1,958 research outputs found
Permitted Unless Prohibited: The Changed Soviet Mentality
Even more basic than the presence of an abundance of experts and specialists, however, is the need for an amorphous intangible, the will to achieve and succeed. The will of a nation, an admittedly nebulous and vague idea, ideally is discerned, expressed, and exercised by its leaders in the government and in the legislature. It is up to these leaders to want and then to initiate, adopt, and implement the rule of law, a term which itself embodies many concepts but contains no therapeutic formulas. In this regard, the darling of the International Monetary Fund (“IMF”), the small nation of Estonia, with a population comparable to that of the island of Manhattan, had the political and intellectual leadership with the will and the drive to create a market economy embedded in the rule of law. How such a will arises or is created is the subject for a separate sociological study and not a topic for this Essay. But the positive consequences of the leadership of Estonia in exercising and implementing this national will stands not so much as a challenge to other nations still struggling with the transformation process, such as many of the member countries of the Commonwealth of Independent States (“CIS”), but as an example and a confirmation that a successful transition from a centrally planned economy to a free market economy can be achieved quickly. To simply attribute and dismiss Estonia\u27s emergence as an anomaly due to the difference of its culture from that of the other peoples in the former Soviet Union, however, as is commonly done by many academicians, legislators, and other leaders in the nations of the CIS, is simply a self-fulfilling excuse for inaction, inevitable failure, and cultural arrogance, even if masked as a compliment. In fact, the prospective, still unheralded, success of the Republic of Georgia in its law reform efforts belies any such assertions. It is of note that the remarkable emergence of Estonia, and the expected achievements of Georgia, did not develop in a vacuum, but utilized the support of the international community to buttress national will
Lung function decline in 4-monthly repeated spirometric measurements: Due to silt aerosol exposure or decreasing effort?
Background: Workers on dredgers and lighters on rivers are exposed to the inhalation of aerosols and dusts. Objective: The aim of this study was to investigate effects of river silt aerosol and dust exposure on the respiratory health of dredging employees. Methods: Six era mi nations were performed over a period of 2 years at 4-monthly intervals in 54 seamen with higher silt aerosol exposure and 36 controls of the same employer. Results: No significant differences could be observed between the groups at any time of the study but there was an unexpected significant decrease in the age-corrected expiratory vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and midexpiratory flow rate (MMEF25/75) over the six series in both groups. This may indicate a loss of effort of the participants in re-examinations since biological and technical influences were highly unlikely to be the cause of these findings. Conclusions: Ignoring this possible decline of effort in frequently repeated measurements may result in overestimating potential effects of occupational exposure. Copyright (C) 2000 S. Karger AG, Basel
Tribal Jurisdiction and Domestic Violence: The Need for Non-Indian Accountability on the Reservation
Domestic violence is a severe problem for tribes across the nation, as their female members are victimized at highly disproportionate rates compared to members of dominant society. Many tribes have sophisticated domestic violence codes to combat the problem, but they are powerless to prosecute the majority of those who will abuse Indian women: non-Indian men. In 1978 the Supreme Court stripped tribes of their power to prosecute non-Indians in criminal matters, which not only damaged tribal sovereignty but also meant the difference between a life free from abuse and one with constant fear, intimidation, and pain for Indian women.
The federal government has, since that time, had almost exclusive jurisdiction\u27 over non-Indians who commit crimes on the reservation. Federal prosecutors with heavy workloads and limited resources often plead out cases of domestic violence to far lesser crimes or decline to prosecute these offenses at all. Tribes that have the resources and commitment to stop violence against Indian women are forbidden to take action against non-Indian offenders. This lack of accountability on the part of dominant society must stop immediately, and tribes must have the power to prosecute these non-Indian offenders to provide the protection these women deserve.
This Note argues that Congress should restore tribal jurisdiction over non-Indian criminal offenders. The primary purpose of restoring tribal jurisdiction is to protect Indian women from abuse by repeat offenders, and ensure these women receive the justice they deserve. Allowing tribes to assert jurisdiction over nonIndian offenders will also show that the federal government has not forgotten the sovereign status of Indian nations, established almost 200 years ago. As sovereign nations, tribes should be permitted to enforce laws covering their territory and ensure justice for their members by responding to the unique problems facing American Indians. Tribal jurisdiction over non-Indians is essential to accomplishing these goals and must be restored by Congress at once
Kinetic of vitamin A resorption in blood plasma and vitamin A excretion in urine of dogs
Deckblatt-Impressum
Inhaltsverzeichnis
AbkĂĽrzungsverzeichnis
Einleitung und Problemstellung
LiteraturĂĽbersicht
Material und Methoden
Ergebnisse
Diskussion
Zusammenfassung
Summary
Literaturverzeichnis
Anhang
Danksagung
SelbständigkeitserklärungHunde und andere Carnivoren transportieren im Gegensatz zum Menschen und den
meisten anderen Tierarten Vitamin A im Blut nicht nur in Form von Retinol,
sondern vorwiegend als an lipoproteingebundene Retinylester. Diese
unspezifisch gebundenen Vitamin-A-Ester treten bei Mensch und Ratte nur bei
einer Vitamin-A-Ăśberversorgung auf und werden fĂĽr die Symptome einer
Vitamin-A-Intoxikation verantwortlich gemacht, da die regulierende Wirkung und
homöostatische Kontrolle von RBP entfällt. Carnivoren, besonders Caniden und
Musteliden, besitzen, bedingt durch den hohen Anteil an Vitamin-A-Estern, um
ein Vielfaches höhere Vitamin-A-Konzentrationen im Blut als zum Beispiel
Menschen, Nager und Herbivoren. Anzeichen einer Vitamin-A-Intoxikation werden
dabei nicht gesehen. Möglicherweise deshalb nicht, weil Caniden in der Lage
sind, Vitamin A in Form von Retinol und Retinylestern mit dem Harn
auszuscheiden. Als Vitamin-A-Trägerprotein konnte das Tamm-Horsfall-Protein
identifiziert werden. Da aber auch andere Carnivoren, wie Feliden und
Musteliden, die Vitamin A nicht bzw. individuell verschieden geringer ĂĽber den
Harn eleminieren, hohe Retinylester-Konzentrationen im Blut haben, mĂĽssen noch
andere Regulationsmechanismen existieren. Ziel der vorliegenden Studie war es
zu klären, ob eine einmalige orale Gabe von Vitamin A einen Einfluß auf die
Vitamin-A-Konzentration im Blut und im Harn besitzt. Dabei sollte der
Zusammenhang zwischen der Vitamin-A-Resorption im Darm, der Anflutung von
Vitamin A im Blutplasma und die Ausscheidung von Vitamin A mit dem Harn
erforscht werden. Dazu wurde von acht Hunden der Rasse Beagle 48 Stunden vor
und ab eine Stunde bis 96 Stunden nach einer einmaligen Vitamin-A-Gabe Blut
abgenommen sowie Harn gesammelt. Die Vitamin-A-Gabe erfolgte nach 16-stĂĽndigem
Fasten als Bolus von 10.000 IE Vitamin A/kg Körpergewicht (3000 RE/ kg
Körpergewicht) in Form von Retinylpalmitat (URSOVIT® A, wässrig, Serumwerk
Bernburg AG, Deutschland) zusammen mit fĂĽnf ml Sahne (30% Fettanteil) mittels
Spritze direkt in den hinteren Maulbereich. Die Chylomikronen-Separierung und
die Isolierung der Lipoproteine erfolgte durch Ultrazentrifugation. Die
qualitative und quantitative Bestimmung von Vitamin A im Blutplasma und im
Harn erfolgt nach organischer Extraktion durch Hochdruck-FlĂĽssigkeits-
Chromatographie (HPLC). Der RBP-Nachweis (Blutplasma und Harn) wurde nach
elektrophoretischer Trennung im Western Blot durchgefĂĽhrt. AuĂźerdem fand fĂĽr
die quantitative Bestimmung von RBP und THP im Blutplasma und Harn die ELISA-
Methode Anwendung. Die Bestimmung von Triglyceriden und Cholesterol im
Blutplasma und in den Lipoproteinfraktionen erfolgte mit Hilfe enzymatischer
Testverfahren. Im Blut und Harn aller Hunde konnte in Ăśbereinstimmung mit
vorherigen Untersuchungen Vitamin A sowohl als Retinol, als auch als
Retinylester nachgewiesen werden. Nach Vitamin-A-Gabe steigen die Werte fĂĽr
die Retinylester bis acht Stunden nach Vitamin-A-Gabe an, die Werte fĂĽr
Retinol bis sechs Stunden nach Vitamin-A-Gabe. Danach fallen sowohl die
Retinolwerte, als auch die Gesamtretinylesterwerte wieder bis auf Höhe der
Ausgangswerte. Dieser Anstieg des Vitamin A ist besonders durch den Anstieg
von Retinylpalmitat bedingt. Neuabsorbiertes oral aufgenommenes Vitamin A im
Blutplasma scheint besonders als Retinylpalmitat transportiert zu werden. Das
Maximum der Retinylesterkonzentration in den Chylomikronen liegt innerhalb der
ersten Stunde nach Vitamin-A-Aufnahme. Dabei ist der prozentuale Anteil von
Retinylpalmitat und Retinylstearat in den Chylomikronen ähnlich hoch und
unterliegt im Untersuchungszeitraum keiner signifikanten Veränderung. Alle
drei Retinylester nehmen im Serum und Chylomikronenunterstand bis acht Stunden
nach Vitamin-A-Gabe zu, während der Gehalt in den Chylomikronen abfallend ist.
Da die Retinylesterwerte im Chylomikronenunterstand sich, im Gegensatz zu den
Chylomikronen, ähnlich wie die Retinylesterwerte und Triglyceridwerte im Blut
verhalten, muss zukünftig geklärt werden, ob sich im Chylomikronenunterstand
Hinweise auf einen anderen Transportmechanismus fĂĽr Retinylester als den
lipoproteingebundenen finden lassen. Es konnte bestätigt werden, dass RBP nur
im Blutplasma, jedoch nicht im Harn auftritt. Die Werte fĂĽr RBP sanken nach
Vitamin-A-Gabe und verliefen somit nicht parallel zu den Retinol-
Konzentrationen im Serum. Die Retinylester wurden im Blutplasma in allen drei
Lipoproteinfraktionen nachgewiesen. Damit konnten vorherige Untersuchungen
bestätigt werden. Retinylstearat bildet ca. 55 bis 65%, Retinylpalmitat ca. 25
bis 30% und Retinyloleat ca. 10%. Die Retinylester wurden besonders in der
LDL-Fraktion, gefolgt von der VLDL-Fraktion, nachgewiesen. In der LDL-Fraktion
trat das Maximum nach acht Stunden, in der VLDL-Fraktion nach 24 Stunden auf.
Nach Vitamin-A-Gabe konnte konnte nur bei fĂĽnf von acht Hunden eine vermehrte
Vitamin-A-Ausscheidung ĂĽber den Harn festgestellt werden. Allerdings
unterscheiden sich diese Tiere der response -Gruppe erheblich in der Art und
Weise der Vitamin-A-Auscheidung. Das Trägerprotein von Vitamin A im Harn ist
das THP. Die THP-Konzentration steigt bis acht Stunden nach Vitamin-A-Gabe
stark an und fällt dann bis zum Ende der Messungen nach 96 Stunden bis unter
die Hälfte des Ausgangswertes ab. Ein signifikanter Zusammenhang zwischen der
Vitamin-A- und THP-Auscheidung im Harn konnte nicht festgestellt werden.
AbschlieĂźend kann festgestellt werden, dass eine einmalige hohe Gabe an
Vitamin A an gesunde Hunde sich auf die Retinol- und Retinylester-
Konzentration im Blut auswirkt. Obwohl die Hälfte der untersuchten Hunde nach
Vitamin-A-Gabe vermehrt Vitamin A ĂĽber den Harn ausschieden, konnte ein
direkter Einfluss der Vitamin-A-Gabe auf den Vitamin-A-Gehalt im Urin nicht
nachgewiesen werden. Sowohl der genaue Mechanismus der Vitamin A-Ausscheidung
als auch die sich daraus ergebenden Konsequenzen fĂĽr die Vitamin-A-Aufnahme
und fĂĽr den Vitamin-A-Metabolismus bei Carnivoren erfordern weitere Studien
und Untersuchungen.Dogs and other species of the order Carnivora transport vitamin A in blood
plasma not only as retinol but predominantly as lipoprotein bound retinyl
esters. In humans and rats lipoprotein bound retinyl esters are only observed
postprandial or as a consequence of an excessive vitamin A intake leading to
severe signs of hypervitaminosis A. In contrast, the occurrence of retinyl
esters in the blood plasma of canines is not associated with any sign of
vitamin A intoxication possibly by the excretion from retinol and retinyl
esters, which are bound to Tamm-Horsfall protein (THP) in the urine. But there
are possible different mechanisms in the regulation of urinary vitamin A
excretion, because other carnivores like felides or mustelides, that also
share a high concentration of retinyl ester in the blood plasma, do excrete no
or low levels of vitamin A with their urine. Therefore, the present study was
performed to investigate the effect of a single oral dose of vitamin A on the
vitamin A concentration in blood plasma and their subsequent excretion in
urine of dogs. We also examined general aspects of the vitamin A metabolism in
order to provide more insight into the peculiarities of vitamin A metabolism
in dogs. Eight male beagle dogs were given a single oral dosage of vitamin A
of 3000 retinyl equivalents (RE) / kg body weight (BW) after a 16 hours
overnight fast. The vitamin A supplement was administered through a syringe
directly in the back of the mouth in form of retinyl palmitate (Ursovit® A,
Bernburg, Germany) together with 5 ml cream (30% fat). Blood was sampled at 48
hours before and 1, 2, 3, 4, 6, 8, 24, 48, 72 and 96 hours after dosing. Urine
samples were collected for 18 hours each day into individual bottles beneath
metabolic cages until 96 hours after dosing. Plasma was separated by
centrifugation. Chylomicrons and plasma lipoproteins were separated by
preparative ultracentrifugation. Retinol and retinyl esters in plasma and
urine were qualitatively and quantitatively examined after organic extraction
by a gradient-HPLC method. RBP in plasma and urine was detected by Western
blotting after protein separation on SDS-PAGE. The quantitative determination
of RBP and THP in blood plasma and urine was performed by ELISA systems.
Triglyceride and cholesterol concentrations in blood plasma and in lipoprotein
fractions were examined using commercial test kits. Consistent with the
results of earlier studies, the predominant vitamin A metabolites in the
plasma of fasting dogs were retinol and retinyl esters. After administration
of 3000 RE/kg BW, plasma levels of retinol and retinyl esters increased and
reached their highest values 6 hours and 8 hours after dosing, respectively.
The ratio between plasma retinyl stearate and retinyl palmitate declined
significantly indicating that newly absorbed dietary vitamin A seems to be
transported primarily as retinyl palmitate in the plasma of dogs. The maximum
of chylomicron retinyl esters peaked already within 1 hour after vitamin A
supplementation. The percentage of retinyl palmitate and retinyl stearate
associated with chylomicrons was similarly high and there were no significant
effects during the time of investigation. The concentration of all three
retinyl esters in blood plasma as well as in chylomicron infranatant increased
until 8 hours after vitamin A dosing, whereas their corresponding values in
the chylomicron fraction decreased. Because of similar percentages of retinyl
esters in plasma and chylomicron infranatant, additional studies are needed to
clarify possible different transport mechanisms in the postprandial vitamin A
response of dogs. Retinol-binding protein (RBP) was present in plasma, but
never in urine. In plasma, the postprandial concentrations of RBP decreased
after vitamin A dosing and did not parallel the concentration of retinol. In
confirmation to previous investigations, plasma retinyl ester were present in
all three lipoprotein fractions. In fasted dogs, retinyl stearate (55-65%) was
the predominant ester of vitamin A followed by retinyl palmitate (25-30%) and
retinyl oleate (10%). The retinyl esters were predominantly detected in the
low density lipoprotein (LDL) and very low density lipoprotein (VLDL)
fraction. The maximum of retinyl esters appeared in the LDL fraction after 8
hours, in the VLDL fraction after 24 hours. After the oral intake of 3000
RE/kg BW only 4 out of 8 dogs showed an elevation of their vitamin A
concentration in urine. But the excretion of vitamin A in the response group
was quite variable. The carrier protein for fat soluble vitamin A in urine is
THP. Until 8 hours after dosing, the THP concentration significantly increased
and declined continuously at 96 hours to concentrations half of baseline
values. Moreover, the results indicate that urinary THP excretion has no
significant correlation to urinary vitamin A excretion. In conclusion, the
study shows that a large single oral administration of 3000 RE/kg BW in
healthy dogs increases the retinol and the retinyl ester concentrations in
plasma. Although half of the investigated dogs excrete vitamin A in the urine
above their baseline levels, a directly affection of dietary vitamin A on the
urine vitamin A excretion of dogs is questionable. More knowledge of the THP
carrier on the cellular and molecular level would be helpful to elucidate the
signals and mechanisms that are responsible for the excretion of VA in the
urine of dogs
Optimisation of a Hybrid Wall for Solar Utilisation in Agriculture
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a Technical article from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 2 (2000): J. Radon, W. Bieda. Optimisation of a Hybrid Wall for Solar Utilisation in Agriculture
Utilizing the Concept of Convenience as a Business Opportunity in Emerging Markets
Non-store retailing is dominated by the Internet and is a potential strategy for manufacturers, brand owners, and retailers entering emerging markets. Consumers in developed markets shop online for a variety of retail goods, and motives for choosing e-commerce are often referred to as convenience reason. Convenience is essential for understanding why consumers prefer one channel to another. By revisiting the concept of convenience as a significant variable in e-commerce and exploring its complexity and the multiple meanings of the concept with regard to emerging markets, the paper considers a business opportunity in terms of new ways of reaching emerging markets and proposes potential lines for future research with regard to this concept
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