scholarly journals Behavioral adjustments to prior predation experience and food deprivation of a common cyprinid fish species vary between singletons and a group

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7236 ◽  
Author(s):  
Ya Wang ◽  
Shi-Jian Fu ◽  
Cheng Fu

Fish often undergo predation stress and food shortages in nature, and living in groups may provide the ecological benefits of decreased predator risk but the costs of increased food competition. The main aim of the present study was to test whether the behavioral response of qingbo (Spinibarbus sinensis) to predators and/or starvation differed between a singleton and a group. We measured the locomotor activity and distance to a predator and/or food item of prior predator-experienced, starved, double-treated and control qingbo; the qingbo were tested both as singletons and in a group (five individuals). Fish from all groups showed increased activity when tested collectively compared to individually. The predator-experienced fish showed decreased locomotor activity to predators as an antipredator strategy when tested as singletons; however, increased locomotor activity occurred when tested in a group, which might be partially due to the decreased predator risk when living in a group and thus higher levels of boldness. As expected, starvation elicited increased activity indicating increased foraging willingness when tested in a group; however, the difference between starved and normal-fed fish was no longer significant when they were tested as singletons, possibly due to the increased predation risk and decreased food competition when living individually and higher behavioral variation among individual fish than among those in a shoal. Compared with the control fish, the double-treated fish showed no difference in activity when tested both individually and collectively (except a slower speed when tested in a group). The reason for the results from the singletons might be an offset of the effect of predator exposure and starvation. The reason for this difference in the group might be due to the impaired body condition indicated by a slower swimming speed as a consequence of severe stress. The present study demonstrated that behavioral adjustment was closely related to the size of the group, which might be due to differences in the predation risk and food competition.

2013 ◽  
Vol 62 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Maria Mrówczyńska

Abstract The paper attempts to determine an optimum structure of a directional measurement and control network intended for investigating horizontal displacements. For this purpose it uses the notion of entropy as a logarithmical measure of probability of the state of a particular observation system. An optimum number of observations results from the difference of the entropy of the vector of parameters ΔHX̂ (x)corresponding to one extra observation. An increment of entropy interpreted as an increment of the amount of information about the state of the system determines the adoption or rejection of another extra observation to be carried out.


2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Tanti Jumaisyaroh Siregar

The purposes of this research were to know: the difference of improvement in self-regulated learning of students that given problem-based learning with students that given  direct learning. The type of this research is a quasi-experimental research by taking samples from the existing population. The variable of this research consist of independent variable that is problem based learning model while the dependent variable isself regulated learning of student.The population of this research is all students of SMP Swasta Ar-rahman Percut and the sample of this research is grade eight with taken sample two classes (experiment and control)  with total 60 students. The instrument of this research were: scale of self-regulated learning. Data that have been collected then analyzed and performed hypothesis testing by using T-test. Based of the results analysis, it showed that: improvment  of the students’ self-regulated learning that given problem-based learning was higher than the students’ ability that given direct learning His then, suggested that problem-based learning be used as an alternative for mathematic teacher to improved students’ ability in mathematical critical thinking and self-regulated learning.


2018 ◽  
Vol 28 (1) ◽  
pp. 137-141
Author(s):  
Petya Yordanova – Dinova

This paper explores the comparative analysis of the financial controlling, who is a result from the common controlling concept and the financial management. In the specialized literature, financial controlling is seen as an innovative approach to financial management. It is often presented as the most promising instrument of financial diagnostics. Generally speaking, financial controlling is seen as a process of managing the company`s assets which are valued in monetary measures. The difference between the financial management and the financial controlling is that the second covers all functions of management, analysis and control of finances, aiming at maximizing their effective use and increasing the value of the enterprise. Financial controlling is often seen as a function of the common practice of financial management. Its objective is to preserve the financial stability and financial sustainability of enterprises operating in a highly aggressive business environment.


2021 ◽  
Vol 9 (6) ◽  
pp. 1184
Author(s):  
Nomfusi Ntsobi ◽  
Morris Fanadzo ◽  
Marilize Le Roes-Hill ◽  
Felix Nchu

Globally, fungal inocula are being explored as agents for the optimization of composting processes. This research primarily evaluates the effects of inoculating organic vegetable heaps with the entomopathogenic fungus Clonostachys rosea f. catenula (Hypocreales) on the biophysicochemical properties of the end-product of composting. Six heaps of fresh cabbage (Brassica oleracea var. capitata) waste were inoculated with C. rosea f. catenula conidia and another six were not exposed to the fungus. The composted materials from the fungus- and control-treated heaps were subsequently used as a medium to cultivate tomatoes (Solanum lycopersicum). The biophysicochemical characteristics of the composted materials were also assessed after composting. In addition, the protective effect of the fungal inoculum against red spider mite (Tetranychus urticae) infestations in the tomatoes was evaluated through the determination of conidial colonization of the plant tissue and the number of plants infested by the insect. Furthermore, phytotoxicity tests were carried out post experiment. There were few significant variations (p < 0.05) in heap temperature or moisture level between treatments based on the weekly data. We found no significant differences in the levels of compost macronutrient and micronutrient constituents. Remarkably, the composted materials, when incorporated into a growth medium from fungus-treated heaps, induced a 100% endophytic tissue colonization in cultivated tomato plants. While fewer red spider mite infestations were observed in tomato plants grown in composted materials from fungus-treated heaps, the difference was not significant (χ2 = 0.96 and p = 0.32). The fungal treatment yielded composted materials that significantly (p < 0.05) enhanced tomato seed germination, and based on the phytotoxicity test, the composted samples from the heaps exposed to the C. rosea f. catenula inoculum were not toxic to tomato seeds and seedlings. In conclusion, this study showed that C. rosea f. catenula improved the quality of composted materials in terms of fungal endophytism and seed germination.


2021 ◽  
Vol 22 (13) ◽  
pp. 6792
Author(s):  
Dusan Todorovic ◽  
Marija Stojanovic ◽  
Ana Medic ◽  
Kristina Gopcevic ◽  
Slavica Mutavdzin ◽  
...  

The aim of this study was to investigate the effect of the application of homocysteine as well as its effect under the condition of aerobic physical activity on the activities of matrix metalloproteinases (MMP), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in cardiac tissue and on hepato-renal biochemical parameters in sera of rats. Male Wistar albino rats were divided into four groups (n = 10, per group): C: 0.9% NaCl 0.2 mL/day subcutaneous injection (s.c.); H: homocysteine 0.45 µmol/g b.w./day s.c.; CPA saline (0.9% NaCl 0.2 mL/day s.c.) and a program of physical activity on a treadmill; and HPA homocysteine (0.45 µmol/g b.w./day s.c.) and a program of physical activity on a treadmill. Subcutaneous injection of substances was applied 2 times a day at intervals of 8 h during the first two weeks of experimental protocol. Hcy level in serum was significantly higher in the HPA group compared to the CPA group (p < 0.05). Levels of glucose, proteins, albumin, and hepatorenal biomarkers were higher in active groups compared with the sedentary group. It was demonstrated that the increased activities of LDH (mainly caused by higher activity of isoform LDH2) and mMDH were found under the condition of homocysteine-treated rats plus aerobic physical activity. Independent application of homocysteine did not lead to these changes. Physical activity leads to activation of MMP-2 isoform and to increased activity of MMP-9 isoform in both homocysteine-treated and control rats.


2021 ◽  
Vol 13 (2) ◽  
pp. 804
Author(s):  
Jean Dubé ◽  
Maha AbdelHalim ◽  
Nicolas Devaux

Many applications have relied on the hedonic pricing model (HPM) to measure the willingness-to-pay (WTP) for urban externalities and natural disasters. The classic HPM regresses housing price on a complete list of attributes/characteristics that include spatial or environmental amenities (or disamenities), such as floods, to retrieve the gradients of the market (marginal) WTP for such externalities. The aim of this paper is to propose an innovative methodological framework that extends the causal relations based on a spatial matching difference-in-differences (SM-DID) estimator, and which attempts to calculate the difference between sale price for similar goods within “treated” and “control” groups. To demonstrate the potential of the proposed spatial matching method, the researchers present an empirical investigation based on the case of a flood event recorded in the city of Laval (Québec, Canada) in 1998, using information on transactions occurring between 1995 and 2001. The research results show that the impact of flooding brings a negative premium on the housing price of about 20,000$ Canadian (CAN).


Author(s):  
Surinder Kaur M. S. Pada ◽  
Poh Lishi ◽  
Kim Sim Ng ◽  
Sarathamani Rethenam ◽  
Lilibeth Silagan Alenton ◽  
...  

Abstract Background Computerisation of various processes in hospitals and reliance on electronic devices raises the concern of contamination of these devices from the patient environment. We undertook this study to determine if an attached hand hygiene device that unlocks the screen of a computer on wheels (COW) on usage can be effective in decreasing the microbiological burden on computer keyboards. Methods An electronic hand sanitizer was integrated onto the COW. A prospective cohort study with a crossover design involving 2 control and 2 intervention wards was used. The study end point was the number of colony forming units found on the keyboards. Bacteria were classified into 4 main groups; pathogenic, skin flora, from the environment or those thought to be commensals in healthy individuals. We then used a mixed effects model for the statistical analysis to determine if there were any differences before and after the intervention. Results Thirty-nine keyboards were swabbed at baseline, day 7 and 14, with 234 keyboards cultured, colony forming units (CFUs) counted and organisms isolated. By mixed model analysis, the difference of mean bacteria count between intervention and control for week 1 was 32.74 (− 32.74, CI − 94.29 to 28.75, p = 0.29), for week 2 by 155.86 (− 155.86, CI − 227.45 to − 83.53, p < 0.0001), and after the 2-week period by 157.04 (− 157.04, CI − 231.53 to − 82.67, p < 0.0001). In the sub-analysis, there were significant differences of pathogenic bacteria counts for the Intervention as compared to the Control in contrast with commensal counts. Conclusion A hand hygiene device attached to a COW may be effective in decreasing the microbiological burden on computer keyboards.


Author(s):  
Kirsty Duncanson ◽  
Catriona Elder ◽  
Murray Pratt

Film in Australia, as with many other nations, is often seen as an important cultural medium where national stories about belonging and identity can be (re)produced in pleasurable and, at times, complicated ways. One such film is Ray Lawrence’s Lantana. Although striking a chord in Australia as a good film about ‘ basically good people’, people that rang ‘brilliantly’ true (Lantana DVD 2002), this paper argues that, at the same time as it produces a fantasy of a ‘good’ Australia, the film also conducts a regulation of what constitutes Australianness. In many ways the imaginary of Australia offered in this film, to its contemporary, urban, professional and intellectual elite audience, still draws on and (re)produces a vision of an Australian community that uses the same narrative frameworks of protection and control as the cruder discourses of ‘white Australia’ offered to an earlier generation of cinema-goers. This film’s central motif of the lantana bush, the out of control weed, that is known as both foreign and local is here emblematic of tensions about belonging, place and otherness. Yet while, within the film’s knowingly reflexive purview any remaining potential for racism is understood and itself under control – we know how to be good mutliculturalists –it is the trope of sexuality in Lantana that provides the real sense of edginess and anxiety about belonging. It is in this arena that the film sets up an idea of danger and –less self-consciously, and in the end more aggressively – marks out who is and who is not part of the community. In this context the motif of lantana signals an ambivalence about difference and the exotic. Lantana is both desirable because of the difference in its attractive Latin looks and repulsive or feared because of other qualities inherent within its difference: a refusal to behave and a propensity to get out-of control, spread and potentially take over. The film here explores desire for a taste of the other (a gay man, a newly separated woman, a Latin dance teacher). However, these fantasies are in the end emphatically shut down as the film ends by producing a vision of subtly normalised hetero, mono, familial (though not necessarily happy) forms of desiring, loving and reproducing in contemporary Australia.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Zalika Klemenc-Ketis ◽  
Branka Cagran ◽  
Dejan Dinevski

Introduction. A “virtual patient” is defined as a computer program which simulates real patients’ cases. The aim of this study was to determine whether the inclusion of virtual patients affects the level of factual knowledge of family medicine students at the undergraduate level. Methods. This was a case-controlled prospective study. The students were randomly divided into experimental (EG: N=51) and control (CG: N=48) groups. The students in the EG were asked to practice diagnosis using virtual patients instead of the paper-based clinical cases which were solved by the students in the CG. The main observed variable in the study was knowledge of family medicine, determined by 50 multiple choice questions (MCQs) about knowledge of family medicine. Results. There were no statistically significant differences in the groups’ initial knowledge. At the final assessment of knowledge, there were no statistically significant differences between the groups, but there was a statistically significant difference between their initial and final knowledge. Conclusions. The study showed that adding virtual patient cases to the curriculum, instead of paper clinical cases, did not affect the level of factual knowledge about family medicine. Virtual patients can be used, but a significant educational outcome is not expected.


1969 ◽  
Vol 62 (2) ◽  
pp. 367-384 ◽  
Author(s):  
A. M. Sackler ◽  
A. S. Weltman ◽  
R. Schwartz ◽  
P. Steinglass

ABSTRACT This report was designed to determine combined effects of maternal endocrine imbalances and abnormal behaviour due to prolonged isolation stress of female mice on the behaviour, developmental growth rate and endocrine function of their offspring. Sixty female albino mice averaging 19 g were divided equally into isolated and control groups. The isolated females were housed singly; control females were maintained in groups of 2 mice per cage. After observation of behavioural and physiological effects characteristic of isolation stress in the test mice, all isolated and control mice were mated after a 6½ month experimental, isolation period. No differences were observed in fertility and fecundity of the two groups of mothers. Analyses of developmental growth rates of the litters of the isolated versus control mothers showed significantly lower body weights in the test offspring at 3 and 4 weeks of age. The body weights of the female offspring remained significantly lower from the 4th to 11th weeks. The effects on the body weights of the male offspring declined and were no longer statistically significant at the 5th to 11 weeks. Locomotor activity at 4½ and 8 weeks of age was markedly or significantly higher in the male and female mice from isolated mothers. Tail-blood samples taken prior to autopsy at 5 and 11 weeks of age revealed significant decreases in the total leukocyte and eosinophil counts of both sexes. At the two ages, the absolute and relative spleen and thymus weights of the male and female offspring were markedly and/or significantly lower than the values observed in counterpart young from control females. Significant decreases were also observed in the absolute gonadal organ weights of both sexes at 11 weeks of age. The various data indicated inhibited growth rates, heightened locomotor activity and evasiveness, as well as evidence of increased adrenocortical function in the offspring from test mothers. The gonadal weight decreases suggested retarded gonadal development. Further studies using split-litter techniques are required to differentiate the effects of prenatal endocrine imbalances versus postnatal maternal influence (i. e., nursing care) on the offspring.


Sign in / Sign up

Export Citation Format

Share Document