Standardizing catch per unit effort by machine learning techniques in longline fisheries: a case study of bigeye tuna in the Atlantic Ocean

Support vector machine (SVM) is shown to have better performance in catch per unit of effort (CPUE) standardization than other methods. The SVM performance highly relates to its parameters selection and has not been discussed in CPUE standardization. Analyzing the influence of parameter selection on SVM performance for CPUE standardization could improve model construction and performance, and thus provide useful information to stock assessment and management. We applied SVM to standardize longline catch per unit fishing effort of fishery data for bigeye tuna (Thunnus obesus) in the tropical fishing area of Atlantic Ocean and evaluated three parameters optimization methods: a Grid Search method, and two improved hybrid algorithms, namely SVMs in combination with the particle swarm optimization (PSO-SVM), and genetic algorithms (GA-SVM), in order to increase the strength of SVM. The mean absolute error (MAE), mean square error (MSE), three types of correlation coefficients and the normalized mean square error (NMSE) were computed to compare the algorithm performances. The PSO-SVM and GA-SVM algorithms had particularly high performances of indicative values in the training data and dataset, and the performances of PSO-SVM were marginally better than GA-SVM. The Grid search algorithm had best performances of indicative values in testing data. In general, PSO was appropriate to optimize the SVM parameters in CPUE standardization. The standardized CPUE was unstable and low from 2007 to 2011, increased during 2011- 2013, then decreased from 2015 to 2017. The abundance index was lower compared with before 2000 and showed a decreasing trend in recent years

Small RNA zippers lock miRNA molecules and block miRNA function in mammalian cells.

MicroRNAs (miRNAs) loss-of-function phenotypes are mainly induced by chemically modified antisense oligonucleotides. Here we develop an alternative inhibitor for miRNAs, termed \u27small RNA zipper\u27. It is designed to connect miRNA molecules end to end, forming a DNA-RNA duplex through a complementary interaction with high affinity, high specificity and high stability. Two miRNAs, miR-221 and miR-17, are tested in human breast cancer cell lines, demonstrating the 70∼90% knockdown of miRNA levels by 30-50 nM small RNA zippers. The miR-221 zipper shows capability in rescuing the expression of target genes of miR-221 and reversing the oncogenic function of miR-221 in breast cancer cells. In addition, we demonstrate that the miR-221 zipper attenuates doxorubicin resistance with higher efficiency than anti-miR-221 in human breast cancer cells. Taken together, small RNA zippers are a miRNA inhibitor, which can be used to induce miRNA loss-of-function phenotypes and validate miRNA target genes

The Influence of Particle Size of Starch-Sodium Stearate Complex Modified GCC Filler on Paper Physical Strength

Ground calcium carbonate (GCC) was modified with starch/sodium stearate complexes and used to prepare modified GCC of different size by use of a BSJ-200 oscillating sieving machine. Modified GCC was characterized by scanning electron microscopy (SEM) and particle size analysis. Eight kinds of modified GCC of different size and a kind of modified GCC without screening were used in papermaking and the paper strength properties, especially in tensile, tear, and burst index, were investigated. It was found that the size of modified GCC played an important role in the physical properties of the paper. The best size of modified GCC was within the range 35 to 54 µm

Changes in color and iron ions of commercial iron gall inks after artificial aging

Abstract Iron gall inks consist of vitriols (sulphates of certain metals), gall nut extracts; and gum Arabic: after exposure to oxygen, dark-colored compounds of the inks are formed. As the complexity of the composition of iron gall inks renders documents susceptible to environmental influences, this causes the handwriting thereon to fade. These add technical difficulties to the protection of iron gall inks. Therefore, it is particularly important to understand the changes in the inks during the aging process. For this reason, iron gall ink-stained paper specimens were subject to an intense analytical program to investigate their chemical and physical modifications after aging (temperature/humidity, temperature, and ultraviolet light aging), commercial iron gall ink was used for this experiment, making the study more applicable. The changes of iron gall inks were evaluated using color variation, color density, absorbance, and X-ray photoelectron spectroscopy (XPS). All results indicate that the temperature, humidity, and UV are harmful to the inks in both physical and chemical terms. Physical damage is mainly the aging of the ink color lightening, color density decreases, of which the color of the samples treated with damp heat for 30 days undergoes the greatest change. The chemical change is represented by the ratio of the concentration of iron ions in different valence states, the amount of Fe3+ in the untreated inks is much greater than that of Fe2+, and the amount of Fe2+ exceeds that of Fe3+ after exposure to different methods of aging. Experiments show that UV light causes the most severe damage to handwriting. The main manifestation thereof is color-fade and the paper surface ink part of the iron ion content changes, with the increase of aging time, the Fe2+ content gradually increases. This experimental study of the changes produced by iron gall inks during aging can provide better technical support for the protection of the ink handwriting

Improving Fly Ash Whiteness and the Influence of Modified Fly Ash on the Physical Strength of Paper

In order to improve the whiteness of fly ash, the particles were coated by in-situ precipitation of calcium carbonate. After different mass ratios of calcium oxide to fly ash were mixed into water, a certain amount of carbon dioxide was bubbled into the mixture to form a precipitated calcium carbonate deposit on the surface of fly ash. With the help of scanning electron microscopy (SEM), the process and the coating mechanism of the unmodified and modified fly ash were studied. The results showed that when a 1:1 mass ratio of calcium oxide to fly ash was implemented, the whiteness of fly ash was increased from 30.3 (the original fly ash) to 74.0 (the modified fly ash). After appropriately controlling for the rate of carbon dioxide, the whiteness was improved to meet the standard for filler in the papermaking industry, and also great advantages in paper physical strength were demonstrated