Search

There is a debate about unmatched results between manipulative warming using constant warming rates every year (CW) and long-term observations warming affect temperature sensitivity of flowering phenology. This may be because long-term observations represent the actual yearly increase in temperature (i.e. a yearly stepwise warming rate per year, SW) which would differ from CW and their effects would be regulated by precipitation alteration. We conducted a warming experiment with CW (temperature increase by +1 °C and sustained this elevated temperature for the duration of the study) and SW (temperature increase by + 0.25 °C progressively each year) with precipitation addition in an alpine grassland for four years. Our results showed that neither warming rate affected community flowering phenology. However, precipitation addition advanced onsets of flowering for early-spring flowering (ESF) and mid-summer flowering (MSF) groups, and advanced the end date of flowering for ESF but delayed it for the MSF group. Therefore, flowering duration remained stable for the ESF group and prolonged for the MSF group, and further prolonging the flowering duration of the community. There were no interactions between warming rates and precipitation addition on the community's flowering phenology. A severe drought in a year significantly decreased the maximal number of community flowers in the following year. Therefore, a change in precipitation has a greater effect than warming on the community flowering phenology in the semi-arid alpine grassland. [ABSTRACT FROM AUTHOR]

Fine-root decomposition is a critical process regulating ecosystem carbon cycles and affecting nutrient cycling and soil fertility. However, whether interaction between warming and grazing affects fine-root decomposition is still under-researched in natural grasslands. A two-factorial experiment with asymmetric warming (i.e. daytime vs. nighttime and growing season vs. nongrowing season) and moderate grazing (i.e. about average 50% forage utilization rate) was conducted to explore whether warming and grazing affect fine-root decomposition and loss of nutrients during a 2-year decomposition period in an alpine meadow on the Tibetan Plateau. Both warming and grazing facilitated carbon cycling through increase in fine-root decomposition, and influenced element cycling which varies among elements. The effects of warming and grazing on fine-root decomposition and loss of nutrients were additive. Both warming and grazing significantly increased cumulative percentage mass loss and total organic carbon loss of fine roots during the 2-year experiment. Only warming with grazing treatment reduced percentage nitrogen loss, whereas warming, regardless of grazing, decreased percentage phosphorus loss. Warming and grazing alone increased percentage loss of potassium, sodium, calcium and magnesium compared with control. There were no interactions between warming and grazing on fine-root decomposition and loss of nutrients. There was greater temperature sensitivity of decreased phosphorus loss than that of decreased nitrogen loss. Different temperature sensitivities of percentage loss of nutrients from fine-root decomposition would alter ratios of the available nutrients in soils, and may further affect ecosystem structure and functions in future warming. [ABSTRACT FROM AUTHOR]

Warming and grazing, and litter quality jointly determine litter decomposition and nutrient releases in grazing ecosystems. However, their effects have previously been studied in isolation. We conducted a two factorial experiment with asymmetric warming using infrared heaters and moderate grazing in an alpine meadow. Litter samples were collected from all plots in each treatment, among which some subsamples were placed in their original plots and other samples were translocated to other treatment plots to test the relative effects of each treatment on litter decomposition and nutrient releases. We found that warming rather than grazing alone significantly increased total losses of litter mass, total organic carbon, total nitrogen (TN) and total phosphorus (TP) per unit area due to increases in both mass loss rates and litter biomass. However, grazing with warming did not affect their total mass losses because increased mass loss was offset by decreased litter biomass compared with the control. Seasonal mean soil temperature better predicted litter decomposition than litter lignin content or carbon to nitrogen ratio. There were interactions between warming and grazing, but there were no interactions between them and litter quality on litter decomposition. The temperature sensitivity of TN loss was higher than that of TP loss per unit area. Our results suggest that increased temperature has a greater effect on litter decomposition and nutrient release than change in litter quality, and that more N release from litter could result in greater P deficiency in the alpine meadow. [ABSTRACT FROM AUTHOR]

Monitoring outcomes of health care providers, such as patient deaths, hospitalizations, and hospital readmissions, helps in assessing the quality of health care. We consider a large database on patients being treated at dialysis facilities in the United States, and the problem of identifying facilities with outcomes that are better than or worse than expected. Analyses of such data have been commonly based on random or fixed facility effects, which have shortcomings that can lead to unfair assessments. A primary issue is that they do not appropriately account for variation between providers that is outside the providers' control due, for example, to unobserved patient characteristics that vary between providers. In this article, we propose a smoothed empirical null approach that accounts for the total variation and adapts to different provider sizes. The linear model provides an illustration that extends easily to other non-linear models for survival or binary outcomes, for example. The empirical null method is generalized to allow for some variation being due to quality of care. These methods are examined with numerical simulations and applied to the monitoring of survival in the dialysis facility data. [ABSTRACT FROM AUTHOR]

Background The course of disease in mild and moderate COVID-19 has many implications for mobile patients, such as the risk of spread of the infection, precautions taken, and investigations targeted at preventing transmission. Methods Three hundred thirty-one adults were hospitalized from January 21 to February 22, 2020, and classified as severe (10%) or critical (4.8%) cases; 1.5% died. Two hundred eighty-two (85.2%) mild or moderate cases were admitted to regular wards. Epidemiological, demographic, clinical, chest computed tomography (CT) scan, laboratory, treatment, and outcome data from patient records were analyzed retrospectively. Results Patients were symptomatic for 9.82±5.75 (1–37) days. Pulmonary involvement was demonstrated on a chest CT scan in 97.9% of cases. It took 16.81±8.54 (3–49) days from the appearance of the first symptom until 274 patients tested virus-negative in naso- and oropharyngeal (NP) swabs, blood, urine, and stool, and 234 (83%) patients were asymptomatic for 9.09±7.82 (1–44) days. Subsequently, 131 patients were discharged. One hundred sixty-nine remained in the hospital; these patients tested virus-free and were clinically asymptomatic because of widespread persisting or increasing pulmonary infiltrates. Hospitalization took 16.24±7.57 (2–47) days; the time interval from the first symptom to discharge was 21.37±7.85 (3–52) days. Conclusions With an asymptomatic phase, disease courses are unexpectedly long until the stage of virus negativity. NP swabs are not reliable in the later stages of COVID-19. Pneumonia outlasts virus-positive tests if sputum is not acquired. Imminent pulmonary fibrosis in high-risk groups demands follow-up examinations. Investigation of promising antiviral agents should heed the specific needs of mild and moderate COVID-19 patients. [ABSTRACT FROM AUTHOR]

Background We aimed to evaluate the antiviral activity and safety of darunavir/cobicistat (DRV/c) in treating COVID-19 patients. Methods In this single-center, randomized, and open-label trial, mild patients with polymerase chain reaction (PCR)–confirmed COVID-19 were enrolled in Shanghai, China. Participants were randomized to receive DRV/c for 5 days on the top of interferon alpha 2b inhaling or interferon alpha 2b inhaling alone. The primary end point was the virological clearance rate of oropharyngeal swabs at day 7 after randomization in the intention-to-treat population (clinicaltrials.gov: NCT04252274). Results From January 30, 2020, to February 6, 2020, a total of 30 patients were enrolled, of whom 18 (60%) were male, aged 47.2 ± 2.8 years; 63.3% (19/30) of the participants had fever, and 46.7% (14/30) had cough at enrollment. The participants were randomized (range) at 4 (2–5) days after onset of symptoms. The proportion of negative PCR results at day 7 was 46.7% (7/15) and 60.0% (9/15) in the DRV/c and control groups (P  = .72), respectively. The viral clearance rate at day 3 was 20% (3/15) in both study groups, while the number increased to 26.7% (4/15) in the DRV/c group and remained 20% (3/15) in the control group at day 5. Fourteen days after randomization, 1 participant in the DRV/c group progressed to critical illness and discontinued DRV/c, while all the patients in the control group were stable (P  = 1.0). The frequencies of adverse events in the 2 groups were comparable. Conclusions Five days of DRV/c did not increase the proportion of negative conversion vs standard of care alone, although it was well tolerated. [ABSTRACT FROM AUTHOR]

We report a case of primary cutaneous zygomycosis caused byRhizomucor variabilis and review 6 cases reported from China that share similar features and are different from those cases caused by other species of Mucorales. It is noteworthy that all 6 of the cases were observed in 3 adjacent provinces of eastern China. [ABSTRACT FROM AUTHOR]