Some Insights into MIMO Mutual Information: The High SNR Case

We consider mutual information of multiple-input multiple-output (MIMO) wireless channels with complex isotropic Gaussian input in the case where the receiver has perfect channel, knowledge. For arbitrary fading statistics, a mutual information lower bound is decomposed in a sum of three terms involving: a) average SNR; b) channel fading; and c) a term characterizing the "effective rank", or eigenvalue dispersion, of the channel matrix. The decomposition suggests that spatial multiplexing efficiency of a MIMO channel can be characterized by the so-called ellipticity statistic. Distribution functions, means and variances of the random terms in the decomposition for the case of Rayleigh fading are also derived     

46,XX/69,XXX diploid-triploid mixoploidy with hypothyroidism and precocious puberty

We report a 20 month old female patient with diploid-triploid mixoploidy (46,XX/69,XXX) syndrome with hypothyroidism and precocious puberty. The triploid cell line was only expressed in the fibroblast culture and comprised the majority (95%) of the cells. Chromosome analysis of the fetal blood sample and peripheral blood sample were normal. The patient shows typical features of full triploidy (growth and severe mental retardation, cranial and facial dysmorphism, complete syndactyly of fingers 3/4, partial syndactyly of toes 2/3) and facial but no body asymmetry. At the age of 5 months central hypothyroidism and precocious puberty were diagnosed. Thin pigmented streaks were visible on the wrists and legs of the patient at the age of 16 months. This is the first patient reported so far with 46,XX/69,XXX mixoploidy suffering from hypothyroidism and precocious puberty.     

Heart transplantation in Finland 1985-1995

BACKGROUND: Clearance of large molecules from the interstitial space is an important function of lymphatics and is affected by local pathologic changes. OBJECTIVE: To determine if the clearance rate of interstitially injected albumin is correlated to tumour characteristics and outcome in women with invasive breast cancer. METHOD: In a consecutive series of women coming to biopsy for suspected breast cancer, technetium-tagged albumin was injected into the tissue adjacent to the palpable mass. The isotope disappearance rate was measured over two hours. Also assessed were the maximum vessel density (MVD-using Factor VIII polyclonal antisera), the proliferation rate (using Ki-67 antisera), node status, tumour size, histologic and nuclear grade, mitotic rate, and p53 and c-erbB-2 oncoproteins. All patients were followed until relapse and for a minimum of 10 years. RESULTS: In multivariate analysis, an association between relapse-free survival and isotope clearance rate was suggested (p = 0.024). The best outcome was seen in patients with the least isotope clearance. Node status, size, histologic and nuclear grade, and mitotic rate correlated with survival. MVD did not correlate with survival and was inversely related to the isotope clearance rate. Tumour proliferation rate, and the c-erbB-2 and p53 oncoproteins did not relate to outcome. CONCLUSION: The role of lymphatics in breast cancer is difficult to study. Measurement of interstitial clearance may be a useful technique and could be a prognostic factor.     

Macrophage activation results in bone resorption

Monocytes or macrophages from important accessory cells in the regulation of bone metabolism and destruction. Cells of the mononuclear phagocyte lineage form the precursor cells of the osteoclasts. Soluble products produced by activated macrophages regulate progenitor cell proliferation, recruitment, differentiation, and activity of osteoblasts and osteoclasts. After osteoclasts are removed from the resorption site, macrophages process bone surfaces and create a cement line before osteoblasts enter to form new bone. Although osteolysis associated with normal bone remodeling is seen as an osteoclast driven process, it may be that in chronic inflammation macrophage activation and vascular derangements lead to low pH, local bone demineralization (acid attack), and H+ mediated stimulation of the primary afferent nociceptive nerve fibers (bone pain). Osteoclasts are not able to attach to demineralized bone or to osteoid surfaces. However, if macrophages degrade the demineralized organic bone matrix, chemotactic factors and attachment sites for osteoclasts are produced. In such a scenario, the osteoclast-osteoblast mediated activation, resorption, and formation cycle would be secondarily activated. Such events may play a role in the most common orthopaedic problem related to macrophage activation, aseptic loosening of orthopaedic joint implants, which is secondary to a chronic foreign body reaction and to micromovement.     

Atlantoaxial instability complicating radiation therapy for recurrent nasopharyngeal carcinoma. A case report

STUDY DESIGN: A case report of a patient in whom atlantoaxial instability developed secondary to repeat radiation therapy for recurrent nasopharyngeal carcinoma. OBJECTIVES: To illustrate a dramatic and previously unreported complication of local radiation to the posterior nasopharynx. SUMMARY OF BACKGROUND DATA: Nasopharyngeal carcinoma is an unusual tumor that usually is managed with local, external-beam radiation. It is not thought to involve the cervical spine directly, although local invasion of the skull base is common. METHODS: A review of the medical records and radiographs of the only patient known to develop this complication of radiation used to manage nasopharyngeal carcinoma. RESULTS: Atlantoaxial instability developed in a patient as a result of repeat radiation for a locally recurrent tumor. The instability was associated with intrusion of the anterior arch of C1 into the posterior nasopharynx and was managed successfully with a posterior stabilization using transarticular screws and supplemental wiring. CONCLUSIONS: Patients who have undergone local irradiation for nasopharyngeal carcinoma may be at risk for developing atlantoaxial instability.     

Expression and Roles of Individual HIF Prolyl 4-Hydroxylase Isoenzymes in the Regulation of the Hypoxia Response Pathway along the Murine Gastrointestinal Epithelium

The HIF prolyl 4-hydroxylases (HIF-P4H) control hypoxia-inducible factor (HIF), a powerful mechanism regulating cellular adaptation to decreased oxygenation. The gastrointestinal epithelium subsists in “physiological hypoxia” and should therefore have an especially well-designed control over this adaptation. Thus, we assessed the absolute mRNA expression levels of the HIF pathway components, Hif1a, HIF2a, Hif-p4h-1, 2 and 3 and factor inhibiting HIF (Fih1) in murine jejunum, caecum and colon epithelium using droplet digital PCR. We found a higher expression of all these genes towards the distal end of the gastrointestinal tract. We detected mRNA for Hif-p4h-1, 2 and 3 in all parts of the gastrointestinal tract. Hif-p4h-2 had significantly higher expression levels compared to Hif-p4h-1 and 3 in colon and caecum epithelium. To test the roles each HIF-P4H isoform plays in the gut epithelium, we measured the gene expression of classical HIF target genes in Hif-p4h-1^−/−, Hif-p4h-2 hypomorph and Hif-p4h-3^−/− mice. Only Hif-p4h-2 hypomorphism led to an upregulation of HIF target genes, confirming a predominant role of HIF-P4H-2. However, the abundance of Hif-p4h-1 and 3 expression in the gastrointestinal epithelium implies that these isoforms may have specific functions as well. Thus, the development of selective inhibitors might be useful for diverging therapeutic needs.     

Processing intrusion detection alert aggregates with time series modeling

The main use of intrusion detection systems (IDS) is to detect attacks against information systems and networks. Normal use of the network and its functioning can also be monitored with an IDS. It can be used to control, for example, the use of management and signaling protocols, or the network traffic related to some less critical aspects of system policies. These complementary usages can generate large numbers of alerts, but still, in operational environment, the collection of such data may be mandated by the security policy. Processing this type of alerts presents a different problem than correlating alerts directly related to attacks or filtering incorrectly issued alerts.We aggregate individual alerts to alert flows, and then process the flows instead of individual alerts for two reasons. First, this is necessary to cope with the large quantity of alerts – a common problem among all alert correlation approaches. Second, individual alert’s relevancy is often indeterminable, but irrelevant alerts and interesting phenomena can be identified at the flow level. This is the particularity of the alerts created by the complementary uses of IDSes.Flows consisting of alerts related to normal system behavior can contain strong regularities. We propose to model these regularities using non-stationary autoregressive models. Once modeled, the regularities can be filtered out to relieve the security operator from manual analysis of true, but low impact alerts. We present experimental results using these models to process voluminous alert flows from an operational network.     

Engineered Multifunctional Albumin‐Decorated Porous Silicon Nanoparticles for FcRn Translocation of Insulin

The last decade has seen remarkable advances in the development of drug delivery systems as alternative to parenteral injection‐based delivery of insulin. Neonatal Fc receptor (FcRn)‐mediated transcytosis has been recently proposed as a strategy to increase the transport of drugs across the intestinal epithelium. FcRn‐targeted nanoparticles (NPs) could hijack the FcRn transcytotic pathway and cross the epithelial cell layer. In this study, a novel nanoparticulate system for insulin delivery based on porous silicon NPs is proposed. After surface conjugation with albumin and loading with insulin, the NPs are encapsulated into a pH‐responsive polymeric particle by nanoprecipitation. The developed NP formulation shows controlled size and homogeneous size distribution. Transmission electron microscopy (TEM) images show successful encapsulation of the NPs into pH‐sensitive polymeric particles. No insulin release is detected at acidic conditions, but a controlled release profile is observed at intestinal pH. Toxicity studies show high compatibility of the NPs with intestinal cells. In vitro insulin permeation across the intestinal epithelium shows approximately fivefold increase when insulin is loaded into FcRn‐targeted NPs. Overall, these FcRn‐targeted NPs offer a toolbox in the development of targeted therapies for oral delivery of insulin.     

Results of Finnish national survey on EU legislation concerning computer work

The European Directive on computer work (VDU 90/270/EEC) is implemented in the Finnish Government Decree. The aim of the present study was to evaluate the effects of the legislation and its applications in practice. The quantitative method used an online questionnaire. The respondents were employers (N = 934), employees (N = 1872) and occupational health care (OHC) units (N = 289). The majority of all these three groups considered the provisions clear and easy to understand, comprehensive, and easy to comply with. The provisions had a great impact on preventing mental overloading, arranging sight tests at the employer's cost, and on the refunding of eyeglasses for computer work. Most employers felt they did not need any more specific provisions, whereas half of the employees and OHC professionals would have liked the provisions to be more detailed. More explicit and specific regulations were also needed for practice applications in particular, as well as for the refunding of the costs of special eyeglasses for computer work. A total of 59% of the employers reported that costs of glasses are refunded, whereas the figure for employees was clearly lower (37%). OHC professionals reported that the costs of glasses were refunded in 82% of their customer workplaces. The practical conclusion is that employees' sight examinations and compensation for eyeglasses should be promoted in computer work. Moreover, ergonomic applications are best carried out in co-operation with OHC personnel.