1,196 research outputs found

    InAs-AlSb quantum wells in tilted magnetic fields

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    InAs-AlSb quantum wells are investigated by transport experiments in magnetic fields tilted with respect to the sample normal. Using the coincidence method we find for magnetic fields up to 28 T that the spin splitting can be as large as 5 times the Landau splitting. We find a value of the g-factor of about 13. For small even-integer filling factors the corresponding minima in the Shubnikov-de Haas oscillations cannot be tuned into maxima for arbitrary tilt angles. This indicates the anti-crossing of neighboring Landau and spin levels. Furthermore we find for particular tilt angles a crossover from even-integer dominated Shubnikov-de Haas minima to odd-integer minima as a function of magnetic field

    Impact of paddy straw mulch on germination and growth of celery (Apium graveolens L.) seedlings and associated weeds in nursery

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    A study was undertaken during three consecutive rabi seasons of 2014–15 to 2016–17 at the Research Farm, Department of Agronomy, Punjab Agricultural University, Ludhiana (Punjab) to determine the effect of paddy straw mulch load and retention time on the germination and growth of celery and associated weeds. The experiment was conducted in randomized complete block design (RCBD) with nine treatments viz., paddy straw mulch @ 4 and 6 t ha-1 with retention time of 15, 20, 25 days after sowing (DAS), full time retention (60 DAS), and control (without mulch). The results indicated that application of paddy straw mulch @ 4 or 6 t ha-1 significantly improved the germination of celery in nursery as compared to no mulch treatment but retention of paddy straw mulch beyond 20 days after sowing suppressed the celery seedlings adversely resulting in lowering seedling population as well as fresh and dry weight of celery seedlings. Application of paddy straw mulch @ 4 or 6 t ha-1 resulted in significantly lower density and dry weight of weeds as compared to control. Further, each successive increase in retention time of paddy straw mulch from 15 DAS to full time retention (60 DAS) through 20 and 25 DAS significantly reduced the weed population in celery nursery

    Meiosis I chromosome segregation is established through regulation of microtubule–kinetochore interactions

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    During meiosis, a single round of DNA replication is followed by two consecutive rounds of nuclear divisions called meiosis I and meiosis II. In meiosis I, homologous chromosomes segregate, while sister chromatids remain together. Determining how this unusual chromosome segregation behavior is established is central to understanding germ cell development. Here we show that preventing microtubule–kinetochore interactions during premeiotic S phase and prophase I is essential for establishing the meiosis I chromosome segregation pattern. Premature interactions of kinetochores with microtubules transform meiosis I into a mitosis-like division by disrupting two key meiosis I events: coorientation of sister kinetochores and protection of centromeric cohesin removal from chromosomes. Furthermore we find that restricting outer kinetochore assembly contributes to preventing premature engagement of microtubules with kinetochores. We propose that inhibition of microtubule–kinetochore interactions during premeiotic S phase and prophase I is central to establishing the unique meiosis I chromosome segregation pattern.Howard Hughes Medical InstituteNational Institutes of Health (U.S.) (grant GM62207)Jane Coffin Childs Memorial Fund for Medical ResearchAmerican Cancer Societ

    Spontaneous expulsion of a large infarcted endometrial polyp

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    A 30-year-female presented to gynaecology OPD with history of polymenorrhea for two months.  Cervical scrape smear was negative for intraepithelial lesion/malignancy. The importance of sending the tissue for histopathological examination cannot be undermined considering the fact that the differential diagnosis includes malignancy

    Social change and marriage patterns in the North Western Himalayas (i.e. Churaha, Pangi and Ladakh).

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    I have suggested here a new approach based on power relations for understanding the social organisation in North India in general and in the North Western Himalayas in particular. The importance of marriage in defining the social structure is generally well recognised. But its direct involvement with power relations and widely different implications of this involvement for dominant and dependant sections of the population has not been explored so far. Marriage norms (for instance hypergamy) in a dominant section of the population or in a more developed area have the capacity to create exactly opposite norms elsewhere. Particular changes provide only dramatic illustrations of this phenomenon. What is normally referred to as traditional social organisation is far from being static or uniform. It is inherently dynamic and closely follows the changes in power relations. I have made it clear by working along three dimensions namely spatial, hierarchical and temporal. This approach has given me a. new way of looking at particular problems concerning stratification and social mobility, co existence of widely different forms of marriage, marriage stability, kinship relations, position of women etc. In explaining the differences in particular values and practices in different areas, this approach is directly opposed to that of a culturologist who tends to stress the lack of interaction instead

    Increasing Incidence of MDROs: An Emerging Global Concern

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    Introduction: With massive efflux of civilians from violence-stricken countries, the high rates of colonization with multidrug-resistant organisms (MDROs) amongst the refugees is an emerging global concern. Our report describes two Middle Eastern patients who suffered severe traumatic injuries in their home countries, subsequently developing chronic wounds. Upon arrival to the United States, the patients sought treatment in our institution for wound infection with MDRO. Materials and methods: Clinical data was collected from the patients’ charts. Identification and susceptibility testing were performed as part of routine identification/susceptibility test in the clinical microbiology laboratory. MICs performed by manual microbroth dilution according to Clinical and Laboratory Standards Institute (CLSI) guidelines.Time kill curves used to determine in vitro synergy of Pseudomonas aeruginosa isolate in various antibiotic combinations (½ x MIC meropenem plus ½ x MIC colistin, ½ x MIC meropenum plus ½ x MIC colistin plus ½ x MIC rifampin and ½ x MIC meropenem plus ½ x MIC ceftazidime/avibactam). Mueller Hinton II broth was used. Samples were serially diluted at 0, 4 and 24 hours and plated on TSA II agar. Time kill curves were constructed, plotting colony counts over time, with synergy being defined as ≥2-log10 decrease in CFU/ml between the combination and its most active constituent after 24h, the number of surviving organisms in the presence of combination must be ≥2 log10 CFU/ml below the starting inoculum. Results: Patient 1 came from Syria, and patient 2 from Yemen. Both patients’ wound infections were healthcare-associated, with underlying chronic osteomyelitis. Both had multiple risk factors for MDRO, including multiple prior surgeries and antibiotic courses. Patient 1 culture grew CRE Klebsiella and MDR Morganella, and later ESBL Escherichia coli. Patient 2 culture grew Pseudomonas aeruginosa sensitive only to colistin. Patient 1 was treated with ertapenem. Patient 2 received rifampin+meropenen+colistin, the only antibiotic combination demonstrating synergistic killing. Both patients required prolonged therapy, and on follow up were doing well. Conclusions: Colonization with MDRO amongst Middle Eastern immigrants is an alarming phenomenon.In vitro experiments with available antibacterial agents may assist in the choice of therapy for MDRO strains when conventional options are exhausted.https://scholarlycommons.henryford.com/merf2019basicsci/1001/thumbnail.jp

    COVID-19 Presenting with Neurological Symptoms

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    Introduction: Healthcare officials of Wuhan City in China became aware of several pneumonia cases with an unknown etiology in December 2019. A novel coronavirus, SARS-CoV-2, was identified as cause of the disease named Coronavirus disease-19 (COVID-19). SARS-CoV-2 enters cells through a receptor found on pneumocytes, and there is also evidence this receptor is located on neurons and glial cells. Recently, the neurological manifestations of COVID-19 have been described. However, to our knowledge, there are currently no known cases of COVID-19 presenting as cerebellar dysfunction and essential tremor, which we describe here. Case: A 77-year-old obese man with a past medical history of hypertension and essential tremor presented with decreased mentation, episodes of blank staring, bradykinesia, and worsening bilateral hand tremors. He also reported shortness of breath with a cough productive of clear sputum. Physical exam was within normal limits except for tachypnea requiring 4 liters of oxygen, a bilateral essential tremor and dysmetria. All labs were within normal limits. A chest x-ray suggested multifocal pneumonia. A Computed Tomography (CT) scan demonstrated scattered ground glass opacities and multi-lobar pneumonia, while a CT scan of the head was negative. Treatment was initiated for community acquired pneumonia with azithromycin and ceftriaxone. Upon admission, the patient continued to be orientated only to person and place. Subsequent laboratory investigation demonstrated elevated ferritin (1,200 ng/mL), Lactate Dehydrogenase (613 IU/L), C-Reactive Protein (13.2 mg/dL), and low procalcitonin ( Discussion: The respiratory systems – cough, sputum production, and dyspnea – and imaging findings of COVID-19 are well described.7–11 The presented case is unique because, while the patient did display the established symptoms of COVID-19, he also had encephalopathy, bilateral essential tremor, and cerebellar dysfunction. Neurological imaging was negative, and patients with these symptoms would traditionally receive further investigation. Patients with neurological dysfunction secondary to COVID-19 can demonstrate some significant findings on magnetic resonance imaging (MRI) such as enhancement in the leptomeningeal region and bilateral frontotemporal hypoperfusion on perfusion imaging.5However, because of his concomitant respiratory symptoms, and in context of the ongoing COVID-19 pandemic, our patient did not receive further neurological imaging as there was a high index of suspicion. The central and peripheral nervous system manifestations of COVID-19 are documented, but this case demonstrates that COVID-19 can result in cerebellar dysfunction as well. Conclusion: COVID-19 is caused by SARS-CoV-2, a virus that enters host cells via a receptor primarily found on pneumocytes but also neurons and glial cells. As such, the most common presenting symptoms are respiratory. Here we present a case of a patient presenting with neurological dysfunction in addition to the established respiratory symptoms. Highlights: Our patient presented with encephalopathy, worsened essential tremor, and cerebellar dysfunction, which is an unusual presentation of COVID-19.-In an ongoing pandemic, it is important to have a high index of suspicion, even when patients present with atypical symptoms -It is unclear at this time if hydroxychloroquine and azithromycin should be the treatment of choice for COVID-19, but the regimen was successful in this patient.https://scholarlycommons.henryford.com/merf2020caserpt/1049/thumbnail.jp

    Pandemic Emergency Department Triage Screening: Symptoms Increase Sensitivity

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    INTRODUCTION: In the weeks following the January 20, 2020, announcement of the first confirmed case of COVID-19 in the United States, valuable data was published on the clinical characteristics, including the most common presenting symptoms of individuals affected with the disease. One study in Wuhan, China, identified fever (43.8% on admission and 88.7% during hospitalization) and cough (67.8%) as common symptoms. A second study in Washington State identified shortness of breath as an initial symptom in 76% of patients. This case highlights the importance of rapid incorporation of updated data on the symptomatology of diseases into triage screening questionnaires during pandemics. CASE REPORT: Days after the World Health Organization’s March 11, 2020 declaration of a pandemic, a 37-year-old female presented to our Emergency Department (ED) with a 4-day history of cough, shortness of breath, myalgias, and fever. In triage, the patient was asked if she had traveled outside of the United States and if she had close contact with any person that had laboratory-confirmed COVID-19, for which she answered no. While waiting to be evaluated, the patient spent approximately 40 minutes in triage and an ED hallway before the possibility of COVID-19 was considered. At that point, airborne isolation precautions were ordered. Upon further questioning, the patient revealed she had taken a public bus trip to Florida, 6 days prior. She stated that several passengers on the bus were complaining of flu-like symptoms and were coughing. Upon arrival in Florida, the patient began developing a cough. As her symptoms progressed she also developed headache, nausea, and diarrhea, prompting her to return to Detroit to seek medical attention. The patient had multiple chronic health conditions, including hypertension, insulin-dependent type 2 diabetes, and obesity with a BMI of 48. The patient was subsequently admitted and was later confirmed to be positive for COVID-19. DISCUSSION: Historically, beta-coronaviruses have high rates of transmissibility in healthcare settings. A review of a 2014 MERS outbreak in Saudi Arabia classified 43.5% of all cases as nosocomial infections, while other outbreaks in Saudi Arabia in 2013 and South Korea in 2015 linked 100% to healthcare settings. Studies of the 2002-2003 SARS outbreak found that 21% of all cases occurred in healthcare workers and that the admission of a single index patient in one hospital led to a disastrous superspreading that infected 76 individuals. Data for COVID-19 is still limited, but one series in Wuhan, China presumed that 29% of hospitalized patients with COVID-19 pneumonia acquired the disease in a healthcare setting. It is important to maximize the utility of any tool that has the potential to reduce exposure of a contagious disease to healthcare workers and hospital patrons. Containment and isolation practices are significantly less effective during pandemics that have asymptomatic carriers and lengthy pre-symptomatic states, hence we should not lose opportunities to immediately isolate individuals who are showing symptoms. Another important consideration is that all SARS superspreaders were symptomatic. This case highlights the importance of rapid incorporation of updated data on the symptomatology of a disease into triage screening questionnaires in the setting of an evolving pandemic. This patient presented to our emergency department with a constellation of symptoms that were associated with COVID-19. She had close contact with individuals with the same symptoms while traveling. However, the triage screening questions utilized were not sensitive enough. Shortly after this incident, our institution modified the questionnaire to include specific symptoms associated with the disease, including fever, cough, shortness of breath, and myalgias, which would have potentially identified this patient earlier and expedited the placement of isolation orders.https://scholarlycommons.henryford.com/merf2020caserpt/1115/thumbnail.jp
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