The economic impact of Drosophila suzukii: perceived costs and revenue losses of Swiss cherry, plum and grape growers

BACKGROUND

Drosophila suzukii can lead to substantial damages in horticultural production. In this article we analyze revenue losses and cost increases due to D. suzukii as perceived of Swiss cherry, plum and grape growers. Moreover, we investigate associations between farm and grower characteristics and revenue losses and perceived costs increases. We surveyed Swiss growers of cherries, plums and grapes repeatedly in the period 2016-2018 (N = 1572).

RESULTS

We find that 76% of cherry, plum and grape growers faced additional costs due to D. suzukii. In contrast, yield losses due to D. suzukii infestation were small on average, but nevertheless high for some growers. We find substantial heterogeneity in perceived costs and revenue losses across crops, years and farms. Larger farms are found to face lower perceived additional costs, suggesting scale effects in prevention and control of D. suzukii. Growers with a higher inter-varietal diversity perceived additional costs to be higher. Furthermore, organic farming was negatively associated with expected additional costs.

CONCLUSION

Our results suggest that the economic impact of invasive species such as D. suzukii goes far beyond reductions in yield quantity and quality, but rather stems from higher costs due to the need to establish preventive and control measures. Heterogeneity in costs and revenue losses suggests that policy measures to support growers need to be tailored to crops and farm types. Policies supporting improvements of measures against D. suzukii and other newly occurring alien pests and reduce additional costs such as more efficient preventive and control measures merit further encouragement.

Management strategies against Drosophila suzukii: insights into Swiss grape growers choices

BACKGROUND

In 2017, we investigated measures adopted by Swiss grape growers in response to Drosophila suzukii by conducting a survey presenting information obtained from 372 growers on 1708 vineyards.

RESULTS

We found the strategies adopted to be heterogeneous and largely dependent on grape variety (table vs. wine grapes). We identified six clusters of control methods to combat D. suzukii, the most important of which involves using a combination of control methods such as insecticides, mass trapping and sanitation measures, especially pinching of foliage or mowing and mulching. Grape growers in our sample rely primarily on information from public institutions or other growers and the majority plan to continue taking sanitation measures to combat D. suzukii.

CONCLUSION

Our results suggest that strategies adopted in Switzerland differ widely, not only between growers, but also at a vineyard and regional level. Thus, policies and extension services should be targeted (e.g. to varieties and regions) and tailored to types of growers. We find that preventive measures are important when combatting D. suzukii and can reduce post-infestation measures such as pesticide usage. In our sample, biological insecticides, such as kaolin, played a vital role in the control of D. suzukii and merit further support. © 2019 Society of Chemical Industry.

Data on Swiss fruit and wine growers' management strategies against D. suzukii, risk preference and perception

The survey data presented in this article provides information on risk management strategies in response to the invasive pest Drosophila suzukii (spotted wing drosophila) collected among Swiss fruit and wine growers. The survey covered grape, plum, berry and cherry growers and the years 2016, 2017 and 2018. Strategies to prevent or control Drosophila suzukii were collected at the variety level and information on perceived infestation levels as well as harvest losses was collected. In total, nine surveys were conducted, creating a unique panel dataset. Additionally, data was collected with regard to fruit growers’ characteristics (e.g. age, gender) and farm characteristics (e.g. farm size, farm-level workforce, succession, insurance use). Risk preferences were elicited via a self-assessment of risk preferences and (for selected surveys) using a multiple price list. Additionally, (for selected surveys) locus of control and self-efficacy were evaluated via self-assessment questions.

Targeting of the kynurenic acid across the blood-brain barrier by core-shell nanoparticles

Core-shell nanoparticles (CSNPs) were developed to get over therapeutic amount of kynurenic acid (KYNA) across the blood-brain barrier (BBB). Bovine serum albumin (BSA) was used as core for encapsulation of KYNA and the BSA/KYNA composite was finally encapsulated by poly(allylamine) hydrochloride (PAH) polymer as shell. In the interest of the optimization of the synthesis the BSA and KYNA interaction was studied by two-dimensional surface plasmon resonance (SPR) technique as well. The average size of d~100 nm was proven by dynamic light scattering (DLS) and transmission electron microscopy (TEM), while the structure of the composites was characterized by fluorescence (FL) and circular dichroism (CD) spectroscopy. The in vitro release properties of KYNA were investigated by a vertical diffusion cell at 25.0 °C and 37.5 °C and the kinetic of the release were discussed. The penetration capacity of the NPs into the central nervous system (CNS) was tested by an in vitro BBB model. The results demonstrated that the encapsulated KYNA had significantly higher permeability compared to free KYNA molecules. In the neurobiological serial of in vivo experiments the effects of peripherally administered KYNA with CSNPs were studied in comparison with untreated KYNA. These results clearly proved that KYNA in the CSNPs, administrated peripherally is suitable to cross the BBB and to induce electrophysiological effects within the CNS. As the neuroprotective properties of KYNA nowadays are proven, the importance of the results is obvious.

Acetyl-L-carnitine and oxaloacetate in post-treatment against LTP impairment in a rat ischemia model. An in vitro electrophysiological study

A high proportion of research relating to cerebral ischemia focuses on neuroprotection. The application of compounds normally present in the organism is popular, because they do not greatly influence the synaptic activity by receptor modulation, and can be administered without serious side effects. Oxaloacetate (OxAc) and acetyl-L-carnitine (ALC) are such favorable endogenous molecules. ALC can exert a protective effect by improving the energy state of the neurons under ischemic conditions. A promising neuroprotective strategy is glutamate scavenging, which can be achieved by the intravenous administration of OxAc. This study involved the possible protective effects of ALC and OxAc in different post-treatment protocols against long-term potentiation (LTP) impairment. Ischemia was induced in rats by 2-vessel occlusion, which led to a decreased LTP relative to the control group. High-dose (200 mg/kg) ALC or OxAc post-treatment resulted in a higher potentiation relative to the 2VO group, but it did not reach the control level, whereas low-dose ALC (100 mg/kg) in combination with OxAc completely restored the LTP function. Many previous studies have concluded that ALC can be protective only as pretreatment. The strategy described here reveals that ALC can also be neuroprotective when utilized as post-treatment against ischemia.

Neuroprotective effect of oxaloacetate in a focal brain ischemic model in the rat

During an ischemic event, the well-regulated glutamate (Glu) homeostasis is disturbed, which gives rise to extremely high levels of this excitatory neurotransmitter in the brain tissues. It was earlier reported that the administration of oxaloacetate (OxAc) as a Glu scavenger reduces the Glu level in the brain by enhancing the brain-to-blood Glu efflux. Here, we studied the neuroprotective effect of OxAc administration in a new focal ischemic model in rats. Occlusion of the middle cerebral artery resulted in immediate reduction of the somatosensory-evoked responses (SERs), and the amplitudes remained at the reduced level throughout the whole ischemic period. On reperfusion, the SERs started to increase, but never reached the control level. OxAc proved to be protective, since the amplitudes started to recover even during the ischemia, and finally fully regained the control level. The findings of the histological measurements were in accordance with the electrophysiological data. After Fluoro Jade C staining, significantly fewer labeled cells were detected in the OxAc-treated group relative to the control. These results provide new evidence of the neuroprotective effect of OxAc against ischemic injury, which strengthens the likelihood of its future applicability as a novel neuroprotective agent for the treatment of ischemic stroke patients.

Acetyl-L-carnitine normalizes the impaired long-term potentiation and spine density in a rat model of global ischemia

As a consequence of an ischemic episode, energy production is disturbed, leading to neuronal cell death. Despite intensive research, the quest for promising neuroprotective drugs has largely failed, not only because of ineffectiveness, but also because of serious side-effects and dosing difficulties. Acetyl-l-carnitine (ALC) is an essential nutrient which plays a key role in energy metabolism by transporting fatty acids into mitochondria for β-oxidation. It is an endogenous compound and can be used at high dose without toxicity in research into ischemia. Its neuroprotective properties have been reported in many studies, but its potential action on long-term potentiation (LTP) and dendritic spine density has not been described to date. The aim of the present study was an evaluation of the possible protective effect of ALC after ischemic insults inflicted on hippocampal synaptic plasticity in a 2-vessel occlusion (2VO) model in rats. For electrophysiological measurements, LTP was tested on hippocampal slices. The Golgi-Cox staining technique was used to determine spine density. 2VO resulted in a decreased, unstable LTP and a significant loss of dendritic spines. ALC administered after 2VO was not protective, but as pretreatment prior to 2VO it restored LTP nearly to the control level. This finding paralleled the histological analysis: ALC pretreatment resulted in the reappearance of dendritic spines on the CA1 pyramidal cells. Our data demonstrate that ALC administration can restore hippocampal function and spine density. ALC probably acts by enhancing the aerobic metabolic pathway, which is inhibited during and following ischemic attacks.

Post-ischemic treatment with L-kynurenine sulfate exacerbates neuronal damage after transient middle cerebral artery occlusion

Since brain ischemia is one of the leading causes of adult disability and death, neuroprotection of the ischemic brain is of particular importance. Acute neuroprotective strategies usually have the aim of suppressing glutamate excitotoxicity and an excessive N-methyl-d-aspartate (NMDA) receptor function. Clinically tolerated antagonists should antagonize an excessive NMDA receptor function without compromising the normal synaptic function. Kynurenic acid (KYNA) an endogenous metabolite of the tryptophan metabolism, may be an attractive neuroprotectant in this regard. The manipulation of brain KYNA levels was earlier found to effectively enhance the histopathological outcome of experimental ischemic/hypoxic states. The present investigation of the neuroprotective capacity of L-kynurenine sulfate (L-KYNs) administered systemically after reperfusion in a novel distal middle cerebral artery occlusion (dMCAO) model of focal ischemia/reperfusion revealed that in contrast with earlier results, treatment with L-KYNs worsened the histopathological outcome of dMCAO. This contradictory result indicates that post-ischemic treatment with L-KYNs may be harmful.

Fundamental interstrain differences in cortical activity between Wistar and Sprague-Dawley rats during global ischemia

Four-vessel occlusion (4VO), a frequently used model of global cerebral ischemia in rats, results in a dysfunction in wide brain areas, including the cerebral cortex and hippocampus. However, there are pronounced differences in response to global ischemia between the laboratory rat strains used in these studies. In the present work, the immediate acute effects of 4VO-induced global ischemia on the spontaneous electrocorticogram (ECoG) signals were analyzed in Wistar and Sprague-Dawley rats. The ECoG was isoelectric during the 10 min of global cerebral ischemia in Wistar rats and the first burst (FB) was seen 10-13 min after the start of reperfusion. In Sprague-Dawley rats, the FB was detected immediately after the start of 4VO or a few seconds later. The burst suppression ratio (BSR) in Wistar rats decreased to 45% in 5 min after FB, and after 25 min it was approximately 40%. In Sprague-Dawley rats, the BSR was 55% immediately after the FB and it decreased steeply to reach 0% by 10 min. There was also a significant difference between the two strains in the frequency composition of the ECoG pattern. The power spectral densities of the two strains differed virtually throughout the post-ischemic state. The histological results (Evans Blue, Cresyl Violet and Fluoro Jade C stainings) supplemented the electrophysiological data: the neuronal damage in the CA1 pyramids in Wistar rats was severe, whereas in the Sprague-Dawley animals it was only partial. These observations clearly demonstrate that the use of different rat strains (e.g. Wistar vs. Sprague-Dawley) can be a source of considerable variability in the results of acute experiments on global ischemia and it is important that the laboratory rats used in such experiments should be carefully chosen.

Identification of DRB alleles in rhesus monkeys using polymerase chain reaction-sequence-specific primers (PCR-SSP) amplification

Major histocompatibility complex (MHC) class In molecules play a vital role in the regulation of T-cell functions in the mammalian immune system. Two key features characterize the polymorphism of MHC haplotypes in humans and non-human primates: the existence of a large number of alleles, and the high degree of genetic diversity between those alleles. Rhesus monkeys and Chimpanzees have been extensively used as relevant models for human diseases and transplantation We have investigated DRB genes in 19 macaques, members of 3 families, using polymerase chain reaction with sequence-specific primers (PCR-SSP) and denaturing gradient gel electrophoresis (DGGE). After amplification PCR products were purified and subjected direct sequencing. Seven animals (Madison #1) were typed by DDGE also. We report that the DRB haplotypes defined by PCR-SSP exhibit a high degree of concordance with the data obtained by DGGE and direct sequening. Our data show prominent variability in the number of DRB1 alleles ranging from 1-4 per genotype within these families. This analysis demonstrated that most of the amplicons were identical to Mamu-DRB alleles that our PCR primers were to amplify. However, 98-99% similarity was noticed in the case of Mamu-DRB1*0303, Mamu-DRB6*0103 and Mamu-DRB*W201 alleles. The observed mismatches were located in non-polymorphic regions. Thus, family studies in rhesus macaques performed by molecular methods confirmed the multiplicity of Mamu-DRB1 alleles per haplotype and the existence of allelic associations published earlier. In addition, we propose 3 more DRB allele associations (haplotypes): Mamu-DRB1*04-DRB5*03; Mamu-DRB1*04-*DRB*W5; Mamu-DRB1*04*W2. The proposed medium-resolution PCR-SSP technique appears to be a highly reproducible and discriminatory typing method for detecting polymorphisms of DRB genes in rhesus monkeys.

Beta-keratin specific immunological reactivity in feather-like structures of the cretaceous alvarezsaurid, Shuvuuia deserti

We report small fibrous structures associated with a new specimen of Shuvuuia deserti, which we hypothesize are remnants of feather-like epidermal appendages. Multiple analyses suggest that these structures are epidermally derived and contain epitopes consistent with beta-keratin, a protein expressed only in extant "reptiles" and birds. Morphological, microscopic, mass spectrometric, and immunohistochemical studies are consistent with the interpretation that these structures are related to feathers. These data suggest that proteinaceous components may survive across geological time and support the view that alvarezsaurids (Shuvuuia and its allies) are either a lineage of birds or are a lineage phylogenetically close to them. J. Exp. Zool. (Mol. Dev. Evol.) 285:146-157, 1999.

FN18-CRM9 immunotoxin promotes tolerance in primate renal allografts

BACKGROUND

Transplant tolerance, rather than immunity, may be favored in the setting of a lower mature lymphoid mass in the recipient induced by anti-T cell agents. A novel immunosuppressive agent, FN18-CRM9, known to specifically kill T cells with great potency, was evaluated in a transplant model.

METHODS

In order to ablate recipient T cells, the immunotoxin FN18-CRM9 was administered to rhesus monkey recipients of MHC-mismatched renal allografts. Donor lymphocytes were injected intrathymically into some animals.

RESULTS

All monkeys with T-cell depletion by immunotoxin had prolonged allograft survival, and tolerance confirmed by skin grafting has been confirmed in five of six long-surviving recipients.

CONCLUSIONS

In this clinically relevant model, profound but transient T-cell depletion by a single agent substantially promotes tolerance.

From RN to BS: one program's experience with the curriculum revolution

An upper-division nursing program's framework for socialization of the registered nurse to the professional nursing role is presented. Critical thinking is linked to the transformation process, wherein the learner moves from proficiency in technical knowledge to experience that is analyzed and organized by critical thought. The impact on teaching-learning approaches, experience with the Watson-Glaser Critical Thinking Appraisal, and institution of a portfolio system designed to track students' perceptions of changes in critical thinking are discussed.

Keratins as markers of differentiated taste cells of the rat

Cytokeratins in taste buds were immunocytochemically evaluated with monoclonal antibodies. In each of six different epithelial sites in the rat oral cavity, intragemmal cells of taste buds were immunoreactive for keratin polypeptides 8, 18, and 19, as well as for keratin 7, which has not been previously reported in taste buds. Keratin-18-like immunoreactivity was present in fewer than half of the intragemmal cells, whereas all intragemmal cells were immunopositive for keratins 7, 8, and 19. Apart from some salivary duct cells, no other cells in the tongue were immunoreactive for any of these four keratins. Morphological and immunocytochemical profiles indicate that taste buds are islets of simple epithelium embedded in an expanse of stratified squamous epithelium. These simple epithelial cells and their keratins are nerve-dependent, since denervation eliminated all four keratins and replaced elongated taste cells of the vallate papilla with stratified squamous epithelium. We conclude that antibodies against keratins 7, 8, or 19 are useful markers for intragemmal cells in studies of taste bud development, degeneration, regeneration, turnover and tissue culture.

Cell and tissue-specific expression of a heterologous gene under control of the myelin basic protein gene promoter in transgenic mice

Myelin basic protein (MBP) is the second most abundant protein in CNS myelin. We have used transgenic mice to investigate the ability of the 5' flanking sequence of the mouse MBP gene to regulate the cell-type-specific- and temporal expression of a heterologous gene under its control. Transgenic mice were produced with a construct containing the bacterial chloramphenicol acetyltransferase (CAT) gene down-stream of the MBP 5' flanking sequence and CAT expression was monitored both enzymatically and histochemically. The results indicate that 1323 bp of 5' flanking sequence is sufficient to direct CAT expression specifically to the tissue and cell-type, in which MBP is normally synthesized. Additionally, this length of sequence also retains the ability to temporally regulate CAT levels in a manner analogous to endogenous MBP levels.

Comparison of two continuous passive motion protocols for patients with total knee implants

We compared the effects of continuous passive motion (CPM) given for a minimum of 20 hours a day to Group 1 patients (n = 15) or a maximum of 5 hours a day to Group 2 patients (n = 8) who received total knee joint replacements. Four variables were analyzed on the third and sixth days after surgery: 1) range of motion, 2) edema-effusion, 3) pain, and 4) length of hospital stay. We found significant improvements in knee extension (p less [corrected] than .001) in the Group 2 patients on Day 6 after surgery. We also found a significant negative correlation between the length of hospital stay and the number of physical therapy treatments received. No between-group differences were found in measurements of 1) total knee excursion, 2) edema-effusion, 3) pain, 4) length of hospital stay, and 5) number of PT treatments received. This lack of differences implies that comparable results can be obtained by using the CPM machine either 20 hours a day or 5 hours a day.

Brain sites involved in the regulation of growth hormone secretion in the young male domestic fowl

To study brain sites involved in the regulation of GH secretion in the domestic fowl, lesions were placed in and around the hypothalamus of 1-week-old cockerels. Circulating concentrations of GH were then measured at weekly intervals for 4 weeks after the placement of lesions. At the termination of the experiment, histological procedures were used to determine the exact site of the lesion in each bird. Although a fair degree of overlap existed between the lesion sites leading to stimulation and those causing an inhibition of GH secretion, a clear distinction could be made in the overall distribution of stimulatory and inhibitory sites of GH control. A high concentration of lesion sites resulting in GH decline (presumed GH-releasing factor-rich areas) appeared to reside in the general area of the ventromedial and the arcuate nucleus of the hypothalamus. Lesion sites causing a GH rise (presumed somatostatin-rich areas), on the other hand, seemed to have a more caudal distribution. In addition, some evidence of an anterior hypothalamic distribution of these presumed 'somatostatin' neurones was observed. These agree with the existing immunohistochemical data on the distribution of somatostatin and constitute experimental evidence for localization of presumed GH-releasing factor sites within the avian brain.