82 research outputs found
Owls (Strigiformes) in Parque Nacional Peneda-Gerês (PNPG) – Portugal
Owls (Strigiformes) are particularly difficult to study and the existing information is still scarce. In PNPG
area there are records of the seven species present in Portugal; the Long-eared Owl and the Short-eared Owl are
here occasional species. This work aims to determine the distribution, density and abundance of Strigiformes in
PNPG (Northwest of Portugal). Between December 2007 and June 2008, 106 passive hearing point counts of
15 minutes each were done in the centre of each of 106 squares (2x2 km). Distribution maps for each species
were obtained. Therefore, we recorded a total of 98 contacts for Tawny Owl and 67 contacts for Scops Owl.
We also obtained 7 contacts of Little Owl, 2 contacts of Barn Owl and one of Eagle Owl. The habitat selection
by Scops Owl and Tawny Owl was also studied. Scops Owls seems to avoid low shrub and preferred forested
areas. Tawny Owls also avoid low shrub areas, preferring forested areas, and were found in urban areas. The
populations of these two species in PNPG show a considerable expansion, while the other ones reveal a marked
decline regarding the previous situation. The implementation of monitoring and conservation measures is suggested
to stop the decline of these three species
Trends in Mesenchymal Stem Cells\u27 Applications for Skeletal Muscle Repair and Regeneration
Skeletal muscle injuries are quite frequent in traumatic scenarios, such as war injuries or road- or work-related accidents. The skeletal muscle has good regenerative ability, but the extent or recurrence of muscle injury might impair complete structural and functional recovery. Severe tissue loss overwhelms skeletal muscle´s intrinsic regenerative capabilities and culminates in the development of noncontractile fibrous tissue scar. Conservative RICE -based and surgical treatments show limited efficacy in terms of improving these severe cases outcomes, pressing the need for new approaches on skeletal muscle’s therapy. Since the first suggestions of the potential of mesenchymal stem cells for regenerative medicine and tissue engineering, many applications have been explored for a variety of tissues and diseases, including the skeletal muscle, which is the focus of this literature review
Heuristic Segmentation of a Nonstationary Time Series
Many phenomena, both natural and human-influenced, give rise to signals whose
statistical properties change under time translation, i.e., are nonstationary.
For some practical purposes, a nonstationary time series can be seen as a
concatenation of stationary segments. Using a segmentation algorithm, it has
been reported that for heart beat data and Internet traffic fluctuations--the
distribution of durations of these stationary segments decays with a power law
tail. A potential technical difficulty that has not been thoroughly
investigated is that a nonstationary time series with a (scale-free) power law
distribution of stationary segments is harder to segment than other
nonstationary time series because of the wider range of possible segment sizes.
Here, we investigate the validity of a heuristic segmentation algorithm
recently proposed by Bernaola-Galvan et al. by systematically analyzing
surrogate time series with different statistical properties. We find that if a
given nonstationary time series has stationary periods whose size is
distributed as a power law, the algorithm can split the time series into a set
of stationary segments with the correct statistical properties. We also find
that the estimated power law exponent of the distribution of stationary-segment
sizes is affected by (i) the minimum segment size, and (ii) the ratio of the
standard deviation of the mean values of the segments, and the standard
deviation of the fluctuations within a segment. Furthermore, we determine that
the performance of the algorithm is generally not affected by uncorrelated
noise spikes or by weak long-range temporal correlations of the fluctuations
within segments.Comment: 23 pages, 14 figure
Undamning the Douro river catchment: a stepwise approach for prioritizing dam removal
Dams provide water supply, flood protection, and hydropower generation benefits, but
also harm native species by altering the natural flow regime, and degrading the aquatic and riparian
habitats. In the present study, which comprised the Douro River basin located in the North of
Portugal, the cost-benefit assessment of dams was based upon a balance between the touristic
benefits of a dammed Douro, and the ecological benefits of less fragmented Douro sub-catchments.
Focused on four sub-catchments (Sabor, Tâmega, Côa and Corgo), a probabilistic stream connectivity
model was developed and implemented to recommend priorities for dam removal, where this action
could significantly improve the movement of potadromous fish species along the local streams.
The proposed model accounts for fish movement across the dam or weir (permeability), which
is a novel issue in connectivity models. However, before any final recommendation on the fate
of a dam or weir, the connectivity results will be balanced with other important socio-economic
interests. While implementing the connectivity model, an inventory of barriers (dams and weirs)
was accomplished through an observation of satellite images. Besides identification and location of
any obstacles, the inventory comprised the compilation of data on surrounding land use, reservoir
water use, characteristics of the riparian gallery, and permeability conditions for fish, among others.
All this information was stored in a geospatial dataset that also included geographical information
on the sub-catchment drainage network. The linear (drainage network) and point (barriers) source
data were processed in a computer program that provided or returned numbers for inter-barrier
stream lengths (habitat), and the barrier permeability. These numbers were finally used in the
same computer program to calculate a habitat connector index, and a link improvement index,
used to prioritize dam removal based upon structural connectivity criteria. The results showed
that habitat patch connectivity in the Sabor, Tâmega and Côa sub-catchments is not dramatically
affected by the installed obstacles, because most link improvement values were generally low. For the
opposite reason, in the Corgo sub-catchment, obstacles may constitute a relatively higher limitation
to connectivity, and in this case the removal of eight obstacles could significantly improve this
connectivity. Using the probabilistic model of structural connectivity, it was possible to elaborate
a preliminary selection of dams/weirs that critically limit stream connectivity, and that will be the
focus of field hydraulic characterization to precisely determine fish movement along the associated
river stretches. Future work will also include the implementation of a multi-criteria decision support
system for dam removal or mitigation of the critical structures, as well to define exclusion areas for
additional obstaclesinfo:eu-repo/semantics/publishedVersio
Essential oil composition and antioxidant and antimicrobial properties of Campomanesia pubescens O. Berg, Native of Brazilian Cerrado
In this study, the essential oil composition, total contents of phenolics and proanthocyanidins, antioxidant and antimicrobial activities from different plant parts (root, stem, leaf and fruit) of Campomanesia pubescens (DC) O. Berg from Brazilian Cerrado are reported. The root essential oil is distinguished from others by having only one representative of monoterpenes (alpha-terpenylacetate). The aerial parts of C. pubescens are rich in volatile terpenes, as expected, especially in fruits whose essential oil contained approximately 80 % of monoterpenes. The essential oils showed antimicrobial activity against oral pathogens. The root essential oil showed the strongest inhibition against Fusobacterium nucleatum (ATCC 25586). The leaf extract presented the highest concentration of phenolic and proanthocyanidins compounds. The lowest concentration necessary for inhibition of DPPH to 50 % ranged between 6.6 ± 1.6 and 56.6 ± 2.3 μg/mL. The leaf extract exhibited the highest inhibition, close to BHT.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Evapotranspiração do feijoeiro irrigado em plantio direto sobre diferentes palhadas de culturas de cobertura
Desempenho de híbridos de milho com ciclos contrastantes em função da desfolha e da população de plantas
Avaliação do uso de fertilizantes organominerais e químicos na fertirrigação do cafeeiro irrigado por gotejamento
- …