57,510 research outputs found
Hypertension in kidney stone patients.
No full textThe prevalence of arterial hypertension (HT) was investigated in 258 patients (171 m, 87 f, 22-68 years) with a history of primary stone disease. HT was detected in 64 patients (24.8%), with no difference between males (25.7%) and females (23.0%). The prevalence of HT by age was very similar to that of a general population, especially in the calcium stone group. The discriminant analysis demonstrated that the composition of stones, other than the age and body weight of the patients, were the main factors associated with HT. As far as the different kind of stone is concerned, the prevalence of HT was higher in patients with uric acid (17/37, 45.9%) and struvite stones (11/27, 40.7%) than in calcium stone formers (35/188, 18.6%) (chi 2 16.31, p < 0.001). The prevalence of hypercalciuria was higher in the calcium stone group than in uric acid or struvite stone patients (36.4 vs. 9.7 vs. 13.7%; chi 2 10.35, p < 0.01). Furthermore, the hypercalciuria showed a trend to be more prevalent in the untreated (47.0%) than in the treated (31.2%) hypertensives, or normotensives (35.1%). Uric acid stone formers were older, heavier and with higher triglycerides and uric acid plasma levels than calcium or struvite patients. Also the struvite stone formers were older than the calcium stone ones. Our data suggest that the prevalence of HT in kidney stone patients and particularly in calcium stone formers is similar to that of a general population. The role of hypercalciuria as the link for HT-urolithiasis association seems quite uncertain. Struvite and uric acid stone formers have higher risk for HT than calcium stone formers, probably due to the old age or to the associated metabolic abnormalities
John M. Stone Papers
No full textIn a series of letters, Mrs. E. V. English writes to Stone regarding her son, S. M. Montie English. She asks Stone to look after, worries when it is clear that his tuition payment has not arrived, and lets Stone know that her son is with her sick with a cold. December 31, 1899, January 4, 1900, January 5, 1900, March 3, 1900 (two letters)https://scholarsjunction.msstate.edu/ua-msu-founders-documents/1284/thumbnail.jp
Archeometric Investigation of the Stone Tools of the Vatya Culture (Pest County, Hungary)
No full textWith the analysis of the middle Bronze Age (2000–1350 BC) Vatya culture findings in Pest county (Central Hungary) comprising of more than 400 polished stone tools and instrument tools this is the first archaeometric study with such scale in Hungary. In order to characterize petrographically the raw-material of the stone tools macroscopic and microscopic stone analyses were made together with mineralogical and geochemical analyses. In the course of the work a new digital database the Archaeometric Stone Tool Database was established. Based on the results, the material of the instrument stones is mainly sandstone and quartzite that were easy to collect from their source areas. Local volcanics, mostly amphibole containing andesite variations dominated among the material of the polished stone tools. Ophiolites (metamorphic basic rocks, serpentinized basic and ultrabasic rocks) were the raw-material of stone axes that indicate either more distant travels for raw-material or exchange import
STONE AND STONE ARCH
No full textDiplomsko delo zajema sklop poglavij o naravnem kamnu in gradnji s tem naravnim materialom. Prvi del govori o njegovem pridobivanju, oblikovanju, tehničnih lastnostih in obdelavi kamna – splošno, v drugem delu pa o projektiranju in obdelavi kamna v kamnoseški obrti. Gradnja s kamnom, natančneje gradnja kamnitega loka, ki je bil do nedavnega nepogrešljiv element v arhitekturi in gradbeništvu je prikazana v tretjem delu. Na primeru največjega železniškega ločnega mostu s klesanega kamna – Solkanskega mostu, smo naredili grafično analizo loka s konstantnim prerezom in preverili notranje napetosti na posameznih delih ločne konstrukcije.The purpose thesis comprises a set of chapters on the natural stone and on the construction using the material. The first part describes the process of its exploitation, formation, technical characteristics and stone handling in general. The second part provides information on the planning and stone handling in stonecutting. The third part presents the construction using stone, more precisely construction of a stone arch, which has been an indespensable element in architecture and construction until recently. The construction element is described on an example of the largest railway bridge - the Solkan bridge, where we made a graphical analysis with constant cross section and checked the inner forces of individual section of the arch construction
The maker not the tool: The cognitive significance of great ape manual skills
No full textTool-use by chimpanzees has attracted disproportionate attention among primatologists, because of an understandable wish to understand the evolutionary origins of hominin tool use. In archaeology and paleoanthropology, a focus on made-objects is inevitable: there is nothing else to study. However, it is evidently object-directed manual skills, enabling the objects to be made, that are critical in understanding the evolutionary origins of stone-tool manufacture. In this chapter I review object-directed manual skills in living great apes, making comparison where possible with hominin abilities that can be inferred from the archaeological record. To this end, ‘translations’ of terminology between the research traditions are offered. Much of the evidence comes from observation of apes gathering plants that present physical problems for handling and consumption, in addition to the more patchy data from tool use in captivity and the field. The living great apes, like ourselves, build up novel hierarchical structures involving regular sequences of elementary actions, showing co-ordinated manual role differentiation, in modular organizations with the option of iterating subroutines. Further, great apes appear able to use imitation of skilled practitioners as one source of information for this process, implying some ability to ‘see’ below the surface level of action and understand the motor planning of other individual; however, that process does not necessarily involve understanding cause-and-effect or the intentions of other individuals. Finally I consider whether a living non-human ape could effectively knap stone, and if not, what competence is lacking.Postprin
Tacit knowledge, learning and expertise in dry stone walling
No full textThis is a detailed study of learning in the context of dry stone walling. It examines
what happens in the learning situation. The aim of this work was:
'To understand the nature of expertise in dry stone walling, how it is understood
by those practising the craft, and how it is transmitted to others'.
The main research questions were, therefore:
What happens when dry stone wallers are learning their craft?
How do they acquire expertise in dry stone walling?
How is this learning communicated?
This process necessitated developing a way of engaging with the practitioners,
eliciting descriptive data about what they were doing, and why they were doing it,
through interviews (or conversations) with both individuals and groups, whilst
they practiced their skill. Twenty three wailers were interviewed as they worked,
building walls.
The material obtained was analysed under seven different themes:
'Knowing how'
The use of tacit knowledge or intuition
'Flow'
Constant decision making, reflection and learning from mistakes
Individual and subjective variations and experiences
The relevance of emotion
The use of 'rules of thumb' or maxims.
Learning walling does not fit simply into any of the seven themes. It is
contextualised, complex and individual. It demonstrates tacit knowledge and
intuition. It involves emotion, sometimes consciously, sometimes not. It involves
memory, problem solving, and learning from mistakes, and reflection. Maxims or
'rules of thumb' were a key element in the learning process at all stages. Linear
stages of learning were not evidenced. Deep understanding of the practice is
evidenced, and the wider learning and teaching implications are explored
Prototyping Stereotomic Assemblies: Stone Polysphere
No full textThe paper describes the parametric design, fabrication and construction of the Stone PolySphere, an installation that investigates the potential of digital fabrication applied to the stone industry. It is a lithic sphere with a diameter of 1.4 m, composed by a massive hemisphere below and a stereotomic hemisphere above. The prototype ideally summarizes, in a single object, the two big trends in stone architecture: the megaliths (below) and the stereotomic assemblies (above). The upper part is a micro-architecture that represents a domed space. The research also shows a new workflow for the realisation of non-reciprocal stereotomic geodesic assemblies, in which are used complex holed voussoirs generated by means of simple morphing operations and recursive subdivisions. The fabrication of the voussoirs consists in milling of several layers of stones glued together. The results are critically discussed, and the implications of the parametric design process are pointed out
Controlling crystallization damage by the use of salt inhibitors on Malta's limestone
No full textParallel text in Spanish and EnglishThe main building stone in the Maltese Islands is the Globigerina Limestone, of which the Lower member is commonly used. This occurs in two types, the durable franka and the more easily weathered soll. Two types of fresh franka (bajda (white) and safra (yellow)), as well as fresh soll stone blocks, were obtained, based on the identification by quarry owners. Their designation was confirmed by geochemistry. Physical and mechanical properties of the three were investigated, including uniaxial compressive strength, water absorption by capillarity, permeability and porosimetry. Porosimetry results confirmed outcomes of previous research work. Soll was found to have a lower overall porosity, but a high percentage of small pores with practically no large pores. Some of the tested stones were then treated with a non-toxic phospho- organic compound containing carboxylic moieties as a salt inhibitor and the corresponding non-phosphorylated compound.peer-reviewe
Surface consolidation of natural stone materials using microbial induced calcite precipitation
No full textNatural stone tends to have high porosity and is easily eroded by environmental weathering. In recent years, industrialisation has caused an acceleration of stone decay due to the toxic by-products of industry breaking down the stones’ constituents.
This paper investigates the effect of microbial induced calcite precipitation as a natural treatment for the surface preservation and restoration of historic buildings. Sporosarcina pasteurii has been proven as a bacterium that can perform microbial induced calcite precipitation (MICP) effectively in extreme conditions making it the preferred bacterium for the MICP process within this study.
The surface treatment experiment was analysed by measuring the mass increase and surface changes using scanning electron microscopy.
The surface treatments showed a noticeable mass increase and observable deposition when viewed using a SEM microscope. Bio cementation of loose sand particles was observed and the degree of cementation was determined using a Mohs hardness test
First observation of Bs → J/ψf0(980) decays
No full textUsing data collected with the LHCb detector in proton–proton collisions at a centre-of-mass energy of 7 TeV, the hadronic decay is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the system. Using a fit to the π+π− mass spectrum with interfering resonances gives . In the interval ±90 MeV around 980 MeV, corresponding to approximately two full f0 widths we also find , where in both cases the uncertainties are statistical and systematic, respectively
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