Caffeine has no effect on submaximal running in hypoxia in low caffeine consuming males and females.

BACKGROUND: Exposure to hypoxia immediately challenges a variety of physiologic systems that limit exercise capacity. Under normoxia, caffeine (CAFF) increases ventilation and subsequent oxygenation of hemoglobin (SpO2) and skeletal muscle (SmO2). CAFF improves exercise performance at altitude. However, little attention has been given to submaximal exercise in hypoxia, particularly regarding low CAFF consumers and female participants. The aim of this study was to determine the effect of CAFF on pulmonary, metabolic, and perceptual variables in response to submaximal running in hypoxia in low CAFF consuming males and females. METHODS: In a double blinded, counterbalanced design, 14 (6 females) individuals (24.1±5.1 years; VO2max: 40.6±5.6 mL × kg-1 × min-1; 20.8±8.0% body fat), who habitually consumed ≤150 mg/day of CAFF performed treadmill running at workloads of 25%, 40%, 60%, and 75% of sea level VO2max in normobaric hypoxia (FIO2=0.15) on two separate occasions: 1) 60 minutes after 6 mg/kg of CAFF; or 2) placebo. RESULTS: CAFF had no effect on any variable measured. Specifically, VE (condition: P=0.12; interaction: P=0.19), VT (condition: P=0.16; interaction: P=0.57), and Ve:VO2 (condition: P=0.07; interaction: P=0.69) were similar between groups. Further, CAFF had no effect on relative VO2 (condition: P=0.84; interaction: P=0.95), HR (condition: P=0.28; interaction: P=0.35), SmO2 (condition: P=0.66; interaction: P=0.82), or SpO2 (condition: P=0.16; interaction: P=0.97). Finally, rating of perceived exertion (RPE; P=0.92) and acute mountain sickness scores (P=0.29) were similar across conditions. CONCLUSIONS: These data demonstrate that CAFF provides no physiologic advantage to submaximal exercise in acute, normobaric hypoxia with low CAFF consuming males and females.

Effect of Combined Grape Seed Extract and L-Citrulline Supplementation on Hemodynamic Responses to Exercise in Young Males.

Grape seed extract (GSE) or L-citrulline supplement has been known to increase nitric oxide (NO) bioavailability and enhance endothelial-mediated vasodilation. Accordingly, to examine the additive benefits of combination of the two supplementations on hemodynamic responses to dynamic exercise, young, healthy males were recruited for this study. Effects of 7 days of 1) GSE + L-citrulline, 2) GSE, 3) L-citrulline, and 4) placebo supplementation on systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), cardiac output, total vascular conductance (TVC), and oxygen (O2) consumption were examined at rest and during cycling exercise. Compared with placebo, GSE, L-citrulline, and combined supplementations did not reduce SBP, DBP, and MAP, while cardiac output (placebo; 23.6 ± 1.3 L/min, GSE; 25.7 ± 1.1 L/min; L-citrulline, 25.2 ± 1.2 L/min; GSE + L-citrulline; 25.3 ± 0.9 L/min) and TVC (placebo; 234.7 ± 11.3 ml/min/mmHg, GSE; 258.3 ± 10.6 ml/min/mmHg; L-citrulline, 255.2 ± 10.6 ml/min/mmHg; GSE + L-citrulline; 260.4 ± 8.9 ml/min/mmHg) were increased at only the 80% workload (p < 0.05). Compared with placebo and L-citrulline, GSE and combined supplementations had a reduction in VO2 across workloads (p < 0.05). However, there was no additive benefits on these variables. We conclude that supplementation with GSE, L-citrulline, and combined supplementations increased cardiac output due partially to decreased vascular resistance. Our findings suggest that GSE may act as an ergogenic aid that can improve O2 delivery to exercising muscles.

Arterial Baroreflex Inhibits Muscle Metaboreflex Induced Increases in Effective Arterial Elastance: Implications for Ventricular-Vascular Coupling.

The ventricular-vascular relationship assesses the efficacy of energy transferred from the left ventricle to the systemic circulation and is quantified as the ratio of effective arterial elastance to maximal left ventricular elastance. This relationship is maintained during exercise via reflex increases in cardiovascular performance raising both arterial and ventricular elastance in parallel. These changes are, in part, due to reflexes engendered by activation of metabosensitive skeletal muscle afferents-termed the muscle metaboreflex. However, in heart failure, ventricular-vascular uncoupling is apparent and muscle metaboreflex activation worsens this relationship through enhanced systemic vasoconstriction markedly increasing effective arterial elastance which is unaccompanied by substantial increases in ventricular function. This enhanced arterial vasoconstriction is, in part, due to significant reductions in cardiac performance induced by heart failure causing over-stimulation of the metaboreflex due to under perfusion of active skeletal muscle, but also as a result of reduced baroreflex buffering of the muscle metaboreflex-induced peripheral sympatho-activation. To what extent the arterial baroreflex modifies the metaboreflex-induced changes in effective arterial elastance is unknown. We investigated in chronically instrumented conscious canines if removal of baroreflex input via sino-aortic baroreceptor denervation (SAD) would significantly enhance effective arterial elastance in normal animals and whether this would be amplified after induction of heart failure. We observed that effective arterial elastance (Ea), was significantly increased during muscle metaboreflex activation after SAD (0.4 ± 0.1 mmHg/mL to 1.4 ± 0.3 mmHg/mL). In heart failure, metaboreflex activation caused exaggerated increases in Ea and in this setting, SAD significantly increased the rise in Ea elicited by muscle metaboreflex activation (1.3 ± 0.3 mmHg/mL to 2.3 ± 0.3 mmHg/mL). Thus, we conclude that the arterial baroreflex does buffer muscle metaboreflex induced increases in Ea and this buffering likely has effects on the ventricular-vascular coupling.

Effects of chronic dietary grape seed extract supplementation on aortic stiffness and hemodynamic responses in obese/overweight males during submaximal exercise.

We investigated the effect of chronic grape seed extract (GSE) on blood pressure and aortic stiffness (AoS) among overweight and obese males. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (Q), total vascular conductance (TVC), and AoS were measured during two submaximal cycling exercises (40% and 60% VO2max), after 7 consecutive days of GSE or placebo (PL) ingestion with one week washout period. Compared with PL, GSE supplementation significantly decreased MAP at rest (85 ± 3 mmHg vs. 82 ± 3 mmHg), 40% (102 ± 3 mmHg vs. 99 ± 3 mmHg), and 60% workloads (109 ± 3 mmHg vs. 107 ± 3 mmHg) (P = 0.001, ES = 0.2). AoS was significantly reduced (13.0 ± 1.9 AU vs. 10.2 ± 1.0 AU) at rest (P = 0.002, ES = 0.6). Q was decreased at rest and across all workloads, but there were no significant differences (7.5 ± 0.4 L/min vs. 7.1 ± 0.4 L/min; 20.4 ± 1.2 L/min vs. 19.6 ± 0.9 L/min; 26.3 ± 1.1 L/min vs. 25.5 ± 1.6 L/min, respectively). GSE had no effect on HR, TVC, and SV. Our study indicates that chronic supplementation with GSE reduces arterial pressure at rest and during exercise primarily via the substantial reduction in AoS. Thus, GSE can be a dietary supplement to treat augmented blood pressure responses in obese and overweight males at rest and during exercise.Trial registration: ClinicalTrials.gov identifier: NCT04465110.

[Development of a Positive Nursing Organizational Culture Measurement Tool].

PURPOSE: The purpose of this study was to develop a measurement tool for a positive nursing organizational culture and to verify its reliability and validity. METHODS: A conceptual framework and construct factors were extracted through an extensive literature review and indepth interviews with nurses. The final version of the preliminary tool for the main survey was confirmed by experts through a content validity test and a preliminary survey of 40 nurses. Subsequently, the final tool was developed using a validity and reliability test containing 43 preliminary items. The final version of the tool was used with 327 hospital nurses in the testing phase for the main survey to assess validity and reliability. RESULTS: From the factor analysis, 4 factors and 26 items were selected. The factors were positive leadership of the nursing unit manager, pursuit of common values, formation of organizational relationships based on trust, and a fair management system. The entire determination coefficient was 67.7%. These factors were verified through convergent, discriminant, and concurrent validity testing. The internal consistency reliability was acceptable (Cronbach's α = .95). CONCLUSION: Both the validity and reliability of the scale were confirmed demonstrating its utility for measuring positive nursing organizational culture. It is expected to be used for education, research, and practical performance policies regarding the nursing organizational culture.

Key outcome summaries of the scientific programme of the IRPA15 congress.

This special issue of JRP includes a selection of research papers and review articles presented at the 15th Congress of the International Radiation Protection Association (IRPA15) as chosen by the scientific committee. All invited journal contributions are suitably expanded beyond the initial conference presentations to meet the criteria for a full journal article and include (a) presentation within a comprehensive radiological protection context and (b) additional data/interpretation. Published contributions address a wide spectrum of scientific topics and concepts to further develop the radiation protection (RP) system. They are based on scientific evidence and available experience in a wide spectrum of applications of the protection system. The IRPA is the international voice of the RP profession. It promotes excellence in RP by providing benchmarks of good practice, enhancing professional competence, and encourages the application of the highest standards of professional conduct, skills and knowledge for the benefit of individuals and society. Within the overarching theme of the conference 'Bridging RP Culture and Science-Widening Public Empathy' IRPA15 provided an invaluable opportunity to discuss and strengthen the relations between RP culture and science, and share developing scientific knowledge and related experience in RP among members of the scientific community, between representatives of key international organizations, including ICRP, IAEA, WHO, and NEA but also with the public. Some discussions focused on the rationale of available RP programmes and priorities, with an opportunity to identify and further develop key scientific issues of the current RP system as well as key processes for the interaction between members of the scientific community and society. The scientific programme of IRPA15 included eight topics and four thematic areas. The topical areas were: Underpinning Science; Dosimetry and Measurement; the System of Protection; Standards and Regulation; Practical Implementation-Medical Sector, as well as Industry and Research; Emergency Preparedness and Response; Existing Exposures and Non-ionizing Radiation. The thematic areas addressed were: Ethics; Communication and Public Understanding; RP Culture; Human Capital and Competency.

Effects of Acute Grape Seed Extract Supplementation on Hemodynamics in Normal Body Weight and Obese Males.

Recently, it has been reported that dietary supplementation with grape seed extract (GSE) ameliorates endothelial function and increase nitric oxide (NO) bioavailability. Thus, we investigated if elevated blood pressure and aortic stiffness (AoS) characterized in obese individuals are attenuated following acute GSE supplementation. Twenty men (obese=10; normal body weight (NBW)=10) participated in this study. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR), and AoS were compared 2 h after ingestion of GSE or placebo (PL) on different days, 1 wk apart. Compared with the PL, GSE supplementation significantly decreased SBP (NBW: 103±4 vs. 99±3 mmHg; obese: 118±3 vs. 112±5 mmHg) and MAP (NBW: 75±2 vs. 72±2 mmHg; obese: 86±3 vs. 84±3 mmHg) in both groups, while there were no differences in HR, SV, DBP, TPR, and AoS. GSE supplementation significantly decreased CO in only obese group. In NBW group, TPR tended to be decreased, but there was no significant difference. Our study suggests that acute supplementation with GSE reduced both SBP and MAP via a reduction in CO in obese individuals and decreased peripheral vasoconstriction in NBW group.

Augmented Hemodynamic Responses in Obese Young Men during Dynamic Exercise: Role of the Muscle Metaboreflex.

Studies found that cardiovascular responses to exercise are enhanced in individuals with obesity and are associated with a greater cardiac output (CO) response compared to normal weight controls. However, the mechanisms underlying these altered responses during dynamic exercise are not clear. We investigated whether the cardiovascular responses mediated by the muscle metaboreflex (MMR) activation are augmented in obese men during both static and dynamic exercise. Twenty males (10 obese (OG) and 10 non-obese (NOG)) were studied. Changes in CO, mean arterial pressure (MAP), and total vascular conductance (TVC) were compared between the two groups during dynamic handgrip exercise (DHE), post-exercise muscular ischemia (PEMI), and dynamic exercise corresponding to 40%, 60% and 80% workloads. Subjects completed 2 min of DHE at 30% of MVC, followed by 2 min of PEMI. MAP, CO, and TVC responses to DHE and dynamic exercise were significantly higher in OG, whereas there were no differences during PEMI. Increases in CO and MAP during mild to heavy dynamic exercise were seen in both groups, but the changes in these variables were greater in the OG. There were no significant differences in TVC between the two groups. Compared to NOG, the augmented blood pressure response to DHE and dynamic exercise in OG was associated with a greater increase in CO. Thus, the augmented CO and MAP responses were not associated with the activation of the MMR. Consequently, additional factors specific to obesity, such as the mechanoreflex, may have been involved.

Physiological and Biomechanical Differences Between Seated and Standing Uphill Cycling.

Despite differences in economy, cyclists climb in seated and standing positions. Prompted by gaps in research, we compared VO2 and heart rate (HR) (Study 1), muscle activation (Study 2) and breathing and pedaling entrainment (Study 3). METHODS: Subjects rode their bicycles on a treadmill in seated and standing positions. In Study 1, VO2 and HR of four male cyclists (21.3 ± 1.7 yrs; 69.1 ± 6 ml/kg/min) were collected, alternating positions every 5 minutes for 20 minutes (8 mph, 8% grade). In Study 2, muscle activations of eight male cyclists (24 ± 5 yrs, 67.6 ± 5.5 ml/kg/min) were collected on Rectus Femoris (RF), Biceps Femoris, Vastus Medialis (VM) and Gastrocnemius alternating positions every minute (8 mph, 8% grade). In Study 3, flow rate and entrainment of nine male cyclists (28 ± 7 yrs, 62.7 ± 7.7 ml/kg/min) were collected in 2-minute stages at 6, 8 and 10 mph, (8% grade) alternating positions every minute. RESULTS: VO2 and HR increased standing (3.17± 0.43 L/min, 175 ± 4 bpm) compared to seated (3.06 ± 0.37 L/min, 166 ± 5 bpm) (p < 0.05). Normalized EMG for RF and VM increased standing (47 ± 5%, 57 ± 15%) compared to seated (34 ± 3%, 36 ± 8%) (p < 0.05). Peak Inspiratory and Expiratory Flow increased standing (3.44±0.07 and 2.45±0.05 L/sec) compared to seated (3.09 ±0.06 and 2.21±0.04 L/sec) (p < 0.05). CONCLUSION: Uphill cycling while standing results in decreased cycling economy due to physiological and biomechanical variations compared to riding seated.

[Effect of Emotional Coaching Program for Clinical Nurses on Resilience, Emotional Labor, and Self-efficacy].

PURPOSE: This study aimed to assess the effect of the emotional coaching program for hospital nurses. METHODS: The study used a non-equivalent control group pretest-posttest design, and participants included 60 nurses (30 in the experimental group and 30 in the control group) who worked at a general hospital. The experimental group attended four sessions, one per week, with each session lasting two and a half hours. Collected data were analyzed using descriptive statistics, Fisher's exact test, χ² test, t-test, paired t-test, and repeated measures ANOVA using SPSS WIN 23.0 program. RESULTS: Significant differences were shown between the experimental and the control groups regarding emotional labor (F=68.40, p<.001), resilience (F=48.77, p<.001), and self-efficacy (F=15.31, p<.001). CONCLUSION: The emotional coaching program for nurses is useful for enhancing nurses' emotional labor management, resilience, and self-efficacy. In addition, this program may serve as a basis for providing emotional coaching to nurses in the future.

Effects of combined histamine H1 and H2 receptor blockade on hemodynamic responses to dynamic exercise in males with high-normal blood pressure.

While postexercise hypotension is associated with histamine H1 and H2 receptor-mediated postexercise vasodilation, effects of histaminergic vasodilation on blood pressure (BP) in response to dynamic exercise are not known. Thus, in 20 recreationally active male participants (10 normotensive and 10 with high-normal BP) we examined the effects of histamine H1 and H2 receptor blockade on cardiac output (CO), mean atrial pressure (MAP), aortic stiffness (AoStiff), and total vascular conductance (TVC) at rest and during progressive cycling exercise. Compared with the normotensive group, MAP, CO, and AoStiff were higher in the high-normal group before and after the blockade at rest, while TVC was similar. At the 40% workload, the blockade significantly increased MAP in both groups, while no difference was found in the TVC. CO was higher in the high-normal group than the normotensive group in both conditions. At the 60% workload, the blockade substantially increased MAP and decreased TVC in the normotensive group, while there were no changes in the high-normal group. A similar CO response pattern was observed at the 60% workload. These findings suggest that the mechanism eliciting an exaggerated BP response to exercise in the high-normal group may be partially due to the inability of histamine receptors. Novelty Males with high-normal BP had an exaggerated BP response to exercise. The overactive BP response is known due to an increase in peripheral vasoconstriction. Increase in peripheral vasoconstriction is partially due to inability of histamine receptors.

[Validity and Reliability of the Clinical Teaching Behavior Inventory (CTBI) for Nurse Preceptors in Korea].

PURPOSE: The aim of this study was to evaluate the validity and reliability of the Korean version of the Clinical Teaching Behavior Inventory (CTBI). METHODS: The English CTBI-23 was translated into Korean with forward and backward translation. Survey data were collected from 280 nurses' preceptors at five acute-care hospitals in Korea. Content validity, construct validity, and criterion-related validity were evaluated. Cronbach's α was used to assess reliability. SPSS 24.0 and AMOS 22.0 software was used for data analysis. RESULTS: The CTBI Korean version consists of 22 items in six domains, including being committed to teaching, building a learning atmosphere, using appropriate teaching strategies, guiding inter-professional communication, providing feedback and evaluation, and showing concern and support. One of the items in the CTBI was excluded with a standardized factor loading of less than .05. The confirmatory factor analysis supported good fit and reliable scores for the Korean version of the CTBI model. A six-factor structure was validated (χ²=366.30, p<.001, CMIN/df=2.0, RMSEA=.06, RMR=.03, SRMR=.05, GFI=.90, IFI=.94, TLI=.92, CFI=.94). The criterion validity of the core competency evaluation tool for preceptors was .77 (p<.001). The Cronbach's α for the overall scale was .93, and the six subscales ranged from .72 to .85. CONCLUSION: The Korean version CTBI-22 is a valid and reliable instrument for identifying the clinical teaching behaviors of preceptors in Korea. The CTBI-22 also could be used as a guide for the effective teaching behavior of preceptors, which can help new nurses adapt to the practicalities of nursing.

Grape Seed Extract Supplementation Attenuates the Blood Pressure Response to Exercise in Prehypertensive Men.

We tested the hypothesis that exaggerated pressor responses observed in prehypertensive males (N = 9) during dynamic exercise are attenuated following acute dietary supplementation with grape seed extract (GSE) (i.e., a single dose). Effects of placebo and GSE (300 mg) on systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP), cardiac output (CO), stroke volume (SV), total vascular conductance (TVC), and rate × pressure product (RPP) in response to two submaximal cycling workloads (40% and 60% VO2peak) were compared 2 h after ingestion of GSE or placebo on different days, 1 week apart. Endothelial function was also evaluated using flow-mediated dilation (FMD). Placebo treatment had no effect on any of the variables. GSE supplementation attenuated MAP at both workloads (40% VO2peak: 115 ± 1 vs. 112 ± 2 mmHg; 60% VO2peak: 126 ± 2 vs. 123 ± 2 mmHg) and RPP at the lower workload. Conversely, SV, CO, and TVC were augmented during both workloads. FMD was augmented by GSE (18.9 ± 2.0 vs. 12.4% ± 2.0%). These findings indicate that in exercising prehypertensive males, a single dose of GSE reduces blood pressure, peripheral vasoconstriction, and work of the heart and enhances O2 delivery; effects that may be due, in part, to endothelium-dependent vasodilation. We propose that acute GSE treatment represents an intervention that may minimize potential increases in the risk of cardiovascular events during dynamic exercise in prehypertensives.

Bovine colostrum supplementation does not affect plasma I-FABP concentrations following exercise in a hot and humid environment.

PURPOSE: To quantify the impact of a 14-day bovine colostrum (BC) supplementation on intestinal cell damage following exercise in a hot and humid environment. METHODS: Ten male participants (20 ± 2 years, VO2max 55.80 ± 3.79 mL kg-1 min-1, 11.81 ± 2.71% body fat) ran for 46 ± 7.75 min at 95% of ventiliatory threshold in 40 °C and 50% RH following a 14-day double-blinded supplementation with either BC or placebo (Plac). Core temperature, skin temperature, heart rate, and rating of perceived exertion were recorded every 5 min during exercise. Blood was taken pre, post, 1 h, and 4 h post exercise. Intestinal cell damage was assessed via intestinal fatty acid binding protein (I-FABP). RESULTS: I-FABP concentrations were similar between conditions at all time points [pre 989.39 ± 490.88 pg ml-1 (BC) 851.35 ± 450.71 pg ml-1 (Plac) post 1505.10 ± 788.63 pg ml-1 (BC) 1267.12 ± 521.51 pg ml-1 (Plac) 1-h, 1087.77 ± 397.06 pg ml-1 (BC) 997.25 ± 524.74 pg ml-1 (Plac) 4-h, 511.35 ± 243.10 pg ml-1 (BC) 501.46 ± 222.54 pg ml-1 (Plac)]. I-FABP was elevated pre to post exercise for both BC (162 ± 50%) and Plac (162 ± 56%) (p < 0.05). BC had no effect on mean body temperature [beginning 36.11 ± 0.30 °C, ending: 39.52 ± 0.28 °C (BC); beginning:35.96 ± 0.43 °C, ending:39.42 ± 0.38 °C (Plac)]. CONCLUSIONS: While BC supplementation may protect against enterocyte damage during exercise in thermonuetral environments, our data suggest that BC supplementation may not be an effective technique for preventing enterocyte damage during exercise when core temperature exceeds 39 °C.

Estimation of counting efficiencies of a portable NaI detector using Monte Carlo simulation for thyroid measurement following nuclear accidents.

Radioiodine can be released in nuclear accidents and can cause internal contamination of the thyroid gland in members of the public. For population monitoring in radiation emergencies, measurement of counting efficiency is very important to accurately determine thyroid activity. Here, we estimate the counting efficiencies of a portable NaI detector using Monte Carlo simulations. Two different types of neck phantoms and a 7.62 cm long by 7.62 cm diameter NaI detector were modeled and the counting efficiencies were calculated depending on the thyroid size and distance from the neck phantom to the detector. We found that distance is a more important parameter than thyroid size. The optimal distance of the NaI detector from the neck surface was determined to be greater than 12 cm, beyond which the counting efficiency was not affected by thyroid size.

[A Study on the Classification of Nursing Management Competencies and Development of related Behavioral Indicators in Hospitals].

PURPOSE: The aim of this study was to classify nursing management competencies and develop behavioral indicators for nurse managers in hospitals. Also, levels of importance and performance based on developed criteria were to be identified and compared. METHODS: Using expert survey we classified nursing management competencies and behavioral indicators with data from 34 nurse managers and professors. Subsequently, data from a survey of 216 nurse managers in 7 cities was used to analyze the importance-performance comparison of the classified nursing management competencies and behavioral indicators. RESULTS: Forty-two nursing management competencies were identified together with 181 behavioral indicators. The mean score for importance of nursing management competency was higher than the mean score for performance. According to the importance-performance analysis, 5 of the 42 nursing management competencies require further development: vision-building, analysis, change management, human resource development, and self-management competency. CONCLUSION: The classification of nursing management competencies and behavioral indicators for nurse managers in hospitals provides basic data for the development and evaluation of programs designed to increase the competency of nurse managers in hospitals.

[Experience of Role Adaptation from Nurse to Member of the Nursing Faculty].

PURPOSE: The purpose of this qualitative study was to evaluate the experience of role adaptation from nurse to member of the nursing faculty. METHODS: Data were collected from 13 members of a nursing faculty through in-depth interviews. The main question asked was "Could you describe your experience from being a nurse to becoming a member of the nursing faculty?" Qualitative data from the field and transcribed notes were analyzed using Strauss and Corbin's grounded theory methodology. RESULTS: The core experiential category of role adaptation from nurse to member of the nursing faculty was 'striving for survival from culture shock'. The participants used the following three interactional strategies: 'recognizing everything and entering the school environment', 'self-reflection on being a professor and integration of experiences', and 'finding a way of adapting'. CONCLUSION: The participants tried to adapt to life as a professor and reflected on and integrated their experiences into their new life on the faculty. College faculty need to understand the impact of changes and challenges faced by new professors during role adaptation and to support this adaptation through mentorship and organized orientation programs.

Histamine H2 receptor blockade augments blood pressure responses to acute submaximal exercise in males.

Histamine is a potent vasodilator that has been found to increase during exercise. We tested the hypothesis that histamine would attenuate blood pressure (BP), cardiac output (CO), and vascular resistance responses to short-term, submaximal dynamic exercise during H2 receptor blockade. Fourteen healthy men (20-29 years of age) were studied. Systolic (SBP), diastolic (DBP), and mean arterial (MAP) BP and heart rate (HR) were assessed at rest and during the last minute of 10 min of submaximal cycling exercise (60% of peak oxygen consumption) in the absence and presence of histamine H2 receptor blockade (ranitidine, 300 mg). Stroke volume (SV) (impedance cardiography) and plasma norepinephrine (NE) were measured, and CO, rate × pressure product (RPP), and total peripheral resistance (TPR) were calculated. Plasma levels of histamine were also measured. H2 blockade had no effects on any variables at rest. During exercise, SBP (184 ± 3 mm Hg vs. 166 ± 2 mm Hg), MAP (121 ± 2 mm Hg vs. 112 ± 5 mm Hg), and RPP (25.9 ± 0.8 × 10(3) mm Hg·beats/min vs. 23.5 ± 0.8 × 10(3) mm Hg/beats·min) were greater during blocked conditions (P < 0.05), and an interaction was observed for TPR. SV, DBP, HR, and NE levels were unaffected by blockade. Plasma histamine increased from 1.83 ± 0.14 ng/mL at rest to 2.33 ± 0.23 ng/mL during exercise (P < 0.05) and was not affected by H2 blockade (1.56 ± 0.23 ng/mL vs. 1.70 ± 0.24 ng/mL). These findings suggest that, during submaximal exercise, histamine attenuates BP, vascular resistance, and the work of the heart via activation of H2 receptors and that these effects occurred primarily in the vasculature and not in the myocardium.

The role of metaboreceptor on exercise in hyperthermic environment with college basketball players.

The objective of this study is to review physiological differences of college basketball players cardiovascular responses and group IV metaboreceptor interactions appearing post muscular ischemia exercise (PEMI) caused by a static handgrip exercise (SHE). The subjects were placed in a temperature and moisture stabilized indoor environment for 2 h in order to measure blood pressure. For the SHE, maximal voluntary contraction of arms with a relative strength of 50 % of the maximum muscular strength was put into isometric training for 2 min. After completing the exercises, cuffs worn on the arms of the subjects were pressurized up to 200 mmHg by applying PEMI to block the artery and vein. In this way, the cardiovascular responses created by SHE and PEMI were measured. Blood samples of subjects were collected from the vein of each upper arm before SHE and after PEMI to measure the metabolite hormone and catecholamine in the blood. Results from the measurements showed a significant decrease of blood pressure under high temperature environments compared to normal temperature environments. With respect to PEMI, increases in blood pressure under the high temperature environment were significantly lower compared to the normal temperature environment. In conclusion, this study revealed that college basketball players with good physical strength had higher sensitivities of arterial baroreceptor. However, blood pressure was not increased accordingly because the increase of cutaneous vasoconstriction due to stimuli of the metaboreceptor under a high temperature environment could not be compensated by arterial baroreflex due to the increase of total vascular conductance.

Effects of Kyunghee Facial Resistance Program (KFRP) on mechanical and elastic properties of skin.

INTRODUCTION: Facial skin aging is influenced by weakened mimetic muscles. Resistance training of facial mimetic muscles could be one of practical strategy to defend against age-related changes. The aim of this study was to investigate the effects of an exercise program (KFRP: Kyunghee Facial Resistance Program) designed for facial mimetic muscles on the mechanical properties and elasticity of facial skin. METHODS: For this study, 16 healthy female volunteers aged 35-58 participated in KFRP for eight weeks. The mechanical and elastic properties of skin were measured using a Cutometer® on the face and neck. RESULTS: The parameters representing skin fatigue decreased and the parameters representing skin elasticity increased significantly compared to the baseline in all measured regions. The ability of re-deformation of skin increased significantly except the zygomaticus and platysma muscle regions. All measured regions of skin became firmer and the ability to return to the initial position was also significantly improved compared to the baseline. Visco-elasticiy of the skin was not significantly altered. CONCLUSIONS: The skin became more firm and elastic through KFRP. This method of resistive exercise had a significantly positive influence on the mechanical properties and elasticity of facial and neck skin.