Microarray Analysis of Late Response to Boron Toxicity in Barley (Hordeum vulgare L.) Leaves

DNA microarrays, being high-density and high-throughput, allow quantitative analyses of thousands of genes and their expression patterns in parallel. In this study, Barley1 GereChip was used to investigate transcriptome changes associated with boron (B) toxicity in a sensitive barley cultivar (Hordeum vulgare L. cv. Hamidye). Eight-day-old aseptically grown seedlings were subjected to 5 or 10 mM boric acid (B(OH)(3)) treatments for 5 days and expression profiles were determined with DNA microarrays using total RNA from leaf tissues. Among the 22,840 transcripts - each represented with a probe set on the GeneChip - 19,424 probe sets showed intensity values greater than 20(th) percentile in at least one of the hybridizations. Compared to control (10 mu M B(OH)(3)), 5 mM B(OH)(3) treatment resulted in differential expression of 168 genes at least by twofold. Moreover, 10 mM B(OH)(3) treatment resulted in at least twofold induction or reduction in expression of 312 transcripts. Among these genes, 37 and 61 exhibited significantly (P <0.05) altered levels of expression under 5 and 10 mM B(OH)(3) treatments, respectively. Differentially expressed genes were characterized using expression-based clustering and HarvEST:Barley. Investigations of expression profiles revealed that B toxicity results in global changes in the barley transcriptome and networks of signaling or molecular responses. A noticeable feature of response to 8 was that it is highly interconnected with responses to various environmental stresses. Additionally, induction of jasmonic acid related genes was found to be an important late response to B toxicity. Determination of responsive genes will shed light on successive studies aiming to elucidate molecular mechanism of B toxicity or tolerance. To the best of our knowledge, this is the first report on global expression analysis of barley seedlings under B toxicity

Anatomy of a microearthquake sequence on an active normal fault

The analysis of similar earthquakes, such as events in a seismic sequence, is an effective tool with which to monitor and study source processes and to understand the mechanical and dynamic states of active fault systems. We are observing seismicity that is primarily concentrated in very limited regions along the 1980 Irpinia earthquake fault zone in Southern Italy, which is a complex system characterised by extensional stress regime. These zones of weakness produce repeated earthquakes and swarm-like microearthquake sequences, which are concentrated in a few specific zones of the fault system. In this study, we focused on a sequence that occurred along the main fault segment of the 1980 Irpinia earthquake to understand its characteristics and its relation to the loading-unloading mechanisms of the fault system

Scattering and anelastic attenuation of seismic energy in the vicinity of north anatolian fault zone, eastern Turkey

Erzincan basin, eastern Turkey, is seismically very active pull-apart basin and developed in between the eastern segments of the north anatolian fault zone. A study of the regional and site attenuation of seismic waves of earthquakes in this area will contribute in predicting earthquake generated ground-motion and becomes vital in making decisions for earthquake regulations and building codes, especially for the cities on the north anatolian fault zone

Energy Conservation Opportunity in Boiler Systems

In this study, “energy efficiency” study has been performed for a natural gas fuelled boiler, operating at 42,000 kPa pressure and 713.15 K temperature, with a nominal capacity of 33.33 kg/s steam. Within this frame, temperature, pressure, velocity, and gas analysis measurements have been made, and energy, mass balances, and exergy analysis have been formed. Then, the efficiency of boiler, potential energy saving options and savings quantities, investment costs, and payback period for normal operating conditions have been calculated from the energy and mass balances. Implementation cost is required only for reducing air leakages in the rotary type air heater and surface thermal losses. The investment cost for reducing air leakage in the rotary type air heater to the acceptable limits (10%) is 600,000 USD. Under these circumstances, the payback period of this investment cost is about fifteen months.</jats:p

Frequency-dependent attenuation of S and coda waves in Erzincan region (Turkey)

The attenuation structure of the Erzincan region is studied using the single scattering model of the coda wave generation and coda normalization method for S waves. We have determined the seismic quality factors Q(s)(f) (for S waves) and Q(c)(f) (for coda waves) as a function of frequency for the frequency range 1.5-24 Hz. The quality factors were derived for 161 seismograms that were registered in a 7-day period after the 13 March 1992 Erzincan earthquake (M(s) = 6.8). Digital recordings from six stations at epicentral distances ranging from 5 to 40 km were used, Frequency-dependent attenuation of s waves according to Q(s)(f) = Q(o)fn in the crust beneath Erzincan was obtained as Q(s)(f) = 35f(0.83) by analysing seismograms of 161 local earthquakes which were selected on the basis of good signal to noise ratios, Coda Q values were calculated from the amplitude decay rate of the S-wave coda in seven frequency bands from 1.5 to 24 Hz. In order to investigate a possible lapse time dependence of the estimated coda Q, we have carried out the analysis of each seismogram using four coda lengths which correspond to four different lapse times 20, 30, 40, 50 s measured from the origin time of the earthquake, Q(c) averages about 46 and 766 at 1.5 Hz and 24 Hz, respectively, at 20 s lapse time and has a frequency dependence of the form Q(c) = 29f(1.03), For large lapse time data, t(c) = 50 s, Q(c)(f) was found to vary from 84 at 1.5 Hz to 783 at 24 Hz with the degree of the frequency dependence, n = 0.81

Site attenuation and source parameters on the North Anatolian Fault zone, eastern Turkey estimated from the aftershocks of 13 March 1992 Erzincan earthquake

Site attenuation and source characteristics of 45 aftershocks of the 13 March 1992 Erzincan, eastern Turkey earthquake have been determined from SH-wave spectra using a least-squares best-fit method. Although the most of the seismograms were recorded on the ophiolitic rock sites and the average regional attenuation correction of Q(s)(f) = 35 f(0.83) was applied, the high fall-off rates gamma ranging between 3.0 and 4.5 beyond the corner frequencies of 8-13 Hz were observed on the SH spectra. The site attenuation value, kappa, has been calculated from the slope of the high frequency part of the SH spectra. It was found that kappa varied in the range of 0.0124-0.0364 s and the average was 0.0246 s with a standard deviation of 0.0047 s. The high fall-off rates of observed spectra have decreased considerably as a result of site attenuation corrections and converged to an average value of 2.3. We concluded that the high fall-off rates of SH wave spectra are mainly controlled by highly deformed Miocene ophiolitic formations which covers a wide area in the North Anatolian Fault zone in the vicinity of Erzincan region. Using the spectra that were corrected for regional and site attenuation, and assuming a Brune's source model; seismic moment, source radius, and stress-drops of the aftershocks were computed. We found that stress-drops for some of the aftershocks in Erzincan area have slightly decreased after removal of site attenuation over SH wave observed spectra