A Semantic Future for AI

Computing must become much more human centered--for example, by presenting personalized information to users and by respecting personal preferences when controlling multiple devices or invoking various services. Appropriate representation of the information's semantics and of the functionality of devices and services will be critical to such personalized computing. Symbolic artificial intelligence techniques provide the method of choice for the required semantic-representation and reasoning capabilities.     

Morphological and functional polymorphism within clonal thyroid nodules

Thirty-nine thyroid nodules, removed because of recent growth, were analyzed morphologically by serial histological sections for the classical histomorphological hallmarks of follicular cell replication and for immunohistochemically demonstrable overexpression of the growth-associated ras-gene product p21ras. Clonal analysis was performed using the highly informative probe M27 beta that detects polymorphisms on the locus DXS255 of the X-chromosome. Twenty-four nodules were of clonal and 15 nodules were of poly-clonal origin. Only 3 out of the 24 clonal nodules were histomorphologically uniform. In all others, the structural hallmarks of active growth and the P21ras growth-marker expression were remarkably heterogeneous throughout the tumors. There were no histomorphological characteristics distinguishing these clonal tumors from polyclonal nodules. Even if a clonal thyroid tumor may be originally homogeneous in respect to the parameters studied here, mechanisms must exist that create wide heterogeneity of growth and of morphogenetic potential among the individual follicular cells during further expansion of the nodule. Thus, clonal nodules are much more common in nodular goiters than hitherto assumed on grounds of the classical morphological criteria. The diagnosis of a true monoclonal nodule can no longer rely on morphological and functional criteria alone but requires molecular or cytogenetic analysis of clonality.     

Urological emergencies

Every general practitioner has to deal with urologic emergencies. The most frequent illnesses are urinary retention, acute scrotum, priapism, macrohematuria, nephritic colic, obstructive pyelonephritis and pyonephrosis. Whereas urinary retention, as well as acute ureteric stone colic must generally be treated by the practitioner, the urologist must often be consulted in case of an acute scrotum or for priapism. Testicular torsion is one situation, where surgical treatment needs to be performed within 6 hours. Of utmost importance is his timely assistance with the obstructive pyelonephritis and pyonephrosis. These are initially often not recognized, especially because the first ultrasound examination of the intrarenal pyelone may not show a dilatation of the collecting system despite obstruction. If the adequate treatment with drainage and antibiotics is applied too late, this can result in serious and potentially lethal consequences.     

A quality culture for health promotion!

Circulating platelets are susceptible to various stimuli in vessels, and a certain portion of platelets may thereby form native microaggregates (NMAs), which can be visualized by a bother scanning electron microscopy (SEM). We developed an easy method to evaluate the existence and extent of NMAs and the subsequent spontaneous platelet aggregation (SPA) induced by not any agonist but stirring force with a novel platelet aggregometer (PA-200; Kowa, Tsukuba, Japan) employing a particle-counting method based on laser light scattering. In this system, platelet-rich plasma obtained by a delicate centrifugation was infused in a cuvette to replace the content and to avoid stirring shear. An insertion attachment was designed in a coaxial shape to maintain a constant sample volume. Our data indicated that NMAs, tentatively defined as a "small" division by their light scattering (25-400 of the intensity threshold), could be detected by not only a complicated SEM but also by our simple system with the PA-200 in a few minutes. No correlation was found in the comparison of the existence of NMAs and the SPA generation, in aliquot platelets, respectively. These results suggested that NMAs and SPA might be mutually different cluster and have meanings as representations of platelet status.     

Common knowledge does not have the Beth property

Common knowledge is an essential notion for coordination among agents. We show that the logic of common knowledge does not have the Beth property and thus it also lacks interpolation. The proof we present is a variant of Maksimova's proof that temporal logics with ‘the next’ do not have the Beth property. Our result also provides an explanation why it is so difficult to find ‘nice’ deductive systems for common knowledge.     

Measuring Single-Crystal Diffuse Neutron Scattering on the Wombat High-Intensity Powder Diffractometer

Single-crystal diffuse scattering was collected on the Wombat high-intensity powder diffractometer at the OPAL reactor at the Bragg Institute. The difficulty in measuring diffuse scattering comes from its relatively low intensity compared to the Bragg peaks, a factor of 10³10^{3} to 10⁴10^{4} smaller. Wombat allows collection of diffuse scattering due to its high intensity and large two-dimensional detector. Diffuse scattering data from yttria-stabilized cubic zirconia (YCSZ, Y₂O₃\hbox{Y}_2\hbox{O}_3 stabilized ZrO₂\hbox{ZrO}_2) and PbZn_1/3Nb_2/3O₃\hbox{PbZn}_{1/3}\hbox{Nb}_{2/3}\hbox{O}_3 (PZN) were successfully collected, the latter at a range of temperatures. The data were processed, normalized, and background subtracted to reconstruct flat reciprocal space sections with a minimum of artifacts. The strategies used to tackle the collection of neutron diffuse scattering and the way in which they are implemented will be discussed. The results show that the neutron powder diffractometer with a continuous detector is capable of collecting high-quality diffuse scattering data.