760 research outputs found
Customized physical and structural features of phosphate-based glass-ceramics: role of ag nanoparticles and ho3+ impurities
The effects of silver nanoparticles (Ag NPs) embedment on the physical and structural characteristics of the holmium ions (Ho3+) activated phosphate-based glass-ceramics were assessed. Two series of such glass-ceramics were prepared using the melt-quenching and characterized. In the first series, the Ag NPs were nucleated from the incorporated AgCl via the redox process. In the second series, the pure Ag nanopowder was directly added. The overall properties of these glass-ceramics were strongly sensitive to the cooling procedure and NPs addition strategies, leading to different density and refractive index modifications in the two series. The recorded O1s XPS peaks were exploited to determine the bridging to non-bridging oxygen ratios in the studied glass-ceramics network that enabled to unfold the differences in the observed inferences. A compelling correlation among various attributes in the achieved glass-ceramics was established. Briefly, the overall traits of the proposed glass-ceramics were tailored by regulating the preparation conditions
Notes on the Nesting Biology of the Small Carpenter Bee Ceratina smaragdula (Hymenoptera: Apidae) in Northwestern Pakistan
The nesting biology and some foraging activities of the familiar, brilliant metallic green, small carpenter bee Ceratina (Pithitis) smaragdula (F.) (Hymenoptera: Apidae) is documented from the northwestern-most extent of its natural distribution, as the species is a potentially important pollinator of leguminous and cucurbit crops in the region. Numerous nests around the village of Ismaila, Swabi, Khyber Pakhtunkhwa Province, Pakistan, were observed and sampled from Jun through Aug 2012. Nest details were recorded and foraging times on various floral species were documented, with bees preferentially nesting in wooden stalks of Ravenna grass (Saccharum ravennae L.; Poales: Poaceae), life cycles lasting 28 to 32 d, and conditions offering the potential for easy management. The importance of such studies on wild bees in Pakistan is stressed, as are the development of biotic surveys on bees and the training of regional melittologists, coupled with outreach activities.
Resumen
La biología de la anidación y algunas actividades de forrajeo de la pequeña abeja carpintera Ceratina (Pithitis) smaragdula (F.) (Hymenoptera: Apidae) de tipo familiar y brillante color verde metálico está documentado desde el punto mas noroeste de su distribución natural, ya que la especie es potencialmente un importante polinizador de legumbres y cucurbitáceas en la región. Se observaron numerosos nidos alrededor del pueblo de Ismaila, Swabi, Khyber Pakhtunkhwa Provincia, Pakistán, y se tomaron muestras desde junio hasta agosto del 2012. Los detalles de la anidación fueron registrados y se documentaron los tiempos de forrajeo sobre diversas especies florales, con las abejas preferentemente anidando en los tallos de madera de pasto de Rávena (Saccharum ravennae L.; Poales: Poaceae), los ciclos de vida duran de 28 a 32 dias, y las condiciones que ofrecen el potencial para un fácil manejo. Se destaca la importancia de este tipo de estudio sobre las abejas silvestres en Pakistán, igual que el desarrollo de sondeos bióticos sobre las abejas y la formación de melitólogos regionales, junto con actividades de extensión
Thermal Alkali Vapour Spectroscopy: Buffer Gas Enhanced K Systems and Magneto-Optical Rb Applications
We present experimental and theoretical work on atomic bandpass filters and spectroscopic characterisations of alkali vapour systems for magneto-optical applications. We demonstrate a new method for generating arbitrary angle
magnetic fields in atomic filters using Rb vapour. This involves a fixed of permanent magnets in a Voigt geometry combined with a solenoid. We compare this method with the previously used method of rotating the permanent magnet
pair. This setup offers more precise and flexible angle control. While both methods generate similar transmission profiles, the new setup allows larger angles and supports longer vapour cells, enhancing magneto-optical filters. Next, we investigate K D1 transition in the presence of neon buffer gas, in particular the pressure induced broadening and frequency shift, and the Zeeman splitting in the hyperfine Paschen-Back (HPB) regime. We use dual-control
temperature systems to independently adjust Doppler and collisional effects, and we achieve excellent agreement with literature values for potassium-neon collisions. For the first time, buffer gas effects integrate into our theoretical model ElecSus, producing accurate prediction of modified Voigt profiles. We conduct a comprehensive experimental and theoretical study into the Stokes polarimetry of potassium atomic vapour with neon buffer gas, focusing on the temperature and magnetic field effects. This work represents the first application of ElecSus to model the buffer gas polarimetry of K D1 transitions.
This study provides new insights into the effects of buffer gases on Stokes parameters, and indicates advances in a theoretical framework for understanding atom-light interactions in buffer gas environments
Nesting Biology of the Leafcutting Bee Megachile minutissima (Hymenoptera: Megachilidae) in Central Saudi Arabia
The leafcutting bee Megachile (Eutricharaea) minutissima Radoszkowski is a widely distributed species in the Middle East and a promising pollinator of alfalfa. We provide information on the nest architecture, foraging behavior, phenology, and host plants of a wild population of M. minutissima studied between March 2010 and September 2012 in Amariah, a typical desert in central Saudi Arabia. Bees nested in preexisting cavities in the sandy, dry, and loose soil, and built between 2 and 14 leaf-lined brood cells per nest. Females built and provisioned 1-2 cells per day, each consisting of a large oval piece from which the cell cup was made and a small semiround piece that was used as cell cap; however, occasionally small oval pieces were also used in the latter. Cells were built from leaves of Ricinus communis L. (Euphorbiaceae), a locally abundant plant. Both sexes were captured from March to October at flowers of 11 species (10 families), indicating some degree of polylecty as well as either bivoltinism or multivoltinism. We also provide comparative taxonomic comments that will assist bee researchers to easily recognize this species
A new species of Chalicodoma from Saudi Arabia with modified facial setae (Hymenoptera, Megachilidae)
Some bees and pollen wasps have independently evolved simple, stiff, erect, apically-curved, curly or hooked facial setae as adaptations to collect pollen from nototribic flowers. A distinctive new species of Chalicodoma Lepeletier de Saint Fargeau subgenus Pseudomegachile Friese from Saudi Arabia with such morphological adaptations, C. riyadhense sp. n., is described and figured. The species was captured visiting flowers of Blepharis ciliaris (L.) (Acanthaceae). The occurrence of modified facial setae is documented and
discussed for the first time in eight other species of Pseudomegachile, and a key to the genera and subgenera of Megachilini currently confirmed for Saudi Arabia is provided
New genera of meliturguline bees from Saudi Arabia and Persia, with notes on related genera and a key to the Arabian fauna (Hymenoptera: Andrenidae)
A new genus of melitturgine bees (Panurginae: Melitturgini) is described and figured from central Saudi Arabia. Belliturgula najdica Engel, gen. et sp. n., is similar in several respects to the genus Flavomeliturgula Patiny in that both have a greatly elongate glossa that is longer than the face and is truncate apically. The former differs in the greatly elongate and flattened first labial palpomere, the remaining palpomeres unmodified, the greatly protuberant clypeus, and long labrum lacking dense setal patches, among other traits. In addition, remarks are made on the composition of Flavomeliturgula, with Meliturgula deserta Warncke (Iran, Pakistan), removed to Khuzimelissa Engel, gen. n., resulting in the new combination Khuzimelissa deserta (Warncke), comb. n. Khuzimelissa differs from Flavomeliturgula by the unmodified labial palpomeres (lacking the elongate first three labial palpomeres of the latter genus), the acute glossa (broadly truncate in the latter), glossa shorter than head length (greater than head length in the latter), the abundant, white, squamiform setae of the mesoscutum (sparse, erect setae in the latter), cleft pretarsal claws (simple in the latter), presence of metasomal setal bands (lacking in the latter), and apically emarginate pygidial plate (acutely rounded in the latter). The species of Flavomeliturgula are organized into three subgenera, including Koreshomelissa Engel, subgen. n., and Freyamelissa Engel, subgen. n., and these may eventually warrant generic status once phylogenetic work on the tribe has been completed. A key to the Arabian genera of Panurginae is provided, along with an augmented key to the genera of subtribe Meliturgulina
Barriers and Facilitators to Children Wearing a Sports Mouthguard: A Systematic Review
A systematic review on the identification of the barriers and facilitators of wearing a sports mouthguard among children. For this, A systematic search was done from different databases following PRISMA guidelines. The six different databases including (Ovid MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily, Embase, Embase Classic, Web of Science, and Scopus) were searched, including the search terms related to the topic. 1470 records were identified, 36 studies were included in this systematic review. The data was collected using a modified data extraction form. The barriers and facilitators found were put into five sociological levels of influence based on the Theoretical Domains Framework domains (individual, interpersonal, organisational, community, and public policy). The Newcastle-Ottawa Scale was used to measure the risk of bias in the included studies. The discovered barriers and facilitators were classified into seven TDF domains, including knowledge, beliefs about consequences, intentions, memory, attention and decision process, environmental context and resources, social influence, and emotions
First record of Chiasmognathus from the Kingdom of Saudi Arabia (Hymenoptera, Apidae)
This is the publisher's version, also available electronically from http://www.pensoft.net/journals/jhr/article/5841/first-record-of-chiasmognathus-from-the-kingdom-of-saudi-arabia-hymenoptera-apidae-The cleptoparasitic bee genus Chiasmognathus Engel (Nomadinae: Ammobatini) is recorded from Saudi Arabia for the first time. Chiasmognathus nearchus Engel was previously known from specimens collected in the United Arab Emirates and Oman. Here we report and figure two individuals captured in central Saudi Arabia
Ecological niche modeling of the rare bee Promelitta alboclypeata reveals possible cryptic differentiation across northern Africa and Arabia (Hymenoptera: Melittidae)
International audienceAbstractThe scarcely collected bee Promelitta alboclypeata with known occurrence across northern Africa and the Arabian Peninsula is a typical example of the bee family Melittidae which encompasses a good number of species with sparse or disjunct distributions and particular flower preferences. Using records for 16 localities, we estimated ecological niche models for P. alboclypeata in Maxent on four sets of occurrences, to represent the disparity of the known records, most of them known from the western section of the range. Our estimates show a predicted area for the species in the northern section of the geographic extent assumed accessible to the species (mainly north Africa and the Arabian Peninsula), signaling feasible regions to survey for the presence of the species; possible ecological niche differentiation between the western and eastern populations is also signaled by the models
New genera of meliturguline bees from Saudi Arabia and Persia, with notes on related genera and a key to the Arabian fauna (Hymenoptera: Andrenidae)
A new genus of melitturgine bees (Panurginae: Melitturgini) is described and figured from central Saudi Arabia. Belliturgula najdica Engel, gen. et sp. n., is similar in several respects to the genus Flavomeliturgula Patiny in that both have a greatly elongate glossa that is longer than the face and is truncate apically. The former differs in the greatly elongate and flattened first labial palpomere, the remaining palpomeres unmodified, the greatly protuberant clypeus, and long labrum lacking dense setal patches, among other traits. In addition, remarks are made on the composition of Flavomeliturgula, with Meliturgula deserta Warncke (Iran, Pakistan), removed to Khuzimelissa Engel, gen. n., resulting in the new combination Khuzimelissa deserta (Warncke), comb. n. Khuzimelissa differs from Flavomeliturgula by the unmodified labial palpomeres (lacking the elongate first three labial palpomeres of the latter genus), the acute glossa (broadly truncate in the latter), glossa shorter than head length (greater than head length in the latter), the abundant, white, squamiform setae of the mesoscutum (sparse, erect setae in the latter), cleft pretarsal claws (simple in the latter), presence of metasomal setal bands (lacking in the latter), and apically emarginate pygidial plate (acutely rounded in the latter). The species of Flavomeliturgula are organized into three subgenera, including Koreshomelissa Engel, subgen. n., and Freyamelissa Engel, subgen. n., and these may eventually warrant generic status once phylogenetic work on the tribe has been completed. A key to the Arabian genera of Panurginae is provided, along with an augmented key to the genera of subtribe Meliturgulina
- …
