607 research outputs found
Critical behavior of the compact 3d U(1) theory in the limit of zero spatial coupling
Critical properties of the compact three-dimensional U(1) lattice gauge
theory are explored at finite temperatures on an asymmetric lattice. For
vanishing value of the spatial gauge coupling one obtains an effective
two-dimensional spin model which describes the interaction between Polyakov
loops. We study numerically the effective spin model for N_t=1,4,8 on lattices
with spatial extension ranging from L=64 to L=256. Our results indicate that
the finite-temperature U(1) lattice gauge theory belongs to the universality
class of the two-dimensional XY model, thus supporting the Svetitsky-Yaffe
conjecture.Comment: 17 pages, 5 figures; two references added, a few comments included,
title changed; version to appear on J. Stat. Mec
Critical behavior of the compact 3d U(1) gauge theory on isotropic lattices
We report on the computation of the critical point of the deconfinement phase
transition, critical indices and the string tension in the compact three
dimensional U(1) lattice gauge theory at finite temperatures. The critical
indices govern the behavior across the deconfinement phase transition in the
pure gauge U(1) model and are generally expected to coincide with the critical
indices of the two-dimensional XY model. We studied numerically the U(1) model
for N_t=8 on lattices with spatial extension ranging from L=32 to L=256. Our
determination of the infinite volume critical point on the lattice with N_t=8
differs substantially from the pseudo-critical coupling at L=32, found earlier
in the literature and implicitly assumed as the onset value of the deconfined
phase. The critical index computed from the scaling of the
pseudo-critical couplings with the extension of the spatial lattice agrees well
with the XY value =1/2. On the other hand, the index shows large
deviation from the expected universal value. The possible reasons of such
behavior are discussed in details.Comment: 15 pages, 7 figures; version accepted for publication on J. Stat.
Mech
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Hypoimmunogenic Derivatives of Induced Pluripotent Stem Cells Evade Immune Rejection in Fully Immunocompetent Allogeneic Recipients
LONG-TERM TEMPERATURE MONITORING OF VOLCANIC AREAS BY DISTRIBUTED OPTICAL FIBER SENSORS
We present the first results of long- term monitoring of temperature profiles at the Campi
Flegrei caldera. The measurements were carried out along a 76 meters-deep borehole
already equipped with a borehole strain-meter. We installed a cable containing a loop of
optical fiber in order to use a fiber-optics distributed sensor based on stimulated
Brillouin scattering. The obtained data are consistent with results of both deep and
surface geothermal explorations and indicate that geothermal gradient can be efficiently
measured and monitored by the proposed technique
Biological rationale for the use of DNA methyltransferase inhibitors as new strategy for modulation of tumor response to chemotherapy and radiation
Epigenetic modifications play a key role in the patho-physiology of many tumors and the current use of agents targeting epigenetic changes has become a topic of intense interest in cancer research. DNA methyltransferase (DNMT) inhibitors represent a promising class of epigenetic modulators. Research performed yielded promising anti-tumorigenic activity for these agents in vitro and in vivo against a variety of hematologic and solid tumors. These epigenetic modulators cause cell cycle and growth arrest, differentiation and apoptosis. Rationale for combining these agents with cytotoxic therapy or radiation is straightforward since the use of DNMT inhibitor offers greatly improved access for cytotoxic agents or radiation for targeting DNA-protein complex. The positive results obtained with these combined approaches in preclinical cancer models demonstrate the potential impact DNMT inhibitors may have in treatments of different cancer types. Therefore, as the emerging interest in use of DNMT inhibitors as a potential chemo- or radiation sensitizers is constantly increasing, further clinical investigations are inevitable in order to finalize and confirm the consistency of current observations
Oral platelet gel supernatant plus supportive medical treatment versus supportive medical treatment in the management of radiation-induced oral mucositis: a matched explorative active control trial by propensity analysis
OBJECTIVES:: In this active control trial, the rate of radio-induced WHO grade 3/4 oral mucositis and the change in quality of life, assessed by OMWQ-HN, were measured in subjects with head and neck cancer treated by platelet gel supernatant (PGS) and supportive medical treatment versus subjects treated by supportive medical treatment alone. MATERIALS AND METHODS:: Eighty patients with nonmetastatic head and neck cancer underwent curative or adjuvant radiotherapy. All patients underwent supportive medical treatment and/or PGS at the beginning and during radiotherapy. Sixteen patients received PGS in association with supportive medical treatment. To obtain 2 groups virtually randomized for important clinical characteristics subjects were matched, by propensity analysis, with a group of subjects (64 patients) treated with supportive medical treatment alone. RESULTS:: Subjects treated with standard supportive treatment experienced significant higher WHO grade 3/4 toxicity (55%; 35/64) than subjects treated by PGS (13%; 3/16). The reduced toxicity found in PGS group paralleled with the evidence that they developed later symptoms with respect to controls. The Cox proportional hazard model indicated that patients treated with standard supportive medical treatment experienced 2.7-fold increase (hazard ratio=2.7; 95% confidence interval, 1.3-5.7) in the occurrence of WHO grade 3/4 toxicity. PGS group significantly experienced higher quality of life than control groups as measured by OMWQ-HN. A significant decrease in the opioid analgesics usage was found in the PGS group. CONCLUSIONS:: These preliminary data should be interpreted with caution and could serve as a framework around which to design future trials
Mecanismos de transferência de massa na desidratação osmótica de goiaba em soluções de sacarose, sucralose e açúcar invertido.
O objetivo deste trabalho foi avaliar o efeito da concentração de soluções de sacarose, sucralose e açúcar invertido sobre a cinética da desidratação osmótica de pedaços de goiaba. Frações de 1/12 do fruto foram imersas em soluções de sacarose a 0,5 e 0,4 g mL-1, de sacarose a 0,3 g mL-1 + sucralose a 0,2 g L-1 e em xarope de açúcar invertido, a 50 ºC, por 2 h, sob agitação de 60 min. A solução de açúcar invertido promoveu maior perda de água e redução de massa nas amostras de goiaba submetidas à desidratação osmótica. O melhor desempenho foi obtido para o tratamento em solução de sacarose a 0,4 g mL-1, com perda de água e redução de massa semelhantes aos valores obtidos na imersão em solução de sacarose a 0,5 g mL-1 e ganho de sólidos similar ao observado em solução de sacarose a 0,3 g mL-1
First Report on the Benthic Invertebrate Community Associated With a Bronze Naval Ram From the First Punic War: A Proxy of Marine Biodiversity
Historical traces of organisms on the seafloor, such as shells and tubes, constitute the
ecological memory of ancient benthic assemblages and serve as an important resource
for understanding the assembly of modern communities. Archeological shipwrecks are
particularly interesting submerged substrata for both their archeological and biological
implications. For the first time, we studied the species composition and life-history
traits of dominant organisms in the benthic assemblage on a bronze Carthaginian
naval ram, which sank more than two thousand years ago in the Southern Tyrrhenian
Sea. By comparing the species composition of the ram assemblage with those of
the surrounding habitats, we inferred possible colonization patterns for the ram and
discussed the informative role of the shipwreck as a proxy of marine biodiversity.
The ram assemblage was rich in species, including both sessile (bryozoans, serpulid
polychaetes, and few bivalves) and motile (gastropods) species. Sexual reproduction
with free-spawning fertilization and long-duration larvae characterized most species.
The long submersion time of the ram, together with the reproductive strategies, growth
forms, and motility of the dominant species were key factors shaping the community
of the ram. The ram itself offers an archeological artifact of inestimable value, but
our analysis revealed it to be an effective collector of fauna from the surrounding
seabed. The ram community hosted species from a range of nearby natural habitats
(mostly coralligenous, detritic bottoms, and zoosteracean meadows) and thus served
as a proxy for marine biodiversity on the surrounding seabed. We conclude that the
presence of many species on the ram that commonly occur in adjacent habitats of great
environmental value was informative and highlight the important marine biodiversity in
the area of the Aegadian archipelago
Desidratação por imersão-impregnação e secagem por convecção de goiaba.
O objetivo deste trabalho foi avaliar as características físico-químicas e sensoriais de goiabas in natura e submetidas à desidratação por imersão-impregnação e à secagem complementar por convecção, além de avaliar a estabilidade da cor das goiabas secadas após 30, 60 e 90 dias de armazenamento sob refrigeração. Amostras de goiaba foram imersas em soluções de sacarose a 0,4 e 0,5 g mL-1, sacarose a 0,3 g mL-1 + sucralose a 0,2 g L-1, açúcar invertido a 41% (p/p) e açúcar invertido sem diluição. Foram avaliados sólidos solúveis totais, acidez titulável, pH, cor, aroma, aparência, sabor e textura. O teor de sólidos solúveis totais das amostras aumentou linearmente em função do tempo de imersão, sem efeito significativo do tipo de açúcar empregado no preparo da solução. A preservação do teor de ácido cítrico foi mais pronunciada em soluções menos concentradas de sacarose. Amostras secadas não submetidas à desidratação osmótica exibiram maior alteração de cor do que aquelas previamente desidratadas. Soluções de sacarose são mais eficazes na estabilidade da cor do que as de açúcar invertido. As goiabas submetidas à desidratação por imersão-impregnação tiveram boa aceitação sensorial, e aquelas secadas apenas por convecção não foram aceitas pelos provadores
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