Positive Interactions Between Lactic Acid Bacteria Could Be Mediated by Peptides Containing Branched-Chain Amino Acids

Lactic acid bacteria (LAB) are responsible for the sanitary, organoleptic, and health properties of most fermented products. Positive interactions between pairs of LAB strains, based on nitrogen dependencies, were previously demonstrated. In a chemically defined medium, using milk and lupin proteins as sole nitrogen source, two proteolytic strains were able to sustain the growth of non-proteolytic strains, but one did not. The objective of the present study was, thus, to determine which specific peptides were implicated in the positive interactions observed. Peptides produced and involved in the bacterial interactions were quantified using tandem mass spectrometry (LC-MS/MS). About 2,000 different oligopeptides ranging from 6 to more than 50 amino acids in length were identified during the time-course of the experiment. We performed a clustering approach to decipher the differences in peptide production during fermentation by the three proteolytic strains tested. We also performed sequence alignments on parental proteins and identified the cleavage site profiles of the three bacterial strains. Then, we characterized the peptides that were used by the non-proteolytic strains in monocultures. Hydrophobic and branched-chain amino acids within peptides were identified as essential in the interactions. Ultimately, better understanding how LAB can positively interact could be useful in multiple food-related fields, e.g., production of fermented food products with enhanced functional properties, or fermentation of new food matrices.

Co-occurrence Interaction Networks of Extremophile Species Living in a Copper Mining Tailing

Copper mining tailings are characterized by high concentrations of heavy metals and an acidic pH, conditions that require an extreme adaptation for any organism. Currently, several bacterial species have been isolated and characterized from mining environments; however, very little is known about the structure of microbial communities and how their members interact with each other under the extreme conditions where they live. This work generates a co-occurrence network, representing the bacterial soil community from the Cauquenes copper tailing, which is the largest copper waste deposit worldwide. A representative sampling of six zones from the Cauquenes tailing was carried out to determine pH, heavy metal concentration, total DNA extraction, and subsequent assignment of Operational Taxonomic Units (OTUs). According to the elemental concentrations and pH, the six zones could be grouped into two sectors: (1) the “new tailing,” characterized by neutral pH and low concentration of elements, and (2) the “old tailing,” having extremely low pH (~3.5) and a high concentration of heavy metals (mainly copper). Even though the abundance and diversity of species were low in both sectors, the Pseudomonadaceae and Flavobacteriaceae families were over-represented. Additionally, the OTU identifications allowed us to identify a series of bacterial species with diverse biotechnological potentials, such as copper bioleaching and drought stress alleviation in plants. Using the OTU information as a template, we generated co-occurrence networks for the old and new tailings. The resulting models revealed a rearrangement between the interactions of members living in the old and new tailings, and highlighted conserved bacterial drivers as key nodes, with positive interactions in the network of the old tailings, compared to the new tailings. These results provide insights into the structure of the soil bacterial communities growing under extreme environmental conditions in mines.

Large household reduces dementia mortality.

Background Large households/families create more positive psychological well-being which may offer a life course protection against dementia development and deliver more comprehensive healthcare to dementia patients. Methods Dementia specific mortality rates of the 183 member states of World Health Organization were calculated and matched with the respective country data on household size, Gross Domestic Product (GDP), urban and ageing. Scatter plots were produced to explore and visualize the correlations between household size and dementia mortality rates. Pearsons and nonparametric correlations were used to evaluate the strength and direction of the associations between household size and all other variables. Partial correlation of Pearsons moment-product approach was used to identify that household size protects against dementia regardless of the competing effects from ageing, GDP and urbanization. Multiple regression identified large household was a significant predictor of dementia mortality. Results Household size was in a negative and moderately strong correlation (r = -0.6034, p < 0.001) with dementia mortality. This relationship was confirmed in both Pearson r (r= - 0.524, p<0.001) and nonparametric (rho = -0.579, p < 0.001) analyses. Regardless of the contribution of ageing, SES and urban lifestyle to dementia mortality, large household was an independent predictor of dementia mortality (r = −0.331, p <0.001) in partial correlation analysis. Stepwise multiple regression analysis selected large household as the variable having the greatest contribution to dementia mortality with R2 = 0.263 while ageing was placed second increasing R2 to 0.259. GDP and urbanization were removed as having no statistically significant influence on dementia mortality. Conclusions Independent of ageing, urbanization and GDP, large household protects against dementia mortality. As part of dementia prevention, healthcare practitioners should encourage people to increase their positive interactions with persons from their neighbourhood or other fields where large household/family size is hard to achieve.

Positive Interactions Drive Bat Distribution in a Remote Oceanic Archipelago (Azores, Portugal)

One of the fundamental interests in ecology is understanding which factors drive species’ distribution. We aimed to understand the drivers of bat distribution and co-occurrence patterns in a remote, insular system. The two bat species known to occur in the Azores archipelago were used as a model. Echolocation calls were recorded at 414 point-locations haphazardly distributed across the archipelago. Calls were analysed and assigned to each species. Binominal generalised linear models were adjusted using different descriptors at two scales: archipelago and island. The presence of the co-occurring species was included at both scales. The results show that island isolation, habitat and climate play an essential role on the archipelago and island scales, respectively. However, the positive interaction between bat species was the most critical driver of species’ distribution at the island scale. This high co-occurrence pattern at the island scale may result from both species’ maximising foraging profit in a region where prey abundance may be highly variable. However, further research is necessary to clarify the mechanisms behind this positive interaction. Both species are threatened and lack specific management and protection measures. Maintaining this positive interaction between the two species may prove to be fundamental for their conservation.

Competition of insect decomposers over large vertebrate carrion: Necrodes beetles (Silphidae) vs blow flies (Calliphoridae)

Large carrion is inhabited by highly variable and interactive communities of insects. Positive interactions in carrion insect communities have been recently the focus in carrion ecology. By contrast, competition between carrion insects is rather undervalued. Here we provide evidence that blow flies (Calliphoridae) and Necrodes beetles (Silphidae), dominant decomposers of large carcasses in terrestrial habitats, compete over carrion. By reanalysing the results from 90 pig carcasses we demonstrated that the contribution of the flies and the beetles to the decay was negatively related. The greater part of the large carrion pool was monopolised by blow flies, whereas Necrodes beetles abundantly colonized carcasses, on which blow flies were less effective as decomposers. In behavioural assays, we found that adult beetles killed four times more frequently feeding than postfeeding third instar larvae of the flies, with the large decrease in the killing frequency after the larvae reached the age of early third instar. Therefore, adult Necrodes beetles preferentially killed the larvae that were before or in their peak feeding. The study provides evidence that the interaction between blow flies and Necrodes beetles is a combination of indirect exploitative effects of the flies and direct interference effects of the beetles (the mixed competition).

Relationships among Early Adversity, Positive Human and Animal Interactions, and Mental Health in Young Adults

Adverse childhood experiences (ACEs) are associated with poor mental health. Emerging research demonstrates the protective role of positive childhood experiences, including a positive sense of self and relationships with both humans and animals, in mitigating the impacts of early life adversity on mental health outcomes. This study examined whether benevolent childhood experiences (BCEs) or relationships and interactions with pets during childhood moderated the link between ACEs and current mental health symptoms in a sample of young adults. Students (N = 214) recruited from a public university in the U.S. completed an online survey. The results showed that ACEs were significantly associated with worse mental health symptoms, including anxiety and depression. Neither emotional closeness to a childhood pet dog nor positive interactions with a childhood pet were significant moderators of the relationship between ACEs and mental health. In contrast, more BCEs were associated with better mental health, and their interaction with ACEs was significant such that adversity-exposed young adults with high BCEs reported fewer mental health symptoms than those with low BCEs. The results highlight the need for continued research on differential experiences that may be protective in the relationship between adversity exposures and mental health.

Neighbors consistently influence growth and survival in a frequently burned savanna

Successful management of savannas is challenging and requires knowledge of the causes and consequences of the spatial arrangement of the trees. In savannas, trees are often aggregated, and the ability of trees within the clumps to survive fires plays a significant role in determining the savannas landscape dynamics. Whether or not a tree survives a fire is often dependent on the nature of their interactions with neighboring trees, positive or negative. In cases where disturbances are episodic, detecting these interactions is only going to be possible through long-term studies. Data reported here, from twenty-five years of annual tree censusing of a large grid-plot in a frequently burned savanna, showed consistent neighbor facilitated survival, irrespective as to whether the neighbors were conspecifics or heterospecifics. The positive interactions likely involve the reduction of both herbaceous and woody fuel in denser sites, and possibly mycorrhizal sharing among nearby trees.

Bridging the Distance: Accommodating Wildlife Interaction in an Urban Setting.

<p>Currently within the Wellington region there is an abundance of green spaces hosting a variety of native and exotic wildlife species (Rastandeh, Brown, & Pedersen Zari, 2018; “The Sanctuary,” 2018). These species are somewhat confined to a ‘home’ green space, in that travel between habitats involves difficult navigation between dense urban and residential structures (Forman, 1995; Rastandeh, Brown, et al., 2018). Many native species are not able to make long distance flights (Wittern & Berggren, 2007); and as a result habitat fragmentation is occurring at a rapid ecological level. The built form is limiting and discouraging wildlife movement, as well as being dangerous for smaller animals (Forman, 1995; Santiago, 2014). Currently tiny patches of vegetation provide wildlife with a directional indication of intended movement, but overall urban planning is designed for humans only. Aside from the lack of possible movement between habitats, there is also an absence of human connections to these spaces. There is a missed opportunity to introduce humans to ecological spaces, in that it allows a physical link and understanding to be achieved, as well as additional wellbeing benefits (Ell, 1981a; Santiago, 2014). With these two existing elements; the lack of wildlife movement between established habitats and the connectivity of humans to these spaces, there is also a third element of how interaction between people and wildlife within urban locations is absent. People are stuck with contributing towards the rapid decline of habitat, there are very limited positive interactions that are being utilised (Rastandeh, Brown, et al., 2018; Santiago, 2014). Infrastructure and specific designed elements that provide the correct facilities to allow for interactions between wildlife and humans is largely non-existent and crucial in the face of biodiversity loss and fragmentation. This thesis aims to establish a set of design guidelines towards understanding how interaction can be utilised within the design profession, as a way to reduce biodiversity loss, fragmentation and to increase exposure to unique species. Exploration at different scales, macro, meso and micro will be addressing different issues to answer the question of what types of interactions will be occurring within these spaces.</p>

Bridging the Distance: Accommodating Wildlife Interaction in an Urban Setting.

<p>Currently within the Wellington region there is an abundance of green spaces hosting a variety of native and exotic wildlife species (Rastandeh, Brown, & Pedersen Zari, 2018; “The Sanctuary,” 2018). These species are somewhat confined to a ‘home’ green space, in that travel between habitats involves difficult navigation between dense urban and residential structures (Forman, 1995; Rastandeh, Brown, et al., 2018). Many native species are not able to make long distance flights (Wittern & Berggren, 2007); and as a result habitat fragmentation is occurring at a rapid ecological level. The built form is limiting and discouraging wildlife movement, as well as being dangerous for smaller animals (Forman, 1995; Santiago, 2014). Currently tiny patches of vegetation provide wildlife with a directional indication of intended movement, but overall urban planning is designed for humans only. Aside from the lack of possible movement between habitats, there is also an absence of human connections to these spaces. There is a missed opportunity to introduce humans to ecological spaces, in that it allows a physical link and understanding to be achieved, as well as additional wellbeing benefits (Ell, 1981a; Santiago, 2014). With these two existing elements; the lack of wildlife movement between established habitats and the connectivity of humans to these spaces, there is also a third element of how interaction between people and wildlife within urban locations is absent. People are stuck with contributing towards the rapid decline of habitat, there are very limited positive interactions that are being utilised (Rastandeh, Brown, et al., 2018; Santiago, 2014). Infrastructure and specific designed elements that provide the correct facilities to allow for interactions between wildlife and humans is largely non-existent and crucial in the face of biodiversity loss and fragmentation. This thesis aims to establish a set of design guidelines towards understanding how interaction can be utilised within the design profession, as a way to reduce biodiversity loss, fragmentation and to increase exposure to unique species. Exploration at different scales, macro, meso and micro will be addressing different issues to answer the question of what types of interactions will be occurring within these spaces.</p>

The Combined Effect of Nitrogen Treatment and Weather Conditions on Wheat Protein-Starch Interaction and Dough Quality

The objective of this field crop study was to compare the effect of organic (cattle manure, off-season cover crop) and mineral N (NH4NO3; 0, 50, 100° 150 kg N ha−1) fertilizers on (i) gluten-starch interaction, and (ii) rheological properties of winter wheat dough. Data were collected from the long-term field experiment located in the Baltic Sea region (58°22’ N, 26°40’ E) in years 2013–2017. The amount of minuppueral N 150 kg ha–1 applied in two parts before flowering ensured higher gluten content (31 ± 3.3%) and dough quality (81 ± 7.4 mm) due to more positive interactions between gluten proteins and starch granules. The quality of dough was more variable in organic treatments (ranged up to 33%) because the availability of organic N was more variable and sensitivity to the weather conditions was higher. The mean variability of different dough properties over trial years under organic treatments was 1.4–2.0 times higher than in the treatment with 150 kg N ha−1.