How wildfire risk is related to urban planning and Fire Weather Index in SE France (1990-2013).

Wildfires burn >450,000ha of forest every year in Euro-Mediterranean countries. Many fires originate in the Wildland Urban Interface (WUI) where housing density and weather conditions affect fire occurrence. Housing density is determined by long term land use policies while weather conditions evolve quickly. The first objective was to quantify the impacts of land use policy on WUI characteristics and fire risk in SE France during 1990-2012. The second objective was to quantify how Fire Weather Index (FWI) is related to fire occurrence. WUI was mapped from 1990, 1999, and 2012 building layers and crossed with a NDVI derived vegetation layer. In all, 12 WUI categories were derived: 4 building density classes and 3 vegetation layers. The I87 FWI was based on daily temperature, wind speed, relative humidity and soil water content. Despite a 30% increase in the number of new buildings, WUI area increased by only 5% as new housing filled in open space in existing WUI area. This trend can be linked to national level urban planning legislation and forest fire protection laws. Major driver variables determining housing location were aspect, slope, and distance to city centers. Fire frequency and burned area were nonlinearly related to FWI: 73% of the 99 fires occurred during weeks with FWI values ≥90 even though these accounted for only 44% of all weeks. Burned area was even more sensitive to FWI since 97% of total burned area occurred during weeks with mean FWI values ≥90. All days with burned areas >100ha had FWI values >150. The study demonstrated that WUI legislation can be an efficient tool to limit WUI fire risk. FWI results suggest the predicted increase in extreme summer heat events with global warming could increase burned area as firefighting resources are stretched beyond capacity.

Evaluation of the efficiency of some sediment trapping methods after a Mediterranean forest fire.

Forest fires are common in Mediterranean environments and may become increasingly more frequent as the climate changes. Destruction of the forest cover and litter layer leads to greater overland flow and increased erosion rates. The greatest risk occurs during the first rainstorms following a major fire, so local authorities must act quickly to put erosion control methods in place in order to avoid excessive post-fire sediment loads in river channels. Deciding on which methods to use requires accurate knowledge of their impact on sediment load and an estimate of their cost efficiency. The objective of this study was to evaluate the efficiency of Log Debris Dams (LDDs) and a sedimentation basin for their effectiveness in trapping sediments. Paired sub-catchments were studied to quantify the amount of sediments trapped in stream channels by a series of LDDs and a sedimentation basin. Cost efficiency was evaluated for each of the measures as a function of the cost per unit volume of sediments trapped. In addition, grain size analyses were performed to characterise the nature of the sediments trapped. A third sediment trapping method, Log Erosion Barriers (LEBs) was evaluated more superficially than the first two and conclusions regarding this method are tentative. LDDs trapped a mean volume of 1.57 m³ per unit (median=1.28 m³); mean LDD height was 105.4 cm (std. dev.=21.9 cm), and mean height of trapped sediments was only 50.0 cm (std. dev.=22.9 cm), showing that the traps were only half filled. Sediment height was limited by the presence of gaps between logs or branches that allowed runoff to flow through. Comparison of the textural characteristics of slope and trapped sediments showed distinct sorting: particles greater than 20mm were not mobilised from the slopes during the study period, sediments in the medium to coarse sand size fractions were trapped preferentially by the LDDs, and sediments in the sedimentation basin were enriched by clay and silt sized (< 0.050 mm) particles as coarser sediments were trapped upstream by the LDDs. Cost efficiency of LDDs was estimated at about 143 € m⁻³ for the LDDs and 217 € m⁻³ for the sedimentation basin at the time of sampling. The LDDs are therefore a cost effective method of trapping sediments, but they can only be used when pine trees or straight-trunked trees are locally available. In this case, they should be combined with LEBs, which had a cost efficiency estimated at about 250 € m⁻³. Installation of the LEBs had not been optimised and they have the advantage of trapping sediments on the slopes where they can continue to play an ecological role, so this method can give better results with more care. Sedimentation basins can be emptied if necessary and are useful in areas where pine trees are not available and where the site can be secured.

The role of soil surface crusting in desertification and strategies to reduce crusting.

Soil crusting decreases infiltration, increases erosion, and impedes vegetation establishment, so reducing the impact of crusting is of major importance in combating desertification. Although surface crusting has been the subject of considerable research over the past 50 years or more, the practical management of soil crusts remains a challenge for many dryland communities. Crusting occurs in two steps, an initial aggregate breakdown period that occurs under rainfall and a subsequent hardening phase during drying. Several factors influence crust development, but the single most important one is soil aggregate stability. Strategies to reduce crusting can be based either on protecting the surface from raindrop impact or improving aggregate stability, or a combination of both. However, crust control is labor and/or capital intensive and must be thought out clearly in terms of the benefits to be achieved.

The professions of public health.

Law has been an essential tool of public health practice for centuries. From the 19th century until recent decades, however, most histories of public health described, approvingly, the progression of the field from marginally useful policy, made by persons learned in law, to effective policy, made by persons employing the methods of biomedical and behavioral science. Historians have recently begun to change this standard account by documenting the centrality of law in the development of public health practice. The revised history of public health offers additional justification for the program of public health law reform proposed in this issue of the Journal by Gostin and by Moulton and Matthews, who describe the new program in public health law of the Centers for Disease Control and Prevention.

Epibulbar granular cell tumor. Report of a case and review of the literature.

BACKGROUND: The granular cell tumor (GCT) is a common, usually benign, neoplasm of uncertain histogenesis that may affect any organ in the body. It occurs rarely in ophthalmic sites, where orbital location is most frequent. The purpose of this report is to describe a unique case of an epibulbar, subconjunctival GCT in a child. METHOD: Histopathologic examination of the excised tumor included standard and immunohistochemical staining of formaldehyde-fixed, paraffin-embedded tissue. RESULTS: Histopathologic study showed the characteristic morphology of GCT. Immunohistochemistry was strongly positive for vimentin, weakly and partly positive for neuron-specific enolase, and negative for S-100 and HAM-56. CONCLUSIONS: Granular cell tumor must be added to the differential diagnosis of epibulbar masses. Immunohistochemistry of the tumor in this case suggests an uncommitted mesenchymal cell origin.

Conjunctival neurilemoma. Report of 3 cases.

Neurilemoma (schwannoma) of the conjunctiva is a rare ocular tumor. We report 3 cases of benign conjunctival neurilemoma occurring in women without other ocular or systemic disease. Two of these tumors arose from the bulbar conjunctiva and 1 from the tarsal conjunctiva. Immunoperoxidase staining for S-100 protein was positive in each case.

From piety to platitudes to pork: the changing politics of health workforce policy.

Policy to subsidize the education of health professionals in the United States has become contentious and uncertain. This article examines the politics of workforce policy in the twentieth century, emphasizing the years since World War II. From early in the century until the 1970s, most decision makers viewed policy to subsidize the education of health professionals as self-evidently correct. As consensus eroded, proponents insisted to increasingly skeptical audiences that these subsidies created benefits for the public. Recently, decision makers outside health care institutions have come to regard workforce policy as serving particular rather than general interests. Thus health workforce policy, like other policies outside of health affairs, may be said, perhaps oversimply but not inaccurately, to have gone through three stages: from piety to platitudes to pork.