Significant rainfall decreases and variations of the atmospheric circulation in the Mediterranean (1950–2000)

This paper aims at identifying the link between significant rainfall decreases (1950–2000) in the Mediterranean basin and the atmospheric circulation at the 500 hPa level. The months and seasons of the subregions with significant rainfall decrease during this period have been identified previously (Norrant and Douguédroit, Theor Appl Climatol 83(1–4):89–106, 2006): October in the Mediterranean Iberia, March in the Atlantic Iberia, January and winter in Greece, and winter in the Near East. Canonical Correlation Analyses based on the monthly and daily data records from 62 rainfall stations and 138 grid points at the 500 hPa level over a Euro-Atlantic window were first calculated to define the TeleConnection Patterns explaining significant regional rainfall decreases. Then, 500 hPa level weather types (ZWTs) of the rainy days with important or little rainfall associated with each Teleconnection Pattern were identified in each subregion. Rainfall-causing disturbances from the Atlantic reach Iberia directly; some of them are regenerated if they reach the Mediterranean. Other disturbances are generated locally near Greece and the Near East (Meteorological Office in Weather in the Mediterranean I: general meteorology, Her Majesty’s Stationery Office, London, 1962). The relationship between significant rainfall decreases and the corresponding 500 hPa level appears to be a nonlinear phenomenon. In all of the studied subregions, a break during the 1970s separates two subperiods differing significantly from each other. Rainfall decrease is due to the higher frequency of important rainfall ZWTs over low rainfall ZWTs, during the first period, which the opposite is true during the second period. Such an inversion could be partially linked with the prevailing North Atlantic Oscillation-positive phase during the last quarter of the twentieth century.     

Rhizospheric mobilization and plant uptake of radiocesium from weathered micas: II. Influence of mineral alterability

Acute K depletion in the rhizosphere can lead to increased root uptake of radiocesium. Two processes can govern this increase: the very low uptake of potassium and the weathering of Cs-fixing clay minerals. Their respective importance is, however, unknown. We investigated the effects of these processes on radiocesium mobilization by roots of willow (Salix viminalis L.) from three micas: muscovite, biotite, and phlogopite. Willows were grown in a mixed quartz-mica substrate with the three respective (134)Cs-contaminated micas as sole sources of potassium and radiocesium. After 7 wk of plant growth, the micas were partially weathered. The degree of mica weathering and the prevalent potassium concentration in the solution increased in the order muscovite (5-11 microM K) < biotite (25-32 microM K) < phlogopite (25-35 microM K). The mobilization and root uptake of radiocesium were negligible with muscovite but increased in the same order. These results show that mica weathering directly and chiefly governs the mobility of radiocesium in K-depleted rhizosphere soil. The low mobility of trace Cs in the muscovite rhizosphere is linked with the dioctahedral character of this mica, and hence to its very low alterability.     

Nitrous oxide emission out of grassland

Grazed grassland which received 295 kg ha^–1 N-fertilizer (NH₄NO₃), split-applied, was used to measure nitrous oxide emission. The closed box method was used. At the same time, also soil cores were taken for incubation in the presence of acetylene. During 280 days in 1992, a total emission of 8.4 kg N₂O-N ha^–1 was found. This was close to 50 % of the total denitrification, which was 18.7 kg (N₂O+N₂)-N ha^–1 over 280 days. A variability study on N₂O emission was carried out on a surface of 1, 100 and 10,000 m², respectively. This study confirmed the lognormal distribution of data with variation coefficients of 20 to 25%. It was also found that the effect of application of 200 kg KNO₃-N on N₂O emission was limited to 2 weeks upon fertilization. It more than doubled the emission rate during this period.     

Laboratory study of the emission of NO and N2O from some Belgian soils

The NO, NO₂ and N₂O emission was measured, upon application of nitrate, ammonium and both, to four Belgian soils with different characteristics. The addition of NH ₄ ⁺ caused higher NO and N₂O emissions than the addition of no nitrogen, or the addition of NO ₃ ^– . In contrast to the two soils with a pH of approximately 8 the two soils with a pH around 6 showed a considerable delay in production of both NO and N₂O upon the application of the ammonium, probably due to the lag-period of nitrification. The soils with a pH of 8 gave higher emissions on the application of NH ₄ ⁺ than the soils with a pH of 6. The emission of NO₂ was found to be considerably lower than the NO emission from the soils. The NO/NO₂ ratio varied between 5–25 at considerable NO emissions (>50 nmol kg^–1). In the controls of soil 1 and soil 2, which showed very low NO emissions ratios of <1 were observed. The N₂O/NO ratios varied between 5–20 when NO emissions were considerable (>50 nmol kg^–1). Soil 3 and 4 gave lower N₂O/NO ratios than soil 1 and 2. In the controls of soil 1 and soil 2, at low NO emissions, N₂O/NO ratios of >300 were observed. Soil 3 and 4 gave higher NO/NO₂ and lower N₂O/NO ratios than soil 1 and 2.     

Fetal fibrochondrogenesis at 26 weeks' gestation

An Erratum has been published for this article in Prenatal Diagnosis 22(13) 2002, 1241. Fibrochondrogenesis is a rare and lethal osteochondrodysplasia with an autosomal recessive mode of inheritance. We report a male fetus in which the diagnosis of lethal osteochondrodysplasia was suspected on prenatal ultrasound and radiological examinations during the second trimester of pregnancy. After termination of pregnancy, fibrochondrogenesis was diagnosed by radiological examination and histological study of fetal bones. Interwoven fibrous septa and fibroblastic degeneration of chondrocytes are pathognomonic. The recurrence rate is 25% and accurate diagnosis is necessary to enable genetic counselling. Copyright © 2002 John Wiley & Sons, Ltd.     

Case report: a prenatal case of Jarcho–Levin syndrome diagnosed during the first trimester of pregnancy

The Jarcho–Levin syndrome is a specific form of spondylocostal/spondylothoracic dysostosis. There have been various classifications of this syndrome. We present the case of a severe prenatal Jarcho–Levin syndrome, diagnosed by ultrasound examination during the first trimester of pregnancy in a family with no previous medical history of an affected child. X-ray exploration, high-resolution spiral computed tomography and autopsy confirmed the diagnosis. Copyright © 2003 John Wiley & Sons, Ltd.     

Generations as social categories: An exploratory cognitive study of generational identity and generational stereotypes in a multigenerational workforce

Even though the academic press recognizes generational diversity and its consequences, the related findings are fractured, and research is incomplete regarding methodology and theoretical background. In adopting a social identity perspective concerning groups and self‐conception, we argue that the social identity perspective is in line with generational identity theory. Employing a cognitive mapping method (repertory grid technique, mixed methods), the present study taps into three generations (Baby Boomers, Generation X, and Generation Y) of Belgian managers' minds and demonstrates how they perceive their own and the two other generations. Our research reveals that perceptions of their own and other generations may direct social categorization and generational stereotypes of the in‐group and out‐group(s), that some of these stereotypes can be enacted, and that generational stereotypes do not necessarily coincide with age‐based stereotypes. Several metapatterns in the stereotypes are revealed as well. Hence, we contribute to the emerging field of research that calls for an identity‐based approach rather than a cohort‐based approach to generations and that validates the argument that generations as a workplace phenomenon must be considered a legitimate phenomenon. Insights into generations as social categories give a richer view of the interrelationships between generations in multigenerational situations at work.     

Unexpected effects of sublethal doses of insecticide on the peripheral olfactory response and sexual behavior in a pest insect

Pesticides have long been used as the main solution to limit agricultural pests, but their widespread use resulted in chronic or diffuse environmental pollutions, development of insect resistances, and biodiversity reduction. The effects of low residual doses of these chemical products on organisms that affect both targeted species (crop pests) but also beneficial insects became a major concern, particularly because low doses of pesticides can induce unexpected positive—also called hormetic—effects on insects, leading to surges in pest population growth at greater rate than what would have been observed without pesticide application. The present study aimed to examine the effects of sublethal doses of deltamethrin, one of the most used synthetic pyrethroids, known to present a residual activity and persistence in the environment, on the peripheral olfactory system and sexual behavior of a major pest insect, the cotton leafworm Spodoptera littoralis. We highlighted here a hormetic effect of sublethal dose of deltamethrin on the male responses to sex pheromone, without any modification of their response to host-plant odorants. We also identified several antennal actors potentially involved in this hormetic effect and in the antennal detoxification or antennal stress response of/to deltamethrin exposure.     

Modeling PAH uptake by vegetation from the air using field measurements

We examined PAH uptake by Norway spruce needles following the emergence of new buds in spring 2004–June 2005. Atmospheric PAH concentrations (gaseous phase and particle-bound) were monitored during this period, and PAH concentrations from these three environmental media were then used to calculate deposition and transfer velocities. Benzo(a)pyrene was found almost exclusively associated to particles and thus was used to determine a particle-bound deposition velocity of 10.8 m h^?1. PAHs present in both compartments had net gaseous transfer velocities ranging from negligible values to 75.6 m h^?1 and correlated significantly with log K_OA. The loss velocities thereafter calculated were found to be higher for more volatile PAHs. Using the calculated average atmospheric PAH concentrations and deposition velocities, it was thus possible to model PAH uptake by vegetation through time. We demonstrate that this approach can be used to determine deposition velocities without the use of a surrogate surface. In considering both particulate-bound and gaseous deposition processes this model can be used not only to study air–foliage exchange of semi-volatile organic compounds, but also to illustrate the relative contribution of gaseous deposition and particulate-bound deposition in the overall atmospheric vegetation uptake of semi-volatile organic compounds.