Multifractal fluctuations in zebrafish (Danio rerio) polarization time series.

In this work, we study the polarization time series obtained from experimental observation of a group of zebrafish (Danio rerio) confined in a circular tank. The complex dynamics of the individual trajectory evolution lead to the appearance of multiple characteristic scales. Employing the Multifractal Detrended Fluctuation Analysis (MF-DFA), we found distinct behaviors according to the parameters used. The polarization time series are multifractal at low fish densities and their average scales with ρ - 1 / 4 . On the other hand, they tend to be monofractal, and their average scales with ρ - 1 / 2 for high fish densities. These two regimes overlap at critical density ρ c , suggesting the existence of a phase transition separating them. We also observed that for low densities, the polarization velocity shows a non-Gaussian behavior with heavy tails associated with long-range correlation and becomes Gaussian for high densities, presenting an uncorrelated regime.

Wave transmission and its universal fluctuations in one-dimensional systems with Lévy-like disorder: Schrödinger, Klein-Gordon, and Dirac equations.

We investigate the propagation of waves in one-dimensional systems with Lévy-type disorder. We perform a complete analysis of nonrelativistic and relativistic wave transmission submitted to potential barriers whose width, separation, or both follow Lévy distributions characterized by an exponent 0<α<1. For the first two cases, where one of the parameters is fixed, nonrelativistic and relativistic waves present anomalous localization, 〈T〉∝L^{-α}. However, for the latter case, in which both parameters follow a Lévy distribution, nonrelativistic and relativistic waves present a transition between anomalous and standard localization as the incidence energy increases relative to the barrier height. Moreover, we obtain the localization diagram delimiting anomalous and standard localization regimes, in terms of incidence angle and energy. Finally, we verify that transmission fluctuations, characterized by its standard deviation, are universal, independent of barrier architecture, wave equation type, incidence energy, and angle, further extending earlier studies on electronic localization.

Turbulence Hierarchy and Multifractality in the Integer Quantum Hall Transition.

We offer a new perspective on the problem of characterizing mesoscopic fluctuations in the interplateau regions of the integer quantum Hall transition. We found that longitudinal and transverse conductance fluctuations, generated by varying the external magnetic field within a microscopic model, are multifractal and lead to distributions of conductance increments (magnetoconductance) with heavy tails (intermittency) and signatures of a hierarchical structure (cascade) in the corresponding stochastic process, akin to Kolmogorov's theory of fluid turbulence. We confirm this picture by interpreting the stochastic process of the conductance increments in the framework of H theory, which is a continuous-time stochastic approach that incorporates the basic features of Kolmogorov's theory. The multifractal analysis of the conductance "time series," combined with the H-theory formalism, provides strong support for the overall characterization of mesoscopic fluctuations in the quantum Hall transition as a multifractal stochastic phenomenon with multiscale hierarchy, intermittency, and cascade effects.

Dirac wave transmission in Lévy-disordered systems.

We investigate the propagation of electronic waves described by the Dirac equation subject to a Lévy-type disorder distribution. Our numerical calculations, based on the transfer matrix method, in a system with a distribution of potential barriers show that it presents a phase transition from anomalous to standard to anomalous localization as the incidence energy increases. In contrast, electronic waves described by the Schrödinger equation do not present such transitions. Moreover, we obtain the phase diagram delimiting anomalous and standard localization regimes, in the form of an incidence angle versus incidence energy diagram, and argue that transitions can also be characterized by the behavior of the dispersion of the transmission. We attribute this transition to an abrupt reduction in the transmittance of the system when the incidence angle is higher than a critical value which induces a decrease in the transmission fluctuations.

Piezometric level and electrical conductivity spatiotemporal monitoring as an instrument to design further managed aquifer recharge strategies in a complex estuarial system under anthropogenic pressure.

Recife Metropolitan Region (RMR, NE Brazil) lies over a multi-layered aquifer system located in an estuarial area. The region has experienced fast population growth and repeated droughts in the last three decades, which led to unprecedented anthropogenic pressure on groundwater resources because of intense water pumping. Accordingly, scientific and stakeholder communities have been challenged to ensure the maintenance of sustainable groundwater resource by managing all water cycle. Because controlling pumping rates is difficult due to the large number of illegal wells, the Managed Aquifer Recharge (MAR) strategies are now under consideration. The RMR presents a tropical climate and an annual average rainfall rate of approximately 2450 mm year-1, providing great potential volumes of water to be used for piezometric level recovery. However, MAR implementation requires a detailed and in-depth knowledge of the human-impact on the hydrogeological behavior of the resource over the long-term, in order to find out the most appropriate recharge strategy. Therefore, the present study illustrates how routine data monitoring, i.e., piezometric level and electrical conductivity (EC), in combination with the geological knowledge, may allow proposing further MAR strategies. Two contrasted behaviors were observed in RMR: (i) groundwater level decrease and stable EC in the North and Southernmost areas of Recife; and (ii) stable groundwater level and high/varying EC values next to the estuarial zone. Although aquifers are undergoing over-abstraction, this spatiotemporal heterogeneity suggests that a recharge is possibly locally favored next to the estuarial area of the RMR thanks to hydraulic connections between surface and deep aquifers throughout extended paleo-channels. Thus, based on this typology, MAR implementation through controlled infiltration close to the estuarial area seems to be more appropriated, whereas the direct deep injection appears to be more relevant in more distant zones.

Evaluation of Meiofauna in the Hyporheic Zone of the Beberibe River, Pernambuco, Brazil.

The hyporheic environment is composed of a rich meiofauna that depends on water flow, organic matter, and oxygen. The concentration of meiofauna varies spatially (horizontal and vertical) and temporally. Several processes occur at this interface (groundwater and surface water), including biogeochemical processes involving meiofauna. A study of the hyporheic meiofauna community in the sediments of the Beberibe River, in Brazil, was conducted. Meiofauna attained peak densities of 942.8 organisms/10 cm2, with organisms distributed over six taxa, with 98% of them represented by rotifers, nematodes, and annelids. Density was higher in the dry season with an average of 653.1 organisms/10 cm2, and in more superficial sediments with an average of 739.6 organisms/10 cm2. Greater densities were found in coarser sediment with a higher percentage of organic matter. A river bank filtration (RBF) pilot project has been installed, with good results in the attenuation of contaminants and pathogens.

BAG-1 overexpression attenuates luminal apoptosis in MCF-10A mammary epithelial cells through enhanced RAF-1 activation.

Although the multi-functional, prosurvival protein, Bcl-2-associated anthanogene 1 (BAG-1) is frequently overexpressed in breast cancers, its role in the development or maintenance of the malignant state remains unclear. Here, we have used the established MCF-10A 3-dimensional (3D) model of mammary morphogenesis as a biologically relevant system to determine how BAG-1 expression may influence the development of breast cancer. When cultured in 3D, MCF-10A cells undergo a highly regulated morphogenic program leading to the development of polarized acinar structures containing a central, hollow lumen formed, in part, through the induction of BIM-dependent apoptosis. BAG-1 overexpression resulted in an attenuation of this normal apoptotic program characterized by a significantly increased number of acini with filled lumens-a phenotype commonly observed in ductal carcinoma in situ. BAG-1's effects were associated with an activation of RAF-1-a known binding partner of BAG-1, enhanced signaling through the MAP kinase pathway and a decrease in BIM expression. Reversal of the BAG-1-associated survival phenotype by the mitogen-activated kinase/ERK kinase inhibitor, U0126, implicates the RAF-1-extracellular signal-regulated kinase signaling pathway as a major mediator of BAG-1's effects in this model. As BAG-1 expression is often elevated in preinvasive breast cancers, these findings support a possible role for BAG-1 as an early contributor to the malignant process in the breast.

BAG-1 predicts patient outcome and tamoxifen responsiveness in ER-positive invasive ductal carcinoma of the breast.

BAG-1 (bcl-2-associated athanogene) enhances oestrogen receptor (ER) function and may influence outcome and response to endocrine therapy in breast cancer. We determined relationships between BAG-1 expression, molecular phenotype, response to tamoxifen therapy and outcome in a cohort of breast cancer patients and its influence on tamoxifen sensitivity in MCF-7 breast cancer cells in vitro. Publically available gene expression data sets were analysed to identify relationships between BAG-1 mRNA expression and patient outcome. BAG-1 protein expression was assessed using immunohistochemistry in 292 patients with invasive ductal carcinoma and correlated with clinicopathological variables, therapeutic response and disease outcome. BAG-1-overexpressing MCF-7 cells were treated with antioestrogens to assess its effects on cell proliferation. Gene expression data demonstrated a consistent association between high BAG-1 mRNA and improved survival. In ER+ cancer (n=189), a high nuclear BAG-1 expression independently predicted improved outcome for local recurrence (P=0.0464), distant metastases (P=0.0435), death from breast cancer (P=0.009, hazards ratio 0.29, 95% CI: 0.114-0.735) and improved outcome in tamoxifen-treated patients (n=107; P=0.0191). BAG-1 overexpression in MCF-7 cells augmented antioestrogen-induced growth arrest. A high BAG-1 expression predicts improved patient outcome in ER+ breast carcinoma. This may reflect both a better definition of the hormone-responsive phenotype and a concurrent increased sensitivity to tamoxifen.

Lower extremity iatrogenic nerve injury due to compression during intraabdominal surgery.

BACKGROUND: latrogenic nerve injury due to poor positioning and external compression is a common surgical complication. However, sciatic neuropathy from external compression and femoral nerve injury after self-retaining retraction are less-published complications. METHODS: Surgical Morbidity and Mortality Reports from 1986 through 1995 were reviewed to identify femoral and sciatic neuropathies following intraabdominal vascular and general surgeries. RESULTS: Two sciatic and 5 femoral neuropathies were reported, an incidence of approximately 0.17% of abdominal cases. Sciatic injuries were attributed to external compression, whereas femoral neuropathies were due to compression by self-retaining retraction. The 3 female and 4 male patients had a mean age of 53.4 years, and no patient had a prior history of peripheral neuropathy. Mean operating time for sciatic injuries was 8.2 hours, versus 4.3 hours for femoral neuropathies. Both patients with sciatic neuropathy had complete resolution of symptoms, compared with 1 femoral neuropathy patient. Two femoral neuropathies were permanent, 1 had partial resolution and 1 had improvement at 4 months but was lost to follow-up. CONCLUSIONS: Sciatic and femoral compression neuropathies are rare but serious complications of abdominal surgery. When retracting in the deep pelvis, consideration should be given to using small, well-padded retractor blades and repositioning these regularly. Prevention of sciatic nerve compression requires careful padding of the table surface, especially for longer cases.

Gamma/delta T cells from tolerized alpha/beta-TCR-deficient mice antigen specifically inhibit contact sensitivity in vivo and IFN-gamma production in vitro.

Contact sensitivity (CS) responses to reactive hapten antigens (Ag), such as picryl chloride, are classical examples of T-cell-mediated immune responses in vivo. There is also abundant evidence that T cells exposed in vivo to high intravenous doses of Ag can downregulate CS (high-dose Ag tolerance). To clarify cell types that effect CS and mediate its downregulation, we have studied CS in mice congenitally deficient in alpha/beta T cells (alpha-/- mice). We show that alpha-/- mice cannot mount CS, implicating alpha/beta T cells as critical CS effector cells. However, after high-dose Ag tolerization, these alpha-/- mice can downregulate alpha/beta CS effector cells adoptively transferred to them. The active cells in tolerized alpha-/- mice are gamma/delta TCR+ cells which downregulate CS effector alpha/beta T cells Ag-specifically upon adoptive cell transfer. Moreover, gamma/delta cells can Ag-specifically downregulate IFN-gamma production by CS effector cells in vitro. These findings establish that gamma/delta T cells are not CS effector cells but downregulate CS, in agreement with recent reports that gamma/delta T cells downregulate IgE responses.

The role of the pharmacy department in the prevention of adverse drug events: a survey of current practices.

Adverse drug events have received a great deal of publicity during he past several years. The tracking and prevention of medication errors is an important part of ensuring quality care for patients. The American Society of Health-System Pharmacists, and the Institute For Safe Medication Practices are two groups who have published recommendations on the prevention of adverse drug events in hospitals. This study provides an informative analysis of the status of implementation of these recommendations by hospital pharmacists in Louisiana.

Gamma delta T cells from tolerized alpha beta T cell receptor (TCR)-deficient mice inhibit contact sensitivity-effector T cells in vivo, and their interferon-gamma production in vitro.

Contact sensitivity (CS) responses to reactive hapten Ag, such as picryl chloride (PCl) or oxazolone (OX), are classical examples of T cell-mediated immune responses in vivo that are clearly subject to multifaceted regulation. There is abundant evidence that downregulation of CS may be mediated by T cells exposed to high doses of Ag. This is termed high dose Ag tolerance. To clarify the T cell types that effect CS responses and mediate their downregulation, we have undertaken studies of CS in mice congenitally deficient in specific subsets of lymphocytes. The first such studies, using alpha beta T cell-deficient (TCR alpha -/-) mice, are presented here. The results clearly show that TCR alpha -/- mice cannot mount CS, implicating alpha beta T cells as the critical CS-effector cells. However, TCR alpha -/- mice can, after high dose tolerance, downregulate alpha +/+ CS-effector T cells adoptively transferred into them. By mixing ex vivo and then adoptive cell transfers in vivo, the active downregulatory cells in tolerized alpha -/- mice are shown to include gamma delta TCR+ cells that also can downregulate interferon-gamma production by the targeted CS-effector cells in vitro. Downregulation by gamma delta cells showed specificity for hapten, but was not restricted by the MHC. Together, these findings establish that gamma delta T cells cannot fulfill CS-effector functions performed by alpha beta T cells, but may fulfill an Ag-specific downregulatory role that may be directly comparable to reports of Ag-specific downregulation of IgE antibody responses by gamma delta T cells. Comparisons are likewise considered with downregulation by gamma delta T cells occurring in immune responses to pathogens, tumors, and allografts, and in systemic autoimmunity.

Reliability of a Greek translation of the Life Satisfaction Index.

Scores on a Greek translation of the Life Satisfaction Index were correlated .95 with scores on the English version for a sample of 36 bilingual Greek university women. The internal reliability of the Greek translation was estimated by a coefficient alpha of .78. Scores were significantly correlated -.51 with those on a previously published Greek translation of the Revised UCLA Loneliness Scale and -.37 with Social loneliness and -.40 with Emotional loneliness. This same pattern of correlations was found when the English version of these two tests was completed by university men and women in the USA. We concluded, therefore, the Greek translation of the Life Satisfaction Index is sufficiently reliable to warrant further use in research in Greece.

Reliability data for a Greek translation of the Revised UCLA Loneliness Scale: comparisons with data from the USA.

A Greek translation of the Revised UCLA Loneliness Scale was internally reliable (alpha = .89), after eliminating Item 4, and significantly correlated with the English version (r = .94) for a sample of bilingual students. Weiss's distinction between social loneliness and emotional loneliness was also reliably identified in the Greek translation. Loneliness scores in Greece were significantly higher than in the USA. The translation seems to be sufficiently reliable to warrant further use with Greek individuals.

Test-retest reliability of the Revised Self-monitoring Scale over a two-year period.

The Revised Self-monitoring Scale of Lennox and Wolfe was administered to 83 staff nurses in 1987 and in 1989 as part of on-going research. Test-retest correlations were: for Factor A, Ability to Modify Self-presentation, .53, for Factor B, Sensitivity to the Expressive Behavior of Others, .52, and for the Total Self-monitoring Score .55. These scores were sufficiently strong to warrant continued, but cautious use of this revised test.

Once daily therapy for streptococcal pharyngitis with cefadroxil.

To determine if a single daily dose of cefadroxil would be effective in the treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis, 196 patients with GABHS pharyngitis were randomly assigned to receive either penicillin V 250 mg three times daily or cefadroxil 30 mg/kg once daily, for 10 days. Outcome was measured by the ability to isolate GABHS from the upper respiratory tract 18 to 24 hours after the onset of therapy, the impact on the clinical course, and the bacteriologic treatment failure rate. There was no significant difference in the number of patients in the cefadroxil and penicillin V treatment groups with throat cultures positive for GABHS at the 18 to 24-hour follow-up visit (0% and 2%, respectively), and the clinical responses of the patients in the two treatment groups were similar. Of the 99 patients in the three times daily penicillin V group, six (6%) had strains of GABHS isolated on one of the follow-up cultures that were identical to the strains isolated from their initial throat cultures and were considered to have bacteriologic treatment failures. Of the 96 patients in the once daily cefadroxil group, two (2%) were considered to have bacteriologic treatment failures. A single daily dose of cefadroxil appears to be as effective in the treatment of GABHS pharyngitis in this population as penicillin V given three times daily.

Antigen detection test for streptococcal pharyngitis: evaluation of sensitivity with respect to true infections.

The clinical significance of false-negative results on antigen detection tests for group A beta-hemolytic streptococcal (GABHS) pharyngitis (negative test results and positive culture) has yet to be determined. We recently compared the Culturette Brand Ten-Minute Group A Strep ID Kit with blood agar cultures in 313 patients with pharyngitis, 257 (82%) of whom had positive throat cultures for GABHS. The Culturette Brand test had a sensitivity of 88%, specificity of 96%, a positive predictive value of 99%, and negative predictive value of 64%. More than half of the false-negative Culturette Brand test results occurred in children with less than 10 GABHS colonies on throat culture (1+ culture). When these 1+ cultures were not considered positive, the sensitivity of the Culturette Brand test was 93%. The sensitivity of the Culturette Brand test increased with an increased degree of positivity of the corresponding throat culture. Of the 31 children with false-negative Culturette Brand test results, 14 (45%) had a significant streptococcal antibody response; of the 224 children with true-positive Culturette Brand test results (positive test results and positive culture) from whom serologic data were available, 114 (51%) had a significant streptococcal antibody response. This difference is not statistically significant. These findings suggest that almost half of patients with false-negative results on antigen detection tests for GABHS pharyngitis have true infections (positive culture and antibody rise) and are not merely streptococcal carriers.