Influence of hay feeding method, supplement moisture, or access time on intake and waste by beef cows.

Experiments were performed to determine the effects of feeding method and hay processing (Experiment 1), energy supplement moisture content and feeding method (Experiment 2), and access time to hay (Experiment 3) on cow body weight (BW), dry matter intake (DMI), and hay or energy supplement intake and waste. Experiment 1 was designed as a 4 × 4 Latin Square using 48 multiparous, late-gestating, Angus cows (626 kg initial BW). Cows were stratified by age and BW into four treatment groups (n = 12 cows/group); treatment groups were then initially assigned randomly to treatments in a sequence of preset Latin Square periods. In Experiment 1, round bales were processed and delivered on the pen surface or in a bunk, or left unprocessed and delivered in a hay ring or rolled out on the pen surface. Experiment 2 was designed as a 6 × 6 Latin Square utilizing 54 multiparous, late-gestating, Angus cows (616 kg initial BW). Cows were stratified by age and BW into treatment groups (n = 9 cows/group); treatment groups were then initially assigned randomly to treatments in a sequence of preset Latin Square periods. In Experiment 2, corn screenings (CS) or wet beet pulp (BP) were fed in a structure (inverted tire or bunk) or BP only on the pen surface. Experiment 3 was designed as a replicated 3 × 3 Latin Square utilizing 24 multiparous, late-gestating, Angus cows (584 kg initial BW). Cows were stratified by age and BW into treatment groups (n = 8 cows/group); treatment groups were then initially assigned randomly to treatments in a sequence of preset Latin Square periods. In Experiment 3, cows were permitted access to round-bales in a hay ring for 6, 14, or 24 h. In Experiment 1, hay DMI was not affected (P ≥ 0.579). Hay waste was greater (P ≤ 0.007) when hay, processed or not, was fed on the pen surface. In Experiment 2, hay DMI was greatest (P ≤ 0.011) for cows fed no supplement and those fed CS in a bunk. Feeding BP in a bunk led to the greatest (P ≤ 0.003) hay waste. In Experiment 3, cows permitted 6-h access consumed and wasted less (P < 0.001) hay compared with those permitted longer access; BW was unaffected (P ≥ 0.870). In these experiments, cows fed hay on the pen surface, processed or not, achieved similar DMI as those fed in a ring or bunk, but wasted more hay. Delivering BP in a bunk or on the pen surface increased hay and supplement waste, respectively. Controlling access to hay reduced DMI and waste while maintaining cow BW.

The effectiveness of commercial desiccants and uncooked rice in removing moisture from hearing aids.

OBJECTIVE: In many low- and middle-income countries, the availability of hearing technology is limited, with few options for hearing aid repairs. Minimising moisture damage to hearing aid electronics improves function and longevity; however, desiccants that absorb moisture from hearing aid components are unavailable in many regions. This study compared the effectiveness of uncooked white rice and seven commercial silica gel desiccants in removing moisture from hearing aids. DESIGN: Relative humidity measurements in a test chamber were obtained from a water-saturated BTE hearing aid prior to and after placement in uncooked white rice and seven different silica gel desiccants. STUDY SAMPLE: Two BTE hearing aids, seven silica gel desiccants and white rice comprised the study sample. RESULTS: All desiccants and the white rice were effective in removing moisture from hearing aids, with Hal Hen Super Dri Aid showing the largest mean reduction in relative humidity. Based on analysis of covariance results, white rice was statistically similar to several of the commercial desiccants. CONCLUSIONS: White rice shows promise as an effective alternative to commercial desiccants in reducing moisture in hearing aids when silica gel products are unavailable. As this study was conducted in a relatively dry region, additional research may be needed.

Using a biomimetic membrane surface experiment to investigate the activity of the magnetite biomineralisation protein Mms6.

Magnetotactic bacteria are able to synthesise precise nanoparticles of the iron oxide magnetite within their cells. These particles are formed in dedicated organelles termed magnetosomes. These lipid membrane compartments use a range of biomineralisation proteins to nucleate and regulate the magnetite crystallisation process. A key component is the membrane protein Mms6, which binds to iron ions and helps to control the formation of the inorganic core. We have previously used Mms6 on gold surfaces patterned with a self-assembled monolayer to successfully produce arrays of magnetic nanoparticles. Here we use this surface system as a mimic of the interior face of the magnetosome membrane to study differences between intact Mms6 and the acid-rich C-terminal peptide subregion of the Mms6 protein. When immobilised on surfaces, the peptide is unable to reproduce the particle size or homogeneity control exhibited by the full Mms6 protein in our experimental setup. Moreover, the peptide is unable to support anchoring of a dense array of nanoparticles to the surface. This system also allows us to deconvolute particle binding from particle nucleation, and shows that Mms6 particle binding is less efficient when supplied with preformed magnetite nanoparticles when compared to particles precipitated from solution in the presence of the surface immobilised Mms6. This suggests that Mms6 binds to iron ions rather than to magnetite surfaces in our system, and is perhaps a nucleating agent rather than a controller of magnetite crystal growth. The comparison between the peptide and the protein under identical experimental conditions indicates that the full length sequence is required to support the full function of Mms6 on surfaces.

Taking a hard line with biotemplating: cobalt-doped magnetite magnetic nanoparticle arrays.

Rapid advancements made in technology, and the drive towards miniaturisation, means that we require reliable, sustainable and cost effective methods of manufacturing a wide range of nanomaterials. In this bioinspired study, we take advantage of millions of years of evolution, and adapt a biomineralisation protein for surface patterning of biotemplated magnetic nanoparticles (MNPs). We employ soft-lithographic micro-contact printing to pattern a recombinant version of the biomineralisation protein Mms6 (derived from the magnetotactic bacterium Magnetospirillum magneticum AMB-1). The Mms6 attaches to gold surfaces via a cysteine residue introduced into the N-terminal region. The surface bound protein biotemplates highly uniform MNPs of magnetite onto patterned surfaces during an aqueous mineralisation reaction (with a mean diameter of 90 ± 15 nm). The simple addition of 6% cobalt to the mineralisation reaction maintains the uniformity in grain size (with a mean diameter of 84 ± 14 nm), and results in the production of MNPs with a much higher coercivity (increased from ≈ 156 Oe to ≈ 377 Oe). Biotemplating magnetic nanoparticles on patterned surfaces could form a novel, environmentally friendly route for the production of bit-patterned media, potentially the next generation of ultra-high density magnetic data storage devices. This is a simple method to fine-tune the magnetic hardness of the surface biotemplated MNPs, and could easily be adapted to biotemplate a wide range of different nanomaterials on surfaces to create a range of biologically templated devices.

Blood conservation and pain control in scoliosis corrective surgery: an online survey of UK practice.

BACKGROUND: Discussion at local meetings led to the realization of the diversity in anaesthetic practice for pediatric and adolescent scoliosis surgery. This diversity was assessed using an online survey, the aim being to provoke discussion and highlight areas of future research. METHODS: Of the 24 centers practicing pediatric and adolescent scoliosis surgery, 21 completed questionnaires, a response rate of 88%. RESULTS: Blood conservation; the area of greatest clinical variability was seen in dosing regimes for Tranexamic acid. Thromboprophylaxis; both mechanical and pharmacological regimes showed wide range in both application and timing. Pain control; eight different types of postoperative pain relief were utilized across the centres, some in isolation but many in combination. CONCLUSIONS: The results from our survey show wide variation nationally and hopefully will provoke discussion and ultimately national multi-centred research to define best practice.

Comparative studies on bull and stallion seminal DNase activity and interaction with semen extender and spermatozoa.

We performed a series of comparative studies of bull and stallion seminal plasma (SP) and its role on sperm-neutrophil binding as well as the interaction between semen extender and seminal DNase. Because of contrasting roles of SP on sperm-neutrophil binding between horses and cattle, it was suspected there were some species-specific differences on sperm interaction with SP proteins due to the variations in the natural location of semen deposition (uterus compared to vagina). Bull frozen-thawed sperm removed from egg yolk extender showed similar results to fresh sperm, but this also caused extensive sperm agglutination unless SP or egg yolk was included. If similar agglutination occurs after AI with frozen bull semen, it could interfere with sperm transport or sperm functions. Commonly used bull semen extenders were poor media for seminal DNase activity on plasmid DNA degradation, raising the prospect that the same may be true with other SP factors important to fertility. DNase activity per mg SP protein of bulls was less than that of horses (P<0.05), but DNase activity associated with bull sperm was greater (P<0.05) indicating a different affinity of DNase to spermatozoa. This could be related to the fact that bull sperm naturally migrate from the vagina to the uterus leaving the bulk of SP behind. In such migration, sperm cells needed to carry DNase and other SP factors along. Incorporation of egg yolk in bull semen and introducing SP into the uterus of cattle with current AI protocols may contribute to reduced fertility. Modifications of semen extender and/or semen processing should be examined to allow sperm cells a maximum potential for fertilization.

Species-specific interaction of seminal plasma on sperm-neutrophil binding.

Bovine semen is naturally deposited in the vagina and spermatozoa migrate through the cervix into the uterus leaving the bulk of seminal plasma (SP) behind. In equine, both spermatozoa and SP are deposited directly in the uterus and SP reduces sperm binding to neutrophils and prevents the formation of DNA-based neutrophil extracellular traps (NETs). We investigated the role of bovine SP on sperm-neutrophil binding using the four most common bovine semen extenders. Contrary to equine, bovine spermatozoa removed from SP had low binding to neutrophils for up to 3h, but as little as 10% SP increased sperm-neutrophil binding and NETs formation over time. Similar results were obtained with neutrophils isolated from peripheral blood or from the uterus. Scanning electron microscopy showed that the binding can be mediated by NETs or by direct attachment of the cell membranes for both species. The increased binding with SP reduced the number of free spermatozoa indicating that sperm transport to the site of fertilization (and thus fertility) may be hindered. Surprisingly, egg yolk negated the role of bovine SP on sperm-neutrophil binding compared to all the other semen extenders, but did not alter equine sperm binding to neutrophils. Current artificial insemination in bovine relies heavily on egg yolk extender and introduces variable amounts of SP into the uterus, which naturally remains in the vagina. Our results indicate a need to re-evaluate the composition of semen extenders and the semen processing procedures in relation to sperm transport, longevity and fertilizing ability.

Defibrillation during renal dialysis: a survey of UK practice and procedural recommendations.

INTRODUCTION: Defibrillation of patients connected to medical equipment that is not defibrillation proof risks ineffective defibrillation and harm to the operator as a result of aberrant electrical pathways taken by the defibrillation current. Many renal dialysis systems are not currently defibrillation proof. Although national and international safety standards caution against defibrillating under this circumstance, it appears to be an area of confusion that we have investigated in more detail. METHODS: Thirty renal dialysis units across the UK were invited to participate in a telephone survey of current practice from 1 October 2004 to 1 October 2005. The Medical Healthcare Regulatory Agency and renal dialysis machine manufacturers were contacted for advice, and current safety standards were reviewed. RESULTS: Twenty-eight renal dialysis units completed the survey. Seven (25%) units would not disconnect patients from dialysis equipment during defibrillation, collectively reporting 14 patients who had required defibrillation during dialysis. Eighteen (64.3%) units would disconnect patients from dialysis equipment during defibrillation, collectively reporting 29 patients who had required defibrillation during dialysis. No complications were identified by this survey, through the MHRA or through a literature search. CONCLUSION: Defibrillation of patients while undergoing renal dialysis is common practice in the UK. Although no adverse events have been reported, this practice risks injury to the patient and clinical staff, and equipment damage if the dialysis equipment is not defibrillation proof. It is in breach of national and international safety standards and should not be practiced.