Stream Types Research Articles

Influence of Physiographic Region on Pathogen Concentrations Between Stream Types

Predicting public health risk associated with exposure to and recreational use of surface waters is often challenging due to substantial variability in concentrations of pathogenic bacteria, even among seemingly similar streams. In this study, we document significant differences in the surface water concentrations of the common bacteria indicators Escherichia coli and fecal coliform between two major stream types—blackwater and redwater streams (p < 0.001). We propose and present evidence that these findings result from natural biogeochemical variation between physiographic regions (p < 0.001). These findings suggest that physiographic stream type may influence the degree of exposure to waterborne pathogens and risk of waterborne disease. Future research is needed to assess whether the inclusion of stream type in risk assessments can improve public health modeling and mapping.

Quantifying Streambed Grain Size, Uncertainty, and Hydrobiogeochemical Parameters Using Machine Learning Model YOLO

AbstractStreambed grain sizes control river hydro‐biogeochemical (HBGC) processes and functions. However, measuring their quantities, distributions, and uncertainties is challenging due to the diversity and heterogeneity of natural streams. This work presents a photo‐driven, artificial intelligence (AI)‐enabled, and theory‐based workflow for extracting the quantities, distributions, and uncertainties of streambed grain sizes from photos. Specifically, we first trained You Only Look Once, an object detection AI, using 11,977 grain labels from 36 photos collected from nine different stream environments. We demonstrated its accuracy with a coefficient of determination of 0.98, a Nash–Sutcliffe efficiency of 0.98, and a mean absolute relative error of 6.65% in predicting the median grain size of 20 ground‐truth photos representing nine typical stream environments. The AI is then used to extract the grain size distributions and determine their characteristic grain sizes, including the 10th, 50th, 60th, and 84th percentiles, for 1,999 photos taken at 66 sites within a watershed in the Northwest US. The results indicate that the 10th, median, 60th, and 84th percentiles of the grain sizes follow log‐normal distributions, with most likely values of 2.49, 6.62, 7.68, and 10.78 cm, respectively. The average uncertainties associated with these values are 9.70%, 7.33%, 9.27%, and 11.11%, respectively. These data allow for the computation of the quantities, distributions, and uncertainties of streambed HBGC parameters, including Manning's coefficient, Darcy‐Weisbach friction factor, top layer interstitial velocity magnitude, and nitrate uptake velocity. Additionally, major sources of uncertainty in grain sizes and their impact on HBGC parameters are examined.

Responses of diatoms and aquatic macroinvertebrates to deposited fine sediment in mesocosm channels as a basis for a new water quality guideline

Water quality guidelines are an important tool for managing environmental pressures on freshwater streams. Currently, there is a lack of guideline values for fine sediment deposition in South Australian and, more broadly, Australian and overseas streams despite the potentially profound impacts of sediment deposition on aquatic communities. We used an outdoor recirculating stream mesocosm to assess the responses of freshwater diatoms and macroinvertebrates to fine sediment burial after six weeks following a pulsed event. Communities were exposed to five treatments of fine sediment deposition (inert sand) with an average depth between 1 and 20 mm, added on top of, and compared to, representative background sediments from a high-quality stream dominated by hard-bottom sediments and detritus. The most pronounced change was between the control and treatment one (1 mm sediment depth). Sediment deposition negatively affected diatom composition, with a decrease in functional diversity but a concurrent increase in taxonomic diversity arising from increased abundances of motile species. For macroinvertebrates, there was a clear negative response in the richness and abundance of the sensitive Ephemeroptera, Plecoptera and Trichoptera insect orders to fine sediment burial, and an associated higher macroinvertebrate drift propensity. This study highlights the importance of incorporating functional and behavioural responses in addition to taxonomic metrics when assessing biotic responses to stressors. This study recommends a new guideline which restricts additional fine sediment deposition to <1 mm in temperate South Australian freshwater streams, particularly those dominated by hard-bottom substrates and, or containing sensitive aquatic taxa. This threshold could act as an interim guideline for these stream types elsewhere in the absence of comparable studies.

Evaluating intra- and inter-life stage density-dependent dynamics for management of perennial amphidromous fish.

Compensatory density-dependent (DD) processes play an integral role in fisheries management by underpinning fundamental population demographics. However, DD processes are often assessed only for specific life stages, likely resulting in misleading evaluations of population limitations. Here, we assessed the relative roles of intra- and inter-life stage DD interactions in shaping the population dynamics of perennial freshwater fish with demographically open populations. Specifically, we monitored populations of amphidromous banded kōkopu (Galaxias fasciatus), giant kōkopu (Galaxias argenteus), and shortjaw kōkopu (Galaxias postvectis) in five streams where migratory post-larvae are fished and in three no-take ("closed") streams located on New Zealand's South Island for two years. Using mark-recapture data, we investigated whether fishing altered densities of "small" (non-territorial recruits ≤1-year-old) and "large" (territorial fish >1-year-old) kōkopu size classes, and how subsequent density shifts affected the apparent survival and growth of each class while controlling for other confounding factors (e.g., habitat characteristics). We found that closed areas had substantially greater biomass of small kōkopu, particularly following the two-month fishing season. Despite this greater influx of recruits, there was no difference in the biomass of large kōkopu at the species level, or as a combined assemblage between stream types. This indicated that although fishing of post-larvae reduced recruit influxes into adult habitats, there was no subsequent evidence of recruitment-limitation within adult populations. Instead, kōkopu demographics were underpinned by intra- and inter-life stage DD competition and predation. Greater large fish densities played a key role in regulating the survival, growth, and/or presence of various kōkopu classes. In contrast, greater small fish densities had positive effects on the growth of opportunistic and insectivorous congeners, likely due to cannibalism and altered foraging behaviors, respectively. Our study details the prominent role of intra- and inter-life stage DD interactions in regulating the population dynamics of perennial migratory freshwater fishes, even in populations with inhibited recruit and juvenile availability. We emphasize the importance for fisheries management to implement recruitment dependencies and complex interactions between distinct life stages to avoid deleterious DD responses and ensure population persistence.

A Sustainable Approach to the Comprehensive Analysis of the Nutrient Content and Phytochemical Profile of Industrial Food Waste

This research paper offers a comprehensive analysis of the nutrient content and phytochemical profile of industrial food waste, focusing on key elements including nitrogen, phosphorus, potassium, carbon, and hydrogen, as well as bioactive compounds. The study involves the characterization of various types of food waste streams to elucidate their nutritional composition and bioactive compound content. Analytical techniques such as NPK analysis, carbon and hydrogen analysis, and phytochemical qualitative analysis are employed to quantify and identify the presence of essential nutrients and bioactive compounds in the waste excrement materials. Additionally, present paper explores the potential value-added opportunities through product development using extracted bioactive compounds. Perspectives from recent research that advance knowledge of industrial food waste as a valuable resource for nutrient recovery and bioactive compound extraction, thereby fostering sustainable food waste management practices and promoting the development of value-added products for various industries.

Secondary School Teachers Perception of Using ICT in the Classroom

This study explores secondary school teachers' perceptions of using Information and Communication Technology (ICT) as an instructional tool in schools across Uttar Pradesh, focusing on variations by stream, gender, and school management type. It also examines the availability of ICT resources and challenges faced by teachers in integrating these tools. Despite significant differences in ICT facilities among school types, teachers' perceptions of ICT do not vary significantly by gender, stream, or management type. Most teachers, regardless of these factors, view ICT as highly important for education. However, challenges such as hardware issues, lack of technical support, and inadequate training hinder effective ICT use. Notably, even teachers who don't actively use ICT in classrooms still have a high perception of its value, influenced by personal use and external exposure. The study employed a mixed-method approach, analyzing data through ANOVA and Chi-square tests, and highlights the potential for fostering learner centered environments given the generally positive teacher attitudes toward ICT.

Inferences based on diatom compositions improve estimates of nutrient concentrations in streams

Nutrient concentrations in streams vary strongly with flow conditions, and routinely gathered field measurements of nutrients reflect this variability. Diatom assemblage composition has been used in previous studies to infer nutrient concentrations, and because diatoms integrate nutrient concentrations over longer periods of time, diatom inferences may be less susceptible to fluctuations in streamflow. We tested this hypothesis by leveraging differences in the flashiness of streams across a large continental data set. More specifically, we tested whether the variabilities of direct measurements and diatom inferences of dissolved phosphorus and nitrate were greater in flashy versus non-flashy streams. We further considered whether models linking landscape predictor variables to nutrient concentrations yielded consistent results across flashy and non-flashy streams. Our analysis indicated that measured nutrient concentrations were more variable in flashy compared to non-flashy streams and that landscape models identified different important predictors of nutrient concentrations when fit using data from flashy vs. non-flashy streams. In contrast, variabilities of diatom-inferred nutrient concentrations were similar among stream types, as were the important predictor variables (e.g., manure application rates for nitrate and number of wet days for dissolved phosphorus). These analyses indicate that use of diatom-inferred nutrient concentrations can potentially improve efforts to quantify stream nutrient concentrations.

The origin of interplanetary switchbacks in reconnection at chromospheric network boundaries

There is renewed interest in heliospheric physics following the recent exploration of the pristine solar wind by the Parker Solar Probe. Magnetic switchback structures are frequently observed in the inner heliosphere, but there are open questions about their origin. Many researchers are investigating the statistical properties of switchbacks and their relationships with wave modes, stream types and solar activity, but the sources of switchbacks remain elusive. Here we report that interplanetary switchbacks originate from magnetic reconnection on the Sun that occurs at chromospheric network boundaries and launch solar jet flows. We link in situ interplanetary measurements and remote-sensing solar observations to establish a connection between interplanetary switchbacks and their solar source region, featuring solar jets, chromospheric network boundaries and photospheric magnetic field evolution. Our findings suggest that joint observations of switchbacks and solar jets provide a better estimate of the contribution of magnetic reconnection to coronal heating and solar wind acceleration.

Investigating smartphone addiction among senior secondary school students

The present study is based on the smartphone addiction which is an emerging problem of the current time. Our youth is getting distracted due to excessive use of smartphones nowadays. The study aimed to find out the significant difference of smartphone addiction among senior secondary school students with respect to their gender (i.e. male and female); type of schools (i.e. government and private); streams (i.e. science, arts and commerce); type of families (i.e. joint and nuclear); and social category (i.e. general and scheduled castes). Tool used to collect the data was smartphone addiction scale developed by Dr. Vijayshri and Dr. Masaud Ansari. The sample consisted of 200 senior secondary school students, out of which 100 were males and 100 were females. Collected data was analyzed through mean, standard deviation and t-test. The results revealed that there was no significant difference in the smartphone addiction among senior secondary school students in relation to their gender (male and female), stream (i.e. science and commerce; arts and commerce), type of family (i.e. joint and nuclear), social category (general and scheduled castes). While there was a significant difference in the smartphone addiction among senior secondary school students in relation to their type of school (i.e. government and private) and stream (science and commerce). It was suggested that schools should integrate digital literacy into the curriculum which can educate students about the responsible use of smartphones highlighting potential risks of addiction.

Double-Ended Bit-Stealing for Algebraic Data Types

Algebraic data types are central to the development and evaluation of most functional programs. It is therefore important for compilers to choose compact and efficient representations of such types, in particular to achieve good memory footprints for applications. Algebraic data types are most often represented using blocks of memory where the first word is used as a so-called tag, carrying information about the constructor, and the following words are used for carrying the constructor's arguments. As an optimisation, lists are usually represented more compactly, using a technique called bit-stealing, which, in its simplest form, uses the word-alignment property of pointers to byte-addressed allocated memory to discriminate between the nil constructor (often represented as 0x1) and the cons constructor (aligned pointer to allocated pair). Because the representation supports that all values can be held uniformly in one machine word, possibly pointing to blocks of memory, type erasure is upheld. However, on today's 64-bit architectures, memory addresses (pointers) are represented using only a subset of the 64 bits available in a machine word, which leave many bits unused. In this paper, we explore the use, not only of the least-significant bits of pointers, but also of the most-significant bits, for representing algebraic data types in a full ML compiler. It turns out that, with such a particular utilisation of otherwise unused bits, which we call double-ended bit-stealing, it is possible to choose unboxed representations for a large set of data types, while still not violating the principle of uniform data-representations. Examples include Patricia trees, union-find data structures, stream data types, internal language representations for types and expressions, and mutually recursive ASTs for full language definitions. The double-ended bit-stealing technique is implemented in the MLKit compiler and speedup ranges from 0 to 26 percent on benchmarks that are influenced by the technique. For MLKit, which uses abstract data types extensively, compilation speedups of around 9 percent are achieved for compiling MLton (another Standard ML compiler) and for compiling MLKit itself.

Shaping of the risk of a series-parallel manufacturing structure maintenance according to quasi-coherence and the [formula omitted]-th survival value

The paper presents the authors’ model for determining the probability value of the survival function of the difference of two random variables: TP – the amount of time of correct operation and TB – the amount of time of failure. For this purpose, the concept of K-th survival value is introduced. The K-th survival value defines the probability that the total time of correct operation of the production system will be longer by at least k time units (for k≥0) than the total amount of time of failures. The model was exemplified by a real production system with a series–parallel structure. In the nesting manufacturing structure, the availability of machines determines the number and the type of flow streams of the processed material. To formalise the chains of relations at a given Δt, this paper utilises the quasi-coherence property. The paper identifies four possible cases of system operation: 1) a fully operational system in which every machine is capable of meeting the assumed production schedule; 2) a system which has lost the property of quasi-coherence (certain system objects are in an inoperable state) but it is possible to meet the assumed production schedule; 3) a system which has lost the property of quasi-coherence but the assumed task schedule is possible to meet after redefining the material flow streams; 4) a system which has lost the property of quasi-coherence and it is impossible to meet the assumed production schedule. Based on the definition of the survival function [1] S of the random variable T: ST:=PT>τ=1-FTτ,τ∈R, the concept of K-th survival value was introduced. For possible cases, K-th survival value was defined as: KT1,Ti=PT1-Ti≥k=1-FT1-Tik (for i=2,3,4), where T1 and Ti are random variables with given probability distributions. In turn, k is a deterministic value that determines the total number of time units of correct system operation in relation to the total failure time. The application of the developed algorithm enables the system to be analysed in terms of three aspects: (1) to determine the probability of on-time execution of tasks, taking into account historical values of machine failure and correct operation durations; (2) to determine the stability of the system based on empirical data; (3) to monitor the level of risk in real time. The paper validates the model by determining the stability of the analysed system for real machine failure data. The introduced criterion of stochastic stability of the production system has been verified for data in which distributions of correct operation times and failure times are random variables from the family of Gamma distributions. The presented model can be included in the group of multifactorial risk assessment methods.

Adaption of a traditional Māori fishing method for biomonitoring: using whakaweku for sampling benthic macroinvertebrates in streams

ABSTRACT Whakaweku are bundles of bracken fern (Pteridium esculentum) traditionally placed in lakes and rivers by Māori to harvest kōura (freshwater crayfish, Paranephrops spp.) in Aotearoa, New Zealand. Previous studies show they are effective for monitoring populations of kōura and toitoi (small eleotrid fish, Gobiomorphus spp.). We wanted to determine whether whakaweku are also effective for monitoring benthic macroinvertebrate communities in streams. We placed whakaweku in a hard-bottomed and a soft-bottomed reach of a rural stream in the Waikato, and took standard ‘kick-net’ samples from the same locations. We retrieved whakaweku after two and four weeks submerged. Whakaweku gave comparable results to kick-net sampling for common macroinvertebrate metrics (MCI, SQMCI, total richness and EPT* richness). Macroinvertebrate community composition was significantly different between the two methods, but most taxa were common to both. Macroinvertebrate metrics did not change significantly between two-week and four-week colonisation periods. A wider study would show whether whakaweku can distinguish between sites over a gradient of human impact. We recommend whakaweku in Māori cultural and community stream monitoring as it is inexpensive, simple to use, captures many macroinvertebrate taxa used in biomonitoring, works in different stream types and can be used to monitor kōura, toitoi and macroinvertebrates simultaneously.

Is the ordinary high water mark ordinarily at bankfull? Applying a weight‐of‐evidence approach to stream delineation

AbstractThe ordinary high water mark (OHWM) is a regulatory boundary essential to identifying the lateral jurisdictional limits of rivers and streams in the United States (U.S.). Bankfull is a scientific concept that has been defined and identified in a multitude of ways by scientists. Geomorphologist and hydrologist have long recognized that there can be variability in the identification of bankfull depending on how bankfull is defined. Furthermore, this variability is only increased by the inherent variability in stream characteristics that occurs along a reach of channel. Because of the overlap in the regulatory definition of OHWM and the scientific definitions of bankfull, one of the primary purposes of the study is to apply the definition of OHWM and compare it to bankfull in a variety of channel types in different climatic, hydrologic, and geologic settings. Our results show that there is a clear overlap between the identification of the OHWM and bankfull elevations. Regulatory practitioners are generally not specialized in fluvial geomorphology and yet are tasked with consistently and accurately identifying the OHWM in a variety of stream types throughout the U.S. Therefore, we also present how to apply a weight‐of‐evidence approach through a clear step‐by‐step process to potentially improve consistency and accuracy in identification of OHWM and bankfull by both scientists and non‐scientists.

RDF Stream Taxonomy: Systematizing RDF Stream Types in Research and Practice

Over the years, RDF streaming has been explored in research and practice from many angles, resulting in a wide range of RDF stream definitions. This variety presents a major challenge in discussing and integrating streaming systems due to a lack of a common language. This work attempts to address this critical research gap by systematizing RDF stream types present in the literature in a novel taxonomy. The proposed RDF Stream Taxonomy (RDF-STaX) is embodied in an OWL 2 DL ontology that follows the FAIR principles, making it readily applicable in practice. Extensive documentation and additional resources are provided to foster the adoption of the ontology. Three use cases for the ontology are presented with accompanying competency questions, demonstrating the usefulness of the resource. Additionally, this work introduces a novel nanopublications dataset, which serves as a collaborative, living state-of-the-art review of RDF streaming. The results of a multifaceted evaluation of the resource are presented, testing its logical validity, use case coverage, and adherence to the community’s best practices, while also comparing it to other works. RDF-STaX is expected to help drive innovation in RDF streaming by fostering scientific discussion, cooperation, and tool interoperability.

How Live Marketing Affects Green Purchase in the Age of Artificial Intelligence?

ABSTRACT With the rise of artificial intelligence and the public’s attention to environmental issues, live online promotion of green products has become a new marketing method. It has become a key issue for enterprises to choose the appropriate information framework to motivate consumers’ green purchasing behavior through different forms of live broadcasting. Combined with laboratory experiments, this study analyses the interaction between the type of live streaming and message framing on green purchase intention based on explanation level theory. Three experiments results show that using loss-framing message real anchors are more likely to promote consumers’ green purchase intentions, and AI anchors are more suitable for using gain frames. Besides, consumer innovativeness moderates the influence of message framing and live streaming form on green purchase intention, and green perceived value plays a mediating role in this process. Our findings can not only guide the formulation of enterprise marketing strategy, but also provide countermeasures and suggestions for the future development of live marketing.

Detecting mining impacts on freshwater ecosystems using replicated sampling before and after the impact

Detecting human impact on freshwater ecosystems is problematic without rigorous assessment of temporal changes. Assessments of mining impacts are further complicated by the strong influence of local catchment geology on surface waters even in unmined environments. Such influence cannot be effectively considered by using broad-scale reference frameworks based on regionalization and stream types. Using the BACI (Before-After Control-Impact) design, we examined the impact of mining discharges on freshwater algae and macroinvertebrate communities resulting from the rerouting of treated wastewaters through a pipeline to larger water bodies in Northern and North-Eastern Finland. Impacted sites and control sites were sampled 1 to 2 years before and 1 to 3 years after the pipelines became operational. Stream diatom communities recovered from past loadings upstream of the pipeline (which was no longer impacted by wastewaters) after rerouting of the wastewaters, while no changes downstream from the pipeline were detected. Upstream from the pipeline, diatom species richness increased and changes in relative abundances of the most common diatom taxa as well as in the overall community composition were observed. The effects of the pipeline were less evident for stream macroinvertebrate communities. There was an indication that regional reference conditions used in national biomonitoring may not represent diatom communities in areas with a strong geochemical background influence. Lake profundal macroinvertebrate communities were impacted by past loadings before the construction of the pipeline, and the influence of the pipeline was observed only as changes in the abundances of a few individual species such as phantom midges (which increased in abundance in response to discharges directed through the pipeline). Our results highlight the variable influence of mining discharges on aquatic communities. Statistically strong monitoring programmes, such as BACI designs, are clearly needed to detect these influences.

Stream Types

Stream Types

Ecological “Windows of opportunity” influence biofilm prokaryotic diversity differently in glacial and non-glacial Alpine streams

In glacier-fed streams, the Windows of Opportunity (WOs) are periods of mild environmental conditions supporting the seasonal development of benthic microorganisms. WOs have been defined based on changes in biofilm biomass, but the responses of microbial diversity to WOs in Alpine streams have been overlooked. A two year (2017–2018) metabarcoding of epilithic and epipsammic biofilm prokaryotes was conducted in Alpine streams fed by glaciers (kryal), rock glaciers (rock glacial), or groundwater/precipitation (krenal) in two catchments of the Central-Eastern European Alps (Italy), aiming at testing the hypothesis that: 1) environmental WOs enhance not only the biomass but also the α-diversity of the prokaryotic biofilm in all stream types, 2) diversity and phenology of prokaryotic biofilm are mainly influenced by the physical habitat in glacial streams, and by water chemistry in the other two stream types. The study confirmed kryal and krenal streams as endmembers of epilithic and sediment prokaryotic α- and β-diversity, with rock glacial streams sharing a large proportion of taxa with the two other stream types. Alpha-diversity appeared to respond to ecological WOs, but, contrary to expectations, seasonality was less pronounced in the turbid kryal than in the clear streams. This was attributed to the small size of the glaciers feeding the studied kryal streams, whose discharge dynamics were those typical of the late phase of deglaciation. Prokaryotic α-diversity of non-glacial streams tended to be higher in early summer than in early autumn. Our findings, while confirming that high altitude streams are heavily threatened by climate change, underscore the still neglected role of rock glacier runoffs as climate refugia for the most stenothermic benthic aquatic microorganism. This advocates the need to define and test strategies for protecting these ecosystems for preserving, restoring, and connecting cold Alpine aquatic biodiversity in the context of the progressing global warming.

Discourse analysis of knowledge-based live streaming: a case study of East Buy streamer Dong Yuhui

Abstract Live streaming e-commerce is not only an important part of China’s digital economy but also the preferred way of purchase for many Chinese, especially the young. Since 2022, a new model initiated by East Buy has emerged, quickly becoming known as knowledge-based live streaming. The most famous streamer from this novel type of live streaming is Dong Yuhui, a former English teacher of the New Oriental School. As a top Internet influencer with millions of followers, Dong Yuhui has become a conspicuous social sign of the rising China that is undergoing fast technological, economic, and cultural changes. This study thus takes Dong Yuhui as an example to examine the typical discourses of the knowledge-based live streaming. Through a triangulation of case study, discourse analysis, and sentiment analysis, it finds that Dong Yuhui mainly employs the strategies of disseminating encyclopedic knowledge, telling intriguing stories, and using poetic language in his live streaming discourse. This unique discourse has the main function of fulfilling customers’ intellectual, emotional, and psychological needs. As such, it is warmly received by customers, whose comments are centered on the talents of the streamer rather than the attributes of the commodity.

How Celebrity Endorsement Affects Travel Intention: Evidence From Tourism Live Streaming

Celebrity endorsements via live streaming continue to draw attention in the tourism industry. This research examines the effects of such endorsements on tourism live streaming. We specifically compared celebrity streamers to key opinion leader streamers and brand streamers across two types of live streaming (travel live streaming vs. tourism e-commerce live streaming). Drawing on the flow theory, we developed a theoretical framework to explain why and how celebrity streamers can inspire travel intention more effectively than key opinion leader streamers and brand streamers. Results indicate that celebrity streamers’ endorsements enhance travel intention via informativity, entertainment, and interactivity, compared with endorsements from key opinion leaders and brand streamers. This effect is further amplified during travel live streaming.