scholarly journals Synoptic relationships between surface Chlorophyll-<i>a</i> and diagnostic pigments specific to phytoplankton functional types

2011 ◽  
Vol 8 (2) ◽  
pp. 311-327 ◽  
Author(s):  
T. Hirata ◽  
N. J. Hardman-Mountford ◽  
R. J. W. Brewin ◽  
J. Aiken ◽  
R. Barlow ◽  
...  
Keyword(s):  
Green Algae ◽  
Marine Ecosystem ◽  
Global Scale ◽  
Least Square ◽  
Major Group ◽  
Surface Distribution ◽  
Chl A ◽  
Functional Types ◽  
Total Community ◽  
The Mean

Abstract. Error-quantified, synoptic-scale relationships between chlorophyll-a (Chl-a) and phytoplankton pigment groups at the sea surface are presented. A total of ten pigment groups were considered to represent three Phytoplankton Size Classes (PSCs, micro-, nano- and picoplankton) and seven Phytoplankton Functional Types (PFTs, i.e. diatoms, dinoflagellates, green algae, prymnesiophytes (haptophytes), pico-eukaryotes, prokaryotes and Prochlorococcus sp.). The observed relationships between Chl-a and PSCs/PFTs were well-defined at the global scale to show that a community shift of phytoplankton at the basin and global scales is reflected by a change in Chl-a of the total community. Thus, Chl-a of the total community can be used as an index of not only phytoplankton biomass but also of their community structure. Within these relationships, we also found non-monotonic variations with Chl-a for certain pico-sized phytoplankton (pico-eukaryotes, Prokaryotes and Prochlorococcus sp.) and nano-sized phytoplankton (Green algae, prymnesiophytes). The relationships were quantified with a least-square fitting approach in order to enable an estimation of the PFTs from Chl-a where PFTs are expressed as a percentage of the total Chl-a. The estimated uncertainty of the relationships depends on both PFT and Chl-a concentration. Maximum uncertainty of 31.8% was found for diatoms at Chl-a = 0.49 mg m−3. However, the mean uncertainty of the relationships over all PFTs was 5.9% over the entire Chl-a range observed in situ (0.02 < Chl-a < 4.26 mg m−3). The relationships were applied to SeaWiFS satellite Chl-a data from 1998 to 2009 to show the global climatological fields of the surface distribution of PFTs. Results show that microplankton are present in the mid and high latitudes, constituting only ~10.9% of the entire phytoplankton community in the mean field for 1998–2009, in which diatoms explain ~7.5%. Nanoplankton are ubiquitous throughout the global surface oceans, except the subtropical gyres, constituting ~45.5%, of which prymnesiophytes (haptophytes) are the major group explaining ~31.7% while green algae contribute ~13.9%. Picoplankton are dominant in the subtropical gyres, but constitute ~43.6% globally, of which prokaryotes are the major group explaining ~26.5% (Prochlorococcus sp. explaining 22.8%), while pico-eukaryotes explain ~17.2% and are relatively abundant in the South Pacific. These results may be of use to evaluate global marine ecosystem models.

scholarly journals Synoptic relationships quantified between surface Chlorophyll-<i>a</i> and diagnostic pigments specific to phytoplankton functional types

2010 ◽  
Vol 7 (5) ◽  
pp. 6675-6704
Author(s):  
T. Hirata ◽  
N. J. Hardman-Mountford ◽  
R. J. W. Brewin ◽  
J. Aiken ◽  
R. Barlow ◽  
...  
Keyword(s):  
Green Algae ◽  
Phytoplankton Community ◽  
Marine Ecosystem ◽  
Global Scale ◽  
Least Square ◽  
Surface Distribution ◽  
Functional Types ◽  
Background Population ◽  
Marine Ecosystem Models ◽  
Global Surface

Abstract. Error-quantified, synoptic-scale relationships between chlorophyll-a (Chla) and phytoplankton pigment groups at the sea surface are presented. A total of nine pigment groups were considered to represent nine phytoplankton functional types (PFTs) including microplankton, nanoplankton, picoplankton, diatoms, dinoflagellates, green algae, picoeukaryotes, prokaryotes and Prochlorococcus sp. The observed relationships between Chla and pigment groups were well-defined at the global scale to show that Chla can be used as an index of not only phytoplankton abundance but also community structure; large (micro) phytoplankton monotonically increase as Chla increases, whereas the small (pico) phytoplankton community generally decreases. Within these relationships, we also found non-monotonic variations with Chla for certain pico-plankton (pico-eukaryotes, Prokaryotes and Prochlorococcus sp.) and for Green Algae and nano-sized phytoplankton. The relationships were quantified with a least-square fitting approach in order to estimate the PFTs from Chla alone. The estimated uncertainty of the relationships quantified depends on both phytoplankton types and Chla concentration. Maximum uncertainty over all groups (34.7% Chla) was found from diatom at approximately Chla = 1.07 mg m−3. However, the mean uncertainty of the relationships over all groups was 5.8 [% Chla] over the entire Chla range observed (0.02 < Chla < 6.84 mg m−3). The relationships were applied to SeaWiFS satellite Chla data from 1998 to 2009 to show the global climatological fields of the surface distribution of PFTs. Results show that microplankton are present in the mid and high latitudes, constituting ~9.0 [% Chla] of the phytoplankton community at the global surface, in which diatoms explain ~6.0 [% Chla]. Nanoplankton are ubiquious throught much of the global surface oceans except subtropical gyres, acting as a background population, constituting ~44.2 [% Chla]. Picoplankton are mostly limited in subtropical gyres, constituting ~46.8 [% Chla] globally, in which prokaryotes are the major species explaining 32.3 [% Chla] (prochlorococcus sp. explaining 21.5 [% Chla]), while pico-eukaryotes are notably abundant in the Southern Pacific explaining ~14.5 [% Chla]. These results may be used to constrain or validate global marine ecosystem models.

Understanding the CoVID-19 pandemic Curve through statistical approach (Preprint)

2020 ◽  
Author(s):  
Ibrar Ul Hassan Akhtar
Keyword(s):  
Probability Density ◽  
Change Point ◽  
Statistical Approach ◽  
Sudden Change ◽  
Global Scale ◽  
Change Point Detection ◽  
Segment Length ◽  
Infected Population ◽  
The Mean ◽  
Point Detection

UNSTRUCTURED Current research is an attempt to understand the CoVID-19 pandemic curve through statistical approach of probability density function with associated skewness and kurtosis measures, change point detection and polynomial fitting to estimate infected population along with 30 days projection. The pandemic curve has been explored for above average affected countries, six regions and global scale during 64 days of 22nd January to 24th March, 2020. The global cases infection as well as recovery rate curves remained in the ranged of 0 ‒ 9.89 and 0 ‒ 8.89%, respectively. The confirmed cases probability density curve is high positive skewed and leptokurtic with mean global infected daily population of 6620. The recovered cases showed bimodal positive skewed curve of leptokurtic type with daily recovery of 1708. The change point detection helped to understand the CoVID-19 curve in term of sudden change in term of mean or mean with variance. This pointed out disease curve is consist of three phases and last segment that varies in term of day lengths. The mean with variance based change detection is better in differentiating phases and associated segment length as compared to mean. Global infected population might rise in the range of 0.750 to 4.680 million by 24th April 2020, depending upon the pandemic curve progress beyond 24th March, 2020. Expected most affected countries will be USA, Italy, China, Spain, Germany, France, Switzerland, Iran and UK with at least infected population of over 0.100 million. Infected population polynomial projection errors remained in the range of -78.8 to 49.0%.

scholarly journals Happiness, quality of working life, and job satisfaction among nurses working in emergency departments in Iran

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Somayeh Javanmardnejad ◽  
Razieh Bandari ◽  
Majideh Heravi-Karimooi ◽  
Nahid Rejeh ◽  
Hamid Sharif Nia ◽  
...  
Keyword(s):  
Job Satisfaction ◽  
Emergency Departments ◽  
Economic Status ◽  
Linear Regression Analysis ◽  
Working Life ◽  
Least Square ◽  
Life Questionnaire ◽  
Quality Of Working Life ◽  
The Mean

Abstract Background Nurses have a vital role in the healthcare system. One of the basic steps to increase their happiness is to recognize factors such as job satisfaction and quality of working life. Therefore, the goal of the present study was to examine the relationship between happiness and quality of working life and job satisfaction among nursing personnel. Methods This descriptive study was carried out on 270 hospital nurses who worked in emergency departments in Iran. Nurses were recruited through the census method. Data collection instruments included the Oxford Happiness Inventory (OHI), the Quality of Work Life Questionnaire (QWL), and the Job Satisfaction Questionnaire (JSQ). Data were explored using descriptive statistics, and stepwise multiple linear regression analysis. Results The mean age of participants was 30.1 ± 6.26 years. The mean happiness score was 38.5 ± 16.22, the mean Quality of Working Life (QWL) score was 84.3 ± 17.62, and the mean job satisfaction score was found to be 45.5 ± 13.57); corresponding to moderate levels of attributes. The results obtained from the ordinary least-square (OLS) regression indicated that happiness significantly was associated with economic status and satisfaction with closure (R2: 0.38). Conclusion Overall the current study found that nurses who work in emergency departments did not feel happy. Additionally, the findings suggest that their happiness were associated with their economic status, and closure over their duties.

scholarly journals Admixing Chaff with Straw Increased the Residues Collected without Compromising Machinery Efficiencies

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1766 ◽  
Author(s):  
Alessandro Suardi ◽  
Sergio Saia ◽  
Walter Stefanoni ◽  
Carina Gunnarsson ◽  
Martin Sundberg ◽  
...  
Keyword(s):  
Energy Production ◽  
Dry Weight ◽  
Global Scale ◽  
Unit Weight ◽  
Residual Biomass ◽  
Energy Needs ◽  
The Mean ◽  
Field Efficiency ◽  
The One ◽  
Staple Crop

The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries.

Analysis of the appearance of two-color cotton yarn by the double-channel spinning system

2018 ◽  
Vol 89 (9) ◽  
pp. 1712-1724 ◽  
Author(s):  
Mingrui Guo ◽  
Fengxin Sun ◽  
Lei Wang ◽  
Yuan Xue ◽  
Ruihua Yang ◽  
...  
Keyword(s):  
Weight Ratio ◽  
Fiber Distribution ◽  
Ring Spinning ◽  
Surface Distribution ◽  
Left Hand ◽  
Spun Yarns ◽  
The Mean ◽  
Compact Spinning ◽  
The Right ◽  
Double Channel

The main aim of this paper is to investigate the fiber distribution on the surface of a kind of novel two-color yarn spun by regulating the feeding ratio of two colored rovings on a modified ring spinning frame, which is named the double-channel spinning frame. The surface distribution ratio ( SDR) and the coefficient of variation of surface distribution evenness ( CV sd) of the two colored fiber strands in the yarns was used to quantify the fiber distribution feature along the yarns based on a purpose-made image acquisition device and the corresponding image processing method. The effect of the weight ratio, roving feeding position and spinning method on the mean SDR and CV sd were studied, and the testing results of the Z-twist and S-twist two-color yarns spun by a modified traditional ring spinning frame as well as the yarns spun by a modified compact spinning frame were compared with each other. The fibers of the left-hand roving are more likely to distribute in the surface of Z-twist yarn, while the fibers of the right-hand roving tend to distribute in the surface of S-twist yarn. Four linear fitting equations of the 19.4 tex Z-twist and S-twist two-color ring spun yarns and two-color compact spun yarns were developed to predict the relationships between the mean SDR and weight ratio of two colored fibers.

scholarly journals ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI IMPLEMENTASI ANGGARAN BERBASIS KINERJA

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Kaillin Lalli Randa ◽  
Ida Ayu Purba Riani ◽  
Balthazar Kreuta
Keyword(s):  
Data Analysis ◽  
Organizational Commitment ◽  
Positive Influence ◽  
Least Square ◽  
Ordinary Least Square ◽  
Average Value ◽  
Data Analysis Technique ◽  
Analysis Technique ◽  
Partial Analysis ◽  
The Mean

The purpose of the study was to analyze what factors influence the Performance Based Budget by using a sample of 87 respondents working at the Secretariat of the Papuan People's Representative Council. While the data analysis technique used is the Ordinary least square (OLS) technique. The results of the study are indicated by the calculation of the mean (mean) of 32 item questions and 87 respondents and the result is 137.31. If the value is compared to the criteria that the author has set, then the average value is included in the "Very Good" category. While the results of the partial analysis of organizational commitment (X1) have a significant and positive influence on the performance-based budget of 1,261. Keywords: Performance Based Budget

scholarly journals Is there a trend in cirrus cloud cover due to aircraft traffic?

2005 ◽  
Vol 5 (8) ◽  
pp. 2155-2162 ◽  
Author(s):  
F. Stordal ◽  
G. Myhre ◽  
E. J. G. Stordal ◽  
W. B. Rossow ◽  
D. S. Lee ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Cloud Cover ◽  
Reasonable Agreement ◽  
Global Scale ◽  
Cirrus Cloud ◽  
Positive Trend ◽  
Spatially Correlated ◽  
Upper Limit ◽  
Main Emphasis ◽  
The Mean

Abstract. Trends in cirrus cloud cover have been estimated based on 16 years of data from ISCCP (International Satellite Cloud Climatology Project). The results have been spatially correlated with aircraft density data to determine the changes in cirrus cloud cover due to aircraft traffic. The correlations are only moderate, as many other factors have also contributed to changes in cirrus. Still we regard the results to be indicative of an impact of aircraft on cirrus amount. The main emphasis of our study is on the area covered by the METEOSAT satellite to avoid trends in the ISCCP data resulting from changing satellite viewing geometry. In Europe, which is within the METEOSAT region, we find indications of a trend of about 1-2% cloud cover per decade due to aircraft, in reasonable agreement with previous studies. The positive trend in cirrus in areas of high aircraft traffic contrasts with a general negative trend in cirrus. Extrapolation in time to cover the entire period of aircraft operations and in space to cover the global scale yields a mean estimate of 0.03 Wm-2 (lower limit 0.01, upper limit 0.08 Wm-2) for the radiative forcing due to aircraft induced cirrus. The mean is close to the value given by IPCC (1999) as an upper limit.

scholarly journals Oestrogen levels in serum and urine of premenopausal women eating low and high amounts of meat

2013 ◽  
Vol 17 (9) ◽  
pp. 2087-2093 ◽  
Author(s):  
Brook E Harmon ◽  
Yukiko Morimoto ◽  
Fanchon Beckford ◽  
Adrian A Franke ◽  
Frank Z Stanczyk ◽  
...  
Keyword(s):  
Mixed Models ◽  
Repeated Measures ◽  
Premenopausal Women ◽  
Least Square ◽  
Serum Samples ◽  
Meat Eating ◽  
Three Samples ◽  
Blood And Urine Samples ◽  
The Mean ◽  
Serum And Urine

AbstractObjectiveBased on the hypothesis that high-meat diets may increase breast cancer risk through hormonal pathways, the present analysis compared oestrogens in serum and urine by meat-eating status.DesignIntervention with repeated measures.SettingTwo randomized soya trials (BEAN1 and BEAN2) among premenopausal healthy women.SubjectsBEAN1 participants completed seven unannounced 24 h dietary recalls and donated five blood and urine samples over 2 years. BEAN2 women provided seven recalls and three samples over 13 months. Serum samples were analysed for oestrone (E1) and oestradiol (E2) using RIA. Nine oestrogen metabolites were measured in urine by LC–MS. Semi-vegetarians included women who reported consuming <30 g of red meat, poultry and fish daily, and pescatarians those who reported consuming <20 g of meat/poultry but >10 g of fish daily. All other women were classified as non-vegetarians. We applied mixed models to compute least-square means by vegetarian status adjusted for potential confounders.ResultsThe mean age of the 272 participants was 41·9 (sd 4·5) years. Serum E1 (85 v. 100 pg/ml, P = 0·04) and E2 (140 v. 154 pg/ml, P = 0·04) levels were lower in the thirty-seven semi-vegetarians than in the 235 non-vegetarians. The sum of the nine urinary oestrogen metabolites (183 v. 200 pmol/mg creatinine, P = 0·27) and the proportions of individual oestrogens and pathways did not differ by meat-eating status. Restricting the models to the samples collected during the luteal phase strengthened the associations.ConclusionsGiven the limitations of the study, the lower levels of serum oestrogens in semi-vegetarians than non-vegetarians need confirmation in larger populations.

Wave induced turbulence effect on oceanic biogeochemistry and study of ocean color response to changing wave climate

2021 ◽  
Author(s):  
Chinglen Meetei Tensubam ◽  
Alexander V. Babanin
Keyword(s):  
Net Primary Productivity ◽  
Mixed Layer Depth ◽  
Marine Ecosystem ◽  
Ocean Color ◽  
Ocean Waves ◽  
Wave Climate ◽  
Upper Ocean ◽  
P Value ◽  
Chl A ◽  
Wave Induced

&lt;p&gt;The role of surface ocean waves becomes substantial in the upper ocean layer mixing. Due to turbulence induced by the surface waves (both broken and unbroken waves), the upper ocean mixing is enhanced, and important upper ocean parameters are affected such as lowering of sea surface temperature (SST), deepening of mixed layer depth (MLD) and most interestingly, the changes in oceanic biogeochemistry. The main objective of this study is to analyze the effect of wave induced turbulence on oceanic biogeochemistry such as the supply and distribution of nutrients to tiny plants in the ocean called phytoplanktons, and how it affects their concentrations. Marine phytoplanktons formed the basis of marine ecosystem which accounts for about 45 percent of global net primary productivity and play an important part in global carbon cycle. The population of phytoplanktons depends mainly on nutrients (both micro and macro), availability of sunlight and grazing organisms. For this study, we use global coupled ocean-sea ice model ACCESS-OM2 with biogeochemical module called WOMBAT to estimate the effect of wave induced turbulence and study the difference between &amp;#8216;with waves&amp;#8217; and &amp;#8216;without waves&amp;#8217; effect on oceanic biogeochemistry. The same effect of wave induced turbulence on oceanic biogeochemistry are also studied by incorporating the change in wave climate such as increase in significant wave height and wind speed. From the investigation of merged satellite ocean color data from ESA&amp;#8217;s GlobColour project for the period of 23 years between 1997 and 2019, it was found that chlorophyll-a (Chl-a, an index of phytoplankton biomass) concentration showed increasing trend of 0.015 mg/m3 globally and 0.062 mg/m3 in the Southern Ocean (SO) for the study period with p-value less than 0.01. It was also found that most of the increasing trends are shown spatially in the open ocean and decreasing trend in the coastal regions during the study period.&lt;/p&gt;

Water Quality Estimation Using Combined Water Chemistry and Field Spectroscopy in the Shenandoah River, Virginia

2016 ◽  
Vol 7 (2) ◽  
pp. 14-37 ◽  
Author(s):  
Mbongowo J. Mbuh ◽  
Paul R. Houser ◽  
Ako Heidari
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Spatial Dynamics ◽  
Strong Correlations ◽  
Colored Dissolved Organic Matter ◽  
Quality Estimation ◽  
Chl A ◽  
Total Phosphorous ◽  
The Mean ◽  
Band Combinations

This study investigated the spatial dynamics of water quality across the Shenandoah River basin using spectroscopy and chemometrics to estimate chlorophyll (Chl), colored dissolved organic matter (CDOM) and turbidity using three band combinations and nutrients (total nitrogen and total phosphorous) in the Shenandoah River. The mean Chl a concentration for 555 nm, 560 nm and 640 nm were; 0.31 µg/l, 0.33 µg/l, and 0.51 µg/l respectively. Chlorophyll a showed strong correlations at band 640 (r = 0.92). The bands centered at 670/490 were the best in predicting CDOM and turbidity in the Shenandoah River Basin with an r2 = 0.56. Chemometrics analysis show that total phosphorous, nitrogen and turbidity can be predicted between 450 to 555nm and 670 to 710 nm, the range of wavelengths which indicated better predictability for spectroscopic analysis. The resultant concentration is used to develop predictive models to determine sensitive spectral variables for nitrogen, phosphorous, Chl-a, and CDOM.

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