Modification of kraft wood-pulp fibre with silica for surface functionalisation

A new science strategy for natural fibre modification was devised in which glass surface properties would be imparted to wood-derived fibre. The enhancements known from addition of silane reagents to glass fibre–polymer composites could therefore be realised for modified cellulose fibre–polymer composites. A process is described whereby the internal void spaces and micropores of never-dried Kraft pulp fibre walls were impregnated with silica. This was achieved by initial dehydration of never-dried fibre through azeotropic distillation to achieve substitution of fibre water with the silicon chemical solution over a range of concentrations. Kraft fibres were stiffened and made resistant to collapse from the effect of the azeotrope drying. Specific chemical reaction of azeotrope-dried fibre with the reagent ClSi(OEt)3 followed by base-catalysed hydrolysis of the ester groups formed a fibre-bound silica composite. The physico-chemical substitution of water from micropores and internal voids of never-dried fibre with property-modifying chemicals offers possibilities in the development of new fibre characteristics, including fibres which may be hardened, plasticised, and/or stabilised against moisture, biodegradation or fire. The embedded silica may also be used as sites of attachment for coupling agents to modify the hydrophilic character of the fibre or to functionalise the fibre surface

Deficient Response to COVID-19 Makes the Case for Evolving the Public Health System

Coronavirus disease 2019 (COVID-19) has affected more than 14 million individuals and caused more than 600,000 deaths as of July 20, 2020, rapidly spreading across large cities as well as many rural areas. In parallel with rising cases and deaths globally, the situation in local communities fluctuates daily while knowledge about the disease and transmission evolves. Public health agencies play a critical role in managing disease epidemics. Agencies are on the front lines to conduct disease surveillance, facilitate resource distribution including personal protective equipment (PPE), establish alternative care sites, and provide diagnostic support through laboratory testing. The public health response to COVID-19 has been criticized for being too slow, lacking transparency, and insufficient. This essay examines reasons behind the sluggish response to COVID-19. The authors then argue for an evolved public health system following the crisis, which is better prepared for emergencies and equipped to support population health for the future

Distributing Attorney Fees in Multidistrict Litigation

As consolidated multidistrict litigation has come to dominate the federal civil docket, the problem of how to divide attorney fees among participating firms has become the source of frequent and protracted litigation. For example, in the National Football League (NFL) Concussion Litigation, the judge awarded the plaintiff attorneys over $100 million in fees, but the division of those fees among the twenty-six firms involved sparked two additional years of litigation. We explore solutions to this fee division problem, drawing insights from the economics, game theory, and industrial organization literatures. Ultimately, we propose a novel division method based on peer reports. Participating firms assess the relative contribution of other firms to the litigation, and then optimization or Bayesian techniques arrive at a consensus or compromise fee allocation. Our methods are intuitively easy to understand, enable broad participation, and are resistant to collusion or other strategic behavior, making them likely to be accepted by the firms involved. We thus provide courts with an important mediation tool or decision rule for these fee division disputes

Enhancement and Suppression of Ultradian and Circadian Rhythms Across the Female Hamster Reproductive Cycle

The impact of ovarian hormones on hamster ultradian rhythms (URs) is unknown. We concurrently monitored URs and circadian rhythms (CRs) of home cage locomotor activity during the estrous cycle, pregnancy, and lactation of Syrian hamsters. URs with a mean period of 4–5 h were evident during the dark phase in more than 90% of females on days 1 and 2 of the estrous cycle but were significantly less prevalent on cycle days 3 and 4. The period of the UR did not vary as a function of estrous cycle stage, but at all stages, the UR period was longer in the dark than the light phase. The UR acrophase occurred significantly earlier on cycle day 4 than on days 1 and 2, and UR robustness and amplitude were reduced on days 3 and 4. Robustness, mesor, and amplitude of CRs were greater during cycle days 3 and 4; timing of the CR acrophase was delayed on day 4 relative to all other cycle days. Effects of the estrous cycle on URs were evident only during the dark phase. The proportion of hamsters displaying dark phase URs increased significantly during early and late gestation and decreased during lactation. Pregnancy significantly increased UR complexity, robustness, and amplitude. The emergence of URs over gestation was paralleled by decrements in the robustness and amplitude of CRs, which also were absent in a significant proportion of dams during lactation but re-emerged at weaning of litters. The changing endocrine profile of the estrous cycle, hormonal dynamics of pregnancy and lactation, and nursing demands placed on dams are each associated with alterations in the expression of ultradian and circadian locomotor rhythms. Diminution of CRs and augmentation of URs may afford greater behavioral flexibility during life stages when interactions with mates and offspring are less predictable