The Annual Rhythm of Activity of the Lateral Meristems (Cambium and Phellogen) in Pinus Halepensis Mill. and Pinus Pinea L.

IAWA Journal ◽  
1984 ◽  
Vol 5 (4) ◽  
pp. 263-274 ◽  
Author(s):  
Nili Liphschitz ◽  
S. Lev-Yadun ◽  
E. Rosen ◽  
Y. Waisel

The annual rhythms of cambial and phellogen activity in Pinus halepensis and P pinea were investigated. Under natural conditions the cambium of P halepensis begins its activity in autumn, enters a quiescent period during midwinter, resurnes activity towards spring and enters a second rest period in summer. The ring border is formed during summer. Irrigated plants growing outdoors were active almost all the year round.The cambium of P pinea is active between April and November and enters a true winter dormancy.The duration of xylem production exceeded that of the phloem. More xylem than phloem cells were formed. The phellogen was active during a short period only.Pinus halepensis seems to follow the Mediterranean climate patterns whereas P pinea follows the pattern of a colder climate.

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3170
Author(s):  
Wafaa M. Elkady ◽  
Mariam H. Gonaid ◽  
Miriam F. Yousif ◽  
Mahmoud El-Sayed ◽  
Hind A. N. Omar

Active components from natural sources are the current focus in most pharmacological research to provide new therapeutic agents for clinical use. Essential oils from the Pinus species have been traditionally used in medicine. This study aimed to investigate the chemical profile of two Pinus species, Pinus halepensis L. and Pinus pinea Mill, from different altitudes in Libya and study the effect of environmental conditions on the biological activities of essential oils. A clevenger apparatus was used to prepare the essential oils by hydrodistillation. Analyses were done using GC/MS. Anthelmintic and antimicrobial activities were tested against the earthworm Allolobophora caliginosa, gram-positive bacteria, gram-negative bacteria, and fungi. Different chemical profiles were observed among all tested essential oils, and terpenes were the most dominant class. All studied essential oils from the Pinus species exhibited a remarkable anthelmintic activity compared to the standard piperazine citrate drug. Pinus halepensis from both altitudes showed broad-spectrum antimicrobial activity against all tested microorganisms, while Pinus pinea was effective against only Escherichia coli. From these findings, one can conclude that there are variations between studied species. The essential oil compositions are affected by environmental factors, which consequently affect the anthelmintic and antimicrobial activity.


1986 ◽  
Vol 108 (2) ◽  
pp. 267-273 ◽  
Author(s):  
S. Kyakumoto ◽  
R. Kurokawa ◽  
Y. Ohara-Nemoto ◽  
M. Ota

ABSTRACT Cytosol and nuclear androgen receptors in submandibular glands of male and female mice were measured by an exchange assay at 0 °C. The binding of [3H]methyltrienolone to cytosol receptors in females was mostly saturated within a short period of incubation (3 h), whereas the saturation was much slower in males; suggesting that almost all of the cytosol receptors were unoccupied in females and the receptors were partially occupied in males. Nuclear receptors were extracted with pyridoxal 5′-phosphate (5 mmol/l) from nuclear fractions with 93–95% efficiency. The exchange of the bound steroids occurred by 24–48 h at 0 °C, suggesting that most of the nuclear androgen receptor was occupied. The binding was low at higher temperatures, probably due to inactivation of the receptor. Scatchard analysis showed that the apparent dissociation constants of cytosol and nuclear receptors were similar (0·8 and 0·9 nmol/l respectively) in both sexes. On the other hand, the number of androgen-binding sites in the nucleus was much higher in males than in females (1052 fmol/mg DNA and 32 fmol/mg DNA respectively), while the number in the cytosol was higher in females than in males (512 fmol/mg DNA and 368 fmol/mg DNA respectively). These observations show that androgen receptors exist mainly (74%) in the nuclei of males, while they exist mostly (94%) in the cytosol of females. J. Endocr. (1986) 108, 267–273


1972 ◽  
Vol 78 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Marca Burns

SUMMARYBirthcoat samples from Lincoln and Welsh Mountain lambs born in an ova transfer experiment (Weiner & Slee, 1965) were examined to determine the fibre type arrays and any effect of ova transfer on manifestation of the prenatal check or the base (Dry, 1965).In the Lincoln breed arrays were Truncated Ravine or Truncated Valley thus showing central checking. Pre-curly tip fibres were mainly confined to central primary follicles. Post-natal medullation was plentiful, especially in peak curly-tips, but kemp was absent. In the Welsh lambs all identifiable arrays were either Plateau or Saddle, with the lateral primary fibres more checked than the centrals. Pre-curly tip fibres occupied almost all the primary follicles, with only a few curly-tips in primary laterals. Post-natal medullation was strongest in pre-curly tips and their successors.The effect of ova transfer was to decrease the manifestation of check in Lincoln-in-Welsh and increase it in Welsh-in-Lincoln, without affecting the base. Although this, in each case, changed the check of the lamb in the direction of that of the foster breed, it is suggested that this may not be due to any influence of maternal check on foetal check. The effect on pre-natal check may be due to foetal size, and in particular skin expansion, during a short period immediately following completion of primary follicle initiation. As compared to their respective controls, the Welsh transfer lambs had a higher S/P ratio at birth, whilst that of the transferred Lincolns was reduced.If increased prenatal fibre check is associated with increased foetal growth rate at the relevant period, it may also be correlated with increased lamb size at birth and therefore have been favoured in selection for meat production, at least in some breeds.


Stanovnistvo ◽  
2006 ◽  
Vol 44 (1) ◽  
pp. 7-46 ◽  
Author(s):  
Gordana Matkovic

During the last 15 years the entire Western Balkan region has undergone dramatic changes. With the fall of the Berlin wall and the disintegration of the former Yugoslavia, new states were formed and transition started, although in some countries it was quite delayed. Simultaneously, during the nineties, much of the region experienced wars and destruction, waves of refugees, internal displacement of population, devastation of the economy, demolition of institutions and impoverishment of citizens. Absolute poverty, determined through the estimation of household consumption at which families, after paying for essential non-food expenditures just attain minimal nutritional needs, in almost all of the Western Balkans is still relatively high, and is not showing significant tendencies of decreasing. A large concentration of the population and households just above the poverty line additionally demonstrates the challenges faced by the entire region while undergoing the transition process. In some countries extreme poverty, meaning that not even basic food needs can be met, has been registered. On the other hand, relative poverty, defined as the share of those who are excluded from the minimum acceptable way of life in states in which they live, is not particularly high. Due to the relatively high standard of living in the past and high expectations of the population that living standards would increase in a relatively short period of time, the subjective perception of poverty in the entire region is very much present. Groups that stand out as especially vulnerable and excluded are the unemployed, dependents and the less educated. At the level of the household, in some countries households with many children and elderly households are particularly vulnerable. The poorest often live in the rural areas and in the underdeveloped regions. In addition, especially vulnerable groups, who cannot even be completely covered by standard surveys, but are poor and socially excluded by many indices are the Roma, refugees and IDPs and persons with disabilities. Concurrently undergoing transition, post conflict reconciliation and reconstruction and striving to pursue their European Union future, the Western Balkan countries face many challenges. One of the greatest challenges is to focus on programs and activities that will lead to equitable and sustained economic growth that will also benefit the vulnerable groups. Almost all Western Balkan countries, through their national plans and programs, have marked employment growth and job creation as the most important single mechanism for exiting poverty. The second priority may be an increase of education coverage and improving the quality of education, although reduction of poverty and social exclusion presupposes improvement in the areas of developing appropriate social safety nets, health care systems, securing adequate housing, participation in decision making and protection of human rights. Bearing in mind the commitment of the Western Balkan countries to meet the globally agreed goals manifested in the MDGs, their efforts to proceed with anti-poverty strategies and aspirations in terms of EU accession, it is of the utmost importance to explore the synergies between these agendas to ensure that the processes reinforce each other.


2020 ◽  
Vol 200 ◽  
pp. 02014
Author(s):  
Bachtiar W Mutaqin ◽  
Muh Aris Marfai ◽  
Muhammad Helmi ◽  
Nurhadi Nurhadi ◽  
Muhammad Rizali Umarella ◽  
...  

Human pressure on the coastal and aquatic surrounding ecosystem in Indonesia, through plastic waste, is increasing, considering that 60 % of the approximately 250 million people live in the coastal areas. Plastic waste originating from human activities has become a massive problem in almost all the small island and coastal regions, especially in the eastern part of Indonesia. This condition is caused by poor waste management and a lack of public awareness in disposing of waste in its place, including in an area known as its marine biodiversities and marine tourism spots like Masohi in Central Maluku. Also, the composition of waste is dominated by plastic waste that cannot be decomposed in a short period, continue circulated on the ocean currents, and will be deposited in coastal areas. Furthermore, some plastic waste will break down into micro-plastics that pollute not only the environment but also marine biota, which are often consumed by humans. This situation profoundly affects the sustainability and function of aquaecosystem services in coastal areas. Therefore, a comprehensive policy and regulation, and interdisciplinary study for analysing vulnerable coastal ecosystem, and mitigating the potential risk of plastic pollution in Masohi, Central Maluku are essential to be conducted.


2017 ◽  
Vol 10 (1) ◽  
pp. 204-214 ◽  
Author(s):  
JA Manzanera ◽  
A Gómez-Garay ◽  
B Pintos ◽  
M Rodríguez-Rastrero ◽  
E Moreda ◽  
...  

2021 ◽  
Vol 13 (21) ◽  
pp. 11890
Author(s):  
Sanita Baranova ◽  
Dita Nīmante ◽  
Daiga Kalniņa ◽  
Alise Oļesika

In Spring 2020, due to the rapid spread of COVID-19, all educational institutions in Latvia, including the University of Latvia (UL), transitioned from face-to-face on-site learning to remote learning. After a short period of face-to-face on-site learning in autumn, UL returned to remote learning in November for the second time. This paper investigates the UL students’ perspectives on remote teaching and learning at the UL during the first and second COVID-19 periods. The research assesses several remote study organization aspects, including the lecturer’s and student’s digital skills, their access to information and support during the study process, planning and implementation of the study process, and students’ acquisition of the content. The study used an original questionnaire designed in the Spring 2020 semester. Seven questions from the first questionnaire were included in another follow-up questionnaire distributed in the Spring 2021 semester. A total of 2248 UL students from the Spring 2020 semester and 742 students from the Spring 2021 semester participated in the study, representing 13 faculties across all study levels. The survey responses were collected via a QuestionPro survey platform and then downloaded into an IBM SPSS 28 file for a reliability check. Next, descriptive statistical analyses were conducted for each reported survey item using Microsoft Excel 2016. The research presented here implies that, in general, students perceive positive improvements in almost all the investigated aspects of the organization of the remote study process when comparing the first and second COVID-19 periods, which could indicate a certain level of resilience in students and university lecturers when subject to COVID circumstances. However, the results reveal that students have, in one year, developed a more realistic approach in assessing their digital skills. The results lead us to believe that remote on-line learning is not just a short-term solution but could become a valuable element for providing qualitative education in the long term. It could indicate that the students and lecturers at university are ready for new and sustainable higher education study organization solutions in the future.


Epohi ◽  
2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Simeon Tsvetkov ◽  

In the wake of the Crimean War, the upper military circles in Russia changed their thinking with regard to firearms. General Milyutin became Minister of War. It was the time when Alexander II reigned over Russia. In 1856, the calibre of Russian firearms was reduced to 6 inches, or 15.24 mm. The process of re-equipping the Russian army with M1856 rifles using expanding Minié bullets was launched. These rifles demonstrated that the percussion systems had reached the limit of their capacity for improvement. Nothing else could be improved in terms of their firing speed. Despite the resistance of the conservative military circles, Milyutin encouraged new inventions, and the 1860s became a period of experimentation with firearms. Some new cartridge systems were introduced. The high-quality M1856 percussion rifle was not destined to take part in war times, but the Russian army had been fully equipped with it for a short period of time. Almost all systems of the 1860s were based on this rifle. Over 10 systems of firearms with an internal needle fuse were proposed to the weapons commission. In 1866, the Englishman Karle proposed his own system with an internal needle fuse. Krnka, Berdan I, and Berdan II came next. After 1866, the Terry-Norman, Karle, and Krnka rifles entered the Russian army. These systems were developed on the basis of the 6-line M1856/58 rifle. The latter was converted into a rear-loading rifle. In 1869, the Krnka rifle was chosen as the main system, which became the main weapon of the Russian army in the following years. At the beginning of 1877, there were 613,297 Krnka rifles, 150,868 Karle rifles, 17,810 Berdan I and 325,254 Berdan II rifles in the Russian army.


1989 ◽  
Vol 116 (1) ◽  
pp. 537-556 ◽  
Author(s):  
G.W. Wetherill

AbstractBecause there is no necessary connection between the time required to remove the volatile component of a cometary nucleus by solar heating (physical lifetime) and the dynamical lifetime of a comet, it is possible that a comet may evolve into an observable object of asteroidal appearance. Almost all comets have dynamical lifetimes much shorter than their physical lifetimes and in these cases complete loss of volatiles will not occur. Mechanisms do exist, however, whereby a small but significant fraction of comets will have longer dynamical lifetimes, permitting them to evolve first into Jupiter-family short period comets and then into comets with relatively safe decoupled orbits interior to Jupiter’s orbit. Observed Jupiter-family objects of asteroidal appearance (e.g., 1983SA) are much more likely to be of cometary rather than asteroidal origin. “Decoupling” is facilitated by several mechanisms: perturbations by the terrestrial planets, perturbations by Jupiter and the other giant planets (including resonant perturbations) and non-gravitational orbital changes caused by the loss of gas and dust from the comet. The dynamical time scale for decoupling is probably 105–106 years and almost all decoupled comets are likely to be of asteroidal appearance. Once decoupled, the orbits of the resulting Apollo-Amor objects will evolve on a longer (107–108 year) time scale, and the orbital evidence for these objects having originally been comets rather than asteroids will nearly disappear. Statistically, however, a large fraction of the bodies in deep Earth-crossing orbits with semi-major axes ≳ 2.2 AU are likely to be cometary objects in orbits that have not yet diffused into the steady state distribution. For plausible values of the relevant parameters, estimates can be made of the number of cometary Apollo-Amor “asteroids,” the observed number of Earthcrossing active and inactive short period comets, and the production rate of short period comets. These estimates are compatible with other theoretical and observational inferences that suggest the presence of a significant population of Apollo objects that formerly were active comets.


1994 ◽  
Vol 12 (4) ◽  
pp. 695-700 ◽  
Author(s):  
J A Conti ◽  
N Kemeny ◽  
K Seiter ◽  
E Goker ◽  
W Tong ◽  
...  

PURPOSE Trimetrexate (TMTX) is a dihydrofolate reductase inhibitor, which, like methotrexate (MTX), has been shown to potentiate fluorouracil (FU) cytotoxicity by increasing phosphoribosylpyrophosphate (PRPP) levels. We investigated the safety and efficacy of a sequential TMTX/FU/leucovorin (LV) combination. PATIENTS AND METHODS Forty-one patients with advanced gastrointestinal carcinoma (mostly colorectal) received variable doses of TMTX followed 24 hours later by FU/LV (500 mg/m2 of each drug). Almost all patients had received previous chemotherapy. The initial 19 patients were treated on a 3-week-on/1-week-off schedule without any significant toxicity; the remaining patients were treated for 6 consecutive weeks followed by a 2-week rest period. TMTX was escalated in 30-mg/m2 increments from 20 to 110 mg/m2 in separate patient cohorts. When the 110-mg/m2 dose of TMTX was reached, the FU dose was escalated from 500 mg/m2 to 600 mg/m2. RESULTS The partial response (PR) rate in assessable patients with colorectal cancer (all previously treated) was 20% (seven of 35; 95% confidence interval, 7% to 33%), and with other gastrointestinal cancers was one of four patients. Median survival has not been reached with a median follow-up of 13.5 months. The maximum-tolerated dose (MTD) was 110 mg/m2 for TMTX, 500 mg/m2 for FU, and 500 mg/m2 for LV on a 6-weeks-on/2-weeks-off cycle. The principal toxicities were grade 3 or 4 diarrhea, which occurred in 17% of patients, and hypersensitivity reactions, which occurred in 26% of patients. CONCLUSION TMTX can be administered at maximal doses in combination with FU and LV without increasing toxicity. The PR rate of 20% in advanced colorectal carcinoma patients previously treated with chemotherapy is encouraging and merits further study.


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