π\pi-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism

Elemental carbon represents a fundamental building block of matter and the possibility of ferromagnetic order in carbon attracted widespread attention. However, the origin of magnetic order in such a light element is only poorly understood and has puzzled researchers. We present a spectromicroscopy study at room temperature of proton irradiated metal free carbon using the elemental and chemical specificity of x-ray magnetic circular dichroism (XMCD). We demonstrate that the magnetic order in the investigated system originates only from the carbon $\pi$-electron system.Comment: 10 pages 3 color figure

Asymptotic harvesting of populations in random environments

We consider the harvesting of a population in a stochastic environment whose dynamics in the absence of harvesting is described by a one dimensional diffusion. Using ergodic optimal control, we find the optimal harvesting strategy which maximizes the asymptotic yield of harvested individuals. To our knowledge, ergodic optimal control has not been used before to study harvesting strategies. However, it is a natural framework because the optimal harvesting strategy will never be such that the population is harvested to extinction-instead the harvested population converges to a unique invariant probability measure. When the yield function is the identity, we show that the optimal strategy has a bang-bang property: there exists a threshold [Formula: see text] such that whenever the population is under the threshold the harvesting rate must be zero, whereas when the population is above the threshold the harvesting rate must be at the upper limit. We provide upper and lower bounds on the maximal asymptotic yield, and explore via numerical simulations how the harvesting threshold and the maximal asymptotic yield change with the growth rate, maximal harvesting rate, or the competition rate. We also show that, if the yield function is [Formula: see text] and strictly concave, then the optimal harvesting strategy is continuous, whereas when the yield function is convex the optimal strategy is of bang-bang type. This shows that one cannot always expect bang-bang type optimal controls

Esophageal surgery – the experience of the department of surgery of CME faculty of SUMPh “Nicolae Testemitanu”

Catedra chirurgie FECMF, USMF „Nicolae Testemiţanu”, Chişinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Esofagul, pentru chirurgi, rămâne un segment deosebit al tractului digestiv atât din cauza particularităţilor anatomo-topografice a organului, a căilor de acces către acesta, cât şi a tehnicilor operatorii asupra respectivului. Scopul lucrării: De a ne împărtăşi cu experienţa Clinicii de 30 ani în domeniul chirurgiei esofagiene. Material şi metode: Clinica de Chirurgie FECMF a USMF „Nicolae Testemiţanu” – secţia de chirurgie toracică şi chirurgie generală a Spitalului Clinic Republican îşi are direcţia cercetărilor, studiilor practico-ştiinţifice ale intervenţiilor pe esofag din 1974. Fişierul clinicii deţine mai mult de 1000 operaţii pe esofag. Rezultate: Punct de pornire au servit traumele esofagului adunând 70 cazuri. Alți 83 pacienţi – operaţi pentru diverticul, 192 cu hernii a hiatusului esofagian, 226 suferinzi de diferite forme de stenoze postcaustice, 118 pacienţi s -au operat pentru boala de reflux gastroesofagian, 115 cu achalazii, cu neoplasm esofagian s-au operat 92 pacienţi, esofag Barrett au avut 34 bolnavi, neoplasm al joncţiunii esofago-gastrice – 37 pacienţi. Avem 32 cazuri cu ruptură spontană de esofag (sindromul Boerhaave). Concluzii: Aceasta este experienţa Clinicii, în baza căreia s-a susţinut o teză de doctor habilitat şi două teze de doctor în medicină.Introduction: Esophageal surgery represents very special kind of digestive surgery, because of multiple factors – anatomical-topographic features, specific surgical access and surgical technique. Aim: To evaluate our clinical experience of 30 years of esophageal surgery. Material and methods: Since 1974, in the Department of Surgery of CME Faculty of SUMPh „Nicolae Testemitanu”, thoracic and general surgery departments of Republican Clinical Hospital, were performed about 1000 clinical cases of esophageal surgery. Results: Our first experience in esophageal surgery, as a start point was esophageal injuries – 70 patients, followed by esophageal diverticula – 83 patients, esophageal hiatus hernia – 192 treatment cases, esophageal stricture of various origin – 226 cases, 118 patients have been treated for gastro-esophageal reflux disease, 115 cases with achalasia of esophagus, 92 patients have been treated for esophageal cancer, 34 cases – with Barrett’s esophagus, gastroesophageal junction cancer – 37 cases. In addition, we have experience of 32 cases of spontaneous esophagus rupture (Boerhaave syndrome). Conclusions: The experience of the Clinic mentioned above was reflected in a thesis of doctor habilitatus of medical since and two thesis of doctor of medical since

The helicase HAGE prevents interferon-a-induced PML expression in ABCB5+ malignant melanoma-initiating cells by promoting the expression of SOCS1

The tumour suppressor PML (promyelocytic leukaemia protein) regulates several cellular pathways involving cell growth, apoptosis, differentiation and senescence. PML also has an important role in the regulation of stem cell proliferation and differentiation. Here, we show the involvement of the helicase HAGE in the transcriptional repression of PML expression in ABCB5 + malignant melanoma-initiating cells (ABCB5 + MMICs), a population of cancer stem cells which are responsible for melanoma growth, progression and resistance to drug-based therapy. HAGE prevents PML gene expression by inhibiting the activation of the JAK-STAT (janus kinase-signal transducers and activators of transcription) pathway in a mechanism which implicates the suppressor of cytokine signalling 1 (SOCS1). Knockdown of HAGE led to a significant decrease in SOCS1 protein expression, activation of the JAK-STAT signalling cascade and a consequent increase of PML expression. To confirm that the reduction in SOCS1 expression was dependent on the HAGE helicase activity, we showed that SOCS1, effectively silenced by small interfering RNA, could be rescued by re-introduction of HAGE into cells lacking HAGE. Furthermore, we provide a mechanism by which HAGE promotes SOCS1 mRNA unwinding and protein expression in vitro

On limit periodicity of discrete time stochastic processes

We consider a discrete time dynamic system described by a difference equation with periodic coefficients and with additive stochastic noise. We investigate the possibility of the periodicity of the solution. In particular, we established sufficient conditions for convergence of the solution in mean square or almost surely to some stochastic periodic process

ASPECTS ON OPTIMIZING THE QUALITATIVE INDICES OF THE WORK OF SPRAYING FIELD CROPS

In the context of continuous development and improvement of machinery forapplying phytosanitary treatments, the increase of precision of the dose applied to crops has become a target for major manufacturers of such equipment, the solutions applied on machinery aiming to improve the application technology, using automation and control systems driven from the operator cabin. This paper presents the most important aspects to be taken into account when working with a machinery for applying phytosanitary treatments, in order to obtain an optimization of qualitative indices of the spraying work of field crops

Two <em>Dictyostelium</em> Tyrosine Kinase-Like kinases function in parallel, stress-induced STAT activation pathways

When Dictyostelium cells are hyperosmotically stressed, STATc is activated by tyrosine phosphorylation. Unusually, activation is regulated by serine phosphorylation and consequent inhibition of a tyrosine phosphatase: PTP3. The identity of the cognate tyrosine kinase is unknown, and we show that two tyrosine kinase–like (TKL) enzymes, Pyk2 and Pyk3, share this function; thus, for stress-induced STATc activation, single null mutants are only marginally impaired, but the double mutant is nonactivatable. When cells are stressed, Pyk2 and Pyk3 undergo increased autocatalytic tyrosine phosphorylation. The site(s) that are generated bind the SH2 domain of STATc, and then STATc becomes the target of further kinase action. The signaling pathways that activate Pyk2 and Pyk3 are only partially overlapping, and there may be a structural basis for this difference because Pyk3 contains both a TKL domain and a pseudokinase domain. The latter functions, like the JH2 domain of metazoan JAKs, as a negative regulator of the kinase domain. The fact that two differently regulated kinases catalyze the same phosphorylation event may facilitate specific targeting because under stress, Pyk3 and Pyk2 accumulate in different parts of the cell; Pyk3 moves from the cytosol to the cortex, whereas Pyk2 accumulates in cytosolic granules that colocalize with PTP3

COMMD1 promotes the ubiquitination of NF‐κB subunits through a cullin‐containing ubiquitin ligase

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102213/1/emboj7601489.pd

Analysis of jak2 catalytic function by peptide microarrays: The role of the JH2 domain and V617F mutation

Janus kinase 2 (JAK2) initiates signaling from several cytokine receptors and is required for biological responses such as erythropoiesis. JAK2 activity is controlled by regulatory proteins such as Suppressor of Cytokine Signaling (SOCS) proteins and protein tyrosine phosphatases. JAK2 activity is also intrinsically controlled by regulatory domains, where the pseudokinase (JAK homology 2, JH2) domain has been shown to play an essential role. The physiological role of the JH2 domain in the regulation of JAK2 activity was highlighted by the discovery of the acquired missense point mutation V617F in myeloproliferative neoplasms (MPN). Hence, determining the precise role of this domain is critical for understanding disease pathogenesis and design of new treatment modalities. Here, we have evaluated the effect of inter-domain interactions in kinase activity and substrate specificity. By using for the first time purified recombinant JAK2 proteins and a novel peptide micro-array platform, we have determined initial phosphorylation rates and peptide substrate preference for the recombinant kinase domain (JH1) of JAK2, and two constructs comprising both the kinase and pseudokinase domains (JH1-JH2) of JAK2. The data demonstrate that (i) JH2 drastically decreases the activity of the JAK2 JH1 domain, (ii) JH2 increased the Kmfor ATP (iii) JH2 modulates the peptide preference of JAK2 (iv) the V617F mutation partially releases this inhibitory mechanism but does not significantly affect substrate preference or Kmfor ATP. These results provide the biochemical basis for understanding the interaction between the kinase and the pseudokinase domain of JAK2 and identify a novel regulatory role for the JAK2 pseudokinase domain. Additionally, this method can be used to identify new regulatory mechanisms for protein kinases that provide a better platform for designing specific strategies for therapeutic approaches

RESEARCH ON THE DEVELOPMENT OF A CONSERVATIVE TECHNOLOGY, USING OPTIMIZED ACTIVE BODIES FOR SOIL TILLAGE

Conservative agriculture has grown particularly in developed countries over the past20 years, due to intensive use of soils to obtain higher yields, by means of the processing works, maintenance, herbicides, etc. (even several times during a year), which in time led to the degradation and destruction of the structure and properties of soils. In this context, this paper presents the research conducted in order to develop a conservative technology based on optimized active bodies for soil tillage, to be mounted on a complex aggregate, in order to reduce wear, deformation and increase its lifetime