Symmetries, Large Leptonic Mixing and a Fourth Generation

We show that large leptonic mixing occurs most naturally in the framework of the Sandard Model just by adding a fourth generation. One can then construct a small $Z_4$ discrete symmetry, instead of the large $S_{4L}\times S_{4R}$, which requires that the neutrino as well as the charged lepton mass matrices be proportional to a $4\times 4$ democratic mass matrix, where all entries are equal to unity. Without considering the see-saw mechanism, or other more elaborate extensions of the SM, and contrary to the case with only 3 generations, large leptonic mixing is obtained when the symmetry is broken.Comment: 6 pages, ReVTeX, no figure

CPT, T, and Lorentz Violation in Neutral-Meson Oscillations

Tests of CPT and Lorentz symmetry using neutral-meson oscillations are studied within a formalism that allows for indirect CPT and T violation of arbitrary size and is independent of phase conventions. The analysis is particularly appropriate for studies of CPT and T violation in oscillations of the heavy neutral mesons D, B_d, and B_s. The general Lorentz- and CPT-breaking standard-model extension is used to derive an expression for the parameter for CPT violation. It varies in a prescribed way with the magnitude and orientation of the meson momentum and consequently also with sidereal time. Decay probabilities are presented for both uncorrelated and correlated mesons, and some implications for experiments are discussed.Comment: 11 pages, references added, accepted in Physical Review

Differential tolerance of sugarcane cultivars to clomazone

Weed control is one of the most relevant costs of sugarcane production. If weeds are not controlled at the right time, the productivity and longevity of sugarcane plantations are reduced. In this crop, chemical control is the most used method, since it is efficient and it has a lower cost. Differentiated tolerance of sugarcane cultivars to the herbicide clomazone has been observed in the fields. However, there is no scientific evidence of this effect on the productivity of crops. This study evaluated the effects of clomazone on three sugarcane cultivars (RB966928, RB93579 and RB867515). Herbicide application was performed 40 days after the emergence of sugarcane plants and 7, 14, 21 and 28 days after the application, the toxicity caused by the herbicide in the culture was evaluated through grades ranging from 0 (no toxicity) to 100 (plant death). The harvest was performed 580 days after the herbicide application. On this occasion, the length and diameter of the stem, number of tillers, tons of stems per hectare, total soluble solids of the juice, sucrose of the juice, apparent purity of the juice, sugarcane fiber, reducing sugars and total recoverable sugars were evaluated. The differential tolerance among sugarcane cultivars in response to clomazone application in the early stages of crop development was confirmed. Nevertheless, in all cultivars, the symptoms of intoxication disappeared over time and did not reflect on crop productivity. It was concluded that plant control in the sugarcane crop with clomazone, following the recommendation of the manufacturer, does not interfere negatively in the growth, development and productivity of the crop.As plantas daninhas, se não controladas no momento adequado, reduzem a produtividade e longevidade dos canaviais. Nesta cultura, o método químico de controle das plantas daninhas, por ser eficiente e de menor custo, é o mais utilizado. No campo, tem-se observado tolerância diferenciada de cultivares de cana-de-açúcar ao herbicida clomazone. Contudo, não existe comprovação científica desse efeito sobre a produtividade dos cultivares. Neste trabalho foram avaliados os efeitos do clomazone em três cultivares de cana-de-açúcar (RB966928, RB93579 e RB867515). A aplicação do herbicida foi feita aos 40 dias após emergência das plantas de cana, e aos 7, 14, 21 e 28 dias após a aplicação foram avaliadas as intoxicações causadas pelo herbicida na cultura, atribuindo-se notas que variaram de 0 (ausência de intoxicação) até 100 (morte das plantas). Aos 580 dias após a aplicação foi realizada a colheita da cultura. Nessa ocasião, foram avaliados o comprimento e diâmetro do colmo, número de perfilho, tonelada de colmos por hectare, sólidos solúveis totais do caldo, sacarose do caldo, pureza aparente do caldo, fibra da cana, açúcares redutores e açúcares totais recuperáveis. Foi confirmada a tolerância diferenciada entre cultivares de cana-de-açúcar à aplicação do clomazone no início de desenvolvimento da cultura. Entretanto, os sintomas de intoxicação desapareceram ao longo do tempo e não refletiram na produtividade da cultura. Concluiu-se que o controle de plantas na cultura da cana-de-açúcar com o clomazone, seguindo a recomendação do fabricante, não interfere no crescimento, no desenvolvimento e na produtividade da cultura

Histopathological Analysis Of Gangliosides Use In Peripheral Nerve Regeneration After Axonotmesis In Rats

Purpose: To analyze the action of gangliosides in peripheral nerve regeneration in the sciatic nerve of the rat. Methods: The sample was composed of 96 male Wistar rats. The animals were anaesthetized and, after identification of the anaesthesic plane, an incision was made in the posterior region of the thigh, followed by skin and muscle divulsion. The right sciatic nerve was isolated and compressed for 2 minutes. Continuous suture of the skin was performed. The animals were randomly divided into two groups: the experimental group (EG), which received subcutaneous injection of gangliosides, and the control group (CG), which received saline solution (0.9%) to mimic the effects of drug administration. Results: No differences were observed between the experimental and control groups evaluated on the eighth day of observation. At 15 and 30 days the EG showed an decrease in Schwann cell activity and an apparent improvement in fibre organization; at 60 days, there was a slight presence of Schwann cells in the endoneural space and the fibres were organized, indicating nerve regeneration. At 15 and 30 days, the level of cell reaction in the CG had diminished, but there were many cells with cytoplasm in activity and in mitosis; at 60 days, hyperplastic Schwann cells and mitotic activity were again observed, as well as nerve regeneration, but to a lesser extent than in the EG. Conclusion: The administration of exogenous gangliosides seems to improve nerve regeneration.234364371Vasconcelos, B.C., Gay Escoda, C., Vasconcellos, R.J., Neves, R.F., Conduction velocity of the rabbit facial nerve: A noninvasive functional evaluation (2003) Pesqui Odontol Bras, 17, pp. 126-131De Medinacelli, L., Freed, W.J., Wyatt, R.J., An index of the functional condition of rat sciatic nerve based on measurements made from walking tracks (1982) Exp Neur, 77, pp. 6634-6643Nachemson, A.K., Lundborg, G., Myrhage, R., Rank, F., Nerve regeneration and pharmacological suppression of the scar reaction at the suture site (1985) Scand J Plast Reconstr Surg, 19, pp. 255-260Danielsen, N., Varon, S., Characterization of neurotrophic activity in the silicone chamber model for nerve regeneration (1995) J Reconstr Microsurg, 11, pp. 231-235Catan, F.G., Pastorello, A., Siliprandi, R., Savastano, M., Molinari, G., Brain cortex gangliosides and Na+, K+)-ATPase system of the stria vascularis in the guinea pig (1981) Acta Otolaryngol, 92, pp. 433-437Cunha, M.T.R., Silva, A.R., Fenelon, S.B., Comparision of nerve integration after segmentar resection versus epineural burying in crushed rat sciatic nerves (1997) Acta Cir Bras, 4, pp. 221-225Chen, Z.Y., Chai, Y.F., Cao, L., Lu, C.L., He, C., Glial cell line-derived neurotrophic factor enhances axonal regeneration following sciatic nerve transection in adult rats (2001) Brain Res, 2, pp. 272-276Abreu, A.A.N., Wei, T.H., Zumiotti, A.V., Avaliação dos gangliosídeos na regeneração nervosa em ratos. (2002) Rev Bras Ortop, 37, pp. 39-44Neto, J.C., Vasconcelos, B.C., Sobral, A.P., da Silva Jr, V.A., Nogueira, R.V., Clinical and histopathologic study of the use of gangliosides for nerve regeneration in rats after axonotmesis (2007) J Oral Maxillofac Surg, 65, pp. 870-874de Ruiter, G.C., Spinner, R.J., Alaid, A.O., Koch, A.J., Wang, H., Malessy, M.J., Currier, B.L., Windebank, A.J., Two-dimensional digital video ankle motion analysis for assessment of function in the rat sciatic nerve model (2007) J Peripher Nerv Syst, 12, pp. 216-222Schmalbruch, H., Fiber composition of the sciatic nerve (1986) Anat Rec, 215 (1), pp. 71-81Apley, A.G., Teaching techniques and training methods in orthopaedics (1966) Proc R Soc Med, 59 (2), p. 117Kline, D.G., Kim, D., Midha, R., Harsh, C., Tiel, R., Management and results of sciatic nerve injuries: A 24-year experience (1998) J Neurosurg, 89, pp. 13-23Gomes AC, Vasconcelos BC, de Oliveira e Silva ED, da Silva LC. Lingual nerve damage after mandibular third molar surgery: a randomized clinical trial. J Oral Maxillofac Surg. 2005;63:1443-6Horch, H.W., Krüttgen, A., Portbury, S.D., Katz, L.C., Destabilization of cortical dendrites and spines by BDNF (1999) Neuron, 23 (2), pp. 353-364Tos, P., Ronchi, G., Nicolino, S., Audisio, C., Raimondo, S., Fornaro, M., Battiston, B., Geuna, S., Employment of the mouse median nerve model for the experimental assessment of peripheral nerve regeneration (2008) J Neurosci Methods, 169 (1), pp. 119-127Graff-Radford, S.B., Evans, R.W., Lingual nerve injury (2003) Headache, 43, pp. 975-983Montovani, J.C., Prado, R.G., Bacchi, C.E., Experimental surgery of the facial nerve: Evaluation of the intraperitoneal use of exogenous gangliosides (1995) Rev Laryngol Otol Rhinol, 116, pp. 163-167Langone, F., Silva, C.F., Exogenous ganglioside stimulation of axonal regeneration after new transsection and intubation repair (1990) Braz J Med Biol, 23, pp. 823-826Lainetti, R.D., Silva, C.F., Local addition of monosialoganglioside GM1 stimulates peripheral axon regeneration in vivo (1993) Braz J Med Biol Res, 26, pp. 841-845Sobeski, J.K., Kerns, J.M., Safanda, J.F., Shott, S., Gonzalez, M.H., Functional and structural effects of GM-1 ganglioside treatment on peripheral nerve grafting in the rat (2001) Microsurgery, 21, pp. 108-115Amico-Roxas, M., Caruso, A., Trombadore, S., Scifo, R., Scapagnini, U., Gangliosides antinociceptive effects in rodents (1984) Arch Int Pharmacodyn Ther, 272 (1), pp. 103-117(1978) United Nations Educational, Scientific and Culture Organization, , http://portal.unesco.org/en/ev.php-URL_ID=29008&URL_DO=DO_TOPIC&URL_SECTION=201.html, Universal Declaration of Animal Rights, Bruxelles. Available from UR

Postnatal development of rats exposed to fluoxetine or venlafaxine during the third week of pregnancy

The aim of the present study was to compare the toxic effects of fluoxetine (F) (8 and 16 mg/kg) and venlafaxine (V) (40 and 80 mg/kg) administered during the third week of pregnancy on early development of rats. Both antidepressants were administered by gavage on pregnancy days 15 to 20 to groups of 10 to 12 animals each. Duration of gestation, food and water consumption, number of live pups and birth weight were recorded. Litters were culled to six pups at birth (day 1) and followed for growth until weaning (day 25). On day 60, a male and a female from each litter were injected with the 5-HT1 agonist, 5-methoxy-N,N-dimethyltryptamine (6 mg/kg, ip) and the serotonergic syndrome was graded. Fluoxetine but not venlafaxine reduced the duration of pregnancy when compared to the control (C) group (F = 21.1 days and C = 21.6 days, mean, P<0.02; maximum = 22 days and minimum = 21 days in both groups). The highest doses of both fluoxetine, 16 mg/kg (F16), and venlafaxine, 80 mg/kg (V80), reduced the food intake of pregnant rats, resulting in different rates of body weight gain during treatment (from pregnancy day 15 to day 20): F16 = 29.0 g, V80 = 28.7 g vs C = 39.5 g (median). Birth weight was influenced by treatment and sex (P<0.05; two-way ANOVA). Both doses of fluoxetine or venlafaxine reduced the body weight of litters; however, the body weight of litters from treated dams was equal to the weight of control litters by the time of weaning. At weaning there was no significant difference in weight between sexes. There was no difference among groups in number of live pups at birth, stillbirths, mortality during the lactation period or in the manifestation of serotonergic syndrome in adult rats. The occurrence of low birth weight among pups born to dams which did not show reduced food ingestion or reduction of body weight gain during treatment with lower doses of fluoxetine or venlafaxine suggests that these drugs may have a deleterious effect on prenatal development when administered during pregnancy. In addition, fluoxetine slightly but significantly affected the duration of pregnancy (about half a day), an effect not observed in the venlafaxine-treated groups.Universidade Federal FluminenseUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

A Case Study in Identifying Gaps and Developing a Common Code of Ethics for Commercial Banks in Sri Lanka

AbstractGrowing corrupt behavior of employees and its negative consequences to the organization, economy and the society at large, had become a global issue for many years. The stability of a county’s economy depends on the stability of its Financial Sector, mainly on its Banking Industry. Banks do business with public money, and depend heavily on public trust for its stability. Creating and maintaining an ‘ethical image’ through ethical management and ethical behavior of employees are critical to win public trust and confidence. Thus, banks’ operations are governed by many statutory and mandatory rules. The Central Bank of Sri Lanka had issued a mandatory Code of Conduct for Licensed Banks (Customer Charter - 2007), to guide them in customer transactions, to protect the customers. In addition, banks have individual Codes of Ethics, which specify their ethical policies and values, and guide the employees’ behavior at work. However, the Codes differ from bank to bank, depending on each banks’ ethical orientation and priorities. This Case Study is a comparative analysis of the Codes of Ethics of Licensed Commercial banks (LCBs) operating in Sri Lanka, comparing against globally accepted moral standards of Codes, recognized in scholarly literature. The study exposed many gaps in the Codes of LCBs: inadequacy of ethical principles and rules, less clarity of the ethical rules available, less focus on ethical principles and rules, congested contents with other operational rules etc. Authors proposed a common Code of Ethics, based on universally acceptable ethical standards, for the LCBs operating in Sri Lanka, to evaluate the intensity of ethical standards of their Code of Ethics. The study identified 12 universally acceptable moral principles and developed a measure which could be used as a guide by the banks, to self-evaluate the ethical quality of their Codes of Ethics. This research is new in the Sri Lankan banking industry, Thus, have original value and adds many valuable managerial implications.Keywords: Common Code of Ethics, Universal Standards, Sri Lankan Commercial Banks

Non-Z2\mathbb{Z}_{2} symmetric braneworlds in scalar tensorial gravity

We obtain, via the Gauss-Codazzi formalism, the expression of the effective Einstein-Brans-Dicke projected equations in a non-$\mathbb{Z}_{2}$ symmetric braneworld scenario which presents hybrid compactification. It is shown that the functional form of such equations resembles the one in the Einstein's case, except by the fact that they bring extra informations in the context of exotic compactifications.Comment: 12 pages, LATEX file, no figures. Accepted for publication in the European Physical Journal

Assessment of the Existing Level of Pollution due to Selected Heavy Metals in Surface Sediments of Negombo Lagoon, Sri Lanka

This study was conducted to evaluate the existing level of pollution with respect to selected heavy metals (Fe, Mn, As, Pb, Zn and Cu) in surficial sediments of Negombo Lagoon in Sri Lanka, which is constantly exposed to diverse human induced stresses. Additionally, this study investigated the application of X-ray fluorescence spectroscopy and pollution indices in assessment of heavy metal pollution. A total of 32 surface sediment samples covering the entire lagoon were collected using a grabber sampler and the concentrations of selected heavy metals were analysed using X-ray fluorescence spectroscopy. Furthermore, the concentrations of these heavy metals were used to assess the pollution status of the Negombo Lagoon by an integrated approach using pollution indices such as Enrichment Factor, Geoaccumulation Index and Pollution Load Index. The concentrations of the heavy metals studied were compared with the Canadian sediment quality guidelines which indicate the toxic concentrations of pollutants in sediments that affect aquatic organisms. The mean concentrations of all the heavy metals analysed were higher than the Threshold Effect Level (TEL) while the mean concentration of Arsenic (As) is greater than the Probable Effect Level (PEL) stated in the sediment quality guidelines. The results of Enrichment Factor revealed that the entire Negombo Lagoon is severely enriched by As, while minor enrichment of Copper (Cu) and Zinc (Zn) was observed across the lagoon, suggesting the contribution of anthropogenic sources for metal pollution in surface sediments of the lagoon. Moreover, the calculated Geoaccumulation Indices of the metals studied confirmed that surface sediments of the entire Negombo Lagoon is contaminated with As, Zn and Cu, emphasizing the influence of anthropogenic contamination. However, the concentrations of Manganese (Mn), Iron (Fe) and Lead (Pb) in surface sediments were within their natural range, evidently showing terrigenous origin. The calculated Pollution Load Index revealed that the Negombo Lagoon is considerably polluted by the heavy metals investigated. In conclusion, Arsenic (As) has shown a greater contribution to metal pollution while Zn and Cu were identified as minor enriched contaminants in surface sediments of Negombo Lagoon. The results of this study, while being useful as a reference data base, emphasized the need of effective management strategies for conservation of the lagoon before the pollution level becomes irreversible.Keywords: Heavy metal, Pollution, Coastal contamination, Surface sediments, X-ray fluorescenc

Reduction of blood nitric oxide levels is associated with clinical improvement of the chronic pelvic pain related to endometriosis

The objective of this prospective study was to determine the plasma levels of nitric oxide (NO) in women with chronic pelvic pain secondary to endometriosis (n=24) and abdominal myofascial pain syndrome (n=16). NO levels were measured in plasma collected before and 1 month after treatment. Pretreatment NO levels (μM) were lower in healthy volunteers (47.0±12.7) than in women with myofascial pain (64.2±5.0, P=0.01) or endometriosis (99.5±12.9, P<0.0001). After treatment, plasma NO levels were reduced only in the endometriosis group (99.5±12.9 vs 61.6±5.9, P=0.002). A correlation between reduction of pain intensity and reduction of NO level was observed in the endometriosis group [correlation = 0.67 (95%CI = 0.35 to 0.85), P<0.0001]. Reduction of NO levels was associated with an increase of pain threshold in this group [correlation = -0.53 (-0.78 to -0.14), P<0.0001]. NO levels appeared elevated in women with chronic pelvic pain diagnosed as secondary to endometriosis, and were directly associated with reduction in pain intensity and increase in pain threshold after treatment. Further studies are needed to investigate the role of NO in the pathophysiology of pain in women with endometriosis and its eventual association with central sensitization.484363369CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçã