the same as it was when we first started. ” today ’ s injection program, however, faces a new set of problems. as federal regulators toughened rules for injecting hazardous waste, oil and gas companies argued that the new standards could drive them out of business. state oil and gas regulators pushed back against the regulations, too, saying that enforcing the rules for class 2 wells – which handle the vast majority of injected waste by volume — would be expensive and difficult. ultimately, the energy industry won a critical change in the federal government ’ s legal definition of waste : since 1988, all material resulting from the oil and gas drilling process is considered non - hazardous, regardless of its content or toxicity. “ it took a lot of talking to sell the epa on that and there are still a lot of people that don ’ t like it, ” said bill bryson, a geologist and former head of the kansas corporation commission ’ s conservation division, who lobbied for and helped draft the federal rules. “ but it seemed the best way to protect the environment and to stop everybody from just having to test everything all the time. ” the new approach removed many of the constraints on the oil and gas industry. they were no longer required to conduct seismic tests ( a stricture that remained in place for class 1 wells ). operators were allowed to test their wells less frequently for mechanical integrity and the area they had to check for abandoned wells was kept to a minimum – one reason drilling waste kept bubbling to the surface near chico. soon after the first chico incident, texas expanded the area regulators were required to check for abandoned waste wells ( a rule that applied only to certain parts of the state ). doubling the radius they reviewed in chico to a half mile, they found 13 other injection or oil and gas wells. when they studied the land within a mile – the radius required for review of many class 1 wells – officials discovered another 35 wells, many dating to the 1950s. the railroad commission concluded that the chico injection well had overflowed : the target rock zone could no longer handle the volume being pushed into it. trying to cram in more waste at the same speed could cause further leaks, regulators feared. the commission set new limits on how fast the waste could be injected, but did not forbid further disposal. the well remains in use to this day. in late 2008, samples of chico ’ s municipal drinking water were found to contain radium, a radioactive derivative of uranium and a common attribute of drilling waste. the water well was a few miles away from the


well remains in use to this day. in late 2008, samples of chico ’ s municipal drinking water were found to contain radium, a radioactive derivative of uranium and a common attribute of drilling waste. the water well was a few miles away from the leaking injection well site, but environmental officials said the contaminants discovered in the water well were unrelated, mostly because they didn ’ t include the level of sodium typical of brine. since then, ed cowley, the public works director, said commission officials have continued to assure him that brine won ’ t reach chico ’ s drinking water. but since the agency keeps allowing more injection and doesn ’ t track the cumulative volume of waste going into wells in the area, he ’ s skeptical that they can keep their promise. “ i was kind of like, ‘ you all need to get together and look at the total amount you are trying to fit through the eye of the needle, ’ ” he said. when sewage flowed from 20 class 1 wells near miami into the upper floridan aquifer, it challenged some of scientists ’ fundamental assumptions about the injection system. the wells – which had helped fuel the growth of south florida by eliminating the need for expensive water treatment plants — had passed rigorous epa and state evaluation throughout the 1980s and 1990s. inspections showed they were structurally sound. as class 1 wells, they were subject to some of the most frequent tests and closest scrutiny. yet they failed. the wells ’ designers would have calculated what is typically called the “ zone of influence ” — the space that waste injected into the wells was expected to fill. this was based on estimates of how much fluid would be injected and under what pressure. in drawings, the zone of influence typically looks like a hershey ’ s kiss, an evenly dispersed plume spreading in a predictable circular fashion away from the bottom of the well. above the zone, most drawings depict uniform formations of rock not unlike a layer cake. based on modeling and analysis by some of the most sophisticated engineering consultants in the country, florida officials, with the epa ’ s assent, concluded that waste injected into the miami - area wells would be forever trapped far below the south florida peninsula. “ all of the modeling indicated that the injectate would be confined in the injection zone, ” an epa spokesperson wrote to propublica in a statement. but as miami poured nearly half a billion gallons of partly treated sewage into the ground each day from the late 1980s through the mid 1990s, hydrogeologists learned that the earth – and the flow of fluids through


wrote to propublica in a statement. but as miami poured nearly half a billion gallons of partly treated sewage into the ground each day from the late 1980s through the mid 1990s, hydrogeologists learned that the earth – and the flow of fluids through it – wasn ’ t as uniform as the models depicted. florida ’ s injection wells, for example, had been drilled into rock that was far more porous and fractured than scientists previously understood. “ geology is never what you think it is, ” said ronald reese, a geologist with the united states geological survey in florida who has studied the well failures there. “ there are always surprises. ” other gaps have emerged between theories of how underground injection should work and how it actually does. rock layers aren ’ t always neatly stacked as they appear in engineers ’ sketches. they often fold and twist over on themselves. waste injected into such formations is more likely to spread in lopsided, unpredictable ways than in a uniform cone. it is also likely to channel through spaces in the rock as pressure forces it along the weakest lines. petroleum engineers in texas have found that when they pump fluid into one end of an oil reservoir to push oil out the other, the injected fluid sometimes flows around the reservoir, completely missing the targeted zone. “ people are still surprised at the route that the injectate is taking or the bypassing that can happen, ” said jean - philippe nicot, a research scientist at the university of texas ’ bureau of economic geology. conventional wisdom says fluids injected underground should spread at a rate of several inches or less each year, and go only as far as they are pushed by the pressure inside the well. in some instances, however, fluids have travelled faster and farther than researchers thought possible. in a 2000 case that wasn ’ t caused by injection but brought important lessons about how fluids could move underground, hydrogeologists concluded that bacteria - polluted water migrated horizontally underground for several thousand feet in just 26 hours, contaminating a drinking water well in walkerton, ontario, and sickening thousands of residents. the fluids travelled 80 times as fast as the standard software model predicted was possible. according to the model, vertical movement of underground fluids shouldn ’ t be possible at all, or should happen over what scientists call “ geologic time ” : thousands of years or longer. yet a 2011 study in wisconsin found that human viruses had managed to infiltrate deep aquifers, probably moving downward through layers believed to be a permanent seal. according to a study published in april in the journal ground water


: thousands of years or longer. yet a 2011 study in wisconsin found that human viruses had managed to infiltrate deep aquifers, probably moving downward through layers believed to be a permanent seal. according to a study published in april in the journal ground water, it ’ s not a matter of if fluid will move through rock layers, but when. tom myers, a hydrologist, drew on research showing that natural faults and fractures are more prevalent than commonly understood to create a model that predicts how chemicals might move in the marcellus shale, a dense layer of rock that has been called impermeable. the marcellus shale, which stretches from new york to tennessee, is the focus of intense debate because of concerns that chemicals injected in drilling for natural gas will pollute water. myers ’ new model said that chemicals could leak through natural cracks into aquifers tapped for drinking water in about 100 years, far more quickly than had been thought. in areas where there is hydraulic fracturing or drilling, myers ’ model shows, man - made faults and natural ones could intersect and chemicals could migrate to the surface in as little as “ a few years, or less. ” “ it ’ s out of sight, out of mind now. but 50 years from now? ” myers said, referring to injected waste and the rock layers trusted to entrap it. “ simply put, they are not impermeable. ” myers ’ work is among the few studies done over the past few decades to compare theories of hydrogeology to what actually happens. but even his research is based on models. “ a lot of the concepts and a lot of the regulations that govern this whole practice of subsurface injection is kind of dated at this point, ” said one senior epa hydrologist who was not authorized to speak to propublica, and declined to be quoted by name. “ it ’ s a problem, ” he said. “ there needs to be a hard look at this in a new way. ” abrahm lustgarten is a new york writer and photographer who reports on the environment, health and sports. more abrahm lustgarten. more related stories - if alex pareene was a cable news executive... - portland ' s senseless war on fluoride - graphic video reportedly shows possible london machete attack suspect - what economists get wrong about the jobs crisis - ted cruz : " i don ' t trust the republicans " - pa. governor " can ' t find " any latinos to work in


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versao impressa issn 0042 - 9686 bull world health organ vol. 79 no. 7 genebra jul. 2001 every death counts : measurement of maternal mortality via a census abstract : methods for measuring maternal mortality at national and subnational levels in the developing world lag far behind the demand for estimates. we evaluated use of the national population census as a means of measuring maternal mortality by assessing data from five countries ( benin, islamic republic of iran, lao people ' s democratic republic, madagascar, and zimbabwe ) which identified maternal deaths in their censuses. standard demographic methods were used to evaluate the completeness of reporting of adult female deaths and births in the year prior to the census. the results from these exercises were used to adjust the data. in four countries, the numbers of adult female deaths needed to be increased and three countries required upward adjustment of the numbers of recent births. the number of maternal deaths was increased by the same factor as that used for adult female deaths on the assumption that the proportion of adult female deaths due to maternal causes was correct. age patterns of the various maternal mortality indicators were plausible and consistent with external sources of data for other populations. our data suggest that under favourable conditions a national census is a feasible and promising approach for the measurement of maternal mortality. moreover, use of the census circumvents several of the weaknesses of methods currently in use. however, it should also be noted that careful evaluation of the data and adjustment, if necessary, are essential. the public health community is urged to encourage governments to learn from the experience of these five countries and to place maternal mortality estimation in the hands of statistical agencies. keywords maternal mortality ; censuses ; data collection / methods ; evaluation studies ; developing countries ( source : mesh ). mots cles mortalite maternelle ; recensement ; collecte donnees / methodes ; etude evaluation ; pays en development ( source : inserm ). palabras clave mortalidad materna ; censos ; recoleccion de datos / metodos ; estudios de evaluacion ; paises en desarrollo ( fuente : bireme ). high levels of maternal mortality in the developing world have been increasingly recognized as an urgent public health concern during the past decade. the 1987 safe motherhood conference in nairobi, kenya, drew attention to the fact that maternal mortality ratios in the developing world are at least 100 times greater than those found in industrialized countries, identifying maternal mortality as the health indicator with


the past decade. the 1987 safe motherhood conference in nairobi, kenya, drew attention to the fact that maternal mortality ratios in the developing world are at least 100 times greater than those found in industrialized countries, identifying maternal mortality as the health indicator with the greatest disparity between rich and poor countries. subsequently, several international forums including the 1990 world summit for children, the 1994 international conference on population and development ( icpd ), and the 1996 international conference on women in beijing, china, included a 50 % reduction in maternal mortality over the following decade among its stated goals. this emphasis was reaffirmed by the programme of action approved by the 1999 icpd + 5 in the hague, netherlands ( 1 ). this heightened attention to maternal health has greatly increased demand for measures of maternal mortality at the national and subnational level. such data serve well as broad indicators of progress but cannot be linked to specific interventions. however, the public health community has been slow to accept the fact that maternal mortality data cannot be used to evaluate the impact of the safe motherhood programme ( 2, 3 ). using such data to assess specific interventions can be dangerous. in matlab, bangladesh, for example, where there has been a recently reported decline in maternal mortality, efforts to link the decline to specific interventions failed when it was shown that similar decreases in maternal mortality occurred in both intervention and control areas ( 4 ). regardless of the intended use of the data, methods for measuring and monitoring maternal mortality lag far behind the demand for such statistics. in the industrialized world, civil registration systems generate the needed data on maternal mortality, albeit with substantial, and often acknowledged, underreporting ( 57 ). in the majority of developing countries, however, civil registration data are simply too incomplete to be useful, leading a growing number of countries to turn to sample surveys as a means of measuring maternal mortality. disadvantages of surveys for determining maternal mortality survey methods which attempt to identify recent maternal deaths in households require prohibitively large sample sizes because maternal deaths are relatively rare events. demographic surveillance systems, though valuable for research purposes, cannot safely be generalized to a national population. direct estimation techniques based on survey questions concerning the survival of each respondents sisters are able to increase the sample size at relatively low cost ( 8, 9 ). even using this methodology, however, sample sizes of 500015 000 female respondents, such as is common in the demographic and health surveys ( dhs ) programme, still generate highly imprecise direct estimates of maternal mortality with confidence limits of plus or


. even using this methodology, however, sample sizes of 500015 000 female respondents, such as is common in the demographic and health surveys ( dhs ) programme, still generate highly imprecise direct estimates of maternal mortality with confidence limits of plus or minus 30 %, even for reference periods that include events occurring over 7 or more years ( 10 ). indirect sisterhood estimates have similarly wide confidence intervals. given this imprecision, survey - based methods can only provide a national - level estimate, cannot provide information on differentials in maternal mortality, and can only give an estimate for a period that often covers 7 or more years. the degree of imprecision can be seen from the maternal mortality ratios and 95 % confidence intervals ( ci ) from recent surveys : central african republic 1451 ( 95 % ci : 11941709 ) ; indonesia 454 ( 95 % ci : 378529 ) ; and peru 218 ( 95 % ci : 148288 ) ( 10 ). given the shortcomings of the more commonly used approaches summarized above for the measurement of maternal mortality, the attributes of an ideal methodology are outlined in box 1. advantages of census - based measurement of maternal mortality looking at the attributes in box 1, ideally census measurement of maternal mortality would meet all the criteria. a high - quality, decennial census that includes questions on deaths in the household in the last one to two years, followed by questions which would permit identification of maternal deaths would produce current national and subnational maternal mortality statistics, as well as various differentials. this type of census could produce all four of the commonly used maternal mortality indicators, and would allow for trend analysis if undertaken more than once. the issue of sampling or other random error would be eliminated or greatly reduced as a census is not sample based. it would be possible in order to reduce cost to restrict the maternal mortality questions to a sufficiently large subsample of the census. also, data collection would be undertaken by an institution removed from health service provision. finally, periodicity would be adequate since most developing countries undertake a census every 10 years or so. the discussion of maternal mortality above implies measurement of a particular subset of all causes of deaths of adult females, i. e. deaths due to maternal causes. the existing literature on direct estimation of overall adult mortality via a census in the developing world suggests that questions about recent deaths in the household in a census have rarely provided useful information ( 14 ). for example, in the majority of african censuses, 4050 % of deaths may have been omitted


adult mortality via a census in the developing world suggests that questions about recent deaths in the household in a census have rarely provided useful information ( 14 ). for example, in the majority of african censuses, 4050 % of deaths may have been omitted. one reason for omission may be the break - up of the household after the death of a mother. given this background, it seems timely to evaluate the experience of countries which have used a census for the measurement of maternal mortality and, on that basis, develop appropriate recommendations. this approach is endorsed by the 1999 icpd + 5 programme of action, which specifically calls on the united nations and donors to support developing countries in undertaking censuses and surveys and to develop innovative and cost - effective solutions for improving estimates of maternal mortality ( 1 ). determining the maternal mortality ratio the most widely used indicator of maternal mortality, the maternal mortality ratio, relates the number of maternal deaths in a particular time period to the number of births in the same period. in order to calculate this indicator from a census, data have to be collected on deaths by age and sex ( to identify deaths of women of reproductive age ), on whether the death of a woman of reproductive age was due to maternal causes, and on births. evaluation of a census as a means of estimating maternal mortality ratios thus requires evaluation of the completeness of recording of adult female deaths, of the adequacy of the approach used to identify maternal deaths, and of the completeness of data on births. five countries were identified which collected maternal mortality data in their most recent censuses ( benin, islamic republic of iran, lao peoples democratic republic, madagascar, and zimbabwe ). the characteristics of these censuses varied considerably, as shown in table 1. the number of enumerators trained to conduct the census ranged from 4800 in benin to over 22 000 in zimbabwe. the length of the census instrument also varied from 26 questions in lao peoples democratic republic to 52 questions in benin. the duration of enumerator training, traditionally very brief, ranged from 1 week or less in madagascar, zimbabwe, and lao peoples democratic republic, to 24 weeks in benin and the islamic republic of iran. in the islamic republic of iran, the census was conducted with all respondents in farsi. in the other countries the census instrument was written in the administrative language of the country and translated as required in the field for respondents speaking other languages. data collection and question formulation the data collection methods and question formulation varied between countries. all five countries collected adult mortality data by


countries the census instrument was written in the administrative language of the country and translated as required in the field for respondents speaking other languages. data collection and question formulation the data collection methods and question formulation varied between countries. all five countries collected adult mortality data by asking the age and sex for all deaths in the household in the year before the interview. however, the methods used to identify maternal deaths varied substantially ( table 2 ). in benin, lao peoples democratic republic, and zimbabwe, a time - of - death approach was used : one or more questions were asked to determine if adult female deaths occurred during pregnancy, childbirth, or the postpartum period. in madagascar, the following question was asked : were there any live births in this household during the last 12 months whose mother died ( in the last 12 months )? the islamic republic of iran used a follow - up interview within 2 months of the census in households reporting the death of a woman of reproductive age. at these follow - up interviews, the interviewers, who had been trained to carry out verbal autopsies, asked a series of questions concerning the symptoms surrounding the death, and for deaths that were reported as occurring in health facilities, examined the available medical records. completeness of reporting for each country, standard evaluation methods were used to assess the completeness of reporting of all female deaths and births. the completeness of reporting of adult female deaths was assessed using the general growth balance technique that compares reported deaths to mortality information encapsulated in the census age distribution ( 15, 16 ). the method makes use of the fact that for any population ( or segment of a population, such as people of a given age or older ) the entry rate into the segment minus the growth rate of the segment must be equal to the exit rate from the segment. systematic differences between the entry rate and the growth rate ( a residual estimate of the exit rate calculated from the census age distributions ) on the one hand and the exit rate ( calculated from information about deaths by age ) on the other imply an inconsistency between the reporting of population and the reporting of deaths. the magnitude of the inconsistency can be interpreted as a measure of completeness of death reporting relative to population reporting and can then be used to adjust the mortality estimates calculated from the original data. although several variations of the original method exist, all are based on the assumption that misreporting of deaths is constant across age group. net migration is generally assumed to be negligible ( 15, 16 ). evaluation of birth


original data. although several variations of the original method exist, all are based on the assumption that misreporting of deaths is constant across age group. net migration is generally assumed to be negligible ( 15, 16 ). evaluation of birth data. the evaluation of the birth data was carried out using two different techniques. firstly, reverse projection was used to estimate the number of births from the number of young children in the population, after allowing for risks of childhood death. for example, the number of children aged 04 years in the population can be divided by the probability of surviving from birth to the age group 04 years ( a standard life - table function ) to estimate the number of births in the 5 years before the census. this technique requires both the age distribution of the population and some basis for estimating mortality risks under the age of 5 years. for the application described here, child mortality was estimated from information available from the census on the numbers of children ever born and children surviving, by age of the mother ( 16 ). the second technique, generally called the p / f ratio method, which compares average parity to cumulated current fertility, involves comparing data on births in the year before the census by age of the mother with data on the average numbers of children ever born by women in each age group ( 16 ). this technique relies on the equivalence of lifetime fertility and cumulated age - specific fertility rates. for example, cumulated age - specific fertility rates for women aged 1524 years would be equal to the lifetime fertility of women aged exactly 25 years. appropriately cumulated age - specific fertility rates calculated from births in the 12 months preceding the census can be compared with average numbers of children ever born for women classified by 5 - year age groups ; these rates should be equal if data are accurate and fertility is not changing ( 16 ). if the cumulated age - specific fertility rates are systematically lower than the average numbers of children ever born, births in the 12 months preceding the census are probably underreported. application of this method requires care in situations of changing fertility, where cumulated current fertility will not be equal to lifetime fertility, but conclusions can still be drawn from the results. evaluation of maternal death identification. there are no demographic methods for the evaluation of the identification of maternal deaths. our evaluation therefore relied on an assessment of the plausibility of age patterns of maternal mortality and a comparison of the census results to external sources of data, where available, or to empirical regularities such as an expected j - shape in the


deaths. our evaluation therefore relied on an assessment of the plausibility of age patterns of maternal mortality and a comparison of the census results to external sources of data, where available, or to empirical regularities such as an expected j - shape in the maternal mortality ratio by age, or an inverted j - shape for the proportion of all deaths of women of reproductive age that were due to maternal causes. estimates of the maternal mortality ratio given the historical record of estimates of mortality and fertility based on events reported in the year prior to the census in developing countries, it was expected that data for most if not all countries would require substantial upward adjustment : this expectation was confirmed. table 3 presents the results of this analysis for adult female deaths, births, and the resulting maternal mortality ratios. although the adjustment factors were often large, the evaluation techniques were deemed, on the basis of their internal patterns, to have worked well enough to give reasonably precise estimates, though it should be noted that no standard significance tests can be applied to these results. the evaluation techniques described above generated two to three possible adjustment factors for the data on adult female deaths and births. the different factors were calculated by using different methods, or by variations in the assumptions underlying a particular method, or by differing age groups selected for analysis. preferred adjustments ( shown in table 3 ) represent the group consensus after reviewing the results, bearing in mind the demographic conditions of each country. thus, for example, the comparison of cumulated current fertility with lifetime fertility ( p / f ratio method ) was given little weight for the islamic republic of iran and zimbabwe, since fertility is known to have fallen rapidly in both countries. comparison of adult female deaths to the age distribution of the population, which assumes an unchanging population age distribution, was also given low weight in both the islamic republic of iran and zimbabwe, where growth rates have been changing quickly, thus violating an assumption of the method. for the three other countries, adjustment factors tended to be similar regardless of the methodologies used. with the exception of zimbabwe, where reporting was estimated to be complete, the numbers of adult female deaths reported in these censuses required upward adjustment by factors ranging from 1. 6 to 3. 0. data on births in the last year required adjustment in three of the five countries, with adjustment factors ranging from 1. 30 to 1. 65 ; reporting of births in madagascar and zimbabwe was deemed to be complete. regarding maternal deaths, the expected j - shaped age pattern of the maternal mortality ratio was evident in four of the five countries. likewise


factors ranging from 1. 30 to 1. 65 ; reporting of births in madagascar and zimbabwe was deemed to be complete. regarding maternal deaths, the expected j - shaped age pattern of the maternal mortality ratio was evident in four of the five countries. likewise, the proportion of adult female deaths due to maternal causes was as expected and was consistent with data on age at first childbirth ( data not shown ). it was not possible to analyse the maternal death data from madagascar : problems with question formulation meant that there were no data on age at death of the mother. comparisons with survey data recent estimates of maternal mortality were available in benin and zimbabwe from national surveys ( dhs ) for comparative purposes. the dhs estimate of 498 in benin refers to the period 198996 ( 17 ). although higher than the adjusted census estimate of 338, the census estimate falls near the confidence interval surrounding the survey - based estimate. in zimbabwe, the census and dhs estimates are virtually identical ( 395 and 393, respectively ). however, the dhs estimate was based on only 55 maternal deaths reported over the 7 - year period from 198894 compared to 1419 maternal deaths reported to the census over the 12 months preceding interview in august 1992 ( 10 ). the findings from this evaluation exercise suggest that a census is a feasible and promising approach for maternal mortality measurement under certain favourable conditions. given the competition for additional questions in a population census, directors of census offices from the five countries in this analysis all agreed that the most important condition to be met before considering the addition of maternal mortality questions is a commitment on the part of the ministry of health to use the data for programming and policy - level decision - making. for example, high values for certain regions or population subgroups could help in targeting interventions. the second essential condition is a commitment to evaluate census results following data collection. all stages of data collection and evaluation need to be carried out with appropriate technical input. as is obvious from the results presented here, evaluation of the data using standard demographic procedures often leads to substantial upward adjustment of results. based on the experience in these five countries, recommendations were compiled for governments considering maternal mortality measurement in the future ( see box 2 ). it was not possible to estimate the cost implications of adding questions to the censuses of the five countries studied. however, while it is expected that each additional question affects to some extent the average duration of the interview and data processing, many developing countries already inquire into all births and deaths within the household, as is recommended by the united


five countries studied. however, while it is expected that each additional question affects to some extent the average duration of the interview and data processing, many developing countries already inquire into all births and deaths within the household, as is recommended by the united nations ( 18 ). if this is the case, measuring maternal mortality requires only one to three additional questions, depending on the format selected to identify maternal deaths. furthermore, the question or questions will only be asked where a recent adult female death has taken place, which is expected to occur in less than 1 % of households. when considering the differential costs associated with a survey versus a census, one should also remember that a census provides data on regional differences, as well as on other variables of interest, as opposed to one national estimate that would be available from a survey. choosing a census to determine maternal mortality clearly, all pragmatic data collection methods in both the industrialized and developing world generate estimates of maternal mortality that are only approximate. the census is no exception. nonetheless, given the expense, imprecision, and the fact that adjustment techniques do not exist for the traditional methods in use, the census has several advantages which make it worth advocating. in all of the five countries except madagascar, the initial motivation for the pioneering efforts made by the census bureaus originated from a request from a ministry of health, a womens union, or from an international health agency. the results of our evaluation should serve as a call to health ministries and census bureaus in developing countries to learn from the experience of these five countries and follow the recommendations listed above. further implementation of the approach and attention to these recommendations may also lead to improvements in the future. by doing so, the public health community, armed with essential information on differentials in maternal mortality, is free to concentrate its efforts on interventions to reduce maternal deaths, while measurement is left to statistical agencies familiar with the complexities of the task. this study was made possible by support from the united states agency for international development under the terms of cooperative agreement hrn - a - 00 - 97 - 00018 - 00. the opinions expressed are those of the authors and do not necessarily reflect the views of the united states agency of international development. conflicts of interest : none declared. chaque deces compte : mesure de la mortalite maternelle a partir des recensements les methodes de mesure de la mortalite maternelle au niveau national et subnational dans les pays en developpement sont tres insuf


: mesure de la mortalite maternelle a partir des recensements les methodes de mesure de la mortalite maternelle au niveau national et subnational dans les pays en developpement sont tres insuffisantes en regard de la demande destimations. nous avons evalue lutilisation des recensements nationaux de population comme moyen de mesurer la mortalite maternelle, en analysant les donnees de cinq pays ( benin, madagascar, republique democratique populaire lao, republique islamique diran et zimbabwe ) dans lesquels les deces maternels sont identifies dans les recensements. des methodes demographiques classiques ont ete utilisees pour evaluer lexhaustivite de la notification des deces de femmes adultes et des naissances au cours de lannee precedant le recensement. les resultats de ces etudes ont ete utilises pour ajuster les donnees. il a fallu revoir a la hausse le nombre de deces de femmes adultes dans quatre pays et le nombre de naissances recentes dans trois pays. le nombre de deces maternels a ete augmente du meme facteur que celui de deces de femmes adultes en partant de lhypothese que la proportion de deces de femmes adultes lies a la maternite etait correcte. la repartition par age des divers indicateurs de mortalite maternelle etait plausible et compatible avec les sources exterieures de donnees pour dautres populations. nos donnees indiquent que, dans des circonstances favorables, lutilisation du recensement national constitue une approche realisable et interessante pour la mesure de la mortalite maternelle, et quelle evite en outre certaines faiblesses des methodes actuellement en usage. il faut cependant noter quil est indispensable devaluer soigneusement les donnees et si necessaire de les ajuster. les acteurs de sante publique sont instamment invites a encourager les go


causas maternas era correcta. los perfiles por edades de los diversos indicadores de la mortalidad materna fueron plausibles y coherentes con las fuentes externas de datos para otras poblaciones. nuestros datos parecen indicar que, en condiciones favorables, el uso de un censo nacional es un metodo factible y prometedor para medir la mortalidad materna. ademas, el uso del censo permite soslayar varias de las deficiencias de los metodos actualmente empleados. no obstante, debe senalarse tambien que para ello es esencial evaluar detenidamente los datos, y ajustarlos si es necesario. hay que apremiar a la comunidad de salud publica para que aliente a los gobiernos a aprender de la experiencia de esos cinco paises y a encomendar las estimaciones de la mortalidad materna a los organismos de estadistica oportunos. 1. proposals for key actions for the further implementation of the programme of action of the international conference on population and development ; report of the secretary general. united nations economic and social council, 1999 ( e / cn. 9 / 1999 / pc / 4 ). [ links ] 2. graham w, filippi v, ronsmans c. demonstrating programme impact on maternal mortality. health policy and planning, 1996, 11 ( 1 ) : 1620. [ links ] 3. the safe motherhood action agenda, priorities for the next decade. report on the safe motherhood technical consultation 1823 october 1997, colombo, sri lanka. new york, family care international, 1998. [ links ] 4. ronsmans c et al. decline in maternal mortality in matlab, bangladesh, a cautionary tale. lancet, 1997, 350 : 18101814. [ links ] 5. atrash h, alexander s, berg c. maternal mortality in developing countries : not just a concern of the past. obstetrics and gynecology, 1995, 86 ( 4, part 2 ) : 700705. [ links ] 6. bouvier - colle mh et al. reasons for the under - reporting of maternal mortality in france, as


##8. [ links ] 15. hill, k. estimating census and death registration completeness. asian and pacific census forum, 1987, 1 ( 3 ) : 813. [ links ] 16. manual x. indirect techniques for demographic estimation. populations studies no. 81. new york, united nations, department of economic and social affairs, 1983. [ links ] 17. kodjogbe n et al. enquete demographique et de la sante, republique du benin. [ demographic and health survey, republic of benin. ] calverton, md, macro international, 1996. [ links ] 18. principles and recommendations for population and housing censuses, revision 1. united nations, department of economic and social affairs ( series m, no. 67 / rev. 1 ), 1998. [ links ] 1 director, monitoring / evaluation and research, maternal and neonatal health project, jhpiego, 1615 thames street, suite 100, baltimore, md 21231, usa ( email : email @ example. com ). correspondence should be addressed to this author. 2 professor of population studies, department of social policy, london school of economics, london, england. 3 professor, johns hopkins school of hygiene and public health, baltimore, md, usa. 4 director of the census, institut national de la statistique et de l ' analyse economique, cotonou, benin. 5 demographer, central statistical office, harare, zimbabwe. 6 demographer, central bureau of statistcs, nairobi, kenya. 7 epidemiologist, ministry of health and medical education, tehran, islamic republic of iran. 8 demographer, centre national de recherches sur l ' environnement, antananarivo, madagascar. 9 director of the census, national statistical center, vientiane, lao peoples democratic republic. 10 senior lecturer, london school of hygiene and tropical medicine, london, england. ref. no. 99 - 0118


mar. 19, 1998 west lafayette, ind. - - purdue university researchers have developed a new class of materials that has a wide variety of potential applications, from a coating to repel liquids to a membrane that could be used in wastewater treatment and drug delivery. the materials are called co - polymer networks, which are " built " from intersecting chains of small molecules linked together to form a larger, mesh - like structure. the two molecular " building blocks, " or monomers, used in the new materials are acrylic acid and a derivative of oligoethylene glycol. the properties of an individual material in the class can be varied depending on the relative amounts of the monomers used to prepare it. " because these materials are co - polymers, we can control their properties more precisely and over a wider range than we could if they were made of a single type of monomer, " says robert scott, a ph. d. candidate at purdue who helped develop the material. " this level of versatility and control allows for a number of applications. " the new class of materials is unique in that it is the first time materials with such a wide variety of properties have been derived from a combination of these two monomers, says scott ' s adviser nicholas peppas, the showalter distinguished professor at purdue. peppas has conducted research in polymers for more than 26 years and has developed new materials and polymers for applications that include biomedical applications. " the most exciting thing about this research is that we ' ve not only developed a class of materials with diverse properties, but we ' ve also come to understand fundamentally, on a molecular level, the basis for those properties, " scott says. scott will present information on the new materials in two talks march 16 at the annual meeting of the american physical society in los angeles. his research has been funded by the national science foundation and the national institutes of health. the new materials, which were developed over the past four years with the help of lab assistant atsmon shahar, are particularly suited for separations applications, such as filtering mechanisms used in wastewater treatment, where only certain substances are allowed to pass through the mesh created by the interlacing polymers. " as we increase the acrylic acid content of the materials, the oligoethylene glycol chains that make up the network move further apart, increasing the mesh size, which in turn determines what substances can pass through, " scott explains. " by varying the acrylic acid content, as well as other


##igoethylene glycol chains that make up the network move further apart, increasing the mesh size, which in turn determines what substances can pass through, " scott explains. " by varying the acrylic acid content, as well as other parameters, we can precisely control the size of the molecules we allow through. " another application scott has investigated in his lab is the controlled release of substances. " we ' ve made systems that contain a model drug, and we ' re studying how the rate of diffusion of that drug out of this polymer varies as we vary the polymer structure, " scott says. " using the material as a membrane for drug delivery is a particularly appealing application because we have very fine control over what drugs could be released through it and under what conditions. " in addition, the acrylic acid in the materials makes them sensitive to the acidity, or ph, of their environment. the mesh size and diffusive properties vary depending on the ph of the environment - - an important consideration for drug delivery applications, since different parts of the body exhibit different ph levels. for example, a capsule incorporating this material and containing a particular drug might remain " closed " in the mouth and " open " in the stomach to release a drug. one type of the material also can be made to have a very dense network of molecular chains, which would make it very resistant to liquids, scott says. " in that case it might make an ideal coating for applications that require a very low permeability to moisture, " he says. " we can also modify the properties so that it will absorb various amounts of liquid. we ' re looking very closely at how we can control its affinity for water. " depending on its affinity for water, the material might also find applications in the cosmetics industry in moisturizers, peppas says. peppas says further studies of the materials will be needed before they are ready for industrial or medical use. other social bookmarking and sharing tools : the above story is reprinted from materials provided by purdue university. note : materials may be edited for content and length. for further information, please contact the source cited above. note : if no author is given, the source is cited instead.


feb. 7, 2002 west lafayette, ind. — a detailed look at a syringe - like structure designed to inject viral dna into a host cell reveals a unique and complex entry scheme for viruses. the study may provide clues to how similar viruses infect cells and suggest ways for developing a new class of antibiotics and other drugs to prevent illnesses caused by viral pathogens. scientists at purdue university have solved the three - dimensional structure of the bacteriophage t4 virus, a virus that resembles a lunar lander in both its looks and intricate workings. the study, published in the jan. 31 issue of the journal nature, reveals for the first time how the virus binds to the surface of the host, punctures the cell wall with a syringe - like tube and injects its own genetic blueprint into the cell. this genetic information then sets the cell ' s machinery to work creating replicas of the virus. " though the t4 virus has been studied extensively in the past, this study provides the first detailed information on the virus structure and how it works, " says michael rossmann, hanley distinguished professor of biological sciences at purdue who directed the study. bacteriophage t4 is a virus that infects only bacteria, in this case e. coli, a bacteria used extensively in molecular biology research. the study of bacterial viruses such as t4 is useful in understanding many basic functions in biology, rossmann says. " this particular study tells us a great deal about how a virus infects a cell, " he says. " these processes tend to be quite general, so mechanisms used by one virus often are similar to mechanisms used by other viruses, including those that infect humans. " bacteriophages may play a future role in controlling disease - causing bacteria, says kamal shukla, the national science foundation project officer for this research. " knowing the exact mechanism of t4 bacteriophage infectivity is a significant breakthrough, " shukla says. " this information could eventually help in creating designer viruses that could be the next class of antibiotics. " analysis of the cell - puncturing device also reveals a structure that may hold potential for applications in nanotechnology, such as microscopic probes, rossmann says. " this a very stable structure that looks like a small stylus, " he says. " it might be useful as a probe in an atomic force microscope, which employs a probe of molecular dimension. " the t4 virus consists of an


says. " this a very stable structure that looks like a small stylus, " he says. " it might be useful as a probe in an atomic force microscope, which employs a probe of molecular dimension. " the t4 virus consists of an elongated head, which carries the virus ' genetic material, and a tail made up of a hexagonal baseplate and six leg - type structures, called long - tail and short - tail fibers. in the study, the purdue group analyzed atom - by - atom the structure of the virus ' baseplate. the baseplate is the key component of the virus, rossmann says, serving as a " nerve center " and sending signals to and from the virus ' head and tail fibers. while transmitting its messages, the baseplate also prepares the virus machinery to eject its dna into the host cell. " a whole series of events are required to recognize, attach and confirm the attachment, and then contract so that the viral dna can be ejected into the host, " rossmann says. " it ' s a very complicated system for infecting a cell. " the viral machine works as follows : the virus uses its long - tail fibers to recognize its host and to send a signal back to the baseplate. once the signal is received, the short - tail fibers help anchor the baseplate into the cell surface receptors. as the virus sinks down onto the surface, the baseplate undergoes a change — shifting from a hexagon to a star - shaped structure. at this time, the whole tail structure shrinks and widens, bringing the internal pin - like tube in contact with the outer membrane of the e. coli cell. as the tail tube punctures the outer and inner membranes of the e. coli cell, the virus ' dna is injected through the tail tube into the host cell. the dna then instructs the bacterium to produce new viruses. so many are produced, in fact, that the e. coli eventually bursts, setting masses of new virus free to infect other cells. the new detailed images provided by rossmann ' s group also reveal a structure slightly different than what scientists had envisioned. " we found that the baseplate is shaped like a cup or small dome, " rossmann says. " previously it was believed that the baseplate was a rather flat structure. " the study also is the first to show how the syringe - like tube is situated in the center of the baseplate, positioned in line with the dna contained in the virus head.


believed that the baseplate was a rather flat structure. " the study also is the first to show how the syringe - like tube is situated in the center of the baseplate, positioned in line with the dna contained in the virus head. the studies were done at purdue using x - ray crystallography, a technique often used to study structures such as proteins and viruses, in atomic detail. but the process works only if the substances can be made to form crystals. crystals are used because the diffraction pattern from one single molecule could be insignificant, but the many individual, identical molecules in a crystal amplify the pattern. diffraction patterns are created when an x - ray beam hits a crystal, causing the electrons surrounding each atom to bend the beam. computers can then be used to interpret this pattern and reconstruct the positions of the atoms. " because the structure is so complex, we could not crystallize the entire virus structure at once, " rossmann says. " instead, we crystallized the various components and gradually pieced together a picture of the structure. " the research was funded by the national science foundation. rossmann and his research team at purdue collaborated with shuji kanamaru and fumio arisaka of the tokyo institute of technology, and vadim mesyanzhinov of the shemyakin - ovchnnikov institute of bioorganic chemistry in moscow, russia. other social bookmarking and sharing tools : note : materials may be edited for content and length. for further information, please contact the source cited above. note : if no author is given, the source is cited instead.


mar. 5, 2008 exposed skin cells weather conditions harsh enough to mutate dna. to keep these mutations from spreading, evolution has found a way to keep these cells from proliferating. rockefeller university and hhmi researchers have now discovered evolution ' s solution : a tiny strand of rna. but the research ' s implications go deeper, and may also suggest how healthy cells elsewhere in the body can turn cancerous. every minute, 30, 000 of our outermost skin cells die so that we can live. when they do, new cells migrate from the inner layer of the skin to the surface of it, where they form a tough protective barrier. in a series of elegant experiments in mice, researchers at rockefeller university have now discovered a tiny rna molecule that helps create this barrier. the results not only yield new insight into how skin first evolved, but also suggest how healthy cells can turn cancerous. hundreds of these tiny rna molecules, called micrornas, are expressed in skin, " but there was something curious about one in particular, microrna - 203, " says rui yi, a postdoc who works with elaine fuchs, head of the laboratory of mammalian cell biology and development. " as an embryo develops, the expression of microrna - 203 jumps very quickly over just two days. from being barely detectable at day 13, this microrna becomes the most abundant expressed in skin, " says yi, whose work will be published as an advance online publication in nature march 2. micrornas, which were discovered in mammals in 2001, regulate genes outside of the cell ' s nucleus. yi and fuchs, who is also a howard hughes medical institute investigator and rebecca c. lancefield professor at rockefeller, found that during the 13th day of development, mouse skin is primarily composed of undifferentiated stem cells. two days later, these stem cells exit the inner layer of the skin and begin to differentiate into cells that form the outermost, protective layer. microrna - 203 ' s expression skyrockets precisely during this period, suggesting that it plays some key role in the barrier ' s development. in order to figure out its role, yi and fuchs needed to pinpoint exactly where microrna - 203 is expressed. other micrornas have been found to be specific to heart and muscle tissues ; some exist almost exclusively in the brain. however, this microrna was found only in very specific types of skin - - stratified epithelial tissues, to be exact - - and only in this skin type


specific to heart and muscle tissues ; some exist almost exclusively in the brain. however, this microrna was found only in very specific types of skin - - stratified epithelial tissues, to be exact - - and only in this skin type ' s outer layers. what ' s more, this expression pattern is identical to that found in humans, zebrafish, chickens and the like - - in other words, vertebrates that evolved more than 400 million years apart. " if it has been expressed in this very specific tissue for a long time and across several species, it means that it probably plays an important role there, " says yi. to find out its function, yi, in one set of experiments, used a genetic technique to precociously express microrna in the inner layer of the skin, where stem cells proliferate at a fast clip. in a second set of experiments, he blocked microrna - 203 from functioning in the outer layer using an antagomir, a molecule that binds directly to microrna - 203 and shuts down its ability to carry out its function. in the first set, he found that the stem cells proliferated significantly less than they did when microrna - 203 wasn ' t expressed, and, as a result, the mice formed very thin skin - - hardly a protective layer at all. the stem cells, the researchers saw, lost their ability to proliferate not because microrna - 203 killed them off but because it suppressed the activity of a molecule called p63, whose job is to keep cells, primarily stem cells, proliferating. in the second set of experiments, yi found that the cells in the outer layer proliferated significantly more than they did when microrna - 203 was expressed. the reason : because microrna - 203 wasn ' t available to shut down p63 ' s busy work. " we found that microrna - 203 acts to stop the translation of the p63 protein, " says fuchs. " the result is a swift transition from proliferating stem cells within the innermost layer of the epidermis and terminally differentiating cells as they exit this layer and move outward to the skin surface. " the findings have intriguing implications for cancer, since p63 is found in excess in cancer cells. " as a next step, we are going to examine whether low expression of microrna - 203 is associated with squamous cell carcinomas, " says fuchs, " and whether by putting back microrna


mar. 26, 2008 a special type of magnetic resonance imaging ( mri ) can depict changes in blood volume in the brain that often precede cancerous transformation of brain tumors, according to a new study. " we found that increases in blood volume within the tumor measured noninvasively by perfusion mri precede other markers of malignant transformation by a year or more, " said study co - author adam waldman, ph. d., m. r. c. p., f. r. c. r., consultant neuroradiologist and imaging research director at imperial college nhs trust and honorary senior lecturer at imperial college and university college, london. low - grade gliomas are primary brain tumors that grow slowly over several years. eventually, almost all low - grade gliomas progress to high - grade gliomas, which carry a poor prognosis. " patients with low - grade gliomas are often young and may remain clinically well for many years but, at an unpredictable time their tumor will transform to an aggressively high - grade glioma, " dr. waldman said. for the study, the researchers performed perfusion mri on 13 patients with low - grade gliomas to determine whether relative cerebral blood volume ( rcbv ) changes are an indicator of future malignant transformation. brain tumors can bring about the formation of new blood vessels, a process known as angiogenesis. these vessels are abnormal and lead to changes in blood volume and flow. using perfusion mri, radiologists can detect these changes well before they become apparent on contrast - enhanced mr images. the patients underwent perfusion mri and contrast - enhanced mri every six months for up to three years. seven patients progressed to high - grade, malignant gliomas between six and 36 months. in the six patients whose disease remained stable, rcbv remained relatively stable, increasing from a mean level of 1. 31 at the beginning of the study to 1. 52 over the follow - up period. however, in the patients exhibiting tumor transformation, mean rcbv increased progressively from 1. 94 at study entry to 3. 14 twelve months prior to transformation, to 3. 65 six months prior to transformation and to 5. 36 at the time transformation was diagnosed. these findings suggest that significant changes in rcbv represent an important marker of malignant change in gliomas and reflect the earliest stages of the transformation process. further, the data support the likelihood that the cellular processes underlying malignant transformation may occur 12 months


findings suggest that significant changes in rcbv represent an important marker of malignant change in gliomas and reflect the earliest stages of the transformation process. further, the data support the likelihood that the cellular processes underlying malignant transformation may occur 12 months or more before visible on contrast mri. " we have shown that perfusion mri provides a noninvasive means of assessing the risk of transformation in individual patients, " dr. waldman said. " increasing perfusion can be regarded as an early warning sign of impending malignant transformation that can assist radiologists in identifying those patients most likely to benefit from earlier or more aggressive treatment. " journal reference : " low - grade gliomas : do changes in rcbv measurements at longitudinal perfusion - weighted mr imaging predict malignant transformation? " collaborating with dr. waldman were nasuda danchaivijitr, m. d., daniel j. tozer, ph. d., christopher e. benton, b. sc., gisele brasil caseiras, m. d., paul s. tofts, ph. d., jeremy h. rees, ph. d., f. r. c. p., and h. rolf jager, m. d., f. r. c. r. other social bookmarking and sharing tools : note : if no author is given, the source is cited instead.


nov. 24, 2008 a review of studies projecting the impact of climate change on air quality, including effects on morbidity and mortality, indicates that adverse health effects will likely rise with changes in pollutant creation, transport, dispersion, and deposition. however, reducing greenhouse gas emissions could go far in mitigating adverse effects. worldwide, 800, 000 deaths and 7. 9 million disability - adjusted life - years lost from respiratory problems, lung disease, and cancer were attributed to urban air pollution in 2000, according to the world health organization. ground - level ozone is a known pulmonary irritant that affects the respiratory mucous membranes, other lung tissues, and respiratory function. exposure to elevated concentrations of ozone is associated with increased hospital admissions for pneumonia, chronic obstructive pulmonary disease, asthma, allergic rhinitis, and other respiratory diseases, and with premature mortality. “ projections suggest that climate change will increase concentrations of tropospheric ozone, at least in high - income countries when precursor emissions are held constant, which would increase morbidity and mortality, ” wrote authors kristie l. ebi and glenn mcgregor. " the potential impacts of climate change on ozone concentrations have not been projected for low - income countries, many of which currently have significantly higher ozone exposures. " additional research is needed to better project the health impacts of changing concentrations of ozone due to climate change. sources of uncertainty include the projected degree of future climate change, the impact of future emissions and their pathways, potential changing weather patterns, the severity of episodes of poor air quality, and changes in population vulnerability. these findings appear in the november 2008 issue of the peer - reviewed journal, environmental health perspectives ( ehp ). other social bookmarking and sharing tools : note : if no author is given, the source is cited instead.


may 20, 2010 bbsrc - funded researchers at the university of oxford and royal holloway university of london have discovered that the commonly used and naturally occurring bacterial insecticide bt works best if applied to young plants and is enhanced by the presence of the insect pests. the research is published in the open - access journal plos pathogens. spraying bt - - the bacterium bacillus thuringiensis - - is a common method for controlling a variety of insect pests and is one of the main approaches to chemical - free pest control in agriculture. optimising sustainable farming techniques can help meet the challenge of feeding 9 billion people by 2050 using fewer resources and with minimum impact on the environment. senior researcher dr mike bonsall at the university of oxford said : " bt has been used commercially for about 40 years and is readily available to control pest moths and the like, but until now we ' ve known very little about the natural abundance of the bacteria in the environment and what happens when we apply extra bacteria as a means of pest control. it ' s really important to understand what is happening so that we can, for example, know what factors might have an impact on the insects becoming resistant to bt. " bt is found naturally in soils and on plants and exists as many different varieties that each have a preference for infecting different organisms. bt strains that are specific to certain insects rely on being able to infect those insects in order to reproduce. the researchers studied a strain called st8, which infects the diamondback moth - - a pest that attacks cabbages, broccoli and related crops - - and they found that the population of bacteria ( either existing or applied ) establishes itself more readily when the insects are present. the team set up several cabbage plots in the field to examine what was happening when there were extra insects and / or extra bacteria added to what was already present. then they took samples of soil and leaves. for each sample they looked at the genetics of the bacteria to build a profile of which strains of bt were present and in what numbers. lead researcher dr ben raymond at royal holloway university of london said : " we found that our strain, st8, is the most common in the environment already and it also seems to be best at getting onto the leaves where it can infect the moths. we think that the st8 that exists naturally in the farm environment might well be colonising the plant as growing seedlings so it gets the earliest possible opportunity to infect the moths, which of course it needs


where it can infect the moths. we think that the st8 that exists naturally in the farm environment might well be colonising the plant as growing seedlings so it gets the earliest possible opportunity to infect the moths, which of course it needs to do to survive. " this makes sense given that we also found that when there are extra insects in the environment the bacteria actually do much better and can be found in larger numbers. it also shows why spraying the plants, especially young ones, rather than the soil is the best way of using bt to control insect pests. " the research team are also looking at factors that affect the chances of insects becoming resistant to bt. in particular they are looking at the way the toxin that kills the insect and an antibiotic that bt produces to get rid of competing strains of bacteria in the insect ' s gut both impact the evolution of resistance in the insect. professor douglas kell, bbsrc chief executive said : " sustainable solutions to future food security will rely on a thorough understanding of how ecosystems operate. this is a good example where the interactions between different parts of such a system have a significant impact on how we can control pests using biological rather than chemical methods. it is also vital that our ongoing practices with bt present minimal risk of insects becoming resistant and so work to understand the fundamental biology that happens within this system is extremely important. " other social bookmarking and sharing tools : the above story is reprinted from materials provided by biotechnology and biological sciences research council. - ben raymond, kelly l. wyres, samuel k. sheppard, richard j. ellis, michael b. bonsall. environmental factors determining the epidemiology and population genetic structure of the bacillus cereus group in the field. plos pathogens, 2010 ; 6 ( 5 ) : e1000905 doi : 10. 1371 / journal. ppat. 1000905 note : if no author is given, the source is cited instead.


apr. 17, 2012 researchers from the complutense university of madrid ( ucm, spain ) have mathematically shown that particles charged in a magnetic field can escape into infinity without ever stopping. one of the conditions is that the field is generated by current loops situated on the same plane. at the moment this is a theoretical mathematical study, but two researchers from ucm have recently proved that, in certain conditions, magnetic fields can send particles to infinity, according to the study published in the journal quarterly of applied mathematics. " if a particle ' escapes ' to infinity it means two things : that it will never stop, and " something else, " antonio diaz - cano, one of the authors, explained. regarding the first, the particle can never stop, but it can be trapped, doing circles forever around a point, never leaving an enclosed space. however, the " something else " goes beyond the established limits. " if we imagine a spherical surface with a large radius, the particle will cross the surface going away from it, however big the radius may be " the researcher declares. scientists have confirmed through equations that some particles can escape infinity. one condition is that the charges move below the activity of a magnetic field created by current loops on the same plane. other requirements should also be met : the particle should be on some point on this plane, with its initial speed being parallel to it and far away enough from the loops. " we are not saying that these are the only conditions to escape infinity, there could be others, but in this case, we have confirmed that the phenomenon occurs, " diaz - cano states. " we would have liked to have been able to try something more general, but the equations are a lot more complex. " in any case, the researchers recognise that the ideal conditions for this study are " with a magnetic field and nothing else. " reality always has other variables to be considered, such as friction and there is a distant possibility of going towards infinity. nonetheless, the movement of particles in magnetic fields is a " very significant " problem in fields such as applied and plasma physics. for example, one of the challenges that the scientists that study nuclear energy face is the confinement of particles to magnetic fields. accelerators such as large hadron collider ( lhc ) of the european organisation for nuclear research ( cern ) also used magnetic fields to accelerate particles. in these conditions they do not escape to infinity, but they remain doing circles until they acquire the speed that the experiments need. other social book


oct. 25, 2012 japan ' s " triple disaster, " as it has become known, began on march 11, 2011, and remains unprecedented in its scope and complexity. to understand the lingering effects and potential public health implications of that chain of events, scientists are turning to a diverse and widespread sentinel in the world ' s ocean : fish. events on march 11 began with a magnitude 9. 0 earthquake, the fourth largest ever recorded. the earthquake in turn spawned a massive 40 - foot tsunami that inundated the northeast japanese coast and resulted in an estimated 20, 000 missing or dead. finally, the wave caused catastrophic damage to the fukushima dai - ichi nuclear power plant, resulting in the largest accidental release of radiation to the ocean in history, 80 percent of which ended up in the northwest pacific ocean. in a perspectives article appearing in october 26, 2012, issue of the journal science, whoi marine chemist ken buesseler analyzed data made publicly available by the japanese ministry of agriculture, forestry and fisheries ( maff ) on radiation levels in fish, shellfish and seaweed collected at ports and inland sites in and around fukushima prefecture. the picture he draws from the nearly 9, 000 samples describes the complex interplay between radionuclides released from fukushima and the marine environment. in it, buesseler shows that the vast majority of fish caught off the northeast coast of japan remain below limits for seafood consumption, even though the japanese government tightened those limits in april 2012. nevertheless, he also finds that the most highly contaminated fish continue to be caught off the coast of fukushima prefecture, as could be expected, and that demersal, or bottom - dwelling fish, consistently show the highest level of contamination by a radioactive isotope of cesium from the damaged nuclear power plant. he also points out that levels of contamination in almost all classifications of fish are not declining, although not all types of fish are showing the same levels, and some are not showing any appreciable contamination. as a result, buesseler concludes that there may be a continuing source of radionuclides into the ocean, either in the form of low - level leaks from the reactor site itself or contaminated sediment on the seafloor. in addition, the varying levels of contamination across fish types points to complex methods of uptake and release by different species, making the task of regulation and of communicating the reasons behind decision - making to the fish - hungry japanese public all the more difficult. " to predict the how patterns of


nov. 19, 2012 sound waves are commonly used in applications ranging from ultrasound imaging to hyperthermia therapy, in which high temperatures are induced, for example, in tumors to destroy them. in 2010, researchers at caltech led by chiara daraio, a professor of aeronautics and applied physics, developed a nonlinear acoustic lens that can focus high - amplitude pressure pulses into compact " sound bullets. " in that initial work, the scientists demonstrated how sound bullets form in solids. now, they have done themselves one better, creating a device that can form and control those bullets in water. the nonlinear acoustic lens is constructed from chains strung with stainless - steel spheres that are oriented parallel to one another - - and squeezed together - - to form an array. the gadget was inspired by newton ' s cradle, a popular toy that consists of a line of identical balls suspended by wires from a frame. when an end ball is pulled back and released, it slams into the next ball, causing the last ball in the line to fly outward. similarly, in the acoustic lens, striking one end of the array generates compact nonlinear pulses of sound - - solitary waves that propagate through the lens and can be tightly focused on a target area ; when they coalesce at this focal point, they produce a significantly amplified version : the sound bullet. these intense pressure waves may be used to obliterate tumors or kidney stones - - leaving surrounding tissues unharmed - - or probe objects like ship hulls or bridges for unseen defects. in the new work, the lens has been made more accurate, and a waterproof interface, which efficiently transmitted the pulses, was inserted between the chains and water. " we use water as a target medium with the idea that the acoustic lens could be used for underwater imaging and / or biomedical applications, " says postdoc carly donahue, who helped refine the device. " currently, our work is fundamental in nature. we are focused on demonstrating proof of principle and establishing the technical strengths and weaknesses, which will inform the future design of engineering devices for specific applications, " she adds. " for example, using these systems in biomedical applications requires reducing their dimensions and learning about the related scaling effects. creating commercially viable devices will require the involvement of industrial partners. " donahue discusses the technology and its potential applications in a talk at the aps division of fluid dynamics meeting, which will take place november 18 - 20, 2012 at the san diego convention center, located near the historic gaslamp district on the waterfront, in san


nov. 21, 2012 for the first time, researchers tracking the behavior of emperor penguins near the sea have identified the importance of sea ice for the penguins ' feeding habits. the research, published november 21 in the open access journal plos one by shinichi watanabe from fukuyama university, japan and colleagues, japan describes emperor penguin foraging behavior through the birds ' chick - rearing season. unlike other species like adelie penguins, emperor penguins spent much more time diving for food, and only used about 30 % of their time at sea to take short breaks to rest on sea ice. the birds did not travel for long distances on the ice, or use it for other activities. the study also suggests that these short rest periods on sea ice may help the penguins avoid predators such as leopard seals. though sea ice conditions are known to affect penguin populations, the relationship between ice levels and penguins ' foraging has been unclear because of the difficulties of tracking the birds at sea. watanabe says, " the monitoring technique developed in this study will help to understand the relationship. " other social bookmarking and sharing tools : the above story is reprinted from materials provided by public library of science. - shinichi watanabe, katsufumi sato, paul j. ponganis. activity time budget during foraging trips of emperor penguins. plos one, 2012 ; 7 ( 11 ) : e50357 doi : 10. 1371 / journal. pone. 0050357 note : if no author is given, the source is cited instead.


self - esteem and valentine ’ s day : reflections of a community organizer self - esteem as a celebration of one ’ s value as a human being is a basic self - interest. self - interest is not a bad word as many sectors in society would like to make you and me believe. in community organizing, a basic guiding principle is : people act on the basis of self - interest. if people are affected by a problem, they get angry or they are worried. let ’ s say your home at the foot of a mountain is at a place where a landslide is waiting to happen. of course, you think of a way to prevent a landslide from happening or you stay away from the danger area. danger makes people afraid or angry, depending on what causes the danger. fear, anger or any other emotion that threatens one ’ s survival makes a person act. survival is a self - interest. a parallel thought to self - interest is loving oneself. then, loving oneself is a selfish emotion, you may argue. the concept of “ selfishness ” needs to be decoded from the negative judgments most of us have been conditioned to believe from childhood. loving oneself as a so - called act of selfishness is different from self - centeredness. self - centeredness makes the self so big at the expense of others. actually, self - centeredness is an aversion to loving oneself for the nature of love is to radiate – from inside the self to others. loving oneself is the principle on which loving others is founded if we believe that we are part of society and therefore should be capable of letting our love flow into society. loving oneself, in fact, is an inherent individual responsibility. to illustrate this thought, here ’ s an actual experience of a young community organizer whose idea of loving oneself was just not a practice of community workers. this particular community organizer just arrived from a mobilization with the community. the time was 4 : 00 pm. she said she was very hungry as she had not taken her lunch because of the so many things she needed to attend to. the trainer of the young community organizer asked : how do you think you can help people take care of themselves when you yourself cannot look after your own self - interest? the young community organizer sheepishly replied : “ i thought i would be affirmed for postponing my lunch. ” the trainer continued : “ don ’ t display an irresponsibility ”. community organizers, if they are indeed community organizers, will know how to relate their self - interest with the self


digital cinema encompasses every aspect of the movie making process, from production and post - production to distribution and projection. a digitally produced or digitally converted movie can be distributed to theaters via satellite, physical media, or fiber optic networks. the digitized movie is stored by a computer / server which " serves " it to a digital projector for each screening of the movie. projectors based on dlp cinema® technology are currently installed in over 1, 195 theaters in 30 countries worldwide - and remain the first and only commercially available digital cinema projectors. when you see a movie digitally, you see that movie the way its creators intended you to see it : with incredible clarity and detail. in a range of up to 35 trillion colors. and whether you ' re catching that movie on opening night or months after, it will always look its best, because digital movies are immune to the scratches, fading, pops and jitter that film is prone to with repeated screenings. main advantage of digital movies are that, expensive film rolls and postprocessing expenses could be done away. movie would be transmitted to computers in movie theatres, hence the movie could be released in a larger number of theatres. technology has already taken over much of the home entertainment market. it seems strange, then, that the vast majority of theatrical motion pictures are shot and distributed on celluloid film, just like they were more than a century ago. of course, the technology has improved over the years, but it ' s still based on the same basic principles. the reason is simple : up until recently, nothing could come close to the image quality of projected film. digital cinema is simply a new approach to making and showing movies. the basic idea is to use bits and bytes ( strings of 1s and 0s ) to record, transmit and replay images, rather than using chemicals on film. the main advantage of digital technology ( such as a hyperlink " http : / / entertainment. howstuffworks. com / cd. htm " cd ) is that it can store, transmit and retrieve a huge amount of information exactly as it was originally recorded. analog technology ( such as an audio tape ) loses information in transmission, and generally degrades with each viewing. digital information is also a lot more flexible than analog information. a computer can manipulate bytes of data very easily, but it can ' t do much with a streaming analog signal. it ' s a completely different language. cinema affects three major areas of movie - making : " production - how the movie is actually


. a computer can manipulate bytes of data very easily, but it can ' t do much with a streaming analog signal. it ' s a completely different language. cinema affects three major areas of movie - making : " production - how the movie is actually made " distribution - how the movie gets from the production company " to movie theaters " projection - how the theater presents the movie with an $ 800 consumer digital camcorder, a stack of tapes, a computer and some video - editing software, you could make a digital movie. but there are a couple of problems with this approach. first, your image resolution won ' t be that great on a big movie screen. second, your movie will look like news footage, not a normal theatrical film. onventional video has a completely different look from film, and just about anybody can tell the difference in film and video differ a lot in image clarity, depth of focus and color range, but the biggest contrast is frame rate. film cameras normally shoot at 24 frames per second, while most u. s. television video cameras shoot at 30 frames per second ( 29. 97 per second, to be exact ). you may also like this : indoor geolocation, wireless dsl, wireless microserver, user identification through keystroke biometrics, ultrasonic motor, virtual retinal display, spectrum pooling, signaling system, ultra conductors, self phasing antenna array, role of internet technology in future mobile data system, service aware intelligent ggsn, push technology, gmpls, fluorescent multi - layer disc, compact peripheral component interconnect ( cpci ), datalogger, wideband sigma delta pll modulator, voice morphing, visnav, speed detection of moving vehicle using speed cameras, optical switching, optical satellite communication, optical packet switching network, satrack, crusoe processor, radio frequency light sources, qos in cellular networks based on mpt, project oxygen, polymer memory, navbelt and guidicane, multisensor fusion and integration, moct, mobile virtual reality service, smart pixel arrays, adaptive blind noise suppression, an efficient algorithm for iris pattern, analog - digital hybrid modulation, artificial intelligence substation control, speech compression - a novel method, class - d amplifiers, digital audio ' s final frontier - class d amplifier, optical networking and dense wavelength division multiplexing, optical burst switching, bluetooth based smart sensor networks, laser communications, cordect, e - intelligence, white led,


gas in the digestive tract - the esophagus, stomach, small intestine, and large intestine? comes from two sources : swallowed air : aerophagia, or air swallowing, is a common cause of gas in the stomach. everyone swallows small amounts of air when eating and drinking. however, eating or drinking rapidly, chewing gum, smoking, or wearing loose dentures can cause some people to take in more air. burping, or belching, is the way most swallowed air - which contains nitrogen, oxygen, and carbon dioxide - leaves the stomach. the remaining gas moves into the small intestine, where it is partially absorbed. a small amount travels into the large intestine for release through the rectum. the stomach also releases carbon dioxide when stomach acid mixes with the bicarbonate in digestive juices, but most of this gas is absorbed into the bloodstream and does not enter the large intestine. breakdown of undigested foods : the body does not digest and absorb some carbohydrates - the sugar, starches, and fiber found in many foods - in the small intestine because of a shortage or absence of certain enzymes that aid digestion. this undigested food then passes from the small intestine into the large intestine, where normal, harmless bacteria break it down, producing hydrogen, carbon dioxide, and, in about one - third of all people, methane. eventually, these gases exit through the rectum. people who make methane do not necessarily pass more gas or have unique symptoms. a person who produces methane will have stools that consistently float in water. research has not shown why some people produce methane and others do not. foods that produce gas in one person may not cause gas in another. some common bacteria in the large intestine can destroy the hydrogen that other bacteria produce. the balance between the two types of bacteria may explain why some people produce more gas than others do. this answer is based on source information from the national institute of diabetes and digestive and kidney diseases. gas in the digestive tract - the esophagus, stomach, small intestine, and large intestine? comes from two sources : swallowed air : aerophagia, or air swallowing, is a common cause of gas in the stomach. everyone swallows small amounts of air when eating... more dr. lawrence friedman answered : the air we breathe is made up mostly of nitrogen ( n2 ) and oxygen ( o2


air swallowing, is a common cause of gas in the stomach. everyone swallows small amounts of air when eating... more dr. lawrence friedman answered : the air we breathe is made up mostly of nitrogen ( n2 ) and oxygen ( o2 ), the gas the human body needs to sustain life. after being swallowed, air enters the gastrointestinal ( gi ) tract. as it moves along, its makeup changes as oxygen passes into the blood and nitrogen is removed from the blood. another intestinal gas is carbon dioxide ( co2 ), a byproduct of a chemical reaction with acid in the stomach. hydrogen ( h2 ) is released in the colon when undigested carbohydrates undergo bacterial fermentation. bacteria in the gut produce foul - smelling gases when they ferment undigested foods that have not been absorbed in the small intestine. these foods consist mostly of carbohydrates, sugars, and fats. the carbohydrates found in high - fiber foods, such as beans, broccoli, cauliflower, and brussels sprouts, are the worst culprits. these foods release gases such as methane and hydrogen sulfide, which smells like rotten eggs. the worst odor is related to strong - smelling sulfurs that make up just 1 % of flatus ( gas that escapes from the rectum ). methane is detected in about one - third of adults. studies show that americans and europeans are more likely to produce methane than asians are, possibly because of diet. women also produce more than men do. genes may play a role in methane production, as the trait is passed along in families. additional carbon dioxide is produced in the colon as the byproduct of bacterial fermentation of unabsorbed sugars and starches. eating beans will substantially increase co2 production, as will taking sodium bicarbonate for heartburn. thus, it doesn ' t make sense to use bicarbonate - containing seltzers for gas. the air we breathe is made up mostly of nitrogen ( n2 ) and oxygen ( o2 ), the gas the human body needs to sustain life. after being swallowed, air enters the gastrointestinal ( gi ) tract. as it moves along, its makeup changes as oxygen passes into... more


wool is comfortable to wear year - round because it ' s an absorbent fiber that helps regulate body temperature. ( when the air is cool and damp, wool absorbs moisture and keeps a layer of dry, insulating air next to the skin. conversely, when it ' s warm, that same absorption capacity takes up perspiration, making the body ' s natural cooling system work better. ) woolen garments are a great investment. since wool fibers resist pilling, snagging and breaking, woolen garments typically outlast synthetic sweaters. furthermore, since wool fibers are naturally elastic, woolen garments don ' t wrinkle, bag or sag out of shape. wool is a safe fabric - - it is the only fiber that naturally resists flaming. unlike most artificial fibers, which often melt and stick to the skin when on fire, wool usually only smolders or chars. although it will burn under intense fire, it normally self - extinguishes when the flame source is removed. many consumer safety experts advocate wearing woolen garments when flying. the u. s. sheep industry traditionally focuses on wool during the spring months. in fact, approximately 63 percent of american - produced wool is shorn during april, may and june. in 1999, the u. s. sheep industry produced approximately 46. 5 million lbs. of wool. american wool has many uses. in addition to its well - known uses in clothing, fabrics, yarn, felt and carpet, american wool is used to make insulation, rug pads, baseballs and tennis balls. some of the major wool processors in the united states include burlington, pendleton, forstmann and chargeurs. u. s. mills must purchase australian and new zealand wool in order to meet their wool needs. australia provides mostly finer wool, which is used in making apparel, while new zealand provides mostly coarser wool, which is used in making numerous industrial and home interior products. although the united states buys australian wool, it is not even in australia ' s top 10 destinations. china and hong kong are the largest wool buyers, regardless of where the wool is produced. together, the two countries annually purchase approximately 20 percent of the world ' s wool clip. italy is the second largest user of australian wool, purchasing approximately half as much as australia and new zealand combined. since the u. s. wool clip most closely resembles australian clip, u. s. wool prices most closely mirror australian wool prices. asia also plays a major role in determining the price of


once upon a time there was a school situated in the middle of a very big city and surrounded by very busy roads. the children would often run out of school and start playing, not realising how dangerous it was to have a road so close by. there had already been accidents when children crossed the road without looking, or when they ran around near the traffic lights. to stop this happening again, a local traffic light thought to himself : “ why don ’ t i warn the children by shouting when cars are coming? or perhaps i should grab them by the backpack …? ” he thought this would be a very good idea, so he told his friend the zebra crossing. but the zebra crossing said : “ if we do that, we will only cause children in a different neighbourhood to have an accident, because they will rely on us to save them. but we won ’ t be there! ” the traffic light thought this through, and realised that the zebra crossing was right. so they decided to do something different : “ from now on, every day we ’ ll explain to each child the dangers of crossing the road without looking, and we ’ ll use videos so they can see the dangers for themselves. ” once they understood that it had to be the children themselves who acted sensibly, they told all other traffic lights and pedestrian crossings, and then these told others and so on and so forth until all the traffic lights and pedestrian crossings in the city knew. and after three months, all the children in all the schools were very careful when they went out onto the street, and there was never an accident in the city again. the traffic light and the zebra crossing had made the children realise how dangerous roads can be, and they were delighted to have taught them to follow the basic rules of road safety.


person centered therapy by saul mcleod published 2008 humanistic therapies evolved in the usa in the 1950s. carl rogers proposed that therapy could be simpler, warmer and more optimistic than that carried out by behavioral or psychodynamic psychologists. his view differs sharply from the psychodynamic and behavioral approaches in that he suggested that clients would be better helped if they were encouraged to focus on their current subjective understanding rather than on some unconscious motive or someone else ' s interpretation of the situation. rogers strongly believed that in order for a client ' s condition to improve therapists should be warm, genuine and understanding. the starting point of the rogerian approach to counseling and psychotherapy is best stated by rogers ( 1986 ) himself. " it is that the individual has within himself or herself vast resources for self - understanding, for altering his or her self - concept, attitudes and self - directed behavior - and that these resources can be tapped if only a definable climate of facilitative psychological attitudes can be provided. " rogers rejected the deterministic nature of both psychoanalysis and behaviorism and maintained that we behave as we do because of the way we perceive our situation. " as no one else can know how we perceive, we are the best experts on ourselves. " ( gross, 1992 ) believing strongly that theory should come out of practice rather than the other way round, rogers developed his theory based on his work with emotionally troubled people and claimed that we have a remarkable capacity for self - healing and personal growth leading towards self - actualization. he placed emphasis on the person ' s current perception and how we live in the here - and - now. rogers noticed that people tend to describe their current experiences by referring to themselves in some way, for example, " i don ' t understand what ' s happening " or " i feel different to how i used to feel ". central to rogers ' ( 1959 ) theory is the notion of self or self - concept. this is defined as " the organized, consistent set of perceptions and beliefs about oneself ". it consists of all the ideas and values that characterize ' i ' and ' me ' and includes perception and valuing of ' what i am ' and ' what i can do '. self concept is a central component of our total experience and influences both our perception of the world and perception of oneself. for instance, a woman who perceives herself as strong may well behave with confidence and come to see her actions as actions performed by someone who is confident. the self - concept does not necessarily