Activity of tabanids (Insecta: Diptera: Tabanidae) attacking the reptiles Caiman crocodilus (Linn.) (Alligatoridae) and Eunectes murinus (Linn.) (Boidae), in the central Amazon, Brazil.
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Tabanid females are better known as hematophagous on man and other mammals, and linked to mechanical transmission of parasites. The association between tabanids and reptiles is poorly known, but has been gaining more corroboration through experiments and occasional observation in the tropics. The present study was conducted at a military base (CIGS/BI-2), situated 54 km from Manaus, Amazonas, in a small stream in a clearing (02 degrees 45'33"S; 59 degrees 51'03"W). Observations were made monthly, from April 1997 to March 1998, during two consecutive days. At the same time, other vertebrate animals were offered, including humans. However in this paper only data obtained on a common caiman, Caiman crocodilus (Linn.), and an anaconda, Eunectes murinus (Linn.), in diurnal observations from 05:30 a.m. to 18:30 p.m., will be discussed. A total of 254 tabanid specimens were collected, 40 from the anaconda and 214 from the caiman. Four tabanid species were recorded on these two reptiles: Stenotabanus cretatus Fairchild, S. bequaerti Rafael et al., Phaeotabanus nigriflavus (Krober) and Tabanus occidentalis Linn. Diurnal activities showed species-specific patterns. The first three species occurred only in the dry season. T. occidentalis occurred during the whole observation period, and with increased frequency at the end of the dry season. We observed preferences for body area and related behavior of the host. Observations on the attack of tabanids on one dead caiman are also presented. (+info)
Phorcotabanus cinereus (Wiedemann, 1821) (Diptera, Tabanidae), an ornithophilic species of Tabanid in Central Amazon, Brazil.
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In Central Amazon, Brazil, the tabanid Phorcotabanus cinereus (Wiedemann) was recorded attacking the native duck Cairina moschata (Linnaeus) (Anseriformes, Anatidae). The flight and behavior of the tabanid during the attacks and the host's defenses were videotaped and analyzed in slow motion. The tabanid was recorded flying rapidly around the heads of the ducks before landing. Landing always took place on the beak, and then the tabanid walked to the fleshy caruncle on the basal part of the beak to bite and feed. Firstly the duck defends itself through lateral harsh head movements, and then, when it is being bitten, it defends itself by rubbing its head on the body, or dipping the head into water, when swimming. If disturbed, the fly resumed the same pattern of flight as before and would generally try to land again on the same host and bite in the same place. This feeding activity was observed predominantly between 9:30 am and 4:30 pm and always in open areas, near aquatic environments, from June 1996 to January 1997, the dry season in Central Amazon. To test the attractiveness of other animals to P. cinereus, mammals, caimans and domestic and wild birds were placed in suitable habitat and the response of P. cinereus observed. P. cinereus did not attack these animals, suggesting that this species has a preference for ducks, which are plentiful in the region. (+info)
Psychological adjustment of children and adolescents with chronic arthritis: a meta-analytic review.
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OBJECTIVE: To review studies of psychological adjustment among children and adolescents with chronic arthritis to determine whether they are at more risk for development of adjustment problems than controls. METHODS: We used meta-analytic techniques to review 21 studies reporting overall adjustment problems, internalizing symptoms, externalizing symptoms, or self-concept among youths with arthritis. RESULTS: Youths with arthritis displayed increased risk for overall adjustment problems and internalizing symptoms, but not for externalizing symptoms or poor self-concept. Risk was greater in studies making comparisons to study controls rather than to norms and in studies including mixed disease samples (arthritis plus other rheumatic diseases) rather than samples of youths with arthritis only. CONCLUSIONS: Results suggest the importance of assessing for internalizing problems among youths with chronic arthritis. Future research may benefit from inclusion of child self-report of adjustment problems, diagnostic specificity in reporting results, and use of adjustment measures without somatic items. (+info)
Pain reactivity and somatization in kindergarten-age children.
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OBJECTIVE: To evaluate predictors of somatization and pain reactivity in childhood. METHODS: Facial expressions of children undergoing inoculation were scored for pain reactivity. Measures of temperament, pain experience, pain models, parental behavior, and parental ability to decode pain were examined for their ability to predict pain reactivity and somatization in a structural modeling analysis. RESULTS: Pain reactivity was associated positively with parental reports of their child's somatization. Child temperament, previous negative experiences with medical procedures, and maternal responses to their children's pain were positively associated with pain reactivity. CONCLUSIONS: Temperament and pain experience may play a role in children's pain reactivity, and reactivity may contribute to the development of somatization. Although the model that guided the analysis proved to be a reasonable description of the outcomes, several anticipated relationships were not significant. We discuss implications for a refined model of somatization and for early identification and prevention. (+info)
Anatomical connections of the periaqueductal gray: specific neural substrates for different kinds of fear.
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The periaqueductal gray (PAG) has been traditionally considered to be an exit relay for defensive responses. Functional mapping of its subdivisions has advanced our knowledge of this structure, but synthesis remains difficult mainly because results from lesion and stimulation studies have not correlated perfectly. After using a strategy that combined both techniques and a reevaluation of the available literature on PAG function and connections, we propose here that freezing could be mediated by different PAG subdivisions depending on the presence of immediate danger or exposure to related signaling cues. These subdivisions are separate functional entities with distinct descending and ascending connections that are likely to play a role in different defensive responses. The existence of ascending connections also suggests that the PAG is not simply a final common path for defensive responses. For example, the possibility that indirect ascending connections to the cingulate cortex could play a role in the expression of freezing evoked by activation of the neural substrate of fear in the dorsal PAG has been considered. (+info)
The Children's Somatization Inventory: further evidence for its reliability and validity in a pediatric and a community sample of Dutch children and adolescents.
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OBJECTIVE: To examine the psychometric properties of the Children's Somatization Inventory (CSI) in the Netherlands. METHOD: The CSI and a number of personality and psychopathology questionnaires were administered to Dutch schoolchildren (N = 479), children referred to a pediatric clinic (N = 63), and children's parents. RESULTS: Factor analysis yielded a number of factors that have also been found in previous research, viz., pain/weakness, gastrointestinal symptoms, and pseudoneurological symptoms. The reliability (internal consistency) of the CSI was satisfactory. Furthermore, support was obtained for the validity of the CSI. More specifically, the scale correlated in a theoretically meaningful way with child and parent reports of personality and psychopathology, and discriminated well between healthy and pediatric children. Finally, highly similar psychometric properties were obtained for the Parent version of the CSI (i.e., PCSI). CONCLUSION: The Dutch version of the CSI seems to be a reliable and valid self-report measure for assessing somatization symptoms in children and adolescents. (+info)
DEFENSIVE THINKING IN ALCOHOL ADDICTS.
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Every day in Canada and the United States thousands of patients seek medical help for diseases and injuries acquired as a result of excessive alcohol consumption. Unfortunately much of the medical effort expended in this way is wasted. Failure to bridge the gap between initial treatment and a rehabilitation program is the main reason for this waste.Since the power of the abnormal desire in addiction compels the victim to continue to indulge in spite of his awareness of his addiction, he becomes more and more defensive. His thinking is marked by alibis, lying, projection, resentment and suspicion. Resistance to treatment becomes an integral part of the disability.The addict usually cannot stop defending his dependence simply because he is advised to do so. However, a physician can often find ways to interrupt defensive thinking long enough to initiate a treatment and rehabilitation program if he will consider the primary and secondary factors concerned. (+info)
Sensorimotor integration in the precentral gyrus: polysensory neurons and defensive movements.
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The precentral gyrus of monkeys contains a polysensory zone in which the neurons respond to tactile, visual, and sometimes auditory stimuli. The tactile receptive fields of the polysensory neurons are usually on the face, arms, or upper torso, and the visual and auditory receptive fields are usually confined to the space near the tactile receptive fields, within about 30 cm of the body. Electrical stimulation of this polysensory zone, even in anesthetized animals, evokes a specific set of movements. The movements resemble those typically used to defend the body from objects that are near, approaching, or touching the skin. In the present study, to determine whether the stimulation-evoked movements represent a normal set of defensive movements, we tested whether they include a distinctive, nonsaccadic, centering movement of the eyes that occurs during defensive reactions. We report that this centering movement of the eyes is evoked by stimulation of sites in the polysensory zone. We also recorded the activity of neurons in the polysensory zone while the monkey made defensive reactions to an air puff on the face. The neurons became active during the defensive movement, and the magnitude of this activity was correlated with the magnitude of the defensive reaction. These results support the hypothesis that the polysensory zone in the precentral gyrus contributes to the control of defensive movements. More generally, the results support the view that the precentral gyrus can control movement at the level of complex sensorimotor tasks. (+info)