63 research outputs found

    Local starburst galaxies and their descendants

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    Despite strong interest in the starburst (hereafter SB) phenomenon, the concept remains ill-defined. We use a strict definition of SB to examine the statistical properties of local SB and post-starburst (hereafter PB) galaxies. We also seek relationships to active galaxies. Potential SB galaxies are selected from the SDSS DR7 and their stellar content is analysed. We apply an age dependent dust attenuation correction and derive star formation rates (SFR), ages and masses of the young and old populations. The photometric masses nicely agree with dynamical masses derived from the H-alpha emission line width. To select SB galaxies, we use the birthrate parameter b=SFR/, requiring b>=3. The PB sample is selected from the citerion EW(Hdelta_abs)>=6 A. Only 1% of star-forming galaxies are found to be SB galaxies. They contribute 3-6% to the stellar production and are therefore unimportant for the local star formation activity. The median SB age is 70 Myr, roughly independent of mass. The b-parameter strongly depends on burst age. Values close to b=60 are found at ages ~10 Myr, while almost no SBs are found at ages >1 Gyr. The median baryonic burst mass fraction of sub-L* galaxies is 5%, decreasing slowly with mass. The median mass fraction of the recent burst in the PB sample is 5-10%. The age-mass distribution of the progenitors of the PBs is bimodal with a break at log(M)~10.6 above which the ages are doubled. The SB and PB luminosity functions (hereafter LFs) follow each other closely until M_r~-21, when AGNs begin to dominate. The PB LF continues to follow the AGN LF while SB loose significance. This suggests that the number of luminous SBs is underestimated by about one dex at high luminosities, due to large amounts of dust and/or AGN blending. It also indicates that the SB phase preceded the AGN phase. We also discuss the conditions for global gas outflow caused by stellar feedback.Comment: Accepted for publication in Astronomy and Astrophysics. This is an extended, substantially revised and corrected version with partly modified conclusion

    Genomic Diversity and Runs of Homozygosity in Bernese Mountain Dogs

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    Bernese mountain dogs are a large dog breed formed in the early 1900s in Switzerland. While originally farm dogs that were used for pulling carts, guarding, and driving cattle, today they are considered multi-purpose companion and family dogs. The breed is predisposed to several complex diseases, such as histiocytic sarcoma, degenerative myelopathy, or hip dysplasia. Using whole-genome sequencing (WGS) data, we assessed the genomic architecture of 33 unrelated dogs from four countries: France, Sweden, Switzerland, and the United States. Analysis of runs of homozygosity (ROH) identified 12,643 ROH with an average length of 2.29 Mb and an average inbreeding coefficient of 0.395. Multidimensional scaling analysis of the genetic relatedness revealed limited clustering of European versus USA dogs, suggesting exchanges of breeding stock between continents. Furthermore, only two mtDNA haplotypes were detected in the 33 studied dogs, both of which are widespread throughout multiple dog breeds. WGS-based ROH analyses revealed several fixed or nearly fixed regions harboring discreet morphological trait-associated as well as disease-associated genetic variants. Several genes involved in the regulation of immune cells were found in the ROH shared by all dogs, which is notable in the context of the breed's strong predisposition to hematopoietic cancers. High levels of inbreeding and relatedness, strongly exaggerated in the last 30 years, have likely led to the high prevalence of specific genetic disorders in this breed

    An investigation on the presence of Chlamydiaceae in Swedish dogs

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    <p>Abstract</p> <p>Background</p> <p>Bacteria belonging to the family <it>Chlamydiaceae </it>cause a broad spectrum of diseases in a wide range of hosts, including man, other mammals, and birds. Upper respiratory and genital diseases are common clinical problems caused by <it>Chlamydiaceae</it>. Very little is known about chlamydial infections in dogs. Few clinical reports on natural disease in dogs describe mainly conjunctival and upper respiratory signs, and the role of <it>Chlamydiaceae </it>in genital disease is unclear. The present study aimed at studying the prevalence of <it>Chlamydiaceae </it>in healthy dogs and in dogs with genital or upper respiratory disease, including conjunctivitis.</p> <p>Methods</p> <p>A real-time polymerase chain reaction (PCR) for <it>Chlamydiaceae </it>was used to detect any chlamydial species within this family. Swab samples from the conjunctiva and the mucosal membranes of the oropharynx, rectum and genital tract were taken from 79 dogs: 27 clinically healthy dogs, 25 dogs with clinical signs from the genital tract and 28 dogs with conjunctivitis. There were 52 female and 27 male dogs. From 7 of the male dogs, additional semen samples were analysed.</p> <p>Results</p> <p>No <it>Chlamydiaceae </it>were detected from any dog.</p> <p>Conclusions</p> <p>Although the number of dogs that was included is limited, the results suggest that cases of <it>Chlamydiaceae </it>in dogs probably are related to infection from other species, and that dogs in general do not harbour <it>Chlamydiaceae</it>. Bacteria belonging to the family <it>Chlamydiaceae </it>do not seem to be of major importance for genital or ocular disease in Swedish dogs.</p

    Brucellosis Vaccines: Assessment of Brucella melitensis Lipopolysaccharide Rough Mutants Defective in Core and O-Polysaccharide Synthesis and Export

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    Background: The brucellae are facultative intracellular bacteria that cause brucellosis, one of the major neglected zoonoses. In endemic areas, vaccination is the only effective way to control this disease. Brucella melitensis Rev 1 is a vaccine effective against the brucellosis of sheep and goat caused by B. melitensis, the commonest source of human infection. However, Rev 1 carries a smooth lipopolysaccharide with an O-polysaccharide that elicits antibodies interfering in serodiagnosis, a major problem in eradication campaigns. Because of this, rough Brucella mutants lacking the O-polysaccharide have been proposed as vaccines. Methodology/Principal Findings: To examine the possibilities of rough vaccines, we screened B. melitensis for lipopolysaccharide genes and obtained mutants representing all main rough phenotypes with regard to core oligosaccharide and O-polysaccharide synthesis and export. Using the mouse model, mutants were classified into four attenuation patterns according to their multiplication and persistence in spleens at different doses. In macrophages, mutants belonging to three of these attenuation patterns reached the Brucella characteristic intracellular niche and multiplied intracellularly, suggesting that they could be suitable vaccine candidates. Virulence patterns, intracellular behavior and lipopolysaccharide defects roughly correlated with the degree of protection afforded by the mutants upon intraperitoneal vaccination of mice. However, when vaccination was applied by the subcutaneous route, only two mutants matched the protection obtained with Rev 1 albeit at doses one thousand fold higher than this reference vaccine. These mutants, which were blocked in O-polysaccharide export and accumulated internal O-polysaccharides, stimulated weak anti-smooth lipopolysaccharide antibodies. Conclusions/Significance: The results demonstrate that no rough mutant is equal to Rev 1 in laboratory models and question the notion that rough vaccines are suitable for the control of brucellosis in endemic areas.This work was funded by the European Commission (Research Contract QLK2-CT-2002-00918) and the Ministerio de Ciencia y Tecnología of Spain (Proyecto AGL2004-01162/GAN)

    Meta-analysis identifies seven susceptibility loci involved in the atopic March

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    Eczema often precedes the development of asthma in a disease course called the a 'atopic march'. To unravel the genes underlying this characteristic pattern of allergic disease, we conduct a multi-stage genome-wide association study on infantile eczema followed by childhood asthma in 12 populations including 2,428 cases and 17,034 controls. Here we report two novel loci specific for the combined eczema plus asthma phenotype, which are associated with allergic disease for the first time; rs9357733 located in EFHC1 on chromosome 6p12.3 (OR 1.27; P=2.1 × 10 a'8) and rs993226 between TMTC2 and SLC6A15 on chromosome 12q21.3 (OR 1.58; P=5.3 × 10 a'9). Additional susceptibility loci identified

    Bridging the communicative gap between a person with dementia and caregivers. A nursing perspective

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    The aim was to explore possible areas and sources that could inform the care for people with dementia. These were the people with dementia themselves, nurses reflective discussions about caring, nurse-patient interaction together with information from close family members, and the previous personality and sense of coherence of people with dementia in relation to behaviour during the disease as related by themselves and/or a family member and the experiences of everyday life for people with dementia still able to talk about their experiences and living as a couple when one of the partners has a dementia disease. The results are based on open-ended personal interview data from the person with dementia (n=11) and their spouses (n=6) regarding experiences of having a dementia disease. A number of 111 direct observations of the interaction between nurse and patient (n=22) during morning care and analysis of notes from clinical supervision sessions, personal interviews with a next of kin (n=40) were collected to study the relation between previous personality and reactions during the dementia disease. The agreement between an elderly persons? (n=77) self-assessment of personality (EPI) and sense of coherence (SOC) and that of a next of kin was also studied (n=77). The life of the people with dementia changed during the course of the dementia and in various ways they struggled to preserve a sense of self in relation to themselves and to others and recreated meaning and identity in their lives. Responsibilities were redistributed with the healthy spouse taking over mutual activities. The nurse-patient encounters demonstrated mutuality and acting at the same pace and unilaterality and acting out of pace with each other. In the reflective discussions nurses spoke about either confirming or threatening the nurse's and/or patient's identity and integrity. Patients experienced as vocally disruptive were more often described as introverted, rigid and with a tendency to control emotions prior to the disease as remembered by a next of kin than those not vocally active. The agreement between self-rating scores and the ratings made by a next of kin in measuring personality and sense of coherence was high or moderate. However information given by a spouse about the meaning of having a dementia disease did not fully agree with the sick partners understanding of it. The findings in the thesis may form a basis for the development of models with various kinds of knowledge framing the foundation for care for people with a dementia disease

    Exploring the meaning of everyday life, for those suffering from dementia

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    Living with dementia means struggling to preserve a sense of self, to retain (and reevaluate) one's values in a new situation, and to search for a new way of life. This study explored the meaning of everyday life as expressed by 11 people suffering from dementia. Data were collected through interviews with people in the early stage of a diagnosed dementia disease. The findings indicate that many people with dementia feel shame, sorrow, and sadness when their life with the disease begins but also indicate prospects of a more manageable life. Since the reaction and adjustment to dementia differs from person to person, professional caregivers need to use a case-specific approach in the provision of care

    Wellbeing among people with dementia and their next of kin over a period of 3 years.

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    Scand J Caring Sci; 2011 Wellbeing among people with dementia and their next of kin over a period of 3 years Little is known about the dyadic experience over time of people with dementia and their next of kin. The aim of this study was to investigate the state of mind of people with dementia, their next of kin's experience of burden and satisfaction, and factors associated with these experiences over a 3-year period. The sample consisted of 32 people with dementia living at home with family caregivers in the south of Sweden. Data were collected during the period 2004-2007 and consisted of patients self reports (GDS), dementia nurse assessment (MMSE, Berger and ADL) and next-of-kin assessment (patient's state of mind and care provision). Data also consisted of next-of-kin's self reports concerning health, burden and satisfaction. The result showed that patients' state of mind was mainly positive at baseline but a deterioration was seen over time in the patient's mood and cognitive functioning together with an increase in ADL-dependency and suspected depression. Dependency in personal ADL entailed a higher risk of being in a negative state of mind. For next of kin the experience of burden increased while satisfaction decreased over the 3 years. The inter-relationship between the patients' mood and the caregiver's satisfaction and burden seems to get stronger over time. At baseline caregiver burden was mainly related to the next of kins' general health and to patient behaviours that were difficult to handle. During the progression of the disease caregiver satisfaction becomes increasingly related to patient state of mind and dependency. There is, however, a need for more research focusing on the specific inter-relational aspects as previous studies have mainly focused on either the situation for the person with dementia or on the caregiver
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