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Introduction: New national guidance on urgent referral for investigation for Colorectal Cancer (CRC) included faecal occult blood testing in 2015. We evaluated faecal immunochemical testing (FIT) and anaemia as risk stratification tools in symptomatic patients suspected of having CRC.Methods: Postal FIT was incorporated into the CRC two week wait (2WW) pathway for all patients without rectal bleeding in 2016. Patients were investigated in the 2WW pathway as normal and outcomes of investigations were prospectively recorded. Anaemia was defined as haemoglobin less than 120g/L in women and less than 130g/L in men.Results: FIT kits were sent to 1106 patients with an 80.9% return rate; 810 patients completed investigation with 40 CRCs diagnosed (4.9%). Median FIT results were significantly higher in patients who were anaemic (median 4.8 iqr 0.8-34.1 versus 1.2 iqr 0-6.4, Mann-Whitney p less than 0.001).Some 538 (60.4%) had a result of less than 4 µgHb/gFaeces (limit of detectability) and 621 (69.7%) a result less than 10 µgHb/gFaeces. Sixty per cent of CRCs had a FIT reading of >150 µgHb/gFaeces. Five CRCs diagnosed in patients with a FIT4 µgHb/gFaeces had 97.5% sensitivity and 64.5% specificity for CRC diagnosis. A FIT result of >4 µgHb/gFaeces and/or anaemia had a 100% sensitivity and 45.3% specificity for CRC diagnosis.Conclusion: FIT is most useful at the extremes of detectability; strongly positive readings predict high rates of CRC and other significant pathology, whilst very low readings in the absence of anaemia or palpable rectal mass identify a group with very low risk. High return rates for FIT within this 2WW pathway indicate its acceptability.

Carbon dioxide concentration during the dark is often not controlled in investigations of plant growth or in studies of plant responses to elevated [CO_2] in the field. In this work we have investigated whether [CO_2] at night significantly affected the growth of soybean seedlings, and whether this varied with the magnitude of the day/night temperature variation. Plants were grown under day/night [CO_2]s of 350/350, 350/700, 700/700 and 700/350μmol mol^ [CO_2] in controlled-environment chambers under four temperature regimes. Field studies were also conducted using semi-open chambers in which plants were fumigated with air at the ambient [CO_2] or with air at ambient +350μmol mol^ [CO_2] applied only during the day, only at night, or for 24h per day. When the day [CO_2] was low, elevated [CO_2] at night decreased plant leaf area and dry mass with constant day/night temperatures, but had no effect when there was a diurnal change in temperature. With high [CO_2] in the day, elevated [CO_2] at night decreased plant leaf area and dry mass when the diurnal change in temperature was small, but increased these parameters when the diurnal change in temperature was larger. The data for the field was similar to that obtained in the controlled-environment chambers in the regimes with the larger diurnal temperature changes. No effect of elevated [CO_2] on leaf area or biomass was observed in the field when the elevated [CO_2] treatment was applied only in the daytime. Additionally, the results indicate that a build up of [CO_2] at night in controlled-environment chambers or in the field can significantly reduce plant biomass under some temperature regimes for plants grown at low [CO_2] in the day time. The results indicate the usefulness of controlling [CO_2] at night in studies of plant growth.

To predict time to flowering in field-grown soybean [Glycine max (L.) Merrill], it is essential to know how floral initiation and development are affected by changing daylengths. There is some evidence that both the rate of change in daylength and the direction of that change affect flowering. The purpose of this research was to establish how increasing and decreasing daylengths of various magnitudes influenced progress toward floral initiation (R0) and progress in floral development (R0 to R1). Seeds of 'Johnston' (MG VIII) and 'Clark' (MG IV) were sown every two weeks in a greenhouse at 39° N latitude in which temperature was controlled at 25℃ day and night. The time from the end of juvenility to floral initiation (R0) and the floral development phase (time from R0 to first open flower, R1) were recorded for each cultivar. R0 was determined by apical dissection at 45×magnification. Most of the variation in the time to floral initiation in 'Johnston' could be accounted for by a constant value when daylengths were below≈13h and a linear increase when mean daylengths exceeded 13h. The time to R0 in increasing daylengths was not different from the time to R0 in decreasing daylengths when the magnitudes of the daylengths during the floral initiation phase were similiar. The length of the floral development phase in 'Johnston' was longer when mean daylengths exceeded 13h, suggesting that the floral development phase was also sensitive to photoperiod. However, the end of sensitivity to photoperiod coincided with R0 when mean daylengths were≤13h, suggesting that photoperiod during the floral development phase did not influence development equally over the time to R1. There were small but significant increases in time to R0 and in the length of floral development in 'Clark' as daylength increased, but no effect of direction of change in daylength was apparent in either phase. Photoperiod sensitivity during floral development was not established unequivocally. At least part of the period between R0 and R1 was not sensitive to photoperiod. Time to flowering could be explained without invoking an effect of change in direction of daylength.

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