3,699 research outputs found
Assessment of Oxidative Stress in Peste Des Petits Ruminants (Ovine Rinderpest) Affected Goats
The aim of the present investigation was to evaluate oxidative stress in goats affected with peste des petits ruminants (PPR). The experiment was designed to collect blood samples from PPR affected as well as healthy goats during a series of PPR outbreaks which occurred during February to April 2012 in different districts of Rajasthan state (India). Out of total 202 goats of various age groups and of both the sexes, 155 goats were PPR affected and 47 were healthy. Oxidative stress was evaluated by determining various serum biomarkers viz. vitamin A, vitamin C, vitamin E, glutathione, catalase, superoxide dismutase, glutathione reductase and xanthine oxidase, the mean values of which were 1.71±0.09 µmol L-1, 13.02±0.14 µmol L-1, 2.22±0.09 µmol L-1, 3.03±0.07 µmol L-1, 135.12±8.10 kU L-1, 289.13±8.00 kU L-1, 6.11± 0.06 kU L-1 and 98.12±3.12 mU L-1, respectively. Each parameter analysis of variance showed highly significant effect (P=0.0001) of health status and age category. Further interaction between health status and age category was also highly significant (P=0.0001) for each parameter studied. The results indicated that vitamins A, C, E and glutathione levels depressed by 18.95%, 38.67%, 47.64%, and 47.39%, respectively and the serum catalase, superoxide dismutase, glutathione reductase and xanthine oxidase activities increased by 90.79%, 75.11%, 90.34%, and 44.06%, respectively in affected animals as compared to that in healthy ones. On the basis of the altered levels of serum biomarkers of oxidative stress it was concluded that the animals affected with PPR developed oxidative stress
Environmental valuation, ecosystem services and aquatic species
The thesis consists of an introduction and four articles that can be read independently of each other. The common topic is environmental valuation and cost-benefit analysis. The applications relates to the growing concern of invasive species, and to waterpower externalities. In broad terms, all of the articles relates to water management. Article 1: "A Cost-Benefit analysis of introducing a non-native species: the case of signal crayfish in Sweden", assesses the economic impact of introducing the signal crayfish into a Swedish lake. Two scenarios are set up and compared. The first one assumes that there is no introduction of signal crayfish, so that the noble crayfish is preserved. In the second scenario, the signal crayfish is introduced, which immediately wipes out the entire stock of noble crayfish. The values of noble- and signal crayfish populations are measured as present values of their net future revenues. The values are than compared and net benefit of an introduction is calculated. The result indicate that net benefit of an introduction is positive if the intrinsic growth rate or the carrying capacity of the noble crayfish is below 40 % that of the signal crayfish. Article 2: "Assessing management options for weed control with demanders and non-demanders in a choice experiment", estimates the benefits of having a weed management program for a lake in Sweden, and then compares them with corresponding costs. The policy recommendation from a simple cost-benefit rule is to control the weed at some specific sites of the lake. This paper also suggest how to distinguish those that have a positive WTP for at least one of the attributes (demanders) from those that have zero WTP for all attributes (non-demanders). The advantage of the suggested approach is that it facilitates to more clearly distinguish between conditional and unconditional willingness to pay. The suggested approach could also overcome some of the problems in the literature with negative welfare measures. Article 3: "Assessing transfer errors in the benefit transfer method: An application of invasive weed management using choice experiment", tests the accuracy of transferring benefits of a weed management program from one lake to another using choice experiment. The transfer errors are assessed and the convergent validity hypothesis is tested. Estimating the accuracy of benefit transfer for weed management is policy relevant as there are a number of lakes in Sweden infested with the water weed. The convergent validity was rejected for three out of five welfare estimates with a ten per cent significance level. Article 4: "Willingness to pay for environmental improvements in hydropower regulated rivers", assesses the benefits of environmental improvements along hydropower regulated rivers using choice experiments. Remedial measures that improve the conditions for fish, benthic invertebrates and river-margin vegetation were found to have a significant welfare increasing impact. The results can be of value for the implementation of the Water Framework Directives in Sweden, which aims to reform the use of all surface water and ground water in the member states
A Probabilistic Proof of the Multinomial Theorem
In this note, we give an alternate proof of the multinomial theorem using a
probabilistic approach. Although the multinomial theorem is basically a
combinatorial result, our proof may be simpler for a student familiar with only
basic probability concepts.Comment: This is a preprint version. A revised version is available at AMM
websit
The Role of Preferences in Disagreements over Scientific Hypothesis: An Empirical Inquiry into Environmental and Economic Decision Making
The Porter hypothesis suggests that environmental regulations, such as restricting firms to reduce pollution, stimulates innovations and create a win-win situation for the environment and for firms. It has received a great deal of attention from academics as well as bureaucrats who disagree about the applicability of the Porter hypothesis. This study tests if part of such disagreement can be explained by a preference-expectation relationship and if people are more likely to believe in a scientific hypothesis that appeals to their preferences. The results show that individuals' who care more about the environment are more likely to believe in the Porter hypothesis. We also discuss the capacity of economic methodology to mitigate a preference-expectation bias and how it relates to the current practice in environmental economics.Porter Hypothesis, Subjective Beliefs, Economic Methodology
Detectability of Exoplanets in the Beta Pic Moving Group with the Gemini Planet Imager
We model the detectability of exoplanets around stars in the Beta Pic Moving
Group (BPMG) using the Gemini Planet Imager (GPI), a coronagraphic instrument
designed to detect companions by imaging. Members of the BPMG are considered
promising targets for exoplanet searches because of their youth (~12 MY) and
proximity (median distance ~35 pc). We wrote a modeling procedure to generate
hypothetical companions of given mass, age, eccentricity, and semi-major axis,
and place them around BPMG members that fall within the V-band range of the
GPI. We count as possible detections companions lying within the GPI's field of
view and H-band fluxes that have a host-companion flux ratio placing them
within its sensitivity. The fraction of companions that could be detected
depends on their brightness at 12 Myr, and hence formation mechanism, and on
their distribution of semi-major axes. We used brightness models for formation
by disk instability and core-accretion. We considered the two extreme cases of
the semi-major axis distribution - the log-normal distribution of the nearby F
and G type stars and a power-law distribution indicated by the exoplanets
detected by the radial velocity technique. We find that the GPI could detect
exoplanets of all the F and G spectral type stars in the BPMG sample with a
probability that depends on the brightness model and semi-major axis
distribution. At spectral type K to M1, exoplanet detectability depends on
brightness and hence distance of the host star. GPI will be able to detect the
companions of M stars later than M1 only if they are closer than 10 pc. Of the
four A stars in BPMG sample, only one has V-band brightness in the range of
GPI; the others are too bright.Comment: Accepted for publication in the Astronomical Journa
Opterećenje tekućinom i prijenosna sposobnost bubrega u dvogrbe deve u dehidraciji i rehidraciji zimi i ljeti
The effect of dehydration and rehydration was studied during winter and summer on solute loads and transfer function of kidney in healthy adult female dromedary camels. Kidney solute loads (KSLs) which included plasma loads (PL) and tubular loads (TL) were determined for glucose, proteins, urea, creatinine, sodium, potassium, chloride, calcium and phosphorus. The dehydration period was of 24 days in winter and 13 days in summer. Water was provided ad libitum during control and rehydration periods and was restricted
completely during dehydration period. The mean value of TFK during summer control was significantly (P≤0.05) lower than that in winter control. In winter the mean values of TFK during rehydration phases differed significantly (P≤0.05) from control values. A similar trend was observed during summer, except that the calculations for TFK could not be made at hour ½ and at hour 2 of rehydration since animals did not void urine. During dehydration periods in both seasons PL and TL mean values decreased significantly (P≤0.05) from respective control mean values. It was concluded that during dehydration reduction in kidney solute loads was indicative of the water conservation ability of camels because reduced plasma loads and tubular loads resulted in trapping of constituents in the plasma to hold more water.Istražen je učinak dehidracije i rehidracije u tijeku zime i ljeta na opterećenje tekućinom i prijenosnu sposobnost bubrega u zdravih ženki dvogrbe deve. Opterećenje obuhvaća plazmalno (PO) i tubularno (TO) opterećenje, a određivano je za glukozu, bjelančevine, mokraćevinu, kreatinin, natrij, kalij, klor, kalcij i fosfor. Razdoblje dehidracije trajalo je 24 dana zimi i 13 dana ljeti. Životinje su po volji pile vodu tijekom kontrolnoga i rehidracijskoga razdoblja, ali vodu nisu dobivale u tijeku dehidracijskoga razdoblja. Srednja vrijednost
prijenosne sposobnosti bubrega u tijeku ljetnih mjeseci bila je značajno niža (P≤0,05) u odnosu na zimsko kontrolno razdoblje. Zimi su se srednje vrijednosti prijenosne sposobnosti bubrega za vrijeme rehidracije značajno razlikovale u odnosu na kontrolne vrijednosti (P≤0,05). Sličan je trend zabilježen ljeti, osim što izračuni nisu mogli biti učinjeni sat i pol te dva sata nakon rehidracije, jer životinje nisu izlučivale mokraću. Srednje vrijednosti PO i TO bile su značajno manje u odnosu na kontrolu (P≤0,05) u tijeku dehidracijskoga razdoblja u oba godišnja doba. Zaključuje se da je smanjeno opterećenje bubrega u tijeku dehidracije dobar pokazatelj sposobnosti čuvanja vode s obzirom na to da smanjeno plazmalno i tubularno opterećenje dovodi do zadržavanja sastojaka u plazmi koji imaju sposobnost osmotskoga zadržavanja vode
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