bluuebunny/crossref_metadata_2025 huggingface dataset:
Do Sustainability Standards Benefit Smallholder Farmers Also When Accounting For Cooperative Effects? Evidence from Côte d'Ivoire
Authors: Sellare Jorge , Meemken Eva‐Marie , Kouamé Christophe , Qaim Matin
Published: January 2020

Although many studies analyzed effects of sustainability standards—such as Fairtrade or Rainforest Alliance—on smallholder farmers in developing countries, most did not sufficiently account for systematic differences between certified and noncertified farmers. Certified farmers are typically organized in cooperatives. When sampling only from a small number of cooperatives, as previous studies did, it is not easy to disentangle certification effects from possible cooperative effects. Here, we address this shortcoming by randomly sampling from a large number of cooperatives, thus better capturing existing institutional heterogeneity. In particular, we collect and use data from cocoa farmers in Côte d'Ivoire who are organized in Fairtrade‐certified and noncertified cooperatives. Regression models with instrumental variables show that Fairtrade has positive and significant effects on cocoa yields, prices, and living standards. These effects remain significant also after controlling for cooperative characteristics, but the magnitude of the estimates changes. We draw two conclusions. First, in Côte d'Ivoire, Fairtrade certification benefits farmers economically. Second, and more generally, cooperative characteristics are jointly correlated with certification and relevant outcomes, which needs to be accounted for to avoid bias when evaluating the benefits of sustainability standards in the small farm sector.
Estimating Food Waste as Household Production Inefficiency
Authors: Yu Yang , Jaenicke Edward C.
Published: January 2020

Measuring food waste at the individual household level has been nearly impossible because comprehensive, current data on uneaten food do not exist. By using food acquisition data, this article employs a new approach to estimating household‐level food waste via a stochastic production frontier model in which food waste is identified as input inefficiency. For households in our data, the average household wastes 31.9% of the food it buys, and this figure, using survey weights, translates to annual U.S. consumer‐level food waste valued at $240 billion. In addition, by accommodating heterogeneous wasting behavior, we find that healthier diets and higher income lead to more household food waste, whereas lower household food security, food‐assistance program participation, and larger household sizes are associated with less food waste.
Effect of Compliance Cost on the Supply of Bank Credit to Agriculture: A Differential Approach
Authors: Moss Charles B. , Suh Dong Hee
Published: January 2020

The supply of credit to agriculture in the United States has been affected by a variety of financial regulations over time. One recent regulatory change is the Dodd‐Frank Act in 2010 that includes the Ability‐to‐Repay rule increasing the operating costs of banks. Although the rule increases the safety of the bank's portfolio, it requires more compliance costs to verify borrower's income status. Given that the verification of the ability to repay increases the costs of lending to all banks, this study examines the effects of bank regulations adding the compliance costs on small or community‐oriented banks. From the framework of multiproduct firm, we estimate the differential input demand and output supply systems to identify the banks' behavioral changes due to the compliance costs. The results indicate that changes in lending and input use have occurred due to the imposition of the compliance costs.
Irrigation Investment on an American Indian Reservation
Authors: Ge Muyang , Edwards Eric C. , Akhundjanov Sherzod B.
Published: January 2020

American Indian reservations have low incomes and high rates of poverty relative to adjacent communities, and the income gap appears to be even larger for Indian farmers. We examine the extent to which a lack of access to capital might explain these differences using irrigation systems as a proxy for on‐farm investment around the Uintah‐Ouray Indian Reservation in eastern Utah. Uintah land is held in trust by the US government, and farmers on this land face significant barriers to acquiring capital to invest in irrigation equipment and infrastructure. We use the boundaries from a 1905 land allotment as a natural experiment, employing both sharp and fuzzy regression discontinuity designs to explore whether agricultural land use, irrigation levels, irrigation investment, and crop choice differ across the boundary. The original allocation provided similar land in the immediate neighborhood around its borders, and our results suggest that today tribal trust land is farmed and irrigated at rates similar to adjacent land. However, conditional on being irrigated, tribal trust land is around thirty‐two percentage points less likely to utilize capital‐intensive sprinkler irrigation, and up to ten percentage points less likely to grow high‐value crops. Trust ownership, which is characterized by cumbersome bureaucratic processes, limits on agricultural lease flexibility, and the inability to use land as collateral to acquire loans, is a likely explanation for the observed differences.
The Power of Stories: Narratives and Information Framing Effects in Science Communication
Authors: Yang Yang , Hobbs Jill E.
Published: January 2020

This article explores information framing effects by comparing the effectiveness of using logical‐scientific versus narrative information to communicate with consumers about a new biotechnology application (gene editing). Using data from an online survey of 804 Canadian adults, a discrete choice experiment elicits preferences for diverse novel food attributes and technologies, with respondents randomly assigned to different information conditions. We construct a logical‐scientific information condition, written in a scientific style using the passive voice with generalized and impersonal language and attributed to either a government agency or a scientific organization. In contrast, we frame the narrative‐style information condition as a story, using a lively and vivid personal style, and attributed to either a science journalist or a consumer blogger. Data are analyzed using multinomial logit and random parameters logit models. We find that the information format (logical‐scientific vs. narrative) matters: narratives help reduce negative perceptions regarding agricultural and food technologies. We also examine factors that predispose consumers to seek logical‐scientific versus narrative information sources.
Novel Recessive TNNT1 Congenital Core‐Rod Myopathy in French Canadians
Authors: Pellerin David , Aykanat Asli , Ellezam Benjamin , Troiano Emily C. , Karamchandani Jason , Dicaire Marie‐Josée , Petitclerc Marc , Robertson Rebecca , Allard‐Chamard Xavier , Brunet Denis , Konersman Chamindra G. , Mathieu Jean , Warman Chardon Jodi , Gupta Vandana A. , Beggs Alan H. , Brais Bernard , Chrestian Nicolas
Published: January 2020

Objective

Recessive null variants of the slow skeletal muscle troponin T1 (TNNT1) gene are a rare cause of nemaline myopathy that is fatal in infancy due to respiratory insufficiency. Muscle biopsy shows rods and fiber type disproportion. We report on 4 French Canadians with a novel form of recessive congenital TNNT1 core‐rod myopathy.

Methods

Patients underwent full clinical characterization, lower limb magnetic resonance imaging (MRI), muscle biopsy, and genetic testing. A zebrafish loss‐of‐function model using morpholinos was created to assess the pathogenicity of the identified variant. Wild‐type or mutated human TNNT1 mRNAs were coinjected with morpholinos to assess their abilities to rescue the morphant phenotype.

Results

Three adults and 1 child shared a novel missense homozygous variant in the TNNT1 gene (NM_003283.6: c.287T > C; p.Leu96Pro). They developed from childhood very slowly progressive limb‐girdle weakness with rigid spine and disabling contractures. They suffered from restrictive lung disease requiring noninvasive mechanical ventilation in 3 patients, as well as recurrent episodes of rhabdomyolysis triggered by infections, which were relieved by dantrolene in 1 patient. Older patients remained ambulatory into their 60s. MRI of the leg muscles showed fibrofatty infiltration predominating in the posterior thigh and the deep posterior leg compartments. Muscle biopsies showed multiminicores and lobulated fibers, rods in half the patients, and no fiber type disproportion. Wild‐type TNNT1 mRNA rescued the zebrafish morphants, but mutant transcripts failed to do so.

Interpretation

This study expands the phenotypic spectrum of TNNT1 myopathy and provides functional evidence for the pathogenicity of the newly identified missense mutation. ANN NEUROL 2020;87:568–583
Mitochondrial‐DNA‐Targeted IrIII‐Containing Metallohelices with Tunable Photodynamic Therapy Efficacy in Cancer Cells
Authors: Li Xuezhao , Wu Jinguo , Wang Lei , He Cheng , Chen Liyong , Jiao Yang , Duan Chunying
Published: January 2020

The development of DNA‐targeted photodynamic therapy (PDT) agents for cancer treatment has drawn substantial attention. Herein, the design and synthesis of dinuclear IrIII‐containing luminescent metallohelices with tunable PDT efficacy that target mitochondrial DNA in cancer cells are reported. The metallohelices are fabricated using dynamic imine‐coupling chemistry between aldehyde end‐capped fac‐Ir(ppy)3handles and linear alkanediamine spacers, followed by reduction of the imine linkages. The length and odd–even character of the diamine alkyl linker determined the stereochemistry (helicates vs. mesocates). Compared to the helicates, the mesocates exhibit improved apoptosis‐induction upon white‐light irradiation. Molecular docking studies indicate that the mesocate with a proper length of diamine spacers shows stronger affinity for the minor groove of DNA. This study highlights the potential of DNA‐targeting IrIII‐containing metallohelices as PDT agents.
Modulation of Prins Cyclization by Vibrational Strong Coupling
Authors: Hirai Kenji , Takeda Rie , Hutchison James A. , Uji‐i Hiroshi
Published: January 2020

Light‐molecule strong coupling has emerged within the last decade as a new method to control chemical reactions. A few years ago it was discovered that chemical reactivity could be altered by vibrational strong coupling (VSC). Only a limited number of reactions have been investigated under VSC to date, including solvolysis and deprotection reactions. Here the effect of VSC on a series of aldehydes and ketones undergoing Prins cyclization, an important synthetic step in pharmaceutical chemistry, is investigated. A decrease of the second‐order rate constant with VSC of the reactant carbonyl stretching groups is observed. We also observe an increased activation energy due to VSC, but proportional changes in activation enthalpy and entropy, suggesting no substantive change in reaction pathway. The addition of common cycloaddition reactions to the stable of VSC‐modified chemical reactions is another step towards establishing VSC as a genuine tool for synthetic chemistry.
Intrinsically Low Thermal Conductivity and High Carrier Mobility in Dual Topological Quantum Material, n‐Type BiTe
Authors: Samanta Manisha , Pal Koushik , Waghmare Umesh V. , Biswas Kanishka
Published: January 2020

A challenge in thermoelectrics is to achieve intrinsically low thermal conductivity in crystalline solids while maintaining a high carrier mobility (μ). Topological quantum materials, such as the topological insulator (TI) or topological crystalline insulator (TCI) can exhibit high μ. Weak topological insulators (WTI) are of interest because of their layered hetero‐structural nature which has a low lattice thermal conductivity (κlat). BiTe, a unique member of the (Bi2)m(Bi2Te3)n homologous series (m:n=1:2), has both the quantum states, TCI and WTI, which is distinct from the conventional strong TI, Bi2Te3 (where m:n=0:1). Herein, we report intrinsically low κlat of 0.47–0.8 W m−1 K−1 in the 300–650 K range in BiTe resulting from low energy optical phonon branches which originate primarily from the localized vibrations of Bi bilayer. It has high μ≈516 cm2 V−1 s−1 and 707 cm2 V−1 s−1 along parallel and perpendicular to the spark plasma sintering (SPS) directions, respectively, at room temperature.
Electron Configuration Modulation of Nickel Single Atoms for Elevated Photocatalytic Hydrogen Evolution
Authors: Jin Xixiong , Wang Rongyan , Zhang Lingxia , Si Rui , Shen Meng , Wang Min , Tian Jianjian , Shi Jianlin
Published: January 2020

The emerging metal single‐atom catalyst has aroused extensive attention in multiple fields, such as clean energy, environmental protection, and biomedicine. Unfortunately, though it has been shown to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date owing to the lack of deep insight on electronic level. Now, partially oxidized Ni single‐atom sites were constructed in polymeric carbon nitride (CN), which elevates the photocatalytic performance by over 30‐fold. The 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons, which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation, and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.
Determination of Complex Small‐Molecule Structures Using Molecular Alignment Simulation
Authors: Ibáñez de Opakua Alain , Klama Frederik , Ndukwe Ikenna E. , Martin Gary E. , Williamson R. Thomas , Zweckstetter Markus
Published: January 2020

Correct structural assignment of small molecules and natural products is critical for drug discovery and organic chemistry. Anisotropy‐based NMR spectroscopy is a powerful tool for the structural assignment of organic molecules, but it relies on the utilization of a medium that disrupts the isotropic motion of molecules in organic solvents. Here, we establish a quantitative correlation between the atomic structure of the alignment medium, the molecular structure of the small molecule, and molecule‐specific anisotropic NMR parameters. The quantitative correlation uses an accurate three‐dimensional molecular alignment model that predicts residual dipolar couplings of small molecules aligned by poly(γ‐benzyl‐l‐glutamate). The technique facilitates reliable determination of the correct stereoisomer and enables unequivocal, rapid determination of complex molecular structures from extremely sparse NMR data.
Facile preparation of a crosslinked hydrophilic UHMWPE membrane
Authors: Fei Zhengdong , Ying Songsong , Fan Ping , Chen Feng , Haque Enamul , Zhong Mingqiang
Published: January 2020

Ultra high molecular weight polyethylene (UHMWPE) filters are widely used in water treatment. In the present work, a facile crosslinking technique is first applied to a UHMWPE flat membrane as a model to realize long‐lasting hydrophilicity and improved water treatment efficiency. In the presence of a crosslinker, N, N′‐methylene bisacrylamide (MBA), 2‐hydroxyethyl methacrylate (HEMA), a hydrophilic modifier, is soaked into the surface of UHMWPE particles by blending. Then, a crosslinking reaction occurs during the initial sintering stage. Finally, sintering is completed at high temperature and pressure. The FTIR and SEM results show that HEMA is successfully crosslinked on the UHMWPE particle surface. Compared to a pristine membrane, the crosslinked UHMWPE flat membrane presents a lower water contact angle and is more rapidly penetrated by water. As a result, the crosslinked membrane can realize pressureless filtration. Another meaningful result is that the water flux recovery rate (FRR) is extremely high both for BSA and sludge filtration tests. Also a parameter K of 1 was obtained to represent the efficiency of the membrane treatment of water under pressureless conditions. These findings demonstrate that the crosslinking strategy is an effective method for realizing long‐lasting hydrophilicity and is very promising for UHMWPE filters and other engineering applications.
Development of chloroplast microsatellite markers for giant ragweed (Ambrosia trifida)
Authors: Sharma Himanshu , Hyvönen Jaakko , Poczai Péter
Published: January 2020

Premise

Plant invasions are increasing globally, and extensive study of the genetic background of the source and invading populations is needed to understand such biological processes. For this reason, chloroplast microsatellite markers were identified to explore the genetic diversity of the noxious weed Ambrosia trifida (Asteraceae).

Methods and Results

The complete chloroplast genome of A. trifida was mined for microsatellite loci, and 15 novel chloroplast primers were identified to assess the genetic diversity of 49 Ambrosia samples. The number of alleles amplified ranged from two to six, with an average of 3.2 alleles per locus. Shannon's information index varied from 0.305 and 1.467, expected heterozygosity ranged from 0.178 to 0.645, and the polymorphism information content value ranged from 0.211 to 0.675 (average 0.428). The cross‐species transferability of the 15 microsatellite loci was also evaluated in four related Ambrosia species (A. artemisiifolia, A. maritima, A. psilostachya, and A. tenuifolia).

Conclusions

The novel chloroplast microsatellite markers developed in the current study demonstrate substantial cross‐species transferability and will be helpful in future genetic diversity studies of A. trifida and related species.
Targeting apoptosis signal‐regulating kinase 1 in acute and chronic kidney disease
Authors: Tesch Greg H. , Ma Frank Y. , Nikolic‐Paterson David J.
Published: January 2020

Apoptosis signal‐regulating kinase 1 (ASK1) is a member of the mitogen‐activated protein kinase (MAP3K) family which acts as an upstream regulator for the activation of p38 MAPK and c‐Jun N‐terminal kinase (JNK). Experimental studies have demonstrated a pathogenic role for p38 MAPK and JNK activation in a number of kidney disease models; however, clinical studies targeting these kinases directly have been problematic due to their role in homeostatic functions. In comparison, ASK1 is activated in pathological states and is not essential for homeostatic functions, suggesting that ASK1 may be a safe and effective therapeutic target to inhibit p38 MAPK and JNK signaling in disease. Animal model studies using Ask1 gene deficient mice or a selective ASK1 inhibitor have demonstrated that ASK1 blockade is effective in a variety of acute and chronic kidney diseases; preventing cell injury, inflammation, fibrosis, albuminuria, and renal function impairment. Positive outcomes from these experimental studies have led to the current evaluation of an ASK1 inhibitor in patients with moderate to advanced diabetic kidney disease. This review summarizes the preclinical studies of ASK1 blockade in models of acute and chronic kidney injury and a clinical study examining ASK1 inhibitor treatment in diabetic kidney disease.
Constrained adaptive backstepping control of a semi‐active suspension considering suspension travel limits
Authors: Yıldız Ali Suat , Sivrioğlu Selim
Published: January 2020

In this article, a new constrained adaptive backstepping control design is presented for vibration suppression of the quarter car suspension system equipped with a magnetorheological (MR) damper. In the controller design, parametric uncertainties related to suspension parameter and the semi‐active actuator are considered. Also, the proposed controller is investigated, along with the designed road profiles based on the International Standard Organization (ISO) 8608 classification and tested under different speed conditions. The effectiveness of the proposed controller has been validated through comparisons with uncontrolled, passive, and separately designed adaptive control cases. According to the simulation and experimental results, the proposed control approach improves ride comfort and ride safety without violating suspension rattle space constraint despite the uncertainties in suspension parameters.
Identification of a Novel Oxadiazole Inhibitor of Mammalian Target of Rapamycin
Authors: Lim Sunwoo , Lee Hyomin , Kim Euijung , Hur Wooyoung
Published: January 2020

We performed a biochemical screen against mTOR using in‐house small molecule library. Two novel, structurally distinct hits were identified. Among them, a novel oxadiazole scaffold compound (2) suppressed the phosphorylation of both S6K1 and Akt1 in HeLa cells. Docking study suggested that 2 is ATP‐competitive and shows a pi‐pi interaction with Trp2239 and hydrogen bonds with Trp2239 and Thr2245. Through derivatization, a slightly more potent analogue (2a) was identified with IC50 of 9.6 μM. Our study provides a starting point for discovery of novel potent mTOR inhibitors.
Promoting corporate sustainability in small and medium‐sized enterprises: Key determinants of intermediary performance in Africa
Authors: Quartey Samuel Howard , Oguntoye Olamide
Published: January 2020

This study explores the key determinants of intermediary performance in promoting corporate sustainability in small and medium‐sized enterprises in Africa. Despite being a critical link in the delivery of sustainability support services to small and medium‐sized enterprises, intermediaries have only received limited research attention. Research exploring intermediaries of corporate sustainability in small and medium‐sized enterprises have focused broadly on their roles but narrowly on performance. Those exploring intermediary performance have often focused on larger companies, sometimes, neglecting the specifics of small and medium‐sized enterprises, especially in African countries. Improving intermediary performance in promoting corporate sustainability requires an in‐depth understanding of the factors that determine their performance. As a qualitative study, interview responses from 32 experts working in National Cleaner Production Centres in four African countries were analysed using inductive thematic approach. The findings suggest that programme constraints, external profile, small and medium‐sized enterprises context, impact strategy, and service networks are the key determinants of intermediary performance in promoting corporate sustainability in small and medium‐sized enterprises. These determinants facilitate and inhibit intermediaries’ ability to promote corporate sustainability in small and medium‐sized enterprises. The implications concern the need for intermediaries and small and medium‐sized enterprises to manage these determinants in promoting corporate sustainability.
Does it pay to be green? A disaggregated analysis of U.S. firms with green patents
Authors: Hoang Thi‐Hong‐Van , Przychodzen Wojciech , Przychodzen Justyna , Segbotangni Elysé A.
Published: January 2020

The objective of this paper is to investigate the relationship between environmental performance and financial performance on a sample of 361 U.S. firms over the 2007–2016 period. We contribute to the literature by considering firms active in sustainable innovations by obtaining green patents. We also contribute to the literature by using disaggregated measures of environmental performance collected from the Bloomberg ESG database, including environmental disclosure score, greenhouse gas emissions, waste emissions and water use. Panel data regressions' results show that environmental transparency positively influences current accounting and stock market performance, but negatively influences the return on capital employed. Furthermore, lower pollution emissions tend to improve the current return on assets, while being harmful for the efficiency of long‐term capital employment at the same time. The empirical results also indicate that the Global Financial Crisis (2007–2010) increased the environmental transparency of firms with green patents but negatively impacted their price to earnings ratio. At the same time, lower waste disposal diminishes stock valuation while the opposite is true with water use. Taken together, our results suggest that environmental transparency and greenhouse gas emissions generally appear to be the most important environmental variables influencing financial performance, with increasing importance attributed to them by the market after the global crisis period.
Pyrrolic and Dipyrrolic Chlorophyll Degradation Products in Plants and Herbivores
Authors: Ritter Marcel , Oetama Vincensius S. P. , Schulze Daniel , Muetzlaff Katrin , Meents Anja K. , Seidel Raphael A. , Görls Helmar , Westerhausen Matthias , Boland Wilhelm , Pohnert Georg
Published: January 2020

The degradation of chlorophyll, the omnipresent green pigment, has been investigated intensively over the last 30 years resulting in many elucidated tetrapyrrolic degradation products. With a comparison to the degradation of the structurally similar heme, we hereby propose a novel additional chlorophyll degradation mechanism to mono‐ and dipyrrolic products. This is the first proof of the occurrence of a family of mono‐ and dipyrrols in leaves that are previously only known as heme degradation products. This product family is also found in spit and feces of herbivores with specific metabolomic patterns reflecting the origin of the samples. Based on chromatographic and mass spectrometric evidence as well as on mechanistic considerations we also suggest several tentative new degradation products. One of them, dihydro BOX A, was fully confirmed as a novel natural product by synthesis and comparison of its spectroscopic data.
Palladium Complexes Based on Ylide‐Functionalized Phosphines (YPhos): Broadly Applicable High‐Performance Precatalysts for the Amination of Aryl Halides at Room Temperature
Authors: Tappen Jens , Rodstein Ilja , McGuire Katie , Großjohann Angela , Löffler Julian , Scherpf Thorsten , Gessner Viktoria H.
Published: January 2020

Palladium allyl, cinnamyl, and indenyl complexes with the ylide‐substituted phosphines Cy3P+−C−(R)PCy2 (with R=Me (L1) or Ph (L2)) and Cy3P+−C−(Me)PtBu2 (L3) were prepared and applied as defined precatalysts in C−N coupling reactions. The complexes are highly active in the amination of 4‐chlorotoluene with a series of different amines. Higher yields were observed with the precatalysts in comparison to the in situ generated catalysts. Changes in the ligand structures allowed for improved selectivities by shutting down β‐hydride elimination or diarylation reactions. Particularly, the complexes based on L2 (joYPhos) revealed to be universal precatalysts for various amines and aryl halides. Full conversions to the desired products are reached mostly within 1 h reaction time at room temperature, thus making L2 to one of the most efficient ligands in C−N coupling reactions. The applicability of the catalysts was demonstrated for aryl chlorides, bromides and iodides together with primary and secondary aryl and alkyl amines, including gram‐scale applications also with low catalyst loadings of down to 0.05 mol %. Kinetic studies further demonstrated the outstanding activity of the precatalysts with TOF over 10.000 h−1.
Three‐Dimensional Carbon Framework Anchored Polyoxometalate as a High‐Performance Anode for Lithium‐Ion Batteries
Authors: Jia Xueying , Wang Jiaxin , Hu Hanbin , Song Yu‐Fei
Published: January 2020

Recently, it has become very important to develop cost‐effective anode materials for the large‐scale use of lithium‐ion batteries (LIBs). Polyoxometalates (POMs) have been considered as one of the most promising alternatives for LIB electrodes owing to their reversible multi‐electron‐transfer capacity. Herein, Keggin‐type [PMo12O40]3− (donated as PMo12) clusters are anchored onto a 3D microporous carbon framework derived from ZIF‐8 through electrostatic interactions. The PMo12 clusters can be immobilized steadily and uniformly on the carbon framework, which provides enhanced electrical conductivity and high stability. Compared with PMo12 itself, the as‐prepared novel 3D Carbon‐PMo12 composite displays a significantly improved Li‐ion storage performance as an LIB anode, with excellent reversible specific capacity and rate capacity, as well as high cycling performance (discharge capacity of 985 mA h g−1 after 200 cycles), which are superior to other POM‐based anode materials reported so far. The high performance of the Carbon‐PMo12 composite can be attributed to the 3D conductive network with fast electron transport, high ratio of pseudocapacitive contribution, and evenly distributed PMo12 clusters with reversible 24‐electron transfer capacity. This work offers a facile way to explore novel LIB anodes consisting of electroactive molecule clusters.
Synthesis of enantiopure (S)‐6‐chlorochroman‐4‐ol using whole‐cell Lactobacillus paracasei biotransformation
Authors: Şahin Engin
Published: January 2020

Chromane, which has a fused cyclic structure, is a significant molecule that can be found in the structure of many important compounds. Lactobacillus paracasei BD101 was demonstrated as whole‐cell biocatalyst for the synthesis of (S)‐6‐chlorochroman‐4‐ol with immense enantioselectivity. The conditions of asymmetric reduction were optimized one factor by one factor using L paracasei BD101 to achieve enantiomerically pure product and complete conversion. Using these obtained optimization conditions, asymmetric reduction of 6‐chlorochroman‐4‐one was performed under environmentally friendly conditions; 6‐chlorochroman‐4‐one, having a fused cyclic structure as previously noted to be difficult to asymmetric reduction with biocatalysts, was enantiomerically reduced to (S)‐6‐chlorochroman‐4‐ol with an enantiomeric excess >99% on a high gram scale. This study is the first example in the literature for the enantiopure synthesis of (S)‐6‐chlorochroman‐4‐ol using a biocatalyst. Also notably, the optical purity of (S)‐6‐chlorochroman‐4‐ol obtained in this study through asymmetric bioreduction using whole‐cell biocatalyst is the highest value in the literature. In this study, (S)‐6‐chlorochroman‐4‐ol was produced on a gram scale by an easy, inexpensive, and environmentally friendly method, which has shown the production of valuable chiral precursors for drug synthesis and other industrial applications. This study provides a convenient method for the production of (S)‐6‐chlorochroman‐4‐ol, which can meet the industrial green production demand of this chiral secondary alcohol.
High performing multimedia transmission approach based on QoS support and admission control over IEEE 802.11e networks
Authors: Al‐Maqri Mohammed A. , Mansoor Ali Mohammed , Sabri Aznul Qalid , Ravana Sri Devi , Yaseein Hussein Soubhi
Published: January 2020

Hybrid coordination function controlled channel access (HCCA) is a medium to enhance quality of service (QoS) via the IEEE 802.11e standard. The main limitation of HCAA is that it is only efficient for constant bit rate (CBR) applications. This is due to the nature of its scheduler that allocates transmission opportunities (TXOPs) based on traffic stream (TS) specifications (TSPECs) that are determined during the traffic setup time. Variable bit rate (VBR) traffics used in HCCA have nondeterministic profile, making it not optimally and efficiently supported by HCCA. The result of this inefficiency is a deterioration of the transmission performance of multimedia data as well as a drop in the number of served QoS video traffics. We propose a novel approach to deal with this issue, which is the feedback‐based admission control unit (FACU). FACU works by optimizing the usage of extra bandwidth to ensure optimal transmission performance of multimedia data. FACU achieves this by exploiting piggybacked information concerning sequential video frames in order to accurately assign the TXOP. The proposed approach is evaluated by utilizing various video sequences. It is demonstrated that FACU maximizes the overall number of video streams and optimizes the overall usage of the network without having any adverse effects on the QoS constraints determined.
An energy‐efficient clustering and multipath routing for mobile wireless sensor network using game theory
Authors: Thandapani Preethiya , Arunachalam Muthukumar , Sundarraj Durairaj
Published: January 2020

Most of the current generation sensor nodes of mobile wireless sensor network (MWSN) are designed to have heterogeneous mobility to adapt itself in the applied environment. Energy optimization in MWSN with heterogeneous mobility is very challenging task. In this paper, a heterogeneous game theoretical clustering algorithm called mobile clustering game theory–1 (MCGT‐1) is proposed for energy optimization in a heterogeneous mobile sensor environment. Energy optimization is achieved through energy‐efficient cluster head election and multipath routing in the network. A heterogeneous clustering game is modelled with varying attributes and located an asymmetric equilibrium condition for a symmetric game with mixed strategies. The real‐time parameters, namely, predicted remaining energy, distance between a base station and nodes, distance between nodes, and mobility speed, were used to calculate the probability to elect the cluster head (CH). The efficient multipath routing is achieved through prior energy prediction strategy. It has mitigated the generation of “hot spots,” reducing its delay and improving the overall residual energy of the network. Simulation results showed that the average lifetime of MCGT‐1 has increased by 6.33 %, 13.1% and 14.2% and the PDR has improved by 4.8%,11.8%, and 17.2% than MCGT, LEACH‐ME and LEACH‐M respectively. The hot spot delay is reduced to 0.063025 seconds, improving the efficiency of the network.
2,6‐Bis(diazaboryl)pyridine – A Ligand with Hemilabile Donor and Lewis Acid Functionalities
Authors: Schröder Jan , Böttcher Tobias
Published: January 2020

Invited for the cover of this issue is the group of Tobias Böttcher from Universität Freiburg, Germany. The cover image shows the similarity of the chemistry presented to a game of Tetris.
The impact of internal waves on upper continental slopes: insights from the Mozambican margin (southwest Indian Ocean)
Authors: Miramontes Elda , Jouet Gwenael , Thereau Estelle , Bruno Miguel , Penven Pierrick , Guerin Charline , Le Roy Pascal , Droz Laurence , Jorry Stephan J. , Hernández‐Molina F. Javier , Thiéblemont Antoine , Silva Jacinto Ricardo , Cattaneo Antonio
Published: January 2020

Evidences of sedimentation affected by oceanic circulation, such as nepheloid layers and contourites are often observed along continental slopes. However, the oceanographic processes controlling sedimentation along continental margins remain poorly understood. Multibeam bathymetry and high‐resolution seismic reflection data revealed a contourite depositional system in the Mozambican upper continental slope composed of a contourite terrace (a surface with a gentle seaward slope dominated by erosion) and a plastered drift (a convex‐shape sedimentary deposit). A continuous alongslope channel and a field of sand dunes (mainly migrating upslope), formed during Holocene, were identified in the contourite terrace at the present seafloor. Seismic reflection data of the water column show internal waves and boluses propagating in the pycnocline near the upper slope. The channel and the dunes are probably the result of the interaction of the observed internal waves with the seafloor under two different conditions. The alongslope channel is located in a zone where intense barotropic tidal currents may arrest internal solitary waves, generating a hydraulic jump and focused erosion. However, upslope migrating dunes may be formed by bottom currents induced by internal solitary waves of elevation propagating landwards in the pycnocline. These small‐scale sedimentary features generated by internal waves are superimposed on large‐scale contouritic deposits, such as plastered drifts and contourite terraces, which are related to geostrophic currents. These findings provide new insights into the oceanographic processes that control sedimentation along continental margins that will help interpretation of palaeoceanographic conditions from the sedimentary record. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd
Central pathology review of salivary gland adenoid cystic carcinoma
Authors: Ueda Kaori , Murase Takayuki , Nagao Toshitaka , Kusafuka Kimihide , Urano Makoto , Yamamoto Hidetaka , Nakaguro Masato , Taguchi Ken‐ichi , Masaki Ayako , Hirai Hideaki , Kawakita Daisuke , Tsukahara Kiyoaki , Hato Naohito , Nagao Toru , Fujimoto Yasushi , Sakurai Kazuo , Hanai Nobuhiro , Kano Satoshi , Onitsuka Tetsuro , Okami Kenji , Nibu Ken‐ichi , Tada Yuichiro , Kawata Ryo , Inagaki Hiroshi
Published: January 2020

Background

To assess the role of a central pathology review in the diagnosis of salivary gland adenoid cystic carcinoma (AdCC).

Methods

Surgically resected salivary gland tumors diagnosed as AdCC (n = 219) in 15 reference hospitals in Japan were subjected to a retrospective pathological re‐evaluation.

Results

After the review, the AdCC diagnosis was revised in 21/219 cases (9.6%). The six benign tumors (2.7%) comprised five basal cell adenomas and one pleomorphic adenoma, and among these six patients, three received postoperative radiotherapy. The remaining 15 malignant tumors (6.8%) comprised nine basal cell adenocarcinomas and six other carcinomas. All revised basal cell adenoma/adenocarcinoma cases were of rare cribriform variants.

Conclusions

A significant proportion of AdCC pathology reports were revised after the central pathology review. It should be emphasized that the greatest attention should be paid in differentiating AdCC from cribriform variant basal cell adenoma/adenocarcinoma, which is very rare in salivary gland tumors.
Socioeconomic inequalities in cancer mortality: Is Costa Rica an exception to the rule?
Authors: Fantin Romain , Santamaría‐Ulloa Carolina , Barboza‐Solís Cristina
Published: January 2020

Socioeconomic inequalities in cancer mortality have been described for a range of cancers sites worldwide, using diverse measures of socioeconomic position (SEP). These studies have shown a negative social gradient where lower SEP was associated with greater odds of having cancer, particularly in men. However, there is a lack of information regarding low and middle‐income countries. The objective of our study was to analyze the relationship between the socioeconomic characteristics of patients' residential districts and mortality due to cancer in Costa Rica between 2011 and 2017. An ecological study at the level of the district of residence was conducted using the multilevel mixed‐effects Poisson regression. All cancer‐caused deaths between January 1, 2011 and December 31, 2017 were included (n = 32,117). Eleven cancer sites were analyzed independently. The 477 Costa Rican districts were divided by area (urban/mixed/rural) and wealth using census data. All‐cancer combined a significant association between cancer mortality and wealth was found. Cancer mortality was lower in the poorest as compared to the richest districts (IRRQ4 = 0.79 [0.73–0.86]). The majority of cancer sites followed a similar pattern, showing a positive social gradient. These results contradict the international literature mostly conducted in high‐income countries. These findings confirmed the importance of conducting studies in middle‐income countries, since the socioeconomic and cultural contexts are different from those in high‐income countries, which influence the social distribution of lifestyles and risk behaviors.
Performance assessment of ensemble learning systems in financial data classification
Authors: Lahmiri Salim , Bekiros Stelios , Giakoumelou Anastasia , Bezzina Frank
Published: January 2020

Financial data classification plays an important role in investment and banking industry with the purpose to control default risk, improve cash and select the best customers. Ensemble learning and classification systems are becoming gradually more applied to classify financial data where outputs from different classification systems are combined. The objective of this research is to assess the relative performance of existing state‐of‐the‐art ensemble learning and classification systems with applications to corporate bankruptcy prediction and credit scoring. The considered ensemble systems include AdaBoost, LogitBoost, RUSBoost, subspace, and bagging ensemble system. The experimental results from three datasets: one is composed of quantitative attributes, one encompasses qualitative data, and another one combines both quantitative and qualitative attributes. By using ten‐fold cross‐validation method, the experimental results show that AdaBoost is effective in terms of low classification error, limited complexity, and short time processing of the data. In addition, the experimental results show that ensemble classification systems outperform existing models that were recently validated on the same databases. Therefore, ensemble classification system can be employed to increase the reliability and consistency of financial data classification task.
Optical coherence tomography image denoising using a generative adversarial network with speckle modulation
Authors: Dong Zhao , Liu Guoyan , Ni Guangming , Jerwick Jason , Duan Lian , Zhou Chao
Published: January 2020

Optical coherence tomography (OCT) is widely used for biomedical imaging and clinical diagnosis. However, speckle noise is a key factor affecting OCT image quality. Here, we developed a custom generative adversarial network (GAN) to denoise OCT images. A speckle‐modulating OCT (SM‐OCT) was built to generate low speckle images to be used as the ground truth. In total, 210 000 SM‐OCT images were used for training and validating the neural network model, which we call SM‐GAN. The performance of the SM‐GAN method was further demonstrated using online benchmark retinal images, 3D OCT images acquired from human fingers and OCT videos of a beating fruit fly heart. The denoise performance of the SM‐GAN model was compared to traditional OCT denoising methods and other state‐of‐the‐art deep learning based denoise networks. We conclude that the SM‐GAN model presented here can effectively reduce speckle noise in OCT images and videos while maintaining spatial and temporal resolutions.
Bone Mineral Density, Body Composition, and Mineral Homeostasis Over 24 Months in Urban South African Women With HIV Exposed to Antiretroviral Therapy
Authors: Hamill Matthew M , Pettifor John M , Ward Kate A , Norris Shane A , Prentice Ann
Published: January 2020

Human immunodeficiency virus‐ (HIV‐) infection and antiretroviral therapy (ART) exposure are associated with bone loss. African data are limited despite the region's HIV burden. Of 247 ART‐naïve, premenopausal, urban, black African women aged 33.9 ± 6.6 years from Soweto, South Africa, measured at baseline, 110 underwent anthropometry, DXA, and blood and urine collections at 12 and 24 months; 39 were HIV‐negative (Nref), 28 were people with HIV (PWH) not ART‐exposed for the duration of the study (ART‐N), and 43 were PWH who were ART‐exposed within the first 12 months (ART‐Y). At baseline, the ART‐Y group had lower BMI and fat mass than the Nref group. Within 12 months of ART initiation, areal bone mineral density (aBMD) had decreased at the lumbar spine and at the whole body less head, despite increased weight, and hip aBMD had not increased in line with the Nref group. There was no evidence of further bone changes between 12 and 24 months. By 24 months, the ART‐Y women had gained weight and fat mass, but remained lighter with less fat than the Nref women. ART initiation normalized the low serum albumin of the ART‐Y group at baseline, but was associated with elevated bone turnover markers at 12 and 24 months. Vitamin D status and renal phosphate handling were normal. ART‐N had similar aBMD and other characteristics to the Nref group throughout, except unlike the Nref group, weight and fat mass did not increase and serum albumin decreased. This study in African women of childbearing age demonstrated that the bone loss that had occurred in these PWH after ART initiation did not continue after 12 months and that bone loss did not occur in ART‐unexposed PWH over 2 years. At 24 months, despite gains in weight and fat mass, ART‐exposed women remained lighter, with lower aBMD, fat mass, and higher bone turnover than women without HIV. More studies are required to establish if the bone loss and fat gain reverse, stabilize, or continue with further ART exposure, particularly during and after menopause. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Community and well‐being: A qualitative study of how youth experiencing homelessness define community and its relations to their well‐being
Authors: Stewart Katricia , Townley Greg
Published: January 2020

Prior research with youth experiencing homelessness suggests that community experiences can play an important role in their resilience and well‐being. This literature suggests that a sense of community (SOC) and social support may be two key interpersonal factors related to the well‐being of this population. However, quantitative research exploring these relationships has resulted in inconsistent findings, which may be due to a lack of understanding regarding youth's definitions of and experiences with community. This study utilized semistructured qualitative interviews with 24 youth experiencing homelessness to explore their definitions of community, how it is important to them, what communities they are a part of, and how these communities contribute to their well‐being. Overall, findings suggest that (a) youth generally define community in ways that align with current theory on SOC, (b) youth view community as important, and (c) their experiences within community settings promote their overall well‐being in various ways. However, the findings also suggest that community is not always a positive experience for these youth. This study has implications for how to promote the well‐being of youth experiencing homelessness, as well as how SOC and social support may relate to the well‐being of this population.
IFN‐γ/mTORC1 decreased Rab11 in Schwann cells of diabetic peripheral neuropathy, inhibiting cell proliferation via GLUT1 downregulation
Authors: Du Wei , Zhao Song , Gao Fan , Wei Mengyu , An Jiahui , Jia Keqi , Li Fan , Zhu Lin , Hao Jun
Published: January 2020

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes mellitus. Rab11 is conserved gene‐regulating vesicle traffic and reported to be involved in the pathogenesis of diabetes mellitus by affecting insulin sensitivity. We aimed to investigate the role of Rab11 in the pathogenesis of DPN. In this study, Rab11 expression decreased in the sciatic nerves of diabetic mice with impaired conduction function versus those of normal mice. In vitro experiment revealed interferon‐γ (IFN‐γ), not high glucose and interleukin 1β was the main factor to lead to Rab11 downregulation in RSC96 cells. Again, both Rab11 knockdown and IFN‐γ treatment caused cell viability inhibition and the decrease in BrdU‐positive cells. In contrast, overexpression of Rab11 reversed IFN‐γ‐reduced cell proliferation. Furthermore, mTORC1 not mTORC2 was proven to be suppressed by IFN‐γ treatment in RSC96 cells, indicated in decreased phospho‐p70S6K. Inhibition of the mTORC1 pathway resulted in Rab11 expression downregulation in RSC96 cells. Activation of the mTORC1 pathway effectively prevented IFN‐γ‐reduced Rab11 expression in RSC96 cells. Also, glucose transporter 1 (GLUT1) was found to be downregulated in RSC96 cells with Rab11 silence and overexpression of GLUT1 reversed Rab11 blocking‐caused proliferation inhibition. Taken together, our findings suggest that IFN‐γ decreases Rab11 expression via the inhibition of the mTORC1 signaling pathway, causing reduced cell proliferation in Schwann cells of DPN by GLUT1 downregulation.