Conservation or Preservation? A Qualitative Study of the Conceptual Foundations of Natural Resource Management

Few disputes in the annals of US environmentalism enjoy the pedigree of the conservation-preservation debate. Yet, although many scholars have written extensively on the meaning and history of conservation and preservation in American environmental thought and practice, the resonance of these concepts outside the academic literature has not been sufficiently examined. Given the significance of the ideals of conservation and preservation in the justification of environmental policy and management, however, we believe that a more detailed analysis of the real-world use and understanding of these ideas is needed. In this paper, we describe the results of a qualitative, semantic study of the concepts of conservation and preservation undertaken in the context of the Chattahoochee National Forest (CNF), located in northern Georgia (USA). Thirty in-depth interviews were conducted with scientists and north Georgia residents either interested or involved in the future management of the forest. Respondents were asked to define conservation and preservation in their own words and to indicate which approach they felt was more appropriate for the management of the CNF. Qualitative content analysis was used to elicit a set of recurring themes for each foundational concept. Taken together, these themes help to flesh out the meaning of conservation and preservation for citizens and scientists today, and illustrate the evolving nature of two of the more significant and venerable ideas animating US environmental policy and management.     

Pulsed electromagnetic field therapy history,state of the art and future

Magnetic and electromagnetic fields are now recognized by the 21st century medicine as real physical entities that promise the healing of various health problems, even when conventional medicine has failed. Today magnetotherapy provides a non-invasive, safe, and easy method to directly treat the site of injury, the source of pain and inflammation, and other types of diseases and pathologies. Millions of people worldwide have received help in treatment of musculoskeletal system, as well as pain relief. Pulsed electromagnetic fields are one important modality in magnetotherapy and recent technological innovations, such as Curatron pulsed electromagnetic field devices, offer excellent, state of the art computer controlled therapy system. In this article the development, state of the art and future of pulsed electromagnetic field therapy are discussed.     

Pluralism,The Ethical Matrix,and Coming to Conclusions

The ethical matrix approach was developed by Prof Ben Mepham and his colleagues at the University of Nottingham in the early 1990s. Since then the approach has received increasing attention and has been used by several researchers in different projects related to assessing ethical impacts of different food production technologies and other policy options of societal concern. The ethical matrix is sometimes understood simply as a checklist of ethical concerns, but might also be seen as a guide to coming to conclusions on moral questions. The problem I discuss in this paper relates to how using the ethical matrix method as a decision guide can be combined with respecting pluralism. The aim of the paper is to suggest a framework making it possible to – at the same time – enhance public justification of judgments and respect pluralism. I argue that pluralism is fundamental to the ethical matrix approach; I distinguish between intuitionist principled pluralism and societal value pluralism; and I show how both kinds of pluralism imply restrictions on how conclusions can be made. No substantive moral decision principles can be allowed. Still, I argue, decision principles of a more epistemological or procedural character can be acceptable even within pluralism. The pragmatist principle of inquiry is defended as an account of moral problem solving compatible with both principled pluralism and value pluralism. When an ethical matrix is used within such a participatory inquiry process substantive conclusions can be drawn.     

Enrichment of trace elements in the clay size fraction of mining soils

Reactive waste dumps with sulfide minerals promote acid mine drainage (AMD), which results in water and soil contamination by metals and metalloids. In these systems, contamination is regulated by many factors, such as mineralogical composition of soil and the presence of sorption sites on specific mineral phases. So, the present study dedicates itself to understanding the distribution of trace elements in different size fractions (<2-mm and <2-μm fractions) of mining soils and to evaluate the relationship between chemical and mineralogical composition. Cerdeirinha and Penedono, located in Portugal, were the waste dumps under study. The results revealed that the two waste dumps have high degree of contamination by metals and arsenic and that these elements are concentrated in the clay size fraction. Hence, the higher degree of contamination by toxic elements, especially arsenic in Penedono as well as the role of clay minerals, jarosite, and goethite in retaining trace elements has management implications. Such information must be carefully thought in the rehabilitation projects to be planned for both waste dumps.     

Simple model of sludge thickening process in secondary settlers

In wastewater treatment plants (WWTPs), a secondary settler acts as a clarifier, sludge thickener, and sludge storage tank during peak flows and therefore plays an important role in the performance of the activated sludge process. Sludge thickening occurs in the lower portions of secondary clarifiers during their operation. In this study, by detecting the hindered zone from the complete thickening process of activated sludge, a simple model for the sludge thickening velocity, u _s = aX ^b (a = 0.9925SSVI _3.5, b = 3.541ln(SSVI _3.5)+12.973), describing the potential and performance of activated sludge thickening in the hindered zone was developed. However, sludge thickening in the compression zone was not studied because sludge in the compression zone showed limited thickening. This empirical model was developed using batch settling data obtained from four WWTPs and validated using measured data from a fifth WWTP to better study sludge thickening. To explore different sludge settling and thickening mechanisms, the curves of sludge thickening and sludge settling were compared. Finally, it was found that several factors including temperature, stirring, initial depth, and polymer conditioning can lead to highly concentrated return sludge and biomass in a biologic reactor.     

Territory characteristics and coexistence with heterospecifics in the Dartford warbler <Emphasis Type="Italic">Sylvia undata</Emphasis> across a habitat gradient

The study of successional gradients may help to understand the relative influence of habitat structure and competition on territory characteristics. Here, we evaluate the effects of vegetation cover, conspecific and heterospecific densities, and distance to the nearest neighbor on territory size, shape, and overlap in insectivorous birds. We studied these effects along a gradient of postfire habitat regeneration in which foliage cover and densities of focal species varied several-fold. We delineate 197 territories (minimum convex polygons) of the shrub-dwelling Dartford warbler (Sylvia undata) and 255 of the syntopic Sardinian (Sylvia melanocephala), subalpine (Sylvia cantillans) and melodious (Hippolais polyglotta) warblers at three plots in NE Catalonia (Spain and France) in 1987–2005. After accounting for the effect of the number of locations used to delineate polygons, generalized linear mixed models (GLMM) showed a reduction in territory area of the Dartford warbler as conspecific density increased and distance to nearest neighbor decreased, in accordance with the contender pressure hypothesis for territory size regulation. Heterospecific density was not included in the final model of territory size and the effect of habitat structure was marginal. Territory roundness was positively correlated with its size and with conspecific density, probably in relation to energetic constraints, and negatively with heterospecific density. Territorial exclusion was almost complete among Dartford warblers, whereas interspecific territory overlap was extensive and tended to increase with heterospecific density and with structural diversity along the gradient. Our results support the hypothesis that Mediterranean warbler coexistence derives from ecological segregation and not from interspecific territoriality.     

The life cycles of two coexisting copepods, <Emphasis Type="Italic">Calanus chilensis</Emphasis> and <Emphasis Type="Italic">Centropages brachiatu</Emphasis>s,in the upwelling zone off northern Chile (23°S)

A time series study of the copepods Calanus chilensis and Centropages brachiatus was carried out at the coastal upwelling zone of Mejillones (23°S, northern Chile), to analyze their annual life cycles in association with upwelling variation. These species co-exist in the upwelling zone. Weekly sampling of zooplankton and oceanographic variables including Chlorophyll-a and phytoplankton composition were obtained during January–December 2002 at a fixed station (ca. 90 m depth). Stages of abundances, their proportions, changes in body length of adult females, sex ratio and egg production rate (EPR), were used as proxies to examine copepods’ demography. Upwelling, assessed by weekly Ekman transport and oceanographic conditions, was intermittent throughout the year with lack of periodicity components. Populations of both copepod species did not correlate with these non-predictable upwelling events. C. chilensis reproduced year-round and the population showed ca. 15 peaks of adults with an average time interval between peaks of 20 days. C. brachiatus showed a similar life cycle, also having 15 peaks of adults at about 22 days of time intervals. Cross-correlation functions and spectral analysis showed that both populations correlated positively through time, but not in phase, evidencing a time lag for their reproductive cycles. The lag was also evident in their population abundances. Both species differ in their development rates and this may result in non-in phase life cycles. Our findings suggest that species-dependent attributes, such as development rates, modulated by adaptations to temperature, might impose constraints in the species life cycles determining the population cycles. Such attributes must be considered when modeling and understanding population dynamics and secondary production of copepods.     

Effect of electrokinetic property of charged polyether sulfone membrane on bovine serum albumin fouling behavior

Negatively charged carboxymethylated polyethersulfone (CMPES) and positively charged quaternized polyethersulfone (QAPES) ultrafiltration (UF) membranes were prepared by bulk chemical modification and non-solvent induced phase separation method. The effects of PES membrane interfacial electrokinetic property on the bovine serum albumin (BSA) membrane fouling behavior were studied with the aid of the membrane-modified colloidal atomic force microscopy (AFM) probe. Electrokinetic test results indicated that the streaming potential (ΔE) of QAPES membrane was not consistent with its expected IEC value, however, within the pH range of 3–10, the ζ potentials of two charged-modified PES membranes were more stable than the unmodified membrane. When pH value was 3, 4.7 or 9, the interaction behavior between charged PES membrane and BSA showed that there was significant linear correlation between the jump distance r ₀ of membrane-BSA adhesion force (F/R) and the ζ potential absolute value. Charged modification significantly reduced the adhesion of PES membrane-BSA, and the adhesion data was good linear correlated with the flux decline rate in BSA filtration process, especially reflected in the CMPES membrane. The above experimental facts proved that the charged membrane interfacial electric double layer structure and its electrokinetic property had strong ties with the protein membrane fouling behavior.

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Migration of aluminum from food contact materials to food—a health risk for consumers? Part III of III: migration of aluminum to food from camping dishes and utensils made of aluminum

Background

When cooking on a barbecue grill, consumers often use aluminum grill pans. For one, the pan catches the fats and oils that would drip into the embers causing the formation of potentially noxious smoke, and the pan also protects the food from being burned by direct heat from the coals. In addition, new aluminum products for use in ovens and grills are becoming increasingly popular. Due to their light weight and excellent heat transfer camping, utensils made of aluminum are, for example, often used by fishermen and mountain climbers. Preparing food in aluminum utensils can, however, result in migration of the aluminum to the foodstuffs.

Results/Conclusions

In this study presented here, it was found that the transfer limit of 5.00 mg/L for aluminum is not exceeded using simulants for oil or for tap water; however, with an aqueous solution of 0.5% citric acid, the limit is clearly exceeded at 638 mg/L. This means that the Tolerable Weekly Intake (TWI) is exceeded by 298% for a child weighing 15 kg and for an adult weighing 70 kg it is equivalent to 63.8% of the TWI, assuming a daily uptake of 10 mL marinade containing lemon juice over a period of 1 week. Preparation of a fish dish with a marinade containing lemon juice in camping dishes would result in the TWI being exceeded by 871% for a child weighing 15 kg and by 187% for an adult weighing 70 kg assuming a daily uptake of 250 g over a period of 1 week.