bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe Persistent Cerebellar Dysfunction Complicating Cytosine Arabinoside Therapy
Authors: BOESEN PER , FALLINGBORG JAN , SPAUN EVA
Published: August 2010

ABSTRACT A case of persistent cerebellar dysfunction following high‐dose cytosine arabinoside (Ara‐C) treatment of acute myelogeneous leukemia is reported. The symptoms developed after a cumulative dose of 24 g/m2, and 6 months after the start of symptoms, the signs of cerebellar damage were unchanged. The symptoms aggravated during a subsequent low‐dose therapy with Ara‐C, 15 mg twice daily. This supports the presumption that this adverse effect is caused by the cumulative dose rather than by high plasma concentrations.
Are Effects of Antihypertensive Treatment on Lipoproteins Merely “Side‐effects”?
Authors: LITHELL HANS , HAGLUND KJELL , GRANATH FREDRIK , ÖSTMAN JAN
Published: August 2010

ABSTRACT Thirty‐seven patients with a supine systolic blood pressure >160 and/or a diastolic blood pressure >95 mmHg were enrolled in the study and treated for 6 months with prazosin and 6 months with metoprolol (in random order). Neither the systolic nor the diastolic blood pressures differed after the two types of treatment (median difference 0/0 mmHg). The mean and median differences in serum cholesterol, however, were 0.4 and 0.3 mmol/l respectively, which were 9 and 5% of the pretreatment values. The corresponding differences in the atherogenic index (in which cholesterol in high density lipoproteins is integrated) were 10 and 8% of the pretreatment values. This difference in the metabolic response to the two drugs at the same blood pressure level is most probably of importance in the long‐term prevention of ischaemic heart disease, for which high levels of serum cholesterol and atherogenic index are major risk factors.
Transitest®: A Technetium‐99m Labeled Marker for Determination of Gastrointestinal Transit
Authors: MADSEN JAN L.
Published: August 2010

ABSTRACT Transitest® is a formulation of pellets which can be labeled with the radioisotope technetium‐99m. Transitest® has been proposed as a marker for determination of gastrointestinal transit using a gamma camera. The labeling stability was estimated. Isotonic saline, gastric, and intestinal juice were added to labeled pellets from each of three different batches. Later on the activity was measured in the particulate and the liquid phases. One subject ingested a suspension of labeled pellets. Afterwards scintigraphy of the thyroid and the abdominal region was performed. Simultaneously the activity was measured in the collected urine. The labeling was so unstable that Transitest® cannot be recommended as a marker if quantitative results are required.
Decreased Red Cell Filterability in Patients with Acute Myocardial Infarction
Authors: WALDENLIND LENNART , EDLUND BRITT‐LOUISE , HULTING JOHAN , KARNELL JOHAN , LUND FREDRIK , ROSENHAMER GUNNAR
Published: August 2010

ABSTRACT The red cell filterability was decreased in patients with acute myocardial infarction (AMI) when compared with healthy controls, 14.6 (12.2–16.3) units and 16.9 (15.6–17.4) units respectively, P50 (P25‐P75), p<0.001). No significant correlations could be seen within the AMI group between the decrease in filterability and the levels of serum aspartate aminotransferase or serum lactate dehydrogenase. The erythrocyte filterability, however, correlated to the serum concentrations of hepatic enzymes in AMI. The addition of sodium lactate in vitro in physiological concentrations (0.9‐3.6 mM/l final concentration) lowered the erythrocyte filterability markedly to 2.7 (0–9.8) units in a dose‐dependent manner, supporting the hypothesis that the decrease in erythrocyte filterability in AMI might be caused by an increase in the lactate concentration.
Frequency of Different Types of von Willebrand's Disease in the GDR
Authors: LENK HARALD , NILSSON INGA MARIE , HOLMBERG LARS , WEISSBACH GERHARD
Published: August 2010

ABSTRACT The frequency of different types of von Willebrand's disease (vWD) was studied in the southern part of the GDR and during investigations of relatives of already diagnosed patients. Among 111 patients diagnosed, vWD was found to be type I in 85 cases, type II in 13 cases and severe recessive type in 13 cases. The patients with type I belonged to 46 different families. Two families with type II had the IIA variant and another a variant similar to IIC. No patients with type IIB were diagnosed. The incidence of severe recessive vWD was estimated to be lower than in Sweden but higher than in Italy and France.
High Activities of Erythrocyte Glutathione Peroxidase in Patients with the Lesch‐Nyhan Syndrome
Authors: DIDRIK SAUGSTAD OLA , MARKLUND STEFAN L.
Published: August 2010

ABSTRACT Antioxidant levels were determined in five patients with the Lesch‐Nyhan syndrome. The erythrocyte glutathione peroxidase activity was in average 1.8 times higher in Lesch‐Nyhan patients than in controls (1.68f0.36 versus 0.92k0.17 pkat/g hemoglobin, p<0.001). Plasma CuZn‐superoxide dismutase activity was two times higher (p<0.001) and Mn‐superoxide dismutase activity was 1.5 times higher (p<0.05) than in controls, whilst erythrocyte CuZnsuperoxide dismutase, plasma extracehlar‐superoxide dismutase and lymphocyte superoxide dismutase did not differ between Lesch‐Nyhan patients and healthy controls. These data might indicate that Lesch‐Nyhan patients are exposed to a higher oxidative load than healthy control persons.
Muscle Function and Morphology in Myotonic Dystrophy
Authors: GRIMBY GUNNAR , HEDBERG MARITA , HENRIKSSON KARL‐GÖSTA , JOHANSSON GÖRAN , WIGERSTAD‐LOSSING INGRID , SELLDÉN ULLA , ÖRNDAHL GUSTAV
Published: August 2010

Abstract. Patients with myotonic dystrophy classified clinically into function groups were studied. Muscle strength for knee extension and flexion was, with few exceptions, moderately or markedly reduced with successively more severe clinical disability. The reduction in maximal walking speed showed a similar tendency. There was a large percentage of both type I and in relation to normal findings of type II C fibers in biopsies from most patients. The fiber area varied greatly even in the patients in the best function groups, some of whom had large type II fibers. The most common histopathological changes, found in all function groups, were fiber atrophy with small angular fibers, internal nuclei, splitting, fibrosis and moth‐eaten fibers. A high percentage of type I fibers can already be seen in patients with practically no other morphological changes and without significant functional deterioration.
Frequency of Hepatic Cysts in Adult Polycystic Kidney Disease
Authors: THOMSEN HENRIK S. , THAYSEN JØRN HESS
Published: August 2010

Abstract. The frequency of hepatic cysts in patients with adult polycystic kidney disease (APKD) is usually considered to average about 33%, but with great, and hitherto largely unexplained, variations between different studies. Sixty‐six consecutive patients with APKD were all subjected to CT scanning of the liver and of the kidneys. In confirmation of one previous study, a clearcut correlation was found between age (=duration of disease) and the frequency of hepatic cysts. It was furthermore found that cysts in the liver, as opposed to cysts in the kidneys, continue to grow and appear de novo even after institution of renal replacement therapy.
Papillary Muscle Rupture as a First Event in Acute Myocardial Infarction
Authors: SØRENSEN HENRIK TOFT , NIELSEN FINN , SØRENSEN JACOB
Published: August 2010

Abstract. Cardiogenic shock caused by papillary muscle rupture in acute myocardial infarction is potentially reversible by surgical treatment. A case of inferior myocardial infarction in a 56‐year‐old previously healthy man is reported, in which the first event was papillary muscle rupture. The patient was in shock and had a mitral insufficiency murmur. The diagnosis was made by echocardiography and ventriculography. A St. Jude valve was implanted, and the patient was discharged in good health. It is suggested that routine echocardiography be carried out on patients with sudden cardiogenic shock, when a mitral murmur is present.
Pneumococcal Vaccination in Splenectomized Patients with Hematological Disorders
Authors: LINDBLAD RAGNAR , KAIJSER BERTIL , MAGNUSSON BENGT , RÖDJER STIG , WESTIN JAN
Published: August 2010

Abstract. Seventy splenectomized patients were vaccinated with Pneumovax®, a pneumococcal polysaccharide vaccine. Twenty‐four of the patients had a malignant and 30 a non‐malignant hematological disorder. The remaining 16 were patients with no known hematological disorder, seven with intra‐abdominal carcinomas and nine with non‐malignant reasons for splenectomy. About 90% of the patients with non‐malignant hematological disorders responded to vaccination with a rise in antibody titres, which was significantly higher than in the other two groups studied. Malignant hematological disorders lowered the response rate to 61–67%. Patients with no known hematological disorder but with intraabdominal carcinomas also responded less frequently, while those in this group with other surgical reasons for splenectomy had a response rate comparable to healthy individuals. No serious side‐effects were reported and we therefore conclude that all splenectomized patients should be vaccinated with a pneumococcal vaccine. However, it must always be born in mind that one third of the patients with malignant disease did not respond to vaccination.
Biochemical Evidence of Disturbed Bone Metabolism and Calcium Homeostasis in Two Types of Autosomal Dominant Osteopetrosis
Authors: BOLLERSLEV JENS , NIELSEN HENNING K. , LARSEN HANS F. , MOSEKILDE LEIF
Published: August 2010

Abstract. Biochemical markers of bone resorption and bone formation were measured in 14 patients with autosomal dominant osteopetrosis, and compared with age‐ and sex‐matched controls. There were eight patients with the radiological type I characterized by diffuse, symmetrical osteosclerosis with pronounced sclerosis of the skull and enlarged thickness of the cranial vault, and six patients with type II characterized by diffuse, symmetrical osteosclerosis, “Rugger‐Jersey spine” and “endobones” (bone within a bone) in the pelvis. Serum levels of alkaline phosphatase and osteocalcin in types I and II did not differ from controls indicating normal bone formation. However, a significantly decreased fasting renal excretion of phosphate and hydroxyproline in both types compared with normal controls, suggests a reduced bone resorption. Serum levels of parathyroid hormone (PTH), albumin‐corrected calcium, phosphate, and acid phosphatase were normal in type I. In type II serum levels of albumin‐corrected calcium and PTH were significantly increased (p<0.05 and p<0.01). The level of acid phosphatase was markedly increased in this type (p<0.01). These findings suggest differences between the two types in calcium homeostasis and bone metabolism, and thus corroborate the evidence that the two radiological types reflect two different disorders of bone resorption.
The Tromsø Heart Study: Coronary Risk Factor Levels in Treated and Untreated Hypertensives
Authors: LØCHEN MAJA‐LISA
Published: August 2010

Abstract. Coronary risk factors are described in 288 medically treated hypertensives, 1293 untreated hypertensives and 15029 normotensives. Cholesterol in untreated men and women was 0.37 mmol/l and 0.35 mmol/l higher than in normotensives (p<0.001). Non‐significant differences were observed between those untreated and treated. Treated men and women had 0.16 mmol/l and 0.14 mmol/l lower HDL cholesterol than untreated (p<0.01). Between untreated and normotensives non‐significant differences were found. Triglycerides were 0.27 mmol/l and 0.22 mmol/l higher in treated than in untreated men and women (p<0.01). Normotensive men and women had 0.33 mmol/l and 0.10 mmol/l lower triglycerides than untreated (p<0.01). The results suggest that the increased cholesterol in hypertensives was present originally, while the decreased HDL cholesterol and elevated triglycerides probably were evoked by drugs. The importance of consideration of the whole constellation of risk factors in order to reduce the mortality from coronary heart disease by antihypertensive drug treatment is emphasized.
Hyperuricaemia and Risk of Cardiovascular Disease and Overall Death
Authors: BENGTSSON CALLE , LAPIDUS LEIF , STENDAHL CHARLOTTE , WALDENSTRÖM JOHAN
Published: August 2010

Abstract.Serum uric concentration was determined in a series of 1462 women, aged 38–60 when first examined in 1968–69, as the first phase of a longitudinal population study in Gothenburg, Sweden. Serum uric acid concentration was positively correlated to the 12‐year overall mortality in univariate analysis. No relationship was observed between initial serum uric acid values and incidence of myocardial infarction, angina pectoris, ECG changes indicating ischaemic heart disease or stroke. The association between serum uric acid concentration and mortality was independent of age, body mass index, systolic blood pressure, adipose tissue distribution, smoking habits, serum cholesterol concentration, serum triglyceride concentration, serum creatinine concentration, serum calcium concentration, use of diuretics, and haematological disease. The increased mortality could not be explained by any increase in malignant neoplastic disease.
Activity of Hypothalamic Dopaminergic Neurones During the Day of Oestrus: Involvement in Prolactin Secretion
Authors: Leite C. M. , Ribeiro A. B. , Szawka R. E. , Anselmo‐Franci J. A.
Published: August 2010

A secretory surge of prolactin occurs on the afternoon of oestrus in cycling rats. Pituitary prolactin is inhibited by dopamine. We evaluated the activity of the neuroendocrine dopaminergic neurones during oestrus and dioestrus, as determined by dopaminergic activity in the median eminence and neurointermediate lobe of the pituitary, as well as Fos‐related antigen expression in tyrosine hydroxylase (TH)‐immunoreactive (ir) neurones of the arcuate nucleus (ARC) and periventricular nucleus (Pe). During oestrus, the 4‐dihydroxyphenylacetic acid/dopamine ratio in the median eminence decreased at 16.00 h, coinciding with the increase in plasma prolactin levels. Similarly, the expression of Fos‐related antigen in TH‐ir neurones of Pe and rostral‐, dorsomedial‐ and caudal‐ARC also decreased at 16.00 h. On dioestrus, 4‐dihydroxyphenylacetic acid/dopamine ratio in the median eminence and Fos‐related antigen expression in TH‐ir neurones of Pe and rostral‐ARC decreased at 18.00 h, whereas prolactin levels were unaltered. No variation in dopaminergic activity was found in the neurointermediate lobe of the pituitary on either oestrus or dioestrus. The number of TH‐ir neurones in the ARC and parameters of dopaminergic activity were found to be generally lower on oestrus compared to dioestrus. The transitory decrease in the activity of neuroendocrine dopaminergic neurones temporally associated with the prolactin surge on the afternoon of oestrus suggests a role for dopamine in the generation of the oestrous prolactin surge.
Taking the chaos out of genetic patchiness: seascape genetics reveals ecological and oceanographic drivers of genetic patterns in three temperate reef species
Authors: SELKOE KIMBERLY A. , WATSON JAMES R. , WHITE CROW , HORIN TAL BEN , IACCHEI MATTHEW , MITARAI SATOSHI , SIEGEL DAVID A. , GAINES STEVEN D. , TOONEN ROBERT J.
Published: August 2010

Marine species frequently show weak and/or complex genetic structuring that is commonly dismissed as ‘chaotic’ genetic patchiness and ecologically uninformative. Here, using three datasets that individually feature weak chaotic patchiness, we demonstrate that combining inferences across species and incorporating environmental data can greatly improve the predictive value of marine population genetics studies on small spatial scales. Significant correlations in genetic patterns of microsatellite markers among three species, kelp bass Paralabrax clathratus, Kellet’s whelk Kelletia kelletii and California spiny lobster Panulirus interruptus, in the Southern California Bight suggest that slight differences in diversity and pairwise differentiation across sampling sites are not simply noise or chaotic patchiness, but are ecologically meaningful. To test whether interspecies correlations potentially result from shared environmental drivers of genetic patterns, we assembled data on kelp bed size, sea surface temperature and estimates of site‐to‐site migration probability derived from a high resolution multi‐year ocean circulation model. These data served as predictor variables in linear models of genetic diversity and linear mixed models of genetic differentiation that were assessed with information–theoretic model selection. Kelp was the most informative predictor of genetics for all three species, but ocean circulation also played a minor role for kelp bass. The shared patterns suggest a single spatial marine management strategy may effectively protect genetic diversity of multiple species. This study demonstrates the power of environmental and ecological data to shed light on weak genetic patterns and highlights the need for future focus on a mechanistic understanding of the links between oceanography, ecology and genetic structure.
Seascape genetics along a steep cline: using genetic patterns to test predictions of marine larval dispersal
Authors: GALINDO HEATHER M. , PFEIFFER‐HERBERT ANNA S. , McMANUS MARGARET A. , CHAO YI , CHAI FEI , PALUMBI STEPHEN R.
Published: August 2010

Coupled biological and physical oceanographic models are powerful tools for studying connectivity among marine populations because they simulate the movement of larvae based on ocean currents and larval characteristics. However, while the models themselves have been parameterized and verified with physical empirical data, the simulated patterns of connectivity have rarely been compared to field observations. We demonstrate a framework for testing biological‐physical oceanographic models by using them to generate simulated spatial genetic patterns through a simple population genetic model, and then testing these predictions with empirical genetic data. Both agreement and mismatches between predicted and observed genetic patterns can provide insights into mechanisms influencing larval connectivity in the coastal ocean. We use a high‐resolution ROMS‐CoSINE biological‐physical model for Monterey Bay, California specifically modified to simulate dispersal of the acorn barnacle, Balanus glandula. Predicted spatial genetic patterns generated from both seasonal and annual connectivity matrices did not match an observed genetic cline in this species at either a mitochondrial or nuclear gene. However, information from this mismatch generated hypotheses testable with our modelling framework that including natural selection, larval input from a southern direction and/or increased nearshore larval retention might provide a better fit between predicted and observed patterns. Indeed, moderate selection and a range of combined larval retention and southern input values dramatically improve the fit between simulated and observed spatial genetic patterns. Our results suggest that integrating population genetic models with coupled biological‐physical oceanographic models can provide new insights and a new means of verifying model predictions.
Landscape genetics of high mountain frog metapopulations
Authors: MURPHY M. A. , DEZZANI R. , PILLIOD D. S. , STORFER A.
Published: August 2010

Explaining functional connectivity among occupied habitats is crucial for understanding metapopulation dynamics and species ecology. Landscape genetics has primarily focused on elucidating how ecological features between observations influence gene flow. Functional connectivity, however, may be the result of both these between‐site (landscape resistance) landscape characteristics and at‐site (patch quality) landscape processes that can be captured using network based models. We test hypotheses of functional connectivity that include both between‐site and at‐site landscape processes in metapopulations of Columbia spotted frogs (Rana luteiventris) by employing a novel justification of gravity models for landscape genetics (eight microsatellite loci, 37 sites, n = 441). Primarily used in transportation and economic geography, gravity models are a unique approach as flow (e.g. gene flow) is explained as a function of three basic components: distance between sites, production/attraction (e.g. at‐site landscape process) and resistance (e.g. between‐site landscape process). The study system contains a network of nutrient poor high mountain lakes where we hypothesized a short growing season and complex topography between sites limit R. luteiventris gene flow. In addition, we hypothesized production of offspring is limited by breeding site characteristics such as the introduction of predatory fish and inherent site productivity. We found that R. luteiventris connectivity was negatively correlated with distance between sites, presence of predatory fish (at‐site) and topographic complexity (between‐site). Conversely, site productivity (as measured by heat load index, at‐site) and growing season (as measured by frost‐free period between‐sites) were positively correlated with gene flow. The negative effect of predation and positive effect of site productivity, in concert with bottleneck tests, support the presence of source–sink dynamics. In conclusion, gravity models provide a powerful new modelling approach for examining a wide range of both basic and applied questions in landscape genetics.
Genetic diversity and differentiation at MHC genes in island populations of tuatara (Sphenodon spp.)
Authors: MILLER HILARY C. , ALLENDORF FRED , DAUGHERTY CHARLES H.
Published: August 2010

Neutral genetic markers are commonly used to understand the effects of fragmentation and population bottlenecks on genetic variation in threatened species. Although neutral markers are useful for inferring population history, the analysis of functional genes is required to determine the significance of any observed geographical differences in variation. The genes of the major histocompatibility complex (MHC) are well‐known examples of genes of adaptive significance and are particularly relevant to conservation because of their role in pathogen resistance. In this study, we survey diversity at MHC class I loci across a range of tuatara populations. We compare the levels of MHC variation with that observed at neutral microsatellite markers to determine the relative roles of balancing selection, diversifying selection and genetic drift in shaping patterns of MHC variation in isolated populations. In general, levels of MHC variation within tuatara populations are concordant with microsatellite variation. Tuatara populations are highly differentiated at MHC genes, particularly between the northern and Cook Strait regions, and a trend towards diversifying selection across populations was observed. However, overall our results indicate that population bottlenecks and isolation have a larger influence on patterns of MHC variation in tuatara populations than selection.
Genes essential for morphological development and antibiotic production in Streptomyces coelicolor are targets of BldD during vegetative growth
Authors: Den Hengst Chris D. , Tran Ngat T. , Bibb Maureen J. , Chandra Govind , Leskiw Brenda K. , Buttner Mark J.
Published: August 2010

BldD is a transcriptional regulator essential for morphological development and antibiotic production in Streptomyces coelicolor. Here we identify the BldD regulon by means of chromatin immunoprecipitation‐microarray analysis (ChIP‐chip). The BldD regulon encompasses ∼167 transcriptional units, of which more than 20 are known to play important roles in development (e.g. bldA, bldC, bldH/adpA, bldM, bldN, ssgA, ssgB, ftsZ, whiB, whiG, smeA‐ssfA) and/or secondary metabolism (e.g. nsdA, cvn9, bldA, bldC, leuA). Strikingly, 42 BldD target genes (∼25% of the regulon) encode regulatory proteins, stressing the central, pleiotropic role of BldD. Almost all BldD binding sites identified by ChIP‐chip are present in the promoters of the target genes. An exception is the tRNA gene bldA, where BldD binds within the region encoding the primary transcript, immediately downstream of the position corresponding to the processed, mature 3′ end of the tRNA. Through gene overexpression, we identified a novel BldD target gene (cdgA) that influences differentiation and antibiotic production. cdgA encodes a GGDEF domain protein, implicating c‐di‐GMP in the regulation of Streptomyces development. Sequence analysis of the upstream regions of the complete regulon identified a 15 bp inverted repeat that functions as a high‐affinity binding site for BldD, as was shown by electrophoretic mobility shift assays and DNase I footprinting analysis. High‐scoring copies of the BldD binding site were found at relevant positions in the genomes of other bacteria containing a BldD homologue, suggesting the role of BldD is conserved in sporulating actinomycetes.
A path from predation to mutualism
Authors: Danchin Antoine
Published: August 2010

Luminescent bacteria and nematodes associate in a strategy where the bacteria act as virulent pathogens of insects, used as their food supply, while the nematodes graze on them. Upon reaching high density, the bacteria produce light and metabolites that turn the nematodes into hosts permitting them to be carried over to further nematode preys. In this issue of Molecular Microbiology, Lango and Clarke show that the corresponding shift in lifestyle is triggered by a metabolic switch closely linked to the tricarboxylic acid cycle, but apparently not by the well‐known acetate switch that monitors entry of bacteria into the stationary phase of growth.
A backtrack‐inducing sequence is an essential component of Escherichia coli	σ70‐dependent promoter‐proximal pausing
Authors: Perdue Sarah A. , Roberts Jeffrey W.
Published: August 2010

RNA polymerase of both bacteria and eukaryotes can stall or pause within tens of base pairs of its initiation site at the promoter, a state that may reflect important regulatory events in early transcription. In the bacterial model system, the σ70 initiation factor stabilizes such pauses by binding a downstream repeat of a promoter segment, especially the ‘−10’ promoter element. We first show here that the ‘−35’ promoter element also can stabilize promoter‐proximal pausing, through interaction with σ70 region 4. We further show that an essential element of either type of pause is a sequence just upstream of the site of pausing that stabilizes RNA polymerase backtracking. Although the pause is not intrinsically backtracked, we suggest that the same sequence element is required both to stabilize the paused state and to potentiate backtracking.
A rainbow coalition of lipid transcriptional regulators
Authors: Zhang Yong‐Mei , Rock Charles O.
Published: August 2010

Lipids are essential structural constituents of bacterial cell membranes and walls, and their biosynthetic pathways are stringently regulated at both biochemical and genetic levels. The recent surge of new information about transcriptional regulation of bacterial lipid metabolism is highlighted by two studies in this issue of Molecular Microbiology by Hugo Gramajo's research group, who add two transcription factors to the diverse repertoire of lipid biosynthesis regulators. FasR is a Streptomyces coelicolor transcriptional activator of genes in fatty acid synthesis, which supplies substrates for membrane phospholipid and triglyceride storage droplets. MabR is a regulator in Mycobacterium tuberculosis that functions as a repressor of essential genes in the cell wall mycolic acid biosynthetic pathway. MabR also affects the expression of fas, which encodes the multifunctional fatty acid synthase that supports phospholipid and triglyceride synthesis. Despite belonging to the same protein family, the distinct ligand binding domains of FasR and MabR suggest different ligands may regulate their DNA binding. The characterization of FasR/MabR exemplifies the structural and functional diversity of the rainbow coalition of lipid transcriptional regulators that reflects the diverse life styles of bacteria.
The FACT subunit TbSpt16 is involved in cell cycle specific control of VSG expression sites in Trypanosoma brucei
Authors: Denninger Viola , Fullbrook Alexander , Bessat Mohamed , Ersfeld Klaus , Rudenko Gloria
Published: August 2010

The African trypanosome Trypanosoma brucei monoallelically expresses one of more than 1000 Variant Surface Glycoprotein (VSG) genes. The active VSG is transcribed from one of about 15 telomeric VSG expression sites (ESs). It is unclear how monoallelic expression of VSG is controlled, and how inactive VSG ESs are silenced. Here, we show that blocking synthesis of the T. brucei FACT subunit TbSpt16 triggers a G2/early M phase cell cycle arrest in both bloodstream and insect form T. brucei. Segregation of T. brucei minichromosomes in these stalled cells is impaired, implicating FACT in maintenance of centromeres. Strikingly, knock‐down of TbSpt16 results in 20‐ to 23‐fold derepression of silent VSG ES promoters in bloodstream form T. brucei, with derepression specific to the G2/M cell cycle stage. In insect form T. brucei TbSpt16 knock‐down results in 16‐ to 25‐fold VSG ES derepression. Using chromatin immunoprecipitation (ChIP), TbSpt16 was found to be particularly enriched at the promoter region of silent but not active VSG ESs in bloodstream form T. brucei. The chromatin remodeler FACT is therefore implicated in maintenance of repressed chromatin present at silent VSG ES promoters, but is also essential for chromosome segregation presumably through maintenance of functional centromeres.
Male territoriality and ‘sex confusion’ in recently adapted lizards at White Sands
Authors: ROBERTSON J. M. , ROSENBLUM E. B.
Published: August 2010

The evolution of intersexual interactions, like mate choice, during ecological speciation has received widespread attention. However, changes in intrasexual interactions, like male territoriality, during ecological divergence are largely unexamined. We conducted field experiments with adaptively diverged populations of the eastern fence lizard (Sceloporus undulatus) to determine whether territorial males behaved differently towards ecologically similar vs. dissimilar intruders. We performed trials with light‐coloured males from White Sands, New Mexico and dark‐coloured males from the surrounding desert. We found that intruders from White Sands elicited more aggression than intruders from dark‐soil habitat. We also documented a case of ‘sex confusion’ where white‐sand males courted dark‐soil intruders. We found population differences in signalling patch size that can explain both aggression bias and sex misidentification. We argue that direct selection (for population recognition or optimal signal transmission) and indirect selection (by‐products of ecological adaptation) should influence both intersexual and intrasexual interactions during ecological speciation.
Fire, storm, flood and drought: The vegetation ecology of Howards Peninsula, Northern Territory, Australia
Authors: WILSON B. A. , BOWMAN D. M. J. S.
Published: August 2010

Twenty different communities, characteristic of the coastal vegetation of the northern portion of the Northern Territory, were recognized by photo‐interpretation and ground truthing a 20 × 20 km area near Darwin. Data collected from 161 quadrats placed throughout the study area showed a strong relationship between subjective and objective measures of vegetation structure. Photopattern is best explained by a combination of structural, lifeform and floristic data. The mangrove, grassland, forest and woodland communities form a complex spatial pattern. Variations in moisture regime, through the interaction of topography and soils with temporal fluctuations of salt and/or fresh water supply, appear to best explain vegetation distribution. Three anomalously open eucalypt communities are interpreted as being the consequence of a severe tropical cyclonic storm which destroyed much of Darwin in 1974. These communities are frequently burnt by the nearby urban population and possess layers of sapling size eucalypts, although the height and density of the regrowth appears to vary with site quality. It is argued that fire is a characteristic of the seasonal climate, and that the fire pattern largely reflects the vegetation pattern. Occasional severe tropical storms also affect vegetation types differently. The greatest amount of windthrow occurs in moist monsoon forests while the eucalypts on well drained soils are more windfirm, but remain obviously damaged for over 10 years.
Mulga bird communities. I. Species composition and predictability across Australia
Authors: CODY MARTIN L.
Published: August 2010

Abstract
Data are presented from bird censuses at 20 mulga (Acacia aneura) sites across Australia. Null (binomial) models show that community composition is far more consistent among censuses than is expected by a random drawing from all candidate species. By denning and using the designations ‘core species’, ‘peripheral species’, and ‘casual species’, it was shown that 32% of the total 81 bird species censused constituted core species and core niches that account for nearly 75% of the bird density in mulga bird communities countrywide.

A minor proportion of the variation in the mulga censuses was attributable to geographic variation in vegetation structure, related to the β‐component of diversity. Some mulga niches have regional replacements that contribute to a species turnover among sites and to the γ‐diversity of the species set; other species of sporadic occurrence are attributable to the geographic position of the mulga site in terms of adjacent habitats (mostly eucalypt woodland and mixed acacia scrub), a ‘spillover’ effect.

Regional variations in the composition of some specific guilds, namely ‘crows’, ‘wrens’, ‘butcherbirds’, foliage insectivores, ground‐foraging insectivores, perch‐and‐pounce foragers and mid‐sized, ground‐foraging omnivores, are analysed in some detail to illustrate factors that contribute to a large species total in mulga, despite the predominance of core species.
Long‐term changes in the vegetation after the cessation of livestock grazing in Eucalyptus marginata (jarrah) woodland remnants
Authors: Pettit N. E. , Froend R. H.
Published: August 2010

This paper documents changes in the floristic composition of Eucalyptus marginata Donn (jarrah) woodlands over 7 years of recovery from continual, intensive livestock grazing. In remnants of native woodland left after agricultural clearing, which have been subjected to livestock grazing, comparisons were made between the floristics of fenced exclosure plots and open plots that continued to be grazed. The vegetation in nearby remnants, which had not been subjected to livestock grazing, was also surveyed. An initial increase in annual exotic pasture species after grazing relief was only temporary and highly influenced by fluctuations in annual climatic patterns, particularly rainfall distribution and abundance. Subsequent years saw a decrease in exotic annuals in exclosure plots and an increase in native perennials, in a trend towards becoming more floristically similar to the ungrazed sites. Germination of overstorey species was observed in the exclosure plots, however, development of seedlings and saplings was sparse. Results indicate that for jarrah woodland in southwestern Australia, natural regeneration is possible after the removal of livestock, with the return (within 6 years) of native species richness to levels similar to those found in ungrazed vegetation. Re‐establishment of cover, however, appears to take longer. The floristic dynamics are described in terms of a nonequilibrium model. Two vegetation states exist, degraded remnants with an understorey dominated by annual species, and ungrazed vegetation with an understorey dominated by perennial shrubs and herbs. The former state is maintained by continual heavy grazing by livestock. Upon relief from grazing, the vegetation undergoes a transition towards floristic similarity to ungrazed vegetation. After 6 years, vegetation change in the exclosure plots appears to be continuing and therefore it is still in transition.
Estimates of forest floor litter frog communities: A comparison of two methods
Authors: Rocha Carlos Frederico D. , Sluys Monique Van , Alves Maria Alice S. , Bergallo Helena G. , Vrcibradic Davor
Published: August 2010

Estimates of forest leaf litter frog density, mass, richness and diversity given by the widely used 8 m × 8 m large plot method (LPM) were compared with estimates obtained by a newly proposed method (small 2 m × 1 m plots with leaf removal; SPLR). The study site was an undisturbed area of the Atlantic Rainforest of Ilha Grande, an island located in the south of Rio de Janeiro State, Brazil. Twenty‐four LPM (totalling 1536 m2 of forest floor) and 90 SPLR (totalling 180 m2 of forest floor) were performed. The estimates obtained by the two methods differed markedly, indicating that even using a much smaller sampling area (11.7% of that of LPM), SPLR gave frog density estimates six times higher, and frog mass estimates approximately 2.5 times higher than estimates provided by LPM. The species richness and diversity obtained by the two methods were similar, despite the fact that the total area sampled with SPLR was much smaller. These data suggest that LPM may underestimate the abundance and biomass of leaf litter frogs in a given area.
Understanding the toad code: Behavioural responses of cane toad (Chaunus marinus) larvae and metamorphs to chemical cues
Authors: HAGMAN MATTIAS , SHINE RICHARD
Published: August 2010

Abstract  Larvae of many anuran taxa display strong behavioural responses to chemical cues, including alarm signals from injured conspecific tadpoles. We exposed tadpoles and metamorphs from an Australian population of the invasive cane toad (Chaunus[Bufo] marinus) to a range of chemical stimuli and quantified their responses both in the laboratory and in the field. Filtered fluids containing scent cues from crushed conspecifics elicited strong avoidance from tadpoles, whereas other cues (e.g. scent of food, of native‐range fish or urodele predators, and thermal stimuli) did not. Apparent aggregation of tadpoles in response to scent cues proved to be an artifact of tank design, and was an indirect consequence of avoidance of those cues. Field trials confirmed that free‐ranging toad tadpoles and metamorphs avoided chemical cues from crushed conspecifics, suggesting that the chemicals inducing this response might provide an opportunity to develop targeted control methods for this invasive species.
Effect of additional food and water on house mice in a semi‐arid agricultural environment in Australia
Authors: BROWN PETER R. , ARTHUR ANTHONY D. , JONES DEAN A. , DAVIES MICAH J.
Published: August 2010

Abstract  We tested the hypothesis that providing high‐quality food and water would increase reproduction, survival and population size in house mice living in a semi‐arid cropping environment in the mallee region of western Victoria, Australia, where outbreaks of house mice (Mus domesticus) occur irregularly. We employed a factorial design and applied treatments along internal fencelines (16 sites), adjacent to cropping areas, from November 2003 to July 2004. Population abundance was low during the experiment (0–26 mice per site), and the summer rainfall was below average. We confirmed that mice used the supplementary food and water through a reduction in weight of food containers over time and for water through the presence of Rhodamine B in blood samples and positive bands in whiskers. Abundant food was also available through grain spilt on the ground after harvest of the wheat and barley crops. There was some evidence of increased breeding on sites where water was added, but no effect of food or food and water in combination. Sites where free water was available had marginally higher populations over summer (∼2 more mice on average; P = 0.07). This difference was well below any biologically meaningful effect. Mice were 0.9 g heavier on sites where water was added (P = 0.04), and were in better condition (P = 0.03). The addition of high‐quality food did not affect mouse population dynamics, and the addition of water resulted in only marginal responses for some demographic characteristics. We conclude that other factors appear to be important for limiting mouse population growth in summer and autumn.
Alfred Russel Wallace as ancestor figure: Reflections on anthropological lineage after the Darwin bicentennial (Respond to this article at http://www.therai.org.uk/at/debate)
Authors: Lowrey Kathleen Bolling
Published: August 2010

The article argues that anthropology might look to Alfred Russel Wallace as an ancestor figure for three reasons. First, it is under‐recognized that he was an accomplished and sympathetic ethnographic fieldworker. Second, evidence is emerging that his intuitions were surer than were Darwin's as to evolutionary mechanisms. Third, he was willing to appear as a “crank” on questions of ontology. These last two issues animate anthropology as we presently know it, and Wallace's stances on both may serve as a salutary inspirations.
The tentacles of Ichthyophis (Amphibia: Caecilia) with special reference to the skin
Authors: Fox Harold
Published: August 2010

The skin of the paired tentacles of Ichthyophis consists of a cornified epidermis of 5–7 layers of epidermal cells, and a glandular dermis of ducted mucous glands, in association with collagen, blood vessels, fibroblasts, granulocytes, sparse melanophores and characteristic laminophores of unknown function. The epidermis is highly innervated at all levels below the stratum corneum by naked neurites, which originate as branches from large unmyelinated nerve bundles (and associated Schwann cells), located sub‐epidermally, and which are part of the trigeminal cranial nerve. Myelinated nerves are also present below the epidermis, spatially associated with capillaries and glands. The study of the ultrastructure of the tentacle supports a concept of a sensory function, possibly tactile, though until further information from experimentation is available, any ideas on the specific nature of these sensory activities must remain speculative.
Interannual variability in fruit abundance and the reproductive seasonality in Sumatran Long‐tailed macaques (Macaca fascicularis)
Authors: Schaik Carel P. van , Noordwijk Maria A. van
Published: August 2010

In an environment with a seasonal food supply, most primate species show birth peaks which precede the peak food period by some two to five months. Sumatran Long‐tailed macaques (Macaca fascicularis), however, showed birth peaks during or after the fruit peak. Years of high birth rates and early birth peaks alternated with years of low birth rates and late peaks. The timing of births was strongly influenced by a female's condition, which depends on food supply and her previous reproductive history. Pregnant females were more active than other females, whereas females with young infants were less active.

The unusual timing of births is ascribed to the unpredictability of the height of the annual fruit peak. This hypothesis is supported by the reproductive patterns of other South‐east Asian primates and by a model comparing the two types of reproductive timing. Further differences between the two strategies of reproductive timing are predicted.
The vertical distribution of the British intertidal Acari—the non halacarid fauna (Arachnida: Acari)
Authors: Pugh P. J. A. , King P. E.
Published: August 2010

The vertical distribution of the non halacarid littoral Acari on rocky shores was examined. The habitat of these Acari was investigated and compared with that of the Halacaridae. Some physiological factors were investigated to explain this distribution. Three ecologically distinct life styles were recognized among these Acari.
Long‐bone circumference and weight in mammals, birds and dinosaurs
Authors: Anderson J. F. , Hall‐Martin A. , Russell D. A.
Published: August 2010

The mid‐shaft circumferences of the humerus and femur are closely related to body weight in living terrestrial vertebrates. Because these elements are frequently preserved in subfossil and fossil vertebrate skeletal materials, the relationship can be used to estimate body weight in extinct vertebrates. When the allometric equations are applied to the mid‐shaft circumferences of these elements in dinosaurs, the weights calculated for some giant sauropods (Brachiosaurus) are found to be lighter than previous estimates.
An immunological analysis of the phylogenetic relationships between two enigmatic frogs, Myobatrachus and Arenophryne
Authors: Maxson Linda R. , Roberts J. D.
Published: August 2010

The monotypic Australian frog genera Myobatrachus and Arenophryne occur in Western Australia. Myobatrachus has a bizarre appearance with a small, narrow head and extremely short limbs—features which may represent adaptations to its forward burrowing habit and dietary specialization on termites. Because of its unusual morphology, Myobatrachus has been interpreted as a representative of an old lineage dating back to the early Tertiary or late Mesozoic era. Phylogenetic analysis of albumin evolution in these two genera, as well as five additional purportedly related frog genera, demonstrates that Myobatrachus and Arenophryne are one another's closest genetic relatives and these lineages most likely diverged in the Miocene. The genera Metacrinia and Pseudophryne are most closely related to the lineage giving rise to Myobatrachus and Arenophryne, with these two major lineages diverging in the early Miocene.
Morphology and cell population kinetics of primary spermatogonia in the frog (Rana esculenta) (Amphibia: Anura)
Authors: Rastogi R. K. , Meglio M. Di , Matteo L. Di , Minucci S. , Iela L.
Published: August 2010

Two morphologically distinct primary spermatogonial cell types were observed in the frog testis and distinguished on the basis of nuclear characteristics. They have been designated the pale and dark types of primary spermatogonia. On the basis of a kinetic analysis, it is proposed that the pale spermatogonia possess the faculty of self‐renewal as well as that of forming dark spermatogonia; they are thus bipotential stem cells comparable to the undifferentiated type of mammalian spermatogonia. The dark spermatogonia, in contrast, are committed to a single pathway, i.e. to form secondary sperrnatogonia, and can be defined as differentiated or committed elements of the primary spermatogonial population. The number of stem cell spermatogonia and differentiated spermatogonia vary according to the period of the year, as does the rate of turnover of stem cells, with nearly 60–90% of cells temporarily out of the cell cycle at any given time. It is indicated that the spermatogonial population represents a ‘cell renewal system’ in a steady state for appreciably long periods of time, however, changing with season in as far as the magnitude of yield of spermatogonial cells is concerned. This implies that an equality should exist between the rate at which stem cells enter cell‐cycling and the rate at which daughter cells change their morphological identity.
Condition and related mortality of nyala Tragelaphus angasi in Zululand, South Africa
Authors: Anderson J. L.
Published: August 2010

The kidney fat index (KFI) was used to examine the condition of nyala over a 27‐m‐onth period. From a sample in which both marrow fat and KFI were examined, it was noted that, as has been found in other bovid, kidney fat was mobilized before marrow fat. Seasonal changes in condition were observed and correlated with the rainfall in the previous month. Following periods of less than 50 mm of rain, the larger adult males were in significantly poorer condition than other animals.

The sexual difference in condition is attributed to the differences in body size, where males of asymptotic body mass required 62% more kcal/day than asymptotic mass females. When die‐offs occurred during periods of nutritional stress, significantly more old adults died than would be expected. Further, significantly more males died than females.