Dynamics of natural populations of the dertitivorous mudsnail Potamopyrgus antipodarum (Gray) (Hydrobiidae) in two interconnected Lakes differing in trophic state

Here we investigate the allocation of resources between growth and reproduction by surveying the dynamics of natural populations of the aquatic detritivorous mudsnail Potamopyrgus antipodarum from two interconnected lakes that differ in trophic state. The size distributions and reproductive output of the snail populations was analyzed monthly by field surveys spanning 3 years, and in a controlled microcosm experiment to evaluate the reproductive potential under laboratory conditions. Snails in the meso-oligotrophic lake showed reduced growth and a smaller size compared to snails in the eutrophic lake. However, the numbers of eggs and nearly-neonates per adult snail did not differ significantly between the two populations. It is speculated that P. antipodarum populations living under meso-oligotrophic conditions may consistently invest more internal energy in reproduction at the expense of growth and that food quantity may be an important driver for macro-invertebrate resource allocation in detrital food webs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-3-736) contains supplementary material, which is available to authorized users

Inkuilen van eendenkroos als veevoer met verschillende additieven = Ensiling Duckweed for feed with different additives

Ferment duckweed as silage is a cheap and sustainable alternative for drying. Without an additive, no satisfying preservation result was reached. Molasses gave a good preservation result and is relatively cheap and practical. Common methods of forage ensilaging are not suitable for duckweed as they have too little product structure to facilitate wrapping. The use of an airtight container or silo may lead to good preservation results, and prevent losses

The Impact of Socioeconomic Status, Surgical Resection and Type of Hospital on Survival in Patients with Pancreatic Cancer:A Population-Based Study in The Netherlands

The influence of socioeconomic inequalities in pancreatic cancer patients and especially its effect in patients who had a resection is not known. Hospital type in which resection is performed might also influence outcome. Patients diagnosed with pancreatic cancer from 1989 to 2011 (n = 34,757) were selected from the population-based Netherlands Cancer Registry. Postal code was used to determine SES. Multivariable survival analyses using Cox regression were conducted to discriminate independent risk factors for death. Patients living in a high SES neighborhood more often underwent resection and more often were operated in a university hospital. After adjustment for clinicopathological factors, risk of dying was increased independently for patients with intermediate and low SES compared to patients with high SES. After resection, no survival difference was found among patients in the three SES groups. However, survival was better for patients treated in university hospitals compared to patients treated in non-university hospitals. Low SES was an independent risk factor for poor survival in patients with pancreatic cancer. SES was not an adverse risk factor after resection. Resection in non-university hospitals was associated with a worse prognosis.</p

IMMUNOSENESCENCE AND ITS IMPACT ON MEDICAL PRACTICE. A NEW LOOK AT AN OLD PROBLEM.

Introdução:O envelhecimento é um processo complexo que influencia todos os sistemas do corpo humano e seu impacto no sistema imune é chamado Imunosenescência. Essa condição é resultado de várias modulações imunológicas causadas por interações entre fatores genéticos e ambientais e é responsável por importantes condições clínicas em indivíduos idosos como alta prevalência de doenças infecciosas e autoimunes, neoplasias e menor eficácia de vacinas. Objetivo: Nesta revisão serão discutidos os problemas clínicos mais comuns na população idosa relacionados a Imunosenescência, e os novos achados da ciência básica relevantes a este tópico. Conclusão: A melhor compreensão da Imunosenescência é importante para prevenção de doenças comuns relacionadas à idade e para a promoção de um envelhecimento saudável.Background: Ageing is a very complex process that modulates all the organ systems of the human body, and its impact on the immune system is called Immunosenescence. This condition is the result of several immune modulations due to genetic and environmental interactions and is responsible for important clinical conditions in elderly subjects, such as a higher incidence of infectious and autoimmune diseases, neoplasias and decreased vaccine efficacy. Objective: In this current review we will discuss the most common clinical problems in the elderly population related to Immunosenescence and new findings in basic science relevant to this topic. Conclusion: A better understanding of Imunosenescence is important to prevention of common age related diseases and for the promotion of healthy ageing

Leaf epinasty in chrysanthemum: enabling breeding against an adverse trait by physiological research

Breeding for a certain trait is only possible when the phenotypic variation that is caused by genotypic variation can be estimated. For traits that strongly depend on environmental conditions, this can be extremely difficult and knowledge and collaboration with experts from other disciplines becomes essential. A well-known example is breeding for disease resistance. Here, we describe a similar approach to assist breeding against adverse leaf deformations that severely reduce the ornamental value of some chrysanthemum (Dendranthema × grandiflora) genotypes during greenhouse cultivation in winter. These leaf deformations occur rather unpredictably, but seem to be related to the increased use of assimilation light. To breed against this trait knowledge is needed (i) about inductive environments in which sensitive and insensitive genotypes are distinguishable, and (ii) about the physiological background associated with leaf epinasty. In this paper hypothetical physiological factors and mechanisms are discussed, which may mediate effects of light spectrum and greenhouse climate on leaf epinasty. One factor involved could be starch accumulation, since leaf epinasty usually aggravates after disbudding - a practice that most probably alters the sink-source balance. Additionally, light spectra can affect the circadian clock and thereby disturb starch synthesis and breakdown resulting in accumulation. Both within and independent of this process, plant hormones such as auxin and ethylene may play a role in leaf epinasty. This theoretical framework will be used to further investigate the physiological background of leaf epinasty and to come up with a test in which susceptibility for leaf epinasty can be assessed

Genotypic differences in metabolomics changes during storage induced-degreening of chrysanthemum disk florets

Plant science