bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hα Emission from the Magellanic Bridge
Authors: Muller E. , Parker Q. A. 
Published: July 2007

AbstractWe present here a preliminary report and commentary of recently processed observations of Hα emission towards the Magellanic Bridge. These data have been analysed in an attempt to quantify the extent to which the stellar population is capable of reshaping the local ISM. We find that the Hα emission regions are small, weak and sparsely distributed, consistent with a relatively quiescent and inactive ISM where radiative and collisional ionisation is inefficient and sporadic. This suggests that energetic processes at the small scale (i.e. ∼tens of pc) do not dominate the energy balance within the ISM of the Bridge, which therefore hosts a pristine turbulent structure, otherwise inaccessible within our own Galaxy. We find Hα emission that is well correlated with detected 12CO(1–0) line emission (a proxy for molecular hydrogen), as well as other easily identified ring-like Hı features.
Observation Scheduling for a Network of Small-Aperture Telescopes
Authors: Duncan A. R. 
Published: July 2007

AbstractOver the past several years, a system for accepting, servicing and returning the results from a large number of imaging requests has been developed for use with automated optical telescopes. One of the primary goals of this project is to increase the accessibility of astronomy to school, college and university students. A key component of this system is a request scheduling engine, which produces schedules for each telescope for its current night. This engine is dynamic, adjusting schedules to accommodate new requests and rescheduling failed requests on a time scale of the order of ten minutes. If a telescope is unavailable for an extended period, imaging requests will be reallocated to other telescopes in the network. Various models of dynamic scheduling are considered, and the current implementation is explored with a number of numerical experiments.
High risk of pituitary dysfunction due to aneurysmal subarachnoid haemorrhage: a prospective investigation of anterior pituitary function in the acute phase and 12 months after the event
Authors: Tanriverdi Fatih , Dagli Ahmet Turan , Karaca Zuleyha , Unluhizarci Kursad , Selcuklu Ahmet , Casanueva Felipe F. , Kelestimur Fahrettin 
Published: July 2007

SummaryObjective  Recent investigations have provided evidence for a high prevalence of pituitary dysfunction in patients with subarachnoid haemorrhage (SAH). However, apart from one study, all of the previous data were obtained from retrospective studies. To our knowledge there is no previously reported study in which pituitary function was investigated in the same patients immediately after SAH and 12 months later. The aim of this study was to understand the prevalence and progression of anterior pituitary hormone deficiencies both in the acute phase of SAH and 12 months after the event.Patients and design  Twenty‐two SAH patients (11 men, 11 women) were included in the study. Pituitary function was evaluated in the early acute phase (within 24 h of admission) and after 12 months.Results  Pituitary hormone deficiencies in the acute phase were as follows: 31·8% had gonadotrophin, 22·7% had ACTH and 22·7% had GH deficiencies. At 12 months after SAH: 0·0% had gonadotrophin, 13·6% had ACTH and 36·4% had GH deficiencies. Overall, after 12 months, pituitary hormone deficiencies recovered in 15 (68·2%) patients and new‐onset pituitary hormone deficiencies were present in nine (40·9%) patients.Conclusions  GH deficiency (GHD) was the most common pituitary deficit at 12 months after SAH and the majority of the patients (87·5%) had isolated GHD. During the 12‐month follow‐up, pituitary function was found to either improve or worsen in a considerable number of patients.
Phylogenetic relationships of the Culicomorpha inferred from 18S and 5.8S ribosomal DNA sequences (Diptera: Nematocera)
Authors: Miller B. R. , Crabtree M. B. , Savage H. M. 
Published: July 2007

AbstractWe investigated the evolutionary origins of the mosquito family Culicidae by examination of 18S and 5.8S ribosomal gene sequence divergence. Phylogenetic analyses demonstrated that within the infraorder Culicomorpha, taxa in the families Corethrellidae, Chaoboridae and Culicidae formed a monophyletic group; there was support for a sister relationship between this lineage and a representative of the Chironomldae. A chaoborid midge was the closest relative of the mosquitoes. Taxa from four genera of mosquitoes formed a monophyletic group; lack of a spacer in the 5.8S gene was unique to members of the Culicidae. A member of the genus Anopheles formed the most basal lineage among the mosquitoes analysed. Phylogenetic relationships were unresolved for representatives in the families Dixidae, Simuliidae and Ceratopogonidae.
Heterogeneity of the internal transcribed spacer (ITS‐2) region within individual deer ticks
Authors: Rich S. M. , Rosenthal B. M. , Telford S. R. , Spielman A. , Harti D. L. , Ayala F. J. 
Published: July 2007

AbstractTo determine whether nuclear rDNA sequences provide a useful means for assessing the structure of populations of Ixodes ticks, we compared variability among copies of an internal transcribed spacer (ITS‐2) sequence within individual ticks to the variability between ticks. At least 4% of the nucleotides comprising this sequence vary among the copies present within individual ticks. ITS‐2 diversity in each of two ticks is nearly half as great as that reported between ticks from geographically disparate populations. Because individual ticks retain ancestral polymorphism, ITS‐2 variation does not accurately reflect descent relationships among these ticks. Sequencing single copies of PCR‐amplified ITS‐2 therefore does not permit assessment of the phylogenetic relationships among the I. ricinus‐like ticks in eastern North America. We recommend caution in future analyses, and emphasize the importance of procedures designed to ensure that the many paralogous coples of the rDNA cistron have been sufficiently homogenized by concerted evolutionary processes. Such precautionary measures will make certain that phylogenetic trees based on these gene sequences reflect the phyletic relatedness of the biological species.
Cloning of cDNAs encoding Bombyx homologues of Cdc2 and Cdc2‐related kinase from eggs
Authors: Iwasaki H. , Takahash M. , Nilmi T. , Yamashita O. , Yaginuma T. 
Published: July 2007

AbstractIn diapausing eggs of the silkworm, Bombyx mori, embryonic cells are arrested at G2 phase. The ability to undertake cell division is resumed in the course of diapause termination caused by such a treatment as acclimation to 5°C. As an initial trial to investigate the relationship between diapause and embryonic cell cycling, we have cloned and sequenced two Bombyx cDNAs encoding two distinct cdc2‐related Ser/Thr protein kinases. One (Bm cdc2) encoded a 37.0 kDa protein which had all of the domains characteristic of other Cdc2 kinases. The other (Bcdrk) encoded a 45.1 kDa protein that was most similar to Drosophila and human cdc2‐related protein kinases (Dcdrk protein and PISSRLE kinase). Northern blot analysis was carried out to examine levels of Bm cdc2 and Bcdrk mRNA during embryogenesis of non‐diapause eggs. The result demonstrated that the mRNA level of Bm cdc2 appeared to correspond to the activity of nuclear/cellular division in non‐diapause eggs, and that the developmental profile in the level of Bcdrk mRNA was somewhat different from that of Bm cdc2 mRNA.
The relative effects of raptor predation and shooting on overwinter mortality of grey partridges in the United Kingdom
Authors: WATSON M , AEBISCHER N. J , POTTS G. R , EWALD J. A 
Published: July 2007

Summary

Factual information is key to resolving conflicts between raptor conservation and gamebird management, especially when the conservation status of one of the species involved is threatened. The grey partridge Perdix perdix is a UK Biodiversity Action Plan species because of a marked decline in abundance caused by agricultural intensification. Recently, the number of raptors present on farmland and the commercial shooting of red‐legged partridges Alectoris rufa have both increased. To inform conservation action, the relative impacts of these two factors on grey partridge populations urgently require quantification.
On our study site areas of low density of grey partridges coincided with areas of high raptor density. However, these areas were managed intensively for shooting and for two areas that suffered local partridge extinction, the 3‐year average percentage of partridges shot exceeded 50%.
Grey partridge mortality to raptors between autumn and spring lay between 9·5% of autumn density (assumes losses to raptors occurred before shooting) and 15% of post‐shooting density (if all losses to raptors were post‐shooting). A deterministic model suggested that this rate of loss would reduce the equilibrium density of spring pairs by 11–26% relative to a situation without raptors. In comparison, shooting losses across the study area amounted to 35–39% of autumn density, more than double the losses to raptor predation, with a predicted reduction of 68–85% in equilibrium density of spring pairs.
Synthesis and applications. Shooting based on large‐scale releases of red‐legged partridges acts in a density‐independent manner and can lead to local grey partridge extinction. Removing the grey partridge from the UK quarry list would be counterproductive, as most action to boost wild grey partridge densities is carried out by enthusiasts with shooting as the incentive. However, it is imperative that managers of intensive shoots based on gamebird release adopt measures to reduce shooting pressure on wild grey partridges at low density. These include training shooters to distinguish between grey and red‐legged partridges and implementing a warning system (whistle) to alert the gun line when birds of the non‐target species are approaching. Such voluntary measures are effective in addressing overshooting, which has greater implications for grey partridge conservation than raptor predation.
Top predators: hot or not? A call for systematic assessment of biodiversity surrogates
Authors: Cabeza Mar , Arponen Anni , Van Teeffelen Astrid 
Published: July 2007

Summary

Sergio et al. (2006) argue that top predators are justified conservation surrogates based on a case study where raptor presence is associated with high species richness of birds, butterflies and trees.
We question the methodology as well as the applicability of their results, and clarify differences between surrogates for biodiversity hotspots and surrogates for complementarity. We show that the results from Sergio et al. related to richness hotspots are not fully reliable and that the ability of top predators to identify complementary areas is not demonstrated. Given that complementarity‐based surrogate studies have produced mixed results for a variety of reasons, we clarify some methodological misunderstandings while encouraging further testing of functional groups as biodiversity surrogates.
Synthesis and applications. We call for caution in making generalizations, and emphasize that case studies on the use of surrogates should be conducted in a systematic manner. This will facilitate robust assessment across studies regarding the usefulness of particular species groups as biodiversity surrogates.
Molecular dating of the ‘Gondwanan’ plant family Proteaceae is only partially congruent with the timing of the break‐up of Gondwana
Authors: Barker Nigel P. , Weston Peter H. , Rutschmann Frank , Sauquet Hervé 
Published: July 2007

AbstractAim The flowering plant family Proteaceae is putatively of Gondwanan age, with modern and fossil lineages found on all southern continents. Here we test whether the present distribution of Proteaceae can be explained by vicariance caused by the break‐up of Gondwana.Location Africa, especially southern Africa, Australia, New Zealand, South America, New Caledonia, New Guinea, Southeast Asia, Sulawesi, Tasmania.Methods We obtained chloroplast DNA sequence data from therbcL gene, therbcL‐atpB spacer, and theatpB gene from leaf samples of forty‐five genera collected from the field and from living collections. We analysed these data using Bayesian phylogenetic and molecular dating methods, with five carefully selected fossil calibration points to obtain age estimates for the nodes within the family.Results Four of eight trans‐continental disjunctions of sister groups within our sample of the Proteaceae post‐date the break‐up of Gondwana. These involve independent lineages, two with an Africa‐Australia disjunction, one with an Africa–South America disjunction, and one with a New Zealand–Australasia disjunction. The date of the radiation of the bird‐pollinated Embothriinae corresponds approximately to the hypothesized date of origin of nectar‐feeding birds in Australia.Main conclusions The findings suggest that disjunct distributions in Proteaceae result from both Gondwanan vicariance and transoceanic dispersal. Our results imply that ancestors of some taxa dispersed across oceans rather than rafting with Gondwanan fragments as previously thought. This finding agrees with other studies of Gondwanan plants in dating the divergence of Australian, New Zealand and New Caledonian taxa in the Eocene, consistent with the existence of a shared, ancestral Eocene flora but contrary to a vicariance scenario based on accepted geological knowledge.
High frequency of multiple paternity in the largest rookery of Mediterranean loggerhead sea turtles
Authors: ZBINDEN JUDITH A. , LARGIADÈR CARLO R. , LEIPPERT FABIO , MARGARITOULIS DIMITRIS , ARLETTAZ RAPHAËL 
Published: July 2007

AbstractMating systems are a central component in the evolution of animal life histories and in conservation genetics. The patterns of male reproductive skew and of paternal shares in batches of offspring, for example, affect genetic effective population size. A prominent characteristic of mating systems of sea turtles seem to be a considerable intra‐ and interspecific variability in the degree of polyandry. Because of the difficulty of observing the mating behaviour of sea turtles directly in the open sea, genetic paternity analysis is particularly useful for gaining insights into this aspect of their reproductive behaviour. We investigated patterns of multiple paternity in clutches of loggerhead sea turtles in the largest Mediterranean rookery using four highly variable microsatellite loci. Furthermore, we tested for a relationship between the number of fathers detected in clutches and body size of females. More than one father was detected in the clutches of 14 out of 15 females, with two clutches revealing the contribution of at least five males. In more than half the cases, the contributions of different fathers to a clutch did not depart from equality. The number of detected fathers significantly increased with increasing female body size. This relationship indicates that males may prefer to mate with large, and therefore productive, females. Our results suggest that polyandry is likely to increase effective population size compared to a population in which females would mate with only one male; male reproductive contributions being equal.
Rudbeck’s Complaint – A 17th‐Century Latin Letter Relating to Basic Immunology
Authors: Ambrose C. T. 
Published: July 2007

AbstractBasic immunology can be said to have its origin in the mid‐17th‐century with the discovery of the peripheral lymphatics. They completed the gross anatomical picture of the lymphatic system, which is the basis for much of the immune response. Their recognition almost simultaneously by two Scandinavian anatomists led to a protracted war of words over priority of discovery, pitting a young Swedish medical student (Olof Rudbeck) against an honored Danish anatomy professor (Thomas Bartholin). In a 752‐word letter in Latin, Rudbeck charged Bartholin with pre‐dating a key observation, thereby giving priority of discovery to the latter. The purpose of this paper is to provide an English translation of this accusatory letter. It is a notable document in basic immunology, for it cites much of the knowledge then current in the field. And by raising the issue of priority, the letter indirectly piqued the interest of the scientific community in the lymphatic system and hastened its study. Examining the system's various functions in health and disease led to this new discipline.
Rice ABERRANT PANICLE ORGANIZATION 1, encoding an F‐box protein, regulates meristem fate
Authors: Ikeda Kyoko , Ito Momoyo , Nagasawa Nobuhiro , Kyozuka Junko , Nagato Yasuo 
Published: July 2007

SummaryInflorescence architecture is one of the most important agronomical traits. Characterization of rice aberrant panicle organization 1 (apo1) mutants revealed that APO1 positively controls spikelet number by suppressing the precocious conversion of inflorescence meristems to spikelet meristems. In addition, APO1 is associated with the regulation of the plastchron, floral organ identity, and floral determinacy. Phenotypic analyses of apo1 and floral homeotic double mutants demonstrate that APO1 positively regulates class‐C floral homeotic genes, but not class‐B genes. Molecular studies revealed that APO1 encodes an F‐box protein, an ortholog of Arabidopsis UNUSUAL FLORAL ORGAN (UFO), which is a positive regulator of class‐B genes. Overexpression of APO1 caused an increase in inflorescence branches and spikelets. As the mutant inflorescences and flowers differed considerably between apo1 and ufo, the functions of APO1 and UFO appear to have diverged during evolution.
Conservation and divergence of APETALA1/FRUITFULL‐like gene function in grasses: evidence from gene expression analyses
Authors: Preston Jill C. , Kellogg Elizabeth A. 
Published: July 2007

SummaryDuplicated APETALA1/FRUITFULL (AP1/FUL) genes show distinct but overlapping patterns of expression within rice (Oryza sativa) and within ryegrass (Lolium temulentum), suggesting discrete functional roles in the transition to flowering, specification of spikelet meristem identity, and specification of floral organ identity. In this study, we analyzed the expression of the AP1/FUL paralogues FUL1 and FUL2 across phylogenetically disparate grasses to test hypotheses of gene function. In combination with other studies, our data support similar roles for both genes in spikelet meristem identity, a general role for FUL1 in floral organ identity, and a more specific role for FUL2 in outer floral whorl identity. In contrast to Arabidopsis AP1/FUL genes, expression of FUL1 and FUL2 is consistent with an early role in the transition to flowering. In general, FUL1 has a wider expression pattern in all spikelet organs than FUL2, but both genes are expressed in all spikelet organs in some cereals. FUL1 and FUL2 appear to have multiple redundant functions in early inflorescence development. We hypothesize that sub‐functionalization of FUL2 and interaction of FUL2 with LHS1 could specify lemma and palea identity in the grass floret.
A multicolored set of in vivo organelle markers for co‐localization studies in Arabidopsis and other plants
Authors: Nelson Brook K. , Cai Xue , Nebenführ Andreas 
Published: July 2007

SummaryGenome sequencing has resulted in the identification of a large number of uncharacterized genes with unknown functions. It is widely recognized that determination of the intracellular localization of the encoded proteins may aid in identifying their functions. To facilitate these localization experiments, we have generated a series of fluorescent organelle markers based on well‐established targeting sequences that can be used for co‐localization studies. In particular, this organelle marker set contains indicators for the endoplasmic reticulum, the Golgi apparatus, the tonoplast, peroxisomes, mitochondria, plastids and the plasma membrane. All markers were generated with four different fluorescent proteins (FP) (green, cyan, yellow or red FPs) in two different binary plasmids for kanamycin or glufosinate selection, respectively, to allow for flexible combinations. The labeled organelles displayed characteristic morphologies consistent with previous descriptions that could be used for their positive identification. Determination of the intracellular distribution of three previously uncharacterized proteins demonstrated the usefulness of the markers in testing predicted subcellular localizations. This organelle marker set should be a valuable resource for the plant community for such co‐localization studies. In addition, the Arabidopsis organelle marker lines can also be employed in plant cell biology teaching labs to demonstrate the distribution and dynamics of these organelles.
TECHNICAL ADVANCE: Split luciferase complementation assay to study protein–protein interactions in Arabidopsis protoplasts
Authors: Fujikawa Yukichi , Kato Naohiro 
Published: July 2007

SummaryWe developed a split luciferase complementation assay to study protein–protein interactions in Arabidopsis protoplasts. In this assay, the N‐ and C‐terminal fragments of Renilla reniforms luciferase are translationally fused to bait and prey proteins, respectively. When the proteins interact, split luciferase becomes activated and emits luminescence that can be measured by a microplate luminometer. Split luciferase activity was measured by first transforming protoplasts with a DNA vector in a 96‐well plate. DNA vector expressing both bait and prey genes was constructed through two independent in vitro DNA recombinant reactions, Gateway and Cre‐loxP. As proof of concept, we detected the protein–protein interactions between the nuclear histones 2A and 2B, as well as between membrane proteins SYP (syntaxin of plant) 51 and SYP61, in Arabidopsis protoplasts.
Differential gene expression in Arabidopsis wild‐type and mutant anthers: insights into anther cell differentiation and regulatory networks
Authors: Wijeratne Asela J. , Zhang Wei , Sun Yujin , Liu Wenlei , Albert Reka , Zheng Zhengui , Oppenheimer David G. , Zhao Dazhong , Ma Hong 
Published: July 2007

SummaryIn flowering plants, the anther contains highly specialized reproductive and somatic cells that are required for male fertility. Genetic studies have uncovered several genes that are important for anther development. However, little information is available regarding most genes active during anther development, including possible relationships between these genes and genetically defined regulators. In Arabidopsis, two previously isolated male‐sterile mutants display dramatically altered anther cell differentiation patterns. The sporocyteless (spl)/nozzle (nzz) mutant is defective in the differentiation of primary sporogenous cells into microsporocytes, and does not properly form the anther wall. The excess microsporocytes1 (ems1)/extrasporogenous cells (exs) mutants produce excess microsporocytes at the expense of the tapetum. To gain additional insights into microsporocyte and tapetum differentiation and to uncover potential genetic interactions, expression profiles were compared between wild‐type anthers (stage 4–6) and those of the spl or ems1 mutants. A total of 1954 genes were found to be differentially expressed in the ems1 and/or spl anthers, and these were grouped into 14 co‐expression clusters. The presence of genes with known and predicted functions in specific clusters suggests potential functions for other genes in the same cluster. To obtain clues about possible co‐regulation within co‐expression clusters, we searched for shared cis‐regulatory motifs in putative promoter regions. Our analyses were combined with data from previous studies to develop a model of the anther gene regulatory network. This model includes hypotheses that can be tested experimentally to gain further understanding of the mechanisms controlling anther development.