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Incubation assay metrics describe different aspects of dissolved carbon degradation
No full textDissolved organic matter (DOM) incubation experiments are an important method for disentangling the effects of dissolved organic carbon (DOC) characteristics and microbial community composition on carbon (C) bioreactivity. However, common quantification metrics (ΔDOC, biodegradability, C removal rate) measure different aspects of C degradation and can change through time, suggesting experimental conclusions may depend on the metric used and the time of measurement. We performed an incubation experiment crossing varying DOM sources and microbial communities and synthesized published experimental data to explore (1) whether the interpretation of C degradation activity changed with the metric used, (2) how incubation duration impacted measures of degradation, and (3) how these different metrics compared across studies. Through our incubation experiment, we found that all metrics agreed regarding which treatments were associated with the greatest amounts of C degradation, and in all cases we observed peak C removal rates within 24 h of incubation initiation. However, our literature synthesis found that just 10% of studies sampled within the first 24 h of incubation initiation, suggesting common measurement intervals may miss peak C removal rates. Using these findings, we propose combinations of C degradation metrics and sampling frequencies that may be especially effective for detecting differences in C bioavailability, microbial activity, or C degradation
Flow dynamic differences between Kawasaki Disease patients with coronary artery aneurysms and ectasia
No full textBackground: Untreated Kawasaki Disease (KD) can lead to coronary artery (CA) dilations, such as CA aneurysms (CAA), CA ectasia (CAE), or both (CAA + CAE). Currently, therapeutic decisions rely solely on geometric measurements, which have limitations. This study aims to correlate differences in flow dynamics between CAA, CAE, and CAA + CAE with clinical outcomes and thrombotic potential. Methods: A multicenter retrospective study was performed using a total of 50 dilation models from patients with KD. Dilations were categorized as either CAA (n = 30), CAE (n = 14), or CAA + CAE (n = 6). Patient-specific 3D digital models of the CAs were created for each patient. Geometric measurements of each CA were recorded. Flow simulations were conducted and hemodynamic metrics such as time average wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and normalized average wall shear stress divergence (AWSS) were calculated. Results: CAAs had the largest dilations and entrance diameters. The dilation length and aspect ratio were higher for CAEs. CAAs exhibited consistently low velocity and low TAWSS with extensive regions of co-localized high RRT and OSI, and AWSS source points. CAEs showed elevated RRT in some cases but minimal OSI with little spatial overlap between metrics. CAA+CAEs showed variable and diffuse flow patterns with limited co-localization. Conclusion: Flow dynamics vary significantly across dilation morphologies in KD. Patients with only CAAs present hemodynamic data associated with the highest likelihood of thrombosis. Hemodynamic metrics may serve as mechanistic markers for thrombogenic potential and should be considered alongside anatomical measurements in future risk stratification efforts
Cardiovascular and Aortic Wave Reflection Responses to Evening Binge Alcohol Consumption
No full textEvening binge alcohol consumption contributes to sleep disruption and autonomic dysregulation that persists into the following morning. However, its impact on morning-after arterial stiffness and aortic wave reflection remains unknown. Using a randomized, crossover, fluid-controlled design, we hypothesized that heart rate (HR), carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx), and aortic pulsatile load (APL) would be increased acutely after binge drinking at night (study 1) and the morning-after binge drinking (study 2). Participants (n=33, 18 females, 15 males, age 25±1 years, BMI: 27±1 kg/m) completed binge alcohol (4-5 drink equivalent) and fluid control protocols. Study 1 examined cardiovascular responses during resting baseline and within 30 minutes of evening alcohol consumption, while study 2 examined cardiovascular responses within 15 minutes of waking the morning-after binge alcohol or fluid control. In Study 1, HR and APL increased after the final dose of alcohol (p\u3c 0.001) but decreased with fluid control. In Study 2, morning HR (63±2 vs. 57±1 beats/min, p\u3c 0.001), APL (2060±82 vs. 1857±66 a.u., p=0.012) and AIx normalized to 75 beats per minute (AIx@75) (6.5±2.4 vs. 2.9±2.5%, p=0.042) were increased, while unadjusted AIx was unchanged, after binge alcohol compared to fluid control. cfPWV was not altered by binge alcohol acutely (study 1) or the morning-after (study 2). Our results indicate evening binge alcohol consumption elicited acute increases of HR and APL and morning-after increases HR, APL, and AIx@75. These findings highlight physiological mechanisms that might contribute to well-documented associations between binge alcohol consumption and heightened cardiovascular risk
Reciprocals of false theta functions
No full textWe investigate reciprocals of false theta functions, producing results such as congruences, simple asymptotic bounds, and combinatorial identities. Of particular interest is a connection between 1/Ψ(-q2,q) and the truncated pentagonal number theorem of Andrews and Merca. We record a useful dissection identity analogous to the known theta function dissection
SMALL MAMMAL DIET AS AN INDICATOR OF LYME DISEASE AND THE ROAD TO ENDEMICITY IN MICHIGAN’S UPPER PENINSULA
No full textLyme disease is expanding in the Upper Midwest due to climate change, forest degradation, and shifting wildlife communities. Small mammals are key reservoir hosts, and their foraging behavior offers insight into environmental conditions that sustain pathogen transmission. We used DNA metabarcoding to investigate small mammal diets across seasonal, spatial, and infection gradients in Michigan’s Upper Peninsula. We identified dominant dietary plant and arthropod taxa, seasonal shifts, and slight variation by species, site, and Lyme infection status. Taxa associated with Lyme-positive individuals were primarily linked to moist, edge, and disturbed habitats, areas that also support ticks and disease spread. These results suggest diet can reflect habitat characteristics relevant to infection risk and support the value of metabarcoding for ecological surveillance in emerging disease systems. To complement this work, we summarized a citizen science tick collection program and found that the Upper Peninsula qualifies as a high-incidence region under CDC definitions
INVESTIGATION OF ACOUSTIC ATTENUATION METHODS AS A NOISE CONTROL DEVICE IN HYDRAULICS
No full textThis research covers a variety of hydraulic configurations to characterize wave propagation and transmission loss. This is mathematically calculated via a transfer matrix that separates the acoustic pressure waves into upstream and downstream. Although there is a solid mathematical basis (ASTM E2611) for these calculations, a range of tests were performed to compare the accuracy of these calculations to real-time data. The main set of tests were performed on a two-part impedance tube setup with a sample section in the center. A total of 13 dynamic pressure transducers (DPT’s) are placed along the bench to record the pressure throughout testing. Three methods known as side branch resonators, Herschel-Quincke tubes, and simple expansion muffler methods all use vibroacoustic attenuation and have been tested and validated on this test bench to better understand the attenuation properties. With this data, these properties can now be accurately characterized through baseline, side branch resonator, and Herschel Quincke (HQ) tube tuning configurations. All of these concepts have been supported by simulation to further validate all experimental results
Identifying the Desired Word Suggestion in Simultaneous Audio
No full textWe explore a method for presenting word suggestions for non-visual text input using simultaneous voices. We conduct two perceptual studies and investigate the impact of different presentations of voices on a user\u27s ability to detect which voice, if any, spoke their desired word. Our sets of words simulated the word suggestions of a predictive keyboard during real-world text input. We find that when voices are simultaneous, user accuracy decreases significantly with each added word suggestion. However, adding a slight 0.15 s delay between the start of each subsequent word allows two simultaneous words to be presented with no significant decrease in accuracy compared to presenting two words sequentially (84% simultaneous versus 86% sequential). This allows two word suggestions to be presented to the user 32% faster than sequential playback without decreasing accuracy
Chlorocatechol-functionalized gelatin nanoparticles as a hemostatic agent with antimicrobial properties
No full textHemorrhage is one of the leading preventable causes of death associated with trauma, which is often complicated by wound infection. Current hemostatic materials are not ideal and lack antimicrobial properties needed for infection prevention. Here, we tested the feasibility for 6-chlorodopamine-functionalized gelatin (GDC) nanoparticles to function as a hemostatic powder with strong tissue adhesion and antibacterial properties. 6-Chlorodopamine contains a catechol sidechain that is further modified with an electron withdrawing chlorine atom, and provides strong tissue adhesion and antimicrobial property. These gelatin nanoparticles are not covalently crosslinked, which enablde them to rapidly transition into an adhesive film when hydrated with an aqueous solution or blood. The chlorination of catechol significantly increased structural integrity, interfacial bonding to tissue surface, and the rate of film formation. Additionally, GDC nanoparticles are noncytotoxic and nonhemolytic, and effectively killed Gram-positive (Staphylococcus epidermidis, Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Finally, GDC nanoparticles achieved significantly faster hemostasis and reduced blood loss when compared to a commercial fibrin glue, Tisseel, in tail transection and liver hemorrhage models performed in mice. These findings highlight the potential of GDC nanoparticle as a versatile, multifunctional hemostatic agent capable of both rapid hemorrhage control and infection prevention. Statement of Significance: Existing hemostatic agents often lack effective antimicrobial properties and may not be suited for application in a prehospital setting. This work evaluated a multifunctional, hemostatic nanoparticle that addresses key challenges in hemorrhage control and infection prevention, through a simple, bioinspired formulation. Gelatin nanoparticles were functionalized with chlorocatechol (GDC) that can rapidly transition into adhesive films when hydrated with blood. Chlorocatechol imparted the nanoparticles with strong tissue adhesion, film integrity, and antimicrobial property. In mouse hemorrhage models, GDC significantly reduced blood loss and bleeding time when compared to a commercial fibrin sealant. This powder-form material requires no mixing or specialized equipment to deploy, which makes it potentially suitable for application in a prehospital setting
Entity Backdoor Attacks Against Fine-Tuned Models
No full textFine-tuning is a training paradigm that allows large models to achieve strong performance on downstream tasks with a small number of samples and minimal training time. However, this study reveals that the models fine-tuned from pre-trained models are vulnerable to a new threat called an entity backdoor attack. Entity backdoor attacks are a new type of backdoor attack that can use arbitrary instances in a given entity to trigger a backdoor attack. More importantly, the arbitrary instances (i.e., poisoned example) in the entity are visually similar to the clean example. For example, an entity backdoor attack can use the husky dog (which belongs to the dog entity) to trigger the stop sign class in the traffic recognition task, but the poisoned example in the training dataset is visually like a stop sign. The advantages of entity backdoor attacks over traditional backdoor attacks are twofold. First, entity backdoor attacks are triggered more stealthily because they do not require a specially defined trigger pattern superimposed on a normal image to trigger the backdoor attack. The instance (e.g., a husky dog) itself is a trigger, using the instance can directly trigger the backdoor attack. Second, the poisoned examples in the training datasets of entity backdoor attacks are more stealthy because we use very small perturbations to generate the poisoned examples, making them hard to distinguish from the clean examples. Experiments on multiple datasets show that systems using fine-tuned models are vulnerable to the threat of entity backdoor attacks
Near-factorizations of dihedral groups
No full textWe investigate near-factorizations of nonabelian groups, concentrating on dihedral groups. We show that some known constructions of near-factorizations in dihedral groups yield equivalent near-factorizations. In fact, there are very few known examples of nonequivalent near-factorizations in dihedral or other nonabelian groups; we provide some new examples with the aid of the computer. We also analyse a construction for near-factorizations in dihedral groups from near-factorizations in cyclic groups, due to Pêcher, and we investigate when nonequivalent near-factorizations can be obtained by this method