Hemolymph homeostasis in relation to diel feeding activity and microclimate in the prototypal land isopod Ligia pallasii

2000 ◽  
Vol 78 (4) ◽  
pp. 588-595 ◽  
Author(s):  
Thomas H Carefoot ◽  
Jonathan Wright ◽  
Steven C Pennings ◽  
Andreas Ziegler ◽  
Martin Zimmer ◽  
...  

Twenty-four-hour variability in hemolymph osmolality was assessed in a field population of the semiterrestrial isopod Ligia pallasii and related to feeding activity and microenvironmental conditions of relative humidity (RH) and temperature in the species' habitats. Hemolymphs were also analyzed for levels of ammonia and glucose as indicators of digestive and absorptive activities. Comparative data on hemolymph osmolality and microhabitat conditions were also obtained for several ligiid species in Hawai'i. Late-morning peaks in hemolymph osmolality in L. pallasii were coincidental with peaks in ammonia and glucose and with predicted times of digestion/absorption based on observed feeding activity in the population, suggesting that the elevations in osmolality were due to salt-loading from the species' seaweed diet. Uniformity of microenvironmental conditions of RH and temperature in Ligia's supralittoral habitat, whether temperate or tropical, and regardless of time of day or localized weather conditions, suggests that dietary salt-loading is likely the greatest challenge to osmotic homeostasis in ligiids. This feature and other aspects of hemolymph osmolality in ligiids are discussed in the context of colonization of land by prototypal terrestrial isopods.

1983 ◽  
Vol 73 (4) ◽  
pp. 609-617 ◽  
Author(s):  
W. G. Vogt ◽  
T. L. Woodburn ◽  
R Morton ◽  
B. A. Ellem

AbstractField populations of Lucilia cuprina (Wied.) in New South Wales were sampled for periods of 3 h on numerous occasions between 1975 and 1982 using West Australian blowfly traps. Ambient temperature, wind speed, relative humidity and solar radiation explained 77·4% of the within-day deviance of the catches. Temperature alone accounted for 74·9% of this deviance, indicating that the other variables, although significant, did not greatly affect trap catches. As air temperatures increased, log catch rates increased linearly up to 26°C and then remained constant up to 35°C. Wind speeds above 25 m/s caused a linear decline in log catch rates. Log catch rates increased linearly as solar radiation increased and decreased linearly as relative humidity increased. Changes in catch rates with time of day were explained almost entirely by the four weather variables, i.e. there was no evidence that intrinsic behavioural changes with time of day affected catch rates. The combined effects of the four weather variables accounted for 47·1 % of the between-day variation in trap catches. Trap catches that have been standardised, i.e. adjusted to a ‘ standard’ set of weather conditions, provide relative measures of population size which differ from absolute measures by a constant (unknown) scaling factor.


Author(s):  
V. Нolovan ◽  
V. Gerasimov ◽  
А. Нolovan ◽  
N. Maslich

Fighting in the Donbas, which has been going on for more than five years, shows that a skillful counter-battery fight is an important factor in achieving success in wars of this kind. Especially in conditions where for the known reasons the use of combat aviation is minimized. With the development of technical warfare, the task of servicing the counter-battery fight began to rely on radar stations (radar) to reconnaissance the positions of artillery, which in modern terms are called counter-battery radar. The principle of counter-battery radar is based on the detection of a target (artillery shell, mortar mine or rocket) in flight at an earlier stage and making several measurements of the coordinates of the current position of the ammunition. According to these data, the trajectory of the projectile's flight is calculated and, on the basis of its prolongation and extrapolation of measurements, the probable coordinates of the artillery, as well as the places of ammunition falling, are determined. In addition, the technical capabilities of radars of this class allow you to recognize the types and caliber of artillery systems, as well as to adjust the fire of your artillery. The main advantages of these radars are:  mobility (transportability);  inspection of large tracts of terrain over long distances;  the ability to obtain target's data in near real-time;  independence from time of day and weather conditions;  relatively high fighting efficiency. The purpose of the article is to determine the leading role and place of the counter-battery radar among other artillery instrumental reconnaissance tools, to compare the combat capabilities of modern counter-battery radars, armed with Ukrainian troops and some leading countries (USA, China, Russia), and are being developed and tested in Ukraine. The method of achieving this goal is a comparative analysis of the features of construction and combat capabilities of modern models of counter-battery radar in Ukraine and in other countries. As a result of the conducted analysis, the directions of further improvement of the radar armament, increasing the capabilities of existing and promising counter-battery radar samples were determined.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4846
Author(s):  
Dušan Marković ◽  
Dejan Vujičić ◽  
Snežana Tanasković ◽  
Borislav Đorđević ◽  
Siniša Ranđić ◽  
...  

The appearance of pest insects can lead to a loss in yield if farmers do not respond in a timely manner to suppress their spread. Occurrences and numbers of insects can be monitored through insect traps, which include their permanent touring and checking of their condition. Another more efficient way is to set up sensor devices with a camera at the traps that will photograph the traps and forward the images to the Internet, where the pest insect’s appearance will be predicted by image analysis. Weather conditions, temperature and relative humidity are the parameters that affect the appearance of some pests, such as Helicoverpa armigera. This paper presents a model of machine learning that can predict the appearance of insects during a season on a daily basis, taking into account the air temperature and relative humidity. Several machine learning algorithms for classification were applied and their accuracy for the prediction of insect occurrence was presented (up to 76.5%). Since the data used for testing were given in chronological order according to the days when the measurement was performed, the existing model was expanded to take into account the periods of three and five days. The extended method showed better accuracy of prediction and a lower percentage of false detections. In the case of a period of five days, the accuracy of the affected detections was 86.3%, while the percentage of false detections was 11%. The proposed model of machine learning can help farmers to detect the occurrence of pests and save the time and resources needed to check the fields.


2012 ◽  
Vol 610-613 ◽  
pp. 1033-1040
Author(s):  
Wei Dai ◽  
Jia Qi Gao ◽  
Bo Wang ◽  
Feng Ouyang

Effects of weather conditions including temperature, relative humidity, wind speed, wind and direction on PM2.5 were studied using statistical methods. PM2.5 samples were collected during the summer and the winter in a suburb of Shenzhen. Then, correlations, hypothesis test and statistical distribution of PM2.5 and meteorological data were analyzed with IBM SPSS predictive analytics software. Seasonal and daily variations of PM2.5 have been found and these mainly resulted from the weather effects.


2010 ◽  
Vol 28 (3) ◽  
pp. 495-509 ◽  
Author(s):  
Zuzana Husková ◽  
Zdeňka Vaňourková ◽  
Michaela Erbanová ◽  
Monika Thumová ◽  
Martin Opočenský ◽  
...  

2018 ◽  
Vol 7 (3.9) ◽  
pp. 42
Author(s):  
Norsafiah Norazman ◽  
Adi Irfan Che Ani ◽  
Nor Haslina Ja’afar ◽  
Muhamad Azry Khoiry

Indoor Air Quality (IAQ) is an essential matter in achieving students’ satisfaction for the learning process. Building’s orientation is a factor that may encourage sufficient natural ventilation for the classroom occupants. Inadequate ventilation is an issue for most existing classrooms. The purpose of this paper is to analyze the accuracy of natural ventilation in classrooms. Therefore, experimental on 20 classrooms has been conducted by using Multipurpose Meter at secondary school buildings in Malaysia. The findings indicated that the accuracy of natural ventilation testing was below the permissible limits throughout the hours monitored, thus this may cause potential health hazards to the students. Temperature and air flow rates were lower than 23 °C and 0.15 m/s respectively, it fulfilled the basic requirements as a standard learning environment. However, measurements taken showed the overall relative humidity (RH) in the classrooms can be categorized as acceptable with 40% to 70% range. On the basis of these findings, it is evident that naturally ventilated classrooms are important especially due to energy efficiency, whereas mechanical ventilation should only be installed as an alternative under extremely hot weather conditions.   


2007 ◽  
Vol 292 (2) ◽  
pp. H814-H819 ◽  
Author(s):  
Luis C. Matavelli ◽  
Xiaoyan Zhou ◽  
Jasmina Varagic ◽  
Dinko Susic ◽  
Edward D. Frohlich

We have previously shown that salt excess has adverse cardiac effects in spontaneously hypertensive rats (SHR), independent of its increased arterial pressure; however, the renal effects have not been reported. In the present study we evaluated the role of three levels of salt loading in SHR on renal function, systemic and renal hemodynamics, and glomerular dynamics. At 8 wk of age, rats were given a 4% ( n = 11), 6% ( n = 9), or 8% ( n = 11) salt-load diet for the ensuing 8 wk; control rats ( n = 11) received standard chow (0.6% NaCl). Rats had weekly 24-h proteinuria and albuminuria quantified. At the end of salt loading, all rats had systemic and renal hemodynamics measured; glomerular dynamics were specially studied by renal micropuncture in the control, 4% and 6% salt-loaded rats. Proteinuria and albuminuria progressively increased by the second week of salt loading in the 6% and 8% salt-loaded rats. Mean arterial pressure increased minimally, and glomerular filtration rate decreased in all salt-loaded rats. The 6% and 8% salt-loaded rats demonstrated decreased renal plasma flow and increased renal vascular resistance and serum creatinine concentration. Furthermore, 4% and 6% salt-loaded rats had diminished single-nephron plasma flow and increased afferent and efferent arteriolar resistances; glomerular hydrostatic pressure also increased in the 6% salt-loaded rats. In conclusion, dietary salt loading as low as 4% dramatically deteriorated renal function, renal hemodynamics, and glomerular dynamics in SHR independent of a minimal further increase in arterial pressure. These findings support the concept of a strong independent causal relationship between salt excess and cardiovascular and renal injury.


2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L.F. CIESLIK ◽  
R.A. VIDAL ◽  
A.B. MACHADO ◽  
M.M. TREZZI

ABSTRACT Grass weeds are common in summer crops and strongly decreases the grain yield of the common bean crop. The time of herbicide application influences the variability of environmental conditions and affects the product performance. The objectives of this work were to identify the time of fluazifop-p-butyl (fluazifop) application which gives best grass weed control in the common bean crop and to elucidate the environmental variables most important for the efficacy of this herbicide. Field experiments were conducted involving five application times (2 a.m., 6 a.m., 11 a.m., 4 p.m. and 9 p.m.) and five doses of fluazifop (80, 110, 140, 170 and 200 g ha-1), with additional no-herbicide control. At the time of the herbicide application it was determined the air temperature, relative humidity, the photosynthetically active radiation (PAR) and the leaf angle, whereas the weed control and the dry mass of the weed Urochloa plantaginea was assessed at 20 days after treatment (DAT). Efficacy on grass control with fluazifop was dependent on the herbicide dose and on the time of day that the product was applied. Spray at early morning hours (6 a.m.) showed better efficacy on weed control in relation to periods during warmer conditions of the day (11 a.m. and 4 p.m.). Nocturnal fluazifop application had better weed control when compared to herbicide sprayed in the afternoon. The air temperature, relative humidity and PAR were correlated to weed leaf angle, which correlated the most with fluazifop performance.


1999 ◽  
Vol 104 (6) ◽  
pp. 751-760 ◽  
Author(s):  
Vijaykumar R. Holla ◽  
Keiko Makita ◽  
Peter G. Zaphiropoulos ◽  
Jorge H. Capdevila

1999 ◽  
Vol 26 (5) ◽  
pp. 675 ◽  
Author(s):  
P. B. Whitaker ◽  
R. Shine

Encounters between humans and dangerously venomous snakes put both participants at serious risk, so the determinants of such encounters warrant attention. Pseudonaja textilis is a large fast-moving elapid snake responsible for most snakebite fatalities in Australia. As part of a broad ecological study of this species in agricultural land near Leeton, New South Wales, we set out to identify factors influencing the probability that a human walking in farmland would come into close proximity to a brownsnake. Over a three-year period, we walked regular transects to quantify the number and rate of snake encounters, and the proportion of snakes above ground that could be seen. The rate of encounters depended upon a series of factors, including season, time of day, habitat type, weather conditions (wind and air temperature) and shade (light v. dark) of the observers’ clothing. Interactions between factors were also important: for example, the effect of air temperature on encounter probability differed with season and snake gender, and the effect of the observers’ shade of clothing differed with cloud cover. Remarkably, even a highly-experienced observer actually saw <25% of the telemetrically monitored snakes that were known to be active (i.e. above ground) nearby. This result reflects the snakes’ ability to evade people and to escape detection, even in the flat and sparsely vegetated study area. The proportion of snakes that were visible was influenced by the same kinds of factors as described above. Most of the factors biasing encounter rates are readily interpretable from information on other facets of the species’ ecology, and knowledge of these factors may facilitate safer coexistence between snakes and people.


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