455 research outputs found
Recommended from our members
Boron content of Lake Ulubat sediment: A key to interpret the morphological history of NW Anatolia, Turkey
Freshwater Lake Ulubat (c. 1.5 m deep and c. 138 km2) receives sediment from a 10.414 km2 area in the seismically active Susurluk Drainage Basin (SDB) of NW Turkey. The B and trace element contents of the lake infill seem to be a link between the fresh landforms of the SDB and the lacustrine sediment. Deposition in Lake Ulubat has been 1.60 cm.a-1 for the last 50 a according to radionucleides; however the sedimentation rate over the last millennium was 0.37 cm.a-1 based on 14C dating. The B content of the lacustrine infill displays a slight increase at 0.50 m and a drastic increase at 4 m depth occurring c. 31 a and c. 1070 a ago respectively. Probably the topmost change corresponds to the start of open mining in the SDB and the second one to the natural trenching of borate ore-deposits. These dates also show indirectly a 1.4 cm.a-1 erosion rate during the last millennium as the borate beds were trenched up to 15 m. By extrapolation, it is possible to establish that the formation of some of the present morphological features of the southern Marmara region, especially river incision, began in the late Pleistocene, and developed especially over the last 75 ka
Recommended from our members
Wind control on the accumulation of heavy metals in sediment of Lake Ulubat, Anatolia, Turkey
Freshwater Lake Ulubat (zmean = 1.5-2.0 m and Area = ~138 km2), NW Anatolia, Turkey was filled in by fine-to-medium-grain silts during the late Holocene. Deposition in Lake Ulubat has been 1.6 cm yr-1 for the last 50 years, but the sedimentation rate over the last ~1,600 years was lower (0.37 mm yr-1). The organic matter and carbonate contents of the infill show cyclic changes that reflect environmental fluctuations. The silt-dominated lithology and the vertically uniform heavy metal distributions are probably due to wind-controlled sedimentation in the lake. Heterogeneous mud, derived from a large, mountainous drainage basin, is deposited in the lake mostly during summer, June to October, when conditions are hot and calm. Winter months are stormier and sediments are re-suspended due to the shallow water depth and the effect of waves on the lake bottom. It is likely that re-suspended sediments, particularly fine-grained particles, together with the heavy metals, are transported out of the lake via the outlet, especially during periods of high lake level. This resuspension and removal process probably caused the lake sediments to become silt-dominated and depleted in heavy metals. The role of broad shallow lakes in sequestering sediments and heavy metals can be described more accurately when wind data are considered. Such information may also be helpful for land-use planning in downstream areas
On three dimensional coupled bosons
This is a new version of the paper, which uses the same methods as in the
previous version, but the model is now different. We study two complex scalar
fields coupled through a quadratic interaction in 2+1 dimensions. We use the
method of bilinears as suggested by Rajeev. The resulting classical theory is
studied within the linear approximation and we show that there is a possible
bound state for the composite type particles for a range of coupling constant
strengths.Comment: 12 pages, to appear in JM
Effect of micronized zeolite addition to lamb concentrate feeds on growth performance and some blood chemistry and metabolites
This study was conducted to determine the effects of the addition of micronized zeolite (MZ) on the fattening performance, blood parameters, faecal ash and nitrogen levels of lambs fed concentrate feeds intensively. For two months 25 four-month-old Merino x Ile de France crossbred male lambs (21.1 ± 1.32 kg live weight) were fed 100 g alfalfa hay and a mixed concentrate diet containing 0%, 1%, 2% or 3% additional MZ. At the end of the study, bodyweight gain and feed consumption were not affected by the treatments. Similarly, the addition of up to 2% MZ to the diet did not affect slaughter weight, hot carcass or cold carcass weights, but they decreased at 3% MZ inclusion. No differences were observed between the groups in terms of blood urea nitrogen, plasma glucose, serum creatinine, triglyceride, sodium, potassium and chlorine concentration. However, serum total protein, calcium and phosphorus concentrations were affected by MZ supplementation. The addition of MZ to the ration did not affect the faecal dry matter content and total nitrogen level, yet it increased the ash content of the faeces. Consequently, it was demonstrated that the addition of up to 2% MZ to lamb grower feed does not have a negative impact on performance and carcass yield of the animals, but affects serum total protein, calcium and phosphorus concentrations
Investigating of Mechanical Properties of Mortars Based on Fly Ash and Blast Furnace Slag Activated with Alkali
Alkali activated mortars obtained from granulated blast furnace slag and fly ash were used instead of Portland cement by activating with alkali. Sodium silicate and sodium hydroxide were activated blast furnace slag and fly ash. Mortar samples were prepared 40x40x160 mm as prismatic samples according to TS EN 196-1 and they were cured at room temperature. Compressive and flexural strength of the mortar samples including blast furnace slag and fly ash were investigated by experimenting
Esterase variation in Turkish white-toothed shrews (Crocidura): Record of a trimeric esterase
This study focuses on esterase variation of the genus Crocidura in Turkey. A total of 248 white-toothed shrews were analyzed by means of cellulose acetate gel electrophoresis. Liver tissue and alfa naphthyl acetate were used to investigate esterase variation in Turkish white-toothed shrews. A different esterase banding pattern was found in one Crocidura individual. This phenotype had four anodally migrated bands on cellulose acetate gel. The Crocidura individual displaying the given phenotype was identified as Crocidura suaveolens. The different esterase banding pattern observed in this study is considered to be a result of the trimeric structure of esterase in the lesser white-toothed shrew (Crocidura suaveolens)
Large N limit of SO(N) scalar gauge theory
In this paper we study the large limit of SO(N_c) gauge theory coupled
to a real scalar field following ideas of Rajeev. We see that the phase space
of this resulting classical theory is Sp_1(H)/U(H_+) which is the analog of the
Siegel disc in infinite dimensions. The linearized equations of motion give us
a version of the well-known 't Hooft equation of two dimensional QCD.Comment: 16 pages, no figure
Contribution of heme oxygenase 2 to blood pressure regulation in response to swimming exercise and detraining in spontaneously hypertensive rats
Background: We aimed to determine the effects of exercise followed by detraining on systolic blood pressure (SBP), heme oxygenase 2 (HO-2) expression, and carboxyhemoglobin (COHb) concentration in spontaneously hypertensive rats (SHR) to explain the role of carbon monoxide (CO) in this process. Material/Methods: Animals were randomized into exercised and detrained groups. Corresponding sedentary rats were grouped as Time 1–2. Swimming of 60 min/5 days/week for 10 weeks was applied. Detraining rats discontinued training for an additional 5 weeks. Gene and protein expressions were determined by real-time PCR and immunohistochemistry. Results: Aorta HO-2 histological scores (HSCORE) of hypertensive rats were lower, while SBP was higher. Swimming caused enhancement of HO-2 immunostaining in aorta endothelium and adventitia of SHR. Exercise induced elevation of blood COHb index in SHR. Synchronous BP lowering effect of exercise was observed. HO-2 mRNA expression, HSCORE, and blood COHb index were unaltered during detraining, while SBP was still low in SHR. Conclusions: CO synthesized by HO-2 at least partly plays a role in SBP regulation in the SHR-and BP-lowering effect of exercise. Regular exercise with short-term pauses may be advised to both hypertensives and individuals who are at risk. © Med Sci Monit
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
Large N limit of SO(N) gauge theory of fermions and bosons
In this paper we study the large N_c limit of SO(N_c) gauge theory coupled to
a Majorana field and a real scalar field in 1+1 dimensions extending ideas of
Rajeev. We show that the phase space of the resulting classical theory of
bilinears, which are the mesonic operators of this theory, is OSp_1(H|H
)/U(H_+|H_+), where H|H refers to the underlying complex graded space of
combined one-particle states of fermions and bosons and H_+|H_+ corresponds to
the positive frequency subspace. In the begining to simplify our presentation
we discuss in detail the case with Majorana fermions only (the purely bosonic
case is treated in our earlier work). In the Majorana fermion case the phase
space is given by O_1(H)/U(H_+), where H refers to the complex one-particle
states and H_+ to its positive frequency subspace. The meson spectrum in the
linear approximation again obeys a variant of the 't Hooft equation. The linear
approximation to the boson/fermion coupled case brings an additonal bound state
equation for mesons, which consists of one fermion and one boson, again of the
same form as the well-known 't Hooft equation.Comment: 27 pages, no figure
- …