Veterans Education and Research Association of Northern New England

We consider the problem of defining the fracture permeability tensor for each grid block in a rock mass from maps of natural fractures. For this purpose we implement a statistical model of cracked rock developed by M. Oda, where the permeability tensor is related to the crack geometry via a volume average of the contribution from each crack in the population. In this model, tectonic stress is implicitly coupled to fluid flow through an assumed relationship between crack aperture and normal stress across the crack. We have included three enhancements to the basic model. (1) A realistic model of crack closure under stress has been added along with the provision to apply tectonic stresses to the fracture system in any orientation. The application of compressive stress results in fracture closure, and consequently, a reduction in permeability. (2) The fracture permeability can be linearly superimposed onto an arbitrary anisotropic matrix permeability. (3) The fracture surfaces are allowed to slide under the application of shear stress, causing fractures to dilate and result in a permeability increase. Through two examples we demonstrate that significant changes in permeability magnitudes and orientations are possible when tectonic stress is applied to fracture systems.

A 72-year-old, non-insulin-dependent diabetic man with a 2-month history of painful right olecranon bursitis was examined after a fall on the sidewalk that resulted in some abrasion of the skin overlying the elbow. Fluid aspirated from the bursa showed growth of Aspergillus terreus, as did tissue from a bursectomy performed 1 week later. Septic bursitis is an uncommon disease that is nearly always caused by Staphylococcus aureus or hemolytic streptococci. Mycotic bursitis is very rare and this is the first reported instance of any Aspergillus species causing septic bursitis.

Standard geophysical methods for monitoring CO2 injection have severe limitations in many cases. In particular, while the presence or absence of CO2 can be monitored during an injection, it is difficult to quantify changes in CO2 saturation in most reservoirs. We hypothesize that amplitude variation with offset (AVO) attributes may be able to provide more sensitive discriminators for CO2 presence. We propose a workflow useful for the prediction of the AVO response to a CO2 flood under arbitrary fluid saturation and pressure conditions. Using this workflow, we combine laboratory and numerical experiments to upscale and predict the effects of small-scale heterogeneities on AVO response at the seismic scale. This exercise demonstrates the ability of AVO to not only determine the presence or absence of CO2, but also to track changes in CO2 saturation over time.

SignificanceThe quantification of protoporphyrin IX (PpIX) in skin can be used to study photodynamic therapy (PDT) treatments, understand porphyrin mechanisms, and enhance preoperative mapping of non-melanoma skin cancers.AimWe aim to develop a smartphone-based imager for performing simultaneous radiometric fluorescence (FL) and white light (WL) imaging to study the baseline levels, accumulation, and photobleaching of PpIX in skin.ApproachA smartphone-based dual FL and WL imager (sDUO) is introduced alongside new radiometric calibration methods for providing SI-units of measurements in both pre-clinical and clinical settings. These radiometric measurements and corresponding PpIX concentration estimations are applied to clinical measurements to understand mechanistic differences between PDT treatments, accumulation differences between normal tissue and actinic keratosis lesions, and the correlation of photosensitizer concentrations to treatment outcomes.ResultsThe sDUO alongside the developed methods provided radiometric FL measurements (nW / cm2) with a demonstrated sub nanomolar PpIX sensitivity in 1% intralipid phantoms. Patients undergoing PDT treatment of actinic keratosis (AK) lesions were imaged, capturing the increase and subsequent decrease in FL associated with the incubation and irradiation timepoints of lamp-based PDT. Furthermore, the clinical measurements showed mechanistic differences in new daylight-based treatment modalities alongside the selective accumulation of PpIX within AK lesions. The use of the radiometric calibration enabled the reporting of detected PpIX FL in units of nW / cm2 with the use of liquid phantom measurements allowing for the estimation of in-vivo molar concentrations of skin PpIX.ConclusionsThe phantom, pre-clinical, and clinical measurements demonstrated the capability of the sDUO to provide quantitative measurements of PpIX FL. The results demonstrate the use of the sDUO for the quantification of PpIX accumulation and photobleaching in a clinical setting, with implications for improving the diagnosis and treatment of various skin conditions.

A comprehensive laboratory investigation is determining the mechanical properties of tuffs for the Yucca Mountain Site Characterization Project (YMP). Most recently, experiments have been performed on tuff samples from a series of drill holes along the planned alignment of the Exploratory Study Facilities (ESF) north ramp. Unconfined compression and indirect tension experiments were performed and the results are being analyzed with the help of bulk property information. The results on samples from eight of the drill holes are presented. In general, the properties vary widely, but are highly dependent on the sample porosity. The developed relationships between mechanical properties and porosity are powerful tools in the effort to model the rock mass response of Yucca Mountain to the emplacement of the potential high-level radioactive waste repository.

Survival is a fundamental demographic process influencing individual fitness and population dynamics. Automated telemetry systems offer unprecedented opportunities to estimate survival of highly mobile organisms across broad spatial and temporal scales. However, the structure of these tracking networks creates systematic biases that render standard survival models inadequate. Receiver stations are distributed unevenly across landscapes and over time, meaning that individuals taking different movement paths encounter vastly different opportunities for detection. This spatial clustering also creates problematic dependencies: animals detected in receiver-dense areas are more likely to be detected again, while those in sparse areas may disappear from view despite being alive. These observation biases can easily be mistaken for genuine differences in survival, leading to incorrect ecological or conservation inferences. Here, we review the unique challenges posed by automated telemetry data for survival estimation, highlight existing methodological solutions including spatially explicit approaches and modified capture-mark-recapture frameworks, and provide recommendations for advancing this critical application of wildlife tracking networks.

The Connecticut Warbler (Oporornis agilis) is undergoing significant population declines, particularly near the southern limit of its breeding range. To effectively respond to these declines, it is critical to refine population trend estimates and gather comprehensive information about this understudied species throughout its annual cycle. Driven by these concerns, the Connecticut Warbler Working Group, a collaborative international network of scientists and land managers, was established in 2022 to improve understanding of the species' status across its range. In this review, we evaluate population trends, document shifts in the southern breeding range, synthesize ecological insights, and identify key conservation priorities. Analyses indicate a long-term population decline of approximately 50% since 1970, with an overall decline continuing, but showing regional variability. Surveys conducted from 2021 to 2024 across Minnesota, Wisconsin, and Michigan revealed substantial recent range contraction. The species was absent from all but one previously occupied sites in Wisconsin and Michigan, and 77% of previously known sites in Minnesota were no longer occupied. Overall, 75% of historically occupied U.S. sites no longer support breeding populations, emphasizing a sharp range retraction along the species’ southern breeding limits. To address these declines, we propose a conservation strategy that emphasizes building strong international partnerships, implementing high-leverage habitat management on the breeding grounds, and establishing standardized monitoring programs. Targeted research is also needed to fill key knowledge gaps, including mapping non-breeding distribution, identifying critical stopover sites, and assessing demographic factors that limit population growth. Together, these priorities provide a coordinated approach to support Connecticut Warbler conservation across its full annual cycle.

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Experimental results are presented for 24 thermal expansion experiments performed on 5 welded specimens of the Paintbrush tuff recovered from borehole USW SD-12 at Yucca Mountain, Nevada. The thermal expansion experiments were performed at constant confining pressures between 1 and 30 MPa. On three specimens, the highest confining pressure measurements were performed first to inhibit thermally induced damage which might occur at lower confining pressures. At each confining pressure two complete thermal cycles were performed. The specimens were heated (to a nominal temperature of 250 C) and cooled at the nominal rate of 0.319 C per minute. The change in specimen length as a function of temperature was measured with two linear variable displacement transducers mounted on endcaps secured to the specimen. The strain increases with increasing temperature and the strain vs temperature curves are concave upward. On cooling, there is hysteresis at the higher temperatures at all confining pressures. The first heating/cooling cycle is anomalous; hysteresis is pronounced, and a permanent shortening of the specimen is observed at the termination of the cycle. The magnitude of the effect was similar for all five specimens regardless of whether the first cycle was carried out at the highest or lowest confining pressure. For subsequent cycles at all confining pressures, no permanent strain develops, and the strain versus temperature curves re very similar. The mean coefficients of thermal expansion ({alpha}) range from 7.9 to 10.8{sup {minus}6} C{sup {minus}1} at temperatures below 100 C, to 14.2 to 20.6 x 10{sup {minus}6} C{sup {minus}1} at temperatures approaching 250 C. The effect of confining pressure on thermal expansion is small. For temperatures above 175 C, the mean coefficients of thermal expansion decreases by 10--12% as the pressure increases from 1 to 30 MPa.