Identification of differentially expressed genes and metabolism signaling pathway in the spleen of broilers supplemented with probiotic Bacillus spp

Probiotics are essential in the body's nutrients, improving the ratio of meat to meat, immune response, and preventing diseases. In this study, RNA-sequencing (RNA-seq) was used to identify the differentially expressed genes (DEGs), enriched related pathways, and Gene Ontology (GO) terms among blank negative control (NC), supplemented with Bacillus spp. (BS) and commercial probiotic (PC) groups after a 42-day fed supplementation. The results showed that 2005, 1356, and 2189 DEGs were significantly altered in BS vs. NC, PC vs NC, and BS vs PC groups, respectively. On the other hand, 9 DEGs were further validated by qRT-PCR, indicating that the qRT-PCR and RNA-Seq results were more consistent. Therefore, the GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of DEGs showed that the DEGs were mainly enriched to metabolism signalling pathways (alpha-linolenic acid metabolism, linoleic acid metabolism, tryptophan metabolism, tyrosine metabolism, ether lipid metabolism, and metabolic pathway, etc) and immune response pathways (cytokine-cytokine receptor interaction, MAPK signalling pathway, and intestinal immune network for IgA production, neuroactive ligand-receptor interaction etc). These results will provide a better understanding of the role of probiotics in chicken development and provide basic information on the genetic development of chickens.

Mathematical models to describe the growth curves of Vietnamese Ri chicken

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike's information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Electronic properties of a two-dimensional van der Waals MoGe2N4/MoSi2N4 heterobilayer: effect of the insertion of a graphene layer and interlayer coupling

van der Waals heterostructures (vdWHs) based on 2D layered materials with select properties are paving the way to integration at the atomic scale, and may give rise to new heterostructures exhibiting absolutely novel physics and versatility. Herein, we investigate the structural and contact types in a 2D vdW heterobilayer between MoGe₂N₄ and MoSi₂N₄ monolayers, and the monolayers in the presence of electrical graphene (GR) contact. In the ground state, the MoGe₂N₄/MoSi₂N₄ heterobilayer forms type-II band alignment, which effectively promotes the separation of electrons and holes and provides opportunity for further electrons and holes. Thus, the MoGe₂N₄/MoSi₂N₄ heterobilayer is promising for designing optoelectronic devices with significantly suppressed carrier-recombination. Interestingly, the insertion of the GR contact to a MoGe₂N₄/MoSi₂N₄ heterobilayer gives rise to the formation of a metal/semiconductor contact. Depending on the GR position relative to the MoGe₂N₄/MoSi₂N₄ heterobilayer, the GR-based heterostructure can form either an n-type or p-type Schottky contact. Intriguingly, the contact barriers in the GR contacted MoGe₂N₄/MoSi₂N₄ heterobilayer are significantly smaller than those in the GR contacted with MoGe₂N₄ or MoSi₂N₄ monolayers, suggesting that the GR/MoGe₂N₄/MoSi₂N₄ heterostructure offers an effective pathway to reduce the Schottky barrier, which is highly beneficial for improving the charge injection efficiency of the contact heterostructures. More interestingly, by controlling the interlayer coupling through stacking, both the Schottky barriers and contact types in the GR/MoGe₂N₄/MoSi₂N₄ heterostructure can be manipulated. Our findings could provide theoretical insight into the design of nanodevices based on a GR and MoGe₂N₄/MoSi₂N₄ heterobilayer.

Identifying hotspots for antibiotic resistance emergence and selection, and elucidating pathways to human exposure: Application of a systems-thinking approach to aquaculture systems

Aquaculture systems are highly complex, dynamic and interconnected systems influenced by environmental, biological, cultural, socio-economic and human behavioural factors. Intensification of aquaculture production is likely to drive indiscriminate use of antibiotics to treat or prevent disease and increase productivity, often to compensate for management and husbandry deficiencies. Surveillance or monitoring of antibiotic usage (ABU) and antibiotic resistance (ABR) is often lacking or absent. Consequently, there are knowledge gaps for the risk of ABR emergence and human exposure to ABR in these systems and the wider environment. The aim of this study was to use a systems-thinking approach to map two aquaculture systems in Vietnam - striped catfish and white-leg shrimp - to identify hotspots for emergence and selection of resistance, and human exposure to antibiotics and antibiotic-resistant bacteria. System mapping was conducted by stakeholders at an interdisciplinary workshop in Hanoi, Vietnam during January 2018, and the maps generated were refined until consensus. Thereafter, literature was reviewed to complement and cross-reference information and to validate the final maps. The maps and component interactions with the environment revealed the grow-out phase, where juveniles are cultured to harvest size, to be a key hotspot for emergence of ABR in both systems due to direct and indirect ABU, exposure to water contaminated with antibiotics and antibiotic-resistant bacteria, and duration of this stage. The pathways for human exposure to antibiotics and ABR were characterised as: occupational (on-farm and at different handling points along the value chain), through consumption (bacterial contamination and residues) and by environmental routes. By using systems thinking and mapping by stakeholders to identify hotspots we demonstrate the applicability of an integrated, interdisciplinary approach to characterising ABU in aquaculture. This work provides a foundation to quantify risks at different points, understand interactions between components, and identify stakeholders who can lead and implement change.

Monitoring Antibiotic Use and Residue in Freshwater Aquaculture for Domestic Use in Vietnam

Vietnam is an important producer of aquaculture products, and aquatic products are essential to the Vietnamese diet. However, Vietnam also has very little enforced regulation pertaining to antibiotic usage in domestic aquaculture, which raises concerns for antibiotic resistance in pathogenic bacteria. In this study, analysis was conducted on the presence of antibiotic residues in domestically sold fish and shrimp raised in freshwater farms in Vietnam, and an assessment of farmers' knowledge of proper antibiotics usage was performed. The results indicated that a quarter of tested aquaculture products were antibiotic screening test positive, and there is a general lack of knowledge about the purpose and proper usage of antibiotics by aquaculture producers. Farmers' decision-making processes about antimicrobial use are influenced by biased sources of information, such as drug manufacturers and sellers, and by financial incentives.

Interactions of poly(amino acids) in aqueous solution with charged model surfaces—analysis by colloidal probe

Biomolecules in a confined solution environment may be subject to electrostatic forces with a range up to 100 nm, while van der Waals interaction will account for shorter-range forces. The response of two model poly(amino acids)--poly-L-lysine and poly-L-glutamic acid--has been investigated for a silica/Si-oxide surface at pH 6. The model amino acids were adsorbed, or covalently coupled, to colloidal probes consisting of a microsphere attached to a force-sensing lever. The methodology was based on sensing interaction between the probe and a flat surface through carrying out force versus distance analysis with a scanning force microscope. The results were analyzed within the framework of the conventional DLVO theory. The outcomes illustrate both repulsive and attractive long-range interactions that will hinder, or promote, colloidal biospecies in solution entering the region of attractive short-range interactions at the physical interface. Large 'snap-on' distances were observed for some systems and have been ascribed to compression of the 'soft' functionalized layers. Those observations and measurements of adhesion provided insight into conformation of the adsorbed species and strength of attachment. The results have implications for the efficacy of methods and devices that seek to exploit the properties of micro/nano-fluidic systems.

Atomic force microscopy analysis of wool fibre surfaces in air and under water

Wool fibre surfaces have been treated by solvent cleaning which leaves the native covalently bound surface lipid layer intact, and by alcoholic alkali which removes the lipid layer. The resultant surfaces have been analysed by atomic force microscopy (AFM), with particular emphasis on force-distance (F-d) methods. Methodologies were developed for investigation in situ in water of both the surface topography and the characteristics of the lipid layer. Longitudinal surface texturing was resolved in images of wool fibre surfaces in air; the texturing remained prominent after exposure to water. High resolution F-d curves revealed features associated with the lipid layer. A simple formalism was used to show that the layer had a thickness of a few nm, and an effective stiffness of some 0. 12+/-0.01N/m. Strong adhesive interactions, equivalent to a pressure of 0.1MPa, acted on the tip at the tip-to-substrate interface. The methodology and formalism are likely to be relevant in the broad field of thin-film analysis and for fibre technology.

Platinum Silicide/n-Silicon Photoelectrodes: Properties and Characteristics of the Platinum Silicide Layer

The surface analysis of thermally grown platinum silicide layers on single crystal silicon wafers has shown that silicide phase growth can occur for thin films. The depth profile was found to depend upon the temperature at which the silicide was formed, the length of time for which the reaction proceeded and the supply of platinum. The ESCA peaks for Pt and Si were shifted in energy from the elemental values in the silicide layer. A surface oxide, assigned as SiO2 from the Si 2p signal, was detected on all samples. The platinum signal broadened considerably when the silicide layer had been largely removed by sputtering, and appeared to consist of two components.

Platinum Silicide/n-Silicon Photoelectrodes: Dependence on the Conditions of 'Platinum Silicide' Formation

The photoelectrochemical efficiency and ideality of platinum silicide /n-silicon (1 1 1 ) electrodes were investigated for dependence on silicide growth parameters. A thermal fabrication process was chosen and variation to the following three variables was made individually: the thickness of the deposited platinum, the reaction temperature and the reaction time. The silicide surface layers investigated were PtSi , Pt2Si, and combinations of these compounds, in a single thermally grown product layer. The electrode efficiency was found to be most dependent upon the thickness of the silicide layer, increasing with layer thickness over the range studied, from 5 to 75 nm. Sputtering of the surface with 4 keV argon ions was found to reduce the photoelectrochemical response to a very low level. Solid state photocells could be constructed with efficiencies similar to the photoelectrochemical devices. These cells were also affected by sputtering the surface. For sputtered samples, both in solution and solid state, white light illumination produced a larger photocurrent than a He/ Ne laser. Shining a laser onto the sample when illuminated with white light reduced the photocurrent, indicating that the sputtering altered the silicon near the silicide interface. � Corrosion measurements produced Tafel corrosion rates of a low magnitude, near 10-2 mpy .