Minimal group presentations : a computational approach

The method of describing a group by means of generators and relations is an old one. A question which arises when using this method is what is the minimum number of relations required to describe a given group. Schur (1907) provided a lower bound for the number of relations required, in terms of a group invariant known as the Schur multiplicator. It would be interesting to know which finite groups have a presentation achieving the Schur bound on the number of relations required, but this remains an open question. It is known that the Schur bound is not achievable for some finite groups. We consider the problem of finding a minimal presentations for a number of finite groups. In Chapter Three and Appendix A we give minimal presentations for the groups of order less than or equal to 84 and minimal presentations for some families of groups having composition length less than five and order greater than 84. Some of the techniques for working with finitely presented groups are illustrated by proving that the groups defined by some families of deficiency zero presentations are finite. In Chapter Four, we give presentations for several finite groups having soluble length five and six, and deficiency zero presentations for two infinite families of finite groups, one family having soluble length six, and the other having soluble length five; we also give a deficiency one presentation for a finite preimage of a group having soluble length seven. Finally, in Chapter Five we give some minimal presentations for some quasi-simple groups

Influence of Nitrogen Sources and Plant Growth-Promoting Rhizobacteria Inoculation on Growth, Crude Fiber and Nutrient Uptake in Squash (Cucurbita moschata Duchesne ex Poir.) Plants

Plant growth promoting rhizobacteria (PGPR, B) have immense potential application in sustainable agriculture as ecofriendly biofertilizers and biopesticides. In this study, the effects of three nitrogen (N) sources (NO3-, NH4+ and NO3NH4) and PGPR on growth, crude fiber and nutrient uptake were investigated in squash plants. Some growth parameters [root dry weight (RDW), shoot dry weight (SDW), total plant dry weight (PDW), number of leaves (NL), shoot length (SL), stem diameter (SD) and number of ramifications (NR)], crude fiber (cellulose content) and nutrient uptake (N, P, K, Ca, Mg, Na, Fe, Cu, Mn and Zn) were determined. Application of NO3-, NH4+ or NO3NH4 singly or in combination with PGPR inoculation led to a significant increase in RDW, SDW, PDW, NL, SL, SD and NR. Na, Cu and Zn contents, on the contrary, decreased in inoculated treated plants while no significant differences were recorded in cellulose contents (CE) of leaves except in plants fed with NO3-. The leaf CE content ranged from 12.58 to 13.67%. The plants supplied with NO3+B, NH4+B and NO3NH4+B showed significantly higher plant biomass and accumulation of N, P, K and Mn concentrations in leaves compared to all other treatments. These results suggest that specific combinations of PGPR with NO3-, NH4+ or NO3NH4 fertilizers can be considered as efficient alternative biofertilizers to improve significantly the squash growth and nutrient uptake

The impact of disease progression on perceived health status and quality of life of long-term cancer survivors

Introduction The number of cancer survivors experiencing disease progression (DP) is increasing with the number of cancer survivors. However, little is known whether DP affects health-related quality of life (HRQL) of long-term cancer survivors. We aimed therefore to compare the health status (HS) and HRQL of DP and disease-free (DF) survivors up to 15 years after initial diagnosis. Methods 232 cancer survivors with DP identified through the Eindhoven Cancer Registry were matched with 232 DF survivors of similar demographic and clinical characteristics. Patients completed generic HS (SF-36) and cancer-specific HRQL (QOL-CS) questionnaires 5-15 years after diagnosis. Results Compared with DF survivors, DP survivors exhibited significantly lower scores on all SF-36 and QOL-CS (except spiritual well-being) dimensions. DF survivors had better scores than the normative population on all SF-36 dimensions. Among survivors with DP, those with short survival (<5 years) had significantly poorer HS scores on all dimensions except bodily pain compared with the normative population. Comparatively, the long survival (≥5 years) DP group had better HRQL than the short DP group but poorer HRQL than the normative population. In multivariate analyses, DP and DF survival time were independently associated with aspects of HS and HRQL in cancer survivors. Discussions/Conclusions DP cancer survivors have poorer long-term HS and HRQL compared with DF survivors. However, there is suggestion that HS and HRQL does improve over time following DP. Implication for Cancer Survivors Although DP survivors report poorer long-term HRQL compared with DF cancer survivors, results suggest that time can attenuate the distress of DP on HRQL. Psycho-educational programs could help to increase patients' sense of empowerment and personal control should DP occur

Telemonitoring Devices and Systems: Current Status and Future Trends

In the future, the number of elderly and chronically ill will be quite large. Additionally, pathologies will in many cases be in comorbidity. Alongside this reality, the health care resources will be insufficient for the population, thus the current research for solutions that can be fully implemented in the future. There are available several telemonitoring devices and systems for chronic diseases. Massive use of these devices will be essential to address the current and future lack of health system resources. Research on telemonitoring devices and systems for chronic diseases was con-ducted in academic and scientific databases. The technical specifications were collected in the manufacturers’ web page. The gathered data was analysed and compared in order to propose scenarios for the future trend of technical specifi-cations required in telemonitoring devices/system is performed. Telemonitoring for chronic diseases can bring great benefits to patient and health systems. Widening this practice will be a reality in the near future. This procedure will be fostered by the promotion and regulation of interoperability between de-vices/systems, as well as of front-end programs providing the link between health support systems. Interoperability issues are the main flaw of tedevicesring devices/systems on the market today.info:eu-repo/semantics/publishedVersio

Telemonitoring Devices and Systems: Current Status and Future Trends

In the future, the number of elderly and chronically ill will be quite large. Additionally, pathologies will in many cases be in comorbidity. Along with this reality, the health care resources will be insufficient for the population, thus the current research for technological solutions needs to be implemented in the future. There are available several telemonitoring devices and systems for chronic diseases. Massive use of these devices will be essential to address the current and future lack of health system resources. Research on telemonitoring devices and systems for chronic diseases was conducted in academic and scientific databases. The technical specifications were collected from the manufacturers’ web page. The collected data was analysed and compared in order to propose scenarios for the future trend of technical specifications required in telemonitoring devices/system. Telemonitoring for chronic diseases can bring great benefits to patient and health systems. Widening this practice will be a reality in the near future. This procedure will be fostered by the promotion and regulation of interoperability between devices/systems, as well as of front-end programs providing the link between health support systems. Interoperability issues are the main flaws of telemonitoring devices/systems on the market today.info:eu-repo/semantics/publishedVersio

Fine Mapping the Spatial Distribution and Concentration of Unlabeled Drugs within Tissue Micro-Compartments Using Imaging Mass Spectrometry

Readouts that define the physiological distributions of drugs in tissues are an unmet challenge and at best imprecise, but are needed in order to understand both the pharmacokinetic and pharmacodynamic properties associated with efficacy. Here we demonstrate that it is feasible to follow the in vivo transport of unlabeled drugs within specific organ and tissue compartments on a platform that applies MALDI imaging mass spectrometry to tissue sections characterized with high definition histology. We have tracked and quantified the distribution of an inhaled reference compound, tiotropium, within the lungs of dosed rats, using systematic point by point MS and MS/MS sampling at 200 µm intervals. By comparing drug ion distribution patterns in adjacent tissue sections, we observed that within 15 min following exposure, tiotropium parent MS ions (mass-to-charge; m/z 392.1) and fragmented daughter MS/MS ions (m/z 170.1 and 152.1) were dispersed in a concentration gradient (80 fmol-5 pmol) away from the central airways into the lung parenchyma and pleura. These drug levels agreed well with amounts detected in lung compartments by chemical extraction. Moreover, the simultaneous global definition of molecular ion signatures localized within 2-D tissue space provides accurate assignment of ion identities within histological landmarks, providing context to dynamic biological processes occurring at sites of drug presence. Our results highlight an important emerging technology allowing specific high resolution identification of unlabeled drugs at sites of in vivo uptake and retention

Neutrophil depletion reduces edema formation and tissue loss following traumatic brain injury in mice

Background: Brain edema as a result of secondary injury following traumatic brain injury (TBI) is a major clinical concern. Neutrophils are known to cause increased vascular permeability leading to edema formation in peripheral tissue, but their role in the pathology following TBI remains unclear. Methods: In this study we used controlled cortical impact (CCI) as a model for TBI and investigated the role of neutrophils in the response to injury. The outcome of mice that were depleted of neutrophils using an anti-Gr-1 antibody was compared to that in mice with intact neutrophil count. The effect of neutrophil depletion on blood-brain barrier function was assessed by Evan's blue dye extravasation, and analysis of brain water content was used as a measurement of brain edema formation (24 and 48 hours after CCI). Lesion volume was measured 7 and 14 days after CCI. Immunohistochemistry was used to assess cell death, using a marker for cleaved caspase-3 at 24 hours after injury, and microglial/macrophage activation 7 days after CCI. Data were analyzed using Mann-Whitney test for non-parametric data. Results: Neutrophil depletion did not significantly affect Evan's blue extravasation at any time-point after CCI. However, neutrophil-depleted mice exhibited a decreased water content both at 24 and 48 hours after CCI indicating reduced edema formation. Furthermore, brain tissue loss was attenuated in neutropenic mice at 7 and 14 days after injury. Additionally, these mice had a significantly reduced number of activated microglia/macrophages 7 days after CCI, and of cleaved caspase-3 positive cells 24 h after injury. Conclusion: Our results suggest that neutrophils are involved in the edema formation, but not the extravasation of large proteins, as well as contributing to cell death and tissue loss following TBI in mice