bluuebunny/crossref_metadata_2025 huggingface dataset:
High incidence of cholesterol gallstone disease in type 1 Gaucher disease: characterizing the biliary phenotype of type 1 Gaucher disease
Authors: Taddei Tamar H. , Dziura James , Chen Shu , Yang Ruhua , Hyogo Hideyuki , Sullards Cameron , Cohen David E. , Pastores Gregory , Mistry Pramod K.
Published: March 2010

Background

In Gaucher disease (GD), lysosomal glucocerebrosidase deficiency results in glucosylceramide accumulation in macrophage lysosomes. Hepatocytes do not accumulate glucosylceramide due in part to biliary secretion. Although gallstones (GS) occur in type 1 Gaucher disease (GD1), the chemical nature of stones, their association with metabolic parameters, and whether bile composition is altered are not understood. We assessed the prevalence of GS, their chemical composition, biliary lipids, and associated metabolic factors.

Methods

The study cohort comprised 417 patients comprehensively evaluated for GD1 severity. Ascertainment of GS, fasting lipoprotein profile, and bile lipid analyses were performed.

Results

The prevalence of GS in GD1 was 32%. Compared with men, the prevalence of GS was higher in women, increasing from 4.2% and 11.8% at age 20–29 years to 71% and 60% at age >70 years, respectively. Patients with GS were more likely to be asplenic (p < 0.0001), older (p < 0.0001), have higher low‐density lipoprotein (LDL) cholesterol (p = 0.002), and more severe GD1 disease compared with those without GS. On multiple logistic regression analysis, factors associated with GS were age (p < 0.001), female sex (p = 0.03), and splenectomy (p = 0.005). Compared with the general population, prevalence of GS was ∼5‐fold higher. Bile lipid analyses revealed cholesterol stones in five patients and pigment stones in one. Bile lipid composition was abnormal and contained glucosylceramide.

Conclusions

Our results point to a metabolic syndrome in GD1 consisting of a propensity to cholesterol GS, low high‐density lipoprotein (HDL) cholesterol, LDL cholesterol, and body mass index (BMI) associated with abnormal biliary lipid secretion.
Should transcobalamin deficiency be treated aggressively?
Authors: Schiff Manuel , Ogier de Baulny Hélène , Bard Ghislaine , Barlogis Vincent , Hamel Christian , Moat Stuart J. , Odent Sylvie , Shortland Graham , Touati Guy , Giraudier Stéphane
Published: March 2010

Transcobalamin (transcobalamin II, TC) transports plasma vitamin B12 (cobalamin, Cbl) into cells. TC deficiency is a rare autosomal recessive disorder causing intracellular Cbl depletion, which in turn causes megaloblastic bone marrow failure, accumulation of homocysteine and methylmalonic acid, and methionine depletion. The clinical presentation reflects intracellular Cbl defects, with early‐onset failure to thrive with gastrointestinal symptoms, pancytopenia, and megaloblastic anemia, sometimes followed by neurological complications. We report the clinical, biological, and molecular findings and the outcome in five TC‐deficient patients. The three treated early had an initial favorable outcome, whereas the two treated inadequately had late‐onset severe neuro‐ophthalmological impairment. Even if the natural course of the disease over time might also result in late‐onset symptoms in the aggressively treated patients, these data emphasize that TC deficiency is a severe disorder requiring early detection and probably long‐term aggressive therapy. Mutation analysis revealed six unreported mutations in the TCN2 gene. In silico structural analysis showed that these mutations disrupt the Cbl‐TC interaction domain and/or the putative transcobalamin–transcobalamin receptor interaction domain.
Health Care Professionals’ Views of Sharing Information with Families Who Have a Child with a Genetic Condition
Authors: Gallo Agatha M. , Angst Denise B. , Knafl Kathleen A. , Twomey John G. , Hadley Emily
Published: March 2010

The purpose of this study was to examine health care professionals’ views and strategies for individualizing information sharing in families who have a child with a genetic condition. The sample consisted of 37 health professionals from three clinical sites in the greater metropolitan area of a large Midwestern city. Qualitative content thematic analysis was used to analyze data from the health professionals’ semi‐structured interviews. Four themes captured how health care professionals work with families around information management: Sharing Information with Parents, Taking into Account Parental Preferences, Understanding of the Condition, and Helping Parents Inform Others. These findings contribute to understanding the processes that health professionals use in sharing information with parents who have children with a genetic condition, and they provide guidance for clinical practice, professional training, and future research.
Corpectomy and circumferential spinal fusion in dystrophic neurofibromatous curves
Authors: Shahcheraghi G. Hossain , Tavakoli Ali Reza
Published: March 2010

Purpose

Spinal deformity in neurofibromatosis, when associated with dystrophic change, is a major treatment challenge. Early anterior and posterior spinal fusion is the accepted treatment plan for severe progressive kyphoscoliosis. Resection of the vertebral body as an additional step in correction and fusion has not been previously investigated. Information on the functional status of the neurofibromatous curves is also scarce in the literature. The purpose of this study is to report an experience with corpectomy and circumferential fusion in dystrophic spines of neurofibromatosis.

Methods

Among 16 patients with dystrophic spinal curves, nine cases who had undergone anterior and posterior fusion with 6.7 years (range 2–11.9) average follow-up were evaluated clinically, radiographically, and functionally (SRS-22).

Results

Nine cases with a mean age of 11.8 years (range 7.8–17) at surgery consisted of seven kyphoscoliotic patients, who had received one or two levels of cord decompression and corpectomy, and two cases of scoliosis with hypokyphosis. Surgery improved the mean preoperative scoliosis of 87 (range 60–110) and local kyphosis of 69.3° (range 50–100) to 49 (range 15–85) and 49° (range 35–70), respectively. Loss of correction of 5° in the scoliosis and 13° in the kyphosis angles was observed in the final follow-up. One surgery resulted in an immediate postoperative mortality. Fusion was achieved in all cases. The average SRS-22 score of 4.1 (range 3–4.6) was obtained.

Conclusions

Simultaneous anterior and posterior fusion with corpectomy for dystrophic neurofibromatous spinal deformities is associated with a high fusion rate, good correction, and also good functional outcome.
Contribution of peripheral endothelin ETA and ETB receptors in neuropathic pain induced by spinal nerve ligation in rats
Authors: Werner Maria Fernanda P. , Trevisani Marcello , Campi Barbara , André Eunice , Geppetti Pierangelo , Rae Giles A.
Published: March 2010

Endothelins (ETs) contribute to the sensory changes seen in animals models of inflammatory, cancer and diabetic neuropathic pain, but little is known about their nociceptive role following peripheral nerve injury. The current study evaluated mechanisms by which ETs can drive changes in nociceptive responses to thermal stimulation of the hind paw of rats induced by unilateral lumbar L5/L6 spinal nerve ligation (SNL) injury. SNL sensitizes rats to acetone‐evoked cooling of and radiant heat application (Hargreaves test) to the ipsilateral hind paw (throughout 3–40 and 9–40 days after surgery, respectively). At 12 days after SNL, intraplantar (i.pl.) injection of endothelin‐1 (ET‐1, 10 pmol) induces greater overt nociception that was reduced only by treatment with the selective ETA peptidic antagonist (BQ‐123, 10 nmol, i.pl), but unchanged by the selective ETB peptidic antagonist (BQ‐788). Cold allodynia evoked by cooling the ipsilateral hind paw with acetone was reduced by i.pl. injection of both antagonists BQ‐123 or BQ‐788 (3 or 10 nmol). In contrast, heat hyperalgesia evaluated by Hargreaves method was reduced only by BQ‐123. SNL enhanced the [Ca+2]
i increases induced by ET‐1 (100 nM) in neurons from L5/L6 (injured) and L4 (intact) cultured dorsal root ganglion, but did not change the responses of non‐neuronal cells. Furthermore, Western blot analysis revealed that SNL increased ETA and ETB receptor protein expression in spinal nerves. Thus, SNL induces marked hind paw hypersensitivity to thermal stimulation in part via up‐regulation of peripheral sensory nerve pronociceptive ETA and ETB receptor‐operated mechanisms.
99mTc-DTPA diuretic renal scintigraphy in cats with nephroureterolithiasis
Authors: Hecht Silke , Lawson Sarah M. , Lane India F. , Sharp Dorothy E. , Daniel Gregory B.
Published: March 2010

The purpose of this study was to evaluate results of diuretic renal scintigraphy in 32 feline kidneys with nephroureterolithiasis and variable degrees of renal pelvis/ureteral dilation. Six kidneys showed a non-obstructive scintigraphic pattern, with a downward slope of time-activity curves (TAC) and a median excretion half-time of radiopharmaceutical (T½) of 6.09 (5.08–8.43) min. Eight kidneys showed an obstructive pattern, with a continuous rise of TAC and median T½ of −7.91 (−43.13–0.00) min. In one kidney with presumptive partial obstruction scintigraphic results were equivocal. Seventeen kidneys, most of which had an individual kidney glomerular filtration rate below 0.5 ml/min/kg, had non-diagnostic studies. Diuretic renal scintigraphy may be a useful adjunct modality in the diagnosis of ureteral obstruction in some cats if renal function is maintained. However, the large number of non-diagnostic studies in animals with decreased renal function represents a clear limitation of the technique.
Virgin olive oil administration improves the effect of aspirin on retinal vascular pattern in experimental diabetes mellitus
Authors: De La Cruz Jose Pedro , Del Río Sergio , López-Villodres Juan Antonio , Villalobos Maria Auxiliadora , Jebrouni Nuria , González-Correa Jose Antonio
Published: March 2010

The aim of the present study is to evaluate the possible influence of virgin olive oil (VOO) on the effect of acetylsalicylic acid (ASA) in platelet aggregation, prostanoid and NO production and retinal vascular pattern in rats with experimental type 1-like diabetes. We used 100 male Wistar rats that were distributed into five groups: (1) non-diabetic rats (NDR); (2) untreated diabetic rats (DR); (3) DR treated with ASA (2 mg/kg per d per os (p.o.)); (4) DR treated with VOO (0·5 ml/kg per d p.o.); (5) DR treated with ASA plus VOO. The duration of diabetes was 3 months, and each treatment was administered from the first day of diabetes. Variables that were quantified were platelet aggregation (Imax), thromboxane B2(TxB2), aortic prostacyclin (6-keto-PGF1α) and NO, and the percentage of retina with horseradish peroxidase-permeable vessels (HRP-PV). Diabetic rats showed a higherImax(35 %) and TxB2(63 %) than NDR, and a lower 6-keto-PGF1α, NO and HRP-PV than NDR ( − 74·6 %). ASA and VOO administration reduced these differences and prevented the percentage of HRP-PV ( − 59·7 % with ASA and − 46·7 % with VOO). The administration of ASA plus VOO showed a strong platelet inhibition (80·2v.23·4 % for VOO and 50·6 % for ASA+VOO,P < 0·0001), and reduced HRP-PV differences to − 31·6 % (P < 0·001 with respect to DR andP < 0·0001 with respect to DR treated with ASA). In conclusion, the administration of VOO to rats with type 1-like diabetes mellitus improves the pharmacodynamic profile of ASA, and increases its retinal anti-ischaemic effect.
A SUFFICIENT CONDITION FOR A GRAPH TO BE A FRACTIONAL (f, n)-CRITICAL GRAPH
Authors: ZHOU SIZHONG
Published: March 2010

Let a, b and n be non-negative integers such that 1 ≤ a ≤ b, and let G be a graph of order p with $\(p\geq\frac{(a+b-1)(a+b-2)+bn-2}{a}\)$ and f be an integer-valued function defined on V(G) such that a ≤ f(x) ≤ b for all x ∈ V(G). Let h: E(G) → [0, 1] be a function. If ∑e∋xh(e) = f(x) holds for any x ∈ V(G), then we call G[Fh] a fractional f-factor of G with indicator function h, where Fh = {e ∈ E(G): h(e) > 0}. A graph G is called a fractional (f, n)-critical graph if after deleting any n vertices of G the remaining graph of G has a fractional f-factor. In this paper, it is proved that G is a fractional (f, n)-critical graph if $\(|N_G(X)|>\frac{(b-1)p+|X|+bn-1}{a+b-1}\)$ for every non-empty independent subset X of V(G), and $\(\delta(G)>\frac{(b-1)p+a+b+bn-2}{a+b-1}\)$. Furthermore, it is shown that the result in this paper is best possible in some sense.
Modelling egg production and nutrient responses in broiler breeder hens
Authors: GOUS R. M. , NONIS M. K.
Published: March 2010

The model described simulates the response of a population of broiler breeders to a daily allowance of a feed of specified composition for up to 280 days from sexual maturity. The population is generated using normally distributed values for initial bodyweight, initial body lipid and protein weight, age at first egg, yolk weight constant and ‘aggressiveness’, the latter producing different feed intakes around the controlled mean. Age at sexual maturity for each bird is predicted from bodyweight and from information about rearing lighting programmes. Egg production, clutch patterns, yolk weights, egg component weights, double-yolked eggs, internal laying and soft-shelled eggs are predicted. Body protein growth, including feathers, is assumed to cease at sexual maturity, thus bodyweight changes after maturity are due entirely to accumulation or utilization of lipid.

Energy transactions are expressed in units of effective energy. Protein required for egg production is calculated from the composition of the next egg to be laid and an assumed fixed chemical composition. Assumptions for protein partition rules are that maintenance has highest priority, yolk protein deposition second and albumen protein third. Provided that sufficient energy and nutrients are available, yolk protein deposition is assumed to occur continuously to meet the predicted growth rate, unless inter-clutch intervals exceed 2 days (user defined), when yolk growth ceases. Energy and nutrients (amino acids) for albumen production accumulate in a pool which has some controlling influence over ovulation. If the energy and nutrients in the albumen pool will support the predicted development of the next egg then ovulation will occur, otherwise ovulation is delayed until sufficient energy and nutrients are available. All events are timed within a 24 h day assuming that feeding is at one time in the morning.

The desired feed intake is calculated each day according to the supply of the first limiting energy or nutrient (invariably an amino acid) in relation to potential need. Actual feed intake is either the desired intake or the feed allowance, whichever is the lower. The additional energy required for thermogenesis is taken into account, but not the constraining effects of high temperature or the bulkiness of the food as a constraint to voluntary food intake.

Some shortcomings of the current model are discussed, these being areas suitable for further research on broiler breeder nutrition.
The effect of Reynolds number on the dynamics and wakes of freely rising and falling spheres
Authors: HOROWITZ M. , WILLIAMSON C. H. K.
Published: March 2010

In this paper, we study the effect of the Reynolds number (Re) on the dynamics and vortex formation modes of spheres rising or falling freely through a fluid (whereRe= 100–15000). Since the oscillation of freely falling spheres was first reported by Newton (University of California Press, 3rd edn, 1726, translated in 1999), the fundamental question of whether a sphere will vibrate, as it rises or falls, has been the subject of a number of investigations, and it is clear that the mass ratiom* (defined as the relative density of the sphere compared to the fluid) is an important parameter to define when vibration occurs. Although all rising spheres (m* < 1) were previously found to oscillate, either chaotically or in a periodic zigzag motion or even to follow helical trajectories, there is no consensus regarding precise values of the mass ratio (m*crit) separating vibrating and rectilinear regimes. There is also a large scatter in measurements of sphere drag in both the vibrating and rectilinear regimes.

In our experiments, we employ spheres with 133 combinations ofm* andRe, to provide a comprehensive study of the sphere dynamics and vortex wakes occurring over a wide range of Reynolds numbers. We find that falling spheres (m* > 1) always move without vibration. However, in contrast with previous studies, we discover that a whole regime of buoyant spheres rise through a fluid without vibration. It is only when one passes below a critical value of the mass ratio, that the sphere suddenly begins to vibrate periodically and vigorously in a zigzag trajectory within a vertical plane. The critical mass is nearly constant over two ranges of Reynolds number (m*crit≈ 0.4 forRe= 260–1550 andm*crit≈ 0.6 forRe> 1550). We do not observe helical or spiral trajectories, or indeed chaotic types of trajectory, unless the experiments are conducted in disturbed background fluid. The wakes for spheres moving rectilinearly are comparable with wakes of non-vibrating spheres. We find that these wakes comprise single-sided and double-sided periodic sequences of vortex rings, which we define as the ‘R’ and ‘2R’ modes. However, in the zigzag regime, we discover a new ‘4R’ mode, in which four vortex rings are created per cycle of oscillation. We find a number of changes to occur at a Reynolds number of 1550, and we suggest the possibility of a resonance between the shear layer instability and the vortex shedding (loop) instability. From this study, ensuring minimal background disturbances, we have been able to present a new regime map of dynamics and vortex wake modes as a function of the mass ratio and Reynolds number {m*,Re}, as well as a reasonable collapse of the drag measurements, as a function ofRe, onto principally two curves, one for the vibrating regime and one for the rectilinear trajectories.
Direct simulation of turbulent swept flow over a wire in a channel
Authors: RANJAN R. , PANTANO C. , FISCHER P.
Published: March 2010

Turbulent swept flow over a cylindrical wire placed on a wall of a channel is investigated using direct numerical simulations. This geometry is a model of the flow through the wire-wrapped fuel pins, the heat exchanger, typical of many nuclear reactor designs. Mean flow along and across the wire axis is imposed, leading to the formation of separated flow regions. The Reynolds number based on the bulk velocity along the wire axis direction and the channel half height is 5400 and four cases are simulated with different flowrates across the wire. This configuration is topologically similar to backward-facing steps or slots with swept flow, except that the dominant flow is along the obstacle axis in the present study and the crossflow is smaller than the axial flow, i.e. the sweep angle is large. Mean velocities, turbulence statistics, wall shear stress and instantaneous flow structures are investigated. Particular attention is devoted to the statistics of the shear stress on the walls of the channel and the wire in the recirculation zone. The flow around the mean reattachment region, at the termination of the recirculating bubble, does not exhibit the typical decay of the mean shear stress observed in classical backward-facing step flows owing to the presence of a strong axial flow. The evolution of the mean wall shear stress angle after reattachment indicates that the flow recovers towards equilibrium at a rather slow rate, which decreases with sweep angle. Finally, the database is analysed to estimate resolution requirements, in particular around the recirculation zones, for large-eddy simulations. This has implications in more complete geometrical models of a wire-wrapped assembly, involving hundreds of fuel pins, where only turbulence modelling can be afforded computationally.
Race/ethnic differences in exposure to traumatic events, development of post-traumatic stress disorder, and treatment-seeking for post-traumatic stress disorder in the United States
Authors: Roberts A. L. , Gilman S. E. , Breslau J. , Breslau N. , Koenen K. C.
Published: March 2010

Background

To identify sources of race/ethnic differences related to post-traumatic stress disorder (PTSD), we compared trauma exposure, risk for PTSD among those exposed to trauma, and treatment-seeking among Whites, Blacks, Hispanics and Asians in the US general population.

Method

Data from structured diagnostic interviews with 34 653 adult respondents to the 2004–2005 wave of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were analysed.

Results

The lifetime prevalence of PTSD was highest among Blacks (8.7%), intermediate among Hispanics and Whites (7.0% and 7.4%) and lowest among Asians (4.0%). Differences in risk for trauma varied by type of event. Whites were more likely than the other groups to have any trauma, to learn of a trauma to someone close, and to learn of an unexpected death, but Blacks and Hispanics had higher risk of child maltreatment, chiefly witnessing domestic violence, and Asians, Black men, and Hispanic women had higher risk of war-related events than Whites. Among those exposed to trauma, PTSD risk was slightly higher among Blacks [adjusted odds ratio (aOR) 1.22] and lower among Asians (aOR 0.67) compared with Whites, after adjustment for characteristics of trauma exposure. All minority groups were less likely to seek treatment for PTSD than Whites (aOR range: 0.39–0.61), and fewer than half of minorities with PTSD sought treatment (range: 32.7–42.0%).

Conclusions

When PTSD affects US race/ethnic minorities, it is usually untreated. Large disparities in treatment indicate a need for investment in accessible and culturally sensitive treatment options.
The emerging biology of delusions
Authors: Murray G. K.
Published: March 2010

This article examines a model of how delusions may arise, not just in schizophrenia but also in a number of neurological and psychiatric conditions, through a combination of dysregulated dopamine release from ascending midbrain pathways and reasoning bias. Negative symptoms may also be related to dopamine dysregulation, with the precise mixture of positive and negative symptoms depending on the relative degree of dopamine dysregulation in particular mesocorticolimbic circuits. Evidence for this model is examined, and predictions arising from this model are described.
Developmental trajectories of psychotic-like experiences across adolescence: impact of victimization and substance use
Authors: Mackie C. J. , Castellanos-Ryan N. , Conrod P. J.
Published: March 2010

Background

Research suggests that psychotic-like experiences (PLEs) in the general population are common, but can reflect either transitory or persistent developmental phenomena. Using a general adolescent population it was examined whether different developmental subtypes of PLEs exist and whether different trajectories of PLEs are associated with certain environmental risk factors, such as victimization and substance use.

Method

Self-reported PLEs were collected from 409 adolescents (mean age 14 years 7 months) at four time points, each 6 months apart. General growth mixture modelling was utilized to identify classes of adolescents who followed distinct trajectories of PLEs across this period. Predictors of class membership included demographics, personality, victimization, depression, anxiety and substance use.

Results

We identified the following three developmental subgroups of PLEs: (1) persistent; (2) increasing; (3) low. Adolescents on the persistent trajectory reported frequent victimization and consistent elevated scores in depression and anxiety. Adolescents on the increasing trajectory were engaging in cigarette use prior to any increases in PLEs and were engaging in cocaine, cannabis and other drug use as PLEs increased at later time points.

Conclusions

The findings suggest that different developmental subgroups of PLEs exist in adolescence and are differentially related to victimization and substance use.
Frank Tannenbaum and the Mexican Revolution
Authors: Knight Alan
Published: March 2010

This article examines Frank Tannenbaum's engagement with Mexico in the crucial years following the Revolution of 1910–1920 and his first visit to the country in 1922. Invited—and feted—by the government and its powerful labor allies, Tannenbaum soon expanded his initial interest in organized labor and produced a stream of work dealing with trade unions, peasants, Indians, politics, and education—work that described and often justified the social program of the Revolution, and that, rather surprisingly, continued long after the Revolution had lost its radical credentials in the 1940s. Tannenbaum's vision of Mexico was culturalist, even essentialist; more Veblenian than Marxist; at times downright folkloric. But he also captured important aspects of the process he witnessed: local and regional variations, the unquantifiable socio-psychological consequences of revolution, and the prevailing concern for order and stability. In sum, Tannenbaum helped establish the orthodox—agrarian, patriotic, and populist—vision of the Revolution for which he has been roundly, if sometimes excessively, criticized by recent “revisionist” historians; yet his culturalist approach, with its lapses into essentialism, oddly prefigures the “new cultural history” that many of these same historians espouse.
Introduction: Good Things Come to Those Who Negotiate
Authors: Cobble Dorothy Sue
Published: March 2010

On May 15, 2008, the Harvard Union of Clerical and Technical Workers (HUCTW) held its twentieth birthday celebration at the Agassiz Theatre in Radcliffe Yard. I was next door at Harvard University's Schlesinger Library, sleepily perusing my next fat folder of government documents. As the laughter and singing wafted its way across the quad, the choice of whether to stay or go was clear. I followed the trail of balloons to the theater, grabbed my complimentary union tote bag, smiled at all the lovingly crafted refreshments that awaited the revelers, and squeezed into a tiny space in the front as the lights went down. Long familiar with the upbeat and bold spirit of the union, I was still caught off guard when the lights came back up. Seated a few feet from me on the stage was a 1940s femme fatale who began to belt out “A Union Is a Girl's Best Friend.”
Diet composition of the invasive red-whiskered bulbul Pycnonotus jocosus in Mauritius
Authors: Linnebjerg Jannie Fries , Hansen Dennis M. , Bunbury Nancy , Olesen Jens M.
Published: March 2010

Disruption of ecosystems is one of the biggest threats posed by invasive species (Mack et al. 2000). Thus, one of the most important challenges is to understand the impact of exotic species on native species and habitats (e.g. Jones 2008). The probability that entire ‘invasive communities’ will develop increases as more species establish in new areas (Bourgeois et al. 2005). For example, introduced species may act in concert, facilitating one another's invasion, and increasing the likelihood of successful establishment, spread and impact. Simberloff & Von Holle (1999) introduced the term ‘invasional meltdown’ for this process, which has received widespread attention since (e.g. O'Dowd 2003, Richardson et al. 2000, Simberloff 2006). Positive interactions among introduced species are relatively common, but few have been studied in detail (Traveset & Richardson 2006). Examples include introduced insects and birds that pollinate and disperse exotic plants, thereby facilitating the spread of these species into non-invaded habitats (Goulson 2003, Mandon-Dalger et al. 2004, Simberloff & Von Holle 1999). From a more general ecological perspective, the study of interactions involving introduced and invasive species can contribute to our knowledge of ecological processes – for example, community assembly and indirect interactions.
Termite diversity and abundance across fire-induced habitat variability in a tropical moist savanna (Lamto, Central Côte d'Ivoire)
Authors: Dosso Kanvaly , Konaté Souleymane , Aidara Daouda , Linsenmair K. E.
Published: March 2010

At Lamto, little is known about animal community responses to habitat variability resulting from fires and the mosaic pattern of the vegetation in general and in particular about that of termites which play key roles in this ecosystem. With a standardized method, data were collected on termites from four habitats differing in their vegetation cover and fire-history: annually burned savanna, savanna woodland, forest island and gallery forest. A range of environmental variables was measured and correlated with species abundances. The number of termite species collected in the savanna woodland was very close to that found in the gallery forest while the forest island was the richest habitat. The species richness of the savanna woodland and forest island seemed partly due to their heterogeneous and transitional vegetation structures and variable food resources. With regard to the fire-history of habitats, Connell's intermediate disturbance hypothesis offers an explanation for differences in the patterns of habitat-specific species richness. Variation in species abundances was significantly correlated with only two environmental variables (soil pH and woody plant species richness). The pH appeared as the most influential factor for fungus-growers while tree invasion in the savanna strongly reduces the abundance of grass-feeding species (e.g. Trinervitermes geminatus). Although not significantly correlated with species abundances, soil carbon showed a positive correlation with the dominant soil-feeder Basidentitermes potens. As for wood-feeders, they were not strongly correlated with woody plant species richness; this fact might be linked to their use for other sources of nourishment. Overall, it appears that habitat variability in the Lamto reserve contributes to the maintenance of different subsets of the termite community.
Estimation of root biomass based on excavation of individual root systems in a primary dipterocarp forest in Pasoh Forest Reserve, Peninsular Malaysia
Authors: Niiyama Kaoru , Kajimoto Takuya , Matsuura Yojiro , Yamashita Tamon , Matsuo Naoko , Yashiro Yuichiro , Ripin Azizi , Kassim Abd. Rahman , Noor Nur Supardi
Published: March 2010

Precise estimation of root biomass is important for understanding carbon stocks and dynamics in tropical rain forests. However, limited information is available on individual root masses, especially large trees. We excavated 121 root systems of various species (78) and sizes (up to 116 cm in dbh), and estimated both above- and below-ground biomass in a lowland primary dipterocarp forest in the Pasoh Forest Reserve, Peninsular Malaysia. A tree census was conducted in four research plots (each 0.2 ha) and stand-level biomass was estimated. We examined relationships between tree size parameters and masses of coarse roots (roots ≥5 mm in diameter) and derived a dbh-based allometric equation. The amounts of coarse roots that were lost during excavation were corrected. Coarse-root biomass before and after correction for lost roots was estimated to be 63.8 and 82.7 Mg ha−1, indicating that significant amounts of roots (23%) were lost during the sampling. We also estimated the biomass of small root (<5 mm) by applying pipe-model theory. The estimate, 13.3 Mg ha−1, was similar to another estimate of small roots, 16.4 Mg ha−1, which was obtained directly by the soil-pit sampling method. Total below-ground (BGB) and above-ground biomass (AGB) was estimated to be 95.9 and 536 Mg ha−1, respectively. The biomass-partitioning ratio (BGB/AGB) was about 0.18. In conclusion, the dbh-based allometric equation for coarse roots developed in this study, which kept good linearity even including the data of larger trees, might be useful for evaluating below-ground carbon stocks in other stands of similar forest (old-growth dipterocarp) in South-East Asia.
Temporal separation between jaguar and puma in the dry forests of southern Bolivia
Authors: Romero-Muñoz Alfredo , Maffei Leonardo , Cuéllar Erika , Noss Andrew J.
Published: March 2010

Despite the potential importance of temporal separation for the coexistence of competing species, no study has found significant segregation at the circadian level between jaguar (Panthera onca) and puma (Puma concolor) in sympatry. Using data from camera trap surveys (wet and dry seasons), we have evaluated the activity patterns of both species and their potential prey at four areas in the dry forest of the Bolivian Chaco. We tested if temporal separation existed between these two species, and if their activity was related to that of a particular prey. At most sites, activity patterns of jaguar and puma did not vary significantly between seasons, except for puma at one site. There were no differences between sexes for any cat species at any site. At three sites we found statistically significant differences in the activity patterns of jaguar and puma, as they showed a clear temporal segregation. None of them followed the activity patterns of any particular prey species across sites. The latter suggests that segregation is influenced by avoidance behaviour between the two felid species. Therefore, temporal separation may be an important behavioural factor promoting the coexistence of jaguar and puma in some areas of this dry forest.
Reproductive biology of Macleania rupestris (Ericaceae), a pollen-limited Neotropical cloud-forest species in Costa Rica
Authors: Fuchs Eric J. , Ross-Ibarra Jeffrey , Barrantes Gilbert
Published: March 2010

The reproductive success of hummingbird-pollinated plants often depends on complex interactions between environmental conditions and pollinator biology (Navarro 1999, Stiles 1985, Wolf et al. 1976). The effect of environment on reproductive success of hummingbird-pollinated plants is particularly pronounced at high altitudes, where large daily fluctuations in temperature, relative humidity and solar radiation limit the effective time for photosynthesis (Cavieres et al. 2000) and affect foraging activity (Navarro 1999) and abundance of pollinators (Rahbek 1997). At high altitudes in the tropical cloud forests of Costa Rica these factors may have serious impacts on fruit production.
Polarized-Light Interferometry of Calcium Carbonate Deposition in Moss from a Waterfall on the Niagara Escarpment
Authors: Swatland Howard J.
Published: March 2010

Deposition of calcium carbonate from groundwater was examined on a moss, Didymodon tophaceus, from a Niagara Escarpment waterfall. A spectrophotometer on a polarizing microscope was used for interferometry. A second-order blue interference with an interference minimum around 620 nm was found when moss cell spaces were fully calcified. Filled cell spaces were often surrounded by empty cell spaces. Complete calcification of whole leaflets resulted in progressively higher orders of interference colors and a positive shift in interference minima. Calcified leaflets finally became cemented together, but each retained a weak extinction when rotated. Small calcareous spherulites (mean diameter 15.7 ± 2.1 μm) were found between leaflets. Spherulites exhibited first-order white interference with a Maltese cross that rotated when the polarizer and analyzer were rotated in tandem. A Nikitin-Berek compensator was tilted at 5.5° to give an interference minimum at 600 nm in the optical axis. Quadrants of spherulites with radii more or less in line with the tilting axis of the compensator had lower (P < 0.001) interference minima (535 ± 27 nm) than quadrants with radii more or less perpendicular to the compensator (659 ± 15 nm), thus indicating a radial internal structure. Spherulites were tentatively identified as vaterite.
Global benefits, local burdens? The paradox of governing biofuels production in Kansas and Iowa
Authors: Selfa Theresa
Published: March 2010

Recent sociological analysis of the expansion of the biofuels industry internationally has noted the paradox between the purported global environmental benefits of reducing greenhouse gas emissions by replacing fossil fuels with biofuels, and the potential for distinctly negative environmental impacts experienced at local sites of biofuels production. The state, in both the USA and the EU, has played a prominent role in promoting the development and expansion of biofuels production through government mandates and incentives, but the state's role in governing the potentially (negative) economic, social or environmental impacts of biofuels production on local communities has been much more limited in scope. We review the environmental sociological literature to frame analysis of how the state is governing the benefits and burdens brought by the ethanol industry to rural communities in Kansas and Iowa. Drawing on data from community surveys, focus group and individual interviews and analysis of environmental violations, the paper examines the local impacts of biofuels production in three case-study communities. Findings suggest that local residents do not express many concerns about environmental impacts and that the state has played a modest role in governing the negative local environmental impacts. We argue that this lack of concern is related to the histories of these rural communities, which have long depended on resource extractive industries and currently are desperate for economic growth. We find that criticisms of negative environmental impacts are muted in relation to purported economic benefits and to other comparable industries. These community case studies illustrate some of the challenges, both at the practical and theoretical levels, of governing biofuels production.
New estimation of N2 fixation in the western and central Pacific Ocean and its marginal seas
Authors: Shiozaki Takuhei , Furuya Ken , Kodama Taketoshi , Kitajima Satoshi , Takeda Shigenobu , Takemura Toshihiko , Kanda Jota
Published: March 2010

The distribution of N2 fixation was examined using a 15N2 tracer with accompanying measurements of abundance of Trichodesmium spp. and Richelia intracellularis, nitrate plus nitrite (N+N) and soluble reactive phosphorus at the nanomolar level, and primary production in the western and central Pacific Ocean. N2 fixation occurred only in >∼20°C oligotrophic (i.e., N+N < 100 nM) waters except at a station in the equatorial upwelling zone where N+N was 1880 nM. High N2 fixation rates were observed in the Kuroshio and East China Sea (KECS) and near Fiji and other isolated islands with concomitant high abundance of Trichodesmium spp. In contrast, N2 fixation in the western and central oligotrophic North Pacific (WCONP) was significantly lower, and Trichodesmium spp. were rarely observed. These observations hint that KECS and waters around isolated islands are N2 fixation “hot spots” because of the occurrence of Trichodesmium spp. The average N2 fixation rate in the KECS of 232 ± 54.8 (±SE, n = 13) μmol N m−2 d−1 was almost 1 order of magnitude higher than that in the WCONP of 39.2 ± 7.51 (n = 26) μmol N m−2 d−1. On the basis of these estimates and reported values obtained using 15N2, depth‐integrated N2 fixation in the North Pacific was estimated to be 2.6 ± 0.3 × 109 (n = 63) mol N d−1, which is less than half of previous estimates. This difference was ascribed primarily to the unavailability of N2 fixation rates in the WCONP, which occupies a vast area of the subtropical North Pacific, and the use of data obtained in the hot spots which represent small areas that likely led to the previous overestimation.
Spatial variabilities and their relationships of the trends of temperature, water vapor, and precipitation in the North American Regional Reanalysis
Authors: Lu Er , Takle Eugene S.
Published: March 2010

Spatial variabilities and their relationships of the trends of temperature, water vapor, and precipitation in the North American Regional Reanalysis are examined for each season from March 1979 to February 2007. Results show that warming dominates the domain in the troposphere from the surface to 300 hPa. Water vapor increases at lower levels but does not change much at mid‐upper levels. Because of the large increase of water vapor holding capacity of the air at all levels due to the warming, relative humidity has a decreasing trend at all levels. The decrease is small at the surface and largest at midlevels. Precipitation, which corresponds well to ascending motion in trends, both increases and decreases in about half of the domain. Statistical analysis from the very large spatial samples indicates that the precipitation trend positively relates to both specific humidity trend and relative humidity trend. However, temperature trend positively relates to specific humidity trend but negatively relates to relative humidity trend. So, in strong warming places, whether precipitation increases or not depends on whether the decrease of relative humidity becomes a limiting factor; small decrease of relative humidity may still allow precipitation to increase, but large decrease of relative humidity may make precipitation decrease. The uncertain relationship between the trends of precipitation and temperature can also be understood from the nonlinear characteristics of the atmospheric processes.
A multisite seasonal ensemble streamflow forecasting technique
Authors: Bracken Cameron , Rajagopalan Balaji , Prairie James
Published: March 2010

We present a technique for providing seasonal ensemble streamflow forecasts at several locations simultaneously on a river network. The framework is an integration of two recent approaches: the nonparametric multimodel ensemble forecast technique and the nonparametric space‐time disaggregation technique. The four main components of the proposed framework are as follows: (1) an index gauge streamflow is constructed as the sum of flows at all the desired spatial locations; (2) potential predictors of the spring season (April–July) streamflow at this index gauge are identified from the large‐scale ocean‐atmosphere‐land system, including snow water equivalent; (3) the multimodel ensemble forecast approach is used to generate the ensemble flow forecast at the index gauge; and (4) the ensembles are disaggregated using a nonparametric space‐time disaggregation technique resulting in forecast ensembles at the desired locations and for all the months within the season. We demonstrate the utility of this technique in skillful forecast of spring seasonal streamflows at four locations in the Upper Colorado River Basin at different lead times. Where applicable, we compare the forecasts to the Colorado Basin River Forecast Center's Ensemble Streamflow Prediction (ESP) and the National Resource Conservation Service “coordinated” forecast, which is a combination of the ESP, Statistical Water Supply, a principal component regression technique, and modeler knowledge. We find that overall, the proposed method is equally skillful to existing operational models while tending to better predict wet years. The forecasts from this approach can be a valuable input for efficient planning and management of water resources in the basin.
HMGA1a induces aberrant splicing of estrogen receptor α in MCF-7 breast cancer cells
Authors: Ohe Kenji , Utsumi Toshiaki , Mayeda Akila
Published: March 2010

The well known transcription factor, HMGA1a, also known as an oncogene, causes aberrant splicing of Presenilin-2 found in sporadic Alzheimer's disease, through sequence specific RNA binding. Since HMGA1 protein levels correlate with tumorigenic malignancy, we are interested in the potential of HMGA1a as an aberrant splicing factor in cancer. The N-terminal truncated isoform of Estrogen Receptor alpha, ERα46, is known to increase expression when breast cancer cells (MCF-7) become hyperconfluent. Transiently expressed HMGA1a induced ERα46 mRNA expression. Plasmid driven micro RNA containing the presenilin-2 HMGA1a RNA binding site and a micro RNA nuclear localization signal (miRHMGBSNLS), inhibited ERα46 mRNA expression, acting as a decoy. Re-expressing HMGA1a restored ERα46 mRNA expression. An HMGA1a binding site was found in the skipped exon 1A, 33 bp upstream the authentic 5’ splice site, adjacent a pseudo 5’ splice site. RNA gel shift assay showed binding of HMGA1a to this site. Exon skipping by HMGA1a and exon inclusion by the HMGA1a binding site decoy could be reproduced in vitro in a heterologous context. Psoralen UV crosslinking showed HMGA1a anchored U1 snRNP to the upstream pseudo 5’ splice site. Psoralen UV crosslinking combined with antisense DNA oligo / RNaseH protection comfirmed U1 snRNP anchored to the upstream pseudo 5’ splice site by HMGA1a. This is the second example of the PSI model found in Drosophila, but the first in human. Finally, the stable transfectant of the decoy, miRHMGBSNLS (MCF-7 cells), which shows decreased ERα46 protein level, was prone to apoptosis by high dose estrogen. We hope this decoy, miR_HMGBS_NLS, in combination with high dose estrogen, will lead to development of a novel breast cancer therapy, an alternative of conventional estrogen deprivation.
Space-resolved extreme ultraviolet spectrometer for impurity emission profile measurement in Large Helical Device
Authors: Dong Chunfeng , Morita Shigeru , Goto Motoshi , Zhou Hangyu
Published: March 2010

A space-resolved extreme ultraviolet (EUV) spectrometer working in 60–400 Å range has been developed to observe impurity emission profiles in core and edge plasmas of Large Helical Device (LHD). A flat focus is made for plane surface detector by using a varied line spacing holographic grating with an angle of incidence of 87°. An excellent spectral resolution of 0.22 Å at 200 Å is then obtained after careful adjustment of the optical components. In the profile measurement of the LHD plasmas, the toroidal resolution is important as well as the radial resolution because the magnetic surfaces of LHD quickly change when the observation chord is tilted at a slightly different toroidal location. Horizontal dispersion is therefore selected for the present spectrometer. As a result, the toroidal resolution of 75 mm is achieved at the plasma position. An enough radial resolution of 10 mm is also obtained at spatial-resolution slit width of 0.2 mm. In order to measure the full radial profile of LHD plasmas the spectrometer is placed at a distance of ∼9200 mm away from the plasma center and a backilluminated charge-coupled device with a size of 6.6×26.6 mm2 is set vertical to the horizontal dispersion. Half of the LHD plasma, i.e., ∼50 cm, can be measured along the vertical direction at horizontally elongated plasma cross section. A full vertical profile can be obtained by changing the vertical angle of the EUV spectrometer. As an example the full vertical profile of edge C IV (312.4 Å) emission is presented. A wavelength interval of 35–65 Å can be simultaneously observed, which varies according to the wavelength to be measured. A local emission profile of Fe XX (132.67 Å) is also presented after Abel inversion as a typical example of the core EUV emission. Finally, the EUV spectrometer is absolutely calibrated using EUV bremsstrahlung continuum profile in comparison with absolute values of visible bremsstrahlung continuum profile because the bremsstrahlung continuum can be easily detected in high-density discharges of LHD.
Polyvinylidene fluoride dust detector response to particle impacts
Authors: James D. , Hoxie V. , Horanyi M.
Published: March 2010

Polyvinylidene fluoride (PVDF) dust detectors have flown on many space missions since their first use on the Vega 1 and 2 spacecraft. The fundamental operating principle of these detectors is the production of a charge upon impact by a hypervelocity dust particle. This measured signal, N, depends on the speed, v, and mass, m, of the particle. The relationship between N, v, and m was first empirically derived by Simpson and Tuzzolino. All of the PVDF dust instruments prior to the Student Dust Counter on the New Horizons mission use their formula for the calibration of the detectors. This paper provides additional dust impact calibration data, proposes a modification in the exponents for m and v, and investigates the relationship between detector temperature and detector signal.