bluuebunny/crossref_metadata_2025 huggingface dataset:
A 4GS/s 8‐bit time‐interleaved SAR ADC with an energy‐efficient architecture in 130 nm CMOS
Authors: Solis Fredy , Fernández Bocco Álvaro , Galetto Agustín C. , Passetti Leandro , Hueda Mario R. , Reyes Benjamín T.
Published: May 2021

This paper presents the design, implementation, and measurements of a 4 GS/s, 8‐bit resolution, time‐interleaved (TI) analog‐to‐digital converter (ADC) comprised of 32 asynchronous successive approximation register (SAR) ADCs. The chip is fabricated in a 130 nm CMOS process. This prototype achieves the highest sampling rate and the best efficiency for a SAR TI‐ADC in the process used. An energy‐efficient hierarchical T&H architecture, ranked in a 4 × 8 structure, has been used to interleave the aforementioned high number of SAR ADCs avoiding the power hungry buffers typically used in the input signal path and/or T&H outputs. The sampling architecture includes programmable delay cells with up to 104 fs resolution to calibrate sampling time errors. Additionally, the input matching network uses an on‐chip inductance to mitigate the impact of the packaging on the analog bandwidth. An efficient SAR ADC implementation is achieved by an optimized comparator design, which allows for both, noise and asynchronous clock control, and includes background DC offset calibration. The test chip is the core of a measurement platform dedicated to the evaluation of mismatch calibration techniques for ADCs used in high speed digital communication systems. To enable this application, a 32Gb/s low‐voltage differential signaling interface is included to transmit the samples off‐chip without any decimation. The TI‐ADC achieves a peak 7.09 effective number of bits (ENOB) (5.47ENOB at Nyquist) and 1.3 GHz input bandwidth with a power consumption of 93 mW at 1.2 V. Each SAR ADC channel achieves a Walden figure of merit (FOM) of 123fJ/conv‐step and owing to the efficient interleaved architecture the full TI‐ADC achieves a peak FOM of 171fJ/conv‐step (526fJ/conv‐step at Nyquist).
Channel estimation and secure data transmission using hybrid particle swarm optimisation–gray wolf optimisation‐leaky least‐Mean‐Square and affine elliptic curves cryptography algorithm in MU‐multi‐input multi‐output orthogonal frequency division multiplexing system
Authors: R Jeya , Amutha B.
Published: May 2021

In a huge multi‐input multi‐output orthogonal frequency divisions multiplexing (MIMO‐OFDM), an exact Channel State Information (CSI) is required to understand the system performance, which includes high spectrum together with energy efficiency. Using the OFDM, substantial numbers of pilots are distributed over a huge range of time–frequency sources to efficiently assess a vast range of channel coefficients in space along with the frequency domains, forfeiting spectral efficiency. Here, an optimised Channel Estimation (CE) framework aimed at the MU‐MIMO OFDM system is proposed utilising Hybrid Particle Swarm Optimisation–Gray Wolf Optimisation‐Leaky Least‐Mean‐Square (HPG‐LLMS) to attain high accurateness and secure data transmission (DT) with the aid of proposed Affine ECC. Herein, the video is considered as an input in the transmitter side and transformed into data frames and compressed with the help of ASCII‐based Huffman algorithm. Using Affine ECC, the compressed data are encrypted as well as modulated with the help of the MQPSK method. Then, transmute the modulated data into IFFT and incorporate the Guard Interval (GI) to the data. And then, over the Multi‐Path Channel (MPC), the symbols will be passed on to the receiver with the Additives White Gaussian Noise (AWGN). Execute the Inverse operations on the receiver side and centred on fuzzy centred priority scheduling algorithm (FPSA), sent the data to the user. Lastly, utilising HPG‐LLMS, the CE is performed.
Optimizing bat bioacoustic surveys in human‐modified Neotropical landscapes
Authors: López‐Baucells Adrià , Yoh Natalie , Rocha Ricardo , Bobrowiec Paulo E. D. , Palmeirim Jorge M. , Meyer Christoph F. J.
Published: May 2021

During the last decades, the use of bioacoustics as a non‐invasive and cost‐effective sampling method has greatly increased worldwide. For bats, acoustic surveys have long been known to complement traditional mist‐netting, however, appropriate protocol guidelines are still lacking for tropical regions. Establishing the minimum sampling effort needed to detect ecological changes in bat assemblages (e.g., activity, composition, and richness) is crucial in view of workload and project cost constraints, and because detecting such changes must be reliable enough to support effective conservation management. Using one of the most comprehensive tropical bat acoustic data sets, collected in the Amazon, we assessed the minimum survey effort required to accurately assess the completeness of assemblage inventories and habitat selection in fragmented forest landscapes for aerial insectivorous bats. We evaluated a combination of 20 different temporal sampling schemes, which differed regarding number of hours per night, number of nights per site, and sampling only during the wet or dry season, or both. This was assessed under two different landscape scenarios: in primary forest fragments embedded in a matrix of secondary forest and in the same forest fragments, but after they had been re‐isolated through clearing of the secondary forest. We found that the sampling effort required to achieve 90% inventory completeness varied considerably depending on the research aim and the landscape scenario evaluated, averaging ~80 and 10 nights before and after fragment re‐isolation, respectively. Recording for more than 4 h per night did not result in a substantial reduction in the required number of sampling nights. Regarding the effects of habitat selection, except for assemblage composition, bat responses in terms of richness, diversity, and activity were similar across all sampling schemes after fragment re‐isolation. However, before re‐isolation, a minimum of four to six sampling hours per night after dusk and three to five nights of sampling per site were needed to detect significant effects that could otherwise go unnoticed. Based on our results, we propose guidelines that will aid to optimize sampling protocols for bat acoustic surveys in the Neotropics.
Effect of scavenging on predation in a food web
Authors: Mellard Jarad P. , Hamel Sandra , Henden John‐André , Ims Rolf A. , Stien Audun , Yoccoz Nigel
Published: May 2021

Scavenging can have important consequences for food web dynamics, for example, it may support additional consumer species and affect predation on live prey. Still, few food web models include scavenging. We develop a dynamic model that includes two facultative scavenger species, which we refer to as the predator or scavenger species according to their natural scavenging propensity, as well as live prey, and a carrion pool to show ramifications of scavenging for predation in simple food webs. Our modeling suggests that the presence of scavengers can both increase and decrease predator kill rates and overall predation in model food webs and the impact varies (in magnitude and direction) with context. In particular, we explore the impact of the amount of dynamics (exploitative competition) allowed in the predator, scavenger, and prey populations as well as the direction and magnitude of interference competition between predators and scavengers. One fundamental prediction is that scavengers most likely increase predator kill rates, especially if there are exploitative feedback effects on the prey or carrion resources like is normally observed in natural systems. Scavengers only have minimal effects on predator kill rate when predator, scavenger, and prey abundances are kept constant by management. In such controlled systems, interference competition can greatly affect the interactions in contrast to more natural systems, with an increase in interference competition leading to a decrease in predator kill rate. Our study adds to studies that show that the presence of predators affects scavenger behavior, vital rates, and food web structure, by showing that scavengers impact predator kill rates through multiple mechanisms, and therefore indicating that scavenging and predation patterns are tightly intertwined. We provide a road map to the different theoretical outcomes and their support from different empirical studies on vertebrate guilds to provide guidance in wildlife management.
Cooperation behavior of fore‐ And hindlimbs during jumping in Rana dybowskii and Xenopus laevis
Authors: Li Mo , Gao Zibo , Wang Jili , Song Wei , Zhang Qingzhu , Tong Jin , Ren Lili
Published: May 2021

Frogs are characterized by their outstanding jumping ability, depending on the rapid extension of hindlimbs to propel their bodies into air. A typical jumping cycle could be broken into four phases: preparation, takeoff, flight, and landing. Considerable research has been performed to discuss the function of hindlimbs of frogs during takeoff phase, whereas the literature of limbs' motion in jumping between different species was limited. To profile the evolution of locomotion in anurans, it is necessary to investigate on the motion of fore‐ and hindlimbs of frogs within different taxa. In this work, we put forward a detailed description of jumping behavior of two frog species, Rana dybowskii and Xenopus laevis. High‐speed cameras were used to explore the movement of different joints in fore‐ and hindlimbs of these two animals, and kinematic analysis was operated to identify both homologous behaviors and significant differences between them. We found that the Rana dybowskii's fore‐ and hindlimbs had good cooperation during jumping, while the Xenopus laevis' uncooperative behavior in limbs may give a functional explanation for the deficiency in terrestrial jumping; besides, the R. dybowskii's landing followed the “hands‐belly‐feet slap” strategy, and Xenopus laevis had clumsy landing with “belly‐flops” sequence. The result gained here clarifies the cooperation behavior of anuran limbs and may supply a new insight into our understanding of the anuran's evolution.
Underwater photogrammetry for close‐range 3D imaging of dry‐sensitive objects: The case study of cephalopod beaks
Authors: Roscian Marjorie , Herrel Anthony , Cornette Raphaël , Delapré Arnaud , Cherel Yves , Rouget Isabelle
Published: May 2021

Technical advances in 3D imaging have contributed to quantifying and understanding biological variability and complexity. However, small, dry‐sensitive objects are not easy to reconstruct using common and easily available techniques such as photogrammetry, surface scanning, or micro‐CT scanning. Here, we use cephalopod beaks as an example as their size, thickness, transparency, and dry‐sensitive nature make them particularly challenging. We developed a new, underwater, photogrammetry protocol in order to add these types of biological structures to the panel of photogrammetric possibilities.

We used a camera with a macrophotography mode in a waterproof housing fixed in a tank with clear water. The beak was painted and fixed on a colored rotating support. Three angles of view, two acquisitions, and around 300 pictures per specimen were taken in order to reconstruct a full 3D model. These models were compared with others obtained with micro‐CT scanning to verify their accuracy.

The models can be obtained quickly and cheaply compared with micro‐CT scanning and have sufficient precision for quantitative interspecific morphological analyses. Our work shows that underwater photogrammetry is a fast, noninvasive, efficient, and accurate way to reconstruct 3D models of dry‐sensitive objects while conserving their shape. While the reconstruction of the shape is accurate, some internal parts cannot be reconstructed with photogrammetry as they are not visible. In contrast, these structures are visible using reconstructions based on micro‐CT scanning. The mean difference between both methods is very small (10−5 to 10−4 mm) and is significantly lower than differences between meshes of different individuals.

This photogrammetry protocol is portable, easy‐to‐use, fast, and reproducible. Micro‐CT scanning, in contrast, is time‐consuming, expensive, and nonportable. This protocol can be applied to reconstruct the 3D shape of many other dry‐sensitive objects such as shells of shellfish, cartilage, plants, and other chitinous materials.
Eggs survive through avian guts—A possible mechanism for transoceanic dispersal of flightless weevils
Authors: Lin Si‐Min , Li Tsui‐Wen , Liou Chia‐Hsin , Amarga Ace Kevin S. , Cabras Analyn , Tseng Hui‐Yun
Published: May 2021

How flightless animals disperse to remote oceanic islands is a key unresolved question in biogeography. The flightless Pachyrhynchus weevils represent repetitive colonization history in West Pacific islands, which attracted our interests about how some weevils have successfully dispersed in the reverse direction against the sea current. Here, we propose endozoochory as a possible mechanism that the eggs of the weevils might be carried by embedded in the fruits as the food of frugivorous birds. In this study, Pachyrhynchus eggs were embedded in small pieces of persimmon fruits (Diospyros kaki) and fed to captive frugivorous birds. After digestion, 83%–100% eggs were retrieved from the feces of a bulbul (Hypsipetes leucocephalus) and two thrushes (Turdus chrysolaus). The retrieved eggs had hatching rates higher than 84%, which were not different from the control. In contrast, no egg was retrieved from the feces of the frugivorous pigeon (Treron sieboldii), which took a longer retention time in the guts. Our study identified that the eggs of Pachyrhynchus weevils are possible to be transported by internal digesting in some bird species.
Complete blood counts with red blood cell determinants associate with reduced beta‐cell function in seroconverted Swedish TEDDY children
Authors: Salami Falastin , N.Tamura Roy , Elding Larsson Helena , Lernmark Åke , Törn Carina ,   the TEDDY Study Group
Published: May 2021

Objectives

To investigate whether changes in complete blood count (CBC) in islet autoantibody positive children with increased genetic risk for type 1 diabetes are associated with oral glucose tolerance tests (OGTT) and HbA1c over time.

Methods

The Environmental Determinants of Diabetes in the Young (TEDDY) study follows children with increased risk for type 1 diabetes in the United States, Germany, Sweden and Finland. In the current study, 89 Swedish TEDDY children (median age 8.8 years) positive for one or multiple islet autoantibodies were followed up to 5 (median 2.3) years for CBC, OGTT and HbA1c. A statistical mixed effect model was used to investigate the association between CBC and OGTT or HbA1c.

Results

HbA1c over time increased by the number of autoantibodies (p < .001). Reduction in mean corpuscular haemoglobin (MCH) and mean cell volume (MCV) was both associated with an increase in HbA1c (p < .001). A reduction in red blood cell (RBC) counts (p = .003), haemoglobin (p = .002) and haematocrit (p = .006) levels was associated with increased fasting glucose. Increased red blood cells, haemoglobin, haematocrit and MCH but decreased levels of red blood cell distribution widths (RDW) were all associated with increased fasting insulin.

Conclusions

The decrease in RBC indices with increasing HbA1c and the decrease in RBC and its parameters with increasing fasting glucose in seroconverted children may reflect an insidious deterioration in glucose metabolism associated with islet beta‐cell autoimmunity.
Dynamics of growth differentiation factor 15 in acute heart failure
Authors: Lourenço Patrícia , Cunha Filipe M. , Ferreira‐Coimbra João , Barroso Isaac , Guimarães João‐Tiago , Bettencourt Paulo
Published: May 2021

Aims

Risk stratification in acute heart failure (HF) patients can help to decide therapies and time for discharge. The potential of growth differentiation factor 15 (GDF‐15) in HF has been previously shown. We aimed to study the importance of GDF‐15‐level variations in acute HF patients.

Methods and results

We retrospectively evaluated a cohort of patients hospitalized due to acute HF. GDF‐15 was measured both at admission and on the discharge day. Patients were followed‐up during a 3 year period. The endpoint under analysis was all‐cause mortality. GDF‐15 variation is equal to [(admission GDF‐15 − discharge GDF‐15)∕admission GDF‐15] × 100. Variation was categorized in levels of increase or decrease of GDF‐15. Patients were cross‐classified according to admission and discharge GDF‐15 cut‐off points. A Cox regression analysis was used to assess the prognostic impact of GDF‐15 variation and the impact of both admission and discharge GDF‐15 according to the cross‐classification. We studied a group of 249 patients with high co‐morbidity burden. Eighty‐one patients died at 1 year and 147 within 3 years. There was a modest decrease in GDF‐15 during hospitalization from a median value of 4087 to 3671 ng/mL (P = 0.02). No association existed between GDF‐15 variation and mortality. In multivariate analysis, patients with admission GDF‐15 ≥ 3500 ng/mL and discharge GDF‐15 ≥ 3000 ng/mL had a significantly higher 1 year death risk when compared with the remaining—hazard ratio = 2.59 (95% confidence interval: 1.41–4.76)—and a 3 year 1.76 (95% confidence interval: 1.08–2.87) higher death risk compared with those with both values below the cut‐off.

Conclusions

Growth differentiation factor 15 decreased during an acute HF hospitalization, but its variation had no prognostic implications. The knowledge of both admission and discharge GDF‐15 added meaningful information to patients' risk stratification.
Visceral adiposity, muscle composition, and exercise tolerance in heart failure with preserved ejection fraction
Authors: Ying Wendy , Sharma Kavita , Yanek Lisa R. , Vaidya Dhananjay , Schär Michael , Markl Michael , Subramanya Vinita , Soleimani Sahar , Ouyang Pamela , Michos Erin D. , Shah Sanjiv J. , Hays Allison G.
Published: May 2021

Aims

Visceral adipose tissue (AT) promotes inflammation and may be associated with disease progression in heart failure with preserved ejection fraction (HFpEF). We characterized regional AT distribution in HFpEF patients and controls and analysed associations with co‐morbidities and exercise tolerance.

Methods and results

Magnetic resonance imaging was performed to quantify epicardial, liver, abdominal, and thigh skeletal muscle AT. We assessed New York Heart Association (NYHA) class, 6 min walk distance, and global well‐being score. Multivariable linear regression models adjusting for body surface area were used. We studied 55 HFpEF patients (41 women, mean age 67 ± 11 years) and 33 controls (21 women, mean age 57 ± 10 years). Epicardial AT (median [interquartile range] 4.6 [2.0] vs. 3.2 [1.4] mm, P < 0.001), thigh intermuscular fat (11.0 [11.5] vs. 5.0 [2.7] cm2, P < 0.001) and liver fat fraction (6.4% [6.1] vs. 4.1% [5.5], P = 0.001) were higher in HFpEF patients than controls. Women with HFpEF had higher abdominal and thigh subcutaneous AT than men. Greater thigh intermuscular fat was associated with higher blood pressure (β [SE] 0.73 [0.17], P < 0.001) and diabetes (odds ratio [95% confidence interval] 1.2 [1.0–1.5], P = 0.03). Greater thigh intramuscular fat was associated with both worse NYHA class (β [SE] 2.7 [1.0], P = 0.01) and shorter 6 min walk distance (β [SE] −4.1 [1.9], P = 0.03), and greater epicardial AT (β [SE] −0.2 [0.1], P < 0.001) and liver fat fraction (β [SE] −0.4 [0.2], P = 0.04) were associated with lower global well‐being score.

Conclusions

Heart failure with preserved ejection fraction patients have increased epicardial, liver, and skeletal muscle fat compared with controls out of proportion to their increased body size, and adiposity was associated with worse NYHA class and exercise tolerance in HFpEF. These results provide the basis for further investigation into the effect of interventions to reduce regional AT distribution in relation to HFpEF symptoms and pathophysiology.
The impact of platelet indices on clinical outcome in heart failure: results from the MyoVasc study
Authors: Dahlen Bianca , Schulz Andreas , Göbel Sebastian , Tröbs Sven‐Oliver , Schwuchow‐Thonke Sören , Spronk Henri M. , Prochaska Jürgen H. , Arnold Natalie , Lackner Karl J. , Gori Tommaso , ten Cate Hugo , Münzel Thomas , Wild Philipp S. , Panova‐Noeva Marina
Published: May 2021

Aims

Platelet indices have been associated with traditional cardiovascular risk factors, cardiovascular diseases and all‐cause mortality. This study aimed to investigate the role of platelet count, mean platelet volume (MPV) and platelet‐to‐leukocyte ratio, including platelet‐to‐monocyte and platelet‐to‐lymphocyte ratio with cardiac function, heart failure (HF) phenotypes and clinical outcome, worsening of HF.

Methods and results

Univariate and multivariable linear and Cox regression analyses were used to investigate the associations between platelet indices, cardiac function and worsening of HF in 3250 subjects enrolled in the MyoVasc study. Higher MPV, lower platelet count, lower platelet‐to‐leukocyte and platelet‐to‐monocyte ratios have been associated with reduced left ventricular ejection fraction (beta estimate [β]MPV [fL] = −0.05 [−0.09; −0.02], βplatelet count (× 10/L)9 = 3.4 [1.2; 5.6], βplatelet‐to‐leukocyte ratio = 1.4 [1.1; 1.8], βplatelet‐to‐monocyte ratio = 28 [20; 36]) and increased E/E' ratio (β MPV [fL] = 0.04 [0.003; 0.07], βplatelet count (× 10/L)9 = −3.1 [−5.3; −0.92], βplatelet‐to‐leukocyte ratio = −0.83 [−1.2; −0.46], βplatelet‐to‐monocyte ratio = −20 [−28; −12]), independent of age and sex. Cox regression demonstrated an increased risk for worsening of HF in subjects with MPV > 75th percentile (hazard ratio [HR] = 1.47 [1.16; 1.87]), platelet count < 25th percentile (HR = 1.36 [1.07; 1.74]), platelet‐to‐leukocyte < 25th percentile (HR = 1.53 [1.20; 1.95]), platelet‐to‐monocyte < 25th percentile (HR = 1.38 [1.08; 1.77]) and platelet‐to‐lymphocyte > 75th percentile (HR = 1.50 [1.17; 1.93]) ratios, independent of potential confounders. MPV > 75th percentile and platelet count < 25th percentile were strongly related to outcome in HFpEF vs. HFrEF (P for difference = 0.040). Platelet‐to‐leukocyte ratios were associated with worse outcome in both HF phenotypes, without a significant difference between HFpEF and HFrEF.

Conclusions

Platelet indices are linked with worse cardiac function and adverse clinical outcome, independent of subjects' underlying cardiovascular profile. This study emphasizes their important value to provide additional information on pathophysiology and risk stratification in HF syndrome.
A mid‐ventricular variant of Takotsubo syndrome: was it triggered by insular cortex damage?
Authors: Osawa Ayano , Nagai Michiaki , Dote Keigo , Kato Masaya , Oda Noboru , Kunita Eiji , Kagawa Eisuke , Yamane Aya , Kobatake Hiroshi , Shiota Haruko , Ishibashi Naoki , Takahashi Kazuki , Förster Carola Y.
Published: May 2021

Takotsubo syndrome (TTS) is a transient cardiomyopathy that is often associated with cerebrovascular diseases. Earlier studies have supported the concept that the cardiovascular system is regulated by a central autonomic network (CAN) consisting of the insular cortex (IC), anterior cingulate gyrus and amygdala. We report the case of a 79‐year‐old female diagnosed with a mid‐ventricular variant of TTS concomitant with right IC ischaemic stroke. After 12 h of hospitalization, she experienced a sudden collapse. Rapid cardiopulmonary resuscitation resulted in a return of spontaneous circulation. Subsequent left ventriculography revealed akinesis in the mid‐portion of the left ventricle with vigorous contraction of the basal and apex segment. Two weeks after admission, cardiac ultrasound showed improved left ventricular contraction. Right IC ischaemia in this patient might have been associated with a dysregulation of the CAN and subsequent increased sympathetic nervous system activity that triggered TTS.
Copper(II)‐Doped ZIF‐8 as a Reusable and Size Selective Heterogeneous Catalyst for the Hydrogenation of Alkenes using Hydrazine Hydrate
Authors: Nagarjun Nagarathinam , Arthy Kannan , Dhakshinamoorthy Amarajothi
Published: April 2021

In recent years, synthesis of mixed‐metal organic frameworks has received considerable attention due to their superior performance than with mono‐metallic metal organic frameworks (MOFs). In the present manuscript, Cu2+ ions are doped within the framework of ZIF‐8 (ZIF: Zeolitic Imidazolate Frameworks) to obtain Cu@ZIF‐8 and is characterized by powder X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR), UV‐Visible diffuse reflectance spectra (DRS), scanning electron microscope (SEM) and transmission electron microcope (TEM) studies. The reaction conditions are optimized with styrene as a model substrate using Cu@ZIF‐8 as a solid catalyst. Heterogeneity of the reaction is confirmed by leaching test and the solid is reusable for three recycles with no diminishing activity. Further, the structural integrity of Cu@ZIF‐8 is also retained after hydrogenation of styrene as evidenced by powder X‐ray diffraction. The size selective catalysis of Cu@ZIF‐8 is demonstrated by comparing the activity of Cu2+ ions adsorbed over ZIF‐8 solid (Cu/ZIF‐8) in the hydrogenation of 1‐hexene, 1‐octene, cyclohexene, cyclooctene and t‐stilbene. The catalytic results indicate that Cu/ZIF‐8 shows superior activity than Cu@ZIF‐8 for all these olefins due to the lack of diffusion to access the active sites (Cu2+). In contrast, Cu@ZIF‐8 exhibits higher activity for those olefins with lower molecular dimensions (1‐hexene, 1‐octene) than the pores of ZIF‐8 indicating the facile diffusion of these substrates inside the pores ZIF‐8 while poor activity is observed with t‐stilbene due to its larger molecular dimension than the pore apertures of ZIF‐8. These catalytic data clearly establish the size selective hydrogenation of Cu@ZIF‐8 due to the effective confinement provided by ZIF‐8 framework and the presence of the active sites within the framework. Furthermore, this is the first report showing the size selective hydrogenation of olefins promoted by Cu@ZIF‐8 (mixed‐metal MOFs) compared to other noble metal nanoparticles (NPs) embedded over MOFs as catalysts.
Design and 3D modeling investigation of a microfluidic electrode array for electrical impedance measurement of single yeast cells
Authors: Geng Yangye , Zhu Zhen , Zhang Zhao , Xu Feng , Marchisio Mario A. , Wang Zixin , Pan Dejing , Zhao Xiangwei , Huang Qing‐An
Published: May 2021

High‐resolution microscopic imaging may cause intensive image processing and potential impact of light irradiation on yeast replicative lifespan (RLS). Electrical impedance spectroscopy (EIS) could be alternatively used to perform high‐throughput and label‐free yeast RLS assays. Prior to fabricating EIS‐integrated microfluidic devices for yeast RLS determination, systematic modeling and theoretical investigation are crucial for device design and optimization. Here, we report three‐dimensional (3D) finite‐element modeling and simulations of EIS measurement in a microfluidic single yeast in situ impedance array (SYIIA), which is designed by patterning an electrode matrix underneath a cell‐trapping array. SYIIA was instantiated and modeled as a 5 × 5 sensing array comprising 25 units for cell immobilization, culturing, and time‐lapse EIS recording. Simulations of yeast growing and budding in a sensing unit demonstrated that EIS signals enable the characterization of cell growth and daughter‐cell dissections. In the 5 × 5 sensing array, simulation results indicated that when monitoring a target cell, daughter dissections in its surrounding traps may induce variations of the recorded EIS signals, which could cause mistakes in identifying target daughter‐cell dissections. To eliminate the mis‐identifications, electrode array pitch was optimized. Therefore, the results could conduct the design and optimization of microfluidic electrode‐array‐integrated devices for high‐throughput and accurate yeast RLS assays.
Computational insights into electrochemical cross‐coupling of quaternary borate salts
Authors: Matz Florian , Music Arif , Didier Dorian , Jagau Thomas‐C.
Published: May 2021

Cross‐coupling reactions for C–C bond formation represent a cornerstone of organic synthesis. In most cases, they make use of transition metals, which has several downsides. Recently, metal‐free alternatives relying on electrochemistry have gained interest. One example of such a reaction is the oxidation of tetraorganoborate salts that initiates aryl–aryl and aryl–alkenyl couplings with promising selectivities. This work investigates the mechanism of this reaction computationally using density functional and coupled‐cluster theory. The calculations reveal a distinct difference between aryl–alkenyl and aryl–aryl couplings: While C–C bond formation occurs irreversibly and without an energy barrier if an alkenyl residue is involved, many intermediates can be identified in aryl–aryl couplings. In the latter case, intramolecular transitions between reaction paths leading to different products are possible. Based on the energy differences between these intermediates, a kinetic model to estimate product distributions for aryl–aryl couplings is developed.
Should tree invasions be used in treeless ecosystems to mitigate climate change?
Authors: Nuñez Martin A , Davis Kimberley T , Dimarco Romina D , Peltzer Duane A , Paritsis Juan , Maxwell Bruce D , Pauchard Aníbal
Published: May 2021

Intentionally allowing or promoting invasion by non‐native trees into areas characterized by treeless vegetation could contribute to climate‐change mitigation by increasing carbon (C) sequestration. In some areas of the world, incentives exist to retain invasive non‐native trees in natural systems as a mechanism for increasing ecosystem C storage and reducing atmospheric carbon dioxide levels. Although this novel opportunity for C sequestration holds appeal, such an approach is problematic for several reasons: (1) invasive trees do not always increase net C sequestration due to greater occurrence of fire or reduced soil C; (2) lower albedo in invaded areas can increase absorption of solar radiation, thereby offsetting potential C sequestration; and (3) tree invasions often also have negative effects on biodiversity, economic opportunities, and water yield. Such drawbacks are sufficient to raise doubts about the widespread use of non‐native tree invasions in treeless areas as a tool to ameliorate climate change.
Cortical N‐acetylaspartate concentrations are impacted in chronic stroke but do not relate to motor impairment: A magnetic resonance spectroscopy study
Authors: Ferris Jennifer K. , Neva Jason L. , Vavasour Irene M. , Attard Kaitlin J. , Greeley Brian , Hayward Kathryn S. , Wadden Katie P. , MacKay Alex L. , Boyd Lara A.
Published: May 2021

Magnetic resonance spectroscopy (MRS) measures cerebral metabolite concentrations, which can inform our understanding of the neurobiological processes associated with stroke recovery. Here, we investigated whether metabolite concentrations in primary motor and somatosensory cortices (sensorimotor cortex) are impacted by stroke and relate to upper‐extremity motor impairment in 45 individuals with chronic stroke. Cerebral metabolite estimates were adjusted for cerebrospinal fluid and brain tissue composition in the MRS voxel. Upper‐extremity motor impairment was indexed with the Fugl‐Meyer (FM) scale. N‐acetylaspartate (NAA) concentration was reduced bilaterally in stroke participants with right hemisphere lesions (n = 23), relative to right‐handed healthy older adults (n = 15; p = .006). Within the entire stroke sample (n = 45) NAA and glutamate/glutamine (GLX) were lower in the ipsilesional sensorimotor cortex, relative to the contralesional cortex (NAA: p < .001; GLX: p = .003). Lower ipsilesional NAA was related to greater extent of corticospinal tract (CST) injury, quantified by a weighted CST lesion load (p = .006). Cortical NAA and GLX concentrations did not relate to the severity of chronic upper‐extremity impairment (p > .05), including after a sensitivity analysis imputing missing metabolite data for individuals with large cortical lesions (n = 5). Our results suggest that NAA, a marker of neuronal integrity, is sensitive to stroke‐related cortical damage and may provide mechanistic insights into cellular processes of cortical adaptation to stroke. However, cortical MRS metabolites may have limited clinical utility as prospective biomarkers of upper‐extremity outcomes in chronic stroke.
Functional connectivity abnormalities underlying mood disturbances in male abstinent methamphetamine abusers
Authors: Jiang Ping , Sun Jiayu , Zhou Xiaobo , Lu Lu , Li Lei , Huang Xiaoqi , Li Jing , Kendrick Keith , Gong Qiyong
Published: May 2021

Anxiety and depression are the most common withdrawal symptoms of methamphetamine (METH) abuse, which further exacerbate relapse of METH abuse. To date, no effective pharmacotherapy exists for METH abuse and its withdrawal symptoms. Therefore, understanding the neuromechanism underlying METH abuse and its withdrawal symptoms is essential for developing clinical strategies and improving patient care. The aims of this study were to investigate brain network abnormalities in METH abusers (MAs) and their associations with affective symptoms. Forty‐eight male abstinent MAs and 48 age‐gender matched healthy controls were recruited and underwent resting state functional magnetic resonance imaging (fMRI). The severity of patient anxiety and depressive symptoms were measured by Hamilton anxiety and depression rating scales, which decreased across the duration of abstinence. Independent component analysis was used to investigate the brain network functional connectivity (FC) properties. Compared with healthy controls, MAs demonstrated hypo‐intra‐network FC in the cerebellar network and hyper‐intra‐network FC in the posterior salience network. A whole‐brain regression analysis revealed that FC strength of clusters located in the right rostral anterior cingulate cortex (rACC) within the ventromedial network (VMN) was associated with affective symptoms in the patients. Importantly, the intra‐network FC strength of the rACC in VMN mediated the association between abstinence duration and the severity level of affective symptoms. Our results demonstrate alterations in brain functional networks underlying METH abuse, and that the FC of rACC within VMN serve as a neural substrate in the association between abstinence length and affective symptom severity in the MAs.
Local treatment of metastases plus systemic chemotherapy on overall survival of patients with metastatic nasopharyngeal carcinoma
Authors: Liao Wenjun , He Jinlan , Gou Qiheng , Duan Baofeng , Ai Ping , Liu Lei , Li Yanchu , Ren Kexing , Yao Min , Chen Nianyong
Published: May 2021

Background

To investigate the effect of local treatment of metastases on overall survival (OS) of patients with metastatic nasopharyngeal carcinoma (NPC).

Methods

One hundred and forty‐seven patients were included. The association between local treatment and OS was examined with propensity score matching (PSM) method.

Results

In entire cohort, the median OS was significantly longer in patients with local treatment of metastases plus chemotherapy compared to those with chemotherapy alone (71.7 vs. 16.2 months; p < 0.001). In PSM cohort, similar OS benefit of patients with local treatment was observed (55.6 vs. 17.6 months; p = 0.011). The survival benefit of local treatment remained regardless of the number of metastatic lesions and metastatic sites. Patients received radiation doses of >60 Gy had longer OS than those who received less.

Conclusions

Local treatment of metastases could improve OS of patients with metastatic NPC and could be considered in their treatment in addition to chemotherapy.
Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose‐response study
Authors: Delang Nathan , Irwin Christopher , Cox Gregory R , McCartney Danielle , Desbrow Ben
Published: May 2021

This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. Twenty‐nine healthy individuals (23.7 ± 5 years, 16 males) completed two trials (one week apart). Before the trials, participants indicated their “belief” in caffeine's ergogenic effects and previous “experience” using caffeine for performance. On arrival, participants randomly received either sham “Low (100mg; LD)” or “High (300mg; HD)” dose caffeine capsules 30‐min before commencing the CRT test, followed by a 10km run. Paired samples t‐tests determined differences between trials for CRT latency (Ex‐Gaussian analysis; μ‐, σ‐ and τ‐) and running performance using the entire cohort and sub‐groups exhibiting strong “beliefs”+/−“experience”. Sham caffeine dose did not influence CRT (μ‐, σ‐ and τ‐respectively, LD: 400 ± 53ms vs. HD: 388 ± 41ms; LD: 35 ± 18ms vs. HD: 34 ± 17ms; LD: 50 ± 24ms vs. HD: 52 ± 19ms, all p's > 0.05). Neither belief (n = 6), nor belief + experience (n = 4), influenced this effect. Furthermore, caffeine dose did not influence run time (LD: 49.05 ± 3.75min vs. HD: 49.06 ± 3.85min, p = 0.979). Belief (n = 9) (LD: 48.93 ± 3.71min vs. HD: 48.9 ± 3.52min, p = 0.976), and belief + experience (n = 6) (LD: 48.68 ± 1.87min vs. HD: 49.55 ± 1.75min, p = 0.386) didn't influence this effect. A dose‐response to sham caffeine ingestion was not evident on cognitive or endurance performance in healthy individuals, regardless of their convictions about caffeine's ergogenicity.
The Kwakshua Watersheds Observatory, central coast of British Columbia, Canada
Authors: Giesbrecht Ian J. W. , Floyd William C. , Tank Suzanne E. , Lertzman Ken P. , Hunt Brian P. V. , Korver Maartje C. , Oliver Allison A. , Brunsting Ray , Sanborn Paul , Gonzalez Arriola Santiago G. , Frazer Gordon W. , St. Pierre Kyra A. , Hateley Shawn , McPhail James , Owen Colby , Butler Stewart , Fedje Bryn , Myers Emma , Quayle Lucy , Haughton Emily , Desmarais Isabelle , White Rob , Levy‐Booth David J. , Kellogg Colleen T. E. , Jackson Jennifer M. , Mohn William W. , Hallam Steven J. , Del Bel Belluz Justin
Published: April 2021

The Kwakshua Watersheds Observatory (KWO) is an integrative watersheds observatory on the coastal margin of a rain‐dominated bog‐forest landscape in British Columbia (BC), Canada. Established in 2013, the goal of the KWO is to understand and model the flux of terrestrial materials from land to sea – the origins, pathways, processes and ecosystem consequences – in the context of long‐term environmental change. The KWO consists of seven gauged watersheds and a network of observation sites spanning from land to sea and along drainage gradients within catchments. Time‐series datasets include year‐round measurements of weather, soil hydrology, streamflow, aquatic biogeochemistry, microbial ecology and nearshore oceanographic conditions. Sensor measurements are recorded every 5 min and water samples are collected approximately monthly. Additional observations are made during high‐flow conditions. We used remote sensing to map watershed terrain, drainage networks, soils and terrestrial ecosystems. The watersheds range in size from 3.2 to 12.8 km2, with varying catchment characteristics that influence hydrological and biogeochemical responses. Despite local variation, the overall study area is a global hotspot for yields of dissolved organic carbon, dissolved organic nitrogen and dissolved iron at the coastal margin. This observatory helps fill an important gap in the global network of observatories, in terms of spatial location (central coast of BC), climate (temperate oceanic), hydrology (very high runoff, pluvial regime), geology (igneous intrusive, glacially scoured), vegetation (bog rainforest) and soils (large stores of organic carbon).
Differential genetic influences over colorectal cancer risk and gene expression in large bowel mucosa
Authors: Vaughan‐Shaw Peter. G. , Timofeeva Maria , Ooi Li‐Yin , Svinti Victoria , Grimes Graeme , Smillie Claire , Blackmur James P. , Donnelly Kevin , Theodoratou Evi , Campbell Harry , Zgaga Lina , Din Farhat V. N. , Farrington Susan M. , Dunlop Malcolm G.
Published: May 2021

Site‐specific variation in colorectal cancer (CRC) incidence, biology and prognosis are poorly understood. We sought to determine whether common genetic variants influencing CRC risk might exhibit topographical differences on CRC risk through regional differences in effects on gene expression in the large bowel mucosa. We conducted a site‐specific genetic association study (10 630 cases, 31 331 controls) to identify whether established risk variants exert differential effects on risk of proximal, compared to distal CRC. We collected normal colorectal mucosa and blood from 481 subjects and assessed mucosal gene expression using Illumina HumanHT‐12v4 arrays in relation to germline genotype. Expression quantitative trait loci (eQTLs) were explored by anatomical location of sampling. The rs3087967 genotype (chr11q23.1 risk variant) exhibited significant site‐specific effects—risk of distal CRC (odds ratio [OR] = 1.20,P = 8.20 × 10−20) with negligible effects on proximal CRC risk (OR = 1.05,P = .10). Expression of 1261 genes differed between proximal and distal colonic mucosa (top hitPRACgene, fold‐difference = 10,P = 3.48 × 10−57). In eQTL studies, rs3087967 genotype was associated with expression of 8 cis‐ and 21 trans‐genes. Four of these (AKAP14,ADH5P4,ASGR2,RP11‐342M1.7) showed differential effects by site, with strongest trans‐eQTL signals in proximal colonic mucosa (eg,AKAP14, beta = 0.61,P = 5.02 × 10−5) and opposite signals in distal mucosa (AKAP14, beta = −0.17,P = .04). In summary, genetic variation at the chr11q23.1 risk locus imparts greater risk of distal rather than proximal CRC and exhibits site‐specific differences in eQTL effects in normal mucosa. Topographical differences in genomic control over gene expression relevant to CRC risk may underlie site‐specific variation in CRC. Results may inform individualised CRC screening programmes.
A dynamic prediction score for obstetric anal sphincter injury among nulliparous women delivering vaginally
Authors: Meyer Raanan , Schwartz Anat , Horesh Nir , Alcalay Menachem , Ram Edward , Levin Gabriel
Published: April 2021

Objective

To develop a risk score for obstetric anal sphincter injury (OASI) occurrence among nulliparous women delivering vaginally, based on data available at admission for delivery and as labor progresses.

Methods

A retrospective study of all nulliparous women who delivered vaginally between March 2011 and January 2021. Characteristics were compared between OASI and no‐OASI groups. Multivariable analyses were performed to identify independent risk factors for OASI occurrence.

Results

OASI occurred in 453 (1.7%) of 26 081 women who met the inclusion criteria. The following variables were independently associated with OASI: maternal height (adjusted odds ratio [aOR] 0.97, 95% confidence interval (CI) 0.95–0.99), hypertensive disorders (aOR 1.74, 95% CI 1.03–2.95), sonographic fetal weight estimation (aOR 1.00, 95% CI 1.00–1.00), second‐stage duration (aOR 1.00, 95% CI 1.00–1.00), occiput posterior position (aOR 2.87, 95% CI 1.79–4.62), and episiotomy performance (aOR 0.63, 95% CI 0.47–0.84). In a risk score based on variables available at admission for delivery, the presence of two factors was associated with 4.3% OASI risk. Upon incorporating intrapartum variables, the presence of two risk factors was associated with 2.9% OASI rate.

Conclusion

A dynamic risk score for OASI occurrence based on data available at admission for delivery and as delivery progresses can assist in counseling regarding OASI risk.

A dynamic risk score for obstetric anal sphincter injury occurrence based on data available at admission for delivery and intrapartum was developed.
A large adrenocortical adenoma surrounded with a renal arteriovenous malformation
Authors: Nishino Takato , Narimoto Kazutaka , Tominaga Koki , Sano Masayuki , Shimbo Masaki , Muraishi Natsuka , Kanomata Naoki , Hattori Kazunori
Published: May 2021

Introduction

Large adrenal adenomas are clinically rare. We report a case of a large adrenal adenoma with a renal arteriovenous malformation, mimicking a malignant adrenal tumor in preoperative imaging.

Case presentation

A 66‐year‐old woman presented to a local hospital with abdominal pain. A right adrenal tumor was detected, 66 mm in diameter and surrounded by thick and tortuous vessels. Based on the imaging findings, pheochromocytoma was suspected. However, clinical symptoms and endocrine abnormalities were absent, and radionuclide accumulation in scintigraphy was negative. Laparoscopic right adrenalectomy was performed. Intraoperatively, a notable growth of vessels forming a nidus surrounding the tumor was observed. Pathologically, this was diagnosed as an adrenocortical adenoma in conjunction with a renal arteriovenous malformation.

Conclusion

We report a case of a large adrenal tumor surrounded with an arteriovenous malformation. To the best of our knowledge, this is the first reported case of this combination.
Classification of the four‐class motor imagery signals using continuous wavelet transform filter bank‐based two‐dimensional images
Authors: Mahamune Rupesh , Laskar Shahedul H.
Published: May 2021

The feature extraction technique plays a vital role in obtaining better classification accuracy. In this paper, a novel framework is proposed, which develops two‐dimensional (2D) images for convolutional neural network (CNN) to classify four (left hand, right hand, feet, and tongue) MI tasks. 2D image is formed by decomposing each trial using continuous wavelet transform (CWT) filter bank after pre‐processing the MI‐based EEG data by multi‐class common spatial pattern (CSP) method. Obtained images are used to train the CNN model for classification. The proposed framework is evaluated using publicly available BCI competition IV dataset 2a by calculating the classification accuracy for all subjects. Results show that the proposed framework has been giving better classification accuracy than some existing CNN‐based and conventional machine learning‐based approaches compared in this paper. The average time required to train CNN using the proposed framework is 12.67 s, acceptable for online MI‐based BCI applications.
Effects of mowing height and Cynodon spp. cultivar on traffic tolerance
Authors: Strunk William , Dickson Kyley , Sorochan John , Thoms Adam
Published: May 2021

Athletic field managers often adjust agronomic practices according to the desires of coaches and athletes. One such agronomic practice often adjusted is mowing height. In an attempt to have athletes run faster, field managers are persuaded to reduce mowing height, thereby reducing potential friction from the surface on an athlete. With newer bermudagrass [Cynodon datylon (L.) Pers.] and hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] cultivars, maintaining a field at reduced mowing heights is much easier to achieve without apparent negative effects on surface performance. However, these expected effects have not been verified through rigorous research and are solely dependent on anecdotal data. The objectives of this study were to compare traffic tolerance of four hybrid bermudagrass cultivars ‐ ‘Latitude 36 Turf Bermudagrass’ (Latitude 36) and ‘Northbridge Turf Bermudagrass’ (Northbridge), ‘Tifway’, and ‘Patriot’ ‐ and two bermudagrass cultivars ‐ ‘Riviera’, and ‘Hollywood’ ‐ and determine the effect of mowing height on traffic tolerance. Treatments were arranged in a randomized complete block design with eight replications. Measurements of percent green cover, surface hardness, and peak rotational traction were collected before, during, and after simulated traffic. Latitude 36 and Northbridge were more traffic tolerant than any of the other cultivars tested. While there was not an interaction between cultivars and mowing height, the higher mowing height had greater traffic tolerance.