Correlation induced phonon softening in low density coupled bilayer systems

We predict a possible phonon softening instability in strongly correlated coupled semiconductor bilayer systems. By studying the plasmon-phonon coupling in coupled bilayer structures, we find that the renormalized acoustic phonon frequency may be softened at a finite wave vector due to many-body local field corrections, particularly in low density systems where correlation effects are strong. We discuss experimental possibilities to search for this predicted phonon softening phenomenon.Comment: 4 pages with 2 figure

Amphipoda (Crustacea) Associados a “Bostrychietum” em uma Área de Manguezal na Região Norte do Estado de São Paulo

O manguezal é um sistema ecológico tropical que se restringe a estreitas faixas costeiras, apresentando condições propícias para alimentação, proteção e reprodução de muitas espécies de animais. Nos manguezais ocorrem importantes associações de macroalgas aderidas em pneumatóforos, rizóforos e troncos das árvores dos gêneros Avicennia L., Rhizophora L. e Laguncularia Gaertn denominadas como “Bostrychietum”. Essas associações incluem cianobactérias e clorofíceas, contudo há imensa dominância de rodofïceas, mais precisamente dos gêneros Bostrychia Mont., Caloglossa (Harv.) G. Martens e Catenella Grev. Os Amphipoda são muito comuns em ambientes de manguezal ao redor do mundo, no entanto não há nenhum estudo faunístico abrangente sobre este grupo para manguezais brasileiros. A área de estudo é uma região de manguezal localizada no Município de São Vicente, Baixada Santista, região norte do estado de São Paulo. A comunidade de “Bostrychietum” é coletada por meio de raspagem dos substratos (pneumatóforos, rizóforos e troncos). Os anfípodes são anestesiados por meio de submerssão em etanol 5-10%. Posteriormente, os anfípodes são triados em laboratório, fixados em etanol 70% e identificados com base em literatura especializada. As amostras de “Bostrychietum” foram depositadas na coleção de algas da Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Campus do Litoral Paulista. Todo o material de Amphipoda está conservado em etanol 70% na coleção do Laboratório de Zoologia do UniFOA. Após a realização do estudo todo o material será depositado em coleções zoológicas de referência. Este projeto está em fase intermediária e parte das amostras já foi analisada. Uma lista preliminar da fauna Amphipoda identificada será apresentada

Energy relaxation of an excited electron gas in quantum wires: many-body electron LO-phonon coupling

We theoretically study energy relaxation via LO-phonon emission in an excited one-dimensional electron gas confined in a GaAs quantum wire structure. We find that the inclusion of phonon renormalization effects in the theory extends the LO-phonon dominated loss regime down to substantially lower temperatures. We show that a simple plasmon-pole approximation works well for this problem, and discuss implications of our results for low temperature electron heating experiments in quantum wires.Comment: 10 pages, RevTex, 4 figures included. Also available at http://www-cmg.physics.umd.edu/~lzheng

World allergy organization guidelines for the assessment and management of anaphylaxis

The illustrated World Allergy Organization (WAO) Anaphylaxis Guidelines were created in response to absence of global guidelines for anaphylaxis. Uniquely, before they were developed, lack of worldwide availability of essentials for the diagnosis and treatment of anaphylaxis was documented. They incorporate contributions from more than 100 allergy/immunology specialists on 6 continents. Recommendations are based on the best evidence available, supported by references published to the end of December 2010. The Guidelines review patient risk factors for severe or fatal anaphylaxis, co-factors that amplify anaphylaxis, and anaphylaxis in vulnerable patients, including pregnant women, infants, the elderly, and those with cardiovascular disease. They focus on the supreme importance of making a prompt clinical diagnosis and on the basic initial treatment that is urgently needed and should be possible even in a low resource environment. This involves having a written emergency protocol and rehearsing it regularly; then, as soon as anaphylaxis is diagnosed, promptly and simultaneously calling for help, injecting epinephrine (adrenaline) intramuscularly, and placing the patient on the back or in a position of comfort with the lower extremities elevated. When indicated, additional critically important steps include administering supplemental oxygen and maintaining the airway, establishing intravenous access and giving fluid resuscitation, and initiating cardiopulmonary resuscitation with continuous chest compressions. Vital signs and cardiorespiratory status should be monitored frequently and regularly (preferably, continuously). The Guidelines briefly review management of anaphylaxis refractory to basic initial treatment. They also emphasize preparation of the patient for self-treatment of anaphylaxis recurrences in the community, confirmation of anaphylaxis triggers, and prevention of recurrences through trigger avoidance and immunomodulation. Novel strategies for dissemination and implementation are summarized. A global agenda for anaphylaxis research is proposed

Curcumin-loaded lipid and polymeric nanocapsules stabilized by nonionic surfactants: An In Vitro and In Vivo antitumor activity on B16-F10 melanoma and macrophage uptake comparative study

Curcumin is a polyphenol obtained from the plant Curcuma longa (called turmeric) that displays several pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial and antitumoral activity, but clinical use has been limited by its poor solubility in water and, consequently, minimal systemic bioavailability. We have therefore formulated the drug into nanocarrier systems in an attempt to improve its therapeutic properties. This study evaluates the effect of intraperitoneally administered nanocapsules containing curcumin on subcutaneous melanoma in mice inoculated with B16-F10 cells, and on the cytotoxicity activity against B16-F10 cells in vitro. Phagocytic uptake of formulations was also evaluated upon incubation with macrophage J774 cells by fluorescence microscopy. Lipid and polymeric nanocapsules were prepared by the phase inversion and nanoprecipitation methods, respectively. The uptake of the lipid nanocapsules prepared using Solutol HS15 was significantly reduced in J774 cells. Curcumin, as free drug or as drug-loaded nanocapsules, was administrated at a dose of 6 mg/kg twice a week for 21 days. Free drug and curcuminloaded nanocapsules significantly reduced tumor volume (P < 0.05 vs. control), but no difference was found in the antitumor activity displayed by lipid and polymeric nanocapsules. This assumption was supported by the in vitro study, in which free curcumin as well as loaded into nanocapsules caused significant reduction of cell viability in a concentration- and time-dependent manner.Fil: Mazzarino, Letícia. Universidade Federal de Santa Catarina; BrasilFil: Silva, Luís F. C.. Universidade Federal de Santa Catarina; BrasilFil: Curta, Juliana C.. Universidade Federal de Santa Catarina; BrasilFil: Licínio, Marley A.. Universidade Federal de Santa Catarina; BrasilFil: Costa, Aline. Universidade Federal de Santa Catarina; BrasilFil: Pacheco, Letícia K.. Universidade Federal de Santa Catarina; BrasilFil: Siqueira, Jarbas M.. Universidade Federal de Santa Catarina; BrasilFil: Martinetti Montanari, Jorge Anibal. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romero, Eder. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Assreuy, Jamil. Universidade Federal de Santa Catarina; BrasilFil: Santos Silva, Maria C.. Universidade Federal de Santa Catarina; BrasilFil: Lemos Senna, Elenara. Universidade Federal de Santa Catarina; Brasi

The relationship between facial skeletal class and expert-rated interpersonal skill: an epidemiological survey on young Italian adults

BACKGROUND: The facial region plays a major role in determining physical attractiveness, so we assessed the hypothesis that the capability of successfully managing interpersonal relationships in young adults might be related to the facial skeletal class. METHODS: 1,014 young subjects applying to the Military Academy of Pozzuoli, Italy, were enrolled and the cephalometric evaluation was performed by calculating the angular relationships between skeletal points localized by the lateral cephalogram of the face, sorting the subjects in three groups corresponding to each major facial skeletal class. Concurrently, the subjects were evaluated by a team of psychiatrists administering the MMPI-2 test followed by a brief colloquium with each candidate, in order to identify those subjects characterized by low skills for managing interpersonal relationships. RESULTS: According to the psychiatric evaluation about 20% of the subjects were considered potentially unable to manage successfully interpersonal relationships (NS). Males displayed an about two-fold increased risk of being NS. No differences were shown in the distribution of the NS male subjects among the three different facial skeletal classes. On the other hand, NS females displayed a different distribution among the three facial skeletal classes, with a trend of about two-fold and four-fold, respectively, for those subjects belonging to classes II and III, respect to those belonging to class I. CONCLUSION: Females may be more sensitive to physical factors determining beauty, such as the facial morphology certainly is. This finding appears to be interesting especially when thinking about possible orthodontic interventions, although further study is certainly needed to confirm these results

Economic analysis of antenatal screening for human T-cell lymphotropic virus type 1 in Brazil: an open access cost-utility model

BACKGROUND: Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes severe diseases, such as aggressive cancer or progressive neurological disease. HTLV-1 affects mainly people in areas with low human development index and can be transmitted from mother to child, primarily through breastfeeding. Refraining from breastfeeding is an effective intervention to reduce the risk of infection in infants. However, HTLV-1 antenatal screening is not offered globally. According to WHO, the scarcity of cost-effectiveness studies is considered one of the major barriers to the implementation of policies to prevent HTLV-1 infection. Therefore, this study aimed to assess the cost-effectiveness of antenatal screening and postnatal interventions to prevent HTLV-1 mother-to-child transmission in Brazil and to develop an open-access, editable, mathematical model that can be used by other countries and regions to assess different scenarios. METHODS: In this cost-utility analysis, we constructed a decision tree and a Markov model to assess the cost-effectiveness of HTLV-1 antenatal screening and postnatal interventions (ie, avoidance of breastfeeding, by suppression of lactation with cabergoline, and provision of formula feed) to reduce transmission. For our model, we used data from Brazil and we took the perspective of the public health-care system to estimate costs. FINDINGS: The implementation of both screening and interventions would result in the prevention of 1039 infections in infants every year in Brazil with an incremental cost-effectiveness ratio (ICER) of US$11 415 per quality-adjusted life-year (QALY). 88$18 107·74 per QALY). HTLV-1 prevalence in pregnant women, the risk of HTLV-1 transmission when breastfeeding lasts for 6 months or more, and the cost of screening tests were the variables with the largest effect on ICER. INTERPRETATION: HTLV-1 antenatal screening is cost-effective in Brazil. An open-access model was developed, and this tool could be used to assess the cost-effectiveness of such policy globally, favouring the implementation of interventions to prevent HTLV-1 mother-to-child transmission worldwide. FUNDING: None. TRANSLATIONS: For the Portuguese and Spanish translations of the abstract see Supplementary Materials section

Effects of new polymorphisms in the bovine myocyte enhancer factor 2D (MEF2D) gene on the expression rates of the longissimus dorsi muscle

Myocyte enhancer factor 2D (MEF2D), a product of the MEF2D gene, belongs to the myocyte enhancer factor 2 (MEF2) protein family which is involved in vertebrate skeletal muscle development and differentiation during myogenesis. The aim of the present study was to search for polymorphisms in the bovine MEF2D gene and to analyze their effect on MEF2D mRNA and on protein expression levels in the longissimus dorsi muscle of Polish Holstein–Friesian cattle. Overall, three novel variations, namely, insertion/deletion g.−818_−814AGCCG and g.−211C<A transversion in the promoter region as well as g.7C<T transition in the 5′untranslated region (5′UTR), were identified by DNA sequencing. A total, 375 unrelated bulls belonging to six different cattle breeds were genotyped, and three combined genotypes (Ins-C-C/Ins-C-C, Del-A-T/Del-A-T and Ins-C-C/Del-A-T) were determined. The frequency of the combined genotype Ins-C-C/Ins-C-C and Del-A-T/Del-A-T was varied between the breeds and the average frequency was 0.521 and 0.037, respectively. Expression analysis showed that the MEF2D variants were highly correlated with MEF2D mRNA and protein levels in the longissimus dorsi muscle of Polish Holstein–Friesian bulls carrying the three different combined genotypes. The highest MEF2D mRNA and protein levels were estimated in the muscle of bulls with the Ins-C-C/Ins-C-C homozygous genotype as compared to the Del-A-T/Del-A-T homozygotes (P < 0.01) and Ins-C-C/Del-A-T heterozygotes (P < 0.05). A preliminary association study showed no significant differences in the carcass quality traits between bulls with various MEF2D combined genotypes in the investigated population of Polish Holstein–Friesian cattle

Acoustic phonon exchange, attractive interactions, and the Wentzel-Bardeen singularity in single-wall nanotubes

We derive the effective low-energy theory for interacting electrons in metallic single-wall carbon nanotubes taking into account acoustic phonon exchange within a continuum elastic description. In many cases, the nanotube can be described as a standard Luttinger liquid with possibly attractive interactions. We predict surprisingly strong attractive interactions for thin nanotubes. Once the tube radius reaches a critical value $R_0 \approx 3.6\pm 1.4$ \AA, the Wentzel-Bardeen singularity is approached, accompanied by strong superconducting fluctuations. The surprisingly large $R_0$ indicates that this singularity could be reached experimentally. We also discuss the conditions for a Peierls transition due to acoustic phonons.Comment: 11 pages, 2 figures, final version to be published in Phys. Rev.