Search results for "Lead"
showing 10 items of 1360 documents
Chronology of early Archaean granite-greenstone evolution in the Barberton Mountain Land, South Africa, based on precise dating by single zircon evap…
1991
We report precise 207Pb/206Pb single zircon evaporation ages for low-grade felsic metavolcanic rocks within the Onverwacht and Fig Tree Groups of the Barberton Greenstone Belt (BGB), South Africa, and from granitoid plutons bordering the belt. Dacitic tuffs of the Hooggenoeg Formation in the upper part of the Onverwacht Group yield ages between 3445 +/- 3 and 3416 +/- 5 Ma and contain older crustal components represented by a 3504 +/- 4 Ma old zircon xenocryst. Fig Tree dacitic tuffs and agglomerates have euhedral zircons between 3259 +/- 5 and 3225 +/- 3 Ma in age which we interpret to reflect the time of crystallization. A surprisingly complex xenocryst population in one sample documents …
Are the most dedicated nurses more vulnerable to job insecurity? Age-specific analyses on family-related outcomes.
2013
Aim To examine the moderating roles of job dedication and age in the job insecurity–family-related well-being relationship. Background As job insecurity is a rather permanent stressor among nurses nowadays, more research is needed on the buffering factors alleviating its negative effects on well-being. Methods A total of 1719 Finnish nurses representing numerous health care organisations participated in this cross-sectional study. Moderated hierarchical regression analysis was used to examine the associations. Results Nurses’ younger age and low job dedication operated as protective factors against the negative effect of high job insecurity on parental satisfaction. The effect of job dedica…
Factors Affecting Attitudes towards Older People in Undergraduate Nursing Students
2021
Background: The population of older people is increasing worldwide. The social and healthcare systems need many nurses to care for the elderly. Positive attitudes increase the preference to work with older people and improve the quality of care. This study describes attitudes towards the elderly in a sample of nursing students, and analyzes the potential factors influencing these attitudes. Methods: A cross-sectional study was carried out in nursing students during the academic course 2017–2018. Kogan’s Attitude Toward Old People Scale was used to assess student attitudes towards older people. Results: The study included 377 undergraduate nursing students, of which 75.9% were women. The mea…
Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852).
1994
Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g…
Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues.
1988
The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Al…
Cadmium, mercury, and lead effects on gill tissue of freshwater crayfishProcambarus clarkii (girard)
1989
Intermolt adult crayfish P. clarkii were used for this work. After acclimatization to laboratory conditions crayfish were exposed to sublethal concentrations of cadmium, mercury, and lead for 96 h. Gills of control and exposed crayfish were removed and ATPase activity and oxygen uptake rate were determined. Structural damage of gill filaments was also observed. Gill tissue respiration rates were measured for individual crayfish using a Gilson differential respirometer. Lead causes a decrease of gill oxygen uptake, but neither cadmium nor mercury seems to affect it at the concentrations employed. Although all metals studied alter gill filament structure, lead damage is the most apparent. In …
A French and U.S. Comparative Overview of the Critical Concerns of Community College Students and Leaders during the Global Pandemic
2021
International audience
Globalization and leadership and management: a comparative analysis of primary schools in England and Finland
2006
This article analyses the impact of processes of globalization on both policy and practice in relation to primary school leadership and management in England and Finland. Data are drawn from case study research carried out from 1994–1996 in six schools in Finland and six schools in England and a follow‐up study on teacher professionalism (2001–2002) that involved 37 of the original participants being re‐interviewed. The article contributes to the ongoing debate concerning the extent to which global trends lead to homogeneity in educational systems or a ‘glocalized’ response. Such a glocalized response is derived not only from different cultural mediations at the national policy level but al…
Interaction of metal ions with N-glycosylamines: isolation and characterization of the products of 4,6-O-benzylidene-N-(o-carboxyphenyl)-β-D-glucopyr…
2001
Metal-ion complexes of Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Pb2+, Cd2+, Hg2+ with 4,6–O–benzylidene–N–(o–carboxyphenyl)–β–D–glucopyranosylamine were synthesized and isolated as solid products and characterized by analytical means as well as by spectral techniques, such as, 1H and 13C NMR, FTIR, absorption, FAB mass spectrometry, optical rotation and CD. While the alkali metal ions formed ML type of complexes, the other metal ions formed ML2 type complexes. Molecular weights of the complexes of Li+, Na+ and K+ were established based on the molecular-ion peaks in the FAB mass spectra. The saccharide portion remians in the β-anomeric form even after the complexation. The spectral data, as well as t…
Synthesis and evaluation of a glibenclamide glucose-conjugate: a potential new lead compound for substituted glibenclamide derivatives as islet imagi…
2007
The search for novel SUR1-ligands originates from the idea to influence the in vivo behaviour by adding new structural moieties to the glibenclamide structure while preserving its binding affinity. Important application of novel conjugates might be their use as radioactively labelled tracer probes in the non-invasive investigation of the islet mass. It is known that the imaging quality of a tracer could be improved by increasing its hydrophilicity, which leads to a reduced plasma protein binding and diminished the unspecific uptake by various organs. In this study the glucose molecule was chosen as a substitute of glibenclamide to enhance hydrophilicity. As expected glucose conjugation lead…