Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Complete Remission Status before Autologous Stem Cell Transplantation Is an Important Prognostic Factor in Patients with Multiple Myeloma Undergoing Upfront Single Autologous Transplantation

Upfront high-dose myeloablative chemotherapy followed by a single autologous stem cell transplantation (ASCT) is the standard therapy for patients under the age of 65 years with newly diagnosed multiple myeloma (MM). Because disease status after induction chemotherapy is variable, we evaluated the prognostic effect of disease status before ASCT especially in patients who were initially chemosensitive. We retrospectively analyzed the initially chemosensitive MM patients (>= partial remission [PR]) enrolled in the Korean Multiple Myeloma Working Party Web-based registration system (www.myeloma.or.kr), Between November 1996 and January 2007, 197 MM patients (median age 53 years) were treated with induction chemotherapy followed by a single ASCT All patients received peripheral blood stem cell (PBSC) support after conditioning with mel-Phalan (Mel) alone. We considered those patients with no detectable M-protein regardless of the result of immunofixation to be in complete remission (CR) in this study. The median follow-up times were 29.2 months (range, 5.4 to 103.8 months) from the day of diagnosis and 22.4 months (range, 0.4 to 96.0 months) from the day of ASCT Before ASCT, 63 patients (32%) were in CR and 134 (68%) were in partial remission (PR). The patients in CR had significantly longer overall survival (OS) from the day of ASCT compared with those in PR (P = .0015). Among the patients who received induction chemotherapy with vincristine, adriamycin, and dexamethasone (n = 162), the same difference in OS was seen between those in CR and those in PR before ASCT (P = .0016). CR after ASCT also predicted longer OS (P = .0135); however, patients with continued CR after ASCT had significantly higher OS after ASCT compared with patient with induced CR after ASCT who were in PR before ASCT (P = .0178). Multivariate analysis indicated that remission status pre-ASCT (CR vs PR) is a significant prognostic factor for predicting OS after ASCT (P = .012, Cox proportional hazard analysis; odds ratio = 2.83; 95% confidence interval = 1.25 to 6.37). We conclude that patients with MM who are in CR before ASCT have a better OS than those in PR before ASCT Continued CR after ASCT may be an important prognostic factor as well. Our findings suggest that the development of more effective induction regimens, including novel antimyeloma agents to improve initial response, should be pursued to enhance clinical benefits post-ASCT.Ludwig H, 2008, BLOOD, V111, P4039, DOI 10.1182/blood-2007-03-081018Kyle RA, 2008, BLOOD, V111, P2962Kumar SK, 2008, BLOOD, V111, P2516, DOI 10.1182/blood-2007-10-116129Brenner H, 2008, BLOOD, V111, P2521, DOI 10.1182/blood-2007-08-104984Mehta J, 2007, BONE MARROW TRANSPL, V40, P1101, DOI 10.1038/sj.bmt.1705799Lacy MQ, 2007, MAYO CLIN PROC, V82, P1179HAROUSSEAU JL, 2007, BLOOD, V110, P139CAVO M, 2007, BLOOD, V110, P30Harousseau JL, 2006, HAEMATOL-HEMATOL J, V91, P1498Barlogie B, 2006, BRIT J HAEMATOL, V135, P158, DOI 10.1111/j.1365-2141.2006.06271.xKim H, 2006, BIOL BLOOD MARROW TR, V12, P837, DOI 10.1016/j.bbmt.2006.04.006O`Shea D, 2006, BONE MARROW TRANSPL, V37, P731, DOI 10.1038/sj.bmt.1705307Rajkumar SV, 2006, J CLIN ONCOL, V24, P431, DOI 10.1200/JCO.2005.03.0221Hari P, 2006, BONE MARROW TRANSPL, V37, P1, DOI 10.1038/sj.bmt.1705194Cavo M, 2005, BLOOD, V106, P35Greipp PR, 2005, J CLIN ONCOL, V23, P3412, DOI 10.1200/JCO.2005.04.242Kyle RA, 2004, NEW ENGL J MED, V351, P1860Kumar S, 2004, BONE MARROW TRANSPL, V34, P161, DOI 10.1038/sj.bmt.1704545TRICOT G, 2004, BLOOD, V104, P936Attal M, 2003, NEW ENGL J MED, V349, P2495Singhal S, 2002, BONE MARROW TRANSPL, V30, P673, DOI 10.1038/sj.bmt.1703717BLADE J, 1998, BRIT J HAEMATOL, V102, P1115Barlogie B, 1997, BLOOD, V89, P789

A Low-Power Analog Processor-in-Memory-Based Convolutional Neural Network for Biosensor Applications

This paper presents an on-chip implementation of an analog processor-in-memory (PIM)-based convolutional neural network (CNN) in a biosensor. The operator was designed with low power to implement CNN as an on-chip device on the biosensor, which consists of plates of 32 × 32 material. In this paper, 10T SRAM-based analog PIM, which performs multiple and average (MAV) operations with multiplication and accumulation (MAC), is used as a filter to implement CNN at low power. PIM proceeds with MAV operations, with feature extraction as a filter, using an analog method. To prepare the input feature, an input matrix is formed by scanning a 32 × 32 biosensor based on a digital controller operating at 32 MHz frequency. Memory reuse techniques were applied to the analog SRAM filter, which is the core of low power implementation, and in order to accurately grasp the MAC operational efficiency and classification, we modeled and trained numerous input features based on biosignal data, confirming the classification. When the learned weight data was input, 19 mW of power was consumed during analog-based MAC operation. The implementation showed an energy efficiency of 5.38 TOPS/W and was differentiated through the implementation of 8 bits of high resolution in the 180 nm CMOS process