bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo evidence for the unique kinetics of evoked dopamine release in the patch and matrix compartments of the striatum
Authors: Jaquins-Gerstl Andrea , Nesbitt Kathryn M. , Michael Adrian C.
Published: April 2021

The neurochemical transmitter dopamine (DA) is implicated in a number of diseases states, including Parkinson’s disease, schizophrenia, and drug abuse. DA terminal fields in the dorsal striatum and core region of the nucleus accumbens in the rat brain are organized as heterogeneous domains exhibiting fast and slow kinetic of DA release. The rates of dopamine release are significantly and substantially faster in the fast domains relative to the slow domains. The striatum is composed of a mosaic of spatial compartments known as the striosomes (patches) and the matrix. Extensive literature exists on the spatial organization of the patch and matrix compartments and their functions. However, little is known about these compartments as they relate to fast and slow kinetic DA domains observed by fast scan cyclic voltammetry (FSCV). Thus, we combined high spatial resolution of FSCV with detailed immunohistochemical analysis of these architectural compartments (patch and matrix) using fluorescence microscopy. Our findings demonstrated a direct correlation between patch compartments with fast domain DA kinetics and matrix compartments to slow domain DA kinetics. We also investigated the kinetic domains in two very distinct sub-regions in the striatum, the lateral dorsal striatum (LDS) and the medial dorsal striatum (MDS). The lateral dorsal striatum as opposed to the medial dorsal striatum is mainly governed by fast kinetic DA domains. These finding are highly relevant as they may hold key promise in unraveling the fast and slow kinetic DA domains and their physiological significance.

Graphical abstract
Influence of different leavening agents on technological and nutritional characteristics of whole grain breads obtained from ancient and modern flour varieties
Authors: Venturi Manuel , Galli Viola , Pini Niccolò , Guerrini Simona , Sodi Costanza , Granchi Lisa
Published: April 2021

The aim of the work was to assess the influence of the leavening agent on several technological, chemical, and nutritional characteristics of breads prepared with whole soft wheat (Triticum aestivum L.) flours. As leavening agents in bread-making, baker’s yeast, biga, and sourdough were utilized. Two ancient varieties, Andriolo and Verna, and a modern grain variety, Bologna, were used. Analysis of the obtained breads included the measurement of the phenols content, the antioxidant activity, the in vitro protein and total digestibility, the texture profile, the crumb grain characteristics and the microbial shelf-life test. The results of the principle component analysis of bread features indicated a clustering depending especially on the leavening agent rather than on the employed flour, particularly when sourdough was used. Protein digestibility, crumb grain characteristics, and shelf-life led to the main differences among the samples. Ancient wheat flour displayed similar features when the same leavening agent was applied. Particularly, the use of sourdough levelled the differences due to flour, leading to breads with similar technological and nutritional characteristics. The findings highlighted a marked effect of the leavening agent on bread final characteristics.
A multisite analysis of the concordance between visual image interpretation and quantitative analysis of [18F]flutemetamol amyloid PET images
Authors: Bucci Marco , Savitcheva Irina , Farrar Gill , Salvadó Gemma , Collij Lyduine , Doré Vincent , Gispert Juan Domingo , Gunn Roger , Hanseeuw Bernard , Hansson Oskar , Shekari Mahnaz , Lhommel Renaud , Molinuevo José Luis , Rowe Christopher , Sur Cyrille , Whittington Alex , Buckley Christopher , Nordberg Agneta
Published: April 2021

Background

[18F]flutemetamol PET scanning provides information on brain amyloid load and has been approved for routine clinical use based upon visual interpretation as either negative (equating to none or sparse amyloid plaques) or amyloid positive (equating to moderate or frequent plaques). Quantitation is however fundamental to the practice of nuclear medicine and hence can be used to supplement amyloid reading methodology especially in unclear cases.

Methods

A total of 2770 [18F]flutemetamol images were collected from 3 clinical studies and 6 research cohorts with available visual reading of [18F]flutemetamol and quantitative analysis of images. These were assessed further to examine both the discordance and concordance between visual and quantitative imaging primarily using thresholds robustly established using pathology as the standard of truth. Scans covered a wide range of cases (i.e. from cognitively unimpaired subjects to patients attending the memory clinics). Methods of quantifying amyloid ranged from using CE/510K cleared marked software (e.g. CortexID, Brass), to other research-based methods (e.g. PMOD, CapAIBL). Additionally, the clinical follow-up of two types of discordance between visual and quantitation (V+Q- and V-Q+) was examined with competing risk regression analysis to assess possible differences in prediction for progression to Alzheimer’s disease (AD) and other diagnoses (OD).

Results

Weighted mean concordance between visual and quantitation using the autopsy-derived threshold was 94% using pons as the reference region. Concordance from a sensitivity analysis which assessed the maximum agreement for each cohort using a range of cut-off values was also estimated at approximately 96% (weighted mean). Agreement was generally higher in clinical cases compared to research cases. V-Q+ discordant cases were 11% more likely to progress to AD than V+Q- for the SUVr with pons as reference region.

Conclusions

Quantitation of amyloid PET shows a high agreement vs binary visual reading and also allows for a continuous measure that, in conjunction with possible discordant analysis, could be used in the future to identify possible earlier pathological deposition as well as monitor disease progression and treatment effectiveness.
Experimental investigation of equivalence ratio fluctuations in a lean premixed kerosene combustor
Authors: Vogel Manuel , Bachfischer Michael , Kaufmann Jan , Sattelmayer Thomas
Published: April 2021

In this study a measurement technique for determination of equivalence ratio fluctuations from flame chemiluminescence in a kerosene-fuelled lean premixed combustor under atmospheric conditions is presented. Firstly, fundamental investigations into the relationship between the ratio of different chemiluminescence signals and the equivalence ratio are carried out using an imaging spectrometer. The chemiluminescence intensity is recorded for a wide range of equivalence ratios and fuel mass flows during steady state operation. The spectra show that the CH*/OH* ratio depends linearly on the equivalence ratio and is independent of the mass flow in the investigated range. Moreover, the background radiation has no influence on the monotonous trend of the CH*/OH* ratio for kerosene combustion. This interesting finding opens up new possibilities for passive optical measurement of the equivalence ratio in kerosene flames. Bandpass-filtered phase-correlated images of OH* and CH* chemiluminescence of an acoustically excited flame are taken simultaneously on one camera chip using an image doubler. After distortion correction, the image pair is used to calculate the global equivalence ratio from the CH*/OH* ratio. Based on the calibration chart derived in stationary operation, phase-resolved equivalence ratio perturbations are determined during acoustic excitation. The presented technique allows a quantitative measurement of equivalence ratio fluctuations in spray combustion and can therefore provide a better understanding of the fundamental mechanisms of thermoacoustic instabilities triggered by equivalence ratio fluctuations.

Graphic abstract
Higher mortality of the less suitable brown trout host compared to the principal Atlantic salmon host when infested with freshwater pearl mussel (Margaritifera margaritifera) glochidia
Authors: Marwaha Janhavi , Jakobsen Per Johan , Karlsson Sten , Larsen Bjørn Mejdell , Wacker Sebastian
Published: April 2021

The freshwater pearl mussel (Margaritifera margaritifera) is a highly host-specific parasite, with an obligate parasitic stage on salmonid fish. Atlantic salmon (Salmo salar) and brown trout (Salmo trutta f. truttaandSalmo trutta f. fario) are the only hosts in their European distribution. SomeM. margaritiferapopulations exclusively infest either Atlantic salmon or brown trout, while others infest both hosts with one salmonid species typically being the principal host and the other a less suitable host. Glochidial abundance, prevalence and growth are often used as parameters to measure host suitability, with the most suitable host species displaying the highest parameters. However, it is not known if the degree of host specialisation will negatively influence host fitness (virulence) among different host species. In this study we examined the hypothesis that glochidial infestation would result in differential virulence in two salmonid host species and that lower virulence would be observed on the most suitable host. Atlantic salmon and brown trout were infested with glochidia from twoM. margaritiferapopulations that use Atlantic salmon as their principal host, and the difference in host mortality among infested and control (sham infested) fish was examined. Higher mortality was observed in infested brown trout (the less suitable host) groups, compared to the other test groups. Genetic assignment was used to identify offspring from individual mother mussels. We found that glochidia from individual mothers can infest both the salmonid hosts; however, some mothers displayed a bias towards either salmon or trout. We believe that the differences in host-dependent virulence and the host bias displayed by individual mothers were a result of genotype × genotype interactions between the glochidia and their hosts, indicating that there is an underlying genetic component for this parasite-host interaction.
Experience with 10 years of a robotic surgery program at an Academic Medical Center
Authors: Stringfield Sarah B. , Parry Lisa A. , Eisenstein Samuel G. , Horgan Santiago N. , Kane Christopher J. , Ramamoorthy Sonia L.
Published: April 2021

Background

Few studies have examined robotic surgery from a programmatic standpoint, yet this is how hospitals evaluate return on investment clinically and fiscally. This study examines the 10-year experience of a robotic program at a single academic institution.

Study design

All robotic operations performed at our institution from August 2005 to December 2016 were reviewed. Data were collected from the robotic system and hospital databases.

Results

A total of 3485 robotic operations were performed. Yearly case volume nearly quadrupled. There have been 37 robotic-trained surgeons in 5 specialties performing 53 different operations. Rate of conversion to open was 4.2%. American Society of Anesthesiologists (ASA) class increased over time, with ASA class 3 increasing from 20% of patients to 45% of patients.

Average case time in 2005 was 453 min, but decreased by 46% to 246 min by 2007, then remained relatively stable (range 226–247). Operating efficiency improved, with room time and case time decreasing by 9% in the past 4 years.

Average cost for robotic supplies was $1519 per case. Additional costs per case related to equipment and contracts totaled an average of $11,822.

Average length of stay (LOS) for robotic cases was 3.3 days, compared to 3.0 days for laparoscopic and 7.0 for open. Cost per day for admission after robotic surgery was 1.7 times greater than the cost of open or laparoscopic surgery. Total admission costs of robotic operations were 1.5 times those of laparoscopic surgery, but less than open operations. Readmissions following robotic cases were lower than open (15% v 26%, p < 0.0001).

Conclusions

Over 10 years, the use of robotic technology has grown significantly at our institution, with good fiscal and clinical outcomes. Operating room costs are high; however, efficiency has improved, LOS is shorter, admission costs are lower than open operations, and readmission rates are lower.
Reduction in postoperative complications by robotic surgery: a case–control study of robotic versus conventional laparoscopic surgery for gastric cancer
Authors: Kinoshita Takahiro , Sato Reo , Akimoto Eigo , Tanaka Yuya , Okayama Takafumi , Habu Takumi
Published: April 2021

Background

Robotic gastrectomy (RG) is being increasingly performed globally; it is considered an evolved type of conventional laparoscopic surgery with excellent dexterity and precision, but higher costs and longer operation time. Thus, there is a need to identify the benefits from RG and its specific candidates.

Methods

This retrospective study analyzed data from a prospectively collected clinical database at our center. Data of patients with primary gastric cancer undergoing either robotic or laparoscopic radical gastrectomy from June 2014 to June 2020 were reviewed. Surgical outcomes were compared between the two groups, and multivariable analyses were performed to elucidate the relevant factors for postoperative complications in several subgroups.

Results

A total of 1172 patients were divided into those who underwent RG (n = 152) and those who underwent laparoscopic gastrectomy (LG) (n = 1020). Baseline characteristics were similar in the two groups, except the RG group included more patients undergoing total/proximal gastrectomy (TG/PG) and patients at clinical stage III. Compared with the LG group, the RG group had lower incidences of postoperative complications ≥ Clavien-Dindo grade III (2/152 (1.3%) versus 72/1020 (7.1%); P = 0.004), and intraabdominal complications ≥ grade II (6/152 (3.9%) versus 119/1020 (11.7%); P = 0.004). Multivariable analysis revealed that RG was a significant relevant factor for reducing overall postoperative complications (≥ grade III) (odds ratio (OR) 0.16, P = 0.013), and intraabdominal complications (≥ grade II) (OR 0.29, P = 0.002). Subgroup analyses demonstrated that this tendency was enhanced in patients undergoing TG/PG (OR 0.29, P = 0.021) or at clinical stage II/III (OR 0.10, P = 0.027).

Conclusions

RG reduces the incidence of postoperative complications compared with conventional LG and this tendency may be enhanced in technically complicated procedures with demanding anastomosis or D2 lymphadenectomy. Patients requiring such procedures would most benefit from RG.
Advancing synthesis of decision tree-based multiple classifier systems: an approximate computing case study
Authors: Barbareschi Mario , Barone Salvatore , Mazzocca Nicola
Published: April 2021

So far, multiple classifier systems have been increasingly designed to take advantage of hardware features, such as high parallelism and computational power. Indeed, compared to software implementations, hardware accelerators guarantee higher throughput and lower latency. Although the combination of multiple classifiers leads to high classification accuracy, the required area overhead makes the design of a hardware accelerator unfeasible, hindering the adoption of commercial configurable devices. For this reason, in this paper, we exploit approximate computing design paradigm to trade hardware area overhead off for classification accuracy. In particular, starting from trained DT models and employing precision-scaling technique, we explore approximate decision tree variants by means of multiple objective optimization problem, demonstrating a significant performance improvement targeting field-programmable gate array devices.
Infection of susceptible/tolerant barley genotypes with Barley yellow dwarf virus alters the host plant preference of Rhopalosiphum padi clones depending upon their ability to transmit BYDV
Authors: Kern Maria , Meiners Torsten , Schliephake Edgar , Habekuss Antje , Ordon Frank , Will Torsten
Published: April 2021

Discovering mechanisms of plant–virus–vector interactions is fundamental to understand their ecology and evolution and to apply this knowledge in plant protection. To study the influence of varying Barley yellow dwarf virus (BYDV) transmission efficiencies on host plant preference of Rhopalosiphum padi (L.) clones, we performed host choice experiments with two barley cultivars (BYDV susceptible cv. ‘Rubina’ and BYDV tolerant cv. ‘Vixen’) including healthy and virus-infected plants. For the susceptible barley cultivar ‘Rubina’, aphid clone R07 (high transmission efficiency) preferred BYDV-infected over healthy host plants after 24 h, while clones D10 (medium transmission efficiency) and R09 (low transmission efficiency) preferred neither host. In contrast, BYDV infection of ‘Vixen’ did not affect the plant’s appeal for aphid clone R07. Host plant access, indicated by ingestion and observed by electrical penetration graph technique for a period of 2 h, was facilitated on BYDV-infected cv. ‘Rubina’ for the clones R07 and D10, whereas an opposite effect was observed for the clone R09. For R07 and R09, the difference was not visible after a period of 5 h. As observed earlier for BYDV-infected wheat, enhanced emission of volatile organic compounds associated with virus-induced attraction was detected for BYDV-infected cv. ‘Rubina.’ It is concluded that host plant preference is possibly linked with a high BYDV transmission efficiency as observed for the clone R07, leading to a fitness advantage of this clone as indicated by early increased ingestion. This advantage is not present on BYDV-tolerant genotypes most likely due to the absence of infection symptoms.
Habitat use by post-fledging white-tailed eagles shows avoidance of human infrastructure and agricultural areas
Authors: Balotari-Chiebao Fabio , Brommer Jon E. , Tikkanen Hannu , Laaksonen Toni
Published: April 2021

Habitat use studies provide invaluable information for the conservation of species that suffer from habitat loss or degradation. We used satellite telemetry to study the habitat use of white-tailed eagles (Haliaeetus albicilla) in relation to six habitat classes (artificial surfaces, agricultural areas, forests, semi-natural areas, wetlands and waterbodies) and five forest age classes (0–9, 10–19, 20–59, 60–99 and ≥ 100 years old) during the post-fledging period in Finland. The post-fledging period, defined here as the period between fledging and dispersal from the natal area, is a critical life-history stage. Our primary objective was to provide information that could be integrated into landscape planning, including wind-energy development (which poses a threat to white-tailed eagles). We found that the habitat classes that were selected by the young white-tailed eagles were forests, semi-natural areas (i.e., transitional woodland and bare rock) and wetlands. When using forests, the eagles selected stands of 0–9 years old, presumably due to the use of retention trees surrounded by a clear-cut as perching sites. Conversely, the habitat classes that were avoided were artificial surfaces, agricultural areas and (the immediate vicinity of) waterbodies. We conclude that the conversion of natural habitats into built and agricultural areas is detrimental to young white-tailed eagles because it reduces habitat availability. They, however, appear to be capable of using forests recently impacted by forestry if perch trees are present. Careful landscape planning is needed to protect priority habitats and avoid conflicts with an expanding white-tailed eagle population (e.g., by building wind farms in areas already environmentally disturbed).
Eradication of the mongoose is crucial for the conservation of three endemic bird species in Yambaru, Okinawa Island, Japan
Authors: Yagihashi Tsutomu , Seki Shin-Ichi , Nakaya Tomoki , Nakata Katsushi , Kotaka Nobuhiko
Published: April 2021

Okinawa Island, Japan, is a globally important biodiversity hotspot. Three endemic bird species, Okinawa rail (Hypotaenidia okinawae), Okinawa woodpecker (Dendrocopos noguchii), and Okinawa robin (Larvivora namiyei), are found only in the Yambaru region of the northern part of Okinawa Island. In order to conserve endemic species, it is important to determine the effect of alien species on endemic species. We conducted playback surveys four times every three years from 2007 to 2016 to evaluate the recent distribution of these three forest-dwelling bird species during the breeding season. Then, the association between the numbers of detections of these three species with the invasive mongoose density and the hardwood forest area was evaluated with a generalized additive mixed model (GAMM). The results showed that the distribution areas of these bird species have been recovering since the 2007 within the small Indian mongoose (Urva auropunctata) controlled area. The GAMM results showed that these bird species were abundant in areas with fewer small Indian mongooses and larger areas of hardwood forests. Thus, the mongoose had a negative impact not only on the flightless rails but also on the woodpeckers and the robins. In recent years, most of the old-growth forests have been designated as protected forests, and large-scale logging is no longer taking place in Yambaru. Eradication of the mongoose is particularly important for the conservation of these three endemic bird species.
Making Sense of Stigmatized Organizations: Labelling Contests and Power Dynamics in Social Evaluation Processes
Authors: Kvåle Gro , Murdoch Zuzana
Published: April 2021

How do social audiences negotiate and handle stigmatized organizations? What role do their heterogenous values, norms and power play in this process? Addressing these questions is important from a business ethics perspective to improve our understanding of the ethical standards against which organizations are judged as well as the involved prosecutorial incentives. Moreover, it illuminates ethical concerns about when and how (the exploitation of) power imbalances may induce inequity in the burdens imposed by such social evaluations. We address these questions building on two event-based case studies involving Hells Angels Motorcycle Club Norway, and contribute to organizational stigma theory in three ways. First, social evaluations of a stigmatized organization by multiple audiences are found to interact, collide and combine in a labelling contest. Second, we show that labels employed in this contest are pushed to either negative extremes (‘moral panic’) or positive extremes (‘moral patronage’). Finally, we show when and how power represents a double-edged sword in social evaluation processes, which can be wielded either to the benefit or to the detriment of the actors under evaluation.
Emotional Regulation in Mothers and Fathers and Relations to Aggression in Hong Kong Preschool Children
Authors: Lau Eva Yi Hung , Williams Kate
Published: April 2021

This study explored the associations among emotional regulation in mothers and fathers and preschool children’s physical and relational aggression using a Hong Kong Chinese sample. This study also explored whether child gender would moderate the association between parental emotional regulation strategies and children’s physical and relational aggression. Participants were 168 children aged 4–6 years. Parents reported on their own emotional regulation approaches and kindergarten class teachers rated children’s aggression 6 months later. Path analyses showed that higher levels of reappraisal and lower levels of suppression by mothers was associated with higher levels of child relational aggression. There were no significant associations among fathers’ emotional regulation and children’s aggression. Results from multi-group analysis showed that there were no significant moderation of the associations by child gender. Results highlight the importance of mothers’ emotional regulation in child aggression and suggest that the maladaptive consequences of emotional suppression are culturally relative.
Why Don’t Japanese Early Childhood Educators Intervene in Children’s Physical Fights? Some Characteristics of the Mimamoru Approach
Authors: Nakatsubo Fuminori , Ueda Harutomo , Kayama Misa
Published: April 2021

This study aims to examine pedagogical meanings of the Mimamoru approach frequently used by Japanese early childhood educators in children’s physical fights. Mimamoru is a strategy in which educators intentionally withhold an intervention, while carefully observing children, to foster children’s voluntary participation in their own learning, socially and cognitively. In this report, we examine why Japanese educators tend not to intervene, and how they determine whether their intervention is necessary. Using methods from Tobin’s video cued multi-vocal ethnography, we conducted focus groups at 9 early childhood education and care facilities (7 in Japan and 2 in the U.S.) with a total of 34 Japanese and 12 U.S. educators. They watched a short video clip in which a mid-career male teacher, one of the Japanese participants, used the Mimamoru approach with two children involved in a physical fight. Educators, then, discussed their interpretations of the teacher’s responses to children. The analyses of the participants’ discussion suggest that educators’ non-intervention, an important feature of the Mimamoru approach, provides children with opportunities to autonomously learn interpersonal skills, for example, through the experiences of feeling guilty and solving problems by themselves. Yet educators do intervene when they determine that the risk of physical harm caused by fighting is greater than the benefit for children to learn. Implications of the Mimamoru approach, including in other cultural contexts, are discussed.
Analysis and Exploitation of Landforms for Improved Optimisation of Camera-Based Wildfire Detection Systems
Authors: Heyns Andries M. , du Plessis Warren , Curtin Kevin M. , Kosch Michael , Hough Gavin
Published: April 2021

Tower-mounted camera-based wildfire detection systems provide an effective means of early forest fire detection. Historically, tower sites have been identified by foresters and locals with intimate knowledge of the terrain and without the aid of computational optimisation tools. When moving into vast new territories and without the aid of local knowledge, this process becomes cumbersome and daunting. In such instances, the optimisation of final site layouts may be streamlined if a suitable strategy is employed to limit the candidate sites to landforms which offer superior system visibility. A framework for the exploitation of landforms for these purposes is proposed. The landform classifications at 165 existing tower sites from wildfire detection systems in South Africa, Canada and the USA are analysed using the geomorphon technique, and it is noted that towers are located at or near certain landform types. A metaheuristic and integer linear programming approach is then employed to search for optimal tower sites in a large area currently monitored by the ForestWatch wildfire detection system, and these sites are then classified according to landforms. The results support the observations made for the existing towers in terms of noteworthy landforms, and the optimisation process is repeated by limiting the candidate sites to selected landforms. This leads to solutions with improved system coverage, achieved within reduced computation times. The presented framework may be replicated for use in similar applications, such as site-selection for military equipment, cellular transmitters, and weather radar.
Structure-based identification of SARS-CoV-2 main protease inhibitors from anti-viral specific chemical libraries: an exhaustive computational screening approach
Authors: Bhowmick Shovonlal , Saha Achintya , Osman Sameh Mohamed , Alasmary Fatmah Ali , Almutairi Tahani Mazyad , Islam Md Ataul
Published: April 2021

Worldwide coronavirus disease 2019 (COVID-19) outbreak is still threatening global health since its outbreak first reported in the late 2019. The causative novel virus has been designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although COVID-19 emergent with significant mortality, there is no availability of definite treatment measures. It is now extremely desirable to identify potential chemical entities against SARS-CoV-2 for the treatment of COVID-19. In the present study, a state-of-art virtual screening protocol was implemented on three anti-viral specific chemical libraries against SARS-CoV-2 main protease (Mpro). Particularly, viewing the large-scale biological role of Mpro in the viral replication process it has been considered as a prospective anti-viral drug target. Herein, on collected 79,892 compounds, hierarchical multistep docking followed by relative binding free energy estimation has been performed. Thereafter, implying a user-defined XP-dock and MM-GBSA cut-off scores as −8.00 and −45.00 kcal/mol, chemical space has been further reduced. Exhaustive molecular binding interactions analyses and various pharmacokinetics profiles assessment suggested four compounds (ChemDiv_D658-0159, ChemDiv_F431-0433, Enamine_Z3019991843 and Asinex_LAS_51389260) as potent inhibitors/modulators of SARS-CoV-2 Mpro. In-depth protein–ligand interactions stability in the dynamic state has been evaluated by 100 ns molecular dynamics (MD) simulation studies along with MM-GBSA-based binding free energy estimations of entire simulation trajectories that have revealed strong binding affinity of all identified compounds towards Mpro. Hence, all four identified compounds might be considered as promising candidates for future drug development specifically targeting the SARS-CoV-2 Mpro; however, they also need experimental assessment for a better understanding of molecular interaction mechanisms.

Graphic abstract
Hybrid quasi-3D optimization of grid architecture for single junction photovoltaic converters
Authors: Nikander Veikka , Wei Jianguo , Aho Arto , Polojarvi Ville , Tukiainen Antti , Guina Mircea
Published: April 2021

A numerical study of metal front contacts grid spacing for photovoltaic (PV) converter of relatively small area is presented. The model is constructed based on Solcore, an open-source Python-based library. A three-step-process is developed to create a hybrid quasi-3D model. The grid spacing under various operating conditions was assessed for two similar p–n and n–p structures. The key target was finding optimal configuration to achieve the highest conversion efficiency at different temperatures and illumination profiles. The results show that the n–p structure yields wider optimal spacing range and the highest output power. Also, it was found that temperature increase and illumination nonuniformity results in narrower optimal spacing for both structure architectures. Analyzing the current–voltage characteristics, reveals that resistive losses are the dominant loss mechanism bringing restriction in terms of ability to handle nonuniform illumination.
Pass-and-swap queues
Authors: Comte Céline , Dorsman Jan-Pieter
Published: April 2021

Order-independent (OI) queues, introduced by Berezner et al. (Queueing Syst 19(4):345–359, 1995), expanded the family of multi-class queues that are known to have a product-form stationary distribution by allowing for intricate class-dependent service rates. This paper further broadens this family by introducing pass-and-swap (P&S) queues, an extension of OI queues where, upon a service completion, the customer that completes service is not necessarily the one that leaves the system. More precisely, we supplement the OI queue model with an undirected graph on the customer classes, which we call a swapping graph, such that there is an edge between two classes if customers of these classes can be swapped with one another. When a customer completes service, it passes over customers in the remainder of the queue until it finds a customer it can swap positions with, that is, a customer whose class is a neighbor in the graph. In its turn, the customer that is ejected from its position takes the position of the next customer it can be swapped with, and so on. This is repeated until a customer can no longer find another customer to be swapped with; this customer is the one that leaves the queue. After proving that P&S queues have a product-form stationary distribution, we derive a necessary and sufficient stability condition for (open networks of) P&S queues that also applies to OI queues. We then study irreducibility properties of closed networks of P&S queues and derive the corresponding product-form stationary distribution. Lastly, we demonstrate that closed networks of P&S queues can be applied to describe the dynamics of new and existing load-distribution and scheduling protocols in clusters of machines in which jobs have assignment constraints.
Health-related quality of life of a conflict-affected population in Colombia
Authors: Yang Fan , Leon-Giraldo Sebastian , Moreno-Serra Rodrigo
Published: April 2021

Purpose

We assessed the validity of the EQ-5D instrument; explored correlations between area of residence’s conflict intensity and individual health-related quality of life (HRQoL); and identified factors associated with HRQoL in a conflict-affected population in Colombia.

Methods

We conducted a household survey among residents of the Meta province, collecting longitudinal information about HRQoL (EQ-5D-3L instrument), health, demographic and socio-economic indicators, for years 2014 (pre-2016 peace accord), 2018 (post-peace accord) and 2019 (follow-up). After examining EQ-5D’s validity, we analysed panel data using multivariate random effects models to explore associations between area conflict levels (and other factors) and HRQoL. We scrutinised these results further through multivariate linear regressions using cross-sectional data, and provided preliminary estimates of quality-adjusted life years (QALYs) gained since the Colombian peace accord.

Results

In total, 1309 individuals provided information for years 2014 and 2018; 1106 individuals were followed-up in 2019. Mean EQ-5D scores in 2014, 2018 and 2019 were 0.898, 0.846 and 0.902, respectively. The tests confirmed the validity of EQ-5D. Our estimations indicated a dose–response relationship between conflict levels and HRQoL: people in lightly and heavily affected areas had 0.019 and 0.037 lower EQ-5D scores (respectively) than people in non-affected areas. Other relevant factors included age, marital status, education, assets and health status. We estimated QALY gain of 0.0343 per individual and 20,752 for all Meta adults since the peace accord.

Conclusion

We found EQ-5D to be a valid instrument for HRQoL measurement in a conflict-affected population. Area conflict intensity was negatively associated with individual HRQoL.
Traffic collision avoidance system: false injection viability
Authors: Hannah John , Mills Robert , Dill Richard , Hodson Douglas
Published: April 2021

Safety is a simple concept but an abstract task, specifically with aircraft. One critical safety system, the Traffic Collision Avoidance System II (TCAS), protects against mid-air collisions by predicting the course of other aircraft, determining the possibility of collision, and issuing a resolution advisory for avoidance. Previous research to identify vulnerabilities associated with TCAS’s communication processes discovered that a false injection attack presents the most comprehensive risk to veritable trust in TCAS, allowing for a mid-air collision. This research explores the viability of successfully executing a false injection attack against a target aircraft, triggering a resolution advisory. Monetary constraints precluded access to a physical TCAS unit; instead, this research creates a novel program, TCAS-False Injection Environment (TCAS-FIE), that incorporates real-world distributed computing systems to simulate a ground-based attacker scenario which explores how a false injection attack could target an operational aircraft. TCAS-FIEs’ simulation models are defined by parameters to execute tests that mimic real-world TCAS units during Mode S message processing. TCAS-FIE simulations execute tests over applicable ranges (5–30 miles), altitudes (25–45K ft), and bearings standard for real-world TCAS tracking. The comprehensive tests compare altitude, measure range closure rate, and measure signal strength from another aircraft to determine the delta in bearings over time. In the attack scenario, the ground-based adversary falsely injects a spoofed aircraft with characteristics matching a Boeing 737-800 aircraft, targeting an operational Boeing 737-800 aircraft. TCAS-FIE completes 555,000 simulations using the various ranges, altitudes, and bearings. The simulated success rate to trigger a resolution advisory is 32.63%, representing 181,099 successful resolution advisory triggers out of 555,000 total simulations. The results from additional analysis determine the required ranges, altitudes, and bearing parameters to trigger future resolution advisories, yielding a predictive threat map for aircraft false injection attacks. The resulting map provides situational awareness to pilots in the event of a real-world TCAS anomaly.
The untapped potential of scenic routes for geotourism: case studies of Lasocki Grzbiet and Pasmo Lesistej (Western and Central Sudeten Mountains, SW Poland)
Authors: Chylińska Dagmara , Kołodziejczyk Krzysztof
Published: April 2021

A view is often more than just a piece of landscape, framed by the gaze and evoking emotion. Without diminishing these obvious ‘tourism-important’ advantages of a view, it is noteworthy that in itself it might play the role of an interpretative tool, especially for large-scale phenomena, the knowledge and understanding of which is the goal of geotourism. In this paper, we analyze the importance of scenic drives and trails for tourism, particularly geotourism, focusing on their ability to create conditions for experiencing the dynamically changing landscapes in which lies knowledge of the natural processes shaping the Earth’s surface and the methods and degree of its resource exploitation. The issues are found in both wider and local contexts. A more detailed insight has been conducted on the basis of two, although in some sense peripheral, tourism regions from the Sudeten Mountains (southwestern Poland): Lasocki Grzbiet (a ridge) and Pasmo Lesistej (a small range). The subjects of the investigation were complex: the geotourism potential of selected viewpoints located on the most scenic routes (mostly paths and forest tracks) as well as the problems of maintenance, conservation, and protection of their educational value. Our work is based on desk and field research supported by results of GIS visibility analyses (conducted in the QGIS program).
Biphasic range expansions with short- and long-distance dispersal
Authors: Liu Benjamin R.
Published: April 2021

Long-distance dispersal (LDD) has long been recognized as a key factor in determining rates of spread in biological invasions. Two approaches for incorporating LDD in mathematical models of spread are mixed dispersal and heavy-tailed dispersal. In this paper, I analyze integrodifference equation (IDE) models with mixed-dispersal kernels and fat-tailed (a subset of the heavy-tailed class) dispersal kernels to study how short- and long-distance dispersal contribute to the spread of invasive species. I show that both approaches can lead to biphasic range expansions, where an invasion has two distinct phases of spread. In the initial phase of spread, the invasion is controlled by short-distance dispersal. Long-distance dispersal boosts the speed of spread during the ultimate phase, and can have significant effects even when the probability of LDD is vanishingly small. For fat-tailed kernels, I introduce a method of characterizing the “shoulder” of a dispersal kernel, which separates the peak and tail.
Neoarchaean Felsic Volcanic Rocks in Tracing Evolution of Arcs: An Insight from Geochemical Data of the Gadag Schist Belt, Western Dharwar Craton
Authors: Hedge V.S. , Corfu Fernando , Frimmel Hartwig E. , Sawkar R.H. , Korkoppa M.M.
Published: April 2021

Quartz porphyry of rhyolitic composition though a volumetrically minor is an important component of metavolcanic successions in the Gadag schist belt in the western Dharwar craton. The quartz porphyries are calc-alkaline, enriched in light rare earth elements (Lan/Ybn ~ 10-20) and with a strong negative Eu anomaly (Eu/Eu*N = 0.45-0.58). These features, coupled with high K2O/Na2O (0.8 to 1.46), low Nb/Th (<1), and Lan/Smn ratios of 4.2 to 6.0, suggest that rhyolitic magma formed from melt generated by partial melting of basaltic crust, subsequently modified by crustal assimilation and crystal fractionation. The geological setting of the quartz porphyries and the geochemical relationships suggest magmatism at a convergent plate tectonic setting. The zircon U-Pb age of 2588.0 ± 2.4 Ma for the quartz porphyry, together with an age of 2732 Ma for similar volcanic rocks in the Chitradurga schist belt further south, and 2614 Ma for felsic volcanics from the Shimoga schist belt, point to an extended period with episodic arc magmatism in the western Dharwar craton of at least ~144myr.
Watershed Prioritization Based on Morphometric Parameters and PCA Technique: A Case Study of Deonar River Sub Basin, Sidhi Area, Madhya Pradesh, India
Authors: Tiwari Rabindra N. , Kushwaha Vikash K.
Published: April 2021

Watershed prioritization is beneficial for soil, groundwater development as well as for the implementation of the artificial recharge schemes. It is a well-known scientific process of drainage network delineation and ranking of different sub-watersheds of a basin. This is the mostly adopted morphometric interpretation and assessment technique and used for prioritization of watershed. In the present study, morphometric analysis of the Deonar river sub basin has been carried out to interpret and assess its hydrological importance. The study was carried out using geospatial approach and it is reflected in morphometric parameters such as linear, areal and relief aspects of the watershed. Detailed morphometric analysis and drainage map has been prepared from ASTER DEM (digital elevation model) having 30m spatial resolution using GIS environment. The delineated and analysed morphometric parameters are helpful for planning of soil and water conservation with the PCA approach. Principal component analysis (PCA) is a well-known technique that reduces the dimensionality of the given input data set which maximizes the amount of variance information. The delineated drainage order comes 1 to 5 and the watershed comprises of 6 sub-watersheds named as SW-I to SW-VI were analyzed. Based on Deonar river sub basin morphometric analysis, the sub-watershed is categorised into three classes as high, medium and low priority zones. Watershed prioritization and correlation of morphometric parameters of the Deonar river basin illustrates and indicates the high priority due to the greater degree of erosion. The analysed result is useful for making better planning and management, to identify the artificial recharge structures of the various sub-watersheds for improving the water potentiality.
Invasive Lobular Carcinoma of the Breast: Ongoing Trials, Challenges, and Future Directions
Authors: Mukhtar Rita A. , Chien A. Jo
Published: April 2021

Purpose of Review

Invasive lobular carcinoma (ILC) is increasingly recognized as a distinct subtype of breast cancer with unique management challenges. We reviewed currently available clinical trials for patients with ILC.

Recent Findings

We describe the rationale for and study design of clinical trials for patients with both early stage and metastatic ILC. Molecular alterations specific to or enriched in ILC may serve as treatment targets.

ILC has specific features that may be treatment targets. Clinical trials for ILC are available and being developed.
Volume-outcome relationship in rectal cancer surgery
Authors: Siragusa L. , Sensi B. , Vinci D. , Franceschilli M. , Pathirannehalage Don C. , Bagaglini G. , Bellato V. , Campanelli M. , Sica G. S.
Published: April 2021

Introduction

Hospital centralization effect is reported to lower complications and mortality for high risk and complex surgery operations, including colorectal surgery. However, no linear relation between volume and outcome has been demonstrated. Aim of the study was to evaluate the increased surgical volume effect on early outcomes of patient undergoing laparoscopic restorative anterior rectal resection (ARR).

Methods

A retrospective analysis of all consecutive patients undergoing ARR with primary anastomosis between November 2016 and December 2020 after centralization of rectal cancer cases in an academic Centre. Short-term outcomes are compared to those of patients operated in the same unit during the previous 10 years before service centralization. The primary outcome was estimated anastomotic leak rate. Mean operative time, need of conversion, postoperative use of blood transfusion, radicality, in-hospital stay, number and type of complications, readmission and reoperation rate, mortality and 1-year and stoma persistence rates were evaluated as secondary outcomes.

Results

86 patients were operated in the study period and outcomes compared to those of 101 patients operated during the previous ten years. Difference in volume of surgery was significant between the two periods (p 0.019) and the estimated leak rate was significantly lower in the higher volume unit (p 0.047). Mean operative time, need of conversion, postoperative use of blood transfusion and in-hospital stay (p < 0.05) were also significantly reduced in Group A.

Conclusion

This study suggests that the shift toward higher volume in rectal cancer surgery is associated to decreased anastomotic leak rate. Potentiation of lower volume surgical units may yield optimal perioperative outcomes.
Ampoule method fabricated sulfur vacancy-rich N-doped ZnS electrodes for ammonia production in alkaline media
Authors: Feng Da-Ming , Sun Ying , Yuan Zhong-Yong , Fu Yang , Jia Baohua , Li Hui , Ma Tianyi
Published: April 2021

The electrochemical production of green and low-cost ammonia requests the development of high-performance electrocatalysts. In this work, the ampoule method was applied to modulate the surface of the zinc electrode by implanting defects and low-valent active sites. The N-doped ZnS electrocatalyst was thus generated by sulfurization with thiourea and applied for electrocatalytic nitrogen reduction reaction (ENRR). Given the rich sulfur vacancies and abundant Zn-N active sites on the surface, excellent catalytic activity and selectivity were obtained, with an NH3 yield rate of 2.42 × 10–10 mol s−1 cm−2 and a Faradaic efficiency of 7.92% at − 0.6 V vs. RHE in 0.1 M KOH solution. Moreover, the as-synthesized zinc electrode exhibits high stability after five recycling tests and a 24 h potentiostatic test. The comparison with Zn foil, non-doping ZnS/Zn and recent metal sulfide electrocatalysts further demonstrated advanced catalytic performance of N@ZnS/Zn for ENRR. By simple synthesis, S vacancies, and N-doping defects, this promising electrocatalyst would represent a good addition to the arena of transition-metal-based catalysts with superior performance in ENRR.

Graphic abstract
Demand functions and demand manifolds
Authors: Beggs Alan
Published: April 2021

Mrázová and Neary (2017) introduce the notion of the Demand Manifold which expresses the relationship between the elasticity and curvature of a demand function. They argue that this determines many important comparative static properties of firm behavior. This paper gives necessary and sufficient conditions for two demand functions to have the same demand manifold and so to have similar comparative static properties.