Hemispheric asymmetry in ocean change and the productivity of ecosystem sentinels.

Climate change and other human activities are causing profound effects on marine ecosystem productivity. We show that the breeding success of seabirds is tracking hemispheric differences in ocean warming and human impacts, with the strongest effects on fish-eating, surface-foraging species in the north. Hemispheric asymmetry suggests the need for ocean management at hemispheric scales. For the north, tactical, climate-based recovery plans for forage fish resources are needed to recover seabird breeding productivity. In the south, lower-magnitude change in seabird productivity presents opportunities for strategic management approaches such as large marine protected areas to sustain food webs and maintain predator productivity. Global monitoring of seabird productivity enables the detection of ecosystem change in remote regions and contributes to our understanding of marine climate impacts on ecosystems.

Experiences with multiple job holding: a qualitative study among Dutch older workers.

BACKGROUND: Multiple job holding (MJH) is a common and growing phenomenon in many countries. Little is known about experiences with MJH among older workers. The objective of the present study is to gain insight in experiences with MJH among Dutch workers aged 45 years and older. METHODS: Multiple job holders were selected from the Study on Transitions in Employment, Ability, and Motivation (STREAM), a Dutch cohort study among persons aged 45 years and older. Purposive sampling was applied to assure heterogeneity regarding gender, educational level, health, financial situation, willingness to continue MJH, and type of MJH (only jobs as employee or also being self-employed). Interviews were conducted until data saturation occurred. Fifteen multiple job holders participated in this study (eight men, seven women). Interviews were digitally recorded, transcribed verbatim and analyzed, along with field notes, using thematic content analysis. The data were openly coded, after which codes were aggregated into themes, which formed a thematic map. In each phase of the analysis at least two researchers were involved to increase reliability. RESULTS: Experiences with MJH varied from positive to negative. They were influenced by characteristics of individual jobs, e.g. social support at work, as well as characteristics of the combination of jobs, e.g. positive spill-over effects, and conflicts between work schedules. The personal context of multiple job holders, e.g. their age, or reason for MJH, affected how work characteristics influenced experiences. Negative experiences with one job often coincided with negative experience in the other job(s), and problems in the personal context. Some multiple job holders were able to make changes to their situation when desired. For some, this was not possible, which augmented their negative experience. CONCLUSIONS: This study adds to existing knowledge that experiences with MJH are not only influenced by work characteristics but also by the personal context of multiple job holders, and that some workers are able to change their situation when desired, while others are not. Future research should study how different combinations of work and personal characteristics influence sustainable employability of multiple job holders. Policies facilitating life-long learning could increase opportunities to change the MJH situation when desired.

Telomere attrition and growth: a life-history framework and case study in common terns.

The relationship between growth and age-specific telomere length, as a proxy of somatic state, is increasingly investigated, but observed patterns vary and a predictive framework is lacking. We outline expectations based on the assumption that telomere maintenance is costly and argue that individual heterogeneity in resource acquisition is predicted to lead to positive covariance between growth and telomere length. However, canalization of resource allocation to the trait with a larger effect on fitness, rendering that trait relatively invariant, can cause the absence of covariance. In a case study of common tern (Sterna hirundo) chicks, in which hatching order is the main determinant of variation in resource acquisition within broods, we find that body mass, but not telomere length or attrition, varies with hatching order. Moreover, body mass and growth positively predict survival to fledging, whereas telomere length and attrition do not. Using a novel statistical method to quantify standardized variance in plasticity, we estimate between-individual variation in telomere attrition to be only 12% of that of growth. Consistent with the relative invariance of telomere attrition, we find no correlation between age-specific body mass or growth and telomere attrition. We suggest that common tern chicks prioritize investment in long-term somatic state (as indicated by canalization of telomere maintenance) over immediate survival benefits of growth as part of an efficient brood reduction strategy that benefits the parents. As such, interspecific variation in the growth-telomere length relationship may be explained by the extent to which parents benefit from rapid mortality of excess offspring.

Trans-generational effects on ageing in a wild bird population.

Ageing, long thought to be too infrequent to study effectively in natural populations, has recently been shown to be ubiquitous, even in the wild. A major challenge now is to explain variation in the rates of ageing within populations. Here, using 49 years of data from a population of great tits (Parus major), we show that offspring life-history trajectories vary with maternal age. Offspring hatched from older mothers perform better early in life, but suffer from an earlier onset, and stronger rate, of reproductive senescence later in life. Offspring reproductive lifespan is, however, unaffected by maternal age, and the different life-history trajectories result in a similar fitness payoff, measured as lifetime reproductive success. This study therefore identifies maternal age as a new factor underlying variation in rates of ageing, and, given the delayed trans-generational nature of this effect, poses the question as to proximate mechanisms linking age-effects across generations.

Great tits growing old: selective disappearance and the partitioning of senescence to stages within the breeding cycle.

Deterioration of reproductive traits with age is observed in an increasing number of species. Although such deterioration is often attributed to reproductive senescence, a within-individual decline in reproductive success with age, few studies on wild animals have focused on direct fitness measures while accounting for selective disappearance and terminal effects, and to our knowledge none have determined how senescence effects arise from underlying reproductive traits. We show for female great tits that such an approach helps understanding of the onset, impact and architecture of senescence. Cross-sectional analysis of 49 years of breeding data shows annual recruit production to decline from 3.5 years of age, this decline affecting 9 per cent of females each year. Longitudinal analyses, however, show that selective disappearance of poor-quality breeders partly masks senescence, which in fact starts at 2.8 years and affects 21 per cent of females each year. There is no evidence for abrupt terminal effects. Analyses of underlying traits show no deterioration in clutch size, but significant declines in brood size and fledgling number. Furthermore, these traits contribute -9, 12 and 39 per cent to the senescent decline in recruit production, respectively. Besides providing detailed knowledge of the patterns and architecture of senescence in a natural population, these results illustrate the importance of modelling individual variation, and facilitate study of the underlying mechanisms of senescence.

Cutaneous T-cell lymphoma and atopy: is there an association?

BACKGROUND: Case reports have suggested a relationship between atopic diatheses and Sézary syndrome, pre-Sézary syndrome or mycosis fungoides. However, Sézary and pre-Sézary syndromes are rare entities, and this association has never been analysed in greater detail for specific subtypes of cutaneous T-cell lymphoma (CTCL). OBJECTIVES: To evaluate the prevalence of atopy in subjects with Sézary syndrome, pre-Sézary syndrome or mycosis fungoides, and to compare the rates with the reported prevalence of atopy in the general population. METHODS: We retrospectively reviewed the records of 157 patients with the diagnosis of Sézary or pre-Sézary syndrome seen between 1965 and 2000, and 102 patients with the diagnosis of mycosis fungoides evaluated from 1994 to 2000 at Mayo Clinic. RESULTS: Of 157 subjects with Sézary or pre-Sézary syndrome and 102 subjects with mycosis fungoides, 18 and 12, respectively, were identified as having a history of atopic dermatitis, asthma or allergic rhinitis. The prevalence rates of atopy in Sézary or pre-Sézary syndrome and mycosis fungoides were 11.5% (95% confidence interval 6.9-17.5%) and 11.8% (6.2-19.7%), respectively. CONCLUSIONS: No significant difference exists in the prevalence of atopy in Sézary or pre-Sézary syndrome compared with that in mycosis fungoides (chi2-test, P = 1.00). Furthermore, the rates of atopy in Sézary or pre-Sézary syndrome and mycosis fungoides are not significantly different from the prevalence of atopy in the general population (17-40%). On the basis of these observations, no evidence currently implicates a causal association of CTCL with atopy.

Sézary syndrome: a summary.

Sézary syndrome is the leukemic form of primary cutaneous T-cell lymphoma. It is an aggressive disease, with the lowest reported median survival of all cutaneous lymphomas. Patients with Sézary syndrome live with the awareness that they are suffering from an incurable disease. Having to cope daily with extensive skin care regimens, these patients can benefit tremendously from the expertise of dermatology nurses, who can teach them skin selfcare and who are aware of the psychologic impact of this disease. The symptoms, treatments, and emotional distress related to Sézary syndrome are summarized.

Dithranol in a cream preparation: disperse or dissolve?

In the search for the ideal dithranol cream preparation for short-contact treatment of psoriasis, we investigated the clinical efficacy, side effects and patient appreciation of two dithranol cream preparations (cream A and B) in a double-blind left-right comparing study. Dithranol was dissolved at preparation in cream A and dispersed in cream B. Cream A is known to have a shelf life of 1 year, while cream B has a much shorter shelf life (several months). Ten patients with chronic plaque-type psoriasis were treated during 7 weeks in a short-contact regimen. The clinical efficacy was monitored by scoring of erythema, induration, scaling and involved area (PASI); skin irritation was scored visually, and patient appreciation was evaluated by means of a multiple-choice questionnaire. Dispersion of dithranol in a cream was associated with less irritation and less discoloration of the skin, and its efficacy was comparable with that of the cream in which the dithranol was dissolved. As the dispersed dithranol formulation is easier to be manufactured, its quality will be less depending on the pharmacist's experience and equipment, and so more reliable. Besides, it will be less expensive to prepare. We advise to use this formulation for short-contact treatment.