Organogenesis and foetal haemodynamics during the normal gestation of healthy black‐rumped agoutis (Dasyprocta prymnolopha,Wagler, 1831) bred in captivity

The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B‐mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black‐rumped agoutis via B‐mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.     

Effects of single layer centrifugation (SLC) on bull spermatozoa prior to freezing on post‐thaw semen characteristics

Single layer centrifugation (SLC) has been shown to select the most robust spermatozoa from the ejaculate in several species. Here the effects of SLC prior to freezing on various parameters of frozen‐thawed bovine sperm quality are reported. Semen from 8 bulls was layered on top of a species‐specific colloid, Bovicoll. After centrifugation for 20 min at 300 g, the resulting sperm pellet was resuspended in OPTIXcell^® (IMV Technologies, l′Aigle, France); the SLC‐selected sperm samples and uncentrifuged controls were frozen. On thawing, all sperm samples were analysed for membrane integrity, production of reactive oxygen species, mitochondrial membrane potential (MMP) and chromatin integrity. The SLC‐treated samples had a higher percentage of live, superoxide‐positive spermatozoa than uncentrifuged samples (27.9 ± 5.1% versus 21.7 ± 6.7%; p = .03). They had a higher proportion of spermatozoa with high mitochondrial membrane potential than uncentrifuged samples (55.9 ± 8.2% versus 40.5 ± 15.1%; p = .03) and also a lower proportion of spermatozoa with low mitochondrial membrane potential than non‐treated samples (42.0 ± 8.5% versus 55.9 ± 14.4%; p = .04). No significant effects of treatment were found for membrane integrity or chromatin integrity. The effect of bull was significant on the proportions of dead, superoxide‐positive spermatozoa and live, hydrogen peroxide‐negative spermatozoa, as well as on membrane integrity, but it was not significant for mitochondrial membrane potential or chromatin integrity. These results suggest that SLC selects the most metabolically active bull spermatozoa from the rest of the population in normal ejaculates; the pattern of reactive oxygen species production may be different in SLC‐selected spermatozoa compared to unselected samples.     

Development of a bioacoustic sensor for the early detection of Red Palm Weevil (Rhynchophorus ferrugineus Olivier)

The Red Palm Weevil (Rhynchophorus ferrugineus Olivier) is one of the worst pests for palms, since it can completely destroy the plant. Its early detection is very difficult and when the action of the pest is discovered, normally it is too late for recovering the plant. Bioacoustic sensors provide a good alternative for early detection of this pest because larvae activity is audible while they excavate tunnels to feed. This work describes the different stages for the development of an original electronic device based on acoustic sensors for early detection of Red Palm Weevil larvae in the interior of palms. This device is based on characteristic frequencies possibly related to their feeding activity. The performed tests have demonstrated that is possible to detect two week old larvae activity studying the sound intensity around 2250 Hz in palms infested only with 5 individuals under controlled environmental conditions. The activity of other insects artificially situated in the interior of palms did not affect the response of the device, possibly because they produce different frequencies (in the range 5–7 kHz). Future work will be aimed at assessing the infestation levels.     

Reproductive partitioning in sea level quinoa (Chenopodium quinoa Willd.) cultivars

The proportion of growth allocated to reproductive organs can be an important determinant of yield variation between cultivars and environments. The main aim of this paper was to evaluate the adequacy of a model assuming constancy in partitioning coefficients (PC, the slope of organ weight to total weight relationship) within periods whose limits are associated with phenological phases to describe variation in reproductive growth (including seeds when present) in the Andean seed crop quinoa. A second objective was to analyze the dynamics of panicle and stem growth to advance our understanding of factors determining yield in this species. To do this, we used data from two experiments conducted in 2 years under field conditions in the Argentinean pampas, using four cultivars belonging to the Sea Level Type and adapted to temperate environments, under three densities. Reproductive partitioning followed a bi-phasic pattern; panicle biomass increased gradually until reaching a total biomass value, and then there was an increase in the slope of panicle vs. total aerial biomass relationship. Partitioning coefficients for the initial stage varied between some cultivars and densities in the first year, but not in the second. No significant differences were detected when PCs for the second stage were considered. The start of panicle growth was associated with thermal time to first anthesis (R² = 0.62) while thermal time to change in partitioning from low to high PC and that to end of flowering were strongly related (R² = 0.93). Combining data across cultivars, years and densities gave a PC of 0.15 for the initial stage and 0.90 for the second stage. Using these relationships and parameters dynamics of panicle biomass accumulation was predicted satisfactorily in an independent data set for a different environment, confirming the usefulness of a single model approach to describe partitioning across cvs. and environments in this crop. Besides, crop yield estimations improved when compared to those obtained by a seed number estimation model, predictions were only 7.25% lower than observed values compared to −24.5% using a seed number approach. There is a trade-off between final partitioning to reproductive structures (higher in short-cycle cvs.) and total crop biomass, one of the factors contributing to this trade-off being a negative association between the panicle–stem relationship at harvest and duration in thermal time units of stem growth; so, selection for high partitioning rate should be targeted at long duration cvs. within this germplasm.     

RTK GPS mapping of transplanted row crops

This study demonstrated the feasibility of using a real-time kinematic (RTK) global positioning system (GPS) to automatically map the location of transplanted row crops. A positive-placement vegetable crop transplanter retrofitted with an RTK GPS receiver, plant, inclination, and odometry sensors, and an on-board real-time data logger were used for transplant mapping in the field during planting. Sensing the location where each plant was placed in the soil using an absolute shaft encoder mounted on the planting wheel proved to be more robust and accurate than using an infrared light beam sensor to detect the stem location of each plant immediately after planting. Field test results showed that the mean error between the plant map locations predicted by the planting data and the surveyed locations after planting was 2 cm, with 95% of the predicted plant locations being within 5.1 cm of their actual locations. Along-track errors were greater than transverse-track errors indicating that some improvement in plant map accuracy might be obtained by characterization of dynamic planting effects on final plant location. Overall, the system was capable of automatically producing a centimeter-level accuracy plant map suitable for use in precision plant care tasks such as intra-row weed control.     

Dendrometric and dasometric analysis of the bushy biomass in Mediterranean forests

The aim of this study was to define the dendrometric and dasometric parameters of five Mediterranean bushy plant species, to make their environmental assessment and to determine correlations with LIDAR data. The species studied were: Quercus coccifera, Rosmarinus officinalis, Ulex parviflorus, Cistus albidus, and Erica multiflora. We calculated the global form factor for each species so as to be able to determine the volume of the plants by measuring their base diameter and length. The model volume closest to the real volume was the cylinder, which had form factor values of between 0.8 and 2.33. We also studied the evolution of the moisture content of the vegetation after cutting. The initial values were from 20 to 30%, with a dry density of 1 t/m³. We defined an occupation factor to determine the relationship between the real volume occupied by the plants in an area and a model volume (hemisphere, paraboloid, cone, and cylinder). The occupation factor was similar for the five species studied in dm³ of material per m³ of (model) apparent volume: 3.5 dm³/m³ for the cylinder; 12.5 dm³/m³ for the cone; 8.5 dm³/m³ for the paraboloid; and 14.5 dm³/m³ for the hemisphere. These factors enabled us to calculate the biomass contained in an apparent volume of bushes (including materials and hollows) by density. The prediction models tested in this study will thus serve to determine the biomass of a bushy forest area when the Canopy Height Model (CHM) is calculated from LIDAR data.     

Different approaches for modeling grouped survival data: A mango tree study

Interval-censored survival data, in which the event of interest is not observed exactly but is only known to occur within some time interval, occur very frequently. In some situations, event times might be censored into different, possibly overlapping intervals of variable widths; however, in other situations, information is available for all units at the same observed visit time. In the latter cases, interval-censored data are termed grouped survival data. Here we present alternative approaches for analyzing intervalcensored data. We illustrate these techniques using a survival data set involving mango tree lifetimes. This study is an example of grouped survival data.     

The effect of high correlated colour temperature office lighting on employee wellbeing and work performance

Background  

The effects of lighting on the human circadian system are well-established. The recent discovery of 'non-visual' retinal receptors has confirmed an anatomical basis for the non-image forming, biological effects of light and has stimulated interest in the use of light to enhance wellbeing in the corporate setting.     

THE IMPACT OF ORGANIC AMENDMENTS ON FOREST SOIL PROPERTIES UNDER MEDITERRANEAN CLIMATIC CONDITIONS

Restoring the native vegetation is one of the most effective ways to control soil degradation in Mediterranean areas, especially in very degraded areas. In the initial months after afforestation, vegetation cover establishment and soil quality could be better sustained if the soil was amended with an external extra source of organic matter. The goal of this study was to test the effect of various organic amendments on select soil properties [soil organic carbon (SOC), pH, and electrical conductivity (EC)] over a 24‐month period. Four amendments were applied in an experimental set of plots: straw mulching (SM), mulch with chipped branches of Aleppo Pine (Pinus halepensis L.; PM), sheep manure compost (SH), and sewage sludge (RU). Plots were afforested following the same spatial pattern, and amendments were mixed with the soil at the rate 10 Mg ha⁻¹. Organic amendments helped maintain SOC over the initial 6 months after the afforestation. However, only the SM and PM treatments had increased SOC values after 24 months. Decreases in EC were found after the addition of SM, PM, and SH amendments. However, RU increased EC values 24 months after the afforestation. Variations in pH values were not sufficient to establish differences among the various treatments. Furthermore, the results show that forest soils with or without organic amendments responded similarly to the seasonal changes in Mediterranean conditions. Copyright © 2014 John Wiley & Sons, Ltd.     

Deleterious Effects of Progestagen Treatment in VEGF Expression in Corpora Lutea of Pregnant Ewes

The aim of the current study was to determine the possible effects of progestagen oestrous synchronization on vascular endothelial growth factor (VEGF) expression during sheep luteogenesis and the peri‐implantation period and the relationship with luteal function. At days 9, 11, 13, 15, 17 and 21 of pregnancy, the ovaries from 30 progestagen treated and 30 ewes cycling after cloprostenol injection were evaluated by ultrasonography and, thereafter, collected and processed for immunohistochemical evaluation of VEGF; blood samples were drawn for evaluating plasma progesterone. The progestagen‐treated group showed smaller corpora lutea than cloprostenol‐treated and lower progesterone secretion. The expression of VEGF in the luteal cells increased with time in the cloprostenol group, but not in the progestagen‐treated group, which even showed a decrease between days 11 and 13. In progestagen‐treated sheep, VEGF expression in granulosa‐derived parenchymal lobule capillaries was correlated with the size of the luteal tissue, larger corpora lutea had higher expression, and tended to have a higher progesterone secretion. In conclusion, the current study indicates the existence of deleterious effects from exogenous progestagen treatments on progesterone secretion from induced corpora lutea, which correlate with alterations in the expression of VEGF in the luteal tissue and, this, presumably in the processes of neoangiogenesis and luteogenesis.