100th Anniversary of Macromolecular Science Viewpoint: Opportunities in the Physics of Sequence-Defined Polymers

Polymer science has been driven by ever-increasing molecular complexity, as polymer synthesis expands an already-vast palette of chemical and architectural parameter space. Copolymers represent a key example, where simple homopolymers have given rise to random, alternating, gradient, and block copolymers. Polymer physics has provided the insight needed to explore this monomer sequence parameter space. The future of polymer science, however, must contend with further increases in monomer precision, as this class of macromolecules moves ever closer to the sequence-monodisperse polymers that are the workhorses of biology. The advent of sequence-defined polymers gives rise to opportunities for material design, with increasing levels of chemical information being incorporated into long-chain molecules; however, this also raises questions that polymer physics must address. What properties uniquely emerge from sequence-definition? Is this circumstance-dependent? How do we define and think about sequence dispersity? How do we think about a hierarchy of sequence effects? Are more sophisticated characterization methods, as well as theoretical and computational tools, needed to understand this class of macromolecules? The answers to these questions touch on many difficult scientific challenges, setting the stage for a rich future for sequence-defined polymers in polymer physics

Recent Advances in Encapsulation, Protection, and Oral Delivery of Bioactive Proteins and Peptides using Colloidal Systems

There are many areas in medicine and industry where it would be advantageous to orally deliver bioactive proteins and peptides (BPPs), including ACE inhibitors, antimicrobials, antioxidants, hormones, enzymes, and vaccines. A major challenge in this area is that many BPPs degrade during storage of the product or during passage through the human gut, thereby losing their activity. Moreover, many BPPs have undesirable taste profiles (such as bitterness or astringency), which makes them unpleasant to consume. These challenges can often be overcome by encapsulating them within colloidal particles that protect them from any adverse conditions in their environment, but then release them at the desired site-of-action, which may be inside the gut or body. This article begins with a discussion of BPP characteristics and the hurdles involved in their delivery. It then highlights the characteristics of colloidal particles that can be manipulated to create effective BPP-delivery systems, including particle composition, size, and interfacial properties. The factors impacting the functional performance of colloidal delivery systems are then highlighted, including their loading capacity, encapsulation efficiency, protective properties, retention/release properties, and stability. Different kinds of colloidal delivery systems suitable for encapsulation of BPPs are then reviewed, such as microemulsions, emulsions, solid lipid particles, liposomes, and microgels. Finally, some examples of the use of colloidal delivery systems for delivery of specific BPPs are given, including hormones, enzymes, vaccines, antimicrobials, and ACE inhibitors. An emphasis is on the development of food-grade colloidal delivery systems, which could be used in functional or medical food applications. The knowledge presented should facilitate the design of more effective vehicles for the oral delivery of bioactive proteins and peptides

Recent progress in the science of complex coacervation

Complex coacervation is an associative, liquid–liquid phase separation that can occur in solutions of oppositely-charged macromolecular species, such as proteins, polymers, and colloids. This process results in a coacervate phase, which is a dense mix of the oppositely-charged components, and a supernatant phase, which is primarily devoid of these same species. First observed almost a century ago, coacervates have since found relevance in a wide range of applications; they are used in personal care and food products, cutting edge biotechnology, and as a motif for materials design and self-assembly. There has recently been a renaissance in our understanding of this important class of material phenomena, bringing the science of coacervation to the forefront of polymer and colloid science, biophysics, and industrial materials design. In this review, we describe the emergence of a number of these new research directions, specifically in the context of polymer–polymer complex coacervates, which are inspired by a number of key physical and chemical insights and driven by a diverse range of experimental, theoretical, and computational approaches

Knowledge management and organizational culture

This paper explores the relationship between organisational knowledge, organisational culture, and Process Based Systems (PBS), in the U.K. National Health Service (NHS). Links between PBS and organisational culture have been observed before(Perry, 2003); the contribution made by PBS to organisational knowledge has also been suggested (Perry, 2004). However, links between organisational knowledge and organisational culture in the NHS have not been widely studied. A qualitative study of these links across clinical functions has been used in conjunction with a literature review to consider in particular the use of tacit knowledge and the role that might be played by PBS in mediating and sharing this "embedded" or experiential form of knowledge. While there may be some opportunity for "externalisation" (Nonaka, 1994) - the conversion of tacit to explicit knowledge, this paper argues that PBS may also contribute to "socialisation" - the direct generation of tacit knowledge by tacit knowledge.Process Based Systems, knowledge management, organisational culture

Neurosyphilis presenting with papillitis

Syphilis is one of the oldest described infectious diseases in the world and is caused by the spirochete bacterium Treponema pallidum[1]. Although now a rare disease, incidence is increasing with the number of diagnoses of the disease rising in England from 1688 to 2713 between 2003 and 2012 (a 61% increase)[2]. Major outbreaks of syphilis have been documented in London, Manchester, Dublin, and Brighton particularly among men who have sex with men (MSM)[3]. Diagnosis remains difficult on account of multi-system symptoms, duration of the condition, and social stigma

Fascia Thickness and Mechanical Demand at the Ankle Joint during Dance Jumps in Classically Trained Ballet Dancers

Ballet is an athletic activity that combines aesthetics and artistry with power and ­­­­­skill. One of the most athletic aspects of dance is observed during jumps. Many jumps in ballet involve takeoff from a single leg, but differ in propulsion direction. To assess differences in mechanical demand, two single leg jumps commonly trained in ballet were compared; a saut de chat (SDC) and a temp levé from a step (SLSJ). Fifteen female classically trained dancers with similar number of years of training (13.9 ± 5.0 years) were instrumented with lower body reflective markers and performed each jump three times on a force plate. The marker position data and ground reaction forces (GRF) were captured synchronously at 250 hz and 100 hz, respectively, using a Vicon motion capture system. Peak vertical GRF, average rate of force development (RFD), peak ankle moment and peak ankle power were measured and averaged across trials. Paired t-tests were used to determine differences between the SDC and the SLSJ. When compared to the SLSJ, the SDC displayed significantly higher peak vertical GRF (p = .003), RFD (p = .002), and peak ankle moment and power (p \u3c .001). Analysis of effect size for these differences revealed a large effect size for all variables (Cohen’s d \u3e .80). In conclusion, results of this study indicate the mechanical demand of different dance jumps is diverse, which has implications for performance enhancement, injury prevention, and rehabilitation

Microbial biomass, soil ammonium and nitrate in a 69-year secondary successional Populus grandidentata chronosequence.

General EcologyOver the last two hundred years, logging and fire have caused significant changes in the landscape of northern Lower Michigan. Nutrient cycling is impacted as these disturbances affect the forest ecosystem, causing secondary succession. Soil microbes perform the important function of nitrogen nitrification and mineralization, which causes variation in the amount of ammonium and nitrate available in the soil. The trends in microbial and amino N biomass, nitrate, and ammonium levels across secondary successional chronosequences are currently not well understood. We collected "A" horizon soil samples from three Populus grandidentata forests of varying secondary successional ages. We performed a potassium sulfate (K2S04) extraction on chloroform-fumigated and non-fumigated soil samples. Then, we ran a ninhydrin assay on the extractions to determine soil ammonium, nitrate, microbial N biomass, and amino N biomass levels in the soil. Total microbial N, NH4+, and N03- are significantly larger in the 104- year-old bum plot (Microbial N (F,39, p=.863), NH: (Fv., p=<.000), NO, (Fv., p=.003)). There is not a significant difference in amino N mass between the three stands (F,.39, p=.273). There is a positive relationship between amino N mass and NH4+ mass (R2=0.365, P<0.000, 95% Confidence Level). Lastly, there is not a significant relationship between Amino N mass and nitrate mass (R2=0.081, P<0.061, 95% Confidence Level). Total nitrogen content in the soil is higher in later-successional forest stands, and microbial biomass does not account for large changes in soil nitrate. Higher microbial biomass indicates higher ammonium content in the soil. These results are significant because nitrogen in the soil affects forest productivity, an ecosystem service we need to perform carbon sequestration and emitting of oxygen.http://deepblue.lib.umich.edu/bitstream/2027.42/116855/1/Perry_Sarah_2015.pd

Enough Is Enough: Pre Se Constructive Discharge for Victims of Sexually Hostile Work Environments under Title VII

In Title VII sexual harassment cases based on hostile work environments, application of the constructive discharge doctrine imposes unfair burdens on claimants. A finding of constructive discharge requires a greater severity or pervasiveness of harassment than that required for finding a hostile work environment. This forces many hostile environment victims to remain in abusive and intolerable conditions because they cannot afford to resign. Unless found constructively discharged by their employers, victims who quit their jobs cannot recover back pay for the period between resignation and judgment. The incorrect and inconsistent application of the constructive discharge doctrine in sexually hostile environment cases causes this result. A per se rule that necessitates finding a constructive discharge when a sexually hostile work environment is found provides a uniform and fair solution to the problem

Coming Home: Challenges Related to Reentry and Recidivism for Previously Incarcerated New Mothers

This thesis explores the intersection of motherhood, recidivism, and the reentry process for recently incarcerated new mothers. Women were recruited from the Healthy Beginnings Project, a program that works with pregnant, incarcerated women from correctional institutions in the Williamsburg area to provide perinatal education and support. Completed intake and postpartum surveys (n=103) were analyzed for quantitative data on the incremental ability of maternal, psychological, and contextual stressors to predict new mothers\u27 likelihood to recidivate. 34.3% (n=34) of the new mothers recidivated when the child was one to twelve months old. None of the summed stressor variables were significantly associated with recidivism, nor was the cumulative measure of combined stressors. However, some of the individual contextual variables were: monetary stress (t(94)=-2.04, p=0.04), unemployment (x2=10.53, px2=15.94, pn=15) collected narratives on the women’s experiences related to incarceration, motherhood, and reentry. Women who recidivated (n=6) did not attribute their reincarceration to their children, but women who were successful in their reentry (n=9) attributed their success to their children