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PubMedDate not supplied

[Search for life on Mars].

The paper presents the data about the catalytic activity of several minerals from the Martian ground and of some laboratory analogues of the planet ground. It has been shown that it is possible to obtain unambigious data about life on Mars by using such methodological approaches which are based on biological principles of the determination of living matter. Microbiological methods for detection of extraterrestrial life should be preferred in future over biogeochemical methods which were used by the Viking stations.

Carbon Dioxide↗
PubMed1977

Report of a case of true hermaphroditism with karyotype 45,X/46,XX/46,X,mar/47,XX,mar.

The case of a 24-year-old man with hypoplastic external genitalia, lack of the right scrotal testis and gynaecomastia has been described. In the intermitotic cells the cytogenetic investigations revealed the presence of the X body and the absence of the Y body. A 45,X/46,XX/46,X,mar/47,XX,mar karyotype could be established. On laparotomy a rudimentary ovary, uterus and vagina were detected on the right side of the abdominal cavity.

Adult↗
PubMedDate not supplied

[Survival of bacteria in the Artificial Mars unit].

The survival of bacteria was studied in the "Artificial Mars" apparatus reproducing a complex of physical extreme factors. Bacteria isolated from microbiocenoses subjected to the action of chemical extreme factors (hydrogen peroxide, catalytically active minerals) were shown to be most resistant among soil heterotrophic bacteria. Cells in the resting state caused by dehydration survived better than vegetative cells. It has been concluded that microorganisms quite different in their physiological requirements and ecological properties can exist in the habitats extreme for life conditions.

Atmosphere Exposure Chambers↗
PubMed1980

[46,XX,r(18), + mar karyotype in the niece of a leukemic patient with trisomy 21 and cri du chat chromosome (author's transl)].

The present observation concerns a female patient with a 47,XX, r(18), + mar karyotype. The size of the ring varies from mitosis to mitosis; generally it is very small. The presence of a small marker ("minute") may explain some phenotypic differences not usually observed in the "r(18) syndrome". This patient is the niece of a trisomic 21, who showed complex chromosome anomalies during the course of an acute leukemia from which he died.

Child, Preschool↗
PubMed1981

Evaluation of the Del Mar Avionics automatic ambulatory blood pressure-recording device.

We have the opportunity to evaluate a portable ambulatory device for the recording of sequential indirect arterial blood pressure and continuous electrocardiogram (Del Mar Avionics automatic ambulatory blood pressure recording device). With careful attention to technique, only 11% of systolic and 5% of diastolic blood pressure readings differed by more than 10 mm Hg as compared with a trained technician's observations simultaneously in the same arm. The device has been useful in the evaluation of borderline (labile) hypertension, hypertensive drug therapy programs, and various episodic cardiovascular phenomena--for example, vasodepressor syncope and pheochromocytoma crises.

Adult↗
PubMedDate not supplied

[Numerical taxonomy of staphylococci isolated from water and beach sand from Valparaíso and viña del Mar, Chile].

A total of 85 strains of Gram positive cocci isolated from beach water and sand located in Valparaiso bay, and Viña del Mar, Chile, were examined for 59 morphological, physiological and biochemical characteristics. The taxonomic data were analysed by numerical taxonomy using Ssm coefficient and the Unweighted Pair Group Method of Association (UPGMA). At 80% similarity level, four phenons were obtained. Of the 85 strains 31% were classified as Staphylococcus epidermidis, 9% were classified as Staphylococcus haemolyticus, 36% were classified as Staphylococcus spp. and 24% as Staphylococcus aureus. Epidemiological considerations are made in relation with the probable impact that the isolation of Staphylococcus aureus and coagulase negative Staphylococci would have on the health of the population.

Chile↗
PubMed1994

Gonadal mixed germ cell tumor combined with a large hemangiomatous lesion in a patient with Turner's syndrome and 45,X/46,X, +mar karyotype.

In this report, we describe bilateral gonadal tumors with characteristic histopathological findings in a patient with Turner's syndrome who had 45,X/46,X, +mar mosaicism. The left gonad contained a gonadoblastoma and a remnant of streak gonad. The right gonad was entirely replaced by a 15x11x7-cm solid and cystic tumor, which was revealed to be a combination of a mixed germ cell tumor and a cavernous hemangiomatous lesion. The latter occupied approximately half of the entire tumor volume, and there was an incomplete boundary between it and the mixed germ cell tumor lesion. To our knowledge, this is the first reported case of Turner's syndrome with a combination of a mixed germ cell tumor and a hemangiomatous lesion in the gonad.

Adolescent↗
PubMedDate not supplied

[Isolation of V. cholerae no-01 and V. metschnikovii from sewage of the city of Mar del Plata].

A total of 42 vibrio strains isolated from sewage, together with 7 culture collection strains were studied by numerical taxonomy. A simplified clustering is shown in Fig. 1. Two important phena were determined. Phenon 1, identified as V. cholerae non-01, formed at 0.90% S, contains 32 sewage strains and 2 reference strains. Phenon 2, identified as V. metschnikovii, formed at 0.85% S, contains 5 sewage strains. No typical marine vibrio species were isolated. The phenotypic characteristics of 2 phena are shown in Table 2. All V. cholerae non-01 were haemolytic, proteolytic and lipolytic. They also showed some phenotypic characteristics (degradation of esculin, 81.2%; utilization of: D-glucuronate, 88.2%; cellobiose, 47.0% and lactose, 47.0%), and growth in NaCl 6%, 91.1%. According to literature references, the survival of V. cholerae non-01 in Mar del Plata marine environment is possible.

Argentina↗
PubMed1997

Description of a new species of Maritrema (Digenea:Microphallidae) from Mar Chiquita coastal lagoon (Buenos Aires, Argentina) with notes on its life cycle.

Adults of Maritrema bonaerensis n. sp. (Digenea:Microphallidae) were collected from the intestine of the gulls Larus maculipennis and Larus atlanticus from Mar Chiquita coastal lagoon, Buenos Aires province, Argentina. The new species differs from M. pulcherrima Travassos, 1928 in having smaller sucker ratio, longer intestinal ceca, ovary not lobed, and larger eggs, and from Maritrema prosthometra Deblock and Heard, 1969 it differs in having larger suckers, smaller vitelline follicles, and in the absence of pars prostatica. It differs from Maritrema acadiae (Swales, 1933) in having larger body and pharynx and longer cirrus. It differs from Maritrema paracadiae Ching, 1974 in the larger pharynx, longer cirrus, and in the absence of prominent prostatic cells. From Maritrema majestova Ke, 1976, it differs in having a larger body, smaller eggs, and a long and protusible cirrus. Finally, M. bonaerensis differs from Maritrema chiricae Deblock, 1975 in the larger body, longer cirrus, and in the morphology of the seminal vesicle. Sporocysts and metacercarial stages isolated from the snail Heleobia australis australis and from the crabs Cyrtograpsus angulatus and Chasmagnatus granulata, respectively, suggest that those invertebrates could act as intermediate host in the life cycle of the new species in the lagoon. This assumption is supported by evidence derived from natural and experimental infections, from studies on biology of the actual and presumed hosts, as well as from previous reports on life cycles of species of Maritrema with similar transmission patterns.

Animals↗
PubMedDate not supplied

[Bovine leukemia virus (BLV): prevalence in the Cuenca Lechera Mar y Sierras from 1994 to 1995].

The Cuenca Lechera Mar y Sierras (CLMS) includes about 300 dairy farms located in the counties of Tandil, Balcarce, Juarez, Ayacucho, General Pueyrredón, Gonzalez Chavez and Necochea, in the province of Buenos Aires. The purpose of this investigation was to determine the prevalence of infection caused by Bovine Leukemia Virus (BLV) in the CLMS. We investigated the presence of anti-BLV antibodies in 4,203 milk samples taken from 73 dairy farms belonging to the CLMS. An indirect ELISA, which is described and evaluated in this paper, was used to test the antibodies in milk. We classified the dairy farms according to their rate of infection. The percentage of dairy farms free of infection resulted in 31.50. On the other hand, 49.40% of the dairy farms showed a figure between 1% and 15% of infected cattle; 17.80% between 16% and 30%, and the remaining 1.30% turned out more than 30% of infected cattle. If compared with data obtained in the 1979-1981 period, which showed that 95.65% of the dairy farms was BLV-free, it is clear that a dramatic progress of the BLV infection has occurred for the last 15 years. Nevertheless, the CLMS is in a privileged position so as to incorporate an inexpensive control plan to eradicate the BLV infection, as almost 1/3 of its dairy farms is still BLV-free and 49.40% still has a low rate of BLV infection. Only about 20% of the dairy farms would require costly strategies of control.

Animals↗
PubMed1997

[VI Ibero-American Summit of heads of state and government: Declaration of Viña del Mar].

The leaders of 21 Ibero-American countries came to Viña del Mar (Chile) for the sixth meeting of the now-traditional Ibero-American Summits. The Declaration that resulted from the Summit reiterated the commitment of these nations to the principles of democracy, the rule of law, and political pluralism. The development of efficient and participatory systems of democratic government was one of the most important of the topics dealt with at the meeting and served as the framework for the discussion and the search for solutions to common problems, such as poverty, arms trafficking, unequal opportunity for men and women, and inappropriate government practices. The leaders also supported a series of initiatives and international programs in the technological and cultural arenas that will strengthen the ties and unite the Spanish- and Portuguese-speaking countries.

Chile↗
PubMed1997

Episodic ocean-induced CO2 greenhouse on Mars: implications for fluvial valley formation.

Pulses of CO2 injected into the martian atmosphere more recently than 4 Ga can place the atmosphere into a stable, higher pressure, warmer greenhouse state. One to two bar pulses of CO2 added to the atmosphere during the past several billion years are sufficient to raise global mean temperatures above 240 or 250 K for tens to hundreds of millions of years, even when accounting for CO2 condensation. Over time, the added CO2 is lost to carbonates, the atmosphere collapses and returns to its buffered state. A substantial amount of water could be transported during the greenhouse periods from the surface of a frozen body of water created by outflow channel discharges to higher elevations, despite global temperatures well below freezing. This water, precipitated as snow, could ultimately form fluvial valleys if deposition sites are associated with localized heat sources, such as magmatic intrusions or volcanoes. Thus, if outflow channel discharges were accompanied by the release of sufficient quantities of CO2, a limited hydrological cycle could have resulted that would have been capable of producing geomorphic change sufficient for fluvial erosion and valley formation. Glacial or periglacial landforms would also be a consequence of such a mechanism.

Atmosphere↗
PubMed1996

Reflectance spectroscopy and geochemical analyses of Lake Hoare sediments, Antarctica: implications for remote sensing of the Earth and Mars.

Visible to infrared reflectance spectroscopic analyses (0.3-25 micromoles) have been performed on sediments from the Dry Valleys region of Antarctica. Sample characterization for these sediments includes extensive geochemical analyses and X-ray diffraction (XRD). The reflectance spectra and XRD indicate major amounts of quartz, feldspar, and pyroxene in these samples and lesser amounts of carbonate, mica, chlorite, amphibole, illite, smectite, and organic matter. Calcite is the primary form of carbonate present in these Lake Hoare sediments based on the elemental abundances and spectroscopic features. The particle size distribution of the major and secondary components influences their detection in mixtures and this sensitivity to particle size is manifested differently in the "volume scattering" and "surface scattering" infrared regions. The Christiansen feature lies between these two spectral regimes and is influenced by the spectral properties of both regions. For these mixtures the Christiansen feature was found to be dependent on physical parameters, such as particle size and sample texture, as well as the mineralogy. Semiquantitative spectroscopic detection of calcite and organic material has been tested in these quartz- and feldspar-rich sediments. The relative spectral band depths due to organics and calcite correlate in general with the wt% C from organic matter and carbonate. The amounts of organic matter and carbonate present correlate with high Br and U abundances and high Ca and Sr abundances, respectively. Variation in the elemental abundances was overall minimal, which is consistent with a common sedimentary origin for the forty-two samples studied here from Lake Hoare.

Antarctic Regions↗
PubMed1996

Water erosion on Mars and its biologic implications.

The Martian surface shows abundant evidence of water erosion. Liquid water is unstable under present climatic conditions but conditions may have been different in the past. The planet has been volcanically active throughout its history. The combination of water and volcanism must have commonly resulted in hydrothermal environments similar to those in which grow the most primitive terrestrial life-forms.

Atmosphere↗
PubMed1992

History of water on Mars: a biological perspective.

We divide the history of water on the Martian surface into four epochs based upon the atmospheric temperature and pressure. In Epoch 1, during which a primordial CO2 atmosphere was actively maintained by impact and volcanic recycling, we presume the mean annual temperature to have been above freezing, the pressure to have exceeded one atmosphere, and liquid water to have been widespread. Under such conditions, similar to early Earth, life could have arisen and become abundant. After this initial period of recycling, atmospheric CO2 was irreversibly lost due to carbonate formation and the pressure and temperature declined. In Epoch II, the mean annual temperature fell below freezing but peak temperatures would have exceeded freezing. Ice covered lakes, similar to those in the McMurdo Dry Valleys of Antarctica could have provided a habitat for life. In Epoch III, the mean and peak temperatures were below freezing and there would have been only transient liquid water. Microbial ecosystems living in endolithic rock "greenhouses" could have continued to survive. Finally, in Epoch IV, the pressure dropped to near the triple point pressure of water and liquid water could no longer have existed on the surface and life on the surface would have become extinct.

Antarctic Regions↗
PubMed2005

Effects of HZE particle on the nigrostriatal dopaminergic system in a future Mars mission.

Because of long duration travel outside the Earth's magnetic field, the effect of iron-rich high charge and energy (HZE) particles in Galactic Cosmic Rays on human body is the major concern in radiation protection. Recently attention has been directed to effects on the central nervous system in addition to mutagenic effects. In particular, a reduction in striatal dopamine content on nigrostriatal dopaminergic system has been reported by investigators using accelerated iron ions in ground-based mammalian studies. In addition, studies of the pathophysiology of Parkinson's disease demonstrated that excess iron cause a reduction in the dopamine content in the substantia nigra. This suggests an intriguing possibility to explain the selective detrimental effects of HZE particles on the dopaminergic system. Should these particles have biochemical effects, possible options for countermeasures are: (1) nutritional prevention, (2) medication, and (3) surgical placement of a stimulator electrode at a specific anatomic site in the basal ganglia.

Animals↗