scholarly journals Does extracellular DNA mask microbial responses to a pulse disturbance?

2021 ◽  
Author(s):  
HA Kittredge ◽  
KM Dougherty ◽  
K Glanville ◽  
SE Evans
Keyword(s):  
Microbial Communities ◽  
Bacterial Communities ◽  
Statistical Significance ◽  
A Priori ◽  
Extracellular Dna ◽  
Pulse Disturbance ◽  
Viable Cells ◽  
Before And After ◽  
Significance Levels ◽  
Microbial Responses

AbstractA major goal in microbial ecology is to predict how microbial communities will respond to global change. However, DNA-based sequencing that is intended to characterize live microbial communities includes extracellular DNA (exDNA) from non-viable cells. This could obscure relevant microbial responses, particularly to pulse disturbances which kill bacteria and have disproportionate effects on ecosystems. Here, we characterize bacterial communities before and after a drying-rewetting pulse disturbance, using an improved method for exDNA exclusion. We find that exDNA removal is important for detecting subtle yet significant changes in microbial abundance, diversity, and community composition across the disturbance. However, inclusion of exDNA did not obscure results to a large extent, only sometimes altering statistical significance but rarely changing the direction of the response or general conclusions about bacterial disturbance dynamics. Although there may be instances where exDNA removal is essential for accurate representation of microbial communities, our study suggests these scenarios will be difficult to predict a priori. Overall, we found no evidence that certain time points across the distrubance were more affected by exDNA inclusion, nor did the size or composition of exDNA pools accurately predict when exDNA would alter significance levels. However, exDNA dynamics did vary strongly across the two soil types tested.

Microbial responses to drying and rewetting in soils across a European climate transect

2021 ◽  
Author(s):  
Sara Winterfeldt ◽  
Ainara Leizeaga ◽  
Johannes Rousk
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Properties ◽  
Microbial Communities ◽  
Bacterial Growth ◽  
Bacterial Communities ◽  
Recovery Time ◽  
Soil Microbial Communities ◽  
Drying And Rewetting ◽  
Microbial Responses

<p>Climate change results in more frequent and intensified drought and rainfall events. The environment exerts a strong control on microbial communities, where drying and rewetting disturbances act as an additional stress that can alter soil processes driving the carbon cycle. Therefore, understanding the environmental control of microbial responses to drying and rewetting events is important to understand the microbial mechanisms controlling the soil C cycle. This study investigated how climate along with soil physiochemical factors affected microbial responses to drying and rewetting. A total of 40 soils across Europe presenting a comprehensive gradient from arctic (N Sweden) to southern Mediterranean (S Greece) climates and wide range of soil properties (SOM: 2-82%, pH: 3.9-7.4, Clay: 8-79%) were exposed to four days of drying followed by rewetting. The microbial growth and respiration responses after rewetting were monitored in high time resolution during 32h. The recovery time of bacterial growth to rates of 50% in undisturbed soil was used as a measure of how resilient microbial communities were to drying and rewetting.</p><p> </p><p>The bacterial recovery time after rewetting ranged between 0.6-40h. We found that soils in arid climates had faster bacterial recovery times, suggesting that bacterial communities were more resilient and better adapted to drying and rewetting than those in humid climates, rendering microbial C-use during drying and rewetting more efficient. Furthermore, pH and soil organic matter also had pronounced effects on the resilience of bacterial growth, where acid pH and high soil organic matter resulted in bacterial communities that were slower to recover. In contrast, clay did not have an influence on the resilience of bacterial growth. Our findings suggest that both climate and soil properties are important when determine how soil microbial communities will respond to a drying and rewetting disturbance.</p>

Treating Velopharyngeal Inadequacy Using Bilateral Buccal Flap Revision Palatoplasty

2019 ◽  
Vol 4 (5) ◽  
pp. 878-892
Author(s):  
Joseph A. Napoli ◽  
Linda D. Vallino
Keyword(s):  
Systematic Review ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
A Priori ◽  
Sufficient Evidence ◽  
Obstructive Sleep ◽  
Before And After ◽  
Buccal Flap

Purpose The 2 most commonly used operations to treat velopharyngeal inadequacy (VPI) are superiorly based pharyngeal flap and sphincter pharyngoplasty, both of which may result in hyponasal speech and airway obstruction. The purpose of this article is to (a) describe the bilateral buccal flap revision palatoplasty (BBFRP) as an alternative technique to manage VPI while minimizing these risks and (b) conduct a systematic review of the evidence of BBFRP on speech and other clinical outcomes. A report comparing the speech of a child with hypernasality before and after BBFRP is presented. Method A review of databases was conducted for studies of buccal flaps to treat VPI. Using the principles of a systematic review, the articles were read, and data were abstracted for study characteristics that were developed a priori. With respect to the case report, speech and instrumental data from a child with repaired cleft lip and palate and hypernasal speech were collected and analyzed before and after surgery. Results Eight articles were included in the analysis. The results were positive, and the evidence is in favor of BBFRP in improving velopharyngeal function, while minimizing the risk of hyponasal speech and obstructive sleep apnea. Before surgery, the child's speech was characterized by moderate hypernasality, and after surgery, it was judged to be within normal limits. Conclusion Based on clinical experience and results from the systematic review, there is sufficient evidence that the buccal flap is effective in improving resonance and minimizing obstructive sleep apnea. We recommend BBFRP as another approach in selected patients to manage VPI. Supplemental Material https://doi.org/10.23641/asha.9919352

STUDY CLINICAL FEATURE AND RESULT OF TREATMENT PHACOMORPHIC GLAUCOMA

2015 ◽  
pp. 71-75
Author(s):  
Van Nam Phan ◽  
Ba Ken Tran
Keyword(s):  
Visual Acuity ◽  
Intraocular Pressure ◽  
Statistical Significance ◽  
Corneal Edema ◽  
Clinical Feature ◽  
Anterior Chamber Angle ◽  
Male Population ◽  
Significant Difference ◽  
Operative Complications ◽  
Before And After

Purpose: Study clinical feature of phacomorphic glaucoma. To evaluate the result of treatment phacomorphic glaucoma. Method: The retrospective, interventional study on 36 cases with phacomorphic glaucoma who underwent treated at Hue Central Hospital from 6/2010 to 6/2011. Standard of research: visual, IOP, before and after surgery, accompanying lesions and post-operative complications. The surgery is considered successful when postoperative IOP less than 21 mmHg. Results: Age 50-59 presented 30.5 percent, ≥ 60 presented 91.7 percent. There was a slight female preponderance (66.7%) compared to the male population (33.3%) which implies a statistically marginally significant difference. However there was no statistical significance difference when compared by the two subgroups. Patient in country presented 61,1% and city presented 38,9%. The duration between the onset of pain and surgery from 0 to < 5 days (77.8%), from 6 to 10 (16.7%) and >10 days presented 5.5%. The preoperative intraocular pressure 35 to 45mmHg (47.2%), 46-55 (30.6%), 56-65 (13.9%) and more than 65 presented 8.3%. The visual acuity preoperation less than 1metre count finger (94.5%), less than 3 metre count finger presented 5.5%. Close anterior chamber angle presented 80.6% and shallow was presented 19.4%. Corneal edema presented 100%, iritis presented 94.4%, dilated pupil larger 5mm presented 83.3%, Synchynea iris and cataract presented 72.2%. ECCE, implantation IOL combined trabeculectomy presented 11.1%, Phaco, implantation IOL combined trabeculectomy presented 69,5%, ECCE implantation IOL presented 5.6%, Phaco, implantation IOL presented 13.8%. Postoperative visual acuity from 1/10 to 5/10 presented 72.2%, no case have VA larger than 5/10. Postoperative 3 months VA 1/10 to 5/10 presented 72.2%, larger VA 5/10 presented 8.3%. Postoperative 3 months intraocular pressure ≤ 21mmHg presented 91.7%, 22 to 24mmHg presented 8.3%, no case have IOP ≥25mmHg. Postoperative edema presented 58.3%, iritis presented 58.3%. Key words: phacomorphic Glaucoma

scholarly journals Treatment of HIV-associated facial lipoatrophy: impact on infection progression assessed by viral load and CD4 count

2013 ◽  
Vol 88 (4) ◽  
pp. 570-577 ◽  
Author(s):  
Flávia Machado Gonçalves Soares ◽  
Izelda Maria Carvalho Costa
Keyword(s):  
Viral Load ◽  
Disease Progression ◽  
Statistical Significance ◽  
Undetectable Viral Load ◽  
Fat Distribution ◽  
Cd4 Count ◽  
Before And After ◽  
Facial Lipoatrophy ◽  
A Prospective Study ◽  
The Impact

BACKGROUND: HIV/AIDS-Associated Lipodystrophy Syndrome includes changes in body fat distribution, with or without metabolic changes. The loss of fat from the face, called facial lipoatrophy, is one of the most stigmatizing signs of the syndrome.OBJECTIVES:To evaluate the effect of FL treatment using polymethylmethacrylate (PMMA) implants on disease progression, assessed by viral load and CD4 cell count.METHODS: This was a prospective study of 44 patients treated from July 2009 to December 2010. Male and female patients, aged over 18 years, with clinically detectable FL and who had never been treated were included in the study. PMMA implantation was done to fill atrophic areas. Laboratory tests were conducted to measure viral load and CD4 count before and after treatment.RESULTS: Of the 44 patients, 72.72% were male and 27.27% female, mean age of 44.38 years. Before treatment, 82% of patients had undetectable viral load, which increased to 88.6% after treatment, but without statistical significance (p = 0.67). CD4 count before treatment ranged from 209 to 1293, averaging 493.97. After treatment, the average increased to 548.61. The increase in CD4 count after treatment was statistically significant with p = 0.02.CONCLUSION: The treatment of FL with PMMA implants showed a statistically significant increase in CD4 count after treatment, revealing the impact of FL treatment on disease progression. Viral load before and after treatment did not vary significantly.

The effect of mask use on maternal oxygen saturation in term pregnancies during the COVID-19 process

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Erzat Toprak ◽  
Ayça Nazlı Bulut
Keyword(s):  
Oxygen Saturation ◽  
Pregnant Women ◽  
Stress Test ◽  
Statistical Significance ◽  
Categorical Variables ◽  
Fisher Exact Test ◽  
Coin Toss ◽  
Arterial Blood ◽  
Surgical Masks ◽  
Before And After

AbstractObjectivesOur aim was to evaluate the effect of standard surgical and N-95 respiratory mask use on maternal oxygen saturation, vital signs and result on non-stress tests in term pregnancies.MethodsIt is a prospective observational study. The study included healthy, not in labor, singleton pregnant women of 370/7–410/7 weeks who were applied to our hospital for routine obstetric control examination between March 1, 2020, and August 31, 2020. Patients were randomised by coin toss method. Oxygen saturation, systolic, and diastolic arterial blood pressure, pulse, respiratory rate, and temperature of pregnant women using surgical masks and respiratory masks were measured before and after the non-stress test. The tolerance of the masks was also evaluated. Student’s t-test was used for variables showing parametric distribution and the Mann Whitney U-test was used for non-parametric tests. The categorical variables between the groups was analyzed by using the Chi square test or Fisher Exact test. The statistical significance level was taken as p<0.05 in all tests.ResultsA total of 297 pregnant women using masks were included in the study. The effect of mask type on oxygen saturation before and after the non-stress test was found to be significant (97.1±1.8 corresponds to 95.3±2.6 for the surgical mask, p=0.0001; 97.8±1.7 corresponds to 93.7±2.0 for the respiratory mask, p=0.0001). Mask tolerance of patients using respiratory masks was significantly higher than those using surgical masks (mean 8, 1–10, p=0.0001).ConclusionsSurgical mask and respiratory mask usage decreased significantly in oxygen saturation in term pregnancies.

scholarly journals Gamma entrainment frequency affects mood, memory and cognition: an exploratory pilot study

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Ryan L. S. Sharpe ◽  
Mufti Mahmud ◽  
M. Shamim Kaiser ◽  
Jianhui Chen
Keyword(s):  
Pilot Study ◽  
Correlation Analysis ◽  
Negative Correlation ◽  
Cognitive Abilities ◽  
Statistical Significance ◽  
Assessment Scores ◽  
Frequency Group ◽  
Before And After ◽  
Mood Score ◽  
40 Hz

AbstractHere we provide evidence with an exploratory pilot study that through the use of a Gamma 40 Hz entrainment frequency, mood, memory and cognition can be improved with respect to a 9-participant cohort. Participants constituted towards three binaural entrainment frequency groups: the 40 Hz, 25 Hz and 100 Hz. Participants attended a total of eight entrainment frequency sessions twice over the duration of a 4-week period. Additionally, participants were assessed based on their cognitive abilities, mood as well as memory, where the cognitive and memory assessments occurred before and after a 5-min binaural beat stimulation. The mood assessment scores were collected from sessions 1, 4 and 8, respectively. With respect to the Gamma 40 Hz entrainment frequency population, we observed a mean improvement in cognitive scores, elevating from 75% average to 85% average upon conclusion of the experimentation at weak statistical significance ($$\alpha$$ α = 0.10, p = 0.076). Similarly, memory score improvements at a greater significance ($$\alpha$$ α = 0.05, p = 0.0027) were noted, elevating from an average of 87% to 95%. In pertinence to the mood scores, a negative correlation across all populations were noted, inferring an overall increase in mood due to lower scores correlating with elevated mood. Finally, correlation analysis revealed a stronger R$$^2$$ 2 value (0.9838) within the 40 Hz group between sessions as well as mood score when compared across the entire frequency group cohort.

scholarly journals Diversity and Dynamics of Seaweed Associated Microbial Communities Inhabiting the Lagoon of Venice

2020 ◽  
Vol 8 (11) ◽  
pp. 1657
Author(s):  
Abdul-Salam Juhmani ◽  
Alessandro Vezzi ◽  
Mohammad Wahsha ◽  
Alessandro Buosi ◽  
Fabio De Pascale ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Bacterial Communities ◽  
Host Response ◽  
Environmental Parameters ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Nutrient Concentrations ◽  
Lagoon Of Venice ◽  
Anthropogenic Stressors ◽  
Rich Diversity

Seaweeds are a group of essential photosynthetic organisms that harbor a rich diversity of associated microbial communities with substantial functions related to host health and defense. Environmental and anthropogenic stressors may disrupt the microbial communities and their metabolic activity, leading to host physiological alterations that negatively affect seaweeds’ performance and survival. Here, the bacterial communities associated with one of the most common seaweed, Ulva laetevirens Areshough, were sampled over a year at three sites of the lagoon of Venice affected by different environmental and anthropogenic stressors. Bacterial communities were characterized through Illumina sequencing of the V4 hypervariable region of 16S rRNA genes. The study demonstrated that the seaweed associated bacterial communities at sites impacted by environmental stressors were host-specific and differed significantly from the less affected site. Furthermore, these communities were significantly distinct from those of the surrounding seawater. The bacterial communities’ composition was significantly correlated with environmental parameters (nutrient concentrations, dissolved oxygen saturation, and pH) across sites. This study showed that several more abundant bacteria on U. laetevirens at stressed sites belonged to taxa related to the host response to the stressors. Overall, environmental parameters and anthropogenic stressors were shown to substantially affect seaweed associated bacterial communities, which reflect the host response to environmental variations.

scholarly journals Cavalier Use of Inferential Statistics Is a Major Source of False and Irreproducible Scientific Findings

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 603
Author(s):  
Leonid Hanin
Keyword(s):  
Sample Size ◽  
Gaussian Approximation ◽  
Statistical Significance ◽  
Statistical Analyses ◽  
Random Sample Size ◽  
P Values ◽  
The Central Limit Theorem ◽  
Fixed Sample ◽  
Large Numbers ◽  
Significance Levels

I uncover previously underappreciated systematic sources of false and irreproducible results in natural, biomedical and social sciences that are rooted in statistical methodology. They include the inevitably occurring deviations from basic assumptions behind statistical analyses and the use of various approximations. I show through a number of examples that (a) arbitrarily small deviations from distributional homogeneity can lead to arbitrarily large deviations in the outcomes of statistical analyses; (b) samples of random size may violate the Law of Large Numbers and thus are generally unsuitable for conventional statistical inference; (c) the same is true, in particular, when random sample size and observations are stochastically dependent; and (d) the use of the Gaussian approximation based on the Central Limit Theorem has dramatic implications for p-values and statistical significance essentially making pursuit of small significance levels and p-values for a fixed sample size meaningless. The latter is proven rigorously in the case of one-sided Z test. This article could serve as a cautionary guidance to scientists and practitioners employing statistical methods in their work.

scholarly journals Quantifying the changes in oxygen extraction fraction and cerebral activity caused by caffeine and acetazolamide

2016 ◽  
Vol 37 (3) ◽  
pp. 825-836 ◽  
Author(s):  
Sagar Buch ◽  
Yongquan Ye ◽  
E Mark Haacke
Keyword(s):  
Oxygen Saturation ◽  
A Priori ◽  
Susceptibility Mapping ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Cerebral Veins ◽  
Blood Oxygen Saturation ◽  
Vascular Reserve ◽  
Extraction Fraction ◽  
Before And After

A quantitative estimate of cerebral blood oxygen saturation is of critical importance in the investigation of cerebrovascular disease. We aimed to measure the change in venous oxygen saturation (Yv) before and after the intake of the vaso-dynamic agents caffeine and acetazolamide with high spatial resolution using susceptibility mapping. Caffeine and acetazolamide were administered on separate days to five healthy volunteers to measure the change in oxygen extraction fraction. The internal streaking artifacts in the susceptibility maps were reduced by giving an initial susceptibility value uniformly to the structure-of-interest, based on a priori information. Using this technique, Yv for normal physiological conditions, post-caffeine and post-acetazolamide was measured inside the internal cerebral veins as YNormal = 69.1 ± 3.3%, YCaffeine = 60.5 ± 2.8%, and YAcet = 79.1 ± 4.0%. This suggests that susceptibility mapping can serve as a sensitive biomarker for measuring reductions in cerebro-vascular reserve through abnormal vascular response. The percentage change in oxygen extraction fraction for caffeine and acetazolamide were found to be +27.0 ± 3.8% and −32.6 ± 2.1%, respectively. Similarly, the relative changes in cerebral blood flow in the presence of caffeine and acetazolamide were found to be −30.3% and + 31.5%, suggesting that the cerebral metabolic rate of oxygen remains stable between normal and challenged brain states for healthy subjects.

scholarly journals Bone Cement Solidifiliation Influence the Limb Alignment and Gap Balance during TKA

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Dongquan Shi ◽  
Xingquan Xu ◽  
Anyun Guo ◽  
Jin Dai ◽  
Zhihong Xu ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Bone Cement ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Statistical Significance ◽  
Mechanical Alignment ◽  
Early Loosening ◽  
Flexion Extension ◽  
Before And After ◽  
Total Knee

Introduction. Mechanical alignment deviation after total knee arthroplasty is a major reason for early loosening of the prosthesis. Achieving optimum cement penetration during fixation of the femoral and tibial component is an essential step in performing a successful total knee arthroplasty. Bone cement is used to solidify the bone and prosthesis. Thickness imbalance of bone cement leads to the deviation of mechanical alignment. To estimate the influence of bone cement, a retrospective study was conducted.Materials and Methods. A total of 36 subjects were studied. All the TKA were performed following the standard surgical protocol for navigated surgery by medial approach with general anaesthesia. Prostheses were fixed by bone cement.Results. We compared the mechanical axis, flexion/extension, and gap balance before and after cementation. All the factors were different compared with those before and after cementation. Internal rotation was reached with statistical significance (P=0.03).Conclusion. Bone cement can influence the mechanical axis, flexion/extension, and gap balance. It also can prompt us to make a change when poor knee kinematics were detected before cementation.

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