scholarly journals Comparative Analysis of Acoustic Propagation Parameters of Natural Sounds ofAnopheles gambiae s.sandOdorrana tormotaSignificant in Mosquito Startle

2019 ◽  
Author(s):  
P. A. Mang’are ◽  
F. G. Ndiritu ◽  
S. K. Rotich ◽  
J. K. Makatiani ◽  
B. W. Rapando
Keyword(s):  
Anopheles Gambiae ◽  
Acoustic Energy ◽  
Peak Amplitude ◽  
Signal Power ◽  
Maximum Frequency ◽  
Postgraduate Students ◽  
Amplitude Maximum ◽  
Biophysical Society ◽  
Propagation Parameters ◽  
Frequency Maximum

AbstractAcoustics of varied frequency ranges generated naturally by animals or artificially by electronic devices have shown startle effect to insects. It has been shown that mosquitoes use the reactive near-field in antennae communication with negative phonotaxis in maleAedes diantaeusevoked by low frequency acoustic signals of a carrier frequency 140–200 Hz. Also, studies with the 35-60 kHzOdorrana tormotasound recorded a 46 % repellence in femaleAnopheles gambiae, the malaria vectors. Declining malaria morbidity and mortality is attributed to current vector and pathogen interventions. However, the rate of decline in malaria morbidity and mortality is impeded by buildup of resistance in pathogens and vectors to chemicals. This study therefore characterised animal sounds essential for further investigation in the control of malaria through mosquito startle. The research determined, analysed and compared the acoustic propagation parameters of the recorded natural sounds of the maleAnopheles gambiae, femaleAnopheles gambiaeandOdorrana tormotausing Avisoft SASLAB Pro and Raven Pro 1.5. All sounds were observed to have frequency modulation with harmonics stretching to ultrasonic levels. Uniquesly, the sound ofO. tormotashowed constant frequency modulation. The pupae ofA. gambiaewere reared in vials quarter filled with water and covered with a net at 60-80 % humidity, 25±2 °C temperature and equal light-darkness hour cycle at Kenya Medical Research Institute (KEMRI) entomology laboratories. The parameters showed a significant deference in fundamental frequency (maximum entire), Peak amplitude (maximum), peak amplitude (mean), Peak amplitude (mean entire) and peak amplitude (maximum entire) of the sound of maleA. gambiaeandO. tormota(p < 0.05). The maximum frequency (minimum entire) of both sexes ofA. gambiaewas equal (1.90 kHz) with variability being observed in maximum frequency (end), maximum frequency (maximum), maximum frequency (mean), maximum frequency (maximum entire) and maximum frequency (mean entire). Frequency (maximum). A paired samples t-test comparison of the maximum frequency (mean), maximum frequency (maximum), maximum frequency (end), maximum frequency (maximum entire) and maximum frequency (mean entire) of the sound of the femaleA. gambiaeand maleA. gambiaeindicated no significant difference between the sounds (p > 0.05). The maximum frequency (mean) of the sounds of both sexes ofA. gambiaecorrelated highly negative (r = −0.658). The bandwidth (end), bandwidth (maximum), bandwidth (maximum entire), peak amplitude (mean) and bandwidth (mean entire) of the sound of the male compared with femaleA. gambiaediffered significantly. The signal power for the non-pulsate sounds of the maleA. gambiaeremained almost constant at 80 dB from 10 kHz to 65 kHz beyond which the acoustic energy declining to 45 dB. Also, the sounds of the femaleA. gambiaedid not exhibit any spikes in power but remained steady at 85 dB from 10 kHz up to 60 kHz beyond which the acoustic energy declined to 50 dB. The signal power of the pulsate sound ofO. tormotawas 89 dB. The propagation parameters of the male mosquito and O. tormota compared favourably indicating its potential in the startle of the female mosquito.The author summaryPhilip Amuyunzu Mang’are is a PhD. Physics student in Egerton University. He has authored many papers and books. He is currently a Lecturer of Physics (Electronics), Masinde Muliro University of Science and Technology. He is a member of the Biophysical Society and the current President of Biophysical society (Kenya). Prof. Ndiritu F. Gichuki, is a Professor of Physics Egerton University. Currently he is the Registrar Academic Affairs in Chuka University. His vast experience has seen him supervise many postgraduate students who have taken key positions in the society. Prof. Samwel Rotich is a Profesor of Physics in Moi University specialising in Electronics. He has a wide experience in Physics and Biophysics. He is a registered member of the Biophysical Society and the Patron of Biophysical Society Kenya Chapter. He has published many papers and supervised many postgraduate students. Dr. Makatiani Kubochi is a Lecturer in Moi University with vast experience in entomology. She has published many papers and supervised many postgraduate students. Dr. Rapando Bernard Wakhu is a renown theoretical Physicist with experience in acoustics and Fourier analysis based in Masinde Muliro University of Science and Technology. He has supervised many postgraduate students and published many papers.

scholarly journals Critical analysis of the mosquito repellency evoked by the 10-34 kHz recorded animal sounds: The case of the African female A. gambiae s.s

2019 ◽  
Author(s):  
Philip Amuyunzu Mang’are ◽  
Francis Ndiritu Gichuki ◽  
Samwel Rotich ◽  
Jacqueline K. Makatiani ◽  
Bernard Rapando Wakhu
Keyword(s):  
Anopheles Gambiae ◽  
Blood Meal ◽  
Science And Technology ◽  
Delphinapterus Leucas ◽  
Anopheles Gambiae S.S ◽  
Male And Female ◽  
Postgraduate Students ◽  
Biophysical Society ◽  
Male Mosquito ◽  
Protection Index

AbstractAnimals sounds have been mimicked in electronic mosquito repellents (EMRs) and exploited as a tool in the control of malaria by targeting the vector, the female Anopheles gambiae s.s. The claimed mosquito repellency of 30.3 % due to Anti-Pic®, an electronic mosquito repellent, had failed to be confirmed in subsequent studies. However, studies on mosquito startle based on initial behavioural activities without an attractant yielded 34.12 % repellency elicited by the 10-34 kHz recorded sound of O. tormota. Other malaria intervention measures involving the use of chemicals have been impeded by the pathogen and vector resistance hence slowing down the rate of decline of malaria morbidity and mortality. The research thus focused on the analytical study of the African female A. gambiae s.s repellency evoked by the 10-34 kHz recorded animal sound of male mosquito, Anopheles gambiae and Delphinapterus leucas. Landing rates and behavioural startle responses of the mated female A. gambiae on food attractant evoked by the individual sound of the male mosquito, A. gambiae, O. tormota and D. leucas were determined and analysed. The male and female A. gambiae were bred and reared under controlled laboratory conditions of 60-80 % humidity, 25±2 °C temperature with equal light-darkness hour cycle in KEMRI, entomology laboratories. Isolation of the male and female mosquitoes from a swarm was based on physical features and affinity to blood meal. The sounds of O. tormota and D. leucas were acquired and the sound of the male A. gambiae were recorded from the Kenya Medical Research Institute (KEMRI) entomology laboratory, Kisumu. The sounds were filtered into 10-34 kHz frequency band and analysed using Avisoft-SAS LAB Pro version 5.2 and Raven Pro 1.5 software. The sound of O. tormota was also studied. A fighto-Y glass cage well designed into control, neutral and treatment chambers was used in the study. Both control and treatment chambers were connected to blood meal maintained at 38.60°C. The treatment cage was also connected to the source of sound and a swarm of 50 female mosquitoes into the neutral cage and observed for 1,200 s. The sounds of the A. gambiae, O. tormota and D. leucas yielded 2.10, 2.20 and 3.00 landings/minute respectively associated with adverse behaviour. The protection index (PI) anchored on the number of mosquitoes that landed, probed and fed on the blood meal in the treatment and neutral cage for the sounds of the A. gambiae, O. tormota and D. leucas was 42.73 %, 40.24 % and 10.64 % respectively. The sound of the A. gambiae was characterised by steady and minimally dipped pulsate acoustic power with wide bandwidth. The protection index achieved by the sound of the male A. gambiae did not differ significantly from the sound of O. tormota (0.1740 > 0.05), though differed significantly from the sound emitted from the Anti-Pic® EMR (p = 5.3440 x 10−5).The author summaryPhilip Amuyunzu Mang’are is a PhD. Physics student in Egerton University. He has authored many papers and books. He is currently a Lecturer of Physics (Electronics), Masinde Muliro University of Science and Technology. He is a member of the Biophysical Society and the current President of Biophysical society (Kenya). Prof. Ndiritu F. Gichuki, is a Professor of Physics Egerton University. Currently he is the Registrar Academic Affairs in Chuka University. His vast experience has seen him supervise many postgraduate students who have taken key positions in the society. Prof. Samwel Rotich is a Profesor of Physics in Moi University specialising in Electronics. He has a wide experience in Physics and Biophysics. He is a registered member of the Biophysical Society and the Patron of Biophysical Society Kenya Chapter. He has published many papers and supervised many postgraduate students. Dr. Makatiani Kubochi is a Lecturer in Moi University with vast experience in entomology. She has published many papers and supervised many postgraduate students. Dr. Rapando Bernard Wakhu is a renown theoretical Physicist with experience in acoustics and Fourier analysis based in Masinde Muliro University of Science and Technology. He has supervised many postgraduate students and published many papers.

scholarly journals Meteorological noise in wire strainmeter data from Parkfield, California

1979 ◽  
Vol 69 (6) ◽  
pp. 1983-1988
Author(s):  
N. R. Goulty ◽  
P. M. Davis ◽  
R. Gilman ◽  
N. Motta
Keyword(s):  
Earthquake Prediction ◽  
Residual Strain ◽  
San Andreas Fault ◽  
Peak Amplitude ◽  
Wiener Filtering ◽  
Base Line ◽  
Signal Power ◽  
San Andreas ◽  
Filtering Technique ◽  
Strain Signal

abstract Four invar-wire strainmeters have been operated in shallow trench sites for 19 months beside the San Andreas Fault at Parkfield, California. Temperature and rainfall records were correlated with 1 yr of strainmeter data, and 90 per cent of the strain signal power at periods between 2 and 120 days was predicted entirely from these records, using a multi-channel, Wiener filtering technique. The residual strain series fluctuates with a peak-to-peak amplitude of nearly 10−6 strain. Anomalous strain signals taking place over several days would have to be larger than this to be identifiable. Previous work shows that signals of amplitude 10−7 strain are identifiable if they take place within hours. Deep creep events giving rise to such signals, which may occur as precursors to earthquakes, would need to be very large. Other workers have shown that shallow, short-base line tiltmeters in California are also very sensitive to meteorological noise. Strainmeter and tiltmeter installations can be made less sensitive to meteorological noise, either by manufacturing instruments with long (∼1 km) base lines, or by using tunnel or borehole sites (≳100 m deep). Proven instruments of these types are costly, unless an underground site was already available. However, if networks of shallow, shortbase line strainmeters or tiltmeters are to be used for earthquake prediction, it is obviously desirable to invest in at least a few installations which are less sensitive to noise of meteorological origin.

scholarly journals Description and comparison of Philippine hornbill (Bucerotidae) vocalizations

2019 ◽  
Vol 7 ◽  
Author(s):  
Shari Guerra ◽  
Juan Carlos Gonzalez ◽  
Emmanuel Francisco Rafael
Keyword(s):  
Effect Size ◽  
Peak Frequency ◽  
Maximum Frequency ◽  
Minimum Frequency ◽  
Allopatric Species ◽  
Species Pairs ◽  
In Captivity ◽  
Bioacoustic Analysis ◽  
Frequency Maximum

The role of vocalisation for the Philippine hornbills' ecology and speciation and their implication in understanding speciation is not well understood. We described and compared recorded calls of seven hornbill taxa in captivity namely Mindanao Wrinkled hornbill (Rhabdotorrhinus leucocephalus), Rufous-headed hornbill (Rhabdotorrhinus waldeni), Luzon Rufous hornbill (Buceros hydrocorax hydrocorax), Samar Rufous hornbill (Buceros hydrocorax semigaleatus), Mindanao Rufous hornbill (Buceros hydrocorax mindanensis), Mindanao Tarictic hornbill (Penelopides affinis), Samar Tarictic hornbill (Penelopides samarensis), Visayan Tarictic hornbill (Penelopides panini) and Luzon Tarictic hornbill (Penelopides manillae), as well as comparison with the non-native Papuan hornbill (Rhyticeros plicatus). Vocalisation analysis included call duration, minimum frequency, maximum frequency, bandwidth and peak frequency. For each species in the sample, the mean and standard deviation were used to calculate the Cohen’s d statistic by using an effect size calculator. Results showed that the effect size for minimum frequency was small for P. panini vs. P. samarensis and B. hydrocorax vs. B. h. mindanensis. However, bandwidth, duration, minimum frequency, maximum frequency and peak frequency have large effect sizes for the rest of the allopatric species pairs. Hornbills' conspicuous resonating calls are sufficiently quantifiable for bioacoustic analysis and may provide new insights for their taxonomic review.

Mistuning Analyses of a Bladed Disk: Pole-Zero and Modal Approaches

2008 ◽  
Author(s):  
Alok Sinha
Keyword(s):  
Natural Frequencies ◽  
Peak Amplitude ◽  
Mode Shapes ◽  
Bladed Disk ◽  
Amplitude Maximum ◽  
Excitation Frequencies ◽  
Amplitude Amplification

This paper examines the fundamental aspects of amplitude amplification due to mistuning in a bladed disk. Both pole-zero and modal approaches are used to understand the effects of changes in mode shapes and the natural frequencies on the minimum and maximum values of peak amplitudes among all blades over all excitation frequencies. The nature of variation of this peak amplitude is studied, and algorithms are discussed to determine the statistics of the peak amplitude, maximum and minimum values of the peak amplitude, and corresponding mistuning patterns.

scholarly journals VARIASI POLA VOKALISASI PADA TAKSONOMI ANAK JENIS ELANG-ULAR (Spilornis cheela) DI PKEK, GARUT, JAWA BARAT

Jurnal BIOMA ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. 1-9
Author(s):  
Devi Fauzia Dermi ◽  
Agung Sedayu ◽  
Ratna Komala
Keyword(s):  
Sampling Technique ◽  
Statistical Test ◽  
Morphological Data ◽  
Maximum Frequency ◽  
Analysis Software ◽  
Minimum Frequency ◽  
Continuous Sampling ◽  
Bird Of Prey ◽  
Frequency Maximum ◽  
Descriptive Method

Crested serpent eagle (Spilornis cheela) is a bird of prey with distinctive of uniue vocal. Based on several studies mentioned that there are differences in vocalization at the level of subspecies and is often used to study the role vocalization defining the subspecies in taxonomy. This research aimed to determine the role variation of vocalization pattern in taxonomy on subspecies eagle. The research was conducted from May to September 2017 at Kamojang Eagle Conservation Center. The method used is descriptive method with continuous sampling technique. The samples was an adult eagle from three subspecies serpent eagle. The location of observation determined by purposive sampling with the provisions listening post is less than 5 meters until 30 meters. The data is collected at 7 am to 5 pm. Data were analyzed using sound analysis software. The data taken are fundamental frequency, maximum frequency (MinF), minimum frequency (MinF) and duration. Differences between subspecies were analyzed using Kruskal Wallis and Mann-Whitney U statistical test with SPSS 17.0. The result of the research is The vocalizations can be utilized in the subspecies eagle taxonomy of the species to complement the morphological data, marked by significantly different results on each parameter of vocalization between (Spilornis cheela malayensis) and (Spilornis cheela natunensis). MaxF significantly different in (Spilornis cheela malayensis) and (Spilornis cheela bido), (Spilornis cheela natunensis) and (Spilornis cheela bido).

Ultimate resolution and information in electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 496-497
Author(s):  
D. Van Dyck
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Transfer Function ◽  
Information Transfer ◽  
Communication Channel ◽  
Structural Information ◽  
Information Rate ◽  
Noise Power ◽  
Signal Power ◽  
Imaging Device

An (electron) microscope can be considered as a communication channel that transfers structural information between an object and an observer. In electron microscopy this information is carried by electrons. According to the theory of Shannon the maximal information rate (or capacity) of a communication channel is given by C = B log2 (1 + S/N) bits/sec., where B is the band width, and S and N the average signal power, respectively noise power at the output. We will now apply to study the information transfer in an electron microscope. For simplicity we will assume the object and the image to be onedimensional (the results can straightforwardly be generalized). An imaging device can be characterized by its transfer function, which describes the magnitude with which a spatial frequency g is transferred through the device, n is the noise. Usually, the resolution of the instrument ᑭ is defined from the cut-off 1/ᑭ beyond which no spadal information is transferred.

Study-work-life balance of international students in the context of temporal boundaries

2019 ◽  
Vol 7 (2) ◽  
pp. 63-79
Author(s):  
Megan O'Mahony ◽  
Debora Jeske
Keyword(s):  
International Students ◽  
Social Withdrawal ◽  
Work Life ◽  
Work Life Balance ◽  
Boundary Management ◽  
Structured Interviews ◽  
Time Zone ◽  
Life Balance ◽  
Postgraduate Students ◽  
Personal Challenges

The goal of this qualitative study was to examine the experience of study-work-life balance among international students who were separated from their family both geographically and temporally. Using 10 semi-structured interviews with postgraduate students and thematic analysis, several themes were identified. These included boundary management shifts due to study/work demands and time zone differences. In addition, students reported social and personal challenges (in terms of family’s expectations, relationships maintenance, socialization in host country). Temporal boundaries contributed to social withdrawal and isolation among students, many of which were heavily reliant on their own family network for support. The findings strengthen the argument that time difference impacts the boundary management and social experience of international students.

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