Time, momentum, and energy resolved pump-probe tunneling spectroscopy of two-dimensional electron systems

Real-time probing of electrons can uncover intricate relaxation mechanisms and many-body interactions in strongly correlated materials. Here, we introduce time, momentum, and energy resolved pump-probe tunneling spectroscopy (Tr-MERTS). The method allows the injection of electrons at a particular energy and observation of their subsequent decay in energy-momentum space. Using Tr-MERTS, we visualize electronic decay processes, with lifetimes from tens of nanoseconds to tens of microseconds, in Landau levels formed in a GaAs quantum well. Although most observed features agree with simple energy-relaxation, we discovered a splitting in the nonequilibrium energy spectrum in the vicinity of a ferromagnetic state. An exact diagonalization study suggests that the splitting arises from a maximally spin-polarized state with higher energy than a conventional equilibrium skyrmion. Furthermore, we observe time-dependent relaxation of the splitting, which we attribute to single-flipped spins forming skyrmions. These results establish Tr-MERTS as a powerful tool for studying the properties of a 2DES beyond equilibrium.

Impact of the COVID-19 pandemic on a post-mortem CT service for adult non-suspicious death

Due to the COVID-19 pandemic, the post-mortem computed tomography (PMCT) service was expanded from three to seven cases per day to help mortuary services and avoid invasive autopsy. Additional targeted angiography and pulmonary ventilation procedures were stopped and triage rules relaxed to allow more indications to be scanned, including those requiring toxicology. A service evaluation was performed for the first 3-months of the COVID-19 pandemic compared to the equivalent period the previous year to study the impact of these changes. It was found that, despite the increase in deaths regionally, coronial referrals remained about 100 per month, a reduction in referral rate. The number undergoing PMCT rose from 28% to 74% of cases. Turnaround time remained the same. For cases triaged to PMCT, the need for subsequent autopsy increased from 7.9% to 15.8%. No significant changes were seen in diagnosis rates, including cardiac or respiratory. There was an increase in patients with coronary death without severe coronary calcification who underwent autopsy after PMCT. These may have been diagnosed by targeted coronary angiography. Fifty-three cases requiring toxicology/biochemistry had PMCT, with 38 having PMCT only. In 8/11 (72.7%) cases with normal PMCT and toxicology as the key diagnostic test, autopsy was performed prior to results. This suggests the pathology team were reluctant to risk an "unascertained" outcome. This study shows that it is possible to increase PMCT services by widening referral criteria and by limiting the use of enhanced imaging techniques, without significantly changing diagnosis rates of key diseases; however, selectively restarting targeted angiography may help avoid autopsy in some cases.

Genealogy of an in-vivo passaged isolate of western Canadian bovine respiratory syncytial virus

Bovine respiratory syncytial virus (BRSV) is a primary respiratory pathogen in calves. Clinical infection with this pathogen has been experimentally modelled to assess vaccine efficacy using a field isolate (Asquith) of BRSV that has been sequentially passaged in vivo in neonatal calves to maintain virulence. The objective of this retrospective cumulative analysis of passages over approximately 20 years was to determine if there have been any changes in the viral genome of this isolate because of this process. Sequence analyses indicated that the Asquith isolate placed genetically in a clade comprising US and some European isolates and a recently described Chinese BRSV isolate (DQ). Furthermore, there were rare changes in bases over time in the N, G, and F gene segments examined when comparing among different passages ranging from 1996 to 2019. These results indicated the absence of significant mutations in the absence of significant adaptive immunological pressure.

Constructing a Plasma Nutriproteome for Population Assessment: Analytical Considerations

Objectives

Micronutrient status is rarely assessed in low-income settings. Proteomics may offer a proxy by measuring plasma proteins correlated with nutrients on a single platform. However, the proteome is huge, diverse and measured in different ways. We describe an analytic framework and decision process to explore nutrient: protein (N:P) associations for micronutrient status assessment.

Methods

In plasma of 435 1st trimester women in rural Bangladesh, we compared relative protein abundance, revealed by a multiplexed slow off-rate modified aptamer assay (SomaLogic, Inc), to biochemical concentrations of vitamins A, D, E, B9, B12, Zn, Se, Cu, I, & Fe, 5 carotenoids, cholesterol and AGP. After log2-transforming protein abundance per convention, N:P relationships were summarized by simple linear regression. We assessed reliability by Pearson correlation (rp) and coefficients of variation (CV) in 20 blind duplicates. To define each plasma nutriproteome [proteins correlating at a false discovery rate < 0.05], in all samples we explored a) normalizing protein abundance to the median of our sample vs not, b) assessing correlations by rp vs Spearman rank (rs) estimators, and c) log2-transforming (log2) nutrients vs not. We compared differences in the number of proteins and N:P correlative strength (either more negative/positive by rp or rs) in each proteome when nutrient concentrations were left untransformed vs log2-transformed.

Results

In duplicates, log2-transformed proteins that were normalized, vs not, to the sample-specific median generated higher median rp (0.92 vs. 0.87) and rs (0.87 vs. 0.85) and lower CV (4.8% vs. 11.7%). The median (IQR) size of the nutriproteomes was 147 (41–340) proteins by rp and 87 (29–639) by rs. For >50% of proteins in 13 nutriproteomes, rp was stronger than rs (in either +/− direction), favoring use of rp. Log2-transforming folate (B9), Zn & cholesterol increased proteome size by 39, 223 & 875 proteins and strengthened rp for >50% of proteins than untransformed nutrients. Other proteomes remained larger when nutrient concentrations remained untransformed.

Conclusions

Comparing plasma protein: nutrient associations via methods of normalization, transformation, and correlation offers a framework to guide plasma nutriproteome definition.

Funding Sources

Johns Hopkins University.

Mid-Gestation Weight Gain Predicts Greater Newborn Size in Rural Bangladesh but the Effect Size Varies by Maternal Nutritional Status and Season

Objectives

Assess association between mid-gestation weight gain and birth size by maternal nutritional status and season.

Methods

During an antenatal micronutrient trial in 2008–12, 14,801 rural Bangladeshi mothers were measured for wt (kg) and ht (cm) < 12 wk gestation [median (IQR): 9 (7–10) wk] and at 32 (32–33) wk, with single, term (37–42 wk gestational age, GA) newborns measured for wt < 72 hours of birth (BW, kg). Mid-gestation rate of wt gain (GWG) per wk was calculated as the difference between maternal wt measures divided by interval length in wk. Initially, BW was modeled as a function of GWG, adjusted for maternal age, body mass index (BMI), parity, height, newborn sex, GA at birth, birth month and wealth index to yield adjusted increments in BW (in kg) per kg of GWG (β^). This outcome was then analyzed and compared between mothers with low (<18.5 kg/m2, n = 4008) vs normal (18.5–24.9, n = 4770) BMI, across seasons of birth [Sep-Nov (season 1, post-monsoon), Dec-Feb (2, winter) and Mar-May (3, hot/dry) and Jun-Aug (4, monsoon)], and between mothers by BMI in each season of birth.

Results

46% of mothers had a BMI < 18.5 and 53% were < 150 cm in ht. Mean GWG per wk was 0.28 kg for thin, and 0.21 kg for normal BMI mothers. Overall, BW was positively associated with GWG per wk [β^ = 0.87 kg; 95% CI: 0.80–0.94], being greater for mothers of low [β^ = 0.84: 0.74–0.94] vs normal [0.68: 0.59–0.77] 1st trimester BMI, and varying by season (β^1 = 0.74, β^2 = 1.06, β^3 = 0.86 and β^4 = 0.78, with 95% CI excluding the average (0.87) for seasons 1 and 2). Comparing β^i between mothers with low vs normal BMI, GWG per wk was associated with a (a) lower mean BW increment in season 1 (0.59 vs 0.82 kg), (b) comparable BW increment in season 2 (β^2 = 1.08 vs 0.99 kg), (c) greater BW increment in season 3 (β^3 = 1 vs 0.68 kg) and the largest incremental difference in season 4 (β^4 = 0.99 vs 0.56 kg) when 95% CIs were exclusive.

Conclusions

Birth weight increased with rate of mid-gestation wt gain, especially for thin vs normal wt mothers. Season of birth modified the association, most clearly during monsoon when food is more secure, aligning with mid-gestation intervals spanning the winter season. Maternal nutritional status and season may alter efficiencies of materno-fetal nutrient/energy transfer reflected by birth weight.

Funding Sources

The Gates Foundation (GH614), Sight and Life and Broadhurst Career Development Professorship.

A Plasma Cuprome Exists With Predictors of Copper Status in Nepalese Children

Objectives

Copper (Cu) is an essential micronutrient but, due to difficulties of measuring Cu by atomic absorption spectroscopy (AAS), plasma Cu status is rarely assessed in low income countries. A less costly assay is needed. We have explored whether plasma Cu concentration can be predicted by modelling strongly associated plasma proteins, assessed by mass spectrometry (MS), that could be assayed with other nutriproteomic biomarkers on one platform in the future.

Methods

In plasma samples from 500 Nepalese children 6–8 y of age, the mean (SD) plasma Cu concentration measured by AAS was 23.3 ± 5.7 mmol/L, with 13.6% classified as deficient (< 10 mmol/L). We quantified relative abundance of 982 plasma proteins by iTRAQ tandem MS following affinity depletion of six high abundance proteins (Cole J Nutr 2013) and correlated their relative abundance with plasma Cu by linear mixed effects regression. We defined a stringent plasma cuprome comprising proteins associated with Cu at a false discovery rate (q) < 0.01. Missing values were imputed and proteins were fit by forward, stepwise regression analysis, meeting an AIC reduction of ≥ 30, to model plasma Cu status.

Results

There were 134 (q < 0.01) proteins in the plasma cuprome. Among 62 positive correlates were ceruloplasm (r = 0.65), 9 complement proteins (r = 0.29 to 0.45), 4 serpin protease inhibitors (r = 0.31 to 0.43) with others involved in coagulation, 5 LRR structural motifs as found in toll-like receptors (r = 0.35 to 0.58), signaling enzymes such as CDC42BPA (r = 0.70) and proinflammatory reactants and regulators such as CRP, AGP, amyloids and TNIP1 (r = 0.40 to 0.56). Among 72 negative correlates (r = −0.29 to −0.42) are lipid and sterol binding and transport proteins including apolipoproteins/lipocalins, enzyme regulating proteins, extracellular adhesion, signaling and matrix proteins. Different members of serine peptidase inhibitor members were among + and – correlates. Forward stepwise regression fit 6 proteins (CP, CDC42BPA, LRRC47, TDRD9, LLRIQ1, LRRCC1) that explain 76.5% of the variance (R2) in plasma Cu, sufficient for predicting plasma Cu status of a population.

Conclusions

A large, diverse plasma cuprome exists, as revealed in young Nepalese children, from which six proteins may adequately predict plasma Cu status.

Funding Sources

Bill & Melinda Gates Foundation (OPPGH5241) & Johns Hopkins University.

Characteristics and birth outcomes of pregnant adolescents compared to older women: An analysis of individual level data from 140,000 mothers from 20 RCTs

BACKGROUND

Adolescence is a critical period of maturation when nutrient needs are high, especially among adolescents entering pregnancy. Using individual-level data from 140,000 participants, we examined socioeconomic, nutrition, and pregnancy and birth outcomes for adolescent mothers (10-19 years) compared to older mothers in low and middle-income countries.

METHODS

This study was conducted between March 16, 2018 and May 25, 2021. Data were obtained from 20 randomised controlled trials of micronutrient supplementation in pregnancy. Stratified analyses were conducted by age (10-14 years, 15-17 years, 18-19 years, 20-29 years, 30-39 years, 40+ years) and geographical region (Africa, Asia). Crude and confounder-adjusted means, prevalence and relative risks of pregnancy, nutrition and birth outcomes were estimated using multivariable linear and log-binomial regression models with 95% confidence intervals.

FINDINGS

Adolescent mothers comprised 31.6% of our data. Preterm birth, small-for-gestational age (SGA), low birthweight (LBW) and newborn mortality followed a U-shaped trend in which prevalence was highest among the youngest mothers (10-14 years) and then reduced gradually, but increased again for older mothers (40+ years). When compared to mothers aged 20-29 years, there was a 23% increased risk of preterm birth, a 60% increased risk of perinatal mortality, a 63% increased risk of neonatal mortality, a 28% increased risk of LBW, and a 22% increased risk of SGA among mothers 10-14 years. Mothers 40+ years experienced a 22% increased risk of preterm birth and a 103% increased risk of stillbirth when compared to the 20-29 year group.

INTERPRETATION

The youngest and oldest mothers suffer most from adverse pregnancy and birth outcomes. Policy and programming agendas should consider both biological and socioeconomic/environmental factors when targeting these populations.

FUNDING

Bill and Melinda Gates Foundation (Grant No: OP1137750).

Collective Excitations of Exciton-Polariton Condensates in a Synthetic Gauge Field

Collective (elementary) excitations of quantum bosonic condensates, including condensates of exciton polaritons in semiconductor microcavities, are a sensitive probe of interparticle interactions. In anisotropic microcavities with momentum-dependent transverse-electric-transverse-magnetic splitting of the optical modes, the excitations' dispersions are predicted to be strongly anisotropic, which is a consequence of the synthetic magnetic gauge field of the cavity, as well as the interplay between different interaction strengths for polaritons in the singlet and triplet spin configurations. Here, by directly measuring the dispersion of the collective excitations in a high-density optically trapped exciton-polariton condensate, we observe excellent agreement with the theoretical predictions for spinor polariton excitations. We extract the interaction constants for polaritons of the same and opposite spin and map out the characteristic spin textures in an interacting spinor condensate of exciton polaritons.

Enhancement of Parametric Effects in Polariton Waveguides Induced by Dipolar Interactions

Exciton-polaritons are hybrid light-matter excitations arising from the nonperturbative coupling of a photonic mode and an excitonic resonance. Behaving as interacting photons, they show optical third-order nonlinearities providing effects such as optical parametric oscillation or amplification. It has been suggested that polariton-polariton interactions can be greatly enhanced by inducing aligned electric dipoles in their excitonic part. However, direct evidence of a true particle-particle interaction, such as superfluidity or parametric scattering, is still missing. In this Letter, we demonstrate that dipolar interactions can be used to enhance parametric effects such as self-phase modulation in waveguide polaritons. By quantifying these optical nonlinearities, we provide a reliable experimental measurement of the direct dipolar enhancement of polariton-polariton interactions.

Extensive mucocutaneous, oesophageal and otic lichen planus secondary to nivolumab therapy

We report a 73-year-old female with metastatic renal cell carcinoma who developed a widespread lichenoid reaction following nivolumab treatment. The timeline of the reaction strongly correlated with the nivolumab treatment and subsequent cessation. Our patient had cutaneous, mucosal, otic, ophthalmic and oesophageal involvement, demonstrating the potentially extensive nature of lichenoid reactions to anti-programmed cell death receptor-1 (anti-PD1) therapies. Although lichenoid reactions to anti-PD1 therapies are now well recognized, there have been no previous reports of otic or oesophageal involvement in the literature. Although cutaneous lichenoid reactions do not tend to be severe or treatment limiting, more widespread systemic lichenoid reactions are challenging to manage, particularly in the context of malignancy. This very unusual case highlights the importance of considering involvement beyond the skin in all lichenoid skin reactions.

Low-Energy Collective Oscillations and Bogoliubov Sound in an Exciton-Polariton Condensate

We report the observation of low-energy, low-momenta collective oscillations of an exciton-polariton condensate in a round "box" trap. The oscillations are dominated by the dipole and breathing modes, and the ratio of the frequencies of the two modes is consistent with that of a weakly interacting two-dimensional trapped Bose gas. The speed of sound extracted from the dipole oscillation frequency is smaller than the Bogoliubov sound, which can be partly explained by the influence of the incoherent reservoir. These results pave the way for understanding the effects of reservoir, dissipation, energy relaxation, and finite temperature on the superfluid properties of exciton-polariton condensates and other two-dimensional open-dissipative quantum fluids.

Infection of calves with in-vivo passaged bovine parainfluenza-3 virus, alone or in combination with bovine respiratory syncytial virus and bovine coronavirus

Bovine respiratory disease complex is etiologically complex and usually involves co-infection by several agents, including bovine parainfluenza virus-3 (BPIV-3), bovine respiratory syncytial virus (BRSV), and bovine coronavirus (BCoV). Traditionally, vaccines have been tested in seronegative calves infected with a single in vitro-passaged agent, often with little disease, resulting in unvaccinated subjects. To overcome the potential problem of attenuation coincident with in vitro culture of the viruses, cocktails of field isolates of BPIV-3s and BCoVs were passaged in the lungs of neonatal colostrum-deprived calves. Lung lavage fluids were used as inocula, alone and in combination with in-vivo passaged BRSV, and aerosolized into a trailer containing conventionally reared 9-week-old weaned Holstein calves with decayed, but still measurable, maternal antibodies. Calves developed acute respiratory disease of variable severity. Upon necropsy, there were characteristic gross and histologic lesions in the respiratory tract, associated immunohistochemically with BPIV-3, BRSV, and BCoV. In-vivo passage of viruses is an alternative to in vitro culture to produce inocula to better study the pathogenesis of infection and more rigorously and relevantly assess vaccine efficacy.

Vitamin E Deficiency Is Associated with Reduced Handgrip Strength in Rural Nepalese Children

Objectives

Vitamin E deficiency (VED), common in areas of rural South Asia, can affect neuromuscular health. This study determined the extent of VED and its association with neuromuscular function, indicated by hand grip strength, in Nepalese school aged children.

Methods

This cross-sectional study was conducted in a birth cohort of 6–8 year old children, born during an earlier maternal micronutrient trial, in Sarlahi District in the southern plains (Tarai) of Nepal. Assessments included anthropometry (height, weight, MUAC), handgrip strength by hydraulic dynamometry, plasma α- and γ-tocopherol concentrations by HPLC, other nutritional and inflammatory biomarkers, diet and SES. Data were analyzed using descriptive, bivariate and multivariable regression analyses.

Results

In 998 children, mean (+SD) α- and γ-tocopherol levels were 12.21 (+3.27) μmol/L and 1.50 (+0.70), μmol/L respectively. α-Tocopherol distributions were comparable in females (12.34 ± 3.29 μmol/L) and males (12.09 ± 3.24), with 51.9% of all children classified as VED (plasma α-tocopherol &lt; 12 μmol/L). Plasma γ-tocopherol was higher in females than males (1.56 ± 0.72 vs 1.44 ± 0.67, P &lt; 0.01). Handgrip strength (in kg) was higher in males (7.25 ± 2.14) than females (6.44 ± 2.00) (P &lt; 0.001), which also increased with age. In a continuous multivariable model, adjusted for sex and age, handgrip strength increased with plasma α-tocopherol (βα = 0.054 kg/μmol/L (95% CI: 0.0149–0.0926), P &lt; 0.001). Age-sex adjusted handgrip strength was 0.328 (95% CI: 0.015–0.093) kg lower in VED vs non-deficient children (P &lt; 0.01), but was unrelated to plasma γ-tocopherol. There were no interactions in handgrip strength and vitamin E status by sex.

Conclusions

Vitamin E deficiency is common and is associated with neuromuscular weakness in young, school aged children in southern Nepal, evident by a lower handgrip strength.

Funding Sources

Funded by The Bill and Melinda Gates Foundation (GH614, OPP5241), Seattle, WA with assistance from the Sight and Life Global Nutrition Research Institute, Baltimore, MD.

Impact of Protein Supplementation and Presumptive Treatment for Enteric Pathogens on Infant Growth from 6–12 Months of Age: Results of a Cluster-Randomized Controlled Trial

Objectives

Intake of high-quality protein may be insufficient to support growth in the context of high enteric pathogen carriage and environmental enteric dysfunction. Our objective was to test whether supplemental protein, with or without presumptive treatment for enteric pathogens, would improve infant growth from 6–12 months of age.

Methods

We conducted a 2 × 4 factorial cluster-randomized trial in rural Bangladesh. The first factor was azithromycin treatment (10 mg/kg * 3 days) or placebo at 6 & 9 months of age. The second factor, delivered from 6–12 months of age, consisted of: supplemental protein as daily porridge (125 kcal/d, with 10 g protein/day as egg white powder) or a daily egg; an isocaloric daily porridge; or nutrition education alone. The present aim tested the impact of the protein-rich porridge, with or without azithromycin treatment. All infants born in the study area over a 9-mo period were eligible and consented at ∼3 mo of age. Trained field workers measured infant size at 6, 9, and 12 mo of age using standardized protocols. We used linear regression with generalized estimating equations to test the interventions’ impact on anthropometric indices, respectively, at 12 mo of age, controlling for baseline measures. Analysis was intention-to-treat.

Results

Overall, 2205 infants were enrolled from 282 clusters and exposed to both nutrition (1074 in protein arm from 140 clusters; 1074 in the isocaloric arm from 142 clusters) and presumptive treatment interventions. At baseline, 18.7%, 16.9%, and 6.4% of infants were stunted, underweight, and wasted, respectively. There was no statistical interaction between protein supplementation and azithromycin treatment for any of the anthropometric indices, so groups were combined. In the analysis of main effects, added protein had no impact on mean length-for-age (β = 0.01; 95% CI: −0.06, 0.08), weight-for-age (β = −0.002; 95% CI: −0.06, 0.05), or weight-for-length (β = −0.04; 95% CI: −0.12, 0.05) Z-scores at 12 mo of age.

Conclusions

Supplemental protein from 6–12 mo of age had no effect on mean linear or ponderal growth measured at 12 mo of age, irrespective of presumptive treatment for enteric pathogens with azithromycin.

Funding Sources

The Bill and Melinda Gates Foundation.

Trends in Prelacteal Feeding Practices in Rural Bangladesh from 2004–2019

Objectives

Our objective was to assess changes in prelacteal feeding practices in rural Bangladesh over a 15-year period, from ∼2004 to ∼2019, and to identify household, maternal, and infant characteristics associated with that trend.

Methods

The analysis used data from 21,804 infants enrolled in a cluster-randomized controlled trial of newborn vitamin A supplementation from 2004–2006, and from 4631 infants enrolled in a cluster-randomized controlled trial of a digital health intervention from 2018–2019. In both studies, trained field workers collected data on household socioeconomic status and maternal demographic characteristics at the time of enrollment. Upon receiving notification of an infant's birth, field workers visited the home as soon as possible, collecting detailed data on breastfeeding initiation and any foods or liquids other than breast milk provided to the infant. Prelacteal feeding was defined as giving infants any food or liquid other than breast milk within first 3 days of life. We used bivariate and multivariate logistic regression analyses to examine the association between different household, maternal, and infant characteristics and prelacteal feeding. We then applied a regression decomposition method to understand the factors associated with the changing prevalence of prelacteal feeding over time.

Results

The prevalence of prelacteal feeding was 88.0% during the period of 2004–2006. Among women practicing prelacteal feeding, sugar/sugar candy water was the most commonly fed prelacteal (41.2%), followed by animal milk (40.0%), honey (35.4%), and drops (11.8%). By 2018–2019, the prevalence of prelacteal feeding had declined to 24.7%. Most frequently consumed prelacteals were most commonly sugar/sugar candy water (20.0%), honey (20.0%), animal milk (19.7%), and drops (14.3%). Final analysis will include examination of the changing factors associated with this decline including rising maternal education, improvements in socioeconomic status, and exposure to media.

Conclusions

The prevalence of prelacteal feeding has dropped considerably in rural Bangladesh since 2004.

Funding Sources

The Bill and Melinda Gates Foundation; United States Agency for International Development; Sight and Life.

Association Between Prelacteal Feeding and Infant Growth

Objectives

To assess the association between exposure to prelacteal feeding and infant growth from birth to 3 months of age.

Methods

We analyzed data from a cohort of mothers and infants (n = 2569) identified as part of ongoing pregnancy and birth surveillance in rural Gaibandha, Bangladesh. Trained interviewers visited women in their households during pregnancy to collect sociodemographic data. Project staff were notified of a birth by telephone and interviewers visited the home within three days post-partum, at one-week, and at three months. At each visit, interviewers collected detailed data on breastfeeding, any foods provided to the infant other than breast milk, and morbidity. Infant weight, length, and mid-upper arm circumference were measured according to standardized protocols at birth and three months of age. For analysis, we defined exposure to prelacteal feeding (PLF) as giving infants any food or liquid other than breastmilk within first 3 days of life. Infant length and weight measurements were used to produce length-for-age (LAZ), weight-for-age (WAZ), and weight-for-length (WLZ) Z-scores. Stunting, wasting, and underweight were defined as a LAZ, WLZ, or WAZ &lt; −2, respectively. We used multiple linear regression and multiple logistic regression to assess the association between anthropometric indices and PLF practices, controlling for low birthweight, infant sex, infant age, maternal education, maternal age, and wealth.

Results

The prevalence of PLF was 25.2%. The prevalence of stunting, wasting and underweight was 29.0%, 3.8% and 22.3%, respectively. For stunting (adjusted risk ratio (ARR) = 1.02 [95% CI: 0.89–1.16]) and wasting (ARR = 0.97 [95% CI: 0.63–1.50]), there were no differences between infants who received PLF and infants who did not receive any PLF. Infants who received PLF tended to have higher risk of underweight (ARR = 1.10 [95% CI: 0.95–1.28]). For LAZ, WAZ, and WLZ score, no differences were observed in the adjusted analysis between infants who received PLF and those who did not receive any PLF.

Conclusions

There was no association between exposure to PLF and infant growth from birth to 3 months of age. More research is needed to explore the potential effect of PLF on other outcomes.

Funding Sources

Bill & Melinda Gates Foundation; Johnson & Johnson; UBS Optimus Foundation.

The Effect of Eggs on Growth Among Infants 6–12 months of Age in Rural Bangladesh: A Cluster Randomized Controlled Trial

Objectives

To assess the impact of daily egg supplementation on infant growth from 6–12 months of age in Bangladesh.

Methods

A cluster randomized controlled trial was conducted in rural Bangladesh to test the effect of daily egg supplementation and nutrition education versus nutrition education alone on linear growth and stunting prevalence among infants. Infants were enrolled at 3 months of age and assigned to a trial arm based on their geographic sector of residence. Households were visited weekly to distribute eggs and monitor compliance starting at 6 months of age. Length, weight, head circumference, and mid upper arm circumference were measured at 6, 9, and 12 months, as well as dietary intake from home foods in the last 24 hours. Analyses were conducted on an intention-to-treat basis. Linear regression models were developed for continuous outcomes. For dichotomous outcomes, prevalence ratios were estimated using log-binomial regression models. Generalized estimating equations were used with all models to account for clustering. Each model was adjusted for the baseline measure of the outcome variable.

Results

Overall, 909 infants were enrolled in the treatment arm from 142 clusters and 842 infants in the control arm from 140 clusters. Prevalence of stunting at baseline was 19.4%, wasting was 6.7%, and underweight was 18.1%. After 6 months of supplementation, the intervention had no effect on mean length-for-age z-scores (β = 0.05, 95% CI: −0.12, 0.23) or prevalence of stunting (PR = 1.00, 95% CI: 0.90, 1.10). Infants in the egg arm had significantly higher mean weight-for-length z-scores (β = 0.11, 95% CI: 0.04, 0.18) and weight-for-age z-scores (β = 0.08, 95% CI: 0.03, 0.12), adjusting for baseline measures of the outcomes. Our presented results will include findings from mixed-effects regression analyses assessing the effect of the intervention on growth rate.

Conclusions

The provision of a daily egg for 6 months to infants in rural Bangladesh had an effect on ponderal but not linear growth.

Funding Sources

Bill and Melinda Gates Foundation.

Acoustoelectric Study of Microwave-Induced Current Domains

Surface acoustic waves (SAW) have been utilized to investigate the properties of a two-dimensional electron system subjected to a perpendicular magnetic field and monochromatic microwave radiation in the regime where the so-called microwave-induced zero-resistance states form. Contrary to conventional magnetotransport in Hall bar and van der Pauw geometries, the collimated SAW beam probes only the bulk of the electronic system exposed to this wave. Clear signatures appear in the SAW propagation velocity, corroborating that neither contacts nor sample edges are a root source for their emergence. By virtue of the directional nature of this probing method and with the assistance of theoretical modeling, we were able to demonstrate that the SAW response depends on the angle between its propagation vector and the orientation of domains that spontaneously form when zero-resistance is observed in transport. This confirms in unprecedented manner the formation of an inhomogeneous phase under these nonequilibrium conditions.

Setting research priorities on multiple micronutrient supplementation in pregnancy

Prenatal micronutrient deficiencies are associated with negative maternal and birth outcomes. Multiple micronutrient supplementation (MMS) during pregnancy is a cost-effective intervention to reduce these adverse outcomes. However, important knowledge gaps remain in the implementation of MMS interventions. The Child Health and Nutrition Research Initiative (CHNRI) methodology was applied to inform the direction of research and investments needed to support the implementation of MMS interventions for pregnant women in low- and middle-income countries (LMIC). Following CHNRI methodology guidelines, a group of international experts in nutrition and maternal health provided and ranked the research questions that most urgently need to be resolved for prenatal MMS interventions to be successfully implemented. Seventy-three research questions were received, analyzed, and reorganized, resulting in 35 consolidated research questions. These were scored against four criteria, yielding a priority ranking where the top 10 research options focused on strategies to increase antenatal care attendance and MMS adherence, methods needed to identify populations more likely to benefit from MMS interventions and some discovery issues (e.g., potential benefit of extending MMS through lactation). This exercise prioritized 35 discrete research questions that merit serious consideration for the potential of MMS during pregnancy to be optimized in LMIC.

Monitoring and evaluation design of Malawi's Right Foods at the Right Time nutrition program

Child stunting is a public health problem in Malawi. In 2014, the Government of Malawi launched the Right Foods at the Right Time (RFRT) program in Ntchisi district delivering nutrition social and behavior change communication, a small-quantity lipid-based nutrient supplement to children 6-23 months, and nutrition sensitive activities. Monitoring and evaluation (M&E) systems are key aspects of successful program implementation. We describe these and the methodology for an impact evaluation that was conducted for this program. Two monitoring systems using traditional and electronic platforms were established to register and track program delivery and processes including number of eligible beneficiaries, worker performance, program participation, and to monitor input, output, and outcome indicators. The impact evaluation used comparative cross-sectional and longitudinal designs to assess impact on anthropometric and infant and young child feeding outcomes. Three cross-sectional surveys (base-, mid-, and end-line) and two longitudinal cohorts of children followed in 6-month intervals from 6 to 24 months of age, were conducted in sampled households in the program and a neighboring comparison district. Additional M&E included qualitative studies, a process evaluation, and a cost-effectiveness study. The current paper describes lessons from this program's M&E, and demonstrates how multiple implementation research activities can inform course-correction and program scale-up.

Chiral Modes at Exceptional Points in Exciton-Polariton Quantum Fluids

We demonstrate the generation of chiral modes-vortex flows with fixed handedness in exciton-polariton quantum fluids. The chiral modes arise in the vicinity of exceptional points (non-Hermitian spectral degeneracies) in an optically induced resonator for exciton polaritons. In particular, a vortex is generated by driving two dipole modes of the non-Hermitian ring resonator into degeneracy. Transition through the exceptional point in the space of the system's parameters is enabled by precise manipulation of real and imaginary parts of the closed-wall potential forming the resonator. As the system is driven to the vicinity of the exceptional point, we observe the formation of a vortex state with a fixed orbital angular momentum (topological charge). This method can be extended to generate higher-order orbital angular momentum states through coalescence of multiple non-Hermitian spectral degeneracies. Our Letter demonstrates the possibility of exploiting nontrivial and counterintuitive properties of waves near exceptional points in macroscopic quantum systems.

The colored Hanbury Brown-Twiss effect

The Hanbury Brown-Twiss effect is one of the celebrated phenomenologies of modern physics that accommodates equally well classical (interferences of waves) and quantum (correlations between indistinguishable particles) interpretations. The effect was discovered in the late thirties with a basic observation of Hanbury Brown that radio-pulses from two distinct antennas generate signals on the oscilloscope that wiggle similarly to the naked eye. When Hanbury Brown and his mathematician colleague Twiss took the obvious step to propose bringing the effect in the optical range, they met with considerable opposition as single-photon interferences were deemed impossible. The Hanbury Brown-Twiss effect is nowadays universally accepted and, being so fundamental, embodies many subtleties of our understanding of the wave/particle dual nature of light. Thanks to a novel experimental technique, we report here a generalized version of the Hanbury Brown-Twiss effect to include the frequency of the detected light, or, from the particle point of view, the energy of the detected photons. Our source of light is a polariton condensate, that allows high-resolution filtering of a spectrally broad source with a high degree of coherence. In addition to the known tendencies of indistinguishable photons to arrive together on the detector, we find that photons of different colors present the opposite characteristic of avoiding each others. We postulate that fermions can be similarly brought to exhibit positive (boson-like) correlations by frequency filtering.

Immunohistochemical Evaluation of Mononuclear Infiltrates in Canine Lupoid Onychodystrophy

Claw biopsy samples of 11 dogs with lupoid onychodystrophy were evaluated. They were stained with hematoxylin and eosin and with antibodies against CD 3 as a T-cell marker, BLA 36 and HM 57 (CD 79α) as B-cell markers, and lysozyme, Mac 387, and major histocompatibility complex (MHC) class II as a marker for histiocytes using an immunoperoxidase and avidin-biotin technique. Inflammatory cells were counted in five high-power fields. The inflammatory infiltrate comprised predominantly B cells and T cells. Macrophages were typically only present in small numbers. CD 3, BLA 36, lysozyme, and MHC class II preserved significant antigenicity during formalin fixation and short decalcification for 24–48 hours, whereas CD 79α and particularly Mac 387 seemed to be more susceptible to denaturation by the decalcification process.

An Outbreak of Sheep-Associated Malignant Catarrhal Fever in Bison (Bison Bison) after Exposure to Sheep at a Public Auction Sale

An outbreak of malignant catarrhal fever (MCF) among bison sold at an auction market was studied for an 18-month period. Forty-five of 163 bison submitted for sale from 8 different bison farms died on 7 other destination farms. The outbreak began on day 50 after the sale, peaked between days 60 and 70, and ended on day 220. Twenty-one dead bison were confirmed to be MCF cases by clinical histories, pathology, and detection of ovine herpesvirus-2 DNA in their tissues with polymerase chain reaction assays. Twenty-four dead bison were classified as suspect MCF cases from clinical histories. No cases of MCF were observed among bison remaining on originating farms or resident bison mixed with sale bison on destination farms. There were no sheep reported within 3 km of originating or destination farms, limiting bison exposure to sheep to the auction facility, where sheep were present for less than 1 day. The outbreak provides an illustration of the temporal distribution of MCF mortality expected in bison and an estimate of the time from exposure until death from MCF after a single short exposure to sheep. The study provides evidence that bison with MCF do not transmit MCF to other bison.

An assessment of West African seahorses in fisheries catch and trade

This study provides the first assessment of a heavily traded West African seahorse species, Hippocampus algiricus, and the first information on short-snouted seahorse Hippocampus hippocampus biology in Africa. A total of 219 seahorses were sampled from fisher catch in Senegal and The Gambia, with estimated height at reproductive activity for H. algiricus (161 mm) larger than mean ± S.D. catch height (150 ± 31 mm). Catch composition, height at reproductive activity and potential biases in fishery retention are discussed with regard to the current Convention on International Trade of Endangered Species (CITES) guidelines.

The Association of Cytokines and Micronutrients with Hepatitis E Virus Infection During Pregnancy and the Postpartum Period in Rural Bangladesh

Hepatitis E virus (HEV) infection is severe during pregnancy, with a pregnant case fatality rate around 30%. In Bangladesh, plasma samples from 1,100 women during the first trimester (TM) and third TM of pregnancy and 3 months postpartum (PP) were tested for anti-HEV IgG. During this time, 40 women developed antibody responses to HEV. These seroconverters are classified as the cases (incidence = 46 infections per 1,000 person-years). All except one seroconversion occurred between the third TM and 3 months PP. The cases and 40 matched non-seroconverters (controls) underwent analysis of a panel of 10 cytokines, 12 vitamins and minerals, and two markers of inflammation. Throughout pregnancy, seroconverting cases displayed higher concentrations of both pro- and anti-inflammatory cytokines compared with the non-seroconverting controls, even prior to infection. In the first TM, seroconverters had lower circulating zinc concentrations (P = 0.03), an increased prevalence of vitamin D deficiency (25-hydroxy vitamin D [25(OH)2D] < 50 nmol/L, P = 0.08), and anemia (hemoglobin < 110 g/L, P = 0.05) compared with controls. There were no differences in C-reactive protein or α-1-acid glycoprotein. Antecedent micronutrient deficiencies may lead to dysregulated cytokine expression and immunologic compromise, increasing the risk of HEV infection, especially during pregnancy. This exploratory analysis reveals potential novel associations that deserve further study.

Identification of high-risk Dukes B colorectal cancer by microRNA expression profiling: a preliminary study

AIM

MicroRNAs (miRNAs) from tumour tissue and common gene mutations were studied to determine whether they predict the development of metastasis in patients with Dukes B colorectal cancer.

METHOD

Patients who underwent curative resection for Dukes B colorectal cancer who subsequently developed distant metastatic disease at some stage in the following 5 years ('high-risk B') were compared with case-matched controls of Dukes A, Dukes B (no metastases, 'low-risk B') and Dukes C patients without any detectable metastasis at 5 years of follow-up. MiRNAs from tumour and adjacent normal tissue and common gene mutations (KRAS, BRAF, PIK3CA) in primary cancer tissue were analysed to identify prognostic tissue markers for the development of metastasis in patients with Dukes B colorectal cancer.

RESULTS

Expression of miR-15b and miR-135b was significantly downregulated (P < 0.001) in 'high-risk B' tumours compared with Dukes A, 'low-risk B' and C without metastasis. No significant differences were noted for mutation status and the development of metastasis.

CONCLUSION

The study suggests that the development of metastasis in Dukes B tumours may be predictable based on the miRNA expression of miR-15b and miR-135b. This requires further study on a much larger cohort.