Ethnic polymorphism of DXS52 (St 14) locus linked to coagulation factor VIII gene in Argentina

Sixty-five individuals belonging to 16 argentinian families of hemophilia A were studied using the St 14 probe (DXS52 locus). This probe is widely used for carrier detection and prenatal diagnosis, despite the risk of recombination between the factor VIII gene and the DXS52 locus, because of its high informativity. The families are divided in two groups: one group constituted only of metis of Indians according to interview and morphotype and a second group of caucasoids (Spanish essentially and Italian). In this study we have shown some ethnic variations of the TaqI RFLPs in the DXS52 locus. In the allelic system I, (which alleles are numbered from 1 to 8) we have noted an over representation of the larger alleles (2 and 3) and of the allele 8 in both Argentinian groups when compared to the caucasian population already studied in our laboratory. The additional polymorphic TaqI site giving the beta band in the system II (alpha and beta bands) is found more frequently in the Argentinian families than in Caucasians. Some other additional polymorphic sites have been found in generally constant bands giving additional allelic systems, in metis families.     

A brief comparative study of four disposable bubble oxygenators

Four widely used bubble oxygenators-the Optiflo I, the Bentley Q 200 A, the Harvey 200, and the Shiley 100 A-were tested and compared in 182 patients undergoing cardiac valve surgery. Fifty-six cases were performed with normothermia and 126 cases incorporated mild hypothermia (28-30 degrees C). There was no significant difference in the average age of the patients (51 yrs) or the perfusion time (60 min). All components of the extracorporeal circuit were identical, and anesthetic regimens and surgical techniques were also similar. In this study, the Shiley 100 A oxygenator was found to be the most suitable for cases requiring mild hypothermia and was generally considered to be the oxygenator of choice.     

Heterogeneity of glutamine synthetase polypeptides in Neurospora crassa

Purified preparations of Neurospora crassa glutamine synthetase contain two nonidentical polypeptides that can be separated by acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and 7 M urea. These polypeptides are synthesized both in vivo and in a heterologous cell-free protein-synthesizing system. The data presented indicate that both polypeptides contain an active site for glutamine synthetase activity and suggest that there is not a precursor-product relationship between them.     

Enzyme polymorphism in a population of Calomys musculinus (Rodentia,Cricetidae)

NAD-linked lactate, malate, glycerophosphate, alcohol and nonspecific dehydrogenases, aspartate aminotransferases, and soluble esterases from extracts of tissues of individuals from a wild population of Calomys musculinus (Rodentia, Cricetidae) have been analyzed by means of starch gel electrophoresis and specific staining. Allelic frequencies and heterozygosity have been determined. Mendelian inheritance of some of the variants detected was confirmed by breeding experiments. Ten out of fifteen (66.6%) of the genetic loci investigated presented polymorphism. Mean heterozygosity per locus was very high (H=0.2014, se 0.046).This work has been supported, in part, by grants from the Secretaria de Ciencia y Tecnología de la Nación (National Program for Endemic Diseases) and from the Fundación Emilio Ocampo. C. N. G. is a Fellow and A. B. a Career Investigator of the Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina.     

Role of the bacterial and phage recombination systems and of DNA replication in genetic recombination of UV-irradiated phage lambda

Summary In this paper are studied in E. coli K12 the influence of the bacterial Rec and phage Red recombination systems on the rescue of the O ⁺ gene from the prophage by a superinfecting O ^- phage, UV irradiated or not. In the absence of UV irradiation the Red system produces more recombinants that does the Rec system, and its action requires DNA replication. The presence of UV lesions in the DNA facilitates the action of the Rec system, which is more efficient in this instance than the Red system and can act in the absence of DNA replication. In all cases, there is a cooperation between the two generalized recombination systems.     

Resultados comparativos de la reaccion intradermica a la tuberculina - histoplasmina- coccidioidina en Tuberculosos

Mycopathologia - Se estudiaron los resultados comparativos de las reacciones intradérmicas a la Tuberculina, Histoplasmina y Coccidioidina, practicadas simultáneamente a 644 enfermos...     

Interface processes between protected and unprotected areas: A global review and ways forward

Land‐use changes and the expansion of protected areas (PAs) have amplified the interaction between protected and unprotected areas worldwide. In this context, ‘interface processes' (human–nature and cross‐boundary interactions inside and around PAs) have become central to issues around the conservation of biodiversity and ecosystem services. This scientific literature review aimed to explore current knowledge and research gaps on interface processes regarding terrestrial PAs. At first, 3,515 references related to the topic were extracted through a standardized search on the Web of Science and analyzed with scientometric techniques. Next, a full‐text analysis was conducted on a sample of 240 research papers. A keyword analysis revealed a wide diversity of research topics, from ‘pure' ecology to sociopolitical research. We found a bias in the geographical distribution of research, with half the papers focusing on eight countries. Additionally, we found that the spatial extent of cross‐boundary interactions was rarely assessed, preventing any clear delimitation of PA interactive zones. In the 240 research papers we scanned, we identified 403 processes that were studied. The ecological effects of PAs were well documented and appeared to be positive overall. In contrast, the effects of PAs on local communities were understudied and, according to the literature focusing on these, were very variable according to local contexts. Our findings highlight key research advances on interface processes, especially regarding the ecological outcomes of PAs, the influence of human activities on biodiversity, and PA governance issues. In contrast, main knowledge gaps concern the spatial extent of interactive zones, as well as the interactions between local people and conservation actions and how to promote synergies between them. While the review was limited to terrestrial PAs, its findings allow us to propose research priorities for tackling environmental and socioeconomic challenges in the face of a rapidly changing world.     

Living in tiny fragments: a glimpse at the ecology of Goodman’s mouse lemurs (Microcebus lehilahytsara) in the relic forest of Ankafobe,Central Highlands,Madagascar

Primates - Habitat fragmentation is one of the major types of anthropogenic change, though fragmented landscapes predate human intervention. At present, the Central Highlands of Madagascar are...