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Insights on beer volatile profile: optimization of solid-phase microextraction procedure taking advantage of the comprehensive two-dimensional gas chromatography structured separation
No full textThe aroma profile of beer is crucial for its quality and consumer acceptance, which ismodulated
by a network of variables. The main goal of this study was to optimize solid-phase
microextraction experimental parameters (fiber coating, extraction temperature, and time),
taking advantage of the comprehensive two-dimensional gas chromatography structured
separation. As far as we know, it is the first time that this approach was used to
the untargeted and comprehensive study of the beer volatile profile. Decarbonation
is a critical sample preparation step, and two conditions were tested: static and under
ultrasonic treatment, and the static condition was selected. Considering the conditions
that promoted the highest extraction efficiency, the following parameters were
selected: poly(dimethylsiloxane)/divinylbenzene fiber coating, at 40ºC, using 10 min of
pre-equilibrium followed by 30 min of extraction. Around 700–800 compounds per sample
were detected, corresponding to the beer volatile profile. An exploratory application was performed
with commercial beers, using a set of 32 compounds with reported impact on beer
aroma, in which different patterns can be observed through the structured chromatogram.
In summary, the obtained results emphasize the potential of this methodology to allow an
in-depth study of volatile molecular composition of beer
The effect of data analysis strategies in density estimation of mountain ungulates using distance sampling
No full textDistance sampling is being extensively used to estimate the abundance of animal populations. Nevertheless, the great variety
of ways in which data can be analyzed may limit comparisons due to the lack of standardization of such protocols. In this
study, the influence of analytical procedures for distance sampling data on density estimates and their precision was
assessed. We have used data from 21 surveys of mountain ungulates in the Iberian Peninsula, France and the Italian
Alps. Data from such surveys were analyzed with the program Distance 6.0. Our analyses show that estimated density can be
higher for higher levels of data truncation. We also confirm that the estimates tend to be more precise when data are
analyzed without binning and without truncating. We found no evidence of size biased sampling as group size and distances
were uncorrelated in most of our surveys. Despite distance sampling being a fairly robust methodology, it can be sensitive to
some data analysis strategies
Thermo-desorption: a valid tool for mercury speciation in soils and sediments?
No full textMercury (Hg) speciation by thermo-desorption is considered an alternative to laborious sequential chemical procedures;
hence its popularity has increased in the last years. In thiswork, steps were taken to improve the information
obtained by Hg speciation through thermo-desorption, specifically to improve peak resolution and
increase the number of species that can be identified. The thermo-desorption behavior ofHg bound to iron oxides
was characterized, as well as a new Hg–humic acid synthetic standard material. In contrast to previous studies,
the peak corresponding to the Hg fraction associated with humic acids was clearly separated from the mineral
fraction, and identified in some natural samples. With increasing temperature, Hg species are released in the
following order: HgCl2 = Hg associated with Fe2O3 b Hg associated with humic acids b HgS b HgO, with an
overlap of HgCl2 and Hg associated with iron oxides.
An evaluation of the effects of sample pre-treatment and storage on Hg speciation was also performed. It was
found that sieving to b2 mm improved the sample homogeneity. The importance of fast sample analysis was
highlighted, given that after 10 days of storage at room temperature, volatile Hg0 could no longer be identified
in the sample. The suitability of thermo-desorption for mercury speciation in soils and sediments is discussed
Intrastrain genomic and phenotypic variability of the commercial Saccharomyces cerevisiae strain Zymaflore VL1 reveals microevolutionary adaptation to vineyard environments
No full textThe maintenance of microbial species in different environmental conditions is associated with adaptive microevolutionary
changes that are shown here to occur within the descendants of the same strain in comparison with the commercial
reference strain. However, scarce information is available regarding changes that occur among strain descendants during
their persistence in nature. Herein we evaluate genome variations among four isolates of the commercial winemaking
strain Saccharomyces cerevisiae Zymaflore VL1 that were re-isolated from vineyards surrounding wineries where this strain
was applied during several years, in comparison with the commercial reference strain. Comparative genome hybridization
showed amplification of 14 genes among the recovered isolates being related with mitosis, meiosis, lysine biosynthesis,
galactose and asparagine catabolism, besides 9 Ty elements. The occurrence of microevolutionary changes was supported
by DNA sequencing that revealed 339–427 SNPs and 12–62 indels. Phenotypic screening and metabolic profiles also
distinguished the recovered isolates from the reference strain. We herein show that the transition from nutrient-rich musts
to nutritionally scarce natural environments induces adaptive responses and microevolutionary changes promoted by Ty
elements and by nucleotide polymorphisms that were not detected in the reference strain
New insights towards the establishment of phycocyanin concentration thresholds considering species-specific variability of bloom-forming cyanobacteria
No full textIn vivo phycocyanin (PC) fluorescence
allows assessing cyanobacterial abundance in an easy,
fast and cost-effective way. However, the establishment
of PC thresholds is necessary for its use in
routine monitoring programmes and there has been no
consensus regarding their definition. This work aimed:
(1) to assess the potential species-specific variation in
fluorometric PC content among Microcystis aeruginosa,
Nostoc muscorum and Cylindrospermopsis
raciborskii; (2) to propose specific PC thresholds
based on World Health Organization alert levels; and
(3) to evaluate the in vivo PC signal reliability to
interferences from massive algal growth and mixtures
of bloom-forming cyanobacteria. Strong linear relationships
were recorded between PC and cell counts,
biovolume and chlorophyll a. However, a significant
species-specific variation in PC was observed using
cell counts. Increased microalgal densities did not
cause significant interference of PC signals. Also, dual
mixtures of cyanobacteria revealed strong relationships
between measured and expected PC content.
Results suggest that fluorometric PC is a good
predictor for cyanobacterial biomass but cell number
is not the best parameter to define thresholds. Biovolume
should be used instead. Nevertheless, speciesspecific
thresholds must be considered, rather than a
general cyanobacterial threshold
Size-segregated particulate matter and gaseous emissions from motor vehicles in a road tunnel
No full textIn order to address road traffic emissions, studies need to be performed under realistic driving
conditionswhere the input fromother sources isminimised.Measurements in traffic tunnels have
been used for quantifying emissions, but so far no study has established emission factors (EFs) for
Southern Europe. To fill this gap, a sampling campaign was carried out for one week in the
Liberdade Avenue tunnel (Braga, Portugal). The campaign included the monitoring of gaseous
pollutants (CO2, CO, NOx) and suspended particulate matter (PM) at two sites, one in the tunnel
and another in an urban background location. Organic and elemental carbon (OC and EC) in sizesegregated
particles (PM0.5, PM0.5–1, PM1–2.5 and PM2.5–10) were determined by a thermal–optical
system, whereas major and trace elements were analysed by ICP-MS and ICP-AES. PM0.5
accounted for 56% of the PM10 mass, while PM2.5–10 represented only 12%. The carbonaceous
fraction was concentrated in PM0.5, encompassing 88% of the EC and 67% of the OC present in
PM10. Elements attributable to non-exhaust emissions could be divided into two groups. Fe, Ba,
Cu, Sb, Sn and Zn, fromtyre and brakewear,weremore abundant in particles between 1 and 2 μm.
Ca, Al, K, Sr and Ti, associated with soil resuspension,weremainly present in particles N2 μm. The
average EFs of CO, CO2 and NOxwere 212, 4.02 and 1.22 g veh−1 km−1, respectively, while values
of 152 mg PM10 veh−1 km−1 and 133 mg PM2.5 veh−1 km−1 were obtained for the particles. OC
and EC emission factor was 39 mg veh−1 km−1 for PM10. The corresponding OC and EC values for
PM2.5 were 34 and 38 mg veh−1 km−1. The EFs are slightly lower than those found for other
tunnels, but within the ranges presented by the EMEP/EEA inventory
Monitorização de curto prazo da praia de Maceda
No full textMestrado em Ciências das Zonas CosteirasA praia de Maceda insere-se numa zona costeira aberta e de natureza arenosa, cuja a formação
remonta ao período de construção da restinga arenosa que, do Séc. X ao Séc. XV progrediu
até à localização actual de S. Jacinto. Esta costa tem sofrido variações sigdicativas ao longo
da segunda metade do século XX. A linha de costa tem sofiido modificações em resultado da
aceleração do processo erosivo que por sua vez está relacionado com a subida do nível do mar
(o qual amplia o efeito temporais), enfraquecimento sediientar da deriva litoral e intervenções
antropicas.
Desta forma toma-se importante conhecer as variações sofridas pela praia e pela linha de costa
a fun de caracterizar a morfodinâmica da praia e determinar as zonas dde maior
vulnerabiidade aos efeitos dos temporais.
Para tal procedeu-se a uma caracterização morfológica e sedimentológica que se baseou no
estudo de perfis transversais a linha de costa e na análise granulométrica das areias.
No período de monitorização foram registados recuos que não são representativos daqueles
que tiveram lugar nos anos imediatamente anteriores. Este facto poderá ser justificado com um
incremento do transporte de sedimentos via deriva relacionada com a ocorrência de fortes
cheias no período imediatamente anterior ao início do trabalho de monitorização. A
justificação liga-se ainda às condições de agitação marítima amenas durante o período em que
se desenvolveu o trabalho.
Foi ainda determinado o recuo provável da linha de costa face a um temporal com um período
de retomo inferior a 10 anos tendo-se concluído que os locais imediatamente a sul do esporão
e os locais afastados 1Km para sul deste seriam alvo de fortes recuos.
A monitorização das praias aíigura-se como um importante instrumento de trabalho ao
permitir prever e quantificar a acção dos temporais na lia de costa. Desta forma será possível
estabelecer as zonas de maior fragilidade cujo conhecimento é de uma utilidade indiscutível na
optimização dos programas de conservação e protecção das zonas costeiras
Las relaciones sobre el estado de la Archidiócesis de Granada: dos documentos de la visita ad limina de 1595
No full textLos obispos de todo el mundo católico están obligados a presentar ante el Papa un informe sobre el estado, tanto material como espiritual, de sus respectivas diócesis. Dicho informe o relación se presenta en el transcurso de una visita ad limina Apostolorum Petri et Pauli, es decir, una visita para venerar sus tumbas, que actualmente se realiza cada cinco anos, pero cuya periodicidad ha ido variando con el paso del tiempo. Se encuentran estas relaciones en el Archivio Segreto Vaticano, agrupadas en la serie S. (acrae) Congr. (egationis) Concilii Relationes. Las de la archidiócesis granadina se hallan en las cajas 370 A y 370 B. En el presente trabajo presento una transcripción de dos documentos que acompanan la primera relación de Granada, la de 1595, junto con su traducción, algunas notas históricas y un comentaio de la lengua empleada, a través del cual se puede apreciar tanto la evolución dei latín eclesiástico a fínales del s. XVI como el grado de conocimiento de la lengua latina que poseían los escribas de esta época.Every bishop in the Catholic Church has the duty ofinforming the Pope about the situation of his diocese. The report is given during a visit ad limina Apostolorum Petri et Pauli, i. e., in order to venerate their graves. This visit, at present, takes place every five years, but its periodicity has been varied according to the different times. The reports are placed in the Archivio Segreto Vaticano, grouped under the series S. (acrae)
Congr. (egationis) Concilii Relationes. The ones of the diocese of Granada are in the boxes 370 A and 370 B. In this work I have presented the transcription of two documents
attached to the first report of Granada, dated in 1595. Further more, I have given its
translation, some historical footnotes and a comentary on the language used. Through this
comentary an evolution of ecclesiastic Latin in the final of the 16th century and the that
time scribes' degree of knowledge of Latin are noticed
Granite emplacement at the termination of a major Variscan transcurrent shear zone: the late collisional Viseu batholith
No full textA major event of plutonic activity occurred all across the Central Iberian Zone of the Iberian Variscan Belt at the end of Late Paleozoic Variscan collisional tectonism. The present study focuses on the western sector of the Viseu late-post-tectonic batholith (central Portugal), a large composite intrusion comprising three main plutonic units: (a) small bodies of mafic to intermediate composition preferentially concentrated along the northern border, (b) a wide ring of coarse porphyritic biotite monzogranite (Cota-Viseu granite) and (c) a more evolved medium porphyritic, biotite-muscovite monzogranite occupying the central part of the intrusion (Alcafache granite).
The compositional zonation pattern of the whole batholith and the complex mixing/mingling relationships between the voluminous Cota-Viseu porphyritic granite and the mafic/intermediate rocks suggest that these melts were withdrawn from a lower crustal source region undergoing partial melting, invasion by mantle-derived mafic magmas, mixing and fractional crystallization. New CA-ID-TIMS U-Pb zircon ages indicate that pluton assembly via multipulse injection of successive magma batches took place between 299.4 ± 0.4 Ma and 296.0 ± 0.6 Ma.
A detailed anisotropy of magnetic susceptibility (AMS) survey suggests that pluton emplacement occurred at the extensional termination of a regional-scale, ENE-WSW trending, sinistral D3 shear zone - the Juzbado-Penalva Shear Zone (JPSZ). A dilational opening model involving the development of “en-échelon” tensional gashes at the extensional termination of the fault, followed by progressive opening and widening of north-south trending fractures, provided the space into which the successive magma batches arriving from below were emplaced. Vertical inflation was accommodated by depression of the pluton floor. The proposed model is consistent with the asymmetric wedge-shaped geometry of the intrusion (steep root zone on the northern side, discordant subvertical walls and a shallowing pluton floor towards the south)
Entre la retórica y la poética: el "De poeta" de Antonio Sebastiano Minturno
No full textEn este texto se intenta demostrar que la intención consciente de Minturno era competir con cicerón (de ahí la confrontación de los títulos) y mostrar que la retórica se encontraba subordinada a la poética. Es decir, si Minturno no evita en ningún momento, y hasta potencia, el cotejo teórico entre las dos disciplinas, utilizando repetidamente presupuestos de la ciencia oratoria, no es por ignorar las especificidades del arte de la poesía, sino para demostrar incontestablemente la superioridad de esta, que abarca tanto a la retórica como a la filosofía