1,721,011 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Reproductive environment of the decreasing Indian river shad in Asian inland waters: disentangling the climate change and indiscriminative fishing threats
No full textNot AvailableThe regional climate has significantly warmed with erratically declining annual rainfall and intensified downpour within a narrower span of monsoon months, which led to an increased trophic state (algae) in most inland waters. Freshwater clupeids vitally control the aquatic food chain by grazing on algae. Despite increasing food availability, IUCN Red List revealed 16 freshwater clupeids with a decreasing population trend. We investigated one such species reproductive dependencies, Gudusia chapra (Indian river shad), in the lower Gangetic drainage (India) under a mixed context of climate change and overfishing. Monthly rainfall ( 60100 mm) and water temperature ( 3132 C) are key breeding cues for females. The regional climate seems inclined to fulfill these through the significant part of the breeding season, and indeed the species has maintained consistent breeding phenology over 20 years. Other breeding thresholds relevant to fishing include size at first maturity ( 6.8 cm; reduced by ~ 2536%) and pre-spawning girth (Girthspawn50 7 cm; first record). Girthspawn50 is a proxy of the minimum mesh size requirement of fishing nets to allow safe passage of gravid females ( + 22% bulged abdomen) and breed. The operational fishing nets (310 cm mesh) probably have been indulged in indiscriminative fishing of gravid females for generations. Under a favorably changing climate and food availability, existing evidence suggests a fishery-induced evolution in regional females (to circumvent such mesh sizes) through earlier maturation/puberty at smaller sizes. It could be an early warning sign of population collapse (smaller females lessening fecundity fewer offspring). Overfishing seemed to be a bigger threat than climate change
Inland waterways transport freight data
No full textThe IWT freight data was used as a proxy for the intensity of inland navigational use. Contemplating relative country-specific prospective impact comparison, yearly time series IWT freight data during (2001 - 2021) was collated from different secondary sources. The main source was International Transport Forum (ITF, 2023) who maintains the time series IWT freight data for the United Nation. However, it contained unreported or misreported data for some countries, and those were rectified from the country-specific website or the published report. The countries having data for less than 10 years were not included, except Sweden
Mobile electrophoresis kit for high school students: Scientific practices with innovation
No full textNot AvailableGel electrophoresis (GE) is the most preferred and adapted technique for the separation and identification of biological molecules like proteins/peptides and nucleic acids from diverse types of organisms. All over the world, researchers, educators, and students aspiring to work in biochemistry and molecular biology disciplines use the polyacrylamide gel electrophoresis (PAGE) technique for resolving proteins/nucleic acids for understanding the structure and function of any cell. A simple PAGE technique requires a wide range of chemicals/reagents along with a well-equipped and well-spaced laboratory. We have developed a compact and impeccable mobile electrophoresis kit suitable for any vertically oriented PAGE technique. This comprehensive and portable laboratory set-up provides the complete advantages of safety, cost-efficiency, space management, and utility to the researchers for high-throughput research. All new equipment of the mobile electrophoresis kit is fabricated using inexpensive and off-the-rack components. Overall performance of the mobile kit was verified through a practical exercises executed by high school students with positive outcomes
Assessing vulnerability of freshwater minnows in the Gangetic floodplains of India for conservation and management: Anthropogenic or climatic change risk?
No full textNot AvailableMinnows are the most ignored yet indispensable group of freshwater fishes in Asian inland waters. The reproductive resilience of minnows facing climatic variability, using a wetland inhabiting species Amblypharyngodon mola (Mola carplets) in lower Indo-Gangetic floodplains, was validated. Results revealed that spawning decision in females (threshold gonadosomatic index 5 units) is neither cued by water temperature nor rainfall. They can maintain pre-spawning fitness (condition factor 1.121.25 units) within a broad temperature (2233 C) and rainfall (0800 mm) window by active feeding, thus no risk of skipped spawning decisions while facing future climatic variabilities. Present breeding phenology (May-December) might have prolonged in the recent decade, especially the tail-end, concomitant with increasingly hot and rainy monsoon (May-August) and warmer post-monsoon months (September-December). Minnows are expected to prosper in a future climatic scenario, contributing to ecosystem balance (algal grazers) and regional food security. Female first maturity ( puberty) was encountered at 4.75.1 cm total length, hinting at a probable increase in the recent decade. Climate-favored prolonged recruitment window, in absence of extreme fishing pressure (currently), might have led to such pattern. However, this state might be temporary and labile. Minnows may soon get altered to earlier puberty (=warning sign of stock collapse) if fishing pressure intensifies under a reproductively favoring climate progression. Threshold body girth for spawning females was estimated at 3.23.4 cm ( + 17% than non-breeding ones). Fishing nets having mesh sizes (=total circumference) at least > 3234 mm will most likely be the key to minnows endurance or survival in the coming decades
Modeling pre-spawning fitness and optimal climate of spotted snakehead Channa punctata (Bloch, 1793) from a Gangetic floodplain wetland of West Bengal, India
No full textNot AvailableThe spawning and well-being of fish in an ecosystem are closely linked to climatic cues, viz., temperature and rainfall. Reduced fitness can affect the reproductive performance and lead to skipped spawning. Benchmarking the threshold fitness required for a fish population to achieve readiness for spawning, and understanding how climatic parameters influence the fitness will aid in predicting the fate of its reproductive success in future climatic conditions. This study determined the threshold condition factor pre-spawning fitness (Kspawn50) at which 50% of the female Channa punctata population can be deemed fit for spawning. The optimal climate within which pre-spawning fitness is attained by this species under Indian climatic conditions was also identified. The study was conducted from June 2015 to September 2016, covering two spawning seasons (June?August) in a Gangetic floodplain wetland of West Bengal, India. The non-parametric Kaplan?Meier method (survival fit) was used for estimation of pre-spawning fitness. ?Ready to spawn? females were classified based on binary coding of the gonadal maturity stages. The thermal and precipitation range within which spawning fitness is achieved was identified by using the locally weighted?smoothing technique. Female C. punctata pre-spawning fitness (Kspawn50) ranged from 1.26 to 1.39 with an estimated median of 1.29 units. Temperatures between 29 and 32?degree Celsius and rainfall above 100?mm were conducive to attaining the requisite pre-spawning fitness in C. punctata. This is the first study benchmarking the pre-spawning fitness and optimal climate for C. punctata. Understanding spawning requirements can inform the climate change induced impacts on reproductive plasticity and evolutionary adaptations of snakeheads in the Ganga river basin
Assessing vulnerability of wetland fisheries to climate change: a stakeholders? perception-based approach
No full textNot AvailableFloodplain wetlands are among the most threatened ecosystems. It is highly vulnerable to climate change, affecting the wetland ecosystem and its associated fisheries. In the face of data deficiency, this article presents an alternative approach to assess the vulnerability of wetland fisheries to climate change. A total of 15 wetlands from a wetland-fisheries-rich area of West Bengal, India, were selected to illustrate the methodology. The proposed method mainly relies on stakeholders? perceptions of the wetland fisheries vulnerability. Elicitation stakeholders? response iteratively screened the indicators of fisheries vulnerability. The hybrid method of index-based vulnerability comprises two types of indicators: climate indicators with long-term quantitative data and stakeholder perceived vulnerability indicators specific to wetland fisheries. The high level of consensus (92%) among respondents provided strong evidence of climate change in last 15 years, which has also been validated through long-term data analysis. The Principal Component Analysis extracted five synthesized vulnerability indicators, explaining 83.35% variability of the original 14 indicators. The wetlands were further grouped according to differential vulnerability for prioritizing the wetlands for strategic planning. Climate change, reduction in species richness and adaptive capacity were the key components responsible for differential vulnerability. The study also revealed some indigenous climate-smart mitigation strategies of wetland fisheries to climate change
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