299 research outputs found

    Ranked prediction of p53 targets using hidden variable dynamic modeling

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    Full exploitation of microarray data requires hidden information that cannot be extracted using current analysis methodologies. We present a new approach, hidden variable dynamic modeling (HVDM), which derives the hidden profile of a transcription factor from time series microarray data, and generates a ranked list of predicted targets. We applied HVDM to the p53 network, validating predictions experimentally using small interfering RNA. HVDM can be applied in many systems biology contexts to predict regulation of gene activity quantitatively

    Do Irrelevant Sounds Impair the Maintenance of All Characteristics of Speech in Memory?

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    Several studies have shown that maintaining in memory some attributes of speech, such as the content or pitch of an interlocutor's message, is markedly reduced in the presence of background sounds made of spectrotemporal variations. However, experimental paradigms showing this interference have only focused on one attribute of speech at a time, and thus differ from real-life situations in which several attributes have to be memorized and maintained simultaneously. It is possible that the interference is even greater in such a case and can occur for a broader range of background sounds. We developed a paradigm in which participants had to maintain the content, pitch and speaker size of auditorily presented speech information and used various auditory distractors to generate interference. We found that only distractors with spectrotemporal variations impaired the detection, which shows that similar interference mechanisms occur whether there are one or more speech attributes to maintain in memory. A high percentage of false alarms was observed with these distractors, suggesting that spectrotemporal variations not only weaken but also modify the information maintained in memory. Lastly, we found that participants were unaware of the interference. These results are similar to those observed in the visual modalit

    On the metric dimension of corona product graphs

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    Given a set of vertices S={v1,v2,...,vk}S=\{v_1,v_2,...,v_k\} of a connected graph GG, the metric representation of a vertex vv of GG with respect to SS is the vector r(vS)=(d(v,v1),d(v,v2),...,d(v,vk))r(v|S)=(d(v,v_1),d(v,v_2),...,d(v,v_k)), where d(v,vi)d(v,v_i), i{1,...,k}i\in \{1,...,k\} denotes the distance between vv and viv_i. SS is a resolving set for GG if for every pair of vertices u,vu,v of GG, r(uS)r(vS)r(u|S)\ne r(v|S). The metric dimension of GG, dim(G)dim(G), is the minimum cardinality of any resolving set for GG. Let GG and HH be two graphs of order n1n_1 and n2n_2, respectively. The corona product GHG\odot H is defined as the graph obtained from GG and HH by taking one copy of GG and n1n_1 copies of HH and joining by an edge each vertex from the ithi^{th}-copy of HH with the ithi^{th}-vertex of GG. For any integer k2k\ge 2, we define the graph GkHG\odot^k H recursively from GHG\odot H as GkH=(Gk1H)HG\odot^k H=(G\odot^{k-1} H)\odot H. We give several results on the metric dimension of GkHG\odot^k H. For instance, we show that given two connected graphs GG and HH of order n12n_1\ge 2 and n22n_2\ge 2, respectively, if the diameter of HH is at most two, then dim(GkH)=n1(n2+1)k1dim(H)dim(G\odot^k H)=n_1(n_2+1)^{k-1}dim(H). Moreover, if n27n_2\ge 7 and the diameter of HH is greater than five or HH is a cycle graph, then $dim(G\odot^k H)=n_1(n_2+1)^{k-1}dim(K_1\odot H).

    Управління комплексною вентиляційною мережею соляної шахти Trotus

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    The attestation of salt extraction in these areas was located in the Geto-Dacian period at Oituz and Târgu Ocna. The oldest written testimony dates from 1380. The mining works that serve the Trotuş mine within the Tg. Ocna Salt Mine, are located in the Feţele Târgului salt massif located near the town of Tg. Ocna, on the left side of the Trotuş river. The exploitation of the salt was carried out until 1870 at the Ocnița Mine with a bell-shaped chamber and continued in the Moldova Veche and Moldova Nouă mines with trapezoidal chambers. Since 1967, the salt has been exploited with "small rooms and abandoned square pillars". The exploitation is carried out descending, on the horizons. Currently, the Trotuș Salt Mine has 14 horizons: 2 at the Pilot mine and 12 at the Trotuș mine. The specialized 3D CANVENT program was used to establish the optimal distribution of air flows. A number of 492 junctions and 697 branches were used to solve the ventilation network related to the Trotuș Salt Mine.Атестація видобутку солі в цих районах проходила в гето-дакійський період в Ойтузі та Тиргу-Очна. Найдавніші письмові свідчення датуються 1380 роком. Гірничі роботи, що обслуговують шахту Тротуш у межах Тг. Соляна шахта Окна, розташована в соляному масиві Фецеле-Тиргулуй, що знаходиться недалеко від міста Тг. Очна, з лівого боку річки Тротуш. Експлуатація солі велася до 1870 р. На шахті Окниця з дзвоноподібною камерою і продовжувалась у шахтах Молдова Вече та Молдова Ноуа з трапецієподібними камерами. З 1967 р. Сіль експлуатується в "маленьких кімнатах і занедбаних квадратних стовпах". Експлуатація здійснюється низхідно, по горизонтах. В даний час соляна шахта Тротуш має 14 горизонтів: 2 на пілотній шахті та 12 на шахті Тротуш. Для встановлення оптимального розподілу повітряних потоків була використана спеціалізована програма 3D CANVENT. Для вирішення вентиляційної мережі, що стосується соляної шахти Тротуш, було використано 492 перехрестя та 697 гілок

    RNA Polymerase Pausing during Initial Transcription

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    In bacteria, RNA polymerase (RNAP) initiates transcription by synthesizing short transcripts that are either released or extended to allow RNAP to escape from the promoter. The mechanism of initial transcription is unclear due to the presence of transient intermediates and molecular heterogeneity. Here, we studied initial transcription on a lac promoter using single-molecule fluorescence observations of DNA scrunching on immobilized transcription complexes. Our work revealed a long pause (‘‘initiation pause,’’ �20 s) after synthesis of a 6-mer RNA; such pauses can serve as regulatory checkpoints. Region sigma 3.2, which contains a loop blocking the RNA exit channel, was a major pausing determinant. We also obtained evidence for RNA backtracking during abortive initial transcription and for additional pausing prior to escape. We summarized our work in a model for initial transcription, in which pausing is controlled by a complex set of determinants that modulate the transition from a 6- to a 7-nt RNA

    Randomly Broken Nuclei and Disordered Systems

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    Similarities between models of fragmenting nuclei and disordered systems in condensed matter suggest corresponding methods. Several theoretical models of fragmentation investigated in this fashion show marked differences, indicating possible new methods for distinguishing models using yield data. Applying nuclear methods to disordered systems also yields interesting results.Comment: 10 pages, 4 figure

    Liver retransplantation as a therapeutic method in graft dysfunctions in the immediate postoperative period

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    Departament Chirurgie Generală, I.C. Fundeni, București, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaCu toate că în ultimii ani au apărut progrese importante în domeniul hepatic, problema prevenirii apariției disfuncției și eșecului post-transplant nu a prezentat progrese semnificative. Intrucât disfuncția hepatică primară influențează dramatic evoluția grefei și a pacientului transplantat hepatic, prevenirea acestui fenomen devine obligatoriu. Creșterea penuriei de organe și a numărului persoanelor aflate pe lista de așteptare a dus la folosirea unor grefe ce depășesc criteriile normale de selecție pentru recoltare precum și transplantarea unor donatori considerați marginali. Aceste circumstanțe au adus în prim plan importanța diagnosticării și tratamentului disfuncției hepatice primare. Conceptul de disfuncție hepatică primară nu este clar definit. Există un spectru de evenimente ce definesc disfuncția hepatică postoperatorie precoce: non funcția primară (PNF), nonfuncția întârziată, funcția slabă/săracă inițială (initial poor function – IPF), non funcția inițială, insuficiența hepatică primară și disfuncția primară. Distincția între aceste entități ia în considerare gradul disfuncției hepatice, necesitatea retransplantării urgente, precum și apariția și durata acestor evenimente după transplantul hepatic.Although important progress has been made over the last few years, the problem of preventing dysfunction and post-transplant liver failure has not shown significant progress. Since primary liver dysfunction dramatically influences the progress of the graft and the liver transplant patient, prevention of this phenomenon becomes obligatory. The increase in organ shortage and the number of people on the waiting list led to the use of grafts that exceeded the normal selection criteria for harvesting as well as the transplantation of marginal donors. These circumstances have highlighted the importance of diagnosis and treatment of primary hepatic dysfunction. The concept of primary liver dysfunction is not clearly defined. There is a spectrum of events that defines early postoperative liver dysfunction: primary non-function (PNF), delayed dysfunction, initial poor function (IPF), primary hepatic failure, and primary dysfunction. The distinction between these entities takes into account the degree of hepatic dysfunction, the need for urgent retransplantation, and the occurrence and duration of these events after liver transplantation

    Ethnicity and Cutaneous Melanoma in the City of Sao Paulo, Brazil: A Case-Control Study

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    Background: Over the last century the incidence of cutaneous melanoma has increased worldwide, a trend that has also been observed in Brazil. The identified risk factors for melanoma include the pattern of sun exposure, family history, and certain phenotypic features. In addition, the incidence of melanoma might be influenced by ethnicity. Like many countries, Brazil has high immigration rates and consequently a heterogenous population. However, Brazil is unique among such countries in that the ethnic heterogeneity of its population is primarily attributable to admixture. This study aimed to evaluate the contribution of European ethnicity to the risk of cutaneous melanoma in Brazil. Methodology/Principal Findings: We carried out a hospital-based case-control study in the metropolitan area of Sao Paulo, Brazil. We evaluated 424 hospitalized patients (202 melanoma patients and 222 control patients) regarding phenotypic features, sun exposure, and number of grandparents born in Europe. Through multivariate logistic regression analysis, we found the following variables to be independently associated with melanoma: grandparents born in Europe-Spain (OR = 3.01, 95% CI: 1.03-8.77), Italy (OR = 3.47, 95% CI: 1.41-8.57), a Germanic/Slavic country (OR = 3.06, 95% CI: 1.05-8.93), or >= 2 European countries (OR = 2.82, 95% CI: 1.06-7.47); eye color-light brown (OR = 1.99, 95% CI: 1.14-3.84) and green/blue (OR = 4.62; 95% CI 2.22-9.58); pigmented lesion removal (OR = 3.78; 95% CI: 2.21-6.49); no lifetime sunscreen use (OR = 3.08; 95% CI: 1.03-9.22); and lifetime severe sunburn (OR = 1.81; 95% CI: 1.03-3.19). Conclusions: Our results indicate that European ancestry is a risk factor for cutaneous melanoma. Such risk appears to be related not only to skin type, eye color, and tanning capacity but also to others specific characteristics of European populations introduced in the New World by European immigrants.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP [06-52041-9, 5-56069-2]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - Brasil (National Counsel of Technological and Scientific Development - Brazil) - CNPq [478239/03-3]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico Brasil (National Counsel of Technological and Scientific Development Brazil) CNP
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