Iron-binding fragments from the N-Terminal and C-Terminal regions of human lactoferrin

Digestion of lactoferrin with pepsin at pH 3.0 gave an iron-binding half-molecule that represents the C-terminal part of the native protein. Tryptic or chymotryptic digestion of 30%/-iron-saturated lactoferrin yielded the N- and C-terminal half molecules, which could be separated by DEAE-Sephadex chromatography. The N- and C-terminal fragments did not show any immunological cross-reaction. The carbohydrate of lactoferrin was distributed equally between the two fragments

Teleost antibody structure: Simple prototype or elegant alternative?

Teleosts possess mechanism(s) by which they can generate considerable structural diversity within their tetrameric antibody molecules. In salmonids, this diversity is generated through a process of random polymerisation of the constituent monomeric subunits rather than dependency upon isotypic gene diversity. Thus, one gene product can give rise to as many as six different structural forms of immunoglobulin. In contrast to mammals, evidence suggests that this polymerisation process occurs late in the secretory process and not within the endoplasmic reticulum. This assembly process is likely to be important in the generation of teleost antibody functional diversity, thereby potentially simulating isotypy

Zirconium molybdate gel as a generator for technetium-99m.

A new (99m)Tc generator based on zirconium molybdate gel is described. Essentially the gel is a cation ion exchanger which permits the elution of the pertechnetate ion. The high molybdenum content of this gel its stability under self-irradiation and the absence of organic materials during preparation provide a generator concept that eliminates high processing costs active waste storage costs and stability problems in other types of generator

Quantifying the contribution of pathways of nosocomial acquisition of COVID-19 in English hospitals

BACKGROUND: Despite evidence of the nosocomial transmission of novel coronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in hospitals worldwide, the contributions of the pathways of transmission are poorly quantified. METHODS: We analysed national records of hospital admissions and discharges, linked to data on SARS-CoV-2 testing, using an individual-based model that considers patient-to-patient, patient-to-healthcare worker (HCW), HCW-to-patient and HCW-to-HCW transmission. RESULTS: Between 1 March 2020 and 31 December 2020, SARS-CoV-2 infections that were classified as nosocomial were identified in 0.5% (0.34-0.74) of patients admitted to an acute National Health Service trust. We found that the most likely route of nosocomial transmission to patients was indirect transmission from other infected patients, e.g. through HCWs acting as vectors or contaminated fomites, followed by direct transmission between patients in the same bay. The risk of transmission to patients from HCWs over this time period is low, but can contribute significantly when the number of infected inpatients is low. Further, the risk of a HCW acquiring SARS-CoV-2 in hospital is approximately equal to that in the community, thereby doubling their overall risk of infection. The most likely route of transmission to HCWs is transmission from other infected HCWs. CONCLUSIONS: Current control strategies have successfully reduced the transmission of SARS-CoV-2 between patients and HCWs. In order to reduce the burden of nosocomial COVID-19 infections on health services, stricter measures should be enforced that would inhibit the spread of the virus between bays or wards in the hospital. There should also be a focus on inhibiting the spread of SARS-CoV-2 between HCWs. The findings have important implications for infection-control procedures in hospitals

Prevalence of, and risk factors for, HIV, hepatitis B and C infections among men who inject image and performance enhancing drugs: a cross-sectional study

Objective: To describe drug use, sexual risks and the prevalence of blood-borne viral infections among men who inject image and performance enhancing drugs (IPEDs). Design: A voluntary unlinked-anonymous crosssectional biobehavioural survey. Setting: 19 needle and syringe programmes across England and Wales. Participants: 395 men who had injected IPEDs. Results: Of the participants (median age 28 years), 36% had used IPEDs for <5 years. Anabolic steroids (86%), growth hormone (32%) and human chorionic gonadotropin (16%) were most frequently injected, with 88% injecting intramuscularly and 39% subcutaneously. Two-thirds also used IPEDs orally. Recent psychoactive drug use was common (46% cocaine, 12% amphetamine), 5% had ever injected a psychoactive drug and 9% had shared injecting equipment. ‘Viagra/Cialis’ was used by 7%, with 89% reporting anal/vaginal sex in the preceding year (20% had 5+ female-partners, 3% male-partners) and 13% always using condoms. Overall, 1.5% had HIV, 9% had antibodies to the hepatitis B core antigen (anti-HBc) and 5% to hepatitis C (anti-HCV). In multivariate analysis, having HIV was associated with: seeking advice from a sexual health clinic; having had an injection site abscess/wound; and having male partners. After excluding those reporting male partners or injecting psychoactive drugs, 0.8% had HIV, 8% anti-HBc and 5% anti-HCV. Only 23% reported uptake of the hepatitis B vaccine, and diagnostic testing uptake was poor (31% for HIV, 22% for hepatitis C). Conclusions: Previous prevalence studies had not found HIV among IPED injectors. HIV prevalence in this, the largest study of blood-borne viruses among IPED injectors, was similar to that among injectors of psychoactive drugs. Findings indicate a need for targeted interventions

Diel turbidity cycles in a headwater stream: evidence of nocturnal bioturbation?

Purpose: A small number of recent studies have linked daily cycles in stream turbidity to nocturnal bioturbation by aquatic fauna, principally crayfish, and demonstrated this process can significantly impact upon water quality under baseflow conditions. Adding to this limited body of research, we use high-resolution water quality monitoring data to investigate evidence of diel turbidity cycles in a lowland, headwater stream with a known signal crayfish (Pacifastacus leniusculus) population and explore a range of potential causal mechanisms. Materials and methods: Automatic bankside monitoring stations measured turbidity and other water quality parameters at 30-min resolution at three locations on the River Blackwater, Norfolk, UK during 2013. Specifically, we focused on two 20-day periods of baseflow conditions during January and April 2013 which displayed turbidity trends typical of winter and spring seasons, respectively. The turbidity time-series, which were smoothed with 6.5 hour Savitzky-Golay filters to highlight diel trends, were correlated against temperature, stage, dissolved oxygen and pH to assess the importance of abiotic influences on turbidity. Turbidity was also calibrated against suspended particulate matter (SPM) over a wide range of values via linear regression. Results and discussion: Pronounced diel turbidity cycles were found at two of the three sites under baseflow conditions during April. Spring night-time turbidity values consistently peaked between 21:00 and 04:00 with values increasing by ~10 nephelometric turbidity units (NTU) compared with the lowest recorded daytime values which occurred between 10:00 and 14:00. This translated into statistically significant increases in median midnight SPM concentration of up to 76% compared with midday, with night-time (18:00 – 05:30) SPM loads also up to 30% higher than that recorded during the daytime (06:00 – 17:30). Relating turbidity to other water quality parameters exhibiting diel cycles revealed there to be neither any correlation that might indicate a causal link, nor any obvious mechanistic connections to explain the temporal turbidity trends. Diel turbidity cycles were less prominent at all sites during the winter. Conclusions: Considering the seasonality and timing of elevated turbidity, visual observations of crayfish activity, and an absence of mechanistic connections with other water quality parameters, the results presented here are consistent with the hypothesis that nocturnal bioturbation is responsible for generating diel turbidity cycles under baseflow conditions in headwater streams. However, further research in a variety of fluvial environments is required to better assess the spatial extent, importance and causal mechanisms of this phenomenon

Susceptibility to Peer Pressure, Self-Esteem, and Health Locus of Control as Correlates of Adolescent Substance Abuse

As part of a school-based alcohol misuse prevention study, questionnaires were ad ministered to 2,589 fifth and sixth grade students to determine levels of use of alcohol, marijuana, and cigarettes, intentions to use these substances, and problems resulting from alcohol misuse. The questionnaire also included 45 items concerning susceptibil ity to peer pressure, self-esteem, and health locus of control. These 45 items were factor analyzed separately for two groups formed by random assignment. Six factors were identified which were both internally consistent and replicable, and indices were constructed. The indices measuring susceptibility to peer pressure, self-esteem, and internal health locus of control were significantly and negatively correlated with most of the substance use, misuse, and intention items, and an external health locus of con trol index was not significantly related to most of the substance use, misuse, and inten tion items. The "Susceptibility to Peer Pressure" index correlated more highly with the adolescent substance use, misuse, and intention items than the self-esteem or the health locus of control indices, and it had the highest alpha coefficient. Implications for the design of school-based substance abuse prevention programs are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68065/2/10.1177_109019818701400207.pd

Pursuit-Evasion Games and Zero-sum Two-person Differential Games

International audienceDifferential games arose from the investigation, by Rufus Isaacs in the 50's, of pursuit-evasion problems. In these problems, closed-loop strategies are of the essence, although defining what is exactly meant by this phrase, and what is the Value of a differential game, is difficult. For closed-loop strategies, there is no such thing as a " two-sided Maximum Principle " , and one must resort to the analysis of Isaacs' equation, a Hamilton Jacobi equation. The concept of viscosity solutions of Hamilton-Jacobi equations has helped solve several of these issues

Proteomics: in pursuit of effective traumatic brain injury therapeutics

Effective traumatic brain injury (TBI) therapeutics remain stubbornly elusive. Efforts in the field have been challenged by the heterogeneity of clinical TBI, with greater complexity among underlying molecular phenotypes than initially conceived. Future research must confront the multitude of factors comprising this heterogeneity, representing a big data challenge befitting the coming informatics age. Proteomics is poised to serve a central role in prescriptive therapeutic development, as it offers an efficient endpoint within which to assess post-TBI biochemistry. We examine rationale for multifactor TBI proteomic studies and the particular importance of temporal profiling in defining biochemical sequences and guiding therapeutic development. Lastly, we offer perspective on repurposing biofluid proteomics to develop theragnostic assays with which to prescribe, monitor and assess pharmaceutics for improved translation and outcome for TBI patients

Second law, entropy production, and reversibility in thermodynamics of information

We present a pedagogical review of the fundamental concepts in thermodynamics of information, by focusing on the second law of thermodynamics and the entropy production. Especially, we discuss the relationship among thermodynamic reversibility, logical reversibility, and heat emission in the context of the Landauer principle and clarify that these three concepts are fundamentally distinct to each other. We also discuss thermodynamics of measurement and feedback control by Maxwell's demon. We clarify that the demon and the second law are indeed consistent in the measurement and the feedback processes individually, by including the mutual information to the entropy production.Comment: 43 pages, 10 figures. As a chapter of: G. Snider et al. (eds.), "Energy Limits in Computation: A Review of Landauer's Principle, Theory and Experiments