Scenario modeling potential eco-efficiency gains from a transition to organic agriculture: life cycle perspectives on Canadian canola, corn, soy, and wheat production.

We used Life Cycle Assessment to scenario model the potential reductions in cumulative energy demand (both fossil and renewable) and global warming, acidifying, and ozone-depleting emissions associated with a hypothetical national transition from conventional to organic production of four major field crops [canola (Brassica rapa), corn (Zea mays), soy (Glycine max), and wheat (Triticum aestivum)] in Canada. Models of these systems were constructed using a combination of census data, published values, and the requirements for organic production described in the Canadian National Organic Standards in order to be broadly representative of the similarities and differences that characterize these disparate production technologies. Our results indicate that organic crop production would consume, on average, 39% as much energy and generate 77% of the global warming emissions, 17% of the ozone-depleting emissions, and 96% of the acidifying emissions associated with current national production of these crops. These differences were almost exclusively due to the differences in fertilizers used in conventional and organic farming and were most strongly influenced by the higher cumulative energy demand and emissions associated with producing conventional nitrogen fertilizers compared to the green manure production used for biological nitrogen fixation in organic agriculture. Overall, we estimate that a total transition to organic production of these crops in Canada would reduce national energy consumption by 0.8%, global warming emissions by 0.6%, and acidifying emissions by 1.0% but have a negligible influence on reducing ozone-depleting emissions.

Laboratory sleep correlates of nightmare complaint in PTSD inpatients.

BACKGROUND: Nightmares are rare in the sleep laboratory, even in patients with posttraumatic stress disorder for whom nightmare complaints are diagnostic. Nevertheless, it is possible that laboratory conditions do not preclude the observation of telltales-nightmare-related modifications of tonic sleep-given sufficiently large samples. METHODS: Sixty-three unmedicated, nonapneic Vietnam combat veterans undergoing inpatient treatment for posttraumatic stress disorder underwent polysomnographic testing and assessment of nightmare complaint. RESULTS: Trauma-related nightmare complaint, but not non-trauma-related complaint, was associated with increased wake-after-sleep-onset in the sleep laboratory. No relationships between nightmare complaint and rapid eye movement sleep architecture were observed. CONCLUSIONS: Increased wake-after-sleep-onset was specifically associated with trauma-related nightmare complaint, confirming data from other quarters suggesting they are both phenomenologically and functionally distinct from normal dreaming.

Heart rate during group flooding therapy for PTSD.

The objective of this study was to assess, via heart rate, the arousal levels of participants in group trauma reexposure therapy for posttraumatic stress disorder, and so to better understand this common mode of treatment, particularly in regards to its presumed curative factor, extinction. Six Vietnam combat-related PTSD inpatients participated twice weekly in group trauma reexposure therapy during which their electrocardiograms were recorded. Heart rate was quantified continuously off-line. Heart rates of participants not directly engaged in imaginal reexposure to their personal combat traumas consistently exhibited mild linear declines from the beginnings to the ends of the approximately 2.5 hour sessions. Participants actively engaged in personal combat trauma reexposure exhibited higher whole-session heart rates. Most also exhibited more specific elevation extending over the later portions of therapy sessions during which intensive reexposure usually occurred. Surprisingly, no patients exhibited focal increases in heart rate concurrent with periods of most intensive traumatic incident review as judged from videotape. Administering imaginal reexposure in a group context does not preclude substantial physiological (sympathetic) arousal, as is preconditional for extinction. Under conditions in which the actively engaged reexposure patient is reliably identified, group trauma reexposure therapy may not provide an opportunity for "vicarious" flooding in nonengaged participants.

Voice onset time production in French-speaking aphasics.

VOT productions were compared for 5 Broca's aphasics and 5 Wernicke's aphasics to those for a group of 5 normal subjects of similar age. Phonetic errors were produced by both types of aphasic patients, but not by normal controls. Although previous studies have found significantly more phonetic errors in VOT production for Broca's aphasics, this study did not. Both Broca aphasics and Wernicke aphasics had somewhat less overall average difference in VOT between voiced and voiceless consonant pairs than normal speakers. Standard deviations associated with the VOT productions were also greater for both aphasic groups than for normal subjects. The results of this study are considered in light of the previous literature.