Forbedret næringsverdi i fiskefôr med planteproteinfôrmidler ved hjelp av organiske syresalter og faststoff fermentering

The objective of this work was to improve the nutritional value of plant protein sources to be used in fish feed by means of organic acid salts and solid state fermentation (SSF). Four studies were conducted to determine the effects of a blend of organic acid salts (OAB) in diets for rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus), SSF rapeseed meal in different types of diets for Nile tilapia, and thermal-hydro (steam) treatment on nutritional value of fermented rapeseed meal in diets for Nile tilapia. The first study was designed to evaluate the effects of adding an OAB (a mixture of sodium formate and butyrate) to a fish meal-based diet and a diet where 36% of the fish meal protein had been replaced by plant proteins (a mixture of soybean meal and pea protein concentrate). The diets were fed to rainbow trout reared in freshwater. Adding OAB to the plant protein-based diet before extrusion significantly reduced the digestibility of dry matter, organic matter, crude fat, and most amino acids. Supplementation of OAB after extrusion reduced the digestibility of crude fat both in the fishmeal and plant protein-based diets. Inclusion of OAB in both fishmeal and plant protein-based diets before extrusion significantly increased feed conversion ratio (FCR), and middle intestine to body weight ratio. Partly replacing fishmeal with plant proteins reduced the digestibility of dry matter, organic matter, crude fat, phosphorous and several amino acids, and increased FCR. The second study was carried out to determine the potential of laboratory-scale aerobic SSF with Aspergillus niger to increase the nutritional quality of rapeseed meal, and to evaluate the potential for use of untreated (RSM) and fermented rapeseed meal (FRSM) in diets for Nile tilapia. In Exp. 1, three moist diets were produced: a diet based on fish meal and soybean meal (SBM), and two diets in which SBM was fully replaced by RSM or FRSM. In Exp. 2, three extruded diets were produced with the same formulation as used in Exp. 1. Phytic acid and glucosinolates in RSM were reduced, the content of crude protein increased and total amino acids was decreased by SSF. In Exp.1, the growth rate of fish fed the SBM diet was significantly lower than that of tilapias fed the RSM and FRSM diets. FCR of fish fed RSM diet was significantly poorer than that of fish fed the SBM and FRSM diets. Fish fed the RSM diet had significantly higher whole body protein than fish fed the SBM diet. In Exp. 2, the growth rate showed no significant difference among the dietary treatments, while FCR differed among all 3 treatments (SBMMålet med dette arbeidet var å forbedre ernæringsmessig kvalitet av proteinrike fôrmidler fra planter for bruk i fiskefôr ved hjelp av organiske syresalter og faststoff fermentering (SSF). Fire studier ble gjennomført for å undersøke effektene av organiske salter i fôr til regnbueørret (Oncorhynchus mykiss) og niltilapia (Oreochromis niloticus), SSF-behandlet rapsmel i ulike fôr til niltilapia, og fuktig varmebehandling (damp) på den ernæringsmessige verdien av fermentert rapsmel (FRSM) i fôr til niltilapia. Det første studiet ble utført for å evaluere effektene av å sette organiske syresalter (OAB, en blanding av natriumformat og butyrat) til et fiskemelbasert fôr og et fôr hvor 36 % av protein fra fiskemel var erstattet av planteprotein (en blanding av soyamel og erteproteinkonsentrat). Fôrene ble gitt til regnbueørret i ferskvann. Tilsetning av OAB før ekstrudering av fôrene med planteprotein førte til en signifikant reduksjon i fordøyelighet av tørrstoff og organisk materiale, råfett, og de fleste aminosyrene. Tilsetning av OAB etter ekstrudering reduserte fordøyeligheten av råfett både i fôrene med fiskemel og planteprotein. Tilsetning av OAB førte til signifikant høyere fôrforbruk per kg tilvekst, og økt vekt av midttarmen, i prosent av kroppsvekt, både i fôr med fiskemel og planteprotein. Delvis utbytting av fiskemel med planteprotein reduserte fordøyelighet av tørrstoff, organisk materiale, råfett, fosfor og flere aminosyrer, og økte fôrforbruk per kg tilvekst. Det andre studiet ble utført for å bestemme potensialet av laboratorium-skala aerob SSF ved hjelp av Aspergillus niger for å forbedre ernæringsverdien av rapsmel (RSM), og for å evaluere potensialet for bruk av RSM og fermentert rapsmel (FRSM) i fôr til niltilapia. Tre mykfôr ble produsert i forsøk 1: et fôr basert på fiskemel og soyamel (SBM), og to fôr hvor SBM ble helt erstattet med RSM og FRSM. I forsøk 2 ble tre ekstruderte fôr produsert med lik sammensetning som i forsøk 1. Fytinsyre og glukosinolater ble redusert, innholdet av råprotein økte, og det totale innholdet av aminosyrer ble redusert ved SSF. I forsøk 1 var veksthastigheten signifikant lavere hos fisk som fikk fôr med SBM enn hos tilapia som fikk RSM og FRSM i fôret. Fisk som fikk fôr med RSM trengte mer fôr per kg tilvekst enn tilapia som fikk fôr med SBM og FRSM. Fisk som fikk fôr med RSM hadde signifikant høyere innhold av protein i kroppen enn de som fikk fôr med SBM. Det var ingen signifikante forskjeller i veksthastighet i forsøk 2, mens fôropptaket per kg tilvekst var forskjellig for alle tre fôr (SB

Broadband Circularly Polarized Filtering Antennas

This paper consists of two parts. The first part presents a review of the recent development in broadband circularly polarized filtering antennas. The second part presents a novel design of broadband integrated filtering antenna based on eighth-mode SIW (EMSIW) resonators for rectenna applications. This work has three main novel contributions. First, by adjusting the external quality factors and coupling coefficients of the resonators in this filtering antenna, optimum input impedance with a complex value can be realized within the filtering antenna. Thus there is no need for an external impedance matching network, which is usually required between the antenna and the rectifying circuits; Second, compared with traditional microstrip resonators, high-Q EMSIW cavities are used to increase antenna gain; third, the coupling gap between the EMSIW resonators also acts as the feeding structure of the radiator. So the feeding structures are all on the middle layer. The ground plane on the back side is a complete structure without any defects. This novel structure design improves front-to-back ratio to enhance the antenna receiving efficiency. To validate this method, two C-band circularly polarized integrated filtering antennas with an input impedance of 50 $\Omega$ and complex impedance are designed, simulated, and fabricated. The measured results show that the operating frequency bandwidth of the proposed antennas is more than 14.5% at C-band with the gain above 8 dBi. The 3-dB axial ratio bandwidth is larger than 8.5% and the front-to-back ratio is higher than 18 dB. Moreover, the proposed antenna with complex impedance is conjugate matched with the input impedance of a specific rectifying circuit at 5.8 GHz and harmonics suppression at the second-harmonic frequency is achieved

PSR J1926-0652: A Pulsar with Interesting Emission Properties Discovered at FAST

We describe PSR J1926-0652, a pulsar recently discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Using sensitive single-pulse detections from FAST and long-term timing observations from the Parkes 64-m radio telescope, we probed phenomena on both long and short time scales. The FAST observations covered a wide frequency range from 270 to 800 MHz, enabling individual pulses to be studied in detail. The pulsar exhibits at least four profile components, short-term nulling lasting from 4 to 450 pulses, complex subpulse drifting behaviours and intermittency on scales of tens of minutes. While the average band spacing P3 is relatively constant across different bursts and components, significant variations in the separation of adjacent bands are seen, especially near the beginning and end of a burst. Band shapes and slopes are quite variable, especially for the trailing components and for the shorter bursts. We show that for each burst the last detectable pulse prior to emission ceasing has different properties compared to other pulses. These complexities pose challenges for the classic carousel-type models.Comment: 13pages with 12 figure

A Fast Radio Burst Discovered in FAST Drift Scan Survey

We report the discovery of a highly dispersed fast radio burst (FRB), FRB 181123, from an analysis of ~1500 hr of drift scan survey data taken using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulse has three distinct emission components, which vary with frequency across our 1.0–1.5 GHz observing band. We measure the peak flux density to be... (See full abstract in article)

Viral RNA <i>N</i>⁶-methyladenosine modification modulates both innate and adaptive immune responses of human respiratory syncytial virus

Human respiratory syncytial virus (RSV) is the leading cause of respiratory tract infections in humans. A well-known challenge in the development of a live attenuated RSV vaccine is that interferon (IFN)-mediated antiviral responses are strongly suppressed by RSV nonstructural proteins which, in turn, dampens the subsequent adaptive immune responses. Here, we discovered a novel strategy to enhance innate and adaptive immunity to RSV infection. Specifically, we found that recombinant RSVs deficient in viral RNA N6-methyladenosine (m6A) and RSV grown in m6A methyltransferase (METTL3)-knockdown cells induce higher expression of RIG-I, bind more efficiently to RIG-I, and enhance RIG-I ubiquitination and IRF3 phosphorylation compared to wild-type virion RNA, leading to enhanced type I IFN production. Importantly, these m6A-deficient RSV mutants also induce a stronger IFN response in vivo, are significantly attenuated, induce higher neutralizing antibody and T cell immune responses in mice and provide complete protection against RSV challenge in cotton rats. Collectively, our results demonstrate that inhibition of RSV RNA m6A methylation enhances innate immune responses which in turn promote adaptive immunity.</p