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Genetic Characterization of Quorum Sensing Dependent Bacterial Isolates Associated With Legumes

Thesis Info

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Author

Khan, Sami Ullah

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2014

Thesis Completion Status

Completed

Subject

Botany

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/904

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726286035

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The present study aimed at characterizing two Acyl Homoserine Lactone (AHLs) producing bacteria isolates nodulating (cultivated and wild) legumes. The isolate from cultivated Pisum sativum was named as Pcc1; while that isolated from the wild species Alysicarpus buleurifolius was called Pcc21. These isolates were selected from a set of twenty potential isolates obtained from the culture collection of Department of Plant Sciences, Quaid-i-Azam University. The initial screening of isolates was done for AHLs production using Chromobacterium violaceum (CV026) as indicator strain. These AHLs were further characterized for their diversity through TLC and LC/MS analyses. The TLC assay was done to study the size and range of the AHLs, revealing diverse nature of AHLs produced by the Pcc1 and Pcc21. The small bacteriocin assay revealed that Pcc1 produced AHLs which are a characteristic of CinI system, however, the Pcc21 was found negative. The phylogenetic analyses based on 16S rRNA sequences depicted the isolate Pcc1 as Rhizobium leguminosarum while that of Pcc21 as Sinorhizobium meliloti. Pcc1 being Rhizobium was further studied for the RhiR system which controls nodulation in host plants. Thus the RhiR gene was amplified and sequenced and using bioinformatics tools its protein sequences was generated. The sequence data thus generated and its comparison with the RhiR protein sequences in silico revealed useful information for the isolate (Pcc1) under study such as various domains homolgous to the LuxR transcriptional protein. To characterize it further mutation of RhiR locus was done using Pk19 mob vector, the induced mutation reduced the AHLs production and nodulation efficiency. The Pcc21 presented an interesting case. The 16S rRNA analysis revealed its identity as Sinorhizobium meliloti and it was isolated from root nodules of a wild legume species Alysicarpus bupleurifolius, this has been the first report on the novel symbiotic association between S. meliloti and Alysicarpus bupleurifolius. The study further characterized the AHL diversity produced in symbiosis. The TLC and LC-MS profiles revealed production of a diverse array of AHLs that ranged from short chain C4-HSL to long chain C12- HSL. It was observed that isolates thriving in younger nodules produced AHL abundance and points to the possible presence of more than one synthase system, as previously described in Rm1021 and AK63. The isolation of a strain producing wide ranging AHL molecules provides an opportunity to investigate the complex genetics of AHL production in S. melitoti. It was further revealed that the AHLs produced by Pcc21 were rather diverse. In an analysis the introduction of WspR plasmid in Pcc21 decreased the amount of exopolisaccharides produced in the system, however it did not affect the overall amount of AHLs produced.
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سیدسجاد حیدر یلدرم

سید سجاد حیدریلدرم مرحوم
۱۲؍ اپریل ۱۹۴۳؁ء کی رات کو سید سجاد حیدر مرحوم نے جو ادب کی دنیا میں یلدرم کے نام سے مشہور تھے، قلب کے عارضہ سے دفعتہ وفات پائی، یہ علی گڑھ کالج کے پرانے تعلیم یافتوں میں اور اسی تعلق سے کالج کے ان چند طالب علموں میں تھے جنہوں نے مولانا شبلی مرحوم کے درس اور صحبت سے شعر و ادب کا ذوق حاصل کیا تھا، مرحوم مولانا کے درس کے اس قسم کے واقعات کو مزے لے لے کر بیان کیا کرتے تھے، ان کا اصل وطن نہٹور (یوپی) میں تھا، ۱۹۰۱؁ء میں بی، اے کی سند پاکر تعلیم سے فراغت پائی۔
ہماری زبان میں اس وقت ادب لطیف کا جو رواج ہے، اس کے پرانے لکھنے والوں میں سب سے پہلا نام سید حیدر مرحوم کا ہے اور چونکہ قادر مطلق کو ان سے یہ کام لینا تھا، اس لئے ان کی زندگی میں اس کا مناسب سامان بھی پیدا کردیا یعنی یہ کہ کالج کے زمانہ ہی میں ان کو ترکی پڑھنے کا خیال ہوا، علی گڑھ میں نواب محمد اسمٰعیل خان صاحب رئیس علی گڑھ کے والد بزرگوار ہجرت کرکے مکہ معظمہ چلے گئے تھے، وہیں نواب محمد اسمٰعیل خاں صاحب کی تعلیم و تربیت ہوئی، اس زمانہ میں ترکی وہاں کی سرکاری زبان تھی، اس لئے ان کو ترکی بھی پڑھائی گئی اور جب وہ ہندوستان آئے تو وہ ترکی ادب کے گویا نمائندہ ہوکر آئے، چنانچہ سرسید کے ’’تماشائے عبرت‘‘ میں وہ اسی ہیئت سے اسٹیج پر آئے ہیں اور معارف علی گڑھ میں جس کے وہ شریک ایڈیٹر تھے، وہی ترکی ادب کی اشاعت کا ذریعہ بنے۔
بہرحال سجاد حیدر مرحوم نے انہی سے ترکی زبان سیکھی اور اس کا یہ فائدہ ان کو پہنچا کہ سرکار انگریزی نے ان کو علی گڑھ...

Citizens' Assessment on Programs for Education of the Local Government Unit of Banga, Aklan

Citizen Satisfaction Index System (CSIS) was used to assess the delivery of support to education initiatives in the municipality of Banga, Aklan, Philippines. The samples were determined using multiple application of stratified random sampling approach. In accordance with the Philippine Statistical Authority's Data on Census Population and Housing for 2015, barangays having a bigger share of the population contributed more respondents to the 150 targeted participants. Following the inclusion criteria, the probability respondents were chosen using the Kish Grid. Pre-numbered questionnaires were distributed, with odd numbers targeting male responders and even numbers targeting females. The following criteria were used to evaluate the respondents' assessments: awareness, availment of the program/service, satisfaction, and need for action. Furthermore, interviews were conducted to better understand and investigate the respondents' thoughts, behavior, and perspectives. The reasons for their reaction were also obtained. The data was provided in percentage as well as frequency distributions. The study inferred that awareness on alternative learning system and/or special education program should be improved since it is the only program that attained low rating for awareness. Most of the residents were not able to avail education programs because they have no household member who attends school. Majority of the respondents who availed the services were satisfied. However, scholarship and other assistance programs to students may be enhanced to improve service delivery. It is highly recommended by the citizens to improve accessibility to scholarship programs and other forms of financial assistance to students.

Synthesis and Characterization of Nanoparticles Added Cutl-Based Superconductors

Low anisotropic (Cu 0.5 Tl 0.5 )Ba 2 Ca 2 Cu 3 O 10-δ (CuTl-1223) phase of Cu 1-x Tl x Ba 2 Ca 2 Cu 3 O 10- δ [CuTl-12(n-1)n]; n=1, 2, 3, ... high temperature superconducting (HTSC) family was synthesized by solid-state reaction method. Nanoparticles (NPs) were prepared separately by different techniques (i.e. co-precipitation, sol-gel, and colloidal solution methods). Different kinds and sizes of NPs such as non-magnetic metallic (Ag, Au), non-magnetic metallic oxide (Al 2 O 3 ) and magnetic ferrite (CoFe 2 O 4 ) were added with different wt.% during the final sintering process of CuTl-1223 superconducting matrix to get the required (NPs) x /CuTl-1223 nanoparticles-superconducting composites. These composites were characterized by different experimental techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray (EDX) spectroscopy, resistivity versus temperature measurements, critical current density (J c ) measurements, magnetic ac-susceptibility measurements, Fourier transform infrared (FTIR) spectroscopy etc. The experimental data were analyzed by different well established theoretical models such as Aslamazov-Larkin (AL), Lawerence-Doniach (LD) and Maki-Thompson (MT) models. It was observed that tetragonal structure and stoichiometry of the host CuTl-1223 superconducting phase remained unaltered after the addition of these NPs, which indicates about the occupancy of these NPs at the inter-granular spaces. Non-magnetic metallic NPs (Ag, Au) have improved the superconducting transport properties (T c , J c , etc) up to certain optimum concentration of these NPs in CuTl-1223 matrix. The improvement in the superconducting properties can be attributed to an increase in the inter-grains connectivity by healing up the inter-grains voids and pores after the addition of these NPs. The improved inter-grains connections can facilitate the carriers transport processes across the inter-crystallite sites due to their metallic nature. But the superconducting volume fraction starts to be decreased after certain optimum inclusion level of these non-magnetic non-superconducting metallic NPs, which causes the suppression of superconductivity parameters. The effects of highly coercive cobalt ferrite (CoFe 2 O 4 ) nanoparticles addition on superconducting properties of CuTl-1223 matrix were also explored. The magnetic behavior of CoFe 2 O 4 nanoparticles was determined by MH-loops with the help of superconducting quantum interference device (SQUID). The resistivity versus temperature measurements showed an increase in T c (0), which could be most probably due to improvement of weak-links by the addition of these nanoparticles. The increase of mass density with xxviincreasing content of these NPs can also be an evidence of filling up the voids in the matrix. But the addition of these NPs beyond an optimum level caused the agglomeration and produced additional stresses in material and suppressed the superconductivity. We observed non- monotonic variation of superconducting properties after the inclusion of nano-Al 2 O 3 particles, which can be associated with inhomogeneous distribution of these NPs at the grain-boundaries in CuTl-1223 matrix. But overall suppression of superconducting properties was attributed to a pair-breaking mechanism caused by reflection/scattering of carriers across these insulating nano- Al 2 O 3 particles present at the grain-boundaries of the host CuTl-1223 matrix. The presence of Al 2 O 3 nanoparticles at the grain-boundaries possibly reduced the number of flux pinning centers, which were present in the form of weak-links in pure CuTl-1223 superconducting matrix. The suppression of activation energy {U (eV)} may be due to weak flux pinning in the nano-Al 2 O 3 particles added samples. The superconducting microscopic parameters (i.e. zero temperature coherence length along c-axis {xc (0)}, inter-layer coupling (J), inter-grain coupling (a) etc.) deduced from fluctuation induced conductivity (FIC) analysis with the help of above mentioned theoretical models explained the experimental findings very well. For example, the increase in the values of inter-grain coupling (a) deduced from FIC analysis is a theoretical evidence of improved inter-grain coupling in the host CuTl-1223 matrix with the increased contents of these nanoparticles. We also calculated the activation energy {U (eV)} of (NPs) x /CuTl-1223 nanoparticles-superconducting composites. The increase in T c (0), J c , U (eV) etc and decrease in normal state resistivity {ρ 300 K (Ω-cm)} were observed after the addition Ag, Au and CoFe 2 O 4 NPs in CuTl-1223 superconducting phase. The suppression of superconducting properties (i.e. T c (0), J c , U (eV) etc) after the addition of Al 2 O 3 nanoparticles in host CuTl-1233 superconducting matrix was observed.