scholarly journals Estimating the Ice Crystal Enhancement Factor in the Tropics

2011 ◽  
Vol 68 (7) ◽  
pp. 1424-1434 ◽  
Author(s):  
Xiping Zeng ◽  
Wei-Kuo Tao ◽  
Toshihisa Matsui ◽  
Shaocheng Xie ◽  
Stephen Lang ◽  
...  
Keyword(s):  
Ice Crystal ◽  
Middle Latitudes ◽  
Ice Nuclei ◽  
Significant Difference ◽  
Physically Based ◽  
Cloud Resolving Model ◽  
The Difference ◽  
The Tropics ◽  
Cloud Condition

Abstract The ice crystal enhancement (IE) factor, defined as the ratio of the ice crystal to ice nuclei (IN) number concentrations for any particular cloud condition, is needed to quantify the contribution of changes in IN to global warming. However, the ensemble characteristics of IE are still unclear. In this paper, a representation of the IE factor is incorporated into a three-ice-category microphysical scheme for use in long-term cloud-resolving model (CRM) simulations. Model results are compared with remote sensing observations, which suggest that, absent a physically based consideration of how IE comes about, the IE factor in tropical clouds is about 103 times larger than that in midlatitudinal ones. This significant difference in IE between the tropics and middle latitudes is consistent with the observation of stronger entrainment and detrainment in the tropics. In addition, the difference also suggests that cloud microphysical parameterizations depend on spatial resolution (or subgrid turbulence parameterizations within CRMs).

An Indirect Effect of Ice Nuclei on Atmospheric Radiation

2009 ◽  
Vol 66 (1) ◽  
pp. 41-61 ◽  
Author(s):  
Xiping Zeng ◽  
Wei-Kuo Tao ◽  
Minghua Zhang ◽  
Arthur Y. Hou ◽  
Shaocheng Xie ◽  
...  
Keyword(s):  
Indirect Effect ◽  
Large Scale ◽  
Three Dimensional ◽  
Radiative Flux ◽  
Middle Latitudes ◽  
Ice Nuclei ◽  
Cloud Resolving Model ◽  
Ice Content ◽  
Cloud Ice ◽  
The Tropics

Abstract A three-dimensional cloud-resolving model (CRM) with observed large-scale forcing is used to study how ice nuclei (IN) affect the net radiative flux at the top of the atmosphere (TOA). In all the numerical experiments carried out, the cloud ice content in the upper troposphere increases with IN number concentration via the Bergeron process. As a result, the upward solar flux at the TOA increases whereas the infrared one decreases. Because of the opposite response of the two fluxes to IN concentration, the sensitivity of the net radiative flux at the TOA to IN concentration varies from one case to another. Six tropical and three midlatitudinal field campaigns provide data to model the effect of IN on radiation in different latitudes. Classifying the CRM simulations into tropical and midlatitudinal and then comparing the two types reveals that the indirect effect of IN on radiation is greater in the middle latitudes than in the tropics. Furthermore, comparisons between model results and observations suggest that observational IN data are necessary to evaluate long-term CRM simulations.

scholarly journals Validation of six years of TES tropospheric ozone retrievals with ozonesonde measurements: implications for spatial patterns and temporal stability in the bias

2013 ◽  
Vol 6 (5) ◽  
pp. 1413-1423 ◽  
Author(s):  
W. W. Verstraeten ◽  
K. F. Boersma ◽  
J. Zörner ◽  
M. A. F. Allaart ◽  
K. W. Bowman ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
A Priori ◽  
Temporal Stability ◽  
Lower Troposphere ◽  
Temporal Variations ◽  
Upper Troposphere ◽  
The World ◽  
The Difference ◽  
The Tropics

Abstract. In this analysis, Tropospheric Emission Spectrometer (TES) V004 nadir ozone (O3) profiles are validated with more than 4400 coinciding ozonesonde measurements taken across the world from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC) during the period 2005–2010. The TES observation operator was applied to the sonde data to ensure a consistent comparison between TES and ozonesonde data, i.e. without the influence of the a priori O3 profile needed to regulate the retrieval. Generally, TES V004 O3 retrievals are biased high by 2–7 ppbv (7–15%) in the troposphere, consistent with validation results from earlier studies. Because of two degrees of freedom for signal in the troposphere, we can distinguish between upper and lower troposphere mean biases, respectively ranging from −0.4 to +13.3 ppbv for the upper troposphere and +3.9 to +6.0 ppbv for the lower troposphere. Focusing on the 464 hPa retrieval level, broadly representative of the free tropospheric O3, we find differences in the TES biases for the tropics (+3 ppbv, +7%), sub-tropics (+5 ppbv, +11%), and northern (+7 ppbv, +13%) and southern mid-latitudes (+4 ppbv, +10%). The relatively long-term record (6 yr) of TES–ozonesonde comparisons allowed us to quantify temporal variations in TES biases at 464 hPa. We find that there are no discernable biases in each of these latitudinal bands; temporal variations in the bias are typically within the uncertainty of the difference between TES and ozonesondes. Establishing these bias patterns is important in order to make meaningful use of TES O3 data in applications such as model evaluation, trend analysis, or data assimilation.

scholarly journals Impact of Fluoroquinolone Exposure Prior to Tuberculosis Diagnosis on Clinical Outcomes in Immunocompromised Patients

2016 ◽  
Vol 60 (7) ◽  
pp. 4005-4012 ◽  
Author(s):  
Ju Young Lee ◽  
Hyun Jung Lee ◽  
Yong Kyun Kim ◽  
Shinae Yu ◽  
Jiwon Jung ◽  
...  
Keyword(s):  
Median Time ◽  
Tertiary Care ◽  
Adverse Outcomes ◽  
Care Hospital ◽  
Immunocompromised Patients ◽  
Tb Treatment ◽  
Significant Difference ◽  
Tuberculosis Diagnosis ◽  
The Difference

ABSTRACTThere have been concerns about an association of fluoroquinolone (FQ) use prior to tuberculosis (TB) diagnosis with adverse outcomes. However, FQ use might prevent clinical deterioration in missed TB patients, especially in those who are immunocompromised, until they receive definitive anti-TB treatment. All adult immunocompromised patients with smear-negative and culture-positive TB at a tertiary care hospital in Korea over a 2-year period were included in this study. Long-term FQ (≥7 days) use was defined as exposure to FQ for at least 7 days prior to TB diagnosis. A total of 194 patients were identified: 33 (17%) in the long-term FQ group and 161 (83%) in the comparator, including a short-term FQ group (n= 23), non-FQ group (n= 78), and a group receiving no antibiotics (n= 60). Patients in the long-term FQ group presented with atypical chest radiologic pattern more frequently than those in the comparator (77% [24/31] versus 46% [63/138];P= 0.001). The median time from mycobacterial test to positive mycobacterial culture appeared to be longer in the long-term FQ group (8.1 weeks versus 7.7 weeks;P= 0.09), although the difference was not statistically significant. Patients in the long-term FQ group were less likely to receive empirical anti-TB treatment (55% versus 74%;P= 0.03). The median time from mycobacterial test to anti-TB therapy was longer in the long-term FQ group (4.6 weeks versus 2.2 weeks;P< 0.001), but there was no significant difference in FQ resistance (0% versus 3%;P> 0.99) or in the 30-day (6% versus 6%;P> 0.99) or 90-day (12% versus 12%;P> 0.99) mortality rate between the two groups. FQ exposure (≥7 days) prior to TB diagnosis in immunocompromised patients appears not to be associated with adverse outcomes.

scholarly journals Preventive effect of ursodeoxycholic acid on parenteral nutrition-associated liver disease in infants

2014 ◽  
Vol 142 (3-4) ◽  
pp. 184-188 ◽  
Author(s):  
Dusica Simic ◽  
Irina Milojevic ◽  
Dragana Bogicevic ◽  
Miodrag Milenovic ◽  
Vladimir Radlovic ◽  
...  
Keyword(s):  
Birth Weight ◽  
Parenteral Nutrition ◽  
Ursodeoxycholic Acid ◽  
Average Duration ◽  
Surgical Patients ◽  
Control Group ◽  
Surgical Patient ◽  
Significant Difference ◽  
The Difference

Introduction. Parenteral nutrition-associated cholestasis is well recognized phenomenon in the term and preterm infant receiving long-term parenteral nutrition. Objectives. The aim of this study was to evaluate the effect of ursodeoxycholic acid (UDCA) use on cholestasis in newborns on prolonged TPN. Methods. A total of 56 infants were enrolled in this retrospective study: control group consisted of lower (1500 g) birth weight infants (n=30), as well as the group of pediatric (n=11) and surgical patients (n=15) treated with UDCA. Blood chemistries were obtained two times weekly. Results. All of 56 newborns developed cholestasis but duration of parenteral nutrition (PN) before onset of cholestasis was significantly longer in UDCA treated patients. Average duration of PN before the onset of cholestasis in control group of patients was 25 days in distinction from treated pediatric and surgical patients (39 and 34 days, respectively). The peak serum conjugated bilirubin (CB), AST, ALT and alkaline phosphatase (AP) levels were significantly lower in the treated groups. There was no significant difference among treated pediatric and surgical patients and between lower and higher birth weight infants considering the CB, ALT, AST and AP peak. Duration of cholestasis was significantly decreased in all treated groups. There was a significant difference in time needed to achieve complete enteral intake between pediatric and surgical patient group. Conclusion. Cholestasis developed significantly later in treated groups than in the controls. UDCA appears to be very successful in reducing the symptoms of cholestasis. The difference in efficacy of UDCA treatment between lower and higher birth weight infants could not be proven.

Effect of Probiotic Yogurt and Xylitol-Containing Chewing Gums on Salivary S Mutans Count

2017 ◽  
Vol 41 (4) ◽  
pp. 257-263 ◽  
Author(s):  
Elnaz Ghasemi ◽  
Romina Mazaheri ◽  
Arezoo Tahmourespour
Keyword(s):  
Test Results ◽  
Gastrointestinal Health ◽  
Probiotic Yogurt ◽  
Colony Forming Units ◽  
Chewing Gums ◽  
Significant Difference ◽  
The Difference ◽  
To Receive ◽  
Difference Test

Background and Aims: In addition to improving gastrointestinal health and intestinal microflora, probiotic bacteria have been recently suggested to decrease cariogenic agents in the oral cavity. The aim of this study was to investigate the effects of probiotic yogurt and xylitol-containing chewing gums on reducing salivary Streptococcus mutans levels. Study design: This randomized clinical trial recruited 50 female students with over 105 colony forming units S. mutans per milliliter of their saliva. The participants were randomly allocated to two equal groups to receive either probiotic yogurt containing Lactobacillus acidophilus ATCC 4356 andBifidobacteriumbifidum ATCC 29521 (200 g daily) or xylitol-containing chewing gums (two gums three times daily after each meal; total xylitol content: 5.58 g daily) for three weeks. At baseline and one day, two weeks, and four weeks after the interventions, saliva samples were cultured on mitis-salivarius-bacitracin agar and salivary S. mutans counts were determined. Data were analyzed with independent t-tests, analysis of variance, and Fisher's least significant difference test. Results: In both groups, S. mutans counts on the first day, second week, and fourth weeks after the intervention were significantly lower than baseline values (P &lt; 0.05). The greatest level of reduction in both groups was observed in the second week after the intervention. Moreover, although the reduction was greater in probiotic yogurt consumers, the difference between the two groups was not statistically significant. Conclusion: Probiotic yogurt and xylitol-containing chewing gums seem to be as effective in reduction of salivary S. mutans levels. Their constant long-term consumption is thus recommended to prevent caries.

scholarly journals Numerical Simulations of Heavy Rainfalls by a Global Cloud-Resolving Model

2008 ◽  
Vol 3 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Masaki Satoh ◽  
◽  
Keyword(s):  
Weather Forecasting ◽  
Global Climate ◽  
Climate Simulation ◽  
Short Term ◽  
Cloud Resolving Model ◽  
Numerical Weather Forecasting ◽  
Simulation Results ◽  
Tropical Weather ◽  
The Tropics

The Global Cloud-Resolving Model is a next-generation atmospheric global model with potential to open up new areas in numerical weather forecasting and climate simulation. The new model, called NICAM, has shown realistic behavior for precipitation systems over the global domain, particularly over the tropics. One impact of the global cloud-resolving model is the attainment of realistic simulation of rainfall in the tropics realizing a multiscale nature from kilometer to planetary, because rainfall in the tropics affects short-term local tropical weather and the long-term global climate. We review the global cloud-resolving model using simulation results from NICAM, and discuss its applicability in reducing natural weather disasters.

scholarly journals The Effect of long-term awareness on active and passive tobacco smokers

2021 ◽  
Vol 12 (1) ◽  
pp. 439-446
Author(s):  
Serkan KÖKSOY ◽  
Fatih KARA
Keyword(s):  
Passive Smoking ◽  
Intervention Group ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Control Groups ◽  
Tobacco Products ◽  
Significant Difference ◽  
The Difference ◽  
The Impact

Tobacco addiction is a major public health problem. Numerous scientific studies have been conducted on the harms of tobacco products. However, the number of intervention studies investigating the effect of long-term awareness of the harm of tobacco products on the Fagerström Test for Nicotine Dependence (FTND), Carbon Monoxide (CO), Carboxyhemoglobin (COHb) and Respiratory Function Test (RFT) are limited. Our goal is to investigate the impact of long-term scientific awareness on these parameters. The study was designed an intervention study on active and passive smoking participants and their control groups. Control groups were not given any training on the harms of tobacco products. When comparing the first and last weeks in active smoker intervention group (ASIG), the difference between FTND, FEV1, CO, and COHb parameters was observed to be statistically significant (p<0.05). The highest decrease in ASIG was in CO (↓60%) parameter and the highest increase was in the FEV1(↑%10) parameter. There was a significant difference both FEV1, FVC, FEV1/FVC (p<0.05) and CO parameters of passive smokers intervention group (PSIG). The highest decrease in PSIG was in the CO parameter (↓%65.8) and the highest increase was in the FVC (↑%10) parameter. Awareness programs may reduce the severity of addiction in active smokers and may help protect passive smokers. As awareness increases, positive changes in some vital parameters may be possible. Up-to-date programs and policies are needed to make easy and sustainable awareness of both active and passive smoking.

Viscocanalostomy with Mitomycin-C: A Preliminary Study

2005 ◽  
Vol 15 (2) ◽  
pp. 202-208 ◽  
Author(s):  
A. Yarangümeli ◽  
ö. Gürbüz Köz ◽  
M.N. Alp ◽  
A.H. Elhan ◽  
G. Kural
Keyword(s):  
Mitomycin C ◽  
Long Term Results ◽  
Success Rates ◽  
Surgical Success ◽  
Significant Difference ◽  
The Difference ◽  
Group 2 ◽  
Conjunctival Bleb ◽  
Group 1

Purpose To compare the results of viscocanalostomy with and without mitomycin-C (MMC). Methods Retrospective results of 15 standard viscocanalostomy (VCO) operations (Group 1) were compared with the prospective results of 15 VCO operations performed with intraoperative adjunctive MMC (Group 2). MMC (0.2 mg/mL) was applied over and under the superficial scleral flap for 3 minutes in Group 2 before the deep flap was prepared. Each patient was followed up for at least 1 year, and results of examinations in the first 12 months were used in the statistical comparison of the two groups. Surgical success was defined as intraocular pressure (IOP) ≤ 18 mmHg. Results Pr eoperative mean intraocular pressures (IOP) in Group 1 and Group 2 wer e 35.3±11.0 and 39.1±8.9, respectively. Mean IOP levels at the 12th month were 14.4±2.6 and 11.9±4.0, respectively, showing a significant decrease in both groups (p<0.001). Postoperative IOP course appeared to be lower in the MMC group, however, the difference was not statistically significant (p=0.554). Complete success rates without medications were 40% in Group 1 and 67% in Group 2. No significant difference was found between the two groups in terms of early and late postoperative complications, pre- and postoperative number of antiglaucoma medications, and surgical success rates at the end of the study period (p>0.05 for all). A significant difference was verified between the two groups of eyes considering the conjunctival bleb types, as low-lying, localized blebs were the most frequent type in Group 1 and thin-walled, avascular blebs were more predominant in the MMC group (p=0.004). Conclusions Intraoperative adjunctive MMC use might improve the long-term results of viscocanalostomy by facilitating subconjunctival filtration and might widen the indication range of the technique.

scholarly journals Delayed measles mortality among exposed children who survived the epidemic of 1714–15 in New France

2013 ◽  
Vol 39 (3-4) ◽  
pp. 9 ◽  
Author(s):  
Ryan Mazan
Keyword(s):  
New France ◽  
Male And Female ◽  
Follow Up Study ◽  
Significant Difference ◽  
Delayed Mortality ◽  
The Difference ◽  
Age And Sex ◽  
Long Term Mortality

This follow-up study examines delayed mortality of children under age 5 who were exposed to measles and survived the acute phase ofthe 1714–15 epidemic in Quebec. The objective of the study was to assess whether exposed children had higher long-term mortality thanunexposed children, by following them for 25 months past the estimated date of infection. Overall, children exposed before age 3 had higher long-term mortality than unexposed children. The difference remained significant while assessing other risk factors. Delayed mortality also varied by age and sex. Only exposed female infants had a significantly higher risk of dying, while both exposed male and female toddlers had higher mortality. No significant difference was found among children exposed after age 3. Findings are explained in terms of modern post-measles studies in Africa and of previous measles studies in New France.

Access to long-term care: perceptions and experiences of older Dutch people

2015 ◽  
Vol 16 (2) ◽  
pp. 83-93 ◽  
Author(s):  
Lisette Schipper ◽  
Katrien G. Luijkx ◽  
Bert R. Meijboom ◽  
René Schalk ◽  
Jos M.G.A. Schols
Keyword(s):  
Older People ◽  
Long Term Care ◽  
Term Care ◽  
Content Type ◽  
Care Access ◽  
Care Services ◽  
Significant Difference ◽  
Access Service ◽  
The Difference

Purpose – Despite the current focus on demand-based care, little is known about what clients consider important when they have a request for formal long-term care services. The paper aims to discuss this issue. Design/methodology/approach – Questions about the access process to care services were added to the “Senior Barometer”, a Dutch web-based questionnaire that assesses the opinion of older people about different aspects in life. The questionnaire surveyed both people who already requested care services (“users”), and people that did not (“future clients”). Findings – The results show a significant difference in what people expect to be the first step from what users actually did, when requesting formal care services. In addition, there was a significant difference on how “users” and “future clients” rated several access service aspects. Research limitations/implications – The results give valuable information on how both “users” and “future clients” value the access process. The findings also provide valuable input for organizations providing long-term care for older clients about the important issues that have to be considered when organizing the access process. Originality/value – This study shows what older people in the Netherlands find important during the access process to care and this has not been explored before. The difference between what “users” and “future clients” find of importance in the care access process suggests that it is difficult for people to foresee what will be important once the need for care arrives, or where they will turn to with a request for care services.

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