299 research outputs found
Ranked prediction of p53 targets using hidden variable dynamic modeling
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?
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
Given a set of vertices of a connected graph , the
metric representation of a vertex of with respect to is the vector
, where ,
denotes the distance between and . is a resolving set for if
for every pair of vertices of , . The metric
dimension of , , is the minimum cardinality of any resolving set for
. Let and be two graphs of order and , respectively. The
corona product is defined as the graph obtained from and by
taking one copy of and copies of and joining by an edge each
vertex from the -copy of with the -vertex of . For any
integer , we define the graph recursively from
as . We give several results on the metric
dimension of . For instance, we show that given two connected
graphs and of order and , respectively, if the
diameter of is at most two, then .
Moreover, if and the diameter of is greater than five or 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
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
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
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
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
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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