Endodontic Chelators Induce Nitric Oxide Expression by Murine-cultured Macrophages

Introduction: Endodontic chelators may extrude to apical tissues during instrumentation activating cellular events on periapical tissues. This study assessed in vitro the expression of nitric oxide (NO) concentrations by murine peritoneal macrophages after contact with MTAD (Dentsply/Tulsa, Tulsa, OK), Tetraclean (Ogna Laboratori Farmaceutici, Muggio, Italy), Smear Clear (Sybron Endo, Orange, CA), and EDTA (Biodinamica, Ibipora, PR, Brazil). Methods: Macrophage cells were obtained from Swiss mice after peritoneal lavage. Chelators were diluted in distilled water obtaining 12 concentrations, and MTT assay identified the concentrations, per group, displaying the highest cell viability (analysis of variance, p < 0.01). Selected concentrations were tested for NO expression using Griess reaction. Culture medium and lipopolysaccharide (LPS) were used as controls. Results: Analysis of variance and Tukey tests showed that all chelators displayed elevated NO concentrations compared with the negative control (p < 0.01). MTAD induced the lowest NO expression, followed by Tetraclean, EDTA, and Smear Clear. No difference was observed between MTAD and Tetraclean (p > 0.01), Tetraclean and EDTA (p > 0.01), and EDTA and Smear Clear (p > 0.01). LPS ranked similar to both EDTA and Smear Clear (p > 0.01). Conclusion: The tested endodontic chelators displayed severe proinflammatory effects on murine-cultured macrophages. Citric acid-based solutions induce lower No release than EDTA-based irrigants. (J Endod 2009;35:824-828)

On site flotation for recovering polluted aquatic systems: is it a feasible solution for a Brazilian urban river?

Pinheiros River (Brazil) plays a pivotal role in supplying water to Billings Reservoir, which presents multiple uses (human drinking, energy generation, irrigation, navigation, fishing and leisure) An intense monitoring program was performed during the years 2007 and 2008 to find out whether on site flotation is a feasible solution or not for improving the water quality of this urban river, attenuating the pollutants load caused by the water pumping to the reservoir (approximately 10 m(3)s(-1)) The monitoring of 18 variables (13,429 laboratorial analysis during the period of 490 days), suggested that despite the convenience of the on site approach for water treatment, especially for rivers located in fully urbanized areas, the flotation system is not enough itself to recover Pinheiros River water quality, given the several constraints that apply Total phosphorus removal was high in percentage terms (about 90%), although the remaining concentrations were not so low (mean of 0 05 mg L(-1)) The removal efficiency of some variables was insufficient, leading to high final mean concentrations of metals [e g aluminium (0 29 mg L(-1)), chromium (0 02 mg L(-1)) and iron (1 1 mg L(-1))] as well as nitrogen-ammonia (25 8 mg L(-1)) and total suspended solids (18 mg L(-1)) in the treated water

Seismic activity triggered by water wells in the Parana Basin, Brazil

Triggered seismicity is commonly associated with deep water reservoirs or injection wells where water is injected at high pressure into the reservoir rock. However, earth tremors related solely to the opening of groundwater wells are extremely rare. Here we present a clear case of seismicity induced by pore-pressure changes following the drilling of water wells that exploit a confined aquifer in the intracratonic Parana Basin of southeastern Brazil. Since 2004, shallow seismic activity, with magnitudes up to 2.9 and intensities V MM, has been observed near deep wells (120-200 m) that were drilled in early 2003 near the town of Bebedouro. The wells were drilled for irrigation purposes, cross a sandstone layer about 60-80 m thick and extract water from a confined aquifer in fractured zones between basalt flow layers. Seismic activity, mainly event swarms, has occurred yearly since 2004, mostly during the rainy season when the wells are not pumped. During the dry season when the wells are pumped almost continuously, the activity is very low. A seismographic network, installed in March 2005, has located more than 2000 microearthquakes. The events are less than 1 km deep (mostly within the 0.5 km thick basalt layer) and cover an area roughly 1.5 km x 5 km across. The seismicity generally starts in a small area and expands to larger distances with an equivalent hydraulic diffusivity ranging from 0.06 to 0.6 m(2)/s. Geophysical and geothermal logging of several wells in the area showed that water from the shallow sandstone aquifer enters the well at the top and usually forms waterfalls. The waterfalls flow down the sides of the wells and feed the confined, fractured aquifer in the basalt layer at the bottom. Two seismic areas are observed: the main area surrounds several wells that are pumped continuously during the dry season, and a second area near another well (about 10 km from the first area) that is not used for irrigation and not pumped regularly. The main area displays cyclic annual activity, but the second area does not. We explain the earthquake swarms as being triggered by pore pressure diffusion in the fractured basalt layer due to additional pressure from the newly connected surface aquifer. This reaches critically prestressed areas up to a few kilometers away from the wells. During periods of continuous pumping, the reduction of pore pressure in the confined aquifer stops the seismic activity. Our study suggests that this kind of activity may be more common than previously thought and implies that many other cases of small tremors associated with the drilling of water wells may have gone unnoticed.

Induced seismicity in the Castarthao reservoir, NE Brazil - Preliminary results

The Castanhao reservoir was built in the state of Ceara, a dry region in Northeastern Brazil, to regulate the flow of the Jaguaribe River, for irrigation, and for power generation. It is an earth-filled dam, 60 m high, with a water capacity of 4.5 x 10(9) m(3). The seismicity in the area has been monitored since 1998, with a few interruptions, using one analog or one digital station and, during a few periods, a three-station network. The first earthquakes likely to be induced events were detected in 2003, when the water level was about 20 in high. In early 2004 a very heavy rainfall season quickly filled the reservoir. Shortly after, an increase in the seismic activity occurred and many micro-earthquakes were recorded. We suggest that this activity resulted from an increase in pore pressure due to undrained response. Therefore, we may classify this cluster of microearthquakes as ""initial seismicity."" We deployed a network with four analog stations in the area, following this activity, to determine the epicentral zone. At least three epicentral areas under the reservoir were detected. The spatio-temporal analysis of the available data revealed that the seismicity occurs in clusters and that these were activated at different periods. We identified four sets of faults (N-S-, E-W-, NW-SE-, and NE-SW-oriented), some of which moved in shallow crustal levels and as recently as the Quaternary (1.8 Ma). Under the present-day stress regime, the last two sets moved as strike-slip structures. We suggest a possible correlation between dormant faults and the observed induced seismicity. (c) 2008 Elsevier B.V. All rights reserved.

High-power diode laser in the disinfection in depth of the root canal dentin

Objective. The objective of this study was to evaluate the disinfection degree of dentine caused by the use of diode laser after biomechanical procedures. Study design. Thirty teeth were sectioned and roots were autoclaved and incubated for 4 weeks with a suspension of Enterococcus faecalis. The specimens were randomly divided into 3 groups (n = 10): G1, instrumented with rotary files, irrigated with 0.5% sodium hypochlorite and 17% EDTA-T, and then irradiated by 830-nm diode laser at 3 W; G2, the same procedures as G1 but without laser irradiation; and G3, irrigation with saline solution (control). Dentin samples of each third were collected with carbide burs and aliquots were sowed to count viable cells. Results. The disinfection degree achieved was 100% in G1 and 98.39% in G2, when compared to the control group (G3). Conclusion. Diode laser irradiation provided increased disinfection of the deep radicular dentin in the parameters and samples tested.

Optimal subdivision of land in agrarian reform projects: an analysis using genetic algorithms

J.A. Ferreira Neto, E.C. Santos Junior, U. Fra Paleo, D. Miranda Barros, and M.C.O. Moreira. 2011. Optimal subdivision of land in agrarian reform projects: an analysis using genetic algorithms. Cien. Inv. Agr. 38(2): 169-178. The objective of this manuscript is to develop a new procedure to achieve optimal land subdivision using genetic algorithms (GA). The genetic algorithm was tested in the rural settlement of Veredas, located in Minas Gerais, Brazil. This implementation was based on the land aptitude and its productivity index. The sequence of tests in the study was carried out in two areas with eight different agricultural aptitude classes, including one area of 391.88 ha subdivided into 12 lots and another of 404.1763 ha subdivided into 14 lots. The effectiveness of the method was measured using the shunting line standard value of a parceled area lot`s productivity index. To evaluate each parameter, a sequence of 15 calculations was performed to record the best individual fitness average (MMI) found for each parameter variation. The best parameter combination found in testing and used to generate the new parceling with the GA was the following: 320 as the generation number, a population of 40 individuals, 0.8 mutation tax, and a 0.3 renewal tax. The solution generated rather homogeneous lots in terms of productive capacity.

The world of the Sumerian mother goddess : an interpretation of her myths

The present study is an interpretation of the two myths copied in the Old Babylonian period in which the Sumerian mother goddess is one of the main actors. The first myth is commonly called “Enki and Ninḫursaĝa”, and the second “Enki and Ninmaḫ”. The theoretical point of departure is that myths have society as their referents, i.e. they are “talking about” society, and that this is done in an ideological way. This study aims at investigating on the one hand which contexts in the Mesopotamian society each section of the myths refers to, and on the other hand which ideological aspects that the myths express in terms of power relations. The myths are contextualized in relation to their historical and social setting. If the myth for example deals with working men, male work in the area during the relevant period is discussed. The same method of contextualization is used regarding marriage, geographical points of reference and so on. Also constellations of mythical ideas are contextualized, through comparison with similar constellations in other Mesopotamian myths. Besides the method of contextualization, the power relations in the myths are investigated. According to this latter method, the categories at issue, their ranking, as well as their changed ranking, are noted. The topics of the myths are issues important for the kingship and the country, such as irrigation, trade, health and healing, birth, collective work, artisanry and rivalry. All these aspects are used in order to express what the power relations between the goddess Ninḫursaĝa/Ninmaḫ and the god Enki look like. The relations are negotiated and recalibrated, which leads to the goddess getting a lowered status. Part of the negotiations and recalibrations is gender behavior, which is related to historical developments in society. The present work points to the function of these myths as tools of recalibrating not only deities, but also men and women in society.

Ethics in a capitalistic society

The problem of semantics is inherent in any discussion of ethics. The general term "ethics" is itself commonly confused. In addition, systems of ethics must be built upon assumptions, and assumptions are necessarily subject to lengthy debate. These two problems are encountered in my investigation of the ethical practices of the modern business community and to remedy the situation I have taken two steps: the first being an attempt to clarify the meaning of terms used therein;-and the second being a clear description of the assumptions utilized to further my analysis. To satisfy those who would disagree with these assumptions, I have attempted to outline the consequences of differing premises. The first assumption in my discussion is that the capitalistic economy is powered by the motivation supplied by man's self-interest. We are conditioned to basing our courses of action upon an orientation toward gratifying this self-interest. Careers are chosen by blending aptitude, interest, and remuneration. of course, some people are less materially inclined than others, but the average member of our capitalistic society is concerned with the physical rewards derived from his employment. Status and happiness are all-important considerations in pursuing a chosen course of action, yet all too often they are measured in physical terms. The normal self-interest natural to mankind is heightened in capitalism, due to the emphasis placed upon material compensation. Our thinking becomes mechanistic as life devolves into a complex game played by the rules. We are accustomed to performing meaningless or unpleasant duties to fulfill our gratifications. Thought, consequently, interferes with the completion of our everyday routines. We learn quickly not to be outspoken, as the outspoken one threatens the security of his fellow man. The majority of the people are quite willing to accept others views on morality, and indeed this is the sensible thing to do as one does not risk his own neck. The unfortunate consequence of this situation has been the substitution of the legal and jural for the moral and ethical. Our actions are guided by legal considerations and nowhere has this been more evident than in the business community. The large legal departments of modern corporations devote full time to inspecting the legality of corporate actions. The business community has become preoccupied with the law, yet this is necessarily so. Complex, modern, capitalistic society demands an elaborate framework of rules and regulations. Without this framework it would be impossible to have an orderly economy, to say nothing of protecting the best interests of the people. However, the inherent complexities, contradictions, and sometimes unfair aspects of our legal system can tempt men to take things into their own hands. From time to time cases arise where men have broken laws while acting in good faith, and other cases where men have been extremely unethical without being illegal. Examples such as these foster the growth of cynicism, and generally create an antagonistic attitude toward the law on the part of business. My second assumption is that the public, on the whole, has adopted an apathetic attitude toward business morality. when faced with an ethical problem, far too many people choose to cynically assume that, if I don't do it someone else will. "The danger of such an assumption lies in that it eliminates many of the inhibitions that normally would preclude unethical action. The preventative factor in contemplating an unethical act not only lies in it going against the "right course of action", but also in that it would display the actor as one of the few, immoral practitioners. However, if the contemplator feels that many other people follow the same course of action, he would not feel himself to be so conspicuous. These two assumptions underly my entire discussion of modern business ethics., and in my judgment are the two most important causal factors in unethical acts perpetrated by the business community. The future elimination of these factors seems improbable, if not futile, yet there is no reason to consider things worse than they ever have been before. The heightened public interest in business morality undoubtedly lies in part in the fact that examples of corporate malpractice are of such magnitude in scope, and hence more newsworthy.