Determining the Source of Anomalous Segments in a Karst Stream

Southeastern Minnesota is characterized by an extensive karst network. In Kentucky, Carter Caves State Resort Park is a similar karst area that has exhibited karst anomalies, or `bumps,\u27 in a longitudinal stream profile. This study aimed to determine if these same karst anomalies can be found in southeast Minnesota, where LiDAR data are available, and if these bumps are actually karst features. Profiles of carbonate and siliciclastic streams were observed to determine if the presence of anomalies in only carbonate streams, both lithologies, or neither. Another objective was to determine if GIS could be an effective method at generating these profiles. Field data were collected to verify the GIS derived profiles. Stream shapes were also analyzed to determine what dominant processes occur in the area. No karst features were identified within profiles of streams in southeast Minnesota. However, GIS proved to be a useful tool in creating profiles from 1- and 3-meter DEMs. GIS was able to locate where changes in slope occurred; this was verified by field data. Some differences in profile can be attributed to the continuously changing morphology due to scour and fill processes that occur in these streams. Filled DEMs were also created, but ultimately not used because they eliminated some important features. Stream gradient index values were calculated that accounts for the distance from the source, length of reach, and elevation change of the reach. Values were calculated for carbonate and siliciclastic reaches of streams and were found to be statistically similar to each other, indicating that stream-bed lithology is not a dominant process affecting the stream shape in this area. Four main stream shapes were identified: linear, concave, convex, and stepped. Linear streams were the dominant shape, followed by concave. There was no statistically significant difference between shapes for the carbonate and siliciclastic rocks. This further supports the claim that lithology is not playing a role in the streams\u27 morphology in this study area. It is likely that the erosion of legacy sediments from past farming practices is playing the largest role in sculpting the streams. Another factor affecting shape is land use, which increases erosion in this area

Through the Eyes of Visitors: Understanding the Contexts of the Visitor Photo Study at the Denver Museum of Nature & Science

This case study describes the analysis of the Visitor Photo Study, a study in which visitors to the Denver Museum of Nature & Science documented their visit through pictures. The origins, implementation, and findings of the Visitor Photo Study are considered within the contexts of the fields of Community-Based Research (Strand, Marullo, Cutforth, Stoecker, & Donohue, 2003b), Visual Studies (Marshall & Rossman, 2011; Pink, 2007), and Visitor Studies (Visitor Studies Association, 2012). This study considers the extent to which the principles and elements of each of these fields were present in the Visitor Photo Study, which elements were not fully realized or were missing from the study, and ways in which the Visitor Photo Study extends each of these fields. The value of this type of analysis and implications for museums, faculty, and students are also discussed

Case Report: Cerebral Edema and Tonsillar Herniation Leading to Brain Death After Cocaine Use in a Patient with End-Stage Renal Disease

The effect of cocaine use on the cerebral vasculature is well understood, with potential for ischemic or hemorrhagic stroke. The risk of adverse effects can be prolonged and amplified in patients with renal dysfunction and uremia. Uremia-induced osmotic gradients and upregulation of aquaporin channels along with cocaine-induced blood-brain barrier degradation may act synergistically. We present the first known case of a non-compliant dialysis patient who suffers cerebral edema, tonsillar herniation, and brain death following cocaine use. A 32-year-old female with end-stage renal disease presented with shortness of breath and flu-like symptoms for one week and was alert and oriented with no neurologic deficits. The patient had missed her last 5 dialysis treatments and labs revealed hyperkalemia and uremia. Urine drug screen was positive for cocaine, opiates, and tetrahydrocannabinol (THC). Following dialysis and metabolic correction, she developed an irregular respiratory pattern and stridor and received neck computed tomography (CT). The patient became unresponsive with dilated and nonreactive pupils. CT revealed absent intraluminal carotid and vertebral artery flow at the skull base, cerebellar tonsil herniation, and anoxic brain injury. Vital signs were maintained, and cerebral edema was managed with 45-degree head-of-bed elevation and mannitol. Following cerebral edema treatment, the patient had preserved respiratory drive, fixed and dilated pupils, no corneal reflex, no cough or gag reflex, and negative oculocephalic reflex. Repeat cranial CT angiography revealed bilateral hemispheric edema, basal subarachnoid hemorrhage, and confirmed absent intracranial blood flow. Brain death was diagnosed with a radioisotope cerebral blood flow study. The use of cocaine in patients with renal dysfunction may increase the risk of cerebral edema and tonsillar herniation due to synergistic physiologic effects. Physicians should be aware of this interaction to allow for preventative measures

Centimeter to decimeter hollow concretions and voids in Gale Crater sediments, Mars

Voids and hollow spheroids between ∼1 and 23 cm in diameter occur at several locations along the traverse of the Curiosity rover in Gale crater, Mars. These hollow spherical features are significantly different from anything observed in previous landed missions. The voids appear in dark-toned, rough-textured outcrops, most notably at Point Lake (sols 302-305) and Twin Cairns Island (sol 343). Point Lake displays both voids and cemented spheroids in close proximity; other locations show one or the other form. The spheroids have 1-4 mm thick walls and appear relatively dark-toned in all cases, some with a reddish hue. Only one hollow spheroid (Winnipesaukee, sol 653) was analyzed for composition, appearing mafic (Fe-rich), in contrast to the relatively felsic host rock. The interior surface of the spheroid appears to have a similar composition to the exterior with the possible exceptions of being more hydrated and slightly depleted in Fe and K. Origins of the spheroids as Martian tektites or volcanic bombs appear unlikely due to their hollow and relatively fragile nature and the absence of in-place clearly igneous rocks. A more likely explanation to both the voids and the hollow spheroids is reaction of reduced iron with oxidizing groundwater followed by some re-precipitation as cemented rind concretions at a chemical reaction front. Although some terrestrial concretion analogs are produced from a precursor siderite or pyrite, diagenetic minerals could also be direct precipitates for other terrestrial concretions. The Gale sediments differ from terrestrial sandstones in their high initial iron content, perhaps facilitating a higher occurrence of such diagenetic reactions

IN-SITU SAMPLING AND CHARACTERIZATION OF NATURALLY OCCURRING MARINE METHANE HYDRATE USING THE D/V JOIDES RESOLUTION

The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the preparation of tools and measurement systems for deployment, testing and use on ODP Leg 204, which will study hydrate deposits on Hydrate Ridge, offshore Oregon. Additional accomplishments were related to the postcruise evaluation of tools and measurements systems used on ODP Leg 201 along the Peru margin from January through March, 2002. The operational results from the use of the Pressure Core Sampler (PCS) tool and the PCS Gas Manifold on ODP Leg 201 are evaluated in this progress report in order to prepare for the upcoming deployments on ODP Leg 204 in July, 2002. The PCS was deployed 17 times during ODP Leg 201 and successfully retrieved cores from a broad range of lithologies and sediment depths along the Peru margin. Eleven deployments were entirely successful, collecting between 0.5 and 1.0 meters of sediment at greater than 75% of hydrostatic pressure. The PCS gas manifold was used in conjunction with the Pressure Core Sampler (PCS) throughout ODP Leg 201 to measure the total volume and composition of gases recovered in sediment cores associated with methane gas hydrates. The FUGRO Pressure Corer (FPC), one of the HYACE/HYACINTH pressure coring tools, was also deployed on the D/V JOIDES Resolution during ODP Legs 201 to field-test this coring system at three shallow-water sites located offshore Peru. The field-testing of these tools provides a corollary benefit to DOE/NETL at no cost to this project. The testing of these tools on the D/V JOIDES Resolution was negotiated as part of a cooperative agreement between JOI/ODP and the HYACINTH partners. The DVTP, DVTP-P, APC-methane, and APC-Temperature tools (ODP memory tools) were used extensively during ODP Leg 201. The data obtained from the successful deployments of these tools is still being evaluated by the scientists and engineers involved in this testing; however, preliminary results are presented in this report. An infrared-thermal imaging system (IR-TIS) was deployed for the first time on ODP Leg 201. This system was used to identify methane hydrate intervals in the recovered cores. Initial discussions of these experiments are provided in this report. This report is an overview of the field measurements made on recovered sediment cores and the downhole measurements made during ODP Leg 201. These results are currently being used to incorporate the ''lessons learned'' from these deployments to prepare for a dedicated ODP leg to study the characteristics of naturally-occurring hydrates in the subsurface environment of Hydrate Ridge, offshore Oregon during ODP Leg 204, which will take place from July through September, 2002

Conference on Best Practices for Managing \u3cem\u3eDaubert\u3c/em\u3e Questions

This article is a transcript of the Philip D. Reed Lecture Series Conference on Best Practices for Managing Daubert Questions, held on October 25, 2019, at Vanderbilt Law School under the sponsorship of the Judicial Conference Advisory Committee on Evidence Rules. The transcript has been lightly edited and represents the panelists’ individual views only and in no way reflects those of their affiliated firms, organizations, law schools, or the judiciary

Novel protective role for MAP kinase phosphatase 2 in inflammatory arthritis

Objectives: We have previously shown mitogen-activated protein kinase phosphatase 2 (MKP-2) to be a key regulator of proinflammatory cytokines in macrophages. In the study presented here, we investigated the role of MKP-2 in inflammatory arthritis with a particular focus on neutrophils. Methods: T o achieve this, we subjected MKP-2 deficient and wild type mice to collagen antibody induced arthritis, an innate model of arthritis, and determined disease pathology. To further our investigation, we depleted neutrophils in a prophylactic and therapeutic fashion. Last, we used chemotaxis assays to analyse the impact of MKP- 2 deletion on neutrophil migration. Results MKP-2-/- mice showed a significant increase in disease pathology linked to elevated levels of proarthritic cytokines and chemokines TNF-α, IL-6 and MCP-1 in comparison to wild type controls. This phenotype is prevented or abolished after administration of neutrophil depleting antibody prior or after onset of disease, respectively. While MCP-1 levels were not affected, neutrophil depletion diminished TNF-α and reduced IL-6, thus linking these cytokines to neutrophils. In vivo imaging showed that MKP-2-/- mice had an increased influx of neutrophils into affected joints, which was higher and potentially prolonged than in wild type animals. Furthermore, using chemotaxis assays we revealed that MKP-2 deficient neutrophils migrate faster towards a Leukotriene B4 gradient. This process correlated with a reduced phosphorylation of ERK in MKP-2-/- neutrophils. Conclusions: T his is the first study to show a protective role for MKP-2 in inflammatory arthritis