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Entomological indicators of?Plasmodium species transmission in?Goma Ts?-Ts? and?Madibou districts, in?the?Republic of?Congo
No full textMalaria remains a major public health problem in the Republic of Congo, with Plasmodium falciparum being the deadliest species of Plasmodium in humans. Vector transmission of malaria is poorly studied in the country and no previous report compared rural and urban data. This study aimed to determine the Anopheles fauna and the entomological indices of malaria transmission in the rural and urban areas in the south of Brazzaville, and beyond. Indoor household mosquitoes capture using electric aspirator was performed in rural and urban areas
during raining and dry seasons in 2021. The identification o Anopheles species was done using binocular magnifier and nested?PCR. TaqMan and nested?PCR were used to detect the Plasmodium species in the head/thorax and abdo? mens of Anopheles. Some entomological indices including the sporozoite infection rate, the entomological inoculation rate and the man biting rate were estimated. A total of 699 Anopheles mosquitoes were collected: Anopheles gambiae sensu lato (s.l.) (90.7%), Anopheles funestus s.l. (6.9%), and Anopheles moucheti (2.4%). Three species of An. gambiae s.l. were identified includin Anoph- eles gambiae sensu stricto (78.9%), Anopheles coluzzii (15.4%) and Anopheles arabiensis (5.7%). The overall sporozoite infection rate was 22.3% with a predominance of Plasmodium falciparum, followed by Plasmodium malariae and Plas- modium ovale. Anopheles aggressiveness rate was higher in households from rural area (1.1 bites/night) compared to that from urban area (0.8 ib/p/n). The overall entomological inoculation rate was 0.13 ib/p/n. This index was 0.17 ib/p/n and 0.092 ib/p/n in rural and in urban area, respectively, and was similar during the dry (0.18 ib/p/n) and rainy (0.14 ib/p/n) seasons
Editorial: True limpets as living resources - biology, ecology, exploitation and sustainability
No full textTrue limpets (Patellogastropoda Lindberg, 1986) constitute a globally distributed and prominent group of marine gastropods, inhabiting environments ranging from rocky seashores to abyssal depths. Their scienti?c signi?cance lies in their evolutionary status as basal gastropods, adaptive strategies for survival in challenging conditions, and their role as a dominant group in?uencing biological communities on rocky substrata (Lindberg, 2008; Henriques et al., 2017). Limpets play a pivotal role as keystone grazers in?uencing the macro-algal vegetation on rocky shores (Hawkins and Hartnoll, 1983; Jenkins et al., 2005; Coleman et al., 2006), exerting seasonal top-down control on microbial ?lms (Thompson et al., 2004) and are crucial to local algal patchiness (Johnson et al., 1997; Burrows and Hawkins, 1998; Johnson et al., 1998). Limpets also have been exploited since the Pleistocene (Marean et al., 2007). Currently, limpets support various human activities such as food consumption, ornamentation, and as ?shing bait (Firth, 2021). In this context, over exploitation coupled with other anthropogenic disturbances has led to increased sustainability risks for numerous limpet population
Long-Term Spatiotemporal Characteristics of Ulva prolifera Green Tide and Effects of Environmental Drivers on Its Monitoring by Satellites: A Case Study in the Yellow Sea, China, from 2008 to 2023
No full textUlva prolifera (U. prolifera) green tide outbreaks have occurred in the Yellow Sea of China
for many years, causing serious losses to marine ecology and the marine economy. The monitoring
and tracking of U. prolifera green tide is a crucial aspect of marine ecological disaster prevention
and control management. This paper aims to investigate the spatiotemporal distribution changes
in U. prolifera green tide in the Yellow Sea throughout its life cycle. A survey of the Yellow Sea
from 2008 to 2023 was conducted using multi-source remote sensing images. Long-term monitoring
and analysis of U. prolifera revealed the evolution process of the green tide, including the early
development, outbreak, decline, and extinction stages, considering time, space, and frequency of
occurrence. Additionally, this study examined peak coverage change patterns over the past 16 years
and analyzed the influence of environmental factors such as sea surface temperature and sea surface
wind field on the development of U. prolifera. The research results serve as a valuable reference for
the monitoring, early warning, and scientific prevention and control of U. prolifera green tide in the
Yellow Sea, as well as other similar marine disaster areas
Chemical and Antioxidant Properties of Solvent and Enzyme-Assisted Extracts of Fucus vesiculosus and Porphyra dioica Paulo Nova 1,2 , Sara A. Cunha 1
No full textExtraction strategies impact the efficiency and nature of extracted compounds. This
work assessed the chemical composition and antioxidant capacity of ethanolic, hydroethanolic, and
aqueous versus enzyme-assisted extracts (isolated or with the sequential use of alcalase?, cellulase?,
and viscozyme?) of the macroalgae Fucus vesiculosus (brown, Phaeophyceae) and Porphyra dioica (red,
Rhodophyta. For both macroalgae, enzyme-assisted extraction (EAE) was the most efficient process
compared to solvent-assisted extraction (SAE), independent of solvent. Fucus vesiculosus extraction
yields were higher for EAE than for SAE (27.4% to 32.2% and 8.2% to 30.0%, respectively). Total
phenolics content (TPC) was at least 10-fold higher in EAE extracts (229.2 to 311.3 GAE/gextract) than
in SAE (4.34 to 19.6 GAE/gextract) counterparts and correlated well with antioxidant capacity (ABTS
and ORAC methods), with EAE achieving values up to 8- and 2.6-fold higher than those achieved by
SAE, respectively. Porphyra dioica followed F. vesiculosus?s trend for extraction yields (37.5% to 51.6%
for EAE and 5.7% to 35.1% for SAE), TPC, although of a lower magnitude, (0.77 to 8.95 GAE/gextract
for SE and 9.37 to 14.73 GAE/gextract for EAE), and antioxidant capacity. Aqueous extracts registered
the highest DPPH values for both macroalgae, with 2.3 ?mol TE/gextract and 13.3 ?mol TE/gextract
for F. vesiculosus and P. dioica, respectively. EAE was a more efficient process in the extraction of
soluble protein and reducing sugars in comparison to SAE. Furthermore, an improved effect of
enzyme-assisted combinations was observed for almost all analyzed parameters. This study shows
the promising application of enzyme-assisted extraction for the extraction of valuable compounds
from F. vesiculosus and P.dioica, making them excellent functional ingredients for a wide range of
health and food industrial applications
Effects of Climate Change on the Distribution of Scomber japonicus and Konosirus punctatus in China?s Coastal and Adjacent Waters
No full textClimate change has increasingly impacted the marine environment, with various marine en- vironmental factors interacting to influenc fis distribution. Assessing the impact of climate change on the future distribution of fis depends on understanding how biological responses interact with environmental conditions. Enhancing our understanding of the potential impacts of climate change is crucial for the sustainable development of marine fisheries In this study, we analyzed the habitat suitability of Scomber japonicus and Konosirus punctatus in the coastal waters of China (17??41? N, 107??130? E) using marine environmental data, including, as follows: sea surface temperature (SST); sea surface salinity (SSS); pH; and biological occurrence data from 2000 to 2010. A maximum entropy (MaxEnt) model was employed to predict the future distribution of these two species based on the shared socioeconomic pathway (SSP) scenarios for 2040?2050 and 2090?2100. The results indicate that climate change will significantl affect the future habitat distribution of S. japonicus and K. punctatus, leading to a decrease in suitable habitat areas offshore China and a gradual shift northeastward in the center of these habitats. These finding are essential for understanding the impacts of climate change on the distribution of S. japonicus and K. punctatus, with significan implications for fisherie resource assessment and management
Can stocking with advanced European grayling fry strengthen its populations in the wild?
No full textEuropean grayling, Thymallus thymallus (Linnaeus, 1758) (Actinopterygii: Salmoniformes: Salmonidae), represents one of the
highly attractive riverine fishing species in Europe. Its populations have declined in the Czech Republic due to various adverse
factors. Current approaches for strengthening these populations based on restocking with artificially reared 1+ or 2+ old individuals
have proven to be ineffective. This study focuses on the possibilities of supporting or restoring these populations by reintroducing
two-month-old, fast-growing fry reared in ponds. In June 2021, 5400 advanced fry marked with Alizarin Red (ARS) were introduced
into three free-flowing South Bohemian streams. The recapture rates and biometric data (length and weight) of stocked
grayling were assessed at the release sites as well as further downstream. The first electrofishing monitoring was conducted at the
end of the growing season (October) and after their first winter (March). Water temperature and flow rate at the stocking sites were
monitored throughout the growing season. The substantial number of recaptured individuals across all monitored sites suggests
that the fry successfully adapted to their new habitat and significantly contributed to the composition of local fish communities.
Downstream movement of stocked fry correlated with lower water temperatures and higher flows. Our findings demonstrate that
some introduced individuals successfully overwintered at all three reintroduction sites. Marking with ARS has proven to be a very
effective non-invasive method of group marking juvenile fish and is suitable for monitoring stocking programs. The production
and stocking of fast-growing advanced fry of European grayling is thus a promising strategy for revitalizing and strengthening the
populations of this threatened fish in running waters
Effect of Polystyrene Microplastic Exposure on Individual, Tissue, and Gene Expression in Juvenile Crucian Carp (Carassius auratus)
No full textExposure to an environment containing microplastics can cause adverse effects on creatures through respiratory and digestive systems. In this paper, 50?500 m polystyrene microplastics (expo- sure concentrations were 200 g/L, 800 g/L, and 3200 g/L concentrations) were selected to study the distribution of polystyrene microplastics (PS-MPs) and the effects on the growth, development, tissue damage and gene expression of crucian carp juveniles. The results showed that PS-MPs were enriched in the intestinal tract (GIT) and gill tissue of crucian carp, and the average number of PS-MPs was between 0 to 2.33 items per individual. It was found that the average number of MPs in the intestine was more than in the gills, and it was independent of the PS-MP concentration. However, the specifi gravity of PS-MPs in excreta was concentration-dependent. In addition, it was found that the exposure of the medium concentration group promoted the weight of the crucian carp larvae, inhibited the growth rate, and reduced the weight in the low and high concentration groups. The histopathological results indicated that the intestinal, gill, brain, and liver tissues all showed different degrees of damage, and the higher the concentration of PS-MPs, the more severe damage to the tissue cells. This experiment evaluated 15 genes in three treatments, which found that PS-MPs had different effects on gene expression in the liver, intestine, and gill tissues, and the tested genes were involved in different response pathways associated with virulence
Direct Preparation of Alginate Oligosaccharides from Brown Algae by an Algae-Decomposing Alginate Lyase AlyP18 from the Marine Bacterium Pseudoalteromonas agarivorans A3
No full textAlginate oligosaccharides (AOs), derived from alginate degradation, exhibit diverse biological activities and hold significant promise in various fields. The enzymatic preparation of AOs relies on alginate lyases, which offers distinct advantages. In contrast to the conventional use of
sodium alginate derived from brown algae as the substrate for the enzymatic preparation of AOs, AO preparation directly from brown algae is more appealing due to its time and energy efficiency. Thus, the identification of potent alginate lyases and cost-effective brown algae substrates is crucial for optimizing AO production. Herein, we identified and characterized an alginate lyase, AlyP18, capable of efficiently decomposing algae, from a marine bacterium Pseudoalteromonas agarivorans A3
based on secretome analysis. AlyP18 is a mesothermal, endo-type and bifunctional alginate lyase
with high enzymatic activity. Two brown algae substrates, Laminaria japonica roots and Macrocystis pyrifera, were used for the AO preparation by AlyP18. Upon optimization of AlyP18 hydrolysis parameters, the substrate degradation efficiency and AO production reached 53% and ~32% for L. japonica roots, respectively, and 77% and ~46.5% for M. pyrifera. The generated AOs primarily consisted of dimers to pentamers, with trimers and tetramers being dominant. This study provides an efficient alginate lyase and alternative brown algal feedstock for the bioconversion of high-value AOs from brown algae
