scholarly journals Taxon‐specific dark survival of diatoms and flagellates affects Arctic phytoplankton composition during the polar night and early spring

2019 ◽  
Vol 65 (5) ◽  
pp. 903-914 ◽  
Author(s):  
Willem H. Poll ◽  
Edwin Abdullah ◽  
Ronald J. W. Visser ◽  
Philipp Fischer ◽  
Anita G. J. Buma
2011 ◽  
Vol 63 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Ondřej Koukol
Keyword(s):  

Author(s):  
W.M. Williams ◽  
L.B. Anderson ◽  
B.M. Cooper

In evaluations of clover performances on summer-dry Himatangi sandy soil, it was found that none could match lucerne over summer. Emphasis was therefore placed on production in autumn-winter- early spring when lucerne growth was slow. Evaluations of some winter annual clover species suggested that Trifolium spumosum, T. pallidum, T. resupinatum, and T. vesiculosum would justify further investigation, along with T. subterraneum which is already used in pastures on this soil type. Among the perennial clover species, Kenya white clover (7'. semipilosum) showed outstanding recovery from drought and was the only species to produce significantly in autumn. However, it failed to grow in winter-early spring. Within red clover, materials of New Zealand x Moroccan origin substantially outproduced the commercial cultivars. Within white clover, material from Israel, Italy and Lebanon, as well as progeny of a selected New Zealand plant, showed more rapid recovery from drought stress and subsequently better winter growth than New Zealand commercial material ('Grasslands Huia'). The wider use of plant material of Mediterranean origin and of plants collected in New Zealand dryland pastures is advocated in development of clover cultivars for New Zealand dryland situations.


2020 ◽  
Vol 9 (4) ◽  
pp. 35-43
Author(s):  
Chris Ingraham

Drawing from in situ fieldwork in Longyearbyen, Svalbard, the northernmost settlement on Earth, these notes bring out the affective, ambient, and atmospheric power of extended darkness during the polar night, when the sun does not appear above the horizon for several months at a time. Each entry is composed of 113 words to reflect the number of days without light in Longyearbyen during the winter of my visit. Through a mixture of ethnographic observations, researched academic scholarship, and some endeavors of poetic worldmaking, these notes attempt to evoke the ineffable force of global warming by performing the sort of acutely observed and felt attentiveness to planetary being that is needed for our time.


Author(s):  
I.N. Voronchikhina ◽  
◽  
A.G. Marenkova ◽  
V. S. Rubets ◽  
V. V. Pylnev

The results of elements development of varietal agrotechnics of a new high-potential line 238h of winter triticale presented. It was identified that under the conditions of 2020 the most cost effective fertilizer system is an early spring application of NPK (S) (15-15-15 (10)) at a dose of 200kg/ha. The profitability level of this fertilizer was 88,9%.


2017 ◽  
Vol 1 (92) ◽  
pp. 78-84
Author(s):  
G. Koval ◽  
M. Kaliyevskiy ◽  
V. Yeshchenko ◽  
I. Martyniuk ◽  
N. Martyniuk

The article presents the results of field experiments, where on the basis of podsolized heavy loamy chernozem the influence of replacement of mouldboard ploughing with nonmouldboard cultivation over top soil weediness, weediness at the beginning and end of spring crop vegetation and weed species composition before harve sting were studied. Investigation methods of main fall ploughing under spring crops of five-course rotation: soybeans–rape–wheat–flax–barley at the depths of 15-17, 20-22, 25-27 cm were conducted after post-harvest field tillage. Analysis of data on contamination of the top soil with weed seeds have shown that with the replacement of fall main mouldboard ploughing gwith nonmouldboard cultivation the figure before sowing of all crops withdifferent tillage depthat crop rotation average increased by 131-132%. It caused the increase of actual weed infestation of all crops and at the beginning and end of spring crop vegetationafter different depths of fall nonmouldboard cultivation compared with ploughing at crop rotation average it was 120–132 and 123-138%respectively. Species composition of weeds afterthe replacement of main fall mouldboard ploughing with nonmouldboard cultivation remained mainlyunchanged; although in rape plantings the proportion of white campion and early spring weed sincreased, in wheat plantings– wild mustard andscentless mayweed, insoybean plantings– late spring weeds, in flax plantings– white campion, and in barley plantings– scarlet pimpernel.


2018 ◽  
Author(s):  
Shelby L. Levine ◽  
Isabelle Green-Demers ◽  
Marina Milyavskaya ◽  
Kaitlyn M. Werner

The present study examined the influence of personal standards and self-critical perfectionism on depressive and anxiety symptoms over the academic year. High-school students (N=174) were surveyed in the late Fall and early Spring, assessing perfectionism in the Fall and mental health across the year in both the Fall and Spring. Path modelling was used to examine whether self-critical and personal standards perfectionism were related to changes in mental health across the school year. Controlling for mental health at the start of the year, self-critical perfectionism predicted an increase in depressive symptoms over time, whereas personal standards perfectionism was unrelated to changes in mental health. Results support that self-critical perfectionism is detrimental to mental health in adolescents, suggesting that future interventions should focus on reducing self-critical cognitive biases in youth.


Author(s):  
Majid Baserisalehi ◽  
Samira Zarezadeh ◽  
Majid Baserisalehi ◽  
Saeed Shoa

Stenotrophomonas maltophilia is an emerging pathogenic non-fermentative Gram-negative Bacillus species. It has caused many nosocomial infections and can be isolated from various hospital wards and healthcare facilities. Research has shown that most of its strains are inherently resistant to many antibiotics and have multidrug resistance. This research intended to determine its occurrence frequency at some Hospitals in shiraz, Iran. The present study was conducted in six months (from early spring to late summer 2019). Clinical samples (Blood, Urine and cerebrospinal fluid (CSF)) collected from 120 patients afflicted with various infections. The samples were transferred to the Laboratory and subjected to microbiological analysis. Identification of the isolates was carried out by phenotypic methods and Stenotrophomonas maltophilia isolates verified using molecular methods. In total, various bacteria were isolated from 84 clinical samples. The isolates were Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Stenotrophomonas maltophilia, Staphylococcus aureus and Pseudomonas aeruginosa. Stenotrophomonas maltophilia was isolated from 17 (20.2%) positive samples and most of them were isolated from blood samples. Our finding indicated that Stenotrophomonas maltophilia isolated more from blood samples follow by CSF sample. In addition, our finding illustrated that Stenotrophomonas maltophilia can be considered as the common nosocomial agent at hospitals in Shiraz, Iran.


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