Over-expressing the C3 photosynthesis cycle enzyme Sedoheptulose-1-7 Bisphosphatase improves photosynthetic carbon gain and yield under fully open air CO2fumigation (FACE)

Abstract Background Biochemical models predict that photosynthesis in C3 plants is most frequently limited by the slower of two processes, the maximum capacity of the enzyme Rubisco to carboxylate RuBP (Vc,max), or the regeneration of RuBP via electron transport (J). At current atmospheric [CO2] levels Rubisco is not saturated; consequently, elevating [CO2] increases the velocity of carboxylation and inhibits the competing oxygenation reaction which is also catalyzed by Rubisco. In the future, leaf photosynthesis (A) should be increasingly limited by RuBP regeneration, as [CO2] is predicted to exceed 550 ppm by 2050. The C3 cycle enzyme sedoheptulose-1,7 bisphosphatase (SBPase, EC 3.1.3.17) has been shown to exert strong metabolic control over RuBP regeneration at light saturation. Results We tested the hypothesis that tobacco transformed to overexpressing SBPase will exhibit greater stimulation of A than wild type (WT) tobacco when grown under field conditions at elevated [CO2] (585 ppm) under fully open air fumigation. Growth under elevated [CO2] stimulated instantaneous A and the diurnal photosynthetic integral (A') more in transformants than WT. There was evidence of photosynthetic acclimation to elevated [CO2] via downregulation of Vc,max in both WT and transformants. Nevertheless, greater carbon assimilation and electron transport rates (J and Jmax) for transformants led to greater yield increases than WT at elevated [CO2] compared to ambient grown plants. Conclusion These results provide proof of concept that increasing content and activity of a single photosynthesis enzyme can enhance carbon assimilation and yield of C3 crops grown at [CO2] expected by the middle of the 21st century. </jats:sec

To Determine the Active and Inactive Hours for Sound Sows When Housed in Individual Pens

There are currently no analgesic drugs specifically approved for pain relief in livestock by the U.S Food and Drug Administration (FDA). Therefore, the objective of this study was to (1) identify the active hours of sound sows and (2) use this information to watch these active hours of the same sows when lame and after pain mitigation treatments. To avoid confounding injury due to aggression, twelve, clinically normal, mixed-parity, crossbred sows were purchased from a commercial producer in Iowa and housed in individual pens at Iowa State University. One 12 v black and white CCTV camera was affixed above the pen. Video was captured onto a DVR at 10 frames per second in black and white mode. Scoring of video began at 0600 and ended at 1800 and two postures (active and inactive), out of pen or unknown were collected. All behavioral data were expressed as percentages and were subjected to a square root arcsine transformation process to normalize the distribution. Transformed data were analyzed using the PROC MIXED procedure in SAS®. A P value of P ≤ 0.05 was considered to be significant. No differences were observed for out of pen (P = 0.24) or unknown (P = 0.71) for the sows. There was a difference for the time spent active (P = 0.0003) versus inactive (P = 0.0052) over the 12-h for sows. Sows were most active at 0800 (59 %) and at 1600 (66 %) which corresponded to the feeding schedule. The least active hours were 0600, 0700, and 1700 h respectively. In conclusion the critical active hours for these sows were around feeding schedules. Therefore, it is beneficial to watch from 0800 to 1659 to capture when the sows are most active in their home pen environment

Scan Sampling Techniques for Behavioral Validation in Nursery Pigs

Behavioral observations are a type of “assay” that is used to quantify animal biological responses. As with physiological measurements, methods of behavioral observation should be validated and selected based on the objectives of the particular study. The objective of this study was to validate the accuracy of scan samples at various predetermined intervals for confined nursery pigs. Twenty, 35 day old, crossbred PIC (USA) nursery pigs were housed in five pens within a confinement building. Eight scan sample treatments (1, 2, 3, 5, 10, 15, 30, and 60 minutes) were individually compared to continuous observation. Scan sample was defined as the first second for each scan interval (1 minute scan sample intervals provided 60 selected scans of one second duration per pig per hour). The percentage of the total time observed for each behavior and posture then calculated for each pen. Drinking differed (P = 0.0019) from the continuous data at intervals greater than 5 minutes or more. For all other behaviors and postures there were no (P \u3e 0.05) differences between scan treatments and the continuous data. In conclusion, scan samples under these experimental conditions were accurate for all behaviors and postures except drinking

Patterns of impact resulting from a 'sit less, move more' web-based program in sedentary office employees.

PURPOSE: Encouraging office workers to 'sit less and move more' encompasses two public health priorities. However, there is little evidence on the effectiveness of workplace interventions for reducing sitting, even less about the longer term effects of such interventions and still less on dual-focused interventions. This study assessed the short and mid-term impacts of a workplace web-based intervention (Walk@WorkSpain, W@WS; 2010-11) on self-reported sitting time, step counts and physical risk factors (waist circumference, BMI, blood pressure) for chronic disease. METHODS: Employees at six Spanish university campuses (n=264; 42±10 years; 171 female) were randomly assigned by worksite and campus to an Intervention (used W@WS; n=129; 87 female) or a Comparison group (maintained normal behavior; n=135; 84 female). This phased, 19-week program aimed to decrease occupational sitting time through increased incidental movement and short walks. A linear mixed model assessed changes in outcome measures between the baseline, ramping (8 weeks), maintenance (11 weeks) and follow-up (two months) phases for Intervention versus Comparison groups. RESULTS: A significant 2 (group) × 2 (program phases) interaction was found for self-reported occupational sitting (F[3]=7.97, p=0.046), daily step counts (F[3]=15.68, p=0.0013) and waist circumference (F[3]=11.67, p=0.0086). The Intervention group decreased minutes of daily occupational sitting while also increasing step counts from baseline (446±126; 8,862±2,475) through ramping (+425±120; 9,345±2,435), maintenance (+422±123; 9,638±3,131) and follow-up (+414±129; 9,786±3,205). In the Comparison group, compared to baseline (404±106), sitting time remained unchanged through ramping and maintenance, but decreased at follow-up (-388±120), while step counts diminished across all phases. The Intervention group significantly reduced waist circumference by 2.1cms from baseline to follow-up while the Comparison group reduced waist circumference by 1.3cms over the same period. CONCLUSIONS: W@WS is a feasible and effective evidence-based intervention that can be successfully deployed with sedentary employees to elicit sustained changes on "sitting less and moving more"