Organ biobanking is the pending subject of cryopreservation. Although the problem is multifaceted, advances in recent decades have largely related it to achieving rapid and uniform rewarming of ...cryopreserved samples. This is a physical challenge largely investigated in past in addition to cryoprotectant toxicity studies, which have also shown a great amount of advancement. This paper presents a proof-of-principle, based on the nematode Caenorhabditis elegans, of a technology capable of performing such a function: high intensity focused ultrasound. Thus, avoiding the problem of recrystallization, this worm, in its adult state, preserved at - Formula: see text, has been systematically brought back to life after being heated with High Intensity Focused Ultrasound (HIFU) waves. The great advantage of this technology is that it is scalable; in addition, rewarming can be monitored in real time by MRI thermography and can be controlled by acoustic interferometry. We anticipate that our findings are the starting point for a possible approach to rewarming that can be used for cryopreservation of millimeter scale systems: either alone or in combination with other promising ways of heating, like nanowarming or dielectric heating, the present technology provides new ways of solving the physical aspects of the problem of recrystallization in cryopreservation, opening the door for the long-term storage of larger samples.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Exogenous application of the plant hormone methyl jasmonate (MeJA) can trigger induced plant defenses against herbivores, and has been shown to provide protection against insect herbivory in conifer ...seedlings. Other methods, such as mechanical damage to seedlings, can also induce plant defenses, yet few have been compared to MeJA and most studies lack subsequent herbivory feeding tests. We conducted two lab experiments to: (1) compare the efficacy of MeJA to mechanical damage treatments that could also induce seedling resistance, (2) examine if subsequent insect damage differs depending on the time since induction treatments occurred, and (3) assess if these induction methods affect plant growth. We compared Scots pine (
Pinus sylvestris
) seedlings sprayed with MeJA (10 or 15 mM) to seedlings subjected to four different mechanical bark damage treatments (two different bark wound sizes, needle-piercing damage, root damage) and previous pine weevil (
Hylobius abietis
) damage as a reference treatment. The seedlings were exposed to pine weevils 12 or 32 days after treatments (early and late exposure, hereafter), and resistance was measured as the amount of damage received by plants. At early exposure, seedlings treated with needle-piercing damage received significantly more subsequent pine weevil feeding damage than those treated with MeJA. Seedlings treated with MeJA and needle-piercing damage received 84% less and 250% more pine weevil feeding, respectively, relative to control seedlings. The other treatments did not differ statistically from control or MeJA in terms of subsequent pine weevil damage. For the late exposure group, plants in all induction treatments tended to receive less pine weevil feeding (yet this was not statistically significant) compared to control seedlings. On the other hand, MeJA significantly slowed down seedling growth relative to control and all other induction treatments. Overall, the mechanical damage treatments appeared to have no or variable effects on seedling resistance. One of the treatments, needle-piercing damage, actually increased pine weevil feeding at early exposure. These results therefore suggest that mechanical damage shows little potential as a plant protection measure to reduce feeding by a bark-chewing insect.
Utilizing plants with enhanced resistance traits is gaining interest in plant protection. Two strategies are especially promising for increasing resistance against a forest insect pest, the pine ...weevil (
): exogenous application of the plant defense hormone methyl jasmonate (MeJA), and production of plants through the clonal propagation method somatic embryogenesis (SE). Here, we quantified and compared the separate and combined effects of SE and MeJA on Norway spruce resistance to pine weevil damage. Plants produced via SE (emblings) and nursery seedlings (containerized and bare-root), were treated (or not) with MeJA and exposed to pine weevils in the field (followed for 3 years) and in the lab (with a non-choice experiment). Firstly, we found that SE and MeJA independently decreased pine weevil damage to Norway spruce plants in the field by 32-33% and 53-59%, respectively, compared to untreated containerized and bare-root seedlings. Secondly, SE and MeJA together reduced damage to an even greater extent, with treated emblings receiving 86-87% less damage when compared to either untreated containerized or bare-root seedlings in the field, and by 48% in the lab. Moreover, MeJA-treated emblings experienced 98% lower mortality than untreated containerized seedlings, and this high level of survival was similar to that experienced by treated bare-root seedlings. These positive effects on survival remained for MeJA-treated emblings across the 3-year experimental period. We conclude that SE and MeJA have the potential to work synergistically to improve plants' ability to resist damage, and can thus confer a strong plant protection advantage. The mechanisms underlying these responses merit further examination.
An essential component of plant defense is the change that occurs from a constitutive to an induced state following damage or infection. Exogenous application of the plant hormone methyl jasmonate ...(MeJA) has shown great potential to be used as a defense inducer prior to pest exposure, and could be used as a plant protection measure. Here, we examined (1) the importance of MeJA-mediated induction for Norway spruce (
Picea abies
) resistance against damage by the pine weevil
Hylobius abietis
, which poses a threat to seedling survival, and infection by the spruce bark beetle-associated blue-stain fungus
Endoconidiophora polonica
, (2) genotypic variation in MeJA-induced defense (terpene chemistry), and (3) correlations among resistance to each pest. In a semi-field experiment, we exposed rooted-cuttings from nine different Norway spruce clones to insect damage and fungal infection separately. Plants were treated with 0, 25, or 50 mM MeJA, and planted in blocks where only pine weevils were released, or in a separate block in which plants were fungus-inoculated or not (control group). As measures of resistance, stem area debarked and fungal lesion lengths were assessed, and as a measure of defensive capacity, terpene chemistry was examined. We found that MeJA treatment increased resistance to
H. abietis
and
E. polonica
, but effects varied with clone. Norway spruce clones that exhibited high constitutive resistance did not show large changes in area debarked or lesion length when MeJA-treated, and vice versa. Moreover, insect damage negatively correlated with fungal infection. Clones receiving little pine weevil damage experienced larger lesion lengths, and vice versa, both in the constitutive and induced states. Changes in absolute terpene concentrations occurred with MeJA treatment (but not on proportional terpene concentrations), however, variation in chemistry was mostly explained by differences between clones. We conclude that MeJA can enhance protection against
H. abietis
and
E. polonica
, but the extent of protection will depend on the importance of constitutive and induced resistance for the Norway spruce clone in question. Trade-offs among resistances do not necessarily hinder the use of MeJA, as clones that are constitutively more resistant to either pest, should show greater MeJA-induced resistance against the other.
Somatic embryogenesis (SE), a clonal propagation method utilizing somatic cells, occurs under conditions that activate plant stress adaptation mechanisms such as production of protective secondary ...metabolites. Surprisingly, possible differences in susceptibility to insect pests between SE-generated and conventionally cultivated plants have not been previously explored. Here, we recorded frequencies and levels of bark-feeding damage by pine weevils (
) in two large field trials, consisting of emblings (SE-propagated plants) and seedlings from 50 half-sib Norway spruce (
) families. We found that emblings were less frequently attacked by pine weevils, and when attacked, they were damaged to a lesser extent than seedlings. Moreover, we detected significant additive genetic variation in damage levels received by plants, indicating a heritable component to differences in resistance to insect herbivory among half-sib families. We present first-time evidence that emblings can be more resistant than seedlings to herbivorous insect damage, thus, SE appears to confer a previously unknown plant protection advantage. This finding indicates novel avenues to explore mechanisms underlying plant resistance and new approaches to develop non-toxic measures against insect pests.
Introduction: Low-dose ketamine infusions have shown analgesic effectiveness for the management of postoperative pain. The impact of low-dose ketamine infusions on cardiovascular response is ...dose-dependent and requires a better knowledge about its effects on this population.
Objective: To conduct a systematic review to describe changes in systolic, diastolic and mean arterial pressure, and heart rate 24, 48 and 72 hours after surgery.
Methods: Randomized, controlled trials were reviewed in the Cochrane Library, PubMed, EMBASE, SciELO, Lilacs and grey literature on low-dose ketamine infusions for the study variables. The quality of the studies was assessed using the Cochrane’s risk of bias tool.
Results: Six randomized, controlled trials with 641 patients were included. Low-quality evidence was found suggestive of a lack of certainty of any significant differences in the systolic blood pressure variables at 24 hours (mean standard deviation -1.00, 95 % CI: -7.27 to 5.27). A statistically significant higher mean heart rate at 24 hours was identified in the low-dose ketamine infusion group, (mean standard deviation 1.64 95 % CI: 0.38 to 2.90) which did not reach clinical significance. A lower pain level and less use of opioids was identified in the low-dose ketamine infusion group.
Conclusion: Low quality evidence was found, suggesting that low-dose ketamine infusions are not associated with significant changes in blood pressure or heart rate 24 – 48 hours after surgery. It is important to individualize cardiovascular risk for each case, before initiating treatment.
Introducción: Las infusiones en dosis bajas de ketamina han mostrado eficacia analgésica en el manejo del dolor posoperatorio. El impacto de las infusiones en dosis bajas de ketamina en la respuesta cardiovascular es dosisdependiente y requiere un mejor conocimiento de sus efectos en esta población.
Objetivo: Realizar una revisión sistemática para describir los cambios en la presión arterial sistólica, presión arterial diastólica, presión arterial media, frecuencia cardiaca a las 24, 48 y 72 horas del posoperatorio.
Métodos: Se revisaron ensayos controlados aleatorizados en Cochrane Library, PubMed, EMBASE, SciELO, Lilacs y literatura gris de infusiones en dosis bajas de ketamina para las variables del estudio. La calidad de los estudios se evaluó usando la herramienta de riesgo de sesgos de Cochrane.
Resultados: Se incluyeron seis ensayos controlados aleatorizados con 641 pacientes. Se encontró evidencia de baja calidad sugestiva de ausencia de certeza de diferencias significativas en las variables presión arterial sistólica a las 24 horas (diferencia de medias estandarizada -1,00, IC95 %: -7,27 a 5,27). Para las 24 horas se halló una media de frecuencia cardiaca mayor en el grupo de infusiones en dosis bajas de ketamina, estadísticamente significativa (diferencia de medias estandarizada 1,64 IC95 %: 0,38 a 2,90) sin alcanzar significancia clínica. Se encontró menor nivel de dolor y consumo de opioides en el grupo de infusiones en dosis bajas de ketamina.
Conclusión: Se encontró evidencia de baja calidad, sugestiva de que las infusiones en dosis bajas de ketamina no se asocian a cambios significativos en la presión arterial o frecuencia cardiaca a las 24-48 horas en el posoperatorio. Es importante individualizar el riesgo cardiovascular para cada caso previo al inicio del tratamiento.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The strength of plant‐herbivore interactions varies spatially and through plant ontogeny, which may result in variable selection on plant defense, both among populations and life‐history stages. To ...test whether populations have diverged in herbivore resistance at an early plant stage, we quantified oviposition preference and larval feeding by Plutella xylostella (L.) (Lepidoptera: Plutellidae) on young (5–6 weeks old) Arabidopsis lyrata (L.) O'Kane & Al‐Shehbaz (Brassicaceae) plants, originating from 12 natural populations, six from Sweden and six from Norway. Arabidopsis lyrata can be trichome‐producing or glabrous, with glabrous plants usually receiving more damage from insect herbivores in natural populations. We used the six populations polymorphic for trichome production to test whether resistance against P. xylostella differs between the glabrous and the trichome‐producing morph among young plants. There was considerable variation among populations in the number of eggs received and the proportion of leaf area consumed by P. xylostella, but not between regions (Sweden vs. Norway) or trichome morphs. Rosette size explained a significant portion of the variation in oviposition and larval feeding. The results demonstrate that among‐population variation in resistance to insect herbivory can be detected among very young individuals of the perennial herb A. lyrata. They further suggest that trichome densities are too low at this plant developmental stage to contribute to resistance, and that the observed among‐population variation in resistance is related to differences in other plant traits.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Zoophytophagous (omnivorous) predators provide valuable pest control services, and offer an advantage over strict carnivores as plant-feeding enables survival during prey shortage. This putative ...advantage can potentially be their downside, as plant-feeding may entail damage that negatively affects plant growth/yield (i.e., the cost arising from of omnivore plant-feeding). Yet, benefits conferred by predatory services are usually thought to counterbalance any impact of plant damage. In this systematic review, our goal was to determine how often levels of omnivore damage and its consequences for plants (costs) are considered or quantified. We provide a synthesis of publication trends and findings on omnivore plant-feeding levels, plant injury variables, actual (if quantified) and potential effects on growth/yield, the type of study (lab, greenhouse) and the plants/omnivores most often examined. Our search revealed that measures of omnivore plant-feeding are occasionally reported, but seldom are the direct consequences of such damage also considered. Omnivore plant-feeding were reported in 57% of studies (53 of 93 full-text examined); within these, the majority (>80%) indicated moderate to high levels of plant-feeding. However, only 22% of reports (15 of 69) quantified the effects of omnivore-inflicted damage on plant performance. Of these 15 reports, a greater number found negative consequences for plants compared to those showing no effect (8 vs. 4; 3 with both), with consequences for yield relative to growth being more often evaluated (6 vs. 2). Overall, fruit/leaf injuries relative to stem/flower-feeding were most often examined, and lab/greenhouse experiments predominated. Tomatoes (Solanum lycopersicum) and the mirid Nesidiocoris tenuis were the most common species studied (34 and 14 reports, respectively). Our results indicate that costs to plants of omnivore-inflicted damage are often neglected. We argue that predatory benefits need to be simultaneously considered with plant-feeding effects to appropriately evaluate pest control services. Publication trends suggest that more studies are evaluating costs to plants, but a paradigm shift is still needed. Furthermore, we found that our understanding of plant-feeding and its effects is disproportionally based on studies examining tomato plants and its omnivorous biocontrol agents. To confirm the generality of findings thus far, other plant omnivore systems should be further considered.
•For more than 20 years, methyl jasmonate (MeJA) has been used to study inducible defenses in conifers and to increase tree resistance to pests and pathogens. Despite the numerous studies on the ...subject, no attempts have been made to summarize or quantify how MeJA affects resistance and growth in conifers. Here we present a quantitative meta-analysis of the effects of MeJA treatment on the conifer genera Pinus and Picea, two of the most economically and ecologically important tree genera in boreal, temperate, and alpine forests.•A literature search yielded 120 relevant papers. We summarized the key experimental methods used in these papers and performed a meta-analysis of how MeJA affects tree growth and resistance to pests and pathogens.
•The results show that MeJA negatively affects tree growth, with an overall effect size of −0.63. The overall effect size of MeJA for tree resistance was −0.76, indicating that MeJA treatment significantly reduces tree damage caused by biotic stressors.•Although our meta-analysis shows that MeJA is effective in enhancing conifer defenses, there are still gaps in our understanding of the durability and ecological consequences of MeJA treatment. We provide suggestions for how future research should be conducted to address these gaps.
•Methyl jasmonate has been used for more than 20 years to study conifer inducible defenses.•We summarized the key experimental methods used to study methyl jasmonate effects on conifers.•Meta-analysis showed that methyl jasmonate significantly reduces growth and pest/pathogen damage.•We identified important knowledge gaps that hinder the practical use of methyl jasmonate as a protective measure in forestry.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Predators can decrease herbivore damage to plants, and this is often assumed to be beneficial to plant growth/reproduction without actual quantification. Moreover, previous studies have been biased ...towards strict carnivores and neglected the role of omnivorous predators in prey-suppression. Here, we examined the costs (reduction in growth) and benefits (increase in growth) of enemy-mediated plant protection via the omnivorous (prey and plant-feeding) Orthotylus marginalis, relative to herbivory by a detrimental insect pest of Salix spp. plantations, the beetle Phratora vulgatissima. In a first experiment, we compared the cost of adult beetle versus omnivore nymph plant-feeding, and assessed the (non-) additive effects of the two types of damage. In a second experiment, we quantified the reduction in plant damage resulting from beetleegg feeding by omnivorous nymphs and subsequent benefits to plants. We found that plant-feeding by omnivores negatively affected plant growth and this effect was similar to the cost imposed by beetle herbivory. Furthermore, simultaneous damage effects were additive and more detrimental than individual effects. While egg-predation by omnivore nymphs completely prevented beetle damage to plants, there was no difference in plant growth relative to only herbivore-damaged plants and growth was still reduced compared to control plants. Thus, despite herbivore suppression, there was no benefit to plant growth of omnivore-mediated plant protection and the negative effects of omnivore plant-feeding remained. These results are a first for an omnivorous enemy, and provide novel and timely insights on the underlying assumptions of tri-trophic associations and their use for biocontrol of insect pests.
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