Does Height Off the Ground Affect Bird Visitation and Fruit Set in the Pollen‐Limited Mistletoe Peraxilla tetrapetala (Loranthaceae)?

For pollination studies of forest species it is sometimes only possible to work on those flowers nearest to the ground. We test whether using low flowers introduces bias, by measuring height effects on bird visitation and fruit set in one mistletoe species pollinated by bellbirds in New Zealand. At this site, previous studies have shown fruit set near the ground to be pollen limited. We measured fruit set on 32 mistletoes at different heights in 11 host trees. Mistletoe fruit set varied significantly among host trees but did not vary with height. Although bellbirds generally forage preferentially in the upper part of the forest, mistletoe flowers appear to be attractive enough to ensure adequate visitation and fruit set at all heights.     

Classification and ordination of plant communities along an altitudinal gradient on the Presidential Range,New Hampshire,USA

An analysis of vegetation along an altitudinal gradient on the Presidential Range, New Hampshire, USA, using the Braun–Blanquet approach followed by multivariate data analysis is presented. Twelve main plant communities have been distinguished. Floristic information is presented in twelve tables and one appendix. The relationships of the communities to complex environmental gradients are analyzed using Correspondence Analysis. Floristic composition and community structure are controlled primarily by the altitudinal gradient (temperature, precipitation), and by mesotopographic conditions (snow accumulation, exposure and cryoturbation, slope position, and soil moisture).     

The effect of strepsipteran parasitism on a tettigoniid pest of oil palm in Papua New Guinea

Abstract. A study was undertaken to assess the impact of the strepsipteran endoparasite Stichotrema dallatorreanum Hofeneder on the performance of its host Segestidea novaeguineae (Brancsik), a tettigoniid pest of oil palm in Papua New Guinea. This involved analyses of morphology, gut contents, body composition and reproductive variables of field-collected adults of stylopized and unstylopized hosts. The morphological consequences of stylopization by S. dallatorreanum included reduced wing, ovipositor and digestive tract lengths, whereas antennal length was largely unaffected. Feeding activity by the host, as estimated indirectly through weighing gut contents, was significantly reduced in parasitised female hosts, whereas smaller males showed no effect. Parasitized hosts had a reduced carcass dry weight associated with reduced nitrogen content and a substantial decline in carcass lipid content. Host reproductive variables were profoundly affected by stylopization. In females this included impaired ovarian development, reduced egg number and gonadal weight, the last of which was also reduced in males. There was an association between the number of S. dallatorreanum present (maximally six in males and nine in females) within a host and the extent of the impact of stylopization on most of the host characters investigated. The ability of S. dallatorreanum to reduce feeding and reproduction in the host suggests it may have potential use as a bio-control agent in the management of tettigoniid pests in Papua New Guinea.     

Cell wall polysaccharides are informative in Porphyra species taxonomy

As part of systematic studies of the genus Porphyrain New Zealand, constituent sugar analyses of cell wall polysaccharidesin situ in dry thalli were found to yield data that weretaxonomically informative. Variation in constituent sugar levels betweenspecieswas sufficient in some cases to be useful in species differentiation. Thereproductive state of thallus regions had a significant impact on the levels ofconstituent sugars, whereas storage of dried thalli for eight months had noeffect. Three epiphytic taxa currently classified as species ofPorphyra appear to be incorrectly placed within the genus,as their constituent sugars and the levels of these sugars differed markedlyfrom those of all other species examined.     

Locomotor behavior and skeletal morphology of two sympatric pitheciine monkeys,Pithecia pithecia and Chiropotes satanas

Field observations of two sympatric pitheciine species reveal that the positional repertoire of the white-faced saki, Pithecia pithecia, is dominated by leaping behaviors, whereas the bearded saki, Chiropotes satanas, is predominantly quadrupedal. Examination and comparison of the postcranial skeletal morphologies and limb proportions of these species display numerous features associated with their respective locomotor behaviors. These observations accord with associations found in other primate and mammalian groups and with predictions based on theoretical and experimental biomechanics. Preliminary observations of the skeletal morphology of Cacajao calvus demonstrate a marked similarity to that of Chiropotes. The fossil platyrrhine Cebupithecia sarmientoi displays greater similarity to Pithecia, suggesting that its positional repertoire also included significant leaping and clinging behaviors.     

AVPR1b variation and the emergence of adaptive phenotypes in Platyrrhini primates

Platyrrhini (New World monkeys, NWm) are a group of primates characterized by behavioral and reproductive traits that are otherwise uncommon among primates, including social monogamy, direct paternal care, and twin births. As a consequence, the study of Platyrrhine primates is an invaluable tool for the discovery of the genetic repertoire underlying these taxon‐specific traits. Recently, high conservation of vasopressin (AVP) sequence, in contrast with high variability of oxytocin (OXT), has been described in NWm. AVP and OXT functions are possible due to interaction with their receptors: AVPR1a, AVPR1b, AVPR2, and OXTR; and the variability in this system is associated with the traits mentioned above. Understanding the variability in the receptors is thus fundamental to understand the function and evolution of the system as a whole. Here we describe the variability of AVPR1b coding region in 20 NWm species, which is well‐known to influence behavioral traits such as aggression, anxiety, and stress control in placental mammals. Our results indicate that 4% of AVPR1b sites may be under positive selection and a significant number of sites under relaxed selective constraint. Considering the known role of AVPR1b, we suggest that some of the changes described here for the Platyrrhini may be a part of the genetic repertoire connected with the complex network of neuroendocrine mechanisms of AVP–OXT system in the modulation of the HPA axis. Thus, these changes may have promoted the emergence of social behaviors such as direct paternal care in socially monogamous species that are also characterized by small body size and twin births.     

New Mesozoic and early Cenozoic spicular Nassellaria and Nassellaria-like Radiolaria

This paper continues a former study (Rev. Española Micropaleontol. 14 (1982b) 401), where the author described spicular nassellarian and entactinarian Radiolaria found in the Middle Triassic samples available at that time. Based on the study of new samples bearing well preserved radiolarians collected during the 20 years that followed the former publication, samples coming from Triassic, Jurassic, Cretaceous, and Paleogene deposits, the author found that spicular Nassellaria are extremely rare in the post-Fassanian radiolarian faunas. Their fossil record is punctuated, their occurrences being separated by very long gaps. And even so, when they occur their number is usually reduced to one, two, or several specimens of a single species. Spicular Nassellaria are rare or very rare in the upper Spathian and Anisian, frequent in the upper Anisian-lower Ladinian, practically absent in the upper Ladinian and the whole upper Triassic and pre-Toarcian Lower Jurassic, rare in lower Toarcian, very rare in the Bajocian, rare in the lower Tithonian. No specimens were recorded in the other stages of the middle and upper Jurassic and in the whole Cretaceous, except for one in the Coniacian. In the Paleogene only five species belonging to four genera have been recorded in the upper Paleocene-middle Eocene. In the Neogene the only genus known so far is Neosemantis that occurs sporadically since the lower Miocene. A wider diversity is recorded in the living plankton or Recent sediments that comprise all genera and species described in the literature before 1970. It is suggested that this scarcity reflects their real scarcity in the tropical or subtropical seas of the past, but this scarcity was probably magnified by selective preservation. The idea of origination of spicular Nassellaria once or several times from shell-bearing Nassellaria by the reduction of shell during some environmental crises of the Mesozoic and Cenozoic or by hybridization is rejected because the group is rather unitary in its spicular structure and it shows a certain evolution from taxa with massive spines to taxa with three-bladed spines. Nassellarian-like spicular Radiolaria range within the boundaries of the Triassic; they seem to have disappeared by the end on the Norian.In order to give a complete inventory of these radiolarians all taxa known in the Mesozoic and lower Cenozoic are described, discussed, or just mentioned. They comprise 44 species of which 20 are new, 14 genera of which six are new (Palaeosemantis, Molzaxis, Daniplagia, Verticiplagia, Jeanpierria and Nandartia), three subfamilies of which one (Zaldacriinae) is new, and two families (Plagiacanthidae and Archaeosemantidae).     

A novel potent metal-binding NDM-1 inhibitor was identified by fragment virtual,SPR and NMR screening

NDM-1 can hydrolyze nearly all available β-lactam antibiotics, including carbapenems. NDM-1 producing bacterial strains are worldwide threats. It is still very challenging to find a potent NDM-1 inhibitor for clinical use. In our study, we used a metal-binding pharmacophore (MBP) enriched virtual fragment library to screen NDM-1 hits. SPR screening helped to verify the MBP virtual hits and identified a new NDM-1 binder and weak inhibitor A1. A solution NMR study of ¹⁵N-labeled NDM-1 showed that A1 disturbed all three residues coordinating the second zinc ion (Zn2) in the active pocket of NDM-1. The perturbation only happened in the presence of zinc ion, indicating that A1 bound to Zn2. Based on the scaffold of A1, we designed and synthesized a series of NDM-1 inhibitors. Several compounds showed synergistic antibacterial activity with meropenem against NDM-1 producing K. pneumoniae.