Concept: Great Plains
To promote optimal health and well-being, adults aged 18-60 years are recommended to sleep at least 7 hours each night (1). Sleeping <7 hours per night is associated with increased risk for obesity, diabetes, high blood pressure, coronary heart disease, stroke, frequent mental distress, and all-cause mortality (2-4). Insufficient sleep impairs cognitive performance, which can increase the likelihood of motor vehicle and other transportation accidents, industrial accidents, medical errors, and loss of work productivity that could affect the wider community (5). CDC analyzed data from the 2014 Behavioral Risk Factor Surveillance System (BRFSS) to determine the prevalence of a healthy sleep duration (≥7 hours) among 444,306 adult respondents in all 50 states and the District of Columbia. A total of 65.2% of respondents reported a healthy sleep duration; the age-adjusted prevalence of healthy sleep was lower among non-Hispanic blacks, American Indians/Alaska Natives, Native Hawaiians/Pacific Islanders, and multiracial respondents, compared with non-Hispanic whites, Hispanics, and Asians. State-based estimates of healthy sleep duration prevalence ranged from 56.1% in Hawaii to 71.6% in South Dakota. Geographic clustering of the lowest prevalence of healthy sleep duration was observed in the southeastern United States and in states along the Appalachian Mountains, and the highest prevalence was observed in the Great Plains states. More than one third of U.S. respondents reported typically sleeping <7 hours in a 24-hour period, suggesting an ongoing need for public awareness and public education about sleep health; worksite shift policies that ensure healthy sleep duration for shift workers, particularly medical professionals, emergency response personnel, and transportation industry personnel; and opportunities for health care providers to discuss the importance of healthy sleep duration with patients and address reasons for poor sleep health.
The differential warming of land and ocean leads to many continental regions in the Northern Hemisphere warming at rates higher than the global mean temperature. Adaptation and conservation efforts will, therefore, benefit from understanding regional consequences of limiting the global mean temperature increase to well below 2°C above pre-industrial levels, a limit agreed upon at the United Nations Climate Summit in Paris in December 2015. Here, we analyze climate model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to determine the timing and magnitude of regional temperature and precipitation changes across the contiguous United States (US) for global warming of 1.5 and 2°C and highlight consensus and uncertainties in model projections and their implications for making decisions. The regional warming rates differ considerably across the contiguous US, but all regions are projected to reach 2°C about 10-20 years before the global mean temperature. Although there is uncertainty in the timing of exactly when the 1.5 and 2°C thresholds will be crossed regionally, over 80% of the models project at least 2°C warming by 2050 for all regions for the high emissions scenario. This threshold-based approach also highlights regional variations in the rate of warming across the US. The fastest warming region in the contiguous US is the Northeast, which is projected to warm by 3°C when global warming reaches 2°C. The signal-to-noise ratio calculations indicate that the regional warming estimates remain outside the envelope of uncertainty throughout the twenty-first century, making them potentially useful to planners. The regional precipitation projections for global warming of 1.5°C and 2°C are uncertain, but the eastern US is projected to experience wetter winters and the Great Plains and the Northwest US are projected to experience drier summers in the future. The impact of different scenarios on regional precipitation projections is negligible throughout the twenty-first century compared to uncertainties associated with internal variability and model diversity.
Clovis, with its distinctive biface, blade and osseous technologies, is the oldest widespread archaeological complex defined in North America, dating from 11,100 to 10,700 (14)C years before present (bp) (13,000 to 12,600 calendar years bp). Nearly 50 years of archaeological research point to the Clovis complex as having developed south of the North American ice sheets from an ancestral technology. However, both the origins and the genetic legacy of the people who manufactured Clovis tools remain under debate. It is generally believed that these people ultimately derived from Asia and were directly related to contemporary Native Americans. An alternative, Solutrean, hypothesis posits that the Clovis predecessors emigrated from southwestern Europe during the Last Glacial Maximum. Here we report the genome sequence of a male infant (Anzick-1) recovered from the Anzick burial site in western Montana. The human bones date to 10,705 ± 35 (14)C years bp (approximately 12,707-12,556 calendar years bp) and were directly associated with Clovis tools. We sequenced the genome to an average depth of 14.4× and show that the gene flow from the Siberian Upper Palaeolithic Mal'ta population into Native American ancestors is also shared by the Anzick-1 individual and thus happened before 12,600 years bp. We also show that the Anzick-1 individual is more closely related to all indigenous American populations than to any other group. Our data are compatible with the hypothesis that Anzick-1 belonged to a population directly ancestral to many contemporary Native Americans. Finally, we find evidence of a deep divergence in Native American populations that predates the Anzick-1 individual.
Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110
- Proceedings of the National Academy of Sciences of the United States of America
- Published almost 5 years ago
Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation’s irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation. We project groundwater declines to assess when the study area might run out of water, and comprehensively forecast the impacts of reduced pumping on corn and cattle production. So far, 30% of the groundwater has been pumped and another 39% will be depleted over the next 50 y given existing trends. Recharge supplies 15% of current pumping and would take an average of 500-1,300 y to completely refill a depleted aquifer. Significant declines in the region’s pumping rates will occur over the next 15-20 y given current trends, yet irrigated agricultural production might increase through 2040 because of projected increases in water use efficiencies in corn production. Water use reductions of 20% today would cut agricultural production to the levels of 15-20 y ago, the time of peak agricultural production would extend to the 2070s, and production beyond 2070 would significantly exceed that projected without reduced pumping. Scenarios evaluate incremental reductions of current pumping by 20-80%, the latter rate approaching natural recharge. Findings substantiate that saving more water today would result in increased net production due to projected future increases in crop water use efficiencies. Society has an opportunity now to make changes with tremendous implications for future sustainability and livability.
Climate models project rising drought risks over the southwestern and central U.S. in the twenty-first century due to increasing greenhouse gases. The projected drier regions largely overlay the major dust sources in the United States. However, whether dust activity in U.S. will increase in the future is not clear, due to the large uncertainty in dust modeling. This study found that changes of dust activity in the U.S. in the recent decade are largely associated with the variations of precipitation, soil bareness, and surface winds speed. Using multi-model output under the Representative Concentration Pathways 8.5 scenario, we project that climate change will increase dust activity in the southern Great Plains from spring to fall in the late half of the twenty-first century - largely due to reduced precipitation, enhanced land surface bareness, and increased surface wind speed. Over the northern Great Plains, less dusty days are expected in spring due to increased precipitation and reduced bareness. Given the large negative economic and societal consequences of severe dust storms, this study complements the multi-model projection on future dust variations and may help improve risk management and resource planning.
- Proceedings of the National Academy of Sciences of the United States of America
- Published about 6 years ago
Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km(3) of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km(3), occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km(3) shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.
We describe cranial and mandibular remains of three undescribed individuals of the giant mustelid Megalictis ferox Matthew, 1907 from the latest Arikareean (Ar4), Early Miocene mammal fauna of Nebraska, and Wyoming (USA) housed at the American Museum of Natural History (New York, USA). Our phylogenetic hypothesis indicates that Ar4 specimens assigned to M. ferox constitute a monophyletic group. We assign three additional species previously referred to Paroligobunis to Megalictis: M. simplicidens, M. frazieri, and “M.” petersoni. The node containing these four species of Megalictis and Oligobunis forms the Oligobuninae. We test the hypothesis that Oligobuninae (Megalictis and Oligobunis) is a stem mustelid taxon. Our results indicate that the Oligobuninae form the sister clade to the crown extant mustelids. Based on the cranium, M. ferox is a jaguar-size mustelid and the largest terrestrial mustelid known to have existed. This new material also sheds light on a new ecomorphological interpretation of M. ferox as a bone-crushing durophage (similar to hyenas), rather than a cat-like hypercarnivore, as had been previously described. The relative large size of M. ferox, together with a stout rostrum and mandible made it one of the more powerful predators of the Early Miocene of the Great Plains of North America.
- Proceedings of the National Academy of Sciences of the United States of America
- Published almost 3 years ago
The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km(3), 9.18 km(3), and 6.81 km(3), respectively, which is comparable to the capacity of Lake Mead (35.7 km(3)), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.
Listeria monocytogenes infections are an important disease of ruminants worldwide, causing encephalitis, septicemia, and abortions. Ruminant listeriosis can also pose a food safety risk due to the potential for L. monocytogenes to enter the food supply via the farm environment. Data on the genetic diversity of L. monocytogenes from ruminant clinical cases in the United States is limited. Our goal was to assess the genetic diversity of clinical listeriosis isolates from ruminants in the Upper Great Plains states, a population not well-studied, and compare this population to isolates from ruminants in New York State. Multi-locus sequence typing (MLST) was used to classify and compare the genetic diversity of the isolates from the two regions. Loci sequences were compared to all known sequence types using the Pasteur Institute L. monocytogenes MLST database. Four novel sequence types (ST) were identified among the Upper Great Plains isolates, and four new STs were classified in the New York collection. Five STs were found to be common across the 2 geographical regions; ST 1, 7, 191, and 204. Strains of ST 7 were most frequently isolated (7/46 isolates). Strains of ST 91 were all associated with fetal infections from the Upper Great Plains. Our results demonstrate that while there are some subtypes commonly found between the two geographic regions, there are also subtypes distinct to each region.
The spread of C4 grasses in the late Neogene is one of the most important ecological transitions of the Cenozoic, but the primary driver of this global expansion is widely debated. We use the stable carbon isotopic composition (δ(13)C) of bison and mammoth tissues as a proxy for the relative abundance of C3 and C4 vegetation in their grazing habitat to determine climatic and atmospheric CO2 controls on C4 grass distributions from the Last Glacial Maximum (LGM) to the present. We predict the spatial variability of grass δ(13)C in North America using a mean of three different methods of classification and regression tree (CART) machine learning techniques and nine climatic variables. We show that growing season precipitation and temperature are the strongest predictors of all single climate variables. We apply this CART analysis to high-resolution gridded climate data and Coupled Model Intercomparison Project (CMIP5) mean paleoclimate model outputs to produce predictive isotope landscape models (“isoscapes”) for the current, mid-Holocene, and LGM average δ(13)C of grass-dominated areas across North America. From the LGM to the present, C4 grass abundances substantially increased in the Great Plains despite concurrent increases in atmospheric CO2. These results suggest that changes in growing season precipitation rather than atmospheric CO2 were critically important in the Neogene expansion of C4 grasses.