Service-Learning Practice in Upper Division Geoscience Courses: Bridging Undergraduate Learning, Teaching, and Research

This article describes the use of service-learning practice in geoscience courses taught at the University of Connecticut. The stated objectives for instituting this practice are: to foster student interest in earth sciences through community service; to enhance university outreach through interactions with communities; to enhance students' learning ability by applying course knowledge to real-world problems; and to encourage the student-centered learning process and team-work as cooperative learning. Favorable responses from both students and local community leaders show that service-learning is an effective way to improve geological undergraduate learning. Educational levels: Graduate or professional

Groundwater Recharge under Changing Landuses and Climate Variability: The Case of Baro-Akobo River Basin, Ethiopia

Impacts of landuse/landcover changes coupled with climate variability are well felt in areas of pristine environments like the dominantly high rainforest covered Baro-Akobo river basin of Ethiopia that form the Sobbat River system. Recharge is one of the hydrologic components to be influenced by induced anthropogenic changes. Quantifying and understanding changes in recharge and related hydrologic parameters help to properly manage the water resources and protect such vulnerable hydro-ecosystems. Among the various recharge estimation methods, WetSpass model is used for its capability to estimate recharge by coupling surface-subsurface water balances. It is also used to simulate yearly or seasonal averages of groundwater recharge, evapotranspiration and runoff that help to understand the basin’s hydro ecosystems dynamics. Modeling is done for the entire river basin of Baro-Akobo, taking into account landuse/landcover changes, varying climate and other physical parameters over the past four decades. Simulation results are validated using previous estimates, empirical methods using data from monitoring wells and isotope measurements. Bias corrected Climate Forecast System Reanalysis (CFSR) data are used to fill gaps in data scarce areas and to generate potential evapotranspiration. Field measurements, secondary data and fifteen months long three hourly well monitoring data are used to determine seasonal depth fluctuations of the groundwater. Landuse/landcover change of three periods, 1973 to 2014, and planned large scale development activities are used as inputs to see induced corresponding changes in the hydro-ecosystem. The simulated result showed small increase in runoff and despite the increase in temperature, there is a decrease in total evapotranspiration and significant increase in recharge in the recent period. The simulated result is also in line with the hydrogeologic characteristics of the basin making it a basin with low recharge as compared to basins in the central and eastern parts of the country. Coupled with other hydrological and hydrogeological characteristics of the basin, the result helps to understand the reason for finding large volume of surface flow entering the Machar wetlands and eventually reaching the White Nile from a relatively small watershed. Keywords: Land use- Land cover; Recharge; climate variability; WetSpass; Geolog

Transcranial ultrasonic wave propagation simulation: skull insertion loss and recovery

Severe energy dissipation and waveform aberration in ultrasonic wave propagation due to the human skull remain major challenges to achieving good focus in high intensity focused ultrasound (HIFU) brain therapy and high-resolution thermoacoustic tomography (TAT) of the human brain. With the inclusion of the skull insertion loss, we numerically simulated the ultrasonic wave propagation using the pseudospectral time domain (PSTD) algorithm for TAT setup. We then applied the redatuming scheme through downward and upward continuation originated in seismic signal processing to eliminate the diffraction caused by the irregularity of the skull and to recover the insertion loss due mainly to the diploes layer of the skull. This approach, after further validation, is aimed to recover wave energy dissipation and waveform aberration in ultrasonic measurements applied to both trans-skull imaging (ultrasound propagates outward) and therapy (ultrasound propagates inward)

Investigation of the 1727 Newbury, Massachusetts, USA, earthquake using LiDAR imagery and P-wave velocity tomography

High-resolution LiDAR (light detection and ranging) images of northeastern Massachusetts and southeastern New Hampshire reveal a 10-km-long, NW-SE-oriented topographic lineament in northeastern Massachusetts that we interpret to be the surface expression of a SW-dipping thrust fault along which the 1727 Newbury, Massachusetts, earthquake occurred. The Newburyport lineament coincides with the northeast edge of a 10-kmlong, NW-SE-oriented ridge, herein named Merrimack ridge, that parallels the NW-SE-trending segment of the Merrimack River downstream from where it bends 90° to the southeast. The northwestern end of the Newburyport lineament coincides with a 1-km-long, ~7- to 15-m-high, NE-facing Newburyport scarp that is located just south of the bend in the river. The Newburyport lineament also parallels the NW-SE-oriented nodal planes of the focal mechanism that was generated for the 1999 Amesbury, Massachusetts, earthquake. A P-wave velocity tomographic model generated from a seismic-refraction profile across the Newburyport scarp shows a ~40-m-wide low-velocity zone dipping ~41° SW. Velocities along this zone decrease 15–50%, which suggests that the Newburyport lineament is associated with the surface expression of a SW-dipping brittle fault zone. The LiDAR images also revealed three other NW-SE-trending lineaments in the study area

Down-Regulation of EBV-LMP1 Radio-Sensitizes Nasal Pharyngeal Carcinoma Cells via NF-κB Regulated ATM Expression

BACKGROUND:The latent membrane protein 1 (LMP1) encoded by EBV is expressed in the majority of EBV-associated human malignancies and has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. In previous studies we experimentally demonstrated that down-regulation of LMP1 expression by DNAzymes could increase radiosensitivity both in cells and in a xenograft NPC model in mice. RESULTS:In this study we explored the molecular mechanisms underlying the radiosensitization caused by the down-regulation of LMP1 in nasopharyngeal carcinoma. It was confirmed that LMP1 could up-regulate ATM expression in NPCs. Bioinformatic analysis of the ATM ptomoter region revealed three tentative binding sites for NF-κB. By using a specific inhibitor of NF-κB signaling and the dominant negative mutant of IkappaB, it was shown that the ATM expression in CNE1-LMP1 cells could be efficiently suppressed. Inhibition of LMP1 expression by the DNAzyme led to attenuation of the NF-κB DNA binding activity. We further showed that the silence of ATM expression by ATM-targeted siRNA could enhance the radiosensitivity in LMP1 positive NPC cells. CONCLUSIONS:Together, our results indicate that ATM expression can be regulated by LMP1 via the NF-κB pathways through direct promoter binding, which resulted in the change of radiosensitivity in NPCs

An Efficacious Endometrial Sampler for Screening Endometrial Cancer

Recently, the research on early detection of precancerous change and endometrial carcinoma has been focusing on minimally invasive procedures for screening. On this basis, we aim to verify the feasibility of endometrial samplers for screening endometrial cancer using Li Brush. We recruited patients undergoing hysterectomy for different diseases from the Inpatient Department of the Department of Obstetrics and Gynecology. Before surgery, endometrial cells were collected by Li Brush. The cytopathologic diagnosis from Li Brush and the histopathologic diagnosis from hysterectomy in the same patient were compared to calculate sensitivity (Se), specificity (Sp), false-negative rate (FNR), false-positive rate (FPR), positive predictive value (PV+) %, and negative predictive value (PV-). The research enrolled 293 women into this self-controlled trial. According to the hypothesis test of paired four lattices, we obtained the following indicators: Se 92.73, Sp 98.15, FNR 7.27, FPR 1.85, PV+92.73, and PV−98.15%. The endometrial sampler Li Brush is an efficacious instrument for screening endometrial cancer