Concept: Modern history
To assess the influence of stage at breast cancer diagnosis, tumour biology, and treatment on survival in contemporary times of better (neo-)adjuvant systemic therapy.
Few studies have reported associations between periodontitis and cardiovascular disease (CVD) risk in older women, which is the objective of the present investigation.
How did humans sleep before the modern era? Because the tools to measure sleep under natural conditions were developed long after the invention of the electric devices suspected of delaying and reducing sleep, we investigated sleep in three preindustrial societies [1-3]. We find that all three show similar sleep organization, suggesting that they express core human sleep patterns, most likely characteristic of pre-modern era Homo sapiens. Sleep periods, the times from onset to offset, averaged 6.9-8.5 hr, with sleep durations of 5.7-7.1 hr, amounts near the low end of those industrial societies [4-7]. There was a difference of nearly 1 hr between summer and winter sleep. Daily variation in sleep duration was strongly linked to time of onset, rather than offset. None of these groups began sleep near sunset, onset occurring, on average, 3.3 hr after sunset. Awakening was usually before sunrise. The sleep period consistently occurred during the nighttime period of falling environmental temperature, was not interrupted by extended periods of waking, and terminated, with vasoconstriction, near the nadir of daily ambient temperature. The daily cycle of temperature change, largely eliminated from modern sleep environments, may be a potent natural regulator of sleep. Light exposure was maximal in the morning and greatly decreased at noon, indicating that all three groups seek shade at midday and that light activation of the suprachiasmatic nucleus is maximal in the morning. Napping occurred on <7% of days in winter and <22% of days in summer. Mimicking aspects of the natural environment might be effective in treating certain modern sleep disorders.
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.
The modern age of metagenomics has delivered unprecedented volumes of data describing the genetic and metabolic diversity of bacterial communities, but it has failed to provide information about coincident cellular morphologies. Much like metabolic and biosynthetic capabilities, morphology comprises a critical component of bacterial fitness, molded by natural selection into the many elaborate shapes observed across the bacterial domain. In this essay, we discuss the diversity of bacterial morphology and its implications for understanding both the mechanistic and the adaptive basis of morphogenesis. We consider how best to leverage genomic data and recent experimental developments in order to advance our understanding of bacterial shape and its functional importance.
Oil pulling is a traditional folk remedy practiced in ancient India. It is believed to cure more than thirty systemic diseases when practiced regularly and as directed. Due to occurrence of side effects to modern medicines and oral hygiene products, people are increasingly attracted towards complementary and traditional practices. Oil pulling in addition to offering several oral health benefits has also beneficial effects on overall health. The present article attempts to review and discuss this ancient practice.
- Proceedings of the National Academy of Sciences of the United States of America
- Published over 4 years ago
This study reveals that the entry into World War I in 1917 indexed the decisive transition to the modern period in American political consciousness, ushering in new objects of political discourse, a more rapid pace of change of those objects, and a fundamental reframing of the main tasks of governance. We develop a strategy for identifying meaningful categories in textual corpora that span long historic durées, where terms, concepts, and language use changes. Our approach is able to account for the fluidity of discursive categories over time, and to analyze their continuity by identifying the discursive stream as the object of interest.
Menarche denotes the onset of the female reproductive capacity. The age that menarche occurs is mostly attributed to the interaction of genetics and various environmental factors. Herein, the author describes the evolution of the age at menarche from prehistoric to the present times. Data from skeletal remains suggest that in the Paleolithic female menarche occurred at an age between 7 and 13 years, early sexual maturation being a trade-off for reduced life expectancy. In the classical, as well as in the medieval years, the age at menarche was generally reported to be at about 14 years, with a range from 12-15 years. A significant retardation of the age at menarche occurred in the beginning of the modern times, soon after the industrial revolution, due to the deterioration of the living conditions, most studies reporting menarche to occur at 15-16 years. In the 20(th) century, especially in the second half of it, in the industrialized countries, the age at menarche decreased significantly, as a result of the improvement of the socioeconomic conditions, occurring between 12-13 years. In the present times, in the developed countries, this trend seems to slow down or level-off.
Perturbations in the intestinal microbiota may disrupt mechanisms involved in the development of immunologic tolerance. The present study aimed to examine the establishment of the infant microbiota and its association to the development of atopic dermatitis (AD).
The present study evaluated the effect of different drilling dimensions (undersized, regular, and oversized) in the insertion and removal torques of dental implants in a beagle dog model.