A Dynamic Resource Allocation Methodology for Large Technology-Based Organizations

This thesis presents a generalized framework for research and development (R&D) management, the Dynamic Resource Allocation Methodology (DRAM) for use in large technology based organizations. The research effort provides an assessment of major issues in R&D allocation and the Zero-Base Budgeting (ZBB), and a test of applicability of DRAM to solar energy research, development and demonstration (RD&D) programs. DRAM utilizes: (1) Strategic Program Activity Networks (SPAN) to identify interdependencies, multi-period costs of development, and alternative funding levels analysis required by ZBB; (2) Goal Programming (GP) and Dynamic Programming (DP) approaches to determine funding levels for subsystems, and to select technical approaches such that the organization can determine optimum risk level and subsystem goals; (3) Eigenvalue prioritization to determine relative importance of multiple criteria, and a scoring model to determine priorities of technology options; and (4) GP and DP approaches to allocate resources to technology options in the ZBB process

Sacralization of lumbar vertebrae-prevalence and association with low back ache and radiculopathy

Background: Low back pain (LBP) is a prevalent condition, often associated with various anatomical anomalies, including lumbar sacralization, that is, the fusion of the fifth lumbar vertebra (L5) with the sacrum. This study aims to evaluate the prevalence of sacralization among LBP patients and its relationship with radiculopathy. Methods: A retrospective study was conducted at the department of orthopaedics, Justice KS Hegde charitable hospital, from January 1, 2023, to July 31, 2024. Patients aged 18-75 years presenting with LBP who underwent lumbosacral radiographs were included. Demographic and clinical data were collected, and sacralization types were classified using the Castellvi system. Statistical analyses were performed using the chi-square test. Results: Among 771 radiographs analysed, the prevalence of sacralization was 10.1%. Most subjects were over 41 years old (81.6%), with a majority being female (54.5%). Type I A was the most common form of sacralization (30.77%). A significant association between sacralization and radiculopathy was observed, with 70 of the 78 subjects with sacralization experiencing radiculopathy (p<0.0005). Conclusions: This study indicates a noteworthy association between sacralization and radiculopathy in patients with LBP. Given the low prevalence of sacralization, the findings emphasize the importance of recognizing anatomical variations in clinical evaluations of patients with low back ache, particularly in older populations. Further research is warranted to explore the implications of these anatomical anomalies on treatment strategies and patient outcomes

Next-Generation Solid-State Quantum Emitters

This thesis details two types of deterministic solid-state quantum emitters, an optically-driven quantum dot source in a tapered nanowire waveguide, and an electrically-driven source implemented by integrating a single-electron pump into a two-dimensional p-n junction. A finite-difference time-domain model of the optically-driven nanowire quantum dot source yielded optimized architectural parameters required to obtain a high transmission efficiency and a Gaussian far-field emission profile. An additional model of an electrically-gated nanowire source examined the effect of the surrounding structures on the emission properties of the source. A successfully working prototype p-n junction device as a precursor to the electrically-driven quantum emitter was implemented by simultaneously inducing positive and negative two-dimensional carrier gases in an undoped semiconductor heterostructure. This device, fabricated in-house, offers a path forward in the development of a new class of bright, deterministic sources of single- and entangled-photons

The Neural and Molecular Mechanisms Regulating Male Locomotion during Caenorhabditis elegans Mating Behavior

In key survival behaviors like predator-prey interactions and mating, animals have to integrate dynamic sensory inputs from a moving target and regulate their motor outputs on moment-to-moment basis. The molecular underpinnings of such goal-oriented behaviors are not well understood because of the genomic and neural system complexities of many animals. Here I take advantage of the anatomical simplicity of the nematode worm Caenorhabditis elegans and its amenability to optogenetics to interrogate the neural mechanisms underlying male mating behavior. Male mating is a goal oriented behavioral sequence and serves as a useful paradigm for exploring neural control of sex-specific behaviors, behavioral sequence execution and decision-making. When not engaged in mating the male, like the hermaphrodite, explores his environment with predominantly forward locomotion. However, when the male contacts a potential mate he immediately places his tail against her surface and searches for the vulva, moving backwards. Male-specific sensory rays of the tail are responsible for sensing mate contact, inducing tail apposition and backward movement. Using a combination of cell-specific laser ablation, optogentics and mutant analyses, I show that the male exploits the sex-shared locomotory system to control his mating movement. The rays exert their affect by acting through at least two downstream pathways. One pathway is defined by male-specific interneurons PVY and PVX which activate backward command interneurons AVA(L/R) and shift the directional bias to backward. This AVA activation is mediated by cholinergic receptor subunits ACR-18, ACR-16 and UNC-29, which is an atypical mode for command interneuron regulation. The second pathway is defined by male-specific interneurons EF1-3. EFs may promote backing by inhibiting sex-shared AVB(L/R) forward command interneurons. Upon vulva detection by the hook sensilla, locomotion ceases by the redundant action of hook neurons HOA and HOB. Surprisingly, PVY/PVX and EFs activity is required for holding the tail at the vulva. Taken together these data suggest that a distributed processing strategy underlies male’s accurate, rapid and robust movement control during mating. The male-specific nature of his behavior is due male-specific control of sex-shared circuitry. Conceivably, similar design and processing strategies may underlie the circuitry controlling analogous behaviors in more complex nervous systems

Bilateral neck of femur stress fracture secondary to osteopetrosis treated with dynamic hip screw

Osteopetrosis, a rare hereditary bone disorder, is characterized by increased bone density due to defective osteoclast-mediated bone resorption. This condition often leads to skeletal fragility, resulting in recurrent fractures despite increased bone mass. Among these, stress fractures of the femoral neck pose a unique challenge where conventional management may not be optimal. Valgus osteotomy offers a viable surgical intervention to realign the mechanical axis, thereby reducing stress on the femoral neck and facilitating healing. This paper reviews the pathophysiology of osteopetrosis, its impact on fracture healing, and the role of valgus osteotomy in managing femoral neck stress fractures in osteopetrotic patients

Multiple doublesex-Related Genes Specify Critical Cell Fates in a C. elegans Male Neural Circuit

In most animal species, males and females exhibit differences in behavior and morphology that relate to their respective roles in reproduction. DM (Doublesex/MAB-3) domain transcription factors are phylogenetically conserved regulators of sexual development. They are thought to establish sexual traits by sex-specifically modifying the activity of general developmental programs. However, there are few examples where the details of these interactions are known, particularly in the nervous system.In this study, we show that two C. elegans DM domain genes, dmd-3 and mab-23, regulate sensory and muscle cell development in a male neural circuit required for mating. Using genetic approaches, we show that in the circuit sensory neurons, dmd-3 and mab-23 establish the correct pattern of dopaminergic (DA) and cholinergic (ACh) fate. We find that the ETS-domain transcription factor gene ast-1, a non-sex-specific, phylogenetically conserved activator of dopamine biosynthesis gene transcription, is broadly expressed in the circuit sensory neuron population. However, dmd-3 and mab-23 repress its activity in most cells, promoting ACh fate instead. A subset of neurons, preferentially exposed to a TGF-beta ligand, escape this repression because signal transduction pathway activity in these cells blocks dmd-3/mab-23 function, allowing DA fate to be established. Through optogenetic and pharmacological approaches, we show that the sensory and muscle cell characteristics controlled by dmd-3 and mab-23 are crucial for circuit function.In the C. elegans male, DM domain genes dmd-3 and mab-23 regulate expression of cell sub-type characteristics that are critical for mating success. In particular, these factors limit the number of DA neurons in the male nervous system by sex-specifically regulating a phylogenetically conserved dopamine biosynthesis gene transcription factor. Homologous interactions between vertebrate counterparts could regulate sex differences in neuron sub-type populations in the brain

Stable electroluminescence in ambipolar dopant-free lateral p-n junctions

Dopant-free lateral p-n junctions in the GaAs/AlGaAs material system have attracted interest due to their potential use in quantum optoelectronics (e.g., optical quantum computers or quantum repeaters) and ease of integration with other components, such as single electron pumps and spin qubits. A major obstacle to integration has been unwanted charge accumulation at the p-n junction gap that suppresses light emission, either due to enhanced non-radiative recombination or inhibition of p-n current. Typically, samples must frequently be warmed to room temperature to dissipate this built-up charge and restore light emission in a subsequent cooldown. Here, we introduce a practical gate voltage protocol that clears this parasitic charge accumulation, in-situ at low temperature, enabling the indefinite cryogenic operation of devices. This reset protocol enabled the optical characterization of stable, bright, dopant-free lateral p-n junctions with electroluminescence linewidths among the narrowest (< 1 meV; < 0.5 nm) reported in this type of device. It also enabled the unambiguous identification of the ground state of neutral free excitons (heavy and light holes), as well as charged excitons (trions). The free exciton emission energies for both photoluminescence and electroluminescence are found to be nearly identical (within 0.2 meV or 0.1 nm). The binding and dissociation energies for free and charged excitons are reported. A free exciton lifetime of 237 ps was measured by time-resolved electroluminescence, compared to 419 ps with time-resolved photoluminescence.Comment: Main text: 5 pages and 5 figures. Supplementary: 18 pages and 11 figure

Pulsed Electroluminescence in a Dopant-free Gateable Semiconductor

We report on a stable form of pulsed electroluminescence in a dopant-free direct bandgap semiconductor heterostructure that we coin the tidal effect. Swapping an inducing gate voltage in an ambipolar field effect transistor allows incoming and outgoing carriers of opposite charge to meet and recombine radiatively. We develop a model to explain the carrier dynamics that underpins the frequency response of the pulsed electroluminesence intensity. Higher mobilities enable larger active emission areas than previous reports, as well as stable emission over long timescales.Comment: Main text: 5 pages, 4 figures. Supplementary: 7 pages, 5 figure