967 resultados para Average of min and max value
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Glycolipids are prominent constituents in the membranes of cells from all domains of life. For example, diglycosyl-glycerol dibiphytanyl glycerol tetraethers (2Gly-GDGTs) are associated with methanotrophic ANME-1 archaea and heterotrophic benthic archaea, two archaeal groups of global biogeochemical importance. The hydrophobic biphytane moieties of 2Gly-GDGTs from these two uncultivated archaeal groups exhibit distinct carbon isotopic compositions. To explore whether the isotopic compositions of the sugar headgroups provide additional information on the metabolism of their producers, we developed a procedure to analyze the d13C values of glycosidic headgroups. Successful determination was achieved by (1) monitoring the contamination from free sugars during lipid extraction and preparation, (2) optimizing the hydrolytic conditions for glycolipids, and (3) derivatizing the resulting sugars into aldononitrile acetate derivatives, which are stable enough to withstand a subsequent column purification step. First results of d13C values of sugars cleaved from 2Gly-GDGTs in two marine sediment samples, one containing predominantly ANME-1 archaea and the other benthic archaea, were obtained and compared with the d13C values of the corresponding biphytanes. In both samples the dominant sugar headgroups were enriched in 13C relative to the corresponding major biphytane. This 13C enrichment was significantly larger in the putative major glycolipids from ANME-1 archaea (~15 per mil) than in those from benthic archaea (<7 per mil). This method opens a new analytical window for the examination of carbon isotopic relationships between sugars and lipids in uncultivated organisms.
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Compositional data for coexisting manganese nodules, micronodules, sediments and pore waters from five areas in the equatorial and S.W. Pacific have been obtained. This represents the largest study of its type ever undertaken to establish the distribution of elements between the various phases within the sediment column. The composition of manganese nodules, micronodules and sediments (on a carbonate-free basis) shows marked differences between the equatorial high productivity zone and the low productivity region of the S.W. Pacific. In the case of the nodules, th is reflects an increased supply of transition elements (notably Ni, Cu and Zn) to the nodules as a result of the in situ dissolution of siliceous tests within the sediment column in the equatorial Pacific high productivity zone. Micronodules display similar, but somewhat different, compositions to those of the associated nodules in each area. Micronodule composition is therefore influenced by the same basic factors that control nodule composition, but is modified by dissolution of the micronodules in situ within the sediment column. Locally, as in the area immediately south of the Marquesas Fracture Zone, the micronodule population is contaminated by small, angular volcanic rock fragments; this leads to apparently anomalous micronodule compositions. Micronodules appear to be a transient feature in the sediment column, especially in the equatorial Pacific. Dissolution of micronodules in the sediment column therefore represents an important source of elements for the growth of manganese nodules in the equatorial Pacific. Sediment composition is markedly influenced by the carbonate content. On a carbonate-free basis, the sediments from the equatorial high productivity zone are quite distinct in composition from those in the S.W. Pacific. This reflects differences in the lithology of the sediments. In the Aitutaki Passage, the local influence of volcanoclastic material in sediment composition has been established. The major cations and anions in pore waters measured here show no major differences between equatorial and S.W. Pacific sediments. Silica is, however, higher in equatorial Pacific pore waters reflecting the dissolution of siliceous tests in these sediments.
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The stable hydrogen isotope composition of lipid biomarkers, such as alkenones, is a promising new tool for the improvement of palaeosalinity reconstructions. Laboratory studies confirmed the correlation between lipid biomarker dD composition (dDLipid), water dD composition (dDH2O) and salinity; yet there is limited insight into the applicability of this proxy in oceanic environments. To fill this gap, we test the use of the dD composition of alkenones (dDC37) and palmitic acid (dDPA) as salinity proxies using samples of surface suspended material along the distinct salinity gradient induced by the Amazon Plume. Our results indicate a positive correlation between salinity and dDH2O, while the relationship between dDH2O and dDLipid is more complex: dDPAM correlates strongly with dDH2O (r2 = 0.81) and shows a salinity-dependent isotopic fractionation factor. dDC37 only correlates with dDH2O in a small number (n = 8) of samples with alkenone concentrations > 10 ng L**-1, while there is no correlation if all samples are taken into account. These findings are mirrored by alkenone-based temperature reconstructions, which are inaccurate for samples with low alkenone concentrations. Deviations in dDC37 and temperature are likely to be caused by limited haptophyte algae growth due to low salinity and light limitation imposed by the Amazon Plume. Our study confirms the applicability of dDLipid as a salinity proxy in oceanic environments. But it raises a note of caution concerning regions where low alkenone production can be expected due to low salinity and light limitation, for instance, under strong riverine discharge.
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The book summarizes materials obtained by Soviet scientists during participation in legs of D/S Glomar Challenger and in post-cruise studies. Results on stratigraphy and lithology of the sedimentary cover, petrography and geochemistry of magmatic rocks of the oceanic crust are discussed in the book. A modern analysis of the geophysical structure of the oceanic crust and of the tectonic structure of the ocean floor is given.
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Purpose - The roles of ‘conventional’ (fixed-route and fixed-timetable) bus services is examined and compared to demand-responsive services, taking rural areas in England as the basis for comparison. It adopts a ‘rural’ definition of settlements under a population of 10,000. Design/methodology/approach - Evidence from the National Travel Survey, technical press reports and academic work is brought together to examine the overall picture. Findings - Inter-urban services between towns can provide a cost-effective way of serving rural areas where smaller settlements are suitably located. The cost structures of both fixed-route and demand-responsive services indicate that staff time and cost associated with vehicle provision are the main elements. Demand-responsive services may enable larger areas to be covered, to meet planning objectives of ensuring a minimum of level of service, but experience often shows high unit cost and public expenditure per passenger trip. Economic evaluation indicates user benefits per passenger trip of similar magnitude to existing average public expenditure per trip on fixed-route services. Considerable scope exists for improvements to conventional services through better marketing and service reliability. Practical implications - The main issue in England is the level of funding for rural services in general, and the importance attached to serving those without access to cars in such areas. Social implications - The boundary between fixed-route and demand-responsive operation may lie at relatively low population densities. Originality/value - The chapter uses statistical data, academic research and operator experience of enhanced conventional bus services to provide a synthesis of outcomes in rural areas.
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Highly swellable polymer films doped with Ag nanoparticle aggregates (poly-SERS films) have been used to record very high signal:noise ratio, reproducible surface-enhanced (resonance) Raman (SER(R)S) spectra of in situ dried ink lines and their constituent dyes using both 633 and 785 nm excitation. These allowed the chemical origins of differences in the SERRS spectra of different inks to be determined. Initial investigation of pure samples of the 10 most common blue dyes showed that the dyes which had very similar chemical structures such as Patent Blue V and Patent Blue VF (which differ only by a single OH group) gave SERRS spectra in which the only indications that the dye structure had been changed were small differences in peak positions or relative intensities of the bands. SERRS studies of 13 gel pen inks were consistent with this observation. In some cases inks from different types of pens could be distinguished even though they were dominated by a single dye such as Victoria Blue B (Zebra Surari) or Victoria Blue BO (Pilot Acroball) because their predominant dye did not appear in other inks. Conversely, identical spectra were also recorded from different types of pens (Pilot G7, Zebra Z-grip) because they all had the same dominant Brilliant Blue G dye. Finally, some of the inks contained mixtures of dyes which could be separated by TLC and removed from the plate before being analysed with the same poly-SERS films. For example, the Pentel EnerGel ink pen was found to give TLC spots corresponding to Erioglaucine and Brilliant Blue G. Overall, this study has shown that the spectral differences between different inks which are based on chemically similar, but nonetheless distinct dyes, are extremely small, so very close matches between SERRS spectra are required for confident identification. Poly-SERS substrates can routinely provide the very stringent reproducibility and sensitivity levels required. This, coupled with the awareness of the reasons underlying the observed differences between similarly coloured inks allows a more confident assessment of the evidential value of inks SERS and should underpin adoption of this approach as a routine method for the forensic examination of inks.
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Poly N-vinylcaprolactam-co-acrylamidophenylboronic acid p(NVCL-co-AAPBA) was prepared from N-vinylcaprolactam (NVCL) and 3-acrylamidophenylboronic acid (AAPBA), using 2,2-azobisisobutyronitrile (AIBN) as initiator. The synthesis and structure of the polymer were examined by Fourier Transform infrared spectroscopy (FT-IR) and 1H-NMR. Dynamic light scattering (DLS), lower critical solution temperature (LCST) and transmission electron microscopy (TEM) were utilized to characterize the nanoparticles, CD spectroscopy was used to determine if there were any changes to the conformation of the insulin, and cell and animal toxicity were also investigated. The prepared nanoparticles were found to be monodisperse submicron particles and were glucose- and temperature-sensitive. In addition, the nanoparticles have good insulin-loading characteristics, do not affect the conformation of the insulin and show low-toxicity to cells and animals. These p(NVCL-co-AAPBA) nanoparticles may have some value for insulin or other hypoglycemic protein delivery.
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The goal of WorldFish’s research on markets and value chains is to increase the benefits to resource-poor people from fisheries and aquaculture value chains by researching (1) key barriers to resource-poor men, women and other marginalized groups gaining greater benefits from participation in value chains, including barriers related to the availability, affordability and quality of nutrient-rich fish for resource-poor consumers; (2) interventions to overcome those barriers; and (3) mechanisms that are most effective for scaling up of value chain interventions. This paper aims to promote and document learning across WorldFish’s value chain research efforts in Asia and Africa. It has three main objectives: (1) to take stock of WorldFish’s past and ongoing research on value chains; (2) to draw out commonalities and differences between these projects; and (3) to provide a synthesis of some learning that can guide future work.
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In vivo and in vitro experiments were conducted to determine digestibility of GE and nutrients, as well as DE and ME of carbohydrates fed to growing pigs. The objective of Exp. 1 was to determine the DE and ME of 4 novel carbohydrates fed to pigs. The 4 novel carbohydrates were 2 sources of resistant starch (RS 60 and RS 70), soluble corn fiber (SCF), and pullulan. These carbohydrates were produced to increase total dietary fiber (TDF) intake by humans. Maltodextrin (MD) was used as a highly digestible control carbohydrate. The DE and ME for RS 60 (1,779 and 1,903 kcal/kg, respectively), RS 75(1,784 and 1,677 kcal/kg, respectively), and SCF (1,936 and 1,712 kcal/kg, respectively) were less (P < 0.05) than for MD (3,465 and 3,344 kcal/kg, respectively) and pullulan (2,755 and 2,766 kcal/kg, respectively), and pullulan contained less (P < 0.05) DE and ME than MD. However, there was no difference in the DE and ME for RS 60, RS 75, and SCF. The varying degrees of small intestinal digestibility and differences in fermentability among these novel carbohydrates may explain the differences in the DE and ME among carbohydrates. Therefore, the objectives of Exp. 2 were to determine the effect of these 4 novel carbohydrates and cellulose on apparent ileal (AID) and apparent total tract (ATTD) disappearance, and hindgut disappearance (HGD) of GE, TDF, and nutrients when added to diets fed to ileal-cannulated pigs. The second objective was to measure the endogenous flow of TDF to be able to calculate the standardized ileal disappearance (SID) and standardized total tract (STTD) disappearance of TDF in the 4 novel fibers fed to pigs. Results of the experiment indicated that the AID of GE and DM in diets containing cellulose or the novel fibers was less (P < 0.05) than of the maltodextrin diet, but the ATTD of GE and DM was not different among diets. The addition of RS 60, RS 75, and SCF did not affect the AID of acid hydrolysed ether extract (AEE), CP, or ash, but the addition of cellulose and pullulan reduced (P < 0.01) the AID of CP. The average ileal and total tract endogenous losses of TDF were calculated to be 25.25 and 42.87 g/kg DMI, respectively. The SID of TDF in diets containing RS 60, SCF, and pullulan were greater (P < 0.01) than the SID of TDF in the cellulose diet, but the STTD of the SCF diet was greater (P < 0.05) than for the cellulose and pullulan diets. Results of this experiment indicate that the presence of TDF reduces small intestinal disappearance of total carbohydrates and energy which may reduce the DE and ME of diets and ingredients. Therefore, the objective of Exp. 3 was to determine the DE and ME in yellow dent corn, Nutridense corn, dehulled barley, dehulled oats, polished rice, rye, sorghum, and wheat fed to growing pigs and to determine the AID and ATTD of GE, OM, CP, AEE, starch, total carbohydrates, and TDF in these cereal grains fed to pigs. Results indicated that the AID of GE, OM, and total carbohydrates was greater (P < 0.001) in rice than in all other cereal grains. The AID of starch was also greater (P < 0.001) in rice than in yellow dent corn, dehulled barley, rye, and wheat. The ATTD of GE was greater (P < 0.001) in rice than in yellow dent corn, rye, sorghum, and wheat. With a few exceptions, the AID and ATTD of GE and nutrients in Nutridense corn was not different from the values for dehulled oats. Likewise, with a few exceptions, the AID, ATTD, and HGD of GE, OM, total carbohydrates, and TDF in yellow corn, sorghum, and wheat were not different from each other. The AID of GE and AEE in dehulled barley was greater (P < 0.001) than in rye. The ATTD of GE and most nutrients was greater (P < 0.001) in dehulled barley than in rye. Dehulled oats had the greatest (P < 0.001) ME (kcal/kg DM) whereas rye had the least ME (kcal/kg DM) among the cereal grains. Results of the experiment indicate that the presence of TDF and RS may reduce small intestinal digestibility of starch in cereal grains resulting in reduced DE and ME in these grains. Digestibility experiments involving animals are time consuming and expensive. Therefore, the objective of Exp. 4 was to correlate DM and OM digestibility obtained from 3 in vitro procedures with ATTD of GE and with the concentration of DE in 50 corn samples that were fed to growing pigs. The second objective was to develop a regression model that can predict the ATTD of GE or the concentration of DE in corn. The third objective was to evaluate the suitability of using the DaisyII incubator as an alternative to the traditional water bath when determining in vitro DM and OM digestibility. Results indicated that corn samples incubated with Viscozyme for 48 h in the DaisyII incubator improved (P < 0.001) the ability of the procedure to detect small differences in the ATTD of GE or to detect small differences in the concentration of DE in corn. Likewise, compared with using cellulase or fecal inoculum, the variability in the ATTD of GE and the variability in the DE in corn was better (R2 = 0.56; P < 0.05 and R2 = 0.53; P < 0.06, respectively) explained if Viscozyme was used than if cellulase or fecal inoculum was used. A validated regression model that predicted the DE in corn was developed using Viscozyme and with the corn samples incubated in the DaisyII incubator for a 48 h. In conclusion, this present work used the pig as a model for human gastrointestinal function and evaluates carbohydrates from 2 different nutritional perspectives – humans and animals. The addition of novel carbohydrates reduced the digestibility of energy in the diets without necessarily reducing the digestibility of other nutrients. Thus, supplementation of novel carbohydrates in the diets may be beneficial for the management of diabetes. Aside from diabetic management, cereal grains such as rye and sorghum, may also help in BW management because of there low caloric value, but for undernourished individuals, dehulled oats, dehulled barley, and rice are the ideal grains. From an animal nutrition standpoint, high concentration of dietary fiber is undesirable because it reduces feed efficiency. Therefore, the inclusion of feed ingredients that have a high concentration of dietary fiber is often limited in animal diets. Although in vivo determination is ideal, in vitro procedures are useful tools to determine caloric value of food and feed ingredients.
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It is a fact, and far from being a new one, that students have been entering Higher Education courses with many different backgrounds in terms of secondary school programs they attended. The impact of these basic skills is a general and worldwide challenge, fundamentally when facing some specific “constructive” subjects like foreign languages and Mathematics. Working with students with an extensive variety of Math qualifications is an outrageous challenge when they enter an advanced Math course, leading to an almost generalized expectations’ failure - from students enrolled in course and from their teachers, who feel powerless in trying to monitor knowledge construction from completely different “starting points”. If teachers’ "haste" is average, more than half of the students do not “go along” and give up, even before experiencing any kind of evaluation procedure. On the contrary, if the “speed” is too low, others are discouraged (feeling not progressing at all) and the teacher runs the risk of not meeting the minimum objectives (general and specific) of its course, which may have a negative impact on students’ future training development. Failure in Mathematics, despite being a recurrent and global issue, does not have any “magical solution”, however, in general, teachers in this area seem untiring, searching, investigating, trying and implementing new and old “recipes” to tackle and demystify this subject. In this article we describe a project developed in a Math course, with the first year students from an Accounting and Management bachelor degree, and its outcomes since it was brought to practice, revealing its impact in students’ success, from approval to dropout rates, in this course. We will shortly describe students’ differentiated Math backgrounds, their results in a pre-assessment analysis and how we try to deal with these differences and level them up, having in mind the same “finish line”. One should never forget that all these students where officially accepted in higher education institutions, so they are ones’ reality, the reality of institutions whose name one should value and strive to defend.
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This thesis examines the manufacture, use, exchange (including gift exchange), collecting and commodification of German medals and badges from the early 18th century until the present-day, with particular attention being given to the symbols that were deployed by the National Socialist German Workers’ Party (NSDAP) between 1919 and 1945. It does so by focusing in particular on the construction of value through insignia, and how such badges and their symbolic and monetary value changed over time. In order to achieve this, the thesis adopts a chronological structure, which encompasses the creation of Prussia in 1701, the Napoleonic wars and the increased democratisation of military awards such as the Iron Cross during the Great War. The collapse of the Kaiserreich in 1918 was the major factor that led to the creation of the NSDAP under the eventual strangle-hold of Hitler, a fundamentally racist and anti-Semitic movement that continued the German tradition of awarding and wearing badges. The traditional symbols of Imperial Germany, such as the eagle, were then infused with the swastika, an emblem that was meant to signify anti-Semitism, thus creating a hybrid identity. This combination was then replicated en-masse, and eventually eclipsed all the symbols that had possessed symbolic significance in Germany’s past. After Hitler was appointed Chancellor in 1933, millions of medals and badges were produced in an effort to create a racially based “People’s Community”, but the steel and iron that were required for munitions eventually led to substitute materials being utilised and developed in order to manufacture millions of politically oriented badges. The Second World War unleashed Nazi terror across Europe, and the conscripts and volunteers who took part in this fight for living-space were rewarded with medals that were modelled on those that had been instituted during Imperial times. The colonial conquest and occupation of the East by the Wehrmacht, the Order Police and the Waffen-SS surpassed the brutality of former wars that finally culminated in the Holocaust, and some of these horrific crimes and the perpetrators of them were perversely rewarded with medals and badges. Despite Nazism being thoroughly discredited, many of the Allied soldiers who occupied Germany took part in the age-old practice of obtaining trophies of war, which reconfigured the meaning of Nazi badges as souvenirs, and began the process of their increased commodification on an emerging secondary collectors’ market. In order to analyse the dynamics of this market, a “basket” of badges is examined that enables a discussion of the role that aesthetics, scarcity and authenticity have in determining the price of the artefacts. In summary, this thesis demonstrates how the symbolic, socio-economic and exchange value of German military and political medals and badges has changed substantially over time, provides a stimulus for scholars to conduct research in this under-developed area, and encourages collectors to investigate the artefacts that they collect in a more historically contextualised manner.
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Objective: Our study aimed at assessing the role of flexible bronchoscopy (FB) in improving diagnosis and management of children’s respiratory conditions in the pediatric unit of FB, newly created and unique in Tunisia. Methods: Retrospective study including all the FB achieved in our pediatric unit from 2009 to 2014. Results: We performed 365 FB in 333 patients aged 46 months on average (1 month - 15 years), often under conscious anesthesia (81.6%). FB was performed for diagnostic purposes in 341 cases and for therapeutic purposes in 24 cases. Eight anatomical abnormalities were revealed in 22 patients. An intraluminal bronchial obstruction was found in 71 FB, mainly due to a foreign body (n=36). A vascular anomaly was responsible for nine cases out of 17 extraluminal obstructions. Airways malacia was observed in 60 FB. Bronchoalveolar lavage was performed in 196 cases. It was determinant in 43.9% of the cases. FB was of great diagnostic value in 74.8% of the cases. It influenced the management of the patients in 58% of the cases. The FB for therapeutic purposes was beneficial in all cases. Few complications occurred (5.5%). Conclusion: FB is a safe tool providing precious diagnostic and/or therapeutic help for the clinician. Keywords: