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Alternative mating strategies are common in nature and are generally thought to increase the intensity of sexual selection. However, cuckoldry can theoretically decrease the opportunity for sexual selection, particularly in highly polygamous species. We address here the influence of sneaking (fertilization thievery) on the opportunity for sexual selection in the sand goby Pomatoschistus minutus, a marine fish species in which males build and defend nests. Our microsatellite-based analysis of the mating system in a natural sand goby population shows high rates of sneaking and multiple mating by males. Sneaker males had fertilized eggs in approximately 50% of the assayed nests, and multiple sneakers sometimes fertilized eggs from a single female. Successful males had received eggs from 2 to 6 females per nest (mean = 3.4). We developed a simple mathematical model showing that sneaking in this polygynous sand goby population almost certainly decreases the opportunity for sexual selection, an outcome that contrasts with the usual effects of cuckoldry in socially monogamous animals. These results highlight a more complex and interesting relationship between cuckoldry rates and the intensity of sexual selection than previously assumed in much of the literature on animal mating systems.

Molecular markers have proved extremely useful in resolving mating patterns within individual populations of a number of species, but little is known about how genetic mating systems might vary geographically within a species. Here we use microsatellite markers to compare patterns of sneaked fertilization and mating success in two populations of sand goby (Pomatoschistus minutus) that differ dramatically with respect to nest-site density and the documented nature and intensity of sexual selection. At the Tvärminne site in the Baltic Sea, the microsatellite genotypes of 17 nest-tending males and mean samples of more than 50 progeny per nest indicated that approximately 35% of the nests contained eggs that had been fertilized by sneaker males. Successful nest holders mated with an average of 3.0 females, and the distribution of mate numbers for these males did not differ significantly from the Poisson expectation. These genetically deduced mating-system parameters in the Tvärminne population are remarkably similar to those in sand gobies at a distant site adjoining the North Sea. Thus, pronounced differences in the ecological setting and sexual selection regimes in these two populations have not translated into evident differences in cuckoldry rates or other monitored patterns of male mating success. In this case, the ecological setting appears not to be predictive of alternative male mating strategies, a finding of relevance to sexual selection theory.

To improve the nitrogen fixation, legume crops are often inoculated with selected effective rhizobia. However, there is large variation in how well the inoculant strains compete with the indigenous microflora in soil. To assess the success of the inoculant, it is necessary to distinguish it from other, closely related strains. Methods used until now have generally been based either on fingerprinting methods or on the use of reporter genes. Nevertheless, these methods have their shortcomings, either because they do not provide sufficiently specific information on the identity of the inoculant strain, or because they use genetically modified organisms that need prior authorization to be applied in the field or other uncontained environments. Another possibility is to target a gene that is naturally present in the bacterial genomes. Here we have developed a method that is based on amplicon sequencing of the bacterial housekeeping gene rpoB, encoding the beta‐subunit of the RNA polymerase, which has been proposed as an alternative to the 16S rRNA gene to study the diversity of rhizobial populations in soils. We evaluated the method under laboratory and field conditions. Peanut seeds were inoculated with various Bradyrhizobium strains. After nodule development, DNA was extracted from selected nodules and the nodulating rhizobia were analysed by amplicon sequencing of the rpoB gene. The analyses of the sequence data showed that the method reliably identified bradyrhizobial strains in nodules, at least at the species level, and could be used to assess the competitiveness of the inoculant compared to other bradyrhizobia. [ABSTRACT FROM AUTHOR]

Background: Managing modern diabetes treatment requires efficient executive functions. Patients with attention‐deficit/hyperactivity disorder (ADHD) and type 1 diabetes have poor metabolic control and present with ketoacidosis more often than patients without ADHD. Objective: To assess whether patients with type 1 diabetes and with indications of executive problems met criteria for ADHD, and to investigate whether these patients had difficulties achieving metabolic control. Methods: In a hospital‐based study, including 3 pediatric departments at hospitals in Stockholm and Uppsala, Sweden, questionnaires regarding executive problems had been filled out by 12‐ to 18‐year‐old patients with type 1 diabetes and their parents. Out of 166 patients with completed questionnaires, 49 were selected for a clinical study due to reported executive problems/ADHD symptoms. However, 7 already had a diagnosis of ADHD, 21 denied follow‐up, 8 did not respond, leaving 13 adolescents for the clinical assessment. Results: Of the clinically assessed adolescents, 9 (6 girls) met criteria for ADHD. Patients who did not respond to the follow‐up and patients who were diagnosed with ADHD within the study, showed to a larger extent than the other study groups high HbA1c levels (>70 mmol/mol, 8,6%). HbA1c >70 mmol/mol (8.6%) was associated with diagnosed ADHD (prior to or within the study), odds ratio 2.96 (95% confidence interval 1.02‐8.60). Conclusion: Patients with type 1 diabetes and poor metabolic control should be assessed with regard to ADHD. There is a need for paying special attention to girls with poor metabolic control. [ABSTRACT FROM AUTHOR]

The eyes of two glacial-relict populations of opossum shrimp Mysis relicta inhabiting the different photic environments of a deep, darkbrown freshwater lake and a variably lit bay of the Baltic Sea differ in their susceptibility to functional depression from strong light exposures. The lake population is much more vulnerable than the sea population. We hypothesized that the difference reflects physiological adaptation mechanisms operating on long time scales rather than genetically fixed differences between the populations. To test this, we studied how acclimation to ultra-slowly increased illumination (on time scales of several weeks to months) affected the resilience of the eyes to bright-light exposures. Light responses of whole eyes were measured by electroretinography, the visualpigment content of single rhabdoms by microspectrophotometry and the structural integrity of photoreceptor cells by electron microscopy (EM). Slow acclimation mitigated and even abolished the depression of photoresponsiveness caused by strong light exposures, making a dramatic difference especially in the lake animals. Still, acclimation in the sea animals was faster and the EM studies suggested intrinsic differences in the dynamics of microvillar membrane cycling. In conclusion, we report a novel form of physiological adaptation to general light levels, effective on the time scale of seasonal changes. It explains part but not all of the differences in light tolerance between the lake and sea populations. [ABSTRACT FROM AUTHOR]

Ways to measure blood perfusion using ultrasound techniques such as continuous-wave Doppler, pulsed Doppler, colour Doppler and power Doppler will be reviewed. From a certain standpoint, blood perfusion may be defined as the difference between arterial inflow and arterial outflow from a considered volume, i.e. capillary flow. The low velocities and small blood volumes involved make the signal-to-noise ratio, dynamic range and frequency resolution critical factors in the detection system. Another limiting factor is tissue motion which obscures the blood signal. Perfusion may still under certain conditions be estimated with the first moment of the Doppler power spectrum, as obtained with any Doppler ultrasound method. Modern flow mapping techniques also make it possible to estimate perfusion by counting the number of pixels that indicate flow, but low flow velocities cannot be included in the estimate. Future high-frequency systems may, however, provide very detailed images of minute flow distributions in superficial layers. Contrast agents are widely used today to enhance the blood signal, and a technique named harmonic imaging can suppress movement artefacts from surrounding tissue. Transient signals from disrupting contrast agent particles in an ultrasound field can potentially be used for perfusion quantification. Future developments to extract the blood flow signal from its noisy environment, aside from contrast agents, may be multiple sample volumes, frequency compounding and/or improved signal processing. The lack of an adequate perfusion phantom for verification of measurements of microcirculatory flow becomes, however, more apparent with improved detectability of slow flows. [ABSTRACT FROM AUTHOR]

Legume plants can obtain combined nitrogen for their growth in an efficient way through symbiosis with specific bacteria. The symbiosis between Rhizobium galegae and its host plant Galega is an interesting case where the plant species G. orientalis and G. officinalis form effective, nitrogen-fixing, symbioses only with the appropriate rhizobial counterpart, R. galegae bv. orientalis and R. galegae bv. officinalis, respectively. The symbiotic properties of nitrogen-fixing rhizobia are well studied, but more information is needed on the properties of the host plants. The Caucasus region in Eurasia has been identified as the gene centre (centre of origin) of G. orientalis, although both G. orientalis and G. officinalis can be found in this region. In this study, the diversity of these two Galega species in Caucasus was investigated to test the hypothesis that in this region G. orientalis is more diverse than G. officinalis. The amplified fragment length polymorphism fingerprinting performed here showed that the populations of G. orientalis and R. galegae bv. orientalis are more diverse than those of G. officinalis and R. galegae bv. officinalis, respectively. These results support the centre of origin status of Caucasus for G. orientalis at a genetic level. Analysis of the symbiosis-related plant genes NORK and Nfr5 reveals remarkable diversity within the Nfr5 sequence, although no evidence of adaptive evolution could be found. [ABSTRACT FROM AUTHOR]

According to life-history theory, a care-taking parent should balance investment in current and future reproduction in such a way that it maximizes lifetime reproductive success. In the sand goby Pomatoschistus minutus, a small marine fish with paternal care, nest-guarding males may lose current reproductive success to both parasitically fertilizing males and egg predators. Here, we observed sand gobies at a marine and a brackish site, two geographically distant and ecologically different habitats. In a field experiment, we found that sand gobies at the marine site suffered from severe egg predation by netted dogwhelks Nassarius nitidus, which are lacking at the brackish site. Because egg laying takes hours and several females often lay eggs sequentially in one nest, the risk of parasitic spawnings and egg predation overlaps in time during breeding activities. Hypothesizing that egg predators might influence the success of parasitic spawnings, we then simulated these natural conditions in a laboratory experiment with the presence or absence of egg predators, combined with the presence of sneaker males. As expected, in the egg predator treatment, egg-guarding males had to compromise between defence behaviours and thus had less time to devote to defence against sneaker males. Sneaker males took advantage of the situation and approached the nests more actively than in the predator-free treatment. However, the increase in approaches did not result in more successful parasitic fertilizations by sneaker males, as determined using microsatellite DNA. Nevertheless, in nature the adjustment of time budgets by the egg-guarding male are likely to have serious fitness consequences, both if the male fails to defend his paternity and if he fails to defend his offspring. [ABSTRACT FROM AUTHOR]

Cites findings of a study conducted to examine the annual variation in gobiid larval density in the northern Baltic Sea. Impact of water temperature on the density of larvae within breeding seasons; Correlation between the spawning stock size and the gobiid production; Reasons for the high representation of the gobiids in the Baltic sea than in the North sea.

Nest site use by the common goby, Pomatoschistus microps was investigated in the Malagroy lagoon (France, Camargue) during a complete breeding season. Male common gobies seemed to select their nests in relation to their size, as a positive relationship between male total length and nest area was found. No significant relationship was found between the number of eggs in a nest and the size of nesting male, suggesting that female common goby did not show a preference for larger males. Nests containing two distinct eggs clutches were observed for the first time. The percentage of double clutched nests was relatively high in June-July, when only young-of-the-year common gobies were observed to reproduce. Large nesting males reproduced first in the season (in February- March), but they were not observed to reproduce again in July. Instead they were replaced by small males born early in spring. [ABSTRACT FROM PUBLISHER]

Sand goby males guarding eggs from one female without access to food lost 13.9% of their body weight over a caring period of 10 days. This was more than twice the body weight lost by non-guarding males, who had nests but no eggs (weight loss 5.8%). Caring for the eggs therefore imposes an energetic cost on the male. Egg losses in the field were on average 3.3% of the egg mass. Males with egg losses were on average smaller than males without losses and they also had smaller egg masses. If a male was removed and his nest taken by a new male, 31.0 to 100.0% of the original eggs were eaten within 24 hr. In guarding males we never observed hetero-cannibalism. The proportion of time a male spent fanning was positively correlated to his standard length, larger males spending more time fanning. It is concluded that larger males are better fathers. [ABSTRACT FROM PUBLISHER]

The aromatic content of the high molecular matter in pulp mill bleachery effluents has been characterized after chemical degradation in the laboratory followed by derivatization and gas chromatographic/mass spectrometric analysis. Aromatic molecules with carboxy, hydroxy, methoxy and chloro substituents were separated and identified by recording their computer-reconstructed ion current chromatograms. About 70 aromatic carboxylic acids were tentatively identified as degradation products. Aromatic compounds with hydroxy groups were derivatized to trideuteromethoxy groups in order to distinguish them by mass spectrometry from compounds with naturally occurring methoxy groups. Single and double hydrogen atom transfer between methyl ester and methoxy groups were observed in some molecules and given special attention when they occurred ortho to each other. A methoxy group substituted ortho to a methyl carboxylate resulted in an unusual fragmentation. [ABSTRACT FROM AUTHOR]

The competitiveness of four Rhizobium sp. strains infecting Acacia senegal and originating in the Sudan was assessed in a growth chamber experiment using Sudanese soil, When Acacia senegal was inoculated with pure cultures of the strains, there were statistically significant differences among the strains with respect to the numbers of nodules formed, the amount of dry matter produced and acetylene reduction activity. However, the best strain when applied as a pure culture, was only the second best as a competitor. Two strains with inferior symbiotic capabilities were also bad competitors but nevertheless reduced the yields of the plants when they were applied as inocula mixed with the better strains. The bacterial markers used to assess nodule occupancy were resistance to streptomycin or spectinomycin. Two of the strains formed the dark-brown pigment melanin. Melanin production was a stable characeristic, well suited to serve as an intrinsic identification marker when assessing the competitiveness of melanin-producing versus non-producing strains in controlled conditions. [ABSTRACT FROM AUTHOR]

Formica cinerea is a rare ant species in northern Europe where it occurs in few isolated populations. Estimates of genetic relatedness among worker nestmates revealed very different colonial structures. Relatedness was g = 0.81 in one population, and g = −0.03 and = 0.01 in two others. These results indicate that some populations of the species have mainly monogynous colonies (perhaps with monandrous queens), whereas others consist of polygynous and possibly polydomous colonies. Genetic differentiation of closely located populations suggests restricted dispersal. [ABSTRACT FROM AUTHOR]