A multi-agent system model to integrate Virtual Learning Environments and Intelligent Tutoring Systems

Virtual learning environments (VLEs) are used in distance learning and classroom teaching as teachers and students support tools in the teaching–learning process, where teachers can provide material, activities and assessments for students. However, this process is done in the same way for all the students, regardless of their differences in performance and behavior in the environment. The purpose of this work is to develop an agent-based intelligent learning environment model inspired by intelligent tutoring to provide adaptability to distributed VLEs, using Moodle as a case study and taking into account student's performance on tasks and activities proposed by the teacher, as well as monitoring his/her study material access

Posterior arch defect of the atlas associated to absence of costal element of foramen transversarium from 16th century Sardinia (Italy)

Study Design. A paleopathological case of posterior arch defect of the atlas associated to the absence of costal element of the foramen transversarium. Objective. In living patients as well as in postmortem analysis it should be difficult to distinguish between a congenital and an acquired anomaly. Any anomaly in the anatomy of atlas should be taken into consideration by clinicians, surgeons, radiologists, and anatomists in order to avoid misinterpretations and clinical complications. Summary of Background Data. Posterior arch defect has a current occurrence of approximately 4%. Posterior arch schisis is attributed to the defective or absent development of the cartilaginous preformation of the arch rather than a disturbance of the ossification. The absence of costal element of the foramen transversarium has an incidence of ranging from 2% to 10% and is attributed to a developmental defect or to variations in the course of the vertebral artery. Methods. The skeleton of a man aged 20–30 years, brought to light in the plague cemetery of 16th century Alghero (Sardinia), showed anomalies of the atlas, consisting in failure of the midline fusion of the 2 hemiarches with a small gap and an open anterior foramen trasversarium on the left side. A macroscopic, radiological, and stereomicroscopic study was carried out. Results. The study allowed to rule out a traumatic origin of the defects and to diagnose an association of 2 congenital anomalies. Conclusion. Osteoarchaeological cases provides with a valuable opportunity to examine and describe variations in the anatomy of the atlas

Atlas occipitalisation associated with other anomalies in a 16th century skeleton from Sardinia (Italy)

Archaeological excavations carried out in the plague cemetery of 16th century Alghero (Sardinia) brought to light the skeleton of a male aged 35–45 years, showing anomalies of the atlas. A macroscopic and radiological study has been carried out. The first cervical vertebra is fused with the skull base, resulting in an occipitalisation of the atlas. Absence of the costal element of the left foramen transversarium, resulting in an open anterior foramen transversarium, and posterior arch defect are also observed. The atlanto-occipital junction is a complex structure, susceptible to develop different patterns of congenital defects. These anatomical variations of atlas should be considered in modern clinical practice in order to formulate a correct diagnosis and to conceive an appropriate treatment. Osteoarchaeological cases are important as, beside to ascertain the presence of congenital defects in past populations, allow an in-depth study in dry bones, which can help modern medicine in interpreting anatomical variations. We present an association of congenital anomalies of the atlanto-occipital junction, a condition rarely documented in ancient and modern human skeletal remains

A Case of Brachymetatarsia From Medieval Sardinia (Italy)

Archaeological excavations carried out in the Medieval village of Geridu (Sardinia) uncovered several burials dating to the late 13th or the first half of 14th century. Among these individuals, the skeleton of an adult female showing a bilateral abnormal shortness of the fourth metatarsal bone was identified. Bilaterality and absence of other skeletal anomalies allow to rule out an acquired aetiology of the disease and to support a diagnosis of congenital brachymetatarsia. Such a rare deformity has a clinical incidence of 0.02% to 0.05%, with strong predominance of the female gender. To our knowledge, no other cases of brachymetatarsia have been reported in paleopathology so far

Sclerosing bone dysplasia from 16th century Sardinia (Italy): a possible case of Camurati-Engelmann disease

The skeletal remains of a male aged 45–55 years displaying several bone anomalies were unearthed from the Alghero (Sardinia) plague cemetery ‘lo Quarter’, a burial site dating back to the 1582–1583 AD outbreak. The skeleton, whose stature is about 165 cm, presents a bilateral hyperostosis with increased diameter of the diaphyses of all the long bones of the upper and lower limbs; the metaphyses appear to be involved, while the epiphyses are spared. Marked thickening of the cranial vault is also evident. Radiological study showed irregular cortical thickening and massive endoperiosteal bone apposition; sclerotic changes are observed in the diaphysis of some metacarpals. Computed tomography (CT) cross sections of the long bones displayed a thickening of the cortical portion and endoperiosteal bone apposition. The individual was affected by a sclerosing bone dysplasia, a genetic disease characterized by increased bone density. In differential diagnosis, several sclerosing bone dysplasia, such as hyperostosis corticalis generalisata, craniodiaphyseal dysplasia, craniometadiaphyseal dysplasia, pachydermoperiostosis and Camurati–Engelmann disease, as well as other disorders characterized by sclerosing manifestations, such as Erdheim–Chester disease, mehloreostosis and skeletal fluorosis, need to be considered. The anomalies observed in skeleton 2179 fit with the features of Camurati–Engelmann disease, which is the most likely candidate for final diagnosis. It is highly challenging to evaluate how such a condition may have influenced the individual’s lifestyle in terms of development, mobility and quality of life. This individual was probably symptomatic and must have experienced common clinical symptoms, such as pain in the limbs and fatigability. However, the strong development of the muscular insertions and the degenerative changes in the upper limbs suggest that the mobility problems should not have prevented him from reaching a mature age and from performing essential daily activities. The presented case is the unique paleopathological evidence of Camurati–Engelmann disease so far diagnosed

Enlarged vascular foramina and lytic lesions in vertebral bodies: a diagnostic dilemma

Among the skeletal material from the sites of Alghero, Mesumundu and Sant’Antioco di Bisarcio (Sassari, Sardinia) and dated back to the period comprises between the 13th and the late 16th century 5 subadult individuals aged between 5 and 15 years and a mature male showed peculiar osteolytic phenomena of the vertebral bodies. These lesions have the appearance of enlarged vascular foramina, affecting several vertebrae mainly of the thoracic and lumbar spine, sometimes with involvement of the sacrum; on the same vertebral body several lesions are generally visible. In the literature similar features have been attributed to brucellosis or tuberculosis. As for the Sardinian skeletal material, an imaging study on the vertebrae of the adult individual was carried out in order to evaluate the appearance of the lesions within the body. Computed Tomography evidenced internal irregular elongated cavitations, sometimes joined together; erosive rounded lesions, whose presence is not detectable externally, were also showed. The molecular analysis has so far been performed on the subadult from Sant’Antioco di Bisarcio, but at initial analysis the DNA resulted degraded. Therefore, the nature of these lesions remains unclear, as it is not sure if they should be referred to tuberculosis, brucellosis or other pathological conditions [hemolytic anemias (eg. Thalassemia), lymphomas, multiple myeloma and infection by Echinococcus]. Further molecular analyses will be carried out on the remains belonging to the other five individuals in an attempt to clarify the etiology of the above mentioned lesions

Enlarged vascular foramina and lytic lesions in vertebral bodies: a diagnostic dilemma

Among the skeletal material from the sites of Alghero, Mesumundu and Sant’Antioco di Bisarcio (Sassari, Sardinia) and dated back to the period comprises between the 13th and the late 16th century 5 subadult individuals aged between 5 and 15 years and a mature male showed peculiar osteolytic phenomena of the vertebral bodies. These lesions have the appearance of enlarged vascular foramina, affecting several vertebrae mainly of the thoracic and lumbar spine, sometimes with involvement of the sacrum; on the same vertebral body several lesions are generally visible. In the literature similar features have been attributed to brucellosis or tuberculosis. As for the Sardinian skeletal material, an imaging study on the vertebrae of the adult individual was carried out in order to evaluate the appearance of the lesions within the body. Computed Tomography evidenced internal irregular elongated cavitations, sometimes joined together; erosive rounded lesions, whose presence is not detectable externally, were also showed. The molecular analysis has so far been performed on the subadult from Sant’Antioco di Bisarcio, but at initial analysis the DNA resulted degraded. Therefore, the nature of these lesions remains unclear, as it is not sure if they should be referred to tuberculosis, brucellosis or other pathological conditions [hemolytic anemias (eg. Thalassemia), lymphomas, multiple myeloma and infection by Echinococcus]. Further molecular analyses will be carried out on the remains belonging to the other five individuals in an attempt to clarify the etiology of the above mentioned lesions

A human MMTV-like betaretrovirus linked to breast cancer has been present in humans at least since the Copper Age

The betaretrovirus Mouse Mammary Tumor Virus (MMTV) is the well characterized etiological agent of mammary tumors in mice. In contrast, the etiology of sporadic human breast cancer (BC) is unknown, but accumulating data indicate a possible viral origin also for these malignancies. The presence of MMTVenv-like sequences (MMTVels) in the human salivary glands and saliva supports the latter as possible route of interhuman dissemination. In the absence of the demonstration of a mouse-man transmission of MMTV, we considered the possibility that a cross-species transmission could have occurred in ancient times. Therefore, we investigated MMTVels in the ancient dental calculus, which originates from saliva and is an excellent material for paleovirology. The calculus was collected from 36 ancient human skulls, excluding any possible mouse contamination. MMTV-like sequences were identified in the calculus of 6 individuals dated from the Copper Age to the 17th century. The MMTV-like sequences were compared with known human endogenous betaretroviruses and with animal exogenous betaretroviruses, confirming their exogenous origin and relation to MMTV. These data reveal that a human exogenous betaretrovirus similar to MMTV has existed at least since 4,500 years ago and indirectly support the hypothesis that it could play a role in human breast cancer