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Transitional Area (transitional + area)
Selected AbstractsEffect of variation in photoperiodic response on diapause induction and developmental time in the willow leaf beetle, Plagiodera versicoloraENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2000Michihiro Ishihara Abstract The willow leaf beetle, Plagiodera versicolora (Coleoptera: Chrysomelidae) overwinters in adult diapause. In this study, the photoperiodic responses for diapause induction and developmental time were examined in the Ishikari (Hokkaido, Japan) population of P. versicolora. All females entered reproductive diapause under short daylength (L10:D14), but 31.7% of females did not enter diapause under long daylength (L16:D8). The developmental time from oviposition to adult emergence was significantly longer at L10:D14 than that at L16:D8. Norm of reaction curves illustrated variation among families in the photoperiodic responses for diapause induction and for developmental time. ANOVA indicated significant family × photoperiod interactions in the developmental time. At L16:D8, developmental time was positively correlated with the incidence of diapause in females. This means that a female having a longer developmental time tends to have a longer critical photoperiod. Such variation may be maintained by differences in selection pressures on the growth rate and the critical photoperiod for diapause induction between univoltine and bivoltine genotypes because Ishikari is located in a transitional area between populations with univoltine and bivoltine life cycles. [source] Changes of articular cartilage after immobilization in a rat knee contracture modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009Yoshihiro Hagiwara Abstract The objective was to determine the changes of articular cartilage of the knee joint during immobilization in a rat model. The knee joints of adult male rats were immobilized at 150° of flexion using an internal fixator for 3 days, and 1, 2, 4, 8, and 16 weeks. The articular cartilage from the medial midcondylar region of the knee was obtained, divided into three areas (non-contact area, transitional area, contact area), and in each area, a degree of degeneration was evaluated by gross observation, histomorphometric grading, and measurements of thickness and number of chondrocytes. Elasticity of the articular cartilage was estimated by measuring the sound speed with use of scanning acoustic microscopy. Degeneration of the articular cartilage was mainly observed in the contact and transitional areas. Matrix staining intensity by safranin-O and number of chondrocytes were decreased in these two areas. The thickness of the articular cartilage in the non-contact and contact areas was unchanged, but it was increased in the transitional area. Decrease in sound speed was observed in the transitional area of both the femoral and tibial cartilage, indicating the softening of the articular cartilage. The changes of articular cartilage became obvious as early as 1 week after immobilization. These changes may be due to a lack of mechanical stress or a lack of joint fluid circulation during immobilization. Although we do not know the reversibility of these changes of articular cartilage, early mobilization is preferable to avoid these cartilage changes. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:236,242, 2009 [source] Socialization Ambiguity in Samoan Adolescents: A Model for Human Development and Stress in the Context of Culture ChangeJOURNAL OF RESEARCH ON ADOLESCENCE, Issue 1 2004Thomas W. McDade Rapid globalization is forcing youth around the world to confront new developmental challenges, and conceptual models are needed that can capture this experience and its developmental implications. Exposure to nontraditional lifestyles opens up new socialization opportunities and raises the possibility of stress-inducing dissonance between participating socializing agents and the messages they deliver. Socialization ambiguity is introduced as a model for culture change and adolescent stress, and it is applied to a sample of 10- to 20-year-olds (N=295) in the islands of Samoa. A physiological marker of stress (antibodies against the Epstein-Barr virus) is employed to overcome some of the difficulties associated with measuring stress outcomes. Socialization ambiguity is found to be a significant source of stress on the remote island of Savai'i and the transitional area of rural Upolu, although the direction of the association is different, possibly reflecting divergent socialization goals in these two regions. [source] Compositional Dependence of Piezoelectric Properties in NaxK1,xNbO3 Lead-Free Ceramics Prepared by Spark Plasma SinteringJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2006Bo-Ping Zhang Lead-free piezoelectric NaxK1,xNbO3 (x=20,80 mol%) ceramics were fabricated using spark plasma sintering at a low temperature (920°C). All the NaxK1,xNbO3 ceramics showed a similar orthorhombic phase structure, while the corresponding lattice parameters decreased from the KNbO3 side to the NaNbO3 side with increasing Na content. A discontinuous change in lattice parameter close to composition of 60 mol% Na indicated the presence of a transitional area that is similar to the morphotropic phase boundary (MPB) in NaxK1,xNbO3 ceramics. The sintered density of the NaxK1,xNbO3 ceramics decreased with increasing Na content, from a relative density of 99% for the K-rich side to 92% for the Na-rich side. The piezoelectric constant d33 and planar mode electromechanical coupling coefficient kp showed a maximum value of 148 pC/N and 38.9%, respectively, due to the similar MPB effects in the PZT system. [source] Frontotemporal dementia with motor neuron disease (amyotrophic lateral sclerosis with dementia)NEUROPATHOLOGY, Issue 1 2000Imaharu Nakano Frontotemporal dementia (FTD) with motor neuron disease means amyotrophic lateral sclerosis (ALS) with dementia. In the cerebrum of this condition, the medial cortex of the rostral temporal lobe is constantly and most remarkably involved. Another constant and quite characteristic lesion is neuronal loss localized to the CA1-subiculum transitional area at the level of the pes hippocampi. The rostral portion of the parahippocampal gyrus, and the amygdaloid nucleus are also involved. Ubiquitinated intracytoplasmic inclusions are seen in the dentate granule cells and parahippocampal gyrus neurons. Some cases of ALS without dementia show the identical temporal lobe degeneration as well as the cortical ubiquitinated inclusions, thus raising the possibility of overlooked dementia or premature death of the patients. Similarly, recently proposed motor neuron disease-inclusion dementia may be a forme fruste of ALS with dementia. [source] Combined hepatocellular cholangiocarcinoma originating from hepatic progenitor cells: immunohistochemical and double-fluorescence immunostaining evidenceHISTOPATHOLOGY, Issue 2 2008F Zhang Aims:, Combined hepatocellular cholangiocarcinoma (CHC) is a rare form of primary liver cancer, showing a mixture of hepatocellular and biliary features. Data suggest that most CHC arise from hepatic progenitor cells (HPCs). The aim was to investigate the origin of CHC. Methods and results:, Twelve cases of CHC were studied by immunohistochemistry for hepatocytic (hepPar1, ,-fetoprotein), cholangiocytic cytokeratin [(CK) 7, CK19], hepatic progenitor cell (OV-6), haematopoietic stem cell (c-kit, CD34), as well as CD45 and chromogranin-A markers. The combination of double-fluorescence immunostaining consisted of HepPar1 with CK19, and c-kit with OV-6. All 12 cases demonstrated more or less transitional areas, with strands/trabeculae of small, uniform, oval-shaped cells including scant cytoplasm and hyperchromatic nuclei embedded within a thick, desmoplastic stroma; however, two cases were found to consist entirely of such transitional areas. Simultaneous co-expression of hepPar1 and CK7, or CK19, was demonstrated in 10/12 (83.3%) cases of CHC. c-kit expression was noted in 10/12 (83.3%) cases, of which 7/10 (70%) showed co-expression of OV-6. Conclusions:, The results suggest that CHC are of HPC origin, supporting the concept that human hepatocarcinogenesis may originate from the transformation of HPCs. [source] Changes of articular cartilage after immobilization in a rat knee contracture modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009Yoshihiro Hagiwara Abstract The objective was to determine the changes of articular cartilage of the knee joint during immobilization in a rat model. The knee joints of adult male rats were immobilized at 150° of flexion using an internal fixator for 3 days, and 1, 2, 4, 8, and 16 weeks. The articular cartilage from the medial midcondylar region of the knee was obtained, divided into three areas (non-contact area, transitional area, contact area), and in each area, a degree of degeneration was evaluated by gross observation, histomorphometric grading, and measurements of thickness and number of chondrocytes. Elasticity of the articular cartilage was estimated by measuring the sound speed with use of scanning acoustic microscopy. Degeneration of the articular cartilage was mainly observed in the contact and transitional areas. Matrix staining intensity by safranin-O and number of chondrocytes were decreased in these two areas. The thickness of the articular cartilage in the non-contact and contact areas was unchanged, but it was increased in the transitional area. Decrease in sound speed was observed in the transitional area of both the femoral and tibial cartilage, indicating the softening of the articular cartilage. The changes of articular cartilage became obvious as early as 1 week after immobilization. These changes may be due to a lack of mechanical stress or a lack of joint fluid circulation during immobilization. Although we do not know the reversibility of these changes of articular cartilage, early mobilization is preferable to avoid these cartilage changes. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:236,242, 2009 [source] First record of tool use by wild populations of the yellow-breasted capuchin monkey (Cebus xanthosternos) and new records for the bearded capuchin (Cebus libidinosus)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2009Gustavo Rodrigues Canale Abstract Reports on use of stones as hammers and anvils to open hard nuts by wild capuchin monkeys are scarce and limited to Cebus libidinosus. Here, we report for the first time data on tool use,stones as hammer and anvils to open nuts,in wild C. xanthosternos and a description of new tool using sites for C. libidinosus. Our records were made by visiting anvil sites and by information obtained from local residents. We surveyed three different biomes: Caatinga (dry forest and thorn scrub), Cerrado (Brazilian bush savannah), and Atlantic forest (wet forest), all records of tool use were from Caatinga or transitional areas between habitats. The behavior is suggested to be routinely performed and widespread among several populations. The fruits of six plant species in different localities were opened with hammer stones by C. xanthosternos. Hammer stones were of similar weigh as those described in other studies of C. libidinosus. Conditions found in Caatinga, such as a more frequent use of the ground by the monkeys and/or food scarcity, may play an important role in the acquisition of nut-cracking behavior. The absence of more reports of nut cracking and other forms of tool use in other species of wild Cebus is likely to result from a lack of surveys in very dry and food limited habitats or intrinsic characteristics of other Cebus species. Am. J. Primatol. 71:366,372, 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||