Libri sul tema "Distance spectra"

In this chapter, the operators considered are those m-sectorial operators discussed in Chapter VII, and the essential spectra are the sets defined in Chapter IX that remain invariant under compact perturbation. A generalization of a result of Persson is used to determine the least point of the essential spectrum. Davies’ mean distance function is introduced and consequences investigated.

Double photoionisation spectra of homologous iodides and alcohols, acetonitrile, methyl mercaptan, acetaldehyde, acetone, norbornane, cyclooctatetraene, and TMMD are presented. Effects on the spectra of these molecules from electronic state congestion and geometry changes on ionisation mean that only the lowest dication states can be identified. As little detailed analysis of the individual spectra is possible, this chapter presents the molecules in groups rather than individually. In this chapter, molecules are ordered more thematically than strictly by size. The chapter starts with four homologous iodides and three homologous alcohols. Then this chapter takes some individual molecules with different substituent groups and proceed to a few larger molecules. The chapter demonstrates the dominant effect of the distance to which charges can separate in the dication on the double ionisation threshold.

This epilogue considers the legacy of nineteenth-century sentimentalism, turning to contemporary civic statuary that memorializes nineteenth-century sentimentalists. Juxtaposing this statuary with the hauntingly ephemeral installation The Ghost of Liberty Street Church, the chapter offers postpresentist inquiry as a method that regards the archive as an urgent and poignantly incomplete political project. Where historicist approaches emphasize distance and difference from history through periodization, and charges of presentism name historians’ overidentification with the past, postpresentism holds in view intimacy and distance between past and the present. The epilogue lays out postpresentist readings of sculptures of Harriet E. Wilson in Milford, New Hampshire; Winnemucca Hopkins and Sojourner Truth in the United States Capitol Rotunda; and Elizabeth Cady Stanton, Amelia Bloomer, and Susan B. Anthony in Seneca Falls, New York. These statues’ site-specific installations bring into relief the raced, gendered, and colonial legacies of the grounds beneath their podia and feet.

Pompe disease, also named acid maltase deficiency and glycogen storage disease type II (GSDII), is a rare autosomal recessive disorder caused by the deficiency of the glycogen-degrading lysosomal enzyme acid α‎-glucosidase. The clinical spectrum of this disease is broad, varying from a lethal infantile-onset generalized myopathy including cardiomyopathy, to late-onset slowly progressive muscle weakness mimicking limb-girdle muscular dystrophy. Respiratory insufficiency is a frequent complication and the main cause of death. The prognosis of Pompe disease has changed considerably with the use of enzyme replacement therapy using recombinant acid α‎-glucosidase (alglucosidase alfa), which has been widely available since 2006. Improvements in survival and major motor achievements can be observed in patients with infantile forms, and recent studies demonstrate improvement of walking distance and stabilization of pulmonary function in late-onset forms. A longer-term study of the safety and efficacy of ERT, based on data gathering across the complete spectrum of Pompe disease via national or international patient registries, is needed in order to formulate more precise guidelines for treatment.

Device-to-Device (D2D) Communication and Non Orthogonal Multiple Access (NOMA) have become topics of interest for researchers. They are widely recognized as techniques of the next generation cellular wireless networks. D2D technique offers uninterrupted communication among proximate mobile users without transferring data to the base station. This can provide high data rates and power control mechanisms. If D2D direct link distance is more, or the quality of channel is poor then the direct D2D communication gives larger propagation losses. This type of scenarios use relay assisted D2D communication, for improving the transmission capacity and coverage. Where as NOMA ) is one of the many technologies that promise greater capacity gain and spectral efficiency than the present state of the art, and is a candidate technology for 5G cellular networks In this book, fundamentals, state of the art, applications and research challenges of D2D and NOMA have been discussed in simple language

This chapter examines the culture of the farmers of Hancock County, which was shaped in several ways by their rural lifestyles. First, work assignments were divided among family members by gender, with women performing the bulk of household production and raising small livestock while men tilled fields, hunted for local game, herded sheep, and harvested apples. To fit into the factory systems, these rural people would have to adapt to a new set of gender roles of the rising industries of the early twentieth century. Second, successful farming required a wide spectrum of skills that enabled farmers to coax a living out of their fields and forests. These skills would prove useful in making ends meet even after they started to draw paychecks from local factories. Finally, the farmers exhibited a preference for local autonomy, self-government, and independence from distant powers. Their ideals of self-reliance and independence in turn shaped their politics.

Anaesthesia in ‘remote areas’ is required for medical imaging (CT, MRI, PET-CT), angiography, endoscopy, and interventions (stenting, thrombectomy, coiling, laser therapy, biopsies, radiotherapy) in a number of medical disciplines (paediatrics, radiology, cardiology, pulmonology, gastroenterology, surgery, cardiac surgery, emergency medicine). The spectrum of anaesthetic techniques is broad. It reaches from standby (monitored anaesthesia care), through analgesia and sedation (with spontaneous breathing), to general anaesthesia and mechanical ventilation. Regional anaesthesia techniques are also required under certain circumstances. In the last few years there has been a move away from open procedures to interventional techniques. The complexity of these interventions has increased (i.e. interventional cardiac valve replacements) and the patients tend to be older and suffer from a multitude of co-morbidities. Many of these interventions are performed in the ‘hostile environment’ of the intervention suite. Intervention suites are typically not designed to offer anaesthetists an ideal working area. The space may be limited and medical equipment impedes access to the patient. The infrastructure may be suboptimal (e.g. no central medical gases supply). Protection for staff and equipment against radiation and high magnetic fields must be considered. Loud noise from machinery and shielded walls, doors, and windows may hinder communication and hearing acoustic alarms. The distance to the operating theatre may be considerable and thus support from senior anaesthetists and supply of additional equipment may take some time to arrive. Anaesthesia outside the operating theatre is sometimes underestimated as trivial. Performing a ‘quick’ interventional case can evolve within seconds into a challenge even for the experienced anaesthesiologist if a surgical or anaesthesiological complication occurs. Non-operating-theatre anaesthesia has a higher severity of injuries and more substandard care than operating theatre anaesthesia. This is not acceptable and anaesthetists must ensure the same high standard of anaesthesia care and patient safety both inside and outside the operating theatre.

This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.

It is obvious that the process of developing cancer—oncogenesis—is a multistep process. We know that smoking, obesity, and a family history are strong independent predictors of developing malignancy; yet, in clinics, we often see that some heavy smokers live into their nineties and that some people with close relatives affected by cancer spend many years worrying about a disease that, in the end, they never contract. For many centuries scientists have struggled to understand the process that make cancer cells different from normal cells. There were those in ancient times who believed that tumours were attributable to acts of the gods. Hippocrates suggested that cancer resulted from an imbalance between the black humour that came from the spleen, and the other three humours: blood, phlegm, and bile. It is only in the last 100 years that biologists have been able to characterize some of the pathways that lead to the uncontrolled replication seen in cancer, and subsequently examine exactly how these pathways evolve. The rampant nature by which cancer invades local and distant tissues, as well its apparent ability to spread between related individuals led some, such as Peyton Rous in 1910, to suggest that cancer was an infectious condition. He was awarded a Nobel Prize in 1966 for the 50 years of work into investigating a link between sarcoma in chickens and a retrovirus that became known as Rous sarcoma virus. He had shown how retroviruses are able to integrate sequences of DNA coding for errors in cellular replication control (oncogenes) by introducing into the human cell viral RNA together with a reverse transcriptase. Viruses are now implicated in many cancers, and in countries where viruses such as HIV and EBV are endemic, the high incidence of malignancies such as Kaposi’s sarcoma and Burkitt’s lymphoma is likely to be directly related. There are several families of viruses associated with cancer, broadly classed into DNA viruses, which mutate human genes using their own DNA, and retroviruses, like Rous sarcoma virus, which insert viral RNA into the cell, where it is then transcribed into genes. This link with viruses has not only led to an understanding that cancer originates from genetic mutations, but has also become a key focus in the design of new anticancer therapies. Traditional chemotherapies either alter DNA structure (as with cisplatin) or inhibit production of its component parts (as with 5-fluorouracil.) These broad-spectrum agents have many and varied side effects, largely due to their non-specific activity on replicating DNA throughout the body, not just in tumour cells. New vaccine therapies utilizing gene-coding viruses aim to restore deficient biological pathways or inhibit mutated ones specific to tumour cells. The hope is that these gene therapies will be effective and easily tolerated by patients, but development is currently progressing with caution. In a trial in France of ten children suffering from X-linked severe combined immunodeficiency and who were injected with a vector that coded for the gene product they lacked, two of the children subsequently died from leukaemia. Further analysis confirmed that the DNA from the viral vector had become integrated into an existing, but normally inactive, proto-oncogene, LM02, triggering its conversion into an active oncogene, and the development of life-threatening malignancy. To understand how a tiny change in genetic structure could lead to such tragic consequences, we need to understand the molecular biology of the cell and, in particular, to pay attention to the pathways of growth regulation that are necessary in all mammalian cell populations. Errors in six key regulatory pathways are known as the ‘hallmarks of cancer’ and will be discussed in the rest of this chapter.