bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction between Silver Nanoparticles and Two Dehydrogenases: Role of Thiol Groups
Authors: Jiang Hong Sheng , Zhang Yizhi , Lu Zhen Wei , Lebrun Régine , Gontero Brigitte , Li Wei
Published: May 2019

Widely used silver nanoparticles (AgNPs) are readily accessible to biological fluids and then surrounded by proteins. However, interactions between AgNPs and proteins are poorly understood. Two dehydrogenases, glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and malate dehydrogenase (MDH), are chosen to investigate these interactions. Ag bound to thiol groups of these enzymes significantly decreases the number of free thiols available. Dose‐dependent inhibition of enzyme activities is observed in both AgNPs and Ag+ treatments. Based on the concentration required to inhibit 50% activity, GAPDH and MDH are 24–30 fold more sensitive to Ag+ than to AgNPs suggesting that the measured 4.2% Ag+ containing AgNPs can be responsible for the enzymes inhibition. GAPDH, with a thiol group in its active site, is more sensitive to Ag than MDH, displaying many thiol groups but none in its active site, suggesting that thiol groups at the active site strongly determines the sensitivity of enzymes toward AgNPs. In contrast, the dramatic changes of circular dichroism spectra show that the global secondary structure of MDH under AgNPs treatment is more altered than that of GAPDH. In summary, this study shows that the thiol groups and their location on these dehydrogenases are crucial for the AgNPs effects.
Controlled Electrodeposition of Gold on Graphene: Maximization of the Defect‐Enhanced Raman Scattering Response
Authors: Ananthoju Balakrishna , Biroju Ravi K. , Theis Wolfgang , Dryfe Robert A. W.
Published: May 2019

A reliable method to prepare a surface‐enhanced Raman scattering (SERS) active substrate is developed herein, by electrodeposition of gold nanoparticles (Au NPs) on defect‐engineered, large area chemical vapour deposition graphene (GR). A plasma treatment strategy is used in order to engineer the structural defects on the basal plane of large area single‐layer graphene. This defect‐engineered Au functionalized GR, offers reproducible SERS signals over the large area GR surface. The Raman data, along with X‐ray photoelectron spectroscopy and analysis of the water contact angle are used to rationalize the functionalization of the graphene layer. It is found that Au NPs functionalization of the “defect‐engineered” graphene substrates permits detection of concentrations as low as 10−16 m for the probe molecule Rhodamine B, which offers an outstanding molecular sensing ability. Interestingly, a Raman signal enhancement of up to ≈108 is achieved. Moreover, it is observed that GR effectively quenches the fluorescence background from the Au NPs and molecules due to the strong resonance energy transfer between Au NPs and GR. The results presented offer significant direction for the design and fabrication of ultra‐sensitive SERS platforms, and also open up possibilities for novel applications of defect engineered graphene in biosensors, catalysis, and optoelectronic devices.
A Detailed Structural Analysis of CdxNb6(O,F)16
Authors: Krumeich Frank , Wörle Michael
Published: May 2019

The structure of CdxNb6(O,F)16 was re‐determined from X‐ray single crystal diffraction data. It crystallizes in the orthorhombic LiNb6O15F structure type in the space group Pmma. Remarkably, there is a shift of the Nb positions along the short b axis out of the mirror plane and a partial and disordered occupancy of square channels by Cd. The composition was refined to Cd0.274(6)Nb6O14.55F1.45. Light microscopy and scanning electron microscopy (SEM) images show the frequent intergrowth of crystallites on the micrometer scale whereas high‐resolution transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) images reveal a perfectly ordered structure in most areas investigated. A single grain boundary was uncovered with the structures in the adjacent domains tilted by 4° in respect of each other. In parts of the interface, the adjacent domains are coherently connected in a way not observed before. Additional defects are present at irregular intervals that apparently compensate resulting strain.
Synthesis of Nitro‐Octaaza Derivatives of Reduced Anthracene
Authors: Il'yasov Sergey G. , Glukhacheva Vera S. , Yermoshina Valentina A. , Eltsov Ilia V.
Published: May 2019

Nitro compounds of octaaza derivatives of reduced anthracene were synthesized for the first time by reaction of 2,3,4a,6,7,8a,9,10‐octaaza‐4,8‐dioxo‐3,4,4a,7,8,8a,9,9a,10,10a‐decahydroanthracene with nitric acid, mixed nitric acid/sulfuric acid, and nitric acid/acetic anhydride at between –20 and –30 °C. In addition, 1,2,4,5‐tetrazine azido derivatives were obtained by hydrolytic decomposition of the starting compound by nitrous acid. All the resultant compounds exhibit high thermal stability.
3d Abelian gauge theories at the boundary
Authors: Di Pietro Lorenzo , Gaiotto Davide , Lauria Edoardo , Wu Jingxiang
Published: May 2019

Abstract

A four-dimensional Abelian gauge field can be coupled to a 3d CFT with a U(1) symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFT) parametrized by the gauge coupling τ in the upper-half plane and by the choice of the CFT in the decoupling limit τ → ∞. Upon performing an SL(2, ℤ) transformation in the bulk and going to the decoupling limit in the new frame, one finds a different 3d CFT on the boundary, related to the original one by Witten’s SL(2, ℤ) action [1]. In particular the cusps on the real τ axis correspond to the 3d gauging of the original CFT. We study general properties of this BCFT. We show how to express bulk one and two-point functions, and the hemisphere free-energy, in terms of the two-point functions of the boundary electric and magnetic currents. We then consider the case in which the 3d CFT is one Dirac fermion. Thanks to 3d dualities this BCFT is mapped to itself by a bulk S transformation, and it also admits a decoupling limit which gives the O(2) model on the boundary. We compute scaling dimensions of boundary operators and the hemisphere free-energy up to two loops. Using an S-duality improved ansatz, we extrapolate the perturbative results and find good approximations to the observables of the O(2) model. We also consider examples with other theories on the boundary, such as large-N

f
Dirac fermions — for which the extrapolation to strong coupling can be done exactly order-by-order in 1/N

f
— and a free complex scalar.
Colorful imprints of heavy states in the electroweak effective theory
Authors: Krause Claudius , Pich Antonio , Rosell Ignasi , Santos Joaquín , Sanz-Cillero Juan José
Published: May 2019

Abstract

We analyze heavy states from generic ultraviolet completions of the Standard Model in a model-independent way and investigate their implications on the low-energy couplings of the electroweak effective theory. We build a general effective Lagrangian, implementing the electroweak symmetry breaking SU(2)
L
⊗ SU(2)
R
→ SU(2)
L+R
with a non-linear Nambu-Goldstone realization, which couples the known particles to the heavy states. We generalize the formalism developed in previous works [1, 2] to include colored resonances, both of bosonic and fermionic type. We study bosonic heavy states with J

P
= 0± and J

P
= 1±, in singlet or triplet SU(2)
L+R
representations and in singlet or octet representations of SU(3)
C
, and fermionic resonances with

$$ J=\frac{1}{2} $$

J
=

1
2

that are electroweak doublets and QCD triplets or singlets. Integrating out the heavy scales, we determine the complete pattern of low-energy couplings at the lowest non-trivial order. Some specific types of (strongly- and weakly-coupled) ultraviolet completions are discussed to illustrate the generality of our approach and to make contact with current experimental searches.
Emerging Evidence that ApoC-III Inhibitors Provide Novel Options to Reduce the Residual CVD
Authors: Taskinen Marja-Riitta , Packard Chris J. , Borén Jan
Published: May 2019

Purpose of Review

Apolipoprotein C-III (apoC-III) is known to inhibit lipoprotein lipase (LPL) and function as an important regulator of triglyceride metabolism. In addition, apoC-III has also more recently been identified as an important risk factor for cardiovascular disease. This review summarizes the mechanisms by which apoC-III induces hypertriglyceridemia and promotes atherogenesis, as well as the findings from recent clinical trials using novel strategies for lowering apoC-III.

Recent Findings

Genetic studies have identified subjects with heterozygote loss-of-function (LOF) mutations in APOC3, the gene coding for apoC-III. Clinical characterization of these individuals shows that the LOF variants associate with a low-risk lipoprotein profile, in particular reduced plasma triglycerides. Recent results also show that complete deficiency of apoC-III is not a lethal mutation and is associated with very rapid lipolysis of plasma triglyceride-rich lipoproteins (TRL). Ongoing trials based on emerging gene-silencing technologies show that intervention markedly lowers apoC-III levels and, consequently, plasma triglyceride. Unexpectedly, the evidence points to apoC-III not only inhibiting LPL activity but also suppressing removal of TRLs by LPL-independent pathways.

Available data clearly show that apoC-III is an important cardiovascular risk factor and that lifelong deficiency of apoC-III is cardioprotective. Novel therapies have been developed, and results from recent clinical trials indicate that effective reduction of plasma triglycerides by inhibition of apoC-III might be a promising strategy in management of severe hypertriglyceridemia and, more generally, a novel approach to CHD prevention in those with elevated plasma triglyceride.
Shear Wave Velocity Characteristics in Parts of Muscat, Sultanate of Oman — A Measure of Earthquake Hazard Assessment
Authors: Sundararajan N. , El-Hussain Issa , Mohamed Adel M. E. , Deif Ahmed , El-Hady Sheref , El-Jabri Khalifa , Al-Rawas Ghazi , Zain Yahia El , Kwarteng Andy , Al-Wardi Mohammed
Published: May 2019

Shear-wave velocity-depth information plays a significant role in assessing earthquake hazard of any region. Further, it is required for most investigations of ground motion response to earthquakes in areas where significant soil cover exists. The thickness and velocity of geologic formations are the vital parameters above the bedrock that affect the frequency band of the ground motion that may be strongly amplified by the local site conditions. In view of this, shear-wave velocity assumes great importance in earthquake hazard assessment studies. The characteristics of shear-wave velocity profile were determined by multichannel analysis of surface waves (MASW) technique in as many as 99 sites over different geological units in parts of Muscat city in order to evaluate probable hazard if any. The variations of shear wave velocity down to depths of 5 m, 10 m, 15 m and 30 m, respectively are presented. However, the average shear wave velocities calculated down to a depth of 30 m (VS30) vary between 345 m/s and 1197 m/s. The high range of shear-wave velocity almost rules out the liquefaction potential due to earthquakes of moderate to high magnitude.
Variations in Stable Isotopes of Oxygen and Hydrogen in Surface and Groundwater of a Managed Aquifer Recharge Site: A Case Study
Authors: Parimalarenganayaki S. , Elango L. , Schneider Michael
Published: May 2019

Groundwater storage augmented by Managed Aquifer Recharge methods in a region will help to manage water supply when there is insufficient availability surface water. The present study was carried out to use the stable isotopes of oxygen and hydrogen to study the interaction between the surface and groundwater at Managed Aquifer Recharge (Check dam) site located north of Chennai, Tamil Nadu, India. Water samples from check dam were collected at periodical intervals from October 2011 to April 2012 and groundwater samples from the wells surrounding the dam were collected for the period between January 2012 and July 2012. Electrical conductivity of the water samples was measured using multi parameter probe (YSI 556). Chloride is analysed by standard titration method. δD and δ18O were analysed by PICARRO L1102-i isotope analyser. The variation in isotopic signatures of water from the check dam indicated that water stored in the check dam undergone various degrees of evaporation. The relationship of δ18O with electrical conductivity and chloride of groundwater and water from check dam assisted in delineating the wells recharged from check dam. It is identified, that the wells located 1.5 km surrounding the check dam is benefitted by this structure.
Assessment of Groundwater Pollution Vulnerability Using GIS-Based DRASTIC Model and its Validation Using Nitrate Concentration in Tandula Watershed, Chhattisgarh
Authors: Jhariya D. C.
Published: May 2019

Effective management of groundwater resources has now become a global issue and on the other hand industrialization, deforestation and agricultural activities are potential sources of groundwater pollution. Groundwater vulnerability index assessment is an effective tool for groundwater management. In this study DRASTIC model was utilized to evaluate aquifer vulnerability of Tandula watershed, Chhattisgarh, India. Aquifer vulnerability of the study area classified into five categories such as very low (18.68%), low (23.84%), moderate (16.42%), high (23.72%) and very high (17.34%) vulnerability. To validate the DRASTIC model, nitrate concentration was selected and found that it is 82.35% accurate which reflects that, DRASTIC model is appropriate to understand groundwater pollution risk assessment. In the study area groundwater is contaminated mainly due to extensive use of fertilizer for agriculture purpose. Present study will be helpful in proper management and development of available groundwater resource in the study area.
Assessment of Indoor Radon and Thoron in Dwellings of Nangal Area Using SSNTD
Authors: Kaur Rupinderjeet , Shikha Deep , Singh Supreet Pal , Mehta Vimal
Published: May 2019

Radon effect on human health need not be overemphasised. In the present study an attempt has been made to measure the concentration of indoor radon, thoron and annual effective dose received by residents of Nangal area of Roopnagar District of Punjab. Radium concentration and Radon exhalation in soil samples are also calculated. Indoor radon concentration varies from 93.1 Bqm-3 to 127.0 Bqm-3 with an average of 95.4 Bqm-3. The value of thoron concentration varies from 5.4 Bqm-3 to 47.2 Bqm-3 with an average of 24.0 Bqm-3. The observed annual effective dose varies from 2.3 mSv to 3.7 mSv which lies within safe limits recommended by ICRP (International Commission on Radiological Protection). Radon gas concentration in soil samples vary from 8.4 to 64.1 Bqm-3 with an average of 31.4 Bqm-3. The mass exhalation rate in samples vary from 0.2 to 2.7 mBq kg-1 h-1 with an average of 1.1 mBq kg-1 h-1, whereas, surface exhalation rate vary from 6.9 to 52.5 mBq m-2 h-1 with an average of 23.6 mBq m-2 h-1. The radium concentration ranges from 0.5 to 3.5 Bq kg-1 with an average of 1.8 Bq kg-1. The observed values of radium concentration in all soil samples are less than the recommended value 370 Bq kg-1 by OECD (Organization for Economic Corporation and Development).
Can biometrics secure the Internet of Things?
Authors: Orme David
Published: May 2019

One of today's biggest security challenges is how to safeguard the wide range of emerging Internet of Things devices – everything from autonomous vehicles to smart homes and fridges. In this interview, IoT specialist David Orme from IDEX Biometrics explains why he believes biometrics can play a significant role in solving this problem.
Gamification as a winning cyber security strategy
Authors: Wolfenden Brad
Published: May 2019

We are more connected than ever before. Our smart TVs and refrigerators, phones and drones, online bank accounts and electronic health records, and so much more, are on the web and in the cloud – connected and ‘talking’ to each other. While creating convenience for the end user, this growing interconnected digital footprint creates a ripe surface for a cyber criminal to attack.

Just like in some video games, consumers and business leaders find themselves battling the consequences of interconnectivity and are trying to keep opponents from exploiting their information and damaging their reputation.

In this “game of protection’ to balance defensive and offensive security techniques, now is the time for CISOs and business leaders to reach for a new cyber security manual – one that leverages gamification. This is the process of exploiting game-like elements to improve information retention and the application of skills, explains Brad Wolfenden of Circadence.
COMPATIBILITY AND ATTAINABILITY OF MATRICES OF CORRELATION-BASED MEASURES OF CONCORDANCE
Authors: Hofert Marius , Koike Takaaki
Published: May 2019

Measures of concordance have been widely used in insurance and risk management to summarize nonlinear dependence among risks modeled by random variables, which Pearson’s correlation coefficient cannot capture. However, popular measures of concordance, such as Spearman’s rho and Blomqvist’s beta, appear as classical correlations of transformed random variables. We characterize a whole class of such concordance measures arising from correlations of transformed random variables, which includes Spearman’s rho, Blomqvist’s beta and van der Waerden’s coefficient as special cases. Compatibility and attainability of square matrices with entries given by such measures are studied—that is, whether a given square matrix of such measures of concordance can be realized for some random vector and how such a random vector can be constructed. Compatibility and attainability of block matrices and hierarchical matrices are also studied due to their practical importance in insurance and risk management. In particular, a subclass of attainable block Spearman’s rho matrices is proposed to compensate for the drawback that Spearman’s rho matrices are in general not attainable for dimensions larger than three. Another result concerns a novel analytical form of the Cholesky factor of block matrices which allows one, for example, to construct random vectors with given block matrices of van der Waerden’s coefficient.
Parental Involvement in Supporting Their Children with Special Educational Needs at School and Home in Bhutan
Authors: Jigyel Karma , Miller Judith A. , Mavropoulou Sofia , Berman Jeanette
Published: May 2019

This paper reports the findings from a study investigating Bhutanese parents’ involvement in supporting their children with special educational needs (SEN) in schooling. The interaction between the parents themselves in supporting each other was also explored. Individual interviews were conducted with 26 parents (13 fathers and 13 mothers) of children with either full inclusion or partial inclusion in 3 schools located in 3 regions (urban, semi-urban, and rural) and analysed using manual thematic coding and Leximancer text mining software. Of Epstein’s (1987) 6 types of parental involvement activities in education, these parents reported their actions to be parenting, volunteering in schools, supporting learning and development at home, and collaborating with the community. The minimal interaction among the parents was mostly between the stay-in-school urban mothers who had consistent but impromptu and informal interactions. The implications of this study inform the need for schools to respond to policy and to actively engage parents, and for education programs and support groups to be set up to strengthen parental involvement in the education of children with SEN in Bhutan.
Understanding the Southern Italian commons: polycentric governance on the mountains of Sila
Authors: de Majo Claudio
Published: May 2019

In this article, I examine patterns of collective action in the South of Italy, a region where commons scholarship presents several challenges, mainly due to its feudal heritage. In analysing the history of Southern Italian commons, Elinor Ostrom's theories on polycentric governance are adopted. I propose a case study on the mountains of Sila, where collective action was institutionalised through a municipal organisation known as universitas casalium, consisting of the city of Cosenza and its hamlets. This institution collaborated with the royal government, creating a polycentric governance system where institutional functions contentiously intermingled, generating conflicting relations, but also unique governmental arrangements. Yet how did previous historical interpretations miss this point? Documentary evidence provides a clear answer: while the institutional recognition of the universitas casalium can be traced back as far as the twelfth century, a series of institutional reforms initiated in the mid-fifteenth century led to the progressive decline of the local institution and accordingly of the commons economy related to it. This loss of legitimacy derived from the emergence of feudal barons and later of landowners from the middle class, leading to the progressive dissolution of collective action in Sila as Italy moved towards Italian unification in 1861.
Variation of 14C in Japanese Tree Rings Related to the Fukushima Nuclear Accident
Authors: Varga Tamás , Palcsu László , Ohta Tomoko , Mahara Yasunori , Jull A J Timothy , Molnár Mihály
Published: May 2019

Radiocarbon (14C) analysis was performed on Japanese cedar (Cryptomeria japonica) tree rings from Koriyama, Fukushima prefecture. Our primary aim was to detect any 14C release from the Fukushima Dai-ichi nuclear power plant accident on 11 March 2011. We also completed and assessed the 14C level in Japanese tree rings for the period of 1990–2014 because of the lack of environmental 14C results in the Japanese island that time. For this reason, we used a trajectory model to investigate the air mass forward and backward trajectories at the area of the power plant and sampling site. The modeling data show that the air masses mainly moved to the Pacific Ocean, both during March 2011 and during the growing season (March–September). During the period 1990–2014 there was no significant 14C excess in any of the samples, but there was a detectable Suess effect in almost every tree ring sample. The average fossil contribution was 0.83 ± 0.01% and the calculated anthropogenic component ratio, the 14C excess varied between +0.5 and –1.6%. The Δ14C value decreased from 150.0‰ to 9.5‰ from 1990–2014, which follows the decline of the 14C bomb peak, in addition to any detectable Suess effect.
The U.S. Embassy Move to Jerusalem: Mixed Messages and Mixed Blessings for Israel?
Authors: Dumper Mick
Published: May 2019

The U.S. decision in December 2017 to move its embassy in Israel from Tel Aviv to Jerusalem recognizes the latter as the capital of Israel. While violating several UN resolutions and international law, it has in the short-term impacted the negotiations between the Palestinian Liberation Organization (PLO) and Israel. In the longer term we can see that the impact of the decision is also more complex and nuanced. There are three main areas which suggest this to be the case: First, the lack of clarity over the decision itself; second, the varying degrees of sovereignty exercised by Israel in different parts of Jerusalem due to the city's long and religiously diverse history; and thirdly, the contradictions inherent in imposing a nationalist ideology upon a cosmopolitan and heterodox city.
Evolution, Biogeography, and Systematics ofPuriana: Evolution and Speciation in Ostracoda, III
Authors: Cronin Thomas M.
Published: May 2019

Three types of geographic isolation—land barriers, deep water barriers, and climatic barriers—resulted in three distinct evolutionary responses in Neogene and Quaternary species of the epineritic ostracode genusPuriana. Through systematic, paleobiogeographic, and morphologic study of several hundred fossil and Recent populations from the eastern Pacific, western Atlantic, Gulf of Mexico, and the Caribbean, the phylogeny of the genus and the geography of speciation events were determined. Isolation of large populations by the Isthmus of Panama during the Pliocene did not lead to lineage splitting in species known to have existed before the Isthmus formed. Conversely, the establishment of small isolated populations on Caribbean islands by passive dispersal mechanisms frequently led to the evolution of new species or subspecies. Climatic changes along the southeastern United States during the Pliocene also catalyzed possible parapatric speciation as populations that immigrated to the northeastern periphery of the genus' range split to form new species. The results provide evidence that evolutionary models describing the influence of abiotic events on patterns of evolution and speciation can be tested using properly selected tectonic and climatic events and fossil groups amenable to species-level analysis. Two new species,P. bajaensisandP. paikensis, are described.
Linear gyrokinetic studies with ORB5 en route to pair plasmas
Authors: Horn-Stanja J. , Biancalani A. , Bottino A. , Mishchenko A.
Published: May 2019

The model of the global gyrokinetic particle-in-cell code ORB5 has been extended for the study of pair plasmas. This has been done by including the physics of the Debye shielding, by including the electron polarization density and by retaining the effects of the electron finite Larmor radius. This model is verified against previous numerical results for the cyclone base case tokamak scenario in deuterium plasmas, and for local pair plasma simulations. The linear dynamics of temperature-gradient driven instabilities and geodesic acoustic modes is investigated. Mass dependencies for different Debye lengths are studied.
Manly Civilization in China: Harry R. Caldwell, the ‘Blue Tiger’, and the American Museum of Natural History
Authors: CHAN YING-KIT
Published: May 2019

This article examines the transplantation of America's ‘manly’ civilization to 1920s Fujian, China, through the experiences of Harry R. Caldwell (1876–1970), a Methodist missionary whose hunting was central to his social evangelism. With his rifle, Caldwell protected Chinese villagers from man-eating tigers, taught them how to hunt tigers effectively, and enabled them to reconceptualize their relationships with tigers and nature. By engaging the American Museum of Natural History in his specimen collection and hunt for the mythical ‘Blue Tiger’, Caldwell introduced an economy of natural expeditions to the villagers who were hired to support the hunt. This article argues that Caldwell's experiences as both a missionary and a hunter in Fujian was an extension, or negotiation, of his rugged masculinity, which was fostered in his Tennessee home town. He identified as both a Christian and a hunter, and he did not see these parts of himself as distinct. A comparison between Caldwell and his contemporary, the British naturalist Arthur de Carle Sowerby (1885–1954), accentuates America's rugged masculinity by suggesting different national approaches to hunting and the growing professionalization of the naturalist.
Cellular Alterations Resulting from Foliar Applications of HOE-39866
Authors: Bellinder Robin R. , Lyons Robert E. , Scheckler Stephen E. , Wilson Henry P.
Published: May 2019

Formulated and technical grade HOE-39866 [ammonium-(3-amino-3-carboxypropyl) methylphosphinate] at concentrations of 10–1, 10–2, and 10–3M were applied to leaf blade tissues of nonreproductive adult redroot pigweed (Amaranthus retroflexusL. # AMARE) and fall panicum (Panicum dichotomiflorumMichx. # PANDI). Tissues were sampled at regular intervals after treatment and prepared for light microscopic examination. The major response of both species involved rupture and contortion of the interveinal mesophyll cells with concomitant disorganization of the bundle sheath cells. Rapid epidermal collapse occurred in redroot pigweed but not in fall panicum. The absence of adjuvants resulted in nonuniform symptom expression as herbicide droplets accumulated in depressions and along leaf margins. No other adjuvant-specific effect was observed. Herbicide concentration did not alter the final response but the time-to-expression increased as concentration decreased.
Effects of Nonionic Surfactants, Temperature, and Light on Germination of Weed Seeds
Authors: Hurtt Woodland , Hodgson Richard H.
Published: May 2019

The nonionic surfactants Tween 20 [oxysorbic (20 POE) polyoxyethylene sorbitan monolaurate] and Tween 80 [oxysorbic (20 POE) polyoxyethylene sorbitan monooleate] at concentrations of 0.05, 0.1, 0.2, and 0.4% v/v stimulated germination of barnyardgrass [Echinochloa crus-galli(L.) Beauv. # ECHCG] seeds in petri dishes. Stimulation occurred under both 30/20 and 25/15 C diurnal temperature cycles whether or not light was supplied during the 8-h high-temperature portion of the cycle. Barnyardgrass responded most to treatment under environmental conditions in which untreated seeds germinated the least. A 0.1% surfactant concentration often stimulated germination of weed seeds as effectively as did higher concentrations. Germination of redroot pigweed [Amaranthus retroflexusL. # AMARE] seeds was inhibited by Tween 80 in the light under both the low- and high-temperature regimes and by Tween 20 at low temperature in the light. Germination of tumble pigweed (Amaranthus albusL. # AMAAL) seeds was inhibited by both surfactants in the high-temperature regime whether or not light was supplied. Common purslane (Portulaca oleraceaL. # POROL) seeds were insensitive to treatment.
Interference of Hemp Sesbania (Sesbania exaltata) with Cotton (Gossypium hirsutum)
Authors: Bryson Charles T.
Published: May 2019

Full-season interference effects of hemp sesbania [Sesbania exaltata(Raf.) Cory. # SEBEX] on cotton (Gossypium hirsutumL. 'Stoneville 213′) were investigated on a fine sandy loam soil for 3 yr at Stoneville, MS. Experimentally induced hemp sesbania populations of ≥ 3223 plants/ha significantly reduced cotton yields. Interference of hemp sesbania at 3223, 6456, 16 114, and 32 228 plants/ha, equivalent to 1, 2, 5, and 10 plants/3.3 m, reduced seed cotton yields by 19, 25, 45, and 53%, respectively. Cotton boll weights were reduced by 9% when hemp sesbania infestations were ≥ 16 114 plants/ha. Cotton plant density, seedling vigor, and initial cotton white blooms/ha at ≤75 days after planting (DAP) did not differ with varying densities of hemp sesbania. Cotton white blooms/ha were reduced by 32 228 hemp sesbania plants/ha by 77 DAP and by all weed densities by 98 DAP. Hemp sesbania height was equal to or greater than cotton height by 55 to 65 DAP. Light penetration at 1 m above the top of the cotton canopy was 36% less than in weed-free plots when hemp sesbania densities were ≤6446 plants/ha. Likewise, light penetration was reduced at the cotton canopy top and at midcanopy but was not less at the soil surface unless hemp sesbania densities were ≤ 32 223 plants/ha.
Effect of Chlorsulfuron on Diclofop Phytotoxicity to Italian Ryegrass (Lolium multiflorum)
Authors: Liebl Rex , Worsham A. Douglas
Published: May 2019

The effect of chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5 -triazin-2-yl)amino] carbonyl] benzenesulfonamide} on the phytotoxicity of postemergence applications of the methyl ester of diclofop ((±)-2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} to Italian ryegrass [Lolium multiflorum(Lam.) # LOLMU] was investigated in field and greenhouse experiments. The addition of chlorsulfuron (14.8 g ai/ha field, 12.4 g/ha greenhouse) to 0.90 kg/ha diclofop reduced Italian ryegrass control 27% in the field and increased Italian ryegrass fresh weights in the greenhouse more than twofold over diclofop alone. The antagonism was more evident when combinations were used to treat Italian ryegrass in the three-leaf stage than the two- or four-leaf stage. Sequential applications yielded results similar to tank mix combinations. Chlorsulfuron and diclofop were approximately 400 and 50%, respectively, more active on Italian ryegrass when applied preemergence than when applied postemergence. Combinations of chlorsulfuron and diclofop applied preemergence to Italian ryegrass resulted in additive responses.
Annual Grass Control in Cotton (Gossypium hirsutum) with Fluazifop, Sethoxydim, and Selected Dinitroaniline Herbicides
Authors: Byrd John D. , York Alan C.
Published: May 2019

One and two postemergence (POE) applications of the butyl ester of fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy]phenoxy] propanoic acid} or sethoxydim (2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} following preemergence (PRE) application of fluometuron {N,N-dimethyl-N′-[3-(trifluoromethyl)phenyl] urea} were compared to a preplant-incorporated (PPI) application of trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] or pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] plus fluometuron PRE or pendimethalin plus fluometuron PRE for annual grass control in cotton (Gossypium hirsutumL.) and net economic return to land, overhead, and management. One POE application of either fluazifop or sethoxydim following fluometuron PRE resulted in greater control of a high population of broadleaf signalgrass [Brachiaria platyphylla(Griseb.) Nash. # BRAPP] and greater yield and net return than a PPI application of trifluralin or pendimethalin plus fluometuron PRE. A second application of fluazifop or sethoxydim increased late-season control but did not increase yield or net return. In a high population of large crabgrass (Digitaria sanguinalisL. # DIGSA), fluometuron PRE plus two POE applications of fluazifop or sethoxydim resulted in grass control, lint yield, and net return similar to trifluralin or pendimethalin PPI plus fluometuron PRE. No differences in grass control, crop response, or net return were noted between PPI application of trifluralin or pendimethalin. Control of broadleaf signalgrass and large crabgrass with pendimethalin plus fluometuron PRE was less than with pendimethalin PPI plus fluometuron PRE. In fields with a low population of large crabgrass, fall panicum (Panicum dichotomiflorumMichx. # PANDI), and goosegrass [Eleusine indica(L.) Gaertn. # ELEIN], fluometuron PRE provided excellent season-long control. No benefits were obtained from addition of a grass herbicide. No treatments affected cotton maturity or fiber quality.
Effects of Adjuvants on Behavior of Metribuzin in Soil and Soybean Injury
Authors: Street Joe E. , Wehtje Glenn , Walker Robert H. , Patterson Michael G.
Published: May 2019

Three adjuvants, ARD 54, ARD 93, and ARD 1836, were evaluated for their ability to reduce metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] phytotoxicity to soybeans [Glycine max(L.) Merr.] in sandy soils. A reduction in metribuzin phytotoxicity was observed, usually without reductions in sicklepod (Cassia obtusifoliaL. # CASOB) control. The addition of linseed oil to a spray suspension containing 1% ARD 1836 reduced sicklepod control slightly at one of two locations. The addition of these adjuvants and linseed oil to the spray solution had no effect on soybean yield. These adjuvants slightly reduced movement of metribuzin in thin-layer soil chromatography but had no influence on sorption in batch-equilibrium experiments.
Effects ofSphacelotheca holciInfection on Morphology and Competitiveness of Johnsongrass (Sorghum halepense)
Authors: Massion Cheo L. , Lindow Steven E.
Published: May 2019

Teliospores ofSphacelotheca holciJack. [=S. cruenta(Kuhn.) Potter] infected johnsongrass [Sorghum halepense(L.) Pers. # SORHA) systemically after inoculation of cut stems in greenhouse studies. A preliminary host range test in the greenhouse revealed that no infection occurred on four varieties of sorghum (S. vulgareL.) and three cultivars of sudangrass (S. SudaneseL.). Infected johnsongrass plants grown in the greenhouse exhibited reduced vegetative growth and altered morphological characteristics compared to healthy johnsongrass plants. The aboveground biomass and lateral rhizome expansion of smutted johnsongrass field transplants were significantly lower than that of uninfected plants. Significant correlations between fraction of johnsongrass stems infected and plant weight, and basal area of plants were observed in field studies. Corn (Zea maysL.) and alfalfa (Medicago sativaL.) grown in competition with johnsongrass, and johnsongrass infected withS. holcireduced the aboveground biomass and rhizome length of johnsongrass plants significantly, compared to that of uninfected johnsongrass plants grown alone in greenhouse studies. Uninfected johnsongrass plants also exhibited higher plant weight than infected plants when both were grown in competition with alfalfa, regardless of the alfalfa planting density in the greenhouse or when measured after 3 months in field trials.
Total Alkaloid, Crude Protein, and Fiber Concentrations in Velvet Lupine (Lupinus leucophyllus) Following Herbicide Application
Authors: Ralphs Michael H. , Williams M. Coburn
Published: May 2019

Total alkaloid concentration, percentage water, crude protein, and neutral detergent fiber in velvet lupine (Lupinus leucophyllus Dougl. # LUPLE) were monitored for 3 weeks following application of herbicides registered or soon to be registered for rangeland use. Picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid), dicamba (3,6-dichloro-2-methoxybenzoic acid), and clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) caused some signs of epinasty but did not kill velvet lupine. Total alkaloid concentration and nutrient quality of velvet lupine leaves treated with these herbicides was not significantly different from untreated plants. Esters of 2,4-D [(2,4-dichlorophenoxy)acetic acid] and 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] and triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid} killed most velvet lupine plants and caused a subsequent decrease in total alkaloid concentration, crude protein, and water content as the plants desiccated. Herbicides that effectively killed velvet lupine decreased alkaloid levels, thus lowering the potential for increased livestock poisoning.
Correlative Inhibition and Dormancy in Root Buds of Leafy Spurge (Euphorbia esula)
Authors: Nissen Scott J. , Foley Michael E.
Published: May 2019

Root buds of leafy spurge (Euphorbia esulaL. # EPHES) were found to be quiescent during most of the growing season due to correlative inhibition rather than innate dormancy. Excised root buds taken from plants that were fully flowering showed reduced elongation, indicating a period of innate dormancy. This innate dormancy could be eliminated by chilling plants for 8 days at 4 C. Root buds from plants showing late summer regrowth were no longer innately dormant. IAA (indole-3-acetic acid) and NAA (1-napthaleneacetic acid) completely inhibited the growth of excised leafy spurge root buds at concentrations of 10−3and 10−5M, respectively. A significant increase in root bud elongation was produced by 1 mM TIBA (2,3,5-triiodobenzoic acid) applied to stem and root tissue. These data provide further evidence for the involvement of IAA in correlative control of root bud growth in leafy spurge.
Influence of Planting Date on Growth of Palmer Amaranth (Amaranthus palmeri)
Authors: Keeley Paul E. , Carter Charles H. , Thullen Robert J.
Published: May 2019

Palmer amaranth (Amaranthus palmeriS. Wats. # AMAPA) planted in a field at monthly intervals from March through October at Shafter, CA, began to emerge in March when soil temperatures at a depth of 5 cm reached 18 C. With the exception of March and April plantings, at least 50% of the seed of later plantings produced seedlings within 2 weeks after planting. Although growth of plants was initially slower for early plantings, plantings from March to July reached 2 m or greater in height by fall. Due to longer growing times, plantings from March to June eventually produced more dry matter and a greater number of inflorescences than later plantings. Plants began flowering 5 to 9 weeks after planting in March through June and 3 to 4 weeks after planting in July through October. Some viable seed was produced as early as 2 to 3 weeks after flowering began. Total seed production in the fall ranged from 200 000 to 600 000 seed/plant for the March through June plantings, and 115 to 80 000 seed/plant for the July through September plantings. Killing frosts in November prevented Palmer amaranth planted in October from producing seed.
Factors Affecting Postemergence Control of Sicklepod (Cassia obtusifolia) with Imazaquin and DPX-F6025: Spray Volume, Growth Stage, and Soil-Applied Alachlor and Vernolate
Authors: Edmund Richard M. , York Alan C.
Published: May 2019

In field and greenhouse experiments, sicklepod (Cassia obtusifoliaL. # CASOB) control with postemergence application of imazaquin {ammonium salt of 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid} was similar with spray volumes of 50, 185, and 360 L/ha. Application of DPX-F6025 {ethyl ester of 2-[[[[(4-chloro-6-methoxypyrimidin-2-yl) amino] carbonyl] amino] sulfonyl] benzoate} in 50 L/ha resulted in greater control than application in 185 or 360 L/ha in the greenhouse, but no effect of spray volume was noted in field studies. In the greenhouse, control was 25 and 63% less with imazaquin applied to three- and five-leaf plants, respectively, compared to one-leaf plants; control was 40 and 62% less with DPX-F6025 applied to three- and five-leaf plants, respectively, compared to one-leaf plants. In the field, initial control was greater with imazaquin and DPX-F6025 applied to one-leaf plants than to three- or five-leaf plants. Following cultivation, control was similar regardless of plant size at time of application. In the field, postemergence applications of imazaquin and DPX-F6025 were equally phytotoxic following preplant-incorporated application of vernolate (S-propyl dipropylcarbamothioate) or preemergence application of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide]. A synergistic interaction was observed in the greenhouse with imazaquin applied postemergence to sicklepod grown in vernolate- or alachlor-treated soil and with DPX-F6025 applied to sicklepod grown in alachlor-treated soil. Antagonism was observed with DPX-F6025 applied postemergence to sicklepod grown in vernolate-treated soil.
Wild Mustard (Sinapis arvensis) Control in Sunflowers (Helianthus annuus) with Fluorochloridone
Authors: Friesen George H.
Published: May 2019

Fluorochloridone {3-chloro-4-(chloromethyl)-1-[3-(trifluoromethyl)phenyl]-2-pyrrolidinone} effectively controlled wild mustard (Sinapis arvensisL. # SINAR) in sunflowers (Helianthus annuusL. ‘Hybrid 894′). Preemergence (pre) treatments were more effective than preplant-incorporated (ppi) treatments at rates of 0.3 to 1.1 kg ai/ha. Applied as a foliar spray, fluorochloridone at rates of 0.12 to 0.25 kg ai/ha controlled 96% or more of wild mustard but some crop injury occurred. When fluorochloridone was mixed with trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] or EPTC (S-ethyl dipropyl carbamothioate) and applied ppi, several annual grasses as well as wild mustard were controlled.
Effect of Three Formulations on Uptake and Efficacy of Copper inHydrilla verticillata
Authors: Anderson Lars W.J. , Dechoretz Nathan , Bayer David , Darmstadt Gary L.
Published: May 2019

Copper content and growth of excised hydrilla [DioeciousHydrilla verticillata(L.f.) Royle # HYLLI] apical shoot segments were determined following exposure to copper sulfate (CuSO4), copper-triethanolamine (Cu-TEA), and copper-ethylenediamine (Cu-EDA). For all copper formulations, inhibition of growth was related to the amount of copper associated with the excised shoots. At equal copper exposure, the Cu-EDA formulation produced the greatest inhibition of growth and generally the highest copper levels in the plants. The Cu-EDA formulation inhibited dry weight gain by more than 80% 3 weeks after a 2-h exposure to 2.0 or 4.0 ppmw copper. Under similar conditions, CuSO4or Cu-TEA produced 60% inhibition. The presence or absence of light during a 2-h exposure had no effect on the efficacy of uptake of copper from any of the formulations. Formulation-dependent differences in the mechanism of copper uptake is suggested because rinsing of exposed shoots with dilute acid (0.01N HNO3) removed copper from shoots treated with CuSO4or Cu-TEA but not from those treated with Cu-EDA.
Robust Semantic Mapping in Challenging Environments
Authors: Cheng Jiyu , Sun Yuxiang , Meng Max Q.-H.
Published: May 2019

Visual simultaneous localization and mapping (visual SLAM) has been well developed in recent decades. To facilitate tasks such as path planning and exploration, traditional visual SLAM systems usually provide mobile robots with the geometric map, which overlooks the semantic information. To address this problem, inspired by the recent success of the deep neural network, we combine it with the visual SLAM system to conduct semantic mapping. Both the geometric and semantic information will be projected into the 3D space for generating a 3D semantic map. We also use an optical-flow-based method to deal with the moving objects such that our method is capable of working robustly in dynamic environments. We have performed our experiments in the public TUM dataset and our recorded office dataset. Experimental results demonstrate the feasibility and impressive performance of the proposed method.
Three-Dimensional Reconstruction Based on Visual SLAM of Mobile Robot in Search and Rescue Disaster Scenarios
Authors: Wang Hongling , Zhang Chengjin , Song Yong , Pang Bao , Zhang Guangyuan
Published: May 2019

Conventional simultaneous localization and mapping (SLAM) has concentrated on two-dimensional (2D) map building. To adapt it to urgent search and rescue (SAR) environments, it is necessary to combine the fast and simple global 2D SLAM and three-dimensional (3D) objects of interest (OOIs) local sub-maps. The main novelty of the present work is a method for 3D OOI reconstruction based on a 2D map, thereby retaining the fast performances of the latter. A theory is established that is adapted to a SAR environment, including the object identification, exploration area coverage (AC), and loop closure detection of revisited spots. Proposed for the first is image optical flow calculation with a 2D/3D fusion method and RGB-D (red, green, blue + depth) transformation based on Joblove–Greenberg mathematics and OpenCV processing. The mathematical theories of optical flow calculation and wavelet transformation are used for the first time to solve the robotic SAR SLAM problem. The present contributions indicate two aspects: (i) mobile robots depend on planar distance estimation to build 2D maps quickly and to provide SAR exploration AC; (ii) 3D OOIs are reconstructed using the proposed innovative methods of RGB-D iterative closest points (RGB-ICPs) and 2D/3D principle of wavelet transformation. Different mobile robots are used to conduct indoor and outdoor SAR SLAM. Both the SLAM and the SAR OOIs detection are implemented by simulations and ground-truth experiments, which provide strong evidence for the proposed 2D/3D reconstruction SAR SLAM approaches adapted to post-disaster environments.