6,786 research outputs found
An introduction to culturing oysters in Virginia
This document is intended to respond to a growing demand for information on intensive, off-bottom aquaculture of the eastern oyster, Crassostrea virginica, in Virginia and neighboring coastal states. Over the past few years the number of individuals involved in intensive oyster aquaculture in Virginia has increased dramatically, and we now estimate that over 2000 separate off-bottom oyster culture operations are underway within the coastal waters of Virginia. Individuals involved in this activity include non-commercial gardeners, traditional watermen and members of the well-established hard clam aquaculture industry. In addition to growing oysters for personal consumption and marketing, an increasing number of individuals are participating in the activity to supply oysters for environmental restoration projects.
This publication represents an attempt to fulfill the need for an introduction to culturing oysters. The approach described here reflects a strategy which we have been developing and refining over the past 10 years. It is neither complete nor exclusive. It is directed towards the culture of C. virginica in areas where the common oyster diseases Dermo and MSX (caused by the pathogens Perkinsus marinus and Haplosporidium nelsoni, respectively) are endemic and it includes information for both commercial aquaculturists and non-commercial gardeners. This publication is revised from a 1997 edition and contains new information about the status of selective breeding programs, regulations in Virginia related to oyster aquaculture and non-indigenous oyster species. We have also attempted in this revision to provide a listing of more reference materials for individuals interested in further reading. As in the past, our experiences are drawn largely from work in Virginia, but the general strategy should be applicable in many locations from southern New Jersey south along the U.S. Atlantic coast
Fully Immersive Virtual Reality for Skull-base Surgery: Surgical Training and Beyond
Purpose: A virtual reality (VR) system, where surgeons can practice
procedures on virtual anatomies, is a scalable and cost-effective alternative
to cadaveric training. The fully digitized virtual surgeries can also be used
to assess the surgeon's skills using measurements that are otherwise hard to
collect in reality. Thus, we present the Fully Immersive Virtual Reality System
(FIVRS) for skull-base surgery, which combines surgical simulation software
with a high-fidelity hardware setup.
Methods: FIVRS allows surgeons to follow normal clinical workflows inside the
VR environment. FIVRS uses advanced rendering designs and drilling algorithms
for realistic bone ablation. A head-mounted display with ergonomics similar to
that of surgical microscopes is used to improve immersiveness. Extensive
multi-modal data is recorded for post-analysis, including eye gaze, motion,
force, and video of the surgery. A user-friendly interface is also designed to
ease the learning curve of using FIVRS.
Results: We present results from a user study involving surgeons with various
levels of expertise. The preliminary data recorded by FIVRS differentiates
between participants with different levels of expertise, promising future
research on automatic skill assessment. Furthermore, informal feedback from the
study participants about the system's intuitiveness and immersiveness was
positive.
Conclusion: We present FIVRS, a fully immersive VR system for skull-base
surgery. FIVRS features a realistic software simulation coupled with modern
hardware for improved realism. The system is completely open-source and
provides feature-rich data in an industry-standard format.Comment: IPCAI/IJCARS 202
VITAMIN D STATUS IN NEONATES UNDERGOING CARDIAC OPERATIONS: RELATIONSHIP TO CARDIOPULMONARY BYPASS AND OUTCOMES
Improving Surgical Situational Awareness with Signed Distance Field: A Pilot Study in Virtual Reality
The introduction of image-guided surgical navigation (IGSN) has greatly
benefited technically demanding surgical procedures by providing real-time
support and guidance to the surgeon during surgery. \hi{To develop effective
IGSN, a careful selection of the surgical information and the medium to present
this information to the surgeon is needed. However, this is not a trivial task
due to the broad array of available options.} To address this problem, we have
developed an open-source library that facilitates the development of multimodal
navigation systems in a wide range of surgical procedures relying on medical
imaging data. To provide guidance, our system calculates the minimum distance
between the surgical instrument and the anatomy and then presents this
information to the user through different mechanisms. The real-time performance
of our approach is achieved by calculating Signed Distance Fields at
initialization from segmented anatomical volumes. Using this framework, we
developed a multimodal surgical navigation system to help surgeons navigate
anatomical variability in a skull base surgery simulation environment. Three
different feedback modalities were explored: visual, auditory, and haptic. To
evaluate the proposed system, a pilot user study was conducted in which four
clinicians performed mastoidectomy procedures with and without guidance. Each
condition was assessed using objective performance and subjective workload
metrics. This pilot user study showed improvements in procedural safety without
additional time or workload. These results demonstrate our pipeline's
successful use case in the context of mastoidectomy.Comment: First two authors contributed equally. 6 page
Twin-S: A Digital Twin for Skull-base Surgery
Purpose: Digital twins are virtual interactive models of the real world,
exhibiting identical behavior and properties. In surgical applications,
computational analysis from digital twins can be used, for example, to enhance
situational awareness. Methods: We present a digital twin framework for
skull-base surgeries, named Twin-S, which can be integrated within various
image-guided interventions seamlessly. Twin-S combines high-precision optical
tracking and real-time simulation. We rely on rigorous calibration routines to
ensure that the digital twin representation precisely mimics all real-world
processes. Twin-S models and tracks the critical components of skull-base
surgery, including the surgical tool, patient anatomy, and surgical camera.
Significantly, Twin-S updates and reflects real-world drilling of the
anatomical model in frame rate. Results: We extensively evaluate the accuracy
of Twin-S, which achieves an average 1.39 mm error during the drilling process.
We further illustrate how segmentation masks derived from the continuously
updated digital twin can augment the surgical microscope view in a mixed
reality setting, where bone requiring ablation is highlighted to provide
surgeons additional situational awareness. Conclusion: We present Twin-S, a
digital twin environment for skull-base surgery. Twin-S tracks and updates the
virtual model in real-time given measurements from modern tracking
technologies. Future research on complementing optical tracking with
higher-precision vision-based approaches may further increase the accuracy of
Twin-S
A repurposing strategy for Hsp90 inhibitors demonstrates their potency against filarial nematodes
Novel drugs are required for the elimination of infections caused by filarial worms, as most commonly used drugs largely target the microfilariae or first stage larvae of these infections. Previous studies, conducted in vitro, have shown that inhibition of Hsp90 kills adult Brugia pahangi. As numerous small molecule inhibitors of Hsp90 have been developed for use in cancer chemotherapy, we tested the activity of several novel Hsp90 inhibitors in a fluorescence polarization assay and against microfilariae and adult worms of Brugia in vitro. The results from all three assays correlated reasonably well and one particular compound, NVP-AUY922, was shown to be particularly active, inhibiting Mf output from female worms at concentrations as low as 5.0 nanomolar after 6 days exposure to drug. NVP-AUY922 was also active on adult worms after a short 24 h exposure to drug. Based on these in vitro data, NVP-AUY922 was tested in vivo in a mouse model and was shown to significantly reduce the recovery of both adult worms and microfilariae. These studies provide proof of principle that the repurposing of currently available Hsp90 inhibitors may have potential for the development of novel agents with macrofilaricidal properties
Mapping interactions with the chaperone network reveals factors that protect against tau aggregation.
A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease
National audit of post-operative management in spinal surgery
BACKGROUND: There is some evidence from a Cochrane review that rehabilitation following spinal surgery may be beneficial. METHODS: We conducted a survey of current post-operative practice amongst spinal surgeons in the United Kingdom in 2002 to determine whether such interventions are being included routinely in the post-operative management of spinal patients. The survey included all surgeons who were members of either the British Association of Spinal Surgeons (BASS) or the Society for Back Pain Research. Data on the characteristics of each surgeon and his or her current pattern of practice and post-operative care were collected via a reply-paid postal questionnaire. RESULTS: Usable responses were provided by 57% of the 89 surgeons included in the survey. Most surgeons (79%) had a routine post-operative management regime, but only 35% had a written set of instructions that they gave to their patients concerning this. Over half (55%) of surgeons do not send their patients for any physiotherapy after discharge, with an average of less than two sessions of treatment organised by those that refer for physiotherapy at all. Restrictions on lifting, sitting and driving showed considerable inconsistency both between surgeons and also within the recommendations given by individual surgeons. CONCLUSION: Demonstrable inconsistencies within and between spinal surgeons in their approaches to post-operative management can be interpreted as evidence of continuing and significant uncertainty across the sub-speciality as to what does constitute best care in these areas of practice. Conducting further large, rigorous, randomised controlled trials would be the best method for obtaining definitive answers to these questions
Divergent consensuses on Arctic amplification influence on midlatitude severe winter weather
The article of record as published may be found at https://doi.org/10.1038/s41558-019-0662-yWe thank R. Blackport, C. Deser, L. Sun, J. Screen and D. Smith for discussions and
suggested revisions to the manuscript. We also thank J. Screen and L. Sun for model data.
A. Amin helped to create Fig. 2. US CLIVAR logistically and financially supported the
Arctic-Midlatitude Working Group and Arctic Change and its Influence on Mid-Latitude
Climate and Weather workshop that resulted in this article. J.C. is supported by the US
National Science Foundation grants AGS-1657748 and PLR-1504361, 1901352. M.W.
acknowledges funding by the Deutsche Forschungsgemeinschaft project no. 268020496–
TRR 172, within the Transregional Collaborative Research Center “Arctic Amplification:
Climate Relevant Atmospheric and Surface Processes, and Feedback Mechanisms (AC)3
”.
T.V. was supported by the Academy of Finland grant 317999. J.O. was supported by the
NOAA Arctic Research Program. J.F. was supported by the Woods Hole Research Center.
S.W. and H.G. are supported by the US DOE Award Number DE-SC0016605. J.Y. was
supported by the Korea Meteorological Administration Research and Development
Program under grant KMI2018-01015 and National Research Foundation grant
NRF_2017R1A2B4007480. D.H. is supported by the Helmholtz Association of German
Research Centers (grant FKZ HRSF-0036, project POLEX). The authors acknowledge the
World Climate Research Programme’s Working Group on Coupled Modelling, which is
responsible for CMIP, and thank the climate modelling groups (listed in Supplementary
Table 1) for producing and making available their model output. For CMIP, the US
Department of Energy’s PCMDI provides coordinating support and led development of
software infrastructure in partnership with the Global Organization for Earth System
Science Portals.The Arctic has warmed more than twice as fast as the global average since the late twentieth century, a phenomenon known as
Arctic amplification (AA). Recently, there have been considerable advances in understanding the physical contributions to AA,
and progress has been made in understanding the mechanisms that link it to midlatitude weather variability. Observational
studies overwhelmingly support that AA is contributing to winter continental cooling. Although some model experiments sup port the observational evidence, most modelling results show little connection between AA and severe midlatitude weather or
suggest the export of excess heating from the Arctic to lower latitudes. Divergent conclusions between model and observational
studies, and even intramodel studies, continue to obfuscate a clear understanding of how AA is influencing midlatitude weather
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