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1.
Nat Commun ; 12(1): 5173, 2021 08 27.
Article in English | MEDLINE | ID: mdl-34453047

ABSTRACT

Disease modelling has had considerable policy impact during the ongoing COVID-19 pandemic, and it is increasingly acknowledged that combining multiple models can improve the reliability of outputs. Here we report insights from ten weeks of collaborative short-term forecasting of COVID-19 in Germany and Poland (12 October-19 December 2020). The study period covers the onset of the second wave in both countries, with tightening non-pharmaceutical interventions (NPIs) and subsequently a decay (Poland) or plateau and renewed increase (Germany) in reported cases. Thirteen independent teams provided probabilistic real-time forecasts of COVID-19 cases and deaths. These were reported for lead times of one to four weeks, with evaluation focused on one- and two-week horizons, which are less affected by changing NPIs. Heterogeneity between forecasts was considerable both in terms of point predictions and forecast spread. Ensemble forecasts showed good relative performance, in particular in terms of coverage, but did not clearly dominate single-model predictions. The study was preregistered and will be followed up in future phases of the pandemic.


Subject(s)
COVID-19/epidemiology , COVID-19/virology , Forecasting , Germany/epidemiology , Humans , Models, Statistical , Pandemics/statistics & numerical data , Poland/epidemiology , SARS-CoV-2/physiology , Seasons
2.
Phys Rev E Stat Nonlin Soft Matter Phys ; 68(6 Pt 2): 066107, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14754269

ABSTRACT

We study the surfaces of lowest energy through model polycrystalline materials in two and three dimensions. When the grain boundaries are sufficiently weak, these critical manifolds (CM's) lie entirely on grain boundaries, while when the grain boundaries are strong, cleavage occurs. A scaling theory for the intergranular to transgranular transition of CM's is developed. The key parameters are the average grain size g, the ratio of grain boundary to the grain interior energy, epsilon, and the sample size L. The key result is that a critical length scale exists, L(c)(g,epsilon), so that on short length scales lL(c), the critical manifold is rough. We develop a scaling theory for L(c) and find that in two dimensions L(c) approximately gx(y(2)), while in three dimensions L(c) approximately g exp(bx(y(3))), where x=epsilon/(1-epsilon) and b is a constant. Data from realistic polycrystalline grain structures are used to test the scaling theory. The exact lowest energy surface through model grain structures is found using a mapping to the minimum-cut/maximum-flow problem in computer science. As a function of grain-boundary energy, we observe the crossover from grain-boundary rupture to mixed mode failure (a mixture of transgramular and intergranular modes) and finally cleavage and that the two-dimensional data are consistent with y(2) approximately 3.0+/-0.3, while the three-dimensional data are more difficult to analyze, but are consistent with y(3) approximately 3.5+/-1.0.

3.
Phys Rev E Stat Nonlin Soft Matter Phys ; 64(3 Pt 2): 036112, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11580399

ABSTRACT

Two attractive and often used ideas, namely, universality and the concept of a zero-temperature fixed point, are violated in the infinite-range random-field Ising model. In the ground state we show that the exponents can depend continuously on the disorder and so are nonuniversal. However, we also show that at finite temperature the thermal order-parameter exponent 1/2 is restored so that temperature is a relevant variable. Broader implications of these results are discussed.

4.
Can J Neurol Sci ; 27(2): 116-9, 2000 May.
Article in English | MEDLINE | ID: mdl-10830343

ABSTRACT

BACKGROUND: The American Heart Association carotid endarterectomy (CE) guidelines endorse CE for asymptomatic carotid stenosis if the procedure can be performed with low morbidity. However, the Canadian Stroke Consortium has published a consensus against CE for asymptomatic stenosis. The views of practicing neurologists in the two countries on this subject are unclear. METHODS: A survey was undertaken of 270 neurologists from either Florida or Indiana and 180 neurologists from either Ontario or Quebec. RESULTS: The survey was returned by 36% of neurologists. Both Florida (65%) and Indiana neurologists (35%) were significantly more likely than Canadian neurologists (11%) to sometimes/often refer patients for surgery(p<0.001). Neurologists from Florida relied more on noninvasive methods of carotid stenosis assessment (36%) than Canadian neurologists (12%, p=0.003), who preferred angiography. Neurologists from Florida more often cited medicolegal concerns as a reason for referring patients for surgery (27%), compared to Canadian neurologists (3%, p=0.0001). CONCLUSIONS: Practices pertaining to carotid stenosis evaluation and management differ both regionally and by country. Canadian neurologists refer fewer asymptomatic patients for CE and rely more on angiography as a preoperative diagnostic tool. The potential of medicolegal liability is a greater force in clinical decision-making for certain U.S. neurologists, compared to their Canadian counterparts. These differences may partly explain the variations in CE utilization in the two countries.


Subject(s)
Attitude of Health Personnel , Carotid Stenosis/surgery , Endarterectomy, Carotid/statistics & numerical data , Neurology/statistics & numerical data , Canada , Carotid Stenosis/diagnosis , Carotid Stenosis/economics , Cerebral Angiography , Cross-Cultural Comparison , Health Care Surveys , Humans , Neurology/legislation & jurisprudence , Physician Self-Referral/statistics & numerical data , Physicians/psychology , Professional Practice , Reimbursement Mechanisms , United States
6.
J Pediatr ; 133(4): 521-5, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9787691

ABSTRACT

OBJECTIVE: The objective of this clinical study was to determine the effects of sex steroids on behavior and mood in adolescents with hypogonadism. STUDY DESIGN: The experimental design consisted of a randomized, double-blind, placebo-controlled, crossover trial lasting for 21 months. The study group consisted of 39 boys and 16 girls recruited from a pediatric endocrine clinic for delayed puberty. Depo-testosterone (to boys) or conjugated estrogens (to girls) was administered in 3-month blocks, alternating with placebo, at 3 dose levels approximating early, middle, and late pubertal amounts. The Child Behavior Checklist, Youth Self Report, Differential Emotion Scale, and Daily Mood Diary were administered after each placebo and treatment period to ascertain the effect of sex steroids on self- and parent-reported behavior problems and moods. RESULTS: The data demonstrated only one significant treatment effect, namely, an increase in withdrawn behavior problems during administration of low-dose estrogen in girls. There were no consistent sex differences. CONCLUSION: These results demonstrate that administered testosterone or estrogen has minimal effects on behavior problems or mood in adolescents.


Subject(s)
Affect/drug effects , Anabolic Agents/pharmacology , Anabolic Agents/therapeutic use , Estrogens, Conjugated (USP)/pharmacology , Estrogens, Conjugated (USP)/therapeutic use , Hormone Replacement Therapy , Mental Disorders/complications , Mental Disorders/psychology , Puberty, Delayed/complications , Puberty, Delayed/drug therapy , Testosterone/analogs & derivatives , Adolescent , Adult , Child , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Female , Humans , Male , Mental Disorders/diagnosis , Puberty, Delayed/psychology , Testosterone/pharmacology , Testosterone/therapeutic use
7.
Dtsch Med Wochenschr ; 121(48): 1492-7, 1996 Nov 29.
Article in German | MEDLINE | ID: mdl-8983905

ABSTRACT

HISTORY AND CLINICAL FINDINGS: A 35-year-old previously healthy man developed a painful swelling in the area of the left sternoclavicular joint (SCJ), restricting movement. There had been no history of trauma. INVESTIGATIONS: A moderately increased erythrocyte sedimentation rate was the only abnormal finding among the usual laboratory tests. Radiologically there were marked hyperostotic changes in the area of the left upper thoracic cage with synostosis of the SCJ. Biopsy of the left clavicle showed non-specific chronic sclerosing osteomyelitis. TREATMENT AND COURSE: Over the next 6 years the SCJ became completely ankylosed and there were now extensive fibroses, some presternal and some in the upper mediastinum with thrombosis of the left subclavian, axillary and jugular veins causing inflow occlusion (Paget-von-Schroetter-syndrome). Lymph nodes in the region of the mandible, jugular veins bilaterally and mediastinum were noted for the first time, remaining unchanged in size over six months. CONCLUSION: Sternoclavicular hyperostosis is an important condition in the differential diagnosis of inflammatory or malignant processes of this joint.


Subject(s)
Hyperostosis, Sternocostoclavicular/diagnostic imaging , Adult , Blood Sedimentation , Diagnosis, Differential , Humans , Hyperostosis, Sternocostoclavicular/blood , Male , Radiography, Thoracic , Radionuclide Imaging , Tomography, X-Ray Computed
8.
Klin Wochenschr ; 68(19): 959-63, 1990 Oct 03.
Article in English | MEDLINE | ID: mdl-2232626

ABSTRACT

H2-receptor antagonists are known to fail to increase the intragastric pH in some patients (so-called non-responders), and we have recently found a higher frequency of non-responders among cirrhotics. Since intragastric pH is also affected by gastric emptying, in the present study we determined the gastric emptying of 300 ml orange juice labelled with [99mTc]-Solco Nanocoll using a gamma camera. Measurements were made over a period of 60 min in cirrhotic patients and controls without liver disease who either responded to 300 mg ranitidine or showed no response. The mean (+/- SD) liquid half-emptying time (T1/2) was 26.3 +/- 17.5 min (range, 9-75 min) in responders (n = 10), 20.9 +/- 8.6 min (range, 7-34 min) in non-responders (n = 10), 19.4 +/- 19.2 min (range, 7-75 min) in cirrhotics (n = 11), and 27 +/- 4.6 min (range, 17-33 min) in controls (n = 9). In 19 of the 20 subjects gastric emptying was normal (T1/2, less than 40 min). Since gastric emptying was not delayed in any of the non-responders, it would appear very unlikely that gastric motility plays a major role in the non-response to H2-receptor antagonists.


Subject(s)
Gastric Emptying , Ranitidine/therapeutic use , Stomach Diseases/physiopathology , Adult , Aged , Drug Resistance , Esophagitis, Peptic/drug therapy , Female , Gastric Emptying/drug effects , Gastritis/drug therapy , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Peptic Ulcer/drug therapy , Stomach Diseases/drug therapy
9.
J Clin Pathol ; 43(6): 488-92, 1990 Jun.
Article in English | MEDLINE | ID: mdl-2166093

ABSTRACT

A monoclonal antibody was raised against the major capsid protein L1 of human papillomavirus type 16, using a recombinant vaccinia virus that expresses the L1 protein, as a target for screening. This antibody, designated CAMVIR-1, reacted with a 56 kilodalton protein in cells infected with L1-vaccinia virus, and the protein was present in a predominantly nuclear location. The antibody also detects the HPV-16 L1 antigen in formalin fixed, paraffin wax embedded biopsy specimens and on routine cervical smears. The antibody reacts strongly and consistently with biopsy specimens containing HPV-16 or HPV-33, but very weak reactions were occasionally observed with biopsy specimens or smears containing HPV-6 or HPV-11. The potential advantages of using a vaccinia recombinant are (i) the target protein is synthesised in a eukoryotic cell so that its "processing" and location are normal; (ii) cells infected with vaccinia recombinants can be subjected to various fixing procedures similar to those used for routine clinical material. This greatly increases the probability that an identified antibody will be useful in a clinical setting.


Subject(s)
Antibodies, Monoclonal/biosynthesis , Papillomaviridae/immunology , Vaccinia virus/immunology , Animals , Antibodies, Viral/biosynthesis , Antigens, Viral/immunology , Capsid/immunology , Cervix Uteri/microbiology , DNA, Viral/analysis , Female , Humans , Immunologic Techniques , Mice , Recombinant Fusion Proteins/immunology , Vaginal Smears , Viral Fusion Proteins/immunology
10.
Blut ; 52(5): 317-21, 1986 May.
Article in English | MEDLINE | ID: mdl-3635418

ABSTRACT

An unusual case of a 37 degrees C-active irregular anti-A1 is reported. Apparently consisting mainly of IgG, the antibody appeared in an A2B recipient only two days after massive transfusion of A1-cells in absence of previous transfusion. It was associated with severe hemolysis and renal failure which was reversed after exchange transfusion.


Subject(s)
ABO Blood-Group System/immunology , Antibodies/analysis , Transfusion Reaction , Female , Hemolysis , Humans , Kidney Function Tests , Middle Aged , Urine
11.
Pediatr Hematol Oncol ; 3(3): 205-16, 1986.
Article in English | MEDLINE | ID: mdl-2484676

ABSTRACT

Treatment of neuroblastoma is an unsolved problem of pediatric oncology. In spite of highly intensified chemotherapy, the long-term survival rate of children with a metastatic neuroblastoma is below 10%. We therefore used 131I-metaiodobenzylguanidine (MIBG) for the first time to treat children with a neuroblastoma in relapse or primary unresponsiveness to chemotherapy. We had previously demonstrated that MIBG is useful for the scintigraphic imaging of neuroblastoma lesions and had investigated the cytotoxicity and uptake of MIBG in various neuroblastoma cell lines. We treated 6 children with neuroblastoma in a total of 19 courses. Three of the children suffered from a relapse of neuroblastoma; 3 had never gained a remission. Four of the 6 children lost their bone pain and fever during the first 3 days. In 5 of the 6 children the solid tumor as well as the bone marrow infiltration responded to MIBG treatment, with responses ranging from transitory decrease of the tumor mass to complete disappearance of abdominal tumors. We also witnessed a stabilization of osteolytic lesions, a decrease in elevated serum catecholamines, and a decrease in bone marrow infiltration. Five of the 6 children died of tumor progression 55-249 days after the first MIBG treatment.


Subject(s)
Iodine Radioisotopes/therapeutic use , Iodobenzenes/therapeutic use , Neuroblastoma/radiotherapy , 3-Iodobenzylguanidine , Biomarkers, Tumor/analysis , Child, Preschool , Combined Modality Therapy , Evaluation Studies as Topic , Female , Humans , Male , Neuroblastoma/drug therapy , Neuroblastoma/pathology , Palliative Care , Remission Induction
12.
Nuklearmedizin ; 24(1): 29-34, 1985 Feb.
Article in German | MEDLINE | ID: mdl-2987887

ABSTRACT

Overview on informations which are necessary to interpret MRI and MRS. The approach is related rather to application than it is a physical one. The central steps in comprehending MR are presented, e.g. frequency decomposition in order to obtain local information with MRI or chemical information with MRS, the spin echo in order to differentiate instrumental dephasation from dephasation by molecular interference, perfusion in MRI, and the components of sensitivity in measuring different nuclei etc. The report terminology is based on the description of grey scale pictures, but one has to consider that the information is not one-dimensional but multiparametric. Therefore new terms have to be developed, a problem similar to that of describing scintigraphic time sequences in nuclear medicine.


Subject(s)
Magnetic Resonance Spectroscopy , Electron Spin Resonance Spectroscopy , Magnetic Resonance Spectroscopy/methods , Physical Phenomena , Physics , Terminology as Topic
13.
Nuklearmedizin ; 24(1): 12-5, 1985 Feb.
Article in German | MEDLINE | ID: mdl-4000976

ABSTRACT

Coded apertures supply a decoupling of resolution and sensitivity in scintigraphic imaging. The reconstructed images are focussed on different planes. The approach presented replaces the conventional collimator by three Fresnel zone plates in order to simulate a complex projection. The theoretical advantages of scintigraphy with coded apertures could be demonstrated in thyroid imaging. Unresolved artifacts and the lack of availability impair its routine use.


Subject(s)
Radionuclide Imaging/instrumentation , Thyroid Gland/diagnostic imaging , Humans , Mathematics , Models, Structural , Thyroid Diseases/diagnostic imaging
14.
Nuklearmedizin ; 24(1): 16-7, 1985 Feb.
Article in German | MEDLINE | ID: mdl-3873646

ABSTRACT

A new method of processing SPECT of 201T1 myocardial images is demonstrated based on the idea that 3-dimensional myocardium might be a curved area which can be presented in an unfolded form as a single planar image. An example of the procedure including parametric pictures is demonstrated.


Subject(s)
Heart/diagnostic imaging , Radioisotopes , Thallium , Tomography, Emission-Computed/methods , Female , Heart Ventricles/diagnostic imaging , Humans , Image Enhancement/methods , Myocardial Infarction/diagnostic imaging , Time Factors
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