bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial Appraisal of the Impacts of Drought on Agricultural Patterns in Karachi
Authors: Lubna Ghazal  , Syed Jamil H. Kazmi  , Sheeba Afsar
Published: May 2013

This paper is aimed at studying the spatial changes in agricultural patterns practiced in the suburbs of Karachi, which is the most densely populated city of Pakistan with high food demands of the inhabitants. This study deals mainly with Physical factors primarily climatic indicators to observe and analyze the changes in the pattern of agricultural production and the types of crops in last 20-30 years. Variability of climate when coupled with anthropogenic factors play important role in the acceleration of problems for farmers. Trends of associated agricultural output observed in different years of high and low rainfall. This study has successfully demonstrated inquisitive approach by using published secondary data from governmental sources and ground verification in recent times. Temporal variation in biomass, was found dependent upon pattern of rainfall and temperature etc. Study reveals that there are clear signs of desertification and drought in the study area.
Seasonal Variations in Wave Energy and the Changing Beach Characteristics: A Case Study of Beaches of Karachi
Authors: Syed Shahid Ali  , Sheeba Afsar
Published: May 2013

The study of beach characteristics is generally described in terms of the relationship of wind velocity, wave energy, beach profile and grain size variation of the beach sediments. Most of the coastal research is concerned with investigating the behavior of water and sediments along the shoreline; these being the processes responsible for the formation of coastal land forms. The amount of erosion and depositional activities along a shoreline depends on the quantity of energy in the waves which are also responsible for bringing changes in the beach profile and hence beaches are classified on the bases of the impacts of these processes which are presented here in this paper.
Comparison of Outlier Detection Methods in Crossover Design Bioequivalence Studies
Authors: Rasheed  , T. Ahmad  , J.S. Siddiqi
Published: May 2013

The significance of bioequivalence (BE) studies is rising due to large scale production and utilization of generic products all over the world. The correct identification of outlying data in BE studies is substantial for deciding two products either bioequivalence or bioinequivalent. For the detection of outliers in BE studies with the crossover designs different methods have been suggested in the literature. In the present work, we compared three outlier detection tests; (i) the Likelihood distance (LD) test (ii) the estimated distance (ED) test and the principal component analysis (PCA) test. In this work, the PCA test has been first time compared with the LD and ED test. For the purpose of comparison, we used two-way and three-way BE crossover data sets on linear and logarithmic scales. During the course of work it was found interesting and note-worthy that the performances of the ED and PCA tests in the sense of outlier detection are better than the LD test and this performance persists even for the log-transformed data. The results of our simulation study also indicated that the performance of the ED test for outliers’ identification is better than the other two tests.
Butanol alcoholysis reaction of polyethylene terephthalate using acidic ionic liquid as catalyst
Authors: Liu Shiwei , Wang Zhiping , Li Lu , Yu Shitao , Xie Congxia , Liu Fusheng
Published: May 2013

The alcoholysis reaction of polyethylene terephthalate (PET) and n‐butanol to produce dibutyl terephthalate (DBTP) and ethylene glycol (EG) was investigated in the presence of a Brönsted–Lewis acidic ionic liquid (IL). It was found that a synergetic effect of Brönsted and Lewis acid sites enhanced the IL catalytic performance, and (3‐sulfonic acid) propyltriethylammonium chlorozincinate [HO3S‐(CH2)3‐NEt3]Cl‐ZnCl2 (molar fraction of ZnCl2 (x) was 0.67) was a good catalyst for the reaction. The conversion of PET was 100%, and the yields of DBTP and EG were 95.3% and 95.7% at 205°C for 8 h, respectively. The reusability of IL was good and after it was used seven times, PET conversion and the yields of DBTP and EG did not significantly decrease. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1840–1844, 2013
Effects of shear stress and subcritical water on devulcanization of styrene–butadiene rubber based ground tire rubber in a twin‐screw extruder
Authors: Wang Xiaojun , Shi Changping , Zhang Ling , Zhang Yuncan
Published: May 2013

The devulcanization reaction of styrene–butadiene rubber (SBR) based ground tire rubber (GTR) in GTR/ethylene–propylene–diene monomer rubber (EPDM) blend was investigated through a compound‐induced reaction by increasing screw rotation speed and being in the presence of subcritical water. The effects of temperature, pressure, screw rotation speed, or promoting agents on the gel content, Mooney viscosity, and Fourier transform infrared spectra of the sol of the devulcanized blends (devulcanized ground tire rubber (DGTR)/EPDM) were measured, and the mechanical properties and microstructures of the revulcanized blend ((DGTR/EPDM)/SBR) were characterized. The results show that subcritical water as a swelling agent and reaction medium promotes the devulcanization reaction, increases the selectivity of the crosslink breakage, keeps the extrusion material from oxidative degradation, reduces the gel particle size of the devulcanized blends, and significantly improves the mechanical properties of the revulcanized SBR/(DGTR/EPDM) blends. In subcritical water, the suitable promoting agents (alkylphenol polysulfide 450, hydrogen peroxide H2O2, or 450/H2O2) accelerate the devulcanization reaction, keep the double bond content, and lead to further decrease of the gel content and Mooney viscosity of the devulcanized blends and further increase of the mechanical properties of the revulcanized SBR/(DGTR/EPDM) blends. Especially the compound promoting agent (450/H2O2) improves the selectivity of the crosslink breakage in devulcanization of SBR‐based GTR. When 450/H2O2 is added as a compound promoting agent at the best reaction condition in subcritical water (200°C, 1.6 MPa and 1000 rpm), the tensile strength and elongation at break of the revulcanized SBR/(DGTR/EPDM) blends reach to 85.4% and 201% of vulcanized SBR (24.0 MPa, 356%), respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1845–1854, 2013
Evaluation of 1‐ethyl‐3‐methylimidazolium acetate based ionic liquid systems as a suitable solvent for collagen
Authors: Hu Yang , Liu Lan , Dan Weihua , Dan Nianhua , Gu Zhipeng
Published: May 2013

Collagen, a prominent biopolymer, which is famous for its excellent biological activity, has been used extensively for tissue engineering applications. In this study, a novel solvent system for collagen was developed with an ionic liquid, 1‐ethyl‐3‐methylimidazolium acetate ([EMIM][Ac]), solvent system. A series of sodium salts were introduced into this solvent system to enhance collagen's dissolution procedure. The results show that the solubility of collagen was significantly influenced by the temperature and sodium salts. The solubility reached up to approximately 11% in the [EMIM][Ac]/Na2HPO4 system at 45°C. However, the structure of the regenerated collagen (Col‐regenerated) may have been damaged. Hence, we focused on the structural integrity of the collagen regenerated from the [EMIM][Ac] solvent system by the methods of sodium dodecyl sulfate–polyacrylamide gel electrophoresis, Fourier transform infrared spectroscopy, ultrasensitive differential scanning calorimetry, atomic force microscopy, X‐ray diffraction, and circular dichroism because its signature biological and physicochemical properties were based on its structural integrity. Meanwhile, a possible dissolution mechanism was proposed. The results show that the triple‐helical structure of collagen regenerated from the [EMIM][Ac] solvent system below 35°C was retained to a large extent. The biocompatibility of Col‐regenerated was first characterized with a fibroblast adhesion and proliferation model. It showed that the Col‐regenerated had almost the same good biological activity as nature collagen, and this indicated the potential application of [EMIM][Ac] in tissue engineering. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2245–2256, 2013
How does SHIP1/2 balance PtdIns(3,4)P2 and does it signal independently of its phosphatase activity?
Authors: Xie Jingwei , Erneux Christophe , Pirson Isabelle
Published: May 2013

The number of cellular events identified as being directly or indirectly modulated by phosphoinositides dramatically increased in the recent years. Part of the complexity results from the fact that the seven phosphoinositides play second messenger functions in many different areas of growth factors and insulin signaling, cytoskeletal organization, membrane dynamics, trafficking, or nuclear signaling. PtdIns(3,4)P2 is commonly reported as a product of the SH2 domain‐containing inositol 5‐phosphatases 1/2 (SHIP1 and SHIP2) that dephosphorylate PtdIns(3,4,5)P3 at the 5‐position. Here we discuss recent interest in PtdIns(3,4)P2 signaling highlighting its involvement in key cellular mechanisms such as cell adhesion, migration, and cytoskeletal regulation. We question and discuss the involvement of SHIP2 either as a PI 5‐phosphatase or as a scaffold protein in insulin signaling, cytoskeletal dynamics, and endocytosis of growth factor receptors.
Quantification of conjugated metabolites of drugs in biological matrices after the hydrolysis with β‐glucuronidase and sufatase: a review of bio‐analytical methods
Authors: Ding Yue , Peng Ming , Zhang Tong , Tao Jian‐Sheng , Cai Zhen‐Zhen , Zhang Yong
Published: May 2013

Glucuronidation and sulfation represent two major pathways in phase II drug metabolism in humans and other mammalian species. The great majority of drugs, for example, polyphenols, flavonoids and anthraquinones, could be transformed into sulfated and glucuronidated conjugates simultaneously and extensively in vivo. The pharmacological activities of drug conjugations are normally decreased compared with those of their free forms. However, some drug conjugates may either bear biological activities themselves or serve as excellent sources of biologically active compounds. As the bioactivities of drugs are thought to be relevant to the kinetics of their conjugates, it is essential to study the pharmacokinetic behaviors of the conjugates in more detail. Unfortunately, the free forms of drugs cannot be detected directly in most cases if their glucuronides and sulfates are the predominant forms in biological samples. Nevertheless, an initial enzymatic hydrolysis step using β‐glucuronidase and/or sulfatase is usually performed to convert the glucuronidated and/or sulfated conjugates to their free forms prior to the extraction, purification and other subsequent analysis steps in the literature. This review provides fundamental information on drug metabolism pathways, the bio‐analytical strategies for the quantification of various drug conjugates, and the applications of the analytical methods to pharmacokinetic studies. Copyright © 2013 John Wiley & Sons, Ltd.
Anatomical relationship and positions of the lumbar and sacral segments of the spinal cord according to the vertebral bodies and the spinal roots
Authors: Canbay Suat , Gürer Bora , Bozkurt Melih , Comert Ayhan , Izci Yusuf , Başkaya Mustafa K.
Published: May 2013

Segments of the spinal cord generally do not correspond to the respective vertebral level and there are many anatomical variations in terms of the segment and the level of vertebra. The aim of this study is to investigate the variations and levels of lumbar and sacral spinal cord segments with reference to the axilla of the T11, T12, and L1 spinal nerve roots and adjacent vertebrae. Morphometric measurements were made on 16 formalin fixed adult cadaveric spinal cords. We observed termination of the spinal cord between the axilla of the L1 and L2 spinal nerve roots in 15 specimens (93.8%). In all cadavers the emergence of the T11, T12, and the L1 spinal nerve roots was at the level of the lower one‐third of the same vertebral body. In 15 specimens (93.8%), the beginning of the lumbar spinal cord segment was found to be above the T11 spinal nerve root axilla and corresponded to the upper one‐third of the T11 vertebral body. The beginning of the sacral spinal cord segment occurred above the L1 spinal nerve root axilla and corresponded to the upper one‐third of the L1 vertebral body. The results of this study showed that when the conus medullaris is located at the L1–L2 level, the beginning of the lumbar spinal cord segment always corresponds to the body of T11 vertebra. This study provides detailed information about the correspondence of the spinal cord segments with reference to the axilla of the spinal nerve roots. Clin. Anat. 27:227–233, 2014. © 2013 Wiley Periodicals, Inc.
Chiral Hexa‐ and Nonamethylene‐Bridged Bis(L‐Leu‐oxalamide) Gelators: The First Oxalamide Gels Containing Aggregates with a Chiral Morphology
Authors: Vujičić Nataša Šijaković , Glasovac Zoran , Zweep Niek , van Esch Jan H. , Vinković Marijana , Popović Jasminka , Žinić Mladen
Published: May 2013

Chiral amino acid‐ and amino alcohol‐oxalamides are well‐known as versatile and efficient gelators of various lipophilic and polar organic solvents and water. To further explore the capacity of the amino acid/oxalamide structural fragment as a gelation‐generating motif, the dioxalamide dimethyl esters 16Me and 19Me, and dicarboxylic acid 26OH/29OH derivatives containing flexible methylene bridges with odd (9; n=7) and even (6; n=4) numbers of methylene groups were prepared. Their self‐assembly motifs and gelation properties were studied by using a number of methods (FTIR, 1H NMR spectroscopy, CD, TEM, DSC, XRPD, molecular modeling, MMFF94, and DFT). In contrast to the previously studied chiral bis(amino acid or amino alcohol) oxalamide gelators, in which no chiral morphology was ever observed in the gels, the conformationally more flexible 16Me, 19Me, 26OH, and 29OH provide gelators that are capable of forming diverse aggregates of achiral and chiral morphologies, such as helical fibers, twisted tapes, nanotubules, straight fibers, and tapes, in some cases coexisting in the same gel sample. It is shown that the differential scanning calorimetry (DSC)‐determined gelation enthalpies could not be correlated with gelator and solvent clogP values. Spectroscopic results show that intermolecular hydrogen‐bonding between the oxalamide units provides the major and self‐assembly directing intermolecular interaction in the aggregates. Molecular modeling studies reveal that molecular flexibility of gelators due to the presence of the polymethylene bridges gives three conformations (zz, p1, and p2) close in energy, which could form oxalamide hydrogen‐bonded layers. The aggregates of the p1 and p2 conformations tend to twist due to steric repulsion between neighboring iBu groups at chiral centers. The X‐ray powder diffraction (XRPD) results of 16Me and 19Me xerogels prove the formation of p1 and p2 gel aggregates, respectively. The latter results explain the formation of gel aggregates with chiral morphology and also the simultaneous presence of aggregates of diverse morphology in the same gel system.
Development of myenteric cholinergic neurons in ChAT‐Cre;R26R‐YFP mice
Authors: Hao Marlene M. , Bornstein Joel C. , Young Heather M.
Published: May 2013

Cholinergic neurons are the major excitatory neurons of the enteric nervous system (ENS), and include intrinsic sensory neurons, interneurons, and excitatory motor neurons. Cholinergic neurons have been detected in the embryonic ENS; however, the development of these neurons has been difficult to study as they are difficult to detect prior to birth using conventional immunohistochemistry. In this study we used ChAT‐Cre;R26R‐YFP mice to examine the development of cholinergic neurons in the gut of embryonic and postnatal mice. Cholinergic (YFP+) neurons were first detected at embryonic day (E)11.5, and the proportion of cholinergic neurons gradually increased during pre‐ and postnatal development. At birth, myenteric cholinergic neurons comprised less than half of their adult proportions in the small intestine (25% of myenteric neurons were YFP+ at P0 compared to 62% in adults). The earliest cholinergic neurons appear to mainly project anally. Projections into the presumptive circular muscle were first observed at E14.5. A subpopulation of cholinergic neurons coexpress calbindin through embryonic and postnatal development, but only a small proportion coexpressed neuronal nitric oxide synthase. Our study shows that cholinergic neurons in the ENS develop over a protracted period of time. J. Comp. Neurol. 521:3358–3370, 2013. © 2013 Wiley Periodicals, Inc.
Incompleteness as a Link between Obsessive–Compulsive Personality Traits and Specific Symptom Dimensions of Obsessive–Compulsive Disorder
Authors: Ecker Willi , Kupfer Jochen , Gönner Sascha
Published: May 2013

This paper examines the contribution of incompleteness/‘not just right experiences’ (NJREs) to an understanding of the relationship between obsessive–compulsive disorder (OCD) and obsessive–compulsive personality traits (OCPTs). It investigates the association of specific OCD symptom dimensions with OCPTs, conceptualized as continuous phenomena that are also observable below the diagnostic threshold. As empirical findings and clinical observation suggest that incompleteness feelings/NJREs may play a significant affective and motivational role for certain OCD subtypes, but also for patients with accentuated OCPTs, we hypothesized that OCPTs are selectively linked with incompleteness‐associated OCD symptom dimensions (ordering, checking, hoarding and counting). Moreover, we assumed that this selective relationship cannot be demonstrated any more after statistical control of incompleteness, whereas it is preserved after statistical control of anxiety, depression, pathological worry and harm avoidance. Results from a study with a large clinical sample (n = 185) partially support these hypotheses and suggest that NJREs may be an important connecting link between specific OCD symptom dimensions, in particular ordering and checking, and accentuated OCPTs. Copyright © 2013 John Wiley & Sons, Ltd.

Key Practitioner Message

Obsessive–compulsive personality traits (OCPTs) are positively related to obsessive–compulsive disorder symptom dimensions (ordering, checking, hoarding and counting) hypothesized or found to be associated with incompleteness/‘not just right experiences’ (NJREs), but not to washing and obsessions.

This positive relationship, which is strongest for ordering and checking, is eliminated when NJREs are statistically controlled.

Ordering, checking and accentuated OCPTs may share NJREs as a common affective‐motivational underpinning.

Dysfunctional behaviour patterns of people with accentuated OCPTs or obsessive–compulsive personality disorder (OCPD) may be viewed as efforts to avoid or reduce subjectively intolerable NJREs.

On the basis of such a conceptualization of OCPD as an emotional disorder, a novel treatment approach for OCPD focusing on habituation to NJREs could be developed.
The First Example of the Two‐Electron Reduction of a Phosphaalkyne – Synthesis and Structural Characterisation of the Diuranium(IV) Pentalene Complex [(U{η5‐C5Me5}{η8‐C8H4(SiiPr3‐1,4)2})2(μ‐η2:η1‐tBuCP)]
Authors: Tsoureas Nikolaos , Kilpatrick Alexander F. R. , Summerscales Owen T. , Nixon John F. , Cloke F. Geoffrey N. , Hitchcock Peter B
Published: May 2013

The facile two‐electron reduction of the phosphaalkyne tBuC≡P by the UIII cyclopentadienyl–pentalene mixed‐sandwich complex [U(η5‐C5Me5){η8‐C8H4(SiiPr3)2}] is reported. A single‐crystal X‐ray structural analysis of the diuranium(IV) product [(U{η5‐C5Me5}{η8‐C8H4(SiiPr3)2})2(μ‐tBuCP)] shows that it contains a slightly unsymmetrical, bridging μ‐η2:η1‐ligated phosphaalkene dianion.
Synthesis and Structural Studies of α/β‐Peptides Derived from Fused Furano‐pyran­ β‐Amino Acid and L‐Ala
Authors: Sharma Gangavaram V. M. , Sridhar Tailor , Reddy Pothula Purushotham , Kunwar Ajit C.
Published: May 2013

New fused cis‐ and trans‐furano‐pyran β‐amino acids were synthesized. The cis‐monomer was utilized for the synthesis of α/β‐peptides (tetra‐, penta‐, hexa‐ and hepta‐mers), to understand its impact on helix formation. Conformational analysis of the peptides with a “β‐α‐β” sequence at the C‐terminus showed the presence of a left‐handed 9/11‐helix in which the nine‐membered H‐bond motif is found to be weak and contributes only a small amount of electrostatic interaction to helix stabilization. Peptides with an “α‐β‐α” sequence at the C‐terminus revealed the presence of a left‐handed 9/11‐helix involving the central residues and display a clear 12‐membered turn at the C‐terminus. In both the cases, the 9/11‐helix was stabilized by a seven‐membered H‐bond at the N‐terminus.
Chemoenzymatic Asymmetric Synthesis of Serotonin Receptor Agonist (R)‐Frovatriptan
Authors: Busto Eduardo , Martínez‐Montero Lía , Gotor Vicente , Gotor‐Fernández Vicente
Published: May 2013

A simple chemoenzymatic asymmetric route has been developed for the production of antimigraine agent (R)‐Frovatriptan. Lipases and oxidoreductases have been identified as ideal biocatalysts for the production of enantiopure adequate synthetic intermediates under safe and environmentally friendly conditions. (S)‐3‐Hydroxy‐2,3,4,9‐tetrahydro‐1H‐carbazole‐6‐carbonitrile, an optimal building block for the synthesis of the drug, has been efficiently prepared through Candida antarctica lipase type B catalyzed acylation of its corresponding racemic mixture or alcohol dehydrogenase A mediated bioreduction of the corresponding ketone. The inversion of the chiral center has been identified as a key step, optimizing the process to avoid partial racemization. Finally, amine functionalization and nitrile hydrolysis have allowed the production of (R)‐Frovatriptan in enantiomerically pure form.
A Detailed Study of the (Electro)chemical Behavior of Bis(trifluoromethanesulfonyl)imide Based Ionic Liquids at Different Purification Steps
Authors: Merli Daniele , Protti Stefano , Petracca Paola , Fagnoni Maurizio , Profumo Antonella
Published: May 2013

A systematic investigation of the major impurities content as well as of their effect on the electrochemical behavior of synthesized N‐butyl‐N‐methylpyrrolidinium (Py1.4), N‐(2‐methoxyethyl)‐N‐methylpyrrolidinium (Py1.102) and 1‐butyl‐3‐methylimidazolium (bmim) bis(trifluoromethanesulfonyl)imide has been carried out and the efficacy of an optimized multistep purification protocol for obtaining ILs suitable for electrochemical applications has been verified.
Code‐expanded radio access protocol for machine‐to‐machine communications
Authors: Thomsen Henning , Pratas Nuno K. , Stefanović Čedomir , Popovski Petar
Published: May 2013

The random access methods used for support of machine‐to‐machine, also referred to as Machine‐Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated by the random access method employed in LTE, which significantly increases the amount of contention resources without increasing the system resources, such as contention subframes and preambles. This is accomplished by a logical, rather than physical, extension of the access method in which the available system resources are interpreted in a novel manner. Specifically, in the proposed scheme, users perform random access by transmitting orthogonal preambles in multiple random access subframes, in this way creating access codewords that are used for contention. We show that, for the same number of random access subframes and orthogonal preambles, the amount of available contention resources is drastically increased, enabling the massive support of Machine‐Type Communication users that is beyond the reach of current systems. Copyright © 2013 John Wiley & Sons, Ltd.
Structural and petrophysical characterization of the upper basement crustal section at ODP/IODP Site 1256 (East Pacific Ocean)
Authors: Fontana Emanuele , Tartarotti Paola
Published: May 2013

New ocean crust is constantly being formed from mid‐ocean ridge axis. Voluminous flows of lava are emplaced also away from the ridge axis, adding off‐axis crustal layers to the crustal pile. Research on deep sea is of great importance to better understand the mechanisms and the nature of the crust forming and evolution. In this work, we decipher the first stages of the postmagmatic evolution of an intact volcanic section from the upper oceanic crust at ocean drilling program/integrated ocean drilling program (ODP/IODP) Site 1256 (Eastern Pacific Ocean). Using for the first time an innovative core‐log integration technique to match direct (core‐related) and indirect (borehole‐related) data by depth shifting and reorienting individual core pieces recovered by drilling, we are able to identify the clusterization of structures and physical properties within distinct downdeep “strong” and “weak” lava zones, reflecting the cooling and tectonic evolution of lavas rather than lithological variations. We define the evolution of the structural zones that typically affect lava flows: colonnades and entablature zones, studying an off‐axis lava flow encountered in present‐day upper ocean crust. For the same off‐axis flow, we are also able to suggest the lava flow direction (NW‐SE) and its relationships with the paleoridge axis. Despite the environmental difficulties in the study of the subseafloor under deep water and using only one‐dimensional data deriving from ocean drilling, this work shows how an array of diverse data can be integrated into a coherent interpretation of lava flow history obtaining detailed information on the mechanism of submarine lava emplacement and flow.
ESR signal intensity and crystallinity of quartz from Gobi and sandy deserts in East Asia and implication for tracing Asian dust provenance
Authors: Sun Youbin , Chen Hongyun , Tada Ryuji , Weiss Dominik , Lin Min , Toyoda Shin , Yan Yan , Isozaki Yuko
Published: May 2013

Electron spin resonance (ESR) signal intensity and crystallinity index (CI) of fine‐ (<16 µm) and coarse‐grained (>16 µm) quartz were measured in surface samples from the Taklimakan desert in western China, the Badain Juran, Tengger and Mu Us deserts in northern China, and the Gobi desert in southern Mongolia to evaluate whether these geophysical parameters can serve as reliable provenance tracers of Asian dust. The results indicate that spatial variability of both ESR signal intensity and CI is evident within the Taklimakan deserts and the Mongolian Gobi, but less significant in the three deserts of northern China. Coarse‐grained quartz from the Mongolian Gobi and northern China deserts can be differentiated from the Taklimakan desert using the ESR signal intensity. Fine‐grained quartz originating from three major Asian dust sources, i.e., the Gobi‐sandy deserts in western China, northern China and southern Mongolia, can be distinguished effectively using the combination of ESR and CI signals. Our results suggest that ESR signal intensity and CI can discriminate the sources of fine‐grained quartz better than coarse‐grained quartz, providing an effective approach to trace the provenance of fine‐grained dust deposition on the land and in the ocean.
THE EFFECTS OF HEALTH STATUS AND HEALTH SHOCKS ON HOURS WORKED
Authors: Cai Lixin , Mavromaras Kostas , Oguzoglu Umut
Published: May 2013

We investigate the impact of health on working hours. This is in recognition of the fact that leaving the labour market because of persistently low levels of health status, or because of new health shocks, is only one of the possible responses open to employees. We use the first six waves of the Household, Income and Labour Dynamics in Australia (HILDA) Survey to estimate the joint effect of health status and health shocks on working hours. To account for zero working hours, we use a dynamic random effects Tobit model of working hours. We follow Heckman (1981) and approximate the unknown initial conditions with a static equation that utilises information from the first wave of the data. Predicted individual health status is used to ameliorate the possible effects of measurement error and endogeneity. We conclude that overall, lower health status results in fewer working hours and that when they occur, health shocks lead to further reductions in working hours. Estimation results show that the model performs well in separating the time‐persistent effect of health status and the potentially more transient health shocks on working hours. Copyright © 2013 John Wiley & Sons, Ltd.
Associations of Mother–Child Reminiscing about Negative Past Events, Coping, and Self‐Concept in Early Childhood
Authors: Goodvin Rebecca , Romdall Lisa
Published: May 2013

Parent–child reminiscing conversations in early childhood have received theoretical attention as a forum for children's self‐concept development, but this has been little addressed in empirical work. This study examines associations between emotion reminiscing and children's self‐concepts and, building from the reminiscing and personality development literatures, also explores the role of children's coping. Sixty 4‐ and 5‐year‐old children and their mothers completed reminiscing conversations about events in which the child had experienced negative emotion, children completed an age‐appropriate assessment of their self‐concept, and mothers and teachers reported on children's coping strategies. Children's self‐perceived timidity was associated with their explanations for negative emotions during reminiscing. Children's self‐perceived negative affect was associated with fewer emotion resolutions during reminiscing, and with distinctive patterns of coping. Both reminiscing and coping made unique contributions to children's self‐concepts, and findings also suggest that coping may in some contexts indirectly connect reminiscing with self‐concept. These findings suggest that reminiscing conversations both reflect children's characteristics and provide a context for learning about their characteristics, along with strategies for emotion management. Copyright © 2013 John Wiley & Sons, Ltd.
Development of microbial resistant thermosensitive Ag nanocomposite (gelatin) hydrogels via green process
Authors: Manjula Bandla , Varaprasad Kokkarachedu , Sadiku Rotimi , Ramam Koduri , Reddy G. Venkata Subba , Raju Konduru Mohana
Published: May 2013

In this investigation, an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using biodegradable gelatin as a stabilizing agent is reported. Here, we prepared thermosensitive silver nanocomposite hydrogels composed of gelatin and N‐isopropylacrylamide. In this green process AgNPs were formed from Ag+ ions and reduced with leaf [Azadirachta indica (neem leaf)] extracts, resulting in a hydrogel network. The Ag0 nanoparticles affect the hydrogel strength and improved the biological activity (inactivation effect of bacteria) of the biodegradable hydrogels. The resulted hydrogel structure, morphology, thermal, swelling behavior, degradation, and antibacterial properties were systematically investigated. The biodegradable thermosensitive silver nanocomposite hydrogels developed were tested for antibacterial activities. The results indicate that these biodegradable silver nanocomposite hydrogels are suitable potential candidates for antibacterial applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 928–934, 2014.
Comparison of cell‐loading methods in hydrogel systems
Authors: Ma Jinling , Yang Fang , Both Sanne K. , Kersten‐Niessen Monique , Bongio Matilde , Pan Juli , Cui Fu‐Zhai , Kasper F. Kurtis , Mikos Antonios G. , Jansen John A. , van den Beucken Jeroen J. J. P.
Published: May 2013

Bone regenerative medicine, based on the combined use of cells and scaffolds, represents a promising strategy in bone regeneration. Hydrogels have attracted huge interests for application as a scaffold for minimally invasive surgery. Collagen and oligo(poly(ethylene glycol)fumarate) (OPF) hydrogels are the representatives of two main categories of hydrogels, that is, natural‐ and synthetic‐based hydrogels. With these the optimal cell‐loading (i.e., cell distribution inside the hydrogels) method was assessed. The cell behavior of both bone marrow‐ and adipose tissue‐derived mesenchymal stem cells (BM‐ and AT‐MSCs) in three loading methods, which are dispersed (i.e., homogeneous cell encapsulation, D), sandwich (i.e., cells located in between two hydrogel layers, S), and spheroid (i.e., cell pellets encapsulation, Sp) loading in two hydrogel systems (i.e., collagen and OPF), was compared. The results suggested that the cell behavior was influenced by the hydrogel type, meaning cells cultured in collagen hydrogels had higher proliferation and osteogenic differentiation capacity than in OPF hydrogels. In addition, AT‐MSCs exhibited higher proliferation and osteogenic properties compared to BM‐MSCs. However, no difference was observed for mineralization among the three loading methods, which did not approve the hypothesis that S and Sp loading would increase osteogenic capacity compared to D loading. In conclusion, D and Sp loading represents two promising cell loading methods for injectable bone substitute materials that allow application of minimally invasive surgery for cell‐based regenerative treatment. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 935–946, 2014.
Comparison of three hydroxyapatite/β‐tricalcium phosphate/collagen ceramic scaffolds: Anin vivostudy
Authors: Maté‐Sánchez de Val José Eduardo , Mazón Patricia , Calvo‐Guirado José Luis , Ruiz Rafael Arcesio Delgado , Ramírez Fernández María Piedad , Negri Bruno , Abboud Marcus , De Aza Piedad N.
Published: May 2013

Calcium–phosphate ceramics, which have a composition similar to bone mineral, represent a potentially interesting synthetic bone graft substitute. In the present study, three porous hydroxyapatite (HA)/β‐tricalcium phosphate (β‐TCP)/collagen ceramic scaffolds were developed, characterized, and tested for their bone repairing capacity and osteoinductive potential in a New Zealand Rabbit model. The ratio of the ceramic components HA/‐TCP/collagen varied from 40/30/30 to 50/20/30 and 60/20/20 (in wt %), respectively. None of the ceramic scaffolds succeeded in completely bridging the 6 mm calvarian defect with new bone after 60 days implantation. 60/20/20 ceramic scaffolds showed significantly more bone formation in the pores and in the periphery of the graft than the other two materials. Histomorphometric analysis revealed that the 40/30/30 scaffold produced best bone‐to‐implant contact (67.23 ± 0.34% with higher quality, closer contact) in comparison with 50/20/30 (54.87 ± 0.32%), and 60/20/20 (48.53 ± 0.31%). Both physicochemical and structural properties of the ceramic composites affected theirin vivobehavior, either dependently or independently, emphasizing the importance of assessing bone repair parameters individually. The scaffolds may offer clinical applications in reconstructive surgery for treating bone pathologies. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1037–1046, 2014.
In vitro biological and mechanical evaluation of various scaffold materials for myocardial tissue engineering
Authors: Herrmann Florian E. M. , Lehner Anja , Hollweck Trixi , Haas Ulrike , Fano Cornelia , Fehrenbach David , Kozlik‐Feldmann Rainer , Wintermantel Erich , Eissner Gunther , Hagl Christian , Akra Bassil
Published: May 2013

A cardiac patch is a construct devised in regenerative medicine to replace necrotic heart tissue after myocardial infarctions. The cardiac patch consists of a scaffold seeded with stem cells. To identify the best scaffold for cardiac patch construction we compared polyurethane, Collagen Cell Carriers, ePTFE, and ePTFE SSP1‐RGD regarding their receptiveness to seeding with mesenchymal stem cells isolated from umbilical cord tissue. Seeding was tested at an array of cell seeding densities. The bioartificial patches were cultured for up to 35 days and evaluated by scanning electron microscopy, microscopy of histological stains, fluorescence microscopy, and mitochondrial assays. Polyurethane was the only biomaterial which resulted in an organized multilayer (seeding density: 0.750 × 106 cells/cm2). Cultured over 35 days at this seeding density the mitochondrial activity of the cells on polyurethane patches continually increased. There was no decrease in the E Modulus of polyurethane once seeded with cells. Seeding of CCC could only be realized at a low seeding density and both ePTFE and ePTFE SSP1‐RGD were found to be unreceptive to seeding. Of the tested scaffolds polyurethane thus crystallized as the most appropriate for seeding with mesenchymal stem cells in the framework of myocardial tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 958–966, 2014.
Sustained delivery of bioactive TGF‐β1 from self‐assembling peptide hydrogels induces chondrogenesis of encapsulated bone marrow stromal cells
Authors: Kopesky Paul W. , Byun Sangwon , Vanderploeg Eric J. , Kisiday John D. , Frisbie David D. , Grodzinsky Alan J.
Published: May 2013

Tissue engineering strategies for cartilage defect repair require technology for local targeted delivery of chondrogenic and anti‐inflammatory factors. The objective of this study was to determine the release kinetics of transforming growth factor β1 (TGF‐β1) from self‐assembling peptide hydrogels, a candidate scaffold for cell transplant therapies, and stimulate chondrogenesis of encapsulated young equine bone marrow stromal cells (BMSCs). Although both peptide and agarose hydrogels retained TGF‐β1, fivefold higher retention was found in peptide. Excess unlabeled TGF‐β1 minimally displaced retained radiolabeled TGF‐β1, demonstrating biologically relevant loading capacity for peptide hydrogels. The initial release from acellular peptide hydrogels was nearly threefold lower than agarose hydrogels, at 18% of loaded TGF‐β1 through 3 days as compared to 48% for agarose. At day 21, cumulative release of TGF‐β1 was 32–44% from acellular peptide hydrogels, but was 62% from peptide hydrogels with encapsulated BMSCs, likely due to cell‐mediated TGF‐β1 degradation and release of small labeled species. TGF‐β1 loaded peptide hydrogels stimulated chondrogenesis of young equine BMSCs, a relevant preclinical model for treating injuries in young human cohorts. Self‐assembling peptide hydrogels can be used to deliver chondrogenic factors to encapsulated cells making them a promising technology for in vivo, cell‐based regenerative medicine. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1275–1285, 2014.
Bed thickness distributions on Mars: An orbital perspective
Authors: Stack K. M. , Grotzinger J. P. , Milliken R. E.
Published: May 2013

Studies on Earth show that sedimentary bed thickness and bed thickness distributions record information about the processes controlling sediment deposition. High‐resolution digital terrain models (DTMs) such as those derived from the High Resolution Imaging Science Experiment (HiRISE) now provide the opportunity to quantify bed thickness properties on Mars over several orders of magnitude, down to the submeter scale. This study uses HiRISE DTMs and visible images to measure bed thickness distributions at 10 deposits on Mars, with the aim of determining whether statistical techniques can provide useful criteria for distinguishing sedimentary depositional processes. Basic statistics, including mean thickness and range, are examined, as are histograms, cumulative frequency plots, and log‐log plots. Statistical tests interrogate these deposits for thinning or thickening upward trends and the presence of normal, lognormal, and exponential distributions. Although there are challenges associated with these methods, the statistical analysis of bed thickness, coupled with morphological and mineralogical interpretations, has the potential to be a powerful tool for characterizing and classifying sedimentary rocks on Mars. In particular, bed thickness statistics are particularly well suited for examining changes in sediment supply and accommodation within Martian sedimentary sequences.
Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project I: Antarctica
Authors: Nowicki Sophie , Bindschadler Robert A. , Abe‐Ouchi Ayako , Aschwanden Andy , Bueler Ed , Choi Hyeungu , Fastook Jim , Granzow Glen , Greve Ralf , Gutowski Gail , Herzfeld Ute , Jackson Charles , Johnson Jesse , Khroulev Constantine , Larour Eric , Levermann Anders , Lipscomb William H. , Martin Maria A. , Morlighem Mathieu , Parizek Byron R. , Pollard David , Price Stephen F. , Ren Diandong , Rignot Eric , Saito Fuyuki , Sato Tatsuru , Seddik Hakime , Seroussi Helene , Takahashi Kunio , Walker Ryan , Wang Wei Li
Published: May 2013

Atmospheric, oceanic, and subglacial forcing scenarios from the Sea‐level Response to Ice Sheet Evolution (SeaRISE) project are applied to six three‐dimensional thermomechanical ice‐sheet models to assess Antarctic ice sheet sensitivity over a 500 year timescale and to inform future modeling and field studies. Results indicate (i) growth with warming, except within low‐latitude basins (where inland thickening is outpaced by marginal thinning); (ii) mass loss with enhanced sliding (with basins dominated by high driving stresses affected more than basins with low‐surface‐slope streaming ice); and (iii) mass loss with enhanced ice shelf melting (with changes in West Antarctica dominating the signal due to its marine setting and extensive ice shelves; cf. minimal impact in the Terre Adelie, George V, Oates, and Victoria Land region of East Antarctica). Ice loss due to dynamic changes associated with enhanced sliding and/or sub‐shelf melting exceeds the gain due to increased precipitation. Furthermore, differences in results between and within basins as well as the controlling impact of sub‐shelf melting on ice dynamics highlight the need for improved understanding of basal conditions, grounding‐zone processes, ocean‐ice interactions, and the numerical representation of all three.
Field‐quantified responses of tropical rainforest aboveground productivity to increasing CO2 and climatic stress, 1997–2009
Authors: Clark Deborah A. , Clark David B. , Oberbauer Steven F.
Published: May 2013

A directional change in tropical‐forest productivity, a large component in the global carbon budget, would affect the rate of increase in atmospheric carbon dioxide ([CO2]). One current hypothesis is that “CO2 fertilization” has been increasing tropical forest productivity. Some lines of evidence instead suggest climate‐driven productivity declines. Relevant direct field observations remain extremely limited for this biome. Using a unique long‐term record of annual field measurements, we assessed annual aboveground net primary productivity (ANPP) and its relation to climatic factors and [CO2] in a neotropical rainforest through 1997–2009. Over this 12 year period, annual productivity did not increase, as would be expected with a dominant CO2 fertilization effect. Instead, the negative responses of ANPP components to climatic stress far exceeded the small positive responses associated with increasing [CO2]. Annual aboveground biomass production was well explained (73%) by the independent negative effects of increasing minimum temperatures and greater dry‐season water stress. The long‐term records enable a first field‐based estimate of the [CO2] response of tropical forest ANPP: 5.24 g m−2 yr−1 yr−1 (the summed [CO2]‐associated increases in two of the four production components; the largest component, leaf litterfall, showed no [CO2] association). If confirmed by longer data series, such a small response from a fertile tropical rainforest would indicate that current global models overestimate the benefits from CO2 fertilization for this biome, where most forests' poorer nutrient status more strongly constrains productivity responses to increasing [CO2]. Given the rapidly intensifying warming across tropical regions, tropical forest productivity could sharply decline through coming decades.
Smad3 binds scleraxis and mohawk and regulates tendon matrix organization
Authors: Berthet Ellora , Chen Carol , Butcher Kristin , Schneider Richard A. , Alliston Tamara , Amirtharajah Mohana
Published: May 2013

TGFβ plays a critical role in tendon formation and healing. While its downstream effector Smad3 has been implicated in the healing process, little is known about the role of Smad3 in normal tendon development or tenocyte gene expression. Using mice deficient in Smad3 (Smad3−/−), we show that Smad3 ablation disrupts tendon architecture and has a dramatic impact on normal gene and protein expression during development as well as in mature tendon. In developing and adult tendon, loss of Smad3 results in reduced protein expression of the matrix components Collagen 1 and Tenascin‐C. Additionally, when compared to wild type, tendon from adult Smad3−/− mice shows a down regulation of key tendon marker genes. Finally, we have established that Smad3 has the ability to physically interact with the critical transcriptional regulators Scleraxis and Mohawk. Together these results indicate a central role for Smad3 in normal tendon formation and in the maintenance of mature tendon. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1475–1483, 2013
Chemical composition and ruminal nutrient degradability of fresh and ensiled amaranth forage
Authors: Seguin Philippe , Mustafa Arif F , Donnelly Danielle J , Gélinas Bruce
Published: May 2013

BACKGROUND

Amaranth is a crop with potential as a source of forage for ruminants that has not been well characterized. A study was conducted to determine the impact of ensiling on the nutritional quality and ruminal degradability of forage from two amaranth cultivars adapted to North America (i.e. Plainsman and D136). In particular, quantification and some microscopic characterization of oxalate found in amaranth were performed as it is an antiquality compound of concern.

RESULTS

There were limited interactions between cultivars and ensiling for most variables. Differences in chemical composition between amaranth cultivars were also limited. Ensiling reduced non‐structural carbohydrate and true protein contents. The proportion of acid detergent protein was high in fresh and ensiled forages of both cultivars (average of 177 g kg−1 crude protein). Total oxalate content averaged 30 and 25 g kg‐1 in fresh and ensiled forages respectively. Ensiling reduced soluble oxalate content. Crystals observed in amaranth were calcium oxalate druses found mostly in idioblast cells in leaf mesophyll and parenchyma of primary and secondary veins. In situ ruminal degradability data indicated that both fresh and ensiled amaranth are highly degradable in the rumen.

CONCLUSION

This study confirms that amaranth is a suitable forage for ruminant animals. Its chemical composition is comparable, for most variables, to that of other commonly used forage species. © 2013 Society of Chemical Industry