The utilisation of seaweeds as feed supplements has been investigated for their potential to mitigate enteric methane emissions from ruminants. Enteric methane emissions are the primary source of ...direct greenhouse gas emissions in livestock and significantly contribute to anthropogenic methane emissions worldwide. The aim of the present study is to evaluate the nutritional role and the in vitro effect on cumulative gas and methane production of
(native species) and
(invasive species), two species of red algae from the Azorean Sea, as well as the ability to reduce biogas production when incubated with single pasture (
and
) as substrate. Four levels of concentrations marine algae were used (1.25%, 2.25%, 5%, and 10% DM) and added to the substrate to evaluate ruminal fermentation using the in vitro gas production technique. The total amount of gas and methane produced by the treatment incubation was recorded during 72 h of incubation. The results indicate that both algae species under investigation contain relatively high levels of protein (22.69% and 24.23%, respectively, for
and
) and significant amounts of minerals, namely magnesium (1.15% DM), sodium (8.6% DM), and iron (2851 ppm). Concerning in vitro ruminal fermentation, it was observed that
can reduce enteric methane production by approximately 86%, during the first 24 h when 5% is added. In the same period and at the same concentration,
reduced methane production by 34%. Thus, it can be concluded that
species from the Azorean Sea have high potential as a protein and mineral supplement, in addition to enabling a reduction in methane production from rumen fermentation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The worm Caenorhabditis elegans is a model system for studying many aspects of biology, including host responses to bacterial pathogens, but it is not known to support replication of any virus. ...Plants and insects encode multiple Dicer enzymes that recognize distinct precursors of small RNAs and may act cooperatively. However, it is not known whether the single Dicer of worms and mammals is able to initiate the small RNA-guided RNA interference (RNAi) antiviral immunity as occurs in plants and insects. Here we show complete replication of the Flock house virus (FHV) bipartite, plus-strand RNA genome in C. elegans. We show that FHV replication in C. elegans triggers potent antiviral silencing that requires RDE-1, an Argonaute protein essential for RNAi mediated by small interfering RNAs (siRNAs) but not by microRNAs. This immunity system is capable of rapid virus clearance in the absence of FHV B2 protein, which acts as a broad-spectrum RNAi inhibitor upstream of rde-1 by targeting the siRNA precursor. This work establishes a C. elegans model for genetic studies of animal virus-host interactions and indicates that mammals might use a siRNA pathway as an antiviral response.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study aimed to evaluate the nutritional potential of unconventional plants:
,
,
,
,
, and
, as an alternative roughage for ruminants. Chemical composition, gross energy, in vitro gas production, ...kinetics, and digestibility of dry matter and organic matter in vitro were determined for each species. The obtained results showed variations between the studied forages concerning crude protein, and the different fiber fractions: NDF, ADF, and ADL The
with a relative food value of 92.12%, showed a significant difference compared to the other species under study. After 96 h of incubation, the plants that produced, on average, less in vitro gas were
and
. Among the studied species,
stands out as the species that presented the highest gas production, with 31.53 mL. 200 mg
DM, observing a significant difference compared to the other plants. This is a reflection of it having the highest DMD (60.44 ± 1.22%) as well.
was the species with the longest colonization time (4.8 h). Among the plants studied, we highlight
as presenting a good quality in the RFV index and
as having good digestibility. Both can be used as roughage in periods of greater shortage of pastures.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Using invasive plants as non-conventional forage in livestock production can contribute to meeting climate change targets and provide a competitive advantage in a global market. This study evaluated ...the nutritional potential of several non-conventional plants: Pennisetum setaceum, Ricinus communis, Arundo donax, Acacia melanoxylon, Opuntia ficus-indica, Agave americana, Pittosporum undulatum, and Hedychium gardnerianum. Chemical composition, in vitro digestibility, gas production, and energy estimates were determined. Opuntia showed the lowest DM value (6.65%), while the highest was found for Acacia (39.43%). Ricinus recorded the highest levels of CP (23.56% DM), RFV (273.86), and in vitro gas production at 24 h (43.49 mL/200 mg DM). The highest NDF (80.39% DM), HEM (39.03% DM), and CEL (36.81% DM) values were observed for Pennisetum. Agave produced the highest amount of gas from the start to the end of incubation (22.68 to 48.99 mL/200 mg DM), while Acacia produced the least (3.83 to 14.78 mL/200 mg DM). The highest ME (8.72 MJ/kg DM) and NEL (5.06 MJ/kg DM) estimates were obtained for Agave. Correlations between the chemical compositions and feed quality indices of the plants were observed, showing strong negative correlations between ADF and DMD, OMD, and DMI (r > 0.86, p < 0.01). We can conclude that all these non-conventional plants have potential as an alternative feed for ruminants when there are fodder shortages.
Quantifying entericCH4 from grazing systems is a challenge for all regions of the world, especially when cattle feed mostly on pasture throughout the year, as pasture quality varies with the seasons. ...In this study, we examine the influence of seasonality on enteric methane emissions in the Azores, considering the most recent IPCC updates, to minimise errors in estimating enteric methane emissions in this region. For this purpose, samples of corn and grass silage, different types of concentrate, and pasture were collected throughout the year, and their nutritional value and digestibility were determined according to standard conventional methods. The estimation of methane production was conducted using the 2006 IPCC Tier 2 methodology, refined in 2019. The results revealed significant differences (p < 0.05) between the chemical composition of winter and summer pastures. However, it was in the autumn that these pastures presented the best nutritional quality. We estimated that the total volume of enteric methane produced in the Azores was 20,341 t CH4, with peak enteric methane emissions (5837 t CH4) reached during the summer. Breeding bulls, beef cows, and heifers are the categories that produce the highest amount of methane per animal. However, if we consider the total number of animals existing in the region, pregnant dairy cows are the category of cattle with the highest emissions of CH4. Thus, considering the current system of cattle production in the region, we can infer that the pastures are better managed during the autumn, which translates into lower emissions of enteric methane into the atmosphere during this season.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Using invasive plants in animal production can provide an economical and eco-sustainable competitive advantage in a globalized market. The
and the
L. are invasive plants historically used by Azorean ...farmers as an alternative ruminant water source in the summer. This study aims to better understand their properties and how they vary throughout the year, so their use to complement animal diets can be optimised. Six samples of each species were collected on the Terceira Island during 2 growth seasons: winter (January 2021) and summer (September 2021), and their chemical composition, in vitro digestibility, and gas production, were determined. Significant (
< 0.05) differences were found in all parameters between the summer and the winter, with larger variations in both fibre (NDF and ADF) and digestibility parameters found between the
and the
. Gas production was greater in the summer for
and in the winter for
. Even though the digestibility was lower in the summer, we found that both plants offer a viable ruminant feed complement in both seasons, providing a cheap and eco-sustainable alternative water source, that can be associated to dry forage and compound feeding stuff with a high crude protein content when designing ruminant diets.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
This work aimed to determine and compare the effect of elevation and season on the productivity and the nutritive value of pastures in the Azores (Terceira Island). Forage was collected and analysed ...for dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), ether extract (EE), mineral ash (Ash), dry matter digestibility (DMD) and organic matter digestibility (OMD). The net productivity (NP) was higher in the low elevation pasture A (1.80 g m−2), lower in pasture B (0.98 g m−2) and peaked in the winter in both pastures A (3.57 g m−2) and B (2.33 g m−2) and during the summer in the high elevation pasture C (2.15 g m−2). The soil chemical proprieties varied significantly among the three pastures. The highest soil pH, available P, K, Ca and Mg were recorded in pasture A. Positive correlations were observed between all soil parameters analysed and NP, except for the OM content. The DM, PB and EE changed significantly with elevation, while all nutritive parameters (except CP, EE and Ash) increased significantly along the growth season. Environmental factors influenced the nutritive parameters and productivity, suggesting that climate change might have significant impacts on forage production and quality.
A spontaneous mutation affecting locomotion of the nematode Caenorhabditis elegans has been mapped to a new gene, unc-119. Phenotypic characterization of the mutants suggests the defect does not lie ...in the musculature and that the animals also have defects in feeding behavior and chemosensation. unc-119 has been physically mapped relative to a previously identified chromosomal break in linkage group III, and DNA clones covering the region can rescue the mutant phenotype in transgenic animals. Three more alleles at the locus, with identical phenotypes, have been induced and characterized, all of which are putative null alleles. The predicted UNC-119 protein has no significant similarity to other known proteins. Expression of an unc-119/lacZ fusion in transgenic animals is seen in many neurons, suggesting that the unc-119 mutant phenotype is due to a defect in the nervous system.
Shell-and-tube type heat exchangers (STHE) are the most important part of non-combustion heat transfer equipment in industrial processes. The literature provides extensive information on various ...methods of optimizing the design of STHE, however, as a rule, it is carried out only with the aim of minimizing costs as an objective function. In this paper, it is proposed to use multi-purpose optimization of STHE using new thermodynamic and environmental expressions as objective functions. Its implementation is possible with the use of genetic algorithms of the second generation. The paper presents a procedure and a mathematical model for multi-purpose optimization, in which five objective functions are proposed to be used: the coefficient of thermal resistance, thermal efficiency, environmental function, total cost, including operating costs, and the total amount of dissipated entransy. The concept of entransy is proposed for the first time to create a new ecological function used as a criterion for optimizing STHE. The novelty of the proposed work lies in the fact that it optimizes simultaneously taking into account mechanical and vibration limitations, the design of the heat exchanger, as well as taking into account the parameters of thermohydraulic processes occurring in it. The approbation of the methodology was carried out on the basis of a specific case study, which had previously been repeatedly used by various authors to verify the results obtained. The multi-purpose optimization of the STHE made it possible to develop design options with minimal costs at a given thermal load and with geometric options that are adaptable to the space available for installation and the availability of auxiliary systems.
Liquid–liquid equilibrium data for the ternary systems nonane
+
benzene
+
bmimPF
6, nonane
+
toluene
+
bmimPF
6, nonane
+
m-xylene
+
bmimPF
6, undecane
+
benzene
+
bmimPF
6, undecane
+
toluene
+
...bmimPF
6, undecane
+
m-xylene
+
bmimPF
6) were determined at 298.15
K. Binodal curves were obtained by the cloud point method, while tie-line compositions were obtained by density and UV spectrophotometry measurements. In all cases the two-phase region is large and wide. The values of distribution coefficients and selectivities indicate that the ionic liquid bmimPF
6 is a good solvent for the extraction of aromatic from aliphatic compounds. The consistency of the tie-line data was ascertained by applying the Othmer–Tobias correlation. The experimental LLE data were correlated through the well-known NRTL model for the activity coefficient, with estimation of new interaction energy parameters, using the Simplex minimization method and a composition-based objective function. The results, analyzed in terms of root mean square deviations between experimental and calculated compositions, were considered satisfactory.
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