Formulation of Artificial Diets for Mass-Rearing Eldana saccharina Walker (Lepidoptera: Pyralidae) Using the Carcass Milling Technique.

The carcass milling technique (CMT) formulates specific diets from nutrient analyses of species to be reared and their natural host plants. The first of four diets developed used the minimum ingredient specifications (MS) of published diets for Eldana saccharina. The remaining were based on the ideal amino acid composition and profile (IAAP) of its second (IAAP2), third/fourth (IAAP3/4) and fifth/sixth (IAAP5/6) instar larvae. The control was a modified Ostrinia nubilalis diet. Survival to pupae of inoculated E saccharina neonates was high on all CMT formulations (>92% at day 20 and >97% at day 27). Larvae developed fastest on the IAAP3/4 and MS diets (25% and 17% prepupae and pupae on day 20, respectively). Pupal weights were not significantly influenced by CMT diets (0.1121 g male; 0.1864 g female). The control group produced heavier male and female pupae (0.1204 g; 0.2085 g, respectively). Adult emergence was highest from the MS (98%), then the IAAP3/4 (97%) and control (96%) diets. Sex ratio of adults from all diets was close to one. Males from the IAAP5/6 diet mated with significantly more females (six), and females from the MS diet mated with more males (three) than those from remaining formulations. All females produced in excess of 870 eggs, more than 90% were fertile after mating. The pH (4.79); moisture content (81.43%) and water activity (0.92 aw) of the diets were not significantly different, maintaining quality and stability throughout the larval period, ensuring optimal growth and development. The MS diet formulation was the preferred choice to replace the current E. saccharina diet.

The development of an improved artificial diet for the mass rearing of Eldana saccharina Walker (Lepidoptera: Pyralidae).

BACKGROUND: This study determined the nutrient requirements of Eldana saccharina Walker (Lepidoptera: Pyralidae), a serious sugarcane pest in South Africa, to develop a more efficient artificial diet for mass-rearing purposes for sterile moth production. Diets tested consisted of a minimum specification (MS) diet representing a diet formulated according to the minimum specification of a summary of published diets, which yielded satisfactory results; an ideal amino acid profile (IAAP) diet, where amino acid composition was based on the profile of amino acids in the 2nd (IAAP2) and 5th /6th (IAAP5/6) instar larvae; and lastly two diets based on the nutrient composition of the natural diet of the insects, papyrus (PAP) and sugarcane (SC). Six treatments with 50 replications were randomly allotted to 300 25 mL plastic screw-top vials. The diet (15 mL) was dispensed into each vial and inoculated with two freshly hatched larvae. Larvae, pupae, and moths were harvested at 28 days after inoculation. Overall survivability, pupal weight, sex ratio, and rate of development was determined and compared with the diet currently in use at the South African Sugarcane Research Institute (CON). Physical characteristics of the diets such as the pH and the water-holding capacity of the diets were also determined. RESULTS: The natural diets (PAP and SC) were not viable as they did not yield any results. Survivability was significantly higher (78%) for the MS diet whilst IAAP2 and IAAP5/6 yielded the second highest survivability (74%) compared to CON (68%). There were no differences in male pupal weights between all treatment diets, as was the case for female pupae. Within dietary treatments, female pupae were heavier than male pupae for all treatment diets. CON (1.0: 1.6) produced significantly less male than female pupae with MS (1.0: 1.2), IAAP2 (1.0: 1.0) and IAAP5/6 (1.0: 1.1) all producing equal amounts of male and female pupae. The MS diet (16%) yielded fourfold the number of moths after 28 days compared to CON (4%) and IAAP2 (4%) diets. IAAP5/6 yielded no moths after 28 days. The life stages thus developed fastest in the MS diet. The pH of all treatment diets remained stable for the entire duration of the trial. No biological contamination was observed through all diets. Differences in water-holding capacity were observed between most diets with PAP and SC losing the most moisture whilst the MS and IAAP2 diets retained the most moisture. CONCLUSION: The MS diet most closely represented the nutrient requirements of E. saccharina, leading to its faster development on this formulation, which could be readily applied for large-scale production of this lepidopteran pest as an aid in the mass rearing of sterile males as part of the integrated pest management plan. © 2020 Society of Chemical Industry.

Development of reduced cost diets for the mass rearing of false codling moth (Thaumatotibia leucotreta).

BACKGROUND: Four trials were conducted; the first established optimal cooking time for false codling moth diets using a microwave oven while the other three trials aimed at determining nutrient requirements, testing these, and evaluating alternative cheaper raw materials. RESULTS: Microwave preparation for 8 min, using a 1000 W microwave oven was found to be the optimal cooking time for all treatment diets at 200 g kg-1 moisture. The minimum specification (MS) diet yielded more larvae per jar (mean ± standard deviation) (759 ± 29) than the control (CON) (652 ± 32) diet and the ideal amino acid profile (IAAP) diet (596 ± 46). The third trial subsequently utilized diets formulated according to the MS diet nutrient specifications but using novel and cheaper raw materials (D1 and D2). Production characteristics of diets D1 and D2 was compared to that of CON. Diets D1 and D2 yielded more larvae per jar (D1 = 911 ± 40; D2 = 830 ± 40) than that of CON (428 ± 40) with the added advantage that the newly formulated diets were cheaper. CONCLUSION: Reduced cost feeds were formulated, mixed and tested which resulted in substantial saving in the mass rearing of the species for integrated pest management. This method shows potential for diet development of other insect species as well. © 2019 Society of Chemical Industry.

Sleep Duration and Sleep Quality: Associations With Depressive Symptoms Across Adolescence.

This study explored whether short sleep duration and sleep quality mediate the relationship between age and depressive symptoms. For comparison, we also explored whether depressive symptoms mediate the relationship between age and short sleep duration and sleep quality. The sample comprised 741 adolescents (63.5% female, mean age 15.78 years, range 11.92-19.67 years) in grades 7-12 from 11 secondary schools in metropolitan Melbourne, Australia. Students completed the Pittsburgh Sleep Quality Index (PSQI) and Center for Epidemiologic Studies Depression Scale (CES-D). Path analyses suggested that short sleep duration significantly mediated the relationship between age and depressive symptoms. Poor sleep quality also significantly mediated this relationship when sleep quality was defined by subjective judgement, but not sleep disturbance, sleep efficiency, or sleep onset latency. Depressive symptoms significantly mediated the relationship between age and short sleep duration and sleep quality (subjective judgement, sleep disturbance, sleep efficiency, and sleep onset latency). These findings suggest that the population-wide increase in depressive symptoms across adolescence is partially mediated by sleep-related developmental changes. They also highlight the importance of examining specific sleep problems when investigating the relationship between sleep and mood in this age group.

Nocturnal indicators of increased cardiovascular risk in depressed adolescent girls.

Depression is an independent risk factor for cardiovascular disease in adults, and recent literature suggests preclinical signs of cardiovascular risk are also present in depressed adolescents. No study has examined the effect of clinical depression on cardiovascular factors during sleep. This study examined the relationship between clinical depression and nocturnal indicators of cardiovascular risk in depressed adolescent girls from the general community (13-18 years old; 11 clinically depressed, eight healthy control). Continuous beat-to-beat finger arterial blood pressure and heart rate were monitored via Portapres and electrocardiogram, respectively. Cardiovascular data were averaged over each hour for the first 6 h of sleep, as well as in 2-min epochs of stable sleep that were then averaged within sleep stages. Data were also averaged across 2-min epochs of pre-sleep wakefulness and the first 5 min of continuous non-rapid eye movement sleep to investigate the blood pressure dipping response over the sleep-onset period. Compared with controls, depressed adolescents displayed a similar but significantly elevated blood pressure profile across sleep. Depressed adolescents had significantly higher systolic and diastolic blood pressure and mean arterial pressures across the entire night (P < 0.01), as well as during all sleep stages (P < 0.001). Depressed adolescents also had higher blood pressure across the sleep-onset period, but the groups did not differ in the rate of decline across the period. Higher blood pressure during sleep in depressed adolescent females suggests that depression has a significant association with cardiovascular functioning during sleep in adolescent females, which may increase risk for future cardiovascular pathology.

Common drive to the upper airway muscle genioglossus during inspiratory loading.

Common drive is thought to constitute a central mechanism by which the efficiency of a motor neuron pool is increased. This study tested the hypothesis that common drive to the upper airway muscle genioglossus (GG) would increase with increased respiratory drive in response to an inspiratory load. Respiration, GG electromyographic (EMG) activity, single-motor unit activity, and coherence in the 0-5 Hz range between pairs of GG motor units were assessed for the 30 s before an inspiratory load, the first and second 30 s of the load, and the 30 s after the load. Twelve of twenty young, healthy male subjects provided usable data, yielding 77 pairs of motor units: 2 Inspiratory Phasic, 39 Inspiratory Tonic, 15 Expiratory Tonic, and 21 Tonic. Respiratory and GG inspiratory activity significantly increased during the loads and returned to preload levels during the postload periods (all showed significant quadratic functions over load trials, P < 0.05). As hypothesized, common drive increased during the load in inspiratory modulated motor units to a greater extent than in expiratory/tonic motor units (significant load × discharge pattern interaction, P < 0.05). Furthermore, this effect persisted during the postload period. In conclusion, common drive to inspiratory modulated motor units was elevated in response to increased respiratory drive. The postload elevation in common drive was suggestive of a poststimulus activation effect.

Early physiological markers of cardiovascular risk in community based adolescents with a depressive disorder.

BACKGROUND: Depression is recognised as an independent cardiovascular risk factor in adults. Identifying this relationship early on in life is potentially important for the prevention of cardiovascular disease (CVD). This study investigated whether clinical depression is associated with multiple physiological markers of CVD risk in adolescents from the general community. METHODS: Participants aged 12-18 years were recruited from the general community and screened for depressive symptoms. Individuals with high and low depressive symptoms were administered a diagnostic interview. Fifty participants, 25 with a current depressive episode and 25 matched healthy controls, subsequently completed cardiovascular assessments. Variables assessed were automatic brachial and continuous beat-to-beat finger arterial blood pressure, heart rate, vascular functioning by pulse amplitude tonometry following reactive hyperaemia and pulse transit time (PTT) at rest. Blood samples were collected to measure cholesterol, glucose and glycohaemoglobin levels and an index of cumulative risk of traditional cardiovascular risk factors was calculated. RESULTS: Depressed adolescents had a significantly lower reactive hyperaemia index and shorter PTT, suggesting deterioration in vascular integrity and structure. Higher fasting glucose and triglyceride levels were also observed in the depressed group, who also had higher cumulative risk scores indicative of increased engagement in unhealthy behaviours and higher probability of advanced atherosclerotic lesions. LIMITATIONS: The sample size and number of males who completed all cardiovascular measures was small. CONCLUSIONS: Clinically depressed adolescents had poorer vascular functioning and increased CVD risk compared to controls, highlighting the need for early identification and intervention for the prevention of CVD in depressed youth.

Nasal insufflation treatment adherence in obstructive sleep apnea.

BACKGROUND: Nasal insufflation (NI) is a novel treatment method that has been introduced for improving respiration during sleep. NI's warmed and humidified nasal airflow provides ventilatory assistance delivered as a rapidly dispersed pressure head, with minimal side wall pressures, that may affect treatment tolerability. The aim of the current study was to investigate objective and subjective adherence rates for NI therapy in mild to moderate obstructive sleep apnea (OSA). METHODS: Ten patients (three men and seven women; age, 51.3 ± 9.6 years; BMI, 32.2 ± 7.7 kg/m2 [mean ± sd]) with recently diagnosed mild to moderate OSA (10.9 ± 5.8 events/h) were investigated. A crossover design was used to compare adherence to NI and continuous positive airway pressure (CPAP) therapy using a range of objective and subjective measurements. Objective (sleep efficiency (%) and arousal indices (arousal/h)) and subjective evaluations of sleep quality were carried out each night in the laboratory. During in-home treatment, adherence for both therapies was assessed objectively (time on therapy) and subjectively (self-reported sleep diary). RESULTS: Objectively derived adherence values were comparable for CPAP and NI, with both treatment devices sharing similar usage per night (3.5 ± 2.5 vs. 3.6 ± 1.6 h/night; respectively) and the number of nights with at least 4 h of treatment (5.5 ± 4.3 vs. 6.8 ± 3.3 nights/trial, respectively). Self-reported adherence was significantly higher than objectively assessed adherence (p < 0.03). CONCLUSIONS: This study showed similar adherence to NI and CPAP over a short period of usage. A randomized clinical trial is now essential for determining the comparative effectiveness of NI therapy in relation to treatment with CPAP.

Acute phase protein and cytokine levels in serum and saliva: a comparison of detectable levels and correlations in a depressed and healthy adolescent sample.

Recent research has examined associations between inflammation and mental health, and has increasingly focused on utilising younger samples to characterise the temporal relationship between inflammatory responses and the emergence of other symptoms. These studies have typically used blood to measure inflammation, although rates of detection for many inflammatory markers appear to be low. Saliva is a safe and low-cost alternative, and adult research has shown that levels of some salivary markers correlate well with those in serum. However, no research has examined this association in young people. This study examined 16 inflammatory markers in serum and saliva in 17 depressed adolescents and 18 healthy controls, aged 13-18 years. In general, detection rates were higher in saliva compared to in serum. When non-detectable levels were excluded, serum levels of C-reactive protein (CRP) correlated with salivary CRP (r=0.424, p=0.015), and this correlation appeared to only exist for those individuals with high levels of serum CRP (r=0.599, p=0.014). However, when non-detectable levels were included as zero, salivary levels of CRP, interleukin (IL)-2, IL-12p70, and interferon (IFN)-γ correlated with their serum counterparts. No significant clinical group differences in any acute phase proteins or cytokines were present. This study suggests that saliva can be used to measure inflammation in studies with adolescent participants, especially CRP, as it appears to correlate with systemic inflammation for those individuals who are expected to have high levels of inflammation. Implications for future directions in research on salivary inflammatory markers are discussed.

Pilot study of a mindfulness-based, multi-component, in-school group sleep intervention in adolescent girls.

AIM: Existing literature links poor sleep and anxiety symptoms in adolescents. This pilot study aimed to develop a practical method through which a program to improve sleep could reach adolescents in need and to examine the feasibility of a mindfulness-based, multi-component group sleep intervention using sleep and anxiety as outcome measures. METHODS: Sixty-two grade 9 students (aged 13-15) at a girls' school were screened with the Pittsburgh Sleep Quality Index (PSQI) and Spence Children's Anxiety Scale (SCAS). Ten participants with self-reported poor sleep were enrolled into a six-session program based on Bootzin & Stevens, with added stress/anxiety-specific components. Sessions covered key aspects of basic mindfulness concepts and practice, sleep hygiene, sleep scheduling, evening/daytime habits, stimulus control, skills for bedtime worries and healthy attitudes to sleep. Treatment changes were measured by pre-post scores on the PSQI, SCAS and 7-day actigraphy-measured sleep. RESULTS: The program demonstrated high acceptability, with a completion rate of 90%. Based on effect-size analysis, participants showed significant improvement on objective sleep onset latency (SOL), sleep efficiency and total sleep time; actigraphy data also showed significantly earlier bedtime, rise time and smaller day-to-day bedtime variation. Post-intervention global PSQI scores were significantly lower than that of pre-intervention, with significant improvement in subjective SOL, sleep quality and sleep-related daytime dysfunction. There were small improvements on some subscales of the SCAS, but change on its total score was minimal. CONCLUSIONS: A mindfulness-based, multi-component, in-school group sleep intervention following brief screening is feasible, and has the potential to improve sleep. Its impact on anxiety needs further investigation.

Sleep and cardiovascular regulation.

Normal sleep has a profound effect on the cardiovascular system, reducing cardiovascular activity throughout non-rapid eye movement sleep; changes that are modified and augmented by circadian system influence. There is also evidence that sleep-initiated changes in autonomic balance may in turn modify the development of sleep within a night, particularly the development of slow wave sleep. It is assumed that the cardiovascular changes that accompany sleep reflect a functional aspect of sleep, although the precise functional role has not been agreed upon. Nevertheless, there is good evidence that the cardiovascular changes that occur during normal sleep are beneficial for the cardiovascular system. Arousals from sleep, which are common even in normal sleep, are associated with a surge in activity in cardiorespiratory systems, with marked effects on the sleep-related pattern of cardiovascular activity when they occur frequently. Despite the importance of this aspect of sleep, controversy remains as to both the nature of the activation response and the circumstances under which it is elicited. The concept that sleep-related changes in cardiovascular activity are beneficial leads to the corollary that sleep disturbance would result in adverse cardiovascular consequences. While there is strong empirical evidence for such a relationship, it remains unclear whether this is a direct effect or, as has been suggested recently, the effect of disturbed sleep is mediated via stress-related modification of neuroendocrine systems.