Survey of aquatic bugs' species in Bankim, a new endemic area in Cameroon

Bankim district located in the Northern part of Cameroon (Adamaoua region: N 06°04\u2705" E 10°27\u2737"), has been recently described as a new endemic site in Cameroon. This region benefited from the construction of a dam which considerably modified the environment. Previous collections of some aquatic bugs in this region were shown positive for M. ulcerans. But aquatic bugs’ biodiversity and biology still poorly documented. In the afore-mentioned context the present study was carried out to identify the commonly occurring medium and large size aquatic bugs fauna and workout their relative abundance, diversity  according to type of water bodies and comparing with those trap in the night by light trap.  Insects were collected daily from June 1st to June 30 2010 in ponds formed around dam flooded area, in streams and a river. Light traps made up of a 250 W bulb connected to an electrical generator put in front of a white sheet, were installed from 6 PM to 11PM during one lunar cycle, in 3 sites (near the dam, near habitations and in the forest) in the same month.  We collected 338 aquatic bugs in different water bodies belonging to 6 families. Belostomatidae was numerically the most abundant group constituting of 33.13 % of the total aquatic insects followed by Naucoridae, Ranatridae (27.81%, 18.63%).  The other families identified were Nepidae, Notonectidae, and of Gerridae representing respectively 9.46%, 5.91% and 5.02%. All families identified were present in streams and ponds but only two families (Ranatridae and Nepidae) were collected in the river;  Among these 338 aquatic bugs, 59.17% (200) were collected in the streams, 38.16% (129) in the ponds and only 9 (2.66%) in the river. Through the light trap only 2 families were identified among a total of 390 aquatic bugs caught. Belostomatidae , predominant with 80.51% and Notonectidae 19.49%. Notonectidae were caught all along the month and during the full moon, but Belostomatidae were absent during full moon. According to the site of collection, we obtained 25.64% (100) of Belostomatidae and 11.94% (46) of Notonectidae near the dam; near habitations 21.53% (84) of Belostomatidae and 2.56% (10) of Notonectidae and in the forest, 33.33% (130) of Belostomatidae and 5.12% (20) of Notonectidae. This preliminary entomological survey shows the variation of aquatic bugs\u27 diversity according to the types of water bodies in the same endemic region and according to light attraction and the moon phases.

Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

Electron paramagnetic resonance and other properties of hydrogenases isolated from Desulfovibrio vulgaris (strain Hildenborough) and Megasphaera elsdenii

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65872/1/j.1432-1033.1983.tb07727.x.pd

Structure of a dioxygen reduction enzyme from Desulfovibrio gigas

Desulfovibrio gigas is a strict anaerobe that contains a well-characterized metabolic pathway that enables it to survive transient contacts with oxygen. The terminal enzyme in this pathway, rubredoxin:oxygen oxidoreductase (ROO) reduces oxygen to water in a direct and safe way. The 2.5 Angstrom resolution crystal structure of ROO shows that each monomer of this homodimeric enzyme consists of a novel combination of two domains, a flavodoxin-like domain and a Zn-beta -lactamase-like domain that contains a di-iron center for dioxygen reduction. This is the first structure of a member of a superfamily of enzymes widespread in strict and facultative anaerobes, indicating its broad physiological significance

Microbial Maintenance: A Critical Review on Its Quantification

Microbial maintenance is an important concept in microbiology. Its quantification, however, is a subject of continuous debate, which seems to be caused by (1) its definition, which includes nongrowth components other than maintenance; (2) the existence of partly overlapping concepts; (3) the evolution of variables as constants; and (4) the neglect of cell death in microbial dynamics. The two historically most important parameters describing maintenance, the specific maintenance rate and the maintenance coefficient, are based on partly different nongrowth components. There is thus no constant relation between these parameters and previous equations on this subject are wrong. In addition, the partial overlap between these parameters does not allow the use of a simple combination of these parameters. This also applies for combinations of a threshold concentration with one of the other estimates of maintenance. Maintenance estimates should ideally explicitly describe each nongrowth component. A conceptual model is introduced that describes their relative importance and reconciles the various concepts and definitions. The sensitivity of maintenance on underlying components was analyzed and indicated that overall maintenance depends nonlinearly on relative death rates, relative growth rates, growth yield, and endogenous metabolism. This quantitative sensitivity analysis explains the felt need to develop growth-dependent adaptations of existing maintenance parameters, and indicates the importance of distinguishing the various nongrowth components. Future experiments should verify the sensitivity of maintenance components under cellular and environmental conditions