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Extreme drought conditions accompanied by rising temperatures have characterized the American Southwest during the past decade, causing widespread tree mortality in piñon-juniper woodlands. Piñon pine (Pinus edulis Engelm.) mortality is linked primarily to outbreaks of the pinyon ips (Ips confusus (Leconte)) precipitated by drought conditions. Although we searched extensively, no biotic agent was identified as responsible for death in Juniperus L. spp. in this study; hence this mortality was due to direct drought stress. Here we examine the relationship between tree abundance and patterns of mortality in three size classes (seedling/sapling, pre-reproductive, reproductive) during the recent extended drought in three regions: southwest Colorado, northern New Mexico, and northern Arizona. Piñon mortality varied from 32% to 65%, and juniper mortality from 3% to 10% across the three sites. In all sites, the greatest piñon mortality was in the larger, presumably older, trees. Using logistic regression models, we examined the influence of tree density and basal area on bark beetle infestations (piñon) and direct drought impacts (juniper). In contrast to research carried out early in the drought cycle by other researchers in Arizona, we did not find evidence for greater mortality of piñon and juniper trees in increasingly high density or basal area conditions. We conclude that the severity of this regional drought has masked densitydependent patterns visible in less severe drought conditions. With climate projections for the American Southwest suggesting increases in aridity and rising temperatures, it is critical that we expand our understanding of stress responses expected in widespread piñon-juniper woodlands.

Soil information is vital for a range of purposes; however, soils vary greatly over short distances, making accurate soil data difficult to obtain. Soil surveys were first carried out in the 1920s, and the first national soil map was produced in 1940. Several regional studies were done in the 1960s, with the national Land Type Survey completed in 2002. Subsequently, the transfer of soil data to digital format has allowed a wide range of interpretations, but many data are still not freely available as they are held by a number of different bodies. The need for soil data is rapidly expanding to a range of fields, including health, food security, hydrological modelling and climate change. Fortunately, advances have been made in fields such as digital soil mapping, which enables the soil surveyors to address the need. The South African Soil Science fraternity will have to adapt to the changing environment in order to comply with the growing demands for data. At a recent Soil Information Workshop, soil scientists from government, academia and industry met to concentrate efforts in meeting the current and future soil data needs. The priorities identified included: interdisciplinary collaboration; expansion of the current national soil database with advanced data acquisition, manipulation, interpretation and countrywide dissemination facilities; and policy and human capital development in newly emerging soil science and environmental fields. It is hoped that soil information can play a critical role in the establishment of a national Natural Agricultural Information System.

Accurate observations of cloud microphysical properties are needed for evaluating and improving the representation of cloud processes in climate models and better estimate of the Earth radiative budget. However, large differences are found in current cloud products retrieved from ground‐based remote sensing measurements using various retrieval algorithms. Understanding the differences is an important step to address uncertainties in the cloud retrievals. In this study, an in‐depth analysis of nine existing ground‐based cloud retrievals using ARM remote sensing measurements is carried out. We place emphasis on boundary layer overcast clouds and high level ice clouds, which are the focus of many current retrieval development efforts due to their radiative importance and relatively simple structure. Large systematic discrepancies in cloud microphysical properties are found in these two types of clouds among the nine cloud retrieval products, particularly for the cloud liquid and ice particle effective radius. Note that the differences among some retrieval products are even larger than the prescribed uncertainties reported by the retrieval algorithm developers. It is shown that most of these large differences have their roots in the retrieval theoretical bases, assumptions, as well as input and constraint parameters. This study suggests the need to further validate current retrieval theories and assumptions and even the development of new retrieval algorithms with more observations under different cloud regimes. Key Points Large differences exist for cloud properties retrieved from various techniques These differences are highly related to the algorithm details and inputs Cloud retrieval uncertainties need to be further understood and quantified

Model improvement efforts involve an evaluation of changes in model skill in response to changes in model physics and parameterization. When using wind measurements from various remote sensors to determine model forecast accuracy, it is important to understand the effects of measurement-uncertainty differences among the sensors resulting from differences in the methods of measurement, the vertical and temporal resolution of the measurements, and the spatial variability of these differences. Here we quantify instrument measurement variability in 80-m wind speed during WFIP2 and its impact on the calculated errors and the change in error from one model version to another. The model versions tested involved updates in model physics from HRRRv1 to HRRRv4, and reductions in grid interval from 3 km to 750 m. Model errors were found to be 2–3 m s −1 . Differences in errors as determined by various instruments at each site amounted to about 10% of this value, or 0.2–0.3 m s −1 . Changes in model skill due to physics or grid-resolution updates also differed depending on the instrument used to determine the errors; most of the instrument-to-instrument differences were ∼0.1 m s −1 , but some reached 0.3 m s −1 . All instruments at a given site mostly showed consistency in the sign of the change in error. In two examples, though, the sign changed, illustrating a consequence of differences in measurements: errors determined using one instrument may show improvement in model skill, whereas errors determined using another instrument may indicate degradation. This possibility underscores the importance of having accurate measurements to determine the model error.

An extensive literature explains recession risks using a variety of financial and business cycle variables. The problem of selecting a parsimonious set of explanatory variables, which can differ between countries and prediction horizons, is naturally suited to machine-learning methods. The current paper compares models selected by conventional machine-learning methods with a customised algorithm, ‘Doombot’, which uses ‘brute force’ to test combinations of variables and imposes restrictions so that predictions are consistent with a coherent economic narrative. The same algorithms are applied to 20 OECD countries with an emphasis on out-of-sample testing using a rolling origin, including a window for the Global Financial Crisis. Despite the imposition of additional restrictions, Doombot is found to the best performing algorithm. Further testing confirms the imposition of judgmental constraints tends to improve rather than hinder out-of-sample performance. Moreover, these constraints provide a more coherent economic narrative and so mitigate the common ‘black box’ criticism of machine-learning methods.

During spring 2016 and spring 2017, a vertically pointing, S-band Frequency Modulated Continuous Wave radar (UMass FMCW) was deployed in northern Alabama under the auspices of the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX)-Southeast. In total, ~14 weeks of data were collected, in conditions ranging from quiescent clear skies to severe thunderstorms. The principal objective of these deployments was to characterize the boundary layer evolution near the VORTEX-Southeast domain. In this paper, we describe intermediate results in service of this objective. Specifically, we describe updates to the UMass FMCW system, document its deployments for VORTEX-Southeast, and apply four automated algorithms: 1) a dealiasing algorithm to the Doppler velocities, 2) a fuzzy logic scatterer classification scheme to separate precipitation from nonprecipitation observations, 3) a brightband/melting-layer identification algorithm for stratiform precipitation, and 4) an extended Kalman filter–based convective boundary layer depth (mixing height) measurement algorithm for nonprecipitation observations. Results from the latter two applications are qualitatively verified against retrieved soundings from a collocated thermodynamic profiling system.

Fire and invasive weeds have increased the demand for native seed for restoration across the Great Basin region of the US. Cultivation of native forbs could provide less-expensive seed in necessary quantities to meet restoration needs that cannot be harvested from wildland populations alone. We evaluated 2 cultivation methods of 4 lupine species (Lupinus (Tournefort) [Fabaceae])-hairy bigleaf lupine (L. prunophilus M.E. Jones), silky lupine (L. sericeus Pursh), silvery lupine (L. argenteus Pursh), and longspur lupine (L. arbustus Douglas ex Lindl.)-to evaluate emergence, establishment, and seed production. We compared the conventional cultivation method of row crop production (control) using direct drilling to an experimental cultivation method of broadcast seeding with a mulch covering of sawdust and N-Sulate fabric (covered treatment). Under covered treatment conditions, emergence was significantly improved compared to conventional cultivation for all 4 lupine species, with P values of < 0.0001 for all 4 species. Similar results were found in 2nd-year establishment rates for silvery lupine, hairy bigleaf lupine, and silky lupine with all P values < 0.0001. Longspur lupine showed symptoms of iron deficiency chlorosis during the 1st growing season and consequently no plants established in subsequent years. Silvery lupine and silky lupine produced significantly more seed in the covered treatment than in the control with P values of < 0.0001 for both species. Our mulch treatment effectively increased emergence, establishment, and seed production in all surviving cultivars compared to the control method.

Physical characteristics include consistency, mechanical stability, oil separation, water resistance, and low-temperature flow Lubricating grease is a complex product, consisting of a lubricating fluid, performance enhancing additives, and a thickener. Multiple types of materials have been used to thicken oil to make grease, with the most common thickeners today being the soaps (salts) of long-chain fatty acids and alkaline earth metals. The key to the HPM certification is that the specification is more extensive and challenging than typical grease specifications and requires validation of performance by NLGI through independent quality certification and testing agents. [...]grease specifiers can feel confident in the quality of HPM certified greases.

Over the past 25 years, the USA has pioneered a new technological revolution, based on large numbers of new small enterprises, financed by a dynamic venture (risk) capital market. The European Union, meanwhile, has lagged behind in this sector of economic activity, and compared to the US innovative small and medium enterprises appear to find it more difficult to get started and grow. At a time when regional and local banking systems – traditionally major sources of capital for small and medium sized enterprises across Europe – are undergoing intense reorganisation and restructuring, the European Commission considers the development of a substantial risk capital market to be a key condition for closing the 'enterprise gap' with the US. While the venture capital industry is much less developed in Europe than it is in the US, nevertheless it has recently experienced a marked increase in activity. But whereas the European Commission argues that venture capital activity needs to be much more regionally clustered if it is to emulate the US experience, the OECD and some EU member states have argued for a more even regional distribution. The aim of the paper is to chart the growth and geographical anatomy of the emerging European venture capital market, and to examine its spatial development and regional implications in the context of these somewhat opposing views.

Fire and invasive weeds have increased the demand for native seed for restoration across the Great Basin region of the US. Cultivation of native forbs could provide lessexpensive seed in necessary quantities to meet restoration needs that cannot be harvested from wildland populations alone. We evaluated 2 cultivation methods of 4 lupine species (Lupinus (Tournefort) [Fabaceae])—hairy bigleaf lupine (L. prunophilus M.E. Jones), silky lupine (L. sericeus Pursh), silvery lupine (L. argenteus Pursh), and longspur lupine (L. arbustus Douglas ex Lindl.)—to evaluate emergence, establishment, and seed production. We compared the conventional cultivation method of row crop production (control) using direct drilling to an experimental cultivation method of broadcast seeding with a mulch covering of sawdust and N-Sulate fabric (covered treatment). Under covered treatment conditions, emergence was significantly improved compared to conventional cultivation for all 4 lupine species, with P values of < 0.0001 for all 4 species. Similar results were found in 2nd-year establishment rates for silvery lupine, hairy bigleaf lupine, and silky lupine with all P values < 0.0001. Longspur lupine showed symptoms of iron deficiency chlorosis during the 1st growing season and consequently no plants established in subsequent years. Silvery lupine and silky lupine produced significantly more seed in the covered treatment than in the control with P values of < 0.0001 for both species. Our mulch treatment effectively increased emergence, establishment, and seed production in all surviving cultivars compared to the control method.