594 research outputs found
Floristic analysis and biogeography of Tubiflorae in Egypt
The species distribution and biogeography of the Egyptian Tubiflorae were exam-ined in detail. We found 284 species of vascular plants belonging to 96 genera and 12 families, making the Egyptian Tubiflorae richer in species than that of other arid region floras: Libya and Saudi Arabia. The most species rich families were Scrophulariaceae, Boraginaceae, Labiatae, Convolvulaceae and Solanaceae, constituting more than 85% of the totál species in the order. The generic spectrum dominated by a suite of species-rich genera (Convolvulus, Heliotropium, Veronica, Solanum, Salvia, Cuscuta, Echium, Ipomoea and Orobanche). Therophytes were the most dominant life forms among the families, followed by chamaephytes and hemicryptophytes. Boraginaceae and Scrophulariaceae had the highest share of annuals. Remarkable distribution patterns of the life forms in the seven studied biogeographic zones were noticed. Trees were dominant in the Mediterranean zone, while shrubs, perennial herbs and therophytes were dominant in the Sinai. Altogether 8 endemic species and 14 near-endemics were included in the Tubiflorae of Egypt; mostly from Southern Sinai. We found that Labiatae and Scrophulariaceae were the families with higher concentration of endemics. Notably, Teucrium was among the genera of the Mediterranean Africa with highest endemism. Gamma diversity varied from 171 in the Sinai Peninsula to 43 and 39 in the Oases of the western Desert and along the Red Sea, respectively. Interestingly, highest significant values of similarity and species turnover (béta diversity) were observed between the Oases and the Nile lands. It is worthy noting the com-bined effect of both temperature and precipitation on gamma diversity of Tubiflorae in the 7 biogeographic zones. Our results indicated that almost one-half of the species showed a certain degree of consistency, i.e., with narrow geographic expansion. On the basis of UPGMA clustering and PCoA analysis, 4 floristic groups were recognized, each include one or more biogeographic zone. The occurrence of the species of Tubiflorae in the adjacent régiónál arid floras and their phytochorological afflnities, were discussed
SOLAR HEATING SYSTEM USING PARABOLIC COLLECTOR FOR THERMAL OPTIMUM CONDITIONS OF BIOGAS PRODUCTION IN WINTER
The aim of this study is to enhance the fermentation temperature inside the digester by supplying the required thermal energy to be within the desired optimum range (mesophilic range) for biogas production during winter “cold days”. Two 50 L digesters were used in the experiment that was conducted at Solar Energy Laboratory, Department of Agricultural Engineering, Faculty of Agriculture, Ain Shams University, Cairo. One is a treatment digester and the other is a control digester. The treatment digester is thermally enhanced by a parabolic trough collector, while the control digester operated at the ambient temperature. The experiment was conducted through December 2018 and January 2019. The results show that the average temperature in the control digester through the experiment was 21.5°C, while in the treatment digester it was 27.08°C. This means that the parabolic trough collector enhanced the fermentation temperature in the treatment digester by 20.6%. The total biogas yield of the control digester and the treatment digester was 9684.7 mL/kg. T.S. and 24649.69 mL/kg. T.S. respectively. By comparing both productivities, it was found that the productivity of the treatment digester was 2.5 times more than the productivity of the control digester
A combination of three distinct trafficking signals mediates axonal targeting and presynaptic clustering of GAD65
The signals involved in axonal trafficking and presynaptic clustering are poorly defined. Here we show that targeting of the γ-aminobutyric acid–synthesizing enzyme glutamate decarboxylase 65 (GAD65) to presynaptic clusters is mediated by its palmitoylated 60-aa NH2-terminal domain and that this region can target other soluble proteins and their associated partners to presynaptic termini. A Golgi localization signal in aa 1–23 followed by a membrane anchoring signal upstream of the palmitoylation motif are required for this process and mediate targeting of GAD65 to the cytosolic leaflet of Golgi membranes, an obligatory first step in axonal sorting. Palmitoylation of a third trafficking signal downstream of the membrane anchoring signal is not required for Golgi targeting. However, palmitoylation of cysteines 30 and 45 is critical for post-Golgi trafficking of GAD65 to presynaptic sites and for its relative dendritic exclusion. Reduction of cellular cholesterol levels resulted in the inhibition of presynaptic clustering of palmitoylated GAD65, suggesting that the selective targeting of the protein to presynaptic termini is dependent on sorting to cholesterol-rich membrane microdomains. The palmitoylated NH2-terminal region of GAD65 is the first identified protein region that can target other proteins to presynaptic clusters
Compact Circularly Polarized Multiband Antennas for RFID Applications
This paper presents multiband circularly polarized (CP) antennas for
radio frequency identification (RFID). A coax-fed and a microstrip-line-fed antennas having optimized cross-slots in their patches are first
designed for dual-band CP operation. The microstrip-line-fed design is then modified, by incorporating a U-shaped slot in its partial ground
plane, to achieve additional operation band with a CP characteristic. Simulation and measured results of the presented designs are reported.
The measured results are in accordance with the computed ones. The compact size and CP property make these designs suitable for RFID
applications
Systematic review of brucellosis in the Middle East: disease frequency in ruminants and humans and risk factors for human infection
Posterior fossa meningiomas: Correlation between site of origin and pathology
Aim: to identify the possible correlation between demographic data of the patients, site of tumor origin, and pathological characteristics of each subgroup of the posterior fossa meningiomas as the anatomical location of these tumors is a critical determinant of the operative approach that will be chosen.Materials and Methods: We analyzed medical records of 35 patients with posterior fossa meningiomas who underwent surgery between January 2005 and December 2009 at Neurosurgery Department, Ia?i. The analysis included: age and gender of the patients, tumor location, and pathologic findings. According to the anatomical relationship with posterior fossa structures, these 35 meningiomas were classified into 5 types: cerebellar convexity, cerebellopontine angle, petroclival, foramen magnum, and unclassified tumors. According to the classification scheme of WHO 2007 (19), all cases were classified into three histopathological groups: benign, atypical, and malignant meningiomas, and every histopathological subtype was noted.Results: Posterior fossa meningiomas have a 3.33:1 female-to-male ratio with a mean age of 51.6 years. 29 patients had anatomically distinct attachment to the dura of the 4 chosen compartments of the posterior fossa (cerebellar convexity – 14.28%, cerebellopontine angle – 48.57%, petroclival – 11.42%, and foramen magnum – 8.57%) and 6 patients (17.14%) had giant tumors with broad attachment in multiple areas of the posterior fossa. Grade I meningiomas encountered in majority of cases (82.85%), whereas grade II meningiomas were diagnosed in 11.42% of the operated case, and anaplastic meningiomas (grade III) accounted only 5.71%. The most common benign histological subtypes among posterior fossa meningiomas were fibrous (37.79%) and psamomatous (24.13%). Petroclival meningiomas accounted a higher incidence then that presented in other studies (11.42% of all posterior fossa meningiomas). The mean age for female patients was older (55 years) then in other studies. There were various benign histological subtypes (psammomatous, meningothelial, and secretory) and even an atypical one that was diagnosed in a male patient. Foramen magnum meningiomas affected only females with a mean age of 52.66 years. All tumors were benign (grade I) with psammomatous subtype being the most common histological subtype (66.66%). Cerebellar convexity meningiomas presented a female to male ratios of 4:1. Female patients were older (64.25 years) then the mean age of patients with posterior fossa meningiomas. In cerebellar convexity location, all meningiomas presented only benign histology (fibrous subtype, 100%) that made us thinking to a different tumorigenesis for this tumors comparative with other locations. Cerebellopontine angle meningiomas presented a strong preponderance of female patients (5:1). Though majority of cerebellopontine angle meningiomas had grade I of malignancy, they exhibited a large variety of histological subtypes.Conclusion: In our series, posterior fossa meningiomas are clearly various tumors in their histology and demographic data. We identified a significant association between age and gender of the patients, histology of posterior fossa meningiomas, and their site of origin
Loss of heterozygosity of TRIM3 in malignant gliomas
<p>Abstract</p> <p>Background</p> <p>Malignant gliomas are frequent primary brain tumors associated with poor prognosis and very limited response to conventional chemo- and radio-therapies. Besides sharing common growth features with other types of solid tumors, gliomas are highly invasive into adjacent brain tissue, which renders them particularly aggressive and their surgical resection inefficient. Therefore, insights into glioma formation are of fundamental interest in order to provide novel molecular targets for diagnostic purposes and potential anti-cancer drugs. Human <it>Tripartite motif protein 3 </it>(<it>TRIM3</it>) encodes a structural homolog of <it>Drosophila brain tumor </it>(<it>brat</it>) implicated in progenitor cell proliferation control and cancer stem cell suppression. <it>TRIM3 </it>is located within the loss of allelic heterozygosity (LOH) hotspot of chromosome segment 11p15.5, indicating a potential role in tumor suppression. ...</p> <p>Methods</p> <p>Here we analyze 70 primary human gliomas of all types and grades and report somatic deletion mapping as well as single nucleotide polymorphism analysis together with quantitative real-time PCR of chromosome segment 11p15.5.</p> <p>Results</p> <p>Our analysis identifies LOH in 17 cases (24%) of primary human glioma which defines a common 130 kb-wide interval within the <it>TRIM3 </it>locus as a minimal area of loss. We further detect altered genomic dosage of <it>TRIM3 </it>in two glioma cases with LOH at 11p15.5, indicating homozygous deletions of <it>TRIM3</it>.</p> <p>Conclusion</p> <p>Loss of heterozygosity of chromosome segment 11p15.5 in malignant gliomas suggests <it>TRIM3 </it>as a candidate brain tumor suppressor gene.</p
Rapid Redistribution of Synaptic PSD-95 in the Neocortex In Vivo
Most excitatory synapses terminate on dendritic spines. Spines vary in size, and their volumes are proportional to the area of the postsynaptic density (PSD) and synaptic strength. PSD-95 is an abundant multi-domain postsynaptic scaffolding protein that clusters glutamate receptors and organizes the associated signaling complexes. PSD-95 is thought to determine the size and strength of synapses. Although spines and their synapses can persist for months in vivo, PSD-95 and other PSD proteins have shorter half-lives in vitro, on the order of hours. To probe the mechanisms underlying synapse stability, we measured the dynamics of synaptic PSD-95 clusters in vivo. Using two-photon microscopy, we imaged PSD-95 tagged with GFP in layer 2/3 dendrites in the developing (postnatal day 10–21) barrel cortex. A subset of PSD-95 clusters was stable for days. Using two-photon photoactivation of PSD-95 tagged with photoactivatable GFP (paGFP), we measured the time over which PSD-95 molecules were retained in individual spines. Synaptic PSD-95 turned over rapidly (median retention times τ (r) ~ 22–63 min from P10–P21) and exchanged with PSD-95 in neighboring spines by diffusion. PSDs therefore share a dynamic pool of PSD-95. Large PSDs in large spines captured more diffusing PSD-95 and also retained PSD-95 longer than small PSDs. Changes in the sizes of individual PSDs over days were associated with concomitant changes in PSD-95 retention times. Furthermore, retention times increased with developmental age (τ (r) ~ 100 min at postnatal day 70) and decreased dramatically following sensory deprivation. Our data suggest that individual PSDs compete for PSD-95 and that the kinetic interactions between PSD molecules and PSDs are tuned to regulate PSD size
Dual role of the exocyst in AMPA receptor targeting and insertion into the postsynaptic membrane
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102104/1/emboj7601065.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102104/2/emboj7601065-sup-0001.pd
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