385 research outputs found
A Danish register-based study on involuntary treatment in anorexia nervosa
Objective: Involuntary treatment is controversial and widely debated, but remains a significant component of treatment for severe anorexia nervosa. Given how little is known about this topic, we describe the frequency of various involuntary measures in a national cohort of all patients diagnosed with anorexia nervosa. In a subsample of patients, we explored predictors of the first involuntary measure recorded. Method: Descriptive statistics and Cox proportional hazard analyses were conducted using the national registers of Denmark covering the total population. Data from the National Patient Register and the Psychiatric Central Research Register including all psychiatric visits from 1969 onwards were merged with data from the National Register on Coercion covering 1999 onward. Involuntary measures registered between 2000 and 2013 were analyzed. Results: A total of 4,727 patients with a diagnosis of anorexia nervosa representing 16,592 admissions were included. Eighteen percent experienced at least one involuntary measure. A variety of measures were used with tube feeding being the most frequent followed by mechanical restraint, involuntary medication, physical restraint, constant observation, and sedative medication. A subsample of 2% of AN patients had more than 100 involuntary measures recorded. The first recorded involuntary measure was predicted by most but not all psychiatric comorbidities, especially schizophrenia, autism spectrum, and personality disorders, older age at first diagnosis, and previous admissions. Discussion: It is important to develop a more granular understanding of patients at risk of requiring involuntary treatment and to determine how best to treat them effectively with minimal use of involuntary measures
Prenatal and perinatal factors and risk of eating disorders
Background: Among the most disabling and fatal psychiatric illnesses, eating disorders (EDs) often manifest early in life, which encourages investigations into in utero and perinatal environmental risk factors. The objective of this study was to determine whether complications during pregnancy and birth and perinatal conditions are associated with later eating disorder risk in offspring and whether these associations are unique to EDs. Methods: All individuals born in Denmark to Danish-born parents 1989-2010 were included in the study and followed from their 6th birthday until the end of 2016. Exposure to factors related to pregnancy, birth, and perinatal conditions was determined using national registers, as were hospital-based diagnoses of anorexia nervosa (AN), bulimia nervosa, and eating disorder not otherwise specified during follow-up. For comparison, diagnoses of depressive, anxiety, and obsessive-compulsive disorders were also included. Cox regression was used to compare hazards of psychiatric disorders in exposed and unexposed individuals. Results: 1 167 043 individuals were included in the analysis. We found that similar to the comparison disorders, prematurity was associated with increased eating disorder risk. Conversely, patterns of increasing risks of EDs, especially in AN, with increasing parental ages differed from the more U-shaped patterns observed for depressive and anxiety disorders. Conclusions: Our results suggest that pregnancy and early life are vulnerable developmental periods when exposures may influence offspring mental health, including eating disorder risk, later in life. The results suggest that some events pose more global transdiagnostic risk whereas other patterns, such as increasing parental ages, appear more specific to EDs
The Initial Mass Function in disc galaxies and in galaxy clusters: the chemo-photometric picture
The observed brightness of the Tully-Fisher relation suggests a low stellar
M/L ratio and a "bottom-light" IMF in disc galaxies, but the corresponding
efficiency of chemical enrichment tends to exceed the observational estimates.
Either suitable tuning of the IMF slope and mass limits or metal outflows from
disc galaxies must then be invoked.
A standard Solar Neighbourhood IMF cannot explain the high metallicity of the
hot intra-cluster medium: a different IMF must be at work in clusters of
galaxies. Alternatively, if the IMF is universal and chemical enrichment is
everywhere as efficient as observed in clusters, substantial loss of metals
must occur from the Solar Neighbourhood and from disc galaxies in general; a
"non-standard" scenario challenging our understanding of disc galaxy formation.Comment: 6 pages, 4 figures; in Proceedings of IMF@50: the Initial Mass
Function 50 years later; Corbelli, Palla and Zinnecker (eds.
De Sitter Gravity and Liouville Theory
We show that the spectrum of conical defects in three-dimensional de Sitter
space is in one-to-one correspondence with the spectrum of vertex operators in
Liouville conformal field theory. The classical conformal dimensions of vertex
operators are equal to the masses of the classical point particles in dS_3 that
cause the conical defect. The quantum dimensions instead are shown to coincide
with the mass of the Kerr-dS_3 solution computed with the Brown-York stress
tensor. Therefore classical de Sitter gravity encodes the quantum properties of
Liouville theory. The equality of the gravitational and the Liouville stress
tensor provides a further check of this correspondence. The Seiberg bound for
vertex operators translates on the bulk side into an upper mass bound for
classical point particles. Bulk solutions with cosmological event horizons
correspond to microscopic Liouville states, whereas those without horizons
correspond to macroscopic (normalizable) states. We also comment on recent
criticism by Dyson, Lindesay and Susskind, and point out that the
contradictions found by these authors may be resolved if the dual CFT is not
able to capture the thermal nature of de Sitter space. Indeed we find that on
the CFT side, de Sitter entropy is merely Liouville momentum, and thus has no
statistical interpretation in this approach.Comment: 22 pages, LateX2e; added references for section 1 and section 2;
corrected typos; improved discussion in section
Approximating a Behavioural Pseudometric without Discount for<br> Probabilistic Systems
Desharnais, Gupta, Jagadeesan and Panangaden introduced a family of
behavioural pseudometrics for probabilistic transition systems. These
pseudometrics are a quantitative analogue of probabilistic bisimilarity.
Distance zero captures probabilistic bisimilarity. Each pseudometric has a
discount factor, a real number in the interval (0, 1]. The smaller the discount
factor, the more the future is discounted. If the discount factor is one, then
the future is not discounted at all. Desharnais et al. showed that the
behavioural distances can be calculated up to any desired degree of accuracy if
the discount factor is smaller than one. In this paper, we show that the
distances can also be approximated if the future is not discounted. A key
ingredient of our algorithm is Tarski's decision procedure for the first order
theory over real closed fields. By exploiting the Kantorovich-Rubinstein
duality theorem we can restrict to the existential fragment for which more
efficient decision procedures exist
Association of Exposure to Infections in Childhood with Risk of Eating Disorders in Adolescent Girls
Importance: Infections are recognized as playing a critical role in the risk of psychiatric disorders and suicidal behavior; however, few studies have evaluated the risk of eating disorders. Objective: To evaluate the association of hospitalization for infections and treatment with anti-infective agents with the risk of an eating disorder diagnosis. Design, Setting, and Participants: A nationwide, population-based, prospective cohort study of 525643 girls born from January 1, 1989, to December 31, 2006, and followed up until December 31, 2012, was conducted using individual-level data drawn from Danish longitudinal registers. Data were analyzed from January 15 to June 15, 2018, using survival analysis models and adjusted for age, calendar period, parental educational level, and parental history of psychiatric illness. Exposures: Hospital admission for infections and prescribed anti-infective agents for infections. Main Outcomes and Measures: The main outcome of interest was diagnosis of an eating disorder (anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified) in a hospital, outpatient clinic, or emergency department setting. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and accompanying 95% CIs. Results: The study population consisted of 525643 adolescent girls: 2131 received a diagnosis of anorexia nervosa (median [range] age, 15.2 [8.6-21.3] years), 711 received a diagnosis of bulimia nervosa (median [range] age, 17.9 [13.4-22.7] years), and 1398 received a diagnosis of an eating disorder not otherwise specified (median [range] age, 15.6 [8.6-21.6] years). A total of 525643 adolescent girls were followed up for 4601720.4 person-years until a mean age of 16.2 years (range, 10.5-22.7 years). Severe infections that required hospitalization were associated with an increased risk of a subsequent diagnosis of anorexia nervosa by 22% (HR, 1.22; 95% CI, 1.10-1.35), bulimia nervosa by 35% (HR, 1.35; 95% CI, 1.13-1.60), and eating disorder not otherwise specified by 39% (HR, 1.39; 95% CI, 1.23-1.57) compared with adolescent girls without hospitalizations for infections. Infections treated with anti-infective agents were associated with an increased risk of a subsequent diagnosis of anorexia nervosa by 23% (HR, 1.23; 95% CI, 1.10-1.37), bulimia nervosa by 63% (HR, 1.63; 95% CI, 1.32-2.02), and eating disorder not otherwise specified by 45% (HR, 1.45; 95% CI, 1.25-1.67) compared with adolescent girls without infections treated with anti-infective agents. Conclusions and Relevance: The findings suggest that hospital-treated infections and less severe infections treated with anti-infective agents are associated with increased risk of subsequent anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified and that future studies should investigate whether these associations are causal and identify the exact mechanisms between infections and subsequent inflammatory processes with eating disorders
What we don't know about time
String theory has transformed our understanding of geometry, topology and
spacetime. Thus, for this special issue of Foundations of Physics commemorating
"Forty Years of String Theory", it seems appropriate to step back and ask what
we do not understand. As I will discuss, time remains the least understood
concept in physical theory. While we have made significant progress in
understanding space, our understanding of time has not progressed much beyond
the level of a century ago when Einstein introduced the idea of space-time as a
combined entity. Thus, I will raise a series of open questions about time, and
will review some of the progress that has been made as a roadmap for the
future.Comment: 15 pages; Essay for a special issue of Foundations of Physics
commemorating "Forty years of string theory
Spin transport of electrons through quantum wires with spatially-modulated strength of the Rashba spin-orbit interaction
We study ballistic transport of spin-polarized electrons through quantum
wires in which the strength of the Rashba spin-orbit interaction (SOI) is
spatially modulated. Subband mixing, due to SOI, between the two lowest
subbands is taken into account. Simplified approximate expressions for the
transmission are obtained for electron energies close to the bottom of the
first subband and near the value for which anticrossing of the two lowest
subbands occurs. In structures with periodically varied SOI strength, {\it
square-wave} modulation on the spin transmission is found when only one subband
is occupied and its possible application to the spin transistor is discussed.
When two subbands are occupied the transmission is strongly affected by the
existence of SOI interfaces as well as by the subband mixing
HbA 1C variability and hypoglycemia hospitalization in adults with type 1 and type 2 diabetes: A nested case-control study
Aims To determine association between HbA1C variability and hypoglycemia requiring hospitalization (HH) in adults with type 1 diabetes (T1D) and type 2 diabetes (T2D). Methods Using nested case-control design in electronic health record data in England, one case with first or recurrent HH was matched to one control who had not experienced HH in incident T1D and T2D adults. HbA1C variability was determined by standard deviation of ≥ 3 HbA1C results. Conditional logistic models were applied to determine association of HbA1C variability with first and recurrent HH. Results In T1D, every 1.0% increase in HbA1C variability was associated with 90% higher first HH risk (95% CI, 1.25–2.89) and 392% higher recurrent HH risk (95% CI, 1.17–20.61). In T2D, a 1.0% increase in HbA1C variability was associated with 556% higher first HH risk (95% CI, 3.88–11.08) and 573% higher recurrent HH risk (95% CI,1.59–28.51). In T2D for first HH, the association was the strongest in non-insulin non-sulfonylurea users (P < 0.0001); for recurrent HH, the association was stronger in insulin users than sulfonylurea users (P = 0.07). The HbA1C variability-HH association was stronger in more recent years in T2D (P ≤ 0.004). Conclusions HbA1C variability is a strong predictor for HH in T1D and T2D
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