CtpA,a Copper-translocating P-type ATPase Involved in the Biogenesis of Multiple Copper-requiring Enzymes

The ctpA (ccoI) gene product, a putative inner membrane copper-translocating P1B-type ATPase present in many bacteria, has been shown to be involved only in the cbb₃ assembly in Rhodobacter capsulatus and Bradyrhizobium japonicum. ctpA was disrupted in Rubrivivax gelatinosus, and the mutants showed a drastic decrease in both cbb₃ and caa₃ oxidase activities. Inactivation of ctpA results also in a decrease in the amount of the nitrous oxide reductase, NosZ. This pleiotropic phenotype could be partially rescued by excess copper in the medium, indicating that CtpA is likely a copper transporter that supplies copper-requiring proteins in the membrane with this metal. Although CtpA shares significant sequence homologies with the homeostasis copper efflux P1B-type ATPases including the bacterial CopA and the human ATP7A and ATP7B, disruption of ctpA did not result in any sensitivity to excess copper. This indicates that the CtpA is not crucial for copper tolerance but is involved in the assembly of membrane and periplasmic copper enzymes in this bacterium. The potential roles of CtpA in bacteria in comparison with CopA are discussed.     

Simulation of the cardiovascular system using equivalent electronic system

This paper describes simulation of the cardiovascular system using a complex electronic circuit. In this study we have taken a slightly different approach to the modeling of the system and tried to advance existing electrical models by increasing more segments and parameters. The model consists of 42 segments representing the arterial system. Anatomical and physiological data for circuit parameters have been extracted from medical articles and textbooks. The frequency of heart is 1 Hz and the system operates in steady state condition. Each artery is modeled by one capacitor, resistor and inductor. The left and right ventricles are modeled using AC power suppliers and diodes. The results of the simulation including pressure and volume graphs exhibit operation of the cardiovascular system under normal condition. The results of the simulation have been compared with the relevant experimental observation and are in good agreement with them.     

FOOD AND FEEDING ECOLOGY OF THE COMMON DOLPHIN (DELPHINUS DELPHIS) IN THE OCEANIC NORTHEAST ATLANTIC AND COMPARISON WITH ITS DIET IN NERITIC AREAS

The short-beaked common dolphin, Delphinus delphis , is abundant in both neritic and oceanic habitats. These two domains differ largely in terms of the nature of forage organisms and their availability to surface-bound top predators, which suggests that the common dolphin should show extensive variability in foraging strategies as a response to these different habitats. However, although its diet is well known over continental shelves, so far, mostly because of sampling issues, nothing has been published on its diet in oceanic habitats. In this study, the diet of sixty-three common dolphins bycaught in the French albacore tuna driftnet fishery in the summers of 1992–1993 in the oceanic Bay of Biscay was determined from their stomach contents and compared to neritic studies. The diet was dominated by fish (90% by number [N] and 53% by mass of total diet [M]). Cephalopods were also important in the total diet (9%N, 46%M) but were a prey of secondary importance in the fresh fraction (3%N, 10%M), presumably due to longer retention of cephalopod remains in the stomach. Crustaceans were of minor importance. At the species level, the myctophid fish ( Notoscopelus kroeyeri ) largely dominated the diet. Prey size ranged from 1 to 68 cm, but the majority of preys were from 2 to 30 cm. The prey characteristics and their state of digestion suggest that the common dolphin forages preferentially on small schooling, vertically migrating mesopelagic fauna in the surface layer at dusk and early night. The diet is taxonomically distinct from results obtained in neritic studies but is similar in terms of prey type and the corresponding feeding behavior.     

Bicoid Signal Extraction with a Selection of Parametric and Nonparametric Signal Processing Techniques

The maternal segmentation coordinate gene bicoid plays a significant role during Drosophila embryogenesis. The gradient of Bicoid, the protein encoded by this gene, determines most aspects of head and thorax development. This paper seeks to explore the applicability of a variety of signal processing techniques at extracting bicoid expression signal, and whether these methods can outperform the current model. We evaluate the use of six different powerful and widely-used models representing both parametric and nonparametric signal processing techniques to determine the most efficient method for signal extraction in bicoid. The results are evaluated using both real and simulated data. Our findings show that the Singular Spectrum Analysis technique proposed in this paper outperforms the synthesis diffusion degradation model for filtering the noisy protein profile of bicoid whilst the exponential smoothing technique was found to be the next best alternative followed by the autoregressive integrated moving average.     

Intermittent preventive treatment of malaria provides substantial protection against malaria in children already protected by an insecticide-treated bednet in Burkina Faso: a randomised, double-blind, placebo-controlled trial

Background

Intermittent preventive treatment of malaria in children (IPTc) is a promising new approach to the control of malaria in areas of seasonal malaria transmission but it is not known if IPTc adds to the protection provided by an insecticide-treated net (ITN).

Methods and Findings

An individually randomised, double-blind, placebo-controlled trial of seasonal IPTc was conducted in Burkina Faso in children aged 3 to 59 months who were provided with a long-lasting insecticide-treated bednet (LLIN). Three rounds of treatment with sulphadoxine pyrimethamine plus amodiaquine or placebos were given at monthly intervals during the malaria transmission season. Passive surveillance for malaria episodes was established, a cross-sectional survey was conducted at the end of the malaria transmission season, and use of ITNs was monitored during the intervention period. Incidence rates of malaria were compared using a Cox regression model and generalized linear models were fitted to examine the effect of IPTc on the prevalence of malaria infection, anaemia, and on anthropometric indicators. 3,052 children were screened and 3,014 were enrolled in the trial; 1,505 in the control arm and 1,509 in the intervention arm. Similar proportions of children in the two treatment arms were reported to sleep under an LLIN during the intervention period (93%). The incidence of malaria, defined as fever or history of fever with parasitaemia ≥5,000/µl, was 2.88 (95% confidence interval [CI] 2.70–3.06) per child during the intervention period in the control arm versus 0.87 (95% CI 0.78–0.97) in the intervention arm, a protective efficacy (PE) of 70% (95% CI 66%–74%) (p<0.001). There was a 69% (95% CI 6%–90%) reduction in incidence of severe malaria (p = 0.04) and a 46% (95% CI 7%–69%) (p = 0.03) reduction in the incidence of all-cause hospital admissions. IPTc reduced the prevalence of malaria infection at the end of the malaria transmission season by 73% (95% CI 68%–77%) (p<0.001) and that of moderately severe anaemia by 56% (95% CI 36%–70%) (p<0.001). IPTc reduced the risks of wasting (risk ratio [RR] = 0.79; 95% CI 0.65–1.00) (p = 0.05) and of being underweight (RR = 0.84; 95% CI 0.72–0.99) (p = 0.03). Children who received IPTc were 2.8 (95% CI 2.3–3.5) (p<0.001) times more likely to vomit than children who received placebo but no drug-related serious adverse event was recorded.

Conclusions

IPT of malaria provides substantial protection against malaria in children who sleep under an ITN. There is now strong evidence to support the integration of IPTc into malaria control strategies in areas of seasonal malaria transmission.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00738946","term_id":"NCT00738946"}}NCT00738946 Please see later in the article for the Editors'' Summary