bluuebunny/crossref_metadata_2025 huggingface dataset:
The mechanical and thermal properties of graphitic carbon nitride (g‐C3N4)‐based epoxy composites
Authors: Baghdadi Yasmine N. , Sinno Jihad , Bouhadir Kamal , Harb Mohammad , Mustapha Samir , Patra Digambara , Tehrani‐Bagha Ali R.
Published: July 2021

Numerous ways to reinforce epoxy resin and improve its thermomechanical properties have been attempted using organic and inorganic nanoparticles. In this paper, graphitic carbon nitride (g‐C3N4) nanoparticles were synthesized and used to improve the mechanical properties and thermal stability of epoxy composites. The g‐C3N4 was synthesized from cheap melamine powder using a simple one‐step thermal treatment, then was used to reinforce the resin at different weight percentages (wt%). X‐ray diffraction, scanning electron microscopy (SEM), and Fourier infrared spectroscopy were used to characterize the g‐C3N4 and ensure its successful synthesis by studying the changes in its crystal structure, morphology, and chemical structure. The filler was dispersed in the resin using a combination of ultrasonication and high shear mixing. The results showed that the mechanical properties were optimum when 0.5 wt% g‐C3N4 was used. The tensile strength and fracture toughness of the resulting epoxy composite improved by 21.8% and 77.3%, respectively. SEM was used to investigate the morphologies of cracks formed in epoxy composite specimens after the tensile testing. The SEM micrographs of the fracture surface showed a transition from a brittle to a rough morphology, signifying the enhancement in the composites' toughness. Thermogravimetric analysis showed a good improvement in degradation temperature of up to 8.86% while dynamic mechanical analysis showed that the incorporation of g‐C3N4 did not affect the material's glass transition temperature.
A Review on Experimental Identification of Active Sites in Model Bifunctional Electrocatalytic Systems for Oxygen Reduction and Evolution Reactions
Authors: Hou Shujin , Kluge Regina M. , Haid Richard W. , Gubanova Elena L. , Watzele Sebastian A. , Bandarenka Aliaksandr S. , Garlyyev Batyr
Published: July 2021

Efficient electrocatalysis of the oxygen reduction (ORR) and evolution (OER) reactions is essential in numerous renewable energy conversion systems, such as fuel cells, metal‐air batteries, and water electrolyzers. Design and optimization of electrocatalytic materials for such systems primarily rely on understanding the nature of active centers on the catalyst surface. This review focuses on several important aspects of the experimental identification of active sites on various model bifunctional ORR/OER electrocatalytic surfaces. Applications of the state‐of‐the‐art experimental techniques are analyzed. In addition, approaches to investigate and understand the influence of some supporting electrolyte components on the ORR and OER activities are discussed.
Computational fluid dynamic characterization of vertical‐wheel bioreactors used for effective scale‐up of human induced pluripotent stem cell aggregate culture
Authors: Dang Tiffany , Borys Breanna S. , Kanwar Shivek , Colter James , Worden Hannah , Blatchford Abigail , Croughan Matthew S. , Hossan Tareq , Rancourt Derrick E. , Lee Brian , Kallos Michael S. , Jung Sunghoon
Published: July 2021

Bioreactor‐based processes are the method of choice for efficient expansion of cells in a controlled setting. However, induced pluripotent stem cells (iPSCs) have proven to be extremely sensitive to the bioreactor hydrodynamic environment, making the use of suspension bioreactors to produce quality‐assured cells at clinical and commercial scales very challenging. The PBS vertical‐wheel (VW) bioreactor combines radial and axial flow components to produce uniform hydrodynamic force distributions, making it a promising platform to overcome the scale‐up challenges associated with iPSCs. In this study, hydrodynamic characterization through computational fluid dynamics modelling of VW bioreactors was performed. Analysis of these models proved that important volume average hydrodynamic variables could be maintained throughout scale‐up from the 0.1 L to the 15 L VW bioreactor scale. Each bioreactor scale (0.1, 0.5, 3, and 15 L) was modelled at a variety of agitation rates, leading to the generation of scale‐up correlation equations. These equations allow operators to define a working range of hydrodynamic variables at one scale and calculate the corresponding agitation rates at other modelled scales. A suggested operating range of agitation rates was determined for the successful culture of iPSCs in the VW bioreactor at each scale, corresponding to constant volume average energy dissipation rate. Agitation rates from the 0.1 and 0.5 L VW bioreactor scale were experimentally tested to biologically validate the suggested range. High cell‐fold expansion, healthy aggregate morphology, growth, and uniformity were demonstrated for all conditions tested within the suggested working range.
Construction of Self‐Reporting Biodegradable CO2‐Based Polycarbonates for the Visualization of Thermoresponsive Behavior with Aggregation‐Induced Emission Technology†
Authors: Wang Molin , Wang Enhao , Cao Han , Liu Shunjie , Wang Xianhong , Wang Fosong
Published: July 2021

Main observation and conclusion

Thermoresponsive polymers with simultaneous biodegradability and signal “self‐reporting” outputs that meet for advanced applications are hard to obtain. To address this issue, we developed fluorescence signal “self‐reporting” biodegradable thermoresponsive polycarbonates through the immortal copolymerization of CO2 and oligoethylene glycol monomethyl ether‐functionalized epoxides in the presence of hydroxyl‐modified tetraphenylethylene (TPE‐OH). TPE‐OH was used as chain transfer agent to afford well‐defined polycarbonates with controlled molecular weight (6000—17000 g·mol–1) and aggregation‐induced emission characteristics. Through temperature‐dependent fluorescence intensity study, low critical solution transition of TPE‐labeled polycarbonates were determined and the fine details of thermal‐induced phase transition process were monitored. Further research indicated that temperature‐controlled aggregation and dissociation of TPE moieties are the main reason for fluorescence intensity variations. We anticipate that this work could offer a method to visualize the thermal transition process of thermoresponsive polycarbonates and broaden their application fields as smart materials.
Trifunctionalization of Aryl Iodides with Two Distinct Nitrogen and Carbon Electrophiles by Palladium/Norbornene Catalysis
Authors: Wang Jing , Wang Hui , Wang Zihan , Li Linqiang , Qin Cheng , Luan Xinjun
Published: July 2021

Main observation and conclusion

Herein, we report a highly chemo‐ and regioselective vicinal trifunctionalization of aryl iodides by palladium/norbornene (Pd/NBE) catalysis. The key feature of this new method is the introduction of two distinct nitrogen and carbon electrophiles, with a large gap in reactivity, for ortho‐unsubstituted aryl iodides via an intermolecular and intramolecular C―H functionalization, respectively. Eight types of ipso terminations can be coupled with both ortho‐amination and ortho‐alkylation, affording a variety of polysubstituted benzoheterocyclic scaffolds. Silicon‐tethered substrates can lead to polyfucntional arenes via a single‐step operation. Noteworthy, these products exhibit full‐color‐tunable strong fluorescence emissions with large Stokes shifts, and product 7r can serve as a fluorescent probe to specifically target lysosome in living cells.
Health‐related quality of life among colorectal cancer survivors of diverse sexual orientations
Authors: Boehmer Ulrike , Ozonoff Al , Winter Michael , Berklein Flora , Potter Jennifer , Hartshorn Kevan L. , Ward Kevin C. , Ceballos Rachel M. , Clark Melissa A.
Published: July 2021

Background

The purpose of this study was to examine the health‐related quality of life of sexual minority survivors in comparison with heterosexual survivors.

Methods

Four hundred eighty eligible survivors participated in a telephone survey that measured survivors' outcomes, which consisted of physical and mental quality of life and self‐rated fair or poor health. These survivors were diagnosed with stage I, II, or III colorectal cancer an average of 3 years before the survey and were recruited from 4 cancer registries. Using forward selection with generalized linear models or logistic regression models, the authors considered 4 domains—personal factors, environmental factors, health condition characteristics, and body function and structure—as correlates for each survivorship outcome.

Results

The authors found that unadjusted physical quality of life and self‐rated fair/poor health were similar for all survivors. Sexual minority survivors had poorer unadjusted mental quality of life in comparison with heterosexual survivors. After adjustments for covariates, this difference was no longer statistically significant. Three domains (personal factors, health condition characteristics, and body function and structure) explained colorectal cancer survivors' fair/poor health and 46% of the variance in physical quality of life, whereas 56% of the variance in mental quality of life was explained by personal factors, body function and structure, and environmental factors.

Conclusions

This study has identified modifiable factors that can be used to improve cancer survivors' quality of life and are, therefore, relevant to ongoing efforts to improve the survivorship experience.
The impact of the social construct of race on outcomes among bacille Calmette‐Guérin‐treated patients with high‐risk non‐muscle–invasive bladder cancer in an equal‐access setting
Authors: Lawler Corinne , Gu Lin , Howard Lauren E. , Branche Brandee , Wiggins Emily , Srinivasan Aditya , Foster Meagan L. , Klaassen Zachary , De Hoedt Amanda M. , Gingrich Jeffrey R. , Theodorescu Dan , Freedland Stephen J. , Williams Stephen B.
Published: July 2021

Background

The objective of this study was to describe bladder cancer outcomes as a function of race among patients with high‐risk non–muscle‐invasive bladder cancer (NMIBC) in an equal‐access setting.

Methods

A total of 412 patients with high‐risk NMIBC who received bacille Calmette‐Guérin (BCG) from January 1, 2010, to December 31, 2015, were assessed. The authors used the Kaplan‐Meier method to estimate event‐free survival and Cox regression to determine the association between race and recurrence, progression, disease‐specific, and overall survival outcomes.

Results

A total of 372 patients who had complete data were included in the analysis; 48 (13%) and 324 (87%) were Black and White, respectively. There was no difference in age, sex, smoking status, or Charlson Comorbidity Index by race. White patients had a higher socioeconomic status with a greater percentage of patients living above the poverty level in comparison with Black patients (median, 85% vs 77%; P < .001). A total of 360 patients (97%) received adequate induction BCG, and 145 patients (39%) received adequate maintenance BCG therapy. There was no significant difference in rates of adequate induction or maintenance BCG therapy according to race. There was no significant difference in recurrence (hazard ratio [HR], 1.53; 95% confidence interval [CI], 0.64‐3.63), progression (HR, 0.77; 95% CI, 0.33‐1.82), bladder cancer–specific survival (HR, 1.01; 95% CI, 0.30‐3.46), or overall survival (HR, 0.97; 95% CI, 0.56‐1.66) according to Black race versus White race.

Conclusions

In this small study from an equal‐access setting, there was no difference in the receipt of BCG or any differences in bladder cancer outcomes according to race.
Breast health awareness campaign and screening pilot in a Kenyan County: Findings and lessons
Authors: Mwenda Valerian , Bor Joan‐Paula , Gitungo Hannah , Kirika Lydia , Njoroge Richard , Mugi Beatrice , Ojuka Daniel , Nyangasi Mary
Published: July 2021

Background and Aim

Breast cancer is the leading cancer in terms of incidence in Kenya. We conducted a breast cancer awareness and screening pilot to assess feasibility of rolling out a national screening program in Kenya.

Methods

Conducted in Nyeri County during October–November 2019, the pilot had three phases; awareness creation, screening (clinical breast examination and/or imaging) and final evaluation (post‐screening exit interviews and retrospective screening data review). Descriptive statistics on awareness, screening process and outputs were derived.

Results

During the pilot, 1813 CBE, 217 breast ultrasounds and 600 mammograms were performed. Mammography equipment utilization increased from 11% to 83%. Of 49 women with suspicious lesions on mammography, only 22 (44.9%) had been linked to care 4 months after the campaign. Of 532 exit interview respondents; 95% (505/532) were ≥35 years of age; 80% (426/532) had been reached by the awareness campaign. Majority (75% [399/532]) had received information from community health volunteers; 68% through social groups. Majority (79% [420/532]) felt the campaign had changed their behavior on breast health. Although 77% (407/532) had knowledge on self breast examination (SBE); only 13% practiced monthly SBE. More than half (58% [306/532]) had previously undertaken a CBE. Approximately 70% (375/528) were unaware of mammography before the pilot; 86% (459/532) had never previously undertaken a mammogram. Fifty‐five percent (293/532) of respondents had screening waiting times of >120 min.

Conclusion

Community health workers can create breast cancer screening demand sustainably. Adequate personnel and effective follow‐up are crucial before national roll‐out of a breast cancer screening program.
Systematic realization of low‐frequency third‐order sinusoidal oscillators
Authors: Raj Ajishek , Kumar Pragati , Bhaskar Data Ram
Published: July 2021

In this paper, a systematic realization technique for low‐frequency third‐order sinusoidal oscillators (TOSOs) with independent control of condition of oscillation (CO) and frequency of oscillation (FO), employing minimum number of resistors and grounded capacitors, has been presented. Twelve new matrices have been systematically derived. These 12 matrices lead to four distinct low‐frequency sinusoidal oscillators with independent control of CO and FO. Workability of these proposed oscillators has been validated through experimental results of low‐frequency oscillations operating at 3.03 Hz, realized with off‐the‐shelf available IC AD844 type CFOAs. The total harmonic distortion of the presented oscillators is below 0.74%, and the frequency deviations are less than 1.06%.
History of canids in Chile and impacts on prey adaptations
Authors: Silva Rochefort Benjamín , Root‐Bernstein Meredith
Published: July 2021

Artiodactyl prey species of Chile, especially guanacos (Lama guanicoe), are reported to be very susceptible to predation by pack‐hunting feral dogs. It has been previously suggested that guanacos and endemic South American deer may have evolved in the absence of pack‐hunting cursorial predators. However, the paleoecology of canid presence in southern South America and Chile is unclear. Here, we review the literature on South American and Chilean canids, their distributions, ecologies, and hunting behavior. We consider both wild and domestic canids, including Canis familiaris breeds. We establish two known antipredator defense behaviors of guanacos: predator inspection of ambush predators, for example, Puma concolor, and rushing at and kicking smaller cursorial predators, for example, Lycalopex culpaeus. We propose that since the late Pleistocene extinction of hypercarnivorous group‐hunting canids east of the Andes, there were no native species creating group‐hunting predation pressures on guanacos. Endemic deer of Chile may have never experienced group‐hunting selection pressure from native predators. Even hunting dogs (or other canids) used by indigenous groups in the far north and extreme south of Chile (and presumably the center as well) appear to have been used primarily within ambush hunting strategies. This may account for the susceptibility of guanacos and other prey species to feral dog attacks. We detail seven separate hypotheses that require further investigation in order to assess how best to respond to the threat posed by feral dogs to the conservation of native deer and camelids in Chile and other parts of South America.
Floral attraction and flower visitors of a subcanopy, tropical rainforest tree, Fontainea picrosperma
Authors: Grant Elektra L. , Wallace Helen M. , Brooks Peter R. , Burwell Chris , Reddell Paul W. , Ogbourne Steven M.
Published: July 2021

Flowering plants in tropical rainforests rely heavily on pollen vectors for successful reproduction. Research into pollination systems in tropical rainforests is dominated by canopy species, while subcanopy plant–pollinator interactions remain under‐represented. The microclimate beneath the rainforest canopy is characterized by low light levels and is markedly different from the canopy environment that receives more light energy.

We studied the floral attractants and floral visitors of a dioecious, subcanopy tree, Fontainea picrosperma (Euphorbiaceae), in the Wet Tropics bioregion of northern Queensland, Australia.

We found that wind pollination is rare and male and female flowers do not produce nectar. Female flowers are likely pollinated due to their perceptual similarity to pollen‐offering male flowers. Female flowers had the same scent profile as male flowers, and floral scent was an important floral attractant that acted to regulate pollinator behavior. The two most abundant scent compounds present in the floral bouquet were benzyl alcohol and 4‐oxoisophorone. These compounds are ubiquitous in nature and are known to attract a wide variety of insects. Both day‐time and night‐time pollinators contributed to successful pollen deposition on the stigma, and diurnal flower visitors were identified from several orders of insects including beetles, flies, predatory wasps, and thrips. Fontainea picrosperma is therefore likely to be pollinated by a diverse array of small insects.

Synthesis. Our data indicate that F. picrosperma has a generalist, entomophilous pollination syndrome. The rainforest subcanopy is a distinctive environment characterized by low light levels, low or turbulent wind speeds, and relatively high humidity. Female flowers of F. picrosperma exhibit cost‐saving strategies by not producing nectar and mimicking the smell of reward‐offering male flowers. Insects opportunistically forage on or inhabit flowers, and pollination occurs from a pool of small insects with low energy requirements that are found beneath the rainforest canopy.
Role of carryover effects in conservation of wild Pacific salmon migrating regulated rivers
Authors: Gosselin Jennifer L. , Buhle Eric R. , Van Holmes Christopher , Beer W. Nicholas , Iltis Susannah , Anderson James J.
Published: July 2021

Determining which factors are most effective for mitigative strategies in conservation management can be difficult for species with complex life cycles. Salmon (Oncorhynchusspp.) migrating through a hydroelectric power system experience conditions that can affect their survival directly within a life stage and indirectly in subsequent life stages through carryover effects. We quantified the association of covariates with survival across life stages of Chinook salmon (O. tshawytscha): juveniles migrating downstream, juveniles in the estuary, subadults in the ocean, and adults migrating upstream. We applied a hierarchical Bayesian mark–recapture model to ~400,000 wild Snake River Chinook salmon (Pacific Northwest, USA). Modeled covariates of survival included migration timing, river temperature, flow, percent of water spilled over dams, snow water equivalent, juvenile fish transportation, juvenile fish length, dam powerhouse passage, sea surface temperature, and the North Pacific Gyre Oscillation. By analyzing these covariates in a unified model, we evaluated their relationships to survival within and across life stages in a common currency. Among direct effects, the negative relationship of sea surface temperature to ocean survival had the largest marginal effect size. Carryover effects also had substantial marginal effect sizes. Ocean survival was associated positively with juvenile length and snow water equivalent and negatively with river temperature. In comparison, direct effects on juvenile and adult survival generally showed smaller marginal effect sizes. Both juvenile and adult survival were negatively associated with river temperature. Juvenile survival increased with fish length, while adult survival was positively related to flow and negatively to percent water spilled at dams. The greatest variability in survival, however, was in the ocean stage. Thus, as the ocean continues to warm and as the human population exerts more pressure on the ecosystem, carryover effects will be increasingly important for recovering salmon and other migratory species.
Climate warming threatens the persistence of a community of disturbance‐adapted native annual plants
Authors: Reed Paul B. , Bridgham Scott D. , Pfeifer‐Meister Laurel E. , DeMarche Megan L. , Johnson Bart R. , Roy Bitty A. , Bailes Graham T. , Nelson Aaron A. , Morris William F. , Doak Daniel F.
Published: July 2021

With ongoing climate change, populations are expected to exhibit shifts in demographic performance that will alter where a species can persist. This presents unique challenges for managing plant populations and may require ongoing interventions, including in situ management or introduction into new locations. However, few studies have examined how climate change may affect plant demographic performance for a suite of species, or how effective management actions could be in mitigating climate change effects. Over the course of two experiments spanning 6 yr and four sites across a latitudinal gradient in the Pacific Northwest, United States, we manipulated temperature, precipitation, and disturbance intensity, and quantified effects on the demography of eight native annual prairie species. Each year we planted seeds and monitored germination, survival, and reproduction. We found that disturbance strongly influenced demographic performance and that seven of the eight species had increasingly poor performance with warmer conditions. Across species and sites, we observed 11% recruitment (the proportion of seeds planted that survived to reproduction) following high disturbance, but just 3.9% and 2.3% under intermediate and low disturbance, respectively. Moreover, mean seed production following high disturbance was often more than tenfold greater than under intermediate and low disturbance. Importantly, most species exhibited precipitous declines in their population growth rates (λ) under warmer‐than‐ambient experimental conditions and may require more frequent disturbance intervention to sustain populations. Aristida oligantha, a C4 grass, was the only species to have λ increase with warmer conditions. These results suggest that rising temperatures may cause many native annual plant species to decline, highlighting the urgency for adaptive management practices that facilitate their restoration or introduction to newly suitable locations. Frequent and intense disturbances are critical to reduce competitors and promote native annuals’ persistence, but even such efforts may prove futile under future climate regimes.
Plant traits and soil fertility mediate productivity losses under extreme drought in C3 grasslands
Authors: Luo Wentao , Griffin‐Nolan Robert J. , Ma Wang , Liu Bo , Zuo Xiaoan , Xu Chong , Yu Qiang , Luo Yahuang , Mariotte Pierre , Smith Melinda D. , Collins Scott L. , Knapp Alan K. , Wang Zhengwen , Han Xingguo
Published: July 2021

Extreme drought decreases aboveground net primary production (ANPP) in most grasslands, but the magnitude of ANPP reductions varies especially in C3‐dominated grasslands. Because the mechanisms underlying such differential ecosystem responses to drought are not well resolved, we experimentally imposed an extreme 4‐yr drought (2015–2018) in two C3 grasslands that differed in aridity. These sites had similar annual precipitation and dominant grass species (Leymus chinensis) but different annual temperatures and thus water availability. Drought treatments differentially affected these two semiarid grasslands, with ANPP of the drier site reduced more than at the wetter site. Structural equation modeling revealed that community‐weighted means for some traits modified relationships between soil moisture and ANPP, often due to intraspecific variation. Specifically, drought reduced community mean plant height at both sites, resulting in a reduction in ANPP beyond that attributable to reduced soil moisture alone. Higher community mean leaf carbon content enhanced the negative effects of drought on ANPP at the drier site, and ANPP–soil‐moisture relationships were influenced by soil C:N ratio at the wetter site. Importantly, neither species richness nor functional dispersion were significantly correlated with ANPP at either site. Overall, as expected, soil moisture was a dominant, direct driver of ANPP response to drought, but differential sensitivity to drought in these two grasslands was also related to soil fertility and plant traits.
Rich Oxygen‐Containing Carbon Microparticles Derived from Self‐Assembled Polyimides for High‐Performance Supercapacitors
Authors: Liang Ying , Lu Yunhua , Zhang Jianhua , Chi Haijun , Dong Yan , Xiao Guoyong
Published: July 2021

Novel porous carbon microparticles derived from self‐assembled polyimides (PIs) were prepared via a facile solvothermal strategy, followed by thermally rearranged treatment and pyrolysis process. Without additional activation, the carbon microparticles exhibited large specific surface areas and abundant oxygen and nitrogen contents. Herein, the PIs microparticles derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 3,3′‐diamino‐4,4′‐dihydroxybiphenyl, are self‐assembled by nanoscale layers. Due to thermally rearranged process, the as‐prepared carbon microparticles contain a large number of micropores and mesopores, resulting in large specific surface area of 1070.7 m2 g−1. Due to the rich oxygen of 10.96%, HPI‐90‐2‐900 offers higher specific capacitance of 263.7 F g−1 when the current density is 0.5 A g−1. In addition, the specific capacitances are maintained by 67.5% when the current density is enhanced to 10 A g−1. The long‐term stability test shows that the retention rate of specific capacitance is close to 100% after 10 000 cycles of charge and discharge when the current density was 1 A g−1, indicating a good cycle life. Moreover, a light‐emitting diode is successfully lighted up by the coin cells. Therefore, a facile strategy to improve the electrochemical performance of carbon microparticles to meet the requirements of energy storage and conversion is provided.
Techno‐economic assessment and sensitivity analysis of biodiesel production intensified through hydrodynamic cavitation
Authors: Gholami Ali , Pourfayaz Fathollah , Saifoddin Amirali
Published: July 2021

Since the last two decades, hydrodynamic cavitation has been introduced as one of the most efficient approaches to intensify transesterification. However, the number of industrial biodiesel plants utilizing this process is still minimal. One primary reason is the lack of information on both its economic and environmental impacts. In this study, a simulation‐based model was developed using Aspen HYSYS V8.4 for comparing flow‐through hydrodynamic cavitation with conventional mechanical stirring in terms of total capital investment, total product cost, net present value, modified internal rate of return, materials, and energy consumption. The two plants operated 7920 hours per year and produced 100 tons of biodiesel per day from fresh sunflower oil. The results showed that total capital investment and total product cost for hydrodynamic cavitation were roughly 65% and 10% lower than those for the mechanical stirring process, respectively. While the net present value was negative for the mechanical stirring, a positive net present value and a modified internal rate of return of 25.61% were obtained in the hydrodynamic cavitation process. Performing sensitivity analysis using the Box‐Behnken design and response surface methodology revealed that net present value was most affected by the linear term of the sunflower oil price. It was also found that hydrodynamic cavitation could significantly reduce materials and energy consumption, owing to higher reactor yield and lower alcohol and catalyst consumption.
Quantifying sediment connectivity: Moving toward a holistic assessment through a mixed methods approach
Authors: Turley Mike , Hassan Marwan A. , Slaymaker Olav
Published: July 2021

The sediment connectivity concept is particularly suitable for tackling complex, multidisciplinary questions through systems thinking. However, it is unclear how to directly measure connectivity, and so proxy variables are often applied by indices to provide estimates. In this study, we critically evaluate a broad range of connectivity indices encompassing structural and functional connectivity as well as hillslope channel coupling. We then discuss their role in providing a more holistic estimation of connectivity within the Tahoma Creek Watershed, WA. Of the 14 km of channel below the glacier front, the upper 6 km (0–6 km) are coupled to the adjacent hillslopes. Coupled reaches correspond to regions with a high proportion of area contributing sediment and relatively high connectivity values, where all measures decrease in the downstream direction. A significant transition occurs near river kilometer 6. Here the valley bottom abruptly widens, deposition occurs, and the hillslopes become decoupled from the active channel. This transitional reach is also identified as a geomorphic hotspot based on the network structure. The lower 8 km of channel downstream of this reach are largely depositional and percent contributing area and connectivity values remain low, eventually reaching a minimum. Despite their limitations, we found each method to provide unique and useful information regarding connectivity. The effect of scale and event magnitude on connectivity is illustrated. We also found vegetation, topographic characteristics, and network structure to be important in high‐gradient glacio‐volcanic landscapes. The choice of an index will depend on the research objectives, data availability, and the proxy variables that best describe the variability within the defined area.
Seasonal fluxes and sediment routing in tropical catchments affected by nickel mining
Authors: Domingo Justine Perry T. , Attal Mikaël , Mudd Simon M. , Ngwenya Bryne T. , David Carlos Primo C.
Published: July 2021

An important gap in the management of land erosion in mining‐affected areas is the understanding of the entire sediment routing system and the links between sources and storage at the catchment scale. In this study, we examine sediment delivery and its seasonality in the nickel mining‐affected Santa Cruz and Pamalabawan catchments in the Philippines. We monitored discharge, suspended sediment concentrations and suspended sediment loads across 13 sub‐catchments with contrasting degrees of mining influence from June 2018 to July 2019. First, we show the importance of the size of the area that has been physically disturbed within our sub‐catchments, with as little as 10–22% of relative disturbance area being enough to generate four‐fold to eight‐fold increase in the sediment yield relative to less disturbed and pristine areas. We found that sub‐catchments with > 10% disturbance exhibit the highest sediment yields (15.5 ± 44.7 t km−2 d−1) compared with sub‐catchments with < 10% disturbance (3.6 ± 17.7 t km−2 d−1) and undisturbed catchments (2.0 ± 5.7 t km−2 d−1). We also show that sediment flushing predominantly occurs in the most disturbed sub‐catchments at the onset of the wet season. A small number of flood events transports the bulk of the sediment, with hysteresis effects being most pronounced in disturbed areas. Lastly, we show that floodplain sediment recycling exerts a key control on sediment delivery at both reach and catchment scales, with the relative contribution of floodplain sources to the sediment budget becoming dominant in the latter stages of the wet season‐ up to 89% of the total sediment export per storm event. This study highlights the importance of both degree of disturbance and sediment pathways in controlling sediment transport in mining‐disturbed areas, and that considering the entire sediment routing system including intermediate stores is crucial to optimizing existing and future measures against siltation and potential contamination of trace metals and metalloids downstream of mining areas.
Vitamin D3 alleviates cognitive impairment through regulating inflammatory stress in db/db mice
Authors: Tan Xiaomu , Gao Lifang , Cai Xiaxia , Zhang Mingyuan , Huang Dongxu , Dang Qinyu , Bao Lei
Published: July 2021

Patients with type 2 diabetes mellitus (T2DM) have a higher risk to develop cognitive impairment. Several studies reported the potential roles of vitamin D in prevention of cognitive impairment, but the mechanism remains unclear. The present study aims to investigate the protective effects of vitamin D3 on cognitive impairment in db/db mice and to explore the possible mechanism. Twelve‐week‐old male db/db mice were randomly administrated with low, medium, and high dose of vitamin D3 (LVD, MVD, and HVD groups, respectively) and equivalent volume vitamin D3 solvent (corn oil, DM group) intragastrically. Eight age‐matched db/m mice were given equivalent volume corn oil as normal group. After 16 weeks of vitamin D3 treatment, the concentrations of fasting serum glucose in three vitamin D3 groups (especially the 1,000 IU/kg·bw dose) were significantly decreased compared with DM group. Pathology revealed that the neuron damage was reduced in vitamin D3 groups. MVD intervention significantly shortened the escape latency on day 5 and extended time in the target quadrant. Mice in HVD group had significantly higher exploration time and discrimination index compared with the DM group mice. Moreover, vitamin D3 treatment has increased the phosphorylation of cAMP‐response element‐binding protein and the expression of brain‐derived neurotrophic factor and vitamin D receptor. This treatment, meanwhile, has decreased the expression of tumor necrosis factor‐α, the phosphorylation of inhibitor kappa Bα (IκBα), and nuclear factor‐κB p65 (NF‐κB p65) in the hippocampus of db/db mice. These results suggest that vitamin D3 alleviated cognitive impairment in the hippocampus of db/db mice. Down‐regulation of the NF‐κB signaling pathway‐related proteins IκBα and p65 might be one of the possible mechanisms.
Energy Market Complexities and the Need for Certainty
Authors: DeCotis Paul A.
Published: July 2021

As many of this Journal's readers are aware, the Federal Energy Regulatory Commission (FERC) is an independent agency organized within the US Department of Energy (DOE). Simply stated, FERC is responsible for regulating the interstate transmission of natural gas, petroleum, and electricity and for overseeing the establishment of just and reasonable rates for wholesale electricity sales of Independent System Operators (ISOs) and Regional Transmission Organizations (RTOs). Sounds straight forward at first blush, but there is nothing simple about FERC's role. And, FERC's importance in energy infrastructure development and market operations cannot be overstated. As the nation and many states pursue aggressive decarbonization and clean energy goals, FERC's role in energy project permitting and compliance, and wholesale market operations is critically important. FERC can provide the leadership necessary to support private sector investment in infrastructure development and in fair market valuation and pricing of assets in energy markets. Coupled with federal and state funding and policy support, a clear and decisive role by FERC could provide the certainty investors need for committing capital to clean energy and decarbonization investments.
Co‐ingestion of prescription drugs and alcohol in US adults aged 50 years or older
Authors: Schepis Ty S. , Ford Jason A. , McCabe Sean Esteban
Published: July 2021

Objective

To examine prevalence of past‐month prescription drug misuse (PDM) and alcohol co‐ingestion and its correlates in adults age 50 or older.

Methods

Data were from the 2015–2018 US National Survey on Drug Use and Health (n = 35,190). PDM‐alcohol co‐ingestion was defined as prescription opioid, tranquilizer/sedative, or stimulant misuse while “drinking alcohol or within a couple of hours of drinking.” Co‐ingestion prevalence was estimated, and logistic and negative binomial regressions examined the sociodemographic, physical health, mental health, substance use, and substance use disorder (SUD) correlates of co‐ingestion.

Results

Over 344,000 adults aged 50 years or older (0.3%) engaged in past‐month PDM‐alcohol co‐ingestion, or 27.4% of those with past‐month PDM. Past‐month co‐ingestion was linked to greater past‐month alcohol use frequency and elevated adjusted odds ratios (aORs) for all examined substance use outcomes (e.g., non‐PDM SUD aOR = 21.8; 49.7% prevalence rate). The aOR for suicidal ideation was 506% higher in those with co‐ingestion than those without past‐year PDM.

Conclusions

US adults aged 50 years or older with past‐month PDM‐alcohol co‐ingestion are at high risk for SUD and concerning mental health symptoms. Screening for mental health and substance use treatment is warranted among aging adults with signs of PDM, especially involving co‐ingestion.
Consumer inflation expectations, income changes and economic downturns
Authors: Tsiaplias Sarantis
Published: July 2021

Using a novel, nationally representative dataset containing the expectations of over 300,000 Australians, individuals are shown to form expectations in a manner inadequately explained by popular expectation mechanisms. Approximately one in five individuals form inflation expectations that are negatively related to their own‐income changes, even after accounting for their level of optimism regarding future economic conditions and their observation of economic news. These individuals are more likely to be engaged in manual labour and to be on lower income brackets. The inflation expectations of such individuals rise, even as Phillips curve predictions of inflation fall. The findings are particularly important for inflation dynamics during economic downturns when large numbers of consumers are likely to heavily increase their inflation expectations, potentially resulting in large inflation surprises.
Mechanical performance of collagen gels is dependent on purity, α1/α2 ratio, and telopeptides
Authors: Slyker Leigh , Diamantides Nicole , Kim Jongkil , Bonassar Lawrence J.
Published: July 2021

This article describes the compositional, mechanical, and structural differences between collagen gels fabricated from different sources and processing methods. Despite extensive use of collagen in the manufacturing of biomaterials and implants, there is little information as to the variation in properties based on collagen source or processing methods. As such, differences in purity and composition may affect gel structure and mechanical performance. Using mass spectrometry, we assessed protein composition of collagen from seven different sources. The mechanics and gelation kinetics of each gel were assessed through oscillatory shear rheology. Scanning electron microscopy enabled visualization of distinct differences in fiber morphology. Mechanics and gelation kinetics differed with source and processing method and were found to correlate with differences in composition. Gels fabricated from telopeptide‐containing collagens had higher storage modulus (144 vs. 54 Pa) and faster gelation (251 vs. 734 s) compared to atelocollagens, despite having lower purity (93.4 vs. 99.8%). For telopeptide‐containing collagens, as collagen purity increased, storage modulus increased and fiber diameter decreased. As α1/α2 chain ratio increased, fiber diameter increased and gelation slowed. As such, this study provides an examination of the effects of collagen processing on key quality attributes for use of collagen gels in biomedical contexts.
HIV‐1 proviral landscape characterization varies by pipeline analysis
Authors: Ferreira Fernanda A , He Qianjing , Banning Stephanie , Roberts‐Sano Olivia , Wilkins Olivia , Kuritzkes Daniel R. , Tsibris Athe
Published: July 2021

Introduction

HIV rebounds after cessation of antiretroviral therapy, representing a barrier to cure. To better understand the virus reservoir, analysis pipelines have been developed that categorize proviral sequences as intact or defective, and further determine the precise nature of the sequence defects that may be present. We investigated the effects that different analysis pipelines had on the characterization of HIV‐1 proviral sequences.

Methods

We used single genome amplification to generate near full‐length (NFL) HIV‐1 proviral DNA sequences, defined as amplicons greater than 8000 base pairs in length, isolated from peripheral blood mononuclear cells (PBMC) of treated suppressed participants with HIV‐1. Amplicons underwent direct next‐generation single genome sequencing and were analysed using four HIV‐1 proviral characterization pipelines. Sequences were characterized as intact or defective; defective sequences were assessed for the number and types of defects present. To confirm and extend our findings, 691 proviruses from the Proviral Sequence Database (PSD) were analysed and the ProSeq‐IT tool of the PSD was used to characterize both the participant and PSD proviruses.

Results and discussion

Virus sequences derived from thirteen ART‐treated virologically suppressed participants with HIV were studied. A total of 693 HIV‐1 proviral sequences were generated, 282 of which were NFL. An average of 53 sequences per participant was analysed. We found that proviruses often harbour multiple sequence defect types (mean 2.7, 95% confidence interval [CI] 2.5, 3.0); the elimination order used by each pipeline affected the percentage of proviruses allotted into each defect category. These differences varied between participants, depending on the number of defect categories present in a given provirus sequence. Pipeline‐specific differences in characterizing the HIV‐1 5′ untranslated region (5′ UTR) led to an overestimation of the number of intact NFL proviral sequences, a finding corroborated in the independent PSD analysis. A comparison of the four published pipelines to ProSeq‐IT found that ProSeq IT was more likely to characterize proviruses as intact.

Conclusions

The choice of pipeline used for HIV‐1 provirus landscape analysis may bias the classification of defective sequences. To improve the comparison of provirus characterizations across research groups, the development of a consensus elimination pipeline should be prioritized.
Uncharted waters of justice enactment—Venturing into the social complexity of doing justice in organizations
Authors: Diehl Marjo‐Riitta , Bell Chris M. , Fortin Marion , Gollwitzer Mario , Melkonian Tessa
Published: July 2021

This Special Issue on “Justice enactment ‐ research on doing justice in organizations” was developed to address questions relating to the prerequisites and conditions for and processes and outcomes of doing and enacting justice in organizations. In this editorial, we briefly introduce the collection of the seven empirical papers included in this Special Issue, thereby providing an overview of the recent progress in the field. We also identify key aspects and gaps in the literature in order to guide future efforts to move the research in the field forward and to create more just workplaces.
Too little and too much authority sharing: Differential relationships with psychological empowerment and in‐role and extra‐role performance
Authors: Richardson Hettie A. , Kluemper Donald H. , Taylor Shannon G.
Published: July 2021

Consultation and delegation are essential behaviors by which leaders share authority with employees, and they historically are expected to positively influence employees' psychological empowerment and produce desirable behaviors. This study builds on notions of “rhetorical” versus “deep” authority sharing (Biron & Bamberger, 2011, https://doi.org/10.1080/09585192.2011.540150) and the too‐much‐of‐a‐good‐thing framework (Pierce & Aguinis, 2013, https://doi.org/10.1177/0149206311410060) to challenge these conventional expectations. Despite the tendency of extant empowerment research to treat consultation and delegation as interchangeable, we propose that differences (a) in the nature and amount of authority that each devolves to employees and (b) in the scope of decisions with which they are used (i.e., job‐focused and job‐spanning) lead to differential relationships with psychological empowerment that are in turn transmitted to employee behaviors. Results from two studies indicate that the indirect (via psychological empowerment) effects of consultation and delegation on in‐role performance and extra‐role behavior can range from negative to positive to curvilinear, depending on whether employees are consulted about or delegated job‐focused or job‐spanning decisions. Highlighting the need for nuanced approaches to understanding authority sharing as part of the empowerment process, our work begins to identify both positive and negative inflection points at which authority sharing becomes either too little or too much to induce desired outcomes.
Leadership mindset and the fall of once giant family‐run textile exporting businesses
Authors: Qureshi Jawaid A. , Shaikh Abdul Manan , Seaman Claire
Published: July 2021

Pakistan's textile sector has played an important role in the country's economy and has attracted investment from local and foreign investors. The purpose of this paper is to examine the reasons behind the failure of three top, family‐owned, textile exporting businesses in Karachi. Little is known about family firms' decision‐making processes and strategy formulation in the context of emerging economies. Using qualitative techniques including phenomenology, grounded theory, and multiple case design methods, the study highlights the role of leadership and strategy in their decline. It identifies five internal factors that led these businesses to bankruptcy: “Seth” management styles and policies (an indigenous term for owners of big businesses in South Asia, particularly India, Pakistan, and Bangladesh); the firm's culture, politics, and internal conflicts; the working conditions and human resource policies; the management of financial portfolios; and operational issues related to technology, operations, and marketing. The article concludes with some observations concerning the challenges facing family‐run businesses in such settings.