1,357,669 research outputs found
Adriaan Blaauw, 1914-2010
No full textIn the last issue of The Messenger (142, p. 51) only a brief obituary of Adriaan Blaauw, the second Director General of ESO, could be included at the time of going to press. There follow three tributes to Adriaan Blaauw: by Tim de Zeeuw, current ESO Director General; by his long-term colleague at the Kapteyn Institute, Stuart Pottasch; and by Raymond Wilson, who led the Optics Group during his tenure as Director General
Adriaan Blaauw, 1914-2010
No full textIn the last issue of The Messenger (142, p. 51) only a brief obituary of Adriaan Blaauw, the second Director General of ESO, could be included at the time of going to press. There follow three tributes to Adriaan Blaauw: by Tim de Zeeuw, current ESO Director General; by his long-term colleague at the Kapteyn Institute, Stuart Pottasch; and by Raymond Wilson, who led the Optics Group during his tenure as Director General
The Cheops mystery targeted with neutrons
No full textHow the ancient Egyptians managed to raise a seven million tonne pyramid in a time span of only twenty years remains a mystery. Every now and then discussions flare up as to how exactly the pyramids at Giza in Egypt were constructed. How could they cut stone without the necessary chisels? How did they manage to drag 2.5 million blocks of stone, each weighing several tons, as high as 140 metres above the desert? Or did they? Perhaps the ancient Egyptians were brilliant engineers who poured broken up limestone and cement into moulds to form made-to-measure? Cut or cast? That is the question which Dr Menno How the ancient Egyptians managed to raise a seven million tonne pyramid in a time span of only twenty years remains a mystery. Every now and then discussions flare up as to how exactly the pyramids at Giza in Egypt were constructed. How could they cut stone without the necessary chisels? How did they manage to drag 2.5 million blocks of stone, each weighing several tons, as high as 140 metres above the desert? Or did they? Perhaps the ancient Egyptians were brilliant engineers who poured broken up limestone and cement into moulds to form made-to-measure? Cut or cast? That is the question which Dr Menno Blaauw, head of Facilities & Services at the Reactor Institute Delft, subjected to the latest analysis techniques
Un gentilhomme paisible, le « Batave » Jacobus Blaauw (1759-1829).
No full textJacobus Blaauw has been a prominent Dutch diplomat, intensely tied with Dutch political circles, just after the Batavian Revolution in with he dealt, and, above all, in Paris, where he represented the Batavian Republic before its creation and during the principal years of its existence.
Suspected of having encouraged the Canoneers' Riots of Amsterdam (1793), Blaauw was asked to leave his functions by the French Directory, and then went to italy where he represented also the Batavian government, before, going back in Holland, to participate in the works and troubles of the first Dutch Assemblies. Back in Paris for confidential missions, he soon lost the confidence of his Dutch committants and, definitely, of the French Government, led by his friends Barras, Talleyrand and Bonaparte.
That didn't stop him from sustaining the power of the Consulate and Empire, to assume a fiscal function of the Ist Empire in th Netherlands, before requesting and getting a well deserved retreat in France, troubled by the dramatic end of the Empire he was an attentive witness of.
J. ALEXANDRE et M.R. PERRIN-CHEVRIER.Alexandre Jean, Perrin-Chevrier Marie-Rose. Un gentilhomme paisible, le « Batave » Jacobus Blaauw (1759-1829).. In: Annales historiques de la Révolution française, n°261, 1985. pp. 335-352
The functional significance of the skeletal muscle clock: Lessons from Bmal1 knockout models
No full textThe circadian oscillations of muscle genes are controlled either directly by the intrinsic muscle clock or by extrinsic factors, such as feeding, hormonal signals, or neural influences, which are in turn regulated by the central pacemaker, the suprachiasmatic nucleus of the hypothalamus. A unique feature of circadian rhythms in skeletal muscle is motor neuron-dependent contractile activity, which can affect the oscillation of a number of muscle genes independently of the muscle clock. The role of the intrinsic muscle clock has been investigated using different Bmal1 knockout (KO) models. A comparative analysis of these models reveals that the dramatic muscle wasting and premature aging caused by global conventional KO are not present in muscle-specific Bmal1 KO or in global Bmal1 KO induced in the adult, therefore must reflect the loss of Bmal1 function during development in non-muscle tissues. On the other hand, muscle-specific Bmal1 knockout causes impaired muscle glucose uptake and metabolism, supporting a major role of the muscle clock in anticipating the sleep-to-wake transition, when glucose becomes the predominant fuel for the skeletal muscle
ENABLING FACTORS FOR THE EXISTENCE OF WASTE PICKERS: A SYSTEMATIC REVIEW
No full textThe paper reports on a systematic review research process to determine the enabling factors for waste pickers to operate in the informal economy in South Africa. Twenty-eight South African journal articles, theses and position and policy papers were sourced and appraised. The results indicate that recognition of the waste pickers in the waste system is the most enabling factor for them to operate. The concept of recognition is analysed, described and explained as assisting waste pickers to become more visible, having a voice and to be validated
Happiness among first-year students at a comprehensive tertiary institution - an exploratory study
No full textThe 1970s saw a significant increase in the volume of research on individuals' subjective experience of well-being. The subjective well-being of university students has received less attention, however. Student well-being is important, given the widespread concern over the high dropout rates at institutions of higher learning in South Africa (Council of Higher Education, 2013; Van Zyl, 2010). The paper adds to the existing body of literature through an exposition on the possible influence of variables forthcoming from the literature, on the overall subjective well-being of first-year economics students at a comprehensive university. Variables that displayed a significant and positive contribution to subjective well-being were first-year and extended-degree students, the university being the institution of choice, feeling at home, knowing exactly how the university functions, and watching or participating in sport. Variables that were found to be significant with a negative contribution to subjective well-being levels were: worries about tests, studying less than 10 hours per week and, interestingly, living on campus
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The effects of Akt overexpression in normal and dystrophic skeletal muscle
No full textLengthening (eccentric) contractions are known to induce skeletal muscle damage. Skeletal muscles of the dystrophin-deficient mdx mouse are especially sensitive to damage caused by lengthening contractions. Mild protocols of lengthening contractions, that cause no force decrement in normal mouse muscles, were found to cause a marked reduction in the maximal force produced by mdx muscles. The altered response of mdx muscles is considered to be due to sarcolemmal fragility, since no difference in force deficit after lengthening contractions was detected between mdx and control skinned fibers. We have developed an in vivo model to quantify the susceptibility of mdx mice muscles to eccentric contractions and showed a marked force decrease in the gastrocnemius of these animals.
We generated a transgenic mouse in which an inducible constitutively active form of Akt1 can be expressed selectively in adult skeletal muscle. We found that activation of Akt is sufficient to induce rapid and functional skeletal muscle hypertrophy. We crossed mdx mice with Akt transgenic mice and show a clear protection against damage from lengthening contractions after 3 weeks of Akt activation. Surprisingly, this protection is not correlated to muscle hypertrophy and is independent on the mTOR-pathway since rapamycin-treatment doesn’t inhibit the protective effect of Akt.
Protection against damage occurs on the mofibrillar level, most likely mitigated by an increase of utrophin leading to a reinforced cytoskeleton
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