Northeast India Research Articles

Unveiling the effect of leaf maturity on biochemical constituents and quality of CTC black tea: insights from Northeast India’s commercial cultivars

Unveiling the effect of leaf maturity on biochemical constituents and quality of CTC black tea: insights from Northeast India’s commercial cultivars

Characterization of the viral genome of Omicron variants of SARS-CoV-2 circulating in Tripura, a remote frontier state in Northeastern India.

From 2020, with advent of COVID-19 pandemic, Tripura has experienced SARS-CoV-2 viral evolution in accordance with other parts of India. Since January 2022, the Omicron variant of SARS-CoV-2 virus became the predominant lineage circulating in India and neighboring countries. This study characterizes the viral genome of the omicron variant circulating in the state since its inception to June, 2023. The current study was performed on nasopharyngeal and oropharyngeal samples received from the various departments of AGMC, as well as eight district hospitals from Tripura. The positive samples with a cycle threshold value of 25 or less for the E and/or N gene were considered for whole genome sequencing using Illumina Miseq NGS platform. Majority of the sequences belonged to Clade 21L, with BA.5.2 being the major sub variant detected during the study period. Majority of the mutations were detected in the Spike protein region, including L24-, P25-, P26-, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, S477N, T478K, Q498R, Y505H, Q954H and N969K. All the sequences uniquely showed the mutations A27S and G142D in N terminal domain in Spike protein, not being reported from other Indian sequences like BA.5 variants. T9I, A63T and P13L were major substitutions in E, M and N protein regions respectively. Escape of mutants from vaccine induced immunity was mostly observed in BA.2 sub variants, majority endowed with the triplet mutation of K417N + E484K + N501Y. The current study indicates that Omicron variants circulating in the state of Tripura is comparable to other regions of India and the neighbouring country of Bangladesh. Genetic mutations increasing viral transmissibility have been identified in the circulating viral genomes.

Contemporary Development Discourse in Northeast India and its Impact on the Tribal Communities

Northeast India, a region characterised by great geo-political and ecological significance, is geographically divided into the plains and the hills and is home to many tribal communities that largely depend on natural resource-based livelihoods. While shifting cultivation (jhum) has been a dominant traditional system of land use among tribes both in the hills and the plains, most of them in the plains abandoned this practice on account of colonial-era encroachment. In the hills, however, shifting cultivation still plays a critical role in maintaining agricultural biodiversity and providing food security to the indigenous communities. The advent of colonial development in the region in the 19th century left a long-term impact on its natural and social landscapes. After independence, especially after the early 1960s, the hills that remained largely excluded from the process of colonial development were also brought under the development agenda of the Indian state. However, in recent times, under the neoliberal Indian state, the development discourse in the region has witnessed an unprecedentedly aggressive character seriously undermining the traditional ecology, land ownership system, livelihood and culture of the tribal communities.

Marketing of Small Business with Regard to Handloom Sector

The present paper explores the marketing practices of handloom based small business enterprises in India. It is assumed that marketing plays an immense role in promoting as well as preserving handloom products. Handloom sector plays a vital role in preservation of traditional craftmanship and also provides job opportunities for the weavers specially women in case of Northeast India. Hence, it is a sector that makes women an empowered and self- reliant person. Small businesses in the handloom sector use a variety of marketing strategies which includes both traditional and modern approaches. Small business in handloom sector face different challenges in marketing of their products.

Reconfiguring the Tribe: Changing Ethnic Affiliations in India’s Northeast

This essay sees the form and functioning of the Zeliangrong Naga community as a work in progress. Rather than a perennial, historically immutable and delimited entity, the (relatively recent) formation of the Zeliangrong community indicates that tribes can be formed afresh and that tribal identities are constantly in flux. I begin by tracing and placing the origins of the Zeliangrong Naga as told by Zeliangrong elders and circulating origin and migration stories. Then, continuing my focus on ethnic alignment and realignment, I studied the Zeliangrong movement that emerged in the 1920s. At first, they advocated a Naga Raj through the ousting of the colonial government. Over time, however, this rebellion changed direction and reduced its ambitions to the creation of a Zeliangrong homeland that would unite the Zeliangrong people who currently inhabit three different states of Northeast India, namely Manipur, Nagaland and Assam. Drawing both on historical analysis and fresh ethnography this essay shows how over time the Zeliangrong ethnic identity has come under strain and is increasingly internally contested with its constituent parts now expressing divergent political aspirations while also struggling over status, standing and dominance within.

New photographic and distribution records of the Beautiful Nuthatch Sitta formosa (Blyth, 1843) and Lesser Adjutant Leptoptilos javanicus (Horsfield, 1821) from the Tsirang District landscape in Bhutan

The distribution records with photographic evidence of the Beautiful Nuthatch Sitta formosa (Blyth, 1843) and Lesser Adjutant Leptoptilos javanicus (Horsfield, 1821) from the Tsirang District landscape in Bhutan. S. formosa, under Sittidae family, was first described in 1843 and is native to the eastern Himalaya, northeastern India, and extending into southeastern Asia. L. javanicus being widely distributed is rare and faces threats from deforestation, leading to its vulnerable status. The largest wading bird in the Ciconiidae family, found mainly in southern and southeastern Asia, with a recent sighting in Tsirang District establishing new distribution records for Bhutan. The district’s ecological diversity, including broadleaved forests, and riverine landscapes, supports a rich avifauna, making it a hotspot for bird enthusiasts. Separate studies are required to ensure the long-term conservation of Beautiful Nuthatch, and to confirm whether Lesser Adjutant is a regular visitor in Tsirang.

Evaluation of Promising Lines of Lai Patta (Brassica juncea var rugosa L.) Suitable for Cultivation in North Eastern India

The present study was carried out with ten accessions of laipatta (Brassica juncea var rugosa L.) in Assam Agricultural University, Jorhat in order to identify suitable high yielding variety(s) with desirable quality characters. The accessions viz., JorMLG-1, JorMLP-2, MLG-3, MLP-4, MLG-5, MLP-6, ShLG-7, KjLP-8, ChL-9 (Check), and KL-10(Check) were collected from different districts of Assam and North East. They were evaluated consecutively for three years in station trials in the Dept. of Horticulture, AAU, Jorhat for plant yield and other quantitative and quality characters. The accessions were tested in Multilocation trials in five research stations. In these trials. among all genotypes JorMLG-1 and JorMLP-2 were found to be the best for plant yield and other component characters. The On Farm trials conducted in 12 farmers’ fields in Jorhat and Kokrajhar districts of the state exhibited average plant yield of 350.1 q/ha in JorMLG-1 and 318.2 q/ha in JorMLP-2 with 34 – 48% yield increase over the best check variety (ChL-9). JorMLG-1was a green leaf variety whereas JorMLP-2 was a greenish purple variety. The edible leaves could be harvested upto 60 days in JorMLG-1 and 55 days in JorMLP-2 after transplanting till the initiation of bolters. However, the best check variety ChL-9 showed bolting at 25 days after transplanting. Estimation of quality characters revealed 147.6 mg ascorbic acid, 186 mg calcium and 11.21 mg iron per 100g in JorMLG-1 whereas 145.2 mg ascorbic acid, 176 mg calcium and 10.61 mg iron per 100g in JorMLP-2. They have been recommended in the Zonal Research Committee Meeting and Annual Technical Committee Meeting held at Assam Agricultural University, Jorhat during 2019-20 for release in the state of Assam. In view of yield performance, consumer preference and taste, the varieties are spreading very fast and getting popularity throughout entire NE states. However, more study is required on quality traits, genetic parameters and molecular aspects.

Examining thedrivers of forest cover change and deforestation susceptibility in Northeast India using multicriteria decision-makingmodels.

The increasing rates of forest cover change and heightened vulnerability to deforestation present significant environmental challenges in Northeast India. This study investigates the dynamics of forest cover changeand susceptibility to deforestation in this region from 2001 to 2021, utilizing data from the Hansen Global Forest Change (HGFC) productonthe Google Earth Engine (GEE) platform. A suite of multicriteria decision-making (MCDM) models-including VlseKriterijumska optimizacija I Kompromisno Resenje (VIKOR), Simple Additive Weighting (SAW), Evaluation Based on Distance from Average Solution (EDAS), and Weighted Aggregates Sum Product Assessment (WASPAS)-was employed to assess changes in forest cover and deforestation susceptibility across varied zones. Multicollinearity tests confirmed the relevance of the factors influencing deforestation. Statistical validations, such as the Wilcoxon Signed Ranks Test, underscored the models' robustness, revealing statistically significant outcomes. Additionally, Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) analysis demonstrated the superior fit of the VIKOR model (AUC = 0.938) compared to SAW (AUC = 0.901), EDAS (AUC = 0.895), and WASPAS (AUC = 0.864) in predicting current deforestation susceptibility. Validation affirmed the reliability of all MCDM methods, with VIKOR displaying high sensitivity (True Positive Rate, TPR = 0.878) and optimal AUC (0.938). Correlation analyses among the models identified significant inter-relationships, notably a positive correlation between EDAS and SAW, and a negative correlation between VIKOR and SAW. The regions of Assam, Nagaland, Mizoram, and Arunachal Pradesh were identified as experiencing significant forest cover loss, indicating a pronounced susceptibility to future deforestation. These findings underscore the need for immediate intervention to address this critical environmental issue.

Rise of Populism in Northeast India: A Case of Assam

Rise of Populism in Northeast India: A Case of Assam

Insights into Citrus limon (L.) Osbeck peel essential oil from NE India: A study of its pharmacological properties and chemical composition

Citrus limon (L.) Osbeck is considered as one of the most significant horticultural as well as essential oil crop. However, the significance of the fruit peels left after the utilization of the sour fruit find limited importance and these leftover peels are rich in essential oil. Lemon peel essential oil (LPEO) finds used in the fragrance, food, cosmetic, and pharmaceutical industries. In this study lemon peel were used for isolation of essential oil by hydro-distillation, analyzed by GC-FID and GC-MS and was further subjected to in vitro anti-oxidant (DPPH, ABTS), anti-inflammatory, anti-tyrosinase, genotoxicity and anti-diabetic assays. The essential oil analysis has revealed limonene as major compound (38.08%) along with other minor compounds namely, α-citral (12.02%), decanal (8.14%) and neral (7.36%). The total amount of citral (α-citral and neral) was found to be 19.38%, comparatively higher compared to previous reports. LPEO was found to exhibit very strong tyrosinase inhibition activity along with good alpha-amylase inhibition. The results from this study further strengthen the immense potential of LPEO as an anti-diabetic and skin whitening agent. The results framed from this study will further strengthen the position of earlier works on biological activities of C. limon besides providing a descriptive work on the potential of Assam LPEO.

Evaluating the reliability and validity of the Strengths and Difficulties Questionnaire in a heterogeneous ethnic young cohort from northeast India

Abstract Introduction: The strengths and difficulties questionnaire (SDQ) is extensively utilized to assess adolescent psychosocial problems. Despite its global use, the instrument’s reliability and validity across diverse ethnic populations remain under-examined. This study evaluates the reliability and validity of the SDQ among adolescents from an ethnic young cohort from Northeast India. Methodology: The present study followed a cross-sectional descriptive study design. The population for the study comprised children aged 13–17 years, studying in various government and public schools located in districts in Northeast India. In this study, a total sample size of 400 participants was selected. The SDQ was used. The researcher used the Statistical Package for the Social Sciences (SPSS) version 23 to analyze and measure the data. The study was undertaken with the approval of the scientific committee and ethical committee. Results: The internal consistency of the SDQ, as indicated by a Cronbach’s α of 0.846, suggests high reliability. Exploratory factor analysis identified five distinct factors from the SDQ items, with Bartlett’s Test of Sphericity and the Kaiser–Meyer–Olkin (KMO) measure confirming the appropriateness of factor analysis (χ² =1880, df = 276, P < 0.001; KMO = 0.848). Factors were deemed significant with loadings ≥0.3. Conclusion: The findings affirm the SDQ’s reliability and factor structure within this multiethnic context of Northeast India, underscoring its potential as a valid tool for screening psychosocial issues among diverse ethnic groups. This validation enhances the SDQ’s applicability for mental health assessments and interventions across varied Indian ethnicities.

Novel genetic variants of banana streak MY virus and banana streak IM virus naturally infecting banana in Northeast India.

Divergent banana streak viruses (BSV) were characterized from banana plants exhibiting diverse symptoms in the Northeast region (NER) of India. Using rolling circle amplification (RCA), the complete genome sequences of seven episomal banana streak MY virus (BSMYV) isolates, including two novel variants, and two new banana streak IM virus (BSIMV) isolates were characterized. The novel BSMYV genetic variants were associated with conspicuous necrosis on newly emerged leaves, peduncle distortion, pseudostem internal necrosis, in addition to common streak symptoms. For complete genome nucleotide sequences, BSMYV-IN4 and IN5 shared 77-79% identity with other BSMYVs, while BSMYV-IN7 and IN8 exhibited identities of 77-97%. This study reports for the first time, the complete genomes of two banana streak IM virus (BSIMV-IN1 and -IN2) infecting triploid banana hybrids exhibiting leaf distortion, stunted rosette-like growth, and necrosis, sharing 87% sequence identity with reference BSIMV genome (GenBank accession no. HQ593112). Phylogenetic inference based on complete genomes revealed the distinct and congruent placement of BSMYV-IN4 and IN5 within the BSMYV cluster. Pairwise sequence comparisons of the conserved RT/RNase H nucleotide (nt) sequences revealed that the BSMYV-IN7 and IN4 isolates showed 85% and 97% identity to BSMYV (AY805074), respectively, which shared highest nt identity with BSMYV-IN6, IN9, and IN10, at 100%. The RT/RNase H nt sequences of BSIMV-IN1 and IN2 had 98% identity with the BSIMV (HQ593112), but were characterized as novel variants of BSIMV based on complete genomes. An analysis of relative synonymous codon usage (RSCU) pattern in the ORFIII polyprotein of BSMYV and BSIMV isolates revealed AGA and AGG (arginine) as the most frequently overrepresented codons (>1.5), evolutionary conserved in the genome of both species. A total of 14 recombination events were detected among the 36 BSV genomes, with recombination breakpoints mainly located in the ORFI, III, and IGR genomic regions. A novel phylogenetic cluster, comprised of BSMYV-IN4 and IN5 within the clade I was probably derived from heterologous recombination between parents resembling banana streak VN virus (BSVNV; AY750155) and banana streak GF virus (BSGFV; KJ013507) isolates. The present study conclusively reports the infection of genetically and symptomatically distinct variants of BSMYV and BSIMV infecting banana hybrids in NER India.

Seismic aberrancy unraveling basement flexures: A study from northeast India

The basement in the Upper Assam foreland basin, northeast India, is severely deformed and buckled. It is compartmentalized into several structural compartments. These compartments are breached with minute flexures (or fractures), which developed over the geologic period due to tectonic modifications by fault networks and overlying sediment loads. Flexure anomalies dominant within the basement interval are interpreted using high-quality 3D seismic data acquired from the basin. The data are spectral balanced and structurally conditioned to improve the visibility of suppressed and masked reflections. Attribute maps obtained by computing legacy seismic attributes like energy ratio-similarity and curvature are integrated to interpret flexure networks and associated deformed structures. An advanced seismic attribute called aberrancy is computed to complement the interpretations of the preceding legacy attributes. The aberrancy attribute prominently revealed the presence of flexure networks occurring within the basement interval in the study area. In addition, the geometric characteristics of flexure anomalies suggest that flexures are particularly intense in the northeastern (zone 1) and western (zone 2) parts of the basement. The intensity of the flexures within these zones varies between 0.3 and 0.6 m−1. Overall, the basement displays a low to moderate variation in the intensity of the flexures, with exceptions observed in the aforementioned zones. The method thus presented could be applied to similar tectonic settings to aid the interpretation of subtle deformed networks observed in seismic data.

Factors influencing delayed cancer health seeking in Meghalaya, Northeast India: A qualitative study

Background & objectives India accounts for about seven per cent of the global cancer burden with the highest cancer incidence reported from the North-Eastern Region (NER), including Meghalaya. Despite this, there is paucity of published studies on health seeking behaviour for cancer in the NER. To address this gap, this study used a qualitative approach to document patient, caregiver and provider perspectives to understand the factors influencing healthcare seeking for cancers in Meghalaya. Methods In-depth interviews were undertaken with 37 individuals diagnosed with one of the top five cancers in Meghalaya, namely, oesophageal, breast, oral, cervical and lung cancer. They were identified from the State referral cancer hospital. Twelve caregivers and five healthcare providers were also interviewed. All interviews were conducted in the local language using semi-structured interview guides. Transcripts were translated to English, coded, categorized and analyzed using thematic framework content analysis approach. Results A key factor influencing delayed cancer treatment in Meghalaya included misconceptions regarding the causes of cancer and cultural concepts such as bih and skai (Khasi language), i.e. notions of a figurative ‘poison’ or ill intent that makes one susceptible to illness. A general reluctance to discuss cancer diagnoses, perceived stigma, apprehension of treatment methods influenced their decision. Other factors included negligence and misinterpretation of early symptoms of cancer, self-management, preference for traditional medicines, financial constraints and health system-related factors. Interpretation & conclusions This study underscores the importance of addressing barriers to cancer diagnosis and treatment in indigenous populations in northeast India, advocating for culturally appropriate messaging, capacity building for healthcare workers, integration of traditional healers, and community involvement to enhance early healthcare seeking and improve outcomes.

An Outbreak of Acute Hemorrhagic Conjunctivitis Caused by Coxsackievirus A24 in Eastern Uttar Pradesh, India 2023

Introduction: Acute hemorrhagic conjunctivitis (AHC) outbreaks are caused mostly by viruses. During July-August 2023, there was a sudden spike in acute hemorrhage conjunctivitis cases in Eastern Uttar Pradesh, India. To identify the etiological and gain molecular epidemiology of the agent, the study was conducted. Methodology: Conjunctival swabs were collected from patients (n = 128) with presumed acute hemorrhage conjunctivitis visiting two tertiary care hospitals. Results: Enteroviruses infection was identified in 96 (75%) patients. In these patients, coxsackievirus A24 (CV-A24) infection was further confirmed by targeting the genetic regions of 3C protease and VP1. Furthermore, the study established the outbreak was caused by the genotype IV of CV-A24 with the highest genetic similarity with CV-A24 reported from Northeast India, China, and Pakistan circulating during the same period. The comparison of our study sequences with earlier Indian outbreak strains (2007) revealed four amino acid substitutions at the 3C region (“S21N,” “V30I,” “S66I,” and “V75I”) and three non-synonymous mutations at the VP1 region (“L16I,” “P21S,” and “N301D”). Conclusion: The study findings revealed that the AHC outbreak was caused by genotype IV of CV-A24 in this region. Molecular identification accompanied by phylogenetic analysis will be useful in studying the enterovirus epidemiology associated with AHC outbreaks.

Surveillance of Food and Waterborne Pathogens in North-East India: Protocol for a Laboratory-Based Sentinel Surveillance Study.

Food safety is a global concern, which is often underestimated owing to challenges in investigating foodborne diseases. These challenges arise from the increased globalization of the food trade, advancements in agricultural practices, and shifts in environmental factors. In North-East India, common diarrheal outbreaks from fermented foods pose significant health risks. Despite these challenges, systematic data on foodborne pathogens is lacking in India, highlighting a crucial gap in understanding food safety issues. The aim of this research protocol is to establish an integrated surveillance system to identify enteric pathogens circulating within humans, food animals, and the environment through a health approach in North-East India, and to conduct outbreak investigations. The Indian Council of Medical Research (ICMR) initiated a surveillance study across all 8 North-East states in India, employing a centralized digital database for data collation. The project aims to enhance theinfrastructure for microbial culture, antibiotic sensitivity testing, and molecular epidemiological studies. The study involves laboratory-based surveillance of foodborne pathogens in market foods, hospitalized diarrheal patients, poultry and animal farms, slaughterhouses, butcher shops, and diarrheal outbreaks. A standardized case report form ensures consistent data collection of age, sex, signs, symptoms, and admission dates for diarrheal cases. Stool and rectal swabs will undergo testing for pathogen identification and antimicrobial resistance. Similarly, samples of market foods, food animals, and the environment will be collected. Outbreaks confirmed by the Integrated Disease Surveillance Project (IDSP) will be thoroughly investigated following standardized guidelines. In phase I, 5 surveillance centers were established across 4 states (ie, Assam [Dibrugarh and Guwahati], Tripura, Sikkim, and Arunachal Pradesh) in 2020. Following an interim phase I data assessment and the successful establishment of a streamlined system for data procurement, investigation, recording, and analysis, along with the implementation of regular training and monitoring programs, phase II expansion was initiated in 2023-24. This includes the addition of 7 more centers (including 3 veterinary centers) in the remaining 4 states (ie, Manipur, Meghalaya, Mizoram, and Nagaland), eventually covering the entire North-Eastern Region of India. Food and waterborne diseases are a constant public health problem in many countries. Key challenges to the enhancement of food safety policy include the paucity of systematic data and awareness. With this background, ICMR's initiative is the first systematic surveillance study in the country to adopt a single health approach. Data obtained from this project will help to understand the risk of acquiring food and waterborne pathogens, their transmission pathways, and antimicrobial resistance patterns. The scientific evidence generated through this project will be helpful in formulating and strengthening food safety policy and in initiating government programs to protect the health of the nation. DERR1-10.2196/56469.

Molecular characterization of human adenovirus associated with pediatric severe acute respiratory infections in a tertiary care hospital in North East India

PurposeThe present study explored the molecular characterization of human Adenovirus (HAdV) and its strains among hospitalized SARI cases in the pediatric unit of a tertiary care hospital in North-East India.MethodsNasal and throat swabs were collected from 70 patients of Pediatric Unit, of a tertiary hospital in NE India from April 2023-October 2023. The samples were screened for the presence of HAdV using an adenovirus-specific Real-Time PCR Kit. For molecular characterization, Next Generation Sequencing (NGS) was performed by targeting the hexon gene of HAdV followed by post-sequencing analysis.ResultsOverall, 18.57% (13/70) of samples were positive for HAdV. In context of the severity of illness, 3/13 adenovirus-positive patients (23.07%) died after hospitalization, had severe pneumonia among which two were of less than one year of age. Molecular characterization using NGS indicated that 4/13 individuals were infected with HAdV-B type 3 and 5/13 patients were infected with HAdV type 7. Notably, 4/7 cases of severe pneumonia were under five years of age and associated with HAdV type 7 infection. The ratio of non-synonymous to synonymous mutation (dN/dS) was comparatively low in HAdV type 7 positive samples (dN/dS=0.31). No non-synonymous mutation was observed in HAdV-B type 3 positive samples. The higher neutrophil percentage among the death cases suggested an acute immune response.ConclusionThe study demonstrated HAdV type 7 and HAdV-B type 3 as strains associated with pediatric SARI cases from April 2023-October 2023. Further, HAdV type 7 infection was primarily linked with lower respiratory tract infections mainly severe pneumonia.

A shallow mantle seismic discontinuity beneath northeast India: Evidence from receiver function analyses

The crust and shallow upper mantle structure beneath the Upper Brahmaputra Valley, Indo-Burma Ranges, and Bengal Basin of Northeast India have been investigated based on receiver function (RF) analysis of teleseismic earthquakes recorded by 11 seismological stations. The study reveals a thin crust (∼35 km) beneath the Brahmaputra Valley (at JORH station) with a surface sedimentary layer of ∼4 km thick. The crustal thickness is observed to increase towards the north in the Himalaya (∼40 km at ZIRO and ITAN) and to the south (up to ∼46 km at KOHI). The crustal thickness near the Tripura fold-belt and Bengal Basin varies within ∼36–40 km. The study reveals the existence of a shallow mantle discontinuity (Hales discontinuity) at a variable depth range of ∼54–78 km characterized by a step increase (∼7.5–11 %) in shear wave velocity observed in the inverted models. The mineralogical phase transformation from spinel to garnet is considered as the origin of this discontinuity. The shallow depth of the discontinuity indicates an increase in upper mantle temperature which conforms to the high geothermal gradient reported in the region. The variation of depth of the discontinuity can be interpreted in terms of the addition of Cr+3 that shifts the spinel-garnet stability field to higher depths whereas Fe+2 shifts it to lower depths. Despite the high temperature in the upper mantle, the observed low Vp/Vs ratio (1.65–1.75) below the Hales discontinuity can be explained by the presence of a high fraction of orthopyroxene.

Report of Epicoccum sorghinum causing leaf spot on Phaseolus vulgaris in North-East India

Report of Epicoccum sorghinum causing leaf spot on Phaseolus vulgaris in North-East India

Reevaluating the impact of intimate partner violence on reproductive health with a critical examination of underlying factors in Northeast India.

Reevaluating the impact of intimate partner violence on reproductive health with a critical examination of underlying factors in Northeast India.