Exploring the Impact of Extra Dimensions on Neutron Star Structure and Equation of State

In this work, we explore the impact of higher dimensional spacetime on the stellar structure and thermodynamic properties of neutron stars. Utilizing the density-dependent relativistic hadron field theory, we introduce modifications to incorporate the influence of higher dimensionality, a novel approach not explored in existing literature to our best knowledge. Our methodology involves solving the essential stellar structure equations in D-dimensional spacetime ($D \geq 4$), starting with the modification of the Einstein-Hilbert action, derivation of the Einstein field equation in D dimensions, and application of the resulting exterior Schwarzschild spacetime metric for D-dimension. Our findings reveal that with incremental dimensions, the central density $\rho_{c} G_D$ and central pressure $p_c G_D$ gradually increase, leading to progressively stiffer neutron matter. Incremental dimensionality also results in a gradual increase in the maximum mass attained, limited to our study between $D=4$ and $D=6$, as no maximum mass value is obtained for $D>6$. We consistently observe the criteria $dM/d\rho_c>0$ fulfilled up to the maximum mass point, supported by stability analysis against infinitesimal radial pulsations. The validity of our solution is confirmed through causality conditions, ensuring that the matter sound speed remains within the speed of light for all cases. Additionally, our examination indicates that the total mass-to-radius ratio for all discussed D-dimensional cases comfortably resides within the modified Buchdahl limit, which exhibits the physical validity of achieved results.Comment: 12 pages, 7 figures, 3 table

HIV Transmission Potential Among Local and Migrant Factory Workers in Kolkata, India

Migrant workers in India play a key role in the spread of HIV. Kolkata is a common destination for workers, who may acquire infection and transmit it to their wives and/or other sexual partners. We investigated sexual relations and condom use by factory workers. Migrant and local factory workers were randomly selected from five wards of Kolkata. Information was collected about demographic and socio-economic characteristics, sexual relationships, condom usage, and perceptions and intent to use condoms. Condom use was very low in both groups of workers, particularly among migrants. Many married workers visited female sex workers but never used condoms. Few intended to use condoms, and if they did, it did not always translate into actual usage. There is great potential for transmission of HIV/sexually transmitted infections by these workers. Carefully designed intervention and education programs in the context of low literacy and cultural norms are urgently needed

Multi-band Extension of the Wideband Timing Technique

The wideband timing technique enables the high-precision simultaneous estimation of Times of Arrival (ToAs) and Dispersion Measures (DMs) while effectively modeling frequency-dependent profile evolution. We present two novel independent methods that extend the standard wideband technique to handle simultaneous multi-band pulsar data incorporating profile evolution over a larger frequency span to estimate DMs and ToAs with enhanced precision. We implement the wideband likelihood using the libstempo python interface to perform wideband timing in the tempo2 framework. We present the application of these techniques to the dataset of fourteen millisecond pulsars observed simultaneously in Band 3 (300 - 500 MHz) and Band 5 (1260 - 1460 MHz) of the upgraded Giant Metrewave Radio Telescope (uGMRT) as a part of the Indian Pulsar Timing Array (InPTA) campaign. We achieve increased ToA and DM precision and sub-microsecond root mean square post-fit timing residuals by combining simultaneous multi-band pulsar observations done in non-contiguous bands for the first time using our novel techniques.Comment: Submitted to MNRA

A rain forest dusk chorus: cacophony or sounds of silence?

A rain forest dusk chorus consists of a large number of individuals of acoustically communicating species signaling at the same time. How different species achieve effective intra-specific communication in this complex and noisy acoustic environment is not well understood. In this study we examined acoustic masking interference in an assemblage of rain forest crickets and katydids. We used signal structures and spacing of signalers to estimate temporal, spectral and active space overlap between species. We then examined these overlaps for evidence of strategies of masking avoidance in the assemblage: we asked whether species whose signals have high temporal or spectral overlap avoid calling together. Whereas we found evidence that species with high temporal overlap may avoid calling together, there was no relation between spectral overlap and calling activity. There was also no correlation between the spectral and temporal overlaps of the signals of different species. In addition, we found little evidence that species calling in the understorey actively use spacing to minimize acoustic overlap. Increasing call intensity and tuning receivers however emerged as powerful strategies to minimize acoustic overlap. Effective acoustic overlaps were on average close to zero for most individuals in natural, multispecies choruses, even in the absence of behavioral avoidance mechanisms such as inhibition of calling or active spacing. Thus, call temporal structure, intensity and frequency together provide sufficient parameter space for several species to call together yet communicate effectively with little interference in the apparent cacophony of a rain forest dusk chorus

Neuropathological spectrum of Rasmussen encephalitis

Background: Rasmussen encephalitis (RE) is a chronic epileptic disorder of unknown etiology, and is clinically characterized by progressive neurological deterioration, focal seizures often progressing to intractable epilepsy, cognitive decline and hemispheric atrophy. Aims: We report the spectrum of neuropathological changes seen in RE, and discuss the evolutionary mechanisms of this disease. Materials and Methods: Surgically obtained specimens from RE patients diagnosed during 2002-2004 at this institute were evaluated for the presence and extent of different histopathological features of RE. The H&E and immunohistochemistry stained slides were also evaluated for the type and distribution pattern of inflammatory infiltrates, along with a semiquantitative evaluation for the severity of inflammation. Results: Four cases of RE were admitted during the study period, all of which presented with partial seizures with successive deterioration to intractable epilepsy. The age at onset varied between 5 and 10 years (mean 7.8 years), with three male and one female patients. Subsequently, all four patients underwent hemispherotomy. Histopathological features of perivascular lymphocytic infiltrate, neuronal loss, microglial nodules, and reactive astrocytosis, with or without evidence of neuronophagia confirmed a diagnosis of RE. These cases also had varying degrees of T-cell-rich (CD3-positive) inflammatory infiltrates and CD68-immunopositive microglial proliferation. It was observed that the severity of inflammation had a trend to inversely correlate with the duration of symptoms. Conclusion: It is proposed that an accurate evaluation and histopathological grading of these lesions may possibly have a role in patient prognostication

Original Article - Neuropathological spectrum of Rasmussen encephalitis

Background : Rasmussen encephalitis (RE) is a chronic epileptic disorder of unknown etiology, and is clinically characterized by progressive neurological deterioration, focal seizures often progressing to intractable epilepsy, cognitive decline and hemispheric atrophy. Aims : We report the spectrum of neuropathological changes seen in RE, and discuss the evolutionary mechanisms of this disease. Materials and Methods : Surgically obtained specimens from RE patients diagnosed during 2002-2004 at this institute were evaluated for the presence and extent of different histopathological features of RE. The H&E and immunohistochemistry stained slides were also evaluated for the type and distribution pattern of inflammatory infiltrates, along with a semiquantitative evaluation for the severity of inflammation. Results : Four cases of RE were admitted during the study period, all of which presented with partial seizures with successive deterioration to intractable epilepsy. The age at onset varied between 5 and 10 years (mean 7.8 years), with three male and one female patients. Subsequently, all four patients underwent hemispherotomy. Histopathological features of perivascular lymphocytic infiltrate, neuronal loss, microglial nodules, and reactive astrocytosis, with or without evidence of neuronophagia confirmed a diagnosis of RE. These cases also had varying degrees of T-cell-rich (CD3-positive) inflammatory infiltrates and CD68-immunopositive microglial proliferation. It was observed that the severity of inflammation had a trend to inversely correlate with the duration of symptoms. Conclusion : It is proposed that an accurate evaluation and histopathological grading of these lesions may possibly have a role in patient prognostication

Fusion Imaging: The Double Impact

The principal aim of diagnostic imaging is to evaluate the true extent of disease to best determine surgical and therapeutic options. Pretherapeutic radiological tumor staging includes evaluation of the size, location and extent of the primary tumor and infiltration into surrounding vascular, visceral and bony structures. Computed tomography, magnetic resonance imaging, positron-emission tomography, etc. are the diagnostic procedures used commonly have certain limitations. Linking functional and anatomic image data via fusion of PET and CT/MR, or use of combined PET/CT imaging provides additional clinically relevant information. It may be the modality of choice because it almost completely eliminates the false-positive and false-negative PET findings

Neuropathological spectrum of lesions associated with intractable epilepsies: a 10-year experience with a series of 153 resections

Background: Surgical management of intractable epilepsies is currently an established mode of therapy in various clinical settings. Aims: To retrospectively evaluate the neuropathological findings in both temporal and extratemporal lobe resections in such patients. Materials and Methods: The study included resected specimens from patients with intractable epilepsy managed at a tertiary care hospital of India, during a 10-year period (1995-2004). Results: A total of 153 patients, with mean age of 19.4 years and male predominance (73.2%) were included in the study. Overall, there was a predilection for the temporal lobe (73.2%), while 41cases were extratemporal in location. On histopathology, mesial temporal sclerosis (MTS) (24.8%) was the commonest lesion, followed by tumors (19.6%) and isolated focal cortical dysplasia (FCD-15.11%). Other less common findings included Rasmussen encephalitis, non-specific gliosis and vascular malformations. In addition, 20.9% (32 cases) had dual lesions, majority of which included FCD with ganglioglioma (15 cases) or with dysembryoplastic neuroepithelial tumor (12 cases). In the temporal lobe, neoplasms and dual lesions formed the majority (apart from MTS), unlike dual lesions followed by neoplasms and FCD, in the extratemporal location. Conclusion: This series demonstrates that most patients with chronic intractable epilepsy have significant histopathological findings and highlights the neuropathological spectrum of such lesions, in the Indian context. This was similar to that reported from the West, but different from the single Indian series available in the literature. Further, the overall profile of temporal lobe lesions was not different from the extratemporal ones