1,671 research outputs found
Personality and second language learning
This paper examines the relationships which exist between personality and second language learning and adds to the data available on the use of a highly respected personality indicator, the Myers Briggs Type Indicator (MBTI). Language learning and academic success are both highly correlated with intelligence, but research suggests that the importance of intelligence declines after high school age, partly because of the stronger effects of personality. This study places emphasis on the importance of personality in learning success and examines research evidence on the issue, discussing some of the inconsistent results that have been obtained. A study of 100 Hong Kong university undergraduates was carried out to add to this research base. The instruments used were the MBTI for personality traits, the Strategy Inventory for Language Learning (S.I.L.L.) for learning strategies and a standardized test for language proficiency. Significant statistical relationships were not found and the reasons for this are discussed
Identification of a non-mammalian leptin-like gene:characterization and expression in the tiger salamander (Ambystoma tigrinum)
Leptin is well established as a multifunctional cytokine in mammals. However, little is known about the evolution of the leptin gene in other vertebrates. A recently published set of ESTs from the tiger salamander (Ambystoma tigrinum) contains a sequence sharing 56% nucleotide sequence identity with the human leptin cDNA. To confirm that the EST is naturally expressed in the salamander, a 409 bp cDNA was amplified by RT-PCR of salamander testis and stomach mRNAs. The coding sequence of the cDNA is predicted to encode 169 amino acids, and the mature peptide to consist of 146 residues, as in mammals. Although the overall amino acid identity with mammalian leptins is only 29%, the salamander and mammalian peptides share common structural features. An intron was identified between coding exons providing evidence that the sequence is present in the salamander genome. Phylogenetic analysis showed a rate of molecular divergence consistent with the accepted view of vertebrate evolution. The pattern of tissue expression of the leptin-like cDNA differed between metamorphosed adult individuals of different sizes suggesting possible developmental regulation. Expression was most prominent in the skin and testis, but was also detected in tissues in which leptin mRNA is present in mammals, including the fat body, stomach, and muscle. The characterization of a salamander leptin-like gene provides a basis for understanding how the structure and functions of leptin have altered during the evolution of tetrapod vertebrates
Interfacial band-edge energetics for solar fuels production
Photoelectrochemical (PEC) water splitting has received growing attention as a potential pathway to replace fossil fuels and produce a clean, renewable, and sustainable source of fuel. To achieve overall water splitting and the associated production of solar fuels, complex devices are needed to efficiently capture light from the sun, separate photogenerated charges, and catalyze reduction and oxidation reactions. To date, the highest performing solar fuels devices rely on multi-component systems, which introduce interfaces that can be associated with further performance loss due to thermodynamic and kinetic considerations. In this review, we identify several of the most important interfaces used in PEC water splitting, summarize methods to characterize them, and highlight approaches to mitigating associated loss mechanisms.The authors thank Dr Eric Miller for the inspiration to compile this
review, and the members of the U.S. Department of Energy’s
Photoelectrochemical Working Group and Task 35 (Renewable
Hydrogen) of the International E
nergy Agency’s Hydrogen Imple-
menting Agreement for helpful comments, suggestions, and dis-
cussions, specifically Prof. Shane Ardo, Dr John Turner, Prof.
Dunwei Wang, and Prof. Shannon Boettcher. WAS greatly acknowl-
edges funding support from the FOM/NWO/Shell Program on CO
2
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neutral Fuels (Project – APPEL). IDS was supported by the Joint
Center for Artificial Photosynthesis, a DOE Energy Innovation Hub,
supported through the Office of Science of the U.S. Department of
Energy under Award Number DE-SC0004993. NCS acknowledges
start-up funds from Lehigh University. JB thanks financial support
from GeneralitatValenciana (ISIC/ 2012/008). A summary version of
this review paper (DOI: 10.2172/1209498), and associated summary
tables that will be updated as the field progresses, will be available
on the working group website (http://energy.gov/eere/fuelcells/
photoelectrochemical-working-group)
A review of published analyses of case-cohort studies and recommendations for future reporting.
The case-cohort study design combines the advantages of a cohort study with the efficiency of a nested case-control study. However, unlike more standard observational study designs, there are currently no guidelines for reporting results from case-cohort studies. Our aim was to review recent practice in reporting these studies, and develop recommendations for the future. By searching papers published in 24 major medical and epidemiological journals between January 2010 and March 2013 using PubMed, Scopus and Web of Knowledge, we identified 32 papers reporting case-cohort studies. The median subcohort sampling fraction was 4.1% (interquartile range 3.7% to 9.1%). The papers varied in their approaches to describing the numbers of individuals in the original cohort and the subcohort, presenting descriptive data, and in the level of detail provided about the statistical methods used, so it was not always possible to be sure that appropriate analyses had been conducted. Based on the findings of our review, we make recommendations about reporting of the study design, subcohort definition, numbers of participants, descriptive information and statistical methods, which could be used alongside existing STROBE guidelines for reporting observational studies.SJS was supported by the Medical Research Council www.mrc.ac.uk [Unit Programme number MC_UU_12015/1]. IRW was supported by the Medical Research Council www.mrc.ac.uk [Unit Programme number U105260558]. MP, SGT and AMW were supported by the British Heart Foundation www.bhf.org.uk
[grant number CH/12/2/29428].This is the final published version distributed under a Creative Commons Attribution License 2.0, which can also be viewed on the publisher's website at: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.010117
Expression of polycomb protein BMI-1 1 maintains the plasticity of basal 2 bronchial epithelial cells
The airway epithelium is altered in respiratory disease and is thought to contribute to disease aetiology. A caveat to disease research is that the technique of isolation of bronchial epithelial cells from patients is invasive and cells have a limited lifespan. The aim of the current study was to extensively characterise the plasticity of primary human bronchial epithelial cells that have been engineered to delay cell senescence including the ability of these cells to differentiate. Cells were engineered to express BMI-1 or hTERT using viral vector systems. Cells were characterised at passage (p) early (p5), mid (p10) and late (p15) stage for; BMI-1, p16 and CK14 protein expression, viability and the ability to differentiate at air-liquid interface (ALI), using a range of techniques including immunohistochemistry (IHC), immunofluorescence (IF), transepithelial electrical resistance (TEER), Scanning Electron Microscopy (SEM), (MUC5AC and beta tubulin (BTUB) staining). BMI-1 expressing cells maintained elevated levels of the BMI-1 protein and the epithelial marker CK14 and showed a suppression of p16. BMI-1 expressing cells had a viability advantage, differentiated at ALI and had a normal karyotype. In contrast hTERT expressing cells had a reduced viability, showed limited differentiation and had an abnormal karyotype. We therefore provide extensive characterisation of the plasticity of BMI-1 expression cells in the context of the ALI model. These cells retain properties of wild-type cells and may be useful to characterise respiratory disease mechanisms in vitro over sustained periods
Comparison of dimethyl sulfoxide treated highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) electrodes for use in indium tin oxide-free organic electronic photovoltaic devices
Indium tin oxide (ITO)-free organic photovoltaic (OPV) devices were fabricated using highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the transparent conductive electrode (TCE). The intrinsic conductivity of the PEDOT:PSS films was improved by two different dimethyl sulfoxide (DMSO) treatments – (i) DMSO was added directly to the PEDOT:PSS solution (PEDOT:PSSADD) and (ii) a pre-formed PEDOT:PSS film was immersed in DMSO (PEDOT:PSSIMM). X-ray photoelectron spectroscopy (XPS) and conductive atomic force microscopy (CAFM) studies showed a large amount of PSS was removed from the PEDOT:PSSIMM electrode surface. OPV devices based on a poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) bulk hetrojunction showed that the PEDOT:PSSIMM electrode out-performed the PEDOT:PSSADD electrode, primarily due to an increase in short circuit current density from 6.62 mA cm−2 to 7.15 mA cm−2. The results highlight the importance of optimising the treatment of PEDOT:PSS electrodes and demonstrate their potential as an alternative TCE for rapid processing and low-cost OPV and other organic electronic devices
Orexin in the chicken hypothalamus: immunocytochemical localisation and comparison of mRNA concentrations during the day and night, and after chronic food restriction
In mammals Orexin-A and -B are neuropeptides involved in the hypothalamic regulation
of diverse physiological functions including food intake and the sleep-wake cycle. This
generalisation was investigated in meat-(broiler) and layer-type juvenile domestic chickens
by immunocytochemical localisation of orexin A/B in the hypothalamus, and by
measurements of hypothalamic hypocretin mRNA which encodes for orexin A/B after
chronic food restriction, and during the sleep-wake cycle. Orexin immunoreactive fibres
were observed throughout the hypothalamus with cell bodies in and around the
paraventricular nucleus. No differences were observed in the pattern of immunoreactivity
using anti- human orexin-A, or -B antisera. The amount of hypothalamic hypocretin
mRNA in food -restricted broilers was higher than in broilers fed ad libitum, but the same as
in layer- type hens fed ad libitum. Hypothalamic hypocretin mRNA was increased (Po0.01)
in 12-week-old broilers fed 25% of their ad libitum intake between 6–12 weeks of age. No
difference in hypothalamic hypocretin mRNA was seen in 12-week-old layer- type hens
when they were awake (1–2 h after lights on) or sleeping (1–2 h after lights off). It is
concluded that in the chicken, we could not find evidence that hypothalamic orexin plays a
role in the sleep-wake cycle and it may be involved in aspects of energy balance
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