Solitonic lattice and Yukawa forces in the rare earth orthoferrite TbFeO3

The control of domains in ferroic devices lies at the heart of their potential for technological applications. Multiferroic materials offer another level of complexity as domains can be either or both of a ferroelectric and magnetic nature. Here we report the discovery of a novel magnetic state in the orthoferrite TbFeO3 using neutron diffraction under an applied magnetic field. This state has a very long incommensurate period ranging from 340 Angstrom at 3K to 2700 Angstrom at the lowest temperatures and exhibits an anomalously large number of higher-order harmonics, allowing us to identify it with the periodic array of sharp domain walls of Tb spins separated by many lattice constants. The Tb domain walls interact by exchanging spin waves propagating through the Fe magnetic sublattice. The resulting Yukawa-like force, familiar from particle physics, has a finite range that determines the period of the incommensurate state.Comment: 11 pages 14 figure

Evaluation of the causal effects between dopamine infusion changeover and fluctuations in mean arterial pressure in neonates

Objective To evaluate whether changing dopamine infusions every 12 hours and preparing these infusions 30 min before administration reduces blood pressure fluctuations in preterm and term neonates. Design This was a retrospective study using data from live patients on the neonatal unit and prospective study exploring stability of infusions in a laboratory-based neonatal ward simulation. Setting Single-centre study in a tertiary neonatal surgical unit in a university teaching hospital. Patients Neonates who received more than one subsequent dopamine infusion and had invasive arterial blood pressure monitoring, during their admission in the neonatal unit, were included. Interventions As part of the Quality Improvement project, the standard operating procedure (SOP) was changed, and dopamine infusions were prepared by nursing staff and left to rest for 30 min before administering to the neonate. Additionally, infusions were replaced every 12 hours. Main outcome measures The percentage change in mean arterial pressure (MAP) and the percentage loss in the drug concentration during infusion during changeover. Results Our findings indicate that up to 15% of the initial dopamine concentration is lost after 24 hours. This results in a sharp variation in the dopamine concentration during infusion changeover that correlates with observed rapid fluctuations in MAP. In changing the SOP, no significant difference in the concentration of dopamine and MAP were observed over 12 hours. Conclusions Delaying administration of dopamine infusions by 30 min after preparation combined with changing infusions 12 hourly has reduced MAP fluctuations. Therefore, the risks associated with MAP fluctuations, including intraventricular haemorrhages, are reduced

Neat Protein Single-Chain Nanoparticles from Partially Denatured BSA

The main challenge for the preparation of protein single-chain nanoparticles (SCNPs) is the natural complexity of these macromolecules. Herein, we report the suitable conditions to produce "neat" bovine serum albumin (BSA) single-chain nanoparticles (SCNPs) from partially denatured BSA, which involves denaturation in urea and intramolecular cross-linking below the overlap concentration. We use two disuccinimide ester linkers containing three and six methylene spacer groups: disuccinimidyl glutarate (DSG) and disuccinimidyl suberate (DSS), respectively. Remarkably, the degree of internal cross-linking can be followed simply and efficiently via 1H NMR spectroscopy. The associated structural changes-as probed by small-angle neutron scattering (SANS)-reveal that the denatured protein has a random-like coil conformation, which progressively shrinks with the addition of DSG or DSS, thus allowing for size control of the BSA-SCNPs with radii of gyration down to 5.4 nm. The longer cross-linker exhibits slightly more efficiency in chain compaction with a somewhat stronger size reduction but similar reactivity at a given cross-linker concentration. This reliable method is applicable to a wide range of compact proteins since most proteins have appropriate reactive amino acids and denature in urea. Critically, this work paves the way to the synthesis of "neat", biodegradable protein SCNPs for a range of applications including nanomedicine.The authors acknowledge the financial support received from the IKUR Strategy under the collaboration agreement between the Ikerbasque Foundation and the Materials Physics Center on behalf of the Department of Education of the Basque Government. Financial support by MCIN/AEI/10.13039/501100011033 and “ERDF – A way of making Europe” (grant PID2021-123438NB-I00), Eusko Jaurlaritza – Basque Government (grant IT-1566-22) and the Gipuzkoako Foru Aldundia, Programa Red Gipuzkoana de Ciencia, Tecnología e Innovación (2021-CIEN-000010-01) is gratefully acknowledged. A.I. thanks MICINN for a Personal Técnico de Apoyo contract (PTA2017-14359-I)

Exfoliative Toxins of Staphylococcus aureus

Virulent strains of Staphylococcus aureus secrete exfoliative toxins (ETs) that cause the loss of cell‐cell adhesion in the superficial epidermis. S. aureus ETs are serine proteases, which exhibit exquisite substrate specificity, and their mechanisms of action are extremely complex. To date, four different serotypes of ETs have been identified and three of them (ETA, ETB and ETD) are associated with toxin‐mediated staphylococcal syndromes related to human infections leading to diseases of medical and veterinary importance

Prime Focus Spectrograph - Subaru's future -

The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera. Fibers then carry light to a set of four identical fast-Schmidt spectrographs with three color arms each: the wavelength ranges from 0.38 {\mu}m to 1.3 {\mu}m will be simultaneously observed with an average resolving power of 3000. Before and during the era of extremely large telescopes, PFS will provide the unique capability of obtaining spectra of 2400 cosmological/astrophysical targets simultaneously with an 8-10 meter class telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil, Caltech/JPL, Princeton, & JHU in USA, LAM in France, ASIAA in Taiwan, and NAOJ/Subaru.Comment: 13 pages, 11 figures, submitted to "Ground-based and Airborne Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki Takami, Editors, Proc. SPIE 8446 (2012)

Morfologia dos órgãos genitais do macho do Lobo marinho (Arctocephalus australis) e implicações biológicas

Male capacity for spreading genes to a great number of descendents and to determine population dynamics depend directly on the genital organs. Morphological studies in pinnipeds are scarce and the functional meaning of some characteristics has never been discussed. We hypothesized that Arctocephalus australis (A. australis) shows morphophysiological adaptations in order to guarantee the perpetuation of the species in the unique annual mating season. Seven males, dead from natural causes, had their genital organs collected and fixed for morphological description. Some features differ from other described mammalian males and are closely related to the biology and reproductive cycle of this species, as the scrotal epidermis, absence of glandular portion in the ductus deferens and spermatogenic epithelium suggest a recrudescent testis period. The corona glandis exhibits a singular arrangement: its erectile border looks like a formation of petals and its association with the os penis gives a "lily-flower" form to this region. We propose the name margo petaliformis to this particular erectile border of the corona glandis because of its similarity to a flower corola. The male genital organs of A. australis show morphological features compatible with adaptation to environment requirements and reproductive efficiency

Beliefs and traditions related to a child´s first year of life : a study of the Northwest of Portugal

In this paper we propose an approach to investigate, in the North-west of Portugal, the parents’ behaviour at birth and during the first year of life of their children. We compare the heritage, specifically the beliefs and traditions, with the changes that resulted from the recent and deep cultural transformations that have taken place in Portugal in the last few decades. In parallel, we tried to determine if the parents’ behaviours, based on beliefs and traditions, can affect the children’s health. We based our investigation on standardized interviews with 76 mothers of one-year-old children (born between January and December 2001) who lived in two parishes of Vizela city. This is a territory where a more traditional way of life prevails than in other territories of the centre and south of the country, where there is a strong attachment for religious and social values and where the influence of the ancestral traditions is still alive. The paper concludes that cultural heritage can have important impact on individual health. Health professionals, who work in primary care and in hospitals, must be aware of the responsibility they have to change this scenario.(undefined

Exfoliative toxin E, a new Staphylococcus aureus virulence factor with host-specific activity

Exfoliative toxin E, a new [i]Staphylococcus aureus[/i] virulence factor with host-specific activity. Microbes, 15e Congrès National de la SF

DNA strand break repair and neurodegeneration.

A number of DNA repair disorders are known to cause neurological problems. These disorders can be broadly characterised into early developmental, mid-to-late developmental or progressive. The exact developmental processes that are affected can influence disease pathology, with symptoms ranging from early embryonic lethality to late-onset ataxia. The category these diseases belong to depends on the frequency of lesions arising in the brain, the role of the defective repair pathway, and the nature of the mutation within the patient. Using observations from patients and transgenic mice, we discuss the importance of double strand break repair during neuroprogenitor proliferation and brain development and the repair of single stranded lesions in neuronal function and maintenance