Assessing Controls on Ice Dynamics at Crane Glacier, Antarctic Peninsula, Using a Numerical Ice Flow Model

The Antarctic Peninsula\u27s widespread glacier retreat and ice shelf collapse have been attributed to atmospheric and oceanic warming. Following the initial post-collapse period of retreat, several former tributary glaciers of the Larsen A and B ice shelves have been slowly re-advancing for more than a decade. Here, we use a flowline model of Crane Glacier to gauge the sensitivity of former tributary glaciers to future climate change following this period of long-term dynamic adjustment. The glacier\u27s long-term geometry and speed changes are similar to those of other former Larsen A and B tributaries, suggesting that Crane Glacier is a reasonable representation of regional dynamics. For the unperturbed climate simulations, discharge remains nearly unchanged in 2018–2100, indicating that dynamic readjustment to shelf collapse took ~15 years. Despite large uncertainties in Crane Glacier\u27s past and future climate forcing, a wide range of future climate scenarios leads to a relatively modest range in grounding line discharge (0.8–1.5 Gt a−1) by 2100. Based on the model results for Crane, we infer that although former ice shelf tributaries may readvance following collapse, similar to the tidewater glacier cycle, their dynamic response to future climate perturbations should be less than their response to ice shelf collapse

Pain sensitivity, negative affect, and alcohol use disorder status: A moderated mediation study of emotion dysregulation

Previous work suggests that the association between pain and emotional processes among individuals with alcohol use disorder (AUD) may differ from healthy controls. This study inves-tigates whether pain sensitivity mediates the association between negative affect and emotional dysregulation and whether this association differs across AUD status using moderated mediation. The sample included 165 individuals diagnosed with AUD and 110 healthy controls. Of interest was pain sensitivity, as assessed with the Pain Sensitivity Questionnaire, negative affect, as assessed with the Beck Depression Inventory, and emotional dysregulation, as assessed with the Difficulties in Emotional regulation Scale. Age, biological sex, and current pain severity were included as covariates. The results support a moderated partial mediation model that explained 44% of the variance in emotional dysregulation. The findings indicate that negative affect is related to higher pain sensitivity across groups. Moreover, pain sensitivity partially mediated the association between negative affect and emotional dysregulation, but in opposite directions depending on AUD status. Among healthy controls, greater pain sensitivity was related to better emotional regulation, while greater pain sensitivity led to greater emotional dysregulation among individuals with AUD. The potential parallels in the underlying neurobiological mechanisms of emotionality, pain, and AUD suggest that interventions targeting pain may improve adaptive affect regulation skills, which in turn could reduce negative affect and its effect on pain sensitivity among individuals with AUD

Effects of pre- and post- natal exposure to flutamide on connexin 43 expression in testes and ovaries of prepubertal pigs

The aim of this study was to show whether connexin43 (C×43) expression in gonads is affected by an anti-androgen action. To perform this test, pigs were prenatally (on gestational days 20–28 and 80–88; GD20, GD80) and postnatally (on days 2–10 after birth; PD2) exposed to flutamide, which was given in five doses every second day and its effect was observed in prepubertal gilts and boars. Morphology and expression of C×43 was investigated in testes and ovaries by means of routine histology, immunohistochemistry, Western blotting, and RT-PCR. In boars exposed to flutamide varying degrees of seminiferous tubule abnormality, including reduced number of Sertoli cells, tubules with severely dilated lumina and multinucleated germ cells were observed, whereas in gilts, the administration of flutamide at GD20 resulted in delayed folliculogenesis. Only follicles at the preantral stage were observed. Qualitative analysis of immunohistochemical staining for C×43 was confirmed by quantitative image analysis, where the staining intensity was expressed as relative optical density of diaminobenzidine deposits. After flutamide exposure, statistically significant increase in C×43 signal intensity was observed between interstitial tissue of GD20 and control pigs (**P<0.01), between seminiferous tubules of PD2 and control boars (**P<0.01) and between theca cells of GD80, of PD2 and control gilts (**P<0.01). In contrast, statistically significant decrease in C×43 signal intensity was found between granulosa cells of GD20, of PD2 and control gilts (**P<0.01 and *P<0.05, respectively) and between theca cells of GD20 and control gilts (**P<0.01). Since we demonstrated changes in gonad morphology and in the expression of C×43 at the level of protein of prepubertal boars and gilts, it seems possible that flutamide, through blocking androgen action, causes delayed gonadal maturation in later postnatal life and, among other factors, may be involved in the regulation of C×43 gene expression in pig gonads

Substance use disorder status moderates the association between personality traits and problematic mobile phone/internet use

Background: Associations between personality traits and problematic smartphone use (PSU) among individuals with substance use disorder (SUD) have not been widely investigated. The current study aims to assess whether SUD status moderates the association between personality traits and PSU. Methods: The study group included 151 individuals with SUD and a normative sample (NS) comprised of 554 non-SUD students. The following self-report questionnaires were used: the Mobile Phone Problem Use Scale (MPPUS-10) to assess problematic smartphone use (PSU), the Internet Addiction Test (IAT) to assess intensity of internet use, and the NEO Five-Factor Inventory (NEO-FFI) to assess Personality traits. Results: SUD status moderated the association between neuroticism and openness to new experiences on PSU. That is, greater neuroticism and openness were significantly associated with more excessive PSU among the NS. In the SUD group, greater openness was a significant protective factor against PSU. Moderation results were similar when using the IAT (which was significantly correlated with MPPUS) as an outcome. Conclusions: The presence of SUD may influence how personality traits are associated with problematic mobile phone/internet use. Given that this is among one of the first studies examining this topic, findings should be replicated with additional studies

Application of Ni(II)-Assisted Peptide Bond Hydrolysis to Non-Enzymatic Affinity Tag Removal

In this study, we demonstrate a non-enzymatic method for hydrolytic peptide bond cleavage, applied to the removal of an affinity tag from a recombinant fusion protein, SPI2-SRHWAP-His6. This method is based on a highly specific Ni(II) reaction with (S/T)XHZ peptide sequences. It can be applied for the protein attached to an affinity column or to the unbound protein in solution. We studied the effect of pH, temperature and Ni(II) concentration on the efficacy of cleavage and developed an analytical protocol, which provides active protein with a 90% yield and ∼100% purity. The method works well in the presence of non-ionic detergents, DTT and GuHCl, therefore providing a viable alternative for currently used techniques

Progressive Purkinje Cell Degeneration in tambaleante Mutant Mice Is a Consequence of a Missense Mutation in HERC1 E3 Ubiquitin Ligase

The HERC gene family encodes proteins with two characteristic domains: HECT and RCC1-like. Proteins with HECT domains have been described to function as ubiquitin ligases, and those that contain RCC1-like domains have been reported to function as GTPases regulators. These two activities are essential in a number of important cellular processes such as cell cycle, cell signaling, and membrane trafficking. Mutations affecting these domains have been found associated with retinitis pigmentosa, amyotrophic lateral sclerosis, and cancer. In humans, six HERC genes have been reported which encode two subgroups of HERC proteins: large (HERC1-2) and small (HERC3-6). The giant HERC1 protein was the first to be identified. It has been involved in membrane trafficking and cell proliferation/growth through its interactions with clathrin, M2-pyruvate kinase, and TSC2 proteins. Mutations affecting other members of the HERC family have been found to be associated with sterility and growth retardation. Here, we report the characterization of a recessive mutation named tambaleante, which causes progressive Purkinje cell degeneration leading to severe ataxia with reduced growth and lifespan in homozygous mice aged over two months. We mapped this mutation in mouse chromosome 9 and then performed positional cloning. We found a G⇔A transition at position 1448, causing a Gly to Glu substitution (Gly483Glu) in the highly conserved N-terminal RCC1-like domain of the HERC1 protein. Successful transgenic rescue, with either a mouse BAC containing the normal copy of Herc1 or with the human HERC1 cDNA, validated our findings. Histological and biochemical studies revealed extensive autophagy associated with an increase of the mutant protein level and a decrease of mTOR activity. Our observations concerning this first mutation in the Herc1 gene contribute to the functional annotation of the encoded E3 ubiquitin ligase and underline the crucial and unexpected role of this protein in Purkinje cell physiology