scholarly journals Behavioral Responses to 'Alarm Odors' In Potentially Invasive and Non-invasive Crayfish Species from Aquaculture Ponds

Behaviour ◽  
2004 ◽  
Vol 141 (6) ◽  
pp. 691-702 ◽  
Author(s):  
William Daniels ◽  
Francesca Gherardi ◽  
Patrizia Acquistapace

AbstractTwo North American crayfish species, the Eastern white river crayfish, Procambarus acutus acutus, and the red swamp crayfish, P. clarkii, were studied in the laboratory for their responses to food odors and to cues released by injured conspecifics and heterospecifics. The two species differ in that only P. clarkii is known to behave as an invasive species. All the test individuals were collected from aquaculture research ponds, in which they had had no prior contact with the other species and predation risks, excluding cannibalism, were reduced. The experimental design consisted in subjecting 20 crayfish per species to (1) a 3-min control phase after the injection of 20 ml of water and (2) a 3-min test phase after the injection of 20 ml of one of three test solutions (food odor, conspecific odor plus food odor, heterospecific odor plus food odor). We found that the two species differ on one hand for their background behavior and on the other for the intensity and quality of their responses to the three types of cues. Firstly, P. clarkii appeared more active than P. acutus acutus during the control phase and responded in a stronger fashion to the injection of the solutions. Secondly, we recorded an increased locomotion in P. acutus acutus with food and heterospecific cues (by moving crayfish maximize the chance of finding food), but not with conspecific odors (by not moving, crayfish reduce their exposure to visual predators). To the contrary, at the injection of the three test solutions P. clarkii displayed clear feeding-related activities (although less intense with conspecific odors) as opposed to the danger reactions shown in a previous study on individuals from a naturalized population of the same species. This result suggests that crayfish reared in an environment where predation risks are reduced (e. g. in aquaculture ponds) may respond differently to cues that in other, more risky habitats inform of a danger.

2004 ◽  
Vol 82 (12) ◽  
pp. 1923-1932 ◽  
Author(s):  
Francesca Gherardi ◽  
William H Daniels

Several crayfish species behave as biological invaders. Their establishment in an area has frequently been accompanied by the reduction or elimination of indigenous species. A laboratory study was designed to investigate whether the invasive crayfish Procambarus clarkii (Girard, 1852) is dominant over the indigenous (to Delaware) crayfish Procambarus acutus acutus (Girard, 1852) in either the absence or the presence of a shelter as a limited resource. As expected, we found that P. clarkii is more aggressive than the similarly sized P. a. acutus, thus confirming previous studies that demonstrated an inherent dominance of the invasive over the indigenous crayfish. We then hypothesized that species showing a lower preference for an offered shelter (P. clarkii) should be less motivated to defend it. To the contrary, in a competitive context P. clarkii excluded P. a. acutus from the shelter but did not use the resource. Caution must be used in extrapolating these laboratory studies to the field, and future studies should analyze multiple factors, including the autoecology of the two species and their reproductive potential and recruitment patterns. However, our results might help in highlighting the risks for freshwater biodiversity created by the uncontrolled translocations of P. clarkii and other similar invasive species.


2021 ◽  
Vol 32 (8) ◽  
pp. 312-316
Author(s):  
Paul Silverston

The pandemic has led to an increase in the use of pulse oximetry to assess and manage patients with COVID-19 disease. Paul Silverston explains the principles of pulse oximetry and the factors that can affect the reliability and accuracy of readings Pulse oximetry is performed to detect and quantify the degree of hypoxia in patients with respiratory symptoms and illnesses, including patients with COVID-19 disease. Pulse oximeters are non-invasive, simple to use and inexpensive, but it is important to know how to interpret the readings in the context of the patient's symptoms and the other clinical findings. In COVID-19 disease, very small differences in the oxygen saturation reading result in significant differences in the way that the patient is managed, so it is important to be aware of the factors that can affect these readings. It is also important to appreciate that a low reading in a patient with suspected or confirmed COVID-19 disease may be the result of another disease process.


MedPharmRes ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 46-51
Author(s):  
Chau Vu Bao Nguyen ◽  
Tinh Thu Nguyen ◽  
Tam Thi Thanh Pham ◽  
Sen Thi Hong Lam ◽  
Le An Pham ◽  
...  

Background: The use of non-invasive ventilation (NIV) in preterm infants is becoming increasingly common. The use of cannula in NIV can cause ulceration of the nasal bridge with the current practices using the thin foam patches. This study aims to evaluate the effectiveness of hydrocolloid nasal dressing pads in preventing nasal ulceration comparing to that of the thin foam patches. Methods: A prospective cohort study using hydrocolloid dressing pads (1 November to 30 April 2020) was compared to that of a historical control group using thin foam dressing (1 April to 15 October 2019) to evaluate the effectiveness of hydrocolloid dressing pads. All participants were preterm infants (less than 37 weeks of gestational age) and used nasal cannula NIV at the Department of Neonatal Intensive Care (NICU), Children's Hospital 1. Results: 71 infants used hydrocolloid dressing pads, and 42 used ordinary thin foam nasal dressings. In the hydrocolloid dressings group, two infants (2.8%) had nasal ulcers; among them, one was mild, and the other was moderate. In comparison, ten infants (23.8%) using thin foam dressings developed ulcers, of which seven were mild, two were moderate, and one was severe. Using hydrocolloid nasal dressings significantly reduced nasal ulceration compared to thin foam dressings (OR = 0.09, 95%CI = 0.02 – 0.45). Conclusion: Using hydrocolloid nasal dressings for preterm infants on nasal cannula NIV significantly reduced nasal ulceration compared to ordinary thin foam dressings.


Author(s):  
Sergio G. Torres Cedillo ◽  
Philip Bonello ◽  
Ghaith Ghanim Al-Ghazal ◽  
Jacinto Cortés Pérez ◽  
Alberto Reyes Solis

Modern aero-engine structures typically have at least two nested rotors mounted within a flexible casing via squeeze-film damper (SFD) bearings. The inaccessibility of the HP rotor under operational conditions motivates the use of a non-invasive inverse problem procedure for identifying the unbalance. Such an inverse problem requires prior knowledge of the structure and measurements of the vibrations at the casing. Recent work by the authors reported a non-invasive inverse method for the balancing of rotordynamic systems with nonlinear squeeze-film damper (SFD) bearings, which overcomes several limitations of earlier works. However, it was not applied to a common practical configuration wherein the HP rotor is mounted on the casing via just one weak linear connection (retainer spring), with the other connections being highly nonlinear SFDs. The analysis of the present paper considers such a system. It explores the influence of the condition number and how it is affected as the number of sensors and/or measurement speeds is increased. The results show that increasing the number of measurement speeds has a far more significant impact on the conditioning of the problem than increasing the number of sensors. The balancing effectiveness is reasonably good under practical noise level conditions, but significantly lower than obtained for the previously considered simpler configurations.


2019 ◽  
Vol 72 (1) ◽  
pp. 64-67
Author(s):  
Olena О. Taranovska ◽  
Volodymyr К. Likhachov ◽  
Ludmyla М. Dobrovolska ◽  
Oleg G. Makarov ◽  
Yanina V. Shymanska

Introduction: Detection and treatment of chronic endometritis (CE) is clinically significant, though involves intrauterine intervention to collect endometrium. The aim: To estimate the possibility to use fertility α2-microglobulin (FAMG) as the marker of the high risk for CE. Materials and methods: 70 women with CE who were planning pregnancy were tested for FAMG in menstrual blood. 40 of them received treatment of CE. The other 30 women refused from the proposed treatment. The control group involved 30 women who had neither CE nor luteal phase deficiency (LPD). Additional group (20 women) had LPD without CE. Results: The decrease of FAMG by 2.4 times was noted in women with CE (16.3 ± 3.9 μg/ml against 39.8 ± 8.3 μg/ml in the controls). In LPD the index was 5.6 times lower. After treatment the level of FAMG was increasing. Conclusions: The decrease of the amount of FAMG in menstrual blood is specific for women both with CE and LPD. Detection of abnormally low rates of FAMG in all women with CE enables, with the exception of absolute hypoprogesteronemia and LPD, using it as a simple method of estimation of the functional state of endometrium. Its application can be very useful both for non-invasive diagnosis of CE and subsequent evaluation of treatment of this pathology.


2019 ◽  
Author(s):  
James D. Howard ◽  
Rachel Reynolds ◽  
Devyn E. Smith ◽  
Joel L. Voss ◽  
Geoffrey Schoenbaum ◽  
...  

ABSTRACTOutcome-guided behavior requires knowledge about the current value of expected outcomes. Such behavior can be isolated in the reinforcer devaluation task, which assesses the ability to infer the current value of rewards after devaluation. Animal lesion studies demonstrate that orbitofrontal cortex (OFC) is necessary for normal behavior in this task, but a causal role for human OFC in outcome-guided behavior has not been established. Here we used sham-controlled non-invasive continuous theta-burst stimulation (cTBS) to temporarily disrupt human OFC network activity prior to devaluation of food odor rewards in a between-subjects design. Subjects in the sham group appropriately avoided Pavlovian cues associated with devalued food odors. However, subjects in the stimulation group persistently chose those cues, even though devaluation of food odors themselves was unaffected by cTBS. This behavioral impairment was mirrored in changes in resting-stated functional magnetic resonance imaging (rs-fMRI) activity, such that subjects in the stimulation group exhibited reduced global OFC network connectivity after cTBS, and the magnitude of this reduction was correlated with choices after devaluation. These findings demonstrate the feasibility of indirectly targeting the human OFC with non-invasive cTBS, and indicate that OFC is specifically required for inferring the value of expected outcomes.


2013 ◽  
pp. 530-549
Author(s):  
Ganesh Naik ◽  
Dinesh Kant Kumar ◽  
Sridhar Arjunan

In recent times there is an urgent need for a simple yet robust system to identify natural hand actions and gestures for controlling prostheses and other computer assisted devices. Surface Electromyogram (sEMG) is a non-invasive measure of the muscle activities but is not reliable because there are multiple simultaneously active muscles. This research first establishes the conditions for the applicability of Independent Component Analysis (ICA) pattern recognition techniques for sEMG. Shortcomings related to order and magnitude ambiguity have been identified and a mitigation strategy has been developed by using a set of unmixing matrix and neural network weight matrix corresponding to the specific user. The experimental results demonstrate a marked improvement in the accuracy. The other advantages of this system are that it is suitable for real time operations and it is easy to train by a lay user.


Author(s):  
Ganesh Naik ◽  
Dinesh Kant Kumar ◽  
Sridhar Arjunan

In recent times there is an urgent need for a simple yet robust system to identify natural hand actions and gestures for controlling prostheses and other computer assisted devices. Surface Electromyogram (sEMG) is a non-invasive measure of the muscle activities but is not reliable because there are multiple simultaneously active muscles. This research first establishes the conditions for the applicability of Independent Component Analysis (ICA) pattern recognition techniques for sEMG. Shortcomings related to order and magnitude ambiguity have been identified and a mitigation strategy has been developed by using a set of unmixing matrix and neural network weight matrix corresponding to the specific user. The experimental results demonstrate a marked improvement in the accuracy. The other advantages of this system are that it is suitable for real time operations and it is easy to train by a lay user.


2020 ◽  
Vol 50 (15) ◽  
pp. 2465-2486
Author(s):  
Marieke J. Begemann ◽  
Bodyl A. Brand ◽  
Branislava Ćurčić-Blake ◽  
André Aleman ◽  
Iris E. Sommer

AbstractBackgroundCognition is commonly affected in brain disorders. Non-invasive brain stimulation (NIBS) may have procognitive effects, with high tolerability. This meta-analysis evaluates the efficacy of transcranial magnetic stimulation (TMS) and transcranial Direct Current Stimulation (tDCS) in improving cognition, in schizophrenia, depression, dementia, Parkinson's disease, stroke, traumatic brain injury, and multiple sclerosis.MethodsA PRISMA systematic search was conducted for randomized controlled trials. Hedges' g was used to quantify effect sizes (ES) for changes in cognition after TMS/tDCS v. sham. As different cognitive functions may have unequal susceptibility to TMS/tDCS, we separately evaluated the effects on: attention/vigilance, working memory, executive functioning, processing speed, verbal fluency, verbal learning, and social cognition.ResultsWe included 82 studies (n = 2784). For working memory, both TMS (ES = 0.17, p = 0.015) and tDCS (ES = 0.17, p = 0.021) showed small but significant effects. Age positively moderated the effect of TMS. TDCS was superior to sham for attention/vigilance (ES = 0.20, p = 0.020). These significant effects did not differ across the type of brain disorder. Results were not significant for the other five cognitive domains.ConclusionsOur results revealed that both TMS and tDCS elicit a small trans-diagnostic effect on working memory, tDCS also improved attention/vigilance across diagnoses. Effects on the other domains were not significant. Observed ES were small, yet even slight cognitive improvements may facilitate daily functioning. While NIBS can be a well-tolerated treatment, its effects appear domain specific and should be applied only for realistic indications (i.e. to induce a small improvement in working memory or attention).


Author(s):  
G J Verkerke ◽  
H Schraffordt Koops ◽  
R P H Veth ◽  
J Oldhoff ◽  
H K L Nielsen ◽  
...  

A malignant tumour may develop around the knee joint of a child. In the majority of cases it will then be necessary to resect the involved bone with adjacent tissue. A joint team of Groningen University Hospital and University of Twente is currently working on the project of developing a modular endoprosthetic system to bridge the defect resulting from the resection. Since the other, normal, leg continues to grow, the endoprosthetic system will have to include an element the length of which can be adjusted non-invasively. The main conditions to be met by the lengthening element are non-invasive continuous adjustability and a maximum total lengthening of 114 mm. This was achieved by using an external magnetic field. Animal experiments showed that the lengthening element worked well, although moisture infiltrated the telescopic tubes and the lengthening element was covered by proliferating bone at an early stage. Also, the necessary magnetic field proved to be larger than calculated. In a revised design, these problems are resolved. In vitro tests show that the new lengthening element meets all requirements.


Sign in / Sign up

Export Citation Format

Share Document