scholarly journals Response of Water-Salt Migration to Brackish Water Irrigation with Different Irrigation Intervals and Sequences

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2089 ◽  
Author(s):  
Zhu ◽  
Yang ◽  
Sun ◽  
Zhang
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Irrigation Treatment ◽  
Water Infiltration ◽  
Laboratory Simulation ◽  
Irrigation Interval ◽  
Significant Difference ◽  
Soil Desalination ◽  
The Mean ◽  
Irrigation Treatments

Establishing methods for scientific and rational use of brackish water resources is the key to farmland irrigation in the Yellow River Delta region of China. In this study, we conducted laboratory simulation experiments with soil columns and monitored the changes in water infiltration and salt distribution under eight irrigation treatments, including four intervals (0, 30, 60, and 90 min between irrigations) and two sequences (brackish-brackish-fresh water and brackish-fresh-brackish water). The results showed that the duration of water infiltration into the soil was higher under intermittent irrigation than continuous irrigation, with the highest value recorded at the 90-min irrigation interval. There was no significant difference in the mean soil water content between the brackish-brackish-fresh water (28.01–29.71%) and brackish-fresh-brackish water (28.85–29.98%) irrigation treatments. However, the mean soil desalination rate of the brackish-brackish-fresh irrigation treatment (42.51–46.83%) was higher than that of the brackish-fresh-brackish irrigation treatment (39.48–46.47%), and a much higher soil desalination rate was observed at the 90-min irrigation interval, compared with the other intervals. In conclusion, brackish-brackish-fresh water irrigation at longer time intervals (e.g., 90 min between irrigations) is conducive to reduce soil salt content in the surface soil in the study region.

Experimental and field studies on the viability of eggs, and the infectivity of third-stage larvae of the human hookworm Necator americanus recovered from the creek waters of the Niger Delta, Nigeria, and their epidemiological significance

Parasitology ◽  
1988 ◽  
Vol 96 (1) ◽  
pp. 111-117 ◽  
Author(s):  
J. K. Udonsi
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Niger Delta ◽  
Field Studies ◽  
Host Population ◽  
Water Contact ◽  
Necator Americanus ◽  
Brackish Waters ◽  
Significant Difference ◽  
Laboratory Cultures

SUMMARYIn a combined field and laboratory study, the eggs and 3rd-stage infective larvae of the human hookworm Necator americanus were recovered from the creek waters of the Niger Delta, Nigeria. They were tested for viability and infectivity. Eggs recovered from fresh water creeks showed a viability or hatching index of between 17·5 and 23·7%. Eggs recovered from brackish water showed a viability index of 18·8–21·4% in ‘normal’ cultures, and a maximum index of 6·3% when cultured in brackish water. The differences in the viability indices of these eggs were not significant (P > 0·05). Infective 3rd-stage larvae were recovered from both fresh creek water (205–258 L3/litre of water), and brackish water (45 L3/litre of water). Larvae hatched from brackish water eggs that were cultured in the brackish water were 20% infective by 3 days, but lost all infective potential by 7 days posthatching. Larvae from fresh water eggs, cultured in fresh water and ‘normal’ laboratory cultures reached 50% infectivity in 3–5 days, losing potential infectivity in 11–15 days posthatching. The infectivity patterns of larvae recovered directly from fresh and brackish waters did not differ significantly (P > 0·05) from the infectivity patterns of larvae recovered from laboratory cultures of eggs from all the experimental sources. Although larvae recovered directly from fresh and brackish waters survived in these respective media under laboratory conditions, there was a significant difference (P < 0·05) in their survival patterns. The survival and infectivity rates of field larvae were considerably reduced over time relative to control larvae. These results indicate that both contaminated fresh and brackish water creeks and their banks may form additional hookworm infection foci in areas where various water contact activities are carried out by the human host population.

Yield and net return from alfalfa cultivars under irrigation in Southern Alberta

2016 ◽  
Vol 96 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Jeremiah Attram ◽  
Surya N. Acharya ◽  
Shelley A. Woods ◽  
Elwin Smith ◽  
James E. Thomas
Keyword(s):  
Root Zone ◽  
Block Design ◽  
Irrigation Treatment ◽  
Field Studies ◽  
Available Water ◽  
Net Returns ◽  
Southern Alberta ◽  
Randomized Complete Block Design ◽  
The Mean ◽  
Irrigation Treatments

Field studies with two types of alfalfa (Medicago sativa L.) cultivars were conducted at Lethbridge in 2012 and 2013 and at Picture Butte in 2012 to determine the effects of irrigation on the dry matter (DM) yield and on net returns. The irrigated cultivars (Longview and Blue J) and dryland cultivars (Rangelander and Rambler) were arranged on plots in a randomized complete block design with four irrigation treatments and replicated five times. For the optimal irrigation treatment (W1), soil water content was maintained between 60 and 90% of available water in the designated root zone. Other irrigation treatments received 75% (W2), 50% (W3), and 25% (W4) of the irrigation water applied to the optimal treatment. The mean DM yields of irrigated alfalfa cultivars were greater than one of the dryland cultivars in both locations. The mean total DM yields for W2 and W3 at Lethbridge for Blue J, Longview and Rambler were greater than those of W1, although the differences were not always significant. The net returns, calculated by using the same price for all alfalfa harvests were similar across the cultivars and irrigation treatments excepting Rangelander, where the returns were lower. The results obtained from this study indicated a trend towards comparable yields and net returns between the optimal and the 75% irrigation treatment with 40% depletion of available water at the root zone, for the irrigated alfalfa cultivars and a dryland type Rambler.

Late Holocene Sea-Level Record in a Core from the Puget Lowland, Washington

1987 ◽  
Vol 27 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Matti Eronen ◽  
Tuovi Kankainen ◽  
Matsuo Tsukada
Keyword(s):  
Sea Level ◽  
Fresh Water ◽  
Brackish Water ◽  
Late Holocene ◽  
Relative Sea Level ◽  
The Past ◽  
Tide Level ◽  
Upper Intertidal ◽  
The Mean ◽  
Early And Middle Holocene

AbstractDiatoms and lithological facies of an 8.45-m core collected from Shine swamp (47°52′20″N lat, 122°41′45″W long; about 2 m above the mean tide level) in the northern Puget Lowland reveal a rise in relative sea level during the past 6000 yr. A layer of fresh-water peat at a depth of 6.6-6.3 m (ca. 7000-5000 yr B.P.) indicates a low stand of the sea in early and middle Holocene time. About 5000 yr ago the rise in relative sea level resulted in accumulation of subtidal or lower intertidal clayey gyttja and gyttja which contain mainly marine and brackish-water diatoms (80–95%). By about 3500 yr B.P., the basin had shoaled to upper intertidal levels, and peat began to accumulate again while the sea continued its relative rise. During the period of this continuous peat growth, several alterations in fresh-water and marine/brackish-water diatom assemblages took place, indicating slight differences in the contemporaneous sea-level rise and vertical peat growth.

scholarly journals Morphometric studies of the craniofacial region of the African sideneck turtle (Pelusios castaneus)

2014 ◽  
Vol 31 (03) ◽  
pp. 135-138
Author(s):  
O. Igado ◽  
S. Olukole ◽  
B. Oke
Keyword(s):  
Clinical Practice ◽  
Fresh Water ◽  
Morphometric Analysis ◽  
Palpebral Fissure ◽  
Average Weight ◽  
Regional Anatomy ◽  
Significant Difference ◽  
Left And Right ◽  
The Mean ◽  
Positive Correlations

Abstract Introduction and Methods: Morphometric analysis of the craniofacial regions of the African sideneck turtle (Pelusios castaneus) were carried out with the aim of generating data which could be useful in wildlife veterinary clinical practice as well as in the comparative regional anatomy of turtles. Results: The average weight of turtles used for this study was 0.51 ± 0.39kg, while the mean weight of head was 20 ± 6.50g. The mean palpebral fissure lengths for the left and right eyes were 0.75 ± 0.10 and 0.77 ± 0.11cm respectively, while the orbital heights of the left and right eyes and the distance between the medial canthi were 0.74 ± 0.11, 0.75 ± 0.11 and 0.59 ± 0.10cm respectively. Out of the twenty parameters measured, only four showed statistically significant difference (P<0.05) between the sexes, with the male values being higher in all the four cases. There were strong positive correlations between the left and right lengths of palpebral fissure (r= 0.959) and between the left and right orbital heights (r= 0.964). Conclusion: The data obtained in this study, being the first report on craniofacial indices of the African sideneck turtle, is expected to serve as baseline data on the craniofacial anatomy of the animal and hence in the comparative regional anatomy of both fresh water and sea turtles.

scholarly journals Effect of water stress on leaf nutrient status and frequency of irrigation in various cultivars of kiwifruit

2018 ◽  
Vol 10 (1) ◽  
pp. 339-346
Author(s):  
Preet Pratima ◽  
N. Sharma ◽  
Chaitanya Belsare
Keyword(s):  
Deficit Irrigation ◽  
Block Design ◽  
Irrigation Treatment ◽  
Field Capacity ◽  
Nutrient Status ◽  
Nutrient Content ◽  
Leaf Nitrogen ◽  
Nutrient Contents ◽  
Irrigation Interval ◽  
Irrigation Treatments

The five cultivars of kiwifruit viz., Allison, Hayward, Abbott, Monty and Bruno during the years 2011 and 2012 in the Department of Fruit Science, Dr. Y. S. Parmar University of Horticulture and Forestry, Solan, Himachal Pradesh, India. Two irrigation treatments i.e. standard irrigation (at 80% field capacity) and deficit irrigation (at 60 % F C) were applied to these cultivars from March to October with three replications in Randomized Block Design (RBD). The leaf nutrient content (%) and frequency of irrigation (irrigation interval in days) were investigated in kiwifruit in response to these irrigation treatments. The leaf nitrogen (N), phosphorus (P), Potassium (K), Calcium (Ca) and Magnesium (Mg) contents varied with cultivars under two irrigation regimes. The leaf N content and Ca content (%) was observed highest in cultivar Monty; P content in Allison; K content in Hayward; Mg content (%) in Abbott and Monty under standard irrigation treatment. These nutrient contents reduced significantly at 0.05 % level of significance with deficit irrigation treatment in different cultivars. The % reduction in these nutrients with deficit irrigation treatment was found to be highest in cultivar Hayward and the least in Bruno. The total number of irrigation applied under standard and deficit irrigation were 16 and 10 respectively, during both the years. The response of Bruno cultivar in terms of leaf nutrient content under water deficit condition is much better in comparison to all other cultivars. Bruno is considered to be drought tolerant cultivar and Hayward to be drought sensitive. Thus, the Bruno cultivar should be preferred for cultivation in water scarce regions.

Vowel Recognition Threshold as a Function of Temporal Segmentations

1970 ◽  
Vol 13 (4) ◽  
pp. 715-724 ◽  
Author(s):  
Richard L. Powell ◽  
Oscar Tosi
Keyword(s):  
Normal Hearing ◽  
Recognition Threshold ◽  
Vowel Sound ◽  
Significant Difference ◽  
The Mean ◽  
Vowel Recognition ◽  
Temporal Segment

Vowels were segmented into 15 different temporal segments taken from the middle of the vowel and ranging from 4 to 60 msecs, then presented to 6 subjects with normal hearing. The mean temporal-segment recognition threshold of 15 msecs with a range from 9.3 msecs for the /u/ to 27.2 milliseconds for the /a/. Misidenti-fication of vowels was most often confused with the vowel sound adjacent to it on the vowel-hump diagram. There was no significant difference between the cardinal and noncardinal vowels.

Left Ventricular Dysfunction and Blood Glycohemoglobin Levels in Young Diabetics

1991 ◽  
Vol 30 (05) ◽  
pp. 183-188
Author(s):  
A. Aydrner ◽  
A. Oto ◽  
E. Oram ◽  
O. Gedik ◽  
C. F. Bekdik ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Left Ventricular Function ◽  
Ventricular Function ◽  
Left Ventricular ◽  
Diabetic Patients ◽  
Filling Fraction ◽  
Time To Peak ◽  
Significant Difference ◽  
The Mean ◽  
Hba1c Levels

Left ventricular function including regional wall motion (RWM) was evaluated by 99mTc first-pass and equilibrium gated blood pool ventriculography and glycohemoglobin (HbA1c) blood levels determined by a quantitative column technique in 25 young patients with insulin-dependent diabetes mellitus without clinical evidence of heart disease, and in healthy controls matched for age and sex. Phase analysis revealed abnormal RWM in 19 of 21 diabetic patients. The mean left ventricular global ejection fraction, the mean regional ejection fraction and the mean 1/3 filling fraction were lower and the time to peak ejection, the time to peak filling and the time to peak ejection /cardiac cycle were longer in diabetics than in controls. We found high HbA1c levels in all diabetics. There was no significant difference between patients with and without retinopathy and with and without peripheral neuropathy in terms of left ventricular function and HbA1c levels.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Multi-Center Study of Thromboplastin Calibration Precision – Influence of Reagent Species, Composition, and International Sensitivity Index (ISI)

1993 ◽  
Vol 69 (01) ◽  
pp. 035-040 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Oral Anticoagulants ◽  
International Normalized Ratio ◽  
The Other ◽  
World Health ◽  
Rabbit Brain ◽  
Sensitivity Index ◽  
Bovine Plasma ◽  
Significant Difference ◽  
The Mean ◽  
International Sensitivity Index

SummaryFour thromboplastin reagents were tested by 18 laboratories in Europe, North-America, and Australasia, according to a detailed protocol. One thromboplastin was the International Reference Preparation for ox brain thromboplastin combined with adsorbed bovine plasma (coded OBT/79), and the second was a certified reference material for rabbit brain thromboplastin, plain (coded CRM 149R). The other two thromboplastin reagents were another rabbit plain brain thromboplastin (RP) with a lower ISI than CRM 149R and a rabbit brain thromboplastin combined with adsorbed bovine plasma (RC). Calibration of the latter two reagents was performed according to methods recommended by the World Health Organization (W. H. O.).The purpose of this study was to answer the following questions: 1) Is the calibration of the RC reagent more precise against the bovine/combined (OBT/79) than against the rabbit/plain reagent (CRM 149R)? 2) Is the precision of calibration influenced by the magnitude of the International Sensitivity Index (ISI)?The lowest inter-laboratory variation of ISI was observed in the calibration of the rabbit/plain reagent (RP) against the other rabbit/plain reagent (CRM 149R) (CV 1.6%). The highest interlaboratory variation was obtained in the calibration of rabbit/plain (RP) against bovine/combined (OBT/79) (CV 5.1%). In the calibration of the rabbit/combined (RC) reagent, there was no difference in precision between OBT/79 (CV 4.3%) and CRM 149R (CV 4.2%). Furthermore, there was no significant difference in the precision of the ISI of RC obtained with CRM 149R (ISI = 1.343) and the rabbit/plain (RP) reagent with ISI = 1.14. In conclusion, the calibration of RC could be performed with similar precision with either OBT/79 or CRM 149R, or RP.The mean ISI values calculated with OBT/79 and CRM 149R were practically identical, indicating that there is no bias in the ISI of these reference preparations and that these reference preparations have been stable since their original calibration studies in 1979 and 1987, respectively.International Normalized Ratio (INR) equivalents were calculated for a lyophilized control plasma derived from patients treated with oral anticoagulants. There were small but significant differences in the mean INR equivalents between the bovine and rabbit thromboplastins. There were no differences in the interlaboratory variation of the INR equivalents, when the four thromboplastins were compared.

Incubation Temperature Influences the Duration of Egg Hatching and Early Development in the Boreal Digging Frog, Kaloula Borealis

2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae
Keyword(s):  
Water Temperature ◽  
Early Life ◽  
Rainy Season ◽  
Incubation Temperature ◽  
Life Stages ◽  
Early Life Stages ◽  
Egg Hatching ◽  
Significant Difference ◽  
The Mean ◽  
Hatching Rates

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.

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