Low Growth Research Articles

Comparing body composition measures in children with end stage liver disease using noninvasive bioimpedance analysis

BackgroundChronic liver disease (CLD) in children, often leads to cirrhosis and end-stage liver disease (ESLD). CLD poses significant challenges in management and prognosis. Assessing body composition, including sarcopenia, is increasingly recognized as important in understanding outcomes in this population.MethodsWe conducted a prospective observational study, involving children aged 2 to 18 years with ESLD awaiting liver transplantation. Socio-demographic, clinical, and laboratory data were collected, and body composition was assessed using Bioelectrical Impedance Analysis (BIA). Sarcopenia was defined using age-specific cut-off points for appendicular skeletal muscle mass (aSMM) and fat-free mass (FFM).ResultsThe study included 57 children (42.1% girls, 57.9% boys; median age: 10.9 years) with liver cirrhosis. Of them 11 (19.3%) died during the study. The mean duration of living with end-stage liver disease prior to participation was 5.43 years [IQR: 3.32, 8.39]. The most common etiology was biliary atresia (24.6%), followed by cryptogenic (22.8%). Deceased children exhibited significantly higher sarcopenia prevalence, lower basal metabolic rate and growth scores compared to survivors (P < 0.05), (771.0 vs. 934.0, P = 0.166) (65.0 vs. 80.5, P = 0.005). Total body and limb-specified lean mass were lower in deceased children, although not statistically significant. Similarly, total mineral (90% normal) and bone mineral content were lower in deceased children, with a significant difference observed only in water-to-FFM percentage (72.5 vs. 73.1, P = 0.009).ConclusionThis study highlights the high prevalence of sarcopenia among children with ESLD and its association with adverse outcomes, including mortality. Bioimpedance analysis emerges as a promising, non-invasive method for assessing body composition in pediatric ESLD, warranting further investigation and integration into clinical practice.

Regional analysis of agricultural bank liquidity

PurposeThe purpose of this article is to determine the regional economic factors and bank characteristics that significantly contribute to changes in bank liquidity. We also seek to identify regions that may be most susceptible to liquidity tightening.Design/methodology/approachFor this article we use data on deposits from commercial banks, Federal Reserve survey data and indicators of regional and agricultural economic conditions. We specify a panel regression with fixed effects to model how liquidity at agricultural banks has changed and to identify the most significant drivers.FindingsOur results suggest that small banks and banks with branch networks located in areas more concentrated in agricultural production bear the greatest risk of reduced liquidity.Practical implicationsPrior to the pandemic and more recently, lower deposit growth, combined with strong demand for agricultural loans, has led to reductions in liquidity at agricultural banks. Lower liquidity could reduce credit availability for farm borrowers and increase risks for banks that must rely on alternative sources of funding to meet loan demand.Originality/valuePrevious research has shown that exogenous shocks from other economic sectors, such as energy, can significantly affect bank liquidity, but research is limited on how agricultural bank liquidity is affected by downturns in the agricultural economy and other regional economic factors. Another contribution is this paper’s analysis of regional disparities in bank liquidity.

Growth and evolution of Ni-Ti-Si type G phase Ni16Ti6Si7 in Cu alloys

By changing the cooling rate and adding P element, the morphology of primary Ni16Ti6Si7 in hypereutectic Cu-Ni-Si-Ti alloy has been analyzed in detail, and its growth mechanism has been discussed. Increasing the cooling rate can enhance the nucleation and growth of the primary phase. However, excessive cooling rates may result in constitutional supercooling, leading to the primary phase exhibiting various shapes. During the growth process, the crystal will preferentially grow along the 〈100〉 direction, and eventually cause the {100} facets to degenerate into corners, while the {111} facets retain and forms the octahedral Ni16Ti6Si7 due to the lower growth rate. Meanwhile, when the external growth conditions are changed, such as adding P element, the relative growth rate of <1 0 0 > and 〈111〉 directions will be changed, and the {1 0 0} facets will eventually remain and form cubic Ni16Ti6Si7.

Microvesicles derived from mesenchymal stem cells inhibit acute respiratory distress syndrome-related pulmonary fibrosis in mouse partly through hepatocyte growth factor.

Pulmonary fibrosis is one of the main reasons for the high mortality rate among acute respiratory distress syndrome (ARDS) patients. Mesenchymal stromal cell-derived microvesicles (MSC-MVs) have been shown to exert antifibrotic effects in lung diseases. To investigate the effects and mechanisms of MSC-MVs on pulmonary fibrosis in ARDS mouse models. MSC-MVs with low hepatocyte growth factor (HGF) expression (siHGF-MSC-MVs) were obtained via lentivirus transfection and used to establish the ARDS pulmonary fibrosis mouse model. Following intubation, respiratory mechanics-related indicators were measured via an experimental small animal lung function tester. Homing of MSC-MVs in lung tissues was investigated by near-infrared live imaging. Immunohistochemical, western blotting, ELISA and other methods were used to detect expression of pulmonary fibrosis-related proteins and to compare effects on pulmonary fibrosis and fibrosis-related indicators. The MSC-MVs gradually migrated and homed to damaged lung tissues in the ARDS model mice. Treatment with MSC-MVs significantly reduced lung injury and pulmonary fibrosis scores. However, low expression of HGF (siHGF-MSC-MVs) significantly inhibited the effects of MSC-MVs (P < 0.05). Compared with the ARDS pulmonary fibrosis group, the MSC-MVs group exhibited suppressed expression of type I collagen antigen, type III collagen antigen, and the proteins transforming growth factor-β and α-smooth muscle actin, whereas the siHGF-MVs group exhibited significantly increased expression of these proteins. In addition, pulmonary compliance and the pressure of oxygen/oxygen inhalation ratio were significantly lower in the MSC-MVs group, and the effects of the MSC-MVs were significantly inhibited by low HGF expression (all P < 0.05). MSC-MVs improved lung ventilation functions and inhibited pulmonary fibrosis in ARDS mice partly via HGF mRNA transfer.

Evaluation of Tilapia (Oreochromis niloticus) Survival and Growth in Aquaculture Systems with Different Feed Types

Proper feeding is crucial for promoting fast and healthy growth in fish, contributing to increased overall production. However, access to high-nutritional feed is not always feasible. Utilizing locally available ingredients presents a potential solution to this challenge. Consequently, this research aims to assess the impact of locally available feed ingredients on the growth and production of tilapia (O. niloticus) in Liberia. Three types of fish feed were prepared, namely Africa Rice fish feed (diet 1), soybeans fish feed (diet 2), and Gbarnga fish feed (control), each with distinct compositions. These feeds were evaluated to determine their effects on the growth and production performance of tilapia fish for the duration of 31 weeks. Fifty fish with an initial body weight of 12 g each were stocked in each hapa net. Data on survival rate (%), feed conversion ratio (FCR), and growth (g) were collected and compared. The growth results revealed a statistically significant difference (P &lt; 0.001) among the three selected fish feed types. Diet 1 exhibited a higher average mean weight of 1521.67 g per 92 fish followed by the control with an average mean weight of 1315.56 g per 88 fish, while diet 2 demonstrated comparatively lower growth, 1164.44 g per 96 fish. Survival rate and FCR, however, exhibited no significant differences. Notably, the cost of food supplies, particularly proteins, may constrain farmers' access to feed processing and formulation technology. Consequently, the findings of this study are expected to address challenges related to feed formulation and processing, providing valuable insights for the enhancement of fish farming practices.

Analysis of Tamarix chinensis Forest Characteristics, Salt Ion Distribution, and Non-Structural Carbohydrate Levels in the Yellow River Delta: A Spatial Study Based on Proximity to the Shoreline.

The distribution of vegetation in coastal wetlands is significantly influenced by soil properties. However, the mechanisms of how soil characteristics impact the physiological processes of Tamarix chinensis forests remain underexplored. This study examined changes in the soil physicochemical properties and structural attributes of natural T. chinensis forests in the Yellow River Delta with increasing distance from the shoreline. T. chinensis trees were classified into healthy, intermediate, and dying categories based on growth potential, and dynamic changes in salt ions and non-structural carbohydrates (NSCs) were investigated. Results indicated that increasing distance from the shoreline corresponded to decreased soil salinity and pH, and increased soil moisture. T. chinensis mortality rate decreased, while tree height and ground diameter increased with distance. Soil salt content was positively correlated with T. chinensis mortality, but negatively correlated with tree height and ground diameter. Trees with lower growth potential had higher Na+ but lower K+ and K+/Na+ ratio. Soil salt content was positively correlated with root and stem Na+, while soil moisture was positively correlated with leaf NSCs. These findings suggest that soil salt content and moisture significantly influence T. chinensis ion absorption and NSC accumulation, with sodium toxicity being a key factor in the spatial distribution of T. chinensis forests.

Transition in production and export potential of garlic in India

The present study analyzed the performance of production and export of Indian garlic based on secondary data collected from different governments departmental repositories and websites. Statistical techniques like mean, standard deviation, regression and CAGR was applied for analysis. Garlic held quantity share (29.68 %) of aggregate production of Indian spices. But in export front the share of quantity and value share of garlic estimated only 2.30 % and 1.21 % respectively of total spices export from the country. India ranked 2nd after China possessing 5.85% share of global production and growing with 9.93 % CAGR over last 15 years (2006-2020) which was 3.5 times higher than China. The major destinations for garlic export from India are Malaysia, Thailand, USA, Vietnam (South) and Nepal altogether constituted around 41 % value of average annual export. But out of these countries, negative trend in export was found in three countries makes India searching for new clients. The lower growth rate (CAGR) of productivity (1.91 %) of garlic compared to acreage (5.46 %) over three decades (1990-91 to 2020-21) harnesses for technological breakthrough. Two producing states of India viz., Madhya Pradesh and Rajasthan account around 78.34 % of national production. But in terms of productivity, Punjab (11.39 t/ha), Haryana (10.67 t/ha) and Madhya Pradesh (10.31 t/ha) led the country. Enhancement of productivity through technological development and adequate market infrastructures along with improvement in post harvest management of the crop particularly processing might be given importance to increase production and export potential of garlic.

Impact of dye treatment as management strategy on available light may favour a highly invasive alien aquatic plant

Attempts to control massive proliferations of invasive alien aquatic plants (IAAP) are often ineffective. A renewed interest for dye treatment is emerging aiming to control the submerged macrophyte Myriophyllum heterophyllum in France. We aimed to understand the effects of dye on this plant knowing about its adaptation to low light. In a 2 × 2 factorial design experiment, we assessed the effect of a dye mixture based on Brilliant Blue (E133) and Allura Red (E129) at high and low light intensities on light quantity and quality and how this might affect the plant’s performance by measuring morphological and physiological traits. A multivariate analysis identified three groups – high light (HL) plants, plants in high light with dye (HLD) or low light (LL), and low light with dye (LLD) plants. HL plants performed well but showed stress signs, with a reduced main shoot length, a higher leaf dry matter content (LDMC) and a lower nitrogen content (N), not observed in plants grown in HLD or LL. HLD and LL plants exhibited a comparable total length growth rate to those in HL, but had lower LDMC and higher N contents. LLD plants performed poorly with the lowest growth and signs of physiological stress. Dye-induced changes in light quality only marginally affected the absorbance range of chlorophyll b, which apparently did not affect photosynthesis. Commercially available dyes currently used to control nuisance aquatic plants thus seem to have little or no effect on submerged macrophytes. The presence of dye may exacerbate negative effects of very low light intensities on the plant’s growth. However, these very low intensities would only be reached during high-water levels or in winter, periods where the dye would rapidly be diluted. During summer, however, the application of dye may protect the plant from damaging light intensities and thus not be a good management strategy to control low light adapted invasive submerged macrophytes.

Low defect density in MoS2 monolayers grown on Au(111) by metal-organic chemical vapor deposition

Monolayers of transition metal dichalcogenides (TMDs) possess high potential for applications in novel electronic and optoelectronic devices and therefore the development of methods for their scalable growth is of high importance. Among different suggested approaches, metal-organic chemical vapor deposition (MOCVD) is the most promising one for technological applications because of its lower growth temperature compared to the most other methods, e.g., conventional chemical vapor or atomic layer deposition (CVD, ALD). Here we demonstrate for the first time the epitaxial growth of MoS2 monolayers on Au(111) by MOCVD at 450 °C. We confirm the high quality of the grown TMD monolayers down to the atomic scale using several complementary methods. These include Raman spectroscopy, non-contact atomic force microscopy (nc-AFM), X-ray photoelectron spectroscopy and scanning tunneling microscopy (STM). The topographic corrugation of the MoS2 monolayer on Au(111), revealed in a moiré structure, was measured as ≈20 pm by nc-AFM. The estimated defect density calculated from STM images of the as-grown MoS2 monolayers is in the order of 1012 vacancies/cm2. The defects are mainly caused by single sulfur vacancies. Our approach is a step forward towards the technologically relevant growth of high-quality, large-area TMD monolayers.

Characterising high school students’ interest trajectory profiles

ABSTRACT Students’ declining interest in science has become a significant concern. We approached this problem from multiple interests perspective. This study aimed to classify high school senior students’ interest trajectory profiles and extract the characteristics of each profile. 653 students in Japan answered online questionnaires with two-month interval about their interest in STEM, Humanities and Social Science (HSS), and non-academic subjects. We also collected data on self-efficacy and growth mindset. Latent Growth Curve Modelling revealed an overall decline in students’ interest across these three areas of interest. Latent Growth Class Analysis revealed seven interest trajectory profiles. ANOVA tests showed no self-efficacy variations across profiles but found lower growth mindsets in the favourable profile characterised by its high and sustained interest across all categories. Our findings suggest that the observed decrease in STEM interest was not associated with an increase in interest in other areas. In other words, during the survey period, there seems no indication of a competitive relationship between the interest in STEM and the other areas, as increases in interest were absent across these three areas of interests. Additionally, the finding suggests two implications for developing the multiple interests perspective: narrowing or expanding its scope.

Optimal glycine allowance levels in low-protein diets and the dynamic requirement model for broilers

This study aimed to investigate the effects of different glycine levels in low-protein diets on the growth, nitrogen deposition, and expression of intestinal amino acid and glucose transporters in broilers from 29 to 42 days of age, in order to determine the optimal glycine supplementation level. A total of 240 male broilers at 29 days old were randomly assigned to 5 groups: the control group with a crude protein level of 20%, and experimental groups with low-protein diets (LP130) containing 18% crude protein, supplemented with glycine to achieve standardized ileal digestible (SID) glycine + serine to lysine ratios of 134% (LP134), 140% (LP140), and 145% (LP145). The results showed that the LP134 group had similar growth performance and slaughter performance compared to the control group (P > 0.05), whereas other low-protein diet groups had significantly lower growth performance (P < 0.05). Regression analysis determined that the optimal ratio for SID glycine + serine to lysine was 137%. A dynamic model for glycine + serine requirements was established through binary regression analysis: y = 599.051 × BW^0.75 + 8.381 × ADG (R2 = 0.998, P < 0.001). Feeding LP134, LP140, and LP145 diets significantly improved nitrogen deposition rates in broilers (P < 0.05). Low-protein diets significantly upregulated mRNA levels of b0,+AT, EAAT3, and SGLT1 genes in the duodenum (P < 0.05). In conclusion, appropriate glycine supplementation in low-protein diets can enhance growth performance, and nitrogen deposition efficiency, and regulate the expression of intestinal amino acid and glucose transporters. The optimal ratio of SID glycine + serine to lysine in low-protein diets for broilers aged 29 to 42 days is 137%.

Activated sludge microbial community assembly: the role of influent microbial community immigration.

Wastewater treatment plants (WWTPs) are host to diverse microbial communities and receive a constant influx of microbes from influent wastewater. However, the impact of immigrants on the structure and activities of the activated sludge (AS) microbial community remains unclear. To gain insight on this phenomenon known as perpetual community coalescence, the current study utilized controlled manipulative experiments that decoupled the influent wastewater composition from the microbial populations to reveal the fundamental mechanisms involved in immigration between sewers and AS-WWTP. The immigration dynamics of heterotrophs were analyzed by harvesting wastewater biomass solids from three different sewer systems and adding to synthetic wastewater. Immigrating influent populations were observed to contribute up to 14% of the sequencing reads in the AS. By modeling the net growth rate of taxa, it was revealed that immigrants primarily exhibited low or negative net growth rates. By developing a protocol to reproducibly grow AS-WWTP communities in the lab, we have laid down the foundational principles for the testing of operational factors creating community variations with low noise and appropriate replication. Understanding the processes that drive microbial community diversity and assembly is a key question in microbial ecology. In the future, this knowledge can be used to manipulate the structure of microbial communities and improve system performance in WWTPs.IMPORTANCEIn biological wastewater treatment processes, the microbial community composition is essential in the performance and stability of the system. This study developed a reproducible protocol to investigate the impact of influent immigration (or perpetual coalescence of the sewer and activated sludge communities) with appropriate reproducibility and controls, allowing intrinsic definitions of core and immigrant populations to be established. The method developed herein will allow sequential manipulative experiments to be performed to test specific hypothesis and optimize wastewater treatment processes to meet new treatment goals.

Elevated Tropical Sea Surface Temperatures During the Globally Warm Miocene Caused Heat Stress for Caribbean Coral Reefs

ABSTRACTThe warm Miocene (23.0–5.3 Ma) is considered a model case for the global climate of the near future. In view of the current coral reef crisis, studies on Miocene reefs can contribute to predictions regarding the stress resilience of today's reefs against global warming. A Late Miocene (6.2–5.5 Ma) reef coral fauna from Hispaniola Island (Caribbean) characterised by ecologically tolerant taxa was originally interpreted to reflect cool‐eutrophic waters. However, the associated planktonic foraminifer assemblage and new TEX86H–based temperature reconstructions document an oligotrophic shallow‐water environment harbouring 30–31°C. Thus, in conjunction with unusually low vertical growth rates and erratic trace element signatures of massive reef corals, the coral fauna documents critically high temperatures and a response to heat stress rather than cool upwelling. The findings demonstrate the relevance of understanding shallow‐water ecosystems from past warm periods for developing scenarios of a future, warmer world.

Growth at 2 years corrected age in preterm infants discharged on two different breast milk enhancements: An observational study.

Breast milk (BM) enhancement is often used to meet the nutritional needs of preterm infants after hospital discharge to achieve optimal growth. This study compared growth at 18-28 months corrected age (CA) among very preterm (VP) and very low birth weight (VLBW) infants discharged from the neonatal intensive care units (NICUs) on two BM enhancements. We conducted a retrospective chart review study of infants born between January 1, 2013 and December 31, 2017, with gestational age < 32 weeks or birthweight < 1500 g, discharged from the NICU on BM enhancements; fortification of BM with infant formula additives (BM-F) or unfortified BM supplemented with bottle feeds of infant formula (BM-S). BM enhancements were nonrandomized and determined by the medical team. A linear mixed model regression analysis with propensity score matching was used to estimate the adjusted associations between the nutrition plan at discharge and growth outcomes at 18-28 months CA follow-up. Two hundred and fifty-one VLBW/VP infants were included. Compared with BM-S, infants discharged on BM-F were more likely to continue receiving BM at 8-12 months CA, and had lower head circumference, weight-for-length z scores, and higher incidence of moderate malnutrition (p ≤ 0.01). After adjusting for confounders, discharge on BM-F was associated with a lower incidence of overweight/obesity at 18-28 months CA (odds interval: 0.45; confidence interval: 0.21-0.96; p = 0.04). This retrospective study suggests that VLBW/VP infants discharged on BM-F received BM longer, had lower growth parameter and were less likely to be overweight/obese at 18-28 months CA. Further studies are needed to evaluate the role of postdischarge nutrition on preterm born children's growth, metabolic disease, and neurodevelopmental outcomes.

Is economic growth less welfare enhancing in Africa? Evidence from the last forty years

On current trends, the future of global poverty reduction will be determined by Sub-Saharan Africa (SSA). Yet, poverty reduction has been relatively slow on the continent, even during periods of strong economic growth. The empirical literature has argued that this is due to the lower growth elasticity of poverty in SSA compared to other regions. This paper contributes to this debate by i) using an up-to-date and expanded sample of 575 successive and comparable growth spells between 1981 and 2021 and 2) unpacking the factors that contribute to the lower growth elasticity of poverty in SSA. First, the analysis confirms previous findings that economic growth (which we measure by growth in GDP per capita) has consistently been less poverty-reducing in SSA, even after controlling for initial differences in poverty, income levels, and inequality (and changes therein). Second, we find that the lower growth elasticity is due to a significantly lower passthrough between growth in GDP per capita and growth in household income or consumption as measured from surveys. GDP growth is particularly ineffective in improving the incomes of the poorest households, whose consumption expenditures in SSA are independent of economic growth, in contrast to low-income households elsewhere. Third, examining the factors that mediate the passthrough between GDP growth and household welfare, we find that limited provision of basic education services and basic infrastructure and the slow process of structural transformation inhibit the passthrough between economic growth and household welfare, as do dependence on natural resources and occurrence of violent conflicts. Overall, variables that strengthen (weaken) the effect of aggregate economic growth on household welfare are scarcer (more abundant) in SSA, which partly explains the weaker effect of economic growth on household welfare.

Chinese-style carbon emission reduction: Micro mechanisms of state-owned enterprises

This article investigates whether state-owned enterprises (SOEs) exhibit a positive response to regional pressure for carbon emission reduction. By collecting and analyzing firm-level carbon emissions data in China from 2008 to 2021, we find that when faced with increased pressure to reduce emissions in a specific region, SOEs exhibit a substantial reduction in their carbon emissions compared to non-SOEs. Furthermore, this relationship is more remarkable among enterprises operating in high-emission industries and located in regions characterized by low economic growth objectives, but there is no heterogeneity in the executive environmental background. The mechanisms of political promotion incentives for SOE executives play a significant role in mitigating emissions through the combined effects of promoting green innovation and reducing output. Additionally, SOEs demonstrating stronger efforts in carbon emissions reduction are more likely to receive the compensations from governments, including green subsidies and lower bank credit costs and they have exhibited superior economic performance in subsequent years. These findings reveal the micro mechanisms behind China's regional carbon reduction and highlight the crucial role played by SOEs.

Organic farming and annual flower strips reduce parasite prevalence in honeybees and boost colony growth in agricultural landscapes

Abstract Despite the major role that insect pollinators play in crop production, agricultural intensification drives them into decline. Various conservation measures have been developed to mitigate the negative effects of agriculture on insect pollinators. In a novel comparison of the efficacy of three conservation measures on honeybee colony growth, we monitored experimental honeybee colonies in 16 landscapes that comprised orthogonal gradients of organic agriculture, annual flower strips and perennial semi‐natural habitats. Using structural equation modelling, we assessed the effects of conservation measures on the prevalence of 11 parasites, Varroa destructor loads and their collective impact on colony growth. Increasing area coverage of perennial semi‐natural habitat related to higher V. destructor load and indirectly to lower colony growth. Increasing area of annual flower strips was associated with lower V. destructor load and indirectly with higher colony growth. Increasing area of organic farming related to lower parasite richness and also directly to improved colony growth. Synthesis and applications: Landscape features can affect pollinators directly through the provision of food resources and indirectly through modulation of parasite prevalence. To promote honeybee colony health in agro‐ecosystems, our results suggest that organic agriculture and annual flower strips should be prioritized conservation measures. Landscape management should consider the merits and demerits of different measures to sustain healthy populations of pollinators in agro‐ecosystems.

An Analysis of the Patterns of Economic Growth in the US

ABSTRACT This article seeks to investigate which demand component led and shaped the growth patterns of the US economy between 1954 and 2020 and comprehensive sub-periods relying on a proper allocation of imports. In doing so, it aims to establish whether the external sector can make a positive contribution to growth even in a context of negative net exports. Finally, it seeks to shed light on the reasons for higher or lower output growth, drawing particular attention to the engines of growth in each historical period. This article takes a novel approach in two ways: (1) it calculates and analyzes the decomposition of the contributions to growth for the US; (2) it divides the analysis into sub-periods and engines of growth, separately analyzing movements in the components of the multiplier, the dynamics of each component’s share with respect to GDP, and their respective growth rates. The empirical results show that the very low growth rates experienced between 2008 and 2020 are mainly explained by a minimal contribution of the government sector accompanied by weak demand from the private sector, highlighting the importance of growth-oriented public policies. These negative results have been only partially compensated by improvements in the external sector.

Inhibition of Aspergillus spp. growth and ochratoxin A production in Conilon and Arabica coffees based-medium by Saccharomyces cerevisiae

Saccharomyces cerevisiae CCMA 0159 is reported as a promising biocontrol agent against ochratoxin A (OTA)-producing fungi in coffee. Coffea arabica and Coffea canephora (var. Conilon or Robusta) are the most widely consumed coffee species around the world, cultivated in tropical and subtropical regions, each exhibiting distinct physicochemical and sensory characteristics. The objective of this study was to compare the growth and OTA production by Aspergillus carbonarius, A. ochraceus, and A. westerdijkiae in C. arabica and C. canephora, along with assessing the efficiency of S. cerevisiae CCMA 0159 in biocontrolling ochratoxigenic fungi in both coffee varieties. A. carbonarius exhibited a higher growth rate and OTA production in both coffee varieties, with C. canephora showing particular susceptibility. Conversely, A. ochraceus and A. westerdijkiae demonstrated lower growth and OTA production. S. cerevisiae was effective in biocontrolling the fungal isolates, inhibiting over 80 % of A. carbonarius growth in both coffee varieties. Among the mechanisms of action of the biological control agent, the production of volatile organic compounds stands out. The results of this study confirm the significant potential of S. cerevisiae CCMA 0159 as a biocontrol agent against Aspergillus for application in coffee-producing areas.

Migratory-derived resources induce elongated food chains through middle-up food web effects

BackgroundSeasonal movements of animals often result in the transfer of large amounts of energy and nutrients across ecosystem boundaries, which may have large consequences on local food webs through various pathways. While this is known for both terrestrial- and aquatic organisms, quantitative estimates on its effects on food web structure and identification of key pathways are scarce, due to the difficulty in obtaining replication on ecosystem level with negative control, i.e. comparable systems without migration.MethodsIn this study, we estimate the impact of Arctic charr (Salvelinus alpinus) migration on riverine ecosystem structure, by comparing multiple streams with strictly resident populations above natural migration barriers with streams below those barriers harboring partially migratory populations. We compared density estimates and size structure between above and below populations. Diet differences were examined through the analysis of stomach contents, changes in trophic position were examined by using stable isotopes. To infer growth rate of resident individuals, back-growth calculation was performed using otoliths.ResultsWe find higher densities of small juveniles in partially migratory populations, where juvenile Arctic charr show initially lower growth, likely due to higher intraspecific competition. After reaching a size, where they can start feeding on eggs and smaller juveniles, which are both more frequent in partially migratory populations, growth surpasses that of resident populations. Cannibalism induced by high juvenile densities occurred almost exclusively in populations with migration and represents an altered energy pathway to the food web. The presence of large cannibalistic charr feeding on smaller ones that have a similar trophic level as charr from strictly resident populations (based on stomach content) coupled with steeper δ15N-size regression slopes illustrate the general increase of food chain length in systems with migration.ConclusionsOur results thus suggest that the consumption of migration-derived resources may result in longer food chains through middle-up rather than bottom-up effects. Furthermore, by occupying the apex of the food chain and feeding on juvenile conspecifics, resident individuals experience reduced competition with their young counterparts, which potentially balances their fitness with migratory individuals.