bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and functional analysis of an asymmetric bidirectional promoter in Arabidopsis thaliana
Authors: Liu Shi‐Juan , Yue Qiu‐Juan , Zhang Wei
Published: November 2014

Bidirectional promoters are relatively abundant in eukaryotic genomes, suggesting that they have an important biological significance. As yet, few of these promoters have been characterized in detail. Here, using a promoter::GUS transgene approach has revealed that the intergenic region of Arabidopsis thaliana divergent genes At1g71850 and At1g71860 is an asymmetric bidirectional promoter, which exhibits an orientation‐dependent expression profile. The strength of the forward promoter was greater than that of the reverse promoter, and their tissue specificities were not identical. Deletion analyses revealed that this bidirectional promoter could be divided into three functional regions. The basal level and tissue specificity of the promoter in the reverse orientation were regulated positively by region II and negatively by region III, whereas promoter activity in the forward orientation was regulated negatively by region II and positively by region I. Thus the 52‐bp stretch of region II had a dual function, enhancing expression in the reverse orientation and suppressing it in the forward orientation. These results demonstrated that the activity of the At1g71850‐At1g71860 bidirectional promoter was modulated by complex interactions between both positive and negative cis‐acting elements. These findings will enhance our understanding of the regulatory mechanisms of plant bidirectional promoters.
Hypoxic regulation of plasminogen activator inhibitor‐1 expression in human buccal mucosa fibroblasts stimulated with arecoline
Authors: Tsai Chung‐Hung , Lee Shiuan‐Shinn , Chang Yu‐Chao
Published: November 2014

Background

Oral submucous fibrosis (OSF) is regarded as a pre‐cancerous condition with fibrosis in oral subepithelial connective tissue. Hypoxia‐inducible factor (HIF)‐1α regulates a wide variety of profibrogenic genes, which are closely associated with tissue fibrosis. The aim of this study was to compare HIF‐1α expression in normal buccal mucosa tissues and OSF specimens and further explore the potential mechanisms that may lead to the induction of HIF‐1α expression.

Method

Twenty‐five OSF specimens and six normal buccal mucosa were examined by immunohistochemistry. The expression of HIF‐1α from fibroblasts cultured from OSF and normal buccal mucosa was measured by Western blot. Arecoline, a major areca nut alkaloid, was challenged to normal buccal mucosa fibroblasts (BMFs) to elucidate whether HIF‐1α expression could affect by arecoline. In addition, the effects of arecoline on plasminogen activator inhibitor (PAI)‐1 expression were evaluated in environmental hypoxia.

Results

HIF‐1α expression was significantly higher in OSF specimens and expressed mainly by fibroblasts, epithelial cells, and inflammatory cells. Fibroblasts derived from OSF were found to exhibit higher HIF‐1α protein expression than BMFs (P < 0.05). Arecoline was found to upregulate HIF‐1α protein in a dose‐dependent manner (P < 0.05). Hypoxia increased arecoline‐induced PAI‐1 protein expression than normoxic conditions (P < 0.05).

Conclusion

These results suggest that HIF‐1α expression is significantly upregulated in OSF tissues from areca quid chewers, implying a potential role as a biomarker for local tissue hypoxia. The activation of HIF‐1α may promote fibrogenesis by an increase of PAI‐1 expression and a subsequent elevation of extracellular matrix production in oral submucosa leading to fibrosis.
ZEB1 as an indicator of tumor recurrence for areca quid chewing‐associated oral squamous cell carcinomas
Authors: Ho Cho Ming , Hu Fang‐Wei , Lee Shiuan‐Shinn , Shieh Tzong‐Ming , Yu Chuan‐Hang , Lin Shih‐Shen , Yu Cheng‐Chia
Published: November 2014

Background

Oral squamous cell carcinoma (OSCC) is the sixth most prevalent malignancy worldwide and the third most common cancer in developing nation. Most OSCC patients relapse within months after receiving treatment. Therefore, searching the biomarkers of recurrence is urgently required to improve OSCC patient survival.

Methods

We set out to explore whether expression of ZEB1 could be triggered in oral epithelial cells (SG and FaDu) by arecoline in vitro. Control and ZEB1‐knockdown arecoline‐stimulated SG and FaDu were subjected to migration/invasiveness/anchorage‐independent growth assay. Primary and recurrent OSCC tissues from areca quid chewers were analyzed using real‐time RT‐PCR analysis for ZEB1 expression.

Results

Arecoline led to dose‐dependent elevation of ZEB1 expression in SG and FaDu cells. Downregulation of ZEB1 by lentiviral infection significantly reversed arecoline‐induced oncogenicity including migration ability, cell invasiveness, and anchorage‐independent growth in SG and FaDu cells. Clinically, the level of ZEB1 expression was higher in recurrent OSCC tumor samples but lower in primary lesions.

Conclusions

Targeting ZEB1 might offer a new strategy for the treatment of OSCC patients. ZEB1 can serve as a progression and relapse marker in OSCC patients.
Melatonin feedback on clock genes: a theory involving the proteasome
Authors: Vriend Jerry , Reiter Russel J.
Published: November 2014

The expression of ‘clock’ genes occurs in all tissues, but especially in the suprachiasmatic nuclei (SCN) of the hypothalamus, groups of neurons in the brain that regulate circadian rhythms. Melatonin is secreted by the pineal gland in a circadian manner as influenced by theSCN. There is also considerable evidence that melatonin, in turn, acts on theSCNdirectly influencing the circadian ‘clock’ mechanisms. The most direct route by which melatonin could reach theSCNwould be via the cerebrospinal fluid of the third ventricle. Melatonin could also reach the pars tuberalis (PT) of the pituitary, another melatonin‐sensitive tissue, via this route. The major ‘clock’ genes include the period genes,Per1andPer2, the cryptochrome genes,Cry1andCry2, theclock(circadian locomotor output cycles kaput) gene, and theBmal1(aryl hydrocarbon receptor nuclear translocator‐like) gene. Clock and Bmal1 heterodimers act on E‐box components of the promoters of the Per and Cry genes to stimulate transcription. A negative feedback loop between the cryptochrome proteins and the nucleus allows the Cry and Per proteins to regulate their own transcription. A cycle of ubiquitination and deubiquitination controls the levels ofCRYprotein degraded by the proteasome and, hence, the amount of protein available for feedback. Thus, it provides a post‐translational component to the circadian clock mechanism.BMAL1 also stimulates transcription ofREV‐ERBαand, in turn, is also partially regulated by negative feedback byREV‐ERBα. In the ‘black widow’ model of transcription, proteasomes destroy transcription factors that are needed only for a particular period of time. In the model proposed herein, the interaction of melatonin and the proteasome is required to adjust theSCNclock to changes in the environmental photoperiod. In particular, we predict that melatonin inhibition of the proteasome interferes with negative feedback loops (CRY/PERandREV‐ERBα) on Bmal1 transcription genes in both theSCNandPT. Melatonin inhibition of the proteasome would also tend to stabilizeBMAL1 protein itself in theSCN, particularly at night when melatonin is naturally elevated. Melatonin inhibition of the proteasome could account for the effects of melatonin on circadian rhythms associated with molecular timing genes. The interaction of melatonin with the proteasome in the hypothalamus also provides a model for explaining the dramatic ‘time of day’ effect of melatonin injections on reproductive status of seasonal breeders. Finally, the model predicts that a proteasome inhibitor such as bortezomib would modify circadian rhythms in a manner similar to melatonin.
Cardioprotective effects of melatonin against myocardial injuries induced by chronic intermittent hypoxia in rats
Authors: Yeung Hang‐Mee , Hung Ming‐Wai , Lau Chi‐Fai , Fung Man‐Lung
Published: November 2014

Obstructive sleep apnea (OSA) associated with chronic intermittent hypoxia (CIH) increases the morbidity and mortality of ischemic heart disease in patients. Yet, there is a paucity of preventive measures targeting the pathogenesis of CIH‐induced myocardial injury. We examined the cardioprotective effect of melatonin against the inflammation, fibrosis and the deteriorated sarcoplasmic reticulum (SR) Ca2+ homeostasis, and ischemia/reperfusion (I/R)‐induced injury exacerbated by CIH. Adult male Sprague Dawley rats that had received a daily injection of melatonin (10 mg/kg) or vehicle were exposed to CIH treatment mimicking a severe OSA condition for 4 wk. Systolic pressure, heart weights, and malondialdehyde were significantly increased in hypoxic rats but not in the melatonin‐treated group, when compared with the normoxic control. Levels of the expression of inflammatory cytokines (TNF‐α, IL‐6, and COX‐2) and fibrotic markers (PC1 and TGF‐β) were significantly elevated in the hypoxic group but were normalized by melatonin. Additionally, infarct size of isolated hearts with regional I/R was substantial in the hypoxic group treated with vehicle but not in the melatonin‐treated group. Moreover, melatonin treatment mitigated the SR‐Ca2+ homeostasis in the cardiomyocyte during I/R with (i) Ca2+ overloading, (ii) decreased SR‐Ca2+ content, (iii) lowered expression and activity of Ca2+‐handling proteins (SERCA2a and NCX1),and (iv) decreased expressions of CAMKII and phosphorylated eNOSser1177. Furthermore, melatonin ameliorated the level of expression of antioxidant enzymes (CAT and MnSOD) and NADPH oxidase (p22 and NOX2). Results support a prophylactic usage of melatonin in OSA patients, which protects against CIH‐induced myocardial inflammation and fibrosis with impaired SR‐Ca2+ handling and exacerbated I/R injury.
The Relationship of Individual Capabilities and Environmental Support with Different Facets of Designers' Innovative Behavior
Authors: Birdi Kamal , Leach Desmond , Magadley Wissam
Published: November 2014

Theoretical perspectives on employee creativity have tended to focus on an individual's capability to generate original and potentially useful ideas, whereas definitions of innovation also include the process of putting those new ideas into practice. This field study therefore set out to test how theoretically distinct types of individual knowledge and skills are related to different aspects of employees' innovative behavior in terms of both their new idea generation and idea implementation. Using a sample of design engineers (n = 169) in a multinational engineering company, measures were taken of different aspects of innovative work behavior (patent submission, real‐time idea submission, idea implementation) and a range of individual capabilities (creativity‐relevant skills, job expertise, operational skills, contextual knowledge, and motivation) and environmental features (job control, departmental support for innovation). Analyses showed that creativity‐relevant skills were positively related to indices of idea generation but not to idea implementation. Instead, employees' job expertise, operational skills, and motivation to innovate demonstrated a stronger role in idea implementation. In terms of environmental factors, job control showed no positive relationship with innovative work behavior while departmental support for innovation was related to employees' idea generation but not idea implementation. The theoretical perspective that correlates of idea generation differ in certain aspects to those for idea implementation are confirmed by the study. Practical implications for organizations wishing to improve their innovativeness are discussed in terms of tailored training, development, motivational, and environmental interventions designed to improve the capabilities of individuals to engage in all parts of the innovation process.
Receipt of Regular Primary Care and Early Cancer Detection in Appalachia
Authors: Camacho Fabian , Hwang Wenke , Kern Teresa , Anderson Roger T.
Published: November 2014

Purpose

The objective was to examine the impact of regular primary care encounters (PCE) on early breast cancer detection in an Appalachian sample of Medicare beneficiaries diagnosed 2006‐2008. Determinants of PCE were investigated and a mediation analysis was conducted where PCE was a mediator to cancer stage.

Methods

A total of 3,589 cases were identified from Appalachian areas in Pennsylvania, Kentucky, Ohio, and North Carolina, and health care services were examined 2 months to 2 years prior to diagnosis. A regular care PCE variable was constructed with 4 ordinal levels: none, any, “annual,” and “semi‐annual.” Association of PCE with stage, mortality and covariables was conducted using ordinal logistic regressions and Cox Proportional Hazards survival models.

Results

Sixty‐eight percent of the cases had semi‐annual PCE. Regular PCE was strongly associated with late‐stage cancer rates (39%‐13% by increasing PCE level,P< .0001) and 5‐year all‐cause mortality (42%‐24%,P< .0001). Subgroup analysis revealed variations by hypertension and urban status, with nonhypertensives with no PCE being at particularly increased risk. Significant determinants of PCE included age, rural/urban status, comorbidity, dual Medicaid insurance, Appalachian region economic classification, state, select comorbidities, hypertension, and minimum distance to provider. Mediation analysis results were consistent with lower number of comorbidities leading to increased late cancer detection due to patients having a decreased PCE.

Conclusion

PCE is an important determinant of cancer detection, with a dose‐response relationship. Variations exist by geography and hypertension. Comorbidity may influence both PCE and late‐stage rates with partial mediation through PCE.
The Influence of Personality and Coping on Female Sexual Function: A Population Survey
Authors: Crisp Catrina , Vaccaro Christine , Fellner Angela , Kleeman Steven , Pauls Rachel
Published: November 2014

Introduction

Female sexual dysfunction (FSD) is a common disorder with limited data investigating relationships with psychological influences, such as personality traits and coping mechanisms.

Aim

To investigate the relationship and impact of personality traits and coping strategies on female sexual function.

Methods

A web-based survey was distributed to a sample of women representative of the area’s demographic distribution.

Main Outcome Measures

Participants completed the Female Sexual Function Index (FSFI), the Ten Item Personality Index (TIPI), and the Brief COPE.

Results

Five hundred twenty-six females responded. The mean total FSFI score was 24.56 (SD 6.77) with lowest scores in the desire domain. Personality scores were similar to published normative values. Subjects displaying stronger tendencies for introversion (r = 0.246, P < 0.001), not being open to new experiences (r = 0.159, P = 0.008), and emotional instability (r = 0.244, P < 0.001) were found to have significantly worse sexual function. Conscientiousness was significantly associated with better desire, orgasm, satisfaction, and total FSFI score (P = 0.029, P = 0.002, P = 0.005, P = 0.003). Moreover, the utilization of negative coping strategies such as self-blame, self-distraction, and behavioral disengagement, significantly correlated with poor sexual function (r = −0.298, P < 0.001, r = −0.360, P < 0.001, r = −0.398, P < 0.001, respectively).

Conclusion

Personality and coping are linked to sexual function with introversion, not being open to new experiences, emotional instability, and the utilization of negative coping strategies being significantly associated with poor sexual function. Women presenting with sexual function complaints may need further evaluation of their personality and coping strategies in order to mitigate any negative impact of these tendencies.
More food or fewer predators? The benefits to birds of associating with aNeotropical primate varies with their foraging strategy
Authors: Barnett A. A. , Shaw P.
Published: November 2014

Although mixed‐species associations of birds or primates have been well studied, primate–bird associations have received comparatively little attention. Additionally, benefits accruing with such associations have rarely been quantified. Over 13 months, 17 insectivorous bird species were observed associating with golden‐backed uacaris. Detailed study of four found that feeding sally frequency significantly increased for sit‐and‐wait foragers (bronzy jacamar,Galbula leucogastra; black‐fronted nunbird,Monasa nigrifrons), when uacaris were present within 14.9 m, but not when within 15–30 m. Contemporaneously, no significant differences were observed in peck bout frequency for two uacari‐following bark‐ and leaf‐gleaning antbirds (black‐crested antshrike,Sakesphorus canadensis, black‐winged antbird,Hypocnemoides melanopogon) when uacaris were present or absent. Antbird/uacari approximation is attributed to significant reductions in the presence of small bird‐eating raptors when uacaris are present. Reasons for this are uncertain but may be because large raptors (e.g. harpy eagles) follow uacaris. So, while some bird species may gain foraging benefits from uacari presence, others may follow them because their proximity reduces predation risk. This appears foraging guild dependent. Except for work linking increased jacana peck rates with swamp‐visiting gorilla presence, this study is the first to quantify benefits to birds of following primates, and the first such Neotropical study.
Outbreeding avoidance as probable driver of mate choice in the Asiatic toad
Authors: Luo Z. , Hu M. , Hong M. , Li C. , Gu Q. , Gu Z. , Liao C. , Zhao M. , Wu Hua
Published: November 2014

Across taxa, females are routinely choosier than males in selecting mates. Several hypotheses have been advanced to explain genetic benefits behind female strategies. The inbreeding avoidance hypothesis suggests that females avoid mating with close relatives, thereby avoiding the matchup of deleterious recessive alleles. Outbreeding avoidance hypothesis suggests that females should not mate with too distantly related individuals so as to avoid the breakup of coadapted gene complexes. Although previous studies have suggested that selection should favor individuals that optimize the balance between inbreeding and outbreeding, detailed research is necessary to document the trade‐off between them and variability in mate choice across a gradient of inbreeding levels among populations. The good genes and the genetic compatibility hypotheses predict that females choose mates according to costly traits and genetic dissimilarity, respectively. Thus, to document inbreeding or outbreeding depressions and assess the contributions of mate choice based upon good genes versus genetic compatibility, we examined egg production, collected body length measurements and genotyped five microsatellite markers in six populations of Asiatic toad (Bufo gargarizans). Our results revealed that the incidence of inbreeding was higher than that expected under the assumption of random mating and relatedness between mated individuals increased when the average inbreeding level increased among populations. Our findings did not support the good genes or the genetic compatibility hypotheses. Although some other processes could have influences on mate choice of Asiatic toad and need to be tested, our results indicated that, in small and isolated toad populations, the limited availability and high cost of obtaining unrelated mates may promote outbreeding avoidance and adaptation to inbreeding to be the critical drives of female mate choice.
Effect of lanreotide on polycystic liver and kidneys in autosomal dominant polycystic kidney disease: an observational trial
Authors: Gevers Tom J.G. , Hol Jeroen C. , Monshouwer René , Dekker Helena M. , Wetzels Jack F.M. , Drenth Joost P.H.
Published: November 2014

Background & Aim

Several trials have demonstrated that somatostatin analogues decrease liver volume in mixed populations of patients with autosomal dominant polycystic kidney disease (ADPKD) and isolated polycystic liver disease. Chronic renal dysfunction in ADPKD may affect treatment efficacy of lanreotide and possibly enhances risk for adverse events. The aim of this open‐label clinical trial (RESOLVE trial) was to assess the efficacy of 6‐month lanreotide treatment, 120 mg, subcutaneously every 4 weeks in ADPKD patients with symptomatic polycystic liver disease.

Methods

Primary outcome was change in liver volume after 6 months; secondary outcomes were changes in kidney volume, estimated glomerular filtration rate (eGFR), symptom relief and health‐related quality of life (Euro‐Qol5D). We excluded patients with an eGFR <30 ml/min/1.73 m2. We used the Wilcoxon signed‐rank test or paired two‐sided t‐test to analyze within‐group differences.

Results

We included 43 ADPKD patients with polycystic liver disease (84% female, median age 50 years, mean eGFR 63 ml/min/1.73 m2). Median liver volume decreased from 4859 ml to 4595 ml (−3.1%; P < 0.001), and median kidney volume decreased from 1023 ml to 1012 ml (−1.7%; P = 0.006). eGFR declined 3.5% after the first injection, remained stable up to study end, to decline again after lanreotide withdrawal. Lanreotide significantly relieved post‐prandial fullness, shortness of breath and abdominal distension. Three participants had a suspected episode of hepatic or renal cyst infection during this study.

Conclusion

Lanreotide reduced polycystic liver and kidney volumes and decreases symptoms in ADPKD patients. Moreover, eGFR decreased acutely after starting lanreotide, stabilized thereafter and declined again after withdrawal. Trial registration number: Clinical trials.gov NCT01354405 (Registration: 13 May 2011).
Determinants governing ligand specificity of the Vibrio harveyi LuxN quorum‐sensing receptor
Authors: Ke Xiaobo , Miller Laura C. , Bassler Bonnie L.
Published: November 2014

Quorum sensing is a process of bacterial cell–cell communication that relies on the production, release and receptor‐driven detection of extracellular signal molecules called autoinducers. The quorum‐sensing bacterium Vibrio harveyi exclusively detects the autoinducer N‐((R)‐3‐hydroxybutanoyl)‐L‐homoserine lactone (3OH‐C4 HSL) via the two‐component receptor LuxN. To discover the principles underlying the exquisite selectivity LuxN has for its ligand, we identified LuxN mutants with altered specificity. LuxN uses three mechanisms to verify that the bound molecule is the correct ligand: in the context of the overall ligand‐binding site, His210 validates the C3 modification, Leu166 surveys the chain‐length and a strong steady‐state kinase bias imposes an energetic hurdle for inappropriate ligands to elicit signal transduction. Affinities for the LuxN kinase on and kinase off states underpin whether a ligand will act as an antagonist or an agonist. Mutations that bias LuxN to the agonized, kinase off, state are clustered in a region adjacent to the ligand‐binding site, suggesting that this region acts as the switch that triggers signal transduction. Together, our analyses illuminate how a histidine sensor kinase differentiates between ligands and exploits those differences to regulate its signaling activity.
Homoserine and quorum‐sensing acyl homoserine lactones as alternative sources of threonine: a potential role for homoserine kinase in insect‐stage Trypanosoma brucei
Authors: Ong Han B. , Lee Wai S. , Patterson Stephen , Wyllie Susan , Fairlamb Alan H.
Published: November 2014

De novo synthesis of threonine from aspartate occurs via the β‐aspartyl phosphate pathway in plants, bacteria and fungi. However, the Trypanosoma brucei genome encodes only the last two steps in this pathway: homoserine kinase (HSK) and threonine synthase. Here, we investigated the possible roles for this incomplete pathway through biochemical, genetic and nutritional studies. Purified recombinant TbHSK specifically phosphorylates L‐homoserine and displays kinetic properties similar to other HSKs. HSK null mutants generated in bloodstream forms displayed no growth phenotype in vitro or loss of virulence in vivo. However, following transformation into procyclic forms, homoserine, homoserine lactone and certain acyl homoserine lactones (AHLs) were found to substitute for threonine in growth media for wild‐type procyclics, but not HSK null mutants. The tsetse fly is considered to be an unlikely source of these nutrients as it feeds exclusively on mammalian blood. Bioinformatic studies predict that tsetse endosymbionts possess part (up to homoserine in Wigglesworthia glossinidia) or all of the β‐aspartyl phosphate pathway (Sodalis glossinidius). In addition S. glossinidius is known to produce 3‐oxohexanoylhomoserine lactone which also supports trypanosome growth. We propose that T. brucei has retained HSK and threonine synthase in order to salvage these nutrients when threonine availability is limiting.
Invasive pulmonary infection caused by Chrysosporium articulatum: the first case report
Authors: Suankratay Chusana , Dhissayakamol Onwalee , Uaprasert Noppacharn , Chindamporn Ariya
Published: November 2014

Chrysosporium species, saprobic soil fungi, comprise more than 60 species. There is some confusion regarding the taxonomy and nomenclature between Chrysosporium and Emmonsia since the causative agents of adiaspiromycosis, the development of big thick‐walled spores (adiaspores) in humans or animals, were previously thought to be Chrysosporium. Chrysosporium articulatum has never been reported to cause invasive infection in humans. We report herein the first case of invasive pulmonary infection caused by Chrysosporium articulatum in a 16‐year‐old man with acute T‐cell lymphoblastic leukaemia. He was successfully treated with voriconazole.
Esophageal acid stimulation alters insular cortex functional connectivity in gastroesophageal reflux disease
Authors: Siwiec R. M. , Babaei A. , Kern M. , Samuel E. A. , Li S. ‐J. , Shaker R.
Published: November 2014

Background

The insula plays a significant role in the interoceptive processing of visceral stimuli. We have previously shown that gastroesophageal reflux disease (GERD) patients have increased insular cortex activity during esophageal stimulation, suggesting a sensitized esophago‐cortical neuraxis. However, information regarding the functional connectivity (FC) of the insula during visceral stimulation is lacking. The primary aim of this study was to investigate the FC of insular subregions during esophageal acid stimulation.

Methods

Functional imaging data were obtained from 12 GERD patients and 14 healthy subjects during four steady state conditions: (i) presence of transnasal esophageal catheter (pre‐infusion); (ii) neutral solution; (iii) acid infusion; (iv) presence of transnasal esophageal catheter following infusions (post‐infusion). The insula was parcellated into six regions of interest. FC maps between each insular ROI and interoceptive regions were created. Differences in FC between GERD patients and healthy subjects were determined across the 4 study conditions.

Key Results

All GERD patients experienced heartburn during and after esophageal acidification. Significant differences between GERD patients and healthy subjects were seen in: (i) insula‐thalamic FC (neutral solution infusion, acid infusion, post‐infusion); (ii) insula‐amygdala FC (acid infusion, post‐infusion); (iii) insula‐hippocampus and insula‐cingulate FC (post‐infusion).

Conclusions & Inferences

Esophageal stimulation in GERD patients revealed significant insular cortex FC differences with regions involved in viscerosensation and interoception. The results of our study provide further evidence that the insula, located at the transition of afferent physiologic information to human feelings, is essential for both visceral homeostasis and the experience of heartburn in GERD patients.
Are mismatches the norm? Timing of flowering, fruiting, dispersal and germination and their fitness effects in Frangula alnus (Rhamnaceae)
Authors: Bolmgren Kjell , Eriksson Ove
Published: November 2014

The close morphological and temporal links between phases of plant growth and reproduction call for integrated studies incorporating several reproductive phases from flowering to recruitment, and associated plant‐animal interactions. Phenological strategies, as well as plastic phenological response to climate change, incorporate complex interactions between developmental constraints, pollination and seed dispersal. Relationships between reproductive phenology and components of fitness were studied for two years in the north‐temperate, self‐incompatible, insect‐pollinated, and bird‐dispersed shrub Frangula alnus (Rhamnaceae). Fruit set, dispersal, germination and juvenile survival, as well as seed mass and juvenile size were measured in relation to flowering, fruiting and germination time. The results suggest that effects of flowering and fruiting time prevailed in subsequent phases, to some extent as far as to the juvenile phase, but effects of timing were complex and had partly opposing effects on different fitness components. Early flowers had higher fruit‐set and experiments indicated that synchronous peak flowering increased fruit‐set, but later flowers had higher seed mass. Peak fruiting was not associated with peak dispersal. Late fruits derived from late flowers promoted dispersal. Juvenile recruitment was enhanced by increasing seed size. We conclude that the phenology of flowering and fruiting in F. alnus comprises several features, each with different and sometimes counteracting effects on fitness components. From a general perspective, this result implies that we should not expect to find finely tuned matches in timing specifically between flowering and pollinators, and fruiting and seed dispersing birds.
Priming of soil organic matter decomposition scales linearly with microbial biomass response to litter input in steppe vegetation
Authors: Xiao Chunwang , Guenet Bertrand , Zhou Yong , Su Jiaqi , Janssens Ivan A.
Published: November 2014

Fresh plant litter inputs accelerate soil organic matter (SOM) decomposition through a ubiquitous mechanism called priming. Insufficient priming has been suggested as a stabilization mechanism of SOM at depth, as well as the long‐term persistence of some highly degradable organic compounds in soils. Priming therefore plays a crucial, albeit unquantified and commonly neglected, role in the global carbon cycle. Because priming intensity is likely to be altered by global change‐induced changes in net primary productivity, it casts substantial uncertainty to future projections of the climate‐carbon cycle feedback. Using results from a large field litter manipulation experiment in Mongolian steppe, we here show that priming intensifies with increasing litter inputs, but at a decreasing efficiency: the stimulation per unit litter added declines with increasing litter inputs. This non‐linear behavior originates from two antagonistic responses to fresh litter inputs: a stimulation of microbial activity versus a shift in microbial community composition (more fungi) associated to substrate shift from SOM to litter. Despite all complexity, however, the priming effect on SOM decomposition scaled linearly with the response of microbial biomass across the entire range of plant litter addition (60–480 g C m−2), suggesting that priming could be modeled effectively as a function of the response of microbial biomass to litter inputs. Incorporating the priming mechanism in Earth System models will improve their estimates of the SOM‐climate feedback and appears to be best addressed by explicitly representing microbial biomass in the models.
Sexual size dimorphism in island plants: the niche variation hypothesis and insular size changes
Authors: Kavanagh Patrick H. , Burns Kevin C.
Published: November 2014

The niche variation hypothesis predicts insular populations exhibit increased sexual size dimorphism (SSD), to minimize intraspecific competition. Although many animal taxa conform to this prediction, insular patterns of SSD have yet to be investigated in plants. Here, we tested for differences in SSD of dioecious plants that colonised four island groups (Kermadec, Three Kings, Chatham and Auckland Islands) from New Zealand. Using herbarium collections, we quantified leaf and stem sizes of 263 individuals from 28 dioecious taxa. We developed a novel analytical technique to explore changes in the direction of SSD on islands. Lastly, we tested for evolutionary size changes of male and female plants on islands. The degree of SSD did not vary predictably between insular and mainland taxa, contrary to predictions of the niche variation hypothesis. Furthermore, the direction of SSD was not predictable on islands, while it was consistently female biased on the mainland. Our results suggest that selection favours increased size of both sexes on islands and that SSD is unpredictable for insular plants.
Determinants of size at metamorphosis in an endangered amphibian and their projected effects on population stability
Authors: Searcy Christopher A. , Snaas Helen , Shaffer H. Bradley
Published: November 2014

Roughly 80% of animal species have complex life cycles spanning a major habitat shift, and delayed life history effects play an important role in their population dynamics. Through their effect on size at metamorphosis, factors in the pre‐ metamorphic environment often have profound effects upon survival and fecundity in the post‐metamorphic environment. Here, we adopted a combined experimental and field observational approach to investigate the factors that determine size at metamorphosis in pond‐breeding amphibians, and to predict some of their downstream effects on population stability. We set up ecologically realistic mesocosm communities for the endangered California tiger salamander Ambystoma californiense to test the effects of larval density, prey density and hydroperiod on mean size at metamorphosis. We found significant effects for all three factors, with mean size at metamorphosis negatively correlated with larval density and positively correlated with prey density and hydroperiod. We also used six years of field survey data to identify the most informative model explaining mean size at metamorphosis and thus validate our mesocosm results. The optimal three‐term model identified terms that were roughly analogous to each of the mesocosm treatments and with similar effect sizes, providing strong field confirmation of our experimental results. The field data also provide correlations between each factor and the number of metamorphs recruited to the population, allowing us to predict the effect of each factor on population stability. Finally, we show that these populations of the endangered A. californiense are strongly resource limited, which has important implications for their management and recovery as an endangered taxon.
Climate‐resilient agroforestry: physiological responses to climate change and engineering of crassulacean acid metabolism (CAM) as a mitigation strategy
Authors: BORLAND ANNE M. , WULLSCHLEGER STAN D. , WESTON DAVID J. , HARTWELL JAMES , TUSKAN GERALD A. , YANG XIAOHAN , CUSHMAN JOHN C.
Published: November 2014

Global climate change threatens the sustainability of agriculture and agroforestry worldwide through increased heat, drought, surface evaporation and associated soil drying. Exposure of crops and forests to warmer and drier environments will increase leaf:air water vapour–pressure deficits (VPD), and will result in increased drought susceptibility and reduced productivity, not only in arid regions but also in tropical regions with seasonal dry periods. Fast‐growing, short‐rotation forestry (SRF) bioenergy crops such as poplar (Populus spp.) and willow (Salix spp.) are particularly susceptible to hydraulic failure following drought stress due to their isohydric nature and relatively high stomatal conductance. One approach to sustaining plant productivity is to improve water‐use efficiency (WUE) by engineering crassulacean acid metabolism (CAM) into C3 crops. CAM improves WUE by shifting stomatal opening and primary CO2 uptake and fixation to the night‐time when leaf:air VPD is low. CAM members of the tree genus Clusia exemplify the compatibility of CAM performance within tree species and highlight CAM as a mechanism to conserve water and maintain carbon uptake during drought conditions. The introduction of bioengineered CAM into SRF bioenergy trees is a potentially viable path to sustaining agroforestry production systems in the face of a globally changing climate.
Induced mild systemic inflammation is associated with impaired ability to improve cognitive task performance by practice
Authors: Paine Nicola J. , Bosch Jos A. , Ring Christopher , Drayson Mark T. , Veldhuijzen van Zanten Jet J. C. S.
Published: November 2014

Elevated inflammatory levels are linked to poorer cognition, but experimental confirmation is lacking. This report examined associations between cognitive performance and inflammation induced by exercise and vaccination. Thirty‐six (exercise N = 18, vaccination N = 18) healthy males completed a paced auditory serial addition test (PASAT), which is a multifaceted measure of cognitive function. The task was completed in placebo and elevated inflammation states. Improvements in PASAT performance were related to inflammation. In the exercise study, IL‐6 during the first PASAT negatively correlated with PASAT improvement (p = .022). In the vaccination study, increases in C‐reactive protein between PASATs correlated with reduced PASAT improvement (p < .001). Inflammation was linked to reduced improvements in cognitive performance. Further research should identify the specific cognitive functions affects and the underlying mechanisms.
Proverbs and the Evolution of Public Administration
Authors: Meier Kenneth J.
Published: November 2014

Herbert Simon, in his 1946 essay “The Proverbs of Administration,” indicted public administration as having conflicting and contradictory theories and an absence of a knowledge base that could provide a guide to practice. Simon proposed that public administration define concepts, adopt efficiency as its objective, focus on the study of decision making, and construct models that could predict efficient results. This 75th‐anniversary article revisits Simon's essay in light of contemporary public administration. It examines the progress that has been made and what still needs to be accomplished, and it ends with a list of barriers to further progress.
The Effect of Season on Spermatozoa Motility, Plasma Membrane and Acrosome Integrity in Fresh and Frozen–Thawed Semen from Xinong Saanen Bucks
Authors: Wang W , Luo J , Sun S , Xi L , Gao Q , Haile AB , Shi H , Zhang W , Shi H
Published: November 2014

Contents

The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.
Alpha‐Linolenic Acid Supplementation in Tris Extender Can Improve Frozen–Thawed Bull Semen Quality
Authors: Kaka A , Wahid H , Rosnina Y , Yimer N , Khumran AM , Behan AA , Ebrahimi M
Published: November 2014

Content

The study was conducted to evaluate the effects of α‐linolenic acid (ALA) on frozen–thawed quality and fatty acid composition of bull sperm. For that, twenty‐four ejaculates obtained from three bulls were diluted in a Tris extender containing 0 (control), 3, 5, 10 and 15 ng/ml of ALA. Extended semen was incubated at 37°C for 15 min, to allow absorption of ALA by sperm cell membrane. The sample was chilled for 2 h, packed into 0.25‐ml straws and frozen in liquid nitrogen for 24 h. Subsequently, straws were thawed and evaluated for total sperm motility (computer‐assisted semen analysis), membrane functional integrity (hypo‐osmotic swelling test), viability (eosin‐nigrosin), fatty acid composition (gas chromatography) and lipid peroxidation (thiobarbituric acid‐reactive substances (TBARS)). A higher (p < 0.05) percentage of total sperm motility was observed in ALA groups 5 ng/ml (47.74 ± 07) and 10 ng/ml (44.90 ± 0.7) in comparison with control (34.53 ± 3.0), 3 ng/ml (34.40 ± 2.6) and 15 ng/ml (34.60 ± 2.9). Still, the 5 ng/ml ALA group presented a higher (p < 0.05) percentage of viable sperms (74.13 ± 0.8) and sperms with intact membrane (74.46 ± 09) than all other experimental groups. ALA concentration and lipid peroxidation in post‐thawed sperm was higher in all treated groups when compared to the control group. As such, the addition of 5 ng/ml of ALA to Tris extender improved quality of frozen–thawed bull spermatozoa.
Expression of Bovine Ecat1 Gene in Immature and in vitro Matured Oocytes as Well as During Early Embryonic Development
Authors: Zahmatkesh A , Ansari Mahyari S , Daliri Joupari M , Shirazi A , Rahmani H
Published: November 2014

Contents

Ecat1 is a maternal effect gene that is exclusively expressed in oocytes and embryonic stem cells, and has an important role in pre‐implantation development. This study was designed to investigate the expression of bovine Ecat1 gene in immature and in vitro matured oocytes as well as during early embryonic development, and also Ecat1 protein localization. Samples were obtained from slaughtered animals. RNA extractions were carried out from ovary, immature and in vitro matured oocytes and also different stages of embryonic development (2‐, 4‐, 8‐ to 16‐cell stages and blastocysts). RT‐PCR analysis revealed the expression of Ecat1 in ovary, oocytes and embryos. Analysis in FGENESH online tool predicted three exons and one transcription start site (TSS) in Ecat1 gene, and the 3′ RACE‐PCR result showed that just one splice variant was amplified. By quantitative real‐time PCR technique, we showed that Ecat1 transcript increased at 8‐ to 16‐cell‐stage embryos and decreased in blastocyst stage (p < 0.05). Immunofluorescence analysis showed cytoplasmic localization of Ecat1 protein in bovine oocytes. Results demonstrated bovine Ecat1 expression at protein level and also indicated that Ecat1 has a significant higher embryonic expression at 8‐ to 16‐cell stage. This embryonic expression is probably required for further developmental stages.
Log‐mean Linear Parameterization for Discrete Graphical Models of Marginal Independence and the Analysis of Dichotomizations
Authors: Roverato Alberto
Published: November 2014

We extend the log‐mean linear parameterization for binary data to discrete variables with arbitrary number of levels and show that also in this case it can be used to parameterize bi‐directed graph models. Furthermore, we show that the log‐mean linear parameterization allows one to simultaneously represent marginal independencies among variables and marginal independencies that only appear when certain levels are collapsed into a single one. We illustrate the application of this property by means of an example based on genetic association studies involving single‐nucleotide polymorphisms. More generally, this feature provides a natural way to reduce the parameter count, while preserving the independence structure, by means of substantive constraints that give additional insight into the association structure of the variables. © 2014 Board of the Foundation of the Scandinavian Journal of Statistics
Allotype analysis to determine the origin of cytomegalovirus immunoglobulin‐G after allogeneic stem cell transplantation
Authors: Yamazaki R. , Tanaka Y. , Nakasone H. , Sato M. , Terasako‐Saito K. , Sakamoto K. , Akahoshi Y. , Nakano H. , Ugai T. , Yamasaki R. , Wada H. , Ishihara Y. , Kawamura K. , Ashizawa M. , Kimura S.‐I. , Kikuchi M. , Kako S. , Kanda J. , Tanihara A. , Nishida J. , Kanda Y.
Published: November 2014

Background

Cytomegalovirus (CMV) reactivation still remains a major problem following allogeneic hematopoietic stem cell transplantation (HSCT).

Patients and methods

In this study, we analyzed an immunoglobulin allotype, IgG1m(f), in CMV‐seropositive HSCT recipients and their donors to distinguish donor‐derived antibody from recipient‐derived antibody. Eight donor‐recipient pairs were informative regarding the appearance of donor‐derived immunoglobulin‐G (IgG), as the recipients were homozygous null for the IgG1m(f) allotype and the donors were IgG1m(f) positive. In these patients, total IgG, IgM, and allotype‐specific IgG against CMV were measured by enzyme‐linked immunosorbent assay. All subjects were monitored for at least 9 months after HSCT with (n = 5) or without (n = 3) CMV reactivation.

Results

Donor‐derived CMV IgG tended to be elevated earlier in patients with CMV‐seropositive donors than in those with CMV‐seronegative donors. In 1 patient with a CMV‐negative donor, donor‐derived CMV IgG was not detected until late CMV reactivation. In 3 patients without CMV reactivation, donor‐derived CMV IgG was also elevated within 1–6 months after HSCT.

Conclusion

In conclusion, the CMV serostatus of the donor may be related to the timing of the appearance of donor‐derived CMV IgG and the reconstitution of humoral immunity against CMV, regardless of the CMV antigenemia level after HSCT.