Organic Tracers from Asphalt in Propolis Produced by Urban Honey Bees, Apis mellifera Linn.

Propolis is a gummy material produced by honey bees to protect their hives and currently has drawn the attention of researchers due to its broad clinical use. It has been reported, based only on observations, that honey bees also collect other non-vegetation substances such as paint or asphalt/tar to make propolis. Therefore, propolis samples were collected from bee hives in Riyadh and Al-Bahah, a natural area, Saudi Arabia to determine their compositional characteristics and possible sources of the neutral organic compounds. The samples were extracted with hexane and analyzed by gas chromatography-mass spectrometry. The results showed that the major compounds were n-alkanes, n-alkenes, methyl n-alkanoates, long chain wax esters, triterpenoids and hopanes. The n-alkanes (ranging from C17 to C40) were significant with relative concentrations varying from 23.8 to 56.8% (mean = 44.9±9.4%) of the total extracts. Their odd carbon preference index (CPI) ranged from 3.6 to 7.7, with a maximum concentration at heptacosane indicating inputs from higher plant vegetation wax. The relative concentrations of the n-alkenes varied from 23.8 to 41.19% (mean = 35.6±5.1%), with CPI = 12.4-31.4, range from C25 to C35 and maximum at tritriacontane. Methyl n-alkanoates, ranged from C12 to C26 as acids, with concentrations from 3.11 to 33.2%(mean = 9.6±9.5%). Long chain wax esters and triterpenoids were minor. The main triterpenoids were α- and β-amyrins, amyrones and amyryl acetates. The presence of hopanes in some total extracts (up to 12.5%) indicated that the bees also collected petroleum derivatives from vicinal asphalt and used that as an additional ingredient to make propolis. Therefore, caution should be taken when considering the chemical compositions of propolis as potential sources of natural products for biological and pharmacological applications. Moreover, beekeepers should be aware of the proper source of propolis in the flight range of their bee colonies

Proboscis Extension Response of Three Apis mellifera Subspecies toward Water and Sugars in Subtropical Ecosystem

The proboscis extension response (PER) assay revealed the responsiveness of three subspecies of the honeybee Apis mellifera [A. m. jemenitica (AMJ), A. m. carnica (AMC), and A. m. ligustica (AML)] to water and different concentrations (0.00001, 0.0001, 0.001, 0.01, 0.1, 0.5, 1.0, and 1.5 M) of three sugars (fructose, glucose, and sucrose) during the summer and fall seasons. The tested bee subspecies showed significantly different PERs to sugar types across the seasons. The water responsiveness of AMJ, a native bee subspecies, was significantly lower than that of AMC and AML, which showed an equally higher water response in both seasons. During the summer season, AMJ and AMC were equally responsive to each sugar type at all tested concentrations. AML was relatively less responsive to glucose at 0.001, 0.001, 0.01, 0.1, 0.5, and 1.0 M than to fructose and sucrose during the summer season. During the fall season, AMJ was equally responsive to glucose and sucrose at all tested concentrations but showed a significantly different response between fructose and sucrose at 0.001, 0.01, 0.1, 0.5, and 1.0 M concentrations. The PER of AMJ to fructose was lower than that of glucose and sucrose. AMC was equally responsive to all tested sugars at all concentrations, and AML showed a differential response between glucose and sucrose at different concentrations during the fall season. The inter-specific species comparisons revealed that all tested subspecies were equally responsive to fructose at all tested concentrations, and AMJ was more responsive to glucose and sucrose than AMC and AML during both seasons. AMC and AML showed no differences in PER to glucose and sucrose in either season. The AMJ, AMC, and AML nectar and pollen foragers showed no significant differences in PER to glucose and sucrose. The AMC nectar foragers were highly responsive to sucrose than pollen foragers at higher sucrose concentrations (0.1, 0.5, 1.0, and 1.5 M). The AML (nectar forager vs. pollen forgers) showed identical PER to sucrose and glucose but a higher response of nectar foragers to high glucose concentrations (0.5, 1.0, and 1.5 M) than pollen foragers. For water responsiveness, AMJ nectar and pollen foragers showed similar PER to water, whereas AMC and AML pollen foragers were significantly more responsive to water than nectar foragers

Impact of Different Storage Regimes on the Levels of Physicochemical Characteristics, Especially Free Acidity in Talh (<i>Acacia gerrardii</i> Benth.) Honey

This study investigates how storage conditions (temperature and duration) may affect the physicochemical parameters, especially free acidity (FA), of Talh honey originating from Acacia gerrardii that have naturally high FA levels. Fresh Talh honey samples were kept at 0, 25, 35, and 45 °C, and analyzed monthly over a period of eight months. The Talh honey was monofloral with 69% A. gerrardii pollen content. The free acidity (FA) of freshly harvested Talh honey samples was higher (93 ± 0.3 meq/kg) than that of standard limits (≤50 meq/kg) and remained stable at 0 °C throughout the storage period. A significantly increase in FA started to occur after storage for 6 months at 25 °C (103 ± 0.2 meq/kg), 2 months at 35 °C (108 ± 0.3 meq/kg), and 1 month at 45 °C (112 ± 0.3 meq/kg). After 8 months of storage, the highest FA level was recorded at 45 °C (159 ± 0.5 meq/kg), followed by 127 ± 0.3 meq/kg at 35 °C, 105 ± 0.2 meq/kg at 25 °C, and 94 ± 0.3 meq/kg at 0 °C. It was found that 0 °C was an appropriate temperature for storing honey for long time. The electrical conductivity (EC) of fresh Talh samples (1.46 ± 0.0 mS/cm) was above the accepted limit (≤0.8 mS/cm), which was slightly increased (non-significant) throughout the storage period under all the storage temperatures. Hydroxymethylfurfural (HMF), diastase activity (DN), and reducing sugars (RSs) showed normal levels only at 0 °C and 25 °C throughout the storage period. However, HMF exceeded the standard limits after the first month at 45 °C (127 ± 9.6 mg/kg) and after the second month at 35 °C (90 ± 23.5 mg/kg), DA decreased below standard limits after the second month (5 ± 1 DN) under 45 °C and after the seventh month under 35 °C (7 ± 2 DN, and RSs decreased below 60% after 2 months under 45 °C and after 6 months at 35 °C. The physicochemical parameters (moisture content, pH, color, and sucrose) were the least affected and were within the standard range throughout the storage period under all the storage temperatures. The levels of FA and EC in fresh Talh samples were higher than the acceptable limits. The moisture content, pH, color, and sucrose content were not affected by storage conditions and remained within the acceptable limits. HMF, DA, and RSs were significantly affected by storage conditions only at 35 and 45 °C. The storage of honey at low temperatures (0 and 25 °C) for up to eight months presented the least amount of changes in the honey, and the honey was unchanged from its fresh status. Honey storage at 35 and 45 °C resulted in significant changes. It is recommended that Talh honey, which normally has high acidity levels, should be stored at temperatures not exceeding 25 °C

Qualité physico-chimique des eaux usées de la station d’épuration de la ville de S’anaa (Yémen)

Dans le souci de reduire le flux des polluants presents dans les eaux usees des agglomerations urbaines de la republique de Yemen, une etude preliminaire a ete entreprise au niveau de la station dfepuration de laville de SfANAA (Yemen). Cette etude avait comme premier objectif dfestimer la pollution physico-chimique globale dans les effluents de la STEP. Il sfagissait dfabord, dfidentifier les sources et les origines de pollution a lfentree de la station, et ensuite dfetudier les performances epuratoires de la station dfepuration. Le but est deramener les teneurs des elements polluants dans lfeau en dessous des valeurs fixees par les normes internationales. Des mesures d'indicateurs de qualite ont ete effectuees pendant six mois sur des echantillonspreleves suivant une frequence de quatre fois par mois. Les rendements epuratoires moyens atteignent 90,99% en DBO5, 89,99% en DCO et 86,4% en MES. L'elimination des orthophosphates est assez elevee avec un rendement moyen de 68%. De maniere globale, les teneurs moyennes en sels restent assez elevees par rapport a la limite tolerable pour un rejet de raffinerie des eaux usees dans un milieu recepteur. Par ailleurs, on arevele une moyenne de 100,5 mg/l (} 12,02) pour les NH4 avec un taux dfabattement de 33% et une moyenne de 2152,75 &fnof;&Ecirc;s/cm (} 151,49) pour les conductivites electriques

Effect of season and behavioral activity on the hypopharyngeal glands of three honey bee Apis mellifera L. races under stressful climatic conditions of central Saudi Arabia

Honey production gains are needed to deal with high demand in Saudi Arabia. The honey bee races are facing stressful hot-arid weather conditions that can affect different aspects of physiology and behavior. The hypopharyngeal glands (HPGs) of honey bees have prominent roles in various social behaviors through their secretions. The measurement of acini size and lipofuscin accumulation indicates the changes in HPGs in response to different factors including weather and behavioral castes. This research aimed to reveal how natural harsh environment of summer and winter can shape the HPGs in foragers and nurses of an indigenous bee race (Apis mellifera jemenitica Ruttner) in comparison with two exotic bee races (Apis mellifera carnica Pollmann and Apis mellifera ligustica Spinola). This study presents new information of significant differences in the HPGs of two behavioral castes (nurses and foragers) of indigenous and exotic bee races under harsh natural environmental conditions. HPGs of foragers have significantly higher lipofuscin accumulation and smaller acini size than nurse bees in all tested races during summer and winter seasons. A strong inverse correlation was found between acini size and lipofuscin accumulation in each race in both seasons. Smaller acini size and lipofuscin accumulation were detected in the HPGs of indigenous bees (foragers and nurses) than exotic bee races during both seasons. The acini size and lipofuscin accumulation were similar between exotic bee races but higher than that of the indigenous bee race

Olfactory associative behavioral differences in three honey bee Apis mellifera L. races under the arid zone ecosystem of central Saudi Arabia

Apis mellifera jemenitica is the indigenous race of honey bees in the Arabian Peninsula and is tolerant to local drought conditions. Experiments were undertaken to determine the differences in associative learning and memory of honey bee workers living in the arid zone of Saudi Arabia, utilizing the proboscis extension response (PER). These experiments were conducted on the indigenous race (A. m. jemenitica) along with two introduced European races (A. m. carnica and A. m. ligustica). The data revealed that A. m. jemenitica is amenable to PER conditioning and may be used in conditioning experiments within the olfactory behavioral paradigm. The results also demonstrated that the three races learn and retain information with different capacities relative to each other during the experimental time periods. Native Arabian bees (A. m. jemenitica) exhibited significantly lower PER percentage during second and third conditioning trials when compared to exotic races. Apis mellifera jemenitica also exhibited reduced memory retention at 2 h and 24 h when compared to A. m. carnica and A. m. ligustica. Therefore, the native Arabian bees were relatively slow learners with reduced memory retention compared to the other two races that showed similar learning and memory retention. Three or five conditioning trials and monthly weather conditions (October and December) had no significant effects on learning and memory in A. m. jemenitica. These results emphasized a novel line of research to explore the mechanism and differences in associative learning as well as other forms of learning throughout the year among bee races in the harsh arid conditions of Saudi Arabia. This is the first study in Saudi Arabia to demonstrate inter-race differences regarding olfactory associative learning between native Arabian bees and two introduced European honey bee races. Keywords: Associative learning, Memory formation, Olfaction, Proboscis extension response, Honey bee races, Saudi Arabi

Cascaded Feature Selection for Enhancing the Performance of Collaborative Recommender System

Most of collaborative recommender systems (CRSs) rely on statistical and data analysis methods for comparing users. However, dealing with them using machine learning techniques seems to be more appropriate. This paper investigates the usage of feature selection and classification methods for CRSs. It suggests building a user model suitable for the classification purpose and proposes a density-based feature selection (DBFS) method based on the rating density for each class. The DBFS reduces the effect of sparsity problem and keeps only users having a dense-feature history. Additionally, a cascaded feature selection method is proposed to pick out a subset of features through a two-layer approach. The first layer applies a classical feature selection method while the second layer applied the DBFS on the output of the first layer. The results show that the performance is gradually improved. The cascaded feature selection yields the best results since it improves the system accuracy, reduces the space and processing complexities, and alleviates the sparsity in two cascaded layers. The achieved improvements by cascaded feature selection as compared to SVM are 6.55 percent, 10.14 percent, and 3.92 percent in terms of accuracy, F-measure and MAE, respectively

Etude physico-chimique et parasitologique des eaux usées destinées à l\'irrigation du périmètre péri-urbain de Fouarat (Kénitra, Maroc).

Les eaux usées de la commune urbaine de Saknia-Fouarat (Kénitra) sont rejetées sans aucun traitement préalable dans le lac Fouarat. Celles-ci sont en partie réutilisées pour l\'irrigation du périmètre péri-urbain de cette zone à vocation agricole. La caractérisation physico-chimique des echantillons a révélé un pH proche de la neutralité et des teneurs en sels relativement importantes. La teneur en chlorures a été de 112,5 mg/l. La charge polluante engendrée par ces effluents urbains a été comprise entre 24 et 124 mg/l pour la DBO5, 110,40 et 418,33 mg/l pour la DCO et entre 350 et 615 mg/l pour les MES. Ces paramètres de pollution ont été relativement faibles, comparativement à la moyenne des concentrations habituellement rencontrées pour les eaux usées urbaines du Maroc. Le rapport DCO/DBO5 a été de 3,48. Cette valeur élevée montre que les eaux usées de la commune urbaine de Saknia-Fouarat sont caractérisées par une pollution inorganique liée, notamment, au rejet des effluents d\'industrie textile raccordée au collecteur. L\'analyse parasitologique montre une forte contamination de ces eaux usées par les oeufs d\'helminthes, soit 32,4 oeufs/l, concentration nettement supérieure aux normes de l\'OMS (Organisation Mondiale de la Santé) relatives aux eaux destinées à l\'irrigation non restrictive des cultures. Les effluents constituent donc un risque environnemental pour la nappe phréatique sous-jacente exploitée par l\'ONEP (Office National de l\'Eau Potable) et pour les eaux du lac Fouarat. En conclusion, le traitement préalable de ces rejets est vivement recommandé, avant leur rejet dans le lac Fouarat pour usage comme eau d\'irrigation des cultures maraîchères.Effluents of the Saknia-Fouarat urban district (Kenitra city) are rejected in the Fouarat Lake without prior treatment. Part of the effluents is used to irrigate the peri-urban perimeter of this agriculturally-rich area. The physico-chemical characterization of these effluents revealed that pH is close to neutrality with relatively high salt content. Chloride concentraqtion was of about 112.5 mg/l. The polluting load generated by these urban effluents was between 24 and 124 mg/l for the BDO5, 110.4 and 418.33 mg/l for the COD and between 350 and 615 mg/l for suspended particles. All these pollutions parameters were relatively low, as compared to the average concentrations of the usual moroccan urban effluents. The calculated COD/BDO5 ratio was 3.48. This high value shows that these wastewaters are characterized by an inorganic pollution related to effluents rejection by the textile industry connected to the main collector. The parasitological characterization of the effluents shows a strong contamination by Helminths parasites eggs (32.4 eggs/l). This concentration largely exceeds the WHO standars concerning water used for non-restrictive irrigation of the cultures. Our results show that effluents used for irrigation cultures in the Fouarat perimeter induce an environmental risk for the subjacent ground water exploited by the ONEP and for the Fouarat Lake water consequently, we highly recommend the treatment of these effluents before their rejection in the Fouarat lake and the in use for irrigation. Keywords: Pollution, eaux usées, physico-chimie, Helminthes, lac Fouarat, MarocAgronomie Africaine Vol. 19 (3) 2007: pp. 251-26

Nectar secretion dynamics of Ziziphus nummularia: A melliferous species of dry land ecosystems

Nectar is used as raw material for the production of honey and as significant reward in the relationship between bees and plants during pollination. Therefore, it is important to investigate its abundance, dynamics and associated governing factors. Weather conditions are known to influence nectar production, and predicted climate changes may be responsible for future declining in total yield from beekeeping activities. We investigated nectar production as total soluble solids (TSS) of well-known species for honey production, Ziziphus nummularia in a hot-arid environment of Saudi Arabia. Data on nectar samples from bagged flowers of different stages during two blooming seasons, 2013 and 2015 were collected on weekly bases, and the data were correlated with weather conditions (temperature, relative humidity, and wind). A significant difference in TSS amount has been obtained, with 1-day old flowers displaying the higher content. TSS production was varied along the different day intervals, for both years, with a peak of production in the afternoon. In our results, nectar production was not correlated to temperature and wind, but was significantly negatively correlated with relative humidity. According to the current and future weather forecasting conditions, understanding of the relationship between weather conditions and nectar availability turned out to be important predictive information that may be interpreted into an economic projection of incomes from beekeeping activities

Ternary diagram showing the compound compositions from petroleum residues, altered products and natural plant wax.

<p>Ternary diagram showing the compound compositions from petroleum residues, altered products and natural plant wax.</p