Local field potentials (LFPs) in primary motor cortex include significant information about reach target location and upper limb movement kinematics. Some evidence suggests that they may be a more ...robust, longer-lasting signal than action potentials (spikes). Here we assess whether LFPs can also be used to decode upper limb muscle activity, a complex movement-related signal. We record electromyograms from both proximal and distal upper limb muscles from monkeys performing a variety of reach-to-grasp and isometric wrist force tasks. We show that LFPs can be used to decode activity from both proximal and distal muscles with performance rivaling that of spikes. Thus, motor cortical LFPs include information about more aspects of movement than has been previously demonstrated. This provides further evidence suggesting that LFPs could provide a highly informative, long-lasting signal source for neural prostheses.
A multidisciplinary international working subgroup of the third Perioperative Quality Initiative consensus meeting appraised the evidence on the influence of preoperative arterial blood pressure and ...community cardiovascular medications on perioperative risk.
A modified Delphi technique was used, evaluating papers published in MEDLINE on associations between preoperative numerical arterial pressure values or cardiovascular medications and perioperative outcomes. The strength of the recommendations was graded by National Institute for Health and Care Excellence guidelines.
Significant heterogeneity in study design, including arterial pressure measures and perioperative outcomes, hampered the comparison of studies. Nonetheless, consensus recommendations were that (i) preoperative arterial pressure measures may be used to define targets for perioperative management; (ii) elective surgery should not be cancelled based solely upon a preoperative arterial pressure value; (iii) there is insufficient evidence to support lowering arterial pressure in the immediate preoperative period to minimise perioperative risk; and (iv) there is insufficient evidence that any one measure of arterial pressure (systolic, diastolic, mean, or pulse) is better than any other for risk prediction of adverse perioperative events.
Future research should define which preoperative arterial pressure values best correlate with adverse outcomes, and whether modifying arterial pressure in the preoperative setting will change the perioperative morbidity or mortality. Additional research should define optimum strategies for continuation or discontinuation of preoperative cardiovascular medications.
We present a compilation of endocranial volumes (ECV) for 176 non-human primate species based on individual data collected from 3813 museum specimens, at least 88% being wild-caught. In combination ...with body mass data from wild individuals, strong correlations between endocranial volume and body mass within taxonomic groups were found. Errors attributable to different techniques for measuring cranial capacity were negligible and unbiased. The overall slopes for regressions of log ECV on log body mass in primates are 0.773 for least-squares regression and 0.793 for reduced major axis regression. The least-squares slope is reduced to 0.565 when independent contrasts are substituted for species means (branch lengths from molecular studies). A common slope of 0.646 is obtained with logged species means when grade shifts between major groups are taken into account using ANCOVA. In addition to providing a comprehensive and reliable database for comparative analyses of primate brain size, we show that the scaling relationship between brain mass and ECV does not differ significantly from isometry in primates. We also demonstrate that ECV does not differ substantially between captive and wild samples of the same species. ECV may be a more reliable indicator of brain size than brain mass, because considerably larger samples can be collected to better represent the full range of intraspecific variation. We also provide support for the maternal energy hypothesis by showing that basal metabolic rate (BMR) and gestation period are both positively correlated with brain size in primates, after controlling for the influence of body mass and potential effects of phylogenetic relatedness.
This study presents evidence of diel patterns in fin whale (
) 20 Hz acoustic presence in Eastern Antarctic waters. Passive acoustic recordings were collected at four sites in Eastern Antarctica from ...2013 to 2019. A generalized linear model fitted by a generalized estimating equation was used to test the hypothesis that fin whale 20 Hz acoustic presence shows significant variation between light regimes dawn, day, dusk and night. In the Indian sector of Antarctica, at the Prydz and Southern Kerguelen Plateau sites, fin whale acoustic presence was significantly more common during the night and dawn before declining during the day and dusk periods. A different diel pattern was observed in the Pacific sector, at the Dumont d'Urville site: fin whale acoustic presence was significantly more common during the day than dusk and night periods. No diel pattern was identified at the Casey site. The identified diel patterns in the Indian sector of Eastern Antarctica correlate with previously identified diel patterns of the fin whales' prey. We suggest an indirect association between fin whale acoustic presence and foraging, with the animals more likely to produce the 20 Hz pulse during the night when not foraging and less likely to vocalize when foraging during the day.
The etiology and natural history of Parkinson's disease (PD) are not well understood. Some non-motor symptoms such as hyposmia, rapid eye movement sleep behavior disorder, and constipation may ...develop during the prodromal stage of PD and precede PD diagnosis by years.
We examined the promise and pitfalls of research on premotor symptoms of PD and developed priorities and strategies to understand their clinical and etiological implications.
This review was based on a workshop, Parkinson's Disease Premotor Symptom Symposium, held 7-8 June 2012 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina.
Research on premotor symptoms of PD may offer an excellent opportunity to characterize high-risk populations and to better understand PD etiology. Such research may lead to evaluation of novel etiological hypotheses such as the possibility that environmental toxicants or viruses may initiate PD pathogenesis in the gastrointestinal tract or olfactory bulb. At present, our understanding of premotor symptoms of PD is in its infancy and faces many obstacles. These symptoms are often not specific to PD and have low positive predictive value for early PD diagnosis. Further, the pathological bases and biological mechanisms of these premotor symptoms and their relevance to PD pathogenesis are poorly understood.
This is an emerging research area with important data gaps to be filled. Future research is needed to understand the prevalence of multiple premotor symptoms and their etiological relevance to PD. Animal experiments and mechanistic studies will further understanding of the biology of these premotor symptoms and test novel etiological hypothesis.
The aim of this study was to provide consensus recommendations from residency program leaders on letters of intent (LOIs) written by postgraduate year 1 (PGY1) pharmacy residency candidates.
A ...3-round modified Delphi process was used to determine consensus among PGY1 residency program leaders across the country. A screening and demographic survey was utilized to ensure representation of panelists. The initial items for round 1 of the study were developed using existing published literature, with pilot testing by 2 residency program directors. For each round, respondents rated items on a 7-point Likert scale, with opportunities to provide qualitative feedback and modifications for lower-rated items. For future rounds, items were adjusted based on respondent feedback. Only items meeting predefined consensus were included in the final recommendations.
A total of 254 pharmacists were invited to participate in the panel, with 41 completing the demographic and study consent survey. There were 35 participants in round 1, 34 of whom remained for rounds 2 and 3. The panel created 18 LOI recommendations for PGY1 residency candidates. Most recommendations were focused on the content of the LOI, while others were related to formatting.
The recommendations from this study can be employed by PGY1 pharmacy residency candidates to enhance their likelihood of success in the residency application process.
In Search of Low-k Dielectrics Miller, Robert D.
Science (American Association for the Advancement of Science),
10/1999, Volume:
286, Issue:
5439
Journal Article
Peer reviewed
Within the next few years, high-performance chips containing as many as 0.5 billion transistors on a single chip will be produced. Any replacement low-k material must meet the current integration ...requirements.
Milk provides mammalian neonates with nutritional support and passive immunity. This is particularly true in marsupials where young are born highly altricial and lacking many components of a fully ...functional adaptive immune system. Here we investigated the T cell populations in the mammaries of a lactating marsupial, the gray short-tailed opossum Monodelphis domestica. Immunohistochemistry confirmed the presence of T cells within the opossum mammaries throughout lactation. Results of quantifying transcript abundance for lymphocyte markers are consistent with γδ T cells being the most common T cell type within lactating mammaries. Numbers of γδ T cells appear to peak early during the first postnatal week, and then decline throughout lactation until weaning. In contrast, numbers of αβ T cells and γμ T cells appear to be low to non-existent in the lactating mammaries. The results support an ancient and conserved role of immune cells in the evolution and function of mammalian mammary tissue.
•T cells are present in opossum mammaries throughout lactation.•γδ T Cells are the predominate T cell subset in the mammaries.•Abundant γδ T cells correspond to mammary development.•Presence of mammary γδ T cells appears to be ancient and conserved amongst mammals.
Background:
Anterior closing wedge osteotomy of the proximal tibia may be considered in revision anterior cruciate ligament (ACL) reconstruction surgery for patients with excessive posterior tibial ...slope (PTS).
Purpose:
(1) To determine the ratio of wedge thickness to degrees of correction for supratubercle (ST) versus transtubercle (TT) osteotomies for anterior closing wedge osteotomies and (2) to evaluate the accuracy of ST and TT osteotomies in achieving slope correction.
Study Design:
Controlled laboratory study.
Methods:
The computed tomography (CT) scans of 38 knees in 37 patients undergoing revision ACL reconstruction were used to simulate both ST and TT osteotomies. A 10° wedge was simulated in all CT models. The height of the wedge along the anterior tibia was recorded for each of the 2 techniques. The ratio of wedge height to achieved degree of correction was calculated. ST and TT osteotomies were performed on 3-dimensional (3D)–printed tibias of the 12 patients from the study group with the greatest PTS, after the desired degree of correction was determined. Pre- and postosteotomy slopes were measured for each tibia, and the actual change in slope was compared with the intended slope correction.
Results:
According to CT measurements, the ratio of wedge height to degree of correction was 0.99 ± 0.07 mm/deg for the ST osteotomy and 0.83 ± 0.06 mm/deg for the TT osteotomy (P < .001). When these ratios were used to perform simulated osteotomies on the twelve 3D-printed tibias, the mean slope correction was within 1° to 2° of the intended slope correction, regardless of osteotomy location (ST or TT) or whether slope was measured on the medial or lateral plateau. The ST technique tended to undercorrect and the TT technique tended to overcorrect.
Conclusion:
When anterior tibial closing wedge osteotomies were removed to correct excessive PTS, removing a wedge with a ratio of 1 mm of wedge height for every 1° of intended correction for an ST technique and a ratio of 0.8 mm to 1° for a TT technique resulted in overall average slope correction within 1° to 2° of the target.
Clinical Relevance:
The calculated ratios will allow clinicians to more accurately correct PTS when performing anterior closing wedge tibial osteotomy.
By accounting for surface-based light source emissions and
top-of-atmosphere (TOA) downward lunar fluxes, we adapted the spherical
harmonics discrete ordinate method (SHDOM) 3-dimensional (3-D) ...radiative
transfer model (RTM) to simulate nighttime 3-D TOA radiances as observed
from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band
(DNB) on board the Suomi-NPP satellite platform. Used previously for daytime
3-D applications, these new SHDOM enhancements allow for the study of the
impacts of various observing conditions and aerosol properties on simulated
VIIRS-DNB TOA radiances. Observations over Dakar, Senegal, selected for its
bright city lights and a large range of aerosol optical depth (AOD), were
investigated for potential applications and opportunities for using observed radiances containing VIIRS-DNB “bright pixels” from artificial light sources to conduct aerosol retrievals. We found that using the standard deviation (SD) of such bright pixels provided a more stable quantity for nighttime AOD retrievals than direct retrievals from TOA radiances. Further, both the
mean TOA radiance and SD of TOA radiances over artificial sources are
significantly impacted by satellite viewing angles. Light domes, the
enhanced radiances adjacent to artificial light sources, are strong
functions of aerosol properties and especially aerosol vertical distribution, which may be further utilized for retrieving aerosol layer
height in future studies. Through inter-comparison with both day- and
nighttime Aerosol Robotic Network (AERONET) data, the feasibility of
retrieving nighttime AODs using 3-D RTM SHDOM over artificial light sources
was demonstrated. Our study shows strong potential for using artificial
light sources for nighttime AOD retrievals, while also highlighting larger
uncertainties in quantifying surface light source emissions. This study
underscores the need for surface light emission source characterizations as
a key boundary condition, which is a complex task that requires enhanced
input data and further research. We demonstrate how quality-controlled
nighttime light data from the NASA's Black Marble product suite could serve
as a primary input into estimations of surface light source emissions for
nighttime aerosol retrievals.
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