Parent feeding practices in infants and toddlers referred to a hospital-based feeding program in the United States.

While considerable research exists on parent feeding practices for infants and toddlers, past research has not focused on children with feeding problems. The goal of this study was to identify parent feeding practices in a sample of infants (n = 178) and toddlers (n = 221) referred to a hospital-based feeding clinic and then examine how these parent feeding practices were correlated with specific feeding problems. Parents completed surveys to report child demographics, feeding problems, and use of 54 feeding practices. Forty-eight (88.8%) of 54 practices were utilized more often for toddlers than for infants. Exploratory factor analysis with the 54 practices and the full sample (n = 399) produced the 16-item Baby Parent Mealtime Action Scale (BPMAS) with three dimensions: Multiple Food Offers, Use of Cereal/Pureed Foods, Use of Toys/TV. Controlling for demographics, hierarchical regression examined how each BPMAS dimension was associated with five feeding problems (underweight, tube feeding, texture problems, limited diet, mealtime disruption). Multiple Food Offers (e.g., daily offering of vegetables, offering foods from the family meal) was the dimension most correlated with fewer feeding problems such as tube feeding (ß = -0.220, p < 0.001), texture rejection (ß = -0.361, p < 0.001), and limited diet variety (ß = -0.175, p < 0.001), but also with more mealtime disruption (ß = 0.231, p < 0.001). Use of Toys/TV was correlated with more mealtime disruption (ß = 0.260, p < 0.001). In addition to demonstrating a correlation between parent feeding practices and feeding problems, this study also found adding cereal/pureed foods to be common and while the dimension, Use of Cereal/Pureed Foods, was not significantly correlated with any specific feeding problem, this dimension provides an expanded understanding of cereal usage.

Abundant and persistent sulfur-oxidizing microbial populations are responsive to hypoxia in the Chesapeake Bay.

The number, size and severity of aquatic low-oxygen dead zones are increasing worldwide. Microbial processes in low-oxygen environments have important ecosystem-level consequences, such as denitrification, greenhouse gas production and acidification. To identify key microbial processes occurring in low-oxygen bottom waters of the Chesapeake Bay, we sequenced both 16S rRNA genes and shotgun metagenomic libraries to determine the identity, functional potential and spatiotemporal distribution of microbial populations in the water column. Unsupervised clustering algorithms grouped samples into three clusters using water chemistry or microbial communities, with extensive overlap of cluster composition between methods. Clusters were strongly differentiated by temperature, salinity and oxygen. Sulfur-oxidizing microorganisms were found to be enriched in the low-oxygen bottom water and predictive of hypoxic conditions. Metagenome-assembled genomes demonstrate that some of these sulfur-oxidizing populations are capable of partial denitrification and transcriptionally active in a prior study. These results suggest that microorganisms capable of oxidizing reduced sulfur compounds are a previously unidentified microbial indicator of low oxygen in the Chesapeake Bay and reveal ties between the sulfur, nitrogen and oxygen cycles that could be important to capture when predicting the ecosystem response to remediation efforts or climate change.

Effect of intermittent access to alcohol mixed in energy drink during adolescence on alcohol self-administration, anxiety, and memory during adulthood in rats.

BACKGROUND: Mixing alcohol with caffeinated energy drinks is a common practice among young people. Consumption of alcohol mixed in energy drink is associated with increased risk of binge drinking and alcohol dependence. The purpose of this study was to determine whether voluntary intermittent access to alcohol mixed in energy drink in adolescent rats alters adult self-administration of alcohol, anxiety, and memory. METHODS: For 10 weeks in the home-cage, two groups of adolescent female Sprague-Dawley rats had intermittent access to energy drink (ED) or 10% alcohol mixed in energy drink (AmED) with water concurrently available. Other rat groups had daily continuous access to ED or AmED. Anxiety was measured with an open field test and memory was assessed with a novel place recognition test. For self-administration, rats pressed levers for 10% alcohol alone on a fixed ratio (FR1) and on a progressive ratio (PR). RESULTS: Intermittent access to AmED generated greater intake during the initial 30 min of access (AmED 1.70 ± 0.04 g/kg vs. ED 1.01 ± 0.06 g/kg) and during the subsequent 24 h (AmED 7.04 ± 0.25 g/kg vs. ED 5.60 ± 0.29 g/kg). Intermittent AmED caused a significant but small decrease in anxiety while neither ED nor AmED altered memory. During alcohol self-administration, group differences emerged only during PR testing during which intermittent AmED rats responded more than all other groups. CONCLUSIONS: These findings suggest that intermittent access to AmED generates binge-like consumption that supports human findings that AmED generates greater alcohol consumption. Furthermore, experience with AmED may alter the motivational properties of alcohol into adulthood without necessarily causing a major impact on anxiety or memory.

Cross-cultural representations of conjoined twins.

Conjoined twinning is a rare birth defect estimated to occur in about 1 in 50,000 to 100,000 births. The mechanism of conjoined twinning is not proven. Different forms of conjoined twinning are observed with the thoracopagus form being the most common. The rate of conjoined twinning is similar across all major populations. A dramatic malformation of this type would be an extraordinary occurrence leading people to reflect on the spiritual or supernatural nature of such an event. Therefore, it is not surprising that artifacts that seem to depict different forms of conjoined twins are seen across diverse cultures. In this article, we present a survey of these cultural artifacts including anatomic classification based on external anatomy and an exploration of the cultural and spiritual contexts associated with the artifacts. A key finding is that the most common form of conjoined twinning in the artifacts is parapagus (both dicephalus and diprosopus) in contrast to thoracopagus, the most common form in epidemiologic studies. Potential reasons for this difference are discussed. Evidence is presented to support the speculation that these objects represent artistic impressions of actual conjoined twinning events.

Impact of nonlinearity including bleaching in MUTC photodetectors on RF-modulated electro-optic frequency combs.

We use the drift-diffusion equations to calculate the responsivity of a modified uni-traveling carrier (MUTC) photodetector (PD) with a frequency comb input that is generated by a series of short optical pulses. We first use experimental results for the responsivity of the MUTC PD to obtain an empirical model of bleaching in pulsed mode. We incorporate our empirical bleaching model into a drift-diffusion model to calculate the impact of nonlinearity in an MUTC PD on RF-modulated electro-optic frequency combs. We quantify the nonlinearity using the second- and third-order intermodulation distortion powers (IMD2 and IMD3), from which we calculate the second- and third-order output intercept points (OIP2 and OIP3). In contrast to a continuous wave (CW) input for which there is a single IMD2 and IMD3 and hence a single OIP2 and OIP3, each comb line n has its own IMD2n, IMD3n, OIP2n, and OIP3n associated with it. We determine the IMD2n, IMD3n, OIP2n, and OIP3n, and we compare the results with and without bleaching. We find that the impact of bleaching is complex and, somewhat surprisingly, not always detrimental. The principal effect of bleaching is to lower the responsivity, which decreases the nonlinearity due to space charge. While bleaching always reduces the OIP2n and OIP3n, we find that bleaching leads to a decreased distortion-to-signal ratio for large n.

Comparison of the impact of nonlinearity in a p-i-n and an MUTC photodetector on electro-optic frequency combs.

We calculate the impact of nonlinearity in both a p-i-n photodetector (PD) and a modified uni-traveling carrier (MUTC) PD on an RF-modulated frequency comb generated using 100-fs optical pulses with a 50-MHz repetition rate. We take into account bleaching (nonlinear saturation) that is due to the high peak-to-average-power ratio and contributes to the device nonlinearity. Nonlinear impairment of an RF-modulated continuous wave is typically characterized by the second- and third-order intermodulation distortion products (IMD2 and IMD3). In contrast, an RF-modulated frequency comb must be characterized by a distinct IMD2n and IMD3n for each comb line n. We calculate IMD2n and IMD3n in both p-i-n and MUTC PDs and compare the results. We also calculate the ratio of the IMD2n power and the IMD3n power to the fundamental power Sin in both p-i-n and MUTC PDs. We find that nonlinear distortion has a greater impact at high frequencies in the MUTC PD than in the p-i-n PD.

Regulation of TRPC5 currents by intracellular ATP: Single channel studies.

TRPC5 channels are nonselective cation channels activated by G-protein-coupled receptors. It was previously found that recombinant TRPC5 currents are inhibited by intracellular ATP, when studied by whole-cell patch-clamp recording. In the present study, we investigated the mechanism of ATP inhibition at the single-channel level using patches from HEK-293 cells transiently transfected with TRPC5 and the M1 muscarinic receptor. In inside-out patches, application of ATP to the intracellular face of the membrane reduced TRPC5 channel activity at both positive and negative potentials without affecting the unitary current amplitude or open dwell time of the channel. The effect of ATP was rapidly reversible. These results suggest that ATP may bind to the channel protein and affect the ability of the channel to open or to remain in an open, nondesensitized state. The activity of TRPC5 channels may be influenced by cellular metabolism via changes in ATP levels.

Contribution of Time, Taxonomy, and Selective Antimicrobials to Antibiotic and Multidrug Resistance in Wastewater Bacteria.

The use of nontherapeutic broad-spectrum antimicrobial agents triclosan (TCS) and benzalkonium chloride (BC) can contribute to bacterial resistance to clinically relevant antibiotics. Antimicrobial-resistant bacteria within wastewater may reflect the resistance burden within the human microbiome, as antibiotics and pathogens in wastewater can track with clinically relevant parameters during perturbations to the community. In this study, we monitored culturable and resistant wastewater bacteria and cross-resistance to clinically relevant antibiotics to gauge the impact of each antimicrobial and identify factors influencing cross-resistance profiles. Bacteria resistant to TCS and BC were isolated from wastewater influent over 21 months, and cross-resistance, taxonomy, and monthly changes were characterized under both antimicrobial selection regimes. Cross-resistance profiles from each antimicrobial differed within and between taxa. BC-isolated bacteria had a significantly higher prevalence of resistance to "last-resort antibiotic" colistin, while isolates resistant to TCS exhibited higher rates of multidrug resistance. Prevalence of culturable TCS-resistant bacteria decreased over time following Food and Drug Administration (FDA) TCS bans. Cross-resistance patterns varied according to sampling date, including among the most clinically important antibiotics. Correlations between strain-specific resistance profiles were largely influenced by taxonomy, with some variations associated with sampling date. The results reveal that time, taxonomy, and selection by TCS and BC impact features of cross-resistance patterns among diverse wastewater microorganisms, which could reflect the variety of factors influencing resistance patterns relevant to a community microbiome.

Pellagra secondary to selective eating in a child with autism.

Once a significant cause of morbidity and mortality, health care providers rarely see primary pellagra in developed countries where fortification of foods with niacin is commonplace and niacin-rich foods are generally widely available. We report a ten-year-old boy with autism spectrum disorder who presented with photosensitive dermatitis which resolved after vitamin supplementation and dietary changes. In this child, the pellagra developed as the result of a long-term pattern of selective eating. Restricted diets, even to the point of nutrient deficiencies, are well-documented among children with autism spectrum disorders (ASD).

Calculation of the impulse response and phase noise of a high-current photodetector using the drift-diffusion equations.

We describe a procedure to calculate the impulse response and phase noise of high-current photodetectors using the drift-diffusion equations while avoiding computationally expensive Monte Carlo simulations. We apply this procedure to a modified uni-traveling-carrier (MUTC) photodetector. In our approach, we first use the full drift-diffusion equations to calculate the steady-state photodetector parameters. We then perturb the generation rate as a function of time to calculate the impulse response. We next calculate the fundamental shot noise limit and cut-off frequency of the device. We find the contributions of the electron, hole, and displacement currents. We calculate the phase noise of an MUTC photodetector. We find good agreement with experimental and Monte Carlo simulation results. We show that phase noise is minimized by having an impulse response with a tail that is as small as possible. Since, our approach is much faster computationally than Monte Carlo simulations, we are able to carry out a broad parameter study to optimize the device performance. We propose a new optimized structure with less phase noise and reduced nonlinearity.

Is vitamin C enough? A case report of scurvy in a five-year-old girl and review of the literature.

BACKGROUND: Numerous cases of scurvy secondary to diet limitations have been reported in the literature with most being boys with special needs. To date, the focus of the literature describing vitamin C deficiency has been the medical sequelae of the deficiency. There has been little attention given underlying diet limitations causing the vitamin C deficiency. CASE PRESENTATION: A five-year-old female with typical development initially presented with rash, then later for pain in both lower extremities. After evaluation revealed vitamin C deficiency, she was admitted into an intensive day treatment feeding program. A feeding assessment found she had life-long problems with eating and had a diet that never exceeded ten foods. Across the course of treatment, she learned to eat 29 new foods. At six-month follow-up her body mass index had increased from the 1st to the 61st percentile. At one-year follow-up her body mass index was at the 85th percentile. All sequalae of her deficiency resolved. CONCLUSIONS: This case is unusual as most reported studies describe males with special needs. The severity of her eating issues suggest providers may consider referral to allied health professionals to address diet limitations for both children identified with nutrient deficiencies as well as children whose selective eating places them at risk for nutritional deficiencies or problems with growth. The child we described was anemic, like 42% of children described in the case literature on scurvy and like 32% of the children in this literature, our patient was underweight. In the literature, comorbid nutrient deficiencies were reported in 22% of the scurvy case studies. We suggest vitamin C supplementation is a necessary component for addressing vitamin C deficiency, but insufficient for addressing the diet limitations causing the nutrient deficiency.

Correction to: Is vitamin C enough? A case report of scurvy in a five-year-old girl and review of the literature.

Following publication of the original article [1], the authors reported that an out-of-date version of Figure 1 had been incorporated in the published article.

Sensory Eating Problems Scale (SEPS) for children: Psychometrics and associations with mealtime problems behaviors.

The present study developed the 22-item Sensory Eating Problems Scale (SEPS) to measure sensory aspects for children surrounding eating, documented psychometrics of SEPS subscales, and examined their association with mealtime behavior problems. Study participants were 449 caretakers of children referred to feeding clinics, including children in three special needs status groups: autism spectrum disorder (ASD), other special needs, and no special needs. Caretakers completed surveys to report children's demographics, four measures of children's mealtime behavior problems, and five-point ratings for how often children showed various sensory feeding reactions. Exploratory factor analysis of the sensory feeding items identified six SEPS subscales with acceptable goodness-of-fit, internal reliability, and test-retest reliability: Food Touch Aversion, Single Food Focus, Gagging, Temperature Sensitivity, Expulsion, and Overstuffing. ANCOVAs revealed that child demographics most associated with higher SEPS subscale scores were younger age and special needs. Multiple regression analyses found that children's mealtime behavior problems were most often associated with SEPS subscales of Food Touch Aversion, Single Food Focus, Expulsion, and Overstuffing, with the set of six subscales explaining 18-44% of variance in mealtime behavior problems. Suggestions for how clinicians and researchers may find the SEPS useful for assessment and intervention are provided.

Oral Binge-Like Ethanol Pre-Exposure During Juvenile/Adolescent Period Attenuates Ethanol-Induced Conditioned Place Aversion in Rats.

AIMS: To determine if oral ethanol self-administration produces a conditioned place preference (CPP) and to determine if ethanol pre-exposure conditions during the juvenile/adolescent period alter the conditioned effects of ethanol and subsequent ethanol self-administration. SHORT SUMMARY: Modified conditioned place preference paradigm allowed rats to orally self-administer ethanol followed by short duration exposure to conditioning chambers. Ethanol produced a conditioned place aversion even though rats self-administered ethanol following the final conditioning test. Juvenile/adolescent pre-exposure to ethanol decreased the place aversion but did not produce place preference. METHODS: Juvenile/adolescent rats consumed sweetened 5% ethanol in the home-cage either during continuous access or intermittent access with water restriction that promoted binge-like consumption. A control group had water access during the 4-week period. Adult rats were conditioned using a modified CPP paradigm wherein rats were water-restricted overnight before being placed in operant chambers to respond for 5% ethanol for 7 min. Following the operant session, rats were placed in the conditioning chamber for 8 min. After the conditioning post-test, rats self-administered ethanol during daily operant sessions. RESULTS: Ethanol produced a conditioned place aversion in water access rats and the continuous access rats. Binge-like ethanol consumption induced by intermittent access with water restriction abolished the place aversion, but did not allow place preference to develop. After conditioning, continuous access rats self-administered ethanol above ~0.6 g/kg which was similar to rats with binge-like experience via intermittent access. CONCLUSIONS: Results suggest that oral ethanol self-administration elicits aversive properties in this model even though ethanol continues to maintain self-administration. Pre-exposure to ethanol during the juvenile/adolescent period may produce tolerance to ethanol's aversive properties only when consumed in a binge-like manner with water restriction. More exploration is needed to understand how behavioral history can influence sensitivity to ethanol's rewarding and aversive properties and subsequent ethanol consumption or self-administration.

Frequency dependent harmonic powers in a modified uni-traveling carrier photodetector.

We use a drift-diffusion model to study frequency dependent harmonic powers in a modified uni-traveling carrier (MUTC) phododetector. The model includes external loading, incomplete ionization, the Franz-Keldysh effect, and history-dependent impact ionization. In three-tone measurements, the bias voltage at which a null occurs (bias null) in the second-order intermodulation distortion (IMD2) is different for the sum frequency and difference frequency. We obtained agreement with the experimental results. The bias null that appears in the IMD2 is due to the Franz-Keldysh effect. The bias voltage at which the bias null is located depends on the electric field in the intrinsic region, and the difference in the location of the bias null for the sum frequency and difference frequency is due to the displacement current in the intrinsic region. When the frequency is large, the displacement current is large and has a large effect on the harmonic powers. We also found that the bias null depends on the recombination rate in the p-absorption region because the electric field decreases in the intrinsic region when the recombination rate in the p-region decreases.

Impact of the Coulomb interaction on the Franz-Keldysh effect in high-current photodetectors.

The Franz-Keldysh effect has been recognized as the largest contributor to oscillations in the responsivity of high-current photodetectors as a function of the applied bias or the incident light wavelength and to device nonlinearity. Prior work only considered the effect of the electric field without considering the Coulomb interaction. We show that it is not possible to obtain agreement with experiments at all optical wavelengths without including this effect in the effective mass equation. We find the maxima and minima in the absorption of the applied electric field shift when the Coulomb interaction is included. We then use the calculated absorption with the drift-diffusion equations to calculate the responsivity in a partially depleted absorber (PDA) photodetector, and we obtain excellent agreement with experiments at all biases and optical wavelengths.

The Parent Mealtime Action Scale revised (PMAS-R): Psychometric characteristics and associations with variables of clinical interest.

The purpose of the present study was to provide a revised and more psychometrically-examined version of the Parent Mealtime Action Scale (PMAS-R), then to examine how well the PMAS-R subscales explained variance for four variables relevant in clinical settings. Study participants included 238 parents of children referred to a hospital-based feeding program (72.3% male children; mean age = 72.2 months; 80 with autism spectrum disorder, 77 with other special needs, 81 with no special needs). Parents completed questionnaires to report child demographics and diet habits. Parents also used a five-point rating instead of the original three-point rating to report their usage of the 31 PMAS feeding practices. Using five-point ratings, the nine subscales of the PMAS-R demonstrated improved internal reliability and test-retest reliability compared to those published for the original PMAS. ANCOVA indicated that special needs status was the child demographic variable most associated with PMAS-R feeding practices. Hierarchical multiple regression revealed that after controlling for child demographics, the nine PMAS-R subscales explained 26-49% of the variance for four variables of clinical interest (fruit and vegetable consumption, snack consumption, total food variety, and weight status). These variables of clinical interest were most often associated with "permissive" feeding practices including low Daily Fruit and Vegetable (FV) Availability, rarely using Insistence on Eating during meals, often using Many Food Choices, and often using Child-Selected Meals. The present study provides a more psychometrically-sound measure of child feeding practices, documents the association between "permissive feeding" and variables of clinical interest, and identifies specific parent practices included in "permissive feeding".

Spermidine and Ca(2+), but not Na(+), can permeate NMDA receptors consisting of GluN1 and GluN2A or GluN2B in the presence of Mg(2+).

N-Methyl-D-aspartate receptors (NMDA receptors) are known to be permeable to Na(+) and Ca(2+) ions. In this study, we tested whether polyamines (putrescine, spermidine, spermine), organic cations found in cells, can permeate NMDA receptors expressed in Xenopus laevis oocytes and HEK293 cells. It was found that polyamines, especially spermidine, can permeate NMDA channels expressed from GluN1/GluN2A or GluN1/GluN2B activated by glycine and glutamate. Furthermore, spermidine and Ca(2+) influx through NMDA receptors was observed in the presence of Mg(2+), although Na(+) influx was strongly inhibited by Mg(2+). The Km values for spermidine influx through GluN1/GluN2A and GluN1/GluN2B were 2.2 mM and 2.7 mM, respectively in the presence of isotonic extracellular ion solutions. Spermidine uptake by NMDA receptors was dependent on the presence of glycine and glutamate, and inhibited by Ca(2+) and by memantine, an NMDA receptor channel blocker. The Km values for Ca(2+) influx through GluN1/GluN2A and GluN1/GluN2B were 4.6 mM and 3.3 mM, respectively, under the same ionic conditions. The results indicate that spermidine and Ca(2+), but not Na(+), can permeate NMDA receptors in the presence of Mg(2+). Spermidine, if released locally from presynaptic terminals (where its concentration is high in synaptosomes and synaptic vesicles) could permeate NMDA receptors and play a role in synaptic plasticity mediated by NMDA receptors together with Ca(2+).

Simulation of a partially depleted absorber (PDA) photodetector.

We use a 2D drift-diffusion model to study the nonlinear response of a partially depleted absorber (PDA) phododetector. The model includes external loading, incomplete ionization, the Franz-Keldysh effect, and history-dependent impact ionization. It also takes into account heat flow in the device. With all these effects included, we obtain excellent agreement with experiments for the responsivity and for the harmonic power at different modulation frequencies. The role of these different physical effects is elucidated, and we find that both the Franz-Keldysh effect and the load resistance play a key role in generating higher harmonic power at larger reverse biases. Increasing the size of the p-region absorption layers reduces the impact of the Franz-Keldysh effect. Decreasing the effective load resistance also decreases the higher harmonic powers. We also show that the model can suggest design changes that will improve device performance.

Analysis of magnitude and relative phase of photodiode IMD2 using amplitude matched MZM-distortion cancellation technique.

We present a detailed look at using Mach-Zehnder modulator generated distortion for identifying the magnitude and relative sign of photodiode generated second order intermodulation distortion (IMD2). Previous discussions introduced the concept for characterizing a test device. Analysis is expanded to IMD2 as a function of voltage, photocurrent and frequency.