Zeitschriften und Ausgaben

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Volumen 9 (2022): Heft 2 (July 2022)

Volumen 9 (2022): Heft 1 (March 2022)

Volumen 8 (2021): Heft 3 (November 2021)

Volumen 8 (2021): Heft 2 (July 2021)

Volumen 8 (2021): Heft 1 (March 2021)

Volumen 7 (2020): Heft 3 (November 2020)

Volumen 7 (2020): Heft 2 (July 2020)

Volumen 7 (2020): Heft 1 (March 2020)

Volumen 6 (2019): Heft 2 (December 2019)

Volumen 6 (2019): Heft 1 (March 2019)

Volumen 5 (2018): Heft 2 (December 2018)

Volumen 5 (2018): Heft 1 (March 2018)

Volumen 4 (2017): Heft 1 (March 2017)

Volumen 3 (2016): Heft 1 (March 2016)

Volumen 2 (2015): Heft 1 (December 2015)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2603-347X
Erstveröffentlichung
15 Dec 2015
Erscheinungsweise
1 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 7 (2020): Heft 2 (July 2020)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2603-347X
Erstveröffentlichung
15 Dec 2015
Erscheinungsweise
1 Hefte pro Jahr
Sprachen
Englisch

Suche

13 Artikel
Uneingeschränkter Zugang

Editorial Note: Madara Plateau - amazinng nature and ancient history

Online veröffentlicht: 10 Aug 2020
Seitenbereich: I - III

Zusammenfassung

Uneingeschränkter Zugang

Chemical Composition of Algerian Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. (Lamiaceae) Essential Oils from the Aures Region

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 1 - 14

Zusammenfassung

Abstract

This study was aimed to determine the chemical composition of essential oils obtained from aerial parts of Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. collected in the Aures region of Algeria. Essential oils were extracted by steam distillation method and analyzed using GC-MS and GC-FID techniques. Thirty-five (35) and twenty-nine (29) components were identified respectively in T. algeriensis and M. vulgare essential oils to represent respectively 94.8% and 75.7% of the total oil composition. The main compounds of T. algeriensis oil were germacrene D (29.6%), β-caryophyllene (11.0%), E-β-farnesene (7.8%), bicyclogermacrene (4.4%) and δ-cadinene (4.0%), while, β-bisaboene (36.3%), β-caryophyllene (7.8%), phytol (6.2%), nonacosane (4.0%) and heptacosane (3.3%) were the main components of M. vulgare oil. The richness of these two oils in germacrene D and β-bisaboene respectively could suggest a new bioactivity.

Schlüsselwörter

  • Essential oil
  • germacrene D and β-bisaboene
Uneingeschränkter Zugang

Evaluation of phenolic contents and antioxidant activities of some medicinal plants growing in Algerian Aurès Mountains

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 15 - 30

Zusammenfassung

Abstract

The objective of this study is to evaluate the antioxidant activities of six medicinal plants growing in Algerian Aurès Mountains. Total phenolic and flavonoids contents were measured using colorimetric methods, and the antioxidant capacities were evaluated using the DPPH radical scavenging and β-carotene bleaching tests. Juniperus phoenica L. had significantly the higher total phenolic compounds (53.6±3.86 mg GAE.g−1 DM) (p<0.05); followed by Romarinus officinalis L. (26.1±3.15 mg GAE.g−1 DM) and Artemisia campestris L. (20.5±1.99 mg GAE.g−1 DM). Artemisia campestris L. had significantly the higher flavonoid contents (11.1±0.56 mg QE.g−1 DM) than other studied plants (p<0.05). The best antiradical activity was observed in Thymus algeriensis extracts (EC50=11.1±0.33 µg.ml−1) and Romarinus officinalis L. (EC50=15.3±0.9 µg.ml−1). β-carotene bleaching test showed that the herbs’ phenolic compounds Antioxidant Activity (AA%) value was found in the range of 64-84%, whereas that of the standard antioxidant ascorbic acid was 51±2.4%. The present results indicate that medicinal plants from the Algerian Aurès mountains could be explored in food and pharmaceutical industries for development of natural’s antioxidant agents.

Schlüsselwörter

  • Medicinal plants
  • phenolic compounds
  • oxidative stress
  • antioxidant activity
Uneingeschränkter Zugang

Chemical composition, antimicrobial activity and chromosome number of Hertia cheirifolia L. from Algeria

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 31 - 43

Zusammenfassung

Abstract

The aims of this work are to investigate the chemical composition, the antibacterial activity of the essential oil and the chromosome numbers of two populations of Hertia cheirifolia. The samples were collected in the flowering stage, in eastern Algeria locality. The aerial parts of H. cheirifolia were submitted to a hydro-distillation. GC and GC / MS analysed the chemical compositions of the obtained essential oils. The antibacterial activity of essential oils was evaluated using the disks diffusion method against ten bacterial strains. For karyotypic analysis, the squashing method is used. Fifty-eight compounds representing 98.93% of the total oil were identified in H. cheirifolia. The chemical composition is dominated by the presence of major products, α-pinene (48.49 - 53.85%) and Germacrene-D (2.64 - 12.66%). Two distinct chemical breeds were identified, the α-pinene-spathulenol of Batna population, and the α-pinene-germacrene-D of Setif population. The essential oil of H. cheirifolia has a moderate activity against bacteria tested. In contrast, the strains E. coli ATCC 25922, P. syringae ATCC 53543 and E. fecalis ATCC 49452 are resistant to H. cheirifolia essential oils. The observations of root cells meristematic at metaphase of H. cheirifolia gave a diploid chromosome number 2n = 2x = 20, with a basic chromosome number (x= 10).

Schlüsselwörter

  • essential oil
  • antibacterial activity
  • chromosome number
  • Algeria
Uneingeschränkter Zugang

Role of exogenous application of abscisic acid ABA in drought tolerance and evaluation of antioxidant activity in durum wheat genotypes

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 44 - 60

Zusammenfassung

Abstract

Survival under stressful circumstance depends on the plant’s aptitude to perceive the stimulus, generate and transmit the signals, and initiate various physiological and biochemical changes. This study aims to evaluate the exogenous seed treatment by abscissic acid (ABA) in durum wheat genotypes under water stress conditions. In this investigation, a hydroponic experiment was conducted to evaluate the potential role of exogenously applied abscicic acid in improving drought tolerance in wheat. Three contrasting wheat genotypes were used in this work: Hoggar, Hedba3 and Sigus. Two levels of water stress were induced: 2h and 4h, the aim of this work was to evaluate the action of seed exogenous treatment with ABA for 8 and 16h on physiological and biochemical parameters like stomatal resistance, antioxidant enzyme activity and quantification of ABA by HPLC. The results showed that water stress caused a decrease in endogenous ABA concentration in the roots of the stressed varieties with the exception of Hedba3. Furthermore, after ABA treatment for 16h, the two genotypes Hedba 3 and Hogar showed a higher accumulation of this phytohormone, compared to Sigus variety which marks a decrease in this concentration and which can be explained by the consumption of the ABA in the defense against the ROS.

Schlüsselwörter

  • Wheat
  • drought
  • abscicic acid
  • antioxydants enzyms
Uneingeschränkter Zugang

Effect of seasonal variations on the content of some osmolytes of Aleppo pine and holm oak

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 61 - 73

Zusammenfassung

Abstract

The forest of Chettaba is of great ecological importance for the Constantine region. It is characterized by a very heterogeneous forest cover, the dominance of forest species (Pinus halepensis and Quercus ilex) and an advanced stage of degradation. Vegetation in this region reflects the climate. The summer is dry and hot while the winter is rainy and cold. Indeed, the combination of rain and temperature directly influences the physiology of the vegetation in this forest. The main objective of this work is to characterize the different responses of Aleppo pine and holm oak seedlings and to specify the biochemical variations under the seasonal effect. Biochemical assays of proline, soluble sugars, total proteins and chlorophyll were quantified in the different organs of two species for each of the years 2018–2019. The results obtained show very significant accumulation of total soluble sugars and proline in holm oak and Aleppo pine leaves compared to stems and roots during the winter season (520 ± 20 and 370 ± 17.98 µmol/mg DM respectively). Contrary to the previous results, the highest total protein levels were recorded during the summer with levels of 0.666 ± 0.116 and 1,626 ± 0.107 mg/g FM. Parallel to the accumulation of these three solutes, a gradual decrease in the chlorophyll pigment content was recorded in winter and summer.

Schlüsselwörter

  • soluble sugar
  • proline
  • total protein
  • chlorophyll pigment
Uneingeschränkter Zugang

Phytochemical profiles of Iris unguicularis Poir. with antioxidant, antibacterial, and anti-Alzheimer activities

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 74 - 87

Zusammenfassung

Abstract

Phytochemical investigation of medicinally important plants has gained great attention, lately. This study aims to investigate the phytochemical constituents of the partitioned extracts (ethyl acetate (AI), dichloromethane (CI) and n-butanol (BI)) derived from the 70% ethanol extract of the rhizomes (RI) of Iris unguicularis Poir. an Algerian-Tunisian endemic plant and to evaluate their biological activities. Seventy constituents of these partitioned extracts were qualitatively characterized by liquid chromatography ion trap time of flight mass spectrometry (LC-MS-IT-TOF) technique. Moreover, quantitative screening of phenolic acids and flavonoids in the studied extracts was accomplished by a previously validated LC-MS/MS method. It was determined that, AI and CI, which were the richest extracts in terms of phytochemical content, showed high antioxidant and antibacterial activities in parallel with their identified constituents, while AI extract was rich in protocatechuic (1080.4 µg analyte/g), 4-OH-benzoic (2218.2 µg/g), syringic (1218.6 µg/g) and pcoumaric (1071.2 µg/g) acids, CI extract has been found to be rich in naringenin (1453.4 µg/g) and ferulic acid (1088.4 µg/g). These results revealed and confirmed the importance of the species and especially the genus rhizomes which have largely been used in folk medicine for the treatment of many diseases. However, all extracts of this endemic plant were inactive at all concentration against acetyl-and butyrylcholinesterase enzymes.

Schlüsselwörter

  • Poir.
  • rhizomes
  • phenolic compounds
  • biological activities
  • LC-MS/MS
  • LCMS-IT-TOF
Uneingeschränkter Zugang

Impacts of anthropogenic pressure on the degradation of the forest of Doui Thabet (Saida, Western Algeria) in the context of the restoration

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 88 - 97

Zusammenfassung

Abstract

The forest of Doui Thabet is one of the forests of the Mounts of Saida (Western Algeria) which is experiencing a dynamic regressive. Located in the semi-arid bioclimatic stage, it is located at the edge of two phytogeographic sub-sectors: atlas Tellien Oranais (O3) and high plateau subsector (H1). Among the factors that threaten to curb this fragile and weakened ecosystem, in addition to drought and climate aridity and which has become a structural ecological phenomenon; the overgrazing is also a major limiting factor. This current study provides a qualitative and quantitative assessment of anthropogenic pressure exerted in this area zone. The methodology adopted in this study is that of Le Houerou (1969) and Montoya (1983), which it is based on the calculation of the annual needs of the herd in forage units, the estimate of the feed potential of production, the coefficient of overgrazing and in addition to the anthropogenic pressure index. The result of the forage balance in the forest rangelands of the studied area has a forage deficit (overload) of (96.64%) (a sylvopastoral imbalance), in addition to that, the coefficient of overgrazing is (92.3%) and the anthropogenic pressure index is very high (28). The conservation and the restoration of this area is a major concern in the face of global changes, taking into account their mode of reproduction and their dynamics, for the development of restoration strategies and more effective ways of protection.

Schlüsselwörter

  • Doui Thabet
  • forest rangelands
  • anthropogenic pressure index
  • sylvopastoral imbalance
  • restoration
Uneingeschränkter Zugang

Impact of ecological restoration techniques on the dynamics of degraded ecosystems of the mounts of Saida: Case of the forests of Doui Thabet (West Algeria)

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 98 - 121

Zusammenfassung

Abstract

The aim of the present study aims to establish the impact of different restoration techniques (soil and vegetation works) of five pioneer species of the Doui Thabet forest (Mounts of Saida, West of Algeria): Pinus halepensis, Pistacia lentiscus., Tetraclinis articulata, Juniperus oxycedru,. and Stipa capensis (= S. tenacissima L.) between 2018 and 2020. An experimental field device covering an area of 1 ha has been installed in the Doui Thabet forest in a Pinus halepensis massive more than 80 years old. The following work was carried out: mechanical grinding of the vegetation (chopping), turning (scarification of soil) to a depth of 10 cm, tillage (Deep ploughing) to a depth of 20 cm, controlled burning of branches, clearing of Stipa capensis, seedlings planted in different seasons for certain species (Stipa capensis = S. tenacissima L.), monitoring of stump rejections and natural sowing. The sowing result varies according to the species and restoration techniques, it is high for Pinus halepensis and Stipa capensis. It is low for Tetraclinis articulata and Juniperus oxycedrus and none for Pistacia lentiscus while for Stipa capensis it is quite high when planted in autumn compared to spring. Turning and burning have proven to be the most abundant treatments for regeneration and growth. Grinding has medium seedling density and growth, while deep tillage and natural sowing showed low seedling density and growth.

Schlüsselwörter

  • Doui Thabet
  • dynamics
  • ecological restoration
  • ecosystem degradation
  • techniques
Uneingeschränkter Zugang

Investigations of the late Quaternary morphotectonic evolution of the Balkan Peninsula East Part

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 122 - 132

Zusammenfassung

Abstract

The East Balkan Peninsula Area was a part from the Tethys Ocean until 72 000 000 years. The pre Maestrichtian geologic-tectonic pattern of cockle of the East Balkan Peninsula Area wasn’t built on the Europe Continental Massif. The modern East Balkan Peninsula Relief is forming during the Late Quaternary time. The East Balkan Peninsula Margin coincides with the border between the Bulgarian and Moesian Continental Microplates from the west and the Black Sea Oceanic Microplatte to the east. This border present the Neo Europe West Passive Continental Margin in the area of the last Tethys Oceanic Fragment – it Black Sea Oceanic Gulf.

Schlüsselwörter

  • continental fragment
  • New Europe
  • Late Quaternary relief
Uneingeschränkter Zugang

New ideas about the Balkan peninsula East Part morphotectonics

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 133 - 144

Zusammenfassung

Abstract

The article introduces the results of the author’s new investigations about the origin, Quaternary morphotectonic evolution and the modern morphostructure of the Bulgarian Continental Microplate in the eastern part of Balkan Peninsula. The research was realized on a base of the contemporary Plate tectonic study principia by means of the morphostructural analysis apply. It was provided the principal relief building role of the regional mosaic pattern and the listric faulting in the Balkan Peninsula East Part.

Schlüsselwörter

  • Tethys Ocean Closing
  • Intra Mediterranean Archipelago
  • New Europe Mosaic Continental Massif
  • Gondvana\Europe Transcontinental Collision
  • Quaternary Relief Building
Uneingeschränkter Zugang

Palaeoenvironmental interpretation of the structures and textures of the Miocene sediments in the Strymon basin, Northern Greece

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 145 - 157

Zusammenfassung

Abstract

For the purpose of lithological analysis the Miocene sedimentary sequences in the Strymon basin, Northern Greece have been observed and described in detail concluding in subdividing them into a new lithostratigraphic shape. These investigations in this analysis, through the study of data of the sedimentary structures and textures led to the interpretation of the depositional environments in the Miocene basin.

Schlüsselwörter

  • Miocene sediments
  • Palaeoenvironmental interpretation
  • sedimentary structures
  • Strymon basin
  • Northern Greece
Uneingeschränkter Zugang

The Demographic Problem - one of the Main Problems of Contemporary

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 158 - 171

Zusammenfassung

Abstract

The present study attempts to analyze the essential characteristics of the global problems in the development of human society at the present stage and to highlight the place of the demographic problem as an objective factor for the existence of modern civilization. It clarifies the criteria for determining a problem as a global one and makes classification from a geographic point of view. It identifies the causes for the demographic problem, analyses and specifies its different dimensions at the global, regional and national levels.

Schlüsselwörter

  • global geographic problems
  • demographic problem
13 Artikel
Uneingeschränkter Zugang

Editorial Note: Madara Plateau - amazinng nature and ancient history

Online veröffentlicht: 10 Aug 2020
Seitenbereich: I - III

Zusammenfassung

Uneingeschränkter Zugang

Chemical Composition of Algerian Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. (Lamiaceae) Essential Oils from the Aures Region

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 1 - 14

Zusammenfassung

Abstract

This study was aimed to determine the chemical composition of essential oils obtained from aerial parts of Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. collected in the Aures region of Algeria. Essential oils were extracted by steam distillation method and analyzed using GC-MS and GC-FID techniques. Thirty-five (35) and twenty-nine (29) components were identified respectively in T. algeriensis and M. vulgare essential oils to represent respectively 94.8% and 75.7% of the total oil composition. The main compounds of T. algeriensis oil were germacrene D (29.6%), β-caryophyllene (11.0%), E-β-farnesene (7.8%), bicyclogermacrene (4.4%) and δ-cadinene (4.0%), while, β-bisaboene (36.3%), β-caryophyllene (7.8%), phytol (6.2%), nonacosane (4.0%) and heptacosane (3.3%) were the main components of M. vulgare oil. The richness of these two oils in germacrene D and β-bisaboene respectively could suggest a new bioactivity.

Schlüsselwörter

  • Essential oil
  • germacrene D and β-bisaboene
Uneingeschränkter Zugang

Evaluation of phenolic contents and antioxidant activities of some medicinal plants growing in Algerian Aurès Mountains

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 15 - 30

Zusammenfassung

Abstract

The objective of this study is to evaluate the antioxidant activities of six medicinal plants growing in Algerian Aurès Mountains. Total phenolic and flavonoids contents were measured using colorimetric methods, and the antioxidant capacities were evaluated using the DPPH radical scavenging and β-carotene bleaching tests. Juniperus phoenica L. had significantly the higher total phenolic compounds (53.6±3.86 mg GAE.g−1 DM) (p<0.05); followed by Romarinus officinalis L. (26.1±3.15 mg GAE.g−1 DM) and Artemisia campestris L. (20.5±1.99 mg GAE.g−1 DM). Artemisia campestris L. had significantly the higher flavonoid contents (11.1±0.56 mg QE.g−1 DM) than other studied plants (p<0.05). The best antiradical activity was observed in Thymus algeriensis extracts (EC50=11.1±0.33 µg.ml−1) and Romarinus officinalis L. (EC50=15.3±0.9 µg.ml−1). β-carotene bleaching test showed that the herbs’ phenolic compounds Antioxidant Activity (AA%) value was found in the range of 64-84%, whereas that of the standard antioxidant ascorbic acid was 51±2.4%. The present results indicate that medicinal plants from the Algerian Aurès mountains could be explored in food and pharmaceutical industries for development of natural’s antioxidant agents.

Schlüsselwörter

  • Medicinal plants
  • phenolic compounds
  • oxidative stress
  • antioxidant activity
Uneingeschränkter Zugang

Chemical composition, antimicrobial activity and chromosome number of Hertia cheirifolia L. from Algeria

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 31 - 43

Zusammenfassung

Abstract

The aims of this work are to investigate the chemical composition, the antibacterial activity of the essential oil and the chromosome numbers of two populations of Hertia cheirifolia. The samples were collected in the flowering stage, in eastern Algeria locality. The aerial parts of H. cheirifolia were submitted to a hydro-distillation. GC and GC / MS analysed the chemical compositions of the obtained essential oils. The antibacterial activity of essential oils was evaluated using the disks diffusion method against ten bacterial strains. For karyotypic analysis, the squashing method is used. Fifty-eight compounds representing 98.93% of the total oil were identified in H. cheirifolia. The chemical composition is dominated by the presence of major products, α-pinene (48.49 - 53.85%) and Germacrene-D (2.64 - 12.66%). Two distinct chemical breeds were identified, the α-pinene-spathulenol of Batna population, and the α-pinene-germacrene-D of Setif population. The essential oil of H. cheirifolia has a moderate activity against bacteria tested. In contrast, the strains E. coli ATCC 25922, P. syringae ATCC 53543 and E. fecalis ATCC 49452 are resistant to H. cheirifolia essential oils. The observations of root cells meristematic at metaphase of H. cheirifolia gave a diploid chromosome number 2n = 2x = 20, with a basic chromosome number (x= 10).

Schlüsselwörter

  • essential oil
  • antibacterial activity
  • chromosome number
  • Algeria
Uneingeschränkter Zugang

Role of exogenous application of abscisic acid ABA in drought tolerance and evaluation of antioxidant activity in durum wheat genotypes

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 44 - 60

Zusammenfassung

Abstract

Survival under stressful circumstance depends on the plant’s aptitude to perceive the stimulus, generate and transmit the signals, and initiate various physiological and biochemical changes. This study aims to evaluate the exogenous seed treatment by abscissic acid (ABA) in durum wheat genotypes under water stress conditions. In this investigation, a hydroponic experiment was conducted to evaluate the potential role of exogenously applied abscicic acid in improving drought tolerance in wheat. Three contrasting wheat genotypes were used in this work: Hoggar, Hedba3 and Sigus. Two levels of water stress were induced: 2h and 4h, the aim of this work was to evaluate the action of seed exogenous treatment with ABA for 8 and 16h on physiological and biochemical parameters like stomatal resistance, antioxidant enzyme activity and quantification of ABA by HPLC. The results showed that water stress caused a decrease in endogenous ABA concentration in the roots of the stressed varieties with the exception of Hedba3. Furthermore, after ABA treatment for 16h, the two genotypes Hedba 3 and Hogar showed a higher accumulation of this phytohormone, compared to Sigus variety which marks a decrease in this concentration and which can be explained by the consumption of the ABA in the defense against the ROS.

Schlüsselwörter

  • Wheat
  • drought
  • abscicic acid
  • antioxydants enzyms
Uneingeschränkter Zugang

Effect of seasonal variations on the content of some osmolytes of Aleppo pine and holm oak

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 61 - 73

Zusammenfassung

Abstract

The forest of Chettaba is of great ecological importance for the Constantine region. It is characterized by a very heterogeneous forest cover, the dominance of forest species (Pinus halepensis and Quercus ilex) and an advanced stage of degradation. Vegetation in this region reflects the climate. The summer is dry and hot while the winter is rainy and cold. Indeed, the combination of rain and temperature directly influences the physiology of the vegetation in this forest. The main objective of this work is to characterize the different responses of Aleppo pine and holm oak seedlings and to specify the biochemical variations under the seasonal effect. Biochemical assays of proline, soluble sugars, total proteins and chlorophyll were quantified in the different organs of two species for each of the years 2018–2019. The results obtained show very significant accumulation of total soluble sugars and proline in holm oak and Aleppo pine leaves compared to stems and roots during the winter season (520 ± 20 and 370 ± 17.98 µmol/mg DM respectively). Contrary to the previous results, the highest total protein levels were recorded during the summer with levels of 0.666 ± 0.116 and 1,626 ± 0.107 mg/g FM. Parallel to the accumulation of these three solutes, a gradual decrease in the chlorophyll pigment content was recorded in winter and summer.

Schlüsselwörter

  • soluble sugar
  • proline
  • total protein
  • chlorophyll pigment
Uneingeschränkter Zugang

Phytochemical profiles of Iris unguicularis Poir. with antioxidant, antibacterial, and anti-Alzheimer activities

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 74 - 87

Zusammenfassung

Abstract

Phytochemical investigation of medicinally important plants has gained great attention, lately. This study aims to investigate the phytochemical constituents of the partitioned extracts (ethyl acetate (AI), dichloromethane (CI) and n-butanol (BI)) derived from the 70% ethanol extract of the rhizomes (RI) of Iris unguicularis Poir. an Algerian-Tunisian endemic plant and to evaluate their biological activities. Seventy constituents of these partitioned extracts were qualitatively characterized by liquid chromatography ion trap time of flight mass spectrometry (LC-MS-IT-TOF) technique. Moreover, quantitative screening of phenolic acids and flavonoids in the studied extracts was accomplished by a previously validated LC-MS/MS method. It was determined that, AI and CI, which were the richest extracts in terms of phytochemical content, showed high antioxidant and antibacterial activities in parallel with their identified constituents, while AI extract was rich in protocatechuic (1080.4 µg analyte/g), 4-OH-benzoic (2218.2 µg/g), syringic (1218.6 µg/g) and pcoumaric (1071.2 µg/g) acids, CI extract has been found to be rich in naringenin (1453.4 µg/g) and ferulic acid (1088.4 µg/g). These results revealed and confirmed the importance of the species and especially the genus rhizomes which have largely been used in folk medicine for the treatment of many diseases. However, all extracts of this endemic plant were inactive at all concentration against acetyl-and butyrylcholinesterase enzymes.

Schlüsselwörter

  • Poir.
  • rhizomes
  • phenolic compounds
  • biological activities
  • LC-MS/MS
  • LCMS-IT-TOF
Uneingeschränkter Zugang

Impacts of anthropogenic pressure on the degradation of the forest of Doui Thabet (Saida, Western Algeria) in the context of the restoration

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 88 - 97

Zusammenfassung

Abstract

The forest of Doui Thabet is one of the forests of the Mounts of Saida (Western Algeria) which is experiencing a dynamic regressive. Located in the semi-arid bioclimatic stage, it is located at the edge of two phytogeographic sub-sectors: atlas Tellien Oranais (O3) and high plateau subsector (H1). Among the factors that threaten to curb this fragile and weakened ecosystem, in addition to drought and climate aridity and which has become a structural ecological phenomenon; the overgrazing is also a major limiting factor. This current study provides a qualitative and quantitative assessment of anthropogenic pressure exerted in this area zone. The methodology adopted in this study is that of Le Houerou (1969) and Montoya (1983), which it is based on the calculation of the annual needs of the herd in forage units, the estimate of the feed potential of production, the coefficient of overgrazing and in addition to the anthropogenic pressure index. The result of the forage balance in the forest rangelands of the studied area has a forage deficit (overload) of (96.64%) (a sylvopastoral imbalance), in addition to that, the coefficient of overgrazing is (92.3%) and the anthropogenic pressure index is very high (28). The conservation and the restoration of this area is a major concern in the face of global changes, taking into account their mode of reproduction and their dynamics, for the development of restoration strategies and more effective ways of protection.

Schlüsselwörter

  • Doui Thabet
  • forest rangelands
  • anthropogenic pressure index
  • sylvopastoral imbalance
  • restoration
Uneingeschränkter Zugang

Impact of ecological restoration techniques on the dynamics of degraded ecosystems of the mounts of Saida: Case of the forests of Doui Thabet (West Algeria)

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 98 - 121

Zusammenfassung

Abstract

The aim of the present study aims to establish the impact of different restoration techniques (soil and vegetation works) of five pioneer species of the Doui Thabet forest (Mounts of Saida, West of Algeria): Pinus halepensis, Pistacia lentiscus., Tetraclinis articulata, Juniperus oxycedru,. and Stipa capensis (= S. tenacissima L.) between 2018 and 2020. An experimental field device covering an area of 1 ha has been installed in the Doui Thabet forest in a Pinus halepensis massive more than 80 years old. The following work was carried out: mechanical grinding of the vegetation (chopping), turning (scarification of soil) to a depth of 10 cm, tillage (Deep ploughing) to a depth of 20 cm, controlled burning of branches, clearing of Stipa capensis, seedlings planted in different seasons for certain species (Stipa capensis = S. tenacissima L.), monitoring of stump rejections and natural sowing. The sowing result varies according to the species and restoration techniques, it is high for Pinus halepensis and Stipa capensis. It is low for Tetraclinis articulata and Juniperus oxycedrus and none for Pistacia lentiscus while for Stipa capensis it is quite high when planted in autumn compared to spring. Turning and burning have proven to be the most abundant treatments for regeneration and growth. Grinding has medium seedling density and growth, while deep tillage and natural sowing showed low seedling density and growth.

Schlüsselwörter

  • Doui Thabet
  • dynamics
  • ecological restoration
  • ecosystem degradation
  • techniques
Uneingeschränkter Zugang

Investigations of the late Quaternary morphotectonic evolution of the Balkan Peninsula East Part

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 122 - 132

Zusammenfassung

Abstract

The East Balkan Peninsula Area was a part from the Tethys Ocean until 72 000 000 years. The pre Maestrichtian geologic-tectonic pattern of cockle of the East Balkan Peninsula Area wasn’t built on the Europe Continental Massif. The modern East Balkan Peninsula Relief is forming during the Late Quaternary time. The East Balkan Peninsula Margin coincides with the border between the Bulgarian and Moesian Continental Microplates from the west and the Black Sea Oceanic Microplatte to the east. This border present the Neo Europe West Passive Continental Margin in the area of the last Tethys Oceanic Fragment – it Black Sea Oceanic Gulf.

Schlüsselwörter

  • continental fragment
  • New Europe
  • Late Quaternary relief
Uneingeschränkter Zugang

New ideas about the Balkan peninsula East Part morphotectonics

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 133 - 144

Zusammenfassung

Abstract

The article introduces the results of the author’s new investigations about the origin, Quaternary morphotectonic evolution and the modern morphostructure of the Bulgarian Continental Microplate in the eastern part of Balkan Peninsula. The research was realized on a base of the contemporary Plate tectonic study principia by means of the morphostructural analysis apply. It was provided the principal relief building role of the regional mosaic pattern and the listric faulting in the Balkan Peninsula East Part.

Schlüsselwörter

  • Tethys Ocean Closing
  • Intra Mediterranean Archipelago
  • New Europe Mosaic Continental Massif
  • Gondvana\Europe Transcontinental Collision
  • Quaternary Relief Building
Uneingeschränkter Zugang

Palaeoenvironmental interpretation of the structures and textures of the Miocene sediments in the Strymon basin, Northern Greece

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 145 - 157

Zusammenfassung

Abstract

For the purpose of lithological analysis the Miocene sedimentary sequences in the Strymon basin, Northern Greece have been observed and described in detail concluding in subdividing them into a new lithostratigraphic shape. These investigations in this analysis, through the study of data of the sedimentary structures and textures led to the interpretation of the depositional environments in the Miocene basin.

Schlüsselwörter

  • Miocene sediments
  • Palaeoenvironmental interpretation
  • sedimentary structures
  • Strymon basin
  • Northern Greece
Uneingeschränkter Zugang

The Demographic Problem - one of the Main Problems of Contemporary

Online veröffentlicht: 10 Aug 2020
Seitenbereich: 158 - 171

Zusammenfassung

Abstract

The present study attempts to analyze the essential characteristics of the global problems in the development of human society at the present stage and to highlight the place of the demographic problem as an objective factor for the existence of modern civilization. It clarifies the criteria for determining a problem as a global one and makes classification from a geographic point of view. It identifies the causes for the demographic problem, analyses and specifies its different dimensions at the global, regional and national levels.

Schlüsselwörter

  • global geographic problems
  • demographic problem

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