458 research outputs found
Four Logics and a Protocol
The Internet Protocol (IP) is the protocol used to provide connectionless communication between hosts connected to the Internet. It provides a basic internetworking service to transport protocols such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). These in turn provide both connection-oriented and connectionless services to applications such as file transfer (FTP) and WWW browsing. In this paper we present four separate specifications of the interface to the internetworking layer implemented by IP using four types of logic: classical, constructive, temporal and linear logic
Draft genome sequence of Lactobacillus crispatus EM-LC1, an isolate with antimicrobial activity cultured from an elderly subject
Here we report the 1.86-Mb draft genome sequence of Lactobacillus crispatus EM-LC1, a fecal isolate with antimicrobial activity. This genome sequence is expected to provide insights into the antimicrobial activity of L. crispatus and improve our knowledge of its potential probiotic traits
Gravitational Geons Revisited
A careful analysis of the gravitational geon solution found by Brill and
Hartle is made. The gravitational wave expansion they used is shown to be
consistent and to result in a gauge invariant wave equation. It also results in
a gauge invariant effective stress-energy tensor for the gravitational waves
provided that a generalized definition of a gauge transformation is used. To
leading order this gauge transformation is the same as the usual one for
gravitational waves. It is shown that the geon solution is a self-consistent
solution to Einstein's equations and that, to leading order, the equations
describing the geometry of the gravitational geon are identical to those
derived by Wheeler for the electromagnetic geon. An appendix provides an
existence proof for geon solutions to these equations.Comment: 18 pages, ReVTeX. To appear in Physical Review D. Significant changes
include more details in the derivations of certain key equations and the
addition of an appendix containing a proof of the existence of a geon
solution to the equations derived by Wheeler. Also a reference has been added
and various minor changes have been mad
Predictors of death without prior appropriate therapy in ICD recipients: the comorbidities, frailty and functional status (COMFFORT study)
Objective: Most patients who have an implantable cardioverter-defibrillator (ICD) implant do not receive life-prolonging therapy from it. Little research has been undertaken to determine which patients benefit the least from ICD therapy. As patients age and accumulate comorbidities, the risk of death increases and the benefit of ICDs diminishes. We sought to evaluate the impact of comorbidity, frailty, functional status on death with no prior appropriate ICD therapy. Methods: A prospective, multicentre, observational study involving 12 English hospitals was undertaken. Patients were eligible for inclusion for the study if they were scheduled to have a de novo, upgrade to or replacement of a transvenous or subcutaneous ICD or cardiac resynchronisation therapy device and defibrillator (CRT-D). Baseline characteristics were collected. Participants were asked to complete a frailty assessment (Fried score) and a functional status questionnaire (EuroQol 5-Dimension 5-Level (EQ-5D-5L)). The Charlson Comorbidity Index was calculated. Patients were prospectively followed up for 2.5 years. The primary outcome was death with no prior appropriate therapy. Results: In total, 675 patients were enrolled, mean age 65.7 (IQR 65–75) years. A total of 63 patients (9.5%) died during follow-up, 58 without receiving appropriate ICD therapy. Frailty was present in 86/675 (12.7%) and severe comorbidity in 69/675 (10.2%). Multivariate predictors of death with no appropriate therapy were identified and a risk score comprising frailty, comorbidity, increasing age, estimated glomerular filtration rate and EQ-5D-5L was developed. Conclusion: Comorbidities, frailty and the EQ-5D-5L score are powerful, independent predictors of death with no prior appropriate therapy in ICD/CRT-D recipients
Predictors of death without prior appropriate therapy in ICD recipients: the comorbidities, frailty and functional status (COMFFORT study)
Objective: Most patients who have an implantable cardioverter-defibrillator (ICD) implant do not receive life-prolonging therapy from it. Little research has been undertaken to determine which patients benefit the least from ICD therapy. As patients age and accumulate comorbidities, the risk of death increases and the benefit of ICDs diminishes. We sought to evaluate the impact of comorbidity, frailty, functional status on death with no prior appropriate ICD therapy. Methods: A prospective, multicentre, observational study involving 12 English hospitals was undertaken. Patients were eligible for inclusion for the study if they were scheduled to have a de novo, upgrade to or replacement of a transvenous or subcutaneous ICD or cardiac resynchronisation therapy device and defibrillator (CRT-D). Baseline characteristics were collected. Participants were asked to complete a frailty assessment (Fried score) and a functional status questionnaire (EuroQol 5-Dimension 5-Level (EQ-5D-5L)). The Charlson Comorbidity Index was calculated. Patients were prospectively followed up for 2.5 years. The primary outcome was death with no prior appropriate therapy. Results: In total, 675 patients were enrolled, mean age 65.7 (IQR 65–75) years. A total of 63 patients (9.5%) died during follow-up, 58 without receiving appropriate ICD therapy. Frailty was present in 86/675 (12.7%) and severe comorbidity in 69/675 (10.2%). Multivariate predictors of death with no appropriate therapy were identified and a risk score comprising frailty, comorbidity, increasing age, estimated glomerular filtration rate and EQ-5D-5L was developed. Conclusion: Comorbidities, frailty and the EQ-5D-5L score are powerful, independent predictors of death with no prior appropriate therapy in ICD/CRT-D recipients
Childhood tetanus in Australia: ethical issues for a should-be-forgotten preventable disease
Refusal of a parent to have a child vaccinated against tetanus raised ethical issues for the treating clinicians.
The clinicians felt their duty to the child was compromised, but recognised that our society leaves the authority for such decisions with the parents.
As there was no reason, other than different beliefs about vaccination, to doubt the parent\u27s care for the child, the clinicians limited their response to providing strong recommendations in favour of vaccination.
Other issues raised by this case include community protection, and the costs to the community of treating a vaccine-preventable disease
Protective Immunity against Respiratory Syncytial Virus in Early Life after Murine Maternal or Neonatal Vaccination with the Recombinant G Fusion Protein BBG2Na
Maternal and neonatal immunization were evaluated for their capacity to induce protective immunity against respiratory syncytial virus (RSV) lower respiratory tract infections in early life. Murine models were studied by use of a novel recombinant vaccine candidate, designated BBG2Na, which was derived in part from the RSV (Long) G protein. Maternal immunization resulted in the passive transfer of high levels of RSV-A antibodies to the offspring, which protected them from RSV challenge for up to 14 weeks. Indeed, protection correlated with the detection of RSV antibodies in the serum. Neonatal immunization with BBG2Na induced significant antibody responses even in the first week of life. Most importantly, these neonatal responses were not inhibited by the presence of RSV maternal antibodies. Consequently, the combination of maternal and neonatal immunization with BBG2Na resulted in the continual presence of protective levels of antibodies in the offsprin
Protective Efficacy against Respiratory Syncytial Virus following Murine Neonatal Immunization with BBG2Na Vaccine: Influence of Adjuvants and Maternal Antibodies
Alum-adsorbed BBG2Na, a recombinant vaccine derived in part from the respiratory syncytial virus (RSV) subgroup A G protein, induced moderate antibody titers after 1 immunization in 1-week-old mice but conferred complete lung protection upon RSV challenge. The anti-BBG2Na IgG1-IgG2a neonatal isotype profile was suggestive of dominant Th2 responses compared with those in adults. Formulation of BBG2Na with a Th1-driving adjuvant efficiently shifted neonatal responses toward a more balanced and adultlike IgG1-IgG2a profile without compromising its protective efficacy. BBG2Na-induced protective immunity was maintained even after early life immunization in the presence of high titers of maternal antibodies. Under these conditions, the protective efficacy (86%-100%) reflected the high capacity of the nonglycosylated G2Na immunogen to escape inhibition by RSV-A—induced maternal antibodies. Thus, immunization with BBG2Na protected against viral challenge despite neonatal immunologic immaturity and the presence of maternal antibodies, two major obstacles to neonatal RSV vaccine developmen
Nectar chemistry modulates the impact of an invasive plant on native pollinators
1. Invasive species are considered a main driver of pollinator declines, yet the direct effects of invasive alien plants on pollinators are poorly understood.
2. Abundant, invasive plant species can provide a copious nectar resource for native pollinators. However, the nectar of some plants contains secondary compounds, usually associated with defence against herbivores. The impacts of these compounds on pollinators are often unknown.
3. We compared how consumption of grayanotoxin I and III, natural secondary compounds in the nectar of invasive Rhododendron ponticum L., affected three native bee species: a honeybee, (Apis mellifera L.), a solitary mining bee (Andrena carantonica, Pérez) and a bumblebee, (Bombus terrestris, L.).
4. Survival of the solitary bee and the bumblebee species was not affected by either grayanotoxin, but honeybees were ∼20× more likely to die when fed solutions containing grayanotoxin I. Furthermore, solitary bees were deterred from feeding and exhibited malaise behaviours indicative of sublethal toxicity in response to consumption of grayanotoxin I. In contrast, grayanotoxins did not affect bumblebee survival or behaviour, even when bees were subjected to multiple stressors (parasite infection or food stress).
5. Our experiments suggest that while R. ponticum provides abundant floral nectar, it is only available as a food resource to pollinators that tolerate grayanotoxins. Pollinators whose health is negatively affected by grayanotoxins may experience negative impacts from R. ponticum invasion directly (if they consume R. ponticum nectar) or indirectly (if native floral resources are replaced by R. ponticum).
6. Our study makes a novel comparison of the effects of a natural nectar secondary compound on three pollinator species and clearly demonstrates drastic variation in the responses of different key pollinator taxa to a nectar toxin. Our findings are thus in congruence with literature demonstrating the varying effects of invasive plant chemistry on native foliar herbivores, and our work demonstrates that nectar chemistry should be taken into account when determining the impacts of plant invasion for native pollinators
Development of a synthetic phantom for the selection of optimal scanning parameters in CAD-CT colonography
The aim of this paper is to present the development of a synthetic phantom that can be used for the selection of optimal scanning parameters in computed tomography (CT) colonography. In this paper we attempt to evaluate the influence of the main scanning parameters including slice thickness, reconstruction interval, field of view, table speed and radiation dose on the overall performance of a computer aided detection (CAD)–CTC system. From these parameters the radiation dose received a special attention, as the major problem associated with CTC is the patient exposure to significant levels of ionising radiation. To examine the influence of the scanning parameters we performed 51 CT scans where the spread of scanning parameters was divided into seven different protocols. A large number of experimental tests were performed and the results analysed. The results show that automatic polyp detection is feasible even in cases when the CAD–CTC system was applied to low dose CT data acquired with the following protocol: 13 mAs/rotation with collimation of 1.5 mm × 16 mm, slice thickness of 3.0 mm, reconstruction interval of 1.5 mm, table speed of 30 mm per rotation. The CT phantom data acquired using this protocol was analysed by an automated CAD–CTC system and the experimental results indicate that our system identified all clinically significant polyps (i.e. larger than 5 mm)
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