The Coriolis Interaction between the v2 = 1 and v3 = 2 States of Nitrosyl Bromide: Anomalous Quadrupole Patterns and Interstate Transitions in the Millimeter-Wave Spectrum

The millimeter-wave rotational spectra of 79BrNO and 81BrNO in the v2 = 1 and v3 = 2 vibrational states have been reinvestigated. Measurements of the rotational spectrum in the region of maximum c-type Coriolis interaction between the two states allowed the previous analysis to be extended to account for some uncommon effects. For the most perturbed transitions the nuclear quadrupole hyperfine structure arises from coupling of not only the bromine nucleus, but also the nitrogen nucleus with the rotational angular momentum. These effects were satisfactorily fitted with a Hamiltonian describing Coriolis coupling in a molecule with two quadrupolar nuclei. The successful analysis of pure rotational transitions then allowed accurate prediction of rovibrational transitions, six of which were measured for 79BrNO and four for 81BrNO. Copyright 1998 Academic Press.     

Developmental aspects of dendritic cells in vitro and in vivo

Our knowledge in immunology has been dramatically increased by several excellent investigations elucidating the role of the Fas (Apo-1/CD95) receptor/ligand (FasL) system in complex immunological processes such as the acquisition of self tolerance in T cells, progression of autoimmunity, clonal deletion of activated T cells, B-cell regulation and the establishment of "immune privileged" sites such as testis or retina. In addition to these regulatory immunological activities, Fas/FasL interaction was also shown to participate in active defense mechanisms of the host against infected or transformed cells thereby inducing apoptosis in target cells. However, the same mechanism seems also to be part of an escape strategy utilized by tumor cells in various neoplastic malignancies of both hematopoetic as also non-hematopoetic origin. We ourselves were able to demonstrate that neoplastic plasma cell lines, as well as native malignant myeloma cells constitutively express FasL mRNA and protein. The FasL molecule is functionally active and able to induce programmed cell death in Fas sensitive target T cells in vitro. These target T cells were protected from programmed cell death by preincubation of T cells with a Fas-blocking monoclonal antibody (mAb) or of myeloma cells with a FasL-neutralizing mAb. respectively. Furthermore, overexpression of the caspase inhibitor, cowpoxvirus protein CrmA, also protected target T cells from being killed by myeloma cells, identifying Fas/FasL mediated signaling as the effector pathway utilized by malignant plasma cells. Our observations strongly suggest the engagement of Fas/FasL interaction in the escape strategy of this malignancy. The molecular basis of this evasive mechanism differs in essential respects from those described in melanoma, lung cancer, hepatocellular carcinoma, or astrocytoma, since downregulation of Fas or instrinsic insensitivity towards Fas-mediated signaling were not prerequisites for the occurrence of this phenomenon in Fas-sensitive multiple myeloma cell lines. However, myeloma cell lines resisted cocultivation with FasL-expressing target T cells in vitro. The aim of this review is to discuss the role of Fas/FasL interaction in the establishment of malignant disease, in the light of our findings on myeloma cells and also by drawing upon similar observations of other investigators on different kinds of tumor cells and cell lines and further to consider its possible relevance in formulating novel approaches to cancer therapy.     

Do cardiovascular risk factors explain the relation between socioeconomic status, risk of all-cause mortality, cardiovascular mortality, and acute myocardial infarction?

Much remains to be understood about how low socioeconomic status (SES) increases cardiovascular disease and mortality risk. Data from the Kuopio Ischemic Heart Disease Risk Factor Study (1984-1993) were used to estimate the associations between acute myocardial infarction and income, all-cause mortality, and cardiovascular mortality in a population-based sample of 2,272 Finnish men, with adjustment for 23 biologic, behavioral, psychologic, and social risk factors. Compared with the highest income quintile, those in the bottom quintile had age-adjusted relative hazards of 3.14 (95% confidence interval (CI) 1.77-5.56), 2.66 (95% CI 1.25-5.66), and 4.34 (95% CI 1.95-9.66) for all-cause mortality, cardiovascular mortality, and AMI, respectively. After adjustment for risk factors, the relative hazards for the same comparisons were 1.32 (95% CI 0.70-2.49), 0.70 (95% CI 0.29-1.69), and 2.83 (95% CI 1.14-7.00). In the lowest income quintile, adjustment for risk factors reduced the excess relative risk of all-cause mortality by 85%, that of cardiovascular mortality by 118%, and that of acute myocardial infarction by 45%. These data show how the association between SES and cardiovascular mortality and all-cause mortality is mediated by known risk factor pathways, but full "explanations" for these associations will need to encompass why these biologic, behavioral, psychologic, and social risk factors are differentially distributed by SES.     

Ischemic proctosigmoiditis

Rectal ischemia is rare because of excellent collateral supply. Although rectosigmoid ischemia is usually accompanied by more proximal colonic involvement, it may occur alone. METHODS: A retrospective review of all patients diagnosed as having colonic ischemia at the Mayo Clinic from 1976 to 1991 was performed. Clinical, endoscopic, radiological, and pathological data were obtained from patient charts. Patients with involvement of the rectosigmoid colon extending to no more than 30 cm above the dentate line on endoscopy were included in the study. A single radiologist reviewed CT scans and aortograms, and a single pathologist reviewed tissue specimens. RESULTS: Ten of 328 patients with ischemic colitis had isolated ischemic proctosigmoiditis. Six patients had acute ischemia (i.e., symptom duration of less than 4 wk), and four had chronic ischemia (symptoms for 4 wk or longer). Ischemic proctosigmoiditis affects elderly patients with atherosclerosis. An identifiable precipitating factor, such as a major illness or hemodynamic disturbance, was identified in four of six patients with acute ischemic proctosigmoiditis and in one of four patients with chronic ischemic proctosigmoiditis. CT revealed rectal wall thickening and/or perirectal stranding. Angiography may demonstrate atheromatous disease of the aortoiliac vessels. Acute and "chronic" presentations had similar histopathological changes. CONCLUSIONS: Ischemic proctosigmoiditis is rare. In contrast to generalized colonic ischemia, patients with acute rectal ischemia often have clearly identifiable precipitating factors. Conservative management is appropriate for uncomplicated acute ischemic proctosigmoiditis. Patients with chronic ischemic proctosigmoiditis. Patients with chronic ischemic proctosigmoiditis may develop bowel perforation necessitating a proctectomy or colonic diversion. Recognition of this entity and differentiation from idiopathic inflammatory bowel disease is important to determine appropriate therapy.     

Rambo: a robust, reconfigurable atomic memory service for dynamic networks

In this paper, we present Rambo, an algorithm for emulating a read/write distributed shared memory in a dynamic, rapidly changing environment. Rambo provides a highly reliable, highly available service, even as participants join, leave, and fail. In fact, the entire set of participants may change during an execution, as the initial devices depart and are replaced by a new set of devices. Even so, Rambo ensures that data stored in the distributed shared memory remains available and consistent. There are two basic techniques used by Rambo to tolerate dynamic changes. Over short intervals of time, replication suffices to provide fault-tolerance. While some devices may fail and leave, the data remains available at other replicas. Over longer intervals of time, Rambo copes with changing participants via reconfiguration, which incorporates newly joined devices while excluding devices that have departed or failed. The main novelty of Rambo lies in the combination of an efficient reconfiguration mechanism with a quorum-based replication strategy for read/write shared memory. The Rambo algorithm can tolerate a wide variety of aberrant behavior, including lost and delayed messages, participants with unsynchronized clocks, and, more generally, arbitrary asynchrony. Despite such behavior, Rambo guarantees that its data is stored consistency. We analyze the performance of Rambo during periods when the system is relatively well-behaved: messages are delivered in a timely fashion, reconfiguration is not too frequent, etc. We show that in these circumstances, read and write operations are efficient, completing in at most eight message delays.     

Nonlinear observers with approximately linear error dynamics: themultivariable case

Exact error linearization uses nonlinear input-output injection to design observers with linear error dynamics in certain coordinates. This approach can only be applied nongenerically. We propose an observer for a wider class of multivariable systems which uniformly minimizes the nonlinear part of the system that cannot be canceled by nonlinear input-output injection. Our approach is numerical, constructive, and provides locally exponentially stable error dynamics. An example compares our design with a high-gain method     

The BG distributed simulation algorithm

We present a shared memory algorithm that allows a set of f+1 processes to wait-free “simulate” a larger system of n processes, that may also exhibit up to f stopping failures. Applying this simulation algorithm to the k-set-agreement problem enables conversion of an arbitrary k-fault-tolerant{\it n}-process solution for the k-set-agreement problem into a wait-free k+1-process solution for the same problem. Since the k+1-processk-set-agreement problem has been shown to have no wait-free solution [5,18,26], this transformation implies that there is no k-fault-tolerant solution to the n-process k-set-agreement problem, for any n. More generally, the algorithm satisfies the requirements of a fault-tolerant distributed simulation.\/ The distributed simulation implements a notion of fault-tolerant reducibility\/ between decision problems. This paper defines these notions and gives examples of their application to fundamental distributed computing problems. The algorithm is presented and verified in terms of I/O automata. The presentation has a great deal of interesting modularity, expressed by I/O automaton composition and both forward and backward simulation relations. Composition is used to include a safe agreement\/ module as a subroutine. Forward and backward simulation relations are used to view the algorithm as implementing a multi-try snapshot\/ strategy. The main algorithm works in snapshot shared memory systems; a simple modification of the algorithm that works in read/write shared memory systems is also presented. Received: February 2001 / Accepted: February 2001     

A criticism of the Flood-Grjotheim ionic treatment of slag-equilibria

The analysis by Flood and Grjotheim¹ of the equilibria between a metal and a fused slag utilizes the ionic behavior of the slag or salt, and it employs a reversible thermodynamic cycle. However, in the original analysis there appears to be an error in the use of free energy. A corrected treatment has been developed which involves a modest change and simplification in the original formulation. The revised analysis shows the importance of the thermodynamic behavior of ionic species in the slag, which may be nonideal. Data from the literature on slag-metal equilibria, for example: $$\left[ {Fe^{2 + } } \right] + \underline {Mn} = Fe\left( l \right) + \left[ {Mn^{2 + } } \right]$$ , are analyzed by the new formulation to obtain expressions for ratios of activity coefficients such as (γS^2?/γO^2?), (γMn²⁺/γFe²⁺) and [(γPO ₄ ^3? )²/(γO^2?)³] in terms of slag composition, the last two having been found to depend strongly on the oxygen-ion content of the slag.     

Determination of glucose with glucoseoxidase-UV, using hexokinase as the reference method (author's transl)

Results obtained with the commercial test-set "GOD-UV" (Dr. Haury, München) are reported. This method permits the determination of serum-glucose within 3 minutes. The procedure is satisfactory in normal and hyperglycaemic patients. In the hypoglycaemic state, however, there is a danger of misinterpretation. The glucose oxidase-UV is compared with the hexokinase reaction.