154 research outputs found
Combining landscape fire simulations with stand-level growth simulations to assist landowners in building wildfire-resilient landscapes
The wildfire regime in Portugal has been responsible for millions of hectares of burnt
area, and Alvares parish is no exception. In 2017, a severe wildfire burnt 60% of its area. Land
abandonment has been increasing since the mid 20th century, and a large fraction of the forest area
belongs to quasi-absent landowners. This has given rise to large, almost unbroken expanses of
undermanaged forests that, in combination with rugged topography, originates a landscape prone to
large, intense wildfires. Thus, a change in landscape composition and structure capable of reducing
flammability and promoting fuel discontinuity is urgently needed. A fire spread simulator and a
forest growth simulator were combined to show the impact of improving management at landscape
level. It was assumed that the probability of large wildfires may be reduced by setting aside forest
area for the implementation of a fuel break network (FBN) and increasing the area under sustainable
forest management. Three levels of management intensity were simulated by restricting the area of
Quasi-absent non-industrial owners to 34.5%, 20.1%, and 8.5% of the Alvares forest area, in favor
of increasing the area of active and semi-active non-industrial owners (current, moderate, and high
management scenarios). Different FBN extents, representing four levels of network implementation
priority were combined with the management levels, resulting in 12 scenarios. To evaluate the impact
of fire, simulations assuming no-fire, no-FBN, and current management intensity were performed,
whereas the impact of operation costs was assessed assuming reduced costs for silvicultural operations.
Per hectare simulations were then scaled up to the parish level and volume harvested and net
present values were used to compare the management improvement scenarios. Results showed that
fire has major repercussions on forest income, but these impacts can be minimized. Intensifying forest
management and implementing the first priority FBN segments originated substantial improvements
in financial outcome from timber production, close to those obtained for the full FBN implementation.
Results also evidenced contrasting contributions from industrial and non-industrial owners with the
later evidencing unbalanced cash-flows derailing the possibility for interesting forest incomes. The
coupling of fire and forest growth simulations can be an interesting approach to assess the impact of
different management and policy scenarios and inform policiesinfo:eu-repo/semantics/publishedVersio
The influence of ACE ID and ACTN3 R577X polymorphisms on lower-extremity function in older women in response to high-speed power training
Background
We studied the influence of the ACE I/D and ACTN3 R577X polymorphisms (single or combined) on lower-extremity function in older women in response to high-speed power training.
Methods
One hundred and thirty-nine healthy older Caucasian women participated in this study (age: 65.5 ± 8.2 years, body mass: 67.0 ± 10.0 kg and height: 1.57 ± 0.06 m). Walking speed (S10) performance and functional capacity assessed by the “get-up and go” (GUG) mobility test were measured at baseline (T1) and after a consecutive 12-week period of high-speed power training (40-75% of one repetition maximum in arm and leg extensor exercises; 3 sets 4–12 reps, and two power exercises for upper and lower extremity). Genomic DNA was extracted from blood samples, and genotyping analyses were performed by PCR methods. Genotype distributions between groups were compared by Chi-Square test and the gains in physical performance were analyzed by two-way, repeated-measures ANOVA.
Results
There were no significant differences between genotype groups in men or women for adjusted baseline phenotypes (P > 0.05). ACE I/D and ACTN3 polymorphisms showed a significant interaction genotype-training only in S10 (P = 0.012 and P = 0.044, respectively) and not in the GUG test (P = 0.311 and P = 0.477, respectively). Analyses of the combined effects between genotypes showed no other significant differences in all phenotypes (P < 0.05) at baseline. However, in response to high-speed power training, a significant interaction on walking speed (P = 0.048) was observed between the “power” (ACTN3 RR + RX & ACE DD) versus “non-power” muscularity-oriented genotypes (ACTN3 XX & ACE II + ID)].
Conclusions
Thus, ACE I/D and ACTN3 R577X polymorphisms are likely candidates in the modulation of exercise-related gait speed phenotype in older women but not a significant influence in mobility traits
Urinary levels of monohydroxyl PAH metabolites in portuguese firefighters: background levels and impact of tobacco smoke
Firefighting occupational exposure is classified as possible
carcinogen to humans by the International Agency for Research
on Cancer and the US National Institute for Occupational Safety
and Health [1,2].
Tobacco smoke is a very important factor in the assessment of
occupational exposure of workers, since the prolonged exposure
to tobacco smoke is by itself the major cause of lung cancer [3].
The consumption of tobacco is responsible for the exposure to
many smoke components including more than sixty known
carcinogens, including some polycyclic aromatic hydrocarbons
(PAHs) [4].
PAHs are ubiquitous compounds formed during pyrolysis or
incomplete combustion of organic matter, being well-known for
their toxic, mutagenic, and carcinogenic properties to humans
[5,6]. So far, the impact of tobacco smoke on firefighters’ total
exposure to PAHs is very limited.info:eu-repo/semantics/publishedVersio
Fluorinated surfactants in solution: Diffusion coefficients of fluorinated alcohols in water
Intra-diffusion coefficients of three
fluorinated alcohols, 2,2,3,3,3-pentafluoropropan-1-ol (PFP),
2,2,3,3,4,4,4-heptafluorobutan-1-ol (HFB) and 2,2,3,3,4,4,5,5,5-nonafluoropentan-1-ol (NFP) in water
have been measured by the PFG–NMR spin-echo technique as a function of temperature and
composition, focusing on the alcohol dilute region. For comparison, intra-diffusion coefficients of 2,2,2-
trifluoroethanol (TFE) and HFB have also been measured in heavy water using the same method and
conditions. As far as we know, these are the
first experimental measurements of this property for these
binary systems. Intra-diffusion coefficients for NFP in water and for TFE and HFB in heavy water have also
been obtained by molecular dynamics simulation, complementing those for TFE, PFP and HFB reported in
a previous work. The agreement between experimental and simulated results for PFP, HFB and NFP in
water is reasonable, although presenting higher deviations than for the TFE/water system. From the
dependence of the intra-diffusion coefficients on temperature, diffusion activation energies were
estimated for all the solutes in water and heavy water
Epidemia de dengue em Ribeirão Preto, SP, Brasil: nota prévia
A preliminary note on an outbreak of dengue which occurred in the city of Ribeirão Preto, State of S. Paulo, Brazil, from November 1990 to March 1991, is given. One case of Level n Dengue Hemorrhagic Fever/Dengue Shock Syndrome (DHF/DSS) and two deaths associated with dengue related shock are described. Clinicians and epidemiologists are alerted to the possibility of sporadic DHF/DSS cases during outbreaks of classical dengue in formerly free areas.Apresenta-se Nota preliminar de uma epidemia de dengue, ocorrida em Ribeirão Preto, São Paulo, Brasil, no período de novembro de 1990 a março de 1991. Descreve-se a ocorrência de um caso de "Dengue Hemorrhagic Fever/Dengue Shock Syndrome" Grau II (DHF/DSS) e de dois óbitos associados ao dengue devido a síndrome de choque. Alerta clínicos e epidemiologistas quanto à possibilidade de ocorrência de casos isolados de DHF/DSS durante epidemias de dengue clássico em áreas antes indenes à doença
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