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1.
J Appl Microbiol ; 133(2): 515-528, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35396768

RESUMO

AIM: Probiotics could improve the health, growth, and development of host or their foetuses/offspring via regulating gut microbiota. The present study was conducted to determine the effects of maternal probiotics supplementation on gut microbiota and metabolites of sows and their suckling piglets, as well as plasma biochemical parameters, oxidative/anti-oxidative indexes, and inflammatory cytokine levels of suckling piglets. METHODS AND RESULTS: A total of 32 pregnant Bama mini-pigs were selected and randomly divided into two groups. The sows were fed a basal diet (control group) or a basal diet supplemented with probiotics (probiotics group) from mating to day 21 of lactation. Samples from sows were collected on day 105 of pregnancy and day 21 of lactation and from piglets on day 21 of lactation. The results showed that probiotics supplementation increased the faecal abundances of Ruminococcus, Bacteroides, and Anaeroplasma and decreased Tenericutes on day 105 of pregnancy while increased the abundances of Actinobacteria and Anaerostipes and decreased Proteobacteria and Desulfovibrio on day 21 of lactation. In addition, probiotics supplementation decreased the faecal levels of tryptamine, putrescine, and cadaverine on day 105 of pregnancy and isovalerate and skatole on day 21 of lactation while increased butyrate level on day 21 of lactation. Further studies showed that maternal probiotics supplementation decreased the plasma levels of AMM, TC, LDL-C, Ala, Tau, MDA, H2 O2 , IL-1ß, IL-2, IL-6, and IFN-α of suckling piglets. Moreover, maternal probiotics supplementation increased the abundances of Deferribacteres, Fusobacteria, and Fusobacterium while decreased Anaerostipes in piglet's colon. Spearman's correlation analysis revealed a potential link between gut microbiota alterations and their metabolites. CONCLUSIONS: Dietary probiotics supplementation during pregnancy and lactation periods could improve sow status, alleviate oxidative stress and inflammation response, and improve nutrient metabolism of piglets by altering the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: The probiotics alter maternal and offspring's gut microbiota involving in offspring's physiological and metabolic changes, and present a new perspective that the effects of gut microbiota changes induced by probiotics supplementation will help in addressing the growth and development and health problem of their foetuses/offspring.


Assuntos
Microbioma Gastrointestinal , Probióticos , Ração Animal/análise , Animais , Animais Lactentes , Antioxidantes/farmacologia , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Lactação , Gravidez , Probióticos/análise , Suínos , Porco Miniatura
2.
J Sci Food Agric ; 102(2): 607-616, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34151432

RESUMO

BACKGROUND: Maternal nutrition during gestation and lactation is essential for offspring's health. The present study aimed to investigate the effects of betaine hydrochloride addition to sow diets during gestation and lactation on suckling piglet's immunity and intestine microbiota composition. Forty Bama mini-pigs were randomly allocated into two groups and fed a basal diet (control group) and a basal diet supplemented with 3.50 kg ton-1 betaine hydrochloride (betaine group) from day 3 after mating to day 21 of lactation. After 21 days of the delivery, 12 suckling piglets from each group with similar body weight were selected for sample collection. RESULTS: The results showed that maternal betaine hydrochloride addition decreased (P < 0.05) the plasma levels of interleukin (IL)-1ß, IL-2, IL-6, and tumor necrosis factor-α in suckling piglets. Furthermore, dietary betaine hydrochloride addition in sow diets increased (P < 0.05) the villus height (VH) and VH to crypt depth ratio in the jejunum and ileum of suckling piglets. In the piglets' intestinal microbiota community, the relative abundances of Roseburia (P < 0.05) and Clostridium (P = 0.059) were lower in the betaine group compared to those in the control group. Moreover, betaine hydrochloride addition in sow diets decreased the colonic tyramine (P = 0.091) and skatole (P = 0.070) concentrations in suckling piglets. CONCLUSION: Betaine hydrochloride addition in sow diets enhanced the intestinal morphology, improved immunity, and altered intestinal microbiota of suckling piglets. These findings indicated that betaine hydrochloride addition in sow diets during gestation and lactation will impact suckling piglets' health. © 2021 Society of Chemical Industry.


Assuntos
Betaína/metabolismo , Microbioma Gastrointestinal , Porco Miniatura/embriologia , Ração Animal/análise , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Animais Recém-Nascidos/imunologia , Animais Recém-Nascidos/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Suplementos Nutricionais/análise , Feminino , Interleucinas/sangue , Lactação , Masculino , Fenômenos Fisiológicos da Nutrição Materna , Gravidez , Suínos , Porco Miniatura/sangue , Porco Miniatura/imunologia , Porco Miniatura/microbiologia , Fator de Necrose Tumoral alfa/sangue
3.
Front Nutr ; 8: 728477, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34513907

RESUMO

Betaine is widely used as feed additives in animal husbandry as it can cause many benefits such as improving antioxidant ability, growth performance, and carcass traits. However, there are limited studies about the effects of betaine on the Bama mini-pigs. The present study was conducted to evaluate the effects of dietary betaine on carcass traits, meat quality, and nitrogen metabolism of pigs. Twenty-six pregnant Bama mini-pigs and then 104 weaned piglets were assigned for experimental treatments. The plasma and muscle samples were collected at 65-, 95-, and 125-d-old pigs, respectively. The results showed that betaine addition in the sow-offspring diets increased the lean meat rate in the 65-d-old pigs, whereas carcass weight, carcass yield, and loin-eye area were increased in the 95-d-old pigs, and carcass weight and backfat thickness in the 125-d-old pigs. Dietary betaine addition in the sow-offspring diets increased the contents of plasma Asp of 65-d-old, Met of 95- and 125-d-old, and Sar of 125-d-old pigs. Moreover, betaine addition increased the contents of Met, His, Ile, and Phe in Longissimus thoracis et lumborum, whereas those contents were decreased in biceps femoris and psoas major muscles at different stages. Betaine addition in the sow and piglets' diets regulated the muscle fiber-type and myogenic regulatory gene expressions. In summary, betaine addition in the sow and sow-offspring diets could improve the carcass traits and meat quality by altering the plasma biochemical parameters, amino acid composition, and gene expressions of skeletal muscle.

4.
Food Funct ; 12(13): 5837-5849, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34018533

RESUMO

The present study was conducted to investigate the effects of dietary supplementation with Bacillus subtilis (BS) and xylo-oligosaccharides (XOS) on growth performance, intestinal morphology, intestinal microbial community, and metabolites of weaned piglets. One hundred and twenty-eight piglets were randomly allocated to one of four groups, including a control group (basal diet), BS group (basal diet + 500 g t-1 BS), XOS group (basal diet + 250 g t-1 XOS), and BS + XOS group (basal diet + 500 g t-1 BS + 250 g t-1 XOS). Dietary BS and XOS were mixed with the basal diet. All groups had eight replicates with four piglets per replicate. The experiment lasted for 42 days. The results showed that dietary XOS supplementation increased the ADFI and ADG, while decreasing the F/G. Dietary BS or XOS supplementation improved the intestinal morphology of weaned piglets by increasing the villus height and the ratio of villus height to crypt depth in the ileum. In addition, dietary XOS supplementation increased the concentrations of butyrate in the ileum and tryptamine and spermidine in the colon, while decreasing the concentration of indole in the colon compared with the control group. Dietary BS supplementation increased the colonic concentrations of butyrate, tryptamine, and cadaverine, while decreasing the concentration of skatole compared with the control group. The LEfSe analysis identified 16 biomarkers in the ileum of the BS group. The intestinal microbiota alterations of weaned piglets indicated that dietary BS or XOS supplementation could improve intestinal health by increasing the gut microbial diversity and altering the relative abundances of different bacterial species. Moreover, Spearman's correlation analysis revealed the potential link between gut microbiota alterations and metabolite changes of weaned piglets. These findings suggest that dietary XOS supplementation could alone improve the growth performance, while dietary BS or XOS and BS with XOS supplementation could influence intestinal health by altering the intestinal morphology, microbial community, and metabolites of weaned piglets. Meanwhile, there were interactions between BS and XOS in intestinal metabolites.


Assuntos
Bacillus subtilis/fisiologia , Suplementos Nutricionais , Microbioma Gastrointestinal/fisiologia , Oligossacarídeos/metabolismo , Ração Animal , Animais , Dieta , Duodeno/metabolismo , Íleo/metabolismo , Masculino , Suínos , Desmame
5.
Front Nutr ; 8: 779171, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35004811

RESUMO

The present study evaluated the effects of betaine addition in sow and piglet's diets on growth performance, plasma hormone, and lipid metabolism of Bama mini-pigs. A total of 26 pregnant Bama mini-pigs and 104 weaned piglets were selected and divided into different dietary treatment groups (details in "Materials and Methods"). Blood and muscle samples were collected at 65-, 95-, and 125-day-old, respectively. The results showed that betaine addition in sow-offspring diets increased (P < 0.05) the body weight at 125-day-old, average daily gain from 35- to 65-day-old, and average daily feed intake at 35-65 and 35-95 days old of pigs compared with the control group. Betaine addition in sow-offspring diets increased (P < 0.05) the plasma gastrin level at 95-day-old, while betaine addition in sow diets decreased (P < 0.05) the plasma peptide YY and leptin levels at 65-day-old pigs. In the longissimus dorsi muscle of pigs, betaine addition in sow and sow-offspring diets increased (P < 0.05) the C12:0 content at 65-day-old while decreased at 95-day-old. Moreover, betaine addition in sow-offspring diets increased the C24:0 content and decreased the C18:1n9t content at 125-day-old (P < 0.05). In the biceps femoris muscle, the contents of C12:0 at 65-day-old and C20:4n6 at 125-day-old were decreased (P < 0.05) after the betaine addition in both sow and piglet's diets. In addition, betaine addition in sow diets decreased (P < 0.05) the C20:0 content at 125-day-old, while betaine addition in sow-offspring diets increased the C18:3n6 and decreased C24:0 contents at 65-day-old pigs (P < 0.05). In the psoas major muscle, betaine addition in sow and sow-offspring diets decreased (P < 0.05) the contents of C18:1n9t at 65-day-old and C20:1 at 95-day-old, while betaine addition in sow diets decreased (P < 0.05) the intramuscular fat content at 125-day-old. Moreover, betaine addition in sow-offspring diets was also associated with muscle lipid deposition and metabolisms by regulating the gene expressions related to fatty acid metabolism. These findings suggested that betaine addition in sow-offspring diets could improve the growth performance, whereas betaine addition in both sow and sow-offspring diets could enhance lipid quality by altering plasma hormone level and fatty acid composition and regulating the gene expressions related to fatty acid metabolism.

6.
Front Vet Sci ; 7: 575685, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33330695

RESUMO

Nutrients in the maternal diet favor the growth and development of suckling piglets and alter their gut microbiota composition and metabolic activity, thus affecting the hosts. The present study analyzed, in suckling piglets from sows receiving antibiotic or synbiotic supplements from pregnancy to lactation, several biochemical parameters, oxidative/anti-oxidative indices, inflammatory cytokines, and ingestion-related factor levels in plasma, as well as colonic microbiota composition and metabolic activity, and mucosal expression of genes related to the intestinal barrier function. Compared with the control group, maternal synbiotic supplementation decreased (P < 0.05) the plasma levels of glucose, AMM, TC, low-density lipoprotein-cholesterol (LDL-C), MDA, H2O2, ghrelin, CCK, PP, IL-1ß, IL-2, IL-6, TNF-α, Ala, Cys, Tau, and ß-AiBA, the levels of propionate and total short-chain fatty acids (SCFAs) in the colonic luminal content, and colonic abundances of RFN20, Anaerostipes, and Butyricimonas; while increased (P < 0.05) the plasma levels of urea nitrogen (UN), Ile, Leu, α-AAA, α-ABA, and 1-Mehis, as well as colonic abundances of Sphingomonas, Anaerovorax, Sharpea, and Butyricicoccus. Compared with the antibiotic group, maternal synbiotic supplementation decreased (P < 0.05) the plasma levels of glucose, gastrin, and Ala, as well as abundances of Pasteurella and RFN20 and propionate level in the colonic content. Expression of genes coding for E-cadherin, Occludin, ZO-1, ZO-2, IL-10, and interferon-α were down-regulated in the colonic mucosa. The synbiotic supplementation increased (P < 0.05) the plasma levels of UN, Leu, α-ABA, and 1-Mehis, the abundances of Anaerovorax, Sharpea, and Butyricicoccus and expression of genes coding for E-cadherin, Occludin, ZO-1, ZO-2, IL-10, and interferon-α. Spearman correlation analysis showed that there was a positive correlation between colonic Anaerostipes abundance and acetate and SCFAs levels; whereas a negative correlation between Fusobacteria and Fusobacterium abundances and acetate level. These findings suggest that synbiotic supplementation in the maternal diet improved nutrient metabolism and intestinal barrier permeability, reduced oxidative stress, and modified colonic microbiota composition and metabolic activity in suckling piglets.

7.
Mediators Inflamm ; 2020: 8829072, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33162832

RESUMO

This study was conducted to analyze plasma reproductive hormone and biochemical parameter changes, as well as fecal microbiota composition and metabolites in sows, at different pregnancy and lactation stages, using Bama mini pig as an experimental animal model. We found that plasma prolactin (PRL), progesterone, follicle-stimulating hormone (FSH), and estrogen levels decreased from day 45 to day 105 of pregnancy. Plasma total protein and albumin levels were lower in pregnant sows, while glucose, urea nitrogen, total cholesterol, and high-density lipoprotein-cholesterol, as well as fecal acetate, butyrate, valerate, total short-chain fatty acids, skatole, and tyramine levels, were higher in lactating sows. Interestingly, the lactating sows showed lower α-diversity and Spirochaetes and Verrucomicrobia relative abundances, while pregnant sows showed a higher Proteobacteria relative abundance. Notably, the Akkermansia relative abundance was highest on day 7 of lactation. Spearman analysis showed a positive correlation between plasma triglyceride and cholinesterase levels and Akkermansia and Streptococcus relative abundances. Moreover, Oscillospira and Desulfovibrio relative abundances were also positively correlated with plasma FSH, LH, and E2 levels, as well as PRL and LH with Bacteroides. Collectively, plasma reproductive hormones, biochemical parameters, and fecal microbiota composition and metabolite levels could alter along with pregnancy and lactation, which might contribute to the growth and development demands of fetuses and newborns.


Assuntos
Fezes/microbiologia , Lactação , Microbiota , Akkermansia , Albuminas/biossíntese , Animais , Bacteroides , Proteínas Sanguíneas/análise , Clostridiales , Desulfovibrio , Estrogênios/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Gravidez , Prenhez , Progesterona/sangue , Prolactina/sangue , Proteobactérias , Spirochaetales , Streptococcus , Suínos , Porco Miniatura , Verrucomicrobia
8.
Eur J Med Res ; 24(1): 39, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882018

RESUMO

BACKGROUND: Intertrochanteric fracture is a common fracture suffered by elderly patients. Total hip arthroplasty (THA) is regarded as a salvage operation to restore hip joint function after fixation failure, which remains somewhat controversial due to some clinical potential issues. METHODS: 18 elderly patients (average age 70.3 years) each with intertrochanteric fracture fixation failure treated with THA between September 2013 and October 2016 were retrospectively analyzed. Internal fixation treatments involved 5 patients who had received proximal femoral nail anti-rotation, 7 who received locking proximal femur plates and 6 who received dynamic hip screws. All patients were treated with THA using biological acetabular prosthesis and hip arthroplasty (HA) coating skillet femoral prosthesis, with the greater trochanter fixed using wire or steel when necessary. Patients' Harris scores pre- and post-treatment, SF-36 Health Questionnaire score and digital radiology (DR) were used for joint prostheses initial stability and survival evaluation. RESULTS: 15 patients completed follow-up periods ranging between 19 and 54 months (mean 26.2 months; 1 patient died from a pulmonary embolism, 1 patient died from pulmonary heart disease 1 year after surgery and 1 patient withdrew for personal reasons). There were no joint infections, periprosthetic fractures or dislocations. The average Harris score increased significantly, from 32.68 ± 12.04 points before surgery to 91.08 ± 5.9 points at 24 months post-treatment. SF-36 scores were significantly increased. CONCLUSION: THA as salvage treatment for failed internal fixation of intertrochanteric femoral fractures in elderly patients significantly reduced hip pain and restored joint function, and early clinical outcomes were satisfactory.


Assuntos
Artroplastia de Quadril/métodos , Pinos Ortopédicos , Fixação Interna de Fraturas/métodos , Fraturas do Quadril/cirurgia , Prótese de Quadril/estatística & dados numéricos , Recuperação de Função Fisiológica , Idoso , Artroplastia de Quadril/reabilitação , Feminino , Fêmur/cirurgia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Prótese , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
9.
Opt Express ; 27(5): 7023-7035, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30876275

RESUMO

For complex amplitude modulation (CAM)-based three-dimensional (3D) near-eye systems, it is a challenge to realize colorful 3D display by using spatial light modulator (SLM) and grating. Here, a full-color compact 3D see-through near-eye display (NED) system by CAM is proposed. Computer generated holograms (CGHs) for different wavelengths are calculated separately. Each CGH contains two position-shifted sub-holograms and the separated distance is carefully calibrated to eliminate chromatic aberration. Colorful 3D images are synthesized through time-multiplexing. Color managements are performed and chromatic aberration of the system is analyzed to provide better colorful effect. The system structure is integrated to be compact and a prototype is implemented. Pre-compensation is added on CGHs to offset the system's assembling errors. Optical experiment results show that the proposed system can provide good 3D full-color see-through performance without vergence-accommodation conflict (VAC). Dynamic colorful display ability is also tested, which shows good potential for interactive NED in the future.

10.
Opt Express ; 26(17): 22284-22295, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-30130923

RESUMO

Formulas of partially spatial coherent light are derived and its corresponding design algorithm is proposed for generating computer-generated holograms based on partially spatial coherent light. The partially coherent light is divided into two terms: spatially absolute coherent part and incoherent part. The former is propagated by angular spectrum method, while the latter is based on the optical transfer function. The related formulas are derived where the coherent function (degree of coherence) is related. A modified iterative algorithm is further developed for optimizing the phase distributions. Numerical simulations and optical experiments are both performed to verify the proposed algorithm. The results obtained by the proposed method and the traditional method are compared, and it is clear that the speckle contrasts in optical experiments are improved more than 46%, and the image quality is obviously improved. This method could also provide new applications for three-dimensional holographic display, beam shaping, and other wave-front modulation techniques.

11.
Opt Express ; 26(13): 16063-16073, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-30119443

RESUMO

The huge computational complexity is a challenge for computer-generated hologram (CGH) calculation in a holographic display. In this paper, we propose a symmetric compressed look-up-table algorithm to accelerate CGH computation based on the Fresnel diffraction theory and compressed look-up-table algorithm. In offline computation, the memory usage of horizontal and vertical modulation factors is reduced to the order of Kilobytes by using translational symmetric compression and wavelength separation. In online computation, we develop a one-time generation of color holograms method which is accelerated by matrix convolution operation. Numerical simulation results show at least 13 times faster than existing algorithms without sacrificing the computation precision. The optical experiments are performed to demonstrate its feasibility. It is believed that the proposed method is an effective algorithm to accelerate the computation of CGH in color holographic display.

12.
Opt Express ; 26(24): 31995-32006, 2018 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-30650778

RESUMO

In this paper, we propose a visual-cryptographic image hiding method based on visual cryptography (VC) and volume grating optics. The secret image is converted to the encrypted visual keys (VKs) according to the normal VC algorithm. Then the VKs are further embellished to the QR-code-like appearance and hidden as the holographic optical elements (HOEs), which are fabricated by the holographic exposure of photopolymer. In the decryption process, the fabricated HOE-VKs are illuminated with the laser beam. The reconstructed VKs are overlaid to extract the hidden information directly in the optical facility, without additional computation. Optical experiments verify that the VKs in HOE mode improves the system with high security and good robustness on the random noise attack. Besides, the volume grating nature also enlarges the system bandwidth by using the multiplexing technique. The proposed method may provide a promising potential for the practical image hiding systems.

13.
Opt Express ; 25(24): 30061-30072, 2017 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-29221041

RESUMO

A non-iterative design and precise fabrication method of diffractive optical elements (DOEs) on multiple freeform surfaces is proposed and investigated in this paper. Complex amplitude modulation (CAM) technology is applied to design complicated DOEs. The wave-front for desired DOEs fabrication is interfered with a plane wave and then be encoded to a pure phase hologram. Simulations for different DOEs (binary and gray scales) on freeform surfaces are performed and the relative errors are 0.56% and 0.78%, respectively. Since the reconstructed optical fields generated by spatial light modulator (SLM) can be recorded into light-sensitive materials (photopolymer), the DOEs fabrication is realized by optical exposure. The results show that the proposed method can design and fabricate DOEs on multi-freeform surfaces at one time with high quality. Since the CAM method ensures precise reconstruction without iterations, the fabrication is accurate as well as the design is fast. It is expected that the proposed method could be applied in the precise 3D optical fabrication and processing in the future.

14.
Appl Opt ; 56(22): 6168-6174, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29047810

RESUMO

The liquid crystal spatial light modulator (SLM) is able to provide flexible wavefront control, whereas the initial phase and its response distortions will heavily influence the modulation accuracy. The currently existing calibration methods are tedious and time consuming. A novel multi-region calibration method for minimizing those distortions is proposed. The entire panel is divided into several local regions based on the similarity of phase response characteristic. The nonlinear phase response and static phase distortion of each local region are calibrated in the iterative division procedure. The calibration method is theoretically analyzed and experimentally verified. For the Jasper 4 K SLM panel, when five local regions are built, the root mean error of linear phase shifts is reduced to 0.1 rad and the compensation accuracy of the static phase distortion reaches 0.24 wavelength. The calibrated SLM is applied for the color holographic display and the results show that the reconstructed image quality is improved significantly. The proposed method is simpler and faster because of the reasonable regional division and lower calibration complexity. It could be used for the calibration of various phase only or complex modulators with high space bandwidth product in the future.

15.
Opt Express ; 25(7): 8412-8424, 2017 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-28380953

RESUMO

A compact see-through three-dimensional head-mounted display (3D-HMD) is proposed and investigated in this paper. Two phase holograms are analytically extracted from the object wavefront and uploaded on different zones of the spatial light modulator (SLM). A holographic grating is further used as the frequency filter to couple the separated holograms together for wavefront modulation. The developed preliminary prototype has a simple optical facility and a compact structure (133.8mm × 40.4mm × 35.4mm with a 47.7mm length viewing accessory). Optical experiments demonstrated that the proposed system can present 3D images to the human eye with full depth cues. Therefore, it is free of the accommodation-vergence conflict and visual fatigue problem. The dynamic display ability is also tested in the experiments, which provides a promising potential for the true 3D interactive display.

16.
Opt Express ; 24(15): 17372-83, 2016 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-27464184

RESUMO

The complex amplitude modulation (CAM) technique is applied to the design of the monocular three-dimensional see-through head-mounted display (3D-STHMD) for the first time. Two amplitude holograms are obtained by analytically dividing the wavefront of the 3D object to the real and the imaginary distributions, and then double amplitude-only spatial light modulators (A-SLMs) are employed to reconstruct the 3D images in real-time. Since the CAM technique can inherently present true 3D images to the human eye, the designed CAM-STHMD system avoids the accommodation-convergence conflict of the conventional stereoscopic see-through displays. The optical experiments further demonstrated that the proposed system has continuous and wide depth cues, which enables the observer free of eye fatigue problem. The dynamic display ability is also tested in the experiments and the results showed the possibility of true 3D interactive display.

17.
IEEE Trans Neural Netw Learn Syst ; 25(10): 1769-78, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25291732

RESUMO

A wide variety of learning problems can be posed in the framework of convex optimization. Many efficient algorithms have been developed based on solving the induced optimization problems. However, there exists a gap between the theoretically unbeatable convergence rate and the practically efficient learning speed. In this paper, we use the variational inequality (VI) convergence to describe the learning speed. To this end, we avoid the hard concept of regret in online learning and directly discuss the stochastic learning algorithms. We first cast the regularized learning problem as a VI. Then, we present a stochastic version of alternating direction method of multipliers (ADMMs) to solve the induced VI. We define a new VI-criterion to measure the convergence of stochastic algorithms. While the rate of convergence for any iterative algorithms to solve nonsmooth convex optimization problems cannot be better than O(1/√t), the proposed stochastic ADMM (SADMM) is proved to have an O(1/t) VI-convergence rate for the l1-regularized hinge loss problems without strong convexity and smoothness. The derived VI-convergence results also support the viewpoint that the standard online analysis is too loose to analyze the stochastic setting properly. The experiments demonstrate that SADMM has almost the same performance as the state-of-the-art stochastic learning algorithms but its O(1/t) VI-convergence rate is capable of tightly characterizing the real learning speed.


Assuntos
Aprendizagem , Redes Neurais de Computação , Dinâmica não Linear , Processos Estocásticos , Algoritmos , Humanos , Sistemas On-Line
18.
Appl Opt ; 53(21): 4700-7, 2014 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-25090206

RESUMO

The ptychographic scanning operation is introduced into digital holography to expand the field-of-view (FOV). An optical image encryption method based on this technique is further proposed and analyzed. The plaintext is moved sequentially in the way of ptychographic scanning and corresponding pairs of phase-shifted interferograms are recorded as ciphertexts. Then the holographic processing and the ptychographic iterative reconstruction are both employed to retrieve the plaintext. Numerical experiments demonstrate that the proposed system possesses high security level and wide FOV. The proposed method might also be used for other potential applications, such as three-dimensional information encryption and image hiding.

19.
Opt Lett ; 38(9): 1425-7, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23632506

RESUMO

Ptychography is combined with optical image encryption for the first time. Due to the nature of ptychography, not only is the interferometric optical setup that is usually adopted not required any more, but also the encryption for a complex-valued image is achievable. Considering that the probes overlapping with each other is the crucial factor in ptychography, their complex-amplitude functions can serve as a kind of secret keys that lead to the enlarged key space and the enhanced system security. Further, since only introducing the probes into the input of common system is required, it is convenient to combine ptychography with many existing optical image encryption systems for varied security applications.

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