Indice de maturité et conservation en fonction de la période de récolte des semences d'épinette blanche du Québec

1992 ◽  
Vol 22 (10) ◽  
pp. 1516-1523 ◽  
Author(s):  
Stéphan Mercier ◽  
Charles-Gilles Langlois
Keyword(s):  
Specific Gravity ◽  
Cavity Length ◽  
Germination Rate ◽  
White Spruce ◽  
The Other ◽  
Seed Maturity ◽  
Immature Seeds ◽  
Significant Difference

White spruce cones were harvested weekly to identify the period of maturity of seed and verify the efficiency of some indicators of maturity. The cones were collected in five stations distributed all over Quebec. The results show that the seeds reached maturity about 1 or 2 weeks before scattering. It seems preferable to collect them at this time because their germination rate is better and they maintain good viability after 15 months of stocking. The seed maturity of white spruce in Quebec may be determined by one of the following indices: the embryo reaches 90% of embryo cavity length, cone moisture is 63%, cone specific gravity is 0.99 g/L, or about 80% of cones float in a solution of methanol (d = 0.93 g/L). These indicators have shown that the northernmost station, Les Escoumins, scattered immature seeds. On the other end, the germination rate of seeds present into opened cones drop gradually. However, we did not notice any significant difference between the germination rate of scattered seeds and that of seeds left in opened cones. The effect of seed sorting on the results is also discussed.

Aptitudes germinatives comparées de graines de Rumex acetosella issues de populations correspondant à des stades distincts d'une succession postculturale

1988 ◽  
Vol 66 (7) ◽  
pp. 1381-1390 ◽  
Author(s):  
J. Escarré ◽  
C. Houssard
Keyword(s):  
Seed Weight ◽  
Plant Biomass ◽  
Germination Rate ◽  
The Other ◽  
Mother Plant ◽  
Old Fields ◽  
Rumex Acetosella ◽  
Significant Difference ◽  
Flowering Rate ◽  
Mother Plants

Germination of Rumex acetosella L. was studied under a variety of experimental conditions to determine whether populations from old fields of different ages (fallow for 6 months to 15 years) differed in seed weight and germination rate and in plant biomass and flowering rate of the resulting plants. Fresh seeds collected from these natural populations showed differences in germination that varied with the date of harvest and the number of years since the field was last cultivated: seeds of the youngest population harvested in July germinated the best and were lighter than those of the other populations. Different fertilizer levels applied during the growth of the mother plants from seeds collected in the original old fields affected the mean weight and the germination rate of the resulting seeds, regardless of the density of cultivation of the mother plant. However, the effect of different fertilizer levels on mean seed weight varied with the origin of each population. Heavy seeds (mean weight > 0.6 mg) of mother plants from the populations of fields abandoned over 2 years ago germinated better than light seeds (mean weight < 0.6 mg). There was no significant difference between heavy and light seeds in terms of percent germination for seeds from mother plants that came from the "youngest" field. These differences in germination rate observed in field-collected seeds were also found in light seeds of the offspring generation: light seeds of the mother plant from the population belonging to the more recently abandoned old field germinated the best. Plants grown from heavy seeds that came from the other populations of older fields had more biomass than those resulting from light seeds. This difference has not been observed between individuals resulting from light and heavy seeds of the youngest population. On the other hand, these individuals had a higher flowering rate than those resulting from the older populations. These results are interpreted in relation to the successional status of the populations: high flowering and early germination rates are suitable characteristics for establishment of plants on bare ground or after a disturbance, whereas heavy seeds with more reserves ensure germination and enough biomass of the resulting plants in density-dependent conditions.

scholarly journals A Detailed Analysis Of Clinical Measurement Error In Ultrafiltration In Peritoneal Dialysis

2021 ◽  
Author(s):  
Zanzhe Yu ◽  
Zhuqing Wang ◽  
Qin Wang ◽  
Minfang Zhang ◽  
Haijiao Jin ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Measurement Error ◽  
Specific Gravity ◽  
Pure Water ◽  
The Other ◽  
Cross Sectional ◽  
Clinical Measurement ◽  
Significant Difference ◽  
Higher Temperature ◽  
The Difference

Abstract BackgroundIt has been noticed for years that ultrafiltration is important for survival in peritoneal dialysis. On the other hand, ultrafiltration measurement is much more complicated than it thought to be. Both overfill and flush before fill used to be source of measurement error. However, controversy finding around ultrafiltration in peritoneal dialysis still exists.MethodsFour different brands of dialysate were purchased from the market. The freshest dialysate available in the market were intentionally picked. The dialysate were all 2L, 2.5% dextrose and traditional lactate buffered PD solution. They were stored in four different conditions with controlled temperature and humidity. The bags were weight at baseline, 6 months and 12 months of storage. Specific gravity was measured in mixed 24 hour drainage dialysate from 261 CAPD patients in a cross sectional manner. ResultsThere was significant difference in dialysate bag weight at baseline between brands. The weight declined significantly after 12 months storage. The weight loss was more significant in higher temperature and lower humidity. The dialysate in non-PVC package lose less weight than PVC package. The specific gravity of dialysate drainage was significantly higher than pure water and related to dialysate protein concentration.ConclusionStorage condition and duration, as well as the type of the dialysate package gave extra variance in overfill volume. The fact that specific gravity of dialysate drainage is higher than 1g/ml also contributes to systemic measurement error of ultrafiltration in manual exchanges.Trial Registration: ClinicalTrials.gov ID: NCT03864120 (March 8, 2019) (Understand the Difference Between Clinical Measured Ultrafiltration and Real Ultrafiltration)

Response of Flamboyant seeds (Delonix regia) subjected to different dormancy overcoming methods

2021 ◽  
Vol 14 (3) ◽  
pp. 1-4
Author(s):  
R. R. Rocha ◽  
C. G. B. G. D. Mariussi ◽  
S. N. Silva ◽  
R. Noetzold
Keyword(s):  
Sulfuric Acid ◽  
Experimental Design ◽  
Efficient Method ◽  
Root Length ◽  
Germination Rate ◽  
Hot Water ◽  
The Other ◽  
Seedling Height ◽  
Significant Difference ◽  
Concentrated Sulfuric Acid

Flamboyant has great ornamental use, because it has beautiful flowers, having a great use in urban afforestation and park ornamentation. The seeds have a low germination rate because they have dormancy caused by the impermeability of the integument. In this sense, the objective was to determine the most efficient method to overcome dormancy in flamboyant seeds. The experimental design was fully randomized with 4 treatments and 3 replications. The treatments consisted of: 1-Witness (non-scarified seeds); 2- Hot water at 90º C for 5 minutes; 3- Concentrated sulfuric acid 98% for 60 minutes; 4- Mechanical scarification with sandpaper number 80. The characteristics evaluated were: emergency, emergency speed index, seedling height and root length. A significant difference can be observed in the treatments evaluated only for the emergency speed index where the scarification treatment with sandpaper was higher than the others, for the other characteristics evaluated there was no difference

Cavity Length Affects the Occupation of Trap-Nests by Centris analis and Tetrapedia diversipes (Hymenoptera: Apidae)

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 261
Author(s):  
Claudia Oliveira Santos ◽  
Paulo Enrique Cardoso Peixoto ◽  
Cândida Maria Lima Aguiar
Keyword(s):  
Cavity Length ◽  
Mortality Rates ◽  
The Other ◽  
Pollination Service ◽  
Cavity Nesting ◽  
Trap Nests ◽  
Significant Difference ◽  
Tetrapedia Diversipes ◽  
Trap Nest ◽  
The Ideal

The ideal cavity dimensions for neotropical cavity-nesting bees with the potential to be managed as pollinators have not been getting proper attention. We investigated whether the occupancy of trap-nests by Centris analis Fabricius and Tetrapedia diversipes Klug, and other nesting aspects, are affected by different trap-nest length. The used trap-nests were cardboard tubes 5, 10, 15 and 20 cm in length, and Ø 8 mm. Occupation rates of 10-cm trap-nests by C. analis was higher than that of the 5-cm ones (χ2=11.17, gl=1, p<0.001). On the other hand, there was not difference between the occupation rates of 10 and 15-cm long trap-nests (χ2=0.51, gl=1, p=0.48), and between the ones measuring 15 and 20 cm long (χ2=1.36, gl=1, p=0.24). T. diversipes occupied a smaller number of 5-cm trap-nests than the 10-cm ones (χ2=1.52, gl=1, p=0.22), as well as that the 15-cm ones were more occupied than the 10-cm trap-nests (χ2=4.23, gl=1, p=0.04); moreover, there was not difference between the occupation of 15 and 20-cm trap-nests (χ2=0.28, gl=1, p=0.59). Both species showed higher rates of dead immatures in nests set in the shortest trap-nests, whereas these mortality rates were lower in the longest ones. By taking into consideration that there was not significant difference in many of the assessed parameters in comparison to values recorded for 15 and 20-cm long trap-nests, it seems likely to recommend the adoption of 10-cm long trap-nests for C. analis reproduction in agricultural sites that depend on the pollination service provided by this bees species.

DO LIGHT AND LITTER INFLUENCE THE RECRUITMENT OF CISTUS SPP. STANDS?

1999 ◽  
Vol 47 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Louis Trabaud ◽  
Philippe Renard
Keyword(s):  
Seed Bank ◽  
Germination Rate ◽  
Soil Surface ◽  
Local Communities ◽  
The Other ◽  
Experimental Conditions ◽  
Large Numbers ◽  
Significant Difference ◽  
Two Factors ◽  
Population Recruitment

After a major disturbance (such as fire or soil upsetting), large numbers of Cistus spp. seedlings may appear and ensure population recruitment, but in the absence of such disturbances seedlings are rare or nonexistent in mature Cistus stands. What are the causes? Two factors, little studied until now, have been examined: the influence of litter and of light reaching the soil surface. In two types of stands, one dominated by C. monspeliensis and the other by C. albidus, an experiment was undertaken by removing the vegetation cover and by the presence or absence of litter to examine the establishment of seedlings. The seed bank in the soil was also studied to determine its size. Seeds were also subjected to a temperature of 52 °C to simulate exposure to full sunlight in summer and determine whether this had any affect on their germination rate. Light and litter had no effect on the germination, irrespective of the quality or intensity of light reaching the soil or the presence or absence of litter; there were always few seedlings and there was no significant difference in numbers between treatments. There was a large seed bank in the soil and these seeds were capable of germinating following experimental conditions: the heat stress applied proved to be too slight to break seed dormancy, although they were viable because they germinated after scarification. In existing Cistus spp. stands, Cistus spp. seeds germinate with difficulty, and lack of recruitment could lead to disappearance of local communities unless they are subjected to disturbances.

scholarly journals Regeneration of White Spruce Under Aspen Canopies: Seeding, Planting, and Site Preparation

2000 ◽  
Vol 15 (4) ◽  
pp. 177-182 ◽  
Author(s):  
James D. Stewart ◽  
Simon M. Landhäusser ◽  
Kenneth J. Stadt ◽  
Victor J. Lieffers
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Germination Rate ◽  
White Spruce ◽  
Seed Rain ◽  
Growing Seasons ◽  
Significant Difference ◽  
Different Types ◽  
And Control ◽  
Northern Alberta

Abstract This study investigated the establishment and survival of naturally and artificially seeded white spruce (Picea glauca), as well as three sizes of planted white spruce stock, on different types of scarification beneath mature aspen (Populus tremuloides) in northern Alberta. White spruce seed rain, natural and hand-seeded regeneration establishment and survival, and understory vegetation response were monitored for 4 yr on scarified strips (light blading, heavy blading, and ridged) and on undisturbed controls. Despite a heavy seed rain in 1993, seedling establishment on control plots was almost nil. On scarified plots, the number of seeds required to produce a live seedling after 3 growing seasons ranged from 15 to 37 and up to 68 in one site. Most mortality occurred during the summer. Germination rate on the hand-seeded plots ranged from 19 to 28% on the scarified strips. There was no significant difference in survival from seed (15%) after three growing seasons among the three scarification treatments. Survival of planted stock was 98% on scarified strips and 96% on control strips. Diameter growth was least on control plots but was not significantly different among the scarified treatments. In contrast, height increment was greatest on the light blading treatment and differed little among the other two treatments and control. These results suggest that spruce regeneration in aspen forests can be promoted by scarification or underplanting. West. J. Appl. For. 15(4):177–182.

Writing in Aphasia Rehabilitation: Cursive vs Manuscript

1976 ◽  
Vol 41 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Daniel R. Boone ◽  
Harold M. Friedman
Keyword(s):  
Correct Response ◽  
The Other ◽  
Read Aloud ◽  
Writing Style ◽  
Reading And Writing ◽  
Manual Responses ◽  
Significant Difference ◽  
Written Form ◽  
The Individual ◽  
Read Number

Reading and writing performance was observed in 30 adult aphasic patients to determine whether there was a significant difference when stimuli and manual responses were varied in the written form: cursive versus manuscript. Patients were asked to read aloud 10 words written cursively and 10 words written in manuscript form. They were then asked to write on dictation 10 word responses using cursive writing and 10 words using manuscript writing. Number of words correctly read, number of words correctly written, and number of letters correctly written in the proper sequence were tallied for both cursive and manuscript writing tasks for each patient. Results indicated no significant difference in correct response between cursive and manuscript writing style for these aphasic patients as a group; however, it was noted that individual patients varied widely in their success using one writing form over the other. It appeared that since neither writing form showed better facilitation of performance, the writing style used should be determined according to the individual patient’s own preference and best performance.

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.

IMMUNOLOGICAL REACTIVITY OF INSULIN IN HUMAN SERUM

1966 ◽  
Vol 53 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Torsten Deckert ◽  
Kai R. Jorgensen
Keyword(s):  
Normal Subjects ◽  
The Other ◽  
Human Pancreas ◽  
Porcine Pancreas ◽  
Crystalline Insulin ◽  
Endogenous Insulin ◽  
Significant Difference ◽  
Human Sera ◽  
Normal Human ◽  
The One

ABSTRACT The purpose of this study was to investigate whether a difference could be demonstrated between crystalline insulin extracted from normal human pancreas, and crystalline insulin extracted from bovine and porcine pancreas. Using Hales & Randle's (1963) immunoassay no immunological differences could be demonstrated between human and pig insulin. On the other hand, a significant difference was found, between pig and ox insulin. An attempt was also made to determine whether an immunological difference could be demonstrated between crystalline pig insulin and crystalline human insulin from non diabetic subjects on the one hand and endogenous, circulating insulin from normal subjects, obese subjects and diabetic subjects on the other. No such difference was found. From these experiments it is concluded that endogenous insulin in normal, obese and diabetic human sera is immunologically identical with human, crystalline insulin from non diabetic subjects and crystalline pig insulin.

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

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