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2.
Obstet Gynecol ; 141(1): 126-133, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36701613

RESUMO

OBJECTIVE: To evaluate the effect of fasting compared with eating before the 1-hour oral glucose tolerance test (OGTT) on gestational diabetes mellitus (GDM) screening results. METHODS: In a single-center, prospective randomized trial, participants were randomized to: 1) fasting for 6 or more hours or 2) oral intake ("fed") within 2 hours of the 50-g, 1-hour OGTT. The 1-hour OGTT was administered after 24 weeks of gestation. A positive screen result was defined as a serum glucose level of 140 mg/dL or higher. Protocol adherence was assessed by a survey administered immediately after the OGTT. We planned to enroll 100 participants in each group to detect an absolute difference of 20 percentage points or more on the 1-hour OGTT screen-positive rate using Fisher exact test, assuming an estimated screen-positive rate of 45% in the fasting and 25% in the fed group and 10% attrition, with a two-sided α=0.05, power=0.8. The primary outcome was the 1-hour OGTT screen-positive rate. Secondary outcomes included mean 1-hour OGTT glucose values, GDM diagnosis, maternal and neonatal outcomes, and patient perceptions regarding the 1-hour OGTT. RESULTS: From November 2020 through April 2021, 200 participants were randomized. One hundred ninety-five completed the 1-hour OGTT (97 fasting, 98 fed). Participant surveys confirmed 97.9% (n=95) adherence to the fasting and 91.8% (n=90) adherence to the fed groups. The screen-positive rate was significantly higher in the fasting than the fed group (32.0% vs 13.3%, respectively, P=.002), as was the mean glucose value (127.7 mg/dL vs 113.3 mg/dL, P=.002). The incidence of GDM in the fasting group was 12.4% (n=12) and in the fed group was 5.1% (n=5) (P=.08). There were no significant differences in maternal or neonatal outcomes. CONCLUSION: Fasting for 6 or more hours doubled the incidence of a positive 1-hour OGTT result when compared with eating within 2 hours of the test. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT04547023.


Assuntos
Glicemia , Diabetes Gestacional , Gravidez , Feminino , Recém-Nascido , Humanos , Teste de Tolerância a Glucose , Estudos Prospectivos , Diabetes Gestacional/epidemiologia , Glucose , Jejum
3.
J Obstet Gynaecol Res ; 48(6): 1466-1474, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35272394

RESUMO

AIM: The purpose of this study is to investigate what factors make students feel confident and competent when performing a female genitourinary exam (FGUE) with normal, nonpathologic findings. We anticipated that students would increase their confidence and perceived competence from the first year to the second year of medical school, would prefer the use of specialized standardized patients (SSPs) over models, and that the results would vary by student demographics. METHODS: Student confidence and perceived competence were measured using voluntary survey methods pre- and postinterventions. Interventions were defined as learning the FGUE on models alone for first-year medical students and learning the FGUE on SSPs with prior experience using models for second-year students. Survey responses were evaluated via generalized linear mixed models for numeric responses. RESULTS: The results demonstrated that first- and second-year medical students of racial and ethnic minorities rated themselves as more confident and competent than Caucasian counterparts, which was in many cases more extensive than the effect of an additional year of medical education. Students felt that using SSPs alone was the best mode of learning the exam than either models alone or the combination of models and SSPs. Students' current specialty of choice did not correlate with increased confidence or perceived competence. CONCLUSION: This study highlights how cultural differences have an impact on confidence and perceived competence in medical students as they prepare for performing a procedure as intimate to the patient as the FGUE.


Assuntos
Educação Médica , Estudantes de Medicina , Competência Clínica , Feminino , Humanos
4.
Front Psychol ; 12: 744842, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34526945

RESUMO

While research on metacognitive knowledge and metacognitive strategies in second language (L2) writing has proliferated, little attention has been paid to metacognitive experiences in learning to write. This study contributes a novel 6-point Likert scale questionnaire, EFL Learners' Writing Metacognitive Experiences Questionnaire (EFLLWMEQ), and reports insights into learners' metacognitive experiences gathered from its use. The questionnaire was designed to investigate, first, the nature of students' metacognitive experiences when they learn to write in English as a foreign language (EFL) and, secondly, the relationship between students' metacognitive experiences and their writing performance. To this end, the questionnaire was developed and validated with two independent samples of 340 and 540 Chinese undergraduates whose metacognitive experiences were measured as they learned to write in EFL. Data were subjected to exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), respectively. Findings of EFA and CFA revealed a four-factor structure of students' metacognitive experiences of EFL writing: Metacognitive estimates, metacognitive feelings, online task-specific metacognitive knowledge, and online task-specific metacognitive strategies. Results showed that students' metacognitive experiences had positive correlations with their EFL writing test scores. Importantly, the CFA results from the sample of 540 students supported the four-factor correlated model with the best model fit, confirming the validity and reliability of the EFLLWMEQ. This study has theoretical and pedagogical implications for how learners' metacognitive experiences can be managed in learning to write, particularly in EFL classrooms.

5.
Am J Disaster Med ; 15(4): 241-249, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33428195

RESUMO

OBJECTIVE: As the incidence of active shooters increase, local emergency response has also changed. South Metro Fire Rescue coordinated a series of hyper-realistic active shooter simulation drills involving multiple agencies. METHODS: "The Next Nine Minutes" was one of the largest active shooter drills performed to date with 904 personnel that were trained in 18 mass casualty active shooter drills. Evaluation was from point of injury to and including care in the operating room (OR), and evaluation of real-time system logistics. RESULTS: A total of 126 patients in Cut Suits® received a total of 479 procedures such as needle decompressions, cricothyrotomies, tourniquets, wound packs, and chest tubes. Central to this exercise, law enforcement (LE) established a warm zone from the initial shooting. EMS was able to move into the facility, locate casualties, extract the first victim, move them to a casualty collection point (CCP), and transport them to safety within 12 minutes. CONCLUSIONS: Strengths and weaknesses were identified in prehospital and in-hospital care. These included what roles agencies play in a true event, specific timing in establishing areas such as the warm zone and CCP, transportation, and logistics at the accepting hospitals. Only after the barriers to success were identified and addressed did the timing of casualty movement drastically improve. Lessons learned from this training were ultimately used to save lives at the STEM School, Highlands Ranch, and Colorado Shooting. This in situ immersion training should be practiced as a whole system.


Assuntos
Planejamento em Desastres , Serviços Médicos de Emergência , Incidentes com Feridos em Massa , Serviço Hospitalar de Emergência , Humanos , Instituições Acadêmicas , Torniquetes
6.
J Altern Complement Med ; 25(S1): S86-S94, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30870025

RESUMO

BACKGROUND: Integrative health is an expanding field that is increasingly called upon by conventional medicine to provide care for patients with chronic pain and disease. Although evidence has mounted for delivering integrative therapies individually, there is little consensus on how best to deliver these therapies in tandem as part of whole person care. While many models exist, few are financially sustainable. METHODS AND RESULTS: This article describes a conceptual and logistical model for providing integrative outpatient health care within an academic medical center or hospital system to patients with chronic pain and disease. In hopes that the model will be replicated, administrative details are provided to explain how the model operates and has been maintained over nine years. The details include the intentional building of a particular work culture. CONCLUSION: This whole person care model that addresses chronic pain and disease in an outpatient integrative clinic has been successful, sustainable and can be replicated in other academic medical centers or hospital clinics.


Assuntos
Dor Crônica/terapia , Saúde Holística , Modelos Organizacionais , Assistência Centrada no Paciente , Humanos , Medicina Integrativa
7.
Int J Sport Nutr Exerc Metab ; 28(4): 332-334, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29485333

RESUMO

Barbara Drinkwater has been a lifelong champion of equality for women in many areas of life well before it was widely accepted. Her "walking the walk" of women breaking barriers in traditional male roles in administration and leadership is exemplified by her election as the first woman president of the American College of Sports Medicine in 1988. Some of the controversial areas in which Barbara was vocal in the arena of women in sport, besides triad/relative energy deficiency in sport, include increased opportunity and participation, total equality, acceptance of diversity, intolerance of harassment and abuse, and fairness with transgender athletes. She co-founded the evidence-based advocacy group on the international stage known as Women Sport International. As a physiologist, Barbara has had a major influence on attention to the health of the female athlete, and she produced the original pioneering work in the field. Her impactful study, "Bone mineral density after resumption of menses in amenorrheic athletes," was published in the Journal of the American Medical Association in 1986. Since that time, the female athlete triad has set the stage for research and treatment to enhance women in physical activity at all levels.


Assuntos
Síndrome da Tríade da Mulher Atleta/fisiopatologia , Desnutrição/fisiopatologia , Fenômenos Fisiológicos da Nutrição Esportiva , Amenorreia/fisiopatologia , Anorexia/fisiopatologia , Atletas , Imagem Corporal , Metabolismo Energético , Feminino , Síndrome da Tríade da Mulher Atleta/diagnóstico , Síndrome da Tríade da Mulher Atleta/prevenção & controle , Humanos , Necessidades Nutricionais , Osteoporose/fisiopatologia , Esportes
8.
Sex Transm Dis ; 44(6): 380-383, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28499291

RESUMO

BACKGROUND: North Carolina Administrative Code 10A Chapter 41A.0204 (a) states "local health departments shall provide diagnosis, testing, treatment, follow-up, and preventive services for syphilis, gonorrhea, chlamydia, … These services shall be provided upon request and at no charge to the patient." Although health departments/districts may bill governmental or nongovernmental insurance providers for sexually transmitted disease (STD) services, current billing practices are unknown. Because of its high STD morbidity, the eastern region of North Carolina was targeted. METHODS: Using a Qualtrics Survey developed to measure attitudes as well as knowledge and reimbursement practices, this descriptive study was performed with staff from 25 eastern North Carolina health departments/districts. Snowball sampling was used to allow for greater inclusion. Analysis of data was performed at the individual and agency level based on types of questions in the survey. RESULTS: For knowledge, 87% of the respondents reported being aware of the possibility of reimbursement from third-party payers/commercial insurance carriers for STD services. In regard to current billing of these services, 20 health departments/districts (80%) reported they were billing these payers. When asked about their attitude of seeking reimbursement from commercial insurance, 92% reported it was acceptable or very acceptable. But when asked if STD services should remain a free service at the health department, 55% supported and 45% did not. CONCLUSIONS: These data provide a knowledge base for assisting health departments/districts to move forward in improving STD services as well as maximizing reimbursement from third-party payers/commercial insurance carriers when possible.


Assuntos
Instituições de Assistência Ambulatorial/economia , Conhecimentos, Atitudes e Prática em Saúde , Reembolso de Seguro de Saúde/economia , Seguro Saúde/estatística & dados numéricos , Infecções Sexualmente Transmissíveis/economia , Infecções Sexualmente Transmissíveis/terapia , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Custos e Análise de Custo , Pesquisa sobre Serviços de Saúde , Humanos , Seguro Saúde/economia , North Carolina , Administração da Prática Médica
9.
Gynecol Endocrinol ; 33(4): 324-327, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27910718

RESUMO

OBJECTIVE: Hyperinsulinemia is a prevalent feature of polycystic ovary syndrome (PCOS), contributing to metabolic and reproductive manifestations of the syndrome. Weight loss reduces hyperinsulinemia but weight regain is the norm, thus preventing long-term benefits. In the absence of weight loss, replacement of dietary carbohydrate (CHO) with mono/polyunsaturated fat reduces ambient insulin concentrations in non-PCOS subjects. The current study evaluated whether this dietary intervention could ameliorate hyperinsulinemia in women with PCOS. DESIGN/SETTING/PATIENTS: Obese women with PCOS (BMI 39 ± 7 kg/m2) and insulin resistance completed a crossover study (Stanford University Clinical Research Center) comparing two isocaloric diets, prepared by research dietitians, containing 60% CHO/25% fat versus 40% CHO/45% fat (both 15% protein and ≤7% saturated fat). After 3 weeks on each diet, daylong glucose, insulin, and fasting lipid/lipoproteins were measured. RESULTS: Daylong glucose did not differ according to diet. Daylong insulin concentrations were substantially (30%) and significantly lower on the low CHO/higher fat diet. Beneficial changes in lipid profile were also observed. CONCLUSIONS: Replacement of dietary CHO with mono/polyunsaturated fat yields clinically important reductions in daylong insulin concentrations, without adversely affecting lipid profile in obese, insulin-resistant women with PCOS. This simple and safe dietary intervention may constitute an important treatment for PCOS. ClinicalTrials.gov Identifier: NCT00186459.


Assuntos
Carboidratos da Dieta/administração & dosagem , Gorduras Insaturadas na Dieta/administração & dosagem , Hiperinsulinismo/dietoterapia , Resistência à Insulina/fisiologia , Insulina/sangue , Síndrome do Ovário Policístico/dietoterapia , Adulto , Glicemia/metabolismo , Estudos Cross-Over , Feminino , Humanos , Hiperinsulinismo/sangue , Lipídeos/sangue , Obesidade/sangue , Síndrome do Ovário Policístico/sangue , Resultado do Tratamento , Adulto Jovem
10.
J Sports Sci Med ; 15(4): 592-600, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27928204

RESUMO

Cancer survivors (CA) tend to demonstrate metabolic, cardiac, and ventilatory alterations due to previous chemotherapy and radiation that may impair adaptability following aerobic exercise training. Exercise training adaptations of CA finished with primary treatment compared to non-cancer participants (NC) have not yet been extensively elucidated. Thus, the present study compared physiologic responses of CA versus NC following a low-to-moderate intensity, 8-wk aerobic training program. Thirty-seven previously sedentary participants (CA: n = 14, 12 females; NC: n = 23, 19 females) with no heart or metabolic disease did not differ in age, height, weight, and body mass index (51 ± 2 y, 1.66 ± 0.02 m, 83.8 ± 3.2 kg, and 30.5 ± 1 kg·m-2). Each participant underwent baseline, 3-, 6-, and 8-wk VO2peak treadmill testing using the USAFSAM protocol and walked on a treadmill three times per week at 80-90% of ventilatory threshold (VT) for approximately 40-min·session-1. Variables obtained on the VO2peak tests included: HR at stage 2 (HR@stage2), rating of perceived exertion at stage 2 (RPE@stage2), lactate threshold (LT), ventilatory threshold (VT), salivary cortisol at 30-min post VO2peak test (SC@30-minPost),VO2peak level, time of fatigue (TOF), and maximal heart rate (HRmax). NC had significantly (p < 0.05) higher VO2peak, TOF, and HRmax at baseline, 3- and 6-wks of training but not at 8-wks. There were no differences between groups on RPE@stage2 except at baseline (p < 0.05). A significant (p < 0.05) interaction was observed only for RPE@stage2 with CA rating their initial RPE significantly greater at baseline versus NC. CA notably improved submaximal and maximal exercise capacity during 8 weeks of aerobic training and did not show altered adaptability compared to NC. We suggest prescribing aerobic exercise training at low/moderate intensity and duration initially, with progressive increases in duration and intensity after approximately 8-weeks. If available and supported, we advise clinicians to utilize submaximal threshold concepts obtained from cardiopulmonary exercise testing to prescribe more precise aerobic exercise training parameters.

11.
Am J Perinatol ; 33(2): 172-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26344009

RESUMO

OBJECTIVE: To examine whether women with prediabetes benefit from early treatment for gestational diabetes mellitus (GDM). STUDY DESIGN: Women with a glycosylated hemoglobin A1C (A1C) of 5.7 to 6.4% at <14 weeks were recruited. Participants were randomized to usual care or treatment for GDM with diet, blood glucose monitoring, and insulin as needed. The primary outcome was a 75-g oral glucose tolerance test at 26 to 28 weeks. Secondary outcomes included cesarean delivery, birthweight, weight gain, and A1C change. RESULTS: Between May 2012 and June 2014, 95 women were enrolled and 83 had data for analysis; 42 were randomized to treatment and 41 to usual care. The groups were similar in baseline characteristics with 40% obese. There was no difference in the primary outcome (treatment 45.2% vs. control 56.1%; relative risk [RR] 0.80; 95% confidence interval [CI] 0.53-1.24) except that women in the treatment group had a significantly lower A1C over time than women in the control group (p = 0.04). Nonobese women (n = 50) treated for GDM experienced a 50% reduction in GDM compared with controls (29.6 vs. 60.9%; RR 0.49; 95% CI 0.25-0.95). CONCLUSION: Early treatment for women with a first-trimester A1C of 5.7 to 6.4% did not significantly reduce the risk of GDM except in nonobese women.


Assuntos
Peso ao Nascer , Diabetes Gestacional/prevenção & controle , Dieta para Diabéticos/métodos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Estado Pré-Diabético/terapia , Adulto , Cesárea/estatística & dados numéricos , Diabetes Gestacional/diagnóstico , Diabetes Gestacional/metabolismo , Diagnóstico Precoce , Intervenção Médica Precoce , Feminino , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/metabolismo , Humanos , Recém-Nascido , Obesidade/complicações , Estado Pré-Diabético/complicações , Estado Pré-Diabético/diagnóstico , Estado Pré-Diabético/metabolismo , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Diagnóstico Pré-Natal , Aumento de Peso
15.
Br J Sports Med ; 48(7): 491-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24620037

RESUMO

Protecting the health of the athlete is a goal of the International Olympic Committee (IOC). The IOC convened an expert panel to update the 2005 IOC Consensus Statement on the Female Athlete Triad. This Consensus Statement replaces the previous and provides guidelines to guide risk assessment, treatment and return-to-play decisions. The IOC expert working group introduces a broader, more comprehensive term for the condition previously known as 'Female Athlete Triad'. The term 'Relative Energy Deficiency in Sport' (RED-S), points to the complexity involved and the fact that male athletes are also affected. The syndrome of RED-S refers to impaired physiological function including, but not limited to, metabolic rate, menstrual function, bone health, immunity, protein synthesis, cardiovascular health caused by relative energy deficiency. The cause of this syndrome is energy deficiency relative to the balance between dietary energy intake and energy expenditure required for health and activities of daily living, growth and sporting activities. Psychological consequences can either precede RED-S or be the result of RED-S. The clinical phenomenon is not a 'triad' of the three entities of energy availability, menstrual function and bone health, but rather a syndrome that affects many aspects of physiological function, health and athletic performance. This Consensus Statement also recommends practical clinical models for the management of affected athletes. The 'Sport Risk Assessment and Return to Play Model' categorises the syndrome into three groups and translates these classifications into clinical recommendations.


Assuntos
Desempenho Atlético/fisiologia , Síndrome da Tríade da Mulher Atleta/prevenção & controle , Doenças Metabólicas/prevenção & controle , Conservadores da Densidade Óssea/uso terapêutico , Suplementos Nutricionais , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Feminino , Síndrome da Tríade da Mulher Atleta/metabolismo , Humanos , Masculino , Recuperação de Função Fisiológica , Medição de Risco , Medicina Esportiva
16.
Issues Compr Pediatr Nurs ; 35(3-4): 153-62, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23140411

RESUMO

Recent legislation enacted across the United States mandates schools to intervene and improve the reporting system of school bullying. Although the laws are an extension of safe school mandates, restoring justice in schools has taken a top priority. The lack of intensity of current anti-bullying programs and educators underestimating the gravity of bullying and its long-term effects on victims is problematic. In addition, little emphasis is being placed on understanding the research base of children who bully others. A review of the criminology and psychiatric research provides insight into the behavior of the bully. Studies demonstrate that bullying in school is a "gateway" behavior toward future criminal behavior; bullying will persist if professionals do not buy into the gravity of chronic child aggressors. Remediation directed at young children is essential, concurrent with the provision of teacher training programs focused on understanding the common behavioral disorders of childhood. A look at the existing research provides direction toward meeting the significant needs of children who bully others and perpetuate violence in schools and into adulthood.


Assuntos
Comportamento do Adolescente/psicologia , Bullying/psicologia , Vítimas de Crime/psicologia , Família/psicologia , Comunicação Interdisciplinar , Adolescente , Criança , Feminino , Humanos , Masculino , Grupo Associado , Serviços de Saúde Escolar/organização & administração , Instituições Acadêmicas , Inquéritos e Questionários , Estados Unidos
17.
Mol Genet Metab ; 107(3): 315-21, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23040521

RESUMO

OBJECTIVE: To compare the effects of combinatorial therapy with low-dose arginine and a nitrogen scavenging agent (sodium phenylbutyrate) vs. monotherapy with high-dose arginine on liver function tests in patients with argininosuccinic aciduria (ASA). STUDY DESIGN: Twelve patients with ASA were enrolled in a double-blind, placebo-controlled, cross-over study design. Subjects were randomized to receive either a low-dose of arginine therapy (100 mg · kg(-1) · d(-1)) combined with sodium phenylbutyrate (500 mg · kg(-1) · d(-1)) (LDA arm) or a high-dose of arginine alone (500 mg · kg(-1) · d(-1)) (HDA arm) for one week. At the end of one week of therapy, liver function tests were assessed and metabolite fluxes were measured using a multi-tracer stable isotope protocol. RESULTS: Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), and measures of synthetic functions of the liver were the primary outcomes. Subjects had significantly increased levels of argininosuccinate (P<0.03) and AST levels (P<0.01) after treatment with high-dose arginine. In the subset of subjects with elevated AST or ALT, treatment with high-dose of arginine was associated with further increases in plasma levels of both aminotransferases. Whereas subjects had increased arginine and citrulline flux with high-dose arginine therapy, the glutamine flux was not different between the two treatment arms. The synthetic liver functions as assessed by prothrombin time, INR, and coagulation factor levels were not different between the HDA and LDA arms. CONCLUSIONS: Administering higher doses of arginine in subjects with ASA results in increases in AST and ALT levels, especially in the subset of patients with elevated baseline aminotransferases. Hence, low-dose arginine sufficient to normalize arginine levels in plasma combined with nitrogen scavenging therapy should be considered as a therapeutic option for treatment of ASA in patients with elevations of hepatic aminotransferases.


Assuntos
Arginina/uso terapêutico , Acidúria Argininossuccínica/tratamento farmacológico , Fenilbutiratos/uso terapêutico , Adolescente , Alanina Transaminase/sangue , Arginina/sangue , Ácido Argininossuccínico/sangue , Acidúria Argininossuccínica/sangue , Aspartato Aminotransferases/sangue , Criança , Pré-Escolar , Estudos Cross-Over , Método Duplo-Cego , Esquema de Medicação , Quimioterapia Combinada , Feminino , Humanos , Testes de Função Hepática , Masculino , Fenilbutiratos/sangue , Placebos , Adulto Jovem
20.
Proc Natl Acad Sci U S A ; 109(7): 2269-74, 2012 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-22315397

RESUMO

The Mesozoic is marked by several widespread occurrences of intense organic matter burial. Sediments from the largest of these events, the Cenomanian-Turonian Oceanic Anoxic Event (OAE 2) are characterized by lower nitrogen isotope ratios than are seen in modern marine settings. It has remained a challenge to describe a nitrogen cycle that could achieve such isotopic depletion. Here we use nitrogen-isotope ratios of porphyrins to show that eukaryotes contributed the quantitative majority of export production throughout OAE 2, whereas cyanobacteria contributed on average approximately 20%. Such data require that any explanation for the OAE nitrogen cycle and its isotopic values be consistent with a eukaryote-dominated ecosystem. Our results agree with models that suggest the OAEs were high-productivity events, supported by vigorous upwelling. Upwelling of anoxic deep waters would have supplied reduced N species (i.e., NH(4)(+)) to primary producers. We propose that new production during OAE 2 primarily was driven by direct NH(4)(+)-assimilation supplemented by diazotrophy, whereas chemocline denitrification and anammox quantitatively consumed NO(3)(−) and NO(2)(−). A marine nitrogen reservoir dominated by NH(4)(+), in combination with known kinetic isotope effects, could lead to eukaryotic biomass depleted in (15)N.

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