Cedrus libani (A. Rich) distribution in Lebanon: Past,present and future

Long-term vegetation studies are needed to better predict the impact of future climate change on vegetation structure and distribution. According to the IPCC scenario, the Mediterranean region is expected to undergo significant climatic variability over the course of this century. Cedrus libani (A. Rich), in particular, is currently distributed in limited areas in the Eastern Mediterranean region, which are expected to be affected by such climate change. In order to predict the impact of future global warming, we have used fossil pollen data and model simulations. Palaeobotanical data show that C. libani has been affected by both climate change and human activities. Populations of C. libani survived in refugial zones when climatic conditions were less favourable and its range extended during periods of more suitable climate conditions. Simulations of its future geographical distribution for the year 2100 using a dynamic vegetation model show that only three areas from Mount Lebanon may allow its survival. These results extrapolated for cedar forests for the entire Eastern Mediterranean region show that forests in Syria are also threatened by future global warming. In southern Turkey, cedar forests seem to be less threatened. These results are expected to help in the long-term conservation of cedar forests in the Near East.     

When the political becomes personal: Reflecting on disability bioethics

A discussion of the connection between activism and academia in bioethics, highlighting the author’s own trajectory, exploring the extent to which academics have an obliation to be ‘judges’ rather than ‘barristers’ (as explored by Jonathan Haidt) and asking questions about the relationship of disability to positions in bioethics.     

Ethnic mobilization and the state: the Roma in Eastern Europe

The political mobilization of marginalized ethnic groups is a process indispensable for the realization of their political objectives. This article identifies the key criteria and conditions that promote and impede successful ethnic mobilization and analyses the determinants of state policy towards newly mobilizing ethnic minorities. The theoretical arguments receive empirical support from the findings of a comparative study of the Romani (Gypsy) minority in seven East European states.     

Immunoreactive and bioactive somatostatin-like material is present in tobacco (Nicotiana tabacum)

Immunoreactive and biologically active somatostatin-like material is present in extracts of tobacco plants (Nicotiana tabacum). Comparative chromatographic and immunological characterization of this peptide along with synthetic (hypothalamic-like) somatostatin-14 and -28, indicates that both molecular forms are present in the plant. Tobacco-somatostatin inhibits the prostaglandin E2-induced release of growth hormone from cultured anterior pituitary cells. This finding raises questions concerning the evolutionary mechanisms responsible for the presence of this neuropeptide in plants, and the physiological significance of this phenomena.     

(AT)n is an interspersed repeat in the Xenopus genome.

We have observed (AT)34 and (AT)23 tracts close to the coding sequences of the Xenopus laevis tadpole alpha T1 and adult beta 1 globin genes, respectively. We show that (AT)n sequences are found as interspersed repeats within the Xenopus globin and histone gene loci. Using (AT)n co-polymer in filter hybridisation experiments we estimate that there are 10(4) (AT)n tracts per haploid Xenopus genome. Hybridisation to genomic blots of DNA from yeast, slime mold, trypanosome, fruit fly, salmon, chicken, rat, human, crab and Xenopus species shows that strictly alternating AT of sufficient length to hybridise appears to be most abundant in Xenopus and crab genomes. We show that the specificity of the co-polymer probe for strictly alternating AT is, however, dependent on the length of the probe. Hybridisation experiments using (TG)n copolymer suggest that this highly conserved repeat is found as clustered repeats in the Xenopus genome in contrast to other eukaryotic genomes so far studied.     

Distribution and flower visitation records of bumblebees in Lebanon (Hymenoptera: Apidae)

Summary

West Palearctic bumblebees are common wildflowers and crop pollinators that are well studied in their central and northern distribution ranges, but fewer information is available on their southern distribution areas. Lebanon falls on the southern limit of their distribution and no published information is available on the local bumblebees. Our study aims to produce a data baseline of the local bumblebee species. In order to do so we grouped available old records of bumblebees in Lebanon with recent author collections and produced preliminary distribution maps. We listed four species: Bombus terrestris, B. argillaceus, B. niveatus vorticosus and B. melanurus. Preliminary distribution shows that Bombus terrestris and B. argillaceus are widespread and have a large foraging range, whereas B. niveatus vorticosus and B. melanurus have a restricted distribution to altitudes above 1800 m with a smaller foraging range. The male cephalic labial gland secretions analysis of local Bombus terrestris specimens provides preliminary evidence that the local subspecies could be Bombus terrestris calabricus. Therefore, we highlight the importance of regulating foreign Bombus terrestris subspecies importation for agriculture purposes, as well as monitoring B. niveatus vorticosus and B. melanurus that are rendered vulnerable by their isolated populations.     

The species identity and biogeography of Blanus (Amphisbaenia: Blanidae) in Lebanon

The genus Blanus Wagler, 1830 represents limbless, burrowing reptiles of the family Blanidae with disjunct circum-Mediterranean distribution. The recently described species Blanus alexandri Sindaco, Kornilios, Sacchi & Lymberakis, 2014 is known from south-eastern Turkey with a presumed occurrence in the Levant and Iraq. We provide here records from Lebanon and confirm the affiliation of Lebanese populations to this species by mitochondrial and nuclear DNA. Blanus alexandri comprises at least seven deeply evolved phylogenetic clades with up to 11% of uncorrected p-distances in their mitochondrial DNA. This suggests a probably older than the Miocene origin of some of these clades. Populations from Lebanon form a different clade with a genetic diversity that is close to populations from southern Turkey.     

Characterization of divalent cation localization in the minor groove of the A(n)T(n) and T(n)A(n) DNA sequence elements by (1)H NMR spectroscopy and manganese(II)

The localization of Mn(2+) in A-tract DNA has been studied by (1)H NMR spectroscopy using a series of self-complementary dodecamer oligonucleotides that contain the sequence motifs A(n)(n) and T(n)A(n), where n = 2, 3, or 4. Mn(2+) localization in the minor groove is observed for all the sequences that have been studied, with the position and degree of localization being highly sequence-dependent. The site most favored for Mn(2+) localization in the minor groove is near the 5'-most ApA step for both the T(n)A(n) and the A(n)T(n) series. For the T(n)A(n) series, this results in two closely spaced symmetry-related Mn(2+) localization sites near the center of each duplex, while for the A(n)T(n) series, the two symmetry-related sites are separated by as much as one half-helical turn. The degree of Mn(2+) localization in the minor groove of the T(n)A(n) series decreases substantially as the AT sequence element is shortened from T(4)A(4) to T(2)A(2). The A(n)T(n) series also exhibits length-dependent Mn(2+) localization; however, the degree of minor groove occupancy by Mn(2+) is significantly less than that observed for the T(n)A(n) series. For both A(n)T(n) and T(n)A(n) sequences, the 3'-most AH2 resonance is the least broadened of the AH2 resonances. This is consistent with the observation that the minor groove of A-tract DNA narrows in the 5' to 3' direction, apparently becoming too narrow after two base pairs for the entry of a fully hydrated divalent cation. The results that are reported illustrate the delicate interplay that exists between DNA nucleotide sequence, minor groove width, and divalent cation localization. The proposed role of cation localization in helical axis bending by A-tracts is also discussed.     

Acid invertase (sucrose hydrolysis) is not required for sucrose mobilization from the vacuole

The possible involvement of acid invertase (sucrose hydrolysis) as a prerequisite for sucrose mobilization from the vacuole of storage cells was investigated. Sugarcane ( Saccharum officinarum ) stalks, carrot ( Daucus carota ) roots and red beet ( Beta vulgaris ) hypocotyls were planted under greenhouse conditions and allowed to resume growth. The plants, however, were not permitted to become photosynthetically autotrophic by removing the new expanded leaves. Sucrose levels declined significantly in all three tissues without the development of acid invertase (EC 3.2.1.26) during the 21‐day experimental period. Acid invertase and thus sucrose hydrolysis within the vacuole was, therefore, not required for sucrose mobilization.     

The copepod genus Oncaea (Poecilostomatoidea) from the Lebanon: taxonomic and ecological observations

Eighteen species of the genus Oncaea, four of them polymorphic,have been collected from the inshore and offshore waters ofthe Lebanon. Three species are new additions to the Mediterraneanfaunal list, O.shmelevi, O.pumilis and O.rufa. The males ofthree poorly described species, O.bathyalis, O.ovalis and O.similis,the female of O.shmelevi and both sexes of O.tenella are redescribed.Oncaea media and O.mediterranea were the two most common representativesof the genus in the study area. Oncaea were most abundant inDecember and January and between March and May; they were mainlymesopelagic and oceanic. Many of the species recorded here havecosmopolitan distributions; some of the smaller ones are lesswell-known, but may prove in time to be as widespread as thelarger taxa.     

The Iranian vole Microtus irani occurs in Lebanon (Mammalia: Rodentia)

We studied 1140 bp cytochrome b sequences of social voles from three localities in Lebanon. The results were compared with published sequences representing seven species of social voles. New sequences from Lebanon clustered with reference samples of two species: M. guentheri and M. irani. While M. guentheri was already reported for Lebanon, M. irani is a new addition to the fauna of Lebanon, and the third known record for the species. Animals were collected in two localities above Tripolis at 855 m and 1430 m a.s.l., respectively.     

The receptor of calcitonin gene-related peptide (CGRP) is present on the membranes of insulinoma

We demonstrate here that membranes prepared from beta cells which release insulin contain specific binding sites for calcitonin gene-related peptide (CGRP). The binding of 125I(His) human CGRP to beta cell membranes was protein concentration, time, temperature and pH dependent. Scatchard analysis of the data revealed a single class of binding sites with an apparent dissociation constant (Kd) of 1.5 nM and a maximal binding capacity of 19 fmol/mg of protein. Chicken CGRP inhibited the label binding whereas salmon calcitonin had only a weak effect. These results suggest that the effect of CGRP on insulin secretion is due to a direct action on beta cells.     

Evidence that epidermal growth factor is present in swiftlet's (Collocalia) nest

1. An epidermal growth factor (EGF)-like activity was detected and partially purified from swiftlet's nest extract. 2. The partially purified EGF-like activity was able to (a) generate competitive binding curves parallel to the standard curves in radioreceptor assay and (b) stimulate thymidine incorporation in quiescent culture of 3T3 fibroblasts and the latter activity can be suppressed by mouse EGF antibody. 3. Partial characterization of the EGF-like activity in terms of pI, molecular weight and its behavior on gel filtration column suggest that it bears similar physical properties to the EGFs isolated from the mouse and the shrew.