bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of doping variation on band gap energy and crystal structure of Biochar/TiO2 thin layer
Authors: Fahyuan H D , Deswardani F , Nurhidayah N , Afrianto M F , Heriansyah H , Nazaruddin N , Nelson N
Published: January 2021

The biochar/TiO2 thin layer has been made by using the sol-gel method and the coating technique by Doctor Blade method. The variation of biochar on TiO2 were 0%, 1%, 2%, 3% and 4%. The characterization was done by using XRD (X-Ray Diffractometer) to see the crystal structure of samples and UV-Vis spectrophotometer to obtain the value of band gap energy. Based on XRD data, it was obtained that the crystal structure of all samples is anatase TiO2. The crystalline size of all samples has no significant difference by the increasing of doping percentage. The smallest crystal size was at the addition of 3% and 4% bio char which was 118.22 nm. The results of UV-Vis characterization showed the lowest value of band gap energy was at sample doping 1% bio char which was 3.25 eV. Band gap energy value for doping sample above 1% showed an increase of band gap energy of Biochar-TiO2.
Driving energy to accelerate the adiabatic electron dynamics in quantum Hall system
Authors: Setiawan I , Syarkowi A , Syatyatuhu A , Gunara B E
Published: January 2021

We study a scheme of accelerated adiabatic quantum dynamics. This scheme was originally proposed by Masuda-Nakamura. The strategy of combining two opposite idea: infinitely-large time-magnification factor (ᾱ) and infinitely-small growth rate (ɛ) of adiabatic parameter was elucidated. We apply the proposed method to the Hall system with electric and magnetic field and obtain regularization term, driving potential VFF
and driving Hamiltonian HFF
to accelerate the system. The driving potential VFF
and the driving Hamiltonian HFF
to be able to accelerate adiabatic electron dynamics in the ground state trapped in the plane xy and electric field in the x direction and a constant magnetic field in y direction.
Development of ARIMA technique in determining the ocean climate prediction skills for pre-service teacher
Authors: Rosmiati R , Liliasari S , Tjasyono B , Ramalis T R
Published: January 2021

The lack of community understanding of the predictions of the ocean climate is key to addressing the impacts and crisis of the ocean climate. The aims of this study is to explain the stages of ocean climate prediction skills using the ARIMA technique for pre service teacher students as beginner learners and provide solutions to build a conscious and responsive attitude to the ocean climate. The data used is Sea Surface Temperature (SST) Niǹo 3.4, analysis the stages of the Autoregressive Integrated Moving Average (ARIMA) model used MINITAB 16.0 and Microsof Excel that has been developed then applied by 3 respondents. Based on the results of the study, more detailed stages of the arima model and n 3 respondents both got a correlation value of 0.96 for Nino SST 3.4 original value and model value, correlation 0.92 for 1 year validation and correlation 0.99 ENSO prediction for 1 year (12 months) ahead. Thus the development of the ARIMA model stage is very effective to be used to predict climate such as ENSO events and other ocean climate phenomena.
Improving activities and learning outcomes of biology education students through learning Problem-Based Learning model of entrepreneurship
Authors: Yani A P , Parlindungan D , Yennita Y
Published: January 2021

This study aims to describe the activities of lecturers, student activities and student learning outcomes on creative thinking material in biology study programs, by applying the Problem-Based Learning (PBL) learning model. This type of research is classroom action research (CAR) with descriptive methods. This research was conducted in 2 cycles, each cycle consisting of 4 stages: planning, implementing, observing and reflecting. Research subjects are lecturers and all semester 5th students of biology study programs. The research variable is the learning model Problem-Based Learning and student learning outcomes. Data collection techniques used are observation and tests. While the research instruments consisted of observation sheets and test sheets. The results of the analysis of lecturer activity data in cycle 1 obtained an average of 33.5 (good) and cycle 2 rose to 35 (good). The results of the analysis of student learning activity data cycle 1 obtained an average score of 29 (good) cycle 2 increased to 34 (good). Student learning outcomes tested by the T-test showed that significantly showed an increase in the value of learning outcomes in cycle 1 (3.02439) and in cycle 2 (7.26829). It was concluded that the Problem-Based Learning (PBL) learning model can improve student learning activities as well as student learning outcomes that take entrepreneurship courses in Biology education courses.
An experimental study on tribological properties and air tightness of co-textured cylinder liner-piston ring on an engine tester
Authors: Miao Chenwei , Guo Zhiwei , Yuan Chengqing
Published: January 2021

The performance of cylinder liner-piston ring (CLPR) affects the efficiency of marine engine greatly. An experimental study on textured CLPR was conducted to seek insight into the operation reliability of CLPR. Three types of surface texture, groove texture on cylinder liner, dimple texture on piston ring, and co-texture on both sides, were processed. A series of tests were then carried out on an engine tester. Three characterization parameters, contact resistance, worn surface topography on cylinder liner, and cylinder pressure were used to describe the CLPR tribological properties and air tightness. The results showed that the three textures all improved tribological properties. Compared to the non-textured surface, the contact resistance of the three textures increased 30.7%, 71.7% and 98.4% on average. The wear resistance of dimple texture was weaker than that of groove texture. Air tightness was closely related to oil film pressure. At dead centre, the cylinder pressure of the three textures respectively was optimized by 4.6 kPa, 7.8 kPa and 12.3 kPa averagely. The co-texture was shown to combine the advantages of groove texture with the advantages of dimple texture, which provided the surface with improved oil film distribution and more efficient debris trapping, resulting in the optimum tribological properties and air tightness among the three textures.
Parametric optimization and analysis of cavitation erosion behavior of Ni-based + 10WC microwave processed composite clad using Taguchi approach
Authors: Bansal Sandeep , Mago Jonty , Gupta Dheeraj , Jain Vivek
Published: January 2021

This study aims to develop cavitation erosion-resistant clads on stainless steel (SS-316) using the microwave cladding technique. Ni-based alloy powder (EWAC) was reinforced with tungsten carbide (10% by wt) powder to obtain composite clads. The cladding process was carried out in a domestic microwave applicator of 2.45 GHz frequency with 900 W power. The microstructure, crystal structure (phase identification and quantification), and microhardness of the developed clad were investigated with scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD), and Vickers microhardness tester, respectively. It was found that the deposited clad has a uniform thickness of ∼520 μm, and the microstructure mainly consists of equally dispersed and agglomerated carbides in cellular like Ni-Matrix. XRD analysis reveals that the composite clad was composed of various intermetallic, carbide, and oxide phases. The EWAC + 10WC clad (625 ± 81 HV0.3) has a hardness ∼3.5 times higher than the stainless steel substrate (195 ± 15 HV0.3). The cavitation erosion behavior of the SS-316 and EWAC + 10WC clad was examined by using a vibratory cavitation test apparatus. The parametric cavitation erosion testing was conducted according to the Taguchi L9 orthogonal array (OA) to study the effects of variations in amplitude (AMP), immersion depth (ID), and standoff distance (SOD) on mass loss in SS-316 and composite clad. The parametric study results show that SOD was the most influential test parameter, followed by AMP and ID. SOD contributes more than 50% in the mass loss of SS-316 and clad specimens, whereas AMP and ID contribution was around 32%–37% and 7%–11%, respectively. The developed EWAC + 10WC clad performed ∼6.7 times better than the SS-316. Nevertheless, the SS-316 and EWAC + 10WC clad specimens got severely damage in the form of pits, craters, plastic deformation, lip formation, impingement marks, and secondary cracks.
HUNTER: precision massive-neutrino search based on a laser cooled atomic source
Authors: Martoff C J , Granato F , Palmaccio V , Yu X , Smith P F , Hudson E R , Hamilton P , Schneider C , Chang E , Renshaw A , Malatino F , Meyers P D , Lamichhane B
Published: January 2021

We describe a project that brings together researchers from atomic physics, nuclear physics and sub-atomic particle physics, to develop a high-precision laboratory-scale experiment able to search for very weakly coupled sterile neutrinos in the mass range extending from 5–10 keV/c
2 to several 100 keV/c
2. Observed neutrino flavor eigenstates are known to be quantum mixtures of at least three sub-eV/c
2 mass eigenstates. There is a strong theoretical belief that there may exist further neutrino mass eigenstates at higher mass levels, and which, if in the keV/c
2 mass range, might form all or part of the galactic dark matter. This has led to many searches for anomalous events in both astrophysical and particle physics experiments, and searches for distortions in beta decay spectra. The present experiment will utilize K-capture events in a population of 131Cs atoms suspended in vacuum by a magneto-optical trap (MOT). Using AMO and nuclear physics techniques, individual events will be fully reconstructed kinematically. Normally each event would be consistent with an emitted neutrino mass close to zero, but the existence of a sterile neutrino of keV/c
2 mass that mixes with the electron type neutrino produced in the decay would result in a separated population of events with non-zero reconstructed missing mass (up to the Q = 352 keV available energy of the reaction). Detailed calculations and simulations of all significant background processes have been made, in particular for scattering in the source itself, radiative K-capture, local radioactivity, cosmic ray muons, and knock-out of electrons by x-rays. A phase 1 of the experiment, under construction with funding from the W M Keck Foundation, has the potential to reach sterile neutrino mixing angles down to sin2 
θ ∼ 10−4. With further upgrades this technique could be progressively improved to eventually reach much lower coupling levels ∼10−10, in particular reaching the level needed to be consistent with galactic dark matter below the astrophysical x-ray limits.
Photonic nanojets and their applications
Authors: Darafsheh Arash
Published: January 2021

Dielectric microelements with circular symmetry have shown interesting optical properties: photonic nanojets (PNJs) and whispering gallery modes (WGMs). They can confine light inside the cavity, forming WGMs, or focus the light in their proximity, forming PNJs. Both WGMs and PNJs have found numerous applications, including sensing and imaging. In this work, a review of PNJs and their applications in contemporary literature is provided.
Enantiomeric Separation and Thermodynamic Investigation of (R)-N-Tert-Butoxy Carbonyl-Piperidine-3-Carboxylic Acid Hydrazide, a Key Starting Material of Zidebactam
Authors: Rane Vipul P , Ahirrao Vinod K , More Kiran B , Yeole Ravindra D
Published: January 2021

A new selective, accurate and precise chiral high-performance liquid chromatography method for the separation of (R)-N-tert-butoxy carbonyl-piperidine-3-carboxylic acid hydrazide (RE) and its enantiomer was developed. RE is a key starting material of novel β-lactam enhancer drug Zidebactam. Chiral resolution of more than 10 was achieved on Chiralpak IA column using mobile phase consisting of n-hexane, ethanol in the ratio of 70:30, v/v. The flow rate of the mobile phase was 1.0 mL min−1 and the column oven temperature was 30°C. Detection was carried out at 225 nm. The developed method was validated as per the International Conference on Harmonization guideline. Limit of detection and limit of quantification of the enantiomeric impurity (S)-N-tert-butoxy carbonyl-piperidine-3-carboxylic acid hydrazide (SE) was 2.5 and 7.5 μg mL−1, respectively. Mean recovery of the SE was 96.83 ± 1.4%. The effect of thermodynamic parameters on the chiral separation was evaluated.
Esophagectomy combined with off-pump coronary artery bypass grafting through left posterolateral incision is safe and feasible for esophageal cancer associated with coronary artery disease
Authors: Ding C-Z , Wang G-L , Wang H-T , Wang W-G , Wang L , Wang P-F , Zhu R-J , Liu X , Wang J-H , Wang J , Zhao S
Published: January 2021

Controversy still exists as to whether surgical treatment has any impact on the long-term survival of esophageal cancer (EC) patients with coronary artery disease treated with curative esophagectomy combined with off-pump coronary artery bypass grafting (OPCABG). Therefore, the aim of this study was to introduce and assess the effect of esophagectomy combined with OPCABG on both short- and long-term outcomes. From January 2010 to January 2015, 1428 EC or esophagogastric junction cancer patients underwent surgical treatment at Henan Chest Hospital, Zhengzhou, China. The clinical data of 25 patients who underwent EC resection through a left thoracotomy following OPCABG and the perioperative characteristics and follow-up results were analyzed. The majority of the patients were male, and the EC stage was predominantly cT2N0-1M0 II. The most common pathological types were squamous cell carcinoma. The EC surgeries consisted of 15 chest anastomosis procedures and 10 cervical anastomosis procedures with aortocoronary graft implantation (mean: 2.36 grafts per patient). The mean total operative time was 330.8 ± 83.5 minutes. The median intensive care unit and hospital lengths of stay were 1.72 and 21.16 days, respectively. Resection without macroscopic residual disease (R0) was achieved in all of the patients. The most frequent complications included pulmonary infections (24%), arrhythmias (24%), pleural effusion (12%), and esophageal anastomotic leakage (8%). There were no postoperative deaths or myocardial infarctions within 30 days after the surgery. The overall 1-, 3-, and 5-year survival rates were 88%, 40%, and 24%, respectively, with a median survival time of 43 months. In the short-term, radical resection of EC following OPCABG is a safe and feasible treatment with low postoperative mortality rates. In the long-term, simultaneous surgery is acceptable and is associated with favorable overall and disease-free survival.
Factors influencing development of non-cardiac chest pain after endoscopic submucosal dissection for esophageal neoplasms: a retrospective case–control study of 309 patients from a single center
Authors: Zhao Dian , Liu Ying , Wang Lei , Xu Guifang , Lv Ying , Ling Tingsheng , Zhang Xiaoqi , Liang Ying , Wang Erhua , Zhang Yiyang , Zou Xiaoping , Zhang Bin
Published: January 2021

Endoscopic submucosal dissection (ESD) is widely used for early stage esophageal cancer and precancerous lesions. Non-cardiac chest pain (NCCP) is a frequent complication of ESD. However, little is known about its incidence and associated factors. This study investigated the pain incidence and predictive factors for pain development after ESD for esophageal neoplasms. We enrolled a total of 309 patients with esophageal neoplasms, who underwent ESD in our center from January 2018 to June 2019. Sociodemographic and clinicopathological information for all patients was collected, and patients were divided into either a pain-free group (n = 156) or a pain group (n = 153) according to whether there was onset of NCCP 24–48 hours after surgery. We made comparisons between groups using Student’s t test or the χ2 test. Logistic-regression analysis was used to screen for risk factors. There were statistically significant differences in histories of previous surgery (P = 0.039), lesion size (P = 0.026), operation time (P = 0.009), and postoperative fever (P = 0.001). History of previous surgery (P = 0.043) and postoperative fever (P = 0.007) were independent risk factors for chest pain after esophageal ESD treatment. Chest pain and fever prolonged postoperative hospitalization time (P = 0.005, P = 0.001) and increased hospitalization cost (P = 0.034, P < 0.001). A history of previous surgery and postoperative fever was associated with the occurrence of NCCP after ESD in patients with esophageal neoplasms. NCCP and fever after esophageal ESD increased both hospitalization time and cost.
Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure
Authors: Secinaro Aurelio , Milano Elena Giulia , Ciancarella Paolo , Trezzi Matteo , Capelli Claudio , Ciliberti Paolo , Cetrano Enrico , Curione Davide , Santangelo Teresa Pia , Napolitano Carmela , Albanese Sonia B , Carotti Adriano
Published: January 2021

Aims

The aortic valve (AV) neocuspidization (Ozaki procedure) is a novel surgical technique for AV disease that preserves the natural motion and cardiodynamics of the aortic root. In this study, we sought to evaluate, by 4D-flow magnetic resonance imaging, the aortic blood flow characteristics after AV neocuspidization in paediatric patients.

Methods and results

Aortic root and ascending aorta haemodynamics were evaluated in a population of patients treated with the Ozaki procedure; results were compared with those of a group of patients operated with the Ross technique. Cardiovascular magnetic resonance studies were performed at 1.5 T using a 4D flow-sensitive sequence acquired with retrospective electrocardiogram-gating and respiratory navigator. Post-processing of 4D-flow analysis was performed to calculate flow eccentricity and wall shear stress. Twenty children were included in this study, 10 after Ozaki and 10 after Ross procedure. Median age at surgery was 10.7 years (range 3.9–16.5 years). No significant differences were observed in wall shear stress values measured at the level of the proximal ascending aorta between the two groups. The analysis of flow patterns showed no clear association between eccentric flow and the procedure performed. The Ozaki group showed just a slightly increased transvalvular maximum velocity.

Conclusion

Proximal aorta flow dynamics of children treated with the Ozaki and the Ross procedure are comparable. Similarly to the Ross, Ozaki technique restores a physiological laminar flow pattern in the short-term follow-up, with the advantage of not inducing a bivalvular disease, although further studies are warranted to evaluate its long-term results.
Prognostic role of transferrin saturation in heart failure patients
Authors: Campodonico Jeness , Nicoli Flavia , Motta Irene , Migone De Amicis Margherita , Bonomi Alice , Cappellini Maria , Agostoni Piergiuseppe
Published: January 2021

Aims

In heart failure (HF) iron deficiency (ID) is frequently observed and represents a major mortality risk factor. Purpose of this study was to evaluate the correlation between mortality and ID in a cohort of 661 consecutive patients hospitalized for HF worsening.

Methods and results

Patients were grouped: (i)according to presence(+)/absence(−) of anaemia (A) and ID defined following World Health Organization (WHO) and European Society of Cardiology (ESC)–American College of Cardiology/American Heart Association/HF society of America (ACC/AHA/HFSA) definitions, respectively: Group A−ID− (n = 123), Group A+ID− (n = 80), Group A+ID+ (n = 247), and Group A−ID+ (n = 211); (ii) according to presence of absolute (serum ferritin < 100μg/L) and functional ID [ferritin between 100 and 300μg/L and transferrin saturation (TSAT) < 20%]; and (iii) according to TSAT <20% and ≥20%. Groups were not different for several clinical features but age, gender, kidney function, and chronic obstructive pulmonary disease. Average follow-up was 1.94 year (±420 days). Overall 5 years mortality rate was 29.5%. Only anaemia and functional ID but not ID as defined by guidelines showed an impact on prognosis. Transferrin saturation <20% (n = 360) patients showed worst prognosis compared to TSAT ≥20% (n = 301) patients. In addition, functional ID patients showed worse prognosis compared patients with ferritin <100μg/L and TSAT <20% or ≥20% likely due to more severe chronic inflammatory status [C-reactive protein, 7.4 (interquartile range 2.7–22.6) and 3.2 (1.4–8.7) mg/L, P < 0.0001 respectively].

Conclusion

We confirmed that in HF anaemia is associated to a poor prognosis. Moreover, we showed that patients with TSAT <20% had worse prognosis compared to those with TSAT ≥20% but the composite of ferritin between 100 and 300 μg/L and TSAT <20% identifies HF patients with the poorest survival rate.
Repression of the TreR transcriptional regulator in Streptococcus mutans by the global regulator, CcpA
Authors: Lindsay E L , Faustoferri R C , Quivey R G
Published: January 2021

Streptococcus mutans, the etiologic agent of dental caries in humans, is considered a dominating force in the oral microbiome due to its highly-evolved propensity for survival. The oral pathogen encodes an elaborate array of regulatory elements, including the carbon catabolite-responsive regulator, CcpA, a global regulator key in the control of sugar metabolism and in stress tolerance response mechanisms. The recently characterized trehalose utilization operon, integral for the catabolism of the disaccharide trehalose, is controlled by a local regulator, TreR, which has been implicated in a number of cellular functions outside of trehalose catabolism. Electrophoretic mobility shift assays demonstrated that CcpA bound a putative cre site in the treR promoter. Loss of ccpA resulted in elevated expression of treR in cultures of the organism grown in glucose or trehalose, indicating that CcpA not only acts as a repressor of trehalose catabolism genes, but also the local regulator. The loss of both CcpA and TreR in S. mutans resulted in an impaired growth rate and fitness response, supporting the hypothesis that these regulators are involved in carbon catabolism control and in induction of components of the organism's stress response.
SELECTION COMPONENTS IN BACKGROUND REPLACEMENT LINES OF DROSOPHILA
Authors: Clark Andrew G , Bundgaard Jørgen
Published: January 2021

Selection components analysis was performed in lines of Drosophila melanogaster at three times during substitution backcrossing. The initial two lines were inbred isofemale lines from natural populations in California, and one had the spread wing mutation eagle. The selection components analysis revealed aspects of the genetic structure of the determinants of fitness by demonstrating changes in the marginal fitnesses of the eagle locus. Differences among backgrounds essentially disappeared by the 20th generation of backcrossing, suggesting that the previously observed differences were attributable to linkage disequilibrium. The method of bootstrapping was used as a novel means of determining statistical confidence in selection components.
CLONING AND CHARACTERIZATION OF YEAST LEU4, ONE OF TWO GENES RESPONSIBLE FOR α-ISOPROPYLMALATE SYNTHESIS
Authors: Chang Li-fen L , Cunningham Thomas S , Gatzek Paula R , Chen Wen-Ji , Kohlhaw Gunter B
Published: January 2021

By complementation of an α-isopropylmalate synthase-negative mutant of Saccharomyces cerevisiae (leu4 leu5), a plasmid was isolated that carried a structural gene for α-isopropylmalate synthase. Restriction mapping and subcloning showed that sequences sufficient for complementation of the leu4 leu5 strain were located within a 2.2-kilobase Sal I-PvuII segment. Southern transfer hybridization indicated that the cloned DNA was derived intact from the yeast genome. The cloned gene was identified as LEU4 by integrative transformation that caused gene disruption at the LEU4 locus. When this transformation was performed with a LEU4fbr LEU5 strain, the resulting transformants had lost the 5',5',5'-trifluoro-d,l-leucine resistance of the recipient strain but were still Leu+. When it was performed with a LEU4 leu5 recipient, the resulting transformants were Leu-. The α-isopropylmalate synthase of a transformant that carried the LEU4 gene on a multicopy plasmid (in a leu5 background) was characterized biochemically. The transformant contained about 20 times as much α-isopropylmalate synthase as wild type. The enzyme was sensitive to inhibition by leucine and coenzyme A, was inactivated by antibody generated against α-isopropylmalate synthase purified from wild type and was largely confined to the mitochondria. The subunit molecular weight was 65,000-67,000. LImited proteolysis generated two fragments with molecular weights of about 45,000 and 23,000. Northern transfer hybridization showed that the transformant produced large amounts of LEU4-specific RNA with a length of about 2.1 kilonucleotides. The properties of the plasmid-encoded enzyme resemble those of a previously characterized α-isopropylmalate synthase that is predominant in wild-type cells. The existence in yeast of a second α-isopropylmalate synthase activity that depends on the presence of an intact LEU5 gene is discussed.
A CHROMOSOME REPLICATION PATTERN DEDUCED FROM PERICARP PHENOTYPES RESULTING FROM MOVEMENTS OF THE TRANSPOSABLE ELEMENT, MODULATOR, IN MAIZE
Authors: Greenblatt Irwin M
Published: January 2021

Modulator (Mp) was mapped after it transposed from the P locus on chromosome 1 by studying 105 light variegated/red twin sectors on medium variegated pericarp ears. Sixty-one percent of the receptor sites were detectably linked to P, and these showed an asymmetry of distribution adjacent to P. No transpositions were mapped in the 4 map units proximal to P, whereas 23 cases mapped to the same length distal to P. The remaining transpositions of Mp on chromosome 1, both proximal and distal to P, were equally scattered. It has previously been shown that when Modulator transposes it replicates at the P locus and a second time at the receptor site. The pattern of transposition adjacent to P is consistent with a hypothesis that a replicon initiation site is situated proximal to P; that Modulator transposes at the time of replication; that it is not able to transpose into a replicated region but only into a replicating one. No difference in distribution of receptor sites was found when the Modulator was detected vs. not detected in the red co-twins by testing with a Dissociation element.
GENETIC DRIFT IN A CLINE
Authors: Slatkin Montgomery , Maruyama Takeo
Published: January 2021

A model is developed of genetic drift in a cline maintained by spatially varying natural selection and local dispersal of individuals. The model is analyzed by an approximation scheme which is valid for weak selection and small migration rates. The results, which are based on numerical iterations of the approximate equations, are that the cline is less steep than predicted on the basis of the deterministic theory but that for weak selection the correlation between random fluctuations in neighboring colonies is approximately the same as in models of migration and drift in the absence of selection.
EVIDENCE OF TANDEM DUPLICATION OF GENES IN A MERODIPLOID REGION OF PNEUMOCOCCAL MUTANTS RESISTANT TO SULFONAMIDE
Authors: Kashmiri S V S , Hotchkiss Rollin D
Published: January 2021

A Pneumococcal mutant, sulr-c, resistant to sulfonamides, and three transformants bearing associated d or d  + resistance markers have earlier been reported to be unstable and show distinct patterns and frequencies of segregating stable progeny lacking the c marker. Each of the four strains showed a characteristic dosage of the genes involved in the merodiploidy. Complementary strands of DNA's from these stable and unstable strains were resolved and homoduplex and heteroduplex hybrids made from the separated DNA strands were used as donors in genetic transformations. Activities of a normal marker (streptomycin resistance) and those involved in the heterozygosity (c, d and d  +) were quantitatively measured. From those heterodyplexes made up of opposite strands derived from a heterozygote and a stable strain, the normal marker is transferred efficiently, but the heterozygous markers are not. On the other hand, if both strands of a heteroduplex are derived from different heterozygotic strains, all markers can be transferred with usual efficiency to a stable recipient strain. The lowered efficiency in the former type of heteroduplex is attributed to an inhomology resulting from a tandem duplication in the merodiploid strains, and a postulated DNA repair process stimulated by it while in the form of the donor duplex. The inhomology probably includes (a) a microheterogeneity between the c site and the wild type locus, and (b) a more extensive incompatibility attributable to an extra segment of genome in a tandem duplication covering the c and d sites. The first of these inhomologies produces a lowered efficiency of transfer from all configurations of the particular d allele associated with the mutant c marker, and therefore accounts for the characteristic transfer patterns even from the native merodiploid DNA's.
Slow violence and corporate greening in the war on drugs in Colombia
Authors: Vélez-Torres Irene , Lugo-Vivas Diego
Published: January 2021

Next to a broader agrarian reform, the Peace Accord signed between the Revolutionary Armed Forces of Colombia (FARC-EP) and the Colombian Government (2016) was designed to support the voluntary substitution of illicit crops in an attempt to fight drug trafficking. In the municipality of Miranda (Northern Cauca), over 1300 peasant families agreed to eradicate their coca crops and stop their work in coca fields as part of the National Comprehensive Program for the Substitution of Illicit Crops (PNIS). Nearly three years later, the programme has shown little progress based on complementary evidence. First, it has only embraced 38% of the families who declared their will to replace illicit crops; and second, it has delayed commitments regarding access to land and financial and technical assistance for alternative projects. Based on extensive ethnographic fieldwork, this article brings an insightful and original political ecology perspective to environmental peacebuilding, showing that the promised transformation for marginalized peasant communities has been neglected. We argue that initial solutions for substitution have not only been redirected to benefit green corporate agrarian projects but have also been gradually abandoned by the state, creating different forms of slow environmental violence.
Super-resolution multi-reference alignment
Authors: Bendory Tamir , Jaffe Ariel , Leeb William , Sharon Nir , Singer Amit
Published: January 2021

We study super-resolution multi-reference alignment, the problem of estimating a signal from many circularly shifted, down-sampled and noisy observations. We focus on the low SNR regime, and show that a signal in ${\mathbb{R}}^M$ is uniquely determined when the number $L$ of samples per observation is of the order of the square root of the signal’s length ($L=O(\sqrt{M})$). Phrased more informally, one can square the resolution. This result holds if the number of observations is proportional to $1/\textrm{SNR}^3$. In contrast, with fewer observations recovery is impossible even when the observations are not down-sampled ($L=M$). The analysis combines tools from statistical signal processing and invariant theory. We design an expectation-maximization algorithm and demonstrate that it can super-resolve the signal in challenging SNR regimes.
Chlamydia trachomatis, Pelvic Inflammatory Disease, and Epithelial Ovarian Cancer
Authors: Paavonen Jorma , Turzanski Fortner Renee , Lehtinen Matti , Idahl Annika
Published: January 2021

Epidemiologic, clinical, molecular and translational research findings support an interrelationship between Chlamydia trachomatis, pelvic inflammatory disease (PID), and epithelial ovarian cancer (EOC). Overall, the link between C. trachomatis, PID, and EOC seems to be relatively weak, although nondifferential misclassification bias may have attenuated the results. The predominant tubal origin of EOC and the role of chronic inflammation in tumorigenesis suggest that the association is biologically plausible. Thus, C. trachomatis and PID may represent potential risk factors or risk markers for EOC. However, many steps in this chain of events are still poorly understood and need to be addressed in future studies. Research gaps include time of exposure in relation to the long-term consequences and lag time to EOC. Data of differential risk for EOC between chlamydial and nonchlamydial PID is also needed. Another major research gap has been the absence of high-performance biomarkers for C. trachomatis, PID, and EOC, as well as EOC precursors. Biomarkers for C. trachomatis and PID leading to increased risk of EOC should be developed. If the association is confirmed, C. trachomatis and PID prevention efforts may play a role in reducing the burden of EOC.
Prevalence and Predictors of Persistent Human Immunodeficiency Virus Viremia and Viral Rebound After Universal Test and Treat: A Population-Based Study
Authors: Grabowski M Kate , Patel Eshan U , Nakigozi Gertrude , Ssempijja Victor , Ssekubugu Robert , Ssekasanvu Joseph , Ndyanabo Anthony , Kigozi Godfrey , Nalugoda Fred , Gray Ronald H , Kalibbala Sarah , Serwadda David M , Laeyendecker Oliver , Wawer Maria J , Chang Larry W , Quinn Thomas C , Kagaayi Joseph , Tobian Aaron A R , Reynolds Steven J
Published: January 2021

Background

There are limited data on individual human immunodeficiency virus (HIV) viral load (VL) trajectories at the population-level after the introduction of universal test and treat (UTT) in sub-Saharan Africa.

Methods

Human immunodeficiency virus VLs were assessed among HIV-positive participants through 3 population-based surveys in 4 Ugandan fishing communities surveyed between November 2011 and August 2017. The unit of analysis was a visit-pair (2 consecutive person-visits), which were categorized as exhibiting durable VL suppression, new/renewed VL suppression, viral rebound, or persistent viremia. Adjusted relative risks (adjRRs) and 95% confidence intervals (CIs) of persistent viremia were estimated using multivariate Poisson regression.

Results

There were 1346 HIV-positive participants (n = 1883 visit-pairs). The population-level prevalence of durable VL suppression increased from 29.7% to 67.9% during UTT rollout, viral rebound declined from 4.4% to 2.7%, and persistent viremia declined from 20.8% to 13.3%. Younger age (15–29 vs 40–49 years; adjRR = 1.80; 95% CI = 1.19–2.71), male sex (adjRR = 2.09, 95% CI = 1.47–2.95), never being married (vs currently married; adjRR = 1.88, 95% CI = 1.34–2.62), and recent migration to the community (vs long-term resident; adjRR = 1.91, 95% CI = 1.34–2.73) were factors associated with persistent viremia.

Conclusions

Despite increases in durable VL suppression during roll out of UTT in hyperendemic communities, a substantial fraction of the population, whose risk profile tended to be younger, male, and mobile, remained persistently viremic.
Surgical residents’ opinions on international surgical residency in Flanders, Belgium
Authors: Willemse Gauthier , Raymenants Joren , Clement Céline , Herijgers Paul
Published: January 2021

Background

International electives benefit training of medical residents due to exposure to an increased scope of pathologies, improved physical examination skills, communication across cultural boundaries and more efficient resource utilization. Currently there is no mechanism for Belgian surgical residents to participate in international training opportunities and little research has addressed the international mobility of Belgian residents. The goal of this study was to examine the attitudes of Belgian residents towards international training among surgical residents.

Methods

An anonymous, structured electronic questionnaire was sent to a cohort of Belgian residents, including surgical residents, by e-mail and social media.

Results

In total, 342 respondents filled out the questionnaire out of a total of 5906 Belgian residents. The results showed that 334 of the residents came from Flanders (10.8%) and 8 came from French-speaking Brussels and Wallonia (0.28%). Surgical specialties represented 46% of respondents and included surgical, obstetric and anaesthesiology residents. The majority (98%) were interested in an international rotation, both in low- and middle-income countries (LMICs) and in high-income countries. A total of 84% were willing to conduct an international rotation during holidays and 91% would participate even when their international stay would not be recognised as part of their residency training. A minority (38%) had undertaken an international rotation in the past and, of those, 5% went to an LMIC.

Conclusion

The majority of surgical residents consider an international rotation as educationally beneficial, even though they are rarely undertaken. Our survey shows that in order to facilitate foreign rotations, Flemish universities and governmental institutions will have to alleviate the regulatory, logistical and financial constraints.
Does implementation of a tailored intervention increase adherence to a National Safety and Quality Standard? A study to improve delirium care
Authors: Oberai Tarandeep , Laver Kate , Woodman Richard , Crotty Maria , Kerkhoffs Gino , Jaarsma Ruurd
Published: January 2021

Background

Delirium is commonly detected in older people after hip fracture. Delirium is considered to be a multifactorial disorder that is often seen post-operatively (incidence ranging from 35% to 65%). Hospitals in Australia are required to meet eight standards including the comprehensive care standard to be able to maintain their accreditation. The standard includes actions related to falls, pressure injuries, nutrition, mental health, cognitive impairment and end-of-life care. Delirium prevention was identified as an area for improvement in our Orthopaedic unit in a Level 1 University Trauma Centre in Australia. This implementation research project aimed to understand the efficacy of a delirium prevention intervention within an existing orthopaedic speciality care system.

Objective

Implementation of the tailored intervention will increase adherence to National Safety and Quality Health Service Standards, thereby reducing rate of delirium.

Methods

In this study, we used an interrupted time series design to examine changes in practice over time in people admitted to hospital with a hip fracture. Clinical staff caring for patients with hip fracture in an acute care setting in Adelaide, South Australia, participated in the project. In brief, intervention included education, environmental restructuring, change champions, infographics and audit feedback reports. The primary outcome of interest was rate of delirium. The secondary outcome was compliance with the use of delirium 4AT screening tool, duration of delirium and hospital length of stay.

Results

The rate of change per month in patients with delirium decreased significantly by 19.2%. There was no significant change observed in trend for duration of delirium and length of hospital stay between pre-intervention and post-intervention phases. A significant increase in the use of screening tool was observed from 4.7% in the pre-intervention phase to 33.6% in the post-intervention phase.

Conclusion

Translation of evidence-based intervention model incorporating well-considered implementation strategies had a mixed impact on decreasing the rate of delirium. The scheduled hospital accreditation enhanced the use of validated screening tool to recognize delirium. This project highlights the importance of aligning implementation goals with the wider goals of the organization as well as making clinicians accountable by consistent auditing.
Development of a novel machine learning model to predict presence of nonalcoholic steatohepatitis
Authors: Docherty Matt , Regnier Stephane A , Capkun Gorana , Balp Maria-Magdalena , Ye Qin , Janssens Nico , Tietz Andreas , Löffler Jürgen , Cai Jennifer , Pedrosa Marcos C , Schattenberg Jörn M
Published: January 2021

Objective

To develop a computer model to predict patients with nonalcoholic steatohepatitis (NASH) using machine learning (ML).

Materials and Methods

This retrospective study utilized two databases: a) the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) nonalcoholic fatty liver disease (NAFLD) adult database (2004-2009), and b) the Optum® de-identified Electronic Health Record dataset (2007-2018), a real-world dataset representative of common electronic health records in the United States. We developed an ML model to predict NASH, using confirmed NASH and non-NASH based on liver histology results in the NIDDK dataset to train the model.

Results

Models were trained and tested on NIDDK NAFLD data (704 patients) and the best-performing models evaluated on Optum data (~3,000,000 patients). An eXtreme Gradient Boosting model (XGBoost) consisting of 14 features exhibited high performance as measured by area under the curve (0.82), sensitivity (81%), and precision (81%) in predicting NASH. Slightly reduced performance was observed with an abbreviated feature set of 5 variables (0.79, 80%, 80%, respectively). The full model demonstrated good performance (AUC 0.76) to predict NASH in Optum data.

Discussion

The proposed model, named NASHmap, is the first ML model developed with confirmed NASH and non-NASH cases as determined through liver biopsy and validated on a large, real-world patient dataset. Both the 14 and 5-feature versions exhibit high performance.

Conclusion

The NASHmap model is a convenient and high performing tool that could be used to identify patients likely to have NASH in clinical settings, allowing better patient management and optimal allocation of clinical resources.
Simultaneous Quantification of Pharmacologically Active Alkaloid Metabolites Colchicine and Gloriosine in Gloriosa Superba L. collected from Western Ghats (India) and Adjoining Areas for the Identification of Elite Chemotype(s)
Authors: Misra Ankita , Chaudhary Mridul Kant , Shukla Pushpendra , Srivastava Sharad
Published: January 2021

Background

Gloriosa superba is a valuable Ayurvedic medicinal plant and is in high demand in the world market for its colchicine content, which is used to treat gout.

Objective

The study aims (1) to record the metabolic variations in major bioactive metabolites, colchicine and gloriosine, in the natural populations of G. superba from Western Ghats and adjoining areas in India and (2) to develop HPTLC protocol for the identification of elite chemotypes of species and regulation of quality raw material, extract, and finished material.

Method

Simultaneous quantification of colchicine and gloriosine in 22 natural populations through validated HPTLC as per ICH guidelines.

Results

Colchicine and gloriosine were identified at Rf 0.51 ± 0.03 and 0.41 ± 0.05 and the content varied from 0.021 to 0.86% and 0.003 to 0.198%. The method was found linear at a concentration range of 0.1–0.7 µg/spot, and LOD (3.3 σ/S) and LOQ (10 σ/S) was 0.71 and 2.16 µg/spot. The method was precise in the concentration range of 100–300 ng/spot, with 98.29% and 101.12% recovery (% RSD) for colchicine and gloriosine. Subsequently, four elite chemotypes were identified based on cluster analysis of metabolite content.

Conclusion

The developed HPTLC method is linear, accurate, precise, and robust for simultaneous quantification of colchicine and gloriosine metabolite(s). Intraspecific metabolic variation was significant among the collected population, leading to the identification of four elite chemotypes.

Highlights

Colchicine is an industrially viable metabolite and is therefore quintessential to the development of an economical and analytical method to regulate the quality of raw material, extract, and finished products.
Genomic selection in American mink (Neovison vison) using a single-step genomic best linear unbiased prediction model for size and quality traits graded on live mink
Authors: Villumsen Trine M , Su Guosheng , Guldbrandtsen Bernt , Asp Torben , Lund Mogens S
Published: January 2021

Genomic selection relies on single-nucleotide polymorphisms (SNPs), which are often collected using medium-density SNP arrays. In mink, no such array is available; instead, genotyping by sequencing (GBS) can be used to generate marker information. Here, we evaluated the effect of genomic selection for mink using GBS. We compared the estimated breeding values (EBVs) from single-step genomic best linear unbiased prediction (SSGBLUP) models to the EBV from ordinary pedigree-based BLUP models. We analyzed seven size and quality traits from the live grading of brown mink. The phenotype data consisted of ~20,600 records for the seven traits from the mink born between 2013 and 2016. Genotype data included 2,103 mink born between 2010 and 2014, mostly breeding animals. In total, 28,336 SNP markers from 391 scaffolds were available for genomic prediction. The pedigree file included 29,212 mink. The predictive ability was assessed by the correlation (r) between progeny trait deviation (PTD) and EBV, and the regression of PTD on EBV, using 5-fold cross-validation. For each fold, one-fifth of animals born in 2014 formed the validation set. For all traits, the SSGBLUP model resulted in higher accuracies than the BLUP model. The average increase in accuracy was 15% (between 3% for fur clarity and 28% for body weight). For three traits (body weight, silky appearance of the under wool, and guard hair thickness), the difference in r between the two models was significant (P < 0.05). For all traits, the regression slopes of PTD on EBV from SSGBLUP models were closer to 1 than regression slopes from BLUP models, indicating SSGBLUP models resulted in less bias of EBV for selection candidates than the BLUP models. However, the regression coefficients did not differ significantly. In conclusion, the SSGBLUP model is superior to conventional BLUP model in the accurate selection of superior animals, and, thus, it would increase genetic gain in a selective breeding program. In addition, this study shows that GBS data work well in genomic prediction in mink, demonstrating the potential of GBS for genomic selection in livestock species.
Experiences and Perspectives on Spodoptera frugiperda (Lepidoptera: Noctuidae) Management in Sub-Saharan Africa
Authors: Njuguna Elizabeth , Nethononda Phophi , Maredia Karim , Mbabazi Ruth , Kachapulula Paul , Rowe Arielle , Ndolo Dennis
Published: January 2021

It has been over five years since the first report of an outbreak of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Africa. The highly invasive pest, native to the Americas, has since spread across the African continent attacking many crops and causing significant yield loss to Africa’s staple crop, maize. From the onset of the outbreak, there have been massive and varied responses from farmers, governments and nongovernmental organizations. This mini-review provides various perspectives on S. frugiperda control in sub-Saharan Africa, building on previously published evidence, and experiences of the authors. It also highlights new technologies and lessons learned so far from the S. frugiperda outbreaks in sub-Saharan Africa, based on which suggestions on possible integrated management approaches are proffered.
Response to Trimethoprim-Sulfamethoxazole in a Pediatric Hematopoietic Stem Cell Transplant Recipient With Disseminated Toxoplasmosis: A Case Report
Authors: Khan Aslam , Schwenk Hayden T , Kohlman Krystal , Bertaina Alice , Cho Stephanie , Montoya Jose G , Contopoulos-Ioannidis Despina
Published: January 2021

We describe the presentation and treatment of a patient who developed ongoing fever and diagnosed with disseminated toxoplasmosis post-hematopoietic stem cell transplantation. He was initially treated with trimethoprim-sulfamethoxazole (TMP-SMX) and there was dramatic improvement in his fever curve. He successfully completed a modified course of therapy.