Three Partition Refinement Algorithms

We present improved partition refinement algorithms for three problems: lexicographic sorting, relational coarsest partition, and double lexical ordering. Our double lexical ordering algorithm uses a new, efficient method for unmerging two sorted sets

A max-flow approach to improved lower bounds for quadratic unconstrained binary optimization (QUBO)

AbstractThe “roof dual” of a QUBO (Quadratic Unconstrained Binary Optimization) problem has been introduced in [P.L. Hammer, P. Hansen, B. Simeone, Roof duality, complementation and persistency in quadratic 0–1 optimization, Mathematical Programming 28 (1984) 121–155]; it provides a bound to the optimum value, along with a polynomial test of the sharpness of this bound, and (due to a “persistency” result) it also determines the values of some of the variables at the optimum. In this paper we provide a graph-theoretic approach to provide bounds, which includes as a special case the roof dual bound, and show that these bounds can be computed in O(n3) time by using network flow techniques. We also obtain a decomposition theorem for quadratic pseudo-Boolean functions, improving the persistency result of [P.L. Hammer, P. Hansen, B. Simeone, Roof duality, complementation and persistency in quadratic 0–1 optimization, Mathematical Programming 28 (1984) 121–155]. Finally, we show that the proposed bounds (including roof duality) can be applied in an iterated way to obtain significantly better bounds. Computational experiments on problems up to thousands of variables are presented

Prepoznavanje faza koje sadrže Fe u mikrostrukturi livene legure AA6026 i njihova evolucija tokom postupka homogenizacije

The Fe-bearing intermetallic phases present in the as-cast AA6026 alloy and their evolution during homogenization treatments at 480-550°C were investigated using optical microscopy, SEM, and TEM techniques in combination with EDS analysis. In addition to the α-Al(Fe,Mn)Si phase with dendritic morphology, two types of plate-like Fe-bearing microconstituents were revealed in the microstructure of the as-cast alloy. The EDS microanalysis and electron diffraction showed that one set of platelets represented thin sections of α-Al(Fe,Mn)Si microconstituent. The other set of plate-like microconstituents was identified as a tetragonal, silicon-rich δ-Al4(Fe,Mn)Si2 phase. The formation of the δ-Al4(Fe,Mn)Si2 phase was attributed to the chemical composition of the alloy. During homogenization, the metastable δ-Al4(Fe,Mn)Si2 transformed into the α-Al(Fe,Mn)Si phase and fragmented. The dendritic α-Al(Fe,Mn)Si microconstituents underwent fragmentation. However, while the α-Al(Fe,Mn)Si microconstituents preserved a b.c.c. crystal lattice throughout the process, the product of the transformation of the δ-Al4(Fe,Mn)Si2 phase exhibited primitive cubic lattice.Ispitivanje prisustva faza koje sadrže Fe u mikrostrukturi livene legure AA6026, kao i njihova evolucija tokom postupaka homogenizacije na temperaturama od 480-550 °C, sprovedena su korišćenjem optičke mikroskopije, skenirajuće elektronske mikroskopije (SEM) i transmisione elektronske mikroskopije (TEM) u kombinaciji sa analizom EDS-a. Osim faze α-Al(Fe,Mn)Si sa dendritskom morfologijom, identifikovane su dve vrste pločastih mikrokonstituenata koji sadrže Fe u mikrostrukturi livene legure. EDS mikroanaliza i elektronska difrakcija pokazali su da jedan skup ploča predstavlja samo tanke sekcije mikrokonstituente α-Al(Fe,Mn)Si. Drugi skup pločastih mikrokonstituenata identifikovan je kao četvrtasta, silicijumom bogata faza δ-Al4 (Fe,Mn)Si2 . Formiranje faze δ-Al4 (Fe,Mn)Si2 povezano je sa hemijskim sastavom legure. Tokom homogenizacije, metastabilna faza δ-Al4 (Fe,Mn)Si2 transformisala se u fazu α-Al(Fe,Mn)Si i fragmentirala. Dendritski mikrokonstituenti α-Al(Fe,Mn)Si takođe su fragmentirali. Međutim, dok su mikrokonstituenti α-Al(Fe,Mn)Si sačuvali kubnu kristalnu rešetku tipa b.c.c. tokom procesa, proizvod transformacije faze δ-Al4 (Fe,Mn)Si2 pokazao je prostu kubnu rešetku

Some biomarkers of acute kidney injury are increased in pre-renal acute injury

Pre-renal acute kidney injury (AKI) is assumed to represent a physiological response to underperfusion. Its diagnosis is retrospective after a transient rise in plasma creatinine, usually associated with evidence of altered tubular transport, particularly that of sodium. In order to test whether pre-renal AKI is reversible because injury is less severe than that of sustained AKI, we measured urinary biomarkers of injury (cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), γ-glutamyl transpeptidase, IL-18, and kidney injury molecule-1 (KIM-1)) at 0, 12, and 24 h following ICU admission. A total of 529 patients were stratified into groups having no AKI, AKI with recovery by 24 h, recovery by 48 h, or the composite of AKI greater than 48 h or dialysis. Pre-renal AKI was identified in 61 patients as acute injury with recovery within 48 h and a fractional sodium excretion <1%. Biomarker concentrations significantly and progressively increased with the duration of AKI. After restricting the AKI recovery within the 48 h cohort to pre-renal AKI, this increase remained significant. The median concentration of KIM-1, cystatin C, and IL-18 were significantly greater in pre-renal AKI compared with no-AKI, while NGAL and γ-glutamyl transpeptidase concentrations were not significant. The median concentration of at least one biomarker was increased in all but three patients with pre-renal AKI. Thus, the reason why some but not all biomarkers were increased requires further study. The results suggest that pre-renal AKI represents a milder form of injury

Az Árpád-ház filogenetikai eredetének meghatározása III. Béla apai ágának elemzése alapján

Célunk az Árpád-ház eredetének feltárása volt az eredetileg a székesfehérvári székesegyházban eltemetett III. Béla magyar király (1172–1196) és további 8 személy (6 férfi, 2 nő) csontvázmaradványaiból származó DNS genomszekvenálásával. Az Y-kromoszóma-elemzés megállapította, hogy két egyed, III. Béla és a HU52 jelzetű, az R-Z2125 haplocsoportba tartozik, amelyeknek eloszlása Délkelet-Ázsia közelében koncentrálódik, másodlagos kiterjedése a mai Irán, a Volga uráli térsége és a Kaukázus térsége. Ezekről a területekről 4340 egyed genomját szekvenáltuk, és az így kapott mintaszettből 208 esetben állapítottuk meg, hogy az R-Z2123-as haplocsoportba tartoznak. Ezekből az adatokból megállapítottuk, hogy az Árpád-ház legközelebbi rokonai (az R-SUR51) a modern kori Baskíriából származtak, elsősorban az Oroszországban található Baskíriából, annak Burzjan és Abzelil járásaiból. Elemzésünk feltárta olyan SNP-k meglétét is, amelyek egy új, Árpád-ház-specifikus R-ARP haplocsoportot határoznak meg. Az R-Z2123 nagy felbontású filogenenetikai kontextusában az első magyar királyi dinasztia eredete az Észak-Afganisztán környéki régiókban jelölhető meg, körülbelül 4500 évvel ezelőttire tehető, és a baskírokat azonosítja legközelebbi rokonként. A két népesség szétválásának időpontja pedig az időszámításunk szerinti első évezred eleje

The Association between Self-Reported Difficulties in Emotion Regulation and Heart Rate Variability: The Salient Role of Not Accepting Negative Emotions

Difficulties in emotion regulation are associated with development and maintenance of psychopathology. Typically, features of emotion regulation are assessed with self-report questionnaires. Heart rate variability (HRV) is an objective measure proposed as an index of emotional regulation capacity. A limited number of studies have shown that self-reported difficulties in emotion regulation are associated with HRV. However, results from prior studies are inconclusive, and an ecological validation of the association has not yet been tested. Therefore, further exploration of the relation between self-report questionnaires and psychophysiological measures of emotional regulation is needed. The present study investigated the contribution of self-reported emotion regulation difficulties on HRV in a student sample. We expected higher scores on emotion regulation difficulties to be associated with lower vagus-mediated HRV (vmHRV). Sixty-three participants filled out the Difficulties in Emotion Regulation Scale and their resting HRV was assessed. In addition, a subsample of participants provided ambulatory 24-h HRV data, in order to ecologically validate the resting data. Correlation analyses indicated that self-reported difficulties in emotion regulation was negatively associated with vmHRV in both resting HRV and 24-h HRV. Specifically, when exploring the contribution of the different facets of emotion dysregulation, the inability to accept negative emotions showed the strongest association with HRV. The results are discussed and need for future research is described

“Platelet-associated regulatory system (PARS)” with particular reference to female reproduction

BACKGROUND: Blood platelets play an essential role in hemostasis, thrombosis and coagulation of blood. Beyond these classic functions their involvement in inflammatory, neoplastic and immune processes was also investigated. It is well known, that platelets have an armament of soluble molecules, factors, mediators, chemokines, cytokines and neurotransmitters in their granules, and have multiple adhesion molecules and receptors on their surface. METHODS: Selected relevant literature and own views and experiences as clinical observations have been used. RESULTS: Considering that platelets are indispensable in numerous homeostatic endocrine functions, it is reasonable to suppose that a platelet-associated regulatory system (PARS) may exist; internal or external triggers and/or stimuli may complement and connect regulatory pathways aimed towards target tissues and/or cells. The signal (PAF, or other tissue/cell specific factors) comes from the stimulated (by the e.g., hypophyseal hormones, bacteria, external factors, etc.) organs or cells, and activates platelets. Platelet activation means their aggregation, sludge formation, furthermore the release of the for-mentioned biologically very powerful factors, which can locally amplify and deepen the tissue specific cell reactions. If this process is impaired or inhibited for any reason, the specifically stimulated organ shows hypofunction. When PARS is upregulated, organ hyperfunction may occur that culminate in severe diseases. CONCLUSION: Based on clinical and experimental evidences we propose that platelets modulate the function of hypothalamo-hypophyseal-ovarian system. Specifically, hypothalamic GnRH releases FSH from the anterior pituitary, which induces and stimulates follicular and oocyte maturation and steroid hormone secretion in the ovary. At the same time follicular cells enhance PAF production. Through these pathways activated platelets are accumulated in the follicular vessels surrounding the follicle and due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters) locally increase oocyte maturation and hormone secretion. Therefore we suggest that platelets are not only a small participant but may be the conductor or active mediator of this complex regulatory system which has several unrevealed mechanisms. In other words platelets are corpuscular messengers, or are more than a member of the family providing hemostasis