bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of tropical land-use change on downstream riverine and estuarine water properties and biogeochemical cycles: a review
Authors: Tanaka Yasuaki , Minggat Elizerberth , Roseli Wardina
Published: June 2021

Tropical primary forests have been disappearing quickly to make use of the land for commercial purposes. Land-use change has an impact on downstream aquatic processes, but those impacts have mainly been studied in temperate climate regions. The present article reviews the impacts of various tropical land-use changes caused by human activities on downstream riverine and estuarine water properties and biogeochemical cycles, focusing especially on the behaviors of nitrogen (N) and phosphorus (P). Logging of tropical primary forests, subsequent establishment of pasture lands, and occasional wildfire or intentional burning have decreased terrestrial N fixation and increased the discharge of P combined with soils, which has lowered the N:P ratio of dissolved inorganic nutrients in the adjacent stream waters and downstream rivers. Agricultural fertilizers and aquacultural practices basically cause nutrient enrichment in downstream riverine and estuarine waters, changing the N:P ratio depending on the source. Finally, urbanization causes eutrophication in many tropical estuaries, where a halocline forms easily because of a warm temperature throughout the year and the water at the bottom of the estuary tends to become hypoxic or anoxic. Overall, the impact of land-use change on aquatic processes may be more serious in tropical regions than in temperate or cold climate regions because of (1) a higher biomass and nutrient stock in original tropical forests; (2) higher precipitation, more frequent episodic flooding, and warmer temperatures in tropical regions; and (3) certain practices that are rapidly expanding in tropical regions such as land-based aquaculture. Various land-use changes are causing downstream nutrient enrichment or disturbance of the nutrient balance at tropical land-sea interfaces, and the overall N:P ratios in the aquatic ecosystem seem to be declining. Nonetheless, if proper management is conducted and the discharge of nutrients and soils ceases, tropical aquatic systems may have the potential to recover faster than those in other climate regions because of their abundant precipitation and warm temperature. Long-term monitoring and more attention to elemental stoichiometry are important areas for future research.
Natural nasal–esophageal fiberscopy in the COVID-19 pandemic—preventing sneezing without anesthesia: a case report
Authors: Tsunoda Koichi , Hentona Ko , Yamanobe Yoshiharu
Published: June 2021

Background

We are laryngologists. We observe natural phonatory and swallowing functions in clinical examinations with a trans-nasal laryngeal fiberscope (TNLF). Before each observation, we use epinephrine to enlarge and smooth the common nasal meatus (bottom of nostril) and then insert a wet swab inside the nose, as in taking a swab culture in the nasopharynx. During the current COVID-19 pandemic situation, this careful technique prevents any complications, including nasal bleeding, painfulness, and induced sneezing. Here, we introduce our routine to observe esophageal movement in swallowing in a natural (sitting) position without anesthesia.

Case presentation

The case was a 70-year-old female who complained that something was stuck in her esophagus; there was a strange sensation below the larynx and pharynx. After enlarging and smoothing the common nasal meatus, we inserted the TNLF (slim type ⌀2.9 mm fiberscope, VNL8-J10, PENTAX Medical, Tokyo, Japan.) in the normal way. We then observed the phonatory and swallowing movements of the vocal folds. As usual, to not interfere with natural movements, we used no anesthesia. We found no pathological condition in the pyriform sinus. We asked the patient to swallow the fiberscope. During the swallow, we pushed the TNLF and inserted the tip a bit deeper, which made the fiberscope easily enter the esophagus, like in the insertion of a nasogastric tube. We then asked the patient to swallow a sip of water or saliva to clear and enlarge the lumen of the esophagus. This made it possible to observe the esophagus easily without any air supply. With tone enhancement scan, the esophagus was found to be completely normal except for glycogenic acanthosis.

Conclusions

The advantage of this examination is that it is easily able to perform without anesthesia and with the patient in sitting position. It is quick and minimally invasive, enabling observation the physiologically natural swallowing. It is also possible to observe without anesthesia down to the level of the esophagogastric junction using with a thin type flexible bronchoscope. In the future, gastric fiberscopes might be thinner, even with narrow band imaging (NBI) function. Before that time, physicians should remember to just insert along the bottom of the nose.
Correction to: Percolation-Based Image Processing for the Plastic Viscosity of Cementitious Mortar with Super Absorbent Polymer
Authors: Aryanfar Asghar , Şanal Irem , Marian Jaime
Published: June 2021

An amendment to this paper has been published and can be accessed via the original article.
Exploring alternatives for adolescent anorexia nervosa: adolescent and parent treatment (APT) as a novel intervention prospect
Authors: Ganci Maria , Atkins Linsey , Roberts Marion E.
Published: June 2021

Recovery and remission rates of adolescent anorexia nervosa (AN) following Family Based Treatment (FBT) have seen a relative decline over recent years. While reasonably successful in achieving physical recovery (i.e. weight restoration), both empirical and anecdotal accounts highlight a lack of attention to the psychological recovery of the adolescent within manualised FBT. As such, there is a need for innovation to explore treatment variations and alternatives for the proportion of adolescents with AN who do not respond favourably to this first-line treatment. This paper introduces a new treatment framework to the field for clinical consideration and empirical assessment. Adolescent and Parent Treatment (APT) for adolescent AN draws from both family-based and individual treatment models, applying a developmental lens. APT attends to physical and psychological recovery simultaneously and from the start of treatment, with capacity to tailor individual psychological modules to the adolescent formulation. While clearly in its infancy, APT provides an exciting new avenue for exploration within the field, as we seek new avenues to support young people and their families to effectively combat this deadly illness.
Binge eating symptoms are associated with the severity of premenstrual symptoms among university students, cross sectional study from Palestine
Authors: Badrasawi Manal M. , Zidan Souzan J. , Natour Nihal , Sharif Israa , Atrash Shahd , Abueid Ghada , Al-Jounde Saeda
Published: June 2021

Background

Premenstrual syndrome (PMS) is considered one of the most prevailing disorders among childbearing age women that could considerably interfere with daily living activities life. PMS is underrecognized in Palestine. It is reported that binge eating symptoms are significantly related to premenstrual syndrome. In this regard, the study aimed to determine factors linked with premenstrual symptoms and to explore whether binge eating symptoms are linked with premenstrual syndrome.

Methods

This descriptive study was performed among female undergraduates at Palestine Polytechnic University, using a cross-sectional design. A self-administrated questionnaire was used in order to collect data. Moreover, participants’ nutritional status was assessed using anthropometric measurements. Descriptive statistics, independent t-test and Chi-square were performed.

Results

A sum of 289 undergraduate females were involved in the final analysis. The results indicated that nearly half of undergraduates (47.8%) were classified as having binge eating symptoms. The most frequently noted premenstrual symptoms were lethargy, anger feelings, lack of interest, and anxiety. Chi-square analysis showed that moderate and severe psychological symptoms were significantly more prevalent among females with binge eating symptoms. Besides it was found that moderate and severe physical symptoms were significantly more prevalent among females with binge eating symptoms. Moreover, participants who reported no premenstrual syndrome symptoms were significantly less prevalent among females with binge eating symptoms. The findings also reveal that sociodemographic characteristics was not significantly correlated with premenstrual syndrome symptoms. In multiple adjusted models, both smoking (p < 0.05) and binge eating (p < 0.0001) were significantly related to PMS.

Conclusion

Findings reveals that moderate and severe psychological and physical symptoms were significantly more prevalent among females with binge eating symptoms. The current research also reported that the severity of PMS was not significantly related to sociodemographic variables.
Spatial variations of school-level determinants of reading achievement in Italy
Authors: Sacco Chiara , Falzetti Patrizia
Published: June 2021

The study of the territorial difference in educational achievement is a widely debated topic, in particular in Italy for the presence of the well-known strong regional disparities. National and international large scale assessments confirmed that the main characteristic of the Italian school system is the geographical cleavage between North and South. Policymakers have pressing needs to find solutions to reduce geographical disparities. In this study, we investigate the spatial disparities of academic achievement from a new perspective, assuming that the relationship between academic achievement and predictors varies across Italy. Our aim is to examine the extent of the spatial disparities in the relationship between academic achievement and some school-level factors related to inequalities in educational outcomes, moving beyond the regional administrative confines, in order to identify new spatial patterns. We exploited the reading standardized tests administered by INVALSI in 2018–2019 focusing on the 8th-grade students. Crucial to our contribution is the use of the geographically weighted regression and the k-mean clustering, which allows studying the spatial variability of the impact of the school-level factors on academic achievement and to gather schools in new spatial clusters. The findings of this paper demonstrate the necessity to design a more specific education policy and support the identification of the main critical factors for different geographical areas.
A distributed Content-Based Video Retrieval system for large datasets
Authors: Saoudi El Mehdi , Jai-Andaloussi Said
Published: June 2021

With the rapid growth in the amount of video data, efficient video indexing and retrieval methods have become one of the most critical challenges in multimedia management. For this purpose, Content-Based Video Retrieval (CBVR) is nowadays an active area of research. In this article, a CBVR system providing similar videos from a large multimedia dataset based on query video has been proposed. This approach uses vector motion-based signatures to describe the visual content and uses machine learning techniques to extract key frames for rapid browsing and efficient video indexing. The proposed method has been implemented on both single machine and real-time distributed cluster to evaluate the real-time performance aspect, especially when the number and size of videos are large. Experiments were performed using various benchmark action and activity recognition datasets and the results reveal the effectiveness of the proposed method in both accuracy and processing time compared to previous studies.
High frequency of enterotoxin encoding genes of Staphylococcus aureus isolated from food and clinical samples
Authors: Haghi Fakhri , Zeighami Habib , Hajiloo Zeynab , Torabi Neda , Derakhshan Safoura
Published: June 2021

Background

Staphylococcus aureus is recognized as an important cause of food poisoning related to the consumption of raw, undercooked, or mishandled foods worldwide.

Methods

A total of 90 individual meat samples and 200 clinical specimens were collected and investigated the frequency of S. aureus and classical enterotoxin genes. The samples were cultured on Baird-Parker and Mannitol salt agar and subjected for confirmatory biochemical tests and molecular detection of femA, sea, seb, sec, sed, and see genes.

Results

A total of 31 (34.5%) meat samples and 81 (40.5%) clinical specimens were positive for the presence of S. aureus. These isolates were detected with slightly higher frequency in clinical specimens than food samples (P> 0.05). Furthermore, the frequency of S. aureus in raw meat (23.4%) was higher than that in cooked meat samples (11.1%) (P< 0.05). Staphylococcal enterotoxin (SE) genes were identified in 18 (58.1%) of 31 meat isolates and 42 (51.8%) of 81 clinical isolates. The frequency of SE genes (except see) in meat isolates was slightly higher than that in clinical isolates (P> 0.05). We found sea and see genes with higher frequency than others in both meat and clinical samples. Furthermore, 55.5% of meat isolates and 38.1% of clinical isolates possessed more than one se gene.

Conclusion

Detection of enterotoxigenic S. aureus in clinical and raw meat samples shows a probable risk for public health. Therefore, intensive and continuous monitoring of potentially pathogenic S. aureus is strongly recommended in order to evaluate the human health risk arising from food consumption.
G6PD deficiency among malaria-infected national groups at the western part of Myanmar with implications for primaquine use in malaria elimination
Authors: Han Kay Thwe , Han Zay Yar , Aye Kyin Hla , Wai Khin Thet , Thi Aung , Cui Liwang , Sattabongkot Jetsumon
Published: June 2021

Background

Glucose 6-phosphate dehydrogenase deficiency (G6PDd) plays a central role in readiness assessment for malaria elimination in Myanmar by 2030 that includes primaquine (PQ) use. The risk of hemolysis in G6PDd individuals hampers the widespread use of primaquine safely in malaria-infected patients. In the pre-elimination era, it is important to screen initially for asymptomatic malaria in combination with G6PD deficiency by applying more sensitive diagnostic tools. Therefore, this study examined the proportion of G6PDd and the distribution of G6PD genotypes among malaria-infected national groups in Myanmar before initiation of malaria elimination strategies.

Methods

A cross-sectional study in one township each with high malaria burden from two states in the western part of Myanmar, was conducted during 2016-2018, and 320 participants (164 Rakhine and 156 Chin National groups) were recruited. We used RDT and ultrasensitive polymerase chain reaction (us PCR) method to confirm malaria infection, and a G6PD RDT(CareStart) to detect G6PDd and PCR/restriction fragment length polymorphism (RFLP) method to confirm the variant of G6PDd for genotyping. G6PD enzyme activity was measured by G6PD Biosensor (CareStart).

Results

Malaria positivity rates detected by RDT were lower than those detected by us PCR in the combined samples [13% (42/320) vs. 21% (67/320)] as well as in the Rakhine samples [17% (28/164) vs. 25% (41/164)] and in Chin samples [9% (14/156) vs. 17% (26/156)]. G6PD deficiency rates were approximately 10% in both the combined samples and specific national groups. For G6PD enzyme activity in the combined samples, G6PDd (defined as < 30% of adjusted male median) was 10% (31/320) and severe G6PDd (< 10% of AMM) was 3% (9/320). Among malaria-infected patients with positive by both RDT and usPCR, G6PDd was less than 20% in each national group. G6PD genotyping showed that the G6PD Mahidol (G487A) was the major variant.

Conclusions

The varying degree of G6PDd detected among malaria-infected national groups by advanced diagnostic tools, strongly support the recommend G6PD testing by the National Malaria Control Program and the subsequent safe treatment of P. vivax by primaquine for radical cure. Establishing a field monitoring system to achieve timely malaria elimination is mandatory to observe the safety of patients after PQ treatment.
Biologic Assignment Trial of Reduced-Intensity Hematopoietic Cell Transplantation Based on Donor Availability in Patients 50-75 Years of Age With Advanced Myelodysplastic Syndrome
Authors: Nakamura Ryotaro , Saber Wael , Martens Michael J. , Ramirez Alyssa , Scott Bart , Oran Betul , Leifer Eric , Tamari Roni , Mishra Asmita , Maziarz Richard T. , McGuirk Joseph , Westervelt Peter , Vasu Sumithira , Patnaik Mrinal , Kamble Rammurti , Forman Stephen J. , Sekeres Mikkael A. , Appelbaum Frederick , Mendizabal Adam , Logan Brent , Horowitz Mary , Cutler Corey
Published: June 2021

PURPOSE

Allogeneic hematopoietic cell transplantation (HCT) is the only potentially curative therapy for myelodysplastic syndromes (MDS), although it is infrequently offered to older patients. The relative benefits of HCT over non-HCT therapy in older patients with higher-risk MDS have not been defined.

METHODS

We conducted a multicenter biologic assignment trial comparing reduced-intensity HCT to hypomethylating therapy or best supportive care in subjects 50-75 years of age with intermediate-2 or high-risk de novo MDS. The primary outcome was overall survival probability at 3 years. Between January 2014 and November 2018, we enrolled 384 subjects at 34 centers. Subjects were assigned to the Donor or No-Donor arms according to the availability of a matched donor within 90 days of study registration.

RESULTS

The median follow-up time for surviving subjects was 34.2 months (range: 2.3-38 months) in the Donor arm and 26.9 months (range: 2.4-37.2 months) in the No-Donor arm. In an intention-to-treat analysis, the adjusted overall survival rate at 3 years in the Donor arm was 47.9% (95% CI, 41.3 to 54.1) compared with 26.6% (95% CI, 18.4 to 35.6) in the No-Donor arm ( P = .0001) with an absolute difference of 21.3% (95% CI, 10.2 to 31.8). Leukemia-free survival at 3 years was greater in the Donor arm (35.8%; 95% CI, 29.8 to 41.8) compared with the No-Donor arm (20.6%; 95% CI, 13.3 to 29.1; P = .003). The survival benefit was seen across all subgroups examined.

CONCLUSION

We observed a significant survival advantage in older subjects with higher-risk MDS who have a matched donor identified and underwent reduced-intensity HCT, when compared with those without a donor. HCT should be included as an integral part of MDS management plans in fit older adults with higher-risk MDS.
Relationship Between Intraoperative and Preoperative Ambulatory Nighttime Heart Rates: A Secondary Analysis of a Prospective Observational Study
Authors: Kouz Karim , Hoppe Phillip , Reese Philip , Burfeindt Christian , Flick Moritz , Briesenick Luisa , Nitzschke Rainer , Pinnschmidt Hans , Saugel Bernd
Published: June 2021

BACKGROUND:

It remains unknown what constitutes physiologically relevant intraoperative bradycardia. Intraoperative bradycardia is usually defined using absolute heart rate thresholds, ignoring preoperative baseline heart rates. In contrast, we considered defining intraoperative bradycardia relative to preoperative ambulatory nighttime heart rate. Specifically, we hypothesized that the individual mean intraoperative heart rate is lower than the mean preoperative ambulatory nighttime heart rate. We, therefore, sought to investigate the relationship between the intraoperative and preoperative ambulatory nighttime heart rates in adults having noncardiac surgery with general anesthesia. Additionally, we sought to investigate the incidence of intraoperative bradycardia using relative versus absolute heart rate thresholds.

METHODS:

We conducted a secondary analysis of a database from a prospective study including preoperative ambulatory and intraoperative heart rates in 363 patients having noncardiac surgery with general anesthesia.

RESULTS:

The mean intraoperative heart rate was lower than the mean nighttime heart rate (mean difference, −9 bpm; 95% confidence interval [CI], −10 to −8 bpm; P < .001). The mean intraoperative heart rate was lower than the mean nighttime heart rate in 319 of 363 patients (88%; 95% CI, 84%–91%). The incidence of intraoperative bradycardia was 42% (95% CI, 38%–47%) when it was defined as intraoperative heart rate >30% lower than mean nighttime heart rate and 43% (95% CI, 38%–49%) when it was defined as intraoperative heart rate <45 bpm.

CONCLUSIONS:

The mean intraoperative heart rate is lower than the mean nighttime heart rate in about 9 of 10 patients. Intraoperative bradycardia might thus be physiologically and clinically important. Future research needs to investigate whether there is an association between intraoperative bradycardia and postoperative outcomes.
Neither Peristaltic Pulse Dynamic Compressions nor Heat Therapy Accelerate Glycogen Resynthesis after Intermittent Running
Authors: KIM KYOUNGRAE , KARGL CHRISTOPHER K. , RO BOHYUN , SONG QIFAN , STEIN KIMBERLY , GAVIN TIMOTHY P. , ROSEGUINI BRUNO T.
Published: June 2021

Purpose

To investigate the effects of a single session of either peristaltic pulse dynamic leg compressions (PPDC) or local heat therapy (HT) after prolonged intermittent shuttle running on skeletal muscle glycogen content, muscle function, and the expression of factors involved in skeletal muscle remodeling.

Methods

Twenty-six trained individuals were randomly allocated to either a PPDC (n = 13) or a HT (n = 13) group. After completing a 90-min session of intermittent shuttle running, participants consumed 0.3 g·kg−1 protein plus 1.0 g·kg−1 carbohydrate and received either PPDC or HT for 60 min in one randomly selected leg, while the opposite leg served as control. Muscle biopsies from both legs were obtained before and after exposure to the treatments. Muscle function and soreness were also evaluated before, immediately after, and 24 h after the exercise bout.

Results

The changes in glycogen content were similar (P > 0.05) between the thigh exposed to PPDC and the control thigh ~90 min (Control: 14.9 ± 34.3 vs PPDC: 29.6 ± 34 mmol·kg−1 wet wt) and ~210 min (Control: 45.8 ± 40.7 vs PPDC: 52 ± 25.3 mmol·kg−1 wet wt) after the treatment. There were also no differences in the change in glycogen content between thighs ~90 min (Control: 35.9 ± 26.1 vs HT: 38.7 ± 21.3 mmol·kg−1 wet wt) and ~210 min (Control: 61.4 ± 50.6 vs HT: 63.4 ± 17.5 mmol·kg−1 wet wt) after local HT. The changes in peak torque and fatigue resistance of the knee extensors, muscle soreness, and the mRNA expression and protein abundance of select factors were also similar (P > 0.05) in both thighs, irrespective of the treatment.

Conclusions

A single 1-h session of either PPDC or local HT does not accelerate glycogen resynthesis and the recovery of muscle function after prolonged intermittent shuttle running.
Sex Differences in Neuromuscular Fatigue and Changes in Cost of Running after Mountain Trail Races of Various Distances
Authors: BESSON THIBAULT , PARENT AUDREY , BROWNSTEIN CALLUM G. , ESPEIT LOÏC , LAPOLE THOMAS , MARTIN VINCENT , ROYER NICOLAS , RIMAUD DIANA , SABATER PASTOR FREDERIC , SINGH BENJAMIN , VARESCO GIORGIO , ROSSI JEREMY , TEMESI JOHN , MILLET GUILLAUME Y.
Published: June 2021

Introduction

Women have been shown to experience less neuromuscular fatigue than men in knee extensors (KE) and less peripheral fatigue in plantar flexors (PF) after ultratrail running, but it is unknown if these differences exist for shorter trail running races and whether this may impact running economy. The purpose of this study was to characterize sex differences in fatigability over a range of running distances and to examine possible differences in the postrace alteration of the cost of running (Cr).

Methods

Eighteen pairs of men and women were matched by performance after completing different races ranging from 40 to 171 km, divided into SHORT versus LONG races (<60 and >100 km, respectively). Neuromuscular function and Cr were tested before and after each race. Neuromuscular function was evaluated on both KE and PF with voluntary and evoked contractions using electrical nerve (KE and PF) and transcranial magnetic (KE) stimulation. Oxygen uptake, respiratory exchange ratio, and ventilation were measured on a treadmill and used to calculate Cr.

Results

Compared with men, women displayed a smaller decrease in maximal strength in KE (−36% vs −27%, respectively, P < 0.01), independent of race distance. In SHORT only, women displayed less peripheral fatigue in PF compared with men (Δ peak twitch: −10% vs −24%, respectively, P < 0.05). Cr increased similarly in men and women.

Conclusions

Women experience less neuromuscular fatigue than men after both “classic” and “extreme” prolonged running exercises but this does not impact the degradation of the energy Cr.
Understanding vaccine hesitancy: the evidence
Authors: While Alison
Published: June 2021

Vaccination is an important public health intervention, but its effectiveness depends upon the uptake of vaccination reaching sufficient levels to yield ‘herd’ immunity. While the majority of the UK hold positive attitudes about vaccination, some people, including health professionals, decline vaccinations. This article reviews the evidence relating to vaccine hesitancy, its underlying factors and the sociodemographic variations. A second article will review the evidence relating to strategies to address vaccine hesitancy and promote vaccination acceptance.
Velcro compression wraps as an alternative form of compression therapy for venous leg ulcers: a review
Authors: Cox Amy , Bousfield Chrissie
Published: June 2021

The first-line treatment for venous leg ulcers (VLUs) is compression therapy, most commonly, with compression bandages. A similar treatment measure is used for lymphoedema in the form of Velcro compression wraps (VCWs). However, the use of VCWs for VLUs is less evident, and a direct comparison to compression bandaging is not evident. This review explores the evidence to support the use of VCWs for the treatment of VLUs in order to raise awareness of alternative forms of compression therapy. Nine primary research studies were analysed, from which four key themes emerged: quality of life, cost of treatment, ulcer healing time and pressure maintenance. The findings suggest that VCWs decrease material costs by at least 50%, and further savings may be realised by reducing the costs associated with nursing time. The benefits of promoting self-care, maintaining compression, and eliciting greater healing rates are clearly evident, and the impact on quality of life is substantiated.
Using a novel breathable silicone adhesive (Sil2 technology) in stoma appliances to improve peristomal skin health: answering the key questions
Authors: Le Ber Fiona
Published: June 2021

Fiona Le Ber answers some of the questions that stoma care nurses may have regarding this novel silicone adhesive based technology, which helps to avoid medical adhesive related skin injury (MARSI) and moisture-associated skin damage (MASD). Whereas hydrocolloid stoma appliances absorb moisture, this has a non-absorptive method of moisture management that prevents peristomal skin becoming damp and excoriated.
The Yellowstone magmatic-hydrothermal system: using radiogenic and stable isotope geochemistry to constrain the processes of water-rock interaction
Authors: Messa Cole
Published: June 2021

The hot springs of Yellowstone National Park provide a broad range of isotopic data (e.g. 238U-, 235U-, and 232Th-series) that can be exploited to interpret the geochemical processes occurring at depth, including water-rock interaction, nuclide sourcing, and fluid residence times. Despite its worldwide notoriety, Yellowstone’s hydrothermal system remains largely unconstrained. While major advances in the past century have helped us to understand the highly varied geochemical characteristics of Yellowstone’s thermal features and their potential mechanisms of formation, many questions remain regarding where exactly the water resides before ascending to the surface, how long the water remains at depth, and what geochemical processes are occurring between these waters and the superheated aquifer rocks. One of the primary questions surrounding the Yellowstone hydrothermal system revolves around the concept of “phase separation”, whereby ascending, pressurized hydrothermal fluids undergo decompressional boiling and separate into an acidic vapor phase and a neutral fluid phase. These diverging phases result in the two dominant spring chemistries viewed on the surface, acid-sulfate springs and neutral-chloride springs. Still, little is known about the timescales such a process operates on, and what geochemical parameters can be constrained to support the existence of this model. Herein we examine a handful of hydrothermal features throughout Yellowstone National Park in an effort to investigate the likelihood of phase separation’s existence and whether or not the isotopic evidence supports the geochemical processes that we know to be occurring should this model persist within the plumbing of a continental hydrothermal system.

 

Featured photo from figure 3 in report.
Factors influencing perceived appropriateness of concessioner activity in Grand Teton
Authors: Pitas Nicholas
Published: June 2021

Concessioner provided services are integral to the national park visitor experience, and with visitation across NPS units growing steadily, services provided by these public-private-partnerships will likely only increase in importance. Despite this, concerns exist regarding the presence of for-profit entities within national parks. While private businesses may be more responsive to consumers, their presence raises questions regarding equity, access, and perceptions of ownership. The purpose of this study was to assess factors that may influence visitor’s perceptions of appropriateness regarding (a) current and (b) future concessioner activities within Grand Teton National park (GTNP). Regression analyses indicate the importance of personal values, rather than actual experiences (positive or negative) with concessions in shaping perceived appropriateness of future concessions activity. Satisfaction with concessions services, amount of concessions activity that respondents perceived in the park in the present, and trust in GTNP were all non-factors in determining anticipated future appropriateness. Instead, a belief that concessions activity would increase, social liberalism, economic conservatism, and place identity with GTNP were related to perceptions that concessioner activity at GTNP would be inappropriately high in the future. Although the regression predicting future beliefs was robust (R2 = 0.43), no variables significantly predicted current beliefs (R2 = 0.05).

 

Featured photo by Grand Teton on Flickr. https://flic.kr/p/2jf3fa9
Enhancing the flexibility and functionality of SCNs: demonstration of evolution toward any-core-access, nondirectional, and contentionless spatial channel cross-connects [Invited]
Authors: Jinno Masahiko , Ishikawa Tsubasa , Kodama Takahiro , Hasegawa Hiroshi , Subramaniam Suresh
Published: June 2021

A spatial channel network (SCN) was recently proposed toward the
forthcoming spatial division multiplexing (SDM) era, in which the
optical layer is explicitly evolved to the hierarchical SDM and
wavelength division multiplexing layers, and an optical node is
decoupled into a spatial cross-connect (SXC) and wavelength
cross-connect to achieve an ultrahigh-capacity optical network in a
highly economical manner. In this paper, we report feasibility
demonstrations of an evolution scenario regarding the SCN architecture
to enhance the flexibility and functionality of spatial channel
networking from a simple fixed-core-access and directional spatial channel ring network to a multidegree,
any-core-access, nondirectional, and core-contentionless mesh SCN. As key building blocks of
SXCs, we introduce what we believe to be novel optical devices: a

1

×

2

multicore fiber (MCF) splitter, a
core selector (CS), and a core and port selector (CPS). We construct
free-space optics-based prototypes of these devices using five-core
MCFs. Detailed performance evaluations of the prototypes in terms of
the insertion loss (IL), polarization-dependent loss (PDL), and
intercore cross talk (XT) are conducted. The results show that the
prototypes provide satisfactorily low levels of IL, PDL, and XT. We
construct a wide variety of reconfigurable spatial add/drop
multiplexers (RSADMs) and SXCs in terms of node degree, interport
cross-connection architecture, and add/drop port connectivity
flexibilities. Such RSADMs/SXCs include a fixed-core-access and
directional RSADM using a

1

×

2

MCF splitter; an any-core-access,
nondirectional SXC with core-contention using a CS; and an
any-core-access, nondirectional SXC without core-contention using a
CPS. Bit error rate performance measurements for SDM signals that
traverse the RSADMs/SXCs confirm that there is no or a very slight
optical signal-to-noise-ratio penalty from back-to-back performance.
We also experimentally show that the flexibilities in the add/drop
port of the SXCs allow us to recover from a single or concurrent
double link failure with a wide variety of options in terms of
availability and cost-effectiveness.
Locating non-line-of-sight features and recovering imagery conveyed through parallax in passive plenoptic imaging
Authors: Lin Di , Leger James R.
Published: June 2021

We present a method for recovering the perspective image of a non-line-of-sight scene based on plenoptic observations of indirect photons scattered from a flat homogeneous surface. The plenoptic information is used to ascertain locations of non-line-of-sight features in a hidden scene. This latent knowledge is then used for the partial reconstruction of the scene by extracting the imagery perceived by the non-line-of-sight features from the scattered light field measured along the surface. We demonstrate the efficacy of our technique by applying it to synthetic and measured light field data to retrieve the locations of multiple knife-edge occlusions in a test scene along with their perceived imagery.
Independently tunable triple Fano resonances based on MIM waveguide structure with a semi-ring cavity and its sensing characteristics
Authors: Liu Xing , Li Jina , Chen Jianfeng , Rohimah Siti , Tian He , Wang Jinfang
Published: June 2021

In this paper, a metal–insulator–metal (MIM) waveguide structure consisting of a side-coupled rectangular cavity (SCRC), a rightward opening semi-ring cavity (ROSRC), and a bus waveguide is reported. The finite element method is used to analyze the transmission characteristics and magnetic-field distributions of the structure in detail. The structure can support triple Fano resonances, and the Fano resonances can be tuned independently by altering the geometric parameters of the structure. Moreover, the structure can be applied in refractive index sensing and biosensing. The maximum sensitivity of refractive index sensing is up to 1550.38 nm/RIU, and there is a good linear relationship between resonance wavelength and refractive index. The MIM waveguide structure has potential applications in optical on-chip nano-sensing.
Independently programmable frequency-multiplexed phase-sensitive optical parametric amplification in the optical telecommunication band
Authors: Omi Akihito , Hosaka Aruto , Tomita Masaya , Yamagishi Yuta , Wakui Kentaro , Niimura Shintaro , Takahashi Kazuki , Takeoka Masahiro , Kannari Fumihiko
Published: June 2021

We experimentally demonstrate programmable multimode phase-sensitive amplification multiplexed in the frequency domain for flexible control of parallelly generated squeezed states. We utilize the unique phase-matching condition of a type-II periodically poled potassium titanyl phosphate (PPKTP) crystal and pulse shaping technique to fully control the frequency-domain parallel generation of squeezed states in the optical telecommunication band. We experimentally verify that the independent programmability of phase-sensitive optical parametric amplification (OPA) for the modes corresponding to different frequency bands can be achieved by shaping the pump laser pulse from optical parametric gain measurements using a coherent probe light generated by a degenerate synchronously pumped optical parametric oscillator.
Silicon subwavelength grating waveguides with high-index chalcogenide glass cladding
Authors: Jean Philippe , Douaud Alexandre , LaRochelle Sophie , Messaddeq Younès , Shi Wei
Published: June 2021

Silicon subwavelength grating waveguides enable flexible design in integrated photonics through nano-scale refractive index engineering. Here, we explore the possibility of combining silicon subwavelength gratings waveguides with a high-index chalcogenide glass as a top cladding, thus modifying the waveguiding behavior and opening a new design axis for these structures. A detailed investigation of the heterogeneous SWG waveguide with high-index cladding is presented based on analytical and numerical simulations. We design, fabricate and characterize silicon subwavelength grating waveguide microring resonators with an As20S80 cladding. Thanks to As20S80 negative thermo-optic coefficient, we achieve near athermal behavior with a measured minimum thermally induced resonance shift of −1.54 pm/K, highlighting the potential of subwavelength grating waveguides for modal confinement engineering and to control light-matter interaction. We also show that the chalcogenide glass can be thermally reflowed to remove air gaps inside the cladding, resulting in a highly conformal structure. These types of waveguides can find application in reconfigurable photonics, nonlinear optics, metamaterials or slow light.
Broadband, background-free methane absorption in the mid-infrared
Authors: Stauffer Hans U. , Grib Stephen W. , Schumaker S. Alexander , Roy Sukesh
Published: June 2021

Rotationally resolved, broadband absorption spectra of the fundamental vibrational transition of the asymmetric C–H stretch mode of methane are measured under single-laser-shot conditions using time-resolved optically gated absorption (TOGA). The TOGA approach exploits the difference in timescales between a broadband, fs-duration excitation source and the ps-duration absorption features induced by molecular absorption to allow effective suppression of the broadband background spectrum, thereby allowing for sensitive detection of multi-transition molecular spectra. This work extends the TOGA approach into the mid-infrared (mid-IR) spectral regime, allowing access to fundamental vibrational transitions while providing broadband access to multiple mid-IR transitions spanning ∼150 cm−1 (∼160 nm) near 3.3 μm, thereby highlighting the robustness of this technique beyond previously demonstrated electronic spectroscopy. Measurements are conducted in a heated gas cell to determine the accuracy of the simultaneous temperature and species-concentration measurements afforded by this single-shot approach in a well-characterized environment. Application of this approach toward fuel-rich methane–nitrogen–oxygen flames is also demonstrated.
Semiconductor-based selective emitter with a sharp cutoff for thermophotovoltaic energy conversion
Authors: Ni Qing , Ramesh Rajagopalan , Chen Cheng-An , Wang Liping
Published: June 2021

A semiconductor emitter can possibly achieve a sharp cutoff wavelength due to its intrinsic bandgap absorption and almost zero sub-bandgap emission without doping. A germanium-wafer-based selective emitter with front-side antireflection and backside metal coating is studied here for thermophotovoltaic (TPV) energy conversion. Optical simulation predicts the spectral emittance above 0.9 in the wavelengths from 1 to 1.85 µm and below 0.2 in the sub-bandgap range with a sharp cutoff around the bandgap, indicating superior spectral selectivity behavior. This is confirmed by excellent agreement with indirectly measured spectral emittance of the fabricated Ge-based selective emitter sample. Furthermore, the TPV efficiency by pairing the Ge-based selective emitter with a GaSb cell is theoretically analyzed at different temperatures. This Letter facilitates the development of the semiconductor-based selective emitters for enhancing TPV performance.
Eu3+-doped Bi2MoO6 phosphors for highly sensitive and visible H2S gas indicator material: optical and color properties, and gas sensing performance
Authors: Kang Tae Wook , Park Young Ji , Jeong Gyu Jin , Bae Byungseo , Kim Sun Woog
Published: June 2021

B
i

2

M
o
O

6

:

E
u

3
+

phosphors were synthesized by a solid state reaction, and

H

2

S

gas sensing performance was investigated. The

B
i

2

M
o
O

6

:

E
u

3
+

phosphors showed an excellent red emission due to f-f transition of

E
u

3
+

. Owing to the exposure to

H

2

S

gas, the emission intensity of the phosphors dramatically decreased to 40% of the initial value. The body color of the phosphor changed from yellow-white to dark brown. The response of the

B
i

2

M
o
O

6

:

E
u

3
+

phosphors for

H

2

S

gas was started from 10 ppm, and the emission intensity exponentially decreased with increasing the concentration until 500 ppm.
Expectancy-based rhythmic entrainment as continuous Bayesian inference
Authors: Cannon Jonathan
Published: June 2021

When presented with complex rhythmic auditory stimuli, humans are able to track underlying temporal structure (e.g., a “beat”), both covertly and with their movements. This capacity goes far beyond that of a simple entrained oscillator, drawing on contextual and enculturated timing expectations and adjusting rapidly to perturbations in event timing, phase, and tempo. Previous modeling work has described how entrainment to rhythms may be shaped by event timing expectations, but sheds little light on any underlying computational principles that could unify the phenomenon of expectation-based entrainment with other brain processes. Inspired by the predictive processing framework, we propose that the problem of rhythm tracking is naturally characterized as a problem of continuously estimating an underlying phase and tempo based on precise event times and their correspondence to timing expectations. We present two inference problems formalizing this insight: PIPPET (Phase Inference from Point Process Event Timing) and PATIPPET (Phase and Tempo Inference). Variational solutions to these inference problems resemble previous “Dynamic Attending” models of perceptual entrainment, but introduce new terms representing the dynamics of uncertainty and the influence of expectations in the absence of sensory events. These terms allow us to model multiple characteristics of covert and motor human rhythm tracking not addressed by other models, including sensitivity of error corrections to inter-event interval and perceived tempo changes induced by event omissions. We show that positing these novel influences in human entrainment yields a range of testable behavioral predictions. Guided by recent neurophysiological observations, we attempt to align the phase inference framework with a specific brain implementation. We also explore the potential of this normative framework to guide the interpretation of experimental data and serve as building blocks for even richer predictive processing and active inference models of timing.
Modeling influenza seasonality in the tropics and subtropics
Authors: Yuan Haokun , Kramer Sarah C. , Lau Eric H. Y. , Cowling Benjamin J. , Yang Wan
Published: June 2021

Climate drivers such as humidity and temperature may play a key role in influenza seasonal transmission dynamics. Such a relationship has been well defined for temperate regions. However, to date no models capable of capturing the diverse seasonal pattern in tropical and subtropical climates exist. In addition, multiple influenza viruses could cocirculate and shape epidemic dynamics. Here we construct seven mechanistic epidemic models to test the effect of two major climate drivers (humidity and temperature) and multi-strain co-circulation on influenza transmission in Hong Kong, an influenza epidemic center located in the subtropics. Based on model fit to long-term influenza surveillance data from 1998 to 2018, we found that a simple model incorporating the effect of both humidity and temperature best recreated the influenza epidemic patterns observed in Hong Kong. The model quantifies a bimodal effect of absolute humidity on influenza transmission where both low and very high humidity levels facilitate transmission quadratically; the model also quantifies the monotonic but nonlinear relationship with temperature. In addition, model results suggest that, at the population level, a shorter immunity period can approximate the co-circulation of influenza virus (sub)types. The basic reproductive number R0 estimated by the best-fit model is also consistent with laboratory influenza survival and transmission studies under various combinations of humidity and temperature levels. Overall, our study has developed a simple mechanistic model capable of quantifying the impact of climate drivers on influenza transmission in (sub)tropical regions. This model can be applied to improve influenza forecasting in the (sub)tropics in the future.
Estimating the stock size of harbor seals (Phoca vitulina richardii) in the inland waters of Washington State using line-transect methods
Authors: Jefferson Thomas A. , Smultea Mari A. , Ward Eric J. , Berejikian Barry
Published: June 2021

Harbor seals (Phoca vitulina richardii) in the inland waters of Washington were reduced by predator control programs in the twentieth century, but stocks have rebounded since being protected in the 1970s. Three management stocks are recognized, but there is little information on their current abundance. We conducted 38,431 km of aerial line-transect surveys throughout the range of these stocks in 2013–2016, sighting a total of 4,678 groups of harbor seals. Line-transect analysis with Beaufort sea state as a covariate provided estimates of the number of seals in the water. We then incorporated tagging data from 15 instrumented seals to develop correction factors, both for seals missed in the water while diving, and those that were on shore. Tagging data were modeled with generalized linear mixed models to provide estimates of the proportions diving and hauled out. After applying these correction factors, we estimated that the Hood Canal stock contained 1,368 seals (CV = 16.8%), the Southern Puget Sound stock contained 1,976 seals (CV = 20.5%), and the Washington Northern Inland Waters stock contained 7,513 seals (CV = 11.5%). This study presents a non-traditional approach to estimating the size of Washington inland waters harbor seal stocks, which may also be applicable to other species for which survey and tagging data are available.