Regulation of the Phonotactic Threshold of the Female Cricket, Acheta domesticus: Juvenile Hormone III, Allatectomy, L1 Auditory Neuron Thresholds and Environmental Factors

Juvenile hormone III (JHIII), when applied to the abdomen of 1-day-old female Acheta domesticus (in quantities that would create JHIII titers in the hemolymph that were within the range measured in females of this species) caused a significant decrease in phonotactic thresholds (Fig. 1). Removal of the corpora allata from 5-day-old females with low phonotactic thresholds caused significantly increased phonotactic thresholds 2-5 days later. After a temporary increase (24 h) of, on average, about 25 dB, the phonotactic thresholds drop to about 10 dB above preallatectomy levels (Fig. 2), but remain significantly higher than controls. Application of JHIII to allatectomized females, with a mean increase in thresholds of 20 dB, results in significantly decreased thresholds (mean of about 20 dB) over the next 6 h (Fig. 3). Exposure to males 1 week before the imaginal molt causes the phonotactic thresholds of postimaginal females to drop 1-2 days significantly earlier than controls (Fig. 4). One- and 3-day-old females, phonotactically tested only once, exhibit lower thresholds in the early morning than they do in the late afternoon (Fig. 5). Five-day-old females do not exhibit such a diurnal rhythm. Phonotactically testing females more than once a day significantly influences their phonotactic thresholds (Figs. 6, 7). In 1-day-old females, with high (above 70 dB) phonotactic thresholds, the threshold of their L1 auditory interneurons can be 30 dB or more below their phonotactic threshold (Fig. 8). In females with phonotactic thresholds of 70 dB or lower, the L1 threshold is within 10 dB of their phonotactic threshold. Both JHIII and allatectomy influence phonotactic and L1 thresholds in a similar manner

Addressing climate change with behavioral science: a global intervention tournament in 63 countries

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions’ effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior—several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people’s initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors

P-22 Phonotaxis in Male House Crickets, Acheta domesticus

Calls of male crickets convey both reproductive and territorial intentions of the caller. Reproductively mature conspecific females use these calls to judge the quality of the caller and walk toward the source of the call (positive phonotaxis). Males of a few cricket groups also exhibit positive phonotaxis though for different proximate reasons than those hypothesized for females. We placed male house crickets, Acheta domesticus, in a circular arena and presented them with electronically synthesized model calls that differed from each other only in syllable periods. Seven syllable periods that ranged from 30msec to 90msec were used in this setup. Our Results revealed that male responses to calls with a syllable period of 50 msec had an earlier commencement and were more consistent than those of any other syllable period. However, age led to a progressive change in male responses and eventually resulted in those that were more than a month old responding to different syllable periods indiscriminately. The tuning of male and female auditory systems to calls of similar temporal structure indicates a common underlying genetic basis

Assessing the Impact of Exposure to a Naturalistic Paradigm

This session will report on the results of a survey about the students’ perceptions on the study of the unit of evolution in a general biology course. The items evaluated included prior exposure to evolutionary ideas, understanding of the central tenets of evolutionary theory, impact on faith and the learning environment. Our study revealed that almost 91% of the participants reported growth or stasis in their faith. This study is positioned as a first in a series of studies in which we will evaluate the impact of early exposure to the naturalistic paradigm of evolution on student engagement in upper division biology courses as well as probing students’ perception of how this experience might influence their faith commitments

Student Perception on the Study of Evolution in a General Biology Course in a Christian College

This study investigated students’perceptions of the study of evolution in a small conservative Christian college. Students’ interest in the subject is influenced by several factors, including prior exposure to the material, students’ belief system,and the instructors’ attitudes towards the subject. These factors also determine the ability of students to understand, discuss, and analyze evolutionary-leaning arguments. Participants were students in a Foundations of Biology class. They completed a survey instrument that was administered by the college\u27s Center for Teaching and Learning Excellence. Analysis of the results indicates students are interested in the material, think it is important to study, and value discussing these issues in a supportive Christian environment. Implications for strengthening faith integration and student intellectual growth are discussed

P-32 Evaluating phonotaxis variability and selective processing of its underlying neural elements in an insect model

Selective phonotaxis exhibited by female Acheta domesticus and Gryllus bimaculatus has been documented in multiple studies. While some females are finely tuned and attracted to calling songs with syllable periods matching those of the natural calls of the male, other females respond phonotactically to calls with a wider range of syllable periods. Multiple studies have also provided evidence supporting the importance of prothoracic auditory neurons such as L3/AN2 in the selective phonotaxis of female crickets. We have developed a neuronal model, which includes the contralateral omega 1 neuron inhibiting a source of delayed inhibition as well as a source of selective excitation onto the L3. The inhibition by ON1 is downregulated by Juvenile Hormone III and PTX, which increases selectivity to syllable period, and is upregulated by histamine, which leads to decreased selectivity. Testing this model has included prothoracic injections of JHIII, histamine and PTX followed by an assessment of phonotaxis and L3’s selective responses using electrophysiology. The model so far remains valid as we continue to test it. Preliminary data shows the effect of H -7 (a kinase inhibitor) on phonotaxis before and after injection parallels the effect of L3’s response. Additionally, exposure to males, decreases selectivity in females. Electrophysiology of L3’s response in exposed females is currently being evaluated

Morphology and Physiology of Local Auditory Interneurons in the Prothoracic Ganglion of the Cricket Acheta domesticus

The omega-neuron 2 (ON2) is an auditory interneuron in Acheta domesticus that could play an important role in prothoracic auditory information processing. ON2 neurons were intracellularly recorded and iontophoretically stained with lucifer-yellow. The morphology of ON2 is similar to that described in other cricket species. Wholemounts and transverse sections of prothoracic ganglia show that ON2 branches cover the same regions as the omega-neuron 1 (ON1) branches except that ON2 has crossover branches in the anterior ring tract from both the ipsilateral and contralateral side. Auditory responses of ON2 are measured with spiking thresholds of about 60 dB SPL at 16 kHz (courtship song frequency) and about 80 dB SPL at 5 kHz (calling song frequency) under open field and closed field (monaural) stimulation. Open and closed field stimulations show almost identical threshold curves and response magnitudes to soma-ipsilateral and soma-contralateral stimulation. These data do not support a function of ON2 for directional hearing. In addition to excitation, ON2 receives inhibitory inputs from both ears at 5 and 16 kHz. Sub-threshold inhibition is obvious in responses with open and closed field stimulation at 5 kHz. Responses show mixed excitation and inhibition at intensities above 80 dB SPL at 5 and 16 kHz. These data confirm previous immunohistochemical results showing GABAergic input to ON2 in Gryllus bimaculatus. Two newly described local neurons (\u27LNi\u27, \u27LN2\u27), which are probably non-spiking and have low 5-kHz thresholds, could be candidates for the inhibitory input to ON2

Neonatal mortality in Kenyan hospitals: a multisite, retrospective, cohort study

Background Most of the deaths among neonates in low-income and middle-income countries (LMICs) can be prevented through universal access to basic high-quality health services including essential facility-based inpatient care. However, poor routine data undermines data-informed efforts to monitor and promote improvements in the quality of newborn care across hospitals.Methods Continuously collected routine patients’ data from structured paper record forms for all admissions to newborn units (NBUs) from 16 purposively selected Kenyan public hospitals that are part of a clinical information network were analysed together with data from all paediatric admissions ages 0–13 years from 14 of these hospitals. Data are used to show the proportion of all admissions and deaths in the neonatal age group and examine morbidity and mortality patterns, stratified by birth weight, and their variation across hospitals.Findings During the 354 hospital months study period, 90 222 patients were admitted to the 14 hospitals contributing NBU and general paediatric ward data. 46% of all the admissions were neonates (aged 0–28 days), but they accounted for 66% of the deaths in the age group 0–13 years. 41 657 inborn neonates were admitted in the NBUs across the 16 hospitals during the study period. 4266/41 657 died giving a crude mortality rate of 10.2% (95% CI 9.97% to 10.55%), with 60% of these deaths occurring on the first-day of admission. Intrapartum-related complications was the single most common diagnosis among the neonates with birth weight of 2000 g or more who died. A threefold variation in mortality across hospitals was observed for birth weight categories 1000–1499 g and 1500–1999 g.Interpretation The high proportion of neonatal deaths in hospitals may reflect changing patterns of childhood mortality. Majority of newborns died of preventable causes (>95%). Despite availability of high-impact low-cost interventions, hospitals have high and very variable mortality proportions after stratification by birth weight

Drosophila melanogaster as a genetic model system to study neurotransmitter transporters

The model genetic organism Drosophila melanogaster, commonly known as the fruit fly, uses many of the same neurotransmitters as mammals and very similar mechanisms of neurotransmitter storage, release and recycling. This system offers a variety of powerful molecular-genetic methods for the study of transporters, many of which would be difficult in mammalian models. We review here progress made using Drosophila to understand the function and regulation of neurotransmitter transporters and discuss future directions for its use