Lost in the hybridisation vortex: high-elevation <Emphasis Type="Italic">Senecio hercynicus</Emphasis> (Compositae,Senecioneae) is genetically swamped by its congener <Emphasis Type="Italic">S. ovatus</Emphasis> in the Bavarian Forest National Park (SE Germany)

Hybridisation is an important evolutionary process. The investigation of hybridisation along elevational gradients, with their steep abiotic and biotic clines, provides insight into the adaptation and maintenance of species in adjacent habitats. The rare Senecio hercynicus and its spreading congener S. ovatus are vertically vicariant species that show hybridisation in their range overlaps. In the present study, we used AFLP fingerprinting of 689 individuals from 38 populations to analyse population structure and introgression patterns along four elevational transects (650–1350 m) in the Bavarian Forest National Park, Gemany. Subsequently, we searched for loci putatively under divergent selection that may maintain ‘pure’ species despite hybrid formation by identifying taxon-specific alleles. A maximum-likelihood based hybrid index shows that the overall genetic differentiation among all populations was very low with a vanishingly small number of pure parental individuals. Almost 75% of the investigated individuals were classified as backcrosses towards S. ovatus. The highest S. hercynicus ancestry was found in the uppermost populations of two transects. Further, we found seven taxon-specific alleles being under divergent selection that correlated with climatic variables and deviating from neutral introgression. According to our results, hybridisation of S. ovatus and S. hercynicus has reached an advanced state of genetic swamping and there seems to be no driving force that is strong enough to keep both species as different lineages. Rather, S. ovatus appears to benefit through putatively adaptive introgression.     

The difficult legacy of Turing’s wager

Neuron modeling may be said to have originated with the Hodgkin and Huxley action potential model in 1952 and Rall’s models of integrative activity of dendrites in 1964. Over the ensuing decades, these approaches have led to a massive development of increasingly accurate and complex data-based models of neurons and neuronal circuits. ModelDB was founded in 1996 to support this new field and enhance the scientific credibility and utility of computational neuroscience models by providing a convenient venue for sharing them. It has grown to include over 1100 published models covering more than 130 research topics. It is actively curated and developed to help researchers discover and understand models of interest. ModelDB also provides mechanisms to assist running models both locally and remotely, and has a graphical tool that enables users to explore the anatomical and biophysical properties that are represented in a model. Each of its capabilities is undergoing continued refinement and improvement in response to user experience. Large research groups (Allen Brain Institute, EU Human Brain Project, etc.) are emerging that collect data across multiple scales and integrate that data into many complex models, presenting new challenges of scale. We end by predicting a future for neuroscience increasingly fueled by new technology and high performance computation, and increasingly in need of comprehensive user-friendly databases such as ModelDB to provide the means to integrate the data for deeper insights into brain function in health and disease.     

Silibinin ameliorates Aβ<Subscript>25-35</Subscript>-induced memory deficits in rats by modulating autophagy and attenuating neuroinflammation as well as oxidative stress

Alzheimer’s disease (AD) is a progressive, neurodegenerative disease. Accumulating evidence suggests that inflammatory response, oxidative stress and autophagy are involved in amyloid β (Aβ)-induced memory deficits. Silibinin (silybin), a flavonoid derived from the herb milk thistle, is well known for its hepatoprotective activities. In this study, we investigated the neuroprotective effect of silibinin on Aβ_25-35-injected rats. Results demonstrated that silibinin significantly attenuated Aβ_25-35-induced memory deficits in Morris water maze and novel object-recognition tests. Silibinin exerted anxiolytic effect in Aβ_25-35-injected rats as determined in elevated plus maze test. Silibinin attenuated the inflammatory responses, increased glutathione (GSH) levels and decreased malondialdehyde (MDA) levels, and upregulated autophagy levels in the Aβ_25-35-injected rats. In conclusion, silibinin is a potential candidate for AD treatment because of its anti-inflammatory, antioxidant and autophagy regulating activities.     

Natural variation reveals contrasting abilities to cope with alkaline and saline soil among different <Emphasis Type="Italic">Medicago truncatula</Emphasis> genotypes

Aims

Urban soils are the basis of many ecosystem services in cities. Here, we examine formerly residential vacant lot soils in Cleveland, Ohio and Detroit, Michigan, USA for their potential to provide multiple ecosystem services. We examine two key contrasts: 1) differences between cities and 2) differences within vacant lots created during demolition, specifically pre-existing (i.e., prior to demolition) soils outside of the building footprint and fill soils added within the former building’s footprint.

Methods

Deep soil cores were collected from vacant lots in Cleveland and Detroit. Soil properties that are proxies for three ecosystem services were measured: hydraulic conductivity for stormwater retention, topsoil depth and soil nitrogen (N) level for support for plant growth, and soil carbon (C) content for C storage.

Results

Both city and soil group contrasts created distinct ecosystem service provisioning based on proxy measures. Cleveland soils had greater hydraulic conductivity and greater soil C and N levels but thinner topsoil layers than Detroit. Within vacant lots of both cities, pre-existing soils had greater soil C and N levels, but lower hydraulic conductivity values than fill soils.

Conclusions

Soil properties of vacant lots were generally suitable for providing multiple ecosystem services. City-level differences in soil properties created differences in ecosystem service potential between cities and these differences were evident in pre-existing and fill soils. When comparing between cities, though, fill soils were more similar than pre-existing soils indicating some homogenization of ecosystem service potential with greater redistribution of soil.

     

Community-based natural resource use and management of Bigodi Wetland Sanctuary,Uganda, for livelihood benefits

Conservation and sustainable management of wetlands requires participation of local stakeholders, including communities. The Bigodi Wetland is unusual because it is situated in a common property landscape but the local community has been running a successful community-based natural resource management programme (CBNRM) for the wetland for over a decade. Whilst external visitors to the wetland provide ecotourism revenues we sought to quantify community benefits through the use of wetland goods such as firewood, plant fibres, and the like, and costs associated with wild animals damaging farming activities. We interviewed 68 households living close to the wetland and valued their cash and non-cash incomes from farming and collection of non-timber forest products (NTFPs) and water. The majority of households collected a wide variety of plant and fish resources and water from the wetland for household use and livestock. Overall, 53% of total household cash and non-cash income was from collected products, mostly the wetland, 28% from arable agriculture, 12% from livestock and 7% from employment and cash transfers. Female-headed households had lower incomes than male-headed ones, and with a greater reliance on NTFPs. Annual losses due to wildlife damage were estimated at 4.2% of total gross income. Most respondents felt that the wetland was important for their livelihoods, with more than 80% identifying health, education, craft materials and firewood as key benefits. Ninety-five percent felt that the wetland was in a good condition and that most residents observed the agreed CBNRM rules regarding use of the wetland. This study confirms the success of the locally run CBNRM processes underlying the significant role that the wetland plays in local livelihoods.     

Impairment of <Emphasis Type="Italic">ntc</Emphasis>A gene revealed its role in regulating iron homeostasis,ROS production and cellular phenotype under iron deficiency in cyanobacterium <Emphasis Type="Italic">Anabaena</Emphasis> sp. PCC 7120

Iron deficiency ends up into several unavoidable consequences including damaging oxidative stress in cyanobacteria. NtcA is a global nitrogen regulator controls wide range of metabolisms in addition to regulation of nitrogen metabolism. In present communication, NtcA based regulation of iron homeostasis, ROS production and cellular phenotype under iron deficiency in Anabaena 7120 has been investigated. NtcA regulates the concentration dependent iron uptake by controlling the expression of furA gene. NtcA also regulated pigment synthesis and phenotypic alterations in Anabaena 7120. A significant increase in ROS production and corresponding reduction in the activities of antioxidative enzymes (SOD, CAT, APX and GR) in CSE2 mutant strain in contrast to wild type Anabaena 7120 also suggested the possible involvement of NtcA in protection against oxidative stress in iron deficiency. NtcA has no impact on the expression of furB and furC in spite of presence of consensus NtcA binding site (NBS) and ?10 boxes in their promoter. NtcA also regulates the thylakoid arrangement as well as related photosynthetic and respiration rates under iron deficiency in Anabaena 7120. Overall results suggested that NtcA regulates iron acquisition and in turn protect Anabaena cells from the damaging effects of oxidative stress induced under iron deficiency.