Femoral Component Rotation in Total Knee Arthroplasty Using a Tibia-First, Gap-Balancing, “Functional Alignment” Technique

Background: The purpose of this study was to describe the femoral component rotation in total knee arthroplasty (TKA) using a tibia-first, gap-balancing, “functional alignment” technique. Methods: Ninety-seven patients with osteoarthritis received a TKA using computer navigation. The tibial resection was performed according to the kinematic alignment (KA) principles, while the femoral rotation was set according to the gap-balancing technique. Preoperative MRIs and intraoperative resection depth data were used to calculate the following rotational axes: the transepicondylar axis (TEA), the posterior condylar axis (PCA) and the prosthetic posterior condylar axis (rPCA). The angles between the PCA and the TEA (PCA/TEA), between the rPCA and the PCA (rPCA/PCA) and between the rPCA and the TEA (rPCA/TEA) were measured. Data regarding patellar maltracking and PROMs were collected for 24 months postoperatively. Results: The mean PCA/TEA, rPCA/TEA and rPCA/PCA angles were −5.1° ± 2.1°, −4.8° ± 2.6° and −0.4° ± 1.7°, respectively (the negative values denote the internal rotation of the PCA to the TEA, rPCA to TEA and rPCA to PCA, respectively). There was no need for lateral release and no cases of patellar maltracking. Conclusions: A tibia-first, gap-balancing, “functional alignment” approach allows incorporating a gap-balancing technique with kinematic principles. Sagittal complexities in the proximal tibia (variable medial and lateral slopes) can be accounted for, as the tibial resection is completed prior to setting the femoral rotation. The prosthetic femoral rotation is internally rotated relative to the TEA, almost parallel to the PCA, similar to the femoral rotation of the KA-TKA technique. This technique did not result in patellar maltracking

Image-derived instrumentation vs. conventional instrumentation with 3D planning for glenoid component placement in reverse total shoulder replacements: a randomized controlled trial

Hypothesis: Glenoid baseplate positioning for reverse total shoulder arthroplasty (rTSA) is important for stability and longevity, with techniques such as image-derived instrumentation (IDI) developed for improving implant placement accuracy. We performed a single-blinded randomized controlled trial comparing glenoid baseplate insertion accuracy with 3D preoperative planning and IDI jigs vs. 3D preoperative planning and conventional instrumentation. Methods: All patients had a preoperative 3D computed tomography to create an IDI; then underwent rTSA according to their randomized method. Repeat computed tomography scans performed at six weeks postoperatively were compared to the preoperative plan to assess for accuracy of implantation. Patient-reported outcome measures and plain radiographs were collected with 2-year follow-up. Results: Forty-seven rTSA patients were included (IDI n = 24, conventional instrumentation n = 23). The IDI group was more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane (P = .01); and exhibited a smaller degree of error when the native glenoid retroversion was >10° (P = .047). There was no difference in patient-reported outcome measures or other radiographic parameters between the two groups. Conclusion: IDI is an accurate method for glenoid guidewire and component placement in rTSA, particularly in the superior/inferior plane and in glenoids with native retroversion >10°, when compared to conventional instrumentation

Tectonic and Topographic Framework of Political Division

Boundaries between the various topographic, geologic, and socio-political entities that span the Earth’s continental surfaces are determined by a myriad of complexly interrelated natural and/or cultural factors. Areas of large river basins, of lithologic units on geologic maps, and of nations exhibit size frequency distributions that are closely approximated by density functions in which diameters of individual areas are distributed exponentially. As such, size distributions of each type of surface unit are closely modeled as randomly delimited areas. In other words, if one were to walk in a straight line across any particular continent, each step along that transect would embody some random continuous probability of passing out of a major drainage basin, or out of an area of more or less homogeneous rock type, or from one country to another. Moreover, this simple truism gives rise to area frequency distributions for large river basin or outcrop or nation area that are primarily dependent on the number of basins or outcrops or countries that exist across that particular landmass. As a consequence, the size frequencies of these areal units can be closely predicted knowing only the total area under consideration and the number of drainage basins, outcrop areas, or nations that exist within the area. The similarity between area frequencies of large river basins and rock types and nations suggests a nontrivial component of geologic influence on the partitioning of continental surfaces into major political divisions, and implies that cultural and economic factors, which serve to divide and unite political entities, do so within a geological framework.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43200/1/11004_2005_Article_1309.pd

Light Therapy Device for Entrainment of Circadian Rhythm Desynchronization in Microgravity

The circadian rhythm is an internal process of the brain that regulates the sleep-wake cycle. Outside environmental factors can affect the circadian rhythm such as light and dark. In microgravity, astronauts witness the sun rise and set approximately 16 times per day. A disruption (desynchronization) of the circadian rhythm may then occur, with some astronauts reporting to be less alert and unable to sufficiently complete tasks. PURPOSE: To design, fabricate, and test a pair of glasses that emit blue wavelengths of light peripheral to the eyes, for set periods of time, which may promote alertness in astronauts. METHODS: The custom fitted glasses were originally designed in three-dimensional modeling software (Solidworks Premium, Waltham, MA). Components of the glasses included: frames, an Arduino Nano circuit board, tactile button switch, inductive charging components and battery, a wireless charging transmitter, and blue LEDs. The glasses emit 1000 lux at approximately 468 nm wavelength of blue light. The glasses were programmed using C++ to allow the user to wear the glasses for 30 minutes with an automatic timer to turn off the lights upon completion of the session. When fully charged, the battery can sustain a total of 8 sessions with each lasting 30 minutes. To further assess the functionality of the glasses, brainwaves measured via electroencephalography (EEG) and reaction time measured via the psychomotor vigilance test (PVT) were collected before, immediately after, and one hour after a 30-min trial session while wearing the glasses in the “on” position. For one week prior to testing, participants emulated the sleep schedule of astronauts, including a strict adherence to 6.5 hours of sleep each night. Naps, caffeine, and sleep medications were also avoided during this time. RESULTS: For EEG data, morphology of beta wave activation in the frontal lobe noticeably changed after light exposure to a more jagged shape with higher frequency and lower amplitude. The control waveform and the waveform measured before light therapy exhibited greater intermixed frequencies of lower value. With regard to reaction time, when light exposure was administered on test days, participants exhibited faster reaction time responses immediately after (374.2 ± 58.1 msec) and 1-hour post (372.7 ± 65.9 msec) compared to before (530.4 ± 120.4 msec) the glasses were worn. CONCLUSION: Blue light exposure integrated into a customized pair of glasses may elicit faster response times and promote greater levels of alertness both immediately after wearing the glasses for 30 min, and one hour after the glasses have been removed

Witness: The Modern Writer as Witness

Editor\u27s Note [Excerpt] The United States, as a society, is on the brink of profound and positive change. Demographically and culturally, things are improving, and the reason is obvious to people who study history: Conflict pushes us to be better, to strive for principled goals. Consider the inspired eco-advocacy of Greta Thunberg. Or the swearing in of most diverse class of lawmakers in history into the 116th Congress. Or billionaire Robert F. Smith’s pledge to pay off every Morehouse College (in Atlanta, Georgia) student’s debt. Indeed, there are many good people helping and great moments happening in spite of a bleak 24-hour news cycle designed to ruin happiness and to limit our understanding of our human potential. We at Witness see this yearning for transformation in the works we selected. The doorway must be crossed, and the voices and characters we featured in our Winter 2019 issue stand at the vestibule, ready for the light to warm them, primed to fight for that necessary illumination.https://digitalscholarship.unlv.edu/witness/1000/thumbnail.jp

'Me and my bump': an interpretative phenomenological analysis of the experiences of pregnancy for vulnerable women

Eight pregnant women, considered to be ‘vulnerable’ due to exposure to a number of underlying risk factors, participated in semi-structured interviews regarding their experiences of pregnancy and of Mellow Bumps, a 6-week targeted antenatal intervention. Interview transcripts were explored using interpretative phenomenological analysis. The analysis revealed five superordinate themes: pregnancy as a time of reflection; the body being taken over; pregnancy as an emotional rollercoaster; relationships as important; separating identities. Pre- and post-natal attachment theories were found to be useful in interpreting the data. Findings suggest that pregnancy may be ‘normalising’ and provide an important opportunity for building more positive representations of the self. Findings also provide clinical support for the assertion that the attachment relationship begins before birth. The Mellow Bumps intervention was uniformly seen as helpful. It appeared to nurture prenatal attachment relationships, playing a potentially protective role, by helping to establish the foundations for secure mother–infant relationships in the future. Meeting similar women and engaging in ordinary, supportive conversation during Mellow Bumps seemed to reduce feelings of isolation and stigma. Implications for clinical practice are considered

An Evolutionary Reduction Principle for Mutation Rates at Multiple Loci

A model of mutation rate evolution for multiple loci under arbitrary selection is analyzed. Results are obtained using techniques from Karlin (1982) that overcome the weak selection constraints needed for tractability in prior studies of multilocus event models. A multivariate form of the reduction principle is found: reduction results at individual loci combine topologically to produce a surface of mutation rate alterations that are neutral for a new modifier allele. New mutation rates survive if and only if they fall below this surface - a generalization of the hyperplane found by Zhivotovsky et al. (1994) for a multilocus recombination modifier. Increases in mutation rates at some loci may evolve if compensated for by decreases at other loci. The strength of selection on the modifier scales in proportion to the number of germline cell divisions, and increases with the number of loci affected. Loci that do not make a difference to marginal fitnesses at equilibrium are not subject to the reduction principle, and under fine tuning of mutation rates would be expected to have higher mutation rates than loci in mutation-selection balance. Other results include the nonexistence of 'viability analogous, Hardy-Weinberg' modifier polymorphisms under multiplicative mutation, and the sufficiency of average transmission rates to encapsulate the effect of modifier polymorphisms on the transmission of loci under selection. A conjecture is offered regarding situations, like recombination in the presence of mutation, that exhibit departures from the reduction principle. Constraints for tractability are: tight linkage of all loci, initial fixation at the modifier locus, and mutation distributions comprising transition probabilities of reversible Markov chains.Comment: v3: Final corrections. v2: Revised title, reworked and expanded introductory and discussion sections, added corollaries, new results on modifier polymorphisms, minor corrections. 49 pages, 64 reference

The future of mental health nursing: are we barking up the wrong tree?

This commentary has been prompted by a degree of disquiet among the UK mental health nursing community in response to the Shape of Caring Review on the future of nurse education in England (Willis 2015). Proposals for the structure of nurse education have been interpreted as emphasizing generic at the expense of field-specific (e.g. mental health) education, with much specialist training beyond the scope of pre-registration courses (Lintern 2014, Middleton 2015). Specifically, there is a suggestion that student nurses will not enter their specialized field until completing two years of more generalist learning; reminiscent of the previous Project 2000 approach, criticized for supposed inadequate preparation of mental health students because general adult nursing dominated curriculum and teaching (UKCC 1999)

In silico identification of two peptides with antibacterial activity against multidrug-resistant Staphylococcus aureus

Here we report two antimicrobial peptides (AMPs), HG2 and HG4 identified from a rumen microbiome metagenomic dataset, with activity against multidrug-resistant (MDR) bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA) strains, a major hospital and community-acquired pathogen. We employed the classifier model design to analyse, visualise, and interpret AMP activities. This approach allowed in silico discrimination of promising lead AMP candidates for experimental evaluation. The lead AMPs, HG2 and HG4, are fast-acting and show anti-biofilm and anti-inflammatory activities in vitro and demonstrated little toxicity to human primary cell lines. The peptides were effective in vivo within a Galleria mellonella model of MRSA USA300 infection. In terms of mechanism of action, HG2 and HG4 appear to interact with the cytoplasmic membrane of target cells and may inhibit other cellular processes, whilst preferentially binding to bacterial lipids over human cell lipids. Therefore, these AMPs may offer additional therapeutic templates for MDR bacterial infections

In silico identification of two peptides with antibacterial activity against multidrug-resistant Staphylococcus aureus

Here we report two antimicrobial peptides (AMPs), HG2 and HG4 identified from a rumen microbiome metagenomic dataset, with activity against multidrug-resistant (MDR) bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA) strains, a major hospital and community-acquired pathogen. We employed the classifier model design to analyse, visualise, and interpret AMP activities. This approach allowed in silico discrimination of promising lead AMP candidates for experimental evaluation. The lead AMPs, HG2 and HG4, are fast-acting and show anti-biofilm and anti-inflammatory activities in vitro and demonstrated little toxicity to human primary cell lines. The peptides were effective in vivo within a Galleria mellonella model of MRSA USA300 infection. In terms of mechanism of action, HG2 and HG4 appear to interact with the cytoplasmic membrane of target cells and may inhibit other cellular processes, whilst preferentially binding to bacterial lipids over human cell lipids. Therefore, these AMPs may offer additional therapeutic templates for MDR bacterial infections