154 research outputs found
Shrub diversity in Mediterranean shrublands: Rescuer or victim of productivity?
[ENG]Aims: Unravelling the most prevalent causal direction between diversity and function in naturally recovered plant assemblages can greatly improve our understanding of the functional significance of diversity and its applications under the ongoing envi- ronmental changes. In this study, we apply a structural equation model framework to unravel the most plausible causal direction in the diversity–productivity relationship in subseral Mediterranean shrub-dominated communities.
Methods: Total shrub cover (as a proxy of productivity when controlled by the time since land use cessation or the last wildfire), the number of species, and the number of functional types based on the dominant life forms (phanerophytes vs. chamaephytes), and the dominant foliar syndromes (deciduous vs. evergreen, needled vs. broad- leaved), were sampled in 195 circular plots distributed along an elevation gradient ranging from 400 to 1400 m a.s.l. in the Central Iberian Peninsula. We first explored the distribution of functional types along the elevation gradient using a non-metric multidimensional scaling (NMDS). Secondly, a structural equation model (SEM) frame- work using mixed-effects models was defined to unveil the prevalent causal direction between diversity (species and functional types) and productivity at the landscape scale.
Results: Model selection using the Fisher's C information criterion supported a causal direction from total shrub cover to diversity in this landscape. Interestingly, the best supported model also supported a positive relationship between species richness and the number of functional types, which in turn is driven by the total shrub cover along the elevation gradient.
Conclusions: Our results suggest that more species might not necessarily boost pro- ductivity. On the contrary, ongoing warming temperatures and aridity, which are characteristic of low elevations compared to highlands, might significantly reduce the number of species (victim rather than rescuer) through deleterious effects on productivity
The Effects of Native Shrub, Fencing, and Acorn Size on the Emergence of Contrasting Co-Occurring Oak in Mediterranean Grazed Areas
[ENG]Research Highlights: The regeneration of Quercus species is usually very difficult in many
oak woodlands transformed by livestock farming. Some studies have reported that shrubs can
facilitate regeneration. However, the strength of interaction may vary depending on, among other
factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are
necessary to clarify the relative importance of the two facilitation mechanisms in the same community.
Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in
the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula
(bioclimatic limit) and is present with Quercus pyrenaicaWilld and Quercus ilex subsp. ballota Samp
trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding
large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under
a bioclimatic limit. Materials and Methods: A manipulative field experiment was carried out
considering four treatments as a combination of shrubs (shrub/no-shrub) and fence (fenced/open)
factors. A total of twenty plots, five replicates for each treatment were available. In each plot,
20 acorns were sown: 10 acorns (5 small and 5 large) for each Quercus species. Acorn emergence was
recorded during the first four years following the sowing. Results: Seedling emergence took place
mostly in the spring of the first year after sowing. The presence of shrub was the main significant
factor and incremented the emergence of both Q. ilex and Q. pyrenaica. The effect of the fence
depended on the Quercus species considered, improving only the emergence of Q. pyrenaica. A
negative effect with the small acorns was detected but only for Q. pyrenaica. In all treatments, Q. ilex
emerged more than Q. pyrenaica. Conclusions: C. multiflorus had a clear facilitative effect on the
seedling emergence of Q. ilex and Q. pyrenaica, which was much greater than the physical effect that
acorn size and excluding large herbivores had. As such, this native shrub may have a key role in
oak regeneration in Mediterranean grazed areas. Furthermore, in these areas of contact between
marcescent and sclerophyllous Quercus species, Q. ilex currently emerges more than Q. pyrenaica. This
could be indicative of a shift towards more xeric climatic conditions, which could lead to a change in
the dominant tree species in the future. However, this change could be modulated by the effects of
native shrub and large herbivores
Effect of the mother tree age and acorn weight in the regenerative characteristics of Quercus faginea
[EN] The establishment of oak trees is often a slow and difficult process. Hence, it is necessary to determine the characteristics that can lead to improving their regeneration. In this genus, seed size is highly variable both at the interspecific and intraspecific
levels, and the effects of intrapopulation variability are not well understood, being even less so for Quercus faginea. In this
study, the effects of the age of the mother tree, seed weight and the interaction between these two factors on seed germination,
emergence and growth (biomass) were analysed. For this purpose, 16 trees—8 young and 8 old—were selected with the intent
to cover the entire range of acorn weights produced in this population. Among the main results, it should be noted that: (1)
in older trees, it is easier to find larger acorns; (2) the percentage and the speed of germination of the acorns of young trees
is greater than that of old trees; (3) the percentage and the speed of seedling emergence of young trees is greater than that
of old trees; and (4) cotyledon weight is the variable that most influences biomass, quite often in a positive way. Therefore,
maintaining intrapopulation variability seems to be an approach that most favours the persistence of these populations
Effect of the forest-mine boundary form on woody colonization and forest expansion in degraded ecosystems
[ENG]We evaluated the ecological significance of the boundary form between two patches
with contrasting vegetation (mine grassland and adjacent forest) on woody colonization and forest
expansion in open-cast coal mines in Northern Spain. Woody colonization and browsing traces
were measured on three mine sites, along 24 transects that were laid out perpendicular to the
forest-mine boundary and classified according to their shape (concave, convex, straight). Mine sites
were colonized from the close forest by woody species, whose colonization intensity depends on
the boundary form. The overall colonization intensity decreased with increasing distance to the
forest and differed depending on the boundary form. The more intense colonization was found in
concave boundaries and the strongest decrease in convex boundaries close to the forest, whereas
straight boundaries showed an intermediate colonization pattern. Concave boundaries reached
higher woody cover in the basal strata of the mines than convex (up to 2 m) or straight boundaries
(up to 1 m) from 11 m to the forest edge, mainly by the presence of dense patches of Cytisus scoparius
(L.) Link, with a scattered overstory of Genista florida L. These shrubs might reduce the browsing
intensity and act as nurse plants facilitating the establishment of Quercus petraea (Matt.) Liebl. in
mine areas at greater distances from the forest edge. The forest-mine boundary form does not affect
the forest vertical structure that is homogenous and does not help explain the woody colonization
pattern in the mines. We conclude that edge characteristics have a strong potential to be used in the
restoration of native forests based on natural processes. The implications of our results for sessile
oak (Quercus petraea (Matt.) Liebl.) forest expansion along edges in fragmented Mediterranean forest
landscapes were discussed
Towards a Sustainable Campus: Working Together to Achieve the Green Campus Flag on the UDC Peripheral Campus of Ferrol
[Abstract] Purpose. This paper aims to present and describe the main actions carried out in six different faculties and common areas such as cultural and research centres and administrative buildings in the Ferrol campus at the University of A Coruña to achieve the second green flag on a Galician University.
Design/methodology/approach. A case study describing the steps for implementing a green campus programme in a medium-size, young university campus integrated into a small city. An Environmental Campus Committee was created to assess the main factors that affect environmental footprint, discuss sustainability initiatives and develop a guide to action regarding different goals related to sustainable transport options, energy, water conservation and waste reduction. The actions included several fields such as education, circular economy and healthy life and involved the on and off-campus community.
Findings. The programme achieved a decrease in water consumption and electrical energy. An important change in educational values and behaviours regarding sustainability was observed in and out of the campus community. The measurements adopted mainly in waste management, mobility and education led the Ferrol campus to achieve a green campus flag on November 2019.
Originality/value. This experiment can serve as a guide to establish the Green Campus philosophy in other similar university campuses.The authors of this article want to thank the finantial and institutional support of Environmental Office of University of A Coruña to develop talks, activities and to implement different actions in Ferrol Campus. The authors of this article want to thank the finantial and institutional support of Vicerrectorado del Campus de Ferrol y Responsabilidad Social of University of A Coruña to achieve the Green Flag. Ana Ares-Pernas wants to thank the financial support of Vicerrectorado de Planificación Académica e Innovación Docente of University of A Coruña obtained in the I Edition of the Prizes for Teaching Innovation Projects in Service-Learning to develop Service-Learning activitie
The MRC1/CD68 ratio is positively associated with adipose tissue lipogenesis and with muscle mitochondrial gene expression in humans
This is an open-access article distributed under the terms of the Creative Commons Attribution License.[Background]: Alternative macrophages (M2) express the cluster differentiation (CD) 206 (MCR1) at high levels. Decreased M2 in adipose tissue is known to be associated with obesity and inflammation-related metabolic disturbances. Here we aimed to investigate MCR1 relative to CD68 (total macrophages) gene expression in association with adipogenic and mitochondrial genes, which were measured in human visceral [VWAT, n = 147] and subcutaneous adipose tissue [SWAT, n = 76] and in rectus abdominis muscle (n = 23). The effects of surgery-induced weight loss were also longitudinally evaluated (n = ).[Results]: MCR1 and CD68 gene expression levels were similar in VWAT and SWAT. A higher proportion of CD206 relative to total CD68 was present in subjects with less body fat and lower fasting glucose concentrations. The ratio MCR1/CD68was positively associated with IRS1gene expression and with the expression of lipogenic genes such as ACACA, FASN and THRSP, even after adjusting for BMI. The ratio MCR1/CD68 in SWAT increased significantly after the surgery-induced weight loss (+44.7%; p = 0.005) in parallel to the expression of adipogenic genes. In addition, SWAT MCR1/CD68ratio was significantly associated with muscle mitochondrial gene expression (PPARGC1A, TFAM and MT-CO3). AT CD206 was confirmed by immunohistochemistry to be specific of macrophages, especially abundant in crown-like structures. [Conclusion]: A decreased ratio MCR1/CD68 is linked to adipose tissue and muscle mitochondrial dysfunction at least at the level of expression of adipogenic and mitochondrial genes. © 2013 moreno-navarrete et al.This work was supported by grant SAF-2009-10461 and grant PI11-00214 from the Ministerio de Economía y Competitividad, Spain.Peer Reviewe
Regeneration dynamics in fragmented landscapes at the leading edge of distribution: Quercus suber woodlands as a study case
[EN] Aims
We studied the regeneration dynamics of woodlands and abandoned old fields in a landscape dominated by Quercus suber in its lower limits of rainfall and temperature. Two hypotheses were established: (1) regeneration of Quercus species is strongly favored by the presence of tree cover; and (2) growth of Q. suber is driven by the climatic variables that represent the lower ecological limit of its leading distribution edge.
Methods
We selected woodlands and old fields with and without tree remnants (n = 3 per type), and analyzed stand structure, soil parameters and tree growth.
Results
Succession was arrested in old fields without tree remnants. By contrast, remnant trees were accelerators of forest recovery in old fields. Tree cover played a fundamental role in Quercus recruitment throughout seed dispersal and facilitation that mitigate the effects of summer drought on seedlings. Also, tree cover improved soil parameters (e.g., organic matter) that are important factors for understanding differences in regeneration. Winter/spring precipitation exerted a positive effect on tree growth, as well as temperatures during winter/spring and September.
Conclusions
Regeneration dynamics are modeled by the density of tree cover in the cold and dry edge of the distribution area of Q. suber where Q. ilex is increasing in abundance. Although temperature has a positive effect on the tree growth of Q. suber, when demographic processes are considered, decreases in water availability likely play a critical role in Q. ilex recruitment. This in turn changes dominance hierarchies, especially in abandoned areas with little or no tree cover.This study was funded by project SA013G19 from “Junta de Castilla y León” and by research grants awarded for final projects directed in the Master’s degree in Biology and Conservation of Biodiversity at the University of Salamanca, Spain.Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL
Deep Phenotyping and Genetic Characterization of a Cohort of 70 Individuals With 5p Minus Syndrome.
Chromosome-5p minus syndrome (5p-Sd, OMIM #123450) formerly known as Cri du Chat syndrome results from the loss of genetic material at the distal region of the short arm of chromosome 5. It is a neurodevelopmental disorder of genetic cause. So far, about 400 patients have been reported worldwide. Individuals affected by this syndrome have large phenotypic heterogeneity. However, a specific phenotype has emerged including global developmental delay, microcephaly, delayed speech, some dysmorphic features, and a characteristic and monochromatic high-pitch voice, resembling a cat's cry. We here describe a cohort of 70 patients with clinical features of 5p- Sd characterized by means of deep phenotyping, SNP arrays, and other genetic approaches. Individuals have a great clinical and molecular heterogeneity, which can be partially explained by the existence of additional significant genomic rearrangements in around 39% of cases. Thus, our data showed significant statistical differences between subpopulations (simple 5p deletions versus 5p deletions plus additional rearrangements) of the cohort. We also determined significant "functional" differences between male and female individuals.S
QUIJOTE scientific results-I. Measurements of the intensity and polarisation of the anomalous microwave emission in the Perseus molecular complex
et al.In this paper, we present Q-U-I JOint Tenerife Experiment (QUIJOTE) 10–20 GHz observations (194 h in total over ≈250 deg2) in intensity and polarisation of G159.6-18.5, one of the most widely studied regions harbouring anomalous microwave emission (AME). By combining with other publicly available intensity data, we achieve the most precise spectrum of the AME measured to date in an individual region, with 13 independent data points between 10 and 50 GHz being dominated by this emission. The four QUIJOTE data points provide the first independent confirmation of the downturn of the AME spectrum at low frequencies, initially unveiled by the COSMOlogical Structures On Medium Angular Scales experiment in this region. Our polarisation maps, which have an angular resolution of ≈1° and a sensitivity of ≈ 25 μK beam−1, are consistent with zero polarisation. We obtain upper limits on the polarisation fraction of Π < 6.3 and <2.8 per cent (95 per cent C.L.), respectively, at 12 and 18 GHz (ΠAME < 10.1 and <3.4 per cent with respect to the residual AME intensity), a frequency range where no AME polarisation observations have been reported to date. The combination of these constraints with those from other experiments confirm that all the magnetic dust models based on single-domain grains, and most of those considering randomly oriented magnetic inclusions, predict higher polarisation levels than is observed towards regions with AME. Also, neither of the two considered models of electric dipole emission seems to be compatible with all the observations together. More stringent constraints of the AME polarisation at 10–40 GHz are necessary to disentangle between different models, to which future QUIJOTE data will contribute.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness (MINECO) under the projects AYA2007-68058-C03-01, AYA2010-21766-C03-02, AYA2012-39475-C02-01 and the Consolider-Ingenio project
CSD2010-00064 (EPI: Exploring the Physics of Inflation). CD acknowledges
support from an ERC Starting (Consolidator) Grant (no. 307209), SH from an STFC-funded studentship, and CHLC from the DIULS (Research Directorship of the University of La Serena).Peer Reviewe
Effect of mTORC1/mTORC2 inhibition on T cell function: potential role in graft-versus-host disease control
Producción CientíficaThe mechanistic target of rapamycin (mTOR) pathway is crucial for the activation and function of T cells, which play an essential role in the development of graft-versus-host disease (GvHD). Despite its partial ability to block mTOR pathway, the mTORC1 inhibitor rapamycin has shown encouraging results in the control of GvHD. Therefore, we considered that simultaneous targeting of both mTORC1 and mTORC2 complexes could exert a more potent inhibition of T cell activation and, thus, could have utility in GvHD control. To assess this assumption, we have used the dual mTORC1/mTORC2 inhibitors CC214-1 and CC214-2. In vitro studies confirmed the superior ability of CC214-1 versus rapamycin to block mTORC1
and mTORC2 activity and to reduce T cell proliferation. Both drugs induced a similar decrease in Th1/Th2 cytokine secretion, but CC214-1 was more efficient in inhibiting na€ıve T cell activation and the expression of Tcell activation markers. In addition, CC214-1 induced specific tolerance against alloantigens, while preserving anti-cytomegalovirus response. Finally, in a mouse model of GvHD, the administration of CC214-2 significantly improved mice survival and decreased GvHD-induced damages. In conclusion, the current study shows, for the first time, the immunosuppressive ability of CC214-1 on T lymphocytes and illustrates the role of CC214-2 in the allogeneic transplantation setting as a possible GvHD prophylaxis agent.Gerencia Regional de Salud de Castilla y León (Proyecto GRS 726/A13
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