bluuebunny/crossref_metadata_2025 huggingface dataset:
Developments in effective use of volatile organic compound analysis to assess flavour formation during cheese ripening
Authors: Yavuz Mustafa , Kasavi Ceyda , Toksoy Öner Ebru
Published: December 2021

In the burgeoning demand for optimization of cheese production, ascertaining cheese flavour formation during the cheese making process has been the focal point of determining cheese quality. In this research reflection, we have highlighted how valuable volatile organic compound (VOC) analysis has been in assessing contingent cheese flavour compounds arising from non-starter lactic acid bacteria (NSLAB) along with starter lactic acid bacteria (SLAB), and whether VOC analysis associated with other high-throughput data might help provide a better understanding the cheese flavour formation during cheese process. It is widely known that there is a keen interest to merge all omics data to find specific biomarkers and/or to assess aroma formation of cheese. Towards that end, results of VOC analysis have provided valuable insights into the cheese flavour profile. In this review, we are pinpointing the effective use of flavour compound analysis to perceive flavour-forming ability of microbial strains that are convenient for dairy production, intertwining microbiome and metabolome to unveil potential biomarkers that occur during cheese ripening. In doing so, we summarised the functionality and integration of aromatic compound analysis in cheese making and gave reflections on reconsidering what the role of flavour-based analysis might have in the future.
Environmental contamination with parasites in selected rural farms in the Philippines: impacts of farming practices on leafy greens food safety
Authors: Paller Vachel Gay V. , Macalinao-Ramirez Constance Aurelle , Bandal Modesto Z.
Published: December 2021

Fresh vegetables are an important part of a healthy diet, however, they can also be agents of transmission of intestinal parasites. This study aimed to evaluate the presence of parasite contamination in vegetable farms as a source of transmission in selected rural communities in Laguna, Philippines. A total of 168 vegetable, 55 soil and 15 water samples collected from four selected farms and a reference farm were processed through various standard parasitological techniques. Of these, 17.3% of vegetables, 47.3% soil and 73.3% water samples were found contaminated with parasites’ eggs or cysts. Interestingly, leafy vegetables, such as lettuce, were found to be more contaminated. Results showed that strongylids/hookworms (egg/larva) showed the highest prevalence in farm soil (38.2%) and vegetable (13.1%); other helminth parasite eggs were also recovered such as Toxocara sp., Ascaris sp., Trichiuris, Trichostrongylus sp. and protozoan cysts of Balantidium coli. Cryptosporidium sp. oocysts of and Giardia sp. cysts were observed in all water samples in the farms. Furthermore, results revealed that some farming practices such as the use of improperly treated animals manure as fertilizers, unhygienic practice of farmers and sanitation issues were factors that contribute to parasite contamination in the farms. These findings have implications on food safety in poor-resource communities posing public health risks. Recommendations were discussed in the study for the control and prevention of parasite contamination at the farm level.
Abnormal dynamic functional connectivity of hippocampal subregions associated with working memory impairment in melancholic depression
Authors: Shunkai Lai , Su Ting , Zhong Shuming , Chen Guangmao , Zhang Yiliang , Zhao Hui , Chen Pan , Tang Guixian , Qi Zhangzhang , He Jiali , Zhu Yunxia , Lv Sihui , Song Zijin , Miao Haofei , Hu Yilei , Jia Yanbin , Wang Ying
Published: December 2021

Background

Previous studies have demonstrated structural and functional changes of the hippocampus in patients with major depressive disorder (MDD). However, no studies have analyzed the dynamic functional connectivity (dFC) of hippocampal subregions in melancholic MDD. We aimed to reveal the patterns for dFC variability in hippocampus subregions – including the bilateral rostral and caudal areas and its associations with cognitive impairment in melancholic MDD.

Methods

Forty-two treatment-naive MDD patients with melancholic features and 55 demographically matched healthy controls were included. The sliding-window analysis was used to evaluate whole-brain dFC for each hippocampal subregions seed. We assessed between-group differences in the dFC variability values of each hippocampal subregion in the whole brain and cognitive performance on the MATRICS Consensus Cognitive Battery (MCCB). Finally, association analysis was conducted to investigate their relationships.

Results

Patients with melancholic MDD showed decreased dFC variability between the left rostral hippocampus and left anterior lobe of cerebellum compared with healthy controls (voxel p < 0.005, cluster p < 0.0125, GRF corrected), and poorer cognitive scores in working memory, verbal learning, visual learning, and social cognition (all p < 0.05). Association analysis showed that working memory was positively correlated with the dFC variability values of the left rostral hippocampus-left anterior lobe of the cerebellum (r = 0.338, p = 0.029) in melancholic MDD.

Conclusions

These findings confirmed the distinct dynamic functional pathway of hippocampal subregions in patients with melancholic MDD, and suggested that the dysfunction of hippocampus-cerebellum connectivity may be underlying the neural substrate of working memory impairment in melancholic MDD.
Robust control of robot manipulators with an adaptive fuzzy unmodelled parameter estimation law
Authors: Burkan Recep , Mutlu Askin
Published: December 2021

For robot manipulators, there are two types of disturbances. One is model parametric uncertainty; the other is unmodelled parameters such as joint friction forces and external disturbances. Unmodelled joint frictions and external disturbances reduce performance in terms of positioning accuracy and repeatability. In order to compensate for unmodelled parameters, the design of a new controller is considered. First, the modelled and unmodelled parameters are included in a dynamic model. Then, based on the dynamic model, a new Lyapunov function is developed. After that, new nonlinear joint friction and external disturbance estimation laws are derived as an analytic solution from the Lyapunov function; thus, the stability of the closed system is guaranteed. Better values of the adaptive dynamic compensators can be extracted by fuzzy rules according to the tracking error. Limitations and knowledge about friction and external disturbances are not required for the design of the controller. The controller compensates for all possible model parameter uncertainties, all possible unknown joint frictions and external disturbances.
Dramatic shift in the epidemiology of peptic ulcer in Japan: the impact of Helicobacter pylori eradication therapy
Authors: Lee K. D. , Kayano T. , Nishiura H.
Published: December 2021

Helicobacter pylori eradication therapy was included with insurance coverage from 1999 onwards in Japan, with the incidence of peptic ulcer expected to decrease as a consequence. This study investigated the temporal dynamics of peptic ulcer in Japan and identified underlying contributory factors using mathematical models. We investigated the seroprevalence of H. pylori and analysed a snapshot of peptic ulcer cases. Ten statistical models that incorporated important events – H. pylori infection, the cohort effect, eradication therapy and the natural trend for reduction – were fitted to the case data. The hazard of infection with H. pylori was extracted from published estimates. Models were compared using the Akaike information criterion (AIC), and factor contributions were quantified using the coefficient of determination. The best-fit model indicated that 88.1% of the observed snapshot of cases (AIC = 289.2) included the effects of (i) H. pylori infection, (ii) the cohort effect and (iii) eradication therapy, as explanatory variables, the contributions of which were 80.8%, 4.0% and 3.2%, respectively. Among inpatients, a simpler model with (i) H. pylori infection only was favoured (AIC = 107.7). The time-dependent epidemiological dynamics of peptic ulcers were captured and H. pylori infection and eradication therapy explained ⩾84% of the dramatic decline in peptic ulcer occurrence.
Accuracy of the Apple Watch single-lead ECG recordings in pre-term neonates
Authors: Paech Christian , Kobel Maria , Michaelis Anna , Gebauer Roman Antonin , Kalden Philipp , Dähnert Ingo , Thome Ulrich , Markel Franziska , Rützel Sebastian
Published: December 2021

Introduction:

Telemedicine gained an increasing use throughout the last years. Lifestyle tools like the Apple watch seem to have an increasing spread even in remote areas and underdeveloped regions. The increasing availability of these tools offers the chance to use the health care functions of these devices to improve provision of professional medical care. First data on the use of the Apple Watch as a remote monitoring device in children have been reported, showing good acceptability and usability of the Apple Watch for symptom monitoring in children. This study aimed to evaluate the accuracy of the Apple Watch iECG in comparison to a standard 12-lead ECG in pre-term babies.

Methods:

In this prospective, single-arm study, consecutive preterm neonates hospitalised in Leipzig University Hospital neonatal ICU were eligible. A 12-lead ECG and an iECG using Apple Watch 4 were performed. iECG and 12-lead ECG measurements were performed by a paediatric cardiologist. Cardiac rhythm was classified and amplitudes and timing intervals were analysed for comparability.

Results:

Fifty preterm neonates, gestational week (23–36 weeks), and body weight (0.65–3.09 kg) were enrolled. Overall good quality and excellent correlation of the Apple Watch generated iECG in comparison to the standard 12-lead ECG could be demonstrated (p < 0.001). When interpreted by a paediatric cardiologist, a correct rhythm classification could be done in 100% of cases.

Conclusion:

The Apple Watch iECG seems to be a valuable tool to record an ECG comparable to lead I of the standard 12-lead ECG even in pre-term neonates. With a widespread availability and excellent connectivity, the Apple Watch iECG function may provide practitioners with a tool to send an iECG for interpretation to a paediatric cardiac specialist.
Comparison of Standard Technique, Ultrasonography, and Near-Infrared Light in Difficult Peripheral Vascular Access: A Randomized Controlled Trial
Authors: Yalçınlı Sercan , Karbek Akarca Funda , Can Özge , Uz İlhan , Konakçı Gülbin
Published: December 2021

Objectives:

Successful placement of a peripheral intravenous catheter (PIVC) on the first attempt is an important outcome for difficult vascular access (DVA) patients. This study compared standard technique, ultrasonography (USG), and near-infrared light (NIR) in terms of success in the first attempt in patients with DVA.

Methods:

This was a prospective, randomized controlled study. The study was conducted in a tertiary care hospital. Emergency department patients who describe DVA history, have no visible or palpable veins, and were assessed by the nurse to have a difficult PIVC were included to study. The PIVC procedure was performed on patients by standard, USG, or NIR device techniques. For all approaches, the success of the first attempt was the primary aim. Total procedure time, the total number of attempts, and the need for rescue intervention were secondary aims.

Results:

This study evaluated 270 patients. The first attempt success rates for USG, standard, and NIR methods were 78.9%, 62.2%, and 58.9%, respectively. The rate of first attempt success was higher in patients who underwent USG (USG versus standard, P = .014; USG versus NIR, P = .004; standard versus NIR, P = .648). The total median (IQR) procedure time for USG, standard, and NIR methods was 107 (69-228), 72 (47-134), and 82 (61-163) seconds, respectively. The total procedure time was longer in patients undergoing USG (standard versus USG, P <.001; NIR versus USG, P = .035; standard versus NIR, P = .055). The total median (IQR) number of attempts of USG, standard, and NIR methods were 1 (1-1), 1 (1-2), and 1 (1-2), respectively. A difference was found among the groups regarding the total number of attempts (USG versus NIR, P = .015; USG versus standard P = .108; standard versus NIR, P = .307). No difference was found among groups in terms of the need for rescue methods.

Conclusion:

It was found that USG increases the success of the first attempt compared with the standard method and NIR in patients with DVA.
Identification of elite germplasm of medicinally important Andrographis paniculata (Burm. f.) Nees with high content of four active diterpenoids in aerial parts from wild populations of eastern India
Authors: Champati Bibhuti Bhusan , Padhiari Bhuban Mohan , Ray Asit , Jena Sudipta , Sahoo Ambika , Halder Tarun , Ghosh Biswajit , Kar Basudeba , Panda Pratap Chandra , Nayak Sanghamitra
Published: December 2021

Andrographis paniculata is an Indian medicinal plant with tremendous therapeutic values due to the presence of active diterpenoids in its aerial parts. However, high domestic and export demand has led to overexploitation of wild populations of this species. With a view to bringing A. paniculata into cultivation and to reduce the pressure on wild populations, the present study was undertaken to identify elite germplasm from different locations of eastern India by analysing intraspecific variation in the content of four major active diterpenoids. A total of 166 wild accessions of A. paniculata analysed through high-performance liquid chromatography (HPLC) revealed remarkable variation in the sum of four active diterpenoids in the aerial parts, ranging from 0.41 to 8.55% on a dry weight basis. Three elite accessions (AP-6, AP-8, AP-46) having respectively 8.02, 8.36 & 8.55% of the sum of four major active diterpenoids were identified. These germplasm could be used for commercial cultivation and genetic improvement of A. paniculata.
Stit-LOGIC FOR IMAGINATION EPISODES WITH VOLUNTARY INPUT
Authors: BADURA CHRISTOPHER , WANSING HEINRICH
Published: December 2021

Francesco Berto proposed a logic for imaginative episodes. The logic establishes certain (in)validities concerning episodic imagination. They are not all equally plausible as principles of episodic imagination. The logic also does not model that the initial input of an imaginative episode is deliberately chosen.Stit-imagination logic models the imagining agent’s deliberate choice of the content of their imagining. However, the logic does not model the episodic nature of imagination. The present paper combines the two logics, thereby modelling imaginative episodes with deliberately chosen initial input. We use a combination ofstit-imagination logic and a content-sensitive variably strict conditional à la Berto, for which we give a Chellas–Segerberg semantics. The proposed semantics has the following advantages over Berto’s: (i) we model thedeliberate choiceof initial input of imaginative episodes (in a multi-agent setting), (ii) we showframe correspondencesfor axiomatic analogues of Berto’s validities, which (iii) allows thepossibility to disregard axiomsthat might be considered not plausible as principles concerning imaginative episodes. We do not take a definite stance on whether theseshouldbe disregarded but give reasons for why one might want to disregard them. Finally, we compare our semantics briefly with recent work, which aims to model voluntary imagination, and argue that our semantics models different aspects.
Dual-band ambient energy harvesting systems based on metamaterials for self-powered indoorwireless sensor nodes
Authors: Le Minh Thuy , Ngo Van Duc , Nguyen Thanh Tung , Nguyen Quoc Cuong
Published: December 2021

In this study, we present a comprehensive dual-band ambient radio-frequency (RF) energy harvesting system, consisting of rectenna and power management circuit, to harvest energy from 2.45 and 5.8 GHz Wi-Fi. The rectenna employs a metamaterial antenna based on a split-ring resonator, which possesses omni-directional radiation pattern at both frequencies and compact size (0.18λ × 0.25λ at 2.45 GHz). The dual-band rectifier yields the highest efficiency of 42% at 2.45 GHz and 1 dBm input power, 30% at 5.8 GHz and − 7 dBm input power. The maximum RF-DC efficiency for each band is 72% at − 5 dBm and 27% at − 2 dBm, respectively. The power management circuit, consisting of a storing capacitor and a boost converter, is integrated to produce a stable, sufficient output voltage. The energy harvesting system, with its comprehensiveness, is suitable for supplying low-power wireless sensor nodes for indoor applications.
Measurement Invariance of Two Different Short Forms of Social	Interaction Anxiety Scale (SIAS) and Social Phobia Scale (SPS) in Chinese and US	Samples
Authors: Zhong Jiayi , Liu Junsheng , Xu Gangmin , Zheng Hong , Bowker Julie , Coplan Robert J.
Published: December 2021

Abstract. The goal of this study was to examine the measurement invariance of two different commonly used short forms of the Social Interaction Anxiety Scale (SIAS) and the Social Phobia Scale (SPS) across Chinese and US samples. Participants were 850 (52% females) Chinese and 399 (57% females) US undergraduate students. A two-factor model was identified as the best fitting baseline model for both short-forms of the SIAS and SPS. Full scalar invariance was established for the Peters short form, whereas the Fergus short form only achieved partial scalar invariance. Results of structured means analysis indicated that Chinese participants scored higher than US participants in social anxiety. Some cultural implications for the use of these two sets of short forms are discussed.
A Global Map of Human Sewage in Coastal Ecosystems
Authors: Kornei Katherine
Published: December 2021

Prodigious quantities of nitrogen from human waste flow into coastal waters, a study of nearly 135,000 watersheds reveals.
Risk of Heat‐Related Mortality, Disease, Accident, and Injury Among Korean Workers: A National Representative Study From 2002 to 2015
Authors: Yoon Jin‐Ha , Lee Won‐Tae , Yoon Min Joo , Lee Wanhyung
Published: December 2021

Many studies have shown that heat waves can cause both death and disease. Considering the adverse health effects of heat waves on vulnerable groups, this study highlights their impact on workers. The present study thus investigated the association between heat exposure and the likelihood of hospitalization and death, and further identified the risk of heat‐related diseases or death according to types of heat and dose‐response modeling with heat threshold. Workers were selected from the Korean National Health Insurance Service‐National Sample Cohort 2002–2015, and regional data measured by the Korea Meteorological Administration were used for weather information. The relationship between hospitalization attributable to disease and weather variables was analyzed by applying a generalized additional model. Using the Akaike information criterion, we selected a model that presented the optimal threshold. Maximum daily temperature (MaxT) was associated with an increased risk of death and outdoor mortality. The association between death outdoors and MaxT had a threshold of 31.2°C with a day zero lag effect. History of medical facility visits due to the health effects of heat waves was evident in certain infectious and parasitic diseases (A and B), cardio and cerebrovascular diseases (I20–25 and I60–69), injury, poisoning, and other consequences of external causes (S, T). The study demonstrated that heat exposure is a risk factor for death and infectious, cardio‐cerebrovascular, and genitourinary diseases, as well as injuries or accidents among workers. The finding that heat exposure affects workers' health has future implications for decision makers and researchers.
CMIP6 Models Underestimate the Holton‐Tan Effect
Authors: Elsbury Dillon , Peings Yannick , Magnusdottir Gudrun
Published: December 2021

The teleconnection between the Quasi‐Biennial Oscillation (QBO) and the Arctic polar vortex is investigated using Coupled Model Intercomparison Project 6 (CMIP6) models. Output from 14 CMIP6 models is compared with reanalysis, three experiments with prescribed QBOs, one of which has no free polar stratospheric variability, and transient experiments in which a QBO is prescribed in runs previously devoid of a QBO. Each CMIP6 model underestimates the Holton‐Tan effect (HTE), the weakening of the polar vortex expected with QBO easterlies in the tropical lower stratosphere. To establish why, potential vorticity maps are used to investigate longitudinal variations in the teleconnection. Prescribing easterly QBO in the transient experiments promotes more high‐latitude planetary wave breaking by influencing the mid‐latitude stratospheric circulation, particularly over Asia. CMIP6 models that better simulate this response over Asia better simulate the HTE. These models also have stronger 10 hPa QBO westerlies.
Observation and Fully Thermal Simulation of Quasi‐Electrostatic Magnetosonic Waves
Authors: Gao Zhonglei , Liu Si , Xiao Fuliang , Zhou Qinghua , He Qian , Li Tong , Shang Xiongjun , Yang Chang , Zhang Sai , Yang Qiwu
Published: December 2021

Magnetosonic (MS) waves are generally considered as electromagnetic harmonic fluctuations below the lower hybrid frequency. Here we present a correlated observation of proton ring‐like distribution and low harmonic magnetosonic waves with undetectable magnetic components (called QEMS). We conduct fully thermal simulations (WHAMP) to investigate the wave properties. The calculated growth rates can reproduce the observed spectral characteristics and demonstrate that the QEMS waves are excited as ion Bernstein modes by proton ring‐like distribution. The ratios between the wave electric and magnetic amplitudes E/B given by WHAMP indicate that the magnetic spectral densities are below the instrument noise level, and the ratios are ∼7–80 times larger than the wave phase speeds Vph, suggesting that the QEMS waves are essentially quasi‐electrostatic, not just visually quasi‐electrostatic due to the measurement limit. This study provides further insights into the QEMS natures.
Ongoing Drainage Reorganization Driven by Rapid Lake Growths on the Tibetan Plateau
Authors: Liu Kai , Ke Linghong , Wang Jida , Jiang Ling , Richards Keith S. , Sheng Yongwei , Zhu Yunqiang , Fan Chenyu , Zhan Pengfei , Luo Shuangxiao , Cheng Jian , Chen Tan , Ma Ronghua , Liang Qiuhua , Madson Austin , Song Chunqiao
Published: December 2021

Drainage reorganization generally occurs on geological time scales under unstable river network conditions. A few local‐scale studies indicate that recent climatic changes might accelerate the drainage reorganization process. However, large‐scale drainage reorganization during the modern era is rarely documented. This study examines ongoing drainage reorganization on the endorheic Tibetan Plateau (TP) as a primary result of drastic lake expansion. A total of 11 drainage system reorganization events comprising 24 different lake basins and covering a total area of 61,115 km2 occurred between 2000 and 2018. Assuming the continued growth rate of TP lakes, we project another 20 basins will be reorganized before 2030. These drainage basin reorganizations not only alter hydrological processes in the endorheic TP but may also cause the endorheic‐exorheic transition, leading to the upstream sprawl of the Yangtze River Basin and posing outburst flooding risks on China's key infrastructure such as the Qinghai‐Tibet Railway.
An Approach to Empirical Mapping of Incoherent Internal Tides With Altimetry Data
Authors: Egbert G. D. , Erofeeva S. Y.
Published: December 2021

Much of the internal tide (IT) is coherent with tidal forcing, but interactions with time‐varying ocean flows result in an incoherent component of IT (IIT), which will complicate interpretation of data from the upcoming Surface Water Ocean Topography (SWOT) mission. Here, we demonstrate a simple scheme for estimation of these IIT. We use a short‐time harmonic analysis of outputs of a wind‐ and tidally forced ocean model to generate an ensemble of IT variations in an ocean patch. Principal Components Analysis is used to define the dominant spatial patterns, and combined with sinusoidal time variations at tidal frequencies to define spatio‐temporal basis functions that are used to fit sparse altimetry data available in short time windows. The scheme is illustrated using a 1‐yr Hybrid Coordinate Ocean Model (HYCOM) run off the Amazon Shelf. Tests with synthetic (SWOT) and real (nadir altimetry) data demonstrate that a significant fraction of IIT can be recovered with this procedure.
Finite‐Size Analysis of the Collapse of Dry Granular Columns
Authors: Man Teng , Huppert Herbert E. , Li Ling , Galindo‐Torres Sergio A.
Published: December 2021

In this letter, we focus on the size effect of granular column collapses, which are potentially connected to the dynamics of complex geophysical flows, even if the link between microscopic structures of granular assemblies and their macroscopic behaviors is still not well understood. Using the spheropolyhedral discrete element method (DEM), we show that the column radius/grain size ratio has a strong influence on the collapse behavior. A finite‐size analysis, which is inspired by a phase transition around an inflection point, is performed to obtain a general scaling equation with critical exponents for runout distances. We further link the size effect with the strong force network and formalize a correlation length scale that exponentially scales with the effective aspect ratio. Such a scaling solution shows similarities with the percolation problem of two‐dimensional random networks and can be extended to other similar natural and engineering systems.
The Mechanisms of Cloudiness Evolution Responsible for Equilibrium Climate Sensitivity in Climate Model INM‐CM4‐8
Authors: Volodin E.
Published: December 2021

Current climate models demonstrate large discrepancy in equilibrium climate sensitivity (ECS). The effects of cloudiness parameterization changes on the ECS of the INM‐CM4‐8 climate model were investigated. This model shows the lowest ECS among CMIP6 models. Reasonable changes in the parameterization of the degree of cloudiness yielded ECS variability of 1.8–4.1 K in INM‐CM4‐8, which was more than half of the interval for the CMIP6 models. The three principal mechanisms responsible for the increased ECS were increased cloudiness dissipation in warmer climates due to the increased water vapor deficit in the non‐cloud fraction of a cell, decreased cloudiness generation in the atmospheric boundary layer in warm climates, and the instantaneous cloud response to CO2 increases due to stratification changes.
Meridional Migration of ENSO Impact on Tropical Atlantic Precipitation Controlled by the Seasonal Cycle
Authors: Jiang Feng , Zhang Wenjun , Jin Fei‐Fei , Stuecker Malte F.
Published: December 2021

Previous studies suggest that the El Niño–Southern Oscillation (ENSO) impact on tropical Atlantic climate variability shows strong seasonal preference, manifesting itself primarily in the decaying boreal spring season. However, here we show that a robust ENSO signal in tropical Atlantic precipitation anomalies can be detected throughout ENSO’s whole lifecycle. We find that the ENSO impact on the tropical Atlantic precipitation migrates meridionally, following the seasonal migration of the Atlantic Intertropical Convergence Zone (ITCZ). Taking into account the modulation of the local seasonal cycle, the full spatiotemporal characteristics of ENSO’s impact on tropical Atlantic precipitation are uncovered. Furthermore, we demonstrate that climate models can simulate the modulation of ENSO‐related precipitation over the tropical Atlantic by the local seasonal cycle despite the substantial mean state model bias in the Atlantic ITCZ. This extended perspective on ENSO’s impact on tropical Atlantic climate variability enhances prospects for skillful year‐round regional climate prediction.
Propagation of Chorus Waves Generated in Minimum‐B Pockets
Authors: Kang Ning , Bortnik Jacob , An Xin , Claudepierre Seth G.
Published: December 2021

We present the first ray tracing results of chorus waves generated in minimum‐B pockets. A new ray tracer is developed to accommodate an arbitrary magnetic field model, which enables us to construct minimum‐B pocket geometries using the Tsyganenko (1989) model. Rays with different frequencies and initial wave normal angles are launched from minimum‐B pockets and traced under different geomagnetic activity and hot electron density conditions. Our results indicate that chorus waves generated from minimum‐B pockets are usually highly localized and thus are unlikely to be detected unless the spacecraft is very close to the source region. These waves are also very unlikely to propagate into the plasmasphere. The propagation distances generally decrease with increasing geomagnetic activity.
Crystallographic Preferred Orientation (CPO) Development Governs Strain Weakening in Ice: Insights From High‐Temperature Deformation Experiments
Authors: Fan Sheng , Cross Andrew J. , Prior David J. , Goldsby David L. , Hager Travis F. , Negrini Marianne , Qi Chao
Published: December 2021

Strain weakening leads to the formation of high‐strain shear zones and strongly influences terrestrial ice discharge. In glacial flow models, strain weakening is assumed to arise from the alignment of weak basal planes—the development of a crystallographic preferred orientation, CPO—during flow. However, in experiments, ice strain weakening also coincides with grain size reduction, which has been invoked as a weakening mechanism in other minerals. To interrogate the relative contributions of CPO development and grain size reduction toward ice strain weakening, we deformed initially isotropic polycrystalline ice samples to progressively higher strains between −4 and −30°C. Microstructural measurements were subsequently combined with flow laws to separately model the mechanical response expected to arise from CPO development and grain size reduction. Magnitudes of strain weakening predicted by the constitutive flow laws were then compared with the experimental measurements. Flow laws that only consider grain size do not predict weakening with strain despite grain size reduction. In contrast, flow laws solely considering CPO effects can reproduce the measured strain weakening. Thus, it is reasonable to assume that strain weakening in ice is dominated by CPO development, at least under high temperature ( ≥ 0.9) and high stress (>1 MPa), like those in our experiments. We speculate that at high homologous temperatures ( ≥ 0.9), CPO development will also govern the strain weakening behavior of other viscously anisotropic minerals, like olivine and quartz. Overall, we emphasize that geodynamic and glaciological models should incorporate CPOs to account for strain weakening, especially at high homologous temperatures.
Modeling the Morphodynamic Response of Estuarine Intertidal Shoals to Sea‐Level Rise
Authors: Elmilady H. , van der Wegen M. , Roelvink D. , van der Spek A.
Published: December 2021

Intertidal shoals are key features of estuarine environments worldwide. Climate change poses questions regarding the sustainability of intertidal areas under sea‐level rise (SLR). Our work investigates the SLR impact on the long‐term morphological evolution of unvegetated intertidal sandy shoals in a constrained channel‐shoal system. Utilizing a process‐based model (Delft3D), we schematize a short tidal system in a rectangular (2.5 × 20 km) basin with a high‐resolution grid. An initial, mildly sloping, bathymetry is subjected to constant semidiurnal tidal forcing, sediment supply, and small wind‐generated waves modeled by SWAN. A positive morphodynamic feedback between hydrodynamics, sediment transport, and morphology causes the emergence of large‐scale channel‐shoal patterns. Over centuries, tide‐residual sediment transport gradually decreases leading to a state of low morphological activity balanced by tides, waves, and sediment supply. Tidal currents are the main driver of the SLR morphodynamic adaptation. Wave action leads to wider and lower shoals but does not fundamentally change the long‐term morphological evolution. SLR causes increased flood dominance which triggers sediment import into the system. Shoals accrete in response to SLR with a lag that increases as SLR accelerates, eventually causing intertidal shoals to drown. Seaward shoals near the open boundary sediment source have higher accretion rates compared to landward shoals. Similarly, on a shoal‐scale, the highest accretion rates occur at the shoal edges bounding the sediment suppling channels. A larger sediment supply enhances the SLR adaptation. Waves help distribute sediment supplied from channels across shoals. Adding mud fractions leads to faster, more uniform, accretion and muddier shoals under SLR.
Identification of Debris‐Flow Channels Using High‐Resolution Topographic Data: A Case Study in the Quebrada del Toro, NW Argentina
Authors: Mueting A. , Bookhagen B. , Strecker M. R.
Published: December 2021

Resolving Earth's surface at the meter scale is essential for an improved understanding of the dynamics of mass‐movement processes. In this study, we explore the applicability and potential of digital elevation models (DEMs) derived from stereophotogrammetry to detect debris‐flow channels in the Quebrada del Toro in the northwestern Argentine Andes. Our analysis relies on a high‐resolution (3 m) DEM created from SPOT‐7 tri‐stereo satellite data. We carefully validated DEM quality with ∼6,000 differential GPS points and identified optimal parameters for DEM generation in high‐relief terrain. After multiple processing steps, we achieved an accuracy of 0.051 ± 1.915 m (1σ) using n = 3,139 control points with cm precision. Previous studies have used the drainage area and slope framework to identify topographic signatures of debris flows within a catchment. We built upon this and investigated individual river‐channel segments using connected‐component (CC) analysis on meter‐scale topographic data. We define CC as segments of similar slope along the channel profile. Based on seven manually identified debris‐flow catchments, we developed a debris‐flow similarity index using component length and mean channel‐segment slope and identified channel segments that have likely been shaped by debris flows. The presented approach has the potential to resolve intra‐catchment variability of transport processes, allows to constrain the extent of debris‐flow channels more precisely than slope‐area analysis, and highlights the versatility of combined space‐ and field‐based observations for natural‐hazard assessments.
Seasonal Changes of Organic Carbon Mixing, Degradation and Deposition in Yangtze River Dominated Margin Related to Intrinsic Molecular and External Environmental Factors
Authors: Han Lulu , Wang Yinghui , Xiao Wenjie , Wu Jianqiang , Guo Lixia , Wang Yasong , Ge Huangmin , Xu Yunping
Published: December 2021

The East Asian monsoon is characterized by warm, humid summer and cool, dry winter that results in seasonal changes in fluvial sediment and organic carbon (OC) discharge. Here, we report measurements of elemental, isotopic, and optical compositions of OC in surface waters and sediments that were collected along the lower Yangtze River, Estuary, and East China Sea continuum in March and July 2019. The principal component analysis separates samples into three groups that correspond to fresh water area, mixing area, and seawater area. The terrigenous signal in the mixing area, indicated by water salinity and δ13C, is stronger in July. The applications of binary mixing models based on water salinity, dissolved OC (DOC) concentration and specific terrigenous fluorescence component suggest: (a) net removal of DOC from waters in July, but net addition of DOC into waters in March, attributed to more extensive degradation and larger deposition of OC in summer; and (b) more conservative behaviors of terrigenous OC compared to marine or mixed OC, suggesting an important role of intrinsic molecular characteristics on the persistence of DOC. The estimated monthly OC burial flux in the estuary and continent shelf is 0.48 × 1012 g in July and 0.081 × 1012 g of OC in March, equal to 15.5% and 2.6% of the annual OC discharge by the Yangtze River, respectively. Our study suggests that the burial of OC mainly occurs in the summer monsoon due to the larger sediment load of the Yangtze River, prevailing southeastern wind, and intensified Kuroshio Current.
Sensitivity of Convection Permitting Simulations to Lateral Boundary Conditions in Idealized Experiments
Authors: Ahrens Bodo , Leps Nora
Published: December 2021

Limited‐area convection‐permitting climate models (CPMs) with horizontal grid‐spacing less than 4 km and not relying on deep convection parameterisations (CPs) are being used more and more frequently. CPMs represent small‐scale features such as deep convection more realistically than coarser regional climate models (RCMs) with deep CPs. Because of computational costs, CPMs tend to use smaller horizontal domains than RCMs. As all limited‐area models (LAMs), CPMs suffer issues with lateral boundary conditions (LBCs) and nesting. We investigated these issues using idealized Big‐Brother (BB) experiments with the LAM COSMO‐CLM. Grid‐spacing of the reference BB simulation was 2.4 km. Deep convection was triggered by idealized hills with driving data from simulations with different spatial resolutions, with/without deep CP, and with different nesting frequencies and LBC formulations. All our nested idealized 2.4‐km Little‐Brother (LB) experiments performed worse than a coarser CPM simulation (4.9 km) which used a four times larger computational domain and yet spent only half the computational cost. A boundary zone of grid‐points of the LBs could not be interpreted meteorologically because of spin‐up of convection and boundary inconsistencies. Hosts with grid‐spacing in the so‐called gray zone of convection (ca. 4–20 km) were not advantageous to the LB performance. The LB's performance was insensitive to the applied LBC formulation and updating (if ‐hourly). Therefore, our idealized experiments suggested to opt for a larger domain instead of a higher resolution even if coarser than usual ( km) as a compromise between the harmful boundary problems, computational cost and improved representation of processes by CPMs.
Ecosystem Photosynthesis in Land‐Surface Models: A First‐Principles Approach Incorporating Acclimation
Authors: Mengoli Giulia , Agustí‐Panareda Anna , Boussetta Souhail , Harrison Sandy P. , Trotta Carlo , Prentice I. Colin
Published: December 2021

Vegetation regulates land‐atmosphere, water, and energy exchanges and is an essential component of land‐surface models (LSMs). However, LSMs have been handicapped by assumptions that equate acclimated photosynthetic responses to the environment with the fast responses observable in the laboratory. The effects of acclimation can be taken into account by including PFT‐specific values of photosynthetic parameters, but at the cost of increasing parameter requirements. Here, we develop an alternative approach for including acclimation in LSMs by adopting the P model, an existing light‐use efficiency model for gross primary production (GPP) that implicitly predicts the acclimation of photosynthetic parameters on a weekly to monthly timescale via optimality principles. We demonstrate that it is possible to explicitly separate the fast and slow photosynthetic responses to environmental conditions, allowing the simulation of GPP at the sub‐daily timesteps required for coupling in an LSM. The resulting model reproduces the diurnal cycles of GPP recorded by eddy‐covariance flux towers in a temperate grassland and boreal, temperate and tropical forests. The best performance is achieved when biochemical capacities are adjusted to match recent midday conditions. Comparison between this model and the operational LSM in the European Centre for Medium‐range Weather Forecasts climate model shows that the new model has better predictive power in most of the sites and years analyzed, particularly in summer and autumn. Our analyses suggest a simple and parameter‐sparse method to include both instantaneous and acclimated responses within an LSM framework, with potential applications in weather, climate, and carbon‐cycle modeling.
On Use of Low Cost, Compact GNSS Receiver Modules for Ionosphere Monitoring
Authors: Dan Sukabya , Santra Atanu , Mahato Somnath , Koley Chaitali , Banerjee P. , Bose Anindya
Published: December 2021

Geodetic or special purpose Global Navigation Satellite System (GNSS) receivers are used for ionosphere monitoring and research. Dual frequency, compact, low‐cost commercial GNSS modules can provide raw GNSS data and are commonly used for positioning applications. This paper presents the applicability of these compact modules for monitoring ionospheric activities. A comparative study between Javad Triumph LS, a costly geodetic receiver, and an Ublox ZED‐F9P, a low‐cost, dual‐frequency, compact module is carried out to explore the potential of the low‐cost devices for ionosphere probing. Studies are carried out on signal strength values (C/N0) and vertical total electron content (VTEC) values. From the concurrently collected GPS data, a bias of 2.2–4.9 dBHz in signal strength values are observed between the two types of receivers depending on the signal frequency band. The VTEC values calculated from the Ublox module are in close agreement with the values obtained from the Triumph LS receiver. Therefore, the compact module shows the potential for use in ionosphere monitoring with clear advantages in cost, size, and power consumption. However, the signal strength values obtained from such compact modules need to be calibrated using standard GNSS receivers. A GNSS‐based Ionosphere Monitoring Unit (GIMU) is also proposed in this manuscript by the integration of a compact, low‐cost GNSS module with a single‐board computer and a wireless data communication module. Real‐time, cost‐effective, concurrent ionosphere monitoring over a geographically distributed network is possible using a network of such units.
Radiation Belt Model Including Semi‐Annual Variation and Solar Driving (Sentinel)
Authors: Katsavrias C. , Aminalragia‐Giamini S. , Papadimitriou C. , Daglis I. A. , Sandberg I. , Jiggens P.
Published: December 2021

The Earth's outer radiation belt response to geospace disturbances is extremely variable spanning from a few hours to several months. In addition, the numerous physical mechanisms, which control this response depend on the electron energy, the timescale, and the various types of geospace disturbances. As a consequence, various models that currently exist are either specialized, orbit‐specific data‐driven models, or sophisticated physics‐based ones. In this paper, we present a new approach for radiation belt modeling using Machine Learning methods driven solely by Solar wind speed and pressure, Solar flux at 10.7 cm, and the angle controlling the Russell‐McPherron effect (θRM). We show that the model can successfully reproduce and predict the electron fluxes of the outer radiation belt in a broad energy (0.033–4.062 MeV) and L‐shell (2.5–5.9) range, and moreover, it can capture the long‐term modulation of the semi‐annual variation. We also show that the model can generalize well and provide successful predictions, even outside of the spatio‐temporal range it has been trained with, using 0.8 MeV electron flux measurements from GOES‐15/EPEAD at a geostationary orbit.
The Relationship Between Delta Form and Nitrate Retention Revealed by Numerical Modeling Experiments
Authors: Knights Deon , Sawyer Audrey H. , Edmonds Douglas A. , Olliver Elizabeth A. , Barnes Rebecca T.
Published: December 2021

River deltas display a wide range of morphologic patterns that influence how nutrients interact in channels and wetlands on their way to the coast. To quantify the role of delta morphology on nitrate fate, we simulated reactive nitrate transport over steady base flow conditions for six synthetic, morphologically unique river‐dominated deltas created in Delft3D by varying incoming grain size distributions. We parameterized nitrate removal kinetics using an observed relationship with elevation from Wax Lake Delta (Louisiana, USA). Total nitrate retention across the six synthetic deltas and Wax Lake Delta ranged from 1.3%‐13%, suggesting that these river‐dominated deltas have limited ability to remove nitrate from incoming river water. Nitrate removal is constrained by limited hydrologic connectivity with the areas of greatest nitrate demand, which are found at higher elevation. In these synthetic numerical experiments, the efficiency of nitrate removal is greatest for deltas with more topologic complexity and greater proportions of the delta plain at higher elevation, which are both common characteristics of coarser‐grained deltas. The positive relationship between grain size and nitrate removal may help guide land reclamation projects if project goals include minimizing nitrate export to the sea.
Antibiotics in critically ill children—a narrative review on different aspects of a rational approach
Authors: Bruns Nora , Dohna-Schwake Christian
Published: December 2021

Especially critically ill children are exposed to antibiotic overtreatment, mainly caused by the fear of missing out a severe bacterial infection. Potential adverse effects and selection of multi-drug resistant bacteria play minor roles in decision making. This narrative review first describes harm from antibiotics and second focuses on different aspects that could help to reduce antibiotic overtreatment without harming the patient: harm from antibiotic treatment, diagnostic approaches, role of biomarkers, timing of antibiotic therapy, empiric therapy, targeted therapy, and therapeutic drug monitoring. Wherever possible, we linked the described evidence to the current Surviving Sepsis Campaign guidelines. Antibiotic stewardship programs should help guiding antibiotic therapy for critically ill children.

Impact

Critically ill children can be harmed by inadequate or overuse of antibiotics.

Hemodynamically unstable children with a suspicion of infection should be immediately treated with broad-spectrum antibiotics. In contrast, in hemodynamically stable children with sepsis and organ dysfunction, a time frame of 3 h for proper diagnostics may be adequate before starting antibiotics if necessary.

Less and more targeted antibiotic treatment can be achieved via antibiotic stewardship programs.
Genetically regulated expression in late-onset Alzheimer’s disease implicates risk genes within known and novel loci
Authors: Chen Hung-Hsin , Petty Lauren E. , Sha Jin , Zhao Yi , Kuzma Amanda , Valladares Otto ,   Alzheimer’s Disease Genetics Consortium, International Genomics of Alzheimer’s Project, Bush William , Naj Adam C. , Gamazon Eric R. , Below Jennifer E.
Published: December 2021

Late-onset Alzheimer disease (LOAD) is highly polygenic, with a heritability estimated between 40 and 80%, yet risk variants identified in genome-wide studies explain only ~8% of phenotypic variance. Due to its increased power and interpretability, genetically regulated expression (GReX) analysis is an emerging approach to investigate the genetic mechanisms of complex diseases. Here, we conducted GReX analysis within and across 51 tissues on 39 LOAD GWAS data sets comprising 58,713 cases and controls from the Alzheimer’s Disease Genetics Consortium (ADGC) and the International Genomics of Alzheimer’s Project (IGAP). Meta-analysis across studies identified 216 unique significant genes, including 72 with no previously reported LOAD GWAS associations. Cross-brain-tissue and cross-GTEx models revealed eight additional genes significantly associated with LOAD. Conditional analysis of previously reported loci using established LOAD-risk variants identified eight genes reaching genome-wide significance independent of known signals. Moreover, the proportion of SNP-based heritability is highly enriched in genes identified by GReX analysis. In summary, GReX-based meta-analysis in LOAD identifies 216 genes (including 72 novel genes), illuminating the role of gene regulatory models in LOAD.