Do Two Symmetry Breaking Transitions in Photosynthetic Light Harvesting Complexes Form One, Two or More Kibble Zurek Model Topological Defects?

Kibble and Zurek proposed that rapid symmetry breaking transitions in the hot, early universe could result in causally disconnected topological defects such as cosmic strings. This type of first order transition has analogues in certain second order transitions present in condensed matter such as liquid crystals, super fluids, and charge density waves in terms of flux tubes or vortices. Recently, we discovered that Rhodopseudomonas acidophilus photosynthetic light harvesting complex might have different types of coherent ground and excited states, suggesting that there are two different symmetry breaking transitions. The B 850 ground states comprise eight identical rings each containing 18 bacteriochlorophyll components, and each ring has undergone a Bose Einstein phase transition to a charge density wave that lowers the energy. The excited state coherence results from polariton formation from the non-crossing of bosons, here an extension of exciton theory. The result is short-lived quasi-particles with very low mass that can form an unusual BEC. We suggest the oriented, circular B 850 and enclosed singlet B 875 compounds create a new cavity structure with some attributes of a nano pillar. Since both the ground and excited states should contain solitons, we envisage three fast light pulse experiments could be able to map both the Kibble Zurek Model phase transitions and energy transfers as a function of light intensity and time in this complex at room temperature

A Conserved Cysteine Motif Is Critical for Rice Ceramide Kinase Activity and Function

Ceramide kinase (CERK) is a key regulator of cell survival in dicotyledonous plants and animals. Much less is known about the roles of CERK and ceramides in mediating cellular processes in monocot plants. Here, we report the characterization of a ceramide kinase, OsCERK, from rice (Oryza sativa spp. Japonica cv. Nipponbare) and investigate the effects of ceramides on rice cell viability.OsCERK can complement the Arabidopsis CERK mutant acd5. Recombinant OsCERK has ceramide kinase activity with Michaelis-Menten kinetics and optimal activity at 7.0 pH and 40°C. Mg2+ activates OsCERK in a concentration-dependent manner. Importantly, a CXXXCXXC motif, conserved in all ceramide kinases and important for the activity of the human enzyme, is critical for OsCERK enzyme activity and in planta function. In a rice protoplast system, inhibition of CERK leads to cell death and the ratio of added ceramide and ceramide-1-phosphate, CERK's substrate and product, respectively, influences cell survival. Ceramide-induced rice cell death has apoptotic features and is an active process that requires both de novo protein synthesis and phosphorylation, respectively. Finally, mitochondria membrane potential loss previously associated with ceramide-induced cell death in Arabidopsis was also found in rice, but it occurred with different timing.OsCERK is a bona fide ceramide kinase with a functionally and evolutionarily conserved Cys-rich motif that plays an important role in modulating cell fate in plants. The vital function of the conserved motif in both human and rice CERKs suggests that the biochemical mechanism of CERKs is similar in animals and plants. Furthermore, ceramides induce cell death with similar features in monocot and dicot plants

Public health response to two imported, epidemiologically related cases of Lassa fever in the Netherlands (ex Sierra Leone), November 2019

On 20 November 2019, Lassa fever was diagnosed in a physician repatriated from Sierra Leone to the Netherlands. A second physician with suspected Lassa fever, repatriated a few days later from the same healthcare facility, was confirmed infected with Lassa virus on 21 November. Comprehensive contact monitoring involving high- and low-risk contacts proved to be feasible and follow-up of the contacts did not reveal any case of secondary transmission in the Netherlands.Medical Microbiolog

Mpox outbreak in the Netherlands, 2022: public health response, characteristics of the first 1,000 cases and protection of the first-generation smallpox vaccine

In early May 2022, a global outbreak of mpox started among persons without travel history to regions known to be enzootic for monkeypox virus (MPXV). On 8 August 2022, the Netherlands reported its 1,000th mpox case, representing a cumulative incidence of 55 per million population, one of the highest cumulative incidences worldwide. We describe characteristics of the first 1,000 mpox cases in the Netherlands, reported between 20 May and 8 August 2022, within the context of the public health response. These cases were pre-dominantly men who have sex with men aged 31-45 years. The vast majority of infections were acquired through sexual contact with casual partners in pri-vate or recreational settings including LGBTQIA+ ven-ues in the Netherlands. This indicates that, although some larger upsurges occurred from point-source and/or travel-related events, the outbreak was mainly characterised by sustained transmission within the Netherlands. In addition, we estimated the protective effect of first-generation smallpox vaccine against moderate/severe mpox and found a vaccine effective-ness of 58% (95% CI: 17-78%), suggesting moderate protection against moderate/severe mpox symptoms on top of any possible protection by this vaccine against MPXV infection and disease. Communication with and supporting the at-risk population in following mitigation measures remains essential.Immunogenetics and cellular immunology of bacterial infectious disease

Outbreak of diarrhoea among participants of a triathlon and a duathlon on 12 July 2015 in Utrecht, the Netherlands.

On 12 July 2015, a triathlon competition with 900 participants took place in Utrecht, the Netherlands. An outbreak investigation was initiated after 56 participants reported health complaints. An online questionnaire was sent to 700 participants. Stool specimens from six participants and four water specimens were collected from the swimming location. A total of 239 participants completed the questionnaire (response rate: 34%), 73 (31%) of them met the case definition for acute gastrointestinal illness (AGI). A total of 67% of the respondents were male and the median age was 38 years. Almost half (42%) of swimmers reported health complaints. Consumption of energy drinks and ingesting ⩾3 mouthfuls of canal water were identified as risk factors for AGI among swimmers only (adjusted relative risks (aRR) 1·6; 95% confidence intervals (CI) 1·0-2·5 and aRR 2·6; 95% CI 1·5-4·8). The collected water specimens tested positive for norovirus genogroup I and rotavirus and stool specimens tested positive for norovirus genogroup II. Our findings indicate that the outbreak could have been caused by exposure to norovirus during swimming. Swimmers should get information about the health risks for making an informed choice about participating. For future events, the organisers decided to change the swimming location from a canal to a recreational lake