PsicoQuilombologia: escrevivência de uma psicologia das encruzilhadas em tempos pandêmicos / PsychoQuilombology: writexperience of a psychology of crossroads in pandemic times / PsicoQuilombología: escrivivencia de una psicología de la encrucijada en tiempos pandémicos

O texto é um relato de experiência da participação no Grupo de Estudos psicoQuilombologia ocorrida nos meses de setembro de 2020 a março de 2021, período atravessado pela segunda onda da pandemia de COVID-19 no Brasil. O objetivo do relato é apresentar o conceito-movimento de psicoQuilombologia como uma proposta epistemológica quilombola de agenciamento de cuidado e saúde, com base em uma escuta que se faça descolonial e inspirada no fecundo e ancestral acervo de cuidado dos povos africanos, quilombolas e pretos, preservado e atualizado em nossos quilombos contemporâneos. A metodologia utilizada é a escrevivência, método desenvolvido por Conceição Evaristo que propõe uma escrita em que as vivência e memórias estão totalmente entrelaçadas, imersas e imbricadas com a pesquisa. O resultado das escrevivências dessa pesquisa descortinam que os povos pretos desenvolveram práticas de cuidado e acolhimento às vulnerabilidades do outro, enraizadas no fortalecimento de laços e conexões coletivas de afetos e cuidado mútuos. Práticas de cuidado que articulam memória, ancestralidade, tradição, comunidade, transformação, luta, resistência e emancipação, engendrando modos coletivos de ser e viver. Nas quais cuidar do outro implica tratar suas relações e situar o cuidado como extensão de uma cura que se agencia no coletivo. O trabalho conclui apontando que o cenário pandêmico vigente acentua a pungência de se desenvolver estratégias de cuidado baseadas em epistemologias pretas e quilombolas, valorizando os sentidos de ancestralidade, comunidade, pertencimento e emancipação.(AU)

The text is an experience report of the participation in the psicoQuilombology Study Group that carried out from September 2020 to March 2021, during the second wave of the COVID-19 pandemic in Brazil. The purpose of the report is to introduce the concept-movement of psicoQuilombology as a quilombola epistemological proposal for the development of care and health, based on a decolonial listening and inspired by the rich care collection of African peoples, quilombolas and Blacks, preserved and updated in our contemporary quilombos. The methodology used is writexperience [escrevivências], a method developed by Conceição Evaristo who proposes a writing in that the experiences and memories are totally involved with the research. The result of the writability of this research show that Black people have developed practices of care and acceptance of the other's vulnerabilities, based on the strengthening of ties and collective connections of mutual affection and care. Care practices that mix memory, ancestry, tradition, community, transformation, struggle, resistance and emancipation, outlining collective ways of being and living. The core idea is that taking care of the other means treating your relationships and maintaining care as an extension of a cure that takes place in the collective. The paper concludes by pointing out that the current pandemic scenario demonstrates the urgent need to develop care strategies based on black and quilombola epistemologies, valuing the senses of ancestry, community, belonging and emancipation.(AU)

Este es un reporte de experiencia de la participación en el Grupo de Estudio psicoQuilombología que ocurrió en los meses de septiembre de 2020 a marzo de 2021, periodo en que Brasil afrontaba la segunda ola de la pandemia de la COVID-19. Su propósito es presentar el concepto-movimiento de psicoQuilombología como una propuesta epistemológica quilombola para el desarrollo del cuidado y la salud, basada en una escucha decolonial e inspirada en el rico acervo asistencial de los pueblos africanos, quilombolas y negros, conservado y actualizado en nuestros quilombos contemporáneos. La metodología utilizada es la escrivivencia, un método desarrollado por Conceição Evaristo quien propone una escrita en que las vivencias y los recuerdos están totalmente involucrados con la investigación. El resultado de la escrivivencia muestra que las personas negras han desarrollado prácticas de cuidado y aceptación de las vulnerabilidades del otro, basadas en el fortalecimiento de lazos y conexiones colectivas de afecto y cuidado mutuos. Prácticas de cuidado que mezclan memoria, ascendencia, tradición, comunidad, transformación, lucha, resistencia y emancipación, perfilando formas colectivas de ser y vivir. El cuidar al otro significa tratar sus relaciones y mantener el cuidado como una extensión de una cura que tiene lugar en lo colectivo. El trabajo concluye que el actual escenario pandémico demuestra la urgente necesidad de desarrollar estrategias de atención basadas en epistemologías negras y quilombolas, y que valoren los sentidos de ascendencia, comunidad, pertenencia y emancipación.(AU)

Ancient genomes reveal tropical bovid species in the Tibetan Plateau contributed to the prevalence of hunting game until the late Neolithic.

Local wild bovids have been determined to be important prey on the northeastern Tibetan Plateau (NETP), where hunting game was a major subsistence strategy until the late Neolithic, when farming lifestyles dominated in the neighboring Loess Plateau. However, the species affiliation and population ecology of these prehistoric wild bovids in the prehistoric NETP remain unknown. Ancient DNA (aDNA) analysis is highly informative in decoding this puzzle. Here, we applied aDNA analysis to fragmented bovid and rhinoceros specimens dating ∼5,200 y B.P. from the Neolithic site of Shannashuzha located in the marginal area of the NETP. Utilizing both whole genomes and mitochondrial DNA, our results demonstrate that the range of the present-day tropical gaur (Bos gaurus) extended as far north as the margins of the NETP during the late Neolithic from ∼29°N to ∼34°N. Furthermore, comparative analysis with zooarchaeological and paleoclimatic evidence indicated that a high summer temperature in the late Neolithic might have facilitated the northward expansion of tropical animals (at least gaur and Sumatran-like rhinoceros) to the NETP. This enriched the diversity of wildlife, thus providing abundant hunting resources for humans and facilitating the exploration of the Tibetan Plateau as one of the last habitats for hunting game in East Asia.

Impact of magnetic fields generated by AC/DC submarine power cables on the behavior of juvenile European lobster (Homarus gammarus).

The number of submarine power cables using either direct or alternating current is expected to increase drastically in coming decades. Data concerning the impact of magnetic fields generated by these cables on marine invertebrates are scarce. In this context, the aim of this study was to explore the potential impact of anthropogenic static and time-varying magnetic fields on the behavior of recently settled juvenile European lobsters (Homarus gammarus) using two different behavioral assays. Day-light conditions were used to stimulate the sheltering behavior and facilitate the video tracking. We showed that juvenile lobsters did not exhibit any change of behavior when submitted to an artificial magnetic field gradient (maximum intensity of 200 µT) compared to non-exposed lobsters in the ambient magnetic field. Additionally, no influence was noted on either the lobsters' ability to find shelter or modified their exploratory behavior after one week of exposure to anthropogenic magnetic fields (225 ±â€¯5 µT) which remained similar to those observed in control individuals. It appears that static and time-varying anthropogenic magnetic fields, at these intensities, do not significantly impact the behavior of juvenile European lobsters in daylight conditions. Nevertheless, to form a complete picture for this biological model, further studies are needed on the other life stages as they may respond differently.

[Does Malnutrition during Fetal Life Have a Potential to Be a Precipitating Factor for Developmental Disorders?]

OBJECTIVES: The developmental origins of health and disease paradigm (DOHaD) is a concept that fetal environmental factors affect adult phenotypes. We performed experiments to evaluate the DOHaD theory in developmental disorders using mouse models. METHODS: In vitro fertilization and embryo transfer techniques were used for mouse production. The AIN93G-control diet, which contains 20% protein (CD), 5% protein-restricted diet (PR), and PR with supplemental folic acid (FA) were provided as experimental diets to mothers. The body weights (BWs) of mothers and offspring, and the blood-clinical biochemistry results of mothers were examined. In addition, gene expression and genomic methylation in the brain of adult offspring and behavioral phenotypes of adult offspring were examined. RESULTS: Pregnant mothers that consumed the protein-restricted diets, namely, PR and FA, exhibited reduction in BW. The values of protein-related parameters determined by blood-clinical biochemistry decreased in the PR fed groups. The BWs of neonates and adult offspring did not change. The offspring exposed to maternal hyponutrition exhibited increased activity in the home cage and enhanced fear and anxiety-like behavior. The adult offspring of the PR-fed group and FA-fed groups exhibited different patterns of mRNA expression and genomic methylation in the brain. CONCLUSIONS: The maternal PR diet affected the progenies' behavioral phenotypes and epigenetic outcomes in the brain. However, the behavioral changes induced by maternal protein restriction were very slight. Hence, interactions between several genetic factors and environmental exposures such as maternal malnutrition may cause developmental and psychiatric disorders.

Homing pigeons externally exposed to Deepwater Horizon crude oil change flight performance and behavior.

The Deepwater Horizon oil spill was the largest in U.S. history, contaminating thousands of miles of coastal habitat and affecting the lives of many avian species. The Gulf of Mexico is a critical bird migration route area and migrants that were oiled but did not suffer mortality as a direct result of the spill faced unpredictable fates. This study utilized homing pigeons as a surrogate species for migratory birds to investigate the effects a single low level external oiling event has on the flight performance and behavior of birds flying repeated 161 km flights. Data from GPS data loggers showed that lightly oiled pigeons changed their flight paths, increased their flight durations by 2.6 fold, increased their flight distances by 28 km and subsequently decreased their route efficiencies. Oiled birds also exhibited reduced rate of weight gain between flights. Our data suggest that contaminated birds surviving the oil spill may have experienced flight impairment and reduced refueling abilities, likely reducing overall migration speed. Our findings contribute new information on how oil spills affect avian species, as the effects of oil on the flight behavior of long distance free-flying birds have not been previously described.

Body mass change in flying homing pigeons externally exposed to Deepwater Horizon crude oil.

The Deepwater Horizon oil spill contaminated thousands of miles of habitat valuable to hundreds of species of migratory and resident birds of the Gulf of Mexico. Many birds died as a direct result of the oil spill; however, the indirect effects of oil exposure on the flight ability and body condition of birds are difficult to assess in situ. This study utilizes the homing pigeon as a surrogate species for migratory birds to investigate the effect of multiple external oil exposures on the flight performance and body mass change of birds over a series of repeated flights from 136.8km flight distance. Oiled pigeons took significantly longer to return home, lost more weight during flight, and were unable to recover their weight, resulting in reduction of body weight overtime. Based on our data, migratory birds that were oiled, even partially, by the Deepwater Horizon oil spill likely took longer to complete migration and were likely in poor body condition, increasing their risk of mortality and reproductive failure.

An Enriched Environment Promotes Shelter-Seeking Behaviour and Survival of Hatchery-Produced Juvenile European Lobster (Homarus gammarus).

The high loss of newly released hatchery-reared European lobster (Homarus gammarus) juveniles for stock enhancement is believed to be the result of maladaptive anti-predator behaviour connected to deprived stimuli in the hatchery environment. Our objective was to learn if an enriched hatchery environment enhances shelter-seeking behaviour and survival. In the "naïve" treatment, the juveniles were raised in single compartments without substrate and shelter whereas juveniles in the "exposed" treatment experienced substrate, shelter and interactions with conspecifics. Three experiments with increasing complexity were conducted. Few differences in shelter-seeking behaviour were found between treatments when one naïve or one exposed juvenile were observed alone. When observing interactions between one naïve and one exposed juvenile competing for shelter, naïve juveniles more often initiated the first aggressive encounter. The third experiment was set up to simulate a release for stock enhancement. Naïve and exposed juveniles were introduced to a semi-natural environment including substrate, a limited number of shelters and interactions with conspecifics. Shelter occupancy was recorded three times during a period of 35 days. Exposed juveniles occupied more shelters, grew larger and had higher survival compared with naïve juveniles. Our results demonstrate that experience of environmental complexity and social interactions increase shelter-seeking ability and survival in hatchery reared lobster juveniles.

Ordinary and Extraordinary Movement Behaviour of Small Resident Fish within a Mediterranean Marine Protected Area.

It is important to account for the movement behaviour of fishes when designing effective marine protected areas (MPAs). Fish movements occur across different spatial and temporal scales and understanding the variety of movements is essential to make correct management decisions. This study describes in detail the movement patterns of an economically and commercially important species, Diplodus sargus, within a well-enforced Mediterranean MPA. We monitored horizontal and vertical movements of 41 adult individuals using passive acoustic telemetry for up to one year. We applied novel analysis and visualization techniques to get a comprehensive view of a wide range of movements. D. sargus individuals were highly territorial, moving within small home ranges (< 1 km2), inside which they displayed repetitive diel activity patterns. Extraordinary movements beyond the ordinary home range were observed under two specific conditions. First, during stormy events D. sargus presented a sheltering behaviour, moving to more protected places to avoid the disturbance. Second, during the spawning season they made excursions to deep areas (> 50 m), where they aggregated to spawn. This study advances our understanding about the functioning of an established MPA and provides important insights into the biology and management of a small sedentary species, suggesting the relevance of rare but important fish behaviours.

Insect-inspired navigation algorithm for an aerial agent using satellite imagery.

Humans have long marveled at the ability of animals to navigate swiftly, accurately, and across long distances. Many mechanisms have been proposed for how animals acquire, store, and retrace learned routes, yet many of these hypotheses appear incongruent with behavioral observations and the animals' neural constraints. The "Navigation by Scene Familiarity Hypothesis" proposed originally for insect navigation offers an elegantly simple solution for retracing previously experienced routes without the need for complex neural architectures and memory retrieval mechanisms. This hypothesis proposes that an animal can return to a target location by simply moving toward the most familiar scene at any given point. Proof of concept simulations have used computer-generated ant's-eye views of the world, but here we test the ability of scene familiarity algorithms to navigate training routes across satellite images extracted from Google Maps. We find that Google satellite images are so rich in visual information that familiarity algorithms can be used to retrace even tortuous routes with low-resolution sensors. We discuss the implications of these findings not only for animal navigation but also for the potential development of visual augmentation systems and robot guidance algorithms.

Response, use and habituation to a mouse house in C57BL/6J and BALB/c mice.

Animal welfare depends on the possibility to express species-specific behaviours and can be strongly compromised in socially and environmentally deprived conditions. Nesting materials and refuges are very important resources to express these behaviours and should be considered as housing supplementation items. We evaluated the effects of one item of housing supplementation in standard settings in laboratory mice. C57BL/6JOlaHsd (B6) and BALB/cOlaHsd (BALB) young male and female mice, upon arrival, were housed in groups of four in standard laboratory cages and after 10 days of acclimatization, a red transparent plastic triangular-shaped Mouse House™ was introduced into half of the home cages. Animals with or without a mouse house were observed in various contexts for more than one month. Body weight gain and food intake, home cage behaviours, emotionality and response to standard cage changing procedures were evaluated. The presence of a mouse house in the home cage did not interfere with main developmental and behavioural parameters or emotionality of BALB and B6 male and female mice compared with controls. Both strains habituated to the mouse house in about a week, but made use of it differently, with BALB mice using the house more than the B6 strain. Our results suggest that mice habituated to the mouse house rather quickly without disrupting their home cage activities. Scientists can thus be encouraged to use mouse houses, also in view of the implementation of the EU Directive (2010/63/EU).

Impaired path integration and grid cell spatial periodicity in mice lacking GluA1-containing AMPA receptors.

The hippocampus and the parahippocampal region have been proposed to contribute to path integration. Mice lacking GluA1-containing AMPA receptors (GluA1(-/-) mice) were previously shown to exhibit impaired hippocampal place cell selectivity. Here we investigated whether path integration performance and the activity of grid cells of the medial entorhinal cortex (MEC) are affected in these mice. We first tested GluA1(-/-) mice on a standard food-carrying homing task and found that they were impaired in processing idiothetic cues. To corroborate these findings, we developed an L-maze task that is less complex and is performed entirely in darkness, thereby reducing numerous confounding variables when testing path integration. Also in this task, the performance of GluA1(-/-) mice was impaired. Next, we performed in vivo recordings in the MEC of GluA1(-/-) mice. MEC neurons exhibited altered grid cell spatial periodicity and reduced spatial selectivity, whereas head direction tuning and speed modulation were not affected. The firing associations between pairs of neurons in GluA1(-/-) mice were stable, both in time and space, indicating that attractor states were still present despite the lack of grid periodicity. Together, these results support the hypothesis that spatial representations in the hippocampal-entorhinal network contribute to path integration.

Helminths of wild hybrid marmosets (Callithrix sp.) living in an environment with high human activity / Helmintos de saguis (Callithrix sp.) híbridos de vida livre vivendo em ambientes com alta atividade humana

The objective of this study was to identify the helminth fauna in hybrid, non-native marmosets, through analysis of fecal samples. The study involved 51 marmosets (genus Callithrix) from five groups living in places with levels of human impact in Viçosa-MG. The marmosets were caught using a multiple-entrance trap and were anaesthetized. Feces were collected, refrigerated and analyzed by means of the sedimentation technique (Hoffmann-Pons-Janner). Eggs and parasites were identified, but not counted. Most of the marmosets (86%) were parasitized by at least one genus of helminths. Among the infected marmosets, 37% presented co-infection. The intestinal helminths comprised four different taxa: Primasubulura jacchi, Ancylostomatidae, Prosthenorchis sp. and Dilepididae.P. jacchi and Ancylostomatidae had higher prevalences (> 80% and > 40%, respectively) and were found in all marmoset groups. Dilepididae species were found in almost all the groups, but only accounted for around 30% of the marmosets. Prosthenorchis sp. showed a relatively low prevalence (< 10%) and was only found in one group. Although two parasites are commonly found in marmosets and other primates (P. jacchi and Prosthenorchis sp.), our study is the first record for Ancylostomatidae and Dilepididae. Factors like marmosets' feeding behavior and their contact with humans and other species of nonhuman primates seem to be determinants of infection among marmosets.

O objetivo do presente estudo foi a identificação da helmintofauna em saguis híbridos e introduzidos, por meio de análises de amostras fecais. O estudo envolveu 51 saguis do gênero Callithrix, de cinco grupos que ocupam áreas com diferentes impactos humanos. Os saguis foram capturados com armadilha de múltiplas entradas e anestesiados. Fezes foram colhidas, refrigeradas e analisadas pela técnica de sedimentação (Hoffmann-Pons-Janner). Ovos e parasitas foram identificados, mas não contados. A maior parte dos saguis (86%) estava parasitado por, pelo menos, uma espécie de helminto. Do grupo infectado, 37% apresentou coinfecção. A diversidade helmíntica intestinal incluiu quatro táxons diferentes: Primasubulura jacchi, Ancylostomatidae, Prosthenorchis sp. e Dilepididae. P. jacchi e Ancylostomatidae apresentaram as maiores prevalências (> 80% e > 40%, respectivamente) e foram encontrados em todos os grupos. As espécies de Dilepididae apresentaram aproximadamente 30% da prevalência e foram encontrados em quase todos os grupos. A espécie Prosthenorchis sp. apresentou prevalência relativamente baixa (< 10%) e foi encontrado somente em um grupo. Considerando que duas das espécies são parasitas comumente descritos para saguis e primatas (P. jacchi e Prosthenorchis sp.), este estudo consiste no primeiro registro para Ancylostomatidae e Dilepididae. Fatores como o comportamento alimentar e o contato com o homem e outras espécies de primatas não humanos, parecem ser determinantes na contaminação dos saguis.

Maternal genotype influences behavioral development of 3×Tg-AD mouse pups.

Transgenic mice are a valuable tool in the investigation of neurodegenerative disorders such as Alzheimer's disease. The triple transgenic mouse (3×Tg-AD) is a model of Alzheimer's disease that possesses age-related amyloid beta plaques, neurofibrillary tangles and cell death as well as cognitive decline. Because maternal effects may interact with pup genotype in determining behavior phenotypes, we used a cross-fostering paradigm to investigate the effects of maternal genotype on behavioral development of the 3×Tg-AD mouse model and its wildtype control (B6129S1F2) from 2 to 24 days of age. Developmental patterns of behavior were influenced by both pup and maternal genotype. The 3×Tg-AD mice were delayed in sensory reflexes, showed less activity and poorer habituation to a novel object, but showed advanced development of motor reflexes compared to wildtype pups. While there were no differences in levels of maternal care between transgenic and control mothers, maternal genotype affected the development of several pup reflexes (body weight, hindlimb grasp reflex, loss of crossed extensor reflex, vibrissae response, righting reflex) and the number of horizontal and vertical beam breaks in an open field. This study is the first to examine neurobehavioral development and maternal behavior in a mouse model of Alzheimer's disease, and highlights the importance of investigating the consequences of early environmental experience as well as genetic manipulation on behavioral development.

Path integration: how the head direction signal maintains and corrects spatial orientation.

Head-direction cells have frequently been regarded as an internal 'compass' that can be used for navigation, although there is little evidence showing a link between their activity and spatial behavior. In a navigational task requiring the use of internal cues to return to a home location without vision (path integration), we found a robust correlation between head-direction cell activity and the rat's heading error in the rat's homing behavior. We observed two different correction processes that rats used to improve performance after an error. The more frequent one consists of 'resetting' the cell whenever the rat returns to the home location. However, we found that when large errors occur, the head-direction system has the ability to 'remap' and set a new reference frame, which is then used in subsequent trials. We also offer some insight into how these two correction processes operate when rats make an error.

Effect of high dietary manganese intake of neonatal rats on tissue mineral accumulation, striatal dopamine levels, and neurodevelopmental status.

Mn is an essential element, but may become neurotoxic at high levels. Recent reports of high Mn levels in hair of children with neurodevelopmental deficits suggest that these deficits could be due to Mn-induced neurotoxic effects on brain dopamine (DA) systems, although the mechanism is not well understood. Infant formulas contain considerably higher concentrations of Mn than human milk. Thus, formula-fed infants are exposed to high levels of Mn at a time when Mn homeostasis is incompletely developed. We studied the effects of dietary Mn supplementation of rat pups on tissue Mn accumulation, brain dopamine levels, infant neurodevelopmental status, and behavior at maturity. Newborn rats were supplemented daily with 0, 50, 250, or 500 microg Mn given orally from day 1 to day 20. Mineral analysis of small intestine and brain at day 14 showed a significant increase of tissue Mn in supplemented rats. Neurodevelopmental tests conducted at various ages showed significant delays as a function of Mn supplementation. At day 32, there was a significant positive relationship between passive avoidance errors and Mn supplementation levels. Brains of animals killed on day 40 showed a significant inverse relationship between Mn supplementation level and striatal dopamine concentration. These observations suggest that dietary exposure to high levels of Mn during infancy can be neurotoxic to rat pups and result in developmental deficits.

Participation of the homing pigeon thalamofugal visual pathway in sun-compass associative learning.

The ascending thalamofugal visual pathway in pigeons (Columba livia) terminates in the telencephalic wulst. Characterizing the role of this pathway in visually guided behaviour has remained a challenge. To determine whether this pathway, and in particular the wulst, may participate in sun-compass-guided behaviour in homing pigeons, intact, ectostriatum-lesioned or wulst-lesioned pigeons were trained to use their sun compass to locate the direction of a food reward in an outdoor, octagonal arena. Control and ectostriatum-lesioned pigeons learned the task well, and orientated appropriately during the first trial of the last three training sessions and after a phase-shift manipulation. In contrast, the wulst-lesioned pigeons learned the task but they took more sessions to learn, and their directional choices were more scattered during the first trial of the last three training sessions and after the phase-shift manipulation. A subsequent regression analysis indicated that deeper layers of the wulst might have made more of a contribution to the observed behavioural impairments. The data indicate that the homing pigeon wulst participates in visually guided behaviour when the sun compass is used to learn the directional location of a goal.

Foraging behavior of bee pollinators on the tropical weed Triumfetta semitriloba: flight distance and directionality.

We studied flight distance and directionality of bee pollinators on the tropical shrub weed Triumfetta semitriloba Jacq. (Tiliaceae), addressing (1) within- and between-plant movement pattern; (2) distances flown between plants; (3) flight directionality. Flowering plants were distributed in well-delimited clumps, in each of two pasture areas (A1 and A2) and one area of forest gap (A3), in Viçosa, southeastern Brazil. Five solitary bee species, Augochlorella michaelis, Augochloropsis cupreola, Pseudocentron paulistana, Ceratinula sp., Melissodes sexcincta, and two social bee, Plebeia droryana, P. cf. nigriceps were observed. All species moved mainly to the nearest flower on the same individual plant and, in between-plant movements, to the first or second nearest neighbor. All species moved non-randomly, presenting a flight directionality in departures (maintenance of flight direction), but with a high frequency of turn angles. It is suggested that this foraging behavior pattern occurred because of the resource quantity and quality (pollen or nectar), and environmental characteristics such as flower density and resource distribution.

Superparamagnetic magnetite in the upper beak tissue of homing pigeons.

Homing pigeons have been subject of various studies trying to detect magnetic material which might be involved in magnetic field perception. Here we focus on the upper-beak skin of homing pigeons, a region that has previously been shown to contain nerves sensitive to changes of the ambient magnetic field. We localized Fe3+ concentrations in the subcutis and identified the material by transmission electronmicroscopy (TEM) as aggregates of magnetite nanocrystals (with grain sizes between 1 and 5 nm). The particles form clusters of 1-3 microm diameter, which are arranged in distinct coherent elongated structures, associated with nervous tissue and located between fat cells. Complementary low-temperature magnetic measurements confirm the microscopic observations of fine-grained superparamagnetic particles in the tissue. Neither electron-microscopic nor magnetic measurements revealed any single-domain magnetite in the upper-beak skin tissue.

Implications of the avian fauna for paleoecology in the Early Pleistocene of the Iberian Peninsula.

The aim of this paper is to reconstruct the landscape and climate during the formation of the Lower Pleistocene TD6 layer at Gran Dolina, Atapuerca. Habitat preferences and phenetic behavioural spectra of fossil birds are reconstructed using comparisons of fossil bird assemblages with modern avian communities. This method is based upon the phenology (seasonality and breeding status) of each species for both the fossil association and modern communities. The results indicate that more open country and wetter conditions prevailed during the early Pleistocene than were previously inferred.