451 research outputs found
IPLFS: Log-Structured File System without Garbage Collection
No full textIn this work, we develop the log-structured filesystem that is free from garbage collection. There are two key technical ingredients: IPLFS, a log-structured filesystem for infinite partition, and Interval Mapping, a spaceefficient LBA-to-PBA mapping for infinite filesystem partition. In IPLFS, we separate the filesystem partition size from the physical storage size and set the size of the logical partition large enough so that there is no lack of free segments in the logical partition during SSD's lifespan. This allows the filesystem to write the updates in append-only fashion without reclaiming the invalid filesystem blocks. We revise the metadata structure of the baseline filesystem, F2FS, so that it can efficiently handle the storage partition with 264 sectors. We develop Interval Mapping to minimize the memory requirement for the LBA-to-PBA translation in FTL. Interval Mapping is a three level mapping tree. It maintains mapping only for actively used filesystem region. With Interval Mapping, the FTL can maintain the mapping for the 264 sector range with almost identical memory requirement with the page mapping whose LBA range is limited by the size of the storage capacity. We implement the IPLFS on Linux kernel 5.11.0 and prototype the Interval Mapping in OpenSSD. By eliminating the filesystem level garbage collection, IPLFS outperforms F2FS by up to 12.8× (FIO) and 3.73× (MySQL YCSB A), respectively
Tracking depositional and geochemical variations in the Cambrian North China Platform: Insights from sedimentology, geochemistry, and C-O isotopic records
No full textاُردو زبان و ادب کے فروغ میں مشاہیرِ قصور کی خدمات کا جائزہ
No full textThe three rivers Sutlej, Ravi and Beas are flowing in the district of Kasur in Pakistani Punjab. Now this city is situated on the two banks of the dried river Bias. Its history is as old as that of Lahore. The father of Urdu poetry Ameer Khusro has also mentioned this city in his book " Quran es Saadeen”. The importance and worth of this city can be estimated from the fact that the legendary Sufi poets like Bhulleh Shah and Waris Shah also came there to acquire knowledge. In each period, this land produced literary legends whose role was not appreciated in Kasur, rather the echoes of their fame were also heard in the annals of history at national and international level. In literary genres, Sir Abdul Qadir, Dr. Muhammad Iqbal, Dr. Muhammad Shafee, Dr. Daud Rehbar, Dr Tehseen Firaaqi, Rasheeda Saleem Seemee, Irshad Ahmad Haqqani, Hajji Luq Luq, Maqsood Hassni, Muhammad Ali Zahoori, Muhammad Sadiq Qasoori, Muhammad Iqbal Najmi etc have played an important role in novel, drama, fiction, autobiography, correspondence, research, criticism, travelogue, translation, ode, poem, Naat etc_ for promoting Urdu language and literature. There is unprecedented and they are the central figures of Urdu literature. Their works reflect the culture, civilization, and society of this land in a true sense
Evaluating the status of vitamin 25(OH) D levels among females of all age groups in Karachi, Pakistan.
No full textIntroduction: Vitamin D plays an important role in growth, metabolism and reproduction. Deficiency of this vitamin is highly prevalent globally and leads to various disorders besides different skeletal deformities. Women of different reproductive ages are at higher risk of developing bone diseases because of low vitamin D levels.
Objective: This study aimed to assess the prevalence of vitamin D deficiencies in females of different ages in Karachi, Pakistan
Methodology: A retrospective investigation of vitamin D levels during a six month period at the Clinical Lab, Al-Khidmat Diagnostic Center, Karachi; Pakistan was performed. Serum vitamin 25(OH) D levels of 1035 female were measured by Electrochemiluminescence (ECL) assay. The data was analyzed through SPSS version 16.
Results: Among 1035 participants of different reproductive ages, 26.1% (n= 270) showed severe vitamin D deficiency, 44.3% (n=458) displayed mild to moderate Vitamin D deficiency while 29.7% (n=307) were having normal levels of serum vitamin D.
Results: The data of 1035 subjects was examined and the mean serum vitamin 25(OH) D levels of the studied subjects were found as 21.04±14.13 with the minimum and maximum range of 4.97ng/ml to 70.71ng/ml
Conclusion: 70.4 % of our studied population had lower levels of vitamin D representing that the majority of Pakistani womenfolk have vitamin D Deficiency.
Keywords: Vitamin 25 (OH) D levels, Female population, Karachi.
 
Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.
No full textThe deep-sea brines of the Red Sea are remote and unexplored environments characterized by high temperatures, anoxic water, and elevated concentrations of salt and heavy metals. This environment provides a rare system to study the interplay between halophilic and thermophilic adaptation in biologic macromolecules. The present article reports the first DNA polymerase with halophilic and thermophilic features. Biochemical and structural analysis by Raman and circular dichroism spectroscopy showed that the charge distribution on the protein's surface mediates the structural balance between stability for thermal adaptation and flexibility for counteracting the salt-induced rigid and nonfunctional hydrophobic packing. Salt bridge interactions via increased negative and positive charges contribute to structural stability. Salt tolerance, conversely, is mediated by a dynamic structure that becomes more fixed and functional with increasing salt concentration. We propose that repulsive forces among excess negative charges, in addition to a high percentage of negatively charged random coils, mediate this structural dynamism. This knowledge enabled us to engineer a halophilic version of Thermococcus kodakarensis DNA polymerase.-Takahashi, M., Takahashi, E., Joudeh, L. I., Marini, M., Das, G., Elshenawy, M. M., Akal, A., Sakashita, K., Alam, I., Tehseen, M., Sobhy, M. A., Stingl, U., Merzaban, J. S., Di Fabrizio, E., Hamdan, S. M. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea
Karen Armstrong's Perspective on the Prophet's Biography. A Review in the Light of Islamic Teachings: کیرن آرمسٹرانگ کا سیرت رسولﷺ پر نقطہ نظر اسلامی تعلیمات کی روشنی میں جائزہ
No full textKaren Armstrong, a renowned scholar of comparative religion, offers a unique and insightful perspective on the biography of the Prophet Muhammad in her various works. This review critically examines Armstrong's portrayal of the Prophet's life, assessing it through the lens of Islamic teachings. Armstrong emphasizes the Prophet's role as a social reformer, a proponent of justice, and a spiritual leader, depicting him as a figure of compassion and wisdom. She contextualizes his life within the socio-political environment of 7th-century Arabia, highlighting his efforts to address tribal conflicts and social inequalities. Armstrong’s approach is notable for its empathetic understanding and attempt to bridge cultural gaps between the West and the Islamic world. She challenges stereotypical representations and offers a nuanced narrative that seeks to humanize the Prophet Muhammad, presenting him as a complex and multifaceted individual. However, this review juxtaposes her interpretations with traditional Islamic sources such as the Quran, Hadith, and classical biographies (Sira) to identify areas of convergence and divergence. Key Islamic teachings underscore the Prophet's mission as one guided by divine revelation, emphasizing his role as the final messenger of God. This perspective sometimes contrasts with Armstrong's more secular and historical analysis. For instance, while Armstrong acknowledges the spiritual dimensions of the Prophet's life, her primary focus on his socio-political achievements might underplay the profound religious significance attributed to him by Muslims. Furthermore, this review explores how Armstrong's interpretations align with or diverge from key Islamic concepts such as prophethood, revelation, and the moral and ethical framework established by the Prophet. By comparing Armstrong’s work with Islamic teachings, this review aims to provide a balanced and comprehensive understanding of the Prophet Muhammad's biography, highlighting the contributions of both Western scholarship and Islamic tradition
Zinc homeostasis in plants : identification and characterisation of new mechanisms
No full textTypescriptDepartment of GeneticsThesis (PhD) -- University of Melbourne, Faculty of Science, 2009Includes bibliographical references (pages 147-161)Zinc (Zn) is an essential element in numerous biochemical and physiological processes in plants, yet at elevated concentrations Zn can be toxic. Plants have a number of membrane Zn transporters of the ZIP, CDF and P-type ATPase classes. The P1B ATPases, HMA2 and HMA4, in Arabidopsis are essential for Zn homeostasis: an hma2; hma4 double mutant is severely Zn-deficient and can be rescued by the application of exogenous Zn (Hussain et al, 2004). This study aims to identify additional components of Zn homeostasis. First, an activation tag T-DNA (Weigel et al., 2000) was used to suppress to hma Zn-deficient phenotype. More than 14,000 transformants were isolated and found three hma2, hma4 double mutant plants showing suppression of the phenotype without Zn supplementation in the soil. Unfortunately, probably due to cross-pollination from other transgenic plants, these turned out to be contaminants containing a different transgene expressing HMA2.
A complete inventory of metallochaperone-like proteins containing an HMA domain in Arabidopsis revealed a surprisingly large family of proteins (67). In this family cluster IV is notable because of the presence of conserved Asp (D) residue before the CxxC, metal binding motif, analogous to the Zn binding motif in the E. coli ZntA. Some members of this cluster were studied in more detail. HIPP20, HIPP21, HIPP22, HIPP26 and HIPP27 were able to rescue the Cd-sensitive, ycf1 yeast mutant but failed to rescue the growth of zrt1zrt2, zrc1cot1 and ?atx1 mutants. Characterisation of hipp20/21/22, triple mutant suggests the HIPPs can have a role in Cd-detoxification, probably by binding Cd. The triple mutant was more sensitive to Cd and accumulated less Cd compared to the wild-type. Also, hipp21/26 double mutant exhibited a late-bolting phenotype. Promoter-GUS reporter expression studies indicate variable expression of HIPPs in different tissues. In roots where HIPP26 is only expressed in lateral root tips, HIPP20, HIPP21, HIPP22 and HIPP25 showed strong expression in the root vasculature. Yeast two-hybrid studies indicate that none of the HIPPs tested was able to interact with the N-terminal metal binding domain of HMA2 and HMA4 and a yeast two-hybrid library screen identified a zinc finger protein, At3g62970 that strongly interacts with N-terminal domain of HMA4 but not of HMA2. This protein may have role in HMA4 turn-over via the ubiquitination pathway
Symmetric bound states of Josephson vortices in BEC
No full text A system of two parallel coupled cigar-shaped Bose–Einstein condensates is considered in an effectively one-dimensional limit. The dynamics of the system is characterized by a pair of coupled nonlinear Gross–Pitaevskii equations. In particular, the existence and stability of symmetric bound states of Josephson vortices are investigated. It is realized that the symmetric bound state Josephson vortices solution persists stably in its whole domain of existence for the coupling strength. Nevertheless, the bound states solution converts into a dark soliton at a critical value of coupling parameter. </jats:p
Genome-wide association study of resistance to PstS2 and Warrior races of Puccinia striiformis f. sp. tritici (stripe rust) in bread wheat landraces
No full textStripe or yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici is a
major threat to bread wheat production worldwide. The breakdown in resistance
of certain major genes and newly emerging aggressive races of stripe rusts
pose serious concerns in all main wheat growing areas of the world. To identify
new sources of resistance and associated QTL for effective utilization in
future breeding programs an association mapping (AM) panel comprising of
600 bread wheat landraces collected from eight different countries conserved
at ICARDA gene bank were evaluated for seedling and adult plant resistance
against the PstS2 and Warrior races of stripe rust at the Regional Cereal Rust
Research Center (RCRRC), Izmir, Turkey during 2016, 2018 and 2019. A set of
25,169 informative SNP markers covering the whole genome were used to examine
the population structure, linkage disequilibrium and marker-trait associations
in the AM panel. The genome-wide association study (GWAS) was carried
out using a Mixed LinearModel (MLM).We identified 47 SNP markers across 19
chromosomes with significant SNP-trait associations for both seedling stage and adult plant resistance. The threshold of significance for all SNP-trait associations
was determined by the false discovery rate (q)≤0.05. Three genomic regions
(QYr.1D_APR, QYr.3A_seedling and QYr.7D_seedling) identified in this study do
not correspond to previously reported Yr genes or QTL, suggesting new genomic
regions for stripe rust resistance
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