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Benthic storms are episodes of strong bottom currents and sediment resuspension that occur at abyssal depths in the ocean. They are often observed in regions with strong, eddying surface currents, such as the western North Atlantic and the Argentine Basin. Deep cyclonic and anticyclonic eddies induced by surface current instabilities have been postulated to accelerate abyssal currents and generate benthic storms. Here, using a primitive-equation model with high vertical resolution, we conduct idealized numerical experiments of the unforced instability of a surface-concentrated, eastward-flowing jet in a zonal channel. We find that the jet, initially in strict thermal wind balance, becomes spontaneously unstable as a result of baroclinic instability, meanders, and eventually develops a complex eddy field with regions of strong ageostrophic flow. Associated with jet meandering, a train of cyclonic and anticyclonic eddies form along the jet and migrate in the same direction as the parent current but much slower. These eddies extend over the whole water column (4000 m depth), consistent with the tendency for eddy barotropization in geostrophic turbulence. They accelerate bottom currents, which are found to be more vigorous in a flat channel than in a channel with a meridional bottom slope. Over the course of the numerical integrations, bottom mixed layers with quasi-uniform potential temperature develop at various locations in the channel. These layers have thicknesses of O(100) m on a flat bottom and O(10) m on a sloping bottom. Our study yields preliminary insights into the fundamental role of surface current instabilities on near-bottom processes, calling for further investigations on downward energy transfer and near-bottom dissipation.

The oceanic bottom mixed layer (BML) is a well mixed, weakly stratified, turbulent boundary layer. Adjacent to the seabed, the BML is of intrinsic importance for studying ocean mixing, energy dissipation, particle cycling and sediment-water interactions. While deep-seabed mining of polymetallic nodules is anticipated to commence in the Clarion-Clipperton Zone (CCZ) of the northeastern tropical Pacific Ocean, knowledge gaps regarding the form of the BML and its potentially key influence on the dispersal of sediment plumes generated by deep-seabed mining activities are yet to be addressed. Here, we report recent field observations from the German mining licence area in the CCZ that characterise the structure and variability of the BML locally. Quasi-uniform profiles of potential temperature extending from the seafloor reveal the presence of a spatially and temporally variable BML with an average local thickness of approximately 250 m. Deep horizontal currents in the region have a mean speed of 3.5 cm s$$^{-1}$$ - 1 and a maximum speed of 12 cm s$$^{-1}$$ - 1 at 18.63 ms above bottom over an 11 month record. The near-bottom currents initially have a net southeastward flow, followed by westward and southward flows with the development of complex, anticyclonic flow patterns. Theoretical predictions and historical data show broad consistency with mean BML thickness but cannot explain the observed heterogeneity of local BML thickness. We postulate that deep pressure anomalies induced by passing surface mesoscale eddies and abyssal thermal fronts could affect BML thickness, in addition to local topographic effects. A simplified transport model is then used to study the influence of the BML on the interplay between turbulent diffusion and sediment settling in the transport of deep-seabed mining induced sediment plumes. Over a range of realistic parameter values, the effects of BML on plume evolution can vary significantly, highlighting that resolving the BML will be a crucial step for accurate numerical modelling of plume dispersal.

Mitotically stable random monoallelic gene expression (RME) is documented for a small percentage of autosomal genes. We developed an in vivo genetic model to study the role of enhancers in RME using high-resolution single-cell analysis of natural killer (NK) cell receptor gene expression and enhancer deletions in the mouse germline. Enhancers of the RME NK receptor genes were accessible and enriched in H3K27ac on silent and active alleles alike in cells sorted according to allelic expression status, suggesting enhancer activation and gene expression status can be decoupled. In genes with multiple enhancers, enhancer deletion reduced gene expression frequency, in one instance converting the universally expressed gene encoding NKG2D into an RME gene, recapitulating all aspects of natural RME including mitotic stability of both the active and silent states. The results support the binary model of enhancer action, and suggest that RME is a consequence of general properties of gene regulation by enhancers rather than an RME-specific epigenetic program. Therefore, many and perhaps all genes may be subject to some degree of RME. Surprisingly, this was borne out by analysis of several genes that define different major hematopoietic lineages, that were previously thought to be universally expressed within those lineages: the genes encoding NKG2D, CD45, CD8α, and Thy-1. We propose that intrinsically probabilistic gene allele regulation is a general property of enhancer-controlled gene expression, with previously documented RME representing an extreme on a broad continuum.

MicroRNAs (miRNAs) are a class of small noncoding RNAs about 22-nucleotide (nt) in length that collectively regulate more than 60% of coding genes. Aberrant miRNA expression is associated with numerous diseases, including cancer. miRNA biogenesis is licenced by the ribonuclease (RNase) III enzyme Drosha, the regulation of which is critical in determining miRNA levels. We and others have previously revealed that alternative splicing regulates the subcellular localization of Drosha. To further investigate the alternative splicing landscape of Drosha transcripts, we performed PacBio sequencing in different human cell lines. We identified two novel isoforms resulting from partial intron-retention in the region encoding the Drosha catalytic domain. One isoform (AS27a) generates a truncated protein that is unstable in cells. The other (AS32a) produces a full-length Drosha with a 14 amino acid insertion in the RIIID domain. By taking advantage of Drosha knockout cells in combination with a previously established reporter assay, we demonstrated that Drosha-AS32a lacks cleavage activity. Furthermore, neither Drosha-27a nor Drosha-32a were able to rescue miRNA expression in the Drosha knockout cells. Interestingly, both isoforms were abundantly detected in a wide range of cancer cell lines (up to 15% of all Drosha isoforms). Analysis of the RNA-seq data from over 1000 breast cancer patient samples revealed that the AS32a is relatively more abundant in tumours than in normal tissue, suggesting that AS32a may play a role in cancer development.

Long-lived colonial cold-water corals have the potential to provide robust continuous archives of environmental change. These high-resolution records of the subsurface ocean are particularly valuable, especially at understudied intermediate water depths. Yet, to understand the anthropogenic impacts on the sub-surface ocean and better predict future changes, it is critical to establish the natural variation of temperature and circulation of the ocean system prior to the Industrial Revolution.Here we combine temperature proxy and radiocarbon data from specimens of two taxa of cold-water coral that grew in intermediate water depths (~1500 m) in the tropical North Atlantic. In 2013, specimens of the bamboo coral Lepidisis spp. and scleractinian coral Enallopsammia rostrata were collected from sites currently situated in the boundary of North Atlantic Deep Water and Antarctic Intermediate Water to reconstruct the temperature and circulation history of the region. We demonstrate that bamboo corals can be used to reconstruct ambient seawater radiocarbon content when independently dated by organic node annual band counting. Radiocarbon was also analysed in Enallopsammia rostrata to develop age models for both the radial section and from discrete corallites (polyps) along a branch. Dating results show that this coral is about 500 years old, allowing us to generate a temperature record as far back as the Little Ice Age. Trace metal ratios were analysed along the growth axis of the coral, and the Li/Mg ratio was used as a temperature proxy. We find that the Li/Mg derived temperature of the most recent polyps is consistent with modern ambient temperature. The overall temperature record shows a general increasing trend since the Little Ice Age, while the radiocarbon record indicates no significant change until the late 20th century. Combining these records allows us to reconstruct potential ocean circulation changes in the central tropical North Atlantic over last 500 years.

The bottom mixed layer (BML) is a well mixed, weakly stratified bottom boundary layer adjacent to the seafloor, with a thickness of the order 10-100 m, and is considered a common feature of the deep water column in the ocean. First observed in the 1970s and documented extensively in the deep Northwest Atlantic Ocean in the 1980s, the abyssal ocean (depth > 4000 m) BMLs have not been well observed in other regions of the global oceans, particularly in the Northeast Pacific Ocean, and the dynamical processes that lead to their formation are not well understood. Turbulent diffusivity in the BML is estimated to be greater than in the interior ocean by an order of magnitude, and the presence of such layers is often associated with elevated level of turbidity and episodic events of sediment resuspension and transport, known as the benthic storms. Without a clear understanding of the variability and dynamics of these layers, assessing potential environmental impacts of proposed commercial activities in the deep sea, such as the exploitation of polymetallic nodules in the Clarion-Clipperton Fracture Zone (CCFZ) in the tropical Northeast Pacific, is challenging. In this study, we analyze observed profiles from conductivity-temperature-depth (CTD) measurements recently collected in the German licence area of the CCFZ, a region with abyssal hills west of the East Pacific Ridge. Quasi-uniform profiles of potential temperature, salinity, and potential density extending from the seafloor to a maximum of 475 m above bottom (mab) reveal the presence of a BML in the region with a thickness of O(100 m), using a mixed-layer quantification method based on potential temperature profiles. The BML thickness and structure vary both temporally and spatially, with three major characteristics: (i) a well-developed, statically stable BML with a thickness between 200 and 475 m; (ii) a less well-developed BML with a thickness of approximately 100 m; and (iii) a well developed BML with a thickness of around 400 m and multiple intrusive layering structures, each of which with a thickness of approximately 100 m, near bathymetric reliefs. These findings confirm the preliminary findings from the 1980s that benthic stratification in the region is weak and that a mixed layer may be present at the bottom. While our preliminary findings establish the presence of BML in the region, questions regarding the dynamical processes responsible for the temporal and spatial variabilities remain to be addressed. Further analyses using data from the eastern segment of the World Ocean Circulation Experiment (WOCE) tropical North Pacific (P04E) section are ongoing to understand the spatial variability of these layers in the region.

This paper uses the reconstruction-computation-quantization (RCQ) paradigm to decode low-density parity-check (LDPC) codes. RCQ facilitates dynamic non-uniform quantization to achieve good frame error rate (FER) performance with very low message precision. For message-passing according to a flooding schedule, the RCQ parameters are designed by discrete density evolution (DDE). Simulation results on an IEEE 802.11 LDPC code show that for 4-bit messages, a flooding MinSum RCQ decoder outperforms table-lookup approaches such as information bottleneck (IB) or Min-IB decoding, with significantly fewer parameters to be stored. Additionally, this paper introduces layer-specific RCQ (LS-RCQ), an extension of RCQ decoding for layered architectures. LS-RCQ uses layer-specific message representations to achieve the best possible FER performance. For LS-RCQ, this paper proposes using layered DDE featuring hierarchical dynamic quantization (HDQ) to design LS-RCQ parameters efficiently. Finally, this paper studies field-programmable gate array (FPGA) implementations of RCQ decoders. Simulation results for a (9472, 8192) quasi-cyclic (QC) LDPC code show that a layered MinSum RCQ decoder with 3-bit messages achieves more than a $10\%$ reduction in LUTs and routed nets and more than a $6\%$ decrease in register usage while maintaining comparable decoding performance, compared to a 5-bit offset MinSum decoder., This paper has been accepted by IEEE Transactions on Communication

Introduction: Use of oral anticoagulation (OAC) in patients with atrial fibrillation (AF) and cancer is challenging due to increased thrombotic and bleeding risks, and data on prescription patterns are lacking. Hypothesis: Underutilization of OAC among patients with AF and cancer is associated with cancer specific factors. Methods: This study examined OAC use and factors associated with discontinuation of OAC among Medicare patients with AF and a new diagnosis of cancer from 2011-2016. We described OAC use patterns prior to and after a diagnosis of cancer. Logistic regression was used to evaluate clinical variables associated with discontinuation of OAC at time of cancer diagnosis and cox proportional hazards model was used to evaluate variables associated with discontinuation after diagnosis. Results: Among 44,769 patients with established AF and newly diagnosed cancer, 30.2% (n=13,508) were taking OAC at the time of cancer diagnosis. A total of 15,228 patients (34%) had an OAC prescription fill after index cancer diagnosis. Warfarin was the most commonly used OAC, but direct oral anticoagulant use increased over the study period. A total of 29.5% of patients had their OAC discontinued at the time of cancer diagnosis. Patients with gastric (OR 2.75, CI 2.12-3.57), pancreatic (OR 2.71, CI 2.15-3.41), and colorectal (OR 1.97, CI 1.70-2.28) cancer were most likely to have their OAC discontinued at diagnosis (Figure). Bleeding (HR1.37, CI 1.28-1.48) and chemotherapy (HR 1.38, CI 1.06-1.80) were associated with subsequent discontinuation in those who remained on OAC after diagnosis. Conclusions: Nearly 2 in 3 patients with established AF were not treated with OAC after cancer diagnosis despite an elevated stroke risk. Significant heterogeneity in OAC use exists depending on cancer type, baseline comorbidities, and chemotherapy use. Studies are needed to characterize the thrombotic and bleeding risks in this population to establish management guidelines.

This study represents a first time that perstraction was assessed as a process to remove perfluorooctanoic acid (PFOA) from water. In the perstraction process, PFOA permeates through a membrane from water to a solvent. The membrane used in this study was polydimethylsiloxane (PDMS). The experimental approach included the following: (1) measurement of partition coefficients for PFOA between water and selected solvents; (2) determination of solubility and diffusivity of the solvents in PDMS; (3) determination of the uptake of PFOA in PDMS; (4) determination of the effects of selected particles imbedded in the PDMS on PFOA uptake and solvent absorption; and (5) demonstration of the perstraction process to remove PFOA from water. PFOA preferentially partitioned to alcohols over water. In addition, ZnO and CuO particles in PDMS significantly enhanced the rate at which PFOA was absorbed in PDMS from deionized water due to ionic interactions. The perstraction of PFOA from deionized water into hexanol was demonstrated. However, perstraction was not successful at removing PFOA from tap water. While the application of perstraction to removing PFOA from water is limited, the idea was demonstrated and information contained within this manuscript is new.

We outline a public license (open source) electron microscopy platform, referred to as NanoMi. NanoMi offers a modular, flexible electron microscope platform that can be utilized for a variety of applications, such as microscopy education and development of proof-of-principle experiments, and can be used to complement an existing experimental apparatus. All components are ultra-high vacuum compatible and the electron optics elements are independent from the vacuum envelope. The individual optical components are mounted on a 127 mm (5-inch) diameter half-pipe, allowing customizing of electron optics for a variety of purposes. The target capabilities include SEM, TEM, scanning TEM (STEM), and electron diffraction (ED) at up to 50 keV incident electron energy. The intended image resolution in SEM, TEM and STEM modes is ≈ 10 nm. We describe the existing components and the interfaces among components that ensure their compatibility and interchangeability. The paper provides a resource for those who consider building or utilizing their own NanoMi.

Extensive prior research shows that spacing – the distribution of studying over multiple sessions – significantly improves long-term learning in many disciplines. However, in computer science education, it is unclear if 1) spacing is effective in an incentivized, non-imposed setting and 2) when incentivized, female and male students space their studying differently. To investigate these research questions, we examined how students in an introductory computer science course (378 female and 310 male) spaced their studying. A retrieval practice tool in the course (for 5% of the course grade) incentivized students to space their studying, by awarding a point per day of usage. To measure how much each student spaced, we examined their interactions with the course eBook, which served as their primary learning resource. Specifically, when comparing two students with the same academic and demographic characteristics, the same measure of course easiness, and the same amount of content studied, we considered the student who distributed their studying over more days to be the one who spaced more. Using this definition, our structural equation modeling (SEM) results show that, 1) on average, students who spaced their studying over 14.516 more days (one standard deviation) got 2.25% higher final exam scores; and 2) female students spaced their studying over 4.331 more days than their male counterparts. These results suggest that, in an introductory computer science course, incentivized spacing is effective. Notably, when compared to their male counterparts, female students both exhibited more spacing and obtained higher final exam scores through spacing.

Mediating transcription The Mediator complex is recruited by transcription factors to all protein-coding genes in eukaryotes and helps to assemble the machinery necessary to transcribe the gene. Abdella et al. present the cryo–electron microscopy structure of the human Mediator-bound preinitiation complex (Med-PIC). The structure shows how Mediator positions the long, flexible C-terminal domain of RNA polymerase II to be phosphorylated by the kinase CDK7, a crucial step for further processing of the RNA into a mature RNA. Most sites where transcription factors bind to Mediator are flexibly tethered to the complex, allowing the large Med-PIC to assemble at any gene. Science , this issue p. 52

Benthic nepheloid layers (BNLs) are particle-rich layers that can extend over a thousand meter or more above the seafloor and are thought to be produced by the resuspension of fine sediments from strong bottom currents. They can often be subdivided into two sublayers: (i) a lower sublayer in contact with the seabed, where particle concentrations are the largest and which roughly coincides with the bottom mixed layer (BML); and (ii) an upper sublayer in which particle concentration decreases up to a clear water minimum (CWM). Although BNLs have long been recognised in vertical traces of optical instruments lowered to abyssal depths, their influence on ocean biogeochemical cycles – on the cycling of particle-reactive metals in particular – remains poorly understood.In this study, we characterize the BNLs observed between the New England continental shelf and Bermuda and explore their influence on the cycling of 230Th and 231Pa – two naturally-occurring particle-reactive radionuclides that have found different applications in chemical oceanography and paleoceanography. To this end, we use concomitant measurements of temperature, salinity, particle concentration derived from light beam transmissometry, and 230Th and 231Pa activities in the dissolved and particulate fractions, which have been collected along the western segment of the U.S. GEOTRACES GA03 transect. We estimate that the thickness of strong BNLs (particle concentration > 20 µg l-1) varied from about 72 to 1358 m between different deep stations. At all stations, particle concentrations below the CWM were the highest in the BML, whose thickness ranged from 95 to 320 m, and decreased generally with height above the seafloor. A simplified model of particle-radionuclide cycling in the deep water column, which includes a particle source representing sediment resuspension at topographic reliefs and their subsequent lateral transport, is fitted to observed profiles of particle concentration and radionuclide activities at two selected stations. The model can reproduce simultaneously the increase of particle concentration with depth, the low dissolved activities in the BNLs, and the extremely large particulate activities near the bottom. Analysis of 230Th and 231Pa budgets reveals that the behaviour of both radionuclides in the BNL is fundamentally different from that envisioned in reversible exchange theory. Sensitivity tests with the model suggest that lateral particle sources near continental slopes and similar reliefs can produce significant biases in the paleoceanographic applications of both radionuclides, including the 230Th-normalization method and the interpretation of sediment 231Pa/230Th records.

Genomic and adaptive determinants of organ-specific metastasis are poorly understood. A model of sequential acquisition of divergent somatic mutations is insufficient to explain metastasis. Liver metastasis (LM) occurs frequently and is associated with a poor prognosis and reduced therapy response in several cancers, including in patients with melanoma and lung cancer. To identify drivers of metastatic niches, we used a syngeneic mouse melanoma model which recapitulates genomic, metastatic and therapy response patterns seen in patients. We performed a large-scale in vivo CRISPR-Cas9 knockout screen and identified perturbations that promote LM, but not primary tumor growth or metastasis to other organs (e.g. lung). The “top hit” in this screen associated with LM was loss Pip4k2c. We generated Pip4k2cKO cells and show that in otherwise isogenic melanoma cell lines, loss of Pip4k2c led to increased baseline and insulin-induced activation of the PI3K/AKT pathway, and increased invasive capacity. Rescuing Pip4k2cKO with full-length (Pip4k2cRec) or allosteric domain deficient (Pip4k2cAD) Pip4k2c ORFs, we show that hyperactivation of the PI3K/AKT pathway in is mediated by loss of the allosteric domain function, and not loss of the kinase domain of Pip4k2c. Treatment with different PI3K inhibitors effectively abrogated the pathway, but was partly bypassed in the presence of insulin in Pip4k2cKO and Pip4k2cAD, but not parental or Pip4k2cRec cells. Upon tail vein injection, Pip4k2cKO cells produced a significantly increased LM burden compared to parental cells, and this effect was rescued in Pip4k2cRec but not Pip4k2cAD, further affirming that loss of allosteric domain was required for this phenotype. We reasoned that Pip4k2cKO cells preferentially colonized the liver by co-opting the insulin-rich milieu in this organ. To test this, we used shRNA targeted against the insulin receptor (Insr) generated Pip4k2cKO/InsrshIR and showed that Insr was required but not sufficient to enhance LM burden. Given the promising in vitro activity of PI3K inhibitors, we next tested whether these could abrogate LM in vivo. Surprisingly, we found a substantial increase in LM burden in mice with Pip4k2cKO-bearing LM treated with PI3K inhibition compared to vehicle treated animals. We show that this paradoxical observation was due to host-mediated increased in glucose and insulin in response to PI3K inhibitor, which promoted a forward loop of increased liver metastasis. Breaking this loop with either ketogenic diet or treatment with a SGLT2 inhibitor in turn rescued increased these host responses and resulted in reduced LM burden in combination with PI3K inhibition. In summary, we identify a novel mechanism of metastatic liver organotropism and pharmacological and dietary combinations to reduced liver metastatic burden. Given the expanding use of PI3K inhibitors, our findings may have important clinical implications. Citation Format: Meri Rogava, Johannes C. Melms, Stephanie Davis, Clemens Hug, Bryan Ngo, Michael J. Lee, Patricia Ho, Amit Dipak Amin, Yiping Wang, Sean Chen, William Ge, David Liu, Thomas Tüting, Martin Röcken, Thomas K. Eigentler, Samuel F. Bakhoum, Andrei Molotkov, Akiva Mintz, Lewis C. Cantley, Peter K. Sorger, Benjamin Izar. A genetic-metabolic axis of metastatic liver organotropism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 981.

The mechanism of negative group delay (NGD) is used to understand the anticipatory capability of a retina. Experiments with retinas from bull frogs are performed to compare with the predictions of the NGD model. In particulars, whole field stochastic stimulation with various time correlations are used to probe anticipatory responses from the retina. We find that the NGD model can reproduce essential features of experimental observations characterized by the cross correlations between the stimulation and the retinal responses. The prediction horizon of a retina is found to depend on the correlation time of the stimulation as predicted by the NGD model. Experiments with dark and bright Gaussian light pulses further support the NGD mechanism; but only for the dark pulses indicating that the NGD effect of a retina might originate from its OFF response. Our finding suggests that sensory systems capable of using negative feedback for adaptation can give rise to anticipation as a consequence of the delay in the system.

We present a new approach to improve the phase noise of a conventional transformer-coupled voltage-controlled oscillator (TC-VCO) for 5G mmWave application. Coupling capacitors are added to a single center-tapped transformer to introduce bandpass filtering that suppresses nonlinear conversion of second- and third-harmonic distortion to phase noise around the VCO fundamental. The resulting TC-VCO exhibits phase noise measured at -108.1 dBc/Hz at an offset of 1-MHz which is 4.3 dB better than a conventional TC-VCO. The proposed VCO is implemented in 16-nm finFET CMOS with a core area of only 0.011 mm2. It tunes over a measured frequency range of 27.2 to 27.7 GHz while consuming only 4 mW of dc power. The phase noise performance corresponds to a figure-of-merit (FoM) of -191 dBc/Hz which, to our knowledge, is the best reported FoM with the smallest core area among nanoscale CMOS VCOs operating near 27 GHz.

We are developing a modular (scanning) transmission electron microscope (S)TEM, referred to as NanoMi, which is released under an open source license by the National Research Council, Canada; see for updates. The electron microscope (EM) is a critical enabling tool in the physical, materials and biological sciences but its impact could be increased by the availability of an easy-to-build, customizable instrument capable of modest resolution and suitable for electron beam lithography, specialized experiments and for training personnel. An instrument that can be built for ~50 k$ and ~1 year of student time would fulfill these requirements in many laboratories around the world. Here we describe an initial design of such an instrument.

The naturally-occurring particle-reactive radionuclides protactinium-231 (231Pa) and thorium-230 (230Th) are used as tracers of a variety of oceanic processes, both at present and in the past. Most notably, the sediment 231Pa/230Th ratio has been used to infer changes in the Atlantic Meridional Overturning Circulation over the last (de)glaciation. However, recent measurements along the U.S. GEOTRACES North Atlantic transect (GA03) revealed two features which are at odds with current understanding about 231Pa and 230Th behaviour in the ocean: (i) a sharp decrease in dissolved 231Pa and 230Th activities with depth below 2000-4000 m and (ii) very large particulate 231Pa and 230Th activities near the bottom, at a number of stations between the New England continental shelf and Bermuda. Concomitant measurements of particulate matter concentration and potential temperature showed that both features are associated with the benthic nepheloid layer (BNL) and the bottom mixed layer (BML) that are present at these stations.Here we develop and apply a simplified model of the exchange of particles, 231Pa, and 230Th between the BNL and the upper sediment, to explore the extent to which the radionuclide anomalies observed near the bottom at a number of GA03 stations can be explained by local sediment resuspension. We find that the model can broadly reproduce the observed anomalies at two stations where samples for radionuclide analyses were collected near the seafloor. Sensitivity tests with the model show that the 231Pa/230Th ratio of particles in the BML and the sediment varies by a factor of 3 as the sediment resuspension rate fluctuates within a range consistent with observational estimates. The modelled variability is comparable to the spatial variability of 231Pa/230Th of suspended particles in the modern North Atlantic and to the variability of Atlantic sediment 231Pa/230Th records across the last (de)glacial period. Two factors are found to contribute to the modelled sensitivity of the sediment 231Pa/230Th to sediment resuspension rate: the vertical turbulent mixing in the BML and the differential scavenging intensity of Pa and Th due to variation in particle concentration. Overall, our study indicates that the exchange of material between the BNL and the upper sediment can affect the particulate 231Pa/230Th ratio in the bottom water and the sediment, which may complicate the use of sediment 231Pa/230Th as a palaeoceanographic tracer.

CRISPR/Cas9 technology has transformed mouse genome editing with unprecedented precision, efficiency, and ease; however, the current practice of microinjecting CRISPR reagents into pronuclear-stage embryos remains rate-limiting. We thus developed CRISPR ribonucleoprotein (RNP) electroporation of zygotes (CRISPR-EZ), an electroporation-based technology that outperforms pronuclear and cytoplasmic microinjection in efficiency, simplicity, cost, and throughput. In C57BL/6J and C57BL/6N mouse strains, CRISPR-EZ achieves 100% delivery of Cas9/single-guide RNA (sgRNA) RNPs, facilitating indel mutations (insertions or deletions), exon deletions, point mutations, and small insertions. In a side-by-side comparison in the high-throughput KnockOut Mouse Project (KOMP) pipeline, CRISPR-EZ consistently outperformed microinjection. Here, we provide an optimized protocol covering sgRNA synthesis, embryo collection, RNP electroporation, mouse generation, and genotyping strategies. Using CRISPR-EZ, a graduate-level researcher with basic embryo-manipulation skills can obtain genetically modified mice in 6 weeks. Altogether, CRISPR-EZ is a simple, economic, efficient, and high-throughput technology that is potentially applicable to other mammalian species.

The naturally-occurring radionuclides protactinium-231 (231Pa) and thorium-230 (230Th) are produced at approximately uniform rates in the ocean and thought to be removed from the water column through a reversible exchange with settling particles. Recent measurements along the U.S. GEOTRACES North Atlantic transect (GA03) revealed two features which are at odds with current understanding about 231Pa and 230Th cycling in the ocean: (i) a sharp decrease in dissolved 231Pa (231Pa d ) and 230Th (230Th d ) activities with depth below 2000–4000 m and (ii) very high particulate 231Pa (231Pa p ) and 230Th (230Th p ) activities near the bottom, at a number of stations between the New England continental shelf and Bermuda. Concomitant measurements of light attenuation from beam transmissometry showed that both features occur in benthic nepheloid layers (BNLs), which suggests that these features may stem, at least partly, from the presence of resuspended sediment in the deep water column. Here we explore the behaviour of 231Pa and 230Th in BNLs by using (i) radionuclide, optical, and hydrographic data from the western segment of GA03 (west of Bermuda) and (ii) a simplified model of particle and radionuclide cycling that includes a lateral particle source. First, the BNLs observed at GA03 stations are characterized from measurements of the beam attenuation coefficient converted to particle concentrations. At all stations, particle concentrations below the clear water minimum were the highest in the bottom mixed layer, whose thickness ranged from 95 to 320 m, and decreased generally with height above the bottom. The thickness of strong BNLs varied from 482 to 1358 m and the vertical integral of particle concentration in excess to that at the clear water minimum varied from 1 × 1 0 4 to 2 × 1 0 6 mg m−2, among different stations. Second, the particle-radionuclide model is fitted to data from stations GT11-04 (New England continental rise) and GT11-08 (Hatteras abyssal plain), where samples for radionuclide analyses were collected in the BNL. The model can reproduce simultaneously the increase of particle concentration with depth, the low 231Pa d and 230Th d in the BNLs, and the high 231Pa p and 230Th p near the bottom. According to the model, at heights less than about 300 m above the seafloor, the dissolved phase was set primarily by a balance between adsorption and desorption, with vertical turbulent mixing playing a secondary role, whilst the particulate phase behaved largely as a non-reactive constituent supplied laterally and transported vertically by particle settling and turbulent mixing. Sensitivity tests with the model suggest that lateral particle sources near continental slopes and similar reliefs can produce significant biases both in the 230Th normalization method and in the interpretation of sediment 231Pa/230Th records. Our findings yield insights into the influence of sediment resuspension and transport on 231Pa and 230Th in the deep ocean and highlight the need for considering these processes in paleoceanographic applications.

Summary: Genetically engineered mouse models harboring large sequence insertions or modifications are critical for a wide range of applications including endogenous gene tagging, conditional knockout, site-specific transgene insertion, and gene replacement; however, existing methods to generate such animals remain laborious and costly. To address this, we developed an approach called CRISPR-READI (CRISPR RNP electroporation and AAV donor infection), combining adeno-associated virus (AAV)-mediated HDR donor delivery with Cas9/sgRNA RNP electroporation to engineer large site-specific modifications in the mouse genome with high efficiency and throughput. We successfully targeted a 774 bp fluorescent reporter, a 2.1 kb CreERT2 driver, and a 3.3 kb expression cassette into endogenous loci in both embryos and live mice. CRISPR-READI is applicable to most widely used knockin schemes requiring donor lengths within the 4.9 kb AAV packaging capacity. Altogether, CRISPR-READI is an efficient, high-throughput, microinjection-free approach for sophisticated mouse genome engineering with potential applications in other mammalian species. : Generation of knockin mice harboring large insertions or sequence substitutions has relied primarily on costly and laborious microinjection-based CRISPR technology. Chen and Sun et al. developed the CRISPR-READI approach combining AAV-mediated donor delivery with Cas9/sgRNA RNP electroporation to engineer multi-kilobase modifications in the mouse genome with high efficiency and throughput. Keywords: CRISPR, genome editing, mouse models, knockin, electroporation, AAV, CRISPR-EZ, HDR editing

Predictive formulation design and accelerated formulation design can lead to the discovery of useful formulations to support drug clinical studies and successful drug approval. Predictive formulation design can also lead to discovery of a path for commercialization, especially for poorly soluble drugs, when the target product profile is well defined and a "learning before doing" approach is implemented. One of the key components of predictive/accelerated formulation design is to understand and leverage the material properties of drug substance including solubility, BCS classification, polymorphs, salt formation, amorphous form, amorphous complex, and stability. In addition, utilizing synchrotron-based PDF (pair distribution function) analysis can provide important structural information for the formulation. This knowledge allows control of physical and chemical stability of the designed product. Finally, formulation design should link to process development following Quality by Design principles, and solid-state chemistry should play a critical role in many of the steps required to achieve Quality by Design, which can lead to successful product development.

Liquid biopsies are revolutionizing the fields of prenatal non-invasive testing and cancer diagnosis by leveraging the genetic differences between mother and fetus, and, host and cancer. In the absence of genetic variance, epigenetics has been used to decipher the cell-of-origin of cell-free DNA (cfDNA). Liquid biopsies are minimally invasive and thus represent an attractive option for hard to biopsy tissues such as the brain. Here we report the first evidence of neuron derived cfDNA and cerebellum cfDNA within acute neurotrauma and chronic neurodegeneration, establishing the first class of peripheral biomarkers with specificity for the cell-type and brain-region undergoing potential injury and/or neurodegeneration.

The accounting profession traditionally regards materiality assessment as the auditor's professional judgment, which is misleading. The Financial Accounting Standards Board's (FASB) concept statements emphasized that materiality must be evaluated from the user's perspective rather than accountant's. The Supreme Court of United States' landmark case of Matrixx Inc. et al. Petitioners v. James Siracusano et al. (2011) alerted the accounting profession about the legal effect of accountants' professional judgment on materiality. The FASB, consequently, proposed in a recent exposure draft to revise its concept statement by adding “refer to materiality as a legal concept.” This article analyzes the Supreme Court case to provide insight into the Supreme Court's reasoning and the impact of the FASB's intended concept statement on financial accounting and auditing. A simple interpretation of the Supreme Court's position is that materiality judgment should be made from the user's perspective rather than from the preparer's. Ultimately, the key issue is whether the preparer presents financial statement faithfully. If the FASB's exposure draft is adopted, it will affect management and auditors in different ways. When management doubts their judgment of materiality, they have to gather sufficient evidence to substantiate the position of immateriality. In other words, it is nice to say that “an omission of immaterial information is not an accounting error”; it is difficult to prove that the preparer has the correct interpretation of the investors' view on materiality. A lot of work on substantiating the evidence on immateriality is still required. On the other hand, auditors will have to expand their work related to materiality assessment to include the review of the client's other formal or informal statements and communications beyond the scope of a traditional audit. © 2017 Wiley Periodicals, Inc.