Diverse Pathways Research Articles

Indigenous rights and ontological plurality in the institutional arrangements for the Waikato and Waipā Rivers in Aotearoa

ABSTRACT This paper analyses the institutional arrangements for the Waikato and Waipā Rivers in Aotearoa New Zealand to consider how effectively they promote Indigenous rights and the exercise of Māori law and relationships with place. We ask how these arrangements shape power relations and dynamics among different (human and non-human) actors and whether they foster relationality and create the enabling conditions that generate alternatives to modernist ways of governing. After examining the detail of these complex institutional arrangements in a way that exposes their ontological foundations, this paper argues that, despite limitations, particularly in relation to implementation, these arrangements operate to increase Iwi authority and, thus, promote Indigenous rights, and legal and ontological pluralism. This outcome demonstrates a vibrancy and plurality of thinking in relation to new models of law and institutional arrangements in settler-colonial contexts—beyond those grounded in rights of nature—and that there are a variety of pathways towards the realisation of Indigenous rights and authority, and the related promotion of legal and ontological pluralism.

Insight into selectivity of photocatalytic methane oxidation to formaldehyde on tungsten trioxide

Tungsten trioxide (WO3) has been recognized as the most promising photocatalyst for highly selective oxidation of methane (CH4) to formaldehyde (HCHO), but the origin of catalytic activity and the reaction manner remain controversial. Here, we take {001} and {110} facets dominated WO3 as the model photocatalysts. Distinctly, {001} facet can readily achieve 100% selectivity of HCHO via the active site mechanism whereas {110} facet hardly guarantees a high selectivity of HCHO along with many intermediate products via the radical way. In situ diffuse reflectance infrared Fourier transform spectroscopy, electron paramagnetic resonance and theoretical calculations confirm that the competitive chemical adsorption between CH4 and H2O and the different CH4 activation routes on WO3 surface are responsible for diverse CH4 oxidation pathways. The microscopic mechanism elucidation provides the guidance for designing high performance photocatalysts for selective CH4 oxidation.

Neuroprotective Effects of Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors (Gliflozins) on Diabetes-Induced Neurodegeneration and Neurotoxicity: A Graphical Review.

Diabetes is a chronic endocrine disorder that negatively affects various body systems, including the nervous system. Diabetes can cause or exacerbate various neurological disorders, and diabetes-induced neurodegeneration can involve several mechanisms such as mitochondrial dysfunction, activation of oxidative stress, neuronal inflammation, and cell death. In recent years, the management of diabetes-induced neurodegeneration has relied on several types of drugs, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, also called gliflozins. In addition to exerting powerful effects in reducing blood glucose, gliflozins have strong anti-neuro-inflammatory characteristics that function by inhibiting oxidative stress and cell death in the nervous system in diabetic subjects. This review presents the molecular pathways involved in diabetes-induced neurodegeneration and evaluates the clinical and laboratory studies investigating the neuroprotective effects of gliflozins against diabetes-induced neurodegeneration, with discussion about the contributing roles of diverse molecular pathways, such as mitochondrial dysfunction, oxidative stress, neuro-inflammation, and cell death. Several databases-including Web of Science, Scopus, PubMed, Google Scholar, and various publishers, such as Springer, Wiley, and Elsevier-were searched for keywords regarding the neuroprotective effects of gliflozins against diabetes-triggered neurodegenerative events. Additionally, anti-neuro-inflammatory, anti-oxidative stress, and anti-cell death keywords were applied to evaluate potential neuronal protection mechanisms of gliflozins in diabetes subjects. The search period considered valid peer-reviewed studies published from January 2000 to July 2023. The current body of literature suggests that gliflozins can exert neuroprotective effects against diabetes-induced neurodegenerative events and neuronal dysfunction, and these effects are mediated via activation of mitochondrial function and prevention of cell death processes, oxidative stress, and inflammation in neurons affected by diabetes. Gliflozins can confer neuroprotective properties in diabetes-triggered neurodegeneration, and these effects are mediated by inhibiting oxidative stress, inflammation, and cell death.

Constructing optimized framework with high structural reversibility and small volume shrinkage by Nd3+ substitution for Na3V2(PO4)3 cathode

Na3V2(PO4)3 (NVP) has been extensively researched as an ideal cathode material. However, the limitations of its structural stability and electronic conductivity have hindered its further applications. To address these challenges, this study proposes a modification strategy centered on the synergistic effects of Nd doping and carbon nanotubes (CNTs) coating. The Nd element shows a stronger affinity for oxygen. When replacing the V site, it can form a more stable Nd-O bond, meanwhile, it can inhibit the oxygen evolution. Furthermore, due to the super large ionic radius of Nd3+ (1.81 Å vs. 0.64 Å of V3+), the introduction of Nd doping serves to enhance the stability of the crystal structure, thereby ensuring the effective de-intercalation of Na+. Furthermore, Nd doping widens the transport channels, thereby increasing the speed of Na+ transport. Concurrently, the CNTs coating network, which is integrated onto the material surface, offers diverse pathways for electronic transport, significantly improving electronic conductivity. Comprehensively, Nd-3 sample shows the optimal performance at different doping gradients. It displays a reversible capacity of 114.8 mAh g−1 at 0.1 C. When cycling at 40 C, it can remain 90.2 % after 2500 cycles. According to the ex-situ XRD measurements, the Nd-3 sample shows favourable structural reversibility and very small volume shrinkage, indicating the significantly improved structural stability. Finally, the Nd-3//CHC full cell reveals a high capacity of 134.4 mAh g−1 at 0.1 C, indicating its great potential for applications.

Inhibited hypoxia-inducible factor by intraoperative hyperglycemia increased postoperative delirium of aged patients: A review.

The underlying mechanism of postoperative delirium (POD) in elderly people remains unclear. Perioperative hyperglycemia (POHG) is an independent risk indicator for POD, particularly in the elderly. Under cerebral desaturation (hypoxia) during general anesthesia, hypoxia-inducible factor (HIF) is neuroprotective during cerebral hypoxia via diverse pathways, like glucose metabolism and angiogenesis. Hyperglycemia can repress HIF expression and activity. On the other hand, POHG occurred among patients undergoing surgery. For surgical stress, hypothalamic-pituitary-adrenal activation and sympathoadrenal activation may increase endogenous glucose production via gluconeogenesis and glycogenolysis. Thus, under the setting of cerebral hypoxia during general anesthesia, we speculate that POHG prevents HIF-1α levels and function in the brain of aged patients, thus exacerbating the hypoxic response of HIF-1 and potentially contributing to POD. This paper sketches the underlying mechanisms of HIF in POD in elderly patients and offers novel insights into targets for preventing or treating POD in the same way as POHG.

High-frequency monitoring during rainstorm events reveals nitrogen sources and transport in a rural catchment

Rural areas lacking essential sewage treatment facilities and collection systems often experience eutrophication due to elevated nutrient loads. Understanding nitrogen (N) sources and transport mechanisms in rural catchments is crucial for improving water quality and mitigating downstream export loads, particularly during storm events. To further elucidate the sources, pathways, and transport mechanisms of N from a rural catchment with intensive agricultural activities during storm events, we conducted an analysis of 21 events through continuous sampling over two rainy seasons in a small rural catchment from the lower reaches of the Yangtze River. The results revealed that ammonia-N (NH4+-N) and nitrate-N (NO3−-N) exhibited distinct behaviors during rainstorm events, with NO3−-N accounting for the primary nitrogen loss, its load being approximately forty times greater than that of NH4+-N. Through examinations of the concentration-discharge (c-Q) relationships, the findings revealed that, particularly in prolonged rainstorms, NH4+-N exhibited source limited pattern (b = −0.13, P < 0.01), while NO3−-N displayed transport limited pattern (b = −0.21, P < 0.01). The figure-eight hysteresis pattern was prevalent for both NH4+-N and NO3−-N (38.1% and 52.0%, respectively), arising from intricate interactions among diverse sources and pathways. For NO3−-N, the hysteresis pattern shifted from clockwise under short-duration rainstorms to counter-clockwise under long-duration rainstorms, whereas hysteresis remained consistently clockwise for NH4+-N. The hysteresis analysis further suggests that the duration of rainstorms modifies hydrological connectivity, thereby influencing the transport processes of N. These insights provide valuable information for the development of targeted management strategies to reduce storm nutrient export in rural catchments.

Genomic Insights into Gestational Weight Gain: Uncovering Tissue-Specific Mechanisms and Pathways.

Increasing gestational weight gain (GWG) is linked to adverse outcomes in pregnant persons and their children. The Early Growth Genetics (EGG) Consortium identified previously genetic variants that could contribute to early, late, and total GWG from fetal and maternal genomes. However, the biologic mechanisms and tissue-Specificity of these variants in GWG is unknown. We evaluated the association between genetically predicted gene expression in five relevant maternal (subcutaneous and visceral adipose, breast, uterus, and whole blood) from GTEx (v7) and fetal (placenta) tissues and early, late, and total GWG using S-PrediXcan. We tested enrichment of pre-defined biological pathways for nominally (P < 0.05) significant associations using the GENE2FUNC module from Functional Mapping and Annotation of Genome-Wide Association Studies. After multiple testing correction, we did not find significant associations between maternal and fetal gene expression and early, late, or total GWG. There was significant enrichment of several biological pathways, including metabolic processes, secretion, and intracellular transport, among nominally significant genes from the maternal analyses (false discovery rate p-values: 0.016 to 9.37×10). Enriched biological pathways varied across pregnancy. Though additional research is necessary, these results indicate that diverse biological pathways are likely to impact GWG, with their influence varying by tissue and weeks of gestation.

Plasma-assisted NH3/air flame: Simultaneous LIF measurements of O and OH

In the emerging field of plasma-assisted ammonia (NH3) combustion, the evolution of key intermediate species has rarely been reported. This work establishes a simultaneous measurement system of laser-induced fluorescence (LIF) for hydroxyl (OH) and quantitative two-photon-absorption LIF for atomic oxygen (O), to explore the OH and O dynamics in an NH3/air flame affected by a nanosecond (ns) pulsed plasma discharge. Firstly, with the plasma on, the molar fraction of O is quantified to reach 8.7 × 10–3 in the burnt zone, about two orders of magnitude higher than that without plasma. In addition, the OH LIF signal intensity is four times higher, indicating a significant kinetic enhancement. Then, the spatial characteristics of OH and O are discussed and compared, showing remarkable discrepancy. The discrepancy between them indicates that O production is dominated by plasma kinetics, however, the OH production, primarily stemming from reactions between O and NH3/H2O, still depends on parameters associated with combustion kinetics. We further study the temporal dynamics of O and OH. It is concluded that O and OH peaks at 1.75 μs are mainly attributed to the pathway of quenching of the excited species. After that, O and OH start to decay but show significant differences between unburnt and burnt zones, which are characterized by a single-exponential decay and a bi-exponential decay, respectively. In the unburnt zone, the OH decay is much slower than the O decay due to the diverse pathways for OH production. In the burnt zone, the bi-exponential decay of O and OH can essentially be regarded as a process in which the NH3/air reactive system reaches chemical equilibrium. At this stage, the impacts of the excited species from the plasma gradually diminish and combustion kinetics dominates alone.

Leaf Endophytes Relationship with Host Metabolome Expression in Tropical Gymnosperms.

Plant-microbe interactions play a pivotal role in shaping host fitness, especially concerning chemical defense mechanisms. In cycads, establishing direct correlations between specific endophytic microbes and the synthesis of highly toxic defensive phytochemicals has been challenging. Our research delves into the intricate relationship between plant-microbe associations and the variation of secondary metabolite production in two closely related Zamia species that grow in distinct habitats; terrestrial and epiphytic. Employing an integrated approach, we combined microbial metabarcoding, which characterize the leaf endophytic bacterial and fungal communities, with untargeted metabolomics to test if the relative abundances of specific microbial taxa in these two Zamia species were associated with different metabolome profiles. The two species studied shared approximately 90% of the metabolites spanning diverse biosynthetic pathways: alkaloids, amino acids, carbohydrates, fatty acids, polyketides, shikimates, phenylpropanoids, and terpenoids. Co-occurrence networks revealed positive associations among metabolites from different pathways, underscoring the complexity of their interactions. Our integrated analysis demonstrated to some degree that the intraspecific variation in metabolome profiles of the two host species was associated with the abundance of bacterial orders Acidobacteriales and Frankiales, as well as the fungal endophytes belonging to the orders Chaetothyriales, Glomerellales, Heliotiales, Hypocreales, and Sordariales. We further associate individual metabolic similarity with four specific fungal endophyte members of the core microbiota, but no specific bacterial taxa associations were identified. This study represents a pioneering investigation to characterize leaf endophytes and their association with metabolomes in tropical gymnosperms, laying the groundwork for deeper inquiries into this complex domain.

Cell-type-specific consequences of mosaic structural variants in hematopoietic stem and progenitor cells

The functional impact and cellular context of mosaic structural variants (mSVs) in normal tissues is understudied. Utilizing Strand-seq, we sequenced 1,133 single-cell genomes from 19 human donors of increasing age, and discovered the heterogeneous mSV landscapes of hematopoietic stem and progenitor cells. While mSVs are continuously acquired throughout life, expanded subclones in our cohort are confined to individuals >60. Cells already harboring mSVs are more likely to acquire additional somatic structural variants, including megabase-scale segmental aneuploidies. Capitalizing on comprehensive single-cell micrococcal nuclease digestion with sequencing reference data, we conducted high-resolution cell-typing for eight hematopoietic stem and progenitor cells. Clonally expanded mSVs disrupt normal cellular function by dysregulating diverse cellular pathways, and enriching for myeloid progenitors. Our findings underscore the contribution of mSVs to the cellular and molecular phenotypes associated with the aging hematopoietic system, and establish a foundation for deciphering the molecular links between mSVs, aging and disease susceptibility in normal tissues.

Regulation of mitochondrial dysfunction by estrogens and estrogen receptors in Alzheimer's disease: A focused review.

Alzheimer's disease (AD) is a neurodegenerative disorder that primarily manifests itself by progressive memory loss and cognitive decline, thus significantly affecting memory functions and quality of life. In this review, we proceed from the understanding that the canonical amyloid-β hypothesis, while significant, has faced setbacks, highlighting the need to adopt a broader perspective considering the intricate interplay of diverse pathological pathways for effective AD treatments. Sex differences in AD offer valuable insights into a better understanding of its pathophysiology. Fluctuation of the levels of ovarian sex hormones during perimenopause is associated with changes in glucose metabolism, as a possible window of opportunity to further understand the roles of sex steroid hormones and their associated receptors in the pathophysiology of AD. We review these dimensions, emphasizing the potential of estrogen receptors (ERs) to reveal mitochondrial functions in the search for further research and therapeutic strategies for AD pharmacotherapy. Understanding and addressing the intricate interactions of mitochondrial dysfunction and ERs potentially pave the way for more effective approaches to AD therapy.

Identification of DPP-IV inhibitory peptides derived from buffalo colostrum: Mining through bioinformatics, in silico and in vitro approaches.

Bioactive peptides derived from foods provide physiological health benefits beyond nutrition. This study focused on profiling small peptide inhibitors against two key serine proteases, dipeptidyl peptidase-IV (DPP-IV) and prolyl oligopeptidase (POP). DPP-IV is a well-known protein involved in diverse pathways regulating inflammation, renal, cardiovascular physiology, and glucose homeostasis. POP is yet another key target protein for neurodegenerative disorders. The study evaluated peptide libraries of buffalo colostrum whey and fat globule membrane proteins derived from pepsin and pepsin-pancreatin digestion through in silico web tools and structure-based analysis by molecular docking and binding free-energy estimation, followed by in vitro assay for DPP-IV inhibition for the lead peptides. The bioinformatic study indicated 49 peptides presented motifs with DPP-IV inhibition while 5 peptides with sequences for POP inhibition. In the molecular docking interactions study, 22 peptides interacted with active site residues of DPP-IV and 3 peptides with that of POP. The synthesized peptides, SFVSEVPEL and LTFQHNF inhibited DPP-IV in vitro with an IC50 of 193.5 μM and 1.782 mM, respectively. The study revealed the key residues for inhibition of DPP-IV and POP thus affirming the DPP-IV inhibitory potential of milk-derived peptides.

Proteome Birthdating Reveals Age-Selectivity of Protein Ubiquitination

Within a cell, proteins have distinct and highly variable half-lives. As a result, the molecular ages of proteins can range from seconds to years. How the age of a protein influences its environmental interactions is a largely unexplored area of biology. To investigate the age-selectivity of cellular pathways, we developed a methodology termed “proteome birthdating” that barcodes proteins based on their time of synthesis. We demonstrate that this approach provides accurate measurements of protein turnover kinetics from a single biological sample encoding multiple labeling time-points. As a first application of the birthdated proteome, we investigated the age distribution of the human ubiquitinome. Our results indicate that the vast majority of ubiquitinated proteins in a cell consist of newly synthesized proteins and that these young proteins constitute the bulk of the degradative flux through the proteasome. Rapidly ubiquitinated nascent proteins are enriched in cytosolic subunits of large protein complexes. Conversely, proteins destined for the secretory pathway and vesicular transport have older ubiquitinated populations. Our data also identify a smaller subset of older ubiquitinated cellular proteins that do not appear to be targeted to the proteasome for rapid degradation. Together, our data provide an age census of the human ubiquitinome and establish proteome birthdating as a robust methodology for investigating the protein age-selectivity of diverse cellular pathways.

Activation of Inflammasomes and Relevant Modulators for the Treatment of Microglia-mediated Neuroinflammation in Ischemic Stroke.

As the brain's resident immune patrol, microglia mediate endogenous immune responses to central nervous system injury in ischemic stroke, thereby eliciting either neuroprotective or neurotoxic effects. The association of microglia-mediated neuroinflammation with the progression of ischemic stroke is evident through diverse signaling pathways, notably involving inflammasomes. Within microglia, inflammasomes play a pivotal role in promoting the maturation of interleukin-1β (IL-1β) and interleukin-18 (IL-18), facilitating pyroptosis, and triggering immune infiltration, ultimately leading to neuronal cell dysfunction. Addressing the persistent and widespread inflammation holds promise as a breakthrough in enhancing the treatment of ischemic stroke.

Clinical determinants of blood biomarkers of atrial cardiomyopathy: results from the ISOLATION AF ablation cohort study

Abstract Background In patients with atrial fibrillation (AF), significant advances have been made in identifying biomarkers representing diverse pathophysiological pathways, such as inflammation, myocyte injury, collagen deposition, and fatty-fibrotic infiltration. Data on clinical determinants of biomarkers in patients with AF, however, are lacking. Objective Our primary aim was to explore the relationships between clinical determinants and biomarker levels in AF patients scheduled for catheter ablation. Methods A cross-sectional analysis was conducted in AF patients undergoing catheter ablation included in the prospective multicenter ISOLATION study between July 2020 and May 2022. Clinical characteristics, routine tests and blood samples were collected before ablation. Blood samples were analyzed for known and novel cardiovascular biomarkers, including Bone morphogenetic protein 10 (BMP10), Angiopoietin-2 (Ang-2), Fibroblast growth factor 23 (FGF-23), Dickkopf-related protein 3 (DKK-3), Endocan (ESM-1), Insulin-like growth factor-binding protein 7 (IGFBP-7), B-type natriuretic peptides (proBNP, NTproBNP), High sensitive Troponin-T (hsTnT)&amp;lt; Growth differentiation factor 15 (GDF-15), interleukin 6 (IL-6), Fatty acid binding protein 3 (FABP3), Cancer antigen-125 (Ca-125) (Table 1). For each biomarker we trained a lasso regression model to identify the most important clinical determinants out of all the 60 available determinants (including anthropometry, ECG, comorbidities). The strongest associations are summarized in figure 1. Results Blood samples of 508 patients were analyzed. The mean age was 63 ±9 years, and 31.1% were female. 354 patients (69.7%) had paroxysmal AF and 154 patients (30.3%) had persistent AF. Heart failure was reported in 77 patients (15.2%). 355 (72.3%) patients were in sinus rhythm during sample collection. The following clinical determinants of biomarker levels were frequently identified as important: rhythm during blood phlebotomy, age, heart failure, decreased kidney function and female sex (Figure 1). Most notably, rhythm at the time of sampling was strongly associated with various biomarker levels. Female sex was positively associated with BMP10 and FGF23 (atrial fibrosis), but negatively associated with hsTNT (cardiac injury). Conclusion In patients with AF scheduled for catheter ablation, we identified several clinical determinants of biomarker levels with potential implications for disease mechanisms. In women, pro-fibrotic biomarkers were frequently higher, while male patients more often showed signs of myocardial injury. Importantly, rhythm during blood draw is a very strong determinant of many biomarkers and should be taken into account in future biomarker studies.Figure 1.Table 1.

Exploring Taurine's Potential in Alzheimer's Treatment: A Comprehensive Review.

Alzheimer's disease (AD) stands as one of the predominant neurodegenerative disorders, often culminating in dementia. Taurine, an endogenous amino acid, holds pivotal regulatory functions within the physiological milieu. Emerging evidence suggests that taurine may confer protection against the onset and progression of AD through diverse mechanistic pathways. This systematic review aims to comprehensively elucidate the multifaceted role of taurine in Alzheimer's disease.The primary objective is to assess taurine's potential as a preventative and therapeutic intervention for Alzheimer's, based on studies from 2004 to 2022. A rigorous search strategy was implemented, targeting English-language articles accessible in full text. Eligible studies were meticulously sourced from renowned databases including PubMed, PubMed Central, Science Direct, Cochrane Library, and Medline Plus. Inclusion criteria were limited to studies explicitly investigating the role of taurine in Alzheimer's disease. Our review encompasses a wealth of experimental studies conducted on murine models, collectively indicating taurine's capacity to ameliorate symptomatic presentations of Alzheimer's disease. Encouraged by these promising preclinical findings, the imperative for clinical trials in human subjects emerges. Taurine emerges as a prospective agent, offering potential mitigation of the cognitive and memory-related debility synonymous with Alzheimer's disease. This systematic review delineates a compelling body of evidence underscoring the putative neuroprotective role of taurine in Alzheimer's disease. However, it is incumbent upon the scientific community to bridge the translational gap through robust clinical investigations. Such endeavors hold promise in revolutionizing the therapeutic landscape for individuals grappling with the formidable challenges posed by Alzheimer's disease.

Dynamic Landscape of Higher Education, The Intersection of Student Skills and Industry Demand

In today's dynamic job market, higher education students are confronted with the challenge of sifting through numerous career options that align with their skills, interests, and educational background. To tackle this hurdle, "Dynamic Landscape Of Higher Education, The Intersection Of Students Skills And Industry Demand" introduces a personalized job recommendation system tailored explicitly for higher education students. This system utilizes advanced recommendation algorithms and data analysis techniques to provide students with targeted job suggestions based on their academic qualifications, skills, interests, and career preferences. With a user-friendly interface, students can effortlessly input their information and receive tailored recommendations that evolve over time through continuous learning from user feedback. By offering data-driven insights and facilitating informed career decisions, this system empowers students to explore diverse career pathways and seamlessly transition from education to employment. The user interface of this system is designed to be intuitive and user-friendly, enabling students to easily input their information and preferences to receive tailored job recommendations. The recommendation system is adaptive, continuously learning from user feedback and interaction, ensuring that the recommendations provided evolve over time to better meet the changing needs and preferences of students. Recognizing the widening gap between industry requirements and graduating students' skills, this project proposes a comprehensive job recommendation system to bridge this divide and enhance placement opportunities. Leveraging advanced algorithms and machine learning techniques, the system evaluates students' skill sets and matches them with relevant job roles, facilitating a smooth transition from academia to the workforce. This multifaceted approach includes data collection, algorithm development, user interface design, and integration with existing campus placement systems. Collaborative efforts with academic institutions and industry partners aim to provide personalized job recommendations tailored to individual students' abilities and aspirations, with a focus on fairness and equity. Key components of the project include the design and implementation of an intuitive user interface, data-driven skill assessment methodologies, and continuous refinement of the recommendation algorithm based on user feedback and industry insights. Ethical considerations regarding data privacy and security are carefully addressed, reflecting a commitment to responsible use of student data. Ultimately, the success of the job recommendation system is measured by its ability to match students with suitable employment opportunities and its broader impact on career readiness and long-term professional success. By empowering students with the tools and resources needed to navigate the complexities of the modern job market, this project aims to catalyze positive change and foster a more inclusive and equitable future for all stakeholders involved.

Untargeted metabolomics and metagenomics reveal signatures for intramammary ceftiofur treatment and lactation stage in the cattle hindgut.

The gut microbiota in cattle is essential for protein, energy, and vitamin production and hence, microbiota perturbations can affect cattle performance. This study evaluated the effect of intramammary (IMM) ceftiofur treatment and lactation stage on the functional gut microbiome and metabolome. Forty dairy cows were enrolled at dry-off. Half received IMM ceftiofur and a non-antibiotic teat sealant containing bismuth subnitrate (cases), while the other half received the teat sealant (controls). Fecal samples were collected before treatment at dry off, during the dry period (weeks 1 and 5) and the first week after calving (week 9). Shotgun metagenomic sequencing was applied to predict microbial metabolic pathways whereas untargeted metabolomics was used identify polar and nonpolar metabolites. Compared to controls, long-term changes were observed in the cows given ceftiofur, including a lower abundance of microbial pathways linked to energy production, amino acid biosynthesis, and other vital molecules. The metabolome of treated cows had elevated levels of stachyose, phosphatidylethanolamine diacylglycerol (PE-DAG), and inosine a week after the IMM ceftiofur application, indicating alterations in microbial fermentation, lipid metabolism, energy, and cellular signaling. Differences were also observed by sampling, with cows in late lactation having more diverse metabolic pathways and a unique metabolome containing higher levels of histamine and histamine-producing bacteria. These data illustrate how IMM ceftiofur treatment can alter the functionality of the hindgut metabolome and microbiome. Understanding how antibiotics and lactation stages, which are each characterized by unique diets and physiology, impact the function of resident microbes is critical to define normal gut function in dairy cattle.

Detection of Sulfoquinovosidase Activity in Cell Lysates Using Activity‐Based Probes

AbstractThe sulfolipid sulfoquinovosyl diacylglycerol (SQDG), produced by plants, algae, and cyanobacteria, constitutes a major sulfur reserve in the biosphere. Microbial breakdown of SQDG is critical for the biological utilization of its sulfur. This commences through release of the parent sugar, sulfoquinovose (SQ), catalyzed by sulfoquinovosidases (SQases). These vanguard enzymes are encoded in gene clusters that code for diverse SQ catabolic pathways. To identify, visualize and isolate glycoside hydrolase CAZY‐family 31 (GH31) SQases in complex biological environments, we introduce SQ cyclophellitol‐aziridine activity‐based probes (ABPs). These ABPs label the active site nucleophile of this enzyme family, consistent with specific recognition of the SQ cyclophellitol‐aziridine in the active site, as evidenced in the 3D structure of Bacillus megaterium SQase. A fluorescent Cy5‐probe enables visualization of SQases in crude cell lysates from bacteria harbouring different SQ breakdown pathways, whilst a biotin‐probe enables SQase capture and identification by proteomics. The Cy5‐probe facilitates monitoring of active SQase levels during different stages of bacterial growth which show great contrast to more traditional mRNA analysis obtained by RT‐qPCR. Given the importance of SQases in global sulfur cycling and in human microbiota, these SQase ABPs provide a new tool with which to study SQase occurrence, activity and stability.

Detection of Sulfoquinovosidase Activity in Cell Lysates Using Activity-Based Probes.

The sulfolipid sulfoquinovosyl diacylglycerol (SQDG), produced by plants, algae, and cyanobacteria, constitutes a major sulfur reserve in the biosphere. Microbial breakdown of SQDG is critical for the biological utilization of its sulfur. This commences through release of the parent sugar, sulfoquinovose (SQ), catalyzed by sulfoquinovosidases (SQases). These vanguard enzymes are encoded in gene clusters that code for diverse SQ catabolic pathways. To identify, visualize and isolate glycoside hydrolase CAZY-family 31 (GH31) SQases in complex biological environments, we introduce SQ cyclophellitol-aziridine activity-based probes (ABPs). These ABPs label the active site nucleophile of this enzyme family, consistent with specific recognition of the SQ cyclophellitol-aziridine in the active site, as evidenced in the 3D structure of Bacillus megaterium SQase. A fluorescent Cy5-probe enables visualization of SQases in crude cell lysates from bacteria harbouring different SQ breakdown pathways, whilst a biotin-probe enables SQase capture and identification by proteomics. The Cy5-probe facilitates monitoring of active SQase levels during different stages of bacterial growth which show great contrast to more traditional mRNA analysis obtained by RT-qPCR. Given the importance of SQases in global sulfur cycling and in human microbiota, these SQase ABPs provide a new tool with which to study SQase occurrence, activity and stability.