Search Results - (Author, Cooperation:F. Aziz)

2018-04-07

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-10-10

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2016-01-15

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; *Fossils ; History, Ancient ; *Hominidae ; Human Migration/history ; Humans ; Indonesia ; Tool Use Behavior

2018-09-14

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-05-16

BMJ Publishing

2044-6055

Medicine

Open access, Mental health

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The islands of Wallacea, located between the Southeast Asian (Sunda) and Australian (Sahul) continental areas, offer unique potential for the study of evolution and cultural change. Located east of Java and Bali, which were periodically connected to the Asian mainland, the Wallacean islands ...

Electronic Resource

0039-9140

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1617-4623

Springer Online Journal Archives 1860-2000

Biology

Summary Drosophila melanogaster males were irradiated at various stages of pre-imaginal development, and mutation rates were compared between first broods of different age groups, and between successive broods in the same age group. The findings were correlated with observations on germ cell development in the larval and pupal testis. Sensitivity to the mutagenic effect of X-rays is low in all premeiotic stages. It increases suddenly and dramatically with the onset of meiosis, remains stationary through meiosis, and subsequently increases again up to a peak in the late spermatid stage when transformation into morphologically mature spermatozoa is taking place. This stage provides sperm for the first brood from males treated at about the middle of the pupal period, and mutation rate for a given dose of X-rays is here about 4 times as high as in mature sperm and about 1 1/2 times as high as during meiosis. Subsequently, mutation rate drops again gradually to the level characteristic for mature sperm. Germinal selection cannot account for any of these changes; but it may be the main cause for the slight increase in response which occurs during spermatogonial development.

Electronic Resource

1617-4623

Springer Online Journal Archives 1860-2000

Biology

Summary x-rayed adult males ofDrosophila melanogaster were left with untreated females from 2 to 3 days after which the males were discarded. Sex-linked recessive lethals and translocations were scored in progeny produced during the first 2 or 3 days following irradiation, and after storage of the spermatozoa in the females for 6 days. The results obtained show that the frequencies of sex-linked lethals and of translocation involving the two large autosomes and the x-chromosome were unchanged by storage. In experiments in which Y, 2, 3 translocations were scored both the 2–3, and the Y translocations showed a slight increase. These experiments show that the strong storage effect on translocations produced by certain alkylating agents is peculiar to chromosomes treated by these chemicals.

Electronic Resource

1573-5036

anthesis ; layered soil ; nutrient concentrations ; nutrient uptake ; shoot:root ratios

Springer Online Journal Archives 1860-2000

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract The effect of soil layering on the growth and nutrient content of wheat shoots and roots was studied. PVC containers (120 cm long and 25 cm inside diameter) were filled with layers of loam and loamy sand. Both roots and shoots dry weight increased as the thickness of loam layer increased. The root:shoot ratios decreased throughout the growing season. The N, P and K content of the shoots peaked at two weeks before anthesis, while shoot dry weight peaked at anthesis. The ranges of shoot content of N, P and K at anthesis for the different treatments were 6–25, 8–25 and 5–25% of the total plant nutrients, respectively. Late in the season the translocation rate of nutrients from the shoots to the seeds were in the following order N〉P〉K.

Electronic Resource

0730-2312

IL-3-dependent FDC-P1 cells ; histone H4 gene ; cell cycle control ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Chemistry and Pharmacology

Medicine

To evaluate transcriptional mechanisms during cytokine induction of myeloid progenitor cell proliferation, we examined the expression and activity of transcription factors that control cell cycle-dependent histone genes in interleukin-3 (IL-3)-dependent FDC-P1 cells. Histone genes are transcriptionally upregulated in response to a series of cellular regulatory signals that mediate competency for cell cycle progression at the G1/S-phase transition. We therefore focused on factors that are functionally related to activity of the principal cell cycle progression at the G1/S-phase transition. We therefore focused on factors that are functionally related to activity of the principal cell cycle regulatory element of the histone H4 promoter:CDC2, cyclin A, as well as RB-and IRF-related proteins. Comparisons were made with activities of ubiquitous transcription factors that influence a broad spectrum of promoters independent of proliferation or expression of tissue-specific phenotypic properties. Northern blot analysis indicates that cellular levels of cyclin A and CDC2 mRNAs increase when DNA synthesis and H4 gene expression are initiated, supporting invoulvement in cell cycle progression. Using gel-shift assays, incorporating factor-specific antibody and oligonucleotide competition controls, we define three sequential periods following cytokine stimulation of FDC-P1 cells when selective upregulation of a subset of transcription factors is observed. In the initial period, the levels of SP1 and HiNF-P are moderately elevated; ATF, AP-1, and HiNF-M/IRF-2 are maximal during the second period; while E2F and HiNF-D, which contain cyclin A as a component, predominate during the third period, coinciding with maximal H4 gene expression and DNA synthesis. Differential regulation of H4 gene transcription factors following growth stimulation is consistent with a principal role of histone gene promoter elements in integrating cues from multiple signaling pathways that control cell cycle induction and progression. Regulation of transcription factors controlling histone gene promoter activity within the context of a staged cascade of responsiveness to cyclins and other physiological mediators of proliferation in FDC-P1 cells provides a paradigm for experimentally addressing interdependent cell cycle and cell growth parameters that are operative in hematopoietic stem cells. © 1995 Wiley-Liss, Inc.

9 Ill.

Electronic Resource