Evaluation of Intraocular Pressure (IOP) Regarding Circadian Rhythm, Age, Sex and Eye Side in Awassi Sheep

Measurement of intraocular pressure (IOP) in domestic animals has become a part of routine eye examination with advent of applanation tonometer. Delayed control of high IOP may lead to permanent blindness due to retinal ganglion cells dysfunction and optic nerve degeneration. This study aimed at evaluating IOP of Awassi sheep with respect to circadian rhythm, age, sex and eye sides and finally to establish a reference (baseline, normal) IOP value for this particular species. A total of 24 healthy sheep with different ages and sexes were used. The animals were divided into 2 equal groups, = 1 (6 male, 6 female, n = 12) years old. IOP measurements were performed twice, in the morning (6:00 a.m.) and in the evening (8:00 p.m.) with Tono-pen Vet (R) applanation tonometer. Mean LOP in the animals decreased from 16.21 mmHg in the morning to 12.65 mmHg in the evening with an approximately rate of 22% (P = 1 (n=48) showed no difference (P >0.05). The reference IOP for this animal was calculated as 14.43 +/- 2.72 mmHg notwithstanding any variable. It was concluded that in this breed IOP values can vary significantly as far as circadian rhythm is concerned and Tono-pen Vet (R) can be used for sheep IOP measurement as an alternative to other applanation tonometry

Analyses of Sulfur and Iron in Waterlogged Archaeological Wood: The Case of Polyethylene-Glycol-Treated Yenikapı 12 Shipwreck

The Yenikapı (YK) 12 shipwreck is 1 of 37 shipwrecks found at Yenikapı, Istanbul. This merchantman has been dated to AD 672–876 by radiocarbon analyses. The conservation of YK 12, which was assembled with iron nails, was completed with the pre-impregnation of polyethylene glycol (PEG) and using vacuum freeze-drying processes. However, after conservation, dust formation was observed on some wooden parts of the shipwreck during storage. In this study, iron–sulfur-related problems detected in the woods of YK 12 were evaluated. We analysed samples taken from YK 12 to study the sulfur and iron content in woods from oak (Quercus), walnut (Juglans), and hornbeam (Carpinus), representing taxa with different wood properties. Fourier-transform infrared spectroscopy (FTIR) analyses, X-ray diffraction (XRD), and pH measurements were conducted on five samples. The results of these studies showed that the dust consisted of wood particles, PEG, and hydrated iron sulfates, such as FeSO4·4H2O and FeSO4·7H2O. Additionally, one sample included SiO2, whilst another exhibited a low pH value. These findings highlight the importance of optimum ambient conditions for the storage and display of these shipwrecks in order to prevent the irreversible degradation of YK 12 and other recovered shipwrecks

Variation of Fault Creep Along the Overdue Istanbul-Marmara Seismic Gap in NW Türkiye

Strain energy from tectonic loading can be partly released through aseismic creep. Earthquake repeaters, repeatedly activated brittle fault patches surrounded by creep, indicate steady-state creep that affects the amount of seismic energy available for the next large earthquake along a plate contact. The offshore Main Marmara Fault (MMF) of the North Anatolian Fault Zone represents a seismic gap capable of generating a M > 7 earthquake in direct vicinity to the mega-city Istanbul. Based on a newly compiled seismicity catalog, we identify repeating earthquakes to resolve the spatial creep variability along the MMF during a 15-year period. We observe a maximum of seismic repeaters indicating creep along the central and western MMF segments tapering off toward the locked onshore Ganos fault in the west, and the locked offshore Princes Islands segment immediately south of Istanbul in the east. This indicates a high degree of spatial creep variability along the Istanbul-Marmara seismic gap

Book Review

Reviewing Frank E. Cooper, Living the Law, Bobbs-Merrill Company, Inc., 195

Metamict zircon and structural characters: Pütürge metamorphite example

Mineralogical studies (rock named, zircon separate), geochemical analysis(LA-ICPMS) and cathodoluminescence (CL) image were applied to samples of the Pütürge metamorphites representing different facies such as amphibolites and greenschiste. Pütürge metamorphites are made up of pelite/semi-pelite, psammite, metagranite gneisse, schist, amphibolite, marble and quartzite type rocks. Mineral paragenesis, the transformation of the garnet mineral advancing on the kyanite-almandine-muscovite and staurolite-almandine sub-facies of the amphibolite facies of the massive to chlorite and biotite minerals along with the transformation of the kyanite mineral to muscovite mineral show that the massive has undergone two retrograde metamorphisms on the greenschist facies. The exhumation process of the metamorphites is seen as the cause of the retrograde metamorphism. The cathodoluminescence images of zircon minerals show a zoning that indicates a metamorphic growth where partial radiation damage in the shape of oscillatory zoning and porous structure also occurs pointing out the magmatic root. A zircon type with different textural and chemical components which might be called partially metamictte has developed. The luminescence feature in partially radiated zircon particles rich in radiogenetic minerals is rather high in comparison with other zircon particles. High temperature during the metamorphism of the massive and the ratio of the radiogenetic elements like U and Th in the mineral are effective in the textural and chemical difference between the core and rims of zirconsPütürge metamorfitlerinde mineralojik (kayaç adlandırılması, zirkon ayrımı), jeokimyasal (LA-ICPMS) ve Kathödölüminesans (CL) incelemeleri Pütürge metamorfitlerinin amfibolit ve yeşilşist fasiyesi gibi farklı fasiyesleirn özelliğini yansıtacak örneklerden alınmıştır. Pütürge metamorfitleri, pelit/semi-pelit, pisamit, metagranit, gnays, şist, amfibolit, mermer ve kuvarsitten oluşur. Mineral parajenezleri, masifin amfibolit fasiyesinin disten-almandin-muskovit ve stavrolit-almandin alt fasiyeslerinde ilerleyen, granat mineralinin klorit ve biyotit minerallerine dönüşümleri ve disten mineralinin muskovit mineralinine dönüşümü gibi özelliklerden yeşilşist fasiyesinde gerileyen türden iki metamorfizma geçirmiş olduğunu göstermektedir. Gerileyen metamorfizmaya metamorfitlerin yükselme süreci sebep olarak görülmektedir. Zirkon minerallerinin kathödölüminesans görüntülerinde, magmatik kökeni işaret eden ilksel (oscilatory) zonlanma ve gözenekli yapı şeklinde, kısmen radyasyon hasarının da geliştiği büyüme zonlanması görülür. Dokusal ve kimyasal bileşimleri farklı olan, kısmen metamikt diyebileceğimiz zirkon değişimi gelişmiştir. Radyojenetik kapantı minerallerince zengin metamikt zirkon tanelerinde, luminesans özellik diğer zirkon tanelerine nazaran yüksektir. Zirkonda, çekirdek ve kenar kısımları arasındaki dokusal ve kimyasal farklılığa, masifin metamorfizması sırasındaki yüksek sıcaklık ve U, Th gibi radyojenetik elementlerin mineral içerisindeki oranı etkili olmuştur

Tunable adsorption on carbon nanotubes

We investigated the adsorption of a single atom, hydrogen and aluminum, on single wall carbon nanotubes from first-principles. The adsorption is exothermic, and the associated binding energy varies inversely as the radius of the zigzag tube. We found that the adsorption of a single atom and related properties can be modified continuously and reversibly by the external radial deformation. The binding energy on the high curvature site of the deformed tube increases with increasing radial deformation. The effects of curvature and radial deformation depend on the chirality of the tube.Comment: To be appear in Physical Review Letter

The Bounds on the magnetic moment of the tau-neutrino via the process (e+e-)-->nunu(bar)gamma

Bounds on the anamolous magnetic moment of the tau neutrino are calculated through the reaction (e+e-)-->nunu(bar)gamma at the neutral boson pole and in the framework of an extended standard model, a left-right symmetric model and a superstring-inspired model which has one extra low-energy neutral gauge boson. The results are basedComment: 9 pages, 1 figure, 3 Table

Pressure-Induced Interlinking of Carbon Nanotubes

We predict new forms of carbon consisting of one and two dimensional networks of interlinked single wall carbon nanotubes, some of which are energetically more stable than van der Waals packing of the nanotubes on a hexagonal lattice. These interlinked nanotubes are further transformed with higher applied external pressures to more dense and complicated stable structures, in which curvature-induced carbon sp$^{3}$ re-hybridizations are formed. We also discuss the energetics of the bond formation between nanotubes and the electronic properties of these predicted novel structures.Comment: 4 pages, 4 postscript figures; To be appear in PR

Improving the sensitivity of future GW observatories in the 1-10 Hz band: Newtonian and seismic noise

The next generation gravitational wave interferometric detectors will likely be underground detectors to extend the GW detection frequency band to frequencies below the Newtonian noise limit. Newtonian noise originates from the continuous motion of the Earth’s crust driven by human activity, tidal stresses and seismic motion, and from mass density fluctuations in the atmosphere. It is calculated that on Earth’s surface, on a typical day, it will exceed the expected GW signals at frequencies below 10 Hz. The noise will decrease underground by an unknown amount. It is important to investigate and to quantify this expected reduction and its effect on the sensitivity of future detectors, to plan for further improvement strategies. We report about some of these aspects. Analytical models can be used in the simplest scenarios to get a better qualitative and semi-quantitative understanding. As more complete modeling can be done numerically, we will discuss also some results obtained with a finite-element-based modeling tool. The method is verified by comparing its results with the results of analytic calculations for surface detectors. A key point about noise models is their initial parameters and conditions, which require detailed information about seismic motion in a real scenario. We will describe an effort to characterize the seismic activity at the Homestake mine which is currently in progress. This activity is specifically aimed to provide informations and to explore the site as a possible candidate for an underground observatory. Although the only compelling reason to put the interferometer underground is to reduce the Newtonian noise, we expect that the more stable underground environment will have a more general positive impact on the sensitivity.We will end this report with some considerations about seismic and suspension noise

Increased systemic oxidative stress in patients with keratoconus

PurposeTo establish the effect of systemic oxidative stress on the pathogenesis of keratoconus by measuring serum total oxidant status (TOS) and total antioxidant status (TAS) in patients with keratoconus.MethodsTwenty-five patients with keratoconus (keratoconus group) and 25 age-sex-matched healthy subjects (control group) were enrolled in the study. Exclusion criteria were smoking habit, history of any other corneal pathology, systemic disease or inflammation, and current antioxidant or anti-inflammatory therapies. All participants underwent a detailed ophthalmological examination and corneal topography. Serum samples were obtained from all participants. Oxidative stress markers (TAS and TOS) were measured using a commercial kit and oxidative stress index (OSI) was calculated.ResultsThe study comprised 25 patients with keratoconus (mean age of 26.4±1.7 years) and 25 healthy control subjects (mean age of 26.6±1.7 years) (P>0.05). The serum TOS and OSI values were significantly higher in patients with keratoconus compared with those of the controls (P=0.036 and 0.037, respectively). However, serum TAS did not show significant difference between the keratoconus and control groups (P=0.497).ConclusionsThe higher levels of serum oxidant status and OSI in patients with keratoconus suggest that systemic oxidative stress might be involved in the pathogenesis of keratoconus. © 2014 Macmillan Publishers Limited