Regular physical activity for adults is associated with optimal appetite regulation, though little work has been performed in adolescents. To address this gap in the literature, we conducted a study examining appetite across a range of physical activity and adiposity levels in adolescent males. Healthy males (n 46, 14–18 years old) were recruited across four body weight and activity categories: normal weight/high active (n 11), normal weight/low active (n 13), overweight, obese/high active (n 14), overweight and obese/low active (n 8). Participants from each group completed a 6-h appetite assessment session on Day 0, followed immediately by a 14-day free-living physical activity and dietary assessment period on Days 1–14, and a fitness test session occurring between Days 15–18. Subjective and objective assessment of appetite, resting energy expenditure, body composition using dual energy absorptiometry and thermic effect of feeding (TEF) was conducted on Day 0. Physiological variables in the normal weight low active group that were different than their peers included lower fat-free mass, cardiorespiratory fitness, glucose/fullness response to a standardised meal, TEF in response to a standardised meal, lower self-rated fullness and satiety and higher self-rated hunger to a standardised meal. Conversely, the overweight, obese high active group displayed better subjective appetite responses, but higher insulin responses to a standardised meal. Taken together, these results suggest that physical inactivity during adolescence has a negative impact on metabolic health and appetite control, which may contribute to future weight gain.

‘Sea salt is made by boiling and evaporating sea water over the fire. Bay salt, by evaporating sea water, in pits clayed on the inside, by the heat of the sun. Basket salt is made by boiling away the water of salt springs over the fire. Rock salt is dug out of the ground’, wrote Charlotte Mason in The Lady's Assistant (1775), one of the most comprehensive eighteenth-century cookbooks. Although there were at least four variations of salt before the pre-industrial era, several historical recipes specified the use of bay salt (solar salt) for meat preservation, elevating its cultural status and implying that early modern actors had a refined understanding of salts, their tastes and their applications. This study uses scientific analysis to determine whether there is a biological or chemical basis for the superior reputation of bay salt for curing. Laboratory data suggest that bay salt contains microbes that produce nitrate and nitrite, which give the meat a more favourable taste and pleasant aesthetic. The authors thus demonstrate that combining insights from experimental archaeology with textual analysis of historical sources gives us a deeper understanding of historical uses of taste as an epistemic tool.

Background: Transmission of carbapenemase-producing organisms (CPO) threatens patient safety in healthcare facilities. As a result of a 2011 outbreak of blaKPC+ Klebsiella pneumoniae, the NIH Clinical Center (NIHCC) has prioritized early detection and isolation of CPO carriers, using point-prevalence surveys and targeted high-risk ward surveillance since 2011 and admission surveillance since 2013. We describe our experience over 6 years of admission surveillance. Methods: The NIHCC is a 200-bed research hospital that provides care for a highly immunocompromised patient population. From September 2013 to September 2019, perirectal swabs were ordered automatically for all patients on admission to nonbehavioral health wards. Swabs were ordered twice weekly for ICU patients, weekly in other high-risk wards, and monthly for hospital-wide point prevalence (excluding behavioral health). Patients hospitalized in the United States in the previous week or abroad in the previous 6 months were considered high risk for carriage and isolated pending results from 2 swabs. Most swabs (n = 37,526) were cultured onto HardyCHROM CRE. If gram-negative bacilli (GNB) were present, a molecular screen for carbapenemases was performed on a sweep of cultured material (day 1) pending organism isolation. GNB were identified by MALDI-TOF MS. Prior to June 2019, isolates were screened by blaKPC/blaNDM PCR. Starting in June 2019, Enterobacteriaceae and Pseudomonas aeruginosa were screened using the phenotypic modified carbapenem inactivation method (mCIM), reflexing to the GeneXpert CARBA-R molecular assay if positive; other GNB were tested directly with CARBA-R. Selected GNB underwent susceptibility testing (Sensititre). Whole-genome sequencing was used to assess relatedness among CPO isolates. Swabs from high-risk patients were tested directly by blaKPC PCR (n = 699) until August 2019 (most in parallel with culture) and thereafter by CARBA-R (n = 13). Results: Among 54,188 orders for perirectal swabs, 38,238 were collected from 14,497 patients (compliance 71%). Among 33 CPO-colonized patients identified from September 2013 through September 2019, 15 were identified on admission, 6 were identified in point-prevalence surveys, 8 were identified from high-risk ward surveillance, and 4 were identified from clinical cultures. Sequencing demonstrated no relatedness among CPO isolates. Although only 1.4% of patients sampled on admission were colonized with CPO, those meeting high-risk criteria were 21 times as likely to be colonized. Conclusion: Admission surveillance for CPO identified a low rate of colonization, but it detected nearly half of known CPO-colonized NIHCC patients over the past 6 years. Modest compliance with swab collection leaves room for improvement and likely results in missed instances of colonization. Although we cannot determine its effectiveness, we view our strategy as one of several key safety measures for our highly vulnerable patient population.

Funding: None

Disclosures: None

Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

Field studies were conducted for 4 yr with HOE-39866 [ammonium-(3-amino-3-carboxypropyl)-methylphosphinate] and for 2 yr with SC-0224 (trimethylsulfonium carboxymethylaminomethylphosphonate) to compare foliar activities with those of paraquat (1,1’-dimethyl-4,4’-bipyridinium ion) and glyphosate [N-(phosphonomethyl)glycine] in no-till corn (Zea mays L. ‘Pioneer 3320’ in 1981 and ‘Pioneer 3184’ in 1982 and 1983). Rates evaluated were 0.6 to 1.7 kg ai/ha for all herbicides except paraquat which was included at 0.3 and 0.6 kg ai/ha. Control of rye (Secale cereale L.) was excellent at all rates with SC-0224, paraquat, and glyphosate, but HOE-39866 was effective only when combined with residual herbicides. All four herbicides provided good initial control of horseweed [Conyza canadensis (L.) Cronq., ♯ ERICA], but recovery following paraquat application was extensive. Combinations of HOE-39866, SC-0224, and glyphosate at 0.6 kg/ha with atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] at 1.1 to 1.7 kg ai/ha + metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] at 1.7 kg ai/ha produced antagonistic responses against rye and sometimes horseweed. In 1983, the combination of SC-0224 + residual herbicides provided significantly better control of rye and horseweed 8 days after treatment than the combination of glyphosate + residual herbicides.

Giant ragweed has been increasing as a major weed of row crops in the last30 yr, but quantitative data regarding its pattern and mechanisms of spreadin crop fields are lacking. To address this gap, we conducted a Web-basedsurvey of certified crop advisors in the U.S. Corn Belt and Ontario, Canada.Participants were asked questions regarding giant ragweed and cropproduction practices for the county of their choice. Responses were mappedand correlation analyses were conducted among the responses to determinefactors associated with giant ragweed populations. Respondents rated giantragweed as the most or one of the most difficult weeds to manage in 45% of421 U.S. counties responding, and 57% of responding counties reported giantragweed populations with herbicide resistance to acetolactate synthaseinhibitors, glyphosate, or both herbicides. Results suggest that giantragweed is increasing in crop fields outward from the east-central U.S. CornBelt in most directions. Crop production practices associated with giantragweed populations included minimum tillage, continuous soybean, andmultiple-application herbicide programs; ecological factors included giantragweed presence in noncrop edge habitats, early and prolonged emergence,and presence of the seed-burying common earthworm in crop fields. Managinggiant ragweed in noncrop areas could reduce giant ragweed migration fromnoncrop habitats into crop fields and slow its spread. Where giant ragweedis already established in crop fields, including a more diverse combinationof crop species, tillage practices, and herbicide sites of action will becritical to reduce populations, disrupt emergence patterns, and selectagainst herbicide-resistant giant ragweed genotypes. Incorporation of acereal grain into the crop rotation may help suppress early giant ragweedemergence and provide chemical or mechanical control options forlate-emerging giant ragweed.

A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.

For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.