Evaluation of the Greenland AMAP programme 1994-1995, by use of power analysis (illustrated by selected heavy metals and POPs)

The levels of PCBs, HCB, HCHs, DDTs, Cd, Pb, Hg and Se, and especially the variability in biota obtained during Phase 1 of the Greenland AMAP-programme have been used to illustrate the ability of the programme to detect differences in contaminant levels over time. The statistical power of t-tests of contaminant levels are illustrated according to various scenarios of magnitude of change, significance level and sample size. The statistical power of various time series of contaminant levels to detect linear trends in mean log-concentrations, including a random between-year variation component, is illustrated. We conclude that the ability to detect differences is rather poor for many combinations of contaminants and media, and that long time series are needed before temporal trends are likely to be detected.     

Employment discrimination: Authority figures' demographic preferences and followers' affective organizational commitment.

The authors used theories of organizational commitment and obedience to authority to explain employment discrimination. In Study 1, employees participated in an experimental simulation of their work. An organizational authority's demographic preferences led to employment discrimination. As expected, affective organizational commitment moderated this effect, such that it was stronger for more committed employees. In Study 2, another sample of employees completed a survey that included an employment discrimination scenario. A model of linkages from affective organizational commitment to submissiveness to organizational authorities to employment discrimination fit the data well, after controlling for prejudicial attitudes and authoritarianism. Submissiveness to organizational authorities mediated the relationship between affective organizational commitment and employment discrimination. The authors discuss the importance of studying employment discrimination as an organizational and not just an intergroup phenomenon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lead, zinc, cadmium, mercury, selenium and copper in Greenland caribou and reindeer (Rangifer tarandus)

Samples of caribou and reindeer muscle (127 samples) and liver (126 samples) were collected from four locations during two seasons plus 3 years in Greenland. The levels of lead, zinc, cadmium, mercury, selenium, and copper were determined, and analyzed in relation to location, two seasons, age and year of sampling. The lead concentrations (geometric mean) ranged from below the detection limit to 0.007 microgram/g wet weight (wet wt.) in muscle and from 0.027 to 0.926 microgram/g wet wt. in liver. Zinc geometric mean concentrations ranged from 17.5 to 39.6 micrograms/g wet wt. in muscle and from 23.2 to 31.7 micrograms/g wet wt. in liver. For cadmium, the geometric mean concentrations were at, or below the detection limit in muscle, while concentrations in liver ranged from 0.121 to 0.695 microgram/g wet wt. Mercury levels ranged from 0.003 to 0.043 microgram/g wet wt. in muscle and from 0.040 to 0.618 microgram/g wet wt. in liver. Selenium concentration levels in muscle ranged from 0.030 to 0.252 microgram/g wet wt., and from 0.085 to 0.984 microgram/g wet wt. in liver. Copper levels in muscle ranged from 2.09 to 3.60 micrograms/g wet wt., and from 21.8 to 71.0 micrograms/g wet wt. in liver. Mercury concentrations were higher than those found at lower latitudes in Norway and Canada, especially in Isortoq in southern Greenland. Selenium levels were also high compared to other Arctic regions. Concentrations of lead, zinc, cadmium and copper are similar to those reported in caribou from Canada and Norway. Concentrations of elements generally decreased in the following order: Isortoq > Akia > Itinnera > Kangerlussuaq, and there was only found minor variation in the annual levels during 3 years in Itinnera. Late winter levels were generally significantly higher than early winter levels especially in the lichen-rich localities, and it is suggested that the availability of lichens as winter forage is the key determining the level of elements. Accordingly, when using caribou and reindeer as monitoring organism, knowledge of winter forage is very important for interpretation of results.     

Cadmium toxicity to ringed seals (Phoca hispida): an epidemiological study of possible cadmium-induced nephropathy and osteodystrophy in ringed seals (Phoca hispida) from Qaanaaq in Northwest Greenland

The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose of the study was to determine whether cadmium-induced damage in the kidneys and the skeletal system could be detected among 100 ringed seals from Northwest Greenland. The cadmium concentrations in the kidney cortex ranged from 0 to 248 microg/g wet weight (mean=44.5, N=100) in the 99 kidneys examined. Experience from cadmium-poisoned humans and laboratory mammals indicates that concentrations above 50-200 microg/g wet wt. may induce histopathological changes. Overall, 31 of the ringed seals had cadmium concentrations in the kidney cortex above 50 microg/g wet wt., 11 had concentrations above 100 and one had a concentration above 200 microg/g wet wt. Obvious histopathological changes (categorised mainly as glomerulonephritis) were found in 10 of the seals; however, none of these changes could be attributed to cadmium-induced renal damage (mainly tubulopathy) as described for other species. Damage to the proximal kidney tubules is known to induce demineralisation of the skeletal system (Fanconi's syndrome). Therefore, the three lowest lumbar vertebrae were scanned in 91 seals to measure the content of calcium. The 10 cases of nephropathy could neither be linked to the degree of mineralisation of the skeleton nor to the cadmium concentrations. Furthermore, the degree of mineralisation of the skeleton was not correlated with the cadmium concentration, age or sex. It can therefore be concluded that despite high levels of cadmium, none of the ringed seals showed any signs of cadmium-induced nephropathy or osteodystrophy. This might be explained by the composition of the ringed seals diet, which contains high levels of vitamin D, calcium, phosphorus, zinc, selenium and protein. These elements are all likely to counteract cadmium-induced damage. It is speculated that ringed seal are not particularly vulnerable to osteodystrophy, due to their continuous growth (bone mineralisation) throughout life and the oestrogen hormonal activity of females throughout life.     

Trends in fluctuating asymmetry in East Greenland polar bears (Ursus maritimus) from 1892 to 2002 in relation to organohalogen pollution

Fluctuating asymmetry (FA) was studied in skulls of 283 polar bears (Ursus maritimus) sampled in East Greenland from 1892 to 2002. Fourteen metric bilateral traits in skull and lower jaw were measured and compared between polar bears born until 1960 (n = 94) and from 1961 (n = 189). The period 1892-1960 was chosen to represent a period prior to appearance of organohalogens (polychlorinatedbiphenyls [PCBs], dichlorodiphenyltrichloroethanes [DDTs], hexacyclohexanes [HCHs], chlordanes [CHLs], hexachlorobenzene [HCB], polybrominateddiphenylethers [PBDEs] and dieldrin) originating from long-range transport to East Greenland from southern latitudes. The period 1961-2002 represents the period when polar bears have been exposed to organohalogens. During this latter period, the level of organochlorines is believed to have increased from 1960 to the late 1980s followed by a likely decrease from 1990 to 2002. Within this later period, other compounds such as, e.g., polybrominated flame retardants are believed to have increased throughout the period. Two different analysis showed, that the degree of fluctuating asymmetry did not differ statistically between the two periods in ten of thirteen traits (one trait excluded due to high measurement error). In fact, when significant differences were found in four of the traits, the fluctuating asymmetry was lower in skulls sampled after 1960. The degree of fluctuating asymmetry was higher in adults than in subadults for 6 of the 14 traits, whereas a higher degree of fluctuating asymmetry was found for only one trait in one of the analyses for subadults relative to adults. Females had a higher degree of fluctuating asymmetry than males in one trait. A time trend analysis did find fluctuations over time for five traits but the relationship was weak as the trend appeared to occur by chance due to the high number of regressions analysed (n = 42). A correlation analysis of FA versus the sum concentrations of various classes of organohalogens in adipose tissue from a subsample of 94 recently collected polar bears (1999-2002) did not show a trend either. Hence, the present study could not document a relationship between skull asymmetry in polar bears and periods with different exposure to organohalogens. These findings are possibly influenced by nutritional status, genetic factors, a subeffect exposure of organohalogens or confounded by other environmental factors (e.g. temperature) within the two investigated periods.     

Mueller matrix measurements of algae with different shape and size distributions

The full Mueller matrix was measured to obtain the polarization state of the scattered light for a variety of algae with different shapes, wall compositions, sizes, and refractive indices. The experimental setup was a multiple laser Mueller matrix ellipsometer, by which measurements were performed for scattering angles from 16° to 160° sampled at every second degree for wavelengths of 473?nm and 532?nm. Previously, the polarization of light scattered from microalgae was investigated only for a few species, and the Mueller matrix was found to have little variation between the species. In our work a total of 11 algal species were investigated, representing diatoms, dinoflagellates, coccolithophorids, green algae, and a cryptophyte. The selection of species was made to obtain high variability in shape, size, cell wall, and refractive index. As in previous investigations, very small variations were found between species for most of the Mueller matrix elements, but noticeable variations were found for M(11), (M(12)+M(21))/2 and (M(33)+M(44))/2.     

Contrast imaging by non-overlapping dual frequency band transmit pulse complexes

SURF contrast imaging, as described previously in the literature, is a contrast agent detection technique achieved by processing of the received signals from transmitted dual frequency band pulse complexes with overlapping high-frequency (HF) and low-frequency (LF) pulses. The transmitted HF pulses are used for image reconstruction, whereas the transmitted LF pulses are used to manipulate the scattering properties of the contrast agent. As with harmonic contrast agent detection techniques, nonlinear wave propagation will, in most situations, also limit the specificity with the SURF contrast technique when transmitting overlapping HF and LF pulses. The present paper proposes an alternative SURF contrast imaging technique using transmit dual frequency band pulse complexes with non-overlapping HF and LF pulses. If the frequency of the LF manipulation pulse is close to the bubble resonance frequency, numerical simulations indicate a significant ring-down effect of the LF bubble radius response. Utilizing this bubble ring-down effect and transmitting the HF pulse just after the LF pulse, a contrast agent specificity approaching infinity accompanied by a contrast agent sensitivity only for contrast bubbles having resonance frequencies within a narrow frequency range may be obtained.     

“System-of-systems” approach for interdependent critical infrastructures

The study of the interdependencies within critical infrastructures (CI) is a growing field of research as the importance of potential failure propagation among infrastructures may lead to cascades affecting all supply networks. New powerful methods are required to model and describe such “systems-of-systems” (SoS) as a whole. An overall model is required to provide security and reliability assessment taking into account various kinds of threats and failures. A significant challenge associated with this model may be to create “what-if” scenarios for the analysis of interdependencies. In this paper the interdependencies between industrial control systems (ICS), in particular SCADA (Supervisory Control and Data Acquisition), and the underlying critical infrastructures to address the vulnerabilities related to the coupling of these systems are analyzed. The modeling alternatives for system-of-systems, integrated versus coupled models, are discussed. An integrated model contains detailed low level models of (sub)systems as well as a high level model, covering all hierarchical levels. On the other hand, a coupled model aggregates different simulated outputs of the low level models as inputs at a higher level. Strengths and weaknesses of both approaches are analyzed and a model architecture for SCADA and the “system under control” are proposed. Furthermore, the HLA simulation standard is introduced and discussed in this paper as a promising approach to represent interdependencies between infrastructures. To demonstrate the capabilities of the HLA standard for the interdependencies study, an exemplary application and some first results are also briefly presented in this paper.     

Infrastructure for Intelligent Automation Services in the Smart Grid

The electricity grid is undergoing a radical transformation from a production-driven to a demand-driven energy delivery platform known as the smart grid. The integration of a large amount of renewable and distributed energy resources, together with new patterns of electricity production, accentuates the need for research in information and communication technologies to control bi-directional energy flows. The European FP7 project: “Energy Demand Aware Open Services for Smart Grid Intelligent Automation” is contributing to this research by providing an intelligent infrastructure for service deployment for the smart grid. The project defines a system architecture that provides interoperability between wireless sensors in home area networks connected over the Internet to a service provider function deployed in a cloud infrastructure. A key component in this infrastructure is the Home Energy Controlling Hub that, on the one hand, provides a platform for monitoring and aggregation of electricity consumption data from devices and appliances and, on the other hand, is the link between the deployed intelligent automation services and the home. To ensure openness and simplicity, the proposed infrastructure is based on the representational state transfer style architecture. This is adopted by implementing the emerging ZigBee IP and Smart Energy Profile 2.0 standards that to a wide extend conform with the Internet Protocol suite and state-of-the art web services development.     

Detection of foreign fat in milk fat II. Quantitative evaluation of foreign fat mixtures

Summary Based on gas chromatographic analysis of triacylglycerol composition of 755 different milk fat samples, formulae were derived from statistical evaluations. They allow quantitative detection of greatly differing foreign fat additions to milk fat by insertig defined triacylglycerol contents of a fat to be analyzed. Further, any combination of different foreign fats, consisting. e.g., of a mixture of medium- and long-chain triacylglycerols can be detected by using this method. For the widely varying foreign fat mixtures, limits of detection between 2–5% were established. For 23 different additions (3–15%) of individual vegetable foreign fats or animal depot fats, as well as for 33 foreign fat mixtures (4–7% addition) added to unknown milk fats from varying feeding periods, absolute mean deviations of 0.7–0.8% were found.

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Fremdfettnachweis in Milchfett II. Quantitative Bestimmung von Fremdfettgemischen

Zusammenfassung Basierend auf der gaschromatographisch bestimmten Triglyceridzusammensetzung von 755 verschiedenen Milchfettproben sind mit statistischen Auswertungen Triglyceridformeln abgeleitet worden, die durch das Einsetzen bestimmter Triglyceridanteile eines zu prüfenden Fettes den quantitativen Nachweis verschiedenster Fremdfettzusätze zum Milchfett zulassen. Darüber hinaus können mit der Methode auch beliebige Kombinationen verschiedener Fremdfette, die z. B. aus einer Mischung von mittel- und langkettigen Triglyceriden bestehen, nachgewiesen werden. Für die verschiedensten Fremdfettgemische ergaben sich Nachweisgrenzen von 2–5%. Bei 23 unterschiedlichen Zusätzen (3–15%) einzelner pflanzlicher Fremdfette oder von tierischen Depotfetten sowie von 33 Fremdfettgemischen (4–7% Zusatz) zu unbekannten Milchfetten aus verschiedensten Fütterungsperioden wurden absolute mittlere Abweichungen von 0,7–0,8% festgestellt.