Publications by authors named "Nikolay Sirakov"

: Hemiplegic or unilateral cerebral palsy (UCP) is primarily characterized by motor impairment, mainly affecting the upper limb. Research has centered on factors influencing the varying degrees of motor deficit in UCP, using neuroscience advancements for in vivo exploration of brain structure (morphometry) and cortical reorganization (functional magnetic resonance imaging (fMRI)). This study aims to evaluate functional activation in the motor cortex in UCP and to explore how lesion characteristics and timing affect neuroplasticity and motor function.

View Article and Find Full Text PDF
Article Synopsis
  • The dispersal of Homo sapiens during MIS 3 in the Late Pleistocene, characterized by technological changes known as Initial Upper Paleolithic (IUP), is examined through excavations at Bacho Kiro Cave in Bulgaria.
  • Excavations from 2015 to 2021 uncovered over 2,000 lithic artifacts dated between 45,040 and 43,280 cal BP, alongside fauna remains and human fossils, revealing insights into the raw material use and lithic production techniques.
  • Analysis of the lithics indicates long-distance mobility for raw materials, evidence of advanced knapping techniques, and on-site tool curation, contributing to a better understanding of lithic economies across different IUP
View Article and Find Full Text PDF

(1) Although new imaging methods for examining the GIT with high diagnostic capabilities were introduced, the improvement and implementation of safe, efficient, and cost-effective approaches continue, and GIT diseases are still challenging to diagnose; (2) Methods: We aim to show the possibilities of computed tomography (CT) colonography for early diagnosis of colon diseases using a multidetector 32-channel CT scanner after appropriate preparation; (3) Results: After a colonoscopy was performed earlier, 140 patients were examined with CT colonography. Complete colonoscopy was performed in 80 patients (57.1%) out of 140 who underwent CT colonography.

View Article and Find Full Text PDF

Prostate cancer (Pca; adenocarcinoma) is one of the most common cancers in adult males and one of the leading causes of death in both men and women. The diagnosis of Pca requires substantial experience, and even then the lesions can be difficult to detect. Moreover, although the diagnostic approach for this disease has improved significantly with the advent of multiparametric magnetic resonance, that technology has certain unresolved limitations.

View Article and Find Full Text PDF

Artefacts made from stones, bones and teeth are fundamental to our understanding of human subsistence strategies, behaviour and culture in the Pleistocene. Although these resources are plentiful, it is impossible to associate artefacts to specific human individuals who can be morphologically or genetically characterized, unless they are found within burials, which are rare in this time period. Thus, our ability to discern the societal roles of Pleistocene individuals based on their biological sex or genetic ancestry is limited.

View Article and Find Full Text PDF

The expansion of Homo sapiens and our interaction with local environments, including the replacement or absorption of local populations, is a key component in understanding the evolution of our species. Of special interest are artifacts made from hard animal tissues from layers at Bacho Kiro Cave (Bulgaria) that have been attributed to the Initial Upper Paleolithic. The Initial Upper Paleolithic is characterized by Levallois-like blade technologies that can co-occur with bone tools and ornaments and likely represents the dispersal of H.

View Article and Find Full Text PDF

Bone surface modifications are crucial for understanding human subsistence and dietary behaviour, and can inform about the techniques employed in the production and use of bone tools. Permission to destructively sample such unique artefacts is not always granted. The recent development of non-destructive proteomic extraction techniques has provided some alternatives for the analysis of rare and culturally significant artefacts, including bone tools and personal ornaments.

View Article and Find Full Text PDF

The behavioral dynamics underlying the expansion of Homo sapiens into Europe remains a crucial topic in human evolution. Owing to poor bone preservation, past studies have strongly focused on the Initial Upper Paleolithic (IUP) stone tool record. Recent excavations and extensive radiocarbon dating at Bacho Kiro Cave (Bulgaria) pushed back the arrival of IUP H.

View Article and Find Full Text PDF
Article Synopsis
  • The expansion of humans across Eurasia was a significant event in human evolution, allowing our species to spread to every continent.
  • Current theories suggest these expansions only happened during warm climatic periods, but new research challenges this view.
  • Analysis of faunal remains from Bacho Kiro Cave in Bulgaria reveals that humans lived in much colder climates around 45,000 years ago, indicating that warm conditions were not necessary for early human presence in Europe.
View Article and Find Full Text PDF

Modern humans appeared in Europe by at least 45,000 years ago, but the extent of their interactions with Neanderthals, who disappeared by about 40,000 years ago, and their relationship to the broader expansion of modern humans outside Africa are poorly understood. Here we present genome-wide data from three individuals dated to between 45,930 and 42,580 years ago from Bacho Kiro Cave, Bulgaria. They are the earliest Late Pleistocene modern humans known to have been recovered in Europe so far, and were found in association with an Initial Upper Palaeolithic artefact assemblage.

View Article and Find Full Text PDF

The Middle to Upper Palaeolithic transition in Europe witnessed the replacement and partial absorption of local Neanderthal populations by Homo sapiens populations of African origin. However, this process probably varied across regions and its details remain largely unknown. In particular, the duration of chronological overlap between the two groups is much debated, as are the implications of this overlap for the nature of the biological and cultural interactions between Neanderthals and H.

View Article and Find Full Text PDF

The stratigraphy at Bacho Kiro Cave, Bulgaria, spans the Middle to Upper Palaeolithic transition, including an Initial Upper Palaeolithic (IUP) assemblage argued to represent the earliest arrival of Upper Palaeolithic Homo sapiens in Europe. We applied the latest techniques in C dating to an extensive dataset of newly excavated animal and human bones to produce a robust, high-precision radiocarbon chronology for the site. At the base of the stratigraphy, the Middle Palaeolithic (MP) occupation dates to >51,000 yr BP.

View Article and Find Full Text PDF

Excavations conducted by a Bulgarian-French team at Kozarnika Cave (Balkans, Bulgaria) during several seasons yielded a long Paleolithic archaeological sequence and led to the discovery of important faunal, lithic, and human samples. This paper aims to describe the unpublished radius shaft of an infant who died approximately before the sixth month postnatal that was recovered from layer 10b, which contained East Balkan Levallois Mousterian with bifacial leaf points. The layer was dated between 130 and 200 ka (large mammals biochronology) and between 128 ± 13 ka and 183 ± 14 ka (OSL), i.

View Article and Find Full Text PDF

Marked changes in human dispersal and development during the Middle to Upper Paleolithic transition have been attributed to massive volcanic eruption and/or severe climatic deterioration. We test this concept using records of volcanic ash layers of the Campanian Ignimbrite eruption dated to ca. 40,000 y ago (40 ka B.

View Article and Find Full Text PDF

Dermoscopy, also known as epiluminescence microscopy, is a major imaging technique used in the assessment of melanoma and other diseases of skin. In this study we propose a computer aided method and tools for fast and automated diagnosis of malignant skin lesions using non-linear classifiers. The method consists of three main stages: (1) skin lesion features extraction from images; (2) features measurement and digitization; and (3) skin lesion binary diagnosis (classification), using the extracted features.

View Article and Find Full Text PDF

Background: Dermoscopy is one of the major imaging modalities used in the diagnosis of melanoma and other pigmented skin lesions. Automated assessment tools for dermoscopy images have become an important field of research mainly because of inter- and intra-observer variations in human interpretation. One of the most important steps in dermoscopy image analysis is the detection of lesion borders, since many other features, such as asymmetry, border irregularity, and abrupt border cutoff, rely on the boundary of the lesion.

View Article and Find Full Text PDF

Objective: Our aim was to develop an insufflation system for CT colonography enabling even and quick air inflation as well as pressure control and optional emergency decompression.

Patients And Methods: A modified air insufflation system for CT colonography, consisting of an electric air pump, manometer, safety valve, and a balloon tip is presented. Thirty one patients underwent CT colonography from August to December, 2004.

View Article and Find Full Text PDF