Improving Multiple Surface Range Estimation of a 3-Dimensional FLASH LADAR in the Presence of Atmospheric Turbulence

Laser Radar sensors can be designed to provide two-dimensional and three-dimensional (3-D) images of a scene from a single laser pulse. Currently, there are various data recording and presentation techniques being developed for 3-D sensors. While the technology is still being proven, many applications are being explored and suggested. As technological advancements are coupled with enhanced signal processing algorithms, it is possible that this technology will present exciting new military capabilities for sensor users. The goal of this work is to develop an algorithm to enhance the utility of 3-D Laser Radar sensors through accurate ranging to multiple surfaces per image pixel while minimizing the effects of diffraction. Via a new 3-D blind deconvolution algorithm, it will be possible to realize numerous enhancements over both traditional Gaussian mixture modeling and single surface range estimation. While traditional Gaussian mixture modeling can effectively model the received pulse, we know that its shape is likely altered due to optical aberrations from the imaging system and the medium through which it is imaging. Simulation examples show that the multi-surface ranging algorithm derived in this work improves range estimation over standard Gaussian mixture modeling and frame-by-frame deconvolution by up to 89% and 85% respectively

Laparoscopic Treatment of a Postoperative Small Bowel Obstruction

An aberrant surgical clip was the cause of internal hernia and small bowel obstruction in this case report

Dietary Magnesium Intake on Heart Rate and Time-to-Fatigue During HIIT Exercise: A Pilot Study

In high intensity interval training (HIIT), bouts of intense work are alternated with less intense periods. HIIT provides an effective stimulus to increase the volume of exercise at or above 90% heart rate maximum (HRmax). Magnesium (Mg) modulates energy metabolism and enzymatic processes. Studies suggest that Mg assists oxidative transport, improves glucose availability, delays lactate accumulation, and reduces inflammation. A gap exists in understanding how Mg affects HIIT. Moreover, the influence of a Vegan (VD) vs Omnivore (OD) diet on HIIT performance outcomes (e.g., heart rate [HR] and time-to-fatigue [TTF]), has yet to be investigated. PURPOSE: This study explored the relations between VD and OD Mg intake and HRmax and TTF during a HIIT treadmill (TM) protocol. It was hypothesized that a higher Mg intake would be associated with a lower HRmax and extended TTF. METHODS: Five healthy participants (1 female, 4 males; 27.2 ± 3.4 years) were enrolled and completed a TM HRmax test and HIIT protocol. The HIIT session comprised four repetitions of 4-minute higher intensity bouts at 85-95% HRmax followed by 3-minute recovery periods at 60-70% HRmax. Dietary Mg was assessed using the ASA24 recall. Values are reported as group mean difference ± SD. Hedges g effect sizes (ES) were calculated, and Pearson correlation coefficients were determined. RESULTS: As expected, Mg intake was higher in VD than OD subjects with a large effect size (558.6 ± 29.0 mg, ES = 19.2). Differences in measured HRmax and TTF between groups was also observed, with VD having a lower HRmax (14.3 ± 1.5 bpm, ES = 9.3) and extended TTF (2.0 ± 0.5 min, ES = 3.9). A strong negative correlation (r = -0.98) was identified between Mg intake and measured HRmax, as well as Mg and RHR (r = -0.73). A moderate positive correlation (r = 0.66) was found for Mg intake and TTF. CONCLUSION: These preliminary data suggest that the higher Mg intake found in persons with a VD is associated with a lower HRmax and extended TTF during HIIT, compared to persons with an OD

Traps and Transformations of Grenadian Water Management

The adaptive cycle metaphor provides insight into how and why social-ecological systems change. Literature on 'resilience thinking' has built upon this foundation and further developed the concepts of resilience, adaptation, and transformation to describe social-ecological system behavior. The resilience-thinking literature also describes systems that do not change, even when such change is desirable, as being in a trapped state. However, relatively little research has explored why such systems are trapped and how to free them. This thesis is the product of doctoral research which resolves how to identify, evaluate, and free a system caught in a maladaptive system trap. The study setting is water management in Grenada, a small island developing state in the southeastern Caribbean. Four research questions guide this study: (1) To what extent is Grenadian water management in a trap?, (2) To what extent is Grenadian water management transformable?, (3) Do current and recent interventions effectively foster or utilize transformability?, and (4) Which interventions should be pursued to facilitate transformation of water management in Grenada?. The study is informed by literature on social-ecological systems and integrated water resources management. Methodologically, the study is an explanatory single-case study of water management in Grenada, conducted from 2012 to 2013. The study utilizes data from semi-structured interviews (n=19), a questionnaire (n=180), a document review (n>200), and observation. The general strategy was to evaluate attempts to transform Grenadian water management within the 3-phase transformation framework described in the resilience-thinking literature. 'Points of failure' in transformation are defined as the cause(s) of a trap, and interventions to relieve the points of failure are proposed. Results indicate Grenadian water management is in a rigidity trap, although it exhibits some capacity to transform. A key point of failure of attempts to transform the Grenadian water sector into an integrated and holistic management system has been an inability to seize windows of opportunity to pass key legislation. I conclude the primary cause for this failure is poor fit among the problem, as perceived by various stakeholders, the proposed solution prescribed by water sector reform proponents, and political reality. In addition, reform proponents focus on advocating for reform to water sector professionals and do little to broker passage of legislation politically. Finally, reform proponents also assume legislation will be effectively implemented, which is not certain. Contributions specific to the Grenadian setting include a post-mortem on why efforts to reform the water sector have failed, described above. Five recommendations are made for future interventions to foster transformation of Grenadian water management: (1) engage residents as part of a vision to create political pressure for proposed solutions, (2) frame the problem with substantial resident input and focus, (3) craft solutions which take advantage of political realities such as funding restrictions, (4) anticipate and prepare for crises, and (5) enlist one or more people or organizations to serve as brokers. Empirical contributions include support for the three-streams framework of seizing windows of opportunity as fundamental to explain transformation of social-ecological systems. The primary conceptual contribution is the development of resilience thinking to illuminate ways to free trapped systems. I begin by providing a nomenclature to quantify and describe traps, which includes the type of trap, the degree of persistence and undesirability of the trap, and recent changes in these properties. Then, I develop a framework to assess transformability of a given system based on the existing 3-phase framework of transformation. When applied empirically, this framework illuminates points of failure of transformation, which I define as the cause of a given trap. Once identified, specific strategies can be devised to foster transformation and to break free of a trap

Wnt signaling in granulosa cell tumors of the ovary

Granulosa cell tumors (GCT), a malignant type of sex-cord stromal tumor, account for approximately 2-5% of all ovarian malignancies. They are often identified before they have spread beyond the ovary, but advanced disease can be quite challenging to treat. Wnt signaling has been suggested to contribute to the formation of GCT. We hypothesized Wnt signaling was involved in human GCT

Image Deblurring and Near-real-time Atmospheric Seeing Estimation through the Employment of Convergence of Variance

A new image reconstruction algorithm is presented that will remove the effect of atmospheric turbulence on motion compensated frame average images. The primary focus of this research was to develop a blind deconvolution technique that could be employed in a tactical military environment where both time and computational power are limited. Additionally, this technique can be employed to measure atmospheric seeing conditions. In a blind deconvolution fashion, the algorithm simultaneously computes a high resolution image and an average model for the atmospheric blur parameterized by Fried’s seeing parameter. The difference in this approach is that it does not assume a prior distribution for the seeing parameter, rather it assesses the convergence of the image’s variance as the stopping criteria and identification of the proper seeing parameter from a range of candidate values. Experimental results show that the convergence of variance technique allows for estimation of the seeing parameter accurate to within 0.5 cm and often even better depending on the signal to noise ratio

Core handling and processing for the WAIS Divide ice-core project

On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are described and discussed

Core handling and processing for the WAIS Divide ice-core project

On 1 December 2011 the West Antarctic Ice Sheet (WAIS) Divide ice-core project reached its final depth of 3405 m. The WAIS Divide ice core is not only the longest US ice core to date, but is also the highest-quality deep ice core, including ice from the brittle ice zone, that the US has ever recovered. The methods used at WAIS Divide to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the US National Ice Core Laboratory (NICL) and the methods used to process and sample the ice at the NICL are described and discussed

Differential Effects of HOXB4 on Nonhuman Primate Short- and Long-Term Repopulating Cells

BACKGROUND: Hematopoietic stem cells (HSCs) or repopulating cells are able to self-renew and differentiate into cells of all hematopoietic lineages, and they can be enriched using the CD34 cell surface marker. Because of this unique property, HSCs have been used for HSC transplantation and gene therapy applications. However, the inability to expand HSCs has been a significant limitation for clinical applications. Here we examine, in a clinically relevant nonhuman primate model, the ability of HOXB4 to expand HSCs to potentially overcome this limitation. METHODS AND FINDINGS: Using a competitive repopulation assay, we directly compared in six animals engraftment of HOXB4GFP (HOXB4 green fluorescent protein) and control (yellow fluorescent protein [YFP])–transduced and expanded CD34 (+) cells. In three animals, cells were infused after a 3-d transduction culture, while in three other animals cells were infused after an additional 6–9 d of ex vivo expansion. We demonstrate that HOXB4 overexpression resulted in superior engraftment in all animals. The most dramatic effect of HOXB4 was observed early after transplantation, resulting in an up to 56-fold higher engraftment compared to the control cells. At 6 mo after transplantation, the proportion of marker gene–expressing cells in peripheral blood was still up to 5-fold higher for HOXB4GFP compared to YFP-transduced cells. CONCLUSIONS: These data demonstrate that HOXB4 overexpression in CD34 (+) cells has a dramatic effect on expansion and engraftment of short-term repopulating cells and a significant, but less pronounced, effect on long-term repopulating cells. These data should have important implications for the expansion and transplantation of HSCs, in particular for cord blood transplantations where often only suboptimal numbers of HSCs are available