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Showing papers by "Stockholm University published in 1991"


Journal ArticleDOI
01 Aug 1991-Tellus A
TL;DR: In this paper, a three-dimensional global model for estimating the SO 4 = aerosol mass concentration, along with previously-acquired information on the scattering and back-scattering coefficients per unit mass concentration are presented.
Abstract: Anthropogenic sulfate (SO 4 = ) aerosol particles play two potential roles in the radiative climate of the earth. In cloud-free air, SO 4 = particles scatter sunlight, some of which is lost to space, thereby reducing solar irradiance at the ground. The same particles can act as cloud condensation nuclei (CCN), the number concentration of which is an important determinant of cloud albedo. This albedo effect, in turn, also influences incoming short-wave solar radiation. Development of a three-dimensional global model for estimating the SO 4 = aerosol mass concentration, along with previously-acquired information on the scattering and back-scattering coefficients per unit mass concentration allow calculation of the effects of anthropogenic SO 4 = aerosol on clear-sky optical depth. Subsequently, this can be used to estimate the change in hemispheric and global average reflected solar radiation. The conclusion is that the change of reflected solar flux due to anthropogenic SO 4 = averaged over the Northern Hemisphere is ca. − 1.1 Wm -2 , which is comparable but opposite in sign to the present-day radiative forcing by anthropogenic CO 2 , + 1.5 Wm -2 . Because of the spatial variability of the anthropogenic SO 4 = distribution, its meteorological effects must be studied regionally. That is, global models with regional resolution and regional data are required. Unlike the direct effect on solar irradiance, the relationship of CCN number concentration to mass concentration is not known. Thus it is not yet possible to make quantitatively reliable statements about anthropogenic forcing of cloud albedo, although there is qualitative evidence that the CCN effect may also be substantial. DOI: 10.1034/j.1600-0870.1991.00013.x

760 citations


Journal ArticleDOI
19 Apr 1991-Cell

561 citations


01 Jan 1991
TL;DR: An update of the scientific discussions presented in Chapter 2 of the Intergovernmental Panel on Climate Change (IPCC) report is presented in this paper, where the atmospheric radiative and chemical species of significance for climate change are discussed.
Abstract: An update of the scientific discussions presented in Chapter 2 of the Intergovernmental Panel on Climate Change (IPCC) report is presented. The update discusses the atmospheric radiative and chemical species of significance for climate change. There are two major objectives of the present update. The first is an extension of the discussion on the Global Warming Potentials (GWP's), including a reevaluation in view of the updates in the lifetimes of the radiatively active species. The second important objective is to underscore major developments in the radiative forcing of climate due to the observed stratospheric ozone losses occurring between 1979 and 1990.

524 citations


Journal ArticleDOI
TL;DR: To facilitate the theoretical treatment of such a situation where the total population is subdivided into segments with different reproductive rates, a method for estimating the overall effective size from the effective sizes of the contributing segments is presented.
Abstract: The genetically effective population size (Ne) is a key parameter in conservation biology, because the rate of inbreeding (AF), and thereby the rate of loss of genetic heterozygosity, is proportional to the inverse of the effective number (AF = 1/2Ne; e.g., Crow & Kimura 1970). The importance of maintaining large effective sizes of natural and captive populations is reflected by the considerable fraction of the literature on biological conservation that focuses on that issue (e.g., Flesness 1977; Ryman & St'ahl 1980; Ryman et al. 1981; Frankel & Soule 1981; Soule et al. 1986; Allendorf & Ryman 1987; Lande & Barrowclough 1987). This note addresses a problem in conservation genetics that, to our knowledge, has not been previously recognized: the reduction of the genetically effective population size that may result from breeding-release programs aimed at supporting natural populations. Typically, in such programs a fraction of the wild parents (or their offspring) are brought into captivity for reproduction or preferential survival, and the offspring are released into the natural habitat where they mix with wild conspecifics. We refer to this practice as supportive breeding, stressing the fact that no exogenous genes are introduced into the overall population. The logic of supportive breeding is generally to increase survival through breeding in a protected captive environment. However, this process also implies that the reproductive rate of one segment of the overall population is favored, which results in an increase in the total variance of family size, a parameter of critical importance to the genetically effective size of the population. The amount of change of effective population number that may result from manipulating the variance of family size can be derived from the distributions of family size among the wild and captive breeders (Crow & Kimura 1970), but in many situations either or both of those distributions are unknown. Rather, the manager may have some rough idea of the approximate effective sizes of the wild and captive populations and of their relative contributions to the combined offspring population. Such a situation is frequently encountered in, for example, the field of fishery management; hatchery records provide a basis for estimating the effective number of parents of the released fish, the effective size of the wild population may be at least crudely approximated from field counts of the number of spawners, and tagging data contribute information on the proportion of hatchery fish in the offspring generation. To facilitate the theoretical treatment of such a situation where the total population is subdivided into segments with different reproductive rates, we present a method for estimating the overall effective size from the effective sizes of the contributing segments. Paper submittedJuly 30, 1990; revised manuscript acceptedJanuary 17, 1990.

519 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used an Eulerian transport model, the MOGUNTIA model, with a horizontal resolution of 10° longitude by 10° latitude and with 10 layers in the vertical between the surface and 100 hPa.
Abstract: The tropospheric part of the atmospheric sulfur cycle has been simulated in a global three-dimensional model. The model treats the emission, transport, chemistry, and removal processes for three sulfur components; DMS (dimethyl sulfide), SO2 and SO4 2− (sulfate). These processes are resolved using an Eulerian transport model, the MOGUNTIA model, with a horizontal resolution of 10° longitude by 10° latitude and with 10 layers in the vertical between the surface and 100 hPa. Advection takes place by climatological monthly mean winds. Transport processes occurring on smaller space and time scales are parameterized as eddy diffusion except for transport in deep convective clouds which is treated separately. The simulations are broadly consistent with observations of concentrations in air and precipitation in and over polluted regions in Europe and North America. Oxidation of DMS by OH radicals together with a global emission of 16 Tg DMS-S yr−1 from the oceans result in DMS concentrations consistent with observations in the marine boundary layer. The average turn-over times were estimated to be 3, 1.2–1.8, and 3.2–6.1 days for DMS, SO2, and SO4 2− respectively.

514 citations


Journal ArticleDOI
TL;DR: The use of in situ hybridization offers a highly sensitive method to study cytokine production in individual cells, but the technqiue is fairly time-consuming and the presence of cytokine mRNA does not guarantee that it will be translated.
Abstract: Cytokine production needs to be evaluated by multiple approaches since all existing methods for quantification are hampered by various drawbacks. Bioassays measure functional properties, but they are rarely monospecific and the results are influenced by inhibitory factors. Techniques based on ELISA and RIA systems are highly specific but do not distinguish between biologically active and inactive substances. Furthennore, these assays determine the extracellular presence of a secreted interieukin, reflecting the net outcome of produced, absorbed and degraded cytokine. The demonstration of a receptor-directed focusing of lymphokine release by helper T cells (Poo et al. 1988) argues for direct cellular approach to cytokine assessment. The use of in situ hybridization offers a highly sensitive method to study cytokine production in individual cells, but the technqiue is fairly time-consuming and the presence of cytokine mRNA does not guarantee that it will be translated.

470 citations


Journal ArticleDOI
TL;DR: This paper showed that people remember details from emotional events differently than details from neutral events, and that emotional events led to different performance than non-emotional events. But, their results were limited to five experiments, and they did not consider the effect of unusual events.
Abstract: Previous research has shown that people remember details from emotional events differently than details from neutral events. However, past research suffers from inadequate equating of the details tested in the emotional and neutral events. In the current five experiments, involving a total of 397 subjects, we equated the to-be-remembered detail information. Subjects in these experiments were presented with a thematic series of slides in which the content of one critical slide in the middle of the series varied. When the critical slide was emotional (a woman injured near a bicycle), compared to neutral in nature (a woman riding a bicycle), subjects were better able to remember a central detail but less able to remember a peripheral detail. To determine whether the emotional event led to different performance simply because it was unusual, we included a third condition, in which subjects saw an “unusual” version of the event (a woman carrying a bicycle on her shoulder). Subjects in the unusual cond...

396 citations


Journal ArticleDOI
TL;DR: Another antibacterial peptide with high activity against both E. coli and Bacillus megaterium is identified and named PR-39 (proline-arginine-rich with a size of 39 residues), which is in excellent agreement with plasma desorption mass spectrometry.
Abstract: We recently isolated from pig intestine and characterized a 31-residue antibacterial peptide named cecropin P1 with activity against Escherichia coli and several other Gram-negative bacteria. The isolation involved a number of batch-wise steps followed by several chromatography steps. The continued investigation of these antibacterial peptides has now yielded another antibacterial peptide with high activity against both E. coli and Bacillus megaterium. Amino acid analysis showed a very high content of proline (49 mol%) and arginine (26 mol%), an intermediate level of phenylalanine and low levels of leucine, tyrosine, isoleucine, and glycine. The primary structure was determined by a combination of Edman degradation, plasma desorption mass spectrometry and C-terminal sequence analysis by carboxypeptidase Y degradation using capillary zone electrophoresis for detection of liberated residues. The calculated molecular mass was 4719.7 Da, which is in excellent agreement with 4719 Da obtained by plasma desorption mass spectrometry. The peptide was named PR-39 (proline-arginine-rich with a size of 39 residues). The lethal concentration of the peptide was determined against six Gram-negative and four Gram-positive strains of bacteria.

339 citations


Journal ArticleDOI
TL;DR: In this article, a factor analysis of a leadership behaviour questionnaire revealed the same pattern of leadership styles in all the participants described their own manager in a 36-item questionnaire; the managers were also rated for managerial competence and the respondent's personal attitude to the manager was given.

283 citations


Journal ArticleDOI
TL;DR: It is proposed that this monoprotic event reflecting the protonation of an amino acid residue, probably histidine-190 on the D2 protein, to which YD is hydrogen bonded, affects the water-oxidizing complex.
Abstract: The effect of protonation events on the charge equilibrium between tyrosine-D and the water-oxidizing complex in photosystem II has been studied by time-resolved measurements of the EPR signal IIslow at room temperature. The flash-induced oxidation of YD by the water-oxidizing complex in the S2 state is a monophasic process above pH 6.5 and biphasic at lower pHs, showing a slow and a fast phase. The half-time of the slow phase increases from about 1 s at pH 8.0 to about 20 s at pH 5.0, whereas the half-time of the fast phase is pH independent (0.4-1 s). The dark reduction of YD+ was followed by measuring the decay of signal IIslow at room temperature. YD+ decays in a biphasic way on the tens of minutes to hours time scale. The minutes phase is due to the electron transfer to YD+ from the S0 state of the water-oxidizing complex. The half-time of this process increases from about 5 min at pH 8.0 to 40 min at pH 4.5. The hours phase of YD+ has a constant half-time of about 500 min between pH 4.7 and 7.2, which abruptly decreases above pH 7.2 and below pH 4.7. This phase reflects the reduction of YD+ either from the medium or by an unidentified redox component of PSII in those centers that are in the S1 state. The titration curve of the half-times for the oxidation of YD reveals a proton binding with a pK around 7.3-7.5 that retards the electron transfer from YD to the water-oxidizing complex. We propose that this monoprotic event reflects the protonation of an amino acid residue, probably histidine-190 on the D2 protein, to which YD is hydrogen bonded. The titration curves for the oxidation of YD and for the reduction of YD+ show a second proton binding with pK approximately 5.8-6.0 that accelerates the electron transfer from YD to the water-oxidizing complex and retards the process in the opposite direction. This protonation most probably affects the water-oxidizing complex. From the measured kinetic parameters, the lowest limits for the equilibrium constants between the S0YD+ and the S1YD as well as between the S1YD+ and S2YD states were estimated to be 5 and 750-1000, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

263 citations


Journal ArticleDOI
TL;DR: Insects respond to live bacteria by the production of a potent antibacterial activity which is due to the synthesis of 15–20 immune proteins, which is taken advantage of both in the purification of 15 inducible immune proteins and in the isolation of immune RNA, used for the preparation of a cDNA library.
Abstract: All higher organisms can in some way defend or protect themselves against their natural flora of bacteria This applies also to insects which have highly effective immune systems, both cellular and humoral Many insects respond to an injection of live, non-pathogenic bacteria with the production of a potent cell-free antibacterial activity (for a review see Boman and Hultmark 1987) This phenomenon was first analysed at the molecular level using as a model system the Cecropia moth, Hyalophora cecropia (hereafter referred to as Cecropia) When a diapausing pupa is immunized it turns on the genes for immunity while the rest of the animal remains in a dormant state Immunized pupae of Cecropia are therefore a system for biological enrichment of the RNA and the proteins which are synthesized from the genes for immunity We have taken advantage of this fact both in the purification of 15 inducible immune proteins and in the isolation of immune RNA, used for the preparation of a cDNA library After a short period of RNA synthesis, the insects respond to live bacteria by the production of a potent antibacterial activity which is due to the synthesis of 15–20 immune proteins

Journal ArticleDOI
TL;DR: Both mental and physical performance was improved by an intake of BCAA during exercise and the effects of exercise on the plasma concentration of the aromatic amino acids were altered when a BCAA supplement was given during the marathon.
Abstract: Previous studies have shown that sustained exercise in human subjects causes an increase in the plasma concentration ratio of free tryptophan: other large neutral amino acids [including the branched-chain amino acids (BCAA)]. This should favour the transport of tryptophan into the brain and also the synthesis of 5-hydroxytryptamine, which is thought to contribute to fatigue during prolonged exercise. A mixture of the three BCAA was given to subjects during a 30-km cross-country race or a marathon (42.2 km) and the effects on mental and physical performances were measured. The mental performance, measured as the performance in the Stroop Colour and Word Test (CWT), was improved after, as compared to before the 30-km cross-country race when a BCAA supplement was given during the race, whereas the CWT scores were similar before and after in the placebo group. The running performance in the marathon was improved for the “slower” runners (3.05 h–3.30 h) when BCAA was taken during the race; however, there was no significant effect on the performance in the “faster” runners (<3.05 h). The results showed that both mental and physical performance was improved by an intake of BCAA during exercise. In addition, the effects of exercise on the plasma concentration of the aromatic amino acids were altered when a BCAA supplement was given during the marathon.

Journal ArticleDOI
TL;DR: A set of strategy profiles is here said to be closed under rational behavior (curb) of it contains all its best replies as mentioned in this paper, and each curb set contains the support of at least one Nash equilibrium in mixed games.

Journal ArticleDOI
TL;DR: The relatively higher root inducing ability of IBA is ascribed to the fact that its level remained elevated longer than that of IAA, even though IBA was metabolized in the tissue, whereas the IBA level remained high throughout the experimental period.
Abstract: The influence of exogenous indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) on the internal levels of these auxins was studied during the first 4 days of adventitious root formation in cuttings of Pisum sativum L. The quantitations were done by high performance liquid chromatography with spectrofluorometric detection. IBA, identified by combined gas chromatography-mass spectrometry (GC-MS), was found to naturally occur in this plant material. The root inducing ability of exogenous IBA was superior to that of IAA. The IAA level in the tissue increased considerably on the first day after application of IAA, but rapidly decreased again, returning to a level twice the control by day 3. The predominant metabolic route was conjugation with aspartic acid, as reflected by the increase in the level of indole-3-acetylaspartic acid. The IBA treatment resulted in increases in the levels of IBA, IAA, and indole-3-acetylaspartic acid. The IAA content rapidly returned to control levels, whereas the IBA level remained high throughout the experimental period. High amounts of indole-3-butyrylaspartic acid were found in the tissue after feeding with IBA. The identity of the conjugate was confirmed by 1H-nuclear magnetic resonance and GC-MS. IBA was much more stable in solution than IAA. No IAA was detected after 48 hours, whereas 70% IBA was still recovered after this time. The relatively higher root inducing ability of IBA is ascribed to the fact that its level remained elevated longer than that of IAA, even though IBA was metabolized in the tissue. Adventitious root formation is discussed on the basis of these findings.

Journal ArticleDOI
01 Feb 1991-Heredity
TL;DR: Brown Trout were compared genetically with landlocked populations in the same drainage system in western Norway, showing larger genetic differentiation between localities than between coexisting life-history types that differ in morphology and ecology.
Abstract: Genetic relationships among landlocked, resident, and anadromous Brown Trout, Salmo trutta L.


Journal ArticleDOI
TL;DR: In this article, the authors report on a study of particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN.
Abstract: We report on a study of inclusive particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN. The production cross sections are determined of pseudo scalar (π±,0, η andK±), scalar (f0(975)), vector (ρ±,0(770), ω(783), ϕ(1020),K*0(892), and\(\bar K^{ * 0} \)(892)), and tensorf0 mesons, of protons and antiprotons, and theΔ++,+,0(1232), and Λ(1520) baryon resonances in the forward hemisphere of the center of mass system, as well as longitudinal and transverse momentum distributions. The results are compared with predictions of the FRITIOF model and with other experimental data.

Journal ArticleDOI
TL;DR: It is concluded that the mitochondrial PPase encoded by PPA2 is essential for mitochondrial function and maintenance of the mitochondrial genome.

Journal ArticleDOI
TL;DR: It appears that insects have evolved a mechanism for the protection of the seminal fluid and the male reproductive tract against microbial infections.
Abstract: In our study of the cecropin locus in Drosophila we have found a gene for a new peptide, andropin, with antibacterial properties. Transcripts from this gene, Anp, could be detected in newly eclosed males and reached steady-state levels after 1 day. Transcription was strongly induced in response to mating and is strictly confined to the ejaculatory duct of adult males. The deduced peptide sequence reveals a hydrophobic amino terminus with striking similarity to the signal peptide of the cecropins. The sequence of the predicted mature andropin shows no direct homology with the cecropins, but the two peptides may have similar secondary structures. We have synthesized the predicted gene product and shown it to be antibacterial. Crude extracts from male genital tracts show a potent bactericidal activity, and electrophoretic separation revealed at least three antibacterial components, one with the same mobility as the synthetic peptide. It appears that insects have evolved a mechanism for the protection of the seminal fluid and the male reproductive tract against microbial infections.

Journal ArticleDOI
01 Feb 1991-Tellus B
TL;DR: In this paper, a series of daily atmospheric aerosol samples collected in southern Sweden between 9 February and 30 May 1988 were used to classify the samples according to source region: Northwest, Western Europe, East, Eastern Europe, or a combination of two regions.
Abstract: Pb 206 /Pb 207 and Pb 208 /Pb 207 isotope ratios were measured in a series of daily atmospheric aerosol samples collected in southern Sweden between 9 February and 30 May 1988. The ratios were observed to vary considerably, depending on the origin of air. 5-day back-trajectories were used to classify the samples according to source region: Northwest, Western Europe, East, Eastern Europe, or a combination of two regions. Significant differences in the isotope ratios were found. Unique signatures based on the Pb 206 /Pb 207 and Pb 208 /Pb 207 ratios could be assigned for each region. The signatures were generally consistent with isotope ratios of Swedish and other European gasolines, and with literature values of the isotope ratios of economically significant lead ores used in Europe. A comparison was made between the regional signatures and the Pb 206 /Pb 207 ratios observed in Arctic aerosol samples. Excellent agreement was observed between the Arctic Pb 206 /Pb 207 ratios (1.160) and an average source signature (1.156) calculated from observations in this study using equal contributions from Western Europe, Eastern Europe, and the East as predicted by a chemical transport model. DOI: 10.1034/j.1600-0889.1991.00004.x

Journal ArticleDOI
TL;DR: In this article, the issue of stability and change in criminal behaviour was investigated using data for registered crime obtained in a Swedish prospective, longitudinal research project, and the relevance of early onset of criminality for criminal behaviour in the long term is discussed.
Abstract: The issue of stability and change in criminal behaviour was investigated using data for registered crime obtained in a Swedish prospective, longitudinal research project. Criminal activity among 709 males was investigated for three time periods: childhood (up to age 14), adolescence (from age 15 to age 20), and early adulthood (age 21-30). The Spearman correlation coefficient, reflecting the stability of registered criminal activity, was 0.40 between childhood and adolescence, 0.34 between childhood and early adulthood, and 0.38 between adolescence and early adulthood. Little specialization of criminal activity over time was revealed. Rather, a diversified crime pattern in early adulthood tended to be preceded by a spread of offences over different types of crime in adolescence. The small group of subjects who had committed offences below age 15, during adolescence, and also in early adulthood were responsible for most of the crime recorded for the total research population. These persistent offenders constituted 5.4 per cent of the total number of subjects, were recorded to have 41 per cent of all registered convictions, and participated in 62 per cent of all the registered crime occasions. Their over-representation with regard to offences committed was relatively uniform across different types of crime, both in adolescence and in early adulthood. Overall, acquiring a record for early delinquency was quite strongly prognostic of future crime. More than three out of four of the subjects who appeared on the police registers before the age of criminal responsibility also showed up there later. The relevance of early onset of criminality for criminal behaviour in the long term is discussed.

Journal ArticleDOI
TL;DR: Ability to express uncoupling protein (UCP) and establish UCP-dependent thermogenesis was analyzed in anatomical areas of mice and described changes showed that besides typical brown and white adipose tissue in mice, there existed a third type of adipOSE tissue described as convertible adiposes tissue.
Abstract: Ability to express uncoupling protein (UCP) and establish UCP-dependent thermogenesis was analyzed in anatomical areas of mice that are generally considered to be white adipose tissue: mesenterial, perimetral, epididymal, inguinal, and superficial layer of interscapular white adipose tissue. The mice were acclimatized for 1 week to 4° C; the following week they were exposed to cold stress (1 h at-20° C, 2–3 times daily). In such conditions in inguinal adipose tissue, slot-blot analysis detected significant amount of UCP mRNA and lipoprotein lipase mRNA. Immuno-electron-microscopic localization of UCP showed that developed mitochondria of cold-stressed inguinal adipocytes contained UCP in the same amount as uncoupled (UC)-mitochondria of brown adipocytes. Morphological and morphometrical analysis showed that such inguinal adipose tissue appeared as brown adipose tissue. Since in control mice, inguinal adipose tissue was UCP-negative and tissue appeared as white adipose tissue, the duration of this white-to-brown adipose tissue conversion was analyzed. Mice, cold stressed for 1 week, were rewarmed at 28° C and their inguinal adipose tissue was analyzed in comparison with interscapular brown adipose tissue and epididymal white adipose tissue for another 37 days. During that time inguinal adipocytes ceased expressing UCP mRNA; UC-mitochondria in inguinal adipocytes were destroyed and replaced with common, C-mitochondria; and UCP was undetectable immunohistochemically. Adipocytes accumulated lipids, and the tissue morphologically once again resembled white adipose tissue. Described changes showed that besides typical brown and white adipose tissue in mice, there existed a third type of adipose tissue described as convertible adipose tissue.

Journal ArticleDOI
Nils Ryman1
TL;DR: It is argued that assessments of acceptable levels of introgression should be made on the basis of spontaneously occurring gene flow estimated from genetic data using parameters such as Fst or similar ones, and it is concluded that although the fitness approach may appear attractive it is not compatible with the more general objective of maintaining genetic diversity between and within populations.
Abstract: This paper discusses three aspects of genetic conservation relating to fishery management and fish culture, namely (1) the goal for conservation (what to conserve), (2) a guideline for assessing acceptable levels of gene flow among populations. and (3) the effect on the genetically effective population size resulting from stock enhancement. Goal for conservation: The goal for genetic conservation is to maintain genetic variability between and within populations. It has been suggested recently, as an alternative to that goal, that in the context of fisheries management conservation should strive at maintaining the variance or the distribution of fitness. The characteristics of this model are discussed from the perspective of population genetics. It is concluded that although the fitness approach may appear attractive it is not compatible with the more general objective of maintaining genetic diversity between and within populations. Acceptable levels of gene, flow: A tension exists between the need for protection of natural fish populations and the rapidly expanding levels of aquaculture causing increased migration into those populations. Guidelines are needed for assessing levels of introgression that are acceptable in the context of genetic conservation. To avoid unrealistically restrictive recommendations it is suggested that acceptable levels of introgression are related to those occurring naturally. It is argued that assessments of acceptable levels of introgression should be made on the basis of spontaneously occurring gene flow estimated from genetic data using parameters such as Fst or similar ones. Stock enhancement and effective size: In the context of genetic conservation previously published recommendations on stocking have focussed on the need to identify the genetic structure within the region in question to ensure that the appropriate population is targeted for propagation and release. There is, however, an additional aspect that appears to have been largely unrecognized: the reduction of the genetically effective size of the total population that may result from breeding-release programmes aimed at supporting wild stocks. The details of this problem are introduced and discussed.

Posted Content
TL;DR: The authors argue that to understand growth differences across countries and time, one needs to understand differences in public policies that affect the incentives for productive accumulation of capital, human capital, or technically useful knowledge.
Abstract: We start by arguing that to understand growth differences across countries and time, one needs to understand differences in public policies that affect the incentives for productive accumulation of capital, human capital, or technically useful knowledge. And to understand policy differences one needs to understand how political institutions aggregate conflicting interests into public policies. We then survey some recent work along these lines, which argues that more inequality leads to slower growth. Next, we illustrate some of the basic ideas of this work, by help of a simple model of taxation. We also present some econometric cross-country evidence, which is largely supportive of the basic ideas. We end by suggestions for further work.

Journal ArticleDOI
TL;DR: A large part of the class differences in physical as well as mental illness can be understood as a result of systematic differences between classes in living conditions, primarily differences in working conditions.

Journal ArticleDOI
TL;DR: When Cd2+ was applied through the culture medium the capacity for, and the maximal quantum yield of CO2 assimilation by intact plants both decreased, which was associated with decreased total as well as effective chlorophyll content (PSII antennae size), and perturbed carbon reduction cycle as indicated by fluorescence measurements.
Abstract: Sugar-beet plants (Beta vulgaris L. cv. Monohill) were cultivated for 4 weeks in a complete nutrient solution. Indirect effects of cadmium were studied by adding 5, 10 or 20 μM CdCl2 to the culture medium while direct effects were determined by adding 1, 5, 20, 50 or 2 000 μM CdCl2 to the assay media. The photosynthetic properties were characterized by measurement of CO2 fixation in intact plants, fluorescence emission by intact leaves and isolated chloroplasts, photosystem (PS) I and PSII mediated electron transport of isolated chloroplasts, and CO2-dependent O2 evolution by protoplasts. When directly applied to isolated leaves, protoplasts and chloroplasts. Cd2+ impeded CO2 fixation without affecting the rates of electron transport of PSI or PSII or the rate of dark respiration. When Cd2+ was applied through the culture medium the capacity for, and the maximal quantum yield of CO2 assimilation by intact plants both decreased. This was associated with: (1) decreased total as well as effective chlorophyll content (PSII antennae size), (2) decreased coupling of electron transport in isolated chloroplasts, (3) perturbed carbon reduction cycle as indicated by fluorescence measurements. Also, protoplasts isolated from leaves of Cd2+-cultivated plants showed an increased rate of dark respiration.

Journal ArticleDOI
TL;DR: The RPE method functioned well as a means of monitoring and regulating exercise intensity and showed high internal consistency for both velocity and HR between the first two trials at RPE 11.
Abstract: The aims of the present study were a) to compare the outcome of running exercise performed on a treadmill (laboratory) and an outdoor track (field) using an RPE production protocol and b) to study this kind of protocol used over time (3-5 wk). A group of 11 healthy male subjects participated, with ages varying from 33 to 65 yr (mean = 42.9 +/- 11.0 yr). Two test sessions consisting of both treadmill and track exercise were performed in a rotated order to control for sequential effects. All subjects exercised according to an identical protocol: two successive trials (3 min each) at RPE 11 (light exertion), followed by a RPE 13 (somewhat hard) trial (11 min) and, finally, a RPE 15 (hard) trial (5 min). Results show significantly different levels of heart rate (HR), blood lactate, and velocity at the three RPE levels. Large differences were also observed in all measured variables between field and laboratory. These differences were consistent over time. A high internal consistency, measured by test-retest reliability (alpha greater than 0.9), was obtained for both velocity and HR between the first two trials at RPE 11. In conclusion, the RPE method functioned well as a means of monitoring and regulating exercise intensity.

Journal ArticleDOI
TL;DR: The chimeric peptide M-15 [GAL-(1-13)-substance P-(5-11)amide] represents the first antagonist to the neuronal actions of GAL.
Abstract: The 20-amino acid peptide M-15 binds with high affinity (IC50 approximately 0.1 nM) to 125I-labeled galanin (125I-GAL) binding sites in membranes from the ventral hippocampus, midbrain, and rat spinal cord. Receptor autoradiographic studies show that M-15 can displace 125I-GAL from all labeled sites. M-15 acts as a reversible high-affinity antagonist in blocking the inhibitory effects of GAL on the evoked release of acetylcholine in vivo in the hippocampus and on the GAL-induced hyperpolarization of locus coeruleus neurons in slices. M-15 also blocks the facilitatory effects of GAL on the spinal flexor reflex. Thus, the chimeric peptide M-15 [GAL-(1-13)-substance P-(5-11)amide] represents the first antagonist to the neuronal actions of GAL.

Journal ArticleDOI
TL;DR: In this paper, a 1.5 m thick sediment sequence from Midge Lake, Byers Peninsula, Livingston Island, shows that the lake and its catchment have undergone significant changes during the last 4000 years.
Abstract: Analysis of a 1.5 m thick sediment sequence from Midge Lake, Byers Peninsula, Livingston Island, shows that the lake and its catchment have undergone significant changes during the last 4000 years. Radiocarbon dating (AMS), sediment lithology, and microfossil analyses indicate that the lake was deglaciated over 4000 14C years ago. Distinct peaks in accumulation rates of sediment, Pediastrum algae, pollen and spores, as well as changes in the diatom assemblage, suggest significant environmental changes between ca 3200 and 2700 y BP. These changes are interpreted as reflecting a milder and more humid, maritime climate. The increased humidity can explain independent observations of glacier growth during this period. The combined data also indicate that between ca 1500 and 500 y BP the area might have experienced more continental conditions with slightly colder and drier climate than today. Since the 14C dates from the Midge Lake sediments are regarded as reliable and the sediment sequence is rich in tephra layers this sediment sequence will be critical for a forthcoming tephra chronology of the region.

Journal ArticleDOI
TL;DR: Associations among female sperm whales, Physeter macrocephalus, and their dependent offspring, off the Galapagos Islands were studied between 1985 and 1989, although the rate and duration of these associations seemed to vary between years, perhaps because of differences in the food supply.
Abstract: Associations among female sperm whales, Physeter macrocephalus, and their dependent offspring, off the Galapagos Islands were studied between 1985 and 1989. The whales were found in groups containing about 23 individuals, with each individual having approximately 12 constant (over years) companions. These permanent units associated with one another for periods of ≅6.5 days, although the rate and duration of these associations seemed to vary between years, perhaps because of differences in the food supply. The principal function of the closed units may be care of the offspring, and units in the same general area may derive benefit from feeding in a coordinated manner.