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Scott, C. L., D. J. Walker, E. Cwiklinski, C. Tait, A. R. Tee, and S. C. Land. "Control of HIF-1α and vascular signaling in fetal lung involves cross talk between mTORC1 and the FGF-10/FGFR2b/Spry2 airway branching periodicity clock." American Journal of Physiology-Lung Cellular and Molecular Physiology 299, no. 4 (October 2010): L455—L471. http://dx.doi.org/10.1152/ajplung.00348.2009.
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Lung development requires coordinated signaling between airway and vascular growth, but the link between these processes remains unclear. Mammalian target of rapamycin complex-1 (mTORC1) can amplify hypoxia-inducible factor-1α (HIF-1α) vasculogenic activity through an NH2-terminal mTOR binding (TOS) motif. We hypothesized that this mechanism coordinates vasculogenesis with the fibroblast growth factor (FGF)-10/FGF-receptor2b/Spry2 regulator of airway branching. First, we tested if the HIF-1α TOS motif participated in epithelial-mesenchymal vascular signaling. mTORC1 activation by insulin significantly amplified HIF-1α activity at fetal Po2 (23 mmHg) in human bronchial epithelium (16HBE14o-) and induced vascular traits (Flk1, sprouting) in cocultured human embryonic lung mesenchyme (HEL-12469). This enhanced activation of HIF-1α by mTORC1 was abolished on expression of a HIF-1α (F99A) TOS-mutant and also suppressed vascular differentiation of HEL-12469 cocultures. Next, we determined if vasculogenesis in fetal lung involved regulation of mTORC1 by the FGF-10/FGFR2b/Spry2 pathway. Fetal airway epithelium displayed distinct mTORC1 activity in situ, and its hyperactivation by TSC1−/− knockout induced widespread VEGF expression and disaggregation of Tie2-positive vascular bundles. FGF-10-coated beads grafted into fetal lung explants from Tie2-LacZ transgenic mice induced localized vascular differentiation in the peripheral mesenchyme. In rat fetal distal lung epithelial (FDLE) cells cultured at fetal Po2, FGF-10 induced mTORC1 and amplified HIF-1α activity and VEGF secretion without induction of ERK1/2. This was accompanied by the formation of a complex between Spry2, the cCBL ubiquitin ligase, and the mTOR repressor, TSC2, which abolished GTPase activity directed against Rheb, the G protein inducer of mTORC1. Thus, mTORC1 links HIF-1α-driven vasculogenesis with the FGF-10/FGFR2b/Spry2 airway branching periodicity regulator.
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AHN, Se Jin, Seung Yup KIM, Ho Kyeong JEONG, Weui Bong JEONG, and Wan Suk YOO. "Enhancement of the TFS Method by Removing Bias Errors in FRF." JSME International Journal Series C 48, no. 1 (2005): 87–94. http://dx.doi.org/10.1299/jsmec.48.87.
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Bardi, Lara, Ryota Kanai, Daniela Mapelli, and Vincent Walsh. "TMS of the FEF Interferes with Spatial Conflict." Journal of Cognitive Neuroscience 24, no. 6 (June 2012): 1305–13. http://dx.doi.org/10.1162/jocn_a_00223.
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In the Simon task, a conflict arises because irrelevant spatial information competes for response selection either facilitating or interfering with performance. Responses are faster when stimulus and response position correspond than when they do not. The FEFs, which have long been characterized for their role in oculomotor control, are also involved in the control of visuospatial attention when eye movements are not required. This study was aimed at investigating whether the FEFs contribute to spatial conflict. Double-pulse TMS was applied to the FEF of either left or right hemisphere during the execution of a Simon task at different time windows after the onset of the visual stimulus. A suppression of the Simon effect was observed after stimulation of the FEF for stimuli appearing in the contralateral hemifield when TMS was applied to the left hemisphere after stimulus onset (0–40 and 40–80 msec). A reduction of the correspondence effect was observed after right FEF TMS for stimuli presented in the left visual hemifield when stimulation was delivered in the 80–120 msec range after stimulus onset. These outcomes indicate that the FEF play a critical role in encoding spatial attribute of a stimulus for response priming, which is the prerequisite for response conflict in the Simon task. Moreover, our finding that the left FEF have a dominant role during spatial conflict extends the idea of the left-hemisphere lateralization of the motor network in action selection by suggesting that the FEF may constitute part of this network.
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Taylor, P. C. J., A. C. Nobre, and M. F. S. Rushworth. "FEF TMS Affects Visual Cortical Activity." Cerebral Cortex 17, no. 2 (February 22, 2006): 391–99. http://dx.doi.org/10.1093/cercor/bhj156.
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Kenney, W. L., C. G. Tankersley, D. L. Newswanger, and S. M. Puhl. "Alpha 1-adrenergic blockade does not alter control of skin blood flow during exercise." American Journal of Physiology-Heart and Circulatory Physiology 260, no. 3 (March 1, 1991): H855—H861. http://dx.doi.org/10.1152/ajpheart.1991.260.3.h855.
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Human skin blood flow (SkBF) is controlled by both an alpha-adrenergic vasoconstrictor system and an active vasodilator system. During upright dynamic exercise, SkBF increases linearly with increasing body core temperature (Tc) until higher (i.e., greater than 38 degrees C) Tcs, beyond which little further increase in SkBF occurs. To examine the role of the two efferent control arms in this attenuated SkBF rise, we tested nine men (aged 25-53 yr) with and without (placebo) orally administered prazosin HCl (an alpha 1-adrenergic antagonist) during 1 h of moderate cycle exercise (100 W) in a warm (36 degrees C, 45% relative humidity) environment. Blockade of reflex vasoconstriction was verified via a cold challenge. During exercise, mean arterial pressure (MAP, brachial auscultation) was significantly lower (P less than 0.03) and heart rate significantly higher (P less than 0.02) during the prazosin trials; plasma catecholamine concentrations were unaffected. Neither esophageal temperature (Tes) nor mean skin temperature was affected by the drug during exercise. Forearm vascular conductance (FVC) was calculated from forearm blood flow (FBF, venous occlusion plethysmography) and MAP (FVC = FBF/MAP). FVC plotted as a function of time or Tes resulted in coincident response patterns for the placebo and prazosin treatments, reaching a plateau at a Tes of about 38 degrees C. The responses of the older men were not selectively altered by prazosin treatment, indicating that the lower FBF responses previously seen in older subjects during exercise in the heat does not appear to be the result of an increased alpha 1-adrenergic tone.(ABSTRACT TRUNCATED AT 250 WORDS)
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Silvanto, Juha, Nilli Lavie, and Vincent Walsh. "Stimulation of the Human Frontal Eye Fields Modulates Sensitivity of Extrastriate Visual Cortex." Journal of Neurophysiology 96, no. 2 (August 2006): 941–45. http://dx.doi.org/10.1152/jn.00015.2006.
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The precise role of frontal eye fields (FEF) in vision independent of their role in eye movements remains a matter of debate. One proposal is that the FEF exert top-down influences on the extrastriate visual cortex prior to eye movement preparation. Here we establish, by use of transcranial magnetic stimulation (TMS), that activity in the human FEFs has a direct effect on the sensitivity of extrastriate visual area MT/V5, and that the spatial organization of this top-down effect is lateralized in the human brain. We show that phosphene threshold—the TMS intensity required to elicit a visual perception—for MT/V5 stimulation changes as a function of the delay between the application of TMS over FEF and MT/V5. The effects were specific to the location and time of stimulation. Stimulation of FEF 20–40 ms prior to stimulation of MT/V5 decreased the intensity of MT/V5 stimulation required to elicit phosphenes: TMS of the right FEF changed the sensitivity of left and right MT/V5 whereas TMS of the left FEF changed the sensitivity only of the left MT/V5. Thus, the sensitivity of human extrastriate cortex is modulated by activity in the FEF.
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Kolka, Margaret A., and Lou A. Stephenson. "Effect of luteal phase elevation in core temperature on forearm blood flow during exercise." Journal of Applied Physiology 82, no. 4 (April 1, 1997): 1079–83. http://dx.doi.org/10.1152/jappl.1997.82.4.1079.
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Kolka, Margaret A., and Lou A. Stephenson. Effect of luteal phase elevation in core temperature on forearm blood flow during exercise. J. Appl. Physiol. 82(4): 1079–1083, 1997.—Forearm blood flow (FBF) as an index of skin blood flow in the forearm was measured in five healthy women by venous occlusion plethysmography during leg exercise at 80% peak aerobic power and ambient temperature of 35°C (relative humidity 22%; dew-point temperature 10°C). Resting esophageal temperature (Tes) was 0.3 ± 0.1°C higher in the midluteal than in the early follicular phase of the menstrual cycle ( P < 0.05). Resting FBF was not different between menstrual cycle phases. The Tes threshold for onset of skin vasodilation was higher (37.4 ± 0.2°C) in midluteal than in early follicular phase (37.0 ± 0.1°C; P < 0.05). The slope of the FBF to Tes relationship was not different between menstrual cycle phases (14.0 ± 4.2 ml ⋅ 100 ml−1 ⋅ min−1 ⋅ °C−1for early follicular and 16.3 ± 3.2 ml ⋅ 100 ml−1 ⋅ min−1 ⋅ °C−1for midluteal phase). Plateau FBF was higher during exercise in midluteal (14.6 ± 2.2 ml ⋅ 100 ml−1 ⋅ min−1 ⋅ °C−1) compared with early follicular phase (10.9 ± 2.4 ml ⋅ 100 ml−1 ⋅ min−1 ⋅ °C−1; P < 0.05). The attenuation of the increase in FBF to Tes occurred when Tes was 0.6°C higher and at higher FBF in midluteal than in early follicular experiments ( P < 0.05). In summary, the FBF response is different during exercise in the two menstrual cycle phases studied. After the attenuation of the increase in FBF and while Tes was still increasing, the greater FBF in the midluteal phase may have been due to the effects of increased endogenous reproductive endocrines on the cutaneous vasculature.
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O'Shea, Jacinta, Neil G. Muggleton, Alan Cowey, and Vincent Walsh. "Timing of Target Discrimination in Human Frontal Eye Fields." Journal of Cognitive Neuroscience 16, no. 6 (July 2004): 1060–67. http://dx.doi.org/10.1162/0898929041502634.
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Frontal eye field (FEF) neurons discharge in response to behaviorally relevant stimuli that are potential targets for saccades. Distinct visual and motor processes have been dissociated in the FEF of macaque monkeys, but little is known about the visual processing capacity of FEF in humans. We used double-pulse transcranial magnetic stimulation [(d)TMS] to investigate the timing of target discrimination during visual conjunction search. We applied dual TMS pulses separated by 40 msec over the right FEF and vertex. These were applied in five timing conditions to sample separate time windows within the first 200 msec of visual processing. (d)TMS impaired search performance, reflected in reduced d′ scores. This effect was limited to a time window between 40 and 80 msec after search array onset. These parameters correspond with single-cell activity in FEF that predicts monkeys' behavioral reports on hit, miss, false alarm, and correct rejection trials. Our findings demonstrate a crucial early role for human FEF in visual target discrimination that is independent of saccade programming.
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Han, Zhen Yu, Xiang Zhang, Hong Ya Fu, and Ya Zhou Sun. "Receptance Coupling for Micro-End-Milling." Advanced Materials Research 472-475 (February 2012): 2391–96. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.2391.
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Micro-end-milling tools are suitable for machining miniature parts which have complex shape. As the diameters of tools are too small, cannot directly obtain the frequency response functions (FRFs) through impact hammer test at tool tip. This paper employs Receptance Coupling method (RC), couple the tool tip’s FRFs with machine-toolholder system’s FRF, and then get the micro-end-milling tool’s FRF. Establish the coupling model, then finite element and hammer test of the blank gauge tools are used to obtain the coupling transfer functions (TFs). Then analyze the tool tip model by finite element, couple with the machine-toolholder system hammer test result and coupling transfer functions, finally the micro-end-milling tool’s FRFs are obtained. Through the hammer test of blank gauge tool, the effectiveness and feasibility of RC method are verified. The result shows that the RC method is accurate at micro-end-milling tool in steady state milling.
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Muggleton, Neil G., Roger Kalla, Chi-Hung Juan, and V. Walsh. "Dissociating the contributions of human frontal eye fields and posterior parietal cortex to visual search." Journal of Neurophysiology 105, no. 6 (June 2011): 2891–96. http://dx.doi.org/10.1152/jn.01149.2009.
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Imaging, lesion, and transcranial magnetic stimulation (TMS) studies have implicated a number of regions of the brain in searching for a target defined by a combination of attributes. The necessity of both frontal eye fields (FEF) and posterior parietal cortex (PPC) in task performance has been shown by the application of TMS over these regions. The effects of stimulation over these two areas have, thus far, proved to be remarkably similar and the only dissociation reported being in the timing of their involvement. We tested the hypotheses that 1) FEF contributes to performance in terms of visual target detection (possibly by modulation of activity in extrastriate areas with respect to the target), and 2) PPC is involved in translation of visual information for action. We used a task where the presence (and location) of the target was indicated by an eye movement. Task disruption was seen with FEF TMS (with reduced accuracy on the task) but not with PPC stimulation. When a search task requiring a manual response was presented, disruption with PPC TMS was seen. These results show dissociation of FEF and PPC contributions to visual search performance and that PPC involvement seems to be dependent on the response required by the task, whereas this is not the case for FEF. This supports the idea of FEF involvement in visual processes in a manner that might not depend on the required response, whereas PPC seems to be involved when a manual motor response to a stimulus is required.
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Grosbras, Marie-Hélène, and Tomáš Paus. "Transcranial Magnetic Stimulation of the Human Frontal Eye Field: Effects on Visual Perception and Attention." Journal of Cognitive Neuroscience 14, no. 7 (October 1, 2002): 1109–20. http://dx.doi.org/10.1162/089892902320474553.
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When looking at one object, human subjects can shift their attention to another object in their visual field without moving the eyes. Such shifts of attention activate the same brain regions as those involved in the execution of eye movements. Here we investigate the role of one of the main cortical oculomotor area, namely, the frontal eye field (FEF), in shifts of attention. We used transcranial magnetic stimulation (TMS), a technique known to disrupt transiently eye-movements preparation. We hypothesized that if the FEF is a necessary element in the network involved in shifting attention without moving the eyes, then TMS should also disrupt visuospatial attention. For each volunteer, we positioned the TMS coil over the probabilistic anatomical location of the FEF, and we verified that single pulses delayed eye movements. We then applied TMS during a visuospatial attention task. In this task, a central arrow directed shifts of attention and the subject responded by a keypress to a subsequent visual peripheral target without moving the eyes from the central fixation point. In a few trials, the cue was invalid or uninformative, yielding slower responses than when the cue was valid. We delivered single pulses either 53 msec before or 70 msec after target onset. Contrary to our prediction, the main effect of the stimulation was a decrease in reaction time when it was applied 53 msec before target onset. TMS over the left hemisphere facilitated responses to targets in the right hemifield only and for all cueing conditions, whereas TMS over the right hemisphere had a bilateral effect for valid and neutral but not invalid cueing. Thus, TMS interfered with shift of attention only in the case of right hemisphere stimulation: it increased the cost of invalid cueing. Our results suggest that TMS over the FEF facilitates visual detection, and thereby reduces reaction time. This finding provides new insights into the role of the human FEF in processing visual information. The functional asymmetry observed for both facilitation of visual detection and interference with shifts of attention provides further evidence for the dominance of the right hemisphere for those processes. Our results also underline that the disruptive or facilitative effect of TMS over a given region depends upon the behavioral context.
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Vroman, N. B., W. S. Beckett, S. Permutt, and S. Fortney. "Effect of positive-pressure breathing on cardiovascular and thermoregulatory responses to exercise." Journal of Applied Physiology 58, no. 3 (March 1, 1985): 876–81. http://dx.doi.org/10.1152/jappl.1985.58.3.876.
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Five healthy male volunteers performed 20 min of both seated and supine cycle-ergometer exercise (intensity, 50% maximal O2 uptake) in a warm environment (Tdb = 30 degrees C, relative humidity = 40–50%) with and without breathing 10 cmH2O of continuous positive airway pressure (CPAP). The final esophageal temperature (Tes) at the end of 20 min of seated exercise was significantly higher during CPAP (mean difference = 0.18 +/- 0.04 degree C, P less than 0.05) compared with control breathing (C). The Tes threshold for forearm vasodilation was significantly higher (P less than 0.05) during seated CPAP exercise than C (C = 37.16 +/- 0.13 degrees C, CPAP = 37.38 + 0.12 degree C). The highest forearm blood flow (FBF) at the end of exercise was significantly lower (P less than 0.05) during seated exercise with CPAP (mean +/- SE % difference from C = -30.8 +/- 5.8%). During supine exercise, there were no significant differences in the Tes threshold, highest FBF, or final Tes with CPAP compared with C. The added strain on the cardiovascular system produced by CPAP during seated exercise in the heat interacts with body thermoregulation as evidenced by elevated vasodilation thresholds, reduced peak FBF, and slightly higher final esophageal temperatures.
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Kolka, M. A., L. A. Stephenson, A. E. Allan, and P. B. Rock. "Atropine-induced cutaneous vasodilation decreases esophageal temperature during exercise." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 257, no. 5 (November 1, 1989): R1089—R1095. http://dx.doi.org/10.1152/ajpregu.1989.257.5.r1089.
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Four healthy adult males volunteered for this study, which followed informed-consent procedures administered by our local Human Use Committee. Esophageal (Tes) and mean skin (Tsk, eight site) temperatures, forearm sweating rate (ms), metabolism (M), heart rate (HR), and forearm blood flow (FBF) were measured at rest and during forearm blood flow (FBF) were measured at rest and during exercise [55% oxygen consumption (Vo2) peak] during control experiments and after 2 mg im atropine (ATR). Experiments were randomized and separated by at least 72 h. ATR increased heart rate at rest by 15 beats/min and during exercise by 24 beats/min. ATR decreased whole body sweating by 57%. All eight local skin temperatures were higher in ATR than in control. Tsk was 32.6 degrees C in ATR and 31.0 degrees C in control (P less than 0.01). During exercise, ATR increased vasodilation of the forearm compared with control. The slope of FBF to Tes increased over 300% in ATR experiments compared with control (P less than 0.05). The higher sensible heat flux from this vasodilation decreased Tes during exercise, which further decreased sweating. Skin blood flow remained elevated as Tes decreased, suggesting that local vasodilatory factors promoted atropine-induced cutaneous vasodilation.
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Duecker, Felix, Elia Formisano, and Alexander T. Sack. "Hemispheric Differences in the Voluntary Control of Spatial Attention: Direct Evidence for a Right-Hemispheric Dominance within Frontal Cortex." Journal of Cognitive Neuroscience 25, no. 8 (August 2013): 1332–42. http://dx.doi.org/10.1162/jocn_a_00402.
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Lesion studies in neglect patients have inspired two competing models of spatial attention control, namely, Heilman's “hemispatial” theory and Kinsbourne's “opponent processor” model. Both assume a functional asymmetry between the two hemispheres but propose very different mechanisms. Neuroimaging studies have identified a bilateral dorsal frontoparietal network underlying voluntary shifts of spatial attention. However, lateralization of attentional processes within this network has not been consistently reported. In the current study, we aimed to provide direct evidence concerning the functional asymmetry of the right and left FEF during voluntary shifts of spatial attention. To this end, we applied fMRI-guided neuronavigation to disrupt individual FEF activation foci with a longer-lasting inhibitory patterned TMS protocol followed by a spatial cueing task. Our results indicate that right FEF stimulation impaired the ability of shifting spatial attention toward both hemifields, whereas the effects of left FEF stimulation were limited to the contralateral hemifield. These results provide strong direct evidence for right-hemispheric dominance in spatial attention within frontal cortex supporting Heilman's “hemispatial” theory. This complements previous TMS studies that generally conform to Kinsbourne's “opponent processor” model after disruption of parietal cortex, and we therefore propose that both theories are not mutually exclusive.
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Kolka, M. A., and L. A. Stephenson. "Exercise thermoregulation after prolonged wakefulness." Journal of Applied Physiology 64, no. 4 (April 1, 1988): 1575–79. http://dx.doi.org/10.1152/jappl.1988.64.4.1575.
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The effect of 33 h of wakefulness on the control of forearm cutaneous blood flow and forearm sweating during exercise was studied in three men and three women. Subjects exercised for 30 min at 60% peak O2 consumption while seated behind a cycle ergometer (Ta = 35 degrees C, Pw = 1.0 kPa). We measured esophageal temperature (Tes), mean skin temperature, and arm sweating continuously and forearm blood flow (FBF) as an index of skin blood flow, twice each minute by venous occlusion plethysmography. During steady-state exercise, Tes was unchanged by sleep loss. The sensitivity of FBF to Tes was depressed an average of 30% (P less than 0.05) after 33 h of wakefulness with a slight decrease (-0.15 degrees C, P less than 0.05) in the core temperature threshold for vasodilatory onset. Sleep loss did not alter the Tes at which the onset of sweating occurred; however, sensitivity of arm sweating to Tes tended to be lower but was not significant. Arm skin temperature was not different between control and sleep loss experiments. Reflex cutaneous vasodilation during exercise appeared to be reduced by both central and local factors after 33 h of wakefulness
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Smolander, J., J. Saalo, and O. Korhonen. "Effect of work load on cutaneous vascular response to exercise." Journal of Applied Physiology 71, no. 4 (October 1, 1991): 1614–19. http://dx.doi.org/10.1152/jappl.1991.71.4.1614.
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The purpose of the present study was to examine whether intensity of exercise affects skin blood flow response to exercise. For this purpose, six healthy men cycled, in a random order on different days, for 15 min at 50, 60, 70, 80, and 90% of their maximum oxygen consumption (VO2max) at a room temperature of 25 degrees C. At the end of exercise, esophageal temperature (Tes) averaged 37.4 +/- 0.2, 37.7 +/- 0.2, 37.9 +/- 0.2, 38.6 +/- 0.3, and 38.9 +/- 0.4 degrees C (SE) at the 50, 60, 70, 80, and 90% work loads, respectively. At the two highest work loads, no steady state was observed in Tes. Skin blood flow was estimated by measuring forearm blood flow (FBF) with strain-gauge plethysmography and by laser-Doppler flowmetry on the upper back. Both techniques showed that skin blood flow response to rising Tes was markedly reduced at the 90% work load compared with other work loads. At the end of exercise, FBF averaged 7.5 +/- 1.7, 10.7 +/- 3.1, 9.6 +/- 2.1, 11.3 +/- 2.6, and 5.4 +/- 1.3 (SE) ml.min-1.100 ml-1 (P less than 0.01) at the 50, 60, 70, 80, and 90% VO2max work loads, respectively. The corresponding values for Tes threshold for cutaneous vasodilation (FBF) were 37.42 +/- 0.16, 37.48 +/- 0.13, 37.59 +/- 0.13, 37.79 +/- 0.19, and 38.20 +/- 0.22 degrees C (P less than 0.05) at 50, 60, 70, 80, and 90% VO2max, respectively. In two subjects, no cutaneous vasodilation was observed at the 90% work load.(ABSTRACT TRUNCATED AT 250 WORDS)
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Nose, H., G. W. Mack, X. R. Shi, K. Morimoto, and E. R. Nadel. "Effect of saline infusion during exercise on thermal and circulatory regulations." Journal of Applied Physiology 69, no. 2 (August 1, 1990): 609–16. http://dx.doi.org/10.1152/jappl.1990.69.2.609.
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To quantify the effect of an acute increase in plasma volume (PV) on forearm blood flow (FBF), heart rate (HR), and esophageal temperature (Tes) during exercise, we studied six male volunteers who exercised on a cycle ergometer at 60% of maximal aerobic power for 50 min in a warm [(W), 30 degrees C, less than 30% relative humidity (rh)] or cool environment [(C), 22 degrees C, less than 30% rh] with isotonic saline infusion [Inf(+)] or without infusion [Inf(-)]. The infusion was performed at a constant rate of 0.29 ml.kg body wt-1.min-1 for 20-50 min of exercise to mimic fluid intake during exercise. PV decreased by approximately 5 ml/kg body wt within the first 10 min of exercise in all protocols. Therefore, PV in Inf(-) was maintained at the same reduced level by 50 min of exercise in both ambient temperatures, whereas PV in Inf(+) increased toward the preexercise level and recovered approximately 4.5 ml/kg body wt by 50 min in both temperatures. The restoration of PV during exercise suppressed the HR increase by 6 beats/min at 50 min of exercise in W; however, infusion had no effect on HR in C. In W, FBF in Inf(+) continued to increase linearly as Tes rose to 38.1 degrees C by the end of exercise, whereas FBF in Inf(-) plateaued when Tes reached approximately 37.7 degrees C. The infusion in C had only a minor effect on FBF.(ABSTRACT TRUNCATED AT 250 WORDS)
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Scheuer, Kevin, Jason Holmes, Evgeny Galyaev, David Blyth, and Ricardo Alarcon. "Radiation Effects on FR4 Printed Circuit Boards." IEEE Transactions on Nuclear Science 67, no. 8 (August 2020): 1846–51. http://dx.doi.org/10.1109/tns.2020.2996536.
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van Koningsbruggen, M., P. Downing, and R. Rafal. "The effect of theta TMS over the FEF on fMRI activations." Journal of Vision 9, no. 8 (March 23, 2010): 378. http://dx.doi.org/10.1167/9.8.378.
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Krok, Grzegorz, Bartłomiej Kraszewski, and Krzysztof Stereńczak. "Application of terrestrial laser scanning in forest inventory – an overview of selected issues." Forest Research Papers 81, no. 4 (December 1, 2020): 175–94. http://dx.doi.org/10.2478/frp-2020-0021.
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AbstractPrecise determination of forest resources is one of the most important tasks in conducting sustainable forest management. Accurate information about the forest’s resources allows for a better planning of current and future management as well as conservation activities. Such precise information is needed by both, individual forest managers and for developing the national forest policy. In recent years, interest in the use of remote sensing in forest inventory has significantly increased. Remote sensing allows for non-invasive measurements and the automation of data processing. The most accurate source of remote sensing data at the level of the sample plot is terrestrial laser scanning (TLS). Its use in forest inventory has been studied for about two decades.This paper aims to introduce studies on state of the art TLS technology as well as provide an overview of research conducted in stands within the temperate climate zone. This article furthermore discusses issues such as TLS data acquisition, data processing and presents results for the estimation of tree biometric features.
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Szczepankiewicz, Elżbieta Izabela, and Anna Wójtowicz. "The model of the risk register in the units of public finance sector." Zeszyty Naukowe Uniwersytetu Szczecińskiego Finanse, Rynki Finansowe, Ubezpieczenia 2015, no. 76/2 (September 30, 2015): 219–39. http://dx.doi.org/10.18276/frfu.2015.76/2-18.
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Duecker, Felix, Martin A. Frost, Tom A. de Graaf, Britta Graewe, Christianne Jacobs, Rainer Goebel, and Alexander T. Sack. "The Cortex-based Alignment Approach to TMS Coil Positioning." Journal of Cognitive Neuroscience 26, no. 10 (October 2014): 2321–29. http://dx.doi.org/10.1162/jocn_a_00635.
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TMS allows noninvasive manipulation of brain activity in healthy participants and patients. The effectiveness of TMS experiments critically depends on precise TMS coil positioning, which is best for most brain areas when a frameless stereotactic system is used to target activation foci based on individual fMRI data. From a purely scientific perspective, individual fMRI-guided TMS is thus the method of choice to ensure optimal TMS efficiency. Yet, from a more practical perspective, such individual functional data are not always available, and therefore alternative TMS coil positioning approaches are often applied, for example, based on functional group data reported in Talairach coordinates. We here propose a novel method for TMS coil positioning that is based on functional group data, yet only requires individual anatomical data. We used cortex-based alignment (CBA) to transform individual anatomical data to an atlas brain that includes probabilistic group maps of two functional regions (FEF and hMT+/V5). Then, these functional group maps were back-transformed to the individual brain anatomy, preserving functional–anatomical correspondence. As a proof of principle, the resulting CBA-based functional targets in individual brain space were compared with individual FEF and hMT+/V5 hotspots as conventionally localized with individual fMRI data and with targets based on Talairach coordinates as commonly done in TMS research in case only individual anatomical data are available. The CBA-based approach significantly improved localization of functional brain areas compared with traditional Talairach-based targeting. Given the widespread availability of CBA schemes and preexisting functional group data, the proposed procedure is easy to implement and at no additional measurement costs. However, the accuracy of individual fMRI-guided TMS remains unparalleled, and the CBA-based approach should only be the method of choice when individual functional data cannot be obtained or experimental factors argue against it.
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Lebedev, D. A., N. V. Timkina, T. L. Karonova, A. T. Andreeva, M. A. Kokina, A. L. Grigorieva, A. Yu Babenko, and E. N. Grineva. "Effect of empagliflozin on phosphorus and calcium metabolism in patients with type 2 diabetes mellitus with preserved kidney function." Osteoporosis and Bone Diseases 24, no. 1 (August 25, 2021): 4–9. http://dx.doi.org/10.14341/osteo12718.
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Background: Sodium glucose co-transporter type 2 inhibitors (iSGLT2) are antihyperglycemic drugs approved for the treatment of type 2 diabetes mellitus (T2DM). Clinical trials with these drugs have shown evidence of an increased risk of fractures and an effect on phosphorus, vitamin D and parathyroid hormone (PTH) levels.Aim: The aim of this study was to investigate the effect of the most selective iSGLT2 empagliflozin on the calcium and phosphorus metabolism in patients with T2DM and preserved kidney function.Materials and methods: Thirty-nine T2DM patients were received empagliflozin 10 mg in addition to their antihyperglycemic drugs for 12 weeks. Before starting treatment, a dual-energy X-ray absorptiometry (DXA) with an assessment of the trabecular bone score (TBS) was performed. The concentration of phosphorus (P), total (tCa) and ionized calcium (Ca++), fibroblast growth factor 23 (FGF-23), 25(OH)D and PTH were assessed.Results: According to the DXA results, only 2 patients had osteoporosis, 10 (25.6%) patients had bone mineral density (BMD) values below 1.35 g /cm2 on the TCI scale. Treatment with empagliflozin for 12 weeks was lead to significant increase in FGF-23. Compared to the baseline level, there were no statistically significant differences in the concentrations of P, oCa, Ca++, PTH and 25(OH)D after 12 weeks of treatment. The level of FGF-23 did not correlate with the level of glomerular filtration rate either before or after treatment (r = 0.31, p = 0.27 and r = 0.39, p = 0.55, respectively). In addition, baseline BMD adjusted for TBS and baseline 25(OH)D did not correlate with Ca, F, FGF-23, and PTH concentrations (p>0.05).Conclusion: Thus, empagliflozin has increased the level of FGF-23 without significant changes in the concentration of phosphorus, calcium, 25 (OH) D, and PTH after 12 weeks of treatment in patients with T2DM and preserved renal function. The obtained data confirmed the necessity to assess the TBS in patients with T2DM, because it’s provide additional information on the quality of bone tissue.
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Muggleton, Neil G., Chiao-Yun Chen, Ovid J. L. Tzeng, Daisy L. Hung, and Chi-Hung Juan. "Inhibitory Control and the Frontal Eye Fields." Journal of Cognitive Neuroscience 22, no. 12 (December 2010): 2804–12. http://dx.doi.org/10.1162/jocn.2010.21416.
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Inhibitory control mechanisms are important in a range of behaviors to prevent execution of motor acts which, having been planned, are no longer necessary. Ready examples of this can be seen in a range of sports, such as cricket and baseball, where the choice between execution or inhibition of a bat swing must be made in a brief time interval. The role of the FEFs, an area typically described in relation to eye movement functions but also involved in visual processes, was investigated in an inhibitory control task using transcranial magnetic stimulation (TMS). A stop signal task with manual responses was used, providing measures of impulsivity and inhibitory control. TMS over FEF had no effect on response generation (impulsivity, indexed by go signal RT) but disrupted inhibitory control (indexed by stop signal RT). This is the first demonstration of a role for FEF in this type of task in normal subjects in a task which did not require eye movements and complements previous TMS findings of roles for pre-SMA and inferior frontal gyrus (IFG) in inhibitory control.
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Nagashima, Kei, Hiroshi Nose, Akira Takamata, and Taketoshi Morimoto. "Effect of continuous negative-pressure breathing on skin blood flow during exercise in a hot environment." Journal of Applied Physiology 84, no. 6 (June 1, 1998): 1845–51. http://dx.doi.org/10.1152/jappl.1998.84.6.1845.
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To assess the impact of continuous negative-pressure breathing (CNPB) on the regulation of skin blood flow, we measured forearm blood flow (FBF) by venous-occlusion plethysmography and laser-Doppler flow (LDF) at the anterior chest during exercise in a hot environment (ambient temperature = 30°C, relative humidity = ∼30%). Seven male subjects exercised in the upright position at an intensity of 60% peak oxygen consumption rate for 40 min with and without CNPB after 20 min of exercise. The esophageal temperature (Tes) in both conditions increased to 38.1°C by the end of exercise, without any significant differences between the two trials. Mean arterial pressure (MAP) increased by ∼15 mmHg by 8 min of exercise, without any significant difference between the two trials before CNPB. However, CNPB reduced MAP by ∼10 mmHg after 24 min of exercise ( P < 0.05). The increase in FBF and LDF in the control condition leveled off after 18 min of exercise above a Tes of 37.7°C, whereas in the CNPB trial the increase continued, with a rise in Tes despite the decrease in MAP. These results suggest that CNPB enhances vasodilation of skin above a Tes of ∼38°C by stretching intrathoracic baroreceptors such as cardiopulmonary baroreceptors.
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Thickbroom, G. W., R. Stell, and F. L. Mastaglia. "Localisation of the frontal eye field (FEF) using transcranial magnetic stimulation (TMS)." Electroencephalography and Clinical Neurophysiology 102, no. 5 (May 1997): P62—P63. http://dx.doi.org/10.1016/s0921-884x(97)88252-5.
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Dugué, Laura, Alexy-Assaf Beck, Philippe Marque, and Rufin VanRullen. "Contribution of FEF to Attentional Periodicity during Visual Search: A TMS Study." eneuro 6, no. 3 (May 2019): ENEURO.0357–18.2019. http://dx.doi.org/10.1523/eneuro.0357-18.2019.
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Van Ettinger-Veenstra, H. M., W. Huijbers, T. P. Gutteling, M. Vink, J. L. Kenemans, and S. F. W. Neggers. "fMRI-Guided TMS on Cortical Eye Fields: The Frontal But Not Intraparietal Eye Fields Regulate the Coupling Between Visuospatial Attention and Eye Movements." Journal of Neurophysiology 102, no. 6 (December 2009): 3469–80. http://dx.doi.org/10.1152/jn.00350.2009.
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It is well known that parts of a visual scene are prioritized for visual processing, depending on the current situation. How the CNS moves this focus of attention across the visual image is largely unknown, although there is substantial evidence that preparation of an action is a key factor. Our results support the view that direct corticocortical feedback connections from frontal oculomotor areas to the visual cortex are responsible for the coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging (fMRI)–guided transcranial magnetic stimulation (TMS) was applied to the frontal eye fields (FEFs) and intraparietal sulcus (IPS). A single pulse was delivered 60, 30, or 0 ms before a discrimination target was presented at, or next to, the target of a saccade in preparation. Results showed that the known enhancement of discrimination performance specific to locations to which eye movements are being prepared was enhanced by early TMS on the FEF contralateral to eye movement direction, whereas TMS on the IPS resulted in a general performance increase. The current findings indicate that the FEF affects selective visual processing within the visual cortex itself through direct feedback projections.
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Lim, R. W., B. C. Varnum, T. G. O'Brien, and H. R. Herschman. "Induction of tumor promotor-inducible genes in murine 3T3 cell lines and tetradecanoyl phorbol acetate-nonproliferative 3T3 variants can occur through protein kinase C-dependent and -independent pathways." Molecular and Cellular Biology 9, no. 4 (April 1989): 1790–93. http://dx.doi.org/10.1128/mcb.9.4.1790.
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We isolated a group of genes that are rapidly and transiently induced in 3T3 cells by tetradecanoyl phorbol acetate (TPA). These genes are called TIS genes (for TPA-inducible sequences). Epidermal growth factor (EGF), fibroblast growth factor (FGF), and TPA activated TIS gene expression with similar induction kinetics. TPA pretreatment to deplete protein kinase C activity did not abolish the subsequent induction of TIS gene expression by epidermal growth factor or fibroblast growth factor; both peptide mitogens can activate TIS genes through a protein kinase C-independent pathway(s). We also analyzed TIS gene expression in three TPA-nonproliferative variants (3T3-TNR2, 3T3-TNR9, and A31T6E12A). The results indicate that (i) modulation of a TPA-responsive sodium-potassium-chloride transport system is not necessary for TIS gene induction either by TPA or by other mitogens and (ii) TIS gene induction is not sufficient to guarantee a proliferative response to mitogenic stimulation.
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Lim, R. W., B. C. Varnum, T. G. O'Brien, and H. R. Herschman. "Induction of tumor promotor-inducible genes in murine 3T3 cell lines and tetradecanoyl phorbol acetate-nonproliferative 3T3 variants can occur through protein kinase C-dependent and -independent pathways." Molecular and Cellular Biology 9, no. 4 (April 1989): 1790–93. http://dx.doi.org/10.1128/mcb.9.4.1790-1793.1989.
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We isolated a group of genes that are rapidly and transiently induced in 3T3 cells by tetradecanoyl phorbol acetate (TPA). These genes are called TIS genes (for TPA-inducible sequences). Epidermal growth factor (EGF), fibroblast growth factor (FGF), and TPA activated TIS gene expression with similar induction kinetics. TPA pretreatment to deplete protein kinase C activity did not abolish the subsequent induction of TIS gene expression by epidermal growth factor or fibroblast growth factor; both peptide mitogens can activate TIS genes through a protein kinase C-independent pathway(s). We also analyzed TIS gene expression in three TPA-nonproliferative variants (3T3-TNR2, 3T3-TNR9, and A31T6E12A). The results indicate that (i) modulation of a TPA-responsive sodium-potassium-chloride transport system is not necessary for TIS gene induction either by TPA or by other mitogens and (ii) TIS gene induction is not sufficient to guarantee a proliferative response to mitogenic stimulation.
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Shiraki, K., S. Sagawa, M. K. Yousef, N. Konda, and K. Miki. "Physiological responses of aged men to head-up tilt during heat exposure." Journal of Applied Physiology 63, no. 2 (August 1, 1987): 576–81. http://dx.doi.org/10.1152/jappl.1987.63.2.576.
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The effects of age on cardiovascular and thermoregulatory responses to passive tilting were investigated using six old (61–73 yr) and 10 young (21–39 yr) unacclimatized men. Experiments were carried out at 26 degrees C and after exposure to 40 degrees C and 40% relative humidity for 105 min. Continuous measurements of esophageal (Tes) and mean skin (Tsk) temperatures and heart rate (HR) were recorded. Other variables studied included blood pressure (BP), forearm blood flow (FBF), and cardiac output (CO), which were measured at 4- to 5-min intervals. Measurements were made in the supine position and after 70 degrees head-up tilt for 15 min. Cardioacceleration during the tilt test was greater in the young men than in the old. Other cardiovascular responses of the old men to orthostatism were qualitatively similar to that of the young except for FBF and forearm vascular conductance. The old men did not show significant changes in FBF during tilting, suggesting a deterioration in the sympathetic nervous reflex in the aged. However, other circulatory adaptations seemed to overcome this deficiency resulting in orthostatic tolerance similar to that of the young. During head-up tilt at 26 and 40 degrees C, Tes of both age groups increased. This may reflect a decrease in conductive heat transfer presumably due to diminished blood flow to the periphery.
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Ronconi, L., D. Basso, S. Gori, and A. Facoetti. "Single-pulse TMS on the FEF area induces a "narrow" focus of attention." Journal of Vision 12, no. 9 (August 10, 2012): 558. http://dx.doi.org/10.1167/12.9.558.
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Chang, R. T., G. P. Lambert, P. L. Moseley, F. K. Chapler, and C. V. Gisolfi. "Effect of estrogen supplementation on exercise thermoregulation in premenopausal women." Journal of Applied Physiology 85, no. 6 (December 1, 1998): 2082–88. http://dx.doi.org/10.1152/jappl.1998.85.6.2082.
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This study examined the effects of 3 days of estrogen supplementation (ES) on thermoregulation during exercise in premenopausal (20–39 yr) adult women during the follicular phase of the menstrual cycle. Subjects (11 control, 10 experimental) performed upright cycle ergometer exercise at 60% of maximal O2 consumption in a neutral environment (25°C, 30% relative humidity) for 20 min. Subjects were given placebo (P) or β-estradiol (2 mg/tablet, 3 tablets/day for 3 days). All experiments were conducted between 6:30 and 9:00 AM after ingestion of the last tablet. Heart rate, forearm blood flow (FBF), mean skin temperature, esophageal temperature (Tes), and forearm sweat rate were measured. Blood analysis for estrogen and progesterone reflected the follicular phase of the menstrual cycle. Maximal O2 consumption (37.1 ± 6.2 in P vs. 38.4 ± 6.3 ml ⋅ kg−1 ⋅ min−1in ES) and body weight-to-surface area ratio (35.58 ± 2.85 in P vs. 37.3 ± 2.7 in ES) were similar between groups. Synthesis of 70-kDa heat shock protein was not induced by 3 days of ES. Neither the threshold for sweating (36.97 ± 0.15 in P vs. 36.90 ± 0.22°C in ES), the threshold for an increase in FBF (37.09 ± 0.22 in P vs. 37.17 ± 0.26°C in ES), the slope of sweat rate-Tes relationship (0.42 ± 0.16 in P vs. 0.41 ± 0.17 in ES), nor the FBF-Tes relationship (10.04 ± 4.4 in P vs. 9.61 ± 3.46 in ES) was affected ( P > 0.05) by 3 days of ES. We conclude that 3 days of ES by young adult women in the follicular phase of their menstrual cycle have no effect on heat transfer to the skin, heat dissipation by evaporative cooling, or leukocyte synthesis of 70-kDa heat shock protein.
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Tankersley, C. G., J. Smolander, W. L. Kenney, and S. M. Fortney. "Sweating and skin blood flow during exercise: effects of age and maximal oxygen uptake." Journal of Applied Physiology 71, no. 1 (July 1, 1991): 236–42. http://dx.doi.org/10.1152/jappl.1991.71.1.236.
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Individuals greater than or equal to 60 yr of age are more susceptible to hyperthermia than younger people. However, the mechanisms involved remain unclear. To gain further insight, we examined the heat loss responses of 7 young (24–30 yr) and 13 older (58–74 yr) men during 20 min of cycle exercise [67.5% maximal O2 uptake (VO2max)] in a warm environment (30 degrees C, 55% relative humidity). Forearm blood flow (FBF) and chest sweat rate (SR) were plotted as a function of the weighted average of mean skin and esophageal temperatures [Tes(w)] during exercise. The sensitivity and threshold for each response were defined as the slope and Tes(w) at the onset of the response, respectively. When the young sedentary men were compared with a subgroup (n = 7) of the older physically active men with similar VO2max, the SR and FBF responses of the two groups did not differ significantly. However, when the young men were compared with a subgroup of older sedentary men with a similar maximal O2 pulse, the SR and FBF sensitivities were significantly reduced by 62 and 40%, respectively. These findings suggest that during a short exercise bout either 1) there is no primary effect of aging on heat loss responses but, rather, changes are associated with the age-related decrease in VO2max or 2) the decline in heat loss responses due to aging may be masked by repeated exercise training.
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Taylor, Paul C. J., Neil G. Muggleton, Roger Kalla, Vincent Walsh, and Martin Eimer. "TMS of the right angular gyrus modulates priming of pop-out in visual search: combined TMS-ERP evidence." Journal of Neurophysiology 106, no. 6 (December 2011): 3001–9. http://dx.doi.org/10.1152/jn.00121.2011.
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During priming of pop-out, performance at discriminating a pop-out feature target in visual search is affected by whether the target on the previous trial was defined by the same feature as on the upcoming trial. Recent studies suggest that priming of pop-out relies on attentional processes. With the use of simultaneous, combined transcranial magnetic stimulation and event-related potential recording (TMS-ERP), we tested for any critical role of the right angular gyrus (rANG) and left and right frontal eye fields (FEFs)—key attentional sites—in modulating both performance and the ERPs evoked by such visual events. Intertrial TMS trains were applied while participants discriminated the orientation of a color pop-out element in a visual search array. rANG TMS disrupted priming of pop-out, reducing reaction time costs on switch trials and speeding responses when the color of the pop-out target switched. rANG TMS caused a negativity in the ERP elicited in response to the visual stimulus array, starting 210 ms after stimulus onset. Both behavioral and ERP effects were apparent only after rANG TMS, on switch trials, and when the target in the visual search array was presented in the left visual field, with no effects after left or right FEF TMS. These results provide evidence for an attentional reorienting mechanism, which originates in the rANG and is modulated by the implicit memory of the previous trial. The rANG plays a causal role on switch trials during priming of pop-out by interacting with visual processing, particularly in the ipsilateral hemisphere representing the contralateral hemifield.
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Pescatello, L. S., G. W. Mack, C. N. Leach, and E. R. Nadel. "Effect of beta-adrenergic blockade on thermoregulation during exercise." Journal of Applied Physiology 62, no. 4 (April 1, 1987): 1448–52. http://dx.doi.org/10.1152/jappl.1987.62.4.1448.
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To resolve conflicting reports concerning the effects of beta-blockade (BB) on thermoregulatory reflexes during exercise, we studied six fit men during 40 min of cycle ergometer exercise at 60% maximum O2 consumption at ambient temperatures of 22 and 32 degrees C. Two hours before exercise, each subject ingested a capsule containing either 80 mg of propranolol or placebo in single-blind fashion. Heart rate at 40 min of exercise was reduced (P less than 0.01) from 125 to 103 beats min at 22 degrees C and 137 to 104 beats min at 32 degrees C, demonstrating effective BB. After 40 min of exercise, esophageal temperature (Tes) was elevated with BB (P less than 0.05) from 37.66 +/- 0.04 to 38.14 +/- 0.03 and 38.13 +/- 0.04 to 38.41 +/- 0.04 degrees C at 22 and 32 degrees C, respectively. The elevated Tes resulted from a reduced core-to-skin heat flux at both temperatures, indicated by a reduction in the slope of the forearm blood flow (FBF)-Tes relationship, and a decrease in maximal FBF. Systolic blood pressure was decreased 20 mmHg with BB (P less than 0.01), whereas diastolic blood pressure was unchanged, reducing arterial pulse pressure (PP). Because PP was decreased and cardiac filling pressure was presumably not reduced (since cardiac stroke volume was elevated), we suggest that at least a part of the relative increase in peripheral vasomotor tone during BB was the consequence of reduced sinoaortic baroreceptor stimulation.
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Eide, Marianne Leikvoll, and May-Britt Revheim Brekke. "Fortelling fra praksis som inngang til pedagogisk kunnskap." Högre utbildning 11, no. 2 (2021): 14. http://dx.doi.org/10.23865/hu.v11.2754.
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Denne artikkelen bygger på utprøving av praksisfortelling som studentaktiv læringsform. Noen av funnene, og erfaringene vi har gjort oss, trekkes her frem for å belyse hvordan fortellingen kan bidra til å skape sammenhenger mellom teori og praksis, sett fra vårt perspektiv som lærerutdannere. Fortelling fra praksis kan gjøre undervisningen på campus relevant og meningsfull for studentene når det tas utgangspunkt i studentenes egne erfaringer. Ulike kontekster møtes, og erfaringer kan deles på tvers av disse. I studentenes klasserom kan fortellingene endres og videreutvikles, og forforståelser og vanetenkning kan bli utfordret. For å kunne gripe fatt i, og spinne videre på, fortellinger og fortolkninger i det de kommer i undervisningen, kreves det nærvær og oppmerksom tilstedeværelse av faglærer.
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Perucca Orfei, Carlotta, Marco Viganò, John R. Pearson, Alessandra Colombini, Paola De Luca, Enrico Ragni, Leonor Santos-Ruiz, and Laura De Girolamo. "In Vitro Induction of Tendon-Specific Markers in Tendon Cells, Adipose- and Bone Marrow-Derived Stem Cells is Dependent on TGFβ3, BMP-12 and Ascorbic Acid Stimulation." International Journal of Molecular Sciences 20, no. 1 (January 3, 2019): 149. http://dx.doi.org/10.3390/ijms20010149.
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Mesenchymal Stem Cells (MSCs) and tissue-specific progenitors have been proposed as useful tools for regenerative medicine approaches in bone, cartilage and tendon-related pathologies. The differentiation of cells towards the desired, target tissue-specific lineage has demonstrated advantages in the application of cell therapies and tissue engineering. Unlike osteogenic and chondrogenic differentiation, there is no consensus on the best tenogenic induction protocol. Many growth factors have been proposed for this purpose, including BMP-12, b-FGF, TGF-β3, CTGF, IGF-1 and ascorbic acid (AA). In this study, different combinations of these growth factors have been tested in the context of a two-step differentiation protocol, in order to define their contribution to the induction and maintenance of tendon marker expression in adipose tissue and bone marrow derived MSCs and tendon cells (TCs), respectively. Our results demonstrate that TGF-β3 is the main inducer of scleraxis, an early expressed tendon marker, while at the same time inhibiting tendon markers normally expressed later, such as decorin. In contrast, we find that decorin is induced by BMP-12, b-FGF and AA. Our results provide new insights into the effect of different factors on the tenogenic induction of MSCs and TCs, highlighting the importance of differential timing in TGF-β3 stimulation.
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Gutman, Mary. "Immediate and Long-Term Effects of “Learning By Teaching” on Knowledge of Cognition." Journal of Education and Learning 6, no. 4 (April 27, 2017): 1. http://dx.doi.org/10.5539/jel.v6n4p1.
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Learning By Teaching (LBT) programs for pre-service teachers in two different environments (technological and face-to-face) were compared using 100 pre-service teachers as subjects. Both programs were based on the IMPROVE instructional method which provides explicit metacognitive steps for LBT with a dual perspective (2P): that of the teacher and that of the learner. The dependent variables Knowledge of Cognition (KC) in learning and in teaching were tested for their immediate and long-term effects in a Technology-Based System group (TBS+2P), and in a Face-to-Face group (F2F+2P). Post-test results of KC have indicated that the TBS+2P group had shown a higher level of conditional and procedural knowledge of teaching. The TBS+2P group has also performed better in measures of long-term effects of declarative knowledge in teaching. Both theoretical and practical implications of this study are discussed.
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Moss, Tyler J., Jordi Rodon Ahnert, Holly D. Oakley, Michael Kahle, Daniel D. Karp, Shubham Pant, Jeena Jacob, et al. "Baseline cfDNA characteristics and evolution of cfDNA profile during treatment with selective FGFR inhibitor TAS-120." Journal of Clinical Oncology 37, no. 15_suppl (May 20, 2019): 3056. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.3056.
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3056 Background: There is an increasing role for cfDNA in monitoring response and mechanisms of resistance. We performed cfDNA analysis in a subset of patients enrolled on a Phase I trial with an irreversible, selective FGFR1-4 inhibitor, TAS-120. Methods: 58 plasma samples from 17 patients (13 with cholangiocarcinoma) were analyzed on a 73-gene, next-generation sequencing panel. Selected patients(pts) had longitudinal samples. Results: At least one alteration was detected in 46 cfDNA samples, in 16 (94%) of 17 pts – a pt with GBM had no alterations detected. 14 pts had alterations in FGFR2/3 by genomic testing of archival tumor samples, comprising 20 total alterations (18 unique). 10 of 20 FGFR2/3 alterations were also detected by cfDNA testing: 4/5 SNVs, 1/2 amplifications, 5/13 fusions. Three pts had FGFR/FGF alterations not included (thus not detected) in the cfDNA panel: 2 with FGF ligand amplification, and one FGFR4 mutation. 6 pts (35%) had PR, 5 (29%) had SD and 6 (35%) PD as a best response to TAS-120. Four pts had prior FGFRi: 2 had a PR, 1 SD, and 1 PD on TAS-120. Baseline cfDNA mutations became undetectable during treatment in 4/6 pts with PR. 4 of 6 PD pts had other driver mutations at baseline including mutations in PIK3CA, KRAS, IDH1, BRCA2, or amplifications in PIK3CA, PDGFR. 9 pts with cfDNA available at progression after SD/PR: 3 had acquired FGFR2 mutations (one each of V564L, V564F, or N549K). Two also acquired alterations in other candidate resistance genes ( PTEN and MAP2K1). Another pt had low variant allele frequency (VAF) NRAS G12D and BRAF A694T pretreatment and had SD. At progression, cfDNA revealed an increase in NRAS VAF and mutations acquired in the MAPK pathway . One pt with prior FGFRi acquired FGFR2 V564I and V564K detected by cfDNA prior to initiation of TAS-120, and had a PR on TAS-120. There was a drop in FGFR2 V564I VAF with response that subsequently increased with progression. The patient also acquired a FGFR2 V564L mutation at progression. Conclusions: FGFR alterations can be detected by cfDNA. cfDNA may detect potential resistance mechanisms, including PI3K or MAPK pathway alterations and acquired FGFR2 mutations. Patients with gatekeeper mutations in cfDNA at baseline may still respond to TAS-120. Further study is needed to determine the impact of FGFR2 mutations and co-alterations on TAS-120 sensitivity.
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Bemani, Mohammad, and Saeid Nikmehr. "Dual-band 3-way power divider and combiner based on CRLH-TLs." International Journal of Microwave and Wireless Technologies 8, no. 7 (June 11, 2015): 1037–43. http://dx.doi.org/10.1017/s1759078715000884.
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In this paper, by using composite right and left handed transmission lines and non-radiating CRLH-TLs, a dual-band 3-way series power divider (SPD) is presented. The proposed dual-band divider is designed and fabricated on an inexpensive FR4 substrate of thickness h = 0.79 mm and a relative dielectric constant of εr = 4.4 to work at 0.915 and 2.440 GHz. Also, in order to improve the isolation characteristics of this divider, three isolation resistors are implemented among output ports. Derived formulas are presented in details. The dual-band nature of the designed SPD, good input return loss, as well as equal power split among the three output ports, flexibility of spacing the output ports arbitrarily apart, and easy integration with planar devices make the proposed divider well suited for feeding many dual-band microwave circuits, such as multipliers, mixers, and planar array antennas. In addition, due to its excellent return-loss at the output ports and its high isolation, the proposed divider in this paper can be used as a power combiner.
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Mastropasqua, Angela, James Dowsett, Marianne Dieterich, and Paul C. J. Taylor. "Right frontal eye field has perceptual and oculomotor functions during optokinetic stimulation and nystagmus." Journal of Neurophysiology 123, no. 2 (February 1, 2020): 571–86. http://dx.doi.org/10.1152/jn.00468.2019.
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The right frontal eye field (rFEF) is associated with visual perception and eye movements. rFEF is activated during optokinetic nystagmus (OKN), a reflex that moves the eye in response to visual motion (optokinetic stimulation, OKS). It remains unclear whether rFEF plays causal perceptual and/or oculomotor roles during OKS and OKN. To test this, participants viewed a leftward-moving visual scene of vertical bars and judged whether a flashed dot was moving. Single pulses of transcranial magnetic stimulation (TMS) were applied to rFEF on half of trials. In half of blocks, to explore oculomotor control, participants performed an OKN in response to the OKS. rFEF TMS, during OKN, made participants more accurate on trials when the dot was still, and it slowed eye movements. In separate blocks, participants fixated during OKS. This not only controlled for eye movements but also allowed the use of EEG to explore the FEF’s role in visual motion discrimination. In these blocks, by contrast, leftward dot motion discrimination was impaired, associated with a disruption of the frontal-posterior balance in alpha-band oscillations. None of these effects occurred in a control site (M1) experiment. These results demonstrate multiple related yet dissociable causal roles of the right FEF during optokinetic stimulation. NEW & NOTEWORTHY This study demonstrates causal roles of the right frontal eye field (FEF) in motion discrimination and eye movement control during visual scene motion: previous work had only examined other stimuli and eye movements such as saccades. Using combined transcranial magnetic stimulation and EEG and a novel optokinetic stimulation motion-discrimination task, we find evidence for multiple related yet dissociable causal roles within the FEF: perceptual processing during optokinetic stimulation, generation of the optokinetic nystagmus, and the maintenance of alpha oscillations.
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Neggers, S. F. W., W. Huijbers, C. M. Vrijlandt, B. N. S. Vlaskamp, D. J. L. G. Schutter, and J. L. Kenemans. "TMS Pulses on the Frontal Eye Fields Break Coupling Between Visuospatial Attention and Eye Movements." Journal of Neurophysiology 98, no. 5 (November 2007): 2765–78. http://dx.doi.org/10.1152/jn.00357.2007.
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While preparing a saccadic eye movement, visual processing of the saccade goal is prioritized. Here, we provide evidence that the frontal eye fields (FEFs) are responsible for this coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging (fMRI)–guided transcranial magnetic stimulation (TMS) was applied to the FEFs 30 ms before a discrimination target was presented at or next to the target of a saccade in preparation. Results showed that the well-known enhancement of discrimination performance on locations to which eye movements are being prepared was diminished by TMS contralateral to eye movement direction. Based on the present and other reports, we propose that saccade preparatory processes in the FEF affect selective visual processing within the visual cortex through feedback projections, in that way coupling saccade preparation and visuospatial attention.
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Song, Siyu, Hongfei Chen, Xiangqian Yu, Ao Chen, Weihong Shi, Hong Zou, and Yuguang Ye. "Variation of Permittivity and Dark Conductivity of Polyimide and FR4 With Electron Dose by Experiments." IEEE Transactions on Nuclear Science 68, no. 9 (September 2021): 2375–82. http://dx.doi.org/10.1109/tns.2021.3101320.
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Rawat, Pramod, Rakesh Kumar Bachheti, Navin Kumar, and Nishant Rai. "PHYTOCHEMICAL ANALYSIS AND EVALUATION OF IN VITRO IMMUNOMODULATORY ACTIVITY OF RHODODENDRON ARBOREUM LEAVES." Asian Journal of Pharmaceutical and Clinical Research 11, no. 8 (August 7, 2018): 123. http://dx.doi.org/10.22159/ajpcr.2018.v11i8.25372.
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Objectives: The objectives of this study are to analyze phytoconstituents in Rhododendron arboreum leaves (qualitatively and quantitatively) and to estimate the immunomodulatory effects of extracts using different in vitro methods for intracellular and phagocytic killing potency of neutrophils, which are subsequent, involved in the process of phagocytosis by neutrophils.Methods: R. arboreum leaves extracts were separately extracted in 100% methanol, 50% methanol, and aqueous by a hot percolation technique using Soxhlet apparatus and concentrated with a vacuum rotary evaporator apparatus. The percentage yield of the extracts wares calculated. The extract was used to analyze phytoconstituents qualitatively, and total phenolic and flavonoid content were estimated. In another study, already purified methanolic extract of R. arboreum leaves, namely cytoplasmic male sterility (CMS-3) (kaempferol), RAM fr2, and transcranial magnetic stimulation (TMS-10) (ursolic acid) was used to evaluate immunomodulatory activities by nitroblue tetrazolium test, phagocytosis of killed Candida albicans.Results: Phytochemical screening of the extracts showed the presence of major classes of phytochemicals, i.e., phytosterols, flavonoids, phenols, alkaloids, carbohydrate, glycoside, sterols and steroids, terpenoids, and tannin while saponin was absent in all extract. The percent yield of leaves extract was 12.97%. Total phenolic content (TPC) expressed as gallic acid equivalents (GAE) ranged 1327.5±0.009 (in 100% methanolic extract), 1309.5±0.011 (in 50% methanolic), and 1468.5±0.006 mg GAE g−1 dry weight (in aqueous extract). Total flavonoid content expressed as rutin equivalents (RE) ranged 219±0.025 (in 100% methanolic extract), 184±0.02 (in 50% methanolic), and 262±0.58 mg (in aqueous extract) mg RE g−1 dry weight. R. arboreum purified extract CMS-3 (kaempferol), RAM fr2, and TMS-10 (ursolic acid) stimulated the neutrophils to phagocytic activity to the extent of 67.67±2.08%, 40.3±1.5%, and 79.67±0.57%, respectively. The above-said extracts stimulated the phagocytosis of killed C. albicans. The mean particle numbers for CMS- 3, RAM fr2, and TMS-10 were found to be 6.7, 6.3, and 7, respectively, at concentration 1 mg/ml.Conclusion: The phytochemical screening of all the extracts showed the presence of various phytochemicals that are biologically important. The total phenolic and flavonoid content of the plant are comparable to other medicinal plants. Even though the enormous progress on the phytochemistry and pharmacology of R. arboreum have been made, there still require more conclusive studies on the safety, efficacy, and in vivo toxicity of extracts and pure compounds to gain a better understanding.
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Stephenson, L. A., and M. A. Kolka. "Acetylcholinesterase inhibitor, pyridostigmine bromide, reduces skin blood flow in humans." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 258, no. 4 (April 1, 1990): R951—R957. http://dx.doi.org/10.1152/ajpregu.1990.258.4.r951.
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Five subjects exercised on a cycle ergometer for 30 min at 55% peak oxygen consumption on two occasions in an environmental test chamber (ambient temperature = 29 degrees C; dew point temperature = 10 degrees C). Pyridostigmine bromide (PYR), an acetylcholinesterase (AChE) inhibitor, was ingested (30 mg) approximately 150 min before one experiment, and no drug was administered during the other experiment (control). Red blood cell AChE inhibition averaged 40 (+/- 7)% during PYR treatment. Esophageal temperature (Tes), an eight site-derived mean skin temperature, forearm blood flow (FBF; venous occlusion plethysmography), skin blood flow (SkBF; laser-Doppler velocimetry), and metabolic rate (indirect calorimetry) were measured. SkBF decreased 37% after PYR treatment compared with control (P less than or equal to 0.05). The Tes threshold for initiation of cutaneous vasodilation was 36.8 (+/- 0.3) degrees C for the control treatment and 37.0 (+/- 0.3) degrees C for the PYR treatment (P less than or equal to 0.01). FBF was not significantly different between treatments, whereas heart rate was reduced by 7 and 9 beats/min during rest and exercise, respectively (P less than or equal to 0.01). The increased threshold for initiation of cutaneous vasodilation with AChE inhibition by PYR is compatible with nonthermal modulation of the control of thermoregulation through increased acetylcholine (ACh) accumulation. This could potentiate preganglionic transmission to enhance adrenergic vasoconstrictor tone. One suggested mechanism possible at the neuroeffector junction of the sweat gland may be that accumulated ACh diffusion across the adventitia of adjacent arterioles to muscarinic receptors initiates contraction of the smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
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Miyagawa, Ken, Yoshi-ichiro Kamijo, Shigeki Ikegawa, Masaki Goto, and Hiroshi Nose. "Reduced hyperthermia-induced cutaneous vasodilation and enhanced exercise-induced plasma water loss at simulated high altitude (3,200 m) in humans." Journal of Applied Physiology 110, no. 1 (January 2011): 157–65. http://dx.doi.org/10.1152/japplphysiol.00950.2010.
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We examined whether less convective heat loss during exercise at high altitude than at sea level was partially caused by reduced cutaneous vasodilation due to enhanced plasma water loss into contracting muscles and whether it was caused by hypoxia rather than by hypobaria. Seven young men performed cycling exercise for 40 min at 50% peak aerobic power in normoxia at (710 mmHg) 610 m, determined before the experiments, in three trials: 1) normobaric normoxia at 610 m (CNT), 2) hypobaric hypoxia [low pressure and low oxygen (LPLO)] at 3,200 m (510 mmHg), 3) normobaric hypoxia [normal pressure and low oxygen (NPLO)] at 610 m, in an artificial climate chamber where atmospheric temperature and relative humidity were maintained at 30°C and 50%, respectively. Subjects in CNT and LPLO breathed room air, whereas those in NPLO breathed a mixed gas of 14% O2 balanced N2, equivalent to the gas composition in LPLO. We measured change in PV (ΔPV), oxygen consumption rate (V̇o2), mean arterial blood pressure (MBP), esophageal temperature (Tes), mean skin temperature (Tsk), forearm skin blood flow (FBF), and sweat rate (SR) during exercise. Although V̇o2, MBP, Tsk, and SR responses during exercise were similar between trials ( P > 0.05), the sensitivity of forearm vascular conductance (FBF/MBP) in response to increased Tes was lower in LPLO and NPLO than in CNT ( P < 0.05), whereas that of SR was not, resulting in a greater increase in Tes from minute 5 to 40 of exercise in LPLO and NPLO than in CNT ( P = 0.026 and P = 0.011, respectively). ΔPV during exercise was twofold greater in LPLO and NPLO than in CNT. These variables were not significantly different between LPLO and NPLO. Thus reduced convective heat loss during exercise at 3,200 m was partially caused by reduced cutaneous vasodilation due to enhanced PV loss. Moreover, this may be caused by hypoxia rather than by hypobaria.
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Sagawa, S., K. Shiraki, and N. Konda. "Cutaneous vascular responses to heat simulated at a high altitude of 5,600 m." Journal of Applied Physiology 60, no. 4 (April 1, 1986): 1150–54. http://dx.doi.org/10.1152/jappl.1986.60.4.1150.
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Six healthy young men were studied in a high-altitude chamber during a 60-min heat exposure at a simulated altitude of 5,600 m or 0.5 atmosphere absolute (ATA). The heat load was provided by increasing the chamber temperature to 38 degrees C at the rate of 1 degree C/min after a 60-min equilibrium period at thermoneutrality (28 degrees C). Our question was whether or not hypoxia causes differential changes in regional cutaneous circulation during heat exposure. Skin blood flow in the forearm (FBF) and the finger (FiBF), temperatures of the esophagus (Tes) and of the skin, and cardiac output (CO) were measured during the heat exposure at 0.5 ATA and at the sea level (1 ATA). During the equilibrium period, hypoxia increased the mean skin temperature and mean heat transfer coefficient, as well as FBF and forearm vascular conductance. The increased blood flow in the cutaneous circulation during the hypoxic exposure may reflect cutaneous vasodilation and vasoconstriction in other regions of the body, since there was no alteration in CO and total peripheral resistance. During heat exposure, Tes rose faster at high altitude than at sea level. However, at the end of the 60-min heat exposure, all thermal as well as circulatory parameters showed no difference between the two altitudes, except for the FiBF. An attenuated vasodilation in the fingers during heat exposure at high altitude suggests differential vascular controls and possible impairment of thermoregulation when additional stress, such as heat, is imposed. The data suggest that cutaneous blood flow during heat exposure is not uniform throughout the entire skin in a hypoxic environment.
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Yang, Qing, and Zoi Kapoula. "Distinct Control of Initiation and Metrics of Memory-Guided Saccades and Vergence by the FEF: A TMS Study." PLoS ONE 6, no. 5 (May 26, 2011): e20322. http://dx.doi.org/10.1371/journal.pone.0020322.
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Stephenson, L. A., and M. A. Kolka. "Menstrual cycle phase and time of day alter reference signal controlling arm blood flow and sweating." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 249, no. 2 (August 1, 1985): R186—R191. http://dx.doi.org/10.1152/ajpregu.1985.249.2.r186.
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The changes occurring in the esophageal temperature (Tes) thresholds for initiation of heat loss responses as affected by the circadian period and menstrual cycle were studied. Four women exercised at 60% peak Vo2 in 35 degrees C (ambient water vapor pressure 1.73 kPa) for 30 min at 0400 and 1600 during the follicular (F) and luteal (L) phase. Tes, arm sweating rate (msw), and forearm blood flow (FBF) were measured frequently. At rest, Tes averaged 0.3 degrees C higher during L than F at both 0400 and 1600 and approximately 0.4 degrees C higher at 1600 than at 0400 during both phases. During exercise transients, the slopes of the FBF:Tes and the msw:Tes relationships were not different among treatments. The thresholds for initiation of sweating and cutaneous vasodilation were higher at 1600 than 0400 during both phases. Thresholds during F at 0400 averaged 36.44 degrees C for msw and 36.80 degrees C for vasodilation. The thresholds during L at 1600 averaged 37.46 and 37.53 degrees C for sweating and vasodilation, respectively. Our data indicate that the thermoregulatory effector activity during exercise is a function of numerous inputs, and one of these may be hormonal or hormonal-like in action. Controlling time of day and menstrual cycle phase are as important as controlling for aerobic power, age, and fitness in studying female thermoregulatory responses during exercise.