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Abstract The bioavailable nitrogen fixed by diazotrophs is critical for sustaining productivity in the oligotrophic ocean. Despite this, understanding how diazotroph-derived nitrogen integrates into the nitrogen cycle within the euphotic zone remains unknown. Here, we investigated nitrogen fixation rates in the particulate and dissolved fractions within the euphotic zone of the North Pacific Subtropical Gyre. Our findings reveal the proportion of nitrogen fixation rates in the dissolved fraction increases with depth. Light manipulation experiments uncover that reduced light levels can stimulate the net release of diazotroph-derived nitrogen, aligning with our depth-related observations. Furthermore, we identify two distinct transfer pathways vertically associated with light-driven ecological niches. Specifically, the released diazotroph-derived nitrogen is transferred to non-diazotrophic plankton in the upper layers. Meanwhile, in the lower layers, it contributes to the nitrification process. Our results underscore the high bioavailability of diazotroph-derived nitrogen and its rapid integration into the nitrogen cycle through multiple pathways within the well-lit ocean.

Abstract The heavily human-perturbed coastal oceans are hotspots of nitrous oxide (N2O) emission to the atmosphere. The processes underpinning the N2O flux, however, remain poorly understood, leading to large uncertainties in assessing global N2O budgets. Using a suite of nitrogen isotope labeling experiments, we show that multiple processes contribute to N2O production throughout the estuarine-coastal gradient, sustaining intensive N2O flux to the atmosphere. Unexpectedly, denitrification, rather than ammonia oxidation as previously assumed, constitutes the major source of N2O in well-oxygenated coastal waters. Size-fractionated manipulation experiments with gene analysis further reveal niche partitioning of ammonia oxidizers and denitrifiers across the particle size spectrum; denitrification dominated on large particles and ammonia oxidizers on small particles. Total N2O production rate increases with substrate and particle concentrations, suggesting a crucial interplay between nutrients and particles in controlling N2O production. The controlling factors identified here may help understand climate feedback mechanisms between human activity and coastal oceans.

Abstract Fish are vital in river ecosystems; however, traditional investigations of fish usually cause ecological damage. Extracting DNA from aquatic environments and identifying DNA sequences offer an alternative, noninvasive approach for detecting fish species. In this study, the effects of environmental DNA (eDNA), coupled with PCR and next‐generation sequencing, and electrofishing for identifying fish community composition and diversity were compared. In three subtropical rivers of southern China, fish specimens and eDNA in water were collected along the longitudinal (upstream–downstream) gradient of the rivers. Both fish population parameters, including species abundance and biomass, and eDNA OTU richness grouped 38 sampling sites into eight spatial zones with significant differences in local fish community composition. Compared with order‐/family‐level grouping, genus‐/species‐level grouping could more accurately reveal the differences between upstream zones I−III, midstream zones IV−V, and downstream zones VI–VIII. From the headwaters to the estuary, two environmental gradients significantly influenced the longitudinal distribution of the fish species, including the first gradient composed of habitat and physical water parameters and the second gradient composed of chemical water parameters. The high regression coefficient of alpha diversity between eDNA and electrofishing methods as well as the accurate identification of dominant, alien, and biomarker species in each spatial zone indicated that eDNA could characterize fish community attributes at a level similar to that of traditional approaches. Overall, our results demonstrated that eDNA metabarcoding can be used as an effective tool for revealing fish composition and diversity, which is important for using the eDNA technique in aquatic field monitoring.

Introduction: The Copenhagen Burnout Inventory (CBI) is a recent burnout measure with a focus on fatigue and exhaustion. It has three factors: personal burnout, work-related burnout, and client-related burnout. This study aimed to translate the CBI into the Malay language and to validate the translated version among a group of medical students. Methods: The forward–backward translation was performed as per standard guidelines. The Malay version of CBI (CBI-M) was distributed to 32 medical students to assess face validity and later to 452 medical students to assess construct validity. The data analysis was performed by Microsoft Excel, SPSS and AMOS. Results: The face validity index of CBI-M was more than 0.8. The three factors of CBI-M achieved good levels of goodness-of-fit indices (Cmin/df = 2.99, RMSEA = 0.066, GFI = 0.906, CFI = 0.938, NFI = 0.910, TLI = 0.925). The composite reliability values of the three factors ranged from 0.84 to 0.87. The Cronbach's alpha values of the three factors ranged from 0.83 to 0.87. Conclusions: This study supports the face and construct validity of the CBI-M with a high internal consistency.

In this work, we present mechanical spectroscopy of cold work tool steel subjected to sub-zero cryogenic soaking treatment to reveal the carbon segregation and the subsequent carbides refinement. The maximum of Snoek-Köster (SK) peak height was obtained in the sample subjected to soaking 1h at −130°C cryogenic treatment. The SK peak height is reduced with prolonging the soaking time. The results indicate that an increase in the height of SK peak is connected with an increase in dislocation density and the number of segregated carbon atoms in the vicinity of dislocations or twin planes after martensite transformation at −130°C which is confirmed by corresponding TEM and atom probe tomography measurement. Hence, it is suggested that the isothermal martensite, formed during the cryogenic soaking treatment decreases (APT) the height of SK peak.

Objective: Adhesions between the uterus, bladder and anterior abdominal wall are associated with clinical sequelae, including chronic pelvic pain and dyspareunia, and can also yield complications during surgery. The transvaginal sonographic (TVS) sliding bladder sign is a minimally invasive diagnostic tool to evaluate the presence of vesicouterine adhesions. This study aimed to determine the predictive value and intra‐ and interobserver variation of the TVS sliding bladder sign in the assessment of vesicouterine adhesions. Methods: This was a prospective observational double‐blind diagnostic accuracy study conducted at the Amsterdam University Medical Center. Patients scheduled for gynecological laparoscopic surgery for a benign disorder between January 2020 and December 2022 were included consecutively. All patients underwent preoperative TVS, including a dynamic sliding bladder sign examination in our outpatient clinic. Videoclips of the TVS scans were stored for offline assessment and used as an index test. The recordings of both TVS and laparoscopy were evaluated for diagnostic characteristics of vesicouterine adhesions by independent assessors, who were blinded to the clinical situation in addition to the laparoscopic findings when assessing recordings of TVS and vice versa. The presence of adhesions on laparoscopy was used as the reference standard. The positive predictive value (PPV), negative predictive value (NPV), specificity and sensitivity of the sliding bladder sign were calculated. In addition, inter‐ and intraobserver variability of the sliding bladder sign on TVS were assessed. Results: Of 116 included women, 57 had a negative sliding bladder sign on TVS, while on laparoscopy, 51 women had mild and 28 had severe vesicouterine adhesions. A negative sliding bladder sign had a PPV of 94.7% (95% CI, 88.9–100%) for the presence of any vesicouterine adhesions, and a positive sliding bladder sign had a specificity of 91.9% (95% CI, 83.1–100%). For severe adhesions, the negative sliding bladder sign had a sensitivity of 89.3% (95% CI, 77.8–100%) and a positive sliding bladder sign had a NPV of 94.9% (95% CI, 89.3–100%). When using Cohen's kappa coefficient, inter‐ and intraobserver agreement between assessors was good. Conclusions: Sliding bladder sign evaluation using TVS is a reliable diagnostic tool for the prediction of vesicouterine adhesions on laparoscopy. A negative sliding bladder sign indicates the presence of vesicouterine adhesions, while a positive sliding bladder sign makes the presence of severe adhesions unlikely. Establishing vesicouterine adhesions by TVS may optimize preoperative planning, and can be used for future studies to evaluate the relationship between symptomatology and vesicouterine adhesions and, subsequently, the effect of adhesion‐prevention interventions. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

The bioavailable nitrogen fixed by diazotrophs is critical for sustaining productivity in the oligotrophic ocean. Despite this, understanding how diazotroph-derived nitrogen integrates into the nitrogen cycle within the euphotic zone remains unknown. Here, we investigated nitrogen fixation rates in the particulate and dissolved fractions within the euphotic zone of the North Pacific Subtropical Gyre. Our findings reveal the proportion of nitrogen fixation rates in the dissolved fraction increases with depth. Light manipulation experiments uncover that reduced light levels can stimulate the net release of diazotroph-derived nitrogen, aligning with our depth-related observations. Furthermore, we identify two distinct transfer pathways vertically associated with light-driven ecological niches. Specifically, the released diazotroph-derived nitrogen is transferred to non-diazotrophic plankton in the upper layers. Meanwhile, in the lower layers, it contributes to the nitrification process. Our results underscore the high bioavailability of diazotroph-derived nitrogen and its rapid integration into the nitrogen cycle through multiple pathways within the well-lit ocean. New study finds diazotroph-derived nitrogen is utilized by phytoplankton in upper euphotic zone, while below, it is used by nitrifiers. The newly identified pathways reveal the marine nitrogen cycle may be more interconnected than previously recognized. [ABSTRACT FROM AUTHOR]

Background: Genetic variations have emerged as crucial players in the etiology of Alzheimer's disease (AD), and they serve for a better understanding of the disease mechanisms; yet the specific roles of these genetic variants remain uncertain. Animal models with reminiscent disease pathology could uncover previously uncharacterized roles of these genes. Therefore, we generated zebrafish models for AD variants to analyze the in depth molecular and biological functions of these variants. Method: Using CRISPR/Cas9, we generated a knockout model for abca7, orthologous to human ABCA7. We performed single cell transcriptomics and analyzed the altered genes and molecular pathways in zebrafish. We leveraged data from multiethnic AD cohorts at Mayo Clinic and Columbia University, to perform genetic association studies, co‐expression analyses, in silico interaction mapping, family based variant segregation analyses and epigenetic association studies, and the functional and histological studies in zebrafish. Result: The abca7± zebrafish reduced astroglial proliferation, synaptic integrity, and microglial response after Aβ42 toxicity. We found that the abca7 loss‐of‐function (LOF) reduced neuropeptide Y (npy) expression as well as Brain‐derived neurotrophic factor (bdnf) and Nerve growth factor receptor (ngfr). Human brain analysis showed reduced NPY in AD, regulatory interaction between NPY and BDNF, genetic variants in NPY associated with AD, and segregation of variants in ABCA7, BDNF and NGFR in families. ABCA7 variants altered the epigenetic codes in NPY, BDNF, and NGFR promoter regions. Human results paralleled with zebrafish findings to indicate an evolutionarily conserved disease mechanism through ABCA7‐NPY signalling axis. NPY administration to zebrafish rescued the phenotypes in abca7 knockout, suggesting a true biological relevance. Conclusion: Our results demonstrate a previously unknown link between ABCA7 and NPY in regulation of synaptic integrity and neurogenesis in AD. We propose that ABCA7‐dependent NPY is a resilience factor in vertebrate brains, and this reserve mechanism is impaired in AD. [ABSTRACT FROM AUTHOR]

The heavily human-perturbed coastal oceans are hotspots of nitrous oxide (N2O) emission to the atmosphere. The processes underpinning the N2O flux, however, remain poorly understood, leading to large uncertainties in assessing global N2O budgets. Using a suite of nitrogen isotope labeling experiments, we show that multiple processes contribute to N2O production throughout the estuarine-coastal gradient, sustaining intensive N2O flux to the atmosphere. Unexpectedly, denitrification, rather than ammonia oxidation as previously assumed, constitutes the major source of N2O in well-oxygenated coastal waters. Size-fractionated manipulation experiments with gene analysis further reveal niche partitioning of ammonia oxidizers and denitrifiers across the particle size spectrum; denitrification dominated on large particles and ammonia oxidizers on small particles. Total N2O production rate increases with substrate and particle concentrations, suggesting a crucial interplay between nutrients and particles in controlling N2O production. The controlling factors identified here may help understand climate feedback mechanisms between human activity and coastal oceans.Incomplete denitrification associated with the micro-niche of marine particles, instead of nitrification as previously assumed, is a major source of N2O in the turbid coastal waters, even though the water is well-oxygenated. [ABSTRACT FROM AUTHOR]

To evaluate the association between cesarean scar nice (CSN) and pelvic pain. We performed a systematic review and meta-analysis. A comprehensive strategy was used to search MEDLINE, PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, and clinicaltrials.gov. PROSPERO registration was obtained (CRD42022346443). We included published manuscripts of randomized controlled trials, prospective and retrospective cohorts, and case series. Inclusion criteria was limited to studies including symptomatic patients with a radiologic diagnosis of a CSN, and those which evaluated pain as an outcome. Risk of bias was assessed with the Robins-I tool. The primary outcome was prevalence of pelvic pain in patients with confirmed CSN. Other outcomes included the risk of pain in patients with CSN compared those without, and changes in pain symptoms following medical or surgical management of niche. Forty-seven studies reported on pain (dysmenorrhea, dyspareunia, chronic pelvic pain (CPP), suprapubic pain (SPP)) in patients with CSN. Patients with a CSN were at increased risk of dysmenorrhea (RR 2.25, 95%CI 0.90-5.62), dyspareunia (RR 2.05 95%CI 1.42-2.99), and CPP (2.72, 95%CI 1.63-4.54) compared to those without. In symptomatic patients with a confirmed niche, the prevalence of dysmenorrhea was 35.4% (95%CI 31.0-56.5); dyspareunia 20.1% (95%CI 14.3-48.7); CPP 20.2% (95%CI 15.9-36.2) and SPP 33.5% (95%CI 14.4-58.0). Both medical and surgical treatment of CSN were associated with a significant decrease in pain (OR 0.11, 95%CI 0.06-0.22, 17 studies, 999 patients, I2=83.0%). Most studies were high risk for measurement bias due to lack of standardization for outcome measures. There is a strong association between uterine niche and various pelvic pain symptoms. Providers should have a low threshold to assess for CSN in patients with a history of otherwise unexplained pain arising after cesarean delivery, and treatment should be strongly considered. Future studies require standardization of nomenclature and reporting for pain in this context. [ABSTRACT FROM AUTHOR]

This article, published in the journal "Ultrasound in Obstetrics & Gynecology," discusses the use of transvaginal sonographic (TVS) sliding bladder sign as a diagnostic tool for predicting vesicouterine adhesions. The study conducted at Amsterdam UMC included patients scheduled for gynecologic laparoscopic surgery for a benign disorder. The results showed that the absence of sliding bladder on TVS had a high positive predictive value for any adhesions and a high sensitivity for severe adhesions. The presence of sliding bladder had a high negative predictive value for severe adhesions and a high specificity for any adhesions. The study concludes that the sliding bladder sign using TVS is a reliable tool for predicting vesicouterine adhesions and recommends its routine use in preoperative planning. [Extracted from the article]