bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomechanics and Functional Anatomy of Hollow Stemmed Sphenopsids: III. Equisetum hyemale
Authors: Speck T. , Speck O. , Emanns A. , Spatz H.‐Ch. 
Published: February 2014

Abstract:As in Equisetum giganteum, the hollow stem of Equisetum hyemale owes the mechanical stability of the internodes to an outer ring of strengthening tissue (hypodermal sterome) which provides stiffness and strength in the longitudinal direction. In contrast to hollow‐stemmed grasses, the hypodermal sterome consists of living cells. The compound inner tissue of the overwintering aerial stem of Equisetum hyemale includes a continuous inner and outer endodermis layer of vital thick‐walled cells that have slightly lignified Casparian thickenings. The two endodermis layers provide an inner tension and compression bracing which lend resistance to local buckling. The stress‐strain relation in longitudinal tension is biphasic with remarkably high critical strains especially in the upper parts of the stem. Scraping off part of the epidermis with the built‐in silicate does not change this behaviour, except in the initial steep part of the curve where the Young's modulus is reduced by 20%. No contribution of the endodermis and the parenchyma could be detected in tension tests of longitudinally‐oriented strips. Relaxation experiments reveal viscoelastic behaviour. As with the biphasic stress‐strain relation and the critical strains, the viscoelastic properties have largely to be ascribed to the hypodermal sterome.
Isozymes, Speciation and Evolution in the Polyploid Complex Cochlearia L. (Brassicaceae)
Authors: Koch M. , Huthmann Marion , Hurka H. 
Published: February 2014

Abstract:Within the genus Cochlearia L. sect. Cochlearia three isozyme systems (aspartate aminotransferase, leucine aminopeptidase and phosphoglucomutase) have been analysed at the populational level for eleven species with different ploidy levels. Nine loci complexes were resolved with a total of 33 alleles from 89 populations.In general, polyploids displayed higher numbers of alleles per species and per population. A notable exception is diploid C. pyrenaica with as many alleles as some polyploids. Data support: (1) the origin of tetraploid C. officinalis from C. pyrenaica s.l., particularly from C. aestuaria; (2) the allopolyploid origin of octoploid C. anglica from C. officinalis; (3) the allopolyploid origin of hexaploid inland taxa C. polonica, C. tatrae and C. bavarica via hybridization between C. pyrenaica and C. officinalis; (4) a putative allopolyploid origin of hexaploid coastal species C. danica by hybridization between C. pyrenaica s.l. and C. officinalis accompanied by a shift in chromosome complement. A scenario summarizing our present understanding of the evolution within Cochlearia sect. Cochlearia is presented.
Spore Liberation and Dispersal in Smut Fungi*
Authors: Piepenbring M. , Hagedorn G. , Oberwinkler F. 
Published: February 2014

Abstract:Teliospores are the most important diaspores of smut fungi, albeit not the only ones. The role of basidla, basidiospores, secondary spores, yeast cells, and infected parts of the host for dispersal has often been neglected. Many smut species have soral structures like galls, peridia, and elaters, which cause teliospores to be liberated over prolonged periods. This increases the chance that at least some spores are released under favourable wet climatic conditions and while host plants are susceptible.In this review, the diversity of dispersal units as well as vectors of smut fungi are presented. The importance of timing of diaspore liberation, flexibility in dispersal strategies, and the genetic and evolutionary implications of dispersal strategies of smut fungi are discussed.The general considerations are complemented by examples based on original field and laboratory observations: peridia of Farysia corniculata and certain species of Sporisorium expose the spore mass by hygroscopic movement under wet conditions (hygrochasy) favourable for teliospore germination and infection of a host plant. Basidia with firmly attached basidiospores liberated from spore balls of Doassansiopsis deformans, branched basidiospores of Rhamphospora nymphaeae, needle‐shaped basidiospores of species of Entyloma, folded basidiospores of Mycosyrinx cissi, and stellate groups of yeast cells of Trichocintractia utriculicola show enlarged surfaces, which are advantageous for dispersal in water. Galls filled with spore balls of Doassansiopsis limnocharidis and witches' brooms formed by spikelets infected by Cintractia standleyana separate from the host and fall into water where they are dispersed.
Evidence for the Uptake of Large Anions through Stomatal Pores
Authors: Eichert T. , Goldbach H. E. , Burkhardt J. 
Published: February 2014

Abstract:Experiments were conducted with leek (Allium porrum L.) leaves to investigate whether aqueous solutions are able to penetrate stomata. Epidermal strips were used for the determination of transport rates. Stomata were opened by fusicoccin or closed by darkness or abscisic acid. A droplet containing the anionic fluorescent dye, uranine, was placed on the physiologically outer side of the epidermis and allowed to dry. With open stomata 30 times more uranine penetrated through the epidermal strips than with closed stomata (comparison of medians). In another experiment droplets of uranine solution were placed on leaf segments and epidermal strips were removed after drying of the droplets. Penetration of uranine through stomata was detectable under the microscope both with epidermal strips from the transport experiments and with strips obtained after application on leaf segments. As maximum uptake rates occurred during the drying process, it is concluded that penetration took place via water films. These results show that the physical restrictions preventing stomatal penetration of static droplets are not decisive for drying droplets and that stomatal uptake of dissolved ionic substances occurs under natural conditions, i.e. without surfactants or applied pressure.
Modes of Self‐Pollination and Absence of Cryptic Self‐Incompatibility in Drosophyllum lusitanicum (Droseraceae)
Authors: Ortega‐Olivencia A. , Paredes J. A. López , Rodríguez‐Riaño T. , Devesa J. A. 
Published: February 2014

Abstract:We show experimentally that several types of selfing occur simultaneously in Drosophyllum lusitanicum: prior, competitive, insect‐facilitated, delayed and geitonogamous. In addition, we report evidence of cleistogamy in the flower bud. All types of selfing were successful in producing fruits and seeds; however, geitonogamy did not occur uniformly throughout the flowering period in this species. We also report the absence of cryptic self‐incompatibility: the germination rate and pollen tube growth rate of cross pollen were no greater than those of self pollen when both types were placed on stigmas of the same flower (mixed pollination). There was a tendency for self pollen to be more vigorous than cross pollen but it just failed to reach significance.
Climate, Colonisation and Celibacy: Population Structure in Central European Trichomanes speciosum (Pteridophyta)
Authors: Rumsey F. J. , Vogel J. C. , Russell S. J. , Barrett J. A. , Gibby Mary 
Published: February 2014

Abstract:The Killarney fern Trichomanes speciosum Willd. (Hymenophyllaceae) is unique in possessing both extensive sexual (sporophyte and gametophyte generations present) and asexual (gametophyte only) ranges. It was first discovered in central Europe in 1993 and is represented in this area only by its perennial, vegetatively propagating gametophyte generation. Genetic variation has been investigated at 35 sites. Allozyme diversity is partitioned primarily between, not within, sites. Although genetic variation exists at a fine scale (lt 5 m) within some populations, the results suggest that clones were not intimately associated in these cases. The majority of sites support unique multilocus phenotypes. Where phenotypes were present at more than one site they tended to recur at the next closest site. However, similar phenotypes link eastern and western Pfälzerwald sites up to c. 70 km apart. This pattern of diversity suggests that colonisation was not solely of a “stepping stone” or “leading edge” type. We suggest that during a climatically favourable period, probably the Atlantic hypsithermal, there may have been an explosive colonisation by long‐distance dispersal from refugial areas. This was followed by a short period during which sporophyte production, sexual reproduction and local spread were possible. With climatic change, reduction in the available habitat and the loss of the sporophyte generation, different individual genets became fixed within small, favourable, but scattered, sites. The possibility that some central European sites north of the Alps acted as periglacial refugia cannot be discounted, but would appear less likely than (re‐) colonisation from the Atlantic fringe.
The Breeding System of Oxalis squamata, a Tristylous South American Species
Authors: Marco Diana E. , Arroyo Mary T. Kalin 
Published: February 2014

Abstract:Oxalis squamata is a perennial endemic herb of the Chilean‐Argentine Andes previously reported as a distylous species. In this paper, analysis of floral morphology, incompatibility relations and population structure show that O. squamata possesses morphological and functional tristyly. The three floral morphs differ in calyx and corolla length, style and stamen length, pollen grain size and stylar pubescence. Results of hand pollinations showed the presence of a strong incompatibility system. Legitimate pollinations with the L and M morphs as seed parents produced approximately equal numbers of seeds per pollination. The S morph produced less than half the number of seeds per legitimate pollination compared to the other two morphs. Intra‐ and intermorph illegitimate pollinations produce almost no seeds. Morph representation in the population was isoplethic. Fruit and seed production did not differ significantly for the three morphs in the population. Comparison of experimental and natural production of fruits and seeds suggests that seed set in the natural population may be pollen‐limited for the L and M morphs.
Ask a busy person: attentional myopia and helping
Authors: Wallaert Matthew , Ward Andrew , Mann Traci 
Published: February 2014

AbstractAccording to an oft‐quoted piece of folk wisdom, if one wants something accomplished, the best person to ask is a busy person. We tested a version of this proposition in two studies. Study 1 exposed participants to a helping request in which cues promoting the relevant behavior were made more salient than those inhibiting it. Study 2 featured a request in which inhibiting cues were made more salient than cues promoting the behavior. In both studies, participants who were “busied” by high cognitive load showed more influence of the dominant behavioral pressure than did participants under minimal load. The results suggest that busy people can respond more to a helping appeal, but only when cues facilitating helping are more salient than those discouraging it.
Relation of the Unipolar Low‐Voltage Penumbra Surrounding the Endocardial Low‐Voltage Scar to Ventricular Tachycardia Circuit Sites and Ablation Outcomes in Ischemic Cardiomyopathy
Authors: CHOPRA NAGESH , TOKUDA MICHIFUMI , NG JUSTIN , REICHLIN TOBIAS , NOF EYAL , JOHN ROY M. , TEDROW USHA B. , STEVENSON WILLIAM G. 
Published: February 2014

VT Recurrence as Related to Scar Ablation SitesIntroductionMagnetic resonance (MR)‐imaging has shown that infarct scars causing ventricular tachycardia (VT) can extend deep to and beyond bipolar low‐voltage areas (LVAs) and may be a source of ablation failure. We hypothesized that the size of the unipolar LVA “penumbra” beyond the overlying bipolar scar may predict outcome of endocardial VT ablation.MethodsTwenty consecutive patients with ischemic cardiomyopathy who underwent endocardial VT ablation were retrospectively reviewed. Bipolar (30–500 Hz) LVA defined as <1.5 mV and unipolar (0.5–500 Hz) LVA defined as <8.3 mV were reviewed on an electroanatomic mapping system. VT isthmus sites were identified from entrainment mapping, VT termination by ablation, or pace‐mapping with abolition of VT inducibility by ablation.ResultsAll bipolar LVAs (70.5 ± 20 cm2) had unipolar LVAs that surrounded the bipolar LVA (147 ± 47 cm2). Only 58% of the induced VTs could be mapped and ablated. During a 3‐month follow‐up 8/20 patients had VT recurrence. The size of the LVA penumbra was not different for those with (88 ± 47 cm2) versus without (69 ± 35 cm2) recurrences. However, all (8/8) of the group that recurred had isthmus/exits in the bipolar LVA border compared to only 3/12 that did not recur (100% vs. 25%; P < 0.05). Furthermore, 5/8 patients who recurred harbored VT isthmuses in the unipolar LVA penumbra than 1/12 who did not recur (63% vs. 8%; P = 0.01).ConclusionIn ischemic cardiomyoapthy, unipolar LVA penumbra of varying size surrounds endocardial bipolar LVA, indicating intramural/epicardial scar. Although the size of this area did not predict early recurrence after endocardial ablation, frequent recurrences after VT ablation at scar periphery suggests deeper substrate toward the infarct border.
Oxidation‐ and CaMKII‐Mediated Sarcoplasmic Reticulum Ca2+ Leak Triggers Atrial Fibrillation in Aging
Authors: GUO XIAOXIAO , YUAN SU , LIU ZHENYU , FANG QUAN 
Published: February 2014

Ca2+ Leak Triggers Atrial Fibrillation in AgingBackgroundAdvanced age is a well‐recognized predisposition to atrial fibrillation (AF). However, the cellular electrophysiological changes that underlie the heightened susceptibility to AF in aged individuals remain poorly understood. Sarcoplasmic reticulum (SR) Ca2+ leak that results from posttranslational modification of type 2 ryanodine receptor channels (RyR2) has been implicated in arrhythmogenesis. We hypothesize that aging alters atrial myocytes Ca2+ homeostasis and RyR2 function, which create a substrate for AF initiation.Methods and ResultsWe examined the susceptibility to AF in aged (24 months) and young adult (4–5 months) mice using an intraesophageal atrial electrical stimulation protocol. Aged mice showed significant higher AF induction rate (43.3%, n = 30) than young adults (8.8%, n = 34, P < 0.01). In accordance with these in vivo findings, significantly increased diastolic SR Ca2+ leak and arrhythmogenic Ca2+ activities with reduced SR Ca2+ content were observed in aged atrial myocytes. Western blot showed RyR2 oxidation and phosphorylation at Ser2814 (Ca2+/calmodulin‐dependent protein kinase II [CaMKII] site), but not phosphorylation at Ser2808 (protein kinase A [PKA] and CaMKII site), were increased in aged atrial myocytes. The selective CaMKII inhibitor (KN‐93), as well as the antioxidant reagent (DTT) reversed the diastolic Ca2+ leak and the frequency of spontaneous Ca2+ transients in aged atrial myocytes, whereas PKA inhibition with H‐89 was ineffective.ConclusionsAging increases both the oxidation and CaMKII‐phosphorylation of RyR2, which result in diastolic SR Ca2+ leak and facilitate AF initiation. These results contribute to the electrophysiological remodeling of aged atria and suggest a therapeutic strategy for AF treatment in aging.
Effect of Induced LV Dyssynchrony by Right Ventricular Apical Pacing on All‐Cause Mortality and Heart Failure Hospitalization Rates at Long‐Term Follow‐Up
Authors: AUGER DOMINIQUE , HOKE ULAS , MARSAN NINA AJMONE , TOPS LAURENS F. , LEONG DARRYL P. , BERTINI MATTEO , SCHALIJ MARTIN J. , BAX JEROEN J. , DELGADO VICTORIA 
Published: February 2014

Dyssynchrony and Right Ventricular Apical PacingBackgroundRight ventricular apical (RVA) pacing may induce left ventricular (LV) dyssynchrony. The long‐term prognostic implications of induction of LV dyssynchrony were retrospectively evaluated in a cohort of patients who underwent RVA pacing.MethodsA total of 169 patients (62 ± 13 years, 69% male) with high RVA pacing burden were included. Echocardiographic evaluation of LV volumes, ejection fraction, and dyssynchrony were performed before and after device implantation. LV dyssynchrony was assessed by 2‐dimensional radial strain speckle tracking echocardiography. Based on the median LV dyssynchrony value after RVA pacing, the patient population was dichotomized (induced and noninduced LV dyssynchrony groups) and was followed up for the occurrence of all‐cause mortality and heart failure (HF) hospitalization.ResultsBaseline mean LV ejection fraction was 51 ± 11%. Median LV dyssynchrony value was 40 ms (12–85 ms) before RVA pacing and increased to 91 ms (81–138 ms) after a median of 13 months (3–26 months) after RVA pacing. Median follow‐up duration was 70 months (interquartile range 42–96 months). Patients with induced LV dyssynchrony, defined as LV dyssynchrony value superior to the median at follow‐up (≥91 ms), showed higher mortality rates (5% and 27% vs. 1% and 3% at 3 and 5 years follow‐up; log‐rank P = 0.003) and HF hospitalization rates (18% and 24% vs. 3% and 4% at 3 and 5 years follow‐up; log‐rank P < 0.001) than patients with LV dyssynchrony <91 ms after RVA pacing. A multivariate model was developed to identify independent associates of a combined endpoint of all‐cause mortality or HF hospitalization. Induction of LV dyssynchrony was independently associated with increased risk of combined endpoint (HR [95% CI]: 3.369 [1.732–6.553], P < 0.001).ConclusionInduction of LV dyssynchrony by RVA pacing is associated with worse long‐term mortality and increased HF hospitalization rates.
BMI1 reprogrammes histone acetylation and enhances c‐fos pathway via directly binding to Zmym3 in malignant myeloid progression
Authors: Shen Hongjie , Chen Zixing , Ding Xin , Qi Xiaofei , Cen Jiannong , Wang Yuanyuan , Yao Li , Chen Yan 
Published: February 2014

AbstractThe polycomb group BMI1 is proved to be crucial in malignant myeloid progression. However, the underlying mechanism of the action of BMI1 in myeloid malignant progression was not well characterized. In this study, we found that the patients of both myelodysplastic syndromes and chronic myeloid leukaemia with BMI1 overexpression had a higher risk in malignant myeloid progression. In vitro gene transfection studies showed that BMI1 inhibited cell myeloid and erythroid differentiation induced by 12‐O‐tetradecanoyl phorbol‐13‐acetate (TPA) and histone deacetylase inhibitor sodium butyrate respectively. BMI1 also resisted apoptosis induced by arsenic trioxide. Moreover, the transcript levels of Runx1 and Pten were down‐regulated in Bmi1‐transfected cells in company with histone deacetylation modification. By using chromatin immunoprecipitation (ChIP) collaborated with secondary generation sequencing and verified by ChIP‐PCR, we found that BMI1 directly bound to the promoter region of Zmym3, which encodes a component of histone deacetylase‐containing complexes. In addition, as one of the downstream target genes of this complex, c‐fos was activated with increasing histone acetylation when ZMYM3 was suppressed in the Bmi1‐transfected cells. These results suggested that BMI1 may reprogramme the histone acetylation profile in multiple genes through either indirect or direct binding effects which probably contributes to the malignant progression of myeloid progenitor cells.
Protective role of 5‐azacytidine on myocardial infarction is associated with modulation of macrophage phenotype and inhibition of fibrosis
Authors: Kim Yong Sook , Kang Wan Seok , Kwon Jin Sook , Hong Moon Hwa , Jeong Hye‐yun , Jeong Hae Chang , Jeong Myung Ho , Ahn Youngkeun 
Published: February 2014

AbstractWe examined whether a shift in macrophage phenotype could be therapeutic for myocardial infarction (MI). The mouse macrophage cell line RAW264.7 was stimulated with peptidoglycan (PGN), with or without 5‐azacytidine (5AZ) treatment. MI was induced by ligation of the left anterior descending coronary artery in rats, and the rats were divided into two groups; a saline‐injection group and a 5AZ‐injection group (2.5 mg/kg/day, intraperitoneal injection). LV function was evaluated and immunohistochemical analyses were performed 2 weeks after MI. Cardiac fibrosis was induced by angiotensin II (AngII) infusion with or without 5AZ (5 mg/kg/day) in mice. Nitric oxide was produced by PGN, which was reduced by 77.87% after 5AZ treatment. Both induction of inducible nitric oxide synthase (iNOS) and iNOS promoter activity by PGN were inhibited by 5AZ. Ejection fraction (59.00 ± 8.03% versus 42.52 ± 2.58%), contractility (LV dP/dt‐max, 8299.76 ± 411.56 mmHg versus 6610.36 ± 282.37 mmHg) and relaxation indices (LV dP/dt‐min, −4661.37 ± 210.73 mmHg versus −4219.50 ± 162.98 mmHg) were improved after 5AZ administration. Cardiac fibrosis in the MI+5AZ was 8.14 ± 1.00%, compared with 14.93 ± 2.98% in the MI group (P < 0.05). Arginase‐1(+)CD68(+) macrophages with anti‐inflammatory phenotype were predominant in the infarct border zone of the MI+5AZ group, in comparison with the MI group. AngII‐induced cardiac fibrosis was also attenuated after 5AZ administration. In cardiac fibroblasts, pro‐fibrotic mediators and cell proliferation were increased by AngII, and these increases were attenuated after 5AZ treatment. 5AZ exerts its cardiac protective role through modulation of macrophages and cardiac fibroblasts.
Influence of Degree of Gelatinization on Expansion of Extruded, Starch‐Based Pellets during Microwave Vacuum Processing
Authors: Kraus Stefan , Enke Nathanael , Gaukel Volker , Schuchmann Heike P. 
Published: February 2014

AbstractThe influence of the degree of gelatinization (DG) on microwave‐induced expansion of starch‐based, extruded pellets under vacuum was investigated. Expansion of extruded pellets with initial DG between 43.6 and 72.9% was investigated in a microwave vacuum drying system. With increasing DG, volume expansion showed a linear increase. The number of pores significantly increased at DG above 64.2%. A larger amount of water available might be the reason for the increased nucleation at large DG. The pore sizes decrease with increasing number of pores. If a larger number of bubbles is nucleated, a fewer amount of water can diffuse into every single bubble possibly resulting in lower water vapor pressure. No relationship between rheological and expansion properties of the matrix could be observed. We therefore assume that nucleation has the strongest effect on pore size distribution.Practical ApplicationsIn contrast to direct‐expanded extruded snacks, third‐generation snacks are generally produced by predrying nonexpanded, extruded pellets, followed by expansion to achieve a crispy and porous texture. By this procedure, extrusion can be performed at high moisture contents, moderate temperatures and moderate shearing conditions. This way, thermal‐ and mechanical‐sensitive ingredients can be preserved. A distinctive feature of the process investigated in this study is that the expansion is achieved by microwave vacuum processing, which allows an indirect expansion without the time‐ and energy‐consuming predrying process. This study shows that total volume and inner structure of the expanded pellets is influenced by the degree of gelatinization. With these information, producers can turn structure‐related properties such as appearance, crispiness and crunchiness to targeted values.