bluuebunny/crossref_metadata_2025 huggingface dataset:
Teacher Re-novicing on the Path to Integrating Computational Thinking in High School Physics Instruction
Authors: Lane W. Brian , Galanti Terrie M. , Rozas X. L.
Published: June 2023

Integrating computational thinking (CT) into STEM disciplines requires secondary teachers to develop their pedagogical content knowledge of computing and content integration. Experienced teachers who choose to integrate CT in their secondary STEM courses may struggle in the same ways as novice teachers as they learn about programming and its potential use within their content areas. This study describes these potential struggles as teacher re-novicing in the context of high school physics. The research team facilitated a week-long computing integration workshop for physics teachers (n = 24) from three countries. The teachers engaged with computational learning activities in Jupyter Notebooks with the goal of developing their capacity to integrate Python in physics applications. Qualitative analysis of teacher surveys supported our theorization of a pathway of CT integration knowledge development. We describe these professional learning needs in four illustrative cases, building a grounded theory for teacher re-novicing as a pathway beginning with computing knowledge, moving through physics applications of computing, and arriving at pedagogical knowledge for physics-CT integration.
Ureteroureteral Fistula as a Rare Complication of Ileal Conduit Urinary Diversion: a Case Report
Authors: van Hees Jacqueline E , Buddingh K Tim , van Andel Josje , Roshani Hossain
Published: June 2023

Long-term studies on ileal conduit have shown a complication rate of up to 66%. Fistulas are a rare late complication of ileal conduit. To our knowledge, no data about ureteroureteral fistulas has been published yet. We present the case of a 73-year-old man with non-muscle invasive high-grade urothelial carcinoma of the bladder who failed to BCG due to intolerance and developed a cripple bladder. He underwent a cystoprostatectomy, pelvic lymphadenectomy, and an ileal conduit urinary diversion. Four months after the surgery, a raised creatinine level was discovered. Sonography revealed bilateral hydro-ureteronephrosis. Shortly after, the stomal urinary production became minimal, and a nephrostomy was introduced to the right kidney. As a result, the right- as well as the left-sided hydronephrosis diminished, as assessed by ultrasound. Through a loopogram and anterograde pyelography, a stenosis at the ureteroileal anastomosis as well as a connection between the two ureters was proven. As an endoscopic intervention to resolve the obstruction failed, a re-laparotomy to make a neo-anastomosis from the ureters to the ileal conduit was performed. We suspect that total obliteration of the oral end of the ileal conduit caused fistula formation of the ureters. We would like to address this rare phenomenon as a complication of ileal conduit to be mentioned in the differential diagnosis if the outcome of urine is in question. It is not a simple stenosis of the distal portion of the ureters and demands an adapted surgical reconstructing technique as well.
Maximisation of Bending and Membrane Frequencies of Vibration of Variable Stiffness Composite Laminated Plates by a Genetic Algorithm
Authors: Moreira Simões Tatiana , Ribeiro Pedro , Conceição António Carlos
Published: June 2023

Purpose

In comparison to traditional, constant stiffness laminates, variable stiffness composite laminates (VSCL) with curvilinear fibres represent an extra analysis effort. It is the purpose of this work to present and test a relatively simple optimisation procedure, in order to find the maximum fundamental frequency of vibration in bending and in in-plane vibrations. It is also intended to explain why certain fibre paths lead to higher frequencies.

Methods

The optimisation is performed using a genetic algorithm (GA), which is described in detail. The bending and the in-plane plate models are based on the p-version Finite Element Method. Each model requires a small number of degrees of freedom, an important feature because applying the GA involves the solution of a large number of eigenvalue problems. In order to support the physical interpretation of the optimal designs, mode shapes and stress fields corresponding to some optimal solutions are illustrated.

Results

Single- and multi-layer plates with different boundary conditions and fibre path types are studied. Fibre paths that lead to maximum fundamental frequencies are found and justified. The consequences that maximising the first frequency has on the higher-order modes of vibration are studied.

Conclusion

The proposed optimisation and modelling methods are effective. Curvilinear fibres with the characteristics considered led to the maximum first natural frequency of vibration in a few cases, but not all. Particularly in in-plane vibrations, curvilinear fibres can provide major gains in comparison to straight fibres. The increase in the vibration frequency is accompanied by, overall, larger stresses.
Biogas conversion to liquid fuels via chemical looping single reactor system with CO2 utilization
Authors: Joshi Rushikesh K. , Mohapatra Pinak , Kudva Ishani Karki , Shinde Shekhar G. , Isom Lindsay , Kovach Louann , Pawlikowski John , Cheng Zhuo , Fan Liang-Shih
Published: June 2023

The chemical looping single reactor (CLSR) system utilizing calcium ferrite as oxygen carriers represents an innovative approach to biogas reforming, which has the potential to enhance the efficiency and sustainability of biogas production. In this process, an oxy-combustion burner supplies the necessary endothermic heat while CO2 is simultaneously utilized, resulting in an autothermal process that generates high-purity syngas. Nearly 20% higher CO2 utilization can be achieved compared to the tri-reforming, owing to the higher driving force for CO2 oxidation in the counter-current moving bed and steam knock-out before inletting the flue gas into the reactor bottom. Additionally, the CLSR system is robust to variations in biogas to oxygen carrier ratios and CO2 concentration of the inlet feedstock, maintaining the outlet syngas purity within 1% variation. The effects of temperature, pressure, heat integration, and additional H2O/CO2 flow rate on the system performance are discussed, and the optimized scenarios are used for liquid fuel generation. The proposed process achieves about 13% reduction in syngas requirement compared to the conventional tri-reforming for the same amount of liquid fuel production. The feasibility of the CLSR system is further experimentally verified under various conditions. The results reveal the occurrence of CO2 counter-oxidation reactions on the surface of calcium ferrite oxygen carriers and demonstrate that higher temperatures are beneficial for the CH4 reforming reaction.
On the monogenity of pure quartic relative extensions of $${{\mathbb {Q}}}(i)$$
Authors: Gaál István , Remete László
Published: June 2023

We consider pure quartic relative extensions of the number field $${{\mathbb {Q}}}(i)$$

Q
(
i
)

of type $$K={{\mathbb {Q}}}(\root 4 \of {a+bi})$$

K
=
Q
(

a
+
b
i

4

)

, where $$a,b\in {{\mathbb {Z}}}$$

a
,
b
∈
Z

and $$b\ne 0$$

b
≠
0

, such that $$a+bi\in {{\mathbb {Z}}}[i]$$

a
+
b
i
∈
Z
[
i
]

is square-free. We describe integral bases of these fields. The index form equation is reduced to a relative cubic Thue equation over $${{\mathbb {Q}}}(i)$$

Q
(
i
)

and some corresponding quadratic form equations. We consider monogenity of K and relative monogenity of K over $${{\mathbb {Q}}}(i)$$

Q
(
i
)

. We shall show how our former method based on the factors of the index form can be used in the relative case to exclude relative monogenity in some cases.
String Kernel-Based Techniques for Native Language Identification
Authors: Gurram Vamshi Kumar , Sanil J. , Anoop V. S. , Asharaf S.
Published: June 2023

In recent years, Native Language Identification (NLI) has shown significant interest in computational linguistics. NLI uses an author’s speech or writing in a second language to figure out their native language. This may find applications in forensic linguistics, language teaching, second language acquisition, authorship attribution, identification of spam emails or phishing websites, etc. Conventional pairwise string comparison techniques are computationally expensive and time-consuming. This paper presents fast NLI techniques based on string kernels such as spectrum, presence bits, and intersection string kernels incorporating different learners such as a Support Vector Machine (SVM), Random Forest (RF), and Extreme Gradient Boosting-XGBoost (XGB). Feature sets for the proposed techniques are generated using different combinations of features such as n-word grams and noun phrases. Experimental analyses are carried out using 8235 English as a second language articles from 10 different linguistic backgrounds from a typical NLP benchmark dataset. The experimental results show that the proposed NLI technique incorporating a spectrum string kernel with an RF classifier outperformed existing character n-gram string kernels incorporating SVM, RF, and XGB classifiers. Also, comparable results were observed among different combinations of string kernels. Interestingly, the random forest classifier outperformed SVM and XGB classifiers with different feature sets. All the proposed NLI techniques demonstrated promising results with significant improvement in training time, with the best result attaining more than a 95 percent decrease in training time. The reduced training time of proposed techniques makes it well suited to scale NLI applications for production.
Bedford's Musical Society
Authors: Burrows Donald , Benson Michael , Moore-Colyer Richard
Published: June 2023

The Bedford (Amateur) Musical Society, now Bedford Choral Society, was formed in 1867.
A Descriptive Catalogue of the Medieval Manuscripts of Pembroke College, Cambridge
Authors: Thomson Rodney M.
Published: June 2023

The collection of medieval manuscripts at Pembroke College is an important one. Its most striking feature is that the majority of MSS 1-120 came from the abbey of Bury St Edmunds, as the gift of Thomas Smart in 1599.
Wealth and the Material World in the Old English Alfredian Corpus
Authors: Faulkner Amy
Published: June 2023

A new, materialistic reading of the Alfredian corpus, drawing on diverse approaches from thing theory to Augustinian principles of use and enjoyment to uncover how these works explore the material world.
Governing Europe's Recovery and Resilience Facility: Between Discipline and Discretion
Authors: Bokhorst David , Corti Francesco
Published: June 2023

The EU's Recovery and Resilience Facility (RRF) represents a bold integrationist step in European economic governance. Besides the size of the fiscal envelope, the novelty also lies in the new governance. Member states prepare integrated investment and reform plans and need to fulfil milestones and targets to access funding. This article assesses the balance of power in negotiating the plans and the effect on domestic policymaking. Based on five case studies, we show that the RRF has enhanced the steering capacity of the European Commission on reforms and investments, while member states remain ultimately in charge of the plans. Second, we argue that, while the RRF enhances the efficiency of the policymaking process and allows the fast-forwarding of reforms, it has also led to a contractualization of the relationship with the EU and a centralization of decision-making processes within member states. This latter aspect may hamper ownership and legitimacy in policy implementation.
Antibiotic use in Canadian neonatal intensive care units: a national survey for developing antimicrobial stewardship targets
Authors: Richter Lindsay L. , Ho Matthew Sai-pong , Dunn Michael S. , Lee Kyong-Soon , Robinson Joan L. , Roberts Ashley , Thampi Nisha , Gupta-Bhatnagar Shikha , Shah Prakesh S. , Ting Joseph Y.
Published: June 2023

A survey was conducted among Canadian tertiary neonatal intensive care units. Of the 27 sites who responded, 9 did not have any form of antimicrobial stewardship, and 11 used vancomycin for empirical coverage in late-onset-sepsis evaluations. We detected significant variations in the diagnostic criteria for urinary tract infection and ventilator-associated pneumonia.
THE STRENGTH OF AN AXIOM OF FINITE CHOICE FOR BRANCHES IN TREES
Authors: GOH JUN LE
Published: June 2023

In their logical analysis of theorems about disjoint rays in graphs, Barnes, Shore, and the author (hereafter BGS) introduced a weak choice scheme in second-order arithmetic, called the
$\Sigma ^1_1$
axiom of finite choice (hereafter finite choice). This is a special case of the
$\Sigma ^1_1$
axiom of choice (
$\Sigma ^1_1\text {-}\mathsf {AC}_0$
) introduced by Kreisel. BGS showed that
$\Sigma ^1_1\text {-}\mathsf {AC}_0$
suffices for proving many of the aforementioned theorems in graph theory. While it is not known if these implications reverse, BGS also showed that those theorems imply finite choice (in some cases, with additional induction assumptions). This motivated us to study the proof-theoretic strength of finite choice. Using a variant of Steel forcing with tagged trees, we show that finite choice is not provable from the
$\Delta ^1_1$
-comprehension scheme (even over
$\omega $
-models). We also show that finite choice is a consequence of the arithmetic Bolzano–Weierstrass theorem (introduced by Friedman and studied by Conidis), assuming
$\Sigma ^1_1$
-induction. Our results were used by BGS to show that several theorems in graph theory cannot be proved using
$\Delta ^1_1$
-comprehension. Our results also strengthen results of Conidis.
Monitoring herbage mass and pasture growth rate of large grazing areas: a comparison of the correspondence, cost and reliability of indirect methods
Authors: Ortega G. , Chilibroste P. , Garrido J. M. , Waller A. , Fariña S. R. , Lattanzi F. A.
Published: June 2023

Timely grazing decision-making requires routine information on the herbage mass (HM) and pasture growth rate (GR). The aim of this study was to compare the correspondence, cost and reliability of two indirect methods –the comparative yield method (COMPYLD) and the pasture-meter (CDAX)– to estimate HM and weekly GR of a 42 ha grazing area. Weekly assessments from April 2017 to October 2018 were made with both methods to estimate HM and GR of 13 individual paddocks. In addition, estimated GR were compared to aerial net primary productivity (ANPP) estimated using remote sensing (SAT). Estimated HM was 22% lower for COMPYLD than CDAX (HMCOMPYLD = 33 + 0.78*HMCDAX, R2 = 0.61, CV = 17%, RMSE = 291 kgDM/ha). The correspondence between methods of estimated weekly GR of individual paddocks was weak (GRCDAX = 0.18*GRCOMPYLD + 19.1, R2 = 0.05, CV = 73%, RMSE = 21.8 kgDM/ha/d). However, when integrated in three-week moving-averages, over the complete grazing area, COMPYLD and CDAX yielded similar GR up to 35 kg DM/ha/d. Accumulating GR of the grazing area over one year resulted similar to annual SAT-estimated ANPP. These results imply that, on one hand, decisions based on nominal HM, such as target HM and grazing strip size, would need to be adjusted depending on the method, but on the other hand, decisions based in temporal trends or GR, such as size and timing of set-aside areas for reserves, would be unaffected by method. Compared with COMPYLD, CDAX would be advantageous whenever high labour costs offset higher amortization, maintenance and fuel costs, provided there is an alternative in place to monitor during downtime periods.
Visualizing design project team and individual progress using NLP: a comparison between latent semantic analysis and Word2Vector algorithms
Authors: Chiu Matt , Lim Siska , Silva Arlindo
Published: June 2023

Design has always been seen as an inherently human activity and hard to automate. It requires a lot of traits that are seldom attributable to machines or algorithms. Consequently, the act of designing is also hard to assess. In particular in an educational context, the assessment of progress of design tasks performed by individuals or teams is difficult, and often only the outcome of the task is assessed or graded. There is a need to better understand, and potentially quantify, design progress. Natural Language Processing (NLP) is one way of doing so. With the advancement in NLP research, some of its models are adopted into the field of design to quantify a design class performance. To quantify and visualize design progress, the NLP models are often deployed to analyze written documentation collected from the class participants at fixed time intervals through the span of a course. This paper will explore several ways of using NLP in assessing design progress, analyze its advantages and shortcomings, and present a case study to demonstrate its application. The paper concludes with some guidelines and recommendations for future development.
Associations of the digit ratio with adolescent behavior problems are inconsistent with an intrauterine androgenic origin
Authors: Seeley Allison L. , Mora-Plazas Mercedes , Oliveros Henry , Marín Constanza , Villamor Eduardo
Published: June 2023

A low second-to-fourth digit ratio (2D:4D) is a purported biomarker of increased intrauterine androgenic exposure, presumably linked to postnatal behavior. We aimed to examine the associations between 2D:4D and adolescence behavior problems expected from high (externalizing and attention problems) or low (internalizing problems) prenatal androgen exposure. We conducted a cross-sectional study of 1042 Colombian schoolchildren aged 11–18 y. We examined whether caliper-assessed 2D:4D was associated with behavior problems per the Youth Self-Report questionnaire. Mean problem standardized score point differences were estimated between hand- and sex-specific quintiles of 2D:4D with use of multivariable linear regression. Lower right-hand 2D:4D was associated with decreased externalizing and internalizing behavior problem scores. Corresponding lowest-to-median quintile adjusted mean differences (95% CI) were −4.6 (−7.5, −1.7) and −3.5 (−6.4, −0.6) points in boys; and −3.4 (−5.9, −0.9) and −3.5 (−6.2, −0.8) points in girls. Lower right-hand 2D:4D was also related to less attention and thought problems in boys, and to less social problems among girls. Associations were nonlinear, apparent only below 2D:4D medians, and stronger with the right than the left hand. In conclusion, right-hand 2D:4D is related to behavior problems in adolescence in directions that are not fully consistent with an androgenic exposure origin.
The Maryland (USA) Critical Care Coordination Center (C4): From Pandemic to Permanence
Authors: Kelly Melissa A. , Pinet-Peralta Luis M. , Roque Tara M. , Scalea Thomas M. , Delbridge Theodore R. , Galvagno Samuel M.
Published: June 2023

Introduction:

The 2019 coronavirus disease (COVID-19) pandemic created overwhelming demand for critical care services within Maryland’s (USA) hospital systems. As intensive care units (ICUs) became full, critically ill patients were boarded in hospital emergency departments (EDs), a practice associated with increased mortality and costs. Allocation of critical care resources during the pandemic requires thoughtful and proactive management strategies. While various methodologies exist for addressing the issue of ED overcrowding, few systems have implemented a state-wide response using a public safety-based platform. The objective of this report is to describe the implementation of a state-wide Emergency Medical Services (EMS)-based coordination center designed to ensure timely and equitable access to critical care.

Methods:

The state of Maryland designed and implemented a novel, state-wide Critical Care Coordination Center (C4) staffed with intensivist physicians and paramedics purposed to ensure appropriate critical care resource management and patient transfer assistance. A narrative description of the C4 is provided. A retrospective cohort study design was used to present requests to the C4 as a case series report to describe the results of implementation.

Results:

Providing a centralized asset with regional situational awareness of hospital capability and bed status played an integral role for directing the triage process of critically ill patients to appropriate facilities during and after the COVID-19 pandemic. A total of 2,790 requests were received by the C4. The pairing of a paramedic with an intensivist physician resulted in the successful transfer of 67.4% of requests, while 27.8% were managed in place with medical direction. Overall, COVID-19 patients comprised 29.5% of the cohort. Data suggested increased C4 usage was predictive of state-wide ICU surges. The C4 usage volume resulted in the expansion to pediatric services to serve a broader age range. The C4 concept, which leverages the complimentary skills of EMS clinicians and intensivist physicians, is presented as a proposed public safety-based model for other regions to consider world-wide.

Conclusion:

The C4 has played an integral role in the State of Maryland’s pledge to its citizens to deliver the right care to the right patient at the right time and can be considered as a model for adoption by other regions world-wide.
The Cult of the Relevant: International Relations Scholars and Policy Engagement Beyond the Ivory Tower
Authors: Hendrix Cullen S. , Macdonald Julia , Powers Ryan , Peterson Susan , Tierney Michael J.
Published: June 2023

Over the past fifteen years, a narrative has developed that IR scholars have become a “cult of the irrelevant,” with declining influence on and engagement with policy debates. Despite these assertions, the evidence for limited policy engagement has been anecdotal. We investigate the extent of policy engagement—the ways in which IR scholars participate in policy-making processes and/or attempt to shape those processes—by surveying IR scholars directly about their engagement activities. We find policy engagement is pervasive among IR scholars. We draw on theories of credit-claiming to motivate expectations about how and when scholars are likely to engage with practitioners. Consistent with our expectations, much of this engagement comes in forms that involve small time commitments and provide opportunities for credit-claiming, such as media appearances and short-form, bylined op-eds and blog posts. However, sizable minorities report engaging in consulting activities not for attribution/publication and writing policy briefs, and a majority of respondents indicate they engaged in these activities several times a year or more. We find only small differences in engagement across gender and rank. Our results demonstrate that, for IR scholars, some form of policy engagement is the norm.
Power in a Union: How Unexpected Group Partnerships Form
Authors: Heersink Boris , Lacombe Matthew J.
Published: June 2023

While scholars have focused extensively on the consequences of partnerships between interest groups, less attention has been paid to the historical dynamics shaping when, how, and why such groups unite. This is especially true of “unexpected” partnerships, which unite groups with seemingly little in common. Such partnerships are important, as they can reshape to an unusual degree which actors, issues, and ideas “fit together” politically. We address the puzzle of how unexpected group partnerships form through case studies of previously non-existent alliances between labor unions and the gay/lesbian rights movement in the United States and United Kingdom in the 1970s and 1980s. Using these cases, we produce a theory arguing that unexpected partnerships are a product of a favorable political opportunity structure—present when each group experiences shared threats and mutual vulnerabilities—and the actions of entrepreneurial group leaders, who forge cross-group identities, accentuate shared ideological convictions, and build institutional ties.
Occurrence and diversity of poisonous plants in urban community gardens
Authors: Sebald Veronica , Schmack Julia , Egerer Monika
Published: June 2023

Urban community gardens promote human health, offer recreational space and support urban biodiversity. Urban gardens are situated in diverse landscape contexts and have diverse social contexts with gardeners of various horticultural experiences and backgrounds, both of which results in the wide plant species variety of urban garden habitats. These plants represent a range of traits, one of which may be the production of substances that are poisonous to humans. These plants may also be of ecosystem functioning and biodiversity conservation value, creating an ecosystem service trade-off of human health promotion. In this paper, we report on the occurrence of poisonous plant species in 30 urban community gardens in two German cities (Berlin, Munich) and discuss potential concerns around poisonous and highly poisonous plants in urban gardens. We conclude that, depending on the garden participants as well as the goals of the garden organization, poisonous plants should be carefully monitored and managed to dually mitigate health risks while supporting biodiversity conservation. We propose possible strategies to manage potential threats posed by these plants while simultaneously allowing them to reside alongside people in urban gardens.
Pre-colonial centralization and tax compliance norms in contemporary Uganda
Authors: Ali Merima , Fjeldstad Odd-Helge
Published: June 2023

The paper examines the legacy of pre-colonial centralization on tax compliance norms of citizens in contemporary Uganda. Using a regression discontinuity analysis on neighboring ethnic homelands with different levels of pre-colonial centralization, we find that pre-colonial centralization is correlated with stronger norm for tax compliance. The result is explained by the legacy of location-specific capacity of centralized states in upholding authority and a strong social cohesion exhibited through higher interpersonal trust but not through trust in public institutions.
Scaling of Repeating Earthquakes at the Transition From Aseismic to Seismic Slip
Authors: Lengliné O. , Ampuero J. P. , Schmittbuhl J.
Published: June 2023

Some observations of repeating earthquakes show an unusual, non‐self‐similar scaling between seismic moment and corner frequency, a source property related to rupture size. These observations have been mostly reported in regions at the transition from stable to unstable slip, in geothermal reservoirs and subduction zones. What controls the non self‐similarity of these ruptures and how this is linked to the frictional stability of the interface are still open questions. Here we develop seismic cycle simulations of a single unstable slipping patch to investigate the mechanisms underlying this behavior. We show that temporal changes of normal stress on a fault can produce ruptures that exhibit the observed anomalous scaling. Our results highlight the role of fault zone fluid pressure in modulating the effective normal stress and contributing to the sliding stability of the fault.
Wet and Dry Cold Surges Over the Maritime Continent
Authors: Tan I. , Reeder M. J. , Singh M. S. , Birch C. E. , Peatman S. C.
Published: June 2023

Cold surges are synoptic weather systems that occur over the Maritime Continent during the boreal winter. They are characterized by the strengthening of prevailing low‐level northerly to north‐easterly winds, temperature falls of a few degrees over several days, and in some cases, heavy prolonged rainfall and flooding. We investigate the synoptic structure and development of cold surges through composites of dry, moderate and wet surges. Each surge category is defined by the distribution of precipitation averaged within a specified domain over the equatorial South China Sea. Dry surges are characterized by cross‐equatorial flow and positive mean sea‐level pressure anomalies that reach the Southern Hemisphere, and enhanced descent or weaker ascent. Wet surges are characterized by limited cross‐equatorial flow, low‐pressure anomalies over the equator, and enhanced moisture and ascent. The local diurnal precipitation patterns are consistent with the convection being controlled by the mid‐tropospheric buoyancy of an idealized entraining plume. This buoyancy diagnostic suggests that wet surges are characterized by a moister free troposphere because this reduces the effect of entrainment and allows deep convection to develop. On the large scale, the environment in which wet or dry cold surges form is closely related to the Madden‐Julian Oscillation (MJO) phase. Dry and moderate surges occur predominantly in the suppressed phases of the MJO, while wet surges often herald the eastward propagation of the MJO convective envelope. Finally, convectively active phases in the Australian monsoon are more likely following dry cold surges, and are sometimes associated with the MJO.
Climate Evolution Through the Onset and Intensification of Northern Hemisphere Glaciation
Authors: McClymont E. L. , Ho S. L. , Ford H. L. , Bailey I. , Berke M. A. , Bolton C. T. , De Schepper S. , Grant G. R. , Groeneveld J. , Inglis G. N. , Karas C. , Patterson M. O. , Swann G. E. A. , Thirumalai K. , White S. M. , Alonso‐Garcia M. , Anand P. , Hoogakker B. A. A. , Littler K. , Petrick B. F. , Risebrobakken B. , Abell J. T. , Crocker A. J. , de Graaf F. , Feakins S. J. , Hargreaves J. C. , Jones C. L. , Markowska M. , Ratnayake A. S. , Stepanek C. , Tangunan D.
Published: June 2023

The Pliocene Epoch (∼5.3–2.6 million years ago, Ma) was characterized by a warmer than present climate with smaller Northern Hemisphere ice sheets, and offers an example of a climate system in long‐term equilibrium with current or predicted near‐future atmospheric CO2concentrations (pCO2). A long‐term trend of ice‐sheet expansion led to more pronounced glacial (cold) stages by the end of the Pliocene (∼2.6 Ma), known as the “intensification of Northern Hemisphere Glaciation” (iNHG). We assessed the spatial and temporal variability of ocean temperatures and ice‐volume indicators through the late Pliocene and early Pleistocene (from 3.3 to 2.4 Ma) to determine the character of this climate transition. We identified asynchronous shifts in long‐term means and the pacing and amplitude of shorter‐term climate variability, between regions and between climate proxies. Early changes in Antarctic glaciation and Southern Hemisphere ocean properties occurred even during the mid‐Piacenzian warm period (∼3.264–3.025 Ma) which has been used as an analog for future warming. Increased climate variability subsequently developed alongside signatures of larger Northern Hemisphere ice sheets (iNHG). Yet, some regions of the ocean felt no impact of iNHG, particularly in lower latitudes. Our analysis has demonstrated the complex, non‐uniform and globally asynchronous nature of climate changes associated with the iNHG. Shifting ocean gateways and ocean circulation changes may have pre‐conditioned the later evolution of ice sheets with falling atmosphericpCO2. Further development of high‐resolution, multi‐proxy reconstructions of climate is required so that the full potential of the rich and detailed geological records can be realized.
ChatGPT: A Threat or an Opportunity for Scientists?
Authors: Florindo F.
Published: June 2023

The emergence of artificial intelligence (AI) has brought about numerous opportunities and challenges for scientists in various fields. One notable advancement in AI is OpenAI’s ChatGPT (Generative Pretrained Transformer), a powerful language model based on the GPT‐3.5 architecture that can generate text resembling human‐like responses. Like any technological advancement, the risk‐benefit opinions of ChatGPT diverge among scientists. This paper explores the implications of AI and, in particular, ChatGPT, delving into its potential as both a threat and an opportunity for scientists. It examines the risks associated with misinformation, ethical considerations, and the impact on traditional research processes. Ultimately, the argument put forth is that while ChatGPT and chatbots like it do present challenges, they also have the potential to significantly transform scientific inquiry and foster innovation.
As Wildfires Grow, So Could Methane Emissions
Authors: Smith Derek
Published: June 2023

Wildfires that wreaked havoc on California in 2020 filled the atmosphere with a potent greenhouse gas.
A New Model for Charge Separation by Proton Transfer During Collision Between Ice Particles in Thunderstorms
Authors: Kang Heon , Jayaratne Rohan , Williams Earle
Published: June 2023

Field and laboratory observations strongly support the view that the development of electric fields in thunderstorms is caused by charge separation during rebounding collisions between ice crystals and graupels, followed by their gravitational separation. Although several plausible microphysical mechanisms have been proposed to explain the physics of charge separation, none have been found to be fully consistent with the experimental evidence, and a fresh approach is necessary. We propose a new mechanism for charge separation in ice‐ice collisions based on the fundamental molecular mechanism of charge transport in ice, involving the diffusion of H+ ions (excess protons or positive ionic defects) via a proton hopping relay along the hydrogen‐bond network of ice and the trapping and release of H+ ions from L‐orientational defects. The collision of two ice particles leads to the formation of a transient crystalline ice bridge at the contact point, which is spontaneously driven by the tendency for ice sintering, permitting rapid H+ diffusion between the two particles. Charge separation is achieved by the asymmetry in the concentrations of H+ ions or L‐orientational defects between the two ice surfaces. The proposed H+ transport mechanism successfully explains the direction and magnitude of charge transfer as well as its dependence on the relative growth rates of the two ice surfaces observed in laboratory studies. In addition, it offers a molecular‐level interpretation of the empirical rule that, during a collision, the faster‐growing ice surface is positively charged at the expense of negative charging of the slower‐growing or sublimating ice surface.
Key triggers of adaptive genetic variability of sessile oak [Q. petraea (Matt.) Liebl.] from the Balkan refugia: outlier detection and association of SNP loci from ddRAD-seq data
Authors: Tóth Endre Gy. , Cseke Klára , Benke Attila , Lados Botond B. , Tomov Vladimir T. , Zhelev Petar , Kámpel József D. , Borovics Attila , Köbölkuti Zoltán A.
Published: June 2023

Knowledge on the genetic composition of Quercus petraea in south-eastern Europe is limited despite the species’ significant role in the re-colonisation of Europe during the Holocene, and the diverse climate and physical geography of the region. Therefore, it is imperative to conduct research on adaptation in sessile oak to better understand its ecological significance in the region. While large sets of SNPs have been developed for the species, there is a continued need for smaller sets of SNPs that are highly informative about the possible adaptation to this varied landscape. By using double digest restriction site associated DNA sequencing data from our previous study, we mapped RAD-seq loci to the Quercus robur reference genome and identified a set of SNPs putatively related to drought stress-response. A total of 179 individuals from eighteen natural populations at sites covering heterogeneous climatic conditions in the southeastern natural distribution range of Q. petraea were genotyped. The detected highly polymorphic variant sites revealed three genetic clusters with a generally low level of genetic differentiation and balanced diversity among them but showed a north–southeast gradient. Selection tests showed nine outlier SNPs positioned in different functional regions. Genotype-environment association analysis of these markers yielded a total of 53 significant associations, explaining 2.4–16.6% of the total genetic variation. Our work exemplifies that adaptation to drought may be under natural selection in the examined Q. petraea populations.
Bipartite genome and structural organization of the parvovirus Acheta domesticus segmented densovirus
Authors: Pénzes Judit J. , Pham Hanh T. , Chipman Paul , Smith Emmanuel W. , McKenna Robert , Tijssen Peter
Published: June 2023

Parvoviruses (family Parvoviridae) are currently defined by a linear monopartite ssDNA genome, T = 1 icosahedral capsids, and distinct structural (VP) and non-structural (NS) protein expression cassettes within their genome. We report the discovery of a parvovirus with a bipartite genome, Acheta domesticus segmented densovirus (AdSDV), isolated from house crickets (Acheta domesticus), in which it is pathogenic. We found that the AdSDV harbors its NS and VP cassettes on two separate genome segments. Its vp segment acquired a phospholipase A2-encoding gene, vpORF3, via inter-subfamily recombination, coding for a non-structural protein. We showed that the AdSDV evolved a highly complex transcription profile in response to its multipartite replication strategy compared to its monopartite ancestors. Our structural and molecular examinations revealed that the AdSDV packages one genome segment per particle. The cryo-EM structures of two empty- and one full-capsid population (3.3, 3.1 and 2.3 Å resolution) reveal a genome packaging mechanism, which involves an elongated C-terminal tail of the VP, “pinning” the ssDNA genome to the capsid interior at the twofold symmetry axis. This mechanism fundamentally differs from the capsid-DNA interactions previously seen in parvoviruses. This study provides new insights on the mechanism behind ssDNA genome segmentation and on the plasticity of parvovirus biology.
Relationships of temperature and biodiversity with stability of natural aquatic food webs
Authors: Zhao Qinghua , Van den Brink Paul J. , Xu Chi , Wang Shaopeng , Clark Adam T. , Karakoç Canan , Sugihara George , Widdicombe Claire E. , Atkinson Angus , Matsuzaki Shin-ichiro S. , Shinohara Ryuichiro , He Shuiqing , Wang Yingying. X. G. , De Laender Frederik
Published: June 2023

Temperature and biodiversity changes occur in concert, but their joint effects on ecological stability of natural food webs are unknown. Here, we assess these relationships in 19 planktonic food webs. We estimate stability as structural stability (using the volume contraction rate) and temporal stability (using the temporal variation of species abundances). Warmer temperatures were associated with lower structural and temporal stability, while biodiversity had no consistent effects on either stability property. While species richness was associated with lower structural stability and higher temporal stability, Simpson diversity was associated with higher temporal stability. The responses of structural stability were linked to disproportionate contributions from two trophic groups (predators and consumers), while the responses of temporal stability were linked both to synchrony of all species within the food web and distinctive contributions from three trophic groups (predators, consumers, and producers). Our results suggest that, in natural ecosystems, warmer temperatures can erode ecosystem stability, while biodiversity changes may not have consistent effects.
Culturing of a complex gut microbial community in mucin-hydrogel carriers reveals strain- and gene-associated spatial organization
Authors: Jin Xiaofan , Yu Feiqiao B. , Yan Jia , Weakley Allison M. , Dubinkina Veronika , Meng Xiandong , Pollard Katherine S.
Published: June 2023

Microbial community function depends on both taxonomic composition and spatial organization. While composition of the human gut microbiome has been deeply characterized, less is known about the organization of microbes between regions such as lumen and mucosa and the microbial genes regulating this organization. Using a defined 117 strain community for which we generate high-quality genome assemblies, we model mucosa/lumen organization with in vitro cultures incorporating mucin hydrogel carriers as surfaces for bacterial attachment. Metagenomic tracking of carrier cultures reveals increased diversity and strain-specific spatial organization, with distinct strains enriched on carriers versus liquid supernatant, mirroring mucosa/lumen enrichment in vivo. A comprehensive search for microbial genes associated with this spatial organization identifies candidates with known adhesion-related functions, as well as novel links. These findings demonstrate that carrier cultures of defined communities effectively recapitulate fundamental aspects of gut spatial organization, enabling identification of key microbial strains and genes.
Isolation of full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of Escherichia coli
Authors: Robinson Michael-Paul , Jung Jinjoo , Lopez-Barbosa Natalia , Chang Matthew , Li Mingji , Jaroentomeechai Thapakorn , Cox Emily C. , Zheng Xiaolu , Berkmen Mehmet , DeLisa Matthew P.
Published: June 2023

Here we describe a facile and robust genetic selection for isolating full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of redox-engineered Escherichia coli cells. The method is based on the transport of a bifunctional substrate comprised of an antigen fused to chloramphenicol acetyltransferase, which allows positive selection of bacterial cells co-expressing cytoplasmic IgGs called cyclonals that specifically capture the chimeric antigen and sequester the antibiotic resistance marker in the cytoplasm. The utility of this approach is first demonstrated by isolating affinity-matured cyclonal variants that specifically bind their cognate antigen, the leucine zipper domain of a yeast transcriptional activator, with subnanomolar affinities, which represent a ~20-fold improvement over the parental IgG. We then use the genetic assay to discover antigen-specific cyclonals from a naïve human antibody repertoire, leading to the identification of lead IgG candidates with affinity and specificity for an influenza hemagglutinin-derived peptide antigen.
Divergent molecular signatures in fish Bouncer proteins define cross-fertilization boundaries
Authors: Gert Krista R. B. , Panser Karin , Surm Joachim , Steinmetz Benjamin S. , Schleiffer Alexander , Jovine Luca , Moran Yehu , Kondrashov Fyodor , Pauli Andrea
Published: June 2023

Molecular compatibility between gametes is a prerequisite for successful fertilization. As long as a sperm and egg can recognize and bind each other via their surface proteins, gamete fusion may occur even between members of separate species, resulting in hybrids that can impact speciation. The egg membrane protein Bouncer confers species specificity to gamete interactions between medaka and zebrafish, preventing their cross-fertilization. Here, we leverage this specificity to uncover distinct amino acid residues and N-glycosylation patterns that differentially influence the function of medaka and zebrafish Bouncer and contribute to cross-species incompatibility. Curiously, in contrast to the specificity observed for medaka and zebrafish Bouncer, seahorse and fugu Bouncer are compatible with both zebrafish and medaka sperm, in line with the pervasive purifying selection that dominates Bouncer’s evolution. The Bouncer-sperm interaction is therefore the product of seemingly opposing evolutionary forces that, for some species, restrict fertilization to closely related fish, and for others, allow broad gamete compatibility that enables hybridization.
Liquid metal droplets bouncing higher on thicker water layer
Authors: Dai Yuhang , Li Minfei , Ji Bingqiang , Wang Xiong , Yang Siyan , Yu Peng , Wang Steven , Hao Chonglei , Wang Zuankai
Published: June 2023

Liquid metal (LM) has gained increasing attention for a wide range of applications, such as flexible electronics, soft robots, and chip cooling devices, owing to its low melting temperature, good flexibility, and high electrical and thermal conductivity. In ambient conditions, LM is susceptible to the coverage of a thin oxide layer, resulting in unwanted adhesion with underlying substrates that undercuts its originally high mobility. Here, we discover an unusual phenomenon characterized by the complete rebound of LM droplets from the water layer with negligible adhesion. More counterintuitively, the restitution coefficient, defined as the ratio between the droplet velocities after and before impact, increases with water layer thickness. We reveal that the complete rebound of LM droplets originates from the trapping of a thinly low-viscosity water lubrication film that prevents droplet-solid contact with low viscous dissipation, and the restitution coefficient is modulated by the negative capillary pressure in the lubrication film as a result of the spontaneous spreading of water on the LM droplet. Our findings advance the fundamental understanding of complex fluids’ droplet dynamics and provide insights for fluid control.
Senescent cardiomyocytes contribute to cardiac dysfunction following myocardial infarction
Authors: Redgrave Rachael E. , Dookun Emily , Booth Laura K. , Camacho Encina Maria , Folaranmi Omowumi , Tual-Chalot Simon , Gill Jason H. , Owens W. Andrew , Spyridopoulos Ioakim , Passos João F. , Richardson Gavin D.
Published: June 2023

Myocardial infarction is a leading cause of morbidity and mortality. While reperfusion is now standard therapy, pathological remodelling leading to heart failure remains a clinical problem. Cellular senescence has been shown to contribute to disease pathophysiology and treatment with the senolytic navitoclax attenuates inflammation, reduces adverse myocardial remodelling and results in improved functional recovery. However, it remains unclear which senescent cell populations contribute to these processes. To identify whether senescent cardiomyocytes contribute to disease pathophysiology post-myocardial infarction, we established a transgenic model in which p16 (CDKN2A) expression was specifically knocked-out in the cardiomyocyte population. Following myocardial infarction, mice lacking cardiomyocyte p16 expression demonstrated no difference in cardiomyocyte hypertrophy but exhibited improved cardiac function and significantly reduced scar size in comparison to control animals. This data demonstrates that senescent cardiomyocytes participate in pathological myocardial remodelling. Importantly, inhibition of cardiomyocyte senescence led to reduced senescence-associated inflammation and decreased senescence-associated markers within other myocardial lineages, consistent with the hypothesis that cardiomyocytes promote pathological remodelling by spreading senescence to other cell-types. Collectively this study presents the demonstration that senescent cardiomyocytes are major contributors to myocardial remodelling and dysfunction following a myocardial infarction. Therefore, to maximise the potential for clinical translation, it is important to further understand the mechanisms underlying cardiomyocyte senescence and how to optimise senolytic strategies to target this cell lineage.
Pre-flight body weight effects on urinary calcium excretion in space
Authors: Thamer Semran , Stevanovic Mirjana , Buckey Jay C.
Published: June 2023

Microgravity-induced bone loss increases urinary calcium excretion which increases kidney stone formation risk. Not all individuals show the same degree of increase in urinary calcium and some pre-flight characteristics may help identify individuals who may benefit from in-flight monitoring. In weightlessness the bone is unloaded, and the effect of this unloading may be greater for those who weigh more. We studied whether pre-flight body weight was associated with increased in-flight urinary calcium excretion using data from Skylab and the International Space Station (ISS). The study was reviewed and approved by the National Aeronautics and Space Administration (NASA) electronic Institutional Review Board (eIRB) and data were sourced from the Longitudinal Study of Astronaut Health (LSAH) database. The combined Skylab and ISS data included 45 participants (9 Skylab, 36 ISS). Both weight and day in flight were positively related to urinary calcium excretion. There was also an interaction between weight and day in flight with higher weight associated with higher calcium excretion earlier in the mission. This study shows that pre-flight weight is also a factor and could be included in the risk assessments for bone loss and kidney stone formation in space.