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Hypothesis Suggesting (hypothesis + suggesting)
Selected AbstractsThe Long-Term Effects of Reconciliation in Japanese Macaques Macaca fuscataETHOLOGY, Issue 11 2001Nicola F. Koyama With one exception, all previous studies of reconciliation in non-human primates (friendly reunion between former opponents) have focused on demonstrating the immediate, short-term effects despite the widely held view that reconciliation has a long-term function of repairing social relationships following aggression. To investigate this long-term function I compared mean interaction rates between opponents during the 10 d following reconciled and non-reconciled conflicts to baseline levels of interaction. Aggression rates during the 10 d after non-reconciled conflicts were significantly higher than the baseline rate, whereas after reconciled conflicts aggression was minimal. Similarly, grooming, proximity and approach rates during the 10 d after non-reconciled conflicts were significantly lower than the baseline rate whereas grooming, proximity and approach rates in the 10 d after reconciled conflicts were restored to baseline levels. These results indicate that there are consequences to not reconciling with a former opponent and highlight the fact that these may be costly in terms of increased risk of long-term aggression and reduced affiliation. The data support predictions from the Relationship-Repair Hypothesis suggesting that reconciliation functions as a mechanism for the repair of social relationships damaged by aggression. [source] Effects of terrestrial pollutants on insect parasitoids,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2009Casey D. Butler Abstract Parasitoids are important organisms in the regulation of insect herbivores in natural, urban, and agricultural ecosystems. The impact of pollutants acting on parasitoids has not been extensively reviewed. This prompted us to propose a falsifiable null hypothesis (pollutants have no effects on parasitoids) and two alternative hypotheses (pollution negatively or positively affects parasitoids) to assess in the available literature the effects of pollutants acting on parasitoids. We found 26 studies examining 39 biological systems that met our criteria for inclusion. Of these studies, 18 of the 39 biological systems (46.2%) supported the null hypothesis while 18 (46.2%) supported the first alternative hypothesis in which pollutants exhibited negative effects on parasitoids. Only a small percentage of the studies (7.6%, 3 of 39) supported the second alternative hypothesis suggesting that pollutants had positive effects on parasitoids. We provide a synthesis of the available data by pollution type, summarize trends for different pollutants, and suggest future areas of research. [source] The Middle Asian Element in the Southern Rocky Mountain Flora of the western United States: a critical biogeographical reviewJOURNAL OF BIOGEOGRAPHY, Issue 5 2003William A. Weber Abstract Aim, Presentation of an hypothesis suggesting that the extraordinarily similarity of the Russian Altai and the American Southern Rocky Mountain Flora represents an Oroboreal Flora; that had to have had an essential continuity across the northern part of the world in the Tertiary period, constituting a highland and steppe component of the better-known Arcto-Tertiary Flora of eastern and far-western North America and eastern Asia. Location, North America and Middle (Altai) Asia. Methods, Summarization of the author's field and herbarium studies of whole floras over a period of over 60 years, consisting of successive specializations in vascular plants, lichens, and bryophytes. Main conclusions, (1) The modern alpine and associated marginal steppe and montane floras contain taxa of Tertiary age. (2) The floras of the southern mountains antedate those of the present-day Arctic. (3) The Middle Asiatic and the North American floras once enjoyed a contiguous existence over a broad area involving connections between North America and Asia across the North Pole by way of Greenland. Their present disjunctions are products of extinction and attrition of ranges, not of long-distance migration or dispersal mechanisms. (4) North-eastern North American disjunctions of so-called Cordilleran species (the Nunatak hypothesis) need not require explanations involving long-distance dispersal or migration, but represent relictual populations of the once widely distributed Oroboreal flora. [source] Discontinuous gas exchange and water loss in the keratin beetle Omorgus radula: further evidence against the water conservation hypothesis?PHYSIOLOGICAL ENTOMOLOGY, Issue 4 2000Mareza Bosch Summary Discontinuous gas exchange cycles are demonstrated in Omorgus radula (Erichson) (Coleoptera, Trogidae) for the first time, thus extending evidence for such cycles to another family of beetles. The closed, flutter and open phases of the cycle were clearly distinguishable in this species, and the duration of these phases was 221 ± 28, 1403 ± 148 and 755 ± 43 s (mean ± SE), respectively. No evidence for significant intraspecific mass scaling of VCO2 or any of the components of the cycle was found. Although the prolonged F-phase recorded here is unusual for many insects, it has previously been found in other scarabaeoid beetles, especially those from xeric environments. It has been suggested that such modulation of the discontinuous gas exchange cycle may result in a reduced VCO2 and, consequently, reduced water loss. In O. radula VCO2 (15.25 ± 1.49 ,l/h) was considerably lower than that predicted from its body mass (0.207 ± 0.006 g). However, the small relative contribution of respiratory transpiration (6.5%) to total water loss indicated that reduced VCO2 has little to do with water economy. Rather, it may be a consequence of generally low activity levels of these beetles. The low respiratory water loss, but distinct subterranean component in the adult life of O. radula, lend some credence to the hypothesis suggesting that regular use of subterranean habitats might have been responsible for the evolution of discontinuous gas exchange cycles. However, non-adaptive hypotheses can still not be discounted. [source] Soluble CD14 at 2 yr of age: Gender-related effects of tobacco smoke exposure, recurrent infections and atopic diseasesPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2006K. C. Lødrup Carlsen The endotoxin receptor soluble CD14 (sCD14) has been implicated in the ,hygiene hypothesis' suggesting reduced allergic sensitization with bacterial stimulation. However, the relationship between early life sCD14 and allergic diseases is conflicting. We aimed to investigate whether possible risk factors for allergic diseases were associated with sCD14 levels at 2 yr of age. In the nested case,control study of the birth cohort studies ,Environment and Childhood Asthma study in Oslo' 411 children selected with recurrent bronchial obstruction (rBO) (n = 241) and no bronchial obstruction (n = 170) by 2 yr were investigated with skin prick test and structured parental interview at age 2 yr. Exposure to tobacco smoke, pets and infections was recorded semi-annually by questionnaires (0,2 yr). The sCD14 was analysed from frozen, stored serum by ELISA technique. Regression analyses were performed in all subjects with complete data (n = 406, 180 girls), and in girls and in boys separately. Mean sCD14 (ng/ml) was significantly higher among girls 2035 (1973,2096) vs. 1947 (1890,2004) (boys). The sCD14 was significantly reduced among girls exposed to antenatal maternal smoking and with parental asthma, after adjusting for age, parental rhino-conjunctivitis, pet keeping and childhood infections. Recurrent otitis media (OM) increased and common colds significantly decreased sCD14 levels in girls. Boys with atopic dermatitis and rBO had reduced sCD14. Pet exposure was not significantly associated with sCD14. We report novel gender-related effects of sCD14 in early life and suggest that gender, tobacco smoke exposure, age and middle ear disease in particular should be accounted for when assessing the role of sCD14 in childhood allergic diseases. [source] | ||||||||||