Aerobic endurance training versus relaxation training in patients with migraine (ARMIG): study protocol for a randomized controlled trial

ABSTRACT: BACKGROUND: Migraine is one of the most frequent headache diseases and impairs patients' quality of life. Up to now, many randomized studies reported efficacy of prophylactic therapy with medications such as beta-blockers or anti-epileptic drugs. Non-medical treatment, like aerobic endurance training, is considered to be an encouraging alternative in migraine prophylaxis. However, there is still a lack of prospective, high-quality randomized trials. We therefore designed a randomized controlled trial to evaluate the efficacy of aerobic endurance training versus relaxation training in patients with migraine (ARMIG). METHODS: This is a single-center, open-label, prospective, randomized trial. Sixty participants with migraine are randomly allocated to either endurance training or a relaxation group. After baseline headache diary documentation over at least 4 weeks, participants in the exercise group will start moderate aerobic endurance training under a sport therapist's supervision at least 3 times a week over a 12-week period. The second group will perform Jacobson's progressive muscle relaxation training guided by a trained relaxation therapist, also at least 3 times a week over a 12-week period. Both study arms will train in groups of up to 10 participants. More frequent individual training is possible. The follow-up period will be 12 weeks after the training period. The general state of health, possible state of anxiety or depression, impairments due to the headache disorder, pain-related disabilities, the headache-specific locus of control, and the motor fitness status are measured with standardized questionnaires. DISCUSSION: The study design is adequate to generate meaningful results. The trial will be helpful in gaining important data on exercise training for non-medical migraine prophylaxis. Trial registration The trial is registered at ClinicalTrials.gov: NCT01407861.     

Shielded environments reduce stress in alien Asteraceae species during hot and dry summers along urban‐to‐rural gradients

Urban environments often host a greater abundance and diversity of alien plant species than rural areas. This is frequently linked to higher disturbance and propagule pressure, but could also be related to the additional establishment of species from warmer native ranges in cities, facilitated by the latter''s higher air temperatures and drier soils. A hitherto unresolved question is how stressful the urban environments become during climate extremes such as heatwaves and droughts. Do such episodes still favor alien plant species, or set them back? We used in situ measured phenotypic leaf and development trait responses of the six most widespread alien Asteraceae species from various native climates along Belgian urban‐to‐rural gradients, measured during two unusually warm and dry summers. Urbanization was characterized by three factors: the percentage of artificially sealed surfaces (urbanity, measured at three spatial scales from in situ to satellite‐based), the vegetation cover and the sky view factor (SVF, fraction of the hemisphere not blocked by buildings or vegetation). Across species, either from colder or warmer native climates, we found a predominant protective effect of shielded environments that block solar radiation (low SVF) along the entire urban‐to‐rural gradient. Such environments induced lower leaf anthocyanins and flavonols indices, indicating heat stress mitigation. Shielded environments also increased specific leaf area (SLA), a typical shade response. We found that vegetated areas had a secondary importance, increasing the chlorophyll content and decreasing the flavonols index, but these effects were not consistent across species. Finally, urbanity at the organism spatial scale decreased plant height, while broader‐scale urbanity had no significant influence. Our results suggest that sealed surfaces constrain alien Asteraceae during unusually warm and dry summers, while shielded environments protect them, possibly canceling out the lack of light. These findings shed new light on alien plant species success along urban‐to‐rural gradients in a changing climate.     

The fission yeast Rad32 (Mre11)-Rad50-Nbs1 complex is required for the S-phase DNA damage checkpoint

Mre11, Rad50, and Nbs1 form a conserved heterotrimeric complex that is involved in recombination and DNA damage checkpoints. Mutations in this complex disrupt the S-phase DNA damage checkpoint, the checkpoint which slows replication in response to DNA damage, and cause chromosome instability and cancer in humans. However, how these proteins function and specifically where they act in the checkpoint signaling pathway remain crucial questions. We identified fission yeast Nbs1 by using a comparative genomic approach and showed that the genes for human Nbs1 and fission yeast Nbs1 and that for their budding yeast counterpart, Xrs2, are members of an evolutionarily related but rapidly diverging gene family. Fission yeast Nbs1, Rad32 (the homolog of Mre11), and Rad50 are involved in DNA damage repair, telomere regulation, and the S-phase DNA damage checkpoint. However, they are not required for G(2) DNA damage checkpoint. Our results suggest that a complex of Rad32, Rad50, and Nbs1 acts specifically in the S-phase branch of the DNA damage checkpoint and is not involved in general DNA damage recognition or signaling.     

Functional Principles of Posterior Septal Inputs to the Medial Habenula

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Long‐term dynamics in microbial eukaryotes communities: a palaeolimnological view based on sedimentary DNA

Assessing the extent to which changes in lacustrine biodiversity are affected by anthropogenic or climatic forces requires extensive palaeolimnological data. We used high‐throughput sequencing to generate time‐series data encompassing over 2200 years of microbial eukaryotes (protists and Fungi) diversity changes from the sedimentary DNA record of two lakes (Lake Bourget in French Alps and Lake Igaliku in Greenland). From 176 samples, we sequenced a large diversity of microbial eukaryotes, with a total 16 386 operational taxonomic units distributed within 50 phylogenetic groups. Thus, microbial groups, such as Chlorophyta, Dinophyceae, Haptophyceae and Ciliophora, that were not previously considered in lacustrine sediment record analyses appeared to be potential biological markers of trophic status changes. Our data suggest that shifts in relative abundance of extant species, including shifts between rare and abundant taxa, drive ecosystem responses to local and global environmental changes. Community structure shift events were concomitant with major climate variations (more particularly in Lake Igaliku). However, this study shows that the impacts of climatic fluctuations may be overpassed by the high‐magnitude eutrophication impacts, as observed in the eutrophicated Lake Bourget. Overall, our data show that DNA preserved in sediment constitutes a precious archive of information on past biodiversity changes.     

Tracing nitrate sources using the isotopic composition of skeletal-bound organic matter from the calcareous green algae Halimeda

Coral Reefs - The nitrogen (N) isotopic composition (δ15N) of water column nitrate (NO3−) reveals important information about the source(s) of N, and/or the transformation processes...     

Comparative genetic diversity in a sample of pony breeds from the U.K. and North America: a case study in the conservation of global genetic resources

Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and a panel of microsatellite markers. Genetic signatures differed between the North American subpopulations according to historical management processes. Founder effect and stochastic drift was apparent, particularly pronounced in some breeds, with evidence of admixture of imported mares of different North American breeds. This demonstrates the importance of analysis of subpopulations to facilitate understanding the genetic effects of past management practices and to lead to informed future conservation strategies.     

ATM activation and its recruitment to damaged DNA require binding to the C terminus of Nbs1

ATM has a central role in controlling the cellular responses to DNA damage. It and other phosphoinositide 3-kinase-related kinases (PIKKs) have giant helical HEAT repeat domains in their amino-terminal regions. The functions of these domains in PIKKs are not well understood. ATM activation in response to DNA damage appears to be regulated by the Mre11-Rad50-Nbs1 (MRN) complex, although the exact functional relationship between the MRN complex and ATM is uncertain. Here we show that two pairs of HEAT repeats in fission yeast ATM (Tel1) interact with an FXF/Y motif at the C terminus of Nbs1. This interaction resembles nucleoporin FXFG motif binding to HEAT repeats in importin-beta. Budding yeast Nbs1 (Xrs2) appears to have two FXF/Y motifs that interact with Tel1 (ATM). In Xenopus egg extracts, the C terminus of Nbs1 recruits ATM to damaged DNA, where it is subsequently autophosphorylated. This interaction is essential for ATM activation. A C-terminal 147-amino-acid fragment of Nbs1 that has the Mre11- and ATM-binding domains can restore ATM activation in an Nbs1-depleted extract. We conclude that an interaction between specific HEAT repeats in ATM and the C-terminal FXF/Y domain of Nbs1 is essential for ATM activation. We propose that conformational changes in the MRN complex that occur upon binding to damaged DNA are transmitted through the FXF/Y-HEAT interface to activate ATM. This interaction also retains active ATM at sites of DNA damage.     

Influence of spatial heterogeneity on an emerging infectious disease: the case of dengue epidemics

The importance of spatial heterogeneity and spatial scales (at a village or neighbourhood scale) has been explored with individual-based models. Our reasoning is based on the Chilean Easter Island (EI) case, where a first dengue epidemic occurred in 2002 among the relatively small population localized in one village. Even in this simple situation, the real epidemic is not consistent with homogeneous models. Conversely, including contact heterogeneity on different scales (intra-households, inter-house, inter-areas) allows the recovery of not only the EI epidemiological curve but also the qualitative patterns of Brazilian urban dengue epidemic in more complex situations.