173 research outputs found

    The graphs with all but two eigenvalues equal to 2-2 or 00

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    We determine all graphs for which the adjacency matrix has at most two eigenvalues (multiplicities included) not equal to 2-2, or 00, and determine which of these graphs are determined by their adjacency spectrum

    Notes on simplicial rook graphs

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    The simplicial rook graph SR(m,n){\rm SR}(m,n) is the graph of which the vertices are the sequences of nonnegative integers of length mm summing to nn, where two such sequences are adjacent when they differ in precisely two places. We show that SR(m,n){\rm SR}(m,n) has integral eigenvalues, and smallest eigenvalue s=max(n,(m2))s = \max (-n, -{m \choose 2}), and that this graph has a large part of its spectrum in common with the Johnson graph J(m+n1,n)J(m+n-1,n). We determine the automorphism group and several other properties

    Higher Education Instructional Change in a U.S. Context: Investigating the Scholarship of Teaching and Learning (SoTL) Innovations at Niagara University

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    A metà Settembre 2013, due degli autori di questo articolo sono stati a Lecce (Italia) realizzando una presentazionein una conferenza sull’istruzione superiore. In quella sede, è stato possibile condividere con i partecipanti i dieci cambiamenti più potenti e significativi che hanno avuto luogo nel vasto panoramadell’accademia americana. L’elenco si componeva di sviluppi di tipo teorico; così come da diversi livelli di implementazione e pratica presso l’Università di Niagara, nell’angolo Nord Est degli Stati Uniti. Tra le iniziative messe in evidenza è stata prima e soprattutto menzionato il lavoro di Ernest Boyer sulla Scholarshipof Teaching and Learning (SoTL), ovvero la sua visione su strade alternative comunque accademiche, basate sulla didattica, per il successo della formazione universitaria. Il percorso tracciato dal movimento SoTL cambia la cultura universitaria, collocando l’insegnamento come priorità; e la “scholarship” (ricerca didattica) emergente dagli studi sull’innovazione didattica come una disciplina di ricerca che può alinearse ad altre nell’ambito accademico. Le esperienze all’Università Niagara forniscono sia un caso di studio dell’implementazione dei suddetti concetti in una moderna istituzione americana; sia un’opportunità per la comparazione con i vari casi delle istituzioni italiane. Inoltre, il lavoro portato avanti dall’università di Niagara risulta competitivo con riguardo ad alcune delle più riconosciute università americane, potendo essere considerato all’avanguardia dell’emergente movimentoSoTL. Questo articolo fornisce un breve resoconto e definizione del modello di Boyer su SoTL, suggerendo come le istituzioni potrebbero adottare tale paradigma sia come strategia per lo sviluppo professionale accademico, sia come adeguata base per la valutazione del lavoro del docente universitario

    Genetic variation of the prion protein gene (PRNP) in alpaca (Vicugna pacos)

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    Transmissible spongiform encephalopathies (TSE) are caused by accumulation of a misfolded form of the prion protein (PrP). The normal cellular isoform of PrP is produced by the prion gene (PRNP) and is highly expressed in the central nervous system. Currently, there is an absence of information regarding the genetic sequence of alpaca PRNP and the potential susceptibility of this species to TSE. The objective of this study was to sequence the open reading frame of the alpaca prion gene and analyze this sequence for variation within the alpaca population and for homology to TSE-susceptible species. We sequenced the open reading frame of the prion gene of 40 alpacas of Huacaya or Suri descent. Length polymorphisms were identified within the sampled population. A subset (15%) of animals contained an additional 24 base pairs within the putative octapeptide repeat region. This polymorphism was independent of breed and sex. The majority (52.5%) of animals were heterozygous, possessing both longer and shorter alleles. Comparison with proven TSE-susceptible species (sheep, cattle, deer) revealed the following amino acid sequence variations: I6M, A16V, M17T, G92del, Q95_G96insG, N111S, R167K, N/T177S, I206V, S225Y, Y228S, Q230G, and L237del. Sequence alignment showed high homology compared to camel (\u3e 95%), sheep (\u3e 88%), cattle (\u3e 87%) and deer (\u3e 88%) PRNP sequence. This study demonstrates intraspecies variability within the PRNP open reading frame in alpacas and overall high sequence homology to TSE-susceptible species, providing foundational data for further research on the potential susceptibility of alpacas to TSE

    A randomized phase II non-comparative study of PF-04691502 and gedatolisib (PF-05212384) in patients with recurrent endometrial cancer.

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    Objective PF-04691502 and gedatolisib (PF-05212384) are potent, dual PI3K/mTOR inhibitors. This phase II study (B1271004) was conducted in patients with recurrent endometrial cancer following platinum-containing chemotherapy. The primary endpoint was to assess clinical benefit response (complete or partial response, or stable disease for ≥16weeks) following treatment with PF-04691502 or gedatolisib.Methods The main study consisted of four independent arms based on a Simon two-stage design. Patients were assigned to putative PI3K-basal (PF-04691502 or gedatolisib) or PI3K-activated (PF-04691502 or gedatolisib) arms based on stathmin-low or stathmin-high tumor expression, respectively. Japanese patients were also enrolled in a separate lead-in cohort.Results In stage 1 (main study), eighteen patients were randomized to PF-04691502 and 40 to gedatolisib. The two PF-04691502 arms were discontinued early due to unacceptable toxicity, including pneumonia and pneumonitis. The most common treatment-related adverse events associated with gedatolisib were nausea (53%), mucosal inflammation (50%), decreased appetite (40%), diarrhea (38%), fatigue (35%), and dysgeusia and vomiting (each 30%). Clinical benefit response rate was 53% (10/19) in the gedatolisib/stathmin-low arm and 26% (5/19) in the gedatolisib/stathmin-high arm. Safety profile and pharmacokinetic characteristics of both drugs in the Japanese lead-in cohort were comparable to the Western population.Conclusions Gedatolisib administered by weekly intravenous infusion demonstrated acceptable tolerability and moderate activity in patients with recurrent endometrial cancer. PF-04691502 daily oral dosing was not well tolerated. Clinical benefit response criteria for proceeding to stage 2 were only met in the gedatolisib/stathmin-low arm. Stathmin-high expression did not correlate with greater treatment efficacy. ClinicalTrials.gov registration ID: NCT01420081

    Predicting intention to treat HIV-infected patients among Tanzanian and Sudanese medical and dental students using the theory of planned behaviour - a cross sectional study

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    <p>Abstract</p> <p>Background</p> <p>The HIV epidemic poses significant challenges to the low income countries in sub Saharan Africa (SSA), affecting the attrition rate among health care workers, their level of motivation, and absenteeism from work. Little is known about how to deal with deterioration of human resources in the health care systems. This study aimed to predict the intention to provide surgical treatment to HIV infected patients among medical- and dental students in Tanzania and Sudan using an extended version of the Theory of Planned Behaviour (TPB).</p> <p>Methods</p> <p>Four hundred and seventy five medical- and dental students at the University of Dar es Salaam (mean age, 25 yr) and 642 dental students attending 6 public and private dental faculties in Khartoum (mean age 21.7 yr) completed self-administered TPB questionnaires in 2005 and 2007, respectively.</p> <p>Results</p> <p>Both Tanzanian and Sudanese students demonstrated strong intentions to provide care for people with HIV and AIDS. Stepwise linear regression revealed that the TPB accounted for 51% (43% in Tanzania and Sudan) of the variance in intention across study sites. After having controlled for country and past behaviour, the TPB in terms of attitudes, subjective norms and perceived behavioural control accounted for 34% and moral norms for an additional 2,3% of the explainable variance in intention. Across both study sites, attitudes were the strongest predictor of intention followed in descending order by subjective norms, moral norms and perceived behavioural control.</p> <p>Conclusion</p> <p>The TPB is applicable to students' care delivery intentions in the context of HIV and AIDS across the two SSA countries investigated. It is suggested that attitudes, subjective norms, moral norms and perceived behavioural control are key factors in students' willingness to treat AIDS and HIV infected patients and should be targets of interventions aimed at improving the quality of health care delivery in this context.</p

    Photopatterned antibodies for selective cell attachment

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    We present a phototriggerable system that allows for the spatiotemporal controlled attachment of selected cell types to a biomaterial using immobilized antibodies that specifically target individual cell phenotypes.o-Nitrobenzyl caged biotin was used to functionalize chitosan membranes and mediate site-specific coupling of streptavidin and biotinylated antibodies after light activation. The ability of this system to capture and immobilize specific cells on a surface was tested using endothelial-specific biotinylated antibodies and nonspecific ones as controls. Homogeneous patterned monolayers of human umbilical vein endothelial cells were obtained on CD31-functionalized surfaces. This is a simple and generic approach that is applicable to other ligands, materials, and cell types and shows the flexibility of caged ligands to trigger and control the interaction between cells and biomaterials.We thank Martina Knecht (MPIP) for help with the synthesis of caged biotin and Dr. Ron Unger and Prof. C. J. Kirkpatrick (University Clinic Mainz, RepairLab) for providing HUVECs. C.A.C. acknowledges funding support from the Portuguese Foundation for Science and Technology (FCT) (fellowship SFRH/BD/61390/2009) and from the International Max-Planck Research School in Mainz. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. REGPOT-CT2012-316331-POLARIS

    Human adipose stem cells cell sheet constructs impact epidermal morphogenesis in full-thickness excisional wounds

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    Among the wide range of strategies to target skin repair/regeneration, tissue engineering (TE) with stem cells at the forefront, remains as the most promising route. Cell sheet (CS) engineering is herein proposed, taking advantage of particular cell-cell and cell-extracellular matrix (ECM) interactions and subsequent cellular milieu, to create 3D TE constructs to promote full-thickness skin wound regeneration. Human adipose derived stem cells (hASCs) CS were obtained within five days using both thermoresponsive and standard cell culture surfaces. hASCs-based constructs were then built by superimposing three CS and transplanted into full-thickness excisional mice skin wounds with delayed healing. Constructs obtained using thermoresponsive surfaces were more stable than the ones from standard cell culture surfaces due to the natural adhesive character of the respective CS. Both CS-generating strategies lead to prolonged hASCs engraftment, although no transdifferentiation phenomena were observed. Moreover, our findings suggest that the transplanted hASCs might be promoting neotissue vascularization and extensively influencing epidermal morphogenesis, mainly through paracrine actions with the resident cells. The thicker epidermis, with a higher degree of maturation characterized by the presence of rete ridges-like structures, as well as a significant number of hair follicles observed after transplantation of the constructs combining the CS obtained from the thermoresponsive surfaces, reinforced the assumptions of the influence of the transplanted hASCs and the importance of the higher stability of these constructs promoted by cohesive cell-cell and cell-ECM interactions. Overall, this study confirmed the potential of hASCs CS-based constructs to treat full-thickness excisional skin wounds and that their fabrication conditions impact different aspects of skin regeneration, such as neovascularisation, but mainly epidermal morphogenesis.We would like to thank Hospital da Prelada (Porto), in particular, to Dr. Paulo Costa for the lipoaspirates collection and for financial support by Skingineering (PTDC/SAU-OSM/099422/2008), Portuguese Foundation for Science and Technology (FCT) funded project. The research leading to these results has also received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. REGPOT-CT2012-316331-POLARIS
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