Understanding How Microplastics Affect Marine Biota on the Cellular Level Is Important for Assessing Ecosystem Function: A Review

Plastic has become indispensable for human life. When plastic debris is discarded into waterways, these items can interact with organisms. Of particular concern are microscopic plastic particles (microplastics) which are subject to ingestion by several taxa. This review summarizes the results of cutting-edge research about the interactions between a range of aquatic species and microplastics, including effects on biota physiology and secondary ingestion. Uptake pathways via digestive or ventilatory systems are discussed, including (1) the physical penetration of microplastic particles into cellular structures, (2) leaching of chemical additives or adsorbed persistent organic pollutants (POPs), and (3) consequences of bacterial or viral microbiota contamination associated with microplastic ingestion. Following uptake, a number of individual-level effects have been observed, including reduction of feeding activities, reduced growth and reproduction through cellular modifications, and oxidative stress. Microplastic-associated effects on marine biota have become increasingly investigated with growing concerns regarding human health through trophic transfer. We argue that research on the cellular interactions with microplastics provide an understanding of their impact to the organisms’ fitness and, therefore, its ability to sustain their functional role in the ecosystem. The review summarizes information from 236 scientific publications. Of those, only 4.6% extrapolate their research of microplastic intake on individual species to the impact on ecosystem functioning. We emphasize the need for risk evaluation from organismal effects to an ecosystem level to effectively evaluate the effect of microplastic pollution on marine environments. Further studies are encouraged to investigate sublethal effects in the context of environmentally relevant microplastic pollution conditions

An in-vivo study exploring correlations between early-to-moderate disc degeneration and flexion mobility in the lumbar spine

Purpose: Early disc degeneration (DD) has been thought to be associated with loss of spine 6 stability. However, before this can be understood in relation to back pain, it is necessary to 7 know the relationship between DD and intervertebral motion in people without pain. This 8 study aimed to find out if early to moderate DD is associated with intervertebral motion in 9 people without back pain. 10 Methods: Ten pain free adults, aged 51-71 received recumbent and weight bearing MRI 11 scans and quantitative fluoroscopy (QF) screenings during recumbent and upright lumbar 12 flexion. Forty individual level and 10 composite (L2-S1) radiographic and MRI DD gradings 13 were recorded and correlated with intervertebral flexion ROM, translation, laxity, and 14 motion sharing inequality and variability for both positions. 15 Results: Kinematic values were similar to previous control studies. DD was evidenced up to 16 moderate levels by both radiographic and MRI grading. Disc height loss correlated slightly, 17 but negatively with flexion during weight bearing flexion (R=-0.356, p=0.0.025). Composite 18 MRI DD and T2 signal loss evidenced similar relationships (R= -0.305, R= -0.267) but did not 19 reach statistical significance (p=0.056, p=0.096). No significant relationships between any 20 other kinematic variables and DD were found. 21 Conclusion: This study found only small, indefinite associations between early-to-moderate 22 DD and intervertebral motion in healthy controls. Motion sharing in the absence of pain 23 was also not related to early DD, consistent with previous control studies. Further research 24 is needed to investigate these relationships in patients. 25 Key words: back pain, disc degeneration, instability, imagin

Chemometric analysis of functional groups in fossil remains of the Dicroidium flora (Cacheuta, Mendoza, Argentina): Implications for kerogen formation

Studied samples include eight Gondwanan species of the Dicroidium flora: seed ferns (3), conifer (1), cycad-related (1), unknown affinity gymnosperms (2), and one undetermined axis from two Middle to Upper Triassic localities (Cacheuta, Mendoza, central western Argentina). Based on differing preservation states and sample treatments, four sample forms are established: (1) compressions, (2) cuticles, (3) cuticle-free coalified layers, and (4) associated coal samples. The purpose of the study is firstly to analyze the sample forms using Fourier transform infrared (FTIR) spectrometry, contributing to filling an existing gap of chemical information for Gondwanan pant fossil remains. Secondly, semi-quantitative chemical parameters, calculated by area integration of infrared spectra, are treated using principal component analysis to infer statistical groupings as a function of chemical structures (functional groups). From the initial two-component solution, based on the 8×41 data matrix, a subset matrix (4×29) could be isolated which also yielded a two-component solution (in each case, cumulative explained variance is at least 89%). Results include the distinction between the coaly forms (1) compressions and (3) cuticle-free coalified layers mainly based on the carbonyl contents and branching and length of the hydrocarbon side chains. The highly aliphatic nature of cuticles, which is indicative of biomacromolecules (cutin), is noted. Similarities in functional groups are recorded with types of kerogen and coal macerals. The result enables us to postulate that the functional groups characterizing the different modes of preservation of our fossil remains are likely related to the propensity to generate oil and gas/condensate from the kerogen. Our data have the potential for future studies with implications for chemotaxonomy, molecular taphonomy, and paleoclimatology.Fil: José A. D'Angelo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA)-CCT-CONICET-Mendoza; ArgentinaFil: Escudero, Leticia Belén. Grupo de Investigación y Desarrollo en Química Analítica (QUIANID), (LISAMEN-CCT-CONICET-Mendoza) ; ArgentinaFil: Volkheimer, Wolfang. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA)-CCT-CONICET-Mendoza; ArgentinaFil: Erwin L. Zodrow. Palaeobotanical Laboratory, Cape Breton University, Sydney, Nova Scotia, Canada; Canad

Stratigraphy, facies analysis and paleoenvironments of the Cañadón Asfalto Formation, Jurassic Cerro cóndor depocenter, Chubut province

The Cerro Cóndor depocenter represents the most complete stratigraphic sequence of the continental Jurassic of the Cañadón Asfalto basin and southern South America. It is situated in extraandean Patagonia, on both sides of the middle Chubut river valley. The sedimentation in this pull-apart basin begins early in the Middle Jurassic, accompanied by effusions of olivinic basalts. The prevailing lacustrine deposits are characterized by carbonatic and siliciclastic facies associations, interfingering with volcanic deposits grading from lavic in the base to predominantly pyroclastic towards the top. The facies evolution from north to south is described, embracing the sections of farm El Torito and the canyons of Los Loros, Las Chacritas, Carrizal, Asfalto and Lahuincó. The carbonatic facies/microfacies are represented by mudstones, wackestones, packstones, grainstones and microbialitic limestones, characteristic of littoral/marginal and palustrine environments. In the Cañadón Asfalto Formation are distinguished a lower member (Las Chacritas composed by limestones, shales, sandstones and conglomerates intercalated with olivinic basalts, and an upper member (Puesto Almada) composed by tuffs, tuffites, shales and sandstones. The first is bearing a palynologic assemblage of Bajocian-Bathonian age and the second dinosaurs of Tithonian age. The stratigraphic sections of both members of the formation are described and illustrated at their type localities cañadón Las Chacritas and farm El Torito and the paleoenvironments of the depocenter, from the Aalenian to the Tithonian are described and illustrated. The age of the Puesto Almada Member at its type locality was obtained by radiometric dating (K/Ar) of biotites from a thin layer of volcanic tuff (147.1 + 3.3 Ma, Tithonian) from the upper part of the unit.Fil:Cabaleri, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Armella, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Silva Nieto, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Cagnoni, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Ramos, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Panarello, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Koukharsky, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina