Trends and oscillations in the Indian summer monsoon rainfall over the last two millennia

Observations show that summer rainfall over large parts of South Asia has declined over the past five to six decades. It remains unclear, however, whether this trend is due to natural variability or increased anthropogenic aerosol loading over South Asia. Here we use stable oxygen isotopes in speleothems from northern India to reconstruct variations in Indian monsoon rainfall over the last two millennia. We find that within the long-term context of our record, the current drying trend is not outside the envelope of monsoon’s oscillatory variability, albeit at the lower edge of this variance. Furthermore, the magnitude of multi-decadal oscillatory variability in monsoon rainfall inferred from our proxy record is comparable to model estimates of anthropogenic-forced trends of mean monsoon rainfall in the 21st century under various emission scenarios. Our results suggest that anthropogenic forced changes in monsoon rainfall will remain difficult to detect against a backdrop of large natural variability

Everything in Its Right Place: Social Cooperation and Artist Compensation

The music industry\u27s crisis response to the Internet has been the primary driver of U.S. copyright policy for over a decade. The core institutional response has been to increase the scope of copyright and the use of litigation, prosecution, and technical control mechanisms for its enforcement. The assumption driving these efforts has been that without heavily-enforced copyright, artists will not be able to make a living from their art. Throughout this period artists have been experimenting with approaches that do not rely on technological or legal enforcement, but on constructing web-based business models that engage fans and rely on voluntary compliance and payment mechanisms. Anecdotal reports of such efforts have occasionally surfaced in the media. Here we present the first extensive sales-data evidence, gleaned from hundreds of thousands of online voluntary transactions, from three web-based efforts over a period of several years. This Article examines the effectiveness of these voluntary models as compared to the baseline-forcing system advocated by the industry and adopted and enforced by Congress and successive U.S. administrations over the past fifteen years. Platforms for artist-fan cooperation are complex and dynamic systems, sensitive to a variety of design factors that can either increase participation and prosocial behavior or dampen participation and enable anti-social behavior. In addition to providing substantial evidence for copyright policy, our study reports field observations of the design characteristics that support cooperation. A growing literature experimentally and theoretically explores prosocial behavior that significantly and systematically refutes the self-interest hypothesis characterizing most rational actor modeling. This literature has not yet been translated into a design approach aimed specifically at designing systems of cooperation. Building on experimental and theoretical literature in diverse fields of behavioral sciences, we synthesize a series of design levers that should improve the degree to which individuals cooperate. We then specify how these design levers might be translated into specific user interface features, describe the ways in which these design levers have been utilized in the sites under study, and present hypotheses about additional features that could improve cooperative outcomes. The Article contributes to the Internet copyright policy debates by offering empirical evidence showing that well-designed voluntary cooperation models compare favorably to more aggressive and widely criticized enforcement policies based on copyright law and the Digital Millennium Copyright Act. It provides an empirical foundation for challenging the guiding assumptions of those policies

Everything in Its Right Place: Social Cooperation and Artist Compensation

The music industry\u27s crisis response to the Internet has been the primary driver of U.S. copyright policy for over a decade. The core institutional response has been to increase the scope of copyright and the use of litigation, prosecution, and technical control mechanisms for its enforcement. The assumption driving these efforts has been that without heavily-enforced copyright, artists will not be able to make a living from their art. Throughout this period artists have been experimenting with approaches that do not rely on technological or legal enforcement, but on constructing web-based business models that engage fans and rely on voluntary compliance and payment mechanisms. Anecdotal reports of such efforts have occasionally surfaced in the media. Here we present the first extensive sales-data evidence, gleaned from hundreds of thousands of online voluntary transactions, from three web-based efforts over a period of several years. This Article examines the effectiveness of these voluntary models as compared to the baseline-forcing system advocated by the industry and adopted and enforced by Congress and successive U.S. administrations over the past fifteen years. Platforms for artist-fan cooperation are complex and dynamic systems, sensitive to a variety of design factors that can either increase participation and prosocial behavior or dampen participation and enable anti-social behavior. In addition to providing substantial evidence for copyright policy, our study reports field observations of the design characteristics that support cooperation. A growing literature experimentally and theoretically explores prosocial behavior that significantly and systematically refutes the self-interest hypothesis characterizing most rational actor modeling. This literature has not yet been translated into a design approach aimed specifically at designing systems of cooperation. Building on experimental and theoretical literature in diverse fields of behavioral sciences, we synthesize a series of design levers that should improve the degree to which individuals cooperate. We then specify how these design levers might be translated into specific user interface features, describe the ways in which these design levers have been utilized in the sites under study, and present hypotheses about additional features that could improve cooperative outcomes. The Article contributes to the Internet copyright policy debates by offering empirical evidence showing that well-designed voluntary cooperation models compare favorably to more aggressive and widely criticized enforcement policies based on copyright law and the Digital Millennium Copyright Act. It provides an empirical foundation for challenging the guiding assumptions of those policies

Synchronous Modes of Terrestrial and Marine Productivity in the North Pacific

The primary productivity of adjacent terrestrial and marine ecosystems can display synchronous responses to climate variability. Previous work has shown that this behavior emerges along the California coast where internal modes of climate variability, such as El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), alter jet stream dynamics that influence marine ecosystems through changes in upwelling and terrestrial ecosystems through changes in precipitation. This study assesses whether marine-terrestrial synchrony is a widespread phenomenon across the North Pacific by utilizing satellite-derived Solar-Induced Fluorescence (SIF) and chlorophyll-α as proxies for land and sea productivity, respectively. The results show that terrestrial and marine ecosystems are consistently synchronized across 1000's of kms of the North Pacific coastline. This synchrony emerges because both marine and terrestrial ecosystems respond to climate modes with a similar north-south dipole pattern that is mirrored across the coastal interface. The strength of synchrony is modulated by the relative states of the PDO and ENSO because the terrestrial north-south dipole is strongly controlled by the PDO while the marine pattern follows ENSO. The consequence is marine and terrestrial productivity anomalies that are opposite one another along adjacent regions of the coastline. If ENSO and the PDO have shared low-frequency variance, then synchrony would be the dominant state despite local topographic and trophic diversity along the coastlines. This result suggests that climate proxy stacks that include biologically sensitive marine and terrestrial proxies would have a selective sensitivity to modes such as PDO that drive synchrony. Lastly, the coupling of land and sea productivity may have the effect of generating amplified regional responses of the carbon budget to climate variability by simultaneously enhancing the terrestrial and marine carbon sinks

Everything in its Right Place: Social Cooperation and Artist Compensation

The music industry’s crisis response to the Internet has been the primary driver of U.S. copyright policy for over a decade. The core institutional response has been to increase the scope of copyright and the use of litigation, prosecution, and technical control mechanisms for its enforcement. The assumption driving these efforts has been that without heavily-enforced copyright, artists will not be able to make a living from their art. Throughout this period artists have been experimenting with approaches that do not rely on technological or legal enforcement, but on constructing web-based business models that engage fans and rely on voluntary compliance and payment mechanisms. Anecdotal reports of such efforts have occasionally surfaced in the media. Here we present the first extensive sales-data evidence, gleaned from hundreds of thousands of online voluntary transactions, from three web-based efforts over a period of several years. This Article examines the effectiveness of these voluntary models as compared to the baseline-forcing system advocated by the industry and adopted and enforced by Congress and successive U.S. administrations over the past fifteen years. Platforms for artist-fan cooperation are complex and dynamic systems, sensitive to a variety of design factors that can either increase participation and prosocial behavior or dampen participation and enable anti-social behavior. In addition to providing substantial evidence for copyright policy, our study reports field observations of the design characteristics that support cooperation. A growing literature experimentally and theoretically explores prosocial behavior that significantly and systematically refutes the self-interest hypothesis characterizing most rational actor modeling. This literature has not yet been translated into a design approach aimed specifically at designing systems of cooperation. Building on experimental and theoretical literature in diverse fields of behavioral sciences, we synthesize a series of design levers that should improve the degree to which individuals cooperate. We then specify how these design levers might be translated into specific user interface features, describe the ways in which these design levers have been utilized in the sites under study, and present hypotheses about additional features that could improve cooperative outcomes. The Article contributes to the Internet copyright policy debates by offering empirical evidence showing that well-designed voluntary cooperation models compare favorably to more aggressive and widely criticized enforcement policies based on copyright law and the Digital Millennium Copyright Act. It provides an empirical foundation for challenging the guiding assumptions of those policies

Initiation of the Wrangell arc: a record of tectonic changes in an arc-transform junction revealed by new geochemistry and geochronology of the ~29–18 Ma Sonya Creek volcanic field, Alaska

Master of ScienceDepartment of GeologyMatthew E. BruesekeThe Sonya Creek volcanic field (SCVF) contains the oldest in situ magmatic products in the ~29 Ma–modern Wrangell arc (WA) in south-central Alaska. The WA is located within a transition zone between Aleutian subduction to the west and dextral strike-slip tectonics along the Queen Charlotte-Fairweather and Denali-Duke River fault systems to the east. WA magmatism is due to the shallow subduction (11–16°) of the Yakutat microplate. New ⁴⁰Ar/³⁹Ar and U-Pb geochronology of bedrock and modern river sediments shows that SCVF magmatism occurred from ~29–18 Ma. Volcanic units are divided based on field mapping, physical characteristics, geochronology, and new major and trace element geochemistry. A dacite dome yields a ~29 Ma ⁴⁰Ar/³⁹Ar age and was followed by eruptions of basaltic-andesite to dacite lavas and domes (~28–23 Ma Rocker Creek lavas and domes) that record hydrous, subduction-related, calc-alkaline magmatism with an apparent adakite-like component. This was followed by a westward shift to continued subduction-related magmatism without the adakite-like component (e.g., mantle wedge melting), represented by ~23–21 Ma basaltic-andesite to dacite domes and associated diorites (“intermediate domes”). These eruptions were followed by a westward shift in volcanism to anhydrous, transitional, basaltic-andesite to rhyolite lavas of the ~23–18 Ma Sonya Creek shield volcano (Cabin Creek lavas), including a rhyolite ignimbrite unit (~19 Ma Flat Top tuff), recording the influence of local intra-arc extension. The end of SCVF activity was marked by a southward shift in volcanism back to hydrous calc-alkaline lavas at ~22–19 Ma (Young Creek rocks and Border Lavas). SCVF geochemical types are very similar to those from the <5 WA, and no alkaline lavas that characterize the ~18–10 Ma Yukon WA are present. Sr-Nd-Pb-Hf radiogenic isotope data suggest the SCVF data were generated by contamination of a depleted mantle wedge by ~0.2–4% subducted terrigenous sediment, agreeing with geologic evidence from many places along the southern Alaskan margin. Our combined dataset reveals geochemical and spatial transitions through the lifetime of the SCVF, which record changing tectonic processes during the early evolution of the WA. The earliest SCVF phases suggest the initiation of Yakutat microplate subduction. Early SCVF igneous rocks are also chemically similar to hypabyssal intrusive rocks of similar ages that crop out to the west; together these ~29–20 Ma rocks imply that WA initiation occurred over a <100 km belt, ~50–60 km inboard from the modern WA and current loci of arc magmatism that extends from Mt. Drum to Mt. Churchill

Gastric Outlet Obstruction due to Intramural Duodenal Hematoma after Endoscopic Biopsy: Possible Therapeutic Role of Endoscopic Dilation

Intramural duodenal hematoma (IDH) is an extremely rare complication after endoscopic biopsy. It typically presents with symptoms due to duodenal obstruction, which include abdominal pain and bilious vomiting. The hematoma may also expand and cause ampullary compression leading to pancreatitis and cholestasis. Computed tomography scan and abdominal ultrasound are the most common diagnostic modalities. Treatment is usually conservative, with bowel rest, nasogastric suctioning and total parenteral nutrition. Refractory cases have been described, requiring endoscopic therapy or surgical drainage. We describe a 28-year-old healthy male who presented with acute abdominal pain a few hours after a routine esophagogastrodudenoscopy with biopsies was performed. Following an otherwise uneventful endoscopy, he developed a gastric outlet obstruction and pancreatitis secondary to an IDH. The patient was managed conservatively. Resolution of his gastric outlet obstruction occurred immediately after gentle passage of the endoscope through the narrowed duodenal lumen

Dew frequency across the US from a network of in situ radiometers

Dew formation is a ubiquitous process, but its importance to energy budgets or ecosystem health is difficult to constrain. This uncertainty arises largely because of a lack of continuous quantitative measurements on dew across ecosystems with varying climate states and surface characteristics. This study analyzes dew frequency from the National Ecological Observatory Network (NEON), which includes 11 grasslands and 19 forest sites from 2015 to 2017. Dew formation is determined at 30&thinsp;min intervals using in situ radiometric surface temperatures from multiple heights within the canopy along with meteorological measurements. Dew frequency in the grasslands ranges from 15 % to 95 % of the nights with a strong linear dependency on the nighttime relative humidity (RH), while dew frequency in the forests is less frequent and more homogeneous (25±14 %, 1 standard deviation – SD). Dew mostly forms at the top of the canopy for the grasslands due to more effective radiative cooling and within the canopy for the forests because of higher within the canopy RH. The high temporal resolution of our data showed that dew duration reaches maximum values (∼6–15&thinsp;h) for RH∼96 % and for a wind speed of ∼0.5ms-1, independent of the ecosystem type. While dew duration can be inferred from the observations, dew yield needs to be estimated based on the Monin–Obukhov similarity theory. We find yields of 0.14±0.12mmnight-1 (1 SD from nine grasslands) similar to previous studies, and dew yield and duration are related by a quadratic relationship. The latent heat flux released by dew formation is estimated to be non-negligible (∼10Wm-2), associated with a Bowen ratio of ∼3. The radiometers used here provide canopy-averaged surface temperatures, which may underestimate dew frequency because of localized cold points in the canopy that fall below the dew point. A statistical model is used to test this effect and shows that dew frequency can increase by an additional ∼5 % for both ecosystems by considering a reasonable distribution around the mean canopy temperature. The mean dew duration is almost unaffected by this sensitivity analysis. In situ radiometric surface temperatures provide a continuous, non-invasive and robust tool for studying dew frequency and duration on a fine temporal scale.</p

Assessing a New Clue to How Much Carbon Plants Take Up

Current climate models disagree on how much carbon dioxide land ecosystems take up for photosynthesis. Tracking the stronger carbonyl sulfide signal could help

Revisiting the contribution of transpiration to global terrestrial evapotranspiration

Even though knowing the contributions of transpiration (T), soil and open water evaporation (E), and interception (I) to terrestrial evapotranspiration (ET=T+E+I) is crucial for understanding the hydrological cycle and its connection to ecological processes, the fraction of T is unattainable by traditional measurement techniques over large scales. Previously reported global mean T/(E+T+I) from multiple independent sources, including satellite-based estimations, reanalysis, land surface models, and isotopic measurements, varies substantially from 24% to 90%. Here we develop a new ET partitioning algorithm, which combines global evapotranspiration estimates and relationships between leaf area index (LAI) and T/(E+T) for different vegetation types, to upscale a wide range of published site-scale measurements. We show that transpiration accounts for about 57.2% (with standard deviation6.8%) of global terrestrial ET. Our approach bridges the scale gap between site measurements and global model simulations,and can be simply implemented into current global climate models to improve biological CO2 flux simulations