A test of vegetation–environment relationship in serpentine soils of Tuscany, Italy

The present study evaluates the relative importance of environmental factors in affecting the species composition and abundance of the plant communities on ultramafic soils in Tuscany, Italy. We used rigorous sampling techniques to test hypotheses generated from exploratory studies performed previously. Vegetation–environmental relationships were analyzed using 50 plots, each 1 m², randomly located throughout a 22-ha area in the Upper Tiber Valley. We confirm that the exchangeable fraction of nickel in the soil is almost never high enough to affect the vegetation. However, physical factors (e.g. substrate setting and elevation) are important in controlling the distribution of plant species. Tree cover (almost exclusively due to the introduced plantation pines) also had a significant affect on the vegetation composition and on soil features such as the C/N ratio. Other important factors significantly related to the gradients in vegetation composition (e.g. rockiness and total soil nitrogen) are interpreted as factors related to the vegetation composition through a positive feedback mechanism.     

High β diversity in the flora of Californian serpentine 'islands'

Identification of global biodiversity hotspots is a leading conservationpriority ( Hotspots.Conservation International, Washington, DC; Precious Heritage: The Statusof Biodiversity in the United States. Oxford University Press, Oxford, UK), but weknow little about the nature and structure of such hotspots. Botanical richnessin one recently identified hotspot, the California Floristic Province, has longbeen attributed by evolutionists to edaphic and climatic heterogeneity. Here we demonstrate that the flora restricted (endemic) toserpentine soil, the state's most botanically distinctive substrate, showsunusually high ' diversity' – i.e., spatial variation inspecies composition – among regions, although ''diversity within any given region is low. Conservation of an endemic-rich florarequires a network of sites to capture this among-region or spatial component ofdiversity.     

Theoretical descriptions of novel triplet germylenes M<Subscript>1</Subscript>-Ge-M<Subscript>2</Subscript>-M<Subscript>3</Subscript> (M<Subscript>1</Subscript> = H,Li, Na,K; M<Subscript>2</Subscript> = Be,Mg, Ca; M<Subscript>3</Subscript> = H,F, Cl,Br)

In a quest to identify new ground-state triplet germylenes, the stabilities (singlet–triplet energy differences, ΔE_S–T) of 96 singlet (s) and triplet (t) M₁-Ge-M₂-M₃ species were compared and contrasted at the B3LYP/6–311++G**, QCISD(T)/6–311++G**, and CCSD(T)/6–311++G** levels of theory (M₁?=?H, Li, Na, K; M₂?=?Be, Mg, Ca; M₃?=?H, F, Cl, Br). Interestingly, F-substituent triplet germylenes (M₃?=?F) appear to be more stable and linear than the corresponding Cl- or Br-substituent triplet germylenes (M₃?=?Cl or Br). Triplets with M₁?=?K (i.e., the K-Ge-M₂-M₃ series) seem to be more stable than the corresponding triplets with M₁?=?H, Li, or Na. This can be attributed to the higher electropositivity of potassium. Triplet species with M₃?=?Cl behave similarly to those with M₃?=?Br. Conversely, triplets with M₃?=?H show similar stabilities and linearities to those with M₃?=?F. Singlet species of formulae K-Ge-Ca-Cl and K-Ge-Ca-Br form unexpected cyclic structures. Finally, the triplet germylenes M₁-Ge-M₂-M₃ become more stable as the electropositivities of the α-substituents (M₁ and M₂) and the electronegativity of the β-substituent (M₃) increase.     

Au Gravettien, dans la grotte Cosquer (Marseille, Bouches-du-Rhône), l'Homme a-t-il compté sur ses doigts ?

Negative hands, occasionally with incomplete fingers, are often found in Paleolithic caves but so far have received no definitive explanation. Nowadays they are more commonly seen as the expression of a gestural language. In this paper, we suggest that the negative hands visible in the Cosquer cave and dating from around 27?000 BP could represent counting on fingers. Several arguments are developed to support this hypothesis. Furthermore we also suggest that the dots and dashes often associated with negative hands in numerous caves, might be another, more advanced way of representing numbers.     

Plants as extreme environments? Ni-resistant bacteria and Ni-hyperaccumulators of serpentine flora

During recent years there has been an increasing interest in the bacterial communities occurring in unusual, often extreme, environments. On serpentine outcrops around the world, a high diversity of plant species showing the peculiar features of metal hyperaccumulation is present. These metal hyperaccumulators have received much attention for their potential biotechnological exploitation in phytoremediation processes, but also as unusual, extreme habitats for the associated bacterial flora, which could reveal novel details concerning bacterial adaptation. This paper will briefly focus on the research topics that have been addressed to date on bacteria associated with serpentine plants and aims to provide a state of the art and to present possible future directions for research which could lead to new insights on microbial adaptation and evolution, and potentially applied in technologies for sustainable use and remediation of contaminated land.     

Backbone and Ile-δ1, Leu,Val methyl <Superscript>1</Superscript>H, <Superscript>15</Superscript>N,and <Superscript>13</Superscript>C,chemical shift assignments for <Emphasis Type="Italic">Rhizopus chinensis</Emphasis> lipase

Lipase r27RCL is a 296-residue, 33 kDa monomeric enzyme with high ester hydrolysis activity, which has significant applications in the baking, paper and leather industries. The lipase gene proRCL from Rhizopus microsporus var. chinensis (also Rhizopus chinensis) CCTCC M201021 was cloned as a fusion construct C-terminal to a maltose-binding protein (MBP) tag, and expressed as MBP-proRCL in an Escherichia coli BL21 trxB (DE3) expression system with uniform ²H,¹³C,¹⁵N-enrichment and Ile-δ1, Leu, and Val ¹³CH₃ methyl labeling. The fusion protein was hydrolyzed by Kex2 protease at the recognition site Lys-Arg between residues ?29 and ?28 of the prosequence, producing the enzyme form called r27RCL. Here we report extensive backbone ¹H, ¹⁵N, and ¹³C, as well as Ile-δ1, Leu, and Val side chain methyl, NMR resonance assignments for r27RCL.     

Études stratigraphique,sédimentologique et paléomagnétique des travertins de Kocabaş, Bassin de Denizli,Anatolie, Turquie,contenant des restes fossiles quaternaires

Stratigraphic, sedimentological and paleomagnetic studies were conducted on the travertine from Denizli Basin, near Kocabas village, in the Denizli region in Turkey, following the paleontological discovery in 2002. The stratigraphic and sedimentological studies show at least two main cycles of mass travertine, separated by a fluvial deposit and overlain by a fluvio-lacustrine deposit. These travertines must have formed in environments with strong hydrodynamics (streams or waterfalls) and are preferentially located at breaks of slopes. The paleomagnetic study shows that all the quarry travertine presents reverse magnetic polarity. On the other hand, the detrital fluvio-lacustrine deposit above the travertine presents normal geomagnetic polarity, except at the top, where it is reversed. Given the presence of an archaic Homo erectus skull and Villafranchian paleontological remains in the upper travertine unit, the whole travertine dates from the upper Matuyama, and is more recent than the Olduvai event (1.78 Ma). The normal polarity recorded in the upper fluvio-lacustrine deposit could correspond to the Cobb Mountain excursion, dated to 1.22 Ma.     

Electric-field-induced spin switch of endohedral dodecahedrane heterodimers H@C<Subscript>20</Subscript>H<Subscript>n</Subscript>–C<Subscript>20</Subscript>H<Subscript>n</Subscript>@M (M= Cu,Ag and Au,n = 15, 18, and 19): a theoretical study

We designed nine endohedral dodecahedrane heterodimers H@C₂₀H_n-C₂₀H_n@M (M = Cu, Ag, and Au, n = 15, 18, and 19) that may act as single-molecule spin switches, and we predicted theoretically that the ground states of the dimmers shift from low-spin states (S = 0) to the high-spin states (S = 1) under an external electric field applied parallel or perpendicular to the molecular symmetry axes, consisting well with the analyses of Stark effect. Molecular orbitals analyses provide an intuitive insight into the spin crossover behavior. This study expands the application of endohedral chemistry and provides new molecules for designing single-molecule spin switch.     

Effects of activation of μ-, κ<Subscript>1</Subscript>-, δ<Subscript>1</Subscript>-, δ<Subscript>2</Subscript>-, and ORL<Subscript>1</Subscript>-receptors on heart resistance to the pathogenic action of delayed ischemia and reperfusion

Different subtypes of opioid receptors (OR) were activated in rats in vivo to study the activation effect on the heart’s resistance to ischemia and reperfusion. It has been established that administration of deltorphin II, a selective δ₂-OR agonist, lowered the infarct size/area at risk index (IS/AAR) by 23%. Naltrexone, naloxone methiodide (an OR inhibitor not penetrating the blood-brain barrier (BBB)), and naltriben (δ₂-antagonist) eliminated the cardioprotective effect of deltorphin II, while BNTX (a δ₁-antagonist) produced no effect on the cardioprotective action of the δ₂-agonist. The infarct-reducing effect of deltorphin II was eliminated by administration of chelerythrine (a protein kinase C (PKC) inhibitor), glibenclamide (a K_ATP-channels inhibitor), and 5-hydroxydecanoate (a mitochondrial K_ATP-channel blocker). Administration of other opioids did not reduce the IS/AAR index. It has been established that all the deltorphins manifest antiarrhythmic potency. Other opioids do not produce any effect on the incidence of arrhythmia occurrences. The antiarrhythmic effect of deltorphin II was eliminated by preliminary administration of naltrexone, naloxone methiodide, and naltriben, but BNTX did not affect the δ₂-agonist’s anti-arrhythmic effect. The preliminary administration of chelerythrine, a PKC inhibitor, eliminated the δ₂ agonist’s antiarrhythmic action. However, glibenclamide and 5-hydroxydecanoate did not alter the antiarrhythmic effect by deltorphin II. Therefore, activation of the peripheral δ₂-ORs reduces the infarct size and prevents the onset of arrhythmias. The antiarrhythmic effect of the δ₂-OR stimulation is mediated by activating PKC and opening the mitochondrial K_ATP-channels. PKC participates in the antiarrhythmic effect of the δ₂-OR activation, but this effect does not depend on the condition of K_ATP-channels.     

Metal–metal bonding and aromaticity in [M<Subscript>2</Subscript>(NHCHNH)<Subscript>3</Subscript>]<Subscript>2</Subscript> (μ-E)<Subscript>2</Subscript> (E = O,S; M = Nb,Mo, Tc,Ru, Rh)

The nature of M–M bonding and aromaticity of [M₂(NHCHNH)₃]₂(μ-E)₂ (E?=?O, S; M?=?Nb, Mo, Tc, Ru, Rh) was investigated using atoms in molecules (AIM) theory, electron localization function (ELF), natural bond orbital (NBO) and molecular orbital analysis. These analyses led to the following main conclusions: in [M₂(NHCHNH)₃]₂(μ-E)₂ (E?=?O, S; M?=?Nb, Mo, Tc, Ru, Rh), the Nb–Nb, Ru–Ru, and Rh–Rh bonds belong to “metallic” bonds, whereas Mo–Mo and Tc–Tc drifted toward the “dative” side; all these bonds are partially covalent in character. The Nb–Nb, Mo–Mo, and Tc–Tc bonds are stronger than Ru–Ru and Rh–Rh bonds. The M–M bonds in [M₂(NHCHNH)₃]₂(μ-S)₂ are stronger than those in [M₂(NHCHNH)₃]₂(μ-O)₂ for M?=?Nb, Mo, Tc, and Ru. The NICS(1)_ZZ values show that all of the studied molecules, except [Ru₂(NHCHNH)₃]₂(μ-O)₂, are aromaticity molecules. O-bridged compounds have more aromaticity than S-bridged compounds.

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Graphical Abstract Left Molecular graph, and right electron localization function (ELF) isosurface of [M₂(NHCHNH)₃]₂(μ-E)₂(E?=?O, S; M?=?Nb, Mo, Tc, Ru, Rh)

     

Development,optimization, and biovalidation of <Superscript>99m</Superscript>Tc–insulin complex

Human biosynthetic insulin is a polypeptide hormone that plays an important and essential role in control of the level of carbohydrate, protein, and fat metabolism in the blood. Human pancreatic insulin was labeled with ^99mTc to form a new radiopharmaceutical with a labeling yield of 99 ± 1% under optimum conditions: 0.1 mL insulin, pH 7, 25 μg stannous chloride, 1 mL (19 mCi) of pertechnetate, room temperature, and 10 min reaction time. The ^99mTc–insulin complex was examined using paper chromatography, ITLC, electrophoresis, and HPLC. In addition, in vitro and in vivo study of ^99mTc–insulin complex was performed at different time intervals.     

<Superscript>1</Superscript>H, <Superscript>13</Superscript>C,and <Superscript>15</Superscript>N resonance assignments for the pro-inflammatory cytokine interleukin-36α

Interleukin-36α (IL-36α) is a recently characterised member of the interleukin-1 superfamily. It is involved in the pathogenesis of inflammatory arthritis in one third of psoriasis patients. By binding of IL-36α to its receptor IL-36R via the NF-κB pathway other cytokines involved in inflammatory and apoptotic cascade are activated. The efficacy of complex formation is controlled by N-terminal processing. To obtain a more detailed view on the structure function relationship we performed a heteronuclear multidimensional NMR investigation and here report the ¹H, ¹³C, and ¹⁵N resonance assignments for the backbone and side chain nuclei of the pro-inflammatory cytokine interleukin-36α.     

Correction to: Plastome phylogenomics of Allaeanthus,Broussonetia and Malaisia (Dorstenieae,Moraceae) and the origin of B. × kazinoki

Journal of Plant Research -     

Valbro : un nouveau site à vertébrés de l’Oligocène inférieur (MP22) de France (Quercy). I – Contexte géologique ; Mammalia : Rodentia,Hyaenodontida, Carnivora

The locality Valbro (Quercy, France) has yielded a rich fossil vertebrate fauna. Here are presented the geological context, a preliminary faunal list and the systematics of the Rodentia and carnivores, the most abundant taxa of the fauna. The Rodentia are known from 11 taxa: the Theridomyidae Blainvillimys gregarius Schlosser, 1884, Blainvillimys ?gemellus Vianey-Liaud, 1989, Issiodoromys medius (Vianey-Liaud, 1976) and S. cayluxi Schlosser, 1884, the Aplodontidae Plesispermophilus angustidens Filhol, 1882, the Gliridae Butseloglis tenuis (Bahlo, 1975), Butseloglis micio (Misonne, 1957) and Bransatoglis planus (Bahlo, 1975), the Sciuridae Palaeosciurus goti Vianey-Liaud, 1974 and cf. Oligopetes sp., and the Cricetidae Atavocricetodon sp. aff. A. nanus (Pelaez-Campomanes, 1995). Thirteen taxa of carnivores are present at Valbro; among the Hyaenodontida: Hyaenodon leptorhynchus Laizer et Parieu, 1838 and cf. Apterodon sp.; among the Carnivora: a Feliformia gen. et sp. indet., the Nimravidae Nimravus intermedius (Filhol, 1872), Dinailurictis bonali Helbing, 1922 and Nimravidae gen. et sp. indet. (Certainly belonging to one the two already identified species), the Ursida Pachycynodon crassirostris Schlosser, 1888, Pachycynodon sp., Amphicynodon sp. 1 cf. A. typicus (Schlosser, 1888), Amphicynodon ? sp. 2 and Ursida gen. et sp. indet. cf. Pachycynodon boriei (Filhol, 1876), the Mustelida M. olivieri Bonis, 1997, the Carnivora incertae sedis Palaeogale sectoria (Gervais, 1848–1852), the Arctoidea gen. et sp. indet. and Carnivora gen. et sp. indet. (probably representing taxa already identified at lower taxonomic levels). The evolutionary grade of B. gregarius of Valbro compares to that of the species from Mas de Got, La Plante 2 and Cavalé, which supports an MP22 age for Valbro. This datation is further supported by the association of Theridomyinae yielded by the locality (B. gregarius, B. gemellus, I. medius and S. cayluxi), and by the presence of a N. intermedius that well compares the material of the species from Villebramar, La Plante et Mas de Got, of D. bonali, P. sectoria, M. olivieri (species known only from Mas de Got), and by additional evidence from the remaining vertebrates from Valbro, especially the squamates. Despite a limited amount of specimens (341 specimens have been studied), the faunas of rodents and carnivores from Valbro are the most speciose and diverse known for the MP22 level and, for the Carnivora fauna in particular, for the Oligocene of the Old World.     

Revision,cladistic analysis and biogeography of Typhochlaena C. L. Koch, 1850, Pachistopelma Pocock, 1901 and Iridopelma Pocock, 1901 (Araneae,?Theraphosidae,Aviculariinae)

Three aviculariine genera endemic to Brazil are revised. Typhochlaena C. L. Koch, 1850 is resurrected, including five species; Pachistopelma Pocock, 1901 includes two species; and Iridopelma Pocock, 1901, six species. Nine species are newly described: Typhochlaena amma sp. n., Typhochlaena costae sp. n., Typhochlaena curumim sp. n., Typhochlaena paschoali sp. n., Pachistopelma bromelicola sp. n., Iridopelma katiae sp. n., Iridopelma marcoi sp. n., Iridopelma oliveirai sp. n. and Iridopelma vanini sp. n. Three new synonymies are established: Avicularia pulchra Mello-Leitão, 1933 and Avicularia recifiensis Struchen & Brändle, 1996 are junior synonyms of Pachistopelma rufonigrum Pocock, 1901 syn. n., and Avicularia palmicola Mello-Leitão, 1945 is a junior synonym of Iridopelma hirsutum Pocock, 1901 syn. n. Pachistopelma concolor Caporiacco, 1947 is transferred to Tapinauchenius Ausserer, 1871, making the new combination Tapinauchenius concolor (Caporiacco, 1947) comb. n. Lectotypes are newly designed for Pachistopelma rufonigrum Pocock, 1901 , Iridopelma hirsutum Pocock, 1901 and Pachistopelma concolor Caporiacco, 1947. Cladistic analyses using both equal and implied weights were carried out with a matrix comprising 62 characters and 38 terminal taxa. The chosen cladogram found with X-Pee-Wee and concavity 6 suggests they are monophyletic. All species are keyed and mapped and information on species habitat and area cladograms are presented. Discussion on biogeography and conservation is provided.     

Insight into “serpentine syndrome” of Albanian,endemic violets (Viola L., Melanium Ging. section) – Looking for unique,adaptive microstructural floral,and embryological characters

The genus Viola, particularly Melanium section, rich in metallophytes, is an excellent taxon for study of microevolutionary and adaptation processes. Pollen, ovule, and microstructural floral characters were investigated by LM, SEM, and CLSM in seven endemic Albanian violets, five serpentinophytes (Viola albanica, V. dukadjinica, V. albanica × V. dukadjinica, V. raunsiensis, and V. macedonica), two from chalk soil (V. aetolica and V. schariensis), and in their closest relatives (V. lutea ssp. sudetica, V. tricolor ssp. tricolor, and V. arvensis) for their taxonomic usefulness and adaptive value. Three among analyzed characters were common in all Albanian violets however not unique. Serpentinophytes, V. aetolica and V. schariensis possessed hairs deep inside the spur, developed pollen heteromorphism, both increase the chance of pollination in unpredictable conditions and had strongly developed tannin rich layer in the outer integument of the young ovules with a protective role. They also all exhibited high pollen viability (86.9 ± 10.2%), high frequency of normally developed, enlarged (fertilized) ovules in ovary (65.0 ± 24.0%), but also high frequency of degenerations in developing ovules (40.4 ± 9.8%). Several flower characters may be adaptive in the unfavorable, high altitude environment, including serpentine soils. High pollen viability and normally developed fertilized ovules are sufficient for Albanian species maintenance.     

<Emphasis Type="Italic">N</Emphasis>-Methylation of <Emphasis Type="Italic">N</Emphasis><Superscript>α</Superscript>-Acetylated,Fully C<Superscript>α</Superscript>-Ethylated,Linear Peptides

“Mono-N-methyl scan” is a rational approach for the optimization of the peptide biological properties. N-Methylation of the –CONH– functionality is also a useful tool for discriminating solvent exposed from intramolecularly H-bonded secondary amide groups in peptides. We are currently extending this reaction to linear peptides based on C^α-tetrasubstituted α-amino acids. Following our study on the synthesis and conformation of the mono-N-methylated peptides from C^α-methylated residues, in this work we investigated the N-methylation reaction on homo-peptides to the pentamer level from the C^α-ethylated residue C^α,α-diethylglycine. Under the classical experimental conditions used, exclusively mono-N-methylation (on the N-terminal, acetylated residue) takes place, as unambiguously shown by mass spectrometry, 2D-NMR, and X-ray diffraction techniques. This backbone modification does not seem to involve any significant change in the peptide conformation in the crystalline state. Dedicated to the memory of Prof. Miroslav T. Leplawy (Technical University of Łodz, Poland), who performed the first synthesis of the extremely sterically demanding C^α,α-diethylglycine peptides.     

Effect of nitrogen load on growth and photosynthesis of seedlings of the hybrid larch F1 (Larix gmelinii var. japonica × L. kaempferi) grown on serpentine soil

We studied the growth and photosynthesis of the hybrid larch F₁ (Larix gmelinii var. japonica × L. kaempferi) grown on serpentine soil and the effects of soil N load, to determine the performance of this species as reforestation material in serpentine regions. We prepared 16 experimental plots (2 m × 4 m each), eight on serpentine and eight on brown forest soil, and planted one-year-old cutting seedlings of the hybrid larch F₁ in each plot, in May 2007. Ammonium sulfate was supplied to half of the plots of each soil type in 2008 and 2009, at a load of 47 kg N ha⁻¹ year⁻¹. Although the growth and photosynthetic capacity of hybrid larch F₁ seedlings in the serpentine soil were limited, the rate of growth in serpentine soil was greater than that of Sakhalin spruce (Picea glehnii) that is dominant species in serpentine regions. There was significant interaction between soil type and N load for the growth and photosynthetic parameters. The N load adversely affected growth and photosynthetic parameters in the serpentine soil, while improved them in brown forest soil. Although the growth rate of hybrid larch F₁ without N loading showed high potential as an afforestation species in serpentine region, increasing deposition of N might be a threat to the growth and photosynthesis of the hybrid larch F₁ in serpentine soil.