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Effective recognition of radar jamming is of great importance in improving radar system's anti-jamming capability. Existing radar jamming recognition methods based on convolutional neural networks suffer from limitations such as low recognition accuracy and poor network stability in complex electromagnetic environments. This is due to incomplete extraction and utilization of useful information from the jamming signal. In this article, a few-shot adaptive confidence aggregation and cross-modal refinement jamming recognition (JR-ACAR) method is designed to mine the complete information of the jamming signal for enhancing both accuracy and robustness of the method. An adaptive confidence aggregation model is proposed to fully exploit the complementary information between the modulus, phase, and real and imaginary parts of the input time–frequency spectrum of jamming signal and adaptively aggregate this information by confidence vectors. Moreover, to further improve the recognition accuracy while enhancing the robustness of the network, a cross-modal refinement model is proposed to mine the correlation information between the aggregated jamming recognition result and the original input time–frequency image. Experimental results on both simulated and measured mixed dataset validate that the proposed JR-ACAR method is superior to the existing methods for radar jamming recognition in terms of recognition accuracy and robustness.

In high-resolution and wide-swath synthetic aperture radar (SAR) systems, there are azimuth Doppler ambiguity and ghost ground moving targets (GMTs). Incorporated with an improved equivalent range model (IERM), this article explores a simultaneous scene imaging and GMT indication (GMTI) scheme with multiple beamforming for hypersonic vehicle-borne dive-trajectory high-squint multichannel SAR (HSV-DTHS-MC-SAR). First, the coarse-focusing imageries are recovered. Then, the CTV estimation with the dynamic-eigenspace-based adaptive sum and difference beams (EASDBs) is explored. After that, the SAR scene processing which enjoys “customized” beamforming, minimizes the ghost GMT and reconstructs the ambiguity-free scene image. Moreover, the proposed clutter suppression method generates the beamformer center in the desired GMT direction and reduces the beamformer sidelobe by using quadratic pattern constraints. Finally, the geometry and inverse projections are performed to calibrate the distortion arising from vertical velocity. Compared to the existing methods, the proposed scheme has innovations or improvements in CTV estimation, scene recovery, and cutter suppression. To be specific, it avoids the cumbersome CTV search and thus has lower computation, enjoys more concise and robust removal of ghost GMT in the scene, and frees the steering vector mismatch plus achieves a higher signal-to-clutter-and-noise ratio (SCNR). The extensive simulations confirm the effectiveness of our proposed scheme.

Due to the flexible configuration and maneuvering platform, bistatic synthetic aperture radar (BiSAR) plays an important role in modern remote sensing applications, but the nonideal track simultaneously introduces model mismatch and spatial-variant phase problems. This article proposes a subaperture (SA) parametric polar format algorithm (PFA) for high-resolution bistatic spotlight SAR (BSSAR) imaging. First, a bistatic parametric PFA (BPPFA) is proposed to focus on the generally configured BiSAR data. A high-precision range model in the bistatic range and ellipsoid parameter angle coordinate space is established to modify the PFA interpolation kernels. To further enhance the azimuth resolution, the PFA subimages are fused in the image domain based on the coordinate transformation between the unified Cartesian coordinates and local imaging polar coordinates. During the subimage fusion, in order to ensure the accurate projection and nonaliasing spectrum, we also consider the geometric deformation of the coarse PFA image and analyze the wavenumber support region along with the Nyquist sampling requirement. This novel SA method, which is theoretically more efficient than the fast back-projection algorithm (BPA), alleviates the limitation of full aperture resolution on PFA’s depth of focus (DOF). Finally, our method is applied to the general BSSAR data, involving the level-flight airborne transmitter and the dive hypersonic vehicle-borne receiver, and the results of both points and distributed targets demonstrate its effectiveness and efficiency.

Radar jamming recognition aims to accurately recognize the type of jamming to provide guidance for radar countermeasures. Although previous deep learning-based methods have made promising performance, they mainly rely on convolutional neural network (CNN) based on local processing, which ignore the global information in the time-frequency domain data of the jamming signal and also require much inference time to obtain the final recognition results. In this article, a novel few-shot jamming recognition network via time-frequency self-attention and global knowledge distillation (JR-TFSAD) is proposed by jointly considering the global information in the time-frequency spectrum of the jamming signal and the real-time performance of the recognition network. A time-frequency self-attention (TFSA) model is proposed to extract the global deep features of radar jamming signals by learning the correlation between two arbitrary points in the time-frequency spectrum of the jamming signal, thus improving the recognition accuracy. Moreover, to effectively reduce the inference time of the method while preserving the recognition accuracy, a global knowledge distillation (GKD) model is further constructed to perform jamming recognition by distilling the global knowledge from the TFSA model. The experimental results on the simulated and measured mixed dataset verify that the proposed method has higher recognition accuracy and shorter inference time compared to the state-of-the-art methods.

Orthogonal frequency division multiplexing (OFDM) is often used in integrated radar and communication (IRC) systems to improve the sharing of scarce spectrum resources and develop efficient solutions for intelligent vehicles. However, the communication symbols and pilot information carried by the integrated signal and the cyclic prefix of OFDM greatly limit the performance of the radar and communication. In this paper, we propose a joint sequence optimization-based OFDM waveform design method for IRC. First, the ambiguity function of the OFDM signal block and guard interval (GI) sequence are deduced in detail, and a new composite sequence with the cascading of Walsh code and m sequence is used to optimize the correlation of communication information, resulting in better ambiguity function characteristics. Then, a multivariate optimization model is explored, and the constrained particle swarm optimization algorithm based on weight allocation (WCPSO) is proposed to obtain the optimal GI sequence. It has lower sidelobe levels and higher information transmission efficiency. In addition, an improved received signal processing method is introduced to achieve stable communication synchronization and high-resolution distance and velocity estimation of multiple targets radar detection. Finally, numerical simulation results are presented to validate the effectiveness of the proposed method.

Lysozyme is often used as a feed additive to act as an antibacterial protein that boosts the immune system of livestock and poultry while protecting against pathogens. To investigate the effects of recombinant human lysozyme (rhLYZ) from Pichia pastorisand chlortetracycline on broiler chicken’s production performance, antioxidant characteristics, and intestinal microbiota, a total of 200, 1-d-old male Arbor Acres broiler chickens (46.53 ± 0.42 g) were selected for a 42-d experiment. Dietary treatments included a basal diet of corn-soybean meal supplemented with either 0 mg/kg (CON), 50 mg/kg aureomycin (ANT), 20 mg/kg rhLYZ (LOW), 60 mg/kg rhLYZ (MEDIUM), or 180 mg/kg rhLYZ (HIGH). Compared with CON, MEDIUM diet increased (P< 0.05) average daily gain (67.40 g) of broilers from day 22 to 42. In the early (1.29) and overall phases (1.69), MEDIUM led to a reduction (P< 0.05) in the feed conversion ratio of broiler chickens. Furthermore, in comparison to the CON and ANT, MEDIUM exhibited reduced (P< 0.05) levels of INF-γ and tumor necrosis factor-α in the serum. In the cecum, the abundance of Monoglobus and Family_XIII_AD3011_group was lower (P< 0.05) in the MEDIUM treatment compared to CON. Overall, supplementation of 60 mg/kg of rhLYZ improved growth performance, nutrient utilization efficiency, and serum immune function, while also influencing the composition of intestinal microbiota. This suggests lysozyme’s potential to replace antibiotic additives in feed.The study revealed that, through a 42-d experiment, the addition of 60 mg/kg of recombinant human lysozyme to broiler chickens’ feed led to significant improvements in average daily gain, feed conversion ratio, and serum immune markers. Furthermore, this supplementation influenced the composition of their intestinal microbiota, presenting a promising alternative to antibiotic use in poultry production.The aim of this study was to explore the effects of recombinant human lysozyme (rhLYZ) produced from Pichia pastorisand chlortetracycline on broiler chicken performance, antioxidant properties, and gut microbiota. A 42-d experiment was conducted, involving 200 1-d-old male Arbor Acres broiler chickens. We provided different diets: a standard diet (CON), a diet with 50 mg/kg aureomycin (ANT), a diet with 20 mg/kg rhLYZ (LOW), a diet with 60 mg/kg rhLYZ (MEDIUM), or a diet with 180 mg/kg rhLYZ (HIGH). The results showed that, compared to the control group, the MEDIUM group significantly increased the average daily gain of broilers to 67.40 g from day 22 to 42. Additionally, the MEDIUM group exhibited a reduced feed conversion ratio during both the early and overall growth stages of the chickens. Furthermore, serum levels of INF-γ and tumor necrosis factor-α were lower in the MEDIUM group compared to both the CON and ANT groups. In the cecum, the abundance of Monoglobus and Family_XIII_AD3011_group was also lower in the MEDIUM treatment compared to the CON group. Overall, supplementation with 60 mg/kg of rhLYZ improved growth performance, nutrient utilization efficiency, and serum immune function in broiler chickens while also influencing the composition of their intestinal microbiota. This suggests the potential of lysozyme as a replacement for antibiotic additives in feed.

A strain of Bacillus subtilis(MAFIC Y7) was isolated from the intestine of Tibetan pigs and was able to express high protease activity. The aim of this study was to characterize the proteases produced by MAFIC Y7, and to investigate the effects of protease addition on growth performance, ileal amino acid digestibility, and serum immunoglobulin and immune factors of broilers fed SBM-based diets, or on growth performance, carcass characteristics, and intestinal morphology of broilers fed CSM-based diets. B. subtilis(MAFIC Y7) expressed protease showed its optimal enzyme activity at 50 °C and pH 7.0. The coated crude enzyme (CCE) showed greater stability at pH 3.0 than its uncoated counterpart. Experiment 1 was conducted with six diets based on three levels of crude protein (CP)—CPlow, CPmedium, and CPhigh—with or without CCE. In CPlow, CCE increased gain:feed (G:F) (days 1 to 21, days 1 to 42) by 8%, 3%, respectively, and enhanced apparent ileal digestibility (AID) of crude protein and lysine (on day 42) by 8.8%, 4.6%, respectively, compared with diets containing no CCE (P< 0.05). CCE increased G:F from days 1 to 21 from 0.63 to 0.68, improved G:F and average daily gain (ADG) during days 1 to 42, and enhanced AID of crude protein, lysine, cysteine, and isoleucine on day 42 compared with the unsupplemented treatments (in CPmedium, P< 0.05). CCE increased serum IgA (on day 21), serum IgA and IgG and increased serum IL-10 (on day 42), but decreased serum tumor necrosis factor-α (TNF-α; on day 21), and serum IL-8 and TNF-α (on day 42) compared with unsupplemented treatments. At CPhigh, CCE decreased serum levels of IL-6 and TNF-α (on day 21), and IL-8 and TNF-α (on day 42) compared with unsupplemented treatments (in CPhigh, P< 0.05). In experiment 2, CSM-based diets with two lysine-to-protein ratios (5.2% or 5.5%) with or without CCE. In the high Lys diet (5.5% Lys:protein), CCE increased ADG and G:F, increased carcass, but decreased abdominal fat compared with the unsupplemented treatment (P< 0.05). In the 5.2% Lys:protein dietary treatment, CCE improved duodenal villus height compared with the unsupplemented treatment (P< 0.05). Supplementation of protease produced by MAFIC Y7 was associated with lower inflammatory responses in SBM diets (CPmediumor CPhigh) and improved ADG in broilers fed CPmediumor CPhigh. The proteases improved ADG and the efficiency of CSM use when the ratio of Lys to protein was 5.5%.The aim of this study was to investigate the effects of Bacillus subtilis(MAFIC Y7)-expressed protease on growth performance, G:F and inflammatory responses elicited by soybean meal (SBM) diets and cottonseed meal in broilers.The aim of this study was to investigate the effects of Bacillus subtilis(MAFIC Y7)-expressed protease on reducing inflammatory responses of soybean meal (SBM) diets and improving the efficiency of cottonseed meal (CSM) in broilers. Experiment 1 was conducted with six dietary treatments based on three levels of crude protein (CP)—CPlow, CPmedium, and CPhigh—without or with proteases (0 or 4,000 U/kg). Supplementation of proteases significantly improved growth performance, gain:feed (G:F), and apparent ileal digestibility of crude protein and amino acids (cysteine, isoleucine, and histidine) in broilers fed CPmediumtreatment (P< 0.05). Proteases inhibited inflammatory responses in SBM-based diets by decreasing serum tumor necrosis factor-α (TNF-α) (in CPmediumand CPhigh), and interleukin (IL)-6 (in CPhigh); and IL-8 and TNF-α (in CPmediumand CPhigh) on day 21. In experiment 2, broilers were fed with CSM-based diets with two ratios of lysine-to-protein (5.2% or 5.5%) with or without proteases. Proteases in the diet of 5.5% Lys to protein ratio increased growth performance and G:F compared to diets without proteases (P< 0.05). Proteases produced by MAFIC Y7 improved growth performance and G:F in CPmedium. Supplementation of protease was associated with lower inflammatory responses of broilers fed SBM-based diets (CPmediumor CPhigh) and improved the efficiency of CSM use when the ratio of lysine-to-protein was 5.5%.

ABSTRACTLow angle target estimation is always a difficult problem for radar elevation estimation. Multiple-input multiple-output (MIMO) radar can increase array degree of freedom and resolution, and improve the low angle target measurement precision. At the same time, the computation complexity of the MIMO radar is also increasing, especially for non-uniform linear array (ULA) configuration in which some fast algorithms cannot be used. In this paper, a fast low angle target estimation method is proposed for monostatic MIMO radar with arbitrary array configurations. With the array interpolation and the quasi-spatial-smoothing technique, the MIMO steering vector can be transformed into a virtual low dimension (typical similar size as the number of array elements) ULA steering vector. Then, the polynomial rooting algorithm is used to estimate the elevation of the low angle target. The simulation results of the proposed algorithm are presented and the performances are investigated and analysed.

In this paper, we utilize a space-time coding (STC) scheme to synthesize the multiple-input multiple-output (MIMO) radar transmit beampattern and meanwhile consider the matched filtering loss (MFL) of equivalent signal in waveform design. To solve the MFL optimization problem, we propose a simulated annealing based (SA-based) algorithm to effectively find the optimal solution of STC waveform matrix. Our STC method for waveform design has suppressed the fluctuation of equivalent signal so that has the advantage of achieving the minimum MFL nearly, compared to the conventional methods for constant-envelope constraint waveform design (e.g. cyclic algorithm (CA) method). Simulation results demonstrate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a novel clutter suppression and ground moving target imaging approach is proposed for hypersonic vehicle (HSV) borne multichannel (MC) synthetic aperture radar (SAR) system. Compared with the traditional MC SAR ground moving target indication (GMTI) methods, the proposed algorithm can suppress clutter and decrease the moving target energy loss based on the improved MC clutter suppression method in the chirp Fourier transform (CFT) domain. Moreover, the moving target can be accurately focused by compensating the range curvature and the third order phase item. In addition, the motion parameters can be estimated precisely and the moving target can be focused accurately. Finally, the effectiveness of the proposed method is validated by the simulation examples. [ABSTRACT FROM AUTHOR]

In this paper, we propose a joint optimization method to reduce peak-to-average power ratio (PAPR) for multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) radar systems, based on the modified tone-reservation (TR) scheme which has sufficient degree of freedom to satisfy some special and meaningful waveform design criteria. In terms of applying independent or concurrent reserved subcarrier weights for transmit antennas, we provide two PAPR reduction schemes respectively, i.e., independent TR (ITR) and concurrent TR (CTR). It is demonstrated that the proposed joint optimization method can effectively reduce the PAPR to an acceptable threshold and is superior to the conventional methods. Note that the optimized OFDM waveforms for MIMO radar can avoid the grating-lobes in distance domain. Simulation results are presented to verify the derivations. [ABSTRACT FROM AUTHOR]

In this paper, a clutter suppression and ground moving target imaging algorithm is proposed for the hypersonic vehicle (HSV) borne multichannel synthetic aperture radar (SAR) system. Different from the traditional horizontal flight radar platforms, the HSV-borne radar platform is with a complex movement, and typically has a skipping trajectory. Therefore, the clutter suppression and imaging operations are difficult to implement. To deal with this problem, a descending stage signal model of multichannel SAR system is presented and studied for the HSV-borne radar. Then, the clutter and moving target echoes are transformed into the azimuth frequency domain. Considering that there exists a phase difference between clutter and the moving target, the clutter suppression approach is implemented with a series of spatial domain filters. After that, the moving target is focused based on the keystone transform. In addition, the performance analyses and related issues of the proposed method are presented. Finally, some simulation experiments are taken to validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Development of three-dimensional nanoarchitectures on current collectors has emerged as an effective strategy for enhancing rate capability and cycling stability of the electrodes. Herein, a new type of three-dimensional porous iron vanadate (Fe0.12V2O5) nanowire arrays on a Ti foil has been synthesized by a hydrothermal method. The as-prepared Fe0.12V2O5nanowires are about 30 nm in diameter and several micrometers in length. The effect of reaction time on the resulting morphology is investigated and the mechanism for the nanowire formation is proposed. As an electrode material used in lithium-ion batteries, the unique configuration of the Fe0.12V2O5nanowire arrays presents enhanced capacitance, satisfying rate capability and good cycling stability, as evaluated by cyclic voltammetry and galvanostatic discharge–charge cycling. It delivers a high discharge capacity of 293 mAh·g–1at 2.0–3.6 V or 382.2 mAh·g–1at 1.0–4.0 V after 50 cycles at 30 mA·g–1.

Two chimeric genes, XynA-Bs-Glu-1 and XynA-Bs-Glu-2, encoding Aspergillus sulphureus β-xylanase (XynA, 26 kDa) and Bacillus subtilis β-1,3-1,4-glucanase (Bs-Glu, 30 kDa), were constructed via in-fusion by different linkers and expressed successfully in Pichia pastoris. The fusion protein (50 kDa) exhibited both β-xylanase and β-1,3-1,4-glucanase activities. Compared with parental enzymes, the moiety activities were decreased in fermentation supernatants. Parental XynA and Bs-Glu were superior to corresponding moieties in each fusion enzymes because of lower Kn higher kcat. Despite some variations, common optima were generally 50°C and pH 3.4 for the XynA moiety and parent, and 40°C and pH 6.4 for the Bs-Glu counterparts. Thus, the fusion enzyme XynA-Bs-Glu-1 and XynA-Bs-Glu-2 were bifunctional.

In recent years, α-galactosidase has been attracting more and more attention because of its potential applications in many aspects. Using reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends, a full-length cDNA sequence composed of 2,439 bp was cloned from Penicillium janczewskii zaleski and was subcloned into pPICZαA and transformed into Pichia pastoris strain X-33. In a 10-L fermentor, the recombinant yeast expressed α-galactosidase with a yield of 254 U/mL by methanol induction for 120 h. The recombinant enzyme showed the optimal activity at 40°C and pH 5.2. The K m values of the recombinant enzyme using p-nitrophenyl-α-D-galactopyranoside (pNPG), melibiose, raffinose and stachyose as substrates were 1, 16, 17.8 and 5.3 mM, respectively. V max values were 227.3, 116.7, 104.8, and 80.6 μM/min using pNPG, melibiose, raffinose and stachyose as substrates, respectively. The α-galactosidase exhibited no sensitivity to various metal ions and ethylenediaminetetraacetic acid, and hydrolyzed melibiose, raffinose and stachyose with different levels of galactose release. The biochemical characteristics of the α-galactosidase suggest that the enzyme may have a prospective application in feed industry as an additive.

β-1,3-1,4-Glucanase has been broadly used in feed and brewing industries. According to the codon bias of Pichia pastoris, the Bacillus subtilis MA139 β-1,3-1,4-glucanase gene was de novo synthesized and expressed in P. pastoris X-33 strain under the control of the alcohol oxidase 1 promoter. In a 10-L fermentor, the β-1,3-1,4-glucanase was overexpressed with a yield of 15,000 U/mL by methanol induction for 96 h. The recombinant β-1,3-1,4-glucanase exhibited optimal activity at 40°C and pH 6.4. The activity of the recombinant β-1,3-1,4-glucanase was not significantly affected by various metal ions and chemical reagents. To our knowledge, the expression of this β-1,3-1,4-glucanase from Bacillus sp. in P. pastoris is in relatively high level compared to previous reports. These biochemical characteristics suggest that the recombinant β-1,3-1,4-glucanase has a prospective application in feed and brewing industries.

ABSTRACTCecropin AD, a chimeric antimicrobial peptide obtained from cecropins, is effective at killing specific microorganisms. However, a highly efficient expression system is still needed to allow for commercial application of cecropin AD. For the exogenous expression of cecropin AD, we fused the cecropin AD gene with a small ubiquitin-like modifier (SUMO) gene and a signal peptide of SacB, while a Bacillus subtilisexpression system was constructed based on Bacillus subtiliscells genetically modified by the introduction of an operon including an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible Spac promoter, a signal peptide of amyQ, and the SUMO protease gene. The recombinant cecropin AD was expressed, and 30.6 mg of pure recombinant protein was purified from 1 liter of culture supernatant. The purified cecropin AD displayed antimicrobial activity against some pathogens, such as Staphylococcus aureusand Escherichia coli, and was especially effective toward Staphylococcus aureus, with MICs of <0.05 μM (0.2 μg/ml). Stability analysis results showed that the activity of cecropin AD was not influenced by temperatures as high as 55°C for 20 min; however, temperatures above 85°C (for 20 min) decreased the antimicrobial activity of cecropin AD. Varying the pH from 4.0 to 9.0 did not appear to affect the activity of cecropin AD, but some loss of potency was observed at pH values lower than pH 4.0. Under the challenge of several proteases (proteinase K, trypsin, and pepsin), cecropin AD maintained functional activity. The results indicated that the recombinant product expressed by the designed Bacillus subtilisexpression system was a potent antimicrobial agent and could be applied to control infectious diseases of farm animals or even humans.

β-Mannanase (EC 3.2.1.78) is a key enzyme to hydrolyze the β-mannosidic linkages in mannan and heteromannan. The expression of a wild type β-mannanase (manWT) of Aspergillus sulphureus in Pichia pastoris is not high enough for its application in feed supplement. To earn a high expression level, the manWT gene was firstly optimized to manM according to the code bias of P. pastoris, which was then inserted into pPICzαA and transformed into P. pastoris strain X-33. In the induction by methanol, β-mannanase was expressed in high level with 32% increase in comparison with the manWT gene expressed in P. pastoris in shaken flask. In a 10-L fermenter, the manM was expressed in 9-fold higher level than that in shaken flask, which yielded the enzyme activity of 1100 U/mL. This is the first study on codon bias effect on the β-mannanase gene expression level, which helps to achieve high β-mannanase yield and enzymatic activity in P. pastoris.

β-1, 4-glucosidases generate glucose from cellobiose and oligosaccharides, enhancing the productivity in biorefinery and the bioconversion process as well as the nutritional value in food and feed. With the high-throughput sequencing technique, a novel β-1, 4-glucosidase, named bglT2, containing 861 amino acid residues, was found from Aspergillus fresenii. bglT2 belongs to the glycosyl hydrolase (GH) family 3. The bglT2 that expressed by Komagataella phaffiiX33 presented the highest activity at 55 °C and pH 5.5. The half-lives of bglT2 under 50 °C, 55 °C, 60 °C, and 65 °C were 9 min 36 s, 4 min 22 s, 117 s, and 68 s, respectively. The bglT2 was stable between pH 3.0 to pH 8.0. The Michaelis constant (Km) and the theoretical maximum rate (Vmax) of bglT2 were 0.0007 mol/L and 9 × 10−8mol/L/s, respectively. In a 5 L fermentation vessel, the recombinant K.phaffiiX33 could yield a β-1, 4-glucosidase activity of 4.45 U/mL after 96 h methanol inducement. As an important member of cellulases, the novel bglT2 might contribute to bioenergy, food processing, feed enrichment, and nutritional study, etc. This study also developed a path to obtain new enzymes depending on high-throughput sequencing technique.

An acidic thermostable xylanase (AT-xynA) which was stable at low pH and high temperature was considered to have great potential in animal feed. For large-scale production, AT-xynA activity was enhanced about 1-fold in Pichia pastoris by constructing a double-copy expression strain in this study. Furthermore, impacts of different AT-xynA levels on growth performance, nutrient digestibility, short-chain fatty acids, and bacterial community in weaned piglets were determined. Compared with the control group, ADFI and ADG were higher for the pigs fed 4,000 or 6,000 U/kg AT-xynA (P < 0.05). AT-xynA supplementation also significantly increased the digestibility of OM, GE, and DM (P < 0.05). AT-xynA supplementation increased the concentrations of acetate in ileal (P < 0.01) and cecal digesta (P < 0.05). Isobutyrate (P < 0.05) and valerate (P < 0.05) concentrations in colonic digesta also significantly increased compared with the control group. AT-xynA supplementation increased the abundance of Lactobacillus in the ileal, cecal, and colonic digesta of weaned piglets (P < 0.05). AT-xynA alleviated anti-nutritional effects of nonstarch polysaccharides (NSP) by preventing the growth of Pateurella and Leptotrichia in the ileum (P < 0.05). AT-xynA increased the abundance of NSP-degrading bacteria, such as Ruminococcaceae, Prevotella in the cecum and colon (P < 0.05). In summary, AT-xynA addition could improve the growth performance of weaned piglets by altering gut microbiota.

A Galactomyces geotrichumstrain with lipolytic activity was isolated and identified by the analysis of internal transcribed spacer (ITS) sequence of 18 s rDNA. Full-length lipase gene of this stain is composed of 1692 base pairs (bp) without intron, which encodes a 563-amino-acid protein. A catalytic triad (Ser217–Glu354–His463) was found by constructing the three-dimensional structure of the lipase. In shake flasks, the lipase (LIP) catalytic activity in the supernatant of the recombinant Pichia pastorisincreased 48.7% by codon optimization. LIP purified by anion exchange column showed a single protein band on 12% SDS-PAGE. The molecular weight (MW) of LIP was approximately 62 kDa. The specific activity of purified LIP reached 1257.9 U/mg. The optimum temperature and pH of LIP catalysis were 45 °C and pH 8.2, respectively. LIP was stable over the pH range of 4.2–11.2. LIP maintained its activity constantly at 40 °C and 50 °C for 120 min. Zn2+inhibited LIP activity; Ba2+, Mn2+, Ca2+and EDTA increased the enzyme activity. Referring the amount of hydrolyzed olive oil by LIP as 100%, various oils including lard, peanut oil, rapeseed oil, sunflower oil, soybean oil and linseed oil were efficiently hydrolyzed by 17.24 ± 1.34%, 40.34 ± 2.56%, 105.86 ± 2.78%, 115.51 ± 2.32%, 116.21 ± 2.15%, 120.69 ± 1.98%, respectively. The characteristics allow LIP as a potential biocatalyst in various fields of industry.

In this paper, we propose a modified space-time coding scheme to design transmit waveform for the radar and communication integrated system in the presence of active interferences. Based on the shared co-located MIMO radar, the constraints of communication requirement, waveform orthogonality and active anti-interference are considered for the waveform design. To avoid the loss of information symbols for communication transmission and obtain sufficient anti-interference performance for radar detection, the transmit beam-pattern at each sub-pulse duration time is controlled to maintain the radiation powers unchanged towards communication direction and interference directions, which is distinct to the conventional transmit beamforming design. Furthermore, to tackle the coupling of the time-domain orthogonality and the space-domain beam-pattern, the constant envelope constraint of transmit waveform is relaxed to obtain the degree of freedom for space-time waveform design. Thus the peak-to-average power ratio (PAPR) reduction for transmit waveform is also discussed. Simulation results are finally presented to demonstrate the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]