Length Modulation Research Articles

New tunneling source follower with low 1/f noise and high voltage gain

We have designed a tunneling source follower (TSF) for image sensors that achieves high voltage gain (Av) and low 1/f noise simultaneously. The TSF is composed of N-P-N-N, especially the p-doped grounded area, which serves to amplify the insufficient tunneling current, allowing the source follower (SF) to utilize band-to-band tunneling (BTBT). Compared to thermionic emission, tunneling based structures contribute to increasing Av through lower channel length modulation and lower body effect. As a result, TSF achieves a higher Av (~ 1.0 V/V) than conventional SF (~ 0.9 V/V). Moreover, the n-doped channel makes the buried conductive channel farther from the interface, lowering the noise. The input-referred voltage noise spectral density (SV) is approximately 10 times lower in TSF than that of in conventional SF. Therefore, our TSF can be a possible candidate for High Av and low 1/f noise image sensors.

Fast-scanning speed single-photon counting LiDAR based on front focal length modulation.

This Letter presents a method for fast-scanning speed LiDAR based on front focal length modulation in the transmitter, which compensates for the influence of the laser divergence angle on the scanning speed at close range of the long-range LiDAR. According to the thin lens equation for Gaussian beams, the laser divergence angle is affected by the distance from the lens to the object (the waist of the laser beam). The scanning speed of the LiDAR is correlated to the laser divergence angle during LiDAR operation, and the scanning speed can be improved by expanding the laser divergence angle by enlarging the front focal length of the transmitter. Through experimental analysis, the laser dispersion angle modulation of LiDAR can improve the scanning speed under the premise of guaranteeing the target detection performance in close-range detection.

Developmental responses of roots to limited phosphate availability: research progress and application in cereals.

Phosphorus (P), an essential macronutrient, is crucial for plant growth and development. However, available inorganic phosphate (Pi) is often scarce in soil, and its limited mobility exacerbates P deficiency in plants. Plants have developed complex mechanisms to adapt to Pi-limited soils. The root, the primary interface of the plant with soil, plays an essential role in plant adaptation to Pi-limited soil environments. Root system architecture significantly influences Pi acquisition via the dynamic modulation of primary root and/or crown root length, lateral root proliferation and length, root hair development, and root growth angle in response to Pi availability. This review focuses on the physiological, anatomical, and molecular mechanisms underpinning changes in root development in response to Pi starvation in cereals, mainly focusing on the model monocot plant rice (Oryza sativa). We also review recent efforts to modify root architecture to enhance P uptake efficiency in crops and propose future research directions aimed at the genetic improvement of Pi uptake and use efficiency in crops based on root system architecture.

Boij-Söderberg conjectures for differential modules

Boij-Söderberg theory gives a combinatorial description of the set of Betti tables belonging to finite length modules over the polynomial ring S=k[x1,…,xn]. We posit that a similar combinatorial description can be given for analogous numerical invariants of graded differential S-modules, which are natural generalizations of chain complexes. We prove several results that lend evidence in support of this conjecture, including a categorical pairing between the derived categories of graded differential S-modules and coherent sheaves on Pn−1 and a proof of the conjecture in the case where S=k[t].

Vibration-Induced Sweeping Operation in Fiber Lasers

A new vibration-based mechanism of optical frequency/wavelength sweeping in fiber lasers induced by optical path length modulation of a laser cavity section is proposed. The mechanism is implemented for an erbium-doped fiber ring laser with a saturable absorber. Without the vibrations, the laser generates a single longitudinal mode (SLM) radiation. We show experimentally for the first time that mechanical vibrations of the laser cavity section can lead to mode dynamics in both frequency and time domains. The possibility of obtaining various mode dynamics, such as vibration-induced sweeping in a wavelength range of up to 2.2 nm or SLM generation with periodic mode hopping between two fixed longitudinal modes depending on the pump wavelength, is experimentally shown. In this vibration-based approach, the interval between changes in the laser cavity modes has good stability, because it directly relates to the vibration period.

MicroRNAs role in telomere length maintenance and telomerase activity in tumor cells.

MiRNAs, a class of non-coding RNA molecules, have emerged as critical modulators of telomere length and telomerase activity by finely tuning the expression of target genes (and not gene targets) within signaling pathways involved in telomere homeostasis. The primary objective of this systematic review was to compile and synthesize the existing body of knowledge on the role, association, and involvement of miRNAs in telomere length. Additionally, the review explored the regulation, function, and activation mechanism of thehuman telomerase reverse transcriptase(hTERT) gene and telomerase activity in tumor cells. A comprehensive analysis of 47 selected articles revealed 40 distinct miRNAs involved in these processes. These miRNAs were shown to exert their function, in both clinical cases and cell line models, either directly or indirectly, regulating hTERT and telomerase activity through distinct molecular mechanisms. The regulatory roles of these miRNAs significantly affected major cancer phenotypes, with outcomes largely dependent on the tissue type and the cellular actions within the tumor cells, whereby they functioned as oncogenes or tumor suppressors. These findings strongly support the pivotal role of miRNAs in modulating telomere length and telomerase activity, thereby contributing to the intricate and complex regulation of telomere homeostasis in tumor cells.Moreover, they emphasize the potential of targeting miRNAs and key regulatory genes as therapeutic strategies to disrupt cancer cell growth and promote senescence, offering promising avenues for novel cancer treatments.

Biomimetic Activation of N‐Nitrosamides with Red Light‐Triggered Nitric Oxide Release via Mediated Electron Transfer

Mediated electron transfer (MET) is fundamental to many biological functions, including cellular respiration, photosynthesis, and enzymatic catalysis. However, leveraging the MET process to enable the release of therapeutic gases has been largely unexplored. Herein, we report the bio‐inspired activation of a series of UV‐absorbing N‐nitrosamide derivatives (NOA) under red light exposure, enabling the quantitative release of nitric oxide (NO) gasotransmitter via an MET process. The cornerstone of our design is the covalent linkage of a 2,4‐dinitroaniline moiety, which acts as an electron mediator to the N‐nitrosamide groups. This facilitates efficient electron transfer from the excited palladium(II) meso‐tetraphenyltetrabenzoporphyrin (PdTPTBP) photocatalyst and the selective activation of NOA. Our approach has been validated with distinct photocatalysts and various N‐nitrosamides, including those derived from carbamates, amides, and ureas. Notably, the modulation of the linker length between the electron mediator and N‐nitrosamide groups serves as a regulatory mechanism for controlling NO release kinetics. Moreover, this biomimetic NO release platform demonstrates effective operation under both normoxic and hypoxic conditions, and it enables localized delivery of NO under physiological conditions, exhibiting significant anticancer efficacy within the phototherapeutic window and enhanced selectivity towards tumor cells.

Biomimetic Activation of N-Nitrosamides with Red Light-Triggered Nitric Oxide Release via Mediated Electron Transfer.

Mediated electron transfer (MET) is fundamental to many biological functions, including cellular respiration, photosynthesis, and enzymatic catalysis. However, leveraging the MET process to enable the release of therapeutic gases has been largely unexplored. Herein, we report the bio-inspired activation of a series of UV-absorbing N-nitrosamide derivatives (NOA) under red light exposure, enabling the quantitative release of nitric oxide (NO) gasotransmitter via an MET process. The cornerstone of our design is the covalent linkage of a 2,4-dinitroaniline moiety, which acts as an electron mediator to the N-nitrosamide groups. This facilitates efficient electron transfer from the excited palladium(II) meso-tetraphenyltetrabenzoporphyrin (PdTPTBP) photocatalyst and the selective activation of NOA. Our approach has been validated with distinct photocatalysts and various N-nitrosamides, including those derived from carbamates, amides, and ureas. Notably, the modulation of the linker length between the electron mediator and N-nitrosamide groups serves as a regulatory mechanism for controlling NO release kinetics. Moreover, this biomimetic NO release platform demonstrates effective operation under both normoxic and hypoxic conditions, and it enables localized delivery of NO under physiological conditions, exhibiting significant anticancer efficacy within the phototherapeutic window and enhanced selectivity towards tumor cells.

Programmable delay cell based area efficient time-mode smart temperature sensor exploiting channel length modulation coefficient λ

This work presents an all-digital Programmable Delay Cell (PDC)-based time-domain smart temperature sensor exploiting the channel length modulation coefficient λ. For the first time the work has been described to establish the choice of multimode conversion options in the time-domain architecture of temperature sensor. The sensor incorporates a PDC and a time-to-digital converter (TDC) for the generation of temperature code. The different channel lengths of the PDC and Gated Ring Oscillator (GRO) delay elements of the TDC ensure the precise operation of the sensor. The proposed design provides a novel approach for the generation of variable resolution options having different sampling rates. At 90-nm CMOS process and 1.1 V supply voltage, the sensor occupies 0.015 mm2 and operates over a span of −60 °C to 120 °C. Additionally, multimode conversion time allows the sensor to be tuned to a small value of energy/conversion at 27 °C. This confirms to 0.38 nJ and 3.13 nJ at modes M0 and M7, respectively. Besides the sensor obtains a resolution 0.747 °C and 0.093 °C at a conversion time of 0.669 μs and 5.5 μs, respectively.

Design and dynamic characterization of a phototunable optofluidic lens

Optofluidic devices that dynamically respond to light stimuli have the potential to impart modern adaptive optics with intrinsic optical logic without the need for external power sources or feedback control. While photo actuation is typically associated with low energy efficiency compared with alternative modes of actuation, fluid lenses can be tuned with minimal work by generating small differential pressures across the surface of the lens to drive a change in focal length. In this study, we developed a wide aperture (9.5 mm) photothermally actuated lens that leverages spatially and thermodynamically informed design principles developed for resistively heated thermo-pneumatically actuated lenses. Using experimentally validated models to describe the curvature of pressurized elastomer-bound interfaces, we demonstrated phototunable modulation of the focal length from 124 mm to 90 mm in real time using 233 mW of 405 nm light over 30 s of irradiation with an estimated 8.2 µJ of mechanical work (10−4% efficiency). The initial focal length recovered after 60 s in the dark over three consecutive cycles of actuation. Additionally, the photoactuated response is shown to correlate well with the light intensity.

Canonical and noncanonical roles of Hop1 are crucial for meiotic prophase in the fungus Sordaria macrospora.

We show here that in the fungus Sordaria macrospora, the meiosis-specific HORMA-domain protein Hop1 is not essential for the basic early events of chromosome axis development, recombination initiation, or recombination-mediated homolog coalignment/pairing. In striking contrast, Hop1 plays a critical role at the leptotene/zygotene transition which is defined by transition from pairing to synaptonemal complex (SC) formation. During this transition, Hop1 is required for maintenance of normal axis structure, formation of SC from telomere to telomere, and development of recombination foci. These hop1Δ mutant defects are DSB dependent and require Sme4/Zip1-mediated progression of the interhomolog interaction program, potentially via a pre-SC role. The same phenotype occurs not only in hop1Δ but also in absence of the cohesin Rec8 and in spo76-1, a non-null mutant of cohesin-associated Spo76/Pds5. Thus, Hop1 and cohesins collaborate at this crucial step of meiotic prophase. In addition, analysis of 4 non-null mutants that lack this transition defect reveals that Hop1 also plays important roles in modulation of axis length, homolog-axis juxtaposition, interlock resolution, and spreading of the crossover interference signal. Finally, unexpected variations in crossover density point to the existence of effects that both enhance and limit crossover formation. Links to previously described roles of the protein in other organisms are discussed.

Dual-input robust diagnostics for railway point machines via audio signals

ABSTRACT Railway Point Machine (RPM) is a fundamental component of railway infrastructure and plays a crucial role in ensuring the safe operation of trains. Its primary function is to divert trains from one track to another, enabling connections between different lines and facilitating route selection. By judiciously deploying turnouts, railway systems can provide efficient transportation services while ensuring the safety of passengers and cargo. As signal processing technologies develop rapidly, taking the easy acquisition advantages of audio signals, a fault diagnosis method for RPMs is proposed by considering noise and multi-channel signals. The proposed method consists of several stages. Initially, the signal is subjected to pre-processing steps, including cropping and channel separation. Subsequently, the signal undergoes noise addition using the Random Length and Dynamic Position Noises Superposition (RDS) module, followed by conversion to a greyscale image. To enhance the data, Synthetic Minority Oversampling Technique (SMOTE) module is applied. Finally, the training data is fed into a Dual-input Attention Convolutional Neural Network (DIACNN). By employing various experimental techniques and designing diverse datasets, our proposed method demonstrates excellent robustness and achieves an outstanding classification accuracy of 99.73%.

Sinking rates, orientation, and behavior of pennate diatoms.

Phytoplankton cells are now recognized as dynamic entities rather than as passive and isolated particles because they can actively modulate impacts of selection factors (nutrients, light, turbidity, and mixing) through a wide range of adaptations. Cell shape and/or chain length modulation is one of these processes but has predominantly been studied as an adaptation or an acclimatation to a specific growth limitation (light, nutrients, predation, etc.). In this study we have demonstrated that cell shape and size may have greater roles than previously known in phytoplankton ecology and species adaptation by permitting cell-to-cell signaling and more complex ecological processes that result from it. By exploring microscale biophysical interactions that lead to specific cell reorientation processes, we demonstrated that cell geometry not only modulates cell sinking rates but can also provide fast sensor responses to the cells' environment. Although gyrotaxis has been described in detail for motile phytoplankton cells, our findings illustrate that the reorientation process described here can occur even in non-motile cells within their natural environment. An additional consistent behavior was also recently described for a diatom species (Pseudo-nitzschia delicatessima), and with this study, we extend this observation to Pseudo-nitzschia pungens and Pseudo-nitzschia fraudulenta. Our observations emphasize the generality of this process, which adds a new level of complexity to our understanding of cellular interactions and their network of sensors.

Chirped flicker optoretinography for in vivo characterization of human photoreceptors' frequency response to light.

Flicker electroretinography (ERG) has served as a valuable noninvasive objective tool for investigating retinal physiological function through the measurement of electrical signals originating from retinal neurons in response to temporally modulated light stimulation. Deficits in the response at certain frequencies can be used as effective biomarkers of cone-pathway dysfunction. In this Letter, we present the progress we made on its optical counterpart-photopic flicker optoretinography (f-ORG). Specifically, we focus on the measurement of the response of light-adapted retinal photoreceptors to a flicker stimulus with chirped frequency modulation. In contrast to measurements performed at discrete frequencies, this technique enables a significantly accelerated characterization of photoreceptor outer segment optical path length modulation amplitudes in the nanometer range as a function of stimulus frequency, enabling the acquisition of the characteristic frequency response in less than 2 sec.

Abstract 6477: Modulators of hospital length of stay after intracranial neoplasm excision

Abstract Purpose: Intracranial neoplasms are the leading cause of cancer death among men under 40 years old. A major part of the standard of care is excision of the tumor, but there is a lack of robust large-patient studies of outcomes for these patients. Methods: The Nationwide Inpatient Sample was queried from 2018 to 2020 to identify patients with an intracranial neoplasm. Multivariable linear regression with patient- and hospital-level characteristics as covariates was used to identify factors associated with long hospital stays. Results: From 2018 to 2020, there were 97,795 hospital encounters with a primary diagnosis of an intracranial neoplasm. Of these patients, 64.6% underwent a tumor excision procedure during their hospital visit. The average age of these patients undergoing excision was 57.80.2 years. Most patients were male (58.6%), white (79.1%), private insurance beneficiaries (46.3%), and of the highest income quartile (26.8%). These patients most commonly presented to hospitals in the West (34.9%), with a medium number of beds (36.4%), and presented to rural hospitals (41.7%). The most common locations of these neoplasms were the frontal (29.1%), temporal (21.3%), and parietal (12.1%) lobes. Neoplasms in more than one location in the brain occurred in 4.5% of patients. Multivariable linear regression identified the following factors as significantly associated with longer hospital stays: identifying as Black (beta=2.08; p<0.001), identifying as an Asian or Pacific Islander (beta=1.22; p=0.017), being a Medicaid beneficiary (beta=2.25; p<0.001), and being uninsured (beta=1.63; p<0.001). Having a neoplasm in the cerebral ventricle (beta=4.93; p<0.001), cerebellum (beta=2.81; p<0.001), or brain stem (beta=3.45; p<0.001), and having multiple neoplasms (beta=1.85; p=0.008) were also associated with longer hospital stays. Interestingly, having a parietal (beta=-0.54; p=0.011) or occipital (b=-0.99; p<0.001) lobe neoplasm was associated with shorter hospital stays. Conclusion: Intracranial neoplasms are deadly condition and excision of tumor is a important life-saving treatment option. In this study, we demonstrated that location of neoplasm, race, and insurance status are significant modulators of the length of a hospital stay after surgery. Citation Format: Jayla Hsiung, Kamil Taneja, Lauren Ladehoff, Karan Patel, Eric Toloza. Modulators of hospital length of stay after intracranial neoplasm excision [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6477.

1/f Noise Mitigation in an Opto-Mechanical Sensor with a Fabry-Pérot Interferometer.

Low-frequency and 1/f noise are common measurement limitations that arise in a variety of physical processes. Mitigation methods for these noises are dependent on their source. Here, we present a method for removing 1/f noise of optical origin using a micro-cavity Fabry-Pérot (FP) interferometer. A mechanical modulation of the FP cavity length was applied to a previously studied opto-mechanical sensor. It effectively mimics an up-conversion of the laser frequency, shifting signals to a region where lower white-noise sources dominate and 1/f noise is not present. Demodulation of this signal shifts the results back to the desired frequency range of observation with the reduced noise floor of the higher frequencies. This method was found to improve sensitivities by nearly two orders of magnitude at 1 Hz and eliminated 1/f noise in the range from 1 Hz to 4 kHz. A mathematical model for low-finesse FP cavities is presented to support these results. This study suggests a relatively simple and efficient method for 1/f noise suppression and improving the device sensitivity of systems with an FP interferometer readout.

‘Beware, I am large and dangerous’ – human listeners can be deceived by dynamic manipulation of the indexical content of agonistic dog growls

Dishonest vocal signals about body size are rarely encountered, however, dogs are capable of modifying indexical information in their growls. This apparent acoustic body-size manipulation could be affected by the level of threat experienced by the dog. We tested whether this natural size manipulation actually affects how listeners assess the size of the dog, thus whether it could be considered as a successful indexical information manipulation. We requested human participants to assess dog growls, originally recorded when dogs encountered various ‘threatening strangers’ (of different sex, stature). The participants heard several sets of growl pairs, where they had to guess, which growl belonged to the ‘larger dog’. In the Control condition, dog growls originated from two different dogs in a pair; in the Test condition, growls of the same dog were presented pair by pair, always recorded in the presence of different threatening humans. Human listeners reliably picked the larger dog from two differently sized animals based on their growls alone. In the Test condition, participants thought that the dog was ‘larger’ when it was threatened by a female experimenter, and when the dog was growling at a larger sized human. We found that while growl length modulation was the main factor behind size-choice decisions in the case of female strangers, formant dispersion difference contributed the most when listeners chose which dog was the larger in the case of male opponents. Our results provide firsthand evidence of dogs’ functionally deceptive vocalizations towards humans, a phenomenon which has not been shown before in any interspecific scenario.

Gate Electrode Work Function Engineered Nanowire FET with High Performance and Improved Process Sensitivity

MOSFETs have been used in integrated circuits for a long time. These were replaced by FinFET’s in 2011. But for short-channel devices, FinFET’s have low performance due to various effects like velocity saturation, hot carrier effect, drain-induced barrier lowering, channel length modulation, fringing field effect, sub-threshold conduction, threshold voltage roll-off, etc. Gate All Around FET (GAA FET) is the best device that will replace the FinFET’s. Therefore, during the fabrication process, it is crucial to investigate the effects of process variations caused by changes in device dimensions. This research discusses the performance of the proposed device due to process variations. The effect of changes in radius, gate oxide thickness, gate length, and channel doping on GAA FET has been discussed in detail.

Modulation of neuronal morphology by antipsychotic drug: Involvement of serotonin receptor 7

Antipsychotic drugs (APDs) are the primary pharmacological treatment for schizophrenia, a complex disorder characterized by altered neuronal connectivity. Atypical or second-generation antipsychotics, such as Risperidone (RSP) and Clozapine (CZP) predominantly block dopaminergic D2 and serotonin receptor 2A (5-HT2A) neurotransmission. Both compounds also exhibit affinity for the 5-HT7R, with RSP acting as an antagonist and CZP as an inverse agonist. Our study aimed to determine whether RSP and CZP can influence neuronal morphology through a 5-HT7R-mediated mechanism. Here, we demonstrated that CZP promotes neurite outgrowth of early postnatal cortical neurons, and the 5-HT7R mediates its effect. Conversely, RSP leads to a reduction of neurite length of early postnatal cortical neurons, in a 5-HT7R-independent way.Furthermore, we found that the effects of CZP, mediated by 5-HT7R activation, require the participation of ERK and Cdk5 kinase pathways. At the same time, the modulation of neurite length by RSP does not involve these pathways.In conclusion, our findings provide valuable insights into the morphological changes induced by these two APDs in neurons and elucidate some of the associated molecular pathways. Investigating the 5-HT7R-dependent signaling pathways underlying the neuronal morphogenic effects of APDs may contribute to the identification of novel targets for the treatment of schizophrenia.

Koszul modules with vanishing resonance in algebraic geometry

We discuss various applications of a uniform vanishing result for the graded components of the finite length Koszul module associated to a subspace K⊆⋀2V\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K\\subseteq \\bigwedge ^2 V$$\\end{document}, where V is a vector space. Previously Koszul modules of finite length have been used to give a proof of Green’s Conjecture on syzygies of generic canonical curves. We now give applications to effective stabilization of cohomology of thickenings of algebraic varieties, divisors on moduli spaces of curves, enumerative geometry of curves on K3 surfaces and to skew-symmetric degeneracy loci. We also show that the instability of sufficiently positive rank 2 vector bundles on curves is governed by resonance and give a splitting criterion.