Canisius College

Abstract The potential of the intense secondary muon, neutrino, and (hypothetical) light dark matter beams at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) is explored. These are produced in the high-power dumps with high-current electron beams. Light dark matter searches with the approved Beam Dump eXperiment (BDX) are driving the realization of a new underground vault behind Hall A that could be extended to a Beamdump Facility with little additional installations. High-energy muons created via the Bethe–Heitler process uniquely do not proceed through the more common pion production and decay channels. Several possible muon physics applications are highlighted. Neutrino detector technologies and experiments suitable for a beamdump facility are outlined.

Measurements of beam single-spin asymmetries in semi-inclusive deep-inelastic electron scattering (SIDIS) with positively charged kaons off protons have been performed with 10.6 and 10.2 GeV incident electron beams using the CLAS12 spectrometer at Jefferson Lab. We report an analysis of the electroproduction of positively charged kaons over a large kinematic range of fractional energy, Bjorken x , transverse momentum, and photon virtualities Q 2 ranging from 1 GeV 2 up to 6 GeV 2 . This is the first published multidimensionally binned CLAS12 measurement of a kaon SIDIS single-spin asymmetry in the valence quark regime. The data provide constraints on the structure function ratio F L U sin ϕ / F U U , where F L U sin ϕ is a quantity with a leading twist of twist-3 that can reveal novel aspects of the quark-gluon correlations within the nucleon. The impact of the data on understanding the underlying reaction mechanisms and their kinematic variation is explored using theoretical models for the different contributing twist-3 parton-distribution functions (PDFs) and fragmentation functions (FFs).

Abstract Territorial behaviour is exhibited by a wide variety of species for reasons such as resource control, mate acquisition, or protection of offspring. Most studies of short-term territorial activity focus on diurnal behaviours. Here, we present evidence of male nocturnal territorial behaviour by a subset of the Leon Springs pupfish population. Approximately half of the males behaved cathemerally, defending their territories during the daytime and continuing to do so through the nighttime hours (Cathemeral Defenders). In contrast, other males did not defend nor spend significant time within their territories at night (Day Defenders). None of the defensive variables examined (male patrols, chasing behaviours, or frequency of conspecific and heterospecific intruders) predicted which male pupfish would exhibit cathemeral territorial behaviour. The absolute number of spawns observed during the day also were not predictive of which males continued to hold nighttime territories, but there appeared to be an inverse relationship with diurnal mating success: males that did not spawn during daytime observations were more likely to maintain nighttime territories. These results indicate that further investigation into cathemeral behaviour is required to understand the optimal expression of territorial behaviour.

We present the first threefold differential measurement for neutral-pion multiplicity ratios produced in semi-inclusive deep-inelastic electron scattering on carbon, iron, and lead nuclei normalized to deuterium from CLAS at Jefferson Lab. We found that the neutral-pion multiplicity ratio is maximally suppressed for the leading hadrons (energy fraction z→ 1), suppression varying from 25% in carbon up to 75% in lead. An enhancement of the multiplicity ratio at low z and high pT2 is observed, suggesting an interconnection between these two variables. This behavior is qualitatively similar to the previous twofold differential measurement of charged pions by the HERMES Collaboration and, recently, by CLAS Collaboration. The largest enhancement was observed at high pT2 for heavier nuclei, namely, iron and lead, while the smallest enhancement was observed for the lightest nucleus, carbon. This behavior suggests a competition between partonic multiple scattering, which causes enhancement, and hadronic inelastic scattering, which causes suppression.

Transgenic tobacco, demonstrating bacterial cholesterol oxidase (CO) activity in the chloroplast, grown at PAR ~280 μmol(photon) m–2s–1 (low light), contained thylakoid membranes that include a greater variety of steroids and had reduced contents of sterol and sterol-esters per milligram chlorophyll in comparison to controls. The mature transgenic plants, grown at low light, demonstrate a ~3× larger root dry mass, ~3× larger stem dry mass, ~2× larger leaf dry mass, ~2× increased leaf number, and ~5× increased flower number than controls. Mature transgenic flowering plants, develop to first flower ~2× faster and grow ~30% taller than control flowering plants. The transgenic seedlings contain approximately 2× higher amounts of brassinolide (BR) per g fresh mass than controls. We propose that since the CO enzyme produces increased contents of oxidized steroids in the thylakoid membrane, this encourages enhanced photosynthesis, enhanced BR contents, and increased biomass accumulation.

Research suggests autistic children learn and generalize visual family-resemblance categories atypically (e.g., Church, et al., 2010, 2015), particularly when learning incidentally from exposure. This may reflect differences in perceptual learning (Mercado et al., 2020). However, it is unknown whether perceptual discrimination learning is also atypical and if differences extend to other modalities. To address this, autistic children with normal language abilities and IQ and typically developing (TD) matched comparison children completed auditory and visual discrimination tasks, after either incidental exposure to or direct training with stimuli presented in either progressive (easy-to-hard) or random orders of difficulty. In the visual task, both autistic and TD children only performed well after progressive training, suggesting limited perceptual learning from incidental visual exposure. In the auditory task, autistic children showed a progressive learning advantage after both exposure and training, but TD children only showed this advantage after training. They also had significantly better auditory discrimination than TD children after progressive training. These findings suggest typical visual discrimination learning after progressive training and enhanced auditory discrimination learning after progressive training and exposure. This enhanced auditory perceptual learning may help explain why these autistic children are socially impaired while retaining the capacity to learn language.

In the beginning of the twenty-first century, when algorithms are monitoring our most intimate activities, the data-driven relationships created by digital hyperconnectivity attempt to reduce the distance between us and flatten our differences. Kristeva’s question, “Can the ‘foreigner’ […] disappear from modern societies?” (Kristeva 1991, 1), raises concerns about this ostensibly frictionless future. She sees the difference inherent in foreignness as a flux of possibilities to be explored, rather than a quality to be homogenized, as data algorithms do. However, the desire to encounter the “essential enigma” of foreignness (Kristeva 1991, 33; emphasis in original) both with regards to an external Other and to our own unconscious, has been rendered not only redundant but progressively vestigial by the intellectual, cultural, and material vacuums created by artificial intelligence (AI). In an age when the superficial comfort of hyperconnectivity proclaims to alleviate the sense of being uprooted “from a family, a country or a language,” Kristeva reminds us that “[w]riting is impossible without some kind of exile” (Kristeva 1986, 298). To attempt to resurrect the potential of dissidence Kristeva sees in exile would be to dissolve AI’s maniacal efforts to categorize identity in favor of disarticulating it – a task at the heart of Kristeva’s intellectual project. It would also imply undermining the centrality of efficiency in neoliberal societies, because the quest for efficiency culminates in a system for the accounting-like management of life as well as in the adolescent “malady of ideality” (Kristeva 2019, 322), which seeks to extract a neatly structured order from the disorganized plurality of human activity at the nexus of the semiotic and the symbolic. This essay aims to provide not only a Kristevan critique of AI’s flattening of life’s dimensions, but also open potential avenues for revolt based on Kristeva’s psychoanalytic and political work.