Lab-on-a-chip surface plasmon resonance biosensor for multiplex bioassays

This thesis titled “Lab-on-a-Chip Surface Plasmon Resonance Biosensor for\ud Multiplex Bioassays” describes new developments in the integration of an SPR\ud imaging based biosensor and electrokinetic lab-on-a-chip. This research was aimed to\ud develop a strategy to multiplex a bioassays in combination with high-throughput,\ud which not only saves a huge amount of time, but also reduces the cost of such assays\ud while performing multiple assays simultaneously. The major advantage of using\ud electrokinetic driven fluidics instead of conventional pressure driven flow is to avoid\ud complex plumbing network, valves and pumps, especially when large number of\ud microchannels (n > 10) are used. This thesis describes a successful operation of a\ud newly developed integrated biosensor system which needs a single voltage supply only.\ud This thesis also explores the possibilities of measuring (multiple) biomolecular\ud interaction kinetics in a different way compared to the conventional approaches, taking\ud the advantage of the microarray integrated SPR imaging system

Storage and hydrolysis of seawater samples for inorganic carbon isotope analysis

Preservation of seawater samples was tested for total inorganic carbon (ΣCO2), stable carbon isotope (δ13C), and radiocarbon (14C) applications using foil bags and storage by refrigeration and freezing. The aim was to preserve representative samples with minimal storage effects but without using toxic methods such as mercuric chloride poisoning. Hydrolysis of samples to CO2 was based on existing methods. Results of IAEA-C2 standard used with deionized water stored in the foil bags showed complete reaction yields, 14C results within 2σ of the consensus value, and δ13C that were internally consistent, indicating that there were no procedural effects associated with the foil bags. 14C results were statistically indistinguishable across the storage times, for frozen and refrigerated seawater samples from a coastal site, Elie Ness, Fife, UK. The scatter of ΣCO2 concentrations and δ13C was within scatter observed in other studies for lake- and seawater samples preserved by acidification or using mercuric chloride. However, both ΣCO2 and δ13C were less variable for frozen samples compared with refrigerated samples. The foil bags are lighter, safer to transport, and similar in cost to glass bottles and allow sample collection in the field and transfer to the hydrolysis vessel without exposure of the sample to atmosphere. Storage of seawater samples in the foil bags was considered a reliable, alternative method to poisoning for ΣCO2, δ13C, and 14C, and freezing the samples is recommended for storage time beyond a week

Evidence for anthropogenic ¹⁴C-enrichment in estuarine waters adjacent to the North Sea

[1] The isotopic composition (d13C and D14C) of high molecular weight dissolved organic carbon (HMW DOC) was studied in the Tyne and Tweed estuaries, NE England. Despite significant removal of terrigenous HMW DOC in the low salinity regions (S < 15), D14C remained modern with little variation around 115%. This lack of apparent age discrimination was attributed to either non-oxidative removal or the absence of a significant proportion of old refractory C in the HMW DOC pool. At S < 15, we observed seaward increases in d13C and D14C. With no documented local 14C inputs, we attributed non-bomb related 14C-enrichment at S < 15 to a possible ‘lingering effect’ of distal anthropogenic sources in near-coastal North Sea HMW DOC. Given the global distribution of potential sources, we propose that anthropogenic 14C should be considered in assigning ages of DOC pools in near-coastal waters and suggest its possible use as a tracer for DOC transformations

Deglacial Si remobilisation from the deep-ocean reveals biogeochemical and physical controls on glacial atmospheric CO2 levels

During the last glacial period, the sluggish deep Ocean circulation sequestered carbon into the abyss leading to the lowering of atmospheric CO2. The impact of this redistribution on biologically essential nutrients remains poorly constrained. Using sedimentary δ30 Si of diatoms and biogenic accumulation rates in the Eastern Equatorial Pacific (EEP), we present evidences for the remobilisation of dissolved Silica (DSi) along with carbon from the deep ocean during the Last Deglaciation. Because DSi is essential for diatoms growing in the surface ocean, its concentration in the abyss during the glacial periods amounts to a negative feedback on the oceanic CO2 uptake. However, this effect can be muted by the increased Fe inputs during glacial periods which reduces diatom Si requirements in Fe limited regions such as the EEP. Our results from the EEP suggest that the efficiency of the biological CO2 pump and the size of the local CO2 source is tightly controlled by changes in DSi utilisation driven by Fe availability across the last glacial-interglacial transition.We use a modified PANDORA box model to illustrate that the inventory of DSi in the global ocean surface is controlled by Fe availability in HNLC areas rather than by straightforward Si supply though upwelling. The Holocene is characterised by a fast mode of Si cycling driven by high biological requirement for Si under conditions of iron limitation and efficient overturning, promoting CO2 outgassing and an inefficient biological C pump via the rapid exhaustion of DSi in the surface. The last glacial period saw slower marine Si cycling as a result of decreased DSi biological requirement under Fe-replete conditions in the sea surface and increased Si and CO2 sequestration in the abyssal ocean. The switch between the two modes of Si cycling happened at 15 ka BP, i.e. mid-deglaciation, and resulted in contrasting biological carbon drawdown responses in the EEP and globally between both phases of the deglacial CO2 rise. This illustrates that in addition to deep-sea CO2 storage and overturning, the efficiency of the biological pump also plays a crucial role in determining ocean-atmosphere CO2 exchange and shows the dual controls of ocean circulation and Fe-Si availability in this process.</p

Growth reduction of similarity transformed electronic Hamiltonians in qubit space

Accurately solving the electronic structure problem through the variational quantum eigensolver (VQE) is hindered by the available quantum resources of current and near-term devices. One approach to relieving the circuit depth requirements for VQE is to "pre-process" the electronic Hamiltonian by a similarity transformation incorporating some degree of electronic correlation, with the remaining correlation left to be addressed by the circuit ansatz. This often comes at the price of a substantial increase in the number of terms to measure in the unitarily transformed Hamiltonian. In this work, we propose an efficient approach to sampling elements from the unrestricted pool of N-qubit Pauli products which minimize the onset of new terms in the transformed Hamiltonian, while facilitating substantial energy lowering. We find that utilizing an operator selection criteria which takes into account both energy gradients and expected growth can substantially reduce the number of Pauli products in effective Hamiltonians used for a subsequent VQE optimization

Five factors contributing to severe rhabdomyolysis in a 21 yr old IV drug abuser: a case report

Rhabdomyolysis is a potentially life-threatening condition resulting from the release of large quantities of myocyte breakdown products into the circulation, following injury to striated muscles. There are several causes of rhabdomyolysis - traumatic and non-traumatic. We present a 21-year-old male intravenous drug abuser, who was referred to us with fever, altered sensorium and seizures. He developed severe rhabdomyolysis following a mixed meningeal infection by Streptococcus pneumoniae and Mycobacterium tuberculosis. This patient’s examination and investigation suggested a combination of factors leading to the severe rhabdomyolysis which proved fatal. The patient’s creatine phosphokinase was elevated to 167,000 U/L, following hyperpyrexia, seizures, meningitis (pneumococcal and tuberculous), pentazocine and alcohol abuse. The increase in mortality rate with the onset of rhabdomyolysis warrants immediate cessation of the insult and aggressive management

Factors influencing the stable carbon isotopic composition of suspended and sinking organic matter in the coastal Antarctic sea ice environment

A high resolution time-series analysis of stable carbon isotopic signatures in particulate organic carbon (&amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt;) and associated biogeochemical parameters in sea ice and surface waters provides an insight into the factors affecting &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in the coastal western Antarctic Peninsula sea ice environment. The study covers two austral summer seasons in Ryder Bay, northern Marguerite Bay between 2004 and 2006. A shift in diatom species composition during the 2005/06 summer bloom to near-complete biomass dominance of &lt;i&gt;Proboscia inermis&lt;/i&gt; is strongly correlated with a large ~10 &amp;permil; negative isotopic shift in &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; that cannot be explained by a concurrent change in concentration or isotopic signature of CO&lt;sub&gt;2&lt;/sub&gt;. We hypothesise that the &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; shift may be driven by the contrasting biochemical mechanisms and utilisation of carbon-concentrating mechanisms (CCMs) in different diatom species. Specifically, very low &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in &lt;i&gt;P. inermis&lt;/i&gt; may be caused by the lack of a CCM, whilst some diatom species abundant at times of higher &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; may employ CCMs. These short-lived yet pronounced negative &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; excursions drive a 4 &amp;permil; decrease in the seasonal average &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; signal, which is transferred to sediment traps and core-top sediments and consequently has the potential for preservation in the sedimentary record. This 4 &amp;permil; difference between seasons of contrasting sea ice conditions and upper water column stratification matches the full amplitude of glacial-interglacial Southern Ocean &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; variability and, as such, we invoke phytoplankton species changes as a potentially important factor influencing sedimentary &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt;. We also find significantly higher &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in sea ice than surface waters, consistent with autotrophic carbon fixation in a semi-closed environment and possible contributions from post-production degradation, biological utilisation of HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt; and production of exopolymeric substances. This study demonstrates the importance of surface water diatom speciation effects and isotopically heavy sea ice-derived material for &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in Antarctic coastal environments and underlying sediments, with consequences for the utility of diatom-based &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in the sedimentary record

Development of a Reference Set of Sorghum (\u3cem\u3eSorghum\u3c/em\u3e spp.) for Cyanogenic Potential (HCN-p) and Evaluating Their Fodder Yield Traits

Sorghum (Sorghum bicolor (L.) Moench) the fifth most important cereal crop of the world is also valued for its fodder and stover. In India, fodder sorghum is grown in 2.6 mha mainly in western UP, Haryana, Punjab, Rajasthan and Delhi and fulfils over two-third of the fodder demand. Sorghum has four desirable qualities viz., high dry matter yield, light, water and nitrogen use efficiency. Sorghum stover is valued over all other sources of fodder. Thus, sorghum is used as fodder to the domestic animals for its better performance. The projected demand for fodder in India in 2020 is expected to be 855 MT of green fodder, 526 MT of dry matter and 56 MT of concentrate feed (Dikshit and Birthal, 2010). In this perspective it is important to develop genotypes of high fodder yield and nutritive value. Cases of cyanide poisoning in animals feeding on sorghum forage have been reported in many parts of the country. HCN is absorbed into the blood stream very quickly and inhibits theanimal’s ability to deliver oxygen to tissue for cellular respiration. According to the Merck Veterinary Manual, the minimum lethal blood concentration level for HCN is approximately 3.0 μg/ml or less. It is highly desirable that the toxicity of cyanogenic plants to livestock be reduced. This is achievable by selective breeding, screeningof germplasm for low-HCN-p, mutagenesis and genetic engineering. With this background, the present investigation was contemplated among sorghum germplasm accessions to develop a reference set for cyanogenic potential (HCN-p). These accessions were also evaluated for fodder yield traits and entries with low HCN-p and high biomass were identified

Biogeochemical changes within the Benguela Current upwelling system during the Matuyama Diatom Maximum: Nitrogen isotope evidence from Ocean Drilling Program Sites 1082 and 1084

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95071/1/palo944.pd