Phylogeny of Thylamys (Didelphimorphia, Didelphidae) species, with special reference to Thylamys karimii

The genus Thylamys Gray, 1843 lives in the central and southern portions of South America inhabiting open and shrub-like vegetation, from prairies to dry forest habitats in contrast to the preference of other Didelphidae genera for more mesic environments. Thylamys is a speciose genus including T. elegans (Waterhouse, 1839), T. macrurus (Olfers, 1818), T. pallidior (Thomas, 1902), T. pusillus (Desmarest, 1804), T. venustus (Thomas, 1902), T. sponsorius (Thomas, 1921), T. cinderella (Thomas, 1902), T. tatei (Handley, 1957), T. karimii (Petter, 1968), and T. velutinus (Wagner, 1842) species. Previous phylogenetic analyses in this genus did not include the Brazilian species T. karimii, which is widely distributed in this country. In this study, phylogenetic analyses were performed to establish the relationships among the Brazilian T. karimii and all other previously analyzed species. We used 402-bp fragments of the mitochondrial cytochrome b gene, and the phylogeny estimates were conducted employing maximum parsimony (MP), maximum likelihood (ML), Bayesian (BY), and neighbor-joining (NJ). The topologies of the trees obtained in the different analyses were all similar and pointed out that T. karimii is the sister taxon of a group constituted of taxa from dry and arid environments named the dryland species. The dryland species consists of T. pusillus, T. pallidior, T. tatei, and T. elegans. The results of this work suggest five species groups in Thylamys. In one of them, T. velutinus and T. kariimi could constitute a sister group forming one Thylamys clade that colonized Brazil.

The birds of Sibuyan Island, Romblon Province, Philippines : with particular reference to elevational distribution and biogeographic affinities / Steven M. Goodman, David E. Willard, Pedro C. Gonzales.

n.s. no.82(1995)

Sino-Iranica; Chinese contributions to the history of civilization in ancient Iran, with special reference to the history of cultivated plants and products / by Berthold Laufer --

v.15:no.3(1919)

A bibliography of birds : with special reference to anatomy, behavior, biochemistry --. by Reuben Myron Strong.

v.25:pt.1(1939)

A bibliography of birds : with special reference to anatomy, behavior, biochemistry --. by Reuben Myron Strong

v.25:pt.3(1946)

A bibliography of birds : with special reference to anatomy, behavior, biochemistry --. Reuben Myron Strong.

v.25:pt.2(1939)

A bibliography of birds : with special reference to anatomy, behavior, biochemistry --. by Reuben Myron Strong

v.25:pt.4(1959)

Reference prices: the spanish way

The aim of this paper is to analyse the effects of recent regulatory reforms that Spanish Health Authorities have implemented in the pharmaceutical market: the introduction of a reference price system together with the promotion of generic drugs. The main objectives of these two reforms are to increase price competition and, ultimately, reduce pharmaceutical costs. Before the introduction of reference prices, consumers had to pay a fixed copayment of the price of whatever drug purchased. With the introduction of such system, the situation differs in the following way: if (s)he buys the more expensive branded drug, then (s)he pays a sum of two elements: the copayment associated to the reference price plus the difference between the price of this good and the reference price. However, if the consumer decides to buy the generic alternative, with price lower than the reference price, then (s)he has to pay the same copayment as before. We show that the introduction of a reference price system together with the promotion of generic drugs increase price competition and lower pharmaceutical costs only if the reference price is set in a certain interval. Also profits for the duopolists might be reduced. These results are due to the opposing effects that reference prices have on branded and generic producers respectively.

Malignant transformation of a rat fibroma by the treatment with an anti-fibrosing drug: CY-168F (Plastenan)

Fifteen albino (Sprague Dawley) rats with subcutaneous transplanted fibromas was used in the present study. The tumour was formed by typical fibroblasts in a dense collagen matrix and was provenient from a fibroma that appeared spontaneously in an albino rat of the same strain. Ultrastructurally collagen disclosed normal periodicity and the fibroblasts showed irregular notched nuclei with irregular distribution of chromatin, that suggests transitional aspects to fibrosarcoma. The 15 animals, from different passage groups, were divided into: 8 animals submitted to treatment with the drug acexamic acid (CY-168F) - N acetyl-amino-6-hexanoic acid (plastenan) and 7 untreated control animals. Three of the treated animals showed a malignant transformation to fibrosarcoma. transitional histological features from typical fibroma to highly indifferentiated fibrosarcoma could be detected in come animal subjected to repeated biopsies. Ultrastructural study disclosed nuclear alterations and hyperactive ergastoplasm and collagen containing inclusions into the cytoplasm of fibroblasts. In the group of 7 untreated naimals, no malignant transformation could be detected histologically. Two aspects deserve attention: the malignant potential of a typical fibroma and the apparent effect of an antifibrosing drug in inducing malignization of this tumour.

Taxonomical and biogeographical problems in Mediterranean shrews of the genus Crocidura (Mammalia, Insectivora) with reference to a new karyotype from Sicily (Italy)

Shrews of the genus Crocidura from Sicily revealed a new karyotype from Europe: 2n = 36, NF = 56, NFa = 52. With reference to the revision of Vesmanis (1976), this shrew is provisionally attributed to C. caudata Miller, 1901 and it is proposed to call it the "Sicilian shrew". Its chromosome complement is similar to that of shrews from Canary Islands and a species from Burundi (Central Africa), suggesting that it might have split off from a line of Paleotropical origin. Following these findings, the modern concept of Mediterranean island colonization by shrews must be revised. The distinctive characteristics of Mediterranean shrews should also be revised.

Olfactory traces and spatial learning in rats.

We conducted an experiment to assess the use of olfactory traces for spatial orientation in an open environment in rats, Rattus norvegicus. We trained rats to locate a food source at a fixed location from different starting points, in the presence or absence of visual information. A single food source was hidden in an array of 19 petri dishes regularly arranged in an open-field arena. Rats were trained to locate the food source either in white light (with full access to distant visuospatial information) or in darkness (without any visual information). In both cases, the goal was in a fixed location relative to the spatial frame of reference. The results of this experiment revealed that the presence of noncontrolled olfactory traces coherent with the spatial frame of reference enables rats to locate a unique position as accurately in darkness as with full access to visuospatial information. We hypothesize that the olfactory traces complement the use of other orientation mechanisms, such as path integration or the reliance on visuospatial information. This experiment demonstrates that rats can rely on olfactory traces for accurate orientation, and raises questions about the establishment of such traces in the absence of any other orientation mechanism. Copyright 1998 The Association for the Study of Animal Behaviour.

Detection of testosterone administration based on the carbon isotope ratio profiling of endogenous steroids: international reference populations of professional soccer players.

BACKGROUND AND OBJECTIVES: The determination of the carbon isotope ratio in androgen metabolites has been previously shown to be a reliable, direct method to detect testosterone misuse in the context of antidoping testing. Here, the variability in the 13C/12C ratios in urinary steroids in a widely heterogeneous cohort of professional soccer players residing in different countries (Argentina, Italy, Japan, South Africa, Switzerland and Uganda) is examined. METHODS: Carbon isotope ratios of selected androgens in urine specimens were determined using gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS). RESULTS: Urinary steroids in Italian and Swiss populations were found to be enriched in 13C relative to other groups, reflecting higher consumption of C3 plants in these two countries. Importantly, detection criteria based on the difference in the carbon isotope ratio of androsterone and pregnanediol for each population were found to be well below the established threshold value for positive cases. CONCLUSIONS: The results obtained with the tested diet groups highlight the importance of adapting the criteria if one wishes to increase the sensitivity of exogenous testosterone detection. In addition, confirmatory tests might be rendered more efficient by combining isotope ratio mass spectrometry with refined interpretation criteria for positivity and subject-based profiling of steroids.