Extent and mechanism of sealing in transected giant axons of squid and earthworms

Transected axons are often assumed to seal at their cut ends by the formation of continuous membrane barriers that allow for the restoration of function in the axonal stumps. We have used several electrophysiological measures (membrane potential, input resistance, injury current density) and several morphological measures (phase-contrast, video-enhanced differential interference contrast, light, and electron microscopies) of living and fixed material to assess the extent and mechanism of sealing within hours after transecting giant axons of squid (Loligo pealeiand Sepioteuthis lessoniana) and earthworms (Lumbricus terrestris). Our electrophysiological data suggest that the proximal and distal ends of transected squid giant axons do not completely seal within 2.5 hr in physiological saline. In contrast, the same set of measures suggest that proximal and distal ends of transected earthworm giant axons seal within 1 hr in physiological saline. Our morphological data show that the cut ends of both squid and earthworm axons constrict, but that a 20- 70-am-diameter opening always remains at the cut end that is filled with vesicles. Axonal transection induces the formation of vesicles that are observed in the axoplasm within minutes in standard salines and that rapidly migrate to the cut ends. These injury-induced vesicles are loosely packed near the cut ends of squid giant axons, which do not functionally seal within 2.5 hr of transection. In contrast, vesicles formed a tightly packed plug at the cut ends of earthworm medial giant axons, which do functionally seal within 1 hr of transection in physiological saline. Since we detect no single continuous membrane that spans the cut end, sealing does not appear to occur by the fusion of constricted axolemmal membrane or the formation of a membranous partition at the cut end. Rather, our data are consistent with the hypothesis that a tightly packed vesicular plug is responsible for sealing of earthworm giant axons.This work was supported in part by NIH Grant NS31256 and ONR Grant N00014-90-J-1137 to H.M.F., an NIAAA fellowship to T.L.K., and an ATP grant to G.D.B.Neuroscienc

Multiview classification and dimensionality reduction of scalp and intracranial EEG data through tensor factorisation

Electroencephalography (EEG) signals arise as a mixture of various neural processes that occur in different spatial, frequency and temporal locations. In classification paradigms, algorithms are developed that can distinguish between these processes. In this work, we apply tensor factorisation to a set of EEG data from a group of epileptic patients and factorise the data into three modes; space, time and frequency with each mode containing a number of components or signatures. We train separate classifiers on various feature sets corresponding to complementary combinations of those modes and components and test the classification accuracy of each set. The relative influence on the classification accuracy of the respective spatial, temporal or frequency signatures can then be analysed and useful interpretations can be made. Additionaly, we show that through tensor factorisation we can perform dimensionality reduction by evaluating the classification performance with regards to the number mode components and by rejecting components with insignificant contribution to the classification accuracy

Barriers to Screening for Gestational Diabetes Mellitus in New Zealand Following the Introduction of Universal Screening Recommendations

Background: In 2014 the New Zealand Ministry of Health implemented a universal program of screening for gestational diabetes mellitus (GDM) in pregnancy; however, data suggest that only half of all women are being screening according to the guidelines. This study aimed to explore women's views and experiences of GDM screening and to determine what the main screening barriers are. Methods: Eighteen women were recruited from the Waikato region of New Zealand, who were either pregnant (>28 weeks of gestation) or had given birth in the last 6 months. These women participated in a semi-structured interview about their experience of GDM screening and the transcripts were thematically analyzed. Of these women, 14 had been screened for gestational diabetes (three were screened late) and four had not been screened at all. Results: Multiple barriers to screening for GDM were identified, with two overarching themes of “confusion, concerns, and access to information for screening,” and “challenges to accessing and completing the screening test.” Specific barriers included the preference of risk-based assessments for GDM by their leading health professional (usually a registered midwife); negative perceptions of “sugar drink test”; needing time off work and childcare; travel costs for rural women; previous negative screening experiences; and reduced health literacy. Conclusion: There appear to be both woman-, midwife-, and system-level barriers to screening for GDM. While screening is ultimately a woman's choice, there does appear to be capacity to increase screening rates by improving awareness of the updated guidelines, and making the test environment more accessible and comfortable.fals

SYNtzulu: A Tiny RISC-V-Controlled SNN Processor for Real-Time Sensor Data Analysis on Low-Power FPGAs

Spiking Neural Networks (SNNs) are energy-and performance-efficient tools that have been found to be very useful in AI applications at the edge. This paper introduces SYNtzulu, an SNN processing element designed to be used in low-cost and low-power FPGA devices for near-sensor data analysis. The system is equipped with a RISC-V subsystem responsible for controlling the input/output and setting runtime parameters, thus increasing its flexibility. We evaluated the system, which was implemented on a Lattice iCE40UP5K FPGA, in various use cases employing SNNs with accuracy comparable to the state-of-the-art. SYNtzulu dissipates a maximum power of 12.05 mW when performing SNN inference, which can be reduced to an average of just 1.45 mW through the use of dynamic power management

Endocytotic formation of vesicles and other membranous structures induced by Ca2+ and axolemmal injury

Vesicles and/or other membranous structures that form after axolemmal damage have recently been shown to repair (seal) the axolemma of various nerve axons. To determine the origin of such membranous structures, (1) we internally dialyzed isolated intact squid giant axons (GAs) and showed that elevation of intracellular Ca21 .100 uM produced membranous structures similar to those in axons transected in Ca21-containing physiological saline; (2) we exposed GA axoplasm to Ca21- containing salines and observed that membranous structures did not form after removing the axolemma and glial sheath but did form in severed GAs after .99% of their axoplasm was removed by internal perfusion; (3) we examined transected GAs and crayfish medial giant axons (MGAs) with time-lapse confocal fluorescence microscopy and showed that many injuryinduced vesicles formed by endocytosis of the axolemma; (4) we examined the cut ends of GAs and MGAs with electron microscopy and showed that most membranous structures were single-walled at short (5–15 min) post-transection times, whereas more were double- and multi-walled and of probable glial origin after longer (30–150 min) post-transection times; and (5) we examined differential interference contrast and confocal images and showed that large and small lesions evoked similar injury responses in which barriers to dye diffusion formed amid an accumulation of vesicles and other membranous structures. These and other data suggest that Ca21 inflow at large or small axolemmal lesions induces various membranous structures (including endocytotic vesicles) of glial or axonal origin to form, accumulate, and interact with each other, preformed vesicles, and/or the axolemma to repair the axolemmal damage.This work was supported by grants from National Institutes of Health (NIH; NS31256) and the State of Texas (Advanced Technology 3658-446).Neuroscienc

Gender Effect on Clinical Profiles, Pharmacological Treatments and Prognosis in Patients Hospitalized for Heart Failure

Heart failure (HF) is a significant disease affecting 1-2% of the general population. Despite its general aspects, HF, like other cardiovascular diseases, presents various gender-specific aspects in terms of etiology, hemodynamics, clinical characteristics, therapy, and outcomes. As is well known, HF with preserved ejection fraction more frequently affects females, with diabetes and arterial hypertension representing the most critical determinants of HF. On the other hand, women are traditionally underrepresented in clinical trials and are often considered undertreated. However, it is not clear whether such differences reflect cultural behaviors and clinical inertia or if they indicate different clinical profiles and the impact of sex on hard clinical outcomes. We aimed to review the sex-related differences in patients affected by HF

Precision sketching with de-aging networks in forensics

Addressing the intricacies of facial aging in forensic facial recognition, traditional sketch portraits often fall short in precision. This study introduces a pioneering system that seamlessly integrates a de-aging module and a sketch generator module to overcome the limitations inherent in existing methodologies. The de-aging module utilizes a deepfake-based neural network to rejuvenate facial features, while the sketch generator module leverages a pix2pix-based Generative Adversarial Network (GAN) for the generation of lifelike sketches. Comprehensive evaluations on the CUHK and AR datasets underscore the system’s superior efficiency. Significantly, comprehensive testing reveals marked enhancements in realism during the training process, demonstrated by notable reductions in Frechet Inception Distance (FID) scores (41.7 for CUHK, 60.2 for AR), augmented Structural Similarity Index (SSIM) values (0.789 for CUHK, 0.692 for AR), and improved Peak Signal-to-Noise Ratio (PSNR) metrics (20.26 for CUHK, 19.42 for AR). These findings underscore substantial advancements in the accuracy and reliability of facial recognition applications. Importantly, the system, proficient in handling diverse facial characteristics across gender, race, and culture, produces both composite and hand-drawn sketches, surpassing the capabilities of current state-of-the-art methods. This research emphasizes the transformative potential arising from the integration of de-aging networks with sketch generation, particularly for age-invariant forensic applications, and highlights the ongoing necessity for innovative developments in de-aging technology with broader societal and technological implications

A QoE assessment method based on EDA, heart rate and EEG of a virtual reality assistive technology system.

Conference PaperThe1 key aim of various assistive technology (AT) systems is to augment an individual’s functioning whilst supporting an enhanced quality of life (QoL). In recent times, we have seen the emergence of Virtual Reality (VR) based assistive technology systems made possible by the availability of commercially available Head Mounted Displays (HMDs). The use of VR for AT aims to support levels of interaction and immersion not previously possibly with more traditional AT solutions. Crucial to the success of these technologies is understanding, from the user perspective, the influencing factors that affect the user Quality of Experience (QoE). In addition to the typical QoE metrics, other factors to consider are human behavior like mental and emotional state, posture and gestures. In terms of trying to objectively quantify such factors, there are wide ranges of wearable sensors that are able to monitor physiological signals and provide reliable data. In this demo, we will capture and present the users EEG, heart Rate, EDA and head motion during the use of AT VR application. The prototype is composed of the sensor and presentation systems: for acquisition of biological signals constituted by wearable sensors and the virtual wheelchair simulator that interfaces to a typical LCD display.ye

Hydrogen bonding in water under extreme confinement unveiled by nanoscale vibrational spectroscopy and simulations

Fluids under extreme confinement exhibit distinctly new properties compared to their bulk analogs. Understanding the structure and intermolecular bonding of confined water lays the foundation for creating and improving applications at the water-energy nexus. However, probing confined water experimentally at the length scale of intermolecular and surface forces has remained a challenge. Here, we report a combined experiment/theory framework to reveal changes in H-bonding environment and the underlying molecular structure of confined water inside individual carbon nanotubes. H-bonding is directly probed through the O-H stretch frequency with vibrational electron energy-loss spectroscopy and compared to spectra from molecular-dynamics simulations based on density-functional-theory. Experimental spectra show that water in larger carbon nanotubes exhibit the bonded O-H vibrations of bulk water, but at smaller diameters, the frequency blueshifts to near the 'free' O-H stretch found in water vapor and hydrophobic surfaces. The matching simulations reveal that, in addition to steric confinement, the tube's vibrations play a key role in breaking up the H-bond network, resulting in an orientationally-dispersed, non-H-bonded phase. Furthermore, the temperature-dependence of the vibrations is investigated, providing insights into phase transitions and the confined-water density. This research demonstrates the potential of the experiment/theory framework to explore unprecedented aspects of structure and bonding in confined fluids

Takotsubo syndrome in a Sardinian amyotrophic lateral sclerosis cohort

IntroductionAmyotrophic lateral sclerosis (ALS) is known to be associated with varying degrees of autonomic and cardiovascular dysfunction. Recent case reports showed that ALS may be linked to Takotsubo syndrome (TTS). We assessed the frequency of TTS in an incident ALS cohort from Sardinia, Italy, and investigated the relationship of TTS with ALS course.MethodsWe retrospectively examined a 10-year (2010-2019) incident cohort of ALS patients of Sardinian ancestry, reported TTS frequency and patients' clinical characteristics. Following, we checked for TTS among patients with ALS onset after 2019 and focused on the same features as for the incident cohort.ResultsOur incident cohort included 344 ALS patients and 5 of them (1.45%) developed TTS. All were female and their median onset age was 71.5 years (IQR 62.75-77). Two patients had spinal and three bulbar onset, though all patients had bulbar involvement and were at an advanced stage of disease (ALSFRS <= 25, King's >= 3) at TTS diagnosis. We identified a potential TTS trigger in three patients (hospitalization for PEG placement, pneumonia). Among patients who had ALS onset after 2019, we identified a further TTS case and described it.ConclusionTTS is not a rare condition in ALS. Female sex, bulbar involvement, and later age of disease onset may be important risk factors for developing this cardiac condition and a physical or psychological trigger is often observed. Despite autonomic dysfunction in ALS has been already demonstrated, the precise physiopathological mechanism underlying TTS needs to be further clarified