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Background Vitamin D insufficiency is common in pregnant women worldwide. Regular prenatal exercise is considered beneficial for maternal and fetal health. There is a knowledge gap regarding the impact of prenatal exercise on maternal vitamin D levels. The objective of this study was to investigate whether a prenatal exercise program influenced serum levels of total, free and bioavailable 25-hydroxyvitamin D (25(OH)D) and related parameters. This is a post hoc analysis of a randomized controlled trial with gestational diabetes as the primary outcome. Methods Healthy, pregnant women from two Norwegian cities (Trondheim and Stavanger) were randomly assigned to a 12-week moderate-intensity exercise program (Borg perceived rating scale 13–14) or standard prenatal care. The intervention group (n = 429) underwent exercise at least three times weekly; one supervised group training and two home based sessions. The controls (n = 426) received standard prenatal care, and exercising was not denied. Training diaries and group training was used to promote compliance and evaluate adherence. Serum levels of 25(OH)D, parathyroid hormone, calcium, phosphate, magnesium and vitamin D-binding protein were measured before (18–22 weeks′ gestation) and after the intervention (32–36 weeks′ gestation). Free and bioavailable 25(OH)D concentrations were calculated. Regression analysis of covariance (ANCOVA) was applied to assess the effect of the training regime on each substance with pre-intervention levels as covariates. In a second model, we also adjusted for study site and sampling month. Intention-to-treat principle was used. Results A total of 724 women completed the study. No between-group difference in serum 25(OH)D and related parameters was identified by ANCOVA using baseline serum levels as covariates. The second model revealed a between-group difference in levels of 25(OH)D (1.9, 95% CI 0.0 to 3.8 nmol/L; p = 0.048), free 25(OH)D (0.55, 95% CI 0.10 to 0.99 pmol/L; p = 0.017) and bioavailable 25(OH)D (0.15 95% CI 0.01 to 0.29 nmol/L; p = 0.036). No serious adverse events related to regular exercise were seen. Conclusion This study, a post hoc analysis, indicates that exercise may affect vitamin D status positively, and emphasizes that women with uncomplicated pregnancies should be encouraged to perform regular exercise. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Aims Labour market marginalisation (LMM), i.e. severe problems in finding and keeping a job, is common among young adults with attention-deficit/hyperactivity disorder (ADHD). This study aimed to disentangle the extent of LMM as well as the heterogeneity in patterns of LMM among young adults with ADHD and what characterises those belonging to these distinct trajectories of LMM. Methods This population-based register study investigated all 6287 young adults, aged 22–29 years, who had their first primary or secondary diagnosis of ADHD in Sweden between 2006 and 2011. Group-based trajectory (GBT) models were used to estimate trajectories of LMM, conceptualised as both unemployment and work disability, 3 years before and 5 years after the year of an incident diagnosis of ADHD. Odds ratios (ORs) with 95% confidence intervals (CIs) for the association between individual characteristics and the trajectory groups of LMM were estimated by multinomial logistic regression. Results Six distinct trajectories of LMM were found: ‘increasing high’ (21% belonged to this trajectory group) with high levels of LMM throughout the study period, ‘rapidly increasing’ (19%), ‘moderately increasing’ (21%), ‘constant low’ (12%) with low levels of LMM throughout the study period, ‘moderately decreasing’ (14%) and finally ‘fluctuating’ (13%), following a reversed u-shaped curve. Individuals with the following characteristics had an increased probability of belonging to trajectory groups of increasing LMM: low educational level (moderately increasing: OR: 1.4; CI: 1.2–1.8, rapidly increasing: OR: 1.7; CI: 1.3–2.1, increasing high: OR: 2.9; CI: 2.3–3.6), single parents (moderately increasing: OR: 1.6; CI: 1.1–2.4, rapidly increasing: OR: 2.0; CI: 1.3–3.0), those born outside the European Union/the Nordic countries (rapidly increasing: OR: 1.7; CI: 1.1–2.5, increasing high: OR: 2.1; CI: 1.4–3.1), persons living in small cities/villages (moderately increasing: OR: 2.4; CI: 1.9–3.0, rapidly increasing: OR: 2.1; CI: 1.6–2.7, increasing high: OR: 2.6; CI: 2.0–3.3) and those with comorbid mental disorders, most pronounced regarding schizophrenia/psychoses (rapidly increasing: OR: 6.7; CI: 2.9–19.5, increasing high: OR: 12.8; CI: 5.5–37.0), autism spectrum disorders (rapidly increasing: OR: 4.6; CI: 3.1–7.1, increasing high: OR: 9.6; CI: 6.5–14.6), anxiety/stress-related disorders (moderately increasing: OR: 1.3; CI: 1.1–1.7, rapidly increasing: OR: 2.0; CI: 1.6–2.5, increasing high: OR: 1.8; CI: 1.5–2.3) and depression/bipolar disorder (moderately increasing: OR: 1.3; CI: 1.0–1.6, rapidly increasing: OR: 1.7; CI: 1.4–2.2, increasing high: OR: 1.5; CI: 1.2–1.9). Conclusions About 61% of young adults were characterised by increasing LMM after a diagnosis of ADHD. To avoid marginalisation, attention should especially be given to young adults diagnosed with ADHD with a low educational level, that are single parents and who are living outside big cities. Also, young adults with comorbid mental disorders should be monitored for LMM early in working life.

Accurate 3D object detection (3DOD) is crucial for safe navigation of complex environments by autonomous robots. Regressing accurate 3D bounding boxes in cluttered environments based on sparse LiDAR data is however a highly challenging problem. We address this task by exploring recent advances in conditional energy-based models (EBMs) for probabilistic regression. While methods employing EBMs for regression have demonstrated impressive performance on 2D object detection in images, these techniques are not directly applicable to 3D bounding boxes. In this work, we therefore design a differentiable pooling operator for 3D bounding boxes, serving as the core module of our EBM network. We further integrate this general approach into the state-of-the-art 3D object detector SA-SSD. On the KITTI dataset, our proposed approach consistently outperforms the SA-SSD baseline across all 3DOD metrics, demonstrating the potential of EBM-based regression for highly accurate 3DOD. Code is available at https://github.com/fregu856/ebms_3dod., Code is available at https://github.com/fregu856/ebms_3dod

This paper is directed towards the problem of learning nonlinear ARX models based on observed input-output data. In particular, our interest is in learning a conditional distribution of the current output based on a finite window of past inputs and outputs. To achieve this, we consider the use of so-called energy-based models, which have been developed in allied fields for learning unknown distributions based on data. This energy-based model relies on a general function to describe the distribution, and here we consider a deep neural network for this purpose. The primary benefit of this approach is that it is capable of learning both simple and highly complex noise models, which we demonstrate on simulated and experimental data.

Allergic disorders, characterized by Th2 immune responses to environmental substances, are increasingly common in children in Western societies. Multiple studies indicate that breastfeeding, early complementary introduction of food allergens, and antibiotic avoidance in the first year of life reduces allergic outcomes in at-risk children. Why the benefit of these practices is restricted to early life is largely unknown. We identified a preweaning interval during which dietary antigens are assimilated by the colonic immune system. This interval is under maternal control via temporal changes in breast milk, coincides with an influx of naive T cells into the colon, and is followed by the development of a long-lived population of colonic peripherally derived Tregs (pTregs) that can be specific for dietary antigens encountered during this interval. Desynchronization of mothers and offspring produced durable deficits in these pTregs, impaired tolerance to dietary antigens introduced during and after this preweaning interval, and resulted in spontaneous Th2 responses. These effects could be rescued by pTregs from the periweaning colon or by Tregs generated in vitro using periweaning colonic antigen-presenting cells. These findings demonstrate that mothers and their offspring are synchronized for the development of a balanced immune system.

While deep neural networks have become the go-to approach in computer vision, the vast majority of these models fail to properly capture the uncertainty inherent in their predictions. Estimating this predictive uncertainty can be crucial, for example in automotive applications. In Bayesian deep learning, predictive uncertainty is commonly decomposed into the distinct types of aleatoric and epistemic uncertainty. The former can be estimated by letting a neural network output the parameters of a certain probability distribution. Epistemic uncertainty estimation is a more challenging problem, and while different scalable methods recently have emerged, no extensive comparison has been performed in a real-world setting. We therefore accept this task and propose a comprehensive evaluation framework for scalable epistemic uncertainty estimation methods in deep learning. Our proposed framework is specifically designed to test the robustness required in real-world computer vision applications. We also apply this framework to provide the first properly extensive and conclusive comparison of the two current state-of-the-art scalable methods: ensembling and MC-dropout. Our comparison demonstrates that ensembling consistently provides more reliable and practically useful uncertainty estimates. Code is available at https://github.com/fregu856/evaluating_bdl., Comment: CVPR Workshops 2020. Code is available at https://github.com/fregu856/evaluating_bdl

Objective To assess the association between levels of vitamin D and urinary incontinence (UI) in pregnancy. Design A cross‐sectional study. Secondary analysis of a randomised controlled trial. Setting Two university hospitals in Norway. Population A total of 851 healthy, pregnant women >18 years in gestational weeks 18–22 with a singleton live fetus. Methods Data on UI were collected from a questionnaire at inclusion and serum analysis of 25‐hydroxy vitamin D (25(OH)D) was performed. Univariable and multivariable logistic regression analyses were applied to study associations between exposure and outcomes. Main outcome measures Prevalence of self‐reported UI, stress (SUI) and urge (UUI) or mixed UI. Results In total, 230/851 (27%) of the participants were vitamin D insufficient (25(OH)D

The Visual Object Tracking challenge VOT2020 is the eighth annual tracker benchmarking activity organized by the VOT initiative. Results of 58 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The VOT2020 challenge was composed of five sub-challenges focusing on different tracking domains: (i) VOT-ST2020 challenge focused on short-term tracking in RGB, (ii) VOT-RT2020 challenge focused on “real-time” short-term tracking in RGB, (iii) VOT-LT2020 focused on long-term tracking namely coping with target disappearance and reappearance, (iv) VOT-RGBT2020 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2020 challenge focused on long-term tracking in RGB and depth imagery. Only the VOT-ST2020 datasets were refreshed. A significant novelty is introduction of a new VOT short-term tracking evaluation methodology, and introduction of segmentation ground truth in the VOT-ST2020 challenge – bounding boxes will no longer be used in the VOT-ST challenges. A new VOT Python toolkit that implements all these novelites was introduced. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website (http://votchallenge.net).

While deep learning-based classification is generally tackled using standardized approaches, a wide variety of techniques are employed for regression. In computer vision, one particularly popular such technique is that of confidence-based regression, which entails predicting a confidence value for each input-target pair (x, y). While this approach has demonstrated impressive results, it requires important task-dependent design choices, and the predicted confidences lack a natural probabilistic meaning. We address these issues by proposing a general and conceptually simple regression method with a clear probabilistic interpretation. In our proposed approach, we create an energy-based model of the conditional target density p(y|x), using a deep neural network to predict the un-normalized density from (x, y). This model of p(y|x) is trained by directly minimizing the associated negative log-likelihood, approximated using Monte Carlo sampling. We perform comprehensive experiments on four computer vision regression tasks. Our approach outperforms direct regression, as well as other probabilistic and confidence-based methods. Notably, our model achieves a \(2.2\%\) AP improvement over Faster-RCNN for object detection on the COCO dataset, and sets a new state-of-the-art on visual tracking when applied for bounding box estimation. In contrast to confidence-based methods, our approach is also shown to be directly applicable to more general tasks such as age and head-pose estimation. Code is available at https://github.com/fregu856/ebms_regression.

Background Assessing risk of Crohn’s disease (CD) recurrence following ileocolic resection (ICR) is necessary to optimize medical management and prevent long-term complications. This study aimed to identify noninvasive markers that could predict postoperative disease activity. Methods Inclusion criteria were a diagnosis of CD, first ICR, interval colonoscopy, and whole transcriptome array meeting quality control standards. Demographic and clinical data were obtained from the electronic medical record. RNA extraction and human transcriptome microarray were performed on noninflamed ileal margins from operative specimens. Clinical data and random forest were analyzed in R. Principal components analysis, hierarchical clustering, and pathway enrichment were performed in Partek. Results Sixty-five patients completed the study, and 5 were excluded from analysis due to extreme variability on whole transcriptome analysis. Unsupervised hierarchical clustering revealed that patients with an i0 Rutgeerts score generally segregated from all others. In anti-TNF-naïve patients, unsupervised hierarchical clustering revealed complete segregation of patients with an i0 score. Reduced escalation in therapy and continued mucosal remission, consistent with indolent disease, were seen in the 4 years following surgery. Random forest identified 30 transcripts differentiating i0 patients from the other groups. Pathway enrichment highlighted toll-like receptor, NOD-like receptor, and TNF signaling. This transcriptome signature did not identify i0 anti-TNF-exposed patients. However, anti-TNF-exposed patients with indolent postoperative courses were found to have a transcriptome signature distinct from those with aggressive disease. Conclusions Anti-TNF-naïve and -exposed patients have unique expression profiles at the time of surgery, which may offer predictive value in assessing the risk of nonrecurrence.

Objective To investigate whether a customised exercise programme influences pregnant women's psychological wellbeing and general health perception reflecting health-related quality of life (HRQoL) in late pregnancy. Design A two-armed, two-centred randomised controlled trial. Setting Trondheim and Stavanger University Hospitals, Norway. Population A total of 855 healthy Caucasian pregnant women. Methods The intervention group was offered a 12-week exercise programme between 20 and 36 weeks of pregnancy. One weekly group session was led by physiotherapists, in addition women were encouraged to follow a home exercise programme at least twice a week. The exercise programme followed standard recommendations and included both aerobic and strength training. The control group received regular antenatal care. Pretests and post-tests were performed at 18–22 and 32–36 weeks of pregnancy. Main outcome measures In the original study primary outcome was gestational diabetes mellitus, but in this report the primary outcome is HRQoL. The questionnaire Psychological General Wellbeing Index (PGWBI) was used to assess psychological wellbeing and self-perceived general health before and after the intervention. PGWBI contains six subscales and it is also possible to summarise all items to a global score. Results No association between antenatal exercise programme allocation and PGWBI (global score and subscales) was found. The study population was homogeneous and had high educational level. Conclusions The results indicate that offering women an exercise programme during pregnancy does not seem to influence healthy pregnant women's psychological wellbeing and self-perceived general health. Further research is needed to investigate the effects of exercise in pregnancy on psychological wellbeing and self-perceived general health among women from different sociocultural subgroups. Tweetable abstract Exercise in pregnancy does not influence healthy pregnant women's health-related quality of life.

Background Since 1996, ABO- incompatible heart transplants have been undertaken by carrying out a whole body plasma exchange to remove isohaemagglutinins using the cardiopulmonary bypass circuit at the time of transplantation. However, this requires large volumes of donated blood and blood products, causes haemodynamic instability during the exchange transfusion and limits the practical usage to small children. We sought to determine the efficacy of anti-A/B immunoadsorption within the cardiopulmonary bypass circuit on removal of isohaemagglutinins in an ex vivo setting. Methods An anti-A/B immunoadsorption column was placed into a CPB circuit mimicking a typical ABO-incompatible transplant patient, which had been primed with group O whole human blood. Samples were taken for determination of isohaemagglutinin titres following each plasma volume pass through the anti-A/B immunoadsorption column. Results There was a linear decrease of at least one dilution seen in both anti-A and -B IgG and IgM antibodies with each plasma volume pass through the column. This predictable removal allowed the formulation of selection criteria for ABO-incompatible heart transplantation given the reciprocal of titre and patient weight. Conclusions The incorporation of an anti-A/B immunoadsorption column into the extracorporeal circuit reduces the allogeneic blood product requirement for ABO-incompatible heart transplantation whilst providing efficacious removal of anti-A and anti-B isohaemagglutinins. Furthermore, this can be undertaken within the time period of cardiopulmonary bypass before graft reperfusion and expands the potential recipient pool to larger patients with higher isohaemagglutinin titres. Further work is now planned to examine the possibility of utilising similar technology for HLA-incompatible heart transplants, and to create a 3rd generation cloud–based transplant registry that will link outcomes, genetics and antibody profiles from centres Worldwide.

Background One of the hallmarks of acute colitis is loss of epithelial transport. For unknown reasons, many patients still suffer from GI symptoms during remission, indicating a sustained imbalance between absorption and secretion. We hypothesize that the colonic epithelium becomes more reactive to secretagogues to compensate for a failing barrier. Methods Biopsies from ascending colon and sigmoid colon of UC patients in remission and controls were mounted in Ussing chambers. Membrane current (Im) and epithelial capacitance (Cp) were used as markers for anion secretion and mucus exocytosis. Carbachol (1 mmol L−1) and forskolin (10 μmol L−1) were used to study Ca2+ and cAMP-mediated secretion. Key Results Baseline values showed segmental patterns with higher Im in ascending colon and higher Cp in sigmoid colon of both UC patients and controls, but the patterns did not differ between the groups. The Im response to forskolin was increased (+35%) in the ascending colon of UC patients and the Im response to carbachol was decreased (−40%) in the same segment. No group differences were seen in the distal colon for either the forskolin or carbachol-induced Im responses. The Cp response to carbachol was instead up-regulated in the distal colon of UC patients, but remained unaffected in the proximal colon. Conclusions & Inferences The proximal colonic mucosa of UC patients in remission seems to shift its reactivity to secretagogues, becoming more sensitive to cAMP-dependent secretion and less sensitive to Ca2+-dependent secretion. This phenomenon may contribute to residual diarrhea in this patient group, despite resolution of inflammation.

Irritable bowel syndrome (IBS) is often seen in women, and symptom severity is known to vary over the menstrual cycle. In addition, activation of the hypothalamic-pituitary-adrenal (HPA) axis enhances symptomology and patients with IBS have increased activation of the amygdala, a brain region known to facilitate HPA output. However, little is known about the effects of amygdala activation during different stages of the menstrual cycle. We therefore investigated the effects of amygdala activation on somatic and visceral pain perception over the rat estrous cycle. Female Wistar rats were implanted with either corticosterone (Cort) or cholesterol as a control onto the dorsal margin of the central amygdala. Visceral sensitivity was quantified by recording the visceromotor response (VMR) to colorectal distension (CRD) and somatic sensitivity was assessed via the Von Frey test. In cholesterol controls, both visceral and somatic sensitivity varied over the estrous cycle. Rats in proestrus/estrus responded to CRD with an increased VMR compared with rats in metestrus/diestrus. Somatic sensitivity followed a similar pattern with enhanced sensitivity during proestrus/estrus compared with metestrus/diestrus. Elevated amygdala Cort induced visceral hypersensitivity during metestrus/diestrus but had no effect during proestrus/estrus. In contrast, elevated amygdala Cort increased somatic sensitivity during both metestrus/diestrus and proestrus/estrous. These results suggests that amygdala activation by Cort eliminates spontaneously occurring differences in visceral and somatic pain perception, which could explain the lowered pain thresholds and higher incidence of somatic pain observed in women with IBS.

To ensure optimal calcium accrual in the fetal skeleton, a substantial rise occurs in 1,25-dihydroxyvitamin D (1,25(OH)2D), but is dependent on sufficient 25-hydroxyvitamin (25(OH)D). Large longitudinal studies addressing free 25(OH)D and 1,25(OH)2D during pregnancy are scarce. We aimed to assess levels of and relationship between 25(OH)D, 1,25(OH)2D, vitamin D-binding protein (DBP), parathyroid hormone (PTH), and free 25(OH)D during pregnancy; determinants of vitamin D status; and association between vitamin D indices or PTH and pregnancy outcomes (gestational diabetes mellitus and birthweight). Altogether 855 pregnant Norwegian Caucasian women from Trondheim and Stavanger (latitude 63°N and 58°N) were recruited; 94 were lost to follow-up. The study was originally a randomized controlled trial (2007–2009) with gestational diabetes as primary outcome. Data were collected in second and third trimester. In third trimester, 246 (34%) had vitamin D insufficiency and 52 (7%) deficiency (25(OH)D

Food safety is an increasing problem in relation to vegetables, regarding both ready-to-eat produces, such as leafy salad, spinach and fruit as well as frozen produces that have not been exposed to pasteurization prior to freezing. Contamination may occur during the entire production chain. However, in connection with invasive enteric pathogens, slurry, farmyard manure, sewage sludge and irrigation water have been highlighted as potential sources for pathogen dispersal. Especially, the dispersal of Escherichia coli O157:H7 and Salmonella spp. is a considerable threat. An increasing number of outbreaks have been reported. To prevent the spread of invasive enteric bacteria by irrigation water, water sources, such as well water as well as community potable water have been proposed. The present paper describes pathogens of significance that may be spread by irrigation water supplied to field vegetables and presents some recent results on survival of human pathogens in water, soil and on vegetables. The current status of standards for microbiological quality of irrigation water to fresh or minimally processed fruit and vegetables is discussed.

The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW(TM) 6.1 under Windows 2000(TM). About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle(TM) database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure. (C) 2004 Elsevier B.V. All rights reserved.

A multimodel controller design procedure based on robust LQ design is evaluated for a highly nonlinear chemical process. The procedure is combined with two gain-scheduling methods: a fixed robust controller with scheduled output gain, and complete scheduling of locally optimal controllers. The performances obtained with the fixed controller, the gain scheduled controllers and conventional PID control are compared and tested on a simulated pH neutralization process.

An explant tissue system for the study and recording of mucus secretion has been developed. Human colon biopsies or tissue from experimental animals are mounted in a horizontal perfusion chamber and the mucus accumulated on the apical side is observed and measured.

The transmission grids have an important role in the development of the internal electricity market, and as a tool to fulfil EU:s ambitious energy policy, known as 20-20-20 in 2020. The key issue is how to get the national TSOs to broaden their scope in order to realize the full potential of trade across borders. The TSOs need to get the incentives to take an active part in the foreseen structural change in electricity generation, which will require actions both nationally and across borders. In this paper we focus on the importance of a broadened international scope when planning the future development of the European transmission grids. We exemplify our choice of method by some empirical findings from the Nordic electricity market.

The important role of the transmission infrastructure in the development of the internal electricity market is the main issue in this paper. The key question is how to get the former national entities to broaden their scope, thus including the values that trades across former ldquoclosedrdquo borders may realize into the decisions of operations and planning. Further, we discuss the institutional setting in information disclosure and procedures for choosing infrastructure projects in a manner that consistently can reduce regulatory risks for stakeholders other than the transmission system operator (TSO). We try to exemplify the importance and tools of changing governance, making it aimed at accommodating a path towards the sustainable integrated European electricity market.

The dynamic nuclear polarization (DNP) of (LiD)-Li-6 requires 1 mW/g or more microwave power in the beginning of the process. With the material of 350 g, this gives more than 350 mW in total for the COMPASS polarized target. A temperature around 300 mK or below is needed for an efficient polarization. These low temperatures can only be achieved with a dilution refrigerator designed to operate with a He-3 flow of 100 mmol/s. In order to keep the polarization in the frozen mode, temperatures of about 65 mK are used with typical magnetic relaxation times of more than 1400 h at 0.42 T and of more than 15 000 h at 2.5 T. Low lattice temperature is important in achieving high nuclear polarization. The base temperature is limited by the heat brought to the mixing chamber by the inlet 3 He and by radiation and conduction of heat. (C) 2004 Elsevier B.V. All rights reserved.

The choice of high pin count ASIC packages has a major impact on the total cost and performance of the whole packaging system. Six different types of ASIC packages have been compared with respect to production aspects, availability, reliability, thermal and electrical properties and cost. Recommendations for the proper choice of packages for different types of applications are given. All packages have been directly assembled to PWBs in order to study problems with handling, solder process, testing and repairability. Some of the assembled packages have been temperature cycled in order to test the solder joint reliability. The pin grid array packages are the most frequently used high pin count packages today. However, they are expensive and through‐hole mounting reduces the routing capability of the board. Pad area array packages are a hermetic alternative with a lower price for the package as well as very good thermal and electrical properties, but they need to be mounted on expensive PWBs. Another surface mountable package which is hermetic is the ceramic leaded chip carrier with fine lead pitch. This package is even more expensive than the pin grid array package and is difficult to handle. In the future, non‐hermetic alternatives will probably predominate. Plastic quad flat pack and TapePak can be used below 160–180 leads, while direct assembled TAB would be the best alternative for very high pin counts. Before one can use non‐hermetic packages in telecom products, a large qualification programme must be performed to evaluate the long‐term reliability.

Calibration errors are the dominant error source for direction finding (DF) from airborne platforms. Calibration of the array manifold is done with the wings in an unknown position. Wing movements during flight perturbs the array manifold from its calibrated value, causing errors in the direction finding. We present a direction finding algorithm that compensates for variations in wing flexure. The algorithm relies on a physically motivated model that captures the gross behavior of the manifold perturbations. The model has been validated using experiments on a model aircraft in an anechoic chamber. The structure of the model can be exploited in estimation schemes such as weighted subspace fitting (WSF), leading to improved DF accuracy. With the correct model parameters, the effect of the manifold perturbation is, in fact, fully neutralized. The properties of the new scheme are demonstrated through analysis and simulation. >

Increased throughput and flexibility requirements in large-scale electronic equipment create needs for increased interconnection density capacity and re-configurability. The growing demand for new broadband interactive telecom and computer services is expected to enforce this development, which presents a challenge to traditional electronic interconnection techniques and an opportunity for new optical solutions, provided that the cost of introduction of the optical technology is affordable for both system operators and service users. The authors describe a complete sub-system of parallel optical interconnects (i.e., a total solution including the link itself and the equipment practice supporting the link) which exhibits both cost and performance benefits compared to a pure electrical or a serial optical solution.

It is pointed out that the telecom system performance can be improved by the use of MCM (multichip modules) technology. Better signal transmission properties, lower power dissipation (if CMOS chips are used), and decreased physical volume will be obtained. Today MCM is an expensive technique, but a cost analysis shows that it has the potential of becoming more cost effective than the standard technique of using single-chip packages. It can also become more cost effective to use the MCM technique rather than increase the number of gates on the silicon chip over a certain level. In order to study the properties of the MCM technology, a project has been started at Ericsson Telecom in which a processor application is built up on three different types of MCM substrates. >

System performance can be improved by the use of MCM (multi‐chip module) technology. Better signal transmission properties, lower power dissipation if C‐MOS chips are used and decreased physical volume will be obtained. Today MCM is an expensive technique, but the authors' cost analysis shows that it has the potential to become more cost‐effective than the standard technique of using single chip packages. It can also become more cost‐effective to use the MCM technique than to increase the number of gates on the silicon chip over a certain level. In order to study the properties of MCM technology, a project has been started at the authors' company in which a processor application is built up on three different types of MCM substrates.

There are a number of potentially powerful applications where light modulators can be useful, depending on the ability to produce miniature, inexpensive, high accuracy, high reliability modulators integrated with electronic circuitry. The authors discuss a silicon-based micromechanical light modulator that has been developed. Micromechanical fabrication technology in silicon, compatible with silicon circuit technology, has been used. A comparison of the modelled and the experimentally measured characteristics of the micromechanical light modulator is presented, and potential applications are given.

Fibre-optic sensors are examined from a micro-mechanical viewpoint. Theoretical expressions for the signal modulation of three basic designs are given, showing the relationship of geometrical parameters and optical transmission properties of multimode fibres. Intensity modulation is considered, together with various compensation schemes. The possibility of designing sensors with frequency output is pointed out. Design examples are given, together with measured performance data on sensor prototypes. One pressure sensor having an outer diameter of less than 0.5 mm for biomedical applications has been fabricated using silicon micro-machining. Another fibre-optic pressure sensor for industrial applications is described. Finally, a fibre-optic voltmeter based on a micro-mechanical light scanning element is described.

Activity in computer-monitored running wheels, behavior in open-field tests, body temperature measured by rectal probe, and vocalization were examined in rats after a single injection of 2.5 g/kg ethanol or saline. A reduction in running-wheel activity occurred during intoxication, followed by a significant increase in running 20-24 hr after the injection. Also 24 hr after ethanol, among rats kept in normal cages, there was an increase in body temperature and vocalization and a decrease in ambulation in a dark, quiet open field. Each of these 3 aftereffects was reduced or abolished in the rats with access to a running wheel. The results confirm and extend previous findings of aftereffects of acute intoxication in rats with a time course similar to hangover in humans.