Enhanced Biodegradation of Casablanca Crude Oil by A Microbial Consortium in Presence of a Rhamnolipid Produced by Pseudomonas Aeruginosa AT10

The biodegradation of oil products in the environment is often limited by their low water solubility and dissolution rate. Rhamnolipids produced by Pseudomonas aeruginosa AT10 were investigated for their potential to enhance bioavailability and hence the biodegradation of crude oil by a microbial consortium in liquid medium. The characterization of the rhamnolipids produced by strain AT10 showed the effectiveness of emulsification of complex mixtures. The addition of rhamnolipids accelerates the biodegradation of total petroleum hydrocarbons from 32% to 61% at 10 days of incubation. Nevertheless, the enhancement of biosurfactant addition was more noticeable in the case of the group of isoprenoids from the aliphatic fraction and the alkylated polycyclic aromatic hydrocarbons (PHAS) from the aromatic fraction. The biodegradation of some targeted isoprenoids increased from 16% to 70% and for some alkylated PAHs from 9% to 44%.     

Effect of gestational and postnatal environmental temperature on metabolic rate in the altricial rodent, Phyllotis darwini

1. In the altricial rodent, Phyllotis darwini, we found higher body temperatures and faster developmental rates of the thermoregulatory capacity in neonates born from cold- than warm-acclimated mothers.

2. This difference could be explained by maternal effects on the litter, such as high levels of catecholamines and thyroxin levels, high concentration of the uncoupled protein and larger quantity of brown adipose tissue as a consequence of cold acclimation.

3. The exposition of mothers and the maintenance of cold condition during the early development might be responsible of the high metabolism and better thermoregulatory capacity of newborns.

Crystal structure of the alpha, beta, gamma-tridentate manganese complex of adenosine 5'-triphosphate cocrystallized with 2,2'-dipyridylamine

The 1:1:1 complex of Mn2+, ATP, and 2,2'-dipyridylamine (DPA) crystallizes as Mn-(HATP)2.Mn(H2O)6.(HDPA)2.12H2O in the orthorhombic space group C222(1) with unit cell dimensions a = 10.234 (3) A, b = 22.699 (3) A, and c = 31.351 (4) A. The structure was solved by the multisolution technique and refined by the least-squares method to a final R index of 0.072 using 3516 intensities. The structure is composed of two ATP molecules sharing a common manganese atom. The metal exhibits alpha, beta, gamma coordination to the triphosphate chains of two dyad-related ATP molecules, resulting in a hexacoordinated Mn2+ ion surrounded by six phosphate groups. The metal to oxygen distances are 2.205 (6), 2.156 (4), and 2.144 (5) A for the alpha-, beta-, and gamma-phosphate groups, respectively. No metal-base interactions are observed. There is a second hexaaqua-coordinated Mn2+ ion that is also located on a dyad axis. The hydrated manganese ions sandwich the phosphate-coordinated manganese ions in the crystal with a metal-metal distance of 5.322 A. The ATP molecule is protonated on the N(1) site of the adenine base and exhibits the anti conformation (chi = 66.0 degrees). The ribofuranose ring is in the 2/3 T conformation with pseudorotation parameters P = 179 (1) degrees and tau m = 34.1 (6) degrees. The adenine bases form hydrogen-bonded self-pairs across a crystallographic dyad axis and stack with both DPA molecules to form a column along the dyad. The structure of the metal-ATP complex provides information about the possible metal coordination, conformation, and environment of the nucleoside triphosphate substrate in the enzyme.     

Terrestrial birds in coastal environments: metabolic rate and oxidative status varies with the use of marine resources

Oecologia - Life in saline environments represents a major physiological challenge for birds, particularly for passerines that lack nasal salt glands and hence are forced to live in environments...     

Improved Pancreatic Adenocarcinoma Diagnosis in Jaundiced and Non-Jaundiced Pancreatic Adenocarcinoma Patients through the Combination of Routine Clinical Markers Associated to Pancreatic Adenocarcinoma Pathophysiology

Background

There is still no reliable biomarker for the diagnosis of pancreatic adenocarcinoma. Carbohydrate antigen 19–9 (CA 19–9) is a tumor marker only recommended for pancreatic adenocarcinoma follow-up. One of the clinical problems lies in distinguishing between this cancer and other benign pancreatic diseases such as chronic pancreatitis. In this study we will assess the value of panels of serum molecules related to pancreatic cancer physiopathology to determine whether alone or in combination could help to discriminate between these two pathologies.

Methods

CA 19–9, carcinoembryonic antigen (CEA), C-reactive protein, albumin, insulin growth factor-1 (IGF-1) and IGF binding protein-3 were measured using routine clinical analyzers in a cohort of 47 pancreatic adenocarcinoma, 20 chronic pancreatitis and 15 healthy controls.

Results

The combination of CA 19–9, IGF-1 and albumin resulted in a combined area under the curve (AUC) of 0.959 with 93.6% sensitivity and 95% specificity, much higher than CA 19–9 alone. An algorithm was defined to classify the patients as chronic pancreatitis or pancreatic cancer with the above specificity and sensitivity. In an independent validation group of 20 pancreatic adenocarcinoma and 13 chronic pancreatitis patients, the combination of the four molecules classified correctly all pancreatic adenocarcinoma and 12 out of 13 chronic pancreatitis patients.

Conclusions

Although this panel of markers should be validated in larger cohorts, the high sensitivity and specificity values and the convenience to measure these parameters in clinical laboratories shows great promise for improving pancreatic adenocarcinoma diagnosis.     

Nucleotide sequence analysis of the lemur beta-globin gene family: evidence for major rate fluctuations in globin polypeptide evolution

Lemur beta-related globin genes have been isolated and sequenced. Orthology of prosimian and human epsilon-, gamma-, and beta-related globin genes was established by dot-matrix analysis. All of these lemur globin genes potentially encode functional beta-related globin polypeptides, though precisely when the gamma-globin gene is expressed remains unknown. The organization of the 18-kb brown lemur beta-globin gene cluster (5' epsilon-gamma-[psi eta-delta]-beta 3') is consistent with its evolution by contraction via unequal crossing-over from the putative ancestral mammalian beta-globin gene cluster (5' epsilon-gamma- eta-delta-beta 3'). The dwarf lemur nonadult globin genes are arranged as in the brown lemur. Similar levels of synonymous (silent) nucleotide substitutions and noncoding DNA sequence differences have accumulated between species in all of these genes, suggesting a uniform rate of noncoding DNA divergence throughout primate beta-globin gene clusters. These differences are comparable with those observed in the nonfunctional psi eta pseudogene and have therefore accumulated at the presumably maximal neutral rate. In contrast, nonsynonymous (replacement) nucleotide substitutions show a significant heterogeneity in distribution for both the same gene in different lineages and different genes in the same lineage. These major fluctuations in replacement but not silent substitution rates cannot be attributed to changes in mutation rate, suggesting that changes in the rate of globin polypeptide evolution in primates is not governed solely by variable mutation rates.      

Effect of harvesting, vegetation structure and composition on the abundance and demography of the land crab Cardisoma guanhumi in Puerto Rico

Cardisoma guanhumi is the focus of an important artisanal fishery in Puerto Rico. Data on land crab landings point towards a dramatic decline in their abundance. This is cause for concern given the intrinsic value of the fishery and the important role these crabs play in coastal ecosystems. In this paper we examine the effect of harvesting and habitat quality on the abundance, survival, and size structure of C. guanhumi. To accomplish this we conducted a capture-mark-recapture study for a period of 18 months at three localities with minimal or no harvesting, and three with intense harvesting. Habitat quality at the six study sites was assessed by measuring vegetation composition-structure and litter biomass. We also conducted a leaf consumption experiment to evaluate leaf litter selectivity and limitation. Mean crab abundance differed significantly among sites, and this variation was significantly explained by differences in crab survival among sites. Sites with less harvesting tended to have higher survivorship and more crabs than sites where harvesting took place. Crabs mean size differed among study sites and was inversely related to abundance. Vegetation composition and structure, leaf litter standing stock and leaf-litter consumption differed among study sites. However, only some of these habitat characteristics are directly related to crab abundance or demography. There is a tendency for sites with a high leaf litter standing stock and large basal area to have the largest crabs but in low abundance. This study shows that C. guanhumi populations are very sensitive to increases in mortality that result from harvesting, and that the historical decline in abundance of this crab in Puerto Rico can be explained, in part, by an increase in trapping effort. Our results also indicate that C. guanhumi is a very plastic species, capable of occupying diverse types of coastal forests and a leaf litter generalist.     

Body mass,phylogeny and diet composition affects kidney morphology in passerine birds

We studied the renal morphology of 16 species of passerines to assess whether the composition of the diet of birds have been paralleled by differences in the characteristics of the kidneys. We determined the number and length of the medullary cones and the percentage of renal medulla in birds with contrasting dietary habits and then correlated these features with the percentage of nitrogen and proportion of invertebrates in the diet. To examine the correlation between kidney and diet variables, we first used standard correlation and least square regression, and correlation and regression on phylogenetically independent data. We found that the mass of the medullary portion of the kidney, and the medullary cone length were negatively correlated with the percentage of invertebrates present in the diet. We hypothesized that the further development of the renal medulla observed in granivorous birds may be correlated with the small amount of water present in the seeds. Our results suggest that the availability of water in different foods is probably one of the main factors that have led to structural and probably functional changes of the kidney in the studied species. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.