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INTRODUCTION: Wearable sensor technologies enable Defence to optimise human performance, remotely identify physiological abnormalities and enhance medical support. Maximising the acceptability of devices will ensure they are worn alongside other equipment. This study assessed the acceptability and comfort of four devices at different anatomical locations during military training. METHOD: A cross-sectional pilot study during a live firing infantry exercise or adventurous training assessed four anatomical locations concurrently over 5 days: finger, wrist, upper arm and chest. Participants rated comfort, acceptability and preference using a standardised questionnaire after 12 hours and 5 days of wear. RESULTS: Twenty-one regular British Army personnel soldiers participated, aged 24.4 (4.3) years. The upper arm location received the highest rating by participants for comfort, followed in order by wrist, finger and chest (p=0.002, Χ2=40.0). The finger was most commonly identified as uncomfortable during specific activities (76%), followed by chest (48%), wrist (23%) and upper arm devices (14%). There was no significant difference in participant confidence in the devices to collect data or allow movement, but there was a trend towards greater confidence in upper arm and wrist locations to stay in position than the others (p=0.059, Χ2=28.0). After 5 days of wear, 43% of participants said they preferred the upper arm for comfort, followed by wrist (36%), finger (24%) and chest (10%). 73% and 71% would wear the wrist and upper arm devices on deployed operations, compared with 29% and 24% for chest and finger devices, respectively. CONCLUSION: The upper arm location offered greater acceptability and comfort than finger, wrist or chest locations. It is essential to consider such findings from occupationally relevant settings when selecting wearable technology. A larger service evaluation in diverse settings is recommended to guide the choice of the most acceptable wearable devices across different equipment, roles and environments.

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For most individuals residing in Northwestern Europe, maintaining replete vitamin D status throughout the year is unlikely without vitamin D supplementation and deficiency remains common. Military studies have investigated the association with vitamin D status, and subsequent supplementation, with the risk of stress fractures particularly during recruit training. The expression of nuclear vitamin D receptors and vitamin D metabolic enzymes in immune cells additionally provides a rationale for the potential role of vitamin D in maintaining immune homeostasis. One particular area of interest has been in the prevention of acute respiratory tract infections (ARTIs). The aims of this review were to consider the evidence of vitamin D supplementation in military populations in the prevention of ARTIs, including SARS-CoV-2 infection and consequent COVID-19 illness. The occupational/organisational importance of reducing transmission of SARS-CoV-2, especially where infected young adults may be asymptomatic, presymptomatic or paucisymptomatic, is also discussed.

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INTRODUCTION: Expedition ICE MAIDEN (Ex IM) was the first all-female unsupported crossing of Antarctica. We describe the prerequisite selection and training, comparing those who formed the final team with other participants, and discuss how the expedition diet was established. METHODS: All women serving in the British Army were invited to participate. Following initial assessments, successful women completed three training/selection ski expeditions. Between expeditions 1 and 2, participants completed 6 months rigorous UK-based training. Weight was measured before and after the 6 months UK-based training, expeditions 2 and 3, and body composition by skinfold before and after expedition 2. Participant feedback, body composition and weight changes were applied to modify the expedition diet and provide weight gain targets prior to Ex IM. RESULTS: Following 250 applications, 50 women were assessed and 22, 12 and seven women attended training expeditions 1, 2 and 3, respectively. The final team of six women lost more weight than other participants during UK-based training (mean (SD) change -1.3 (1.5) kg vs -0.5 (1.6) kg, respectively, p=0.046) and during training expedition 2 (-2.8 (0.8) kg vs -1.7 (0.4) kg, respectively, p=0.048), when they also gained more lean mass (+2.1 (0.8) kg vs +0.4 (0.7) kg, respectively, p=0.004). The Ex IM diet provided 5000 kCal/day, comprising approximately 45% carbohydrate, 45% fat and 10% protein. Median (range) weight change between expedition 3 and Ex IM was +8.7 (-1.9 to +14.3) kg. CONCLUSIONS: The selected Ex IM team demonstrated favourable training-associated body composition changes. Training-associated weight loss informed the expeditionary diet design.

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BACKGROUND: Basic military training (BMT) is a useful model of prolonged exposure to multiple stressors. 8-12 week BMT is associated with perturbations in the hypothalamic-pituitary-adrenal (HPA) axis which could predispose recruits to injury and psychological strain. However, characterisations of HPA axis adaptations during BMT have not been comprehensive and most studies included few if any women. METHODS: We studied women undertaking an arduous, 44-week BMT programme in the UK. Anxiety, depression and resilience questionnaires, average hair cortisol concentration (HCC), morning and evening saliva cortisol and morning plasma cortisol were assessed at regular intervals throughout. A 1-h dynamic cortisol response to 1 µg adrenocorticotrophic hormone-1-24 was performed during weeks 1 and 29. RESULTS: Fifty-three women (aged 24 ± 2.5 years) completed the study. Questionnaires demonstrated increased depression and reduced resilience during training (F 6.93 and F 7.24, respectively, both p < 0.001). HCC increased from 3 months before training to the final 3 months of training (median (IQR) 9.63 (5.38, 16.26) versus 11.56 (6.2, 22.45) pg/mg, p = 0.003). Morning saliva cortisol increased during the first 7 weeks of training (0.44 ± 0.23 versus 0.59 ± 0.24 µg/dl p < 0.001) and decreased thereafter, with no difference between the first and final weeks (0.44 ± 0.23 versus 0.38 ± 0.21 µg/dl, p = 0.2). Evening saliva cortisol did not change. Fasting cortisol decreased during training (beginning, mid and end-training concentrations: 701 ± 134, 671 ± 158 and 561 ± 177 nmol/l, respectively, p < 0.001). Afternoon basal cortisol increased during training while there was a trend towards increased peak stimulated cortisol (177 ± 92 versus 259 ± 13 nmol/l, p = 0.003, and 589 ± 164 versus 656 ± 135, p = 0.058, respectively). DISCUSSION: These results suggest a normal stress response in early training was followed quickly by habituation, despite psychological and physical stress evidenced by questionnaire scores and HCC, respectively. There was no evidence of HPA axis maladaptation. These observations are reassuring for women undertaking arduous employment.

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BACKGROUND: Laparotomy under general anesthesia is associated with depressed natural killer cell cytotoxicity (NKCC) and compromised clearance of tumor cells. We tested the hypothesis that awake epidural anesthesia (AEA) improves NKCC compared to conventional general endotracheal anesthesia (GEA). PATIENTS AND METHODS: Preoperative, perioperative, and postoperative (day 3) NKCC, plasma epinephrine, norepinephrine, cortisol levels, and 24-hour urinary cortisol levels were measured in 20 patients undergoing open colectomy under either AEA or GEA. RESULTS: Preoperative and postoperative measurements were not significantly different in the two groups. Patients receiving GEA had a significant reduction in NKCC from 36% +/- 4% preoperatively to 22% +/- 4% perioperatively (P = 0.02). Patients receiving AEA had no significant change in NKCC. Perioperative plasma epinephrine and cortisol levels were higher with GEA than AEA. The perioperative 24-hour urinary cortisol excretion values were significantly higher in the group receiving GEA, suggesting a greater stress hormone response in this group compared to AEA patients. CONCLUSIONS: Compared to GEA, AEA appears to preserve perioperative NKCC. This effect may be related to an attenuated stress hormone response associated with AEA. Cancer patients may have improved killing of embolized tumor cells during surgery performed under AEA.

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Nonnodulated pea (Pisum sativum L. cv Frosty) and soybean (Glycine max [L.] Merr. cv Wye) plants were grown under artificial lights from germination with ample nutrients, 600 [mu]mol photons m-2 s-1, and either 34 to 36 (control) or 64 to 68 Pa (enriched) CO2. For soybean, pod removal and whole-plant shading treatments were used to alter the source-sink balance and carbohydrate status of the plants. Growth of both species was substantially increased by CO2 enrichment despite some down-regulation of photosynthesis rate per unit leaf area ("acclimation"). Acclimation was observed in young pea leaves but not old and in old soybean leaves but not young. Acclimation was neither evident in quantum yield nor was it related to triose phosphate limitation of net photosynthesis. A correlation between levels of starch and sugars in the leaf and the amount of acclimation was apparent but was loose and only weakly related to the source-sink balance of the plant. A consistent feature of acclimation was reduced ribulose bisphosphate carboxylase (RuBPCase) content, although in vivo RuBPCase activity was not necessarily diminished by elevated growth CO2 owing to increased percentage of activation of the enzyme. A proposal is discussed that the complexity of photosynthetic acclimation responses to elevated CO2 is as an expression of re-optimization of deployment of within-plant resources at three levels of competition.

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The extent to which wheat grain growth is dependent on transport pool solute concentration was investigated by the use of illumination and partial grain removal to vary solute concentrations in the sieve tube and endosperm cavity saps of the wheat ear (Triticum aestivum L.). Short-term grain growth rates were estimated indirectly from the product of phloem area, sieve tube sap concentration, and (32)P translocation velocity. On a per grain basis, calculated rates of mass transport through the peduncle were fairly constant over a substantial range in other transport parameters (i.e. velocity, concentration, phloem area, and grain number). The rates were about 40% higher than expected; this probably reflects some unavoidable bias on faster-moving tracer in the velocity estimates. Sieve tube sap concentration increased in all experiments (by 20 to 64%), with a concomitant decline in velocity (to as low as 8% of the initial value). Endosperm cavity sucrose concentration also increased in all experiments, but cavity sap osmolality and total amino acid concentration remained nearly constant. No evidence was found for an increase in the rate of mass transport per grain through the peduncle in response to the treatments. This apparent unresponsiveness of grain growth rate to increased cavity sap sucrose concentration conflicts with earlier in vitro endosperm studies showing that sucrose uptake increased with increasing external sucrose concentration up to 150 to 200 millimolar.

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Gradients along the transport pathway from the peduncle to the endosperm cavity were examined during grain filling in wheat. Sieve tube exudate was collected from severed aphid stylets established on the peduncle and rachis and on the vascular bundles in the creases of grains. Phloem exudate could also be collected from broken grain pedicels, and by puncturing the vascular bundle in the grain crease with a needle. Stylets on excised grains persisted exuding, indicating that grain sieve tubes are capable of loading solutes. There was little, if any, discernible gradient in osmolality or solute composition (sucrose, total amino acids) of sieve tube contents along the phloem pathway from the peduncle to the rachis or along the rachis itself. Neither was a gradient detected in osmolality along the sieve tube pathway from the rachis through the rachilla and grain stalk to the crease. Demonstrable solute gradients occurred only across those tissues of the grain crease between the crease sieve tubes and the endosperm cavity, a distance of just 1 millimeter. However, while the sucrose concentration in the sieve tubes was almost tenfold that in the endosperm cavity sap, total amino acids were only threefold higher, and the potassium concentrations of the two were equal. Our observations strongly implicate the movement of assimilates from the sieve tubes and across the crease tissues as important control points in grain filling.

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An improved technique is presented for placement of the upper arm graft fistula for hemodialysis. This approach brings the graft anteriorly across the front of the biceps muscle, thereby allowing easier puncture and greater comfort for the patient during dialysis treatment.

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The time-course of sucrose efflux from attached seedcoats (having their embryos surgically removed) into aqueous traps placed in the ;empty ovules' had three phases. The first phase lasted 10 minutes and probably was a period of apoplastic flushing. The second lasted 2 to 3 hours and is thought to be a phase of equilibration of seed coat symplast with the frequently refreshed liquid. The third phase of relatively steady efflux was postulated to reflect the continued import of sucrose from the plant, and hence to reflect the rate of sieve tube unloading. The average steady state efflux was equal under most conditions to the estimated rate of sucrose import. Efflux and import were unaffected by 150 millimolar osmoticum (mannitol or polyethylene glycol [molecular weight about 400]), by 0.5 millimolar CaCl(2), or by pretreatments up to 20 minutes with p-chloromercuribenzenesulfonic acid (PCMBS); they were enhanced by 40 micromolar abscisic acid, 40 micromolar indoleacetic acid, 20 micromolar fusicoccin, and 1 millimolar dithiothreitol (DTT) and were inhibited by 100 micromolar KCN, by 0.03% H(2)O(2), by 20 micromolar and 5 micromolar trifluoromethoxy (carbonyl cyamide) phenylhydrazone, by repeated 5 minutes per hour treatments with 5 millimolar PCMBS, and by 5 millimolar DTT. The ;steady state' sucrose efflux was able to account for about half the rate of dry weight growth of the embryo, but stabilization of the system with <1 millimolar DTT taken together with other considerations is likely to give good correspondence between experimental unloading rates and in vivo growth rates.

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The apoplastic sucrose concentration at the interface between cotyledons and surrounding seed coats of developing soybeans (Glycine max L. Merr. cv Wye) was found by three indirect methods to be in the range of 150 to 200 millimolar. This is an order of magnitude higher than has been reported elsewhere for soybean. It was also higher than the overall sucrose concentrations in the cotyledons and seed coats, each of which was approximately 90 millimolar. By defoliating plants 24 hours before measurement, both the overall sucrose concentration in the cotyledons and the interfacial apoplastic sucrose concentration were reduced by three-fourths. However, there was no day/night difference in overall tissue sucrose concentration of cotyledons or seed coats from intact plants suggesting the existence of a homeostatic mechanism compensating for the diurnal photosynthetic cycle. About 7 hours were required for a tritiated polyethylene glycol-900 solution to fully permeate developing cotyledons (from approximately 220 milligram fresh weight embryos), implying high diffusion resistance through the tissue.These results indicate that a high interfacial sucrose concentration may exist in vivo. They suggest that the saturable carrier-mediated component of sucrose uptake may be of little physiological significance in the outermost cell layers of the cotyledons.

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Leaf photosynthesis rate of the C4 species Paspalum plicatulum Michx was virtually CO2-saturated at normal atmospheric CO2 concentration but transpiration decreased as CO2 was increased above normal concentrations thereby increasing transpiration efficiency. To test whether this leaf response led growth to be CO2-sensitive when water supply was restricted, plants were grown in sealed pots of soil as miniature swards. Water was supplied either daily to maintain a constant water table, or at three growth restricting levels on a 5-day drying cycle. Plants were either in a cabinet with normal air (340 µmol (CO2) mol(-1) (air)) or with 250 µmol mol(-1) enrichment. Harvesting was by several cycles of defoliation.With abundant water supply high CO2 concentration did not cause increased growth, but it did not cause an increase in growth over a wide range of growth-limiting water supplies either. Only when water supply was less than 30-50% of the amount used by the stand with a water-table was there evidence that dry weight growth was enhanced by high CO2. In addition, with successive regrowth, the enhancing effect under a regime of minimal water allocations, became attenuated. Examination of leaf gas exchange, growth and water use data showed that in the long term stomatal conductance responses were of little significance in matching plant water use to low water allocation; regulation of leaf area was the mechanism through which consumption matched supply. Since high CO2 effects operate principally via stomatal conductance in C4 species, we postulate that for this species higher CO2 concentrations expected globally in future will not have much effect on long term growth.

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Measurements of the light environment and stomatal and photosynthetic behaviour are reported for Huon Pine (Lagarostrobos franklinii, family Podocarpaceae) in western Tasmanian rainforest. For a variety of microenvironments, these are used in an analysis of stable carbon isotope measurements in the air, and in branch and leaf material, using a model for carbon isotope fractionation in leaves (Farquhar et al. 1982).The major features of δ13C variations with respect to branch position can be explained in terms of the direct influence of light level acting via the rate of CO2 assimilation. In addition a relatively constant δ13C gradient of about 2.6‰ between leaf tip and branch wood is observed.Alternative explanations are advanced for the tip-towood gradient in δ13C. If the δ13C of leaf tips is taken to represent the value for photosynthate, maintenance respiration is proposed as a mechanism for the further fractionation; a significant 13C depletion in respired CO2 is implied which is not supported by indirect measurements of atmospheric isotope ratio. Furthermore, an assumption of significant sampling errors (e.g. related to humidity effects on assimilation) is required to obtain good quantitative prediction of the light influence.If the branch wood δ13C is taken to represent that of the photosynthate, the tip-to-wood gradient may find an explanation, via the model, in terms of tip tissue comprising carbon from immature cells. Translocation of photosynthate from exposed to shaded branches is then proposed as a means of obtaining quantitative agreement with the predicted light influence.The support provided for the applicability of the Farqunar et al. (1982) model in the field is discussed in the context of the problem of obtaining past global atmospheric CO2 levels from δ13C in tree-rings.

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The photosynthetic basis for increasing the yield of major field crops is examined in terms of improving the interception of seasonal solar radiation by crop foliage, the efficiency of conversion of intercepted light to photosynthetic assimilates, and the partitioning of photoassimilates to organs of economic interest. It is concluded that, in practice, genetic and chemical manipulation of light interception over the season and of partitioning offer the most potential for achieving further increases in yield. During the history of improvement of genetic yield potential of crops, increase in the partitioning of photoassimilates to harvested organs has been of primary importance.

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Ethylene concentrations of CO(2) cylinders from different sources ranged from <0.1 up to 475 microliters per liter. The effect of the higher ethylene concentrations on growth of species in CO(2) enrichment studies was examined. Though maize plants showed no effect on C(2)H(4), growth of tomato, rice, mung bean, and phalaris was substantially reduced by ambient concentrations of ethylene in the range of 0.02 to 0.06 microliters per liter.

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The sensitivity of stomatal conductance to changes of CO(2) concentration and leaf-air vapor pressure difference (VPD) was compared between two C(3) and two C(4) grass species. There was no evidence that stomata of the C(4) species were more sensitive to CO(2) than stomata of the C(3) species. The sensitivity of stomatal conductance to CO(2) change was linearly proportional to the magnitude of stomatal conductance, as determined by the VPD, the same slope fitting the data for all four species. Similarly, the sensitivity of stomatal conductance to VPD was linearly proportional to the magnitude of stomatal conductance. At small VPD, the ratio of intercellular to ambient CO(2) concentration, C(i)/C(a), was similar in all species (0.8-0.9) but declined with increasing VPD, so that, at large VPD, C(i)/C(a) was 0.7 and 0.5 (approximately) in C(3) and C(4) species, respectively. Transpiration efficiency (net CO(2) assimilation rate/transpiration rate) was larger in the C(4) species than in the C(3) species at current atmospheric CO(2) concentrations, but the relative increase due to high CO(2) was larger in the C(3) than in the C(4) species.

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In this paper, experiments are described which examine the effect of requirement for assimilates by the ear on the rate of net photosynthesis in leaves of wheat (Triticum aestivum L.). Different levels of requirement were achieved by various levels of sterilization of florets just before anthesis, which resulted in a range of grain numbers per ear, and by inhibiting photosynthesis of the intact ear by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Only the ear and two uppermost leaves of the main shoot were considered, all the lower leaves and tiller leaves being excised when the experimental treatments were imposed. In two experiments, tiller regrowth was permitted during the experimental period, while in a third, new tillers were defoliated regularly.The response of leaf photosynthesis to the level of assimilate requirement by the ear was influenced by the treatment of the vegetative tillers. Thus, the net photosynthesis rate of the flag leaf was decreased by a reduction in grain number, or increased by inhibition of photosynthesis in the ear, only when the vegetative tillers were kept defoliated; when these tillers were allowed to re-grow normally, there was no influence of ear treatment on leaf photosynthesis. Temporal changes in leaf photosynthesis were consistent with this response pattern, i.e., when tillers were defoliated, the initial high rates of photosynthesis persisted for much longer.In the experiment where photosynthesis was influenced by the requirement for assimilate in the ear, the variation occurred through change in stomatal conductance on the abaxial surface of the leaf. This surface has a lesser conductance to CO2 exchange than the adaxial surface. The implication of this finding to rapid methods of plant screening is discussed.

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It is suggested that, by assigning to every resource use and activity (including childbirth) that causes environmental impact a price in money-independent units (NRU's), a new system of environmental trade-offs can be established-one which maintains maximum personal choice within overall environmental constraint. The social equality of the system in relation to resource exploitation would be enhanced by distributing NRU rations equally among the population each year. Special means of controlling industrial and organizational use of resources through NRU's are also discussed. The system is believed to offer a more sensitive means of gauging social priorities in relation to resource use than that achieved by an exclusively monetary system. Although involving more planning and more governmental regulation than is currently deemed feasible or acceptable, we believe the mechanism would lead to less restriction of personal freedom in a steady-state society than would the current trend toward unsystematic imposition of governmental regulations.