Do female pied flycatchers seek extrapair copulations with familiar males? A test of the incomplete knowledge hypothesis

In birds with biparental care, great variation exists in thefrequency of extrapair paternity. Several hypotheses have beenproposed to account for this variation. We tested the incompleteknowledge hypothesis, which states that females are constrainedin their knowledge of male quality and that this influencestheir willingness to engage in extrapair copulations (EPC).By selective removal and release of female pied flycatchersFicedula hypoleuca, we created a situation where females finallysettled with a social mate close to the site where a formersocial mate was breeding. According to the incomplete knowledgehypothesis, this would lower the threshold for females to seekextrapair copulations in cases where their former social matewas of higher quality than the one finally chosen. The hypothesiswas not supported because manipulation of female settlementdid not increase frequency of extrapair paternity, not evenin cases where the female nested close to the previous mateand the current mate apparently was of lower quality becausehe was younger and more dull colored. However, we found that when extrapair paternity did occur, the cuckolder tended tobe a familiar male (i.e., the female's initial social mate).     

The likelihood of persistent arthritis increases with the level of anti-citrullinated peptide antibody and immunoglobulin M rheumatoid factor: a longitudinal study of 376 patients with very early undifferentiated arthritis

Introduction  

We wanted to assess the importance of the levels of anti-citrullinated peptide antibody (anti-CCP) and immunoglobulin M (IgM) rheumatoid factor (RF) in predicting development of persistent arthritis from undifferentiated arthritis (UA), and to investigate whether there is an added predictive value for persistent arthritis in testing for both anti-CCP and IgM RF.     

Coexistent Coccidioidomycosis of the Meninges and Pulmonary Cavitation Due to Coccidioides

A clinical study was undertaken to evaluate the effectiveness of concentrated cabbage juice in the treatment of peptic ulcers. Patients at San Quentin Prison with a diagnosed ulcer crater were treated in a double blind control experiment. They were given either concentrated cabbage juice or placebo facsimile. The evaluation of the merit of this treatment was based upon repeated x-ray examinations of the ulcer crater. A period of 22 days was allowed for ulcer crater healing time.The results of this experiment indicated concentrated cabbage juice to be effective in healing of peptic ulcer.     

Temporal and regional variation in the copepod community in the central Barents Sea during spring and early summer 1988 and 1989

In this study, we examined a 3000 km² area to the southeastof Bear Island in the central Barents Sea with respect to copepodabundance and depth distribution at nine stations in March,April and May of 1988 and 1989. In order to describe the populationdynamics of the most prominent species in the area during theperiod of study, the annual ascent and abundance of Calanusfinmarchicus, Metridia longa and Calanus glacialis are shown.Stage abundance, vertical distribution and cohort developmentdid vary between species and years at one site. The number ofspecies and the complexity of the data for the entire area studiedhave encouraged us to search for more significant and persistentpatterns by using a canonical correlation analysis (CCA). Weincluded a total of 27 species and stage categories, latitude,salinity and sigma from the nine stations in 1989 We performedthis analysis for 1989. since we only have environmental data(CTD) available from the same stations in that year The species-environmentrelationship showed that the zooplankton community could notbe grouped according to area (latitude) or environmental (sigma,salinity) conditions during March–May in 1989. This meansthat the differences in environmental conditions in the areaof study in 1989 do not mediate any consistent gradient in thezooplankton community. When comparing the copepod data for bothyears. the largest differences are associated with the depthand month vectors. The largest interannual variation is seenin the copepod community in the depth strata from 100 to 400m. and is related to a lesser degree of similarity among thespecies and stages found in this depth interval throughout thestudy. Two species were particularly responsible for the interannualdifferences: Pseudocalanus acuspes CV and females, and C glacialisCV and adults. Changes in these two species are clearly relatedto major shifts in the hydrographic conditions between the 2years, where 1988 was generally colder compared to 1989.     

A taxonomic reappraisal of the European Daphnia longispina complex (Crustacea, Cladocera, Anomopoda)

The Daphnia longispina complex contains some of the most common water flea species in the northern hemisphere, and has been a model organism for many ecological and evolutionary studies. Nevertheless, the systematics and nomenclature of this group, in particular its Palaearctic members, have been in flux for the past 150 years; this hinders the correct interpretation of scientific results and promotes the erroneous use of species names. We revise the systematics of this species complex based on mitochondrial sequence variation (12S rDNA and COI) of representative populations across Europe, with a special focus on samples from type localities of the respective taxa. Combining genetic evidence and morphological assignments of analysed individuals, we propose a comprehensive revision of the European members of the D. longispina complex. We show that D. hyalina and D. rosea morphotypes have evolved several times independently, and we find no evidence to maintain these morphotypes as distinct biological species. Alpine individuals described as D. zschokkei are conspecific with the above-mentioned lineage. We suggest that this morphologically and ecologically plastic but genetically uniform hyalina–rosea–zschokkei clade should be identified as D. longispina (O. F. Müller, 1776). The valid name of Fennoscandian individuals labelled D. longispina sensu stricto in the recent literature is D. lacustris G. O. Sars, 1862. Additionally, we discovered another divergent lineage of this group, likely an undescribed species, in southern Norway. Our results present a solution for several prevailing taxonomic problems in the genus Daphnia , and have broad implications for interpretation of biogeographical patterns, and ecological and evolutionary studies.     

Sympatric population divergence within a highly pelagic seabird species complex (Hydrobates spp.)

Both physical and non‐physical barriers can restrict gene flow among seabird populations. Understanding the relative importance of non‐physical barriers, such as breeding phenology, is key to understanding seabird biodiversity. We investigated drivers of diversification in the Leach's storm‐petrel species complex (Hydrobates spp.) by examining population genetic structure across its range. Variation in the mitochondrial control region and six microsatellite loci was assayed in birds sampled from breeding colonies throughout the North Atlantic and North Pacific (H. leucorhoa leucorhoa), as well as from San Benito Islands (H. l. chapmani), and two seasonal populations in Guadalupe (summer breeding H. socorroensis and winter breeding H. cheimomnestes), Mexico. Weak but significant differentiation was found between populations of H. l. leucorhoa breeding in the Atlantic versus North Pacific, as well as between H. l. chapmani and H. l. leucorhoa, and between H. socorroensis and H. cheimomnestes within Guadalupe. In contrast, strong differentiation in both mitochondrial DNA and microsatellites was found between H. leucorhoa and both H. socorroensis and H. cheimomnestes. Phylogenetic reconstruction suggested the Guadalupe seasonal breeding populations are sister taxa, at least in their mitochondrial DNA. Non‐physical barriers to gene flow appear to be more important than physical barriers in driving divergence within the Leach's storm‐petrel species complex. In particular, allochronic speciation may have occurred between the seasonal populations within Guadalupe. Further work should include higher resolution sequencing to confirm results, and an increased sampling effort, particularly within the California area, to fully resolve the relationship between H. l. leucorhoa and H. l. chapmani.     

Cloning and characterization of rac-like cDNAs from Arabidopsis thaliana

The Rho family of GTPases are in higher eukaryotes divided into 3 major subfamilies; the Rho, Rac and Cdc42 proteins. In plants, however, the Rho family is restricted to one large family of Rac-like proteins. From work with mammalian phagocytes the Rac proteins are known to activate a multicomponent NADPH-dependent oxidase which results in accumulation of H₂O₂, a process termed oxidative burst. In plants a similar oxidative burst is observed and plays an important role in its defence against pathogen infections, suggesting a similar role for the plant Rac-like proteins. The Rho family of GTPases proteins are also involved in control of cell morphology, and are also thought to mediate signals from cell membrane receptors.In a broad search for members of the Ras superfamily in plants, several new small GTP-binding proteins were found. We report here the identification and molecular cloning of 5 rac-like cDNAs from Arabidopsis thaliana, Arac1–5. The Rac-like proteins deduced from the cDNA sequences all share 80–95% homology, but show considerably more diversity on the nucleotide level, indicating that this is an ancient gene family. Four of the rac genes were found to be expressed in all tissues examined, but one gene, Arac2, was expressed exclusively in the root, hypocotyl and stem. Our results show that the rac gene family in A. thaliana consists of at least 10 different genes.