Nest size and hatchling sex ratio in chinstrap penguins

Variation in the sex ratio at hatching in the chinstrap penguin Pygoscelis antarctica was investigated, using molecular sexing to test predictions of sex allocation theory. The sex ratio was slightly male-biased (0.54) but did not differ significantly from parity. The proportion of males increased with nest size, an estimator of parental quality in chinstrap penguins. High-quality parents were able to produce and rear a higher proportion of male offspring, the more costly sex in this slightly sexually dimorphic species. Our results may be in agreement with Trivers and Willards (1973) argument on biases in the offspring sex ratio being contingent on parental condition or quality.     

Cytochemical location of urease in the cell wall of two different lichen phycobionts

The enzyme urease has been located in the cell wall of recently isolated phycobionts from Evernia prunastri and Xanthoria parietina lichens. Cytochemical detection is achieved by producing a black, electron-dense precipitate of cobalt sulfide proceeding from CO(2) evolved from urea in the presence of cobalt chloride. Cellular fractionation reveals that about 80% of total urease activity was associated to the cell wall on both phycobionts whereas only 20% was recovered as soluble protein.     

Chemoenzymatic synthesis and biological evaluation of C-3 carbamate analogues of 1alpha,25-dihydroxyvitamin D3

The synthesis of new analogues of 1alpha,25-dihydroxyvitamin D3 containing a carbamate function at the A-ring fragment has been described using the cross-coupling approach. The carbamate group was selectively introduced at the C-3 position by regioselective enzymatic alkoxycarbonylation of A-ring enyne 3 and subsequent treatment with ammonia, amines, amino alcohols, and amino acids. Biological studies to evaluate the potency of all five of these carbamate analogues were performed and demonstrated very low binding affinity for the vitamin D receptor compared with 1alpha,25-dihydroxyvitamin D3. Moreover, all the carbamate analogues were less active than 1alpha,25-dihydroxyvitamin D3 in inhibiting cell proliferation or stimulating cell differentiation. Of all the five analogues, the 3-O-carbamoyl-1alpha,25-(OH)2-D3 analogue 10a was the most potent one in vitro. However, all investigated carbamate analogues demonstrated lower calcemic effects in vivo than the parent compound.     

Use of surname models in human population biology: a review of recent developments

Since 1985, when a bibliography concerning studies on surnames and genetic structure appeared, the number of publications on this subject has increased a thousandfold. New topics and uses have been added, but large gaps in knowledge remain. Only studies on isonymy in cities of nation states for recent times are well covered, and most studies are on populations that were selected because they are isolated and not because they are typical. This review, although not exhaustive, covers the literature published since 1985.     

Tumor cytotoxicity by endothelial cells. Impairment of the mitochondrial system for glutathione uptake in mouse B16 melanoma cells that survive after in vitro interaction with the hepatic sinusoidal endothelium

High GSH content associates with high metastatic activity in B16-F10 melanoma cells cultured to low density (LD B16M). GSH homeostasis was investigated in LD B16M cells that survive after adhesion to the hepatic sinusoidal endothelium (HSE). Invasive B16M (iB16M) cells were isolated using anti-Met-72 monoclonal antibodies and flow cytometry-coupled cell sorting. HSE-derived NO and H(2)O(2) caused GSH depletion and a decrease in gamma-glutamylcysteine synthetase activity in iB16M cells. Overexpression of gamma-glutamylcysteine synthetase heavy and light subunits led to a rapid recovery of cytosolic GSH, whereas mitochondrial GSH (mtGSH) further decreased during the first 18 h of culture. NO and H(2)O(2) damaged the mitochondrial system for GSH uptake (rates in iB16M were approximately 75% lower than in LD B16M cells). iB16M cells also showed a decreased activity of mitochondrial complexes II, III, and IV, less O(2) consumption, lower ATP levels, higher O(2) and H(2)O(2) production, and lower mitochondrial membrane potential. In vitro growing iB16M cells maintained high viability (>98%) and repaired HSE-induced mitochondrial damages within 48 h. However, iB16M cells with low mtGSH levels were highly susceptible to TNF-alpha-induced oxidative stress and death. Therefore depletion of mtGSH levels may represent a critical target to challenge survival of invasive cancer cells.     

First report of Lappetascaris lutjani Rasheed, 1965 (Nematoda, Ascaridoidea, Anisakidae) parasitizing Trachipterus arawatae (Pisces, Lampridiformes) on the Atlantic coast of Brazil

New host and geographical records are reported for the nematode Lappetascaris lutjani Rasheed, 1965, parasitizing the marine fish Trachipterus arawatae Clark, 1881 in Brazilian waters. Morphometric data and illustrations of the parasites are included.     

Integration of the cytogenetic and genetic linkage maps of Brassica oleracea

We have assigned all nine linkage groups of a Brassica oleracea genetic map to each of the nine chromosomes of the karyotype derived from mitotic metaphase spreads of the B. oleracea var. alboglabra line A12DHd using FISH. The majority of probes were BACs, with A12DHd DNA inserts, which give clear, reliable FISH signals. We have added nine markers to the existing integrated linkage map, distributed over six linkage groups. BACs were definitively assigned to linkage map positions through development of locus-specific PCR assays. Integration of the cytogenetic and genetic linkage maps was achieved with 22 probes representing 19 loci. Four chromosomes (2, 4, 7, and 9) are in the same orientation as their respective linkage groups (O4, O7, O8, and O6) whereas four chromosomes (1, 3, 5, and 8) and linkage groups (O3, O9, O2, and O1) are in the opposite orientation. The remaining chromosome (6) is probably in the opposite orientation. The cytogenetic map is an important resource for locating probes with unknown genetic map positions and is also being used to analyze the relationships between genetic and cytogenetic maps.     

Status and metabolism of iron in elite sportsmen during a period of professional competition

The aim of this study was to determine the effect of both acute exercise and maintained training during a period of competition (3 mo, at the start of the season) on iron metabolism in sportsmen on a professional volleyball team. Twelve sportsmen volunteered for this study. The exercise test was performed on a mechanically braked Monark cycle ergometer and consisted of a triangular progressive test. Three blood samples were obtained in each test: at rest, just after exercise, and after recovery. The following hematological parameters were determined: red blood count (RBC), hemoglobin (Hb) and hematocrit (Hto), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), total proteins (TP), serum iron (Fe) and total iron-binding capacity (TIBC), ferritin (FER), transferrin (TRF), haptoglobin (HPT), and serum cortisol (COR) concentrations. We have found changes in hematological and biochemical variables related to Fe metabolism during the study. The changes observed could be the result of hemoconcentration processes after exercise and, at least in part, to physical stress and muscular damage. We conclude that athletes, after a period of adaptation, with a good plan of work/recovery series, undergo a biological redistribution on hematological and biochemical parameters concerning Fe metabolism during the training and competition period. Also, daily Fe supplementation could restore and mask the true repercussions of maintained training observed in other sports.     

Effect of an asynchrony between ovulation and insemination on the results obtained after insemination with fresh or frozen sperm in rabbits

The effects of the introduction of an 8-h asynchrony between ovulation and insemination on litter size components from rabbits were assessed. A total of 202 females belonging to a maternal line were used. Fresh and frozen sperm were used to perform the inseminations. Sperm was frozen with an extender composed of 1.75 M DMSO and 0.05 M sucrose. Four experimental groups were obtained depending on the type of sperm used (fresh or frozen) and on the moment that ovulation had been induced relative to the insemination (at the same time as insemination (t(0)) or 8 h before insemination (t(8))). Laparoscopy was performed on 12th day of pregnancy in pregnant females, and the ovulation rate, normal and total implanted embryos were noted. At kindling, total and live-born rabbits were noted. Results showed that better results were obtained after insemination with fresh semen than with frozen sperm (for females in the group t(0): 79% versus 61% fertility rate, 10.2 versus 6.4 normal implanted embryos and 8.1 versus 5.2 total number born, for fresh and frozen sperm, respectively). On the other hand, after the introduction of an 8-h asynchrony between ovulation and insemination, results were lower for both fresh (50% fertility rate, 7.5 normal implanted embryos and 5.7 total number born for the group of the asynchrony) and frozen sperm (31% fertility rate, 4.6 normal implanted embryos and 3.4 total number born for the group of the asynchrony). Although an approach between the moment of insemination and ovulation is justified when sperm survival could be compromised, results observed after the induction of an 8-h asynchrony were not those expected, perhaps due to the ageing of the oocytes before being fertilised, leading to both lack of fertilisation or early embryonic mortality.