The temporal-spatial expression and functional analysis of three gustatory receptor genes in Solenopsis invicta using sweet and bitter compounds.

The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds. During this process, gustatory receptors (GRs) recognize feeding stimulant and deterrent compounds. However, the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant, Solenopsis invicta, remain unknown. Therefore, we conducted a study on the genes SinvGR1, SinvGR32b, and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds. In this current study, we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent. The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds. Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1, SinvGR32b, and SinvGR28a genes were highly expressed in fire ant workers. Tissue-specific expression profiles indicated that SinvGR1, SinvGR32b, and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers, whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae. Furthermore, the silencing of SinvGR1 or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose. The results also showed that SinvGR28a is required for avoiding quinine, as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine. This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds. This study could provide potential target gustatory genes for the control of the fire ant.

Effectiveness of nurse-led multidisciplinary interventions in primary health care: A systematic review and meta-analysis.

AIM: This review aimed to synthesize the available evidence on the effectiveness of nurse-led multidisciplinary interventions in primary health care. METHODS: The following Chinese and English databases were searched for relevant articles: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang and Chinese Biomedical Literature Database (CBM), from the establishment of the databases until the last updating search 1 April 2022. Two researchers screened the studies independently and extracted the data. Meta-analysis was performed using the RevMan 5.3 software. RESULTS: A total of 12 studies were included in this review. It was found that nurse-led multidisciplinary interventions significantly shortened patients' length of stay in hospital (standardized mean differences [SMD] = -1.28, 95%CI: -2.03 to -0.54; P<0.001) and decreased incidences of complications (RR = 0.24, 95%CI:0.10 to 0.54; P = 0.0006) compared to the control group, and lowered patients' anxiety levels (SMD = -1.21, 95%CI: -1.99 to -0.44; P<0.01) and depression levels (SMD = -1.85, 95%CI: -3.42 to -0.28; P<0.0001). Furthermore, the results of subgroup analysis indicated that nurse-led multidisciplinary interventions had significant effects on patients' self-management ability (SMD = 4.45, 95%CI:2.45 to 6.44; P<0.0001) and quality of life (SMD = 1.01, 95%CI: 0.63 to 1.40; P<0.0001) compared to the control group. CONCLUSIONS: Nurse-led multidisciplinary interventions had strong effects in primary health care, contributing to shorten patients' length of stay in hospital, decrease incidences of complications and reduce the levels of anxiety and depression. Moreover, nurse-led multidisciplinary interventions also improved patients' self-management ability and quality of life.

Role of the foraging gene in worker behavioral transition in the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae).

BACKGROUND: Worker division of labor is predominant in social insects. The foraging (for) gene, which encodes cGMP-dependent protein kinase (PKG), has been implicated in the regulation of behavioral transitions in honeybees, but information regarding its function in other social insects is scarce. RESULTS: We investigated the role of the for (Sifor) gene in the red imported fire ant, Solenopsis invicta, and found that Sifor and PKG exhibited different expression patterns in different castes, body sizes, ages and tissues of fire ants, especially in foragers and nurses. Foragers displayed greater locomotor activity but showed no preference for larval or adult odors, whereas nurses showed lesser locomotor activity but had a strong preference for larval odors. We found that the expression of Sifor was significantly higher in the heads of foragers (compared to nurses). RNA interference-mediated Sifor knockdown in foraging workers induced behavioral transition of foragers toward the nurse phenotype characterized by reduced locomotor activity and a stronger preference for larval odors. By contrast, treating nurses with 8-Br-cGMP, an activator of PKG, resulted in behavioral transition toward the forager phenotype characterized by higher locomotor activity but reduced preference for larval odors. CONCLUSION: Our results suggest that Sifor plays a critical role in the behavioral transition between foragers and nurses of workers, which may be a promising target for RNAi-based management of worker caste organization in S. invicta. © 2022 Society of Chemical Industry.

Effects of high-fidelity simulation teaching on nursing students' knowledge, professional skills and clinical ability: A meta-analysis and systematic review.

OBJECTIVE: This meta-analysis was designed to systematically determine the effect of high-fidelity simulation teaching on nursing students' knowledge level, professional skill level and clinical ability. BACKGROUND: High-fidelity simulation is an increasingly popular pedagogical approach in nursing education. It provides students with opportunity to practice in a variety of simulations before entering clinical practice through a variety of real-life situational experiences and many institutions and educators have embraced this method for enhancing access to clinical skills. However, evidence for the effectiveness of the method in nursing teaching remains scarce. DESIGN: A meta-analysis and systematic review. METHODS: The following Chinese and English databases were searched for relevant articles: PubMed, Embase, Cochrane library, Web of Science, CNKI (China National Knowledge Infrastructure) and Wangfang. The search encompassed the establishment of these databases up until November 2021. Two reviewers separately entered the data into Review Manager Software 5.3. RESULTS: A total of 15 studies were included in this study. High-fidelity simulation significantly increased nursing students' knowledge acquisition (SMD = 1. 37, 94％CI:0. 73-2. 00，P ＜0. 0001), enhanced nursing students'professional skills (SMD = 0. 90, 95％CI:0. 36-1. 44，P = 0. 0001). In terms of clinical practice ability outcomes, high-fidelity simulation significantly improved the levels of critical thinking ability (SMD = 0. 58, 95％CI:0. 09-1. 07，P ＜0. 00001), Clinical judgement ability (SMD = 1. 34, 95％CI:0. 38-2. 31，P＝0. 006) and communication skills (SMD = 2. 62, 95％CI:1. 84-3. 40，P ＜0. 001) of nursing students. CONCLUSIONS: We found that high-fidelity simulation have strong educational effects in nursing education, helping nursing students to increase knowledge acquisition, enhance professional skills and cultivate their clinical practice ability (critical thinking ability, communication skills and clinical judgement ability). These findings can provide guidance for nursing educators, indicating that the use of High-fidelity simulation teaching represents an effective solution for transitioning students from the learning environment to clinical practice.

Unraveling the Mode of Action of Cordyceps fumosorosea: Potential Biocontrol Agent against Plutella xylostella (Lepidoptera: Plutellidae).

The entomopathogenic fungus, Cordyceps fumosorosea is a potential eco-friendly biocontrol agent. The present study revealed the entire course of infection of P. xylostella by C. fumosorosea with particular reference to cuticular penetration. Comparative studies on the infection of Plutella xylostella larvae by two strains of C. fumosorosea with different pathogenicity were carried out using light, scanning, and transmission electron microscopy. We found that C. fumosorosea tended to adhere to the cuticle surfaces containing protrusions. Although conidia of the lower pathogenic strain IFCF-D58 germinated, they failed to penetrate and complete the development cycle. In contrast, the higher pathogenic strain IFCF01 began to germinate within 4 h and attached to the cuticle by a thin mucilaginous matrix within 8 h post-inoculation. After 24 h post-inoculation, germ tubes and penetrating hyphae reached the cuticular epidermis and began to enter the haemocoel. Within 36 h post-inoculation, the hyphal bodies colonized the body cavity. Hyphae penetrated from inside to outside of the body after 48 h and sporulated the cadavers. After 72 h post-inoculation, numerous conidia emerged and the mycelial covered the entire cuticular surface. The two strains showed similarities in terms of conidial size and germination rate. However, IFCF-D58 exhibited significantly fewer appressoria and longer penetrating hyphae compared to the more infective IFCF01 on all surface topographies. The current pathogen invasion sequence of events suggested that the aggressive growth and propagation along with rapid and massive in vivo production of blastospores facilitate the conidia of IFCF01 to quickly overcome the diamondback moth's defense mechanism.

Effect of constant and fluctuating temperature on the circadian foraging rhythm of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae).

Understanding circadian foraging rhythms activity of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae) foragers at different temperatures is an important step towards developing control measures in Integrated Pest Management (IPM) programs. In this study, the circadian foraging rhythm activities of S. invicta foragersat different temperature were investigated under laboratory and field conditions. Results indicated that the foraging activity increased after sunrise, and maximum foraging occurred at 14:00 (foraging rate was 69.22 ±â€¯0.57 and 72.58 ±â€¯1.15 foragers/min in the first and second year, respectively) in the tea fields of Guangzhou during autumn. Furthermore, foragers demonstrated circadian rhythms and exhibited a unimodal after 24 h. A significant correlation was found between foraging activity and temperature. S. invicta colonies were active at moderate soil temperatures (approximately 26.65 °C to 29.24 °C). The preferred temperature of the colonies was 26 °C, followed by 22 °C and 18 °C in the laboratory. The individual S. invicta activity was maximum at 17:00 (18.67 ±â€¯1.66 times /10 min) and minimum at 5:00 (8.33 ±â€¯2.51 times/10 min) at 26 °C. The fluctuating temperature had a significant impact on individual locomotor activity (r = 0.8979, P < 0.01) but did not alter the rhythm activity. Our results demonstrated that temperature might play an important role in circadian foraging rhythms activity of S. invicta. These results may have implications for the development of more effective fire ant management strategies.

Evaluating the repellent effect of four botanicals against two Bactrocera species on mangoes.

BACKGROUND: Bactrocera dorsalis and B. correcta are economically important fruit fly pests of crops, vegetables, fruits, and nuts worldwide, especially in China. Nowadays in China, B. correcta is a second notorious pest of many fruits after B. dorsalis. Different botanicals have been tested against the B. dorsalis but in the case of B. correcta, no records were published. METHODOLOGY: This study evaluated the repellency of four botanicals (Seriphidium brevifolium, Piper nigrum, Azadirachta indica and quercetin) in acetone dilutions (5%, 2.5% and 1%) against the B. dorsalis and B. correcta at the laboratory conditions (25 ± 2 °C, 60 ± 5% relative humidity, and a photoperiod of L:D 14:10 h). RESULTS: The number of visits after 24-48 h, oviposition punctures, and pupae made by both species were lower on the treated mangoes in comparison to untreated mangoes. S. brevifolium, P. nigrum, A. indica and quercetin have significantly reduced the visits, ovipositional punctures, and pupae of both species. Among botanicals, the P. nigrum was the most effective repellent against B. correcta and as well as B. dorsalis. However, the harmful effects of these botanicals against natural enemies are still unknown.

Rhythms in Foraging Behavior and Expression Patterns of the Foraging Gene in Solenopsis invicta (Hymenoptera: Formicidae) in relation to Photoperiod.

The foraging gene (for) is associated with foraging and other associated behaviors in social insect species. Photoperiod is known to entrain the rhythmic biological functions of ants; however, how photoperiod might influence the intensity and duration of foraging, and the expression of for, remains unexplored. This study determined the correlation between rhythm in foraging behavior and expression of the foraging gene (Sifor) mRNA in red imported fire ant, Solenopsis invicta Buren. Foragers were exposed to three photoperiod conditions (12:12 [L:D], 24:0 [L:D], and 0:24 [L:D]) in the laboratory and foraging activities were recorded using a video-computer recording system. Sifor expression in the foragers was tested using real-time reverse-transcription quantitative PCR. Results revealed that foraging activity rhythm and Sifor expression profile were unimodal under all three photoperiod conditions. Levels of foraging activity were associated with photoperiodic modification, a stable phase difference between the onset of activity and the onset of gene expression was discovered. Light-dark transients stimulated foraging activity in 12:12 (L:D). There were significant daily oscillations (amplitude of 0.21 ± 0.08 for 12:12 [L:D], 0.12 ± 0.02 for 24:0 [L:D], and 0.09 ± 0.01 for 0:24 [L:D]) in the expression of Sifor. A positive relationship (r = 0.5903, P < 0.01) was found between the expression level of Sifor and foraging activity, which indicated that Sifor is linked to some extent to foraging behavior. Our results demonstrated that foragers could adjust the rhythms in foraging behavior according to light-dark cycle and suggested that Sifor may play an important role in the response of S. invicta to photoperiod.

Gland Origin and Electroantennogram Activity of Volatile Compounds in Ghost Ants, Tapinoma melanocephalum (Hymenoptera: Formicidae) and Behavioral Response to (Z)-9-Nonadecene.

Volatile compounds in Tapinoma melanocephalum (Fabricius) (Hymenoptera: Formicidae, Dolichoderinae) workers were analyzed using gas chromatography-mass spectrometry and electroantennogram responses of workers to these compounds were investigated using coupled gas chromatography-electroantennographic detection. Among 18 detected compounds, six elicited electroantennogram response, including 6-methyl-5-hepten-2-one, 4 iridodials, and (Z)-9-nonadecene. (Z)-9-Nonadecene and iridodials were identified the first time in T. melanocephalum. (Z)-9-Nonadecene is a major component in mandibular glands and iridodials are produced in pygidial glands. In contrast to previous report, actinidine was not found in pygidial glands. Behavioral response of workers to the synthetic (Z)-9-nonadecene was investigated. (Z)-9-nonadecene is an attractant to T. melanocephalum. It also affected their locomotion patterns.

Construction and characterisation of near-isogenic Plutella xylostella (Lepidoptera: Plutellidae) strains resistant to Cry1Ac toxin.

BACKGROUND: Resistance to insecticidal Bacillus thuringiensis (Bt) toxins has arisen in multiple populations of the worldwide Brassica pest Plutella xylostella (L.). To help elucidate the mechanism of resistance to Bt Cry1Ac toxin in a population from Florida, two pairs of near-isogenic lines (NILs) were developed. RESULTS: NILs were generated using either backcross or recombinant inbred line methodologies and evaluated for near-isogenicity with inter-simple-sequence-repeat (ISSR) markers. Backcross line BC6F4 maintained a similar level of Cry1Ac resistance to parental strain DBM1Ac-R (>5000-fold) yet showed 98.24% genetic similarity to the susceptible parental strain DBM1Ac-S. Single-pair backcrosses between DBM1Ac-S and BC6F4 revealed that Cry1Ac resistance was controlled by one recessive autosomal locus. BC6F4 exhibited high levels of cross-resistance to Cry1Ab and Cry1Ah but not to Cry1Ca or Cry1Ie. CONCLUSION: Near-isogenic strains were constructed to provide a reliable biological system to investigate the mechanism of Cry1Ac resistance in P. xylostella. These data suggest that resistance to Cry1Ac, Cry1Ab and Cry1Ah is probably caused by the alteration of a common receptor not recognised by Cry1Ca or Cry1Ie. Understanding Bt toxin cross-resistance provides valuable information to consider when developing pest control strategies to delay resistance evolution. © 2014 Society of Chemical Industry.

Midgut transcriptome response to a Cry toxin in the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae).

To investigate the response of Plutella xylostella transcriptome in defending against a Bt toxin, high-throughput RNA-sequencing was carried out to examine Cry1Ac-susceptible and -resistant strains. The comparative analysis indentified over 2900 differentially expressed unigenes (DEUs) between these two strains. Gene Ontology analysis placed these unigenes primarily into cell, cell part, organelle, binding, catalytic, cellular process, metabolic process, and response to stimulus categories. Based on pathway analyses, DEUs were enriched in oxidoreductase activity and membrane lipid metabolic processes, and they were also significantly enriched in pathways related to the metabolic and biosynthesis of secondary metabolites. Most of the unigenes involved in the metabolic pathway were up-regulated in resistant strains. Within the ABC transporter pathway, majority of the down-regulated unigenes belong to ABCC2 and ABCC10, respectively, while up-regulated unigenes were mainly categorized as ABCG2. Furthermore, two aminopeptidases, and four cadherins encoding genes were significantly elevated as well. This study provides a transcriptome foundation for the identification and functional characterization of genes involved in the Bt resistance in an agriculturally important insect pest, P. xylostella.

Tissue-specific transcriptome profiling of Plutella xylostella third instar larval midgut.

The larval midgut of diamondback moth, Plutella xylostella, is a dynamic tissue that interfaces with a diverse array of physiological and toxicological processes, including nutrient digestion and allocation, xenobiotic detoxification, innate and adaptive immune response, and pathogen defense. Despite its enormous agricultural importance, the genomic resources for P. xylostella are surprisingly scarce. In this study, a Bt resistant P. xylostella strain was subjected to the in-depth transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes in the P. xylostella larval midgut. Using Illumina deep sequencing, we obtained roughly 40 million reads containing approximately 3.6 gigabases of sequence data. De novo assembly generated 63,312 ESTs with an average read length of 416 bp, and approximately half of the P. xylostella sequences (45.4%, 28,768) showed similarity to the non-redundant database in GenBank with a cut-off E-value below 10(-5). Among them, 11,092 unigenes were assigned to one or multiple GO terms and 16,732 unigenes were assigned to 226 specific pathways. In-depth analysis identified genes putatively involved in insecticide resistance, nutrient digestion, and innate immune defense. Besides conventional detoxification enzymes and insecticide targets, novel genes, including 28 chymotrypsins and 53 ABC transporters, have been uncovered in the P. xylostella larval midgut transcriptome; which are potentially linked to the Bt toxicity and resistance. Furthermore, an unexpectedly high number of ESTs, including 46 serpins and 7 lysozymes, were predicted to be involved in the immune defense.As the first tissue-specific transcriptome analysis of P. xylostella, this study sheds light on the molecular understanding of insecticide resistance, especially Bt resistance in an agriculturally important insect pest, and lays the foundation for future functional genomics research. In addition, current sequencing effort greatly enriched the existing P. xylostella EST database, and makes RNAseq a viable option in the future genomic analysis.

Differential fluctuation in virulence and VOC profiles among different cultures of entomopathogenic fungi.

Insect-passaged cultures of entomopathogenic fungi grown on potato dextrose agar media have been shown to have altered virulence and profiles of volatile compounds. The present study demonstrated the pathogenic status of FS(0) (in vitro) and FS(1) and FS(2) (insect-passaged cultures grown on PDA) cultures of Metarhizium anisopliae (strains 406 and 02049) and Beauveria bassiana by a non-choice assay, in which filter paper was inoculated with fungal spores at a concentration of 1 x 10(7) spores/ml. The FS(1) and FS(2) cultures of M. anisopliae strain 02049 and B. bassiana produced conidia with high virulence, and the volatile profiles of these conidia comprised relatively lower percentages of branched-alkanes than conidia from the FS(0) cultures. In contrast, the conidia from an FS(0) culture of M. anisopliae strain 406 had somewhat elevated virulence levels, but their volatile profile had <2% branched-alkanes. The FS(1) and FS(2) cultures of M. anisopliae strain 406 did not gain virulence, and these cultures showed a decline in virulence along with major alteration of their volatile profiles. Their volatile profiles mainly comprised branched-alkanes. The volatile profiles of the FS(1) and FS(2) cultures lacked n-tetradecane, which was an important component of all the virulent cultures. Four compounds, 2-phenylpropenal, 2,5,5-trimethyl-1-hexene, n-tetradecane and 2,6-dimethylheptadecane, were detected only from the virulent cultures, suggesting that low LT(50) values were probably due to the production of these compounds. This is the first report to characterize volatiles from FS(0), FS(1) and FS(2) cultures of entomopathogenic fungi; its utility in different aspects opens an interesting area for further investigations.