The ultimate strength of statically indeterminate prestressed concrete structures

Imperial Users onl

Feedback based real-time MAC (RT-MAC) protocol for data packet streaming in wireless sensor networks

Wireless sensor networks (WSNs) are generally used for event driven monitoring or periodic reporting. Once a triggering event happens, it needs to be reported in real-time as a continuous stream for some duration. In order to address such communication requirements, this thesis introduces a soft Real-Time MAC (RT-MAC) protocol for real-time data packet streaming in wireless sensor networks. RT-MAC eliminates contention for a wireless medium by introducing a feedback control packet, called Clear Channel (CC). As a result, RT-MAC has a consistent and predictable data transmission pattern that provides end-to-end delay guarantees. Additionally, RT-MAC has a lower end-to-end delay than other real-time WSN MAC protocols for two reasons: (1) it maximizes spatial channel reuse by avoiding the false blocking problem caused by request-to-send (RTS) and clear-to-send (CTS) exchanges in wireless MAC protocols (2) it reduces contention duration of control packets to facilitate faster data packet transfer. Thus, RT-MAC facilitates periodic data packet deliveries as well as alarming event reporting. RT-MAC operates both with and without duty cycle mode (sleep/wakeup schedule for sensor nodes). Duty cycle mode of RT-MAC is useful in situations where energy conservation is one of the goals along with real-time requirements. RT-MAC is well suited for multi-hop communication with a large number of hops. RT-MAC protocol supports single-stream communication between a randomly selected source and sink node pair as well as multi-stream communication among different source and sink node pairs. This thesis provides the lower and upper end-to-end delay bounds for data packets transfer in normal mode of operation of RT-MAC protocol. We used state diagram analysis to show the in-depth functioning of RT-MAC protocol. This thesis also presents Markov analysis of RT-MAC that shows the behavior of the protocol in fault scenarios. Extensive simulation results are also presented in this thesis. These results show significant improvement in delay, packet throughput performance, and uniformity in packet transmission pattern at a cost of a very small increase in energy consumption as compared to other real-time MAC protocols such as VTS and general purpose MAC protocols such as S-MAC and T-MAC

The inherent occurrence of complex intron-rich spliceosomal split genes, including regulatory and splicing elements, within pre-biotic random genetic sequences

Growing evidence indicates that complex intron-rich split genes and an advanced spliceosome existed in the earliest eukaryote, and possibly the first life form. We sought to examine how these split genes could have originated in the prebiotic system. We previously found that split coding sequences for complex proteins occur in abundance in random DNA sequences (P. Senapathy, et al, accompanying paper). This study demonstrates that a full complement of exons, introns and regulatory and splicing elements could have also occurred inherently within pre-biotic chemistry by chance. By comparing the characteristics of split genes found in computer-generated random genetic sequences with those of several extant eukaryotes, we show that an abundance of intron-rich split genes akin to those present in modern eukaryotes could have existed in the prebiotic system. These findings answer the post-genomic question of why the earliest life form contained highly complex intron-rich split genes, and, in conjunction with our companion study, show how they could encode a complex spliceosome

Origin of biological information: Inherent occurrence of intron-rich split genes, coding for complex extant proteins, within pre-biotic random genetic sequences

The origin of biological information is an unexplained phenomenon. Prior research in resolving the origin of proteins, based on the assumption that the first genes were contiguous prokaryotic sequences has not succeeded. Rather, it has been established that contiguous protein-coding genes do not exist in practically any amount of random genetic sequences. We found that complex eukaryotic proteins could be inherently encoded in split genes that could exist by chance within mere micrograms to milligrams of random DNA. Using protein amino acid sequence variability, codon degeneracy, and stringent exon-length restriction, we demonstrate that split genes for proteins of extant eukaryotes occur extensively in random genetic sequences. The results provide evidence that an abundance of split genes encoding advanced proteins in a small amount of prebiotic genetic material could have ignited the evolution of the eukaryotic genome

Factors affecting Osseointegration: A Literature Review

The purpose of this literature review is to collect the published data concerning factors affecting osseointegration. Popularity and large demand of dental implant makes this study essential because success of dental implant is directly related to the principle of osseointegration, a process of implant-bone interaction that finally leads to bone-implant anchorage.To identify relevant literature an electronic search was performed using term osseointegration and dental implant on PubMed central. Titles and abstracts were screened andarticles that fulfilled the inclusion criteria were selected for full text reading. Review of selected articles enabled us to enlist various factors which have significant effects on osseointegration either by enhancing or inhibiting it. Based on the review literature, it is concluded that there are factors which when considered may increase osseointegrationwhich in turn will increase success of dental implant and some factors play an inhibiting role for bone-implant contact

Effect of farmyard manure and fertilizer application on crop yield, runoff and soil erosion and soil organic carbon under rainfed pearl millet (Pennisetum glaucum)

A field experiment with four treatments namely control- no application of manure and fertilizer (T1), application of farmyard manure (FYM) at the rate of (@) 5 tonnes/ha/year (T2), application of FYM @ 5 tonnes/ha/year + N:P: K@100: 60: 40 every year (T3) and application of FYM @ 10 tonnes/ha/year + N:P:K @ 100: 60: 40 every year (T4) in pearl millet (Pennisetum glaucum (L.) R. Br. emend. Stuntz) was conducted on sandy loam soils of central Gujarat from 2009 to 2011 under rainfed condition. Plants under T4 were 14 cm, 40.4 cm and 34.2 cm taller than T1 at 30 DAS, 60 DAS and at the time of harvest respectively. Plant height in T3 at the time of harvest was at par with T4. Final biomass under T4 was 25.3, 94.4, and 36.6% higher than T1 during 2009, 2010, and 2011 respectively that gave overall gain of 59.2% in pooled data. Biomass under T4 was 1.2, 5.9 and 11.1% higher as compared to T3 at the time of harvest during 2009, 2010 and 2011 respectively. Effect of application of higher dose of manures in combination with fertilizer (T4) was more prominent in terms of yield as compared to plant height and biomass. Yield under T4 was 153.9, 112.8, and 20.2% higher than T1, T2 and T3 respectively during 2010 whereas it was 70.5, 34.4 and 21.7% higher during 2011. All growth parameters under T2 and T3 were intermediate between T4 and T1. Runoff coefficient was in the range of 22.7 to 30.2% during 2010 and 12.3 to 13.4% during 2011 that was in decreasing order from T1 to T4. As compared to T1, T4 registered 27.7 and 30% per cent low seasonal soil loss in 2010 and 2011 respectively. Application of FYM@ 5 tonnes/ha/year (T2) over the control (T1) had more prominent effect in reducing runoff and soil loss where as application of NPK @ 100:60:40 in addition to FYM@ 5 t/ha (T3) showed no significant effect on runoff and soil loss. Sediment concentration was high in initial few runoff events, highest under T1 and lowest under T4. Strong linear relation (R2 > 0.92) of sediment concentration under T1 with sediment concentration under rest of the treatments was observed. Total soil organic carbon up to depth of 90 cm was 3.43 kg/m2 under T4 that was higher by 0.13 kg/m2 as compared to T1. Improvement in SOC was more prominent in 0-15 cm layer and it was 23.8% higher in T4 as compared to T1. Irrespective of the depth of samples, SOC were high in water stable aggregates (WSA) of size > 0.5 mm. Higher SOC in WSA of 0-15 cm soil as compared to deeper soil were recorded in all the treatments with highest in case of T4. Application of FYM @ 10 tonnes/ha/year + N:P:K @ 100: 60: 40 showed high gain during favourable weather condition in terms of better crop growth parameters, higher yield, lower runoff, lower soil loss and built-up of SOC

Aldehydes: magnificent acyl equivalents for direct acylation

From the viewpoint of meeting the current green chemistry challenges in chemical synthesis, there is a need to disseminate how the cocktail of acylation and activation can play a pivotal role in affording bioactive acylated products comprising substituted ketone motifs in fewer reaction steps, with higher atom-economy and improved selectivity. In recent years, a significant number of articles employing the title compounds “aldehydes” as magnificent acylation surrogates which are less toxic and widely applicable have been published. This review sheds light on the compounds use for selective acylation of arene, heteroarene and alkyl (sp3, sp2 and sp) C–H bonds by proficient utilization of the C–H activation strategy. Critical insights into selective acylation of diverse moieties for the synthesis of bioactive compounds are presented in this review that will enable academic and industrial researchers to understand the mechanistic aspects involved and fruitfully employ these strategies in designing novel molecules

Hedge and Alder-Based Agroforestry Systems: Potential Interventions to Carbon Sequestration and Better Crop Productivity in Indian Sub-Himalayas

Not AvailableAgroforestry systems (AFSs) have potential to combat climate change and to ensure food security. AFSs can sequester carbon and amend the organic matter, thereby enhancing the crop productivity. Carbon sequestration depends on the type of AFSs, climate, cropping pattern, and management practices. The aim of this study was to evaluate different AFSs for their potential to sequester carbon and impact on soil organic matter (SOM) in the eastern sub-Himalayas, India. Hedge-, alder-, and guava-based AFSs were established along with control (without any tree), and the maize–mustard–potato cropping pattern was followed in each AFS. Soil samples were collected after the fifth crop cycle and further analyzed. The results showed that crop productivity was significantly higher in all the AFSs than control. On average, soil organic carbon (SOC) was found to be significantly higher by 62 and 64% in hedge-based AFSs as compared to guava-based AFSs and control, respectively, and at par with alder-based AFSs. Particulate organic carbon (POC) was higher in all the three AFSs than in the control. For microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents, the trend of AFSs was expressed as alder-based AFS > hedge-based AFS > guava-based AFS > control. Hedge- and alder-based AFSs had higher SOC stocks than guava-based AFSs and control. Carbon dioxide equivalent (CO2 eq.) emissions were greater in control than hedge-based AFSs (35.2 Mg ha−1), followed by alder-based AFSs (28.6 Mg ha−1), and the lowest was observed in guava-based AFSs. On an average, hedge species accumulated more nitrogen (N), phosphorus (P), and potassium (K), which were 60, 12, and 28 kg ha−1 yr−1, respectively. This conclusively proved that AFSs were significantly affecting SOM pools and crop productivity and had a significant role in carbon retention in the soil. Overall, hedge- and alder-based AFSs retained higher soil carbon, and hence, hedge- and alder-based AFSs may be promoted to achieve climate-smart agriculture practices in the acid soils of the Indian sub-Himalayan region.Not Availabl

Synthesis of macromolecular systems via lipase catalyzed biocatalytic reactions: applications and future perspectives

Enzymes, being remarkable catalysts, are capable of accepting a wide range of complex molecules as substrates and catalyze a variety of reactions with a high degree of chemo-, stereo- and regioselectivity in most of the reactions. Biocatalysis can be used in both simple and complex chemical transformations without the need for tedious protection and deprotection chemistry that is very common in traditional organic synthesis. This current review highlights the applicability of one class of biocatalysts viz. ‘‘lipases’’ in synthetic transformations, the resolution of pharmaceutically important small molecules including polyphenols, amides, nucleosides and their precursors, the development of macromolecular systems (and their applications as drug/gene carriers), flame retardants, polymeric antioxidants and nanocrystalline solar cells, etc

Design, synthesis and biological evaluation of Arylpiperazine-based novel Phthalimides: active inducers of testicular germ cell apoptosis

Understanding of apoptosis or programmed cell death has provided the basis for novel therapeutics that has resulted in rationally designed anticancer strategies. Recently, inducers of apoptosis have been used in cancer therapy. In this work, we describe the role of chiral phthalimides functionalized with piperazines as potential apoptotic inducers. The listed twenty phthalimides were assessed for their in vitro apoptotic activity against testicular germ cells. All phthalimides showed a significant apoptotic response (∼39 to ∼68%). TUNEL assay and acridine orange fluorescence staining were carried out to investigate the molecular mechanisms responsible for the cell death. Phthalimides exhibited substantial apoptotic induction following the intrinsic pathway mechanism. Studies advocated that the apoptotic induction was mediated through caspase-9, caspase-3, JNK MAP kinase and tumor suppressor p53, which was accompanied by DNA fragmentation and nuclear condensation. Besides, the best five phthalimides regarding apoptotic action were evaluated for in vitro cytotoxic effects against CAL-72 and MCF-7 cancer cell lines. Compounds showed efficient killing of cancer cells. This discovery of functionalized phthalimides as apoptotic inducers would be highly valuable in understanding the mechanism of apoptosis at the molecular level and opens up new possibilities for therapeutic strategies.info:eu-repo/semantics/publishedVersio