Exchange rate exposure : do size and foreign operations matter?

Purpose – The purpose of this paper is to examine the effect of firm size and foreign operations on the exchange rate exposure of UK non-financial companies from January 1981 to December 2001. Design/methodology/approach – The impact of the unexpected changes in exchange rates on firms’ stock returns is examined. In addition, the movements in bilateral, equally weighted (EQW) and trade-weighted and exchange rate indices are considered. The sample is classified according to firm size and the extent of firms’ foreign operations. In addition, structural changes on the relationship between exchange rate changes and individual firms’ stock returns are examined over three sub-periods: before joining the exchange rate mechanism (pre-ERM), during joining the ERM (in-ERM), and after departure from the ERM (post-ERM). Findings – The findings indicate that a higher percentage of UK firms are exposed to contemporaneous exchange rate changes than those reported in previous studies. UK firms’ stock returns are more affected by changes in the EQW, and US$ European currency unit exchange rate, and respond less significantly to the basket of 20 countries’ currencies relative to the UK pound exchange rate. It is found that exchange rate exposure has a more significant impact on stock returns of the large firms compared with the small and medium-sized companies. The evidence is consistent across all specifications using different exchange rate. The results provide evidence that the proportion of significant foreign exchange rate exposure is higher for firms which generate a higher percentage of revenues from abroad. The sensitivities of firms’ stock returns to exchange rate fluctuations are most evident in the pre-ERM and post-ERM periods. Practical implications – This study provides important implications for public policymakers, financial managers and investors on how common stock returns of various sectors react to exchange rate fluctuations. Originality/value – The empirical evidence supports the view that UK firms’ stock returns are affected by foreign exchange rate exposure.

Development of a post-mitotic, neuronal-astrocytic cell system, for the prediction of acute neurotoxicity in humans

The human NT2.D1 cell line was differentiated to form both a 1:2 co-culture of post-mitotic NT2 neuronal and NT2 astrocytic (NT2.N/A) cells and a pure NT2.N culture. The respective sensitivities to several test chemicals of the NT2.N/A, the NT2.N, and the NT2.D1 cells were evaluated and compared with the CCF-STTG1 astrocytoma cell line, using a combination of basal cytotoxicity and biochemical endpoints. Using the MTT assay, the basal cytotoxicity data estimated the comparative toxicities of the test chemicals (chronic neurotoxin 2,5-hexanedione, cytotoxins 2,3- and 3,4-hexanedione and acute neurotoxins tributyltin- and trimethyltin- chloride) and also provided the non-cytotoxic concentration-range for each compound. Biochemical endpoints examined over the non-cytotoxic range included assays for ATP levels, oxidative status (H2O2 and GSH levels) and caspase-3 levels as an indicator of apoptosis. although the endpoints did not demonstrate the known neurotoxicants to be consistently more toxic to the cell systems with the greatest number of neuronal properties, the NT2 astrocytes appeared to contribute positively to NT2 neuronal health following exposure to all the test chemicals. The NT2.N/A co-culture generally maintained superior ATP and GSH levels and reduced H2O2 levels in comparison with the NT2.N mono-culture. In addition, the pure NT2.N culture showed a significantly lower level of caspase-3 activation compared with the co-culture, suggesting NT2 astrocytes may be important in modulating the mode of cell death following toxic insult. Overall, these studies provide evidence that an in vitro integrated population of post-mitotic human neurons and astrocytes may offer significant relevance to the human in vivo heterogeneous nervous system, when initially screening compounds for acute neurotoxic potential.

Exchange rate exposure:do size and foreign operations matter?

Purpose – The purpose of this paper is to examine the effect of firm size and foreign operations on the exchange rate exposure of UK non-financial companies from January 1981 to December 2001. Design/methodology/approach – The impact of the unexpected changes in exchange rates on firms’ stock returns is examined. In addition, the movements in bilateral, equally weighted (EQW) and trade-weighted and exchange rate indices are considered. The sample is classified according to firm size and the extent of firms’ foreign operations. In addition, structural changes on the relationship between exchange rate changes and individual firms’ stock returns are examined over three sub-periods: before joining the exchange rate mechanism (pre-ERM), during joining the ERM (in-ERM), and after departure from the ERM (post-ERM). Findings – The findings indicate that a higher percentage of UK firms are exposed to contemporaneous exchange rate changes than those reported in previous studies. UK firms’ stock returns are more affected by changes in the EQW, and US$ European currency unit exchange rate, and respond less significantly to the basket of 20 countries’ currencies relative to the UK pound exchange rate. It is found that exchange rate exposure has a more significant impact on stock returns of the large firms compared with the small and medium-sized companies. The evidence is consistent across all specifications using different exchange rate. The results provide evidence that the proportion of significant foreign exchange rate exposure is higher for firms which generate a higher percentage of revenues from abroad. The sensitivities of firms’ stock returns to exchange rate fluctuations are most evident in the pre-ERM and post-ERM periods. Practical implications – This study provides important implications for public policymakers, financial managers and investors on how common stock returns of various sectors react to exchange rate fluctuations. Originality/value – The empirical evidence supports the view that UK firms’ stock returns are affected by foreign exchange rate exposure.

Development of a neurotoxicity test-system, using human post-mitotic, astrocytic and neuronal cell lines in co-culture

Astrocytes are essential for neuronal function and survival, so both cell types were included in a human neurotoxicity test-system to assess the protective effects of astrocytes on neurons, compared with a culture of neurons alone. The human NT2.D1 cell line was differentiated to form either a co-culture of post-mitotic NT2.N neuronal (TUJ1, NF68 and NSE positive) and NT2.A astrocytic (GFAP positive) cells (∼2:1 NT2.A:NT2.N), or an NT2.N mono-culture. Cultures were exposed to human toxins, for 4 h at sub-cytotoxic concentrations, in order to compare levels of compromised cell function and thus evidence of an astrocytic protective effect. Functional endpoints examined included assays for cellular energy (ATP) and glutathione (GSH) levels, generation of hydrogen peroxide (H2O2) and caspase-3 activation. Generally, the NT2.N/A co-culture was more resistant to toxicity, maintaining superior ATP and GSH levels and sustaining smaller significant increases in H2O2 levels compared with neurons alone. However, the pure neuronal culture showed a significantly lower level of caspase activation. These data suggest that besides their support for neurons through maintenance of ATP and GSH and control of H2O2 levels, following exposure to some substances, astrocytes may promote an apoptotic mode of cell death. Thus, it appears the use of astrocytes in an in vitro predictive neurotoxicity test-system may be more relevant to human CNS structure and function than neuronal cells alone. © 2007 Elsevier Ltd. All rights reserved.

Flanerie: A post -reflexive mode of urban research inquiry

Urban ethnographic studies in social science usually proceed from within a pre-figured research framework that guides field activity and filters what is considered see-worthy and study-worthy to those phenomena which are in some way necessary for the fulfillment of specific research agendas. Reliance on formalized ethnographic research methods to explore the city, and the reflex to intellectualize that which is observed by using them, frequently leads to the neglect of much of what comprises the ethnographic richness of city-life through an overly-contemplative intellectuocentrism. ^ Flânerie, an avocational, proto-sociological ethnographic mode of urban exploration and observation originating in early-nineteenth-century Paris, is representative of an alternate approach to exploration and study of the city—one less subject to a compressed horizon of ethnographic experience. It affords insight into a broad range of phenomena taking place in interstitial urban space and time which often escape the instrumentally overly-determined gaze of professionalist research inquiry. ^ The present work addressed the fact that the concept of flânerie , though occasionally invoked in discussions of methodology in urban sociology and cultural studies, had not been subjected to a systematic attempt to relate it to the research methods of these disciplines. Though as a typological figure the flâneur is thought to have disappeared long ago, practices represented by the concept continue to be engaged in by persons inside and outside of academia who approach city life and social science with a perspective somewhat transcending the reified dichotomies of private-professional and art-and-science. This study transferred aspects of the experience of the city embodied in the flâneur to the realm of ethnographic urban studies and the building of grounded social theory, finding flânerie to be crucial to the development of a refined knowledge of urban life, and an important means by which previously overlooked social phenomena and silenced avenues of research inquiry might be exposed. ^ The conclusions reached found a “flâneuristic” approach to the city as being beneficial to research practice and the vitalization of urban ethnographic inquiry, by affording opportunities for exposure to, and immersion within, an expanded range of quotidian social phenomena that have frequently escaped the academicist gaze. ^

Advancing atomic nanolithography: cold atomic Cs beam exposure of alkanethiol self-assembled monolayers

We report the results of a study into the quality of functionalized surfaces for nanolithographic imaging. Self-assembled monolayer (SAM) coverage, subsequent post-etch pattern definition and minimum feature size all depend on the quality of the Au substrate used in atomic nanolithographic experiments. We find sputtered Au substrates yield much smoother surfaces and a higher density of {111} oriented grains than evaporated Au surfaces. A detailed study of the self-assembly mechanism using molecular resolution AFM and STM has shown that the monolayer is composed of domains with sizes typically of 5-25 nm, and multiple molecular domains can exist within one Au grain. Exposure of the SAM to an optically-cooled atomic Cs beam traversing a two-dimensional array of submicron material masks ans also standing wave optical masks allowed determination of the minimum average Cs dose (2 Cs atoms per SAM molecule) and the realization of < 50 nm structures. The SAM monolayer contains many non-uniformities such as pin-holes, domain boundaries and monoatomic depressions which are present in the Au surface prior to SAM adsorption. These imperfections limit the use of alkanethiols as a resist in atomic nanolithography experiments. These studies have allowed us to realize an Atom Pencil suitable for deposition of precision quantities of material at the microand nanoscale to an active surface.

Developmental exposure to a complex PAH mixture causes persistent behavioral effects in naive Fundulus heteroclitus (killifish) but not in a population of PAH-adapted killifish.

Acute exposures to some individual polycyclic aromatic hydrocarbons (PAHs) and complex PAH mixtures are known to cause cardiac malformations and edema in the developing fish embryo. However, the heart is not the only organ impacted by developmental PAH exposure. The developing brain is also affected, resulting in lasting behavioral dysfunction. While acute exposures to some PAHs are teratogenically lethal in fish, little is known about the later life consequences of early life, lower dose subteratogenic PAH exposures. We sought to determine and characterize the long-term behavioral consequences of subteratogenic developmental PAH mixture exposure in both naive killifish and PAH-adapted killifish using sediment pore water derived from the Atlantic Wood Industries Superfund Site. Killifish offspring were embryonically treated with two low-level PAH mixture dilutions of Elizabeth River sediment extract (ERSE) (TPAH 5.04 μg/L and 50.4 μg/L) at 24h post fertilization. Following exposure, killifish were raised to larval, juvenile, and adult life stages and subjected to a series of behavioral tests including: a locomotor activity test (4 days post-hatch), a sensorimotor response tap/habituation test (3 months post hatch), and a novel tank diving and exploration test (3months post hatch). Killifish were also monitored for survival at 1, 2, and 5 months over 5-month rearing period. Developmental PAH exposure caused short-term as well as persistent behavioral impairments in naive killifish. In contrast, the PAH-adapted killifish did not show behavioral alterations following PAH exposure. PAH mixture exposure caused increased mortality in reference killifish over time; yet, the PAH-adapted killifish, while demonstrating long-term rearing mortality, had no significant changes in mortality associated with ERSE exposure. This study demonstrated that early embryonic exposure to PAH-contaminated sediment pore water caused long-term locomotor and behavioral alterations in killifish, and that locomotor alterations could be observed in early larval stages. Additionally, our study highlights the resistance to behavioral alterations caused by low-level PAH mixture exposure in the adapted killifish population. Furthermore, this is the first longitudinal behavioral study to use killifish, an environmentally important estuarine teleost fish, and this testing framework can be used for future contaminant assessment.

Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes) embryos.

This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001-10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6-7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity.

Motivation and Vocabulary Breadth in CLIL and EFL Contexts. Different age, Same Time of Exposure

Numerous studies have found a positive connection between learners’ motivation towards foreign language and foreign language achievement. The present study examines the role of motivation in receptive vocabulary breadth (size) of two groups of Spanish learners of different ages, but all with 734 hours of instruction in English as a Foreign Language (EFL): a CLIL (Content and Language Integrated Learning) group in primary education and a non-CLIL (or EFL) group in secondary education. Most students in both groups were found to be highly motivated. The primary CLIL group slightly overcame the secondary non-CLIL group with respect to the mean general motivation but this is a non-significant difference. The secondary group surpass significantly the primary group in receptive vocabulary size. No relationship between the receptive vocabulary knowledge and general motivation is found in the primary CLIL group. On the other hand, a positive significant connection, although a very small one, is identified for the secondary non-CLIL group. We will discuss on the type of test, the age of students and the type of instruction as variables that could be influencing the results.

Firefighters' exposure biomonitoring: Impact of firefighting activities on levels of urinary monohydroxyl metabolites

The concentrations of six urinary monohydroxyl metabolites (OH-PAHs) of polycyclic aromatic hydrocarbons, namely 1-hydroxynaphthalene, 1-hydroxyacenaphthene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 1-hydroxypyrene (1OHPy), and 3-hydroxybenzo[a]pyrene, were assessed in the post-shift urine of wildland firefighters involved in fire combat activities at six Portuguese fire corporations, and compared with those of non-exposed subjects. Overall, median levels of urinary individual and total OH-PAHs (ΣOH-PAHs) suggest an increased exposure to polycyclic aromatic hydrocarbons during firefighting activities with ΣOH-PAH levels in exposed firefighters 1.7-35 times higher than in non-exposed ones. Urinary 1-hydroxynaphthalene and/or 1-hydroxyacenapthene were the predominant compounds, representing 63-98% of ΣOH-PAHs, followed by 2-hydroxyfluorene (1-17%), 1-hydroxyphenanthrene (1-13%), and 1OHPy (0.3-10%). A similar profile was observed when gender discrimination was considered. Participation in fire combat activities promoted an increase of the distribution percentage of 1-hydroxynaphthalene and 1-hydroxyacenaphthene, while contributions of 1-hydroxyphenanthrene and 1OHPy decreased. The detected urinary 1OHPy concentrations (1.73×10(-2) to 0.152μmol/mol creatinine in exposed subjects versus 1.21×10(-2) to 5.44×10(-2)μmol/mol creatinine in non-exposed individuals) were lower than the benchmark level (0.5μmol/mol creatinine) proposed by the American Conference of Governmental Industrial Hygienists. This compound, considered the biomarker of exposure to PAHs, was the less abundant one from the six analyzed biomarkers. Thus the inclusion of other metabolites, in addition to 1OHPy, in future studies is suggested to better estimate firefighters' occupational exposure to PAHs. Moreover, strong to moderate Spearman correlations were observed between individual compounds and ΣOH-PAHs corroborating the prevalence of an emission source.

Polycyclic aromatic hydrocarbons at fire stations: firefighters’ exposure monitoring and biomonitoring, and assessment of the contribution to total internal dose

This work characterizes levels of eighteen polycyclic aromatic hydrocarbons (PAHs) in the breathing air zone of firefighters during their regular work shift at eight Portuguese fire stations, and the firefighters' total internal dose by six urinary monohydroxyl metabolites (OH-PAHs). Total PAHs (ΣPAHs) concentrations varied widely (46.4-428ng/m(3)), mainly due to site specificity (urban/rural) and characteristics (age and layout) of buildings. Airborne PAHs with 2-3 rings were the most abundant (63.9-95.7% ΣPAHs). Similarly, urinary 1-hydroxynaphthalene and 1-hydroxyacenaphthene were the predominant metabolites (66-96% ΣOH-PAHs). Naphthalene contributed the most to carcinogenic ΣPAHs (39.4-78.1%) in majority of firehouses; benzo[a]pyrene, the marker of carcinogenic PAHs, accounted with 1.5-10%. Statistically positive significant correlations (r≥0.733, p≤0.025) were observed between ΣPAHs and urinary ΣOH-PAHs for firefighters of four fire stations suggesting that, at these sites, indoor air was their major exposure source of PAHs. Firefighter's personal exposure to PAHs at Portuguese fire stations were well below the existent occupational exposure limits. Also, the quantified concentrations of post-shift urinary 1-hydroxypyrene in all firefighters were clearly lower than the benchmark level (0.5μmol/mol) recommended by the American Conference of Governmental Industrial Hygienists.

Design and Pilot Study for an Efficient High-Throughput Automated Computer-Vision Guided Intelligent De-Calyxing Machine for Post-Harvest Strawberry Processing

Strawberries harvested for processing as frozen fruits are currently de-calyxed manually in the field. This process requires the removal of the stem cap with green leaves (i.e. the calyx) and incurs many disadvantages when performed by hand. Not only does it necessitate the need to maintain cutting tool sanitation, but it also increases labor time and exposure of the de-capped strawberries before in-plant processing. This leads to labor inefficiency and decreased harvest yield. By moving the calyx removal process from the fields to the processing plants, this new practice would reduce field labor and improve management and logistics, while increasing annual yield. As labor prices continue to increase, the strawberry industry has shown great interest in the development and implementation of an automated calyx removal system. In response, this dissertation describes the design, operation, and performance of a full-scale automatic vision-guided intelligent de-calyxing (AVID) prototype machine. The AVID machine utilizes commercially available equipment to produce a relatively low cost automated de-calyxing system that can be retrofitted into existing food processing facilities. This dissertation is broken up into five sections. The first two sections include a machine overview and a 12-week processing plant pilot study. Results of the pilot study indicate the AVID machine is able to de-calyx grade-1-with-cap conical strawberries at roughly 66 percent output weight yield at a throughput of 10,000 pounds per hour. The remaining three sections describe in detail the three main components of the machine: a strawberry loading and orientation conveyor, a machine vision system for calyx identification, and a synchronized multi-waterjet knife calyx removal system. In short, the loading system utilizes rotational energy to orient conical strawberries. The machine vision system determines cut locations through RGB real-time feature extraction. The high-speed multi-waterjet knife system uses direct drive actuation to locate 30,000 psi cutting streams to precise coordinates for calyx removal. Based on the observations and studies performed within this dissertation, the AVID machine is seen to be a viable option for automated high-throughput strawberry calyx removal. A summary of future tasks and further improvements is discussed at the end.

Chronic exposure to sub-lethal concentration of a glyphosate-based herbicide alters hormone profiles and affects reproduction of female Jundia (Rhamdia quelen)

This work was carried out to verify the effect of a glyphosate-based herbicide on Jundia hormones (cortisol, 17 beta-estradiol and testosterone), oocyte and swim-up fry production. Earthen ponds containing Jundia females were contaminated with glyphosate (3.6 mg/L); blood samples were collected from eight females from each treatment immediately before, or at 1, 10, 20 30 and 40 days following contamination. A typical post-stress rise in cortisol levels was observed at the 20th and 40th days following exposure to glyphosate. At the 40th day, 17 beta-estradiol was decreased in the exposed females. A similar number of oocytes were stripped out from females from both groups, however, a lower number of viable swim-up fry were obtained from the herbicide exposed females, which also had a higher liver-somatic index (LSI). The results indicate that the presence of glyphosate in water was deleterious to Rhamdia quelen reproduction, altering steroid profiles and egg viability. (c) 2006 Elsevier B.V. All rights reserved.