bluuebunny/crossref_metadata_2025 huggingface dataset:
Information technologies in graphic disciplines of technical university
Authors: Гузненков  , Guznenkov Vladimir
Published: January 2014

A structure and content of graphics teaching at technical

university with information technologies use are considered

in this paper. The necessity to meet the requirements related to

information support of products’ life cycle is marked. Educational

disciplines of graphic teaching in technical university have been

considered and defined. It has been noted that the main feature of

modern graphic teaching is a 3D-modeling, and the main purpose

of graphics teaching upgrading is a significant increase in the quality

of training without increasing the number of training hours.

From this it follows that the basic requirement for the geometrical

graphics training is significant expansion of modeling volume.
Information support in modern technologies of graphic disciplines training
Authors: Новожилова  , Novozhilova S. , Егорычева  , Egorycheva E.
Published: January 2014

The paper is devoted to the solution of an actual task

on improvement of technologies related to training in «Engineering

Graphics» course that is in turn inseparably linked with application

of information technologies’ complex means. Creation and use of

computer textbook on construction and technical plotting which

can be used during performing of tasks on construction plotting,

and also during performing of academic year and degree projects

by students of all specialties are considered in this work.
Specifics of design documentation development in production automation conditions
Authors: Асекритова  , Asekritova Svetlana , Константинов  , Konstantinov A.
Published: January 2014

The methodology related to constructing of integrated

automation system (IAS) of production activities, as well as

its main directions are considered in this paper. The analysis of

different methods and technologies for complex automation of the

enterprises on the basis of various software products is performing.

The paper is also devoted to problems of design and technological

training of specialists which manage the modern technologies in design area. Interstate standards establishing uniform requirements

for such computer design development as «Electronic Documents»,

«Electronic Model of Product» and «Electronic Structure of Product»

are considered in detail.
Academic competitions’ functions
Authors: Вышнепольский  , Vyshnyepolskiy Vladimir
Published: January 2014

Issues of academic competitions’ preparation and carrying are of great scientific and practical interest. A large number of papers devoted to academic competitions have been published in recent years. Developments devoted to academic competitions’ functions are of interest. Subject academic competitions’ 22 functions grouped into six main ones (humanistic, creative, motivation of educational activity, organizational, controlling, representative) are considered in the present paper.
Gaspard Monge’s Descriptive Geometry Course
Authors: Сальков  , Sal'kov Nikolay
Published: January 2014

The structure of course of lectures, proposed by Gaspard

Monge in the late 18th century, is considered in detail. Monge

foresees 120 lectures for descriptive geometry. The main course,

without shadows and perspective, is divided into 5 sections, each

of which is devoted to a certain themes. In the first section the

projections deriving is described, and two main goals are given.

Here we face with the notion of geometric locus, elements of differential

and projective geometries. The second section considers

the tangent planes and normals. These elements’ use in painting

and building are demonstrated. The third section has been devoted

to the theory related to construction of curved surfaces intersections.

The solution of tasks has been considered in the fourth section.

The fifth section has been devoted to the curved lines. Gaspard

Monge proposes the developed course of descriptive geometry not

as a set of interesting geometric tasks, but as a solution of specific

application tasks inherent to the industry, building, art, and military

science.
Legal Regulation of the Human Use of Organs, Tissues and Cells of Animals
Authors: Maleina Marina
Published: January 2014

The article deals with problem of the legal regulation of the use of human organs, tissues and cells of animals for medical treatment (xenotransplantation), breeding of new species as an experiment or for other purposes. There are formulated the legal conditions for xenotransplantation and bans of the use of organs of animals.
Special Principles of Qualification of Crimes
Authors: Marchuk Vasiliy
Published: January 2014

The analysis of the criminally-legal literature by special principles of qualification of crimes is carried out. The criticism of scientific positions on this question is stated. Substantiated conclusions about necessity of allocation of following principles of qualification of crimes: comparability, scientific character, sufficiency, interpretation of ineradicable doubts in favor of the accused.
Approximation Algorithm for the Stochastic Multiperiod Inventory Problem via a Look-Ahead Optimization Approach
Authors: Truong Van-Anh
Published: January 2014

We consider the single-item, multiperiod stochastic inventory problem with nonstationary and correlated demands. We provide the first proof that a well-known myopic policy, which we call look-ahead optimization (LA), is in fact an approximation algorithm for solving the large dynamic program that arises from this problem. We prove that LA provides the tightest known approximation bound for this problem. The expected cost of LA is at most twice the expected holding cost plus the expected backorder cost of an optimal policy. We introduce a new cost-accounting technique and a new class of invariances on the ongoing performance of LA relative to that of an optimal policy. We use these invariances to extend the myopic optimality of LA to a global bound on its performance. We allow convex and nonlinear holding and backorder cost functions, integral order quantities, and positive lead times under a technical condition on the growth of demand. We show in computational experiments that LA has excellent average-case performance.
Ice Crawlers (Grylloblattodea) – the history of the investigation of a highly unusual group of insects
Authors: Wipfler Benjamin , Bai Ming , Schoville Sean , Dallai Romano , Uchifune Toshiki , Machida Ryuichiro , Cui Yingying , Beutel Rolf G.
Published: January 2014

Grylloblattodea are one of the most unusual groups of insects and the second smallest order. All known extant species are wingless and exhibit a remarkable preference for cold temperatures. Although their morphology was intensively investigated shortly after their discovery, the systematic position has been disputed for a long time. The placement of Grylloblattodea as sister-group to the recently described Mantophasamtodea is supported by morphological and molecular evidence. However, the relationships of this clade, Xenonomia, among the polyneopteran lineages is not clear. Transcriptome analyses, in addition to the study of winged grylloblattodean fossils, may help to clarify the position of Xenonomia and aid in the reconstruction of the “phylogenetic backbone” of Polyneoptera.
On the continuity of solutions to advection-diffusion equations
with slightly super-critical divergence-free drifts
Authors: Ignatova Mihaela
Published: January 2014

We address the regularity of solutions to elliptic and parabolic equations of the form

-
Δ
u
+
b
·
∇
u
=
0

${- \Delta u+b\cdot \nabla u=0}$

and

u
t

-
Δ
u
+
b
·
∇
u
=
0

${u_t- \Delta u+b\cdot \nabla u=0}$

with divergence-free drifts b. We are particularly interested in the case when the drift velocity b is assumed to be at the supercritical regularity level with respect to the natural scaling of the equations. Using Harnack-type inequalities obtained in our previous works [`The Harnack inequality for second-order elliptic equations with divergence-free drift', Commun. Math. Sci., to appear] and
[`The Harnack inequality for second-order parabolic equations with
divergence-free drifts of low regularity', preprint (2013)], we prove the uniform continuity of solutions when the drift b lies in a slightly supercritical logarithmic Morrey spaces.
On nonlinear potential theory, and regular boundary
points, for the p-Laplacian in N space variables
Authors: Beirão da Veiga Hugo
Published: January 2014

We turn back to some pioneering results
concerning, in particular, nonlinear potential theory and
non-homogeneous boundary value problems for the so-called
p-Laplace operator. Unfortunately these results, obtained at the
very beginning of the seventies, were kept in the shade. We believe
that our proofs are still of interest, in particular due to their
extreme simplicity. Moreover, some contributions seem to improve the
results quoted in the current literature.
Meta-analysis: diagnostic accuracy of anti-cyclic citrullinated peptide 2 antibody and anti-cyclic citrullinated peptide 3 antibody in rheumatoid arthritis
Authors: Zhang Wen-Chao , Wu Han , Chen Wei-Xian
Published: January 2014

The aim of this work was to assess the diagnostic value of anti-CCP-3 and anti-CCP-2 for the diagnosis of rheumatoid arthritis (RA) and determine whether anti-CCP-3 more accurately identifies patients with rheumatoid arthritis than anti-CCP-2. PubMed and CNKI databases were searched for studies published in English and Chinese that examined the use of anti-CCP-3 and anti-CCP-2 in the diagnosis of known or suspected rheumatoid arthritis from January 2006 to July 2013. Seventeen included studies of methodological quality were rated by using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tools A random-effects method was used to summarize sensitivities, specificities, positive and negative likelihood ratio (LR+ and LR−, respectively), and diagnostic odds ratio from 17 studies. The pooled sensitivity, specificity, LR+, LR− and diagnostic odds ratio for anti-CCP-3 were 0.737 (95% CI, 0.717–0.757), 0.933 (95% CI, 0.924–0.942), 11.096 (95% CI, 8.876–13.870), 0.274 (95% CI, 0.231–0.326), and 42.908 (95% CI, 33.828–54.426), respectively. For anti-CCP-2, the values were 0.719 (95% CI, 0.699–0.739), 0.960 (95% CI, 0.953–0.966), 17.485 (95% CI, 11.960–25.562), 0.294 (95% CI, 0.258–0.335) and 63.458 (95% CI, 44.214–91.078), respectively. With high specificity and moderate sensitivity, anti-CCP-2 and anti-CCP-3 played an important role in confirming the diagnosis of RA. Anti-CCP-3 did not have better diagnostic performances than anti-CCP-2, but anti-CCP-2 had evident heterogeneity compared to anti-CCP-3, especially in American patients.
Stability of Petrov–Galerkin Discretizations: Application to the Space-Time Weak Formulation for Parabolic Evolution Problems
Authors: Mollet Christian
Published: January 2014

This paper is concerned with the stability of Petrov–Galerkin discretizations with application
to parabolic evolution problems in space-time weak form.
We will prove that the discrete inf-sup condition for an a priori fixed Petrov–Galerkin discretization
is satisfied uniformly under standard approximation and smoothness
conditions without any further coupling between the discrete trial and test spaces
for sufficiently regular operators.
It turns out that one needs to choose different discretization levels for the trial and test spaces
in order to obtain a positive lower bound for the discrete inf-sup condition
which is independent of the discretization levels.
In particular, we state the required number of extra layers in order to guarantee uniform boundedness of the discrete inf-sup constants explicitly. This general result will be applied to
the space-time weak formulation of parabolic evolution problems as an important model example.
In this regard, we consider suitable hierarchical
families of discrete spaces.
The results apply, e.g., for finite element discretizations as well as for wavelet discretizations.
Due to the Riesz basis property, wavelet discretizations allow for optimal
preconditioning independently of the grid spacing.
Moreover, our predictions on the stability, especially in view of
the dependence on the refinement levels w.r.t. the test and trial
spaces, are underlined by numerical results.
Furthermore, it can be observed that choosing the same discretization levels
would, indeed, lead to stability problems.
Morphological, thermal, and structural aspects of dried and redispersed nanofibrillated cellulose (NFC)
Authors: Žepič Vesna , Fabjan Erika Š. , Kasunič Marta , Korošec Romana C. , Hančič Aleš , Oven Primož , Perše Lidija S. , Poljanšek Ida
Published: January 2014

The effects of various drying techniques, such as air, oven, freeze, and spray drying, on the morphological, thermal, and structural behaviors of two different nanofibrillated cellulose (NFC) materials were investigated. Field emission scanning electron microscopy (FE-SEM) observations indicated an interlaced network formation of predominantly in-plane fibrillar orientation for air- and oven-dried samples, while freeze and spray drying resulted in the formation of coarse and fine powder fractions. Comparison of redispersed powders obtained by freeze and spray drying indicated that aggregation phenomena are significantly reduced in freeze-dried specimens. Rheological and sedimentation analysis revealed that the freeze-dried NFC powders are more stable than spray-dried NFC powders when redispersed in water. Aggressive dehydration processes, such as freezing or heating, significantly influence the thermal stability of the dried cellulose samples. On the contrary, the crystallinity properties of dried NFC materials are very similar regardless of the drying treatment.
Finite element modeling and experimental validation of radio frequency heating (RFH) of curved laminated wood-based panels
Authors: Zhou Jianhui , Hu Chuanshuang , Ma Xiaoying , Guo Xingwei
Published: January 2014

Thin medium-density fiberboards (MDF) are often used for the production of curved laminated furniture components by post-hot pressing with radiofrequency heating (RFH). Dimensional instability is one of the major quality problems of these products, and inappropriate heating process was discussed as the main reason for this. In the present study, a finite element model (FEM) was developed in this context, and the temperature distribution within laminated MDF panels was predicted aiming at optimizing the hot-pressing process with RFH. The time-dependent temperatures were collected by temperature sensing strips (TSS). The results agreed well with those obtained by the simulation model. Accordingly, the FEM developed here is well suited for predicting the heating behavior during hot pressing with RFH. The temperature distribution of the curved laminated MDF panels was not symmetric and not uniform because of curved shape effects and the heat convection between MDF panels and ambient air. The time-dependent temperatures of the top and bottom layers were lower than that of the core layer.
The Effect of Error-in-Confounders on the Estimation of the Causal Parameter When Using Marginal Structural Models and Inverse Probability-of-Treatment Weights: A Simulation Study
Authors: Regier Michael D. , Moodie Erica E. M. , Platt Robert W.
Published: January 2014

We performed an empirical study to evaluate the effect of mismeasured continuous confounders on the estimation of the causal parameter when using marginal structural models and inverse probability-of-treatment weighting. By executing an extensive simulation using 500 randomly generated parameter value combinations within a defined space, we observed the well-understood effects of attenuation and augmentation, and two unanticipated effects: null effects and sign reversals. We implemented a secondary empirical study to further investigate the sign reversal effect. We use the results of our study to identify conceptual similarities between the analytic and empirical results for multivariable linear and logistic regression, and our empirical results. Through this synthesis, we have been able to suggest feasible directions of research as well as outline the form of expected results.
Microwave, Air and Combined Microwave-Air Drying of Grape Leaves (Vitis vinifera L.) and the Determination of Some Quality Parameters
Authors: Alibas Ilknur
Published: January 2014

Grape leaves (Vitis vinifera L.) weighing 50 g (±0.08) with a moisture of 4.08 kg(moisture) kg−1
(dry matter) (75.35% wb) were dried using three different drying methods: microwave, air and combined microwave-air. Drying continued until the leaf moisture decreased to 0.14 (±0.01) kg(moisture) kg−1
(dry matter) (9.07% (±0.20) wb). Drying periods lasted 5–11, 30–70 and 1.5–6 min for microwave, air and combined microwave-air drying, respectively, depending on the drying level. In this study, measured values of moisture were compared with values of predicted obtained from several thin-layer equations; the Alibas Model was found to have the best fit. The optimum drying period, color and ascorbic acid content were obtained by using the combined microwave-air drying method with the optimum combination of 500 W of microwave power at a temperature of 75°C.
Experimental Analysis and Numerical Modeling of Microwave Reheating of Cylindrically Shaped Instant Rice
Authors: Fan Daming , Li Chunxiang , Li Yi , Chen Wei , Zhao Jianxin , Hu Manfeng , Zhang Hao
Published: January 2014

The purpose of this study was to develop a numerical model to predict the temperature distribution in cylindrically shaped cooked rice samples during microwave reheating and to give impetus to a uniform microwave-heating design. Cylindrically shaped instant rice was reheated by continuous microwave application, and the sample temperature was measured to determine the internal temperature profile which resulted in a desired uniformity of temperature observed using the non-uniformity temperature evaluation. A finite difference method was used to predict the temperature distribution of the cylindrical rice during microwave reheating and applying Lambert’s law to calculate the microwave power absorption in a large sample of cylindrically shaped instant rice. In order to solve the numerical model of heat transfer, the thermal and dielectric properties of instant rice were measured with respect to temperature. Our results showed that the temperature had a significant effect on the specific heat and dielectric loss of rice, while the thermal conductivity and dielectric constant were unaffected. The numerically predicted temperature distributions were in good agreement with the measured ones of instant rice.
Collision bounds for the additive Pollard rho algorithm for solving discrete logarithms
Authors: Bos Joppe W. , Dudeanu Alina , Jetchev Dimitar
Published: January 2014

We prove collision bounds for the Pollard rho algorithm to solve the discrete logarithm
problem in a general cyclic group

𝐆

$\mathbf {G}$

. Unlike the setting studied by Kim et al.,
we consider additive walks: the setting used in practice to solve the elliptic curve discrete logarithm problem.
Our bounds differ from the birthday bound

𝒪
(

|
𝐆
|

)

$\mathcal {O}(\sqrt{\vert \mathbf {G}\vert })$

by a factor of

log

|
𝐆
|

$\sqrt{\log {\vert \mathbf {G}\vert }}$

and are based on mixing time estimates for random
walks on finite abelian groups due to Dou and Hildebrand.
The Birth of a Democracy: Homegrown Bicameralism in Somaliland
Authors: Azam Jean-Paul
Published: January 2014

Somaliland has recently developed an unexpected democracy after seceding from chaos-ridden Somalia, while turning its port of Berbera into a success story, competing successfully with the long established ones in the Horn of Africa. A simple game-theoretic model is used to explain why the home-grown bicameral democratic system that emerged in Somaliland is a key factor in controlling violence and providing the required security along the transport infrastructure linking Berbera to neighboring landlocked Ethiopia. The model shows that redistributing some of the fiscal resources levied on this trade is necessary for sustaining this efficient political equilibrium.
Assessment and influence of internal rigid core on the contact parameters for soft hemispherical fingertips
Authors: Raja K. Venkatesh , Malayalamurthi R.
Published: January 2014

The main purpose of the present work is to develop an artificial fingertip comprised of a soft layer and an inner rigid core, which emulates a human one with skin and bone. The influences of introducing the core and the effects of variations in thickness of the soft layer over the contact parameters are investigated. From the results, it is evident that the power law theory proposed by (Xydas N, Kao I. Int. J. Rob. Res. 1999, 18, 941–950) becomes invalid in this criterion; by contrast, if the power law theory acts for finger tips with internal cores, the conclusion may be redefined in such a way that the soft material behaves more softly in the presence of internal cores and the dimensionless number, core-soft layer coefficient Fcs≈0.5, is the critical parameter which produces the change of behavior. Moreover, soft finger tips with an inner core are preferable to entirely soft ones, as a higher grasping stability is achieved with the same area of contact, and the conforming nature of the fingers is maintained.
Synthesis and properties of acrylamide 2-acrylamido-2-methypropane sulfonic acid sodium styrene sulfonate N-vinyl pyrrolidone quadripolymer and its reduction of drilling fluid filtration at high temperature and high salinity
Authors: Li Zhijun , Pu Xiaolin , Tao Huaizhi , Liu Lu , Su Junlin
Published: January 2014

Acrylamide (AM), 2-acrylamido-2-methypropane sulfonic acid, sodium styrene sulfonate (SSS), and N-vinyl pyrrolidone (NVP) monomers were copolymerized via a redox initiator system to synthesize a quadripolymer capable of reducing drilling fluid filtration. Fourier transform infrared spectroscopy (FT-IR) was used to determine the molecular structure of the product, confirming its successful synthesis. The effects of the copolymer on the properties and salt resistance of drilling fluid are discussed. The adsorption of the copolymer on bentonite was also studied using atomic force microscopy (AFM). The copolymer reduced the filtration of drilling fluids of various salinities before and after aging at 200°C; at room temperature, the copolymer was adsorbed uniformly across the bentonite surface at low concentration. As its concentration increased, the distributed polymer spread and connected to form a network. After aging for 16 h at 200°C, the copolymer could still adsorb to bentonite and maintained its network structure. Sodium ions induced the coalescence of the copolymer, damaging its network structure.
Synthesis, radiolabeling and in vivo biological evaluation of 99mTc-labeled MAG3-based
bisnitroimidazole complexes as tumor hypoxia markers
Authors: Mei Lei , Chu Taiwei
Published: January 2014

Hypoxia, as a common phenomenon in solid tumors, is of interest for its relationship with resistance to tumor therapies and
malignant progression of tumor. The noninvasive nuclear medical imaging technique using hypoxia markers is an important method for the
detection of tumor hypoxia. The aim of current study is designing tumor hypoxia markers with hypoxia selectivity and improved
properties. Two MAG3-based bisnitroimidazole compounds were synthesized and purified by semi-preparative HPLC. Both the MAG3
derivatives were labeled with 99mTc-oxo-technetium core via stannous tartrate exchange method in high yields
(> 95%). The 99mTc-MAG3 complexes were stable at 37 ℃, 4 h after
preparation, and were more hydrophilic than 99mTc-MAMA complexes. As biodistribution results showed, clearances of
background activity for both the complexes were fast and they were excreted mainly through the hepatobiliary tract and part of renal
tract. Although tumor uptakes of 99mTc-MAG3-B2NIL were lower than those of
99mTc-MAG3-B4NIL, tumor-to-blood ratios of 99mTc-MAG3-B2NIL showed an increasing trend
and were better than those of 99mTc-MAG3-B4NIL after 2 h due to their different blood
clearances. Tumor-to-muscle ratios of 99mTc-MAG3-B2NIL and 99mTc-MAG3-B4NIL were
similar. Comparing with 99mTc-MAMA complexes, 99mTc-MAG3-B2NIL with better tumor-to-blood
ratios exhibits improved feature for hypoxia imaging, though it has lower tumor uptake than 99mTc-MAMA complexes.
A density functional theory study of the competitive complexation of
pyridine against H2O and Cl−− to Cm3+ and Ce4+
Authors: Wang Zhuxiang , Chu Taiwei , Chai Zhifang , Wang Dongqi
Published: January 2014

Density functional theory was used to study the coordination
of Cm3+ and Ce4+ with pridine (Py), water (H2O) and chloride
anion (Cl−). The competitive coordination of Cl− and Py was
investigated to simulate the ligand exchange between Cl− and Py at high
concentration of hydrochloric acid (HCl), where Cm3+ and Ce4+ may
exist in the form of [CmCl6]3− and [CeCl6]2−, while that
of water and Py to simulate the process at low concentration or without the
presence of Cl−.

The calculations show that Ce4+ has higher affinity to Py than
Cm3+ in the absence of Cl−, while it binds much more weakly at
high concentration of HCl. This is consistent with experimental data that at
high concentration of HCl, Ce4+ has much shorter retention time than
Cm3+ using tertiary pyridine resin (TPR). In view of the strengthening
of M-Cl and the weakening of M-OW at bonds upon the coordination of Py, we
conclude that the distinct coordination abilities of the three ligands to
Ce4+ and Cm3+ are due to different strengths of the inner-shell
electrostatic interaction between the ligands and the central metal ions.
An advanced purex process based on salt-free reductants
Authors: Hui He , Guoan Ye , Hongbin Tang , Weifang Zheng , Gaoliang Li , Rushan Lin
Published: January 2014

An advanced plutonium and uranium recovery process has been
established based on two organic reductants, N,N-dimethylhydroxylamine (DMHAN)
and methylhydrazine (MH), as U/Pu separation reagents. This Advanced Purex
process based on Organic Reductants (APOR) is composed of three cycles,
including U/Pu co-decontamination/separation cycle, uranium purification
cycle and plutonium purification cycle. Using DMHAN and MH as plutonium
stripping reagents in the U/Pu co-decontamination/separation cycle and
plutonium purification cycle, the APOR process exhibits high performance
with following highlights: 1) the process is much simpler because of the
elimination of Tc scrubbing operation and the supplement extraction
operation, 2) high efficiency of U/Pu separation can be achieved in the
first cycle, 3) plutonium product solution of high concentration can be
obtained in the Pu purification cycle with a simple extraction operation
instead of circumfluent extraction or evaporation of the plutonium solution.
Nitrate conversion and supercritical fluid extraction of UO2-CeO2 solid solution prepared by an electrolytic
reduction-coprecipitation method
Authors: Zhu L. Y. , Duan W. H. , Wen M. F. , Xu J. M. , Zhu Y. J.
Published: January 2014

A low-waste technology for the reprocessing of spent nuclear fuel (SNF) has been developed recently, which involves the
conversion of actinide and lanthanide oxides with liquid N2O4 into their nitrates followed by supercritical fluid extraction
of the nitrates. The possibility of the reprocessing of SNF from high-temperature gas-cooled reactors (HTGRs) with nitrate conversion
and supercritical fluid extraction is a current area of research in China. Here, a UO2-CeO2 solid solution was prepared as
a surrogate for a UO2-PuO2 solid solution, and the recovery of U and Ce from the UO2-CeO2 solid solution with
liquid N2O4 and supercritical CO2 containing tri-n-butyl phosphate (TBP) was investigated. The UO2-CeO2 solid
solution prepared by electrolytic reduction-coprecipitation method had square plate microstructures. The solid solution after heat
treatment was completely converted into nitrates with liquid N2O4. The XRD pattern of the nitrates was similar to that of
UO2(NO3)2 ·3H2O. After 120 min of online extraction at 25 MPa and 50 ℃,
99.98% of the U and 98.74% of the Ce were recovered from the nitrates with supercritical CO2 containing TBP. The
results suggest a promising potential technology for the reprocessing of SNF from HTGRs.
Zeolite-encapsulated transition metal chelates: synthesis and characterization
Authors: Ahmed Ayman H.
Published: January 2014

This article reviews some important recent works on the synthesis and characterization of zeolite-encapsulated transition metal complexes containing different organic ligands. Distinct methodologies of preparation, including the in situ one-pot template (IOPT) and flexible ligand methods (FLM) are described. The mode of bonding, composition, overall geometry and surface characteristics have been inferred by various physicochemical characterization techniques. Chemical analysis, spectroscopic methods [Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS) and ultraviolet-visible (UV-Vis)], scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive spectroscopy analysis of X-ray (EDAX), magnetic measurements, N2-adsorption-desorption and thermogravimetric studies have been proven to be powerful techniques to specify these host-guest nanocomposite materials (HGNM). In some cases, Mössbauer, photoluminescence and cyclic voltammetric data are informative. Recent results dealing with the immobilization of complexes concerning aza, heterocyclic, Schiff base and hydrazone ligands are presented. A comprehensive survey of the investigated materials manifested the successful incorporation of the complexes into the zeolite matrix, without collapsing the crystalline structure of zeolite. Occasionally, some of the encapsulated complexes showed structural properties and chemical behavior which are different from those of the neat complex owing to the zeolite constraints.
2 : 1 Co-crystals of p-nitrophenylacetic acid with three isomeric n-pyridinealdazines, n = 2, 3 and 4, featuring the {… HOCO … N(py)} heterosynthon
Authors: Arman Hadi D. , Kaulgud Trupta , Miller Tyler , Tiekink Edward R. T.
Published: January 2014

Crystal and molecular structures of 2 : 1 co-crystals formed between p-nitrophenylacetic acid and three isomeric n-pyridinealdazines, n = 2(1), 3(2) and 4(3), are described in which the carboxylic acid is always in a general position and the respective n-pyridinealdazine is located about a centre of inversion. A common feature of the supramolecular aggregation is the formation of three-molecule aggregates sustained by the {… HOCO … N(py)} heterosynthon, further vindicating this as a most reliable synthon for co-crystal design. Molecules are assembled into three-dimensional architectures by C–H … O interactions coupled with C–H … π (1) or π … π (2 and 3) contacts.
Conformation differences in N-[2-(1-arenesulfonyl-1H-pyrazol-3-yl)-6-methyl-phenyl]-arenesulfon­amides, (arene = benzene and 4-toluene)
Authors: Borges Julio C. , Pinheiro Luiz C. S. , Faria Jéssica V. , Bernardino Alice M. R. , Wardell James L. , Wardell Solange M. S. V.
Published: January 2014

The crystal structures are reported of N-[2-(1-benzenesulfonyl-1H-pyrazol-3-yl)-6-methyl-phenyl]-benzenesulfonamide, 1, and N-[2-(1-toluene-4-sulfonyl-1H-pyrazol-3-yl)-6-methyl-phenyl]-benzenesulfonamide, 2: two compounds used in a recently reported antileishmania study. The crystallographic study reveals significant differences in the conformations adopted by molecules of 1 compared to those adopted by the three independent molecules of 2 in the solid state. The conformation differences between molecules of 1, on one hand, and the three molecules of 2, on the other, are not driven by steric effects within the molecular arrangements. If molecules 2 adopted the molecular conformation found for 1, severe steric interference would occur in the chains and other aggregates generated from the intermolecular contacts. As all the intermolecular interactions are of a weak nature, it is unlikely that aggregation would survive in dilute aqueous media, and hence the steric constraints on the conformations adopted in the solid state would not be in place in solution. Thus the difference in the solid state conformations offers no light on the greater activity of compound 1 compared to that of compound 2 in the antileishmania study in aqueous media.
Free-Weight Augmentation With Elastic Bands Improves Bench Press Kinematics in Professional Rugby Players
Authors: García-López David , Hernández-Sánchez Sonsoles , Martín Esperanza , Marín Pedro J. , Zarzosa Fernando , Herrero Azael J.
Published: January 2014

García-López, D, Hernández-Sánchez, S, Martín, E, Marín, PJ, Zarzosa, F, and Herrero, AJ. Free-weight augmentation with elastic bands improves bench press kinematics in professional rugby players. J Strength Cond Res 30(9): 2493–2499, 2016—This study aimed to investigate the effects of combining elastic bands to free weight resistance (EB + FWR) on the acceleration-deceleration and velocity profiles of the bench press in professional rugby players and recreationally trained subjects. Sixteen male subjects (8 rugby players and 8 recreationally trained subjects) were randomly assigned to complete 2 experimental conditions in a crossover fashion: EB + FWR and FWR. In both conditions, subjects performed 1 bench press set to volitional exhaustion with a load equivalent to the 85% of 1 repetition maximum (1RM). In the EB + FWR condition, the contribution of elastic resistance was approximately 20% of the selected load (85% 1RM). Results indicate that EB + FWR condition increased significantly the range of concentric movement in which the barbell is accelerated. This increase was significantly higher in rugby players (35%) in comparison with recreationally trained subjects (13%). Maximal velocity was also increased in EB + FWR (17%), when compared with FWR condition. These results suggest that when combined with variable resistance (i.e., EB), the external resistance seems to be more evenly distributed over the full range of motion, decreasing the need for dramatic deceleration at the end of the concentric phase. The present data also indicate that the kinematic benefits of an EB + FWR approach seems to be more prominent in athletes from modalities in which high level of strength and power are required (i.e., rugby players).
Molecular Dynamics Simulation on Σ5 Grain Boundaries of Copper Bicrystal under Tensile and Shear Deformation
Authors: Zhang Liang. , Lu Cheng. , Tieu Kiet.
Published: January 2014

Molecular Dynamics simulation are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric Σ5[0 0 1] tilt grain boundaries (GBs) of copper bicrystal under uniaxial tension and shear deformation. Simulation results indicate that the Σ5 asymmetric GBs can facet into their corresponding symmetric GB structures. The maximum tensile stress of symmetric GBs is higher than the asymmetric ones at both 10 K and 300 K, which suggests the symmetric GBs may have a more stable boundary structures. All the Σ5 GBs investigate in this study can migrate under the shear deformation with different velocity. The migration of Σ5 symmetric GBs is realized by uniform displacement of local atoms and rotation of the atomic group in “E” structural unit, while for the asymmetric GBs, the migration is identified to be a diffusion-related process result from local atoms shuffling.
Modification of the Dingman Mouth Gag for Better Visibility and Access in the Management of Cleft Palate
Authors: Rao Latha P. , Peter Sherry
Published: January 2014

Palatal and pharyngeal surgeries often require wide visibility and access. Various mouth gags and retractors have been devised and many modifications suggested to optimize these surgeries. The Dingman mouth gag, one of the commonly used retractors, offers a lot of advantages in terms of good mouth opening, tongue retraction, self-retaining cheek retractors, and anchorage for sutures, but it has a main limitation in that it allows only limited visibility of the anterior palate and alveolus. Hence, a modification of the Dingman mouth gag is presented for better visibility of and accessibility to the anterior palate.
Prediction of fishing effort distributions using boosted regression trees
Authors: Soykan Candan U. , Eguchi Tomoharu , Kohin Suzanne , Dewar Heidi
Published: January 2014

Concerns about bycatch of protected species have become a dominant factor shaping fisheries management. However, efforts to mitigate bycatch are often hindered by a lack of data on the distributions of fishing effort and protected species. One approach to overcoming this problem has been to overlay the distribution of past fishing effort with known locations of protected species, often obtained through satellite telemetry and occurrence data, to identify potential bycatch hotspots. This approach, however, generates static bycatch risk maps, calling into question their ability to forecast into the future, particularly when dealing with spatiotemporally dynamic fisheries and highly migratory bycatch species. In this study, we use boosted regression trees to model the spatiotemporal distribution of fishing effort for two distinct fisheries in the North Pacific Ocean, the albacore (Thunnus alalunga) troll fishery and the California drift gillnet fishery that targets swordfish (Xiphias gladius). Our results suggest that it is possible to accurately predict fishing effort using <10 readily available predictor variables (cross‐validated correlations between model predictions and observed data ∼0.6). Although the two fisheries are quite different in their gears and fishing areas, their respective models had high predictive ability, even when input data sets were restricted to a fraction of the full time series. The implications for conservation and management are encouraging: Across a range of target species, fishing methods, and spatial scales, even a relatively short time series of fisheries data may suffice to accurately predict the location of fishing effort into the future. In combination with species distribution modeling of bycatch species, this approach holds promise as a mitigation tool when observer data are limited. Even in data‐rich regions, modeling fishing effort and bycatch may provide more accurate estimates of bycatch risk than partial observer coverage for fisheries and bycatch species that are heavily influenced by dynamic oceanographic conditions.
Multiple diversity–stability mechanisms enhance population and community stability in aquatic food webs
Authors: Downing Amy L. , Brown Bryan L. , Leibold Mathew A.
Published: January 2014

Biodiversity has been shown to increase the temporal stability of community and ecosystem attributes through multiple mechanisms, but these same mechanisms make less consistent predictions about the effects of richness on population stability. The overall effects of biodiversity on population and community stability will therefore depend on the dominant mechanisms that are likely to vary with the nature of biodiversity loss and the degree of environmental variability. We conducted a mesocosm experiment in which we generated a gradient in zooplankton species richness by directly manipulating dominant species and by allowing/preventing immigration from a metacommunity. The mesocosms were maintained under either constant or variable nutrient environments. Population, community, and ecosystem data were collected for five months. We found that zooplankton population and community stability is enhanced in species‐rich communities in both constant and variable environments. Species richness increased primarily through the addition of species with low abundance. The communities that were connected to a metacommunity via immigration were the most diverse and the most stable, indicating the importance of both metacommunity dynamics and rare species for stability. We found little evidence for selection effects or overyielding as stabilizing forces. We did find support for asynchronous dynamics and statistical averaging, both of which predict destabilizing effects at the population level. We also found support for weak interactions, which predicts that both populations and communities will become more stable as richness increases. In order to understand the effects of biodiversity loss on stability, we will need to understand when different stabilizing mechanisms tend to operate but also how multiple mechanisms interact.
Delayed life history effects, multilevel selection, and evolutionary trade‐offs in the California tiger salamander
Authors: Searcy Christopher A. , Gray Levi N. , Trenham Peter C. , Shaffer H. Bradley
Published: January 2014

Delayed life history effects (DLHEs) occur when fitness in one life stage affects fitness in subsequent life stages. Given their biphasic life cycle, pond‐breeding amphibians provide a natural system for studying DLHEs, although these effects are not restricted to species with biphasic life histories. In this study, we used multiple mark–recapture techniques enabled by a large trapping array to monitor components of fitness and resulting DLHEs in a population of the endangered California tiger salamander (Ambystoma californiense). We found that DLHEs are prominent across all life stage transitions and that there is variation in whether selection acts primarily at the individual or cohort level. We also demonstrated that there is more than an order of magnitude variation in mean cohort fitness, providing tremendous variation for DLHEs to act upon. We documented an evolutionary trade‐off between mass at emergence and date of emergence, which may play a role in maintaining the variation in mass (fitness) at emergence. A literature review revealed that such high levels of intercohort variation occur in many other pond‐breeding amphibians, and that appropriately documenting the magnitude of intercohort variation requires long‐term studies (roughly two population turnovers). Given the profound effect that DLHEs can have on population dynamics, quantifying intercohort variation in mean fitness and the level(s) at which selection acts will be very important for developing accurate models of population dynamics. In general, when developing models of population dynamics, more attention should be paid to variation in mean fitness and not just variation in total numbers.
Interactive effects of grazing, drought, and fire on grassland plant communities in North America and South Africa
Authors: Koerner Sally E. , Collins Scott L.
Published: January 2014

Grazing, fire, and climate shape mesic grassland communities. With global change altering all three factors, understanding how grasslands respond to changes in these combined drivers may aid in projecting future changes in grassland ecosystems. We manipulated rainfall and simulated grazing (clipping) in two long‐term fire experiments in mesic grasslands in North America (NA) and South Africa (SA). Despite their common drivers, grasslands in NA and SA differ in evolutionary history. Therefore, we expected community structure and production in NA and SA to respond differently to fire, grazing, and drought. Specifically, we hypothesized that NA plant community composition and production would be more responsive than the SA plant communities to changes in the drivers and their interactions, and that despite this expected stability of SA grasslands, drought would be the dominant factor controlling production, but grazing would play the primary role in determining community composition at both sites. Contrary to our hypothesis, NA and SA grasslands generally responded similarly to grazing, drought, and fire. Grazing increased diversity, decreased grass cover and production, and decreased belowground biomass at both sites. Drought alone minimally impacted plant community structure, and we saw similar treatment interactions at the two sites. Drought was not the primary driver of grassland productivity, but instead drought effects were similar to or less than grazing and fire. Even though these grasslands differed in evolutionary history, they responded similarly to our fire, grazing, and climate manipulations. Overall, we found community and ecosystem convergence in NA and SA grasslands. Grazing and fire are as important as climate in controlling mesic grassland ecosystems on both continents.
Are exotic herbivores better competitors? A meta‐analysis
Authors: Radville Laura , Gonda-King Liahna , Gómez Sara , Kaplan Ian , Preisser Evan L.
Published: January 2014

Competition plays an important role in structuring the community dynamics of phytophagous insects. As the number and impact of biological invasions increase, it has become increasingly important to determine whether competitive differences exist between native and exotic insects. We conducted a meta‐analysis to test the hypothesis that native/exotic status affects the outcome of herbivore competition. Specifically, we used data from 160 published studies to assess plant‐mediated competition in phytophagous insects. For each pair of competing herbivores, we determined the native range and coevolutionary history of each herbivore and host plant. Plant‐mediated competition occurred frequently, but neither native nor exotic insects were consistently better competitors. Spatial separation reduced competition in native insects but showed little effect on exotics. Temporal separation negatively impacted native insects but did not affect competition in exotics. Insects that coevolved with their host plant were more affected by interspecific competition than herbivores that lacked a coevolutionary history. Insects that have not coevolved with their host plant may be at a competitive advantage if they overcome plant defenses. As native/exotic status does not consistently predict outcomes of competitive interactions, plant–insect coevolutionary history should be considered in studies of competition.
Transient habitats limit development time for periodical cicadas
Authors: Karban Richard
Published: January 2014

Periodical cicadas (Magicicada spp.) mature in 13 or 17 years, the longest development times for any non‐diapausing insects. Selection may favor prolonged development since nymphs experience little mortality and individuals taking 17 years have been shown to have greater fecundity than those taking 13 years. Why don't periodical cicadas take even longer to develop? Nymphs feed on root xylem fluid and move little. Ovipositing females prefer fast‐growing trees at forest edges. I hypothesized that (1) adults emerging at edges would be heavier than those from forest interiors and (2) habitat changes could limit development time. I collected newly eclosed females that had neither fed as adults nor moved from their site of development. For M. septendecim, females from edges were 4.9% heavier than those from the interior. I assumed that emergence density indicated habitat quality and measured density at eight sites in 1979, 1996, and 2013. Over three generations, variation in densities was great; densities at two sites crashed, and at one site they exploded to 579/m2. Habitat transience may limit development time because only adults can reassess habitats and reposition offspring. In conclusion, cicadas are affected by habitat characteristics, habitats change over 17 years, and cicadas may emerge, mate, and redistribute their offspring to track habitat dynamics.