47 research outputs found

    A generalized method for multiple robotic manipulator programming applied to vertical-up welding

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    The application is described of a weld programming algorithm for vertical-up welding, which is frequently desired for variable polarity plasma arc welding (VPPAW). The Basic algorithm performs three tasks simultaneously: control of the robotic mechanism so that proper torch motion is achieved while minimizing the sum-of-squares of joint displacement; control of the torch while the part is maintained in a desirable orientation; and control of the wire feed mechanism location with respect to the moving welding torch. Also presented is a modification of this algorithm which permits it to be used for vertical-up welding. The details of this modification are discussed and simulation examples are provided for illustration and verification

    Epidemiology of Spinal Cord Injury in Iceland from 1975 to 2014

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    Efst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinnInngangur: Mænuskaði er meðal alvarlegustu afleiðinga slysa og þar sem ekki hefur tekist að finna lækningu við mænuskaða hefur áhersla verið lögð á forvarnarstarf. Nýgengi mænuskaða er breytilegt milli landa og ýmsar breytingar hafa orðið á faraldsfræði mænuskaða í áranna rás. Markmið þessarar rannsóknar var að kanna faraldsfræði mænuskaða af völdum slysa á Íslandi og leita áhættuþátta sem nýta mætti í forvarnarskyni. Efniviður og aðferðir: Farið var afturskyggnt yfir sjúkraskrár allra sem greindust með mænuskaða samkvæmt ICD-9/ICD-10 á Landspítala á árunum 1975-2014. Upplýsinga var aflað um nýgengi, aldur, kynjaskiptingu og orsakir. Notaður var skalinn American Spinal Injury Association Impairment Scale (AIS) við mat á alvarleika mænuskaða. Niðurstöður: Á rannsóknartímabilinu hlutu 233 einstaklingar mænuskaða af völdum áverka, eða 26 á hverja milljón íbúa á ári að meðaltali. Karlmenn voru 73% og meðalaldurinn 39 ár. Umferðarslys voru algengasta orsök mænuskaða. Oftast var um að ræða bílveltur í dreifbýli og í að minnsta kosti helmingi tilfella voru bílbelti ekki notuð. Fall var næstalgengasta orsök mænuskaða en í þeim orsakaflokki var meðalaldurinn hæstur. Reiðmennsku- og vetraríþróttaslys voru algengust íþrótta- og tómstundaslysa. Í um þriðjungi mænuskaðatilfella var um að ræða alskaða á mænu. Við útskrift höfðu 9% náð fullum bata. Ályktun: Mikilvægt er að efla enn frekar forvarnir og áróður í tengslum við bílbeltanotkun og öryggi á vegum landsins. Einnig þarf að leita leiða til að fækka mænuskaðatilfellum vegna falls, svo sem með því að kanna nánar ástæður falla hjá eldra fólki og bæta öryggisreglur á vinnustöðum. Hugsanlega mætti fækka íþrótta- og tómstundaslysum með forvarnaraðgerðum og bættum öryggisbúnaði.Introduction: Traumatic spinal cord injury (TSCI) is serious and often has long-term consequences. Since no cure has been found the emphasis has been on preventive measures. The incidence of TSCI varies between countries and the epidemiology has been changing. The aim of this study was to gather epidemiological data on patients with TSCI in Iceland and search for risk factors. Material and methods: Hospital records of everyone diagnosed with TSCI in 1975-2014 admitted to Landspitali University Hospital were reviewed and information gathered on incidence, age, gender and causes of injury. The American Spinal Injury Association Impairment Scale (AIS) was used to assess the extent of TSCI. Results: A total of 233 patients were diagnosed with TSCI during the study period or 26 per million annually on average. Males were 73% and the mean age was 39 years. Traffic accidents were the most common cause of TSCI. The majority were car rollovers in rural areas. Around 50% did not use a seatbelt. The second most common cause of TSCI were falls. The most common sport/leisure accidents were those related to horseback-riding and winter sports. A third of patients had a complete SCI. At discharge 9% had gained full recovery. Conclusions: Safe roads and good traffic culture are essential factors in the prevention of serious traffic accidents. Strict safety regulations in the work place and an investigation of causes of falls amongst the elderly could decrease SCIs due to falls. Further preventive measures and protective equipment could possibly be of use in sport- or leisure-related activities

    Intensive care patients with influenza A (H1N1) infection in Iceland 2009

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    Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn Skoða/Opna(view/open)BACKGROUND: We describe the main characteristics of patients that required intensive care due to the influenza (H1N1) outbrake in 2009. METHODS: Retrospective and prospective analysis of medical records from patients admitted to ICU with positive RT-PCR for (H1N1). RESULTS: During a six week period in the fall of 2009, 16 patients were admitted to intensive care in Iceland with confirmed H1N1 infection. Mean age was 48 years (range 1-81). Most patients were considered quite healthy but the majority had risk factors such as smoking, obesity or hypertension. All but one had fever, cough, dyspnea and bilateral infiltrates on chest x-ray and developed any organ failures (mean SOFA score 7). 12 needed mechanical ventilation and two extra corporeal membrane oxygenation (ECMO). Mean APACHE II score was 20. No patient died in the ICU but one elderly patient with multiple underlying diseases died a few days after being discharged from the ICU. CONCLUSIONS: (1) The incidence of severe influenza A (H1N1) that leads to ICU admission appears to be high in Iceland. (2) Many patients developed acute respiratory distress syndrome in addition to other organ failures, and required additional measures for oxygenation such as prone position, nitric oxide inhalation and ECMO. (3) 28 day mortality was low. (4) This study will aid in future outbreak planning in Iceland. Key words: influenza A, pneumonia, multiple organ failure, death rate, intensive care, ventilator therapy, ECMO.Tilgangur: Að lýsa helstu einkennum og afdrifum þeirra sem lögðust inn á gjörgæsludeildir á Íslandi vegna inflúensusýkingar af A stofni (H1N1) haustið 2009. Aðferðir: Aflað var upplýsinga um sjúklinga sem lögðust inn á gjörgæsludeildir á Íslandi með staðfesta H1N1 2009 sýkingu. Niðurstöður: 16 sjúklingar lögðust inn á gjörgæsludeildir vegna inflúensu A (H1N1) sýkingar, meðalaldur 48 ár (1-81). Flestir töldust vera tiltölulega frískir fyrir, en 13 höfðu þó sögu um reykingar, offitu eða háþrýsting. 15 höfðu hita, hósta, öndunarþyngsli og dreifðar íferðir í báðum lungum á lungnamynd og margir fengu fjöllíffærabilun. Allir fengu veirulyf og 12 voru meðhöndlaðir í öndunarvél, þar af tveir einnig í hjarta- og lungnavél. Enginn sjúklingur lést á gjörgæsludeild, en einn fjölveikur aldraður sjúklingur lést síðar á legudeild. Ályktanir: (1) Tíðni alvarlegra sjúkdómseinkenna af völdum inflúensu A (H1N1) sem leiða til gjörgæslumeðferðar er há á Íslandi. (2) Þessir sjúklingar fá flestir, auk annarra líffæratruflana, mjög alvarlega öndunarbilun sem oft lætur ekki undan hefðbundinni öndunarvélameðferð. (3) Árangur meðferðar á íslenskum gjörgæsludeildum hefur verið góður. (4) Niðurstöður þessarar rannsóknar geta nýst yfirvöldum við mat á meðferðarmöguleikum og fyrirbyggjandi aðgerðum gegn þessum lífshættulega sjúkdómi

    The external benefits of higher education

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    The private market benefits of education are widely studied at the micro level, although the magnitude of their macroeconomic impact is disputed. However, there are additional benefits of education, which are less well understood. In this paper the macroeconomic effects of external benefits of higher education are estimated using the “micro-to-macro” simulation approach. Two types of externalities are explored: technology spillovers and productivity spillovers in the labour market. These links are illustrated and the results suggest they could be very large. However, this is qualified by the dearth of microeconomic evidence, for which we hope to encourage further work

    Density Matrix Functional Calculations for Matter in Strong Magnetic Fields: I. Atomic Properties

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    We report on a numerical study of the density matrix functional introduced by Lieb, Solovej and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes {\em exactly} the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge ZZ and the electron number NN tend to infinity with N/ZN/Z fixed, and the magnetic field BB tends to infinity in such a way that B/Z4/3B/Z^{4/3}\to\infty. We have calculated electronic density profiles and ground state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained by other methods. For iron at B=1012B=10^{12} G the ground state energy differs by less than 2 \% from the Hartree-Fock value. We have also studied the maximal negative ionization of heavy atoms in this model at various field strengths. In contrast to Thomas-Fermi type theories atoms can bind excess negative charge in the density matrix model. For iron at B=1012B=10^{12} G the maximal excess charge in this model corresponds to about one electron.Comment: Revtex, 13 pages with 6 eps figures include

    How much does a single graduation cohort from further education colleges contribute to an open regional economy?

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    This paper combines elements of growth accounting and numerical general equilibrium analysis to produce an alternative micro-to-macro modelling approach. This is used to evaluate the macroeconomic impact on the Scottish economy of the human capital generated by a single graduation cohort from further education colleges. The macroeconomic impact is found to be significant and larger than growth accounting would suggest due to the associated endogenous investment, employment and competitiveness effects. From a policy perspective this identifies the importance of the conventional teaching role of education institutions and the key function played by further education colleges in this process

    A genome-wide meta-analysis yields 46 new loci associating with biomarkers of iron homeostasis

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    Bell et al. report 46 new loci associated with biomarkers of iron homeostasis, including ferritin levels, iron binding capacity, and iron saturation, in the Icelandic, Danish and UK populations. The associated loci point to new iron-regulating proteins and important genetic differences between men and women

    Common variants near CAV1 and CAV2 are associated with primary openangle glaucoma.

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    l e t t e r s We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in 1,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q31 (rs4236601[A], odds ratio (OR) = 1.36, P = 5.0 × 10 −10 ). We then replicated the association in sample sets of 2,175 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = 1.18, P = 0.0015) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.0021). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG. Glaucoma is the leading cause of irreversible blindness worldwide, affecting approximately 70 million people 1 . It is a chronic degenerative optic neuropathy with progressive loss of retinal ganglion cells and axons resulting in a corresponding thinning of the neuroretinal rim of the optic nerve and a characteristic visual field defect. It is distinct from other forms of optic neuropathy in that the neuro retinal rim of the optic nerve retains its normal pink color as it becomes progressively thinner, leading to an enlarged opticnerve cup. POAG is the most common form of glaucoma. Excluding rare primary juvenile glaucoma with age of onset between 10 and 35 years, POAG is arbitrarily divided into highpressure glaucoma (defined as ≥22 mmHg) and normalpressure glaucoma. POAG is thought to have a multifactorial etiology, with the main risk factors being age, elevated intraocular (IOP) pressure, family history, race, central corneal thickness (CCT), hypertension, diabetes and myopia. The familiality of POAG has been known for decades, and studies have revealed three to ninefold greater risk of POAG in firstdegree relatives of POAG cases than in the population in general 2 . Common variants near CAV1 and CAV2 are associated with primary openangle glaucom
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