We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This book describes a constructive approach to the Inverse Galois problem: Given a finite group G and a field K, determine whether there exists a Galois extension of K whose Galois group is isomorphic to G. Further, if there is such a Galois extension, find an explicit polynomial over K whose Galois group is the prescribed group G. The main theme of the book is an exposition of a family of 'generic' polynomials for certain finite groups, which give all Galois extensions having the required group as their Galois group. The existence of such generic polynomials is discussed, and where they do exist, a detailed treatment of their construction is given. The book also introduces the notion of 'generic dimension' to address the problem of the smallest number of parameters required by a generic polynomial.
Contaminated surfaces in clinics pose a pathogen transmission risk. Far ultraviolet-C light (UVC), with a favorable safety profile for human exposure, has the potential for continuous pathogen inactivation in occupied clinical areas. This study demonstrated real-world bioburden reduction on surfaces, despite frequent contamination from routine use by staff and patients in clinics.
Men with spinal cord injury often suffer from erectile dysfunction, ejaculatory dysfunction, infertility, and hypogonadism. Restoration of sexual and reproductive functions is a top priority and efficient treatment modalities exist. Erectile dysfunction can be treated with phosphodiesterase-5 inhibitors and if unsuccessful intracavernosal injections can be tried. When injections fail a penile implant can ultimately be an option. Anejaculation and the resulting infertility are treated in a stepwise approach with penile vibratory stimulation, electroejaculation and surgical sperm retrieval followed by assisted reproduction. Assisted ejaculation is an effective and safe procedure but carries a risk of autonomic dysreflexia, especially in men with injuries at the level of T6 or above. Autonomic dysreflexia is an unregulated and uncontrolled response of the sympathetic nervous system but it can be safely managed. Hypogonadism is more prevalent in men with spinal cord injury compared to the general population and testosterone replacement therapy can be beneficial for alleviating symptoms of low testosterone, but testosterone-related spermatogenic suppression needs to be considered in men who wish to initiate a pregnancy.
Because economic outcomes depend on private-sector expectations, central banks might be tempted to guide these by publishing projections of key macroeconomic variables. We find that optimal projections require misleading the public. Optimal non-misleading projections are time-inconsistent. Non-misleading time-consistent projections can only improve policy outcomes if the public’s forecasts are noisier, or inconsistent with implemented policy. Since the public only has incentives to be guided by policymakers’ projections when most vulnerable to being mislead, these cannot be trusted blindly. Consistent with this, we find statistically significant systematic deviations between FOMC projections and professional forecasts for US inflation and GDP growth.
The population of long-term survivors with CHDs is increasing due to better diagnostics and treatment. This has revealed many co-morbidities including different neurocognitive difficulties. However, the prevalence of psychiatric disorders among children and adolescents and the specific types of disorders they may experience are unclear. We systematically reviewed the existing literature, where psychiatric diagnoses or psychiatric symptoms were investigated in children and adolescents (age: 2–18 aged) with CHDs and compared them with a heart-healthy control group or normative data. The searches were done in the three databases PubMed, psychINFO, and Embase. We included 20 articles reporting on 8035 unique patients with CHDs. Fourteen articles repoted on psychological symptoms, four reported on psychiatric diagnoses, and two reported on both symptoms and diagnoses. We found that children and adolescents with a CHD had a higher prevalence of attention deficit hyperactivity disorder (ranging between 1.4 and 9 times higher) and autism (ranging between 1.8 and 5 times higher) than controls, but inconsistent results regarding depression and anxiety.
To examine associations between socioeconomic factors and (1) adherence to methicillin-resistant Staphylococcus aureus (MRSA) posttreatment follow-up swab sampling after 1 and 6 months and (2) successful decolonization treatment.
Design:
Cohort study with 2 years of follow-up. Data on patients diagnosed with MRSA were extracted from a regional MRSA database and national registries. We used a cluster-based logistic regression model to estimate the adjusted odds ratios (aOR) and 95% confidence interval (CI) for associations between socioeconomic factors and decolonization treatment.
Setting:
Danish primary health care.
Results:
The rate of adherence to posttreatment follow-up swab sampling among 2,536 cases 1 month after decolonization treatment was 66% (95% CI, 64%–68%), and it decreased to 30% (95% CI, 28%–32%) after 6 months. Living in intermediate municipalities (76–159 inhabitants/km2) or having retired were associated with completed posttreatment follow-up swabs 1 month after decolonization treatment: aOR, 1.40 (95% CI, 1.2–1.74) and aOR, 2.67 (95% CI, 1.16–6.13), respectively. The rate of successful decolonization treatment 2 years after initiating treatment was 36% (95% CI, 34%–38%). Factors associated with successful decolonization treatment included individuals with higher education (aOR, 1.62; 95% CI, 1.22–2.15), early retirees (aOR, 1.63; 95% CI, 1.12–2.38), those living in intermediate municipalities (ie, 160–900+ inhabitants/km2; aOR, 1.35; 95% CI, 1.08–1.68), and those living in predominantly urban municipalities (ie, 160–900+ inhabitants/km2; aOR, 2.04; 95% CI, 1.5–2.76).
Conclusions:
Disparities in the effect of decolonization treatment and adherence to MRSA follow-up sampling among MRSA-positive individuals appear to be largely explained by the level of education, area of residence, and employment status.
This chapter looks at the direction the debates on social and economic human rights took after the adoption of the International Covenant on Economic, Social and Cultural Rights in 1966 and until the late 1980s. The focus is on the United Nations as the debates here reflected larger political questions about the meaning and relevance of social and economic rights as obligations in the unfolding post-colonial world. With decolonisation, the former colonial powers had been ‘liberated’ from the obligations of empire while many rulers in newly independent states used the new-found sovereignty to avoid scrutiny of the broad range of human rights. Decolonisation proved to be the perfect storm for social and economic rights denial. This would be further entrenched by expanding neo-liberal reforms and debt management leading to the ‘lost decade’ for development during the 1980s. Despite social and economic rights being continually neglected, the chapter argues that they always remained central to the problem of human rights.
Germination experiments are becoming increasingly complex and they are now routinely involving several experimental factors. Recently, a two-step approach utilizing meta-analysis methodology has been proposed for the estimation of hierarchical models suitable for describing data from such complex experiments. Step 1 involves fitting models to data from each sub-experiment, whereas Step 2 involves combination estimates from all model fits obtained in Step 1. However, one shortcoming of this approach was that visualization of resulting fitted germination curves was difficult. Here, we describe in detail an improved two-step analysis that allows visualization of cumulated data together with fitted curves and confidence bands. Also, we demonstrate in detail, through two examples, how to carry out the statistical analysis in practice.
Many cognitive functions are under strong genetic control and twin studies have demonstrated genetic overlap between some aspects of cognition and schizophrenia. How the genetic relationship between specific cognitive functions and schizophrenia is influenced by IQ is currently unknown.
Methods
We applied selected tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) to examine the heritability of specific cognitive functions and associations with schizophrenia liability. Verbal and performance IQ were estimated using The Wechsler Adult Intelligence Scale-III and the Danish Adult Reading Test. In total, 214 twins including monozygotic (MZ = 32) and dizygotic (DZ = 22) pairs concordant or discordant for a schizophrenia spectrum disorder, and healthy control pairs (MZ = 29, DZ = 20) were recruited through the Danish national registers. Additionally, eight twins from affected pairs participated without their sibling.
Results
Significant heritability was observed for planning/spatial span (h2 = 25%), self-ordered spatial working memory (h2 = 64%), sustained attention (h2 = 56%), and movement time (h2 = 47%), whereas only unique environmental factors contributed to set-shifting, reflection impulsivity, and thinking time. Schizophrenia liability was associated with planning/spatial span (rph = −0.34), self-ordered spatial working memory (rph = −0.24), sustained attention (rph = −0.23), and set-shifting (rph = −0.21). The association with planning/spatial span was not driven by either performance or verbal IQ. The remaining associations were shared with performance, but not verbal IQ.
Conclusions
This study provides further evidence that some cognitive functions are heritable and associated with schizophrenia, suggesting a partially shared genetic etiology. These functions may constitute endophenotypes for the disorder and provide a basis to explore genes common to cognition and schizophrenia.
To compare dietary intake and physical activity (PA) between days of the week in a large sample of the Danish population; furthermore, to investigate the influence of gender and age as determinants for weekly variation.
Design:
Analysis was based on cross-sectional data from the Danish National Survey of Diet and Physical Activity 2011–2013. Dietary intake and PA were assessed by 7 d of pre-coded food diaries and pedometer-determined step counts. Dietary intake and PA on weekdays (Monday–Thursday), Friday, and weekend days (Saturday and Sunday) were compared using linear mixed models.
Setting:
Survey with national representation, conducted in Denmark between 2011 and 2013.
Participants:
A random sample of 4–75-year-old Danes, n 3934 and n 3530 in analysis of dietary intake and PA, respectively.
Results:
Energy intake during Friday and weekend days was 7–20 % higher compared with weekdays, while step counts were 10 and 17 % lower on Saturday and Sunday, respectively (all P < 0·001). Energy density of liquids and solids, consumption of added sugar, alcohol, discretionary foods, beer, wine and sugar-sweetened beverages were substantially higher, and consumption of dietary fibre, vegetables, fruit and wholegrain products were lower, during Friday and weekend days compared with weekdays (all P < 0·001). The observed patterns were present across gender and age, although weekly variation was most pronounced among children and relatively modest among the elderly.
Conclusions:
Weekend health behaviours of Danes display less favourable eating and PA behaviour compared with weekdays, making the weekend an important target for public health interventions aiming to improve dietary intake and PA behaviour.
Weight gain among psychiatric inpatients is a widespread phenomenon. This change in body mass index (BMI) can be caused by several factors. Based on recent research, we assume the following factors are related to weight gain during psychiatric inpatient treatment: psychiatric medication, psychiatric diagnosis, sex, age, weight on admission and geographic region of treatment.
876 of originally recruited 2328 patients met the criteria for our analysis. Patients were recruited and examined in mental health care centres in Nigeria (N=265), Japan (N=145) and Western-Europe (Denmark, Germany and Switzerland; N=466).
There was a significant effect of psychiatric medication, psychiatric diagnoses and geographic region, but not age and sex, on BMI changes. Geographic region had a significant effect on BMI change, with Nigerian patients gaining significantly more weight than Japanese and Western European patients. Moreover, geographic region influenced the type of psychiatric medication prescribed and the psychiatric diagnoses. The diagnoses and psychiatric medication prescribed had a significant effect on BMI change.
In conclusion, we consider weight gain as a multifactorial phenomenon that is influenced by several factors. One can discuss a number of explanations for our findings, such as different clinical practices in the geographical regions (prescribing or admission strategies and access-to-care aspects), as well as socio-economic and cultural differences.
Alfred Schild has established conditions that Lorentz transformationsmap world-vectors $(ct,x,y,z)$ with integer coordinates onto vectors of the same kind. These transformations are called integral Lorentz transformations.
This paper contains supplements to our earlier work with a new focus on group theory. To relate the results to the familiar matrix group nomenclature, we associate Lorentz transformations with matrices in $\text{SL}(2,\mathbb{C})$. We consider the lattice of subgroups of the group originated in Schild's paper and obtain generating sets for the full group and its subgroups.
High-dose vitamin A supplementation (VAS) may affect mortality to infectious diseases in a sex-differential manner. Here, we analysed the long-term immunological effects of neonatal vitamin A supplementation (NVAS) in 247 children, who had been randomly allocated to 50 000 or 25 000 IU vitamin A (15mg and 7·5mg retinol equivalents, respectively) or placebo at birth. At 4–6 months of age, we assessed bacille Calmette–Guérin (BCG) scarification, and we analysed in vitro responses of TNF-α, IL-5, IL-10, IL-13 and IFN-γ in whole blood stimulations to phytohaemagglutinin (PHA), purified protein derivative (PPD), tetanus toxoid and lipopolysaccharide. There were no differences between the two doses of NVAS, and thus they were analysed combined as NVAS (any dose) v. placebo. All analyses were performed unstratified and by sex. NVAS increased the chance of having a scar after BCG vaccination in females (NVAS v. placebo: 96 v. 71 %, proportion ratio: 1·24; 95 % CI 1·09, 1·42), but not in males (Pfor interaction=0·012). NVAS was associated with significant sex-differential effects on the pro- to anti-inflammatory cytokine ratios (TNF-α:IL-10) to PPD, tetanus toxoid and medium alone, which were increased in females but decreased in males. In addition, IL-17 responses tended to be increased in NVAS v. placebo recipients in males but not in females, significantly so for the PHA stimulation. The study corroborates sex-differential effects of VAS on the immune system, emphasising the importance of analysing VAS effects by sex.
In recent years germination experiments have become more and more complex. Typically, they are replicated in time as independent runs and at each time point they involve hierarchical, often factorial experimental designs, which are now commonly analysed by means of linear mixed models. However, in order to characterize germination in response to time elapsed, specific event-time models are needed and mixed model extensions of these models are not readily available, neither in theory nor in practice. As a practical workaround we propose a two-step approach that combines and weighs together results from event-time models fitted separately to data from each germination test by means of meta-analytic random effects models. We show that this approach provides a more appropriate appreciation of the sources of variation in hierarchically structured germination experiments as both between- and within-experiment variation may be recovered from the data.
When the returns to scale of a production process vary with the intensity it is operated at, an AK model with constant returns to scale in production arises endogenously due to replication driven by profit maximization. If replication occurs at the efficiency-maximizing scale, as with perfect competition, the result applies also when the number of production processes must be discrete, thus, overcoming the so-called integer problem. When competition is imperfect, there is only convergence toward the AK model for large enough input use, so an economy is more prone to stalling in a steady state without growth, the smaller and less competitive it is.
This article discusses the concept of relative potency of herbicides in bioassays where individual dose–response curves can be similar or nonsimilar, often denoted parallel and nonparallel curves, and have different upper and lower limits. The relative potency is constant for similar dose–response curves and measures the relative horizontal displacement of curves of a similar shape along the dose axis on a logarithmic scale. The concept of similar dose–response curves has been used extensively to assess results from herbicide experiments, for example, with the purpose of adjusting herbicide doses to environmental conditions, formulations, and adjuvants. However, deeming dose–response curves similar when they are not may greatly affect the calculation of the relative potency at response levels such as effective dosage (ED)90, which is relevant for effective weed control, or ED10, which is used in crop tolerance studies. We present a method for calculating relative potencies between nonsimilar dose–response curves at any response level. It also is demonstrated that if the upper, lower, or both limits among response curves are substantially different, then the ED50 or any other ED level cannot be used indiscriminately to compute the relative potency. Rather, the relative potency should be viewed as a function of the response level.
Nurses and respiratory therapists are seldom allowed to use automated external defibrillators (AED) during in-hospital cardiac arrest. This can result in significant time delays before defibrillation occurs and lower survival for cardiac arrest victims. We sought to identify barriers and facilitators to AED use by nurses and respiratory therapists.
Methods
We conducted semi-structured qualitative interviews with a purposeful sample of nurses and respiratory therapists. We developed the interview guide based on the constructs of the theory of planned behaviour, which elicits salient attitudes, social influences, and control beliefs potentially influencing the intent to use an AED. Interviews were recorded, transcribed verbatim, and analysed until achieving data saturation. Two independent reviewers performed inductive analyses to identify emerging categories and themes, and ranked them by frequency of the number of participants stating the topic.
Results
Demographics for the 24 interviewees include mean age 40.5, 79.2% female, 87.5% performed cardiopulmonary resuscitation (CPR), 29.2% defibrillated a patient. Identified attitudes pertained to the timeliness of defibrillation, patient survival, simplicity of AED use, accuracy of rhythm recognition, and harm to self or others. Social influences consisted of physician and hospital administration support of AED use. Control beliefs included training on AED use, policy allowing AED use, familiarity with AED, and task burden during resuscitation.
Conclusions
Most nurses and respiratory therapists intended to use an AED if permitted to do so by a medical directive. Successful implementation would require educational initiatives focusing on safety and efficacy of AEDs, support from physicians and hospital administrators, and additional training on AED use.
Seasonal variation is a characteristic of many infectious diseases, but relatively little is known about determinants thereof. We studied the impact of place of acquisition and patient characteristics on seasonal variation of bacteremia caused by the 3 most common pathogens.
DESIGN
Seasonal variation analysis.
METHODS
In 3 Danish health regions (2.3 million total inhabitants), patients with bacteremia were identified from 2000 through 2011 using information from laboratory information systems. Analyses were confined to Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Additional data were obtained from the Danish National Hospital Registry for the construction of admission histories and calculation of the Charlson comorbidity index (CCI). Bacteremias were categorized as community acquired, healthcare associated (HCA), and hospital acquired. We defined multiple subgroups by combining the following characteristics: species, acquisition, age group, gender, CCI level, and location of infection. Assuming a sinusoidal model, seasonal variation was assessed by the peak-to-trough (PTT) ratio with a 95% confidence interval (CI).
RESULTS
In total, we included 16,006 E. coli, 6,924 S. aureus, and 4,884 S. pneumoniae bacteremia cases. For E. coli, the seasonal variation was highest for community-acquired cases (PTT ratio, 1.24; 95% CI, 1.17–1.32), was diminished for HCA (PTT ratio, 1.14; 95% CI, 1.04–1.25), and was missing for hospital-acquired cases. No seasonal variation was observed for S. aureus. S. pneumoniae showed high seasonal variation, which did not differ according to acquisition (overall PTT ratio, 3.42; 95% CI, 3.10–3.83).
CONCLUSIONS
Seasonal variation was mainly related to the species although the place of acquisition was important for E. coli.
Alfred Schild established conditions where Lorentz transformations map world-vectors $\left( ct,\,x,\,y,\,z \right)$ with integer coordinates onto vectors of the same kind. The problem was dealt with in the context of tensor and spinor calculus. Due to Schild’s number-theoretic arguments, the subject is also interesting when isolated from its physical background.
Schild’s paper is not easy to understand. Therefore, we first present a streamlined version of his proof which is based on the use of null vectors. Then we present a purely algebraic proof that is somewhat shorter. Both proofs rely on the properties of Gaussian integers