bluuebunny/crossref_metadata_2025_split huggingface dataset:
DFT investigations of the unusual reactivity of 2‐pyridinecarboxaldehyde in base‐catalyzed aldol reactions with acetophenone
Authors: Wachter Nanette M. , Rani Neha , Zolfaghari Arghavan , Tarbox Haley , Mazumder Shivnath 
Published: January 2020

AbstractThe aldol reaction is recognized as an archetypal method to form carbon‐carbon bonds. Base‐catalyzed aldol reactions of aryl aldehydes with aryl methyl ketones typically produce condensation products (chalcones). However, 2‐pyridinecarboxaldehye, 2‐quinolinecarboxaldehyde, and 2‐ and 3‐fluorobenzaldehyde undergo tandem aldol‐Michael reactions with aryl enolates to yield conjugate addition products. To elucidate the different reactivities of aldol products formed in the reactions of benzaldehyde and 2‐pyridinecarboxaldehyde with the sodium enolate of acetophenone, density functional theory (DFT) calculations were performed to compare the energies of conformational isomers of the intermediates formed in the reaction, the energies of the corresponding condensation products, and the kinetic barriers to dehydration and conjugate addition. Computational results support the formation of the trans isomer of the condensation product in base‐catalyzed aldol reactions of either benzaldehyde or 2‐pyridinecarboxaldehyde with acetophenone. The susceptibility of the condensation product to conjugate addition is determined to result from the lower LUMO energy of trans‐1‐phenyl‐3‐(2‐pyridinyl)‐2‐propen‐1‐one. Consequently, the kinetic barrier for conjugate addition of a second equivalent of enolate with the condensation product of 2‐pyridinecarboxaldehyde is found to be significantly lower. Similar results were obtained for the reactions of fluorobenzaldehydes with aryl enolates.
Structural and functional characterization of the dominant negative P‐loop lysine mutation in the dynamin superfamily protein Vps1
Authors: Tornabene Bryan A. , Varlakhanova Natalia V. , Hosford Christopher J. , Chappie Joshua S. , Ford Marijn G. J. 
Published: January 2020

AbstractDynamin‐superfamily proteins (DSPs) are large self‐assembling mechanochemical GTPases that harness GTP hydrolysis to drive membrane remodeling events needed for many cellular processes. Mutation to alanine of a fully conserved lysine within the P‐loop of the DSP GTPase domain results in abrogation of GTPase activity. This mutant has been widely used in the context of several DSPs as a dominant‐negative to impair DSP‐dependent processes. However, the precise deficit of the P‐loop K to A mutation remains an open question. Here, we use biophysical, biochemical and structural approaches to characterize this mutant in the context of the endosomal DSP Vps1. We show that the Vps1 P‐loop K to A mutant binds nucleotide with an affinity similar to wild type but exhibits defects in the organization of the GTPase active site that explain the lack of hydrolysis. In cells, Vps1 and Dnm1 bearing the P‐loop K to A mutation are defective in disassembly. These mutants become trapped in assemblies at the typical site of action of the DSP. This work provides mechanistic insight into the widely‐used DSP P‐loop K to A mutation and the basis of its dominant‐negative effects in the cell.
RNA interference of tyrosine hydroxylase caused rapid mortality by impairing cuticle formation in Nilaparvata lugens (Hemiptera: Delphacidae)
Authors: Liu Shu H , Yang Bao J , Wang Ai Y , Luo Ju , Tang Jian 
Published: January 2020

AbstractBACKGROUNDThe application of RNA interference (RNAi) technique in controlling agricultural insect pests has been receiving much attention since the discovery of RNAi. The brown planthopper (BPH) Nilaparvata lugens, a notorious pest of rice, has evolved a high level of resistance to many kinds of insecticides. Tyrosine hydroxylase (Th) is an indispensable survival gene in holometabolous insects, playing key roles in cuticle tanning and immunity. In this study, we investigated whether Th could be used as a potential target in controlling N. lugens.RESULTSHere, we demonstrated that NlTh had a periodical expression pattern during molting with the highest level observed in epidermis. Dysfunction of NlTH by dsNlTh microinjection or 3‐IT feeding similarly caused rapid death of N. lugens. Compared with dsGFP control BPHs, dsNlTh injected BPHs (i) had cuticle pigmentation and sclerotizaton defects; (ii) had less endocuticle lamella in tergum integument; (iii) showed higher mortality during the molting process as a result of defective cuticle shedding; (iv) showed feeding disorders indicated by a low number of probe wound dots on rice; (v) had more vulnerable cuticle.CONCLUSIONThis study demonstrated that TH orthologues play a conservative and crucial role for exocuticle tanning in both holometabolous and hemimetabolous insects, and NlTh could be targeted for RNAi‐mediated BPH control. The rapid lethal phenotype of NlTH dysfunction BPHs partly induced by cuticle formation defects. © 2020 Society of Chemical Industry
Using gyroplane for application of Trichogramma spp. against the European corn borer in maize
Authors: Bzowska‐Bakalarz Małgorzata , Bulak Piotr , Bereś Paweł K. , Czarnigowska Agata , Czarnigowski Jacek , Karamon Bartłomiej , Pniak Michał , Bieganowski Andrzej 
Published: January 2020

AbstractBACKGROUNDAchieving sustainability of agricultural production is one of the key challenges for humanity. Minimizing the use of chemicals and replacing them with biological plant protection is, firstly, fully in line with the agriculture's development strategy and, secondly, confirmed to be achievable in practice. For instance, many researchers point to the potential of using Trichogramma spp. to control Ostrinia nubilalis in maize. However, the application methods for preparations containing Trichogramma spp. are still at the stage of development. So far, ground application proved time and energy consuming. Aerial application using ultralight aircraft is a new option.RESULTSThe present study presents the results of tests on the effectiveness of applying Trichogramma spp. from the board of an ultralight gyroplane. A 6‐year experiment was conducted on a maize monoculture located in south‐western Poland. The results indicate that the low‐height aerial application allows precise dosing and satisfactory distribution of the biopesticide. The efficacy of 60–85% (depending on the year) of the gyroplane‐based spraying operations was comparable with that observed for ground application.CONCLUSIONConsidering the speed and high efficiency of the treatment, using a gyroplane as a carrier of the biopesticide application system is a good alternative to the other methods. © 2020 Society of Chemical Industry
Unique continuation for the magnetic Schrödinger equation
Authors: Laestadius Andre , Benedicks Michael , Penz Markus 
Published: January 2020

AbstractThe unique‐continuation property from sets of positive measure is here proven for the many‐body magnetic Schrödinger equation. This property guarantees that if a solution of the Schrödinger equation vanishes on a set of positive measure, then it is identically zero. We explicitly consider potentials written as sums of either one‐body or two‐body functions, typical for Hamiltonians in many‐body quantum mechanics. As a special case, we are able to treat atomic and molecular Hamiltonians. The unique‐continuation property plays an important role in density‐functional theories, which underpins its relevance in quantum chemistry.
A rapid throughput technique to isolate pyrogenic carbon by hydrogen pyrolysis for stable isotope and radiocarbon analysis
Authors: Haig Jordahna , Ascough Philippa L. , Wurster Christopher M. , Bird Michael I. 
Published: January 2020

RationaleRapid, reliable isolation of pyrogenic carbon (PyC; also known as char, soot, black carbon, or biochar) for the determination of stable carbon isotope (δ13C) composition and radiocarbon (14C) dating is needed across multiple fields of research in geoscience, environmental science and archaeology. Many current techniques do not provide reliable isolation from contaminating organics and/or are relatively time‐consuming. Hydrogen pyrolysis (HyPy) does provide reliable isolation of PyC, but the current methodology is time consuming.MethodsWe explored the potential for subjecting multiple samples to HyPy analysis by placing up to nine individual samples in custom‐designed borosilicate sample vessels in a single reactor run. We tested for cross‐contamination between samples in the same run using materials with highly divergent radiocarbon activities (~0.04–116.3 pMC), δ13C values (−11.9 to −26.5‰) and labile carbon content. We determined 14C/13C using accelerator mass spectrometry and δ13C values using an elemental analyser coupled to a continuous flow isotope ratio mass spectrometer.ResultsVery small but measurable transfer between samples of highly divergent isotope composition was detectable. For samples having a similar composition, this cross‐contamination is considered negligible with respect to measurement uncertainty. For samples having divergent composition, we found that placing a sample vessel loaded with silica mesh adsorbent between samples eliminated measurable cross‐contamination in all cases for both 14C/13C and δ13C values.ConclusionsIt is possible to subject up to seven samples to HyPy in the same reactor run for the determination of radiocarbon content and δ13C value without diminishing the precision or accuracy of the results. This approach enables an increase in sample throughput of 300–600%. HyPy process background values are consistently lower than the nominal laboratory process background for quartz tube combustion in the NERC Radiocarbon Laboratory, indicating that HyPy may also be advantageous as a relatively ‘clean’ radiocarbon pre‐treatment method.
Phosphine detection in veterinary samples using headspace gas chromatography/tandem mass spectrometry with multiple reaction monitoring
Authors: Lehner Andreas F. , Johnson Margaret , Buchweitz John P. 
Published: January 2020

RationaleDetermination of phosphine exposure from zinc or aluminum phosphide fumigants continues to be a routine analytical requirement in veterinary forensic toxicology. There is a need for a more reliable and specific method than simple gas chromatography/mass spectrometry (GC/MS) analysis of sample solvent extracts, as GC/MS of extracts on capillary columns used for general screens involves significant interference from air peaks.MethodsGC/MS/MS headspace analysis of acid‐generated phosphine gas enabled study of the feasibility of devising multiple reaction monitoring (MRM) approaches to the determination of phosphine with greater specificity.ResultsCollision‐induced dissociation in GC/MS/MS showed that phosphine generated m/z 34 → 31, 32 and 33 ion transitions by sequential proton release as well as minor transitions m/z 34 → 47, 34 → 63 and 63 → 31.5 by intermolecular collisions and double charging. Study of the formation of these product ions enabled development of MRM settings for a highly useful headspace method for phosphine detection.ConclusionsThe method was validated over a working range of 5–100 ppm of phosphide generating phosphine gas which enabled retention of regular screen capillary columns without necessitating separation from air components. The method should have adequate sensitivity and reliability for veterinary toxicology laboratories confronting specimens from animals poisoned by crop fumigants.
Hybrid dynamic learning mechanism for multivariate time series segmentation
Authors: Wang Ling , Li Kang , Ma Qian , Lu YanRong 
Published: January 2020

AbstractTo improve the efficiency of segmentation methods for multivariate time series, a hybrid dynamic learning mechanism for such series' segmentation is proposed. First, an incremental clustering algorithm is used to automatically cluster variables of multivariate time series. Second, common factors are extracted from every cluster by a dynamic factor model as an ensemble description of the system. Third, this common factor series is segmented by dynamic programming. The proposed method can potentially segment multivariate time series and not only performs segmentation better on multivariate time series with a large number of variables but also improves the running accuracy and efficiency of the algorithm, especially when analyzing complex datasets.
Determination of haematological and biochemical parameters of Calf Saiga antelope (Saiga tatarica) living in the Gansu Endangered Animals Research Center
Authors: Du Xiaohua , Liu Xia , Mawolo James Blackar , Wang Haifang , Mi Xiaoyu , Dong Jianying , Li Qiao , Wen Yongqiang 
Published: January 2020

AbstractBackgroundThe Saiga antelope (Saiga tatarica) is native to Eurasia and is a member of the family Bovidae. Prior to 1920, the antelope had been extensively hunted for its horns, which were used in traditional Chinese medicine. Since 1920, the Saiga antelope has been protected because of this extensive hunting, which nearly led to its extinction.ObjectiveThe study evaluated haematological and biochemical parameters to provide references for the Calf Saiga antelope (S. tatarica). The study also sought to explore the mechanisms affecting these parameters in both genders of the Calf Saiga antelope.MethodsHaematological and biochemical parameters were collected from the Calf Saiga antelope. Haematological and biochemical parameters were analysed by the Coulter counter and Automatic analyser, respectively.ResultsThe average concentrations of female triglyceride levels showed significantly higher values than the significant concentrations of male. Female red blood cells and platelets concentrations were statistically significant than the significant concentrations of males. Magnesium female concentrations were also significantly higher than male values. Other parameters showed differences between males and females. ConclusionThe reported results show that haematological and biochemical characteristics varied among Calf Saiga antelope and other animals. The study results suggest that regardless of the factors, breed, the breeding environment, and climatic variables, haematological and biochemical variations can be triggered that can result in a reduction in the heat production needed for maintenance of homeothermy.
Gynaecological diagnosis by ultrasound and the measurement of urinary sex steroid hormones in female orangutans
Authors: Kinoshita Kodzue , Nakamura Tomoyuki , Kimura Koichi , Shimizu Mika , Kuze Noko , Ozaki Yasuhiko 
Published: January 2020

AbstractGynaecological diagnoses were carried in three adult female orangutans (Pongo spp.) using ultrasound, and their estrous states were estimated by measuring urinary sex steroid hormone concentrations using enzyme immunoassay. Ultrasound diagnosis revealed that the endometrial thickness and follicle size were correlated with the oestrogen‐3‐glucuronide concentrations in the follicular phase. In addition, administration of the ovulation inducer human chorionic gonadotropin (hCG) had the strongest effect on the pregnanediol‐3‐glucuronide (PdG) concentration when the follicle size was 22.3 mm, suggesting that the follicle reaches this size before ovulation. The similarity between this and the maximum ovarian follicle size in humans (approximately 20 mm) indicates that the ancestral reproductive characteristics may have been retained in these species.
Analytical and numerical studies for slip flows of a generalised Phan‐Thien–Tanner fluid
Authors: Ribau A. M. , Ferrás L. L. , Morgado M. L. , Rebelo M. , Afonso A. M. 
Published: January 2020

AbstractThis work presents analytical and numerical studies for pure Couette and combined Poiseuille‐Couette flows under slip. The fluid behaviour is described by the recently proposed viscoelastic model, known as the generalised simplified Phan‐Thien‐Tanner constitutive equation, that considers the Mittag‐Leffler function instead of the classical linear and exponential functions of the trace of the stress tensor, and provides one or two new fitting constants in order to achieve additional fitting flexibility. The solutions derived in this work allow a better understanding of the model and its influence on the slippery behaviour of some complex fluids, contributing in this way to improve the modeling of complex fluids.
ACL reconstruction combined with lateral monoloop tenodesis can restore intact knee laxity
Authors: Lagae Koen C. , Robberecht Joris , Athwal Kiron K. , Verdonk Peter C. M. , Amis Andrew A. 
Published: January 2020

Abstract
Purpose
An anterior cruciate ligament (ACL) injury is often combined with injury to the lateral extra-articular structures, which may cause a combined anterior and rotational laxity. It was hypothesised that addition of a ‘monoloop’ lateral extra-articular tenodesis (mLET) to an ACL reconstruction would restore anteroposterior, internal rotation and pivot-shift laxities better than isolated ACL reconstruction in combined injuries.

Method
Twelve cadaveric knees were tested, using an optical tracking system to record the kinematics through 0°–100° of knee flexion with no load, anterior and posterior translational forces (90 N), internal and external rotational torques (5 Nm), and a combination of an anterior translational (90 N) plus internal rotational load (5 Nm). They were tested intact, after sectioning the ACL, sectioning anterolateral ligament (ALL), iliotibial band (ITB) graft harvest, releasing deep ITB fibres, hamstrings tendon ACL reconstruction, mLET combined with ACL reconstruction, and isolated mLET. Two-way repeated-measures ANOVA compared laxity data across knee states and flexion angles. When differences were found, paired t tests with Bonferroni correction were performed.

Results
In the ACL-deficient knee, cutting the ALL significantly increased anterior laxity only at 20°–30°, and only significantly increased internal rotation at 50°. Additional deep ITB release significantly increased anterior laxity at 40°–90° and caused a large increase of internal rotation at 20°–100°. Isolated ACL reconstruction restored anterior drawer, but significant differences remained in internal rotation at 30°–100°. After adding an mLET there were no remaining differences with anterior translation or internal rotation compared to the intact knee. With the combined injury, isolated mLET allowed abnormal anterior translation and rotation to persist.

Conclusions
Cutting the deep fibres of the ITB caused large increases in tibial internal rotation laxity across the range of knee flexion, while cutting the ALL alone did not. With ACL deficiency combined with anterolateral deficiency, ACL reconstruction alone was insufficient to restore native knee rotational laxity. However, combining a ‘monoloop’ lateral extra-articular tenodesis with ACL reconstruction did restore native knee laxity.
Statistical properties of estimators for the log-optimal portfolio
Authors: Frahm Gabriel 
Published: January 2020

AbstractThe best constant re-balanced portfolio represents the standard estimator for the log-optimal portfolio. It is shown that a quadratic approximation of log-returns works very well on a daily basis and a mean-variance estimator is proposed as an alternative to the best constant re-balanced portfolio. It can easily be computed and the numerical algorithm is very fast even if the number of dimensions is high. Some small-sample and the basic large-sample properties of the estimators are derived. The asymptotic results can be used for constructing hypothesis tests and for computing confidence regions. For this purpose, one should apply a finite-sample correction, which substantially improves the large-sample approximation. However, it is shown that the impact of estimation errors concerning the expected asset returns is serious. The given results confirm a general rule, which has become folklore during the last decades, namely that portfolio optimization typically fails on estimating expected asset returns.
Fruiting bodies of selected edible mushrooms as a potential source of lovastatin
Authors: Kała Katarzyna , Kryczyk-Poprawa Agata , Rzewińska Aleksandra , Muszyńska Bożena 
Published: January 2020

AbstractAgaricus bisporus, Cantharellus cibarius, Imleria badia, and Lentinula edodes are among the most popular species of edible mushrooms in Poland. These edible mushrooms are an important source of biologically active substances exhibiting beneficial (e.g., antioxidant, antitumor, antimicrobial, anti-inflammatory) effects on the human body. The fruiting bodies of edible mushrooms are also a valuable source of lovastatin, which belongs to a group of compounds, called statins, commonly used as cholesterol-lowering drugs. Due to the presence of lovastatin, edible mushrooms can be useful in the prevention of hypercholesterolemia. Therefore, the aim of this study was to determine the content of lovastatin in the selected species of edible mushrooms and to evaluate its release into artificial digestive juices. This study was the first to determine the release of lovastatin into digestive juices after the extraction of materials obtained from edible mushrooms. The largest amount of lovastatin was found in the fruiting bodies of C. cibarius (67.89 mg/100 g d.w.), and the smallest in those of L. edodes (0.95 mg/100 g d.w.). The amount of lovastatin released from the extracts of the examined species into digestive juices was found to be relatively low. The highest content after incubation in artificial gastric juice was detected for the fruiting bodies of L. edodes (0.02 mg/100 g d.w.) and after incubation in the intestinal juice for the mycelium from the in vitro cultures of L. edodes (0.51 mg/100 g d.w.). Thus, the results of the present study showed that due to its ability to accumulate lovastatin from culture medium, L. edodes mycelium can be used to obtain a product with increased hypolipidemic activity.
Asymptotic Optimality of a First-Order Approximate Strategy for an Exponential Utility Maximization Problem with a Small Coefficient of Wealth-Dependent Risk Aversion
Authors: Delong Łukasz 
Published: January 2020

AbstractIn Delong [8] we investigate an exponential utility maximization problem for an insurer who faces a stream of non-hedgeable claims. We assume that the insurer’s risk aversion coefficient consists of a constant risk aversion and a small amount of wealth-dependent risk aversion. We apply perturbation theory and expand the equilibrium value function of the optimization problem on the parameter $$\epsilon $$
ϵ
controlling the degree of the insurer’s risk aversion depending on wealth. We derive a candidate for the first-order approximation to the equilibrium investment strategy. In this paper we formally show that the zeroth-order investment strategy $$\pi _0^*$$

π
0
∗

postulated by Delong (Math Methods Oper Res 89:73–113, 2019) performs better than any strategy $$\pi _0$$

π
0

when we compare the asymptotic expansions of the objective functions up to order $${\mathcal {O}}(1)$$

O
(
1
)

as $$\epsilon \rightarrow 0$$

ϵ
→
0

, and the first-order investment strategy $$\pi _0^*+\pi _1^*\epsilon $$

π
0
∗

+

π
1
∗

ϵ

postulated by Delong (Math Methods Oper Res 89:73–113, 2019) is the equilibrium strategy in the class of strategies $$\pi ^*_0+\pi _1\epsilon $$

π
0
∗

+

π
1

ϵ

when we compare the asymptotic expansions of the objective functions up to order $${\mathcal {O}}(\epsilon ^2)$$

O
(

ϵ
2

)

as $$\epsilon \rightarrow 0$$

ϵ
→
0

, where $$\epsilon $$
ϵ
denotes the parameter controlling the degree of the insurer’s risk aversion depending on wealth.