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1. Extraction, optimization, and characterization of lipids from spent hens: An unexploited sustainable bioresource

Author:
Ullah, Aman,   et al.   ; Safder, Muhammad; Temelli, Feral;     Show all 3 Authors
Source:
Journal of cleaner production 2019 v.206 pp. 622-630
ISSN:
0959-6526
Subject:
Fourier transform infrared spectroscopy; biomass; differential scanning calorimetry; fatty acid composition; flame ionization; industrial byproducts; linoleic acid; lipid content; magnetism; market value; mass spectrometry; microwave treatment; moieties; oleic acid; palmitic acid; phase transition; poultry industry; quantitative analysis; response surface methodology; spent hens; standard deviation; temperature; thermal degradation; thermogravimetry
Abstract:
... Spent hen, a poultry industry by-product with little market value and high lipid content, can be used as a new and sustainable biomass source for lipid production. This study focused on conventional extraction methods and compared them with the microwave-assisted extraction of lipids from the spent hen. Over 95% of the lipids were recovered within 10 min using microwaves. Factors affecting the ext ...
DOI:
10.1016/j.jclepro.2018.09.214

2. Adequate zinc nutrition improves the tolerance against drought and heat stresses in chickpea

Author:
Ullah, Aman,   et al.   ; Romdhane, Leila; Rehman, Abdul; Farooq, Muhammad;     Show all 4 Authors
Source:
Plant physiology and biochemistry 2019 v.143 pp. 11-18
ISSN:
0981-9428
Subject:
adverse effects; antioxidant activity; carbon dioxide fixation; chickpeas; climatic factors; drought; genotype; heat; heat stress; night temperature; nutrition; photosystem II; phytomass; plant growth; soil; water holding capacity; zinc
Abstract:
... Two chickpea genotypes viz. Bhakar-2011 (desi) and Noor-2013 (kabuli) were sown in soil filled pots supplied with low (0.3 mg kg−1) and high (3 mg kg−1 soil) zinc (Zn) under control (70% water holding capacity and 25/20 °C day/night temperature), drought (35% water holding capacity) and heat (35/30 °C day/night temperature) stresses. Drought and heat stresses reduced rate of photosynthesis, photos ...
DOI:
10.1016/j.plaphy.2019.08.020

3. Unravelled keratin-derived biopolymers as novel biosorbents for the simultaneous removal of multiple trace metals from industrial wastewater

Author:
Ullah, Aman,   et al.   ; Donner, Mark W.; Arshad, Muhammad; Siddique, Tariq;     Show all 4 Authors
Source:
The Science of the total environment 2019 v.647 pp. 1539-1546
ISSN:
0048-9697
Subject:
adsorption; biopolymers; biosorbents; chemical reduction; cobalt; feathers; industrial effluents; lead; nickel; poultry; raw materials; toxicity; wastewater; water treatment; zinc
Abstract:
... Biopolymers derived from modified poultry feathers (KB) were developed to target a broad range of potentially toxic trace elements for their removal from synthetic wastewater and industrial process affected water. The chemical modifications increased surface functionality of KBs for enhanced metal adsorption. Unmodified KB (SM-03) added to synthetic wastewater spiked with nine transition and redox ...
DOI:
10.1016/j.scitotenv.2018.08.085

4. Keratin and Chitosan Biosorbents for Wastewater Treatment: A Review

Author:
Ullah, Aman,   et al.   ; Saha, Sarthak; Zubair, Muhammad; Khosa, M. A.; Song, Sandra;     Show all 5 Authors
Source:
Journal of polymers and the environment 2019 v.27 no.7 pp. 1389-1403
ISSN:
1566-2543
Subject:
biocompatible materials; biopolymers; biosorbents; biosorption; chitosan; fauna; flora; green chemistry; heavy metals; human health; industry; keratin; metal ions; minerals; organic matter; surface water; toxicity; wastewater treatment; water pollution; water quality
Abstract:
... Heavy metal ions and their toxic complexes with minerals and organic matter significantly affect the quality of water bodies. Such metallic complexes and excessive minerals are of non-biodegradable nature posing a serious threat to fauna, flora, and human health. Therefore, removal of metal ions and organic matters from water is highly desirable in benign chemistry. Over the years, biomaterials ha ...
DOI:
10.1007/s10924-019-01439-6

5. Effect of different densities of parthenium weed (Parthenium hysterophorus L.) on the performance of direct-seeded rice under aerobic conditions

Author:
Ullah, Aman,   et al.   ; Bajwa, Ali Ahsan; Farooq, Muhammad; Chauhan, Bhagirath Singh; Adkins, Steve;     Show all 5 Authors
Source:
Archiv für Acker- und Pflanzenbau und Bodenkunde 2019 v.65 no.6 pp. 796-808
ISSN:
1476-3567
Subject:
Parthenium hysterophorus; aerobic conditions; biomass; direct seeding; grain yield; panicles; plant density; rice; weeds
Abstract:
... Parthenium weed (Parthenium hysterophorus L.) is an emerging weed species in direct-seeded aerobic systems of rice production. This two-year field study was conducted to evaluate the effect of five different densities (0, 5, 10, 15 and 20 plants m⁻²) of parthenium weed on rice yield and yield-related attributes. Parthenium weed produced ca. 38 to 178% higher biomass at its densities of 10 to 20 pl ...
DOI:
10.1080/03650340.2018.1525705

6. Chemical control of parthenium weed (Parthenium hysterophorus L.) in two contrasting cultivars of rice under direct-seeded conditions

Author:
Ullah, Aman,   et al.   ; Bajwa, Ali Ahsan; Farooq, Muhammad; Chauhan, Bhagirath Singh; Adkins, Steve;     Show all 5 Authors
Source:
Crop protection 2019 v.117 pp. 26-36
ISSN:
0261-2194
Subject:
Parthenium hysterophorus; bensulfuron-methyl; biomass; bispyribac-sodium; branches; chemical control; costs and returns; cultivars; direct seeding; financial economics; grain yield; microclimate; panicles; pendimethalin; plant density; plant height; profitability; rice; seeds; weed control
Abstract:
... Parthenium weed is an emerging problem in direct-seeded rice due to the suitable microclimatic conditions for its establishment in this system. This two-years field study evaluated the potential of pendimethalin (pre-emergence) and bispyribac-sodium plus bensulfuron-methyl (post-emergence) herbicides to control parthenium weed when applied alone or in combination in two rice cultivars, Basmati-200 ...
DOI:
10.1016/j.cropro.2018.11.009

7. Overview of wastewater treatment methods with special focus on biopolymer chitin-chitosan

Author:
Ullah, Aman,   et al.   ; Sarode, Shruti; Upadhyay, Punita; Khosa, M.A.; Mak, Tony; Shakir, Abdus; Song, Sandra;     Show all 7 Authors
Source:
International journal of biological macromolecules 2019 v.121 pp. 1086-1100
ISSN:
0141-8130
Subject:
anions; aqueous solutions; biodegradability; biopolymers; biosorption; chitin; chitosan; cost effectiveness; electrostatic interactions; half life; heavy metals; ionization; metal ions; remediation; wastewater; zeta potential
Abstract:
... Heavy metals have substantively high values of half-lives with nonbiodegradable chemical nature. At the same time, their ionic compounds have amazing ability of ionization in aqueous media. Remediation of such metals from wastewaters has been very complex, expensive and a challenging goal for ages. Several methods have been employed to segregate heavy metals and their corresponding anions, and org ...
DOI:
10.1016/j.ijbiomac.2018.10.089

8. The second-order bias of quantile estimators

Author:
Ullah, Aman,   et al.   ; Lee, Tae-Hwy; Wang, He;     Show all 3 Authors
Source:
Economics letters 2018 v.173 pp. 143-147
ISSN:
0165-1765
Subject:
Monte Carlo method; income distribution; regression analysis; risk management
Abstract:
... The finite sample theory using higher-order asymptotics provides better approximations of the bias for a class of estimators. Phillips (1991) demonstrated the higher-order asymptotic expansions for LAD estimators. Rilstone et al. (1996) provided the second-order bias results of conditional mean regression estimators. This paper develops new analytical results on the second-order bias of the condit ...
DOI:
10.1016/j.econlet.2018.09.022

9. Whole exome sequencing identified two novel homozygous missense variants in the same codon of CLCN7 underlying autosomal recessive infantile malignant osteopetrosis in a Pakistani family

Author:
Ullah, Aman,   et al.   ; Khan, Muhammad Aman; Naeem, Muhammad;     Show all 3 Authors
Source:
Molecular biology reports 2018 v.45 no.4 pp. 565-570
ISSN:
0301-4851
Subject:
bioinformatics; chromosomes; counseling; genome; heterozygosity; homozygosity; parents; phenotype; prediction; restriction fragment length polymorphism; sequence analysis
Abstract:
... Autosomal recessive osteopetrosis is a severe fatal disorder with an average incidence of around 1:250,000. It is diagnosed soon after birth or within the 1st year of life with severe symptoms of abnormal bone remodelling. This study was aimed to identify the underlying genetic cause of the disease in a Pakistani family segregating infantile malignant osteopetrosis in autosomal recessive pattern. ...
DOI:
10.1007/s11033-018-4194-8

10. In-Situ Nanoreinforced Green Bionanomaterials from Natural Keratin and Montmorillonite (MMT)/Cellulose Nanocrystals (CNC)

Author:
Ullah, Aman,   et al.   ; Kaur, Manpreet; Arshad, Muhammad;     Show all 3 Authors
Source:
ACS sustainable chemistry & engineering 2018 v.6 no.2 pp. 1977-1987
ISSN:
2168-0485
Subject:
Fourier transform infrared spectroscopy; X-ray photoelectron spectroscopy; biocompatible materials; biocomposites; biodegradability; biopolymers; cellulose; chemical bonding; chickens; compression molding; differential scanning calorimetry; glass transition temperature; keratin; montmorillonite; nanocomposites; nanocrystals; nanoparticles; scanning electron microscopy; tensile strength; thermal stability; thermogravimetry; transmission electron microscopy; wide-angle X-ray scattering
Abstract:
... Biodegradability and renewability has led renewed interest in protein based films reinforced with nanoparticles. Bionanocomposites have gained attention because of their enhanced material properties with the aid of nanoreinforcements. The effects of two different nanoparticles, montmorillonite (MMT) and cellulose nanocrystals (CNCs), at different loading contents (0%, 1%, 3%, 5%, and 10%) were stu ...
DOI:
10.1021/acssuschemeng.7b03380

11. A class of model averaging estimators

Author:
Ullah, Aman,   et al.   ; Zhao, Shangwei; Zhang, Xinyu;     Show all 3 Authors
Source:
Economics letters 2018 v.162 pp. 101-106
ISSN:
0165-1765
Subject:
economics; models
Abstract:
... Model averaging aims to a trade-off between efficiency and biases. In this paper, a class of model averaging estimators, g-class, is introduced, and its dominance condition over the ordinary least squares estimator is established. All theoretical findings are verified by simulations. ...
DOI:
10.1016/j.econlet.2017.10.023

12. Microwave-assisted rapid synthesis of a polyether from a plant oil derived monomer and its optimization by Box–Behnken design

Author:
Ullah, Aman,   et al.   ; Ahmadi, Reza;     Show all 2 Author
Source:
RSC advances 2017 v.7 no.45 pp. 27946-27959
ISSN:
2046-2069
Subject:
Fourier transform infrared spectroscopy; differential scanning calorimetry; epoxidation reactions; equations; experimental design; gel chromatography; melting point; microwave radiation; microwave treatment; molecular weight; nuclear magnetic resonance spectroscopy; olefin; polymerization; polymers; reflectance; regression analysis; solvents; temperature; thermogravimetry
Abstract:
... In this study, a new strategy for making polyethers from α-olefin (1-decene) was developed using microwave irradiation and compared with a conventional method. The olefin was epoxidized and subjected to catalytic polymerization using both conventional and microwave synthesis techniques. The conventional epoxidation reaction of 1-decene took 1 hour while microwave-assisted epoxidation was completed ...
DOI:
10.1039/c7ra03278a

13. Preparation and characterization of graphite oxide nano‐reinforced biocomposites from chicken feather keratin

Author:
Ullah, Aman,   et al.   ; Esparza, Yussef; Wu, Jianping;     Show all 3 Authors
Source:
Journal of chemical technology and biotechnology 2017 v.92 no.8 pp. 2023-2031
ISSN:
0268-2575
Subject:
biocomposites; chickens; cost effectiveness; extrusion; graphene; industrial byproducts; keratin; moieties; nanocomposites; oxygen; petroleum; plastic film; plasticizers; tensile strength; thermal properties; thermoplastics
Abstract:
... BACKGROUND: Natural polymers have gained increased attention in reducing the dependence on petroleum‐based materials. Chicken feather proteins are an abundant industrial by‐product suitable for the fabrication of sustainable thermoplastics. However, protein‐based plastics generally exhibit poor physical and thermal properties which limit their application. In this research, the fabrication of feat ...
DOI:
10.1002/jctb.5196

14. Molecular mechanism and characterization of self-assembly of feather keratin gelation

Author:
Ullah, Aman,   et al.   ; Esparza, Yussef; Wu, Jianping;     Show all 3 Authors
Source:
International journal of biological macromolecules 2017
ISSN:
0141-8130
Subject:
cysteine; dialysis; feathers; gelation; hydrogels; hydrogen bonding; hydrophobic bonding; keratin; pH; storage modulus; temperature; thiols; viscoelasticity
Abstract:
... Protein gels with controlled viscoelastic properties could find numerous material and biomedical applications. Feather keratin is naturally abundant protein while its gelation property has not been explored. In this study hydrogel from fully reduced feather keratin was prepared by dialysis. The objectives of this work were to study the molecular mechanism of self-assembly of feather keratin gel an ...
DOI:
10.1016/j.ijbiomac.2017.08.168

15. Desi chickpea genotypes tolerate drought stress better than kabuli types by modulating germination metabolism, trehalose accumulation, and carbon assimilation

Author:
Ullah, Aman,   et al.   ; Farooq, Muhammad; Lee, Dong-Jin; Alghamdi, Salem S.; Siddique, Kadambot H.M.;     Show all 5 Authors
Source:
Plant physiology and biochemistry 2018 v.126 pp. 47-54
ISSN:
0981-9428
Subject:
alpha-amylase; carbon dioxide fixation; chickpeas; climate; drought; drought tolerance; enzyme activity; genotype; germination; leaf area; mineral content; nitrogen; phenolic compounds; photosynthesis; plant growth; planting; potassium; proline; reducing sugars; seedlings; soil water; stand establishment; sucrose; transpiration; trehalose; water holding capacity; water stress; water use efficiency
Abstract:
... Chickpea is mostly grown in rainfed environments and, consequently, its growth is affected by drought stress. This study comprised two independent experiments to investigate the physiological basis of drought tolerance in desi and kabuli chickpea genotypes. In Experiment 1, six genotypes each of desi and kabuli types were planted in soil-filled pots under natural conditions. Ten days after plantin ...
DOI:
10.1016/j.plaphy.2018.02.020

16. Synthesis of Fully Biobased Polyesters from Plant Oil

Author:
Ullah, Aman,   et al.   ; Jin, Liejiang; Geng, Keyu; Arshad, Muhammad; Ahmadi, Reza;     Show all 5 Authors
Source:
ACS sustainable chemistry 2017 v.5 no.11 pp. 9793-9801
ISSN:
2168-0485
Subject:
Fourier transform infrared spectroscopy; alkenes; biopolyesters; catalysts; differential scanning calorimetry; fatty acid methyl esters; gas chromatography-mass spectrometry; gel chromatography; heat; ionization; melting point; microwave radiation; molecular weight; nuclear magnetic resonance spectroscopy; oleic acid; plant fats and oils; polymerization; temperature; thermogravimetry
Abstract:
... Self-metathesis of fatty acid methyl esters (FAMEs) from natural oils and commercial oleic acid was carried out using a microwave reactor in solvent-free conditions. Self-metathesis products were further identified and quantified by gas chromatography–mass spectroscopy (GC–MS) and gas chromatography–flame ionization detector (GC–FID). Conversion of ∼50% was achieved within a short span (∼2 min) in ...
DOI:
10.1021/acssuschemeng.7b01668

17. Characterizing bread wheat genotypes of Pakistani origin for grain zinc biofortification potential

Author:
Ullah, Aman,   et al.   ; Rehman, Abdul; Farooq, Muhammad; Nawaz, Ahmad; Al‐Sadi, Abdullah M; Al-Hashmi, Khalid S; Nadeem, Faisal;     Show all 7 Authors
Source:
Journal of the science of food and agriculture 2018 v.98 no.13 pp. 4824-4836
ISSN:
0022-5142
Subject:
bioavailability; biofortification; breeding programs; calcium; endosperm; genetic variation; genotype; grain protein; grain yield; high-yielding varieties; malnutrition; phytic acid; wheat; zinc; Pakistan
Abstract:
... BACKGROUND: Zinc (Zn) is essential for all life forms and its deficiency is a major issue of malnutrition in humans. This study was carried out to characterize 28 wheat genotypes of Pakistani origin for grain zinc biofortification potential, genetic diversity and relatedness. RESULTS: There was low genetic differentiation among the tested genotypes. However, they differed greatly in yield‐related ...
DOI:
10.1002/jsfa.9010

18. Manganese nutrition improves the productivity and grain biofortification of bread wheat in alkaline calcareous soil

Author:
ULLAH, AMAN,   et al.   ; FAROOQ, MUHAMMAD; REHMAN, ABDUL; ARSHAD, MUHAMMAD SHAKEEL; SHOUKAT, HIRA; NADEEM, ASIF; NAWAZ, AHMAD; WAKEEL, ABDUL; NADEEM, FAISAL;     Show all 9 Authors
Source:
Experimental agriculture 2018 v.54 no.5 pp. 744-754
ISSN:
1469-4441
Subject:
biofortification; calcareous soils; cost benefit analysis; cost effectiveness; costs and returns; foliar application; grain yield; humans; manganese; nutrition; seed dressings; seed priming; seeds; wheat
Abstract:
... Manganese (Mn) is one important microelement for plants and the human beings. This study was conducted to evaluate the potential of Mn nutrition in improving the productivity and grain biofortification of wheat. For optimization of Mn seed treatments, seeds were primed with 0.1 and 0.01 M Mn solution, or were coated with 250 and 500 mg Mn kg⁻¹ seed. The optimized treatments were used in the second ...
DOI:
10.1017/S0014479717000369

19. Application of zinc improves the productivity and biofortification of fine grain aromatic rice grown in dry seeded and puddled transplanted production systems

Author:
Ullah, Aman,   et al.   ; Farooq, Muhammad; Rehman, Abdul; Nawaz, Ahmad; Nadeem, Asif; Wakeel, Abdul; Nadeem, Faisal; Siddique, Kadambot H.M.;     Show all 8 Authors
Source:
Field crops research 2018 v.216 pp. 53-62
ISSN:
0378-4290
Subject:
Oryza sativa; biofortification; coatings; cultivars; drying; farmers; foliar spraying; grain yield; human nutrition; production technology; profitability; puddling; rice; seed dressings; seed priming; soil; soil treatment; sowing; wages and remuneration; water management; water shortages; zinc; zinc sulfate; Pakistan
Abstract:
... Zinc (Zn) deficiency is a major constraint for rice (Oryza sativa L.) production and a global concern for human nutrition. Water scarcity and increasing labour costs are dictating the shift in rice culture from puddling, transplanting and flooding to dry seeding and the use of alternate wetting and drying water management. These changes may affect Zn availability to rice plants. This study was con ...
DOI:
10.1016/j.fcr.2017.11.004

20. On the dominance of Mallows model averaging estimator over ordinary least squares estimator

Author:
Ullah, Aman,   et al.   ; Zhang, Xinyu; Zhao, Shangwei;     Show all 3 Authors
Source:
Economics letters 2016 v.142 pp. 69-73
ISSN:
0165-1765
Subject:
economics; models
Abstract:
... This note studies Mallows model averaging method for finite sample size situation. Sufficient conditions under which the model averaging estimator dominates the ordinary least squares estimator are provided with respect to mean squared error. ...
DOI:
10.1016/j.econlet.2016.02.027

21. Green Biocomposites from Nanoengineered Hybrid Natural Fiber and Biopolymer

Author:
Ullah, Aman,   et al.   ; Arshad, Muhammad; Kaur, Manpreet;     Show all 3 Authors
Source:
ACS sustainable chemistry 2016 v.4 no.3 pp. 1785-1793
ISSN:
2168-0485
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; X-ray photoelectron spectroscopy; adhesion; biocomposites; biopolymers; composite polymers; flammability; keratin; nanoclays; polymerization; scanning electron microscopy; stearic acid; storage modulus; styrene; thermal stability; transmission electron microscopy
Abstract:
... The surface grafting of polyhedral oligomeric silsesquioxanes (POSS) nanocages onto keratin biofiber and development of hybrid keratin fiber by dissolution of feather keratin, exfoliation/intercalation of nanoclay in the keratin matrix and regeneration into fiber are reported, respectively. The graft polymerization of POSS on to the surface of keratin fibers was observed by scanning electron micro ...
DOI:
10.1021/acssuschemeng.5b01772

22. Manganese nutrition improves the productivity and grain biofortification of fine grain aromatic rice in conventional and conservation production systems

Author:
Ullah, Aman,   et al.   ; Farooq, Muhammad; Nadeem, Asif; Rehman, Abdul; Asad, Saeed A.; Nawaz, Ahmad;     Show all 6 Authors
Source:
Paddy and water environment 2017 v.15 no.3 pp. 563-572
ISSN:
1611-2490
Subject:
Oryza sativa; biofortification; coatings; cost benefit analysis; cost effectiveness; direct seeding; foliar spraying; grain yield; manganese; nutrition; production technology; rice; seed dressings; seed priming; soil treatment; Pakistan
Abstract:
... Manganese (Mn) deficiency is prevalent in rice-growing regions resulting in poor paddy yield and human health. In this study, role of Mn, applied through various methods, in improving the productivity and grain biofortification of fine grain aromatic rice was evaluated. Manganese was delivered as soil application (SA) (0.5 kg ha⁻¹), foliar spray (FA) (0.02 M Mn), seed priming (SP) (0.1 M Mn) and s ...
DOI:
10.1007/s10333-016-0573-8

23. Modified biopolymers as sorbents for the removal of naphthenic acids from oil sands process affected water (OSPW)

Author:
Ullah, Aman,   et al.   ; Arshad, Muhammad; Khosa, M.A.; Siddique, Tariq;     Show all 4 Authors
Source:
Chemosphere 2016 v.163 pp. 334-341
ISSN:
0045-6535
Subject:
biopolymers; biosorption; bitumen; corrosion; gases; goethite; hydrocarbons; keratin; metals; mine tailings; models; naphthenates; oil sands; ponds; refining; sorbents; thermal properties; toxicity
Abstract:
... Oil sands operations consume large volumes of water in bitumen extraction process and produce tailings that express pore water to the surface of tailings ponds known as oil sands process-affected water (OSPW). The OSPW is toxic and cannot be released into the environment without treatment. In addition to metals, dissolved solids, dissolved gases, hydrocarbons and polyaromatic compounds etc., OSPW ...
DOI:
10.1016/j.chemosphere.2016.08.015

24. In-situ modification, regeneration, and application of keratin biopolymer for arsenic removal

Author:
Ullah, Aman,   et al.   ; Khosa, Muhammad A.;     Show all 2 Author
Source:
Journal of hazardous materials 2014 v.278 pp. 360-371
ISSN:
0304-3894
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; allyl alcohol; arsenic; biopolymers; biosorbents; chickens; ethylene glycol; feathers; keratin; models; pH; polyethylene glycol; regression analysis; scanning electron microscopy; solubilization; sorption; sorption isotherms; thermal degradation; thermodynamics; water pollution
Abstract:
... Chemical modification of chicken feathers (CF) and their subsequent role in arsenic removal from water is presented in this paper. The ground CF were chemically treated with four selective dopants such as poly (ethylene glycol) (PEG) diglycidyl ether, poly (N-isopropylacrylamide) (PNIPAM), allyl alcohol (AA) and TrisilanolCyclohexyl POSS. After modification, the solubilized keratin was regenerated ...
DOI:
10.1016/j.jhazmat.2014.06.023

25. Heat stress in grain legumes during reproductive and grain-filling phases

Author:
Ullah, Aman,   et al.   ; Farooq, Muhammad; Nadeem, Faisal; Gogoi, Nirmali; Alghamdi, Salem S.; Nayyar, Harsh; Siddique, Kadambot H. M.;     Show all 7 Authors
Source:
Crop & pasture science 2017 v.68 no.11 pp. 985-1005
ISSN:
1836-0947
Subject:
temperature; filling period; legumes; heat tolerance; developmental stages; carbohydrates; breeding; heat stress; microspores; dehiscence; genetic engineering; grain quality; climate models; grain yield; photosynthesis; crop management; leaves; crops
Abstract:
... Thermal stress during reproductive development and grain-filling phases is a serious threat to the quality and productivity of grain legumes. The optimum temperature range for grain legume crops is 10-36°C, above which severe losses in grain yield can occur. Various climatic models have simulated that the temperature near the earth’s surface will increase (by up to 4°C) by the end of this century, ...
DOI:
10.1071/CP17012

26. Nonparametric and semiparametric regressions subject to monotonicity constraints: Estimation and forecasting

Author:
Ullah, Aman,   et al.   ; Lee, Tae-Hwy; Tu, Yundong;     Show all 3 Authors
Source:
Journal of econometrics 2014 v.182 no.1 pp. 196-210
ISSN:
0304-4076
Subject:
Monte Carlo method; econometric models; economic analysis; economic theory; prediction; regression analysis
Abstract:
... This paper considers nonparametric and semiparametric regression models subject to monotonicity constraint. We use bagging as an alternative approach to Hall and Huang (2001). Asymptotic properties of our proposed estimators and forecasts are established. Monte Carlo simulation is conducted to show their finite sample performance. An application to predicting equity premium is taken for illustrati ...
DOI:
10.1016/j.jeconom.2014.04.018

27. PEG–lipid telechelics incorporating fatty acids from canola oil: synthesis, characterization and solution self-assembly

Author:
Ullah, Aman,   et al.   ; Arshad, Muhammad; Saied, Sumayya;     Show all 3 Authors
Source:
RSC advances 2014 v.4 no.50 pp. 26439-26446
ISSN:
2046-2069
Subject:
Fourier transform infrared spectroscopy; abscisic acid; azides; canola oil; drug carriers; fatty acids; glycerol; hydrophilic polymers; light scattering; moieties; nanoparticles; particle size; polyethylene glycol; transmission electron microscopy
Abstract:
... The synthesis of amphiphilic, ABA type, novel PEG–lipid telechelics and their solution self-assembly have been reported. Natural fatty acids were functionalized with a propargyl group. Poly(ethylene glycol) (PEG) and glycerol ethoxylate (GE) were functionalized with terminal azides. The functionalized PEG, GE and fatty acids were then conjugated using click chemistry. Characterization of these con ...
DOI:
10.1039/c4ra03583f

28. Bias in the estimation of mean reversion in continuous-time Lévy processes

Author:
Ullah, Aman,   et al.   ; Bao, Yong; Wang, Yun; Yu, Jun;     Show all 4 Authors
Source:
Economics letters 2015 v.134 pp. 16-19
ISSN:
0165-1765
Subject:
economics
Abstract:
... This paper develops the approximate bias of the ordinary least squares estimator of the mean reversion parameter in continuous-time Lévy processes. Several cases are considered, depending on whether the long-run mean is known or unknown and whether the initial condition is fixed or random. The approximate bias is used to construct a bias corrected estimator. The performance of the approximate bias ...
DOI:
10.1016/j.econlet.2015.06.002

29. Chemical modification, characterization, and application of chicken feathers as novel biosorbents

Author:
Ullah, Aman,   et al.   ; Khosa, Muhammad Arshad; Wu, Jianping;     Show all 3 Authors
Source:
RSC advances 2013 v.3 no.43 pp. 20800-20810
ISSN:
2046-2069
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; arsenic; biosorbents; biosorption; chickens; differential scanning calorimetry; esterification; feathers; keratin; mechanistic models; methanol; pH; raw materials; scanning electron microscopy; sodium hydroxide; sodium sulfite; thermogravimetry; water pollution
Abstract:
... The current work exclusively pertains to preparing arsenic removing biosorbents using chicken feathers (CF) as a raw material. CF consist of keratinous proteins with many functional groups, and this paper contributes to the debate on how functional groups, especially –COOH, –NH₂ and –S–S–, interact with arsenic species before and after their modification through sorption phenomena. Chemically modi ...
DOI:
10.1039/c3ra43787f

30. On existence of moment of mean reversion estimator in linear diffusion models

Author:
Ullah, Aman,   et al.   ; Bao, Yong; Zinde-Walsh, Victoria;     Show all 3 Authors
Source:
Economics letters 2013 v.120 no.2 pp. 146-148
ISSN:
0165-1765
Subject:
economics; models
Abstract:
... In this note it is shown that the expectation of the usual MLE estimator of the mean-reversion parameter in linear diffusion models does not exist. However, the moment does exist conditionally on the estimator of the autoregressive parameter in the discretized model being positive. ...
DOI:
10.1016/j.econlet.2013.04.024

31. A semiparametric conditional duration model

Author:
Ullah, Aman,   et al.   ; Dungey, Mardi; Long, Xiangdong; Wang, Yun;     Show all 4 Authors
Source:
Economics letters 2014 v.124 no.3 pp. 362-366
ISSN:
0165-1765
Subject:
economics; models; United States
Abstract:
... We propose a new semiparametric autoregressive duration (SACD) model, which incorporates the parametric and nonparametric estimators of the conditional duration in a multiplicative way. Asymptotic properties for this combined estimator are presented. The empirical application to the transaction duration of the US 2-Year Treasury note shows the outperformance of our SACD models over parametric ACD ...
DOI:
10.1016/j.econlet.2014.06.013

32. High strain response in ternary Bi₀.₅Na₀.₅TiO₃–BaTiO₃–Bi(Mn₀.₅Ti₀.₅)O₃ solid solutions

Author:
Ullah, Aman,   et al.   ; Alam, Mehtab; Ullah, Amir; Ahn, Chang Won; Lee, Jae-Shin; Cho, Shinuk; Kim, Ill Won;     Show all 7 Authors
Source:
RSC advances 2016 v.6 no.68 pp. 63915-63921
ISSN:
2046-2069
Subject:
X-ray diffraction; ambient temperature; ceramics; electric field; solid solutions
Abstract:
... In this study, a ternary solid solution (0.935 − x)BNT–0.065BT–xBi(Mn₀.₅Ti₀.₅)O₃ (BNT–BT–BMnT; x = 0–0.030) was designed and fabricated by means of a conventional fabrication process. The composition and temperature dependencies of this material’s dielectric, ferroelectric and strain behavior were systematically investigated. XRD patterns of the BNT–BT–BMnT ceramics showed a single perovskite phas ...
DOI:
10.1039/c6ra08240h

33. Seroprevalence of Leptospira spp. in Horses of Distinct Climatic Regions of Punjab, Pakistan

Author:
Ullah, Aman,   et al.   ; Sohail, Muhammad Luqman; Khan, Muhammad Sarwar; Avais, Muhammad; Zahoor, Muhammad Yasir; Ijaz, Muhammad; Fatima, Zahida; Naseer, Omer; Khattak, Irfan; Ali, Sadaqat;     Show all 10 Authors
Source:
Journal of equine veterinary science 2016 v.44 pp. 82-89
ISSN:
0737-0806
Subject:
Leptospira; confidence interval; enzyme-linked immunosorbent assay; epidemiological studies; gender; herd size; horses; jaundice; leptospirosis; rearing; regression analysis; reproductive disorders; risk factors; rodents; seroprevalence; wild animals; zoonoses; Pakistan
Abstract:
... Leptospirosis is zoonotic disease which is globally distributed among many domestic and wild animals. In equines, it causes uveitis, jaundice, and reproductive disorders. A cross-sectional epidemiological study was conducted for the first time in Pakistan to unveil the seroprevalence and to identify associated risk factors of leptospirosis in distinct climatic regions. A total of 384 horse sera (n ...
DOI:
10.1016/j.jevs.2016.01.007

34. Effect of high pressure treatment on ovotransferrin

Author:
Ullah, Aman,   et al.   ; Acero-Lopez, Alexandra; Offengenden, Marina; Jung, Stephanie; Wu, Jianping;     Show all 5 Authors
Source:
Food chemistry 2012 v.135 no.4 pp. 2245-2252
ISSN:
0308-8146
Subject:
Fourier transform infrared spectroscopy; denaturation; differential scanning calorimetry; enthalpy; fluorescence; high pressure treatment; hydrophobicity; pH; sulfhydryl groups; temperature
Abstract:
... High pressure processing of ovotransferrin was carried out to study the structural and physiochemical changes of ovotransferrin under various pressure levels. At pH 8 and pressures higher than 200MPa, a decrease in total sulfhydryl groups and an increase in surface hydrophobicity were observed along with a partial aggregation. A gradual shift of denaturation peak towards higher temperature was not ...
DOI:
10.1016/j.foodchem.2012.07.071
PubMed:
22980798