Earlier it was reported by Najdegerami et

Earlier, it was reported by Najdegerami et al. (2012) that PHB significantly increased the linoleic SAR 405 (LA) and total (n-6) FAs content of the liver of Siberian sturgeon fingerling fed a 5gkg−1 PHB diet. In another study, PHB was found to increase the total monounsaturated and total (n-3) FAs content of giant tiger prawn postlarvae (Ludevese-Pascual, personal communication). Similarly, an increasing trend was observed in the total saturated, total monounsaturated FAs and total (n-6) FAs content (% on DW) for the Nile tilapia juveniles fed with PHB in this study. However, PHB did not affect the composition of FAs groups when expressed as % on total lipid content. This indicates that the fish FA profile was not affected by PHB supplementation. The FAME analysis procedure performed in this study only measured the long chain fatty acids (C14–C24) and did not provide information on the composition of SCFAs (C2–C6) or medium chain fatty acids (C8–C12). As the degradation of dietary PHB is hypothesized to results in the release of SCFAs, likely β-HB (De Schryver et al., 2010; Defoirdt et al., 2009), it will be interesting to evaluate the effect of PHB on the fish SCFAs profile in future research.
The gnotobiotic challenge test was used to investigate if PHB has a similar disease protecting effect for fish as it does for crustaceans. In this study, E. ictaluri gly09R, a pathogen known to cause mortality in tilapia culture, was used (Soto et al., 2012). The experiment showed that PHB supplementation to gnotobiotic Nile tilapia larvae provided significant protection against the challenge, although the protection was not complete in comparison to a negative control. These observations are similar to the ones of Thai et al. (2014) in freshwater prawn and Laranja et al. (2014) in giant tiger prawn. While it has been shown that the use of PHB limits the pathogenicity and the presence of presumptive vibrios in shrimp (Defoirdt et al., 2007; Thai et al., 2014), it remains to be determined if PHB also worked through affecting the growth or activity of E. ictalurigly09R in the tilapia or that it may have acted as an immunostimulant as described by Baruah et al. (2015) for brine shrimp. The availability of the gnotobiotic Nile tilapia challenge test creates the opportunity for a detailed investigation of the effects of PHB exposure on pathogen growth and virulence under microbiologically controlled conditions.

Conclusion and perspectives


Porcine reproductive and respiratory syndrome virus (PRRSV) is a single stranded RNA virus of the Arteriviridae family (Meulenberg et al., 1994). This virus is widespread throughout the world and causes disease characterized by abortions and stillbirth, increased pre-weaning mortality and respiratory disorders. PRRSV infections are one of the most significant causes of economic losses in the swine industry (Neumann et al., 2005), not only because of a direct effect of the virus infection, but also because of secondary bacterial infections that exacerbate clinical symptoms in growing pigs (reviewed by Drew, 2000; Gómez-Laguna et al., 2013).
There are two genotypes of PRRSV described, represented by two prototypes: Lelystad virus (European type or genotype I) and VR-2332 (American type or genotype II) (Nelsen et al., 1999). The European type strains can be further divided into at least three subtypes: Pan-European subtype 1, and Eastern European subtypes 2 and 3 (Stadejek et al., 2006, 2008). There are significant antigenic and pathogenic differences between and within genotypes. Within the European genotype, the Eastern European subtype 3 strains are considered to be more virulent, as determined by clinical manifestations in infected pigs under field and experimental conditions (Karniychuk et al., 2010; Morgan et al., 2013; Weesendorp et al., 2013).
After infection with PRRSV, the adaptive immune response is often weak and delayed, resulting in pigs that are not fully protected against re-infection. After re-introduction of a PRRSV strain, or introduction of a new PRRSV strain in a herd, the recovered pigs can become re-infected and excrete virus, which can subsequently infect new pigs. Experimental studies have shown that challenge with homologous or heterologous strains can result in new infections and virus excretion (Díaz et al., 2012; Shibata et al., 2000). As with natural infections, vaccination does not always result in sterile immunity, and vaccinated pigs can excrete virus after vaccination and infection. None of the currently used PRRSV vaccines, that all contain subtype 1 strains, can claim full protection (Diaz et al., 2006; Zuckermann et al., 2007; reviewed by Darwich et al., 2010).

SVC and STATCOM operation during the three phase fault SVC

SVC and STATCOM operation during the three-phase fault.
SVC and STATCOM operation during the three-phase fault.
Figure options
5. Conclusions
This paper focuses on the technical comparison of two of the most currently used FACTS shunt compensators: the SVC and the STATCOM. The advantages and disadvantages between these devices have been presented based on their basic operating characteristics, with the intention of highlighting and comparing the benefits that they SAR 405 can bring to a power system. The basic operation characteristics and the mathematical models have shown that the STATCOM provides better support under faulted conditions, when reactive current is needed. No notable difference is detected in steady state.
The 5-bus system was used in order to illustrate the steady- and dynamic-state performance of both devices in power systems. As expected in the steady state, the magnitude of the voltage remained at the specific value in both cases. In the dynamic analysis when both devices are compared, the system tested is stable for this disturbance only when shunt devices are connected. The STATCOM has a certain advantage over the SVC controller, since the STATCOM acts immediately in the right direction by boosting the voltage during the fault, enabling a lower magnitude in the first-swing and a faster recovery.
The technology of FACTS represents an alternative to control. The design and implementation of a control system more efficient for the governors of the machines and for proper control of SVC and STATCOM controllers to improve their response to contingencies of large magnitude are important topics for further research.
Conflict of interest
The authors have no conflicts of interest to declare.
The authors gratefully acknowledge the support of S. Olvera-Sumano, J. Sosa-Lopez, undergraduate students of the Facultad de Ingeniería, UNAM.
1. Introduction
The mainstay of any digital system, interacting with real world, is Ligation the data acquisition of the signals from various systems. The requirement for data acquisition is to quantify an electrical or physical phenomenon such as voltage, current, temperature, pressure or sound. Though every data acquisition system (DAS) is defined by its application requirements, every system shares a common goal of acquiring, analyzing, and presenting information. DASs blend signals, sensors, actuators, signal conditioning, data acquisition devices and application software (Abdallah and Elkeelany, 2009 ; Marino et al., 2010). Data acquisition involves amassing analog signals from SAR 405 measurement sources and digitizing the signal for storage, analysis, and presentation or control. Generally, sensors provide continuous data about a particular aspect of a process such as voltage, current, temperature and so forth in an analog form which needs to be converted into digital form and also need further processing after acquisition. Consequently, analog signal is converted into digital through analog to digital converter (ADC). The obtained data may now be transmitted on a digital bus to the central processing unit for further analysis. Digital transmission is more immune to noise than analog data from the sensors (Abdallah et al., 2011 ; Siddiqui et al., 2015).

Table Changes in climate factors

Table 1. Changes in climate factors over the sub-regions due to LUCC
Region DTR (°C) Daily maximum temperature (°C) Daily minimum temperature (°C) Latent heat flux (W m–2) Low cloud amount (%) Absorbed solar radiation (W m–2)
North America –0.27 –0.28 –0.01 0.15 1.56 –1.77
South America –0.43 –0.31 0.12 0.92 4.77 –1.92
Eurasia –0.23 –0.25 –0.02 0.15 1.73 –1.40
India –0.18 0.01 0.18 –0.82 –1.96 0.42
East Asia –0.27 –0.37 –0.10 –0.69 –0.60 –1.20
Scatter plots of daily minimum (left) and maximum (middle) air temperature, and…
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Figure 4. Scatter plots of daily minimum (left) and maximum (middle) air temperature, and DTR (right) due to LUCC in North America (upper), East Asia (middle), and India (lower)
4. Discussion and conclusions
Based on numerical experiments with NCAR CAM4.0, potential impacts of LUCC on DTR are investigated in this study. Results show that changes from potential vegetation to current land use yield evident effects on DTR. In the mid-latitudes (e.g., North America, South America and Eurasia), the decreases in DTR are mainly caused by decreasing in daily maximum temperature, which is closely related to LUCC through enhancing the latent heat fluxes, and thus the cloud cover increased. In East Asia and India, however, the impacts of canopy SAR 405 and transpiration induce both the latent heat and cloud cover to be lower. The reasons for the decreasing in DTR in East Asia are the reduction of daily maximum temperature, while in India it mainly depends on the increases in daily minimum temperature with the influences of changes in evaporation and surface albedo. The differences between the DTR responses to LUCC in low and mid-latitudes. The greater changes in albedo in East Asia (three times as that in India) and the stronger effects of canopy evaporation and transpiration in India (twice as high as that in East Asia) may be the major causes. Generally, LUCC in East Asia reduces the gain of solar radiation followed by a decrease in daily maximum temperature, whereas the significant decrease in evapotranspiration is responsible for the increase in daily minimum temperature.
Dai et al. [1999] found that LUCC can affect the DTR through evapotranspiration. The results of this study indicate that the effects of LUCC are highly regionalized phenomenon, which can further reveal the physical mechanisms. Additionally, Pitman et al. [2011] demonstrated that the climate background is also important for determining the climatic responses of LUCC. For example, the variations in snow and precipitation pattern can change the surface albedo and the hydrological cycle, which dominates the regional climate effects of LUCC. The incorporation of current climate characteristics (e.g., solar radiation and other natural forcing) may introduce some uncertainties in the conclusions. Hua and Chen [2013] also pointed out that the climate characteristics seem to play an important role on the regional impact of LUCC, especially at high latitudes. In this study, we only investigated the possible causes of DTR change induced by LUCC from aspects of solar radiation, cloud cover, and evaporation. However, aerosol also plays an important role on DTR. Thus, various factors should be considered in future research to better understand the impacts of LUCC on DTR.

Fig Long term trend of the

Fig. 2. Long-term trend of the annual means of total phosphorus (TP) in water of L. Arendsee as volume weighted concentration (left axis) and as whole mass (right axis) (522 sampling dates). Error bars represent the standard deviation.Figure optionsDownload full-size imageDownload high-quality image (218 K)Download as PowerPoint slide
Fig. 3. Total P content in the sediments layers versus cumulative dry mass per area (CDMA) over a twenty year SAR 405 before and after capping with calcareous mud (dark grey layer) at the main sampling point. The mobile P was calculated by the difference between the end point TP of early P diagenesis and the TP in the layers above this point (shadow area) (see also Table 1); extended from Hupfer and Lewandowski (2005).Figure optionsDownload full-size imageDownload high-quality image (152 K)Download as PowerPoint slide
Plake increased on average by 0.26 t yr?1 between 1995 and 2014 (Fig. 2). Within the same period the calculated Pexp was on average 0.37 t yr?1. The P net sedimentation based on sediment core investigations has not changed significantly during recent years (2000-2014). The P amount retained (above the calcareous mud from 1995) increased linearly with time (Fig. 4). The longer the time elapsed since 1995, the lower the influence of the mobile P pool on the reliability of calculating P retention using sediment cores. The linear relationship in Fig. 4 could be used to calculate the mobile P pool, which is the y-axis intercept. The value calculated this way (1.04 g m?2) agrees well with the value determined by the gradient method (0.95 ± 0.32 g m?2, n = 5, see also Table 1). The slope of the line represents the P retention rate (0.34 g m?2 yr?1) and is in concordance with former P retention rates determined using dated sediment cores (Hupfer and Lewandowski, 2005). A value of Psed of 1.0 t yr?1, which was calculated using the lake area below 30 m depth, is used for further considerations. Considering reference depths of 15 m and 40 m as limits for this calculation, Psed could theoretically vary between 1.24 t yr?1 and 0.7 t yr?1, respectively. Based on Eq. (1)ΔPlake, Pexp, and Psed were summed to yield Pin = 1.63 t yr?1. This load is only slightly higher than the external P load (Pin) of 1.56 t yr?1 determined as sum of all individual P inputs (Meinikmann et al., 2015). In general, differences could be explained by inevitable uncertainties of both approaches and by the different periods of time considered. The single P sources were monitored only for a short period of at most three years. On the other hand, the mass balance approach demands a longer time span to get reliable results. Uncertainties in the mass balance approach according to Eq. (1) include the water residence time and the representative area chosen for the P retention rates determined by sediment cores.
Fig. 4. Total phosphorus retained in the profundal sediments (Deposited P) since end of the year 1995 (as dated by the calcareous capping layer, compare Fig. 3). Randomly sampled sediment cores at water depths deeper than 40 m, between 2000 and 2014. Each data point is the average of 4-7 cores sampled at the same date. Error bars represent the standard deviation. Deposited P increased linearly over time with 0.33 g m?2 yr?1 (n = 10, r2 = 0.969). The intersection with the second axis indicates the mobile P pool of 1.04 g m?2.Figure optionsDownload full-size imageDownload high-quality image (185 K)Download as PowerPoint slide
Our analysis of water and sediment data has shown that certain input data for the one-box model can in part be provided by alternative ways (Table 2). Direct measurements SAR 405 of external P sources are often not available so that sediment core investigations on dated cores can substitute the time-consuming observation of all input paths. In contrast, the Vollenweider model as an example of an empirical model, would drastically overestimate the external P load for L. Arendsee (Table 1). The high Plake compared to Pin, and the mobile P pool in the sediment implicates that 1) the lake internal P pool is the potential starting point for management measures, and 2) the sediment cannot have a delayed effect. The directly measured external P load and the mass balance-based net sedimentation (Table 2) were used in following management scenario analyses (Section 3.2).

SAR 405 For protein purification cells were solubilized mg of cells

For protein purification, SAR 405 were solubilized (200-300 mg of cells/mL) in buffer A (20 mM Tris, pH 8.0, 5 mM MgCl2, 50 mM NaCl, 5% glycerol, 20 μM GDP, 1 mM DTT) containing benzamidine (40.0 μM), leupeptin (0.17 μM), and antipain (0.12 μM). H-RASY137F suspension also contained pefabloc (8.0 μM). Cells were lysed by sonication (60 Sonic Dismembrator from Fisher Scientific) for 30 s at 18 W, followed by 30 s of rest, on ice in a metal cup. Five rounds of sonication were performed. The sonicated lysate was clarified by centrifugation at 14,000 rpm for 20 min at 4 °C. Polyethyleneimine (PEI, 0.02% w/v) was then used to precipitate contaminating nucleic acids and proteins [4] in the lysate supernatant. Precipitation of unwanted macromolecules with PEI was done on ice, while the lysate solution was stirred gently for 30 min. After precipitation, clarification of lysate was again performed by centrifugation at 14,000 rpm for 20 min at 4 °C. Just prior to chromatography, the protein solution was passed through a 0.45 μm pore membrane using syringe filtration to remove remaining cell debris and large protein aggregates.
Chromatography for purification of H-RASY137E and H-RASY137F was done using a ÄKTA FPLC system (GE Healthcare) at 4 °C. The first step was anion exchange (HiPrep™ 16/10 QFF column, 20 mL column volume (cv), GE Healthcare). Binding of mutant H-RAS to a QFF column was done in buffer A without protease inhibitors and at a flow rate of 4 mL/min. After protein binding, the column was washed with two column volumes of buffer A. Protein elution was performed using a 200 mL gradient of 0-40% buffer B (20 mM Tris, pH 8.0, 5 mM MgCl2, 1 M NaCl, 5% glycerol, 20 μM GDP, 1 mM DTT) at 4 mL/min. Fig. 1a and b shows SDS-PAGE of sample fractions coming off the QFF column as the gradient increases. The two mutants are very similar in terms of their migration in this column. H-RasY137E and H-RasY137F eluted off the QFF column at around 15-25% buffer B, which is common for RAS and its mutants. Only the fractions containing a substantial amount of RAS protein were collected for further purification. The second chromatography step was size exclusion (HiPrep™ 26/60 Sephacryl S-100 or S-200 column, 320 mL cv, GE Healthcare) using Buffer A at a rate of 1 mL/min. Fig. 1c shows an example of the gel filtration fractions containing H-RASY137F. This mutant was pure enough at this stage to be used for crystallization. Gel filtration was also performed for H-RASY137E mutant (results are not shown). Some mutants, such as H-RASY137E, require an additional purification step. For this we use a higher resolution, anion exchange chromatography column (HiTrap™ QHP column, 5 mL cv, GE Healthcare). The Y137E protein was bound to the QHP column using buffer A at 4 mL/min. After protein binding, the column was washed with 4 column volumes of buffer A. Protein was eluted from the QHP column using 0-25% buffer B over 200 mL, at a rate of 4 mL/min. Fig. 1d shows the Y137E mutant RAS protein eluted from the QHP column, pure enough to be used for crystallization.
In general, RAS proteins are purified bound to GDP. This was the case for both H-RASY137E and H-RASY137F. However, our interest is in the GTP-bound active state. Since GTP is hydrolyzed to GDP in the experimental time frame for structure determination we loaded RAS with the GTP analog guanylyl-imidodiphosphate (GppNHp). Nucleotide exchange of GDP for GppNHp was performed by first transferring the protein into Nucleotide Exchange (NE) buffer (32 mM Tris pH 8.0, 200 mM ammonium sulfate, 10 mM DTT, and 0.15% N-octylglucopyranoside) using Illustra™ Sephadex™ DNA grade gravity columns (GE Healthcare), following the manufacture?s instructions. Once exchanged into NE buffer, 1 mg of GppNHp, and 50 U of alkaline phosphatase linked to agarose beads (Sigma-Aldrich?) were added per 10 mg of protein. Protein was then gently rotated for 30-60 min at 37 °C. After nucleotide exchange, a concentrated stock solution of MgCl2 was used to bring the protein solution to a final concentration of 20 mM MgCl2. After 5 min at room temperature, the protein solution was exchanged into a stabilization buffer (20 mM HEPES, pH 7.5, 50 mM NaCl, 20 mM MgCl2, 1 or 10 mM DTT). The protein was then concentrated, flash frozen, and stored at ?80 °C until it was used for crystallization. Fig. 2 shows SDS-PAGE for the purified H-RASY137E and RASY137F proteins prior to crystallization.