Bed Samples Research Articles

Prevalence and molecular characterization of Cryptosporidium spp. in pre-weaned diarrheic dairy calves and their bedding materials in northern China.

Cryptosporidiosis, primarily caused by Cryptosporidium parvum, is a significant cause of diarrhea in pre-weaned dairy calves. To investigate the prevalence of Cryptosporidium among pre-weaned diarrheic dairy calves and identify potential sources of infection in northern China, 234 fecal samples from 18 farms in six regions were analyzed for Cryptosporidium. Furthermore, 217 bedding samples from both occupied and unoccupied calf hutches, heating lamp pens, and individual calving pens in eight farms in Beijing were also examined for the presence of the parasite. All samples were screened for Cryptosporidium spp. using nested PCR targeting the SSU rRNA gene fragment, and C. parvum was subtyped with nested PCR targeting the 60kDa glycoprotein gene. The prevalence of Cryptosporidium was 33.3%, with C. parvum and C. bovis constituting 29.9% and 3.4% of cases, respectively. The positive rate of Cryptosporidium in 1- to 4-week-old calves ranged from 9.6 to 63.6%. Analysis of the gp60 fragment of C. parvum revealed four subtypes: IIdA15G1, IIdA17G1, IIdA19G1, and IIdA20G1. Besides the bedding samples in heating lamp pens, both C. parvum and C. bovis were detected in bedding samples throughout the other regions. A significant positive correlation between the detection rate of Cryptosporidium in fecal samples and that in the bedding materials of occupied calf hutches (R = 0.93, P = 0.002). These findings suggest that C. parvum is the predominant species among pre-weaned diarrheic dairy calves in northern China. Contaminated bedding materials may act as sources of infection for newborn calves.

Impact of sample refrigeration and freezing on the bacteriological counts of different bedding materials for dairy cows

BackgroundDifferent organic and inorganic bedding materials can be used in dairy farms. Among organic materials, there is an increasing interest in alternative substrates based on recycled manure solids (RMS). Microbiological analyses are crucial to monitor the microbial load and evaluate the presence of pathogens impacting animal welfare and health. However, logistic factors may hamper the possibility of immediately sending fresh samples to the laboratory, requiring storage in cooled conditions before analysis.MethodsWe assessed the impact of sample refrigeration and freezing of different organic and inorganic bedding substrates including separated raw manure solids (SRMS), anaerobically digested manure solids (ADMS), and new sand (NS), on the total bacterial count (TBC) and on different microbial classes.ResultsThe TBC was higher in fresh NS and ADMS than in refrigerated and frozen samples of the same substrates; in addition, the TBC of ADMS was higher in refrigerated than frozen samples. The TBC of SRMS did not change significantly with refrigeration and freezing. Freezing reduced the total Gram-negative bacterial count more than refrigeration in all substrates. In fresh NS, Gram-negatives were higher than in both refrigerated and frozen NS. Escherichia coli counts were significantly lower in frozen than in refrigerated SRMS. However, both refrigeration and freezing of ADMS resulted in no E. coli growth. The coliform counts were also lower in frozen than refrigerated NS and SRMS. Frozen NS and ADMS showed lower counts compared to refrigeration for Gram-negative bacteria other than E. coli and coliforms. On the other hand, cold storage did not significantly impact the streptococci and streptococcus-like organisms (SSLO) count of all evaluated bedding substrates.ConclusionRefrigeration and freezing affect the bacteriological results of bedding substrates, with freezing generally leading to lower counts than refrigeration. Whenever possible, preference should be given to analyzing fresh bedding samples, however, when necessary, refrigeration would be recommended over freezing, while acknowledging that the measured bacterial load might underestimate the actual microbial content.

The polymicrobial nature of the oral cavity and claws of cats diagnosed by mass spectrometry and next-generation sequencing

Close contact between cats and humans increases the risk of transmission of zoonotic pathogens, through bites and scratches due to the complexity of microorganisms in the oral and nail microbiotas of felines. This study investigated the presence of bacteria and fungi in the oral cavity and claws of 100 apparently healthy cats using conventional and selective microbiological culture media, and next-generation sequencing (NGS) and mass spectrometry (MALDI-TOF MS). Furthermore, antimicrobial susceptibility testing of bacteria isolates was performed by disc diffusion method. In total, 671 bacteria and 33 yeasts were identified by MALDI-TOF MS. Neisseria animaloris (10.8 %), Staphylococcus felis (8.5 %), and Pasteurella multocida (7 %) were the most prevalent bacteria in oral cavity samples (n = 343), while the most common yeast (n = 19) was Candida albicans (68.4 %). Staphylococcus pettenkoferi (13.4 %), Staphylococcus felis (6.4 %), and Staphylococcus simulans (5.8 %) were the prevalent bacteria identified in the claw samples (n = 328), while Rhodotorula mucilaginosa (57.2 %) was the most common yeast (n = 14). NGS predominantly identified the genera Moraxella, Neisseria, Pasteurella, and Fusobacterium in oral cavity samples, whereas enterobacteria and staphylococci were prevalent in nail bed samples. In addition, the genera Capnocytophaga and Bartonella were identified, which have been described in serious human infections secondary to feline aggressions. Levofloxacin, marbofloxacin, and amoxicillin/clavulanic acid were the most effective drugs against the main groups of bacteria identified. Multidrug resistance was observed in 17 % of the bacterial isolates. Furthermore, three staphylococci harboring the methicillin resistance gene mecA were identified. We highlight the complexity of microorganisms inhabiting the oral/claw microbiotas of cats, the high resistance rate of the isolates to conventional antimicrobial agents, and the zoonotic risk of aggressions caused by bites and scratches from domestic cats.

Sugarcane cultivation as a major surface source of sediment in catchments from a coastal zone of Pernambuco, Brazil

ABSTRACT Identifying sediment sources is fundamental for protecting and improving soil and water quality. Conventional fingerprinting studies have often collected sediments at the overall watershed outlet only, resulting in an important spatial scale dependency. This study aimed to identify and to assess the delivery patterns of sediment sources within three priority sub-catchments (Sapocaji, Piedade and Minas) located in the downstream portion of the Ipojuca River watershed in Brazil. This research would build on understanding sediment sources in the studied watershed by elucidating source type contributions on a sub-catchment basis. Both bed and suspended sediment samples were collected in these sub-catchments, and two types of sources were sampled: surface and subsurface sources. A total of 21 geochemical tracers were measured. The tracers were evaluated for their conservation and discriminatory ability (Kruskal-Wallis test and linear discriminant analysis), and the best set of tracers was selected for source apportionment modeling using MixSIAR. Surface (i.e., sugarcane croplands) sources contributed the highest to suspended sediments in the Piedade and Minas sub-catchments. There was a difference in the quality of riverbank management, which helped explain contrasts in the importance of this source. Overall, sub-catchment-specific sediment control management measures, such as the revegetation of riparian forests, need to be implemented, mainly in the Sapocaji sub-catchment. These results underscore the importance of connectivity for surface source contributions.

Comparisons of recycled manure solids and wood shavings/sawdust as bedding material—Implications for animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds

Increasing shortages and costs of common bedding materials have led dairy farmers in Sweden to consider using recycled manure solids (RMS), which are readily available and low cost, as an alternative bedding material. The main risks are effects on udder health and milk quality, but RMS could also affect animal welfare and claw health. The advantages and disadvantages of using RMS bedding have not been fully investigated, and findings in other countries cannot be directly applied to Swedish conditions and climate. This observational cross-sectional study investigated the use of RMS as bedding, regarding associations with certain aspects of animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds. Thirty-four dairy farms using RMS or wood shavings/sawdust (each n = 17) were compared. Each farm was visited 2 times during the housing period from 2020 to 2021, once from October to December and once from March to May. Dairy barns were observed, animal welfare was assessed, and freestall dimensions were measured. Farm owners were interviewed about housing system characteristics, herd performance, and herd management. Data on milk production and herd health were obtained from the Swedish official milk recording scheme for the indoor period from October to March. The prevalence of claw disorders and abnormal claw conformation were collected from the national claw health database for the period from October to May. On each farm visit, composite samples of unused bedding outside the barn and used bedding material from the freestalls, respectively, were taken for total bacterial count and DM analysis. Samples of bulk tank milk for determination of total bacterial count were taken in connection to the visits. In addition, samples of unused and used bedding material and manure from alleys for analysis of 3 Treponema species associated with digital dermatitis (DD) were gathered and analyzed. Total bacterial count was significantly higher in unused (8.50 log10 cfu/g) and used RMS bedding (9.75 log10 cfu/g) than in wood shavings/sawdust (used 4.74; unused 8.63 log10 cfu/g), but there were no significant differences in bulk milk total bacterial count (median 4.07 vs. 3.89 log10 cfu/mL) or SCC (median 243,800 vs. 229,200 cells/mL). The aspects of animal welfare assessed did not differ significantly between the 2 bedding systems, whereas the prevalence of total claw disorders (25.9% vs. 38.0% of trimmed cows), dermatitis (6.9% vs. 16.2% of trimmed cows) and sole ulcers (2.0% vs. 4.0% of trimmed cows) were significantly lower in the RMS herds. Treponema spp. were not detected in unused RMS material, but all RMS herds had presence of DD recorded at foot trimming. An economic assessment based on the interview results and price level from winter 2021 revealed that the costs of RMS bedding varied with amount of RMS produced. Thus, RMS is a potential alternative bedding material for dairy cows in Sweden and can be a profitable option for large dairy herds. However, the high level of total bacteria in the material requires attention to bedding and milking routines as well as regular monitoring of herd health.

Conditioner application improves bedding quality and bacterial composition with potential beneficial impacts for dairy cow's health.

The use of Manure Pro (MP) conditioner improved recycled manure solids-bedding quality and this higher sanitary condition had further impacts on dairy cows' health with less potential mastitis pathogens significantly associated with bedding and teat skin samples of animals from MP group. The animals also presented an improved inflammation status, while milk quality was not modified. The use of MP conditioner on bedding may be of interest in controlling the risk of mastitis onset for dairy cows and further associated costs.

Methods of processing recycled manure solids bedding on Midwest dairy farms II: Relationships between bedding characteristics and bedding bacterial count

The first objective of this study was to identify bedding characteristics associated with bedding bacterial count (BBC) in ready-to-use (RTU) recycled manure solids (RMS). The second objective was to explore the association between processing method and bedding characteristics in RTU solids. A third objective was to investigate factors associated with BBC in used solids (after placed in stalls). This observational study recruited 29 premises in Minnesota and Wisconsin. Farms were visited twice, once in August of 2019 and again in January of 2020. At each visit, the herd manager/owner completed a questionnaire describing facilities, bedding and manure management, and mastitis control practices. Additionally, pre-processed RTU and used bedding samples were collected for determination of BBC (coliforms, Klebsiella spp., Streptococcus or Streptococcus-like organisms and Staphylococcus spp.) and bedding characteristics (dry matter [DM]), organic matter [OM], water soluble carbohydrates, total nitrogen, soluble nitrogen and pH). Mixed linear regression showed that increased DM, decreased OM and RMS processing method were all associated with reduced BBC in RTU RMS samples. Processing method for RMS was associated with DM, total nitrogen and soluble nitrogen, but not other characteristics in RTU RMS samples. Low BBC in RTU solids, decreased OM in RTU solids, and use of deep bedding systems were associated with lower BBC in used RMS. Implications for these findings are that producers should strive to put clean and high DM fresh (RTU) bedding into stalls. Monitoring BBC and DM in RTU solids may be of value for producers using RMS bedding.

Implementation of Fluidized Bed Concept to Improve Heat Transfer in Ecological Adsorption Cooling and Desalination Systems

Sustainable development policy focuses on reducing the carbon footprint generated by the global industry and energy sector. Replacing conventional energy sources with environmentally friendly ones requires advanced research to increase energy efficiency and reduce the instability and intermittence of renewable sources. Moreover, adsorption chillers are an opportunity to introduce net-zero emission technologies to the refrigeration, air-conditioning, and desalination industries. Adsorption devices could be popularized if a method of effective heat transfer in the volume of the adsorption bed is developed. The innovative concept of introducing fluidized beds into the adsorption system can achieve the most promising results in improving energy efficiency. To confirm the adopted assumption, heat transfer coefficient calculations for the packed and fluidized bed were carried out in this paper based on experimental tests and literature data. The empirical research aims to extend the fundamental knowledge in the implementation of fluidization under low-pressure conditions, characteristic of the adsorption systems’ working cycle. Experiments were conducted on a unique test stand equipped with the Intensified Heat Transfer Adsorption Bed (IHTAB) reactor prototype. Five adsorption bed samples were analyzed. The reference sample consisted only of silica gel, and the subsequent ones contained aluminum or carbon nanotubes with 5 and 10% additions. In the case of samples with admixtures, the fluidized state increased the heat transfer coefficient on average from approx. 36.9 W/m2 K to approx. 245.4 W/m2 K.

Dynamic mechanical performance of geogrid–waste tyre-reinforced railway ballast under cyclic loading

The accumulation of permanent deformation under cyclic loading in the granular bed is the main source of ballast track settlement. Therefore, studying the dynamic mechanical behaviour of reinforced railway track beds under cyclic loading is crucial. To reduce the accumulated of permanent deformation of railway track bed, geogrids–waste-tyre reinforced railway track bed was used to study in order to effectively control the permanent deformation of ballasted railway track bed. The test was conducted to investigate the mechanism of permanent deformation of geogrid–waste tyre-reinforced railway track bed through the evolution of cumulative plastic strain, permanent strain rate and dynamic elastic modulus of railway track bed under different confining pressures, dynamic stress amplitude, and amount of reinforcement. Results show that geogrid and waste tyre reinforcement have significant effects on the accumulated permanent deformation of the railway ballast. Geogrid reinforcement is better than waste tyres in improving the performance of the ballast fill. Reinforcement with geogrid significantly reduces the permanent strain rate, although the impact on this rate varies depending on the position and amount of reinforcement used. Notably, reinforcing the middle three layers of the track bed sample with waste tyres substantially decreases the permanent deformation rate. In contrast, the application of reinforcement across all five layers with waste tyres increases the permanent deformation rate. The dynamic elastic modulus of the track bed sample not only increases significantly but also rises with the dynamic stress amplitude due to the reinforcement of the geogrid and the waste tyre. The dynamic elastic modulus gradually stabilises with the increase in cyclic loading, indicating a stable accumulated deformation in the railway track bed.

Layer formation on quartz bed particles during fast pyrolysis of grass

Commercial fast pyrolysis technologies use bed materials, normally natural sand mainly consisting of quartz, acting as circulating heat carrier materials. Nowadays, the commercial conversion of biomass into fast pyrolysis bio-oil (FPBO) is still using ash-lean woody residues as a feedstock since the application of more abundant and possibly cheaper ash-rich agricultural biomass is currently at a significantly lower technology readiness level (TRL). To promote FPBO production from ash-rich biomass, the ash-related issues during the operation process need to be further studied. In the present investigation, the characteristics and formation process of layers formed on quartz bed particles, collected from a bench-scale fast pyrolysis unit based on the rotating cone technology, were studied. Two grass residues, representative of typical Si-K-rich agricultural biomass fuels, were used as feedstocks. Quartz bed particles at different sampling times from startup with fresh bed particles were collected. Scanning Electron Microscopy/Energy-Dispersive Spectroscopy (SEM/EDS) was employed to characterize the layer properties. Bed particle layers exhibited an uneven and discontinuous distribution on the quartz surface. This distribution over bed particles, as well as layer thickness, increased with the operational time. The dominating elements contained in layers were Si, K, Ca, and Cl (excluding O), which resembled that of individual bed ash particles found in the bed samples. In addition, the interpretation of the results was supported by thermodynamic equilibrium calculations. The findings suggest that the process of layer formation was governed by the direct adhesion of non-melted bed ash particles during the fast pyrolysis of grass.

Factors Influencing Milk Quality and Subclinical Mastitis in Dairy Herds Housed in Compost-Bedded Pack Barn System

The compost-bedded pack barn (CBPB) system has been increasingly adopted by dairy farms due to its ability to enhance animal comfort and milk production. This study evaluated the associations among bedding characteristics, milk quality and composition, and subclinical mastitis (SCM) occurrence in dairy herds housed in CBPB systems. Over a period of six months, data related to milk quality and udder health and bedding sampling were collected from eight dairy farms. Monthly measurements of the bedding temperature and wind speed inside the CBPB were taken, while temperature and relative humidity data inside the CBPB were recorded using a datalogger. Bedding samples were subjected to analysis of moisture, pH, microbiological count, and carbon/nitrogen ratio. Data on milk composition (fat, protein, milk urea nitrogen, and total solids) and quality (somatic cell count and standard plate count) of bulk tank milk were obtained from DHIA results. Canonical correlation analyses were used to evaluate the association between the analyzed group variables, and linear regression models were used to identify associations between bedding characteristics and SCM occurrence in the studied herds. The bedding characteristics that most influenced milk composition and quality were moisture, temperature at 30 cm depth (T30), and bedding pH. Environmental variables played an important role in bedding composting, as they were closely related to the surface temperature and pH. Overall, 62.71% of the variation in milk quality and composition could be explained by the bedding variables, and 77.50% of the variation in the bedding variables was associated with environmental variables. Median SCM prevalence and incidence were 28.6 and 13.8%, respectively. An increase of 1 °C for T30 resulted in a 0.6% reduction in the prevalence of SCM. Additionally, the bedding surface temperature at 22.3 °C resulted in the highest incidence of SCM (~18.1%). Our results demonstrate the importance of controlling microclimatic conditions in the CBPB to optimize the bedding composting process and milk quality.

PSX-30 Scratching the Surface: Investigating the Nature and Potential Causes of Pruritic Cattle

Abstract Depending on the year, during the winter months, cattle begin to rub bare patches on their skin due to pruritus which leads to concern from cattle producers, especially the purebred breeders. Upon further investigation by veterinarians, the cause is not always caused by lice, as many may think. This study aimed to provide insight into the cause and potential prevention/treatment of pruritic beef cattle in western Canada by examining herds that met the study’s criteria of having more than 30% of the herd exhibiting pruritus. Seven herds were examined in the winter of 2023: one from Manitoba, two from Saskatchewan, and four from Alberta. Producers from each herd completed a detailed survey on treatments, nutrition, and environmental conditions and provided feed, water, and bedding samples. Within each herd, five cattle considered non-pruritic, and ten cattle considered pruritic by visual appraisal were enrolled for standard data collection consisting of documentation and photos of skin lesions localized to pruritic areas, general health clinical exam, lice exam/collection, mite exam/collection of hairs, skin hydration (corneometer), blood chemistry and vitamin/minerals, and kidney/liver enzymes for mycotoxins. A subset of the group (1 non-pruritic and 4 pruritic) was selected for advanced data collection, including dermal hypersensitivity (grass, alfalfa, grain, weeds, and molds) measured by swelling score and infrared camera temperature measurement compared with positive and negative controls, skin punch biopsies for eosinophils (IgE) and liver biopsies for copper levels. Only 21/101 cattle had lice (18 animals < 10 lice per 6.5 cm2). No significant correlation was observed between cattle with lice and being pruritic (P > 0.05). Dermal hypersensitivity was very low across both pruritic and non-pruritic cattle and was not different (P > 0.05). Skin hydration readings within animals comparing pruritic and non-pruritic areas on their body showed only one herd having significantly (P < 0.05) drier skin on pruritic locations compared with normal locations. Vitamin A, E, and copper blood analysis showed no significant difference between pruritic and non-pruritic cattle. However, liver biopsy copper levels were (P = 0.01) less in pruritic than non-pruritic cattle. Results suggest that the cause of pruritic cattle is not necessarily a result of intense lice infestations but rather multifactorial in nature, and a decision tree for producers and veterinarians should be developed to aid in determining the correct course of action to alleviate pruritic cattle in the field.

Monitoring of Chemical Changes in Coffee Beans during the Roasting Process Using Different Roasting Technologies with Nuclear Magnetic Resonance Spectroscopy

The roasting process is an important step in coffee production, leading to important physical and chemical changes that are responsible for the sensory quality of a coffee beverage. Besides the commonly used drum roasters, a newly developed infrared roaster can be used to roast green coffee beans. In this study, 1H nuclear magnetic resonance (NMR) spectroscopy was used to analyze the fat and aqueous extracts of coffee beans roasted to different degrees of roasting using a professional drum roaster, a hot air fluidized bed sample roaster and an infrared roaster. Caffeine-containing and decaffeinated Coffea arabica coffee samples were used to monitor the roasting process in the different roasters. Compared with the drum-roasted coffee sample, the formation and degradation of NMR-detectable components in the coffee sample roasted with the infrared roaster and the hot air roaster were time-dependent. In the decaffeinated coffee sample, compounds such as kahweol, caffeoylquinic acid and trigonelline were found to occur at lower levels. The formation and degradation of the NMR-detectable compounds in the decaffeinated coffee sample also occurred with a time lag or to a lesser extent than in the caffeine-containing coffee sample.

Margin Assessment Methods in Oral Cavity Squamous Cell Carcinoma and Recurrence

Positive margins and margin clearance are risk factors for recurrence in oral cavity squamous cell carcinoma (OCSCC), and these features are used to guide decisions regarding adjuvant radiation treatment. However, the prognostic value of intraoperative tumor bed vs resection specimen sampling is not well defined. To determine the prognostic implications of intraoperative margin assessment methods (tumor bed vs resection specimen sampling) with recurrence among patients who undergo surgical resection for OCSCC. This was a retrospective study of patients who had undergone surgical resection of OCSCC between January 1, 2000, and December 31, 2021, at a tertiary-level academic institution. Patients were grouped by margin assessment method (tumor bed [defect] or resection specimen sampling). Of 223 patients with OCSCC, 109 patients had localized tumors (pT1-T2, cN0), 154 had advanced tumors, and 40 were included in both cohorts. Disease recurrence after surgery was estimated by the cumulative incidence method and compared between cohorts using hazard ratios (HRs). Data analyses were performed from January 5, 2023, to April 30, 2023. Recurrence-free survival (RFS). The study population comprised 223 patients (mean [SD] age, 62.7 [12.0] years; 88 (39.5%) female and 200 [90.0%] White individuals) of whom 158 (70.9%) had defect-driven and 65 (29.1%) had specimen-driven margin sampling. Among the 109 patients with localized cancer, intraoperative positive margins were found in 5 of 67 (7.5%) vs 8 of 42 (19.0%) for defect- vs specimen-driven sampling, respectively. Final positive margins were 3.0% for defect- (2 of 67) and 2.4% for specimen-driven (1 of 42) margin assessment. Among the 154 patients with advanced cancer, intraoperative positive margins were found in 29 of 114 (25.4%) vs 13 of 40 (32.5%) for defect- and specimen-driven margins, respectively. Final positive margins were higher in the defect-driven group (9 of 114 [7.9%] vs 1 of 40 [2.5%]). When stratified by margin assessment method, the 3-year rates of local recurrence (9.7% vs 5.1%; HR, 1.37; 95% CI, 0.51-3.66), regional recurrence (11.0% vs 10.4%; HR, 0.85; 95% CI, 0.37-1.94), and distant recurrence (6.4% vs 5.0%; HR, 1.10; 95% CI, 0.36-3.35) were not different for defect- vs specimen-driven sampling cohorts, respectively. The 3-year rate of any recurrence was 18.9% in the defect- and 15.2% in the specimen-driven cohort (HR, 0.93; 95% CI, 0.48-1.81). There were no differences in cumulative incidence of disease recurrence when comparing defect- vs specimen-driven cases. The findings of this retrospective cohort study indicate that margin assessment methods using either defect- or specimen-driven sampling did not demonstrate a clear association with the risk of recurrence after OCSCC resection. Specimen-driven sampling may be associated with reduced surgical margin positivity rates, which often necessitate concurrent chemotherapy with adjuvant radiation therapy.

Molecular characterization and genetic diversity of Wolbachia endosymbionts in bed bugs (Hemiptera; Cimicidae) collected in Paris.

This study aimed to investigate the genetic diversity of Wolbachia in field-caught bed bug species in Paris areas. The bed bug specimens were captured from various infested localities in Paris and surrounding cities. They belonged to diverse life stages, including egg, nymph, and adult. They were then identified using morphological and molecular approaches. Furthermore, Wolbachia was detected, and its genetic diversity was investigated by conventional PCR of 16S-rRNA and Wolbachia surface protein (wsp) genes. A total of 256 bed bug specimens belonging to various life stages [adult (183 specimens), nymph (48), and egg (25)] were captured from seven private apartments, five social apartments, three houses, two immigrant residences, and one retirement home situated in 10 districts of Paris and 8 surrounding cities. They were identified as Cimex lectularius (237 specimens) and C. hemipterus (19) using morphological and molecular approaches. The presence and diversity of Wolbachia were ascertained by targeting 16S-rRNA and wsp genes. Based on molecular analysis, 182 and 148 out of 256 processed specimens were positive by amplifying 16S-rRNA and wsp fragments, respectively. The inferred phylogenetic analysis with 16S-rRNA and wsp sequences displayed monophyletic Wolbachia strains clustering each one in three populations. The median-joining network, including the Wolbachia 16S-rRNA and wsp sequences of C. lectularius and C. hemipterous specimens, indicated a significant genetic differentiation among these populations in Paris areas which was consent with Neighbor-Joining analyses. A phylogenetic analysis of our heterogenic Wolbachia sequences with those reported from other arthropod species confirmed their belonging to supergroup F. Moreover, no difference between Wolbachia sequences from eggs, nymphs, and adults belonging to the same clade and between Wolbachia sequences of C. lectularius and C. hemipterus were observed after sequence alignment. Furthermore, no significant correlation was found between multiple geographical locations (or accomodation type) where bed bugs were collected and the genetic diversity of Wolbachia. We highlight a significant heterogeneity within Wolbachia symbionts detected in C. lectularius and C. hemipterus. No correlation between Wolbachia species and bed bug species (C. lectularius versus C. hemipterus), physiological stages (egg, nymph, and adult), and sampling location was recorded in this study.

Floating rooted hydrophytes and flow and sediment dynamics: Field study in secondary channels of the Paraná River

Worldwide, aquatic vegetation is a key component in many river systems due to its diverse interactions as well as the environmental services it provides. In the Paraná fluvial system, large mats of floating rooted hydrophytes are present in channels with different water conditions whose interaction with flow and sediment dynamics is currently unknown. This work aimed to evaluate the temporal coverage variation of floating rooted hydrophytic mats as well as the alteration of flow dynamic and sediment deposition associated with their presence in natural conditions. Four different secondary channels were analyzed for two different and consecutive water stages: mean and high-water levels. Hydrophytic coverage ranged from 5% to 67% and from about 3% to 14% of the total discharge drained throughout the vegetated areas of the channels, being the lowest values recorded during the high-water stage. The specific discharge distribution and flow velocities at the vegetated cross-sections were altered when compared to non-vegetated sections. Mean velocities and depths were markedly lower inside vegetation mats. Additionally, fine sediments (silt and clay) dominated the bed samples below the hydrophytic mats of the vegetated sections in all the channels and water level stages under study. Nonetheless, the highest wash load was mainly recorded outside the hydrophytic mats during mean waters, while it was registered within the mats during high waters. Grain size of bed material below the hydrophytic mats as well as flow velocities inside them indicated sedimentation promoted by the hydrophytic mats. Understanding how flow and sediment deposition can be altered by hydrophytic mats is of great relevance not only in terms of the role they play in the Paraná fluvial dynamics, but also for their appropriate inclusion in hydraulic field measurements and hydrodynamic models widely used to predict such dynamics.

Additive manufacturing process parameter determination for a new Fe-C-Cu alloy

As a potential replacement for stainless steel alloys commonly used to print parts with laser powder bed fusion, a new Cu precipitation strengthened ferrous alloy, with composition Fe-0.2C-6Cu (wt%), was recently developed. This material is Co- and Ni-free, printable, has mechanical properties comparable to that of high strength stainless steels (approximately 1300 MPa UTS), and is cost-advantaged relative to existing low-alloy steels for additive manufacturing of parts with complex shapes. To gain traction for broader application, optimal laser powder bed fusion (LPBF) processing conditions to produce nearly defect-free parts without compromising mechanical strength are needed. Here, an optimal processing window based upon laser speeds that achieve minimal porosity was quantified via comparisons of measured melt pool penetration, scan speeds, printed material density and laser beam energy density on a commercial LPBF unit operating at 350 W, 80 μm hatch spacing, and 50 μm layer thickness based upon optimal parameters for 17-4PH. The window is 300 to 500 mm/s to achieve >99.8 % dense Fe-0.2C-6Cu (wt%) specimens. Other defects such as burning, spatter, and lack of fusion were also avoided in this window. The window was validated with in-situ synchrotron X-ray imaging that enabled visualization of the vapor cavity, melting, and solidification during a single laser track scan on a miniature powder bed sample. In addition, in-situ infrared imaging provided temperature fields, cooling rate and solidification range, and confirmed minimal printing defects and spatter within the processing window.

Mycobacterium avium subsp. Paratuberculosis in Different Environmental Samples from a Dairy Goat Barn-Implications for Sampling Strategies for Paratuberculosis Diagnostic and Prevention.

Environmental samples are often used to classify the paratuberculosis status of cattle herds. The disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP), predominantly through oral ingestion during infancy. In this explorative study, the presence of MAP was determined in the barn environment of a paratuberculosis-infected vaccinated dairy goat herd. A total of 256 bedding, dust, feed, and water samples were collected at eight time points and examined using culture and qPCR. Detection rates of both methods were compared, and factors determining MAP confirmation were identified. MAP was cultured from 28 bedding and one dust sample, while MAP DNA was detected in all materials (117/256). Samples from high animal traffic areas and those collected during the indoor season were more likely to yield positive culture and qPCR results. Cultivation of MAP from kidding pens indicated this area as a possible infection site. Dust proved to be the most suitable material for detecting MAP DNA, as bedding was for MAP culture. Environmental sampling was demonstrated to be an effective way to detect MAP in a dairy goat herd. qPCR results could confirm herd infection, while culture results provided insight into crucial areas for MAP transmission. These findings should be considered when designing farm-specific paratuberculosis control plans.

Methods of processing recycled manure solids bedding on Midwest dairy farms I: Associations with bedding bacteria counts, milk quality, udder health and milk production

This observational study investigated the relationships between method of processing recycled manure solids (RMS) bedding and 1) bacteria counts in RMS bedding, 2) bacteria counts in bulk tank milk, and 3) udder health and milk production. A convenience sample of 29 farms in Minnesota and Wisconsin were recruited to represent 4 RMS processing systems; green (GRN, n = 7), anaerobic digestion (DIG, n = 6), composting (COM, n = 4), and hot air drying (DRY, n = 12). Premises were visited twice (summer/winter) to collect fresh bedding and bulk tank milk (BTM) samples for culture, test day records, and a herd management questionnaire.
 Coliform and Klebsiella spp. counts were lower, or tended to be lower in DRY, COM or DIG versus GRN RMS samples. Counts of Streptococci and Strep-like organisms (SSLO) were statistically or numerically lower in COM or DRY as compared to GRN or DIG RMS samples. Coliform and SSLO counts in BTM were lower, or tended to be lower, in DIG, COM or DRY as compared to GRN RMS samples. Test-day average linear score, proportion of cows with infection, and proportion of cows with chronic infection was lower, or tended to be lower, in herds using DRY or COM versus GRN RMS bedding. Average 305ME was higher, or tended to be higher, for herds using DRY versus GRN or DIG RMS. Adoption of COM or DRY processing could allow producers to mitigate the negative impacts of high bacteria levels in GRN RMS bedding, though more research is needed.

Investigation of uterine microbiota in postpartum dairy cows and barn environment by quantitative PCR technique

The objective of this study was to investigate uterine microbiota in postpartum dairy cows and barn environment by quantitative PCR and to evaluate the correlation between the microbiota in the uterus and barn environment. The study was carried out in 2 seasons of the year: summer (June to August 2017) and winter (October 2017 to March 2018) on Holstein dairy cow farm, Okayama Livestock Research Institute, Japan. A total of 116 samples, including 68 uterine and fecal samples, were collected from 9 cows in summer and 8 cows in winter, at 1 and 2 months after calving. Additionally, 48 samples of barn environment including airborne dust, bedding, feed and water samples were collected 6 times throughout each season. The quantative PCR results showed significant differences (P < 0.05) in the uterine and fecal microbiota of dairy cows at 1 and 2 months after calving. In summer, total bacteria at 2 months postpartum were higher than those at 1 month after calving, while total bacteria were the same in winter (P > 0.05). Bacteroidetes and Firmicutes in uterus and feces between 1 and 2 months after calving were not significantly different in both summer and winter (P > 0.05). The populations of Bacteroidetes, Firmicutes, and total bacteria were found to be highest in bedding compared to those in feed, airborne dust, and water from the barn environment (P < 0.05). Bacteroidetes, Firmicutes and total bacteria in uterus were closely related with those in bedding in summer, however they had the negative correlation with the microbiota of barn environment in winter, especially with fecal microbiota.