Mars thermosphere as seen in MAVEN accelerometer data Zurek, R. W.; Tolson, R. A.; Bougher, S. W. ...
Journal of geophysical research. Space physics,
March 2017, 2017-03-00, 20170301, Letnik:
122, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The Mars thermosphere (above approximately 120 km) has been probed in situ for one Mars year using accelerometers on board the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. This region ...is affected by radiation and energy deposition from the Sun and by energy and momentum from the lower atmosphere. Densities derived from measurements made during the nominal science orbits (periapsis > 140 km) show consistent trends with solar zenith angle and Sun‐Mars distance, reflecting direct and indirect heating of the thermosphere, although orbit‐to‐orbit variability is still significant. The six Deep Dip campaigns that MAVEN has conducted (with periapsis dropping below ~135 km) significantly extend the vertical profiles of the densities derived from accelerometer data. These show complex structure and high variability, both dependent on season, local time, location, and lower atmosphere activity, including dust storms and wave propagation from a dynamic lower atmosphere. In particular, the terminators are a region of convoluted structure and high variability, which may be greatest in the postmidnight, predawn hours of the sol. This space‐time regime was not sampled by previous orbiters at Mars. While initial comparisons with thermospheric general circulation modes show broad areas of agreement, these terminator transition regions are not simulated well by current models. Judicious choice of the timing of these Deep Dip campaigns during the remaining MAVEN mission, as periapsis continues to precess through local time, latitude, and longitude in both hemispheres and in different seasons, should help clarify the processes at work in this complicated region.
Key Points
MAVEN accelerometer data fill major gaps in space‐time coverage of Mars in situ measurements of thermospheric bulk densities
Comparisons with models revealed the largest differences in the lower thermosphere (120‐160 km) near the terminators, especially predawn
Density variations are largest at the lowest (and coldest) altitudes, above the equator at midnight, and over the predawn midlatitudes
In this article, I present a firsthand account as an anaesthetist with substance use disorder who has been through rehabilitation and returned to clinical anaesthesia, followed by an overview of ...substance use disorder in anaesthesia. Substance use disorder is prevalent within the anaesthesia community and can result in tragic consequences, including death in many cases. The incidence is around one to two per 1000 anaesthetist years and this appears to be rising, perhaps mirroring the population-wide increase in substance use disorder as a result of the opioid epidemic. Recognising substance use disorder in a colleague and intervening to try and help them and protect patients can be immensely challenging. Carrying out a successful intervention requires careful planning and coordination in order to protect the affected individual, their colleagues and patients. Returning to clinical anaesthesia following a diagnosis of substance use disorder is also contentious, with the high abstinence rate (relative to the wider substance use disorder population) having to be balanced against the risk of death following relapse. Any return to practice must be well planned and supported, and include appropriate toxicology screening. With such measures, rehabilitation and a return to clinical anaesthesia is possible in certain cases. For the affected individual regaining, then maintaining, their professional identity can be a powerful motivator to remain abstinent. Drug diversion and substance use disorder in anaesthesia is unlikely ever to be fully preventable, but strategies such as biometric dispensing, analysis of unused drugs, random toxicology and ongoing education may help to keep it to a minimum.
Mass stranding events (MSEs) of beaked whales (BWs) were extremely rare prior to the 1960s but increased markedly after the development of naval mid-frequency active sonar (MFAS). The temporal and ...spatial associations between atypical BW MSEs and naval exercises were first observed in the Canary Islands, Spain, in the mid-1980s. Further research on BWs stranded in association with naval exercises demonstrated pathological findings consistent with decompression sickness (DCS). A 2004 ban on MFASs around the Canary Islands successfully prevented additional BW MSEs in the region, but atypical MSEs have continued in other places of the world, especially in the Mediterranean Sea, with examined individuals showing DCS. A workshop held in Fuerteventura, Canary Islands, in September 2017 reviewed current knowledge on BW atypical MSEs associated with MFAS. Our review suggests that the effects of MFAS on BWs vary among individuals or populations, and predisposing factors may contribute to individual outcomes. Spatial management specific to BW habitat, such as the MFAS ban in the Canary Islands, has proven to be an effective mitigation tool and mitigation measures should be established in other areas taking into consideration known population-level information.
Background/Aims: There is emerging evidence of gabapentin and pregabalin (gabapentinoid) abuse, particularly in the substance misuse population, and some suggestion of gabapentinoids being abused ...alongside methadone. Methods: A questionnaire-based survey was carried out in six substance misuse clinics, looking for evidence of gabapentinoid abuse. Results: 22% (29/129) of respondents admitted to abusing gabapentinoids, and of these, 38% (11/29) abused gabapentinoids in order to potentiate the ‘high' they obtained from methadone. Conclusions: Gabapentinoid abuse along with methadone has not previously been described. These findings are of relevance to clinicians working within both substance misuse services and chronic pain services.
To characterize national trends in and associated outcomes of more often than annual prostate-specific antigen (PSA) screening, which we term “prosteria.”
Men in the Optum Clinformatics Data Mart ...with ≥2 years from first PSA test to censoring at the end of insurance or available data (January 2003 to June 2019) or following exclusionary diagnoses or procedures, such as PCa treatment, were included. PSAs within 90 days were treated as one PSA. Prosteria was defined as having ≥3 PSA testing intervals of ≤270 days.
A total of 9,734,077 PSAs on 2,958,923 men were included. The average inter-PSA testing interval was 1.5 years, and 4.5% of men had prosteria, which increased by 0.53% per year. Educated, wealthy, non-White patients were more likely to have prosteria. Men within the recommended screening age (ie 55-69) had lower rates of prosteria. Prosteria patients had higher average PSA values (2.5 vs 1.4 ng/mL), but lower values at PCa diagnosis. Prosteria was associated with biopsy and PCa diagnosis; however, there were comparable rates of treatment within 2 years of diagnosis.
In this large cohort study, prosteria was common, increased over time, and was associated with demographic characteristics. Importantly, there were no clinically meaningful differences in PSA values at diagnosis or rates of early treatment, suggesting prosteria leads to both overdiagnosis and overtreatment. These results support current AUA and USPTF guidelines and can be used to counsel men seeking more frequent PSA screening.
Delivery of information to clinicians on evolving antimicrobial susceptibility needs to be accurate for the local needs, up-to-date and readily available at point of care. In northern Australia, ...bacterial infection rates are high but resistance to first- and second-line antibiotics is poorly described and currently-available datasets exclude primary healthcare data. We aimed to develop an online geospatial and interactive platform for aggregating, analysing and disseminating data on regional bacterial pathogen susceptibility. We report the epidemiology of Staphylococcus aureus as an example of the power of digital platforms to tackle the growing spread of antimicrobial resistance in a high-burden, geographically-sparse region and beyond. We developed an online geospatial platform called HOTspots that visualises antimicrobial susceptibility patterns and temporal trends. Data on clinically-important bacteria and their antibiotic susceptibility profiles were sought from retrospectively identified clinical specimens submitted to three participating pathology providers (96 unique tertiary and primary healthcare centres, n = 1,006,238 tests) between January 2008 and December 2017. Here we present data on S. aureus only. Data were available on specimen type, date and location of collection. Regions from the Australian Bureau of Statistics were used to provide spatial localisation. The online platform provides an engaging visual representation of spatial heterogeneity, demonstrating striking geographical variation in S. aureus susceptibility across northern Australia. Methicillin resistance rates vary from 46% in the west to 26% in the east. Plots generated by the platform show temporal trends in proportions of S. aureus resistant to methicillin and other antimicrobials across the three jurisdictions of northern Australia. A quarter of all, and up to 35% of methicillin-resistant S. aureus (MRSA) blood isolates in parts of the northern Australia were resistant to inducible-clindamycin. Clindamycin resistance rates in MRSA are worryingly high in regions of northern Australia and are a local impediment to empirical use of this agent for community MRSA. Visualising routinely collected laboratory data with digital platforms, allows clinicians, public health physicians and guideline developers to monitor and respond to antimicrobial resistance in a timely manner. Deployment of this platform into clinical practice supports national and global efforts to innovate traditional disease surveillance systems with the use of digital technology and to provide practical solutions to reducing the threat of antimicrobial resistance.
The presence of distinct social groups within an animal population can result in heterogeneity in many aspects of its life history and ecology. The ability to accurately assess social group ...membership increases with the number of times individuals are identified, but obtaining sufficient sightings of rarely encountered species can be difficult. Three social clusters were previously identified for the endangered population of false killer whales
Pseudorca crassidens
around the main Hawaiian Islands, using modularity among associations within a 12 yr photographic dataset with no restrictions on the number of times seen. In this study, we used photo-identification data over a 23 yr period to reassess the number and membership of social clusters, restricted to individuals seen on at least 5 different days. We compared the robustness of clustering assignments from 6 community detection algorithms using modularity and found that the 3 highest-ranking algorithms all identified the same number (4) and membership of social clusters. Spatial use of clusters varied among the islands, with 3 of the 4 clusters encountered regularly only off 1 or 2 of the 3 main island study areas. Comparison of genetic differentiation among social clusters revealed significant differentiation in nuclear DNA. Furthermore, all individuals in 2 of the clusters possess the same mitochondrial DNA haplotype, while in the other 2 clusters, approximately 40% of animals possess a second haplotype. This level of clustering and associated heterogeneity within the population may have implications for mark-recapture abundance estimation, as well as for mitigating exposure to anthropogenic activities, including interactions with fisheries.HŌ‘ULU‘ULU MANA‘O: Pili nā ‘ano like ‘ole o ka nohona a me ke kālaikaiaola o nā pū‘uo holoholona i ka loa‘a ‘ana o nā pū‘ulu kiko‘ī. Pi‘i a‘e ka hiki ke helu kūpono‘ia ka māhuahua ‘ana o nā heluna o ia mau pū‘ulu i ka helu ‘ana i nā wā e ‘ike ‘ia ai kēlā me kēia holoholona, ‘o ka lawa ‘ana na‘e o ka ‘ike ‘ana i nā lāhulu ‘ane halapohe kekahi ālaina. Hō‘ia ‘ia ‘ekolu pū‘ulu o ke koholā ‘ane halapohe, ‘o ka
Pseudorca crassidens
, a puni nā mokupuni nui ‘ewalu o Hawai‘i, ma ka ho‘owae‘anona ‘ana i ka pilina i loko o kekahi ‘ikepili ki‘a he ‘umikūmālua makahiki me ke kāohi ‘ole i ka nui o ka ‘ike ‘ia ‘ana. Ma kēia kilo ‘ana, ua ho‘ohana mākou i ka ‘ikepili ma o nā makahiki he iwakāluakūmākolu i mea e hō‘oia hou ai i ka heluna a me nā lālā o nā pū‘ulu launa i loko o kekahi pū‘uo holoholona, a pāpā ‘ia nā kālailaina i nā mea i ‘ike ‘ia ma ‘elima mau lā ‘oko‘a ma ka li‘ili‘i loa. Ho‘ohālikelike mākou i ke ‘ano me ka ikaika o kēia mau pū‘ulu launa ma ka ho‘ohana ‘ana i ka ho‘owae‘anona ‘ana ma ‘eono pū‘ulu ha‘ilula a ‘o ka mea i loa‘a, ‘o ia ho‘i ka ‘ike ‘ana, ma o nā ha‘ilula nui ‘ekolu, i ka heluna a me ka lālā ho‘okahi o nā pū‘ulu launa. Loli ka ho‘ohana ‘ana i ke koana o nā pū‘ulu ma waena o nā mokupuni, ‘ike ‘ia ‘ekolu pū‘ulu ma ho‘okahi a ‘elua paha mokupuni mai loko mai o nā mokupuni nui ‘ekolu e kālailai ‘ia ana. Ma ka ho‘ohālikelike ‘ana aku i nā hi‘ohi‘ona ōewe ‘oko‘a o nā pū‘ulu launa, ‘ike ‘ia ka ‘oko‘a ‘ano nui ma ka piko ōewe o nā pū‘ulu. A no laila, loa‘a i nā mea a pau o ia mau pū‘ulu ‘elua ke ōewe ho‘oilina ho‘okahi, a ma nā pū‘ulu ‘ē a‘e ‘elua, loa‘a he hi‘ohi‘ona ōewe ‘elua i nā holoholona he 40 pākēneka. Hiki nō paha i kēia ‘ano ho‘opū‘ulu ‘ana me kēia ‘ano wae‘anona ōewe ho‘opili ma kekahi pū‘uo ke pili i ke kuhi ‘ana i ka nui ma ka hopu kaha ‘ana, a i ke kāohi a ho‘ēmi ‘ana mai i nā hopena o nā hana kanaka, e la‘a ho‘i me ka hana ma ke kai lawai‘a.
Species conservation relies on understanding population demographics, yet this information is lacking for many species and populations. Four stocks of common bottlenose dolphins
Tursiops truncatus
...inhabiting the waters surrounding the main Hawaiian Islands (USA) are exposed to anthropogenic disturbances including fisheries interactions, tourism, naval activities, ocean noise, and contaminants. Although these stocks are managed under the Marine Mammal Protection Act, a demographic assessment has not been undertaken since 2006, and there is currently no information on population trends. We combined regular survey effort with citizen science contributions to estimate apparent survival and annual abundance within each stock using photographs collected between 2000 and 2018. Over this time period, we collected 2818 high-quality identifications of 765 distinctive individuals across all 4 stocks. Analyses of inter-annual movements indicated that individuals exhibit restricted habitat use within stocks, which contributed to non-random sampling. Annual abundance estimates ranged from the 10s to the low 100s. Apparent survival ranged from 0.84 to 0.9, with lower-than-expected estimates in all stocks. Annual abundance estimates declined in 3 of the 4 stocks; however, this decline was not significant for the Kaua‘i/Ni‘ihau and O‘ahu stocks, and may be an artifact of sampling design in all stocks. Given the small population size for these stocks, it is important to closely monitor trends in abundance as a first step in mitigating negative effects of anthropogenic activities. Future efforts should focus on consistent geographic coverage in all stocks to decrease model uncertainty and improve trend assessment.
The human endometrium displays characteristic features, both structural and functional, across the menstrual cycle. It is the sex steroid hormones, oestrogen and progesterone, that drive the ...endometrium through the different phases of the cycle. Oestrogen and progesterone act sequentially to regulate cellular concentrations of their respective receptors, this interaction initiates gene transcription. Thereafter a cascade of local events prepares the endometrium for implantation, but in the absence of pregnancy, progesterone withdrawal leads to menstruation and cyclic repair. Withdrawal of progesterone from an oestrogen-progesterone primed endometrium is the initiating event for the cascade of molecular and cellular interactions that result in menstruation. Progesterone withdrawal first affects cells with progesterone receptors. Early events in the menstrual process are vasoconstriction and cytokine up-regulation. The activation of lytic mechanisms is a later event and involves cells that may lack progesterone receptors, for example, uterine leucocytes and epithelial cells. Hence progesterone withdrawal results in a local increase of inflammatory mediators and the enzymes responsible for tissue breakdown. The total complex of local factors implicated in normal menstrual and aberrant menstrual bleeding are yet to be fully defined.
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