Molecular systematics of swifts of the genus Chaetura (Aves: Apodiformes: Apodidae)

Phylogenetic relationships among swifts of the morphologically conservative genus Chaetura were studied using mitochondrial and nuclear DNA sequences. Taxon sampling included all species and 21 of 30 taxa (species and subspecies) within Chaetura. Our results indicate that Chaetura is monophyletic and support the division of the genus into the two subgenera previously identified using plumage characters. However, our genetic data, when considered in combination with phenotypic data, appear to be at odds with the current classification of some species of Chaetura. We recommend that C. viridipennis, currently generally treated as specifically distinct from C. chapmani, be returned to its former status as C. chapmani viridipennis, and that C. andrei, now generally regarded as synonymous with C. vauxi aphanes, again be recognized as a valid species. Widespread Neotropical species C. spinicaudus is paraphyletic with respect to more range-restricted species C. fumosa, C. egregia, and C. martinica. Geographically structured genetic variation within some other species of Chaetura, especially notable in C. cinereiventris, suggests that future study may lead to recognition of additional species in this genus. Biogeographic analysis indicated that Chaetura originated in South America and identified several dispersal events to Middle and North America following the formation of the Isthmus of Panama

Views and uses of sepsis digital alerts in national health service trusts in England: qualitative study with health care professionals

Background: Sepsis is a common cause of serious illness and death. Sepsis management remains challenging and suboptimal. To support rapid sepsis diagnosis and treatment, screening tools have been embedded into hospital digital systems to appear as digital alerts. The implementation of digital alerts to improve the management of sepsis and deterioration is a complex intervention that has to fit with team workflow and the views and practices of hospital staff. Despite the importance of human decision-making and behavior in optimal implementation, there are limited qualitative studies that explore the views and experiences of health care professionals regarding digital alerts as sepsis or deterioration computerized clinician decision support systems (CCDSSs). Objective: This study aims to explore the views and experiences of health care professionals on the use of sepsis or deterioration CCDSSs and to identify barriers and facilitators to their implementation and use in National Health Service (NHS) hospitals. Methods: We conducted a qualitative, multisite study with unstructured observations and semistructured interviews with health care professionals from emergency departments, outreach teams, and intensive or acute units in 3 NHS hospital trusts in England. Data from both interviews and observations were analyzed together inductively using thematic analysis. Results: A total of 22 health care professionals were interviewed, and 12 observation sessions were undertaken. A total of four themes regarding digital alerts were identified: (1) support decision-making as nested in electronic health records, but never substitute professionals’ knowledge and experience; (2) remind to take action according to the context, such as the hospital unit and the job role; (3) improve the alerts and their introduction, by making them more accessible, easy to use, not intrusive, more accurate, as well as integrated across the whole health care system; and (4) contextual factors affecting views and use of alerts in the NHS trusts. Digital alerts are more optimally used in general hospital units with a lower senior decision maker:patient ratio and by health care professionals with experience of a similar technology. Better use of the alerts was associated with quality improvement initiatives and continuous sepsis training. The trusts’ features, such as the presence of a 24/7 emergency outreach team, good technological resources, and staffing and teamwork, favored a more optimal use. Conclusions: Trust implementation of sepsis or deterioration CCDSSs requires support on multiple levels and at all phases of the intervention, starting from a prego-live analysis addressing organizational needs and readiness. Advancements toward minimally disruptive and smart digital alerts as sepsis or deterioration CCDSSs, which are more accurate and specific but at the same time scalable and accessible, require policy changes and investments in multidisciplinary research

Millisecond optical phase modulation using multipass configurations with liquid-crystal devices

We present two configurations for analog 0 to 2π optical phase modulation using liquid crystals (LCs), each of which achieve switching times that are 1 ms or less. One configuration is based on the switching behavior of a so-called nematic pi cell, and the other is based on the flexoelectro-optic effect in chiral nematic LCs when operated in the uniform lying helix geometry. Both configurations exploit a multipass optical arrangement to enhance the available optical phase range, while maintaining a fast switching speed. Moreover, these devices can be operated at or close to room temperature. Experimental data are found to be in good agreement with results predicted from theory for these multipass phase-modulation configurations

Carotenoid-based skin ornaments reflect foraging propensity in a seabird, Sula leucogaster

Carotenoid-based ornaments are common signalling features in animals. It has long been proposed that such ornaments communicate information about foraging abilities to potential mates. However, evidence linking foraging with ornamentation is largely missing from unmanipulated, free-ranging populations. To investigate this relationship, we studied a coastal population of brown booby (Sula leucogaster brewsteri), a seabird with a carotenoid-based gular skin ornament. δ13C values from both feathers and blood plasma were negatively correlated with male gular colour, indicating birds that consumed more pelagic prey in offshore locations had more ornamented skin than those that fed on nearshore, benthic prey. This relationship was supported by our GPS tracking results, which revealed longer, more offshore foraging trips among highly ornamented males. Our data show that brown booby ornaments are honest indicators of foraging propensity; a link consistent with the rarity hypothesis and potentially driven by the concentration of carotenoids found in phytoplankton versus benthic algae. Carotenoid-based ornaments may reflect foraging tendencies in animals such as coastal predators that use food webs with distinct carotenoid profiles

Nonlinear optics via double dark resonances

Double dark resonances originate from a coherent perturbation of a system displaying electromagnetically induced transparency. We experimentally show and theoretically confirm that this leads to the possibility of extremely sharp resonances prevailing even in the presence of considerable Doppler broadening. A gas of 87Rb atoms is subjected to a strong drive laser and a weak probe laser and a radio frequency field, where the magnetic coupling between the Zeeman levels leads to nonlinear generation of a comb of sidebands.Comment: 6 pages, 9 figure

Flexoelectro-optic liquid crystal analog phase-only modulator with a 2π range and 1 kHz switching

We present a flexoelectro-optic liquid crystal (LC) analog phase modulator with >

Muscle Loss: The New Malnutrition Challenge in Clinical Practice

Recent definitions of malnutrition include low muscle mass within its diagnostic criteria. In fact, malnutrition is one of the main risk factors of skeletal muscle loss contributing to the onset of sarcopenia. However, differences in the screening and diagnosis of skeletal muscle loss, especially as a result of malnutrition in clinical and community settings, still occur mainly as techniques and thresholds used vary in clinical practice. The objectives of this position paper are firstly to emphasize the link between skeletal muscle loss and malnutrition-related conditions and secondly to raise awareness for the timely identification of loss of skeletal muscle mass and function in high risk populations. Thirdly to recognize the need to implement appropriate nutritional strategies for prevention and treatment of skeletal muscle loss and malnutrition across the healthcare continuum. Malnutrition needs to be addressed clinically as a muscle-related disorder and clinicians should integrate nutritional assessment with muscle mass measurements for optimal evaluation of these two interrelated entities to tailor interventions appropriately. The design of monitoring/evaluation and discharge plans need to include multimodal interventions with nutrition and physical exercise that are key to preserve patient’s muscle mass and function in clinical and community settings

Fast and low loss flexoelectro-optic liquid crystal phase modulator with a chiral nematic reflector

© 2019, The Author(s). In this paper, we demonstrate a flexoelectro-optic liquid crystal phase-only device that uses a chiral nematic reflector to achieve full 2π phase modulation. This configuration is found to be very tolerant to imperfections in the chiral nematic reflector provided that the flexoelectro-optic LC layer fulfils the half-wave condition. Encouragingly, the modulation in the phase, which operates at kHz frame rates, is also accompanied by low amplitude modulation. The configuration demonstrated herein is particularly promising for the development of next-generation liquid crystal on silicon spatial light modulators

Fast and low loss flexoelectro-optic liquid crystal phase modulator with a chiral nematic reflector

© 2019, The Author(s). In this paper, we demonstrate a flexoelectro-optic liquid crystal phase-only device that uses a chiral nematic reflector to achieve full 2π phase modulation. This configuration is found to be very tolerant to imperfections in the chiral nematic reflector provided that the flexoelectro-optic LC layer fulfils the half-wave condition. Encouragingly, the modulation in the phase, which operates at kHz frame rates, is also accompanied by low amplitude modulation. The configuration demonstrated herein is particularly promising for the development of next-generation liquid crystal on silicon spatial light modulators