For at least three million years, knapping stone has been practiced by hominin societies large and small, past and present. Thus, understanding knapping, knappers, and knapping cultures is fundamental to anthropological research around the world. Although there is a general sense that stone knapping is inherently dangerous and can lead to injury, little is formally, specifically, or systematically known about the frequency, location, or severity of knapping injuries. Toward this end, we conducted a 31-question survey of modern knappers to better understand knapping risks. Responses from 173 survey participants suggest that knapping injuries are a real and persistent hazard, even though a majority of modern knappers use personal protective equipment. A variety of injuries (lacerations, punctures, aches, etc.) can occur on nearly any part of the body. The severity of injury sustained by some of our participants is shocking, and nearly one-quarter of respondents reported having sought or received professional medical attention for a flintknapping-related injury. Overall, the results of this survey suggest that there would have likely been serious, even fatal, costs to knappers in past societies. Such costs may have encouraged the deployment of any social learning capacities possessed by hominins or delayed the learning or exposure of young infants or children to knapping.

Introduction. Plants developmechanisms that allow them to compartmentalize injuries that theysuffer during their life. In trees, pruning and injection treatmentsmust be used in accordance with precise rules to reduce risks resultingfrom the injuries created. Sealing in palms. Palms,contrary to widespread belief, are quite capable of “healing” injuries(sealing); because of an anatomy quite different from trees, thesealing process in palms is much simpler. Compartmentalizationof injection wounds. The controversy on the use of injectionin trees is due essentially to initial mistakes that have then beenrectified. Injection in palms against the red palm weevil.For palms, for decades, this technique has been employed withoutproblems and with great efficiency against various pests, including Rhynchophorus ferrugineus, the red palm weevil(RPW). Its use has been reserved for exceptional situations eitherto face abnormal pest proliferation, uncontrollable by other techniques,or to implement eradication programs. Integrated eradicationprogram. In such a program, the main aim of injection treatmentsis preventive. With long-persistence insecticides, the number of treatmentscould be greatly reduced. The resulting savings in time and moneywould enable the organization of the treatments of all the palms locatedin an infested area, and consequently the rapid eradication of thepest. New perspectives. We established that insecticidesapplied by injection were capable of protecting palms with onlytwo or even one treatment per year. These results suggest a radicalimprovement in programs to eradicate RPW, while considerably reducingthe risks to health and the environment compared with spray treatments.

Introduction. Bacterial canker,caused by P. syringae pv. syringae,is an important disease of stone fruit worldwide. The possibilityof P. syringae pv. syringae infectionthrough leaf scars and lenticels was evaluated in cherry, peachand prune. Materials and methods. Laboratory and fieldinoculations were performed using cherry, peach and prune stemsto evaluate leaf scar age, chilling and freezing-thawing on bacterialinfection through leaf scars and lenticels. Results and discussion. Increasingleaf scar age was associated with significant decreases in diseaseincidence and length of lesions resulting from leaf scar inoculationwith Pseudomonas syringae pv. syringae incherry, peach and prune. A significant reduction in incidence andlesion length was observed after 4 h of air exposure, and both measuresof infection were reduced to essentially 0 by 2 days of exposure. Prolongedchilling temperature (2.2 °C) prior to leaf removal had no cleareffect on disease incidence of leaf scar infection, but significantlydecreased lesion length due to leaf scar infection. Cherry was more susceptibleto P. syringae pv. syringae infectionthrough leaf scars than peach and ‘French’ prune. The leaf scar inoculationresults were consistent with the previous studies. The disease incidenceof lenticel infection caused by bacterial inoculation in ‘French’prune was very low, but significantly higher than the water control.Freezing-thawing significantly increased both the disease incidence andthe lesion size via lenticel infection. The lenticel inoculationdata suggest that P. syringae pv. syringae infection throughlenticels is possible under field conditions.

Introduction. Bacterial canker, caused by Pseudomonas syringaepv. syringae, is a devastating disease of stone fruit worldwide.The effects of mineral nutrients and freezing-thawing on bacterial canker susceptibilitywere evaluated using potted peach trees in an attempt to understand predisposing factorsin bacterial canker of stone fruit. Materials and methods. A split-plotexperimental design with randomized complete block main plots(i.e., inoculationsassociated with freezing-thawing or nonfrozen pretreatments) and subplots of trees withthe seven treatments(i.e., solutionsdeficient in N, P, K, Ca, Mg or Fe, respectively, and a full nutrient control) was adoptedto study the effect of mineral deficiency and freezing-thawing on peach susceptibility tobacterial canker. Results and discussion. Phosphorus deficiency was the onlytreatment to significantly decrease lesion length that developed after inoculation withP. syringae pv. syringae, compared with the controltrees that received full nutrients. Nitrogen and potassium deficiency treatmentssignificantly decreased bark nitrogen and potassium concentrations accordingly, but had noclear effect on lesion sizes. Inoculation during freezing-thawing cycles significantlyincreased lesion length. In another independent experiment, nitrogen deficiencysignificantly increased the number of P. syringae pv. syringaeleaf scar infections, but the subsequent infection was limited to a fewmillimeters. Nitrogen-deficient trees, which had higher [carbon / nitrogen] ratios,developed lesion sizes equivalent to trees provided with full nutrients. Collectively,these data suggest that, in the absence of other major predisposing factors(i.e., low soil pH or ringnematodes), mineral nutrients may play a minor role in the susceptibility of peach tobacterial canker.