781 research outputs found

    First Recorded Mating Flight of the Hypogeic Ant, Acropyga epedana, with its Obligate Mutualist Mealybug, Rhizoecus colombiensis

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    On 26-July, 2005 a mating aggregation of Acropyga epedana Snelling (Hymenoptera: Formicidae) was observed in the Chiricahua Mountains in south-eastern Arizona. This is the first record of a mating flight of A. epedana, the only nearctic member of this pantropical genus. Mating behavior was observed, newly mated queens were collected, and a complete colony was excavated. New information is reported on the natural history and mating behavior of the species. The identity of a mealybug mutualist, Rhizoecus colombiensis (Homoptera: Rhizoecinae) is confirmed. Reproductive females participating in flights all carried mealybugs between their mandibles, indicating a vertical transfer of mealybugs with their ant hosts. No captured foundresses survived long in captivity, most likely due to the death of their mealybugs. The colony excavated had a single queen, though polygyny is common in the genus. Nearly all workers within the nest were heavily parasitized by mites, although males or gynes were not parasitized. These natural history observations are discussed with regard to this poorly understood mutualistic relationship between Acropyga ants and their mealybug partners

    First-in-man craniectomy and asportation of solitary cerebellar metastasis in COVID-19 patient: A case report

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    Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has an impact on the delivery of neurosurgical care, and it is changing the perioperative practice worldwide. We present the first case in the literature of craniectomy procedure and asportation of a solitary cerebellar metastasis of the oesophagus squamous carcinoma in a 77 years old woman COVID-19 positive. In these particular circumstances, we show that adequate healthcare resources and risk assessments are essential in the management of COVID-19 patients referred to emergency surgery. Presentation of case: The case here presented was treated in 2019 for squamous carcinoma of the oesophagus. In April 2020, she presented a deterioration of her clinical picture consisting of dysphagia, abdominal pain, hyposthenia and ataxia. A Head CT scan was performed, which showed the presence of a solitary cerebellar metastasis. Her associated SARS-CoV-2 positivity status represented the principal clinical concern throughout her hospitalisation. Discussion: The patient underwent a suboccipital craniectomy procedure with metastasis asportation. She tested positive for SARS-CoV-2 in the pre- and post-operative phases, but she was not admitted to the intensive care unit because she did not present any respiratory complications. Her vital parameters and inflammation indexes fell within the reference ranges, and she was kept in isolation for 16 days in our neurosurgical unit following strict COVID-19 measures. She was asymptomatic and not treated for any of the specific and non-specific symptoms of COVID-19. Conclusion: This is the first case reported of solitary cerebellar metastasis of oesophagus carcinoma operated on a COVID-19 positive patient. It shows that asymptomatic COVID-19 positive patients can undergo major emergency surgeries without the risk of infecting the operating team if adequate Personal Protection Equipment (PPE) is used. The patient remained asymptomatic and did not develop the disease's active phase despite undergoing a stressful event such as a major emergency neurosurgical procedure. In the current crisis, a prophylactic COVID-19 screening test can identify asymptomatic patients undergoing major emergency surgery and adequate resource planning and Personal Protective Equipment (PPE) for healthcare workers can minimise the effect of the COVID-19 pandemic

    The Formal Dynamism of Categories: Stops vs. Fricatives, Primitivity vs. Simplicity

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    Minimalist Phonology (MP; Pöchtrager 2006) constructs its theory based on the phonological epistemological principle (Kaye 2001) and exposes the arbitrary nature of standard Government Phonology (sGP) and strict-CV (sCV), particularly with reference to their confusion of melody and structure. For Pöchtrager, these are crucially different, concluding that place of articulation is melodic (expressed with elements), while manner of articulation is structural. In this model, the heads (xN and xO) can license and incorporate the length of the other into their own interpretation, that is xN influences xO projections as well as its own and vice versa. This dynamism is an aspect of the whole framework and this paper in particular will show that stops and fricatives evidence a plasticity of category and that, although fricatives are simpler in structure, stops are the more primitive of the two. This will be achieved phonologically through simply unifying the environment of application of the licensing forces within Pöchtrager's otherwise sound onset structure. In doing so, we automatically make several predictions about language acquisition and typology and show how lenition in Qiang (Sino-Tibetan) can be more elegantly explained

    Dynamic validation of the Planck/LFI thermal model

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    The Low Frequency Instrument (LFI) is an array of cryogenically cooled radiometers on board the Planck satellite, designed to measure the temperature and polarization anisotropies of the cosmic microwave backgrond (CMB) at 30, 44 and 70 GHz. The thermal requirements of the LFI, and in particular the stringent limits to acceptable thermal fluctuations in the 20 K focal plane, are a critical element to achieve the instrument scientific performance. Thermal tests were carried out as part of the on-ground calibration campaign at various stages of instrument integration. In this paper we describe the results and analysis of the tests on the LFI flight model (FM) performed at Thales Laboratories in Milan (Italy) during 2006, with the purpose of experimentally sampling the thermal transfer functions and consequently validating the numerical thermal model describing the dynamic response of the LFI focal plane. This model has been used extensively to assess the ability of LFI to achieve its scientific goals: its validation is therefore extremely important in the context of the Planck mission. Our analysis shows that the measured thermal properties of the instrument show a thermal damping level better than predicted, therefore further reducing the expected systematic effect induced in the LFI maps. We then propose an explanation of the increased damping in terms of non-ideal thermal contacts.Comment: Planck LFI technical papers published by JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/1748-022

    Associations Between Features of Glucose Exposure and A1C: The A1C-Derived Average Glucose (ADAG) Study

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    OBJECTIVE: Various methods are used to quantify postprandial glycemia or glucose variability, but few have been compared and none are standardized. Our objective was to examine the relationship among common indexes of postprandial glycemia, overall hyperglycemia, glucose variability, and A1C using detailed glucose measures obtained during everyday life and to study which blood glucose values of the day provide the strongest prediction of A1C. RESEARCH DESIGN AND METHODS: In the A1C-Derived Average Glucose (ADAG) study, glucose levels were monitored in 507 participants (268 type 1 diabetic, 159 type 2 diabetic, and 80 nondiabetic subjects) with continuous glucose monitoring (CGM) and frequent self-monitoring of blood glucose (SMBG) during 16 weeks. We calculated several indexes of glycemia and analyzed their intercorrelations. The association between glucose measurements at different times of the day (pre- and postprandial) and A1C was examined using multiple linear regression. RESULTS: Indexes of glucose variability showed strong intercorrelation. Among postprandial indexes, the area under the glucose curve calculated from CGM 2 h after a meal correlated well with the 90-min SMBG postprandial measurements. Fasting blood glucose (FBG) levels were only moderately correlated with indexes of hyperglycemia and average or postprandial glucose levels. Indexes derived with SMBG strongly correlated with those from CGM. Some SMBG time points had a stronger association with A1C than others. Overall, preprandial glucose values had a stronger association with A1C than postprandial values for both diabetes types, particularly for type 2 diabetes. CONCLUSIONS: Indexes of glucose variability and average and postprandial glycemia intercorrelate strongly within each category. Variability indexes are weakly correlated with the other categories, indicating that these measures convey different information. FBG is not a clear indicator of general glycemia. Preprandial glucose values have a larger impact on A1C levels than postprandial values

    Thermal susceptibility of the Planck-LFI receivers

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    This paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst . This paper describes the impact of the Planck Low Frequency Instrument front end physical temperature fluctuations on the output signal. The origin of thermal instabilities in the instrument are discussed, and an analytical model of their propagation and impact on the receivers signal is described. The experimental test setup dedicated to evaluate these effects during the instrument ground calibration is reported together with data analysis methods. Finally, main results obtained are discussed and compared to the requirements.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Journal of Instrumentation. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at 10.1088/1748-0221/4/12/T1201

    Palliative surgery or metallic stent positioning for advanced gastric cancer: differences in QOL

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    Background and Objectives: Twenty percent of the patients affected with stage IV antropyloric stomach cancer are hospitalized with a gastric outlet obstruction syndrome (GOOS) requiring its resolution to improve the quality of life (QoL).We present our preliminary short- and mid-term results regarding the influence of endoscopic placement of self-expandable metal stent (SEMS) or open stomach-partitioning gastrojejunostomy in QoL. Materials and Methods: In this prospective randomized longitudinal cohort trial, we randomly assigned 27 patients affected with stage IV antropyloric stomach cancer into two groups: Group 1 (13 patients) who underwent SEMS positioning and Group 2 (14 patients) in whom open stomach-partitioning gastrojejunostomy was performed. The Karnofsky performance scale and QoL assessment using the EQ-5D-5L™ questionnaire was administered before treatment and thereafter at 1, 3, and 6 months. Results: At 1-month, index values showed a statistically significant deterioration of the QoL in patients of Group 2 when compared to those of Group 1 (p = 0.004; CI: 0.04 to 0.21). No differences among the groups were recorded at 3-month; whereas, at 6-month, the index values showed a statistically significant deterioration of the QoL in patients of Group 1 (p = 0.009; CI: -0.25 to -0.043). Conclusions: Early QoL of patients affected with stage IV antropyloric cancer and symptoms of GOOS is significantly better in patients treated with SEMS positioning but at 6-month the QoL significantly decrease in this group of patients. We explained the reasons of this fluctuation with the higher risk of re-hospital admission in the SEMS group

    Planck-LFI radiometers tuning

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    "This paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst" This paper describes the Planck Low Frequency Instrument tuning activities performed through the ground test campaigns, from Unit to Satellite Levels. Tuning is key to achieve the best possible instrument performance and tuning parameters strongly depend on thermal and electrical conditions. For this reason tuning has been repeated several times during ground tests and it has been repeated in flight before starting nominal operations. The paper discusses the tuning philosophy, the activities and the obtained results, highlighting developments and changes occurred during test campaigns. The paper concludes with an overview of tuning performed during the satellite cryogenic test campaign (Summer 2008) and of the plans for the just started in-flight calibration.Comment: This is an author-created, un-copyedited version of an article accepted for publication in JINST. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at http://dx.doi.org/10.1088/1748-0221/4/12/T12013
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