Aluminyl derived ethene functionalization with heteroallenes, leading to an intramolecular ligand rearrangement.

The aluminacyclopropane K[Al(NON)(η-C2H4)] ([NON]2- = [O(SiMe2NDipp)2]2-, Dipp = 2,6-iPr2C6H3) reacts with CO2 and iPrNCNiPr to afford ring-expanded products of C-C bond formation. The latter system undergoes a 1,3-silyl retro-Brook rearrangement of the NON-group, to afford the [NNO]2- ligand ([NNO]2- = [N(Dipp)SiMe2N(Dipp)SiMe2O]2-). The mechanism of transformation was examined by density functional theory (DFT).

Pinacol Cross-Coupling Promoted by an Aluminyl Anion.

A simple sequential addition protocol for the reductive coupling of ketones and aldehydes by a potassium aluminyl grants access to unsymmetrical pinacolate derivatives. Isolation of an aluminium ketyl complex presents evidence for the accessibility of radical species. Product release from the aluminium centre was achieved using an iodosilane, forming the disilylated 1,2-diol and a neutral aluminium iodide, thereby demonstrating the steps required to generate a closed synthetic cycle for pinacol (cross) coupling at an aluminyl anion.

Three Oxidative Addition Routes of Alkali Metal Aluminyls to Dihydridoaluminates and Reactivity with CO2.

Three distinct routes are reported to the soluble, dihydridoaluminate compounds, AM[Al(NONDipp )(H)2 ] (AM=Li, Na, K, Rb, Cs; [NONDipp ]2- =[O(SiMe2 NDipp)2 ]2- ; Dipp=2,6-iPr2 C6 H3 ) starting from the alkali metal aluminyls, AM[Al(NONDipp )]. Direct H2 hydrogenation of the heavier analogues (AM=Rb, Cs) produced the first examples of structurally characterized rubidium and caesium dihydridoaluminates, although harsh conditions were required for complete conversion. Using 1,4-cyclohexadiene (1,4-CHD) as an alternative hydrogen source in transfer hydrogenation reactions provided a lower energy pathway to the full series of products for AM=Li-Cs. A further moderation in conditions was noted for the thermal decomposition of the (silyl)(hydrido)aluminates, AM[Al(NONDipp )(H)(SiH2 Ph)]. Probing the reaction of Cs[Al(NONDipp )] with 1,4-CHD provided access to a novel inverse sandwich complex, [{Cs(Et2 O)}2 {Al(NONDipp )(H)}2 (C6 H6 )], containing the 1,4-dialuminated [C6 H6 ]2- dianion and representing the first time that an intermediate in the commonly utilized oxidation process of 1,4-CHD to benzene has been trapped. The synthetic utility of the newly installed Al-H bonds has been demonstrated by their ability to reduce CO2 under mild conditions to form the bis-formate AM[Al(NONDipp )(O2 CH)2 ] compounds, which exhibit a diverse series of eyecatching bimetallacyclic structures.

Temporal expression of avian ß defensin 10 and cathelicidins in the yolk sac tissue of broiler and layer embryos.

The yolk sac is a multifunctional organ, which not only participates in nutrient absorption, but also plays an important role in immune function. The objective of this study was to compare the mRNA abundance of avian ß-defensin 10 (AvBD10) and 3 cathelicidins (CATH1, CATH2, and CATH3) in the yolk sac tissue (YST) of commercial broilers and white egg and brown egg commercial layers. AvBD10 and CATH mRNA abundance was analyzed using two-way ANOVA and Tukey's test, with P < 0.05 being considered significant. AvBD10 and CATH mRNA showed similar temporal expression patterns in the YST of both broiler and layers, with an increase from embryonic day (E) 7 to E9 through E13 followed by a decrease to day of hatch. AvBD10 mRNA showed a breed × age interaction with greater expression in the YST of both layers compared to broilers at E9 and E11. CATH1 mRNA was greater in the YST of brown egg layers than broilers. CATH2 mRNA showed a breed × age interaction, with greater expression in the YST of brown egg layers than broilers at E11. CATH3 mRNA showed no difference in the YST between layers and broilers. Because broilers and brown egg layers are genetically related, these results show that selection for production parameters (broiler vs. layer) and not genetic relatedness (white egg layer vs. brown egg layer and broilers) is the basis for the differences in AvBD10, CATH1, and CATH2 mRNA in the YST of broilers and layers. The yolk-free body weights of broiler embryos were greater than that of both brown and white egg layers from E9 to 17. One possible explanation is that the reduced expression of AvBD10, CATH1 and CATH2 mRNA in the YST of broilers compared to layers at E9 and 11 may be due to faster embryonic growth at the expense of host defense peptide expression in broilers compared to layers.

Synthesis, Characterization, and Structural Analysis of AM[Al(NONDipp)(H)(SiH2Ph)] (AM = Li, Na, K, Rb, Cs) Compounds, Made Via Oxidative Addition of Phenylsilane to Alkali Metal Aluminyls.

We report the oxidative addition of phenylsilane to the complete series of alkali metal (AM) aluminyls [AM{Al(NONDipp)}]2 (AM = Li, Na, K, Rb, and Cs). Crystalline products (1-AM) have been isolated as ether or THF adducts, [AM(L)n][Al(NONDipp)(H)(SiH2Ph)] (AM = Li, Na, K, Rb, L = Et2O, n = 1; AM = Cs, L = THF, n = 2). Further to this series, the novel rubidium rubidiate, [{Rb(THF)4}2(Rb{Al(NONDipp)(H)(SiH2Ph)}2)]+ [Rb{Al(NONDipp)(H)(SiH2Ph)}2]-, was isolated during an attempted recrystallization of Rb[Al(NONDipp)(H)(SiH2Ph)] from a hexane/THF mixture. Structural and spectroscopic characterizations of the series 1-AM confirm the presence of µ-hydrides that bridge the aluminum and alkali metals (AM), with multiple stabilizing AM···π(arene) interactions to either the Dipp- or Ph-substituents. These products form a complete series of soluble, alkali metal (hydrido) aluminates that present a platform for further reactivity studies.

Isolating elusive 'Al(µ-O)M' intermediates in CO2 reduction by bimetallic Al-M complexes (M = Zn, Mg).

The reaction of compounds containing Al-Mg and Al-Zn bonds with N2O enabled isolation of the corresponding Al(µ-O)M complexes. Electronic structure analysis identified largely ionic Al-O and O-M bonds, featuring an anionic µ-oxo centre. Reaction with CO2 confirmed that these species correspond to the proposed intermediates in the formation of µ-carbonate compounds.

Comparison of major histocompatibility complex-B variability in Sri Lankan indigenous chickens with five global chicken populations using MHC-B SNP panel.

In the present study, we investigated the major histocompatibility complex (MHC)-B haplotypes diversity of Sri Lankan indigenous chickens from three different geographical sites consisting of highly mixed populations using 90 SNPs in the MHC-B region. A total of 48 haplotypes were identified. Those included 37 novel haplotypes and 11 previously identified 'standard' haplotypes. The MHC-linked marker, LEI0258, had 23 alleles showing less diversity than defined by MHC-B SNP haplotypes. Among those identified haplotypes, five standard haplotypes-BSNP-O02, BSNP-M01, BSNP-A04, BSNP-K03, BSNP-T04-were most commonly observed, suggesting past introgression of imported breeds. Comparison of the MHC-B haplotypes of Sri Lankan and four other global populations with previously defined haplotypes indicated the sharing of 23 standard haplotypes with common origins. Novel haplotypes are population-specific and not shared among the geographical boundaries. Backyard indigenous chickens are unselected, highly crossbred, and generally thrive under dynamic environmental conditions. Hence free-range production systems may be responsible for maintaining high diversity in the MHC-B region with novel haplotypes.

Synthesis and Reactivity of Acyclic Germanimines: Silyl Rearrangement and Cycloadditions.

We report the synthesis of aromatic germanimines [(HMDS)2Ge═NAr] (Ar = Ph, Mes, Dipp; Mes = 2,4,6-Me3C6H2, Dipp = 2,6-iPr2C6H3) and an investigation into their associated reactivity. [(HMDS)2Ge═NPh] decomposes above -30 °C, while [(HMDS)2Ge═NDipp] engages in an intramolecular reaction at 60 °C. [(HMDS)2Ge═NMes] was shown to rearrange via a 1,3-silyl migration to give [(HMDS){(SiMe3)(Mes)N}Ge(NSiMe3)] in a 1:7 equilibrium mixture at room temperature. These latter germanimines react with unsaturated polar substrates such as CO2, ketones, and arylisocyanate via a [2 + 2] cycloaddition pathway.

Surgical repair of a meningoencephalocoele in a kakapo (Strigops habroptilus).

CASE HISTORY: A kakapo (Strigops habroptilus) chick hatched on an off-shore island of New Zealand with a small white mass protruding through the cranial skin of the head. The chick's growth followed a normal pattern for kakapo but at 3 weeks of age the cranium mass was non-reducible and fixed in place and the chick was removed from the island for diagnostic imaging and hand-rearing. CLINICAL FINDINGS AND TREATMENT: A computed tomography (CT) examination revealed a full-thickness circular defect in the central cranium with suspected herniation of brain and dura. Surgery was performed at 37 days of age, and the herniated dura was dissected from the open fontanelle. Attempts to reduce the herniated tissue were unsuccessful, so the herniated dura and cortex were clamped and resected. The dura was closed and the periosteum of the skull was scarified and monofilament polypropylene mesh was secured tautly over the fontanelle. The mesh graft was infused with autologous bone marrow harvested from the ulna in an attempt to stimulate osteogenesis in the mesh repair. The skin flap was then closed. Post-operative recovery and healing were without complication. A CT examination 4 weeks after surgery showed no recurrence of the hernia, and a composite of mesh and scar over the open fontanelle which had reduced in diameter. The chick was released back onto an off-shore island with a radio transmitter and it continues to be monitored regularly. PATHOLOGICAL FINDINGS: The tissue resected at surgery consisted of a cylindrical core of cerebral parenchyma overlain by a mildly hyperplastic epidermis, and large amounts of oedematous fibrovascular tissue arising from the leptomeninges. DIAGNOSIS: Rostral parietal meningoencephalocoele. CLINICAL RELEVANCE: This is the first report of successful surgical resolution of a meningoencephalocoele in any bird. Techniques from human neurosurgery were adapted for the unique anatomical features of the avian skull. The risks of the procedure included increased intra-cranial pressure resulting in anaesthetic complications or death, cerebrospinal fluid leakage, meningitis or recurrence of the meningoencephalocoele. In the longer term, there was a risk of developmental deficits in cognition or behaviour. None of these complications eventuated in the short to medium term, probably due to the small size of the meningoencephalocoele.

Research Note: Comparison of chicken blood chemistry and electrolyte parameters between the portable i-STAT1 clinical analyzer and VetScan VS2 serum biochemistry panel using Hy-Line commercial white-egg laying hens.

The i-STAT1 clinical analyzer has become an increasingly popular tool in clinical production animal medicine as it can provide pen-side results in a cost effective and timely manner when compared to standard benchtop serum biochemistry blood gas and chemistry analyses. This study compares the results of the portable Abbott i-STAT1 analyzer and the Abaxis VetScan VS2 for glucose (Glu, mg/dL), ionized Ca (mmol/L), Na (mmol/L), and K (mmol/L) values. Three genetically distinct commercial varieties (CV) of Hy-Line white-egg laying hens are used in this study (Hy-Line W-36, Hy-Line W-80, and Hy-Line W-80+). Thirty blood samples (n = 10 per CV) were obtained in the production house from the brachial vein and concurrently analyzed by the i-STAT1 portable device. Serum from 22 of these same samples was analyzed via VetScan VS2, a benchtop serum clinical biochemistry analyzer, using VetScan Avian/Reptilian Profile Plus reagent rotors. A paired T-test was used to test for statistical differences in means between the 2 instruments for each of the parameters. Parameters with significant mean differences were then subject to correlation and regression analysis to further evaluate relationships between the results from the 2 methods. Significant differences between means were found for Glu, Na, and K levels. Ca levels were found to be not directly comparable by the 2 analysis instruments. This comparison elucidates the importance of clinical analyzer validations when applying different strategies of diagnostic medicine in poultry.

Accuracy of genomic prediction of shell quality in a White Leghorn line.

Several genomic methods were applied for predicting shell quality traits recorded at 4 different hen ages in a White Leghorn line. The accuracies of genomic prediction of single-step GBLUP and single-trait Bayes B were compared with predictions of breeding values based on pedigree-BLUP under single-trait or multitrait models. Breaking strength (BS) and dynamic stiffness (Kdyn) measurements were collected on 18,524 birds from 3 consecutive generations, of which 4,164 animals also had genotypes from an Affymetrix 50K panel containing 49,591 SNPs after quality control edits. All traits had low to moderate heritability, ranging from 0.17 for BS to 0.34 for Kdyn. The highest accuracies of prediction were obtained for the multitrait single-step model. The use of marker information resulted in higher prediction accuracies than pedigree-based models for almost all traits. A genome-wide association study based on a Bayes B model was conducted to detect regions explaining the largest proportion of genetic variance. Across all 8 shell quality traits analyzed, 7 regions each explaining over 2% of genetic variance and 54 regions each explaining over 1% of genetic variance were identified. The windows explaining a large proportion of genetic variance overlapped with several potential candidate genes with biological functions linked to shell formation. A multitrait repeatability model using a single-step method is recommended for genomic evaluation of shell quality in layer chickens.

Advances in methodologies for detecting MHC-B variability in chickens.

The chicken major histocompatibility B complex (MHC-B) region is of great interest owing to its very strong association with resistance to many diseases. Variation in the MHC-B was initially identified by hemagglutination of red blood cells with specific alloantisera. New technologies, developed to identify variation in biological materials, have been applied to the chicken MHC. Protein variation encoded by the MHC genes was examined by immunoprecipitation and 2-dimensional gel electrophoresis. Increased availability of DNA probes, PCR, and sequencing resulted in the application of DNA-based methods for MHC detection. The chicken reference genome, completed in 2004, allowed further refinements in DNA methods that enabled more rapid examination of MHC variation and extended such analyses to include very diverse chicken populations. This review progresses from the inception of MHC-B identification to the present, describing multiple methods, plus their advantages and disadvantages.

The "Metallo"-Diels-Alder Reactions: Examining the Metalloid Behavior of Germanimines.

Addition of MesN3 (Mes=2,4,6-Me3 C6 H2 ) to germylene [(NONtBu )Ge] (NONtBu =O(SiMe2 NtBu)2 ) (1) gives germanimine, [(NONtBu )Ge=NMes] (2). Compound 2 behaves as a metalloid, showing reactivity reminiscent of both transition metal-imido complexes, undergoing [2+2] addition with heterocumulenes and protic sources, as well as an activated diene, undergoing a [4+2] cycloaddition, or "metallo"-Diels-Alder, reaction. In the latter case, the diene includes the Ge=N bond and π-system of the Mes substituent, which is reactive towards dienophiles including benzaldehyde, benzophenone, styrene, and phenylacetylene.

Utilising an anilido-imino ligand to stabilise zinc-phosphanide complexes: reactivity and fluorescent properties.

A series of zinc complexes bearing the anilido-imino ligand [(o-C6H4{N(C6H3iPr2)}{C(CH3) = NC6H3iPr2})] [(LDipp)ZnX] has been generated. This includes two amide derivatives, [(LDipp)Zn(N{SiMe3}2)] and [(LDipp)Zn(NH{Dipp})] and two phosphanide derivatives, [(LDipp)ZnPCy2] and [(LDipp)ZnPPh2]. The chemistry of the phosphanide complexes towards chalcogens was examined, with sulfur, selenium and tellurium oxidising the phosphorus centre of the dicylohexylphosphanide complex [(LDipp)ZnPCy2] to form [(LDipp)Zn(E)2PCy2] (E = S, Se, Te). Addition of tellurium to the diphenylphosphanide complex [(LDipp)ZnPPh2] results in formation of Ph2PPPh2 and [(LDipp)ZnTeZn(LDipp)]. The absorption and emission properties of these complexes was examined and the quantum yields are highly dependent upon the non-ancillary ligand X.

Synthesis of Bioactive Side-Chain Analogues of TAN-2483B.

The fungal metabolite TAN-2483B has a 2,6-trans-relationship across the pyran ring of its furo[3,4-b]pyran-5-one core, which has thwarted previous attempts at its synthesis. We have now developed a chiral pool approach to this core and prepared side-chain analogues of TAN-2483B. The synthesis relies on ring expansion of a reactive furan ring-fused dibromocyclopropane and alkynylation of the resulting pyran. The furan ring is constructed by palladium-catalysed carbonylative lactonisation. Various side-chains are appended through Wittig-type chemistry. The prepared analogues showed micromolar activity towards cancer cell lines HL-60, 1A9 and MCF-7 and certain human disease-relevant kinases, including Bruton's tyrosine kinase (Btk).

Establishment of Hy-Line commercial laying hen whole blood gas and biochemistry reference intervals utilizing portable i-STAT1 clinical analyzer.

Blood gas and biochemistry reference intervals were established for 3 genetically distinct commercial varieties (CVs) of Hy-Line laying hens: 2 brown-egg layers (Hy-Line Brown, Hy-Line Silver Brown) and a tint-egg layer (Hy-Line Sonia) utilizing the i-STAT1 analyzer. Each respective variety of laying hen was sampled on a replicate cycle of 2 wk for a total of 6 replicates (35 to 46 wk of age). Blood samples were obtained in the production house from the brachial vein, and subsequently analyzed by the i-STAT1 portable device. i-STAT1 clinical analyzer reports blood gas and biochemistry values for the following parameters: pH, partial pressure of carbon dioxide (pvCO2, mm Hg), partial pressure of oxygen (pvO2, mm Hg), bicarbonate (HCO3, mmol/L), base excess (BE, mmol/L), saturation of oxygen on hemoglobin (sO2%), glucose (Glu, mg/dL), sodium (Na, mmol/L), potassium (K, mmol/L), total concentration of carbon dioxide (TCO2, mmol/L), ionized calcium (iCa, mmol/L), hematocrit (Hct % packed cell volume [PCV]), hemoglobin (Hb, g/dL). A total of 1,800 individual hen i-STAT1 records were utilized in the establishment of reference interval values for the 13 parameters between the 3 CVs. Statistical analysis via ANOVA and Tukey's test revealed significant line differences for all 13 blood gas and chemistry parameters measured, with particularly interesting results in iCa. The blood gas and chemistry parameters collected in this study will serve as reference intervals to set the framework for potential future correlations to genetic markers, physiological abnormalities, and production performance.

Investigating the genetic determination of clutch traits in laying hens.

Clutch traits were proposed as a more detailed description of egg-laying patterns than simple total egg production. In this study, egg production of 23,809 Rhode Island Red (RIR) and 22,210 White Leghorn (WL) hens was described in terms of number of clutches, average and maximum clutch size, age at first egg, total saleable egg production, and percentage of egg defects. Genetic parameters were estimated using a six-trait animal model. Of the phenotyped birds, 1433 RIR hens and 1515 WL hens were genotyped with line specific 50K Affymetrix Axiom single nucleotide polymorphism chips to perform genome-wide association analyses. Moderate heritabilities were estimated for clutch traits of 0.20 to 0.42 in the RIR line and 0.29 to 0.41 in the WL line. Average and maximum clutch size was positively genetically correlated with total saleable egg number in both lines. Genome-wide association analysis identified seven regions that were associated with egg production in the RIR line and 12 regions in the WL line. The regions identified were line and trait specific, except for one region on chromosome 6 from 28 to 29 Mb that influenced number of clutches and maximum and average clutch size in WL hens. Regions associated with egg production identified here overlapped with 260 genes, with some strong positional candidates based on gene ontology including WASH1, which is involved in oocyte maturation, NPVF, involved in regulation of follicle-stimulating hormone secretion, and FOXO3, involved in oocyte maturation and ovulation from the ovarian follicle. Confirmation of the role of these genes in regulation of egg production pattern will require further studies.

Genome wide association study for heat stress induced mortality in a white egg layer line.

High environmental temperature is a serious stress affecting economic and biological efficiency of poultry production in tropical and subtropical countries that is expected to become more prominent with global climate change. Iowa experienced 3 acute heat waves of 11, 3, and 4 d of heat index above 38°C in the summer of 2012, which led to production losses and increased bird mortality. For the current study, the proportion of daughters that died from heat stress during this period was calculated for 118 sire families of an elite White Leghorn layer line. The number of daughters per sire ranged from 25 to 111 and averaged 68. Average mortality due to heat stress was 8.2%, ranging from 0 to 24.6%. All sires were genotyped using a 600 K Affymetrix chip. After stringent quality filtering (clustering quality, parentage, missing genotypes, MAF) 113,344 SNPs were retained for the analysis. Method BayesB with π equal to 0.999, for the number of markers fitted not to exceed the number of observations, was applied. Markers explained 8% of the phenotypic variance. One 1-Mb window on chromosome 5 explained 1.2% of genetic variance. When the number of daughters was fitted as a weight in the analysis, the proportion of variance explained by markers dropped to 1%, but 9 1-Mb windows explained more than 1% of genetic variance on chromosomes 1, 3, 5 (the same top window as in the unweighted analysis), 9, 17, and 18. Although the support of the genomic regions associated with heat stress resistance identified in this study was not very strong, they overlapped with previously reported quantitative trait loci regions for immune response and physiological traits in chickens and contained genes that have been associated with response to heat stress in other studies. Further research is needed to validate the results.

Unraveling the spectral signatures of solvent ordering in K-edge XANES of aqueous Na.

The aqueous solvation structure of the Na+ ion is studied both by molecular dynamics (MD) simulations and K-edge X-ray absorption near edge spectroscopy (XANES). We present a systematic study contrasting the differences in the predicted XANES spectra, using molecular configurations generated from classical and quantum MD. Using a set of suitable order parameters, we elucidate how the spectroscopic features are influenced by the local solvation structure around the Na+ ion. Our findings suggest that XANES is sensitive to fluctuations between the first and second solvation shells and can distinguish between classical and quantum interaction representations used to generate molecular ensembles.

Network Analysis: A Systems Framework to Address Grand Challenges in Plant Pathology.

Plant pathology must address a number of challenges, most of which are characterized by complexity. Network analysis offers useful tools for addressing complex systems and an opportunity for synthesis within plant pathology and between it and relevant disciplines such as in the social sciences. We discuss applications of network analysis, which ultimately may be integrated together into more synthetic analyses of how to optimize plant disease management systems. The analysis of microbiome networks and tripartite phytobiome networks of host-vector-pathogen interactions offers promise for identifying biocontrol strategies and anticipating disease emergence. Linking epidemic network analysis with social network analysis will support strategies for sustainable agricultural development and for scaling up solutions for disease management. Statistical tools for evaluating networks, such as Bayesian network analysis and exponential random graph models, have been underused in plant pathology and are promising for informing strategies. We conclude with research priorities for network analysis applications in plant pathology.