Limitations to vegetation establishment and growth in biofiltration swales

Limitations to vegetation establishment and abundance in biofiltration swales (also called biofilters or bioswales), vegetated storm-water facilities intended to improve runoff water quality, was studied through field monitoring and greenhouse experimentation. The various environmental factors influencing vegetation and organic litter abundance was investigated in eight bioswales in western Washington state, including three that were retrofitted. A nested 4×4 factorial greenhouse experiment tested the response of four turfgrass species commonly seeded in bioswales to three inundation regimes plus a control. In the greenhouse experiment and in the field, persistent inundation significantly suppressed germination and growth. Field monitoring further revealed that heavy shade overwhelms all other environmental factors. Where light is adequate, vegetation and organic litter biomass is strongly and inversely related to the proportion of time bioswales are inundated above 2.5-cm depth during the driest time of year (summer). For most bioswales, flow velocity and hydraulic loading during storm events appear too large to permit sedimentation of silt and clay particles, even with dense vegetation and abundant organic litter. Thus, herbaceous vegetation abundance may not provide a good indication of bioswale treatment performance, and actual storm-water treatment may be much poorer than is generally anticipated from previous studies.     

Energy budgeting and emergy synthesis of rainfed maize–wheat rotation system with different soil amendment applications

Soil is a non-renewable resource and its preservation is essential for food security, ecosystem services and our sustainable future. Simultaneously, it is a major challenge to substitute non-renewable fossil based resources with renewable resources to reduce environmental load. In order to check soil erosion vis-a-vis degradation of sloppy lands of rainfed maize–wheat rotation system, fertilization with organic manure supplemented with inorganic fertilizers is required. In order to address these issues, substitution of 50% NPK through four organic manures viz. farmyard manure (FYM), vermicompost (VC), poultry manure (PM) and in situ green manuring (GM) of sunnhemp (Crotalaria juncea L.) were evaluated against 100% NPK through inorganic fertilizers and through FYM for energy budgeting and emergy synthesis during 2009–2014. Integrated use of FYM along with 50% NPK fertilizers could maintain the highest energy ratio (7.3), human energy profitability (142.4), energy productivity (0.22 kg MJ⁻¹), and energy profitability (6.3 MJ ha⁻¹) over other treatments. However, GM and inorganic fertilizers on equal NPK basis maintained the highest energy intensiveness (24.61 MJ US $⁻¹) and exhibited higher emergy yield ratio (2.66) and lower emergy investment ratio (0.60) and environmental loading ratio (3.74) which resulted into higher environmental sustainability index (0.71) over other treatments. Fertilization with organic manure (FYM) alone could not compete with other fertilized options to energy budgeting and emergy synthesis except specific energy. The study demonstrated that innovative integrated nutrient management of chemical fertilizers and organic manures particularly FYM for energy budgeting and GM for emergy synthesis may be considered as feasible and environment-friendly options for soil conservation, thereby benefiting a 50% saving on costly chemical fertilizers in non-OPEC countries which import most of its phosphorus and potassium fertilizers.     

Long-term response and recovery to nutrient addition of a partitioned arctic lake

1. To study the bottom‐up linkages in arctic lakes, we treated one side of a partitioned lake with inorganic nitrogen and phosphorus for a 6‐week period each summer for 6 years starting in the summer of 1985. We took a variety of weekly measurements to determine the impact of the nutrient loading on the lake and continued weekly measurements for 2–6 years after the cessation of nutrient loading to observe the recovery of the treated side. The loading rates (2.91 mmol N m^?2 day^?1 and 0.23 mmol P m^?2 day^?1) were five times the calculated loading rates for Toolik Lake, located nearby. 2. In all 6 years of nutrient addition, phytoplankton biomass and productivity were greater in the treated sector than the reference sector. In the first 4 years of nutrient addition there was no flux of phosphorus from the mineral‐rich sediments. This changed in the last 2 years of nutrient addition as phosphorus was released to the lake. 3. The response of the animal community to increased plant production was mixed. One of the four macro‐zooplankton species (Daphnia longiremis) increased in number by about twofold in the first 5 years. However, the copepod Cyclops scutifer showed no response during the treatment phase of the study. The benthic invertebrate response was also mixed. After a 2‐year lag time the snail Lymnaea elodes increased in the treated lake sector but chironomids did not. 4. Ecosystem response to fertilisation was not controlled solely by nutrient addition because phosphorus was not recycled from the sediments until the last 2 years of nutrient addition. Phytoplankton still showed the effects of nutrient addition in the recovery period and the hypolimnion of the treated sector was still anaerobic starting at 6 m in 1996.     

Chronobiological factors for compassion satisfaction and fatigue among ambulatory oncology caregivers

Primary caregivers for victims of chronic illness and or trauma experience both positive and negative emotional consequences. These are broadly classified as compassion satisfaction (CS) and compassion fatigue (CF). Because one of the components of CF, burnout, varies with chronotype and sleep quality, we assessed the influence of chronobiological features on the broader constructs of CS and CF. Responses from primary ambulatory care oncology staff working dayshifts were assessed for potential relationships of chronotype and sleep quality with CS and CF using the professional quality of life scale. These were analyzed further in a multivariate model that included personality and job satisfaction as cofactors. We found that sleep quality was a key contributor to CS development and CF reduction. Morningness was positively linked to CS, but the univariate association was masked in the multivariate model. Job satisfaction (contingent rewards, nature of work and operating procedures) heavily influenced CS and CF development. Agreeableness and openness showed positive correlations with CS and negative with burnout, while emotional stability was linked to reduced CF. While job satisfaction and personality predictably played roles in the development of CS and CF, sleep quality and chronotype contributed significantly to benefits and negative consequences of providing care.     

Potential for Powered Flight Neared by Most Close Avialan Relatives,but Few Crossed Its Thresholds

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A three-step screening procedure to identify the mode of phloem loading in intact leaves

A three-step screening method was developed to identify the mode of phloem loading in intact leaves. Phloem loading of ¹⁴CO₂-derived photosynthate was challenged by p-chloromercuribenzenesulfonic acid (PCMBS) in leaves of dicotyledons with either a symplasmic (type 1, with intermediary cells as companion cells) or apoplasmic (type 2b, with transfer cells as companion cells) minor-vein configuration. Firstly, photosynthate export as the result of phloem loading was measured by collection of phloem exudate from the petiole. The PCMBS had virtually no effect on photosynthate export in representatives of type-1 families (Lamiaceae, Lythraceae, Onagraceae, Saxifragaceae). In contrast, photosynthate export was strongly reduced by PCMBS in representatives of type-2b families (Asteraceae, Balsaminaceae, Dipsacaceae, Linaceae, Tropaeolaceae, Valerianaceae) and type-2b members of polytypical families (Fabaceae, Scrophulariaceae). Secondly, densitometric measurements of leaf autoradiographs demonstrated that the contrast between the mesophyll and the lower-order veins was hardly affected by PCMBS treatment in type-1 species, whereas PCMBS strongly reduced the contrast in type-2b species. Thirdly, separate ¹⁴C-radioassays of vein and mesophyll tissues confirmed this observation. The three-step procedure thus revealed a strong and consistent reduction of phloem loading by PCMBS in type-2b species which was absent in type-1 species. In conclusion, phloem loading in type-2b species occurs via the apoplast and type-1 species execute an alternative — most likely symplasmic — mode of phloem loading.Abbreviations PCMBS p-chloromercuribenzenesulfonic acid - SE/CC-complex sieve element/companion cell complex We gratefully acknowledge the expert help of Dr. Maarten Terlou, Department of Image Processing and Design, University of Utrecht, in carrying out the densitometric measurements.     

Enhanced enzymatic hydrolysis of hydrothermally pretreated empty fruit bunches at high solids loadings by the synergism of hemicellulase and polyethylene glycol

In enzymatic hydrolysis, high lignocellulose loadings are required to obtain high sugar titers. However, the high solids loadings limit enzymatic hydrolysis. In this study, to overcome this limitation, the promoting and synergistic effects of the accessory agents of hemicellulase (i.e., Cellic HTec2) and polyethylene glycol (PEG) 8000 were investigated in the enzymatic hydrolysis of hydrothermally pretreated empty fruit bunches (EFBs). After the optimal addition of Cellic HTec2 and PEG, high enzymatic digestion of the pretreated EFBs was achieved owing to their synergistic effects, even at high solids loadings. For example, the enzymatic digestibility of pretreated EFBs at a 21.7% (w/v) solids loading with 10 FPU of Cellic CTec2/g glucan reached 72.5% when 2.7 mg of Cellic HTec2/g glucan and 62.5 mg of PEG/g glucan were used as the accessory agents. These results suggested that the optimal addition of accessory agents is effective for the enhanced hydrolysis of lignocellulose using even a commercial cellulase preparation.     

Gut loading to enhance the nutrient content of insects as food for reptiles: A mathematical approach

A variety of commercially raised insects are fed to insectivorous reptiles, but information concerning appropriate diets used to feed these insects is limited. In the present study, house crickets (Acheta domesticus adults and nymphs), mealworms (Tenebrio molitor larvae), and silkworms (Bombyx mori larvae) were fed diets containing graded levels of calcium (Ca) and/or vitamin A–nutrients that are low or absent in most insects. Diets and insects were analyzed for moisture, Ca, phosphorus (P), and vitamin A. For adult crickets and cricket nymphs, body Ca and vitamin A concentrations increased in a linear fashion with increasing levels of dietary Ca or vitamin A. Ca concentrations of silkworms also increased in a linear fashion with increasing levels of dietary Ca. For mealworms, body Ca and vitamin A concentrations increased in a nonlinear fashion with increasing levels of dietary Ca or vitamin A. These regression equations, in conjunction with insect nutrient composition, allow for the calculation of the optimum nutrient concentration for gut‐loading diets. Final recommendations were based on National Research Council (NRC) requirements for rats, adjustments for the energy content of the insects, and nutrient overages as appropriate. Gut‐loading diets for crickets (adults and nymphs) should be supplemented to contain the following nutrients, respectively: Ca (51 and 32 g/kg), vitamin A (8,310 and 5,270 µg retinol/kg), vitamin D (300 and 190 µg cholecalciferol/kg), vitamin E (140 and 140 mg RRR‐α‐tocopherol/kg), thiamin (31 and 21 mg/kg), and pyridoxine (20 and 10 mg/kg). Gut‐loading diets for mealworms should be supplemented to contain the following nutrients: Ca (90 g/kg), iron (51 mg/kg), manganese (31 mg/kg), vitamin A (13,310 µg retinol/kg), vitamin D (460 µg cholecalciferol/kg), vitamin E (660 mg RRR‐α‐tocopherol/kg), thiamin (5 mg/kg), vitamin B₁₂ (650 µg/kg), and methionine (29 g/kg). Gut‐loading diets for silkworms should be supplemented to contain the following nutrients: Ca (23 g/kg), iodine (0.7 mg/kg), vitamin D (140 µg cholecalciferol/kg), vitamin E (70 mg RRR‐α‐tocopherol/kg), and vitamin B₁₂ (226 µg/kg). Zoo Biol 22:147–162, 2003. © 2003 Wiley‐Liss, Inc.     

Vacuum level effects on knee contact force for unilateral transtibial amputees with elevated vacuum suspension

The elevated vacuum suspension system (EVSS) has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on knee contact force (KCF) is still unclear. The objective of this study was to investigate the effect of vacuum levels on KCF for unilateral transtibial amputees (UTA) using the EVSS. Three-dimensional gait was modeled for 9 UTA with five vacuum levels (0–20 inHg [67.73 kPa], 5 inHg [16.93 kPa] increments) and 9 non-amputees based on kinematic and ground reaction force data. The results showed that the vacuum level effects were significant for peak axial KCF, which had a relatively large value at 0 and 20 inHg (67.73 kPa). The intact limb exhibited a comparable peak axial KCF to the non-amputees at 15 inHg (50.79 kPa). At moderate vacuum levels (5 inHg [16.93 kPa] to 15 inHg [50.79 kPa]), co-contraction of quadriceps and hamstrings at peak axial KCF was similar for the intact limb, but was smaller for the residual limb comparing with the non-amputees. The intact limb showed a similar magnitude of quadriceps and hamstrings force at 15 inHg (50.79 kPa) to the non-amputees, but the muscle coordination patterns varied between the residual and intact limbs. These findings indicate that a proper vacuum level may partially compensate for the lack of ankle plantarflexor and reduce the knee loading. Of the tested vacuum levels, 15 inHg (50.79 kPa) appears most favorable, although additional analyses with more amputees are suggested to confirm these results prior to establishing clinical guidelines.     

LATITUDINAL VARIATION OF WING:THORAX SIZE RATIO AND WING-ASPECT RATIO IN DROSOPHILA MELANOGASTER

In dipterans, the wing-beat frequency, and, hence, the lift generated, increases linearly with ambient temperature. If flight performance is an important target of natural selection, higher wing:thorax size ratio and wing-aspect ratio should be favored at low temperatures because they increase the lift for a given body weight. We investigated this hypothesis by examining wing: thorax size ratio and wing-aspect ratio in Drosophila melanogaster collected from wild populations along a latitudinal gradient and in their descendants reared under standard laboratory conditions. In a subset of lines, we also studied the phenotypic plasticity of these traits in response to temperature. To examine whether the latitudinal trends in wing:thorax size ratio and wing-aspect ratio could have resulted from a correlated response to latitudinal selection on wing area, we investigated the correlated responses of these characters in lines artificially selected for wing area. In both the geographic and the artificially selected lines, wing:thorax size ratio and wing-aspect ratio decreased in response to increasing temperature during development. Phenotypic plasticity for either trait did not vary among latitudinal lines or selective regimes. Wing:thorax size ratio and wing-aspect ratio increased significantly with latitude in field-collected flies. The cline in wing:thorax size ratio had a genetic component, but the cline in wing-aspect ratio did not. Artificial selection for increased wing area led to a statistically insignificant correlated increase in wing:thorax size ratio and a decrease in wing-aspect ratio. Our observations are consistent with the hypotheses that high wing-thorax size ratio and wing aspect ratio are per se selectively advantageous at low temperatures.