Cytoplasmic incompatibility (CI) describes the phenomenon whereby eggs fertilized by sperm from insects infected with a rickettsial endosymbiont fail to hatch. Unidirectional CI between conspecific ...populations of insects is a well documented phenomenon. Bidirectional CI has, however, only been described in mosquito populations, and recently between closely related species of parasitic wasps, where it is of interest as both an unusual form of reproductive isolation and as a potential means of insect population suppression. Here we report on the first known example of bidirectional CI between conspecific populations of Drosophila simulans. Further, we show that defects as early as the first cleavage division are associated with CI. This observation suggests that the cellular basis of CI involves disruption of processes before or during zygote formation and that CI arises from defects in the structure and/or function of the sperm during fertilization.
Various stocks of Drosophila mauritiana and D. sechellia were found to be infected with Wolbachia, a Rickettsia-like bacterium that is known to cause cytoplasmic incompatibility and other ...reproductive abnormalities in arthropods. Testing for the expression of cytoplasmic incompatibility in these two species showed partial incompatibility in D. sechellia but no expression of incompatibility in D. mauritiana. To determine whether absence of cytoplasmic incompatibility in D. mauritiana was due to either the bacterial or host genome, we transferred bacteria from D. mauritiana into an uninfected strain of D. simulans, a host species known to express high levels of incompatibility with endogenous Wolbachia. We also performed the reciprocal transfer of the natural D. simulans Riverside infection into a tetracycline-treated stock of D. mauritiana. In each case, the ability to express incompatibility was unaltered by the different host genetic background. These experiments indicate that in D. simulans and D. mauritiana expression of the cytoplasmic incompatibility phenotype is determined by the bacterial strain and that D. mauritiana harbors a neutral strain of Wolbachia
Indications and evidence are limited, multiple and complex for emergency tourniquet use. Good recent outcomes challenge historically poor outcomes. Optimal tourniquet use in trauma care appears to ...depend on adequate devices, modern doctrine, refined training, speedy evacuation, and performance improvement. Challenges remain in estimation of blood loss volumes, lesion lethality, and casualty propensity to survive hemorrhage.
Evidence gaps persist regarding emergency tourniquet use indications in prehospital and emergency department settings as indication data are rarely reported.
Data on emergency tourniquet use was analyzed from a large clinical study (NCT00517166 at ClinicalTrials.gov). The study included 728 casualties with 953 limbs with tourniquets. The median casualty age was 26 years (range, 4-70). We compared all other known datasets to this clinical study.
Tourniquet use was prehospital in 671 limbs (70%), hospital only in 104 limbs (11%), and both prehospital and hospital in 169 limbs (18%).Major hemorrhage was observed at or before the hospital in 487 (51%) limbs and minor hemorrhage was observed at the hospital in 463 limbs (49%). Anatomic lesions indicating tourniquets included open fractures (27%), amputations (26%), soft tissue wounds (20%), and vascular wounds (17%). Situations, as opposed to anatomic lesions, indicating tourniquets included bleeding from multiple sites other than limbs (24%), hospital mass casualty situations (1%), one multiple injury casualty needed an airway procedure, and one casualty had an impaled object.
The current indication for emergency tourniquet use is any compressible limb wound that the applier assesses as having possibly lethal hemorrhage. This indication has demonstrated good outcomes only when devices, training, doctrine, evacuation, and research have been optimal. Analysis of emergency tourniquet indications is complex and inadequately evidenced, and further study is prudent. Prehospital data reporting may fill knowledge gaps.
User-centered design of catalog records requires the study of user behaviors and cognition related to interaction with the catalog. During 3 phases of a pilot study, 103 catalog users described 386 ...searches; searchers generally knew the title, publication date, page numbers, and/or the author. (Author/AEF)
This project was the second part of a long-term study into the control of an extractive distillation unit. A fifteen stage extractive distillation column was re-built and operated over a range of ...operating levels. Overhead product acetone composition was limited to approximately 0.94 mole fraction acetone due to tray liquid priming. A steady state simulation was developed to aid in a better understanding of the process. Murphree vapour tray efficiencies were adjusted within the simulation to match experimental and simulated product composition results. The simulation was used to accurately predict unfitted experimental results. Dynamic behaviour of the column was studied by relating product composition responses to changes in disturbance and manipulated variables. Dynamic behaviour was analysed by frequency response and real time response fitting. Experimental data was relatively noisy. First order transfer function models with dead time, fitted in the real time domain, were satisfactory.
Master of Engineering (ME)
The monoclonal antibody, c7E3 Fab, binds to the platelet surface fibrinogen receptor (GPIIb/IIIa), inhibiting platelet aggregation and clot retraction. We performed an in vitro study to assess the ...ability of a modification of the thromboelastograph (MTEG) to detect inhibition of clot strength by c7E3 Fab and its reversal with platelet-rich plasma (PRP). In the modified assay (MTEG), thrombin was added to whole blood (WB) and platelet-poor plasma (PPP) and the resultant maximum amplitude (MA) was measured, MAWB and MAPPP, respectively. Anticoagulated blood samples from 17 patients scheduled for cardiac surgery were collected for a dose response (Part I; n = 5) and c7E3 Fab reversal (Part II; n = 12) study. Clot strength was reduced in a dose-dependent manner by c7E3 Fab. Ecteola cellulose effectively reversed the effect of heparin on the thrombin time and the addition of PRP significantly increased the MAWB (P < 0.0001) and MAWP-PPP (P < 0.0001). Subtracting the MAPPP from MAWB significantly magnified the response of MA to the addition of c7E3 Fab (P = 0.002) and its reversal with PRP (P = 0.005). This in vitro study indicates that the MTEG is a responsive assay demonstrating that inhibition by the antiplatelet c7E3 Fab is reversible with PRP.
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