Discover the most talked about and latest scientific content & concepts.

Concept: Age of Discovery


The collapse of Atlantic salmon (Salmo salar) stocks throughout North-Western Europe is generally ascribed to large-scale river regulation, water pollution and over-fishing in the 19(th) and 20(th) century. However, other causes have rarely been quantified, especially those acting before the 19(th) century. By analysing historical fishery, market and tax statistics, independently confirmed by archaeozoological records, we demonstrate that populations declined by up to 90% during the transitional period between the Early Middle Ages (c. 450-900 AD) and Early Modern Times (c. 1600 AD). These dramatic declines coincided with improvements in watermill technology and their geographical expansion across Europe. Our extrapolations suggest that historical Atlantic salmon runs must have once been very abundant indeed. The historical perspective presented here contributes to a better understanding of the primary factors that led to major declines in salmon populations. Such understanding provides an essential basis for the effective ecological rehabilitation of freshwater ecosystems.

Concepts: Middle Ages, Europe, Salmon, Modern history, Atlantic salmon, Salmo, Renaissance, Age of Discovery


Medieval European urbanization presents a line of continuity between earlier cities and modern European urban systems. Yet, many of the spatial, political and economic features of medieval European cities were particular to the Middle Ages, and subsequently changed over the Early Modern Period and Industrial Revolution. There is a long tradition of demographic studies estimating the population sizes of medieval European cities, and comparative analyses of these data have shed much light on the long-term evolution of urban systems. However, the next step-to systematically relate the population size of these cities to their spatial and socioeconomic characteristics-has seldom been taken. This raises a series of interesting questions, as both modern and ancient cities have been observed to obey area-population relationships predicted by settlement scaling theory. To address these questions, we analyze a new dataset for the settled area and population of 173 European cities from the early fourteenth century to determine the relationship between population and settled area. To interpret this data, we develop two related models that lead to differing predictions regarding the quantitative form of the population-area relationship, depending on the level of social mixing present in these cities. Our empirical estimates of model parameters show a strong densification of cities with city population size, consistent with patterns in contemporary cities. Although social life in medieval Europe was orchestrated by hierarchical institutions (e.g., guilds, church, municipal organizations), our results show no statistically significant influence of these institutions on agglomeration effects. The similarities between the empirical patterns of settlement relating area to population observed here support the hypothesis that cities throughout history share common principles of organization that self-consistently relate their socioeconomic networks to structured urban spaces.

Concepts: Scientific method, Middle Ages, Europe, Italy, Renaissance, Dark Ages, Age of Discovery, Cannon


This essay examines medical and popular attitudes to cancer in the early modern period, c.1580-1720. Cancer, it is argued, was understood as a cruel and usually incurable disease, diagnosable by a well-defined set of symptoms understood to correspond to its etymological root, karkinos (the crab). It was primarily understood as produced by an imbalance of the humours, with women being particularly vulnerable. However, such explanations proved inadequate to make sense of the condition’s malignancy, and medical writers frequently constructed cancer as quasi-sentient, zoomorphising the disease as an eating worm or wolf. In turn, these constructions materially influenced medical practice, in which practitioners swung between anxiety over ‘aggravating’ the disease and an adversarial approach which fostered the use of radical and dangerous ‘cures’ including caustics and surgery.

Concepts: Medicine, Cancer, Disease, Modern history, Age of Discovery, Early modern Europe, Early modern period


Frostbite and other cold injuries on the early polar expeditions were common. This paper explains how frostbite was described, prevented, and treated on the Antarctic expeditions of the heroic age, comparing them with modern recommendations. Nonfreezing cold injury probably also occurred but was not differentiated from frostbite, and chilblains were also described.

Concepts: Injuries, Explanation, Antarctica, Age of Discovery, Roald Amundsen, Exploration


The evolution of funeral practices from the Middle Ages through the Modern era in Europe is generally seen as a process of secularization. The study, through imaging and autopsy, of two mummies, five lead urns containing hearts, and more than six hundred skeletons of nobles and clergymen from a Renaissance convent in Brittany has led us to reject this view. In addition to exceptional embalming, we observed instances in which hearts alone had been extracted, a phenomenon that had never before been described, and brains alone as well, and instances in which each spouse’s heart had been placed on the other’s coffin. In some identified cases we were able to establish links between the religious attitudes of given individuals and either ancient Medieval practices or more modern ones generated by the Council of Trent. All of these practices, which were a function of social status, were rooted in religion. They offer no evidence of secularization whatsoever.

Concepts: Middle Ages, Europe, Religion, Italy, Renaissance, French Revolution, Burial, Age of Discovery


The abrupt onslaught of the syphilis pandemic that started in the late fifteenth century established this devastating infectious disease as one of the most feared in human history(1). Surprisingly, despite the availability of effective antibiotic treatment since the mid-twentieth century, this bacterial infection, which is caused by Treponema pallidum subsp. pallidum (TPA), has been re-emerging globally in the last few decades with an estimated 10.6 million cases in 2008 (ref. 2). Although resistance to penicillin has not yet been identified, an increasing number of strains fail to respond to the second-line antibiotic azithromycin(3). Little is known about the genetic patterns in current infections or the evolutionary origins of the disease due to the low quantities of treponemal DNA in clinical samples and difficulties in cultivating the pathogen(4). Here, we used DNA capture and whole-genome sequencing to successfully interrogate genome-wide variation from syphilis patient specimens, combined with laboratory samples of TPA and two other subspecies. Phylogenetic comparisons based on the sequenced genomes indicate that the TPA strains examined share a common ancestor after the fifteenth century, within the early modern era. Moreover, most contemporary strains are azithromycin-resistant and are members of a globally dominant cluster, named here as SS14-Ω. The cluster diversified from a common ancestor in the mid-twentieth century subsequent to the discovery of antibiotics. Its recent phylogenetic divergence and global presence point to the emergence of a pandemic strain cluster.

Concepts: Infectious disease, Bacteria, Evolution, Virus, Infection, Penicillin, Syphilis, Age of Discovery


Obesity is a progressive global phenomenon that is disparately prevalent amongst Indigenous populations. While there is a growing body of literature investigating the extrinsic contributors to obesity, there is a lack of evidence to elucidate intrinsic drivers in the context of an Indigenous population.

Concepts: Culture, Human migration, Colonialism, Indigenous peoples, Indigenous peoples of the Americas, Age of Discovery, Transformation of culture, Indigenous peoples of Africa


The term “Columbian Exchange” refers to the massive transfer of life between the Afro-Eurasian and American hemispheres that was precipitated by Columbus' voyage to the New World. The Columbian Exchange is widely appreciated by historians, social scientists and economists as a major turning point that had profound and lasting effects on the trajectory of human history and development.

Concepts: Sociology, History, Americas, World population, Christopher Columbus, Indigenous peoples of the Americas, Age of Discovery, Columbian Exchange


Unaccompanied refugee minors present with disproportionately high prevalence of emotional and psychological morbidities. However, their utilization of mental health services has been shown to be significantly poorer than the indigenous population of the country they seek asylum in. Despite this, there is limited research exploring their perspectives on the barriers they face.

Concepts: Psychology, Medicine, Demography, Population, Mental health, Psychiatry, Indigenous peoples, Age of Discovery


Polyhydroxyalkanoates are bio-based, biodegradable naturally occurring polymers produced by a wide range of organisms, from bacteria to higher mammals. The properties and biocompatibility of PHA make it possible for a wide spectrum of applications. In this context, we analyze the potential applications of PHA in biomedical science by exploring the global trend through the patent survey. The survey suggests that PHA is an attractive candidate in such a way that their applications are widely distributed in the medical industry, drug delivery system, dental material, tissue engineering, packaging material as well as other useful products.

Concepts: DNA, Bacteria, Engineering, Biomaterial, Biomedical engineering, Application software, Polyhydroxyalkanoates, Age of Discovery