripheral retina in one eye of a TSC1 patient has features in common with the more centrally located and less numerous lesions called achromatic patches. The resemblance of the streak pattern with the pattern of hypoautofluorescence in X-linked retinopathies suggests that the streaks may represent a clone of cells derived from a single somatic mutation in TSC1. The identification of this lesion type expands the scope of conditions that can be diagnosed by fundus imaging.