924 research outputs found

    Soy flour versus skimmed milk powder in artificial diets for Galleria mellonella, a factitious host for Exorista larvarum

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    Galleria mellonella (L.) (Lepidoptera Pyralidae) is worldwide produced and utilized for different purposes. In the entomology laboratories of the University of Bologna, Italy, this insect has long been maintained in continuous colony, and used as a factitious host for Exorista larvarum (L.) (Diptera Tachinidae), a polyphagous, gregarious larval parasitoid, mainly of Lepidoptera, which lays eggs on the host body. The “standard” diet used to feed G. mellonella larvae, which contains skimmed milk powder, white and whole wheat flour, maize flour, honey, bee wax, brewer’s yeast and glycerine, has long proven to be efficient, but presents the drawback to be rather expensive. We tested the possibility to reduce diet costs by replacing skimmed milk powder (added for its protein and energy intake) with soy flour, an alternative and cheaper protein source. The development times and adult yields of G. mellonella were not negatively affected, when the “soy” diet was used to feed the larvae for one generation. Host acceptance by E. larvarum (measured as number of parasitoid eggs laid on G. mellonella) was higher for the larvae fed on the “soy” than on the “standard” diet. The use of soy flour in lieu of skimmed milk powder, however, proved inappropriate for the rearing of G. mellonella in the long run, because some quality traits, e.g. pupal weights and development times were lower in the “soy” than in the “standard” diet and further worsened through generations. Moreover, the number of eggs laid was dramatically lower for the F2 G. mellonella females obtained on the “soy” than on the “standard” diet. These results suggested that the costs of the artificial diet currently used for G. mellonella may not be lowered by replacing skimmed milk powder with soy flour on a regular basis, possibly due to nutrient imbalance

    Host stage and temperature for the rearing of Aridelus rufotestaceus (Hymenoptera: Braconidae), with notes on acceptance and suitability of 2 stink bug species

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    Nezara viridula (L.) (Hemiptera: Pentatomidae) is a harmful pest of many agricultural crops in different parts of the world. This stink bug is the preferred host species of Aridelus rufotestaceus Tobias (Hymenoptera: Braconidae), an endoparasitoid of nymphs and adults of pentatomids. With the aim to improve the rearing procedure of this beneficial insect, the acceptance and suitability of all mobile stages of N. viridula (from first instar nymph to adult) were evaluated. At 25 & DEG;C, all host stages were accepted and suitable for A. rufotestaceus development, but the highest parasitoid cocoon and adult yields were obtained from second instar nymphs. The possibility to reduce the development time of A. rufotestasceus by increasing the rearing temperature was also evaluated, but 28 & DEG;C proved to be detrimental for parasitoid development, as shown by the very low cocoon and adult numbers obtained. The acceptance and suitability of the invasive pentatomid species Halyomorpha halys (Stal) for A. rufotestaceus was also tested. Female wasps were observed piercing H. halys nymphs with the ovipositor, but no cocoons were obtained, nor were larvae or head capsules detected in the exposed stink bugs

    Coordinated Regulation by AgrA, SarA, and SarR To Control agr Expression in Staphylococcus aureus

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    The agr locus of Staphylococcus aureus is composed of two divergent transcripts (RNAII and RNAIII) driven by the P2 and P3 promoters. The P2-P3 intergenic region comprises the SarA/SarR binding sites and the four AgrA boxes to which AgrA binds. We reported here the role of AgrA, SarA, and SarR on agr P2 and P3 transcription. Using real-time reverse transcription (RT)-PCR and promoter fusion studies with selected single, double, triple, and complemented mutants, we showed that AgrA is indispensable to agr P2 and P3 transcription, whereas SarA activates and SarR represses P2 transcription. In vitro runoff transcription assays revealed that AgrA alone promoted transcription from the agr P2 promoter, with SarA enhancing it and SarR inhibiting agr P2 transcription in the presence of AgrA or with SarA and AgrA. Electrophoretic mobility shift assay (EMSA) analysis disclosed that SarR binds more avidly to the agr promoter than SarA and displaces SarA from the agr promoter. Additionally, SarA and AgrA bend the agr P2 promoter, whereas SarR does not. Collectively, these data indicated that AgrA activates agr P2 and P3 promoters while SarA activates the P2 promoter, presumably via bending of promoter DNA to bring together AgrA dimers to facilitate engagement of RNA polymerase (RNAP) to initiate transcription

    Aedes albopictus Sterile Male Production: Influence of Strains, Larval Diet and Mechanical Sexing Tools

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    The sterile insect technique (SIT) is a biologically based method of pest control, which relies on the mass production, sterilization, and release of sterile males of the target species. Since females can transmit viruses, it is important to develop a mass rearing system to produce a large number of males with a low presence of females. We evaluated the effects of different strains, larval diets and sexing tools on male productivity and residual female presence for the application of SIT against Aedes albopictus. Strains coming from Italy, Germany, Greece, and Montenegro, with different levels of colonization, were reared with three larval diets: IAEA-BY, BLP-B and SLP-BY. Developed pupae were sexed using two different mechanical methods: sieve or Fay-Morlan separator. The results proved that adoption of the Fay-Morlan separator increased the productivity and limited the female presence. The IAEA-BY diet showed the lowest female contamination. Strains with a high number of breeding generations showed a decreased productivity and an increased female presence. Increased female presence was found only in extensively reared strains and only when the sorting operation was conducted with sieves. We hypothesize that extensive colonization may determine a size reduction which limits the sexing tool efficiency itself

    Multiplex SSR-PCR Analysis of Genetic Diversity and Redundancy in the Philippine Rice (Oryza sativa L.) Germplasm Collection

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    Rice germplasm conservation is vital to ensuring the availability of a rich gene pool for future varietal improvement programs. However, with limited resources for gene banking, there is a need to identify and prioritize unique accessions in the PhilRice gene bank for maximum resource utilization. A robust and unequivocal way to identify duplicates is through multiplex SSR-PCR DNA fingerprinting. The present study established the optimal concentrations and reaction conditions for the successful amplification of PCR products using a multiplex panel composed of rice simple sequence repeat (SSR) markers, namely RM312, RM316, RM514 and RM171. The panel was then used to analyze the genetic diversity and identify duplicates among the 427 rice germplasm accessions with similar or identical variety names from the PhilRice genebank. A total of 15 alleles were detected at the 4 SSR loci. The polymorphism information content (PIC) values of the SSR markers were moderately high ranging from 0.459 to 0.643. A dendrogram was constructed using the Dice similarity coefficient and the UPGMA algorithm. The multiplex SSR-PCR panel produced unique profiles of 31 accessions that, being genetically distinct, should be maintained as part of the main collection of the genebank. There were 17 accessions identified as possible redundants having a bootstrap value greater than 95%. Additional SSR and morphological markers will be required to further strengthen the evidence for redundancy, and hence justify removal of unnecessary duplicates from the collection

    Trial of Remote Continuous versus Intermittent NEWS monitoring after major surgery (TRaCINg): protocol for a feasibility randomised controlled trial

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    Background: Despite medical advances, major surgery remains high risk. Up to 44% of patients experience postoperative complications, which can have huge impacts for patients and the healthcare system. Early recognition of postoperative complications is crucial in reducing morbidity and preventing long-term disability. The current standard of care is intermittent manual vital signs monitoring, but new wearable remote monitors offer the benefits of continuous vital signs monitoring without limiting the patient’s mobility. The aim of this study is to evaluate the feasibility, acceptability and clinical impacts of continuous remote monitoring after major surgery. Methods: The study is a randomised, controlled, unblinded, parallel group, feasibility trial. Adult patients undergoing elective major surgery will be invited to participate if they have the capacity to provided informed, written consent and do not have a cardiac pacemaker or an allergy to adhesives. Participants will be randomly assigned to receive continuous remote monitoring and normal National Early Warning Score (NEWS) monitoring (intervention group) or normal NEWS monitoring alone (control group). Continuous remote monitoring will be achieved using the SensiumVitals® wireless patch which is worn on the patient’s chest and monitors heart rate, respiratory rate and temperature continuously and alerts the nurse when there is deviation from pre-set physiological norms. Participants will be followed up throughout their hospital admission and for 30 days after discharge. Feasibility will be assessed by evaluating recruitment rate, adherence to protocol and randomisation, and the amount of missing data. The acceptability of the patch to nursing staff and patients will be assessed using questionnaires and interviews. Clinical outcomes will include time to antibiotics in cases of sepsis, length of hospital stay, number of critical care admissions and rate of readmission within 30 days of discharge. Discussion: Early detection and treatment of complications minimises the need for critical care, improves patient outcomes, and produces significant cost savings for the healthcare system. Remote continuous monitoring systems have the potential to allow earlier detection of complications, but evidence from the literature is mixed. Demonstrating significant benefit over intermittent monitoring to offset the practical and economic implications of continuous monitoring requires well-controlled studies in high-risk populations to demonstrate significant differences in clinical outcomes; this feasibility trial seeks to provide evidence of how best to conduct such a confirmatory trial. Trial registration: This study is listed on the ISRCTN registry with study ID ISRCTN16601772

    Implementing mass rearing of trissolcus japonicus (Hymenoptera: Scelionidae) on cold-stored host eggs

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    Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a pest of Asian origin, has been causing severe damage to Italian agriculture. The application of classical biological control by the release of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an exotic egg parasitoid, appears to be one promising solution. In Italy, releases of T. japonicus in the field were authorized in 2020. In this study, some parameters that could influence the rearing of T. japonicus in insectaries were investigated. A significantly higher production of progeny was observed on host eggs stored at 6◦C (86.5%) compared to −24◦C (48.8%) for up to two months prior to exposure to parasitism. There were no significant differences in progeny production from single females in a vial provided with only one egg mass (83.2%) or 10 females inside a cage with 6 egg masses (83.9%). The exposure of parasitoids to refrigerated (6◦C) egg masses of H. halys for 72 h led to a significantly higher production of progeny (62.1%) compared to shorter exposures for 48 (44.0%) or 24 h (37.1%). A decline in production of progeny by the same female was detected between the first (62.1%) and the second parasitization (41.3%). Adult parasitoids stored at 16◦C for up to 90 days had an 87.1% survival rate, but a significant decrease in progeny production was detected. These parameters could be adjusted when rearing T. japonicus for specific aims such as the production of individuals for field release or colony maintenance

    Efficiency of Three Diets for Larval Development in Mass Rearing Aedes albopictus (Diptera: Culicidae)

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    A fundamental step in establishing a mass production system is the development of a larval diet that promotes high adult performance at a reasonable cost. To identify a suitable larval diet for Aedes albopictus (Skuse), three diets were compared: a standard laboratory diet used at the Centro Agricoltura Ambiente, Italy (CAA) and two diets developed specifically for mosquito mass rearing at the FAO/IAEA Laboratory, Austria. The two IAEA diets, without affecting survival to the pupal stage, resulted in a shorter time to pupation and to emergence when compared with the CAA diet. At 24 h from pupation onset, 50 and 90% of the male pupae produced on the CAA and IAEA diets, respectively, had formed and could be collected. The diet received during the larval stage affected the longevity of adult males with access to water only, with best results observed when using the CAA larval diet. However, similar longevity among diet treatments was observed when males were supplied with sucrose solution. No differences were observed in the effects of larval diet on adult male size or female fecundity and fertility. Considering these results, along with the relative costs of the three diets, the IAEA 2 diet is found to be the preferred choice for mass rearing of Aedes albopictus, particularly if a sugar meal can be given to adult males before release, to ensure their teneral reserves are sufficient for survival, dispersal, and mating in the field

    Patient-reported outcomes of periacetabular osteotomy from the prospective ANCHOR cohort study

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    BACKGROUND: Current literature describing the periacetabular osteotomy (PAO) is mostly limited to retrospective case series. Larger, prospective cohort studies are needed to provide better clinical evidence regarding this procedure. The goals of the current study were to (1) report minimum 2-year patient-reported outcomes (pain, hip function, activity, overall health, and quality of life), (2) investigate preoperative clinical and disease characteristics as predictors of clinical outcomes, and (3) report the rate of early failures and reoperations in patients undergoing contemporary PAO surgery. METHODS: A large, prospective, multicenter cohort of PAO procedures was established, and outcomes at a minimum of 2 years were analyzed. A total of 391 hips were included for analysis (79% of the patients were female, and the average patient age was 25.4 years). Patient-reported outcomes, conversion to total hip replacement, reoperations, and major complications were documented. Variables with a p value of ≤0.10 in the univariate linear regressions were included in the multivariate linear regression. The backward stepwise selection method was used to determine the final risk factors of clinical outcomes. RESULTS: Clinical outcome analysis demonstrated major clinically important improvements in pain, function, quality of life, overall health, and activity level. Increasing age and a body mass index status of overweight or obese were predictive of improved results for certain outcome metrics. Male sex and mild acetabular dysplasia were predictive of lesser improvements in certain outcome measures. Three (0.8%) of the hips underwent early conversion to total hip arthroplasty, 12 (3%) required reoperation, and 26 (7%) experienced a major complication. CONCLUSIONS: This large, prospective cohort study demonstrated the clinical success of contemporary PAO surgery for the treatment of symptomatic acetabular dysplasia. Patient and disease characteristics demonstrated predictive value that should be considered in surgical decision-making. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence
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