Miracle-dz/UniFAR-FTUs huggingface dataset:
Rat Pneumonia and Soft-Tissue Infection Models for the Study of Acinetobacter baumannii Biology

ABSTRACT Acinetobacter baumannii is a bacterial pathogen of increasing medical importance. Little is known about its mechanisms of pathogenesis, and safe reliable agents with predictable activity against A. baumannii are presently nonexistent. The availability of relevant animal infection models will facilitate the study of Acinetobacter biology. In this report we tested the hypothesis that the rat pneumonia and soft-tissue infection models that our laboratory had previously used for studies of extraintestinal pathogenic Escherichia coli were clinically relevant for A. baumannii. Advantages of these models over previously described models were that the animals were not rendered neutropenic and they did not receive porcine mucin with bacterial challenge. Using the A. baumannii model pathogen 307-0294 as the challenge pathogen, the pneumonia model demonstrated all of the features of infection that are critical for a clinically relevant model: namely, bacterial growth/clearance, an ensuing host inflammatory response, acute lung injury, and, following progressive bacterial proliferation, death due to respiratory failure. We were also able to demonstrate growth of 307-0294 in the soft-tissue infection model. Next we tested the hypothesis that the soft-tissue infection model could be used to discriminate between the inherent differences in virulence of various A. baumannii clinical isolates. The ability of A. baumannii to grow and/or be cleared in this model was dependent on the challenge strain. We also hypothesized that complement is an important host factor in protecting against A. baumannii infection in vivo. In support of this hypothesis was the observation that the serum sensitivity of various A. baumannii clinical isolates in vitro roughly paralleled their growth/clearance in the soft-tissue infection model in vivo. Lastly we hypothesized that the soft-tissue infection model would serve as an efficient screening mechanism for identifying gene essentiality for drug discovery. Random mutants of 307-0294 were initially screened for lack of growth in human ascites in vitro. Selected mutants were subsequently used for challenge in the soft-tissue infection model to determine if the disrupted gene was essential for growth in vivo. Using this approach, we have been able to successfully identify a number of genes essential for the growth of 307-0294 in vivo. In summary, these models are clinically relevant and can be used to study the innate virulence of various Acinetobacter clinical isolates and to assess potential virulence factors, vaccine candidates, and drug targets in vivo and can be used for pharmacokinetic and chemotherapeutic investigations.
Scale Dependency of Rarity, Extinction Risk, and Conservation Priority

Abstract: In developing red data books of threatened species, the World Conservation Union uses measures of rarity, rates of decline, and population fragmentation to categorize species according to their risk of extinction. However, most quantitative measures of these three concepts are sensitive to the scale at which they are made. In particular, definitions of rarity based on an area‐of‐occupancy threshold can nearly always be met if area of occupancy is calculated from a sufficiently fine‐scale (high‐resolution) grid. Recommendations for dealing with scale dependency include (1) choosing a standard scale of measurement, (2) using multiple scales of measurement, and (3) developing indices that combine information from multiple scales. As an example of the second and third approach, the construction of a species' scale‐area curve represents a unifying method for quantifying all three indicators of extinction risk—rarity, rate of decline, and population fragmentation—as functions of area of occupancy and measurement scale. A multiscale analysis is also of practical importance because measurements made at different scales are relevant to different extinction processes. Coarse‐scale measures of rarity are most appropriate when threat is assessed on the basis of spatially autocorrelated events of a large extent, such as global climate change, whereas fine‐scale measures may best predict extinction risk due to local processes such as demographic stochasticity. We illustrate our arguments with a case study of the British distributions of two related plant species that show a 200‐fold reversal in their relative rarity when measured at different scales.
Intramuscular triacylglycerol, glycogen and acetyl group metabolism during 4 h of moderate exercise in man

This study investigated intramuscular triacylglycerol (IMTG) and glycogen utilisation, pyruvate dehydrogenase activation (PDHa) and acetyl group accumulation during prolonged moderate intensity exercise. Seven endurance‐trained men cycled for 240 min at 57 % maximal oxygen consumption (V̇O2,max) and duplicate muscle samples were obtained at rest and at 10, 120 and 240 min of exercise. We hypothesised that IMTG utilisation would be augmented during 2‐4 h of exercise, while PDHa would be decreased secondary to reduced glycogen metabolism. IMTG was measured on both muscle samples at each time point and the coefficient of variation was 12.3 ± 9.4 %. Whole body respiratory exchange ratio (RER) decreased from 0.89 ± 0.01 at 30 min to 0.83 ± 0.01 at 150 min and remained low throughout exercise. Plasma glycerol and free fatty acids (FFAs) had increased compared with rest at 90 min and progressively increased until exercise cessation. Although plasma glucose tended to decrease with exercise, this was not significant. IMTG was reduced at 120 min compared with rest (0 min, 15.6 ± 0.8 mmol kg−1 d.m.; 120 min, 12.8 ± 0.7 mmol kg−1 d.m.) but no further reduction in IMTG was observed at 240 min. Muscle glycogen was 468 ± 49 mmol kg−1 d.m. at rest and decreased at 120 min and again at 240 min (217 ± 48 and 144 + 47 mmol kg−1 d.m.). PDHa increased above rest at 10 and 120 min, but decreased at 240 min, which coincided with reduced whole body carbohydrate oxidation. Muscle pyruvate and ATP were unchanged with exercise. Acetyl CoA increased at 10 min and remained elevated throughout exercise. Acetylcarnitine increased at exercise onset but returned to resting values by 240 min. Contrary to our first hypothesis, significant utilisation of IMTG occurred during the first 2 h of moderate exercise but not during hours 2‐4. The reduced utilisation of intramuscular fuels during the last 120 min was offset by greater FFA delivery and oxidation. Consistent with the second hypothesis, PDHa decreased late in moderate exercise and closely matched the estimates of lower carbohydrate flux. Although the factor underlying the PDHa decrease was not apparent, reduced pyruvate provision secondary to diminished glycolytic flux is the most likely mechanism.
Postoperative respiratory disorders

Purpose of reviewPostoperative pulmonary complications (PPC) are a prominent determinant of postoperative morbidity, mortality, and increased use of healthcare resources. Several scores have been developed to identify patients at higher risk of PPC and have been proposed or validated as tools to predict postoperative respiratory disorders, stratify risk among patients requiring surgery, and to plan clinical studies. The aim of this review is to provide an update on the recent progresses in perioperative medicine concerning the risk assessment, prevention, and treatment of PPCs. Recent findingsEfforts are being made to develop a uniform definition of PPCs; several scores have been developed and some of them externally validated. Their use can help the clinician to identify patients at higher risk, develop tailored strategies to mitigate the risk, and to perform a thoughtful allocation of healthcare resources. Intraoperative protective ventilation, with low tidal volume, low plateau pressure, low driving pressure and positive end expiratory pressure set at low-moderate levels titrated to avoid an increase in driving pressure and to achieve an acceptable gas exchange, can reduce the incidence of PPCs. Noninvasive positive pressure ventilation has an important role in the treatment of early stages of postoperative respiratory impairment, whereas not enough evidence is available concerning the use of routine prophylactic noninvasive continuous positive airway pressure postoperatively. SummarySeveral strategies can improve patients’ outcome, including risk assessment, intraoperative protective ventilation and postoperative noninvasive ventilation.
The Efficacy, Side Effects, and Recovery Characteristics of Dexmedetomidine Versus Propofol When Used for Intraoperative Sedation

We evaluated the cardio-respiratory effects of equi-sedative doses of dexmedetomidine and propofol for intraoperative sedation. Secondary comparison end points were time to achieve and terminate sedation and postoperative analgesia and psychomotor performance. Forty patients scheduled for elective surgery provided informed consent and were randomized equally to receive either dexmedetomidine (1 &mgr;g/kg initial loading dose for 10 min; maintenance, 0.4–0.7 &mgr;g · kg−1 · h−1) or propofol (75 &mgr;g · kg−1 · min−1 × 10 min; maintenance, 12.5–75 &mgr;g · kg−1 · min−1). Hemodynamic variables (heart rate and mean arterial blood pressure), sedation (visual analog scale and Observer Assessment of Alertness/Sedation), bispectral index score of sedation, ventilation (respiratory rate, O2 sat, and ETco2), psychomotor performance (digital symbol substitution test), and pain (visual analog scale) were determined during surgery and up to 95 min after surgery. Intraoperative sedation levels were targeted to achieve a bispectral index score of 70–80. Patient demographics, ASA class, surgical procedure, and baseline cardio-respiratory variables were similar between groups. Sedation was achieved more rapidly with propofol but was similar between groups 25 min after initiating infusions. The average infusion rate for dexmedetomidine was 0.7 &mgr;g · kg−1 · h−1 and 38 &mgr;g · kg−1 · min−1 for propofol. There were no differences between groups in psychomotor performance and respiratory rate during recovery. The previous use of dexmedetomidine resulted in more sedation, lower blood pressure, and improved analgesia (less morphine use) in recovery.
Global finite-time stabilization via output-feedback for a class of stochastic nonlinear systems

In this paper, the problem of finite-time stabilization via output-feedback is investigated for a class of continuous but non-smooth stochastic nonlinear systems. In order to deal with the Itô correction terms, we apply a rescaling transformation for the stochastic nonlinear systems. By extending the adding-a-power-integrator technique and a new observer design, we design an output-feedback controller to guarantee that the equilibrium of the closed-loop system is globally finite-time stable in probability. A numerical simulation example is given to illustrate the effectiveness of the proposed approach.
High sensitivity C-reactive protein, NT-proBNP and hemodynamic left ventricular function in acute coronary syndrome without ST segment elevation - a preliminary report.

BACKGROUND Prognostic factors in acute coronary syndromes have been the subject of interest in cardiology over the last few years. Our study aimed to compare humoral marker concentration shifts (hsCRP, Nt-proBNP) and hemodynamic left ventricular systolic function index changes, determined by means of echocardiography in the first hours of acute coronary syndromes (ACS). MATERIAL/METHODS The study comprised 33 patients with ACS without ST segment elevation. Group I consisted of 18 patients (11 men, 7 women aged from 48 to 77, mean age 67+/-35 years) with unstable angina pectoris (uAP). Group II consisted of 15 patients (10 men, 5 women aged from 51 to 80, mean age 70+/-11.9 years) with myocardial infarction without ST segment elevation (NSTEMI). In all patients, Nt-proBNP and hsCRP blood concentrations were determined between the 6th and 12th hours after admission to the intensive coronary care unit. On the 2nd-3rd day, after coronary stabilization, routine echocardiography was performed in each patient to assess left ventricular function. RESULTS A positive correlation between hsCRP and Nt-proBNP in uAP was observed in group I. In group II, in patients with NSTEMI no such correlation was observed. There was also no correlation in either study group between humoral (hsCRP and Nt-proBNP) and hemodynamic parameters. CONCLUSIONS The complex evaluation of the post-ACS prognosis should be multifaceted. It should contain hemodynamic assessment of the left ventricle by means of echocardiography as well as humoral coronary risk markers.
Chronic Stress and Immunosenescence: A Review

This paper reviews recent work suggesting that human immunosenescence may be closely related to both chronic stress and stress hormones. The age-related immunological changes are also similarly found during chronic stress or glucocorticoid exposure. These data further suggest that endogenous glucocorticoids could be associated with immunosenescence. When compared with young subjects, healthy elders are emotionally distressed in parallel to increased cortisol/dehydroepiandrosterone ratio. Furthermore, chronically stressed elderly subjects may be particularly at risk of stress-related pathology because of further alterations in glucocorticoid-immune signaling. Age-related increase in cortisol/dehydroepiandrosterone ratio could be understood as a major determinant of immunological changes observed during aging. Strictly healthy elders are somewhat protected from chronic stress exposure and show normal cortisol levels and increased T cell function. This information adds a new key dimension to the biology of aging and stress.
Tissue transglutaminase contributes to disease progression in the R6/2 Huntington's disease mouse model via aggregate‐independent mechanisms

Huntington's disease (HD) is caused by an expansion of CAG repeats within the huntingtin gene and is characterized by intraneuronal mutant huntingtin protein aggregates. In order to determine the role of tissue transglutaminase (tTG) in HD aggregate formation and disease progression, we cross‐bred the R6/2 HD mouse model with a tTG knockout mouse line. R6/2 mice that were tTG heterozygous knockouts (R6/2 : tTG+/–) and tTG homozygous knockouts (R6/2 : tTG–/–) showed a very similar increase in aggregate number within the striatum compared with R6/2 mice that were wild‐type with respect to tTG (R6/2 : tTG+/+). Interestingly, a significant delay in the onset of motor dysfunction and death occurred in R6/2 : tTG–/– mice compared with both R6/2 : tTG+/+ and R6/2 : tTG+/– mice. As aggregate number was similarly increased in the striatum of both R6/2 : tTG+/– and R6/2 : tTG–/– mice, whereas only R6/2 : tTG–/– mice showed delayed disease progression, these data suggest that the contribution of tTG towards motor dysfunction and death in the R6/2 mouse is independent of its ability to negatively regulate aggregate formation. Moreover, the combined results from this study suggest that the formation of striatal huntingtin aggregates does not directly influence motor dysfunction or death in this HD mouse model.
Vancomycin resistant coagulase-negative Staphylococcal isolates from HIV positive patients in the Limpopo Province, South Africa

Coagulase-negative staphylococci (CNS) are a major cause of nosocomial infection, especially in critically ill and immunocompromised patients. CNS is usually a multi-drug resistant and glycopeptide antibiotics that have been considered to date, the drug of choice for treatment. The aim of this study was to characterize CNS with reduced susceptibility to glycopeptides isolated from the respiratory tract of HIV positive patients from the Limpopo Province in South Africa between 2007 and November 2008. A total of 185 sputum samples were collected from HIV positive drug naive patients and analyzed for antibiotics resistant profiles of the coagulase-negative staphylococci isolates. The isolates were tested for susceptibility to extracts from five medicinal plants commonly used in the Venda region of Limpopo Province. Of a total of 185 sputum samples investigated, 88 were positive for CNS and all of this displayed reduced susceptibility to glycopeptides. Species distribution was as follows: Staphylococcus auricularis(5), Staphylococcus capitis (6), Staphylococcus hominis (23), Staphylococcus epidermidis(36) and Staphylococcus saprophyticus (18). The incidence of oxacillin, linezolid, daptomycin, imipenem and meropenem resistance was 100%. Evaluation of plant extracts against representative of the isolates showed all the extracts from the bark of medicinal plants to have inhibitory effect on their growth. There is high prevalence of vancomycin resistant CNS among HIV positive patients who participated in this study. This prevalence is quite alarming as this is the only drug of choice since methicillin resistance among this group of organisms is equally quite common. The plant extracts demonstrated antibacterial activity as they inhibited the growth of the isolates they were tested for. Surveillance by anti-biotyping with attention to multi-resistant profile, and warning to clinicians, is necessary. Similarly, further investigation is needed to identify the chemical composition of the active antibacterial compounds in the plant extracts. Key words: Coagulase-negative staphylococci, vancomycin, antibiotic resistance, plant extracts, HIV
Patients' beliefs about the causes of heart disease: relationships with risk factors, sex and socio-economic status

Background Patients' beliefs about the causes of their heart disease (causal attributions) are important to effective medical communication, psychological adaptation, and adherence to advice. We assessed the extent to which causal attributions relate to risk factors, sex and socio-economic status in men and women diagnosed with acute coronary syndrome. Design We conducted an interview and questionnaire study of 171 acute coronary syndrome patients assessed within 5 days of admission to three hospitals in the London area. Method Patients rated beliefs in the role of 16 factors in causing their heart disease. Associations between attributions and risk factors were assessed, and differences in beliefs by sex and socio-economic status (defined by educational attainment) analysed. Results The most common attributions were to stress, smoking, high blood pressure, chance or bad luck, and heredity. Attributions were strongly associated with risk factors: 90% of smokers attributed heart disease to smoking, compared with 0% never smokers; 90.4% of hypertensives attributed heart disease to high blood pressure, 72.2% of patients with a positive family history to heredity, 85% of obese patients to being overweight, and 49% of sedentary patients to lack of exercise. Attributions to stress were related both to current mood and reports of recent life stress. There were few sex differences, but higher socio-economic status patients were more likely to attribute heart disease to heredity and genetic factors. Conclusions Causal beliefs about heart disease are strongly associated with risk factors. Effective communication about modifiable risk factors may influence causal beliefs and stimulate lifestyle change, thereby promoting secondary prevention.
Phonon relaxation rates in silicon thin films determined by molecular dynamics

Silicon thin films with nanometer dimensions are increasingly being used in the electronic and nanotechnology industries. At such small scales, the continuum assumption is no longer valid and the interactions of the energy carriers (phonons) with the boundaries affect the thermal conductivity of the films. For semiconductors and dielectric thin films, understanding phonon properties in the nanometer scale is important not only to predict their thermal transport behavior, but also to propose solutions to a broad range of thermally induced problems, such as self-heating, sub-continuum localized heating effects and thermally induced reliability. In this work, we estimate, by means of molecular dynamics, the phonon relaxation times in silicon thin films, in the out-of-plane direction, at different temperatures and thin film thicknesses. The relaxation times are determined from the temporal decay of the autocorrelation function of the energy components of the phonons allowed in the crystal. The results are compared with the relaxation times obtained from perturbation theory and Mathiessen's rule. Two major trends were observed, the relaxation rates for transversal acoustic modes are lower than those for the longitudinal acoustic mode for all thickness and temperatures studied, and the longitudinal acoustic modes do not follow the theoretical predictions
Randomized cyclic delay code for cooperative communication systems

We deal here with distributed cooperative communication systems in which a single source transmits its information with the help of multiple relays to a destination. Specifically, we consider decode and forward relay networks based on orthogonal frequency division multiplexing (OFDM). Most previous work needs a priori information for antenna allocation to obtain cooperative diversity advantages. We propose a simple method that does not require additional information in order to coordinate relay transmission. Our main proposal is to retransmit randomly cyclic-shifted sequences of the received symbol at relays. Simulation results verify that full gain in diversity is achieved when the number of subcarriers is sufficiently large.
Challenges of Model Interoperation in Military Simulations

The need for interoperability between different military simulation systems is growing fast, as the complexity of modern war fighting rises above the handling capacity of monolithic models. The development of consistent model federations has therefore become as important as the development of new (interoperable) models. However, complex military simulation systems belong to the class of model-based information systems, and the paramount aspects of such information systems are abstraction and idealization from reality. Experiments with the high-resolution combat simulation system, COSIMAC, and some modules implementing basic command and control functionality have shown that there are pressing challenges for coupling model-based information systems above the currently manageable levels. The results of this contribution indicate that technical, syntactic, and obvious semantic (lexicographic) coupling preconditions are not sufficient to guarantee a successful interaction.