Determinants of species assemblages of insect pests in alpine forest ecosystems of western China

Background:Insect pests are a significant threat to natural resources and social development.Modeling species assemblages of insect pests can predict spatiotemporal pest dynamics.However,research gaps remain regarding the mechanism for determining species assemblages of insect pests in alpine forest ecosystems.Here,we explored these determinants using a field investigation conducted for insect pests in a region of the Qinghai-Tibet Plateau.We assessed the species assemblages of insect pests in alpine forest ecosystems based on species co-occurrence patterns and species diversity(i.e.,observed diversity,dark diversity,community completeness,and species pool).A probabilistic model was used to test for statistically significant pairwise patterns of species co-occurrence using the presence-absence matrix of pest species based on species interactions.We used ordinary least squares regression modeling to explore relationships between abiotic factors(i.e.,climate factors and human influence)and species diversity.Results:Positive pest species interactions and many association links can occur widely across different investigation sites and parts of plant hosts in alpine forest ecosystems.We detected high dark diversity and low community completeness of insect pests in alpine forest ecosystems.High temperature and precipitation could promote pest species diversity,particularly dark diversity and species pools.Human influence could drive high levels of pest species diversity and lead to dark diversity and species pools.Community completeness could be an effective indicator for insect pest risk assessment.Conclusions:Our study provides new evidence for the determinants of insect pest species assemblages in alpine forest ecosystems from the perspectives of pest species interactions and abiotic factors.The findings of our study could reveal the mechanism for shaping species assemblages and support the prevention and control of insect pests in alpine forest ecosystems.

Recombinant Apoptin Gene Retrovirus Induces Apoptosis in Human Breast Cancer Cells 435

Objective： To construct recombinant Apoptin gene （vp3） retrovirus pLVP3 and to study its apoptosis inducing effect on human breast cancer cells 435 as well as to discuss its mechanism in vitro and in vivo. Methods： vp3 gene was cloned and recombinated into retrovirus vector pLP-LNCX-VP3 （pLVP3） at loxP site, which was transformed into package cell line PT67 and then into NIH3T3 cells for titer assay. The human breast cancer cell line 435 was infected with retrovirus pLVP3, and then MTT assay and Western blotting were adopted to detect cellular proliferation and Apoptin protein expression. Forty-eight hours after infection flow cytometry （FCM） was used for apoptosis detection and Surface Enhanced Laser Desorption Ionization-Time of Flight-Mass Spectrometry （SELDI-TOF-MS） was used for protein profile assay. Nude mice model of human breast cancer cells 435 was set up to observe the tumor inhibiting rates of pLVP3, and TUNEL assay was used to detect tumor apoptosis as well as real-time PCR for vp3 gene expression. Results： Recombinant plasmid pLVP3 was successfully constructed. Virus titer reached to 5×10^8 pfu/ml in the PT67 culture supernatant. Forty-eight hours after infection, cellular inhibition rate was 65.1% in MTT assay, higher than that in blank control （P〈0.05） and Apoptin protein expressed more in test group in Western blotting. FCM assay showed apoptotic peaks with a percentage of 15.42%. SELDI-TOF-MS findings suggested that two protein peaks, M_2544.1＋H and M_3712.4＋H, were statistically different between infection group and control group （P〈0.05）. The tumor inhibition rates in pLVP3 group were 65.52% and 68.23%, much higher than that of control group （t=4.06, P〈0.01）. TUNEL assay findings showed that positive yellow stains were seen in pLVP3 retrovirus group and 5-FU positive control group without difference （t1=1.05, t2=0.84, P〉0.05）. Conclusion： The experiment demonstrated that vp3 could induce apoptosis in tumor cells in vivo and in vitro, which laid a basis for further study on molecular mechanism of tumor cell apoptosis induced by Apoptin and provided valuable reference for tumor gene therapy.

Coronavirus Disease 2019(COVID-19)vaccines and menstrual cycle length

People all across the world are getting vaccinated against the virus as Coronavirus Disease 2019(COVID-19)spreads.The possibility of adverse reactions to COVID-19 vaccinations has always been a source of concern[1-4].It is also unclear whether COVID-19 immunizations impact female vaccinators’menstrual cycles.Unfortunately,menstrual cycle outcomes were not collected in clinical studies of the current COVID-19 vaccines[1-4].The menstrual cycle of a woman runs from the first day of her menstruation to the first day of her next cycle.Many factors,including nutrition,sleep,and exercise,as well as illness,travel,and stress,are known to influence the length of the menstrual cycle[5].COVID-19 vaccines have caused a variety of side effects in people,including pain at the injection site,nausea,aches,fever,and fatigue.

Changes in Unsaturated Levels of Fatty Acids in Thylakoid PSII Membrane Lipids During Chilling-induced Resistance in Rice

Temperature is one of the abiotic factors limiting growth and productivity of plants. In the present work, the effect of low non-freezing temperature, as an inducer of ＂chilling resistance＂, was studied in three cultivars of rice （Oryza sativa L.）, japonica cv. 9516 （j-9516）, the two parental lines of superhigh-yield hybrid rice between subspecies, Peiai/E32 （ji-PE）, and the traditional indica hybrid rice Shanyou 63 （i-SY63）. Leaves of chill-treated rice showed chilling-induced resistance, as an increase of their low-temperature tolerance was measured using chlorophyll fluorescence measurements, revealing a change in photosystem II （PSII） efficiency. After 5 d of exposure to 11 ~C under low light （100 pmol·m^-2·s^-1）, levels of unsaturated fatty acids in PSII thylakoid membrane lipids decreased during the initial 1-2 d, then increased slowly and reached 99.2%, 95.3% and 90.1% of the initial value （0 d） in j-9516, ji-PE and i-SY63, respectively, on the fifth day. However, under medium light （600 μmol·m^-2·s^-1）, all cultivars experienced similar substantial photoinhibition, which approached steady state levels after a decline in levels of unsaturated fatty acids in PSII thylakoid membrane lipids to about 57.1%, 53.8% and 44.5% of the initial values （0 d） in j-9516, ji-PE and i-SY63 on the fifth day. Under either chilling-induced resistance （the former） or low temperature photoinhibition （the latter） conditions, the changes of other physiological parameters such as D1 protein contents, electron transport activities of PSII （ETA）, Fv/Fm, xanthophyl cycle activities expressed by DES （deepoxide state） were consistent with that of levels of unsaturated fatty acids in PSII thylakoid membrane lipids. So there were negative correlations between saturated levels of fatty acids （16：1（3t）, 16：0, 18：0）, especially the 16：1（3t） fatty acid on thylakoid membrane and other physiological parameters, such as D1 protein contents, ETA and （A＋Z）/（A＋V＋Z）. A specific role of desaturation of fatty acids and the photoprotective pigments of the xanthophyl cycle, leading to an acclimation response in thylakoid membrane lipids may be involved. We conclude that chilling-induced resistance is accelerated by the unsaturation of thylakoid membranes, and the ability of rice plants to cold-harden can be enhanced by genetic engineering.

Preparation of Amino-functionalized Guanidinium Ionic Liquid-Modified Magnetic Materials and Application in Solid-Phase Extraction of Pollutants in Water

In the present work,a novel amino-functionalized hexaalkylguanidinium chloride ionic liquid was prepared and grafted on the surface of magnetic materials through polyethyleneimine to enrich polycyclic aromatic hydrocarbons in water in combination with HPLC equipped with an ultraviolet detector.The effect of several parameters on the extraction efficiency was investigated,including the desorption solvent,the amounts of sorbents,the extraction time,the desorption time and the salt amount.Under the optimized conditions,the method validation exhibited good linearity with correlation coefficients above 0.994 in the range of 0.2-300 ng/mL and low limits of detection and quantification of 0.05 and 0.2 ng/mL,respectively.Besides,relative recoveries were in the range of 80-120%,and the intra-day and inter-day repeatability were good with the relative standard deviations of less than 20%.Finally,the guanidinium ionic liquid modified magnetic materials were applied for the extraction of polycyclic aromatic hydrocarbons from real water samples to demonstrate the utility,and the results show that the proposed method has good prospect for effective enrichment and determination of pollutants in water.