Evaluation of the genetic diversity of wild Salvadora persica ‘Arak’ from Saudi Arabia

Molecular Biology Reports - Assessment of genetic diversity is crucial for efficient selection genotypes in plant breeding and improvement programs. Studies of genetic diversity of S....     

Cytotoxicity and cell death induced by engineered nanostructures (quantum dots and nanoparticles) in human cell lines

JBIC Journal of Biological Inorganic Chemistry - In recent years, the industrial use of ZnO quantum dots (QDs) and nanoparticles (NPs) has risen and there is a high chance of these nanoparticles...     

Beyond the Levant: First Evidence of a Pre-Pottery Neolithic Incursion into the Nefud Desert,Saudi Arabia

Pre-Pottery Neolithic assemblages are best known from the fertile areas of the Mediterranean Levant. The archaeological site of Jebel Qattar 101 (JQ-101), at Jubbah in the southern part of the Nefud Desert of northern Saudi Arabia, contains a large collection of stone tools, adjacent to an Early Holocene palaeolake. The stone tool assemblage contains lithic types, including El-Khiam and Helwan projectile points, which are similar to those recorded in Pre-Pottery Neolithic A and Pre-Pottery Neolithic B assemblages in the Fertile Crescent. Jebel Qattar lies ∼500 kilometres outside the previously identified geographic range of Pre-Pottery Neolithic cultures. Technological analysis of the typologically diagnostic Jebel Qattar 101 projectile points indicates a unique strategy to manufacture the final forms, thereby raising the possibility of either direct migration of Levantine groups or the acculturation of mobile communities in Arabia. The discovery of the Early Holocene site of Jebel Qattar suggests that our view of the geographic distribution and character of Pre-Pottery Neolithic cultures may be in need of revision.     

Phylogenetic and Demographic Insights into Kuhl’s Pipistrelle,Pipistrellus kuhlii,in the Middle East

Kuhl’s pipistrelle is found from Europe and North Africa all of the way to Asia, yet studies have thus far concentrated on the western limit of its distribution. Here we form a multi-marker picture of the diversity of Kuhl’s pipistrelle at a mid point in the Arabian peninsula in an attempt to redress the western sampling bias and to represent a region from which no genetic data has thus far been presented for this species. The three Arabian Cytochrome b haplotypes showed a clear divergence of 19 substitutions from those found in either Europe or North Africa. Molecular dating suggests the Arabian population split from the remaining Kuhl’s somewhere between 0.7 and 1.7 million years before present around the time of a series of aridification events across northern Africa. Well supported lineages within Arabia are typical of that which may be seen after an expansion from multiple Pleistocene refugia, but may also reflect the loss of intermediate haplotypes during historical population fluctuations. A long-term population contraction coincides with climatic changes towards those conditions more typical of contemporary Arabia.     

The indigenous honey bees of Saudi Arabia (Hymenoptera, Apidae, Apis mellifera jemenitica Ruttner): Their natural history and role in beekeeping

Apis mellifera jemenitica Ruttner (= yemenitica auctorum: videEngel 1999) has been used in apiculture throughout the Arabian Peninsula since at least 2000 BC. Existing literature demonstrates that these populations are well adapted for the harsh extremes of the region. Populations of Apis mellifera jemenitica native to Saudi Arabia are far more heat tolerant than the standard races often imported from Europe. Central Saudi Arabia has the highest summer temperatures for the Arabian Peninsula, and it is in this region where only Apis mellifera jemenitica survives, while other subspecies fail to persist. The indigenous race of Saudi Arabia differs from other subspecies in the region in some morphological, biological, and behavioral characteristics. Further taxonomic investigation, as well as molecular studies, is needed in order to confirm whether the Saudi indigenous bee populations represent a race distinct from Apis mellifera jemenitica, or merely an ecotype of this subspecies.     

Occurrence and seasonal prevalence of the coconut mite, Aceria guerreronis (Eriophyidae), and associated arthropods in Oman

The coconut palm is an important crop in the sub arid coastal plain of Dhofar, Oman, for the high demand for its nut water and its use as ornamental plant. Damage of coconut fruits by the eriophyid mite Aceria guerreronis Keifer was first reported in that region in the late 1980s, but background information about the ecology of the pest in Oman was missing. Four surveys were conducted in different seasons from 2008 to 2009, to assess the distribution and prevalence of the coconut mite and its damage as well as the presence of natural enemies. Infestation by the coconut mite was conspicuous on most (99.7 %) palm trees, with 82.5 % damaged fruits. The average (±SE) density of coconut mites per fruit was 750 ± 56; this level of infestation led to the incidence of over 25 % of surface damage on more than half of the fruits. The mite appeared more abundant at the end of the cold season through the summer. No significant differences were observed between infestation levels on local varieties, hybrids and on dwarf varieties. Neoseiulus paspalivorus (De Leon), Cydnoseius negevi (Swirski & Amitai) and Amblyseius largoensis (Muma) were the predatory mites found under the bracts of over 30 % of the coconut fruits and on 68 % of the coconut trees. Considering all sampling dates and all varieties together, average (± SE) phytoseiid density was 1.4 ± 1.19 per fruit. Other mites found in the same habitat as A. guerreronis included the tarsonemids Steneotarsonemus furcatus De Leon and Nasutitarsonemus omani Lofego & Moraes. The pathogenic fungus Hirsutella thompsonii Fisher was rarely found infecting the coconut mite in Dhofar. Other fungal pathogens, namely Cordyceps sp. and Simplicillium sp., were more prevalent.     

The oral health‐related quality of life in edentulous patients treated with Conventional complete dentures

Objective: To compare the oral health‐related quality of life (OHRQoL) between patients with both maxillary and mandibular complete denture and those with either the maxillary or the mandibular complete denture. Background: Satisfaction of denture wearers can be estimated using the OHRQoL questionnaires like the OHIP‐EDENT and the Geriatric Oral Health Assessment Index (GOHAI). Methods: Two questionnaires were used to compare the OHRQoL between edentulous patients who had conventional removable complete denture on both jaws and those who had on either one of the jaws. Result: The age of the participants ranged from 42 to 75 years, with the mean age of 58 ± 8.12 years. The mean OHIP‐EDENT scores were significantly high among those who wore conventional dentures in both jaws (54.12 ± 5.21), compared with the participants who only had denture either on upper or lower jaw (46.52 ± 7.35). It was noticed that the mean GOHAI score was significantly lower (p < 0.05) among participants who had conventional denture on both upper and lower jaw (28.25 ± 3.67), as compared to those who had conventional denture only on one arch (35.12 ± 2.11). Conclusion: Patients with complete dentures in both jaw (Group I) were less satisfied than patients with single complete denture (Group II). The result obtained in this study shows dissatisfaction with conventional dentures among edentulous patients.     

Allelopathic effects of the aqueous extract of Rhazya stricta on growth and metabolism of Salsola villosa

Abstract

Allelopathy is a biological process in which plants synthesize allelochemicals that affect the physiological properties, development and survival of other plants. Experiments were conducted to investigate the allelopathic effect of Rhazya stricta leaf extracts on the germination, early seedling growth and metabolism of Salsola villosa. Aqueous extracts (10, 30 and 50 g/ L) decreased germination and growth by reducing the synthesis of chlorophyll pigments. Leachate treatments induced the antioxidant system by upregulating antioxidant enzyme activities. Additionally, the activities of phenylalanine ammonia lyase and indole acetic acid oxidase were stimulated by exposure to leachate. R. stricta leachates reduced the content of polyunsaturated membrane fatty acids with a concomitant increase in the saturated ones. Unsaturated fatty acids were reduced with the increased concentration of leachate. Phospholipids were also reduced due to leachate, thereby affecting membrane functioning considerably. Aqueous extracts from the leaves of R. stricta restrict the growth and metabolism of S. villosa by hampering membrane functioning and photosynthetic capacity.     

Seasonal population dynamics of dusky cotton bug (Oxycarenus spp.) in transgenic cotton varieties under field conditions

Dusky cotton bug (Oxycarenus spp.) has become a major insect pest for cotton crop in Pakistan. Transgenic cotton varieties provided resistance to a variety of insects pests. But, these are not safe for this emerging potential threat. In present study, nine transgenic cotton varieties (IUB-222, MNH-886, FH-142, CIM-599, A-555, CIM-602, NIAB-777, MNH-786 and Bt-666) were assessed for seasonal population dynamics of dusky cotton bug (DCB) under field conditions. All transgenic varieties showed a differential DCB population over the months and no transgenic variety was free from DCB population throughout the crop duration. DCB population appeared during 3rd week of July and crossed the economic threshold level (10–15 nymph/ adults or both per plant) during August. A substantial increase in DCB population was noted during September-November with its peak population during October, 2014. Among all varieties, three varieties (CIM-599, CIM-602 & IUB-222) showed a significantly lower mean population per plant (37.76, 37.87, 43.84) and two varieties (FH-142, MNH-886) gave highest population (44.71, 46.81), respectively. Correlation matrix revealed that low temperature and high humidity were promoting the DCB population. Cluster analysis revealed interesting findings that IUB-222 with least population fall in a cluster where other two varieties (FH-142 & MNH-886) possessed highest population. Moreover, two varieties (CIM-599 & CIM-602) with least population fall in second cluster regarding DCB population. These findings would be helpful for the farmers to select the varieties that showed relatively higher resistance towards DCB population and to adopt proper management strategies keeping in view the trend of DCB population during the crop season.