The uptake of Sr and Cs by 2 types of aluminum pillared layered clays (Al-PILC), a reference sample (AZA) and a specially tailored sample (FRAZA), were investigated. The AZA sample was prepared from air-dried precursors and the FRAZA sample from freeze-dried precursors. X-ray diffraction (XRD), pore and grain size measurements revealed that freeze-drying leads to a very fine-grained material with substantial mesoporosity. In contrast, air-drying results in coarse grains and an essentially microporous material. Four different methods were tested for restoring the cation exchange capacity (CEC) of the prepared PILCs. The most effective method proved to be exposing the material to ammonia fumes, then soaking it in a NaCl solution at pH =10. Strontium and Cs kinetic experiments were carried out with PILCs after restoring their CEC by this method. The results revealed 1 fast uptake component in both materials but with different relaxation times for each PILC.

A personal reflection on the experience of introducing Latin to the curriculum. School S. (non-selective, secondary) introduced Latin as a timetabled subject at Key Stage 3 between 2016 and 2019. This is a case study and personal reflection from the teacher who instigated and taught the course, comprising the extracurricular efforts which paved the way for the class, methodological considerations, an evaluation of the project, and the reasons why Latin was ultimately discontinued from the curriculum.

It has been suggested that low serum cholesterol interferes with brain serotonergic functioning, which results in increased suicidal and aggressive tendencies. To test this hypothesis we investigated the relationship between serum cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglyceride levels, and serotonin uptake by blood platelets in 17 healthy men aged 39.5 ± 10.2 years. Platelet serotonin uptake and serum lipids were assayed concomitantly for each individual. Serum cholesterol levels and other serum lipid levels did not correlate with serotonin uptake by platelets at the concentration of 2 × 10−5 M (a concentration within the maximal uptake capacity range). The results indicate no influence of cholesterol on serotonin uptake, as opposed to some investigators who suggested that high risk of suicide and aggressiveness in hypocholesterolemic individuals is related to impaired serotonin transport.

Within the NHS health check (NHSHC) programme, there is evidence of marked inconsistencies and challenges in practice-level self-reporting of uptake. Consequently, we explored the perceptions of those involved in commissioning of NHSHC to better understand the implications for local and national monitoring and evaluation of programme uptake. Semi-structured, one-to-one, telephone interviews (n=15) were conducted with NHSHC commissioners and leads, and were analysed using inductive thematic analysis. NHSHC data were often collected from practices using online extraction systems but many still relied on self-reported data. Performance targets and indicators used to monitor and feedback to general practices varied between localities. Participants reported a number of issues when collecting and reporting data for NHSHC, namely because of opportunistic checks. Owing to the perceived inaccuracies in reporting, there was concern about the credibility and relevance of national uptake figures. The general practice extraction service will be important to fully understand uptake of NHSHC.

Bryophytes are usually taken as good bioindicators. However, they represent a large group of terrestrial plants and they express an enormous range of peculiarities within the plant kingdom. With the aim to search for a common pattern of zinc binding, we established axenical in vitro cultures of a dozen bryophyte species that include hornworts, thallose, and leafy liverworts, as well as acrocarp and pleurocarp mosses. The species were grown free of contaminants for many years prior to the application of different treatments, i.e. offering Zn(II) from solid and liquid media and in combination with different anions. The localization and binding of zinc was detected by confocal microscopy using the zinc-specific dye FluoZin™-3. In one of the species, Hypnum cupressiforme (which is widely used for atmospheric heavy metal deposition studies in biomonitoring), semi-quantitative analyses of zinc were performed by energy dispersive X-ray microspectrometry (EDX) in a scanning electron microscope. The results suggest no common pattern of Zn(II) binding in different bryophyte species. Instead, the binding pattern seems to be species specific. Zinc is located in certain areas or cellular compartments, as clearly shown by the EDX measurements in H. cupressiforme.

Acifluorfen tolerance in eastern black nightshade somaclones was characterized in two experiments. One experiment determined the involvement of absorption, translocation, and metabolism in acifluorfen tolerance. Less than 6% of the applied 14C-acifluorfen was absorbed. There were no differences in acifluorfen absorption between susceptible and tolerant somaclones. More 14C-acifluorfen was translocated in the susceptible than the tolerant somaclones. The susceptible somaclone did not metabolize acifluorfen while some somaclones (i.e., EBN-3A) metabolized 14C-acifluorfen. A second experiment determined the tolerance of the somaclones to oxyfluorfen, diquat, and paraquat Most acifluorfen-tolerant somaclones were tolerant to oxyfluorfen but were susceptible to diquat and paraquat One somaclone, EBN-3A, was extremely tolerant to acifluorfen, paraquat, and diquat.

Research was conducted to determine foliar absorption of 14C-clethodim and its polar degradation products with five adjuvants and to compare the relative herbicidal activity of clethodim and its polar degradation products. Differential 14C-clethodim and 14C-polar degradation products absorption occurred among the five adjuvants. Adjuvants that mediated rapid foliar absorption of clethodim did not always mediate rapid foliar uptake of polar degradation products. Herbicidal activity of clethodim exceeded activity of polar degradation products regardless of time of day of application or whether adjuvant was used. Inclusion of adjuvant was required for herbicidal activity of polar degradation products. Clethodim activity declined when applied at 0800 h EDT compared to applications at 2000 h EDT. To maximize herbicidal activity of clethodim, adjuvants should be selected that mediate rapid foliar absorption of both clethodim and the polar degradation products of clethodim and that minimize photodegradation of clethodim.

Greenhouse and laboratory experiments were conducted to determine the effect of DPX-PE350 on the herbicidal activity of fluazifop-P on large crabgrass. Greenhouse experiments indicated that fluazifop-P activity was antagonized by DPX-PE350. This antagonism was reduced by increasing fluazifop-P rates or by applying DPX-PE350 after fluazifop-P. Applying DPX-PE350 24 h prior to fluazifop-P reduced fluazifop-P activity more than applying it 10 min prior. The effect of DPX-PE350 application to large crabgrass on extractable acetyl-CoA carboxylase activity, and the effect of DPX-PE350 on acetyl-CoA carboxylase activity in vitro also was studied. Applying DPX-PE350 to large crabgrass prior to protein extraction did not reduce fluazifop-P inhibition of acetyl CoA carboxylase activity in vitro. The presence of DPX-PE350 in the enzyme assay mix did not affect fluazifop-P inhibition of acetyl-CoA carboxylase activity. The effect of DPX-PE350 on uptake, translocation, and metabolism of fluazifop-P was considered. DPX-PE350 did not affect uptake of fluazifop-P by large crabgrass. Applying DPX-PE350 24 h prior to fluazifop-P decreased translocation of fluazifop-P out of the treated leaf 44 to 53% whereas mixing DPX-PE350 with fluazifop-P decreased fluazifop-P translocation only 15 to 17%. Metabolism of fluazifop-P was not affected by applications of DPX-PE350. These studies suggest that the antagonism of fluazifop-P activity by DPX-PE350 is due to decreased translocation of fluazifop-P out of the treated leaf.

Greenhouse-grown soybean cultivars varied in their tolerance to preemergence application of sulfentrazone. The cultivars Ransom, Hutcheson, Kato, Gasoy 17, and Cobb exhibited relatively low tolerance to 0.5 kg ai ha−1 sulfentrazone with 38, 41, 46, 50, and 58% height reduction compared to respective controls. The growth of tolerant cultivars Centennial, Edison, and Hartz 5164 was not affected by this treatment. However, the growth of all cultivars was reduced at the excessive rate of 2.0 kg ha−1 preemergence application of sulfentrazone. No differences in root uptake or translocation of [14C] sulfentrazone were observed between the relatively tolerant and less tolerant cultivars tested. Centennial and Hutcheson cultivars rapidly metabolized sulfentrazone via oxidative degradation of the 3-methyl group on the triazolinone ring of the herbicide. Only 4.7 and 4.9% of the active ingredient remained in the foliage of Hutcheson and Centennial 24 h after treatment, respectively. While there were no differences in Protox inhibition or Proto IX accumulation between the two cultivars, Hutcheson was more sensitive than Centennial to peroxidative stresses induced by either Proto IX accumulation or rose bengal. Therefore, tolerance to sulfentrazone is due to rapid metabolism of the herbicide; however, the intraspecific difference in response to sulfentrazone appears to be due to intrinsic differential tolerance to the herbicide-induced peroxidative stress.

The joint action of metribuzin and tridiphane was investigated in metribuzin-tolerant (T) and metribuzin-susceptible (S) soybean and tomato cultivars within species, respectively, under growth room studies. Maple Arrow (T) and Maple Amber (S) exhibited similar tolerance to tridiphane applied at soybean emergence. Vision (T) tomato was more sensitive to tridiphane than was Springset (S) tomato, the reverse of the relative tolerance to metribuzin. A phytotoxic interaction was demonstrated following application of tridiphane and metribuzin at the respective rates (kg ai ha−1) of 0.1 and 1.1 in Maple Arrow (T) soybeans, 0.05 and 0.25 in Maple Amber (S) soybeans, and 0.25 and 0.2 in Springset (S) tomato. Tridiphane applied 1 or 4 h before metribuzin caused the greatest phytotoxicity in Maple Amber (S) soybeans. Soybean field results generally supported those of growth-room studies. Foliar spray pretreatment with tridiphane increased total radioactivity in Springset (S), decreased the total root radioactivity and increased total shoot radioactivity in both Vision (T) and Springset (S) and decreased metabolism of metribuzin to water soluble conjugates in Springset (S) roots over 24 h following 14C-metribuzin application to roots of intact tomato seedlings. The increased uptake, translocation to the shoots, and decreased root metabolism of metribuzin in Springset when pretreated with tridiphane could explain the phytotoxic interaction (which was unexpected, based only on the glucose detoxification pathway of metribuzin in tomato).

Applications of isopropylamine glyphosate at 0.28, 0.56, 0.84, and 1.12 kg ae/ha in combination with the dimethylamine salts of 2,4-D or dicamba at 0.14, 0.28, 0.42, and 0.56 kg ae/ha produced additive or synergistic field bindweed control compared to the herbicides applied alone. Leaf and root growth was inhibited more from herbicide combinations than would be predicted from the effects of the chemicals applied alone at the same rate. The uptake of 14C from glyphosate into the treated leaf and its accumulation in roots increased when 2,4-D or dicamba was combined with the 0.28 kg/ha rate of 14C-glyphosate. The combination of 2,4-D or dicamba with a higher (0.84 kg/ha) 14C-glyphosate rate did not change total absorption of 14C from glyphosate. However, compared to 0.84 kg/ha of 14C-glyphosate applied alone, less 14C accumulated above the treated leaf and more accumulated in the roots when 2,4-D was added to the glyphosate. The combination of glyphosate with 2,4-D or dicamba generally resulted in both increased uptake of 14C from 2,4-D or dicamba and greater accumulation in the roots. The additive or synergistic field bindweed control observed from mixtures of glyphosate with 2,4-D or dicamba appeared to be due to greater accumulation of the herbicides in the roots.

Napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide]-binding in excised root segments of corn (Zea mays L. ‘NC + 59′) was confined to cell wall fractions (residue and 500 g pellet) remaining after homogenization and to components of the 100 000 g supernatant. Binding increased in both the cell wall and soluble fractions with continued exposure to napropamide. Microautoradiographs revealed that the napropamide bound in the cell walls was located in epidermal, cortical, and stelar tissue. Various proteins were capable of binding napropamide in vitro; however, protease treatment did not liberate the radioactivity bound in the cell wall fragments. Carbohydrate release from the cell wall material with cellulase was not correlated with the solubilization of bound radioactivity and wall carbohydrate monomers did not appear to bind to napropamide in vitro. A portion of the radioactivity found in the soluble components (at 100 000 g) was associated with a molecule of MW > 600. The continued influx of napropamide was due to binding to cell wall components and molecules within the cell.

Tissue and cell culture offer weed scientists many opportunities to research herbicide effects on plants. This review will discuss examples in which plant cells grown in vitro have been used to study herbicide action. Plant cell and tissue culture have many advantages over the use of whole plants; however, several disadvantages that exist are discussed. Cell cultures can be established for most plant species and provide a relatively homogeneous system for studying herbicide action. Responses of plant cells to herbicides are usually correlated with responses at the whole plant level, and cells have the advantage of posing fewer physical barriers to herbicide uptake and translocation. Cell culture techniques discussed include: screening candidate herbicide compounds; investigating herbicide efficacy, mechanism of action, metabolism, and uptake; and ascertaining mechanisms of herbicide resistance, selecting for resistance, and regenerating crops.

Use of glyphosate in controlling Orobanche aegyptiaca (broomrape), a parasitic weed on dicotyledonous crops, was examined by determining glyphosate dose response and 14C-labeled glyphosate absorption, translocation, and metabolism patterns in Vicia sativa (common vetch) that is tolerant of low levels of glyphosate and Brassica napus (oilseed rape) that has been genetically engineered to be glyphosate resistant. Glyphosate provided excellent suppression of O. aegyptiaca growth in both V. sativa and B. napus. Absorption and translocation of 14C-glyphosate was similar between parasitized and nonparasitized V. sativa plants. 14C-Glyphosate was metabolized up to 32% in V. sativa, which could account for some of the tolerance of V. sativa to glyphosate. Approximately 27% of translocated 14C-glyphosate accumulated in O. aegyptiaca attachments on V. sativa. Absorption and translocation patterns of 14C-glyphosate were similar between parasitized and nonparasitized B. napus plants. Nearly one-third (31%) of the translocated radioactivity was found in O. aegyptiaca attachments on B. napus. No metabolism of 14C-glyphosate was detected in B. napus.

Retention, absorption, translocation, and volatility of foliarly applied diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy) phenoxy] propanoate} were compared in barnyardgrass [Echinochloa crus-galli (L.) Beauv.], a susceptible grass; proso millet (Panicum miliaceum L.), a moderately susceptible grass; longspine sandbur [Cenchrus longispinus (Hack.) Fern.], a tolerant grass; and soybean [Glycine max (L.) Merr. ‘Hark’] and cucumber (Cucumis sativus L. ‘Green Star’), both tolerant broadleaf plants. On a jug/plant basis, the order of diclofop-methyl spray retention was cucumber > soybean > proso millet > longspine sandbur = barnyardgrass. On a μg/mg dry weight basis, proso millet retained 3 to 10 times more diclofop-methyl than all other species. One day after treatment (DAT), absorption of 14C-diclofopmethyl was 14 to 18% less in longspine sandbur than in the other species, 3 DAT absorption in cucumber was 8 to 14% greater than in the other species, and 5 DAT absorption in soybean was 3 to 12% less than in other species. Translocation of 14C-diclofop-methyl did not differ among species, with 98% of the applied radioactivity located in the treated leaf. An average of 11% of radioactivity applied to the surface of intact, living plants and excised, dried leaves of cucumber, soybean, and barnyardgrass, as well as glass cover slips, was lost by evaporation. None of the parameters measured showed differences large enough to be implicated as primary selectivity mechanisms.

Diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate} loses part of its activity on wild oats (Avena fatua L.) when it is applied in combination with ester or amine formulations of MCPA {[4-chloro-o-tolyl)oxy] acetic acid.} Uptake of diclofop-methyl is reduced in the presence of commercial formulations of MCPA, particularly amine formulations, which are only partly compatible with the diclofop-methyl formulation. With added MCPA, regardless of formulation, hydrolysis of diclofop-methyl to the acid diclofop is slowed down, both in intact wild oat plants and in a crude leaf extract. At the same time, conversion of any acid formed to inactive conjugates is accelerated in the presence of MCPA. It is concluded that the loss of activity of diclofop-methyl by MCPA can be accounted for by the effects of MCPA on uptake and metabolic conversion of diclofop-methyl.

Hemp dogbane is sensitive to fluroxypyr and tolerant to clopyralid. Absorption, translocation, and metabolism of clopyralid and fluroxypyr were studied in hemp dogbane to determine if differences in these processes could be responsible for differential sensitivity. In addition, the effect of growth stage on herbicide absorption and translocation was evaluated. The 14C-herbicides were applied to the adaxial side of a single leaf located near the midpoint of hydroponically cultured plants. Uptake of fluroxypyr was more rapid than clopyralid. At 72 h after treatment (HAT), fluroxypyr and clopyralid absorption was 62 and 38%, respectively. Clopyralid was much more mobile than fluroxypyr, with 75% of the absorbed 14C from 14C-clopyralid recovered outside the treated leaf compared to only 45% for fluroxypyr 72 HAT. Relative to fluroxypyr, a higher percentage of 14C-clopyralid recovered outside the treated leaf translocated acropetally, especially when plants were treated during the vegetative stage. Treatment during the early reproductive stage increased basipetal and reduced acropetal translocation relative to the vegetative stage. Neither herbicide was metabolized rapidly. Approximately 60 and 90% of the recovered 14C was attributable to unaltered fluroxypyr and clopyralid, respectively, 72 HAT. Some differences in absorption, translocation, and metabolism between clopyralid and fluroxypyr exist, but they cannot fully account for differential sensitivity of hemp dogbane to these two herbicides. Differences in activity at the target site may be responsible for differential activity of these herbicides on hemp dogbane.

The response of ‘Era’ (tolerant) and ‘Coteau’ (susceptible) hard red spring wheat (Triticum aestivum L.) to CGA-82725 2-propynyl ester of {2-[4- [(3,5-dichloro-2-pyridinyl)oxy] phenoxy] propanoic acid} was determined in field and greenhouse evaluations. Era wheat was most susceptible to CGA-82725 applied at early jointing through the boot stage. Coteau wheat was most susceptible at die two-leaf stage and between early jointing through spike emergence. Coteau was injured more than Era wheat as the CGA-82725 rate was increased from 0.14 to 0.28 kg ai/ha. Wheat grain yield reductions were greatest when CGA-82725 was applied at the early jointing through boot stage for both cultivars and averaged 73% of the control. Absorption and translocation of 14C-CGA-82725 were similar and increased over time regardless of cultivar. Most of the absorbed 14C remained in the treated leaf in both cultivars.