Mass Aggregation Research Articles

Rate equationlimit for a combinatorial solution of a stochastic aggregation model.

In a recent series of papers, an exact combinatorial solution was claimed for a variant of the so-called Marcus-Lushnikov model of aggregation. In this model, a finite number of aggregates are initially assumed to be present in the form of monomers. At each time step, two aggregates are chosen according to certain size-dependent probabilities and irreversibly joined to form an aggregate of higher mass. The claimed result given an expression for the full probability distribution over all possible size distributions in terms of the so-called Bell polynomials. In this paper, we develop the asymptotics of this solution in order to check whether the exact solution yields correct expressions for the average cluster size distribution as obtained from the Smoluchowski equations. The answer is surprisingly involved: For the generic case of an arbitrary reaction rate, it is negative, but for the so-called classical rate kernels, constant, additive, and multiplicative, the solutions obtained are indeed exact. On the other hand, for the multiplicative kernel, a discrepancy is found in the full solution between the combinatorial solution and the exact solution. The reasons for this puzzling pattern of agreement and disagreement are unclear. A better understanding of the combinatorial solution's derivation is needed, the better to understand its range of validity.

Alatina alata box jellyfish monthly migrations in Hawai’i: Lunar and physical oceanographic triggers

Alatina alata, a species of box jellyfish, is found in distinct localities throughout tropical zones in the Atlantic, Pacific, and Indian Oceans, and is responsible for the most severe stings reported in Hawaiian coastal waters. Alatina alata is unique among species of box jellyfish (Cubozoa) in that it is only observed in shallow shoreline waters during lunar period-specific monthly mass aggregations and beaching events, which occur 8–10 days after each full moon. At other times of the lunar cycle, this species has been documented in pelagic zone surveys and is not observed close to shore (0 to 5 meter deep area, 0–100 m from shoreline). To assess potential ecological and environmental triggers for the synchronized shoreward migration behavior of Alatina alata, we investigated 14 years of beach count data in relation to lunar transit, luminosity, tides, and ocean currents using: a 14-year time series of Alatina alata pre-dawn counts; morphometric and reproductive status analyses; three full-transect nighttime shipboard observations; modeling studies; and additional supporting data. Model simulations show a persistent anticyclonic eddy in the study area, which may act as a source point for the jellyfish. Additionally, in situ night-long observations over three separate months revealed for the first time that Alatina alata actively swam en masse from over one mile offshore towards the shore before moonrise. Over 500 animals were observed and all showed strong shoreward swimming behavior perpendicular to the prevailing current. While the monthly populations each demonstrated heterogeneity with regard to size and beaching time, there was a slight trend towards the beaching of larger jellyfish first. Despite this heterogeneity in size, all animals were sexually mature adults replete with gametes or freshly spent. For the first time, we document that a key number of hours of darkness between twilight and moon rise correlate with the migration, and we hypothesize that this lunar cycle specific event triggers gonadal maturation in adult jellies, and maturation then triggers migrations to the shallow reef zone for spermcast mating.

Modeling the Future Tree Distribution in a South African Savanna Ecosystem: An Agent-Based Model Approach

Understanding the dynamics of tree species and their demography is necessary for predicting future developments in savanna ecosystems. In this contribution, elephant-tree and firewood collector-tree interactions are compared using a multiagent model. To investigate these dynamics, we compared three different tree species in two plots. The first plot is located in the protected space of Kruger National Park (KNP), South Africa, and the second plot in the rural areas of the Bushbuckridge Municipality, South Africa. The agent-based modeling approach enabled the modeling of individual trees with characteristics such as species, age class, size, damage class, and life history. A similar level of detail was applied to agents that represent elephants and firewood collectors. Particular attention was paid to modeling purposeful behavior of humans in contrast to more instinct-driven actions of elephants. The authors were able to predict future developments by simulating the time period between 2010 and 2050 with more than 500,000 individual trees. Modeling individual trees for a time span of 40 years might yield more detailed information than a simple woody mass aggregation. The results indicate a significant trend toward more and thinner trees together with a notable reduction in mature trees, while the total aboveground biomass appears to stay more or less constant. Furthermore, the KNP scenarios show an increase in young Combretum apiculatum, which may correspond to bush encroachment.

Reaction of cysteine residues with oxidized tyrosine residues mediates cross-linking of photo-oxidized casein proteins

Photo-oxidation of casein proteins is commonplace during milk processing and storage. A major consequence of such light exposure is protein cross-linking and aggregation. Although caseins are key milk components, the nature of the cross-links and the mechanisms involved are poorly characterized, with most previous work having been focused on detecting and quantifying di-tyrosine formed on dimerization of two tyrosine-derived phenoxyl radicals. However, this is only one of a large number of possible cross-links that might be formed. In this study, we have investigated the potential involvement of secondary reactions between oxidized protein side-chains and the thiol group of cysteine (Cys) residues in casein cross-linking. Casein proteins were subjected to photo-oxidation using visible light in the presence of a sensitizer (riboflavin or rose Bengal) and O2, then incubated with a Cys-containing peptide (glutathione, GSH) or protein (κ-casein), and subsequently analyzed by SDS-PAGE, immunoblotting and LC-MS. Our data indicate that that photo-oxidized (but not parent) caseins react efficiently with the Cys-containing species, likely via Michael addition to quinones formed from tyrosine residues to give glutathionylated species or protein adducts. Thus, oxidized α-casein reacts with native κ-casein to give high molecular mass aggregates. This adduct formation was prevented by alkylation of the Cys thiol group. The cross-link site and the residues involved have been confirmed by liquid chromatography-mass spectrometry (LC-MS) proteomic analysis. Together, these data extend our knowledge of the mechanisms involved in casein oxidation and aggregation.

Effect of Oral Administration of 3-Methylmorphine (Codeine) Induced Renal Toxicity in Adult Wistar Albino

Codeine (3-Methylmorphine) is the most common opiate consumed worldwide, it is widely used for its analgesic, antitussive and antidiarrheal activities. The study aims to determine the effect of oral administration of codeine induced renal toxicity in adult Wistar Albino Rats. Twenty albino rats weighing between 150-200g were used. Animals were divided into 4 groups (A, B, C and D). Group A served as the control group. Group B received 30mg/kg, group C received 60mg/kg and group D received 90mg/kg codeine orally for 28 days. Data obtained were calculated for one-way analysis of variance (ANOVA), followed by a Post Hoc test. Results were expressed as mean ± standard error of the mean. Statement of differences was based on significance level at p<0.05. The results showed a slight decrease in the mean values of Na+ , Cl- , and HCO3 – levels which are not significant, while K+ level showed an increase in group B and C followed by a decrease in group D which were not statistically significant (p<0.05). Creatinine level did not show any variation when compared with the control group but there was an increase in urea level which was also not statistically significant at p<0.05. Photomicrographs of rat’s kidneys in the treatment group showed; degeneration of the glomerulus, hydrophobic changes in the renal tubular lumen, fatty tissue, multi-focal interstitial haemorrhages, infiltration of inflammatory lymphoid cells, mild mononuclear cells infiltration in the renal cortex and mass aggregation of lymphoid cells in the cellular medullar when compared to control.

The Role of Wind and Semiochemicals in Mediating Switching Behavior in the Southern Pine Beetle (Coleoptera: Curculionidae: Scolytinae).

Aggressive bark beetles colonize and kill healthy conifers through pheromone-mediated mass aggregation. In several species, the focal point of aggregation moves progressively from mass-attacked 'focus trees' to adjacent, unattacked 'recipient trees', resulting in infestation growth. This process, termed 'switching', is hypothesized to be mediated in whole or in part by antiaggregation pheromones released by beetles as colonization intensifies on a focus tree. We tested this hypothesis with the southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae), by using a windvane apparatus that maintained an unbaited, black, cylindrical trap (surrogate for a recipient tree) continuously 4 m downwind from an identical trap baited with synthetic aggregation attractant (surrogate for a focus tree). In two of three replicated trials, addition of pheromone components with antiaggregation activity, endo-brevicomin or verbenone, to the upwind trap caused a significant but small (<15%) increase in the proportion of beetles caught in the downwind trap. In one of two trials with endo-brevicomin, this shift was associated with a significant reduction in catches in the downwind trap and an overall reduction in catches of beetles by the trap pair. This suggests that an inhibitor-induced increase in landings on the recipient relative to the focus tree may be countered by the radial effects of the inhibitor, which at sufficiently high release may reduce responses to both the focus and recipient tree. We discuss spatial factors that might govern the role of antiaggregation pheromones in stimulating infestation growth as well as additional factors that likely govern switching behavior.

The diet of a specialist nectarivore in Australia: The little red flying‐fox (Pteropus scapulatus, Pteropodidae)

AbstractThe little red flying‐fox (Pteropus scapulatus, Pteropodidae) is the most widely distributed of the four Australian mainland flying‐fox (Pteropus) species. They move very large distances following foraging resources and congregate in large numbers which often causes human‐animal conflict. To better understand the resources that drive these movements and aggregations, we investigated the diet of the little red flying‐fox using data from five sources: (i) faecal eDNA metabarcoding of field sampled little red flying‐foxes; (ii) identification of foraging locations through satellite tracking; (iii) a literature search; (iv) a search of online databases; and (v) an expert survey. Our sources revealed a specialist nectarivore diet containing 204 species, dominated by floral products from the plant family Myrtaceae. We consider a small number of widely occurring and structurally dominant Myrtaceae, particularly from the genera Corymbia, Eucalyptus and Melaleuca, as major diet species that regularly drive mass aggregations. In addition, we consider a moderate number of species dominated by the Myrtaceae as important diet species and a large number of species from diverse taxa as supplementary diet species. Fruit represents approximately 5% of the diet suggesting that the little red flying‐fox is unlikely to be a major pest of horticultural crops or disperser of weeds. The combination of long‐distance movement and a wide range of diet species results in a long‐distance pollination service to many plant species which likely promotes genetic mixing between isolated populations of plants. Our understanding of the little red flying‐fox diet allows us to better predict mass migrations and aggregations at a continental scale and allows us to clearly identify key foraging habitat so that informed management decisions can be made.

Synthesis, LC-MS/MS analysis, and biological evaluation of two vaccine candidates against ticks based on the antigenic P0 peptide from R. sanguineus linked to the p64K carrier protein from Neisseria meningitidis.

A peptide from the P0 acidic ribosomal protein (pP0) of ticks conjugated to keyhole limpet hemocyanin from Megathura crenulata has shown to be effective against different tick species when used in host vaccination. Turning this peptide into a commercial anti-tick vaccine will depend on finding the appropriate, technically and economically feasible way to present it to the host immune system. Two conjugates (p64K-Cys1pP0 and p64K-βAla1pP0) were synthesized using the p64K carrier protein from Neisseria meningitidis produced in Escherichia coli, the same cross-linking reagent, and two analogues of pP0. The SDS-PAGE analysis of p64K-Cys1pP0 showed a heterogeneous conjugate compared to p64K-βAla1pP0 that was detected as a protein band at 91kDa. The pP0/p64K ratio determined by MALDI-MS for p64K-Cys1pP0 ranged from 1 to 8, being 3-5 the predominant ratio, while in the case of p64K-βAla1pP0 this ratio was 5-7. Cys1pP0 was partially linked to 35 out of 39 Lys residues and the N-terminal end, while βAla1pP0 was mostly linked to the six free cysteine residues, to the N-terminal end, and, in a lesser extent, to Lys residues. The assignment of the conjugation sites and side reactions were based on the identification of type 2 peptides. Rabbit immunizations showed the best anti-pP0 titers and the highest efficacy against Rhipicephalus sanguineus ticks when the p64K-Cys1pP0 was used as vaccine antigen. The presence of high molecular mass aggregates observed in the SDS-PAGE analysis of p64K-Cys1pP0 could be responsible for a better immune response against pP0 and consequently for its better efficacy as an anti-tick vaccine. Graphical abstract

Transport and fluctuations in mass aggregation processes: Mobility-driven clustering.

We calculate the bulk-diffusion coefficient and the conductivity in nonequilibrium conserved-mass aggregation processes on a ring. These processes involve chipping and fragmentation of masses, which diffuse on a lattice and aggregate with their neighboring masses on contact, and, under certain conditions, they exhibit a condensation transition. We find that, even in the absence of microscopic time reversibility, the systems satisfy an Einstein relation, which connects the ratio of the conductivity and the bulk-diffusion coefficient to mass fluctuation. Interestingly, when aggregation dominates over chipping, the conductivity or, equivalently, the mobility of masses, is greatly enhanced. The enhancement in the conductivity, in accordance with the Einstein relation, results in large mass fluctuations and can induce a mobility-driven clustering in the systems. Indeed, in a certain parameter regime, we show that the conductivity, along with the mass fluctuation, diverges beyond a critical density, thus characterizing the previously observed nonequilibrium condensation transition [Phys. Rev. Lett. 81, 3691 (1998)10.1103/PhysRevLett.81.3691] in terms of an instability in the conductivity. Notably, the bulk-diffusion coefficient remains finite in all cases. We find our analytic results in quite good agreement with simulations.

Amphiphilic AxBy mikto‐arm star copolymers with PLMA and POEGMA arms: Self‐assembly and drug encapsulation

AbstractWe report on the synthesis and self‐assembly of amphiphilic mikto‐arm star copolymers of the AxBy type with mixed arms of poly(lauryl methacrylate) and poly(oligo ethylene glycol methacrylate). Two star copolymers with different hydrophobic‐to‐hydrophilic ratios are prepared in order to study their self‐assembly in aqueous media. Both stars organize in structures with dimensions in the nanoscale. The star with the lower hydrophobic content forms aggregates of lower size and molar mass and it has a higher critical aggregation concentration. The synthesized mikto‐arm stars are able to encapsulate curcumin (CUR) and preserve its fluorescence properties while their self‐organization is affected by the incorporation of the hydrophobic drug compound. Interestingly, the more hydrophilic star is more strongly affected by the presence of CUR in terms of aggregate size and mass. In phosphate buffered saline (PBS) and fetal bovine serum‐PBS solutions the star with higher hydrophobic content appears to better preserve its monomodal size distribution in comparison to the star with lower hydrophobic content either with or without encapsulated CUR. This work opens possibilities for using the new star copolymers in the solubilization of hydrophobic compounds and the delivery of hydrophobic drugs for pharmaceutical and bioimaging applications.

Mountain pine beetle: an example of a climate-driven eruptive insect impacting conifer forest ecosystems

Abstract Climate change is altering the survival and reproductive capacity of plant-feeding insects in multiple ecosystems worldwide, in some cases creating conditions highly suitable for population eruptions. Forest ecosystems are particularly sensitive to climate change as their vulnerability is manifested, in part, as an upsurge in natural disturbances such as native insect outbreaks. The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), is a phloem-feeding bark beetle indigenous to western North America that attacks most species of pine including its major hosts, lodgepole pine and ponderosa pine. Adult mass aggregation, mediated by pheromones, helps the beetle to overcome tree defenses eventually killing the tree. Recent outbreaks of this insect have caused extensive pine mortality and have affected millions of hectares of forested area in western North America. Climate is a major driver of these outbreaks. In this review, we describe the direct influences of various climate-related factors on MPB development, outbreak behavior, and range expansion and their indirect impact on MPB epidemiology via influences on host trees and MPB-associated fungi. We also underscore the ecological and economic consequences of the recent, unprecedented MPB outbreak. Of serious concern currently is whether climate change will facilitate rapid establishment and spread of MPB in naïve pine forests. MPB will likely adapt quickly to new thermal environments under climate change given its short generation time; however, uncertainties and gaps in our understanding of MPB population dynamics (e.g., trophic interactions) in newly invaded habitats preclude an accurate assessment of outbreak potential and spread at this time.

Conversion and outcome of dual antiplatelet therapy after bleeding in patients with acute coronary syndrome

Abstract Objective To explore the conversion and outcome of antiplatelet therapy in patients with acute coronary syndrome (ACS) who have suffered bleeding after receiving aspirin combined with ticagrelor. Methods Patients who diagnosed with ACS and given aspirin 100 mg once daily combined with ticagrelor 90 mg twice daily for dual antiplatelet therapy (DAPT) were selected. The patients were divided into bleeding group and non-bleeding group according to whether bleeding events occurred within one year after DAPT. The bleeding group was divided into the next four groups according to the converted antiplatelet treatment strategy decided by the doctor and the patient. Patients in group A to D were treated with ticagrelor 90mg twice a day plus aspirin 0–50mgonce a day, ticagrelor 60mg twice a day plus aspirin 100mgonce a day, clopidogrel 75mgonce a day plus aspirin 100mg once a day and ticagrelor 90mg twice a day plus aspirin 100mg once a day, respectively. All patients were followed up for 1 year after DAPT. The primary outcome is change of bleeding degree by BARC. The secondary outcomes includes BARC bleeding, all-cause mortality and MACE. Results A total of 752 cases were enrolled, including 250 in the bleeding group and 502 in the non-bleeding group. The bleeding group was divided into four treatment groups, which were 63, 43, 38 and 95 cases among A, B, C and D group. There was a significant difference in the improvement of bleeding among the four groups. To be noted, patients in group A has the highest improvement rate of hemorrhage (65.1% vs 62.8% vs 47.4% vs 24.2%, P&amp;lt;0.01). There were no significant differences in the incidence of MACE and all-cause mortality (P&amp;gt;0.05). The incidence of major MACE in patients in the bleeding group was 14.4%, which was higher than that in the non-bleeding group (9.2%, P=0.03).The result of multivariate logistic regression analysis showed that female (OR=5.18, 95% CI: 1.61–16.65, P=0.006), low body weight (OR=7.73, 95% CI: 2.46–24.49, P&amp;lt;0.001) and low AA-induced maximum platelet aggregation rate (OR=2.72, 95% CI:1.09–6.84, P=0.033) were independent risk factors for hemorrhage. Conclusion Patients with acute coronary syndrome who have suffered bleeding after receiving aspirin combined with ticagrelor were at a higher risk of MACE than those who did not. Low-dose aspirin (0–50mg/d) combined with ticagrelor or even ticagrelor alone has the best effect on reducing bleeding without increasing the risk of ischemia. Female, low body mass and low AA-induced maximum platelet aggregation rate are independent risk factors for bleeding. Funding Acknowledgement Type of funding source: None

Ophiuroids from the Middle Triassic (Muschelkalk) of Sadowa Góra, Jaworzno (southern Poland)

Ophiuroids belonging to Aspiduriella sp., Aspiduriella similis (Eck), and Arenorbis sp. are described from the Middle Triassic (Muschelkalk) strata of the Sadowa Góra Quarry (Jaworzno) in southern Poland. This is the only Polish location where three taxa of these ophiuroids have been found in one stratigraphic horizon (1st Wellenkalk). To date, only single taxa have been found in the Triassic sections of the eastern part of the Germanic Basin. Finally, other ophiuroid mass aggregations also known from Poland are presented.

Peroxynitrous acid (ONOOH) modifies the structure of anastellin and influences its capacity to polymerize fibronectin

Anastellin (AN), a fragment of the first type III module in fibronectin (FN), initiates formation of superfibronectin, a polymer which resembles the native cell-derived fibrillar FN found in the extracellular matrix of many tissues, but which displays remarkably different functional properties. Here we demonstrate that exposure of AN to the biologically-important inflammatory oxidant, peroxynitrous acid (ONOOH), either as a bolus or formed at low levels in a time-dependent manner from SIN-1, impairs the capability of AN to polymerize FN. In contrast, exposure of FN to ONOOH does not seem to affect superfibronectin formation to the same extent. This oxidant-induced loss-of-function in AN occurs in a dose-dependent manner, and correlates with structural perturbations, loss of the amino acid tyrosine and tryptophan, and dose-dependent formation of modified amino acid side-chains (3-nitrotyrosine, di-tyrosine and 6-nitrotryptophan). Reagent ONOOH also induces formation of oligomeric species which decrease in the presence of bicarbonate, whereas SIN-1 mainly generates dimers. Modifications were detected at sub-stoichiometric (0.1-fold), or greater, molar excesses of oxidant compared to AN. These species have been localized to specific sites by peptide mass mapping. With high levels of oxidant (>100 times molar excess), ONOOH also induces unfolding of the beta-sheet structure of AN, thermal destabilization, and formation of high molecular mass aggregates. These results have important implications for the understanding of FN fibrillogenesis in vivo, and indicates that AN is highly sensitive to pathophysiological levels of oxidants such as ONOOH.

When more data means better results: Abundance and scarcity in research collaborations in epigenetics.

Drawing upon ethnographic findings from an epigenetics research laboratory in the United Kingdom, this paper explores practices of research collaborations in the field of epigenetics, and epigenomics research consortia in particular. I demonstrate that research consortia are key scientific infrastructures that enable the aggregation of masses of data deemed necessary for the production of results and the fostering of epistemic value. Building on STS scholarship on value production, and the concept of asset, I show that the production of valuable research within epigenomics research consortia rests on the active organisation and management of abundance and scarcity. It involves shaping and standardising the masses of data gathered in consortia, while it also entails research teams enclosing their data within their laboratories' walls. As they do so, research teams construct data into scarce and monopolised assets, which they can put to productive use in collaborative endeavours against a revenue. In addition to contributing empirical and critical insights into the ways epigenetics knowledge is formed and negotiated in specific research contexts, this paper offers conceptual tools to examine and problematise knowledge production practices in data-intensive research more broadly. In particular, it points out that while contemporary big biology is marked by the generalised imperative to 'share' data and 'open' science, collaborative endeavours within research consortia are built around forms of exclusions.

Tasks and problems of the revival of domestic agricultural engineering

The problems of supplying the population with quality products in sufficient quantities still remain in the focus of attention of all mankind. The soil and climatic features of our country pose the most difficult tasks for the mechanization of the cultivation, harvesting and preservation of the products obtained in a highly competitive environment. At the same time, the role of agricultural machinery is increasing not only as mechanical assistants, but also as tools that directly affect the means of production - the soil, plants, microorganisms, crops, and the environment. Therefore, the issues of technical level and quality of work of mechanization can be compared in complexity only with the choice of cultivation technology. Hence, the ever-increasing pace of implementation of automation, robotization, hydraulic and electrification of structures. Digital controls are increasingly used for machine controls. However, the changes taking place in our country significantly slow down the pace of implementation of these trends. Imports of foreign technology, in most cases carried out without the appropriate regional tests, with orientation only on advertising indicators. As a result, there is a growing understanding that the import of foreign equipment does not replace domestic agricultural engineering in all cases. A paradoxical situation arises - the more we import imported equipment, the more the demand for domestic standardized and unified developments grows. The nomenclature of agricultural machinery is due to the natural features, multi-zone and multi-pattern agriculture, a large number of different crops, differences in the technologies of their cultivation, variability of working conditions, etc. It is formed by periodic «machine systems» based on the complexes and sets of machines within the relevant technologies. In addition, a number of long-term state programs for the stabilization and accelerated development of the industry are being developed and implemented on the basis of promising resource-saving technologies and criteria for the innovative development of the national economy. The domestic agricultural machinery industry must have a scientific and technical system for creating and maintaining new equipment - the GSKB network, mainly at the leading manufacturers and special design bureaus by types of main machines and their mass aggregates. The STC network of SHT «VISHOM» - GSKB - SKB - KB needs to be revived at an accelerated pace with the preparation of relevant personnel for it, taking into account the experience of active research and production activities of the special complex of the VISHOM.

Glow Discharge Plasma as a Cause of Changes in Aqueous Solutions: The Mass Spectrometry Study of Solvation Processes of Ions

A new apparatus for inducing changes in the properties of water in closed dielectric vessel by subjecting it to pulsed direct current glow discharge plasma is designed and constructed. It has been hypothesized that the action of plasma on the structure of water consists in resonance excitation of water aggregates. As a result of resonance excitation, aggregates of high molar masses are broken down into low molecular mass aggregates. Analysis of the ESI MS spectra revealed that in all tested aqueous solutions after exposure to plasma, the concentration of low-molecular solvated ions [M(H2O)]+ and [M(H2O)2]+ significantly increased, while the concentration of the ions of high molecular masses [M(H2O)6-10]+ solvated by water aggregates decreased, relative to their concentrations in the water solutions not subjected to plasma irradiation. According to our measurements also a significant change in pH occurs. The presented results clearly show that it is possible to process a liquid that changes its structure without involving high processing energy and, unexpectedly, the obtained change of parameters is significant and stable over time.

Управление плодородием лесных почв юго-восточной части Большого Кавказа на основе экологических моделей

The bloks which are a structural part of the ecological fertility model in the mountain-forest brown and mountain-forest brown soils on the south-eastern slope of the Great Caucasus besides an importance of the ecological models composition have been analyzed in the article. By the main purpose of the given investigations a creation of ecological models of fertility was mountain-forest brown soils (middle mountain broken) and mountainforest brown soils (low mountain (mean broken), interrelation and dependence of biocenosis condition on the environment factors are studied a role of the main parameters (climate, relief, soil and etc) is revealed, the real and optimal parameters of the environment are established for the ecological models blocks creation. The model consists of 7 (seven) blocks: agroecological block soil structure block, soil regimes block, soil features block. value block, agromelioration block and forests biometric block. During the model blocks compiling the main diagnostic indiced as a granulometric composition, humus quantity and supply, water suspension pH, NPK, bulky mass, porosity and water-stable aggregates (&gt; 0,25mm and &gt; 1,00mm) in the mountain-forest brown and mountain-forest brown soils have been taken into account. A comparative character of the ecological fertility models in two different soil types which are dominant in forest ecosystems has been given.

Associations of Brain Pathology Cognitive and Physical Markers With Age in Cognitively Normal Individuals Aged 60-102 Years.

The prevalence of brain pathologies increases with age and cognitive and physical functions worsen over the lifetime. It is unclear whether these processes show a similar increase with age. We studied the association of markers for brain pathology cognitive and physical functions with age in 288 cognitively normal individuals aged 60–102 years selected from the cross-sectional EMIF-AD PreclinAD and 90+ Study at the Amsterdam UMC. An abnormal score was consistent with a score below the 5th percentile in the 60- to 70-year-old individuals. Prevalence of abnormal scores was estimated using Generalized Estimating Equations (GEE) models. The prevalence of abnormal handgrip strength, the Digit Symbol Substitution Test, and hippocampal volume showed the fastest increase with age and abnormal MMSE score, muscle mass, and amyloid aggregation the lowest. The increase in prevalence of abnormal markers was partly dependent on sex, level of education, and amyloid aggregation. We did not find a consistent pattern in which markers of brain pathology cognitive and physical processes became abnormal with age.

A new approach for the separation, characterization and testing of potential prionoid protein aggregates through hollow-fiber flow field-flow fractionation and multi-angle light scattering

Protein misfolding and aggregation are the common mechanisms in a variety of aggregation-dependent diseases. The compromised proteins often assemble into toxic, accumulating amyloid-like structures of various lengths and their toxicity can also be transferred both in vivo and in vitro a prion-like behavior.The characterization of protein interactions, degradation and conformational dynamics in biological systems still represents an analytical challenge in the prion-like protein comprehension.In our work, we investigated the nature of a transferable cytotoxic agent, presumably a misfolded protein, through the coupling of a multi-detector, non-destructive separation platform based on hollow-fiber flow field-flow fractionation with imaging and downstream in vitro tests.After purification with ion exchange chromatography, the transferable cytotoxic agentwas analyzed with Atomic Force Microscopy and statistical analysis, showing that the concentration of protein dimers and low n-oligomer forms was higher in the cytotoxic sample than in the control preparation. To assess whether the presence of these species was the actual toxic and/or self-propagating factor, we employed HF5 fractionation, with UV and Multi-Angle Light Scattering detection, to define proteins molar mass distribution and abundance, and fractionate the sample into size-homogeneous fractions. These fractions were then tested individually in vitro to investigate the direct correlation with cytotoxicity. Only the later-eluted fraction, which contains high-molar mass aggregates, proved to be toxic onto cell cultures. Moreover, it was observed that the selective transfer of toxicity also occurs for one lower-mass fraction, suggesting that two different mechanisms, acute and later induced toxicity, are in place. These results strongly encourage the efficacy of this platform to enable the identification of protein toxicants.