Fragmentation Process Research Articles

The Effect of Cold-Water Swimming on Energy Metabolism, Dynamics, and Mitochondrial Biogenesis in the Muscles of Aging Rats.

Our study aimed to explore the potential positive effects of cold water exercise on mitochondrial biogenesis and muscle energy metabolism in aging rats. The study involved 32 male and 32 female rats aged 15 months, randomly assigned to control sedentary animals, animals training in cold water at 5 ± 2 °C, or animals training in water at thermal comfort temperature (36 ± 2 °C). The rats underwent swimming training for nine weeks, gradually increasing the duration of the sessions from 2 min to 4 min per day, five days a week. The results demonstrated that swimming in thermally comfortable water improved the energy metabolism of aging rat muscles (increased metabolic rates expressed as increased ATP, ADP concentration, TAN (total adenine nucleotide) and AEC (adenylate energy charge value)) and increased mRNA and protein expression of fusion regulatory proteins. Similarly, cold-water swimming improved muscle energy metabolism in aging rats, as shown by an increase in muscle energy metabolites and enhanced mitochondrial biogenesis and dynamics. It can be concluded that the additive effect of daily activity in cold water influenced both an increase in the rate of energy metabolism in the muscles of the studied animals and an intensification of mitochondrial biogenesis and dynamics (related to fusion and fragmentation processes). Daily activity in warm water also resulted in an increase in the rate of energy metabolism in muscles, but at the same time did not cause significant changes in mitochondrial dynamics.

Genetic consequences of landscape features in two rear edge, highly fragmented metapopulations of a mediterranean conifer

ContextHabitat fragmentation is expected to erode genetic diversity, which instead needs to be preserved for promoting species adaptation to a changing climate. As this expectation has found mixed support in forest trees, consistent results on the genetic consequences of fragmentation requires adequately replicated experimental designs, as well as an explicit assessment of which landscape features, if any, could mitigate its detrimental effects.ObjectiveEvaluating the role of several landscape attributes in buffering the detrimental effects of fragmentation in two metapopulations of silver fir.MethodsWe genotyped 904 silver fir (Abies alba Mill.) trees from 18 local populations forming two metapopulations comparable for size and extension in the Apennines, a Mediterranean mountain range. We identified the signatures left by the fragmentation process on the genetic features of silver fir local populations. After removing potentially confounding effects due to different evolutionary histories, we used a multivariate approach for testing the relative effect of demographic, geographic, environmental and topographic factors on genetic features of both metapopulations.ResultsWe found comparable signals of the habitat fragmentation impact on the genetic diversity and structure of both investigated metapopulations. Fragmentation effects were less pronounced in the largest local populations (but not the least isolated), located on gentler slopes with higher soil water availability and lower heat exposure.ConclusionsOur results suggest the existence of a set of demographic and environmental factors that could have coherently buffered the detrimental genetic effects of fragmentation in both metapopulations. These findings could be useful to plan landscape restoration for the evolutionary rescue of mixed forests that once characterized Mediterranean mountain ecosystems.

Physical Regimes and Mechanisms of Picosecond Laser Fragmentation of Gold Nanoparticles in Water from X-ray Probing and Atomistic Simulations.

Laser fragmentation in liquids has emerged as a promising green chemistry technique for changing the size, shape, structure, and phase composition of colloidal nanoparticles, thus tuning their properties to the needs of practical applications. The advancement of this technique requires a solid understanding of the mechanisms of laser-nanoparticle interactions that lead to the fragmentation. While theoretical studies have made impressive practical and mechanistic predictions, their experimental validation is required. Hence, using the picosecond laser fragmentation of Au nanoparticles in water as a model system, the transient melting and fragmentation processes are investigated with a combination of time-resolved X-ray probing and atomistic simulations. The direct comparison of the diffraction profiles predicted in the simulations and measured in experiments has revealed a sequence of several nonequilibrium processes triggered by the laser irradiation. At low laser fluences, in the regime of nanoparticle melting and resolidification, the results provide evidence of a transient superheating of crystalline nanoparticles above the melting temperature. At fluences about three times the melting threshold, the fragmentation starts with evaporation of Au atoms and their condensation into small satellite nanoparticles. As fluence increases above five times the melting threshold, a transition to a rapid (explosive) phase decomposition of superheated nanoparticles into small liquid droplets and vapor phase atoms is observed. The transition to the phase explosion fragmentation regime is signified by prominent changes in the small-angle X-ray scattering profiles measured in experiments and calculated in simulations. The good match between the experimental and computational diffraction profiles gives credence to the physical picture of the cascade of thermal fragmentation regimes revealed in the simulations and demonstrates the high promise of the joint tightly integrated computational and experimental efforts.

Video fragment processing by Ky Fan norm

In this study, we focused on the formalization of video frame descriptions in the context of solving video segmentation problem. Since native video data can have various sizes, dividing each frame into blocks allows present image frame as a square matrix for a formal description. The frame block is a matrix of arbitrary dimensions. The ability to skip the step of matrix transformation to a square dimension or vectorization using some descriptor allows to reduce computational costs, freeing up computational resources required for this transformation. In our study, we used Ky Fan norm value as image frame block descriptor. The Ky Fan norm is built on top of matrix singular values. A singular decomposition does not impose restrictions on either the dimension orthe character of the elements of the original matrix. We conducted a comparative analysis of the effectiveness of the obtained descriptor for different video data sizesand with different aspect ratios, showing that the change in the descriptor for each block is independent of the video sizeand aspect ratios. Changes in the descriptorsfor each block from frame to frame are identical for video data of varying sizes. This means that as a result of such fragment transform, a square matrix of a fixed size iscreated, regardless of the output video size.This makes it possible to unify further processing of the video, which can be useful for the task of information search in large video databases under the conditions of providing a query "ad exemplum". In thiscase, we can analyze the existing database in offline mode and match each video with a fixed square matrix of descriptors, which will significantly reduce the time and amount of resources when matching with the query. Also, this approach can be effectively used to analyze video data for the motion detection and scene change tracking.

High-speed photography and particle image velocimetry of cavitation in a Venturi tube

This article details the construction of an experimental visualization platform for observing cavitation. The platform uses high-speed photography and particle image velocimetry (PIV) techniques to conduct experimental research into the flow pattern and vortex field of cavitation in Venturi tubes. Dynamic mode decomposition is employed to extract the energy distribution characteristics of the cavitation flow field. Cavitation occurs at an exit-to-inlet pressure ratio of 0.595, and the length of the cavitation zone increases as this ratio decreases. When the pressure ratio reaches 0.280, the flow rate remains almost constant and the flow becomes chocked. The cavitation shape evolves periodically in the chocking flow, and the cavitation zone can be divided into three parts: an initiation and development area, a fusion area, and a collapse area. The fusion area exhibits periodic changes in the form of contraction, expansion, and re-contraction. Near the wall, the collapse area exhibits complex boundary conditions, with re-entrant jet causing bubble aggregation, rolling, and shedding. PIV and energy extraction reveal that vortices primarily appear near the wall, where they undergo a periodic process of fragmentation and fusion. The strength of the vortices exhibits a small–large–small pattern that is related to the cloud aggregation, rolling, and shedding caused by the re-entrant jet.

The territorial nature of the Primary Health Care of Brazil's Unified Health System (SUS): the proliferation of community medical clinics in the Metropolitan Region of Belém, State of Pará, Brazil

The scope of this article is an analysis of the proliferation of community medical clinics in the municipalities that comprise the Metropolitan Region of Belem. An investigation was conducted into the performance of the primary health care network of Brazil's Unified Health System, with a view to getting a better understanding of the reasons for, and origins of, the proactive stance of the community health sector. The discussion is based on the review of primary and secondary data, obtained via fieldwork in 119 community clinics in the Metropolitan Region of Belem, and information from Brazil's Unified Health System data center. It was revealed that the community health clinic sector has benefited extensively in recent years from the intensification of underfunding of Brazil's Unified Health System, especially the primary health care network, which is undergoing a process of fragmentation. This is directly responsible for the reduction and disruption of multiprofessional primary health care teams, in addition to the losses suffered in the supplementary health sector. The community clinics adopt an spontaneous and contradictory care model created by the private sector to meet the repressed demand of Brazil's Unified Health System.

Prevalence of elbow dysplasia in 13 dog breeds in France: a retrospective radiographic study (2002-2022).

To describe the prevalence of elbow dysplasia (ED) in 13 dog breeds in France. A total of 18,870 elbow radiographs taken from 2002 to 2022 were evaluated by 2 independent examiners. For each breed, the incidence of each of the 4 International Elbow Working Group scoring classes was extracted from the database. Breeds were excluded if fewer than 150 radiographs had been read for that breed. This study included 17,861 records for 13 dog breeds: American Akita, Alaskan Malamute, Old German Shepherd (Altdeutscher Schäferhund), American Staffordshire Terrier, Australian Shepherd, Belgian Shepherd, White Swiss Shepherd, Bernese Mountain Dog, Cane Corso, Czechoslovakian Wolfdog, Rhodesian Ridgeback, Rottweiler, and Dogue de Bordeaux. The overall prevalence of ED was 11.4%, ranging from 1.1% in the Czechoslovakian Wolfdog to 32.2% in the Dogue de Bordeaux. The Dogue de Bordeaux, Rottweiler, Bernese Mountain Dog, and Cane Corso breeds were most commonly affected by ED. The prevalence of ED was significantly higher in male dogs than in female dogs (17.5% vs 10.5%, P < .05). Joint incongruity and fragmented coronoid process were the 2 most common primary ED lesions identified. The prevalence of ED among the dogs evaluated decreased over the timeframe of the study. The results of this study help to clarify the prevalence of ED in different breeds in France. These data should be interpreted with caution as this study included a small percentage of the total number of dogs born for each breed in France over the study period.

Abstract 3909: PARG inhibitor sensitivity is correlated with accumulation of single strand DNA gaps in preclinical models of ovarian cancer

Abstract Poly (ADP-ribose) glycohydrolase (PARG) is a dePARylating enzyme which promotes DNA repair in conjunction with PARP1 by removal of poly (ADP-ribose) (PAR). Loss or inhibition of PARG results in replication stress and sensitizes cancer cells to DNA damaging agents, suggesting it is a potential therapeutic target for cancer therapy. Indeed, PARG inhibitors are now undergoing clinical development for patients having tumors with homologous recombination deficiency (HRD), such as ovarian and breast cancer patients with BRCA1/2-mutation. In this study, we investigated PARG inhibitor (PARGi)-PDD00017273 activity in preclinical models of ovarian cancer cell lines and primary patient-derived organoids. PARGi exhibited sensitivity in a subset of ovarian cancer cell lines that was distinct from PARP inhibitor sensitivity. Initially, we evaluated a PARGi-sensitive cell line, RMUGS. By gradually increasing the concentration of PARGi, we generated drug resistant cells. PARGi treatment resulted in increased S phase specific PAR, DNA-PARylation, DNA damage, and replication stress in the sensitive cells but not in cells with de novo or acquired resistance. In the sensitive cells, PARGi exposure also increased accumulation of PAR at the replication fork resulting from unligated Okazaki fragment processing. More importantly, PARGi treatment or PARG loss caused accumulation of single strand DNA (ssDNA) gaps in sensitive cells, as detected by the DNA fiber assays combined with S1 nuclease treatment. Regardless of the BRCA-status, the induction of ssDNA gaps in ovarian cancer cells correlated with PARGi sensitivity. Consistent with an increase in ssDNA gaps, PARGi exposure increased p-RPA, a ssDNA surrogate, at the replication fork in sensitive cells. p-RPA sites also colocalized with PAR suggesting that accumulation of PAR occurs at the ssDNA sites, perhaps, leading to the ssDNA gaps. Collectively, these results suggested that toxic accumulation of PAR at the replication fork leads to accumulation of ssDNA gaps due to Okazaki fragment processing defects and ovarian cancer cell killing after PARG inhibition. We further assessed PARG inhibition in patient-derived organoids (PDOs) and patient-derived xenograft (PDX)-derived organoids (PDXOs) as model systems of ovarian cancer. PARGi exhibited monotherapy activity in specific HR-deficient PDOs and PDXOs with BRCA1 or RAD51C mutation and in a HR-proficient PDXO model. Importantly, PARGi exposure resulted in accumulation of ssDNA gaps in organoids of ovarian cancer and this phenotype directly correlated with drug sensitivity. PDOs can therefore be a useful model system for testing PARGi sensitivity. The detection of ssDNA gaps in PDOs may provide a functional biomarker to predict the response to PARG inhibitors in clinical trials. Citation Format: Ramya Ravindranathan, Ozge Somuncu, Yuqing Jiao, Alexandre André B A da Costa, Benjamin P Lamarre, David B Martignetti, Gabriella A Zambrano, Sirisha Mukkavalli, Joyce Liu, Bose Kochupurakkal, Jean-Bernard Lazaro, Kalindi Parmar, Geoffrey I Shapiro, Alan D. D'Andrea. PARG inhibitor sensitivity is correlated with accumulation of single strand DNA gaps in preclinical models of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3909.

Synergic enhancement of ductility and toughness in friction stir additively fabricated AA6061-T6 build

This study comprehensively investigates the ductility and impact toughness aspects of friction stir additively fabricated (FSAF) components, particularly crucial for applications in aerospace components like stringers and stiffeners. FSAF technology is used to create a fifteen-layered AA6061-T6 build out of 3 mm thick aluminium sheets. A taper threaded tool with a pin length of 4.5 mm (corresponding to a plunge depth of 50% into the lower layer thickness) was used for the experiment. Dynamic recrystallisation resulted in the creation of a stir zone with fine grains, as demonstrated by optical microscopy. Differences in the size of grains, as well as alterations in the distribution, and size of precipitates were observed in the direction of fabrication. The hardness and tensile strength exhibited variations across layers, with the uppermost layer displaying the highest values (82.48 HV and 252.60 MPa, respectively). An impressive milestone was reached with the attainment of 66% ductility, primarily attributed to the process of fragmentation and partial reduction in grain boundary phases. The results of impact toughness have showcased a significant accomplishment as well. Impact tests yielded 112 J and 86 J for the crack-arrester and crack-divider orientations, with enhanced ductility playing a significant role. Delaminations in crack-arrester samples led to higher energy absorption.

Multiplicity correlation of fast target protons and projectile fragments for the events produced in the interaction of 84Kr nuclei with emulsion nuclei at 1 A GeV

It has become obvious that one crucial aspect in understanding high energy nuclear reactions is the fragmentation of colliding nuclei. The nuclear emulsion is a 4[Formula: see text] detector that makes it simple to identify and quantify the charges of projectile fragments. In this work, we study the multiplicity distribution and angle distributions of single, double charge projectile fragments, fast target protons (gray particle) as well as their correlation for the events produced in the interactions of [Formula: see text] with emulsion nuclei at 1[Formula: see text]A[Formula: see text]GeV. We also study the target-dependent angle distribution of gray particles. The results are compared with other experimental data as per availability. This analysis shows that multiplicity distributions have a remarkable link between the projectile and target fragmentation processes.

Qualitative and quantitative analysis of pesticide isomers based on collision-induced dissociation of high-resolution mass spectrometry

Pesticide isomers are widely present in agricultural production, while their biological activity, efficacy, and toxicity may vary significantly. Due to structural similarity, chromatographic and mass spectrometric analysis of isomeric pesticides are challenging. In this experiment, representative isomeric pesticides with great differences in toxicity and maximum residue limits among countries were studied. Based on collision-induced dissociation (CID) of high-resolution mass spectrometry, the fragmentation pathways of substituent position isomer, functional group position isomer, carbon frame isomer, functional group isomer, and cis–trans isomer were analyzed to attribute fragment ions. In addition, for the isomers with the same product ions and different abundance ratios, the abundance differences at different energy-resolved mass spectrometry were analyzed, which was combined with the computational chemical density functional theory to simulate the specific process of fragmentation and to explain the reasons for the differences in fragment ions and abundance ratios. Based on the above study, a high-resolution mass spectrometry method was established for the separation and analysis of pesticide isomers. Twelve pesticide isomers were distinguished by retention time, fragment ions, and relative abundance ratio. This method was applied to the detection of real fruit and vegetable samples.

Laser lithotripsy for pancreatic duct stones

Aim. To confirm the possibility of minimally-invasive laser procedure for fragmentation of stones in the pancreatic duct following the results of laboratory experiments and medical practice. Materials and methods. A fully functional hardware complex consisting of a pulsed laser unit, video endoscopic system and cooling system was created for experimental stone fragmentation in laboratory. The experiments involved microscopic video registration of the fragmentation process, pressure and temperature measurement in the stone area. Pancreatic stones, human and artificial gallstones as well as porcine pancreas were used in the experiments; the gastrointestinal tract was made of silicone, the pancreas was made of gelatin aqueous solution jelly. In clinical practice, a patient with lithiasis of Wirsung's duct was assigned to ultrasound and CT, then endoscopic papillosphincterotomy, endoscopic pancreatoscopy, laser lithotripsy and lithoextraction, pancreatic duct stenting. The procedures involved a laser unit, videoduodenoscope, catheter and their video systems. Results. The laboratory experiments established that effective and safe laser fragmentation of stones from 4 × 7 mm into 0.1–2 mm occurs in the flowing fluid in front of the stone at 1 μs laser pulse duration, 5–15 Hz frequency and 120–150 mJ laser energy. After laser fragmentation of the stone in a patient with virsungolithiasis and removal of fragments from the duct, the patient was discharged from the hospital on the 12th day due to improvement of healthcondition. Conclusion. The possibility of minimally-invasive fragmentation of stones in the pancreatic duct by laser lithotripsy has been proved.

Fragment-based drug design of novel inhibitors targeting lipoprotein (a) kringle domain KIV-10-mediated cardiovascular disease.

Cardiovascular diseases (CVDs) are the leading cause of death globally, attributed to a complex etiology involving metabolic, genetic, and protein-related factors. Lipoprotein(a) (Lp(a)), identified as a genetic risk factor, exhibits elevated levels linked to an increased risk of cardiovascular diseases. The lipoprotein(a) kringle domains have recently been identified as a potential target for the treatment of CVDs, in this study we utilized a fragment-based drug design approach to design a novel, potent, and safe inhibitor for lipoprotein(a) kringle domain. With the use of fragment library (61,600 fragments) screening, combined with analyses such as MM/GBSA, molecular dynamics simulation (MD), and principal component analysis, we successfully identified molecules effective against the kringle domains of Lipoprotein(a). The hybridization process (Breed) of the best fragments generated a novel 249 hybrid molecules, among them 77 exhibiting superior binding affinity (≤ -7kcal/mol) compared to control AZ-02 (-6.9kcal/mol), Importantly, the top ten molecules displayed high similarity to the control AZ-02. Among the top ten molecules, BR1 exhibited the best docking energy (-11.85kcal/mol ), and higher stability within the protein LBS site, demonstrating the capability to counteract the pathophysiological effects of lipoprotein(a) [Lp(a)]. Additionally, principal component analysis (PCA) highlighted a similar trend of motion during the binding of BR1 and the control compound (AZ-02), limiting protein mobility and reducing conformational space. Moreover, ADMET analysis indicated favorable drug-like properties, with BR1 showing minimal violations of Lipinski's rules. Overall, the identified compounds hold promise as potential therapeutics, addressing a critical need in cardiovascular medicine. Further preclinical and clinical evaluations are needed to validate their efficacy and safety, potentially ushering in a new era of targeted therapies for CVDs.

The functional significance of the RPA- and PCNA-dependent recruitment of Pif1 to DNA

Pif1 family helicases are multifunctional proteins conserved in eukaryotes, from yeast to humans. They are important for the genome maintenance in both nuclei and mitochondria, where they have been implicated in Okazaki fragment processing, replication fork progression and termination, telomerase regulation and DNA repair. While the Pif1 helicase activity is readily detectable on naked nucleic acids in vitro, the in vivo functions rely on recruitment to DNA. We identify the single-stranded DNA binding protein complex RPA as the major recruiter of Pif1 in budding yeast, in addition to the previously reported Pif1-PCNA interaction. The two modes of the Pif1 recruitment act independently during telomerase inhibition, as the mutations in the Pif1 motifs disrupting either of the recruitment pathways act additively. In contrast, both recruitment mechanisms are essential for the replication-related roles of Pif1 at conventional forks and during the repair by break-induced replication. We propose a molecular model where RPA and PCNA provide a double anchoring of Pif1 at replication forks, which is essential for the Pif1 functions related to the fork movement.

Specialized Laparoscopic Devices in the Treatment of Hydatic Hepatic Cysts: A Retrospective Analysis and Review of the Literature.

Background and objective While hydatid disease is associated with a high prevalence only in certain endemic areas, it can be encountered in any geographical region. The characteristics of this parasitic disease, and its implications during development, such as the risk of seeding, and the complications caused by cyst rupture, means that its therapeutic management should adhere to strict principles and may sometimes require approaches specially tailed for this type of pathology. In this study, we aimed to provide a comparative analysis of conventional laparoscopic techniques vs. treatment withspecialized instrumentation in these patients. Methods Our study involveda retrospective evaluationof a cohort comprising 41 patients diagnosed with hepatic hydatid cysts, who underwent procedures with both conventional laparoscopic techniques and specialized instrumentation tailored for this particular pathology. Furthermore, we conducted a comprehensive review of the literature examining alternative types of laparoscopic instrumentation specifically crafted for the management of hydatid cysts. This review employed an extensive search utilizing PubMed and Google Scholar databases. Results The examination of cases within our study revealed a high prevalence of hydatid disease among male patients (63.41%) and a predominance of instances originating from rural regions necessitating emergent admissions (p<0.05). Notably, in 58.54% of cases, surgical interventions employed specialized instrumentation, with a notable discrepancy in conversion rates to open surgery favoring the standard approach: 12.2% vs. 2.44% (p=0.025). Additionally, the laparoscopic approach was associated with prolonged surgical durations compared to the dedicated technique (p=0.002), besides a higher incidence of postoperative complications (12.2% vs 7.32%). Furthermore, patients undergoing laparoscopic procedures with standard instrumentation experienced lengthier hospital stays (p=0.002). Our comprehensive review of the literature identified six distinct surgical methodologies utilizing specifically tailored instrumentation for addressing hydatid cysts. Analysis of these findings underscored a preference for single localizations and selective cases. Postoperative complication rates ranged from 6.66% to 22.22%, with conversion rates to open surgery reaching up to 23.33%, and recurrence rates observed to be as high as 7.81%. Conclusions The patented approach, which uses special trocars that provide stable anchorage and allow a safe puncture-aspiration, reaspiration, and fragmentation processes, has superior characteristics compared to the laparoscopic approach with standard instrumentation. Comparative analysis with other similar procedures described in the literature has shown similar results regarding the frequency of complications, with our technique being superior in terms of approaching multiple cysts and recurrence rate. It has been successfully applied even in unselected cases.

Transverse Λ polarization in unpolarized pp → jet Λ↑ X

In this Letter, we investigate the spontaneous transverse polarization of Λ hyperons produced in unpolarized pp collisions inside a jet, by adopting a TMD approach where transverse momentum effects are included only in the fragmentation process. We will present predictions based on the parametrizations of the Λ polarizing fragmentation function as extracted from fits to Belle e+e− data. These estimates will be compared against preliminary STAR data. We will then be able to explore the universality properties of the quark polarizing fragmentation function and, for the first time, the role of its gluon counterpart.

Femtosecond laser shock peening Cu-Zn welds: Experiments and multi-scale modeling investigation

Laser shock peening of the weld surface is a cutting-edge treatment technology following welding. However, the conventional nanosecond pulsed lasers used for this process can unintentionally damage the weld surface quality due to secondary melting, which can reduce the comprehensive mechanical properties of the material. Here, we applied femtosecond laser shock peening (FLSP) to Cu-Zn welds as a paradigm. Experimental results show that FLSP cause the finer grain size on the surface of welds, with the maximum increases of approximately 17.6 % in surface hardness of the welds. The residual stress on the surface was transformed from tensile residual stress to compressive residual stress. Crucially, to provide a more precise depiction of the FLSP process, we developed a comprehensive multi-scale modeling approach that involves integrating the inputs and outputs among models with different scales. This multi-scale modeling approach provides an enhanced understanding of the FLSP process compared to traditional single scale models. The high-density electron pressure evolution process, the shock compression fragmentation process of the weld dislocation network during FLSP and the depth of compressive residual stress could be investigated by this model. These findings provide electronic-level and atomic-level insights and imply promising applications of FLSP on various welds surface.

Abundance and potential sources of floating polystyrene foam macro- and microplastics around Japan

Polystyrene foam is widely used due to its lightweight, impact resistance, and excellent thermal insulation properties. Meanwhile, weak adhesion between beads in polystyrene foam leads to fragmentation, generating a substantial amount of microplastics (<5 mm). Such polystyrene foam debris littered on beaches diminishes the aesthetic value of coastal areas, negatively impacting tourism. Due to its density lower than other plastics, polystyrene foam macroplastics float on the sea surface and, thus, they are significantly influenced by wind drag during oceanic transport. In contrast, polystyrene foam microplastics drifting beneath the sea surface are carried mostly by ocean currents. These properties of polystyrene foam macroplastics and microplastics hinder the elucidation of their transport, distribution, and fate in nature, despite their potential to adversely impact marine ecosystems. To elucidate the generation, transport, and fragmentation processes of polystyrene foam ocean plastics, we conducted concurrent visual observations and surface net towing from seven training vessels around Japan during 2014–2020. Overall, the abundances of polystyrene foam ocean plastics were higher in the Sea of Japan than in the North Pacific south of Japan. The average abundances of polystyrene foam microplastics and macroplastics were 0.33 pieces/m3 and 0.45 pieces/km, respectively, over the entire sea area around Japan. In the Sea of Japan, the peak abundances of polystyrene foam macroplastics occurred in upstream of the Tsushima Current, while the peak for microplastics occurred downstream, suggesting that continuous fragmentation occurred during transport between the two peaks. Backward-in-time particle tracking model experiments suggested that the sources of polystyrene foam macroplastics observed in the Sea of Japan included aquaculture buoys and styrene debris beached around the Tsushima Strait. The present study demonstrated that reducing the release of polystyrene foam aquaculture floats will likely diminish the abundance of ocean plastics in the Sea of Japan.

Finance, infrastructure and national space: from productive integration to the neoextractivist disintegration of the nation

Over the past five decades, the promotion of competitive spatial fragments linked to the primary-export sectors, herein called neoextractivist segments, has brought about a restructuring of the national space, generating a tendency toward a fragmentation of the national space. In this article, we contribute with a critical, updated reading of this fragmentation process of the national space, from an understanding of how the State, infrastructure, finance, and Neoextractivism have been articulated in the capitalist development both in general and in Brazil, thus revealing new dynamics and structures of territorial control and wealth extraction. The agents linked to these dynamics and structures have formed a neoextractivist coalition of disintegration that acts to operate in maintaining and broadening primary-export activities, thereby reinforcing the nation's tendency toward fragmentation.

How do different processes of habitat fragmentation affect habitat quality? – Evidence from China

Large-scale loss and fragmentation of natural habitats is one of the critical factors in the global decline of biodiversity. Habitat quality is the foundation for supporting biodiversity, so exploring the mechanisms by which habitat fragmentation affects habitat quality is important for biodiversity protection. However, little is known about the specific forms that various processes of habitat fragmentation affect habitat quality. Taking China as an example, the three processes of habitat fragmentation (the decrease in habitat area, the increase in habitat isolation, and the increase in habitat edge) and variations in habitat quality were quantitatively assessed from 2000 to 2020. On this basis, Pearson coefficients, Generalized Additive Model (GAM) and Geographical detector were employed to examine the linear\ on-linear\\combined impacts of habitat fragmentation different processes on habitat quality. The results indicated that there was a clear trend of habitat fragmentation and degradation of habitat quality in 2000–2020. 56.94%, 42.33%, and 50.89% of the area experienced the decrease in habitat area, the increase in habitat isolation, and the increase in habitat edge, respectively, and 63.12% experienced degradation of habitat quality. All three of these habitat fragmentation processes result in a downward trend in habitat quality. However, the specific form of impacts of habitat fragmentation different processes on habitat quality showed non-linear characteristics. The decrease in habitat area and the increase in habitat isolation consistently had a significant negative influence on habitat quality, albeit with varying strengths at different segments. While the increase in habitat edge causes an overall decrease in habitat quality, the two have a more complex non-linear relationship, with response curves varied between positive and negative correlations. In addition, negative impacts on habitat quality are exacerbated when multiple habitat fragmentation processes occur simultaneously. These findings reveal the complex impacts of different habitat fragmentation processes on habitat quality and inform the development of more rational landscape planning and biodiversity conservation measures in China.