Spatial and Temporal Variability in Surficial Seabed Character, Waipaoa River Margin, New Zealand

The Waipaoa River margin, located off the northeast coast of the North Island of New Zealand, provides an opportunity to examine shelf-wide sediment dynamics in a coastal setting. The region is characterized by a narrow shelf (~20 km) and ample sediment supply (15 Mt y�¹, ideal precursors to assess the fidelity of the stratigraphic record. Sediments are delivered to this margin via the Waipaoa River which drains a small mountainous catchment (2205 km²) comprised of highly erodible fine-grained lithologies. As part of an NSF-funded project, a time-series of surface seabed properties were used as a foundation to evaluate spatial and temporal changes in sediment dynamics and strata formation on the adjacent margin. Samples were collected on four cruises over 13 months; January, May, and September 2010; and February 2011. Site deposition was assessed using short-lived radionuclides, X-radiography, and through measurement of surface seabed grain-size distribution and organic content. Seabed erodibility was measured with a Gust microcosm device and presented as the total eroded mass (kg m�²) for a given experiment. Generally, sediment deposition was variable, in both space and time and dependent on pre-sampling fluvial and oceanographic conditions. Sediment erodibility also varied; generally sediments were more erodible in water depths <40 m in comparison to deeper areas. Pronounced temporal variation in sediment erodibility was evident at sites located in <40 m water depth. X-radiographs collected from these sites generally show interbedded muds and sands, whereas images of sediments collected from more distal shelf locations are more homogenous, the result of efficient biological mixing in the surface seabed. The temporary and periodic emplacement of flood layers on the Waipaoa margin was most likely responsible for sediment erodibility variation in sites <40 m water depth. X-radiography coupled with grain-size and porosity measurements indicated fluid-mud deposition in Poverty Bay and the region immediate to the bay mouth. Radioisotope measurements suggest that recently deposited layers are more erodible than the average erodibility level calculated for the shelf. Other published research from the York River estuary, VA indicated that the seasonal emplacement of thick sediment deposits following river discharge resulted in higher measured bed erodibility. Post-depositional alteration of the seabed likely also resulted in reduced low erodibility measured on the Waipaoa margin. In summary, recently deposited sediments in the nearshore were prone to erosion and transported to more quiescent and deeper shelf regions, where high rates of modern sediment accumulation have been shown by previous researchers. These processes affected surficial seabed properties which in turn influenced subsequent sediment remobilization.M.S

Cultural Resources Report For The Salt Creek Midstream, LLC Proposed Halcon Pipeline On Texas General Land Office Lands In Reeves County, Texas

Enercon Services, Inc. (ENERCON), in support of Salt Creek Midstream, LLC, conducted an intensive cultural resources survey for the proposed Halcon Pipeline. The proposed pipeline is approximately 43.3 miles (69.7 km) in length and located near Pecos, Texas in Ward and Reeves counties. This report encompasses only the portion of the proposed Halcon Pipeline located on two tracts of Permanent School Fund land in Reeves County, Texas. The Permanent School Fund is administered by the Texas General Land Office (TGLO), a political subdivision of the State of Texas. The portion of the Halcon Pipeline on TGLO lands is approximately 1.8 miles (2.8 km) in length and depicted on the United States Geological Survey (USGS) Quito Draw, Tex. (1963, Photorevised 1981), Old X Ranch, Tex. (1963, Photorevised 1981), Toyah Lake, Tex. (1963) 7.5 Minute Quadrangle maps. The construction corridor consists of a 50 feet (15 m) wide permanent pipeline right-of-way (ROW) and an additional 50 feet (15 m) wide temporary workspace corridor. The cultural resources survey area of potential effect (APE) consists of the 1.8 mile (2.8 km) by 100 feet (30 m) corridor, totaling 21.3 acres (8.6 hectares). The cultural resources investigation is intended to assist in adhering to the 1969 Antiquities Code of Texas and the cultural resources survey on TGLO lands was completed under Texas Antiquities Permit No. 8275. The entire project was supervised by Michael M. Margolis, an ENERCON archeologist who meets the U.S. Secretary of the Interior’s Professional Qualification Standards for archeology as set forth in 36 CFR 61. Prior to the survey, a search of the Texas Archeological Sites Atlas (the Atlas) was conducted by Michael M. Margolis to locate previously recorded archeological sites, archeological surveys, National Register of Historic Places (NRHP) properties, and State Antiquities Landmarks (SALs). Based on the Atlas, one site, 41RV60, has been previously recorded within 1-mile of the APE on TGLO lands. Site 41RV60 is an Early Archaic lithic scatter recorded by URS Corporation in March 2014 and was determined ineligible for listing on the NRHP by the State Historic Preservation Officer (SHPO) on April 8, 2014. Site 41RV60 is located approximately 4,500 feet (1,372 m) from the APE and will not be impacted by construction of the proposed Halcon Pipeline. Two archeological surveys or studies are mapped within 1-mile of the APE on TGLO lands. The cultural resources survey of the Halcon Pipeline APE on TGLO lands was conducted December 1-2, 2017 by Julie Wasinger and Gary D. Edington, ENERCON archeologists who meet the U.S. Secretary of the Interior’s Professional Qualification Standards for archeology as set forth in 36 CFR 61. Salt Creek Midstream, LLC procedures dictate that all standing structures be avoided during construction. Fieldwork was conducted in accordance with the Texas Historical Commission (THC) Archeological Survey Standards for Texas. The cultural resources survey of the Halcon Pipeline APE did not result in finding any historic or prehistoric artifacts, features, cultural lenses, or sites and no artifacts were collected on TGLO lands. Therefore, it is recommended that construction of the proposed Halcon Pipeline on TGLO lands will have no effect on any historic property that may qualify for inclusion on the NRHP or SAL listings. No further cultural resources investigations are recommended prior to construction of the proposed Halcon Pipeline on TGLO lands. If cultural material, including sites, features, or artifacts that are 50 years old or older are encountered within the APE during construction of the Halcon Pipeline on TGLO lands, work in the area must cease and the regional THC Archeologist (512-463-6096) must be notified immediately

Late Holocene Sedimentation and Paleoenvironmental History for the Tidal Marshes of the Potomac and Rappahannock Rivers, Tributaries to Chesapeake Bay

Instrumental tide gauge records indicate that the modern rates of sea-level rise in the Chesapeake Bay more than double the global average of 1.2-1.5 mm yr-1. The primary objective for this study is to establish a relative depositional history for the tidal marshes of the Potomac and Rappahannock Rivers that will help us improve our understanding of processes that influence sedimentation in the proximal tributaries of Chesapeake Bay. Marsh cores were collected from Blandfield Point VA, Tappahannock VA, and Potomac Creek VA. The sedimentary facies include: 1) a lower unit of organic-poor, grey clay with fine sand and silt layers and estuarine foraminifera; and 2) an upper unit of organic-rich clay and peat with abundant brackish to freshwater marsh foraminifera and thecamoebians. AMS 14C dating of bulk marsh sediments yield sedimentation rates at Potomac Creek ranging from 3.04-4.20 mm yr-1 for the past 2500 years. Rates of sedimentation calculated for Blandfield Point indicate 1.37-2.19 mm yr-1 in the basal clays and peat for the past ~3000 years. Foraminiferal census counts indicate a freshening upward trend with a transition from an estuarine Ammobaculites crassus assemblage to a marsh Ammoastuta salsa assemblage with abundant freshwater thecamoebians. The late Holocene history of sedimentation for the marshes indicates that differential compaction, recent land use practices, and climate change have contributed to the resultant freshening-upward environmental trend and variability in sediment accumulation rates between coring sites

Medical student and academic staff perceptions of role models: an analytical cross-sectional study

BACKGROUND: This study explored the associations between the perceptions of students and the perceptions of academic staff about the characteristics of clinical lecturers at the Department of Internal Medicine at Kerman University of Medical Sciences (KUMS). It also assessed what characteristics constitute a 'role model' from the point of view of students and staff. METHODS: Staff and students were questioned about the characteristics of their colleagues and lecturers, respectively. They were asked about 15 characteristics under four headings: personality, teaching skill, group working and overall performance as a role model. Associations between lecturers' characteristics were explored using Pearson correlation and characteristics were allocated into groups by partition cluster method. In addition, predictors of being a valuable lecturer were assessed using logistic regression analysis. RESULTS: Based on staff responses, the strongest association observed was between honesty and being respectful (r = 0.93, p < 0.0001). Based on student responses, the strongest association observed was between being professional and honesty (r = 0.98, p < 0.0001). None of the correlations between student and staff perceptions were significant for any characteristic. Two groups were recognized among the characteristics. group one contained those characteristics which were related to the lecturer's activity; while the second group contained characteristics that were related to the personality or teaching performance of the lecturer. The predictors of lecturer as 'role model' (i.e., perceptions of students) consisted mostly of characteristics from the first group, while the predictors of a 'role model' by fellow academic staff consisted of characteristics that were in both groups. CONCLUSION: These findings showed considerable differences between the perceptions of students about their lecturers when compared with perceptions of staff about their colleagues. Students were more concerned with the personality of their lecturers, while staff also considered their ideas and behaviors. This suggests that a more comprehensive assessment of a lecturer's performance could be obtained by taking into account feedback from both students and colleagues

Public Benefits of Undeveloped Lands on Urban Outskirts: Non-Market Valuation Studies and their Role in Land Use Plans

Over the past three decades, the economics profession has developed methods for estimating the public benefits of green spaces, providing an opportunity to incorporate such information into land-use planning. While federal regulations routinely require such estimates for major regulations, the extent to which they are used in local land use plans is not clear. This paper reviews the literature on public values for lands on urban outskirts, not just to survey their methods or empirical findings, but to evaluate the role they have played--or have the potential to play-- in actual land use plans. Based on interviews with authors and representatives of funding agencies and local land trusts, it appears that academic work has had a mixed reception in the policy world. Reasons for this include a lack of interest in making academic work accessible to policy makers, emphasizing revealed preference methods which are inconsistent with policy priorities related to nonuse values, and emphasis on benefit-cost analyses. Nevertheless, there are examples of success stories that illustrate how such information can play a vital role in the design of conservation policies. Working Paper 07-2

Characterization of multifocal T2*-weighted MRI hypointensities in the basal ganglia of elderly, community-dwelling subjects

AbstractMultifocal T2*-weighted (T2*w) hypointensities in the basal ganglia, which are believed to arise predominantly from mineralized small vessels and perivascular spaces, have been proposed as a biomarker for cerebral small vessel disease. This study provides baseline data on their appearance on conventional structural MRI for improving and automating current manual segmentation methods. Using a published thresholding method, multifocal T2*w hypointensities were manually segmented from whole brain T2*w volumes acquired from 98 community-dwelling subjects in their early 70s. Connected component analysis was used to derive the average T2*w hypointensity count and load per basal ganglia nucleus, as well as the morphology of their connected components, while nonlinear spatial probability mapping yielded their spatial distribution. T1-weighted (T1w), T2-weighted (T2w) and T2*w intensity distributions of basal ganglia T2*w hypointensities and their appearance on T1w and T2w MRI were investigated to gain further insights into the underlying tissue composition. In 75/98 subjects, on average, 3 T2*w hypointensities with a median total volume per intracranial volume of 50.3ppm were located in and around the globus pallidus. Individual hypointensities appeared smooth and spherical with a median volume of 12mm3 and median in-plane area of 4mm2. Spatial probability maps suggested an association between T2*w hypointensities and the point of entry of lenticulostriate arterioles into the brain parenchyma. T1w and T2w and especially the T2*w intensity distributions of these hypointensities, which were negatively skewed, were generally not normally distributed indicating an underlying inhomogeneous tissue structure. Globus pallidus T2*w hypointensities tended to appear hypo- and isointense on T1w and T2w MRI, whereas those from other structures appeared iso- and hypointense. This pattern could be explained by an increased mineralization of the globus pallidus. In conclusion, the characteristic spatial distribution and appearance of multifocal basal ganglia T2*w hypointensities in our elderly cohort on structural MRI appear to support the suggested association with mineralized proximal lenticulostriate arterioles and perivascular spaces