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This article explores the relationship between solar UV radiation, climate change, and plastic pollution. It highlights the role of UV-driven weathering in the degradation of plastics and the formation of harmful micro- and nanoplastic particles. The article emphasizes the need for global assessments of plastic dispersal, persistence, and weathering to consider these linkages. It also discusses the impact of the Montreal Protocol on plastic degradation and the potential effects of UV radiation and climate change on plastic pollution in the future. The article concludes by calling for further research and the development of new plastics with durability matching the functional life of products. [Extracted from the article]

Litter decomposition plays a central role in carbon cycling in terrestrial ecosystems worldwide. In drylands, which cover 40% of the Earth's land surface, photodegradation and biotic decomposition driven by non‐rainfall moisture are important mechanisms of litter decay, though studies have only recently begun examining interactions between these two processes. We describe a novel priming mechanism in which photodegradation and biotic decay of the cuticle of plant litter increase litter absorption of non‐rainfall moisture (fog, dew and water vapor), supporting greater microbial decomposition.We used several field experiments in a coastal fog desert and a series of in situ observations to demonstrate a relationship between solar radiation, cuticle integrity, water absorption rates and mass loss.Experimentally attenuating solar radiation for 36 months slowed mass loss, reduced cuticle degradation and decreased litter moisture uptake relative to litter under ambient sunlight controls. In a separate field experiment, removing the cuticle of recently senesced grass tillers increased mass loss fourfold over 6 months relative to controls. Tillers with degraded cuticles also absorbed 3.8 times more water following an overnight dew event than did those with intact cuticles. Finally, fungal growth was consistently greater on the sun‐facing side of in situ tillers than on the shaded side, coincident with greater cuticle degradation.We present a conceptual model where the cuticle of plant litter acts as a water‐resistant barrier that is first degraded by solar radiation and surficial microbes, increasing litter's ability to absorb enough water during non‐rainfall moisture events to support substantial biotic decomposition inside the tissue. Considering how photodegradation and non‐rainfall moisture are both substantial drivers of litter decomposition in drylands, understanding how they interact under realistic field conditions will help us better predict how these systems are responding to changing climate regimes. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The accumulation of soluble and cell‐wall bound UV‐absorbing compounds (i.e., flavonoids) in the epidermis and the mesophyll of leaves is a response of plants to UV exposure. These compounds are known to function in UV screening, but they are also of potential value for food quality. One way to non‐destructively monitor UV screening in leaves is by optical methods, from which UVA‐PAM and Dualex instruments stand out. The degree and rapidity to which plants can modulate UV screening in response to fluctuating solar UV conditions is poorly understood. In this study, okra plants were exposed to two solar radiation treatments (near‐ambient UV [+UV] and attenuated UV [−UV]) and the epidermal UV transmittance (TUV; UVA‐PAM) and flavonoid index (Dualex) were measured in the youngest and second youngest mature leaves over three consecutive days and within an individual day. The day‐to‐day (measured near solar noon) and diurnal (over the course of a day) measurements of leaf optical properties indicated that TUV decreased and flavonoid index increased in the adaxial epidermis ~50% until 15:00 CDT then returned close to morning values later in the day. Correlations between UV‐B radiation and TUV and flavonoid index revealed highest values 30 min to 1 h prior to the measurements. These findings indicate that plants can respond quickly to fluctuating solar UV conditions and underlines the importance of the harvest‐time point for health‐promoting compounds in fruit and vegetables. Our findings also indicate that the UVA‐PAM and the Dualex instruments are both suitable instruments to monitor rapid changes in UV screening in plants. [ABSTRACT FROM AUTHOR]

Keywords: climate change; ecosystems; human health; Montreal Protocol; stratospheric ozone; sustainability; ultraviolet radiation; UV-B EN climate change ecosystems human health Montreal Protocol stratospheric ozone sustainability ultraviolet radiation UV-B 5681 5683 3 10/19/21 20211115 NES 211115 The Montreal Protocol and its Amendments have been highly effective in protecting the stratospheric ozone layer, preventing global increases in solar ultraviolet-B radiation (UV-B; 280-315 nm) at Earth's surface, and reducing global warming. Climate change, ecosystems, human health, Montreal Protocol, stratospheric ozone, sustainability, ultraviolet radiation, UV-B. [Extracted from the article]

These field studies sought to understand the ecological role of UV radiation in influencing plants growing in naturally high UV, alpine environments. Initially, the research in his lab examined the detrimental effects of increased UV-B radiation exposure on photosynthesis and growth (e.g., Dickson & Caldwell, 1978; Sisson & Caldwell, 1976). Soon after his dissertation research was published, Martyn compiled a number of plant UV responses to produce a "generalized" plant action spectrum (Caldwell, 1971) that, for many years, would serve as the standard biological UV spectral weighting function (BSWF) used in plant UV research. [Extracted from the article]

The accumulation of ultraviolet (UV)-absorbing compounds (flavonoids and related phenylpropanoids) and the resultant decrease in epidermal UV transmittance (TUV) are primary protective mechanisms employed by plants against potentially damaging solar UV radiation and are critical components of the overall acclimation response of plants to changing solar UV environments. Whether plants can adjust this UV sunscreen protection in response to rapid changes inUV, as occurs on a diurnal basis, is largely unexplored. Here, we use a combination of approaches to demonstrate that plants can modulate their UV-screening properties within minutes to hours, and these changes are driven, in part, by UVradiation. For the cultivated species Abelmoschus esculentus, large (30-50%) and reversible changes in TUV occurred on a diurnal basis, and these adjustments were associated with changes in the concentrations of whole-leaf UV-absorbing compounds and several quercetin glycosides. Similar results were found for two other species (Vicia faba and Solanum lycopersicum), but no such changes were detected in Zea mays. These findings reveal a much more dynamic UV-protection mechanism than previously recognized, raise important questions concerning the costs and benefits of UV-protection strategies in plants and have practical implications for employing UV to enhance crop vigor and quality in controlled environments. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the sources of contamination of cattle with phenylbutazone (PBZ). It mentions that PBZ, also known as bute, is a nonsteroidal anti-inflammatory drug (NSAID) for the treatment of musculoskeletal disorders in horses. It indicates that food-producing animals should be kept away from any vessels used to administer the bute to horses.

The controlled growth of self-assembled second-phase nanostructures has been shown to be an essential tool for enhancing properties of several composite oxide thin film systems. Here, the role of Y2O3 nanoparticles on the growth of BaZrO3 (BZO) nanorods is investigated in order to understand the mechanisms governing their self-assembly in YBa2Cu3O7- x (YBCO) thin films and to more fully control the resulting defect landscape. By examining the microstructure and current-carrying capacity of BZO-doped YBCO films, it is shown that the nanorod growth dynamics are significantly enhanced when compared to films double-doped with BZO and Y2O3 nanoparticles. The average nanorod length and associated critical current densities are found to increase at a significantly higher rate in the absence of Y2O3 nanoparticles when the growth temperature is increased. Using microstructural data from transmission electron microscopy studies and the response in critical current density, the interactive effects of multiple dopants that must be considered to fully control the defect landscape in oxide thin films are shown. [ABSTRACT FROM AUTHOR]

It is well known that where an auditor's relative bargaining power is high, this may help its independence and prevent a Type II error (no qualification but corporate failure). It is less well known that this may also lead to a lack of independence in the form of over-conservatism and an unjustified inclination by an auditor to qualify to protect its reputation leading to a Type I error (a qualification but no corporate failure). We therefore hypothesize that there is a positive relationship between the auditor's relative bargaining power and Type I errors ('H1') and a negative relationship between it and Type II errors ('H2'). The empirical study supports H1 but rejects H2. Taken together, these results suggest that Spanish auditors have a high propensity to qualify to protect their reputation, undeterred by pressure from client companies, in order to protect their reputation - 'over-conservatism' as we have called it. [ABSTRACT FROM AUTHOR]

Epidermal UV transmittance (TUV) and UV‐absorbing compounds were measured in sun and shade leaves of Populus tremuloides and Vicia faba exposed to contrasting light environments under field conditions to evaluate UV acclimation potentials and regulatory roles of photosynthetically active radiation (PAR) and UV in UV‐shielding. Within a natural canopy of P. tremuloides, TUV ranged from 4 to 98% and showed a strong nonlinear relationship with mid‐day horizontal fluxes of PAR [photon flux density (PFD) = 6–1830 µmol m−2 s−1]; similar patterns were found for V. faba leaves that developed under a comparable PFD range. A series of field transfer experiments using neutral‐density shade cloth and UV blocking/transmitting films indicated that PAR influenced TUV during leaf development to a greater degree than UV, and shade leaves of both species increased their UV‐shielding when exposed to full sun; however, this required the presence of UV, with both UV‐A and UV‐B required for full acclimation. TUV of sun leaves of both species was largely unresponsive to shade either with or without UV. In most, but not all cases, changes in TUV were associated with alterations in the concentration of whole‐leaf UV‐absorbing compounds. These results suggest that, (1) moderate‐to‐high levels of PAR alone during leaf development can induce substantial UV‐protection in field‐grown plants, (2) mature shade leaves have the potential to adjust their UV‐shielding which may reduce the detrimental effects of UV that could occur following sudden exposures to high light and (3) under field conditions, PAR and UV play different roles in regulating UV‐shielding during and after leaf development. [ABSTRACT FROM AUTHOR]

A new data collection strategy for performing synchrotron energy-dispersive X-ray diffraction computed tomography has been devised. This method is analogous to angle-dispersive X-ray diffraction whose diffraction signal originates from a line formed by intersection of the incident X-ray beam and the sample. Energy resolution is preserved by using a collimator which defines a small sampling voxel. This voxel is translated in a series of parallel straight lines covering the whole sample and the operation is repeated at different rotation angles, thus generating one diffraction pattern per translation and rotation step. The method has been tested by imaging a specially designed phantom object, devised to be a demanding validator for X-ray diffraction imaging. The relative strengths and weaknesses of the method have been analysed with respect to the classic angle-dispersive technique. The reconstruction accuracy of the method is good, although an absorption correction is required for lower energy diffraction because of the large path lengths involved. The spatial resolution is only limited to the width of the scanning beam owing to the novel collection strategy. The current temporal resolution is poor, with a scan taking several hours. The method is best suited to studying large objects ( e.g. for engineering and materials science applications) because it does not suffer from diffraction peak broadening effects irrespective of the sample size, in contrast to the angle-dispersive case. [ABSTRACT FROM AUTHOR]

Brief (1–100 min) irradiations with three different ultraviolet-B (UV-B) and ultraviolet-C (UV-C) wave bands induced increases the UV-absorbing pigments extracted from cucumber ( Cucumis sativus L.) and Arabidopsis. Spectra of methanol/1% HCl extracts from cucumber hypocotyl segments spanning 250–400 nm showed a single defined peak at 317 nm. When seedlings were irradiated with 5 kJ m−2 UV-B radiation containing proportionally greater short wavelength UV-B (37% of UV-B between 280 and 300 nm; full-spectrum UV-B, FS-UVB), tissue extracts taken 24 h after irradiation showed an overall increase in absorption (91% increase at 317 nm) with a second defined peak at 263 nm. Irradiation with 1.1 kJ m−2 UV-C (254 nm) caused similar changes. In contrast, seedlings irradiated with 5 kJ m−2 UV-B including only wavelengths longer than 290 nm (8% of UV-B between 290 and 300 nm; long-wavelength UV-B, LW-UVB) resulted only in a general increase in absorption (80% at 317 nm). The increases in absorption were detectable as early as 3 h after irradiation with FS-UVB and UV-C, while the response to LW-UVB was first detectable at 6 h after irradiation. In extracts from whole Arabidopsis seedlings, 5 kJ m−2 LW-UVB caused only a 20% increase in total absorption. Irradiation with 5 kJ m−2 FS-UVB caused the appearance of a new peak at 270 nm and a concomitant increase in absorption of 72%. The induction of this new peak was observed in seedlings carrying the fah1 mutation which disrupts the pathway for sinapate synthesis. The results are in agreement with previously published data on stem elongation indicating the existence of two response pathways within the UV-B, one operating at longer wavelengths (>300 nm) and another specifically activated by short wavelength UV-B (<300 nm and also by UV-C). [ABSTRACT FROM AUTHOR]

Studies were conducted on three herbaceous plant species growing in naturally high solar UV environments in the subalpine of Mauna Kea, Hawaii, USA, to determine if diurnal changes in epidermal UV transmittance (TUV) occur in these species, and to test whether manipulation of the solar radiation regime could alter these diurnal patterns. Additional field studies were conducted at Logan, Utah, USA, to determine if solar UV was causing diurnal TUV changes and to evaluate the relationship between diurnal changes in TUV and UV-absorbing pigments. Under clear skies, TUV, as measured with a UV-A-pulse amplitude modulation fluorometer for leaves of Verbascum thapsus and Oenothera stricta growing in native soils and Vicia faba growing in pots, was highest at predawn and sunset and lowest at midday. These patterns in TUV closely tracked diurnal changes in solar radiation and were the result of correlated changes in fluorescence induced by UV-A and blue radiation but not photochemical efficiency (Fv/Fm) or initial fluorescence yield (Fo). The magnitude of the midday reduction in TUV was greater for young leaves than for older leaves of Verbascum. Imposition of artificial shade eliminated the diurnal changes in TUV in Verbascum, but reduction in solar UV had no effect on diurnal TUV changes in Vicia. In Vicia, the diurnal changes in TUV occurred without detectable changes in the concentration of whole-leaf UV-absorbing compounds. Results suggest that plants actively control diurnal changes in UV shielding, and these changes occur in response to signals other than solar UV; however, the underlying mechanisms responsible for rapid changes in TUV remain unclear. [ABSTRACT FROM AUTHOR]

With progress of the YBCO-coated conductor to longer lengths, application of the conductor is nearing. An overview of a couple of current U.S. Air Force application programs is presented. A discussion is then made of where research and development of the YBCO-coated conductor should progress and examples in the U.S. Air Force program. These areas include magnetic flux pinning in YBCO thin films, reduction of the ac losses experienced in the YBCO conductor, and stability and quench issues when implementing the YBCO-coated conductor. [ABSTRACT FROM AUTHOR]

This paper examines the principal determinants of an organization's susceptibility to theft and fraud in the context of a rational economic framework in which the level of protection is determined by the minimization of cost. The empirical study shows that, adjusting for differences in organizational type and industrial sector, both organizational susceptibility and the size of a typical theft or fraud increase with organizational size. Access to resources and the manner in which the theft or fraud is perpetrated are also important determinants of the money lost. However, they are unaffected by management controls or the nature of their violation. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Elevated concentrations of sulfide in groundwater (∼63 mg S2-/L in water and 500 mg dissolved H2S/L dissipating from the wellhead) at a field site near South Lovedale (OK, USA) were inhibiting the activity of sulfate-reducing bacteria (SRB) that are known to degrade contaminants, including benzene, toluene, ethylbenzene, and xylenes. Elevated concentrations of these contaminants, except for toluene, also were present in this groundwater. Microcosms were established in the laboratory using groundwater and sediment collected from the field site and amended with various nutrient, substrate, and inhibitor treatments. All microcosms initially were amended with FeCl2 to induce FeS precipitation and, thereby, to reduce aqueous sulfide concentrations. Complete removal of benzene, ethylbenzene, and m+p-xylenes (BEX; o-xylene not detected) was observed within 39 d in treatments with various combinations of nutrient and substrate amendments, including treatments with no amendments (other than FeCl2). This indicates that the elevated concentration of sulfide is the only limiting factor to BEX biodegradation at this site under anaerobic conditions and that treating the groundwater with FeCl2 may be a simple remedy to both facilitate and enhance BEX degradation by the indigenous SRB population. [ABSTRACT FROM AUTHOR]

We examined the influence of short-term exposure of different UV wavebands on the fine-scale kinetics of hypocotyl growth of dim red light-grown cucumbers (Cucumis sativus L.) and other selected dicotyledonous seedlings to evaluate: (1) whether responses induced by UV-B radiation (280–320 nm) are qualitatively different from those induced by UV-A (320–400 nm) radiation, and (2) whether different wavebands within the UV-B elicit different responses. Responses to brief (30 min) irradiations with 3 different UV wavebands all included transient inhibition of elongation during irradiation followed by wavelength specific responses. Irradiations with proportionally greater short wavelength UV-B (37% of UV-B between 280 and 300 nm) induced inhibition of hypocotyl elongation within 20 min of onset of irradiation, while UV-B including only wavelengths longer than 290 nm (and only 8% of UV-B between 290 and 300 nm) induced inhibition of hypocotyl elongation with a lag of 1–2 h. The response to short wavelength UV-B was persistent for at least 24 h, while the response to long wavelength UV-B lasted only 2–3 h. The UV-A treatment induced reductions in elongation rates of approximately 6–9 h following exposure followed by a continued decline in rates for the following 15–18 h. Short wavelength UV-B also induced positive phototropic curvature in both cucumber and Arabidopsis seedlings, and this response was present in nph-1 mutant Arabidopsis seedlings defective in normal blue light phototropism. Reciprocity was not found for the response to short wavelength UV-B. The short wavelength and long wavelength UV-B responses differed in dose–response relationships and both short wavelength responses (phototropic curvature and elongation inhibition) increased sharply at wavelengths below 300 nm. These results indicate that different photosensory processes are involved in mediating growth and morphological responses to short wavelength UV-B (280–300 nm), long wavelength UV-B (essentially 300–320 nm) and UV-A. The existence of two separate types of hypocotyl inhibition responses to UV-B, with one that depends on the intensity of the light source, provides alternate interpretations to findings in other studies of UV-B induced photomorphogenesis and may explain inconsistencies between action spectra for inhibition of stem growth. [ABSTRACT FROM AUTHOR]

Examines changes in heat treated high-alumina castables. Application of Young's modulus measurements and synchrotron radiation-energy dispersive diffraction; Analysis of the hydrate conversion process; Facilitation of sample environmental cells by fixed beam geometry.

Ratios of chlorophyll fluorescence induced by ultraviolet (UV) and bluegreen (BG) radiation [F(UV)/F(BG)] were determined with a Xe-PAM fluorometer to test the utility of this technique as a means of non-intrusively assessing changes in the pigmentation and optical properties of leaves exposed to varying UV exposures under laboratory and field conditions. For plants of Vicia faba and Brassica campestris, grown under controlled-environmental conditions, F(UV-B)/F(BG) was negatively correlated with whole-leaf UV-B-absorbing pigment concentrations. Fluorescence ratios of V. faba were similar to, and positively correlated with (r2=0.77 [UV-B]; 0.85 [UV-A]), direct measurements of epidermal transmittance made with an integrating sphere. Leaves of 2 of 4 cultivars of field-grown Glycine max exposed to near-ambient solar UV-B at a mid-latitude site (Buenos Aires, Argentina, 34° S) showed significantly lower abaxial F(UV-B)/F(BG) values (i.e., lower UV-B epidermal transmittance) than those exposed to attenuated UV-B, but solar UV-B reduction had a minimal effect on F(UV-B)/F(BG) in plants growing at a high-latitude site (Tierra del Fuego, Argentina, 55° S). Similarly, the exotic Taraxacum officinale did not show significant changes in F(UV-B)/F(BG) when exposed to very high supplemental UV-B (biologically effective UV-B=14–15 kJ m-2 day-1) in the field in Tierra del Fuego, whereas a native species, Gunnera magellanica, showed significant increases in F(UV-B)/F(BG) relative to those receiving ambient UV-B. These anomalous fluorescence changes were associated with increases in BG-absorbing pigments (anthocyanins), but not UV-B-absorbing pigments. These results indicate that non-invasive estimates of epidermal transmittance of UV radiation using chlorophyll fluorescence can detect changes in pigmentation and leaf optical properties induced by UV-B radiation under both field and laboratory conditions. However, this technique may be of limited utility in cold environments where UV and low temperatures can stimulate the production of BG-absorbing pigments that interfere with these indirect measurements of UV-transmittance. [ABSTRACT FROM AUTHOR]

Broad-band UV-B radiation inhibited hypocotyl elongation in etiolated tomato (Lycopersicon esculentum Mill. cv. Alisa Craig) seedlings. This inhibition could be elicited by < 3 µmol m-2 s-1 of UV-B radiation provided against a background of white light (> 620 µmol m-2 s-1 between 320 and 800 nm), and was similar in wild-type and phytochrome-I-deficient aurea mutant seedlings. These observations suggest that the effect of UV-B radiation is not mediated by phytochrome. An activity spectrum obtained by delivering 1 µmol m-2 s-1 of monochromatic UV radiation against a white light background (63 µmol m-2 s-1) showed maximum effectiveness around 300 nm, which suggests that DNA or aromatic residues in proteins are not the chromophores mediating UV-B induced inhibition of elongation. Chemicals that affect the normal (photo)chemistry of flavins and possibly pterins (KI, NaN3 and phenylacetic acid) largely abolished the inhibitory effect of broad-band UV-B radiation when applied to the root zone before irradiation. KI was effective at concentrations < 10-4 M, which have been shown in vitro to be effective in quenching the triplet excited states of flavins but not fluorescence from pterine or singlet states of flavins. Elimination of blue light or reduction of UV-A, two sources of flavin excitation, promoted hypocotyl elongation, but did not affect the inhibition of elongation exerted by UV-B. KI applied after UV-B irradiation had no effect on the inhibition response. Taken together these findings suggest that the chromophore of the photoreceptor system involved in UV-B perception by tomato seedlings during de-etiolation may be a flavin. [ABSTRACT FROM AUTHOR]

UV-B radiation inhibits hypocotyl elongation in etiolated tomato (Lycopersicon esculentum Mill. cv. Alisa Craig) seedlings acting through a photoreceptor system with peak apparent effectiveness around 300 nm. In order to further characterize the response and gain insight into its potential ecological significance, the time-course of inhibition was measured and compared with the time-course of flavonoid accumulation in the same seedlings. When a background of strong (> 620 µmol m-2 s-1) white light (WL) was supplemented with low irradiance UV-B (∼ 3 µmol m-2 s-1), substantial (∼ 50%) inhibition of elongation occurred within 3 h of the light treatment. The magnitude of UV-B-induced elongation inhibition was similar in wild type (WT) and au-mutant seedlings, in spite of the large differences between genotypes in rate and temporal pattern of elongation. In comparison to the effect of UV-B on elongation, induction of flavonoid accumulation in WT and au seedlings undergoing de-etiolation was a much slower response. Several UV-absorbing compounds appeared to be specifically induced by light, and some of them accumulated faster under the WL + UV-B treatment than under WL alone. However, there was little or no detectable effect of WL on flavonoid levels until up to 3 h of treatment, and the specific UV-B effect was measurable only after 6 h of continuous treatment. Indeed, UV-B-screening properties of crude alcoholic extracts were not different between WL and WL + UV-B treatments until after 9 or 24 h. When the light treatments were applied to seedlings that were just breaking through the soil surface, UV-B was found to consistently retard seedling emergence. These results suggest that the rapid inhibition of elongation in de-etiolating seedlings is an evolved response to UV-B, which may serve to minimize seedling exposure to sunlight until protective pigmentation responses (triggered by WL and UV-B) have taken place in the seedlings' epidermis. [ABSTRACT FROM AUTHOR]

Hypocotyl elongation responses to ultraviolet-B (UV-B) radiation were investigated in glasshouse studies of de-etiolated seedlings of a long-hypocotyl mutant (lh) of cucumber (Cucumis sativus L.) deficient in stable phytochrome, its near isogenic wild type (WT), and a commercial cucumber hybrid (cv. Burpless). A single 6- or 8-h exposure to UV-B applied against a background of white light inhibited hypocotyl elongation rate by ca 50% in and WT seedlings. This effect was not accompanied by a reduction in cotyledon area expansion or dry matter accumulation. Plants recovered rapidly from inhibition and it was possible to stimulate hypocotyl elongation in plants exposed to UV-B by application of gibberellic acid. In all genotypes inhibition of elongation was mainly a consequence of UV-B perceived by the cotyledons; covering the apex and hypocotyl with a filter that excluded UV-B failed to prevent inhibition. These results indicate that reduced elongation does not result from assimilate limitation or direct damage to the apical meristem or elongating cells, and strongly suggest that it is a true response to UV-B. The fact that UV-B influences used were very low in relation to total visible light, and the similarity in the responses of lh and wild-type plants, are consistent with the hypothesis that UV-B acts through a specific photoreceptor. It is argued that, given the weak correlation between UV-B and visible-light levels in most natural conditions, the UV-B receptor may play an important sensory function providing information to the plant that cannot be derived from light signals perceived by phytochrome or blue/UV-A sensors. [ABSTRACT FROM AUTHOR]

Mixtures and monocultures of wheat (Triticum aestivum) and wild oat (Avena fatua), a common weedy competitor of wheat, were exposed to enhanced solar UV-B radiation simulating a 20% reduction in stratospheric ozone to assess the timing and seasonal development of the UV-B effects on light competition in these species. Results from two years of field study revealed that UV-B enhancement had no detectable effect on the magnitude or timing of seedling emergence in either species. End-of-season measurements showed significant UV-B inhibition of leaf insertion height in wild oat in mixture and monoculture in the second year (irrigated year) but not in the first year (drought year). Leaf insertion height of wheat was not affected by UV-B in either year. The UV-B treatment had no detectable effect on monoculture or total (combined species) mixture LAI but did significantly increase (5-7%) the fractional contribution of wheat to the mixture LAI after four weeks of growth in both years. In addition, the UV-B treatment had subtle effects on LAI height profiles with early season mixtures showing significant reductions in wild oat LAI in lower canopy layers in both years while mid-season Year 2 mixtures showed significant reductions in wild oat LAI in upper canopy layers. The changes in canopy structure were found to significantly increase (6-7%) the proportional simulated clear sky canopy photosynthesis and light interception of wheat in mixture. These findings, and others, indicate that the effects of UV-B enhancement on competition are realized very early in canopy development and provide additional support for the hypothesis that UV-B enhancement may shift the balance of competition between these species indirectly by altering competitive interactions for light. [ABSTRACT FROM AUTHOR]

Examines the bidding associated with mergers, highlighting evidence from the United Kingdom. Reference to studies conducted by R. Roll in 1986; In-depth look at the merger bidding process; Detailed information on the game-theoretic approach; Hypothesis that the generosity of the merger terms increases the probability of acceptance; Problems associated with the `analogy' of an auction and a merger bid.

The article reports that the 1980s have been referred to as the "decade of the deal," with merger, takeover and buyout related activity in the last two years of the period exceeding, by a considerable margin, both previous levels and those experienced in the first half of the 1990s. The strategies and motivations for corporate restructuring became more varied and complex but were frequently seen as undoing the mistakes of the past and enhancing shareholder value. In addition to the impact on corporate control resulting from these changes in the traditional takeover market, the 1980s also saw the emergence of the privatization of corporate ownership. One strand of this development was the taking private of stock market quoted companies in the form of leveraged and management buy-outs. The increasing diversity of corporate control, and the emergence of more varied types of ownership structure, suggest that this is an appropriate time to reflect on recent developments and their implications for understanding the underlying economics of the processes involved.

The purpose of this study is, therefore, to build on the work of Kida and examine the going concern decision and the judgements leading up to that decision based on both quantitative and qualitative information in order to discover why auditors are apparently poor at making such a decision. Are they reluctant to qualify, because of the consequences to them as Kida suggests, or are they not competent to make such a judgement, as may be inferred from the statistical studies?
The empirical study largely confirmed the competence hypothesis at the preliminary information level. Subjects agreed that the company had going concern problems and they largely agreed about what factors they take into account. There was also a degree of agreement concerning mitigating evidence, but this was not quite so unanimous.
The case study that subjects were given was designed so that the preliminary financial data would indicate going concern problems. However, after examining other qualitative, 'inside', information that the auditor would receive during the course of his audit (mitigating evidence), the question of whether or not to qualify became much more difficult. It was in this light that subjects' responses were assessed. The important finding was that, whilst the predictive behavioural models were quite good at forecasting subjects' decisions, they were much better at predicting qualifications than non-qualifications. This indicates that there were other considerations present when deciding not to qualify for a company that has going concern problems. Specifically, it points to the lack of auditor independence and the possibility of bias against a qualification. [ABSTRACT FROM AUTHOR]

A bargaining model of a merger involving share exchange is examined in which directors of the bidder may dissimulate. It is shown that there is an incentive for them to over or understate synergy, depending on their perceptions of relative bargaining power. The ambiguity of the offer has implications for merger policy and the regulation of information. [ABSTRACT FROM AUTHOR]

The use of MDA and related techniques has been examined here mainly from the perspective of predictive ability. It has been argued that the stability of the model, in various respects, is the single most important consideration, and that various improvements to the way in which it is usually devised have been discussed. The use of the industry-relative ratio was advocated and was illustrated by means of some UK data giving a reasonably high prediction success rate. Unfortunately, because of the subsequent market crash this could not be reasonably tested over a later period. [ABSTRACT FROM AUTHOR]

This article reviews a study on the uses of financial ratios. Financial ratios are used to assess the ability of a firm to pay its debts, determine managerial effectiveness, and evaluate a firm's performance. The article identified two types of positive uses of financial ratios: (1) by accountants and analysts to forecast future financial variables and (2) by researchers in statistical models for mainly predictive purposes. The article presents considerable advances in using the financial ratios in their statistical nature.

Comments on an article concerning statistical validity of the ratio method versus regression analysis for financial analysis. Sources of heteroscedasticity; Provision of an evidence of the existence of heteroscedasticity in cross-sectional data; Empirical results and inferences.

This article presents a study on the stock market efficiency and low volume of trading at the Kuala Lumpur Stock Market. Thirty companies and six sector indices for the six years ended 30th June 1980 were examined. Only companies that were traded both during the last two days of the first month and during the last two days of the last month of the data period were selected. The serial correlation coefficient measures the relationship between the value of a random variable at time and its value in the previous period. After two efficient tests, a third and more complicated test is also conducted. The application of spectral analysis not only serves to confirm or reject the results of the earlier two tests; it also shows any isolated deviations from the random walk model in both the high and low frequency regions of the spectrum.

The article focuses on building society mergers in Great Britain. The Chief Registrar of Friendly Societies has actively encouraged mergers between the smaller societies throughout the 1970s. Many building society chiefs have embraced his views and have used them as reasons for their societies actively searching out takeover victims. In fact commentators frequently talk nowadays of a dozen or so building societies as the eventual state. Such views have been rarely challenged and the merger movement has been largely ignored as a public issue. However the empirical evidence concerning industrial mergers more generally and related theories of merger activity, suggest that there is often no economic case for such merger mania and that such activity may be explained in terms of simple managerial motives of self-interest. The empirical evidence shows that while acquiring firms on average are more profitable, and acquired firms less so, it is not correct to infer that the combined unit will retain above average profitability. Subsequent to the merger, acquiring firms in Great Britain have tended to reductions in profitability.

It has often been argued that the monopolistic position of building societies and the lack of constraints on policies of their managers has brought inefficiencies and managerial utility maximising results. This may be seen in society growth policies and their expense preference behaviour. When there is increased competition affecting margins some building societies may earn insufficient profits so as to threaten their financial stability. The present study uses multiple discriminant analysis to study the period 1978-1980 and verifies the hypothesis that both growth and expense preferences caused profit insufficiency which could lead to financial distress. [ABSTRACT FROM AUTHOR]

Discusses some of the issues concerning the evolving structure of the building society industry in Great Britain during the 1970s. Discussion of the economics and the constitution of the movement; Development of a behavioral hypotheses; Variations in building societies' operations.

Empirical studies have shown distributions of financial ratios are skewed. An explanation for this is given and it is argued that in such circumstances comparison of a financial ratio with some norm (e.g. industry average) is likely to misinform. It is also shown that where financial ratios are used as inputs to statistical models normality is irrelevant but a method of transformation into a normal distribution is provided whereby original interrelationships are preserved. Finally, because of the inadequacies of financial ratios, it is shown how regression analysis may be used in financial statement analysis. [ABSTRACT FROM AUTHOR]

This reply extends the contention that financial ratios cannot be used comparatively with any safety. It is shown that the obstacles posed by Horrigan for residual analysis may easily be overcome. [ABSTRACT FROM AUTHOR]