Young stellar objects (YSOs) are protostars that exhibit bipolar outflows fed by accretion disks. Theories of the transition between disk and outflow often involve a complex magnetic field structure thought to be created by the disk coiling field lines at the jet base; however, due to limited resolution, these theories cannot be confirmed with observation and thus may benefit from laboratory astrophysics studies. We create a dynamically similar laboratory system by driving a $\sim$1 MA current pulse with a 200 ns rise through a $\approx$2 mm-tall Al cylindrical wire array mounted to a three-dimensional (3-D)-printed, stainless steel scaffolding. This system creates a plasma that converges on the centre axis and ejects cm-scale bipolar outflows. Depending on the chosen 3-D-printed load path, the system may be designed to push the ablated plasma flow radially inwards or off-axis to make rotation. In this paper, we present results from the simplest iteration of the load which generates radially converging streams that launch non-rotating jets. The temperature, velocity and density of the radial inflows and axial outflows are characterized using interferometry, gated optical and ultraviolet imaging, and Thomson scattering diagnostics. We show that experimental measurements of the Reynolds number and sonic Mach number in three different stages of the experiment scale favourably to the observed properties of YSO jets with $Re\sim 10^5\unicode{x2013}10^9$ and $M\sim 1\unicode{x2013}10$, while our magnetic Reynolds number of $Re_M\sim 1\unicode{x2013}15$ indicates that the magnetic field diffuses out of our plasma over multiple hydrodynamical time scales. We compare our results with 3-D numerical simulations in the PERSEUS extended magnetohydrodynamics code.

The U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed–crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America’s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency’s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being.

This article focusses on the career of Ben Burns, a white Jewish radical who came to play a central role in Chicago's black press during the mid-twentieth century. As an editor for periodicals such as the Chicago Defender, Negro Digest and Ebony, Burns helped to edit and develop some of the nation's most influential black publications. However, many of his readers remained oblivious to his racial identity – something which was both implicitly and explicitly obscured by his employers, and which was influenced by and manifested itself through the spatial politics of the workplace and the Chicago South Side. Drawing on a range of archival and biographical material, personal correspondence, and newspaper and magazine articles, this paper reconsiders Burns's literal movement through the terrain of Chicago's black press to assess his broader influence as a white editor in black journalism. Complicating depictions of Burns as a racial interloper, this article situates his contributions within a broader history of white participation in black print production. Furthermore, it demonstrates how the parameters of his role were heavily framed by the complex racial and spatial politics of the editorial room and Chicago's urban politics at mid-century.

We report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5×106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 ± 0.1 ka. However, more investigation is needed to confirm this association.

This article explores the role of Ebony magazine as a key staging ground for competing political and ideological debates over Martin Luther King Jr's legacy, and the struggle for a national holiday in his name. In doing so, it provides an important case study into the contestations between what Houston Baker has described as “black critical memory” and “black conservative nostalgia.” In response to attempts by Ronald Reagan and other politicians to reimagine King as an advocate for color-blind conservatism, Ebony’s senior editor, Lerone Bennett Jr., sought to situate King's legacy within a radical “living history” of black America. However, the magazine's broader coverage of the King holiday movement betrayed underlying tensions within its discussion of King's legacy, and fed into the magazine's role as an inadvertent frame for color-blind ideologies during the 1980s.

By incorporating dielectrics with stored electric fields and organic semiconductors, new organic electronic components such as circuits with controlling voltages “restored” for transistor tuning can be developed. We have successfully used excellent electret materials including charged and surface-treated silicon dioxide (SiO2) and silsesquioxane (SSQ) polymers as the dielectric layer in organic field-effect transistors (OFETs). Charge injection and quasipermanent charge storage induce threshold voltage shifts and current modulation, which results from the built-in electric fields in the conduction channels. Static and dynamic characteristics of organic thin-film transistors (OTFTs) such as charging conditions and voltage/current retention were evaluated. In addition, self-assembled monolayers (SAMs) of dipolar molecules have been utilized in the dielectric layer, with different mechanisms but similar effects compared to charged dielectrics. We also present new OFET unipolar inverters, comprised of only two simple OTFTs with enhancement-mode driver and depletion-mode load to implement full-swing organic logic circuits for process simplification of electronic components in organic electronics.

Since the first reports of charge storage in the gate dielectrics of organic semiconductors, several groups have proposed charge-storing dielectrics that become polarized through varied mechanisms, and have offered various explanations for observed charge storage phenomena. These groups were concerned either with nonvolatile memories as an application, or with controlling hysteresis in conventional OFETs. This manuscript describes measurements of surface charging and OFET threshold voltage shift for a case where charge is clearly stored in the dielectric. The magnitude and stability of the charge storage depend on the hydrophobicity of the dielectric and the charge deposition process. We focus on SiO2 as the dielectric and use a thiophene oligomer or hexadecafluoro-copper phthalocyanineas semiconductor. In one case, the phthalocyanine was inverted from electron- to hole-carrying, enabling a complementary device to be made from a single semiconductor.

Blood isolates from 13 patients in one hospital were positive for Klebsiella pneumoniae over a two-week period. Vials of potassium chloride used in intravenous fluid admixture initially were suspected of being contaminated and thus causing the problem. However, a comparison of patients who had blood cultures positive for K. pneumoniae with control patients who had blood cultures negative for this organism during the same period identified no common features that would explain the increase in K. pneumoniae blood isolates. Careful evaluation of laboratory data suggested that six of the 13 culture-positive patients had probable pseudobacteremia, an explanation that would account for the increase in isolates above the endemic level of true K. pneumoniae bacteremia in the hospital. Epidemiologic data suggested that cross-contamination of adjacent and non-adjacent blood culture vials on the radiometric blood culture analyzer was the cause of pseudobacteremia; K. pneumoniae serotyping data supported this hypothesis. A mocktrial using the analyzer demonstrated that cross-contamination of non-adjacent vials by the sampling needles could occur. Changing the sampling needles of the analyzer daily, in accordance with the manufacturer's recommendations, prevented further episodes of pseudobacteremia from the analyzer. [Infect Control 1981; 2(6):460-465.]