مجلة الأندلس للعلوم التطبيقية

Types of coral reefs, ecology and biodiversity index from Hadhramout waters, Gulf of Aden, Yemen

2023-02-24T08:31:42-06:00

الملخص EN

The present study was carried out to identify the types of coral reefs; and to highlight the importance and biodiversity index for these species ecology from Hadhramout waters, Gulf of Aden.

Environmental factors were taken only in Burum and Khelf sites: oxygen dissolved, water temperature, pH, salinity, turbidity and sedimentation.

Qualitative survey was done at nine sites in the coastal waters: Husihasa, Jelkha, Burum , Khelf, Al-Quran, Ras Qusiayr, Ras Sharma, Ras Baghashawa and Sharma Island during the period from 2015 until 2016.

At each site, all scleractinian coral species were observed using scuba dives.

The survey of sampling was taken using a 50m belt transect line technique.

The results showed that there were no significant differences (P>0.05) between Burum and Khelf site regarding the environmental factors.

In Burum site, the maximum value of sedimentation which was sunk on coral reef was 7.89 g compared to 5 g in Khelf site.

In all sites, the types of coral reefs found: Turbinaria, Leptoseris, Coscinaraea, Cycloseris (fungia), Acanthastrea, Porites, Parasimplastrea, Montipora, Psmmocora, Anomastraea, Siderastrea, Astreopora, Blastomussa, Favites, Platygyra, Leptoria, Acropora, Goniastrea and Pavona.

Generally, the type of Acropora was more available in all sites compared to other type of coral reefs.

The biodiversity index was the best in Burum ( J= 0.94) followed in Ras Qusair ( J= 0.91) compared to other sites.

From the results, it can conclude that in general the type of Acropora was more obtainable on the Island of Maqrugha (40%) and Yelkha (27%) compared to other sites.

On composite n dividing φ(n)‎ T(n)‎+2

2023-02-24T08:37:38-06:00

الملخص EN

Let φ denote the Eular's Totitient .

For any positive integer n let τ(n) denote the number of its positive divisors .

If T is the set of all composite numbers n > 4 for which n divides φ(n) τ(n) + 2 , we prove that every nЄT has at least five distinct prime factors .

Our result improves that of Yong- Gao and Jin -Hui Fang [4] and of Subbarao [3] .The proofs presented in the paper entirely different from the earlier authors .

تأثيرات إضافة البادئات الحيوية على نمو أسماك Apogon SPP

2023-02-24T08:43:11-06:00

تأثيرات إضافة البادئات الحيوية على نمو أسماك Apogon SPP

دراسة علم الجينات و تطبيقاتها في حياتنا اليومية و علاقتها ببعض الأمراض الوراثية للإنسان

2023-02-24T08:47:27-06:00

الملخص EN

Molecular biology or so-called genetics is a very important modern science in the life of living organisms in general, and in human life in particular, as it is concerned with the study of genes, genetics and subsequent the diversity of organisms.

This research discussed the Molecular biology and their basic components such as chromatids, chromosomes and genes.

Moreover, it's discussed the uses of microbiology in human daily life and its association with very important areas including those related to agricultural, industrial, environmental and medical sciences.

This study also mentioned the symptoms, diagnosis and the treatment methods of Down syndrome, Marfan syndrome, cystic fibrosis and sickle cell disease.