Social Facilitation and Digging Behavior in the Beetle Odontotaenius floridanus Schuster (Coleoptera: Passalidae)

2007 ◽  
Vol 42 (4) ◽  
pp. 525-532 ◽  
Author(s):  
F. Punzo

Laboratory studies assessed the effect of group size on egg-carrying behavior and walking speed of adults of the subsocial beetle, Odontotaenius floridanus Schuster (Coleoptera: Passalidae). Adult males tested solo carried significantly fewer eggs per individual when compared with males tested in groups of 4 and 8 individuals. Similarly, adult males and females in groups of 4 and 8 individuals exhibited significantly faster walking speeds when tested in a linear runway as compared with adults tested alone. There was no significant difference in the number of eggs carried or walking speed between beetles tested in groups of 4 or 8 individuals. This represents the first demonstration of social facilitation in passalid beetles. The adaptive significance of social facilitation in insects is discussed.

1987 ◽  
Vol 114 (2) ◽  
pp. 178-184 ◽  
Author(s):  
Hajime Watanobe ◽  
Kazuo Takebe

Abstract. The cimetidine-induced plasma Prl response was examined in rats of both sexes. First, 10 week old intact adult males and females (dioestrous) were compared. There was no significant difference in the Prl response to cimetidine between the two groups, despite the fact that in adult females the anterior pituitary Prl content was 4 times greater than in males. Second, the effect of gonadal state in adult age on the Prl response to cimetidine was examined in both sexes. In male rats, gonadectomy at the age of 6 weeks significantly reduced the plasma Prl response as well as the pituitary Prl content, both of which were sufficiently restored by testosterone replacement. However, in females, neither gonadectomy at the age of 6 weeks nor subsequent oestradiol replacement affected the Prl response to cimetidine, despite the fact that gonadectomy significantly reduced and oestradiol treatment significantly enhanced the pituitary Prl content. Third, possible permanent effects of the postnatal gonadal milieu on the cimetidine-induced Prl response and the pituitary Prl content were examined in both sexes by castration at varying postnatal ages. The ratio of plasma Prl response to pituitary Prl content was similar in all castrated males. In females, however, the ratio decreased with increasing castration age. In conclusion, the mechanism of cimetidine-induced Prl release is less sex-dependent than are the mechanisms of Prl release by other Prl secretagogues. First, this may be due to a minor role of oestrogen in females in determining the Prl response to cimetidine. Second, the postnatal ovarian secretions may exert a permanent inhibition of the development of the cimetidine-mobilized anterior pituitary Prl pool.


1987 ◽  
Vol 8 (1) ◽  
pp. 13-17 ◽  
Author(s):  
S.P. Gittins

AbstractThere was no significant difference between the number of food items obtained by stomach-flushing toads caught in pitfall traps and from the dissection of corpses found on nearby roads. The frequencies of the different food categories were similar using the two methods. 97 % of the toads entering the pond in the spring had not recently fed, whereas 25% of toads leaving the pond had started to feed. Sloughed skin was found in 7% of stomachs. Vegetable matter was found in 15% of stomachs and inorganic matter in 6% of stomachs. The diet of the toad was found to be very varied, and the main food items were beetles, collembolans, millipedes, harvestmen and spiders. The diets of males, females and young toads were very similar, and only slight changes in diet were observed throughout the year. The size of food items ranged from 1 mm to 40 mm with most around 7 mm. There was no significant relationship between the size of the food item and the size of the toad for adult males and females, but there was for juveniles.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Vida Hojati ◽  
Reza Babaei Savasari

The Caspian bent-toed gecko,Tenuidactylus caspius, is one of the most common nocturnal lizards of Iran with widespread distribution especially in the northern provinces. This research was done in order to study the diet and sexual dimorphism of this species in Sari County from 5 May to 20 October. During this research, 40 specimens of them including 20 males and 20 females were studied for diet and 140 specimens including 70 adult males and 70 adult females were studied for sexual dimorphism. Prey items identified were insects that belong to 15 species of 8 families and 6 orders. The most common prey items wereCulex pipiensandMusca domestica. There is no significant difference between diets of males and females. Results show that the adult males in addition of having the apparent femoral and preanal pores are heavier than females and have larger body, head, and tail length.


2010 ◽  
Vol 124 (12) ◽  
pp. 1251-1256 ◽  
Author(s):  
S Elwany ◽  
A Medanni ◽  
M Eid ◽  
A Aly ◽  
A El-Daly ◽  
...  

AbstractObjective:To establish normative dimensions for the depth of the olfactory fossa, the length and angulation of the lateral lamella of the cribriform plate, and the height of the ethmoid roof, in adult males and females.Design:The study assessed 300 high resolution, multislice computed tomography scans of the paranasal sinuses, which were evaluated using Merge Efilm software (version 2.0.0, build 37).Results:According to the original Keros classification, the type II olfactory fossa was the commonest type in men (66.7 per cent), while the type I fossa was commonest in women (53 per cent). A difference of 3 mm or more between the depths of the right and left olfactory fossae was present in 11 per cent of men and 2 per cent of women. The lateral lamella of the cribriform plate was significantly shorter and less oblique in men than in women. The length of the lateral lamella was greater anteriorly than posteriorly in both sexes. There was a statistically significant difference between the angle of the lateral lamellae, comparing right and left sides. The ethmoid roof was lower in women than men.Conclusion:The observed differences between men and women and between the right and left sides are of surgical importance, and should alert surgeons to the need for thorough, systematic pre-operative evaluation of computed tomography scans.


2020 ◽  
Vol 10 (21) ◽  
pp. 7498
Author(s):  
Chi-Wen Lung ◽  
Fu-Lien Wu ◽  
Keying Zhang ◽  
Ben-Yi Liau ◽  
Runnell Townsend ◽  
...  

Exercise has been demonstrated to improve health in people with diabetes. However, exercise may increase risk for foot ulcers because of increased plantar pressure during most weight-bearing physical activities. To date, there is no study investigating the effect of various walking speeds and durations (i.e., the most common form of exercise in daily living) on the plantar foot. The objective of this study was to investigate the effect of various walking intensities on plantar tissue stiffness. A 3 × 2 factorial design, including three walking speeds (1.8, 3.6 and 5.4 mph) and two durations (10 and 20 min), was tested in 12 healthy participants. B-mode and elastographic ultrasound images were measured from the first metatarsal head to quantify plantar tissue stiffness after walking. Two-way ANOVA was used to examine the results. Our results showed that the walking speed factor caused a significant main effect of planar stiffness of the superficial layers (p = 0.007 and 0.003, respectively). However, the walking duration factor did not significantly affect the plantar stiffness. There was no interaction between the speed and duration factors on plantar tissue stiffness. Regarding the walking speed effect, there was a significant difference in the plantar stiffness between 1.8 and 3.6 mph (56.8 ± 0.8% vs. 53.6 ± 0.9%, p = 0.017) under 20 min walking duration. This finding is significant because moderate-to-fast walking speed (3.6 mph) can decrease plantar stiffness compared to slow walking speed (1.8 mph). This study suggests people at risk for foot ulcers walk at a preferred or fast speed (3.6 mph) rather than walk slowly (1.8 mph).


1988 ◽  
Vol 7 (3) ◽  
pp. 113-121
Author(s):  
A. C. Kok ◽  
O. B. Kok

Cultivated crops such as maize, sunflower and wheat are the dominant food component of rock pigeons near urban areas, but in more remote rural surroundings natural vegetation forms an important part of the diet. No significant difference is apparent in the overall dietary composition of the respective sex and age groups. Likewise, the number and size of separate food items in the crops of adult males and females are remarkably similar. The average crop mass of both sexes is significantly higher in the late afternoon than in the early morning. The conspicuous seasonal variation in crop mass is apparently related to the relative availability of the food supply. Despite a large degree of dietary overlap, direct competition between rock and feral pigeons is limited to a minimum.


2009 ◽  
Vol 69 (1) ◽  
pp. 137-142 ◽  
Author(s):  
JC. Niemeyer ◽  
VC. Santos ◽  
PB. Araújo ◽  
EM. da Silva

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.


2014 ◽  
Vol 39 (2) ◽  
pp. 120-125 ◽  
Author(s):  
Alan R De Asha ◽  
John G Buckley

Background: Minimum toe clearance is a critical gait event because it coincides with peak forward velocity of the swing foot, and thus, there is an increased risk of tripping and falling. Trans-tibial amputees have increased risk of tripping compared to able-bodied individuals. Assessment of toe clearance during gait is thus clinically relevant. In able-bodied gait, minimum toe clearance increases with faster walking speeds, and it is widely reported that there is synchronicity between when peak swing-foot velocity and minimum toe clearance occur. There are no such studies involving lower-limb amputees. Objectives: To determine the effects of walking speed on minimum toe clearance and on the temporal relationship between clearance and peak swing-foot velocity in unilateral trans-tibial amputees. Study design: Cross-sectional. Methods: A total of 10 trans-tibial participants walked at slow, customary and fast speeds. Minimum toe clearance and the timings of minimum toe clearance and peak swing-foot velocity were determined and compared between intact and prosthetic sides. Results: Minimum toe clearance was reduced on the prosthetic side and, unlike on the intact side, did not increase with walking speed increase. Peak swing-foot velocity consistently occurred (~0.014 s) after point of minimum toe clearance on both limbs across all walking speeds, but there was no significant difference in the toe–ground clearance between the two events. Conclusion: The absence of speed related increases in minimum toe clearance on the prosthetic side suggests that speed related modulation of toe clearance for an intact limb typically occurs at the swing-limb ankle. The temporal consistency between peak foot velocity and minimum toe clearance on each limb suggests that swing-phase inter-segmental coordination is unaffected by trans-tibial amputation. Clinical relevance The lack of increase in minimum toe clearance on the prosthetic side at higher walking speeds may potentially increase risk of tripping. Findings indicate that determining the instant of peak swing-foot velocity will also consistently identify when/where minimum toe clearance occurs.


1973 ◽  
Vol 51 (12) ◽  
pp. 1293-1297 ◽  
Author(s):  
W. R. Siegfried

The food and feeding habits of adult and juvenile ruddy ducks (Oxyura jamaicensis) in southwestern Manitoba were studied during June–August 1971. Animal material predominated in the diets of the birds. The basic diets of adult males and females, as well as ducklings of all ages, were similar. Larval and pupal midges (Tendipedidae), especially Chironomus, constituted the main food item. The quantity of grit in the gizzards increased with the age of the ducklings. There was no significant difference between the average quantities of grit retained by male and female adult birds. Ruddy ducks, of all ages, forage almost exclusively by diving and straining food organisms from the soft muddy ooze on the bottoms of ponds. Foraging ruddy ducks appear to select areas relatively rich in midge larvae.


2017 ◽  
Vol 5 (1) ◽  
pp. 30
Author(s):  
Najla Mohamed Abu Shaala ◽  
Syaizwan Zahmir Zulkifli ◽  
Ahmad Ismail ◽  
Mohammed Noor Amal Azmai ◽  
Ferdaus Mohamat-Yusuff ◽  
...  

Elevation of tributyltin (TBT) concentration in marine environment could affect targeted and non-targeted organisms at any lifestage. The present study aimed to determine median lethal concentration (LC50) and morphological effects of tributyltin chloride (TBTCl) on adult males and females of brine shrimp (Artemia salina). The adult males and females of A. salina were exposed to different concentration of TBTCl. Morphological condition of every A. salina individuals were observed under a microscope. Results showed the LC50 of TBTCl among adult males of A. salina was 146.99 ng.L-1 and for the females was 94.72 ng.L-1, respectively. The LC50 of TBTCl was significantly different among different sexes. There was also a significant difference in some morphological characters of males and females exposed to different TBTCl concentrations. These morphological changes include their total length, head width, abdominal width, and tail width after the 24hr exposure to TBTCl. These results suggested that suspensions of the TBTCl were toxic to Artemia, most likely due to the formation of benign TBTCl aggregates in water. However, the mortality increased with extended exposure to 24hr. Highest mortality occurred at 200 ng.L-1 TBTCl; 43.33% for male and 90% for female (LC50<150 ng.L-1) for both. Depended on this the female was more sensitive for TBTCl toxicity test when compared to male. These effects were attributed to changes in morphological characteristics of the body A. salina.


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