Impact of Pre-Columbian Agriculture, Climate Change, and Tectonic Activity Inferred From a 5,700-Year Paleolimnological Record from Lake Nicaragua

Lake Nicaragua, the largest lake in Central America, is a promising site for paleolimnological study of past climate change, tectonic and volcanic activity, and pre-Columbian agriculture in the region. It is near the northern limit of the Intertropical Convergence Zone (ITCZ), which brings the rainy season to the tropics, so effects of decreasing precipitation due to southern migration of the ITCZ through the Holocene should be observable. Because fault zones and an active volcano lie within the lake, the long-term impact of tectonic and volcanic activity can also be examined. Finally, the fertile volcanic soils near the lake may have encouraged early agriculture. We analyzed diatoms, biogenic silica (BSi), total organic carbon (TOC), water content, volcanic glass, and magnetic susceptibility in a sediment core from Lake Nicaragua with eleven accelerator mass spectroscopy radiocarbon dates, spanning ~5,700 years. Sediment accumulation rates decreased from the bottom to the top of the core, indicating a general drying trend through the Holocene. An increase in eutrophic diatom abundance suggests that pre-Columbian agriculture impacted the lake as early as ~5,400 cal yr BP. Above a horizon of coarser grains deposited sometime between ~5,200 and 1,600 cal yr BP, planktonic diatoms increased and remained dominant to the top of the core, indicating that water depth permanently increased. Although magnetic susceptibility peaked and water content dipped at the coarse horizon, volcanic glass fragments did not increase, suggesting that the coarse horizon and subsequent increase in water depth were caused by tectonic rather than by volcanic activity. Decreased accumulation rates of BSi and TOC indicate that water became clearer when depth increased

Rabies in North America: A Model of the One Health Approach

The One Health concept merges environmental, wildlife, domestic animal, and human health into a global, interconnected context. Though recently a popular catchphrase due to the emergence and reemergence of diseases such as foot-and-mouth disease (FMD), bluetongue, bovine spongiform encephalopathy (BSE), Q Fever, Rift Valley fever, Nipah virus, West Nile virus (WNV), severe acute respiratory syndrome (SARS), highly pathogenic H5N1 avian influenza, and plague, the One Health concept is not new. The One Health approach to managing infectious diseases aims to promote and implement meaningful collaboration and communication between multiple allied disciplines working locally, nationally, and internationally to attain optimal health for people, domestic animals, wildlife, and our environment. Rabies is an ancient disease that results in more than 55,000 human deaths worldwide each year. Historic and current emphasis on interdisciplinary approaches to rabies control provides a prime example of a zoonotic disease that is being managed more effectively via the One Health approach. In North America, a few meso-carnivores and bats serve as reservoirs of rabies, perpetuating continual infection of humans, pets, and livestock. Increased emphasis on surveillance and control of rabies in wildlife is the key to local, regional, and continental elimination strategies

Development and Preliminary Tests of an Open-Path Airborne Diode Laser Absorption Instrument for Carbon Dioxide

Carbon dioxide (CO2) is well known for its importance as an atmospheric greenhouse gas, with many sources and sinks around the globe. Understanding the fluxes of carbon into and out of the atmosphere is a complex and daunting challenge. One tool applied by scientists to measure the vertical flux of CO2 near the surface uses the eddy covariance technique, most often from towers but also from aircraft flying specific patterns over the study area. In this technique, variations of constituents of interest are correlated with fluctuations in the local vertical wind velocity. Measurement requirements are stringent, particularly with regard to precision, sensitivity to small changes, and temporal sampling rate. In addition, many aircraft have limited payload capability, so instrument size, weight, and power consumption are also important considerations. We report on the development and preliminary application of an airborne sensor for the measurement of atmospheric CO2. The instrument, modeled on the successful DLH (Diode Laser Hygrometer) series of instruments, has been tested in the laboratory and on the NASA DC-8 aircraft. Performance parameters such as accuracy, precision, sensitivity, specificity, and temporal response are discussed in the context of typical atmospheric variability and suitability for flux measurement applications. On-aircraft, in-flight data have been obtained and are discussed as well. Performance of the instrument has been promising, and continued flight testing is planned during 2016

The evolutionary legacy of size-selective harvesting extends from genes to populations

Size-selective harvesting is assumed to alter life histories of exploited fish populations, thereby negatively affecting population productivity, recovery, and yield. However, demonstrating that fisheries-induced phenotypic changes in the wild are at least partly genetically determined has proved notoriously difficult. Moreover, the population-level consequences of fisheries-induced evolution are still being controversially discussed. Using an experimental approach, we found that five generations of size-selective harvesting altered the life histories and behavior, but not the metabolic rate, of wild-origin zebrafish (Danio rerio). Fish adapted to high positively size selective fishing pressure invested more in reproduction, reached a smaller adult body size, and were less explorative and bold. Phenotypic changes seemed subtle but were accompanied by genetic changes in functional loci. Thus, our results provided unambiguous evidence for rapid, harvest-induced phenotypic and evolutionary change when harvesting is intensive and size selective. According to a life-history model, the observed life-history changes elevated population growth rate in harvested conditions, but slowed population recovery under a simulated moratorium. Hence, the evolutionary legacy of size-selective harvesting includes populations that are productive under exploited conditions, but selectively disadvantaged to cope with natural selection pressures that often favor large body size.Peer reviewe

The strength of the association between heterozygosity and probability of interannual local recruitment increases with environmental harshness in blue tits

The extent of inbreeding depression and the magnitude of heterozygosity–fitness correlations (HFC) have been suggested to depend on the environmental context in which they are assayed, but little evidence is available for wild populations. We combine extensive molecular and capture–mark–recapture data from a blue tit (Cyanistes caeruleus) population to (1) analyze the relationship between heterozygosity and probability of interannual adult local recruitment and (2) test whether environmental stress imposed by physiologically suboptimal temperatures and rainfall influence the magnitude of HFC. To address these questions, we used two different arrays of microsatellite markers: 14 loci classified as neutral and 12 loci classified as putatively functional. We found significant relationships between heterozygosity and probability of interannual local recruitment that were most likely explained by variation in genomewide heterozygosity. The strength of the association between heterozygosity and probability of interannual local recruitment was positively associated with annual accumulated precipitation. Annual mean heterozygosity increased over time, which may have resulted from an overall positive selection on heterozygosity over the course of the study period. Finally, neutral and putatively functional loci showed similar trends, but the former had stronger effect sizes and seemed to better reflect genomewide heterozygosity. Overall, our results show that HFC can be context dependent, emphasizing the need to consider the role of environmental heterogeneity as a key factor when exploring the consequences of individual genetic diversity on fitness in natural populations.Peer reviewe

MTHFR polymorphisms in relation to ovarian cancer risk

Objective Folate has been hypothesized to influence carcinogenesis due to its dual role in DNA methylation, which regulates gene expression, and synthesis of purine and thymidylate, which is vital for DNA repair. Thus, we examined ovarian cancer risk in relation to two functional polymorphisms (C677T and A1298C) in the MTHFR gene. Methods We genotyped the C677T (rs1801133) and A1298C (rs1801131) MTHFR polymorphisms in 1642 cases and 2068 controls from three studies, the New England Case Control Study (NEC), Nurses’ Health Study (NHS), and Mayo Clinic Ovarian Cancer Case Control Study (MAY). Results Overall, we observed no association between either SNP and ovarian cancer risk (pooled C677T ptrend = 0.59 and A1298C ptrend = 0.58). Significant associations (C677T ptrend=0.001, A1298C ptrend=0.02) between these MTHFR SNPs and serous ovarian cancer risk were observed in the NEC study, but were not replicated in the NHS and MAY studies. Conclusions MTHFR SNPs C677T and A1298C are not associated with ovarian cancer risk. Our results highlight the need for validation of genetic findings

Cosmotopia Delineated: Rammohun Roy, William Adam and the Calcutta Unitarian Committee

This article seeks to establish the value of the concept of cosmotopia to historians of intercultural connections through presenting a case study of the Calcutta Unitarian Committee, which was active between 1821 and 1828. In tandem, it aims to enhance understanding of the origins of one particularly sustained set of intercultural connections: the interfaith network which developed between an influential group of Hindu religious and social reformers, the Brahmo Samaj, and western Unitarian Christians. The article focusses on the collaboration between the two leading figures on the Committee: Rammohun Roy, the renowned founder of the Brahmo Samaj, who is often described as the Father of Modern India; and William Adam, a Scottish Baptist missionary who was condemned as the “second fallen Adam” after his “conversion” to Unitarianism by Rammohun Roy, and who went on to cofound a utopian community in the United States. It explores the Calcutta Unitarian Committee's activities within the cosmopolitan milieu of early colonial Calcutta, and clarifies its role in the emergence of the Brahmo Samaj, in the development of a unique approach to Christian mission among Unitarians, and in laying the foundations of a transnational network whose members were in the vanguard of religious innovation, radical social reform, and debates on the “woman question” in nineteenth-century India, Britain, and the United States. In conclusion, the article draws on the case study to offer some broader reflections on the relationship between utopianism, cosmopolitanism, and colonialism

Variability of Ice Supersaturation, Nucleation, and Cirrus in TTL Vertical Layers

No abstract availabl