Impact of an invasive alien plant on litter decomposition along a latitudinal gradient

Invasive alien plant effects on ecosystem functions are often difficult to predict across environmental gradients due to the context-dependent interactions between the invader and the recipient communities. Adopting a functional trait-based framework could provide more mechanistic predictions for invasive species' impacts. In this study, we contrast litter decomposition rates among communities with and without the invasive plant Impatiens glandulifera in five regions along a 1600 km long latitudinal gradient in Europe. Across this gradient, four functional traits, namely leaf dry matter content (LDMC), specific leaf area (SLA), stem-specific density (SSD), and plant height, are correlated to rates of litter decomposition of standardized rooibos (labile), green tea (recalcitrant), and I. glandulifera litter. Our results show that both invaded and non-invaded plant communities had a higher expression of acquisitive traits (low LDMC and SSD, high SLA) with increasing temperature along the latitudinal gradient, partly explaining the variation in decomposition rates along the gradient. At the same time, invasion shifted community trait composition toward more acquisitive traits across the latitudinal gradient. These trait changes partly explained the increased litter decomposition rates of the labile litter fraction of rooibos and I. glandulifera litter in invaded communities, a shift that was most evident in the warmer study regions. Plant available nitrogen was lower in invaded communities, likely due to high nutrient uptake by I. glandulifera. Meanwhile, the coldest study region was characterized by a reversed effect of invasion on decomposition rates. Here, community traits related to low litter quality and potential allelopathic effects of the invader resulted in reduced litter decomposition rates, suggesting a threshold temperature at which invader effects on litter decomposition turn positive. This study therefore illustrates how functional trait changes toward acquisitive traits can help explain invader-induced changes in ecosystem functions such as increased litter decomposition

Infrared Mapper (IRMA) for Support of Comet Sample Return Missions

Comets are remnants from the formation of the Solar System, and contain the most pristine material available today for deciphering the physical and chemical conditions of this process. As such, they are very interesting candidates for sample return missions, as indicated for example by the recent mission proposals CAESAR, CONDOR, and CORSAIR to the NASA New Frontiers 4 call. For maximizing the science return from such a mission the optimum selection of sampling site(s) is crucial. To support this selection we propose a remote sensing instrument working in the thermal infrared (TIR) wavelength range

LUBAC assembles a ubiquitin signaling platform at mitochondria for signal amplification and transport of NF-κB to the nucleus

Mitochondria are increasingly recognized as cellular hubs to orchestrate signaling pathways that regulate metabolism, redox homeostasis, and cell fate decisions. Recent research revealed a role of mitochondria also in innate immune signaling; however, the mechanisms of how mitochondria affect signal transduction are poorly understood. Here, we show that the NF-κB pathway activated by TNF employs mitochondria as a platform for signal amplification and shuttling of activated NF-κB to the nucleus. TNF treatment induces the recruitment of HOIP, the catalytic component of the linear ubiquitin chain assembly complex (LUBAC), and its substrate NEMO to the outer mitochondrial membrane, where M1- and K63-linked ubiquitin chains are generated. NF-κB is locally activated and transported to the nucleus by mitochondria, leading to an increase in mitochondria-nucleus contact sites in a HOIP-dependent manner. Notably, TNF-induced stabilization of the mitochondrial kinase PINK1 furthermore contributes to signal amplification by antagonizing the M1-ubiquitin-specific deubiquitinase OTULIN. Overall, our study reveals a role for mitochondria in amplifying TNF-mediated NF-κB activation, both serving as a signaling platform, as well as a transport mode for activated NF-κB to the nuclear

Uptake Mechanism of ApoE-Modified Nanoparticles on Brain Capillary Endothelial Cells as a Blood-Brain Barrier Model

Background: The blood-brain barrier (BBB) represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE) appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. Methodology/Principal Findings: In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. Conclusions/Significance: This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier

Recent epidemiological studies on ionizing radiation and childhood cancer in Germany

Purpose: The results from recent epidemiological studies based on the German Childhood Cancer Registry are summarized. Materials and methods: An oecological study covers 16 years' incidence of childhood malignancies in areas surrounding nuclear facilities and in matched control regions. Two population-based case-control studies explore potential risk factors of childhood leukaemia in the state of Lower Saxony (1988-93) and in all western states of Germany (1992-94). Results: There was no increased incidence of childhood leukaemia and other malignancies in the vicinity of nuclear installations. X-ray examinations during pregnancy and in early childhood were not associated with an increased risk of childhood leukaemia. There were no data to support Gardner's hypothesis of an increased risk due to paternal pre-conception exposure to ionizing radiation. Following the Chernobyl accident, the reported incidence of neuroblastoma and infant leukaemia was increased. The increase cannot be explained by exposures due to the accident. Conclusions: Although the carcinogenic effect of ionizing radiation is well known, the recent population-based epidemiological studies show that under current conditions exposure to ionizing radiation in Germany does not constitute risks of childhood malignancies that are relevant to public health

2nd malignant neoplasms in Germany after childhood malignancies

Since 1980 the German Registry of Childhood Malignancies has been established. In the framework of the long-term follow-up secondary malignancies are reported continually to the registry. An additional retrospective inquiry to all treating clinicians and principal investigators of clinical trials as well as a link to a previously existing pool of secondary malignancies (1) lead to a completion of the data. At the registry now 329 patients with second malignant neoplasms have been observed. 41,3% of them had been developed the first malignancy before the registry started its work in 1980. The most common primary malignancies are acute lymphoblastic leukaemia (ALL, 28.6%), brain tumours (12.2%), and retinoblastomas (8.8%). Compared to the population of the registry retinoblastomas as a secondary malignancy occur in excess (2.5% vs 8.8%). Most common secondary malignancies are brain tumours (20.1%), acute non-lymphoblastic leukaemia (13.1%), osteosarcomas (10.9%), and thyroid carcinomas (6.1%). Hereby especially for thyroid cancer a remarkable deviation from the frequency in the total population of the registry (0.2%) is observed. In 3% of the patients a secondary malignancy appears within a span of 10 years after the primary malignancy. This is a twentyfold increase compared with the cumulative rate of developing a malignancy in the first 10 years of life. Brain tumours after ALL (8.5%) and after other brain tumours (5.8%) and osteosarcomas after retinoblastomas (4.9%) are the most often reported combinations. In our data the median of time interval between occuring of the primary and the secondary cancer is 5 years 10 months for all malignancies; in retinoblastomas the longest time intervals has been observed (median 12 years 5 months)

Applicability of the poisson-distribution to model the data of the German childrens cancer registry

Since 1980 the German Children's Cancer Registry has documented all childhood malignancies in the Federal Republic of Germany. Various statistical procedures have been proposed to identify municipalities or other geographic units with increased numbers of malignancies. Usually the Poisson distribution, which requires the malignancies to be distributed homogeneously and uncorrelated, is applied. Other discrete statistical distributions (so-called cluster distributions) like the generalized or compound Poisson distributions are applicable more generally. In this paper we present a first explorative approach to the question of whether it is necessary to use one of these cluster distributions to model the data of the German Children's Cancer Registry. In conclusion, we find no indication that the Poisson approach is insufficient