Browsing by Issue Date, starting with "2024-06"
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- Chlorella vulgaris and Tetradesmus obliquus Protect Spinach (Spinacia oleracea L.) against Fusarium oxysporumPublication . Viana, Catarina; Genevace, Méanne; Gama, Florinda; Guerreiro David Coelho, Luísa Isabel; Pereira, Hugo; Varela, João; Reis, MárioChlorella vulgaris and Tetradesmus obliquus were tested as biocontrol agents against the phytopathogenic fungus Fusarium oxysporum. This evaluation was conducted through in vitro and in vivo trials with spinach (Spinacia oleracea L.). The in vitro trials showed that C. vulgaris and T. obliquus were able to inhibit the phytopathogen, showing a similar inhibitory effect to that of the positive controls (Rovral, BASF® and Biocontrol T34, Biocontrol Technologies® S.L.). C. vulgaris aqueous suspensions at 3.0 g L−1 led to a hyphal growth of 0.55 cm, each corresponding to a reduction of 63% of fungal growth. With T. obliquus, the hyphal growth was 0.53 cm when applied at a concentration of 0.75 g L−1, having an inhibition of fungus growth of 64%. Thereafter, these results were validated in an in vivo trial on spinach using the same controls. The results revealed a lower severity and disease incidence and a reduction in the disease’s AUDPC (area under the disease progress curve) when spinach was treated with the microalgae suspensions. Overall, these findings highlight the potential of C. vulgaris and T. obliquus suspensions as promising biocontrol agents against F. oxysporum in spinach when applied through irrigation.
- Deciphering the chemical constituents of phlomis monocephala extracts using UHPLC-HRMS and their antioxidant, neuroprotective, antidiabetic and toxic potentialsPublication . Zheleva-Dimitrova, Dimitrina; Zengin, Gokhan; Bouyahya, Abdelhakim; Ahmed, Shakeel; Guerreiro Pereira, Catarina Alexandra; Sharifi-Rad, Majid; Custódio, LuísaIn the current study, five different extracts ( n -hexane, ethyl acetate, dichloromethane, ethanol, and water) of Phlomis monocephala were analyzed for the first time by ultra -high-performance liquid chromatography -high resolution mass spectrometry (UHPLC-HRMS) to identify their phenolic compounds. The extracts were also evaluated for their non -enzyme antioxidant activities using a variety of methods, including DPPH and, ABTS center dot+ scavenging activities, reduction of ferric (Fe 3 + ), and cupric ions (Cu 2 + ), metal chelating (MCA) activities, and phosphomolybdenum (PBD). Additionally, the extracts were assessed for their in vitro enzyme inhibition potential (acetylcholinesterase (AChE)/butyrylcholinesterase (BChE), alpha-amylase, alpha-glucosidase, and tyrosinase). Furthermore, cell viability was evaluated on HepG2 (human hepatocellular carcinoma), S17 cells (murine bone marrow stromal) and RAW (murine macrophages). UHPLC-HRMS allowed for the identification of 115 compounds from different chemical groups including flavonoids, iridoid glycosides, phenylethanoid glycosides and others. Most of the extracts had strong antioxidant potential and were rich in phenolic compounds. Ethanol and water extracts appear as the most promising antioxidant extracts providing the highest values followed by ethyl acetate by all the methodologies employed in this study. Furthermore, all the extracts, except the aqueous extract, inhibited all the enzymes significantly. Surprisingly, the aqueous extract did not show a prominent inhibition (low or no inhibition) against these enzymes. Hexane, ethyl acetate, and dichloromethane exhibited extremely significant cytotoxic effects against all cell lines at a higher concentration. The HepG2 cells demonstrated lower sensitivity to the extracts than RAW and S17 cells. In conclusion, P. monocephala can be considered as a valuable ingredient for the production of functional applications including nutraceuticals.
- Global habitat predictions to inform spatiotemporal fisheries management: initial steps within the frameworkPublication . Bowlby, Heather D.; Druon, Jean-Noël; Lopez, Jon; Juan-Jordá, Maria José; Carreón-Zapiain, María Teresa; Vandeperre, Frederic; Leone, Agostino; Finucci, Brittany; Sabarros, Philippe S.; Block, Barbara A.; Arrizabalaga, Haritz; Afonso, Pedro; Musyl, Michael K.; Cortés, Enric; Cardoso, Luis Gustavo; Mourato, Bruno; Queiroz, Nuno; Fontes, Jorge; Abascal, Francisco J.; Zanzi, Antonella; Hazin, Humberto Gomes; Bach, Pascal; Sims, David W.; Travassos, Paulo; Coelho, RuiTuna Regional Fishery Management Organizations (tRFMOs) are increasingly interested in spatiotemporal management as a tool to reduce interaction rates with vulnerable species. We use blue shark ( Prionace glauca ) as a case study to demonstrate the critical first steps in the implementation process, highlighting how predictions of global habitat for vulnerable life stages can be transformed into a publicly -accessible spatial bycatch mitigation tool. By providing examples of possible management goals and an associated threshold to identify essential habitats, we show how these key areas can represent a relatively low percentage of oceanic area on a monthly basis (16-24% between 50 degrees S and 60 degrees N), yet can have relatively high potential protection efficiency (similar to 42%) for vulnerable stages if fishing effort is redistributed elsewhere. While spatiotemporal management has demonstrable potential for blue sharks to effectively mitigate fishing mortality on sensitive life stages, we identify inherent challenges and sequential steps that require careful consideration by tRFMOs as work proceeds. We also discuss how our single-species framework could be easily extended to a multispecies approach by assigning relative conservation risk before layering habitat model predictions in an integrated analysis. Such broader application of our approach could address the goals of tRFMOs related to reducing the ecosystem effects of fishing and pave the way for efficient fisheries co-management using an ecosystem-based approach.
- Quality-price choices and market configurations when location mattersPublication . Pires, Cesaltina Pacheco; Catalão-Lopes, Margarida; Jorge, Sílvia Ferreira; Garcês, PedroThis paper investigates how preexistent asymmetries in the way consumers value each firm's product influence quality-price decisions when consumers differ in quality valuation but incur a transportation cost when buying from the firm located on the periphery. We show that for a given location, the high-quality firm charges a higher price and that for given qualities, the firm located in the center charges higher prices. Regarding quality choices, we show that the firm located in the center may be able to behave as a partial coverage monopolist. Under duopoly, quality differentiation always exists, and in general, the high-quality firm may be located either in the center or on the periphery. Moreover, the qualities offered by both firms are higher when the high-quality firm is on the periphery, showing a substitutability effect between location and quality. Thus, incentivizing the high-quality firm to locate on the periphery improves overall market quality.
- Histological and scanning electron microscope observations on the developing retina of the cuttlefish (Sepia officinalis Linnaeus, 1758)Publication . Arias-Montecino, Alejandro; Álvarez-Hernán, Guadalupe; Mera-Rodríguez, José Antonio de; Calle-Guisado, Violeta; Martín-Partido, Gervasio; Rodríguez-León, Joaquín; Francisco-Morcillo, Javier; Sykes, AntónioIn this work we present a detailed study of the major events during retinal histogenesis of the cuttlefish Sepia officinalis from early embryos to newly hatched animals and juveniles. For this purpose, we carried out morphometric and histological analyses using light and scanning electron microscopy. From St19, the first embryonic stage analysed, to St23/24 the embryonic retina is composed of a pseudostratified epithelium showing abundant mitotic figures in the more internal surface. At St24 the first photoreceptor nuclei appear in the presumptive inner segment layer, while an incipient layer of apical processes of the future rhabdomeric layer become visible at St25. From this stage onwards, both the rhabdomeric layer and the inner segment layer increase in size until postnatal ages. In contrast, the width of the supporting cell layer progressively decreases from St25/26 until postnatal ages. S. officinalis embryos hatched in a morphologically advanced state, showing a differentiated retina even in the last stages of the embryonic period. However, features of immaturity are still observable in the retinal tissue during the first postnatal weeks of life, such as the existence of mitotic figures in the apical region of the supporting cell layer and migrating nuclei of differentiating photoreceptors crossing the basal membrane to reach their final location in the inner segment layer. Therefore, postnatal retinal neurogenesis is present in juvenile specimens of S. officinalis.
- Structural enrichment promotes natural behaviour and welfare of captive gilthead seabream broodstockPublication . Oliveira, Ana Rita; Cabrera-Álvarez, María José; Soares, Florbela; Diáz-Gil, Carlos; Candeias-Mendes, Ana; Saraiva, João; Arechavala-Lopez, PabloThe intensification of aquaculture practices in the last decade can compromise the welfare of farmed fish. However, one strategy to be considered to improve the welfare of captive fish is the implementation of structural enrichment in the rearing environment. The behavioural and physiological effects of suspended ropes inside rearing tanks were experimentally assessed on gilthead seabream (Sparus aurata) breeders, evaluating the potential use of such structures in production units. Over the course of six months, 60 adult gilthead seabreams, were reared in cylindrical tanks with and without structural enrichment. Fish were video recorded regularly before, during and after feeding. Biometry and blood samples for biochemical analyses of plasma (cortisol, glucose and lactate) were taken throughout the experiment. Suspended ropes modified the horizontal distribution of fish after feeding, influencing the swimming activity and social interactions throughout the experimental period. In addition, structural enrichment promoted foraging and anticipatory behaviour of gilthead seabream. No effects of structural enrichment were detected on gilthead seabream condition or growth, although there was an apparent positive yet fading effect of enrichment on plasma cortisol and glucose. In general, structural enrichment had diverse positive effects on the behaviour diversity and natural repertoire of captive gilthead seabream, and therefore, on fish welfare. This type of structural environmental enrichment can be easily incorporated into land-based flow-through and recirculating aquaculture systems, both for experimentation and commercial purposes.
- Navigating travel decisions in health crises: the interplay of message framing, regulatory focus, and perceived riskPublication . Saha, Prosanjit; Roy, Biplab; Ribeiro, Manuel AlectorThis study investigates the impact of promotional message framing on domestic tourists' travel intentions during a health crisis, exploring the moderating effects of regulatory focus and perceived risk. Utilizing a 2 x 2 x 2 between-subject factorial design, two experiments were conducted with data collected from domestic tourists. The findings reveal that promotion-focused tourists prefer emotionally resonant gain-framed messages with lower discounts and show lower susceptibility to health risks compared to their prevention-focused counterparts. The interaction of gain-framed messages with low discount depth resulted in increased travel intentions despite the health crisis. On the other hand, prevention-focused tourists exhibited no significant change in travel intentions in response to differently framed messages. This study extends the promotional framing literature by incorporating regulatory focus and risk perception, offering practical implications for the tourism industry, particularly during a time of health crisis.
- Anti-obesogenic effects of plant natural products: A focus on Korean traditional foodsPublication . Gitishree Das; Luis Alfonso Jiménez Ortega; J. Basilio Heredia; Maria de Lourdes Gomes Pereira; Han-Seung Shin; Jayanta Kumar Patra; Gonçalves, Sandra; Romano, AnabelaBackground Natural products from food can play an important role in obesity management. Korean traditional food (KTF), characterized by a high inclusion of fresh or prepared vegetables, a reasonable contribution of fish, pulses, and with very little amount of meat, is one of the most recognized cuisines for its nutritional quality, diversity, and flavor. The traditional Korean food contains relevant phytochemicals and probiotic microorganisms with anticancer, anti-mutagenic, antioxidant, and anti-obesogenic properties. Scope Obesity is a chronic degenerative pathology which causes adverse effects on health, low quality of life, and social costs. The use of fermentation as a conservation/preparation method increases the functional value of KTF, conferring new medicinal properties such as anti-obesogenic. Key findings and conclusions This review article summarizes data about the anti-obesogenic properties of phytochemicals and KTF. Reviewed results indicated that several phytochemicals present in KTF (e.g., flavonoids, saponins, terpenes) exerted anti-obesogenic effects due to their antioxidant, anti-inflammatory, inhibition of enzymes related to lipid and carbohydrate metabolism, inflection of lipid homeostasis, thermogenic, life cycle of adipocyte, and appetite suppression. Besides, both in vivo and medical research have showed that fermented products extensively included in KTF have a positive effect on the reduction of obesity through different mechanisms particularly by altering human metabolism and affecting gut microbiota. Some molecular mechanisms among these anti-obesogenic agents, are referred in research, focused on the search for phytochemicals that can intervene with leptin sensitizers, GLP1/glucagon dual agonists, GIP/GLP1/glucagon tri-agonists, amylin/calcitonin dual agonists, Y2R agonists, GIP/GLP1 dual agonists, drugs targeting the ghrelin pathway, and GLP1R agonists. Overall, the current review highlights the anti-obesogenic impact of KTF in accordance with the low rate of obesity in the Korean population.
- Mercury supply limits methylmercury production in paddy soilsPublication . Zhong, Huan; Su, Yao; Wu, Xinda; Nunes, Luís; Li, Chengjun; Hao, Yunyun; Liu, Yu-Rong; Tang, WenliThe neurotoxic methylmercury (MeHg) is a product of inorganic mercury (IHg) after microbial transformation. Yet it remains unclear whether microbial activity or IHg supply dominates Hg methylation in paddies, hotspots of MeHg formation. Here, we quantified the response of MeHg production to changes in microbial activity and Hg supply using 63 paddy soils under the common scenario of straw amendment, a globally prevalent agricultural practice. We demonstrate that the IHg supply is the limiting factor for Hg methylation in paddies. This is because IHg supply is generally low in soils and can largely be facilitated (by 336-747 %) by straw amendment. The generally high activities of sulfate-reducing bacteria (SRB) do not limit Hg methylation, even though SRB have been validated as the predominant microbial Hg methylators in paddies in this study. These findings caution against the mobilization of legacy Hg triggered by human activities and climate change, resulting in increased MeHg production and the subsequent flux of this potent neurotoxin to our dining tables.
- Spillover dynamics in DeFi, G7 banks, and equity markets during global crises: a TVP-VAR analysisPublication . Younis, Ijaz; Gupta, Himani; Du, Anna Min; Shah, Waheed Ullah; Hanif, WaqasDecentralized finance (DeFi) has become of significant interest for investors in both the financial and digital sectors. We use a time -varying parameter vector autoregression (TVP-VAR) approach to estimate the static and dynamic connections between and within DeFi, G7 banking, and equity markets. We focus on critical events such as the COVID-19 pandemic, the cryptocurrency bubble, and the Russia -Ukraine conflict. The results highlight interconnectedness and significant spillovers within and between the markets, especially during the COVID-19 pandemic. Notably, there were significant spillover effects from the G7 banking and equity markets to Japan and DeFi assets. The findings demonstrate a robust connection between DeFi platforms, G7 banking, and stock markets throughout these tumultuous periods. Policymakers, investors, and entrepreneurs are recommended to keep a close eye on changes in traditional banking and equity markets to adjust the risk of DeFi assets.