scholarly journals δ13C values of wood and Charcoal Reveal Broad Isotopic ranges at the base of the Food Web

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 2003-2017 ◽  
Author(s):  
Bente Philippsen ◽  
Jesper Olsen ◽  
Søren A Sørensen ◽  
Bjørnar Måge
Keyword(s):  
Time Dependence ◽  
Food Web ◽  
Food Chain ◽  
Species Range ◽  
Small Study ◽  
Individual Species ◽  
Δ13c Values ◽  
The Mean ◽  
High Degree

ABSTRACTThe aim of this study is to investigate the range, the degree of variability, and a possible time or species dependence of wood and charcoal δ13C values within one small study area. To achieve this, we used δ13C and 14C determinations of more than 400 archaeological samples from a ca. 300 ha area in Denmark, spanning 5000 years and covering several different species. The δ13C values of the wood and charcoal range from −32.8‰ to −21.2‰. We found no time-dependence of wood and charcoal δ13C values, neither in general nor within one species. The mean δ13C of all wood samples is −28.5‰, while the means of individual species range from −30.6‰ to −26.3‰. The mean of all charcoal samples is −25.7‰, with the means of individual species ranging from −28.1‰ to −24.3‰. The wood δ13C values can be used to infer the possible range of plant δ13C values, which otherwise are not available. They imply that a high degree of variability can be expected at the base of the food chain. This is relevant for palaeodietary studies that rely on the measurement of baseline isotope values.

scholarly journals Persistence and stability of interacting species in response to climate warming: The role of trophic structure

2020 ◽  
Author(s):  
Taranjot Kaur ◽  
Partha Sharathi Dutta
Keyword(s):  
Food Web ◽  
Climate Warming ◽  
Food Chain ◽  
Trophic Structure ◽  
Community Dynamics ◽  
Threshold Temperature ◽  
Individual Species ◽  
Past Century ◽  
Interacting Species ◽  
Species Dynamics

AbstractOver the past century, the Earth has experienced roughly 0.4–0.8°C rise in the average temperature and which is projected to increase between 1.4–5.8°C by the year 2100. The increase in the Earth’s temperature directly influences physiological traits of individual species in ecosystems. However, the effect of these changes in community dynamics, so far, remains relatively unknown. Here we show that the consequences of warming (i.e., increase in the global mean temperature) on the interacting species persistence or extinction are correlated with their trophic complexity and community structure. In particular, we investigate different nonlinear bioenergetic tri-trophic food web modules, commonly observed in nature, in the order of increasing trophic complexity; a food chain, a diamond food web and an omnivorous interaction. We find that at low temperatures, warming can destabilize the species dynamics in the food chain as well as the diamond food web, but it has no such effect on the trophic structure that involves omnivory. In the diamond food web, our results indicate that warming does not support top-down control induced co-existence of intermediate species. However, in all the trophic structures warming can destabilize species up to a threshold temperature. Beyond the threshold temperature, warming stabilizes species dynamics at the cost of the extinction of higher trophic species. We demonstrate the robustness of our results when a few system parameters are varied together with the temperature. Overall, our study suggests that variations in the trophic complexity of simple food web modules can influence the effects of climate warming on species dynamics.

scholarly journals Perception of the Online Learning Environment of Nursing Students in Slovenia: Validation of the DREEM Questionnaire

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 998
Author(s):  
Lucija Gosak ◽  
Nino Fijačko ◽  
Carolina Chabrera ◽  
Esther Cabrera ◽  
Gregor Štiglic
Keyword(s):  
Nursing Students ◽  
Nursing Student ◽  
Student Perception ◽  
Psychometric Testing ◽  
Educational Environment ◽  
Educational Process ◽  
Survey Questionnaire ◽  
Self Perception ◽  
The Mean ◽  
High Degree

At the time of the outbreak of the coronavirus pandemic, several measures were in place to limit the spread of the virus, such as lockdown and restriction of social contacts. Many colleges thus had to shift their education from personal to online form overnight. The educational environment itself has a significant influence on students’ learning outcomes, knowledge, and satisfaction. This study aims to validate the tool for assessing the educational environment in the Slovenian nursing student population. To assess the educational environment, we used the DREEM tool distributed among nursing students using an online platform. First, we translated the survey questionnaire from English into Slovenian using the reverse translation technique. We also validated the DREEM survey questionnaire. We performed psychometric testing and content validation. I-CVI and S-CVI are at an acceptable level. A high degree of internal consistency was present, as Cronbach’s alpha was 0.951. The questionnaire was completed by 174 participants, of whom 30 were men and 143 were women. One person did not define gender. The mean age of students was 21.1 years (SD = 3.96). The mean DREEM score was 122.2. The mean grade of student perception of learning was 58.54%, student perception of teachers was 65.68%, student academic self-perception was 61.88%, student perception of the atmosphere was 60.63%, and social self-perception of students was 58.93%. Although coronavirus has affected the educational process, students still perceive the educational environment as positive. Nevertheless, there is still room for improvement in all assessed areas.

scholarly journals Food Web Structure and Trophic Interactions Revealed by Stable Isotope Analysis in the Midstream of the Chishui River, a Tributary of the Yangtze River, China

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 195
Author(s):  
Qiang Qin ◽  
Fubin Zhang ◽  
Fei Liu ◽  
Chunling Wang ◽  
Huanzhang Liu
Keyword(s):  
Stable Isotope ◽  
Carbon Source ◽  
Food Web ◽  
Food Chain ◽  
Yangtze River ◽  
Trophic Niche ◽  
The Yangtze River ◽  
Food Chain Length ◽  
Trophic Pathways ◽  
Chishui River

Understanding energy flow and nutrient pathways is crucial to reveal the dynamics and functions of riverine ecosystems and develop appropriate conservation strategies. In this study, we utilized stable isotopes of δ13C and δ15N to examine the fundamental characteristics of trophic position, trophic niche, and carbon source for the food web in the midstream of the Chishui River, a tributary to the Yangtze River. Our results showed that stable isotope signatures among different sorts of basal resources and consumers were significantly distinguishable and that the food chain consisted of four trophic levels, indicating the multiple trophic pathways and long food chain length here. The trophic guilds of fish were classified into four categories, in which herbivorous and carnivorous fish showed greater trophic diversity and omnivorous fish had higher trophic redundancy, which meant that there was a stable trophic niche structure in the study area. Phytoplankton and periphyton presented the largest contributions to consumers, indicating that autochthonous productivity was the dominant carbon source in the midstream of the Chishui River. Since the Chishui River is still in a natural condition without any dam constructions, the autochthonous productivity, stable trophic niche structure, multiple trophic pathways and long food chain length found here demonstrate its high conservation value. Therefore, the strategy to refrain from damming on this river should persist into the future.

scholarly journals Assessment of costs and insurance policies for referral treatment of equine colic

2019 ◽  
Vol 185 (16) ◽  
pp. 508-508 ◽  
Author(s):  
Isobel Barker ◽  
Sarah L Freeman
Keyword(s):  
Surgical Treatment ◽  
Insurance Companies ◽  
Insurance Policies ◽  
Insurance Cover ◽  
Survey Costs ◽  
The Mean ◽  
High Degree ◽  
Mean Cost ◽  
Monthly Premium ◽  
Equine Colic

Colic is the most common emergency problem in horses. The aims of this study were to survey costs of different referral treatments and to review insurance policies relevant to horses with colic. Data were collected retrospectively from nine equine hospitals for case costs, categorised into four different outcomes: admitted and euthanased; euthanased during or immediately after surgery; medical treatment and survived more than 24 hours; and surgical treatment and survived more than 24 hours. Data from five UK equine insurance companies were extracted and analysed using a standardised case example. Costs were obtained for 108 cases. The mean cost for horses admitted and euthanased was £873.89 (range £459.72–£1471.51), and for surgical treatment and survival more than 24 hours was £6437.80 (range £3178.87–£9100.00). Insurance cover for veterinary fees ranged from £5000 to £7500, and monthly premium rates for a standardised case ranged from £27.06 to £47.06. The terms and conditions for the insurance policies ranged in length from 2098 to 17,701 words; Flesch Kincaid Reading Ease scores ranged from 21.6 to 57.7, indicating a high degree of complexity and low readability. This study highlights the complexity and challenges for decision-making in critical cases of colic.

Responses of the bovine teat to machine milking: measurement of changes in thickness of the teat apex

1988 ◽  
Vol 55 (3) ◽  
pp. 331-338 ◽  
Author(s):  
Jörn Hamann ◽  
Graeme A. Mein
Keyword(s):  
Positive Pressure ◽  
Vacuum Level ◽  
Machine Milking ◽  
Before And After ◽  
The Mean ◽  
High Degree

SummaryChanges in the teat apex before and after different milking treatments were measured with a spring-loaded caliper device known as a cutimeter which could detect changes in thickness of the tissues of the teat end, presumably due to congestion and/or oedema, with a high degree of accuracy (± 2%) and repeatability (r = 0·99). Teat end thickness increased with increasing vacuum level. The mean increase immediately after milking with a conventional cluster was 2% for 24 teats milked at 30 kPa, 8% at 50 kPa and 21% at 70 kPa. At these vacuum levels, the mean increases for the same teats milked with an unconventional (PKME) teatcup were 10, 18 and 25% respectively. Cyclic application of 35 kPa positive pressure to the pulsation chamber of a conventional teatcup operating at 50 kPa reduced teat end thickness by 8% compared with the mean premilking value. Although most teats returned to within ± 2% of their premilking thickness values by 1 h after milking, differences were apparent between different milking systems for up to 4 h postmilking.

Determination of Sample Size in Service Inspection

1997 ◽  
Vol 119 (1) ◽  
pp. 57-60
Author(s):  
S. Qin ◽  
G. E. O. Widera
Keyword(s):  
Sample Size ◽  
Large Volume ◽  
Analysis Method ◽  
Degree Of Confidence ◽  
Impossible Task ◽  
The Mean ◽  
High Degree ◽  
Service Inspection ◽  
False Rejection

When performing inservice inspection on a large volume of identical components, it becomes an almost impossible task to inspect all those in which defects may exist, even if their failure probabilities are known. As a result, an appropriate sample size needs to be determined when setting up an inspection program. In this paper, a probabilistic analysis method is employed to solve this problem. It is assumed that the characteristic data of components has a certain distribution which can be taken as known when the mean and standard deviations of serviceable and defective sets of components are estimated. The sample size can then be determined within an acceptable assigned error range. In this way, both false rejection and acceptance can be avoided with a high degree of confidence.

scholarly journals Glaucoma characteristics evaluation in myopia – A clinical study

2021 ◽  
Vol 7 (2) ◽  
pp. 195-199
Author(s):  
Helen Rosita J ◽  
Gnanaselvan J ◽  
Amudhavadivu S ◽  
Anna Kurian Mullasseril
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
High Myopia ◽  
Intra Ocular Pressure ◽  
Significant Difference ◽  
Long Term Follow Up ◽  
Ocular Pressure ◽  
The Mean ◽  
One Year ◽  
High Degree

Glaucoma is the leading cause of irreversible blindness, one of the risk factor recognised being high myopia. Intra ocular pressure may be normal in myopic patients, with optic nerve head glaucoma characteristics. Eye ball elongation and optic nerve head tilting may be present in patients with high myopia that will represent field defects mimicking glaucoma. Treating patients with myopia having suspected aspects of glaucoma may be a challenge but even more challenging is the diagnosis of glaucoma in myopic patients.: To evaluate the association of glaucoma features with myopia. To create the awareness regarding the long term follow up.: Patients in the age group of 15 to 45 years who had attended our institution over a period of one year who fulfilled the inclusion and exclusion criteria were subjected for this study. Fifty four patients who were diagnosed to have moderate or high degree myopia were selected for this analytical study. They were subjected to vision, ocular examination, tonometry and results obtained were analysed.: In our study moderate myopes constituted 55.5% and high myopes were 44.5%. The mean Intra ocular pressure and the mean corrected Intra ocular pressure in high myopes were observed to be higher than in moderate myopia. It was observed that higher prevalence of glaucoma was observed in high myopes.: There is a clinically as well as statistically significant difference between mean Intra ocular pressure and mean corrected Intra ocular pressure. So mean corrected Intra ocular pressure should be measured .From our study, there is a clear indication that there is increased prevalence of glaucoma in high myopes.

scholarly journals Food-web modification in the eastern Gulf of Finland after invasion of Marenzelleria arctia (Spionidae, Polychaeta)

NeoBiota ◽  
2021 ◽  
Vol 66 ◽  
pp. 75-94
Author(s):  
Sergey Golubkov ◽  
Alexei Tiunov ◽  
Mikhail Golubkov
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Food Chain ◽  
Native Species ◽  
Isotope Analysis ◽  
Marine Species ◽  
Trophic Levels ◽  
Benthivorous Fish ◽  
Neva Estuary ◽  
The Baltic

The paucity of data on non-indigenous marine species is a particular challenge for understanding the ecology of invasions and prioritising conservation and research efforts in marine ecosystems. Marenzelleria spp. are amongst the most successful non-native benthic species in the Baltic Sea during recent decades. We used stable isotope analysis (SIA) to test the hypothesis that the dominance of polychaete worm Marenzelleria arctia in the zoobenthos of the Neva Estuary after its invasion in the late 2000s is related to the position of this species in the benthic food webs. The trend towards a gradual decrease in the biomass of Marenzelleria worms was observed during 2014–2020, probably due to significant negative relationships between the biomass of oligochaetes and polychaetes, both of which, according to SIA, primarily use allochthonous organic carbon for their production. The biomass of benthic crustaceans practically did not change and remained very low. The SIA showed that, in contrast to the native crustacean Monoporeia affinis, polychates are practically not consumed either by the main invertebrate predator Saduria entomon, which preys on M. affinis, oligochaetes and larvae of chironomids or by benthivorous fish that prefer native benthic crustaceans. A hypothetical model for the position and functional role of M. arctia in the bottom food web is presented and discussed. According the model, the invasion of M. arctia has created an offshoot food chain in the Estuary food webs. The former dominant food webs, associated with native crustaceans, are now poorly developed. The lack of top-down control obviously contributes to the significant development of the Marenzelleria food chain, which, unlike native food chains, does not provide energy transfer from autochthonous and allochthonous organic matter to the upper trophic levels. The study showed that an alien species, without displacing native species, can significantly change the structure of food webs, creating blind offshoots of the food chain.

scholarly journals TOLAK UKUR FUNGSI HATI BERDASARKAN DERAJAT FIBROSIS PENYAKIT HATI KRONIS (Liver Function Parameters based on Degree of Liver Fibrosis in Chronic Liver Disease)

2018 ◽  
Vol 21 (1) ◽  
pp. 57
Author(s):  
Rahmafitria Rahmafitria ◽  
Mutmainnah Mutmainnah ◽  
Ibrahim Abdul Samad
Keyword(s):  
Liver Disease ◽  
Liver Fibrosis ◽  
Liver Function ◽  
Chronic Liver Disease ◽  
Total Bilirubin ◽  
Chronic Liver ◽  
Low Degree ◽  
Significant Difference ◽  
The Mean ◽  
High Degree

Evaluating the degree of liver fibrosis degree is invasive as well as uncomfortable, therefore, non invasive examinations such as liverfunction tests and elastography (Fibro Scan) as a predictor‘s device of liver fibrosis degree are necessary. The aim of this study was toknow the differences of liver function parameters based on the fibrosis degree in patients with chronic liver disease. This study was a crosssectional design using data from chronic liver disease patients treated at the Dr. Wahidin Sudirohusodo Hospital. The elasticity of the liverwas measured using a fibro scan device during June 2010–July 2011. The analysis was carried out by ANOVA test on various parametersof liver function particularly on the fibrosis degree in chronic liver disease. In this study PT, albumin, total bilirubin and platelet countshowed a significant difference of 0.019, 0.009, 0.017 and 0.000 respectively. The mean values of PT and total bilirubin were significantlyhigher in the high degree of fibrosis compared to those with medium and low degree of fibrosis in the chronic liver disease patients. Basedon this study, the mean albumin levels and platelet count were significantly lower in the high degree of fibrosis compared with the mediumand low degree of fibrosis, however, no significant differences in AST, ALT, APTT and GGT were found.

Yemeni EFL Student Teachers’ Moral Intelligence and its Relationship to their Academic Achievement: الذكاء الأخلاقي للطلاب اليمنيين الدارسين للغة الإنجليزية كلغة أجنبية وعلاقته بأدائهم الأكاديمي

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Mohammad Abdu Ahmed Al-Mekhlafi
Keyword(s):  
Academic Achievement ◽  
Student Teachers ◽  
Male Student ◽  
College Of Education ◽  
Low Achievers ◽  
Teacher Preparation Program ◽  
The Mean ◽  
Moral Intelligence ◽  
High Degree ◽  
The Relationship

This corelational study aimed at investigating the relationship between the moral intelligence of a group of Yemeni EFL student teachers and their academic achievement. It also aimed at finding out any statistically significant differences between the moral intelligence of the student teachers who are categorized into high and low achievers. One hundred and twelve Yemeni EFL student teachers of a third level in the teacher preparation program at the Department of English in the College of Education at Sana’a University in Yemen participated in this study. Their ages ranged between 21 and 25 years. Data were collected using a literature-based questionnaire. The results of this study show that the mean of the ten categories of the moral intelligence is 4.02 (80.4%) indicating a high degree of moral intelligence. The results show that there is no statistically significant differencesat the 0.05 level between the moral intelligence and academic achievement in the Morphology and Syntax course. The results also indicate that there are no statistically significant differences at the level of 0.05 between high and low achievers on nine categories of the moral intelligence. Furthermore, the results indicate that there are no statistically significant differences at the level of 0.05 between female and male student teachers on nine categories of the moral intelligence, namely: Faith, Honesty, Integrity, Courage, Discipline, Responsibility, Service, Kindness and Courtesy. The study findings confirm the previous studies and present some suggestions for further research.

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