scholarly journals Physical factors affecting the cost and efficiency of sound production in the treefrog Hyla versicolor

2001 ◽  
Vol 204 (1) ◽  
pp. 69-80 ◽  
Author(s):  
J.D. McLister

The metabolic cost, energy output and efficiency (i.e. the ratio of energy output to metabolic cost) of sound production were compared among male grey treefrogs (Hyla versicolor) as a function of body size and temperature. The effects of call length (in notes per call) and dominant frequency (in kHz) were also considered. Cost, determined from the amount of oxygen consumed, averaged 12.1 mJ per note and was dependent only upon body mass. Acoustic energy per note, determined from oscillograms of recorded calls, averaged 0.34 mJ and was dependent only upon temperature. Conventional theory suggests that the efficiency of sound production should be a function of the ratio of the linear size of the radiating structures to the wavelength of the sound generated (i.e. efficiency is assumed to be a function of the product of mass(0.33) and frequency), but efficiency in H. versicolor was found to be a function of the product of temperature(2.1) and mass(−1.08). Adjusting for temperature and body mass, the efficiency of sound production in H. versicolor (average 2.4 %) is greater than the efficiency of other frog species for which data are available. Temperature may affect acoustic energy output because trunk muscle contraction speed increases with temperature, which increases the velocity of airflow across the vocal cords.

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 502
Author(s):  
Junior Corneille Fingu-Mabola ◽  
Frédéric Francis

Aphids are responsible for the spread of more than half of the known phytovirus species. Virus transmission within the plant–aphid–phytovirus pathosystem depends on vector mobility which allows the aphid to reach its host plant and on vector efficiency in terms of ability to transmit phytoviruses. However, several other factors can influence the phytoviruses transmission process and have significant epidemiological consequences. In this review, we aimed to analyse the aphid behaviours and influencing factors affecting phytovirus spread. We discussed the impact of vector host-seeking and dispersal behaviours mostly involved in aphid-born phytovirus spread but also the effect of feeding behaviours and life history traits involved in plant–aphid–phytovirus relationships on vector performances. We also noted that these behaviours are influenced by factors inherent to the interactions between pathosystem components (mode of transmission of phytoviruses, vector efficiency, plant resistance, …) and several biological, biochemical, chemical or physical factors related to the environment of these pathosystem components, most of them being manipulated as means to control vector-borne diseases in the crop fields.


1934 ◽  
Vol 25 (4) ◽  
pp. 491-494 ◽  
Author(s):  
P. A. Buxton

During the last decade, entomologists have made progress in understanding the environment in which certain insects live; in particular, we begin to understand the effect of certain physical and chemical factors, which make up a part of the environment. With this gain in knowledge, it is sometimes possible to forecast outbreaks of insects and of diseases conveyed by them, and one can sometimes say that a particular alteration of the environment will result in loss or gain. But so far as mosquitos are concerned, one must admit that though much work has been devoted to the analytical study of the water in which the early stages are passed, the results are disappointing. A consideration of the published work suggests several reasons for this. Investigation into the ecology of the mosquito has had a vogue, and much of it has been done by workers who were isolated and whose knowledge of chemical technique and freshwater biology was limited. Apart from that, the inherent difficulties are great, for the worker must hunt for the limiting chemical and physical factors among a host of others which are doubtless unimportant, and there are few clues to indicate which of the chemical constituents of the water affects the mosquito. The data are therefore voluminous and it is difficult to reduce them to order and present them so that they can be readily understood.


2002 ◽  
Vol 205 (15) ◽  
pp. 2183-2188 ◽  
Author(s):  
M. A. Connaughton ◽  
M. L. Fine ◽  
M. H. Taylor

SUMMARYThe influence of temperature, size and season on the sounds produced by the sonic muscles of the weakfish Cynoscion regalis are categorized and used to formulate a hypothesis about the mechanism of sound generation by the sonic muscle and swimbladder. Sounds produced by male weakfish occur at the time and location of spawning and have been observed in courtship in captivity. Each call includes a series of 6-10 sound pulses, and each pulse expresses a damped, 2-3 cycle acoustic waveform generated by single simultaneous twitches of the bilateral sonic muscles. The sonic muscles triple in mass during the spawning season, and this hypertrophy is initiated by rising testosterone levels that trigger increases in myofibrillar and sarcoplasmic cross-sectional area of sonic muscle fibers. In response to increasing temperature, sound pressure level (SPL), dominant frequency and repetition rate increase, and pulse duration decreases. Likewise, SPL and pulse duration increase and dominant frequency decreases with fish size. Changes in acoustic parameters with fish size suggest the possibility that drumming sounds act as an `honest' signal of male fitness during courtship. These parameters also correlate with seasonally increasing sonic muscle mass. We hypothesize that sonic muscle twitch duration rather than the resonant frequency of the swimbladder determines dominant frequency. The brief (3.5 ms), rapidly decaying acoustic pulses reflect a low-Q, broadly tuned resonator, suggesting that dominant frequency is determined by the forced response of the swimbladder to sonic muscle contractions. The changing dominant frequency with temperature in fish of the same size further suggests that frequency is not determined by the natural frequency of the bladder because temperature is unlikely to affect resonance. Finally, dominant frequency correlates with pulse duration (reflecting muscle twitch duration),and the inverse of the period of the second cycle of acoustic energy approximates the recorded frequency. This paper demonstrates for the first time that the dominant frequency of a fish sound produced by a single muscle twitch is apparently determined by the velocity of the muscle twitch rather than the natural frequency of the swimbladder.


2021 ◽  
pp. 1-36
Author(s):  
Vahideh Angardi ◽  
Ali Ettehadi ◽  
Özgün Yücel

Abstract Effective separation of water and oil dispersions is considered a critical step in the determination of technical and economic success in the petroleum industry over the years. Moreover, a deeper understanding of the emulsification process and different affected parameters is essential for cost-effective oil production, transportation, and downstream processing. Numerous studies conducted on the concept of dispersion characterization indicate the importance of this concept, which deserves attention by the scientific community. Therefore, a comprehensive review study with critical analysis on significant concepts will help readers follow them easily. This study is a comprehensive review of the concept of dispersion characterization and conducted studies recently published. The main purposes of this review are to 1) Highlight flaws, 2) Outline gaps and weaknesses, 3) Address conflicts, 4) Prevent duplication of effort, 5) List factors affecting dispersion. It was found that the separation efficiency and stability of dispersions are affected by different chemical and physical factors. Factors affecting the stability of the emulsions have been studied in detail and will help to look for the right action to ensure stable emulsions. In addition, methods of ensuring stability, especially coalescence are highlighted, and coalescence mathematical explanations of phenomena are presented.


2021 ◽  
Vol 9 (2) ◽  
pp. 105-114
Author(s):  
Mahbobeh Firooz ◽  
◽  
Fereshteh Eidy ◽  
Zohreh Abbasi ◽  
Seyed Javad Hosseini ◽  
...  

Context: Infantile Colic (IC) is an essential problem in infancy that is influenced by factors related to infants and parents. The parental factors associated with colic have not been comprehensively assessed. Objectives: The present systematic review was conducted to investigate the parental factors affecting the incidence of IC. Data Sources: Databases, including PubMed, Web of Science, Scopus, Science Direct, Google scholar, as well as Scientific Information Database (SID), and Magiran (Iranian websites) were searched to identify all eligible papers concerning parental factors affecting infantile CI. The registration number of this study was CRD42020163518 in the PROSPERO database. Study Selection: A total of 423 relevant articles published up to the end of December 2019 were assessed. The selected articles were screened based on duplicated, eligibility criteria, and quality appraisal. The main inclusion criteria were observational studies and articles in Persian and English languages. Data Extraction: The Mesh keywords and Boolean operators included (“risk factors” OR “causality”) AND (“parents” OR “fathers” OR “mothers”) AND (“infant”) AND (“colic”). Consequently, 18 papers were thoroughly studied and the related data were extracted. Two researchers independently performed the data extraction and quality assessment based on the STROBE checklist from the observational studies. The information of selected studies was recorded in a table, i.e. consisted of authors’ names, purpose, design, population, and main results. Results: Final articles consisted of 10 prospective, 6 cross-sectional, and 2 case-control studies. Eventually, the effective factors were placed in 6 categories, as follows: psychological factors, physical factors, taking medications, perinatal factors, family’s socioeconomic status, and maternal diet. The most important characteristics predisposing to IC were parental depression, anxiety, smoking, maternal history of migraine, young age, primiparity, low family support, high socioeconomic status, high-risk pregnancies, and delivery, taking antibiotics, as well as the consumption of celery, onions, and bananas. Conclusions: Various parental factors affect the incidence of colic. Identifying these risk factors and accurate planning can be beneficial in the prevention and treatment of IC.


Proceedings ◽  
2020 ◽  
Vol 61 (1) ◽  
pp. 5
Author(s):  
Karolina Osowiecka ◽  
Natalia Pokorna ◽  
Damian Skrypnik

Rationale: Intestinal microbiota plays a significant role in the human body. A range of negative factors may lead to dysbiosis, which results in many diseases (e.g., cancer) and metabolic disorders. It was shown that people with a body mass index (BMI) of ≥25 kg/m2 present diminished microbial diversity. Additional negative factors such as stress, the use of non-steroidal anti-inflammatory drugs (NSAID) and proton pomp inhibitors (PPI) may result in greater dysbiosis compared to people with normal body mass. The aim of the study was to compare the incidence of negative factors affecting the intestinal microbiota in people with excessive body mass vs. people with normal body mass. Methods: The study involved volunteers aged 18–65 years: 582 people with normal BMI (18.5–24.99 kg/m2) and 538 people with BMI ≥ 25 kg/m2. The study was conducted using the author’s survey by the Computer-Assisted Web Interviewing method. The survey included the questions on sociodemographic features, level of physical activity, frequency of smoking, and stress. Frequency of NSAID and PPI use was also investigated. BMI was used to assess nutritional status. For statistics the Fisher test was implemented. p-Value < 0.05 was considered significant. Results: Women predominated in the study (p < 0.0001). People with normal BMI had a significantly higher level of physical activity (p < 0.0001) and smoked less (p = 0.0356). People with excessive body mass were less likely to report illness (p = 0.0004), but more often they took PPI (p = 0.0337). Conclusions: People with BMI ≥ 25 kg/m2 present more factors which may result in dysbiosis and lead to dysbiosis-related health problems in future compared to people with normal BMI.


2013 ◽  
Vol 217 (5) ◽  
pp. 787-795 ◽  
Author(s):  
S. Lazzer ◽  
P. Taboga ◽  
D. Salvadego ◽  
E. Rejc ◽  
B. Simunic ◽  
...  

1993 ◽  
Vol 178 (1) ◽  
pp. 21-37 ◽  
Author(s):  
W. J. Bailey ◽  
P. C. Withers ◽  
M. Endersby ◽  
K. Gaull

1. The metabolic costs of calling for male Requena verticalis Walker (Tettigoniidae: Listroscelidinae) were measured by direct recordings of oxygen consumption. The acoustic power output was measured by sound pressure levels around the calling bushcricket. 2. The average metabolic cost of calling was 0.143 ml g-1 h-1 but depended on calling rate. The net metabolic cost of calling per unit call, the syllable, was calculated to be 4.34×10-6+/−8.3×10-7 ml O2 syllable-1 g-1 body mass (s.e.) from the slope of the relationship between total V(dot)O2 and rate of syllable production. The resting V(dot)O2, calculated as the intercept of the relationship, was 0.248 ml O2 g-1 body mass h-1. 3. The energetic cost of calling for R. verticalis (average mass 0.37 g) was estimated at 31.85×10-6 J syllable-1. 4. Sound pressure levels were measured around calling insects. The surface area of a sphere of uniform sound pressure level [83 dB SPL root mean square (RMS) acoustic power] obtained by these measurements was used to calculate acoustic power. This was 0.20 mW. 5. The metabolic efficiency of calling, based on total metabolic energy utilisation, was 6.4 %. However, we propose that the mechanical efficiency for acoustic transmission is closer to 57 %, since only about 10 % of muscle metabolic energy is apparently available for sound production. 6. R. verticalis emits chirps formed of several syllables within which are discrete sound pulses. Wing stroke rates, when the insect is calling at its maximal rate, were approximately 583 min-1. This is slow compared to the rates observed in conehead tettigoniids, the only other group of bushcrickets where metabolic costs have been measured. The thoracic temperatures of males that had been calling for 5 min were not significantly different from those of non-calling males. 7. For R. verticalis, calling with relatively slow syllable rates may reduce the total cost of calling, and this may be a compensatory mechanism for their other high energetic cost of mating (a large spermatophylax).


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