ABSTRACT
The micellization of choline-based anionic surface-active ionic liquids (SAILs) having lauroyl sarcosinate [Sar]-, dodecylsulfate [DS]-, and deoxycholate [Doc]- as counter-ions was investigated in an aqueous medium. Density functional theory (DFT) was employed to investigate the net interactional energy (Enet), extent of non-covalent interactions, and band gap of the choline-based SAILs. The critical micelle concentration (cmc) along with various parameters related to the surface adsorption, counter-ion binding (ß), and polarity of the cores of the micelles were deduced employing surface tension measurements, conductometric titrations and fluorescence spectroscopy, respectively. A dynamic light scattering (DLS) system equipped with zeta-potential measurement set-up and small-angle neutron scattering (SANS) were used to predict the size, zeta-potential, and morphology, respectively, of the formed micelles. Thermodynamic parameters such as standard Gibb's free energy and standard enthalpy change of micellization were calculated using isothermal titration calorimetry (ITC). Upon comparing with sodium salt analogues, it was established that the micellization was predominantly governed by the extent of hydration of [Cho]+, the head groups of the respective anions, and the degree of counter-ion binding (ß). Considering the concentration dependence of the enzyme-SAIL interactions, aqueous solutions of the synthesized SAILs at two different concentrations (below and above the cmc) were utilized as the medium for testing the enzymatic activity of cellulase. The activity of cellulase was found to be â¼7- to â¼13-fold higher compared to that observed in buffers in monomeric solutions of the SAILs and followed the order: [Cho][Sar] > [Cho][DS] > [Cho][Doc]. In the micellar solution, a â¼4- to 5-fold increase in enzymatic activity was observed.
Subject(s)
Cellulase , Choline , Ionic Liquids , Micelles , Water , Ionic Liquids/chemistry , Choline/chemistry , Choline/analogs & derivatives , Cellulase/chemistry , Cellulase/metabolism , Water/chemistry , Thermodynamics , Surface-Active Agents/chemistry , Density Functional TheoryABSTRACT
Cover crops (CC) can improve phosphorus (P) cycling by reducing water related P losses and contributing to P nutrition of a rotational crop. This is particularly important in claypan soils with freeze-thaw cycles in early spring in the Midwest U.S. This 4-year study (2019-2022) examined the impact of CC monoculture and mix of CC species on P losses from a fertilizer application, and determined the P balance in soil compared to no cover crop (noCC). The CC mix consisted of wheat (Triticum aestivum L.), radish (Raphanus raphanistrum subsp. Sativus), and turnip (Brassica rapa subsp. Rapa) (3xCCmix) in 2019 and 2021 before corn, and cereal rye (Secale cereale L.) was planted as monoculture before soybean in 2020 and 2022. The 3xCCmix had no effect on total phosphorus (TP) and dissolved reactive phosphorus (PO4-P) concentration or load in 2019 and 2021. Cereal rye reduced TP and PO4-P load 70% and 73%, respectively, compared to noCC. The variation in soil moisture, temperature, and net precipitation from fertilizer application until CC termination affected available soil P pools due to variability in CC species P uptake, residue decomposition, and P loss in surface water runoff. Overall, the P budget calculations showed cereal rye had 2.4 kg ha-1 greater P uptake compared to the 3xCCmix species which also reduced P loss in water and had greater differences in soil P status compared to noCC. This study highlights the benefit of CCs in reducing P loss in surface runoff and immobilizing P through plant uptake. However, these effects were minimal with 3xCCmix species and variability in crop residue decomposition from different CC species could affect overall P-soil balance.
Subject(s)
Agriculture , Phosphorus , Fertilizers , Soil , Crops, Agricultural , Edible Grain , Zea mays , Secale , WaterABSTRACT
Heavy metal contamination of agricultural fields has become a global concern as it causes a direct impact on human health. Rice is the major food crop for almost half of the world population and is grown under diverse environmental conditions, including heavy metal-contaminated soil. In recent years, the impact of heavy metal contamination on rice yield and grain quality has been shown through multiple approaches. In this review article, different aspects of heavy metal stress, that is uptake, transport, signaling and tolerance mechanisms, are comprehensively discussed with special emphasis on rice. For uptake, some of the transporters have specificity to one or two metal ions, whereas many other transporters are able to transport many different ions. After uptake, the intercellular signaling is mediated through different signaling pathways involving the regulation of various hormones, alteration of calcium levels, and the activation of mitogen-activated protein kinases. Heavy metal stress signals from various intermediate molecules activate various transcription factors, which triggers the expression of various antioxidant enzymes. Activated antioxidant enzymes then scavenge various reactive oxygen species, which eventually leads to stress tolerance in plants. Non-enzymatic antioxidants, such as ascorbate, metalloids, and even metal-binding peptides (metallothionein and phytochelatin) can also help to reduce metal toxicity in plants. Genetic engineering has been successfully used in rice and many other crops to increase metal tolerance and reduce heavy metals accumulation. A comprehensive understanding of uptake, transport, signaling, and tolerance mechanisms will help to grow rice plants in agricultural fields with less heavy metal accumulation in grains.
Subject(s)
Metals, Heavy , Oryza , Soil Pollutants , Biological Transport , Crops, Agricultural , Humans , Metals, Heavy/toxicity , Reactive Oxygen Species , Soil , Soil Pollutants/toxicityABSTRACT
The development of new strategies for thermal stability and storage of enzymes is very important, considering the nonretention of catalytic activity by enzymes under harsh conditions of temperature. Following this, herein, a new approach based on the interfacial adsorption of lysozyme (LYZ) at nanointerfaces of ionic liquid (IL)-based microemulsions, for enhanced thermal stability of LYZ, is reported. Microemulsions (MEs) composed of dialkyl imidazolium-based surface active ILs (SAILs) as surfactants, ILs as the nonpolar phase, and ethylene glycol (EG) as the polar phase, without any cosurfactants, have been prepared and characterized in detail. Various regions corresponding to polar-in-IL, bicontinuous, and IL-in-polar phases have been characterized using conductivity measurements. Dynamic light scattering (DLS) measurements have provided insights into the size distribution of microdroplets, whereas temperature-dependent DLS measurements established the thermal stability of the MEs. Nanointerfaces formed by SAILs with EG in thermally stable reverse MEs act as fluid scaffolds to adsorb and provide thermal stability, up to 120 °C, to LYZ. Thermally treated LYZ upon extraction into a buffer shows enzyme activity owing to negligible change in the active site of LYZ, as marked by retention of microenvironment of Trp residues present in the active site of LYZ. The present work is expected to establish a new platform for the development of novel nanointerfaces utilizing biobased components for other biomedical applications.
Subject(s)
Ionic Liquids/chemistry , Nanotechnology , Temperature , Emulsions/chemistry , Enzyme Stability , Muramidase/chemistry , Particle Size , Surface PropertiesABSTRACT
Surface active ionic liquid (SAIL) induced hydrogelation, in the absence of additives, is important considering the properties of soft-hydrogels that can be utilized in different applications. The present study is concerned with the phase behavior and hydrogelation of a SAIL, 1-hexadecyl-3-methylimidazolium p-toluenesulfonate, [C16mim][PTS]. The obtained information about the phase behavior along with the surfactant like behavior of the SAIL was exploited for effective exfoliation of graphene-flakes from graphite in aqueous medium that remain stable for at least one month. Thus the obtained dispersion of graphene-flakes was subsequently hydrogelated exploiting the observations made from the phase behavior of the SAIL, via entanglement of long worm-like micelles of the SAIL formed at higher concentration. The obtained graphene-flake based hydrogels were found to be equally stable as compared to the blank hydrogel as well as against centrifugation. The low melting point of hydrogel facilitates the extraction of graphene-flakes from the hydrogel matrix by heating and diluting the gel and there is no sign of agglomeration in the extracted graphene-flakes even if the extraction is carried out after a period of three months. The present work is an exemplary study on exfoliation, hydrogelation and extraction of graphene-flakes from a hydrogel, when required, using a SAIL and is expected to provide a new platform for utilization of SAILs for efficient graphene exfoliation and subsequent preparation of functional materials.
ABSTRACT
The complexation of three surface active ionic liquids (SAILs): 1-methyl-3-dodecylimidazolium chloride, [C12mim][Cl], and its amide, 3-(2-(dodecylamino)-2-oxoethyl)-1-methyl-1H-imidazol-3-ium chloride, [C12Amim][Cl], and ester, 3-methyl-1-dodecyloxycarbonylmethylimidazolium chloride, [C12Emim][Cl], functionalized counterparts with sodium carboxymethylcellulose (NaCMC), has been investigated. The behaviour of colloidal systems comprising SAILs and NaCMC at the air-solution interface has been investigated using tensiometry. The formed colloids in the bulk have been characterized for their mobility, surface charge, shape, size and morphology along with their relative hydrophobicity/hydrophilicity and other thermodynamic parameters of interest in different concentration regimes of the SAILs. For this, various techniques such as conductivity, turbidity, dynamic light scattering, ζ-potential, scanning electron microscopy (SEM) and fluorescence measurements have been employed. H-bonding prone SAILs, i.e. [C12Amim][Cl] and [C12Emim][Cl], are found to interact with NaCMC in a contrasting manner as compared to their non-functionalized counterpart. The formed complexes of SAILs and NaCMC have been explored for the one pot preparation of magnetic nano-composites by doping colloids of SAILs and NaCMC with zinc ferrite (ZnFe3O4) nano-particles. The prepared magnetic nano-composites are characterised using X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). It is expected that the present work would offer a new colloidal route for the preparation of SAILs and biopolymer assisted nano-composites along with providing physical insights into the complexation phenomenon.
Subject(s)
Carboxymethylcellulose Sodium/chemistry , Ionic Liquids/chemistry , Magnetite Nanoparticles/chemistry , Nanocomposites/chemistry , Electric Conductivity , Hydrophobic and Hydrophilic Interactions , Molecular Structure , Particle Size , Surface Properties , Thermodynamics , WaterABSTRACT
The complexation behaviour of an imidazolium based ionic liquid surfactant (ILS) 3-methyl-1-dodecylimidazolium chloride, [C12mim][Cl], and its amide and ester functionalized counterparts 3-(2-(dodecylamino)-2-oxoethyl)-1-methyl-1H-imidazol-3-ium chloride, [C12Amim][Cl], and 3-methyl-1-dodecyloxycarbonylmethylimidazolium chloride, [C12Emim][Cl], with a model protein gelatin (G) in aqueous solution has been investigated. Complexation of G with ILSs at the air-solution interface has been monitored by tensiometry, whereas complexation and ILS mediated self-assembly of G-ILS complexes in the bulk have been followed by dynamic light scattering (DLS), zeta-potential measurements, conductivity, and fluorescence techniques. The morphology of different self-assembled architectures has been monitored by scanning electron microscopy (SEM). Different transitions observed from various techniques in different concentration regimes of ILSs have been assigned to the varying extent of complexation and ILS mediated self-assembly of G-ILS complexes. The functionalization of the alkyl chain of the ILS [C12mim][Cl] with an amide ([C12Amim][Cl]) or ester ([C12Emim][Cl]) moiety owing to their additional hydrogen bonding (H-bonding) ability along with rigidity ([C12Amim][Cl]) or flexibility ([C12Emim][Cl]) near the imidazolium head group has been found to exert great influence on their complexation with G. This influence is fashioned as self-assembled structures of G-ILS complexes into discrete large hexagonal sheet-like or near spherical architectures, depending on the concentration and type of functionality of the alkyl chain of ILSs. The thermodynamic forces behind the complexation and self-assembly processes have been monitored by isothermal titration calorimetry (ITC) measurements and are discussed in detail. As both the nature of the ILS and protein (charge and structure) could affect their interactional behavior, the present results are expected to be very useful in deeply understanding the structure-property relationship between the nature of the ILS and proteins, which would be of great importance in the field of functional soft-materials.
ABSTRACT
Amide-functionalized surface active ionic liquids (SAILs), 1-methyl-1-dodecyl piperidinium chloride, [C12APip][Cl]; 1-methyl-1-dodecyl pyrrolidinium chloride, [C12APyrr][Cl]; 1-methyl-3-dodecyl imidazolium chloride, [C12Amim][Cl], and 1-methyl-1-dodecyl morpholinium chloride, [C12AMorph][Cl], have been synthesized, characterized and investigated for thermal stability, and micellization behavior in aqueous medium. The introduction of an amide moiety in the alkyl chain decreased the thermal stability of the functionalized SAILs compared to non-functionalized SAILs bearing a simple alkyl chain. A variety of state of the art techniques, viz. tensiometry, conductometry, steady-state fluorescence, isothermal titration calorimetry (ITC), dynamic light scattering (DLS) and atomic force microscopy (AFM), have been employed to investigate the micellization behavior. Amide-functionalized SAILs have shown much lower critical micelle concentration, cmc, and better surface active properties as compared to homologous non-functionalized SAILs. Steady-state fluorescence has provided information about cmc, aggregation number (Nagg) and polarity of the cybotactic region of the micelles, whereas ITC has provided insights into the thermodynamics of micellization. Furthermore, the size and shape of the micelles have been investigated using DLS and AFM techniques.
ABSTRACT
Kidney transplant candidates with high anti-M-type phospholipase A2 receptor antibody activity may be at increased risk for early postkidney transplant recurrence and allograft loss. Pretransplant treatment to induce serological remission may be warranted to improve allograft survival. In this case report, a patient seeking their third kidney transplant, who lost 2 prior living donor transplants from early recurrent membranous nephropathy, underwent pretransplant treatment for membranous nephropathy with serological remission and no evidence of recurrent disease.
ABSTRACT
Management of immunosuppression in patients with a failing or failed kidney transplant requires a complete assessment of their clinical condition. One of the major considerations in determining immunosuppression is whether or not such an individual is considered a candidate for re-transplantation. Withdrawal of immunosuppression in a re-transplant candidate can result in allosensitization and markedly reduce the chances of a repeat transplant. In this review, we summarize the effects of immunosuppression reduction on HLA sensitization, discuss the impacts of allosensitization in these patients, and explore reduction protocols and future directions. Risks of chronic immunosuppression, medical management of the failing allograft, and the effect of nephrectomy are covered elsewhere in this issue.
ABSTRACT
Microemulsions (µEs), comprising water as polar component, pluronic (normal, L35 and reverse, 10R5) as surfactant and a hydrophobic ionic liquid (HIL) as non-polar component have been prepared and characterized. Owing to higher surface activity, pluronics have promoted the formation of µEs without the use of co-surfactant. Thus prepared µEs have been utilized as nano-reactors for the oxidation of guaiacol in the presence of Cytochrome-c (Cyt-c) at 15, 20, and 25 °C. A 3.2- and 1.3-fold increase in the rate of formation of product of enzymatic catalysis in direct µE (HIL-in-water) with reverse pluronic (10R5) is observed at 15 and 20 °C as compared to that in buffer. However, negligible enzymatic activity is observed in the direct µE formed by normal pluronic (L35). The catalytic activity of Cyt-c decreases in reverse µEs (water-in-HIL) as compared to direct µEs irrespective of the nature of pluronic used. The contrasting nature of nano-interfaces formed by pluronics in µEs and the extent of hydration of these nano-interfaces controlled by temperature exerts varying influence on the catalytic activity of Cyt-c. It is expected that the present work would result in providing a versatile platform for the creation of new IL and pluronic-based µEs for bio-catalytic applications, which have never been reported.
Subject(s)
Ionic Liquids , Poloxamer , Poloxamer/chemistry , Ionic Liquids/chemistry , Cytochromes c/chemistry , Water/chemistry , Surface-Active Agents/chemistryABSTRACT
Gliadin, a major component of gluten, is known to trigger celiac disease; therefore, its extraction is important to study its properties as well as its presence in gluten-free products. Four gliadin extraction procedures Osborne (1924), Weiss (1993), Wallace (1989) and DuPont (2005), were investigated on six wheat cultivars using advanced analytical techniques such as dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Higher zeta potential of extracted gliadin was observed in DuPont (23.53-27), followed by Weiss (16.17-20.80), Osborne (16.17-20.13), and Wallace (14.60-19.47). Particle Z-average size (15.74-184.83 nm) was found to have an inverse relationship with the Polydispersity index (0.17-184.83). The surface morphological structure of TEM studies revealed the compact globular particle arrangement of gliadin, besides rod-shaped arrangement, was also found in DuPont and Wallace extracted gliadin. XRD pattern of gliadin exposed the crystalline domain at 44.1°, 37.8°, and 10.4° diffraction peaks. The d-spacing obtained from XRD and TEM-SAED analysis supports the presence of crystalline domains in gliadin apart from the amorphous domain. The insight obtained from this work will provide a better understanding of morphology and other properties of the same protein extracted with different extraction procedures.
Subject(s)
Gliadin/chemistry , Gliadin/isolation & purification , Triticum/chemistryABSTRACT
Expansion of subsurface drainage into forage production may have a deleterious effect on surface waters due to increased nitrogen and phosphorus loading. The impact of controlled subsurface drainage (CD) on nitrogen and phosphorus loss compared with free subsurface drainage (FD) in tile drainage water has been explored to a lesser extent from forage production systems. This study quantifies the effects of CD and FD on average seasonal concentrations and cumulative loads of the total suspended solids (TSS), nitrate nitrogen (NO3 -N), and dissolved reactive phosphorus (DRP) in subsurface drainage water from a poorly drained floodplain soil in a cereal rye (Secale cereale L.)-sorghum [Sorghum bicolor (L.) Moench] rotation with rotational cattle grazing. During all crop seasons of sorghum production (2010-2013), CD had 6.03-9.63 mg L-1 less NO3 -N than FD. Mean DRP concentration was significantly higher for CD than for FD during all seasons except for sorghum in 2012-2013. Average cumulative discharge was 38 and 314 m3 ha-1 less for CD than for FD during sorghum and cereal rye growing seasons, respectively. Controlled drainage had 0.68-6.14 kg ha-1 lower cumulative NO3 -N loads than FD. The DRP loads were dependent on discharge. During sorghum growing seasons, TSS and DRP loads were 79-90% lower in CD compared with FD. The ability to reduce drainage water flow from tiles and subsequent nitrogen and phosphorus loading with CD compared with FD in a floodplain soil indicates that CD can be effective best management practice for forage production systems.
Subject(s)
Agriculture , Soil , Animals , Cattle , Nitrogen , Nutrients , PhosphorusABSTRACT
Temporo-mandibular joint (TMJ) ankylosis is a common cause of acquired mandibular deformity in children and adults. It causes reduced mouth opening and limitation of functional movements resulting in mandibular growth impairment leading to mandibular retrognathism and facial asymmetry. The treatment of TMJ ankylosis is challenging, not only due to the complexities involved and the risk of relapse but also because it requires a high degree of patient cooperation. The treatment may be performed in 1 or 2 phases consisting of the initial release of ankylosis with or without condylar reconstruction, followed by a correction of mandibular hypoplasia and of facial asymmetry by orthognathic surgery. Distraction osteogenesis has been proposed to treat cases with severe deformity due to its inherent advantages of generating new bone and soft tissue. This case report describes the staged treatment of a patient with unilateral TMJ ankylosis. The patient presented with significant facial deformity due to mandibular retrognathism and facial asymmetry as a consequence of impaired growth. The treatment objectives included releasing ankylosis to establish mouth opening, addressing the dentofacial deformity and achieving a normal occlusion. The patient was treated with a combined surgical-orthodontic approach including distraction osteogenesis. The case was treated with a rigid external distractor and CBCT generated facial models were used to plan and execute adjunctive surgeries. The staged treatment approach resulted in a significant improvement of facial aesthetics.
Subject(s)
Mandible/surgery , Osteogenesis, Distraction/methods , Temporomandibular Joint Disorders/surgery , Adolescent , Ankylosis/surgery , Cone-Beam Computed Tomography , Facial Asymmetry/surgery , Humans , Male , Micrognathism/surgery , Temporomandibular Joint Disorders/diagnostic imagingABSTRACT
Herein we report a facile and sustainable method for the preparation of ZnS@graphene nano-composites (NCs). An appreciable amount of graphene is obtained by liquid-phase exfoliation using a zinc-containing surface active ionic liquid (SAIL). It is followed by in situ preparation of ZnS quantum dot (QD) decorated graphene sheets at room temperature for the first time. The employed method is distinct from all previous reports, as we have employed graphene instead of graphene oxide (GO) or reduced graphene oxide (rGO) and used relatively fewer chemicals. Further, a SAIL is employed as a precursor of Zn2+ as well as a template for the preparation of ZnS QDs onto graphene. The prepared ZnS@graphene NCs show enhanced photocatalytic performance for the degradation of Rhodamine B dye under sunlight and ciprofloxacin antibiotic under visible light as compared to bare ZnS QDs. The better photocatalytic activity of the NCs under visible light compared to that reported in the literature along with the ease of preparation is advantageous for scaling-up the process.
ABSTRACT
The nature of functionalization of alkyl chains of imidazolium-based surface active ionic liquids (SAILs) with amide or ester moiety led to contrasting complexation behavior toward the globular protein, bovine serum albumin. This prompted us to further investigate the SAIL-dependent colloidal behavior of another globular protein, ß-lactoglobulin (ßLG), to probe the origin of varying structural transformations in globular proteins induced by SAILs. Herein, we investigated the colloidal systems of ßLG, rich in ß-sheet structure, in the presence of four structurally different SAILs using a multitechnique approach. The complexation behavior, both at the air-solution interface and in bulk, is supplemented by different techniques. Docking studies have complemented the obtained experimental results. The specificity of structure, H-bonding ability of SAILs, and inherent structure of protein are found to govern their complexation behavior in terms of size, shape, and polarity of protein-SAIL complexes along with varying degrees of structural alterations in globular proteins. The present work is expected to be very useful in establishing a deep understanding of the structure-property relationship between the nature of proteins and SAILs for their complexation and colloidal behavior for various biomedical applications.
Subject(s)
Ionic Liquids/metabolism , Lactoglobulins/metabolism , Surface-Active Agents/metabolism , Colloids/chemistry , Hydrophobic and Hydrophilic Interactions , Ionic Liquids/chemistry , Lactoglobulins/chemistry , Molecular Docking Simulation , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Static Electricity , Surface-Active Agents/chemistry , ThermodynamicsABSTRACT
Over the past four decades, riparian buffers have proven effective in retaining nutrients and sediment from agricultural runoff. Many grass species have been used with variable success in riparian buffers to improve the water quality of runoff. However, limited information is available on the effectiveness of giant cane [ (Walt.) Muhl] in improving surface water quality compared with grass species such as Kentucky bluegrass ( L.) and orchardgrass ( L.). Therefore, the objective of our study was to determine the quality of runoff leaving vegetative buffer plots planted with giant cane, Kentucky bluegrass, and orchardgrass. Additionally, a bare-ground control and continuous corn ( L.) was also monitored for comparison of runoff with vegetative buffers. The giant cane treatment had significantly greater infiltration rates (38.18 mm h, < 0.05) than bare ground (1.61 mm h), corn (5.75 mm h), Kentucky bluegrass (12.30 mm h), and orchardgrass (4.21 mm h) treatments. Dissolved reactive P in runoff was ranked as follows: corn > giant cane = Kentucky bluegrass = orchardgrass > bare ground. The total P from the corn treatment (1.70 mg L, < 0.05) was significantly higher than for bare ground (1.22 mg L), giant cane (0.69 mg L), Kentucky bluegrass (0.86 mg L), and orchardgrass (0.54 mg L). Giant cane, Kentucky bluegrass, and orchardgrass significantly reduced the total P concentration more than bare ground and corn. Results from this study demonstrate the utility of giant cane as a vegetated buffer to reduce nutrient and sediment concentrations in agricultural runoff.
Subject(s)
Agriculture , Biodegradation, Environmental , Non-Point Source Pollution/prevention & control , Rivers , Non-Point Source Pollution/analysisABSTRACT
Corn ( L.) production in poorly drained claypan soils in the US Midwest is a challenge due to low soil permeability, which may result in wetter soil conditions and relatively large amounts of soil NO emissions early in the growing season. The objectives of this study were to determine the effects of urea fertilizer placement with and without nitrapyrin (NI) on daily and cumulative soil NO emissions, and yield-scaled NO emissions in 2016 and 2017. Treatments included urea deep banded to a 20-cm depth (DB), urea deep banded to 20 cm plus NI (DB+NI), urea incorporated after a surface broadcast application to â¼8-cm depth (IA), urea broadcast on the soil surface (SA), and a nonfertilized control (NTC). Fertilizer was applied at 202 kg N ha. Surface soil NO efflux rates were generally lower (<50 g NO-N ha d) during the first 3 wk after N fertilization and latter parts of the growing seasons. When averaged across the 2016 and 2017 growing seasons, all fertilized treatments had significantly greater (2.33-5.60 kg NO-N ha, < 0.05) cumulative soil NO emissions than NTC. The DB+NI treatment had 54 and 55% lower cumulative soil NO emissions than IA and SA, respectively. In 2017, DB+NI had similar soil yield-scaled NO emissions to NTC. Percentage grain yield increase over NTC was highest for DB and DB+NI. Grain yield in 2016 was 14 to 18% higher for DB and DB+NI than SA. Results suggest that DB+NI is an effective management strategy for reducing cumulative soil NO emissions and increasing grain yields over the growing season.
Subject(s)
Nitrous Oxide , Soil , Fertilizers , Picolines , UreaABSTRACT
Autumn olive ( Thunb.) is an invasive and exotic N-fixing plant species found throughout the United States. Proliferation and spread of autumn olive have displaced native plants and raised concerns about the effects of N fixation and cycling on water quality in invaded areas. This study investigated the relationship between autumn olive cover and stream N concentrations. Twelve forested watersheds were selected and classified into edge, mid-distance, and interior-of-the-forest watersheds based on autumn olive density and distance from the permanent edge of invasion point along a major road corridor. For the 2012 vegetation survey, autumn olive cover in edge, mid, and interior watersheds ranged from 37 to 61%, 18 to 37%, and 4 to 10%, respectively. From 2006 to 2012, mean stream water NO-N concentration in the edge watersheds was significantly higher (1.39 mg L, < 0.0001) than mid (0.37 mg L) and interior (0.27 mg L) watersheds. A linear relationship was found between NO-N concentration and autumn olive cover ( = 0.72, = 0.0001). Mean stream water NH-N, specific conductivity, and pH were significantly less in the interior watersheds than in the edge watersheds. Additionally, peak specific conductivity and NO-N from edge watersheds coincided with peak stage for these watersheds, demonstrating that N flushing events were driven by surface and shallow subsurface flow pathways proximal to the stream. Results from this study demonstrate how encroachment of autumn olive can influence water quality and transform biogeochemical cycles in natural systems, which points to the need for effective management of autumn olive in the edge watersheds and riparian zones that are vulnerable to invasion and increased N export.
Subject(s)
Olea , Rivers , Forests , Nitrogen , Water QualityABSTRACT
The inner membrane complex (IMC) is a defining feature of apicomplexans comprising of lipid and protein components involved in gliding motility and host cell invasion. Motility of Plasmodium parasites is accomplished by an actin and myosin based glideosome machinery situated between the parasite plasma membrane (PPM) and IMC. Here, we have studied in vivo expression and localization of a Plasmodium falciparum (Pf) IMC protein 'PfIMC1l' and characterized it functionally by using biochemical assays. We have identified cytoskeletal protein 'actin' and motor protein 'myosin' as novel binding partners of PfIMC1l, alongside its interaction with the lipids 'cholesterol' and 'phosphatidyl-inositol 4, 5 bisphosphate' (PIP2). While actin and myosin compete for interaction with PfIMC1l, actin and either of the lipids (cholesterol or PIP2) simultaneously bind PfIMC1l. Interestingly, PfIMC1l showed enhanced binding with actin in the presence of calcium ions, and displayed direct binding with calcium. Based on our in silico analysis and experimental data showing PfIMC1l-actin/myosin and PfIMC1l-lipid interactions, we propose that this protein may anchor the IMC membrane with the parasite gliding apparatus. Considering its binding with key proteins involved in motility viz. myosin and actin (with calcium dependence), we suggest that PfIMC1l may have a role in the locomotion of Plasmodium.