Ecological Affinity Research Articles

Abstract A032: Cellos: High-throughput deconvolution of 3D organoid dynamics at cellular resolution for cancer pharmacology

Abstract Three-dimensional (3D) culture models, such as organoids, are flexible systems to interrogate cellular evolution, cellular growth and morphology, multicellular spatial architecture, and cell interactions in response to drug treatment. However, new computational methods to segment and analyze 3D models at cellular resolution with sufficiently high throughput are needed to realize these possibilities. Here we report Cellos (Cell and Organoid Segmentation), an accurate, high throughput image analysis pipeline for 3D organoid and nuclear segmentation analysis. Cellos segments organoids in 3D using classical algorithms and segments nuclei using a Stardist-3D convolutional neural network which we trained on manually annotated dataset of 3,862 cells. To evaluate the capabilities of Cellos we then analyzed 74,450 organoids with 1.65 million cells, from multiple experiments on triple negative breast cancer organoids containing clonal mixtures with complex cisplatin sensitivies. Cellos was able to accurately distinguish ratios of distinct fluorescently labeled cell populations in organoids, with < 3% deviation from seeding ratios in each well and was effective for both fluorescently labelled nuclei and independent Hoechst stained datasets. Cellos was able to recapitulate traditional luminescence-based drug response quantification by analyzing 3D images, including parallel analysis of multiple cancer clones in the same well. Moreover, Cellos was able to identify organoid and nuclei morphology features associated with treatment and unique to each of the clones. Finally, Cellos enables 3D analysis of cell spatial relationships, which we used to detect ecological affinity between cancer clones beyond what arises from local cell division and organoid composition. Cellos provides powerful tools to perform high throughput analysis for pharmacological testing and biological investigation of organoids based on 3D imaging. Citation Format: Patience Mukashyaka, Pooja Kumar, David J. Mellert, Shadae Nicholas, Javad Noorbakhsh, Mattia Brugiolo, Olga Anczukow, Edison T. Liu, Jeffrey H. Chuang. Cellos: High-throughput deconvolution of 3D organoid dynamics at cellular resolution for cancer pharmacology [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr A032.

High-throughput deconvolution of 3D organoid dynamics at cellular resolution for cancer pharmacology with Cellos

Three-dimensional (3D) organoid cultures are flexible systems to interrogate cellular growth, morphology, multicellular spatial architecture, and cellular interactions in response to treatment. However, computational methods for analysis of 3D organoids with sufficiently high-throughput and cellular resolution are needed. Here we report Cellos, an accurate, high-throughput pipeline for 3D organoid segmentation using classical algorithms and nuclear segmentation using a trained Stardist-3D convolutional neural network. To evaluate Cellos, we analyze ~100,000 organoids with ~2.35 million cells from multiple treatment experiments. Cellos segments dye-stained or fluorescently-labeled nuclei and accurately distinguishes distinct labeled cell populations within organoids. Cellos can recapitulate traditional luminescence-based drug response of cells with complex drug sensitivities, while also quantifying changes in organoid and nuclear morphologies caused by treatment as well as cell-cell spatial relationships that reflect ecological affinity. Cellos provides powerful tools to perform high-throughput analysis for pharmacological testing and biological investigation of organoids based on 3D imaging.

First biological inclusion in Upper Cretaceous Texas amber, USA

The first biological inclusion in Cretaceous (Cenomanian) amber from Texas (USA) is here documented. Most of the Cretaceous ambers with biological inclusions are from Europe (Spain, France) and Myanmar (Asia). Although the coleopteran here reported is microscopic and incomplete, it preserves enough morphological details to be identified as a member of the Family Ptinidae Latreille, 1802. This antecedent is significative and reveals the potential of this Cretaceous amber to contain more diverse bioinclusions, since the paleoenvironment suggested by the sediments that contain the amber and the ecological affinity of recent representatives of the Ptinidae suggest a humid forest near an estuary, associated to deltaic plain deposits. Este hallazgo representa la inclusión biológica en ámbar más antigua en las Americas.

Sea Surface Temperature Changes Reflected by Diatoms in the P6-10 Core from 1893 to 2013 from Prydz Bay, Antarctica

Identification and analysis was conducted on the diatoms from the 19 cm sediment of the P6-10 core, drilled from China’s 29th Antarctic Expedition, to attempt to semi-quantitatively reconstruct the annual sea surface temperature (SST) of Prydz Bay from 1893 to 2013. There were 30 species within the 12 genera of diatoms found, and the main contributors were Fragilariopsis curta, F. cylindrus, F. sublinearis, F. ritscheri, and Thalassiosira antarctica. They were divided into three categories based on their ecological affinity. The percentages of four specific species, i.e., F. curta, F. cylindrus, F. ritscheri, and F. separanda, which might be low SST indicators, were added together to represent the SST of Prydz Bay. With the help of cluster analysis, diatom assemblages were divided into diatom zones. Therefore, SST changes were divided into five stages by both the percentage of those four diatom species and the diatom zones: the high-temperature stage from 1893 to 1903, the cooling stage from 1903 to 1936, the stable and warm stage from 1936 to 1983, the low-temperature stage from 1983 to 1996, and the temperature rising stage from 1996 to 2013. On the multidecadal scale, SST change was affected by adjustments to solar radiation. On the contrary, the ENSO events mainly affected SST on the interannual scale. In addition, regarding the unique geographical environment (such as regional atmospheric circulation and a wind field) in Prydz Bay, volcanic eruptions and the like also played important roles in some exceptional periods.

Interspecific Growth Reductions Caused by Wild Ungulates on Tree Seedlings and Their Implications for Temperate Quercus-Fagus Forests

Ungulate impacts on forest understory alter tree species composition, with cascading effects on forest functions and resilience against future climate conditions. Indeed, the ungulate browsing pressure on tree seedlings is species-specific and causes contrasted growth reductions that alter tree recruitment rates. Untangling the effects of browsing from the effects of the other factors driving regeneration success is required to guide the forest and ungulate management. In particular, Fagus sylvatica L. strongly dominates temperate Quercus-Fagus forests close to their climax, and it remains unclear if controlling ungulate populations can maintain tree species diversity in naturally regenerated forests. We addressed this question by monitoring 734 pairs of fenced and unfenced 6-m2 plots across a broad gradient of Cervus elaphus L. abundance in Belgian Quercus-Fagus forests managed by continuous cover forestry. Seedling height, density, and vegetation cover were monitored from 2016 to 2021. Species diversity and ecological affinity for light, temperature, and atmospheric humidity conditions were computed from these measures. With ungulates, the mean growth of Betula pendula Roth. and Sorbus aucuparia L. was negligible, whereas, without ungulates, their growth was higher than the growth of other species. With ungulates, the growth of Fagus sylvatica L. and Picea abies (L.) H. Karst was higher than other species. Quercus (Quercus petreae (Matt.) Liebl and Quercus robur L.) growth was the lowest in all conditions. Finally, Carpinus betulus L. was heavily browsed but still grew higher than its competitors with ungulates. Ungulate browsing can then severely affect seedling growth and likely reduce the diversity of future recruited trees. In the study area, browsing unfavored the regeneration of the species that are less shade tolerant, more-drought tolerant, and more-heat tolerant. It thus accelerates the natural succession and reduces forest resilience to heat and drought events. Such an observation was found valid over a wide study area encompassing contrasting levels of Cervus elaphus L. abundance. Combining further reductions of ungulate populations with foodscape improvement is likely required to maintain species diversity in these forests.

Macrobenthos of the Tortolì Lagoon: A Peculiar Case of High Benthic Biodiversity among Mediterranean Lagoons

Coastal lagoons and brackish ponds are extremely dynamic and temporary ecosystems that follow natural changes throughout their geological history. The correct management of the lagoons ensures their integrity and proper functioning. For this reason, their ecological status should be surveyed for assessing the most appropriate strategies of use. In the present study, historical datasets collected in 2003–2004 are used to investigate the spatiotemporal variation in the species composition and community structure of the macrobenthos of the Tortolì Lagoon (Sardinia, Italy) and to assess their relationship with key environmental variables. Owing to the presence of a riverine runoff at a site and confined areas at some distance from the sea inlet, we hypothesize the marked spatiotemporal changes of the macrobenthic community consistent with the high environmental variability typical of coastal lagoons. The results show a surprisingly high benthic biodiversity for a medium-sized lagoon (250 ha), with 101 species unevenly distributed across the lagoon. The environmental variables did not explain the zonation of the macrobenthic community as that typically found along a lagoonal gradient, due to a marked marine influence. The sampling sites were in fact discriminated by the species distribution according to their ecological affinity; in particular, the most distinctive characteristics of the Tortolì Lagoon emerged from the strictly marine species that represented the most abundant group, consistently with the high marinization of the lagoon. Our results show that the Tortolì Lagoon constitutes a peculiar ecosystem within Mediterranean lagoons, departing from the classic confinement theory.

Abstract 186: Cellos: High-throughput deconvolution of 3D organoid dynamics at cellular resolution for cancer pharmacology

Abstract Three-dimensional (3D) culture models, such as organoids, are flexible systems to interrogate cellular growth, multicellular spatial architecture, and morphology in response to drug treatment, including the potential to resolve the individual behaviors and interactions of mixed cancer cell populations. However, new computational methods to segment and analyze 3D models at cellular resolution are needed to realize these possibilities. Here we report Cellos (Cell Organoid Segmentation), an accurate, high throughput image analysis pipeline for 3D organoid and nuclear segmentation analysis. Cellos segments 3D organoids using classical algorithms and segments nuclei using a Stardist-3D convolutional neural network trained on a manually annotated dataset of 3,862 cells from 36 organoids confocally imaged at 5 μm z-resolution. To evaluate the capabilities of Cellos, we then analyzed 74,450 organoids with 1.65 million cells from multiple experiments on triple negative breast cancer organoids containing clonal mixtures with complex cisplatin sensitivity. Cellos was able to accurately distinguish cell ratios in organoids in 96-well plates to within 2.99% and was effective for fluorescently labelled nuclei and independent DAPI stained datasets. Cellos was able to recapitulate traditional luminescence based drug responses by analyzing 3D images, including parallel analysis of multiple cancer clones in the same well. Moreover, Cellos was able to identify organoid and nuclear morphology feature changes associated with treatment. Finally, Cellos enables 3D analysis of cell spatial relationships, which we used to detect ecological affinity between cancer cells, beyond expectations from local cell division or organoid composition. Cellos provides powerful tools to perform high throughput analysis for pharmacological testing and biological investigation of organoids based on 3D imaging. Citation Format: Patience Mukashyaka, Pooja Kumar, Dave Mellert, Shadae Nicholas, Javad Noorbakhsh, Mattia Brugiolo, Olga Anczukow, Edison T. Liu, Jeffrey H. Chuang. Cellos: High-throughput deconvolution of 3D organoid dynamics at cellular resolution for cancer pharmacology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 186.

Status of local populations of protected species Psephellus marschallianus (Asteraceae) in the Stavropol region

Psephellus marschallianus is distributed in the steppe zone of Eastern Europe, in the North Caucasus only in the Stavropol region. This species has a narrow ecological affinity and can disappear when overgrown with stony substrates. Therefore, the work aimed at studying the state of local populations of P. marschallianus is of scientific interest and is relevant. Field studies were conducted according to the methods recommended for the study of rare species. Geobotanical descriptions are made according to generally accepted methods. The area, number and density of individuals were determined, and the ontogenetic structure was studied, which allowed us to characterize the state and prospects for the development of Psephellus marschallianus populations. For the first time, the state of the species was assessed according to the criteria of the International Union for Conservation of Nature (IUCN). The condition and structure of 5 local populyations of Psephellus marschallianus (ASTERACEAE), a protected species in the Stavropol Krai, has been studied. The area of the local populyations, number and density of individuals are determined, the ontogenetic structure, allowing to characterize a condition and the prospects of development of populyations of Psephellus marschallianus is studied. For the first time, an assessment of the condition of the species according to the criteria of the International Union for Conservation of Nature (IUCN) is given.

About this title - Applications of Non-Pollen Palynomorphs: from Palaeoenvironmental Reconstructions to Biostratigraphy

This long-awaited book about non-pollen palynomorphs (NPPs) aims to cover gaps in our knowledge of these abundant but understudied palynological remains. NPPs, such as fungal spores, testate amoebae, dinoflagellate cysts, acritarchs and animal remains, are routinely recovered from palynological preparations of marine or terrestrial material, from Proterozoic to recent geological times. This book gives the reader a comprehensive overview of the different types of NPPs, with examples from diverse time periods and environments. It provides guidance on sample preparation to maximize the recovery of these NPPs, detailed information on their diversity and ecological affinity, clarification on the nomenclature and demonstrates their value as environmental indicators. This volume will become the reference guide for any student, academic or practitioner interested in everything else in their palynological preparations.

Attachment to the Amazon Rainforest: Constitutive Aspects and their Predictors

Abstract This investigation aims to contribute to the understanding of the attachment to the Amazon rainforest and its predictors, considering the dimensions that characterize this extensive environment. Five instruments were administered to 333 individuals of both genders, over the age of 18, from the cities of Ceres and Manaus, evaluating the Ecological affinity profile; Attachment to the Amazon rainforest; Experiences in nature; Knowledge of the Amazon rainforest; and Socioeconomic factors. The results confirm that attachment depends on the length of stay in the place. Data shows that the ecological affinity profile plays an important role in the attachment to a natural environment, suggesting that this relationship is strengthened by understanding the characteristics of this environment and its experiences. Based on the perspective of Environmental Psychology, this study advances knowledge on place attachment predictors and provides important arguments for the development of pro-environmental interventions focused on emotional and experiential aspects.

Sharing and Distinction in Biodiversity and Ecological Role of Bryozoans in Mediterranean Mesophotic Bioconstructions

Bryozoan assemblages of three mesophotic habitats, recently found in the Adriatic and Ionian Seas, were investigated in terms of species composition and diversity, colonial growth forms, and species ecological affinity, with the purposes to analyze variations and similarities between the different bioconstructions and to compare the mesophotic assemblages with those of other benthic habitats. Bryozoans came from three sites off the Apulian coast: Monopoli, 30–55-m depth, where scleractinians are dominant; Otranto, 45–64-m depth; and Santa Maria di Leuca, 45–70-m depth, where the bivalve Neopycnodonte cochlear is the main bioconstructor. A total number of 50 species of bryozoans were recorded, accounting for about 10% of the total number of Mediterranean species. Only few species were shared between the three sites, whereas a considerable pool of species was characteristic of each site. The β-diversity and Sörensen similarity analyses highlighted the highest similarity between the two southern sites, Otranto and Santa Maria di Leuca, with respect to the northern site of Monopoli, in agreement with the hydrological pattern of the area. The encrusting zoarial type was the most abundant in each site, and few species with erect, celleporiform and petraliform colonies were found. The Sörensen similarity, based on data of zoarial forms composition, revealed values considerably higher than those based on species composition, thus highlighting the similar ecological role played by the bryozoans in all the sites. Moreover, significant differences between the mesophotic bryozoan assemblages and those of other benthic Mediterranean habitats were highlighted, showing higher affinity with the coralligenous and detritic sciaphilic habitats. The relevant ecological role of bryozoans as binders in the bioconstructions of the Mediterranean mesophotic zone has been exhibited.

Does evolutionary relatedness predict ecological similarity?

AbstractA fundamental question in paleobiology is whether ecology is correlated with evolutionary history. By combining time-calibrated phylogenetic trees with genus occurrence data through time, we can understand how environmental preferences are distributed on a tree and evaluate support for models of ecological similarity. Exploring parameters that lend support to each evolutionary model will help address questions that lie at the nexus of the evolutionary and ecological sciences. We calculated ecological difference and phylogenetic distance between species pairs for 83 taxa used in recent phylogenetic revisions of the brachiopod order Strophomenida. Ecological difference was calculated as the pairwise distance along gradients of water depth, carbonate, and latitudinal affinity. Phylogenetic distance was calculated as the pairwise branch length between tips of the tree. Our results show no relationship between ecological affinity and phylogeny. Instead results suggest an ecological burst during the initial radiation of the clade. This pattern likely reflects scaling at the largest macroevolutionary and macroecological scales preserved in the fossil record. Hierarchical scaling of ecological and evolutionary processes is complex, but phylogenetic paleoecology is an avenue for better evaluating these questions.

Distribución y ecología de medusas y sifonóforos en tres estaciones de la zona marino costera de la Península de Santa Elena, Ecuador

Con la finalidad de incrementar el conocimiento sobre los cnidarios se estudió la composición, distribución, abundancia y ecología de la comunidad de medusas y sifonóforos durante la época húmeda desde diciembre del 2015 a mayo del 2016 en seis estaciones ubicadas en la zona costera de Ancón, Anconcito y Punta Carnero (Ecuador), a partir de 51 muestras zooplanctónicas colectadas mediante arrastres superficiales y verticales. Se identificaron 22 especies de medusas clasificadas en 5 órdenes, 14 familias y 16 géneros y 14 especies de sifonóforos con 1 orden, 2 subórdenes, 4 familias y 10 géneros. Las especies más abundantes a nivel superficial fueron Aglaura hemistoma en febrero, Liriope tetraphylla en marzo, Obelia sp. y Proboscidactyla ornata en febrero, Nanomia bijuga en abril, Muggiaea atlantica en febrero, Sulculeolaria chuni y Diphyes dispar en marzo, mientras que en la columna de agua (10 metros) fueron Proboscidactyla ornata en febrero, Liriope tetraphylla, Solmundella bitentaculata, Obelia sp., Muggiaea atlantica y Nanomia bijuga en abril, la máxima diversidad en medusas fue de 2.14 bits/ind en la columna de agua para abril, mientras que en sifonóforos a nivel superficial con 1.67 bits/ind para diciembre. La similitud de Bray-Curtis determinó a las estaciones E2, E3 y E4 como las más afines por sus máximas abundancias. El análisis de correspondencia canónica destacó la relación entre Obelia sp. y Muggiaea atlantica con la temperatura y de Liriope tetraphylla con la salinidad. En general, la fauna de medusas y sifonóforos mostró una representativa afinidad ecológica para aguas tropicales y subtropicales así como también presencia de especies cosmopolitas, neríticas y oceánicas, estudio de vital importancia para asociarlos en futuras investigaciones al Evento El Niño.

Ceratozamia zaragozae Medellín-Leal (Zamiaceae), an endangered Mexican cycad: New information on population structure and spatial distribution

Ceratozamia zaragozae has been considered to be the most threatened cycad species in its genus since only 50 individuals were reported for the only known population in the state of San Luis Potosi, Mexico. In this report we present information on newly discovered populations, as well as data on their population structure and spatial distribution. Six different populations were found, one of which is located in a Natural Protected Area. Population density was low (0.05 ± 0.038 ind/m2) and populations exhibited an unconventional ecological affinity for the genus, occurring on igneous soils in oak and pine-oak forests at elevations over 2000 m. Populations showed heterogeneous growth rates (λ = 0.89 ± 0.49). Spatial clustering patterns in all populations indicated adequate recruitment, low survival of juveniles, and spatial dependence between seedlings/juveniles and reproductive adults. We recommend the ex-situ cultivation of the species and the establishment of corridors between areas of habitat, in order to secure the preservation of the species.

The enigmatic Palaeocene-Eocene coralline Distichoplax: Approaching the structural complexities, ecological affinities and extinction hypotheses

Abstract The alluring but scarcely understood Palaeocene-Eocene coralline alga Distichoplax has been examined in detail from multiple carbonate sections outcropping in Mawmluh near Cherrapunji (East Khasi Hills) in Meghalaya, N-E India. Despite having a wide geographical distribution Distichoplax still remains a mysterious taxon with faint knowledge pertaining to its evolution, ecology and causes of ultimate extinction. The commonly known feather-shaped and zipper-shaped cell arrangements need detailed reassessment considering the morphological intraspecific variability. The threefold objective of this paper is to analyse the complex cell/anatomical variations in Distichoplax, provide some insights into its ecological affinity, and most importantly propose hypotheses on the possible causes of its untimely demise in sharp contrast to other coralline algae distinguished by a long evolutionary record continuing to the present-day. The abundance of Distichoplax varies from monodominant assemblages to their co-dominance with geniculate coralline algae, non-geniculate Sporolithon and larger benthic foraminifera (orthophragminids) before facing sharp decline and ultimate extinction. Rare fairly well-preserved uniporate conceptacles and absence of cell fusions link Distichoplax to the subfamily Lithophylloideae of the family Corallinaceae. Very poor incidence of reproductive features, significant blooms of the species during the Thanetian (Late Palaeocene) and its eventual disappearance in the Eocene indicate Distichoplax may have been excessively dependent on vegetative propagation, and perished due to the climate adversities like the Palaeocene-Eocene Thermal Maximum (PETM) and biotic pressures like the Larger Foraminiferal Turnover (LFT).

Sediment type rules the response of aquatic plant communities to dewatering in wetlands

AbstractQuestionsThe effect of dewatering on aquatic plant communities may vary with sediment properties, such as particle size and organic matter content, as both control water retention in the sediment during dewatering. No study has tested how sediment type affects the short‐term response of plant communities to dewatering. We hypothesized that for the same dewatering event: (1) organic, silt and coarse sediments rank along a gradient of water deficit, with which community resistance and resilience decrease; (2) species survival during the event depend on their known ecological affinity for water; and (3) a peak in species richness associated with an intermediate water deficit occurs in silty habitats.LocationRiverine wetlands in the floodplain of the Ain River, France.MethodsEighteen sampling units were defined, set over three sediment types: gravel‐dominated coarse sediment, silt and organic matter‐dominated sediment. For each sediment type, three sampling units were permanently aquatic, and three sampling units underwent summer dewatering. A survey of species cover was conducted in each sampling unit at four times: before summer dewatering, at the beginning of the event, at the end of the event and 2 months after rewetting. Community resistance and resilience were assessed, as were changes over time in the proportions of species according their water affinity (hydrophytes, amphiphytes and helophytes, documented from the floras), and the effect of dewatering on species renewal and richness.ResultsThe sediment type affected aquatic plant community resistance and resilience, with increasing disturbance intensity for silty, followed by coarse compared with organic sediment. Organic sediment retained water efficiently during dewatering, supporting high community resistance, with the maintenance of amphiphytes and more tolerant hydrophytes. On silty sediment, disturbance was sufficiently high to cause the disappearance of hydrophyte vegetative parts, but propagules rapidly sprouted after rewetting, suggesting their preservation in the sediment and enabling good community resilience. On coarse sediment, a decrease in resident amphiphyte abundance, together with helophyte colonization and maintenance after rewetting were observed. Coarse sediment is not favourable to propagule survival, explaining the low community resilience. Contrary to our hypothesis, a linear positive relationship between disturbance intensity and species richness was observed after dewatering.ConclusionThe present study demonstrates that a simple description of sediment type allows prediction of dewatering impact on aquatic plant communities: organic, silt and coarse sediments were ranked along a gradient of water deficit, along which resistance and resilience decreased.

Civil society, corporate power, and food security: counter-revolutionary efforts that limit social change

Food is produced, processed, packaged, transported, and sold in a stable, organized system or food regime. The current food regime is focused on calories empty of substantial nutrition designed primarily for the growth of capital and corporate power, fostered through the lax, often corporate-designed, regulatory environment of neoliberalism. The neoliberal food regime is responsible for systemic malnutrition and erosion of the ecological preconditions for food production, as a regularity of the system itself. Consequently, a main line of food vulnerability is the political system that insulates the current food regime from social forces demanding change. This insecurity is contrary to the public or larger human interest, but this unsustainable system remains in place through a stable arrangement of government prescriptions that follow corporate-elite interests. To understand this structural problem, this essay examines the power of the food industry which requires the manufactured consent of civil society. The paper finds that counter-revolutionary efforts, which are anticipatory and reactive efforts that defend and protect capitalist elite from social change, stabilize the neoliberal food regime through covert tactics meant to undermine public interest critics and activists. As a result of these elite-led interventions, true civil society has become less powerful to articulate a public interest that might otherwise intercede in the operation and structure of the food regime. Thus, one leverage point in this political problem is the capacity of civil society, once it is independent of corporate interests, to remove consent to an abusive system and to debate and demand a food system that neither systematically starves whole groups of people nor destroys the ecological systems that make food possible. Building food security, then, requires recapturing a semi-autonomous civil society and eliminating domination of the corporate elite and replacing it with politics aligned with a public and ecological affinity. Scholars, educators, and the public can reduce the food vulnerability by becoming aware of corporate interests and creating strategic alliances to form a new system with more humane and ecological priorities.

PSICAMB – Perfil de Afinidade Ecológica: Um Estudo sobre os Indicadores da Postura perante a Natureza

The present study aimed to construct an ecological affinity profile and evaluate its relationship with the importance of the Amazon rainforest and with the consideration of the effect of human actions on nature. This study included 345 undergraduate students from the cities of Manaus-AM and Ceres-GO, male and female, over 18 years of age. The research instruments consisted of several scales that measured cognitive, affective and behavioral dimensions in relation to the Amazon rainforest and to nature as a whole. The results indicated that, when assessing the relations of affinity with nature, the beliefs regarding the natural environment and the consideration of future consequences, a structure can be identified that comprises an ecological affinity profile and a utilitarian profile.

A taxonomic tool for identifying needle remains of south-western EuropeanPinusspecies of the Late Quaternary

This work provides a tool whereby the needle remains of native, south-western European Pinus spp. can be easily identified from species-specific epidermal features. To construct this tool, the needles of P. uncinata, P. sylvestris, P. nigra, P. pinaster, P. pinea and P. halepensis were gathered across the Northern Hemisphere range of each taxon and compared with non-indigenous trees growing in two South Australian Botanic Gardens. Three needles from each of these species were taken from three adult trees growing at three different localities. Light microscopy was used to observe the key epidermal and stomatal features of the needles. To improve interpretation, additional scanning electron microscopy samples were prepared. Epidermal features, including variation in the diameter of the epistomatal chamber aperture (pore), are described. A taxonomic key based on the size, shape and arrangement of the subsidiary cells of the stomatal complexes was constructed. This key enables the identification of pine needle fragments at the species level (except those belonging to the group P. gr. nigra-uncinata). Despite their overlapping range, pore size was helpful in distinguishing between P. nigra and P. uncinata and between three groups of species. Isolated stomata were also observed. Cluster and discriminant analyses of stomatal variables described in earlier studies were performed. Overlap in guard cell variables hampers species-level identification of isolated stomata. Species discrimination is improved if groups of ecological affinity are considered. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 282–298.

Last Glacial Maximum age for the northwest Laurentide maximum from the Eagle River spillway and delta complex, northern Yukon

The Eagle River spillway and braid delta complex provide a record of the maximum extent of the northwest Laurentide Ice Sheet and diversion of meltwater from Bonnet Plume Basin into the interior basins of non-glaciated northern Yukon. Development of the spillway can be characterized in three distinct zones based on the distribution of erosion and deposition along each reach: erosion-dominated channel initiation and incision; followed by channelization and coarse clastic deposition along channel margins and into tributary valleys; and lastly, fine-grained deltaic and lacustrine sedimentation in the lower channel reach. Deltaic sedimentation within the spillway is crudely-coarsening upward from alternating beds of massive clay and silt to ripple-cross-bedded sand. All sediments occur in rapidly-aggrading forms with no evidence for a significant hiatus in deposition. Radiocarbon ages on woody plant macrofossils and spruce needles are non-finite, while radiocarbon ages on macrofossils from herbaceous plant taxa and insects with ‘steppe-tundra’ ecological affinity from the upper part of the delta range from 15 840 ± 90 to 21 600 ± 1300 14C yr BP. These ages, coupled with the rapidly-aggrading nature of the delta sediments and landform, suggest an age of ca 15–16 000 14C yr BP. Non-finite and mixed ages underscore the significant problem of reworked, well-preserved macrofossils in Arctic environments and the need for careful selection of both fragile and ecologically-representative macrofossils to establish reliable chronologies.