34 research outputs found
Genetic dissection of itpr gene function reveals a vital requirement in aminergic cells of Drosophila larvae
Signaling by the second messenger inositol 1,4,5-trisphosphate is thought to affect several developmental and physiological processes. Mutants in the inositol 1,4,5-trisphosphate receptor (itpr) gene of Drosophila exhibit delays in molting while stronger alleles are also larval lethal. In a freshly generated set of EMS alleles for the itpr locus we have sequenced and identified single point mutations in seven mutant chromosomes. The predicted allelic strength of these mutants matches the observed levels of lethality. They range from weak hypomorphs to complete nulls. Interestingly, lethality in three heteroallelic combinations has a component of cold sensitivity. The temporal focus of cold sensitivity lies in the larval stages, predominantly at second instar. Coupled with our earlier observation that an itpr homozygous null allele dies at the second instar stage, it appears that there is a critical period for itpr gene function in second instar larvae. Here we show that the focus of this critical function lies in aminergic cells by rescue with UAS-itpr and DdCGAL4. However, this function does not require synaptic activity, suggesting that InsP3-mediated Ca2+ release regulates the neurohormonal action of serotonin
The Quantum Internet: A Hardware Review
In the century following its discovery, applications for quantum physics are
opening a new world of technological possibilities. With the current decade
witnessing quantum supremacy, quantum technologies are already starting to
change the ways information is generated, transmitted, stored and processed.
The next major milestone in quantum technology is already rapidly emerging --
the quantum internet. Since light is the most logical candidate for quantum
communication, quantum photonics is a critical enabling technology. This paper
reviews the hardware aspects of the quantum internet, mainly from a photonics
perspective. Though a plethora of quantum technologies and devices have emerged
in recent years, we are more focused on devices or components that may enable
the quantum internet. Our approach is primarily qualitative, providing a broad
overview of the necessary technologies for a large-scale quantum internet.Comment: 38 pages, 1 tabl
Integrated Photonic Platforms for Quantum Technology: A Review
Quantum information processing has conceptually changed the way we process
and transmit information. Quantum physics, which explains the strange behaviour
of matter at the microscopic dimensions, has matured into a quantum technology
that can harness this strange behaviour for technological applications with
far-reaching consequences, which uses quantum bits (qubits) for information
processing. Experiments suggest that photons are the most successful candidates
for realising qubits, which indicates that integrated photonic platforms will
play a crucial role in realising quantum technology. This paper surveys the
various photonic platforms based on different materials for quantum information
processing. The future of this technology depends on the successful materials
that can be used to universally realise quantum devices, similar to silicon,
which shaped the industry towards the end of the last century. Though a
prediction is implausible at this point, we provide an overview of the current
status of research on the platforms based on various materials.Comment: 48 pages, 3 figure
Single and Multi-dimensional Integrated optic Photon sources for Quantum communication
We present an on-chip nonlinear optics based correlated and higher dimensional state photon source using silicon hybrid materials. The four-wave mixing process occurring in a ring resonator is used to generate a frequency comb of signal and idler wavelengths corresponding to different resonant wavelengths around the pump resonance. The frequency comb based four-wave mixing process is used to generate higher-dimensional entangled photon pairs. The individual comb lines, into which the correlated photon pairs could be generated leads to higher dimensional entanglement. The ability to generate higher dimensional photon states is advantageous to pack more information for high data rate quantum communication and information processing applications
Analysis of Nonlinear Optical Properties of Photonic Crystal Beam-splitters
The paper analyses electromagnetic wave propagation through nonlinear photonic crystal beam-splitters. Different lattice configurations of Y-junction beam-splitters are simulated and propagation properties are investigated with introducing nonlinearity with varying the rod size in crystal lattice. It is seen that nonlinear photonic crystal shows a considerable band-gap even at low refractive contrast. The division of power in both arms of beam-splitters can be controlled by varying the nonlinearity
Integrated Optics-Based Quantum Communication Devices
Quantum communication or more specifically quantum information processing is considered as the future of information science and technology. In this paper we propose a scheme to implement quantum communication at the device level using integrated optics. We implement the quantum communication protocol BB84, in a waveguide based circuit using integrated optics. We also propose a high dimensional quantum key distribution method implementation using integrated optics. In the earlier one polarized photons are used as the carriers of quantum information, while in second one electromagnetic modes in the waveguide are used to carry quantum information. The high dimensional quantum communication method is used to increase the information content of protocol thus increasing on the data rates. This is done by encoding into a larger state space. We have used electromagnetic modes for encoding since the polarization method is not efficient to carry information in a larger state space
Visual impairment among weaving communities in Prakasam district in South India.
PURPOSE: To assess the prevalence and causes of visual impairment in weaving communities in Prakasam district in South India state of Andhra Pradesh. METHODS: Using Rapid Assessment of Visual Impairment (RAVI) methodology, a population based cross-sectional study was conducted. A two-stage sampling strategy was used to select 3000 participants aged ≥40 years. Visual Acuity (VA) was assessed using a tumbling E chart and ocular examinations were performed by trained Para medical ophthalmic personnel. A questionnaire was used to collect personal and demographic information. Blindness and moderate Visual Impairment (VI) was defined as presenting VA <6/60 and <6/18 to 6/60 respectively. VI included blindness and moderate VI. RESULTS: 2848 of 3000 enumerated subjects (94.0%) participated. 39% were in 40-49 years age group and 11.8% were aged ≥70 years, 55% were women and nearly half of them had no formal education. 400 (14%; 95% CI: 12.8-15.3) subjects had VI, including blindness in 131 (4.6%; 95% CI: 3.8-5.4) and moderate VI in 269 (9.4%; 95% CI: 8.3-10.5) individuals. On applying multiple logistic regression, VI was significantly associated with older age and no formal education. Though the odds of having VI were higher in females, it was of borderline statistical significance (p = 0.06). Refractive error was the leading cause of all VI followed by cataract (56%). However, refractive errors were the leading cause of moderate VI (73.2%) and cataract was the leading cause of blindness (62.6%). 'Cannot afford the cost of services' was the leading barrier for utilization of eye care services (47%). CONCLUSIONS: There is a significant burden of VI in weaving communities in Andhra Pradesh, India most of which is avoidable. With this information as baseline, services need to be streamlined to address this burden
Synthesis of Triazolo Isoquinolines and Isochromenes from 2‑Alkynylbenzaldehyde via Domino Reactions under Transition-Metal-Free Conditions
We
describe two simple straightforward syntheses of triazolo isoquinolines
(<b>3</b>) and isochromenes (<b>7</b>) from 2-alkynylbenzaldehydes
(<b>1</b>) as a common synthon. The synthetic strategy for <b>3</b> involves formation of the (<i>E</i>)-1-(2-nitrovinyl)-2-(alkynyl)benzene
species <b>2</b> via condensation of synthon <b>1</b> with
nitromethane followed by a [3 + 2] cycloaddition/extrusion of the
nitro group/regioselective 6-endo cyclization domino sequence. In
yet another strategy, the synthon <b>1</b> was condensed with
nitromethane followed by electrophilic iodo cyclization of the resulting
2-nitro-1-(2-(alkynyl)phenyl)ethanol (<b>6</b>) to furnish iodo
isochromene derivatives. The salient feature of the above two strategies
involves formation of the corresponding heterocycles under metal-free
conditions in good yields
Not Available
Not AvailableQuantifying the yield potential of maize at any given site is a key to understand the existing yield
gaps and to identify the most important constraints in achieving optimal yield and profit. A well parameterized
and validated APSIM model was used to assess the productivity and yield gap of maize cv Kanchan 101
from multi-year long-term and completed experiments. A total of 30 districts with 74 soil profiles of
Madhya Pradesh were considered for the study. For the 30 selected sites, the rainfed potential yield of
maize (Ywp) ranged from 3.3 to 5.2 t ha-1 whereas the districts mean yield (Yf) ranged from 0.7 to 3.1 t ha1
giving yield gaps ranging from 1.7 to 3.1 t ha-1. It was observed from the long-term simulation study that
there is a good potential to improve the grain yield of maize crop by 3.0 t ha-1 provided optimum dates of
sowing and good management practices are followed in the state.Not Availabl
Not Available
Not AvailableQuantifying the yield potential of maize at any given site is a key to understand the existing yield
gaps and to identify the most important constraints in achieving optimal yield and profit. A well parameterized
and validated APSIM model was used to assess the productivity and yield gap of maize cv Kanchan 101
from multi-year long-term and completed experiments. A total of 30 districts with 74 soil profiles of
Madhya Pradesh were considered for the study. For the 30 selected sites, the rainfed potential yield of
maize (Ywp) ranged from 3.3 to 5.2 t ha-1 whereas the districts mean yield (Yf) ranged from 0.7 to 3.1 t ha-
1 giving yield gaps ranging from 1.7 to 3.1 t ha-1. It was observed from the long-term simulation study that
there is a good potential to improve the grain yield of maize crop by 3.0 t ha-1 provided optimum dates of
sowing and good management practices are followed in the state.Not Availabl