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X-ray fluorescence induced by charged particles has been employed in trace element analysis of both animal and human blood, tissue and bone samples. Preparation techniques included microtome slicing and wet digestion in nitric acid, internal chemical standards being used in the latter case.
Most of the specimens arose from a study of interactions between the toxic elements lead and zinc in growing foals; this was motivated by reports of sickness and death in foals raised near lead-zinc smelters. The cause of toxicity in animals from environmental pollution is often attributed to Single factors, whereas in reality interactions among many factors, including a variety of toxic and nutrient trace elements, should be considered.
A variety of spectra are presented and elemental concentrations derived. Agreement between the X-ray data and atomic absorption spectrophotometry is encouraging. The results demonstrate the potential of particle-excited X-ray fluorescenee as a broad-range analytical technique for the study of trace element interactions.
Small Island Developing States (SIDS) are island nations that experience specific social, economic and environmental vulnerabilities associated with small populations, isolation and limited resources. Globally, SIDS exhibit exceptionally high rates of non-communicable disease (NCD) risk and incidence. Despite this, there is a lack of context-specific research within SIDS focused on life course approaches to NCD prevention, particularly the impact of the early-life environment on later disease risk as defined by the Developmental Origins of Health and Disease (DOHaD) framework. Given that globalization has contributed to significant nutritional transitions in these populations, the DOHaD paradigm is highly relevant. SIDS in the Pacific region have the highest rates of NCD risk and incidence globally. Transitions from traditional foods grown locally to reliance on importation of Western-style processed foods high in fat and sugar are common. The Cook Islands is one Pacific SIDS that reports this transition, alongside rising overweight/obesity rates, currently 91%/72%, in the adult population. However, research on early-life NCD prevention within this context, as in many low- and middle-income countries, is scarce. Although traditional research emphasizes the need for large sample sizes, this is rarely possible in the smaller SIDS. In these vulnerable, high priority countries, consideration should be given to utilizing ‘small’ sample sizes that encompass a high proportion of the total population. This may enable contextually relevant research, crucial to inform NCD prevention strategies that can contribute to improving health and well-being for these at-risk communities.
Introduction: Bed boarding of admitted patients in the Emergency Department (ED) is widely recognized as a major contributor to overcrowding, particularly in very high-volume hospitals. The issue of bed boarding is directly tied to hospital-wide capacity, flow and operations. Early morning discharge from inpatient units has been identified as a low-cost intervention to decrease bed boarding, as it allows earlier transfer of admitted patients from the ED. Several hospitals have instituted discharge before noon, or discharge before 10AM policies, practices and targets. Our objectives were 1) to assess the current status of flow within 3 high-volume community hospitals with respect to time of day of discharges from the in-patient units and time of day of transfers from the ED to in-patient units, and 2) to assess the association between time of transfer from the ED and total ED Length of Stay (EDLOS) of admitted patients. Methods: We conducted a retrospective multi-centre observational study during the period of January 1, 2015 to December 31, 2015 at three high-volume community hospitals within Ontario, Canada. All patients admitted to the Medicine service were identified. Time of discharge from the in-patient units and time of transfer from the ED were collected for all patients. EDLOS was calculated for all patients as a function of time of transfer from the ED. Results: Preliminary findings show that, for the three community hospitals, only 11.7% - 19.6% of admitted patients were discharged from the in-patient units during the period between 6AM and 12PM, with a peak discharge time of 2PM in all three hospitals. A concurrent lag was observed in the time of transfer of patients from the ED, with peak transfer times occurring the late afternoon between 3PM and 9PM, and coinciding with a peak in patient volume in the ED. Patients transferred out of the ED earlier in the day (between 12AM 11:59AM) had between 1.4 hours to 8.0 hours lower mean EDLOS when compared to those patients transferred later in the day (between 12PM 11:59PM). Conclusion: Hospital-wide flow and operational issues have a significant impact on ED bed boarding, and potential efficiencies seem at the current time to be underutilized. Interventions aimed at optimizing flow must be implemented alongside those aimed at increasing capacity in order to improve bed boarding. ** These findings are best communicated in graphic form to better represent the dynamics of the flow in and out of the ED over a 24-hour period, and will be presented in graphic format if selected for the conference.
Introduction: Delays in transfer to an in-patient bed of admitted patients boarded in the ED has been identified as one of the chief drivers of ED overcrowding. Our study aims to replicate findings from a previous study in identifying patient characteristics associated with increased boarding time, and the impact of increased boarding time on in-patient length of stay (IPLOS). Methods: We conducted a retrospective single-centre observational study during the period between January 1, 2015 December 31, 2015 at a very high volume community hospital (~ 75,000 ED visits/year). All patients admitted from the ED to Medicine, Pediatrics, Surgery, and Critical Care were identified. The mean time to in-patient bed (TTB), as well as patient-specific and institutional factors that were associated with prolonged boarding times ( 12 hours) were identified. Mean IP LOS was calculated for those with prolonged boarding times and compared to those without prolonged boarding times. Results: There were 8,096 unique admissions during the study period. Patients admitted to the Medicine service exhibited significantly higher boarding times than those admitted to other services, with a mean boarding time of 17.4 hrs, as compared to 4.2 hrs, 5.7 hrs, and 4.0 hrs for those admitted to Surgery, Critical Care and Pediatrics respectively. Within Medicine patients, there was a statistically significant greater odds of prolonged boarding time for patients who were older, had a greater comorbidity burden, and required more specialized in-patient care (i.e. an isolation bed or telemetry bed). Medicine patients with prolonged boarding times also experienced 0.7 days longer IP LOS, even after correcting for age and comorbidity (mean adjusted IP LOS 10.6 days versus 11.3 days). Conclusion: Within our study period, older, sicker patients and those patients requiring more resource-intensive in-patient care have the longest ED boarding times. These prolonged ‘boarding’ times are associated with significantly increased IP LOS.
The first results from surveys performed in the extreme ultraviolet (EUV) will be described in the context of studies of active galaxies and BL Lac objects. About a dozen extra-galactic sources are known so far to emit sufficient EUV radiation that they are detectable even through the Galactic interstellar medium. These results are interpreted in the context of a model of EUV or soft X-ray excesses in the case of AGN. In the case of BL Lac objects, the detections indicate that the steep soft X-ray power law spectra continue into the EUV and that there is little intrinsic gas. Finally, there now exists EUV spectra from the Extreme Ultraviolet Explorer for one BL Lac, PKS 2155-304 and two AGN: Mk 478 and NGC 5548. The spectra show no significant spectral features; for AGN, it indicates that optically thin and emission line models may have a difficult time explaining the EUV and soft X-ray bumps.
Data from several collaborations will be shown which demonstrate the utility of EUVE observations. For Mk 478, a Seyfert 1 galaxy, the rapidly variable EUV flux is shown to have a steep, featureless continuum. The EUV data are combined with UV and optical data to form an overall spectrum that is consistent with an accretion disk model; slight temperature variations in the innermost regions could cause the large EUV flux changes. EUVE data for other sources are presented: NGC 5548, which shows significant variations and has an EUV spectrum that shows no emission lines, contrary to a previous report; 3C 273, which did not vary much; and PKS 2155-304, which was observed simultaneously with ASCA and IUE when a hard X-ray flare was detected as an EUV polarization measurement was being attempted.
The issues surrounding the legal status of Namibia and the numerous actions taken within the United Nations General Assembly and the Security Council relating to the revocation of the mandate of South Africa, are complex, and even the 1971 Opinion of the International Court of Justice has not simplified them. Much of the difficulty in determining the present juridical status of Namibia and the repository of sovereign authority over the territory revolves around the apparent inconsistencies between the 1950 Advisory Opinion of the Court and its 1971 Opinion. In this regard, the essential factor to be considered is the binding effect of the resolution of the General Assembly in 1966 that purported to terminate South Africa’s Mandate over Namibia.
The major international legal activity in the field of maritime transport in the first half of the 1970's was the negotiation and eventual adoption in 1974 under the auspices of the United Nations Conference on Trade and Development (U.N.C.T.A.D.) of the Convention on a Code of Conduct for Liner Conferences. The treaty-making conference itself, convened in Geneva, Switzerland, was attended by over eighty states members of U.N.C.T.A.D., including, of course, all the major trading nations, as well as by many observer delegations from U.N.C.T.A.D. member states, specialized agencies, and non-governmental and intergovernmental organizations.
The first Einstein observations established that quasars, as a class, are luminous X-ray emitters (Tananbaum et al. 1979). Since then, one of our major programs has been to carry out further X-ray and optical observations to improve our estimate of the contribution of quasars to the 2 keV extragalactic isotropic X-ray background and also to reconcile number counts of discrete X-ray sources with reported optical number counts of quasars (cf. Zamorani et al. 1981 and references therein). This paper is a preliminary report on our observations of the 1.7 square degree field studied originally by Braccesi and his colleagues (Formiggini et al. 1980 and Braccesi et al. 1980). A more detailed presentation of our results is in preparation (Marshall et al., 1981).
The analysis of the sunlight scattered by Venus gives some insight upon its clouds. The measurements of polarized light are probably more sensitive to the nature of their constituents, and some recent studies seem to be able to give a satisfactory interpretation of this part of the scattered light. But the polarized light concerns the upper part of the clouds, and it is interesting to compare these results with intensity measurements. The phase curves, for the integrated light, leave some indeterminations, so we have studied if the intensity distribution on the Venus disk could give more accurate informations. This work, based on some plates kindly communicated by A. Dollfus, and analysed at Meudon Observatory, is more a preliminary investigation of the sensitivity of the method than an interpretation of the partial results presented. A simple model, of homogeneous plane parallel cloud, has been used, and the influence of various parameters has been tested (single scattering albedo, refractive index of particles and size distribution, optical depth of the cloud).
Leafy vegetables are an essential component of a healthy diet; however, they have been associated with high-profile outbreaks causing severe illnesses. We reviewed leafy vegetable-associated outbreaks reported to the Centers for Disease Control and Prevention between 1973 and 2012. During the study period, 606 leafy vegetable-associated outbreaks, with 20 003 associated illnesses, 1030 hospitalizations, and 19 deaths were reported. On average, leafy vegetable-associated outbreaks were larger than those attributed to other food types. The pathogens that most often caused leafy vegetable-associated outbreaks were norovirus (55% of outbreaks with confirmed aetiology), Shiga toxin-producing Escherichia coli (STEC) (18%), and Salmonella (11%). Most outbreaks were attributed to food prepared in a restaurant or catering facility (85%). An ill food worker was implicated as the source of contamination in 31% of outbreaks. Efforts by local, state, and federal agencies to control leafy vegetable contamination and outbreaks should span from the point of harvest to the point of preparation.
In both its versions the Marduk Ordeal text states that “enūma eliš, which is recited and chanted before Bel in Nisan, concerns his imprisonment”. Diverse clever and mostly correct interpretations of this somewhat weird statement have been offered, generally dwelling on the obvious attempt at Assyrianising Babylonian lore (and dogma) underlying this text and related material. These explanations, however, seem to overlook an important point: the statement is simply untrue. This is in stark contrast with the other unequivocal mention of enūma eliš: the reference to Anšar in MO A. 1. 54, who is presented having come into being before heaven and earth were created. The reason why this notion is taken over wholesale seems simple: to an Assyrian audience the identity between AN.ŠAR and the god Aššur (probably via *aššar — an almost universal assimilation feature of Akkadian) will have been obvious and convincing. It should be noted that Bel's defence in MO A 1. 35 “I only did what was beneficent to Aššur” also hinges on this identification. But this leaves us with the palpable untruth of 1. 34. How is this to be understood? I suggest that no answer to this question should be attempted without taking into account the text as a whole, and in particular its specific and highly idiosyncratic texture and structure.
The text is made up from bits of different types of discourse, strung together very loosely and without any apparent structure. The prevalent types are:
1. short bits of apparently narrative material, such as “Bēlet-ilī, who roams the streets, is looking for Marduk (saying:) ‘Where is he kept prisoner?’”;
2. short point-to-point equivalencies of disparate materials, such as “The dog which crosses Esabad is a messenger. Gula is sending it to him”;
3. somewhat longer passages explaining some point by reference to other texts (the note about Bel's imprisonment seems to belong to this group).
The most common housing system for reproduction rabbits, individual cage housing on a wire floor, is increasingly scrutinized because of its potential detrimental impact on animal welfare. We compared three types of housing: (1) individual cage housing on a wire floor (3952 cm2/doe, maximum roof height 63 cm, one 1000 cm2 plastic footrest/doe), (2) semi-group housing on a wire floor (5000 cm2/doe, roofless, one 1000 cm2 plastic footrest/doe) and (3) the same semi-group housing, but with a fully plastic slatted floor. In all housing systems, does had free access to an elevated platform. In the semi-group housing pens, four does were housed communally during 21 days of the reproduction cycle (to allow more space for locomotion and to increase opportunities for social contact), and individually during the other 21 days of the cycle (to minimize doe–doe and doe–kit aggression that peaks around kindling). In all, 24 Hycole does were included per system. The does entered the experiment at 203 days of age (after their first parity). The experiment consisted of four reproductive cycles, ending at 369 days of age. Pododermatitis was scored in cycles 1, 2 and 4. At the end of the 4th cycle the does were euthanized and X-rays were taken to assess spinal deformation. Tibia and femur length, width and cortical thickness were determined and bone strength was assessed using a shear test, as a measure of bone quality. Although severe pododermatitis was absent, the prevalence of plantar hyperkeratosis (hair loss and callus formation) at the end of the 4th cycle was much greater on the wire floor (65% and 68% for semi-group housing and individual cages, respectively) than on the plastic floor (5%, P<0.0001), even though the wire floors were equipped with a plastic footrest known to decrease hyperkeratosis. In contrast to our expectations, semi-group housing did not affect the prevalence of spinal deformations (P>0.10), but in line with our expectations bone quality was affected favourably by semi-group housing. The tibial cortex (and to a lesser extent the femoral cortex) was thicker in semi-group housing than in individual cages (1.45, 1.46 and 1.38 mm for semi-group housing on wire, semi-group housing on plastic and individual housing on wire, respectively, P=0.045). What this increase in cortical thickness means in terms of doe welfare requires further study, as it may reflect an increase in activity resulting either from increased space for locomotion, or from fleeing aggressive pen mates.
Recent research has shown that many students continue to understand phenomena in simplified or unproductive ways, even after those understandings are directly contradicted in educational settings (Hake, 1998; Miller et al., 2006). In the context of engineering education, many engineering graduates still do not understand the foundational concepts of solid and fluid mechanics, physics, thermodynamics, digital logic, or other fields. The study of conceptual change and misconceptions is one attempt to understand and address this issue.
Because this field of study is fractious and diverse, we briefly establish some shared vocabulary and understanding of the fundamental processes underlying conceptual change and misconceptions. The following section introduces three primary theories of conceptual change: curriculum, measurement, and theory-focused efforts in engineering education. The chapter concludes with a brief summary and discussion of future directions for research.
We must define conceptual understanding somewhat carefully for our terminology to be useful across the various theoretical frameworks discussed in this chapter. An individual’s conceptual understanding of a topic is the collection of his or her concepts, beliefs, andmental models, where the following definitions apply:
Concepts are pieces or clusters of knowledge, for example, “force,” “mass,” “causation,” and “acceleration.”
Beliefs Concepts are pieces or clusters of knowledge, for example, “force,” “mass,” “causation,” and “acceleration.”
Mental models are groups of meaningfully related beliefs and concepts that allow people to explain phenomena and make predictions; for example, an expert dynamics instructor would use her mental model of Newtonian physics to predict an object’s motion.
Non-O157 Shiga toxin-producing Escherichia coli (STEC) infections are increasingly detected, but sources are not well established. We summarize outbreaks to 2010 in the USA. Single-aetiology outbreaks were defined as ⩾2 epidemiologically linked culture-confirmed non-O157 STEC infections; multiple-aetiology outbreaks also had laboratory evidence of ⩾2 infections caused by another enteric pathogen. Twenty-six states reported 46 outbreaks with 1727 illnesses and 144 hospitalizations. Of 38 single-aetiology outbreaks, 66% were caused by STEC O111 (n = 14) or O26 (n = 11), and 84% were transmitted through food (n = 17) or person-to-person spread (n = 15); food vehicles included dairy products, produce, and meats; childcare centres were the most common setting for person-to-person spread. Of single-aetiology outbreaks, a greater percentage of persons infected by Shiga toxin 2-positive strains had haemolytic uraemic syndrome compared with persons infected by Shiga toxin 1-only positive strains (7% vs. 0·8%). Compared with single-aetiology outbreaks, multiple-aetiology outbreaks were more frequently transmitted through water or animal contact.