bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence of pine species in late‐successional forests: evidence from habitat‐related variation in stand age structure
Authors: Fahey Robert T. , Lorimer Craig G. 
Published: May 2013

AbstractQuestionsBy what mechanisms do early‐successional tree species such as pines persist in late‐successional forests in regions where recurrence intervals for stand‐replacing disturbance are much longer than maximum tree life spans? How are recruitment patterns affected by habitat variation?LocationOld‐growth, mixed species stands ofPinus strobus, Pinus resinosa, Tsuga canadensisandAcer saccharumat 36 locations in three subregions of northeast Wisconsin and west upper Michigan,USA.MethodsFour to nine stands were located in each of six habitats and sampled in 200‐m2plots. Increment cores were collected from 1456 trees, and charcoal collected and dated to characterize stand age structure and disturbance history. Stands on upland mesic sites, with strong successional trends toward late‐successional species, were compared to those on ‘marginal’ habitats (rock outcrops, sandy inclusions and lake, river and wetland edges), where competition is comparatively low. We developed a new methodology that utilizes uncertainty in establishment dates to more rigorously distinguish even‐aged stands (the null hypothesis) from those with multiple age classes.ResultsAnalysis of tree germination dates suggests that some stands with an apparently broad range of pine ages primarily reflect uncertainty in age estimates rather than actual periods of extended pine recruitment. Nevertheless, multi‐aged populations of pine (rejection of the even‐aged null hypothesis) were found in 86% of the stands and in all habitats. Marginal habitats had more age classes than mesic sites (mean 2.8 vs 1.7;P = 0.007) and greater age diversity. Disturbances that initiated pine cohorts were more often severe and more often caused by fire on mesic sites than on marginal habitats. Pine establishment was somewhat episodic in all three subregions, but age‐class peaks across subregions had limited synchrony and were not strongly correlated with severe drought.ConclusionsThese findings are consistent with growing evidence that age structures of early‐successional tree species in primary forests are often more complex than commonly believed, and that population structure and persistence are strongly influenced by habitat variation. Pine age structures provide indirect support for ‘refuge‐based’ landscape persistence, with dispersal limitation overcome by persistent seed sources in nearby marginal habitats.
Unconventional Results with Surrogate Production Functions
Authors: Opocher Arrigo , Steedman Ian 
Published: May 2013

AbstractStarting from Samuelson's famous 1962 Surrogate Production Function, we show that some such functions are perfectly consistent with a ‘return of the machine type’. This is so when we introduce a distinctly conventional possibility—that of machine–labour substitution—instead of Samuelson's fixed proportions, within every technique. We also show that, in the presence of two primary inputs, the surrogate model can give distinctly unconventional primary input use/input price relations at the level of the consumer good industry, even if the rate of interest is identically null.
Metabolite‐dependent regulation of gene expression in Trypanosoma brucei
Authors: Kim Dong‐Hyun , Barrett Michael Peter 
Published: May 2013

SummaryMechanisms regulating gene expression in trypanosomatid protozoa differ significantly from those in other eukaryotes. Transcription of the genome appears to be more or less constitutive with the polyadenylation and trans‐splicing of large polycistronic RNAs producing monocistronic RNAs whose translation may then depend upon information within their 3′ untranslated regions (3′UTRs). Various 3′UTR sequences involved in life‐cycle stage‐dependent differential gene expression have been described. Moreover, several RNA‐binding proteins have been implicated in regulating expression of these transcripts through altering either their stability or their ability to interact with ribosomes. In this issue of Molecular Microbiology Xiao et al. report on a regulatory element within the 3′UTR of the transcript that encodes the polyamine pathway regulatory protein called prozyme. It appears that the RNA element controls translation of the prozyme RNA causing expression to be upregulated when levels of decarboxylated S‐adenosylmethionine (dcAdoMet) are depleted. Since prozyme activates the enzyme S‐adenosylmethionine decarboxylase (AdoMetDC), which is responsible for the production of dcAdoMet, losing this metabolite leads to upregulation of prozyme, activation of AdoMetDC and restoration of optimal levels of dcAdomet. The system thus represents a novel metabolite‐sensing regulatory circuit that maintains polyamine homeostasis in these cells.
Multiple loci and genetic interactions involving flowering time genes regulate stem branching among natural variants of Arabidopsis
Authors: Huang Xueqing , Ding Jia , Effgen Sigi , Turck Franziska , Koornneef Maarten 
Published: May 2013

Summary

Shoot branching is a major determinant of plant architecture. Genetic variants for reduced stem branching in the axils of cauline leaves of Arabidopsis were found in some natural accessions and also at low frequency in the progeny of multiparent crosses.

Detailed genetic analysis using segregating populations derived from backcrosses with the parental lines and bulked segregant analysis was used to identify the allelic variation controlling reduced stem branching.

Eight quantitative trait loci (QTLs) contributing to natural variation for reduced stem branching were identified (REDUCED STEM BRANCHING 1–8 (RSB1–8)). Genetic analysis showed that RSB6 and RSB7, corresponding to flowering time genes FLOWERING LOCUS C (FLC) and FRIGIDA (FRI), epistatically regulate stem branching. Furthermore, FLOWERING LOCUS T (FT), which corresponds to RSB8 as demonstrated by fine‐mapping, transgenic complementation and expression analysis, caused pleiotropic effects not only on flowering time, but, in the specific background of active FRI and FLC alleles, also on the RSB trait.

The consequence of allelic variation only expressed in late‐flowering genotypes revealed novel and thus far unsuspected roles of several genes well characterized for their roles in flowering time control.
Hydraulic tuning of vein cell microstructure in the evolution of angiosperm venation networks
Authors: Feild Taylor S. , Brodribb Timothy J. 
Published: May 2013

Summary

High vein density (DV) evolution in angiosperms represented a key functional transition. Yet, a mechanistic account on how this hydraulic transformation evolved remains lacking. We demonstrate that a consequence of producing high DV is that veins must become very small to fit inside the leaf, and that angiosperms are the only clade that evolved the specific type of vessel required to yield sufficiently conductive miniature leaf veins.

From 111 species spanning key divergences in vascular plant evolution, we show, using analyses of vein conduit evolution in relation to vein packing, that a key xylem innovation associated with high DV evolution is a strong reduction in vein thickness and simplification of the perforation plates of primary xylem vessels.

Simple perforation plates in the leaf xylem occurred only in derived angiosperm clades exhibiting high DV (> 12 mm mm−2). Perforation plates in the vessels of other species, including extant basal angiosperms, consisted of resistive scalariform types that were associated with thicker veins and much lower DV.

We conclude that a reduction in within‐vein conduit resistance allowed vein size to decrease. We suggest that this adaptation may have been a critical evolutionary step that enabled dramatic DV elaboration in angiosperms.
Elevated serum IgE in recurrent aphthous stomatitis and associations with disease characteristics
Authors: Almoznino G , Zini A , Mizrahi Y , Aframian DJ 
Published: May 2013

ObjectivesTo characterize demographic, clinical and serological parameters in recurrent aphthous stomatitis (RAS) patients and analyse their association with serum immunoglobulin E (IgE) levels.Subjects and MethodsForty‐nine patients with RAS responded to a questionnaire that included demographic background, stress status, smoking habits, history and course of RAS episodes. They were also subjected to relevant laboratory tests, including determination of serum IgE levels.ResultsA familial history of RAS was reported by 47.9% of the patients, stress in the previous year by 51.1% and smoking by 18.4%. Non‐Caucasian origin, familial history of RAS, stress and smoking were associated with increased severity of RAS episodes. Haematological deficiencies were observed in 18.7% of RAS patients. Average IgE levels were increased and were significantly associated ‎with younger ‎age, ‎≤12 years of schooling, ‎female gender, ‎RAS ‎episode frequency of every ‎2 weeks‎,‎ early onset of RAS episodes and elevated C reactive protein levels.ConclusionImmunoglobulin E levels may be considered as part of the RAS patient's work‐up. Further research is needed to identify biological mechanisms that account for the observed associations.
MiR‐99a exerts anti‐metastasis through inhibiting myotubularin‐related protein 3 expression in oral cancer
Authors: Kuo Y‐Z , Tai Y‐H , Lo H‐I , Chen Y‐L , Cheng H‐C , Fang W‐Y , Lin S‐H , Yang C‐L , Tsai S‐T , Wu L‐W 
Published: May 2013

ObjectiveWe aimed at studying the role of the most deregulated miR‐99a, identifying its downstream targets, and exploring the clinical potential of miR‐99a and its target(s) in oral cancer.Subjects and MethodsFollowing confirmation of miR‐99a deregulation in nine oral lines and 26 pairwise clinical specimens, miR‐99a‐manipulated oral cancer cells were subjected to cell proliferation, migration, invasion, and in vivo murine metastasis assays. We characterized putative miR‐99a target(s) using luciferase reporter assays and genetic manipulation. The inverse relation of miR‐99a and its target(s) was examined in clinical specimens using real‐time PCR and Western blot analysis.ResultsMiR‐99a down‐regulation was confirmed both in tested oral cancer cell lines and clinical specimens. Ectopic miR‐99a expression inhibited oral cancer cell migration and invasion. Anti‐miR‐99a, silencing miR‐99a functions, had the opposite effect. Myotubularin‐related protein 3 (MTMR3) with one evolutionarily conserved seed region in the 3′‐untranslated region was a novel miR‐99a target. Depleting MTMR3 expression significantly reduced cell proliferation, migration, or invasion. There was an inverse expression of miR‐99a and MTMR3 protein in oral cancer lines and clinical specimens.ConclusionmiR‐99a repressed oral cancer cell migration and invasion partly through decreasing MTMR3 expression. MTMR3 may serve as a therapeutic target for oral cancer treatment.
Carotenoid accumulations and carotenogenic gene expressions in the petals of Eustoma grandiflorum
Authors: Liu Hui , Kishimoto Sanae , Yamamizo Chihiro , Fukuta Naoko , Ohmiya Akemi 
Published: May 2013

AbstractEustoma grandiflorum is one of the leading cut‐flowers in Japan. There are market demands for cultivars with deep‐yellow flowers, but they have never been bred successfully. By investigating the carotenoid accumulation and carotenogenic gene expressions, this study attempted to explore the reasons that block the formation of deep‐yellow colour in Eustoma. High performance liquid chromatography analysis showed that the carotenoid compositions in petals were similar to those in leaves, accumulating mainly lutein, violaxanthin and β‐carotene. The total carotenoid contents decreased as the petals matured in all the cultivars tested. Quantitative real‐time PCR analysis showed that the expression levels of PSY, LCYB, ZDS and LCYE showed significant differences between white and pale‐yellow petals or between petals and leaves, indicating that these enzymes may play a key role in the carotenoid biosynthesis in E. grandiflorum. The expression levels of CCD4 were high in both pale‐yellow and white petals during development, suggesting that carotenoid degradation activity is high in the petals. We then conclude that the total carotenoid accumulation level could be determined by the balance between carotenoid biosynthesis and degradation activities.
The likelihood of sunburn in sunscreen users is disproportionate to the SPF
Authors: Pissavini Marc , Diffey Brian 
Published: May 2013

SummaryBackground/ObjectiveSunburn is a common feature in sunscreen users. The purpose of this paper is to estimate the expected frequency and magnitude of sunburn resulting from typical use of sunscreens labelled SPF15 and SPF30 by people spending long periods outdoors in strong summer sunshine.MethodsBy combining the probability distribution of the measured sun protection factor (SPF) in vivo with those for the average application thickness and the uniformity of application over the skin surface, a simulation model was developed to estimate the variation in delivered protection over the exposed skin surface from consumer use of sunscreens.ResultsWhile either sunscreen, if delivering the nominal SPF over the entire exposed skin, would be sufficient to prevent any erythema, the simulation indicates that the combination of the average quantity applied with the variability in thickness over the skin surface will lead to erythema, especially in SPF15 sunscreen users.ConclusionPeople who intend spending long periods outside in strong sunshine would be better advised to use SPF30 labelled sunscreens than SPF15 sunscreens, and to apply the product carefully over exposed skin if they wish to minimize their risk of sunburn and, by implication, skin cancer.
Photopatch testing in Asians: a 5‐year experience in Singapore
Authors: Chuah Sai Yee , Leow Yung Hian , Goon Anthony Teik Jin , Theng Colin Thiam Seng , Chong Wei‐Sheng 
Published: May 2013

SummaryBackgroundPhotopatch testing is important for diagnosing photoallergic contact dermatitis. We aimed to evaluate the use of photopatch test at the National Skin Centre, Singapore.MethodsAll patients who had photopatch tests done between 2007 and 2011 at the National Skin Centre were included.ResultsTwenty‐two patients were included. The mean age was 40.2. Female : male ratio was 3.4. The ethnic groups were Chinese (68%), Malay (4%), Indian (14%) and others (14%). Ten out of 22 patients (45.5%) had a positive photopatch test. There were 20 positive photopatch test reactions found in these 10 patients, and all 20 positive reactions were of current relevance. The frequencies of the positive photopatch test reactions were 2‐hydroxy‐4‐methoxybenzophenone (oxybenzone) (n = 6), 2‐hydroxymethoxymethylbenzophenone (mexenone) (n = 3), 2‐ethylhexyl‐4‐dimethylaminobenzoate (n = 1), ketoprofen gel (n = 1) and the patient's own product (n = 9).ConclusionsOur study suggests that sunscreen is the most common photoallergen to date as opposed to musk ambrette, which was the most common photoallergen in our earlier study in 1991–1993. This finding is similar to the recent European Multicentre Photopatch Test Study.
UV responses in Native Hawaiians and Pacific Islanders, and, Asians residing in Hawai'i and in Maryland
Authors: Colmenares Leticia U. , Coelho Sergio , Miller Sharon A. , Boomer K. B. , Beer Janusz Z. 
Published: May 2013

SummaryBackgroundUV exposure causes a wide range of skin damage including cutaneous melanoma. The mechanisms of cellular and molecular damage, as well as those of erythemal and pigmentation responses to UV exposure, have largely been studied in the White population.MethodsThis study systematically investigates responses to UV exposure in the Native Hawaiian and Pacific Islander (NHPI) and Asian populations living in Hawai'i (A/HI) as well as in Asians living in Maryland (A/MD).ResultsOur analyses indicate that the NHPI population is less sensitive to UV exposure than the A/HI population. Comparisons between the two Asian groups suggest that, despite slightly but not statistically different baseline constitutive pigmentation (pre‐UV exposure), the A/HI and A/MD had similar UV sensitivity, measured as minimal erythemal dose (MED). However, the A/MD population had higher levels of oxyhemoglobin at doses of 2.0, 2.8 and 4.0 MED. Unexpectedly, the A/MD subjects retained higher levels of pigmentation 2 weeks post‐UV exposure.ConclusionThis study provides insight into UV responses of the inhabitants of Hawai'i and shows that such responses are statistically significant for relatively small samples of NHPI and for A/HI and A/MD.
A case of cutaneous lichen sclerosus et atrophicus effectively treated by extracorporeal photochemotherapy
Authors: Brouillard Clotilde , Granel‐Brocard Florence , Cuny Jean‐François , Truchetet François , Schmutz Jean‐Luc 
Published: May 2013

SummaryLichen sclerosus et atrophicus (LSA) is an inflammatory disease that affects the genitals, which was first described by Hallopeau in 1887 and is of unknown etiology. Only 15% of patients have an associated extra‐genital form, and 2.5% have an isolated extra‐genital form. LSA treatment remains poorly codified and mostly empirical. Here, we report a case of LSA, of mainly cutaneous form, which was effectively treated using extracorporeal photochemotherapy (ECP). Remission was achieved quickly, after the fourth session, with excellent treatment tolerance. ECP is now recognized as an effective treatment for erosive lichen planus, graft‐versus‐host disease (GVHD), and scleroderma. Thus, we began ECP treatment for our cases of LSA based on clinical and/or anatomopathological similarities between LSA and these commonly ECP‐treated disorders. The fact that ECP is effective in LSA, GVHD, erosive lichen planus, and scleroderma strengthen the hypothesis that there is a common link between these four conditions.
Identification and characterisation of maize microRNAs involved in developing ears
Authors: Ding D. , Li W. , Han M. , Wang Y. , Fu Z. , Wang B. , Tang J. 
Published: May 2013

AbstractIn maize, kernel row number trait is determined during the period when spikelet pair meristems (SPMs) give rise to spikelet meristems (SMs). Expression levels of many genes change during this period due to regulation at transcriptional and post‐transcriptional levels. MicroRNAs (miRNAs) act as key regulating factors of post‐transcriptional gene expression. To discover miRNAs involved in maize ear development, Solexa deep sequencing was performed on a maize inbred line, Zong3. Ears at the stage when SPMs produce SMs were harvested to extract RNA. Deep sequencing revealed 85 conserved miRNAs belonging to 17 miRNA families. miRNA families differed greatly in their abundance, from over 160,000 to only five reads. In addition, 31 novel maize miRNAs were identified using stringent criteria. The results show that miRNA‐mediated regulation of gene expression is present in developing maize ears at the stage when SPMs produce SMs; both conserved and novel miRNAs are involved.
Significance of microalgal–bacterial interactions for aquaculture
Authors: Natrah Fatin M. I. , Bossier Peter , Sorgeloos Patrick , Yusoff Fatimah Md. , Defoirdt Tom 
Published: May 2013

AbstractKnowledge on the importance of associations between bacteria and microalgae in aquatic ecosystems is rather limited at the moment, mostly due to a lack of studies at the molecular and biochemical level of microorganisms. This paper discusses the current knowledge on microalgae–bacteria interactions and their potential impacts on the productivity, efficiency and sustainability of aquaculture. Current findings suggest that the interactions are complex and specific. The release of stimulatory products by bacteria that enhance the growth of microalgae, and vice versa, indicates the existence of mutualistic relations. Other factors, such as signalling between bacteria and microalgae, may also play an important role. Although these interactions may be of significant importance, to date, only a few findings have been reported on the use of consortia consisting of microalgae and bacteria for practical purposes. Interestingly, these results pointed out that a combination of microalgae and bacteria is often better than using either of them alone. Further research is needed to obtain a thorough understanding of the mechanisms behind the interactions between these microorganisms, including the identification of active compounds. This knowledge will enable the selection of appropriate consortia for different applications in aquaculture, including disease control and high and sustainable production of feed.
Virulence mechanisms of bacterial aquaculture pathogens and antivirulence therapy for aquaculture
Authors: Defoirdt Tom 
Published: May 2013

AbstractAlthough aquaculture continues to be the fastest‐growing food‐producing industry worldwide, the sector faces important challenges with respect to controlling infectious diseases. Indeed, the frequent use of antibiotics, which are traditionally the most important line of defence against bacterial disease, has raised problems related to the development and spread of resistance. As a result, we currently are in a race to develop novel therapeutics that should allow us to continue controlling bacterial disease in the future. In this respect, scientific progress of the past years has allowed us to start understanding the mechanisms by which bacterial pathogens are causing disease. This knowledge in its turn opens up novel possibilities to combat infections by interfering with these mechanisms, a strategy that has been termed antivirulence therapy. In this review, the current knowledge with respect to pathogenicity mechanisms of bacterial aquaculture pathogens is discussed, including adhesion mechanisms, production of extracellular polysaccharides and biofilm formation, production of lytic enzymes (e.g. haemolysins and proteases), mechanisms of iron acquisition, secretion systems and regulatory mechanisms such as quorum sensing and host–pathogen signalling with catecholamine stress hormones. Furthermore, an overview is given of the first steps towards antivirulence therapy for aquaculture, with a focus on quorum sensing disruption as a proof of concept.
A rare presentation of multiple primary squamous cell carcinoma of the tongue in a patient with recurrent hepatitis C infection
Authors: Stoopler Eric T. , Sia Ying Wai , Chalian Ara A. , O'Malley Bert W. , Alawi Faizan 
Published: May 2013

ABSTRACTHepatitis C virus (HCV) infection has been implicated as a risk factor for development of oral squamous cell carcinoma (SCC). Multiple primary sites of oral SCC associated with HCV infection occurs infrequently. This case report describes a rare presentation of multiple primary SCCs of the tongue in a patient with recurrent HCV cirrhosis status post liver transplant that required interdisciplinary medical and surgical management. It is important for oral health care providers to understand the local and systemic implications of HCV infection and perform routine clinical examinations to monitor for development of oral lesions and associated complications.