Continuity of phonon dispersion curves in layered ionic materials.

The coupling of lattice vibrations with macroscopic electric fields in ionic crystals is examined from first principles based on density functional theory and density functional perturbation theory. Our analyses show that the coupled optical phonon-photon modes are well represented by using the pure phonon modes evaluated at [Formula: see text] as a basis. In addition, we find that apparent 'discontinuities' and mode 'disappearances' in the phonon dispersion curves of ionic materials for [Formula: see text] in hexagonal and other anisotropic materials are caused by the directional dependence of the Born effective charge tensor which is responsible for this coupling. The full dispersion curves, including the phonon-photon transverse modes are shown to be continuous functions of wavevector. Our work in this report provides a promising tool for first principles evaluation of phonon polaritons that may be accessible to experiment. Explicit examples are explored for cubic and hexagonal BN; the calculated results are in good agreement with previous computational values and available experimental measurements.

Life Goals Over Time Among Homeless Adults in Permanent Supportive Housing.

Permanent supportive housing (PSH) is a widely-accepted solution to the challenge of chronic homelessness. While housing support and retention, physical health, and healthcare continue to be important for formerly homeless persons in PSH, "higher-order" and humanistic needs such as thriving have received less attention and as a result are less well understood in this population. One important indicator of thriving is the ability to establish and articulate life goals. This study utilizes longitudinal data from 421 formerly homeless adults prior to their move into PSH, and at 3-, 6- and 12-months after move-in (369 respondents completed all four interviews), to examine what life goals are articulated by this population and how those goals change over time. Prior to housing, most respondents articulated housing attainment as their primary life goal, whereas at follow-up interviews health goals, housing relocation, and financial goals became more prevalent. Aspirational goals (e.g., independence, self-improvement, artistic pursuits) were also common, but demonstrated a decrease over time in housing. Relationship goals remained common and consistent over time. Findings indicate that housing is a necessary, but perhaps not sufficient, step for improving thriving among formerly homeless adults. Implications for practice and future research are discussed.

Investigation of synthetic aperture methods in ultrasound surface imaging using elementary surface types.

Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3mm, 2.9mm and 2.0mm respectively, while those for TFM imaging were 3.7mm, 3.0mm and 3.1mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was established that the reduced error associated with the SAFT technique was associated with significant reductions in side lobe levels of approximately 24dB in comparison to TFM imaging, although this came at the expense of reduced resolution and coverage.

Abstracts of the 24th international isotope society (UK group) symposium: synthesis and applications of labelled compounds 2015.

The 24th annual symposium of the International Isotope Society's United Kingdom Group took place at the Møller Centre, Churchill College, Cambridge, UK on Friday 6th November 2015. The meeting was attended by 77 delegates from academia and industry, the life sciences, chemical, radiochemical and scientific instrument suppliers. Delegates were welcomed by Dr Ken Lawrie (GlaxoSmithKline, UK, chair of the IIS UK group). The subsequent scientific programme consisted of oral presentations, short 'flash' presentations in association with particular posters and poster presentations. The scientific areas covered included isotopic synthesis, regulatory issues, applications of labelled compounds in imaging, isotopic separation and novel chemistry with potential implications for isotopic synthesis. Both short-lived and long-lived isotopes were represented, as were stable isotopes. The symposium was divided into a morning session chaired by Dr Rebekka Hueting (University of Oxford, UK) and afternoon sessions chaired by Dr Sofia Pascu (University of Bath, UK) and by Dr Alan Dowling (Syngenta, UK). The UK meeting concluded with remarks from Dr Ken Lawrie (GlaxoSmithKline, UK).

Coordinate expansion of murine hematopoietic and mesenchymal stem cell compartments by SHIPi.

Promoting the expansion of adult stem cell populations offers the potential to ameliorate radiation or chemotherapy-induced bone marrow failure and allows for expedited recovery for patients undergoing these therapies. Previous genetic studies suggested a pivotal role for SH2 domain-containing inositol-5-phosphatase 1 (SHIP1) in limiting the size of the hematopoietic stem cell (HSC) compartment. The aim of this study was to determine whether our recent development of small molecule SHIP1 inhibitors offers the potential for pharmacological expansion of the HSC compartment in vivo. We show here that treatment of mice with aminosteroid inhibitors of SHIP1 (SHIPi) more than doubles the size of the adult mesenchymal stem cell (MSC) compartment while simultaneously expanding the HSC pool sixfold. Consistent with its ability to target SHIP1 function in vivo, SHIPi also significantly increases plasma granulocyte colony-stimulating factor (G-CSF) levels, a growth factor that supports proliferation of HSC. Here, we show that SHIPi-induced G-CSF production mediates HSC and MSC expansion, as in vivo neutralization of G-CSF abrogates the SHIPi-induced expansion of both the HSC and MSC compartments. Due to its expansionary effect on adult stem cell compartments, SHIPi represents a potential novel strategy to improve declining stem cell function in both therapy induced and genetically derived bone marrow failure syndromes.

Economic contraction, alcohol intoxication and suicide: analysis of the National Violent Death Reporting System.

OBJECTIVES: Although there is a large and growing body of evidence concerning the impact of contracting economies on suicide mortality risk, far less is known about the role alcohol consumption plays in the complex relationship between economic conditions and suicide. The aims were to compare the postmortem alcohol intoxication rates among male and female suicide decedents before (2005-2007), during (2008-2009) and after (2010-2011) the economic contraction in the USA. METHODS: Data from the restricted National Violent Death Reporting System (2005-2011) for male and female suicide decedents aged 20 years and older were analysed by Poisson regression analysis to test whether there was significant change in the fractions of suicide decedents who were acutely intoxicated at the time of death (defined as blood alcohol content ≥0.08 g/dL) prior, during and after the downturn. RESULTS: The fraction of all suicide decedents with alcohol intoxication increased by 7% after the onset of the recession from 22.2% in 2005-2007 to 23.9% in 2008-2011. Compared with the years prior to the recession, male suicide decedents showed a 1.09-fold increased risk of alcohol intoxication within the first 2 years of the recession. Surprisingly, there was evidence of a lag effect among female suicide decedents, who had a 1.14-fold (95% CI 1.02 to 1.27) increased risk of intoxication in 2010-2011 compared with 2005-2007. CONCLUSIONS: These findings suggest that acute alcohol intoxication in suicide interacts with economic conditions, becoming more prevalent during contractions.

Impaired T-cell survival promotes mucosal inflammatory disease in SHIP1-deficient mice.

T cells have a critical role in immune surveillance at mucosal surfaces. SHIP1(-/-) mice succumb to mucosal inflammatory disease that afflicts the lung and small intestine (SI). The basis of this condition has not been defined. Here we show that SHIP1 is required for the normal persistence and survival of T cells in mucosal tissues. We find that CD4 and CD8 effector T cells are reduced; however, Treg cells are increased in the SI and lungs of SHIP1(-/-) and CD4CreSHIP(flox/flox) mice. Furthermore, a subset of T cells in the SI of SHIP1(-/-) mice are FasL(+) and are more susceptible to extrinsic cell death. Mechanistic analyses showed that SHIP1 associates with the death receptor CD95/Fas and treatment with a Caspase 8 inhibitor prevents SHIP1 inhibitor-mediated T-cell death. Notably, mucosal inflammation in SHIP1(-/-) mice is reduced by treatment with a Caspase 8 inhibitor. We also find that the incidence of Crohn's disease (CD) and pneumonia is significantly increased in mice with dual T and myeloid lineage SHIP1 deletion but not in single lineage-deleted mice. Thus, by promoting survival of protective T cells, thereby preventing an inflammatory myeloid response, SHIP1 maintains an appropriate balance of innate immune function at mucosal surfaces necessary for immune homeostasis.

Practically convenient and industrially-aligned methods for iridium-catalysed hydrogen isotope exchange processes.

The use of alternative solvents in the iridium-catalysed hydrogen isotope exchange reaction with developing phosphine/NHC Ir(I) complexes has identified reaction media which are more widely applicable and industrially acceptable than the commonly employed chlorinated solvent, dichloromethane. Deuterium incorporation into a variety of substrates has proceeded to deliver high levels of labelling (and regioselectivity) in the presence of low catalyst loadings and over short reaction times. The preparative outputs have been complemented by DFT studies to explore ligand orientation, as well as solvent and substrate binding energies within the catalyst system.

SHIP-1 deficiency in the myeloid compartment is insufficient to induce myeloid expansion or chronic inflammation.

SHIP-1 has an important role in controlling immune cell function through its ability to downmodulate PI3K signaling pathways that regulate cell survival and responses to stimulation. Mice deficient in SHIP-1 display several chronic inflammatory phenotypes including antibody-mediated autoimmune disease, Crohn's disease-like ileitis and a lung disease reminiscent of chronic obstructive pulmonary disease. The ileum and lungs of SHIP-1-deficient mice are infiltrated at an early age with abundant myeloid cells and the mice have a limited lifespan primarily thought to be due to the consolidation of lungs with spontaneously activated macrophages. To determine whether the myeloid compartment is the key initiator of inflammatory disease in SHIP-1-deficient mice, we examined two independent strains of mice harboring myeloid-restricted deletion of SHIP-1. Contrary to expectations, conditional deletion of SHIP-1 in myeloid cells did not result in consolidating pneumonia or segmental ileitis typical of germline SHIP-1 deficiency. In addition, other myeloid cell abnormalities characteristic of germline loss of SHIP-1, including flagrant splenomegaly and enhanced myelopoiesis, were absent in mice lacking SHIP-1 in myeloid cells. This study indicates that the spontaneous inflammatory disease characteristic of germline SHIP-1 deficiency is not initiated solely by LysM-positive myeloid cells but requires the simultaneous loss of SHIP-1 in other hematolymphoid lineages.

Cobalt chloride induces metaphase when topically applied to larvae and pupae of the stingless bee Melipona scutellaris (Hymenoptera, Apidae, Meliponini).

In order to optimize preparations of bee metaphases, we tested cobalt chloride, which has been used as a metaphase inducer in other organisms, such as hamsters and fish. Four microliters of 65 mM cobalt chloride aqueous solution was topically applied to larval and pupal stages of the stingless bee Melipona scutellaris. The cerebral ganglion was removed after treatment and prepared for cytogenetic analysis. Identically manipulated untreated individuals were used as controls. The number of metaphases was increased 3-fold in treated individuals compared to controls. The micronucleus test showed no mutagenic effects of cobalt chloride on M. scutellaris cells. We concluded that cobalt chloride is a metaphase-inducing agent in M. scutellaris, thus being useful for cytogenetic analyses.

Myeloid cell-specific expression of Ship1 regulates IL-12 production and immunity to helminth infection.

Helminth infection leads to the local proliferation and accumulation of macrophages in tissues. However, the function of macrophages during helminth infection remains unclear. SH2-containing inositol 5'-phosphatase 1 (Ship1, Inpp5d) is a lipid phosphatase that has been shown to play a critical role in macrophage function. Here, we identify a critical role for Ship1 in the negative regulation of interleukin (IL)-12/23p40 production by macrophages during infection with the intestinal helminth parasite Trichuris muris. Mice with myeloid cell-specific deletion of Ship1 (Ship1(ΔLysM) mice) develop a non-protective T-helper type 1 cell response and fail to expel parasites. Ship1-deficient macrophages produce heightened levels of IL-12/23p40 in vitro and in vivo and antibody blockade of IL-12/23p40 renders Ship1(ΔLysM) mice resistant to Trichuris infection. Our results identify a critical role for the negative regulation of IL-12/23p40 production by macrophages in the development of a protective T(H)2 cell response.

Number of malpighian tubules in larvae and adults of stingless bees (Hymenoptera: Apidae) from Amazonia.

The number of Malpighian tubules in larvae and adults of bees is variable. Larvae of Apis mellifera L. have four Malpighian tubules, while adults have 100 tubules. In stingless bees, this number varies from four to eight. The objectives of this study were to provide characteristics of the Malpighian tubules as well as to quantify their number in larvae and adults of six species of Meliponinae, Melipona seminigra merrillae Cockerell, Melipona compressipes manaosensis Schwarz, Melipona rufiventris Lepeletier, Scaptotrigona Moure, Frieseomelitta Ihering, and Trigona williana Friese. Malpighian tubules were dissected from larvae and adults, measured, quantified, and maintained in microtubes with Dietrich's solution. The numbers of Malpighian tubules were constant only for larvae of M. rufiventris (four and eight) and Scaptotrigona sp. (four). The most frequent number of tubules in the Melipona group was seven and eight in larvae, and 70 and 90 in adults. In the Trigona group were four and 20 to 40, for larvae and adults, respectively. The results showed differences in the number of Malpighian tubules among the species analyzed and also between the larvae and adults of the same species. Despite the variation observed, species of the group Melipona always have a larger number and longer Malpighian tubules in both larvae and adults as compared to the Trigona group, which may indicate an evolutionary trend of differentiation between these groups.

Gastric histology in children treated with proton pump inhibitors long term, with emphasis on enterochromaffin cell-like hyperplasia.

BACKGROUND: There are longstanding concerns that carcinoid tumours or atrophic gastritis might develop in children receiving proton pump inhibitors (PPIs) long term. In children, this has not been studied using stains sensitive and specific for enterochromaffin-like (ECL) cells. AIM: To evaluate gastric biopsies for ECL hyperplasia or gastric atrophy, in children treated long-term with PPIs. METHODS: Synaptophysin and chromogranin immunostaining, biopsies read anonymised, blinded. Endocrine cell numbers graded according to Rindi and Solcia. RESULTS: Of 130 children with gastro-oesophageal reflux disease (GERD), 65 had sequential gastric biopsies, starting at median 8.2 years (<1 to 17). Of the 65, 83% had GERD-predisposing conditions, mostly neurological impairment or repaired oesophageal atresia. Four hundred and fifty-eight tissue blocks (208 antrum, 250 body) were available from a mean of 5.8 endoscopies (2-14). Of 82 gastric body biopsies in 40 patients with ECL hyperplasia, 67 had grade 1 hyperplasia, 15 grade 2. Of the 40, nine had ECL hyperplasia before PPI use; all nine had received H2-receptor antagonists. Median duration of PPI use was 3.17 years in patients with ECL hyperplasia, 2.20 years in those without (P=0.16). Helicobacter pylori was present in four patients; two had ECL hyperplasia. PPI duration was >3 years in 24 patients. In nine patients who received H2-receptor antagonists, changes were present before PPI use. No patient had atrophic gastritis. CONCLUSIONS: A high percentage of children (61%) receiving long-term PPI continuously for up to 10.8 years (median 2.84 years) develop minor degrees of ECL hyperplasia. This has no known clinical significance. Children on PPIs for this duration do not appear to develop atrophic gastritis or carcinoid tumours.

Does beekeeping reduce genetic variability in Melipona scutellaris (Apidae, Meliponini)?

Many factors have contributed to reductions in wild populations of stingless bees, such as: deforestation, displacement and destruction of nests by honey gatherers, as well as use of insecticides and other agrochemicals. All of these can potentially affect the populational structure of native species. We analyzed genetic variability and populational structure of Melipona scutellaris, based on five microsatellite loci, using heterologous primers of M. bicolor. Samples were taken from 43 meliponaries distributed among 30 sites of four northeastern states of Brazil (Pernambuco, Alagoas, Sergipe, and Bahia). Thirty-one alleles were found to be well distributed among the populations, with sizes ranging from 85 to 146 bp. In general, there was a variable distribution and frequency of alleles among populations, with either exclusive and/or fixed alleles at some sites. The population of Pernambuco was the most polymorphic, followed by Bahia, Alagoas and Sergipe. The heterozygosity was Ho = 0.36 on average, much lower than what has been reported for M. bicolor (Ho = 0.65). Most populations were not under Hardy-Weinberg equilibrium. We found a higher variation within rather than among populations, indicating no genetic structuring in those bees maintained in meliponaries. This apparent homogenization may be due to intense beekeeping activity, including exchange of genetic material among beekeepers. Based on our findings, we recommend more studies of meliponaries and of wild populations in order to help orient management and conservation of these native pollinators.

A mixed colony of Scaptotrigona depilis and Nannotrigona testaceicornis (Hymenoptera, Apidae, Meliponina).

We describe a case of a spontaneously established mixed colony of two species of stingless bees. The host colony of Scaptotrigona depilis, an aggressive bee that forms large colonies, was invaded by workers of Nannotrigona testaceicornis, a smaller bee that forms small colonies. The host colony and the invading species colony were maintained in next boxes about 1.5 m apart. The N. testaceicornis colony had been recently divided. Observations were made daily for 10 min, and every two weeks the colony was opened for observations within the nest. Initially the host colony bees repulsed the invading species, but as their numbers built up, they were no longer able to defend the entrance. An estimated 60-90 N. testaceicornis workers lived integrated into the colony of S. depilis for 58 days. During this period, they reconstructed and maintained the entrance tube, changing it to an entrance typical of N. testaceicornis. They also collected food and building material for the host colony. Nannotrigona testaceicornis tolerated transit of S. depilis through the entrance, but did not allow the host species to remain within the tube, though the attacks never resulted in bee mortality. Aggression was limited to biting the wings; when the bees fell to the ground they immediately separated and flew back. There have been very few reports of spontaneously occurring mixed stingless bee colonies. It is difficult to determine what caused the association that we found; probably workers of N. testaceicornis got lost when we split their colony, and then they invaded the colony of S. depilis.

Infestation by Pyemotes tritici (Acari, Pyemotidae) causes death of stingless bee colonies (Hymenoptera: Meliponina).

We report the infestation of stingless bee nests by the mite Pyemotes tritici, which killed four colonies of Tetragonisca angustula and one colony of Frieseomelitta varia in Brazil. The first infected colony, a colony of T. angustula, came from an area between Uberlândia and Araguari, Minas Gerais. The transfer of the mites to the other colonies occurred through the transfer of infected combs and subsequent manipulations. Other colonies in the same meliponary, which had not been manipulated, were not infected. The infestation was terminated by isolating the dead colonies from the meliponary.

Climatic and anthropic influence on size and fluctuating asymmetry of Euglossine bees (Hymenoptera, Apidae) in a semideciduous seasonal forest reserve.

We examined the influence of climate and man on size and fluctuating asymmetry in two species of Euglossine bees collected from a semideciduous forest reserve. Sixty males of each species were collected; four measurements were made of their wings to obtain a multivariable size index and a fluctuating asymmetry index. No significant differences in the size of Eulaema nigrita Lepeletier were found between the areas and seasons. Larger males of Euglossa pleosticta Dressler were collected during the hot and wet season; however, male size did not vary with location. Higher rainfall and a consequent increase in food availability could have influenced the increase in size of E. pleosticta. Bees collected during the hot and wet season at the forest border were more asymmetric than bees collected during the cold and dry season; the latter were found inside the forest. This indicates that climate and anthropic interferences influence the stability of development of E. pleosticta. Consequently, this species could be used as a bioindicator of stress. Apparently, E. nigrita is more resistant to environmental interference.

Are lifetime abstainers the best control group in alcohol epidemiology? On the stability and validity of reported lifetime abstention.

Lifetime abstainers have often been recommended as the comparison group in alcohol epidemiology. The objective of this study was to provide insight into the validity and stability of lifetime abstention by using data derived from the National Alcohol Survey, a national probability survey of US households conducted in 1984, and its 2 follow-up surveys conducted in 1990 and 1992. Results indicated that more than half (52.9%; all proportions were weighted to represent the US population) of those who reported never having a drink of any alcoholic beverage in the 1992 survey reported drinking in previous surveys. Depending on assumptions, this difference may result in an underestimation of alcohol-attributable mortality of 2%-15% in men and 2%-22% in women. Sociodemographic factors differentiated those who consistently reported lifetime abstention across surveys from the rest of the study population. Results suggest that using reported lifetime abstainers as a sole comparison group is problematic, especially if reporting is based on 1 measurement only. Establishing multiple measurement points and including irregular lifetime light drinkers with lifetime abstainers as the comparison group are recommended for future epidemiologic studies.