An involution on \beta(1,0)-trees

In [Decompositions and statistics for \beta(1,0)-trees and nonseparable permutations, Advances Appl. Math. 42 (2009) 313--328] we introduced an involution, h, on \beta(1,0)-trees. We neglected, however, to prove that h indeed is an involution. In this note we provide the missing proof. We also refine an equidistribution result given in the same paper.Comment: arXiv admin note: text overlap with arXiv:0801.403

The Möbius function of separable and decomposable permutations

We give a recursive formula for the Moebius function of an interval $[\sigma,\pi]$ in the poset of permutations ordered by pattern containment in the case where $\pi$ is a decomposable permutation, that is, consists of two blocks where the first one contains all the letters 1, 2, ..., k for some k. This leads to many special cases of more explicit formulas. It also gives rise to a computationally efficient formula for the Moebius function in the case where $\sigma$ and $\pi$ are separable permutations. A permutation is separable if it can be generated from the permutation 1 by successive sums and skew sums or, equivalently, if it avoids the patterns 2413 and 3142. A consequence of the formula is that the Moebius function of such an interval $[\sigma,\pi]$ is bounded by the number of occurrences of $\sigma$ as a pattern in $\pi$. We also show that for any separable permutation $\pi$ the Moebius function of $(1,\pi)$ is either 0, 1 or -1

Stem cells: cell differentiation and novel therapies

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenStem cells are unusual with regard to their capability of both self-renewal and differentiation into specialized cells. Best known are the hematopoietic stem cells which have been used in cell replacement therapy for many years. Recently, research on both embryonic and adult stem cells has offered new hope of cell replacement therapy to treat various diseases. Here we review the properties of both embryonic and adult stem cells as well as recent experiments on the therapeutic use of such cells. Although stem cells offer promising solutions for medical treatment, many difficulties need to be overcome before laboratory results can be moved to the bedside.Stofnfrumur búa yfir þeim áhugaverða eiginleika að geta endurnýjað og viðhaldið sjálfum sér en einnig myndað sérhæfðar frumur með skiptingu. Best þekktu stofnfrumurnar eru blóðmyndandi stofnfrumur en þær hafa verið notaðar í læknisfræðilegum tilgangi í fjölda ára til endurnýjunar á blóðfrumum sjúklinga. Nýlegar rannsóknir á stofnfrumum úr fósturvísum og stofnfrumum sem fundist hafa í ýmsum vefjum manna og dýra hafa vakið vonir um að unnt verði að nota þessar gerðir stofnfruma í svipuðum tilgangi. Í þessari yfirlitsgrein verða eiginleikar stofnfruma ræddir og fjallað um nýlegar tilraunir til að nýta þær í meðferð sjúkdóma. Ljóst er að enn er mörgum spurningum ósvarað varðandi notkun stofnfruma til lækninga

SentAlign: Accurate and Scalable Sentence Alignment

We present SentAlign, an accurate sentence alignment tool designed to handle very large parallel document pairs. Given user-defined parameters, the alignment algorithm evaluates all possible alignment paths in fairly large documents of thousands of sentences and uses a divide-and-conquer approach to align documents containing tens of thousands of sentences. The scoring function is based on LaBSE bilingual sentence representations. SentAlign outperforms five other sentence alignment tools when evaluated on two different evaluation sets, German-French and English-Icelandic, and on a downstream machine translation task.Comment: EMNLP 2023 System Demonstration pape

Kingella kingae ostemyelitis and septic arthritis in paediatric patients. Six cases from the Department of Pediatrics, National University Hospital of Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenKingella kingae (K. kingae) is a gram negative rod most often associated with septic arthritis and osteomyelitis in children. Infections caused by K. kingae had not been reported in Iceland when six cases were diagnosed at the Pediatric Department at the National University Hospital of Iceland. In this report we describe those cases and review the literature.Bakterían Kingella kingae (K. kingae) er gram neikvæður stafur sem getur valdið liða- og beinasýkingum í börnum. Árið 1995 greindist fyrsta sýkingin af völdum K. kingae hér á landi og í kjölfarið greindust fimm tilfelli á rúmu einu ári og eitt tilfelli fjórum árum síðar. Öll tilfellin greindust á Barnaspítala Hringsins. Í þessari grein munum við lýsa tilfellunum og gera grein fyrir sýkingavaldinum

Negative pressure wound therapy in Iceland - indication and outcome

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/Open Allur texti - Full textINTRODUCTION: Negative pressure wound therapy (NPWT) is a recent therapeutic option in wound healing, where a vacuum source is used to create sub-atmospheric pressure in the wound bed with airtight dressings. The aims were to study the indications for the use of NPWT in a whole country and evaluate the outcome of treatment. MATERIAL AND METHODS: This was a retrospective study that included all patients that were treated with NPWT in Iceland between January and December 2008. Information on indication, duration and outcome of treatment was collected from patient charts. Factors that are known to affect wound healing, such as diabetes, smoking and age, were also registered. RESULTS: During the 12 month study period a total of 65 NPWT-treatments were given to 56 patients; 35 (63%) males and 21 (37%) females, with an average age of 62 yrs (range; 8 - 93). The indications for treatment were: wound infection (40%), promotion of wound healing (42%) and keeping cavities open (19%). The lower limbs (26%) and chest area (25%) were the most common sites for treatment. Six patients died during the treatment period, none of them due to complications related to NPWT, and these patients were excluded from analysis of wound healing. In the other 59 treatments, 40 wounds (68%) healed successfully, but healing was incomplete in 19. Treatment related complications were recorded in 19 (32%) cases; wound pain (12%) and skin problems (11%) being the most common ones. CONCLUSION: NPWT has been used considerably in Iceland, especially for infected surgical wounds and chronic wounds. In two thirds of cases a complete wound healing was achieved, which must be regarded as a favorable outcome.Inngangur: Sárasogsmeðferð (negative pressure wound therapy, NPWT) er nýjung í sárameðferð þar sem undirþrýstingur er myndaður staðbundið í sárbeðnum með loftþéttum umbúðum og sogtæki. Tilgangur rannsóknarinnar var að kanna ábendingar og árangur sárasogsmeðferðar hjá heilli þjóð, en slík rannsókn hefur ekki verið gerð áður. Efniviður og aðferðir: Afturskyggn rannsókn sem náði til allra sjúklinga, bæði á sjúkrahúsum og utan, sem fengu sárasogsmeðferð á Íslandi frá janúar til desember 2008. Ábending, tímalengd og árangur meðferðar voru skráð úr sjúkraskrám. Einnig var metinn gróandi sára og þættir sem geta haft áhrif á gróanda, eins og sykursýki, reykingar og aldur. Niðurstöður: Alls fengu 56 sjúklingar 65 sárasogsmeðferðir. Karlar voru 63% og meðalaldur 62 ár (bil 8-93 ár). Meðferð var veitt á sjúkrahúsi í 85% tilfella, oftast á æða- og brjóstholsskurðdeildum. Algengustu ábendingar fyrir meðferð voru sýking í sári (40%), örvun gróanda (42%) og viðhald opinna holrúma (19%). Flest sárin voru á neðri útlimum (26%) og brjóstkassa (25%). Sex sjúklingar létust vegna undirliggjandi sjúkdóma og voru þeir ekki teknir með við mat á gróanda sára. Af 59 meðferðum náðist fullur gróandi sára í 40 (68%) en ófullkominn gróandi í 19 (32%). Fylgikvillar tengdir meðferð voru skráðir í 19 (32%) tilfellum og voru verkir (12%) og húðvandamál (11%) algengust. Ályktanir: Sárasogsmeðferð er töluvert notuð á Íslandi, sérstaklega við sýkt skurðsár og langvinn sár. Í tveimur þriðju tilfella náðist fullur gróandi sára sem telst góður árangur