Search

The integration of hydrothermal carbonisation (HTC) and anaerobic digestion (AD) can overcome some of the disadvantages of thermal or biological processing alone. This study aims to investigate integrated HTC-AD across a range of integration strategies and HTC processing temperatures (150 °C, 200 °C and 250 °C) to improve the energy conversion efficiency (ECE) of grass, compared to AD alone. The separation of hydrochars (HCs) for combustion and process waters (PWs) for digestion appears to be the most energetically feasible HTC-AD integration strategy, compared to HC or HTC-slurry AD. Hydrochars represent the greater energy carrier with between 81–85% of total energy output. The ECE of grass was improved from 51% to 97% (150 °C), 83% (200 °C) and 68% (250 °C) through integrated HTC-AD. Therefore, lower HTC processing temperatures yield more favourable energetics. However, higher HTC temperatures favour more desirable HC properties as a combustion fuel. The hydrochar produced at 250 °C (HC-250) displayed the highest HHV (25.8 MJ/kg) and fixed carbon: volatile matter ratio (0.47), as well as the greatest reduction in slagging and fouling potential (ash flow temperature > 1550 °C). Overall, integrated HTC-AD is an effective energy valorisation strategy for grass. A compromise exists between the quality of hydrochar and the energetic balance. However, at 250 °C the process remains energetically feasible (EROI = 2.63).

Phylogenetic clustering of HIV sequences from a random sample of patients can reveal epidemiological transmission patterns, but interpretation is hampered by limited theoretical support and statistical properties of clustering analysis remain poorly understood. Alternatively, source attribution methods allow fitting of HIV transmission models and thereby quantify aspects of disease transmission.A simulation study was conducted to assess error rates of clustering methods for detecting transmission risk factors. We modeled HIV epidemics among men having sex with men and generated phylogenies comparable to those that can be obtained from HIV surveillance data in the UK. Clustering and source attribution approaches were applied to evaluate their ability to identify patient attributes as transmission risk factors.We find that commonly used methods show a misleading association between cluster size or odds of clustering and covariates that are correlated with time since infection, regardless of their influence on transmission. Clustering methods usually have higher error rates and lower sensitivity than source attribution method for identifying transmission risk factors. But neither methods provide robust estimates of transmission risk ratios. Source attribution method can alleviate drawbacks from phylogenetic clustering but formal population genetic modeling may be required to estimate quantitative transmission risk factors. Keywords: Phylogenetic analysis, Cluster analysis, Phylodynamics, HIV epidemiology, Computer simulation

A basic issue in the physics of behaviour is the mechanical relationship between an animal and its s urroundings. The nematode and model organism C. elegans provides an excellent platform to explore this relationship due to its anatom ical simplicity. Nonetheless , the physics of nematode crawling, in which the worm undulates its body to move on a wet sur face, is not completely understood and the mathematical models often used to describe this phenomenon are empirical . We confirm that linear resistive force theory , one such empirical model, is effective at predicting a worm’s path from its sequence of bod y postures for forward crawling, reversing, and turning and for a broad range of different behavioural phenotypes observed in mutant worms. However, agreement between the predicted and observ ed path is lost when using this model with recently measured val ue s of the drag anisotropy. A recently proposed nonlinear extension of the resistive force theory model also provides accurate predictions, but does not resolve the discrepancy between the parameters required to achieve good path prediction and the experi mentally measured parameters. This means that while we have good effective models of worm crawling that can be used in application s such as whole - animal simulations and advance d tracking algorithms, there are still unanswered questions about the precise n ature of the physical interaction between worms and their most commonly studied laboratory substrate.

Background Between 1990 to 1992 and 1993 to 1995 there was a >5-fold increase (16.7% to 89.8%) in vancomycin-resistant Enterococcus faecium isolates as a percentage of all isolates of vancomycin-resistant enterococci on the pediatric units of The New York Hospital-Cornell Medical Center (NYH-CMC). A molecular epidemiologic investigation was undertaken to determine the extent to which this increase was associated with the spread of a vanA-containing clone of vancomycin-resistant E. faecium that had been previously defined in adults hospitalized at NYH-CMC or with the spread of another vanA clone that had been defined in children hospitalized on the pediatric service at Memorial Sloan-Kettering Cancer Center, which shares a common pediatric intensive care unit and pediatric house staff with NYH-CMC. Methods. Molecular genotyping of vancomycin-resistant E. faecium isolates obtained from pediatric patients from 1993 to 1995 was performed by pulsed field gel electrophoresis of chromosomal SmaI digests. Southern hybridization was performed using vanA- and vanB-specific probes. Medical records of patients were reviewed for pertinent clinical and demographic information. Results. A single vanB clone of vancomycin-resistant E. faecium was responsible for 17 (77.3%) of 22 isolates in the neonatal intensive care unit (NICU) of NYH-CMC. Two other vanB strains of vancomycin-resistant E. faecium and 2 vanA strains were identified among the 5 remaining NICU isolates. Vancomycin-resistant E. faecium isolates from the other pediatric units represented a heterogeneous population of primarily vanA strains, but vanA clonal strains previously identified from patients on adult services at NYH-CMC and from children hospitalized at Memorial Sloan-Kettering Cancer Center were not detected. Conclusion. A newly identified vanB clone was responsible for the increase in vancomycin-resistant E. faecium isolates in the NICU of NYH-CMC. The increase of vancomycin-resistant E. faecium among children hospitalized at NYH-CMC was unrelated to the spread of vancomycin-resistant E. faecium among adults in the same hospital or among children at an affiliated facility cared for by the same house staff and sharing a common pediatric intensive care unit.

The recent literature contains few results of surveys of the social needs of deaf mutes, though several writers stress their importance and make suggestions for meeting them. Thus, Johnson (1948) emphasized the need to help the parents of the deaf child and particularly the importance of parental understan ding and education in the later adjustment of the growing deaf child to his disability. The Scottish Education Department (1950), in dealing with the problem of deaf children, also emphasized the im portance of treating the family as a single unit, and suggested a permanent centre for the guidance of the families of deaf children in assisting the later adjustment of the affected child. Bakwin (1950), reviewing some of the social and psychological prob lems of deaf children in the United States, concluded that the handicap produces no characteristic person ality distortion, and emphasizes the importance of parental attitude in adjustment; she referred to the dangers as well as the advantages of institutional treatment and suggested that being sent to an institu tion may make the deaf child feel rejected. Pintner and Brunschwig (1946) drew attention to the diffi culties of adjustment of the deaf child, particularly where there are no other deaf relatives. Simon (1948) mentioned the ill effects on the deaf mute of his exclu sion from normal responsibilities. Martens (1936) surveyed the work history of over 10,000 deaf persons who had received occupational training in school; his results showed that success in employment was not related to the amount of vocational training received. Methods

In order to determine whether tuberculosis is associated with elevated levels of soluble interleukin-2 receptors (SIL-2R), patients with both pulmonary (n = 12) and extrapulmonary (n = 8) disease were studied. SIL-2R were measured in sera using an enzyme-linked immunosorbent assay (ELISA). Prior to treatment, all 20 patients had levels of SIL-2R significantly greater than those of the 14 control subjects. Longitudinal study of patients with pulmonary disease revealed that levels of SIL-2R remained elevated in 11 of 12 patients after 2 months, and in four of six patients after 3 months of treatment. These findings suggest that tuberculosis is characterized by prolonged activation of the immune system despite optimal chemotherapy and that SIL-2R may distinguish active immunity from immunologic memory to this infection.