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Hydrogen Sulfide and Protein Persulfidation in Plant Stress Signaling
No full textHydrogen sulfide (H2S) is increasingly recognized as a crucial signaling molecule in plants, playing key roles in regulating physiological processes and enhancing stress tolerance. This review provides an updated summary of H2S signaling in plant stress responses, discussing its uptake from external environmental sources, its endogenous biosynthesis, and its broader functions in stress adaptation. We summarize the impact of H2S on plants under various stress conditions and review the mechanisms through which it mediates signaling functions, with a particular focus on H2S-mediated protein persulfidation. Additionally, we provide an overview of the current understanding of protein persulfidation in regulating physiological processes and stress responses in plants, offering both a general discussion of its effects under different stress conditions and specific examples to highlight its significance. Finally, we review recent proteomic studies on protein persulfidation in plants, comparing the identified persulfidated proteins across studies and highlighting shared biological processes and pathways. This review aims to consolidate the current understanding of H2S signaling and its roles mediated by protein persulfidation in plants, while also offering insights to inspire future research in this rapidly evolving field.Hydrogen sulfide (H2S) is increasingly recognized as a crucial signaling molecule in plants, playing key roles in regulating physiological processes and enhancing stress tolerance. This review provides an updated summary of H2S signaling in plant stress responses, discussing its uptake from external environmental sources, its endogenous biosynthesis, and its broader functions in stress adaptation. We summarize the impact of H2S on plants under various stress conditions and review the mechanisms through which it mediates signaling functions, with a particular focus on H2S-mediated protein persulfidation. Additionally, we provide an overview of the current understanding of protein persulfidation in regulating physiological processes and stress responses in plants, offering both a general discussion of its effects under different stress conditions and specific examples to highlight its significance. Finally, we review recent proteomic studies on protein persulfidation in plants, comparing the identified persulfidated proteins across studies and highlighting shared biological processes and pathways. This review aims to consolidate the current understanding of H2S signaling and its roles mediated by protein persulfidation in plants, while also offering insights to inspire future research in this rapidly evolving field.
Yeyi : a phylogenetic loner in Eastern Bantu
No full textWhile major advances in the subclassification of Bantu languages have been made thanks to comprehensive, lexicon-based classifications, there are still several important uncertainties obscuring not only the diachronic linguistic processes that gave rise to Bantu diversification, but also the population dynamics of ancestral Bantu speakers underlying them. In this paper, we address one of these persisting mysteries of Bantu genealogy, i.e., the unclassified Yeyi (R41) language of southern Africa. While the Bantu origin of Yeyi is straightforward and undisputed, its closest relatives are unknown, as is the major Bantu branch to which it belongs. We use a lexicon-based, Bayesian phylogenetic approach, comparing Yeyi to languages of the wider geographic region, including even more far-flung languages that have previously been hypothesized to bear a close relationship to Yeyi. The resultant linguistic phylogeny shows that Yeyi is part of the Wider Eastern Bantu branch as its own clade with Narrow Eastern Bantu languages as its closest relatives and none of its nearest neighbors. We argue that this relatively isolated position of Yeyi within Eastern Bantu suggests an early migration into southern Africa from the putative Wider Eastern Bantu homeland, which was followed by the loss of Yeyi’s putative earlier sister languages, presumably through a shift to Bantu languages spoken by more recent migrants.While major advances in the subclassification of Bantu languages have been made thanks to comprehensive, lexicon-based classifications, there are still several important uncertainties obscuring not only the diachronic linguistic processes that gave rise to Bantu diversification, but also the population dynamics of ancestral Bantu speakers underlying them. In this paper, we address one of these persisting mysteries of Bantu genealogy, i.e., the unclassified Yeyi (R41) language of southern Africa. While the Bantu origin of Yeyi is straightforward and undisputed, its closest relatives are unknown, as is the major Bantu branch to which it belongs. We use a lexicon-based, Bayesian phylogenetic approach, comparing Yeyi to languages of the wider geographic region, including even more far-flung languages that have previously been hypothesized to bear a close relationship to Yeyi. The resultant linguistic phylogeny shows that Yeyi is part of the Wider Eastern Bantu branch as its own clade with Narrow Eastern Bantu languages as its closest relatives and none of its nearest neighbors. We argue that this relatively isolated position of Yeyi within Eastern Bantu suggests an early migration into southern Africa from the putative Wider Eastern Bantu homeland, which was followed by the loss of Yeyi’s putative earlier sister languages, presumably through a shift to Bantu languages spoken by more recent migrants.A
Report of RILEM TC 281-CCC : phase assemblage alterations and carbonation potential of mortar with blended cements induced by long duration carbonation exposure
No full textReplacement of Portland cement is a practical strategy to reduce concrete manufacturing CO2 emissions. However, this approach typically results in a diminished portlandite content in the hardened mix, elevating the risk of carbonation-induced corrosion in steel-reinforced concrete. Carbonation is frequently studied by exposing the samples to elevated CO2 levels (1% and 20%). However, the carbonation process and its by-products might differ markedly under natural conditions. In the context of RILEM TC 281-CCC 'Carbonation of Concrete with SCMs', a comprehensive three-year natural carbonation study on mortar samples was carried out across three laboratories. Samples were made with commercially available cement (CEM I, CEM II/B-V, CEM III/B). This study examined two natural carbonation scenarios: one in a regulated climate chamber and the other outdoors, protected from direct rainfall. The progression of carbonation was determined using a phenolphthalein indicator and compared to optical pH measurements. The phase composition was analysed by X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, and thermogravimetric analysis. Additionally, the CO2 capture in three-year-old naturally carbonated samples was assessed and contrasted against the reactive CaO content. The thermogravimetric analysis data revealed a non-linear relationship between the portlandite content in the uncarbonated zone and the carbonation rate. A reduced clinker content leads to lower pH values in carbonated and uncarbonated zones. Notably, samples containing CEM II displayed the largest formation of CaCO3 which, divided by the theoretical maximum amount of CaCO3 from reactive CaO, signifies the highest degree of carbonation among the cement types studied.Replacement of Portland cement is a practical strategy to reduce concrete manufacturing CO2 emissions. However, this approach typically results in a diminished portlandite content in the hardened mix, elevating the risk of carbonation-induced corrosion in steel-reinforced concrete. Carbonation is frequently studied by exposing the samples to elevated CO2 levels (1% and 20%). However, the carbonation process and its by-products might differ markedly under natural conditions. In the context of RILEM TC 281-CCC 'Carbonation of Concrete with SCMs', a comprehensive three-year natural carbonation study on mortar samples was carried out across three laboratories. Samples were made with commercially available cement (CEM I, CEM II/B-V, CEM III/B). This study examined two natural carbonation scenarios: one in a regulated climate chamber and the other outdoors, protected from direct rainfall. The progression of carbonation was determined using a phenolphthalein indicator and compared to optical pH measurements. The phase composition was analysed by X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, and thermogravimetric analysis. Additionally, the CO2 capture in three-year-old naturally carbonated samples was assessed and contrasted against the reactive CaO content. The thermogravimetric analysis data revealed a non-linear relationship between the portlandite content in the uncarbonated zone and the carbonation rate. A reduced clinker content leads to lower pH values in carbonated and uncarbonated zones. Notably, samples containing CEM II displayed the largest formation of CaCO3 which, divided by the theoretical maximum amount of CaCO3 from reactive CaO, signifies the highest degree of carbonation among the cement types studied.A
Acute heat stress exposure leads to negative modulation of testicular proteome
No full textHeat stress exposure (HS) impairs testicular function inmouse models. Chronologically, major changes are observedat 14 d post-exposure, impacting forming spermatids at the timeof HS. We investigated the impact of acute HS exposure ontesticular proteome. Adult C57Bl6-elite mice (n=3/group)were sedated, and the lower portion of the body was immersedin water at 40 ºC (treatment) or 37 ºC (control) for 20 min. At 0h (control), 7 and 14 d post-HS, mice were euthanized andsamples collected. After fixation in Bouin’s, testes were subjected to histological preparation in paraffin blocks. For proteinextraction, five sections of 10 µm were obtained from eachsample. The tissue fragments were retrieved from the paraffin(xylene, alcohol 100, 90, and 70%), sonicated (10x/30 s, 1 minbreak), and centrifuged at 10,000 x g/30 min/4 ºC. Thesupernatant was collected and prepared for gel-electrophoresis(50 µg protein/sample). The run was stopped when the samplesreached the separation gel. Then, the gel was stained withcolloidal Coomassie and bands were cut and trypsinized. Massspectrometry was performed (ESI-Q-TOF MS/MS). Spectra wereacquired using MassLynx v.4.1 software and converted intoMascot Distiller v.2.3.2.0 software, 2009 (Matrix Science Ltd) toobtain relative quantification of each protein in the mixture byexponentially modified protein abundance index (emPAI).Protein identification was conducted via UniprotKB database(www.uniprot.org.br), in the Mus musculus taxonomy. Resultswere analyzed in MetaboAnalyst 6.0. Importantly, 20 proteinspresented alpha > 1 based on VIP score. From the differentiallyabundant proteins, 4 should be highlighted between moments:CHCHD3, important for mitochondrial stabilization, was upregulated at 7 and 14 d (FDR 1 based on VIP score. From the differentiallyabundant proteins, 4 should be highlighted between moments:CHCHD3, important for mitochondrial stabilization, was upregulated at 7 and 14 d (FDR<0.05) when compared to control(FDR<0.05), whereas DNAH12, a dynein fundamental forflagellar movement; USP1, protective against DNA damageand Rpl30, a ribosomal component and marker of spermmorphology and motility were downregulated at 7 and 14 d(FDR<0.05). There was clear modulation of protein profiles ofmouse testes post-HS exposure, consistent with literature thatdescribes impaired sperm movement and reduced DNA integrity following a HS event.C
Association between poor drug adherence and undernutrition among adult HIV patients in southern Ethiopia: an institution based cross sectional study
No full textObjectiveUndernutrition is a common issue for HIV and other immune suppressed patients. Approximately 462 million people worldwide living with HIV are experiencing undernutrition, with sub-Saharan Africa having the highest prevalence. Good adherence to antiretroviral therapy (ART) indirectly helps prevent undernutrition by suppressing viral load, increasing CD4 count, preventing viral resistance, enhancing immune reconstitution and delaying disease progression in HIV patients. This study aims to assess the association between poor drug adherence and undernutrition among adult HIV patients in southern Ethiopia.Study designAn institution based cross sectional study design was used.Setting and participantsThe study was conducted in 406 randomly selected adult HIV patients from Gamo zone public health facilities.Primary and secondary outcomesThe data were collected by a trained data collector using a structured interviewer administered questionnaire, patient record review and physical measurements. Binary logistic regression was run to select candidate variables, and a multivariable logistic regression model was used to assess the association between undernutrition and poor drug adherence, as well as other variables. A p value <0.05 with 95% CI was considered statistically significant.ResultsThe magnitude of undernutrition was 28% (95% CI 24.0 to 33). Being a male patient (AOR 2.0, 95% CI 1.243 to 3.573), poor ART drug adherence (AOR 3.6, 1.815 to 7.428) and consuming <5 food groups (AOR 4.8, 2.901 to 8.265) were significantly associated with undernutrition among adult HIV patients.ConclusionsPoor drug adherence was significantly associated with undernutrition. Also, sex and dietary diversity were identified as predictors for undernutrition among adult HIV patients. Therefore, effectively managing poor drug adherence, nutritional supplements and communicating behavioural change implications are critical for successfully preventing undernutrition.ObjectiveUndernutrition is a common issue for HIV and other immune suppressed patients. Approximately 462 million people worldwide living with HIV are experiencing undernutrition, with sub-Saharan Africa having the highest prevalence. Good adherence to antiretroviral therapy (ART) indirectly helps prevent undernutrition by suppressing viral load, increasing CD4 count, preventing viral resistance, enhancing immune reconstitution and delaying disease progression in HIV patients. This study aims to assess the association between poor drug adherence and undernutrition among adult HIV patients in southern Ethiopia.Study designAn institution based cross sectional study design was used.Setting and participantsThe study was conducted in 406 randomly selected adult HIV patients from Gamo zone public health facilities.Primary and secondary outcomesThe data were collected by a trained data collector using a structured interviewer administered questionnaire, patient record review and physical measurements. Binary logistic regression was run to select candidate variables, and a multivariable logistic regression model was used to assess the association between undernutrition and poor drug adherence, as well as other variables. A p value <0.05 with 95% CI was considered statistically significant.ResultsThe magnitude of undernutrition was 28% (95% CI 24.0 to 33). Being a male patient (AOR 2.0, 95% CI 1.243 to 3.573), poor ART drug adherence (AOR 3.6, 1.815 to 7.428) and consuming <5 food groups (AOR 4.8, 2.901 to 8.265) were significantly associated with undernutrition among adult HIV patients.ConclusionsPoor drug adherence was significantly associated with undernutrition. Also, sex and dietary diversity were identified as predictors for undernutrition among adult HIV patients. Therefore, effectively managing poor drug adherence, nutritional supplements and communicating behavioural change implications are critical for successfully preventing undernutrition.
Multi-physics microstructural modeling of a carbon steel pipe failure in sour gas service
No full textThis study presents a comprehensive failure analysis of an ASTM A106B steel pipe exposed to sour natural gas, focusing on degradation and cracking mechanisms. A range of experimental methodologies, including visual inspection, chemical spot tests, XRD analysis, SEM-EDS examination, metallographic analysis, and hardness testing, were employed to identify critical material deficiencies. The findings indicate that environmentally assisted cracking (EAC) initiated at the pipe's outer diameter (OD) and propagated inward. The experiments also revealed a hardness gradient across the pipe's thickness and a non-uniform distribution of microstructural inclusions. Additionally, a coupled chemo-mechano-damage finite element analysis (FEA) was conducted to simulate crack propagation driven by hydrogen embrittlement. The FEA used a phase-field approach to model interactions between hydrogen diffusion, mechanical stresses, and microstructural features such as non-uniform inclusion distribution and varying hardness across the pipe wall. The simulations successfully mimicked the crack growth path under sulphide stress cracking (SSC) conditions, demonstrating the influence of material inhomogeneity. The results confirmed that failure initiated at the OD and propagated inward due to hydrogen accumulation at inclusions. These inclusions caused higher gradients of hydrostatic stress, accelerating hydrogen accumulation and crack initiation in regions with a higher inclusion density. Regions of higher hardness were particularly susceptible to failure, as they exhibit lower fracture toughness, which is further degraded by hydrogen diffusion, accelerating the failure process. This study highlights the critical role of microstructural heterogeneities and hydrogen embrittlement in pipeline failure and suggests that the methods presented can be applied to pipelines in hydrogen blending or pure hydrogen transmission, offering key insights for improving material selection and design for pipelines in sour gas and hydrogen environments.This study presents a comprehensive failure analysis of an ASTM A106B steel pipe exposed to sour natural gas, focusing on degradation and cracking mechanisms. A range of experimental methodologies, including visual inspection, chemical spot tests, XRD analysis, SEM-EDS examination, metallographic analysis, and hardness testing, were employed to identify critical material deficiencies. The findings indicate that environmentally assisted cracking (EAC) initiated at the pipe's outer diameter (OD) and propagated inward. The experiments also revealed a hardness gradient across the pipe's thickness and a non-uniform distribution of microstructural inclusions. Additionally, a coupled chemo-mechano-damage finite element analysis (FEA) was conducted to simulate crack propagation driven by hydrogen embrittlement. The FEA used a phase-field approach to model interactions between hydrogen diffusion, mechanical stresses, and microstructural features such as non-uniform inclusion distribution and varying hardness across the pipe wall. The simulations successfully mimicked the crack growth path under sulphide stress cracking (SSC) conditions, demonstrating the influence of material inhomogeneity. The results confirmed that failure initiated at the OD and propagated inward due to hydrogen accumulation at inclusions. These inclusions caused higher gradients of hydrostatic stress, accelerating hydrogen accumulation and crack initiation in regions with a higher inclusion density. Regions of higher hardness were particularly susceptible to failure, as they exhibit lower fracture toughness, which is further degraded by hydrogen diffusion, accelerating the failure process. This study highlights the critical role of microstructural heterogeneities and hydrogen embrittlement in pipeline failure and suggests that the methods presented can be applied to pipelines in hydrogen blending or pure hydrogen transmission, offering key insights for improving material selection and design for pipelines in sour gas and hydrogen environments.A
Positive affect regulation and depressive symptoms in hospitalized patients with bipolar disorder
No full textBackground Bipolar disorder (BD) is characterized by alternating mood episodes, with individuals often experiencing heightened positive emotions. This study investigated strategies for regulating positive emotions-amplification and dampening-and their association with depressive symptoms and childhood trauma. Methods This longitudinal case-control study included 49 hospitalized BD patients (73% BD-I) and 24 matched healthy controls (HCs). At baseline, participants completed the Responses to Positive Affect questionnaire and the Childhood Trauma Questionnaire - Short Form, with mood assessments every two weeks. Group differences and interrelations were analyzed using t-tests, ANCOVAs, and Pearson correlations. Linear mixed models examined the longitudinal impact of positive affect regulation on depressive symptoms. Results BD patients showed significantly higher dampening than HCs, while positive rumination strategies were similar between groups. Dampening correlated with more exposure to childhood trauma, particularly emotional abuse, but did not predict changes in depressive symptoms during hospitalization. Emotion-focused positive rumination was inversely related to depressive symptoms but had no longitudinal effect. Conclusions Hospitalized BD patients used more dampening than HCs, which is linked to more childhood trauma exposure. Positive rumination strategies were comparable and showed limited impact on depressive symptoms. Further research is needed to clarify the clinical role of these affect regulation strategies in BD management.Background Bipolar disorder (BD) is characterized by alternating mood episodes, with individuals often experiencing heightened positive emotions. This study investigated strategies for regulating positive emotions-amplification and dampening-and their association with depressive symptoms and childhood trauma. Methods This longitudinal case-control study included 49 hospitalized BD patients (73% BD-I) and 24 matched healthy controls (HCs). At baseline, participants completed the Responses to Positive Affect questionnaire and the Childhood Trauma Questionnaire - Short Form, with mood assessments every two weeks. Group differences and interrelations were analyzed using t-tests, ANCOVAs, and Pearson correlations. Linear mixed models examined the longitudinal impact of positive affect regulation on depressive symptoms. Results BD patients showed significantly higher dampening than HCs, while positive rumination strategies were similar between groups. Dampening correlated with more exposure to childhood trauma, particularly emotional abuse, but did not predict changes in depressive symptoms during hospitalization. Emotion-focused positive rumination was inversely related to depressive symptoms but had no longitudinal effect. Conclusions Hospitalized BD patients used more dampening than HCs, which is linked to more childhood trauma exposure. Positive rumination strategies were comparable and showed limited impact on depressive symptoms. Further research is needed to clarify the clinical role of these affect regulation strategies in BD management.A
