Biodesulfurization (BDS) is an environmentally friendly desulfurizing process with the potential of replacing or adding to the current expensive technologies for sulfur removal from fossil fuels. The ...BDS, however, still suffers from low biocatalyst activity. One reason is repression of
promoter transcription in presence of inorganic sulfate that impedes translation of Dsz enzymes required for desulfurization pathway. One approach to solve this problem is replacing the native promoter with a new promoter that is no longer repressed. In this study,
genes from desulfurizing strain
sp. FUM94 was cloned in an alkane responsive promoter, pCom8, and expressed in
BL21 (DE3) as a host. The recombinant was not susceptible to inorganic sulfate in the culture medium. Desulfurizing activity of recombinant strain versus wild type indicated that in a sulfate containing medium, BDS yield of recombinant increased from 16.0% ± 0.9 to 34.0% ± 1.9% when dibenzothiophene (DBT) concentration (dissolved in ethanol) increased from 25 to 100 ppm. Also, 2-hydroxy biphenyl (2-HBP) production rate improved 8.5-fold (from 0.302 ± 0.020 to 2.57 ± 0.14 mmol 2-HBP (kg DCW)
h
) at the same DBT concentration range. This is while no 2-HBP production was detected in FUM94 biphasic reaction. In a sulfate-free medium, wild type strain demonstrated desulfurization activity, but decreasing with the increase of DBT concentration dissolved in
-tetradecane. Whereas, the recombinant strain demonstrated increasing desulfurizing activity in a sulfate-containing high DBT concentration environment. Overall, the result of this molecular manipulation can be considered as a step forward toward commercialization of BDS technology.
We present a Hubble Space Telescope/Wide Field Planetary Camera 2 weak-lensing study of A520, where a previous analysis of ground-based data suggested the presence of a dark mass concentration. We ...map the complex mass structure in much greater detail, leveraging more than a factor of three increase in the number density of source galaxies available for lensing analysis. The "dark core" that is coincident with the X-ray gas peak, but not with any stellar luminosity peak, is now detected with more than 10sigma significance. The ~1.5 Mpc filamentary structure elongated in the NE-SW direction is also clearly visible. Taken at face value, the comparison among the centroids of dark matter, intracluster medium, and galaxy luminosity is at odds with what has been observed in other merging clusters with a similar geometric configuration. To date, the most remarkable counterexample might be the Bullet Cluster, which shows a distinct bow-shock feature as in A520, but no significant weak-lensing mass concentration around the X-ray gas. With the most up-to-date data, we consider several possible explanations that might lead to the detection of this peculiar feature in A520. However, we conclude that none of these scenarios can be singled out yet as the definite explanation for this puzzle.
The flow control valve is able to deliver an almost constant discharge which is irrespective to the pressure fluctuations in a pressurized network. In this paper the design of a flow control device ...for incompressible flow is studied. The design criteria of the device are extended for wider discharge values up to Q = 0.6 l/s and differential pressure limits up to Δp = 20 m. In this regard, experiments were performed on cylindrical orifice device to obtain the associated discharge formula, based on which, the initial valve design was obtained. Then, the performance of the flow control device was enhanced according to analyzing the experimental results of the initial design and modifying the float shape line. A step-by-step design framework was then proposed based on which the improved design criteria were achieved for the design discharges of Q = 0.4 l/s with 1≤Δp (m)≤7, Q = 0.6 l/s with 1≤Δp (m)≤7, and Q = 0.6 l/s with 2.6≤Δp (m)≤20. According to the experimental results, average discharge values of 0.391 l/s, 0.625 l/s, and 0.568 l/s, with the associated relative errors of 2.2%, 4.2%, and −5.3% were obtained in comparison with the design values.
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•The design criteria for a Mechanical Choked Orifice Plate device is studied experimentally.•A step-by-step experimental approach is proposed to extend the design parameters.•The proposed control valve delivers an almost flow rate even if the differential pressure increases up to 20 m.
This study was conducted to investigate the effects of different levels of black cumin seeds (Nigella sativa L.) on performance, intestinal Escherichia coli count and morphology of jejunal epithelial ...cells in laying hens. A total of 100 Leghorn laying hens (Hy‐Line W‐36) of 49 weeks old were randomly distributed among five cage replicates of five birds each. Experimental diets consisted of different levels (0%, 1%, 2% and 3% of diet) of dietary black cumin inclusion. The experimental period lasted for a total of 10 weeks, and egg quality indexes and laying hens' performance were measured as two 35‐day trial periods. At the final day, two hens per replicate were slaughtered to investigate the influence of dietary treatments on intestinal E. coli colonization and morphology of jejunal cells. Although dietary black cumin in all supplementation levels decreased (p < 0.05) the enumeration of ileal E. coli, the morphological and histological alterations in small intestine such as enhancement of villus height to crypt depth ratio, increased goblet cell numbers and proliferation of lamina propria lymphatic follicles were observed after dietary supplementation with at least 2% black cumin. Dietary treatments decreased (p < 0.05) the concentration of serum cholesterol and triglycerides and increased (p < 0.05) serum HDL concentration and relative weight of pancreas; however, the egg yolk cholesterol was not influenced by dietary treatments. In addition, dietary supplementation with black cumin improved (p < 0.05) eggshell quality and Haugh unit. The best feed conversion ratio was obtained when diets were supplemented with 2% black cumin. This improvement was due to the increase (p < 0.05) in egg mass and contemporaneous decrease (p < 0.01) in feed consumption. The present results indicated that regardless of supplementation level, dietary inclusion of black cumin decreased E. coli enumeration in ileal digesta and improved serum lipid profile and eggshell quality, whereas the best intestinal health indices and haying hens' performance were obtained by at least 2% black cumin seeds.
The objective of this study was to investigate the effects of an enzymatically hydrolyzed cottonseed protein (HCSP) as a peptide source on performance, blood metabolites, gastrointestinal ...development, and intestinal microbes. Forty-eight newborn Holstein calves were randomly assigned to 1 of the 4 dietary treatments including 0, 2, 4, and 6% of HCSP (dry matter basis). All calves received the same amount of pasteurized whole milk, weaned on d 56 of the experiment, and the study was concluded on d 70. Data were analyzed using PROC MIXED in SAS (SAS Institute Inc., Cary, NC) as a randomized complete block design with linear and quadratic contrasts. Results showed that increased amount of HCSP linearly decreased the starter intake during the postweaning (d 57 to 70) and overall period (d 1 to 70). In addition, when dietary HCSP increased during the overall period, average daily gain tended to linearly decrease. All skeletal growth variables also linearly decreased as dietary HCSP increased at the end of the study, except for body length, which did not differ among the treatments. Serum cortisol concentration was higher in calves supplemented with 6% of HCSP at weaning and at the end of the study. This indicates that these calves may have experienced a stressful condition compared with calves in other treatments. Total antioxidant capacity was quadratically affected by HCSP supplementation; calves fed 2 and 4% of HCSP diets had the highest total antioxidant capacity, whereas calves fed 0 and 6% HCSP diets had lower total antioxidant capacity at weaning and at end of the study. Calves supplemented with 6% HCSP had lower empty reticulo-rumen and omasum weights and rumen wall thickness compared with calves in other treatments at the end of the study. In conclusion, supplementation of HCSP at the rate of 2% of starter diet enhanced antioxidant status without any detrimental effects on the performance and metabolic status of calves, whereas greater inclusion rates impaired starter intake and growth of calves, and exposed them to a stressful status.
Many crucial cellular operations such as metabolism, signalling, and regulations are based on protein-protein interactions. However, the lack of robust protein-protein interaction information is a ...challenge. One reason for the lack of solid protein-protein interaction information is poor agreement between experimental findings and computational sets that, in turn, comes from huge false positive predictions in computational approaches. Reduction of false positive predictions and enhancing true positive fraction of computationally predicted protein-protein interaction datasets based on highly confident experimental results has not been adequately investigated.
Gene Ontology (GO) annotations were used to reduce false positive protein-protein interactions (PPI) pairs resulting from computational predictions. Using experimentally obtained PPI pairs as a training dataset, eight top-ranking keywords were extracted from GO molecular function annotations. The sensitivity of these keywords is 64.21% in the yeast experimental dataset and 80.83% in the worm experimental dataset. The specificities, a measure of recovery power, of these keywords applied to four predicted PPI datasets for each studied organisms, are 48.32% and 46.49% (by average of four datasets) in yeast and worm, respectively. Based on eight top-ranking keywords and co-localization of interacting proteins a set of two knowledge rules were deduced and applied to remove false positive protein pairs. The 'strength', a measure of improvement provided by the rules was defined based on the signal-to-noise ratio and implemented to measure the applicability of knowledge rules applying to the predicted PPI datasets. Depending on the employed PPI-predicting methods, the strength varies between two and ten-fold of randomly removing protein pairs from the datasets.
Gene Ontology annotations along with the deduced knowledge rules could be implemented to partially remove false predicted PPI pairs. Removal of false positives from predicted datasets increases the true positive fractions of the datasets and improves the robustness of predicted pairs as compared to random protein pairing, and eventually results in better overlap with experimental results.
The objective of the current study was to examine whether step-down (STP) milk feeding method together with forage provision would improve performance, rumen fermentation, nutrient digestibility, ...blood metabolites, and structural growth of calves. Holstein bull calves ( = 40) were randomly assigned to 1 of 4 treatments in a completely randomized design with a 2 × 2 factorial arrangement. Treatments were 1) conventional (COV) milk feeding without forage provision (COV-NF), 2) COV milk feeding with forage provision, 3) STP milk feeding without forage provision, and 4) STP milk feeding with forage provision. Calves in the COV method ( = 20) received 5.5 L/d milk until d 56 of age followed by 2 L/d milk from d 56 to 59 of age. Calves in the STP method ( = 20) received 7 L/d milk until d 35, 4 L/d milk from d 35 to 48, and 2 L/d milk from d 50 to 59 of age. All the calves received the starter ration from d 3 of the study until d 74 of age. Forage-supplemented calves ( = 10/milk feeding method) received 15% alfalfa hay mixed with finely ground starter as a total mixed ration. All calves were weaned on d 60 of age and remained in the study until d 74. Regardless of the milk feeding method, the final BW (92.54 vs. 83.14 kg/d), starter intake (0.90 vs. 0.65 kg/d), total DMI (1.43 vs. 1.17 kg/d), and ADG (0.73 vs. 0.60 kg/d) were greater ( < 0.01) in forage-supplemented calves than those that received no forage during the preweaning, postweaning, and overall periods. Milk feeding method had no effect on ruminal pH, total VFA, acetate, or acetate:propionate ratio as well as body measurements. Ruminal pH and the molar proportions of acetate were greater ( < 0.05) in the forage-supplemented calves than those that received no forage during the pre- and postweaning periods. Regardless of forage provision, STP methods increased ( < 0.05) the postweaning numbers of monocytes and lymphocytes. Overall, there was no interaction between milk feeding methods and forage provision with respect to BW, DMI, G:F, apparent nutrient digestibility (DM, OM, and CP), and body measurements. The interaction of milk feeding method and forage provision was significant for the rumen concentration of butyrate ( < 0.05), with the highest concentration for the COV-NF treatment on d 35 of the study. In conclusion, independent of the milk feeding method, inclusion of 15% alfalfa hay in starter diets enhances the performance of dairy calves.
An activated carbon with high adsorption capacity was synthesized from walnut shell as a solid waste using different chemical reagents. It was used to mitigate chemical oxygen demand from municipal ...landfill leachate. The activated carbon synthesized with impregnation ratio of 4:1 (H
3
PO
4
to char) at a temperature of 500°C (ACH4-500) demonstrated the best textural properties based on Brunauer-Emmett-Teller analysis, i.e., specific surface area of 1,851.1 m
2
/g, total pore volume of 1.03 cm
3
/g, and mean pore diameter of 2.24 nm and was selected for adsorption experiments. The maximum adsorption capacity and removal were 123.1 mg/g and 84.7% under optimum condition, respectively. The equilibrium data were fitted with different model isotherms and Redlich-Peterson model showed the best match with experimental data. Kinetic data were well described by pseudo-second-order equation. Study of adsorption thermodynamics revealed spontaneous and endothermic nature of adsorption. In addition, the adsorbent showed satisfactory results, e.g., 100% removal of Pb
2+
, Cd
2+
, and Mn
2+
, in diminishing heavy metals as hazardous materials from landfill leachate.
Summary
This study was carried out to assess the effects of different levels of sanguinarine on antioxidant indices, immunological responses, serum biochemical parameters, ileal microbial counts and ...jejunal morphology of laying hens fed on diets with different levels of crude protein (CP). A total of 180 laying hens were subjected into nine dietary treatments with four cages of five birds each. Experimental treatments consisted of three levels of CP (85.0, 92.5 and 100% of Hy‐Line W36 manual recommendation) and three levels of sanguinarine (0.00, 3.75 and 7.50 mg/kg) as a 3 × 3 factorial arrangement of laying hens which fed during a 70‐day feeding trial. The in vitro study showed that sanguinarine exhibited sevenfold and threefold decreased antioxidant activities to inhibit 2‐2‐diphenyl‐1‐picric hydrazyl free radical as well as ferric ion reducing rather than butylated hydroxyl toluene. Although using the decremental levels of CP caused the increase in heterophil‐to‐lymphocyte ratio (p < 0.01), dietary administration of sanguinarine could suppress the serum cholesterol and malondialdehyde concentrations as well as heterophil‐to‐lymphocyte ratio (p < 0.05). Additionally, decreasing CP content resulted in the decreased percentage of albumin (p < 0.05); however, it had no negative effects on humoral immunity. Nonetheless, feeding of at least 3.75 mg/kg sanguinarine led to the remarkable increases in serum gamma globulin concentration (p < 0.01) and secondary (p < 0.05) antibody titres against sheep red blood cells. Moreover, a decline in dietary CP content led to higher villi height and crypt depth (p < 0.05; p < 0.001) and consequently decreased villi height‐to‐crypt depth ratio (p < 0.001) than the optimum level (100% CP). In spite of the effects of sanguinarine on the suppression of Escherichia coli and Salmonella counts (p < 0.05), it markedly enhanced villi height‐to‐crypt depth ratio as well as lamina propria lymphatic follicles extent, simultaneously (p < 0.001). Therefore, in spite of the detrimental effects of feeding low‐CP diets on lymphocytes and serum albumin percentages, and villi height‐to‐crypt depth ratio, the administration of incremental levels of sanguinarine could improve cellular and humoral immunity, decrease ileal microbial counts and in turn improve the intestinal health indices in laying hens.
Ductile failure of structural metals is relevant to a wide range of engineering scenarios. Computational methods are employed to anticipate the critical conditions of failure, yet they sometimes ...provide inaccurate and misleading predictions. Challenge scenarios, such as the one presented in the current work, provide an opportunity to assess the blind, quantitative predictive ability of simulation methods against a previously unseen failure problem. Rather than evaluate the predictions of a single simulation approach, the Sandia Fracture Challenge relies on numerous volunteer teams with expertise in computational mechanics to apply a broad range of computational methods, numerical algorithms, and constitutive models to the challenge. This exercise is intended to evaluate the state of health of technologies available for failure prediction. In the first Sandia Fracture Challenge, a wide range of issues were raised in ductile failure modeling, including a lack of consistency in failure models, the importance of shear calibration data, and difficulties in quantifying the uncertainty of prediction see Boyce et al. (Int J Fract 186:5–68,
2014
) for details of these observations. This second Sandia Fracture Challenge investigated the ductile rupture of a Ti–6Al–4V sheet under both quasi-static and modest-rate dynamic loading (failure in
∼
0.1 s). Like the previous challenge, the sheet had an unusual arrangement of notches and holes that added geometric complexity and fostered a competition between tensile- and shear-dominated failure modes. The teams were asked to predict the fracture path and quantitative far-field failure metrics such as the peak force and displacement to cause crack initiation. Fourteen teams contributed blind predictions, and the experimental outcomes were quantified in three independent test labs. Additional shortcomings were revealed in this second challenge such as inconsistency in the application of appropriate boundary conditions, need for a thermomechanical treatment of the heat generation in the dynamic loading condition, and further difficulties in model calibration based on limited real-world engineering data. As with the prior challenge, this work not only documents the ‘state-of-the-art’ in computational failure prediction of ductile tearing scenarios, but also provides a detailed dataset for non-blind assessment of alternative methods.
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