The late pre-Hispanic period in the US Southwest (A.D. 1200–1450) was characterized by large-scale demographic changes, including long-distance migration and population aggregation. To reconstruct ...how these processes reshaped social networks, we compiled a comprehensive artifact database from major sites dating to this interval in the western Southwest. We combine social network analysis with geographic information systems approaches to reconstruct network dynamics over 250 y. We show how social networks were transformed across the region at previously undocumented spatial, temporal, and social scales. Using well-dated decorated ceramics, we track changes in network topology at 50-y intervals to show a dramatic shift in network density and settlement centrality from the northern to the southern Southwest after A.D. 1300. Both obsidian sourcing and ceramic data demonstrate that long-distance network relationships also shifted from north to south after migration. Surprisingly, social distance does not always correlate with spatial distance because of the presence of network relationships spanning long geographic distances. Our research shows how a large network in the southern Southwest grew and then collapsed, whereas networks became more fragmented in the northern Southwest but persisted. The study also illustrates how formal social network analysis may be applied to large-scale databases of material culture to illustrate multigenerational changes in network structure.
Perfluorobutanesulfonic acid (PFBS), a shorter chain Per- and polyfluoroalkyl substances (PFASs) cognate of perfluorooctanesulfonic acid (PFOS), has been used as replacement for the toxic surfactant ...PFOS. However, emerging evidences suggest safety concerns for PFBS and its effect on reproductive health is still understudied. Therefore, the current work aimed to investigate the effect of PFBS, in comparison to PFOS, on reproductive health using Caenorhabditis elegans as an in vivo animal model. PFOS (≥10 μM) and PFBS (≥1000 μM) significantly impaired the reproduction capacity of C. elegans, represented as reduced brood size (total egg number) and progeny number (hatched offspring number), without affecting the hatchability. Additionally, the preconception exposure of PFOS and PFBS significantly altered the embryonic nutrient loading and composition, which further led to abnormalities in growth rate, body size and locomotive activity in F1 offspring. Though the effective exposure concentration of PFBS was approximately 100 times higher than PFOS, the internal concentration of PFBS was lower than that of PFOS to produce the similar effects of PFOS. In conclusion, PFOS and PFBS significantly impaired the reproductive capacities in C. elegans and the preconception exposure of these two compounds can lead to offspring physiological dysfunctions.
•PFOS and PFBS impaired reproduction of C. elegans.•Preconception exposure of PFOS and PFBS led to offspring physiological dysfunctions.•Higher dosages are needed for PFBS to produce comparable effects of PFOS.
In 2014, Joe Shirley, Jr. and Christopher L. Clark Deschene secured the first and second place positions, respectively, in the Navajo Nation presidential elections by defeating fifteen other ...candidates. Ten days into the general election race, Deschene's campaign was thwarted when two former candidates, Hank Whitethorne and Dale E. Tsosie, filed grievances with the Navajo Nation Office of Hearings and Appeals claiming that Deschene did not meet the language fluency requirement outlined in the election code. A critical moment in the controversy was the Supreme Court of the Navajo Nation's October 9 ruling that language fluency was a reasonable regulation of the candidate's right to political liberty. Months later, Deschene was eventually removed from the ballot. This article examines the critical discourse within and around the October 9, 2014 Supreme Court ruling to illustrate the ways language, identity, and leadership are discursively and legally constituted among Diné people. This study shows how the debates about leadership, language, and identity factor into Dinéness and the shared concern with enactments of sovereignty to secure a Diné future. This article demonstrates how tribal sovereignty is closely tied to the colonial mandate of eliminating Indigenous peoples, especially in the Supreme Court's deployment of tradition to create and enforce boundaries of inclusion and exclusion.
The number of tree species on Earth Cazzolla Gatti, Roberto; Reich, Peter B; Gamarra, Javier G P ...
Proceedings of the National Academy of Sciences - PNAS,
02/2022, Volume:
119, Issue:
6
Journal Article, Web Resource
Peer reviewed
Open access
One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species ...concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.
Archaeologists have regarded social networks as both the links through which people transmitted information and goods as well as a form of social storage creating relationships that could be drawn ...upon in times of subsistence shortfalls or other deleterious environmental conditions. In this article, formal social network analytical (SNA) methods are applied to archaeological data from the late pre-Hispanic North American Southwest to look at what kinds of social networks characterized those regions that were the most enduring versus those that were depopulated over a 250-year period (A.D. 1200-1450). In that time, large areas of the Southwest were no longer used for residential purposes, some of which corresponds with welldocumented region-wide drought. Past research has demonstrated that some population levels could have been maintained in these regions, yet regional scale depopulation occurred. We look at the degree to which the network level property of embeddedness, along with population size, can help to explain why some regions were depopulated and others were not. SNA can help archaeologists examine why emigration occurred in some areas following an environmental crisis while other areas continued to be inhabited and even received migrants. Moreover, we modify SNA techniques to take full advantage of the time depth and spatial and demographic variability of our archaeological data set. The results of this study should be of interest to those who seek to understand human responses to past, present, and fliture worldwide catastrophes since it is now widely recognized that responses to major human disasters, such as hurricanes, were "likely to be shaped by pre-existing or new social networks" (as reported by Suter et al. (Research and Policy Review 28:1-10, 2009)).
Analyzing historical trajectories of social interactions at varying scales can lead to complementary interpretations of relationships among archaeological settlements. We use social network analysis ...combined with geographic information systems at three spatial scales over time in the western U.S. Southwest to show how the same social processes affected network dynamics at each scale. Theperiodwe address, A.D. 1200-1450, was characterized by migration and demographic upheaval. The tumultuous late thirteenth-century interval was followed by population coalescence and the development of widespread religious movements in the fourteenth and fifteenth centuries. In the southern Southwest these processes resulted in a highly connected network that drew in members of different settlements within and between different valleys that had previously been distinct. In the northern Southwest networks were initially highly connected followed by a more fragmented social landscape. We examine how different network textures emerged at each scale through 50-year snapshots. The results demonstrate the usefulness of applying a multiscalar approach to complex historical trajectories and the potential for social network analysis as applied to archaeological data. El análisis multi-escalar de interacciones sociales y sus trayectorias históricas pueden producir interpretaciones complementarias acerca de las relaciones entre asentamientos arqueológicos. Utilizamos el análisis de redes sociales en combinación con sistemas de información geográfica mediante tres escalas espaciales a través del tiempo en el oeste de la región del Suroeste Norteamericano para demonstrar cómo procesos sociales similares afectaron la dinámica de redes en cada escala. El período de interés, A.D. 1200-1450, se caracterizó por la migración y el desorden demográfico. El tumultuoso siglo trece fue seguido por la coalescência de poblaciones diversas y por el desarrollo de extensos movimientos religiosos en los siglos catorce y quince. En el Suroeste meridional estos procesos resultaron en una red altamente conectada que atrajo miembros de diferentes asentamientos dentro y entre diferentes valles que habían sido previamente diferenciados. En el Suroeste septentrional las redes inicialmente estuvieron muy conectadas pero fueron sucedidas por unpaisaje social fragmentario. Finalmente, examinamos cómo diferentes texturas de redes emergieron en cada escala en períodos de 50 años. Los resultados demuestran la utilidad del análisis multi-escalar para investigar trayectorias históricas complejas y el potencial del análisis de redes sociales para el estudio de datos arqueológicos.
•Use of UAS-RNAi allowed for the targeted knockdown of genes putatively involved in DDT resistance.•Cyp4g1, Cyp6g1, Cyp12d1, Lcp1, Mdr50, Mdr65, and Mrp1 were determined to be involved in DDT ...resistance.•Increased DDT sensitivity upon dsRNA injection of Mdr50, Mdr65, and Mrp1 implicated these genes in DDT efflux and resistance.
4,4'-dichlorodiphenyltrichloroethane (DDT) has been re-recommended by the World Health Organization for malaria mosquito control. Previous DDT use has resulted in resistance, and with continued use resistance will increase in terms of level and extent. Drosophila melanogaster is a model dipteran that has many available genetic tools, numerous studies done on insecticide resistance mechanisms, and is related to malaria mosquitoes allowing for extrapolation. The 91-R strain of D. melanogaster is highly resistant to DDT (>1500-fold), however, there is no mechanistic scheme that accounts for this level of resistance. Recently, reduced penetration, increased detoxification, and direct excretion have been identified as resistance mechanisms in the 91-R strain. Their interactions, however, remain unclear. Use of UAS-RNAi transgenic lines of D. melanogaster allowed for the targeted knockdown of genes putatively involved in DDT resistance and has validated the role of several cuticular proteins (Cyp4g1 and Lcp1), cytochrome P450 monooxygenases (Cyp6g1 and Cyp12d1), and ATP binding cassette transporters (Mdr50, Mdr65, and Mrp1) involved in DDT resistance. Further, increased sensitivity to DDT in the 91-R strain after intra-abdominal dsRNA injection for Mdr50, Mdr65, and Mrp1 was determined by a DDT contact bioassay, directly implicating these genes in DDT efflux and resistance.
Perfluorooctanesulfonic acid (PFOS) is a persistent synthetic surfactant widely detected in the environment. Developmental PFOS exposures are associated with low birth weight and chronic exposures ...increase risk for obesity and type 2 diabetes. As an obesogen, PFOS poses a major public health exposure risk and much remains to be understood about the critical windows of exposure and mechanisms impacted, especially during preconception. Here, we leverage evolutionarily conserved pathways and processes in the fruit fly Drosophila melanogaster (wild-type Canton-S and megalin-UAS RNAi transgenic fly lines) to investigate the window of maternal preconception exposure to PFOS on reproductive and developmental toxicity, and examine receptor (megalin)-mediated endocytosis of nutrients and PFOS into the oocyte as a potential mechanism.
Preconception exposure to 2 ng PFOS/female resulted in an internal concentration of 0.081 ng/fly over two days post exposure, no mortality and reduced megalin transcription. The number of eggs laid 1–3 days post exposure was reduced and contained 0.018 ng PFOS/egg. Following heat shock, PFOS was significantly reduced in eggs from megalin-knockdown transgenic females. Cholesterol and triglycerides were increased in eggs laid immediately following PFOS exposure by non-heat shocked transgenic females whereas decreased cholesterol and increased protein levels were found in eggs laid by heat shocked transgenic females. Preconception exposure likewise increased cholesterol in early emerging wildtype F1 adults and also resulted in progeny with a substantial developmental delay, a reduction in adult weights, and altered transcription of Drosophila insulin-like peptide genes. These findings support an interaction between PFOS and megalin that interferes with normal nutrient transport during oocyte maturation and embryogenesis, which may be associated with later in life developmental delay and reduced weight.
•Nutrients in early eggs and in F1 adults from treated flies differed from untreated flies or later eggs.•F1 flies from early eggs of treated females had developmental delay and reduced weight.•F1 flies from early eggs of treated females had altered dilp expression.•PFOS is only detected in treated females and their early laid eggs, indicating a dose-response.•Megalin knockdown decreased PFOS uptake into eggs and may act as a Trojan horse mechanism.
NASA’s Global Ecosystem Dynamics Investigation (GEDI) is collecting spaceborne full waveform lidar data with a primary science goal of producing accurate estimates of forest aboveground biomass ...density (AGBD). This paper presents the development of the models used to create GEDI’s footprint-level (~25 m) AGBD (GEDI04_A) product, including a description of the datasets used and the procedure for final model selection. The data used to fit our models are from a compilation of globally distributed spatially and temporally coincident field and airborne lidar datasets, whereby we simulated GEDI-like waveforms from airborne lidar to build a calibration database. We used this database to expand the geographic extent of past waveform lidar studies, and divided the globe into four broad strata by Plant Functional Type (PFT) and six geographic regions. GEDI’s waveform-to-biomass models take the form of parametric Ordinary Least Squares (OLS) models with simulated Relative Height (RH) metrics as predictor variables. From an exhaustive set of candidate models, we selected the best input predictor variables, and data transformations for each geographic stratum in the GEDI domain to produce a set of comprehensive predictive footprint-level models. We found that model selection frequently favored combinations of RH metrics at the 98th, 90th, 50th, and 10th height above ground-level percentiles (RH98, RH90, RH50, and RH10, respectively), but that inclusion of lower RH metrics (e.g. RH10) did not markedly improve model performance. Second, forced inclusion of RH98 in all models was important and did not degrade model performance, and the best performing models were parsimonious, typically having only 1-3 predictors. Third, stratification by geographic domain (PFT, geographic region) improved model performance in comparison to global models without stratification. Fourth, for the vast majority of strata, the best performing models were fit using square root transformation of field AGBD and/or height metrics. There was considerable variability in model performance across geographic strata, and areas with sparse training data and/or high AGBD values had the poorest performance. These models are used to produce global predictions of AGBD, but will be improved in the future as more and better training data become available.
•NASA’s GEDI collects spaceborne lidar data used for mapping aboveground biomass.•A global database of field and airborne lidar was compiled.•Models stratified by Plant Functional Type and geographic region outperform a global model.•GEDI04_A models are OLS models predicting biomass as a function of RH metrics.•Maximum forest height is an important predictor of biomass across geographic domains.
In the final centuries prior to the arrival of the Spanish, the southwest United States and northwest Mexico underwent two major sociodemographic changes: (1) many people coalesced into large ...villages, and (2) most of the villages were depopulated within two centuries. Basic epidemiological models indicate that village coalescence could have triggered epidemic diseases that caused the observed demographic decline. The models also link this decline to a global phenomenon, the Neolithic Demographic Transition. En los últimos siglos antes de la llegada de los españoles, el suroeste de los EE. UU. y el noroeste de México experimentaron dos transformaciones sociodemográficas: (1) una gran parte de la población se incorporó en aldeas grandes; y (2) la mayoría de las aldeas se despoblaron en menos de dos siglos. Modelos básicos de la epidemiología indican que la formación de aldeas grandes pudo haber provocado epidemias que causaron una disminución demográfica. Los modelos también proporcionan un enlace teórico entre los cambios regionales y un fenómeno global, la Transición Demográfica del Neolítico.
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