Cognitive Information Processing

Contains reports on one research project.National Institutes of Health (Grant 5 P01 GM14940-07

Retrospective Analysis of Post-Operative Sepsis Rates, Stone Composition, and Ureteral Stent Duration after Ureteroscopy and Laser Lithotripsy During COVID-19

Ureteroscopy with laser lithotripsy is routinely used to remove stones but results in manipulation of the genitourinary mucosa and has a well-established relationship with post-operative sepsis under certain conditions. Postoperative sepsis represents a significant morbidity and mortality cost to patients and the healthcare system. Several studies to determine risk factors for sepsis after ureteroscopy have been completed. Such risk factors include positive preoperative urine cultures, female gender, prolonged preoperative stent time \u3e 1 month, and patients with sepsis at the time of initial stenting. To improve sepsis rates, procedural alterations such as the use of disposable ureteroscopes have been introduced, as there is some evidence that there may be residual bacteria on reusable ureteroscopes after sterilization. It is unclear how much this contributes to postoperative sepsis, as it may be an inflammatory response rather than true bacteremia. Stone type may also be associated with bacteriuria as certain stones, such as struvite (magnesium ammonium phosphate) stones, form only in the presence of urease-producing bacteria such as Proteus, E. coli, and Enterococcus. However, this has been challenged with recent percutaneous nephrolithotomy studies suggesting that struvite stones are created during infections but could potentially be sterilized, while carbonate apatite stones retain imprints of bacteria. This investigation reviews if there were significant differences over the last three years in mean ureteral stent time, stone composition, or post-operative sepsis rates in patients who underwent ureteroscopy with laser lithotripsy, as well as if the COVID-19 pandemic had any significant impact on this data. Data has been shown that urological procedures has taken drastic decrease in number due to COVID-19 as elective cases were cancelled

Using Narrow Band Photometry to Classify Stars and Brown Dwarfs

We present a new system of narrow band filters in the near infrared that can be used to classify stars and brown dwarfs. This set of four filters, spanning the H band, can be used to identify molecular features unique to brown dwarfs, such as H2O and CH4. The four filters are centered at 1.495 um (H2O), 1.595 um (continuum), 1.66 um (CH4), and 1.75 um (H2O). Using two H2O filters allows us to solve for individual objects' reddenings. This can be accomplished by constructing a color-color-color cube and rotating it until the reddening vector disappears. We created a model of predicted color-color-color values for different spectral types by integrating filter bandpass data with spectra of known stars and brown dwarfs. We validated this model by making photometric measurements of seven known L and T dwarfs, ranging from L1 - T7.5. The photometric measurements agree with the model to within +/-0.1 mag, allowing us to create spectral indices for different spectral types. We can classify A through early M stars to within +/-2 spectral types, late-type M and L dwarfs to within +/-0.3 spectral types and T dwarfs to within +/-0.1 spectral types 1-sigma. Thus, we can distinguish between a T1 and a T3 dwarf. The four physical bands can be converted into two reddening-free indices, mu1 and mu2, and an extinction, AV, for the individual object. This technique, which is equivalent to extremely low resolution spectroscopy, can be used to survey large areas to provide rough spectral classifications for all the stars in the area, ranging down to the coolest brown dwarfs. It should prove particularly useful in young clusters where reddening can be high.Comment: 20 pages, 8 figures, submitted 18 Aug. 2003, accepted 5 Dec. 2003 to Ap

Novel mRNA-specific effects of ribosome drop-off on translation rate and polysome profile

IS and MCR were supported by the Biotechnology and Biological Sciences Research Council (BBSRC) (http://www.bbsrc.ac.uk) BB/N017161/1. IS was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) (http://www.bbsrc.ac.uk) BB/I020926/1. PB and MCR were supported by the Scottish Universities Life Sciences Alliance (SULSA) (http://www.sulsa.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons

A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting’s theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond

What can we learn from trial decliners about improving recruitment? Qualitative study

Background Trials increasingly experience problems in recruiting participants. Understanding the causes of poor recruitment is critical to developing solutions. We interviewed people who had declined a trial of an innovative psychological therapy for depression (REFRAMED) about their response to the trial invitation, in order to understand their decision and identify ways to improve recruitment. Methods Of 214 people who declined the trial, 35 (16 %) gave permission to be contacted about a qualitative study to explore their decision. Analysis of transcripts of semi-structured interviews was informed by grounded theory. Results We interviewed 20 informants: 14 women and six men, aged 18 to 77 years. Many interviewees had prior experience of research participation and positive views of the trial. Interviewees’ decision making resembled a four-stage sequential process; in each stage they either decided not to participate in the trial or progressed to the next stage. In stage 1, interviewees assessed the invitation in the context of their experiences and attitudes; we term those who opted out at this stage ‘prior decliners’ as they had an established position of declining trials. In stage 2, interviewees assessed their own eligibility; those who judged themselves ineligible and opted out at this stage are termed ‘self-excluders’. In stage 3, interviewees assessed their need for the trial therapy and potential to benefit; we term those who decided they did not need the trial therapy and opted out at this stage ‘treatment decliners’. In stage 4, interviewees deliberated the benefits and costs of trial participation; those who opted out after judging that disadvantages outweighed advantages are termed ‘trial decliners’. Across all stages, most individuals declined because they judged themselves ineligible or not in need of the trial therapy. While ‘prior decliners’ are unlikely to respond to any trial recruitment initiative, the factors leading others to decline are amenable to amelioration as they do not arise from a rejection of trials or a personal stance. Conclusions To improve recruitment in similar trials, the most successful interventions are likely to address patients’ assessments of their eligibility and their potential to benefit from the trial treatment, rather than reducing trial burden

Robust nuclear lamina-based cell classification of aging and senescent cells

Changes in the shape of the nuclear lamina are exhibited in senescent cells, as well as in cells expressing mutations in lamina genes. To identify cells with defects in the nuclear lamina we developed an imaging method that quantifies the intensity and curvature of the nuclear lamina. We show that this method accurately describes changes in the nuclear lamina. Spatial changes in nuclear lamina coincide with redistribution of lamin A proteins and local reduction in protein mobility in senescent cell. We suggest that local accumulation of lamin A in the nuclear envelope leads to bending of the structure. A quantitative distinction of the nuclear lamina shape in cell populations was found between fresh and senescent cells, and between primary myoblasts from young and old donors. Moreover, with this method mutations in lamina genes were significantly distinct from cells with wild-type genes. We suggest that this method can be applied to identify abnormal cells during aging, in in vitro propagation, and in lamina disorders