The historical evidence for the Indians' burning the forests of the northeastern United States is reevaluated. Of 35 documents that describe vegetation or Indian life in the 16th or 17th centuries, only half mention any use of fire except for cooking. Only six purportedly first—hand accounts might refer to purposeful, widespread, and frequent use of fire. These six are all consistent with use of fire only locally near camps or villages, or with accidentally escaped fires. It is concluded that the frequent use of fires by the Indians to burn the forests was probably at most a local occurrence. The Indians' presence in the region and their use of fire for many purposes did, however, increase the frequency of fires above the low levels caused by lightning, and thus had some effect on the vegetation; for example, grasses characterized the ground cover at small, local, frequently burned sites.

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Delayed wound healing can cause significant issues for immobile and ageing individuals as well as those living with co-morbid conditions such as diabetes, cardiovascular disease, and cancer. These delays increase a patient’s risk for infection and, in severe cases, can result in the formation of chronic, non-healing ulcers (e.g., diabetic foot ulcers, surgical site infections, pressure ulcers and venous leg ulcers). Chronic wounds are very difficult and expensive to treat and there is an urgent need to develop more effective therapeutics that restore healing processes. Sustained innate immune activation and inflammation are common features observed across most chronic wound types. However, the factors driving this activation remain incompletely understood. Emerging evidence suggests that the composition and structure of the wound microbiome may play a central role in driving this dysregulated activation but the cellular and molecular mechanisms underlying these processes require further investigation. In this review, we will discuss the current literature on: 1) how bacterial populations and biofilms contribute to chronic wound formation, 2) the role of bacteria and biofilms in driving dysfunctional innate immune responses in chronic wounds, and 3) therapeutics currently available (or underdevelopment) that target bacteria-innate immune interactions to improve healing. We will also discuss potential issues in studying the complexity of immune-biofilm interactions in chronic wounds and explore future areas of investigation for the field.

The adsorption of silicate and phosphate from pure and mixed solutions by four soils known to fix phosphate strongly has been measured.The adsorption at constant pH for each acid from its pure solution follows the Langmuir isotherm. The maximum adsorption of silicate by three of the soils from the pure solution occurs at pH 9.2, and the maximum adsorption curve for phosphate by two of the soils from its pure solution has a break in its slope at pH 6.4 and 11.6. These pHs are all just below the pK values for the dissociation of hydrogen ions from the undissociated silicic acid or the acid phosphate anions. The presence of silicate in a mixed solution, which is sufficiently concentrated in both silicate and phosphate to give maximum adsorption of either if in pure solution, does not affect the amount of phosphate adsorbed until the pH is over 6.5-7.0. At this pH the maximum adsorption curve for silicate crosses that for phosphate. The presence of phosphate in the mixed solution always depresses the adsorption of silicate. The maximum amount of silicateplus-phosphate adsorbed from this mixed solution is either a little less than or equal to the amount of silicate adsorbed from the pure silicate solution if the pH is above 7. When silicate displaces phosphate, or phosphate displaces silicate, more moles of the displacing acid are adsorbed than moles of the displaced acid released.These results for soils are similar to those of Hingston et al. for the adsorption of silicate and phosphate by goethite.

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Aim This study compares human impacts and forest ecosystem response across geographical regions. Such a comparison allows us to evaluate the relationship between regional changes in forest composition and regional patterns of human activity.Location Four study areas in the north-eastern USA were investigated, two of which were dominated by oak-pine forests at the time of European settlement (Central Massachusetts, MA; Pike County, PA), and two of which were dominated by beech and hemlock (South Berkshire, MA; Wayne County, PA).Methods Trees recorded in early land survey records were compiled and compared with data on modern forest composition obtained from recent forest inventories. To assess the similarity of the four regions with regard to species composition, Euclidean Distances (ED) were calculated between the colonial and modern forest composition for each of the four regions. Information about the history of human impacts in the four study regions was used to interpret the changes in forest composition. ResultsGeneral changes in forest composition through the historical period include a decline in beech, hemlock and chestnut, and an increase in maple and birch. Changes in pine and oak were minor by comparison. Supraregional human impacts are generally linked with supraregional trends in species composition, whereas regional patterns of land use caused regional patterns of change in species composition. Main conclusionsThese results suggest that human activities do not necessarily lead to more similar species composition between regions, especially if these activities show clear spatial patterns at about the same resolution that species composition is evaluated. Comparing species-specific changes in forest composition with species-specific human activities on the same spatial scale is crucial in order to evaluate human impacts on ecosystems and to make more robust generalizations about the temporal dynamics of landscapes.

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