Interference-aware scheduling in the multiuser MIMO-OFDM downlink - [topics in radio communications]

With the introduction of orthogonal frequency- division multiplexing and multiple antennas in cellular networks, there are new opportunities to adapt the transmission to propagation and interference conditions. In this article we describe a practical approach using space-frequency-selective multiuser MIMO scheduling. Frequency-selective feedback is provided on achievable data rates for preferred single- and multistream transmission modes. The base station selects the best mode while providing instantaneous fairness. We observe that multiuser transmission increases the probability of using multistream transmission. Besides the benefits from optimal combining at the physical layer, there is an additional gain at the MAC layer since the estimation of achievable rates becomes more precise. Altogether, 93 percent of the theoretical throughput can be realized by synchronizing the base stations and providing cell-specific reference signals. We have implemented essential functions of the approach in real time on an experimental 3GPP LTE prototype in 20 MHz bandwidth. Feasibility of the key features is proven in laboratory and field trials.     

Quality assurance of psychiatric consultations in somatic hospitals

Research has shown great variety in the clinical practice of consultation-liaison psychiatry in and between different countries. This paper presents the Norwegian experiences from a European collaborative study of quality management in consultation-liaison psychiatry. We describe a dynamic model for total quality management based on regular registration of some clinical data and the subsequent feed-back on changes of these. We discuss our experiences with this model and obstacles met in everyday work. Finally we point to different ways of implementing this method on a broader base in consultation-liaison psychiatry.     

The evolutionary relationship among Caucasian MS patients and controls

Previous observations suggest that the mitochondrial (mt)DNA may confer susceptibility to multiple sclerosis (MS). However, the proportion of affected individuals and the range of contributing mtDNA abnormalities are unknown. To help clarify this question, we analyzed the first hypervariable D-loop sequences of the mtDNA in a group of randomly selected Caucasian MS patients, in MS patients with prominent optic neuritis (PON) and in controls. Phylogenetic analysis of these D-loop sequences revealed that individuals in both groups of patients are generally scattered in the Caucasian phylogeny. However, a small cluster of unrelated MS patients identified by this analysis suggests that a maternal lineage with MS relevant mtDNA sequences may exist, and merits a more comprehensive study.     

Fenfluramine and idiopathic pain: a serotonergic study in non-psychiatric patients with functional gastrointestinal disorder

BACKGROUND: We investigated prolactin and cortisol response to fenfluramine in non-psychiatric patients with chronic functional gastrointestinal disorder (FGD). METHODS: Sixty milligrams fenfluramine was given orally to 55 subjects without any DSM-III axis-1 psychopathology and 29 healthy control subjects matched for sex and age. Serum cortisol and prolactin levels were analysed at base line and after 120, 180, and 240 min. RESULTS: Fenfluramine challenge induced an increase in mean prolactin and cortisol serum values in both patients and controls. Female patients showed lower base-line values of prolactin and higher delta values of cortisol than controls. Male patients and controls showed very uniform values for all variables. Length of illness history influenced delta cortisol values in both sexes. CONCLUSIONS: The cortisol and prolactin responses to fenfluramine suggest a psychobiologic gender difference with a possible stress-induced central serotonergic dysfunction in female patients but not in male patients. The close relationship between length of illness and delta cortisol may also suggest an increased state of distress in females with chronic functional gastrointestinal disorder.     

Stool bacterial aerobic overgrowth in the small intestine of children with acute diarrhoea

The aerobic flora of 2 groups of children (normal and with malnutrition) with acute diarrhoea was studied, by intubation of the upper and middle small intestine and by stool culture. All the 27 children studied presented bacterial concentrations of 10(5) germs/ml at one or both levels studied. In 9 cases enteropathogen bacteria e were isolated from stools, and in 6 of these they were also found in the small intestine. The results show the elevated incidence of overgrowth of the small intestinal aerobic flora in children with acute diarrhoea. This fact is mentioned as another etiological factor to be taken into consideration in this pathology.     

Rocket immunoelectrophoresis (RIE) for determination of potentially allergenic peanut proteins in processed foods as a simple means for quality assurance and food safety

 Peanuts are one of the most allergenic foods known. The presence of hidden allergens in processed food for reasons of mislabelling or cross-contamination expose allergic individuals to unpredictable risks, especially since highly sensitized subjects may experience severe anaphylactic reactions. The protection of consumers requires specific and sensitive methods for the detection of trace amounts of potentially allergenic peanut components. A rocket immunoelectrophoresis (RIE) procedure was developed allowing the detection of even spurious contaminations with peanut protein. For precipitation of peanut protein a commercially available antiserum was used. By amplifying precipitates with a secondary immunodetection step, 20 ng/ml peanut protein in chocolate extract, equivalent to 0.0002% peanut in chocolate, could still be detected. Model chocolate spiked with various amounts of peanut was investigated down to 0.001% peanut (10 ppm), the limit of quantitative determination. The method was optimized for detection of peanut in chocolate samples. Non-chocolate samples had to be standardized with a chocolate matrix prior to analysis in order to obtain a uniform response. Cross-reactivities with other food proteins did not occur. The method showed high recoveries of 85–101% for chocolate samples down to 10 ppm peanut and good reproducibility with coefficients of variation of ≤ 5 % for samples of ≥ 15 ppm peanut protein. The applicability of this method in the detection of peanut protein in various food commodities was demonstrated: two unlabelled products and two products which did not have peanut listed as an ingredient were identified as containing peanut protein. In all cases where peanut was listed, peanut protein could be determined. The results of RIE were always confirmed by those of a new cell-mediator-release assay that is based on a rat basophil leukaemia (RBL) cell-line (RBL-2H3), cells that are a functional equivalent to mucosal mast cells. Measuring the release of β-hexosaminidase resulting from cross-linking of basophil-bound peanut-specific immunoglobulin E, the assay mimics a main event of the allergic type-I reaction. The cell assay was adapted for food matrices and peanut could be detected down to 0.01% which additionally demonstrated in vitro that even trace amounts of peanut protein could elicit allergic reactions. Received: 28 May 1997 / Revised version: 11 July 1997     

Challenge of BALB/c mice with respiratory syncytial virus does not enhance the Th2 pathway induced after immunization with a recombinant G fusion protein, BBG2NA, in aluminum hydroxide

The polypeptide of aa 130-230 of the G protein (G2Na) of respiratory syncytial virus (RSV) was fused to BB, the albumin-binding region of streptococcal G protein, producing BBG2Na, which induced protective immune responses in rodent models. Evaluation of the immune response in mice immunized with BBG2Na in the adjuvant alhydrogel revealed high amounts of interleukin (IL)-5 and some IL-4 in splenocytes restimulated in vitro. This is compatible with a Th2 response. The activation of the Th2 pathway in such mice was further supported by the detection of IL-5 and G2Na-specific IgE in vivo. Of interest, in contrast to immunization with formalin-inactivated RSV, immunization of mice with BBG2Na followed by intranasal RSV challenge did not lead to increased production of IL-5- or G2Na-specific IgE. However, IgG1- and IgG2a-specific antibodies were boosted. These results demonstrate that the Th2 pathway is not enhanced by RSV challenge in BBG2Na-immunized mice.     

The ECLW Collaborative Study: III. Training and reliability of ICD-10 psychiatric diagnoses in the general hospital setting--an investigation of 220 consultants from 14 European countries. European Consultation Liaison Workgroup

A comprehensive training program for reliable use of the ICD/10 in Consultation-Liaison (C-L) psychiatry was conducted with 220 psychiatrists and psychologists from 14 European countries. The training included rating of written test cases and development of a coding manual to avoid diagnostic pitfalls not addressed in the ICD-10 manual. Following this training, all consultants rated 13 written case histories. One hundred sixty-seven consultants (76%) had a kappa (kappa) of at least 0.70. Only 13 (6%) had a kappa 0.40. The percentage of high reliability raters was evenly distributed among the different countries. Consultants had some problems in the differentiation between adjustment disorders and depressive disorders, and in the classification of disorders where ICD-10 differs from the DSM-III-R system. National biases in diagnostic practice were found with regard to the "case" concept and the role of alcohol in confusional states. Finnish consultants coded "no psychiatric disorder" significantly more often, whereas German and Italian consultants attributed delirious state more often to alcohol than consultants from other European countries. The study demonstrates that it is possible to achieve acceptable interrater reliability in applying the ICD-10 guidelines, through training programs designed for C-L psychiatrists and psychologists. Nevertheless, this first cross-national study shows the importance of addressing differences in national diagnostic practice.