Inertial motion on the earth's spheroidal surface.

As seen by an observer in the rotating frame, the earth's small spheroidal deformations neutralize the centrifugal force, leaving only the smaller Coriolis force to govern the "inertial" motion of objects that move on its surface, assumed smooth and frictionless. Previous studies of inertial motion employ weakly spheroidal equations of motion that ignore the influence of the centrifugal force and yet treat the earth as a sphere. The latitude dependence of these equations renders them strongly nonlinear. We derive and justify these equations and use them to identify, classify, name, describe, and illustrate all possible classes of inertial motion, including a new class of motion called circumpolar waves, which encircle both poles during each cycle of the motion. We illustrate these classes using CorioVis, our freely available Coriolis visualization software. We identify a rotational/time-reversal symmetry for motion on the earth's surface and use this symmetry to develop and validate closed-form small-amplitude approximations for the four main classes and one degenerate class of inertial motion. For these five classes, we supply calculations of experimentally relevant frequencies, zonal drifts, and latitude ranges.

A Web-based Educational Intervention to Increase Perianesthesia Nurses' Knowledge, Attitude, and Intention to Promote Safe Use, Storage, and Disposal of Opioids.

PURPOSE: The purpose of this study was to determine if a web-based educational intervention increased knowledge, attitudes, and intention of perianesthesia nurses regarding opioid discharge education (including safe use, storage, and disposal of opioids). Secondary outcomes were to determine Perceived Behavioral Control, subjective norms, and familiarity with American Society of PeriAnesthesia Nurses (ASPAN) guidance on opioid education. DESIGN: A pre-test, post-test longitudinal design. METHODS: An email described the study and had a link for those choosing to participate. The intervention was a web-based voiceover module with patient education scenarios focused on information required for patients before discharge home. Responses to the evidence-based pre-survey, post-survey one, and post-survey two were collected. The survey was developed using components of the Theory of Planned Behavior. Data analysis included descriptive summary and evaluation of changes in knowledge and domains of Theory of Planned Behavior using repeated measures mixed modeling. FINDINGS: The participants were invited to complete a pre-test survey (n = 672), the immediate post-test (n = 245), and the 4-week post-test (n = 172). The analysis presented is limited to 245 who completed at least the first post-survey. Most were staff nurses (82%), and the majority had a BSN (62%); participants most typically worked in a hospital-based PACU (73%). For all outcomes, there was an immediate increase in the measure following the intervention; this pairwise difference (between pretest and the immediate post-test) was significant in all but one of the models. The immediate and 4-week post-test scores exceeded the corresponding pre-test score, though for Perceived Behavioral Control, attitude, and intention, the degree of increase between baseline and week 4 was not significant. CONCLUSIONS: In all cases, both the immediate and 4-week post-test scores exceeded the corresponding pre-test score, though, for three of the TPB constructs, the difference between baseline and week 4 was not significant, while nearly all of the increases between baseline and immediately following the intervention were significant. These findings suggest a more intensive intervention, possibly with the inclusion of booster sessions, may be needed.

Compliance With Opioid Disposal Following Opioid Disposal Education in Surgical Patients: A Systematic Review.

PURPOSE: The present opioid epidemic in the United States is a significant cause for concern in healthcare. In 1995, the concept of pain was introduced as the fifth vital sign. Since then, the sales of opioids have increased dramatically, as have the number of opioid deaths. The misuse and diversion of retained opioids following surgical procedures contribute to the problem. The objective of this project was to review the latest scholarly work and evaluate the findings related to patient education and disposal of opioid medications to decrease opioid misuse and increase disposal. DESIGN: A systematic review. METHODS: The systematic search strategy included PubMed, Ovid Technologies (OVID), and Cumulative Index of Nursing and Allied Health Literature (CINAHL) electronic databases. FINDINGS: A total of 4 randomized controlled trials (RCTs), 2 quasi-experimental studies, and 2 quality improvement projects met the criteria for inclusion. The studies found that as many as 92% of patients had leftover unused opioids. The retention rate of opioids among surgical patients was found to be 33 to 95%. When educational material was provided about disposal, the studies found that the disposal rate was as high as 71%. CONCLUSIONS: Patient education about opioid misuse, diversion, and disposal are essential topics that need to be addressed with patients and caregivers.

Surgical Patient Compliance With Healthcare Facility-Provided In-home Opioid Disposal Products: A Systematic Review.

OBJECTIVE: The aim of this study was to review the literature regarding the use of an in-home opioid disposal product on unused opioids after surgery. BACKGROUND: The opioid epidemic in the United States is a major cause of concern for healthcare facilities. The misuse and diversion of retained opioids after a surgical procedure continues to contribute to this problem. METHODS: A comprehensive search of the Cumulative Index of Nursing and Allied Health Literature, OVID, and PubMed databases with keywords including opioid, analgesics, narcotics, medical waste disposal, medical disposal, refuse disposal, and opioid disposal resulted in 286 articles. Articles were screened based on strict inclusion and exclusion criteria. RESULTS: Eight studies determined that an in-home opioid disposal product provided by a healthcare facility produced rates of opioid disposal between 19% and 71%. CONCLUSIONS: The provision of an in-home opioid disposal product by a healthcare facility is likely to increase the disposal of unused opioid medications in the postoperative surgical patient population.

The Role of a Certified Registered Nurse Anesthetist Led Acute Pain Service in Preventing Persistent Postoperative Opioid Use.

Given the present opioid crisis, the use of opioids in the hospital setting is an increasing concern among hospital administrators and healthcare professionals. A serious problem related to surgical care is persistent postoperative opioid use among previously opioid-naïve patients. Certified registered nurse anesthetists (CRNAs) are strategically positioned within the hospital setting to address these concerns. These individuals are actively involved in managing the pain of their patients and can therefore lead change in relation to the opioid crisis. This article profiles a multidisciplinary acute pain service developed in a Magnet redesignated hospital led by CRNAs that has demonstrated positive outcomes in decreasing the use of opioids postprocedure and postdischarge, education for healthcare providers, information for community members related to opioid abuse, and support of new protocols, including Enhanced Recovery After Surgery.

Periodic bouncing modes for two uniformly magnetized spheres. II. Scaling.

A uniformly magnetized sphere moves without friction in a plane in response to the field of a second, identical, fixed sphere and makes elastic hard-sphere collisions with this sphere. Numerical simulations of the threshold energies and periods of periodic finite-amplitude nonlinear bouncing modes agree with small-amplitude closed-form mathematical results, which are used to identify scaling parameters that govern the entire amplitude range, including power-law scaling at large amplitudes. Scaling parameters are combinations of the bouncing number, the rocking number, the phase, and numerical factors. Discontinuities in the scaling functions are found when viewing the threshold energy and period as separate functions of the scaling parameters, for which large-amplitude scaling exponents are obtained from fits to the data. These discontinuities disappear when the threshold energy is viewed as a function of the threshold period, for which the large-amplitude scaling exponent is obtained analytically and for which scaling applies to both in-phase and out-of-phase modes.

Periodic bouncing modes for two uniformly magnetized spheres. I. Trajectories.

We consider a uniformly magnetized sphere that moves without friction in a plane in response to the field of a second, identical, fixed sphere, making elastic hard-sphere collisions with this sphere. We seek periodic solutions to the associated nonlinear equations of motion. We find closed-form mathematical solutions for small-amplitude modes and use these to characterize and validate our large-amplitude modes, which we find numerically. Our Runge-Kutta integration approach allows us to find 1243 distinct periodic modes with the free sphere located initially at its stable equilibrium position. Each of these modes bifurcates from the finite-amplitude radial bouncing mode with infinitesimal-amplitude angular motion and supports a family of states with increasing amounts of angular motion. These states offer a rich variety of behaviors and beautiful, symmetric trajectories, including states with up to 157 collisions and 580 angular oscillations per period.

19F Dark-State Exchange Saturation Transfer NMR Reveals Reversible Formation of Protein-Specific Large Clusters in High-Concentration Protein Mixtures.

Proteins frequently exist as high-concentration mixtures, both in biological environments and increasingly in biopharmaceutical co-formulations. Such crowded conditions promote protein-protein interactions, potentially leading to formation of protein clusters, aggregation, and phase separation. Characterizing these interactions and processes in situ in high-concentration mixtures is challenging due to the complexity and heterogeneity of such systems. Here we demonstrate the application of the dark-state exchange saturation transfer (DEST) NMR technique to a mixture of two differentially 19F-labeled 145 kDa monoclonal antibodies (mAbs) to assess reversible temperature-dependent formation of small and large protein-specific clusters at concentrations up to 400 mg/mL. 19F DEST allowed quantitative protein-specific characterization of the cluster populations and sizes for both mAbs in the mixture under a range of conditions. Additives such as arginine glutamate and NaCl also had protein-specific effects on the dark-state populations and cluster characteristics. Notably, both mAbs appear to largely exist as separate self-associated clusters, which mechanistically respond differently to changes in solution conditions. We show that for mixtures of differentially 19F-labeled proteins DEST NMR can characterize clustering in a protein-specific manner, offering unique tracking of clustering pathways and a means to understand and control them.

Use of 19 F Differential Labelling for the Simultaneous Detection and Monitoring of Three Individual Proteins in a Serum Environment.

Protein behavior in complex mixtures, such as biological fluids, is often modeled by simplified buffer systems in solution. Here we have used the recently described differential 19 F labelling approach (with NMR detection) to monitor and compare the solution behaviour of three proteins at once: human serum albumin (HSA), transferrin (TrF), and immunoglobulin G (IgG), both in serum and in buffer. We demonstrate that monitoring three proteins simultaneously and independently in biological fluid is possible, and that the presence of other endogenous components greatly changes the association characteristics of these proteins. For example, in the simplified model buffer system, all three proteins diffuse at a similar rate, while in serum HSA diffuses around three times faster than TrF, and four times faster than IgG. This 19 F NMR approach allows characterization of the behaviour of complex multiprotein systems in their native environment, e. g., in biological fluids.

Publisher Correction: Critical Southern Ocean climate model biases traced to atmospheric model cloud errors.

'In the original HTML version of this Article, ref.12 was incorrectly cited in the first sentence of the first paragraph of the Introduction. The correct citation is ref. 2. This has now been corrected in the HTML version of the Article; the PDF version was correct at the time of publication.'

Critical Southern Ocean climate model biases traced to atmospheric model cloud errors.

The Southern Ocean is a pivotal component of the global climate system yet it is poorly represented in climate models, with significant biases in upper-ocean temperatures, clouds and winds. Combining Atmospheric and Coupled Model Inter-comparison Project (AMIP5/CMIP5) simulations, with observations and equilibrium heat budget theory, we show that across the CMIP5 ensemble variations in sea surface temperature biases in the 40-60°S Southern Ocean are primarily caused by AMIP5 atmospheric model net surface flux bias variations, linked to cloud-related short-wave errors. Equilibration of the biases involves local coupled sea surface temperature bias feedbacks onto the surface heat flux components. In combination with wind feedbacks, these biases adversely modify upper-ocean thermal structure. Most AMIP5 atmospheric models that exhibit small net heat flux biases appear to achieve this through compensating errors. We demonstrate that targeted developments to cloud-related parameterisations provide a route to better represent the Southern Ocean in climate models and projections.

19F NMR as a Tool for Monitoring Individual Differentially Labeled Proteins in Complex Mixtures.

The ability to monitor the behavior of individual proteins in complex mixtures has many potential uses, ranging from analysis of protein interactions in highly concentrated solutions, modeling biological fluids or the intracellular environment, to optimizing biopharmaceutical co-formulations. Differential labeling NMR approaches, which traditionally use 15N or 13C isotope incorporation during recombinant expression, are not always practical in cases when endogenous proteins are obtained from an organism, or where the expression system does not allow for efficient labeling, especially for larger proteins. This study proposes differential labeling of proteins by covalent attachment of 19F groups with distinct chemical shifts, giving each protein a unique spectral signature which can be monitored by 19F NMR without signal overlap, even in complex mixtures, and without any interfering signals from the buffer or other unlabeled components. Parameters, such as signal intensities, translational diffusion coefficients, and transverse relaxation rates, which report on the behavior of individual proteins in the mixture, can be recorded even for proteins as large as antibodies at a wide range of concentrations.

Evaluation of satellite and reanalysis-based global net surface energy flux and uncertainty estimates.

The net surface energy flux is central to the climate system yet observational limitations lead to substantial uncertainty. A combination of satellite-derived radiative fluxes at the top of atmosphere adjusted using the latest estimation of the net heat uptake of the Earth system, and the atmospheric energy tendencies and transports from the ERA-Interim reanalysis are used to estimate surface energy flux globally. To consider snowmelt and improve regional realism, land surface fluxes are adjusted through a simple energy balance approach at each grid point. This energy adjustment is redistributed over the oceans to ensure energy conservation and maintain realistic global ocean heat uptake, using a weighting function to avoid meridional discontinuities. Calculated surface energy fluxes are evaluated through comparison to ocean reanalyses. Derived turbulent energy flux variability is compared with the Objectively Analyzed air-sea Fluxes (OAFLUX) product, and inferred meridional energy transports in the global ocean and the Atlantic are also evaluated using observations. Uncertainties in surface fluxes are investigated using a variety of approaches including comparison with a range of atmospheric reanalysis products. Decadal changes in the global mean and the interhemispheric energy imbalances are quantified, and present day cross-equator heat transports are reevaluated at 0.22 ± 0.15 PW (petawatts) southward by the atmosphere and 0.32 ± 0.16 PW northward by the ocean considering the observed ocean heat sinks.

Periodic nonlinear sliding modes for two uniformly magnetized spheres.

A uniformly magnetized sphere slides without friction along the surface of a second, identical sphere that is held fixed in space, subject to the magnetic force and torque of the fixed sphere and the normal force. The free sphere has two stable equilibrium positions and two unstable equilibrium positions. Two small-amplitude oscillatory modes describe the sliding motion of the free sphere near each stable equilibrium, and an unstable oscillatory mode describes the motion near each unstable equilibrium. The three oscillatory modes remain periodic at finite amplitudes, one bifurcating into mixed modes and circumnavigating the free sphere at large energies. For small energies, the free sphere is confined to one of the two discontiguous domains, each surrounding a stable equilibrium position. At large energies, these domains merge and the free sphere may visit both positions. The critical energy at which these domains merge coincides with the cumulation point of an infinite cascade of mixed-mode bifurcations. These findings exploit the equivalence of the force and torque between two uniformly magnetized spheres and the force and torque between two equivalent point dipoles, and offer clues to the rich nonlinear dynamics of this system. Online MagPhyx visualizations illustrate the dynamics.

An internal thioester in a pathogen surface protein mediates covalent host binding.

To cause disease and persist in a host, pathogenic and commensal microbes must adhere to tissues. Colonization and infection depend on specific molecular interactions at the host-microbe interface that involve microbial surface proteins, or adhesins. To date, adhesins are only known to bind to host receptors non-covalently. Here we show that the streptococcal surface protein SfbI mediates covalent interaction with the host protein fibrinogen using an unusual internal thioester bond as a 'chemical harpoon'. This cross-linking reaction allows bacterial attachment to fibrin and SfbI binding to human cells in a model of inflammation. Thioester-containing domains are unexpectedly prevalent in Gram-positive bacteria, including many clinically relevant pathogens. Our findings support bacterial-encoded covalent binding as a new molecular principle in host-microbe interactions. This represents an as yet unexploited target to treat bacterial infection and may also offer novel opportunities for engineering beneficial interactions.

Structural insights into the targeting of mRNA GU-rich elements by the three RRMs of CELF1.

The CUG-BP, Elav-like family (CELF) of RNA-binding proteins control gene expression at a number of different levels by regulating pre-mRNA splicing, deadenylation and mRNA stability. We present structural insights into the binding selectivity of CELF member 1 (CELF1) for GU-rich mRNA target sequences of the general form 5'-UGUNxUGUNyUGU and identify a high affinity interaction (Kd ∼ 100 nM for x = 2 and y = 4) with simultaneous binding of all three RNA recognition motifs within a single 15-nt binding element. RNA substrates spin-labelled at either the 3' or 5' terminus result in differential nuclear magnetic resonance paramagnetic relaxation enhancement effects, which are consistent with a non-sequential 2-1-3 arrangement of the three RNA recognition motifs on UGU sites in a 5' to 3' orientation along the RNA target. We further demonstrate that CELF1 binds to dispersed single-stranded UGU sites at the base of an RNA hairpin providing a structural rationale for recognition of CUG expansion repeats and splice site junctions in the regulation of alternative splicing.

Saturation transfer difference NMR reveals functionally essential kinetic differences for a sugar-binding repressor protein.

The binding kinetics of disaccharides trehalose and trehalose-6-phosphate to repressor protein TreR have been determined using STD NMR and shed light on the contrasting biological roles of these two sugars.

Thin film electro-osmotic pumps for biomicrofluidic applications.

Electro-osmotic flow (EOF) pumps are attractive for fluid manipulation in microfluidic channels. Open channel EOF pumps can produce high pressures and flow rates, and are relatively easy to fabricate on-chip or integrate with other microfluidic or electrical components. An EOF pump design that is conducive to on-chip fabrication consists of multiple small channel arms feeding into a larger flow channel. We have fabricated this type of pump design using a thin film deposition process that avoids wafer bonding. We have evaluated pumps fabricated on both silicon and glass substrates. Consistent flow rate versus electric field were obtained. For the range of 40-400 V, flow rates of 0.19-2.30 muLmin were measured. Theoretical calculations of pump efficiency were made, as well as calculations of the mechanical power generated by various pump shapes, to investigate design parameters that should improve future pumps.

Electroosmotic flow in vapor deposited silicon dioxide and nitride microchannels.

Electroosmotic flow was studied in thin film microchannels with silicon dioxide and silicon nitride sidewalls formed using plasma-enhanced chemical vapor deposition (PECVD). A sacrificial etching process was employed for channel fabrication allowing for cross-sections with heights of 3 mum, ranging from 2 mum to 50 mum in width. Flow rates were measured for single channels and multichannel electroosmotic pump structures for pH levels ranging from 2.6 to 8.3, and zeta potentials were calculated for both silicon dioxide and silicon nitride surfaces. Flow rates as high as 0.086 muLmin were measured for nitride multichannel pumps at applied electric fields of 300 Vmm. The surface characteristics of PECVD nitride were analyzed and compared to more well-known oxide surfaces to determine the density of amine sites compared to silanol sites.

The anterior cardiac plexus: an intrinsic neurosecretory site within the stomatogastric nervous system of the crab Cancer productus.

The stomatogastric nervous system (STNS) of decapod crustaceans is modulated by both locally released and circulating substances. In some species, including chelate lobsters and freshwater crayfish, the release zones for hormones are located both intrinsically to and at some distance from the STNS. In other crustaceans, including Brachyuran crabs, the existence of extrinsic sites is well documented. Little, however, is known about the presence of intrinsic neuroendocrine structures in these animals. Putative intrinsic sites have been identified within the STNS of several crab species, though ultrastructural confirmation that these structures are in fact neuroendocrine in nature remains lacking. Using a combination of anatomical techniques, we demonstrate the existence of a pair of neurosecretory sites within the STNS of the crab Cancer productus. These structures, which we have named the anterior cardiac plexi (ACPs), are located on the anterior cardiac nerves (acns), which overlie the cardiac sac region of the foregut. Each ACP starts several hundred micro m from the origin of the acn and extends distally for up to several mm. Transmission electron microscopy done on these structures shows that nerve terminals are present in the peripheral portion of each acn, just below a well defined epineurium. These terminals contain dense-core and, occasionally, electron-lucent vesicles. In many terminals, morphological correlates of hormone secretion are evident. Immunocytochemistry shows that the ACPs are immunopositive for FLRFamide-related peptide. All FLRFamide labeling in the ACPs originates from four axons, which descend to these sites through the superior oesophageal and stomatogastric nerves. Moreover, these FLRFamide-immunopositive axons are the sole source of innervation to the ACPs. Collectively, our results suggest that the STNS of C. productus is not only a potential target site for circulating hormones, but also serves as a neuroendocrine release center itself.