1,900 research outputs found
Race as Technology: From Posthuman Cyborg to Human Industry
Cyborg and prosthetic technologies frame prominent posthumanist approaches to understanding the nature of race. But these frameworks struggle to accommodate the phenomena of racial passing and racial travel, and their posthumanist orientation blurs useful distinctions between racialized humans and their social contexts. We advocate, instead, a humanist approach to race, understanding racial hierarchy as an industrial technology. Our approach accommodates racial passing and travel. It integrates a wide array of research across disciplines. It also helpfully distinguishes among grounds of racialization and conditions facilitating impacts of such racialization
Genetic Substrates of the Initial Subjective Rewarding Effects of Alcohol in Mice
Susceptibility to alcohol use disorders (AUDs) arises from a complex interplay of genetics and environmental experiences. While the initial subjective response predicts susceptibility to AUD, genetic variation is responsible for about 50% of an individual\u27s risk. This study used a single-exposure conditioned place preference paradigm (SE-CPP) to identify phenotypic and genetic correlates of the initial subjective rewarding effects of alcohol (EtOH) in diversity outbred (DO) mice. We assessed the relationship between SE-CPP and anxiety-like behaviors using a marble burying test and light-dark box test. Ninety-six male and female diversity outbred mice were tested in a Marble Burying test at 7-8 weeks, followed by the light-dark box at 9-10 weeks of age. Between 11-12 weeks, subjects were assessed for SE-CPP. Animals received 1.5 g/kg EtOH or equivolume saline on either Day 1 and Day 3 in two distinct contexts (counterbalanced) and were tested for a context preference on Day 5. Overall, SE-CPP was evident in both males and females. In females, there was a correlation between the percentage of time spent in the EtOH-paired context and the number of marbles buried four weeks prior. In males, there was a correlation between the distance traveled during EtOH conditioning and the percentage of time spent in the EtOH-paired context. Genotyping will be used to understand the possible link between the observed phenotypes and genetic variation. This research contributes to a better understanding of the influences of sex and genetic variation in AUD
DIFFERENCES IN LOWER LIMB JOINT STIFFNESS IN MULTIPLE MOVEMENTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION
Altered lower limb joint kinetics are frequently observed following anterior cruciate ligament reconstruction (ACLR), which may lead to an increased risk of re-injury. The aim of this study was to establish the extent to which joint stiffness differs in a unilateral and bilateral drop jump, and a 90° pre-planned cut following ACLR. A cohort of 127 male patients 8–10 months post-ACLR and 45 non-injured controls took part in the study. Both a unilateral and bilateral drop jump, and a 90° pre-planned cut were completed, while ground reaction forces and three-dimensional kinematics were recorded. ACLR patients had lower knee stiffness for the cut (d=0.192, p=0.040) and the bilateral drop jump (d=0.534,
Prognosis for Ecosystem Recovery Following Rodent Eradication and Seabird Restoration in an Island Archipelago
Invasive species are widespread and can have devastating effects on biota,
especially insular biota. Invasive species eradications are increasingly employed to promote
island recovery to preinvasion states. However, it remains unclear if additional restoration
actions may be required on islands that were once heavily reliant on seabird guano for
ecosystem functions. Active seabird augmentation has been suggested as necessary to exact
ecosystem recovery on contemporary timescales in some cases. I use two experiments on
offshore islands in Cook Strait, New Zealand, to test the hypothesis that seabird restoration
will restore island ecosystem functioning following invasive rodent removal. The first is a
small-scale single-island fertilization experiment that simulates seabird recovery. This
experiment tested the recovery potential of offshore islands and was used to infer the density
of seabirds needed to elicit ecosystem recovery. The second is a large-scale natural experiment
that takes advantage of eight islands with differing rodent eradication and seabird restoration
histories. I compared ecosystem functioning variables (d15N, C:N ratios in soil, plants, and
spiders, as well as arthropod abundance and diversity) on two islands that had rodents
eradicated and two islands undergoing seabird augmentation with two control islands (never
invaded by rodents) and two positive control islands (currently invaded by rodents). The
results suggest that islands do have the potential for recovery given nutrient amendments, but
that islands with rodents eradicated and islands undergoing seabird augmentation have not
recovered most of their ecosystem function. Finer, intra-island analysis showed that seabird
restoration projects have the potential to speed the recovery process, but that the projects on
the studied seabird restoration islands were not advanced enough to produce island-wide
recovery. The results suggest that high seabird densities (5–10 burrows/m2) are needed to
promote recovery to never-invaded control levels. Seabird augmentation, through chick
translocation and/or social facilitation with decoys, vocalization playbacks, and/or mirrors
can supplement passive seabird recovery on islands where seabirds have been extirpated or
extremely reduced by invasive predators. Such restoration efforts may be necessary to promote
ecosystem recovery on contemporary timescales
Elucidation of UBQLN2 liquid-liquid phase separation mechanisms via point mutations and domain deletions
Organization, separation, and cellular regulation are all functions of membraneless organelles (MLOs), which arise by a biophysical phenomenon termed liquid-liquid phase separation (LLPS). By this process, macromolecules in a mixed liquid solution condense together to form liquid droplets within a liquid solution, comparable to oil droplets in water. Some known MLOs formed in cells via LLPS include nucleoli, stress granules, Cajal bodies, and processing-bodies, among other membrane-lacking liquid granules. Previous work has shown that many proteins which compose these liquid compartments also undergo LLPS isolated in vitro, and thus have become model systems to investigate the forces that drive these macromolecules to undergo phase transitions.
Currently, the LLPS field has identified key features of proteins which contribute to phase separation. Included in this are sequences of intrinsic disorder and structured sequences, prion-like regions, oligomerization, and multivalent interactions. In this thesis, the protein of interest, UBQLN2, contains all such features. Additionally, prior work in the Castañeda lab and others has shown that UBQLN2 is recruited to stress granules, and disease-related inclusion bodies. In vitro, UBQLN2 phase separates into spherical liquid droplets in a concentration and temperature-dependent manner. As UBQLN2 exhibits LLPS both in vitro and in vivo, it serves as a model system to uncover, on a molecular level, the driving forces of phase separation.
The studies provided herein, investigate the properties of UBQLN2 phase separation and how they are modified with the introduction of mutations and domain deletions. By identifying how molecular variations modify UBQLN2 LLPS properties, one can identify a molecular code which UBQLN2 follows to drive and modulate its LLPS. Through experimental investigation via turbidity assays, phase diagram construction, microscopy, and self-association studies, we elucidate the molecular foundations of UBQLN2 LLPS.
Here, I propose that UBQLN2 LLPS is driven by “sticker” sequences which contribute to interchain interactions, and that hydrophobic and polar interactions are important sequence-intrinsic features which drive LLPS and control material properties of UBQLN2 droplets. Additionally, I look at UBQLN2 on a domain-by-domain level to uncover how sequence features like structure, disorder, and prion propensity may contribute differently to phase separation. Finally, I propose a method of UBQLN2 purification that potentially incorporates native post-translational modifications (PTMs) to create a more physiologically relevant system for study
Seabird Islands Take Mere Decades to Recover Following Rat Eradication
Islands house a majority of the world’s biodiversity and are thus critical for
biodiversity conservation. Seabird nesting colonies provide nutrients that are integral to
maintain island biodiversity and ecosystem function. Invasive rats destroy seabird colonies
and thus the island ecosystems that depend on seabird-derived nutrients. After rat eradication,
it is unclear how long ecosystem recovery may take, although some speculate on the order of
centuries. I looked at ecosystem recovery along a chronosequence of islands that had 12–22
years to recover following rat eradication. I show that soil, plant, and spider marine-derived
nitrogen levels and C:N ratios take mere decades to recover even after centuries-long rat
invasion. Moreover, active seabird restoration could speed recovery even further, giving much
hope to quickly conserve many endemic species on islands worldwide
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