Seasonal Variation in Birth Rates: Physiology versus Family Planning.

Seasonal variation in birth rates is a ubiquitous property of human populations. Although the general birth rate is dependent on relatively few parameters-sexual behavior, zygote survival, and the number of ova released-the quantitative influence of the effects of each is difficult to estimate. Research has been directed more towards seasonal variation in physiology and less towards behavioral effects such as preferences for birthing in particular seasons. This may be because alongside seasonal variation in birth rate there is also seasonal variation in the multiple birth rate, which necessarily depends on the same physiological factors as the birth rate, suggestive of a link. Here we use a simulation that follows females through their reproductive lives, replicating the incidence of singleton and twin births that arise from single and double ovulations. We use the simulation to quantify the impact of seasonal variation in the physiological variables that affect birth rate. We can generate the seasonal variation in twinning rates observed in European populations, but this does not generate the magnitude of the observed seasonal variation in birth rate. Our simulation shows that, despite correlations between twinning rate and general birth rate, seasonal changes in sexual behavior are necessary to explain the magnitude of the seasonal variation in the general birth rate in humans.

Mesenchymal stem cell-derived small extracellular vesicles alleviate the immunometabolic dysfunction in murine septic encephalopathy.

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection that results in high mortality and long-term sequela. The central nervous system (CNS) is susceptible to injury from infectious processes, which can lead to clinical symptoms of septic encephalopathy (SE). SE is linked to a profound energetic deficit associated with immune dysregulation. Here, we show that intravenous administration of adipose tissue mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) in septic mice improved disease outcomes by reducing SE clinical severity, restoring aerobic metabolism, and lowering pro-inflammatory cytokines in the cerebellum, a key region affected by SE. Our high throughput analysis showed that MSC-derived sEVs partially reversed sepsis-induced transcriptomic changes, highlighting the potential association of miRNA regulators in the cerebellum of MSC-derived sEV-treated mice with miRNAs identified in sEV cargo. MSC-derived sEVs could serve as a promising therapeutic agent in SE through their favorable immunometabolic properties.

Differences in testing for drugs of abuse amongst racial and ethnic groups at children's hospitals.

OBJECTIVES: Racial and ethnic differences in drug testing have been described among adults and newborns. Less is known regarding testing patterns among children and adolescents. We sought to describe the association between race and ethnicity and drug testing at US children's hospitals. We hypothesized that non-Hispanic White children undergo drug testing less often than children from other groups. METHODS: We conducted a retrospective cohort study of emergency department (ED)-only encounters and hospitalizations for children diagnosed with a condition for which drug testing may be indicated (abuse or neglect, burns, malnutrition, head injury, vomiting, altered mental status or syncope, psychiatric, self-harm, and seizure) at 41 children's hospitals participating in the Pediatric Health Information System during 2018 and 2021. We compared drug testing rates among (non-Hispanic) Asian, (non-Hispanic) Black, Hispanic, and (non-Hispanic) White children overall, by condition and patient cohort (ED-only vs. hospitalized) and across hospitals. RESULTS: Among 920,755 encounters, 13.6% underwent drug testing. Black children were tested at significantly higher rates overall (adjusted odds ratio [aOR]: 1.18; 1.05-1.33) than White children. Black-White testing differences were observed in the hospitalized cohort (aOR: 1.42; 1.18-1.69) but not among ED-only encounters (aOR: 1.07; 0.92-1.26). Asian, Hispanic, and White children underwent testing at similar rates. Testing varied by diagnosis and across hospitals. CONCLUSIONS: Hospitalized Black children were more likely than White children to undergo drug testing at US children's hospitals, though this varied by diagnosis and hospital. Our results support efforts to better understand and address healthcare disparities, including the contributions of implicit bias and structural racism.

Child Health Needs and the Pediatric Hospital Medicine Workforce: 2020-2040.

Pediatric hospital medicine (PHM) established a new model of care for hospitalized children in the United States nearly 3 decades ago. In that time, the field experienced rapid growth while distinguishing itself through contributions to medical education, quality improvement, clinical and health services research, patient safety, and health system leadership. Hospital systems have also invested in using in-house pediatricians to manage various inpatient care settings as patient acuity has accelerated. National PHM leaders advocated for board certification in 2014, and the first certification examination was administered by the American Board of Pediatrics in 2019. In this article, we describe the development of the subspecialty, including evolving definitions and responsibilities of pediatric hospitalists. Although PHM was not included in the model forecasting future pediatric subspecialties through 2040 in this supplement because of limited historical data, in this article, we consider the current and future states of the workforce in relation to children's health needs. Expected challenges include potential alterations to residency curriculum, changes in the number of fellowship positions, expanding professional roles, concerns related to job sustainability and burnout, and closures of pediatric inpatient units in community hospitals. We simultaneously forecast growing demand in the PHM workforce arising from the increasing prevalence of children with medical complexity and increasing comanagement of hospitalized children between pediatric hospitalists and other subspecialists. As such, our forecast incorporates a degree of uncertainty and points to the need for ongoing investments in future research to monitor and evaluate the size, scope, and needs of pediatric hospitalists and the PHM workforce.

Serologic Screening for Genital Herpes: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

This systematic review to support the 2023 US Preventive Services Task Force Recommendation Statement on serologic screening for genital herpes summarizes published evidence on the benefits and harms of screening and interventions for genital herpes in asymptomatic sexually active adolescents, adults, and pregnant persons with no clinical history of genital herpes.

The Association Between Routine Car Seat Screening and Subsequent Health Care Utilization.

BACKGROUND AND OBJECTIVES: The American Academy of Pediatrics recommends preterm newborns undergo car seat tolerance screening (CSTS) before discharge despite limited evidence supporting the practice. We examined subsequent health care utilization in screened and unscreened late preterm and low birth weight newborns. METHODS: This observational study included late preterm (34-36 weeks) and term low birth weight (<2268 g) newborns born between 2014 and 2018 at 4 hospitals with policies recommending CSTS for these infants. Birth hospitalization length of stay (LOS) in addition to 30-day hospital revisits and brief resolving unexplained events were examined. Unadjusted and adjusted rates were compared among 3 groups: not screened, pass, and fail. RESULTS: Of 5222 newborns, 3163 (61%) were discharged from the nursery and 2059 (39%) from the NICU or floor. Screening adherence was 91%, and 379 of 4728 (8%) screened newborns failed the initial screen. Compared with unscreened newborns, adjusted LOS was similar for newborns who passed the CSTS (+5.1 hours; -2.2-12.3) but significantly longer for those who failed (+16.1; 5.6-26.7). This differed by screening location: nursery = +12.6 (9.1-16.2) versus NICU/floor = +71.2 (28.3-114.1) hours. Hospital revisits did not significantly differ by group: not screened = 7.3% (reference), pass = 5.2% (aOR 0.79; 0.44-1.42), fail = 4.4% (aOR 0.65; 0.28-1.51). CONCLUSIONS: Hospital adherence to CSTS recommendations was high, and failed screens were relatively common. Routine CSTS was not associated with reduced health care utilization and may prolong hospital LOS, particularly in the NICU/floor. Prospective trials are needed to evaluate this routine practice for otherwise low-risk infants.

Characteristics and Outcomes of Children Discharged With Nasoenteral Feeding Tubes.

OBJECTIVES: To describe the characteristics and outcomes of children discharged from the hospital with new nasoenteral tube (NET) use after acute hospitalization. METHODS: Retrospective cohort study using multistate Medicaid data of children <18 years old with a claim for tube feeding supplies within 30 days after discharge from a nonbirth hospitalization between 2016 and 2019. Children with a gastrostomy tube (GT) or requiring home NET use in the 90 days before admission were excluded. Outcomes included patient characteristics and associated diagnoses, 30-day emergency department (ED-only) return visits and readmissions, and subsequent GT placement. RESULTS: We identified 1815 index hospitalizations; 77.8% were patients ≤5 years of age and 81.7% had a complex chronic condition. The most common primary diagnoses associated with index hospitalization were failure to thrive (11%), malnutrition (6.8%), and acute bronchiolitis (5.9%). Thirty-day revisits were common (49%), with 26.4% experiencing an ED-only return and 30.9% hospital readmission. Revisits with a primary diagnosis code for tube displacement/dysfunction (10.7%) or pneumonia/pneumonitis (0.3%) occurred less frequently. A minority (16.9%) of patients progressed to GT placement within 6 months, 22.3% by 1 year. CONCLUSIONS: Children with a variety of acute and chronic conditions are discharged from the hospital with NET feeding. All-cause 30-day revisits are common, though revisits coded for specific tube-related complications occurred less frequently. A majority of patients do not progress to GT within a year. Home NET feeding may be useful for facilitating discharge among patients unable to meet their oral nutrition goals but should be weighed against the high revisit rate.

Dual-Energy CT to Diagnose Occult Femoral Neck Fracture in MRI-Contraindicated Patient: A Case Report.

CASE: A 79-year-old woman presented after a ground level fall with the inability to bear weight on her right hip. Radiographs and computed tomography (CT) imaging were negative for a femoral neck fracture. Her medical comorbidities precluded magnetic resonance imaging (MRI), so dual-energy CT with focused evaluation for bone edema was performed, identifying a femoral neck fracture that was stabilized surgically. CONCLUSION: Dual-energy CT with processing for edema can successfully identify nondisplaced femoral neck fractures in MRI-contraindicated patients. This imaging modality could be useful for diagnosing femoral neck stress fractures and ipsilateral femoral neck fractures in patients sustaining high-energy femoral shaft fractures.

Trends in Hospital Costs and Levels of Services Provided for Children With Bronchiolitis Treated in Children's Hospitals.

Importance: Increasing hospital costs for bronchiolitis have been associated with increasing patient complexity and mechanical ventilation. However, the associations of illness severity and diagnostic coding practices with bronchiolitis hospitalization costs have not been examined. Objective: To investigate the association of patient complexity, illness severity, and diagnostic coding practices with bronchiolitis hospitalization costs. Design, Setting, and Participants: This retrospective cross-sectional study included 385 883 infants aged 24 months or younger who were hospitalized with bronchiolitis at 39 hospitals in the Pediatric Health Information System database from January 1, 2010, to December 31, 2019. Exposure: Hospitalization for bronchiolitis. Main Outcomes and Measures: Inflation-adjusted standardized unit cost (expressed in dollar units) per hospitalization over time. A nested subgroup analysis was performed to further examine factors associated with changes in cost. Results: A total of 385 883 bronchiolitis hospitalizations were studied; the patients had a mean (SD) age of 7.5 (6.4) months and included 227 309 of 385 883 boys (58.9%) and 253 870 of 385 883 publicly insured patients (65.8%). Among patients hospitalized with bronchiolitis, the median standardized unit cost per hospitalization increased significantly during the study period (from $5636 [95% CI, $5558-$5714] in 2010 to $6973 [95% CI, $6915-$7030] in 2019; P < .001 for trend). Similar increases in cost were observed among subgroups of patients without a complex chronic condition and without the need for mechanical ventilation. However, costs for patients without a complex chronic condition or mechanical ventilation, who received care outside the intensive care unit did not change in an economically significant manner (from $4803 [95% CI, $4752-$4853] in 2010 to $4853 [95% CI, $4811-$4895] in 2019; P < .001 for trend), suggesting that intensive care unit use was a primary factor associated with cost increases. Substantial changes in coding practices were observed. Among patients hospitalized with bronchiolitis, 1.2% (95% CI, 1.1%-1.3%) were assigned an APR-DRG (All Patient Refined Diagnosis Related Group) for respiratory failure in 2010, which increased to 21.6% (95% CI, 21.2%-21.9%) in 2019 (P < .001 for trend). Increased costs and coding intensity were not accompanied by objective evidence of worsening illness severity. Conclusions and Relevance: This cross-sectional study suggests that hospitalized children with bronchiolitis are receiving costlier and more intensive care without objective evidence of increasing severity of illness. Changes in coding practices may complicate efforts to study trends in the use of health care resources using administrative data.

Effect of sample type and the use of high or low fishmeal diets on bacterial communities in the gastrointestinal tract of Penaeus monodon.

In shrimp aquaculture, manufactured diets that include various supplements and alternative fishmeal ingredients are increasingly being used and their effect on the gastrointestinal (GI) microbiota studied. However, dietary effects on different shrimp GI samples are not known. We investigated how a high (HFM) or low (LFM) fishmeal diet affects bacterial communities from different sample types collected from Penaeus monodon gastrointestinal tract. Bacterial communities of the stomach, intestine tissue and intestine digesta were assessed using 16s rRNA gene sequencing. The feed pellets were also assessed as a potential source of bacteria in the GI tract. Results showed substantial differences in bacterial communities between the two diets as well as between the different sample types. Within the shrimp GI samples, stomach and digesta communities were most impacted by diet, while the community observed in the intestine tissue was less affected. Proteobacteria, Firmicutes and Bacteroidetes were the main phyla observed in shrimp samples, with enrichment of Bacteroidetes and Firmicutes in the LFM fed shrimp. The feed pellets were dominated by Firmicutes and were largely dissimilar to the shrimp samples. Several key taxa were shared however between the feed pellets and shrimp GI samples, particularly in the LFM fed shrimp, indicating the pellets may be a significant source of bacteria observed in shrimp GI samples. In summary, both diet and sample type influenced the bacterial communities characterised from the shrimp GI tract. Thus, it is important to consider the sample type collected from the GI tract when investigating dietary impacts on gut bacterial communities in shrimp. KEY POINTS: • Shrimp gastrointestinal communities are influenced by diet and sample type. • The low fishmeal diet enriched bacteria that aid in polysaccharide metabolism. • Feed pellets can be a source of bacteria-detected gastrointestinal tract of shrimp.

Knowledge and Attitudes Towards Fluid Hydration of Athletes by Jamaican Track and Field High-school Coaches

ABSTRACT Objective: To determine whether or not Jamaican coaches' knowledge and practices of fluid replacement are on par with that of the National Athletic Association's and the American College of Sports Medicine Standards. Methods: A descriptive survey of 90 high-school track and field coaches in Jamaica was conducted. Coaches were given a 29-item survey questionnaire which adapted the content from previous surveys and also based on the National Athletic Trainers' Association guidelines for fluid replacement and information sources of fluid replacement. A pass score of 80% was employed. Results: Approximately 26.6% of participants passed the knowledge-based assessment with the minimum requirement of 80% and 73.4% of participants had an unacceptable level of knowledge about fluid replacement and hydration. Only 26 (28.9%) coaches received training in fluid replacement therapy. Most of them therefore relied on reading materials ranging from magazines to journals, or learnt it on the job from other coaches. Conclusion: Findings suggest that the level of knowledge in Jamaican track and field high-school coaches about fluid replacement and hydration is very poor. However, their attitudes towards fluid replacement and hydration are very good, and this will facilitate their acceptance and adoption of correct fluid replacement guidelines. Tapping into this positive attitude and implementing workshops, seminars and onsite promotion should improve the coaches' knowledge significantly.

An age-dependent ovulatory strategy explains the evolution of dizygotic twinning in humans.

Dizygotic twinning, the simultaneous birth of siblings when multiple ova are released, is an evolutionary paradox. Twin-bearing mothers often have elevated fitness, but despite twinning being heritable, twin births occur only at low frequencies in human populations. We resolve this paradox by showing that twinning and non-twinning are not competing strategies; instead, dizygotic twinning is the outcome of an adaptive conditional ovulatory strategy of switching from single to double ovulation with increasing age. This conditional strategy, when coupled with the well-known decline in fertility as women age, maximizes reproductive success and explains the increase and subsequent decrease in the twinning rate with maternal age that is observed across human populations. We show that the most successful ovulatory strategy would be to always double ovulate as an insurance against early fetal loss, but to never bear twins. This finding supports the hypothesis that twinning is a by-product of selection for double ovulation rather than selection for twinning.

Dietary starch promotes hepatic lipogenesis in barramundi (Lates calcarifer).

Barramundi (Lates calcarifer) are a highly valued aquaculture species, and, as obligate carnivores, they have a demonstrated preference for dietary protein over lipid or starch to fuel energetic growth demands. In order to investigate how carnivorous fish regulate nutritional cues, we examined the metabolic effects of feeding two isoenergetic diets that contained different proportions of digestible protein or starch energy. Fish fed a high proportion of dietary starch energy had a higher proportion of liver SFA, but showed no change in plasma glucose levels, and few changes in the expression of genes regulating key hepatic metabolic pathways. Decreased activation of the mammalian target of rapamycin growth signalling cascade was consistent with decreased growth performance values. The fractional synthetic rate (lipogenesis), measured by TAG 2H-enrichment using 2H NMR, was significantly higher in barramundi fed with the starch diet compared with the protein diet (0·6 (se 0·1) v. 0·4 (se 0·1) % per d, respectively). Hepatic TAG-bound glycerol synthetic rates were much higher than other closely related fish such as sea bass, but were not significantly different (starch, 2·8 (se 0·3) v. protein, 3·4 (se 0·3) % per d), highlighting the role of glycerol as a metabolic intermediary and high TAG-FA cycling in barramundi. Overall, dietary starch significantly increased hepatic TAG through increased lipogenesis. Compared with other fish, barramundi possess a unique mechanism to metabolise dietary carbohydrates and this knowledge may define ways to improve performance of advanced formulated feeds.

Effect of asthma and six-months high-intensity interval training on heart rate variability during exercise in adolescents.

Little is known regarding the influence of asthma and exercise, and their interaction, on heart rate variability (HRV) in adolescents. Thirty-one adolescents with asthma (13.7±0.9 years; 21.9±3.9 kg·m-2; 19 boys, 12 girls) and thirty-three healthy adolescents (13.8±0.9 years; 20.3±3.2 kg·m-2; 16 boys, 17 girls) completed an incremental ramp test and three heavy-intensity constant-work-rate cycle tests. Thirteen adolescents (7 boys, 6 girls; 6 asthma, 7 control) completed six-months high-intensity interval training (HIIT) and were compared to age- and sex-matched controls. Standard time-domain, frequency-domain and non-linear indices of HRV were derived at baseline, three- and six-months. Asthma did not influence HRV at baseline or following HIIT. Total power, low frequency and normalised low frequency power, and sympathovagal balance increased at three-months in HIIT, subsequently declining towards baseline at six-months. Normalised high frequency power was reduced at three-months in both groups, which was sustained at six-months. No effects of HIIT were observed in the time-domain nor in the non-linear indices. HRV was not influenced by asthma, potentially because such derangements are a function of disease progression, severity or duration. HIIT may be associated with a short-term shift towards greater sympathetic predominance during exercise, perhaps caused by physiological overload and fatigue.

Attitudes of Residents and Program Directors Towards Research in Otolaryngology Residency.

OBJECTIVE:: To determine attitudes of residents and program directors towards research during residency training. STUDY DESIGN:: Survey of current otolaryngology residents and program directors. SETTING:: Otolaryngology residency programs. METHODS:: An anonymous web-based survey ( www.surveymonkey.com ) was sent to 106 program directors (PDs) and 115 program coordinators. The program coordinators subsequently sent it to residents. Fisher exact tests and correlations were used to determine statistically significant differences. RESULTS:: Overall, 178 residents and 31 PDs responded to our surveys. All residents surveyed reported some research experience prior to residency. Residents who reported a previous first-author manuscript publication prior to residency were more likely than residents who had no previous first-author publication to report a first-author publication during residency (58.44% vs 27.27%, P < .0001); 33% of the residents reported academics as a desired future career setting after residency. The most significant barrier to research perceived by the residents was time constraint due to residency duties and personal commitments (93% and 74%, respectively). The second and third most common barriers to research were lack of statistical knowledge at 52% and lack of interest in research at 43.6%. CONCLUSIONS:: Research is a required component of otolaryngology residency training. The most significant barrier in our survey was the lack of protected research time, followed by lack of biostatistical knowledge and interest. Program directors may need to implement structured research rotations tailored to individual residents' research interests and integrate training in research methodology and biostatistics.