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result(s) for
"Keller, Roberto"
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Machine gun preacher
by
Chesse, Matt film editor
,
Schaefer, Roberto photographer
,
Forster, Marc, 1969- film director
in
Childers, Sam Drama
,
Drug traffic Drama
,
Sudan History Darfur Conflict, 2003- Drama.
2000
Sam Childers is a drug-dealing criminal who undergoes an astonishing spiritual transformation and makes a life-changing decision to travel to war-torn East Africa. After witnessing unspeakable horrors faced by innocent children, he vows to save them at any cost, including his own safety. Childers begins waging a relentless battle against the territory's renegade militia, leading harrowing missions behind enemy lines to rescue kidnapped orphans and restore peace to their lives and eventually his own.
Skeletomuscular adaptations of head and legs of Melissotarsus ants for tunnelling through living wood
by
Peeters, Christian
,
Khalife, Adam
,
Economo, Evan P.
in
Adaptation
,
Animal biology
,
Animal Physiology
2018
Background
While thousands of ant species are arboreal, very few are able to chew and tunnel through living wood. Ants of the genus
Melissotarsus
(subfamily Myrmicinae) inhabit tunnel systems excavated under the bark of living trees, where they keep large numbers of symbiotic armoured scale insects (family Diaspididae). Construction of these tunnels by chewing through healthy wood requires tremendous power, but the adaptations that give
Melissotarsus
these abilities are unclear. Here, we investigate the morphology of the musculoskeletal system of
Melissotarsus
using histology, scanning electron microscopy, X-ray spectrometry, X-ray microcomputed tomography (micro-CT), and 3D modelling.
Results
Both the head and legs of
Melissotarsus
workers contain novel skeletomuscular adaptations to increase their ability to tunnel through living wood. The head is greatly enlarged dorsoventrally, with large mandibular closer muscles occupying most of the dorsal half of the head cavity, while ventrally-located opener muscles are also exceptionally large. This differs from the strong closing: opening asymmetry typical of most mandibulated animals, where closing the mandibles requires more force than opening. Furthermore, the mandibles are short and cone-shaped with a wide articulatory base that concentrates the force generated by the muscles towards the tips. The increased distance between the axis of mandibular rotation and the points of muscle insertion provides a mechanical advantage that amplifies the force from the closer and opener muscles. We suggest that the uncommonly strong opening action is required to move away crushed plant tissues during tunnelling and allow a steady forward motion. X-ray spectrometry showed that the tip of the mandibles is reinforced with zinc. Workers in this genus have aberrant legs, including mid- and hindlegs with hypertrophied coxae and stout basitarsi equipped with peg-like setae, and midleg femura pointed upward and close to the body. This unusual design famously prevents them from standing and walking on a normal two-dimensional surface. We reinterpret these unique traits as modifications to brace the body during tunnelling rather than locomotion per se.
Conclusions
Melissotarsus
represents an extraordinary case study of how the adaptation to – and indeed engineering of – a novel ecological niche can lead to the evolutionary redesign of core biomechanical systems.
Journal Article
From Cabinet to Catalogue: The Palaearctic bee (Hymenoptera, Apoidea, Anthophila) collection of the Museu Nacional de História Natural e da Ciência, Universidade de Lisboa, Portugal
2026
The Mediterranean Basin, characterised by temperate rainy winters and hot dry summers, represents a notable hotspot for bee species richness. However, research on the bee fauna across this region remains uneven, with significant knowledge gaps in countries like Portugal. As human-driven climate change continues to cause a dramatic decline on insect species, museum records become indispensable for assessing changes in species distributions over time and to preserve material evidence about species for future generations.
We provide data on 5,295 bee records with Palaearctic distribution, collected from the 1920s to the year 2025. The collection, hosted in the Museu Nacional de História Natural e da Ciência (MNHNC), Universidade de Lisboa (UL), encompasses 425 species and 49 genera. The majority of the records originate from Portugal, including a newly-documented species for the country,
Morawitz, 1871, bringing the total number of bee species in mainland Portugal to 737. Type material held in the collection is documented and photographed here, alongside a record of bee types destroyed in the 1978 fire.
Journal Article
A never-ending story: updated 3D cyber-taxonomic revision of the ant genus Zasphinctus Wheeler (Hymenoptera, Formicidae, Dorylinae) for the Afrotropical region
by
Schurian, Bernhard
,
Economo, Evan P.
,
Hita Garcia, Francisco
in
Africa
,
Afrotropical region
,
Ants
2025
The ant genus Zasphinctus are fascinating ants due to their distinctive morphology, ecology, and rarity. In this study, a comprehensive revision of Zasphinctus in the Afrotropical region is presented, through a combination of morphological examination under the light microscope and three-dimensional (3D) cyber-taxonomy based on microtomography (micro-CT). Micro-CT based 3D surface models of all species were used for virtual morphological visualisation and examination. The 3D models were virtually visualised, rotated, scaled, and dissected in order to obtain the best shape data for whole specimens or individual body parts. This approach offered a greatly improved character evaluation, allowing the development of an updated taxonomic species delimitation system for the genus. Our revision recognises eight worker-based species, of which three were previously known and five are newly described in this study. Furthermore, based on distinctive morphological differences, two species groups are also proposed. The Z. obamai group includes the species Z. obamai Hita Garcia, 2017 (Kenya), Z. lumumbai Hita Garcia & Gómez, sp. nov. (Democratic Republic of Congo), and Z. wilsoni Hita Garcia, 2017 (Mozambique) while the Z. sarowiwai group contains Z. aprilia Hita Garcia & Gómez, sp. nov. (Democratic Republic of Congo, Uganda), Z. kouakoui Hita Garcia & Gómez, sp. nov. (Ivory Coast), Z. lolae Hita Garcia & Gómez sp. nov. (Ghana), Z. ndouri Hita Garcia & Gómez, sp. nov. (Senegal), and Z. sarowiwai Hita Garcia, 2017 (Cameroon). All species are easily distinguishable through a comprehensive character matrix illustrated by numerous diagnostic illustrations, as well as a traditional dichotomous identification key.
Journal Article
Evolution of thorax architecture in ant castes highlights trade-off between flight and ground behaviors
by
Keller, Roberto A
,
Beldade, Patrícia
,
Peeters, Christian
in
Adaptation, Physiological
,
Animal biology
,
Animals
2014
The concerted evolution of morphological and behavioral specializations has compelling examples in ant castes. Unique to ants is a marked divergence between winged queens and wingless workers, but morphological specializations for behaviors on the ground have been overlooked. We analyzed thorax morphology of queens and workers in species from 21 of the 25 ant subfamilies. We uncovered unique skeletomuscular modifications in workers that presumably increase power and flexibility of head–thorax articulation, emphasizing that workers are not simply wingless versions of queens. We also identified two distinct types of queens and showed repeated evolutionary associations with strategies of colony foundation. Solitary founding queens that hunt have a more worker-like thorax. Our results reveal that ants invest in the relative size of thorax segments according to their tasks. Versatility of head movements allows for better manipulation of food and objects, which arguably contributed to the ants’ ecological and evolutionary success. The size and shape of an animal, known as its morphology, often reflect the actions it can perform. A grasshopper’s long legs, for example, are well suited to hopping, whilst the streamlined body of a dolphin helps swimming through water. These specialized features result from the interplay between morphology and behavior during evolution. A change in morphology can make new behaviors possible, which can then expose the animal to new environments and selective pressures that, in turn, can lead to further changes in morphology. The interplay between morphology and behavior is particularly interesting in social insects such as ants. Queens and workers within an ant colony have a similar set of genes, but they have dramatically different morphologies and very different roles within the colony. Queens are responsible for reproduction, and are larger and have wings, which allow them to fly and establish a new colony away from where they were born. Workers are smaller and lack wings, and they devote themselves to building the nest, feeding the young larvae and protecting the colony. This marked morphological divergence, unique to ants, has fascinated researchers for more than a century. However, most studies have focused on the presence or absence of wings and have overlooked the interactions between morphology and the actions performed on the ground. Like all insects, an ant’s body is divided into three parts: the head, the thorax (to which the legs and wings are attached), and the abdomen. Now, Keller et al. have examined the shape of the thorax in many species of ants and found that workers are not just smaller wingless versions of queens: rather, the architecture of their thorax is unique among species of flying insects. The front end of the worker thorax is greatly enlarged and is filled by strong neck muscles that power the head and its jaws, and allow workers to hunt and carry prey many times their own weight. Keller et al. also identified two distinct types of queens and went on to show that these two shapes evolved in association with the two types of strategy that lone queens use to found new colonies. In species where queens convert their own wing muscles into the food for the first generation of workers, the wing muscles are much enlarged and the neck segment is extremely reduced. In species where queens hunt to feed the new colony, the wing and neck muscles are more balanced in size. As such, for those ant species where very little is known about how new colonies are founded, Keller et al. show that we can use the shape of the queen’s thorax to help predict this behavior. Taken together, the results of Keller et al. show that female ants invest in the relative size of the different segments of the thorax in a way that reflects their behavior as adults. These adaptations partly explain why ants have been so extraordinarily successful in nature, and underscore the importance of carefully analyzing an organism’s form to fully understand its biology.
Journal Article
Qualitative Differences in Attribution of Mental States to Other People in Autism and Schizophrenia: What are the Tools for Differential Diagnosis?
2022
The differential diagnosis between schizophrenia spectrum disorders (SSD) and autism spectrum disorders (ASD) remains an important clinical question, because they have overlap in clinical diagnosis. This study explored the differences between ASD (n = 44) and SSD patients (n = 59), compared to typically developing peers (n = 63), in completing an advanced Theory of Mind (ToM) task. The outcome found several differences between groups. The SSD patients showed greater difficulty in understanding social scenarios, while ASD individuals understood the stories, but did not correctly identify the protagonist’s intention. The interesting aspect of the results is that some ToM stories are more informative about the mentalistic reasoning of the two clinical groups, namely, the stories that investigate pretend, persuasion, double bluff and ironic joke constructs.
Journal Article
The loss of flight in ant workers enabled an evolutionary redesign of the thorax for ground labour
2020
Background
Explanations for the ecological dominance of ants generally focus on the benefits of division of labour and cooperation during foraging. However, the principal innovation of ants relative to their wasp ancestors was the evolution of a new phenotype: a wingless worker caste optimized for ground labour. Ant workers are famous for their ability to lift and carry heavy loads, but we know surprisingly little about the morphological basis of their strength. Here we examine the consequences of the universal loss of flight in ant workers on skeletomuscular adaptations in the thorax for enhanced foraging on six legs.
Results
Using X-ray microcomputed tomography and 3D segmentation, we compared winged queens and wingless workers in
Euponera sikorae
(subfamily Ponerinae) and
Cataglyphis savignyi
(subfamily Formicinae). Workers are characterized by five major changes to their thorax: i) fusion of the articulated flight thorax (queens) into a rigid box optimized to support the muscles that operate the head, legs and abdomen, ii) redesign of internal cuticular structures for better bracing and muscle attachment, iii) substantial enlargement of the neck muscles for suspending and moving the head, iv) lengthening of the external trochanter muscles, predominant for the leg actions that lift the body off the ground, v) modified angle of the petiole muscles that are key for flexion of the abdomen. We measured volumes and pennation angles for a few key muscles to assess their increased efficacy. Our comparisons of additional workers across five genera in subfamilies Dorylinae and Myrmicinae show these modifications in the wingless thorax to be consistent. In contrast, a mutillid wasp showed a different pattern of muscle adaptations resulting from the lack of wing muscles.
Conclusions
Rather than simply a subtraction of costly flight muscles, we propose the ant worker thorax evolved into a power core underlying stronger mandibles, legs, and sting. This contrasts with solitary flightless insects where the lack of central place foraging generated distinct selective pressures for rearranging the thorax. Stronger emphasis is needed on morphological innovations of social insects to further our understanding of the evolution of social behaviours.
Journal Article
Breaking the monotypy: Insights into an enigmatic ant genus with the discovery of Ishakidris hastifera sp. nov. in Peninsular Malaysia
2026
Ishakidris Bolton, 1984 is a monotypic ant genus, previously known only from a solitary specimen collected in Sarawak, Borneo. Unusual morphology of the genus has kept scientists intrigued since its description. Here we report on the discovery of Ishakidris hastifera sp. nov. from Peninsular Malaysia that provides important new insights into the taxonomy of this enigmatic genus and sheds light on its previously unknown diversity and distribution. We present a detailed account of the worker’s diagnostic features, aided by a micro-CT–based 3D model of the holotype, together with a cybertype dataset for the new species and an identification key for the genus. In addition, a 3D model of non-type material is made available for the already established species, Ishakidris ascitaspis Bolton 1984, using additional workers newly collected in Sabah, Borneo. Our analysis of both species’ internal structures, enabled by the 3D models, revealed a shelf-like invagination of the propodeum into the mesosomal cavity – an unprecedented character in ants. Using the morphological data, we discuss the support for the current systematic placement of the genus in Myrmicinae subfamily, or alternative hypothesis for Agroecomyrmecinae, that calls for molecular data to be yet tested.
Journal Article
Psychological Impact of COVID-19 Outbreak on Families of Children with Autism Spectrum Disorder and Typically Developing Peers: An Online Survey
by
Bianco, Federica
,
Keller, Roberto
,
Lecciso, Flavia
in
Anxiety
,
Autism
,
autism spectrum disorder
2021
Background: When COVID-19 was declared as a pandemic, many countries imposed severe lockdowns that changed families’ routines and negatively impacted on parents’ and children’s mental health. Several studies on families with children with autism spectrum disorder (ASD) revealed that lockdown increased the difficulties faced by individuals with ASD, as well as parental distress. No studies have analyzed the interplay between parental distress, children’s emotional responses, and adaptive behaviors in children with ASD considering the period of the mandatory lockdown. Furthermore, we compared families with children on the spectrum and families with typically developing (TD) children in terms of their distress, children’s emotional responses, and behavioral adaptation. Methods: In this study, 120 parents of children aged 5–10 years (53 with ASD) participated. Results: In the four tested models, children’s positive and negative emotional responses mediated the impact of parental distress on children’s playing activities. In the ASD group, parents reported that their children expressed more positive emotions, but fewer playing activities, than TD children. Families with children on the spectrum reported greater behavioral problems during the lockdown and more parental distress. Conclusions: Our findings inform the interventions designed for parents to reduce distress and to develop coping strategies to better manage the caregiver–child relationship.
Journal Article
Autism in Adulthood: Clinical and Demographic Characteristics of a Cohort of Five Hundred Persons with Autism Analyzed by a Novel Multistep Network Model
by
Chieregato, Silvia
,
Bari, Stefania
,
Keller, Roberto
in
adulthood
,
autism spectrum disorder
,
Care and treatment
2020
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in communication and relational skills, associated with repetitive verbal and motor behaviors, restricted patterns of interest, need for a predictable and stable environment, and hypo- or hypersensitivity to sensory inputs. Due to the challenging diagnosis and the paucity of specific interventions, persons with autism (PWA) reaching the adult age often display a severe functional regression. In this scenario, the Regional Center for Autism in Adulthood in Turin seeks to develop a personalized rehabilitation and enablement program for PWA who received a diagnosis of autism in childhood/adolescence or for individuals with suspected adulthood ASD. This program is based on a Multistep Network Model involving PWA, family members, social workers, teachers, and clinicians. Our initial analysis of 500 PWA shows that delayed autism diagnosis and a lack of specific interventions at a young age are largely responsible for the creation of a “lost generation” of adults with ASD, now in dire need of effective psychosocial interventions. As PWA often present with psychopathological co-occurrences or challenging behaviors associated with lack of adequate communication and relational skills, interventions for such individuals should be mainly aimed to improve their self-reliance and social attitude. In particular, preparing PWA for employment, whenever possible, should be regarded as an essential part of the intervention program given the social value of work. Overall, our findings indicate that the development of public centers specialized in assisting and treating PWA can improve the accuracy of ASD diagnosis in adulthood and foster specific habilitative interventions aimed to improve the quality of life of both PWA and their families.
Journal Article