A preliminary genealogical investigation of all the known ancestors from the year 1608 of 4 apparently unrelated French Canadian kindreds with Friedreich's ataxia reveals that the original ataxia ...gene in the province of Quebec was present within a core of no more than 10 families living in Quebec City in the mid-1600's.
A rapid epifluorescence staining method using the LIVE/DEAD
® Bacterial Viability Kit (
BacLight™) was applied to estimate both viable and total counts of bacteria in drinking water.
BacLight is ...composed of two nucleic acid-binding stains: SYTO 9™ and propidium iodide. SYTO 9™ penetrates all bacterial membranes and stains the cells green, while propidium iodide only penetrates cells with damaged membranes, and the combination of the two stains produces red fluorescing cells. Optimal incubation conditions were found to be 15 to 20 min, at room temperature in the dark. Total (red+green) and viable (green) cells can hence be counted simultaneously. Factors affecting the staining procedure were tested (addition of glutaraldehyde, staining time, chlorine impact). In the absence of stress,
BacLight viable counts were comparable and to 5-cyano-2,3-ditolyl tetrazolium (CTC) counts.
BacLight total counts were comparable to acridine orange counts (differing by <0.1 log/ml). However, the increase in environmental stresses (chlorine, growth rate or temperature) induced a decrease in viability that was more pronounced for CTC and plate counts than for
BacLight viable counts.
Spores from aerobic bacteria were evaluated as an indicator of the efficiency of chlorination. Several inactivation experiments were performed. The influence of temperature and water type was ...evaluated. Resistance of spores to chlorination was higher compared with
Giardia using the values given in the surface water treatment rule. Resistance was observed to increase with temperature. Both Chick–Watson and Hom models were found to well describe the inactivation of spores by chlorine.
This paper describes work in progress towards the elaboration of a Product Line practices model that combines concepts proposed by various authors. The strengths of existing Product Line frameworks ...and models are summarized and a new model is proposed in the form of 31 Product Line practice areas, grouped in five categories. An important objective of this Product Line practices model is that it should be easily incorporated into existing development methodologies, while remaining aligned with existing systems engineering standards.
In this paper, we present a multimodal dataset obtained from a honey bee colony in Montréal, Quebec, Canada, spanning the years of 2021 to 2022. This apiary comprised 10 beehives, with microphones ...recording more than 2000 hours of high quality raw audio, and also sensors capturing temperature, and humidity. Periodic hive inspections involved monitoring colony honey bee population changes, assessing queen-related conditions, and documenting overall hive health. Additionally, health metrics, such as Varroa mite infestation rates and winter mortality assessments were recorded, offering valuable insights into factors affecting hive health status and resilience. In this study, we first outline the data collection process, sensor data description, and dataset structure. Furthermore, we demonstrate a practical application of this dataset by extracting various features from the raw audio to predict colony population using the number of frames of bees as a proxy.
We present a longitudinal multi-sensor dataset collected from honey bee colonies (Apis mellifera) with rich phenotypic measurements. Data were continuously collected between May-2020 and April-2021 ...from 53 hives located at two apiaries in Québec, Canada. The sensor data included audio features, temperature, and relative humidity. The phenotypic measurements contained beehive population, number of brood cells (eggs, larva and pupa), Varroa destructor infestation levels, defensive and hygienic behaviors, honey yield, and winter mortality. Our study is amongst the first to provide a wide variety of phenotypic trait measurements annotated by apicultural science experts, which facilitate a broader scope of analysis. We first summarize the data collection procedure, sensor data pre-processing steps, and data composition. We then provide an overview of the phenotypic data distribution as well as a visualization of the sensor data patterns. Lastly, we showcase several hive monitoring applications based on sensor data analysis and machine learning, such as winter mortality prediction, hive population estimation, and the presence of an active and laying queen.
Winter mortality is one of the main causes of beehive loss. However, very limited tools can be used by beekeepers to identify the high-risk colonies at an early stage. In this study, we propose a ...multi-modal sensor (audio, humidity, temperature) based system to predict the beehive winter survivability. More specifically, we first propose a multi-modal feature set, which is shown to be highly correlated with winter survival rate, and develop a machine learning model to further detect the hives that are less likely to survive the winter. Our top-performing model achieves an AUC-ROC score of 0.730 based on one-year-long data collected from 45 hives located in two different apiaries in Canada. Our findings show the feasibility of capturing high-risk hives at the early stage using multi-modal sensor data. Furthermore, we highlight the importance of bee audio in measuring survivability over other more widely-used modalities. Future study will focus on improving the generalizability of the prediction model.
The decline in honey bee populations and the labor-intensive nature of manual hive inspection have sparked interest in automating beehive monitoring. Acoustic monitoring has emerged as a versatile ...modality for this purpose. Beehive audio has proven useful in detecting events such as swarming, queen absence, parasite infestation, and assessing hive strength. However, external factors such as rain, wind, traffic noise, and background voices of beekeepers can degrade the quality of recorded bee audio and impact the effectiveness of beehive monitoring. In this study, we focus on the detection of background beekeepers speech, which has shown to significantly degrade audio-based hive monitoring performance. In particular, we propose the use of universal audio representations extracted from self-supervised models to predict whether a given audio frame contains speech or only bee sounds. Experimental results on the NU-Hive dataset show that the proposed methodology applied on top of the WavLM Base+ model can outperform state-of-the-art voice activity detectors by a relative improvement of 19% and 16% in the ROC-AUC and F1-score metrics, respectively. Furthermore, we show that audio representations can be reliably used for unsupervised anomaly detection.
Reducing agents, namely sodium thiosulfate, are used to eliminate oxidant residuals in samples for biodegradable dissolved organic carbon (BDOC) analyses. For the particular BDOC assay used in this ...study, samples are seeded using a natural bacterial inoculum. These bacteria grow in response to dissolved organic carbon (DOC) and the decrease in DOC measured during the thirty day batch incubation period determines the BDOC of the sample. Na
2S
2O
3 is usually added in excess, leaving a residual thiosulfate concentration which has been found in this study to interfere with the BDOC measurement. The effect of Na
2S
2O
3 residuals between 0 and 34 mg/l on the measured value of BDOC was tested. The interference increased with the amount of Na
2S
2O
3 added and above 20 mg/l, sodium thiosulfate caused a substantial underestimation of the BDOC. The natural bacterial inoculum was indirectly found to contain bacteria capable of metabolizing thiosulfate. At concentrations above 20 mg
Na
2S
2O
3
l
, these bacteria produced sufficient acid that the heterotrophic activity necessary in the BDOC assay was effected. More tests are required to determine if the growth of these sulfur-oxidizers effects BDOC values in the absence of pH change. The use of a phosphate buffer should be considered in samples of limited buffering capacity. Given the observed effects of Na
2S
2O
3, residuals should be limited and, where possible, the use of Na
2S
2O
3 should be avoided.
Backwashing first-stage sand—BAC filters Niquette, Patrick; Prévost, Michèle; Maclean, Robert G. ...
Journal - American Water Works Association,
01/1998, Letnik:
90, Številka:
1
Journal Article
Recenzirano
The effect of filter backwash on the efficiency of first-stage sand-biological activated carbon (BAC) filters was evaluated by comparing, in first-stage sand-BAC filters, concentrations of ammonia, ...biodegradable dissolved organic carbon, aldehydes, and oxalate. These concentrations were measured before and after filter backwash. Filter position (first-stage sand-BAC filters versus second-stage BAC filters) was also studied to understand how floes and particle accumulation influenced the efficiency of the first-stage sand-BAC filter. A first-stage sand-anthracite filter operated under similar hydraulic conditions and effluent turbidity acted as a reference. Filter backwash improved the efficiency of sand-BAC filters, especially in cold water sources. However, both filters produced similar water quality. First-stage sand-anthracite filters did not adequately remove biodegradable organic matter and ammonia.
PDF
