Seasonal Changes of Soil Organic Carbon and Microbial Biomass Carbon in Different Forest Ecosystems

Soil organic carbon (SOC) and microbial biomass carbon (MBC) are important components of soil organic matter (SOM). SOC and MBC have generally recognized key parameters of soil quality and health, and also they have been linked to forest ecosystem productivity, using as a sensitive indicator for ecosystem monitoring programs. Both of them play a crucial role in the carbon cycle and influence many environmental, biological, and chemical factors. Soil organic matter decomposition by soil microorganisms contributes to the nutrient availability and release in an ecosystem. This interaction between SOM and MBC is managed in soil aggregation, soil porosity, moisture content, and aeration. Forest soils can store more carbon than other land uses because they contain a wide variety of soil microorganisms. Enhancing these two important components of soil can contribute to climate change mitigation and adaptation strategies. In this chapter, an overview of the understanding of the most important soil quality and health factors managed soil C in forest soils and provided how seasonal changes affect soil organic carbon and microbial biomass carbon

AISI 2507 Süper Dubleks Paslanmaz Çeliğinin Hibrit Soğutma/Yağlama Yöntemleri Altında Tornalanmasında Yüzey Kalitesinin İncelenmesi

Son yıllarda ekolojik soğutma/yağlama yöntemleri sürdürülebilir imalat için metal işleme operasyonlarında kullanılmaya başlanmıştır. Bu yöntemlerin başında ise birbirine göre üstün özelliklerin bir araya getirildiği hibrit soğutma/yağlama yöntemlerinin kullanıldığı çalışmalar ön plana çıkmaktadır. Bu çalışmada; AISI 2507 dubleks paslanmaz çeliğinin Minimum Miktarda Yağlama (MMY), kriyojenik soğutma (Kry) ve hibrit (Kry+MMY) soğutma/yağlama koşulları altında tornalanmasında, yüzey kalitesi incelenmiştir. İşlenen yüzeylerin kalitesinin belirlenmesinde yüzey pürüzlülük (Ra), iki boyutlu yüzey görüntüleri ve üç boyutlu yüzey topografyaları kullanılmıştır. Deneyler üç farklı soğutma/yağlama koşulunda (MMY, Kry ve Kry+MMY), kesme hızında (80, 120 ve 160 m/dak) ve ilerlemede (0,16-0,20 ve 0,24 mm/dev) gerçekleştirilmiştir. Deney tasarımında ve optimum koşulların belirlenmesinde Taguchi L27 tasarımı kullanılmıştır. Deneysel sonuçlara etki eden faktörler ve faktörlerin etki oranlarını belirlemek için varyans analizi (ANOVA) kullanılmıştır. Deney sonuçlarına göre yüzey kalitesi için optimum koşullar, Kry+MMY hibrit soğutma/yağlama koşulu, 160 m/dak kesme hızı ve 0,16 mm/dev ilerleme olarak belirlenmiştir. En iyi Ra değeri (1,151 µm) A3, B3, C1 koşulunda, en kötü Ra değeri ise (-2,861 µm) A2, B1, C3 koşulunda elde edilmiştir

POTENTIAL PROTECTIVE ROLE OF SDF-1 AND CXCR4 GENE VARIANTS IN THE DEVELOPMENT OF DEMENTIA

Background: The aim of this study was to evaluate the role of polymorphisms of stromal cell-derived factor-1 (SDF-1) and chemokine receptor-4 (CXCR4) genes in dementia susceptibility in a Turkish population. Subjects and methods: The study group included 61 dementia patients, while the control group comprised 82 healthy individuals. Gene polymorphisms of SDF-1 3’A G801A (rs1801157) and CXCR4 C138T (rs2228014) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Results: A significantly reduced risk for developing dementia was found for the group bearing an A allele for SDF-1 3’A polymorphism (p=0.009; x2=6.812; OR=0.626; 95%CI= 0.429-0.913). The frequency of the CXCR4 TT and TC genotype was significantly lower in patients with dementia compared to controls (p=0.028; x2=5.583; OR=0.215; 95%CI=0.05-0.914); (p=0.027; x2=4.919; OR=0.484; 95% CI= 0.246-0.955). Additionally, combined genotype analysis showed that the frequency of SDF1 GACXCR4 CC was significantly lower in patients with dementia in comparison with those of controls (p=0.049; OR=0.560; 95% CI= 0.307±1.020). Conclusions: Our study provides new evidence that SDF1 A and CXCR4 T alleles may be associated with a decreased dementia risk. The present study is important because to our knowledge, it is the first one to be conducted in a Turkish population to date, but we believe that more patients and controls are needed to obtain statistically significant results

Peptide-directed co-assembly of nanoprobes on multimaterial patterned solid surfaces

This is the published version. Copyright 2012 Royal Society of ChemistryBiocombinatorially selected solid-binding peptides, through their unique material affinity and selectivity, are a promising platform for building up complex hierarchical assemblies of nanoscale materials and molecular probes, targeted to specific practical solid surfaces. Here, we demonstrate the material-specific characteristics of engineered gold-binding and silica-binding peptides through co-assembly onto micro- and nano-patterned gold surfaces on silica substrates. To build hierarchical nanostructures on patterned solid surfaces, we utilize peptides as molecular tools and monitor their behavior by either conjugating biotin to them for specific affinity to streptavidin-coated QDot nanoparticles or labelling them with small fluorescent labels. This biomimetic peptide-based approach could be used as an alternative to conventional chemical coupling and surface functionalization techniques with substantial advantages, allowing simultaneous assembly of two or more inorganic nano-entities and/or molecular probes onto patterned inorganic solid substrates. The results have significant implications in a wide range of potential applications, including controlled assembly of hybrid nanostructures in bionanophotonic and biosensing devices

Genome of Wild Olive and the Evolution of Oil Biosynthesis

Here we present the genome sequence and annotation of the wild olive tree (Olea europaea var. sylvestris), called oleaster, which is considered an ancestor of cultivated olive trees. More than 50,000 protein-coding genes were predicted, a majority of which could be anchored to 23 pseudochromosomes obtained through a newly constructed genetic map. The oleaster genome contains signatures of two Oleaceae lineage-specific paleopolyploidy events, dated at similar to 28 and similar to 59 Mya. These events contributed to the expansion and neo-functionalization of genes and gene families that play important roles in oil biosynthesis. The functional divergence of oil biosynthesis pathway genes, such as FAD2, SACPD, EAR, and ACPTE, following duplication, has been responsible for the differential accumulation of oleic and linoleic acids produced in olive compared with sesame, a closely related oil crop. Duplicated oleaster FAD2 genes are regulated by an siRNA derived from a transposable element-rich region, leading to suppressed levels of FAD2 gene expression. Additionally, neofunctionalization of members of the SACPD gene family has led to increased expression of SACPD2,3, 5, and 7, consequently resulting in an increased desaturation of steric acid. Taken together, decreased FAD2 expression and increased SACPD expression likely explain the accumulation of exceptionally high levels of oleic acid in olive. The oleaster genome thus provides important insights into the evolution of oil biosynthesis and will be a valuable resource for oil crop genomics

Edwardsiellosis in freshwater angelfish (Pterophyllum scalare)

The freshwater angelfish (Pterophyllum scalare) with its many varieties is one of the most popular species in the ornamental market. The moribund freshwater angelfish individuals (20-25 g in weight) were sampled from an ornamental fish production facility to determine the cause of mortalities started immediately in fish without any other visible finding except the loss of appetite. The mortality rate in the population was as high as 50% within a week. Bacteriological samples were taken from internal organs for the identification of the causative agent. Hemorrhage in the eyes, loss of scales and skin depigmentation were the most obvious external finding in the moribund fish. Internally; the liver was pale, the spleen was enlarged and the intestinal walls were thinned. According to conventional biochemical and physiological tests and 16S rRNA gene sequencing, all isolated bacteria were identified as Edwardsiella tarda. The antimicrobial susceptibility test performed using the disk diffusion test showed that the E. tarda strains we obtained were sensitive to enrofloxacin, sulfamethoxazole with trimethoprim, furazolidone and flumequine but resistant to ampicillin and tetracycline antibiotics

Edwardsiellosis in freshwater angelfish (Pterophyllum scalare)

The freshwater angelfish (Pterophyllum scalare) with its many varieties is one of the most popular species in the ornamental market. The moribund freshwater angelfish individuals (20-25 g in weight) were sampled from an ornamental fish production facility to determine the cause of mortalities started immediately in fish without any other visible finding except the loss of appetite. The mortality rate in the population was as high as 50% within a week. Bacteriological samples were taken from internal organs for the identification of the causative agent. Hemorrhage in the eyes, loss of scales and skin depigmentation were the most obvious external finding in the moribund fish. Internally; the liver was pale, the spleen was enlarged and the intestinal walls were thinned. According to conventional biochemical and physiological tests and 16S rRNA gene sequencing, all isolated bacteria were identified as Edwardsiella tarda. The antimicrobial susceptibility test performed using the disk diffusion test showed that the E. tarda strains we obtained were sensitive to enrofloxacin, sulfamethoxazole with trimethoprim, furazolidone and flumequine but resistant to ampicillin and tetracycline antibiotics

Imaging visco-elastic properties of soft tissue with ultrasound

This thesis describes a system to measure the mechanical properties of soft tissue. The mechanical properties depend on the type of tissue (e.g. fat, muscle, blood) and the presence of disease or pathology. For example, it has been known that many cancers, such as carcinoma of the breast and the prostate, appear as hard nodules. Manual palpation is widely used for detecting these nodules but detection by palpation is restricted to large tumors that reside relatively close to an accessible surface. Current imaging devices such as computed tomography, magnetic resonance imaging and ultrasound are not directly capable of measuring the mechanical properties of tissue. An emerging research topic, called elastography, aims to produce a new type of image that depicts mechanical properties of tissue. The basic principle is to excite motion in a tissue, record the motion with an imaging device, and then estimate the mechanical properties from the recorded data. This thesis presents a new approach based on this principle where a computer-controlled vibrator induces motion over a range of frequencies simultaneously and the resulting displacement is recorded at multiple locations and time instants with a sequence of ultrasound images. Two methods are proposed for estimating mechanical properties such as stiffness, damping, and mass, from the recorded data. In the first method, the tissue is modeled by using mass elements at different locations connected to each other by springs and dampers. These elements represent the local mass, stiffness, and damping of the tissue. The equation of motion for the proposed one dimensional model is solved to extract these parameters. The second method performs a transfer function analysis of the tissue motion. According to this method, the tissue dynamics between two locations along the axis of motion is considered as a linear dynamic system. The transfer function between the two locations is obtained by spectral analysis with the recorded motion used as inputs and outputs. The shape of the transfer function can then be analyzed further. For example, the stiffness of tissue can be estimated from the magnitudes of the transfer function at low-frequencies. Common to both methods is a new time domain correlation-based tracking algorithm for measuring tissue motion in successive ultrasound images. The algorithm is based on stretching the time domain ultrasound signals according to the local compression applied along the axial direction. The accuracy of the new method is demonstrated to be higher than the standard time domain correlation-based algorithms on a small number of tests on tissue mimicking materials. Both simulations and experiments have been performed to validate the proposed methods. Simulations show that the parameters can be extracted within 1 % error when the measurement noise level is set to 0 %, for one dimensional mass-spring-damper models with varying parameters. The simulations are repeated by taking ultrasonic noise and correlation-based motion tracking noise into account. The errors in damping and stiffness values are within 5 % at 4 mm resolution, and 12 % at 6 mm resolution for mass values, for a simulated one dimensional homogeneous tissue. Initial experimental results from homogeneous and layered tissue mimics are reported which demonstrate the ability of both methods to quantitatively image tissue stiffness. Preliminary results on tissue damping distribution for homogeneous tissue mimics are found to be comparable to the reported damping values for the same type of material in the literature. The shear viscosity values are found to be between 12.5-19.7 Pa-s for a gelatin block with a Young's modulus of 25 kPa . Extraction of mass is still under investigation. Both the simulations and the experimental results show that the new methods are feasible and further investigation is needed to continue development of the ideas.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

Bayes tabanlı çoklu çerçeveli süper çözünürlük.

This thesis aims at increasing the effective resolution of an image using a set of low resolution images. This process is referred to as super resolution (SR) image reconstruction in the literature. This work proposes maximum a-posteriori (MAP) based iterative reconstruction methods for this problem. The first contribution of the thesis is a novel edge preserving SR image reconstruction method. The proposed MAP based estimator uses local gradient direction and amplitude for optimal noise reduction while preserving edges. The second contribution of the thesis is a novel texture prior for maximum a posteriori (MAP) based super resolution (SR) image reconstruction. The prior is based on a multiscale compound Markov Random Field (MRF) model. Gabor filters are utilized for subband decomposition. Each subband is modeled by a compound MRF that inherits a binary texture process. The texture process at each pixel location at each subband is estimated iteratively along with the unknown high-resolution image pixels. Finally, a two stage SR method comprising a Bayesian reconstruction step followed by a restoration step is proposed. In the first stage, two MAP based SR estimators with different regularizations are employed. In the second stage, pixel-to-pixel difference between these two estimates is post-processed to restore edges and textures while eliminating noise. Experiments on synthetically generated images and real experiments on visual CCD cameras and thermal cameras demonstrate that the proposed methods are more favorable compared to state-of-the-art SR methods especially on textures and edges.Ph.D. - Doctoral Progra