bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioerosion features of boring polydorid polychaetes in the North Adriatic Sea
Authors: Pulido Mantas Torcuato , Pola Lisa , Cerrano Carlo , Gambi Maria Cristina , Calcinai Barbara
Published: March 2022

Considering the pivotal role played by erosive organisms in the marine habitat and the scanty knowledge of this phenomenon in the Mediterranean Sea, the present study aimed to identify the pioneer excavating organisms occurring in the first stages of bioerosion, providing the first estimation of their rate of erosion along the North Adriatic Sea. Bioerosion activity was investigated by deploying sets of limestone panels for a period of 2 years. Moreover, micro-computed tomography was used for the first time to study polychaete erosion, confirming it is a very useful tool for the description of erosion processes. Blocks were placed in the touristic harbor Marina Dorica (Ancona) in July 2017 and periodically collected, the first time after a 6-month period, then bimonthly. Two species of the polychaete genusPolydorawere the only boring organisms that settled on the experimental substrates. Erosion rate was estimated by measuring the holes produced by both worm species, and the eroded volumes obtained by resin casts of the holes.Polydoraappeared after 6 months of exposure significantly changing its density rates (holes·100 cm−2·month−1) during the exposure, being comparable with densities reported from tropical areas. The erosion rate on the contrary is lower, reaching values of 0.053 g·cm−2·year−1.
Combined inorganic nitrogen sources influence the release of extracellular compounds that drive mutualistic interactions in microalgal‒bacterial co-cultures
Authors: Perera Isiri Adhiwarie , Abinandan Sudharsanam , Subashchandrabose Suresh R. , Venkateswarlu Kadiyala , Naidu Ravi , Megharaj Mallavarapu
Published: March 2022

We investigated the role of extracellular metabolites released during mutualistic interactions in co-cultures of a microalga,Tetradesmus obliquusIS2 orCoelastrellasp. IS3, and a bacterium,Variovorax paradoxusIS1, grown with varying levels of NO3–N and NH4–N. Both NO3–N and NH4–N were added to modified Bold’s basal medium at 16:0, 12:4, 8:8; 4:12 and 0:16 molar ratios by keeping a final N:P ratio of 16:1. Monocultures of microalgae grown with nitrate alone showed enhanced growth (> twofold) than ammonium, while the bacterial strain cultured with ammonium alone exhibited a > 1.3-fold increase in growth than nitrate. Co-culturing performed higher growth at combined nitrate and ammonium supply as compared to the single cultures. The same ratio of nitrate and ammonium resulted in superior growth of microalgae (> 1.7-fold) and the bacterium (> 4.1-fold) as compared to the monocultures. Uptake of NO3–N, NH4–N and PO4–P by monocultures or co-cultures depended on the ratio of two inorganic nitrogen sources used. The composition of organic acids, amino acids and simple sugars in exudates from monocultures varied with the ratios of nitrate and ammonium in the medium. Thus, the present novel study demonstrates that the release of exudates is affected both qualitatively and quantitatively during mutualistic interactions in microalgal‒bacterial co-cultures under the impact of inorganic nitrogen sources. Our results suggest that the variables such as inorganic nitrogen sources and extracellular metabolites released need to be considered while using co-cultures for effective bioremediation of wastewaters.
Devolution in the U.S. Welfare Reform: Divergence and Degradation in State Benefits
Authors: Ayala Luis , Bárcena-Martín Elena , Martínez-Vázquez Jorge
Published: March 2022

The passage of the Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) in 1996 devolved responsibility for the design of welfare programs from the federal to state governments in the U.S. The strategies implemented to achieve some of the main goals of the reform might have had the effects of reducing the protection received by the most vulnerable households and increasing differences in benefit levels across states. We estimate these effects using Temporary Assistance for Needy Families data covering the two decades after the PRWORA’s enactment. We find that inequality levels across states increased and that a general process of degradation in the adequacy of these cash benefits took place ensuing devolution of welfare reform in the U.S.
Better filterability and reduced radioactivity of phosphogypsum during phosphoric acid production in Morocco using a fly ash waste and pure silica additive
Authors: Arhouni Fatima Ezzahra , Hakkar Mohammed , Mahrou Ahmed , Belahbib Laila , Mazouz Hamid , Haneklaus Nils , Pavón Sandra , Bertau Martin , Boukhair Aziz , Ouakkas Saad , Abdo Maged A. S. , Benjelloun Mohammed
Published: March 2022

Reactive silica additives, such as clays, can increase the filterability of phosphogypsum (PG) during wet phosphoric acid production from phosphate rock (PR). In this study, the effect of adding inexpensive fly ash waste (34 kg per t PR) together with lower quantities of pure silica (8.5 kg per t PR) on the radioactivity of PG was investigated. The addition of fly ash waste/pure silica reduced the radiological activity of the PG by roughly 30%. The reduction was attributed to decreased activities from 238U (60% reduction) and 226Ra (30% reduction) in PG. Besides, P2O5 losses were slightly decreased.
Motivation style of K–12 students attending outreach activities in the STEM field: a person-based approach
Authors: Vennix Johanna , den Brok Perry , Taconis Ruurd
Published: March 2022

This study focused on K–12 students attending outreach activities (i.e. activities from STEM-based industry emphasizing applications of STEM content in the STEM field), with the main objective being to motivate students for a future career in STEM. Outreach activities can be regarded as environments that extend the regular in-class learning environment and that differ from regular environments in terms of several dimensions, such as autonomy, relevance and learning resources. To date, little research has been conducted on these types of learning environments. We followed a person-centred approach in identifying students’ motivational profiles and corresponding student groups in outreach activities, and in evaluating whether students with different profiles differ in their STEM-related attitudes and experience of outreach activities. Both quantitative and qualitative data were collected. Latent-profile analyses revealed four different motivational profiles: good-quality motivation, moderate-motivation, high-quantity motivation and low-quantity motivation. Students with a good-quality motivation reported significantly more favorable-attitudes towards a future career in STEM compared with the other groups, with content and personal relevance being key factors for students with this profile. This study provided support for adding outreach activities to the school learning environment.
Centering Equity and Developing the Maternal Health Workforce: Building the National Maternal Health Learning and Innovation Center
Authors: Reddy Julia , Mullenix Amy , Cannon Abby C. , Epps Deitre , Tucker Christine
Published: March 2022

Purpose

The purpose of this article is to describe the development of the Maternal Health Learning and Innovation Center (MHLIC), a national initiative designed to enhance workforce capacity of maternal health professionals in the United States.

Description

The mission of the MHLIC is to foster collaboration and learning among diverse stakeholders to accelerate evidence-informed approaches advancing equitable maternal health outcomes through engagement, innovation, and policy. Working to center equity in all efforts, the MHLIC builds workforce capacity through partnership, training, technical assistance, coaching, facilitation of peer learning, and a national resource repository.

Assessment

The MHLIC employed several assessment strategies in its first year, including a baseline learning survey of awardees, a stakeholder survey of potential collaborators in maternal health, and advisory convenings. Internally the MHLIC team assessed its own intercultural development. Assessment results informed internal and external approaches to workforce development.

Conclusions

Telehealth implementation, access to services for rural populations, racial inequities, and data use and dissemination were the primary gaps that awardees and other stakeholders identified. The MHLIC is unique in its collaborative design approach and the centering of equity as foundational to the structure, subject, and culture of its work. The MHLIC utilizes a collaborative approach that capitalizes on academic and practice partners’ extensive expertise in maternal health systems. Key to the success of future maternal health efforts is workforce development that builds the awareness and capacity to advance racial and geographic equity for public health, community, and clinical professionals.
‘White Child Gone Bankrupt’—The Intersection of Race and Poverty in Youth Fathered by UN Peacekeepers
Authors: Wagner Kirstin , Bartels Susan A. , Weber Sanne , Lee Sabine
Published: March 2022

Children fathered and abandoned by United Nations peacekeepers are an unintended consequence of peacekeeping operations. Research suggests that the social identity of peacekeeper-fathered children (PKFC) is complex and contradictory. While economically disadvantaged, PKFC’s biracial background confers elements of racial privilege. Using the Democratic Republic of Congo as a case study, the present research evaluates the impact of racial differences on PKFC’s social standing. Drawing on in-depth interviews with a racially heterogeneous sample of 35 PKFC and 60 mothers, we analyse how race and poverty interact and cause PKFC’s conflicting social role. The data demonstrates that being of mixed race leads to the expectation of a higher living standard. Since most PKFC live in extreme economic deprivation, their anticipated privilege contrasts with reality. We found that the stigmatizing effects of poverty were amplified by biracial identification, leading to additional disadvantage, epitomised in the term “Muzungu aliye homba” [white child gone bankrupt]. The findings add to research on ‘children born of war’ and show the role of culture in shaping youth’s social identities. Based on PKFC’s intersecting burdens, we make policy recommendations that address the nexus of race and poverty.
Seeing is relieving: effects of serious storytelling with images on interview performance anxiety
Authors: Lin-Stephens Serene , Manuguerra Maurizio , Bulbert Matthew W.
Published: March 2022

Serious storytelling as a media genre has the potential to accentuate the benefits of narrative interventions in health and education. To inform its application, it is necessary to identify effects of sensory inputs. Here, we focus on visual stimuli and observe their effects on an anxiety condition. We examine whether serious storytelling incorporating images, a type of basic visual stimuli, may reduce interview performance anxiety. In a double-blind randomised control trial, 69 participants with matched levels of anxiety received serious storytelling interview training and were allocated to exposure (image-based preparation) and control (standard preparation) groups. A week later, participants attended individual interviews with two independent interviewers and reported their interview anxiety. Analyses revealed a positive relationship between generalised anxiety and some dimensions of interview anxiety, but serious storytelling with images predicted a reduction in interview performance anxiety (effect size at the median value of covariates on a visual analogue scale with the range 0–100: -36.7, 95% CI [−54.7, −2.5]). Low participation burden in the brief intervention was confirmed through a deductive thematic analysis. The images were analysed based on format type and origin to inform further inquiries. This study yielded empirical findings with implications of media and technology development for serious storytelling. Seeing images of experiences during interview preparation was associated with a relief of interviewees’ anxiety towards interview performance, but further studies are necessary to consolidate the evidence for visual narrative applications in health and education.
Root traits in cover crop mixtures of blue lupin and winter rye
Authors: Kemper Roman , Döring Thomas F. , Legner Nicole , Meinen Catharina , Athmann Miriam
Published: March 2022

Purpose

Mixtures of cover crops are gaining importance in farming systems. While complementarity between species is a potentially important mechanism underlying mixture benefits, there is little quantitative evidence about complementarity of root growth. Therefore, we aimed to gain detailed knowledge about mixture effects of specific root traits.

Methods

Blue lupin (Lupinus angustifolius L.) and winter rye (Secale cereale L.) were grown as sole and intercrops in a two-year organically managed field experiment in Germany. Crops were analysed for shoot biomass and nutrient uptake as well as for root mass density (RMD), root length density (RLD) and specific root length (SRL). We used Fourier transform infrared (FTIR) spectroscopy to discriminate the root mass species-specifically in the mixtures.

Results

In the shoot, overyielding was only found for N and P uptake in the 75:25 mixture of lupin and rye, whereas positive mixture effects of RLD, RMD, and root mass complementarity occurred only in the 50:50 mixture in one year. Consistently positive mixture effects of SRL were found. Root biomass proportion of rye was higher in topsoil, that of lupin higher in subsoil. Vertical niche differentiation in RMD between sole crops and mixtures was not observed.

Conclusion

Among all root traits analysed, consistent mixture effects were observed only for SRL. Mechanisms behind mixture effects of root traits need further research. FTIR spectroscopy discriminated intercrop root mass well. Discrimination of mixture partners’ root length would help to better understand complementarity of root growth in mixtures.
PSII supercomplex disassembly is not needed for the induction of energy quenching (qE)
Authors: Bielczynski Ludwik W. , Xu Pengqi , Croce Roberta
Published: March 2022

Photoprotection by non-photochemical quenching is important for optimal growth and development, especially during dynamic changes of the light intensity. The main component responsible for energy dissipation is called qE. It has been proposed that qE involves the reorganization of the photosynthetic complexes and especially of Photosystem II. However, despite a number of studies, there are still contradictory results concerning the structural changes in PSII during qE induction. The main limitation in addressing this point is the very fast nature of the off switch of qE, since the illumination is usually performed in folio and the preparation of the thylakoids requires a dark period. To avoid qE relaxation during thylakoid isolation, in this work quenching was induced directly on isolated and functional thylakoids that were then solubilized in the light. The analysis of the quenched thylakoids in native gel showed only a small decrease in the large PSII supercomplexes (C2S2M2/C2S2M) which is most likely due to photoinhibition/light acclimation since it does not recover in the dark. This result indicates that qE rise is not accompanied by a structural disassembly of the PSII supercomplexes.
How VEGF-A and its splice variants affect breast cancer development – clinical implications
Authors: Al Kawas Hivin , Saaid Inas , Jank Paul , Westhoff Christina C. , Denkert Carsten , Pross Therese , Weiler Karoline Barbara Stephanie , Karsten Maria Margarete
Published: March 2022

Background

Altered expression levels and structural variations in the vascular endothelial growth factor (VEGF) have been found to play important roles in cancer development and to be associated with the overall survival and therapy response of cancer patients. Particularly VEGF-A and its splice variants have been found to affect physiological and pathological angiogenic processes, including tumor angiogenesis, correlating with tumor progression, mostly caused by overexpression. This review focuses on the expression and impact of VEGF-A splice variants under physiologic conditions and in tumors and, in particular, the distribution and role of isoform VEGF165b in breast cancer.

Conclusions and perspectives

Many publications already highlighted the importance of VEGF-A and its splice variants in tumor therapy, especially in breast cancer, which are summarized in this review. Furthermore, we were able to demonstrate that cytoplasmatic VEGFA/165b expression is higher in invasive breast cancer tumor cells than in normal tissues or stroma. These examples show that the detection of VEGF splice variants can be performed also on the protein level in formalin fixed tissues. Although no quantitative conclusions can be drawn, these results may be the starting point for further studies at a quantitative level, which can be a major step towards the design of targeted antibody-based (breast) cancer therapies.
A longitudinal examination of French and English reading comprehension in French immersion programs in Canada
Authors: Bérubé Daniel , Uchikoshi Yuuko , Marinova-Todd Stefka H.
Published: March 2022

Parental level of education, instruction time, and amount of language practice that children receive have enhanced our understanding of how bilingual and multilingual children learn to comprehend text. Guided by the simple view of reading and the interdependence hypothesis, this longitudinal study conducted in Canadian French immersion programs examined the (a) within- and cross-language association between oral language skills and reading comprehension of bilingual English–French and multilingual children and (b) patterns of growth, while controlling for possible influences of parental level of education and methods of instruction on reading achievement. The sample included 150 children tested once at the beginning of Grade 4 (T1) and again at the end of Grade 4 (T2) and in Grade 6 (T3). Individual growth modeling revealed that bilingual and multilingual children showed similar development in oral language and reading skills across the timeframe. Moreover, growth in English and French reading comprehension was associated with within-language variables. English reading comprehension in Grade 4 was also associated with cross-language variables, including French listening comprehension and vocabulary knowledge. Reading development in the second and third language is enhanced in contexts where classroom instruction, as well as social, economic, and educational opportunities to learn, is equivalent for all students.
Management of the COVID-19 Pandemic: Analysis of the Perception of Professionals of Emergency Medical Systems in Spain after the First Wave
Authors: Castro Delgado Rafael , Cernuda Martínez José Antonio , Romero Pareja Rodolfo , Cuartas Álvarez Tatiana , Arcos González Pedro
Published: March 2022

Objective:

The objective of this study was to identify the perceived problems by medical and nursing professionals that have arisen in the Spanish Emergency Medical Services (EMS) as a consequence of the first wave of the severe acute respiratory syndrome-coronavirus-2/SARS-CoV-2 pandemic, as well as the measures or solutions adopted to manage those problems and improve response.

Method:

This was a cross-sectional study of quantitative and qualitative methodology (“mixed methods”) using a self-administered questionnaire in 23 key informants of EMS of Spain selected by purposeful sampling, followed by the statistical analysis of both types of variables and an integration of the results in the discussion.

Results:

Common problems had been identified in many EMS, as well as similar solutions in some of them. Among the former, the following had been found: lack of leadership and support from managers, initial shortage of personal protective equipment (PPE), lack of participation in decision making, initial lack of clinical protocols, and slowness and/or lack of adaptability of the system, among others. Among the solutions adopted: reinforcement of emergency call centers, development of specific coronavirus disease 2019 (COVID-19) telephone lines and new resources, personal effort of professionals, new functions of EMS, support to other structures, and reinforcement of the role of nursing.

Conclusion:

The general perception among the respondents was that there was a lack of support and communication with health care managers and that the staff expertise was not used by policy makers to make decisions adapted to reality, also expressing the need to improve the capacity for analysis of the EMS response. Few respondents reported good overall satisfaction with their EMS response. The EMS adopted different types of measures to adapt to the COVID-19 pandemic.
Strong Equivalence and Program Structure in Arguing Essential Equivalence between Logic Programs
Authors: LIERLER YULIYA
Published: March 2022

Answer set programming is a prominent declarative programming paradigm used in formulating combinatorial search problems and implementing different knowledge representation formalisms. Frequently, several related and yet substantially different answer set programs exist for a given problem. Sometimes these encodings may display significantly different performance. Uncovering precise formal links between these programs is often important and yet far from trivial. This paper presents formal results carefully relating a number of interesting program rewritings. It also provides the proof of correctness of system projector concerned with automatic program rewritings for the sake of efficiency.
When You Are Wrong on Facebook, Just Admit It
Authors: Fetterman Adam K. , Muscanell Nicole L. , Wu Dongjie , Sassenberg Kai
Published: March 2022

Abstract. Intellectually humble behavior, like admitting when you are wrong, leads to better impression formation. However, online social networks (OSNs) have changed the impression formation process. We investigated the impact of wrongness admission on impression formation during an OSN argument. In four experiments ( N = 679), participants witnessed a user engage in wrongness admission, refuse to admit, or not respond, in an argument on a Facebook wall. Participants reported their impressions of whether they would be willing to interact with the (non)admitting user. User reputation ratings and interaction intentions were higher in the admission (vs. nonadmission) condition. The latter effect was mediated by user reputation ratings. Wrongness admission appears to have a positive impact on impression formation on OSNs.
High Water Contents in Zircons Suggest Water‐Fluxed Crustal Melting During Cratonic Destruction
Authors: Yang Chuan‐Mao , Xu Yi‐Gang , Xia Xiao‐Ping , Yang Jin‐Hui , Sun Jin‐Feng , Zhang Wan‐Feng , Yang Qing , Yang Ya‐Nan
Published: March 2022

Water is essential for the formation of granites, but its origin and role in granite generation (i.e., dehydration vs. water‐fluxed melting) remain uncertain. These issues are addressed by combining water abundances and other geochemical indices in zircons from Late Mesozoic granites generated during the destruction of the North China Craton (NCC). The water contents in zircons from the NCC Early Cretaceous granites (763 ppm, median) are much higher than those of the NCC Jurassic granites (424–513 ppm), upper mantle and continental arc magmas (92–477 ppm). More importantly, the higher water contents in the voluminous Early Cretaceous granites also have higher zircon saturation temperatures, εHf(t), and lower δ18O values. These observations suggest a predominantly mantle origin for the water, and water‐fluxed crustal melting, in which larger water ingression produced more voluminous melts. The high‐water flux was likely related to the subduction of the Paleo‐Pacific Plate, which ultimately destabilized the NCC.
Bending and Collapse: Magnetic Recording Fidelity of Magnetofossils From Micromagnetic Simulation
Authors: Pei Zhaowen , Berndt Thomas A. , Chang Liao , Bai Fan , Williams Wyn , Paterson Greig A.
Published: March 2022

Magnetosome chains produced by magnetotactic bacteria are important paleoenvironmental and paleomagnetic recorders. It has been shown that magnetic properties of magnetosome chains are closely related to their morphology and chain structures; however, the in situ structures of magnetosome chains in sediments (magnetofossils) are not known. Magnetosome chains are subject to various deformations after cell dissolution and are therefore unlikely to be fully intact, obscuring their original magnetic signals. Here, we use finite element micromagnetic simulations to quantify changes in magnetic signals in response to chain deformation, in particular, as a function of variable degrees of bending and collapse. Our results indicate that bending/collapse leads to a significant coercivity reduction and domain state transition of the chain. Therefore, hysteresis parameters can be used to assess the degree of chain bending/collapse in magnetofossil‐rich sediments. Calculations of the contributions of chain bending/collapse to the post‐depositional remanent magnetization (pDRM) of magnetofossils indicate that pDRM remains both faithful to the pre‐bending/collapse natural remanent magnetization, and that the remanence of some structurally deformed magnetofossil assemblages remains thermally stable over billion‐year timescales, suggesting that even strongly deformed magnetosome chains in ancient geological materials retain faithful paleomagnetic records and thus have potentials for tracing ancient geomagnetic field variations and microbial activities on early Earth.
Potential Satellite Monitoring of Surface Organic Soil Properties in Arctic Tundra From SMAP
Authors: Yi Yonghong , Chen Richard H. , Kimball John S. , Moghaddam Mahta , Xu Xiaolan , Euskirchen Eugénie S. , Das Narendra , Miller Charles E.
Published: March 2022

Surface organic carbon content and soil moisture (SM) represent first‐order controls on permafrost thaw and vulnerability, yet remain challenging to map accurately. Here we explored the links between surface organic soil properties and SM dynamics in the Alaska North Slope through data analysis and process‐based modeling. Our analysis, based on in situ SM and brightness temperature data from the Soil Moisture Active Passive (SMAP) mission, indicated that the SM drydown process in Arctic tundra is closely related to surface soil organic carbon (SOC) properties. More rapid drydown was generally observed in areas with high SOC concentration (SOCC) or low bulk density. The drydown timescale derived from the SMAP polarization ratio (PR) was significantly correlated with SoilGrids surface (0–5 cm) SOCC data (R = −0.54 ∼ −0.68, p < 0.01) at regional scale. To understand the process, we used a coupled permafrost hydrology and microwave emission model to simulate changes in the L‐band PR during the thaw season. The model accounts for the variations in organic soil hydraulic and dielectric properties with SOC content and decomposition state. Model sensitivity runs showed larger L‐band PR decreases during the early thaw season in soils with higher SOCC consistent with the above analysis, whereby highly organic soils (SOCC > 34.8%) drain water more easily with a larger amount of water discharged or lost (through evapotranspiration) relative to soils with less carbon concentration (SOCC < 17.4%). Our findings indicate that satellite L‐band observations are sensitive to tundra SM and carbon properties, and may provide critical constraints on predictions of Arctic permafrost thaw and vulnerability.
Distributed representations of atoms and materials for machine learning
Authors: Antunes Luis M. , Grau-Crespo Ricardo , Butler Keith T.
Published: March 2022

The use of machine learning is becoming increasingly common in computational materials science. To build effective models of the chemistry of materials, useful machine-based representations of atoms and their compounds are required. We derive distributed representations of compounds from their chemical formulas only, via pooling operations of distributed representations of atoms. These compound representations are evaluated on ten different tasks, such as the prediction of formation energy and band gap, and are found to be competitive with existing benchmarks that make use of structure, and even superior in cases where only composition is available. Finally, we introduce an approach for learning distributed representations of atoms, named SkipAtom, which makes use of the growing information in materials structure databases.
Pervasive occurrence of splice-site-creating mutations and their possible involvement in genetic disorders
Authors: Sakaguchi Narumi , Suyama Mikita
Published: March 2022

The search for causative mutations in human genetic disorders has mainly focused on mutations that disrupt coding regions or splice sites. Recently, however, it has been reported that mutations creating splice sites can also cause a range of genetic disorders. In this study, we identified 5656 candidate splice-site-creating mutations (SCMs), of which 3942 are likely to be pathogenic, in 4054 genes responsible for genetic disorders. Reanalysis of exome data obtained from ciliopathy patients led us to identify 38 SCMs as candidate causative mutations. We estimate that, by focusing on SCMs, the increase in diagnosis rate is approximately 5.9–8.5% compared to the number of already known pathogenic variants. This finding suggests that SCMs are mutations worth focusing on in the search for causative mutations of genetic disorders.
A late Middle Pleistocene Middle Stone Age sequence identified at Wadi Lazalim in southern Tunisia
Authors: Cancellieri Emanuele , Bel Hadj Brahim Hedi , Ben Nasr Jaafar , Ben Fraj Tarek , Boussoffara Ridha , Di Matteo Martina , Mercier Norbert , Marnaoui Marwa , Monaco Andrea , Richard Maïlys , Mariani Guido S. , Scancarello Olivier , Zerboni Andrea , di Lernia Savino
Published: March 2022

The late Middle Pleistocene, starting at around 300 ka, witnessed large-scale biological and cultural dynamics in hominin evolution across Africa including the onset of the Middle Stone Age that is closely associated with the evolution of our species—Homo sapiens. However, archaeological and geochronological data of its earliest appearance are scarce. Here we report on the late Middle Pleistocene sequence of Wadi Lazalim, in the Sahara of Southern Tunisia, which has yielded evidence for human occupations bracketed between ca. 300–130 ka. Wadi Lazalim contributes valuable information on the spread of early MSA technocomplexes across North Africa, that likely were an expression of large-scale diffusion processes.
Interaction of multi-walled carbon nanotubes in mineral oil based Maxwell nanofluid
Authors: Hanif Hanifa , Shafie Sharidan
Published: March 2022

The most pressing issue now is to improve the cooling process in an electrical power system. On the other hand, nanofluids are regarded as reliable coolants owing to their exceptional characteristics, which include excellent thermal conductivity, a faster heat transfer rate, and higher critical heat flux. Considering these fascinating properties of nanofluid, this research looks at the flow of mineral oil based Maxwell nanofluid with convective heat. Moreover, introducing heat radiation, viscous dissipation and Newtonian heating add to the novelty of the problem. The coupled partial differential equations supported by the accompanying boundary conditions are numerically solved using an implicit finite difference method. The simulations are carried out using MATLAB software, and the obtained results are illustrated graphically. It is observed that the velocity of fluid increases concernign the relaxation time parameter but decreases against fractional derivative.
Numerical study on the effect of capacitively coupled electrical stimulation on biological cells considering model uncertainties
Authors: Zimmermann Julius , Altenkirch Richard , van Rienen Ursula
Published: March 2022

Electrical stimulation of biological samples such as tissues and cell cultures attracts growing attention due to its capability of enhancing cell activity, proliferation, and differentiation. Eventually, a profound knowledge of the underlying mechanisms paves the way for innovative therapeutic devices. Capacitive coupling is one option of delivering electric fields to biological samples that has advantages regarding biocompatibility. However, its biological mechanism of interaction is not well understood. Experimental findings could be related to voltage-gated channels, which are triggered by changes of the transmembrane potential. Numerical simulations by the finite element method provide a possibility to estimate the transmembrane potential. Since a full resolution of the cell membrane within a macroscopic model would lead to prohibitively expensive models, we suggest the adaptation of an approximate finite element method. Starting from a basic 2.5D model, the chosen method is validated and applied to realistic experimental situations. To understand the influence of the dielectric properties on the modelling outcome, uncertainty quantification techniques are employed. A frequency-dependent influence of the uncertain dielectric properties of the cell membrane on the modelling outcome is revealed. This may have practical implications for future experimental studies. Our methodology can be easily adapted for computational studies relying on experimental data.
Novel use of online optimization in a mathematical model of COVID-19 to guide the relaxation of pandemic mitigation measures
Authors: Bianchin Gianluca , Dall’Anese Emiliano , Poveda Jorge I. , Jacobson David , Carlton Elizabeth J. , Buchwald Andrea G.
Published: March 2022

Since early 2020, non-pharmaceutical interventions (NPIs)—implemented at varying levels of severity and based on widely-divergent perspectives of risk tolerance—have been the primary means to control SARS-CoV-2 transmission. This paper aims to identify how risk tolerance and vaccination rates impact the rate at which a population can return to pre-pandemic contact behavior. To this end, we developed a novel mathematical model and we used techniques from feedback control to inform data-driven decision-making. We use this model to identify optimal levels of NPIs across geographical regions in order to guarantee that hospitalizations will not exceed given risk tolerance thresholds. Results are shown for the state of Colorado, United States, and they suggest that: coordination in decision-making across regions is essential to maintain the daily number of hospitalizations below the desired limits; increasing risk tolerance can decrease the number of days required to discontinue NPIs, at the cost of an increased number of deaths; and if vaccination uptake is less than 70%, at most levels of risk tolerance, return to pre-pandemic contact behaviors before the early months of 2022 may newly jeopardize the healthcare system. The sooner we can acquire population-level vaccination of greater than 70%, the sooner we can safely return to pre-pandemic behaviors.
Agents for sequential learning using multiple-fidelity data
Authors: Palizhati Aini , Torrisi Steven B. , Aykol Muratahan , Suram Santosh K. , Hummelshøj Jens S. , Montoya Joseph H.
Published: March 2022

Sequential learning for materials discovery is a paradigm where a computational agent solicits new data to simultaneously update a model in service of exploration (finding the largest number of materials that meet some criteria) or exploitation (finding materials with an ideal figure of merit). In real-world discovery campaigns, new data acquisition may be costly and an optimal strategy may involve using and acquiring data with different levels of fidelity, such as first-principles calculation to supplement an experiment. In this work, we introduce agents which can operate on multiple data fidelities, and benchmark their performance on an emulated discovery campaign to find materials with desired band gap values. The fidelities of data come from the results of DFT calculations as low fidelity and experimental results as high fidelity. We demonstrate performance gains of agents which incorporate multi-fidelity data in two contexts: either using a large body of low fidelity data as a prior knowledge base or acquiring low fidelity data in-tandem with experimental data. This advance provides a tool that enables materials scientists to test various acquisition and model hyperparameters to maximize the discovery rate of their own multi-fidelity sequential learning campaigns for materials discovery. This may also serve as a reference point for those who are interested in practical strategies that can be used when multiple data sources are available for active or sequential learning campaigns.
The cost of non-coordination in urban on-demand mobility
Authors: Kondor Dániel , Bojic Iva , Resta Giovanni , Duarte Fábio , Santi Paolo , Ratti Carlo
Published: March 2022

Over the last 10 years, ride-hailing companies (such as Uber and Grab) have proliferated in cities around the world. While generally beneficial from an economic viewpoint, having a plurality of operators that serve a given demand for point-to-point trips might induce traffic inefficiencies due to the lack of coordination between operators when serving trips. In fact, the efficiency of vehicle fleet management depends, among other things, density of the demand in the city, and in this sense having multiple operators in the market can be seen as a disadvantage. There is thus a tension between having a plurality of operators in the market, and the overall traffic efficiency. To this date, there is no systematic analysis of this trade-off, which is fundamental to design the best future urban mobility landscape. In this paper, we present the first systematic, data-driven characterization of the cost of non-coordination in urban on-demand mobility markets by proposing a simple, yet realistic, model. This model uses trip density and average traffic speed in a city as its input, and provides an accurate estimate of the additional number of vehicles that should circulate due to the lack of coordination between operators—the cost of non-coordination. We plot such cost across different cities—Singapore, New York (limited to the borough of Manhattan in this work), San Francisco, Vienna and Curitiba—and show that due to non-coordination, each additional operator in the market can increase the total number of circulating vehicles by up to 67%. Our findings could support city policy makers to make data supported decisions when regulating urban on-demand mobility markets in their cities. At the same time, our results outline the need of a more proactive government participation and the need for new, innovative solutions that would enable a better coordination of on-demand mobility operators.
Identifying optimal reference genes for gene expression studies in Eurasian spruce bark beetle, Ips typographus (Coleoptera: Curculionidae: Scolytinae)
Authors: Sellamuthu Gothandapani , Bílý Jan , Joga Mallikarjuna Reddy , Synek Jiří , Roy Amit
Published: March 2022

Eurasian spruce bark beetle (Ips typographus [L.]) causes substantial damage to spruce forests worldwide. Undoubtedly, more aggressive measures are necessary to restrict the enduring loss. Finishing genome sequencing is a landmark achievement for deploying molecular techniques (i.e., RNA interference) to manage this pest. Gene expression studies assist in understanding insect physiology and deployment of molecular approaches for pest management. RT-qPCR is a valuable technique for such studies. However, accuracy and reliability depend on suitable reference genes. With the genome sequence available and the growing requirement of molecular tools for aggressive forest pest management, it is crucial to find suitable reference genes in Ips typographus under different experimental conditions. Hence, we evaluated the stability of twelve candidate reference genes under diverse experimental conditions such as biotic (developmental, sex and tissues) and abiotic factors (i.e., temperature and juvenile hormone treatment) to identify the reference genes. Our results revealed that ribosomal protein 3a (RPS3-a) was the best reference gene across all the experimental conditions, with minor exceptions. However, the stability of the reference gene can differ based on experiments. Nevertheless, present study provides a comprehensive list of reference genes under different experimental conditions for Ips typographus and contributes to “future genomic and functional genomic research”.
Coherent surface-to-bulk vibrational coupling in the 2D topologically trivial insulator Bi2Se3 monitored by ultrafast transient absorption spectroscopy
Authors: Glinka Yuri D. , He Tingchao , Sun Xiao Wei
Published: March 2022

Ultrafast carrier relaxation in the 2D topological insulator (TI) Bi2Se3 [gapped Dirac surface states (SS)] and how it inherits ultrafast relaxation in the 3D TI Bi2Se3 (gapless Dirac SS) remains a challenge for developing new optoelectronic devices based on these materials. Here ultrashort (~ 100 fs) pumping pulses of ~ 340 nm wavelength (~ 3.65 eV photon energy) were applied to study ultrafast electron relaxation in the 2D TI Bi2Se3 films with a thickness of 2 and 5 quintuple layers (~ 2 and ~ 5 nm, respectively) using transient absorption (TA) spectroscopy in the ultraviolet–visible spectral region (1.65–3.9 eV). The negative and positive contributions of TA spectra were attributed to absorption bleaching that mostly occurs in the bulk states and to the inverse bremsstrahlung type free carrier absorption in the gapped Dirac SS, respectively. Owing to this direct and selective access to the bulk and surface carrier dynamics, we were able to monitor coherent longitudinal optical (LO) phonon oscillations, which were successively launched in the bulk and surface states by the front of the relaxing electron population within the LO-phonon cascade emission. We have also recognized the coherent surface-to-bulk vibrational coupling that appears through the phase-dependent amplitude variations of coherent LO-phonon oscillations. This unique behavior manifests itself predominantly for the topologically trivial insulator phase of the 2D TI Bi2Se3 (2 nm thick film) in the photon energy range (~ 2.0–2.25 eV) where efficient energy exchange between the bulk and surface states occurs. We also found that the coherent surface-to-bulk vibrational coupling significantly weakens with increasing both the Bi2Se3 film thickness and pumping power.
In vitro evaluation of therapeutic antibodies against a SARS-CoV-2 Omicron B.1.1.529 isolate
Authors: Touret Franck , Baronti Cécile , Bouzidi Hawa Sophia , de Lamballerie Xavier
Published: March 2022

The emergence and rapid spread of the Omicron variant of SARS-CoV-2, which has more than 30 substitutions in the spike glycoprotein, compromises the efficacy of currently available vaccines and therapeutic antibodies. Using a clinical strain of the Omicron variant, we analyzed the neutralizing power of eight currently used monoclonal antibodies compared to the ancestral B.1 BavPat1 D614G strain. We observed that six of these antibodies have lost their ability to neutralize the Omicron variant. Of the antibodies still having neutralizing activity, Sotrovimab/Vir-7831 shows the smallest reduction in activity, with a factor change of 3.1. Cilgavimab/AZD1061 alone shows a reduction in efficacy of 15.8, resulting in a significant loss of activity for the Evusheld cocktail (42.6-fold reduction) in which the other antibody, Tixagevimab, does not retain significant activity against Omicron. Our results suggest that the clinical efficacy of the initially proposed doses should be rapidly evaluated and the possible need to modify doses or propose combination therapies should be considered.
The steroid hormone ecdysone regulates growth rate in response to oxygen availability
Authors: Kapali George P. , Callier Viviane , Gascoigne Samuel J. L. , Harrison Jon F. , Shingleton Alexander W.
Published: March 2022

In almost all animals, physiologically low oxygen (hypoxia) during development slows growth and reduces adult body size. The developmental mechanisms that determine growth under hypoxic conditions are, however, poorly understood. Here we show that the growth and body size response to moderate hypoxia (10% O2) in Drosophila melanogaster is systemically regulated via the steroid hormone ecdysone. Hypoxia increases level of circulating ecdysone and inhibition of ecdysone synthesis ameliorates the negative effect of low oxygen on growth. We also show that the effect of ecdysone on growth under hypoxia is through suppression of the insulin/IGF-signaling pathway, via increased expression of the insulin-binding protein Imp-L2. These data indicate that growth suppression in hypoxic Drosophila larvae is accomplished by a systemic endocrine mechanism that overlaps with the mechanism that slows growth at low nutrition. This suggests the existence of growth-regulatory mechanisms that respond to general environmental perturbation rather than individual environmental factors.
A tradeoff between physical encounters and consumption determines an optimal droplet size for microbial degradation of dispersed oil
Authors: Fernandez Vicente I. , Stocker Roman , Juarez Gabriel
Published: March 2022

Immiscible hydrocarbons occur in the ocean water column as droplets of varying diameters. Although microbial oil degradation is a central process in the remediation of hydrocarbon pollution in marine environments, the relationship between droplet size distribution and oil degradation rates by bacteria remains unclear, with a conflicting history of laboratory studies. Despite this knowledge gap, the use of chemical dispersants in oil spill response and mitigation is based on the rationale that increasing the surface-area-to-volume ratio of droplets will enhance net bacterial biodegradation rates. We demonstrate that this intuitive argument does not apply to most natural marine environments, where the abundance of oil droplets is much lower than in laboratory experiments and droplet-bacteria encounters are the limiting factor. We present a mechanistic encounter-consumption model to predict the characteristic time for oil degradation by marine bacteria as a function of the initial oil concentration, the distribution of droplet sizes, and the initial abundance of oil-degrading bacteria. We find that the tradeoff between the encounter time and the consumption time leads to an optimal droplet size larger than the average size generated by the application of dispersants. Reducing droplet size below this optimum can increase the persistence of oil droplets in the environment from weeks to years. The new perspective granted by this biophysical model of biodegradation that explicitly accounts for oil–microbe encounters changes our understanding of biodegradation particularly in the deep ocean, where droplets are often small and oil concentrations low, and explains degradation rate discrepancies between laboratory and field studies.