ARTICLE | doi:10.20944/preprints202304.0580.v1
Subject: Biology And Life Sciences, Insect Science Keywords: herbivore-induced plant defense; signaling pathway; intraguild predation; jasmonoyl-isoleucine; abscisic acid
Online: 19 April 2023 (09:31:48 CEST)
The fall armyworm (FAW), Spodoptera frugiperda, has become one of the most important pests on corn in China since it invaded in 2019. Although FAW has not been reported to cause widespread damage to rice plants in China, it has been sporadically found feeding in the field. If FAW infests rice in China, the fitness of other insect pests on rice may be influenced. However, how FAW and other insect pests on rice interact remains unknown. In this study, we found that the infestation of FAW larvae on rice plants prolonged the developmental duration of the brown planthopper (BPH, Nilaparvata lugens (Stål)) eggs, and plants damaged by gravid BPH females did not induce defenses that influenced the growth of FAW larvae. Moreover, co-infestation by FAW larvae on rice plants did not influence the attractiveness of volatiles emitted from BPH-infested plants to Anagrus nilaparvatae, an egg parasitoid of rice planthoppers. FAW larvae were able to prey on BPH eggs laid on rice plants and grew faster compared to those larvae that lacked available eggs. Studies revealed that the delay in development of BPH eggs on FAW-infested plants was probably related to the increase in levels of jasmonoyl-isoleucine, abscisic acid and the defensive compounds in the rice leaf sheaths on which BPH eggs were laid. These findings indicate that if FAW invades rice plants in China, the population density of BPH may be decreased by intraguild predation and induced plant defenses, whereas the population density of FAW may be increased.
ARTICLE | doi:10.20944/preprints202106.0217.v1
Subject: Engineering, Automotive Engineering Keywords: solar collection; solid structure; heat absorption analysis; collection heat analysis; reflection spectrum
Online: 8 June 2021 (12:06:13 CEST)
A solid structure, such as a road, building wall or envelop, used as a solar collector is considered an effective and new way to use renewable energy. This paper focused on the temperature characteristics of four structures exposed to sunshine: asphalt, red brick, composite cement and concrete road slab. Furthermore, the collected heat based on a hydraulic system was investigated experimentally. For the four structure slabs, their temperature differences are due to solar radiation absorption varied greatly by the material’s heat absorptance and color. Through the test, asphalt slab attained the highest temperature and had the weakest reflection among the structures. Compared with the others, the temperature of the asphalt slab was greater by 8.1%, 14.9% and 16.4% than the brick, composite cement and concrete, respectively. The reflection intensity growth ratio was defined and indicates the growth potential for absorbing radiation in the solid slab surface. From the experiments, it was concluded that a suitable selection of road materials can greatly improve the thermal absorption, conduction and penetration into the solid slab. The collected heat capability was approximately 250 W/m2 to 350 W/m2 in the natural summer condition. A black coating or a surface modification can collect more heat, reaching greater than 250 W/m2. The solar collecting heat efficiency with a surface configuration of the road slab can reach above 30% in the summer time.
ARTICLE | doi:10.20944/preprints202310.1919.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: weaning piglet; folic acid; feed efficiency; immune parameter
Online: 30 October 2023 (13:46:25 CET)
In order to study the effects of dietary folic acid (FA) supplementation on growth performance and immune status in weanling piglets, a single factorial randomized block design trial with 6 dietary FA levels at 0.35, 0.66, 2.19, 5.18, 7.51 or 10.81 mg/kg was conducted. A total of 108 crossbred (Landrace × Yorkshire) castrated weanling piglets (at 21 d of age) were allocated by body weight into 36 feeding cages (3 piglets/cage), which were allotted randomly into 6 dietary groups (6 cages/group). Piglets were fed ad libitum for 24 days. Blood samples were collected on the 24th day. The growth performance and the immune parameters were measured. Results showed that FA supplementation increased the serum FA level of weaned piglets (p < 0.01), and tended to increase the body weight (BW) at 45 d of age (p < 0.1) and the average daily gain (ADG) from 29 d to 45 d of age (p < 0.1). FA addition improved the feed efficiency (G/F) from 21 d to 45 d of age (p < 0.01), and with significant effects at 21 d to 45 d of age with FA 2.19 or 7.51 mg/kg (p < 0.05). Dietary FA at 0.66 or 2.19 mg/kg increased the serum CD3+CD8+ subset (p < 0.05), decreased the CD3+CD4+ / CD3+CD8+ ratio (p < 0.05); Moreover, FA addition increased the serum IFN-γ level (p < 0.05). In conclusion, the adequate dietary FA is necessary to improve the immunity and growth performance of weaned piglets at 21 d of age. The suitable dietary FA level for immune function from 21 d to 45 d of age was 0.66 mg/kg, while were 6.82 mg/kg from 21 d to 28 d of age and 5.42 mg/kg from 29 d to 45 d of age respectively for feed efficiency.