The sinking ark: pollution and the worldwide loss of biodiversity

Humans are making increasing demands on natural ecosystems. One recent study has concluded that our species is consuming or diverting some 40% of the net photosynthetic productivity of our planet. Many habitats are being converted to simpler systems which provide more harvestable goods to people. As a result, genetic diversity, species and whole ecosystems are disappearing; some scientists suggest that as many as 25% of the world's species could be lost in the next several decades.The sinking ark is usually characterized in terms of pollution, habitat loss, poaching, introduced species and illegal trade in wildlife products, but these are symptoms rather than causes. At a more fundamental level, many of the same factors which have enabled pollution to become such a problem have also been responsible for the loss in biodiversity; the most important factor is that the effects of pollutants on biodiversity have been considered an externality, an unintended side effect of industrial activity which brought measurable benefits to people. Development activities which have depleted biodiversity have proven profitable only because the real costs have been hidden.Keeping the ark afloat will require the Five-I Approach: investigation (learning how natural systems function); information (ensuring that the facts are available to inform decisions); incentives (using economic tools to help conserve biodiversity); integration (promoting a cross-sectoral approach to conserving biodiversity); and international support (building productive collaboration for conserving biodiversity).     

Limnologic consequences of the decline in hemlock 4800 years ago in three Southern Ontario lakes

Four thousand eight hundred years ago hemlock (Tsuga canadensis) populations were decimated throughout eastern North America. We have studied the effects of this loss from the terrestrial community on three Southern Ontario lakes: Little Round Lake, Sunfish Lake, and McKay Lake. This study includes the use of cladocerans, diatoms, chrysophytes, and bacterial pigments to assess the limnologic changes that occurred in these lakes. Each lake experienced a change in trophic status that coincided with the loss of hemlock from its catchment, but the change in the aquatic biota was different in each lake. The lakes' size may have been the most influential factor governing the response to this terrestrial disturbance.     

Keep all the pieces: Systematics 2000 and world conservation

Conserving biological diversity requires a major effort in conducting survey and inventories, establishing priorities, selecting protected areas, managing resources and monitoring the effects of management. Systematics has an important contribution to make to each of these five major activities. Further, the new Convention on Biological Diversity requires systematics information to support action under virtually all of its substantive conservation and sustainable use articles. It seems apparent that large reference collections contribute directly to development, and development assistance agencies should recognize that investing in maintaining these collections is a legitimate form of development assistance.     

Food habits of channel catfish in a reservoir receiving heated waters

The diet of channel catfish captured near the mouth of a channel carrying heated waters was not significantly different from the diet of catfish captured elsewhere in the same reservoir during the cool months of the year. In summer months, however, the diet of catfish captured near the effluent was significantly different from the diet of catfish from other locations and seemed to indicate that catfish were foraging in cool, deeper waters beneath the thermal plume.Department of Biological Sciences, North Texas State UniversityFinancial support for the study was provided by a Faculty Research Grant at North Texas State University.     

Factors that influence the radiofrequency power output of GSM mobile phones

Epidemiological studies of mobile phone use and risk of brain cancer have relied on self-reported use, years as a subscriber, and billing records as exposure surrogates without addressing the level of radiofrequency (RF) power output. The objective of this study was to measure environmental, behavioral and engineering factors affecting the RF power output of GSM mobile phones during operation. We estimated the RF-field exposure of volunteer subjects who made mobile phone calls using software-modified phones (SMPs) that recorded output power settings. Subjects recruited from three geographic areas in the U.S. were instructed to log information (place, time, etc.) for each call made and received during a 5-day period. The largest factor affecting energy output was study area, followed by user movement and location (inside or outside), use of a hands-free device, and urbanicity, although the two latter factors accounted for trivial parts of overall variance. Although some highly statistically significant differences were identified, the effects on average energy output rate were usually less than 50% and were generally comparable to the standard deviation. These results provide information applicable to improving the precision of exposure metrics for epidemiological studies of GSM mobile phones and may have broader application for other mobile phone systems and geographic locations.     

Deciding about mechanical ventilation in end-stage chronic obstructive pulmonary disease: how respirologists perceive their role

OBJECTIVE: To determine when respirologists approach patients with end-stage chronic obstructive pulmonary disease (COPD) to decide about the use of mechanical ventilation, what information they provide to patients and how they provide it. DESIGN: Self-administered national survey. PARTICIPANTS: All Canadian specialists in respiratory medicine; of 401 eligible respirologists, 279 (69.6%) returned a completed questionnaire. OUTCOME MEASURES: Timing and content of doctor-patient discussions regarding mechanical ventilation; physicians'' perception of their level of involvement in the decision-making process; and patient and physician characteristics that may influence decisions. RESULTS: Discussions were reported to occur most often at advanced stages of COPD: when the patient''s dyspnea was severe (reported by 235 [84.2%] of the respondents) or when the patient''s forced expiratory volume in the first second was 30% or less than predicted value (reported by 210 [75.3%]). A total of 120 respondents (43.0%) stated that they discuss mechanical ventilation with 40% or less of their COPD patients before an exacerbation necessitates ventilatory support. Most (154 [55.2%]) described the decision-making process as a collaboration between patient and physician; 83 (29.7%) reported that the patient decides after he or she has considered the physician''s opinion. Over half (148 [53.0%]) of the respondents indicated that they occasionally, often or always modify the information provided to patients in order to influence their decision about mechanical ventilation. CONCLUSIONS: Discussions with COPD patients concerning end-of-life decisions about mechanical ventilation are reported to occur in advanced stages of the disease or not at all, with patients'' input where possible. Information presented to patients is often modified in order to influence the decision. Future studies should explore ways to involve patients further in the decision-making process and to improve the process for both patients and physicians.