scholarly journals Reassembling the Quarry: Quartzite Procurement and Reduction along the Potomac

1995 ◽  
Vol 15 (4) ◽  
pp. 283-319
Author(s):  
Michael D. Petraglia
Keyword(s):  
Spatial Variation ◽  
Potomac River ◽  
River Drainage ◽  
High Position ◽  
Reduction Techniques ◽  
Loudoun County ◽  
Virginia Piedmont ◽  
Reduction Strategies ◽  
Experimental Analyses ◽  
Lithic Artifacts

This article presents the results of a refitting study performed on lithic artifacts from 44LD124, a quartzite quarry in Loudoun County, Virginia. Spatial variation in quarry debris and refits demonstrated differences in intrasite reduction strategies. In one section of the site, where fire-altered quartzite debris occurred, twenty sets of refits were obtained, fifteen of which bore signs of fire-cracking or heating. In another part of the site, eleven groups of debitage were reassembled, reforming cobbles and boulders. To examine the technological and spatial consequences of various reduction techniques, quartzite percussion experiments were conducted. The technological, spatial and experimental analyses suggested that some of the reassembled groups were reduced by anvil and hammerstone percussion, in a high position from the ground, likely employing standing or kneeling stances. The findings derived from analysis of the 44LD124 materials provide information regarding quartzite procurement in the Virginia Piedmont and the Potomac River drainage.

Eels at the Edge: Science, Status, and Conservation Concerns

2009 ◽  
Keyword(s):  
Water Temperature ◽  
Stream Flow ◽  
River System ◽  
Lunar Phase ◽  
Upstream Migration ◽  
Potomac River ◽  
River Drainage ◽  
Thermal Refuge ◽  
American Eels ◽  
Atlantic Coastal

<em>Abstract.—</em>Yellow-phase American eels <em>Anguilla rostrata </em>migrate upstream extensively in Atlantic coastal river systems. However, few studies have focused on movements of large yellow American eels near dams in upper watersheds of Atlantic coastal rivers. We examined relationships between environmental variables (stream flow, water temperature, and lunar phase) and movements of radio-tagged yellow American eels (518–810 mm TL) near Millville hydroelectric dam in the lower Shenandoah River drainage of the upper watershed of the Potomac River system, West Virginia. Movements of yellow American eels differed seasonally. Water temperature and stream flow were associated with upstream migration during spring. Downstream movements during fall coincided with decreasing water temperatures and darker nights near the new moon. Eels overwintered in thermal refuge areas near tributary mouths. Localized irregular upstream and downstream movements during summer occurred near dusk and dawn and possibly reflected crepuscular foraging. Our study in the Potomac River drainage suggests the need for upstream eel passage at hydroelectric facilities when spring water temperatures exceed 15°C.

scholarly journals The Poverty in Indonesia: Concept, Approach, and the Reduction Strategies

2004 ◽  
Vol 13 (2) ◽  
Author(s):  
Muhammad Musiyam
Keyword(s):  
Economic Policy ◽  
Complex Problem ◽  
Main Stream ◽  
High Position ◽  
Side Stream ◽  
Reduction Strategies ◽  
Direct Attack ◽  
Trickle Down

Apparently, the policy of raise poverly in Indonesia start to change. In PJPT I, the strategy to raise the poverly acupied the position “Side stream of development” only. That is, the effort to raise the poverly only applied the components of macro economic policy to maintain the growth of the economy in high position. In PJPT II this effort occupy the position “main stream of development”. That is, not only does the effort depend on “trickle down effect’, but also through direct attack that concern to destitude people. The poverly phenomenon is complex problem and multidimensional, that’s not merely concern with welfare aspect (materially). Therefore, in order to the raising of poverly run effectively, we have to look the dimension of poverly as a whole. Complexity of poverly problems vary from place to place. Therefore, it is needed an accurate strategy and it must consider the characteristic of poverly and the potency that suitable to be developed. 

scholarly journals Comparison of Cycle Reduction and Model Reduction Strategies for the Design Optimization of Hybrid Powertrains on Driving Cycles

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 948
Author(s):  
Adham Kaloun ◽  
Stéphane Brisset ◽  
Maxime Ogier ◽  
Mariam Ahmed ◽  
Robin Vincent
Keyword(s):  
Model Reduction ◽  
Optimal Solution ◽  
Design Strategies ◽  
Component Level ◽  
Hybrid Powertrain ◽  
Reduction Techniques ◽  
Driving Cycles ◽  
Reduction Strategies ◽  
The Cost

Decision-making is a crucial and difficult step in the design process of complex systems such as the hybrid powertrain. Finding an optimal solution requires the system feedback. This can be, depending on the granularity of the models at the component level, highly time-consuming. This is even more true when the system’s performance is determined by its control. In fact, various possibilities can be selected to deliver the required torque to the wheels during a driving cycle. In this work, two different design strategies are proposed to minimize the fuel consumption and the cost of the hybrid powertrain. Both strategies adopt the iterative framework which allows for the separation of the powertrain design problem and its control while leading to system optimality. The first approach is based on model reduction, while the second approach relies on improved cycle reduction techniques. They are then applied to a parallel hybrid vehicle case study, leading to important cost reduction in reasonable delays and are compared using different metrics.

Proceedings of the First International Snakehead Symposium

2019 ◽  
Keyword(s):  
Chesapeake Bay ◽  
Population Size ◽  
Federal Agencies ◽  
Potomac River ◽  
Fishing Mortality ◽  
Mark Recapture ◽  
Anacostia River ◽  
River Drainage ◽  
Chesapeake Bay Watershed ◽  
Channa Argus

<em>Abstract.</em>—Northern Snakehead <em>Channa argus</em>, a species native to parts of Asia, became established in the Potomac River drainage prior to 2004. Removals by agencies appeared to do little to control abundance or limit spread into new waterways. As such, Northern Snakehead has become widespread throughout much of the Potomac River drainage in addition to many other river systems throughout the Chesapeake Bay watershed. As abundance increased within the Potomac watershed, new recreational and commercial fisheries were developed by encouragement of state and federal agencies to increase harvest. A mark–recapture program to examine growth and movement of Northern Snakehead began in 2009, as population density appeared to be increasing. In 2013, tagging methods changed to allow population size of Northern Snakehead to be estimated within selected tributaries (Little Hunting Creek (LHC) and Upper Anacostia River (UA)). From 2009–2017 we used mark–recapture angler returns and agency sampling data to view population size in context with changes in fishing mortality. The UA population linearly declined with increasing fishing mortality, while the LHC population changed very little in response to fishing mortality except for 2016 which had the lowest population estimate and highest fishing mortality. We are cautiously optimistic that exploitation may help control population growth, but recreational fishing alone is unlikely to cause significant declines in Northern Snakehead populations. Furthermore, well-established populations are likely to require high (>25%) exploitation rates to be effective.

Knowledge and Practice of Harm Reduction Strategies Among People Who Report Frequent Cannabis Use

2020 ◽  
Vol 22 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Jessica S. Kruger ◽  
Daniel Kruger ◽  
R. Lorraine Collins
Keyword(s):  
Public Health ◽  
Harm Reduction ◽  
Health Professionals ◽  
Empirical Support ◽  
Cannabis Use ◽  
Educational Strategies ◽  
Reduction Techniques ◽  
Public Health Professionals ◽  
Reduction Strategies ◽  
Knowledge And Practice

We examined knowledge and practice of harm reduction strategies among people who use cannabis attending an annual public cannabis advocacy event. We also assessed the sources from which they glean information about cannabis. Participants ( n = 472) completed a brief survey assessing cannabis use, sources for information on cannabis, and harm reduction strategies. Participants’ knowledge of cannabis was based mostly on their own experiments and experiences rather than on information from health professionals. Participants generally had low accuracy in identifying effective harm reduction techniques and low rates of utilizing effective harm reduction techniques, using them at the same rate overall as techniques without empirical support. Results from this survey will be useful to public health professionals developing and implementing harm reduction educational strategies related to cannabis use.

Valve Placement and Operation for Liquid Transmission Pipelines: A Risk Reduction Tool

2006 ◽  
Author(s):  
David A. Weir ◽  
Vienna W. Kwan ◽  
Barry F. Power
Keyword(s):  
Risk Reduction ◽  
Cost Optimization ◽  
The United States ◽  
Department Of Transportation ◽  
Regulatory Requirements ◽  
Reduction Techniques ◽  
Reduction Strategies ◽  
Valve Placement ◽  
Transmission Pipelines

The Intelligent Valve Placement (IVP) approach has been developed to incorporate risk (defined as likelihood × consequence) reduction techniques to identify optimum locations for sectionalizing (block) valves along existing or new petroleum transmission pipelines. This process aims to optimize valve placement based on risk reduction rather than current rule-of-thumbs and regulatory requirements. It may result in cost reduction and cost optimization through efficient valve placement while meeting required regulations. This approach incorporates risk through reduction of consequence, which is achieved by reducing the potential spill volumes and impact to sensitive areas in an iterative manner. With the use of consequence reduction strategies, this paper demonstrates that valve placement and operability decisions on both new or existing pipelines can be made to optimize the location of valves and provide for a safer pipeline. Although this process is highly consequence driven, there are opportunities to incorporate likelihood drivers. Equations have been developed that quantify consequence reduction and allow for determination of an optimal valve placement design. Application of this technique to pipelines in the United States is presented and the limitations of this method addressed. Although this technique is valid anywhere, this approach is in line with the requirement from the U.S. Department of Transportation to examine the placement of emergency flow restricting devices as per the High Consequence Area ruling and the requirements set forth by the Canadian Standards Association regarding remote operation of valves in Canada consistent with “extraordinary hazard” determinations.

scholarly journals Maternal Plasma Metabolic Profile Demarcates a Role for Neuroinflammation in Non-Typical Development of Children

Metabolites ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 545
Author(s):  
Rebecca J. Schmidt ◽  
Donghai Liang ◽  
Stefanie A. Busgang ◽  
Paul Curtin ◽  
Cecilia Giulivi
Keyword(s):  
Dimensionality Reduction ◽  
Principal Component ◽  
Maternal Plasma ◽  
Autism Spectrum ◽  
Plasma Metabolites ◽  
Typical Development ◽  
Reduction Techniques ◽  
Cord Plasma ◽  
Reduction Strategies ◽  
Dimensionality Reduction Techniques

Maternal and cord plasma metabolomics were used to elucidate biological pathways associated with increased diagnosis risk for autism spectrum disorders (ASD). Metabolome-wide associations were assessed in both maternal and umbilical cord plasma in relation to diagnoses of ASD and other non-typical development (Non-TD) compared to typical development (TD) in the Markers of Autism risk in Babies: Learning Early Signs (MARBLES) cohort study of children born to mothers who already have at least one child with ASD. Analyses were stratified by sample matrix type, machine mode, and annotation confidence level. Dimensionality reduction techniques were used [i.e, principal component analysis (PCA) and random subset weighted quantile sum regression (WQSRS)] to minimize the high multiple comparison burden. With WQSRS, a metabolite mixture obtained from the negative mode of maternal plasma decreased the odds of Non-TD compared to TD. These metabolites, all related to the prostaglandin pathway, underscored the relevance of neuroinflammation status. No other significant findings were observed. Dimensionality reduction strategies provided confirming evidence that a set of maternal plasma metabolites are important in distinguishing Non-TD compared to TD diagnosis. A lower risk for Non-TD was linked to anti-inflammatory elements, thereby linking neuroinflammation to detrimental brain function consistent with studies ranging from neurodevelopment to neurodegeneration.

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