Short Rest Research Articles

Muscle Damage and Inflammatory Response from Volume-Equated Resistance Exercise with Short vs Long Rest Interval

Muscle Damage and Inflammatory Response from Volume-Equated Resistance Exercise with Short vs Long Rest Interval

Effect of Rest Duration Between Static Stretching on Passive Stiffness of Medial Gastrocnemius Muscle In Vivo.

In clinical and sports settings, static stretching (SS) is usually performed to increase range of motion (ROM) and decrease passive muscle stiffness. Recently, the shear elastic modulus was measured by ultrasonic shear wave elastography as an index of muscle stiffness. Previous studies reported that the shear elastic modulus measured by ultrasound shear wave elastography decreased after SS, and the effects of SS on shear elastic modulus were likely affected by rest duration between sets of SS. To investigate the acute effects of SS with different rest durations on ROM and shear elastic modulus of gastrocnemius and to clarify whether the rest duration between sets of SS decreases the shear elastic modulus. A randomized, repeated-measures experimental design. University laboratory. Sixteen healthy males volunteered to participate in the study (age 21.3 [0.8] y; height 171.8 [5.1]cm; weight 63.1 [4.5]kg). Each participant underwent 3 different rest interval durations during SS (ie,long rest duration: 90s; normal rest duration: 30s; and short rest duration: 10s). This SS technique was repeated 10 times, thus lasting a total of 300 seconds with different rest durations in each protocol. The dorsiflexion ROM and shear elastic modulus were measured before and after SS. Our results revealed that dorsiflexion ROM and shear elastic modulus were changed after 300-second SS; however, no effects of the rest duration between sets of SS were observed. In terms of decreasing the shear elastic modulus, clinicians and coaches should not focus on the rest duration when SS intervention is performed.

Desempenho de repetições e tempo sob tensão no método Cluster Sets vs. tradicional em uma sessão de treinamento de força

Introdução: O método cluster sets (CLS) surge como um método de treinamento de força (TF) incluindo pequenos intervalos dentro da série. Objetivo: comparar o desempenho agudo do método CLS e o método tradicional (TRAD). Métodos: participaram do estudo 14 homens com experiência em TF. Os participantes realizaram dois protocolos distintos: TRAD - três séries de oito repetições com 90% de 8 repetições máximas (RM) e intervalo de dois minutos; CLS - três séries com oito repetições com 90% de 8 RM, e 30 segundos de intervalo a cada duas repetições. Resultados: o método CLS foi capaz de manter o desempenho ao longo das séries, sem reduções significativas nas séries 2 e 3, em ambos exercícios. Ao compará-lo com o método TRAD, o número de repetições realizadas foi significativamente maior (p ≤ 0,05) para o CLS. Conclusão: o CLS proporcionou desempenho de repetições máximas superior em comparação ao TRAD. Não foram verificadas diferenças no tempo sob tensão entre os protocolos.

Short rest between shifts (quick returns) and night work is associated with work-related accidents.

The aim of this study was to examine whether less than 11h between shifts (i.e., quick returns, QRs) and night shifts is associated with self-reported work-related accidents, near accidents or dozing off at work in a sample of nurses. The study was based on cross-sectional data from 1784 nurses (response rate = 60%; mean age = 40.1years, SD = 8.4; 91% female). Negative binomial regression analyses were conducted to investigate the association between the shift exposures, and eight different self-reported work-related items on accidents, near accidents and dozing off at work, controlling for demographics and work factors. The number of QRs during a year was positively associated with seven of the eight items on work-related accidents, near-accidents and dozing off at work, and number of night shifts was positively associated with five items. Some of the key findings were that QRs were associated with nurses causing harm to themselves (incidence rate ratio [IRR] = 1.009; 95% CI = 1.005-1.013), causing harm to patients/others (IRR = 1.006; 95% CI = 1.002-1.010) and causing harm to equipment (IRR = 1.004; 95% CI = 1.001-1.007); while night shifts were associated with nurses involuntarily dozing off at work (IRR = 1.015; 95% CI = 1.013-1.018), dozing off while driving to/from work (IRR = 1.009; 95% CI = 1.006-1.011), and harming patients/others (IRR = 1.005; 95% CI = 1.001-1.009). QRs and night shifts were both associated with the self-reported work-related accidents, near-accidents and dozing off at work. Studies that can establish the causal relationship between QRs and accidents are called for.

Suitability of jumps as a form of high-intensity interval training: effect of rest duration on oxygen uptake, heart rate and blood lactate

High-intensity interval training (HIT) has been shown to be an effective endurance training method. However, most HIT research has been conducted on running and cycling. The aim of this study was to assess the suitability of intermittent exercises such as jumps as a type of HIT. Respiratory gases, heart rate and ground reaction forces were recorded for 21 participants (age 25 ± 4years, mass 73 ± 12kg, 13 male) during 5 distinct jump sessions on different days that varied with respect to the rest durations in between series (0, 15 or 30s) and in between jumps (0, 1 or 2s). Blood lactate was determined 3min after the last series. Prior to the first session, maximal jump height as well as V'O2max during cycling was recorded. Peak oxygen uptake and heart rate were nearly maximal during all five jump sessions (87-99% of V'O2max, 96-98% of maximal heart rate). The time spent at more than 90% of V'O2max (1-43% of the total session duration), average jump height (34-82% of maximal jump height) and lactate accumulation (4-9mmol/l) differed between jump sessions, mainly depending on the rest interval between jumps (p < 0.001, rmANOVA between sessions with different rest intervals between jumps). With short rest intervals, jumping elicited comparable acute responses as reported for running or cycling HIT. Thus, training programs using intermittent exercises should elicit similar adaptations as other forms of HIT, provided the rest intervals are sufficiently short. Heart rate might be of limited value when comparing different types of HIT.

Effect of caffeinated gum on a battery of rugby-specific tests in trained university-standard male rugby union players

BackgroundCaffeine has been shown to enhance strength, power and endurance, characteristics that underpin performance in rugby. Caffeinated gum has attracted interest as a novel vehicle for delivering caffeine, because absorption of caffeine from gum is quick. Rapid absorption of caffeine may be useful during rugby matches when there is limited time for supplementation such as at half-time or when substitutes enter play. The purpose of this study was to determine whether a low dose of caffeine in gum improves performance in a battery of rugby-specific tests.MethodsIn a double-blind, randomized, placebo-controlled, crossover design, 17 male university-standard rugby players (mass: 85.6 ± 6.3 kg; height: 179.4 ± 6.2 cm; age: 20.4 ± 1.2 years) chewed caffeinated gum (200 mg caffeine) or a placebo gum on two occasions separated by a week. After a standardized warm-up, gum was chewed for 5 min. Subsequently, participants performed three countermovement jumps, followed by an Illinois agility test, 6 × 30 m repeated sprints, and the Yo-Yo IR-2 test; each test was separated by short rest periods.ResultsCaffeinated gum enhanced countermovement jump by 3.6% (caffeine: 43.7 ± 7.6 cm vs. placebo: 42.2 ± 6.2 cm; d = 0.22, 95% CI [0.006, 0.432]; p = 0.044). There was a greater resistance to fatigue during the 6 × 30 m repeated sprint test (fatigue index caffeine: 102.2 ± 0.9% vs. placebo: 103.3 ± 1.2%; d = 1.03, 95% CI [0.430, 1.613]; p = 0.001), and performance on the Yo-Yo IR2 was improved by 14.5% (caffeine: 426 ± 105 m, placebo: 372 ± 91 m; d = 0.55, 95% CI [0.130, 0.957]; p = 0.010). Caffeine gum had no significant effect on the Illinois agility test (caffeine 16.22 ± 1.08 s vs. placebo 15.88 ± 1.09 s; d = − 0.31, 95% CI [− 0.855, 0.240]; p = 0.271).ConclusionsIn university-standard rugby players, a low dose of caffeine (200 mg) supplied in chewing gum enhanced performance on the Yo-Yo IR-2 test and the countermovement jump test and reduced fatigue index during repeated sprints. These improvements in a battery of rugby-specific tests may transfer to enhanced performance in rugby matches.

The effects of change in the safety rope protocol, hold size, and rest period on psychophysiological responses in sport rock climbers

PurposeThe aim of the study was to evaluate the effects of a decrease in hold size, change in the safety rope protocol, and rest period shortening on heart rate (HR), heart rate variability (HRV), pre-climb anxiety, and perceived workload in sport rock climbers under laboratory settings.MethodsA total of 12 intermediate sport rock climbers were recruited. The participants completed 2 routes of different climbing difficulty. They repeated the difficult route with a short 5-minute rest period 3 times and repeated the same route with a change to lead climb. HR, HRV, anxiety level (Competitive State Anxiety Inventory-2 Revised), and climbing workload (NASA&lt;sub&gt;climbing&lt;/sub&gt; questionnaire) were measured.Results and conclusionsIt was lead climb that elicited the most noticeable psychophysical response in the intermediate climbers. Prior to the climb, the performers exhibited marked sympathetic activation and higher cognitive anxiety. Climbing HR&lt;sub&gt;peak&lt;/sub&gt; was correlated with physical workload, psychological demand, and increasing fatigue; hence, it can be considered a variable that reflects the accumulative psychophysiological stress. NASA&lt;sub&gt;climbing&lt;/sub&gt; score effectively reflected differences in physical load (physical demand – strength and endurance) and psychological load (higher mental demand, temporal demand, and satisfaction level) during climbing.

Subjective and objective evaluation of visual fatigue caused by continuous and discontinuous use of HMDs

AbstractDuring continuous use of displays, a short rest can relax users' eyes and relieve visual fatigue. As one of the most important devices of virtual reality, head‐mounted displays (HMDs) can create an immersive 3D virtual world. When users have a short rest during the using of HMDs, they will experience a transition from virtual world to real world. In order to investigate how this change affects users' eye condition, we designed a 2 × 2 experiment to explore the effects of short rest during continuous using of HMDs and compared the results with those of 2D displays. The Visual Fatigue Scale, critical flicker frequency, visual acuity, pupillary diameter, and accommodation response of 80 participants were measured to assess the subject's performance. The experimental results indicated that a short rest during the using of 2D displays could significantly reduce users' visual fatigue. However, the experimental results of using HMDs showed that short rest during continuous using of HMD induced more severe symptoms of subjectively visual discomfort, but reduced the objectively visual fatigue.

Acute physiological responses and performance following subsequent CrossFit ‘CINDY’ workout with Zea Mays juice

Purpose: The purpose of this study was to investigate the physiological responses and performance following subsequent repeated high intensity exercise with consumption of Zea may juice ( ZM ) Materials: Total of seventeen participants involved in the study. They were physically active who had cardio and strength training at least 3 times per week. The age of participants was 21.8±1.7 years old, body weight 65.4±11.2 kg and height 169.7±7.2 cm. Crossfit ‘CINDY’ exercise were repeated between two hours of rest. Treatment beverage of ( ZM ) juice vs Carbohydrate-electrolyte (CE) drinks were consumed immediately after exercise in double blind cross over manner. Number of complete set of exercise, heart rate, blood lactate and rate of perceived exhaustion (RPE) were recorded at the end of each exercise session. Results: Total number of complete ‘CINDY’ exercise significantly increased in ZM juice group during second bout of exercise compared to CE drink group. There were no significant difference in heart rate, blood lactate and RPE in both groups Conclusions: ZM juice has potentials an alternative recovery beverage to promote subsequent repeated exercise within short rest time.

Efectos del pastoreo holístico sobre la estructura y composición vegetal en praderas naturalizadas de uso ganadero, provincia de Última Esperanza, región de Magallanes, Chile

Naturalized grasslands in Magallanes are important but fragile agro-ecosystems that may change due to climatic variations and overgrazing. Holistic grazing (HG) has been introduced into Magallanes in 2013 as a new, management intensive technological alternative, that in principle would improve the health of grassland. Considering this, it is priority to generate scientific information and maintain a permanent follow-up on this type of management. The objective of this study was to analyze the effects on vegetation in order to assess whether holistic grazing degrades or improves the floristic structure and composition of naturalized grasslands. We compared three paddocks managed under grazing holistic (HG): La Campana, Lago Sofia and Parcela Tamara, with three equivalent areas under Semi-Intensive grazing (SIG), a traditional management in the area that includes rotations with short rests: Tres Pasos, Dos Lagos and Parcela Colonia Isabel Riquelme. All areas were ecologically equivalent and derived from substitution of nirre forests (Nothofagus antarctica (G. Forst.) Oerst.), and located in the province of Ultima Esperanza, with 389 mm annual rainfall. The study was conducted between 2014-18, with an average rainfall of 372 mm which is within normal for that area. The hypothesis was that the HG would increase the vegetation cover, palatable species cover and diversity. Vegetation and soil monitors were installed in three fields with HG and three SIG following the MARAS methodology. The results indicate that changes over the years were not significant in terms of cover (p>0.8450), but significant differences were observed in species richness (P 0.1710). In conclusion, plant cover increase was not detected for HG, but species dominance was rearranged, as palatable, exotic species, increased under HG. This is perhaps because grazing pressure decreased competition in the canopy, favoring naturalized exotic species such as white clover (Trifolium repens) that could not compete with invasive weeds like Achillea millefolium and Hieracium prealtum under SIG. Future trials should consider evaluating productive parameters such as forage availability, weight and animal health status.

Effect of transversus abdominis plane block on postoperative rehabilitation of colorectal cancer patients

Objective To evaluate the effect of transversus abdominis plane block(TAPB) on postoperative recovery of patients with colorectal cancer. Methods Sixty patients with colorectal cancer undergoing elective laparoscopic surgery were randomized into two groups (n=30): transversus abdominis plane block group (group TAPB) and control group (group C). Patients in group TAP and group C respectively received postoperative TAPB and patient-controlled intravenous analgesia(PCIA). The VAS scores, bed rest time, and the time of first exhaustion were recorded 4, 8, 12, 24 h after operation. The protein levels of plasma IL-6, TNF-α, and C-reactive protein(CRP) were determined before surgery, immediately after surgery, and 4, 12, 24 h after surgery. Results The VAS scores 4, 8, 12, 24 h after TAPB in group TAPB were significantly lower than those in group C(P<0.05). Patients in group TAPB had shorter bed rest time and earlier exhaustion than patients in group C(P<0.05). The protein levels of IL-6, TNF-α and CRP in group C did not differ immediately after surgery, but were significantly reduced 4, 12, 24 h after surgery, compared with those in group C (P<0.05). Conclusions TAPB can effectively relieve postoperative pain and reduce the production of inflammatory factors, therefore is beneficial for patients' postoperative rehabilitation. Key words: Transversus abdominis plane block; Colorectal cancer; Fast track

Electrochemical behaviour of copper in alkaline glycine solutions

The fundamental electrochemical properties of the copper-glycine system were investigated in this study to understand the factors that affect the dissolution of metallic copper. Potentiodynamic polarisation measurements were carried out over the pH range 9.0 to 11.5, at temperatures of 22 °C and 60 °C and glycine concentrations 0.1 M and 0.3 M. A window for maximum corrosion current was determined to be between pH 10.0 and 10.5 with a maximum at 60 °C and 0.3 M glycine. Passivation was only observed at pH values >10.5, and then only at potentials above 0.4 V (vs SHE) for quiescent solutions. This passivation potential increased with the rotation speed of the copper electrode. The passive layer broke down after a short rest at the open circuit potential, which allowed reactivation of the surface and high initial currents to briefly flow until the layer re-formed. Potential-step and capacitance measurements are consistent with the formation of a duplex oxide layer of Cu2O and CuO that thickens with increasing potential. The copper glycinate complex itself also acts as an oxidising agent, the effectiveness is increased with its concentration and the concentration of free glycine. Free glycine is oxidised irreversibly above 1.2 V (vs SHE).

Obóz powstańczy podczas insurekcji styczniowej 1863 roku

Specyfika wojny partyzanckiej i ciągłe przemieszczanie się partii powstańczych podczas insurekcji styczniowej 1863 r. nie sprzyjały zakładaniu stałych obozów wojskowych. Jedynie w pierwszych miesiącach powstania zakładano obozy, które w jakimś stopniu zgodne były z instrukcjami władz centralnych powstania. Takim przykładem był obóz oddziału dowodzonego przez Apolinarego Kurowskiego założony w Ojcowie. W późniejszym okresie, kiedy wojska rosyjskie zaczęły kontrolować niemal wszystkie regiony Królestwa Polskiego, obozy powstańcze przewidziane były z reguły na zaledwie kilkudniowy postój. Można konkludować, iż faktycznie w okresie powstania styczniowego dominowały tzw. obozy marszowe. Przedstawiały one wszelkie formy przejściowe między stałymi, wykorzystywanymi przez wiele dni obozami, a prostym zatrzymaniem się na sen i krótki wypoczynek w czasie marszu.

EVALUATION OF VERTICAL AND HORIZONTAL SACCADES USING THE DEVELOPMENTAL EYE MOVEMENT TEST COMPARED TO THE KING-DEVICK TEST

Oculomotor function is impaired when an individual has a concussion and as such, it is important to identify tests that are able to assess oculomotor impairment. The King-Devick (K-D) test assesses horizontal saccadic eye movement and attention. The Developmental Eye Movement (DEM) test is designed to identify oculomotor dysfunction in children. It measures both horizontal and vertical saccades. The K-D test shows promise as a concussion-screening tool and part of a multifactorial assessment. The DEM has not been tested as a concussion assessment tool, but the neuroanatomical control of horizontal and vertical saccades originates from different areas of the brain, so one might expect to see differences in performance on the K-D and DEM tests when administered to concussed patients. First, it is important to determine if performance on the DEM and K-D tests, particularly with respect to the measurement of vertical and horizontal saccades, is similar in a healthy population.Hypothesis/Purpose: The primary purpose was to evaluate the relationship between horizontal and vertical saccade tests over repeated trials in normal, healthy subjects. A secondary purpose of this study was to determine the number of trials needed to reach a performance plateau for both the DEM and K-D tests.Study Design: This study used a prospective cohort research design. Forty-two healthy non-concussed participants (22 males, 20 females; mean age, 24.2 ± 2.92 years) completed six repeated trials of both the DEM, and then six trials of the K-D test in a single testing session. Trials within each test were performed in random order and participants were offered short rest breaks as needed between test administrations. Results indicated strong correlations, r=.67, or greater, between measurements of horizontal and vertical saccades. Performance plateaued on the K-D at trial three and on the DEM at trial two for both horizontal and vertical saccades. It appears that the DEM and K-D tests measure similar constructs in healthy individuals and that no additional information is provided by assessment of vertical saccades. Additional studies are required to investigate the usefulness of the DEM in concussed individuals. 3: Laboratory study with repeated measures.

PEMBERIAN BUAH PISANG, ISTIRAHAT PENDEK DAN PEREGANGAN MENURUNKAN KELUHAN MUSKULOSKELETAL, KELELAHAN DAN MENINGKATKAN PRODUKTIVITAS PEMANEN PENGGUNA ALAT EGREK PERKEBUNAN KELAPA SAWIT PT. SSD KALIMANTAN TIMUR

In cutting of fresh palm coconut by using of egrek tools have repeatition movement and need extra of muscle strength. The worker have exhaution experience, so sometimes they took a rest in working time. Using of muscle continously and unergonomic position of worker could lead musculosceletal problems. In order to balance of enough nutrient and proper worker’s posture. The aim of this research to prove that consumption of banana, short rest and stretching in reducing of musculosceletal problems, exhaution and increasing of permanent palm coconut worker productivity in using of egrek tools.&#x0D; The research was done in form of PT. SSD Berau, with treatment by subject design toward 16 workers sample. Period I (P0) of harvest process without intervention and period II (P1) of harvest process with intervention. Exhaution was using 30 item of rating scale exhaution and productivity based on output and input comparison. Data tasted by t-paired test in testing of musculosceletal problem, exhaution and productivity difference in significant level ? = 0.05 before and after working. And t-independent test for difference between groups.&#x0D; The result of research with intervention of musculoskeletal problems of period I before work 37.44 ± 1,21 and after 69.25 ± 2.24, period II before work 37.75 ± 1,13 and after 47,25 ± 4,95 decrease of 31.77%; exhaution period I before working 39.31 ± 1.35 and after 72.63 ± 1.50, period II before work 36.69 ± 1.62 and after 55.38 ± 1.78 decrease of 23.75%, productivity period I 0.51 ± 0.08 and period II 0.70 ± 0.06 increase of 38.40%. There was decreasing in musculoskeletal problems, exhaution and increase productivity with signifikan level (p &lt;0.05).It can be concluded the giving of banana, short rest and stretching decrease musculoskeletal problems, exhaution and increase productivity of harvesters egrek tool user of palm oil plantation PT. SSD. It suggested to apply the interventions in oil palm plantations in reducing musculoskeletal problems, exhaution for increased productivity.

Análisis de la percepción subjetiva del esfuerzo diferenciado y de la fatiga en distintos formatos de juegos reducidos en fútbol

The aim of this study was to analyze the differentiated perceived exertion (dRPE) in different small sided games (JR) formats of 4 vs. 4 varying both the size of the soccer field and the duration of rests between repetitions. A loss of performance in sprint of 5 and 15 m and in the capacity of change of direction (CODA) with and without ball was also analyzed. 46 soccer players who competed in Division Honor, Tercera Regional and Segunda Regional participated in this study. A loss of performance in the sprint 5 m (p 0.05, TE = 0.8 high). Possibly a smaller sided games with short rest time can cause a greater loss of performance in the sprint of 5 m and in the test 505 without ball.

Upper and lower body responses to repeated cyclical sprints

Purpose: To compare the physiological and perceptual responses of the upper and lower body to all-out cyclical sprints with short or long rest periods between sprints.Methods: Ten recreationally trained males completed four 10 × 10 s sprint protocols in a randomized order: upper body with 30 s and 180 s of rest between sprints, and lower body with 30 s and 180 s of rest between sprints. Additionally, maximum voluntary contractions (MVC) were measured at pre-sprint and post-sprints 5 and 10. Normalized (% of first sprint) peak power, MVC, heart rate (HR) and rating of perceived exertion (RPE) were compared between upper and lower body within the same recovery period, and absolute values (Watts, bpm, RPE scores) were compared within the same body part and between recovery periods.Results: Trivial differences were identified in normalized peak power, HR and RPE values between the upper and lower body in both recovery conditions (<2%, d ≤ 0.1), but MVC forces were better maintained with the upper body (∼9.5%, d = 1.0) in both recovery conditions. Absolute peak power was lower (∼147 Watts, d = 1.3), and HR was higher (∼10 bpm, d = 0.73) in the 30 s compared to 180 s condition in both the upper and lower body whereas RPE scores were similar (<0.6 RPE units, d ≤ 0.1). Despite the reductions in peak power, MVC forces were better maintained in the 30 s condition in both upper (2.5 kg, d = 0.4) and lower (7.5 kg, d = 0.7) body.Conclusions: Completing a commonly used repeated sprint protocol with the upper and lower body results in comparable normalized physiological and perceptual responses.

Influence of very short rest period lengths on repeated one maximun repetition bench press performance

&#x0D; Objective: The purpose of this investigation was to compare different rest period lengths between consecutive one maximum repetition bench press attempts on performance and ratings of perceived exertion.&#x0D; &#x0D; &#x0D; &#x0D; Method: Eighteen trained men (27.95 ± 4.25 years; 81.00 ± 9.21 kg; 174.62 ± 3.34 cm; bench press relative strength 1.33 ± 0.11 kg/kg of body mass) participated in three randomly ordered sessions that required two consecutive one maximum repetition bench press attempts with 20, 40, or 60-s rest between attempts.&#x0D; Results: The Cochran Q analysis showed no significant differences in the ability to successfully perform a second one maximum repetition attempt with 20, 40, or 60-s rest between attempts (p = 0.882). Specifically, no significant differences were found in the successful completion of the first and second attempts for the 20-s (p = 0.317), 40-s (p = 0.083), and 60-s (p = 0.157) trials, respectively. Briefly, for both 20 and 60-s rest conditions Δ% = 88.88% of subjects successfully performed the second attempt and, for the 40-s protocol, only Δ% = 83.33% completed. For the pre and post-set ratings of perceived exertion, the shorter rest period (20-s) promoted significantly higher values compared to the longer rest periods (pre-set ratings of perceived exertion, p = 0.04; post-set ratings of perceived exertion, p = 0.023).&#x0D; Conclusions: The results of this study can be applied to recreationally trained individuals with the intent of generating a time-efficient process for conducting a valid and reliable one maximum repetition bench press assessment.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D;

Process-specific analysis in episodic memory retrieval using fast optical signals and hemodynamic signals in the right prefrontal cortex

Objective. Memory is formed by the interaction of various brain functions at the item and task level. Revealing individual and combined effects of item- and task-related processes on retrieving episodic memory is an unsolved problem because of limitations in existing neuroimaging techniques. To investigate these issues, we analyze fast and slow optical signals measured from a custom-built continuous wave functional near-infrared spectroscopy (CW-fNIRS) system. Approach. In our work, we visually encode the words to the subjects and let them recall the words after a short rest. The hemodynamic responses evoked by the episodic memory are compared with those evoked by the semantic memory in retrieval blocks. In the fast optical signal, we compare the effects of old and new items (previously seen and not seen) to investigate the item-related process in episodic memory. The Kalman filter is simultaneously applied to slow and fast optical signals in different time windows. Main results. A significant task-related HbR decrease was observed in the episodic memory retrieval blocks. Mean amplitude and peak latency of a fast optical signal are dependent upon item types and reaction time, respectively. Moreover, task-related hemodynamic and item-related fast optical responses are correlated in the right prefrontal cortex. Significance. We demonstrate that episodic memory is retrieved from the right frontal area by a functional connectivity between the maintained mental state through retrieval and item-related transient activity. To the best of our knowledge, this demonstration of functional NIRS research is the first to examine the relationship between item- and task-related memory processes in the prefrontal area using single modality.

The Mass Transfer and Coalescence Time Scales in Binary Droplet Systems for Copper Extraction

In this work, we studied whether coalescence has a direct effect on mass transfer in copper extraction. The coalescence of pendant and sessile droplets containing diluted Acorga M5640 in an aqueous copper sulfate solution was recorded on video. The videos were analyzed to determine droplet rest times, sizes, and concentrations. Concentration measurements revealed that coalescence does not enhance mass transfer because coalescence is a rapid phenomenon. A comparison of the experiments performed with and without mass transfer showed that the coalescence dynamics are not affected by mass transfer. A bimodal rest time distribution was observed when the copper sulfate solution was in the continuous phase. The surface flows and cell-like structures observed on the droplet interface are presumed to be because of a Marangoni convection, which is caused by concentration changes because of extraction. The presence and absence of surface flow is anticipated to lead to a bimodal rest time distribution. The presence of surface flow improves coalescence probability because of very short binary droplet rest times.