Feeding Sessions Research Articles

Effects of an activity-based anorexia procedure on within-session changes in nose-poke responding

This study tested the effects of an activity-based anorexia (ABA) procedure on within-session changes in responding. In the ABA group (N=8), rats were given a 60-min feeding session and allowed to run in a running wheel for the remainder of each day. During the daily 60-min feeding session, each nose-poke response was reinforced by a food pellet. In the control group (N=8), rats experienced the same procedure except that the wheel was locked and thus rats could not run. The experiment lasted for 6 days. Rats in the ABA group consumed less and lost more body weight than those in the control group. Within-session decreases in nose-poke responding were steeper for ABA than control rats. In addition, response rates were well described as linear functions of the cumulative number of reinforcers in both groups (r2s>.96). The regression lines for the ABA group had steeper slopes and smaller x-axis intercepts than those for the control group. However, the y-axis intercepts of the regression lines were similar for the two groups. These effects were different from the effects of taste-aversion learning induced by post-session wheel running (Aoyama, 2007), suggesting a different mechanism in each preparation.

An examination of the effects of subthalamic nucleus inhibition or μ-opioid receptor stimulation on food-directed motivation in the non-deprived rat

The subthalamic nucleus (STN) serves important functions in regulating movement, cognition, and motivation and is connected with cortical and basal ganglia circuits that process reward and reinforcement. In order to further examine the role of the STN on motivation toward food in non-deprived rats, these experiments studied the effects of pharmacological inhibition or μ-opioid receptor stimulation of the STN on the 2-h intake of a sweetened fat diet, the amount of work exerted to earn sucrose on a progressive ratio 2 (PR-2) schedule of reinforcement, and performance on a differential reinforcement of low-rate responding (DRL) schedule for sucrose reward. Separate behavioral groups (N=6–9) were tested following bilateral inhibition of the STN with the GABAA receptor agonist muscimol (at 0–5ng/0.5μl/side) or following μ-opioid receptor stimulation with the agonist D-Ala2, N-MePhe4, Gly-ol-enkephalin (DAMGO; at 0, 0.025 or 0.25μg/0.5μl/side). Although STN inhibition increased ambulatory behavior during 2-h feeding sessions, it did not significantly alter intake of the sweetened fat diet. STN inhibition also did not affect the breakpoint for sucrose pellets during a 1-h PR-2 reinforcement schedule or impact the number of reinforcers earned on a 1-h DRL-20s reinforcement schedule in non-deprived rats. In contrast, STN μ-opioid receptor stimulation significantly increased feeding on the palatable diet and reduced the reinforcers earned on a DRL-20 schedule, although DAMGO microinfusions had no effect on PR-2 performance. These data suggest that STN inhibition does not enhance incentive motivation for food in the absence of food restriction and that STN μ-opioid receptors play an important and unique role in motivational processes.

Impact of nonnutritive oral motor stimulation and infant massage therapy on oral feeding skills of preterm infants

We have shown that the provision of a nonnutritive oral motor therapy (NNOMT) or infant massage therapy (iMT) provided singly and in combination vs. no intervention shortens the number of days from start to independent oral feeding in very low birth weight infants. This study hypothesizes that infants who benefited from NNOMT and/or iMT will demonstrate enhanced maturation of their oral feeding skills (OFS) when compared to control counterparts. OFS levels were monitored using a recently developed scale that takes into account their nutritive sucking skills and endurance at time of assessment. It is a simple method that requires only the additional reading of the volume taken 5 minutes into the start of a feeding and information routinely recorded in patients' medical chart. Four OFS levels were identified, characterized by infant's proficiency (% volume taken during the first 5 min/volume prescribed) and rate of transfer monitored over the entire feeding session (ml/min); OFS level 1 being the most immature and 4 the most mature. In parallel with the benefits provided by NNOMT and/or iMT, we demonstrate the direct positive impact these interventions have on accelerating the maturation of infants' oral feeding skills.

Induction of low-nutritious food intake by subsequent nutrient supplementation in sheep (Ovis aries)

Acceptance of and preference for a particular food depends not only on its intrinsic (e.g. nutritional) properties but also on expected or recent food experiences. An instance of this type of phenomenon has been called induction effect, which consists of an increased intake of a type of food when it precedes a hedonically preferred food in a sequence familiar to the animal, relative to controls that have access only to the less-preferred food. The purpose of our study was to assess intake induction of a low-nutritious food when followed by different high-nutritious supplements in sheep (Ovis aries). In this experiment, we ran a supplemented phase where animals fed oat hay (a low-nutritious food) in the first part of the daily feeding sessions followed by a supplement with either a high (soya bean meal; group GS) or a low (ground corn; group GC) protein–energy ratio in the second part ate more oat hay than controls that were fed oat hay in both parts of sessions (group GH). In addition, supplemented animals presented a stronger preference for oat hay over alfalfa hay than controls in a subsequent choice. When all animals received no food in the second part of the sessions (Non-supplemented phase), intake of oat hay converged to the control's intake level in all the groups, suggesting that the presence of supplements after access to oat hay was responsible for intake induction. Lastly, we repeated the supplemented phase with a different control group where animals received oat hay in the first part of the sessions and no food in the second part (group NF), thus equalizing groups in terms of the time of access to oat hay in a session. Groups GS and GC still developed higher intake of oat hay than group NF. In both supplemented phases of the experiment, we estimated animals’ daily metabolizable energy (ME) and crude protein (CP) intake. CP intake was higher in group GS than in groups GC, GH and NF, but there was no difference between group GC and the controls. In turn, groups did not differ in ME intake in the First supplemented phase, and only group GS presented higher ME intake than the rest of the groups in the Second supplemented phase. Therefore, a nutritional account of the present induction effect seems insufficient. We propose that a learned association between oat hay and the post-ingestive feedback from the subsequent high-nutritious supplements underlay sheep's intake induction and increased preference for oat hay.

Feeding, stooling and sleeping patterns in infants with colic - a randomized controlled trial of minimal acupuncture

BackgroundThe aim was to describe the feeding- and stooling patterns of infants with colic and evaluate the influence of minimal acupuncture.MethodsA prospective, randomized, controlled, blind clinical study was conducted at a private acupuncture clinic in Sweden. 90 otherwise healthy 2-8 weeks old infants, born after gestational week 36, fulfilling the criteria for infantile colic and not medicated with dicyclomine, were included. 81 infants went through a structured program consisting of six visits to the clinic, twice weekly. Infants randomized to receive acupuncture were given minimal, standardized acupuncture for two seconds in LI4. Frequency and size of stooling, as well as duration of, and intervals between, feeding sessions were reported by parents in a diary. Parental assessment of sleep and comments on stooling and side effects were collected in a questionnaire.ResultsAt baseline when the mean age was five weeks, infants in both groups were fed a median of eight times/day, 148 min/day, with considerable variations. No differences were found between groups in the frequency and duration of feeding during the intervention weeks. Furthermore there were no significant differences between the groups regarding the frequency of stooling, neither at baseline, at which point the infants of both groups had bowel movements 4.2 times/day, nor during the intervention weeks. There was an expected decrease in frequency of stooling in both groups, reaching 2.1 (p = 0,001) in the acupuncture group and 3.1 (p < 0,001) in the control group. The groups differed regarding large bowel movements which decreased linearly in the control group (p = 0,011) but not in the acupuncture group (p = 0,787). More parents in the acupuncture group than in the control group (28% and 15% respectively, p = 0.006) experienced the infant's sleep to be "better" or "much better." No other significant differences were found. However, parents described a normalized stooling and experienced an improvement in colic in their infants more frequently in the acupuncture group than in the control group.ConclusionsInfants with colic in the present study had a higher frequency of stooling than reported internationally in healthy infants. Minimal acupuncture had no major effect on feeding, stooling and sleep, although a minor effect of minimal acupuncture on stooling and sleep cannot be ruled out.Trial registrationClinicalTrials.govID NCT00860301

Rapid post-oral stimulation of intake and flavor conditioning by glucose and fat in the mouse

Although widely assumed to have only satiating actions, nutrients in the gut can also condition increases in intake in some cases. Here we studied the time course of post-oral nutrient stimulation of ingestion in food-restricted C57BL/6J mice. In experiment 1, mice adapted to drink a 0.8% sucralose solution 1 h/day, rapidly increased their rate of licking (within 4-6 min) when first tested with an 8% glucose solution and even more so in tests 2 and 3. Other mice decreased their licking rate when switched from sucralose to 8% fructose, a sugar that is sweet like glucose but lacks positive post-oral effects in mice. The glucose-stimulated drinking is due to the sugar's post-oral rather than taste properties, because sucralose is highly preferred to glucose and fructose in brief choice tests. A second experiment showed that the glucose-stimulated ingestion is associated with a conditioned flavor preference in both intact and capsaicin-treated mice. This indicates that the post-oral stimulatory action of glucose is not mediated by capsaicin-sensitive visceral afferents. In experiment 3, mice consumed flavored saccharin solutions as they self-infused water or glucose via an intragastric (IG) catheter. The glucose self-infusion stimulated ingestion within 13-15 min in test 1 and produced a conditioned increase in licking that was apparent in the initial minute of tests 2 and 3. Experiment 4 revealed that IG self-infusions of a fat emulsion also resulted in post-oral stimulation of licking in test 1 and conditioned increases in tests 2 and 3. These findings indicate that glucose and fat can generate stimulatory post-oral signals early in a feeding session that increase ongoing ingestion and condition increases in flavor acceptance and preference revealed in subsequent feeding sessions. The test procedures developed here can be used to investigate the peripheral and central processes involved in stimulation of intake by post-oral nutrients.

Calcium, dairy products, and energy balance in overweight adolescents: a controlled trial

Dairy product and calcium consumption have been associated with modifying body fat and body weight in children and adults. In overweight adolescent boys and girls, we aimed to determine the effect of the doubling of habitual calcium intake to the recommended intake from dairy or calcium carbonate on energy balance and purported mechanisms including fecal fat excretion, macronutrient use, and parathyroid hormone suppression. Twenty-five girls with a mean (±SD) BMI (in kg/m(2)) of 33 ± 5 and 17 boys with a BMI of 28 ± 5, aged 12-15 y, participated in two 3-wk controlled feeding sessions that used a crossover design in random order as a summer research camp. In one session, 756 mg Ca/d was consumed; in the other session, an additional 650 mg Ca/d was provided as dairy or calcium carbonate supplements that were matched to the control in macronutrient content. Total energy and macronutrient intakes were controlled and were the same for the 2 sessions for each subject. Primary outcome measures were energy balance, fecal fat excretion, lipid oxidation, and postprandial energy expenditure. There were no effects of quantity or source of calcium on energy or fat balance, despite calcium-induced increases (P <0.01) in postprandial serum parathyroid hormone suppression. These data lend little evidence to support the proposed mechanisms for the relation between an increase in calcium intake from calcium carbonate or dairy and weight loss or weight maintenance in children. This trial was registered at clinicaltrials.gov as NCT00592137.

Behavioral alterations in GH transgenic common carp may explain enhanced competitive feeding ability

The aim of the present study was to clarify the role of GH transgenesis and its production in social interactions in juvenile common carp Cyprinus carpio. With food pellets provided sequentially, the serum GH levels and behavioral effects were measured in 14 pairs of size-matched ‘all-fish’ GH-transgenic and non-transgenic common carp. In six consecutive observations during 3 days, transgenic fish had a higher movement level as well as a higher social status, being 2.69 times as aggressive, two minutes before and after the 10-min feeding session compared to non-transgenic fish. Transgenic fish also were more than 1.74 times as likely to consume each pellet. During the 8-day experiment, transgenic fish had 4.09 times higher specific growth rate in body weight as well as 6.36 times higher serum GH level than the non-transgenic fish. These results show that GH transgenesis promotes over-expression of GH and alters behaviors in juvenile common carp, thereby increasing their ability to compete and gain food resources, presumably to meet a higher intrinsic growth rate, which gives direct evidence for the GH-induced elevation in feeding competitive ability of GH-transgenic common carp. Understanding these relationships would not only help evaluating potential ecological effects of the escaped/released transgenic fishes, but also help using potential aquaculture of this growth-enhanced strain.

A Novel Approach to Assess Oral Feeding Skills of Preterm Infants

Background: There is no well-defined means to identify the level of oral feeding skills (OFS) in preterm infants. Objective: To determine whether OFS as reflected by the combination of proficiency (PRO, %ml taken during the first 5 min/ml prescribed) and rate of milk transfer (RT, ml/min) correlates with gestational age (GA), oral feeding performance (OT, %ml taken during a feeding/ml prescribed) and days from start to independent oral feeding (SOF-IOF). Our working premises are that PRO is reflective of infants’ actual feeding skills when fatigue is minimal and RT, monitored over an entire feeding session, reflects their overall skills when fatigue comes into play. Methods: Infants (26–36 weeks GA) with prematurity as their principal diagnosis were recruited and monitored at their first oral feeding. GA was divided into 3 strata, 26–29, 30–33, and 34–36 weeks GA. OFS was divided into 4 levels delineated by PRO (≧ or <30%) and RT (≧ or <1.5 ml/min). ANOVA with post-hoc Bonferroni and multiple regression analyses were used. Results: OFS levels were correlated with GA. OT, PRO, and days from SOF-IOF were associated with OFS and GA, whereas RT was only correlated with OFS levels. Conclusions: OFS is a novel objective indicator of infants’ feeding ability that takes into account infants’ skills and endurance. As a clinical tool, it can help caretakers monitor infants’ skills as they transition to oral feeding and identify oral feeding issues arising from immature skills and/or poor endurance.

Influence of defensible and indefensible pattern of food delivery upon the development of feeding anticipatory activity (FAA) and growth performance in rainbow trout (Oncorhynchus mykiss)

AbstractUsing two methods of food delivery, defensible (D) and indefensible (ID), the effect of restricted feeding (RF) on the development of feeding anticipatory activity (FAA) and growth performance of rainbow trout (Oncorhynchus mykiss) was investigated. Six glass aquaria (120 × 30 × 80 cm), divided equally into 3 sections of morning, afternoon and evening of location of food delivery each with eight fish were selected for D and ID methods. The fish were subjected to a time-RF schedule for 70 days. Food delivery was restricted to three feeding periods; one hour per feeding session: morning (0800-0900 h), afternoon (1300-1400 h) and evening (1800-1900 h). Food was withheld on days 28, 42, 56 and 70 (test days) to assess FAA by the fish and fish growth parameters were determined at the end of the experiment. The present results clearly indicate that only using an indefensible (ID) pattern of food delivery, rainbow trout can simultaneously anticipate three daily meals and synchronise their feeding activity before the period of food availability and that the best FCR and SGR were achieved when an ID pattern of food delivery was offered. The lack of development of FAA for fish in the D method could be due to development of dominant hierarchies. This led to reduction of most growth parameters in the D method compared to the ID one.

Contrasting effects of systemic and central sibutramine administration on the intake of a palatable diet in the rat

Sibutramine hydrochloride monohydrate is the only centrally active weight-modifying agent currently approved by the FDA for long-term use in the treatment of obesity. Systemic sibutramine treatment has been shown to reduce food intake in humans and rodent models in a manner that is consistent with the enhancement of satiety mechanisms. Although it is generally assumed that the hypophagic effects of the drug are mediated by actions within the brain, the locus or loci of these effects remains unclear. These experiments compared the effects of systemic and intracranial injections of sibutramine on the intake of a palatable diet in non-deprived animals. Consistent with prior reports, systemic injections of sibutramine hydrochloride (at 0, 0.5, 1.0, or 3.0 mg/kg sibutramine i.p.) dose-dependently reduced feeding on a high fat/high sucrose diet across a 2-h feeding session, but did not alter water intake or locomotor activity. In contrast, bilateral injections of sibutramine (at 0.0, 2.0, 4.0 and 10.0 μg/0.5 μl/side) into either the paraventricular nucleus of the hypothalamus (PVN) or the medial nucleus accumbens shell (ACb) significantly and dose-dependently increased food intake of the sweetened fat diet. ACb treatment also modestly inhibited locomotor behavior; intracranial injections had no effect on water consumption. These experiments are the first to suggest that sibutramine treatment may have distinct actions upon separate neural circuits that modulate food intake behavior in the rat.

Neonatal sucking behavior: Comparison of perioral movement during breast‐feeding and bottle feeding

The aim of the present study was to compare orofacial motion and mouth angle during breast-feeding and bottle feeding in normal infants. Thirteen normal infants were enrolled in the study, and feeding sessions were recorded using a digital video camera at 4 or 5 days following birth. The analysis was successfully performed for 12 infants during both breast-feeding and bottle feeding. Markers were placed at the lateral angle of the eye, the tip of the jaw, and the throat region. Jaw and throat region movements were calculated using the direct linear transformation method. The angle of the mouth was also measured. Throat region movement was significantly larger than jaw movement in both breast-feeding (eye-throat region changes: 1.51 +/- 0.37 mm, eye-jaw changes: 0.91 +/- 0.31 mm, P < 0.001) and bottle feeding (eye-throat region changes: 2.91 +/- 0.46 mm, eye-jaw changes: 1.77 +/- 0.33 mm, P < 0.001). Jaw and throat region movements were significantly smaller during breast-feeding than those during bottle feeding (P < 0.001). The angle of the mouth during breast-feeding is larger than that during bottle feeding (P < 0.001). There was a negative correlation between the angle of the mouth and jaw movement. Jaw and throat region movements during bottle feeding differ from those during breast-feeding. This partly results from the difference in the angle of the mouth during feeding.

Feeding on one side or both sides in a breast‐feeding session

The aim of the present study was to examine the effects of breast-feeding method (on only one or on two sides in a single feeding session) on growth, sleep duration and sucking period, and stool frequency. Exclusively breast-fed healthy infants, aged 1-6 months, were included in the study during child health follow-up visits. Mothers were given a questionnaire on sleep duration, sucking periods, and stool frequencies of their infants. The height-for-age and weight-for-age z scores were significantly higher in infants breast-fed from one side during a single session than from both sides (P= 0.002, P < 0.001; respectively). Infants sucking on only one breast in a breast-feeding session defecated significantly less at night (P= 0.005), their maximum sucking periods at night were shorter (P= 0.049). Breast-feeding at one side only during a single breast-feeding session increases growth, decreases stool frequency and the maximum sucking period at night and does not influence the overall sleep pattern.

Parental and chick responses of Laughing Gulls (Leucophaeus atricilla) to increase of flight costs and brood size

One main line of thought in life history theory is that investment in offspring must be balanced to minimize negative impacts on adult survival and future breeding. Seabirds have been regarded as fixed investors, although they exhibit a whole gradient of life history traits. We studied the consequences of brood size (one and three chicks) and of increased flight costs to one mate of a pair (3- and 5-cm trimming of the edge of the primary feathers) on parental response and on survival and body condition of chicks of Laughing Gulls (Leucophaeus atricilla). Parent gulls modified their nest attendance when their mate was handicapped, in a pattern dependent on the sex of the latter. Trimming of males affected chicks more severely than that of females. On its part, brood size affected amount of feeding sessions. Both chick body condition and survival were negatively affected by larger broods and by increased flight costs of one of their parents, especially when it was the male. Overall, parental inversion exhibited adjustments depending on the requirements of the brood and the fact that males compensated better the increased flying costs of their mates than vice versa. Despite a certain capacity by the males to compensate for the increased flight costs of the females, compensation was insufficient, and much less so in females, especially in larger broods, affecting chicks’ body condition and survival.

High levels of grass pollen inside European dairy farms: a role for the allergy‐protective effects of environment?

There is evidence of an allergy protective effect in children raised on farm. It has been assumed that microbial exposure may confer this protection. However in farm, little attention has been given to the pollen level and to concomitant microbiological exposure, and indoor pollen concentrations have never been precisely quantified. The kinetics of pollen in dairy farms have been studied in a pilot study (n = 9), and exposure in a sub-sample of the ongoing European birth cohort PASTURE (n = 106). Measurements of viable microorganisms and pollen were performed in air samples. To identify factors that modulate the pollen concentration multivariate regression analyses were run. Indoor pollen (95% of Poaceae fragments and grains) were significantly higher in winter than in summer (P = 0.001) and ranged between 858 to 11 265 counts/m(3) during feeding in winter, thus exceeding typical outdoor levels during the pollen season. Geometric mean in French farms was significantly higher than in German and Swiss farms (7 534, 992 and 1 079 count/m(3), respectively). The presence of a ventilation system and loose housing systems significantly reduced indoor pollen levels. This pollen concentration rise after feeding was accompanied by an increase in fungal and actinomycetal levels, whereas the concentration of bacteria was not associated with feeding. Farmers and their children who attend cowsheds during the feeding sessions are exposed perennially to high pollen concentrations. It might be speculated that the combined permanent exposure to microbes from livestock and grass pollen may initiate tolerance in children living on a farm.

Effect of early skin-to-skin contact on mother–preterm infant interaction through 18 months: Randomized controlled trial

Background Preterm birth often negatively influences mother–infant interaction. Skin-to-skin contact postbirth has positive effects on maternal feelings toward their preterm infants and on infant development and family interaction. However, little is known about the long-term effects of skin-to-skin contact on mother–late preterm infant interaction when skin-to-skin contact was experienced early postbirth and intermittently throughout the next five days. Objective The purpose of this report was to examine the effect of skin-to-skin contact on mother–late preterm infant interaction through 18 months. Design Randomized controlled trial with follow-up. Setting Two hospitals in the United States of America. Participants 100 mothers and their late preterm infants, 32 to <37 weeks’ gestation, were recruited. Mother–preterm infant interactions were assessed in 69, 70, and 76 dyads at 6, 12, and 18 months. Methods Mothers and their preterm infants were videotaped during a feeding session at 6 and 12 months, and a teaching session at 6, 12, and 18 months. Their interactions were then scored using the Nursing Child Assessment Satellite Feeding Scale and Teaching Scale. Results Skin-to-skin contact and control dyads had comparable feeding scores at 6 and 12 months. Skin-to-skin contact infants had lower infant teaching scores at six months, a difference that disappeared thereafter. Conclusions These inconclusive results call for additional studies with larger doses of skin-to-skin contact, larger sample sizes, and other outcome measures of mother–late preterm infant interactions. Such measures include the Parent–Child Early Relational Assessment and behavioral coding during play.

The effect of moderate exercise on growth and aggression depending on social rank in groups of Arctic charr ( Salvelinus alpinus L.)

Several studies have shown that prolonged moderate exercise improve conditions for the farming of salmonids, by reducing aggressive interactions and resulting in enhanced growth and reduced size variation. The present study focuses on the effect of forced moderate exercise on growth and aggression depending on the individual social rank, compared to non-exercised controls in groups of Arctic charr ( Salvelinus alpinus L.). Social screening was done prior to the trial in each of 24 groups with five charr, where every fish was ranked into one of five social ranks by successive removal of individuals displaying a dominant or aggressive behaviour. Four ranking groups (= 20 fish) were then merged into one experimental group (= 6 groups), each with four tagged individuals of ranks 1–5. After 62 days with or without forced exercise, no significant difference in mean Daily Growth Coefficient (DGC) in the exercised (DGC = 1.25 ± 0.46) and non-exercised (DGC = 1.39 ± 0.47) groups were found. A significant relationship between rank and size at the start remained significant in the non-exercised groups but became insignificant in the exercised groups. It was the highest ranked fish that gained by not being forced to exercise. They had a significantly higher weight gain than the highest ranked fish in the exercised groups and all lower ranked fish independent of treatment. The observed aggression was significantly higher in the non-exercised groups and higher in between than during feeding sessions.

Variability in eating behavior throughout the weaning period

During the introduction of solid food (usually indicated as the weaning period), infant and caregiver have to adjust their feeding interactions to a completely changed feeding context. In this paper, we argue that these adjustments can be seen as a complex process in which many factors are involved. As a result of these complex interactions, eating behavior can be highly variable between infants and from feed to feed. The aim of this study is to describe these patterns of variability across this critical transition in feeding. The study is based on naturalistic observations of 20 infant–caregiver dyads (15 repeated observations of each dyad), from the first attempt to spoon-feed till 12 weeks after the introduction of solid food. The results show that there is considerable short-term variability in eating behavior (food intake, meal duration, feeding efficiency, and food refusal), especially immediately after the introduction of solid food. The largest intra-individual variability was found in the earliest feeding sessions, which is consistent with the proposition that systems that undergo rapid development are most sensitive to context variables and thus most variable.

Male stable fly (Stomoxys calcitrans) response to CO2changes with age: evidence from wind tunnel experiments and field collections

Male stable flies require at least one or more blood meals to reach sexual maturity and are often caught in CO2-baited traps. We tested the hypothesis that young male stable flies (one to three days, one blood feeding session) would be more responsive to CO2 bait than older male stable flies by monitoring the upwind movement of different-aged male stable flies exposed to CO2 using a wind tunnel. The proportion of males moving upwind toward CO2 decreased with age (days), from 49% for males < or = 3 days old, to 4.5% for males > 3 days old. To further test this, we conducted daily sampling of stable fly populations at a beef farm using a CO2-baited cloth trap. We found that days on which a high proportion of males were caught, females were predominantly from early developmental stages, indicating that proportionately more males were caught from field populations made up of younger cohorts. These results were consistent with the wind tunnel experiment patterns.

Development of a prompting method to promote adolescent mother/infant verbal interactions using bug-in-the-ear-feedback

It has been documented that adolescent mothers are less verbally and emotionally responsive in their interactions with their children compared to adult mothers. These less than optimal adolescent mother/infant interactions have been found to affect the child's healthy growth and development. This small study aimed to identify and characterize the frequency of verbal behaviors exhibited in the infant/adolescent mother dyad during feeding sessions during a baseline phase of a study that employed single subject methodology. An individualized bug-in-the-ear feedback and prompting parent training model was instituted in the intervention phase of the study to improve the frequency and quality of infant-mother interaction. Results of the study clearly revealed low frequency of verbal interaction in the baseline phase. After a structured prompting intervention was instituted there were positive effects in the mother's behaviors which in turn positively impacted infant behavior.