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While foraging, eavesdropping predators home in on the signals of their prey. Many prey signal from aggregations, however, and predators already en route to attack one individual often encounter the signals of other prey. Few studies have examined whether eavesdropping predators update their foraging decisions by switching to target these more recently signaling prey. Switching could result in reduced localization errors and more current estimates of prey location. Conversely, assessing new cues while already in pursuit of another target might confuse or distract a predator. We tested whether fringed-lipped bats (Trachops cirrhosus) switch prey targets when presented with new cues mid-approach and examined how switching and the distance between simulated prey influence attack accuracy, latency, and prey capture success. During nearly 80% of attack flights, bats switched between túngara frog (Engystomops pustulosus) calls spaced 1 m apart, and switching resulted in lower localization errors. The switching rate was reduced, and the localization advantage disappeared for calls separated by 3 m. Regardless of whether bats switched targets, attacks were less accurate, took longer, and were less often successful when calls were spaced at larger distances, indicating a distraction effect. These results reveal that fringed-lipped bats attend to cues from non-targeted prey during attack flights and that the distance between prey alters the effectiveness of attacks, regardless of whether a bat switches targets. Understanding how eavesdropping predators integrate new signals from neighboring prey into their foraging decisions will lead to a fuller picture of the ways unintended receivers shape the evolution of signaling behavior.
Assuntos
Quirópteros , Animais , Anuros , Sinais (Psicologia) , Comportamento PredatórioRESUMO
Predators often eavesdrop on sexual displays of their prey. These displays can provide multimodal cues that aid predators, but the benefits in attending to them should depend on the environmental sensory conditions under which they forage. We assessed whether bats hunting for frogs use multimodal cues to locate their prey and whether their use varies with ambient conditions. We used a robotic set-up mimicking the sexual display of a male túngara frog (Physalaemus pustulosus) to test prey assessment by fringe-lipped bats (Trachops cirrhosus). These predatory bats primarily use sound of the frog's call to find their prey, but the bats also use echolocation cues returning from the frog's dynamically moving vocal sac. In the first experiment, we show that multimodal cues affect attack behaviour: bats made narrower flank attack angles on multimodal trials compared with unimodal trials during which they could only rely on the sound of the frog. In the second experiment, we explored the bat's use of prey cues in an acoustically more complex environment. Túngara frogs often form mixed-species choruses with other frogs, including the hourglass frog (Dendropsophus ebraccatus). Using a multi-speaker set-up, we tested bat approaches and attacks on the robofrog under three different levels of acoustic complexity: no calling D. ebraccatus males, two calling D. ebraccatus males and five D. ebraccatus males. We found that bats are more directional in their approach to the robofrog when more D. ebraccatus males were calling. Thus, bats seemed to benefit more from multimodal cues when confronted with increased levels of acoustic complexity in their foraging environments. Our data have important consequences for our understanding of the evolution of multimodal sexual displays as they reveal how environmental conditions can alter the natural selection pressures acting on them.
Assuntos
Anuros/fisiologia , Quirópteros/fisiologia , Sinais (Psicologia) , Ecolocação/fisiologia , Comportamento Predatório/fisiologia , Vocalização Animal , Animais , Corte , Masculino , Movimento , Comportamento Sexual AnimalRESUMO
INTRODUCTION: Rural, minority populations are disproportionately affected by overweight and obesity and may benefit from lifestyle modification programs that are tailored to meet their unique needs. Obesity interventions commonly use goal setting as a behavior change strategy; however, few have investigated the specific contribution of goal setting to behavior change and/or identified the mechanisms by which goal setting may have an impact on behavior change. Furthermore, studies have not examined goal setting processes among racial/ethnic minorities. Using data from an obesity intervention for predominately minority women in rural North Carolina, this study sought to examine whether intervention participation resulted in working on goals and using goal setting strategies which in turn affected health behavior outcomes. It also examined racial/ethnic group differences in working on goals and use of goal setting strategies. METHODS: Data came from a community-based participatory research project to address obesity among low-income, predominately minority women in rural North Carolina. A quasi-experimental intervention design was used. Participants included 485 women aged 18 years and over. Intervention participants (n=208) received health information and goal setting support through group meetings and tailored newsletters. Comparison participants (n = 277) received newsletters on topics unrelated to obesity. Surveys assessed physical activity, fruit and vegetable intake, goal-related stage of change, and use of goal setting strategies. Chi squared statistics were used to assess intervention group differences in changes in goal-related stage of change and use of goal setting strategies as well as racial/ethnic group differences in stage of change and use of goal setting strategies at baseline. The causal steps approach of Baron and Kenny was used to assess mediation. RESULTS: Intervention compared to comparison participants were more likely to move from contemplation to action/maintenance for the goals of improving diet (58% intervention, 44% comparison, p= 0.04) and physical activity (56% intervention, 31% comparison, p ≤ 0.0001). Intervention group differences were not found for moving from precontemplation to a higher category. At baseline, black compared to white participants were more likely to be working on the goals of getting a better education (p < 0.0001), owning a home (p < 0.01), starting a business (p < 0.0001), and improving job skills (p <0.05). For whites only, intervention participants were more likely than comparison participants to move from contemplation to action/maintenance for the goal of improving diet ( p< 0.05). For both blacks (p < 0.05) and whites (p < 0.0001), intervention participants were more likely than comparison participants to move from contemplation to action/maintenance for the goal of increasing physical activity. For all participants, progression in stages of change mediated the intervention effect on physical activity, but not fruit and vegetable intake. The intervention did not reveal an impact on use of goal setting strategies. CONCLUSIONS: In this sample of low-income, rural women, the intervention's goal setting component influenced behavior change for participants who were contemplating lifestyle changes at baseline. Racial/ethnic group differences in goal setting indicate the need to gain greater understanding of individual, social, and environmental factors that may uniquely have an impact on goal setting, and the importance of tailoring obesity intervention strategies for optimal, sustainable behavior change.
Assuntos
Objetivos , Comportamentos Relacionados com a Saúde/etnologia , Obesidade/terapia , Pobreza , População Rural , Adulto , Negro ou Afro-Americano , Pesquisa Participativa Baseada na Comunidade , Dieta , Exercício Físico , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pessoa de Meia-Idade , North Carolina/epidemiologia , Obesidade/etnologia , Obesidade/prevenção & controle , População Branca , Saúde da MulherRESUMO
Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Currently, cardiovascular disease risk algorithms play a role in primary prevention. However, this is complicated by a lack of powerfully predictive biomarkers that could be observed in individuals before the onset of overt symptoms. A key potential biomarker for heart disease is the vascular endothelial growth factor (VEGF-A), a molecule that plays a pivotal role in blood vessel formation. This molecule has a complex biological role in the cardiovascular system due to the processes it influences, and its production is impacted by various CVD risk factors. Research in different populations has shown single nucleotide polymorphisms (SNPs) may affect circulating VEGF-A plasma levels, with some variants associated with the development of CVDs, as well as CVD risk factors. This minireview aims to give an overview of the VEGF family, and of the SNPs reported to influence VEGF-A levels, cardiovascular disease, and other risk factors used in CVD risk assessments.
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Ground shaking close to the causative fault of an earthquake is more intense than it was previously believed to be. This raises the possibility that large numbers of buildings and other structures are not sufficiently resistant for the intense levels of shaking that can occur close to the fault. Many structures were built before earthquake codes were adopted; others were built according to codes formulated when less was known about the intensity of near-fault shaking. Although many building types are more resistant than conventional design analyses imply, the margin of safety is difficult to quantify. Many modern structures, such as freeways, have not been subjected to and tested by near-fault shaking in major earthquakes (magnitude 7 or greater). Damage patterns in recent moderate-sized earthquakes occurring in or adjacent to urbanized areas (17), however, indicate that many structures, including some modern ones designed to meet earthquake code requirements, cannot withstand the severe shaking that can occur close to a fault. It is necessary to review the ground motion assumed and the methods utilized in the design of important existing structures and, if necessary, to strengthen or modify the use of structures that are found to be weak. New structures situated close to active faults should be designed on the basis of ground motion estimates greater than those used in the past. The ultimate balance between risk of earthquake losses and cost for both remedial strengthening and improved earthquake-resistant construction must be decided by the public. Scientists and engineers must inform the public about earthquake shaking and its effect on structures. The exposure to damage from seismic shaking is steadily increasing because of continuing urbanization and the increasing complexity of lifeline systems, such as power, water, transportation, and communication systems. In the near future we should expect additional painful examples of the damage potential of moderate-sized earthquakes in urban areas. Over a longer time span, however, we can significantly reduce the risk to life and property from seismic shaking through better land utilization, improved building codes and construction practices, and at least the gradual replacement of poor buildings by more resistant buildings. Progress toward reducing risk from seismic shaking through better building design is slowed by deficiencies in our knowledge about the nature of damaging ground motion and the failure mechanisms in structures. For example, lacking observational data, seismologists must rely on simplified theoretical and numerical models of the earthquake process to estimate near-fault ground motion, especially for earthquakes as large as magnitude 7 and 8. Because such models have not been adequately tested against data, their reliability is unknown. Engineers lack detailed information about failure processes in structures during an earthquake. Although many structures have been instrumented to measure their response to an earthquake, few records have been obtained from buildings that actually sustained significant structural damage and few structures are properly instrumented to measure all the modes of deformation that are likely to contribute to failure. Moreover, the fact that many structures have withstood ground motion more intense than that assumed in their design indicates that conventional methods of design do not take into account important contributions to earthquake resistance by nonstructural elements and by the ability of structural elements to deform inelastically without necessarily causing failure of the structure. It is fortunate when such reserve resistance exists, but better understanding of the sources of reserve strength is needed to determine how large a margin of safety they confer and how they might be affected by changes in construction practices and materials with time. In the next few years we look forward to significant advances in knowledge and to more effective application of what is already known, largely because of substantial funding of research related to seismic engineering by the National Science Foundation (18). The increasing number of strong-motion seismographs operating in seismically active regions (19) will likely provide for the first time a number of records of damaging levels of ground motion. Significant effort is being directed toward obtaining near-fault records, although many probable sites of future large earthquakes remain inadequately instrumented, especially outside the conterminous United States. New and more complete information on building response and damage mechanisms will be obtained by improved instrumentation of structures and through laboratory investigations of failure in structures and structural elements. Further developments in computer technology and in computer modeling techniques will permit more realistic simulations of the seismic response of soils and structures that take into account their inelastic behavior and their strain-dependent properties. Earthquake design codes will continually be revised to better utilize existing knowledge concerning the nature of strong ground motion and the dynamic behavior of buildings during earthquakes and to incorporate new knowledge and also experiences gained from future earthquakes. We believe that application of new knowledge, improvements in earthquake-resistant design and construction, and remedial strengthening or replacement of weak existing structures can significantly reduce our current level of exposure to earthquake hazards.
RESUMO
Seismological investigations show that the Point Mugu earthquake involved north-south crustal shortening deep within the complex fault zone that marks the southern front of the Transverse Ranges province. This earthquake sequence results from the same stress system responsible for the deformation in this province in the Pliocene through Holocene and draws attention to the significant earthquake hazard that the southern frontal fault system poses to the Los Angeles metropolitan area.
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Anthropogenic noise can interfere with environmental information processing and thereby reduce survival and reproduction. Receivers of signals and cues in particular depend on perceptual strategies to adjust to noisy conditions. We found that predators that hunt using prey sounds can reduce the negative impact of noise by making use of prey cues conveyed through additional sensory systems. In the presence of masking noise, but not in its absence, frog-eating bats preferred and were faster in attacking a robotic frog emitting multiple sensory cues. The behavioral changes induced by masking noise were accompanied by an increase in active localization through echolocation. Our findings help to reveal how animals can adapt to anthropogenic noise and have implications for the role of sensory ecology in driving species interactions.
Assuntos
Adaptação Fisiológica , Quirópteros/fisiologia , Ecolocação , Ruído , Comportamento Predatório/fisiologia , Localização de Som , Animais , Anuros , Peso Corporal , Sinais (Psicologia) , MasculinoRESUMO
The importance of acetyl-CoA carboxylase in regulation of lipid synthesis for barley and maize leaves has been quantitatively assessed using, as specific inhibitors, the herbicides fluazifop and sethoxydim. Apparent flux control coefficients of about 0.58 and 0.52 were determined for acetyl-CoA carboxylase in barley and maize leaves, respectively. These results show that acetyl-CoA carboxylase is the major flux controlling enzyme for light-stimulated lipid synthesis in these tissues.
Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Herbicidas/farmacologia , Hordeum/enzimologia , Zea mays/enzimologia , Cicloexanonas/farmacologia , Di-Hidropiridinas/farmacologia , Lipídeos/biossínteseRESUMO
By library screening and PCR we have obtained cDNA clones which encode the gamma subunit of the CCT chaperonin complex from Xenopus laevis. The gene (XlCctg), which encodes the CCT gamma subunit contains an open reading frame which codes for 547 amino acid residues (60 kDa) and the predicted amino acid sequence shares a high degree of sequence identity with other CCT gamma homologues. The XlCctg mRNA measures 2.1 kb and is expressed ubiquitously in all of the X. laevis tissues examined. The mRNA levels of XlCctg are significantly higher in the ovary compared with other tissues.
Assuntos
Chaperoninas/genética , Genes/genética , Xenopus laevis/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Chaperonina com TCP-1 , DNA Complementar/genética , Feminino , Expressão Gênica , Masculino , Dados de Sequência Molecular , Especificidade de Órgãos , RNA Mensageiro/análise , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
A cDNA clone encoding lipoprotein lipase has been isolated from an ovine adipocyte library. Sequencing of this clone has revealed a single open reading frame encoding a 450 amino acid protein. Comparison with known LPL sequences from other species shows a high degree of conservation in the sequence of the protein and in the 5' untranslated region of the DNA sequence.
Assuntos
Tecido Adiposo/enzimologia , DNA/genética , Lipase Lipoproteica/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular/métodos , Biblioteca Gênica , Humanos , Camundongos , Dados de Sequência Molecular , Fases de Leitura Aberta , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , OvinosRESUMO
PURPOSE: To establish the optimum biologic dose and maximal-tolerated dose (MTD) of once-daily, subcutaneous recombinant human granulocyte-macrophage colony-stimulating factor derived from yeast (RhuGM-CSF) in patients with breast cancer. PATIENTS AND METHODS: Seventeen patients with either newly diagnosed breast cancer with more than four involved axillary nodes (five patients) or metastatic breast cancer (12 patients) were treated with cyclophosphamide 1 g/m2, doxorubicin 50 mg/m2, and fluorouracil 500 mg/m2 (CAF) intravenously (IV) once every 3 weeks. RhuGM-CSF was administered subcutaneously once daily for 14 days after the second and third CAF cycles, at one of three dose levels. RESULTS: The 125-micrograms/m2/d RhuGM-CSF dose level shortened the duration of neutropenia in only one of three patients. The 250-micrograms/m2/d level was effective in shortening the duration of the neutropenic nadir (< .5 x 10(9)/dL) by 2 or more days in five of six patients. The 500-micrograms/m2/d level caused severe toxicity (chest pain, two patients; deep vein thrombosis, one patient) in three of eight patients. CONCLUSION: RhuGM-CSF administered once daily at the 250-micrograms/m2/d level is well tolerated and effective in shortening the duration of the neutrophil nadir by 2 or more days after CAF therapy.
Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Neutropenia/prevenção & controle , Adulto , Idoso , Quimioterapia Adjuvante , Ciclofosfamida/efeitos adversos , Doxorrubicina/efeitos adversos , Feminino , Fluoruracila/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Humanos , Injeções Subcutâneas , Metástase Linfática , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Saccharomyces cerevisiaeRESUMO
Airborne lead has been measured at four urban, one semi-urban and one rural site in Wales during 1984, 1985 and 1986 to assess the effect of the reduction in lead additives in petrol which was required by an EC Directive at the beginning of 1986. The results showed a 52-61% fall in air lead in accord with the 63% reduction in petrol lead.
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Poluentes Atmosféricos/análise , Gasolina , Chumbo/análise , Petróleo , Humanos , População Rural , Estações do Ano , População Suburbana , População Urbana , País de GalesRESUMO
The present study attempted to assess the effectiveness of commonly used deepening techniques and of surreptitiously provided stimulation on hypnotizability scores, in-hypnosis depth reports, retrospective realness ratings, and the Field Inventory of Hypnotic Depth (Field, 1965). High, medium, and low hypnotizables were assigned in equal numbers to 1 of 3 groups, each containing 54 Ss. Controls were compared to Ss receiving 2 deepening techniques or 2 suggestions for positive and negative hallucinations that were surreptitiously enhanced. Of the 4 dependent measures employed, the only significant difference between groups related to a change in depth reports for the manipulation items themselves, leading to the conclusion that the effect of the techniques was at best minimal and transient. Some methodological and conceptual issues are also discussed.
Assuntos
Conscientização , Hipnose/métodos , Teste de Realidade , Sugestão , Adulto , Feminino , Humanos , MasculinoRESUMO
Previous hypnosis studies obtaining retrospective depth reports (e.g., Perry & Laurence, 1980) or retrospective realness reports (e.g., Page & Handley, 1992) have found a "parallel nonoverlapping" pattern between mean depth or realness and susceptibility scale items for high- through low-susceptible subjects. To determine if such a pattern, as well as differential item difficulty in general, is specific to hypnosis, 98 undergraduates were administered the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) of Shor and Orne (1962) as a "test of visual and motor imagination," omitting the eye-closure induction (item #2). A pattern similar to other studies that employed hypnosis was produced. While supporting attribution theory (Bowers, 1973), results also indicate that differences in item difficulty are not specific to hypnosis, but instead are related more broadly to imagination.
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Hipnose/métodos , Determinação da Personalidade/estatística & dados numéricos , Adolescente , Adulto , Idoso , Feminino , Humanos , Imaginação , Individualidade , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos TestesRESUMO
Clark L. Hull made many contributions to the field of hypnosis. The contributions discussed in this paper include his attempts to dispel misconceptions about hypnosis, comparisons of capacities in the hypnotic state with those in the awake state, a sampling of early findings that are still valid today, and examples of his contributions to methodology. Additionally, the roots of many modern-day models and concepts are to be found in his early works.
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Hipnose , Adolescente , Fatores Etários , Criança , Humanos , Hipnose/métodos , Modelos Psicológicos , SugestãoRESUMO
A case of apparent hypnotic sequelae occurring in a non-clinical research context (involving a college student) is reported. Following his participation in a group session in which a standard hypnotic susceptibility scale was administered, 19 year-old Michael reported a number of reactions common to the hypnotic sequelae literature including dizziness, a mild headache, trembling, and slight nausea. An interview with Michael revealed several alternative sources of his reaction, highlighting the ever-present problem of attribution.
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Hipnose , Adulto , Tontura/diagnóstico , Cefaleia/diagnóstico , Humanos , Masculino , Abandono do Hábito de Fumar , Fatores de TempoRESUMO
In the present study we assessed the efficacy of several procedures in minimizing the occurrence of aftereffects of a hypnotic induction. We gave experimental subjects (n = 347) a brief lecture dispelling some myths about hypnosis, told them no psychological treatment would be undertaken, and then administered the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) in which all references to aftereffects had been removed. We gave the standard version of the HGSHS:A to control subjects (n = 340). Although the treatment condition did not reduce the overall incidence of effects, long-term effects were significantly reduced. Medical and psychosocial histories were obtained from subjects prior to the induction, but they proved to be of limited value in predicting sequelae. Contrary to the results of Coe & Ryken (1979), hypnosis produced more frequent sequelae than a nonhypnotic classroom experience (watching a film followed by an introductory psychology lecture) for subjects in an ad hoc control group.
Assuntos
Nível de Alerta , Depressão/prevenção & controle , Hipnose/métodos , Transtornos Psicóticos/prevenção & controle , Adolescente , Adulto , Depressão/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inventário de Personalidade , Transtornos Psicóticos/psicologia , Fatores de Risco , SugestãoRESUMO
An unusual case is presented in which hypnosis was successfully used to overcome a $500 (five grams) per day cocaine addiction. The subject was a female in her twenties. Six months into her addiction, she acquired a commercial weight-control tape that she used successfully to stop smoking cigarettes (mentally substituting the word "smoking"), as well as to bring her down from her cocaine high and allow her to fall asleep. After approximately 8 months of addiction, she decided to use the tape in an attempt to overcome the addiction itself. Over the next 4 months, she listened to the tape three times a day, mentally substituting the word "coke." At the end of this period, her addiction was broken, and she has been drug free for the past 9 years. Her withdrawal and recovery were extraordinary because hypnosis was the only intervention, and no support network of any kind was available.
Assuntos
Cocaína , Hipnose , Transtornos Relacionados ao Uso de Substâncias/terapia , Adulto , Feminino , Humanos , Resultado do TratamentoRESUMO
Two cases of hypnotic sequelae occurring in a research context (with a non-clinical college population) are reported. Case 1 was a male who experienced retroactive amnesia following hypnosis: He was unable to recall familiar telephone numbers later that day. This was not a continuation of an earlier confusion or drowsiness (as is often found) since he indicated he was wide awake following hypnosis. Two parallels exist with previous reports: unpleasant childhood experiences with chemical anesthesia and a conflict involving a wish to experience hypnosis but a reluctance to relinquish control. Case 2 was a female who, while in hypnosis, experienced an apparent epileptic seizure that had characteristics of both petit mal and grand mal seizures. Although having a history of epilepsy, she had not had a seizure in 7 years. We suspect that the seizure was psychogenic and may have been triggered by wording used in the hypnotic scale or other similarities. Possible mechanisms are discussed and preventative recommendations are made.
Assuntos
Amnésia Retrógrada/complicações , Amnésia/complicações , Hipnose , Convulsões/complicações , Adolescente , Amnésia Retrógrada/psicologia , Feminino , Humanos , Masculino , Convulsões/fisiopatologiaRESUMO
First we exposed experimental subjects to either the hypnotic items they were about to experience or to those items embedded in a longer list of hypnotic items. We then asked them to give item-difficulty ratings prior to administration of a standard group susceptibility scale. Controls received no prior exposure to any hypnotic items. We obtained four dependent measures: hypnotic susceptibility score, an in-hypnosis depth report, Field (1965) Depth Inventory score, and retrospective depth reports. The three groups did not differ significantly on any of the dependent measures. Although this result differs from that of Shor, Pistole, Easton, and Kihlstrom (1984), who found that prior knowledge of items depressed susceptibility scores, this may be due to procedural differences between the two studies. Subjects' self-predictions of item difficulty were poor to modest, and accuracy of predictions was not related to any of the four dependent measures.