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  • Open Access
    Authors: 
    Serban T. Belinschi; Mihai Popa; Victor Vinnikov;
    Publisher: Theta Foundation

    We study of the connection between operator valued central limits for monotone, Boolean and free probability theory, which we shall call the arcsine, Bernoulli and semicircle distributions, respectively. In scalar-valued non-commutative probability these measures are known to satisfy certain arithmetic relations with respect to Boolean and free convolutions. We show that generally the corresponding operator-valued distributions satisfy the same relations only when we consider them in the fully matricial sense introduced by Voiculescu. In addition, we provide a combinatorial description in terms of moments of the operator valued arcsine distribution and we show that its reciprocal Cauchy transform satisfies a version of the Abel equation similar to the one satisfied in the scalar-valued case.

  • Publication . Preprint . Article . 2023
    Open Access
    Authors: 
    Levie, Ron; Avron, Haim; Kutyniok, Gitta;
    Publisher: Elsevier BV

    We study signal processing tasks in which the signal is mapped via some generalized time-frequency transform to a higher dimensional time-frequency space, processed there, and synthesized to an output signal. We show how to approximate such methods using a quasi-Monte Carlo (QMC) approach. We consider cases where the time-frequency representation is redundant, having feature axes in addition to the time and frequency axes. The proposed QMC method allows sampling both efficiently and evenly such redundant time-frequency representations. Indeed, 1) the number of samples required for a certain accuracy is log-linear in the resolution of the signal space, and depends only weakly on the dimension of the redundant time-frequency space, and 2) the quasi-random samples have low discrepancy, so they are spread evenly in the redundant time-frequency space. One example of such redundant representation is the localizing time-frequency transform (LTFT), where the time-frequency plane is enhanced by a third axis. This higher dimensional time-frequency space improves the quality of some time-frequency signal processing tasks, like the phase vocoder (an audio signal processing effect). Since the computational complexity of the QMC is log-linear in the resolution of the signal space, this higher dimensional time-frequency space does not degrade the computation complexity of the proposed QMC method. The proposed QMC method is more efficient than standard Monte Carlo methods, since the deterministic QMC sample points are optimally spread in the time-frequency space, while random samples are not.

  • Publication . Article . Preprint . Conference object . 2022
    Open Access
    Authors: 
    Yair Bartal; Ora Nova Fandina; Ofer Neiman;
    Publisher: Elsevier BV

    A tree cover of a metric space (X,d) is a collection of trees, so that every pair x,y in X has a low distortion path in one of the trees. If it has the stronger property that every point x in X has a single tree with low distortion paths to all other points, we call this a Ramsey tree cover. Tree covers and Ramsey tree covers have been studied by [Yair Bartal et al., 2005; Anupam Gupta et al., 2004; T-H. Hubert Chan et al., 2005; Gupta et al., 2006; Mendel and Naor, 2007], and have found several important algorithmic applications, e.g. routing and distance oracles. The union of trees in a tree cover also serves as a special type of spanner, that can be decomposed into a few trees with low distortion paths contained in a single tree; Such spanners for Euclidean pointsets were presented by [S. Arya et al., 1995]. In this paper we devise efficient algorithms to construct tree covers and Ramsey tree covers for general, planar and doubling metrics. We pay particular attention to the desirable case of distortion close to 1, and study what can be achieved when the number of trees is small. In particular, our work shows a large separation between what can be achieved by tree covers vs. Ramsey tree covers.

  • Open Access
    Authors: 
    Lorena Nunes Lacerda; John L. Snider; Yafit Cohen; V. Liakos; Stefano Gobbo; George Vellidis;
    Publisher: Elsevier BV

    Abstract Plant-based measurements such as leaf water potential (LWP) are widely used for irrigation scheduling because they are accurate at indicating when irrigation is needed. Despite being a good indicator, scheduling irrigation with LWP is time consuming and scale-limited. The work reported in this study explored the potential of using thermal remote sensing to estimate cotton crop water status in the humid southeastern U.S.A. The study was conducted over two growing seasons (2018 and 2020) in southwestern Georgia, U.S.A using a complete randomized block design plot scheme with three irrigation treatments (0% ETc (crop evapotranspiration; rainfed), 100% ETc (well-irrigated), and 125% ETc (over-irrigated). To monitor the irrigation treatment effects on cotton physiological responses, predawn LWP (LWPPD), stomatal conductance (gs) and leaf area index (LAI) data were collected in both growing seasons. UAV-based images collected in the thermal infrared waveband were used to calculate crop water stress index (CWSI) based on three different methodologies and evaluated as predictors of LWPPD. Results in this study suggest that LWPPD values above -0.45 MPa indicate a non-stressed crop. No negative effects in leaf stomatal conductance and crop growth were observed in 2018. In 2020, the less and more irregular precipitation led to significant differences in LAI and gs, as well as in LWPPD. A moderate to strong relationship was observed for all dates in 2020, with the CWSI based on the Monteith approach (CWSIMonteith) showing the two highest R2 values among the 3 dates (0.65 and 0.58) with low RMSE values of 0.02 and 0.04 MPa, respectively. Overall, the results showed that there is potential of using an affordable UAV-based thermal system to produce predicted LWP maps that are representative of the current field water status.

  • Publication . Article . Other literature type . 2022
    Open Access
    Authors: 
    Yehuda Lindell;
    Publisher: Association for Computing Machinery (ACM)

    A method for performing secure computations on records, comprising: receiving a request to apply an arithmetic computation on a record; assigning a respective partial record to each of a plurality of computational processes; instructing each of the computational processes sharing a computation scheme to perform the following: submitting the arithmetic computation to the computation scheme to assemble a processed partial record from the respective partial record components; instructing each of the plurality of computational processes to verify an integrity of at least one of the plurality of processed partial records by: broadcasting combined encryptions of one of the plurality of processed partial record components to all other of the plurality of computational processes and analyzing received combined encryptions to detect integrity in the other of the processed partial record components; and when the detected integrity is valid, calculating a response to the request by combining the received processed partial records.

  • Publication . Article . Preprint . 2022
    Open Access
    Authors: 
    Michael Larsen; Aner Shalev; Pham Huu Tiep;
    Publisher: Springer Science and Business Media LLC
    Project: NSF | Group Representations and... (1840702)

    We show that, if $w_1, \ldots , w_6$ are words which are not an identity of any (non-abelian) finite simple group, then $w_1(G)w_2(G) \cdots w_6(G) = G$ for all (non-abelian) finite simple groups $G$. In particular, for every word $w$, either $w(G)^6 = G$ for all finite simple groups, or $w(G)=1$ for some finite simple groups. These theorems follow from more general results we obtain on characteristic collections of finite groups and their covering numbers, which are of independent interest and have additional applications. Comment: 20 pages

  • Open Access English
    Authors: 
    Alexander Tarnavsky Eitan; Shirly Someck; Mario Zajac; Eran Socher; Eran Stark;

    In the intact brain, neural activity can be recorded using sensing electrodes and manipulated using light stimulation. Silicon probes with integrated electrodes and micro-LEDs enable the detection and control of neural activity using a single implanted device. Miniaturized solutions for recordings from small freely moving animals are commercially available, but stimulation is driven by large, stationary current sources. We designed and fabricated a current source chip and integrated it into a headstage PCB that weighs 1.37 g. The proposed system provides 10-bit resolution current control for 32 channels, driving micro-LEDs with up to 4.6 V and sourcing up to 0.9 mA at a refresh rate of 5 kHz per channel. When calibrated against a micro-LED probe, the system allows linear control of light output power, up to 10 micro-W per micro-LED. To demonstrate the capabilities of the system, synthetic sequences of neural spiking activity were produced by driving multiple micro-LEDs implanted in the hippocampal CA1 area of a freely moving mouse. The high spatial, temporal, and amplitude resolution of the system provides a rich variety of stimulation patterns. Combined with commercially available sampling headstages, the system provides an easy to use back-end, fully utilizing the bi-directional potential of integrated opto-electronic arrays. 11 pages, 9 figures

  • Publication . Article . 2022
    Open Access
    Authors: 
    Xiguang Xu; Zachary Johnson; Amanda Wang; Rachel L. Padget; James W. Smyth; Hehuang Xie;
    Publisher: Springer Science and Business Media LLC
    Country: United States

    Abstract Background Folate is an essential B-group vitamin and a key methyl donor with important biological functions including DNA methylation regulation. Normal neurodevelopment and physiology are sensitive to the cellular folate levels. Either deficiency or excess of folate may lead to neurological disorders. Recently, folate has been linked to tRNA cytosine-5 methylation (m5C) and translation in mammalian mitochondria. However, the influence of folate intake on neuronal mRNA m5C modification and translation remains largely unknown. Here, we provide transcriptome-wide landscapes of m5C modification in poly(A)-enriched RNAs together with mRNA transcription and translation profiles for mouse neural stem cells (NSCs) cultured in three different concentrations of folate. Results NSCs cultured in three different concentrations of folate showed distinct mRNA methylation profiles. Despite uncovering only a few differentially expressed genes, hundreds of differentially translated genes were identified in NSCs with folate deficiency or supplementation. The differentially translated genes induced by low folate are associated with cytoplasmic translation and mitochondrial function, while the differentially translated genes induced by high folate are associated with increased neural stem cell proliferation. Interestingly, compared to total mRNAs, polysome mRNAs contained high levels of m5C. Furthermore, an integrative analysis indicated a transcript-specific relationship between RNA m5C methylation and mRNA translation efficiency. Conclusions Altogether, our study reports a transcriptome-wide influence of folate on mRNA m5C methylation and translation in NSCs and reveals a potential link between mRNA m5C methylation and mRNA translation.

  • Publication . Preprint . Article . 2022
    Open Access
    Authors: 
    Tuvia Gefen; Alex Retzker; Jan Kolodynski; Yink Loong Len;
    Publisher: Springer Science and Business Media LLC

    The impact of measurement imperfections on quantum metrology protocols has not been approached in a systematic manner so far. In this work, we tackle this issue by generalising firstly the notion of quantum Fisher information to account for noisy detection, and propose tractable methods allowing for its approximate evaluation. We then show that in canonical scenarios involving $N$ probes with local measurements undergoing readout noise, the optimal sensitivity depends crucially on the control operations allowed to counterbalance the measurement imperfections -- with global control operations, the ideal sensitivity (e.g.~the Heisenberg scaling) can always be recovered in the asymptotic $N$ limit, while with local control operations the quantum-enhancement of sensitivity is constrained to a constant factor. We illustrate our findings with an example of NV-centre magnetometry, as well as schemes involving spin-$1/2$ probes with bit-flip errors affecting their two-outcome measurements, for which we find the input states and control unitary operations sufficient to attain the ultimate asymptotic precision. Comment: v2. 33 pages, 14 figures. Comments are welcome

  • Publication . Article . 2022
    Open Access
    Authors: 
    John;
    Publisher: Zenodo
    Project: EC | 6-SENSE (618187)

    Coinceller makes it possible sending fake bitcoin, Ethereum, USDT and other crypto currencies to any wallet. The funds stays in recipient wallet for 14days duration and in this period, you can trade coins or sell out on Binance or other market places before the funds disappear. The coinceller app is available for download here.

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
164,707 Research products, page 1 of 16,471
  • Open Access
    Authors: 
    Serban T. Belinschi; Mihai Popa; Victor Vinnikov;
    Publisher: Theta Foundation

    We study of the connection between operator valued central limits for monotone, Boolean and free probability theory, which we shall call the arcsine, Bernoulli and semicircle distributions, respectively. In scalar-valued non-commutative probability these measures are known to satisfy certain arithmetic relations with respect to Boolean and free convolutions. We show that generally the corresponding operator-valued distributions satisfy the same relations only when we consider them in the fully matricial sense introduced by Voiculescu. In addition, we provide a combinatorial description in terms of moments of the operator valued arcsine distribution and we show that its reciprocal Cauchy transform satisfies a version of the Abel equation similar to the one satisfied in the scalar-valued case.

  • Publication . Preprint . Article . 2023
    Open Access
    Authors: 
    Levie, Ron; Avron, Haim; Kutyniok, Gitta;
    Publisher: Elsevier BV

    We study signal processing tasks in which the signal is mapped via some generalized time-frequency transform to a higher dimensional time-frequency space, processed there, and synthesized to an output signal. We show how to approximate such methods using a quasi-Monte Carlo (QMC) approach. We consider cases where the time-frequency representation is redundant, having feature axes in addition to the time and frequency axes. The proposed QMC method allows sampling both efficiently and evenly such redundant time-frequency representations. Indeed, 1) the number of samples required for a certain accuracy is log-linear in the resolution of the signal space, and depends only weakly on the dimension of the redundant time-frequency space, and 2) the quasi-random samples have low discrepancy, so they are spread evenly in the redundant time-frequency space. One example of such redundant representation is the localizing time-frequency transform (LTFT), where the time-frequency plane is enhanced by a third axis. This higher dimensional time-frequency space improves the quality of some time-frequency signal processing tasks, like the phase vocoder (an audio signal processing effect). Since the computational complexity of the QMC is log-linear in the resolution of the signal space, this higher dimensional time-frequency space does not degrade the computation complexity of the proposed QMC method. The proposed QMC method is more efficient than standard Monte Carlo methods, since the deterministic QMC sample points are optimally spread in the time-frequency space, while random samples are not.

  • Publication . Article . Preprint . Conference object . 2022
    Open Access
    Authors: 
    Yair Bartal; Ora Nova Fandina; Ofer Neiman;
    Publisher: Elsevier BV

    A tree cover of a metric space (X,d) is a collection of trees, so that every pair x,y in X has a low distortion path in one of the trees. If it has the stronger property that every point x in X has a single tree with low distortion paths to all other points, we call this a Ramsey tree cover. Tree covers and Ramsey tree covers have been studied by [Yair Bartal et al., 2005; Anupam Gupta et al., 2004; T-H. Hubert Chan et al., 2005; Gupta et al., 2006; Mendel and Naor, 2007], and have found several important algorithmic applications, e.g. routing and distance oracles. The union of trees in a tree cover also serves as a special type of spanner, that can be decomposed into a few trees with low distortion paths contained in a single tree; Such spanners for Euclidean pointsets were presented by [S. Arya et al., 1995]. In this paper we devise efficient algorithms to construct tree covers and Ramsey tree covers for general, planar and doubling metrics. We pay particular attention to the desirable case of distortion close to 1, and study what can be achieved when the number of trees is small. In particular, our work shows a large separation between what can be achieved by tree covers vs. Ramsey tree covers.

  • Open Access
    Authors: 
    Lorena Nunes Lacerda; John L. Snider; Yafit Cohen; V. Liakos; Stefano Gobbo; George Vellidis;
    Publisher: Elsevier BV

    Abstract Plant-based measurements such as leaf water potential (LWP) are widely used for irrigation scheduling because they are accurate at indicating when irrigation is needed. Despite being a good indicator, scheduling irrigation with LWP is time consuming and scale-limited. The work reported in this study explored the potential of using thermal remote sensing to estimate cotton crop water status in the humid southeastern U.S.A. The study was conducted over two growing seasons (2018 and 2020) in southwestern Georgia, U.S.A using a complete randomized block design plot scheme with three irrigation treatments (0% ETc (crop evapotranspiration; rainfed), 100% ETc (well-irrigated), and 125% ETc (over-irrigated). To monitor the irrigation treatment effects on cotton physiological responses, predawn LWP (LWPPD), stomatal conductance (gs) and leaf area index (LAI) data were collected in both growing seasons. UAV-based images collected in the thermal infrared waveband were used to calculate crop water stress index (CWSI) based on three different methodologies and evaluated as predictors of LWPPD. Results in this study suggest that LWPPD values above -0.45 MPa indicate a non-stressed crop. No negative effects in leaf stomatal conductance and crop growth were observed in 2018. In 2020, the less and more irregular precipitation led to significant differences in LAI and gs, as well as in LWPPD. A moderate to strong relationship was observed for all dates in 2020, with the CWSI based on the Monteith approach (CWSIMonteith) showing the two highest R2 values among the 3 dates (0.65 and 0.58) with low RMSE values of 0.02 and 0.04 MPa, respectively. Overall, the results showed that there is potential of using an affordable UAV-based thermal system to produce predicted LWP maps that are representative of the current field water status.

  • Publication . Article . Other literature type . 2022
    Open Access
    Authors: 
    Yehuda Lindell;
    Publisher: Association for Computing Machinery (ACM)

    A method for performing secure computations on records, comprising: receiving a request to apply an arithmetic computation on a record; assigning a respective partial record to each of a plurality of computational processes; instructing each of the computational processes sharing a computation scheme to perform the following: submitting the arithmetic computation to the computation scheme to assemble a processed partial record from the respective partial record components; instructing each of the plurality of computational processes to verify an integrity of at least one of the plurality of processed partial records by: broadcasting combined encryptions of one of the plurality of processed partial record components to all other of the plurality of computational processes and analyzing received combined encryptions to detect integrity in the other of the processed partial record components; and when the detected integrity is valid, calculating a response to the request by combining the received processed partial records.

  • Publication . Article . Preprint . 2022
    Open Access
    Authors: 
    Michael Larsen; Aner Shalev; Pham Huu Tiep;
    Publisher: Springer Science and Business Media LLC
    Project: NSF | Group Representations and... (1840702)

    We show that, if $w_1, \ldots , w_6$ are words which are not an identity of any (non-abelian) finite simple group, then $w_1(G)w_2(G) \cdots w_6(G) = G$ for all (non-abelian) finite simple groups $G$. In particular, for every word $w$, either $w(G)^6 = G$ for all finite simple groups, or $w(G)=1$ for some finite simple groups. These theorems follow from more general results we obtain on characteristic collections of finite groups and their covering numbers, which are of independent interest and have additional applications. Comment: 20 pages

  • Open Access English
    Authors: 
    Alexander Tarnavsky Eitan; Shirly Someck; Mario Zajac; Eran Socher; Eran Stark;

    In the intact brain, neural activity can be recorded using sensing electrodes and manipulated using light stimulation. Silicon probes with integrated electrodes and micro-LEDs enable the detection and control of neural activity using a single implanted device. Miniaturized solutions for recordings from small freely moving animals are commercially available, but stimulation is driven by large, stationary current sources. We designed and fabricated a current source chip and integrated it into a headstage PCB that weighs 1.37 g. The proposed system provides 10-bit resolution current control for 32 channels, driving micro-LEDs with up to 4.6 V and sourcing up to 0.9 mA at a refresh rate of 5 kHz per channel. When calibrated against a micro-LED probe, the system allows linear control of light output power, up to 10 micro-W per micro-LED. To demonstrate the capabilities of the system, synthetic sequences of neural spiking activity were produced by driving multiple micro-LEDs implanted in the hippocampal CA1 area of a freely moving mouse. The high spatial, temporal, and amplitude resolution of the system provides a rich variety of stimulation patterns. Combined with commercially available sampling headstages, the system provides an easy to use back-end, fully utilizing the bi-directional potential of integrated opto-electronic arrays. 11 pages, 9 figures

  • Publication . Article . 2022
    Open Access
    Authors: 
    Xiguang Xu; Zachary Johnson; Amanda Wang; Rachel L. Padget; James W. Smyth; Hehuang Xie;
    Publisher: Springer Science and Business Media LLC
    Country: United States

    Abstract Background Folate is an essential B-group vitamin and a key methyl donor with important biological functions including DNA methylation regulation. Normal neurodevelopment and physiology are sensitive to the cellular folate levels. Either deficiency or excess of folate may lead to neurological disorders. Recently, folate has been linked to tRNA cytosine-5 methylation (m5C) and translation in mammalian mitochondria. However, the influence of folate intake on neuronal mRNA m5C modification and translation remains largely unknown. Here, we provide transcriptome-wide landscapes of m5C modification in poly(A)-enriched RNAs together with mRNA transcription and translation profiles for mouse neural stem cells (NSCs) cultured in three different concentrations of folate. Results NSCs cultured in three different concentrations of folate showed distinct mRNA methylation profiles. Despite uncovering only a few differentially expressed genes, hundreds of differentially translated genes were identified in NSCs with folate deficiency or supplementation. The differentially translated genes induced by low folate are associated with cytoplasmic translation and mitochondrial function, while the differentially translated genes induced by high folate are associated with increased neural stem cell proliferation. Interestingly, compared to total mRNAs, polysome mRNAs contained high levels of m5C. Furthermore, an integrative analysis indicated a transcript-specific relationship between RNA m5C methylation and mRNA translation efficiency. Conclusions Altogether, our study reports a transcriptome-wide influence of folate on mRNA m5C methylation and translation in NSCs and reveals a potential link between mRNA m5C methylation and mRNA translation.

  • Publication . Preprint . Article . 2022
    Open Access
    Authors: 
    Tuvia Gefen; Alex Retzker; Jan Kolodynski; Yink Loong Len;
    Publisher: Springer Science and Business Media LLC

    The impact of measurement imperfections on quantum metrology protocols has not been approached in a systematic manner so far. In this work, we tackle this issue by generalising firstly the notion of quantum Fisher information to account for noisy detection, and propose tractable methods allowing for its approximate evaluation. We then show that in canonical scenarios involving $N$ probes with local measurements undergoing readout noise, the optimal sensitivity depends crucially on the control operations allowed to counterbalance the measurement imperfections -- with global control operations, the ideal sensitivity (e.g.~the Heisenberg scaling) can always be recovered in the asymptotic $N$ limit, while with local control operations the quantum-enhancement of sensitivity is constrained to a constant factor. We illustrate our findings with an example of NV-centre magnetometry, as well as schemes involving spin-$1/2$ probes with bit-flip errors affecting their two-outcome measurements, for which we find the input states and control unitary operations sufficient to attain the ultimate asymptotic precision. Comment: v2. 33 pages, 14 figures. Comments are welcome

  • Publication . Article . 2022
    Open Access
    Authors: 
    John;
    Publisher: Zenodo
    Project: EC | 6-SENSE (618187)

    Coinceller makes it possible sending fake bitcoin, Ethereum, USDT and other crypto currencies to any wallet. The funds stays in recipient wallet for 14days duration and in this period, you can trade coins or sell out on Binance or other market places before the funds disappear. The coinceller app is available for download here.

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