bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examining the upper frequency limit of dynamic cerebral autoregulation: Considerations across the cardiac cycle during eucapnia
Authors: Burma Joel S. , Neill Matthew G. , Fletcher Elizabeth K. S. , Dennett Brooke E. , Johnson Nathan E. , Javra Raelyn , Griffiths James K. , Smirl Jonathan D. 
Published: October 2024

AbstractThere are differences within the literature regarding the upper frequency cut‐off point of the dynamic cerebral autoregulation (CA) high‐pass filter. The projection pursuit regression approach has demonstrated that the upper frequency limit is ∼0.07 Hz, whereas another approach [transfer function analysis (TFA) phase approaching zero] indicated a theoretical upper frequency limit for the high‐pass filter of 0.24 Hz. We investigated how these limits accurately represent the CA upper frequency limit, in addition to extending earlier findings with respect to biological sexes and across the cardiac cycle. Sixteen participants (nine females and seven males) performed repeated squat–stand manoeuvres at frequencies of 0.05, 0.10, 0.15, 0.20 and 0.25 Hz, with insonation of the middle and posterior cerebral arteries. Linear regression modelling with adjustment for sex and order of squat completion was used to compared TFA gain and phase with 0.25 Hz (above the theoretical limit of CA). The upper frequency limit of CA with TFA gain was within the range of 0.05–0.10 Hz, whereas TFA phase was within the range of 0.20–0.25 Hz, and consistent between vessels, between sexes and across the cardiac cycle. Females displayed greater middle cerebral artery gain compared with males (all P < 0.047), and no phase differences were present (all P > 0.072). Although sex‐specific differences were present for specific TFA metrics at a given frequency, the upper frequency limit of autoregulation was similar between cerebral conduit vessels, cardiac cycle phase and biological sex. Future work is warranted to determine whether an upper frequency limit exists with respect to hysteresis analyses.
Investigating the effects of artificial baroreflex stimulation on pain perception: A comparative study in no‐pain and chronic low back pain individuals
Authors: Venezia Alessandra , Fawsitt‐Jones Harriet , Hohenschurz‐Schmidt David , Mancini Matteo , Howard Matthew , Makovac Elena 
Published: October 2024

AbstractThe autonomic nervous system (ANS) and pain exhibit a reciprocal relationship, where acute pain triggers ANS responses, whereas resting ANS activity can influence pain perception. Nociceptive signalling can also be altered by ‘top‐down’ processes occurring in the brain, brainstem and spinal cord, known as ‘descending modulation’. By employing the conditioned pain modulation (CPM) paradigm, we previously revealed a connection between reduced low‐frequency heart rate variability and CPM. Individuals with chronic pain often experience both ANS dysregulation and impaired CPM. Baroreceptors, which contribute to blood pressure and heart rate variability regulation, may play a significant role in this relationship, although their involvement in pain perception and their functioning in chronic pain have not been sufficiently explored. In the present study, we combined artificial ‘baroreceptor stimulation’ in both pressure pain and CPM paradigms, seeking to explore the role of baroreceptors in pain perception and descending modulation. In total, 22 individuals with chronic low back pain (CLBP) and 29 individuals with no‐pain (NP) took part in the present study. We identified a differential modulation of baroreceptor stimulation on pressure pain between the groups of NP and CLBP participants. Specifically, NP participants perceived less pain in response to baroreflex activation, whereas CLBP participants exhibited increased pain sensitivity. CPM scores were associated with baseline measures of baroreflex sensitivity in both CLBP and NP participants. Our data support the importance of the baroreflex in chronic pain and a possible mechanism of dysregulation involving the interaction between the ANS and descending pain modulation.
imageKey points
Baroreflex stimulation has different effects on pressure pain in participants with chronic pain compared to matched individuals with no‐pain.
Baroreceptor activation decreases pain in participants with no‐pain but increases pain perception in participants with chronic pain.
Baroreflex sensitivity is associated with conditioned pain modulation in both groups of chronic pain and no‐pain participants.
The reactivity of the baroreflex during autonomic stress demonstrated a positive correlation with Pain Trait scores in participants with chronic back pain.
Chronic late gestation fetal hyperglucagonaemia results in lower insulin secretion, pancreatic mass, islet area and beta‐ and α‐cell proliferation
Authors: Cilvik Sarah N. , Boehmer Brit , Wesolowski Stephanie R. , Brown Laura D. , Rozance Paul J. 
Published: October 2024

AbstractFetal glucagon concentrations are elevated in the presence of a compromised intrauterine environment, as in cases of placental insufficiency and perinatal acidaemia. Our objective was to investigate the impact of late gestation fetal hyperglucagonaemia on in vivo insulin secretion and pancreatic islet structure. Chronically catheterized late gestation fetal sheep received an intravenous infusion of glucagon at low (5 ng/kg/min; GCG‐5) or high (50 ng/kg/min; GCG‐50) concentrations or a vehicle control (CON) for 8–10 days. Glucose‐stimulated fetal insulin secretion (GSIS) was measured following 3 h (acute response) and 8–10 days (chronic response) of experimental infusions. Insulin, glucose and amino acid concentrations were measured longitudinally. The pancreas was collected at the study end for histology and gene expression analysis. Acute exposure (3 h) to GCG‐50 induced a 3‐fold increase in basal insulin concentrations with greater GSIS. Meanwhile, chronic exposure to both GCG‐5 and GCG‐50 decreased basal insulin concentrations 2‐fold by day 8–10. Chronic GCG‐50 also blunted GSIS at the study end. Fetal amino acid concentrations were decreased within 24 h of GCG‐5 and GCG‐50, while there were no differences in fetal glucose. Histologically, GCG‐5 and GCG‐50 had lower β‐ and α‐cell proliferation, as well as lower α‐cell mass and pancreas weight, while GCG‐50 had lower islet area. This study demonstrates that chronic glucagon elevation in late gestation fetuses impairs β‐cell proliferation and insulin secretion, which has the potential to contribute to later‐life diabetes risk. We speculate that the action of glucagon in lower circulating fetal amino acid concentrations may have a suppressive effect on insulin secretion.
imageKey points
We have previously demonstrated in a chronically catheterized fetal sheep model that experimentally elevated glucagon in the fetus impairs placental function, reduces fetal protein accretion and lowers fetal weight.
In the present study, we further characterized the effects of elevated fetal glucagon on fetal physiology with a focus on pancreatic development and β‐cell function.
We show that experimentally elevated fetal glucagon results in lower β‐ and α‐cell proliferation, as well as decreased insulin secretion after 8−10 days of glucagon infusion.
These results have important implications for β‐cell reserve and later‐life predisposition to diabetes.
Cooperative Object Transport Via Non-Contact Prehensile Pushing by Magnetic Forces
Authors: Dokuyucu Halil İbrahim , Gürsel Özmen Nurhan 
Published: October 2024

Abstract
Cooperative robot systems are an essential candidate for object transportation solutions. They offer cost-efficient and flexible operation for various types of robotic tasks. The benefits of cooperative robot systems have triggered the improvement of the object transportation field. In this study, a new way of transporting objects by cooperative robots is presented. The proposed method is performed by the pushing action of the magnetic forces of the robots. The permanent magnets mounted on the mobile robots and the cart create this repelling force. The rectangular object carrier cart equipped with passive caster wheels can be manipulated on flat terrains easily and be assigned to carry different shapes of objects. Using a carrier cart has the advantage of eliminating the vertical loads on the robots. Controlling a non-contact pushing method offers a low computational burden since simple velocity and position updates are adequate for operation management. Compared with the other methods of object transportation systems, the non-contact pushing method provides a faster operation with less sensitivity to control errors. Both simulations and real-world experiments are conducted and the performances are given comparatively with a generalized frictional contact object-pushing method. The results show that the proposed method provides 10.48% faster and 20.03% more accurate object transportation compared to the frictional contact method. It is envisioned that the presented method can be a promising candidate for object transportation tasks in the industry.
Numerical Implementation of Electrostatic Solver Within OpenFOAM for Gas Turbine Intake Filtration
Authors: Pinelli Michele , Piovan Mattia , Suman Alessio , Zanini Nicola , Rossin Stefano , Minotti Stefano 
Published: October 2024

Abstract
Gas turbines require filtered air to preserve operability, availability, and efficiency. Fouling, corrosion, and erosion severely affect the performance of the axial compressor and it can be in part prevented by filtering the air intake. For this reason, several stages of filters can be used in series to catch pollutant particles gradually smaller and with a high level of capturing efficiency. Traditionally, the separation is obtained using cartridges of porous material, which provide a high level of filtration but at the same time generate a pressure drop increasing over time. Another common type of filter is the inertial one, whose operating principle is based on the inertial force acting on the solid particles to separate them from the mainstream. The capturing efficiency of the inertial filter is not comparable with the porous one and for this reason, it is used upstream as a pre-filter. In recent years, another technique has been developed to filter air flows thanks to an electrostatic field, that is induced inside the flow. The electrostatic force generated is able to attract and separate metallic particles. In the present work, numerical investigations are carried out to simulate the effect of the electrostatic force for gas turbine filtering systems. The computational fluid dynamics tool used is openfoam, whose official release can simulate inertial and porous filtering media, while for electrostatic one is not possible due to the absence of a library able to simulate the electrostatic force that acts on the discrete phase. A new library was developed in order to calculate the electric field, the electric potential, and the charge density of the continuous phase. Simulation results show how the calculation of these quantities allows us to predict the electrostatic force acting on particle flows in the presence of electrostatic fields.
Warm-Up in Triathlon: Do Triathletes Follow the Scientific Guidelines?
Authors: Quagliarotti Claudio , Villanova Simone , Marciano Alessio , López-Belmonte Óscar , Caporali Cristiano , Bottoni Alessandro , Lepers Romuald , Piacentini Maria Francesca 
Published: October 2024

Purpose: Warming up before competition is universally recognized as an effective way to enhance performance. However, only a few articles have directly investigated different warm-up strategies adopted by triathletes and suggested by coaches. The Olympic-distance triathlon is an endurance competition characterized, at least for the elite, by a fast start with a strong correlation to the final position in the race. Thus, executing a proper warm-up protocol would be beneficial in optimizing performance. The present study aimed to provide an overview of the warm-up protocol adopted/suggested by national-caliber triathletes/coaches before an Olympic-distance triathlon race. Methods: Online surveys were created and shared between national- and international-caliber Italian, French, and Spanish triathletes and coaches. Information about the rationale, structure, and specific exercises adopted/suggested during personal warm-up protocols was collected. Thereafter, triathletes were grouped according to the discipline sequence reported. Results: Seventy-nine triathletes and nineteen coaches completed the survey. The cycle–run–swim was the most reported discipline sequence adopted, with a total time of 90.0 (25.0) minutes, against the 62.5 (25.0) minutes suggested by coaches. Conditioning exercises were performed by only 31.6% of triathletes 20 to 10 minutes before the race start. Conclusions: Triathletes who took part in this survey adopted very long protocols with the specific intention of including all disciplines. These results highlight the need to raise awareness in triathletes and coaches on the correct warm-up procedures and to stimulate researchers to design studies that directly investigate the effects of different warm-up protocols before competitions.
Alicyclobacillus suci
produces more guaiacol in media and has duplicate copies of
vdcC
compared to closely related
Alicyclobacillus acidoterrestris
Authors: Roth Katerina , Rana Yadwinder Singh , Worobo Randy , Snyder Abigail B. 
Published: October 2024

ABSTRACT

Some species of the genus
Alicyclobacillus
cause spoilage in juices and other beverages due to the production of guaiacol, a phenolic compound, and off-aroma. However, little is known about the genomic determinants of guaiacol production across the genus. In this study, we found that several of the genes significantly enriched in guaiacol-producing
Alicyclobacillus
spp. are associated with oxidative stress response, including
vdcC
, a phenolic acid decarboxylase putatively responsible for guaiacol synthesis. The food industry recognizes
Alicyclobacillus acidoterrestris
as the primary guaiacol-producing species found in beverages, though that species was recently split into two closely related yet genetically distinct species,
Alicyclobacillus suci
and
A. acidoterrestris
. We found that strains of
A. suci
(63.0 ± 14.2 ppm) produced significantly (
P
< 0.01) more guaiacol on average in media than did strains of
A. acidoterrestris
(25.2 ± 7.0 ppm). Additionally,
A. suci
and
Alicyclobacillus fastidiosus
genomes each had duplicate copies of
vdcC
, while only a single copy of
vdcC
was found in the genomes of
A. acidoterrestris, Alicyclobacillus acidiphilus,
and
Alicyclobacillus herbarius
. Although the food industry has not historically differentiated between
A. suci
and
A. acidoterrestris,
it may be increasingly important to target the species with greater spoilage potential. Therefore, we also demonstrated that sequencing a single locus, such as the full-length 16S region or
rpoB,
is sufficient to differentiate between
A. acidoterrestris
and
A. suci
.

IMPORTANCE

Microbial spoilage increases food waste. To address that challenge, it is critical to recognize and control those microbial groups with the greatest spoilage potential. Non-specific targeting of broad microbial groups (e.g., the genus of
Alicyclobacillus
) in which only some members cause food spoilage results in untenable, overly broad interventions. Much of the food industry does not differentiate between guaiacol-producing and non-guaiacol-producing
Alicyclobacillus
species. This is overly broad because
Alicyclobacillus
spp. which cannot produce guaiacol can be present in beverages without causing spoilage. Furthermore, no distinction is made between
Alicyclobacillus suci
and
Alicyclobacillus acidoterrestris
because
A. suci
is newly split from
A. acidoterrestris
and most of the food industry still considers them to be the same. However, these findings indicate that
A. suci
may have greater spoilage potential than
A. acidoterrestris
due to differences in their genomic determinants for guaiacol production.
Investigating oral microbiome dynamics in chronic kidney disease and post-transplantation in continuous culture
Authors: Campbell Paul M. , Willmott Thomas , Summers Angela , Knight Christopher G. , Humphreys Gavin J. , Konkel Joanne E. , Augustine Titus , McBain Andrew J. 
Published: October 2024

ABSTRACT

The oral microbiome is influenced by environmental factors in chronic kidney disease and following kidney transplantation affecting microbial composition, which may have implications for health and recovery. A major driver of oral microbiome perturbation is the accumulation of urea in saliva. We have modelled increased salivary urea concentrations associated with CKD and subsequent reductions that may occur post-transplantation. Oral microbiota were established in constant-depth film fermenters by inoculation with saliva. Duplicate validation runs were maintained with artificial saliva with baseline urea concentrations (0.205 mg/mL) for 21 days. Triplicate treatment runs were then done with baseline urea for 10 days (healthy phase) before urea was increased for 10 days to reflect CKD concentrations (0.92 mg/mL) (CKD phase). This was followed by reversion to baseline urea concentrations (post-transplant phase). Biofilms in primary validation runs reached dynamic stability within 5 days according to viable counting. DNA sequence data indicated minimal taxonomic variation over time and between low and high urea treatments despite background noise indicating changes in bacteria belonging to the family Gemellaceae and the genera TG5 and
Leptotrichia
. Significant differences in alpha and beta diversity occurred between low and high urea states but not following reversion to a low urea environment. Increased abundance of the TG5 was detected in late model phases, despite apparent count stability, and independent of changes in urea concentrations.

IMPORTANCE

This study investigates dynamic changes in the oral microbiome associated with changes in salivary urea concentration, an important factor in chronic kidney disease (CKD). The
in vitro
system modeled increased urea concentrations and subsequent reductions post-transplantation. The study provides insight into the oral microbial shifts during different simulated clinical phases. Understanding these dynamics is crucial for advancing our comprehension of CKD-associated oral microbiome variations and their potential impact on patient well-being and recovery.
Alkali-carbonate melts in the cratonic mantle evidenced by a wehrlite xenolith from the Majuagaa kimberlite, West Greenland
Authors: Kiseeva Ekaterina S. , Kamenetsky Vadim S. , Chayka Ivan F. , Maas Roland , Nielsen Troels F.D. 
Published: October 2024

Abstract
Carbonate melts are critically important for the deep carbon cycle, mantle melting, redox reactions, and transport of highly incompatible elements. The presence of carbonate melts in the cratonic mantle has been inferred from experimental studies, metasomatic transformations, and melt/fluid inclusions in xenoliths, kimberlites, and diamonds. However, the exact composition of such melts is difficult to determine due to their ephemeral nature and highly reactive properties. Once formed, they migrate away from the source and react with silicate mantle minerals, especially orthopyroxene, causing mantle metasomatism. Wehrlite is one of the products of interaction between the carbonate melt and peridotitic mantle and hence is an excellent candidate for locating in situ carbonate melts. Here, we report petrological, geochemical, and melt inclusion data for a garnet wehrlite xenolith in the Majuagaa kimberlite dike, West Greenland. The xenolith, which last equilibrated with the mantle at 4.5 GPa and 1000 °C, contains abundant melt pools composed of dolomite, calcite, serpentine, spinel, apatite, and phlogopite. Although the original magmatic mineralogy was largely destroyed by low-temperature alteration, remnants of the crystallized carbonatitic melt are preserved as primary melt inclusions in the liquidus Ti-Mg-Fe spinel. These melt inclusions, composed of carbonates, alkali carbonates, periclase/brucite, and minor halides, K-sulfide, apatite, and phlogopite, are the first direct evidence for in situ alkali-carbonate melt in the deep cratonic mantle. Compositionally, they are very similar to primary Na-dolomite melt found in experiments and in fluid inclusions within diamonds.
Sediment supply variation control on Lower Eocene delta sequences (Tremp Basin, Spain)
Authors: Vaucher Romain , Musajo Claire , Spangenberg Jorge E. , Poyatos-Moré Miquel , Zeeden Christian , Puigdefàbregas Cai , Prieur Marine , Castelltort Sébastien , Adatte Thierry 
Published: October 2024

Abstract
Sediment supply variations are often overlooked when interpreting depositional sequences, with most studies instead emphasizing changes in accommodation space. Here, we investigated a temporally well-constrained shallow-marine succession in the Tremp Basin to test the control of sediment supply variations on the development of deltaic sequences during the early Eocene. We analyzed the paleoenvironmental record (sedimentary facies and δ13Corg values) of the Morillo Limestone and the Castigaleu Formation (52.2–50.6 Ma). The first progradation of the deltaic system is marked by the abrupt appearance of thick delta-front sandstones and associated with the first negative carbon isotopic excursions (CIEs) in the measured δ13Corg record. Subsequent phases of progradation align with subsequent negative CIEs. Conversely, positive CIEs correspond to finer-grained, more-distal prodelta deposits. A series of hyperthermal events occurred during the deposition, globally identified as negative CIEs on δ13Ccarb reference curves, which we tentatively correlate with our δ13Corg data. We therefore suggest that during deposition of this Lower Eocene shallow-marine succession, the primary trigger behind sequence generation was the high-frequency climate-induced variation in sediment supply, specifically the hyperthermal events, rather than changes in accommodation. This linkage underscores the complex interactions between climate dynamics and sedimentary responses that shape the stratigraphic architecture of shallow-marine settings.
Colour-Electric and Colour-Magnetic Confinement
Authors: Agasian N. O. , Khaidukov Z. V. , Lukashov M. S. , Simonov Yu. A. 
Published: October 2024

Abstract
The basic properties of the confinement mechanism in QCD—the temperature dependence of the spatial and temporal string tensions ($${{\sigma }_{{\text{s}}}}(T)$$ and $${{\sigma }_{{\text{E}}}}(T)$$)—are studied in the framework of the Field Correlator Method (FCM). It is shown that both functions are connected respectively to the spatial and temporal parts of the vacuum gluon energy $${{\epsilon }_{{\text{s}}}}$$ and $${{\epsilon }_{{\text{E}}}}$$ which define their equal values at $$T = 0$$. However at $$T > 0$$ the spatial part is growing with T while the temporal part is destroyed by the hadronic pressure at $$T = {{T}_{{\text{c}}}}$$ (the deconfinement). Both properties are derived within the same method and are in a good agreement with the corresponding lattice data.