Colonization and demographic expansion of freshwater fauna across the Hawaiian archipelago.

It is widely accepted that insular terrestrial biodiversity progresses with island age because colonization and diversification proceed over time. Here, we assessed whether this principle extends to oceanic island streams. We examined rangewide mtDNA sequence variation in four stream-dwelling species across the Hawaiian archipelago to characterize the relationship between colonization and demographic expansion, and to determine whether either factor reflects island age. We found that colonization and demographic expansion are not related and that neither corresponds to island age. The snail Neritina granosa exhibited the oldest colonization time (~2.713 mya) and time since demographic expansion (~282 kya), likely reflecting a preference for lotic habitats most prevalent on young islands. Conversely, gobioid fishes (Awaous stamineus, Eleotris sandwicensis and Sicyopterus stimpsoni) colonized the archipelago only ~0.411-0.935 mya, suggesting ecological opportunities for colonization in this group were temporally constrained. These findings indicate that stream communities form across colonization windows, underscoring the importance of ecological opportunities in shaping island freshwater diversity.

Local adaptation despite high gene flow in the waterfall-climbing Hawaiian goby, Sicyopterus stimpsoni.

Environmental heterogeneity can promote the emergence of locally adapted phenotypes among subpopulations of a species, whereas gene flow can result in phenotypic and genotypic homogenization. For organisms like amphidromous fishes that change habitats during their life history, the balance between selection and migration can shift through ontogeny, making the likelihood of local adaptation difficult to predict. In Hawaiian waterfall-climbing gobies, it has been hypothesized that larval mixing during oceanic dispersal counters local adaptation to contrasting topographic features of streams, like slope gradient, that can select for predator avoidance or climbing ability in juvenile recruits. To test this hypothesis, we used morphological traits and neutral genetic markers to compare phenotypic and genotypic distributions in recruiting juveniles and adult subpopulations of the waterfall-climbing amphidromous goby, Sicyopterus stimpsoni, from the islands of Hawai'i and Kaua'i. We found that body shape is significantly different between adult subpopulations from streams with contrasting slopes and that trait divergence in recruiting juveniles tracked stream topography more so than morphological measures of adult subpopulation differentiation. Although no evidence of population genetic differentiation was observed among adult subpopulations, we observed low but significant levels of spatially and temporally variable genetic differentiation among juvenile cohorts, which correlated with morphological divergence. Such a pattern of genetic differentiation is consistent with chaotic genetic patchiness arising from variable sources of recruits to different streams. Thus, at least in S. stimpsoni, the combination of variation in settlement cohorts in space and time coupled with strong postsettlement selection on juveniles as they migrate upstream to adult habitats provides the opportunity for morphological adaptation to local stream environments despite high gene flow.

Are species differences in maternal effects arising from maternal care adaptive?

Parental care benefits offspring through maternal effects influencing their development, growth and survival. However, although parental care in general is likely the result of adaptive evolution, it does not follow that specific differences in the maternal effects that arise from care are also adaptive. Here, we used an interspecific cross-fostering design in the burying beetle species Nicrophorus orbicollis and N. vespilloides, both of which have elaborate parental care involving direct feeding of regurgitated food to offspring, to test whether maternal effects are optimized within a species and therefore adaptive. Using a full-factorial design, we first demonstrated that N. orbicollis care for offspring longer regardless of recipient species. We then examined offspring development and mass in offspring reared by hetero- or conspecific parents. As expected, there were species-specific direct effects independent of the maternal effects, as N. orbicollis larvae were larger and took longer to develop than N. vespilloides regardless of caregiver. We also found significant differences in maternal effects: N. vespilloides maternal care caused more rapid development of offspring of either species. Contrary to expectations if maternal effects were species-specific, there were no significant interactions between caretaker and recipient species for either development time or mass, suggesting that these maternal effects are general rather than optimized within species. We suggest that rather than coadaptation between parents and offspring performance, the species differences in maternal effects may be correlated with direct effects, and that their evolution is driven by selection on those direct effects.

HOXA3 accelerates wound healing in diabetic and aged non-diabetic mammals.

Chronic wounds are characterized by a persistent, hyper-inflammatory environment that prevents progression to regenerative wound closure. Such chronic wounds are especially common in diabetic patients, often requiring distal limb amputation, but occur in non-diabetic, elderly patients as well. Induced expression of HoxA3, a member of the Homeobox family of body patterning and master regulatory transcription factors, has been shown to accelerate wound closure in diabetic mice when applied topically as a plasmid encased in a hydrogel. We now provide independent replication of those foundational in vivo diabetic wound closure studies, observing 16% faster healing (3.3 mm wounds vs 3.9 mm wounds at Day 9 post original injury of 6 mm diameter) under treatment with observable microscopic benefits. We then expand upon these findings with minimal dose threshold estimation of 1 µg HoxA3 plasmid delivered topically at a weekly interval. Furthermore, we observed similarities in natural wound healing rates between aged non-diabetic mice and young diabetic mice, which provided motivation to test topical HoxA3 plasmid in aged non-diabetic mice. We observed that HoxA3 treatment achieved complete wound closure (0 mm diameter) at 2 weeks whereas untreated wounds were only 50% closed (3 mm wound diameter). We did not observe any gross adverse effects macroscopically or via histology in these short studies. Whether as a plasmid or future alternative modality, topical HoxA3 is an attractive translational candidate for chronic wounds.

Self-reported beta-lactam allergy in government and private hospitals in Cape Town, South Africa.

BACKGROUND: Up to a quarter of inpatients in high-income countries (HICs) self-report beta-lactam allergy (BLA), which if incorrect,increases the use of alternative antibiotics, worsening individual health outcomes and driving bacterial resistance. In HICs, up to 95% ofself-reported BLAs are incorrect. The epidemiology of BLA in low- and middle-income African countries is unknown. OBJECTIVES: To describe the epidemiology and de-labelling outcomes of self-reported BLA in hospitalised South African (SA) patients. METHODS: Point-prevalence surveys were conducted at seven hospitals (adult, paediatric, government and privately funded, district andtertiary level) in Cape Town, SA, between April 2019 and June 2021. Ward prescription records and in-person interviews were conductedto identify and risk-stratify BLA patients using the validated PEN-FAST tool. De-labelling was attempted at the tertiary allergy clinic atGroote Schuur Hospital. RESULTS: A total of 1 486 hospital inpatients were surveyed (1 166 adults and 320 children). Only 48 patients (3.2%) self-reported a BLA,with a higher rate in private than in government-funded hospitals (6.3% v. 2.8%; p=0.014). Using the PEN-FAST tool, only 10.4% (n=5/48)of self-reported BLA patients were classified as high risk for true penicillin hypersensitivity. Antibiotics were prescribed to 70.8% (n=34/48)of self-reported BLA patients, with 64.7% (n=22/34) receiving a beta-lactam. Despite three attempts to contact patients for de-labelling atthe allergy clinic, only 3/36 underwent in vivo testing, with no positive results, and 1 patient proceeded to a negative oral challenge. CONCLUSION: Unlike HICs, self-reported BLA is low among inpatients in SA. The majority of those who self-reported BLA were low risk fortype 1 hypersensitivity, but outpatient de-labelling efforts were largely unsuccessful.

New insights into the 243Am + 48Ca reaction products previously observed in the experiments on elements 113, 115, and 117.

Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction (243)Am+(48)Ca are presented. Twenty-one new decay chains originating from (288)115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus (291)115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E*=33 MeV, for the first time we registered the product of the 2n-evaporation channel, (289)115, which was also observed previously in the reaction (249)Bk+(48)Ca as the daughter nucleus of the decay of (293)117. The maximum cross section for the production of (288)115 is found to be 8.5 pb at E*≈36 MeV.

Production and decay of the heaviest nuclei (293,294)117 and (294)118.

Two years after the discovery of element 117, we undertook a second campaign using the (249)Bk+(48)Ca reaction for further investigations of the production and decay properties of the isotopes of element 117 on a larger number of events. The experiments were started in the end of April 2012 and are still under way. This Letter presents the results obtained in 1200 hours of an experimental run with the beam dose of (48)Ca of about 1.5×10(19) particles. The (249)Bk target was irradiated at two energies of (48)Ca that correspond to the maximum probability of the reaction channels with evaporation of three and four neutrons from the excited (297)117. In this experiment, two decay chains of (294)117 (3n) and five decay chains of (293)117 (4n) were detected. In the course of the long-term work, (249)Cf-the product of decay of (249)Bk (330 d)-is being accumulated in the target. Consequently, in the present experiment, we also detected a single decay of the known isotope (294)118 that was produced during 2002-2005 in the reaction (249)Cf((48)Ca,3n)(294)118. The obtained results are compared with the data from previous experiments. The experiments are carried out in the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, using the heavy-ion cyclotron U400.

Finding paradise: cues directing the migration of the waterfall climbing Hawaiian gobioid Sicyopterus stimpsoni.

A series of waterfall-climbing trials were conducted to identify cues that direct the climbing of juvenile Sicyopterus stimpsoni. In the first experiment, whether climbing juveniles preferentially ascend water sources with conspecifics or whether the presence of just stream water is sufficient to attract fish to ascend a climbing path were assessed. In the second experiment, whether climbing juveniles create a trail of mucus that facilitates the ability of conspecifics to follow their lead was determined. The results indicate that juvenile S. stimpsoni are less likely to climb in waters devoid of organic cues but are strongly attracted to stream water with or without the odour of conspecifics. Once climbing, performance did not differ for juveniles climbing in differing water choices, suggesting an all-or-nothing commitment once climbing commences. Climbing S. stimpsoni did produce a mucous trail while climbing that was associated with a mucous gland that dramatically increases in size just prior to juveniles gaining the ability to climb. The trail was not followed closely by subsequent juveniles traversing the same channel, however, suggesting only weak trail-following in waterfall climbing S. stimpsoni. Previous genetic studies suggest that juvenile S. stimpsoni do not home to natal streams in the face of strong near-shore oceanic currents. Instead, these fish appear primarily to rely on cues that suggest the presence of organic growth in streams, a factor that may indicate suitable habitat in an ever-changing stream environment but which may also be vulnerable to interference through human activity.

On the adsorption and reactivity of element 114, flerovium.

Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly volatile and the least reactive member of group 14. Our experimental observations suggest that Fl exhibits lower reactivity towards Au than the volatile metal Hg, but higher reactivity than the noble gas Rn.

Uranium integral fission product yields for a spectrally-shaped 14.1 MeV neutron source at the National Ignition Facility.

This paper describes the experimental results for an energy tuning assembly created to modify the National Ignition Facility deuterium-tritium fusion neutron source into a notional thermonuclear and prompt fission neutron spectrum, which has applications in integral measurements, nuclear data benchmarks, and radiation effects on microelectronics. The Monte Carlo neutron transport utilized MCNP5 to estimate the ETA-modified fluence using the ENDF-B/VIII.0 and IRDFF-II continuous energy nuclear data libraries, and SCALE Sampler was used to estimate the systematic nuclear data covariance using ENDF-B/VII.1 and IRDFF-II in a 252-group structure. The experiment fielded eight activation foils and a highly enriched uranium sample. This provided fifteen reaction channels that were used in a forward-fit comparison to the modeled results and to unfold the neutron spectrum using STAYSL. Gamma-ray spectrometry was performed on the activation and highly enriched uranium foils, and the reduced χ2 between the modeled and experimental values was 1.21. The results from the STAYSL unfold, reduced χ2=1.62, indicated that the modeled neutron spectrum was achieved and the systematic nuclear data uncertainty associated with the neutron transport and activation product cross sections was representative of the experiment. Integral cumulative fission product yield data were collected for 37 mass chains with a combination of gamma-ray spectrometry and radiochemical analysis. Fission product analysis was generally in agreement with two models using a semi-empirical fit and the General Observables of Fission code, with the exception of mass chains 88, 109, 111, 112, 113, 129, 139, 142, 144, 151, and 156.

Processing, assembly and localization of a Bacillus anthracis spore protein.

All Bacillus spores are encased in macromolecular shells. One of these is a proteinacious shell called the coat that, in Bacillus subtilis, provides critical protective functions. The Bacillus anthracis spore is the infectious particle for the disease anthrax. Therefore, the coat is of particular interest because it may provide essential protective functions required for the appearance of anthrax. Here, we analyse a protein component of the spore outer layers that was previously designated BxpA. Our data indicate that a significant amount of BxpA is located below the spore coat and associated with the cortex. By SDS-PAGE, BxpA migrates as a 9 kDa species when extracted from Sterne strain spores, and as 11 and 14 kDa species from Ames strain spores, even though it has predicted masses of 27 and 29 kDa, respectively, in these two strains. We investigated the possibility that BxpA is subject to post-translational processing as previously suggested. In B. subtilis, a subset of coat proteins is proteolysed or cross-linked by the spore proteins YabG or Tgl, respectively. To investigate the possibility that similar processing occurs in B. anthracis, we generated mutations in the yabG or tgl genes in the Sterne and Ames strains and analysed the consequences for BxpA assembly by SDS-PAGE. We found that in a tgl mutant of B. anthracis, the apparent mass of BxpA increased. This is consistent with the possibility that Tgl directs the cross-linking of BxpA into a form that normally does not enter the gel. Unexpectedly, the apparent mass of BxpA also increased in a yabG mutant, suggesting a relatively complex role for proteolysis in spore protein maturation in B. anthracis. These data reveal a previously unobserved event in spore protein maturation in B. anthracis. We speculate that proteolysis and cross-linking are ubiquitous spore assembly mechanisms throughout the genus Bacillus.

Synthesis of a new element with atomic number Z = 117.

The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes (293)117 and (294)117 were produced in fusion reactions between (48)Ca and (249)Bk. Decay chains involving 11 new nuclei were identified by means of the Dubna gas-filled recoil separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z > or = 111, validating the concept of the long sought island of enhanced stability for superheavy nuclei.

Fractionation of copper activation products in debris samples from the National Ignition Facility.

Nuclear fusion experiments performed at the National Ignition Facility produce radioactive debris, arising in reactions of fast neutrons with the target assembly. We have found that postshot debris collections are fractionated, such that isotope ratios in an individual debris sample may not be representative of the radionuclide inventory produced by the experiment. We discuss the potential sources of this fractionation and apply isotope-correlation techniques to calculate unfractionated isotope ratios that are used in measurements of nuclear reaction cross sections.

Gamma spectrometry in the ITWG CMX-4 exercise.

Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.

Distribution of collected target debris using the large area solid debris radiochemistry collector.

A large area solid radiochemistry collector was deployed at the National Ignition Facility (NIF) with a collection efficiency for post-shot, solid target debris of approximately 1% of the total 4π solid angle. The collector consisted of a 20-cm diameter vanadium foil surrounded by an aluminum side-enclosure and was fielded 50 cm from the NIF target. The collector was used on two NIF neutron yield shots, both of which had a monolayer of 238U embedded in the capsule ablator 10 µm from the inner surface. Fission and activation products produced in the 238U were collected, and subsequent analyses via gamma spectroscopy indicated that the distribution of fission products was not uniform, with peak and valley fission products preferentially collected on the vanadium and low- and high-mass fission products primarily located on the aluminum side-enclosure. The results from these shots will be used to design future nuclear data experiments at NIF.

Production and separation of carrier-free 7Be.

A high-purity carrier-free (7)Be was efficiently isolated following proton bombardment of a lithium hydroxide-aluminum target. The separation of beryllium from lithium and aluminum was achieved through a hydrochloric acid elution system utilizing cation exchange chromatography. The beryllium recovery, +99%, was assessed through gamma spectroscopy while the chemical purity was established by mass spectrometry. The decontamination factors of beryllium from lithium and aluminum were determined to be 6900 and 300, respectively.

Recent advances and results from the solid radiochemistry nuclear diagnostic at the National Ignition Facility.

The solid debris collection capability at the National Ignition Facility has been expanded to include a third line-of-sight assembly. The solid radiochemistry nuclear diagnostic measurement of the ratio of gold isotopes is dependent on the efficient collection of neutron-activated hohlraum debris by passive metal disks. The collection of target debris at this new location is more reliable in comparison to the historic locations, and it appears to be independent of collector surface ablation.

Note: Radiochemical measurement of fuel and ablator areal densities in cryogenic implosions at the National Ignition Facility.

A new radiochemical method for determining deuterium-tritium (DT) fuel and plastic ablator (CH) areal densities (ρR) in high-convergence, cryogenic inertial confinement fusion implosions at the National Ignition Facility is described. It is based on measuring the (198)Au/(196)Au activation ratio using the collected post-shot debris of the Au hohlraum. The Au ratio combined with the independently measured neutron down scatter ratio uniquely determines the areal densities ρR(DT) and ρR(CH) during burn in the context of a simple 1-dimensional capsule model. The results show larger than expected ρR(CH) values, hinting at the presence of cold fuel-ablator mix.

An animal model for Lyme arthritis.

A model of Lyme arthritis has been developed in laboratory rats. Intraperitoneal inoculation of a low-passage tick isolate of B. burgdorferi into neonatal and weanling LEW/N rats resulted in multisystemic infection and arthritis. Spirochetes were isolated from blood, liver, kidney, spleen, brain, and joints of inoculated rats. Arthritis, associated with the presence of spirochetes, developed in multiple joints by day 14 and persisted through day 90 after inoculation. Arthritic lesions resembled those found in human Lyme disease lesions. Lesions were not found in other organs, although spirochetes were present. Neonatal F344 and SD rats were also susceptible to infection and induction of arthritis. Three different isolates of B. burgdorferi were shown to be pathogenic. Pathogenicity of one isolate was retained after at least 11 in vitro passages. Formalin-killed spirochetes were not pathogenic. Other features of the Lyme disease complex have yet to be seen in the rat, but long-term studies are required to completely define the rat model. This highly reproducible model should allow in-depth studies on the pathogenetic mechanisms of this important human disease.

Relative infectivity of Borrelia burgdorferi in Lewis rats by various routes of inoculation.

Various routes of Borrelia burgdorferi infection were studied in laboratory rats. Three-week-old Lewis rats were inoculated either intradermally (i.d.), intraperitoneally (i.p.), or oronasally (o.n.) with serial 10-fold dilutions of B. burgdorferi. Thirty days later, groups of rats were killed and serology, splenic culture, and histology were used to evaluate infection. Rats were successfully infected i.d. with 10(2-4) organisms or i.p. with 10(4-5) organisms. Neither three-day-old nor three-week-old rats were successfully infected o.n. with up to 10(6) organisms. For contact transmission, three-day-old or three-week-old inoculated rats were housed with unexposed littermates for 30 days. Inoculated rats became infected but contact rats remained free of infection. To study in utero transmission, five pregnant female Lewis rats were inoculated i.p. with 10(6) spirochetes at four days gestation. Although adult females seroconverted or had positive splenic cultures at 20 days gestation, the placentas and fetuses were uniformly culture-negative. Venereal transmission from seven infected females or six infected males to uninfected rats of the opposite sex was not demonstrated.