36 research outputs found
Bovine Mammary Gland Biopsy Techniques
Bovine mammary gland biopsies allow researchers to collect tissue samples to study cell biology including gene expression, histological analysis, signaling pathways, and protein translation. This article describes two techniques for biopsy of the bovine mammary gland (MG). Three healthy Holstein dairy cows were the subjects. Before biopsies, cows were milked and subsequently restrained in a cattle chute. An analgesic (flunixin meglumine, 1.1 to 2.2 mg/kg of body weight) was administered via jugular intravenous [IV] injection 15-20 min prior to biopsy. For standing sedation, xylazine hydrochloride (0.01-0.05 mg/kg of body weight) was injected via the coccygeal vessels 5-10 min before the procedure. Once adequately sedated, the biopsy site was aseptically prepared and locally anaesthetized with 6 mL of 2% lidocaine hydrochloride via subcutaneous injection. Using aseptic technique, a 2 to 3 cm vertical incision was made using a number 10 scalpel. Core and needle biopsy tools were used. The core biopsy tool was attached to a cordless drill and inserted into the MG tissue through the incision using a clock-wise drill action. The needle biopsy tool was manually inserted into the incision site. Immediately after the procedure, an assistant applied pressure on the incision site for 20 to 25 min using a sterile towel to achieve hemostasis. Stainless steel surgical staples were used to oppose the skin incision. The staples were removed 10 days post-procedure. The main advantages of core and needle biopsies is that both approaches are minimally invasive procedures that can be safely performed in healthy cows. Milk yield following the biopsy was unaffected. These procedures require a short recovery time and result in fewer risks of complications. Specific limitations may include bleeding after the biopsy and infection on the biopsy site. Applications of these techniques include tissue collection for clinical diagnosis and research purposes, such as primary cell culture
Zinc, Copper, and Manganese Homeostasis and Potential Trace Metal Accumulation in Dairy Cows: Longitudinal Study from Late Lactation to Subsequent Mid-Lactation
BackgroundTrace metals are supplemented to cattle to prevent nutrient deficiencies. Levels supplemented to mitigate worst-case basal supply and availability scenarios can, however, result in trace metal intakes far above nutritional requirements of dairy cows with high feed intakes.ObjectivesWe evaluated Zn, Mn and Cu balance in dairy cows from late lactation through the subsequent mid-lactation, a period of 24 wk characterized by large changes in dry matter intake.MethodsTwelve Holstein dairy cows were housed in a tie-stall from 10 wk before to 16 wk after parturition, and fed one unique lactation diet when lactating, and a dry cow diet otherwise. After two weeks of adaptation to the facility and diet, Zn, Mn and Cu balances were determined at weekly intervals, by calculating the difference between total intakes and complete fecal, urinary and milk outputs, with the latter three fluxes quantified over a 48-h period. Repeated measures mixed models were used to evaluate the effects on trace mineral balances over time.ResultsThe Mn and Cu balances of cows were not significantly different from 0 mg·d-1 between 8 wk prepartum and calving (P ≥ 0.54), when dietary intake was the lowest of the period evaluated. However, when dietary intake was highest, between wk 6 and 16 postpartum, positive Mn and Cu balances were observed (80 and 20 mg·d-1, respectively, P ≤ 0.05). Cows were in positive Zn balance throughout the study except during the first 3 wk after calving during which Zn balance was negative.ConclusionsLarge adaptations occur in trace metal homeostasis in transition cows in response to changes in dietary intake. High dry-matter intakes, associated with high milk production of dairy cows, combined with current Zn, Mn and Cu supplementation practices may exceed regulatory homeostatic mechanisms resulting in potential body accumulation of Zn, Mn and Cu.Keywords: health; environment; accumulation; regulation; dietary supplementatio
ERIS: revitalising an adaptive optics instrument for the VLT
ERIS is an instrument that will both extend and enhance the fundamental
diffraction limited imaging and spectroscopy capability for the VLT. It will
replace two instruments that are now being maintained beyond their operational
lifetimes, combine their functionality on a single focus, provide a new
wavefront sensing module that makes use of the facility Adaptive Optics System,
and considerably improve their performance. The instrument will be competitive
with respect to JWST in several regimes, and has outstanding potential for
studies of the Galactic Center, exoplanets, and high redshift galaxies. ERIS
had its final design review in 2017, and is expected to be on sky in 2020. This
contribution describes the instrument concept, outlines its expected
performance, and highlights where it will most excel.Comment: 12 pages, Proc SPIE 10702 "Ground-Based and Airborne Instrumentation
for Astronomy VII
Stability and Fluctuations in Complex Ecological Systems
From 08-12 August, 2022, 32 individuals participated in a workshop, Stability
and Fluctuations in Complex Ecological Systems, at the Lorentz Center, located
in Leiden, The Netherlands. An interdisciplinary dialogue between ecologists,
mathematicians, and physicists provided a foundation of important problems to
consider over the next 5-10 years. This paper outlines eight areas including
(1) improving our understanding of the effect of scale, both temporal and
spatial, for both deterministic and stochastic problems; (2) clarifying the
different terminologies and definitions used in different scientific fields;
(3) developing a comprehensive set of data analysis techniques arising from
different fields but which can be used together to improve our understanding of
existing data sets; (4) having theoreticians/computational scientists
collaborate closely with empirical ecologists to determine what new data should
be collected; (5) improving our knowledge of how to protect and/or restore
ecosystems; (6) incorporating socio-economic effects into models of ecosystems;
(7) improving our understanding of the role of deterministic and stochastic
fluctuations; (8) studying the current state of biodiversity at the functional
level, taxa level and genome level.Comment: 22 page
Non-Contrast MRI Methods as a Tool for the Pre-Operative Assessment and Surveillance of the Arterio-Venous Fistula for Haemodialysis
Recent progress in the upgrade of the TCV EC-system with two 1MW/2s dual-frequency (84/126GHz) gyrotrons
The upgrade of the EC-system of the TCV tokamak has entered in its realization phase and is part of a broader upgrade of TCV. The MW-class dual-frequency gyrotrons (84 or 126GHz/2s/1MW) are presently being manufactured by Thales Electron Devices with the first gyrotron foreseen to be delivered at SPC by the end of 2017. In parallel to the gyrotron development, for extending the level of operational flexibility of the TCV EC-system the integration of the dual-frequency gyrotrons adds a significant complexity in the evacuated 63.5mm-diameter HE11 transmission line system connected to the various TCV low-field side and top launchers. As discussed in [1], an important part of the present TCV-upgrade consists in inserting a modular closed divertor chamber. This will have an impact on the X3 top-launcher which will have to be reduced in size. For using the new compact launcher we are considering employing a Fast Directional Switch (FADIS), combining the two 1MW/126GHz/2s rf-beams into a single 2MW rf-beam
Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation
Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Emerging Themes and Future Directions of Multi-Sector Nexus Research and Implementation
Water, energy, and food are all essential components of human societies. Collectively, their respective resource systems are interconnected in what is called the “nexus”. There is growing consensus that a holistic understanding of the interdependencies and trade-offs between these sectors and other related systems is critical to solving many of the global challenges they present. While nexus research has grown exponentially since 2011, there is no unified, overarching approach, and the implementation of concepts remains hampered by the lack of clear case studies. Here, we present the results of a collaborative thought exercise involving 75 scientists and summarize them into 10 key recommendations covering: the most critical nexus issues of today, emerging themes, and where future efforts should be directed. We conclude that a nexus community of practice to promote open communication among researchers, to maintain and share standardized datasets, and to develop applied case studies will facilitate transparent comparisons of models and encourage the adoption of nexus approaches in practice
Feeding and post-ruminal infusion of calcium gluconate to lactating dairy cows
Gluconic acid was proposed as a prebiotic for non-ruminants; however, a ruminant application is undescribed. The first experiment was a 5 x 5 Latin Square with five test doses of calcium gluconate (CaG): 0, 5, 17, 32 and 46 g/d. Treatments were infused into the omasum of lactating dairy cows for 28 d and milk was collected on d 26, 27 and 28. The second experiment was a cross-over where cows (N = 30) were fed a TMR with (0.2 % of DM) and without CaG for 28 d. Milk (d 26, 27 and 28) and blood (d 28) were collected from all cows and rumen fluid (d 28) from a subset of 6 rumen cannulated cows. Infusion of CaG into the omasum increased milk fat yield and decreased DMI resulting in improved feed efficiency. In contrast, cows fed CaG in the TMR had decreased milk yield and milk protein and lactose yields compared to CON. In the subset of rumen cannulated cows, the proportion of butyric acid was decreased and acetic acid increased relative to total VFA in cows fed the CaG. These findings suggest that CaG utilization may be different in the rumen and lower gastrointestinal tract.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author