Maiasaura, a model organism for extinct vertebrate population biology: a large sample statistical assessment of growth dynamics and survivorship

Paleobiology ◽  
2015 ◽  
Vol 41 (4) ◽  
pp. 503-527 ◽  
Author(s):  
Holly N. Woodward ◽  
Elizabeth A. Freedman Fowler ◽  
James O. Farlow ◽  
John R. Horner
Keyword(s):  
Mortality Rate ◽  
Population Biology ◽  
Skeletal Maturity ◽  
Model Organism ◽  
Growth Dynamics ◽  
Small Sample ◽  
Peak Performance ◽  
First Year ◽  
Large Sample ◽  
Fossil Records

AbstractFossil bone microanalyses reveal the ontogenetic histories of extinct tetrapods, but incomplete fossil records often result in small sample sets lacking statistical strength. In contrast, a histological sample of 50 tibiae of the hadrosaurid dinosaurMaiasaura peeblesorumallows predictions of annual growth and ecological interpretations based on more histologic data than any previous large sample study. Tibia length correlates well (R2>0.9) with diaphyseal circumference, cortical area, and bone wall thickness, thereby allowing longitudinal predictions of annual body size increases based on growth mark circumference measurements. With an avian level apposition rate of 86.4 μm/day,Maiasauraachieved over half of asymptotic tibia diaphyseal circumference within its first year. Mortality rate for the first year was 89.9% but a seven year period of peak performance followed, when survivorship (mean mortality rate=12.7%) was highest. During the third year of life,Maiasauraattained 36% (x=1260 kg) of asymptotic body mass, growth rate was decelerating (18.2 μm/day), cortical vascular orientation changed, and mortality rate briefly increased. These transitions may indicate onset of sexual maturity and corresponding reallocation of resources to reproduction. Skeletal maturity and senescence occurred after 8 years, at which point the mean mortality rate increased to 44.4%. Compared withAlligator, an extant relative,Maiasauraexhibits rapid cortical increase early in ontogeny, whileAlligatorcortical growth is much lower and protracted throughout ontogeny. Our life history synthesis ofMaiasaurautilizes the largest histological sample size for any extinct tetrapod species thus far, demonstrating how large sample microanalyses strengthen paleobiological interpretations.

Estimating the mortality rate of humpback whale calves in the central North Pacific Ocean

2001 ◽  
Vol 79 (4) ◽  
pp. 589-600 ◽  
Author(s):  
Christine M Gabriele ◽  
Janice M Straley ◽  
Sally A Mizroch ◽  
C Scott Baker ◽  
Alison S Craig ◽  
...  
Keyword(s):  
Mortality Rate ◽  
North Pacific ◽  
Small Sample Size ◽  
North Pacific Ocean ◽  
Humpback Whale ◽  
Small Sample ◽  
Humpback Whales ◽  
First Year ◽  
Robust Estimate ◽  
Calf Mortality

Sighting histories of individually identified female humpback whales (Megaptera novaeangliae) in their winter and summer ranges were used to investigate mortality of North Pacific humpback whale calves. We compiled records collected between 1979 and 1995 by eight independent research groups, which yielded 29 cases where 25 different mothers sighted in Hawai'i were identified later the same year in Alaska. In 7 of 29 cases, a calf sighted with its mother in Hawai'i was missing from its mother's Alaska sighting(s). After investigating many factors, we determined that the largest potential bias would occur in late-autumn observations, when calf absences might indicate weaning or temporary mother–calf separation rather than calf mortality. Our minimal and most robust estimate excluded all mortalities and survivals based on sightings of the mother after October 31; 3 of 20 cases or 0.150 (95% confidence intervals (CI) = 0.032, 0.378). The maximal calf mortality rate, derived from all the available data, was 7 of 29 cases or 0.241 (95% CI = 0.103, 0.434). An intermediate estimate that excluded all cases based on single Alaska sightings and omitted late-season sightings (2 of 11 cases or 0.182; 95% CI = 0.023, 0.518) is perhaps closest to the actual first-year mortality rate for humpback whale calves, although it is compromised by its small sample size. Our results demonstrate both the value and the limitations of using longitudinal data to determine the life-history parameters that are essential for documenting the recovery of endangered populations.

scholarly journals High heterogeneity undermines generalization of differential expression results in RNA-Seq analysis

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Weitong Cui ◽  
Huaru Xue ◽  
Lei Wei ◽  
Jinghua Jin ◽  
Xuewen Tian ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Expression ◽  
Small Sample ◽  
Differentially Expressed ◽  
Cancer Type ◽  
Rna Seq ◽  
Sample Sizes ◽  
Large Sample ◽  
Expression Levels ◽  
Gene Expression Levels

Abstract Background RNA sequencing (RNA-Seq) has been widely applied in oncology for monitoring transcriptome changes. However, the emerging problem that high variation of gene expression levels caused by tumor heterogeneity may affect the reproducibility of differential expression (DE) results has rarely been studied. Here, we investigated the reproducibility of DE results for any given number of biological replicates between 3 and 24 and explored why a great many differentially expressed genes (DEGs) were not reproducible. Results Our findings demonstrate that poor reproducibility of DE results exists not only for small sample sizes, but also for relatively large sample sizes. Quite a few of the DEGs detected are specific to the samples in use, rather than genuinely differentially expressed under different conditions. Poor reproducibility of DE results is mainly caused by high variation of gene expression levels for the same gene in different samples. Even though biological variation may account for much of the high variation of gene expression levels, the effect of outlier count data also needs to be treated seriously, as outlier data severely interfere with DE analysis. Conclusions High heterogeneity exists not only in tumor tissue samples of each cancer type studied, but also in normal samples. High heterogeneity leads to poor reproducibility of DEGs, undermining generalization of differential expression results. Therefore, it is necessary to use large sample sizes (at least 10 if possible) in RNA-Seq experimental designs to reduce the impact of biological variability and DE results should be interpreted cautiously unless soundly validated.

Patients With Idiopathic Pulmonary Fibrosis Admitted to the ICU With Acute Respiratory Failure—A Reevaluation of the Risk Factors and Outcomes

2021 ◽  
pp. 088506662198924
Author(s):  
Matthew Schrader ◽  
Matheni Sathananthan ◽  
Niranjan Jeganathan
Keyword(s):  
Risk Factors ◽  
Respiratory Failure ◽  
Mortality Rate ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Acute Respiratory Failure ◽  
Small Sample ◽  
Apache Score ◽  
Non Invasive ◽  
Organ Failures

Introduction: Idiopathic pulmonary fibrosis (IPF) patients admitted to the ICU with acute respiratory failure (ARF) are known to have a poor prognosis. However, the majority of the studies published to date are older and had small sample sizes. Given the advances in ICU care since the publication of these studies, we sought to reevaluate the outcomes and risk factors associated with mortality in these patients. Methods: Retrospective study using a large multi-center ICU database. We identified 411 unique patients with IPF admitted with ARF between 2014-2015. Results: Of all IPF patients admitted to the ICU with ARF, 81.3% required mechanical ventilation (MV): 48.9% invasive and 32.4% non-invasive alone. The hospital mortality rate was 34.5% for all patients; 48.8% in patients requiring invasive MV, 21.8% in those requiring non-invasive MV and 19.5% with no MV. In multiple regression analyses, age, APACHE score, invasive MV, and hyponatremia at admission were associated with increased mortality whereas post-op status was associated with lower mortality. In patients requiring invasive MV, baseline PaO2/FiO2 ratio was also predictive of mortality. Non-pulmonary organ failures were present in less than 20% of the patients. Conclusions: Although the overall mortality rate for IPF patients admitted to the ICU with ARF has improved, the mortality rates for patients requiring invasive MV remains high at approximately 50%. Older age, high APACHE score, and low baseline PaO2/FiO2 ratio are factors predictive of increased mortality in this population.

Overconfidence of vocational education students when entering higher education

2015 ◽  
Vol 57 (4) ◽  
pp. 429-447 ◽  
Author(s):  
Mark P. Bowden ◽  
Subhash Abhayawansa ◽  
John Bahtsevanoglou
Keyword(s):  
Higher Education ◽  
Self Efficacy ◽  
Further Education ◽  
Small Sample ◽  
First Year ◽  
Education Students ◽  
Content Type ◽  
The Relationship ◽  
Practical Implications

Purpose – There is evidence that students who attend Technical and Further Education (TAFE) prior to entering higher education underperform in their first year of study. The purpose of this paper is to examine the role of self-efficacy in understanding the performance of students who completed TAFE in the previous year in a first year subject of microeconomics in a dual sector university in Melbourne, Australia. Design/methodology/approach – The study utilises data collected by surveys of 151 students. Findings – A student’s self-efficacy is positively associated with their marks in a first year subject of microeconomics. However, the relationship between final marks and self-efficacy is negative for those students who attended TAFE in the previous year suggesting that they suffer from the problem of overconfidence. When holding self-efficacy constant, using econometric techniques, TAFE attendance is found to be positively related to final marks. Research limitations/implications – The findings are exploratory (based on a small sample) and lead to a need to conduct cross institutional studies. Practical implications – The research points to the need for early interventions so that TAFE students perform well in their first year of higher education. It also points to potential issues in the development of Victorian Certificate of Applied Learning (VCAL) programs. Originality/value – To the best of the authors’ knowledge, this is the first paper to examine the inter-related impact of attendance at TAFE in the previous year and self-efficacy on the subsequent academic performance of TAFE students.

Clinical outcomes of cancer patients with COVID-19: A systematic review and meta-analysis.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e18600-e18600
Author(s):  
Maryam Alasfour ◽  
Salman Alawadi ◽  
Malak AlMojel ◽  
Philippos Apolinario Costa ◽  
Priscila Barreto Coelho ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Cancer Patients ◽  
Clinical Outcomes ◽  
Meta Analysis ◽  
Small Sample ◽  
Prediction Intervals ◽  
Invasive Ventilation ◽  
Newcastle Ottawa Scale ◽  
Small Sample Sizes ◽  
Meta Analyses

e18600 Background: Patients with coronavirus disease 2019 (COVID-19) and cancer have worse clinical outcomes compared to those without cancer. Primary studies have examined this population, but most had small sample sizes and conflicting results. Prior meta-analyses exclude most US and European data or only examine mortality. The present meta-analysis evaluates the prevalence of several clinical outcomes in cancer patients with COVID-19, including new emerging data from Europe and the US. Methods: A systematic search of PubMED, medRxiv, JMIR and Embase by two independent investigators included peer-reviewed papers and preprints up to July 8, 2020. The primary outcome was mortality. Other outcomes were ICU and non-ICU admission, mild, moderate and severe complications, ARDS, invasive ventilation, stable, and clinically improved rates. Study quality was assessed through the Newcastle–Ottawa scale. Random effects model was used to derive prevalence rates, their 95% confidence intervals (CI) and 95% prediction intervals (PI). Results: Thirty-four studies (N = 4,371) were included in the analysis. The mortality prevalence rate was 25.2% (95% CI: 21.1–29.7; 95% PI: 9.8-51.1; I 2 = 85.4), with 11.9% ICU admissions (95% CI: 9.2-15.4; 95% PI: 4.3-28.9; I 2= 77.8) and 25.2% clinically stable (95% CI: 21.1-29.7; 95% PI: 9.8-51.1; I 2 = 85.4). Furthermore, 42.5% developed severe complications (95% CI: 30.4-55.7; 95% PI: 8.2-85.9; I 2 = 94.3), with 22.7% developing ARDS (95% CI: 15.4-32.2; 95% PI: 5.8-58.6; I 2 = 82.4), and 11.3% needing invasive ventilation (95% CI: 6.7-18.4; 95% PI: 2.3-41.1; I 2 = 79.8). Post-follow up, 49% clinically improved (95% CI: 35.6-62.6; 95% PI: 9.8-89.4; I 2 = 92.5). All outcomes had large I 2 , suggesting high levels of heterogeneity among studies, and wide PIs indicating high variability within outcomes. Despite this variability, the mortality rate in cancer patients with COVID-19, even at the lower end of the PI (9.8%), is higher than the 2% mortality rate of the non-cancer with COVID-19 population, but not as high as what other meta-analyses conclude, which is around 25%. Conclusions: Patients with cancer who develop COVID-19 have a higher probability of mortality compared to the general population with COVID-19, but possibly not as high as previous studies have shown. A large proportion of them developed severe complications, but a larger proportion recovered. Prevalence of mortality and other outcomes published in prior meta-analyses did not report prediction intervals, which compromises the clinical utilization of such results.

scholarly journals ALCAPA: The Al Capone of coronary artery anomalies

2012 ◽  
Vol 16 (3) ◽  
pp. 100-101 ◽  
Author(s):  
Farzanah Ismail
Keyword(s):  
Coronary Artery ◽  
Mortality Rate ◽  
Left Coronary Artery ◽  
First Year ◽  
Coronary Artery Anomalies ◽  
Perfusion System ◽  
Anomalous Left Coronary Artery ◽  
First Year Of Life ◽  
Anomalous Left Coronary ◽  
Artery Perfusion

Anomalous left coronary artery originating from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly that presents with myocardial ischaemia or infarction and/or cardiac failure in infants. It is associated with a mortality rate of 90% within the first year of life. Surgical correction to re-establish a two-coronary artery perfusion system is the treatment of choice, once patients are medically stable.

scholarly journals Population Structure and Life Table of Dog Conch (Strombus turturella) in Bangka Belitung Islands, Indonesia [Struktur Populasi dan Tabel Hidup Siput Gonggong (Strombus turturella) di Kepulauan Bangka Belitung, Indonesia]

2019 ◽  
Vol 11 (2) ◽  
pp. 72
Author(s):  
Okto Supratman ◽  
Tati Suryati Syamsudin
Keyword(s):  
Mortality Rate ◽  
Life Table ◽  
High Mortality ◽  
Economic Value ◽  
Age Groups ◽  
Time Estimation ◽  
First Year ◽  
Age Group ◽  
Growth Coefficient ◽  
Recruitment Time

AbstractDog Conch (Strombus turturella) has an essential economic value in Bangka Belitung Islands. Allegedly, the population of Dog Conch is decreasing due to overexploitation. The purpose of this study is to provide information related to the distribution of long frequency, growth pattern, age group, recruitment time estimation and life table of Dog Conch. This research took place on the coast of Tukak Village and Anak Air Island, Bangka Belitung Islands. Samples of Dog Conch were taken using 3x3 m2 square. The shell length of Dog Conch found ranged between 18.18 to 77.49 mm, consisting of three age groups. Asymptotic length value (L∞), growth coefficient (K) and theoretical age on zero-length (t0) were 83.94 mm, 0.79/year and -0.152 sequentially. In the first year, Dog Conch grows to 50.18 mm and slows down when it grows older until it is 13 years old. The proportion of high mortality rate was at 1 to 2 years old and 3 to 4 years old or in adult individuals, while the highest life expectancy rate was in the age group of 0-1-year old or young individuals. It indicated that the high mortality rate was in the group in which people use to consume or sell in the marketsAbstrakSiput gonggong (Strombus turturella) memiliki nilai ekonomis penting di Kepulauan Bangka Belitung. Diduga populasi siput gonggong semakin menurun akibat dari eksploitasi berlebihan. Tujuan penelitian ini adalah untuk memberikan informasi terkait distribusi frekuensi panjang, pola pertumbuhan, kelompok umur, estimasi waktu rekruitmen dan tabel hidup siput gonggong. Lokasi penelitian berada di Pesisir Desa Tukak dan Pulau Anak Air, Kepulauan Bangka Belitung.Pengambilan sampel siput gonggong dilakukan dengan menggunakan kuadrat 3x3 m2. Panjang cangkang siput gonggong yang ditemukan berkisar antara 18.18 s.d 77.49 mm yang terdiri atas 3 kelompok umur. Nilai panjang asymptotic (L∞), koefisien pertumbuhan (K) dan umur teoritis ketika panjang sama dengan nol (t0) adalah 83.94 mm, 0.79/tahun dan -0.152 secara berurutan. Pada tahun pertama siput gonggong mengalami pertumbuhan, mencapai 50.18 mm dan melambat ketika umur semakin tua hingga umur 13 tahun. Proporsi laju kematian tinggi terdapat pada umur 1 s.d 2 tahun dan 3 s.d 4 tahun atau pada individu dewasa, sedangkan nilai harapan hidup tertinggi terdapat pada kelompok umur 0-1 tahun atau individu muda. Hal ini menunjukkan bahwa kematian tertinggi terdapat pada kelompok umur yang telah diambil oleh masyarakat untuk dikonsumsi dan dijual ke pasaran.

scholarly journals Pre-university informal engagement with mathematical activities and the decision to study mathematics at university

2020 ◽  
Vol 18 (3) ◽  
pp. 10-22
Author(s):  
Katie Steckles ◽  
Peter Rowlett ◽  
Angharad Ugonna
Keyword(s):  
Social Media ◽  
Career Choice ◽  
Small Sample ◽  
First Year ◽  
Mathematical Activity ◽  
Online Videos ◽  
High Level ◽  
Watching Tv ◽  
Mathematical Activities

A survey was created to investigate the experiences of mathematics undergraduates with informal mathematical activity prior to starting university, and links these with the decision to study mathematics. A questionnaire was completed by a small sample of first-year undergraduates at two UK universities. Generally, incoming undergraduates are shown to have a high level of enjoyment of mathematics and engagement with informal mathematical activity. Popular activities included mathematical puzzles and games, and online videos about maths. Students were often engaged with family or via social media, playing computer, tablet or phone games, watching TV game shows with mathematical aspects and participating in organised competitions. Only around half engaged via talks or workshops organised through school and watching more structured documentaries or videos of lectures. Few participated in organised clubs. It seems there was greater engagement with ‘fun’ aspects of mathematics than with activities which demonstrate mathematics linked to career choice. The link to goals of outreach and similar initiatives is discussed, with further research indicated.

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