Longer Dwell Times Research Articles

The Effect of Body Expressions on the Learning Process and Facial Recognition among Healthy Participants and Individuals with Traumatic Brain Injury: Examination Using Eye Movements.

Context-dependent effect (CDE) is a process by which reinstating at test the original learning context enhances the recall ability of the material being studied. Although recognition by people with traumatic brain injury (TBI) is poorer than that of healthy controls, both groups show CDE equally. In the current study, we seek to test the effect of body emotional expressions as contextual information, on facial recognition, and eye movements. Twenty-four healthy individuals and 27 patients with moderate-to-severe TBI participated in the study. Participants were exposed to photos of people with neutral facial and body expressions and were asked to remember the people for a subsequent memory test. In the testing session, they were asked to determine whether the person presented to them had appeared before, under two conditions: (1) where the context remains constant (facial and body expressions remained neutral-Repeat condition) and (2) where the context changes (facial expression remained neutral but the body expression changed to angry or happy-Re-pair condition). While the memory of the individuals with TBI was poorer than that of the controls, both groups exhibited equal CDE. We found that both groups, controls more than TBI, spent most of their time looking at the head. Furthermore, longer dwell time was associated with better recognition in the study phase. These findings are consistent with previous studies showing that despite impaired memory following TBI compared to a control group, CDE was preserved. The current study extends the context effect to body postures that express emotion.

Indoor air quality in elderly care centers: A multidisciplinary approach

Studying the indoor air quality (IAQ) of elderly care centers (ECCs) has important implications for ensuring residents' health and safety. This study involves a multidisciplinary analysis of chemical and microbiological pollutants, comfort parameters and potential pathogens in five ECCs to determine the IAQ in the spaces with the longest dwell time, dining room and TV room.In general, the average concentrations of CO, CH2O, and particles were greater in the dining rooms which can be attributed to the dining room's closer location to the kitchen. The layout of these areas plays a significant role, as facilities with kitchens that are not separated from the dining room exhibited poorer IAQ.Certain pathogenic-related microbes (e.g. Cutibacterium, Sphingomonas, Fusobacterium, Malassezia) were identified in air samples. In general, such genera were positively correlated with particles, CH2O and NO2 concentrations and decreased when air purification was applied. Bacterial community composition was similar among rooms and strongly depended on ECC and purification, suggesting that human occupants are the main source of airborne bacteria. Airborne fungal communities did not depend on ECC or air purification, but particles concentrations were the main explanatory variable for their composition in indoor environments.A moderate non-carcinogenic risk due to inhalation of CH2O (2.69) and PM2.5 (1.44) was observed in the studied ECCs, so natural ventilation is not sufficient to obtain adequate IAQ. The installation of supplementary ventilation systems or the use of air purifiers would be advisable to avoid health risk, especially considering the vulnerability of the residents.

Aging impairs reactive attentional control but not proactive distractor inhibition.

Older adults tend to be more prone to distraction compared with young adults, and this age-related deficit has been attributed to a deficiency in inhibitory processing. However, recent findings challenge the notion that aging leads to global impairments in inhibition. To reconcile these mixed findings, we investigated how aging modulates multiple mechanisms of attentional control by tracking the timing and direction of eye movements. When engaged in feature-search mode and proactive distractor suppression, older adults made fewer first fixations to the target but inhibited the task-irrelevant salient distractor as effectively as did young adults. However, when engaged in singleton-search mode and required to reactively disengage from the distractor, older adults made significantly more first saccades toward the task-irrelevant salient distractor and showed increased fixation times in orienting to the target, longer dwell times on incorrect saccades, and increased saccadic reaction times compared with young adults. Our findings reveal that aging differently impairs attentional control depending on whether visual search requires proactive distractor suppression or reactive distractor disengagement. Furthermore, our oculomotor measures reveal both age-related deficits and age equivalence in various mechanisms of attention, including goal-directed orienting, selection history, disengagement, and distractor inhibition. These findings help explain why conclusions of age-related declines or age equivalence in mechanisms of attentional control are task specific and reveal that older adults do not exhibit global impairments in mechanisms of inhibition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Young Children of Mothers with a History of Depression Show Attention Bias to Sad Faces: An Eye-tracking Study

Maternal depression is a predictor of the emergence of depression in the offspring. Attention bias (AB) to negative emotional stimuli in children may serve as a risk factor for children of depressed parents. The present study aimed to examine the effect of maternal major depressive disorder (MDD) history on AB to emotional faces in children at age four, before the age of onset for full-blown psychiatric symptoms. The study also compared AB patterns between mothers and their offspring. Fifty-eight mothers and their four-year-old children participated in this study, of which 27 high-risk (HR) children had mothers with MDD during their children’s lifetime. Attention to emotional faces was measured in both children and their mothers using an eye-tracking visual search task. HR children exhibited faster detection and longer dwell time toward the sad than happy target faces. The low-risk (LR) children also displayed a sad bias but to a lesser degree. Children across both groups showed AB towards angry target faces, likely reflecting a normative AB pattern. Our findings indicate that AB to sad faces may serve as an early marker of depression risk. However, we provided limited support for the mother-child association of AB. Future research is needed to examine the longitudinal intergenerational transmission of AB related to depression and possible mechanisms underlying the emergence of AB in offspring of depressed parents.

General regulatory factors exert differential effects on nucleosome sliding activity of the ISW1a complex

BackgroundChromatin dynamics is deeply involved in processes that require access to DNA, such as transcriptional regulation. Among the factors involved in chromatin dynamics at gene regulatory regions are general regulatory factors (GRFs). These factors contribute to establishment and maintenance of nucleosome-depleted regions (NDRs). These regions are populated by nucleosomes through histone deposition and nucleosome sliding, the latter catalyzed by a number of ATP-dependent chromatin remodeling complexes, including ISW1a. It has been observed that GRFs can act as barriers against nucleosome sliding towards NDRs. However, the relative ability of the different GRFs to hinder sliding activity is currently unknown.ResultsConsidering this, we performed a comparative analysis for the main GRFs, with focus in their ability to modulate nucleosome sliding mediated by ISW1a. Among the GRFs tested in nucleosome remodeling assays, Rap1 was the only factor displaying the ability to hinder the activity of ISW1a. This effect requires location of the Rap1 cognate sequence on linker that becomes entry DNA in the nucleosome remodeling process. In addition, Rap1 was able to hinder nucleosome assembly in octamer transfer assays. Concurrently, Rap1 displayed the highest affinity for and longest dwell time from its target sequence, compared to the other GRFs tested. Consistently, through bioinformatics analyses of publicly available genome-wide data, we found that nucleosome occupancy and histone deposition in vivo are inversely correlated with the affinity of Rap1 for its target sequences in the genome.ConclusionsOur findings point to DNA binding affinity, residence time and location at particular translational positions relative to the nucleosome core as the key features of GRFs underlying their roles played in nucleosome sliding and assembly.

The Role of MXene Surface Terminations on Peptide Transportation in Nanopore Sensing.

Nanopores with two-dimensional materials have various advantages in sensing, but the fast translocation of molecules hinders their scale-up applications. In this work, we investigate the influence of -F, -O, and -OH surface terminations on the translocation of peptides through MXene nanopores. We find that the longest dwell time always occurs when peptides pass through the Ti3C2O2 nanopores. This elongated dwell time is induced by the strongest interaction between peptides and the Ti3C2O2 membrane, in which the van der Waals interactions dominate. Compared to the other two MXene nanopores, the braking effect is indicated during the whole translocation process, which evidence the advantage of Ti3C2O2 in nanopore sensing. Our work demonstrates that membrane surface chemistry has a great influence on the translocation of peptides, which can be introduced in the design of nanopores for a better performance.

2D and 3D characterization of oxidation‐fatigue mechanisms in an advanced Ni‐based superalloy: Effects of microstructure and elevated temperature

AbstractThe effects of varying γ′ size and grain boundary carbide distribution at elevated temperatures on the fatigue behavior of turbine disk alloy RR1000 were examined through combining 2D and 3D imaging characterization. The fatigue crack growth rate at 725°C is higher than at 650°C due to enhanced oxidation damage at higher temperature, dominated by an intergranular fracture mode. This is more marked with longer dwell time (linked to diffusion time) and when carbides have formed continuously at grain boundaries. The fatigue crack path was characterized by X‐ray CT scan to present the complex 3D crack propagation morphology. It is noted that a discontinuous crack path and uncracked ligaments can be discerned ahead of the crack tip particularly in the microstructure where carbides are continuously formed at grain boundaries. This is linked to embrittled zones ahead of the crack tip formed during longer dwell times at the maximum stress during cycling at elevated temperature.

The Effect of Process Parameters on the Temperature and Stress Fields in Directed Energy Deposition Inconel 690 Alloy.

Additive manufacturing (AM) technology has the advantages of designability, short process times, high flexibility, etc., making it especially suitable for manufacturing complex high-performance components for high-end industrial systems. However, the intensive temperature gradients caused by the rapid heating and cooling processes of AM can generate high levels of residual stresses, which directly affect the precision and serviceability of the components. Taking Inconel 690 alloy, which is widely used in nuclear power plants, as the research object, a thermo-coupled mechanical model of temperature field and residual stress field of directed energy deposition (DED) of Inconel 690 was established based on ABAQUS 2019 finite element software to study the influence of process parameters on the temperature history and the distribution of residual stresses in the DED process. The experimental results show that the peak temperature of each layer in the fabrication process increases with the increase in laser power and preheating temperature, and decreases with the increase in scanning speed and interlayer dwell time. Substrate preheating only has a large effect on the peak temperature of the first four layers. Residual stresses are mainly concentrated in the upper and middle parts, the bottom of the substrate, and the sides combined with the substrate, and the residual stresses increase with the increasing laser power and decrease with the increasing interlayer dwell time. Decreasing laser power, longer dwell time, higher preheating temperature, and appropriate scanning speed are beneficial for the reduction in residual stresses in Inconel 690 components. This research has important significance for the process design and residual stress modulation in the additive manufacturing of Inconel 690 alloy.

Intra-arterial Peptide Receptor Radionuclide Therapy for the Treatment of Hepatic Neuroendocrine Tumor Metastases: Hope or Hype?

Peptide receptor radionuclide therapy (PRRT) confers significant progression-free survival advantage for patients with small bowel grade 1 and 2 well-differentiated neuroendocrine tumors (WD NET). PRRT may also be clinically beneficial for patients with NET of pancreatic, bronchial, and other sites of origin; patients with paragangliomas; as well as for patients with well-differentiated grade 3 NET. Direct intra-arterial (IA) administration of PRRT into the hepatic artery for patients with NET liver metastases may result in higher radiopharmaceutical dose and longer dwell time in the liver tumors while relatively sparing non-tumor liver tissue and other organs such as the kidneys and bone marrow when compared with intravenous (IV) administration. This review summarizes currently available data on IA and IV PRRT dose distribution, reports safety and efficacy of IA PRRT, and proposes future research questions.

Exploration of the Current State of Peripheral Intravenous Catheter Complications and Documentation: A Point Prevalence Study.

Peripheral intravenous catheters (PIVCs) are the most commonly used invasive devices in acute care hospitals, with nurses being primarily responsible for the insertion and care of these devices. This point prevalence study aimed to describe current PIVC status and nursing documentation in a large, regional health care system and to explore variables associated with PIVC complications. The study was conducted with adult inpatients. There were 665 PIVCs included in the study. Dressings were clean, dry, and intact in 83% of observations; only 2.7% did not have a transparent dressing. Thirty-one percent of PIVCs were inserted in areas of flexion. Median dwell time was 2.39days (± 2.36days), with upper arm sites having the longest dwell time. Overall inter-rater reliability (IRR) for an infiltration or phlebitis score of 0 was high (97.4% and 92%, respectively). However, overall agreement was only 77.16% for infiltration and 40.07% for phlebitis, with significant disagreement as scores increased. Study findings support that there was strong compliance with the Infusion Nurses Society's (INS) Infusion Therapy Standards of Practice vascular access practice recommendations; however, opportunities to improve infiltration/phlebitis assessment and documentation exist.

Study of compaction tools and parameters on critical quality attributes of high drug load minitablets

Minitablets are prepared using multiple die openings and multi–tip punches for greater productivity. With multiple tips on the punch barrel, the overall compaction force to be applied is commonly estimated by multiplying the desired compaction force per tip by the number of punch tips. Few researchers have however examined this proportionality and the effects of the number of punch tips and punch face geometry on the critical quality attributes (CQAs) of high drug load minitablets. In this study, the minitablets prepared by multi–tip tools exhibited greater weight variation than those prepared by single–tip tools. Their compaction was accompanied by a longer dwell time that led to a higher minitablet tensile strength and consequently a longer disintegration time. The compaction forces required to achieve a consistent set of minitablet CQAs were not directly proportional to the number of punch tips used. In comparison, the effect of punch face geometry was negligible. Increasing concentration of magnesium stearate (as lubricant) from 0.75 to 1.25 %, w/w reduced weight variation, especially of minitablets prepared by the multi-tip tools. It also increased the disintegration time but had no significant effect on the tensile strength of the minitablets regardless of type of tools used. The adjustment of compaction speed was an effective compensatory method to mitigate the differences in dwell time and tensile strength between minitablets prepared by single–tip and multi–tip standard concave tools. A larger reduction in compaction speed of the single-tip tools was required at higher compaction pressures.

Mixing measurement on hydrogen jet by LIBS under various injection strategies

Favorable fuel properties of hydrogen for combustion system opens a new avenue to achieve deep decarbonization in transportation sector. Meanwhile, various technical challenges including low volumetric energy density, nitrogen oxide emissions, and backfire impede successful implementation of hydrogen in combustion engines. To overcome those issues, stratified charge combustion (SCC) is considered to optimize engine performance and emissions. As direct injection approach is utilized in SCC mode, ensuring quality of air-fuel mixing in combustion chamber is crucial. This study aims to understand hydrogen mixing behavior by quantitative measurement on equivalence ratio using laser-induced breakdown spectroscopy (LIBS). This measurement has been conducted under non-reacting conditions, employing realistic injection strategy, multiple injection, so the influences of dwell time, and split ratio are addressed. In addition to LIBS, this study includes a morphological analysis of the hydrogen jet, which was visualized using high-speed schlieren imaging. The experimental data showed that shorter first injection duration was resulted in an increased jet width at the spark plug location, which reduced the equivalence ratio within the center of the jet. Longer dwell time also demonstrated wider jet width at the spark plug location, reducing the equivalence ratio within the center of the jet.

Evaluation of Electric Vehicle Charging Usage and Driver Activity

As the country moves toward electric vehicles (EV), the United States is in the process of investing over USD 7.5 billion in EV charging stations, and Indiana has been allocated $100 million to invest in their EV charging network. In contrast to traditional “gas stations”, EV charging times, depending on the charger power delivery rating, can require considerably longer dwell times. As a result, drivers tend to pair charging with other activities. This study looks at two EV public charging locations and monitors driver activity while charging, charge time, and station utilization over a 2-month period in Lafayette, Indiana. Over 4000 charging sessions at stations with varying power levels (350 kW, 150 kW, and 50 kW) were monitored, and the median charge time was between 28 and 36 min. A large variation in station utilization was observed at Electrify America charging stations that had a range of stations with 350 kW, 150 kW, and 50 kW available. The highest utilization rates by hour of day on average were observed at 25% at the 150 kW Tesla station. Driver activity during charging influenced dwell times, with the average dwell time of drivers who waited in their vehicles to charge being 10 min shorter than those who would travel to the shops. Rain in the forecast also impacted the number of users per day. Although there are no published metrics for EV utilization and associated driver activities, we believe examining this relationship will produce best practices for planning future investments in EV charging infrastructure as public and private sector partners develop a nationwide charging network.

Influence of sintering parameters on the microstructure and mechanical properties of WC-Co hardmetals

The influence of sintering temperature, dwelling time at maximum temperature and carbon content on the microstructure and on the mechanical and magnetic properties of WC-6%Co hardmetal was investigated. Samples were sintered according to a central composite design and subsequently analysed with respect to microstructural parameters (average WC grain size, binder mean free path and contiguity), as well as mechanical (hardness, transverse rupture strength and toughness) and magnetic (magnetic saturation and coercivity) properties. Microstructural parameters were determined using a Matlab®-based program developed for the evaluation of EBSD images. Results show that in order to maximize both hardness and TRS sintering should be performed in the low temperature range, i.e. < 1400 °C, while dwelling time should not be too short, at least 75 min. This is particularly important for low carbon parts, since longer dwelling times are required to provide the microstructure with the necessary homogeneity required for high TRS.

Mobility-aware Vehicular Cloud formation mechanism for Vehicular Edge Computing environments

Rapid advancements in vehicular technology and increased vehicle modernization have led to the emergence of intelligent and interconnected entities. As a result, the Vehicular Edge Computing (VEC) paradigm has gained prominence. This paradigm enables the provision of cloud computing services close to vehicular users by utilizing the idle computational resources of vehicles to execute tasks that require computing power beyond what is available locally. Aggregating these computational resources in the vehicular context is known as Vehicular Cloud (VCloud) formation. However, leveraging and aggregating these resources poses several challenges due to the dynamic nature of the vehicular environment. One of the main challenges is the efficient selection of vehicles to assume management roles in the distribution of computational power within the group, often referred to as leading vehicles. This research presents a mobility-aware mechanism called PREDATOR to enhance the VCloud formation process. In this mechanism, the Roadside Unit (RSU) provides vehicular mobility predictions, enabling the selection of the most stable vehicles within the RSU coverage area to assume leadership roles in the VCloud. In this context, vehicle stability is associated with a vehicle’s time within the RSU coverage area, known as dwell time. PREDATOR employs a microscopic perspective to select vehicles with the longest dwell time in the VCloud, allowing for efficient management of computational resource utilization. Simulation results have demonstrated that PREDATOR not only increases the VCloud lifetime but also minimizes leader changes, reduces network message exchange, mitigates packet collisions, and facilitates the effective utilization of aggregated vehicular resources compared to state-of-the-art approaches.

The effect of TEMPOL pretreatment on postoperative cognitive function, inflammatory response, and oxidative stress in aged rats under sevoflurane anesthesia.

The heterocyclic compound 4-hydroxy-(2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPOL) has a protective effect on neurological function in brain tissues damaged by ischemia and hypoxia. This study explored the effects of TEMPOL pretreatment on postoperative cognitive function in aged rats under sevoflurane anesthesia, focusing on inflammatory response and oxidative stress. Sixty male rats were divided into normal control (C), sevoflurane anesthesia (S), TEMPOL pretreatment (T), and sevoflurane anesthesia + TEMPOL pretreatment (ST) groups (15 per group). Groups T and ST rats received continuous intraperitoneal TEMPOL (100 mg/kg) for 3 days, while groups C and S rats were injected with 0.9% saline. After pretreatment, groups S and ST received 3% sevoflurane anesthesia. Rats in group S exhibited a longer swimming distance, longer escape latency, lower frequency of platform crossing, and shorter dwell time in the targeted quadrant than those in groups C and T. Rats in group ST exhibited a shorter swimming distance, shorter escape latency, higher frequency of platform crossing, and longer dwell time in the targeted quadrant than those in group S. The expressions of interleukin-6, tumor necrosis factor-α, inducible nitric oxide synthase, and Ym1/2 messenger ribonucleic acid were higher in groups S and ST rats than in groups C and T rats and lower in group ST rats than in group S rat (p < .05). Superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px) were lower, while malondialdehyde (MDA) was higher in groups S and ST rats than in groups C and T rats (p < .05). Group ST showed higher SOD, T-AOC, and GSH-Px, and lower MDA than group S (p < .05). TEMPOL pretreatment attenuated postoperative cognitive impairment induced by sevoflurane anesthesia in aged rats. This may be attributed to the downregulation of NR2B-CREB-BDNF pathway, reducing the inflammatory response and oxidative stress damage in hippocampal tissue.

Investigating the Thermo-Optic Properties of BCZT-Based Temperature Sensors.

Photoluminescent (PL) layers and electroluminescent (EL) systems have gained significant attention for their applications in constructing flat panels, screen monitors, and lighting systems. In this study, we present a groundbreaking approach to fabricating temperature sensors using barium-calcium zirconium titanate (BCZT) with thermo-optic properties, leading to the development of opto-thermal sensors for electric vehicle battery packs. We prepared zinc sulfide (ZnS) fluorescent films on BCZT ceramics, specifically two optimal compositions, BCZT0.85 (Ba0.85Ca0.15Zr0.1Ti0.9O3) and BCZT0.9 (Ba0.9Ca0.1Zr0.1Ti0.9O3), via the solid-state reaction method for the dielectric layer. The BCZT powders were calcined at varying temperatures (1200 and 1250 °C) and dwell times (2 and 4 h). The resulting phase formation and microstructure characteristics were analyzed using X-ray diffraction and scanning electron microscopy, respectively. Our investigation aimed to establish a correlation between the dielectric behavior and optical properties to determine the optimal composition and conditions for utilizing BCZT as thermal detectors in electric vehicle battery packs. All BCZT powders exhibited a tetragonal phase, as confirmed by JCPDS No. 01-079-2265. We observed an increase in the dielectric constant with higher calcining temperatures or longer dwell times. Remarkably, BCZT0.85 ceramic sintered at 1250 °C for 4 h displayed the highest dielectric constant of 15,342, establishing this condition as optimal for preparing the dielectric film with a maximum dielectric constant of 42. Furthermore, we investigated the temperature-dependent electroluminescence intensity of the samples, revealing a significant enhancement with increasing temperature, reaching its peak at 80 °C. Additionally, we observed a positive correlation between electroluminescence intensity and dielectric constant, indicating the potential for improved opto-thermal sensors. The findings from this study offer promising opportunities for the development of advanced opto-thermal sensors with potential applications in electric vehicle battery packs. Our work contributes to the expanding field of photoluminescent and electroluminescent systems by providing novel insights into the design and optimization of efficient and reliable sensors for thermal monitoring in electric vehicle technologies.

Efficacy and Safety of Adjunctive and Primary Use of the TightRail Mechanical Cutting Sheath for Lead Extraction.

Rotational cutting tools are increasingly used in transvenous lead extraction. There are limited data on their safety and efficacy, particularly when used adjunctively for stalled progression. The aim of this study was to evaluate the utilization, safety, and effectiveness of mechanical rotational cutting tools for transvenous lead extraction. Patients undergoing transvenous lead extraction at a single tertiary center (April 2015 to January 2021, n=586) were included in this retrospective analysis. The study characterized the 251 patients (42.8%) whose cases involved the TightRail mechanical cutting tool. Among 251 patients, 526 leads were extracted and TightRail was used for 70.5%. The TightRail was used adjunctively with the laser for 65.2% of leads, 97.8% of the time as the second tool after stalled progression. Using a multivariable logistic regression model, we found that active-fixation leads (odds ratio, 2.78 [95% CI, 1.62-4.78]; P=0.0002), dual-coil leads (odds ratio, 3.39 [95% CI, 1.87-6.16]; P<0.0001), and lead dwell time (odds ratio, 1.16 [95% CI for 1-year increase, 1.11-1.21]; P<0.0001) were factors independently associated with adjunctive TightRail use. Stalled progression requiring TightRail occurred most often in the innominate vein and superior vena cava (59.3%). The clinical success rate was 96.8%, and the rate of major adverse events was 2.8%. Only 1 major adverse event was observed during TightRail use. Rotational cutting with TightRail was used in 42.8% of transvenous lead extractions, predominantly in an adjunctive manner after stalled laser progression in the innominate vein and superior vena cava, and more frequently for dual-coil and leads with longer dwell times. Adjunctive TightRail use carries a low risk of major complications.

Evaluating the Effectiveness of Environmental Interpretation in National Parks Based on Visitors’ Spatiotemporal Behavior and Emotional Experience: A Case Study of Pudacuo National Park, China

Problems such as global environmental pollution and climate change have made the public’s desire for nature and closeness to greenery increasingly strong amid rapid urbanization. Improving the ability of experiential environmental interpretation products and services is the basis for national parks to meet the public’s needs, and the evaluation of their effectiveness is a necessary basis for optimizing the quality of environmental interpretation services in response to the current problems of unsynchronized environmental interpretation facilities and service levels. Using Pudacuo National Park as a case study, 365 visitors’ spatio-temporal trajectories with GPS devices and questionnaire data were collected, and the interaction changes of visitors’ external spatiotemporal behaviors and internal emotional experiences were analyzed using cluster analysis, GPS geoprocessing model construction, and emotional mean calculation methods, and the results showed that (1) Pudacuo National Park visitors mainly comprise four types of visitor clusters, which are the sightseeing type, trekking + sightseeing type, cruise type, and hiking + cruise type, as well as four types of spatio-temporal behavior patterns; the differences of visitors’ spatiotemporal behavior patterns are reflected in spatial movement, time allocation, and stopping behavior, and correspond to different emotional experience intensity. (2) Emotional experience value is positively correlated with location stay time, and emotional experience intensity is higher, corresponding to spatio-temporal behavior patterns with longer trajectory distance, longer dwell time, and more stopping behaviors, indicating that environmental services promote longer visitor stopping time and generate high-quality recreation experiences. (3) Finally, we proposed the optimization of environmental interpretation mode according to the spatiotemporal emotional differences of different types of visitor clusters. This study provides a basis for improving the quality of visitor experience and optimizing the quality of environmental interpretation services and provides a useful reference for guiding the construction of high-quality and diverse ecological experiences in national parks.

Quantitative LC-MS/MS. 1. Impact of Points across a Peak on the Accuracy and Precision of Peak Area Measurements.

The number of points across a chromatographic peak has long been recognized as a key determinant of the accuracy and precision of the measured peak area. In LC-MS-based quantitation experiments in drug discovery and development, the "rule-of-thumb" has been to use 15 or more points. This "rule" is based on the literature describing chromatographic methods where the goal was to achieve the lowest possible imprecision in the measurements, especially when unknown analytes are being detected. Restricting methods to the requirement of at least 15 points across a peak can be detrimental to the development methods that fully optimize the signal-to-noise ratio for the assay using longer dwell times and/or transition summing. This study aims to show that 7 points across the peak for peaks that are 9 s or less wide provide more than sufficient accuracy and precision for drug quantitation studies. Data from simulated Gaussian curves using a sampling interval of 7 points across the peak gave peak area calculations within 1% of the expected total peak area using the Trapezoidal and Riemann rules and 0.6% for the Simpson rule. Low and high concentration samples (n = 5) were assayed using three different LC methods on three different days on two different instruments (API5000 and API5500). The difference in peak area (%ΔPA) and relative standard deviation of the peak areas (%RSD) was less than ∼5%. No significant difference was observed from the data that were obtained from different sampling intervals, different peak widths, different days, different peak sizes, and different instruments. Three core analytical runs were performed on three different days. In each core run, the lower limit of quantitation (LLOQ, n = 5), low quality control (LQC, n = 5), middle quality control (MQC, n = 5), and high-quality control samples (HQC, n = 5) were processed and run simultaneously with a standard curve. The range of the intra- and interday accuracy and precision for 3 core runs was 98.0-105% and 0.9-3.0% for 7 data points and 97.5-105% and 0.8-4.3% for 17 data points, respectively. No significant difference was observed for the different sampling intervals. The results show a sampling interval of 7 points for peaks up to 9 s wide is sufficient to define a peak accurately and precisely for drug quantitation studies in drug discovery and development.