Phase separation dynamics in colloid-polymer mixtures: the effect of interaction range

Colloid-polymer mixtures may undergo either fluid-fluid phase separation or gelation. This depends on the depth of the quench (polymer concentration) and polymer-colloid size ratio. We present a real-space study of dynamics in phase separating colloid-polymer mixtures with medium- to long-range attractions (polymer-colloid size ratio q_R=0.45-0.89, with the aim of understanding the mechanism of gelation as the range of the attraction is changed. In contrast to previous studies of short-range attractive systems, where gelation occurs shortly after crossing the equilibrium phase boundary, we find a substantial region of fluid-fluid phase separation. On deeper quenches the system undergoes a continuous crossover to gel formation. We identify two regimes, `classical' phase separation, where single particle relaxation is faster than the dynamics of phase separation, and `viscoelastic' phase separation, where demixing is slowed down appreciably due to slow dynamics in the colloid-rich phase. Particles at the surface of the strands of the network exhibit significantly greater mobility than those buried inside the gel strand which presents a method for coarsening.Comment: 8 page

The Effect of Recombinant Bovine Somatotropin on Patterns of Milk Production, Lactational Milk Estimates and Net Farm Income

Bovine somatoropin (bST) alters total milk production and production patterns in dairy cows and understanding the economic benefits of bST for the dairy producer are critical. Holstein cows (n = 555) from four Michigan dairy farms were randomly assigned as untreated controls or to receive 500 mg of bovine somatotropin (PosilacR) administered every 14 days beginning at 63 to 69 days of lactation and continuing until approximately 21 days prior to the end of lactation or until the animal was removed from the herd. Average peak milk production was 50.8 kg / day and occurred at an average of 113 9 days of lactation for bST-treated cows while average peak production was 48.9 kg / day occurring at an average of 86.4 days of lactation for control cows; both parameters were significantly greater for bST-treated cows compared to controls. Study cows treated with bST were significantly more persistent in lactation (7% greater lactational persistency) compared to control cows. All DHIA estimates and actual milk produced were not significantly different between the study treatment groups for any of the four comparisons made (first, second, third monthly tests after bST treatment initiation and final (305-day) DHIA production estimates); however, the accuracy of DHIA production estimates was significantly affect by the amount of time elapsed since bST but became non-significant by the third DHIA test date. The use of bST changed NFI for each of the four study farms by $96.21,$3.57, $78.71 and ($7.15) per bST-treated cow, respectively during the trial period (from 63 to 305 days of lactation). The overall average change in NFI attributable to bST was $43.01 per bST-treated cow. 2 Profitability of bST use was observed to be quite variable between farms studied because many factors were found to affect the change in NFI per cow resulting from bST use; the level of production response and the price received for milk had the largest effects on the change in NFI associated with bST use; by contrast, price paid for bST itself and feed had only minimal effects on bST-associated profitability. Diseases that may be associated with bST may reduce the profitability of this product and need to be considered as a cost of bST use if present.bovine somatotropin, dairy, net farm income, Farm Management, Livestock Production/Industries, Productivity Analysis, Research and Development/Tech Change/Emerging,

The effect of boundary adaptivity on hexagonal ordering and bistability in circularly confined quasi hard discs

The behaviour of materials under spatial confinement is sensitively dependent on the nature of the confining boundaries. In two dimensions, confinement within a hard circular boundary inhibits the hexagonal ordering observed in bulk systems at high density. Using colloidal experiments and Monte Carlo simulations, we investigate two model systems of quasi hard discs under circularly symmetric confinement. The first system employs an adaptive circular boundary, defined experimentally using holographic optical tweezers. We show that deformation of this boundary allows, and indeed is required for, hexagonal ordering in the confined system. The second system employs a circularly symmetric optical potential to confine particles without a physical boundary. We show that, in the absence of a curved wall, near perfect hexagonal ordering is possible. We propose that the degree to which hexagonal ordering is suppressed by a curved boundary is determined by the `strictness' of that wall.Comment: 10 pages, 8 figure

Compliance with Hygiene Recommendations for Human-animal Contact at Petting Zoos

Background: Most children at petting zoos are at least somewhat naïve with respect to animal contact, which is probably why they are being taken to a petting zoo. Unfortunately, their immune systems may be equally naïve, thereby putting these children at high risk of contracting one of several enteric zoonotic diseases. A cross-sectional study was conducted to determine public and organizational compliance with current recommendations for hygiene and public safety for human-animal contact at permanent and temporary petting zoos. Methods: A single investigator visited 17 petting zoos across Michigan to evaluate both facilityrelated and visitor-related risk factors for zoonotic enteric disease transmission. We observed 246 children at 6 permanent Michigan petting zoos and 11 temporary Michigan petting zoos associated with agricultural fairs. No contact was made with any petting zoo visitors, and factors such as age and gender were subjectively accessed by visual observation. Results: Permanent zoos were more likely to have signs regarding hand hygiene and sanitizing facilities than did temporary or “traveling” petting zoos. Zoo personnel reminded 1.2% of visitors to wash their hands, and less than a third of all children were observed to have washed their hands following animal contact. Of the 246 children observed, about 50% (122) touched their own face, eyes, nose or mouth and 42% (104) touched the animals’ mouth. In addition, one child was seen ingesting goat feces, three were seen drinking out of the animals’ water trough, and one child was seen sucking on a fence rail; all in the presence of exhibit personnel who did not intervene. No association was observed between rates of hand washing and the degree of parental supervision. Conclusions: We concluded that the current CDC hygiene recommendations for visits to petting zoos are generally not being followed by visitors or by exhibitors. Most parental and exhibitor supervision appeared to be focused on preventing physical trauma to the animals and to the children. Further educational outreach and/or regulation may be indicated to prevent enteric disease transmission from animal contact at petting zoos. However, it may be difficult for young children to understand that animal contact is safe and desirable only if proper hygiene practices are followed

Naval Force Planning Cases: Organizing Our Thoughts and Weighing Alternatives

At the highest level, a nation\u27s grand strategy influences its choice of naval forces. So, in turn, do military and maritime strategies. Each supports the higher order strategy while providing further insight into specific forces required

Strategy as a Guide to Force Planning

Is there a method to Pentagon madness? That is the question so often asked about defense planning by Congressional and journalistic critics. Between the extremes of throwing money at the problem and indiscriminate cuts, is there a better approach to force planning

Case-Control Study of Risk Factors Associated with Feline and Canine Chronic Kidney Disease

An age-matched case-control study was initiated to determine the major risk factors associated with CKD in cats and dogs and to determine what clinical signs cat and dog owners observed before their veterinarian diagnosed their pet with CKD. When compared to controls, the feline cases were more likely to have had polydipsia and polyuria in the year before the owners' cats were diagnosed with CKD. In the dogs, increased water intake, increased urination, small size and a recent history of weight loss and bad breath were noticed by the dog owners before veterinary CKD diagnosis. Dog owners recognized abnormal drinking and urination behavior over half a year before their pet's veterinary diagnosis with CKD, and they recognized weight loss almost 4 months before CKD diagnosis. Bad breath was noticed 1.2 years before recognition of CKD by a veterinarian. Given that earlier CKD diagnosis should have been possible in most cases, clinical trials should proceed to measure the efficacy of early interventions

Requirements for Robotic Interpretation of Social Signals “in the Wild”: Insights from Diagnostic Criteria of Autism Spectrum Disorder

The last few decades have seen widespread advances in technological means to characterise observable aspects of human behaviour such as gaze or posture. Among others, these developments have also led to significant advances in social robotics. At the same time, however, social robots are still largely evaluated in idealised or laboratory conditions, and it remains unclear whether the technological progress is sufficient to let such robots move “into the wild”. In this paper, we characterise the problems that a social robot in the real world may face, and review the technological state of the art in terms of addressing these. We do this by considering what it would entail to automate the diagnosis of Autism Spectrum Disorder (ASD). Just as for social robotics, ASD diagnosis fundamentally requires the ability to characterise human behaviour from observable aspects. However, therapists provide clear criteria regarding what to look for. As such, ASD diagnosis is a situation that is both relevant to real-world social robotics and comes with clear metrics. Overall, we demonstrate that even with relatively clear therapist-provided criteria and current technological progress, the need to interpret covert behaviour cannot yet be fully addressed. Our discussions have clear implications for ASD diagnosis, but also for social robotics more generally. For ASD diagnosis, we provide a classification of criteria based on whether or not they depend on covert information and highlight present-day possibilities for supporting therapists in diagnosis through technological means. For social robotics, we highlight the fundamental role of covert behaviour, show that the current state-of-the-art is unable to characterise this, and emphasise that future research should tackle this explicitly in realistic settings