Detecting Life and Biology-Related Parameters on Mars

An integrated, miniaturized, low-power instrument capable of the detection and early characterization of microbial life in the soil of Mars is proposed. Based on the detection apd monitoring of on-going metabolism as being the surest evidence for extant life, the experiments will probe for chirality in metabolism, for circadian rhythm, and for photosynthesis. However, the instrument package will also be able to detect biosignatures and a variety of other physical and chemical parameters of the Martian surface that have significance for life. These include the presence and the physical state of water, the existence of an oxidant, the pH and the penetrability of the soil. Using the legacy of the 1976 Viking Labeled Release (LR) life detection experiment in conjunction with state-of-the-art laser diode spectral analysis, the instrument can be flown stand-alone, with or without a rover, or as part of an MSL-type mission. Sterility for experiment integrity and for planetary protection is provided

Dose escalation study of an anti-thrombocytopenic agent in patients with chemotherapy induced thrombocytopenia

<p>Abstract</p> <p>Background</p> <p>Preclinical studies demonstrated that small chain RNA fragments accelerate the recovery of platelets numbers in animals exposed to high doses of chemotherapeutic drugs. There is anecdotal data supporting the same application in humans. The Phase I clinical trial described here was designed to investigate the relationship between the administration of small chain RNA fragments and the recovery in platelets following Chemotherapy-Induced Thrombocytopenia (CIT).</p> <p>Methods</p> <p>Cancer patients with solid tumors that experienced post chemotherapy thrombocytopenia with a nadir of < = 80,000 platelets/ml were eligible for this clinical trial. There were no exclusions based on ECOG status, tumor type, tumor burden or chemotherapeutic agents. Patients received a unique preparation of RNA derived from either E. coli or yeast. Ten patients per group received 20, 40, or 60 mg as a starting dose. Subjects self-administered RNA fragments sublingually on an every other day schedule while undergoing chemotherapy. The dose was escalated in 20 mg increments to a maximum dose of 80 mg if the nadir was < 80,000 platelets/ml at the start of the next cycle. Subjects were treated for three cycles of chemotherapy with the maximum effective dose of RNA fragments. Subjects continued on planned chemotherapy as indicated by tumor burden without RNA fragment support after the third cycle. Subjects kept a diary indicating RNA fragment and magnesium administration, and any experienced side effects.</p> <p>Results</p> <p>Patients receiving E. coli RNA fragments demonstrated a more rapid recovery in platelet count and higher nadir platelet count. None of the patients receiving the E. coli RNA fragments required a chemotherapy dose reduction due to thrombocytopenia. The optimal dose for minimizing CIT was 80 mg. Conversely, subjects receiving yeast RNA fragments with dose escalation to 80 mg required a chemotherapy dose reduction per American Society of Clinical Oncology guidelines for grade 3 and 4 thrombocytopenia.</p> <p>Conclusions</p> <p>Patients receiving myelosuppressive chemotherapy experienced an improvement in the platelet nadir and shorter recovery time when receiving concurrent E coli RNA fragments, when compared to patients who received yeast RNA fragments. These data indicate that 60 and 80 mg doses of E. coli RNA accelerated platelet recovery. Further clinical investigations are planned to quantify the clinical benefits of the E. coli RNA at the 80 mg dose in patients with chemotherapy induced thrombocytopenia.</p> <p>Trial Registration</p> <p>Clinical Trials.gov Identifier: NCT01163110</p

Do (and say) as I say: Linguistic adaptation in human-computer dialogs

© Theodora Koulouri, Stanislao Lauria, and Robert D. Macredie. This article has been made available through the Brunel Open Access Publishing Fund.There is strong research evidence showing that people naturally align to each other’s vocabulary, sentence structure, and acoustic features in dialog, yet little is known about how the alignment mechanism operates in the interaction between users and computer systems let alone how it may be exploited to improve the efficiency of the interaction. This article provides an account of lexical alignment in human–computer dialogs, based on empirical data collected in a simulated human–computer interaction scenario. The results indicate that alignment is present, resulting in the gradual reduction and stabilization of the vocabulary-in-use, and that it is also reciprocal. Further, the results suggest that when system and user errors occur, the development of alignment is temporarily disrupted and users tend to introduce novel words to the dialog. The results also indicate that alignment in human–computer interaction may have a strong strategic component and is used as a resource to compensate for less optimal (visually impoverished) interaction conditions. Moreover, lower alignment is associated with less successful interaction, as measured by user perceptions. The article distills the results of the study into design recommendations for human–computer dialog systems and uses them to outline a model of dialog management that supports and exploits alignment through mechanisms for in-use adaptation of the system’s grammar and lexicon

Herpes Zoster and Cardiovascular Events in Adults: A Systematic Review

Background: Stroke and myocardial infarction have been reported to occur after the development of herpes zoster (shingles), a common and preventable disease. Purpose: To evaluate literature describing the association between herpes zoster and its subtypes with the occurrence of cardiovascular events. Data Sources: PubMed, SCOPUS (Embase), OAIster, Google Scholar (searched in January 2016) Study Selection: Studies published up to January 2016 examining the association between herpes zoster or subtype of herpes zoster with the occurrence of cardiovascular events, including stroke, transient ischemic attack, or an acute coronary event, were selected. Case reports, case studies, and studies of non-general adult populations were excluded. Data Extraction: Data from studies meeting criteria were abstracted on a standardized form, and evaluated following modified set of standard guidelines. Data Synthesis: Nine published articles, with study populations ranging from 2,632 to 4,620,980 patients, met our pre-defined eligibility criteria. Eight studies found at least one positive association between herpes zoster type unspecified and subsequent stroke, transient ischemic attack, or an acute coronary event. Five studies found positive associations between herpes zoster ophthalmicus and stroke or myocardial infarction. Subgroup analyses from three studies were inconsistent regarding the association of cardiovascular events with receipt of antiviral therapy for herpes zoster. Limitations: Excludes non-English publications and non-published evidence. Conclusions: A small number of studies showed greater risks of stroke, transient ischemic attack, and acute cardiac events following the development of herpes zoster and herpes zoster ophthalmicus. Further prospective studies should develop strategies to reduce the risk of cardiovascular disease among patients with herpes zoster

A systematic review and meta-analysis on herpes zoster and the risk of cardiac and cerebrovascular events

BACKGROUND: Patients who develop herpes zoster or herpes zoster ophthalmicus may be at risk for cerebrovascular and cardiac complications. We systematically reviewed the published literature to determine the association between herpes zoster and its subtypes with the occurrence of cerebrovascular and cardiac events. METHODS/RESULTS: Systematic searches of PubMed (MEDLINE), SCOPUS (Embase) and Google Scholar were performed in December 2016. Eligible studies were cohort, case-control, and self-controlled case-series examining the association between herpes zoster or subtypes of herpes zoster with the occurrence of cerebrovascular and cardiac events including stroke, transient ischemic attack, coronary heart disease, and myocardial infarction. Data on the occurrence of the examined events were abstracted. Odds ratios and their accompanying confidence intervals were estimated using random and fixed effects models with statistical heterogeneity estimated with the I2 statistic. Twelve studies examining 7.9 million patients up to 28 years after the onset of herpes zoster met our pre-defined eligibility criteria. Random and fixed effects meta-analyses showed that herpes zoster, type unspecified, and herpes zoster ophthalmicus were associated with a significantly increased risk of cerebrovascular events, without any evidence of statistical heterogeneity. Our meta-analysis also found a significantly increased risk of cardiac events associated with herpes zoster, type unspecified. CONCLUSIONS: Our results are consistent with the accumulating body of evidence that herpes zoster and herpes zoster ophthalmicus are significantly associated with cerebrovascular and cardiovascular events

Kinetic Characterization of Catalysis by the Chemotaxis Phosphatase CheZ: MODULATION OF ACTIVITY BY THE PHOSPHORYLATED CheY SUBSTRATE

CheZ catalyzes the dephosphorylation of the response regulator CheY in the two-component regulatory system that mediates chemotaxis in Escherichia coli. CheZ is a homodimer with two active sites for dephosphorylation. To gain insight into cellular mechanisms for the precise regulation of intracellular phosphorylated CheY (CheYp) levels, we evaluated the kinetic properties of CheZ. The steady state rate of CheZ-mediated dephosphorylation of CheYp displayed marked sigmoidicity with respect to CheYp concentration and a k(cat) of 4.9 s(-1). In contrast, the gain of function mutant CheZ-I21T with an amino acid substitution far from the active site gave hyperbolic kinetics and required far lower CheYp for half-saturation but had a similar k(cat) value as the wild type enzyme. Stopped flow fluorescence measurements demonstrated a 6-fold faster CheZ/CheYp association rate for CheZ-I21T (k(assoc) = 3.4 x 10(7) M (-1) s(-1)) relative to wild type CheZ (k(assoc) = 5.6 x 10(6) M(-1) s(-1)). Dissociation of the CheZ.CheYBeF(3) complex was slow for both wild type CheZ (k(dissoc) = 0.040 s(-1)) and CheZ-I21T (k(dissoc) = 0.023 s(-1)) and, when taken with the k(assoc) values, implied K(d) values of 7.1 and 0.68 nm, respectively. However, comparison of the k(dissoc) and k(cat) values implied that CheZ and CheYp are not at binding equilibrium during catalysis and that once CheYp binds, it is almost always dephosphorylated. The rate constants were collated to formulate a kinetic model for CheZ-mediated dephosphorylation that includes autoregulation by CheYp and allowed prediction of CheZ activities at CheZ and CheYp concentrations likely to be present in cells