Identification of a cusp catastrophe in a gap-leaping western boundary current

The Luzon Strait is an example of a location where a western boundary current must negotiate a gap in bathymetry. In the gap region, the current can exhibit multiple steady states (leaping the gap or penetrating the gap) and hysteresis (dependence on past flow state). Laboratory experiments on such flows are presented in order to investigate the system behavior in a two-dimensional parameter space of varying flow rate and platform rotation rate. The experiments were performed in a cylindrical tank on a one-meter rotating table. A semi-circular ridge with a gap was inserted over sloping bottom topography in the active region, and the flow was driven by pumping water through sponges. The flow was visualized with the Particle Image Velocimetry method. By varying the flow rate (strength of current), we were able to identify transitions between leaping and penetrating flow states. These transitions bound a region of multiple steady states where hysteresis is present. The dynamics of the system is shown to exhibit a cusp catastrophe classified as A3. The scaling dependencies of some critical properties of the flow are analyzed

A novel method for bone fatigue monitoring and prediction

Bone fatigue, often manifest as stress fractures, is a common injury that plagues many individuals, adversely affect quality of life, and is an obstacle to extended human spaceflight. This manuscript details a pilot study that was conducted to determine if the Phase Space Warping (PSW) methodology could be used to monitor/predict fatigue failure in bone tissue. A Moon\u27s beam experimental apparatus was used to perform variable amplitude fatigue tests on bovine bone specimens. Scanning electron microscopy was used to evaluate the fracture surface and identify the fracture type. The PSW method allowed for successful identification of the various damage modes and may lead to the development of a viable tool for predicting the health and fatigue life of bone

Let\u27s Teach Our Students Legal Technology... But What Should We Include?

A renaissance” is often described as a cultural rebirth, a movement ushering in a modern age and leaving behind the old ways of doing things. There is every indication that we are entering a technology-driven renaissance in the legal profession. Artificial intelligence (AI), “big data,” document automation, e-discovery tools, cloud-based case management systems, and communication and collaboration tools are just a few of the ways that technology is transforming the practice of law in the twenty-first century

Performance of the Syva Direct Fluorescent Antibody Assay for Chlamydia in a Low-Prevalence Population

Chlamydia trachomatis is the most common reportable sexually transmitted disease (STD) in the United States. In the 1980s, rapid diagnostic tests for chlamydia began to replace more cumbersome tissue culture methods. Current data on rapid antigen detection assays demonstrate acceptable sensitivity, specificity, and predictive values in populations with a high prevalence of chlamydia. Few studies report the performance of these assays in a low-prevalence obstetric and gynecologic (Ob/Gyn) population, This study compares the most commonly used direct fluorescent antibody (DFA) assay (Syva Microtrak) with tissue culture (TC) in a low-prevalence population. Endocervical specimens (775) were tested from women at risk for chlamydia infection, and the prevalence was found to be 7.7%. The DFA assay demonstrated a sensitivity of 80% and a specificity of 97% compared with TC. The positive and negative predictive values were 72% and 98%, respectively. The results of this study indicate that the Syva DFA assay lacks the sensitivity and positive predictive value for routine use in Ob/Gyn populations with a lowprevalence of C. trachomatis

Sediment and terrestrial organic carbon budgets for the offshore Ayeyarwady Delta, Myanmar: Establishing a baseline for future change

Large river deltas serve as globally important archives of terrestrial and shallow marine biogeochemical signatures and because of rapid sedimentation have the potential to impact global biogeochemical cycling. The Ayeyarwady Delta in Myanmar ranks as the world\u27s third largest river delta in terms of sediment supply; however, modern increases in regional anthropogenic impacts risk severe alteration to sediment and TerrOC loads within this major system. By investigating modern sediment and terrestrial organic carbon (TerrOC) accumulation within the offshore Ayeyarwady Delta this study estimates baseline sediment and TerrOC budgets for this understudied mega-delta. Using 210Pb geochronology of 27 sediment cores collected from the continental shelf, we estimate that 405 (+52/-47) Mt of sediment, or ~70-80% of fluvial sediment discharged from the Ayeyarwady and Thanlwin rivers (the main inputs to the delta), accumulates there annually. Sediment not retained on the shelf is likely partitioned between the Ayeyarwady floodplain, shoreline accretion, and minor deep-sea export. Estimates of TerrOC (based on δ13C mixing models) were coupled with modern sediment accumulation rates to determine an annual burial of 1.93 (+1.09/-0.15) Mt C on the shelf, with TerrOC burial fluxes being highest in the foreset beds of the subaqueous delta, coincident with the area of highest sediment accumulation rate. Based on estimates of the Ayeyarwady and Thanlwin rivers\u27 TerrOC delivery, an apparent ~100% of TerrOC input is preserved on the continental shelf. However, an across shelf trend of increasing TerrOC degradation with distance offshore is also observed, indicating that while the shelf has high apparent TerrOC sequestration, carbon remineralization is also occurring prior to deposition within the subaqueous delta. Based on these conflicting outcomes, we suggest that input of TerrOC from additional sources other than the Ayeyarwady and Thanlwin rivers roughly balance the observed carbon remineralization. Main additional sources of TerrOC include the Sittang and several smaller rivers, and the Ayeyarwady delta plain below the river gauging station. As anthropogenic development within the Ayeyarwady and Thanlwin watersheds continues to increase, these sediment and TerrOC budgets provide a baseline from which future changes within the offshore Ayeyarwady Delta can be monitored

Cross-Shelf Transport Through the Interaction among a Coastal Jet, a Topographic Wave, and Tides

Shelf break flows are often characterized by along-isobath jets with cross-shelf currents associated with tides and waves guided by variable topography. Here, we address the question: Can a superposition of such flows produce significant aperiodic cross-shelf transport? To answer this question, we use a barotropic analytic model for the jet based on a similarity solution of the shallow water equations over variable topography, a wave disturbance determined by the topography, and a diurnal tidal disturbance. We use standard Lagrangian methods to assess the cross-shelf transport, presenting the results, however, in a Eulerian frame, so as to be amenable to oceanographic observations. The relative roles of the different flow components in cross-shelf transport are assessed through an extensive parameter study. We find that a superposition of all three flow components can indeed produce consequential background aperiodic transport. An application of the model using recent observations from the Texas Shelf demonstrates that a combination of these background mechanisms can produce significant transport under realistic conditions

Routes of Administration and Dose Optimization of Soluble Antigen Arrays in Mice with Experimental Autoimmune Encephalomyelitis

Soluble Antigen Arrays (SAgAs) were developed for treating mice with experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. SAgAs are composed of hyaluronan with grafted EAE antigen and LABL peptide (a ligand of ICAM-1). SAgA dose was tested by varying injection volume, SAgA concentration, and administration schedule. Routes of administration were explored to determine the efficacy of SAgAs when injected intramuscularly, subcutaneously, intraperitoneally, intravenously, or instilled into lungs. Injections proximal to the central nervous system (CNS) were compared to distal injection sites. Intravenous dosing was included to determine if SAgA efficiency results from systemic exposure. Pulmonary instillation was included since reports suggest T cells are licensed in the lungs before moving onto the CNS1,2. Decreasing the volume of injection or SAgA dose reduced treatment efficacy. Treating mice with a single injection on day 4, 7, or 10 also reduced efficacy compared to injecting on all three days. Surprisingly, changing the injection site did not lead to a significant difference in efficacy. Intravenous administration showed efficacy similar to other routes, suggesting SAgAs act systemically. When SAgAs were delivered via pulmonary instillation, however, EAE mice failed to develop any symptoms, suggesting a unique lung mechanism to ameliorate EAE in mice

A global risk assessment of primates under climate and land use/cover scenarios

Primates are facing an impending extinction crisis, driven by extensive habitat loss, land use change, and hunting. Climate change is an additional threat, which alone or in combination with other drivers, may severely impact those taxa unable to track suitable environmental conditions. Here, we investigate the extent of climate and land use/cover (LUC) change-related risks for primates. We employed an analytical approach to objectively select a subset of climate scenarios, for which we then calculated changes in climatic and LUC conditions for 2050 across primate ranges (N=426 species) under a best- and a worst-case scenario. Generalised linear models were used to examine whether these changes varied according to region, conservation status, range extent, and dominant habitat. Finally, we reclassified primate ranges based on different magnitudes of maximum temperature change, and quantified the proportion of ranges overall and of primate hotspots in particular that are likely to be exposed to extreme temperature increases. We found that, under the worst-case scenario, 74% of Neotropical forest-dwelling primates are likely to be exposed to maximum temperature increases up to 7°C. In contrast, 38% of Malagasy savanna primates will experience less pronounced warming of up to 3.5°C. About one quarter of Asian and African primates will face up to 50% crop expansion within their range. Primary land (undisturbed habitat) is expected to disappear across species’ ranges, whereas secondary land (disturbed habitat) will increase by up to 98%. With 86% of primate ranges likely to be exposed to maximum temperature increases >3°C, primate hotspots in the Neotropics are expected to be particularly vulnerable. Our study highlights the fundamental exposure risk of a large percentage of primate ranges to predicted climate and LUC changes. Importantly, our findings underscore the urgency with which climate change mitigation measures need to be implemented to avert primate extinctions on an unprecedented scale