Pedagogies of Experience: A Case of the African American Male Teacher

ERIC Educational Resources Information Center

Brown, Anthony L.

2011-01-01

Numerous scholars have illustrated how African American teachers' past experiences provide them a philosophical vision committed to teaching for social and educational change for African American students. This article draws from this body of work by looking at the diverse ways five African American male teachers used their past experiences to…

Magnetotelluric data collected to characterize aquifers in the San Luis Basin, New Mexico

USGS Publications Warehouse

Ailes, Chad E.; Rodriguez, Brian D.

2015-01-01

The U.S. Geological Survey is conducting a series of multidisciplinary studies of the San Luis Basin as part of the Geologic Framework of Rio Grande Basins project. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, magnetotelluric surveys, and hydrologic and lithologic data are being used to better understand the aquifers in the San Luis Basin. This report describes one north-south and two east-west regional magnetotelluric sounding profiles, acquired in June of 2010 and July and August of 2011, across the San Luis Basin in northern New Mexico. No interpretation of the data is included.

Geophysical constraints on Rio Grande rift structure and stratigraphy from magnetotelluric models and borehole resistivity logs, northern New Mexico

USGS Publications Warehouse

Rodriguez, Brian D.; Sawyer, David A.; Hudson, Mark R.; Grauch, V.J.S.

2013-01-01

Two- and three-dimensional electrical resistivity models derived from the magnetotelluric method were interpreted to provide more accurate hydrogeologic parameters for the Albuquerque and Española Basins. Analysis and interpretation of the resistivity models are aided by regional borehole resistivity data. Examination of the magnetotelluric response of hypothetical stratigraphic cases using resistivity characterizations from the borehole data elucidates two scenarios where the magnetotelluric method provides the strongest constraints. In the first scenario, the magnetotelluric method constrains the thickness of extensive volcanic cover, the underlying thickness of coarser-grained facies of buried Santa Fe Group sediments, and the depth to Precambrian basement or overlying Pennsylvanian limestones. In the second scenario, in the absence of volcanic cover, the magnetotelluric method constrains the thickness of coarser-grained facies of buried Santa Fe Group sediments and the depth to Precambrian basement or overlying Pennsylvanian limestones. Magnetotelluric surveys provide additional constraints on the relative positions of basement rocks and the thicknesses of Paleozoic, Mesozoic, and Tertiary sedimentary rocks in the region of the Albuquerque and Española Basins. The northern extent of a basement high beneath the Cerros del Rio volcanic field is delineated. Our results also reveal that the largest offset of the Hubbell Spring fault zone is located 5 km west of the exposed scarp. By correlating our resistivity models with surface geology and the deeper stratigraphic horizons using deep well log data, we are able to identify which of the resistivity variations in the upper 2 km belong to the upper Santa Fe Group sediment

The IRETHERM Project: How Can We Characterize Geothermal Reservoirs in Ireland using Magnetotelluric Surveying?

NASA Astrophysics Data System (ADS)

Delhaye, R. P.; Jones, A. G.; Rath, V.; Brown, C.; Reay, D.

2014-12-01

We present results from two geophysical investigations of the north of Ireland, one of a concealed sedimentary basin and the other of an area of pre- to mid-Cambrian metasedimentary material with local microseismicity in Donegal. Magnetotelluric data have been acquired over each area as part of the IRETHERM Project in order to assess potential low-enthalpy geothermal resources. In addition, airborne frequency-domain EM response data have been used to assist in the definition of near-surface electrical structure and constraint of magnetotelluric modeling. The Rathlin Basin in Northern Ireland was identified as a potential geothermal resource due both an elevated geothermal gradient (observed in two deep boreholes) and favorable hydraulic properties in thick successions of Permian and Triassic sandstones (measured from core samples). Prior seismic experiments failed to fully image the sediments beneath the overlying flood basalt. A new experiment applying the magnetotelluric method has had more success, as the MT signal is not dissipated by the crystalline overburden. MT data were acquired at 69 sites across the north-eastern portion of the onshore Rathlin Basin and on nearby Rathlin Island in order to image the thickness, depth, and lateral continuity of the target sediments. Analyses and modeling of the data have determined a resistivity model that maps the variation in thickness of the sediment fill and the truncation of the sediments against the structurally-controlling Tow Valley Fault. Further testing of the model sensitivity to variations of the thickness of the Sherwood Sandstone Group within the sediment fill has also been performed, as the overlying sediments have lower porosities and permeabilities from core sampling. Microseismicity in a metasedimentary area of northern Donegal suggests that secondary porosity distributions along fracture planes may have been augmented, leading to elevated electrical conductivity. MT data were acquired over the epicenter

Magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

USGS Publications Warehouse

Rodriguez, Brian D.; Sampson, Jay A.

2010-01-01

The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size and resistivity of the mineralized area beneath overburden, a regional east-west magnetotelluric sounding profile was acquired. This is a data release report of the magnetotelluric sounding data collected along the east-west profile; no interpretation of the data is included.

Magnetotelluric survey to locate the Archean-Proterozoic suture zone in the northeastern Great Basin, Nevada, Utah, and Idaho

USGS Publications Warehouse

Sampson, Jay A.; Rodriguez, Brian D.

2013-01-01

North-central Nevada contains a large amount of gold in linear belts, the origin of which is not fully understood. During July 2008, September 2009, and August 2010, the U.S. Geological Survey, as part of the Assessment Techniques for Concealed Mineral Resources project, collected twenty-three magnetotelluric soundings along two profiles in Box Elder County, Utah; Elko County, Nevada; and Cassia, Minidoka, and Blaine Counties, Idaho. The main twenty-sounding north-south magnetotelluric profile begins south of Wendover, Nev., but north of the Deep Creek Range. It continues north of Wendover and crosses into Utah, with the north profile terminus in the Snake River Plain, Idaho. A short, three-sounding east-west segment crosses the main north-south profile near the northern terminus of the profile. The magnetotelluric data collected in this study will be used to better constrain the location and strike of the concealed suture zone between the Archean crust and the Paleoproterozoic Mojave province. This report releases the magnetotelluric sounding data that was collected. No interpretation of the data is included.

Marine magnetotelluric inversion with an unstructured tetrahedral mesh

NASA Astrophysics Data System (ADS)

Usui, Yoshiya; Kasaya, Takafumi; Ogawa, Yasuo; Iwamoto, Hisanori

2018-05-01

The finite element method using an unstructured tetrahedral mesh is one of the most effective methods for the three-dimensional modelling of marine magnetotelluric data which are strongly affected by bathymetry, because it enables us to incorporate both small-scale and regional-scale bathymetry into a computational mesh with a practical number of elements. The authors applied a three-dimensional inversion scheme using mesh of this type to marine magnetotelluric problems for the first time and verified its applicability. Forward calculations for two bathymetry models demonstrated that the results obtained with an unstructured tetrahedral mesh are close to the reference solutions. To evaluate the forward calculation results, we developed a general TM-mode analytical formulation for a two-dimensional sinusoidal topography. Moreover, synthetic inversion test results confirmed that a three-dimensional inversion scheme with an unstructured tetrahedral mesh enables us to recover subseafloor resistivity structure properly even for a model including a land-sea boundary as well as seafloor undulations. The verified inversion scheme was subsequently applied to a set of marine magnetotelluric data observed around the Iheya North Knoll, the middle Okinawa Trough. Three-dimensional modelling using a mesh with precise bathymetry demonstrated that the data observed around the Iheya North Knoll are strongly affected by bathymetry, especially by the sea-depth differences between the depression of the trough and the shallow East China Sea. The estimated resistivity structure under the knoll is characterized by a conductive surface layer underlain by a resistive layer. The conductive layer implies permeable pelagic/hemi-pelagic sediments, which are consistent with a previous seismological study. Furthermore, the conductive layer has a resistive part immediately below the knoll, which is regarded as the consolidated magma intrusion that formed the knoll. Furthermore, at depth of 10 km

Semiautomatic and Automatic Cooperative Inversion of Seismic and Magnetotelluric Data

NASA Astrophysics Data System (ADS)

Le, Cuong V. A.; Harris, Brett D.; Pethick, Andrew M.; Takam Takougang, Eric M.; Howe, Brendan

2016-09-01

Natural source electromagnetic methods have the potential to recover rock property distributions from the surface to great depths. Unfortunately, results in complex 3D geo-electrical settings can be disappointing, especially where significant near-surface conductivity variations exist. In such settings, unconstrained inversion of magnetotelluric data is inexorably non-unique. We believe that: (1) correctly introduced information from seismic reflection can substantially improve MT inversion, (2) a cooperative inversion approach can be automated, and (3) massively parallel computing can make such a process viable. Nine inversion strategies including baseline unconstrained inversion and new automated/semiautomated cooperative inversion approaches are applied to industry-scale co-located 3D seismic and magnetotelluric data sets. These data sets were acquired in one of the Carlin gold deposit districts in north-central Nevada, USA. In our approach, seismic information feeds directly into the creation of sets of prior conductivity model and covariance coefficient distributions. We demonstrate how statistical analysis of the distribution of selected seismic attributes can be used to automatically extract subvolumes that form the framework for prior model 3D conductivity distribution. Our cooperative inversion strategies result in detailed subsurface conductivity distributions that are consistent with seismic, electrical logs and geochemical analysis of cores. Such 3D conductivity distributions would be expected to provide clues to 3D velocity structures that could feed back into full seismic inversion for an iterative practical and truly cooperative inversion process. We anticipate that, with the aid of parallel computing, cooperative inversion of seismic and magnetotelluric data can be fully automated, and we hold confidence that significant and practical advances in this direction have been accomplished.

Cataloging the Pan-African Experience

ERIC Educational Resources Information Center

Hayes, Dianne

2012-01-01

Of all the honors and accolades bibliophile and noted authority on the Underground Railroad Charles Blockson has received, being bequeathed recently with some of Harriet Tubman's personal items by her great-niece is one of the most significant experiences of his life. A longtime collector of books and rare items by and about African-Americans,…

Enhancement of Signal-to-noise Ratio in Natural-source Transient Magnetotelluric Data with Wavelet Transform

NASA Astrophysics Data System (ADS)

Zhang, Y.; Paulson, K. V.

For audio-frequency magnetotelluric surveys where the signals are lightning-stroke transients, the conventional Fourier transform method often fails to produce a high quality impedance tensor. An alternative approach is to use the wavelet transform method which is capable of localizing target information simultaneously in both the temporal and frequency domains. Unlike Fourier analysis that yields an average amplitude and phase, the wavelet transform produces an instantaneous estimate of the amplitude and phase of a signal. In this paper a complex well-localized wavelet, the Morlet wavelet, has been used to transform and analyze audio-frequency magnetotelluric data. With the Morlet wavelet, the magnetotelluric impedance tensor can be computed directly in the wavelet transform domain. The lightning-stroke transients are easily identified on the dilation-translation plane. Choosing those wavelet transform values where the signals are located, a higher signal-to-noise ratio estimation of the impedance tensor can be obtained. In a test using real data, the wavelet transform showed a significant improvement in the signal-to-noise ratio over the conventional Fourier transform.

Robust Magnetotelluric Impedance Estimation

NASA Astrophysics Data System (ADS)

Sutarno, D.

2010-12-01

Robust magnetotelluric (MT) response function estimators are now in standard use by the induction community. Properly devised and applied, these have ability to reduce the influence of unusual data (outliers). The estimators always yield impedance estimates which are better than the conventional least square (LS) estimation because the `real' MT data almost never satisfy the statistical assumptions of Gaussian distribution and stationary upon which normal spectral analysis is based. This paper discuses the development and application of robust estimation procedures which can be classified as M-estimators to MT data. Starting with the description of the estimators, special attention is addressed to the recent development of a bounded-influence robust estimation, including utilization of the Hilbert Transform (HT) operation on causal MT impedance functions. The resulting robust performances are illustrated using synthetic as well as real MT data.

Magnetotellurics with long distance remote reference to reject DC railway noise

NASA Astrophysics Data System (ADS)

Hanstein, T.; Jiang, J.; Strack, K.; Ritter, O.

2014-12-01

Some parts of railway network in Europe is electrified by DC current. The return current in the ground is varying in space, time and power when the train is moving. Since the train traffic is active 24 hours, there is no quite time. The train signal is dominating for periods longer than 1 s and is a near field source. The transfer function of the magnetotelluric sounding (MT) is influenced by this near field source, the phase is going to zero and amplitude increase with slope 1 for longer periods. Since this dominating noise is present all day robust magnetotelluric processing technique to identify and remove outliers are not applicable and sufficient. The remote reference technique has successfully been applied for magnetotelluric soundings Combining an disturbed local MT data set with the data of the remote station, which is recording simultaneously the horizontal magnetic fields, can improve the data quality. Finding a good remote station during field survey is difficult and expensive. There is a permanent MT remote reference station in Germany. The set up and maintance is done by the GFZ - Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences. The location is near Wittstock and has good signal-to-noise-ratio with low cutural noise, the ground is almost lD and recording since May 2010. The electric and magnetic field is continously recorded with 250 Hz sampling and induction coils. The magnetic field is also recorded with fluxgate magnetometers and 5 Hz sampling. The distance to the local MT site is about 600 km.

Ogbu Revisited: Unpacking High-Achieving African American Girls' High School Experiences

ERIC Educational Resources Information Center

Archer-Banks, Diane A. M.; Behar-Horenstein, Linda S.

2012-01-01

How African American girls cope and excel amidst the discriminations and inequities they experience within U.S. educational systems has not been widely discussed in the body of research about African Americans' schooling experiences. In this study, the researchers examined the applicability of Ogbu's cultural-ecological theory to the…

Audio-magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

USGS Publications Warehouse

Sampson, Jay A.; Rodriguez, Brian D.

2010-01-01

The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size, resistivity, and skin depth of the polarizable mineral deposit concealed beneath thick overburden, a regional east-west audio-magnetotelluric sounding profile was acquired. The purpose of this report is to release the audio-magnetotelluric sounding data collected along that east-west profile. No interpretation of the data is included.

Black African Parents' Experiences of an Educational Psychology Service

ERIC Educational Resources Information Center

Lawrence, Zena

2014-01-01

The evidence base that explores Black African parents' experiences of an Educational Psychology Service (EPS) is limited. This article describes an exploratory mixed methods research study undertaken during 2009-2011, that explored Black African parents' engagement with a UK EPS. Quantitative data were gathered from the EPS preschool database and…

Audio-magnetotelluric data collected in the area of Beatty, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, J.M.

1998-11-01

In the summer of 1997, electrical geophysical data was collected north of Beatty, Nevada. Audio-magnetotellurics (AMT) was the geophysical method used to collect 16 stations along two profiles. The purpose of this data collection was to determine the depth to the alluvial basement, based upon the needs of the geologists requesting the data.

Interpretation of magnetotelluric measurements over an electrically dispersive one-dimensional earth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patella, D.

1987-01-01

Frequency dispersion of electromagnetic parameters of earth materials has been widely documented in recent years. It is claimed that magnetotellurics (MT)may be significantly affected by dispersion. This paper studies the MT plane-wave interpretative problem for a one-dimensional earth characterized by the presence of dispersive layers. The theoretical properties of the MT field under the dispersion hypothesis, and the main features of the dispersion phenomenon are synthetically reviewed. The examination of previously published MT curve responses over some models of dispersive earth section shows that ambiguity can arise when interpreting MT data with no other source of information. Thus it maybemore » almost impossible to distinguish between the response of a dispersive section and an equally probable dispersion-free section. The dispersion magnetotelluric (DMT) method is proposed as a means to resolve the ambiguity. The DMT method is based on the execution, at the same site, of an MT sounding and of an always dispersion-free dc geoelectric deep sounding.« less

Freshman-year experiences for African-American students in engineering

NASA Astrophysics Data System (ADS)

Chapple, Bernadette Maria

1998-12-01

The purpose of this study was to discover (a) why African American students choose to persist as an engineering major and (b) why students choose to leave engineering as a major. A total of 17 students from a large land-grant university participated in this study that was both quantitative and qualitative in design. This research will assist both the College of Engineering and the University in understanding the educational experiences of the matriculating African American pre-engineering student. In an effort to provide reasons and rationale for why African American engineering students choose to stay in this major and why other African American engineering student majors choose to leave, the researcher examined an undergraduate engineering program at a large land-grant institution in the South. The College of Engineering at this institution was able to institute several programs designed to increase the number of African American students choosing engineering as a major. Although initiatives for pre-collegiate students are important in the retention of African American students, it is the retention of those students once accepted into a program of study that the institution focuses on most. It is the intent of this study to offer a better understanding of such a retention initiative. Due to the decline of African American students pursuing majors in science and mathematics in general and in engineering in particular, an important research concern is to offer more insight into the experiences of the freshman engineering student in an attempt to develop fundamental reasons for why students remain in engineering and why some students leave. To assist the College of Engineering and the University in understanding the educational experiences of the matriculating African American pre-engineering student the data were collected from both a quantitative and qualitative approach. Results indicated that (a) students who chose to persist in the engineering program where

Young African American Male-Male Relationships: Experiences, Expectations, and Condom Use

ERIC Educational Resources Information Center

Taggart, Tamara; Ellen, Jonathan; Arrington-Sanders, Renata

2017-01-01

HIV disproportionately impacts young African American men who have sex with men (MSM). In this study, we sought to understand how previous relationship experiences and expectations for romantic relationships influence condom use among young African American MSM. Twenty African American MSM aged 16 to 24 years completed a semi-structured interview…

Hydrocarbon Reservoir Identification in Volcanic Zone by using Magnetotelluric and Geochemistry Information

NASA Astrophysics Data System (ADS)

Firda, S. I.; Permadi, A. N.; Supriyanto; Suwardi, B. N.

2018-03-01

The resistivity of Magnetotelluric (MT) data show the resistivity mapping in the volcanic reservoir zone and the geochemistry information for confirm the reservoir and source rock formation. In this research, we used 132 data points divided with two line at exploration area. We used several steps to make the resistivity mapping. There are time series correction, crosspower correction, then inversion of Magnetotelluric (MT) data. Line-2 and line-3 show anomaly geological condition with Gabon fault. The geology structure from the resistivity mapping show the fault and the geological formation with the geological rock data mapping distribution. The geochemistry information show the maturity of source rock formation. According to core sample analysis information, we get the visual porosity for reservoir rock formation in several geological structure. Based on that, we make the geological modelling where the potential reservoir and the source rock around our interest area.

African American women's experiences with the initial discovery, diagnosis, and treatment of breast cancer.

PubMed

Lackey, N R; Gates, M F; Brown, G

2001-04-01

To describe the experiences of African American women living with breast cancer following the primary diagnosis and while undergoing initial treatment. Phenomenologic. 13 African American women (ages 30-66) purposefully selected from two oncology clinics in the mid-South. Phenomenologic interviews (transcribed verbatim) and field notes were analyzed using Colaizzi's method of phenomenologic description and analysis. Experience Trajectory, Femininity, and Spirituality were the three major themes. The Experience Trajectory subthemes were finding the lump, getting the diagnosis, undergoing surgery and adjuvant treatment. The Femininity subthemes were loss of all or part of the breast, loss of hair, and sexual attractiveness to a man. Spirituality was reflected as a reliance on God. Telling the story of their experience trajectory during their breast cancer experience is valuable in assessing African American women's feelings, emotions, and fears of body changes that occur during surgery and treatment. Their spirituality helps them through this experience. Research involving both African American women and their partners would provide greater insight into specific relationship patterns and communication related to sexuality during this experience. Nurses need to listen to the stories of African American women about the initial experience of discovery, diagnosis, and treatment of breast cancer so they can be more informed advocates for these women. African American women need more information from healthcare providers regarding the whole experience trajectory.

African American Parental Involvement in Their Children's Middle School Experiences

ERIC Educational Resources Information Center

Archer-Banks, Diane A. M.; Behar-Horenstein, Linda S.

2008-01-01

The purpose of this study was to determine the factors that influence African American parents' involvement in their children's middle school experiences. Two focus group interviews were conducted with African American parents. While the participants viewed parent involvement as important, they reported that family structure and socioeconomic…

African American Women's Breastfeeding Experiences: Cultural, Personal, and Political Voices.

PubMed

Spencer, Becky; Wambach, Karen; Domain, Elaine Williams

2015-07-01

The low rate of breastfeeding among African American women in the United States is a poorly understood, persistent disparity. Our purpose in this study was to gain an understanding of how African American women experience breastfeeding in the context of their day-to-day lives. The Sequential-Consensual Qualitative Design (SCQD), a 3-stage qualitative methodology aimed at exploring the cultural, personal, and political context of phenomena, was used to explore the experiences of African American women who felt successful with breastfeeding. An integration of qualitative content analysis and Black feminist theory was used to analyze the data. Themes that emerged from Stage-2 data analysis included self-determination, spirituality and breastfeeding, and empowerment. In Stage 3 of the study, participant recommendations regarding breastfeeding promotion and support initiatives for African American breastfeeding were categorized into three themes, including engaging spheres of influence, sparking breastfeeding activism, and addressing images of the sexual breast vs. the nurturing breast. © The Author(s) 2014.

2-D magnetotelluric experiment to investigate the Nassugtoqidian orogeny in South-East Greenland

NASA Astrophysics Data System (ADS)

Heincke, Björn; Chen, Jin; Riisager, Peter; Kolb, Jochen; Jørgensen, Asta F.

2015-04-01

The northwest-trending Palaeoproterozoic Nagssugtoqidian orogen extends over 250 km along the east coast of Greenland in the area around the village Tasiilaq. The geological evolution of this area closely compares with the ones of the Lewisian complex of Scotland and the Nagssugtoqidian orogen in western Greenland and, hence, leads to the suggestion that they belong to the same continental-scale orogenic belt. However, an accurate correlation across the inland ice is challenging and still ambiguous and therefore more detailed knowledge about the individual orogens might help to understand their relationship. Details about the large-scale tectonic evolution during the Nagssugtoqidian orogeny in this remote Arctic region are not known due to complex geology, relatively coarse geological mapping and the lack of extensive geophysical investigations. E.g. the vergence of the orogen, subduction-related magmatism and accretion history are matters of ongoing discussion (Kalsbeek et al., 1993; Nutman et al., 2008 and Kolb, 2013). We performed a 2-D magnetotelluric (MT) experiment across the southern part of the orogen along the Sermilik Fjord in order to improve our understanding of the orogenic process in general and to better constrain the location and vergence of the suture zone. However, because of the rough climate and the lack of infrastructure, this study is considered as a first test to investigate how MT surveys can be most efficiently performed in this remote part of the world. The NE-SW trending profile consists of eight MT stations and has a total length of ~70 km using long period LEMI-420 systems. The quality of the data is severely affected by polar electrojets that do not satisfy the plane wave assumptions, which is typical for regions close to the magnetic poles. In order to reduce the distortion from these signals onto the impedance estimates, we tested different advanced processing schemes. In addition to the more conventional robust response function

Detection and characterization of lightning-based sources using continuous wavelet transform: application to audio-magnetotellurics

NASA Astrophysics Data System (ADS)

Larnier, H.; Sailhac, P.; Chambodut, A.

2018-01-01

Atmospheric electromagnetic waves created by global lightning activity contain information about electrical processes of the inner and the outer Earth. Large signal-to-noise ratio events are particularly interesting because they convey information about electromagnetic properties along their path. We introduce a new methodology to automatically detect and characterize lightning-based waves using a time-frequency decomposition obtained through the application of continuous wavelet transform. We focus specifically on three types of sources, namely, atmospherics, slow tails and whistlers, that cover the frequency range 10 Hz to 10 kHz. Each wave has distinguishable characteristics in the time-frequency domain due to source shape and dispersion processes. Our methodology allows automatic detection of each type of event in the time-frequency decomposition thanks to their specific signature. Horizontal polarization attributes are also recovered in the time-frequency domain. This procedure is first applied to synthetic extremely low frequency time-series with different signal-to-noise ratios to test for robustness. We then apply it on real data: three stations of audio-magnetotelluric data acquired in Guadeloupe, oversea French territories. Most of analysed atmospherics and slow tails display linear polarization, whereas analysed whistlers are elliptically polarized. The diversity of lightning activity is finally analysed in an audio-magnetotelluric data processing framework, as used in subsurface prospecting, through estimation of the impedance response functions. We show that audio-magnetotelluric processing results depend mainly on the frequency content of electromagnetic waves observed in processed time-series, with an emphasis on the difference between morning and afternoon acquisition. Our new methodology based on the time-frequency signature of lightning-induced electromagnetic waves allows automatic detection and characterization of events in audio-magnetotelluric

Enhancement of subsurface geologic structure model based on gravity, magnetotelluric, and well log data in Kamojang geothermal field

NASA Astrophysics Data System (ADS)

Yustin Kamah, Muhammad; Armando, Adilla; Larasati Rahmani, Dinda; Paramitha, Shabrina

2017-12-01

Geophysical methods such as gravity and magnetotelluric methods commonly used in conventional and unconventional energy exploration, notably for exploring geothermal prospect. They used to identify the subsurface geology structures which is estimated as a path of fluid flow. This study was conducted in Kamojang Geothermal Field with the aim of highlighting the volcanic lineament in West Java, precisely in Guntur-Papandayan chain where there are three geothermal systems. Kendang Fault has predominant direction NE-SW, identified by magnetotelluric techniques and gravity data processing techniques. Gravity techniques such as spectral analysis, derivative solutions, and Euler deconvolution indicate the type and geometry of anomaly. Magnetotelluric techniques such as inverse modeling and polar diagram are required to know subsurface resistivity charactersitics and major orientation. Furthermore, the result from those methods will be compared to geology information and some section of well data, which is sufficiently suitable. This research is very useful to trace out another potential development area.

Magnetotelluric Data, Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada

USGS Publications Warehouse

Williams, Jackie M.; Sampson, Jay A.; Rodriguez, Brian D.; Asch, Theodore H.

2006-01-01

Introduction: The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. During 2005, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data from twenty-six magnetotelluric (MT) and audio-magnetotelluric (AMT) sites at the Nevada Test Site. The 2005 data stations were located on and near Rainier Mesa and Shoshone Mountain to assist in characterizing the pre-Tertiary geology in those areas. These new stations extend the area of the hydrogeologic study previously conducted in Yucca Flat. The MT data presented in this report will help refine what is known about the character, thickness, and lateral extent of pre Tertiary confining units. Subsequent interpretation will include a three dimensional (3 D) character analysis and a two-dimensional (2 D) resistivity model. The purpose of this report is to release the MT sounding data. No interpretation of the data is included here.

An Examination of African American Female College Presidents' Professional Ascendancy and Mentoring Experiences

ERIC Educational Resources Information Center

Smith-Ligon, Pamela

2011-01-01

There is a large disparity in the number of African American women leaders in higher education, specifically in the presidency. Much of the literature negates the experiences of the African American woman, often fusing their experiences with those of all women, or those of African American men, which often disregards the challenges and successes…

Raw Magnetotelluric Data, McGregory Range, Fort Bliss, New Mexico

DOE Data Explorer

Nash, Greg

2017-01-01

This is a zipped file containing raw magnetotelluric (MT) data collected as part of the Phase 2 Tularosa Basin geothermal play fairway analysis project in New Mexico. The data for each MT station are in standard .edi text files which are accompanied by graphic files illustrating details. These data cover part of McGregor Range, Fort Bliss, New Mexico. The MT survey was done by Quantec Geoscience.

Research on maximum level noise contaminated of remote reference magnetotelluric measurements using synthesized data

NASA Astrophysics Data System (ADS)

Gang, Zhang; Fansong, Meng; Jianzhong, Wang; Mingtao, Ding

2018-02-01

Determining magnetotelluric impedance precisely and accurately is fundamental to valid inversion and geological interpretation. This study aims to determine the minimum value of signal-to-noise ratio (SNR) which maintains the effectiveness of remote reference technique. Results of standard time series simulation, addition of different Gaussian noises to obtain the different SNR time series, and analysis of the intermediate data, such as polarization direction, correlation coefficient, and impedance tensor, show that when the SNR value is larger than 23.5743, the polarization direction disorder at morphology and a smooth and accurate sounding carve value can be obtained. At this condition, the correlation coefficient value of nearly complete segments between the base and remote station is larger than 0.9, and impedance tensor Zxy presents only one aggregation, which meet the natural magnetotelluric signal characteristic.

West Flank Coso FORGE Magnetotelluric 3D Data

DOE Data Explorer

Doug Blankenship

2016-01-01

This is the 3D version of the MT data for the West Flank FORGE area.The Coso geothermal field has had three Magnetotelluric (MT) datasets collected including surveys in 2003, 2006, and 2011. The final collection, in 2011, expanded the survey to the west and covers the West Flank of FORGE area.This most recent data set was collected by Schlumberger/WesternGeco and inverted by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy; the 2003 and 2006 data were integrated for these inversions in the present study.

Psychopathology, adversity, and creativity: diversifying experiences in the development of eminent African Americans.

PubMed

Damian, Rodica Ioana; Simonton, Dean Keith

2015-04-01

Symptoms associated with mental illness have been hypothesized to relate to creative achievement because they act as diversifying experiences. However, this theory has only been tested on predominantly majority-culture samples. Do tendencies toward mental illness still predict eminent creativity when they coexist with other diversifying experiences, such as early parental death, minority-status, or poverty? These alternative diversifying experiences can be collectively referred to as examples of developmental adversity. This conjecture was tested on a significant sample of 291 eminent African Americans who, by the nature of their status as long-term minorities, would experience more developmental adversity. Replicating majority-culture patterns, African American artists showed higher mental illness rates than African American scientists. Yet the absolute percentages were significantly lower for the African Americans, regardless of profession. Furthermore, mental illness predicted higher eminence levels only for the African American artists, an effect that diminished when controlling for developmental adversity. Because the latter predicted eminence for both artists and scientists, the "madness-to-genius" link probably represents just 1 of several routes by which diversifying experiences can influence eminence. The same developmental ends can be attained by different means. This inference warrants further research using other eminent creators emerging from minority culture populations. (c) 2015 APA, all rights reserved).

"Nobody ever asked me before": understanding life experiences of African American elders.

PubMed

Shellman, Juliette

2004-10-01

With the unprecedented growth in the African American elderly population, there exists an urgent need to prepare nurses to deliver culturally competent care. The purpose of this study was to increase the knowledge available about the cultural heritage, worldviews, and life experiences of African American elders. Reminiscence interviews were conducted with African American elders living in a medium-sized northeast urban community. Data were analyzed using Spiegelberg's phenomenological Method. The following themes emerged: (a) nobody ever asked me before, (b) stories of discrimination, (c) coping with discrimination, (d) the hurt of discrimination, and (e) self-discoveries. Nurses, through the use of reminiscence, can gain insight into the cultural heritage, worldviews, and life experiences of African American elders and improve their ability to deliver culturally competent care to this population.

Three dimensional topography correction applied to magnetotelluric data from Sikkim Himalayas

NASA Astrophysics Data System (ADS)

Kumar, Sushil; Patro, Prasanta K.; Chaudhary, B. S.

2018-06-01

Magnetotelluric (MT) method is one of the powerful tools to investigate the deep crustal image of mountainous regions such as Himalayas. Topographic variations due to irregular surface terrain distort the resistivity curves and hence may not give accurate interpretation of magnetotelluric data. The two-dimensional (2-D) topographic effects in Transverse Magnetic (TM) mode is only galvanic whereas inductive in Transverse Electric (TE) mode, thus TM mode responses is much more important than TE mode responses in 2-D. In three-dimensional (3-D), the topography effect is both galvanic and inductive in each element of impedance tensor and hence the interpretation is complicated. In the present work, we investigate the effects of three-dimensional (3-D) topography for a hill model. This paper presents the impedance tensor correction algorithm to reduce the topographic effects in MT data. The distortion caused by surface topography effectively decreases by using homogeneous background resistivity in impedance correction method. In this study, we analyze the response of ramp, distance from topographic edges, conductive and resistive dykes. The new correction method is applied to the real data from Sikkim Himalayas, which brought out the true nature of the basement in this region.

Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data

USGS Publications Warehouse

Unsworth, M.J.; Jones, A.G.; Wei, W.; Marquis, G.; Gokarn, S.G.; Spratt, J.E.; Bedrosian, P.; Booker, J.; Leshou, C.; Clarke, G.; Shenghui, L.; Chanhong, L.; Ming, D.; Sheng, J.; Solon, K.; Handong, T.; Ledo, J.; Roberts, B.

2005-01-01

The Cenozoic collision between the Indian and Asian continents formed the Tibetan plateau, beginning about 70 million years ago. Since this time, at least 1,400 km of convergence has been accommodated by a combination of underthrusting of Indian and Asian lithosphere, crustal shortening, horizontal extrusion and lithospheric delamination. Rocks exposed in the Himalaya show evidence of crustal melting and are thought to have been exhumed by rapid erosion and climatically forced crustal flow. Magnetotelluric data can be used to image subsurface electrical resistivity, a parameter sensitive to the presence of interconnected fluids in the host rock matrix, even at low volume fractions. Here we present magnetotelluric data from the Tibetan-Himalayan orogen from 77??E to 92??E, which show that low resistivity, interpreted as a partially molten layer, is present along at least 1,000 km of the southern margin of the Tibetan plateau. The inferred low viscosity of this layer is consistent with the development of climatically forced crustal flow in Southern Tibet. ?? 2005 Nature Publishing Group.

Long regional magnetotelluric profile crossing geotectonic structures of central Poland

NASA Astrophysics Data System (ADS)

Stefaniuk, M.; Pokorski, J.; Wojdyla, M.

2009-04-01

Introduction The magnetotelluric survey was made along a regional profile, which runs across Poland from south-west to north-east during 2005-2006 years. The profile crosses major geological structures of Central Poland, including the Variscan Externides and Variscan foredeep, the Transeuropean Suture Zone and the marginal zone of East European Craton. The main objectives of the project include identification of sub-Zechstein sedimentary structures and evaluation of resistivity distribution within the deep crust, especially at the contact of East European Precambrian Craton and Central Europe Paleozoic structures. The length of the profile is about 700 km; 161 deep magnetotelluric sounding sites were made with a medium spacing of about 4 km. Data acquisition and processing The recording of the components of natural electromagnetic field was made with a broad range of frequencies, varying from 0.0003 Hz up to 575 Hz with use of MT-1 system of Electromagnetic Instruments Incorporation. This frequency band allowed obtaining the information about geology ranging from a few dozen meters to approximately 100 km, depending on the vertical distribution of the resistivity inside geological medium. To reduce the electromagnetic noise, magnetic and electric remote reference was applied. A remote reference site was located at a distance of over 100 km of field sites. Processing of the recorded data included the estimation of the components of impedance tensor (Zxx, Zxy, Zyx and Zyy ), with use of robust type procedures. The components of the impedance tensor allowed in a subsequent step for calculation of field curves for two orientations of the measurement system (XY - described further as the TM mode and YX - TE mode) and additional parameters of the medium like skew, strike, pole diagrams etc. Recording of the vertical component of electromagnetic field (Hz) allowed calculation of tipper parameter T. Magnetotelluric soundings interpretation Geophysical interpretation of MT

The Meaning of African American College Women's Experiences Attending a Predominantly White Institution: A Phenomenological Study

ERIC Educational Resources Information Center

Hannon, Christine R.; Woodside, Marianne; Pollard, Brittany L.; Roman, Jorge

2016-01-01

Because both race and gender are important to the development of African American women, student affairs professionals need to understand the unique experiences of African American women within the context of the college environment. In this phenomenological study, we examined African American women's lived experiences as college students at a…

Probabilistic 3-D time-lapse inversion of magnetotelluric data: application to an enhanced geothermal system

NASA Astrophysics Data System (ADS)

Rosas-Carbajal, M.; Linde, N.; Peacock, J.; Zyserman, F. I.; Kalscheuer, T.; Thiel, S.

2015-12-01

Surface-based monitoring of mass transfer caused by injections and extractions in deep boreholes is crucial to maximize oil, gas and geothermal production. Inductive electromagnetic methods, such as magnetotellurics, are appealing for these applications due to their large penetration depths and sensitivity to changes in fluid conductivity and fracture connectivity. In this work, we propose a 3-D Markov chain Monte Carlo inversion of time-lapse magnetotelluric data to image mass transfer following a saline fluid injection. The inversion estimates the posterior probability density function of the resulting plume, and thereby quantifies model uncertainty. To decrease computation times, we base the parametrization on a reduced Legendre moment decomposition of the plume. A synthetic test shows that our methodology is effective when the electrical resistivity structure prior to the injection is well known. The centre of mass and spread of the plume are well retrieved. We then apply our inversion strategy to an injection experiment in an enhanced geothermal system at Paralana, South Australia, and compare it to a 3-D deterministic time-lapse inversion. The latter retrieves resistivity changes that are more shallow than the actual injection interval, whereas the probabilistic inversion retrieves plumes that are located at the correct depths and oriented in a preferential north-south direction. To explain the time-lapse data, the inversion requires unrealistically large resistivity changes with respect to the base model. We suggest that this is partly explained by unaccounted subsurface heterogeneities in the base model from which time-lapse changes are inferred.

Probabilistic 3-D time-lapse inversion of magnetotelluric data: Application to an enhanced geothermal system

USGS Publications Warehouse

Rosas-Carbajal, Marina; Linde, Nicolas; Peacock, Jared R.; Zyserman, F. I.; Kalscheuer, Thomas; Thiel, Stephan

2015-01-01

Surface-based monitoring of mass transfer caused by injections and extractions in deep boreholes is crucial to maximize oil, gas and geothermal production. Inductive electromagnetic methods, such as magnetotellurics, are appealing for these applications due to their large penetration depths and sensitivity to changes in fluid conductivity and fracture connectivity. In this work, we propose a 3-D Markov chain Monte Carlo inversion of time-lapse magnetotelluric data to image mass transfer following a saline fluid injection. The inversion estimates the posterior probability density function of the resulting plume, and thereby quantifies model uncertainty. To decrease computation times, we base the parametrization on a reduced Legendre moment decomposition of the plume. A synthetic test shows that our methodology is effective when the electrical resistivity structure prior to the injection is well known. The centre of mass and spread of the plume are well retrieved.We then apply our inversion strategy to an injection experiment in an enhanced geothermal system at Paralana, South Australia, and compare it to a 3-D deterministic time-lapse inversion. The latter retrieves resistivity changes that are more shallow than the actual injection interval, whereas the probabilistic inversion retrieves plumes that are located at the correct depths and oriented in a preferential north-south direction. To explain the time-lapse data, the inversion requires unrealistically large resistivity changes with respect to the base model. We suggest that this is partly explained by unaccounted subsurface heterogeneities in the base model from which time-lapse changes are inferred.

Accustomed to enduring: experiences of African-American women seeking care for cardiac symptoms.

PubMed

Banks, Angela D; Malone, Ruth E

2005-01-01

Understand the meaning of delayed treatment seeking in African-American women with unstable angina and myocardial infarction. Phenomenologic analysis of in-depth interview data and field notes on 12 African-American women hospitalized with unstable angina or myocardial infarction. Women's interpretation of and response to symptoms were informed by experiences of marginalization and their self-understanding as people who were strong and who had endured life's hardships. When hospitalized, some women experienced trivialization of their complaints by clinicians and a focus on technological procedures over respectfully attending to their concerns, which provided further disincentives to seeking care. Three major themes emerged: misrecognition and discounting of symptoms, enduring, and influence of faith. Experiences of marginalization shape responses to symptoms, care-seeking behavior, and interpretation of subsequent care experiences for African-American women with cardiac disease, who may experience different symptoms as well as interpret them differently than members of other groups.

A Two-dimensional Version of the Niblett-Bostick Transformation for Magnetotelluric Interpretations

NASA Astrophysics Data System (ADS)

Esparza, F.

2005-05-01

An imaging technique for two-dimensional magnetotelluric interpretations is developed following the well known Niblett-Bostick transformation for one-dimensional profiles. The algorithm uses a Hopfield artificial neural network to process series and parallel magnetotelluric impedances along with their analytical influence functions. The adaptive, weighted average approximation preserves part of the nonlinearity of the original problem. No initial model in the usual sense is required for the recovery of a functional model. Rather, the built-in relationship between model and data considers automatically, all at the same time, many half spaces whose electrical conductivities vary according to the data. The use of series and parallel impedances, a self-contained pair of invariants of the impedance tensor, avoids the need to decide on best angles of rotation for TE and TM separations. Field data from a given profile can thus be fed directly into the algorithm without much processing. The solutions offered by the Hopfield neural network correspond to spatial averages computed through rectangular windows that can be chosen at will. Applications of the algorithm to simple synthetic models and to the COPROD2 data set illustrate the performance of the approximation.

African American High School Students' Perceptions of Their College Counseling Experience

ERIC Educational Resources Information Center

Turner, LaTonya M.

2017-01-01

This study looked at high school African American students' perceptions of their college counseling experiences. Much research has been done to highlight the views and/or perceptions of various stakeholders regarding college counseling with respect to African American students (Cabrera & La Nasa, 2000; Hossler & Stage, 1992; Ng,…

Three-dimensional inversion of magnetotelluric data for mineral exploration: An example from the McArthur River uranium deposit, Saskatchewan, Canada

NASA Astrophysics Data System (ADS)

Farquharson, Colin G.; Craven, James A.

2009-08-01

Shallow exploration targets are becoming scarce, meaning interest is turning towards deeper targets. The magnetotelluric method has the necessary depth capability, unlike many of the controlled-source electromagnetic prospecting techniques traditionally used. The geological setting of ore deposits is usually complex, requiring three-dimensional Earth models for their representation. An example of the applicability of three-dimensional inversion of magnetotelluric data to mineral exploration is presented here. Inversions of an audio-magnetotelluric data-set from the McArthur River uranium mine in the Athabasca Basin were carried out. A sub-set comprising data from eleven frequencies distributed over almost three decades was inverted. The form of the data used in the inversion was impedance. All four elements of the tensor were included. No decompositions of the data were done, nor rotation to a preferred strike direction, nor correction for static shifts. The inversions were successful: the observations were adequately reproduced and the main features in the conductivity model corresponded to known geological features. These included the graphitic basement fault along which the McArthur River uranium deposit is located.

The Experiences of Women Academics at a South African University.

ERIC Educational Resources Information Center

Petersen, N.; Gravett, S.

2000-01-01

Used in-depth, semi-structured interviews to explore the experiences of women academics at a South African university. Found positive and negative experiences: positives included the lessening of overt discrimination and flexible work hours. Negatives included the "double workload" of traditional female duties combined with work life and…

Experiences of African American Young Women in Science, Technology, Engineering, and Mathematics (STEM) Education

NASA Astrophysics Data System (ADS)

Kolo, Yovonda Ingram

African American women are underrepresented in science, technology, engineering, and mathematics (STEM) fields throughout the United States. As the need for STEM professionals in the United States increases, it is important to ensure that African American women are among those professionals making valuable contributions to society. The purpose of this phenomenological study was to describe the experiences of African American young women in relation to STEM education. The research question for this study examined how experiences with STEM in K-10 education influenced African American young women's academic choices in their final years in high school. The theory of multicontextuality was used to provide the conceptual framework. The primary data source was interviews. The sample was composed of 11 African American young women in their junior or senior year in high school. Data were analyzed through the process of open coding, categorizing, and identifying emerging themes. Ten themes emerged from the answers to research questions. The themes were (a) high teacher expectations, (b) participation in extra-curricular activities, (c) engagement in group-work, (d) learning from lectures, (e) strong parental involvement, (f) helping others, (g) self-efficacy, (h) gender empowerment, (i) race empowerment, and (j) strategic recruitment practices. This study may lead to positive social change by adding to the understanding of the experiences of African American young women in STEM. By doing so, these findings might motivate other African American young women to pursue advanced STEM classes. These findings may also provide guidance to parents and educators to help increase the number of African American women in STEM.

Experiences of African American and Caucasian women who survive urban residential fires.

PubMed

Jepson, C; Pickett, M; Keane, A; Tax, A; McCorkle, R

1996-01-01

This study examined differences in socioeconomic characteristics, traumatic experiences suffered, and psychological distress in African American and Caucasian women 3 months after urban residential fires. Distress was measured by the Brief Symptom Inventory (BSI). The sample included 310 women (224 African Americans and 86 Caucasians). The African American women had lower levels of education and income than the Caucasian women, and were more likely to be unmarried. Injury and deaths of loved ones were similar in the two groups; African American women reported greater loss of possessions, less insurance coverage, and less displacement than Caucasian women. African American and Caucasian women scored similarly on the BSI. Scores on the BSI for both groups were higher than the norms reported in the literature.

African-American Female Student Experiences in Community College

ERIC Educational Resources Information Center

Dozier, Nedra

2016-01-01

This is a mixed method study focusing on African-American Female (AAF) student experiences and success in the community college. This study was focused at a large southeastern, comprehensive community college. A chi-squared analysis of extant data concerning questions from the Community College Survey for Student Engagement (CCSSE) instrument was…

The African American Presence in Reading Intervention Experiments

ERIC Educational Resources Information Center

Lindo, Endia J.

2006-01-01

This study examined what proportion of reading intervention experiments published in a sample of prominent, peer-reviewed education research journals evaluated the impact of the reading intervention on African American students. The last 10 years of articles from the "Reading Research Quarterly" and the "Journal of Educational Psychology" and all…

Magnetotelluric Data, Central Yucca Flat, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Central Yucca Flat, Profile 1, as shown in figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Northern Frenchman Flat, Nevada Test Site Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.M. Williams; B.D. Rodriguez, and T. H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Frenchman Flat Profile 3, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Across Quartzite Ridge, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT soundings across Quartzite Ridge, Profiles 5, 6a, and 6b, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Southern Yucca Flat, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Southern Yucca Flat, Profile 4, as shown in Figure 1. No interpretation of the data is included here.« less

Magnetotelluric Data, Northern Yucca Flat, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Profile 2, (fig. 1), located in the northern Yucca Flat area. No interpretation of the data is included here.« less

African-American Women’s Perceptions and Experiences About Breastfeeding

PubMed Central

Obeng, Cecilia S.; Emetu, Roberta E.; Curtis, Terry J.

2015-01-01

There are health benefits to breastfeeding for both mothers and their children. The preventive health effects of breastfeeding continue into adulthood, lowering rate of various chronic illnesses. African-American women, especially of lower socioeconomic status, are less likely to breastfeed in comparison to their racial and ethnic counterparts. The purpose of this study is to explore how African-American women experience breastfeeding in the early stages of postpartum care. Two focus groups (N = 20, 10 in each group) were conducted with African-American mothers. Results revealed that participants felt that there were health benefits to breastfeeding, and organizations such as Women, Infants, and Children (WIC) provided support. However, participants stated that lack of information, negative perceptions, and unforeseen circumstances were barriers to breastfeeding. This study proposes support and interventions for this group to increase breastfeeding among this population. PMID:26734597

Experiences of Chinese International Students Learning English at South African Tertiary Institutions

ERIC Educational Resources Information Center

Ayliff, D.; Wang, G.

2006-01-01

This article aims to provide insight into the experiences of Chinese international students in some South African tertiary institutions. The study investigates their successes and failures in endeavouring to learn English and the culture shock and "learning shock" they endure when registering to study in an African country with an…

Teaching the African-American Experience in the Palmetto State. Educator Resource Guide.

ERIC Educational Resources Information Center

South Carolina State Dept. of Education, Columbia.

This resource guide for teaching the African-American experience in South Carolina's public schools is designed to serve as a supplement to the "South Carolina Social Studies Curriculum Standards." Focusing on the history and culture of Africa and African-Americans within the specific context of the state's curriculum standards and…

Introducing Python tools for magnetotellurics: MTpy

NASA Astrophysics Data System (ADS)

Krieger, L.; Peacock, J.; Inverarity, K.; Thiel, S.; Robertson, K.

2013-12-01

Within the framework of geophysical exploration techniques, the magnetotelluric method (MT) is relatively immature: It is still not as widely spread as other geophysical methods like seismology, and its processing schemes and data formats are not thoroughly standardized. As a result, the file handling and processing software within the academic community is mainly based on a loose collection of codes, which are sometimes highly adapted to the respective local specifications. Although tools for the estimation of the frequency dependent MT transfer function, as well as inversion and modelling codes, are available, the standards and software for handling MT data are generally not unified throughout the community. To overcome problems that arise from missing standards, and to simplify the general handling of MT data, we have developed the software package "MTpy", which allows the handling, processing, and imaging of magnetotelluric data sets. It is written in Python and the code is open-source. The setup of this package follows the modular approach of successful software packages like GMT or Obspy. It contains sub-packages and modules for various tasks within the standard MT data processing and handling scheme. Besides pure Python classes and functions, MTpy provides wrappers and convenience scripts to call external software, e.g. modelling and inversion codes. Even though still under development, MTpy already contains ca. 250 functions that work on raw and preprocessed data. However, as our aim is not to produce a static collection of software, we rather introduce MTpy as a flexible framework, which will be dynamically extended in the future. It then has the potential to help standardise processing procedures and at same time be a versatile supplement for existing algorithms. We introduce the concept and structure of MTpy, and we illustrate the workflow of MT data processing utilising MTpy on an example data set collected over a geothermal exploration site in South

A practical, low-noise coil system for magnetotellurics

USGS Publications Warehouse

Stanley, William D.; Tinkler, Richard D.

1983-01-01

Magnetotellurics is a geophysical technique which was developed by Cagnaird (1953) and Tikhonov (1950) and later refined by other scientists worldwide. The technique is a method of electromagnetic sounding of the Earth and is based upon the skin depth effect in conductive media. The electric and magnetic fields arising from natural sources are measured at the surface of the earth over broad frequency bands. An excellent review of the technique is provided in the paper by Vozoff (1972). The sources of the natural fields are found in two basic mechanisms. At frequencies above a few hertz, most of the energy arises from lightning in thunderstorm belts around the equatorial regions. This energy is propagated in a wave-guide formed by the earthionospheric cavity. Energy levels are higher at fundamental modes for this cavity, but sufficient energy exists over most of the audio range to be useful for sounding at these frequencies, in which case the technique is generally referred to as audio-magnetotellurics or AMT. At frequencies lower than audio, and in general below 1 Hz, the source of naturally occuring electromagnetic energy is found in ionospheric currents. Current systems flowing in the ionosphere generate EM waves which can be used in sounding of the earth. These fields generate a relatively complete spectrum of electromagnetic energy that extends from around 1 Hz to periods of one day. Figure 1 shows an amplitude spectrum characteristic of both the ionospheric and lightning sources, covering a frequency range from 0.0001 Hz to 1000 Hz. It can be seen that there is a minimum in signal levels that occurs at about 1 Hz, in the gap between the two sources, and that signal level increases with a decrease in frequency.

Reflections of Academic Experiences from Formerly Incarcerated African American Males

ERIC Educational Resources Information Center

Jeffers, Adam R.

2017-01-01

This research examines academic experiences of African American males (ages 18-25) who attended urban schools in southern California. The participants were incarcerated for at least one year prior to being housed in a pre-release program where they reflected on their academic experiences and perceptions of the school environment. The participants'…

African American Perspectives and Experiences of Domestic Violence in a Rural Community.

PubMed

Valandra; Murphy-Erby, Yvette; Higgins, Brandon M; Brown, Lucy M

2016-09-01

Relatively few studies have explored domestic violence from a multiplicity of African American perspectives, experiences, and socio-demographic backgrounds within rural African American communities. Community-based participatory action research methods were used to explore domestic violence perceptions of African Americans with heterogeneous backgrounds and experiences of violence. Ten focus groups were held throughout the community with 52 diverse women ( n = 33) and men ( n = 19) living in the northwest region of Arkansas. Demographic data were collected from 47 women ( n = 28) and men ( n = 19) participating in focus groups regarding their perceptions and experiences of domestic violence, media messages, help-seeking behaviors, and services. Data were analyzed using grounded theory methods. Three major themes emerged, including (a) a heightened awareness of race, gender, and class differences; (b) imbalanced and mixed messages from media; and (c) multi-systemic dynamics influencing abusive behavior and relationships. Results indicate that study participants' perspectives and experiences with domestic violence reflect a complex interrelated gamut of societal, community, familial, and individual dynamics. Participant recommendations related to interpersonal dynamics, media messages, and societal influences are reported with implications for practice, policy, and future research.

Unheard and Unseen: How Housing Insecure African American Adolescents Experience the Education System

ERIC Educational Resources Information Center

Ellis, Addie Lucille; Geller, Kathy D.

2016-01-01

This narrative study is based on stories told by African American adolescents experiencing homelessness. It offers insights into their lived experiences and describes the challenges faced in negotiating the urban education system. African American youth are disproportionately represented in the adolescent homeless demographic. "Unheard and…

Adaptive finite element modelling of three-dimensional magnetotelluric fields in general anisotropic media

NASA Astrophysics Data System (ADS)

Liu, Ying; Xu, Zhenhuan; Li, Yuguo

2018-04-01

We present a goal-oriented adaptive finite element (FE) modelling algorithm for 3-D magnetotelluric fields in generally anisotropic conductivity media. The model consists of a background layered structure, containing anisotropic blocks. Each block and layer might be anisotropic by assigning to them 3 × 3 conductivity tensors. The second-order partial differential equations are solved using the adaptive finite element method (FEM). The computational domain is subdivided into unstructured tetrahedral elements, which allow for complex geometries including bathymetry and dipping interfaces. The grid refinement process is guided by a global posteriori error estimator and is performed iteratively. The system of linear FE equations for electric field E is solved with a direct solver MUMPS. Then the magnetic field H can be found, in which the required derivatives are computed numerically using cubic spline interpolation. The 3-D FE algorithm has been validated by comparisons with both the 3-D finite-difference solution and 2-D FE results. Two model types are used to demonstrate the effects of anisotropy upon 3-D magnetotelluric responses: horizontal and dipping anisotropy. Finally, a 3D sea hill model is modelled to study the effect of oblique interfaces and the dipping anisotropy.

A magnetotelluric feasibility study of the Alps

NASA Astrophysics Data System (ADS)

Ritter, O.; Weckmann, U.

2016-12-01

The Alps are a famous and extensive mountain range system in central Europe. The mountains were formed as the African and Eurasian tectonic plates collided and they have been a prime target for geological and geophysical investigations since the beginning of modern geosciences. Consequently, the Alps have been investigated with active and passive seismological methods and extensive sets of potential field data exist. Hardly anything is known, however, about the deep electrical conductivity structure, as it has been notoriously difficult to acquire magnetotelluric (MT) data in the Alps. The Alps are densely populated and a lot of infrastructure for tourism has been built over the years. MT measurements, which rely on natural variations of the electromagnetic background fields, are severely hampered by this man-made noise. Here, we report on a feasibility study to acquire MT data in the Alps, where all stations are deployed outside the valleys, on high mountain ranges and alpine pastures. Overall we recorded MT data at 7 stations, along an approximately north-south profile centred on Mayrhofen in the Austrian Alps. The average station spacing was 5 kilometers. The data were processed using robust remote-reference processing and the results clearly show that MT measurements are feasible. We used Mare2DEM for 2D inversion to include a somewhat realistic topography. The 2D section indicates moderate resistivity for the top 2 - 5 km, consistent with the regional geology, which suggests (meta-) sedimentary sequences. From depths of 5 km and below resistivities exceed 5,000 Ohmm. This means we can sense very deep with MT but also, that we should be cautious with an interpretation of this short profile. The data also clearly indicate 3D effects. We therefore propose to deploy an array of stations covering the entire Alps in USArray style, e.g. with a station spacing of approximately 50 km, to derive a 3D model of the deep electrical resistivity structure of the Alps. Such a

African American Women's Sexual Objectification Experiences: A Qualitative Study

ERIC Educational Resources Information Center

Watson, Laurel B.; Robinson, Dawn; Dispenza, Franco; Nazari, Negar

2012-01-01

The purpose of our study was to investigate African American women's experiences with sexual objectification. Utilizing grounded theory methodology as well as Black feminist thought and objectification theory as the research lenses, the results of this study uncovered how racist, sexist, and classist ideologies contributed to sexual…

Resiliency in Physics: The Lived Experiences of African-American Women Who Completed Doctoral Physics Programs

ERIC Educational Resources Information Center

Burnette, Samara Fleming

2013-01-01

Currently, little is known about African-American women with doctoral degrees in physics. This study examined the lived experiences of African-American women who completed doctoral programs in physics. Due to factors of race and gender, African-American women automatically enter a double-bind in science, technology, engineering, and mathematics…

Exploring the Meaning African American PETE Teacher Candidates Ascribe to Their Aquatic Experiences

ERIC Educational Resources Information Center

Sato, Takahiro; Hodge, Samuel R.

2012-01-01

Physical Education Teacher Education (PETE) programs typically require their graduates to learn to swim proficiently. However, the research base is underdeveloped regarding the aquatic experiences of African Americans in PETE programs. The purpose of this study was to explore the meaning African American PETE teacher candidates ascribe to their…

Structures of Mid-Polish Trough in the light of regional magnetotelluric survey

NASA Astrophysics Data System (ADS)

Stefaniuk, M.; Pokorski, J.; Wojdyla, M.; Klitynski, W.

2009-04-01

Introduction The magnetotelluric survey at three long regional profiles crossing the Mid-Polish Trough in north-western part of Poland was made during 2005-2008 period. Two of the profiles pass across the Pomeranian section of the Trough and the third one cuts its Kujawy section. The task of the survey was to recognize the geological structure of the contact zone of Precambrian East European Craton and Paleozoic Platform of Western Europe. The profiles crossed major geological structures of central and north-western Poland, including the Variscan Externides and Varscian Foredeep, the Transeuropean Suture Zone and the marginal zone of the East European Craton. The main objectives of the project included evaluation of resistivity distribution and identification of structures of sub-Zechstein sedimentary and metamorphic complexes.The screening of seismic energy by high reflective Zechstein evaporates is the main problem in identifying the sub-Zechstein complexes in the Polish Lowlands area. Since evaporates do not screen the electromagnetic waves, the magnetotelluric method can be advantageously applied. The sub-Zechstein complexes and structures are commonly considered as hydrocarbon prospective. A lot of gas deposits have been discovered in Rotliegend sediments in central and Western Europe. A number offshore and onshore oil fields were found in Cambrian sandstones in the Baltic Sea area. Techniques and methodology of surveys Magnetotelluric measurements were taken with the use of MT-1 system of Electromagnetic Instruments Incorporation (EMI), Richmond, California, USA and System 2000.net based on V8 receiver of Phoenix Geophysics Ltd., Ottawa, Canada. An average spacing of sounding sites was about 4 km. The components of natural electromagnetic field were recorded over a broad range of frequencies, ranging from 0.0003 Hz to 575 Hz (MT-1) and 0,0003 HZ to 10 000,0 HZ (System 2000.net). This frequency band allowed information on the geology from a depth range of a

Stochastic Inversion of 2D Magnetotelluric Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jinsong

2010-07-01

The algorithm is developed to invert 2D magnetotelluric (MT) data based on sharp boundary parametrization using a Bayesian framework. Within the algorithm, we consider the locations and the resistivity of regions formed by the interfaces are as unknowns. We use a parallel, adaptive finite-element algorithm to forward simulate frequency-domain MT responses of 2D conductivity structure. Those unknown parameters are spatially correlated and are described by a geostatistical model. The joint posterior probability distribution function is explored by Markov Chain Monte Carlo (MCMC) sampling methods. The developed stochastic model is effective for estimating the interface locations and resistivity. Most importantly, itmore » provides details uncertainty information on each unknown parameter. Hardware requirements: PC, Supercomputer, Multi-platform, Workstation; Software requirements C and Fortan; Operation Systems/version is Linux/Unix or Windows« less

Electrical Resistivity Structure of the Valles Caldera, New Mexico, USA: Results From 3D Inversion of Modern and Legacy Magnetotelluric Data Collected by Industry and the Summer of Applied Geophysical Experience (SAGE).

NASA Astrophysics Data System (ADS)

Feucht, D. W.; Bedrosian, P.; Jiracek, G. R.; Pellerin, L.; Nettleton, C. E.

2017-12-01

The Valles caldera, in north-central New Mexico, USA, is a 20-km wide topographic depression in the Jemez Mountains volcanic complex that formed during two massive ignimbrite eruptions 1.65 and 1.26 Ma. Post-collapse volcanic activity in the caldera includes the rise of a 1 km high resurgent dome, periodic eruptions of the Valles rhyolite along ring fractures, and the presence of a geothermal reservoir beneath the western caldera with temperatures in excess of 300°C at a mere 2 km depth. We present an electrical resistivity model of the upper crust from three-dimensional (3D) inversion of broadband (100 Hz to 600 s) magnetotelluric (MT) data collected in and around the Valles caldera. The Summer of Applied Geophysical Experience (SAGE) has been acquiring geophysical data in the northern Rio Grande rift for more than three decades (1983-2017). Included in that vast dataset are over 60 broadband magnetotelluric soundings that have recently been cataloged, geo-located, and digitized for use in modern geophysical processing and modeling. The resistivity models presented here were produced by inverting a subset of SAGE MT data along with 30 broadband MT soundings acquired by the Unocal Corporation in 1983 for geothermal exploration of the caldera. We use the 3D inversion algorithm ModEM (Egbert and Kelbert, 2012) to invert full impedance tensors and tipper functions from >30 MT stations for the electrical resistivity structure beneath the caldera. Our preferred model reveals the geometry and electrical properties of (1) the conductive caldera fill, (2) the resistive crystalline basement, and (3) an enigmatic mid-crustal conductor related to magmatic activity that post-dates caldera formation.

Magnetotelluric Data, North Central Yucca Flat, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.M. Williams; B.D. Rodriguez, and T.H. Asch

2005-11-23

Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for north central Yucca Flat, Profile 7, as shown in Figure 1. No interpretation of the data is included here.« less

An Exploration of the Effects of Skin Tone on African American Life Experiences.

ERIC Educational Resources Information Center

Breland, Alfiee M.; Collins, Wanda; Damico, Karen Lowenstein; Steward, Robbie; King, Jennifer

This study surveys African Americans to assess perceptions of and life experiences with the issue of skin tone. Thirty-seven African American adults agreed to complete a survey packet and participate in a semi-structured focus group discussion. Participants completed the Rosenberg Self-Esteem Scale, the Multigroup Ethnic Identity Measure, the Skin…

Academic attainment and the high school science experiences among high-achieving African American males

NASA Astrophysics Data System (ADS)

Trice, Rodney Nathaniel

This study examines the educational experiences of high achieving African American males. More specifically, it analyzes the influences on their successful navigation through high school science. Through a series of interviews, observations, questionnaires, science portfolios, and review of existing data the researcher attempted to obtain a deeper understanding of high achieving African American males and their limitations to academic attainment and high school science experiences. The investigation is limited to ten high achieving African American male science students at Woodcrest High School. Woodcrest is situated at the cross section of a suburban and rural community located in the southeastern section of the United States. Although this investigation involves African American males, all of whom are successful in school, its findings should not be generalized to this nor any other group of students. The research question that guided this study is: What are the limitations to academic attainment and the high school science experiences of high achieving African American males? The student participants expose how suspension and expulsion, special education placement, academic tracking, science instruction, and teacher expectation influence academic achievement. The role parents play, student self-concept, peer relationships, and student learning styles are also analyzed. The anthology of data rendered three overarching themes: (1) unequal access to education, (2) maintenance of unfair educational structures, and (3) authentic characterizations of African American males. Often the policies and practices set in place by school officials aid in creating hurdles to academic achievement. These policies and practices are often formed without meaningful consideration of the unintended consequences that may affect different student populations, particularly the most vulnerable. The findings from this study expose that high achieving African American males face major

The Perceived Undergraduate Classroom Experiences of African American Women in Science, Technology, Engineering, and Mathematics (STEM)

ERIC Educational Resources Information Center

Holmes, Kimberly Monique

2013-01-01

The purpose of this dissertation study was to explore African-American women's perceptions of undergraduate STEM classroom experiences, and the ways in which those experiences have supported or hindered their persistence in physics majors. The major research question guiding this study was: How do African-American women perceive the climate and…

Joint two dimensional inversion of gravity and magnetotelluric data using correspondence maps

NASA Astrophysics Data System (ADS)

Carrillo Lopez, J.; Gallardo, L. A.

2016-12-01

Inverse problems in Earth sciences are inherently non-unique. To improve models and reduce the number of solutions we need to provide extra information. In geological context, this information could be a priori information, for example, geological information, well log data, smoothness, or actually, information of measures of different kind of data. Joint inversion provides an approach to improve the solution and reduce the errors due to suppositions of each method. To do that, we need a link between two or more models. Some approaches have been explored successfully in recent years. For example, Gallardo and Meju (2003), Gallardo and Meju (2004, 2011), and Gallardo et. al. (2012) used the directions of properties to measure the similarity between models minimizing their cross gradients. In this work, we proposed a joint iterative inversion method that use spatial distribution of properties as a link. Correspondence maps could be better characterizing specific Earth systems due they consider the relation between properties. We implemented a code in Fortran to do a two dimensional inversion of magnetotelluric and gravity data, which are two of the standard methods in geophysical exploration. Synthetic tests show the advantages of joint inversion using correspondence maps against separate inversion. Finally, we applied this technique to magnetotelluric and gravity data in the geothermal zone located in Cerro Prieto, México.

Water exploration using Magnetotelluric and gravity data analysis; Wadi Nisah, Riyadh, Saudi Arabia

NASA Astrophysics Data System (ADS)

Aboud, Essam; Saud, Ramzi; Asch, Theodore; Aldamegh, Khaled; Mogren, Saad

2014-12-01

Saudi Arabia is a desert country with no permanent rivers or lakes and very little rainfall. Ground water aquifers are the major source of water in Saudi Arabia. In the Riyadh region, several Wadies including Wadi Nisah store about 14 × 106 m3 of water, which is extracted for local irrigation purposes. In such areas, the water wells are as shallow as 200-300 m in depth. The importance of Wadi Nisah is because the subsurface water aquifers that are present there could support the region for many years as a water resource. Accordingly, in this study, we performed a Magnetotelluric survey using a portable broadband sounding system (MT24/LF) to evaluate the ground water aquifer at great depths. We collected 10 broadband Magnetotelluric sounding stations (1 station/day) with an interval of about 2-3 km reaching a profile length of about 25-30 km along Wadi Nisah. Additionally, we used available gravity data to image the subsurface structure containing the aquifer. MT results indicated a low resistivity layer, associated with alluvium deposits, which was defined at a depth of about 1-2 km and extended horizontally about 15 km. Gravity data analysis was used to model this resistivity layer indicating a basement surface at 3-4 km depth.

African American Women Coping with the Lived Experiences of Limited Mental Healthcare Access in Rural North Carolina

ERIC Educational Resources Information Center

Lesane, Everick S.

2013-01-01

This study examined the impact of lived experiences among African American women with limited mental healthcare access in rural North Carolina. The research examined how those lived experiences-due to limited transportation, low socioeconomic status, and limited healthcare access-further exacerbate emotional challenges among African American…

Early Academic Experiences of Recently Incarcerated African American Males

ERIC Educational Resources Information Center

Jeffers, Adam R.

2010-01-01

This project examines the early educational experiences of 6 young African American males (ages 18-25) who attended urban schools in San Diego, California. All 6 men were incarcerated for at least 1-year before participating in a pre-release program. The participants were part of a pre-release program in San Diego, California, which was selected…

The experiences of African American graduate students: A cultural transition

NASA Astrophysics Data System (ADS)

Joseph, Joretta

Historically Black Colleges and Universities (HBCU) have long been an intellectual resource for the African American community. HBCUs have provided and continue to provide an educational pathway for many Black students, particularly women who seek graduate and advanced degrees. However, despite the overwhelmingly positive presence of HBCU in the African American community, the academic training of students who graduate from HBCUs may be perceived as insufficient by predominantly White graduate institutions (PWIs). As a result, African American students who are not well integrated into their respective departmental communities and cultures at PW/is are likely to leave graduate school. Thus the continuing loss of talented people, potential research, role models for society, and the next generation of African American students in the fields of math, engineering, and the sciences (STEM) create a segregated and limited university environment. Studies in the field that attempt to provide insight in to experiences of underrepresented students are ultimately beneficial. However, often such studies do not address the process of adapting to the culture of a predominantly white institution (PWI), particularly within white and male dominated fields such as mathematics and the sciences. Research has also indicated that the first two years at a predominantly white graduate institution is the crucial transitional period for students of color, and it is this transitional moment in time that is the focus of this study. I consider how students make the transition from HBCU to majority institutions, and what impact this transition has on their persistence and commitment to their discipline. The limited amount of research that does address the experiences of minority doctoral students in math and science is usually coupled with the experiences of women. However, race and gender are not linear or additive. It cannot be assumed that the same factors that effect the under representation

XML Storage for Magnetotelluric Transfer Functions: Towards a Comprehensive Online Reference Database

NASA Astrophysics Data System (ADS)

Kelbert, A.; Blum, C.

2015-12-01

Magnetotelluric Transfer Functions (MT TFs) represent most of the information about Earth electrical conductivity found in the raw electromagnetic data, providing inputs for further inversion and interpretation. To be useful for scientific interpretation, they must also contain carefully recorded metadata. Making these data available in a discoverable and citable fashion would provide the most benefit to the scientific community, but such a development requires that the metadata is not only present in the file but is also searchable. The most commonly used MT TF format to date, the historical Society of Exploration Geophysicists Electromagnetic Data Interchange Standard 1987 (EDI), no longer supports some of the needs of modern magnetotellurics, most notably accurate error bars recording. Moreover, the inherent heterogeneity of EDI's and other historic MT TF formats has mostly kept the community away from healthy data sharing practices. Recently, the MT team at Oregon State University in collaboration with IRIS Data Management Center developed a new, XML-based format for MT transfer functions, and an online system for long-term storage, discovery and sharing of MT TF data worldwide (IRIS SPUD; www.iris.edu/spud/emtf). The system provides a query page where all of the MT transfer functions collected within the USArray MT experiment and other field campaigns can be searched for and downloaded; an automatic on-the-fly conversion to the historic EDI format is also included. To facilitate conversion to the new, more comprehensive and sustainable, XML format for MT TFs, and to streamline inclusion of historic data into the online database, we developed a set of open source format conversion tools, which can be used for rotation of MT TFs as well as a general XML <-> EDI converter (https://seiscode.iris.washington.edu/projects/emtf-fcu). Here, we report on the newly established collaboration between the USGS Geomagnetism Program and the Oregon State University to gather

Caregiver Experiences of Discrimination and African American Adolescents' Psychological Health over Time

ERIC Educational Resources Information Center

Ford, Kahlil R.; Hurd, Noelle M.; Jagers, Robert J.; Sellers, Robert M.

2013-01-01

The present study examined the effect of caregivers' experiences of racial discrimination on their adolescent children's psychological functioning among a sample of 264 African American dyads. Potential relations between caregiver discrimination experiences and a number of indicators of adolescents' (aged 12-17) psychological functioning over time…

Crustal and lithospheric imaging of the Atlas Mountains of Morocco inferred from magnetotelluric data

NASA Astrophysics Data System (ADS)

Kiyan, D.; Jones, A. G.; Fullea, J.; Hogg, C.; Ledo, J.; Sinischalchi, A.; Campanya, J.; Picasso Phase II Team

2010-12-01

The Atlas System of Morocco is an intra-continental mountain belt extending for more than 2,000 km along the NW African plate with a predominant NE-SW trend. The System comprises three main branches: the High Atlas, the Middle Atlas, and the Anti Atlas. We present the results of a very recent multi-institutional magnetotelluric (MT) experiment across the Atlas Mountains region that started in September, 2009 and ended in February, 2010, comprising acquisition of broadband and long-period MT data. The experiment consisted of two profiles: (1) a N-S oriented profile crossing the Middle Atlas through the Central High Atlas to the east and (2) a NE-SW profile crossing the western High Atlas towards the Anti Atlas to the west. The MT measurements are part of the PICASSO (Program to Investigate Convective Alboran Sea System Overturn) and the concomitant TopoMed (Plate re-organization in the western Mediterranean: Lithospheric causes and topographic consequences - an ESF EUROCORES TOPO-EUROPE project) projects, to develop a better understanding of the internal structure and evolution of the crust and lithosphere of the Atlas Mountains. The MT data have been processed with robust remote reference methods and submitted to comprehensive strike and dimensionality analysis. Two clearly depth-differentiated strike directions are apparent for crustal (5-35 km) and lithospheric (50-150 km) depth ranges. These two orientations are roughly consistent with the NW-SE Africa-Eurasia convergence acting since the late Cretaceous, and the NNE-SSW Middle Atlas, where Miocene to recent Alkaline volcanism is present. Two-dimensional (2-D) smooth electrical resistivity models were computed independently for both 50 degrees and 20 degrees E of N strike directions. At the crustal scale, our preliminary results reveal a middle to lower-crustal conductive layer stretching from the Middle Atlas southward towards the High Moulouya basin. The most resistive (and therefore potentially thickest

Crustal Scale Magnetotelluric Imaging of the Central Atlas in Moocco

NASA Astrophysics Data System (ADS)

Ledo, J.; Jones, A. G.; Sinischalchi, A.; Rouais, M.; Campanyà, J.; Kiyan, D.; Moretti, P.; Piña, P.; Hogg, C.; Romano, G.; Picasso Team

2010-12-01

The Central Atlas of Morocco is an intracontinental fold-thrust belt with an ENE-WSW main strike that extends about 2000 km and 100 km wide, located in the foreland of the Mediterranean Alpine belt. The structure of the Atlas resulted from the tectonic inversion of a Mesozoic extensional basin, due to compression related to convergence between Africa and Europe occurred from cenozoic to present times. Previous MT data models based on stitched 1D inversion or using only the phases and the induction vector data following and trial and error approach (Schwarz et al., 1992), therefore the overall geoelectrical structure is partly unresolved. In this paper we will expose and discuss the results of new magnetotelluric data acquired along a profile crossing the Atlas that allows imaging its electrical crustal structure.In the lower crust two conductive units appear. One below the Moulouya plains that coincides with a minimum of the Bouguer anomaly, less earthquakes than the adjacent Middle and High Atlas and a low velocity anomaly at lower crustal levels. Moreover, the Moulouya plain and the Middle Atlas to the north are host of the largest Neogene-Quaternary intraplate alkaline volcanic field in Morocco. This feature has been associated either to a Canary mantle plume flow beneath Africa or to the interplay between reactivation of inherited geological structures and the thermal erosion of the metasomatized lithosphere. In any case, all the authors agree that are originated by low degree partial melting of sublithospheric mantle sources. Another low resistivity anomaly appears at lower crustal depths below the Anti-Atlas, that could be either a remnant of tectonic processes in the pre-mesozoic or a more recent overprint of the lower crust due to mantle processes. Two main events during the Pan African orogeny may be the cause of this anomaly, a relic of a subduction process or a deep mineralization associated to magmatism. The Anti-Atlas consists of of a Precambrian

African American eighth-grade female students' perceptions and experiences as learners of science literacy

NASA Astrophysics Data System (ADS)

Crim, Sharan R.

The National Assessment of Educational Progress (2000) reports an achievement gap between male and female students and majority and minority students in science literacy. Rutherford and Algren (2000) describe a scientifically literate person as one who is aware that science, mathematics, and technology are interdependent human enterprises with strengths and limitations; understands key concepts and principles of science; is familiar with the natural world and recognizes both its diversity and unity; and uses scientific knowledge and scientific ways of thinking for individual and social purposes. The purpose of this qualitative case study research was to investigate African American eighth grade female students' perceptions and experiences as learners of science literacy. A social learning theory (Bandura, 1986) and constructivist theory (Vygotsky, 1977) served as a guide for the researcher. Two questions were explored: (1) What are African American eighth grade female students' perceptions and experiences as learners of science literacy? (2) In what ways do the perceptions and experiences of African American eighth grade female students influence their learning of science literacy? Purposeful sampling (Merriam, 1998) was used with four African American eighth grade female students selected as participants for the study. Data collection and analysis occurred between February and August in a single year. Data sources included an open-ended questionnaire, two in-depth interviews with each participant (Seidman, 1991); classroom observations, participant reflective journals, student artifacts, and a researcher's log. Data were analyzed through the constant comparative method (Glaser & Strauss, 1967), and richly descriptive participant portraits and qualitative case studies (Merriam, 1998) were used to report the findings. Three themes emerged from the study that positively affected the perceptions and experiences of African American eighth grade female students as

The Experience of African Students Studying Nursing in the United States in Relation to Their Use of Critical Thinking

ERIC Educational Resources Information Center

Tyson, Donald Lee

2012-01-01

This qualitative study explores the critical thinking experiences of African nursing students enrolled in several universities in the U.S. Using a semi-structured interview approach, twelve African students discussed their experiences using and learning a western critical thinking approach, as well as described their educational experiences in…

Help-Seeking Experiences and Attitudes among African American, Asian American, and European American College Students

ERIC Educational Resources Information Center

Masuda, Akihiko; Anderson, Page L.; Twohig, Michael P.; Feinstein, Amanda B.; Chou, Ying-Yi; Wendell, Johanna W.; Stormo, Analia R.

2009-01-01

The study examined African American, Asian American, and European American college students' previous direct and indirect experiences of seeking professional psychological services and related attitudes. Survey data were collected from 254 European American, 182 African American and 82 Asian American college students. Results revealed that fewer…

Two-dimensional magnetotelluric model of deep resistivity structure in the Bodie-Aurora district of California

USGS Publications Warehouse

Sampson, Jay A.

2006-01-01

Introduction: Magnetotelluric data were acquired during October 2001 by the U.S. Geological Survey (USGS) as part of a study to examine the structural nature of basins in the transition zone between the Sierra Nevada Mountains of California and the Basin and Range province of Nevada. Magnetotelluric (MT) geophysical studies assist the mapping of geologic structure and the inference of lithologic packages that are concealed beneath the Earth's surface. The Basin and Range province has a complicated geologic history, which includes extension and compression of the Earth's crust to form the basins and ranges that blanket much of Nevada. The basins and ranges in the vicinity of this study trend northeastward and are bounded by steeply dipping strike slip faults. Interestingly, deep east-west magnetic trends occur in the aeromagnetic data of this study area indicating that the northeast-trending basins and ranges represent only thin-skinned deformation at the surface with an underlying east-west structure. To investigate this issue, MT data were acquired at seven stations in eastern California, 20 km east of Mono Lake. The purpose of this report is to present a two-dimensional apparent resistivity model of the MT data acquired for this study.

Masculinities fathering and health: the experiences of African-Caribbean and white working class fathers.

PubMed

Williams, Robert Alan

2007-01-01

There is a developing body of research that investigates the links between masculinities and men's health experiences, but the links between masculinities and the health of fathers has been a neglected focus for research in the UK. This paper presents some of the findings drawn from a parent study which investigated African-Caribbean and white working class fathers' experiences of fathering, health and social connectedness. Data are drawn from interviews with 13 men (6 African-Caribbean and 7 White working class) living in a city in the West Midlands area of the UK. In this paper, I analyse and discuss African-Caribbean and white working class fathers' stories about the meaning of health, the influences upon their health, and their health practices. It was found that for the African-Caribbean fathers specifically, anticipated or perceived racist prejudice, abuse or discrimination influenced their health experiences. However, the meaning of health for both ethnic groups of fathers was as functional capacity, that is health was an asset that allowed fathers to meet the obligations of paid work and fathering. These obligations were also associated with a restricted sense of personal agency for the men interviewed, and the associated constraints were linked to transgressive consumption of alcohol, food and tobacco. In addition, fathers were also involved in solitary ways of dealing with their vulnerability, vulnerability that was associated with fathers' health concerns, and other difficult life experiences. Fathers' solitary experiences of vulnerability were also mediated by hegemonic forms of masculinity. Nevertheless, the experience of fathering within the lifecourse influenced men's health experiences: reflexivity and challenges to both transgressive consumption and solitary experiences were linked to fathers' perceived obligations to children. The significance of gender, ethnicity and social class for theory and future research with working class fathers and boys

The Lived Experience of the Adult African American Female Who Has Lived in Multiple Foster Care Placements

ERIC Educational Resources Information Center

Johnson, Avonda C.

2012-01-01

The purpose of the study was to examine and describe the lived experiences of the adult African American woman who had lived in multiple foster care placements. Eleven adult African American women ages 22-25 participated in semi-structured, face-to-face interviews to tell their stories and provide data of the memories of the experience. The…

Parental experiences of racial discrimination and youth racial socialization in two-parent African American families.

PubMed

McNeil Smith, Shardé; Reynolds, Jamila E; Fincham, Frank D; Beach, Steven R H

2016-04-01

Parents experiencing racial discrimination are likely to transmit racial socialization messages to their children to protect them from future injustices. This study was conducted to better understand the role of parents' racial discrimination in their racial socialization practices for 2-parent African American families. Using a sample from the Promoting Strong African American Families (N = 322 couples) program, we examined the effects of experienced discrimination on one's own and one's partner's racial socialization practices with male (n = 154) and female (n = 168) offspring. Multiple-group actor-partner interdependence models showed that racial discrimination was associated with racial socialization practices. In addition, maternal experiences of discrimination had stronger relations to socialization messages relayed to daughters and greater paternal experiences of discrimination had stronger relations to socialization messages given to sons. This study demonstrates variability in how male and female children in African American families are socialized as a result of their parents' experiences with racial discrimination. (c) 2016 APA, all rights reserved).

The Criminal Justice Experience of African American Cocaine Users in Arkansas.

PubMed

Zaller, Nickolas; Cheney, Ann M; Curran, Geoffrey M; Booth, Brenda M; Borders, Tyrone F

2016-10-14

African Americans are incarcerated at rates much higher than other racial and ethnic groups in the United States. We sought to qualitatively explore the relationships between ongoing involvement in the criminal justice system and continued drug use in a population of urban and rural African American cocaine users in a southern state. Semi-structured qualitative interviews were conducted among African American cocaine users in Arkansas between 2010 and 2012. Participants resided in both rural (two counties located in the eastern Arkansas Mississippi delta region) and urban (the county including the capital city of Little Rock) areas. Numerous important themes emerged from participants' narratives, including chronic involvement with the criminal justice system (being a "career criminal"), continued access to drugs while incarcerated, relapse, and reincarceration and lack of access to effective drug treatment. Conclusion/Importance: The themes which emerged from our data speak to the collective experience that many substance using populations in the United States face in dealing with the criminal justice system. Our findings highlight the need to better, more holistic ways of engaging African American substance users in community based substance use treatment and supportive services.

The Criminal Justice Experience of African American Cocaine Users in Arkansas

PubMed Central

Zaller, Nickolas; Cheney, Ann M.; Curran, Geoffrey M.; Booth, Brenda M.; Borders, Tyrone F.

2018-01-01

Background African Americans are incarcerated at rates much higher than other racial and ethnic groups in the United States. Objectives We sought to qualitatively explore the relationships between ongoing involvement in the criminal justice system and continued drug use in a population of urban and rural African American cocaine users in a southern state. Methods Semi-structured qualitative interviews were conducted among African American cocaine users in Arkansas between 2010 and 2012. Participants resided in both rural (two counties located in the eastern Arkansas Mississippi delta region) and urban (the county including the capital city of Little Rock) areas. Results Numerous important themes emerged from participants’ narratives, including chronic involvement with the criminal justice system (being a “career criminal”), continued access to drugs while incarcerated, relapse, and reincarceration and lack of access to effective drug treatment. Conclusion/Importance The themes which emerged from our data speak to the collective experience that many substance using populations in the United States face in dealing with the criminal justice system. Our findings highlight the need to better, more holistic ways of engaging African American substance users in community based substance use treatment and supportive services. PMID:27486889

Magnetotelluric Data, Mid Valley, Nevada Test Site, Nevada

USGS Publications Warehouse

Williams, Jackie M.; Wallin, Erin L.; Rodriguez, Brian D.; Lindsey, Charles R.; Sampson, Jay A.

2007-01-01

Introduction The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data at the Nevada Test Site in and near Yucca Flat (YF) to help define the character, thickness, and lateral extent of the pre-Tertiary confining units. We collected 51 magnetotelluric (MT) and audio-magnetotelluric (AMT), stations for that research. In early 2005 we extended that research with 26 additional MT data stations, located on and near Rainier Mesa and Shoshone Mountain (RM-SM). The new stations extended the area of the hydrogeologic study previously conducted in Yucca Flat. This work was done to help refine what is known about the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal was to define the upper clastic confining unit (UCCU). The UCCU is comprised of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale. The UCCU underlies the Yucca Flat area and extends westward towards Shoshone Mountain, southward to Buckboard Mesa, and northward to Rainier Mesa. Late in 2005 we collected another 14 MT stations in Mid Valley and in northern Yucca Flat basin. That work was done to better determine the extent and thickness of the UCCU near

An Amphibious Magnetotelluric Investigation of the Cascadian Seismogenic and ETS zones.

NASA Astrophysics Data System (ADS)

Parris, B. A.; Livelybrooks, D.; Bedrosian, P.; Egbert, G. D.; Key, K.; Schultz, A.; Cook, A.; Kant, M.; Wogan, N.; Zeryck, A.

2015-12-01

The amphibious Magnetotelluric Observations of Cascadia using a Huge Array (MOCHA) experiment seeks to address unresolved questions about the seismogenic locked zone and down-dip transition zone where episodic tremor and slip (ETS) originates. The presence of free fluids is thought to be one of the primary controls on ETS behavior within the Cascadia margin. Since the bulk electrical conductivity in the crust and mantle can be greatly increased by fluids, magnetotelluric(MT) observations can offer unique insights on the fluid distribution and its relation to observed ETS behavior. Here we present preliminary results from the 146 MT stations collected for the MOCHA project. MOCHA is unique in that it is the first amphibious array of MT stations occupied to provide for 3-D interpretation of conductivity structure of a subduction zone. The MOCHA data set comprises 75 onshore stations and 71 offshore stations, accumulated over a two-year period, and located on an approximate 25km grid, spanning from the trench to the Eastern Willamette Valley, and from central Oregon into middle Washington. We present the results of a series of east-west (cross-strike) oriented, two-dimensional inversions created using the MARE2DEM software that provide an initial picture of the conductivity structure of the locked and ETS zones and its along strike variations. Our models can be used to identify correlations between ETS occurrence rates and inferred fluid concentrations. Our modeling explores the impact of various parameterizations on 2-D inversion results, including inclusion of a smoothness penalty reduction along the inferred slab interface. This series of 2-D inversions can then be used collectively to help make and guide an a priori 3-D inversion. In addition we will present a preliminary 3-D inversion of the onshore stations created using the ModEM software. We are currently working on modifying ModEM to support inversion of offshore data. The more computationally intensive 3-D

The Lived Experiences of African American Women with Breast Cancer: Implications for Counselors

ERIC Educational Resources Information Center

Clay, LaTasha K.

2013-01-01

Qualitative phenomenological methodology was used to explore the lived experiences of African American women diagnosed with breast cancer. Phenomenology focuses on the meaning of the lived experiences of individuals experiencing a concept, structure, or phenomenon (Creswell, 2007). The purpose of phenomenological research is to identify phenomena…

Expecting the Unexpected: a Comparative Study of African-American Women's Experiences in Science during the High School Years

NASA Astrophysics Data System (ADS)

Hanson, Sandra L.; Johnson, Elizabeth Palmer

Data from the National Educational Longitudinal Study (NELS) for the years 1988 to 1992 are used to explore the science experiences of young African-American women during the high school years. The comparison groups we use in trying to understand these experiences involve White women (for a race contrast) and African-American men (for a gender contrast). Within the context of a critical feminist perspective, it is argued that gender is constructed in a different way in White and African-American communities. Instead of expecting a disadvantage for young African-American women because of their gender and minority statuses, it is suggested that unique gender ideologies and work-family arrangements in the African-American community give these young women the resources and agency that allow them to compete with their White female counterparts and their African-American male counterparts in the science domain. Results from our analyses of the NELS data confirm these expectations. We find that on a majority of science measures, African-American women do as well as - and sometimes better than - White women and African-American men. For example, there are no differences between African-American women and men on attitudes toward science. And when compared with White women, African-American women tend to have more positive attitudes. When disadvantages appear for these young African-American women, they are more likely to be race effects then gender effects. The minimal gender effects in the science experiences of young African-Americans is in contrast to the more frequent male advantage in the White sample. A careful examination of family and individual resources shows that African-American families compensate for disadvantages on some resources (e.g., family socioeconomic status) by providing young women with an excess of other resources (e.g., unique gender ideologies, work expectations, and maternal expectations and involvement). And, unlike White parents, they sometimes

Two-dimensional joint inversion of Magnetotelluric and local earthquake data: Discussion on the contribution to the solution of deep subsurface structures

NASA Astrophysics Data System (ADS)

Demirci, İsmail; Dikmen, Ünal; Candansayar, M. Emin

2018-02-01

Joint inversion of data sets collected by using several geophysical exploration methods has gained importance and associated algorithms have been developed. To explore the deep subsurface structures, Magnetotelluric and local earthquake tomography algorithms are generally used individually. Due to the usage of natural resources in both methods, it is not possible to increase data quality and resolution of model parameters. For this reason, the solution of the deep structures with the individual usage of the methods cannot be fully attained. In this paper, we firstly focused on the effects of both Magnetotelluric and local earthquake data sets on the solution of deep structures and discussed the results on the basis of the resolving power of the methods. The presence of deep-focus seismic sources increase the resolution of deep structures. Moreover, conductivity distribution of relatively shallow structures can be solved with high resolution by using MT algorithm. Therefore, we developed a new joint inversion algorithm based on the cross gradient function in order to jointly invert Magnetotelluric and local earthquake data sets. In the study, we added a new regularization parameter into the second term of the parameter correction vector of Gallardo and Meju (2003). The new regularization parameter is enhancing the stability of the algorithm and controls the contribution of the cross gradient term in the solution. The results show that even in cases where resistivity and velocity boundaries are different, both methods influence each other positively. In addition, the region of common structural boundaries of the models are clearly mapped compared with original models. Furthermore, deep structures are identified satisfactorily even with using the minimum number of seismic sources. In this paper, in order to understand the future studies, we discussed joint inversion of Magnetotelluric and local earthquake data sets only in two-dimensional space. In the light of these

African American Students in Counselor Education Programs: Perceptions of Their Experiences

ERIC Educational Resources Information Center

Henfield, Malik S.; Owens, Delila; Witherspoon, Sheila

2011-01-01

The authors explored 11 African American doctoral students' perceptions of their experiences in counselor education programs, and their findings are presented. Using a phenomenological methodological framework, the authors investigated the various systems of support that students use as they navigate their respective programs. Human agency was the…

Race-ing through the School Day: African American Educators' Experiences with Race and Racism in Schools

ERIC Educational Resources Information Center

Jay, Michelle

2009-01-01

This article examines the ways African American educators experience themselves as raced individuals in their school settings and explores their perceptions of racial discrimination, subordination, and isolation. For this study, five African American educators participated in in-depth phenomenological interviews. Qualitative data analysis of their…

Understanding the experiences and perceptions of African American female STEM majors at a single-sex HBCU

NASA Astrophysics Data System (ADS)

Wilson, Rahshida S.

This study uses qualitative methods to explore and understand the experiences of African American female STEM majors at a single-sex historically Black university (HBCU). The study focuses on the perspectives of Black women and how they perceive the strategies and practices utilized at a single-sex HBCU that aid in fostering the successful development of Black women in STEM fields. Although limited to one institution, the findings shed light on the ways in which African American women experience the single-sex HBCU, and how the institution aids in their persistence in STEM majors. This study also discusses how such strategies and practices at a single-sex HBCU aid in mitigating the challenges and barriers that limit the attainment of African American women in STEM fields, and provides an opportunity for them to develop strong identities in STEM. Drawing on the findings, the paper concludes with recommendations for improving implementation of strategies revealed in historically Black colleges/universities and predominantly White colleges/ universities (PWIs). Recommendations for future research suggest that the experiences of African American women in single-sex and co-educational historically Black and predominantly White institutions could be further explored.

Diversifying the secondary school curriculum: The African experience

NASA Astrophysics Data System (ADS)

Sifuna, Daniel N.

1992-01-01

The paper discusses some African experiences in the diversification of secondary education, which is taken to mean curriculum change in a practical or vocational direction. This approach is intended to provide a wider set of future career options than is offered in the more uniform academic curriculum. The diversification policy has generally been seen as a solution to a number of economic and social problems facing the independent African countries, notably the increasing youth unemployment and the escalating costs of formal education. Studies which have so far been carried out have, however, revealed that diversification programmes have not met the intended objectives, although there is sustained interest in vocationalising formal education. Problems which commonly face these programmes include high unit costs, an absence of clarity in aims and objectives, a shortage of qualified teachers and the low status of vocational subjects as viewed by the students and the community. For future development, it is suggested that diversification programmes be reorganised to relate to more realistic goals through wider community participation and through the work-orientation of post-school training programmes.

It Just Couldn't Have Been Our School: A Phenomenological Study of the Schooling Experiences of African American Male Inmates.

ERIC Educational Resources Information Center

Terrell, Shandra R.

The school experiences of African American male inmates are explored. Nine African American male inmates, ranging in age from 21 to 55, were interviewed regarding their schooling experiences. Interviews were recorded and transcribed to create a text, and themes were uncovered. Themes that describe their schooling experiences were identified. Four…

Higher Education: A Qualitative Inquiry into the Educational Experiences of Seven African Women.

ERIC Educational Resources Information Center

Otieno, Tabitha N.

This study was a qualitative inquiry that focused on the educational experiences of seven African women students' attempt to pursue higher education in their home countries. It identified the problems they encountered, and how they overcame them, and explored their educational experiences in the United States. Data came from systematic interviews…

West Flank Coso, CA FORGE Magnetotelluric Inversion

DOE Data Explorer

Doug Blankenship

2016-05-16

The Coso Magnetotelluric (MT) dataset of which the West Flank FORGE MT data is a subset, was collected by Schlumberger / WesternGeco and initially processed by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy. The 2011 data was based on 99 soundings that were centered on the West Flank geothermal prospect. The new soundings along with previous data from 2003 and 2006 were incorporated into a 3D inversion. Full impedance tensor data were inverted in the 1-3000 Hz range. The modelling report notes several noise sources, specifically the DC powerline that is 20,000 feet west of the survey area, and may have affected data in the 0.02 to 10 Hz range. Model cell dimensions of 450 x 450 x 65 feet were used to avoid computational instability in the 3D model. The fit between calculated and observed MT values for the final model run had an RMS value of 1.807. The included figure from the WesternGeco report shows the sounding locations from the 2011, 2006 and 2003 surveys.

Three-dimensional inversion for Network-Magnetotelluric data

NASA Astrophysics Data System (ADS)

Siripunvaraporn, W.; Uyeshima, M.; Egbert, G.

2004-09-01

Three-dimensional inversion of Network-Magnetotelluric (MT) data has been implemented. The program is based on a conventional 3-D MT inversion code (Siripunvaraporn et al., 2004), which is a data space variant of the OCCAM approach. In addition to modifications required for computing Network-MT responses and sensitivities, the program makes use of Massage Passing Interface (MPI) software, with allowing computations for each period to be run on separate CPU nodes. Here, we consider inversion of synthetic data generated from simple models consisting of a 1 W-m conductive block buried at varying depths in a 100 W-m background. We focus in particular on inversion of long period (320-40,960 seconds) data, because Network-MT data usually have high coherency in these period ranges. Even with only long period data the inversion recovers shallow and deep structures, as long as these are large enough to affect the data significantly. However, resolution of the inversion depends greatly on the geometry of the dipole network, the range of periods used, and the horizontal size of the conductive anomaly.

African American Teacher Candidates' Experiences in Teaching Secondary Physical Education

ERIC Educational Resources Information Center

Sato, Takahiro; Hodge, Samuel Russell

2017-01-01

The purpose of this study was to describe and explain the teaching experiences of African American physical education teacher candidates in secondary physical education programs at urban schools. The research design was explanatory multiple-case study situated in positioning theory (Harré & van Langenhove, 1999). The participants were seven…

African American Women Aspiring to the Superintendency: Lived Experiences and Barriers

ERIC Educational Resources Information Center

Angel, Roma B.; Killacky, Jim; Johnson, Patricia R.

2013-01-01

Focused on the absence of a viable population of African American women in the superintendency, this study addressed barriers described by 10 credentialed, district-level Southern women who hold advanced education degrees coupled with years of leadership experience. This phenomenological study used interview methodology to uncover the lived…

Sub-Saharan African Students and Their Experiences in American Higher Education

ERIC Educational Resources Information Center

Osikomaiya, Olujide

2014-01-01

The purpose of this research project is to study the experiences of Sub-Saharan African students, who have earned professional degrees from American institutions and are currently living in the United States. Acculturative stressors have been identified by researchers as predictors of loneliness, depression, homesickness, and poor mental health…

Personal, Professional, and Sociocultural Experiences of African American Female School Leaders

ERIC Educational Resources Information Center

Robinson, Armentress D.

2014-01-01

The purpose of this phenomenological study was to explore and gain an in-depth understanding of the personal, professional, and sociocultural experiences of ten African American female school leaders serving as assistant principals, principals, and central office administrators in four suburban school districts in the southeast region of the…

The influences and experiences of African American undergraduate science majors at predominately White universities

NASA Astrophysics Data System (ADS)

Blockus, Linda Helen

The purpose of this study is to describe and explore some of the social and academic experiences of successful African American undergraduate science majors at predominately White universities with the expectation of conceptualizing emerging patterns for future study. The study surveyed 80 upperclass African Americans at 11 public research universities about their perceptions of the influences that affect their educational experiences and career interests in science. The mailed survey included the Persistence/ voluntary Dropout Decision Scale, the Cultural Congruity Scale and the University Environment Scale. A variety of potential influences were considered including family background, career goals, psychosocial development, academic and social connections with the university, faculty relationships, environmental fit, retention factors, validation, participation in mentored research projects and other experiences. The students' sources of influences, opportunities for connection, and cultural values were considered in the context of a research university environment and investigated for emerging themes and direction for future research. Results indicate that performance in coursework appears to be the most salient factor in African American students' experience as science majors. The mean college gpa was 3.01 for students in this study. Challenging content, time demands, study habits and concern with poor grades all serve to discourage students; however, for most of the students in this study, it has not dissuaded them from their educational and career plans. Positive course performance provided encouragement. Science faculty provide less influence than family members, and more students find faculty members discouraging than supportive. Measures of faculty relations were not associated with academic success. No evidence was provided to confirm the disadvantages of being female in a scientific discipline. Students were concerned with lack of minority role models

Schooling Experiences and Perceptions of Resettled Sub-Saharan African Refugee Middle School Students in a Southwest U.S. State

ERIC Educational Resources Information Center

Sallu, Adama

2012-01-01

This study examined the schooling experiences and perceptions of resettled sub-Saharan African middle school refugee students in a metropolitan area of the United States Southwest. The research questions underpinning this study included: What are the schooling experiences and perceptions of resettled sub-Saharan African middle school refugee…

High Resolution Magnetotelluric Imaging of the Nisyros Caldera and Geothermal Resource (Greece)

NASA Astrophysics Data System (ADS)

Tzanis, Andreas; Sakkas, Vassilis; Lagios, Evangelos

2017-04-01

This work reports the qualitative and quantitative re-examination of legacy magnetotelluric soundings data obtained in the caldera of Nisyros, a small island volcano at the eastern end of the Hellenic Volcanic Arc (HVA), Greece, in an attempt to explore the high temperature geothermal resource of the area. The data set comprises 39 single-site soundings and is re-examined with improved data processing methods, new hypothetical event analysis techniques to study the spatial configuration of the telluric field and two-dimensional inversion tools. Iteratively reweighted least squares have been implemented to compute stable and smooth Earth response functions, which were found to exhibit 2-D to weakly 3-D attributes as a result of induction in low-contrast local geoelectric inhomogeneities, superimposed on a dominantly 2-D background structure. The transfer functions appear to be free of coastal and island induction effects due to the low offshore/onshore resistivity contrast at, and below sea level. The spatial properties of the telluric field are studied with hypothetical event analysis based on 3-D decompositions of the impedance tensor [1]. The results indicate that convection and hydrothermal circulation is controlled by a system of antithetic NE-SW oriented active normal faults which form a graben-like structure and define the 2-D background, as well as a conjugate system of NNW-SSE normal faults which is particularly active at the SW quadrant of the island and define the main convection path. It was determined that under these conditions the data can be interpreted with 2-D inversion, which was carried out with [2]. The inversion has successfully reconstructed detailed images of the structural and functional elements of the hydrothermal system. The structural elements include a number of shallow hot water reservoirs in the argillic and phyllic alteration zones and a laterally extended deep (approx. 1km) circulation zone, all embedded in a low-resistivity matrix

A 3D joint interpretation of magnetotelluric and seismic tomographic models: The case of the volcanic island of Tenerife

NASA Astrophysics Data System (ADS)

García-Yeguas, Araceli; Ledo, Juanjo; Piña-Varas, Perla; Prudencio, Janire; Queralt, Pilar; Marcuello, Alex; Ibañez, Jesús M.; Benjumea, Beatriz; Sánchez-Alzola, Alberto; Pérez, Nemesio

2017-12-01

In this work we have done a 3D joint interpretation of magnetotelluric and seismic tomography models. Previously we have described different techniques to infer the inner structure of the Earth. We have focused on volcanic regions, specifically on Tenerife Island volcano (Canary Islands, Spain). In this area, magnetotelluric and seismic tomography studies have been done separately. The novelty of the present work is the combination of both techniques in Tenerife Island. For this aim we have applied Fuzzy Clusters Method at different depths obtaining several clusters or classes. From the results, a geothermal system has been inferred below Teide volcano, in the center of Tenerife Island. An edifice hydrothermally altered and full of fluids is situated below Teide, ending at 600 m below sea level. From this depth the resistivity and VP values increase downwards. We also observe a clay cap structure, a typical feature in geothermal systems related with low resistivity and low VP values.

Cooperative Policies and African International Students: Do Policy Spirits Match Experiences?

ERIC Educational Resources Information Center

McLellan, Carlton E.

2009-01-01

This paper explores the policy implications of experiences of African international students (AIS) studying at post-apartheid South Africa universities. It argues that given the spirit and tone of continental, regional, and domestic policies to which South Africa has committed that at the very least there is an implicit expectation of…

The perspectives and experiences of African American students in an informal science program

NASA Astrophysics Data System (ADS)

Bulls, Domonique L.

Science, technology, engineering, and mathematics (STEM) fields are the fastest growing sectors of the economy, nationally and globally. In order for the United States (U.S.) to maintain its competitiveness, it is important to address STEM experiences at the precollege level. In early years, science education serves as a foundation and pipeline for students to pursue STEM in college and beyond. Alternative approaches to instruction in formal classrooms have been introduced to engage more students in science. One alternative is informal science education. Informal science education is an avenue used to promote science education literacy. Because it is less regulated than science teaching in formal classroom settings, it allows for the incorporation of culture into science instruction. Culturally relevant science teaching is one way to relate science to African American students, a population that continually underperforms in K-12 science education. This study explores the science perspectives and experiences of African American middle school students participating in an informal science program. The research is framed by the tenets of culturally relevant pedagogy and shaped by the following questions: (1) What specific aspects of the Carver Program make it unique to African American students? (2) How is culturally relevant pedagogy incorporated into the informal science program? (3) How does the incorporation of culturally relevant pedagogy into the informal science program influence African American students' perceptions about science? The findings to the previously stated questions add to the limited research on African American students in informal science learning environments and contribute to the growing research on culturally relevant science. This study is unique in that it explores the cultural components of an informal science program.

Three-dimensional magnetotelluric axial anisotropic forward modeling and inversion

NASA Astrophysics Data System (ADS)

Cao, Hui; Wang, Kunpeng; Wang, Tao; Hua, Boguang

2018-06-01

Magnetotelluric (MT) data has been widely used to image underground electrical structural. However, when the significant axial resistivity anisotropy presents, how this influences three-dimensional MT data has not been resolved clearly yet. We here propose a scheme for three-dimensional modeling of MT data in presence of axial anisotropic resistivity, where the electromagnetic fields are decomposed into primary and secondary components. A 3D staggered-grid finite difference method is then used to resolve the resulting 3D governing equations. Numerical tests have completed to validate the correctness and accuracy of the present algorithm. A limited-memory Broyden-Fletcher-Goldfarb-Shanno method is then utilized to realize the 3D MT axial anisotropic inversion. The testing results show that, compared to the results of isotropic resistivity inversion, taking account the axial anisotropy can much improve the inverted results.

Successfully Educating Our African-American Students

ERIC Educational Resources Information Center

Moncree-Moffett, Kareem

2013-01-01

The purpose of this empirical study was to explore the lived experiences of African American retired female teachers who have prior experience with educating urban African American students in public schools. Also explored are the experiences of active African American female teachers of urban African American students and comparisons are…

Analysis, results and conclusion of magnetotelluric data acquired in northern Switzerland

NASA Astrophysics Data System (ADS)

Shah, Neeraj; Samrock, Friedemann; Grayver, Alexander; Saar, Martin O.

2017-04-01

In early 2016, a magnetotelluric (MT) survey of the Aargau region of northern Switzerland was performed in order to understand the potential of the magnetotelluric method to characterise the electrical resistivity properties of the subsurface in Switzerland, and more widely, in areas with high amounts of cultural electromagnetic (EM) noise. Subsurface electrical resisitivity properties are interesting as they can help identify underground aquifers or geothermal resources and possibly provide insight into the large-scale movement of fluid. The north of Switzerland is a challenging and representative environment, with significant EM infrastructure, including powerlines and numerous other sources of noise related to human activity and use of industrial equipment. Here, we present the results of the survey together with detailed analysis of the issues encountered and challenges faced when doing this survey. In particular, we concentrate on data quality issues in the raw time series, the impact of using a remote reference over single site processing and the distribution of transfer functions. The final set of transfer functions for the survey, which includes twelve successful sites, is shown to suffer from noise issues in certain frequency ranges. A 1-D inversion of SSQ averaged transfer functions and comparison to existing borehole data demonstrates that geologic data is captured in the MT data recorded in northern Switzerland. Further, 2-D forward modelling supports the idea that good geologic information exists in the data despite the noise issues, which for now, impede a robust multi-dimensional inversion. Finally, suggestions for future work and methods to improve the quality of data when surveying in high EM noise environments are offered with a view to being able to reliably perform MT surveys closer to urban environments.

Toddler Feeding: Expectations and Experiences of Low-Income African American Mothers

ERIC Educational Resources Information Center

Horodynski, Mildred A.; Brophy-Herb, Holly; Henry, Michelle; Smith, Katharine A.; Weatherspoon, Lorraine

2009-01-01

Objective: To ascertain maternal expectations and experiences with mealtimes and feeding of toddlers among low-income African American mothers in two mid- to large-size cities in the United States. Design: Qualitative focus group study. Setting: Two Early Head Start programme sites in a Midwestern state which serve low income families. Method:…

Capacity development for health research in Africa: experiences managing the African Doctoral Dissertation Research Fellowship Program

PubMed Central

2010-01-01

Africa's progress depends on her capacity to generate, adapt, and use scientific knowledge to meet regional health and development needs. Yet, Africa's higher education institutions that are mandated to foster this capacity lack adequate resources to generate and apply knowledge, raising the need for innovative approaches to enhance research capacity. In this paper, we describe a newly-developed program to support PhD research in health and population sciences at African universities, the African Doctoral Dissertation Research Fellowship (ADDRF) Program. We also share our experiences implementing the program. As health research capacity-strengthening in Africa continues to attract attention and as the need for such programs to be African-led is emphasized, our experiences in developing and implementing the ADDRF offer invaluable lessons to other institutions undertaking similar initiatives. PMID:20587016

Achievement and Underachievement: The Experiences of African Caribbeans

ERIC Educational Resources Information Center

Rhamie, Jasmine

2012-01-01

The disproportionate representation of African Caribbeans in all the negative educational statistics has been well documented. Despite this, there are African Caribbeans who achieve academically but relatively few studies have explored this area. This study aimed to investigate the factors that contribute to African Caribbean academic success,…

An Intersectional Social Capital Analysis of the Influence of Historically Black Sororities on African American Women's College Experiences at a Predominantly White Institution

ERIC Educational Resources Information Center

Greyerbiehl, Lindsay; Mitchell, Donald, Jr.

2014-01-01

Research exploring the college experiences of African American women at predominantly White institutions (PWI) continues to be a necessity as African American women graduate at lower rates than their racial/ethnic peers. This qualitative study explored the influence historically Black sororities had on the college experiences of African American…

Magnetotelluric Data, Mid Valley, Nevada Test Site, Nevada.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackie M. Williams; Erin L. Wallin; Brian D. Rodriguez

2007-08-15

The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (CAU) (Bechtel Nevada, 2006).more » During 2003, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data at the Nevada Test Site in and near Yucca Flat (YF) to help define the character, thickness, and lateral extent of the pre-tertiary confining units. We collected 51 magnetotelluric (MT) and audio-magnetotelluric (AMT), stations for that research (Williams and others, 2005a, 2005b, 2005c, 2005d, 2005e, 2005f). In early 2005 we extended that research with 26 additional MT data stations (Williams and others, 2006), located on and near Rainier Mesa and Shoshone Mountain (RM-SM). The new stations extended the area of the hydrogeologic study previously conducted in Yucca Flat. This work was done to help refine what is known about the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal was to define the upper clastic confining unit (UCCU). The UCCU is comprised of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale. The UCCU underlies the Yucca Flat area and extends westward towards Shoshone Mountain, southward to Buckboard Mesa, and northward to Rainier Mesa. Late in 2005 we collected another 14 MT stations in Mid Valley and

Back to Africa in the 21st Century: The Cultural Reconnection Experiences of African American Women

ERIC Educational Resources Information Center

Arunga, Marcia Tate

2017-01-01

The purpose of this study is to examine the lived experiences of 18 African American women who went to Kenya, East Africa as part of a Cultural Reconnection delegation. A qualitative narrative inquiry method was used for data collection. This was an optimal approach to honoring the authentic voices of African American women. Eighteen African…

"A Fly in the Ointment": African American Male Preservice Teachers' Experiences with Stereotype Threat in Teacher Education

ERIC Educational Resources Information Center

Scott, Sonya V.; Rodriguez, Louie F.

2015-01-01

This study draws from a larger phenomenological study on African American academic persistence and career aspirations in education. This article highlights three African American males' experiences with concentrated forms of stereotype threat in teacher education. Their voices revealed dimensions of how power and privilege operate in teacher…

Identification the geothermal system using 1-D audio-magnetotelluric inversion in Lamongan volcano field, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Ilham, N.; Niasari, S. W.

2018-04-01

Tiris village, Probolinggo, East Java, is one of geothermal potential areas in Indonesia. This area is located in a valley flank of Mount Lamongan and Argopuro volcanic complex. This research aimed to identify a geothermal system at Tiris area, particularly the fluid pathways. The geothermal potential can be seen from the presence of warm springs with temperature ranging 35-45°C. The warm spring locations are aligned in the same orientation with major fault structure in the area. The fault structure shows dominant northwest-southeast orientation. We used audio-magnetotelluric data in the frequency range of 10 Hz until 92 kHz. The total magnetotelluric sites are 6. From the data analysis, most of the data orientation were 2-D with geo-electrical direction north-south. We used 1-D inversion using Newton algorithm. The 1-D inversion resulted in low resistive anomaly that corresponds to Lamongan lavas. Additionally, the depth of the resistor are different between the area to the west (i.e. 75 m) and to the east (i.e. 25 m). This indicates that there is a fault around the aligned maar (e.g. Ranu Air).

Striving to be in the profession and of It: the African American experience in physical education and kinesiology.

PubMed

Wiggins, David K; Wiggins, Brenda P

2011-06-01

This study analyzes the experiences of African Americans in the physical education and kinesiology profession since the late 1850s. Using a variety of primary and secondary source material, we place special emphasis on the experiences of African American physical educators in higher education and in the American Alliance for Health, Physical Education, Recreation and Dance and its southern, regional, and state chapters. Apparent from this examination is that African Americans have experienced various forms of racially discriminatory practices in physical education and kinesiology and have found it extraordinarily difficult to assume leader ship positions in the profession and be acknowledged for their scholarly and academic accomplishments.

Faith, Race, and LGB Affirmation: Experiences of African American Counselors-in-Training

ERIC Educational Resources Information Center

Harris, Janeé R. Avent; Roberston, Derek L.; Jones, Brenda; Prado, Ashley M.

2017-01-01

In this phenomenological study, the authors investigated the experiences of African American counselors-in-training, with roots in the Black church, as they navigated their faith and professional responsibilities to provide affirming services to lesbian, gay, and bisexual clients. Findings suggest attitudes toward lesbian, gay, and bisexual…

"I Want a Second Chance": Experiences of African American Fathers in Reentry.

PubMed

Dill, LeConté J; Mahaffey, Carlos; Mosley, Tracey; Treadwell, Henrie; Barkwell, Fabeain; Barnhill, Sandra

2016-11-01

With over 700,000 people on average released from prison each year to communities, greater attention is warranted on the experiences and needs of those who are parents and seeking to develop healthy relationships with their children and families. This study seeks to explore the experiences of African American fathers in reentry. Qualitative data from 16 African American men enrolled in a fellowship program for fathers were collected from a focus group and analyzed for common themes and using standpoint theory. Four themes emerged that focused on fathers' commitment toward healthy and successful reintegration postincarceration: redemption, employment, health care, and social support. Focus group participants actively strive to develop and rebuild healthy relationships with their children through seeking gainful employment and through bonding with like-minded peers. Barriers in accessing health care are also discussed. Research findings may inform future programs and policies related to supporting fathers and their children in reentry. © The Author(s) 2015.

The Road Not Taken: Two African-American Girls' Experiences with School Mathematics

ERIC Educational Resources Information Center

Lim, Jae Hoon

2008-01-01

This article is a cross-case study exploring two young African-American adolescent girls' experiences with school mathematics and the impact of the socio-cultural context upon their motivation and mathematical identity. Based on repeated in-depth interviews and ethnographic observation of their mathematics classroom, the researcher portrays…

Not Merely a Matter of Academics: Student Experiences of a South African University as Study-Abroad Destination

ERIC Educational Resources Information Center

Paola, R. J.; Lemmer, E. M.

2013-01-01

Study abroad programmes attract considerable numbers of American college students; however, very few select an African country as their study-abroad destination. This article explores the experiences of American undergraduates who made the uncommon choice of a South African university as destination for a mid-length immersion type programme. The…

APPLICATION OF AUDIO-MAGNETOTELLURIC SURVEYS ON SAO MIGUEL ISLAND, AZORES PORTUGAL.

USGS Publications Warehouse

Hoover, Donald; Rodrigues Da Silva, A.; Pierce, Herbert A.; Amaral, Roberto

1984-01-01

Geothermal exploration and development has been under way on Sao Miguel Island, Azores since 1975. This work had been restricted to the Fogo volcano, one of three dormant silicic volcanic centers on the island. The USGS in 1982 and 1983 conducted reconnaissance natural-source audio-magnetotelluric (AMT) surveys of all three silicic centers to evaluate the potential for geothermal systems at each and to demonstrate the utility of the method in areas of difficult terrain. Results on Fogo showed a low resistivity trend extending from the present production area upslope to the caldera boundary. The upper part of this trend is the upwelling zone of a thermal plume which supplies the production area. Further exploration and drilling are now planned for this area.

African American and European American Therapists' Experiences of Addressing Race in Cross-Racial Psychotherapy Dyads

ERIC Educational Resources Information Center

Knox, Sarah; Burkard, Alan W.; Johnson, Adanna J.; Suzuki, Lisa A.; Ponterotto, Joseph G.

2003-01-01

Using Consensual Qualitative Research, 12 licensed psychologists' overall experiences addressing race in psychotherapy were investigated, as were their experiences addressing race in a specific cross-racial therapy dyad. Results indicated that only African American psychologists reported routinely addressing race with clients of color or when race…

Magnetotelluric characterization of the northern margin of the Yilgarn Craton (Western Australia)

NASA Astrophysics Data System (ADS)

Piña-Varas, Perla; Dentith, Michael

2017-04-01

The northern margin of the Yilgarn Craton (Western Australia) was deformed during the convergence and collision with the Pilbara Craton and the intervening Glenburgh Terrain that created the Capricorn Orogen. The Yilgarn Craton is one of the most intensively mineralised areas of continental crust with world class deposits of gold and nickel. However, the region to its north has surprisingly few deposits. Cratonic margins are considered to be key indicators of prospectivity at a regional scale. The northern limit of the Yilgarn Craton within the Capricorn Orogen is not well resolved at date because of overlying Proterozoic sedimentary basins. We present here some of the results of an extensive magnetotelluric (MT) study that is being performed in the area. This study is a component of large multi-disciplinary geoscience project on the 'Distal Footprints of Giant Ore Systems' in the Capricorn Orogen. The MT dataset consists of a total of 240 broadband magnetotelluric stations (BBMT) and 84 long period stations (LMT). Analysis of the dataset reveals a clear 3-D geoelectrical behaviour and extreme complexity for most of the sites, including an extremely high number of sites with phases out-of-quadrant at long periods. 3-D inverse modelling of the MT data shows high resistivity Archean units and low resistivity Paleoproterozoic basins, including very low resistivity structures at depth. These strong resistivity contrasts allow us to successfully map northern margin of the Yilgarn Craton beneath basin cover, as well as identifying major lateral conductivity changes in the deep crust suggestive of different tectonic blocks. Upper crustal conductive zones can be correlated with faults on seismic reflection data. Our results suggest MT surveys are a useful tool for regional-scale exploration in the study area and in area of thick cover in general.

Magnetotelluric inversion via reverse time migration algorithm of seismic data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ha, Taeyoung; Shin, Changsoo

2007-07-01

We propose a new algorithm for two-dimensional magnetotelluric (MT) inversion. Our algorithm is an MT inversion based on the steepest descent method, borrowed from the backpropagation technique of seismic inversion or reverse time migration, introduced in the middle 1980s by Lailly and Tarantola. The steepest descent direction can be calculated efficiently by using the symmetry of numerical Green's function derived from a mixed finite element method proposed by Nedelec for Maxwell's equation, without calculating the Jacobian matrix explicitly. We construct three different objective functions by taking the logarithm of the complex apparent resistivity as introduced in the recent waveform inversionmore » algorithm by Shin and Min. These objective functions can be naturally separated into amplitude inversion, phase inversion and simultaneous inversion. We demonstrate our algorithm by showing three inversion results for synthetic data.« less

The social context of the aeronautical education experience of African-American civilian, commercial, and military pilots

NASA Astrophysics Data System (ADS)

Walker, Taurean Mashawn

The purpose of this research is to explore the social context (the nature and cultural environment) of the aeronautical training experience of African-American civilian, commercial, and military pilots. This research highlights the challenges African-American pilots are exposed to in addition to drawing parallels between the social context and the obstacles they are subjected to along the way. This study is valuable for stakeholders, African-American pilot aspirants, aviation corporations, Federal Aviation Administration, flight schools - in the aviation industry in understanding ways to initiate a paradigm shift and increase awareness about representation and participation of African-American aviation professionals. The qualitative approach was selected to gather a better understanding of the sociological hurdles black aviators face while going through the journey of becoming a pilot. Hardiman (2010) states, "While quantitative research is valuable, qualitative research provides the researcher the ability to view real world situations as they naturally unfold" ( p. 25). According to OBAP (2014), less than 2% of pilots in the United States are African-American. The experiences shared by the participants can provide helpful insight of possible policy implications for the aeronautical industry. There were three research questions in the study: 1) What factors hindered pilot training? 2) What were the resilience factors experienced during pilot training? 3) What were the defining features of the social context surrounding pilot training? Semi-structured, face-to-face interviews were conducted of six professional pilots. A qualitative data analysis was conducted to illustrate the context of the social challenges during the course of pilot training. Three themes were revealed: 1) access, 2) perception of inferiority, and 3) support. Implications of the significance of providing social networks to expose African-Americans to aviation were discussed. Additional means of

End-of-life experiences and expectations of Africans in Australia: cultural implications for palliative and hospice care.

PubMed

Hiruy, Kiros; Mwanri, Lillian

2014-03-01

The ageing and frail migrants who are at the end of life are an increasing share of migrants living in Australia. However, within such populations, information about end-of-life experiences is limited, particularly among Africans. This article provides some insights into the sociocultural end-of-life experiences of Africans in Australia and their interaction with the health services in general and end-of-life care in particular. It provides points for discussion to consider an ethical framework that include Afro-communitarian ethical principles to enhance the capacity of current health services to provide culturally appropriate and ethical care. This article contributes to our knowledge regarding the provision of culturally appropriate and ethical care to African patients and their families by enabling the learning of health service providers to improve the competence of palliative care systems and professionals in Australia. Additionally, it initiates the discussion to highlight the importance of paying sufficient attention to a diverse range of factors including the migration history when providing palliative and hospice care for patients from African migrant populations.

Informal and Incidental Learning Experiences of African American Women That Shaped and Influenced Their Leadership Development and Style

ERIC Educational Resources Information Center

Clark, Marilyn Ann

2013-01-01

The primary purpose of this study was to examine how African American women in corporations develop leadership and construct their leadership style through informal and incidental learning experiences. This study explored relationships between informal adult learning and career mapping processes of leadership for African American women. A…

Magnetotelluric investigations of the lithosphere beneath the central Rae craton, mainland Nunavut, Canada

NASA Astrophysics Data System (ADS)

Spratt, Jessica E.; Skulski, Thomas; Craven, James A.; Jones, Alan G.; Snyder, David B.; Kiyan, Duygu

2014-03-01

New magnetotelluric soundings at 64 locations throughout the central Rae craton on mainland Nunavut constrain 2-D resistivity models of the crust and lithospheric mantle beneath three regional transects. Responses determined from colocated broadband and long-period magnetotelluric recording instruments enabled resistivity imaging to depths of > 300 km. Strike analysis and distortion decomposition on all data reveal a regional trend of 45-53°, but locally the geoelectric strike angle varies laterally and with depth. The 2-D models reveal a resistive upper crust to depths of 15-35 km that is underlain by a conductive layer that appears to be discontinuous at or near major mapped geological boundaries. Surface projections of the conductive layer coincide with areas of high grade, Archean metasedimentary rocks. Tectonic burial of these rocks and thickening of the crust occurred during the Paleoproterozoic Arrowsmith (2.3 Ga) and Trans-Hudson orogenies (1.85 Ga). Overall, the uppermost mantle of the Rae craton shows resistivity values that range from 3000 Ω m in the northeast (beneath Baffin Island and the Melville Peninsula) to 10,000 Ω m beneath the central Rae craton, to >50,000 Ω m in the south near the Hearne Domain. Near-vertical zones of reduced resistivity are identified within the uppermost mantle lithosphere that may be related to areas affected by mantle melt or metasomatism associated with emplacement of Hudsonian granites. A regional decrease in resistivities to values of 500 Ω m at depths of 180-220 km, increasing to 300 km near the southern margin of the Rae craton, is interpreted as the lithosphere-asthenosphere boundary.

Experiences of Racism Among African American Parents and the Mental Health of Their Preschool-Aged Children

PubMed Central

Caughy, Margaret O'Brien; O'Campo, Patricia J.; Muntaner, Carles

2004-01-01

Objectives. We examined the relationship between parents’ experiences of racism and children’s well-being and the influence of the residential neighborhood characteristics on this relationship. Methods. African American families were recruited from Baltimore neighborhoods. Parental measures included racism experiences and coping. Neighborhood measures included demographic characteristics, social cohesion, and social climate. Children’s mental health was assessed with the Child Behavior Checklist. Analysis was performed with multilevel modeling. Results. Parents who denied experiences of racism also reported higher rates of behavior problems among their preschool-aged children. For families living in neighborhoods characterized by fear of victimization, parents who actively coped with racism experiences by confronting the person involved or taking some sort of action in response to racism reported lower rates of anxiety and depression for their preschool-aged children. Conclusions. Experiences of and responses to racism among African American parents have important effects on the well-being of their young children. PMID:15569963

Disability and Health: Exploring the Disablement Experience of Young Adult African Americans

PubMed Central

Harrison, Tracie

2013-01-01

Purpose The objective of this study was to examine disablement as experienced by young adult African American men and women with permanent mobility impairment. Methods This study included a sample of 5 male and 5 female participants ranging in age from 22 to 39. An exploratory descriptive design and qualitative methods, including interviews and fieldnotes, were used. Interview data was analyzed using the process of inductive qualitative content analysis. Results Basic desires for independence, shared intimacy, and psychological and physical health were not diminished by physical limitations. The disablement experience of this group is reflected in the themes of “Cumulative Losses” and “Sustained Desires.” The findings of this study describe the high level of motivation that young adult African American men and women with disabilities have to improve levels of health and well-being within the context of their impairments. Conclusion This study provides a better understanding of the contextual factors and experiences that may contribute to the development of further disability and subsequent health-related problems over time. Increased knowledge of the disablement experience of these young men and women may assist health care entities and social service providers in improving health care and rehabilitation efforts targeting this group. PMID:23745770

A 3D Magnetotelluric Perspective on the Galway Granite, Western Ireland

NASA Astrophysics Data System (ADS)

Farrell, Thomas; Muller, Mark; Vozar, Jan; Feely, Martin; Hogg, Colin

2017-04-01

Magnetotelluric (MT) and audi-magnetotelluric (AMT) data were acquired at 75 locations across the exposed calc-alkaline Caledonian Galway granite batholith and surrounding country rocks into which the granite intruded. The Galway granite is located in western Ireland on the north shore of Galway bay, and has an ESE-WNW long axis. The granite is cut by trans-batholith faults, the Shannawona Fault Zone (SFZ) in the western part of the batholith, which has a NE-SW trend, and the Bearna Fault Zone (BFZ) in the eastern sector that has a NW-SE trend. Geobarometry data indicate that the central granite block between these fault zones has been uplifted, with the interpretation being that the granite in this central block is thinned. To the west of the SFZ, much of the Galway granite is below sea level, with the majority of the southern granite contact also beneath the sea in Galway bay. To the east of the batholith, the Carboniferous successions, consisting of mainly limestone with shale, overlie the basement rocks. The country rock to the north includes the metagabbro-gneiss suite, which itself intruded the deformed Dalradian successions that were deposited on the Laurentian margin of the Iapetus Ocean. The deformation of the Dalradian rocks, the intrusion of the metagabbro-gneiss suite and the intrusion of the Galway granite were major events in the protracted closure of the Iapetus Ocean. It is clear from geological mapping, from geobarometry and from the present submergence by the sea of a large part of the Galway granite, that inversion of MT data in this structurally complex geology is likely to require a 3D approach. We present a summary of 3D inversion of the Galway MT and AMT data. The study shows that the structure of the Galway granite is quite different from the pre-existing perspective. The central block, thought by its uplifting to be thinned, is shown to be the thickest part of the batholith. A geological model of granite intrusion is offered to explain this

Magnetotelluric investigation of the geothermal anomaly in Hailin, Mudanjiang, northeastern China

NASA Astrophysics Data System (ADS)

Zhang, Lili; Hao, Tianyao; Xiao, Qibin; Wang, Jie; Zhou, Liang; Qi, Min; Cui, Xiangpan; Cai, Ningxiao

2015-07-01

To study the occurrence conditions and locations of geothermal bodies in Hailin, Mudanjiang, northeastern China, we conducted a magnetotelluric investigation to delineate the electrical conductivity structure of the area on three parallel profiles. The area to the west of the Mudanjiang Fault lies in the Hailang sag of the Ning'an Basin. The data were processed using the mutual reference technique, static shift correction, and structural strike and dimensionality analysis based on tensor decomposition. Moreover, a modified anisotropic-diffusion-based method was used to suppress noise for the magnetotelluric time series data. This method retains the advantages of conventional anisotropic diffusion and is superior in its discrimination ability. The method is characteristic not only of the inherited features such as intra-region smoothing and edge preservation, but also of the adaptive selection of the diffusion coefficient. Data analysis revealed that the electrical resistivity structure can be approximated by a two-dimensional characterization. Two-dimensional inversion and rendering visualization show that a highly resistive granite basement is covered with conductive sedimentary layers and that a relatively low-resistivity anomalous structure with a resistivity of approximately 100-600 Ω·m is imbedded in the high-resistivity background. The anomalous structure has a narrow top and a wide bottom (the bottom depth is at least 3500 m). The shape and electrical features of the structure indicate favorable storage space for hot subsurface water. Fault activities and magma intrusion may result in the fractures of the basement, which are filled with hot water and thus produce the relatively low resistivity. Based on a comprehensive analysis, we infer that the structure is indicative of a geothermal reservoir. An exploratory well drilled near the structure confirms the occurrence of high temperatures. Several geological factors (cap rock, basement, and major faults

Creating Supportive Learning Environments: Experiences of Lesbian and Gay-Parented Families in South African Schools

ERIC Educational Resources Information Center

Breshears, Diana; Lubbe-De Beer, Carien

2016-01-01

Through in-depth interviews with 21 parents and 12 children in lesbian/gay-parented families, we explored the experiences of this unique family form in South African schools. Specifically, families reflected on their positive and negative experiences in the children's education and used these reflections to offer advice to teachers and…

The structure of a Mesozoic basin beneath the Lake Tana area, Ethiopia, revealed by magnetotelluric imaging

NASA Astrophysics Data System (ADS)

Hautot, Sophie; Whaler, Kathryn; Gebru, Workneh; Desissa, Mohammednur

2006-03-01

The northwestern Plateau of Ethiopia is almost entirely covered with extensive Tertiary continental flood basalts that mask the underlying formations. Mesozoic and Tertiary sediments are exposed in a few locations surrounding the Lake Tana area suggesting that the Tana depression is an extensional basin buried by the 1-2 km thick Eocene-Oligocene flood basalt sequences in this region. A magnetotelluric survey has been carried out to investigate the deep structure of the Tana area. The objectives were to estimate the thickness of the volcanics and anticipated underlying sedimentary basin. We have collected 27 magnetotelluric soundings south and east of Lake Tana. Two-dimensional inversion of the data along a 160 km long profile gives a model consistent with a NW-SE trending sedimentary basin beneath the lava flows. The thickness of sediments overlying the Precambrian basement averages 1.5-2 km, which is comparable to the Blue Nile stratigraphic section, south of the area. A 1 km thickening of sediments over a 30-40 km wide section suggests that the form of the basin is a half-graben. It is suggested that electrically resistive features in the model are related to volcanic materials intruded within the rift basin sediments through normal faults. The results illustrate the strong control of the Precambrian fracture zones on the feeding of the Tertiary Trap series.

Teacher and Parent Perceptions of Classroom Experiences of African American Male Students in a High School Alternative Program

ERIC Educational Resources Information Center

Johnson, Kimberly C.

2013-01-01

A major concern in the public schools is the low academic achievement of African American males. This mixed methods study examined the classroom experiences of African American male students in an alternative program. The dual purpose was to investigate the teachers' perceptions and their ability to provide best learning environments for…

A Decade of Experience With Renal Transplantation in African-Americans

PubMed Central

Foster, Clarence E.; Philosophe, Benjamin; Schweitzer, Eugene J.; Colonna, John O.; Farney, Alan C.; Jarrell, Bruce; Anderson, Leslie; Bartlett, Stephen T.

2002-01-01

Objective To evaluate the strategies instituted by the authors’ center to decrease the time to transplantation and increase the rate of transplantation for African-Americans, consisting of a formal education program concerning the benefits of living organ donation that is oriented to minorities; a laparoscopic living donation program; use of hepatitis C-positive donors in documented positive recipients; and encouraging vaccination for hepatitis B, allowing the use of hepatitis B core Ab-positive donors. Summary Background Data The national shortage of suitable kidney donor organs has disproportional and adverse effects on African-Americans for several reasons. Type II diabetes mellitus and hypertension, major etiologic factors for end-stage renal disease, are more prevalent in African-Americans than in the general population. Once kidney failure has developed, African-Americans are disadvantaged for the following reasons: this patient cohort has longer median waiting times on the renal transplant list; African-Americans have higher rates of acute rejection, which affects long-term allograft survival; and once they are transplanted, the long-term graft survival rates are lower in this population than in other groups. Methods From March 1990 to November 2001 the authors’ center performed 2,167 renal transplants; 944 were in African-Americans (663 primary cadaver renal transplants and 253 primary Living donor renal transplants). The retransplants consisted of 83 cadaver transplants and 17 living donor transplants. Outcome measures of this retrospective analysis included median waiting time, graft and patient survival rates, and the rate of living donation in African-Americans and comparable non-African-Americans. Where applicable, data are compared to United Network for Organ Sharing national statistics. Statistical analysis employed appropriate SPSS applications. Results One- and 5-year patient survival rates for living donor kidneys were 97.1% and 91.3% for non-African

A decade of experience with renal transplantation in African-Americans.

PubMed

Foster, Clarence E; Philosophe, Benjamin; Schweitzer, Eugene J; Colonna, John O; Farney, Alan C; Jarrell, Bruce; Anderson, Leslie; Bartlett, Stephen T

2002-12-01

OBJECTIVE To evaluate the strategies instituted by the authors' center to decrease the time to transplantation and increase the rate of transplantation for African-Americans, consisting of a formal education program concerning the benefits of living organ donation that is oriented to minorities; a laparoscopic living donation program; use of hepatitis C-positive donors in documented positive recipients; and encouraging vaccination for hepatitis B, allowing the use of hepatitis B core Ab-positive donors. SUMMARY BACKGROUND DATA The national shortage of suitable kidney donor organs has disproportional and adverse effects on African-Americans for several reasons. Type II diabetes mellitus and hypertension, major etiologic factors for end-stage renal disease, are more prevalent in African-Americans than in the general population. Once kidney failure has developed, African-Americans are disadvantaged for the following reasons: this patient cohort has longer median waiting times on the renal transplant list; African-Americans have higher rates of acute rejection, which affects long-term allograft survival; and once they are transplanted, the long-term graft survival rates are lower in this population than in other groups. METHODS From March 1990 to November 2001 the authors' center performed 2,167 renal transplants; 944 were in African-Americans (663 primary cadaver renal transplants and 253 primary Living donor renal transplants). The retransplants consisted of 83 cadaver transplants and 17 living donor transplants. Outcome measures of this retrospective analysis included median waiting time, graft and patient survival rates, and the rate of living donation in African-Americans and comparable non-African-Americans. Where applicable, data are compared to United Network for Organ Sharing national statistics. Statistical analysis employed appropriate SPSS applications. RESULTS One- and 5-year patient survival rates for living donor kidneys were 97.1% and 91.3% for non-African

MTpy: A Python toolbox for magnetotellurics

NASA Astrophysics Data System (ADS)

Krieger, Lars; Peacock, Jared R.

2014-11-01

We present the software package MTpy that allows handling, processing, and imaging of magnetotelluric (MT) data sets. Written in Python, the code is open source, containing sub-packages and modules for various tasks within the standard MT data processing and handling scheme. Besides the independent definition of classes and functions, MTpy provides wrappers and convenience scripts to call standard external data processing and modelling software. In its current state, modules and functions of MTpy work on raw and pre-processed MT data. However, opposite to providing a static compilation of software, we prefer to introduce MTpy as a flexible software toolbox, whose contents can be combined and utilised according to the respective needs of the user. Just as the overall functionality of a mechanical toolbox can be extended by adding new tools, MTpy is a flexible framework, which will be dynamically extended in the future. Furthermore, it can help to unify and extend existing codes and algorithms within the (academic) MT community. In this paper, we introduce the structure and concept of MTpy. Additionally, we show some examples from an everyday work-flow of MT data processing: the generation of standard EDI data files from raw electric (E-) and magnetic flux density (B-) field time series as input, the conversion into MiniSEED data format, as well as the generation of a graphical data representation in the form of a Phase Tensor pseudosection.

Magnetotelluric Data, San Luis Valley, Colorado

USGS Publications Warehouse

Rodriguez, Brian D.; Williams, Jackie M.

2008-01-01

The San Luis Valley region population is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region?s ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal ground-water aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin located in southern Colorado. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey (called magnetotellurics, or MT), and hydrologic and lithologic data are being used to better understand the aquifers. The MT survey primary goal is to map changes in electrical resistivity with depth that are related to differences in rock types. These various rock types help control the properties of aquifers. This report does not include any data interpretation. Its purpose is to release the MT data acquired at 24 stations. Two of the stations were collected near Santa Fe, New Mexico, near deep wildcat wells. Well logs from those wells will help tie future interpretations of this data with geologic units from the Santa Fe Group sediments to Precambrian basement.

In Their Own Voices: Adolescent African American Males' Experiences of the Achievement Gap

ERIC Educational Resources Information Center

Moon, Natasha S.; Singh, Anneliese A.

2015-01-01

The authors use a phenomenological research tradition grounded in CRT tenets to describe the daily lived experiences that 12 male African American youth had in relation to the achievement gap. Researchers collected individual semi-structured interviews and focus group data related to the study phenomenon. There were five themes identified in…

Resistivity structure of Sumatran Fault (Aceh segment) derived from 1-D magnetotelluric modeling

NASA Astrophysics Data System (ADS)

Nurhasan, Sutarno, D.; Bachtiar, H.; Sugiyanto, D.; Ogawa, Y.; Kimata, F.; Fitriani, D.

2012-06-01

Sumatran Fault Zone is the most active fault in Indonesia as a result of strike-slip component of Indo-Australian oblique convergence. With the length of 1900 km, Sumatran fault was divided into 20 segments starting from the southernmost Sumatra Island having small slip rate and increasing to the north end of Sumatra Island. There are several geophysical methods to analyze fault structure depending on physical parameter used in these methods, such as seismology, geodesy and electromagnetic. Magnetotelluric method which is one of geophysical methods has been widely used in mapping and sounding resistivity distribution because it does not only has the ability for detecting contras resistivity but also has a penetration range up to hundreds of kilometers. Magnetotelluric survey was carried out in Aceh region with the 12 total sites crossing Sumatran Fault on Aceh and Seulimeum segments. Two components of electric and magnetic fields were recorded during 10 hours in average with the frequency range from 320 Hz to 0,01 Hz. Analysis of the pseudosection of phase and apparent resistivity exhibit vertical low phase flanked on the west and east by high phase describing the existence of resistivity contras in this region. Having rotated the data to N45°E direction, interpretation of the result has been performed using three different methods of 1D MT modeling i.e. Bostick inversion, 1D MT inversion of TM data, and 1D MT inversion of the impedance determinant. By comparison, we concluded that the use of TM data only and the impedance determinant in 1D inversion yield the more reliable resistivity structure of the fault compare to other methods. Based on this result, it has been shown clearly that Sumatra Fault is characterized by vertical contras resistivity indicating the existence of Aceh and Seulimeum faults which has a good agreement with the geological data.

Health Care Experiences and Perceived Barriers to Health Care Access: A Qualitative Study Among African Migrants in Guangzhou, Guangdong Province, China

PubMed Central

Brown, Katherine B.; Yu, Fan; Yang, Jingqi; Wang, Jason; Schrock, Joshua M.; Bodomo, Adams B.; Yang, Ligang; Yang, Bin; Nehl, Eric J.; Tucker, Joseph D.; Wong, Frank Y.

2014-01-01

Guangzhou, one of China's largest cities and a main trading port in South China, has attracted many African businessmen and traders migrating to the city for financial gains. Previous research has explored the cultural and economic roles of this newly emerging population; however, little is known about their health care experiences while in China. Semi-structured interviews and focus groups were used to assess health care experiences and perceived barriers to health care access among African migrants in Guangzhou, China. Overall, African migrants experienced various barriers to accessing health care and were dissatisfied with local health services. The principal barriers to care reported included affordability, legal issues, language barriers, and cultural differences. Facing multiple barriers, African migrants have limited access to care in Guangzhou. Local health settings are not accustomed to the African migrant population, suggesting that providing linguistically and culturally appropriate services may improve access to care for the migrants. PMID:25294415

Barriers to Persistence in Adult Basic Education: The Experiences of African American Learners

ERIC Educational Resources Information Center

Thomas, Simone

2011-01-01

One of the most pervasive issues facing educators and administrators in Adult Basic Education (ABE) is student persistence. The purposes of this qualitative study were 1) to identify the experiences that African American adult learners associated with their decisions to leave ABE programs; 2) to ascertain the impact of participants'…

A study of the lived experiences of African American women STEM doctoral degree completers

NASA Astrophysics Data System (ADS)

Squires, Stephanie Michelle

This study examined the lived experiences of African American women (AAW) who completed doctoral degrees in a STEM (science, technology, engineering, and mathematics) discipline in the United States. This study sought to fill the gap in the literature by examining how AAW described and made meaning of lived STEM educational experiences during doctoral degree completion in the context of the intersection of being African American and a woman. This study utilized a theoretical perspective based upon three theories: (a) critical race theory as a framework to gather AAW's narratives about STEM doctorate education, (b) Black feminist thought as a framework to view the intersection of being African American and a woman in the United States, and (c) the science identity model as a framework to view how women of color successfully complete scientific graduate degrees. Participants revealed that being an African American and a woman in a STEM doctoral program often complicated an already difficult process of completing the doctoral degree. The participants described the educational experience as challenging, particularly the writing of the dissertation. The challenges that the participants faced were due to various factors such as difficult advisor/advisee relationships, tedious writing and revision processes, politics, and lack of information regarding the doctoral degree process. The findings suggested that AAW participants confronted intrinsic bias while completing STEM doctoral degrees, which led to isolation and feelings of being an impostor---or feelings of not belonging in scientific studies. The findings also indicated that the women in this study ascribed success in dissertation writing and degree completion to one or more of the following attributes: (a) having a clear plan, (b) taking ownership of the writing process, (c) having an engaged advisor, (d) learning the writing style of the advisor, (e) understanding the temperament of the advisor, (f) personal will

The experience of terminating an abusive relationship from an Anglo and African American perspective: a qualitative descriptive study.

PubMed

Moss, V A; Pitula, C R; Campbell, J C; Halstead, L

1997-01-01

A common question asked about abused women is, "Why don't they leave?" This qualitative study explored the experiences of 15 African American and 15 Anglo American women who had terminated abusive relationships. The constant comparative method of analysis of audiotaped interviews revealed a 3-phase process of leaving: being in, getting out, and going on. Participants endured abuse until they could relinquish the fantasy of a happy relationship. Differences in relationship power and public response to abuse distinguished the experiences of Anglo and African American participants. Findings support the notion of leaving as a social process with similarities across both groups. However, critical differences in responses suggest that leaving is a culture-bound experience.

A data variance technique for automated despiking of magnetotelluric data with a remote reference

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kappler, K.

2011-02-15

The magnetotelluric method employs co-located surface measurements of electric and magnetic fields to infer the local electrical structure of the earth. The frequency-dependent 'apparent resistivity' curves can be inaccurate at long periods if input data are contaminated - even when robust remote reference techniques are employed. Data despiking prior to processing can result in significantly more reliable estimates of long period apparent resistivities. This paper outlines a two-step method of automatic identification and replacement for spike-like contamination of magnetotelluric data; based on the simultaneity of natural electric and magnetic field variations at distant sites. This simultaneity is exploited both tomore » identify windows in time when the array data are compromised, and to generate synthetic data that replace observed transient noise spikes. In the first step, windows in data time series containing spikes are identified via intersite comparison of channel 'activity' - such as the variance of differenced data within each window. In the second step, plausible data for replacement of flagged windows is calculated by Wiener filtering coincident data in clean channels. The Wiener filters - which express the time-domain relationship between various array channels - are computed using an uncontaminated segment of array training data. Examples are shown where the algorithm is applied to artificially contaminated data, and to real field data. In both cases all spikes are successfully identified. In the case of implanted artificial noise, the synthetic replacement time series are very similar to the original recording. In all cases, apparent resistivity and phase curves obtained by processing the despiked data are much improved over curves obtained from raw data.« less

Investigation of Magnetotelluric Source Effect Based on Twenty Years of Telluric and Geomagnetic Observation

NASA Astrophysics Data System (ADS)

Kis, A.; Lemperger, I.; Wesztergom, V.; Menvielle, M.; Szalai, S.; Novák, A.; Hada, T.; Matsukiyo, S.; Lethy, A. M.

2016-12-01

Magnetotelluric method is widely applied for investigation of subsurface structures by imaging the spatial distribution of electric conductivity. The method is based on the experimental determination of surface electromagnetic impedance tensor (Z) by surface geomagnetic and telluric registrations in two perpendicular orientation. In practical explorations the accurate estimation of Z necessitates the application of robust statistical methods for two reasons:1) the geomagnetic and telluric time series' are contaminated by man-made noise components and2) the non-homogeneous behavior of ionospheric current systems in the period range of interest (ELF-ULF and longer periods) results in systematic deviation of the impedance of individual time windows.Robust statistics manage both load of Z for the purpose of subsurface investigations. However, accurate analysis of the long term temporal variation of the first and second statistical moments of Z may provide valuable information about the characteristics of the ionospheric source current systems. Temporal variation of extent, spatial variability and orientation of the ionospheric source currents has specific effects on the surface impedance tensor. Twenty year long geomagnetic and telluric recordings of the Nagycenk Geophysical Observatory provides unique opportunity to reconstruct the so called magnetotelluric source effect and obtain information about the spatial and temporal behavior of ionospheric source currents at mid-latitudes. Detailed investigation of time series of surface electromagnetic impedance tensor has been carried out in different frequency classes of the ULF range. The presentation aims to provide a brief review of our results related to long term periodic modulations, up to solar cycle scale and about eventual deviations of the electromagnetic impedance and so the reconstructed equivalent ionospheric source effects.

African American College Students' Experience of Racial Discrimination and the Role of College Hassles

ERIC Educational Resources Information Center

Banks, Kira Hudson

2010-01-01

The current study examines the relationship between racial discrimination and depressive symptoms. In particular, it investigated whether college hassles moderated or mediated the relationship. Participants included 194 African American students from a large, Midwestern, state university. Participants provided self-report of their experience of…

African American Adolescents' Discrimination Experiences and Academic Achievement: Racial Socialization as a Cultural Compensatory and Protective Factor

ERIC Educational Resources Information Center

Neblett, Enrique W., Jr.; Philip, Cheri L.; Cogburn, Courtney D.; Sellers, Robert M.

2006-01-01

This study examines the interrelationships among racial discrimination experiences, parent race socialization practices, and academic achievement outcomes in a sample of 548 African American adolescents. Adolescents' racial discrimination experiences were associated with a decrease in academic curiosity, persistence, and student self-reported…

Interpretation of magnetotelluric resistivity and phase soundings over horizontal layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patella, D.

1976-02-01

The present paper deals with a new inverse method for quantitatively interpreting magnetotelluric apparent resistivity and phase-lag sounding curves over horizontally stratified earth sections. The recurrent character of the general formula relating the wave impedance of an (n-l)-layered medium to that of an n-layered medium suggests the use of the method of reduction to a lower boundary plane, as originally termed by Koefoed in the case of dc resistivity soundings. The layering parameters are so directly derived by a simple iterative procedure. The method is applicable for any number of layers but only when both apparent resistivity and phase-lag soundingmore » curves are jointly available. Moreover no sophisticated algorithm is required: a simple desk electronic calculator together with a sheet of two-layer apparent resistivity and phase-lag master curves are sufficient to reproduce earth sections which, in the range of equivalence, are all consistent with field data.« less

Signal-Noise Identification of Magnetotelluric Signals Using Fractal-Entropy and Clustering Algorithm for Targeted De-Noising

NASA Astrophysics Data System (ADS)

Li, Jin; Zhang, Xian; Gong, Jinzhe; Tang, Jingtian; Ren, Zhengyong; Li, Guang; Deng, Yanli; Cai, Jin

A new technique is proposed for signal-noise identification and targeted de-noising of Magnetotelluric (MT) signals. This method is based on fractal-entropy and clustering algorithm, which automatically identifies signal sections corrupted by common interference (square, triangle and pulse waves), enabling targeted de-noising and preventing the loss of useful information in filtering. To implement the technique, four characteristic parameters — fractal box dimension (FBD), higuchi fractal dimension (HFD), fuzzy entropy (FuEn) and approximate entropy (ApEn) — are extracted from MT time-series. The fuzzy c-means (FCM) clustering technique is used to analyze the characteristic parameters and automatically distinguish signals with strong interference from the rest. The wavelet threshold (WT) de-noising method is used only to suppress the identified strong interference in selected signal sections. The technique is validated through signal samples with known interference, before being applied to a set of field measured MT/Audio Magnetotelluric (AMT) data. Compared with the conventional de-noising strategy that blindly applies the filter to the overall dataset, the proposed method can automatically identify and purposefully suppress the intermittent interference in the MT/AMT signal. The resulted apparent resistivity-phase curve is more continuous and smooth, and the slow-change trend in the low-frequency range is more precisely reserved. Moreover, the characteristic of the target-filtered MT/AMT signal is close to the essential characteristic of the natural field, and the result more accurately reflects the inherent electrical structure information of the measured site.

The Soul of Leadership: African American Students' Experiences in Historically Black and Predominantly White Organizations

ERIC Educational Resources Information Center

Hotchkins, Bryan K.

2013-01-01

This study addresses African American students' leadership experiences at predominantly White institutions. Findings indicated participants utilized servant leadership in historically Black organizations and transformational leadership in predominantly White organizations. The differences displayed showed that participants' leadership perceptions…

Writing Experiences and Expectations of African American Students: Two Year College Composition Course

ERIC Educational Resources Information Center

Khan, Sakeena

2017-01-01

This dissertation study has sought to understand both the experiences and expectations provided to students participating in a single basic writing course at a two-year college. Analysis of student writing artifacts, with the goal of comparing 21st century student written purpose with the written purposes shown in 19th century African American…

Maternity health care: The experiences of Sub-Saharan African women in Sub-Saharan Africa and Australia.

PubMed

Mohale, Hlengiwe; Sweet, Linda; Graham, Kristen

2017-08-01

Increasing global migration is resulting in a culturally diverse population in the receiving countries. In Australia, it is estimated that at least four thousand Sub-Saharan African women give birth each year. To respond appropriately to the needs of these women, it is important to understand their experiences of maternity care. The study aimed to examine the maternity experiences of Sub-Saharan African women who had given birth in both Sub-Saharan Africa and in Australia. Using a qualitative approach, 14 semi-structured interviews with Sub-Saharan African women now living in Australia were conducted. Data was analysed using Braun and Clark's approach to thematic analysis. Four themes were identified; access to services including health education; birth environment and support; pain management; and perceptions of care. The participants experienced issues with access to maternity care whether they were located in Sub-Saharan Africa or Australia. The study draws on an existing conceptual framework on access to care to discuss the findings on how these women experienced maternity care. The study provides an understanding of Sub-Saharan African women's experiences of maternity care across countries. The findings indicate that these women have maternity health needs shaped by their sociocultural norms and beliefs related to pregnancy and childbirth. It is therefore arguable that enhancing maternity care can be achieved by improving women's health literacy through health education, having an affordable health care system, providing respectful and high quality midwifery care, using effective communication, and showing cultural sensitivity including family support for labouring women. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

"You learn to go last": perceptions of prenatal care experiences among African-American women with limited incomes.

PubMed

Salm Ward, Trina C; Mazul, Mary; Ngui, Emmanuel M; Bridgewater, Farrin D; Harley, Amy E

2013-12-01

African American infants die at higher rates and are at greater risk of adverse birth outcomes than White infants in Milwaukee. Though self-reported experiences of racism have been linked to adverse health outcomes, limited research exists on the impact of racism on women's prenatal care experiences. The purpose of this study was to examine the experiences of racial discrimination during prenatal care from the perspectives of African American women in a low income Milwaukee neighborhood. Transcripts from six focus groups with twenty-nine women and two individual interviews were analyzed to identify important emergent themes. Validity was maintained using an audit trail, peer debriefing, and two individual member validation sessions. Participants identified three areas of perceived discrimination based on: (1) insurance or income status, (2) race, and (3) lifetime experiences of racial discrimination. Women described being treated differently by support staff and providers based on type of insurance (public versus private), including perceiving a lower quality of care at clinics that accepted public insurance. While some described personally-mediated racism, the majority of women described experiences that fit within a definition of institutionalized racism-in which the system was designed in a way that worked against their attempts to get quality prenatal care. Women also described lifetime experiences of racial discrimination. Our findings suggest that African American women with limited incomes perceive many provider practices and personal interactions during prenatal care as discriminatory. Future studies could explore the relationship between perceptions of discrimination and utilization of prenatal care.

Resilience Post Tenure: The Experience of an African American Woman in a PWI

ERIC Educational Resources Information Center

Behar-Horenstein, Linda S.; West-Olatunji, Cirecie A.; Moore, Thomas E.; Houchen, Deidre F.; Roberts, Kellie W.

2012-01-01

The purpose of this study was: 1) to explore the pre-tenure experiences of an African American female faculty member in a counselor education program; and 2) to compare the themes that ascended from a precursor study to the current one. By using critical ethnography and case study format, this research gave voice to the participant by prompting…

Portable audio magnetotellurics - experimental measurements and joint inversion with radiomagnetotelluric data from Gotland, Sweden

NASA Astrophysics Data System (ADS)

Shan, Chunling; Kalscheuer, Thomas; Pedersen, Laust B.; Erlström, Mikael; Persson, Lena

2017-08-01

Field setup of an audio magnetotelluric (AMT) station is a very time consuming and heavy work load. In contrast, radio magnetotelluric (RMT) equipment is more portable and faster to deploy but has shallower investigation depth owing to its higher signal frequencies. To increase the efficiency in the acquisition of AMT data from 10 to 300 Hz, we introduce a modification of the AMT method, called portable audio magnetotellurics (PAMT), that uses a lighter AMT field system and (owing to the disregard of signals at frequencies of less than 10 Hz) shortened data acquisition time. PAMT uses three magnetometers pre-mounted on a rigid frame to measure magnetic fields and steel electrodes to measure electric fields. Field tests proved that the system is stable enough to measure AMT fields in the given frequency range. A PAMT test measurement was carried out on Gotland, Sweden along a 3.5 km profile to study the ground conductivity and to map shallow Silurian marlstone and limestone formations, deeper Silurian, Ordovician and Cambrian sedimentary structures and crystalline basement. RMT data collected along a coincident profile and regional airborne very low frequency (VLF) data support the interpretation of our PAMT data. While only the RMT and VLF data constrain a shallow ( 20-50 m deep) transition between Silurian conductive (< 30 Ωm resistivity) marlstone and resistive (> 1000 Ωm resistivity) limestone, the single-method inversion models of both the PAMT and the RMT data show a transition into a conductive layer of 3 to 30 Ωm resistivity at 80 m depth suggesting the compatibility of the two data sets. This conductive layer is interpreted as saltwater saturated succession of Silurian, Ordovician and Cambrian sedimentary units. Towards the lower boundary of this succession (at 600 m depth according to boreholes), only the PAMT data constrain the structure. As supported by modelling tests and sensitivity analysis, the PAMT data only contain a vague indication of the

Understanding the African-American Student Experience in Higher Education through a Relational Dialectics Perspective

ERIC Educational Resources Information Center

Simmons, Jake; Lowery-Hart, Russell; Wahl, Shawn T.; McBride, M. Chad

2013-01-01

In this study, we sought to understand African-American students' higher-education experiences in predominantly White universities. We utilized Baxter's relational dialectics theory to study components of focus-group discussions in order to understand the discourse and meaning-making process of participants. Our findings provide insight into the…

Joint Audio-Magnetotelluric and Passive Seismic Imaging of the Cerdanya Basin

NASA Astrophysics Data System (ADS)

Gabàs, A.; Macau, A.; Benjumea, B.; Queralt, P.; Ledo, J.; Figueras, S.; Marcuello, A.

2016-09-01

The structure of Cerdanya Basin (north-east of Iberian Peninsula) is partly known from geological cross sections, geological maps and vintage geophysical data. However, these data do not have the necessary resolution to characterize some parts of Cerdanya Basin such as the thickness of soft soil, geometry of bedrock or geometry of geological units and associated faults. For all these reasons, the main objective of this work is to improve this deficiency carrying out a detailed study in this Neogene basin applying jointly the combination of passive seismic methods ( H/V spectral ratio and seismic array) and electromagnetic methods (audio-magnetotelluric and magnetotelluric method). The passive seismic techniques provide valuable information of geometry of basement along the profile. The maximum depth is located near Alp village with a bedrock depth of 500 m. The bedrock is located in surface at both sites of profile. The Neogene sediments present a shear-wave velocity between 400 and 1000 m/s, and the bedrock basement presents a shear-wave velocity values between 1700 and 2200 m/s. These results are used as a priori information to create a 2D resistivity initial model which constraints the inversion process of electromagnetic data. We have obtained a 2D resistivity model which is characterized by (1) a heterogeneous conductivity zone (<40 Ohm m) that corresponds to shallow part of the model up to 500 m depth in the centre of the profile. These values have been associated with Quaternary and Neogene sediments formed by silts, clays, conglomerates, sandstones and gravels, and (2) a deeper resistive zone (1000-3000 Ohm m) interpreted as Palaeozoic basement (sandstones, limestones and slates at NW and conglomerates and microconglomerates at SE). The resistive zone is truncated by a discontinuity at the south-east of the profile which is interpreted as the Alp-La Tet Fault. This discontinuity is represented by a more conductive zone (600 Ohm m approx.) and is explained

Magnetotelluric Data, Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackie M. Williams; Jay A. Sampson; Brian D. Rodriguez

2006-11-03

The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. From 1951 to 1992, 828 underground nuclear tests were conducted at the Nevada Test Site northwest of Las Vegas. Most of these tests were conducted hundreds of feet above the ground-water table; however, more than 200 of the tests were near or within the water table. This underground testing was limited to specific areas ofmore » the Nevada Test Site, including Pahute Mesa, Rainier Mesa/Shoshone Mountain, Frenchman Flat, and Yucca Flat. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology, and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (Bechtel Nevada, 2006). During 2005, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data from twenty-six magnetotelluric (MT) and audio-magnetotelluric (AMT) sites at the Nevada Test Site. The 2005 data stations were located on and near Rainier Mesa and Shoshone Mountain to assist in characterizing the pre-Tertiary geology in those areas. These new stations extend the area of the hydrogeologic study previously conducted in Yucca Flat. This work will help refine what is known about the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU – late Devonian to Mississippian-age siliciclastic rocks assigned to the Eleana Formation and Chainman Shale) from the Yucca Flat area and west

Geophysical Studies of Irish Granites Using Magnetotelluric and Gravity Data

NASA Astrophysics Data System (ADS)

Farrell, T. F.; Muller, M. R.; Rath, V.; Feely, M.; Hogg, C.

2014-12-01

We present results of on-going geophysical studies of Caledonian radiothermal granite bodies in Ireland, which are being undertaken to investigate the volumetric depth extent and structural features of these granites. During three field seasons, magnetotelluric (MT) and audio-magnetotelluric (AMT) data were acquired at 156 sites targeting three separate granite bodies. These studies will contribute to a crustal-scale investigation of the geothermal energy potential of the granites and their contribution to the thermal field of the Irish crust. Across the calc-alkaline Galway granite, located on the Irish west coast, MT and AMT data were acquired at 75 sites distributed in a grid. Preliminary 3D inversion reveals the presence of a resistor, thickest beneath the central block of the granite where it extends to depths of 11 - 12 km. The greater depth of the resistor beneath the central block is in contrast to previous thinking that proposed the central block granites to have shallower depth extent than those of the western block, based on Bouguer anomaly maps of the area in which the western block exhibited a more pronounced negative Bouguer anomaly than the central block. At the S-type Leinster granite, in eastern Ireland and to the south of Dublin, MT and AMT data were acquired along two profiles (LGN - 27 sites and LGS - 32 sites). Preliminary 1D inversions of AMT data along profile LGN show the Northern Units of the Leinster granite to extend to a depth of 4.5 km and the Lugnaquilla pluton extending to 2.5 km depth. MT and AMT data were acquired at 22 sites along a profile across the buried Kentstown granite, 35 km to the NW of Dublin. The Kentstown granite was intersected by two mineral exploration boreholes at depths of 492 m and 663 m. Preliminary 2D inversions do not yet satisfactorily resolve the top of the buried granite. Inversion of MT and AMT data is continuing, with the electrical conductivity structures revealed by these inversions being used to

How Religious Engagement Shapes the College Experience of African American Christian Males at a Predominantly White Institution: A Phenomenological Approach

ERIC Educational Resources Information Center

Rice, Stephen J.

2012-01-01

Understanding the different aspects of the college experience of African American males in a predominantly White institution is an important topic for researchers. This focus directly responds to the despairing statistics surrounding collegiate African American males, who often show lower graduation rates compared to other racial groups. The need…

Interpretation of shallow electrical features from electromagnetic and magnetotelluric surveys at Mount Hood, Oregon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldstein, N.E.; Mozley, E.; Wilt, M.

1982-04-10

A magnetotelluric survey was conducted at accessible locations around Mount Hood, Oregon. Thirty-eight tensor magnetotelluric (MT) and remote telluric stations were set up in clusters around the volcano except for the northwest quadrant, a wilderness area. Because of limited access, station locations were restricted to elevations below 1829 m. On the basis of the MT results, three areas were later investigated in more detail using a large-moment, controlled-source electromagnetic (EM) system. One-dimensional interpretations of EM and MT data on the northeast flank of the mountain near the Cloud Cap eruptive center and on the south flank near Timberline Lodge showmore » a similar subsurface resistivity pattern: a resistive surface layer 400--700 m thick, underlain by a conductive layer with variable thickness and resistivity of <20 ohm m. It is speculated that the surface layer consists of volcanics partially saturated with cold meteoric water. The underlying conductive zone is presumed to be volcanics saturated with water heated within the region of the central conduit and, possibly, at the Cloud Cap side vent. This hypothesis is supported by the existence of warm springs at the base of the mountain, most notably Swim Warm Springs on the south flank, and by several geothermal test wells, one of which penetrates the conductor south of Timberline Lodge. The mT data typically gave a shallower depth to the conductive zone than did the Em data. On the other hand, MT was better for resolving the thickness of the conductive layer and deeper structure. The MT data show evidence for a moderately conductive north-south structure on the south flank below the Timberline Lodge and for a broad zone of late Tertiary intrusives concealed on the southeast flank.« less

An audio-magnetotelluric investigation in Terceira Island (Azores)

NASA Astrophysics Data System (ADS)

Monteiro Santos, Fernando A.; Trota, António; Soares, António; Luzio, Rafael; Lourenço, Nuno; Matos, Liliana; Almeida, Eugénio; Gaspar, João L.; Miranda, Jorge M.

2006-08-01

Ten audio-magnetotelluric soundings have been carried out along a profile crossing the Serra do Cume caldera in the eastern part of the Terceira Island (Azores). The main objectives of this investigation were to detect geoelectrical features related with tectonic structures and to characterize regional hydrological and hydrothermal aspects mainly those related to geothermal fluid dynamics. Three-dimensional numerical investigation showed that the data acquired at periods shorter than 1 s are not significantly affected by ocean effect. The data was analysed using the Smith's decomposition method in order to investigate possible distortions caused by superficial structures and to estimate a global regional strike. The results suggest that in general the soundings were not distorted. A regional N55°W strike was chosen for the two-dimensional data inversion. The low-resistivity zones (10-30 ohm-m) displayed in the central part of the 2-D geoelectrical model have been interpreted as caused by hydrothermal circulation. The low-resistivity anomalies at the ends of the profile might be attributed to alteration zones with interaction of seawater intrusion. High-resistivity (> 300 ohm-m) values have been related with less permeable zones in the SW of Cinco Picos and Guilherme Moniz caldera walls.

A time-frequency analysis method to obtain stable estimates of magnetotelluric response function based on Hilbert-Huang transform

NASA Astrophysics Data System (ADS)

Cai, Jianhua

2017-05-01

The time-frequency analysis method represents signal as a function of time and frequency, and it is considered a powerful tool for handling arbitrary non-stationary time series by using instantaneous frequency and instantaneous amplitude. It also provides a possible alternative to the analysis of the non-stationary magnetotelluric (MT) signal. Based on the Hilbert-Huang transform (HHT), a time-frequency analysis method is proposed to obtain stable estimates of the magnetotelluric response function. In contrast to conventional methods, the response function estimation is performed in the time-frequency domain using instantaneous spectra rather than in the frequency domain, which allows for imaging the response parameter content as a function of time and frequency. The theory of the method is presented and the mathematical model and calculation procedure, which are used to estimate response function based on HHT time-frequency spectrum, are discussed. To evaluate the results, response function estimates are compared with estimates from a standard MT data processing method based on the Fourier transform. All results show that apparent resistivities and phases, which are calculated from the HHT time-frequency method, are generally more stable and reliable than those determined from the simple Fourier analysis. The proposed method overcomes the drawbacks of the traditional Fourier methods, and the resulting parameter minimises the estimation bias caused by the non-stationary characteristics of the MT data.

Missed Opportunities: Examining the Literacy Experiences of African American Students Displaced by Hurricane Katrina

ERIC Educational Resources Information Center

Pollard, Tamica McClarty

2011-01-01

The purpose of this study was to examine how five African American middle school students, who were displaced by Hurricane Katrina represent their literacy experiences before, during, and after their displacement. Specifically, the two research questions were: (a) What are the stories that these middle school students tell about their lives,…

The challenge of linguistic and cultural diversity: Does length of experience affect South African speech-language therapists' management of children with language impairment?

PubMed

Southwood, Frenette; Van Dulm, Ondene

2015-02-10

South African speech-language therapists (SLTs) currently do not reflect the country's linguistic and cultural diversity. The question arises as to who might be better equipped currently to provide services to multilingual populations: SLTs with more clinical experience in such contexts, or recently trained SLTs who are themselves linguistically and culturally diverse and whose training programmes deliberately focused on multilingualism and multiculturalism? To investigate whether length of clinical experience influenced: number of bilingual children treated, languages spoken by these children, languages in which assessment and remediation can be offered, assessment instrument(s) favoured, and languages in which therapy material is required. From questionnaires completed by 243 Health Professions Council of South Africa (HPCSA)-registered SLTs who treat children with language problems, two groups were drawn:71 more experienced (ME) respondents (20+ years of experience) and 79 less experienced (LE) respondents (maximum 5 years of experience). The groups did not differ significantly with regard to (1) number of children(monolingual or bilingual) with language difficulties seen, (2) number of respondents seeing child clients who have Afrikaans or an African language as home language, (3) number of respondents who can offer intervention in Afrikaans or English and (4) number of respondents who reported needing therapy material in Afrikaans or English. However, significantly more ME than LE respondents reported seeing first language child speakers of English, whereas significantly more LE than ME respondents could provide services, and required therapy material, in African languages. More LE than ME SLTs could offer remediation in an African language, but there were few other significant differences between the two groups. There is still an absence of appropriate assessment and remediation material for Afrikaans and African languages, but the increased number of African

The challenge of linguistic and cultural diversity: Does length of experience affect South African speech-language therapists’ management of children with language impairment?

PubMed Central

Southwood, Frenette; van Dulm, Ondene

2015-01-01

Background South African speech-language therapists (SLTs) currently do not reflect the country's linguistic and cultural diversity. The question arises as to who might be better equipped currently to provide services to multilingual populations: SLTs with more clinical experience in such contexts, or recently trained SLTs who are themselves linguistically and culturally diverse and whose training programmes deliberately focused on multilingualism and multiculturalism? Aims To investigate whether length of clinical experience influenced: number of bilingual children treated, languages spoken by these children, languages in which assessment and remediation can be offered, assessment instrument(s) favoured, and languages in which therapy material is required. Method From questionnaires completed by 243 Health Professions Council of South Africa (HPCSA)-registered SLTs who treat children with language problems, two groups were drawn: 71 more experienced (ME) respondents (20+ years of experience) and 79 less experienced (LE) respondents (maximum 5 years of experience). Results The groups did not differ significantly with regard to (1) number of children (monolingual or bilingual) with language difficulties seen, (2) number of respondents seeing child clients who have Afrikaans or an African language as home language, (3) number of respondents who can offer intervention in Afrikaans or English and (4) number of respondents who reported needing therapy material in Afrikaans or English. However, significantly more ME than LE respondents reported seeing first language child speakers of English, whereas significantly more LE than ME respondents could provide services, and required therapy material, in African languages. Conclusion More LE than ME SLTs could offer remediation in an African language, but there were few other significant differences between the two groups. There is still an absence of appropriate assessment and remediation material for Afrikaans and African

Good fit or chilly climate: An exploration of the persistence experiences of African-American women graduates of predominantly White college science programs

NASA Astrophysics Data System (ADS)

Justin-Johnson, Carolyn

This qualitative study explored the persistence experiences of African-American women science graduates of a predominantly White institution (PWI). The purpose of the study was to promote a holistic understanding---complementing findings from quantitative studies---of how African-American women give meaning to their collegiate experiences. Eight recent graduates of two college science programs (biological sciences and chemistry) were selected to participate in the study because of their willingness to answer interview questions related to sensitive issues about their experiences. Data analysis included coding transcripts, creating a codebook, memo writing, and constructing a model single-case event-flow network and a conceptually clustered matrix. Participants in the study shared a common viewpoint about the unwelcoming and non-supportive environment that they navigated to persist to graduation. Specifically, they identified a combination of (1) non-supportive mechanisms that could have been deterrents to their persistence and (2) supportive mechanisms that were instrumental in helping them to cope with negative experiences on campus that made them feel "uncomfortable" and alienated as one of the few African-American women in science classes. Findings in this study suggest that it is imperative for predominantly White institutions to organize reform efforts around creating more welcoming and inclusive campus environments, especially in the sciences, for African-American women---thus promoting satisfying college experiences that lead to degree and career attainment.

Two Dimensional Finite Element Based Magnetotelluric Inversion using Singular Value Decomposition Method on Transverse Electric Mode

NASA Astrophysics Data System (ADS)

Tjong, Tiffany; Yihaa’ Roodhiyah, Lisa; Nurhasan; Sutarno, Doddy

2018-04-01

In this work, an inversion scheme was performed using a vector finite element (VFE) based 2-D magnetotelluric (MT) forward modelling. We use an inversion scheme with Singular value decomposition (SVD) method toimprove the accuracy of MT inversion.The inversion scheme was applied to transverse electric (TE) mode of MT. SVD method was used in this inversion to decompose the Jacobian matrices. Singular values which obtained from the decomposition process were analyzed. This enabled us to determine the importance of data and therefore to define a threshold for truncation process. The truncation of singular value in inversion processcould improve the resulted model.

Impact of regulatory requirements on medicine registration in African countries – perceptions and experiences of pharmaceutical companies in South Africa

PubMed Central

Narsai, Kirti; Williams, Abeda; Mantel-Teeuwisse, Aukje Kaija

2012-01-01

Objective: Access to medicines has long been and remains a challenge in African countries. The impact of medicines registration policies in these countries poses a challenge for pharmaceutical companies wanting to register medicines in these countries. The recent AMRHI (African Medicines Registration Harmonisation Initiative) has increased the focus on the need for harmonisation. Medicines registration regulations differ across African countries. Anecdotal evidence, based on the experience of pharmaceutical companies on progress towards harmonisation is somewhat different, i.e. that country specific requirements were a barrier to the registration of medicines. The objective of this study was therefore to determine the nature and extent of regulatory hurdles experienced by pharmaceutical companies who wish to register and supply medicines to African countries. Methods: This cross-sectional descriptive pilot study was conducted across pharmaceutical companies, both local and multinational. These companies were based in South Africa and were also members of Pharmaceutical Industry Association of South Africa (PIASA). The pharmaceutical companies supply both the private and public sectors. An online survey was developed using Survey Monkey. Survey questions focused on the following strands: nature and level of current supply of medicines to African countries by companies, general regulatory requirements, region specific questions and country specific questions across four regional economic communities in Africa, namely; Southern African Development Community (SADC), East African Community (EAC), Economic Community of the West African States (ECOWAS) and Economic Community of Central African States (ECCAS). Results: A total of 33 responses were received to the questionnaire of which 26 respondents were from the PIASA Regulatory working group and 7 were from the PIASA Export working group.It was noted that since most of the regulatory authorities in Africa are resource

Preliminary magnetotelluric results across Dalma Volcanics, Eastern India: Inferences on metallogeny

NASA Astrophysics Data System (ADS)

Maurya, Ved P.; Shalivahan; Bhattacharya, B. B.; Adhikari, P. K.; Das, L. K.

2015-04-01

The regional magnetotelluric (MT) survey across Dalma Volcanics (DVs) in North Singhbhum Mobile Belt (NSMB) was carried out to obtain the conductivity model and to understand the metallogeny. The structure in general is 2-D and the average strike is N60°W. 2-D inversions using TE + TM and TE + TM + Tzy were carried out. Both inversions derived models with similar features but with modified shape. The TE + TM + Tzy inversion brings up two conducting zones enveloping three anomalous conducting bodies. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis of the samples collected from 8 to 10 m pit from different stratigraphic units of Dalma volcano-sedimentary belt indicates the presence of gold, silver, uranium and copper. The study area is a felsic dominated rifted margin and shows high conductivity contrast along with high gravity, magnetic and significant radiometric anomaly. Thus, the conducting zones indicate the presence of volcanogenic massive sulfide (VMS) or volcano hosted gold deposit (Au-VMS) in NSMB.

Experiences of the Single Low-Income African American Mothers in Their Maternal Protective Role

ERIC Educational Resources Information Center

Ivory, Shirley Clark

2010-01-01

This study was an IRB approved qualitative investigation of experiences of the single low-income African American mothers in their maternal protective role. In-depth interviews and a focus group were conducted with 13 single-low income women who met the criteria for participation in the study, in an effort to understand the social context in which…

Coparenting experiences in African American families: an examination of single mothers and their nonmarital coparents.

PubMed

Gonzalez, Michelle; Jones, Deborah; Parent, Justin

2014-03-01

African American youth from single-mother homes continue to be overrepresented in statistics on risk behavior and delinquency, a trend that many be attributed to father-absence, socioeconomic disadvantage, and compromises in parenting more typical of single than two-parent families. Yet, this risk-focused perspective ignores a long-standing strength of the African American community, the involvement and potential protective impact of extended family members in childrearing. This study describes the experiences of 95 African American single mothers and their nonmarital coparents who participated in a study of African American single-mother families with an 11-16-year-old child. Specifically, the study examines: (a) the extent to which nonmarital coparents are involved in childrearing; (b) the relative levels of risk (i.e., depression, mother-coparent conflict) and protective (i.e., parenting) associated with maternal and coparent involvement; and (c) how similarly and/or differently coparent and mother variables operate with regard to youth externalizing problems. Findings reveal that a range of family members and other adults actively participate in childrearing in African American single-mother families, coparents do not differ from mothers on certain study variables (i.e., depression and mother-coparent conflict) but do for others (parenting), and coparent involvement is associated with youth adjustment in ways that are similar to our more established understanding of maternal involvement. The potential clinical implications of the findings are discussed and future research directions are highlighted. © 2014 FPI, Inc.

Magnetotelluric Investigations of the Yellowstone Caldera: Understanding the Emplacement of Crustal Magma Bodies

NASA Astrophysics Data System (ADS)

Gurrola, R. M.; Neal, B. A.; Bennington, N. L.; Cronin, R.; Fry, B.; Hart, L.; Imamura, N.; Kelbert, A.; Bowles-martinez, E.; Miller, D. J.; Scholz, K. J.; Schultz, A.

2017-12-01

Wideband magnetotellurics (MT) presents an ideal method for imaging conductive shallow magma bodies associated with contemporary Yellowstone-Snake River Plain (YSRP) magmatism. Particularly, how do these magma bodies accumulate in the mid to upper crust underlying the Yellowstone Caldera, and furthermore, what role do hydrothermal fluids play in their ascent? During the summer 2017 field season, two field teams from Oregon State University and the University of Wisconsin-Madison installed forty-four wideband MT stations within and around the caldera, and using data slated for joint 3-D inversion with existing seismic data, two 2-D vertical conductivity sections of the crust and upper mantle were constructed. These models, in turn, provide preliminary insight into the emplacement of crustal magma bodies and hydrothermal processes in the YSRP region.

Educational Change in Post-Conflict Contexts: Reflections on the South African Experience 20 Years Later

ERIC Educational Resources Information Center

Christie, Pam

2016-01-01

Reflecting on South African experience, this paper develops an analytical framework using the work of Henri Lefebvre and Nancy Fraser to understand why socially just arrangements may be so difficult to achieve in post-conflict reconstruction. The paper uses Lefebvre's analytic to trace three sets of entangled practices…

"I Want to Do the Right Thing but What Is It?": White Teachers' Experiences with African American Students

ERIC Educational Resources Information Center

Henfield, Malik S.; Washington, Ahmad R.

2012-01-01

This qualitative study examines 26 White middle school teachers' perceptions of their experiences in a predominantly White middle school with a growing African American student population. Utilizing in-depth focus group interviews, teachers elaborated on their experiences with navigating racial, ethnic and cultural boundaries as they attempted to…

Infected Lives: Lived Experiences of Young African American HIV-Positive Women.

PubMed

Peltzer, Jill N; Domian, Elaine W; Teel, Cynthia S

2016-02-01

This hermeneutic phenomenological study explored the lived experiences of young African American HIV-infected women. Eleven women between the ages of 21 and 35 participated. One pattern, Infected Lives, and three themes--Living Alone With HIV, Living With Unresolved Conflicts, and Living With Multiple Layers of Betrayal--emerged. The pattern and themes portray the very complex and challenging experiences faced by these young women living with HIV infection. They have experienced isolation, abandonment, betrayal, and discrimination in their interpersonal and social systems. They often dealt with conflicts of hope and anguish in the relationships with their children, and portraying strength, while feeling fragile. These complexities negatively influence the ability to fully engage in self-care activities. Implications for future research include further investigation about the experiences of psychological distress experienced post-diagnosis, development and evaluation of holistic nursing interventions, and evaluative research on mass media educational campaigns to reduce HIV-related stigma. © The Author(s) 2014.

Efficient computational methods for electromagnetic imaging with applications to 3D magnetotellurics

NASA Astrophysics Data System (ADS)

Kordy, Michal Adam

The motivation for this work is the forward and inverse problem for magnetotellurics, a frequency domain electromagnetic remote-sensing geophysical method used in mineral, geothermal, and groundwater exploration. The dissertation consists of four papers. In the first paper, we prove the existence and uniqueness of a representation of any vector field in H(curl) by a vector lying in H(curl) and H(div). It allows us to represent electric or magnetic fields by another vector field, for which nodal finite element approximation may be used in the case of non-constant electromagnetic properties. With this approach, the system matrix does not become ill-posed for low-frequency. In the second paper, we consider hexahedral finite element approximation of an electric field for the magnetotelluric forward problem. The near-null space of the system matrix for low frequencies makes the numerical solution unstable in the air. We show that the proper solution may obtained by applying a correction on the null space of the curl. It is done by solving a Poisson equation using discrete Helmholtz decomposition. We parallelize the forward code on multicore workstation with large RAM. In the next paper, we use the forward code in the inversion. Regularization of the inversion is done by using the second norm of the logarithm of conductivity. The data space Gauss-Newton approach allows for significant savings in memory and computational time. We show the efficiency of the method by considering a number of synthetic inversions and we apply it to real data collected in Cascade Mountains. The last paper considers a cross-frequency interpolation of the forward response as well as the Jacobian. We consider Pade approximation through model order reduction and rational Krylov subspace. The interpolating frequencies are chosen adaptively in order to minimize the maximum error of interpolation. Two error indicator functions are compared. We prove a theorem of almost always lucky failure in the

Conservation lessons from large-mammal manipulations in East African savannas: the KLEE, UHURU, and GLADE experiments

USDA-ARS?s Scientific Manuscript database

African savannas support an iconic fauna, but they are undergoing large-scale population declines and extinctions of large (>5 kg) mammals. Long-term, controlled, replicated experiments that explore the consequences of this defaunation (and its replacement with livestock) are rare. The Mpala Researc...

Ring of Silence: African American Women's Experiences Related to Their Breasts and Breast Cancer Screening

ERIC Educational Resources Information Center

Thomas, Eileen

2006-01-01

The purpose of this study was to explore women's memories and feelings concerning their breasts and breast cancer screening experiences in relation to their current breast cancer screening behaviors. Twelve African American women shared stories that were generated in written narratives and individual interviews. Two core themes emerged from the…

A Phenomenological Examination of Middle School African American Adolescent Men's Experiences with Professional School Counselors

ERIC Educational Resources Information Center

Washington, Ahmad Rashad

2013-01-01

This qualitative study was conducted with a sample of five (5) middle school African American adolescent men from two different schools in the same school district to explore their perceptions of and experiences with their professional school counselors. Phenomenological qualitative methodology was used to complete this study. To gather research…

African-American School Counselors in Majority School Districts: A Qualitative Perspective of Their Lived Experiences

ERIC Educational Resources Information Center

Wingate, Crystal Nicole

2011-01-01

This dissertation will focus on the lived experiences of African-American school counselors in majority school districts and the lack of retention among this population. The lack of retention and representation of ethnic minorities in the workforce has been the subject of much discussion throughout the United States (Ingersoll, 2004). The…

Understanding Experiences of Diabetes Medications Among African Americans Living With Type 2 Diabetes.

PubMed

Bockwoldt, Denise; Staffileno, Beth A; Coke, Lola; Hamilton, Rebekah; Fogg, Lou; Calvin, Donna; Quinn, Lauretta

2017-07-01

African American (AA) adults are disproportionally affected by type 2 diabetes and are diagnosed at an earlier age, but are less adherent to diabetes medications compared with the general population. This qualitative study sought to describe the experiences of taking diabetes medications among midlife AA men and women with type 2 diabetes and to identify factors that influence these experiences. Fifteen AAs completed semistructured interviews. Using the Roy adaptation model, thematic analysis coded for both adaptive and ineffective experiences. Adaptive experiences included self-confidence in one's ability to control diabetes, a belief in the value of diabetes medication, assuming responsibility for one's health, developing a routine for taking medication, and positive relationships with the care team. Ineffective experiences for medication taking included: feeling powerless over diabetes, self-blame, and fear. One's self-concept as a person with diabetes, as well as assuming the role of "medication taker," were prominent themes.

Empirical investigation into depth-resolution of Magnetotelluric data

NASA Astrophysics Data System (ADS)

Piana Agostinetti, N.; Ogaya, X.

2017-12-01

We investigate the depth-resolution of MT data comparing reconstructed 1D resistivity profiles with measured resistivity and lithostratigraphy from borehole data. Inversion of MT data has been widely used to reconstruct the 1D fine-layered resistivity structure beneath an isolated Magnetotelluric (MT) station. Uncorrelated noise is generally assumed to be associated to MT data. However, wrong assumptions on error statistics have been proved to strongly bias the results obtained in geophysical inversions. In particular the number of resolved layers at depth strongly depends on error statistics. In this study, we applied a trans-dimensional McMC algorithm for reconstructing the 1D resistivity profile near-by the location of a 1500 m-deep borehole, using MT data. We resolve the MT inverse problem imposing different models for the error statistics associated to the MT data. Following a Hierachical Bayes' approach, we also inverted for the hyper-parameters associated to each error statistics model. Preliminary results indicate that assuming un-correlated noise leads to a number of resolved layers larger than expected from the retrieved lithostratigraphy. Moreover, comparing the inversion of synthetic resistivity data obtained from the "true" resistivity stratification measured along the borehole shows that a consistent number of resistivity layers can be obtained using a Gaussian model for the error statistics, with substantial correlation length.

Illuminating the Experiences of African-American Nursing Faculty Seeking Employment in Higher Education in Nursing

ERIC Educational Resources Information Center

Loyd, Vanessa

2015-01-01

This study explored and described the experience of female African-American nursing faculty seeking employment in higher education in nursing. The lack of diversity in the nursing workforce has been attributed as a major underlying cause of disparity in healthcare in the United States. The importance of increasing the number of minority nursing…

Investigating Instructional Practices of an African American Male Mathematics Teacher with Underachieving African American Male Students

ERIC Educational Resources Information Center

Muhammad, Rhonda K.

2012-01-01

This qualitative study examined the instructional practices of an experienced African American mathematics teacher to determine his perceived capabilities in augmenting academic proficiency for his African American male students. Provided in this descriptive case study are the lived experiences of an African American male teacher working to move…

Influence of social experiences in shaping perceptions of the Ebola virus among African residents of Hong Kong during the 2014 outbreak: a qualitative study.

PubMed

Siu, Judy Yuen-man

2015-10-05

The outbreak of Ebola virus disease (EVD) in Africa in 2014 attracted worldwide attention. Because of the high mortality rate, marginalised social groups are vulnerable to disease-associated stigmatisation and discrimination, according to the literature. In Hong Kong, ethnic minorities such as Africans are often disadvantaged groups because of their low position in the social hierarchy. In 2011, approximately 1700 Africans were residing in Hong Kong. Their overseas experiences during the EVD outbreak were not well documented. Therefore, this study investigated the EVD-associated stigmatisation experiences of African residents of Hong Kong with chronic illnesses, and how these experiences shaped their perceptions of EVD. A qualitative design with 30 in-depth semistructured interviews was conducted with chronically ill African residents of Hong Kong. The interview data showed that the sampled Africans often experienced stigmatisation in their workplaces and in the community during the EVD outbreak. Their experiences of EVD-associated stigma were correlated to the embedded social and cultural values regarding ethnic minorities in Hong Kong. These experiences of being stigmatised shaped the perceptions of the Africans of EVD, leading them to view EVD as shameful and horrifying. They also perceived EVD as retribution and was introduced by Westerners. The participants' perceptions of EVD influenced their responses to and behaviour towards EVD, which may have posed potential threats to Hong Kong's public health. The EVD outbreak was not the only cause of the participants' stigmatisation; rather, their EVD-associated experiences were a continuation and manifestation of the embedded social and cultural values regarding ethnic minorities in Hong Kong. The experiences of being stigmatised shaped the participants' perceptions of EVD. Because of their marginalised social position and isolation from the main community, the participants had extremely limited access to reliable

A Hermeneutic Phenomenological Study of the Experiences of Female African American Undergraduate Engineering Students at a Predominantly White and an Historically Black Institution

ERIC Educational Resources Information Center

Frillman, Sharron Ann

2011-01-01

This phenomenological study examined the experiences of twelve female African Americans enrolled as fulltime undergraduate engineering students at North Carolina Agricultural and Technical State University, an historically Black university, and seven female African Americans enrolled as undergraduate engineering students at Purdue University in…

A magnetotelluric study of the sensitivity of an area to seismoelectric signals

USGS Publications Warehouse

Balasis, G.; Bedrosian, P.A.; Eftaxias, K.

2005-01-01

During recent years, efforts at better understanding the physical properties of precursory ultra-low frequency pre-seismic electric signals (SES) have been intensified. Experiments show that SES cannot be observed at all points of the Earth's surface but only at certain so-called sensitive sites. Moreover, a sensitive site is capable of collecting SES from only a restricted number of seismic areas (selectivity effect). Tberefore the installation of a permanent station appropriate for SES collection should necessarily be preceded by a pilot study over a broad area and for a long duration. In short, a number of temporary stations are installed and, after the occurrence of several significant earthquakes (EQs) from a given seismic area, the most appropriate (if any) of these temporary stations, in the sense that they happen to collect SES, can be selected as permanent. Such a long experiment constitutes a serious disadvantage in identifying a site as SES sensitive. However, the SES sensitivity of a site should be related to the geoelectric structure of the area that hosts the site as well as the regional geoelectric structure between the station and the seismic focal area. Thus, knowledge of the local and regional geoelectric structure can dramatically reduce the time involved in identifying SES sites. hi this paper the magnetotelluric method is used to investigate the conductivity structure of an area where a permanent SES station is in operation. Although general conclusions cannot be drawn, the area surrounding an SES site near Ioannina, Greece is characterized by: (1) major faults in the vicinity; (2) highly resistive structure flanked by abrupt conductivity contrasts associated with large-scale geologic contacts, and (3) local inhomogeneities in conductivity structure. The above results are consistent with the fact that electric field amplitudes from remotely-generated signals should be appreciably stronger at such sites when compared to neighboring sites

Underserved, Underrepresented, Unprepared: Experiences of African American Females in Community College with Barriers to Academic Success

ERIC Educational Resources Information Center

Jobe, LaWanda D.

2013-01-01

African American women are enrolling and returning to college in large numbers across many community college campuses, especially those women who would be characterized as nontraditional students. This qualitative study examined and analyzed the experiences, stresses, and coping mechanisms of first generation, nontraditional, single parent,…

A Study of the Experience of Female African-American Seventh Graders in a Science, Technology, Engineering, and Math (STEM) Afterschool Program

NASA Astrophysics Data System (ADS)

Hinds, Beverley Fiona

The purpose of this qualitative study was to determine what inspires or leads seventh-grade African-American girls toward an interest in STEM, to characterize and describe the context of an out-of-school STEM learning environment, explore the impact on the seventh- grade African-American girls who participated in the program as it relates to individual STEM identity, and identify personal and academic experiences of seventh-grade African- American girls that contribute to the discouragement or pursuit of science and math-related academic pathways and careers. Notable findings in this study included the following: 1. Participants were interested in STEM and able to identify both external and internal influences that supported their involvement and interest in STEM activities. External influences expanded and elevated exposure to STEM experiences. 2. The MJS program provided an opportunity for participants to overcome challenges related to science and math knowledge and skills in school. 3. The MJS program increased levels of interest in STEM for the participants. 4. All participants increased their capacity to demonstrate increased knowledge in STEM content as a result of the learning experiences within the MJS program, and participants transferred this knowledge to experiences outside of the program including school. 5. The STEM learning environment provided multiple opportunities for participants to meet high expectation and access to engaging activities within a supportive, well-managed setting. 6. The MJS program participants demonstrated behaviors related to building a STEM identity through the components described by Carlone and Johnson (2007), including recognition-internal and external acknowledgement of being a STEM person; competence-demonstrating an understanding of STEM content; and performance-publically exhibiting STEM knowledge and skills. The findings in this study suggested that African-American seventh-grade girls interested in STEM are inspired

Interpretation of shallow electrical features from electromagnetic and magnetotelluric surveys at Mount Hood, Oregon

NASA Astrophysics Data System (ADS)

Goldstein, N. E.; Mozley, E.; Wilt, M.

1982-04-01

A magnetotelluric survey, with a reference magnetometer for noise cancellation, was conducted at accessible locations around Mount Hood, Oregon. Thirty-eight tensor magnetotelluric (MT) and remote telluric stations were set up in clusters around the volcano except for the northwest quadrant, a wilderness area. Because of limited access, station locations were restricted to elevations below 1829 m, or no closer than 5 km from the 3424-m summit. On the basis of the MT results, three areas were later investigated in more detail using a large-moment, controlled-source electromagnetic (EM) system developed at Lawrence Berkeley Laboratory and the University of California at Berkeley. One-dimensional interpretations of EM and MT data on the northeast flank of the mountain near the Cloud Cap eruptive center and on the south flank near Timberline Lodge show a similar subsurface resistivity pattern: a resistive surface layer 400-700 m thick, underlain by a conductive layer with variable thickness and resistivity of <20 ohm m. It is speculated that the surface layer consists of volcanics partially saturated with cold meteoric water. The underlying conductive zone is presumed to be volcanics saturated with water heated within the region of the central conduit and, possibly, at the Cloud Cap side vent. This hypothesis is supported by the existence of warm springs at the base of the mountain, most notably Swim Warm Springs on the south flank, and by several geothermal test wells, one of which penetrates the conductor south of Timberline Lodge. The MT data typically gave a shallower depth to the conductive zone than did the EM data. This is attributed, in part, to the error inherent in one-dimensional MT interpretations of geologically or topographically complex areas. On the other hand, MT was better for resolving the thickness of the conductive layer and deeper structure. The MT data show evidence for a moderately conductive north-south structure on the south flank below the

INTERPRETATION OF SHALLOW ELECTRICAL FEATURES FROM ELECTROMAGNETIC AND MAGNETOTELLURIC SURVEYS AT MOUNT HOOD, OREGON

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilt, M.; Goldstein, N.E.; Mozley, E.

1981-04-01

A magnetotelluric survey, with a reference magnetometer for noise cancellation, was conducted at accessible locations around Mount Hood, Oregon. Thirty-eight tensor magnetotelluric (MT) and remote telluric stations were set up in clusters around the volcano except for the northwest quadrant, a wilderness area. Because of limited access, station locations were restricted to elevations below 1829 m, or no closer than 5 km from the 3424-m summit. On the basis of the MT results, three areas were later investigated in more detail using a large-moment, controlled-source electromagnetic (EM) system developed at Lawrence Berkeley Laboratory and the University of California at Berkeley.more » One-dimensional interpretations of EM and MT data on the northeast flank of the mountain near the Cloud Cap eruptive center and on the south flank near Timberline Lodge show a similar subsurface resistivity pattern: a resistive surface layer 400-700 m thick, underlain by a conductive layer with variable thickness and resistivity of <20 ohm m. It is speculated that the surface layer consists of volcanics partially saturated with cold meteoric water. The underlying conductive zone is presumed to be volcanics saturated with water heated within the region of the central conduit and, possibly, at the Cloud Cap side vent. This hypothesis is supported by the existence of warm springs at the base of the mountain, most notably Swim Warm Springs on the south flank, and by several geothermal test wells, one of which penetrates the conductor south of Timberline Lodge. The MT data typically gave a shallower depth to the conductive zone than did the EM data. This is attributed, in part, to the error inherent in one-dimensional MT interpretations of geologically or topographically complex areas. On the other hand, MT was better for resolving the thickness of the conductive layer and deeper structure. The MT data show evidence for a moderately conductive north-south structure on the south flank

Magnetotelluric measurements across the southern Barberton greenstone belt, South Africa: data improving strategies and 2-D inversion results

NASA Astrophysics Data System (ADS)

Kutter, S.; Chen, X.; Weckmann, U.

2011-12-01

Magnetotelluric (MT) measurements in areas with electromagnetic (EM) noise sources such as electric fences, power and railway lines pose severe challenges to the standard processing procedures. In order to significantly improve the data quality advanced filtering and processing techniques need to be applied. The presented 5-component MT data set from two field campaigns in 2009 and 2010 in the Barberton/Badplaas area, South Africa, was acquired within the framework of the German-South African geo-scientific research initiative Inkaba yeAfrica. Approximately 200 MT sites aligned along six profiles provide a good areal coverage of the southern part of the Barberton Greenstone Belt (BGB). Since it is one of the few remaining well-preserved geological formations from the Archean, it presents an ideal area to study the tectonic evolution and the role of plate tectonics on Early Earth. Comparing the electric properties, the surrounding high and low grade metamorphic rocks are characteristically resistive whereas mineralized shear zones are possible areas of higher electrical conductivity. Mapping their depth extension is a crucial step towards understanding the formation and the evolution of the BGB. Unfortunately, in the measurement area numerous noise sources were active, producing severe spikes and steps in the EM fields. These disturbances mainly affect long periods which are needed for resolving the deepest structures. The Remote Reference technique as well as two filtering techniques are applied to improve the data in different period ranges. Adjusting their parameters for each site is necessary to obtain the best possible results. The improved data set is used for two-dimensional inversion studies for the six profiles applying the RLM2DI algorithm by Rodi and Mackie (2001, implemented in WinGlink). In the models, areas with higher conductivity can be traced beneath known faults throughout the entire array along different profiles. Resistive zones seem to correlate

Coparenting Experiences in African American Families: An Examination of Single Mothers and their Non-Marital Coparents

PubMed Central

Gonzalez, Michelle; Jones, Deborah J.; Parent, Justin

2015-01-01

African American youth from single mother homes continue to be overrepresented in statistics on risk behavior and delinquency, a trend that many be attributed to father-absence, socioeconomic disadvantage, and compromises in parenting more typical of single than two-parent families. Yet, this risk-focused perspective ignores a long-standing strength of the African American community, the involvement and potential protective impact of extended family members in childrearing. This study describes the experiences of 95 African American single mothers and their non-marital coparents who participated in a study of African American single mother families with an 11 to 16 year old child. Specifically, the study examines: 1) the extent to which nonmarital coparents are involved in childrearing; 2) the relative levels of risk (i.e., depression, mother-coparent conflict) and protective (i.e., parenting) associated with maternal and coparent involvement; and 3) how similarly and/or differently coparent and mother variables operate with regard to youth externalizing problems. Findings reveal that a range of family members and other adults actively participate in childrearing in African American single mother families, coparents do not differ from mothers on certain study variables (i.e., depression and mother-coparent conflict) but do for others (parenting), and coparent involvement is associated with youth adjustment in ways that are similar to our more established understanding of maternal involvement. The potential clinical implications of the findings are discussed and future research directions are highlighted. PMID:24479612

Relationships between Discretionary Time Activities, Emotional Experiences, Delinquency and Depressive Symptoms among Urban African American Adolescents

ERIC Educational Resources Information Center

Bohnert, Amy M.; Richards, Maryse; Kohl, Krista; Randall, Edin

2009-01-01

Using the Experience Sampling Method (ESM), this cross-sectional study examined mediated and moderated associations between different types of discretionary time activities and depressive symptoms and delinquency among a sample of 246 (107 boys, 139 girls) fifth through eighth grade urban African American adolescents. More time spent in passive…

Geoelectric structure of northern Cambay rift basin from magnetotelluric data

NASA Astrophysics Data System (ADS)

Danda, Nagarjuna; Rao, C. K.; Kumar, Amit

2017-10-01

Broadband and long-period magnetotelluric data were acquired over the northern part of the Cambay rift zone along an east-west profile 200 km in length. The decomposed TE- and TM-mode data were inverted using a 2-D nonlinear conjugate gradient algorithm to obtain the lithospheric structure of the region. A highly conductive ( 1000 S) layer was identified within the Cambay rift zone and interpreted as thick Quaternary and Tertiary sediments. The crustal conductors found in the profile were due to fluid emplacement in the western part, and the presence of fluids and/or interconnected sulfides caused by metamorphic phases in the eastern part. The demarcation of the Cambay rift zone is clearly delineated with a steeply dipping fault on the western margin, whereas the eastern margin of the rift zone gently dips along the NE-SW axis, representing a half-graben structure. A highly resistive body identified outside the rift zone is interpreted as an igneous granitic intrusive complex. Moderately conductive (30-100 Ω-m) zones indicate underplating and the presence of partial melt due to plume-lithosphere interactions.[Figure not available: see fulltext.

Web-based application for inverting one-dimensional magnetotelluric data using Python

NASA Astrophysics Data System (ADS)

Suryanto, Wiwit; Irnaka, Theodosius Marwan

2016-11-01

One-dimensional modeling of magnetotelluric (MT) data has been performed using an online application on a web-based virtual private server. The application was developed with the Python language using the Django framework with HTML and CSS components. The input data, including the apparent resistivity and phase as a function of period or frequency with standard deviation, can be entered through an interactive web page that can be freely accessed at https://komputasi.geofisika.ugm.ac.id. The subsurface models, represented by resistivity as a function of depth, are iteratively improved by changing the model parameters, such as the resistivity and the layer depth, based on the observed apparent resistivity and phase data. The output of the application displayed on the screen presents resistivity as a function of depth and includes the RMS error for each iteration. Synthetic and real data were used in comparative tests of the application's performance, and it is shown that the application developed accurate subsurface resistivity models. Hence, this application can be used for practical one-dimensional modeling of MT data.

An Ambivalent Community: International African Students in Residence at a South African University

ERIC Educational Resources Information Center

Weber, Everard

2016-01-01

This is a qualitative case study of the experiences and perceptions of South African and especially international, African students living in university residences in South Africa. The concept, community, is used to interpret interview data. This community was characterised by ambivalent social relations: There was discrimination by South Africans…

AusLAMP long period magnetotellurics: progress update and new insights into Victorian geology and mineral prospectivity

NASA Astrophysics Data System (ADS)

Chopping, R. G.; Duan, J.; Czarnota, K.; Kemp, T.

2016-12-01

It is becoming generally accepted that world-class mineral deposits have a footprint on a scale of the lithosphere. For this reason, Australia has embarked on the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) to map the conductivity of the mid to lower crust and the lithospheric mantle. AusLAMP is a collaborative project between Geoscience Australia, State and Territory Geological Surveys and Universities. The project aims to collect long-period magnetotelluric data across the Australian continent on a nominal 0.5x0.5° ( 55x55 km) grid. To date, more than 450 sites have been acquired including all sites for the state of Victoria, two-thirds of sites in South Australia and Tasmania, and approximately 25 stations in Western Australia. Progress is ramping up with acquisition to turn to the state of New South Wales, the remainder of South Australia and also acquisition in northern Australia. To support this increasing acquisition activity, additional instruments have been purchased to add to those already in Australia. 3D inversion results are now available for AusLAMP Victoria. In collaboration with the National Computational Infrastructure (NCI), the 3D ModEM codes were optimised for use on the NCI's supercomputer, speeding up large-scale inversions by an order of magnitude. The results of these inversions indicate anomalously conductive lithospheric mantle associated with the central region of Victoria which contains significant mineral deposits and prospectivity, and also anomalous resistive lithosphere associated with the southern extension of the dynamically supported Australian Alps and the Newer Volcanics Province. Modelled conductivities are also consistent with mantle xenolith data from central Victoria. Within the crust, the dominant trend of the data is along elongate north-eastern corridors of conductive material. These results shed new questions on the geological history of this region and the lithospheric architecture of the

Klippen Belt, Flysch Belt and Inner Western Carpathian Paleogene Basin Relations in the Northern Slovakia by Magnetotelluric Imaging

NASA Astrophysics Data System (ADS)

Majcin, Dušan; Bezák, Vladimír; Klanica, Radek; Vozár, Ján; Pek, Josef; Bilčík, Dušan; Telecký, Josef

2018-05-01

The paper presents the interpretation of magnetotelluric measurements along the SW-NE profile near Stará Ľubovňa (Northern Slovakia). The profile passes through the Outer Carpathian Flysch Belt, Klippen Belt and ends in the Inner Western Carpathians Paleogene NW from Ružbachy horst structure. The interpretation of the older measurements from profile Mt4 was utilized and, moreover, the 3-D geoelectrical model of studied region was constructed. The magnetotelluric data interpretations verified the northern inclination of Flysch belt structures and their smaller thickness out of Klippen Belt in direction to the Carpathian electrical conductivity zone axis. We consider this as a consequence of the flower structure—more precisely the southern branch of the suture zone related to mentioned conductivity zone. Northerly from this zone the thickness of the Outer Carpathian Flysch Belt increases and the structures have inclination to the south, i.e. to the subduction zone. The contact of Flysch Belt with Klippen Belt has a fault character and it is subvertical, slightly inclined to the North. The southern boundary between Klippen Belt and Inner Western Carpathians has also fault character and is very steep. We detect the continuation of the Ružbachy horst to the NE in the basement of Inner Western Carpathian Paleogene. The structural discordance between this horst and Klippen Belt direction is a result of younger tectonic processes. According to our results the depth distribution of the pre-Tertiary basement below the Inner Western Carpathian units is non-uniform; the basement is broken to a number of partial blocks—horsts and grabens.

Biobanking in a Challenging African Environment: Unique Experience from the SIREN Project.

PubMed

Akinyemi, Rufus O; Akinwande, Kazeem; Diala, Samuel; Adeleye, Osi; Ajose, Abiodun; Issa, Kehinde; Owusu, Dorcas; Boamah, Isaac; Yahaya, Isah Suleiman; Jimoh, Abdulraheem Olayemi; Imoh, Lucius; Fakunle, Gregory; Akpalu, Albert; Sarfo, Fred; Wahab, Kolawole; Sanya, Emmanuel; Owolabi, Lukman; Obiako, Reginald; Osaigbovo, Godwin; Komolafe, Morenikeji; Fawale, Michael; Adebayo, Philip; Olowoyo, Paul; Obiabo, Yahaya; Sunmonu, Taofiki; Chukwuonye, Ijezie; Balogun, Olayemi; Adeoye, Basirat; Oladele, Florence; Olowoniyi, Peter; Adeyemi, Frederick; Lezzi, Arthur; Falayi, Ajibola Tunde; Fasanya, Michael; Ogunwale, Kolawole; Adeola, Olabisi; Olomu, Omolara; Aridegbe, Olumayowa; Laryea, Ruth; Uvere, Ezinne; Faniyan, Moyinoluwalogo; Melikam, Ezinne; Tagge, Raelle; Akpa, Onoja; Akinyemi, Joshua; Arulogun, Oyedunni; Tiwari, Hemant K; Ovbiagele, Bruce; Owolabi, Mayowa

2018-05-07

Africa was previously insufficiently represented in the emerging discipline of biobanking despite commendable early efforts. However, with the Human, Heredity, and Health in Africa (H3Africa) initiative, biorepository science has been bolstered, regional biobanks are springing up, and awareness about biobanks is growing on the continent. The Stroke Investigative Research and Educational Network (SIREN) project is a transnational, multicenter, hospital and community-based study involving over 3000 cases and 3000 controls recruited from 16 sites in Ghana and Nigeria. SIREN aims to explore and unravel the genetic and environmental factors that interact to produce the peculiar phenotypic and clinical characteristics of stroke as seen in people of African ancestry and facilitate the development of new diagnostics, therapeutics, and preventative strategies. The aim of this article is to describe our experience with the development of the procedure for collection, processing, storage, and shipment of biological samples (blood, serum, plasma, buffy coat, red cell concentrates, and DNA) and brain imaging across coordinating and participating sites within the SIREN Project. The SIREN network was initiated in 2014 with support and funding from the H3Africa Initiative. The SIREN Biobank currently has 3015 brain images, 92,950 blood fractions (serum, plasma, red cell concentrates, and buffy coat) accrued from 8450 recruited subjects, and quantified and aliquoted good-quality DNA extracts from 6150 study subjects. This represents an invaluable resource for future research with expanding genomic and trans-omic technologies. This will facilitate the involvement of indigenous African samples in cutting-edge stroke genomics and trans-omics research. It is, however, critical to effectively engage African stroke patients and community members who have contributed precious biological materials to the SIREN Biobank to generate appropriate evidence base for dealing with ethical, legal

Magnetotelluric data, Taos Plateau Volcanic Field, New Mexico

USGS Publications Warehouse

Ailes, Chad E.; Rodriguez, Brian D.

2010-01-01

The population of the San Luis Basin region of northern New Mexico is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's groundwater resources. An important issue in managing the groundwater resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal groundwater aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifers. This report describes a regional east-west MT sounding profile acquired in late July 2009 across the Taos Plateau Volcanic Field where drillhole data are sparse. Resistivity modeling of the MT data can be used to help map changes in electrical resistivity with depths that are related to differences in rock types. These various rock types help control the properties of aquifers. The purpose of this report is to release the MT sounding data collected along the east-west profile. No interpretation of the data is included.

"Ain't I a Woman, Too?": Tracing the Experiences of African American Women in Graduate School.

ERIC Educational Resources Information Center

Schwartz, Robert A.; Bower, Beverly L.; Rice, Diana C.; Washington, Charles M.

2003-01-01

Examined the experiences of African American women pursuing graduate degrees in education over 10 years. Survey and focus group data showed very little difference between women who had graduated and those still in school. Women faced challenges in deciding whether or not to attend graduate school and dealing with racism. Respondents were…

Changing Fatherhood: An Exploratory Qualitative Study with African and African Caribbean Men in England

ERIC Educational Resources Information Center

Williams, Robert; Hewison, Alistair; Wildman, Stuart; Roskell, Carolyn

2013-01-01

This paper presents findings from a qualitative study undertaken with 46 African and African Caribbean men exploring their experiences of fatherhood. Data analysis was informed by Connell's theoretical work on changing gender relations. Findings indicate that fathers' lives were mediated by masculinities, racism, gender, migration and generational…

The West African Health Organization's experience in improving the health research environment in the ECOWAS region.

PubMed

Aidam, Jude; Sombié, Issiaka

2016-04-20

The West African Health Organization (WAHO) implemented a research development program in West Africa during 2009-2013 using the Knowledge for Better Health Research Capacity Development Framework, developed by Pang et al. (Bull World Health Organ 81(11):815-820, 2003), on strategies used to improve the research environment. The framework has the following components: stewardship, financing, sustainable resourcing and research utilization. This paper describes how WAHO implemented this research development program in the West African region to help improve the research environment and lessons learnt. This is a retrospective review of the regional research development program using a triangulation of activity reports, an independent evaluation and the authors' experiences with stakeholders. This program was designed to address gaps along the components of the framework and to improve partnership. The activities, results and challenges are summarised for each component of the framework. The independent evaluation was conducted using over 180 semi-structured interviews of key stakeholders in the West African region and activity reports. WAHO and major stakeholders validated these findings during a regional meeting. All 15 ECOWAS countries benefited from this regional research development program. WAHO provided technical and financial support to eight countries to develop their policies, priorities and plans for research development to improve their research governance. WAHO, along with other technical and financial partners, organised many capacity-strengthening trainings in health systems research methodology, resource mobilization, ethical oversight and on HRWeb, a research information management platform. WAHO helped launch a regional network of health research institutions to improve collaboration between regional participating institutions. Further, WAHO developed strategic research partnerships and mobilised additional funding to support the program. The program

Black South Africans in the United States: An Analysis of Their Educational and Practical Training Experiences.

ERIC Educational Resources Information Center

Crawford, Beth S.; Kreidle, Ann M.

A study was done of the experiences of Black South Africans who came to the United States for education and training. The research studied 140 individuals who participated in two programs between 1980 and 1991. Data were collected from the student files and from standard university data from "Profiles of American Colleges" by Barron's…

Three Generations, Three Wars: African American Veterans.

PubMed

Black, Helen K

2016-02-01

This article emerged from pilot research exploring experiences of war and suffering among African American veterans who served in World War II, Korean War, and Vietnam War. Men's experiences as soldiers reflected both racism and the social change that occurred in the Unites States while they served. We used techniques of narrative elicitation, conducting qualitative, ethnographic interviews with each of five veterans in his home. Interviews focused on unique and shared experiences as an African American man and a soldier. Three important themes emerged: (a) Expectations related to War--Although men viewed service to country as an expected part of life, they also expected equal treatment in war, which did not occur; (b) Suffering as an African American--Informants interpreted experiences of suffering in war as related to the lower status of African American servicemen; and (c) Perception of present identity--Each man was honed by the sum of his experiences, including those of combat, racism, and postwar opportunities and obstacles. From 40 to 70 years after the wars were fought, there are few scholarly narrative studies on African American veterans, despite the fact that Korean War Veterans are entering old-old age and few World War II Veterans are alive. The value of pilot research that offers narratives of unheard voices is significant; larger studies can interview more African American veterans to advance knowledge that might soon be lost. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Defense.gov Special Report: African-American History Month

Science.gov Websites

Department of Defense Submit Search African-American History Month: At the Crossroads of Freedom and Equality Links Air Force African-American History Month Special Report Naval History and Heritage Command , African American Navy Experience 2013 African American/Black History Month Tri-signed Letter Presidential

The 2-D magnetotelluric inverse problem solved with optimization

NASA Astrophysics Data System (ADS)

van Beusekom, Ashley E.; Parker, Robert L.; Bank, Randolph E.; Gill, Philip E.; Constable, Steven

2011-02-01

The practical 2-D magnetotelluric inverse problem seeks to determine the shallow-Earth conductivity structure using finite and uncertain data collected on the ground surface. We present an approach based on using PLTMG (Piecewise Linear Triangular MultiGrid), a special-purpose code for optimization with second-order partial differential equation (PDE) constraints. At each frequency, the electromagnetic field and conductivity are treated as unknowns in an optimization problem in which the data misfit is minimized subject to constraints that include Maxwell's equations and the boundary conditions. Within this framework it is straightforward to accommodate upper and lower bounds or other conditions on the conductivity. In addition, as the underlying inverse problem is ill-posed, constraints may be used to apply various kinds of regularization. We discuss some of the advantages and difficulties associated with using PDE-constrained optimization as the basis for solving large-scale nonlinear geophysical inverse problems. Combined transverse electric and transverse magnetic complex admittances from the COPROD2 data are inverted. First, we invert penalizing size and roughness giving solutions that are similar to those found previously. In a second example, conventional regularization is replaced by a technique that imposes upper and lower bounds on the model. In both examples the data misfit is better than that obtained previously, without any increase in model complexity.

School Characteristics and Experiences of African American, Hispanic/Latino, and Native American Youth in Rural Communities: Relation to Educational Aspirations

ERIC Educational Resources Information Center

Irvin, Matthew J.; Byun, Soo-yong; Meece, Judith L.; Reed, Karla S.; Farmer, Thomas W.

2016-01-01

The primary purpose of this study was to examine differences in the school characteristics and experiences of African American, Hispanic/Latino, and Native American youth in rural high schools as well as their relation to educational aspirations. We also investigated the characteristics and experiences of students and their families given that…

The experiences of African-American students majoring in engineering: Cognitive, non-cognitive and situational aspects

NASA Astrophysics Data System (ADS)

Hill, Gloria Pinckney

1997-12-01

To understand the causes for the disproportionately high rate of attrition among ethnic minority students, it is important to consider not only how they differ from the majority population, but what differences exist in personal qualities and academic preparation within groups at particular types of institutions, and within particular majors. The purpose of this study is to examine the experiences of African-American students enrolled in engineering at a predominately white, selective research university to determine which cognitive, non-cognitive and situational variables impact their progress towards graduation. The goal was to see how African-American students who meet or exceed the minimum criteria for admission perceive their experience on campus, and what strategies they use to manage their day-to-day existence. The study was conducted using personal interviews guided by an open-ended questionnaire. The qualitative methodology allowed students to assess the college experience through their own cultural lens, and to identify the cognitive, non-cognitive, and situational variables important to them. Responses were sorted by class and gender, tabulated and grouped into categories. Interpretation was primarily descriptive. Consistencies, inconsistencies, patterns and relationships to concepts in the literature and to the research questions were discussed. Findings indicate that well prepared students become less confident about their commitment to engineering and their ability to succeed academically after they begin matriculating rather than before, and that redefinition of what it means to be academically successful is an effective coping mechanism to sustain the effort required to master courses. The study suggests that the current focus on the impact of the freshman year transition on student retention should be expanded to include the sophomore year. This is particularly true for institutions where engineering students spend the first year in a core

"It's the skin you're in": African-American women talk about their experiences of racism. an exploratory study to develop measures of racism for birth outcome studies.

PubMed

Nuru-Jeter, Amani; Dominguez, Tyan Parker; Hammond, Wizdom Powell; Leu, Janxin; Skaff, Marilyn; Egerter, Susan; Jones, Camara P; Braveman, Paula

2009-01-01

Stress due to experiences of racism could contribute to African-American women's adverse birth outcomes, but systematic efforts to measure relevant experiences among childbearing women have been limited. We explored the racism experiences of childbearing African-American women to inform subsequent development of improved measures for birth outcomes research. Six focus groups were conducted with a total of 40 socioeconomically diverse African-American women of childbearing age in four northern California cities. Women reported experiencing racism (1) throughout the lifecourse, with childhood experiences seeming particularly salient and to have especially enduring effects (2) directly and vicariously, particularly in relation to their children; (3) in interpersonal, institutional, and internalized forms; (4) across different life domains; (5) with active and passive responses; and (6) with pervasive vigilance, anticipating threats to themselves and their children. This exploratory study's findings support the need for measures reflecting the complexity of childbearing African-American women's racism experiences. In addition to discrete, interpersonal experiences across multiple domains and active/passive responses, which have been measured, birth outcomes research should also measure women's childhood experiences and their potentially enduring impact, perceptions of institutionalized racism and internalized negative stereotypes, vicarious experiences related to their children, vigilance in anticipating future racism events, as well as the pervasiveness and chronicity of racism exposure, all of which could be sources of ongoing stress with potentially serious implications for birth outcomes. Measures of racism addressing these issues should be developed and formally tested.

Rhythm experience and Africana culture trial (REACT!): A culturally salient intervention to promote neurocognitive health, mood, and well-being in older African Americans

PubMed Central

Lukach, Alexis J.; Jedrziewski, M. Kathryn; Grove, George A.; Mechanic-Hamilton, Dawn J.; Williams, Shardae S.; Wollam, Mariegold E.; Erickson, Kirk I.

2017-01-01

The Rhythm Experience and Africana Culture Trial (REACT!) is a multi-site randomized controlled intervention study designed to examine the efficacy of using African Dance as a form of moderate-intensity physical activity to improve cognitive function in older African Americans. African Americans are almost two times more likely than Caucasians to experience cognitive impairment in late adulthood. This increased risk may be attributed to lower level and quality of education, lower socioeconomic status, and higher prevalence of vascular diseases, type 2 diabetes, hypertension, and obesity, all of which are recognized as risk factors for dementia. Fortunately, interventions targeting cardiovascular health (i.e., physical activity) are associated with improved neurocognitive function and a reduced risk for dementia, so African Americans may be particularly suited for interventions targeting cardiovascular health and cognitive function. Here, we describe a randomized intervention protocol for increasing physical activity in older (65–75 years) African Americans. Participants (n = 80) at two study locations will be randomized into one of two groups. The treatment group will participate in African Dance three times per week for six months and the control group will receive educational training on Africana history and culture, as well as information about health behaviors, three times per week for six months. If successful, the REACT! study may transform community interventions and serve as a platform and model for testing other populations, age groups, and health outcomes, potentially identifying novel and creative methods for reducing or eliminating health disparities. PMID:27033674

Comparison of Abuse Experiences of Rural and Urban African American Women During Perinatal Period

PubMed Central

Bhandari, Shreya; Bullock, Linda F. C.; Richardson, Jeanita W.; Kimeto, Pamela; Campbell, Jacquelyn C.; Sharps, Phyllis W.

2015-01-01

A subsample of 12 African American women (6 urban and 6 rural) were selected from a larger longitudinal, randomized control trial, Domestic Violence Enhanced Home Visitation (DOVE-R01 900903 National Institute of Nursing Research [NINR]/National Institutes of Health [NIH]). All African American women were chosen to control for any racial- and/or race-related cultural differences that may exist among women across geographical areas. The experiences of abuse during the perinatal period are drawn from in-depth interviews conducted at five points in time during pregnancy and the post-partum period. The analysis describes three major themes that highlight the similarities and differences among rural and urban women. The main themes found were (1) types of abuse, (2) location of abuse, and (3) response to abuse. In addition, two sub-themes (a) defiance and compliance and (b) role of children were also identified. Implications for universal screening for women of reproductive age, safer gun laws, and the need for further research are discussed. PMID:25315478

Gravity and Magnetotelluric Modeling of the Santo Domingo Basin, Northern New Mexico

NASA Astrophysics Data System (ADS)

Zamudio, K. D.; Keithline, N.; Blum, C.; Cunningham, E.; Fromont, A.; Jorgensen, M.; Lee, R.; McBride, K.; Saez Berrios, P.; Harper, C.; Pellerin, L.; McPhee, D.; Ferguson, J. F.

2015-12-01

The Santo Domingo Basin, one of a series of basins within the Rio Grande Rift, is located between Santa Fe and Albuquerque, NM, and has been the focus of research by the Summer of Geophysical Experience (SAGE) program since 2000. Gravity, magnetotelluric (MT), and seismic data have been collected throughout the region, although we are concentrating on gravity and MT data collected during SAGE 2014 and 2015. The study area is located in the center of the Santo Domingo basin, an extensional, Miocene age, rift basin, in an area that was minimally involved in the preceding local Laramide orogenic activity. Rift sediments (~3.5 km thick) are underlain by Eocene age sediments that were shed from adjacent uplifts. Up to 3 km of Mesozoic and Paleozoic sediments are preserved above the Precambrian basement. Geologic outcrop, borehole and seismic reflection data, and known density values were used in the construction of a ~100 km-long, generalized geologic cross section from which a gravity response was calculated. The modeled gravity response makes fairly definitive predictions about the geometry of the basin as well as the stratigraphy and faulting within and bounding the basin. MT data was collected at ten stations within the basin. The MT sounding curves exhibit one-dimensional behavior at short periods (<10 s), not surprisingly considering the relatively flat local structure in the area. Layered-earth MT models, without geologic constraints, show a conductive (<10 ohm-m) layer at ~1.5 km above a more resistive layer (>1000 ohm-m) at ~ 3.5-4 km. Conductivities of the major stratigraphic units have been determined from well logs and previous MT modeling. Forward and inverse MT models constrained by the gravity-modeled geologic cross section are used to develop a conductivity model consistent with the geology, and are a step towards a better unified treatment of MT, seismic and gravity data.

Long-Term Breastfeeding in African American Mothers.

PubMed

Gross, Tyra Toston; Davis, Marsha; Anderson, Alex K; Hall, Jori; Hilyard, Karen

2017-02-01

According to the Centers for Disease Control and Prevention, 39.1% of African American infants are breastfed at 6 months. However, few studies have explored the breastfeeding experiences of African American women who successfully breastfeed to 6 months or longer durations. Research aim: The goal of this qualitative study was to explore the long-term breastfeeding experiences of low-income African American women using the positive deviance approach. African American women with breastfeeding experience were recruited through Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) breastfeeding peer counselors. Eligibility criteria included being age 18 or older, currently participating in WIC, and having breastfed one child for at least 6 months in the past 2 years. Semistructured, in-depth interviews were conducted with 11 participants. Interviews were audio-recorded and professionally transcribed. Transcripts were then analyzed for emerging themes using thematic analysis in NVivo software. Participants had on average three children each, with an average length of breastfeeding of 10.5 months per child. Four main themes developed: (a) deciding to breastfeed, (b) initiating breastfeeding, (c) breastfeeding long-term, and (d) expanding breastfeeding support. Participants offered culturally tailored suggestions to improve breastfeeding support for other African American women: prenatal discussions of breastfeeding with health care providers, African American lactation support personnel and breastfeeding support groups, and African American breastfeeding promotion in print and digital media. Women who participated in this study breastfed for longer durations than the national average for African Americans. Findings can inform practice and research efforts to improve breastfeeding rates in this population using lessons learned from successful women.

African American Single Mothers Raising Sons: Implications for Family Therapy

ERIC Educational Resources Information Center

Gantt, Ann L.; Greif, Geoffrey L.

2009-01-01

Being raised by a single mother is one factor that has been suggested as contributing to the plight of African American males. Yet few studies have focused specifically on African American single mothers' experiences with raising sons. This qualitative study explored the following questions: (1) What are the experiences of African American single…

Generalized analytic solutions and response characteristics of magnetotelluric fields on anisotropic infinite faults

NASA Astrophysics Data System (ADS)

Bing, Xue; Yicai, Ji

2018-06-01

In order to understand directly and analyze accurately the detected magnetotelluric (MT) data on anisotropic infinite faults, two-dimensional partial differential equations of MT fields are used to establish a model of anisotropic infinite faults using the Fourier transform method. A multi-fault model is developed to expand the one-fault model. The transverse electric mode and transverse magnetic mode analytic solutions are derived using two-infinite-fault models. The infinite integral terms of the quasi-analytic solutions are discussed. The dual-fault model is computed using the finite element method to verify the correctness of the solutions. The MT responses of isotropic and anisotropic media are calculated to analyze the response functions by different anisotropic conductivity structures. The thickness and conductivity of the media, influencing MT responses, are discussed. The analytic principles are also given. The analysis results are significant to how MT responses are perceived and to the data interpretation of the complex anisotropic infinite faults.

Experiences of African American Empowerment: A Jamesian Perspective on Agency

ERIC Educational Resources Information Center

Curtis-Tweed, Phyllis

2003-01-01

This essay draws from the work of William James and three African American pragmatists, W.E.B. Du Bois, Ralph Ellison and Cornel West, to explore the moral relevance of the self as an empowered agent among African American youth. The focus is on Jamesian agency as a function of the individual's awareness of options in context, the self-empowerment…

Innovative computational tools for reducing exploration risk through integration of water-rock interactions and magnetotelluric surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Joseph

2017-04-20

Mapping permeability distributions in geothermal reservoirs is essential for reducing the cost of geothermal development. To avoid the cost and sampling bias of measuring permeability directly through drilling, we require remote methods of imaging permeability such as geophysics. Electrical resistivity (or its inverse, conductivity) is one of the most sensitive geophysical properties known to reflect long range fluid interconnection and thus the likelihood of permeability. Perhaps the most widely applied geophysical methods for imaging subsurface resistivity is magnetotellurics (MT) due to its relatively great penetration depths. A primary goal of this project is to confirm through ground truthing at existingmore » geothermal systems that MT resistivity structure interpreted integratively is capable of revealing permeable fluid pathways into geothermal systems.« less

An automatic audio-magnetotelluric equipment, controlled by microprocessor, for the telesurvellance of the volcano Momotombo (Nicaragua)

NASA Astrophysics Data System (ADS)

Clerc, G.; Décriaud, J.-P.; Doyen, G.; Halbwachs, M.; Henrotte, M.; Rémy, J.; Zhang, X.-C.

1984-07-01

A campaign of audio-magnetotelluric soundings in the crater of Momotombo has shown that the structure of this volcano is suitable to a surveillance by this method; it has an only central activity, and the resistivity versus the depth decreases suddenly at least 100 times at about 270 m. So, this technical paper describes the equipment designed and built in order to measure every 2 hr the apparent resistivity in a given direction, at seven frequencies regularly spaced from 5 to 312 Hz. The data are preprocessed to fill only 32 bytes: they are - on the one hand, printed locally for the close surveillance; - on the other hand, transmitted by an ARGOS platform and received in Garchy via satellite for searching studies

The experience of African American women living with HIV: creating a prevention film for teens.

PubMed

Norris, Anne E; DeMarco, Rosanna

2005-01-01

The personal and social costs of HIV are well documented. What remains unknown is the effect of public disclosure of HIV status on the individual who is doing the disclosing. This study describes the experience of four African American women living with HIV who participated in the development of an intergenerational education intervention for African American adolescent girls. These women suggested that they be filmed discussing the "dark side" of HIV in an effort to create an intergenerational education intervention that would alter the risk-taking behavior that they observed in young women in their community. After a rough cut of the film was completed, these women viewed the film and participated in a focus group during which they discussed what it was like to reveal and revisit their own painful experiences associated with becoming infected and then living with HIV. Findings from content analysis of transcribed dialogue included the following positive themes: (a) self-acceptance by telling one's own story and hearing the stories of the other women, (b) a sense of liberation by disclosing publicly one's image and message and letting go of others' judgments, (c) feeling supported by meeting other women who share the same experience, (d) value of using the film to impact or save young people from the pain one has experienced. A negative theme emerged related to personal pain in reliving the individual's history with HIV.

Resistance and Assent: How Racial Socialization Shapes Black Students' Experience Learning African American History in High School

ERIC Educational Resources Information Center

Thornhill, Theodore E.

2016-01-01

African American history is often taught poorly in high school U.S. history courses. However, we know little about how Black students perceive and experience this situation. I use a refined racial socialization framework and interview data with 32 Black college students in the Northeast to investigate how familial racial socialization shapes their…

Racial Identity and Mental Well-Being: The Experience of African American Medical Students, A Report from the Medical Student CHANGE Study.

PubMed

Hardeman, Rachel R; Perry, Sylvia P; Phelan, Sean M; Przedworski, Julia M; Burgess, Diana J; van Ryn, Michelle

2016-06-01

Diversification of the physician workforce continues to be a national priority; however, a paucity of knowledge about the medical school experience for African American medical students limits our ability to achieve this goal. Previous studies document that African American medical students are at greater risk for depression and anxiety. This study moves beyond these findings to explore the role of racial identity (the extent to which a person normatively defines her/himself with regard to race) and its relationship to well-being for African American medical students in their first year of training. This study used baseline data from the Medical Student Cognitive Habits and Growth Evaluation (CHANGE) Study; a large national longitudinal cohort study of 4732 medical students at 49 medical schools in the US racial identity for African American students (n = 301) was assessed using the centrality sub-scale of the Multidimensional Inventory of Black Identity. Generalized linear regression models with a Poisson regression family distribution were used to estimate the relative risks of depression, anxiety, and perceived stress. First year African American medical students who had lower levels of racial identity were less likely to experience depressive and anxiety symptoms in their first year of medical school. After controlling for other important social predictors of poor mental health (gender and SES), this finding remained significant. Results increase knowledge about the role of race as a core part of an individual's self-concept. These findings provide new insight into the relationship between racial identity and psychological distress, particularly with respect to a group of high-achieving young adults.

Urban African American High School Female Adolescents' Perceptions, Attitudes, and Experiences with Professional School Counselors: A Pilot Study

ERIC Educational Resources Information Center

Owens, Delila; Stewart, Tiffany A.; Bryant, Rhonda M.

2011-01-01

The authors interviewed African American female students in an urban school district about their perceptions, attitudes, and experiences with their professional school counselors. Data analysis indicated seven primary themes perceived by the participants, some of which included their understanding and purpose of professional school counselors and…

“It's The Skin You're In”: African-American Women Talk About Their Experiences of Racism. An Exploratory Study to Develop Measures of Racism for Birth Outcome Studies

PubMed Central

Nuru-Jeter, Amani; Dominguez, Tyan Parker; Hammond, Wizdom Powell; Leu, Janxin; Skaff, Marilyn; Egerter, Susan; Jones, Camara P.; Braveman, Paula

2011-01-01

Objectives Stress due to experiences of racism could contribute to African-American women's adverse birth outcomes, but systematic efforts to measure relevant experiences among childbearing women have been limited. We explored the racism experiences of childbearing African-American women to inform subsequent development of improved measures for birth outcomes research. Methods Six focus groups were conducted with a total of 40 socioeconomically diverse African-American women of childbearing age in four northern California cities. Results Women reported experiencing racism (1) throughout the lifecourse, with childhood experiences seeming particularly salient and to have especially enduring effects (2) directly and vicariously, particularly in relation to their children; (3) in interpersonal, institutional, and internalized forms; (4) across different life domains; (5) with active and passive responses; and (6) with pervasive vigilance, anticipating threats to themselves and their children. Conclusions This exploratory study's findings support the need for measures reflecting the complexity of childbearing African-American women's racism experiences. In addition to discrete, interpersonal experiences across multiple domains and active/passive responses, which have been measured, birth outcomes research should also measure women's childhood experiences and their potentially enduring impact, perceptions of institutionalized racism and internalized negative stereotypes, vicarious experiences related to their children, vigilance in anticipating future racism events, as well as the pervasiveness and chronicity of racism exposure, all of which could be sources of ongoing stress with potentially serious implications for birth outcomes. Measures of racism addressing these issues should be developed and formally tested. PMID:18463971

Mother Tongue Education: The West African Experience.

ERIC Educational Resources Information Center

Bamgbose, Ayo, Ed.

In the rapidly changing political, economic, and social life of West Africa, there is a renewed interest in cultural identity. This book describes the developments and the difficulties experienced by different West African countries in the use of mother tongues in multi-lingual society. The book was commissioned to give scholars, educators, and…

South Africans' experiences of being old and of care and caring in a transitional period.

PubMed

Bohman, Doris M; van Wyk, Neltjie C; Ekman, Sirkka-Liisa

2011-09-01

This focused ethnographic study aimed to illuminate a group of South Africans' experiences of being old and of care and caring in a transitional period. With a growing number of older people in Africa, studies on the individual experiences may help to develop care which is more sensitively based on the needs for older people in a changing Southern Africa context. Data were collected through group and individual in-depth interviews and participant observations which involved 16 individuals, aged 52-76. Data were analysed using a qualitative content analysis. The study showed two interrelated themes reflections on life and ubuntu - an orientation towards others. Findings were discussed from the viewpoint of the theory of gerotranscendence, showing similarities as well as differences, possibly due to societal and cultural differences. Shortage of formal care for older people living in poor conditions in Southern Africa, gave rise to the discussion for the need of a contextualized development of gerontological care. To enhance knowledge on the theory of gerotranscendence and develop guidelines for nursing in home-based care/community-based care in a South African context may be a first step to support older people in their process towards gerotranscendence. © 2010 Blackwell Publishing Ltd.

Rhythm experience and Africana culture trial (REACT!): A culturally salient intervention to promote neurocognitive health, mood, and well-being in older African Americans.

PubMed

Lukach, Alexis J; Jedrziewski, M Kathryn; Grove, George A; Mechanic-Hamilton, Dawn J; Williams, Shardae S; Wollam, Mariegold E; Erickson, Kirk I

2016-05-01

The Rhythm Experience and Africana Culture Trial (REACT!) is a multi-site randomized controlled intervention study designed to examine the efficacy of using African Dance as a form of moderate-intensity physical activity to improve cognitive function in older African Americans. African Americans are almost two times more likely than Caucasians to experience cognitive impairment in late adulthood. This increased risk may be attributed to lower level and quality of education, lower socioeconomic status, and higher prevalence of vascular diseases, type 2 diabetes, hypertension, and obesity, all of which are recognized as risk factors for dementia. Fortunately, interventions targeting cardiovascular health (i.e., physical activity) are associated with improved neurocognitive function and a reduced risk for dementia, so African Americans may be particularly suited for interventions targeting cardiovascular health and cognitive function. Here, we describe a randomized intervention protocol for increasing physical activity in older (65-75years) African Americans. Participants (n=80) at two study locations will be randomized into one of two groups. The treatment group will participate in African Dance three times per week for six months and the control group will receive educational training on Africana history and culture, as well as information about health behaviors, three times per week for six months. If successful, the REACT! study may transform community interventions and serve as a platform and model for testing other populations, age groups, and health outcomes, potentially identifying novel and creative methods for reducing or eliminating health disparities. Copyright © 2016 Elsevier Inc. All rights reserved.

African Americans and World War II.

ERIC Educational Resources Information Center

Kersten, Andrew E.

2002-01-01

Focuses on the experience of African Americans during World War II on the homefront and in the armed forces. States that African Americans not only fought fascism overseas but also apartheid in the United States, also known as the "Double V." (CMK)

Educating Tomorrow's Men: Perceived School Support, Negative Youth Experiences, and Bravado Attitudes in African American Adolescent Males

ERIC Educational Resources Information Center

Corprew, Charles S., III; Cunningham, Michael

2012-01-01

The purpose of this study was to explore the association between negative youth experiences and bravado attitudes in African American urban males. In addition, an examination of positive factors, such as school social support, was examined to understand potential resilient pathways. Data were collected at two sites, a science and math center (n =…

Racial discrimination experiences and African American youth adjustment: The role of parenting profiles based on racial socialization and involved-vigilant parenting.

PubMed

Varner, Fatima A; Hou, Yang; Hodzic, Tajma; Hurd, Noelle M; Butler-Barnes, Sheretta T; Rowley, Stephanie J

2018-04-01

The purpose of this study was to test whether parenting profiles based on racial socialization and involved-vigilant parenting would compensate for or moderate associations between racial discrimination experiences and academic outcomes and psychological well-being among African American adolescents. Participants were 1,363 African American adolescents (M age = 14.19; 52.3% female) from 3 Midwestern suburban school districts. Latent profile analysis was used to examine whether there were distinct combinations of parenting. The relationships among racial discrimination experiences, parenting profiles, and adjustment were examined using structural equation modeling (SEM). Three distinct parenting profiles were found: moderate positive (n = 767; moderately high involved-vigilant parenting and racial barrier, racial pride, behavioral, and egalitarian messages, and low negative messages), unengaged (n = 351; low racial socialization messages and moderately low involved-vigilant parenting), and high negative parenting (n = 242; high negative messages, moderate other racial socialization messages, and moderately low involved-vigilant parenting). Racial discrimination experiences were negatively associated with youth adjustment. Moderate positive parenting was related to the best academic outcomes and unengaged parenting was associated with more positive academic outcomes than high negative parenting. Moderate positive parenting was associated with better psychological well-being than unengaged or high negative parenting although the benefits were greater for adolescents with fewer racial discrimination experiences. Distinct patterns of racial socialization messages and involved-vigilant parenting contribute to differences in African American youth adjustment. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A Day in the Life of African American and European American College Students: Daily Affective Experience and Perceptions of Climate at a Predominantly White Institution

ERIC Educational Resources Information Center

Birk, Nancy Adair

2009-01-01

In the context of the under-representation of African Americans in higher education and the lawsuits targeting affirmative action policies in college admissions, the purpose of this study was to examine the daily affective experiences of African American and European American students at a predominantly White institution, exploring the activities…

Exploring How African American Males from an Urban Community Navigate the Interracial and Intra-Racial Dimensions of Their Experiences at an Urban Jesuit High School

ERIC Educational Resources Information Center

Simmons, Robert W., III

2012-01-01

African American males from urban communities have been attending Jesuit high schools in urban spaces for many years, yet little to no literature exists that explores their experiences while attending these elite private schools. This qualitative study of 10 African American males from an urban community attending a similarly positioned Jesuit…

Surviving oppression under the rock: the intersection of New York's drug, welfare, and educational polices in the lived experiences of low-income African Americans.

PubMed

Windsor, Liliane Cambraia; Dunlap, Eloise; Armour, Marilyn

2012-01-01

Drawing on standpoint and intersectionality theories, this study explores the degree to which interactions among New York State's Rockefeller Drug Laws and educational and welfare policies have contributed to the maintenance of a culture of surveillance in which the lives of impoverished African Americans are overseen and influenced by oppressive policies and governmental institutions. Qualitative secondary analysis of longitudinal ethnographic data was conducted. Findings demonstrate multiple disadvantages that impoverished African American families struggling with substance use or sale experience. These disadvantages accumulated intergenerationally, in a snowball effect, making it difficult for participants to maintain stable lives. Findings explored the tension between participants' lived experiences and the multiple ways they either assimilated or resisted their oppression. New sensitive policies informed by standpoint, intersectionality, and Afrocentric perspectives must be developed to increase the availability of meaningful employment and strengthening impoverished African American communities.

Characterization of Clastic Dikes Using Controlled Source Audio Magnetotellurics

NASA Astrophysics Data System (ADS)

Persichetti, J. A.; Alumbaugh, D.

2001-12-01

A site consisting of 3D geology on the Hanford Reservation in Hanford, Washington, has been surveyed using Controlled Source Audio Magnetotellurics (CSAMT) to determine the method's ability to detect clastic dikes. The dikes are fine-grained, soft-sediment intrusions, formed by the buoyant rise of buried, unconsolidated, water rich mud into overlying unconsolidated sediment. The dikes are of major importance because they may act as natural barriers inhibiting the spread of contaminants, or as conduits, allowing the contaminants to be quickly wicked away from the contaminant storage tanks that may be located in close vicinity of the dikes. The field setup consisted of a 33 meter by 63 meter receiver grid with 3 meter spacing in all directions with the transmitter positioned 71.5 meters from the center of the receiver grid. A total of 12 frequencies were collected from 1.1kHz to 66.2kHz. The CSAMT data is being analyzed using a 2D CSAMT RRI code (Lu, Unsworth and Booker, 1999) and a 2D MT RRI code (Smith and Booker, 1991). Of interest is examining how well the 2D codes are able to map 3D geology, the level of resolution that is obtained, and how important it is to include the 3D source in the solution. The ultimate goal is to determine the applicability of using CSAMT for mapping these types of features at the Hanford Reservation site.

Efficient hierarchical trans-dimensional Bayesian inversion of magnetotelluric data

NASA Astrophysics Data System (ADS)

Xiang, Enming; Guo, Rongwen; Dosso, Stan E.; Liu, Jianxin; Dong, Hao; Ren, Zhengyong

2018-06-01

This paper develops an efficient hierarchical trans-dimensional (trans-D) Bayesian algorithm to invert magnetotelluric (MT) data for subsurface geoelectrical structure, with unknown geophysical model parameterization (the number of conductivity-layer interfaces) and data-error models parameterized by an auto-regressive (AR) process to account for potential error correlations. The reversible-jump Markov-chain Monte Carlo algorithm, which adds/removes interfaces and AR parameters in birth/death steps, is applied to sample the trans-D posterior probability density for model parameterization, model parameters, error variance and AR parameters, accounting for the uncertainties of model dimension and data-error statistics in the uncertainty estimates of the conductivity profile. To provide efficient sampling over the multiple subspaces of different dimensions, advanced proposal schemes are applied. Parameter perturbations are carried out in principal-component space, defined by eigen-decomposition of the unit-lag model covariance matrix, to minimize the effect of inter-parameter correlations and provide effective perturbation directions and length scales. Parameters of new layers in birth steps are proposed from the prior, instead of focused distributions centred at existing values, to improve birth acceptance rates. Parallel tempering, based on a series of parallel interacting Markov chains with successively relaxed likelihoods, is applied to improve chain mixing over model dimensions. The trans-D inversion is applied in a simulation study to examine the resolution of model structure according to the data information content. The inversion is also applied to a measured MT data set from south-central Australia.

What makes African American health disparities newsworthy? An experiment among journalists about story framing.

PubMed

Hinnant, Amanda; Oh, Hyun Jee; Caburnay, Charlene A; Kreuter, Matthew W

2011-12-01

News stories reporting race-specific health information commonly emphasize disparities between racial groups. But recent research suggests this focus on disparities has unintended effects on African American audiences, generating negative emotions and less interest in preventive behaviors (Nicholson RA, Kreuter MW, Lapka C et al. Unintended effects of emphasizing disparities in cancer communication to African-Americans. Cancer Epidemiol Biomarkers Prev 2008; 17: 2946-52). They found that black adults are more interested in cancer screening after reading about the progress African Americans have made in fighting cancer than after reading stories emphasizing disparities between blacks and whites. This study builds on past findings by (i) examining how health journalists judge the newsworthiness of stories that report race-specific health information by emphasizing disparities versus progress and (ii) determining whether these judgments can be changed by informing journalists of audience reactions to disparity versus progress framing. In a double-blind-randomized experiment, 175 health journalists read either a disparity- or progress-framed story on colon cancer, preceded by either an inoculation about audience effects of such framing or an unrelated (i.e. control) information stimuli. Journalists rated the disparity-frame story more favorably than the progress-frame story in every category of news values. However, the inoculation significantly increased positive reactions to the progress-frame story. Informing journalists of audience reactions to race-specific health information could influence how health news stories are framed.

What makes African American health disparities newsworthy? An experiment among journalists about story framing

PubMed Central

Hinnant, Amanda; Oh, Hyun Jee; Caburnay, Charlene A.; Kreuter, Matthew W.

2011-01-01

News stories reporting race-specific health information commonly emphasize disparities between racial groups. But recent research suggests this focus on disparities has unintended effects on African American audiences, generating negative emotions and less interest in preventive behaviors (Nicholson RA, Kreuter MW, Lapka C et al. Unintended effects of emphasizing disparities in cancer communication to African-Americans. Cancer Epidemiol Biomarkers Prev 2008; 17: 2946–52). They found that black adults are more interested in cancer screening after reading about the progress African Americans have made in fighting cancer than after reading stories emphasizing disparities between blacks and whites. This study builds on past findings by (i) examining how health journalists judge the newsworthiness of stories that report race-specific health information by emphasizing disparities versus progress and (ii) determining whether these judgments can be changed by informing journalists of audience reactions to disparity versus progress framing. In a double-blind-randomized experiment, 175 health journalists read either a disparity- or progress-framed story on colon cancer, preceded by either an inoculation about audience effects of such framing or an unrelated (i.e. control) information stimuli. Journalists rated the disparity-frame story more favorably than the progress-frame story in every category of news values. However, the inoculation significantly increased positive reactions to the progress-frame story. Informing journalists of audience reactions to race-specific health information could influence how health news stories are framed. PMID:21911844

Measuring health systems strength and its impact: experiences from the African Health Initiative.

PubMed

Sherr, Kenneth; Fernandes, Quinhas; Kanté, Almamy M; Bawah, Ayaga; Condo, Jeanine; Mutale, Wilbroad

2017-12-21

Health systems are essential platforms for accessible, quality health services, and population health improvements. Global health initiatives have dramatically increased health resources; however, funding to strengthen health systems has not increased commensurately, partially due to concerns about health system complexity and evidence gaps demonstrating health outcome improvements. In 2009, the African Health Initiative of the Doris Duke Charitable Foundation began supporting Population Health Implementation and Training Partnership projects in five sub-Saharan African countries (Ghana, Mozambique, Rwanda, Tanzania, and Zambia) to catalyze significant advances in strengthening health systems. This manuscript reflects on the experience of establishing an evaluation framework to measure health systems strength, and associate measures with health outcomes, as part of this Initiative. Using the World Health Organization's health systems building block framework, the Partnerships present novel approaches to measure health systems building blocks and summarize data across and within building blocks to facilitate analytic procedures. Three Partnerships developed summary measures spanning the building blocks using principal component analysis (Ghana and Tanzania) or the balanced scorecard (Zambia). Other Partnerships developed summary measures to simplify multiple indicators within individual building blocks, including health information systems (Mozambique), and service delivery (Rwanda). At the end of the project intervention period, one to two key informants from each Partnership's leadership team were asked to list - in rank order - the importance of the six building blocks in relation to their intervention. Though there were differences across Partnerships, service delivery and information systems were reported to be the most common focus of interventions, followed by health workforce and leadership and governance. Medical products, vaccines and technologies, and

EMSCOPE - Electromagnetic Component of EarthScope Backbone and Transportable Array Experiments 2006-2008

NASA Astrophysics Data System (ADS)

Egbert, G.; Evans, R.; Ingate, S.; Livelybrooks, D.; Mickus, K.; Park, S.; Schultz, A.; Unsworth, M.; Wannamaker, P.

2007-12-01

USArray (http://www.iris.edu/USArray) in conjunction with EMSOC (Electromagnetic Studies of the Continents) (http://emsoc.ucr.edu/emsoc) is installing magnetotelluric (MT) stations as part of Earthscope. The MT component of Earthscope consists of permanent (Backbone) and transportable long period stations to record naturally occurring, time varying electric and magnetic fields to produce a regional lithospheric/asthensospheric electrical conductivity map of the United States. The recent arrival of 28 long period MT instruments allows for the final installation of the Backbone stations throughout the US and yearly transportable array studies. The Backbone MT survey consists of 7 stations spaced throughout the continental US with preliminary installation at Soap Creek, Oregon; Parkfield, California; Braden, Missouri and Socorro, New Mexico.Siting and permitting are underway or completed at stations in eastern Montana, northern Wisconsin and Virginia. These stations will be recording for at least five years to determine electrical conductivities at depths that extend into the mantle transition zone. The first transportable array experiment was performed in the summer and fall of 2006 in central and eastern Oregon (Oregon Pilot Project) using equipment loaned from EMSOC. Thirty-one long period MT stations were recorded with 14 to 21 day occupations. Preliminary 3D inverse models indicate several lithospheric electrical conductivity anomalies including a linear zone marked by low-high conductivity transition along the Klamath-Blue Mountain Lineament associated with a linear trend of gravity minima. High electrical conductivity values occur in the upper crust under the accreted terrains in the Blue Mountains region. The second transportable array experiment was performed in the summer and fall of 2007 and completes coverage of the Oregon, Washington, and western Idaho, targeting the Cascadia subduction zone, Precambrian boundaries, and sub-basalt lithologies. The 2008

Health Behaviors and Breast Cancer: Experiences of Urban African American Women

ERIC Educational Resources Information Center

Stolley, Melinda R.; Sharp, Lisa K.; Wells, Anita M.; Simon, Nolanna; Schiffer, Linda

2006-01-01

Breast-cancer survival rates are lower among African American women compared to White women. Obesity may contribute to this disparity. More than 77% of African American women are overweight or obese. Adopting health behaviors that promote a healthy weight status may be beneficial because obesity increases risk for recurrence. Studies among White…

Relationships between discretionary time activities, emotional experiences, delinquency and depressive symptoms among urban African American adolescents.

PubMed

Bohnert, Amy M; Richards, Maryse; Kohl, Krista; Randall, Edin

2009-04-01

Using the Experience Sampling Method (ESM), this cross-sectional study examined mediated and moderated associations between different types of discretionary time activities and depressive symptoms and delinquency among a sample of 246 (107 boys, 139 girls) fifth through eighth grade urban African American adolescents. More time spent in passive unstructured activities was associated with higher levels of depressive symptoms only for adolescents residing in less dangerous neighborhoods, whereas more time spent in active unstructured activities was associated with higher levels of delinquency only if adolescents resided in more dangerous neighborhoods. Alienation was positively associated with depressive symptoms and delinquency, but neither alienation nor positive affect mediated the relationship between activities and adjustment. These findings suggest the importance of considering neighborhood environment issues when determining what types of discretionary time activities are most beneficial for urban African American young adolescents.

Regulatory challenges for GM crops in developing economies: the African experience.

PubMed

Nang'ayo, Francis; Simiyu-Wafukho, Stella; Oikeh, Sylvester O

2014-12-01

Globally, transgenic or genetically modified (GM) crops are considered regulated products that are subject to regulatory oversight during trans-boundary movement, testing and environmental release. In Africa, regulations for transgenic crops are based on the outcomes of the historic Earth Summit Conference held in Rio, Brazil two decades ago, namely, the adoption of the Convention on Biological Diversity (CBD) and the subsequent adoption of the Cartagena Protocol on Biosafety. To exploit the potential benefits of transgenic crops while safeguarding the potential risks on human health and environment, most African countries have signed and ratified the CBD and the Cartagena Protocol on Biosafety. Consequently, these countries are required to take appropriate legal, administrative and other measures to ensure that the handling and utilization of living modified organisms are undertaken in a manner that reduces the risks to humans and the environment. These countries are also expected to provide regulatory oversight on transgenic crops through functional national biosafety frameworks (NBFs). While in principle this approach is ideal, NBFs in most African countries are steeped in a host of policy, legal and operational challenges that appear to be at cross-purposes with the noble efforts of seeking to access, test and deliver promising GM crops for use by resource-limited farmers in Africa. In this paper we discuss the regulatory challenges faced during the development and commercialization of GM crops based on experiences from countries in Sub-Saharan Africa.

Understanding the Subjective Experience of Medication Adherence for Older Urban African Americans With Type 2 Diabetes and a History of Illicit Drug Addiction.

PubMed

Wallace, Brandy Harris; Reese, Ashante M; Chard, Sarah; Roth, Erin G; Quinn, Charlene; Eckert, J Kevin

2017-04-01

African Americans experience high rates of type 2 diabetes mellitus (T2D). Self-management strategies, such as medication adherence, are key to mitigating negative T2D outcomes. This article addresses a gap in the literature by examining the intersections of drug abuse histories and medication adherence among urban, older African Americans with T2D. In-depth interview data were collected as part of a larger ethnographic study examining the subjective experience of T2D among urban older adults. Two representative focal cases were selected and thematic analysis performed to illustrate how former illicit drug addicts perceive prescription medication usage. Narratives reveal that participants are displeased about having to take prescription drugs and are making lifestyle changes to reduce medication usage and maintain sobriety. Previous drug abuse not only complicates medication adherence but is also a significant part of how older African Americans who are former drug users frame their understanding of T2D more broadly.

When Failing Doesn't Matter: A Narrative Inquiry into the Social Work Practice Learning Experiences of Black African Students in England

ERIC Educational Resources Information Center

Tedam, Prospera

2014-01-01

This paper reports the findings of a small-scale empirical study into the practice learning experiences of black African students of social work in England. Undertaken in the form of a pilot study, the findings reveal that practice learning experiences can be beneficial in enhancing skills and knowledge but can also cause distress, lower…

Longitudinal links between work experiences and marital satisfaction in african american dual-earner couples.

PubMed

Sun, Xiaoran; McHale, Susan M; Crouter, Ann C; Jones, Damon E

2017-12-01

This study assessed associations between both work demands (pressure, hours) and work resources (self-direction) and marital satisfaction in a sample of 164 African American dual-earner couples who were interviewed annually across 3 years. Grounded in the work-home resources and family systems frameworks, results from longitudinal actor-partner interdependence models (APIM) revealed main effects of spouses' work experiences on their own marital satisfaction, but these effects were qualified by the interactive effects of spouses' and partners' work experiences. Some interactive effects were consistent with an amplifying pattern, for example that, beyond the main effects of actor self-direction, marital satisfaction was highest when both spouses experienced high work self-direction. Other effects were consistent with a comparative pattern, such that shorter work hours were linked to lower marital satisfaction only when partners worked longer hours. Gender moderation also was evident in findings that wives' work pressure was negatively linked to marital satisfaction only when their husbands reported high pressure, but husbands' work pressure was negatively linked to marital satisfaction only when their wives reported low pressure. This study advances understanding of work-marriage linkages in African American couples, an understudied group with a distinctive connection to the labor force. Analyses demonstrate what can be learned from investigating the couple as a unit and illustrate how family systems concepts can be addressed via APIM. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

High-Resolution Lithosphere Viscosity and Dynamics Revealed by Magnetotelluric Imaging

NASA Astrophysics Data System (ADS)

Liu, L.; Hasterok, D. P.

2016-12-01

An accurate viscosity structure is critical to truthfully modeling continental lithosphere dynamics, especially at spatial scales of <200 km where active tectonic deformation and volcanism occur. However, the effective viscosity structure of the lithosphere remains a key challenge in geodynamics due to the intimate involvement of viscosity with time and its dependence on many factors including strain rate, plastic failure, composition, and grain size. Current efforts on inferring the detailed lithosphere viscosity structure are sparse and large uncertainties and discrepancies still exist. Here we report an attempt to infer the effective lithospheric viscosity from a high-resolution magnetotelluric (MT) survey across the western United States. The high sensitivity of MT fields to the presence of electrically conductive fluids makes it a promising proxy for determining mechanical strength variations throughout the lithosphere. We demonstrate how a viscosity structure, approximated from electrical resistivity, results in a geodynamic model that successfully predicts short-wavelength surface topography, lithospheric deformation, and mantle upwelling beneath recent volcanism. The results indicate that lithosphere viscosity structure rather than the buoyancy structure is the dominant controlling factor for short-wavelength topography and intra-plate deformation in tectonically active regions. We further show that this viscosity is consistent with and more effective than that derived from laboratory-based rheology. We therefore propose that MT imaging provides a practical observational constraint for quantifying the dynamic evolution of the continental lithosphere.

Source biases in midlatitude magnetotelluric transfer functions due to Pc3-4 geomagnetic pulsations

NASA Astrophysics Data System (ADS)

Murphy, Benjamin S.; Egbert, Gary D.

2018-01-01

The magnetotelluric (MT) method for imaging the electrical conductivity structure of the Earth is based on the assumption that source magnetic fields can be considered quasi-uniform, such that the spatial scale of the inducing source is much larger than the intrinsic length scale of the electromagnetic induction process (the skin depth). Here, we show using EarthScope MT data that short spatial scale source magnetic fields from geomagnetic pulsations (Pc's) can violate this fundamental assumption. Over resistive regions of the Earth, the skin depth can be comparable to the short meridional range of Pc3-4 disturbances that are generated by geomagnetic field-line resonances (FLRs). In such cases, Pc's can introduce narrow-band bias in MT transfer function estimates at FLR eigenperiods ( 10-100 s). Although it appears unlikely that these biases will be a significant problem for data inversions, further study is necessary to understand the conditions under which they may distort inverse solutions.[Figure not available: see fulltext.

The magnetotelluric phase tensor analysis of the Sembalun-Propok area, West Nusa Tenggara, Indonesia

NASA Astrophysics Data System (ADS)

Febriani, F.; Widarto, D. S.; Gaffar, E.; Nasution, A.; Grandis, H.

2017-04-01

The subsurface structure of the Sembalun-Propok area, NTB, Indonesia, has been investigated using magnetotelluric method (MT). To obtain the information of the dimensionality of the regional structure and determine the regional strike of the study area, the phase tensor analysis has been performed in this study. The results show that most of the skew angle values (β) are distributed within ± 5°. It indicates that the regional structure of the study area can be assumed as two dimensional. In addition, to determine the regional strike of the study area, we also calculated the major axes of the phase tensor. The result presents that the regional strike of the study area is about N330°E. According to the results of the phase tensor analysis, we rotated the impedance tensor to N330°E and performed 2-D inversion modeling. The result presents that the substructure model suits with the geological background of the study area.

THE CHALLENGES OF SCHOOL-BASED YOUTH SUICIDE PREVENTION: EXPERIENCES AND PERCEPTIONS OF MENTAL HEALTH PROFESSIONALS IN SOUTH AFRICAN SCHOOLS.

PubMed

Woolf, Maryke; Bantjes, Jason; Kagee, Ashraf

2015-01-01

Youth suicidal behaviour poses a significant public health concern. Mental health care professionals working in schools have an important role to play in youth suicide prevention initiatives, although little is known of the experiences of this group of professionals in the developing world. The aim of this study was to explore the experiences of mental health professionals working in South African schools and document their insights, attitudes and beliefs regarding youth suicidal behaviour. In-depth semi-structured interviews were conducted with seven school-based mental health care professionals and data were analysed using Thematic Analysis. Participants reported that they relied on a reactive strategy by responding to youths who were in crisis. They were challenged by a lack of support from faculty staff, lack of access to resources, and heavy caseloads. Findings highlight the need for a proactive and collaborative approach to suicide prevention among mental health care professionals, teachers and parents in South African schools and improved training and supervision.

THE CHALLENGES OF SCHOOL-BASED YOUTH SUICIDE PREVENTION: EXPERIENCES AND PERCEPTIONS OF MENTAL HEALTH PROFESSIONALS IN SOUTH AFRICAN SCHOOLS

PubMed Central

Woolf, Maryke; Bantjes, Jason; Kagee, Ashraf

2016-01-01

Youth suicidal behaviour poses a significant public health concern. Mental health care professionals working in schools have an important role to play in youth suicide prevention initiatives, although little is known of the experiences of this group of professionals in the developing world. The aim of this study was to explore the experiences of mental health professionals working in South African schools and document their insights, attitudes and beliefs regarding youth suicidal behaviour. In-depth semi-structured interviews were conducted with seven school-based mental health care professionals and data were analysed using Thematic Analysis. Participants reported that they relied on a reactive strategy by responding to youths who were in crisis. They were challenged by a lack of support from faculty staff, lack of access to resources, and heavy caseloads. Findings highlight the need for a proactive and collaborative approach to suicide prevention among mental health care professionals, teachers and parents in South African schools and improved training and supervision. PMID:27990493

A combinatorial filtering method for magnetotelluric time-series based on Hilbert-Huang transform

NASA Astrophysics Data System (ADS)

Cai, Jianhua

2014-11-01

Magnetotelluric (MT) time-series are often contaminated with noise from natural or man-made processes. A substantial improvement is possible when the time-series are presented as clean as possible for further processing. A combinatorial method is described for filtering of MT time-series based on the Hilbert-Huang transform that requires a minimum of human intervention and leaves good data sections unchanged. Good data sections are preserved because after empirical mode decomposition the data are analysed through hierarchies, morphological filtering, adaptive threshold and multi-point smoothing, allowing separation of noise from signals. The combinatorial method can be carried out without any assumption about the data distribution. Simulated data and the real measured MT time-series from three different regions, with noise caused by baseline drift, high frequency noise and power-line contribution, are processed to demonstrate the application of the proposed method. Results highlight the ability of the combinatorial method to pick out useful signals, and the noise is suppressed greatly so that their deleterious influence is eliminated for the MT transfer function estimation.

Electrical resistivity structure at the North-Central Turkey inferred from three-dimensional magnetotellurics

NASA Astrophysics Data System (ADS)

Özaydın, Sinan; Tank, Sabri Bülent; Karaş, Mustafa

2018-03-01

Magnetotelluric data analyses and three-dimensional modeling techniques were implemented to investigate the crustal electrical structure in the North-Central Turkey, along a 190-km-long profile crossing Çankırı Basin, İzmir-Ankara-Erzincan Suture Zone and Central Pontides. In this area, the segment of the North Anatolian Fault (NAF) shows 280-km-long restraining bend, where it was near the focus of the hazardous 1943 Tosya Earthquake (M: 7.6). Structure around the NAF exhibits resistive characteristics at both sides of the fault reaching to at least 25 km of depth. Fluids below the brittle-ductile transition were not detected which will nucleate earthquakes in the area. This resistive structure implies an asperity zone of the NAF, which was ruptured in 1943. The presence of a fluid-bearing upwelling conductive anomaly in Central Pontides may suggest that beneath the deep brittle crust, there may exists a fluid-enriched conductive forearc region, which may have caused by a prograde source related to paleo-tectonic processes.

Likelihood of Brine and CO 2 Leak Detection using Magnetotellurics and Electrical Resistivity Tomography Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, X.; Buscheck, T. A.; Mansoor, K.

The US DOE National Risk Assessment Partnership (NRAP), funded through the Office of Fossil Energy and NETL, is developing methods to evaluate the effectiveness of monitoring techniques to detect brine and CO 2 leakage from legacy wells into underground sources of drinking water (USDW) overlying a CO 2 storage reservoir. As part of the NRAP Strategic Monitoring group, we have generated 140 simulations of aquifer impact data based on the Kimberlina site in California’s southern San Joaquin Basin, Kimberlina Rev. 1.1. CO 2 buoyancy allows some of the stored CO 2 to reach shallower permeable zones and is detectable withmore » surface geophysical sensors. We are using this simulated data set to evaluate effectiveness of electrical resistivity tomography (ERT) and magnetotellurics (MT) for leak detection. The evaluation of additional monitoring methods such as pressure, seismic and gravity is underway through a multi-lab collaboration.« less

Parental Attachments and Psychological Distress among African American College Students

ERIC Educational Resources Information Center

Love, Keisha McGhee

2008-01-01

African American college students attending predominately White institutions often encounter stressors that their Caucasian peers do not experience. Because of these unique stressors, African American students are more prone to experience psychological distress. Identifying factors that counteract psychological distress among these students is…

The importance of vegetation density for tourists' wildlife viewing experience and satisfaction in African savannah ecosystems.

PubMed

Arbieu, Ugo; Grünewald, Claudia; Schleuning, Matthias; Böhning-Gaese, Katrin

2017-01-01

Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists' wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors' attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors' satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists' experience, and positive relationships between perceived mammal densities and wildlife tourists' experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists' satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists' wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism.

The importance of vegetation density for tourists’ wildlife viewing experience and satisfaction in African savannah ecosystems

PubMed Central

Grünewald, Claudia; Schleuning, Matthias; Böhning-Gaese, Katrin

2017-01-01

Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists’ wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors’ attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors’ satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists’ experience, and positive relationships between perceived mammal densities and wildlife tourists’ experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists’ satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists’ wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism. PMID:28957420

Conceptualizing the African American Mathematics Teacher as a Key Figure in the African American Education Historical Narrative

ERIC Educational Resources Information Center

Clark, Lawrence M.; Jones Frank, Toya; Davis, Julius

2013-01-01

Background/Context: Historians and researchers have documented and explored the work and role of African American teachers in the U.S. educational system, yet there has been limited attention to the specific work, role, and experiences of African American mathematics teachers. To meaningfully and responsibly conceptualize the role of African…

Magnetotelluric Investigation in the Jiyang Depression and its Adjacent Areas

NASA Astrophysics Data System (ADS)

Zhang, L.; Hao, T.; Duan, Q.

2008-12-01

The Jiyang Depression is a secondary tectonic unit of the Bohai Bay Basin, and is a Mesozoic-Cenozoic continental-facie depositional depression. The Jiyang Depression consists of the Dongying, Zanhua, Chezhen, and Huimin sags, and the Yihezhuang, Chenjiazhuang, Qingcheng, Binxian, Guangrao, Shouguang, and heaves. In order to delineate shallow and deep structures of the depression, we conduct a magnetotelluric (MT) investigation in the Jiyang Depression and its adjacent areas. We use a remote reference setup to reduce noise disturbance, when several magnetotelluric sounding stations are measuring synchronously at different sites. The acquired MT data are to be processed and interpreted. We execute time series processing with the remote reference technique. The surveyed area is seriously interfered by noise. To improve quality of the data, we perform noise identification and manual selection of the time series segments. Identification of polarization modes is an important task for MT data qualitative interpretation. We apply for a PCA (principal component analysis) based method to automatically identify apparent polarized resistivity curves of TE and TM modes. The method recognizes the distortion and major variation of TE and TM curves and distinguishes the two kinds of curves with principal component analysis. From the apparent resistivity-frequency profile result, we can see that the Chenning Uplift and the Chenjiazhuang Heave reveal a 3-layered structure of medium-low-high, from the shallow to the deep. The structure is especially distinct for the Chenning Uplift, where there is a laterally steady-spreading high- resistivity zone corresponding to the frequency band lower than 1 Hz. The Dongying Sag is characteristic of high-low-medium from the shallow to the deep, and has a low-resistivity anomaly zone with obvious and wide lateral extending in the medium frequency band, which reflects that the deposition thickness of the basin is relatively big. The Guangrao

An African grassland responds similarly to long-term fertilization to the Park Grass experiment.

PubMed

Ward, David; Kirkman, Kevin; Tsvuura, Zivanai

2017-01-01

We compared the results of a long-term (65 years) experiment in a South African grassland with the world's longest-running ecological experiment, the Park Grass study at Rothamsted, U.K. The climate is warm and humid in South Africa and cool and temperate in England. The African grassland has been fertilized with two forms of nitrogen applied at four levels, phosphorus and lime in a crossed design in 96 plots. In 1951, about 84% of plant cover consisted of Themeda triandra, Tristachya leucothrix and Setaria nigrirostris. Currently, the dominant species are Panicum maximum, Setaria sphacelata and Eragrostis curvula, making up 71% of total biomass. As in the Park Grass experiment, we found a significant (additive) interaction effect on ANPP of nitrogen and phosphorus, and a (marginally significant) negative correlation between ANPP and species richness. Unlike the Park Grass experiment, there was no correlation between ANPP and species richness when pH was included as a covariate. There was also a significant negative effect of nitrogen amount and nitrogen form and a positive effect of lime on species richness and species diversity. Soil pH had an important effect on species richness. Liming was insufficient to balance the negative effects on species richness of nitrogen fertilization. There was a significant effect of pH on biomass of three abundant species. There were also significant effects of light on the biomass of four species, with only Panicum maximum having a negative response to light. In all of the abundant species, adding total species richness and ANPP to the model increased the amount of variance explained. The biomass of Eragrostis curvula and P. maximum were negatively correlated with species richness while three other abundant species increased with species richness, suggesting that competition and facilitation were active. Consistent with the results from the Park Grass and other long-term fertilization experiments of grasslands, we found a

MTpy - Python Tools for Magnetotelluric Data Processing and Analysis

NASA Astrophysics Data System (ADS)

Krieger, Lars; Peacock, Jared; Thiel, Stephan; Inverarity, Kent; Kirkby, Alison; Robertson, Kate; Soeffky, Paul; Didana, Yohannes

2014-05-01

We present the Python package MTpy, which provides functions for the processing, analysis, and handling of magnetotelluric (MT) data sets. MT is a relatively immature and not widely applied geophysical method in comparison to other geophysical techniques such as seismology. As a result, the data processing within the academic MT community is not thoroughly standardised and is often based on a loose collection of software, adapted to the respective local specifications. We have developed MTpy to overcome problems that arise from missing standards, and to provide a simplification of the general handling of MT data. MTpy is written in Python, and the open-source code is freely available from a GitHub repository. The setup follows the modular approach of successful geoscience software packages such as GMT or Obspy. It contains sub-packages and modules for the various tasks within the standard work-flow of MT data processing and interpretation. In order to allow the inclusion of already existing and well established software, MTpy does not only provide pure Python classes and functions, but also wrapping command-line scripts to run standalone tools, e.g. modelling and inversion codes. Our aim is to provide a flexible framework, which is open for future dynamic extensions. MTpy has the potential to promote the standardisation of processing procedures and at same time be a versatile supplement for existing algorithms. Here, we introduce the concept and structure of MTpy, and we illustrate the workflow of MT data processing, interpretation, and visualisation utilising MTpy on example data sets collected over different regions of Australia and the USA.

Counseling Groups for African American Women: A Focus on Spirituality.

ERIC Educational Resources Information Center

Williams, Carmen Braun; Frame, Marsha Wiggins; Green, Evelyn

1999-01-01

Explains cultural and spiritual traditions within African American women's experience that form the foundation for group counseling strategies. Reviews literature regarding African American women's experience in groups. Explains group interventions such as art, music, dance, imagery, journaling, and rituals that can help transcend, empower, and…

Crustal deformation of the Andean foreland at 31° 30‧S (Argentina) constrained by magnetotelluric survey

NASA Astrophysics Data System (ADS)

Orozco, Luz Amparo; Favetto, Alicia; Pomposiello, Cristina; Rossello, Eduardo; Booker, John

2013-01-01

Twenty-five new long-period magnetotelluric sites near 31.5°S were collected in a west-east profile. This profile and the previous one, aligned with and adjacent to the eastern end, have been merged to form a single profile of more than 700 km long, extending from the Precordillera to the Chaco-Pampean Plain. The geotectonic scenario is characterized by a modern flat subduction zone of the Nazca plate located at a depth of around 120 km and clearly defined by the distribution of earthquake hypocenters recorded by local and regional networks. A "bulge" shape at 68.5°W, with an anomalous dip to the west, is observed within this segment. The smooth slab deformation might result from the restriction on eastward motion due to the presence of an electrically resistive zone. The magnetotelluric model shows that this thick zone of increased resistivity is found from shallow crustal levels to upper mantle depths. The bulge geometry allows hot fluids and volatiles to rise from the deeper asthenospheric wedge, and reach the lower crust reducing its viscosity and letting it flow. The zones of low resistivity in the lower crust show spatial correlation with the areas of foreland deformation from Precordillera to the Sierras Pampeanas and may also suggest a ductile regime. Shear zones reactivated by Cenozoic faulting must necessarily have their roots in the levels of the ductile lower crust associated to conductive channels. The zone where the lower crust is closer to the surface coincides with the areas of greatest structural relief and erosion. The interface between the folded ductile lower crust and the brittle upper crust might act as the main level of décollement of the bordering structures between the Precordillera, Sierra de Pie de Palo and the Sierras Pampeanas. In addition, the geometry of the interface might be conditioning the vergence of those structures.

The South African Experience of Conservation and Social Forestry Outreach Nurseries

NASA Astrophysics Data System (ADS)

Botha, Jenny; Witkowski, Ed T. F.; Cock, Jacklyn

2006-11-01

Outreach nurseries are favored conservation and social forestry tools globally, but, as with many integrated conservation and development programs (ICDPs), they do not always produce anticipated results. A synopsis of the experience of South African practitioners is provided in this study of 65 outreach nurseries. South African outreach nurseries frequently include financial objectives, creating additional challenges in simultaneously attaining conservation and socioeconomic goals. Progress was hindered by biophysical problems (e.g., lack of water, poor soils, etc.) as well as the harsh socioeconomic conditions facing most communities in which nurseries had been established. Attaining financial viability was challenging. Business management skills were often restricted, and few viability studies included adequate market research. Costs to community participants were usually high, and benefits were limited. Conservation objectives were frequently lost in the struggle to attain financial viability. The management of social processes also proved challenging. Although small scale and relatively straightforward compared with many ICDPs, nurseries usually require substantial institutional support, including a range of technical, business, and development services. Project time frames need to be reconsidered, as practitioners estimate that it takes 5-10 years for nurseries to start meeting objectives, and donors and implementing agencies often operate on 2-3-year project cycles. Detailed viability studies are essential, incorporating a social probe and an assessment of potential impacts of projects on community participants. Progress needs to be continuously evaluated to enable institutions and community participants to adapt to changing conditions as well as ensure that the spectrum of objectives are being achieved.

The South African experience of conservation and social forestry outreach nurseries.

PubMed

Botha, Jenny; Witkowski, Ed T F; Cock, Jacklyn

2006-11-01

Outreach nurseries are favored conservation and social forestry tools globally, but, as with many integrated conservation and development programs (ICDPs), they do not always produce anticipated results. A synopsis of the experience of South African practitioners is provided in this study of 65 outreach nurseries. South African outreach nurseries frequently include financial objectives, creating additional challenges in simultaneously attaining conservation and socioeconomic goals. Progress was hindered by biophysical problems (e.g., lack of water, poor soils, etc.) as well as the harsh socioeconomic conditions facing most communities in which nurseries had been established. Attaining financial viability was challenging. Business management skills were often restricted, and few viability studies included adequate market research. Costs to community participants were usually high, and benefits were limited. Conservation objectives were frequently lost in the struggle to attain financial viability. The management of social processes also proved challenging. Although small scale and relatively straightforward compared with many ICDPs, nurseries usually require substantial institutional support, including a range of technical, business, and development services. Project time frames need to be reconsidered, as practitioners estimate that it takes 5-10 years for nurseries to start meeting objectives, and donors and implementing agencies often operate on 2-3-year project cycles. Detailed viability studies are essential, incorporating a social probe and an assessment of potential impacts of projects on community participants. Progress needs to be continuously evaluated to enable institutions and community participants to adapt to changing conditions as well as ensure that the spectrum of objectives are being achieved.

Surviving oppression under the Rock: The intersection of New York’s drug, welfare, and educational polices in the lived experiences of low-income African-Americans

PubMed Central

Windsor, Liliane Cambraia; Dunlap, Eloise; Armour, Marilyn

2012-01-01

Drawing on standpoint and intersectionality theories, this study explores the degree to which interactions among New York State’s Rockefeller Drug Laws, educational and welfare policies have contributed to the maintenance of a culture of surveillance in which the lives of impoverished African Americans are overseen and influenced by oppressive policies and governmental institutions. Qualitative secondary analysis of longitudinal ethnographic data was conducted. Findings demonstrate multiple disadvantages that impoverished African American families struggling with substance use and/or sale experience. These disadvantages accumulated intergenerationally, in a snowball effect making it difficult for participants to maintain stable lives. Findings explored the tension between participants’ experiences with oppression and the multiple ways they either assimilated or resisted their oppression. New sensitive policies informed by standpoint, intersectionality, and Afrocentric perspectives must be developed to increase the availability of meaningful employment and strengthening impoverished African American communities. PMID:23216440

Magnetotelluric Investigations in Tuwa-Godhra Region, Gujarat (India)

NASA Astrophysics Data System (ADS)

Mohan, Kapil; Chaudhary, Peush; Kumar, G. Pavan; Kothyari, Girish Ch.; Choudhary, Virender; Nagar, Mehul; Patel, Pruthul; Gandhi, Drasti; Kushwaha, Dilip; Rastogi, B. K.

2018-05-01

Magnetotelluric (MT) data have been acquired at 40 locations in Tuwa and its surrounding region (200 km east of Ahmedabad and 15 km north-northwest of Godhra) in the Mainland Gujarat with an average station spacing of 1.5 km. MT impedance tensors have been estimated in the period range of 0.001-100 s. The data have been modeled using non-linear conjugate gradient scheme taking both apparent resistivity and phase into account. From the 2D models of the MT data, the weathered granite with Quaternary sediments (with resistivity of < 700 Ω m) have been inferred up to a depth of 500 m followed by Godhra granite (having resistivity up to 105 Ω m) with a thickness 6.5 km. The Aravalli supergroup has been inferred below Godhra granite. The Lunavada group of rocks have been inferred in the eastern part of the study area (having resistivity value ranging from 103 to 104 Ω m) separated from the Godhra granite by a contact zone. The comparatively very low-resistivity rocks (< 400 Ω m) of Udaipur formation followed by Paleoproterozoic carbonate rocks with fluid have been inferred below 8-10 km depth. The percolation of water from the surface through the contact zone of Lunavada and Champaner groups has been suggested. The presence of hot water springs in 10 km SW from the center of the study area (at the contact zone of Godhra granite and basalt) might be due to the western trending lithostratigraphic slope, hydrostatic pressure generated due to heat produced from interaction of water with the carbonate rocks at deeper depth and high subsurface temperature due to high geothermal gradient. The segmented nature of Himmatnagar Fault (HnF) is identified in the central portion of the study area.

African and Non-African Admixture Components in African Americans and An African Caribbean Population

PubMed Central

Murray, Tanda; Beaty, Terri H.; Mathias, Rasika A.; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U.; Watson, Harold R.; Ruczinski, Ingo; Dunston, Georgia M.; Barnes, Kathleen C.

2013-01-01

Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r2 = 0.992, r2 = 0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on ~14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (FST). We found AAs and ACs were closest genetically (FST = 0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, ~400 well-defined AIMs were just as good for detecting substructure as ~14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

Navigating Race and Cultural Identity: A Phenomenological Study of the Lived Experiences of African American Secondary Principals on the U.S.-Mexico Border of El Paso, Texas

ERIC Educational Resources Information Center

Hill, Natashia J.

2013-01-01

Presently the paucity of scholarship available is often unitary in nature and usually focuses on the lived experiences of African Americans principals in a predominately African American urban context and as well as emphasizes the necessity of same race principals for the purpose of mentorship and racial representation. Race and cultural identity…

"Women...mourn and men carry on": African women storying mourning practices: a South African example.

PubMed

Kotzé, Elmarie; Els, Lishje; Rajuili-Masilo, Ntsiki

2012-09-01

African mourning of loss of lives in South Africa has been shaped by discursive practices of both traditional African cultures and the sociopolitical developments under apartheid and in post-apartheid South Africa. This article reports on changes in mourning practices on the basis of a literature review and uses a collection of examples to highlight the navigation of some cultural and gendered issues relating to mourning, against the backdrop of the everyday experiences of loss of life in South Africa due to violence and HIV/AIDS. The article draws on African womanist and feminist scholarship and focuses on the intersections between cultural and gender practices of bereavement in the lives of professional urban African women. The authors argue for the use of positioning theory and witnessing practices to honor and story the ongoing struggle of African women as these women take different agentic positions by accepting, questioning, resisting, and/or changing cultural mourning practices while they compassionately witness the self and others in the narratives they live.

My American Dream: The Interplay Between Structure and Agency in West African Immigrants' Educational Experiences in the United States

ERIC Educational Resources Information Center

Knight, Michelle G.; Roegman, Rachel; Edstrom, Lisa

2016-01-01

This article presents findings of a qualitative, interpretive case study of the experiences of 1.5- and 2nd-generation West African immigrants who self-identify as pursuing the American Dream, defined by them as academic attainment and career success. Employing structuration theory, the authors examine the interplay between structures and agency…

Geothermal exploration of Kos Island, Greece: Magnetotelluric and microseismicity studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lagios, E.; Tzanis, A.; Delibasis, N.

1994-06-01

This paper reports the results of magnetotelluric (MT) and microseismicity studies, conducted as part of a multi-disciplinary project to explore the geothermal potential of the island of Kos, Greece. The MT survey, comprising 18 soundings, was carried out in the bandwidth 128 Hz-40 s, in order to determine the deep conductivity structure in the geothermally prospective western part of the island, Rigorous dimensionality analysis has indicated that the geoelectric structure could adequately be approximated with 1-D interpretation tools. Two significant and seemingly communicating conductive zones of potential geothermal interest were found within the first 2 km. The first is extensivemore » and shallow, detected at depths of 400--600 m; the second is deeper (1,000--1,300 m), but of considerably smaller lateral dimensions. A very deep relative conductor (< 25 [Omega]m) was also detected at depths of 7--10 km, which is thought to comprise part of an old magma chamber with brine-saturated rocks. The microseismicity studies revealed the partial or total attenuation of shear waves in many microearthquake records. The analysis of these observations determined the vertical and lateral extent of that attenuation zone, the greatest part of which is located underneath the marine area between western Kos and Nissyros island to the south, extending approximately from near the surface to about 1.5 km depth. The nature of this zone is discussed in terms of fluid concentration due to the geothermal system of the area.« less

A Mirror Image African American Student Reflections

ERIC Educational Resources Information Center

Cannon Dawson, Candice

2012-01-01

This dissertation is a narrative inquiry research project that focuses on the collegiate experiences of African American students at both historically black colleges and universities (HBCUs) and predominantly white institutions (PWIs). I look at how African American college students who engage in race or culturally specific activities, the degree…

The relationship between gold ore and geotectonic in West Qinling: Evidence from magnetotelluric soundings

NASA Astrophysics Data System (ADS)

Xu, Daili; Huang, Wei; Zhang, Letian

2017-03-01

The West Qinling belt is the westward extensioin of the Qinling-Dabie-Sulu orogen in central China. It links the Kunlun and Qilian orogens to the west and the Songpan-Ganze belt to the south, making it an important tectonics syntaxis in China. According to the collection and analysis of the data of West Qinling Mountains gold deposit metallogenic chronology, the gold deposits in this area can be divided into five groups by time: 225-245 Ma, 220-190 Ma, 170 Ma±, 135-110 Ma, 75-45 Ma. The formation time is related to the geological process at that time. The relationship between the formation of gold deposit and geological structure can be explored by the research on the present geological structures. According to the regional tectonic evolution and magmatic activity, the gold deposits are divided into four metallogenic epoches: from the end of the Indo-Chinese epoch to the early Yanshanian (245-225 Ma), is one of the initial stages of gold mineralization; the early and the middle Yanshanian (220-190 Ma, 170 Ma±), is the main forming time of the gold mineralization in the West Qinling; the late Yanshanian (135-110 Ma), is the superimposed mineralization stage; at last, the effect of Himalayan hydrothermal activity to the gold deposits. Under the support of three projects naemed " the research on the conductivity of the lithosphere of the Central Orogenic in China ", " the MT array observation of the intersection area of COC(Central Orogen in China) and the North-South seismic belt ", " the experiment research of MT standard network observation in the area of Qinghai-Tibetan Plateau and the North-China " (Sinoprobe-01-02), we collected massive magnetotellurics data for futher study of the present geological strusctures to discess the relationship between gold deposites and geotectonic in West Qinling.

Detection and characterization of cultural noise sources in magnetotelluric data: individual and joint analysis of the polarization attributes of the electric and magnetic field time-series in the time-frequency domain

NASA Astrophysics Data System (ADS)

Escalas, M.; Queralt, P.; Ledo, J.; Marcuello, A.

2012-04-01

Magnetotelluric (MT) method is a passive electromagnetic technique, which is currently used to characterize sites for the geological storage of CO2. These later ones are usually located nearby industrialized, urban or farming areas, where man-made electromagnetic (EM) signals contaminate the MT data. The identification and characterization of the artificial EM sources which generate the so-called "cultural noise" is an important challenge to obtain the most reliable results with the MT method. The polarization attributes of an EM signal (tilt angle, ellipticity and phase difference between its orthogonal components) are related to the character of its source. In a previous work (Escalas et al. 2011), we proposed a method to distinguish natural signal from cultural noise in the raw MT data. It is based on the polarization analysis of the MT time-series in the time-frequency domain, using a wavelet scheme. We developed an algorithm to implement the method, and was tested with both synthetic and field data. In 2010, we carried out a controlled-source electromagnetic (CSEM) experiment in the Hontomín site (the Research Laboratory on Geological Storage of CO2 in Spain). MT time-series were contaminated at different frequencies with the signal emitted by a controlled artificial EM source: two electric dipoles (1 km long, arranged in North-South and East-West directions). The analysis with our algorithm of the electric field time-series acquired in this experiment was successful: the polarization attributes of both the natural and artificial signal were obtained in the time-frequency domain, highlighting their differences. The processing of the magnetic field time-series acquired in the Hontomín experiment has been done in the present work. This new analysis of the polarization attributes of the magnetic field data has provided additional information to detect the contribution of the artificial source in the measured data. Moreover, the joint analysis of the

Magnetotelluric imaging of the crustal structure of the Great Slave Lake shear zone in Northwest Alberta

NASA Astrophysics Data System (ADS)

WANG, E.; Unsworth, M. J.; Chacko, T.

2017-12-01

The Alberta basement is part of the North American craton - Laurentia, which was assembled in the Paleoproterozoic era. The Great Slave Lake shear zone (GSLsz) is the major crustal-scale right-lateral strike-slip feature in northwest Laurentia. Because of the extensive coverage of the rocks of the WCSB, geological studies in northern Alberta are limited to studies of drill core samples. The crustal structures of northern Alberta were defined from potential field in combination with isotopic studies. Magnetotelluric method is helpful in this case, because it is sensitive to conductive bodies. New Broadband magnetotelluric data were collected across the GSLsz to give a clear image of the crustal structure. Dimensionality analyses showed that the data are two-dimensional at the crustal depth, even though 3-D effects are present at the lowest frequencies. Consequently, 2-D inversions were applied and a preferred resistivity model was achieved. The WCSB was imaged as a conductive layer on the top of the resistive Precambrian basement rocks. Four conductive bodies associate with terrane boundaries were identified. The largest conductor - KC is located coincident with the Kiskatinaw terrane at the mid-crustal depth. The second conductor - KCC is located at the boundary of the Ksituan and Chinchaga terranes at upper-crustal depth. The KC and KCC are suspected to be linear conductors that are consistent along the strikes of the Kiskatinaw terrane and the western boundary of the Chinchaga terrane, respectively. This is concluded when considering the result of this study in combination with the potential field data, a previously proposed 3-D resistivity model and a 2-D seismic reflection result. Both of the KC and KCC corresponds to seismically reflective zones. The third conductor - HC is imaged beneath the Hottah terrane. The GSLsz is close to the HC and they may be related in origin. The fourth conductor - CBHC is imaged at the boundary of the Chinchaga and Buffalo Head

Negotiating Worlds, Managing Subjectivities, and Redefining Selves: The Lived Experiences of African American Undergraduate Females at Predominately White Institutions

ERIC Educational Resources Information Center

Allen, Ayana Ma-el

2010-01-01

A narrative analysis of the lived experiences of seven undergraduate African American females at Predominately White Institutions (PWIs) is presented in this study. The purpose of the study was to explore the ways the seven women constructed their identity and self-concept in the context of their PWI environment. Other key purposes of the study…

Moving Heaven and Earth: Administrative Search and Selection Processes and the Experience of an African American Woman Senior Administrator

ERIC Educational Resources Information Center

Barnett-Johnson, Kim R.

2009-01-01

The purpose of this case/phenomenological study was to examine a collegiate administrative search and selection process and the experience of an African American woman who was selected to the position of chancellor. A case concerning the search process of a regional campus of Ivy Tech Community College of Indiana was identified and chosen.…

Sex-Role Egalitarian Attitudes and Gender Role Socialization Experiences of African American Men and Women: A Mixed Methods Paradigm

ERIC Educational Resources Information Center

Heard, Courtney Christian Charisse

2013-01-01

The purpose of this study was to assess the sex-role egalitarian attitudes and gender role socialization experiences of African American men and women. A sequential mixed-methods design was employed to research this phenomenon. The Sex-Role Egalitarianism Scale-Short Form BB (SRES-BB) was utilized to assess sex-role egalitarian attitudes (King…

"It's Not Like a Job Now; It's Part of Me": Exploring African Women's Experiences in the Irish Childcare Sector

ERIC Educational Resources Information Center

Garrity, Sheila; McGrath, Brian

2011-01-01

A small-scale qualitative research study was recently carried out in the West of Ireland to explore the experiences of African childminders who had established new childcare services. The intention of the study was to explore the issues, concerns and challenges of this group of providers given their unique position as recently settled, ethnic…

Teaching White Students Black History: The African-American Experience in the Classroom

ERIC Educational Resources Information Center

Burrell, Leon F.; Walsh, Robert L.

2001-01-01

Many white students are barely exposed to African-American history throughout their schooling. When students do examine the other side of American history, the one not generally found in their textbooks, they often wonder why they have not learned this before. An understanding of African-American history is central to any effort to eliminate…

Recommendations for the Use of Online Social Support for African American Men

PubMed Central

Watkins, Daphne C.; Jefferson, S. Olivia

2014-01-01

African American men face greater psychosocial stressors than African American women and men of other racial and ethnic groups, which place them at higher risk for psychological distress. Yet, research suggests that African Americans are less likely to utilize professional mental health services because of their mistrust of the health care system and their need for more specialized and innovative services. Supplemental resources aimed at positive coping and social support for African American men may reduce the likelihood that they experience psychological distress, which could lead to more severe mental disorders. This article proposes the use of online social support for African American men who are in early, nonsevere stages of psychological distress. We examine the unique experiences of African American men, discuss distress among this underserved group, and finally, offer recommendations for achieving an online community for African American men. PMID:22924797

The role of social support in the psychological well-being of African American girls who experience dating violence victimization.

PubMed

Salazar, Laura F; Wingood, Gina M; DiClemente, Ralph J; Lang, Delia L; Harrington, Kathy

2004-04-01

The goals of this study were to test the relationship between dating violence victimization (i.e., verbal, emotional, and physical abuse) and psychological well-being (i.e., depressive symptomatology, self-esteem, and body image) among 522 African American girls, and to determine whether social support acted as a buffer of negative effects (moderator) or as an intervening factor (mediator) in the relationship between dating violence victimization and psychological well-being. Results from structural equation modeling indicated that dating violence victimization was associated with negative psychological outcomes. Although social support did not moderate this relationship, it served as a mediator of the relationship between dating violence victimization and psychological well-being. Dating violence programs for African American girls should consider how to incorporate family, church, and other networks in the community to foster support, and allow adolescent girls to discuss their abusive experiences in a nonblaming environment. If programs are able to buoy girls who experience dating violence, then they may be able to ameliorate the associated negative psychological sequelae.

African American women's preventative care usage: the role of social support and racial experiences and attitudes.

PubMed

Pullen, Erin; Perry, Brea; Oser, Carrie

2014-09-01

Research suggests that African Americans are less likely to utilise preventative care services than Americans of European descent, and that these patterns may contribute to racial health disparities in the United States. Despite the persistence of inequalities in preventative care utilisation, culturally relevant factors influencing the use of these gateway health services have been understudied among marginalised groups. Using a stratified sample of 205 low-income African American women, this research examines the predictors of receiving a physical exam, with a particular emphasis on how differing levels of social support from friend and family networks and experiences of racial discrimination and cultural mistrust shape utilisation. The findings underscore the importance of traditional predictors of utilisation, including insurance status and having a usual physician. However, they also indicate that supportive ties to friendship networks are associated with higher predicted rates of having an annual physical exam, while social support from family and sentiments of cultural mistrust are associated with lower rates of utilisation. Broadly, the findings indicate that even as traditional predictors of help-seeking become less relevant, it will be critical to explore how variations in discrimination experiences and social relationships across marginalised groups drive patterns of preventative care utilisation. © 2014 The Authors. Sociology of Health & Illness © 2014 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

African-American Women's Experiences in Graduate Science, Technology, Engineering, and Mathematics Education at a Predominantly White University: A Qualitative Investigation

ERIC Educational Resources Information Center

Alexander, Quentin R.; Hermann, Mary A.

2016-01-01

In this phenomenological investigation we used qualitative research methodology to examine the experiences of 8 African American women in science, technology, engineering, and mathematics (STEM) graduate programs at 1 predominantly White university (PWU) in the South. Much of the current research in this area uses quantitative methods and only…

Joint interpretation of seismic tomography and new magnetotelluric results provide evidence for support of high topography in the Southern Rocky Mountains and High Plains of eastern Colorado, USA

NASA Astrophysics Data System (ADS)

Feucht, D. W.; Sheehan, A. F.; Bedrosian, P.

2015-12-01

A recent magnetotelluric (MT) survey in central Colorado, USA, when interpreted alongside existing seismic tomography, reveals potential mechanisms of support for high topography both regionally and locally. Broadband and long period magnetotelluric data were collected at twenty-three sites along a 330 km E-W profile across the Southern Rocky Mountains and High Plains of central North America as part of the Deep RIFT Electrical Resistivity (DRIFTER) experiment. Remote-reference data processing yielded high quality MT data over a period range of 100 Hz to 10,000 seconds. A prominent feature of the regional geo-electric structure is the Denver Basin, which contains a thick package of highly conductive shales and porous sandstone aquifers. One-dimensional forward modeling was performed on stations within the Denver Basin to estimate depth to the base of this shallow conductor. Those estimates were then used to place a horizontal penalty cut in the model mesh of a regularized two-dimensional inversion. Two-dimensional modeling of the resistivity structure reveals two major anomalous regions in the lithosphere: 1) a high conductivity region in the crust under the tallest peaks of the Rocky Mountains and 2) a lateral step increase in lithospheric resistivity beneath the plains. The Rocky Mountain crustal anomaly coincides with low seismic wave speeds and enhanced heat flow and is thus interpreted as evidence of partial melt and/or high temperature fluids emplaced in the crust by tectonic activity along the Rio Grande Rift. The lateral variation in the mantle lithosphere, while co-located with a pronounced step increase in seismic velocity, appears to be a gradational boundary in resistivity across eastern Colorado and could indicate a small degree of compositional modification at the edge of the North American craton. These inferred conductivity mechanisms, namely crustal melt and modification of mantle lithosphere, likely contribute to high topography locally in the

Audio-magnetotelluric (AMT) study to investigate the genesis of Mujil hill

NASA Astrophysics Data System (ADS)

Rahmania, Suryanto, Wiwit

2017-07-01

Gunung Mujil is an isolated hill located near Pondoworejo village, Kalibawang sub-district, Kulon Progo district, and Special Province of Yogyakarta. The hill is part of the eastern Kulon Progo mountain range extended relatively in the North-South direction. The lithology of the hill consists of andesite breccia and it's similar with the Old Andesite Formation that built the Kulon Progo Mountains. There are at least two hypothesis about the genesis and the formation mechanism of this hill, (1) it was formed by debris mass from Kulon Progo Mountains, and (2) ) it was formed by an intrusion. Our study intended to determine the subsurface resistivity below the hill and to relating those results to with the scenario of the genesis of the Mujil hill. We conducted Audio-magnetotellurics (AMT) measurements along two lines survey crossing the Mujil hill consisting of 20 measurements. Since the measurements are located near the villages, most of the data has a fair to bad quality and only one station yielded an excellent data. A 1D Forward modeling was then applied to find best-fit model of the AMT data. The results shows that the Mujil hill was built by debris mass of the Old Andesite Formation from Kulon Progo mountain which is represented by a lower resistivity value under the Mujil hill.

African Americans in bereavement: grief as a function of ethnicity.

PubMed

Laurie, Anna; Neimeyer, Robert A

2008-01-01

Few empirical studies have explored the grieving process among different ethnic groups within the United States, and very little is known about how African Americans and Caucasians may differ in their experience of loss. The purpose of this study was to examine the African-American experience of grief, with particular emphasis on issues of identity change, interpersonal dimensions of the loss, and continuing attachments with the deceased. Participants were 1,581 bereaved college students (940 Caucasians and 641 African Americans) attending classes at a large southern university. Each participant completed the Inventory of Complicated Grief-Revised, the Continuing Bonds Scale, and questions regarding the circumstances surrounding his or her loss. Results revealed that African Americans experienced more frequent bereavement by homicide, maintenance of a stronger continuing bond with the deceased, greater grief for the loss of extended kin beyond the immediate family, and a sense of support in their grief, despite their tendency to talk less with others about the loss or seek professional support for it. Overall, African Americans reported higher levels of complicated grief symptoms than Caucasians, especially when they spent less time speaking to others about their loss experience. Implications of these findings for bereavement support services for African Americans were briefly noted.

'Walk with your head high': African and African-Caribbean fatherhood, children's mental well-being and social capital.

PubMed

Williams, Robert; Hewison, Alistair; Wagstaff, Chris; Randall, Duncan

2012-01-01

The findings presented in this article were unanticipated and came to light during a study which investigated African and African-Caribbean fathers' views about preventive primary care services. This article reports findings which indicate that African and African-Caribbean fathers strive to enable and protect children's mental well-being and create social, cultural and symbolic forms of capital. It also seeks to identify implications for health and social care policy and practice in England. There is limited literature examining African and African-Caribbean fathers' health experiences in England. Consequently an exploratory research approach was required. This involved nine, in-depth, semi-structured qualitative group interviews undertaken with 46 African and African-Caribbean fathers. The data were analysed thematically using abductive reasoning, informed by Bourdieu's theoretical work. Fathers were striving to enable and protect children's mental well-being through providing authoritative, loving, affectionate fatherhood involving reasoning, good communication and promoting self-esteem. These practices were seen to be necessary if children were to prosper in a harsh social world characterised by structural hazards including racism, negative stereotypes and limited opportunities. The fathers reported their efforts to develop what Bourdieu has termed symbolic, cultural and social capital as means of promoting the mental well-being of their children and the children of others. The implications for theory, future research, public health policy and practice, in relation to the needs of African and African-Caribbean fathers and families, are also discussed, with specific focus on how to realise the potential of African and African-Caribbean fathers' positive contributions to family and community health.

Crustal structure of an intraplate thrust belt: The Iberian Chain revealed by wide-angle seismic, magnetotelluric soundings and gravity data

NASA Astrophysics Data System (ADS)

Seillé, Hoël; Salas, Ramon; Pous, Jaume; Guimerà, Joan; Gallart, Josep; Torne, Montserrat; Romero-Ruiz, Ivan; Diaz, Jordi; Ruiz, Mario; Carbonell, Ramon; Mas, Ramón

2015-11-01

The Iberian Chain is a Cenozoic intraplate thrust belt located within the Iberian plate. Unlike other belts in the Iberia Peninsula, the scarcity of geophysical studies in this area results in a number of unknowns about its crustal structure. The Iberian Chain crust was investigated by means of a NE-SW refraction/wide-angle reflection seismic transect and two magnetotelluric profiles across the chain, oriented along the same direction. The seismic profile was designed to sample the crust by means of three shots designed to obtain a reversed profile. The resulting velocity-depth model shows a moderate thickening of the crust toward the central part of the profile, where crustal thickness reaches values above 40 km, thinning toward de SW Tajo and NE Ebro foreland basins. The crustal thickening is concentrated in the upper crust. The seismic results are in overall agreement with regional trends of Bouguer gravity anomaly and the main features of the seismic model were reproduced by gravity modeling. The magnetotelluric data consist of 39 sites grouped into two profiles, with periods ranging from 0.01 s to 1000 s. Dimensionality analyses show significant 3D effects in the resistivity structure and therefore we carried out a joint 3D inversion of the full impedance tensor and magnetic transfer functions. The Mesozoic and Cenozoic basins along the Chain are well characterized by shallow high conductive zones and low velocities. Elongated conductors reaching mid-crustal depths evidence the presence of major faults dominating the crustal structure. The results from the interpretation of these complementary geophysical data sets provided the first images of the crustal structure of the Iberian Chain. They are consistent with a Cenozoic shortening responsible of the upper crust thickening as well as of the uplift of the Iberian Chain and the generation of its present day topography.

Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models

USGS Publications Warehouse

Bedrosian, P.A.; Maercklin, N.; Weckmann, U.; Bartov, Y.; Ryberg, T.; Ritter, O.

2007-01-01

Magnetotelluric and seismic methods provide complementary information about the resistivity and velocity structure of the subsurface on similar scales and resolutions. No global relation, however, exists between these parameters, and correlations are often valid for only a limited target area. Independently derived inverse models from these methods can be combined using a classification approach to map geologic structure. The method employed is based solely on the statistical correlation of physical properties in a joint parameter space and is independent of theoretical or empirical relations linking electrical and seismic parameters. Regions of high correlation (classes) between resistivity and velocity can in turn be mapped back and re-examined in depth section. The spatial distribution of these classes, and the boundaries between them, provide structural information not evident in the individual models. This method is applied to a 10 km long profile crossing the Dead Sea Transform in Jordan. Several prominent classes are identified with specific lithologies in accordance with local geology. An abrupt change in lithology across the fault, together with vertical uplift of the basement suggest the fault is sub-vertical within the upper crust. ?? 2007 The Authors Journal compilation ?? 2007 RAS.

3-D interpretation of short-period magnetotelluric data at Furnas Volcano, Azores Islands

NASA Astrophysics Data System (ADS)

Hogg, C.; Kiyan, D.; Rath, V.; Byrdina, S.; Vandemeulebrouck, J.; Revil, A.; Viveiros, F.; Carmo, R.; Silva, C.; Ferreira, T.

2018-04-01

Accurate geophysical imaging of shallow subsurface features provides crucial constraints on understanding the dynamics of volcanic systems. At Furnas Volcano (Azores), intense circulation of volcanic fluids at depth leading to high CO2 outgassing and flank destabilization poses considerable threat to the local population. Presented is a novel 3-D electrical resistivity model developed from 39 magnetotelluric soundings that images the hydrothermal system of the Furnas Volcano to a depth of 1 km. The resistivity model images two conductive zones, one at 100 m and another at 500 m depth, separated by a resistive layer. The shallow conductor has conductivity less than 1 S m-1, which can be explained by clay mineral surface conduction with a mass fraction of at least 20 per cent smectite. The deeper conductor extends across the majority of the survey area. This deeper conductor is located at depths where smectite is generally replaced by chlorite and we interpret it as aqueous fluids near the boiling point and infer temperatures of at least 240 °C. The less conductive layer found between these conductors is probably steam-dominated, and coincides within the mixed-clay zone found in many volcanic hydrothermal systems.

A Phenomenological Study: African-American Males in the Educational Profession

ERIC Educational Resources Information Center

Williams, Kristopher

2012-01-01

This phenomenological research study explored the perceptions and lived experiences of African-American male teachers related to the underrepresentation of African-American males in the teaching profession. The study was guided by four research questions. The data was collected from 15 African-American male teachers at the elementary school level,…

Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform

USGS Publications Warehouse

Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

2005-01-01

Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

Conservation lessons from large-mammal manipulations in East African savannas: the KLEE, UHURU, and GLADE experiments.

PubMed

Goheen, Jacob R; Augustine, David J; Veblen, Kari E; Kimuyu, Duncan M; Palmer, Todd M; Porensky, Lauren M; Pringle, Robert M; Ratnam, Jayashree; Riginos, Corinna; Sankaran, Mahesh; Ford, Adam T; Hassan, Abdikadir A; Jakopak, Rhiannon; Kartzinel, Tyler R; Kurukura, Samson; Louthan, Allison M; Odadi, Wilfred O; Otieno, Tobias O; Wambua, Alois M; Young, Hillary S; Young, Truman P

2018-05-11

African savannas support an iconic fauna, but they are undergoing large-scale population declines and extinctions of large (>5 kg) mammals. Long-term, controlled, replicated experiments that explore the consequences of this defaunation (and its replacement with livestock) are rare. The Mpala Research Centre in Laikipia County, Kenya, hosts three such experiments, spanning two adjacent ecosystems and environmental gradients within them: the Kenya Long-Term Exclosure Experiment (KLEE; since 1995), the Glade Legacies and Defaunation Experiment (GLADE; since 1999), and the Ungulate Herbivory Under Rainfall Uncertainty experiment (UHURU; since 2008). Common themes unifying these experiments are (1) evidence of profound effects of large mammalian herbivores on herbaceous and woody plant communities; (2) competition and compensation across herbivore guilds, including rodents; and (3) trophic cascades and other indirect effects. We synthesize findings from the past two decades to highlight generalities and idiosyncrasies among these experiments, and highlight six lessons that we believe are pertinent for conservation. The removal of large mammalian herbivores has dramatic effects on the ecology of these ecosystems; their ability to rebound from these changes (after possible refaunation) remains unexplored. © 2018 New York Academy of Sciences.

Experimental characterization of West African Newcastle disease virus

USDA-ARS?s Scientific Manuscript database

Four West African strains and one South African strain of virulent Newcastle disease virus (NDV) were characterized through a two-phase experiment. Strains investigated were Burkina Faso/2415-580/2008, Nigeria/228-7/2006, Niger/1377/2006, and Goose/South Africa/08100426/2008. Phylogenetic analysis s...

Challenges associated with tracking resources allocation for reproductive health in sub-Saharan African countries: the UNFPA/NIDI resource flows project experience.

PubMed

Sidze, Estelle M; Beekink, Erik; Maina, Beatrice W

2015-05-05

Universal access to reproductive health services entails strengthening health systems, but requires significant resource commitments as well as efficient and effective use of those resources. A number of international organizations and governments in developing countries are putting efforts into tracking the flow of health resources in order to inform resource mobilization and allocation, strategic planning, priority setting, advocacy and general policy making. The UNFPA/NIDI-led Resource Flows Project ("The UNFPA/NIDI RF Project") has conducted annual surveys since 1997 to monitor progress achieved by developing countries in implementing reproductive health financial targets. This commentary summarizes the Project experiences and challenges in gathering data on allocation of resources for reproductive health at the domestic level in sub-Saharan African countries. One key lesson learnt from the Project experience is the need for strengthening tracking mechanisms in sub-Saharan African countries and making information on reproductive health resources and expenditures available, in particular the private sector resources.

Local Villages and Global Networks: The Language and Migration Experiences of African Skilled Migrant Academics

ERIC Educational Resources Information Center

Hurst, Ellen

2017-01-01

African skilled migrants and their circular and return migration strategies have received relatively little attention in the literature, with the previous focus of much African migration literature being on the net loss of skills to countries with developed economies in the global north. This article considers 13 interviews with African skilled…

African American Students' Persistence at a Two-Year Institution: Cognitive, Social, and Institutional Experiences

ERIC Educational Resources Information Center

Hill, Angela Jewell

2017-01-01

Persistence and graduation rates of African American students have become discussion topics of national, state, and educational leaders (U.S. Department of Education, 2012). Many African American students enroll in postsecondary education but do not persist to graduation (Harris, 2016). The purpose of this study was to explore African American…

African American Elders' Serious Illness Experiences: Narratives of "God Did," "God Will," and "Life Is Better".

PubMed

Coats, Heather; Crist, Janice D; Berger, Ann; Sternberg, Esther; Rosenfeld, Anne G

2017-04-01

The foundation of culturally sensitive patient-centered palliative care is formed from one's social, spiritual, psychological, and physical experiences of serious illness. The purpose of this study was to describe categories and patterns of psychological, social, and spiritual healing from the perspectives of aging seriously ill African American (AA) elders. Using narrative analysis methodology, 13 open-ended interviews were collected. Three main patterns were "prior experiences," "I changed," and "across past, present experiences and future expectations." Themes were categorized within each pattern: been through it . . . made me strong, I thought about . . . others, went down little hills . . . got me down, I grew stronger, changed priorities, do things I never would have done, quit doing, God did and will take care of me, close-knit relationships, and life is better. "Faith" in God helped the aging seriously ill AA elders "overcome things," whether their current illness or other life difficulties.

The Impact of African American Parents’ Racial Discrimination Experiences and Perceived Neighborhood Cohesion on their Racial Socialization Practices

PubMed Central

English, Devin; Busby, Danielle R.; Lambert, Sharon F.; Harrison, Aubrey; Stock, Michelle L.; Gibbons, Frederick X.

2016-01-01

Parental racial socialization is a parenting tool used to prepare African American adolescents for managing racial stressors. While it is known that parents’ racial discrimination experiences affect the racial socialization messages they provide, little is known about the influence of factors that promote supportive and communal parenting, such as perceived neighborhood cohesion. In cohesive neighborhoods, neighbors may help parents address racial discrimination by monitoring youth and conveying racial socialization messages; additionally, the effect of neighborhood cohesion on parents’ racial socialization may differ for boys and girls because parents socialize adolescents about race differently based on expected encounters with racial discrimination. Therefore, the current study examines how parents’ perception of neighborhood cohesion and adolescents’ gender moderate associations between parents’ racial discrimination experiences and the racial socialization messages they deliver to their adolescents. Participants were a community sample of 608 African American adolescents (54 % girls; mean age = 15.5) and their primary caregivers (86 % biological mothers; mean age = 42.0). Structural equation modeling indicated that parental racial discrimination was associated with more promotion of mistrust messages for boys and girls in communities with low neighborhood cohesion. In addition, parental racial discrimination was associated with more cultural socialization messages about racial pride and history for boys in neighborhoods with low neighborhood cohesion. The findings suggest that parents’ racial socialization messages are influenced by their own racial discrimination experiences and the cohesiveness of the neighborhood; furthermore, the content of parental messages delivered varies based on adolescents’ gender. PMID:27189721

African-Canadian Educators' Perspectives: Critical Factors for Success

ERIC Educational Resources Information Center

Finlayson, Maureen

2011-01-01

This study investigates the perspectives of African-Canadian educators on critical factors for success in their educational careers. Interviews were conducted and life histories were constructed to analyze the complex and multifaceted nature of the experiences of ten African-Canadian educators. These data indicate that family and community…

Diagnosing GCM errors over West Africa using relaxation experiments. Part II: intraseasonal variability and African easterly waves

NASA Astrophysics Data System (ADS)

Pohl, Benjamin; Douville, Hervé

2011-10-01

A near-global grid-point nudging of the Arpege-Climat atmospheric General Circulation Model towards ECMWF reanalyses is used to diagnose the regional versus remote origin of the summer model biases and variability over West Africa. First part of this study revealed a limited impact on the monsoon climatology compared to a control experiment without nudging, but a significant improvement of interannual variability, although the amplitude of the seasonal anomalies remained underestimated. Focus is given here on intraseasonal variability of monsoon rainfall and dynamics. The reproducible part of these signals is investigated through 30-member ensemble experiments computed for the 1994 rainy season, a year abnormally wet over the Sahel but representative of the model systematic biases. In the control experiment, Arpege-Climat simulates too few rainy days that are associated with too low rainfall amounts over the central and western Sahel, in line with the seasonal dry biases. Nudging the model outside Africa tends to slightly increase the number of rainy days over the Sahel, but has little effect on associated rainfall amounts. However, results do indicate that a significant part of the monsoon intraseasonal variability simulated by Arpege-Climat is controlled by lateral boundary conditions. Parts of the wet/dry spells over the Sahel occur in phase in the 30 members of the nudging experiment, and are therefore embedded in larger-scale variability patterns. Inter-member spread is however not constant across the selected summer season. It is partly controlled by African Easterly Waves, which show dissimilar amplitude from one member to another, but a coherent phasing in all members. A lowpass filtering of the nudging fields suggests that low frequency variations in the lateral boundary conditions can lead to eastward extensions of the African Easterly Jet, creating a favorable environment for easterly waves, while high frequency perturbations seem to control their

Three-dimensional electrical resistivity model of the hydrothermal system in Long Valley Caldera, California, from magnetotellurics

USGS Publications Warehouse

Peacock, Jared R.; Mangan, Margaret T.; McPhee, Darcy K.; Wannamaker, Phil E.

2016-01-01

Though shallow flow of hydrothermal fluids in Long Valley Caldera, California, has been well studied, neither the hydrothermal source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic system and modeled in 3-D. The preferred electrical resistivity model suggests that the source reservoir is a narrow east-west elongated body 4 km below the west moat. The heat source could be a zone of 2–5% partial melt 8 km below Deer Mountain. Additionally, a collection of hypersaline fluids, not connected to the shallow hydrothermal system, is found 3 km below the medial graben, which could originate from a zone of 5–10% partial melt 8 km below the south moat. Below Mammoth Mountain is a 3 km thick isolated body containing fluids and gases originating from an 8 km deep zone of 5–10% basaltic partial melt.

Two-dimensional magnetotelluric inversion using reflection seismic data as constraints and application in the COSC project

NASA Astrophysics Data System (ADS)

Yan, Ping; Kalscheuer, Thomas; Hedin, Peter; Garcia Juanatey, Maria A.

2017-04-01

We present a novel 2-D magnetotelluric (MT) inversion scheme, in which the local weights of the regularizing smoothness constraints are based on the envelope attribute of a reflection seismic image. The weights resemble those of a previously published seismic modification of the minimum gradient support method. We measure the directional gradients of the seismic envelope to modify the horizontal and vertical smoothness constraints separately. Successful application of the inversion to MT field data of the Collisional Orogeny in the Scandinavian Caledonides (COSC) project using the envelope attribute of the COSC reflection seismic profile helped to reduce the uncertainty of the interpretation of the main décollement by demonstrating that the associated alum shales may be much thinner than suggested by a previous inversion model. Thus, the new model supports the proposed location of a future borehole COSC-2 which is hoped to penetrate the main décollement and the underlying Precambrian basement.

Engaging African American Faith-Based Organizations in Adolescent HIV Prevention.

PubMed

Woods-Jaeger, Briana A; Carlson, Mamie; Taggart, Tamara; Riggins, Linda; Lightfoot, Alexandra F; Jackson, Melvin R

2015-08-01

To reduce current HIV disparities among African American youth, it is imperative to find effective ways to extend the reach of evidence-based HIV prevention. One promising community resource to support this effort is faith-based organizations (FBOs), a credible and respected resource in the African American community. This paper describes the experiences, perceptions, and challenges that African American FBOs and faith leaders face in engaging in adolescent HIV prevention and highlights facilitators and barriers to implementing HIV prevention in African American FBOs. The findings suggest that African American FBOs and faith-based leaders are uniquely positioned to be instrumental resources in reducing African American youth HIV disparities.

African American Students' Experiences in Special Education Programs

ERIC Educational Resources Information Center

Craft, Eleanor; Howley, Aimee

2018-01-01

Background/Context: Disproportionate placement of African American students into special education programs is likely to be a form of institutional racism, especially when such placement stigmatizes students. If placement also fails to lead to educational benefits, the practice becomes even more suspect. Some studies have explored disproportionate…

Investigating collapse structures in oceanic islands using magnetotelluric surveys: The case of Fogo Island in Cape Verde

NASA Astrophysics Data System (ADS)

Martínez-Moreno, F. J.; Monteiro Santos, F. A.; Madeira, J.; Pous, J.; Bernardo, I.; Soares, A.; Esteves, M.; Adão, F.; Ribeiro, J.; Mata, J.; Brum da Silveira, A.

2018-05-01

One of the most remarkable natural events on Earth are the large lateral flank collapses of oceanic volcanoes, involving volumes of rock exceeding tens of km3. These collapses are relatively frequent in recent geological times as supported by evidence found in the geomorphology of volcanic island edifices and associated debris flows deposited on the proximal ocean floor. The Island of Fogo in the Cape Verde archipelago is one of the most active and prominent oceanic volcanoes on Earth. The island has an average diameter of 25 km and reaches a maximum elevation of 2829 m above sea level (m a.s.l.) at Pico do Fogo, a young stratovolcano located within a summit depression open eastward due to a large lateral flank collapse. The sudden collapse of the eastern flank of Fogo Island produced a megatsunami 73 ky ago. The limits of the flank collapse were deduced as well from geomorphologic markers within the island. The headwall of the collapse scar is interpreted as either being located beneath the post-collapse volcanic infill of the summit depression or located further west, corresponding to the Bordeira wall that partially surrounds it. The magnetotelluric (MT) method provides a depth distribution of the ground resistivity obtained by the simultaneous measurement of the natural variations of the electric and magnetic field of the Earth. Two N-S magnetotelluric profiles were acquired across the collapsed area to determine its geometry and boundaries. The acquired MT data allowed the determination of the limits of the collapsed area more accurately as well as its morphology at depth and thickness of the post-collapse infill. According to the newly obtained MT data and the bathymetry of the eastern submarine flank of Fogo, the volume involved in the flank collapse is estimated in 110 km3. This volume -the first calculated onshore- stands between the previously published more conservative and excessive calculations -offshore- that were exclusively based in geomorphic

Breastfeeding support for African-American women in Louisiana hospitals.

PubMed

Gee, Rebekah E; Zerbib, Lauren D; Luckett, Brian G

2012-12-01

This study determined the variation in hospital breastfeeding support for African-American women in Louisiana. Data from the 2007-2008 Louisiana Pregnancy Risk Assessment Monitoring System (n=2,534) were used to determine the odds of African-American women's hospital experiences with breastfeeding-related services following delivery relative to women of all other races. SAS-callable SUDDAN software was used for analyses. African-American women were 60% less likely than women of other races to initiate breastfeeding or pump milk (odds ratio=0.40, 95% confidence interval=0.31-0.52). Compared with women of other races, African-American mothers were less likely to receive breastfeeding instruction and support from healthcare professionals while in the hospital, including being less likely to receive phone numbers for support and less likely to have their baby remain in the hospital room with them. African-American mothers were also less likely to report that they breastfed while in-hospital or breastfed exclusively while in-hospital. This study shows significant racial differences in initiation of breastfeeding and hospital experiences following delivery in Louisiana.

Annotated Selected Bibliography & Index for Teaching African-American Learners: Culturally Responsive Pedagogy Project.

ERIC Educational Resources Information Center

Hilliard, Asa G.

This annotated bibliography and index presents nearly 2,000 references that are substantially unique to African or African American teaching and learning. Designed to support teacher education, the bibliography features references that were chosen if they were culturally relevant, recognized the African or African American experience, and drew…

A qualitative study on African immigrant and refugee families' experiences of accessing primary health care services in Manitoba, Canada: it's not easy!

PubMed

Woodgate, Roberta Lynn; Busolo, David Shiyokha; Crockett, Maryanne; Dean, Ruth Anne; Amaladas, Miriam R; Plourde, Pierre J

2017-01-09

Immigrant and refugee families form a growing proportion of the Canadian population and experience barriers in accessing primary health care services. The aim of this study was to examine the experiences of access to primary health care by African immigrant and refugee families. Eighty-three families originating from 15 African countries took part in multiple open ended interviews in western Canada. Qualitative data was collected in six different languages between 2013 and 2015. Data analysis involved delineating units of meaning from the data, clustering units of meaning to form thematic statements, and extracting themes. African immigrant and refugee families experienced challenges in their quest to access primary health care that were represented by three themes: Expectations not quite met, facing a new life, and let's buddy up to improve access. On the theme of expectations not quite met, families struggled to understand and become familiar with a new health system that presented with a number of barriers including lengthy wait times, a shortage of health care providers, high cost of medication and non-basic health care, and less than ideal care. On the theme of facing a new life, immigrant and refugee families talked of the difficulties of getting used to their new and unfamiliar environments and the barriers that impact their access to health care services. They talked of challenges related to transportation, weather, employment, language and cultural differences, and lack of social support in their quest to access health care services. Additionally, families expressed their lack of social support in accessing care. Privately sponsored families and families with children experienced even less social support. Importantly, in the theme of let's buddy up to improve access, families recommended utilizing networking approaches to engage and improve their access to primary health care services. African immigrant and refugee families experience barriers to accessing

The Amistad Research Center: Documenting the African American Experience.

ERIC Educational Resources Information Center

Chepesiuk, Ron

1993-01-01

Describes the Amistad Research Center housed at Tulane University which is a repository of primary documents on African-American history. Topics addressed include the development and growth of the collection; inclusion of the American Missionary Association archives; sources of support; civil rights; and collecting for the future. (LRW)

Using Empirical Mode Decomposition to process Marine Magnetotelluric Data

NASA Astrophysics Data System (ADS)

Chen, J.; Jegen, M. D.; Heincke, B. H.; Moorkamp, M.

2014-12-01

The magnetotelluric (MT) data always exhibits nonstationarities due to variations of source mechanisms causing MT variations on different time and spatial scales. An additional non-stationary component is introduced through noise, which is particularly pronounced in marine MT data through motion induced noise caused by time-varying wave motion and currents. We present a new heuristic method for dealing with the non-stationarity of MT time series based on Empirical Mode Decomposition (EMD). The EMD method is used in combination with the derived instantaneous spectra to determine impedance estimates. The procedure is tested on synthetic and field MT data. In synthetic tests the reliability of impedance estimates from EMD-based method is compared to the synthetic responses of a 1D layered model. To examine how estimates are affected by noise, stochastic stationary and non-stationary noise are added on the time series. Comparisons reveal that estimates by the EMD-based method are generally more stable than those by simple Fourier analysis. Furthermore, the results are compared to those derived by a commonly used Fourier-based MT data processing software (BIRRP), which incorporates additional sophisticated robust estimations to deal with noise issues. It is revealed that the results from both methods are already comparable, even though no robust estimate procedures are implemented in the EMD approach at present stage. The processing scheme is then applied to marine MT field data. Testing is performed on short, relatively quiet segments of several data sets, as well as on long segments of data with many non-stationary noise packages. Compared to BIRRP, the new method gives comparable or better impedance estimates, furthermore, the estimates are extended to lower frequencies and less noise biased estimates with smaller error bars are obtained at high frequencies. The new processing methodology represents an important step towards deriving a better resolved Earth model to

Magnetotelluric Investigation of Melt Storage Beneath Okmok Caldera, Alaska

NASA Astrophysics Data System (ADS)

Bennington, N. L.; Bedrosian, P.; Key, K.; Zelenak, G.

2015-12-01

Alaska accounts for nearly 99% of the seismic moment release within the US. Much of this is associated with the Aleutian volcanic arc, the most tectonically active region in North America, and an ideal location for studying arc magmatism. Okmok is an active volcano located in the central Aleutian arc, defined by a pair of nested, 10 km diameter calderas. The subdued topography of Okmok, relative to other Aleutian volcanoes, improves access and permits dense sampling within the caldera closer to the underlying magmatic system. Okmok volcano was selected as the site of study for this project due to frequent volcanic activity and the presence of a crustal magma reservoir as inferred from previous coarse resolution seismic studies. In June-July 2015, we carried out an amphibious geophysical field deployment at Okmok. Onshore work in and around the volcano included collection of an array of magnetotelluric (MT) stations and installation of a temporary, year-long seismic array. A ring of 3D offshore MT deployments made around the island augments the onshore array. An additional 2D tectonic-scale profile spans the trench, volcanic arc, and backarc. This new geophysical data will be used to gain a greater understanding of Aleutian arc melt generation, migration, and storage beneath an active caldera. We present results from the analysis of the newly collected amphibious 3D MT data. This data will be used to model the distribution and migration of melt within Okmok's crustal magma reservoir. Initial processing of the data shows strong MT signal levels, in particular from a geomagnetic storm that occurred from June 21-23, 2015. A companion abstract discussing the 2D tectonic scale MT profile, which constrains the mantle and deep crust beneath Okmok volcano, is discussed by Zelenak et al.

Magnetotelluric and aeromagnetic investigations for assessment of groundwater resources in Parnaiba basin in Piaui State of North-East Brazil

NASA Astrophysics Data System (ADS)

Chandrasekhar, E.; Fontes, Sergio L.; Flexor, Jean M.; Rajaram, Mita; Anand, S. P.

2009-06-01

In an attempt to locate the presence of possible groundwater resource regions in the semi-arid North-East Brazil, an integrated survey including aeromagnetic and magnetotelluric (MT) studies have been undertaken in the Guaribas region and only MT survey in the Caracol region. In the Guaribas region the aeromagnetic data, its analytic signal and Euler solutions reveal several subsurface small-scale faults and intrusives that are conducive to be potential groundwater resource regions. A total of about 22 broad-band magnetotelluric (MT) soundings in the period range of 0.006-300 s along two profiles on the marginal arcs of the intra-cratonic sedimentary Parnaíba basin in North-East Brazil have been made across the regional geological strike, the Senador Pompeu Lineament (SPL). SPL trends N40°E and marks a basement high reflecting an irregularity in the original basin geometry. While one of the MT profiles traverses across the SPL, the other lies only in the aeromagnetically surveyed sedimentary region. Two-dimensional inversion of MT data of both profiles shows that the sedimentary basin is conductive (100-150 Ω m) and shows as a thin graben with an average thickness of about 2-3 km beneath both profiles. The basin is located to be at shallow depths (from surface to about 500 m). Based on the facts that the study region falls on sedimentary region having low-to-very low permeability and also in accordance with the subsurface lithology around the study region, the mapped sedimentary basin largely manifests the zone of potential sedimentary aquifer having moderate resistivity of 50-250 Ω m and is located at relatively shallow depths. The identified aquifer zone is believed to have links with the Parnaiba River flowing at a distance of about 300 km NW from the study region. We discuss interpretation of our results of MT and aeromagnetic data sets in the light of hydrological features of the study region.

Three-dimensional Magnetotelluric Modeling of the Pohukuloa Training Area, Hawaii Island

NASA Astrophysics Data System (ADS)

Thomas, D. M.; Lienert, B. R.; Wallin, E.

2015-12-01

We report the results of 3D modeling of magnetotelluric (MT) data collected in the Pohakuloa Training Area (PTA) on the saddle between Mauna Loa and Mauna Kea volcanoes on Hawaii Island. We have previously used lower frequency MT data to construct 1D and 2D resistivity profiles in this area and confirmed the presence of a low-resistivity region at depths of about 2 km. One of our drill holes in PTA had previously encountered temperatures of 150 C at a similar depth. However, our 1D and 2D models were unable to fit features of the data that we suspected were due to 3D variations in subsurface resistivity. For the 3D modeling, we reprocessed the higher frequency data (1 kHz sampling rate) which were available at all 20 sites. We were then able to obtain complex impedances at frequencies of 0.5-500 Hz to use for the 3D inversion. We used Siripunvaraporn's 3D inversion method to obtain resistivities in a rectangular array of 0.5x0.5x0.25 km blocks spanning the areal extent of the stations down to a depth of 2.5 km. The results confirmed that much of the anomalous data could be explained by near-surface 3D variations in resistivity. The underlying conductor of 5-10 ohm-m at 2 km depth now appears to extend over the entire survey area.

A hermeneutic phenomenological study of the experiences of female African American undergraduate engineering students at a predominantly White and an historically Black institution

NASA Astrophysics Data System (ADS)

Frillman, Sharron Ann

2011-12-01

This phenomenological study examined the experiences of twelve female African Americans enrolled as fulltime undergraduate engineering students at North Carolina Agricultural and Technical State University, an historically Black university, and seven female African Americans enrolled as undergraduate engineering students at Purdue University in West Lafayette, Indiana, a traditionally White institution. Interviews provided insights into the "lived" experiences of these young women and the factors they believe have contributed to their success in their respective engineering programs. Data analysis involved coding each participant's responses to interview questions using Atlas.ti, a powerful qualitative data analysis tool. This generated 181 codes that were further categorized into nine emergent themes, indicating the potential for extensive associations among the variables. The emergent themes are as follows: (1) Demographic information/special circumstances, (2) Personal attributes and characteristics, (3) Personal insights, (4) Sense of mission, (5) Sources of negative stress, (6) Success strategies, (7) Various forms of support, (8) Would/would not have made it to where she is now, and (9) Being African American and female in engineering. Analysis of these themes and their relationships led to the development of the Frillman Model of Emergent Themes in Female African American Engineering Students. Success. In addressing similarities and differences, three overriding theme categories emerged. These were: (1) Four personhood themes and dual social identity theme; (2) Environmental input and response theme; and (3) Outcome emergent theme of Would/Would not have made it to where she is now. Recommendations were made for future research to expand upon this exploratory study.

Impact of race on the professional lives of physicians of African descent.

PubMed

Nunez-Smith, Marcella; Curry, Leslie A; Bigby, JudyAnn; Berg, David; Krumholz, Harlan M; Bradley, Elizabeth H

2007-01-02

Increasing the racial and ethnic diversity of the physician workforce is a national priority. However, insight into the professional experiences of minority physicians is limited. This knowledge is fundamental to developing effective strategies to recruit, retain, and support a diverse physician workforce. To characterize how physicians of African descent experience race in the workplace. Qualitative study based on in-person and in-depth racially concordant interviews using a standard discussion guide. The 6 New England states in the United States. 25 practicing physicians of African descent representing a diverse range of primary practice settings, specialties, and ages. Professional experiences of physicians of African descent. 1) Awareness of race permeates the experience of physicians of African descent in the health care workplace; 2) race-related experiences shape interpersonal interactions and define the institutional climate; 3) responses to perceived racism at work vary along a spectrum from minimization to confrontation; 4) the health care workplace is often silent on issues of race; and 5) collective race-related experiences can result in "racial fatigue," with personal and professional consequences for physicians. The study was restricted to New England and may not reflect the experiences of physicians in other geographic regions. The findings are meant to be hypothesis-generating and require additional follow-up studies. The issue of race remains a pervasive influence in the work lives of physicians of African descent. Without sufficient attention to the specific ways in which race shapes physicians' work experiences, health care organizations are unlikely to create environments that successfully foster and sustain a diverse physician workforce.

Regularized inversion of controlled source audio-frequency magnetotelluric data in horizontally layered transversely isotropic media

NASA Astrophysics Data System (ADS)

Zhou, Jianmei; Wang, Jianxun; Shang, Qinglong; Wang, Hongnian; Yin, Changchun

2014-04-01

We present an algorithm for inverting controlled source audio-frequency magnetotelluric (CSAMT) data in horizontally layered transversely isotropic (TI) media. The popular inversion method parameterizes the media into a large number of layers which have fixed thickness and only reconstruct the conductivities (e.g. Occam's inversion), which does not enable the recovery of the sharp interfaces between layers. In this paper, we simultaneously reconstruct all the model parameters, including both the horizontal and vertical conductivities and layer depths. Applying the perturbation principle and the dyadic Green's function in TI media, we derive the analytic expression of Fréchet derivatives of CSAMT responses with respect to all the model parameters in the form of Sommerfeld integrals. A regularized iterative inversion method is established to simultaneously reconstruct all the model parameters. Numerical results show that the inverse algorithm, including the depths of the layer interfaces, can significantly improve the inverse results. It can not only reconstruct the sharp interfaces between layers, but also can obtain conductivities close to the true value.

Leading the Way: Inside the Experiences of High-Achieving African-American Male Students

ERIC Educational Resources Information Center

Harper, Shaun R.

2005-01-01

More than two-thirds of all African American males who begin college never finish. This and a legion of other discouraging facts about African American males are the usual headlines. Sharon Fries-Britt suggests that "the disproportionate focus on Black underachievement in the literature not only distorts the image of the community of Black…

African concepts of health, disease, and treatment: an ethical inquiry.

PubMed

Omonzejele, Peter F

2008-01-01

This paper is based on the author's fieldwork experience in Edo State, Nigeria. The purpose of the article is to present and discuss African concepts of health, disease, and treatment within the framework of African Traditional Medicine (ATM). The two-fold notion of disease and treatment within the African context is also addressed. The significance of rituals and sacrifices in ATM are explained, and the interactions between ATM, African metaphysics, and cosmology are highlighted. The rules and moral precepts tenable in the practice of ATM are analyzed and discussed. The methodology employed in this study was the interviewing of African traditional healers.

Meaning of bereavement among older African American widows.

PubMed

Rodgers, Laura S

2004-01-01

In spite of the increase in research on spousal bereavement, researchers have not specifically addressed the impact that ethnicity may have on the bereavement experience. The results of this descriptive phenomenological study increase the understanding of spousal bereavement among older African American widows. Storytelling was at the heart of every participant's description of her bereavement experience. Six themes were identified: awareness of death, care giving, getting through, moving on, changing feelings, and financial security. For nurses to effectively intervene in the lives of bereaved older African American widows, they must consider each widow's culture, heritage, and lived experiences, which can be ascertained through eliciting and listening to the widow's life stories.

Hematopoietic SCT for the Black African and non-Black African variants of sickle cell anemia.

PubMed

Lucarelli, G; Isgrò, A; Sodani, P; Marziali, M; Gaziev, J; Paciaroni, K; Gallucci, C; Cardarelli, L; Ribersani, M; Alfieri, C; De Angelis, G; Armiento, D; Andreani, M; Testi, M; Amato, A; Akinyanju, O O; Wakama, T T

2014-11-01

Sickle cell anemia (SCA) remains associated with high risks of morbidity and early death. Allogeneic hematopoietic SCT (HSCT) is the only curative treatment for SCA. We report our experience with transplantation in a group of patients with the non-Black African variant and the Black African variant of SCA. This study included 40 consecutive SCA patients (13 patients with the non-Black African variant and 27 with the Black African variant) who underwent BM transplantation from HLA-identical sibling donors between June 2004 and May 2013, following a myeloablative-conditioning regimen. All patients obtained sustained engraftment. One patient (non-Black African variant) became a stable mixed chimera with 25% donor cells more than 6 years after transplantation. The probabilities of survival, SCA-free survival and TRM at 5 years after transplant were 91%, 91% and 9%, respectively. All surviving patients remained free of any SCA-related events after transplantation. Our results confirm that it is possible to offer a greater than 90% chance of cure to children with SCA. HSCT should be considered the standard of care for who have an HLA-identical donor, before complications result from the sickling of RBC.

Men of the Cloth: African-American Clergy's Knowledge and Experience in Providing Pastoral Care to African-American Elders with Late-Life Depression

ERIC Educational Resources Information Center

Stansbury, Kim L.

2011-01-01

African-American clergy's ability to recognize late-life depression and their capacity to provide support with this illness have been neglected in the literature. Using a mental health literacy framework, the purpose of this research was to explore African-American clergy's knowledge of and treatments for late-life depression. In-depth interviews…

Resistivity imaging of Aluto-Langano geothermal field using 3-D magnetotelluric inversion

NASA Astrophysics Data System (ADS)

Cherkose, Biruk Abera; Mizunaga, Hideki

2018-03-01

Magnetotelluric (MT) method is a widely used geophysical method in geothermal exploration. It is used to image subsurface resistivity structures from shallow depths up to several kilometers of depth. Resistivity imaging using MT method in high-enthalpy geothermal systems is an effective tool to identify conductive clay layers that cover the geothermal systems and to detect a potential reservoir. A resistivity model is vital for deciding the location of pilot and production sites at the early stages of a geothermal project. In this study, a 3-D resistivity model of Aluto-Langano geothermal field was constructed to map structures related to a geothermal resource. The inversion program, ModEM was used to recover the 3-D resistivity model of the study area. The 3-D inversion result revealed the three main resistivity structures: a high-resistivity surface layer related to unaltered volcanic rocks at shallow depth, underlain by a conductive zone associated with the presence of conductive clay minerals, predominantly smectite. Beneath the conductive layer, the resistivity increases gradually to higher values related to the formation of high-temperature alteration minerals such as chlorite and epidote. The resistivity model recovered from 3-D inversion in Aluto-Langano corresponds very well to the conceptual model for high-enthalpy volcanic geothermal systems. The conductive clay cap is overlying the resistive propylitic upflow zone as confirmed by the geothermal wells in the area.

Cultural Barriers to African American Participation in Anxiety Disorders Research

PubMed Central

Williams, Monnica T.; Beckmann-Mendez, Diana A.; Turkheimer, Eric

2014-01-01

Anxiety disorders are understudied, underdiagnosed, and undertreated in African Americans. Research focused on the phenomenology, etiology, and treatment of anxiety in African Americans has been hampered by lack of inclusion of this population in clinical research studies. The reason for exclusion is not well understood, although cultural mistrust has been hypothesized as a major barrier to research participation. This article reviews the relevant literature to date and examines the experience of 6 African American adults who participated in a larger clinical assessment study about anxiety. Drawing upon in-depth semistructured interviews about their subjective experiences, we examined participant perspectives about the assessment process, opinions about African American perception of anxiety studies, and participant-generated ideas about how to improve African American participation. Based on a qualitative analysis of responses, feelings of mistrust emerged as a dominant theme. Concerns fell under 6 categories, including not wanting to speak for others, confidentiality, self and group presentation concerns, repercussions of disclosure, potential covert purposes of the study, and the desire to confide only in close others. Suggestions for increasing African American participation are discussed, including assurances of confidentiality, adequate compensation, and a comfortable study environment. PMID:23862294

Distribution of melt beneath Mount St Helens and Mount Adams inferred from magnetotelluric data

NASA Astrophysics Data System (ADS)

Hill, Graham J.; Caldwell, T. Grant; Heise, Wiebke; Chertkoff, Darren G.; Bibby, Hugh M.; Burgess, Matt K.; Cull, James P.; Cas, Ray A. F.

2009-11-01

Three prominent volcanoes that form part of the Cascade mountain range in Washington State (USA)-Mounts St Helens, Adams and Rainier-are located on the margins of a mid-crustal zone of high electrical conductivity. Interconnected melt can increase the bulk conductivity of the region containing the melt, which leads us to propose that the anomalous conductivity in this region is due to partial melt associated with the volcanism. Here we test this hypothesis by using magnetotelluric data recorded at a network of 85 locations in the area of the high-conductivity anomaly. Our data reveal that a localized zone of high conductivity beneath this volcano extends downwards to join the mid-crustal conductor. As our measurements were made during the recent period of lava extrusion at Mount St Helens, we infer that the conductivity anomaly associated with the localized zone, and by extension with the mid-crustal conductor, is caused by the presence of partial melt. Our interpretation is consistent with the crustal origin of silicic magmas erupting from Mount St Helens, and explains the distribution of seismicity observed at the time of the catastrophic eruption in 1980 (refs 9, 10).

Aspects of the Student Engagement of African American Men in Community College

ERIC Educational Resources Information Center

Romney, Paulette B.

2012-01-01

High attrition rates of African American college students' is a continuing concern of higher education administrators. This is particularly true of African American men attending community college. African American men consistently experience low levels of scholastic achievement as a result of entering college underprepared, with academic deficits…

4D inversion of time-lapse magnetotelluric data sets for monitoring geothermal reservoir

NASA Astrophysics Data System (ADS)

Nam, Myung Jin; Song, Yoonho; Jang, Hannuree; Kim, Bitnarae

2017-06-01

The productivity of a geothermal reservoir, which is a function of the pore-space and fluid-flow path of the reservoir, varies since the properties of the reservoir changes with geothermal reservoir production. Because the variation in the reservoir properties causes changes in electrical resistivity, time-lapse (TL) three-dimensional (3D) magnetotelluric (MT) methods can be applied to monitor the productivity variation of a geothermal reservoir thanks to not only its sensitivity to the electrical resistivity but also its deep depth of survey penetration. For an accurate interpretation of TL MT-data sets, a four-dimensional (4D) MT inversion algorithm has been developed to simultaneously invert all vintage data considering time-coupling between vintages. However, the changes in electrical resistivity of deep geothermal reservoirs are usually small generating minimum variation in TL MT responses. Maximizing the sensitivity of inversion to the changes in resistivity is critical in the success of 4D MT inversion. Thus, we further developed a focused 4D MT inversion method by considering not only the location of a reservoir but also the distribution of newly-generated fractures during the production. For the evaluation of the 4D MT algorithm, we tested our 4D inversion algorithms using synthetic TL MT-data sets.

African American families' expectations and intentions for mental health services.

PubMed

Thompson, Richard; Dancy, Barbara L; Wiley, Tisha R A; Najdowski, Cynthia J; Perry, Sylvia P; Wallis, Jason; Mekawi, Yara; Knafl, Kathleen A

2013-09-01

A cross-sectional qualitative descriptive design was used to examine the links among expectations about, experiences with, and intentions toward mental health services. Individual face-to-face interviews were conducted with a purposive sample of 32 African American youth/mothers dyads. Content analysis revealed that positive expectations were linked to positive experiences and intentions, that negative expectations were not consistently linked to negative experiences or intentions, nor were ambivalent expectations linked to ambivalent experiences or intentions. Youth were concerned about privacy breeches and mothers about the harmfulness of psychotropic medication. Addressing these concerns may promote African Americans' engagement in mental health services.

Esophageal Carcinoma in African Americans: A Five-Decade Experience

PubMed Central

Nouri, Zahra; Nouraie, Mehdi; Razjouyan, Hadi; Lee, Edward E.; Dowlati, Ehsan; El-Seyed, El-Waleed; Laiyemo, Adeyinka; Brim, Hassan; Smoot, Duane T.

2012-01-01

Background Esophageal cancer accounts for a considerable proportion of carcinomas of the upper gastrointestinal tract in African Americans. Our aim was to describe the epidemiology of esophageal squamous cell cancer (ESCC) and esophageal adenocarcinoma (EA) among African Americans in the last five decades. Methods A total of 601 records of patients with documented esophageal cancer between 1959 and 2007 at Howard University Hospital were reviewed. Demographic characteristics, risk factors, clinical stage and histological findings were reviewed. The change in prevalence of the disease and the interaction between main risk factors with tumor stage of the patients were assessed over the years of this study. Result A total of 552 patients (91.8%) had ESCC while 49 patients (8.2%) had EA. The mean age at diagnosis was 60.1 and 60.6 years for ESCC and EA, respectively (P = 0.8). The peak incidence was in the 1980–1989 decade. Out of 136 ESCC patients with TNM staging information, 130 (95.6%) were diagnosed in stage 2 and above. The majority (73%) of the ESCC were in the mid- and upper third of the esophagus and associated with smoking and alcohol exposure. The majority (81%) of the EA were in the mid- and lower third. The most common presenting symptoms were dysphagia (77.7%), and weight loss (31.9%). Conclusion ESCC is the predominant esophageal cancer in African Americans and diagnosed in late stages, and its diagnosis in our institution has decreased since 1990. A combination of genetic factors, environmental influences (e.g., those related to diet), and the deleterious changes associated with smoking and alcohol consumption, and differences in tumor histology, are the obvious parameters that should be the focus of future studies, and early diagnosis at an earlier stage should be considered among blacks. PMID:21847566

The Impact of African American Parents' Racial Discrimination Experiences and Perceived Neighborhood Cohesion on their Racial Socialization Practices.

PubMed

Saleem, Farzana T; English, Devin; Busby, Danielle R; Lambert, Sharon F; Harrison, Aubrey; Stock, Michelle L; Gibbons, Frederick X

2016-07-01

Parental racial socialization is a parenting tool used to prepare African American adolescents for managing racial stressors. While it is known that parents' racial discrimination experiences affect the racial socialization messages they provide, little is known about the influence of factors that promote supportive and communal parenting, such as perceived neighborhood cohesion. In cohesive neighborhoods, neighbors may help parents address racial discrimination by monitoring youth and conveying racial socialization messages; additionally, the effect of neighborhood cohesion on parents' racial socialization may differ for boys and girls because parents socialize adolescents about race differently based on expected encounters with racial discrimination. Therefore, the current study examines how parents' perception of neighborhood cohesion and adolescents' gender moderate associations between parents' racial discrimination experiences and the racial socialization messages they deliver to their adolescents. Participants were a community sample of 608 African American adolescents (54 % girls; mean age = 15.5) and their primary caregivers (86 % biological mothers; mean age = 42.0). Structural equation modeling indicated that parental racial discrimination was associated with more promotion of mistrust messages for boys and girls in communities with low neighborhood cohesion. In addition, parental racial discrimination was associated with more cultural socialization messages about racial pride and history for boys in neighborhoods with low neighborhood cohesion. The findings suggest that parents' racial socialization messages are influenced by their own racial discrimination experiences and the cohesiveness of the neighborhood; furthermore, the content of parental messages delivered varies based on adolescents' gender.

Family matters: Familial support and science identity formation for African American female STEM majors

NASA Astrophysics Data System (ADS)

Parker, Ashley Dawn

This research seeks to understand the experiences of African American female undergraduates in STEM. It investigates how familial factors and science identity formation characteristics influence persistence in STEM while considering the duality of African American women's status in society. This phenomenological study was designed using critical race feminism as the theoretical framework to answer the following questions: 1) What role does family play in the experiences of African American women undergraduate STEM majors who attended two universities in the UNC system? 2) What factors impact the formation of science identity for African American women undergraduate STEM majors who attended two universities in the UNC system? Purposive sampling was used to select the participants for this study. The researcher conducted in-depth interviews with 10 African American female undergraduate STEM major from a predominantly White and a historically Black institution with the state of North Carolina public university system. Findings suggest that African American families and science identity formation influence the STEM experiences of the African American females interviewed in this study. The following five themes emerged from the findings: (1) independence, (2) support, (3) pressure to succeed, (4) adaptations, and (5) race and gender. This study contributes to the literature on African American female students in STEM higher education. The findings of this study produced knowledge regarding policies and practices that can lead to greater academic success and persistence of African American females in higher education in general, and STEM majors in particular. Colleges and universities may benefit from the findings of this study in a way that allows them to develop and sustain programs and policies that attend to the particular concerns and needs of African American women on their campuses. Finally, this research informs both current and future African American female

Shared conceptualizations and divergent experiences of counseling among African American and white older adults.

PubMed

Joo, Jin Hui; Wittink, Marsha; Dahlberg, Britt

2011-08-01

Research findings suggest that older adults prefer counseling for depression treatment; however, few older adults use counseling services. In this article we present the results of our analysis of semistructured interviews with 102 older adults to explore conceptualizations of counseling and impediments to use among African American and White older adults. We found that older adults believe counseling is beneficial; however, use was hindered in multiple ways. Older adults were skeptical about establishing a caring relationship with a professional. African American older adults did not mention social relationships to facilitate depression care, whereas White older adults described using personal relationships to navigate counseling services. African American older men were least familiar with counseling. Our findings suggest that African American and White older adults share a strong cultural model of counseling as beneficial; however, significant impediments exist and affect older adults differentially based on ethnicity.

African American Female Faculty in Predominantly White Graduate Schools of Social Work

ERIC Educational Resources Information Center

Edwards, Janice Berry; Clark, Trenette T.; Bryant, Shirley

2012-01-01

This study of African American female faculty in predominantly White schools of social work was designed to examine the unique experience of these faculties. The examination also aimed to develop a better understanding of the challenges and the experiences of these faculty members. This exploratory study sampled African American female social work…

Three-dimensional audio-magnetotelluric sounding in monitoring coalbed methane reservoirs

NASA Astrophysics Data System (ADS)

Wang, Nan; Zhao, Shanshan; Hui, Jian; Qin, Qiming

2017-03-01

Audio-magnetotelluric (AMT) sounding is widely employed in rapid resistivity delineation of objective geometry in near surface exploration. According to reservoir patterns and electrical parameters obtained in Qinshui Basin, China, two-dimensional and three-dimensional synthetic "objective anomaly" models were designed and inverted with the availability of a modular system for electromagnetic inversion (ModEM). The results revealed that 3-D full impedance inversion yielded the subsurface models closest to synthetic models. One or more conductive targets were correctly recovered. Therefore, conductive aquifers in the study area, including hydrous coalbed methane (CBM) reservoirs, were suggested to be the interpretation signs for reservoir characterization. With the aim of dynamic monitoring of CBM reservoirs, the AMT surveys in continuous years (June 2013-May 2015) were carried out. 3-D inversion results demonstrated that conductive anomalies accumulated around the producing reservoirs at the corresponding depths if CBM reservoirs were in high water production rates. In contrast, smaller conductive anomalies were generally identical with rapid gas production or stopping production of reservoirs. These analyses were in accordance with actual production history of CBM wells. The dynamic traces of conductive anomalies revealed that reservoir water migrated deep or converged in axial parts and wings of folds, which contributed significantly to formations of CBM traps. Then the well spacing scenario was also evaluated based on the dynamic production analysis. Wells distributed near closed faults or flat folds, rather than open faults, had CBM production potential to ascertain stable gas production. Therefore, three-dimensional AMT sounding becomes an attractive option with the ability of dynamic monitoring of CBM reservoirs, and lays a solid foundation of quantitative evaluation of reservoir parameters.

Racism at the intersections: Gender and socioeconomic differences in the experience of racism among African Americans.

PubMed

Kwate, Naa Oyo A; Goodman, Melody S

2015-09-01

Several studies investigating the health effects of racism have reported gender and socioeconomic differences in exposures to racism, with women typically reporting lower frequencies, and individuals with greater resources reporting higher frequencies. This study used diverse measures of socioeconomic position and multiple measures and methods to assess experienced racism. Socioeconomic position included education and financial and employment status. Quantitative racism measures assessed individual experiences with day-to-day and with major lifetime incidents and perceptions of the extent to which African Americans as a group experience racism. A brief qualitative question asked respondents to describe a racist incident that stood out in recent memory. Participants comprised a probability sample of N = 144 African American adults aged 19 to 87 residing in New York City. Results suggested that women reported fewer lifetime incidents but did not differ from men on everyday racism. These differences appear to be partly because of scale content. Socioeconomic position as measured by years of education was positively associated with reported racism in the total sample but differently patterned across gender; subjective social status showed a negative association. Qualitative responses describing memorable incidents fell into 5 key categories: resources/opportunity structures, criminal profiling, racial aggression/assault, interpersonal incivilities, and stereotyping. In these narratives, men were more likely to offer accounts involving criminal profiling, and women encountered incivilities more often. The findings highlight the need for closer attention to the intersection of gender and socioeconomic factors in investigations of the health effects of racism. (c) 2015 APA, all rights reserved).

Health system strengthening: a qualitative evaluation of implementation experience and lessons learned across five African countries.

PubMed

Rwabukwisi, Felix Cyamatare; Bawah, Ayaga A; Gimbel, Sarah; Phillips, James F; Mutale, Wilbroad; Drobac, Peter

2017-12-21

Achieving the United Nations Sustainable Development Goals in sub-Saharan Africa will require substantial improvements in the coverage and performance of primary health care delivery systems. Projects supported by the Doris Duke Charitable Foundation's (DDCF) African Health Initiative (AHI) created public-private-academic and community partnerships in five African countries to implement and evaluate district-level health system strengthening interventions. In this study, we captured common implementation experiences and lessons learned to understand core elements of successful health systems interventions. We used qualitative data from key informant interviews and annual progress reports from the five Population Health Implementation and Training (PHIT) partnership projects funded through AHI in Ghana, Mozambique, Rwanda, Tanzania, and Zambia. Four major overarching lessons were highlighted. First, variety and inclusiveness of concerned key players (public, academic and private) are necessary to address complex health system issues at all levels. Second, a learning culture that promotes evidence creation and ability to efficiently adapt were key in order to meet changing contextual needs. Third, inclusion of strong implementation science tools and strategies allowed informed and measured learning processes and efficient dissemination of best practices. Fourth, five to seven years was the minimum time frame necessary to effectively implement complex health system strengthening interventions and generate the evidence base needed to advocate for sustainable change for the PHIT partnership projects. The AHI experience has raised remaining, if not overlooked, challenges and potential solutions to address complex health systems strengthening intervention designs and implementation issues, while aiming to measurably accomplish sustainable positive change in dynamic, learning, and varied contexts.

Lessons Learned: Research within an Urban, African American District

ERIC Educational Resources Information Center

Scott, Kimberly Ann

2012-01-01

For an African American female researcher whose race, class, and gender work as oppressive intersecting units shaping my contextualized experiences, meaning-making, and self-definition, the implications of my work with African American communities are complicated. In this article, I draw on culturally sensitive research practices, critical race…

IRETHERM: Magnetotelluric studies of Irish radiothermal granites and their geothermal energy potential

NASA Astrophysics Data System (ADS)

Farrell, T. F.; Jones, A. G.; Muller, M. R.; Feely, M.

2013-12-01

The IRETHERM project seeks to develop a strategic understanding of Ireland's deep geothermal energy potential through integrated modeling of new and existing geophysical and geological data. One aspect of IRETHERM's research focuses on Ireland's radiothermal granites, where increased concentrations of radioelements provide elevated heat-production (HP), heat-flow (HF) and subsurface temperatures. An understanding of the contribution of granites to the thermal field of Ireland is of key importance in assessing the geothermal energy potential of this low-enthalpy setting. This study focuses on the Leinster granite, the Galway granite and the buried Kentstown granite. Shallow (<250 m) boreholes were drilled into the exposed Caledonian Leinster and Galway granites as part of an early 1980's EU-funded geothermal project. These studies yielded HP = 2-3 μWm-3 and HF = 80 mWm-2 at the Sally Gap borehole in the Northern Units of the Leinster granite. In the Galway granite batholith, the Costelloe-Murvey granite returned HP = 7 μWm-3 and HF = 77 mWm-2, measured at the Ros a Mhil borehole. The lower heat-flow encountered at the Ros a Mhil borehole suggests that the associated high heat production does not extend to great depth. The buried Kentstown granite has associated with it a significant negative Bouguer anomaly and was intersected by two mineral exploration boreholes at depths of 660 m and 485 m. Heat production has been measured at 2.4 μWm-3 in core samples taken from the weathered top 30m of the granite. The core of this study consists of an ambitious program of magnetotelluric (MT) and audio-magnetotelluric (AMT) data acquisition across the three granite bodies, extending over three fieldwork seasons. MT and AMT data were collected at 59 locations along two profiles over the Leinster granite. Preliminary results show that the northern units of the Leinster granite extend to depths of 2-5 km. Over the Galway granite, MT and AMT data have been collected at a total

Factors Associated with Partnership Experiences, Attitudes, and Perceptions: A Comparative Case Study of Two African Universities

ERIC Educational Resources Information Center

Chiteng Kot, Felly

2011-01-01

International partnerships have become an increasingly important trend in African higher education. The creation of partnerships with African universities has been on the rise in the last few years. Different factors (U.S., European, and African initiatives) suggest this trend will continue to increase. This study draws from a survey of a random…

Black versus Black: The Relationship among African, African American, and African Caribbean Persons.

ERIC Educational Resources Information Center

Jackson, Jennifer V.; Cothran, Mary E.

2003-01-01

Surveyed people of African descent regarding relationships among African, African-American, and African-Caribbean persons, focusing on contact and friendship, travel to countries of the diaspora, cross-cultural communication, thoughts and stereotypes, and education. Most respondents had contacts with the other groups, but groups had preconceived…

3D inversion based on multi-grid approach of magnetotelluric data from Northern Scandinavia

NASA Astrophysics Data System (ADS)

Cherevatova, M.; Smirnov, M.; Korja, T. J.; Egbert, G. D.

2012-12-01

In this work we investigate the geoelectrical structure of the cratonic margin of Fennoscandian Shield by means of magnetotelluric (MT) measurements carried out in Northern Norway and Sweden during summer 2011-2012. The project Magnetotellurics in the Scandes (MaSca) focuses on the investigation of the crust, upper mantle and lithospheric structure in a transition zone from a stable Precambrian cratonic interior to a passive continental margin beneath the Caledonian Orogen and the Scandes Mountains in western Fennoscandia. Recent MT profiles in the central and southern Scandes indicated a large contrast in resistivity between Caledonides and Precambrian basement. The alum shales as a highly conductive layers between the resistive Precambrian basement and the overlying Caledonian nappes are revealed from this profiles. Additional measurements in the Northern Scandes were required. All together data from 60 synchronous long period (LMT) and about 200 broad band (BMT) sites were acquired. The array stretches from Lofoten and Bodo (Norway) in the west to Kiruna and Skeleftea (Sweden) in the east covering an area of 500x500 square kilometers. LMT sites were occupied for about two months, while most of the BMT sites were measured during one day. We have used new multi-grid approach for 3D electromagnetic (EM) inversion and modelling. Our approach is based on the OcTree discretization where the spatial domain is represented by rectangular cells, each of which might be subdivided (recursively) into eight sub-cells. In this simplified implementation the grid is refined only in the horizontal direction, uniformly in each vertical layer. Using multi-grid we manage to have a high grid resolution near the surface (for instance, to tackle with galvanic distortions) and lower resolution at greater depth as the EM fields decay in the Earth according to the diffusion equation. We also have a benefit in computational costs as number of unknowns decrease. The multi-grid forward

Using EarthScope magnetotelluric data to improve the resilience of the US power grid: rapid predictions of geomagnetically induced currents

NASA Astrophysics Data System (ADS)

Schultz, A.; Bonner, L. R., IV

2016-12-01

Existing methods to predict Geomagnetically Induced Currents (GICs) in power grids, such as the North American Electric Reliability Corporation standard adopted by the power industry, require explicit knowledge of the electrical resistivity structure of the crust and mantle to solve for ground level electric fields along transmission lines. The current standard is to apply regional 1-D resistivity models to this problem, which facilitates rapid solution of the governing equations. The systematic mapping of continental resistivity structure from projects such as EarthScope reveals several orders of magnitude of lateral variations in resistivity on local, regional and continental scales, resulting in electric field intensifications relative to existing 1-D solutions that can impact GICs to first order. The computational burden on the ground resistivity/GIC problem of coupled 3-D solutions inhibits the prediction of GICs in a timeframe useful to protecting power grids. In this work we reduce the problem to applying a set of filters, recognizing that the magnetotelluric impedance tensors implicitly contain all known information about the resistivity structure beneath a given site, and thus provides the required relationship between electric and magnetic fields at each site. We project real-time magnetic field data from distant magnetic observatories through a robustly calculated multivariate transfer function to locations where magnetotelluric impedance tensors had previously been obtained. This provides a real-time prediction of the magnetic field at each of those points. We then project the predicted magnetic fields through the impedance tensors to obtain predictions of electric fields induced at ground level. Thus, electric field predictions can be generated in real-time for an entire array from real-time observatory data, then interpolated onto points representing a power transmission line contained within the array to produce a combined electric field prediction

Safe Havens for African American Students: Finding Support on a White Campus. Draft.

ERIC Educational Resources Information Center

Davis, R. Deborah

This study examined comments from a qualitative study regarding African American students' level of adjustment at predominantly white institutions. A phenomenological approach and ethno-methodology provided the framework to focus on what African American students experience and how they interpret their experiences in what they perceive as a…

Inversion of magnetotelluric data using integral equation approach with variable sensitivity domain: Application to EarthScope MT data

NASA Astrophysics Data System (ADS)

Čuma, Martin; Gribenko, Alexander; Zhdanov, Michael S.

2017-09-01

We have developed a multi-level parallel magnetotelluric (MT) integral equation based inversion program which uses variable sensitivity domain. The limited sensitivity of the data, which decreases with increasing frequency, is exploited by a receiver sensitivity domain, which also varies with frequency. We assess the effect of inverting principal impedances, full impedance tensor, and full tensor jointly with magnetovariational data (tipper). We first apply this method to several models and then invert the EarthScope MT data. We recover well the prominent features in the area including resistive structure associated with the Juan de Fuca slab subducting beneath the northwestern United States, the conductive zone of partially melted material above the subducting slab at the Cascade volcanic arc, conductive features in the Great Basin and in the area of Yellowstone associated with the hot spot, and resistive areas to the east corresponding to the older and more stable cratons.

Teachers' Perception of African American Middle School Girls' Interest in Mathematics and Science

NASA Astrophysics Data System (ADS)

Best, Bonnie M.

Research into African American female underrepresentation in science, technology, engineering, and mathematics (STEM) fields has become an area of interest due to the fact that a majority of African American middle school females do not possess the high levels of mathematics and science knowledge because of social and cultural barriers both inside and outside school that challenge their academic success. The purpose of this qualitative interpretative phenomenological study was to explore teachers' shared, lived experiences of teaching mathematics and science to African American middle school girls. Delgado and Stefancic's critical race theory, Pratt-Clarke's critical race feminism, and Baker-Miller's relational-cultural theory were used to guide this study. Research questions focused on the perceptions and experiences of teachers' lived experiences teaching mathematics and science to African American middle school females. Criterion, purposive, and maximum variation sampling techniques were used to recruit 10 teachers who have 3 or more years' experience teaching African American middle school girls. Semistructured face-to-face interviews were the primary data collection source. First cycle and second cycle coding methods were used to support the analysis of this study. Findings suggest that there is a connection between a positive student-teacher relationship and academic success. The results of this study contribute to positive social change by providing empirical evidence policymakers and teachers can use to improve the mathematics and science instruction and practices that are needed to meet the needs of African American middle school females and reduce the underrepresentation and underachievement of African American females in mathematics and science.

Cradle to third life: An autobiography of an African-American science educator

NASA Astrophysics Data System (ADS)

Caruthers-Jackson, Sarah

This inquiry used reflective autobiographical research to reveal my beliefs, values, and practices of science teaching by using participatory action research with two students of my science tutoring organization. Also, I conducted an ethnographic inquiry using African-American teachers to understand how my early schooling experiences influenced my beliefs, values, and science practices. I collected data for this inquiry from three African-American teachers through interview-conversation that were videotaped and audiotaped. In addition, I audiotaped two African-American students' tutoring practices along with students' and researcher's journals. The findings indicate that African-American teachers during the school years 1942-1954 used families, churches, and communities to secure teaching resources to provide equal education for their African-American students who received limited resources from the board of education. Also indicated was how African-American teachers instilled in their African-American students a level of motivation that remained with some African-American students for their future endeavors. This researcher's beliefs/values similar to those of her segregated teachers emerged from this action research. Researcher's additional beliefs/values arose out of emerging technologies in teaching science. However, I, as the researcher, believe that the origin of my beliefs/values occurred during those segregated, public school experiences at Monitor Schools during the school years 1942-1954.

African American Families’ Expectations and Intentions for Mental Health Services

PubMed Central

Thompson, Richard; Dancy, Barbara L.; Wiley, Tisha R.A.; Najdowski, Cynthia J.; Perry, Sylvia P.; Wallis, Jason; Mekawi, Yara; Knafl, Kathleen

2012-01-01

A cross-sectional qualitative descriptive design was used to examine the links among expectations about, experiences with, and intentions toward mental health services. Individual face-to-face interviews were conducted with a purposive sample of 32 African American youth/mothers dyads. Content analysis revealed that positive expectations were linked to positive experiences and intentions, that negative expectations were not consistently linked to negative experiences or intentions, nor were ambivalent expectations linked to ambivalent experiences or intentions. Youth were concerned about privacy breeches and mothers about the harmfulness of psychotropic medication. Addressing these concerns may promote African Americans’ engagement in mental health services. PMID:22791083

Experiences and Perspectives of African-American, Latina/o, Asian-American and European-American Psychology Graduate Students: A National Study

PubMed Central

Maton, Kenneth I.; Wimms, Harriette E.; Grant, Sheila K.; Wittig, Michele A.; Rogers, Margaret R.; Vasquez, Melba J. T.

2013-01-01

A national, web-based survey of 1,222 African-American, Latina/o, Asian-American and European-American psychology graduate students revealed both similarities and differences in experiences and perspectives. Mentoring was found to be the strongest predictor of satisfaction across groups. Academic supports and barriers, along with perceptions of diversity were also important predictors of satisfaction. Students of color differed from European-American students in perceptions of fairness of representation of their ethnic group within psychology, and in aspects of the graduate school experience perceived as linked to ethnicity. Limitations of the study and implications for future research and action are discussed. PMID:21341899

Experiences and perspectives of African American, Latina/o, Asian American, and European American psychology graduate students: A national study.

PubMed

Maton, Kenneth I; Wimms, Harriette E; Grant, Sheila K; Wittig, Michele A; Rogers, Margaret R; Vasquez, Melba J T

2011-01-01

A national, Web-based survey of 1,219 African American, Latina/o, Asian American, and European American psychology graduate students revealed both similarities and differences in experiences and perspectives. Mentoring was found to be the strongest predictor of satisfaction across groups. Academic supports and barriers, along with perceptions of diversity within the academic environment, were also important predictors of satisfaction. Students of color perceived less fairness of representation of their ethnic group within psychology than European American students, and a greater linkage between aspects of the graduate school experience and their ethnicity. Limitations of the study and implications for future research and action are discussed.

Regularized magnetotelluric inversion based on a minimum support gradient stabilizing functional

NASA Astrophysics Data System (ADS)

Xiang, Yang; Yu, Peng; Zhang, Luolei; Feng, Shaokong; Utada, Hisashi

2017-11-01

Regularization is used to solve the ill-posed problem of magnetotelluric inversion usually by adding a stabilizing functional to the objective functional that allows us to obtain a stable solution. Among a number of possible stabilizing functionals, smoothing constraints are most commonly used, which produce spatially smooth inversion results. However, in some cases, the focused imaging of a sharp electrical boundary is necessary. Although past works have proposed functionals that may be suitable for the imaging of a sharp boundary, such as minimum support and minimum gradient support (MGS) functionals, they involve some difficulties and limitations in practice. In this paper, we propose a minimum support gradient (MSG) stabilizing functional as another possible choice of focusing stabilizer. In this approach, we calculate the gradient of the model stabilizing functional of the minimum support, which affects both the stability and the sharp boundary focus of the inversion. We then apply the discrete weighted matrix form of each stabilizing functional to build a unified form of the objective functional, allowing us to perform a regularized inversion with variety of stabilizing functionals in the same framework. By comparing the one-dimensional and two-dimensional synthetic inversion results obtained using the MSG stabilizing functional and those obtained using other stabilizing functionals, we demonstrate that the MSG results are not only capable of clearly imaging a sharp geoelectrical interface but also quite stable and robust. Overall good performance in terms of both data fitting and model recovery suggests that this stabilizing functional is effective and useful in practical applications.[Figure not available: see fulltext.

Magnetotelluric investigation of the Vestfold Hills and Rauer Group, East Antarctica

USGS Publications Warehouse

Peacock, Jared R.; Selway, Katherine

2016-01-01

The Vestfold Hills and Rauer Group in East Antarctica have contrasting Archean to Neoproterozoic geological histories and are believed to be juxtaposed along a suture zone that now lies beneath the Sørsdal Glacier. Exact location and age of this suture zone are unknown, as is its relationship to regional deformation associated with the amalgamation of East Gondwana. To image the suture zone, magnetotelluric (MT) data were collected in Prydz Bay, East Antarctica, mainly along a profile crossing the Sørsdal Glacier and regions inland of the Vestfold Hills and Rauer Group islands. Time-frequency analysis of the MT time series yielded three important observations: (1) Wind speeds in excess of ∼8 m/s reduce coherence between electric and magnetic fields due to charged wind-blown particles of ice and snow. (2) Estimation of the MT transfer function is best between 1000 and 1400 UT when ionospheric Hall currents enhance the magnetic source field. (3) Nonplanar source field effects were minimal but detectable and removed from estimation of the MT transfer function. Inversions of MT data in 2-D and 3-D produce similar resistivity models, where structures in the preferred 3-D resistivity model correlate strongly with regional magnetic data. The electrically conductive Rauer Group is separated from the less conductive Vestfold Hills by a resistive zone under the Sørsdal Glacier, which is interpreted to be caused by oxidation during suturing. Though a suture zone has been imaged, no time constrains on suturing can be made from the MT data.

Sharp Boundary Inversion of 2D Magnetotelluric Data using Bayesian Method.

NASA Astrophysics Data System (ADS)

Zhou, S.; Huang, Q.

2017-12-01

Normally magnetotelluric(MT) inversion method cannot show the distribution of underground resistivity with clear boundary, even if there are obviously different blocks. Aiming to solve this problem, we develop a Bayesian structure to inverse 2D MT sharp boundary data, using boundary location and inside resistivity as the random variables. Firstly, we use other MT inversion results, like ModEM, to analyze the resistivity distribution roughly. Then, we select the suitable random variables and change its data format to traditional staggered grid parameters, which can be used to do finite difference forward part. Finally, we can shape the posterior probability density(PPD), which contains all the prior information and model-data correlation, by Markov Chain Monte Carlo(MCMC) sampling from prior distribution. The depth, resistivity and their uncertainty can be valued. It also works for sensibility estimation. We applied the method to a synthetic case, which composes two large abnormal blocks in a trivial background. We consider the boundary smooth and the near true model weight constrains that mimic joint inversion or constrained inversion, then we find that the model results a more precise and focused depth distribution. And we also test the inversion without constrains and find that the boundary could also be figured, though not as well. Both inversions have a good valuation of resistivity. The constrained result has a lower root mean square than ModEM inversion result. The data sensibility obtained via PPD shows that the resistivity is the most sensible, center depth comes second and both sides are the worst.

Three-dimensional Magnetotelluric Characterization of the Xinzhou Geothermal Field, Southeastern China

NASA Astrophysics Data System (ADS)

Han, Q.; Hu, X.; Cai, J.; Wei, W.

2016-12-01

Xinzhou geothermal field is located in the Guangdong province and adjacent to the China South Sea, and its hot springs can reach up to 92 degree Celsius. Yanshanian granite expose widely in the south of this geothermal field and four faults cut across each other over it. A dense grid of 176 magnetotelluric (MT) sites with broadband has been acquired over the Xinzhou geothermal field and its surrounding area. Due to the related electromagnetic (EM) noise one permanent observatory was placed as a remote reference to suppress this cultural EM noise interference. The datasets are processed using the mutual reference technique, static shift correction, and structural strike and dimensionality analysis based on tensor decomposition. Data analysis reveals that the underground conductivity structure has obvious three-dimensional characterization. For the high resolution result ,two and three dimensional inversion are both applied in this area employing the non-linear conjugate gradient method (NLCG).These MT data sets are supposed to detect the deep subsurface resistivity structure correlated to the distribution of geothermal reservoir (such as faults and fractured granite) and investigate the channel of the upwelling magma. The whole and cold granite usually present high resistivity but once it functions as reservoir the resistivity will decrease, sometimes it is hard to separate the reservoir from the cap layer. The 3D inversion results delineate three high resistivity anomalies distributed in different locations. At last we put forward that the large areas of granite form the major thermal source for the study area and discuss whether any melt under these magma intrusions exists.

Faculty Perceptions of, and Experiences with, African American Male Students at a Community College

ERIC Educational Resources Information Center

Jenkins, Shantelle K.

2013-01-01

Many studies involving African American male students have focused on achievement gaps and student retention models of those attending four-year institutions. However, there are limited investigations of African American male students at the community college and very few that focus on faculty perceptions. This study employed a mixed Delphi…

Leadership Development and the African American Male College Student Experience

ERIC Educational Resources Information Center

Oaks, D'Arcy John; Duckett, Kirstan; Suddeth, Todd; Kennedy-Phillips, Lance

2013-01-01

Qualitative interviews were employed to assess the effectiveness of a leadership program geared toward African American male personal and professional development, and to examine the relationship between program participation and connectedness. Elements of both social engagement (mentoring and being mentored, peer-to-peer relationships, and…

Audio magnetotelluric study applied to hydrogeology at Santo Tomás Valley, Baja California, México

NASA Astrophysics Data System (ADS)

Islas, A. C.; Romo, J. M.

2009-12-01

The Santo Tomás valley, located 50 km southeast of Ensenada, Baja California, is one of the most important viniculture zones in all of Mexico. Therefore, aquifer characterization is very important for the area. A geophysical study was conducted using the audio-magnetotelluric method (AMT) to determinate the electric conductivity of the basin. 82 AMT stations were measured in three profiles with a North-South orientation. Data was collected using a Stratagem EH4 (by Geometrics) in frequencies between 10 Hz to 100 kHz. To determinate basement and water table depths we made 2D ground resistivity models, using an inversion regularized algorithm. The results show a conductive zone from a few meters up to depths of 200 meters; this unit can be interpreted as the aquifer zone. The models show a less conductive zone (~1000 Ohm-m) in the first 20 meters, which is interpreted as the vadose zone. Finally, we have a very resistive unit corresponding to the basement, estimated around 200 meters depth.

Gender and Racial Experiences in Executive School Leadership: Perceptions of African American Female Superintendents

ERIC Educational Resources Information Center

Colbert, Daveda Jean

2009-01-01

There is a leadership crisis that exists in our schools creating an urgent need for effective leadership. Even though African American women have made slight gains, throughout the country people of color and women are dramatically underrepresented in the superintendency. Therefore, the primary purpose of this study is to provide African American…

Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century

PubMed Central

Agyemang, C.; Bhopal, R.; Bruijnzeels, M.

2005-01-01

Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

Knowledge is (not) power: healthy eating and physical activity for African-American women.

PubMed

Barnett, Tracey Marie; Praetorius, Regina T

2015-01-01

African-American women are more likely to be overweight or obese as compared to other ethnic groups. The purpose of this Qualitative Interpretive Meta-Synthesis (QIMS) was to explore the experiences that African-American women encounter when trying to eat healthily and maintain physical activity to inform practice and research. The QIMS included studies from various disciplines to understand the experiences of African-American women with eating healthily and being physically active. Five themes were identified: family; structured support; translating knowledge into behavior modifications; barriers to physical activity; and God is my healer. These themes enhance understanding of what African-American women know, their support system(s), and how cultural barriers impact nutrition and physical activity.

A preparation zone for volcanic explosions beneath Naka-dake crater, Aso volcano, as inferred from magnetotelluric surveys

NASA Astrophysics Data System (ADS)

Kanda, Wataru; Tanaka, Yoshikazu; Utsugi, Mitsuru; Takakura, Shinichi; Hashimoto, Takeshi; Inoue, Hiroyuki

2008-11-01

The 1st crater of Naka-dake, Aso volcano, is one of the most active craters in Japan, and known to have a characteristic cycle of activity that consists of the formation of a crater lake, drying-up of the lake water, and finally a Strombolian-type eruption. Recent observations indicate an increase in eruptive activity including a decrease in the level of the lake water, mud eruptions, and red hot glows on the crater wall. Temporal variations in the geomagnetic field observed around the craters of Naka-dake also indicate that thermal demagnetization of the subsurface rocks has been occurring in shallow subsurface areas around the 1st crater. Volcanic explosions act to release the energy transferred from magma or volcanic fluids. Measurement of the subsurface electrical resistivity is a promising method in investigating the shallow structure of the volcanic edifices, where energy from various sources accumulates, and in investigating the behaviors of magma and volcanic fluids. We carried out audio-frequency magnetotelluric surveys around the craters of Naka-dake in 2004 and 2005 to determine the detailed electrical structure down to a depth of around 1 km. The main objective of this study is to identify the specific subsurface structure that acts to store energy as a preparation zone for volcanic eruption. Two-dimensional inversions were applied to four profiles across the craters, revealing a strongly conductive zone at several hundred meters depth beneath the 1st crater and surrounding area. In contrast, we found no such remarkable conductor at shallow depths beneath the 4th crater, which has been inactive for 70 years, finding instead a relatively resistive body. The distribution of the rotational invariant of the magnetotelluric impedance tensor is consistent with the inversion results. This unusual shallow structure probably reflects the existence of a supply path of high-temperature volcanic gases to the crater bottom. We propose that the upper part of the

"Teaching while Black": Narratives of African American Student Affairs Faculty

ERIC Educational Resources Information Center

Patton, Lori D.; Catching, Christopher

2009-01-01

African American faculty have historically been underrepresented within predominantly white institutions (PWIs) and deal with academic isolation, marginalization of their scholarship, and racial hostility. Little is known about the experiences of African American faculty who teach in student affairs graduate programs. The purpose of this study was…

Academic Odyssey: The Training of an African Sociologist.

ERIC Educational Resources Information Center

Woldemikael, Tekle M.

1988-01-01

Traces the author's experiences in a Eurocentric graduate training program relative to institutional pressures, cultural conflict, interactionism, and U.S. racism. Concludes that experiences caused an intellectual shift to viewpoint of a marginal Black sociologist who focuses upon the experiences and history of persons of African descent in the…

School and Peer Influences on the Academic Outcomes of African American Adolescents

PubMed Central

Estrada-Martinez, Lorena; Colin, Rosa J.; Jones, Brittni D.

2015-01-01

Little scholarship explores how adolescents’ beliefs about school and peers influence the academic outcomes of African American boys and girls. The sample included 612 African American boys (N=307, Mage=16.84) and girls (N=305, Mage=16.79). Latent class analysis (LCA) revealed unique patterns for African American boys and girls. Findings indicate that for African American boys, school attachment was protective, despite having peers who endorsed negative achievement values. Furthermore, socio-economic (SES) status was associated with higher grade point averages (GPA) for African American girls. Overall, these findings underscore the unique role of school, peer, and gendered experiences in lives of African American adolescents. PMID:26277404

Structures of the West African Craton Margin across southern Mauritania inferred from a 450-km geoelectrical profile

NASA Astrophysics Data System (ADS)

Ritz, M.; Robineau, B.; Vassal, J.; Bellion, Y.; Dukhan, M.

1989-04-01

Magnetotelluric (MT) measurements were carried out at 20 sites, extending 450 km across southern Mauritania in order to study lithospheric structures related to the West African craton (WAC) margin. The MT profile starts to the west on the Senegal-Mauritania basin (S-M basin), traverses across the Mauritanides orogenic belt, and terminates on the western border of the WAC (Taoudeni basin). Distortion effects due to local shallow inhomogeneities are present in nearly all of the basin data. In such a situation, the preliminary interpretation of the data was done by using 1D inversions based upon rotationally invariant parameters. Such distortion is not apparent for the belt and craton sites, and 1D inversions were followed by 2D modeling. The models produced reveal a clear crustal subdivision into a resistive upper crust underlain by a two-layer lower crust with two conductors, one at mid-crustal depths (supposed fluid-produced) beneath the S-M basin and the second at the base of the crust beneath the WAC. The 14-km-thick conductive material below the Mauritanides belt is interpreted as large imbricated thrusts representing the deep roots of the Mauritanides nappes. The models also show that significant contrasts in resistivity extend deep in the lithosphere between the cratonic area and the Senegal microplate.

Joint two-dimensional inversion of magnetotelluric and gravity data using correspondence maps

NASA Astrophysics Data System (ADS)

Carrillo, Jonathan; Gallardo, Luis A.

2018-05-01

An accurate characterization of subsurface targets relies on the interpretation of multiple geophysical properties and their relationships. There are mainly two links to jointly invert different geophysical parameters: structural and petrophysical relationships. Structural approaches aim at minimizing topological differences and are widely popular since they need only a few assumptions about models. Conversely, methods based on petrophysical links rely mostly on the property values themselves and can provide a strong coupling between models, but they need to be treated carefully because specific direct relationship must be known or assumed. While some petrophysical relationships are widely accepted, it remains the question whether we may be able to detect them directly from the geophysical data. Currently, there is no reported development that takes full advantage of the flexibility of jointly estimating in-situ empirical relationships and geophysical models for a given geological scenario. We thus developed an algorithm for the two dimensional joint inversion of gravity and magnetotelluric data that seeks simultaneously for a density-resistivity relationship optimal for each studied site described trough a polynomial function. The iterative two-dimensional scheme is tested using synthetic and field data from Cerro Prieto, Mexico. The resulting models show an enhanced resolution with an increased structural and petrophysical correlation. We show that by fitting a functional relationship we increased significantly the coupled geological sense of the models at a little cost in terms of data misfit.

Probabilistic Magnetotelluric Inversion with Adaptive Regularisation Using the No-U-Turns Sampler

NASA Astrophysics Data System (ADS)

Conway, Dennis; Simpson, Janelle; Didana, Yohannes; Rugari, Joseph; Heinson, Graham

2018-04-01

We present the first inversion of magnetotelluric (MT) data using a Hamiltonian Monte Carlo algorithm. The inversion of MT data is an underdetermined problem which leads to an ensemble of feasible models for a given dataset. A standard approach in MT inversion is to perform a deterministic search for the single solution which is maximally smooth for a given data-fit threshold. An alternative approach is to use Markov Chain Monte Carlo (MCMC) methods, which have been used in MT inversion to explore the entire solution space and produce a suite of likely models. This approach has the advantage of assigning confidence to resistivity models, leading to better geological interpretations. Recent advances in MCMC techniques include the No-U-Turns Sampler (NUTS), an efficient and rapidly converging method which is based on Hamiltonian Monte Carlo. We have implemented a 1D MT inversion which uses the NUTS algorithm. Our model includes a fixed number of layers of variable thickness and resistivity, as well as probabilistic smoothing constraints which allow sharp and smooth transitions. We present the results of a synthetic study and show the accuracy of the technique, as well as the fast convergence, independence of starting models, and sampling efficiency. Finally, we test our technique on MT data collected from a site in Boulia, Queensland, Australia to show its utility in geological interpretation and ability to provide probabilistic estimates of features such as depth to basement.

Behavioral studies of learning in the Africanized honey bee (Apis mellifera L.).

PubMed

Abramson, Charles I; Aquino, Italo S

2002-01-01

Experiments on basic classical conditioning phenomena in adult and young Africanized honey bees (Apis mellifera L.) are described. Phenomena include conditioning to various stimuli, extinction (both unpaired and CS only), conditioned inhibition, color and odor discrimination. In addition to work on basic phenomena, experiments on practical applications of conditioning methodology are illustrated with studies demonstrating the effects of insecticides on learning and the reaction of bees to consumer products. Electron microscope photos are presented of Africanized workers, drones, and queen bees. Possible sub-species differences between Africanized and European bees are discussed. Copyright 2002 S. Karger AG, Basel

Black South African freshmen's experience of first coitus and contraception.

PubMed

Nicholas, L

1994-01-01

An anonymous questionnaire investigating Black South African first-year college students' experience of first intercourse and contraception was administered during the February 1993 orientation at a Black university. 754 females and 959 males of mean age 20.4 years in an age range of 16-50 years participated. 96.5% of the respondents were single. The study findings relate to the 894 single students who reported having experienced sexual intercourse. Male and female respondents' mean ages at first intercourse were, respectively, 15.5 and 17.8 years. 35.7% of males and 32.8% of females reported not using contraception during first intercourse, 12.3% of males and 7.1% of females were unsure, and 6.2% reported using withdrawal. 36.8% reported not using a condom because first sexual intercourse was unplanned, while 38.1% simply did not think about contraception at the time. Peers were reported as the primary first source of learning about sexual intercourse as well as the preferred source. These findings lend support to the need to target safer sex messages to college freshmen in this setting. In so doing, safer sex behavior can be encouraged and possibly adopted before high-risk sex behavior patterns develop.

Successful African American women in science: A narrative inquiry

NASA Astrophysics Data System (ADS)

Petty, Cailisha L.

This study used narrative inquiry as a methodology to explore the lived experiences of five African American women in science across the academic spectrum, from doctoral candidate to full professor. The research questions guiding the inquiry included one overarching question and three sub-questions: What are the lifestories of successful African American women in science?; a) How do successful African American women in science define themselves?; b) What have been the facilitators and barriers encountered by successful African American women in science?; and c) What have been the systems of support for African American women in science? The study was theoretically positioned within the frameworks of Critical Race Theory and Black Feminist Thought. The two theories were used to guide all aspects of the study including methodology, data collection, and analysis. Data included eleven 40-60 minute semi-structured interview transcripts as well as the participants' Curriculum Vitae. The study design and data analysis were built upon Clandinin and Connelly's (2000) and Clandinin's (2006) model of narrative inquiry which explores narratives as a means to understand experience. Analysis and interpretation created three dominant narratives: Scientific Beginnings, An Unexpected Journey, and Lift as You Climb. Each narrative set explores multiple stories that describe storylines which aligned with the participants' goals of who they were and who they were becoming as scientists; and, storylines of tension which ran counter to the women's goals and aspirations. Barriers and support systems are revealed, as well as the meanings the participants made of their experiences and how it affected their lives.

Magnetotelluric investigation across the Agri Valley: preliminary results.

NASA Astrophysics Data System (ADS)

Balasco, Marianna; Romano, Gerardo; Siniscalchi, Agata; Alfredo Stabile, Tony

2017-04-01

The Agri Valley is an axial zone of the Southern Apennines thrust belt chain with a strong seismogenic potential where two important energy technologies responsible for inducing/triggering seismicity are active: (1) the disposal at the Costa Molina 2 injection well of the wastewater produced during the exploitation of the biggest onshore oil field in west Europe (27 wells producing more than 80,000 barrels of crude oil per day), managed by the Eni S.p.A., and (2) the water loading and unloading operations in the Pertusillo artificial reservoir. It is recognized the possibility that the fluctuation of the water level inside the reservoir, due to the hydrological cycle for example, produces pressure perturbations at the bottom of reservoir, causing induced seismicity. Furthermore it is even more known the role of fluids in the rupture processes which could cause an increase of pore pressure specially at high rate of injection fluids and/or for the presence of weakening of preexisting faults. With the aim to better characterize and understand the physical processes involved in the observed induced/triggered seismicity, in 2016 a broadband seismic network, covering an area of about 20 km x 20 km nearby the Pertusillo Dam and Costa Molina2 well has been installed in the framework of SIR-MIUR project INSIEME (INduced Seismicity in Italy: Estimation, Monitoring, and sEismic risk mitigation) and a MagnetoTelluric (MT) survey has been performed. The MT investigation consists of 25 soundings aligned along 30 km profile oriented at about N40 direction, orthogonal with the strike of the major and noticeable geological structures and crossing both of the source that may induce/trigger seismicity. In this work, we present the preliminary 2D resistivity model which provides useful deep geophysical information for understanding the geological and structural setting of the Agri Valley. Moreover, the comparison of the resistivity model with the earthquake location as inferred from

Imaging Ancient Sutures with EarthScope Transportable Array Magnetotelluric Data

NASA Astrophysics Data System (ADS)

Egbert, G. D.

2014-12-01

Magnetotellurics (MT) provides a powerful geophysical tool for imaging of ancient suture zones, which are frequently marked by elongated zones of very low resistivity. These conductive anomalies, which can extend to great depths and have apparently persisted for several billion years, most likely result from graphite and sulfides deeply emplaced and remobilized, through subduction, accretion and orogenesis. The Earthscope MT transportable array provides a unique broad-scale view of sutures in the continental US. In the northwestern US subvertical conductive features bound all of the major cratonic blocks. These can be identified with the Cheyenne Belt between the Wyoming Craton (WC) and Yavapai Terranes (YT), the Great Falls Tectonic Zone between WC and the Medicine Hat Block (MHB), and the Vulcan Structure of southern Alberta between MHB and the Hearne Craton. In all cases the conductive anomalies extend well into the mantle lithosphere. The more recent MT TA footprint in the north-central US (surrounding the Mid-Continent Rift (MCR)) also reveals conductive signatures of ancient sutures. The most prominent lies south of Lake Superior, just north of the Niagara Fault (NF), and can be associated with the Penokean Orogeny (~1.85 Ga). A second, further south beneath Iowa and western Wisconsin, just south of the Spirit Lake tectonic zone (SLtz), can be identified with YT accretion (~1.75 Ga). Both of these sutures are cleanly cut by the MCR. The break in the anomalies is narrow (comparable to the surface expression of the MCR) indicating that rifting impacts on the entire crustal section were highly localized. The south-dipping NF conductive anomaly extends from surface outcrop to at least the Moho. The SLtz anomaly is north-dipping, extending from mid-crust through the Moho. In both cases there is some evidence for a modestly conductive layer (likely carbon) thrust to mid-lithospheric depths within the overriding terrane.

Detectability of Wellbore CO2 Leakage using the Magnetotelluric Method

NASA Astrophysics Data System (ADS)

Yang, X.; Buscheck, T. A.; Mansoor, K.; Carroll, S.

2016-12-01

We assessed the effectiveness of the magnetotelluric (MT) method in detecting CO2 and brine leakage through a wellbore, which penetrates a CO2 storage reservoir, into overlying aquifers, 0 to 1720 m in depth, in support of the USDOE National Risk Assessment Partnership (NRAP) monitoring program. Synthetic datasets based on the Kimberlina site in the southern San Joaquin Basin, California were created using CO2 storage reservoir models, wellbore leakage models, and groundwater/geochemical models of the overlying aquifers. The species concentrations simulated with the groundwater/geochemical models were converted into bulk electrical conductivity (EC) distributions as the MT model input. Brine and CO2 leakage into the overlying aquifers increases ion concentrations, and thus results in an EC increase, which may be detected by the MT method. Our objective was to estimate and maximize the probability of leakage detection using the MT method. The MT method is an electromagnetic geophysical technique that images the subsurface EC distribution by measuring natural electric and magnetic fields in the frequency range from 0.01 Hz to 1 kHz with sensors on the ground surface. The ModEM software was used to predict electromagnetic responses from brine and CO2 leakage and to invert synthetic MT data for recovery of subsurface conductivity distribution. We are in the process of building 1000 simulations for ranges of permeability, leakage flux, and hydraulic gradient to study leakage detectability and to develop an optimization method to answer when, where and how an MT monitoring system should be deployed to maximize the probability of leakage detection. This work was sponsored by the USDOE Fossil Energy, National Energy Technology Laboratory, managed by Traci Rodosta and Andrea McNemar. This work was performed under the auspices of the USDOE by LLNL under contract DE-AC52-07NA27344. LLNL IM release number is LLNL-ABS-699276.

Immersion and Identity: Experiences of an African American Preschool Child

ERIC Educational Resources Information Center

McCullough, Ruanda Garth; Reyes, Sharon Adelman

2010-01-01

This article explores the benefits and challenges of a Spanish language immersion preschool from the perspective of a non-Spanish speaking African American family. Data explored include the decision to enroll, reactions from peers and family, home-school communication issues, language development, and family involvement. In addition,…

Audio-frequency magnetotelluric imaging of the Hijima fault, Yamasaki fault system, southwest Japan

NASA Astrophysics Data System (ADS)

Yamaguchi, S.; Ogawa, Y.; Fuji-Ta, K.; Ujihara, N.; Inokuchi, H.; Oshiman, N.

2010-04-01

An audio-frequency magnetotelluric (AMT) survey was undertaken at ten sites along a transect across the Hijima fault, a major segment of the Yamasaki fault system, Japan. The data were subjected to dimensionality analysis, following which two-dimensional inversions for the TE and TM modes were carried out. This model is characterized by (1) a clear resistivity boundary that coincides with the downward projection of the surface trace of the Hijima fault, (2) a resistive zone (>500 Ω m) that corresponds to Mesozoic sediment, and (3) shallow and deep two highly conductive zones (30-40 Ω m) along the fault. The shallow conductive zone is a common feature of the Yamasaki fault system, whereas the deep conductor is a newly discovered feature at depths of 800-1,800 m to the southwest of the fault. The conductor is truncated by the Hijima fault to the northeast, and its upper boundary is the resistive zone. Both conductors are interpreted to represent a combination of clay minerals and a fluid network within a fault-related fracture zone. In terms of the development of the fluid networks, the fault core of the Hijima fault and the highly resistive zone may play important roles as barriers to fluid flow on the northeast and upper sides of the conductive zones, respectively.

Distribution of melt beneath Mount St Helens and Mount Adams inferred from magnetotelluric data

USGS Publications Warehouse

Hill, G.J.; Caldwell, T.G.; Heise, W.; Chertkoff, D.G.; Bibby, H.M.; Burgess, M.K.; Cull, J.P.; Cas, Ray A.F.

2009-01-01

Three prominent volcanoes that form part of the Cascade mountain range in Washington State (USA)Mounts StHelens, Adams and Rainierare located on the margins of a mid-crustal zone of high electrical conductivity1,5. Interconnected melt can increase the bulk conductivity of the region containing the melt6,7, which leads us to propose that the anomalous conductivity in this region is due to partial melt associated with the volcanism. Here we test this hypothesis by using magnetotelluric data recorded at a network of 85 locations in the area of the high-conductivity anomaly. Our data reveal that a localized zone of high conductivity beneath thisvolcano extends downwards to join the mid-crustal conductor. As our measurements were made during the recent period of lava extrusion at Mount St Helens, we infer that the conductivity anomaly associated with the localized zone, and by extension with the mid-crustal conductor, is caused by the presence of partial melt. Our interpretation is consistent with the crustal origin of silicic magmas erupting from Mount St Helens8, and explains the distribution of seismicity observed at the time of the catastrophic eruption in 1980 (refs9, 10). ?? 2009 Macmillan Publishers Limited. All rights reserved.

On the detectability of Teide volcano magma chambers (Tenerife, Canary Islands) with magnetotelluric data

NASA Astrophysics Data System (ADS)

Piña-Varas, Perla; Ledo, Juanjo; Queralt, Pilar; Marcuello, Alex; Perez, Nemesio

2018-01-01

Tenerife has been the subject of numerous studies covering a wide range of fields. Many studies have been focused on characterising the magmatic plumbing system. Even so, a controversy still exists regarding the location and size of the current magma chambers. Several magnetotelluric (MT) surveys have been carried out in the island, but no conductivity anomalies associated with the chambers have been detected. We report the results of a set of tests conducted against the 3-D resistivity model of the island, to determine the characteristics of the detectable chambers with the MT data. The most remarkable results indicate that the MT dataset is incompatible with a large-scale mafic reservoir located at shallower depths than 8 km b.s.l. However, shallower phonolitic chambers smaller than 3 × 3 × 1 km3 could be undetected by the existing MT sites and new data should be acquired to confirm or not their existence. This new information is essential in volcanic islands like Tenerife, since many volcanic hazards are related to the size and depth of the sources of magma. Additionally, a joint interpretation of the obtained results together with other information is summarised in a hypothetical model, allowing us to better understand the internal structure of the island.[Figure not available: see fulltext.

Joint Interpretation of Magnetotelluric and Gravimetric Data from the South American Paraná Basin

NASA Astrophysics Data System (ADS)

Santos, E. B.; Santos, H. B.; Vitorello, I.; Pádua, M. B.

2013-05-01

The Paraná Basin is a large sedimentary basin in central-eastern South America that extends through Brazil, Paraguay, Uruguay and Argentina. Evolved completely over the South American continental crust, this Paleozoic basin is filled with sedimentary and volcanic rocks deposited from the Silurian to the Cretaceous, when a significant basaltic effusion covered almost the entire area of the basin. A series of superposed sedimentary and volcanic rock layers were laid down under the influence of different tectonic settings, probably originated from distant collisional dynamics of continental boards that led to the amalgamation of Gondwanaland. The current boundaries of the basin can be the result of issuing erosional or of tectonic origin, such as the building up of large arches and faults. To evaluate the deep structural architecture of the lithosphere under a sedimentary basin is a great challenge, requiring the integration of different geophysical and geological studies. In this paper, we present the resulting Paraná Basin lithospheric model, obtained from processing and inversion of broadband and long-period magnetotelluric soundings along an E-W profile across the central part of the basin, complemented by a qualitative joint interpretation of gravimetric data, in order to obtain a more precise geoelectric model of the deep structure of the region.

Analysis and application of impedance polar diagram and zstrike rose diagram of magnetotellurics data in southern part of the Wayang Windu geothermal field

NASA Astrophysics Data System (ADS)

Rohayat, O. R.; Wicaksono, R. A.; Daud, Y.

2018-03-01

In this study, we determined the main direction of geoelectric strike in the southern part of the Wayang Windu geothermal field using magnetotellurics (MT) data. The strike direction was obtained by analyzing data using impedance polar and Zstrike rose diagram. We investigated 51 MT data at different sites of the southern part of the Wayang Windu geothermal field. Determination of geoelectric strike direction is important since the strike is the rotation references in MT data processing. Our findings had pointed out that the geoelectric strike direction in this study area is in accordance with the direction of geological structure and has a good correlation with structures delineated from 3D MT inversion model.

The Southern Washington Cascades magmatic system imaged with magnetotellurics

NASA Astrophysics Data System (ADS)

Bowles-martinez, E.; Bedrosian, P.; Schultz, A.; Hill, G. J.; Peacock, J.

2016-12-01

The goal of the interdisciplinary iMUSH project (Imaging Magma Under Saint Helens) is to image the magmatic system of Mount Saint Helens (MSH), and to determine the relationship of this system to the greater Cascades volcanic arc. We are especially interested in an anomalously conductive crustal zone between MSH and Mount Adams known as the Southern Washington Cascades Conductor (SWCC), which early studies interpreted as accreted sediments, but more recently has been interpreted as a broad region of partial melt. MSH is located 50 km west of the main arc and is the most active of the Cascade volcanoes. Its 1980 eruption highlighted the need to understand this potentially hazardous volcanic system. We use wideband magnetotelluric (MT) data collected in 2014-2015 along with data from earlier studies to create a 3D model of the electrical resistivity throughout the region, covering MSH as well as Mount Adams and Mount Rainier along the main volcanic arc. We look at not only the volcanoes themselves, but also their relationship to one another and to regional geologic structures. Preliminary modeling identifies several conductive features, including a mid-crustal conductive region between MSH and Mount Adams that passes below Indian Heaven Volcanic Field and coincides with a region with a high Vp/Vs ratio identified in the seismic component of iMUSH. This suggests that it could be magmatic, but does not preclude the possibility of conductive sediments. Synthesis of seismic and MT data to address this question is ongoing. We also note a conductive zone running north-south just west of MSH that is likely associated with fluids within faults of the Saint Helens Seismic Zone. We finally note that curvature of the conductive lineament that defines the main Cascade arc suggests that the boundary of magmatism is influenced by compression within the Yakima Fold and Thrust Belt, east and southeast of Mount Adams.

The magnetotelluric response over a 3D polarizable structure

NASA Astrophysics Data System (ADS)

Esposito, R.; Troiano, A.; Di Giuseppe, M. G.; Patella, D.; Castelo Branco, R. M.

2017-06-01

This paper analyses the 3D magnetotelluric (MT) response in the presence of resistivity frequency dispersion. The aim is to give further insight into this topic, already approached in previous papers dedicated to 1D and 2D cases. We show the MT diagrams along three parallel profiles, normal to the longitudinal axis of a dispersive conductive prism of finite horizontal and vertical extent, buried in a non-dispersive resistive half-space. The Cole-Cole dispersion law has been assumed to represent the dispersion features of the prism. The MT responses along the same profiles in the complete absence of dispersion effects are also provided for reference. The results confirm that the TE mode, as in the 2D case, is mostly affected by dispersion. Compared with the non-dispersive responses, a notable increase in the amplitude of the anomaly is observed along the profile passing through the center of the prism, while an increase in its width is the effect along the profile above the edge of the prism. As a field example, the MT profile in the eastern Snake River Plain geothermal area is considered. The profile was already dealt with in a previous paper by a 2D dispersive MT modeling approach, by which a dispersive slab of infinite length in the direction normal to the MT profile, immersed in a 1D layered host, was modeled. A finite length of the dispersive conductive slab is now derived, validated by the increased goodness of fit between the field TM and TE pseudosections and the synthetic ones from the 3D model compared with the misfit previously obtained by the 2D approach. Finally, an explanation of the chargeability and main values of the time constant assumed to fit the field data is attempted in terms of the abundance of hydrothermal alteration products and temperature, respectively, inside the dispersive slab.

Semiautomatic approaches to account for 3-D distortion of the electric field from local, near-surface structures in 3-D resistivity inversions of 3-D regional magnetotelluric data

USGS Publications Warehouse

Rodriguez, Brian D.

2017-03-31

This report summarizes the results of three-dimensional (3-D) resistivity inversion simulations that were performed to account for local 3-D distortion of the electric field in the presence of 3-D regional structure, without any a priori information on the actual 3-D distribution of the known subsurface geology. The methodology used a 3-D geologic model to create a 3-D resistivity forward (“known”) model that depicted the subsurface resistivity structure expected for the input geologic configuration. The calculated magnetotelluric response of the modeled resistivity structure was assumed to represent observed magnetotelluric data and was subsequently used as input into a 3-D resistivity inverse model that used an iterative 3-D algorithm to estimate 3-D distortions without any a priori geologic information. A publicly available inversion code, WSINV3DMT, was used for all of the simulated inversions, initially using the default parameters, and subsequently using adjusted inversion parameters. A semiautomatic approach of accounting for the static shift using various selections of the highest frequencies and initial models was also tested. The resulting 3-D resistivity inversion simulation was compared to the “known” model and the results evaluated. The inversion approach that produced the lowest misfit to the various local 3-D distortions was an inversion that employed an initial model volume resistivity that was nearest to the maximum resistivities in the near-surface layer.

A Qualitative Study of African American Women in Engineering Technology Programs in Community Colleges

ERIC Educational Resources Information Center

Blakley, Jacquelyn

2016-01-01

This study examined the experiences of African American women in engineering technology programs in community colleges. There is a lack of representation of African American women in engineering technology programs throughout higher education, especially in community/technical colleges. There is also lack of representation of African American…

Digital expression among urban, low-income African American adolescents.

PubMed

Baker, Christina M; Staiano, Amanda E; Calvert, Sandra L

2011-01-01

Digital production is a means through which African American adolescents communicate and express their experiences with peers. This study examined the content and the form of the digital productions of 24 urban, low-income African American adolescents who attended a summer academic program. The content of student digital productions focused on academic experiences and friendships. Their production styles revealed that youth used perceptually salient production features, such as rapid scene changes and loud rap music. The results suggest that when placed in a supportive, academic environment and provided with digital production resources, students who traditionally face barriers due to cultural and economic inequalities digitally express to their peers an interest in academics and positive peer relationships, and that these youth communicate their experiences through a shared production style that reflects their broader cultural experiences.

In/dependent Collaborations: Perceptions and Experiences of African Scientists in Transnational HIV Research

PubMed Central

Moyi Okwaro, Ferdinand; Geissler, P. W.

2015-01-01

This article examines collaboration in transnational medical research from the viewpoint of African scientists working in partnerships with northern counterparts. It draws on ethnographic fieldwork in an HIV laboratory of an East African state university, with additional data from interviews with scientists working in related research institutions. Collaboration is today the preferred framework for the mechanisms by which northern institutions support research in the south. The concept signals a shift away from the legacy of unequal (post‐) colonial power relations, although, amid persisting inequalities, the rhetorical emphasis on equality might actually hinder critical engagement with conflicts of interest and injustice. To collaborate, African scientists engage various strategies: They establish a qualified but flexible, non‐permanent workforce, diversify collaborators and research areas, source complementary funding to assemble infrastructures, and maintain prospective research populations to attract transnational clinical trials. Through this labor of collaboration, they sustain their institutions under prevailing conditions of scarcity. PMID:25800667

Loss of Trust in the Neighborhood: The Experience of Older African Americans in Detroit.

PubMed

Fritz, Heather; Cutchin, Malcolm P; Cummins, Emily R

2018-02-19

Although evidence suggests that neighborhood conditions are related to stress and health, the processes connecting neighborhood conditions and stress for older minorities is little explored. The purpose of this analysis is to contribute new insights into this issue. We conducted a qualitative analysis as part of a larger mixed methods study of 100 African Americans aged 55 and older living in neighborhoods of varying quality in Detroit, Michigan. A subsample of (n = 20) older adults took photographs of bothersome aspects of their neighborhoods and participated in in-depth photo-elicitation interviews. Data were analyzed using a grounded theory approach. 'Loss of trust in the neighborhood' emerged as the core category to explain how older African Americans in our sample experienced neighborhood stressors in their daily lives. Loss of trust in physical, social, and institutional dimensions of the neighborhood contributed to the core category. The life course of neighborhoods and the trust placed in them appears to be intimately connected to the well-being of older African Americans. We therefore hypothesize that a fundamental pathway through which neighborhood stressors are experienced for older African Americans in U.S. 'Rust Belt' cities is the multifaceted loss of trust in the neighborhood.

Increasing Prosocial Behavior and Academic Achievement among Adolescent African American Males

ERIC Educational Resources Information Center

Martin, Don; Martin, Magy; Gibson, Suzanne Semivan; Wilkins, Jonathan

2007-01-01

African American adolescents disproportionately perform poorly compared to peers in both behavioral and academic aspects of their educational experience. In this study, African American male students participated in an after-school program involving tutoring, group counseling, and various enrichment activities. All students were assessed regarding…

A Phenomenologicial Narrative Study of African American Male Community College Instructors

ERIC Educational Resources Information Center

Wallace, Jerry L.

2014-01-01

This qualitative phenomenological research study used narrative inquiry to explore the lived experiences of African American male community college instructors using interviews, classroom observations, and personal testimonies conducted at a Southeast Texas community college. Brown (2009) previously conducted a study on African American male…

The Cultural Relevance of Mindfulness Meditation as a Health Intervention for African Americans

PubMed Central

Woods-Giscombé, Cheryl L.; Gaylord, Susan A.

2014-01-01

African Americans experience a disproportionate rate of stress-related health conditions compared to European Americans. Mindfulness meditation has been shown to be effective for managing stress and various stress-related health conditions. This study explored the cultural relevance of mindfulness meditation training for African Americans adults. Fifteen African American adults with past or current experience with mindfulness meditation training were interviewed. Participants felt that mindfulness meditation helped them with enhanced stress management, direct health improvement, and enhanced self-awareness and purposefulness. They felt that they would recommend it and that other African Americans would be open to the practice but suggested that its presentation may need to be adapted. They suggested emphasizing the health benefits, connecting it to familiar spiritual ideology and cultural practices, supplementing the reading material with African American writers, increasing communication (education, instructor availability, “buddy system,” etc.), and including African Americans as instructors and participants. By implementing minor adaptations that enhance cultural relevance, mindfulness meditation can be a beneficial therapeutic intervention for this population. PMID:24442592

Y Chromosome Lineages in Men of West African Descent

PubMed Central

Keita, Shomarka O. Y.; Kittles, Rick A.

2012-01-01

The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called “Grain Coast” of western Africa (Senegal to Sierra Leone). Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations), 188 Caribbeans (from 2 islands), 532 African Americans (AAs from Washington, DC and Columbia, SC), and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30–40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations. PMID:22295064

Y chromosome lineages in men of west African descent.

PubMed

Torres, Jada Benn; Doura, Menahem B; Keita, Shomarka O Y; Kittles, Rick A

2012-01-01

The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called "Grain Coast" of western Africa (Senegal to Sierra Leone). Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations), 188 Caribbeans (from 2 islands), 532 African Americans (AAs from Washington, DC and Columbia, SC), and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30-40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations.

RELATIONAL SCHEMAS, HOSTILE ROMANTIC RELATIONSHIPS, AND BELIEFS ABOUT MARRIAGE AMONG YOUNG AFRICAN AMERICAN ADULTS

PubMed Central

Simons, Ronald L.; Simons, Leslie Gordon; Lei, Man Kit; Landor, Antoinette

2011-01-01

The present study tests a developmental model designed to explain the romantic relationship difficulties and reluctance to marry often reported for African Americans. Using longitudinal data from a sample of approximately 400 African American young adults, we examine the manner in which race-related adverse experiences during late childhood and early adolescence give rise to the cynical view of romantic partners and marriage held by many young African Americans. Our results indicate that adverse circumstances disproportionately suffered by African American youth (viz., harsh parenting, family instability, discrimination, criminal victimization, and financial hardship) promote distrustful relational schemas that lead to troubled dating relationships, and that these negative relationship experiences, in turn, encourage a less positive view of marriage. PMID:22328799

Perceived Racism as a Predictor of Paranoia among African Americans

ERIC Educational Resources Information Center

Combs, Dennis R.; Penn, David L.; Cassisi, Jeffrey; Michael, Chris; Wood, Terry; Wanner, Jill; Adams, Scott

2006-01-01

Recent theoretical models suggest that perceived racism acts as a stressor for African Americans and may be associated with a variety of negative psychological consequences, notably paranoia. Paranoia among African Americans is believed to reflect the lower end of the paranoia continuum based on experiences with racism. Thus, it may be beneficial…

Positionality of African Americans and a Theoretical Accommodation of It: Rethinking Science Education Research

ERIC Educational Resources Information Center

Parsons, Eileen R. Carlton

2008-01-01

This essay addresses a call for research involving African Americans to interpret data from the historical, contemporary, and cultural experiences of African Americans. The essay argues for a science education research approach that explicitly considers the positionality of African Americans in the United States. This positionality involves the…

Magnetotelluric Studies of Fault Zones Surrounding the 2016 Pawnee, Oklahoma Earthquake

NASA Astrophysics Data System (ADS)

Evans, R. L.; Key, K.; Atekwana, E. A.

2016-12-01

Since 2008, there has been a dramatic increase in earthquake activity in the central United States in association with major oil and gas operations. Oklahoma is now considered one the most seismically active states. Although seismic networks are able to detect activity and map its locus, they are unable to image the distribution of fluids in the fault responsible for triggering seismicity. Electrical geophysical methods are ideally suited to image fluid bearing faults since the injected waste-waters are highly saline and hence have a high electrical conductivity. To date, no study has imaged the fluids in the faults in Oklahoma and made a direct link to the seismicity. The 2016 M5.8 Pawnee, Oklahoma earthquake provides an unprecedented opportunity for scientists to provide that link. Several injection wells are located within a 20 km radius of the epicenter; and studies have suggested that injection of fluids in high-volume wells can trigger earthquakes as far away as 30 km. During late October to early November, 2016, we are collecting magnetotelluric (MT) data with the aim of constraining the distribution of fluids in the fault zone. The MT technique uses naturally occurring electric and magnetic fields measured at Earth's surface to measure conductivity structure. We plan to carry out a series of short two-dimensional (2D) profiles of wideband MT acquisition located through areas where the fault recently ruptured and seismic activity is concentrated and also across the faults in the vicinity that did not rupture. The integration of our results and ongoing seismic studies will lead to a better understanding of the links between fluid injection and seismicity.

High resolution imaging of the Methana volcanic complex, Greece, with magnetotelluric and aeromagnetic data

NASA Astrophysics Data System (ADS)

Efstathiou, A.; Tzanis, A.; Chailas, S.; Lagios, E.; Stamatakis, M.

2012-04-01

The Methana calc-alkaline volcanic complex is located off the NE coast of Argolis Peninsula (Peloponnesus, Greece) at the NW terminus of the Hellenic Volcanic Arc (HVA). It consists of approximately 32 domes, with the most recent eruptive episodes dated to 258 BCE and 1700 CE. Herein, we report the results an attempt to investigate the volcano's interior with joint interpretation of Magnetotelluric and Aeromagnetic data. The aeromagnetic data was inverted with the UBC-GIF 3D magnetic inversion suite, constrained by several in-situ susceptibility measurements. At depths to 2 km, the inversion resolves individual intrusions corresponding to known phases of volcanic activity (domes), with susceptibilities >0.1. At depths greater than 4.5 km, a more weakly magnetized domain is detected (~0.025); its ceiling is well resolved; its floor cannot be placed with certainty but extends to at least 7 km. The depths are comparable to those of magma chambers. Based on the palaeomagnetic analysis of nearby volcanic rocks, it may be safely suggested that its temperature should not be higher than 550-600°C, but also not considerably lower. It may comprise a magma chamber, inasmuch as it compares well with the temperatures and locations of known magma chambers along the HVA. Finally, there's exists evidence of the location of the vents through which the extrusive activity has taken place. A Magnetotelluric survey comprising 14 stations was conducted IN 1992, as part of a geothermal project. Herein, this data is reevaluated with modern analysis methods and re-interpreted with 2D inversion. The results indicate the presence of conductors at depths of 1500-2500 m beneath the centre of the Peninsula, extensive horizontal conductors at, or just below sea level and conductive protrusions above sea level. The joint interpretation of the susceptibility and geoelectric images is based on the premise that they both are generated by hydrothermal circulation which depresses resistivity and

Narratives of grieving African-Americans about racism in the lives of deceased family members.

PubMed

Rosenblatt, Paul C; Wallace, Beverly R

2005-04-01

As part of a comprehensive interview study on African-American grief, the authors explored how racism is incorporated into narratives about a deceased family member. To the extent that experiences of racism are pervasive in African-American life and to the extent that narratives about a person who has died generally account for the life experiences, achievements, character, and challenges faced by the deceased, the authors expected narratives about a deceased African-American to deal with the person's encounters with racism. In fact, most of the 26 African-Americans who were interviewed spoke about racism in the life of the deceased. Many talked about racism blocking the deceased from getting ahead occupationally and in other ways and about how the deceased resisted or stood up to racism. Some people spoke about the ways the deceased taught them to deal with racism. The narratives that indicated that the deceased had rarely or ever talked about racism still made clear that the deceased lived in a racist world but chose not to bring racism into family conversation. The findings suggest that a view of African-American grieving that is insensitive to racism in African-American experience may lead to unhelpful grief support or counseling.

Life Experiences of People Who Stutter, and the Perceived Impact of Stuttering on Quality of Life: Personal Accounts of South African Individuals

ERIC Educational Resources Information Center

Klompas, Michelle; Ross, Eleanor

2004-01-01

The purpose of the study was to investigate the life experiences of a group of South African adults who stutter and the impact of stuttering on their quality of life. Participants were 16 adults with a mean age of 28.9 and ranging from 20 to 59 years. Methods involved individual interviews designed to explore the life domains of education; social…

Institutional Factors That Affect the Mathematical Achievement of African American Females

ERIC Educational Resources Information Center

Chatman, Audrey

2011-01-01

This dissertation explored how institutional factors impact the mathematical achievement of African American middle school females. The purpose of the research was to provide insight into African American females' perception of their mathematics experiences and demonstrate how both internal and external factors contribute to their achievement.…

When Aspiration Meets Opportunity: Examining Transitional Experiences of African American Males in College Readiness Programs

ERIC Educational Resources Information Center

Baber, Lorenzo DuBois

2014-01-01

The lack of postsecondary success for African American males has garnered significant attention from academic scholars and public policy leaders. While this scholarship provides a strong portrait on issues related to African American males, there are still significant gaps to be addressed. Most notably, current research tends to focus on students…

"Too blessed to be stressed": a rural faith community's views of African-American males and depression.

PubMed

Bryant, Keneshia; Haynes, Tiffany; Greer-Williams, Nancy; Hartwig, Mary S

2014-06-01

Among African-Americans, the faith community has a long history of providing support to its members. Because African-American men tend to delay and decline traditional depression treatment, the faith community may be an effective source of support. The aim of this study was to determine how a rural African-American faith community describes and perceives experiences of depression among African-American males. A convenience sample of 24 men and women participated in focus groups and interview. Four themes were identified: defining depression, etiology of depression, denial of depression, and effect of masculine roles on depression experience.

African American Students in Private, Independent Schools: Parents and School Influences on Racial Identity Development

ERIC Educational Resources Information Center

DeCuir-Gunby, Jessica T.; Martin, Pamela P.; Cooper, Shauna M.

2012-01-01

Although much research has focused on the public school experiences of African American students, few studies exist that explore their race-related experiences within an independent, private school context. Studies have suggested that, while private, independent schools may elevate the quality of African American students' education, many of these…

Racial discrimination predicts greater systemic inflammation in pregnant African American women.

PubMed

Giurgescu, Carmen; Engeland, Christopher G; Templin, Thomas N; Zenk, Shannon N; Koenig, Mary Dawn; Garfield, Lindsey

2016-11-01

Chronic exposure to racial discrimination by pregnant African American women may lead to allostatic overload; thereby, predisposing women to systemic inflammation. Thus, the goal of this study was to examine if experiences of racial discrimination are related to systemic inflammation in pregnant African Americans. A sample of 96 African American women from Chicago completed questionnaires and had blood drawn during the second trimester of pregnancy (19.7±2.5 weeks). Experiences of racial discrimination were associated with higher cytokine levels of interleukin (IL)-4 (B=2.161, 95% CI = 1.02-3.30, p<.001) and IL-6 (B=1.859, 95% CI=.61-3.11, p=.004) when controlling for covariates. These findings suggest that experiences of racial discrimination may cause physiological wear and tear on the body leading to alteration of immune functions. Nurses should inquire about women's experiences of racial discrimination and make referrals for community or church support groups for women who report racial discrimination. Copyright © 2016 Elsevier Inc. All rights reserved.

Jumping through Hoops: College Choice Experiences of African American Male Community College Club Basketball Players

ERIC Educational Resources Information Center

Ellis, Kimberly Carlotta

2011-01-01

This study aimed to learn what factors influenced the college choice decision-making process of African American male club basketball players in the community college. To understand how the participants determined their educational path, face-to-face interviews were conducted with 21 African American male students who were enrolled in at least six…

Perceived Racism and Ambulatory Blood Pressure in African American College Students

ERIC Educational Resources Information Center

Hill, LaBarron K.; Kobayashi, Ihori; Hughes, Joel W.

2007-01-01

Experiences with racial discrimination may contribute to stress-induced blood pressure (BP) elevations among African Americans. It was reported that perceived racism was associated with ambulatory BP (ABP) during waking hours. This study examined perceived racism and ABP among 40 African American college students, who completed an ABP assessment…

African American Learners in Special Education: A Closer Look at Milwaukee

ERIC Educational Resources Information Center

Obiakor, Festus E.; Harris, Mateba K.; Offor, MaxMary T.; Beachum, Floyd D.

2010-01-01

Problems facing African American students with special needs are numerous and complex. Although processes and procedures are in place to properly serve these students, far too many become ensnared in webs of bureaucracy and benign neglect. This article examines African American students? experiences with special education in Milwaukee Public…

Geometries of geoelectrical structures in central Tibetan Plateau from INDEPTH magnetotelluric data

NASA Astrophysics Data System (ADS)

Vozar, Jan; Jones, Alan G.; Le Pape, Florian

2013-04-01

Magnetotelluric (MT) data collected on N-S profiles crossing the Banggong-Nujiang Suture, which separates the Qiangtang and Lhasa Terranes in central Tibet, as a part of InterNational DEep Profiling of Tibet and the Himalaya project (INDEPTH) are modeled by 2D and 3D inversion codes. The 2D deep MT model of line 500 confirms previous observations concluding that the region is characterized to first-order by a resistive upper crust and a conductive, partially melted, middle to lower crust that extends from the Lhasa Terrane to the Qiangtang Terrane with varying depth. The same conductive structure setting, but in shallower depths is also present on the eastern 400 line. From deep electromagnetic sounding, supported by independent 1D integrated petro-physical investigation, we can estimate the next upper-mantle conductive layer at depths from 200 km to 250 km below the Lhasa Terrane and less resistive Tibetan lithosphere below the Qiangtang Terrane with conductive upper-mantle in depths about 120 km. The anisotropic 2D modeling reveals lower crustal anisotropy in Lhasa Terrane, which can interpreted as crustal channel flow. The 3D inversion models of all MT data from central Tibet show dominant 2D regional strike of mid and lower crustal structures equal N110E. This orientation is parallel to Shuanghu suture, BengCo Jiali strike-slip fault system and perpendicular to convergence direction. The lower crust conductor in central Lhasa Terrane can be interpreted more likely as 3D lower Indian crust structure, located to the east from line 500, than geoelectrical anisotropic crustal flow.

Preliminary Results of a Magnetotelluric Survey in the Center of Hawaii Island

NASA Astrophysics Data System (ADS)

Lienert, B. R.; Thomas, D. M.; Wallin, E.

2014-12-01

From 2013 up to the present we have been recording magnetotelluric (MT) data at 25 sites in a 35x25 km region (elev. 1943 m) on the saddle between the active volcano of Mauna Loa (4169 m) and the dormant volcano of Mauna Kea (4205 m) on Hawai'i Island. The MT data, particularly the electric fields, are frequently contaminated by spurious components that are not due to the plane-wave magnetic signals required for derivation of the MT impedance tensor. We therefore developed interactive graphical software (MTPlot) to plot and analyze the MT signals in the field. MTPlot allows us to quickly examine records in both the time and frequency domain to in order to judge their quality. It also transforms the data into estimates of apparent resistivity and their error in the frequency range 0.001-500 Hz. This has proved very useful for selecting suitable records for subsequent analysis. We then use multi-taper remote reference processing to obtain our final apparent resistivity estimates and their errors. We present preliminary results of one and two dimensional modeling of these estimates to obtain the three-dimensional distribution of subsurface resistivities down to depths of 5 km. The results are compared to temperatures and properties of cores obtained when we drilled a research hole to a depth of 1760 m in this same region. We shall discuss how our results relate to the extent of the fresh-water and geothermal energy reservoirs that we discovered during drilling.

Sexual Decision Making in the Absence of Choice: The African American Female Dating Experience

PubMed Central

Andrasik, Michele P.; Nguyen, Hong V.; George, William H.; Kajumulo, Kelly F.

2016-01-01

Although links between low mate availability and increased HIV and STI risk for African American women have been documented in the literature, we know little about the impact of limited mate choices on the quality of relationships between Black men and women and how these relationship dynamics impact risk for young Black women. We conducted a qualitative study with African American female young adults (N=12) to explore the perceived impact of structural forces on African American female young adults’ dating and sexual behavior. Participants reported (1) perceptions of Black men as untrustworthy and manipulative, (2) the limited and often negative roles for Black men in the larger Black community, and (3) heterosexual relationships in the Black community as increasingly influenced by economics and commerce. Recommendations for HIV prevention interventions that include micro and macro level approaches are discussed. PMID:27182463

Omphalocele: experience in the African tropics

PubMed Central

Ihekwaba, F. Nwabueze

1981-01-01

Omphalocele, the congenital anomaly of the anterior abdominal wall in the newborn, is a serious condition with a grave prognosis. Sac rupture, occurring in 25% of cases in Ibadan is associated with a high mortality. Although its embryogenesis is now better understood, its underlying aetiology remains obscure. Prematurity and low birth weight have no causal relationship to the condition, but a preponderance among the lower socio-economic groups in Ibadan is observed. Thirty-three cases seen over a 5-year period at the University College Hospital, Ibadan, Nigeria, constitute an unusually high incidence, suggesting that the condition may be aetiologically related to umbilical hernia which is known to be commoner in African than in Caucasian infants. Overall treatment results remain unsatisfactory for all types and mortality is still high. In those centres, particularly in the developing countries with scarce resources, conservative management should be the primary treatment modality for all intact sacs but staged procedures utilizing prosthetic materials should be reserved for the large ruptured sac. PMID:7335562

Colonialism, Biko and AIDS: reflections on the principle of beneficence in South African medical ethics.

PubMed

Braude, Hillel David

2009-06-01

This paper examines the principle of beneficence in the light of moral and epistemological concerns that have crystallized in the South African context around clinical care. Three examples from the South African experience affecting the development of bioethics are examined: medical colonialism, the death in detention of Steve Biko, and the HIV/AIDS epidemic. Michael Gelfand's book [(1948). The sick African: a clinical study. Cape Town: Stewart Printing Company.] on African medical conditions captures the ambiguous nature of colonial medicine that linked genuine medical treatment with the civilizing mission. Biko's death was a key historical event that deeply implicated the medical profession under apartheid. The present HIV/AIDS epidemic presents the gravest social and political crisis for South African society. All three experiences influence the meaning and relevance of beneficence as a bioethics principle in the South African context. This paper argues for a South African bioethics informed by a critical humanism that takes account of the colonial past, and that does not model itself on an "original wound" or negation, but on positive care-giving practices.

Emergence of African species of dermatophytes in tinea capitis: A 17-year experience in a Montreal pediatric hospital.

PubMed

Marcoux, Danielle; Dang, Julie; Auguste, Hedwige; McCuaig, Catherine; Powell, Julie; Hatami, Afshin; Maari, Catherine; Le Meur, Jean-Baptiste

2018-05-01

An increase in dermatophyte infections caused by African species is reported in countries receiving African immigrants. Our goal was to determine the epidemiologic and clinical characteristics of tinea capitis in children infected with African species of dermatophytes in Montreal, Canada. Demographic and clinical data from medical records of children infected with African species of dermatophytes were retrieved retrospectively (2000-2016) at Sainte-Justine University Hospital Center. In Montreal, the number of tinea capitis cases caused by African species of dermatophytes increased sixfold over 17 years. African immigrant children (84%), men and boys (61%), and preschoolers (2-5 years old) (51%) were the most frequently affected in our 315 cases. Family contamination was frequent (45%). Referring physicians prescribed systemic antifungal treatment in 39% of cases and pediatric dermatologist consultants in 90%. Treatment failure to oral terbinafine occurred in 39% of Microsporum audouinii infections. In Montreal, there was a significant increase in tinea capitis caused by African species of dermatophytes. Microsporum audouinii is highly transmissible and often resistant to oral terbinafine. Recognizing tinea capitis trends in a given environment will improve patient care. © 2018 Wiley Periodicals, Inc.

PDE-based geophysical modelling using finite elements: examples from 3D resistivity and 2D magnetotellurics

NASA Astrophysics Data System (ADS)

Schaa, R.; Gross, L.; du Plessis, J.

2016-04-01

We present a general finite-element solver, escript, tailored to solve geophysical forward and inverse modeling problems in terms of partial differential equations (PDEs) with suitable boundary conditions. Escript’s abstract interface allows geoscientists to focus on solving the actual problem without being experts in numerical modeling. General-purpose finite element solvers have found wide use especially in engineering fields and find increasing application in the geophysical disciplines as these offer a single interface to tackle different geophysical problems. These solvers are useful for data interpretation and for research, but can also be a useful tool in educational settings. This paper serves as an introduction into PDE-based modeling with escript where we demonstrate in detail how escript is used to solve two different forward modeling problems from applied geophysics (3D DC resistivity and 2D magnetotellurics). Based on these two different cases, other geophysical modeling work can easily be realized. The escript package is implemented as a Python library and allows the solution of coupled, linear or non-linear, time-dependent PDEs. Parallel execution for both shared and distributed memory architectures is supported and can be used without modifications to the scripts.

A Phenomenological Investigation on the Role of Mentoring in the Academic Development of African American Male Secondary Students

NASA Astrophysics Data System (ADS)

Inge, Jillian

The purpose of this phenomenological study was to examine how the construct of mentoring by African American males can support the academic development of African American male students. Since African American male students perform significantly lower in academic subjects than their counterparts of other ethnicities, there is an exigent need for change in this area. Built upon the conceptual framework of communal interactions and identity, the inquiry questioned the experiences of mentors for African American male secondary students, and their perceptions of the influence of a mentoring relationship when the mentor and mentee are of similar backgrounds. Participants in this study were 7 African American males who had mentored or were currently mentoring African American male students. Data, obtained through semi structured interviews and focus group interviews, were coded for themes that reflected the experiences of mentors in mentoring African American males. Mentors in this study reported that students with whom they share similar backgrounds and experiences were better able to relate to them than those who had dissimilar backgrounds and experiences. In addition, mentors reported their mentees were more likely to envision themselves in professional areas beyond their perceived cultural norm when they routinely interact with successful African American males from various fields; thus, it was important for mentors to provide opportunities for students to interact with professionals. Contributions to social change will emerge as African American male mentors understand and employ their roles as a fundamental component in the academic development of African American male secondary students and thus empower this population of students to achieve academic success and to serve in a capacity that nurtures their immediate surroundings.

Talk that talk: storytelling and analysis rooted in African American oral tradition.

PubMed

Banks-Wallace, JoAnne

2002-03-01

Stories are the foundation of qualitative research. However, the development of qualitative methods rooted in oral traditions remains largely unexplored by researchers. The contextual and historical influences on storytelling and storytaking are critical features of the African American oral tradition that are often ignored or minimized in qualitative research. Despite the complex and often contentious history of African Americans, their oral traditions have not been explored to reveal the depth of their lived experiences and the way those experiences inform their health concerns. The purpose of this article is twofold. First, dialogues about storytelling and storytaking are revisited and critiqued. Second, a comprehensive analytic process for gathering and interpreting stories rooted in African American oral tradition is outlined.

Strategies for coping with individual PTSD symptoms: Experiences of African American victims of intimate partner violence.

PubMed

Sullivan, Tami P; Weiss, Nicole H; Price, Carolina; Pugh, Nicole; Hansen, Nathan B

2018-05-01

Understanding how populations at particular risk for posttraumatic stress disorder (PTSD) and its deleterious outcomes cope with individual PTSD symptoms is critical to developing interventions that promote resilience, support recovery, and ultimately empower traumatized populations. Therefore, the purpose of this study was to identify specific strategies women use to cope with individual PTSD symptoms among a population at particular risk for experiencing trauma and its negative sequelae-African American victims of intimate partner violence (IPV) who use substances. This 30-day study included 107 African American women who reported experiencing current IPV and using a substance. During their follow-up interviews, women participated in a structured interview to retrospectively report on the strategies they typically used to cope with various PTSD symptoms during the 30-day period. Results of content analysis revealed that women used 19 different strategies to cope with symptoms (e.g., social support, substance use, electronic media, religious or spiritual coping), which varied as a function of the PTSD symptom experienced. Aggregating symptoms to the cluster level obscured the variability in strategies used to cope with individual symptoms. Findings are discussed in the context of the larger literature on coping and PTSD, specifically regarding (a) coping strategies that may be adaptive or maladaptive and (b) directions for future research that attend to experiences of individual PTSD symptoms. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

African american women, hair care, and health barriers.

PubMed

Gathers, Raechele Cochran; Mahan, Meredith Grace

2014-09-01

The objective of this study was to elucidate the prevalence of hair loss among African American women; explore the psychosocial impact of hair grooming difficulties; and examine both perceptions related to physician encounters in this group and the relationship between hair grooming, physical activity, and weight maintenance. An anonymous retrospective and qualitative survey, the Hair Care Assessment Survey, is an 18-question novel survey instrument designed at the Henry Ford Hospital Department of Dermatology Multicultural Dermatology Center. The Hair Care Assessment Survey was distributed at church-related functions at predominantly African American metropolitan Detroit churches. Two hundred African American women from metropolitan Detroit, Michigan, aged 21 to 83. The Hair Care Assessment Survey collected data relating to hair loss and hair care, psychosocial experiences relating to hair loss, and hair care as it relates to exercise and body weight management. Data was collected on doctor-patient hair-related medical visits and experiences with commercially available ethnic hair care products. More than 50 percent reported excessive hair loss. Twenty-eight percent had visited a physician to discuss hair issues, but only 32 percent felt their physician understood African American hair. Forty-five percent reported avoiding exercise because of hair concerns, and 22 percent felt that their hair impeded maintaining healthy body weight. Hair loss affects a compelling number of African American women, and a significant number express dissatisfaction in hair-related physician encounters. Additionally, hair styling problems present a serious impediment to physical activity and weight management among this already high-risk population.

African American Women, Hair Care, and Health Barriers

PubMed Central

Mahan, Meredith Grace

2014-01-01

Objectives: The objective of this study was to elucidate the prevalence of hair loss among African American women; explore the psychosocial impact of hair grooming difficulties; and examine both perceptions related to physician encounters in this group and the relationship between hair grooming, physical activity, and weight maintenance. Design: An anonymous retrospective and qualitative survey, the Hair Care Assessment Survey, is an 18-question novel survey instrument designed at the Henry Ford Hospital Department of Dermatology Multicultural Dermatology Center. Setting: The Hair Care Assessment Survey was distributed at church-related functions at predominantly African American metropolitan Detroit churches. Participants: Two hundred African American women from metropolitan Detroit, Michigan, aged 21 to 83. Measurements: The Hair Care Assessment Survey collected data relating to hair loss and hair care, psychosocial experiences relating to hair loss, and hair care as it relates to exercise and body weight management. Data was collected on doctor-patient hair-related medical visits and experiences with commercially available ethnic hair care products. Results: More than 50 percent reported excessive hair loss. Twenty-eight percent had visited a physician to discuss hair issues, but only 32 percent felt their physician understood African American hair. Forty-five percent reported avoiding exercise because of hair concerns, and 22 percent felt that their hair impeded maintaining healthy body weight. Conclusion: Hair loss affects a compelling number of African American women, and a significant number express dissatisfaction in hair-related physician encounters. Additionally, hair styling problems present a serious impediment to physical activity and weight management among this already high-risk population. PMID:25276273

Deviant bodies, stigmatized identities, and racist acts: examining the experiences of African-American gamers in Xbox Live

NASA Astrophysics Data System (ADS)

Gray, K. L.

2012-12-01

The purpose of this article is to illustrate how minority gamers, particularly African-American males, are subject to the label of deviant within the virtual gaming community of Xbox Live. They are labeled deviant based on the stigma of their physical identity - blackness, through a process of linguistic profiling. By employing virtual ethnography, the author identifies a process that leads to racism based on how the black gamer sounds within the space. The act of racism emerges through a process involving questioning, provoking, instigating, and ultimately racism. Many black gamers have normalized these racist experiences and have accepted the label of deviant placed upon their bodies.

African American Women and Brown: A Lingering Twilight or Emerging Dawn?

ERIC Educational Resources Information Center

Lindsay, Beverly

1994-01-01

Critically examines the factors continuing to impede the integral presence of African American women in pivotal decision-making positions in colleges and universities. Interviews with three African American women who were among the first deans or associate deans of education at leading schools are presented, detailing their experiences and views…

Career Path Processes as Perceived by African American Female School Principals

ERIC Educational Resources Information Center

Leathers, Sonja

2011-01-01

This study sought to improve our understanding of factors that influence the career paths of African American female school principals in North Carolina. Three pertinent research questions were addressed in this study: (1) What formative experiences influence the career path decisions of African American females who want to become school…

Academic and Career Trajectories of African American Males in San Bernardino

ERIC Educational Resources Information Center

Lyles, Lolita Laree

2013-01-01

A qualitative grounded theory approach is utilized to study the academic and career trajectories of twenty African American male collegiate students living in San Bernardino, California. There is limited research that explores the positive educational experiences of young adult African American males. Therefore, the aim of the present study is to…

Three-Dimensional Magnetotelluric Imaging of the Cascadia Subduction Zone with an Amphibious Array

NASA Astrophysics Data System (ADS)

Egbert, G. D.; Yang, B.; Bedrosian, P.; Kelbert, A.; Key, K.; Livelybrooks, D.; Parris, B. A.; Schultz, A.

2017-12-01

We present results from three-dimensional inversion of an amphibious magnetotelluric (MT) array consisting of 71 offshore and 75 onshore sites in the central part of Cascadia, to image down-dip and along strike variations of electrical conductivity, and to constrain the 3D distribution of fluids and melt in the subduction zone. The array is augmented by EarthScope TA MT data and legacy 2D profiles providing sparser coverage of western WA, OR, and northern CA. The prior model for the inversion includes ocean bathymetry, conductive marine sediments, and a resistive subducting plate, with geometry derived from the model of McCrory et al. (2012) and seismic tomography. Highly conductive features appear just above the interface with the a priori resistive plate in three zones. (1) In the area with marine MT data a conductive layer, which we associate with fluid-rich decollement and subduction channel sediments, extends eastward from the trench to underthrust the seaward edge of Siletzia, which is clearly seen as a thick crustal resistor. The downdip extent of the underthrust conductive layer is a remarkably uniform 35 km. (2) High conductivities, consistent with metamorphic fluids associated with eclogitization, occur near the forearc mantle corner. Conductivity is highly variable along strike, organized in a series of E-W to diagonal elongated conductive/resistive structures, whose significance remains enigmatic. (3) High conductivities associated with fluids and melts are found in the backarc, again exhibiting substantial along strike variability.

Electrical conductivity of the crust in central Baja California, México, based on magnetotelluric observations

NASA Astrophysics Data System (ADS)

Romo, J. M.; Gómez-Treviño, E.; Flores-Luna, C.; García-Abdeslem, J.

2017-12-01

Crustal and sub-crustal structure of northwestern Mexico (peninsular California) resulted from major accretion episodes occurred during the long-lived subduction of the Farallon plate beneath the North American plate, since late Jurassic time. A magnetotelluric profile across central Baja California reveals several electrical conductivity anomalies probably associated to the crustal boundaries of distinct Mezosoic terranes juxtaposed in the current peninsular crust. It is known that electrical conductivity is significantly increased by the pervasive presence of conductive minerals generated during metamorphic processes in highly sheared zones. We interpret a striking sub-horizontal conductivity anomaly reveled in the model as explained by the presence of high-salinity fluids released after dehydration of the subducted Magdalena microplate (Farallon plate?). The presence of fluids at the base of the peninsular crust may produce a zone of weakness, which supports the idea that Baja California lithosphere has not been entirely coupled to the Pacific plate. In addition, crustal thickness is estimated in our model in about 35 km beneath the western Peninsular Ranges batholith (PRB) and 20 km beneath the eastern PRB. This crustal thickness is in good agreement with independent estimations of a thinner crust in the Gulf of California margin and a thicker crust along the axial PRB.

African American Administrators at PWIs: Enablers of and Barriers to Career Success

ERIC Educational Resources Information Center

Gardner, Levester, Jr.; Barrett, T. Gregory; Pearson, L. Carolyn

2014-01-01

Despite literature emphasizing the importance of their presence on college campuses to minority student success, African American administrators are severely underrepresented in higher education. The purpose of this qualitative study was to explore the lived experiences of successful African American student affairs administrators at predominantly…

The Desires of Their Hearts: The Multidisciplinary Perspectives of African Americans on End-of-Life Care in the African American Community.

PubMed

Rhodes, Ramona L; Elwood, Bryan; Lee, Simon C; Tiro, Jasmin A; Halm, Ethan A; Skinner, Celette S

2017-07-01

Studies have identified racial differences in advance care planning and use of hospice for care at the end of life. Multiple reasons for underuse among African American patients and their families have been proposed and deserve further exploration. The goal of this study was to examine perceptions of advance care planning, palliative care, and hospice among a diverse sample of African Americans with varying degrees of personal and professional experience with end-of-life care and use these responses to inform a culturally sensitive intervention to promote awareness of these options. Semistructured interviews and focus groups were conducted with African Americans who had varying degrees of experience and exposure to end-of-life care both personally and professionally. We conducted in-depth qualitative analyses of these interviews and focus group transcripts and determined that thematic saturation had been achieved. Several themes emerged. Participants felt that advance care planning, palliative care, and hospice can be beneficial to African American patients and their families but identified specific barriers to completion of advance directives and hospice enrollment, including lack of knowledge, fear that these measures may hasten death or cause providers to deliver inadequate care, and perceived conflict with patients' faith and religious beliefs. Providers described approaches they use to address these barriers in their practices. Findings, which are consistent with and further elucidate those identified from previous research, will inform design of a culturally sensitive intervention to increase awareness and understanding of advance care planning, palliative care, and hospice among members of the African American community.

The importance of topographic corrections on magnetotelluric response data from rugged regions of Anatolia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guerer, A.; Ilkisik, O.M.

1997-01-01

Topographic irregularities cause some distortions of magnetotelluric (MT) fields. In the vicinity of a topographic feature, the TM-mode distortion increases with the height and inclination of the slope. It is well-known that TM-mode topographic effects are much greater than TE-mode distortions. The authors have made a study of MT anomalies in TM-mode due to two-dimensional topography. In order to reduce these effects, the distortion tensor stripping technique was used. After corrections, the resulting data can be interpreted as if they were obtained over a flat surface and depend only on the subsurface structure. However, this technique sometimes causes some geometricalmore » distortions of the real subsurface structure. One of the aims is to overcome this failure. The authors have modified the correction coefficients by considering the actual one-dimensional geology. Model studies showed that this approach is especially useful in removing the terrain effects on complex 2D subsurface structures. The other purpose of this study is to emphasize the importance of a proper terrain correction for data from sites having mountainous topography over complex geology, e.g., strike-slip faults, suture zones and rift valleys. Some examples of MT data sets collected from the North Anatolian Fault Zone and from the thrust regions of the Western Taurides will be presented.« less

One African Male in Higher Education

ERIC Educational Resources Information Center

Nichols, Robert L.

2016-01-01

Many predominantly White universities and colleges are seeking ways to both recruit and retain Black students (Simmons, J., Lowery-Hart, R., Wahl, S. T., & McBride, M. C. (2013). "Understanding the African-American student experience in higher education through a relational dialectics perspective." "Communication…

The BOrborema Deep Electromagnetic and Seismic (BODES) Experiment

NASA Astrophysics Data System (ADS)

Julià, J.; Garcia, X.; Medeiros, W. E.; Farias do Nascimento, A.

2015-12-01

The Borborema Province of NE Brazil is a large Precambrian domain of the Brazilian shield located in the Northeasternmost corner of South America. It is bounded by the Parnaíba basin to the West and by the São Francisco craton to the South. Its structuration in the Precambrian has been related to compressional processes during the Brasiliano-Pan African orogeny (600-550 Ma). In the Mesozoic, extensional stresses eventually leading to continental breakup, left a number of aborted rift basins within the Province. After continental breakup, the evolution of the Province was marked by episodes of uplift, which might have been coeval with episodes of Cenozoic volcanism. The most prominent expression of those uplift processes is the Borborema Plateau, an elliptically shaped topographic feature in the eastern half of the Province with maximum elevations of ~1200 m. The origin of uplift in the Plateau has been the focus of a number of multi-institutional and multi-disciplinary studies in the past few years, which have imaged the deep structure of the eastern Province with unprecedented detail. The origin of uplift in the western Province, which includes a superb example of basin inversion demonstrated by the ~1000 km elevations of the Chapada do Araripe, however, has been seldom investigated. With the goal of investigating the deep structure of the western Province, a temporary network of 10 collocated seismic and magnetotelluric stations was deployed in the region. The collocated stations were arranged in an approximately NS direction, with an interspation spacing of ~70 km and spanning a total length of ~600 km. The seismic stations consisted of broadband sensors (RefTek 151B-120 "Observer") sampling at 100 Hz and were deployed in January 2015; the MT stations consisted of long-period magnetotelluric (LEMI) systems, sampling at 1 Hz and 4 Hz, and were deployed in April 2015 for a period of ~2 weeks. Preliminary results based on teleseismic P-wave receiver functions

The BOrborema Deep Electromagnetic and Seismic (BODES) Experiment

NASA Astrophysics Data System (ADS)

Nemocon, A. M.; Garcia, X.; Julià, J.

2016-12-01

The Borborema Province of NE Brazil is a large Precambrian domain of the Brazilian shield located in the northeastern most corner of South America. It is bounded by the intracratonic Parnaíba basin to the West and by the mostly Archean São Francisco craton to the South, and its structuration has been related to compressional processes during the Brasiliano-Pan African orogeny (600-550 Ma). In the Mesozoic, extensional stresses related to the opening of the Atlantic ocean left a number of aborted rift basins within the Province. After continental breakup, the evolution of the Province was marked by episodes of uplift, which might have been coeval with episodes of volcanism in the Cenozoic. The most prominent expression of uplift is the Borborema Plateau, an elliptically shaped topographic feature in the eastern Province with maximum elevations of 1200 m. The origin of uplift across the Borborema Plateau has been the focus of a number of multi-disciplinary studies in the past few years, which have imaged the deep structure of the eastern Province with unprecedented detail. The origin of uplift in the western Province, which includes a superb example of basin inversion demonstrated through the 1000 km elevations of the Chapada do Araripe, however, has been seldom investigated. To alleviate this situation, a temporary network of 10 collocated seismic and magnetotelluric stations was deployed in the western Province. The collocated stations were arranged in an approximately NS direction, with an interstation spacing of 70 km and spanning a total length of 600 km. The seismic stations consisted of broadband sensors sampling at 100 Hz and were deployed in January 2015; the MT stations consisted of long-period magnetotelluric systems, sampling at 1 Hz and 4 Hz, and were deployed in April 2015 for a period of 2 weeks. Preliminary results based on P-receiver functions suggest that the crust thickens gradually to the South, from 36 km in the northern end of the profile to

Race Differences in the Association of Spiritual Experiences and Life Satisfaction in Older Age

PubMed Central

Skarupski, Kimberly A.; Fitchett, George; Evans, Denis A.; de Leon, Carlos F. Mendes

2013-01-01

Objectives The primary objective of this study was to examine an African American ‘faith advantage’ in life satisfaction. Specifically, we sought to test the hypothesis that the positive relationship between spiritual experiences and life satisfaction is stronger among older African Americans than among older Whites. Method The data came from 6,864 community-dwelling persons aged 65+ (66% African American) who participated in the Chicago Health and Aging Project. Life satisfaction was measured using a five-item composite and we used a five-item version of the Daily Spiritual Experiences scale. Results In a regression model adjusting for age, sex, marital status, education, income, and worship attendance, we found that African American race was associated with lower life satisfaction. We also found a positive association between spiritual experiences and life satisfaction. In an additional model, a significant race × spiritual experiences interaction term indicates that spiritual experiences are more positively associated with life satisfaction among African Americans. Conclusion The data suggest that at higher levels of spiritual experiences, racial differences in life satisfaction are virtually non-existent. However, at lower levels of spiritual experiences, older African Americans show modestly lower levels of life satisfaction than do older Whites. This pattern suggests that spiritual experiences are a positive resource - distinct from worship attendance- that enable older African Americans to overcome decrements in life satisfaction and in fact, that lower spiritual experiences may be especially harmful for older African American’s life satisfaction. PMID:23627686

Barriers to treatment and culturally endorsed coping strategies among depressed African-American older adults

PubMed Central

Conner, Kyaien O.; Copeland, Valire Carr; Grote, Nancy K.; Rosen, Daniel; Albert, Steve; McMurray, Michelle L.; Reynolds, Charles F.; Brown, Charlotte; Koeske, Gary

2011-01-01

Objective Older adults are particularly vulnerable to the effects of depression, however, they are less likely to seek and engage in mental health treatment. African-American older adults are even less likely than their White counterparts to seek and engage in mental health treatment. This qualitative study examined the experience of being depressed among African-American elders and their perceptions of barriers confronted when contemplating seeking mental health services. In addition, we examined how coping strategies are utilized by African-American elders who choose not to seek professional mental health services. Method A total of 37 interviews were conducted with African-American elders endorsing at least mild symptoms of depression. Interviews were audiotaped and subsequently transcribed. Content analysis was utilized to analyze the qualitative data. Results Thematic analysis of the interviews with African-American older adults is presented within three areas: (1) Beliefs about Depression Among Older African-Americans: (2) Barriers to Seeking Treatment for Older African-Americans: and (3) Cultural Coping Strategies for Depressed African-American Older Adults. Conclusion Older African-Americans in this study identified a number of experiences living in the Black community that impacted their treatment seeking attitudes and behaviors. which led to identification and utilization of more culturally endorsed coping strategies to deal with their depression. Findings from this study provide a greater understanding of the stigma associated with having a mental illness and its influence on attitudes toward mental health services. PMID:21069603

Engendering Subjectivities: Narratives of African Immigrant Girls in Public High Schools

ERIC Educational Resources Information Center

Okwako, Betty Akinyi

2011-01-01

The goal of this study was to illuminate the educational experiences of one of the least researched immigrant groups--African girls. I relied mainly on narratives of four African immigrant girls in public high schools to elucidate how these girls defined their learning environment. Out of school observations were used to supplement in-depth…

In Their Own Words: Stories from HIV-Positive African American Women

ERIC Educational Resources Information Center

Robillard, Alyssa G; Reed, Cymone; Larkey, Linda; Kohler, Connie; Ingram, Lucy A; Lewis, Kaleea; Julious, Carmen

2017-01-01

Objectives: African American women are disproportionately impacted upon by HIV, particularly in the Southern states of the USA where the percentage of new cases of HIV and the percentage of people living with HIV in the USA are highest. This study describes the lived experiences of HIV-positive African American women based on their written…

Involvement of African-American Girls in Science, Technology, Engineering, and Mathematics (STEM) Education

NASA Astrophysics Data System (ADS)

Nkere, Nsidi

A qualitative case study was conducted by examining the perceptions of fifth-grade African American girls about their experiences with science, technology, engineering and mathematics (STEM) education and potential for STEM as a future career. As the United States suffers from waning participation across all demographics in STEM and a high level of underrepresentation of African American women in STEM, the proposed study examined data collected through open-ended interviews with fifth-grade African American girls to explore how their current experiences and perceptions might relate to the underrepresentation of African American women in the STEM fields. Participants were selected from Miracle Elementary School (pseudonym), and consisted of all five students in a small class of high-achieving fifth-grade girls. Data were collected through in-class observations and open-ended interviews, and were analyzed using computer content analysis. The most important key results threaded through the data were related to the importance and role of the teacher, the importance of math to students, the role of experimentation and discovery, and hands-on and personal experience. Future studies are encouraged to utilize longitudinal design to follow students from elementary to university level in an effort to develop and understand the perception, persistence, and experience of all girls in STEM programs.

Linking numerical models of lithospheric deformation and magnetotelluric images

NASA Astrophysics Data System (ADS)

Sobolev, S. V.

2012-12-01

Efficient modeling of geodynamic processes requires constraints from different fields of geosciences. Frequently used are data on crustal structure and composition and their evolution constrained by seismic, gravity and petrological/geochemical studies. However, links between geodynamic modeling and rapidly developing field of magnetotelluric (MT) studies are still insufficient. I'll consider two recent examples of MT observations and geodynamic modeling demonstrating that joint analyses of thermomechanical models of lithospheric deformation and MT images may be useful to understand geodynamic processes. One set of observations is MT data for San Andreas Fault (SAF) in the region close to the SAFOD Site (Becken et al., 2011) that shows high conductivity anomalies in the mantle, that are interpreted as fluid flow feeding creeping part of SAF south of the SAFOD Site. Interestingly, zones of high conductivity do not coincide with the expected zones of the recent active deformation (SAF), but are located to the west of it. Based on thermomechanical model of the evolution of the SAFS in Central and Northern California during the last 20 Mln. years (Popov et al., 2012), I'll demonstrate that high conductivity anomalies precisely coincide with the expected zones of the highest accumulated shear strain. Possible interpretation of this coincidence is that strong preferred orientation of olivine crystals in the highly deformed mantle shear zone causes high permeability of fluids. Another set of observations is MT data showing high conductivity anomalies in the crust of Tibet (Unsworh et al., 2005, Bai et al., 2010) and Pamirs (Sass et al., 2011) that are often interpreted as an evidence for the widely spread partially molten crust. Using 2D thermomechanical models of the collision between India and Eurasia, I'll demonstrate that such structures in the crust cannot appear without delamination of the mantle lithosphere during tectonic shortening. Internal heating of the

Magnetotelluric studies of the Caldas Novas geothermal reservoir, Brazil

NASA Astrophysics Data System (ADS)

de Lugão, Patricia Pastana; LaTerra, Emanuele Francesco; Kriegshäuser, Berthold; Fontes, Sergio L.

2002-01-01

A magnetotelluric (MT) survey was conducted on the Caldas Novas geothermal reservoir located in the state of Goiás, Central Brazil. The region of Caldas Novas is a popular tourist spot because of the occurrence of hot water springs. The purpose of the first MT survey in this area is to provide more information on the geoelectrical structure of this important geothermal reservoir. The MT method is a frequency domain technique that utilizes naturally occurring magnetic and electric signals as source to obtain a resistivity map of the subsurface. Since temperature and permeability are some of the factors controlling electrical resistivity, MT is widely utilized for surveying geothermal areas such as Caldas Novas. Data were acquired along two profiles crossing the Serra de Caldas (Caldas Mountains) with a total of 25 MT stations. Frequencies of acquisition were in the range from 0.008 to 176 Hz. Spacing between stations were usually around 5 km. Apparent resistivity and phase data from the transverse electric (TE) and transverse magnetic (TM) modes were computed for both profiles. Very high (100,000 Ω m) apparent resistivity values in the TM mode indicate distortion, possibly caused by 3-D resistive structures. In this work, we focus on Profile 2, which was acquired aligned at N40°E, approximately following the direction of weakness N50°E. Two-dimensional (2-D) inversion suggests a basin-like model with very high-resistivity block structures associated with concentric faulting below the Caldas Mountains inside a resistive basin that extends to depths of approximately 25-30 km. This model is in good agreement with gravity data and the available geological information in the area and can help delineate areas of new geothermal reservoirs. The high resistivity associated with the depression in the MT model can be interpreted as caused by the low-permeability quartzites that form the Caldas Mountains. Although the survey configuration does not allow for a full three

African Ancestry Is Associated with Asthma Risk in African Americans

PubMed Central

Pino-Yanes, María; Wade, Michael S.; Pérez-Méndez, Lina; Kittles, Rick A.; Wang, Deli; Papaiahgari, Srinivas; Ford, Jean G.; Kumar, Rajesh; Garcia, Joe G. N.

2012-01-01

Background Asthma is a common complex condition with clear racial and ethnic differences in both prevalence and severity. Asthma consultation rates, mortality, and severe symptoms are greatly increased in African descent populations of developed countries. African ancestry has been associated with asthma, total serum IgE and lower pulmonary function in African-admixed populations. To replicate previous findings, here we aimed to examine whether African ancestry was associated with asthma susceptibility in African Americans. In addition, we examined for the first time whether African ancestry was associated with asthma exacerbations. Methodology/Principal Findings After filtering for self-reported ancestry and genotype data quality, samples from 1,117 self-reported African-American individuals from New York and Baltimore (394 cases, 481 controls), and Chicago (321 cases followed for asthma exacerbations) were analyzed. Genetic ancestry was estimated based on ancestry informative markers (AIMs) selected for being highly divergent among European and West African populations (95 AIMs for New York and Baltimore, and 66 independent AIMs for Chicago). Among case-control samples, the mean African ancestry was significantly higher in asthmatics than in non-asthmatics (82.0±14.0% vs. 77.8±18.1%, mean difference 4.2% [95% confidence interval (CI):2.0–6.4], p<0.0001). This association remained significant after adjusting for potential confounders (odds ratio: 4.55, 95% CI: 1.69–12.29, p = 0.003). African ancestry failed to show an association with asthma exacerbations (p = 0.965) using a model based on longitudinal data of the number of exacerbations followed over 1.5 years. Conclusions/Significance These data replicate previous findings indicating that African ancestry constitutes a risk factor for asthma and suggest that elevated asthma rates in African Americans can be partially attributed to African genetic ancestry. PMID:22235241

Masculinity and the Body: How African-American and White Men Experience Cancer Screening Exams Involving the Rectum

PubMed Central

Winterich, Julie A.; Quandt, Sara A; Grzywacz, Joseph G.; Clark, Peter E.; Miller, David P.; Acuña, Joshua; Arcury, Thomas A.

2008-01-01

Past research on prostate and colorectal cancer disparities finds that barriers to screening, such as embarrassment and offensiveness, are often reported. Yet none of this literature investigates why. This study uses masculinity and health theory to examine how men experience two common screenings, digital rectal exams (DREs) and colonoscopies. In-depth interviews were conducted with 64 African-American and white men from diverse backgrounds, aged 40–64, from North Carolina, USA. Regardless of race or education, men experienced DREs more negatively than colonoscopies because penetration with a finger was associated with a gay sexual act. Some men disliked colonoscopies, however, because they associated any penetration as an affront to their masculinity. Because beliefs did not differ by race, future research should focus on structural issues to examine why disparities persist with prostate and colorectal cancer. Recommendations are provided for educational programs and physicians to improve men’s experiences with exams that involve the rectum. PMID:19477742

Masculinity and the body: how African American and White men experience cancer screening exams involving the rectum.

PubMed

Winterich, Julie A; Quandt, Sara A; Grzywacz, Joseph G; Clark, Peter E; Miller, David P; Acuña, Joshua; Arcury, Thomas A

2009-12-01

Past research on prostate and colorectal cancer disparities finds that barriers to screening, such as embarrassment and offensiveness, are often reported. Yet none of this literature investigates why. This study uses masculinity and health theory to examine how men experience two common screenings: digital rectal exams (DREs) and colonoscopies. In-depth interviews were conducted with 64 African American and White men from diverse backgrounds, aged 40 to 64, from North Carolina. Regardless of race or education, men experienced DREs more negatively than colonoscopies because penetration with a finger was associated with a gay sexual act. Some men disliked colonoscopies, however, because they associated any penetration as an affront to their masculinity. Because beliefs did not differ by race, future research should focus on structural issues to examine why disparities persist with prostate and colorectal cancer. Recommendations are provided for educational programs and physicians to improve men's experiences with exams that involve the rectum.

Recruitment and retention of rural African Americans in diabetes research: lessons learned.

PubMed

Loftin, Wanda Anderson; Barnett, Steven K; Bunn, Peggy Summers; Sullivan, Patra

2005-01-01

The purpose of this article was to describe lessons learned about recruitment and retention of rural African Americans from published literature, the authors' research, and research experience. Two rural, community-based research studies with African Americans with diabetes are used to illustrate different issues and strategies in recruitment and retention. Relevant MEDLINE articles and clinical studies were reviewed, and the design, implementation, and results of the 2 community-based studies were evaluated. Information from the literature, research results, and sample selection, participation, and attrition experiences were synthesized to determine effective approaches for recruitment and retention. Research funding, design, and implementation; recruitment methods; culturally competent approaches; caring, trusting provider-patient relationships; incentives; follow-up; and factors in the rural environment emerged as important issues influencing recruitment and retention. Recruitment and retention of African Americans in rural diabetes research is a significant challenge, and adequate funding should be sought early in the research process. Culturally competent approaches; caring, trusting relationships; incentives; and follow-up are important concepts in successful recruitment, participation, and retention of African Americans. The lessons learned may be applicable to the more widespread issue of recruitment and retention of rural African Americans in diabetes education programs.

Magnetotellurics applied to the study of the Guaraní aquifer in Entre Ríos Province, N-E Argentina

NASA Astrophysics Data System (ADS)

Favetto, Alicia; Curcio, Ana; Pomposiello, Cristina

2011-07-01

The South American Guaraní Aquifer System covers the entire Parana basin and part of the Chaco-Parana basin. This system is one of the most important groundwater reservoirs; it is shared by four neighboring countries covering an area larger than one million square kilometers. The geological units closely related to the Guaraní Aquifer are the Piramboia and Botucatu Formations that consist of Triassic-Jurassic aeolian, fluvial and lacustrine sandstones, and the Serra Geral basalts with clastic intercalations. Serra Geral, an effusive Cretaceous complex, covers the sandstones and provides a high degree of confinement to the system. This paper presents the interpretation of magnetotelluric (MT) data collected during 2007-2008 in Entre Ríos Province, Argentina. These data, recorded in three profiles, mainly provide the depth to the crystalline basement, determinant for the presence of aquifer-related sediments. Models showed that the discrimination of the basalts strongly depends on local electrical characteristics. Model information is quite consistent with the information from oil and thermal wells located close to the profiles.

Accounting for the Effect of Earth's Rotation in Magnetotelluric Inference

NASA Astrophysics Data System (ADS)

Riegert, D. L.; Thomson, D. J.

2017-12-01

The study of geomagnetism has been documented as far back as 1722 when the watchmaker G. Graham constructed a more sensitive compass and showed that the variations in geomagnetic direction varied with an irregular daily pattern. Increased interest in geomagnetism in geomagnetism began at the end of the 19th century (Lamb, Schuster, Chapman, and Price). The Magnetotelluric Method was first introduced in the 1950's (Cagniard and Tikhonov), and, at its core, is simply a regression problem. The result of this method is a transfer function estimate which describes the earth's response to magnetic field variations. This estimate can then be used to infer the earth's subsurface structure; useful for applications such as natural resource exploration. The statistical problem of estimating a transfer function between geomagnetic and induced current measurements has evolved since the 1950's due to a variety of problems: non-stationarity, outliers, and violation of Gaussian assumptions. To address some of these issues, robust regression methods (Chave and Thomson, 2004) and the remote reference method (Gambel, 1979) have been proposed and used. The current method seems to provide reasonable estimates, but still requires a large amount of data. Using the multitaper method of spectral analysis (Thomson, 1982), taking long (greater than 4 months) blocks of geomagnetic data, and concentrating on frequencies below 1000 microhertz to avoid ultraviolet effects, one finds that:1) the cross-spectra are dominated by many offset frequencies including plus and minus 1 and 2 cycles per day;2) the coherence at these offset frequencies is often stronger than at zero offset;3) there are strong couplings from the "quasi two-day" cycle;4) frequencines are usually not symmetric;5) the spectra are dominated by the normal modes of the Sun. This talk will discuss the method of incorporating these observations into the transfer function estimation model, some of the difficulties that arose, their

African American women making race work in science, technology, engineering, and math (STEM)

NASA Astrophysics Data System (ADS)

Galloway, Stephanie Nicole

African American women maintain distinctive social locations at the intersection of race, gender, and class (Crenshaw, 1991; Collins, 1986; 2000; Wing, 2003). However, their voices, interpretation of experiences, and concern with the use of formal education as a mechanism for racial uplift have not been priorities in feminist movements (hooks, 1981; 1989; Perkins, 1993; Smith, 1998; Spitzack & Carter, 1987). Alternatively, Black feminist thought (Collins, 1990; 2000) is a theory constructed by and for African American women. Given the consequences of pursuing formal education in the histories of African American women and the paucity of African American women represented in STEM fields, the purpose of this study was to (a) reveal how African American women conducting research in STEM disciplines accomplished their professional goals, (b) learn how the women negotiated their multiple identities (i.e. race, gender, and class), (c) link the history of educational experiences among African Americans with agendas for social justice, (d) understand how African American women in STEM align their personal accomplishments with broader agendas for activism in higher education, and (e) discover whether there is a collective identity that successful African American women in STEM share. Using Black feminist thought (Collins, 1986; 2000) and narrative analysis of semi- interviews with eight African American women in STEM, the findings from this study revealed: (a) the women in this study described the challenges of pursuing a career in STEM from a feminist perspective, identifying gender as more significant than race; (b) the women in this study experienced more positive interactions with Black male, White female, and White male mentors than with Black female mentors; (c) the women in this study described the use of empowering strategies for overcoming obstacles in their academic pathways; and (d) their collective academic identities were formed by early interactions with

Contextual Influences on Gendered Racial Identity Development of African American Young Women

ERIC Educational Resources Information Center

Thomas, Anita Jones; Hoxha, Denada; Hacker, Jason Daniel

2013-01-01

The aim of the study was to identify the contextual factors and socialization experiences most salient to the identity development of African American girls. Seventeen African American young women participated in dyadic focus groups. Themes that emerged included exposure to stereotypes, negative classroom environments, and parental and peer…

African American Social Work Faculty: Overcoming Existing Barriers and Achieving Research Productivity

ERIC Educational Resources Information Center

Allen, Junior Lloyd; Huggins-Hoyt, Kimberly Y.; Holosko, Michael J.; Briggs, Harold E.

2018-01-01

Purpose: This study explored the scholarship experiences of top-ranked African American faculty in schools of social work. Method: Qualitative interviews were conducted with N = 10 top-ranked African American faculty identified as achieving considerable productivity and impact of scholarship. Findings: Four major themes were identified, each of…

African American Male Superintendents in Urban School Districts: National Stories of Success

ERIC Educational Resources Information Center

Carrier, Isaac Charles

2017-01-01

The purpose of this study is to examine and interpret the life experiences and leadership practices of four African American male superintendents leading urban school districts across the nation. The research approach adopted in this dissertation used semi-structured interviews with four African American male superintendents that consisted of…

Pre-experience perceptions about telemedicine among African Americans and Latinos in South Central Los Angeles.

PubMed

George, Sheba M; Hamilton, Alison; Baker, Richard

2009-01-01

This study explores perceptions about telemedicine among urban underserved African American and Latino populations. Telemedicine has been advanced as a vehicle to increase access to specialty care among the urban underserved, yet little is known about its acceptability among these populations. We conducted 10 focus groups with African American and Latino participants (n = 87) in urban Los Angeles in order to explore perceptions about this novel type of care. We found that concerns about telemedicine varied between the two racial/ethnic groups. These findings have implications for important issues such as adoption of telemedicine, patient satisfaction, and doctor-patient interaction. It will be critical to consider perceptions of this healthcare innovation in the development of strategies to market and implement telemedicine among urban, underserved African American and Latino populations.

Cancer Support Needs for African American Breast Cancer Survivors and Caregivers.

PubMed

Haynes-Maslow, Lindsey; Allicock, Marlyn; Johnson, La-Shell

2016-03-01

Improved cancer screening and treatment advances have led to higher cancer survival rates in the United States. However, racial disparities in breast cancer survival persist for African American women who experience lower survival rates than white women. These disparities suggest that unmet needs related to survivorship still exist. This study focuses on the challenges that both African American cancer survivors and caregivers face across the cancer continuum. Five African American focus groups examined cancer survivor and caregiver support needs. Focus groups were recorded, transcribed, and uploaded into Atlas.ti. Thematic content analysis was applied to the text during the coding process. Themes were identified and emphasized based on the research team's integrated and unified final codes. Forty-one African Americans participated in five focus groups: 22 cancer survivors and 19 caregivers. Participants discussed five themes: (1) a culture that discourages the discussion of cancer; (2) lack of support services for African American cancer survivors; (3) lack of support services for cancer caregivers; (4) need for culturally appropriate cancer resources, including resources targeted at African American women; and (5) aspects that were helpful to cancer survivors and caregivers, including connecting with other survivors and caregivers, and having strong social support networks. We gained new insight into the unmet support needs for survivors and caregivers, especially when coping with the cancer experience continuum. While some cancer and caregiver support services exist, our study reveals a great need for services that incorporate the cultural differences that exist across races.

Factors in African Americans Pursuing Higher Education after Age 30 Years

ERIC Educational Resources Information Center

Henderson, Davetta A.

2011-01-01

Many African Americans are leaving high school prior to graduation and are entering college for the first time beyond the age of 30 years, a phenomenon that has an effect on school systems, the community, and society as a whole. The research problem addressed was the need to understand the experience of an increasing number of African Americans…

Age and HIV Risk and Protective Behaviors among African American Women

ERIC Educational Resources Information Center

Corneille, Maya A.; Zyzniewski, Linda E.; Belgrave, Faye Z.

2008-01-01

Though HIV prevention efforts have focused on young adult women, women of all ages may engage in HIV risk behaviors and experience barriers to condom use. This article examines the effect of age on sexual risk and protective attitudes and behaviors among African American women. Unmarried heterosexual African American women between the ages of 18…

African and Afro-Caribbean men's experiences of prostate cancer.

PubMed

Anderson, Beverley; Marshall-Lucette, Sylvie

It is well documented that prostate cancer presents a significant health problem for middle-aged and elderly men in the UK, with further evidence suggesting that the disease is more prevalent in men of African and Afro-Caribbean (AAC) ethnicity. There is also evidence that these men are diagnosed much later and that the disease is more aggressive than in Caucasian men. To explore AAC men's experiences of prostate cancer and their understanding of its associated risks. The purpose was to gain an insight from these men's perspectives and ascertain whether a more focused health promotion strategy, and specific UK-based research, was needed in this area. A purposive sample of seven AAC men was recruited from a hospital trust's patient list after gaining approval from a research ethics committee. In-depth face-to-face interviews were carried out and the transcripts analysed thematically. The four main themes that emerged were: disease-prompted awareness, checking up as a necessary evil, defining and constructing factors influencing prostate cancer screening uptake, and appraising perceived myths about prostate cancer through personal beliefs. Among this group of AAC men, socioeconomic status, such as education and professional background, were factors that influenced their level of awareness of prostate cancer and prompted their decisions to seek help. However, it is evident from these men's perspectives that a more specific health education strategy that promotes early detection and management, targeting AAC men, would help in demystifying prostate cancer and encourage them to seek help earlier. Further research studies and health education in prominent social outlets are recommended in increasing AAC men's awareness of prostate cancer and its associated risks.

Self-care and mothering in African American women with HIV/AIDS.

PubMed

Shambley-Ebron, Donna Z; Boyle, Joyceen S

2006-02-01

African American women are the most rapidly growing group of people in the United States diagnosed with HIV/AIDS. The purpose of this study was to explore experiences of self-care and mothering among African American women with HIV/AIDS. It is important to recognize how culture affects illness management, childrearing, and daily living to design culturally appropriate nursing interventions for African American women. Critical ethnography was used to study 10 African American mothers from the rural Southeast who were HIV positive and mothered children who were HIV positive. Domains derived from the research were disabling relationships, strong mothering, and redefining self-care. The cultural theme was creating a life of meaning. African American mothers with HIV/AIDS in the rural Southeast used culturally specific self-care and mothering strategies reflective of cultural traditions. This study acknowledges strengths of African American women and generates theory that will enhance nursing care to this population.

How African-American Elementary Students in High-Poverty Schools Experience Creative Expression: A Case Study Approach

ERIC Educational Resources Information Center

Willis, Belinda F.

2016-01-01

Literature that addresses how the arts enhance student learning through creative expression is minimal. This is especially true for African-American elementary students from high-poverty backgrounds. The purpose of this study was to employ a case study design to explore how African-American elementary students in high-poverty schools experience…

The effect of perceived racial discrimination on bodily pain among older African American men.

PubMed

Burgess, Diana J; Grill, Joseph; Noorbaloochi, Siamak; Griffin, Joan M; Ricards, Jennifer; van Ryn, Michelle; Partin, Melissa R

2009-11-01

We examined the extent to which experiences of racial discrimination are associated with bodily pain reported by African American men. The study sample consisted of 393 African American male veterans who responded to a national survey of patients aged 50-75 who received care from the Veterans Health Administration (VHA). Veterans were surveyed by mail, with a telephone follow-up. The response rate for African Americans in the sample was 60.5%. Pain (assessed using the bodily pain subscale of the 36-item short-form health survey), experiences of discrimination, employment, education, and income were obtained through the survey. Age, race, and mental health comorbidities were obtained from VA administrative data. Multiple regression analysis adjusting for item non-response (via imputation) and unit non-response (via propensity scores and weighting) was used to assess the association between racial discrimination and likelihood of experiencing moderate or severe pain over the past 4 weeks. Experiences of racial discrimination were associated with greater bodily pain (beta = -0.25, P < 0.0001), even after controlling for socioeconomic and health-related characteristics. Perceived racial discrimination was associated with greater pain among a sample of older African American male patients in the VA. Additional research is needed to replicate this finding among other populations of African Americans.

Resistivity characterisation of Hakone volcano, Central Japan, by three-dimensional magnetotelluric inversion

NASA Astrophysics Data System (ADS)

Yoshimura, Ryokei; Ogawa, Yasuo; Yukutake, Yohei; Kanda, Wataru; Komori, Shogo; Hase, Hideaki; Goto, Tada-nori; Honda, Ryou; Harada, Masatake; Yamazaki, Tomoya; Kamo, Masato; Kawasaki, Shingo; Higa, Tetsuya; Suzuki, Takeshi; Yasuda, Yojiro; Tani, Masanori; Usui, Yoshiya

2018-04-01

On 29 June 2015, a small phreatic eruption occurred at Hakone volcano, Central Japan, forming several vents in the Owakudani geothermal area on the northern slope of the central cones. Intense earthquake swarm activity and geodetic signals corresponding to the 2015 eruption were also observed within the Hakone caldera. To complement these observations and to characterise the shallow resistivity structure of Hakone caldera, we carried out a three-dimensional inversion of magnetotelluric measurement data acquired at 64 sites across the region. We utilised an unstructured tetrahedral mesh for the inversion code of the edge-based finite element method to account for the steep topography of the region during the inversion process. The main features of the best-fit three-dimensional model are a bell-shaped conductor, the bottom of which shows good agreement with the upper limit of seismicity, beneath the central cones and the Owakudani geothermal area, and several buried bowl-shaped conductive zones beneath the Gora and Kojiri areas. We infer that the main bell-shaped conductor represents a hydrothermally altered zone that acts as a cap or seal to resist the upwelling of volcanic fluids. Enhanced volcanic activity may cause volcanic fluids to pass through the resistive body surrounded by the altered zone and thus promote brittle failure within the resistive body. The overlapping locations of the bowl-shaped conductors, the buried caldera structures and the presence of sodium-chloride-rich hot springs indicate that the conductors represent porous media saturated by high-salinity hot spring waters. The linear clusters of earthquake swarms beneath the Kojiri area may indicate several weak zones that formed due to these structural contrasts.[Figure not available: see fulltext.

Joint inversion of teleseismic receiver functions and magnetotelluric data using a genetic algorithm: Are seismic velocities and electrical conductivities compatible?

NASA Astrophysics Data System (ADS)

Moorkamp, M.; Jones, A. G.; Eaton, D. W.

2007-08-01

Joint inversion of different kinds of geophysical data has the potential to improve model resolution, under the assumption that the different observations are sensitive to the same subsurface features. Here, we examine the compatibility of P-wave teleseismic receiver functions and long-period magnetotelluric (MT) observations, using joint inversion, to infer one-dimensional lithospheric structure. We apply a genetic algorithm to invert teleseismic and MT data from the Slave craton; a region where previous independent analyses of these data have indicated correlated layering of the lithosphere. Examination of model resolution and parameter trade-off suggests that the main features of this area, the Moho, Central Slave Mantle Conductor and the Lithosphere-Asthenosphere boundary, are sensed to varying degrees by both methods. Thus, joint inversion of these two complementary data sets can be used to construct improved models of the lithosphere. Further studies will be needed to assess whether the approach can be applied globally.

Application of telluric-telluric profiling combined with magnetotelluric and self-potential methods to geothermal exploration in the Fujian Province, China

NASA Astrophysics Data System (ADS)

Pham, Van-Ngoc; Boyer, Danièle; Yuan, Xue Cheng; Liu, Shao Cheng

1995-05-01

In the Fujian Province, southeastern China, most of the hot springs emerge in fluviatile valleys and the geothermal resources are mainly medium and low temperature ones by mixing of hot water with cold superficial groundwater. The occurrence of the thermal waters is controlled by deep tectonic fractures in the bedrock where higher-temperature geothermal reservoirs of economic interest are present. The objective of this study is to detect the deeper active hydrothermal zone under a thick sedimentary cover by geoelectrical methods. In the Gui-An site, the combination of telluric-telluric profiling and magnetotelluric methods turns out very efficient to delineate more accurately the width of the deep conductive fracture zone. Moreover, the self-potential method allows us to localize the most active geothermal zone by electrofiltration processes above a convective cell of hot water which flows up from a deep source. The combined results constitute a possible guide for deep geothermal exploration currently encountered in several geothermal regions over the world.

Numerical Simulation of Response Characteristics of Audio-magnetotelluric for Gas Hydrate in the Qilian Mountain Permafrost, China

NASA Astrophysics Data System (ADS)

Xiao, Kun; Zou, Changchun; Yu, Changqing; Pi, Jinyun

2015-10-01

Audio-magnetotelluric (AMT) method is a kind of frequency-domain sounding technique, which can be applied to gas hydrate prospecting and assessments in the permafrost region due to its high frequency band. Based on the geological conditions of gas hydrate reservoir in the Qilian Mountain permafrost, by establishing high-resistance abnormal model for gas hydrate and carrying out numerical simulation using finite element method (FEM) and nonlinear conjugate gradient (NLCG) method, this paper analyzed the application range of AMT method and the best acquisition parameters setting scheme. When porosity of gas hydrate reservoir is less than 5%, gas hydrate saturation is greater than 70%, occurrence scale is less than 50 m, or bury depth is greater than 500 m, AMT technique cannot identify and delineate the favorable gas hydrate reservoir. Survey line should be more than twice the length of probable occurrence scale, while tripling the length will make the best result. The number of stations should be no less than 6, and 11 stations are optimal. At the high frequency section (10˜1000 Hz), there should be no less than 3 frequency points, 4 being the best number.

A large hydrothermal reservoir beneath Taal Volcano (Philippines) revealed by magnetotelluric resistivity survey: 2D resistivity modeling

NASA Astrophysics Data System (ADS)

Yamaya, Y.; Alanis, P. K. B.; Takeuchi, A.; Cordon, J. M.; Mogi, T.; Hashimoto, T.; Sasai, Y.; Nagao, T.

2013-07-01

Taal Volcano, located in the southwestern part of Luzon Island, Philippines, has frequently experienced catastrophic eruptions from both the Main Crater on Volcano Island and flank eruptions. These eruptions have been magmatic, phreatomagmatic, and hydrothermal, with the latter implying the existence of a large-scale hydrothermal system beneath the volcano. We conducted an electrical resistivity survey using the magnetotelluric method in order to identify the location and geometry of the hydrothermal reservoir and sealing cap rock. Two-dimensional inversion using the observed data indicates four similar resistivity sections. The structure at shallow depths corresponds to volcanic deposits and an aquifer. Below 1 km, the structure features a relatively resistive zone beneath the main crater surrounded by a conductive shell. We interpreted these to be a large hydrothermal reservoir with an impermeable cap rock sealing it. Recent ground deformation detected by GPS measurements suggests that the hydrothermal reservoir is active. The interpreted cap rock thins just beneath the main crater and could easily be destroyed by an imbalance in the hydrothermal system. We conclude that this hydrothermal reservoir plays a significant role in driving catastrophic eruptions that begin with a hydrothermal explosion at the main crater.

African American males diagnosed with schizophrenia: a phenomenological study.

PubMed

Anderson, Lorraine Ballard

2014-08-01

Little is known about how African American men with schizophrenia experience their every day existence. Through applying interpretive phenomenology and using a methodological structure designed by van Manen (1990, 1997), this research aimed to enrich the current understanding of what it is like for these African American males to live with schizophrenia. In this study, five men ranging in age from 21 to 57 described their lives within the context of existing with the diagnosis of schizophrenia. The lived experiences across the interviews revealed four overarching themes: They know that they are mentally ill; they make a special effort to test reality; they assert their autonomy and; they experience reality differently, which they see as a gift. To provide appropriate treatment support to African American males diagnosed with schizophrenia, it is important to recognize the clients' ability to assert their autonomy and appreciate each man's view of himself as unique and special. Moreover, in terms of symptom management, it is pivotal to understand that although the client may not be free of hallucinations and delusions, he nevertheless may be at his optimum state of wellness. The realization that these men have transcended their diagnosis of schizophrenia rather than being crushed by their condition is evident in their stories.

Perspectives of Female African American Superintendents

ERIC Educational Resources Information Center

Bush, Rhea R.

2016-01-01

Gender, race, and class--intertwining oppressions experienced by Black women have ultimately led to barriers such as marginality, exploitation, political subjugation, and negative images of African American women (Collins, 2009). Research about the lived experiences of Black women has either been infrequently told or narrated by individuals who…

Perceived Racial/Ethnic Harassment and Tobacco Use Among African American Young Adults

PubMed Central

Bennett, Gary G.; Wolin, Kathleen Yaus; Robinson, Elwood L.; Fowler, Sherrye; Edwards, Christopher L.

2005-01-01

We examined the association between perceived racial/ethnic harassment and tobacco use in 2129 African American college students in North Carolina. Age-adjusted and multivariate analyses evaluated the effect of harassment on daily and less-than-daily tobacco use. Harassed participants were twice as likely to use tobacco daily (odds ratio = 2.01; 95% confidence interval=1.94, 2.08) compared with those with no reported harassment experiences. Experiences of racial/ethnic harassment may contribute to tobacco use behaviors among some African American young adults. PMID:15671457

Making String Education Culturally Responsive: The Musical Lives of African American Children