scholarly journals Antarctic Skuas as bioindicators of local and global mercury contamination

2019 ◽  
Vol 5 (3) ◽  
pp. 311-317
Author(s):  
Erli Schneider COSTA ◽  
Maria Mercedes SANTOS ◽  
Nestor Rubem CORIA ◽  
João Paulo Machado TORRES ◽  
Olaf MALM ◽  
...  
Keyword(s):  
Egg Production ◽  
Mercury Contamination ◽  
Migration Patterns ◽  
Non Invasive ◽  
Molting Process ◽  
Low Levels ◽  
Catharacta Maccormicki ◽  
Loss Of Appetite ◽  
The Antarctic ◽  
Erratic Behavior

Mercury (Hg) is a non-essential metal, sometimes extremely toxic, and its presence in the food-web may threaten the wildlife. In seabirds, even low levels of Hg can reduce egg production and the chances of embryos and chicks survival; high levels of this element lead to erratic behavior, loss of appetite and weight, and cellular damages in organs as kidneys can be detected. According to some authors, among 50 to 93% of the total Hg accumulated by the birds through diet can be excreted throughout the feathers during the molting process. In this way, feathers can be used as an excellent non-invasive biomonitor. The objective of this paper was to compared mercury (Hg) levels in feathers of adults and chicks of Catharacta maccormicki(Cma) and C. lonnbergi (Clo) sampled in the Antarctic Peninsula, to identify biomonitors of Hg to the region using non-invasive samples methods. We found Hg significantly higher levels in adults of Cma comparing with Clo adults (U'=841.00, p<0.01) and also with chicks of both species (q>3.398, p<0.01).  We did not find significant differences comparing Clo adults and chicks of both species (U'=16.00, p<0.05), and comparing Cma breeding in different areas (q>3.398, p<0.05) or Clo (U'= 62.00, p < 0.05). The Hg levels variation may be justified mainly by differences in migration patterns. The adults of the species that migrate to more polluted areas (Cma) presented the highest levels of Hg and can be considered a promising indicator of global contamination. In another way, Clo and chicks of both species are good indicators of local Hg contamination, suffering the direct influence of contamination in the Antarctic environment.

Cold tolerance of the Antarctic springtail Gomphiocephalus hodgsoni (Collembola, Hypogastruridae)

2001 ◽  
Vol 13 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Brent J. Sinclair ◽  
Heidi Sjursen
Keyword(s):  
Cold Tolerance ◽  
Thermal Environment ◽  
Strong Relationship ◽  
Dry Weight ◽  
Glycerol Content ◽  
Recrystallization Inhibition ◽  
Low Levels ◽  
Inhibition Studies ◽  
The Antarctic ◽  
The Relationship

Cold tolerance of the springtail Gomphiocephalus hodgsoni Carpenter (Collembola: Hypogastruridae) was studied at Cape Bird, Ross Island, Antarctica (77°13′S, 166°26′E). Microclimate temperatures indicate a highly seasonal thermal environment, with winter minima <–39°C. Snow cover significantly buffers both minimum temperatures and cooling rates. Gomphiocephalus hodgsoni survives low temperatures by avoiding freezing. Mean low group supercooling points (SCPs) ranged from –35.4°C in October to –28.3°C in January. The lowest SCP measured was –38.0°C. The high SCP group was very small, making up only 18% of the population in January. In October, G. hodgsoni had a very high glycerol content (>80 μg mg−1 dry weight), although this declined rapidly to low levels (c. 7–10 μg mg−1 dry weight) in January. Quantities of glucose and trehalose were low during October, but steadily increased throughout the summer. Haemolymph osmolality was exceptionally high (up to 1755 mOsm kg−1) at the end of November, but this rapidly declined to c. 500 mOsm kg−1 by late December. The presence of thermal hystersis proteins was indicated by both osmometry on haemolymph samples and recrystallization inhibition studies of springtail homogenates. There was a strong relationship between glycerol content and SCP, but the relationship between haemolymph osmolality, SCP and carbohydrates is uncertain.

scholarly journals Clinico-radiological profile of abdominal tuberculosis in HIV/AIDS patients-a study from rural central India

2017 ◽  
Vol 5 (5) ◽  
pp. 1980 ◽  
Author(s):  
Nisar A. Wafai ◽  
Sudhir K. Yadav ◽  
Prem S. Singh ◽  
Manoj Kumar ◽  
Prafulla K. Singh ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Central India ◽  
Abdominal Tuberculosis ◽  
Cd4 Count ◽  
Common Finding ◽  
Non Invasive ◽  
Significant Difference ◽  
Average Size ◽  
Loss Of Appetite ◽  
Hiv Aids

Background: One of the major challenge of present era is dual epidemic of HIV/AIDS and tuberculosis. With immunosuppression, risk of opportunistic diseases increases in these patients and tuberculosis is most common opportunistic infection. The prevalence of abdominal tuberculosis seems to be rising, particularly due to increasing prevalence of HIV infection. The diagnosis of abdominal tuberculosis can often be difficult and it remains underdiagnosed, in view of its nonspecific manifestations. The investigations involved in its diagnosis are expensive and time consuming, however, ultrasonography (USG) is an affordable, non-invasive and widely available modality which can be of help in the diagnosis of abdominal tuberculosis. Therefore, this study was undertaken to evaluate clinical and USG finding among Abdominal Tuberculosis patients with HIV/AIDS.Methods: After informed consent, patients underwent thorough history taking and clinical examination followed by high quality USG abdomen and other biochemical and haematological tests including CD4 count. Follow up USG abdomen was done at time of completion of course of ATT and data was analysed.Results: 45 were found to have abdominal tuberculosis. Of these patients, 31(68.9%) were male and 14 (31.1%) were female. Mean age of HIV-abdominal TB was 34.27±9.66 years. most common symptoms were weight loss 41(91.1%), loss of appetite 38(84.4%), fever       32(71.1%), generalized weakness 30(66.7%) and abdominal pain 27(60.0%). On USG abdomen, intraabdominal lymphadenopathy was most common finding found in 44(97.8%). Average size of enlarged lymph node was 3.1+-1.0 cm. Mesenteric lymphnodes were enlarge in 40(88.89%), paraaortic 8(17.78%), retroperitoneal 4(8.89%) while peripancreatic and porta hepatic in 3(6.67%). splenomegaly was noted in 14(31.1%) cases. Hepatomegaly was found in 6 cases, who all were male. Ascites was evident in 5(11.1%) patients. Extensive involvement, defined as involvement of two or more intraabdominal sites, was found 24(53.3%) cases. There was no statistically significant difference found among these USG findings and CD4 count.Conclusions: The findings of lymphadenopathy (size>15mm) and hypoechoic/necrotic echotexture, hepatosplenomegaly with hypoechoic lesions in ultrasonography are suggestive of abdominal tuberculosis in HIV infected patients with unexplained nonspecific symptoms and low CD4 count.  However, above findings are not standardized and inability to confirm the diagnosis of tuberculosis by direct microscopy and culture is the limitation of this study. Ultrasonography is an affordable, widely available, non-invasive imaging modality which may be optimally utilized for the diagnosis of abdominal tuberculosis in HIV infected patients, especially in the rural setup where microbiological and other sophisticated radiological investigations have limited availability.

Mars polar cap: a habitat for elementary life

2009 ◽  
Vol 8 (2) ◽  
pp. 117-119 ◽  
Author(s):  
M.K. Wallis ◽  
J.T. Wickramasinghe ◽  
N.C. Wickramasinghe
Keyword(s):  
Polar Cap ◽  
Low Light ◽  
Microbial Life ◽  
Meteorite Impacts ◽  
Polar Caps ◽  
Light Levels ◽  
Potential Habitats ◽  
Low Levels ◽  
North Polar ◽  
The Antarctic

AbstractIces in the Martian polar caps are potential habitats for various species of microorganisms. Salts in the ice and biological anti-freeze polymers maintain liquid in cracks in the ices far below 0°C, possibly down to the mean 220–240 K. Sub-surface microbial life is shielded from ultraviolet (UV) radiation, but could potentially be activated on south-facing slopes under the midday, midsummer Sun. Such life would be limited by low levels of vapour, little transport of nutrients, low light levels below a protective dirt-crust, frost accumulation at night and in shadows, and little if any active translocation of organisms. As in the Antarctic and in permafrost, movement to new habitats depends on geo-climatic changes, which for Mars's north polar cap occur on a 50 000 year scale, except for rare meteorite impacts.

Influence of Low Levels of Ochratoxin A on Egg Production, Egg-Shell Stains, and Serum Uric-Acid Levels in Leghorn-Type Hens

1980 ◽  
Vol 24 (3) ◽  
pp. 777 ◽  
Author(s):  
R. K. Page ◽  
Greg Stewart ◽  
Roger Wyatt ◽  
Parshall Bush ◽  
O. J. Fletcher ◽  
...  
Keyword(s):  
Uric Acid ◽  
Ochratoxin A ◽  
Serum Uric Acid ◽  
Egg Production ◽  
Low Levels ◽  
Egg Shell

scholarly journals Sea-ice-related halogen enrichment at Law Dome, coastal East Antarctica

2017 ◽  
Vol 13 (2) ◽  
pp. 171-184 ◽  
Author(s):  
Paul Vallelonga ◽  
Niccolo Maffezzoli ◽  
Andrew D. Moy ◽  
Mark A. J. Curran ◽  
Tessa R. Vance ◽  
...  
Keyword(s):  
Sea Ice ◽  
First Year ◽  
Common Source ◽  
Interdecadal Pacific Oscillation ◽  
Austral Spring ◽  
High Accumulation ◽  
Low Levels ◽  
The Law ◽  
Western Side ◽  
The Antarctic

Abstract. The Law Dome site is ideal for the evaluation of sea ice proxies due to its location near to the Antarctic coast, regular and high accumulation throughout the year, an absence of surface melting or remobilization, and minimal multiyear sea ice. We present records of bromine and iodine concentrations and their enrichment beyond seawater compositions and compare these to satellite observations of first-year sea ice area in the 90–130° E sector of the Wilkes coast. Our findings support the results of previous studies of sea ice variability from Law Dome, indicating that Wilkes coast sea ice area is currently at its lowest level since the start of the 20th century. From the Law Dome DSS1213 firn core, 26 years of monthly deposition data indicate that the period of peak bromine enrichment is during austral spring–summer, from November to February. Results from a traverse along the lee (western) side of Law Dome show low levels of sodium and bromine deposition, with the greatest fluxes in the vicinity of the Law Dome summit. Finally, multidecadal variability in iodine enrichment appears well correlated to bromine enrichment, suggesting a common source of variability that may be related to the Interdecadal Pacific Oscillation (IPO).

scholarly journals Sea ice-related halogen enrichment at Law Dome, coastal East Antarctica

2016 ◽  
Author(s):  
Paul Vallelonga ◽  
Niccolo Maffezzoli ◽  
Andrew D. Moy ◽  
Mark A. J. Curran ◽  
Tessa R. Vance ◽  
...  
Keyword(s):  
Sea Ice ◽  
20Th Century ◽  
East Antarctica ◽  
Austral Spring ◽  
High Accumulation ◽  
Low Levels ◽  
The Law ◽  
Western Side ◽  
The Antarctic ◽  
Firn Core

Abstract. The Law Dome site is ideal for the evaluation of sea ice proxies due to its location near to the Antarctic coast, regular and high accumulation throughout the year, an absence of surface melting or remobilization, and minimal multiyear sea ice. We present records of bromine and iodine concentrations and their enrichment beyond seawater compositions, arguing that halogen enrichment is indicative of the local sea ice area, particularly the 90–110° E sector of the Wilkes coast. Our findings support the results of previous studies of sea ice variability from Law Dome, indicating that Wilkes coast sea ice area is currently at its lowest level since the start of the 20th century. From the Law Dome DSS1213 firn core, 26 years of monthly deposition data indicate that the period of peak bromine enrichment is during Austral spring-summer, from November to February. Results from a traverse along the lee (Western) side of Law Dome show low levels of sodium and bromine deposition, with the greatest fluxes in the vicinity of the Law Dome summit. Finally, iodine enrichment is well correlated to that of bromine, indicating a common, sea ice source for their enrichment.

scholarly journals Limitations of PCR detection of filarial DNA in human stools from subjects non-infected with soil-transmitted helminths

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 47
Author(s):  
Maxime P. M. Doret ◽  
Hugues C. Nana-Djeunga ◽  
Narcisse Nzune-Toche ◽  
Sébastien D. S. Pion ◽  
Cédric B. Chesnais ◽  
...  
Keyword(s):  
Central Africa ◽  
Soil Transmitted Helminths ◽  
Non Invasive ◽  
Blood Smears ◽  
Mansonella Perstans ◽  
Stool Samples ◽  
Skin Biopsies ◽  
Low Levels ◽  
Diagnosis Technique ◽  
Standard Techniques

The standard techniques for diagnosis of human filariasis are the microscopic examination of blood smears or skin biopsies, which are relatively invasive and poorly sensitive at low levels of infection. Recently, filarial DNA has been detected in fecal samples from non-human primates in Central Africa. The aim of this study was to demonstrate proof-of-concept of a non-invasive molecular diagnosis technique for human filariasis by targeting fragments of 12S rDNA, Cox1, ITS1 and LL20-15kDa ladder antigen-gene by conventional PCR in DNA extracted from stool samples of 52 people infected with Mansonella perstans and/or Loa loa. Of these, 10 patients were infected with soil-transmitted helminths (Trichuris trichiura and/or Ascaris lumbricoides), and none were positive for Necator americanus. Interestingly, no filarial gene fragments were detected in the stools of any of the 52 patients. Future studies should evaluate whether a co-infection with soil-transmitted helminths causing gastrointestinal bleeding and likely allowing (micro)filaria exit into the digestive tract, may facilitate the molecular detection of filarial DNA fragments in stool samples.

Non-invasive estimation of afferent inputs for postural stability under low levels of alcohol

1987 ◽  
Vol 15 (6) ◽  
pp. 533-550 ◽  
Author(s):  
A. Bhattacharya ◽  
R. Morgan ◽  
R. Shukla ◽  
H. K. Ramakrishanan ◽  
L. Wang
Keyword(s):  
Postural Stability ◽  
Non Invasive ◽  
Afferent Inputs ◽  
Low Levels

Studies on resistance in calves to experimental infections with the nodular worm, Oesophagostomum radiatum (Rudolphi, 1803) Railliet, 1898

1962 ◽  
Vol 13 (3) ◽  
pp. 551 ◽  
Author(s):  
FHS Roberts ◽  
P Elek ◽  
RK Keith
Keyword(s):  
Single Dose ◽  
Egg Production ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
Single Infection ◽  
Fourth Stage ◽  
The Third ◽  
Normal Period ◽  
Low Levels ◽  
Host Parasite

In calves reared free of Oesophagostomum radiatum and given a single infection of this helminth, the third ecdysis in the life cycle was completed in the gut wall in 5-7 days. The fourth stage larva moved into the gut lumen between the seventh md 14th days, where the fourth ecdysis occurred between 17 and 22 days. The prepatent period was 32-42 days. Egg production reached its peak usually during the sixth to 10th weeks, and in most calves this rate of production persisted for only 1-4 weeks. The subsequent decline in the egg count to low levels was very rapid, and was accompanied by the elimination of most of the adult worms. Reinfection with large doses of larvae, either during the period of peak egg production or some weeks later when the egg count was at low levels, did not produce any increase in the egg count, except on rare occasions. In these instances only a small increase was detected. Egg counts of calves given daily doses of larvae showed a trend similar to that resulting from a single dose, and attempts at reinfection with massive doses when the egg count had declined to low levels were also unsuccessful in producing any appreciable rise in the egg count. The failure of the egg count to respond to a challenge dose of larvae is regarded as evidence that a resistance to reinfection had been acquired. Resistance was apparent following a single dose as low as 1000 larvae and a daiIy dose as low as 50 larvae. Necropsies confirmed this conclusion and indicated that, whereas the host resistance mechanism could be responsible for the encapsulation of some reinfecting larvae in the gut tissues and their subsequent death, such mechanism was directed mainly against fourth stage larvae shortly after they had moved back to the gut lumen. The reaction here resulted in the elimination of all or most of the larvae and was accompanied by diarrhoea. While some reinfecting larvae survived in nodules for many weeks in the third or fourth stage, it would seem that the majority of those successfully penetrating the tissues completed the histotrophic phase within the normal period. The few reinfecting larvae which survived to maturity in the gut lumen completed their development also within the normal period. Infection was followed by the production of circulating antibodies detectable by both the haemagglutination and complement fixation tests. With calves infected with a single dose of larvae, all developed haemagglutinins, but complement-fixing (C. F.) antibodies were detected only in some, and these had become infected with Cooperia spp. prior to the experiment. Levels of both types of antibody were low, only exceeding in a few calves a titre of 1/80 for haemagglutinins and of 1/20 for C. F. antibodies. Following reinfection, C. F. antibodies were detected in all animals. They appeared simultaneously with haemagglutinins and there was little evidence that reinfection had stimulated any significant secondary rise in either type of antibody. The available data gave no definite indication of any effect of these antibodies in host-parasite reactions. They suggest, however, that haemagglutinins may be indicative merely of a state of infection, and that C.F. antibodies are stimulated more readily after reinfection.

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