47,931 research outputs found
Linkage and expression of foreign DNA in cultured animal cells
No full textThe ability to introduce defined genes into cultured cells radically alters the prospects for understanding differentiation and growth control in higher organisms. Stable transformation of animal cells may be effected by the delivery of DNA as a calcium phosphate coprecipitate (Graham and van der Eb 1973). Since the uptake and expression of DNA is a relatively rare event, transformants are usually isolated by selection for cells that have acquired a new phenotype. For this purpose the thymidine kinase (tk)1 gene of herpes simplex virus type 1 (HSV-1) is often used as the selectable vector with tk+ recipient cells (Wigler et al. 1977). The tk+ transformants are then selected in HAT medium. Nonselectable genes may be stably introduced into cells either by direct ligation to the selectable vector (Mantei et al. 1979) or by unlinked cotransformation (Wigler et al. 1979b)
Genetics. Wild by nature
No full textHow do networks of biological molecules, such as signal transduction pathways, operate, and are their behaviors predictable? In a Perspective, Wigler and Mishra explain a new study ( Guet et al.) where the authors have designed a genetic combinatorial network and examined the predictability of its behavior
Ras partners
No full textThe RAS oncogenes were first discovered as the transforming elements of acutely oncogenic retroviruses. Subsequently, cellular RAS genes were found to be frequently activated by mutation in a wide variety of human cancers, providing the first example of a common oncogenic mechanism. As a consequence, Ras proteins have been studied extensively (for review, see Barbacid 1987).
RAS genes are found ubiquitously in eukaryotic organisms. They encode low-molecular-weight guanine nucleotide-binding proteins that hydrolyze GTP and localize to the inner surface of the plasma membrane after undergoing elaborate carboxy-terminal processing. Proteins that are involved in processing Ras, or in regulating its activity, e.g., by accelerating guanine nucleotide hydrolysis or exchange, have been largely conserved in evolution (for review, see Wigler 1993)
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Mesophilic-hydrothermal-thermophilic (M-H-T) digestion of green corn straw
No full textMesophilic-hydrothermal (80-160 degrees C, 30 min)-thermophilic (M-H-T) digestion and control tests of mesophilic (M), thermophilic (T), hydrothermal-mesophilic (H-M), and mesophilic-thermophilic digestion (M-T) of green corn straw were conducted for a 20-day fermentation period. The results indicate that M-H-T is an efficient method to improve methane production. A maximum methane yield of 371.74 mL/g volatile solid was obtained by the M (3 days)-H (140 degrees C)-T (17 days) process, which was 20.44%, 16.55%, 31.44%, and 14.31% higher than the yields of the M, T, 140-M, and M-T processes. The enhanced methane production was attributed to (1) the improved hemicellulose degradation and lignin disorganization; (2) prevention of the degradation of soluble sugar, easily hydrolyzed hemicellulose and cellulose into furfural and methylfurfural; and (3) lack of formation of Maillard reaction products during initial hydrothermal treatment. (C) 2015 Elsevier Ltd. All rights reserved
Contribution of Information and Communication Technology (ICT) in Country’S H-Index
No full textThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear.Cite as:
FARHADI, M., SALEHI, H., EMBI, M. A., FOOLADI, M., FARHADI, H., AGHAEI CHADEGANI, A., & ALE EBRAHIM, N. (2013). Contribution of Information and Communication Technology (ICT) in Country’S H-Index. Journal of Theoretical and Applied Information Technology, 57(1), 122-127
Lah–Ribarič type inequalities for (h, g; m)-convex functions
No full textRecently introduced new class of (h, g; m)-convex functions unifies a certain range of convexity, thus allowing the generalizations of know results. In this paper we prove Lah–Ribarič type inequalities for (h, g; m)-convex functions from which we obtain inequalities of Hermite–Hadamard, Fejér, Giaccardi, Popoviciu and Petrović. © 2021, The Author(s) under exclusive licence to The Royal Academy of Sciences, Madrid
Mrs. H. M. Evers
No full textNewspaper Article - 'Mrs. H. M. Evers' - Mrs. Evers hopes she can learn much about the living conditions here and the possibilities for the Dutch settlers.Alberta Women's Institutes; AWI CollectionMRS. H. M. EVERS
I bring out his capital immediately
and until such time as their capital
is released things are quite
difficult. "' There are very few
provinces in Canada that will supply
the Dutch settlers with a loan",
Mr. Jensma stated.
On her arrival here Mrs. Evers
i was astounded at the unusua1.
building of the city and the large
• ields of wheat. " Of course we have
wheat too, but ours is only a small
country so we have to be very
economical and not spend out
land too freely". The buildings are
much taller and narrower, especially
in the cities. Wood is very
expensive so most of the homes are
built of brick and concrete with
corrugated steel and tile roofs.
Give True Picture
In her travels across the country
Mrs. Evers hopes she can lenrn
much about the living conditions
here and the possibilities for the
Dutch settlers so when she re-
| turns to her homeland she will b- i
able to give the women of Holland
all the information possible and
prepare them for their great adventure.
Mrs. Evers and her family reside
on a 150 acre farm in the
northern part of the country. Her
daughter Tjaakje is a teacher in
home economics and her son.
Luken, works on the farm.
Besides serving on the immigration
board she is a member of the
international board of the YWCA;
the international Council of Women:
international corporation of
Dutch Country Wives: the international
organization of the Associated
Country Women of thr
World: and a member of the Women's
Institutes.
She will leave on Tuesday for
Toronto, where she will be met by
Mr. W. Blome. who is with the
Netherlands Immigration Board
in Ottawa.
A doctor declares the British
people are taking 10.000,000 aspirin
tablets a day
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