Human Perception of Fear in Dogs Varies According to Experience with Dogs

To investigate the role of experience in humans’ perception of emotion using canine visual signals, we asked adults with various levels of dog experience to interpret the emotions of dogs displayed in videos. The video stimuli had been pre-categorized by an expert panel of dog behavior professionals as showing examples of happy or fearful dog behavior. In a sample of 2,163 participants, the level of dog experience strongly predicted identification of fearful, but not of happy, emotional examples. The probability of selecting the “fearful” category to describe fearful examples increased with experience and ranged from.30 among those who had never lived with a dog to greater than.70 among dog professionals. In contrast, the probability of selecting the “happy” category to describe happy emotional examples varied little by experience, ranging from.90 to.93. In addition, the number of physical features of the dog that participants reported using for emotional interpretations increased with experience, and in particular, more-experienced respondents were more likely to attend to the ears. Lastly, more-experienced respondents provided lower difficulty and higher accuracy self-ratings than less-experienced respondents when interpreting both happy and fearful emotional examples. The human perception of emotion in other humans has previously been shown to be sensitive to individual differences in social experience, and the results of the current study extend the notion of experience-dependent processes from the intraspecific to the interspecific domain

Cell cycle analysis of human peripheral blood T lymphocytes in long-term culture.

We have studied the cell cycle of resting T lymphocytes from long-term (LT) cultures following stimulation with phytohemagglutinin (PHA) and recombinant Interleukin 2 (IL-2). We examined the kinetics of entry into S phase by autoradiography, the accumulation of cellular RNA by microfluorometric techniques, and ultrastructural morphology by electron microscopy. In addition, we examined the expression at the mRNA level of six cell cycle-dependent growth-regulated genes (c-fos, c-myc, KC-1, JE-3, vimentin, and histone H3). We show that T lymphocytes of LT cultures respond differently to mitogenic stimulation than the T lymphocytes of freshly isolated peripheral blood mononuclear cell cultures. At the ultrastructural, biochemical, and molecular levels, resting T lymphocytes of LT cultures can be distinguished from physiological (G0) lymphocytes of peripheral blood

The effect of cytosine-arabinoside treatment on the overexpression of c-myc protooncogene in a case of prolymphocytic leukemia.

An unusually high level of expression of the c-myc protooncogene was observed in peripheral blood lymphocytes of a patient with prolymphocytic leukemia (atypical chronic lymphocytic leukemia). The overexpression of c-myc could not be attributed to a high level of proliferating activity of the leukemic cells in the blood. Treatment with cytosine-arabinoside at high doses abolished this altered expression of c-myc and resulted in a twofold increase in the expression of a gene sequence encoding the invariant gamma-chain of class II histocompatibility antigens, preferentially expressed in resting B lymphocytes. These observations suggest that the leukemic cells may have been arrested in the cell cycle outside the G0 phase. Our findings demonstrate that growth-regulated genes can be useful molecular markers of diseases with altered mechanisms of cellular proliferation

The effect of brief exercise on circulating CD34+ stem cells in early and late pubertal boys.

We tested the hypothesis that exercise could stimulate CD34+ peripheral blood hematopoietic stem cells (PBSC) in children. Fourteen early pubertal boys (EP, age 10.3 +/- 0.3 y) and 13 late pubertal boys (LP, age 16.5 +/- 0.4 y) performed 20 min of moderate-to-vigorous cycle ergometer exercise. Blood was drawn before and after exercise. Cells were stained for surface CD34+. Plasma granulocyte colony stimulating factor (G-CSF), Fms-like tyrosine kinase-3 (FLT-3), and stromal cell-derived factor-1 (SDF-1) were measured using ELISA. Exercise substantially increased PBSC (in EP from 112 +/- 21 to 182 +/- 30 cells/microL, p=0.0007; in LP from 63 +/- 8 to 152 +/- 21, p=0.0008), and to a smaller extent FLT-3 (in EP from 98 +/- 5 to 110 +/- 6 pg/mL, p<0.0001; in LP from 73 +/- 6 to 92 +/- 6, p<0.0001) and G-CSF (in EP from 26 +/- 4 to 29 +/- 4 pg/mL, p<0.0001; in LP from 14 +/- 1 to 18 +/- 1, p<0.0001). Baseline levels of PBSC, FLT-3, and G-CSF were significantly higher in EP. Exercise increased SDF-1 alpha only in LP, and the FLT-3 increase was greater in LP than EP. Brief exercise affects PBSC and PBSC mediators in children