238 research outputs found

    Black soldier fly as a New chitin source: Extraction, purification and molecular/structural characterization

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    Black Soldier Fly (BSF) represents a potential chitin source that has not been fully explored in terms of characterization, extraction, and purification. In this study, different chemical and enzymatic protocols with or without pre-treatment (ultrasonication and mechanochemical milling) for chitin extraction were tested. Chitin was then accurately quantified and characterized from a molecular and structural point of view by UPLC-MS, XRD, and ESEM, and compared with chitin from shrimp shells. BSF chitin was more recalcitrant than shrimp chitin during extraction and purification, due to the strong binding of chitin to proteins. Indeed, the purity of shrimp chitin was 88.3g/100g of extract, while BSF chitin purity was 47.6–79.9g/100g. Furthermore, the chitin-bound proteins had a defined amino acid composition; their binding was also confirmed by structural characterization. Therefore, the efficiency of each step of the extraction process needs to be critically evaluated to adapt the methods used for crustaceans to insect biomass

    Searching for new predators of the invasive Halyomorpha halys: the role of the black garden ant Lasius niger

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    In recent years, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae, Cappaeini) has become an invasive pest in North America and Europe, where it caused extensive damage to agriculture, resulting in great economic losses. Evaluating the potential of native predators in the invaded areas, ants might represent good candidates thanks to their biology, ecology, and behavior. In Italy, H. halys proved to be the top key pest in pear orchards, where the black garden ant, Lasius niger (L.) (Hymenoptera: Formicidae, Lasiini), is the most abundant ant species. The aim of this study was to evaluate the predatory ability of L. niger on the eggs and on all the juvenile instars of H. halys under laboratory conditions. The results indicate that L. niger significantly reduces the survival of the second and third nymphal instars by 56 and 58%, respectively, but it is unable to reduce the egg hatching and the survival of the first, fourth, and fifth instars. Our preliminary results obtained in laboratory conditions suggest a possible role of the ant L. niger in controlling H. halys invasion mainly acting on the smaller and more mobile nymphal stages. The effective role of this species as potential biocontrol agents of H. halys in fruit orchards in association with other ant species as well as with other predatory insects is discussed

    Does the score on the mrc strength scale reflect instrumented measures of maximal torque and muscle activity in post‐stroke survivors?

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    It remains unknown whether variation of scores on the Medical Research Council (MRC) scale for muscle strength is associated with operator‐independent techniques: dynamometry and surface electromyography (sEMG). This study aimed to evaluate whether the scores of the MRC strength scale are associated with instrumented measures of torque and muscle activity in post-stroke survivors with severe hemiparesis both before and after an intervention. Patients affected by a first ischemic or hemorrhagic stroke within 6 months before enrollment and with complete paresis were included in the study. The pre‐ and post‐treatment assessments included the MRC strength scale, sEMG, and dynamometry assessment of the triceps brachii (TB) and biceps brachii (BB) as measures of maximal elbow extension and flexion torque, respectively. Proprioceptive‐based training was used as a treatment model, which consisted of multidirectional exercises with verbal feedback. Each treatment session lasted 1 h/day, 5 days a week for a total 15 sessions. Nineteen individuals with stroke participated in the study. A significant correlation between outcome measures for the BB (MRC and sEMG p = 0.0177, ϱ = 0.601; MRC and torque p = 0.0001, ϱ = 0.867) and TB (MRC and sEMG p = 0.0026, ϱ = 0.717; MRC and torque p = 0.0001, ϱ = 0.873) were observed post intervention. Regression models revealed a relationship between the MRC score and sEMG and torque measures for both the TB and BB. The results confirmed that variation on the MRC strength scale is associated with variation in sEMG and torque measures, especially post intervention. The regression model showed a causal relationship between MRC scale scores, sEMG, and torque assessments

    Wood impregnated with metal chelates dissolved in organic media tested for termite resistance

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    Wood manufactured products are subjected to biological decay due to fungi and insects. The use of copper chelates as biocides was proposed, due to their high stability which minimizes copper leaching in the environment. Considering the remarkable effectiveness showed by copper chelates on brown rot fungi, zinc and copper chelate complexes were prepared in order to have metal chelates soluble in organic media available. The present study aimed at evaluating these metal chelates complexes as preservative agents for wood treatment against termites. Trials were performed on Reticulitermes lucifugus (Rossi) and Kalotermes flavicollis (Fabricius). Results showed that in both termite species wood consumption was significantly lower on Cu-chelates treated samples compared to untreated wood, whereas the wood slices impregnated with Zn-chelates and the organic media alone gave an intermediate response. Interestingly, in one case solvent-impregnated wood was significantly more attractive than untreated wood for both species and further investigations are being carried out to clarify this behaviour

    Functional changes in the lower extremity after non-immersive virtual reality and physiotherapy following stroke

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    Objective: To analyse the effect of virtual reality (VR) therapy combined with conventional physiotherapy on balance, gait and motor functional disturbances, and to determine whether there is an influence on motor recovery in the subacute (< 6 months) or chronic (> 6 months) phases after stroke. Methods: A total of 59 stroke inpatients (mean age 60.3 years (standard deviation (SD) 14.8); 14.0 months (SD 25.7) post-stroke) were stratified into 2 groups: subacute (n = 31) and chronic (n = 28). Clinical scales (Fugl-Meyer lower extremity (FM LE); Functional Independence Measure (FIM); Berg Balance Scale (BBS); Functional Ambulation Category (FAC); modified Ashworth scale (MAS); 10-metre walk test (10MWT); and kinematic parameters during specific motor tasks in sitting and standing position (speed; time; jerk; spatial error; length) were applied before and after treatment. The VR treatment lasted for 15 sessions, 5 days/week, 1 h/day. Results: The subacute group underwent significant change in all variables, except MAS and length. The chronic group underwent significant improvement in clinical scales, except MAS and kinematics. Motor impairment improved in the severe = 19 FM LE points, moderate 20-28 FM LE points, mild = 29 FM LE points. Neither time since stroke onset nor affected hemisphere differed significantly between groups. The correlations were investigated between the clinical scales and the kinematic parameters of the whole sample. Moreover, FM LE, BBS, MAS, and speed showed high correlations (R2> 0.70) with independent variables. Conclusion: VR therapy combined with conventional physiotherapy can contribute to functional improvement in the subacute and chronic phases after stroke

    Predictive model for the emergence of Xylotrechus arvicola (Coleoptera: Cerambycidae) in La Rioja vineyards (Spain)

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    Xylotrechus arvicola (Coleoptera, Cerambycidae) (Olivier) is a polyphagous borer which attacks different woody species in natural habitats in Spain. This coleopteran is also becoming a real impacting pest in several Spanish wine producing territories. Infested vines show adult exit holes, rachitic shoots, a higher incidence of wood fungal diseases and fragility. At the beginning of the 1990s, a heavy increase of infestation was observed in La Rioja vineyards, the only Qualified Guarantee of Origin Region (A.O.C.) in Spain. Due to the endophytic development of the larvae of X. arvicola, adults are the designated target for the integrated management. Therefore, the aim of the present paper was to study the flight period of the pest and to calculate the value of degree-days for the emergence of both sexes from data collected in the field during 2003-2008 in a Tempranillo cultivar in Tirgo (La Rioja). Adult emergences occurred from the end of May to mid-August and a certain degree of protandry was detected. The predictive models obtained for each year fit a sinusoidal curve in all cases, except for males in 2004, when the adjustment was polynomial. The obtained correlation coefficients were considerably high, as the value 0.99 was exceeded in 72 % of the cases. These results obtained in La Rioja vineyards suggest that control strategies aimed at the reduction of the adult population of X. arvicola in the view of the integrated management, should be performed between mid-June and the end of July.

    Effect of black soldier fly larvae protein on the texture of meat analogues

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    Black soldier fly larvae are considered an alternative source of protein due to their high protein content and low environmental impact of farming. The effect of incorporation of black soldier fly larvae protein (87.6 ± 2.4 g/100 g content) on meat analogues textural characteristics was determined and compared with those of meat analogues prepared with other alternative sources of protein such as soy protein isolate and vital wheat gluten, while beef round, chicken breast, and a commercial plant-based meat analogue were used as reference matrices. Textural characteristics of the experimental meat analogues were used as response variables in robust regression models (R2 > 0.96) built to determine the main effects and interactions of proteins. Black soldier fly larvae protein decreased the textural characteristics of meat analogues as its amount in the formulation increased. The interaction of black soldier fly larvae protein with soy protein affected the hardness and chewiness of meat analogues, whereas the interaction with wheat gluten only affected their cohesiveness. Black soldier fly larvae protein can partially replace traditional proteins in meat analogues. The optimal incorporations of black soldier fly larvae protein in meat analogues which mimics textural characteristics of chicken breast and plant-based meat analogues were 6.7 g/100 g and 21.5 g/100 g, respectively

    Interactions between egg parasitoids and predatory ants for the biocontrol of the invasive brown marmorated stink bug Halyomorpha halys

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    The brown marmorated stink bug Halyomorpha halys is an Asian species that has become a major agricultural pest in North America and Europe. Ants from the genus Crematogaster are predators of H. halys nymphs in Asia, as well as in the Mediterranean, where known native predators are still few. At the same time, ants usually do not harm H. halys eggs, which are the target of the main biological control agents, the scelionid parasitoids of the genus Trissolcus. However, ants, as generalist predators and territorial organisms, may kill or displace a variety of other insects, potentially interfering with parasitoids and biological control programmes. We conducted laboratory experiments to investigate the interactions between the Mediterranean ant Crematogaster scutellaris and the parasitoids T. japonicus and T. mitsukurii, evaluating the possibility that the ants could damage the parasitized eggs, attack the parasitoids during emergence or interfere with the egg-laying behaviour of female parasitoids. Our results demonstrate that C. scutellaris is not able to damage parasitized eggs and is not aggressive towards adult parasitoids at any stage. The presence of ants can slow down the parasitization rate in T. mitsukurii females in the smallest laboratory setups; however, this has not been observed in a more natural setting. We suggest that ants may play a complementary role together with egg-parasitoids in the control of H. halys without interfering with each other

    Resurgence of minor pests following the implementation of mating disruption against Lobesia botrana (Denis & Schiffermüller) (Lepidoptera, Tortricidae) in Sherry vineyards (Spain)

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    The implementation of the mating disruption technique against the grape berry moth, Lobesia botrana (Denis and Schiffermüller) (Lepidoptera, Tortricidae), in Integrated Pest Management (IPM) Sherry vineyards (Andalusia, South-western Spain) reduced the number of chemical treatments required to manage this serious pest. In order to verify the long term consequences of this type of management on the minor pests of vineyards, a study was carried out over nine years to compare the population levels of four phytophagous insect species (Altica ampelophaga, Planococcus citri, Jacobiasca lybica, Aphis gossypii) in plots where L. botrana was managed with conventional chemical treatments or using mating disruption. Field data on secondary pests were collected on randomly chosen vines at different times on different plant organs such as leaves, shoots and bunches, depending on the type of pest, according to the ATRIA procedure (Andalusian IPM procedure). Results showed a significant increase of grapevine infestation by all four secondary pest species in the plots managed with grape berry moth mating disruption. These findings represented a limitation for the implementation of this technique in Andalusian vineyardsWe want to thank J. L. Jiménez García, Academia de San Dionisio de Ciencias, Artes y Letras of Jerez de la Frontera; J. Alcón González, Servicio de Protección de los Vegetales of Jerez de la Frontera and AECOVI JERE
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