348 research outputs found
A method for computing Lucas sequences
AbstractMost of public-key cryptosystems rely on one-way functions, which can be used to encrypt and sign messages. Their encryption and signature operations are based on the computation of exponentiation. Recently, some public-key cryptosystems are proposed and based on Lucas functions, and the Lucas sequences are performed as S = V(d)modN. In this paper, we will transform the concept of addition chains for computing the exponentiation evaluations to the Lucas chains for computing the Lucas sequences. Theoretically, the shorter Lucas chain for d is generated, the less computation time for evaluating the value V(d) is required. Therefore, we proposed a heuristic algorithm for evaluating a shorter Lucas chain and then use it to compute the Lucas sequence with less modular multiplications
Improvement of n-butanol tolerance in Escherichia coli by membrane-targeted tilapia metallothionein
Background: Though n-butanol has been proposed as a potential transportation biofuel, its toxicity oftencauses oxidative stress in the host microorganism and is considered one of the bottlenecks preventing itsefficient mass production.Results: To relieve the oxidative stress in the host cell, metallothioneins (MTs), which are known as scavengersfor reactive oxygen species (ROS), were engineered in E. coli hosts for both cytosolic and outer-membrane-targeted (osmoregulatory membrane protein OmpC fused) expression. Metallothioneins from human (HMT),mouse (MMT), and tilapia fish (TMT) were tested. The host strain expressing membrane-targeted TMT showed thegreatest ability to reduce oxidative stresses induced by n-butanol, ethanol, furfural, hydroxymethylfurfural, andnickel. The same strain also allowed for an increased growth rate of recombinant E. coli under n-butanol stress.Further experiments indicated that the TMT-fused OmpC protein could not only function in ROS scavenging butalso regulate either glycine betaine (GB) or glucose uptake via osmosis, and the dual functional fusion proteincould contribute in an enhancement of the host microorganism’s growth rate.Conclusions: The abilities of scavenging intracellular or extracellular ROS by these engineering E. coli wereexamined, and TMT show the best ability among three MTs. Additionally, the membrane-targeted fusion protein,OmpC-TMT, improved host tolerance up to 1.5% n-butanol above that of TMT which is only 1%. These resultspresented indicate potential novel approaches for engineering stress tolerant microorganism strains
Acupuntura: prática baseada em evidências
Acupuncture has been put in evidence more recently. It represents an ascending practice among under-graduated medical students, as well as among graduated physicians in search for their specialization. Recently, acupuncture won BMA approval, which not only recommended NHS to accept acupuncture to treat chronic headache, but suggested that more primary care doctors should be trained to practice acupuncture. In a review of some recent studies, acupuncture has been studied as a validated practice to treat conditions like systemic arterial hypertension and in vitro fertilization, conditions which differ from usual indication of acupuncture. This new situation put a new perspective to acupuncture, perhaps it is on due time that acupuncture should be considered as part of orthodox medicine.A acupuntura está cada vez mais em evidĂŞncia, alĂ©m de ser uma especialidade em ascensĂŁo tanto entre os estudantes de medicina, como entre os mĂ©dicos que buscam a sua especialização, ganhou destaque da Associação MĂ©dica Britânica que advogou a sua aprovação perante a comunidade mĂ©dica britânica, alĂ©m de recomendar o Sistema de SaĂşde PĂşblica Britânica a aceitar o tratamento de cefalĂ©ia crĂ´nica por acupuntura, aconselha que o mesmo encoraje os mĂ©dicos de atenção primária a passar por treinamento em acupuntura. Na revisĂŁo de trabalhos recentes, a acupuntura está sendo pesquisada para o tratamento de diversas molĂ©stias ou condições clĂnicas diferentes daquelas a que eram indicadas. Situações como hipertensĂŁo arterial sistĂŞmica e fertilização in vitro, a acupuntura tem sido estudada como opções de tratamento válidas. Essa situação coloca uma nova perspectiva para a especialidade acupuntura, que está sendo considerada cada vez como uma prática em saĂşde validada, dentro dos paradigmas da medicina ortodoxa
Acupuncture: a validated therapeutic modality in updated physician therapeutic arsenal
One of the most ancient therapeutic maneuvers, acupuncture is part of Traditional Chinese Medicine. Based in ancient philosophic thinking and observation of naturally occurred phenomena, Traditional Chinese Medicine possesses peculiar pathophysiology,complicated diagnosis system based on examination of pulse, tongue and observation of patients´ behavior and attitudes. During long decades, acupuncture has been considered as an exotic alternative to Orthodox Western Medicine, however, recent studies and the panel studies promoted by NIH (National Institutes of Health) in 1988 have elected acupuncture asa validated therapy for a long listed health disorders, thus transforming acupuncture as a serious therapeutic modality. More discussions and studies should be evaluated in order to obtaining more evidence-based indication for acupuncture and to carry out the medical education in teaching acupuncture.Uma das mais antigas modalidades de terapĂŞutica, acupuntura faz parte da MedicinaTradicional Chinesa. Baseada principalmente em um antigo pensamento filosĂłfico chinĂŞs e na observação da ocorrĂŞncia de fenĂ´menos da natureza. Medicina Tradicional Chinesa possui uma fisiopatologia peculiar, um sistema de diagnĂłstico complicado baseado em exame de lĂngua e pulso e na observação de comportamento e atitudes de pacientes. Durante dĂ©cadas,a acupuntura foi considerada uma alternativa exĂłtica Ă Medicina Ocidental Ortodoxa, entretanto, estudos recentes e estudos de painel do NIH norte americano em 1988 elegeram a acupuntura como uma terapia validada para uma extensa lista de afecções, transformando a em uma modalidade terapĂŞutica sĂ©ria. Necessitamos de mais estudos e discussões para aumentar as indicações baseadas em evidĂŞncia para outras afecções, alĂ©m de ajudar a implementar a educação mĂ©dica em acupuntura
Regulation of neuroD2 expression in mouse brain
AbstractThe basic helix–loop–helix (bHLH) transcription factor, neuroD2, induces neuronal differentiation and promotes neuronal survival. Reduced levels of neuroD2 were previously shown to cause motor deficits, ataxia, and seizure propensity. Because neuroD2 levels may be critical for brain function, we studied the regulation of neuroD2 gene in cell culture and transgenic mouse models. In transgenic mice, a 10-kb fragment of the neuroD2 promoter fully recapitulated the endogenous neuroD2 staining pattern. A 1-kb fragment of the neuroD2 promoter drove reporter gene expression in most, but not all neuroD2-positive neuronal populations. Mutation of two critical E-boxes, E4 and E5 (E4 and E5 situated 149 and 305 bp upstream of the transcriptional start site) eliminated gene expression. NeuroD2 expression was diminished in mice lacking neurogenin1 demonstrating that neurogenin1 regulates neuroD2 during murine brain development. These studies demonstrate that neuroD2 expression is highly dependent on bHLH-responsive E-boxes in the proximal promoter region, that additional distal regulatory elements are important for neuroD2 expression in a subset of cortical neurons, and that neurogenin1 regulates neuroD2 expression during mouse brain development
The risk of false inclusion of a relative in parentage testing – an in silico population study
Aim To investigate the potential of false inclusion of a
close genetic relative in paternity testing by using computer
generated families.
Methods 10 000 computer-simulated families over three
generations were generated based on genotypes using 15
short tandem repeat loci. These data were used in assessing
the probability of inclusion or exclusion of paternity
when the father is actually a sibling, grandparent, uncle,
half sibling, cousin, or a random male. Further, we considered
a duo case where the mother’s DNA type was not
available and a trio case including the mother’s profile.
Results The data showed that the duo scenario had the
highest and lowest false inclusion rates when considering
a sibling (19.03 ± 0.77%) and a cousin (0.51 ± 0.14%) as
the father, respectively; and the rate when considering a
random male was much lower (0.04 ± 0.04%). The situation
altered slightly with a trio case where the highest rate
(0.56 ± 0.15%) occurred when a paternal uncle was considered
as the father, and the lowest rate (0.03 ± 0.03%) occurred
when a cousin was considered as the father. We also
report on the distribution of the numbers for non-conformity
(non-matching loci) where the father is a close genetic
relative.
Conclusions The results highlight the risk of false inclusion
in parentage testing. These data provide a valuable
reference when incorporating either a mutation in the father’s
DNA type or if a close relative is included as being
the father; particularly when there are varying numbers of
non-matching loci
A novel strategy for sibship determination in trio sibling model
Aim To use a virtually simulated population, generated
from published allele frequencies based on 15 short tandem
repeats (STR), to evaluate the efficacy of trio sibship
testing and sibling assignment for forensic purposes.
Methods Virtual populations were generated using 15 STR
loci to create a large number of related and unrelated genotypes
(10 000 trio combinations). Using these virtual populations,
the probability of related and unrelated profiles
can be compared to determine the chance of inclusions
of being siblings if they are true siblings and the chance of
inclusion if they are unrelated. Two specific relationships
were tested – two reference siblings were compared to a
third true sibling (3S trio, sibling trio) and two reference siblings
were compared to an unrelated individual (2S1U trio,
non-sibling trio).
Results When the likelihood ratio was greater than 1,
99.87% of siblings in the 3S trio population were considered
as siblings (sensitivity); 99.88% of non-siblings in the
2S1U trio population were considered as non-siblings
(specificity); 99.9% of both populations were identified correctly
as siblings and non-siblings; and the accuracy of the
test was 99.88%.
Conclusions The high sensitivity and specificity figures
when using two known siblings compared to a putative
sibling are significantly greater than when using only one
known relative. The data also support the use of increasing
number of loci allowing for greater confidence in genetic
identification. The system established in this study could
be used as the model for evaluating and simulating the
cases with multiple relatives
Indigenous Case of Disseminated Histoplasmosis, Taiwan
We report the first indigenous case of disseminated histoplasmosis in Taiwan diagnosed by histopathology of bone marrow, microbiologic morphology, and PCR assay of the isolated fungus. This case suggests that histoplasmosis should be 1 of the differential diagnoses of opportunistic infections in immunocompromised patients in Taiwan
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