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2010

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Orostiff: Face-Referenced Measurement Of Perioral Stiffness In Health And Disease, Shin-Ying Chu, Steven M. Barlow, Douglas Kieweg, Jaehoon Lee Jan 2010

Orostiff: Face-Referenced Measurement Of Perioral Stiffness In Health And Disease, Shin-Ying Chu, Steven M. Barlow, Douglas Kieweg, Jaehoon Lee

Department of Special Education and Communication Disorders: Faculty Publications

A new device and automated measurement technology known as OroSTIFF is described to characterize non-participatory perioral stiffness in healthy adults for eventual application to patients with orofacial movement disorders associated with neuromotor disease, traumatic injury, or congenital clefts of the upper lip. Previous studies of perioral biomechanics required head stabilization for extended periods of time during measurement which precluded sampling patients with involuntary body/head movements (dyskinesias), or pediatric subjects. The OroSTIFF device is face-referenced and avoids the complications associated with head-restraint. Supporting data of non-participatory perioral tissue stiffness using OroSTIFF are included from 10 male and 10 female healthy subjects. …

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Abandoned Mine Drainage In The Swatara Creek Basin, Southern Anthracite Coalfield, Pennsylvania, Usa: 1. Stream Water Quality Trends Coinciding With The Return Of Fish, Charles A. Cravotta Iii, Robin A. Brightbill, Michael J. Langland Jan 2010

Abandoned Mine Drainage In The Swatara Creek Basin, Southern Anthracite Coalfield, Pennsylvania, Usa: 1. Stream Water Quality Trends Coinciding With The Return Of Fish, Charles A. Cravotta Iii, Robin A. Brightbill, Michael J. Langland

United States Geological Survey: Staff Publications

Acidic mine drainage (AMD) from legacy anthracite mines has contaminated Swatara Creek in eastern Pennsylvania. Intermittently collected base-flow data for 1959–1986 indicate that fish were absent immediately downstream from the mined area where pH ranged from 3.5 to 7.2 and concentrations of sulfate, dissolved iron, and dissolved aluminum were as high as 250, 2.0, and 4.7 mg/L, respectively. However, in the 1990s, fish returned to upper Swatara Creek, coinciding with the implementation of AMD treatment (limestone drains, limestone diversion wells, limestone sand, constructed wetlands) in the watershed. During 1996–2006, as many as 25 species of fish were identified in the …

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Prey-Mediated Avoidance Of An Intraguild Predator By Its Intraguild Prey, Ryan R. Wilson, Terry L. Blankenship, Mevin B. Hooten, John Shivik Jan 2010

Prey-Mediated Avoidance Of An Intraguild Predator By Its Intraguild Prey, Ryan R. Wilson, Terry L. Blankenship, Mevin B. Hooten, John Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Intraguild (IG) predation is an important factor influencing community structure, yet factors allowing coexistence of IG predator and IG prey are not well understood. The existence of spatial refuges for IG prey has recently been noted for their importance in allowing coexistence. However, reduction in basal prey availability might lead IG prey to leave spatial refuges for greater access to prey, leading to increased IG predation and fewer opportunities for coexistence. We determined how the availability of prey affected space-use patterns of bobcats (Lynx rufus, IG prey) in relation to coyote space-use patterns (Canis latrans, IG …

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Mineralogical And Chemical Characteristics Of Some Natural Jarosites, George A. Desborough, Kathleen S. Smith, Heather A. Lowers, Gregg A. Swayze, Jane M. Hammarstrom, Sharon F. Diehl, Reinhard W. Leinz, Rhonda L. Driscoll Jan 2010

Mineralogical And Chemical Characteristics Of Some Natural Jarosites, George A. Desborough, Kathleen S. Smith, Heather A. Lowers, Gregg A. Swayze, Jane M. Hammarstrom, Sharon F. Diehl, Reinhard W. Leinz, Rhonda L. Driscoll

United States Geological Survey: Staff Publications

This paper presents a detailed study of the mineralogical, microscopic, thermal, and spectral characteristics of jarosite and natrojarosite minerals. Systematic mineralogic and chemical examination of a suite of 32 natural stoichiometric jarosite and natrojarosite samples from diverse supergene and hydrothermal environments indicates that there is only limited solid solution between Na and K at low temperatures, which suggests the presence of a solvus in the jarosite-natrojarosite system at temperatures below about 140 °C. The samples examined in this study consist of either end members or coexisting end-member pairs of jarosite and natrojarosite. Quantitative electron-probe microanalysis data for several natural hydrothermal …

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Heat Flow And Hydrologic Characteristics At The And-1b Borehole, Andrill Mcmurdo Ice Shelf Project, Antarctica, Roger H. Morin, Trevor Williams, Stuart A. Henrys, Diana Magens, Frank Niessen, Dhiresh Hansaraj Jan 2010

Heat Flow And Hydrologic Characteristics At The And-1b Borehole, Andrill Mcmurdo Ice Shelf Project, Antarctica, Roger H. Morin, Trevor Williams, Stuart A. Henrys, Diana Magens, Frank Niessen, Dhiresh Hansaraj

United States Geological Survey: Staff Publications

The Antarctic Drilling Program (ANDRILL) successfully drilled and cored a borehole, AND-1B, beneath the McMurdo Ice Shelf and into a flexural moat basin that surrounds Ross Island. Total drilling depth reached 1285 m below sea floor (mbsf) with 98 percent core recovery for the detailed study of glacier dynamics. With the goal of obtaining complementary information regarding heat fl ow and permeability, which is vital to understanding the nature of marine hydrogeologic systems, a succession of three temperature logs was recorded over a five day span to monitor the gradual thermal recovery toward equilibrium conditions. These data were extrapolated to …

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The Influence Of Topology On Hydraulic Conductivity In A Sand-And-Gravel Aquifer, Roger H. Morin, Denis R. Leblanc, Brent M. Troutman Jan 2010

The Influence Of Topology On Hydraulic Conductivity In A Sand-And-Gravel Aquifer, Roger H. Morin, Denis R. Leblanc, Brent M. Troutman

United States Geological Survey: Staff Publications

A field experiment consisting of geophysical logging and tracer testing was conducted in a single well that penetrated a sand-and-gravel aquifer at the U.S. Geological Survey Toxic Substances Hydrology research site on Cape Cod, Massachusetts. Geophysical logs and flowmeter/pumping measurements were obtained to estimate vertical profiles of porosity ϕ, hydraulic conductivity K, temperature, and bulk electrical conductivity under background, freshwater conditions. Saline-tracer fluid was then injected into the well for 2 h and its radial migration into the surrounding deposits was monitored by recording an electromagnetic-induction log every 10 min. The field data are analyzed and interpreted primarily …

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Scale‐Invariant Stress Orientations And Seismicity Rates Near The San Andreas Fault, Amy Day-Lewis, Mark D. Zoback, Stephen Hickman Jan 2010

Scale‐Invariant Stress Orientations And Seismicity Rates Near The San Andreas Fault, Amy Day-Lewis, Mark D. Zoback, Stephen Hickman

United States Geological Survey: Staff Publications

We analyzed measurements of the direction of maximum horizontal compressive stress as a function of depth in two scientific research wells near the San Andreas Fault in central and southern California. We found that the stress orientations exhibit scale‐invariant fluctuations over intervals from tens of cm to several km. Similarity between the scaling of the stress orientation fluctuations and the scaling of earthquake frequency with fault size suggests that these fluctuations are controlled by stress perturbations caused by slip on faults of various sizes in the critically‐stressed crust adjacent to the fault. The apparent difference in stress scaling parameters between …

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In-Situ Stress And Fracture Characterization For Planning Of An Egs Stimulation In The Desert Peak Geothermal Field, Nevada, Stephen H. Hickman, Nicholas C. Davatzes Jan 2010

In-Situ Stress And Fracture Characterization For Planning Of An Egs Stimulation In The Desert Peak Geothermal Field, Nevada, Stephen H. Hickman, Nicholas C. Davatzes

United States Geological Survey: Staff Publications

An integrated study of natural fracture geometry, fluid flow and stress was conducted in Desert Peak well 27-15 in preparation for development of an Enhanced Geothermal System (EGS) through hydraulic stimulation. This stimulation will be carried out at depths of ~3000 to 3500 ft in units comprised of silicified rhyolite tuffs and metamorphosed mudstones at ambient temperatures of ~180 to 195° C. Our previous analyses of borehole image logs from this well showed that the current minimum horizontal principal stress, Shmin, is oriented 114 ± 17º and that numerous fractures in the planned stimulation interval are optimally oriented for normal …

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The Ties That Bind: Soil Surveyor William Edgar Tharp And Oceanographic Cartographer Marie Tharp, Edward R. Landa Jan 2010

The Ties That Bind: Soil Surveyor William Edgar Tharp And Oceanographic Cartographer Marie Tharp, Edward R. Landa

United States Geological Survey: Staff Publications

The link between soil science and geology is personified in the American father and daughter: soil surveyor William Edgar Tharp (1870–1959) and oceanographic cartographer Marie Tharp (1920–2006). From 1904 to 1935, W.E. Tharp mapped soils in 14 states for the US Department of Agriculture, and campaigned during the late 1920s–early 1930s to raise awareness of the high rates of soil erosion from croplands. The lifestyle of the federal soil surveyor in the United States during the early 20th century involved frequent household moves, and it played a formative role in Marie Tharp’s childhood. Her path to a career in geology …

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Microbial Production Of Isotopically Light Iron(Ii) In A Modern Chemically Precipitated Sediment And Implications For Isotopic Variations In Ancient Rocks, G. E. Tangalos, B. L. Beard, C. M. Johnson, Charles N. Alpers, E. S. Shelobolina, H. Xu, H. Konishi, E. E. Roden Jan 2010

Microbial Production Of Isotopically Light Iron(Ii) In A Modern Chemically Precipitated Sediment And Implications For Isotopic Variations In Ancient Rocks, G. E. Tangalos, B. L. Beard, C. M. Johnson, Charles N. Alpers, E. S. Shelobolina, H. Xu, H. Konishi, E. E. Roden

United States Geological Survey: Staff Publications

The inventories and Fe isotope composition of aqueous Fe(II) and solid-phase Fe compounds were quantified in neutral-pH, chemically precipitated sediments downstream of the Iron Mountain acid mine drainage site in northern California, USA. The sediments contain high concentrations of amorphous Fe(III) oxyhydroxides [Fe(III)am] that allow dissimilatory iron reduction (DIR) to predominate over Fe–S interactions in Fe redox transformation, as indicated by the very low abundance of Cr(II)-extractable reduced inorganic sulfur compared with dilute HCl-extractable Fe. δ56Fe values for bulk HCl- and HF-extractable Fe were ≈ 0. These near-zero bulk δ56Fe values, together with the …

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Hydrogeophysical Methods For Analyzing Aquifer Storage And Recovery Systems, Burke J. Minsley, Jonathan Ajo-Franklin, Amitabha Mukhopadhyay, Frank Dale Morgan Jan 2010

Hydrogeophysical Methods For Analyzing Aquifer Storage And Recovery Systems, Burke J. Minsley, Jonathan Ajo-Franklin, Amitabha Mukhopadhyay, Frank Dale Morgan

United States Geological Survey: Staff Publications

Hydrogeophysical methods are presented that support the siting and monitoring of aquifer storage and recovery (ASR) systems. These methods are presented as numerical simulations in the context of a proposed ASR experiment in Kuwait, although the techniques are applicable to numerous ASR projects. Bulk geophysical properties are calculated directly from ASR flow and solute transport simulations using standard petrophysical relationships and are used to simulate the dynamic geophysical response to ASR. This strategy provides a quantitative framework for determining site-specific geophysical methods and data acquisition geometries that can provide the most useful information about the ASR implementation. An axisymmetric, coupled …

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Evidence For Recent Population Bottlenecks In Northern Spotted Owls (Strix Occidentalis Caurina), W. Chris Funk, Eric D. Forsman, Matthew Johnson, Thomas D. Mullins, Susan M. Haig Jan 2010

Evidence For Recent Population Bottlenecks In Northern Spotted Owls (Strix Occidentalis Caurina), W. Chris Funk, Eric D. Forsman, Matthew Johnson, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the US Endangered Species Act. Despite protection of its remaining forest habitat, recent field studies show continued declines of northern spotted owls. One potential threat to northern spotted owls which has not yet been shown is loss of genetic variation from population bottlenecks. Bottlenecks can increase the probability of mating among related individuals, potentially causing inbreeding depression, and can decrease adaptive potential. Here we report evidence for recent bottlenecks in northern spotted owls using a large genetic dataset (352 individuals …

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Subspecies Status And Population Genetic Structure In Piping Plover (Charadrius Melodus), Mark P. Miller, Susan M. Haig, Cheri L. Gratto-Trevor, Thomas D. Mullins Jan 2010

Subspecies Status And Population Genetic Structure In Piping Plover (Charadrius Melodus), Mark P. Miller, Susan M. Haig, Cheri L. Gratto-Trevor, Thomas D. Mullins

United States Geological Survey: Staff Publications

Piping Plover (Charadrius melodus) is a migratory shorebird that is listed as endangered in Canada and the U.S. Great Lakes and as threatened throughout the rest of its breeding and winter range. We undertook a comprehensive molecular-genetic investigation to (1) address subspecific taxonomy, (2) characterize population genetic structure, and (3) infer past bottlenecks and demographic processes in this species. Analyses included individuals from 23 U.S. states and Canadian provinces and were based on mitochondrial DNA sequences (580 base pairs, n = 245) and 8 nuclear microsatellite loci (n = 229). Our findings provide support for separate Atlantic and …

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The Cleaning Of Burned And Contaminated Archaeological Maize Prior To 87sr/86sr Analysis, L.V. Benson, H. E. Taylor, T. I. Plowman, D. A. Roth, R. C. Antweiler Jan 2010

The Cleaning Of Burned And Contaminated Archaeological Maize Prior To 87sr/86sr Analysis, L.V. Benson, H. E. Taylor, T. I. Plowman, D. A. Roth, R. C. Antweiler

United States Geological Survey: Staff Publications

Accurate trace-metal and strontium-isotope analyses of archaeological corn cobs require that metal contaminants be removed prior to chemical analysis. Archaeological cobs are often coated with construction debris, dust, or soilwhich contains mineral particles. In addition, most archaeological cobs are partially or completely burned and the burned parts incorporate mineral debris in their hardened residual structures. Unburned cobs are weak ion exchangers and most metals within a cob are not firmly bound to cob organic matter; therefore, immersing cobs in acids and rinsing them in deionized water to remove mineral contaminants may result in the undesirable loss of metals, including strontium, …

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A Graphical Method To Evaluate Spectral Preprocessing In Multivariate Regression Calibrations: Example With Savitzky–Golay Filters And Partial Least Squares Regression, Stephen R. Delwiche, James B. Reeves Iii Jan 2010

A Graphical Method To Evaluate Spectral Preprocessing In Multivariate Regression Calibrations: Example With Savitzky–Golay Filters And Partial Least Squares Regression, Stephen R. Delwiche, James B. Reeves Iii

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In multivariate regression analysis of spectroscopy data, spectral preprocessing is often performed to reduce unwanted background information (offsets, sloped baselines) or accentuate absorption features in intrinsically overlapping bands. These procedures, also known as pretreatments, are commonly smoothing operations or derivatives. While such operations are often useful in reducing the number of latent variables of the actual decomposition and lowering residual error, they also run the risk of misleading the practitioner into accepting calibration equations that are poorly adapted to samples outside of the calibration. The current study developed a graphical method to examine this effect on partial least squares (PLS) …

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Predicting Successful Aging In A Population-Based Sample Of Georgia Centenarians, Jonathan Arnold, Jianliang Dai, Lusine Nahapetyan, Ankit Arte, Mary Ann Johnson, Dorothy Hausman, Willard L. Rodgers, Robert Hensley, Peter Martin, Maurice Macdonald, Adam Davey, Ilene C. Siegler, S. Michal Jazwinski, Leonard W. Poon Jan 2010

Predicting Successful Aging In A Population-Based Sample Of Georgia Centenarians, Jonathan Arnold, Jianliang Dai, Lusine Nahapetyan, Ankit Arte, Mary Ann Johnson, Dorothy Hausman, Willard L. Rodgers, Robert Hensley, Peter Martin, Maurice Macdonald, Adam Davey, Ilene C. Siegler, S. Michal Jazwinski, Leonard W. Poon

Department of Nutrition and Health Sciences: Faculty Publications

Used a population-based sample (Georgia Centenarian Study, GCS), to determine proportions of centenarians reaching 100 years as (1) survivors (43%) of chronic diseases first experienced between 0–80 years of age, (2) delayers (36%) with chronic diseases first experienced between 80–98 years of age, or (3) escapers (17%) with chronic diseases only at 98 years of age or older. Diseases fall into two morbidity profiles of 11 chronic diseases; one including cardiovascular disease, cancer, anemia, and osteoporosis, and another including dementia. Centenarians at risk for cancer in their lifetime tended to be escapers (73%), while those at risk for cardiovascular disease …

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Tree-Ring Dates And Demographic Change In The Southern Colorado Plateau And Rio Grande Regions, Michael S. Berry, Larry Benson Jan 2010

Tree-Ring Dates And Demographic Change In The Southern Colorado Plateau And Rio Grande Regions, Michael S. Berry, Larry Benson

United States Geological Survey: Staff Publications

In this chapter, tree-ring dates from the southern Colorado Plateau, Mogollon Highlands, and Rio Grande areas (fig. 3-1) (hereafter referred to as the study area) are used to estimate regional-scale timber-harvesting and construction activities between AD 600 and 1600 (the Basketmaker III through Pueblo IV periods). Within that time span, we focus our attention particularly on the AD 1045-1300 period, a time when anomalously wet periods alternated with megadroughts (fig. 3.2). Treering- date distributions (histograms) for eight archaeological subregions within the study area have been created using a database of more than twenty-four thousand tree-ring dates from archaeological sites. These …

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Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta J. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato Jan 2010

Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta J. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato

United States Geological Survey: Staff Publications

The creation and use of a globally available database of DNA sequences from a standardized gene region has been proposed as a tool for species identification, assessing genetic diversity and monitoring the legal and illegal trade in wildlife species. Here, we contribute to the Barcode of Life Data System and test whether a short region of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene would reliably distinguish among a suite of commonly hunted African and South American mammal and reptile species. We used universal primers to generate reference barcode sequences of 645 bp for 23 species from five vertebrate …

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Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta L. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato Jan 2010

Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta L. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato

United States Geological Survey: Staff Publications

The creation and use of a globally available database of DNA sequences from a standardized gene region has been proposed as a tool for species identification, assessing genetic diversity and monitoring the legal and illegal trade in wildlife species. Here, we contribute to the Barcode of Life Data System and test whether a short region of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene would reliably distinguish among a suite of commonly hunted African and South American mammal and reptile species. We used universal primers to generate reference barcode sequences of 645 bp for 23 species from five vertebrate …

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The Role Of African Dust In The Formation Of Quaternary Soils On Mallorca, Spain And Implications For The Genesis Of Red Mediterranean Soils, Daniel R. Muhs, James Budahn, Anna Avila, Gary Skipp, Joshua Freeman, Deanna Patterson Jan 2010

The Role Of African Dust In The Formation Of Quaternary Soils On Mallorca, Spain And Implications For The Genesis Of Red Mediterranean Soils, Daniel R. Muhs, James Budahn, Anna Avila, Gary Skipp, Joshua Freeman, Deanna Patterson

United States Geological Survey: Staff Publications

African dust additions explain the origin of terra rossa soils that are common on the carbonate-platform island of Mallorca, Spain. Mineralogical and geochemical analyses indicate that Quaternary carbonate eolianites on Mallorca have a very high purity, usually composed of more than 90% carbonate minerals (calcite, dolomite, and aragonite). In contrast, terra rossa soils developed on these eolianites have lower carbonate contents and contain higher concentrations of quartz and other silicates. Analyses of immobile trace elements indicate that the non-carbonate fractions of the eolianites have distinctive Zr/Hf, La/Yb, Cr/Sc and Th/Ta values that differ from the superjacent terra rossa soils. These …

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Assessing The Potential For Luminescence Dating Of Basalts, S. Tsukamoto, G. A.T. Duller, A. G. Wintle, Daniel R. Muhs Jan 2010

Assessing The Potential For Luminescence Dating Of Basalts, S. Tsukamoto, G. A.T. Duller, A. G. Wintle, Daniel R. Muhs

United States Geological Survey: Staff Publications

The possibility of dating basalt using luminescence was tested on four samples with independent age control from Cima volcanic !eld, California, with the ultimate aim of assessing whether the technique could be used to date sediments on the surface of Mars. Previous analysis of these samples had demonstrated that the infrared stimulated luminescence (IRSL) signal is most suitable for dating as it showed the lowest fading rate among various luminescence signals. In this study, changes in equivalent dose as a function of preheat are described. The ages for the two youngest Cima samples agree with the independent ages based on …

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Monetary Policies In A Small Open Economy Model With Labor Mobility And Remittances, Diana Rose Del Rosario Jan 2010

Monetary Policies In A Small Open Economy Model With Labor Mobility And Remittances, Diana Rose Del Rosario

Dissertations and Theses Collection (Open Access)

This paper presents a model of a small open economy that allows for international labor mobility, thereby endogenizing migrant transfers or remittances. The resulting model is calibrated to the Philippine economy, of which labor migration and remittance inflows are key forces that drive the economy’s growth. The model’s impulse response functions illustrate that the presence of these features generates a different set of dynamics from the standard small open economy model (without labor mobility). Depending on the source of the shock, labor mobility and remittances can either exacerbate or cushion the impact of the shock on the economy. A temporary …

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Parents, Teachers And The "Community Of Practice", Jackie Laluvein Jan 2010

Parents, Teachers And The "Community Of Practice", Jackie Laluvein

The Qualitative Report

Raffo and Gunter (20087) argue that there is insufficient research which has "systematically examined, categorised and synthesised the types of leadership in schools that might assist social inclusion" (p. 397). In this paper I argue that Wenger's concept of a "community of practice", when applied to the parent-teacher relationship, provides a framework for future qualitative research agendas which explore "how social inclusion/exclusion can be defined in terms of access, recognition and meaningful participation issues ('equity')" (Raffo and Gunter, p.397).

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Mining Antagonistic Communities From Social Networks, Kuan Zhang Jan 2010

Mining Antagonistic Communities From Social Networks, Kuan Zhang

Dissertations and Theses Collection (Open Access)

In this thesis, we examine the problem of mining antagonistic communities from social networks. In social networks, people with opposite opinions normally behave differently and form sub-communities each of which containing people sharing some common behaviors. In one scenario, people with opposite opinions show differences in their views on a set of items. Another scenario is people explicitly expressing whom they agree with, like or trust as well as whom they disagree with, dislike or distrust. We defined the indirect and direct antagonistic groups based on the two scenarios. We have developed algorithms to mine the two types of antagonistic …

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Security And Performance Analysis For Rfid Protocols, Bing Liang Jan 2010

Security And Performance Analysis For Rfid Protocols, Bing Liang

Dissertations and Theses Collection (Open Access)

Radio Frequency Identification (RFID) is an advanced object identification technology that has already been applied in various industries. However, the insecure nature of the communication channel between readers and tags makes RFID systems vulnerable to various kinds of attacks. In recent years, many new methods have been proposed to improve the security of RFID systems, such as disabling tags, agent management and establishing cryptographic protocols. Among them, we focus on the last approach, which is more economic and convenient in certain cases. The first part of our work is to categorize typical existing RFID protocols according to their security levels. …

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Dynamic Quay Crane Allocation, Yan Zhang Jan 2010

Dynamic Quay Crane Allocation, Yan Zhang

Dissertations and Theses Collection (Open Access)

We introduce simple rules for quay cranes to handle containers along a berth where vessels arrive continuously in time. We first analyze a model where workload is continuous. Our analysis shows that if the system is configured properly, it will always converge to a state with the maximum possible throughput regardless of external disruptions or changes in workload. Numerical simulations based on a discrete workload model suggest that, by following the same rules, the system can still converge to state with throughput that is very close to its upper bound.

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Pricing And Inventory Control In Dual-Channel Network With One Manufacturer And Retailer, Zhicong Pan Jan 2010

Pricing And Inventory Control In Dual-Channel Network With One Manufacturer And Retailer, Zhicong Pan

Dissertations and Theses Collection (Open Access)

The study on multi-channel problems has been one of the most active research fields in recent years. In this paper, we consider a dual-channel network problem with one manufacture and one retailer. The manufacturer, acting as the Stackelberg leader, sells a single type of product through a traditional channel to the retailer and/or through a direct channel to customers. The retailer, acting as the follower, operates a Newsvendor model, ordering from the manufacturer and selling to the customers. We study the problem with the deterministic demand. We develop an efficient algorithm to find the joint optimal policy for three prices: …

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Risk Response Strategies In The Supply Chain: Examining Attributes Of Stakeholders And Risk Attitude, Shu Jian Lim Jan 2010

Risk Response Strategies In The Supply Chain: Examining Attributes Of Stakeholders And Risk Attitude, Shu Jian Lim

Dissertations and Theses Collection (Open Access)

Supply chain management is about managing flows of material, information and funds in a complex network of entities of suppliers, manufacturers, distributors and customers. Companies are now connected in this network as an extended enterprise and any company may be involved in more than one such extended enterprises. But, such a network of relationships is very much vulnerable to disruptions of all sorts ranging from internal to inter-firm and to external turbulences. Companies now need to be prepared for risks associated with their participation in the supply chain network. Not many works in the literature have used theories to study …

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Pricing And Lead Time Decisions In A Duopoly Common Retailer Channel, Xiuming Niu Jan 2010

Pricing And Lead Time Decisions In A Duopoly Common Retailer Channel, Xiuming Niu

Dissertations and Theses Collection (Open Access)

This thesis studies a dual-level decentralized supply chain consisting of two suppliers and two retailers facing a price- and lead-time-sensitive demand. We model the suppliers’ operations as M/M/1 queues and demand as a linear function of the retail prices and promised delivery lead-times offered to the customers. Three different kinds of games are constructed to analyze the pricing and lead-time decisions of the suppliers and retailers. We show the existence of a unique equilibrium in all games and provide the exact formulas to compute the optimal decisions for both the suppliers and retailers. We further present numerical examples to illustrate …

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Procure Financing For Shipping By Auctions, Kekun Wu Jan 2010

Procure Financing For Shipping By Auctions, Kekun Wu

Dissertations and Theses Collection (Open Access)

We study a risk management problem in the scenario of ship procurement. A shipping firm faces a certain financing pressure for the procurement of a new ship. On the other hand, the capacity of the ship excesses the demand requirement of the firm. The firm wants to reduce the payment and control the risk by selling a percentage of capacity to another shipping company. We introduce an auction mechanism for the firm to select the partner and determine the sharing percentage. Acting as the auctioneer, the firm announces a certain percentage of capacity to a set of buyers. The payment …

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