In the effort to prevent school shootings in the United States, policies that aim to arm teachers with guns have received considerable attention. Recent research on public support for these policies ...finds that African Americans are substantially less likely to support them, indicating that support for arming teachers is a racial issue. Given the racialized nature of support for punitive crime policies in the United States, it is possible that racial sentiment shapes support for arming teachers as well. This study aims to determine the association between two types of racial sentiment—explicit negative feelings toward racial/ethnic minority groups and racial resentment—and support for arming teachers using a nationally representative data set. While explicit negative feelings toward African Americans and Hispanics are not associated with support for arming teachers, those with racial resentments are significantly more likely to support arming teachers. Racial resentment also weakens the effect of other variables found to be associated with support for arming teachers, including conservative ideology and economic pessimism. Implications for policy and research are discussed.
Xylitol is a highly valuable commodity chemical used extensively in the food and pharmaceutical industries. The production of xylitol from d‐xylose involves a costly and polluting catalytic ...hydrogenation process. Biotechnological production from lignocellulosic biomass by micro‐organisms like yeasts is a promising option. In this study, xylitol is produced from lignocellulosic biomass by a recombinant strain of Saccharomyces cerevisiae (S. cerevisiae) (YPH499‐SsXR‐AaBGL) expressing cytosolic xylose reductase (Scheffersomyces stipitis xylose reductase SsXR), along with a β‐d‐glucosidase (Aspergillus aculeatus β‐glucosidase 1 AaBGL) displayed on the cell surface. The simultaneous cofermentation of cellobiose/xylose by this strain leads to an ≈2.5‐fold increase in Yxylitol/xylose (=0.54) compared to the use of a glucose/xylose mixture as a substrate. Further improvement in the xylose uptake by the cell is achieved by a broad evaluation of several homologous and heterologous transporters. Homologous maltose transporter (ScMAL11) shows the best performance in xylose transport and is used to generate the strain YPH499‐XR‐ScMAL11‐BGL with a significantly improved xylitol production capacity from cellobiose/xylose coutilization. This report constitutes a promising proof of concept to further scale up the biorefinery industrial production of xylitol from lignocellulose by combining cell surface and metabolic engineering in S. cerevisiae.
Xylitol is produced from lignocellulosic biomass (rice straw hydrolysate; kraft pulp residues) by a recombinant strain of Saccharomyces cerevisiae (S. cerevisiae) (YPH499‐SsXR‐ScMAL11‐AaBGL). This strain is expressing cytosolic xylose reductase (Scheffersomyces stipitis xylose reductase SsXR), along with the homologous maltose transporter (ScMAL11) and β‐d‐glucosidase (Aspergillus aculeatus β‐glucosidase 1 AaBGL) displayed on the cell surface, to efficiently co‐utilize cellobiose and xylose to produce xylitol.
The dogma of engineering oncolytic viral vectors has shifted from emphasizing the viral lysis of individual cancer cells to the recruitment and coordination of the adaptive immune system to clear the ...tumor. To accomplish this, researchers have been adding several classes of transgenes to their preferred viral platforms. The most prevalent of these include antibodies and targeting moieties, interleukins and cytokines, and genes which rely on small molecule co-administration for tumor killing. Most current vectors rely exclusively on one of these types of transgenes to elicit the desired immune response to clear tumors, but are not mutually exclusive, with several larger OVs armed with several of these factors. The common theme of emerging armed vectors is to simply initiate or enhance infiltration of effector CD8+ T cells to clear the tumor locally at OV infection sites, and systemically throughout the body where the OV has not infected tumor cells. The precision of oncolytic vectors to target a cell type or tissue remains its key advantage over small-molecule drugs. Unlike chemo- and other drug therapies, viral vectors can be made to specifically infect and grow within tumor cells. This ensures localized expression of the therapeutic transgene to the diseased tissue, thereby limiting systemic toxicity. This review will examine the immunomodulating transgenes of current OVs, describe their general effect on the immune system, and provide the rationale for each vector’s use in clearing its targeted tumor.
Although school violence statistics indicate that schools are safe places, anxiety over school shootings continues to influence school safety reform to the extent that security measures in American ...public schools include the arming of schoolteachers. Furthermore, not only have youths’ perceptions of school security been relatively unexplored, existing research points to racial inequalities in the use of and the effects of school security practices. This study uses data from high school students across multiple school districts in a Midwestern county to examine how race and perceptions of fairness intersect to influence attitudes on arming teachers. The results suggest that, relative to White students, Black students are less supportive of arming teachers and anticipate greater decreases in safety if teachers are armed. In addition, perceptions of fairness mediate the effect of race on support and feelings of safety. Implications for policy and future research are discussed.
This paper examines third-party trade and its implications for conflicts between hostile countries not engaging in trade. We present a conflict-theoretic model to analyze two adversaries' endogenous ...arming decisions when they separately establish a free trade agreement (FTA) with a neutral third-party state. We contrast this multiple FTAs regime with a single FTA regime between one adversary and the third-party state, which excludes the other adversary as a non-member. In our analysis, the benchmark case is a protectionist regime when the bilateral trade between the third-party state and each of the adversaries is a tariff war. Among the three trade regimes, we show that the two adversaries' aggregate arming is the lowest under multiple FTAs but is the highest under a single FTA. These results suggest that, despite no trade between two adversary countries, multiple FTAs through third-party trade have the pacifying or appeasing effect of lowering overall military buildups in interstate conflicts.
Cassava (
Manihot esculenta Crantz) pulp, produced in large amounts as a by-product of starch manufacturing, is a major biomass resource in Southeast Asian countries. It contains abundant starch ...(approximately 60%) and cellulose fiber (approximately 20%). To effectively utilize the cassava pulp, an attempt was made to convert its components to ethanol using a sake-brewing yeast displaying glucoamylase on the cell surface.
Saccharomyces cerevisiae Kyokai no. 7 (strain K7) displaying
Rhizopus oryzae glucoamylase, designated strain K7G, was constructed using the C-terminal-half region of α-agglutinin. A sample of cassava pulp was pretreated with a hydrothermal reaction (140
°C for 1
h), followed by treatment with a
Trichoderma reesei cellulase to hydrolyze the cellulose in the sample. The K7G strain fermented starch and glucose in pretreated samples without addition of amylolytic enzymes, and produced ethanol in 91% and 80% of theoretical yield from 5% and 10% cassava pulp, respectively.
In this paper, a mechanical MEMS S&A device has been proposed. The size of the device is 10mm×13mm×0.5mm. The role of the lock-releasing mechanism is to amplify the moving distance of two times, so ...as to effectively guarantee the time of long-distance arming. Through establishing the three-dimensional model of without optimized lock-releasing mechanism, establishing the force and the parameters of locking-releasing mechanism, deriving the mathematical model according to the rigid dynamic mechanics theory and establishing the finite element model by using ANSYS/LS-DYNA, appropriate lock-releasing mechanism is designed to meet two items, one item is that the lock-releasing rod locks the main centrifugal slider before sub-centrifugal slider movement in place; the other item is that sub-centrifugal slider will hit the lock-releasing rod when it movement in place, so the lock-releasing rod rotates around rotational positioning block and releases the main centrifugal slider.
A safety and arming device with a condition feedback function has been designed in this article to improve the intelligence and safety of ignition devices. The device achieves active control and ...recoverability by virtue of four groups of bistable mechanisms which consist of two electrothermal actuators to drive a semi-circular barrier and a pawl. According to a specific operation sequence, the barrier is engaged by the pawl at the safety or the arming position. The four groups of bistable mechanisms are connected in parallel, and the device detects the contact resistance generated by the engagement of the barrier and pawl by the voltage division of an external resistor to determine the parallel number of the mechanism and give feedback on the device's condition. The pawl as a safety lock can restrain the in-plane deformation of the barrier in the safety condition to improve the safety function of the device. An igniter (a NiCr bridge foil covered with different thicknesses of Al/CuO films) and boron/potassium nitrate (B/KNO
, BPN) are assembled on both sides of the S&A device to verify the safety of the barrier. The test results show that the S&A device with a safety lock can realize the safety and arming functions when the thickness of the Al/CuO film is set to 80 μm and 100 μm.
Arming teachers remains a divisive issue in the United States. Since one goal of this policy is to improve perceptions of safety, it is important to understand how arming teachers impacts students. ...Using survey data from six Midwestern school districts, we apply Ferraro's risk assessment model to explore how individual and school conditions impact feelings of safety if teachers carry guns in school. We find perceived risk of victimization decreases feelings of safety if teachers are armed, which is driven by self-reported and vicarious victimization. Self-reported delinquency, in contrast, is directly related to feeling safer if teachers are armed. We conclude that arming teachers may mitigate efforts to help students feel safe in school by increasing fear among those with victimization experiences.
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