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Response Capacity (response + capacity)
Selected AbstractsMetallothionein gene expression and protein levels in triploid and diploid oysters Crassostrea gigas after exposure to cadmium and zincENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2006Véronique Marie Abstract Quantitative real-time polymerase chain reaction (PCR) was used to compare for the first time the differential expression of metallothionein (MT) isoform genes, together with biosynthesis of the total MT proteins, in the gills of triploid and diploid juvenile Pacific oyster Crassostrea gigas in response to cadmium (Cd) and zinc (Zn) exposure. Oysters were exposed to Cd (0.133 ,M), Zn (15.3 ,M), and Cd+Zn for 14 d. Results showed similar response capacities to metal exposures in the two populations. No significant difference was revealed in terms of MT gene expression, MT protein synthesis, and Cd accumulation. However, triploid oysters bioaccumulated Zn 30% less efficiently than diploid oysters. Among the three MT isoform genes, CgMT2 appeared to be more expressed than CgMT1, whereas CgMT3 appeared to be anecdotal (106 times lower than CgMT2). CgMT2 and CgMT1 gene expression levels were increased sevenfold in the presence of Cd, whereas Zn appeared to have no effect. A twofold increase in MT protein levels occurred in response to Cd exposure. Discrepancies between mRNA and protein levels suggest that in C. gigas MT are regulated at the transcriptional level, as well as at the translational level. [source] DETERRENCE: CREDIBILITY AND PROPORTIONALITYECONOMICS & POLITICS, Issue 3 2009DANIEL G. ARCE This paper extends the analysis of deterrence to examine terrorism, nuclear proliferation, and rogue nations. Such situations are characterized by differential pre-emptive and response capacity, in contrast to the traditional deterrence literature on nuclear superpowers, where such factors are absent. We focus on the credibility of deterrence responses to pre-emption and show that credible (subgame-perfect) responses are rarely proportional. The analysis is also extended to asymmetric deterrence scenarios whereby credibility and proportionality depend on the potential aggressor's access to conflict technology and the responder's preferences for indirect conflict vs. the status quo. [source] Paleopathology and the origin of agriculture in the LevantAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Vered Eshed Abstract This study addresses changes in health which were consequential to the Neolithic transition in the southern Levant, judged on the basis of the study of specific and nonspecific stress indicators, trauma, and degenerative joint disease in 200 Natufian (hunter-gatherer) skeletons (10,500,8300 BC) and 205 Neolithic (agricultural) skeletons (8300,5500 BC) from the southern Levant. The comparison of the health profiles of pre-Neolithic (Natufian) and Neolithic populations reveals a higher prevalence of lesions indicative of infectious diseases among the Neolithic population, and an overall reduction in the prevalence of skull trauma among males. No change over time was observed in the prevalence of degenerative joint disease. These results indicate that in the southern Levant the Neolithic transition did not simply lead to an overall deterioration in health but rather resulted in a complex health profile which was shaped by 1) an increase exposure to disease agents, 2) changes in diet, 3) population aggregation in larger and denser settlements, 4) changes in activity patterns and the division of labor, and possibly 5) a higher resistant immunological system and response capacity to environmental aggressions (mainly infections). Am J Phys Anthropol 143:121,133, 2010. © 2010 Wiley-Liss, Inc. [source] Effect of diets containing different levels of highly unsaturated fatty acids on physiological and immune responses in Pacific whiteleg shrimp Litopenaeus vannamei (Boone) exposed to handling stressAQUACULTURE RESEARCH, Issue 16 2009Laurence Mercier Abstract Juveniles fed a diet containing a low or a high level of highly unsaturated fatty acids (HUFA) for 38 days were exposed to handling stress. In a first experiment, stress was applied daily for 30 days, after which the physiological and immunological variables were measured, whereas in a second experiment, stress was applied once and samples were obtained 1 and 24 h after the stressor event. Shrimp that were stressed for 30 days showed significantly lower survival, final weight and feed consumption compared with unstressed shrimp. The concentration of the high-density lipoprotein ,-glucan-binding protein was significantly higher in shrimp fed the high-HUFA diet. The glucose concentration in the haemolymph was significantly higher in long-term stressed shrimp compared to controls. The lactate level in the haemolymph was significantly lower in shrimp fed the high-HUFA diet. Lactate and glucose in the haemolymph increased in the 1-h stressed shrimp, but returned to normal levels in 24-h stressed shrimp. A negative effect of repeated-handling stress applied for 30 days was mainly observed on biological performance, whereas the single-stressor event had a more pronounced effect on shrimp physiological and immune responses measured 1 and 24 h after the stressor. A beneficial role of enrichment with HUFA on tolerance to handling stress was observed on immune response capacity. [source] Developmental experience alters information coding in auditory midbrain and forebrain neuronsDEVELOPMENTAL NEUROBIOLOGY, Issue 4 2010Sarah M.N. Woolley Abstract In songbirds, species identity and developmental experience shape vocal behavior and behavioral responses to vocalizations. The interaction of species identity and developmental experience may also shape the coding properties of sensory neurons. We tested whether responses of auditory midbrain and forebrain neurons to songs differed between species and between groups of conspecific birds with different developmental exposure to song. We also compared responses of individual neurons to conspecific and heterospecific songs. Zebra and Bengalese finches that were raised and tutored by conspecific birds, and zebra finches that were cross-tutored by Bengalese finches were studied. Single-unit responses to zebra and Bengalese finch songs were recorded and analyzed by calculating mutual information (MI), response reliability, mean spike rate, fluctuations in time-varying spike rate, distributions of time-varying spike rates, and neural discrimination of individual songs. MI quantifies a response's capacity to encode information about a stimulus. In midbrain and forebrain neurons, MI was significantly higher in normal zebra finch neurons than in Bengalese finch and cross-tutored zebra finch neurons, but not between Bengalese finch and cross-tutored zebra finch neurons. Information rate differences were largely due to spike rate differences. MI did not differ between responses to conspecific and heterospecific songs. Therefore, neurons from normal zebra finches encoded more information about songs than did neurons from other birds, but conspecific and heterospecific songs were encoded equally. Neural discrimination of songs and MI were highly correlated. Results demonstrate that developmental exposure to vocalizations shapes the information coding properties of songbird auditory neurons. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 70: 235,252, 2010. [source] | ||||||||||