bluuebunny/crossref_metadata_2025 huggingface dataset:
The necrotrophic effector SnToxA induces the synthesis of a novel phytoalexin in wheat
Authors: Du Fall Lauren A. , Solomon Peter S.
Published: June 2013

Stagonospora nodorum and Pyrenophora tritici‐repentis produce the effector ToxA that interacts with the dominant susceptibility gene in wheat, Tsn1. However, the way in which ToxA induces cell death and causes disease is unclear.

Here, we performed comprehensive metabolite profiling of ToxA‐infiltrated wheat (Triticum aestivum) to observe the secondary metabolite response to this effector.

A strong induction of secondary metabolism subsequent to SnToxA infiltration was observed, including the monoamine serotonin. We established a novel role for serotonin as a phytoalexin in wheat and demonstrated that serotonin strongly inhibited sporulation of S. nodorum. Microscopy revealed that serotonin interferes with spore formation and maturation within pycnidial structures of the fungus. Subsequent analysis of S. nodorum exposed to serotonin revealed metabolites changes previously associated with sporulation, including trehalose and alternariol. Furthermore, we identified significantly lower concentrations of serotonin during infection compared with infiltration with ToxA, providing evidence that S. nodorum may suppress plant defence.

This is the first study demonstrating induction of plant secondary metabolites in response to a necrotrophic effector that have significant antifungal potential against the pathogen. While it is generally accepted that necrotrophs exploit host cell responses, the current research strengthens the notion that necrotrophs require mechanisms to overcome plant defence to survive initial stages of infection.
Break Date Estimation for Models with Deterministic Structural Change
Authors: Harvey David I. , Leybourne Stephen J.
Published: June 2013

In this article, we consider estimating the timing of a break in level and/or trend when the order of integration and autocorrelation properties of the data are unknown. For stationary innovations, break point estimation is commonly performed by minimizing the sum of squared residuals across all candidate break points, using a regression of the levels of the series on the assumed deterministic components. For unit root processes, the obvious modification is to use a first differenced version of the regression, while a further alternative in a stationary autoregressive setting is to consider a GLS‐type quasi‐differenced regression. Given uncertainty over which of these approaches to adopt in practice, we develop a hybrid break fraction estimator that selects from the levels‐based estimator, the first‐difference‐based estimator, and a range of quasi‐difference‐based estimators, according to which achieves the global minimum sum of squared residuals. We establish the asymptotic properties of the estimators considered, and compare their performance in practically relevant sample sizes using simulation. We find that the new hybrid estimator has desirable asymptotic properties and performs very well in finite samples, providing a reliable approach to break date estimation without requiring decisions to be made regarding the autocorrelation properties of the data.
Effects of exercise on resting blood pressure in obese children: a meta‐analysis of randomized controlled trials
Authors: García‐Hermoso A. , Saavedra J. M. , Escalante Y.
Published: June 2013

The purpose of this meta‐analysis was to examine the evidence for the effectiveness of exercise interventions on the resting blood pressure (systolic and diastolic) of obese children. A computerized search was made of seven databases using keywords. Effect sizes (ES) and 95% confidence intervals were calculated, and the heterogeneity of the studies was estimated using Cochran's Q‐statistic applied to the effect size means. Nine randomized controlled trial (RCT) studies were selected for review as satisfying the inclusion criteria (n = 205 exercise, 205 control). The main cumulative evidence indicates that the exercise programmes with a frequency of three sessions weekly lasting longer than 60 min had a moderate effect on systolic blood pressure (ES = −0.46, I2 = 27%), and programmes of under 12 weeks with more than three sessions weekly were beneficial in terms of reduction of diastolic blood pressure (ES = −0.35, I2 = 78%).
Cone‐beam computed tomography for oral surgical applications: where is the evidence?
Authors: Horner K.
Published: June 2013

Dental cone‐beam computed tomography (CBCT) has been available for only about 15 years, but has already found many uses in the practice of oral surgery despite a limited evidence base for its diagnostic efficacy. As with all X‐ray techniques, careful attention must be given to justification and optimisation. It is usually associated with higher radiation doses and financial costs than conventional radiographic techniques, yet has corresponding advantages over multislice computed tomography. Equipment varies considerably in image quality, and it is hard to generalise about its clinical use, although it usually has acceptable accuracy for linear measurements. In terms of clinical applications, much of the literature remains dominated by opinion and case reports, with little published work relating to patient outcome efficacy. In implant dentistry, its use is well established, and guideline documents exist which favour selected use. For mandibular third molar surgery, it has good diagnostic accuracy for inferior dental canal relationships but, apart from ‘high‐risk’ cases, there is no evidence to support routine use. It has many other potential uses where three‐dimensional information will be of help. Use of CBCT has implications for training of users. At this time, the evidence base suggests that a restrained approach in using CBCT is appropriate, limiting it to situations where conventional radiography cannot provide the information required to manage a patient adequately, or to those where multislice computed tomography is the current imaging modality of choice and where limited soft tissue contrast is acceptable.
Relapse of minimal change nephrotic syndrome after intravitreal bevacizumab
Authors: Sato Tomoko , Kawasaki Yukihiko , Waragai Tomoko , Imaizumi Tomoko , Ono Atsushi , Sakai Nobuko , Hosoya Mitsuaki
Published: June 2013

Reported herein is a case of relapse of nephrotic syndrome (NS) after intravitreal injection of bevacizumab, a monoclonal antibody that binds to vascular endothelial growth factor (VEGF), in a 16‐year‐old girl. She had a diagnosis of steroid‐dependent NS and had been treated with prednisolone, and remained in remission. The patient had had visus brevior 10 years previously, and was diagnosed with severe myopic choroidal neovascularization (mCNV). Intravitreal bevacizumab was given for mCNV. At 9 days after intravitreal injection of bevacizumab, proteinuria was positive. The patient had relapse of NS caused by bevacizumab, and steroid pulse therapy was then given and the proteinuria resolved. It is necessary to take particular care to prevent NS relapses in patients with mCNV treated with intravitreal bevacizumab.
Neonatal orbital abscess
Authors: Lin Chien‐Yu , Chiu Nan‐Chang , Lee Kuo‐Sheng , Huang Fu‐Yuan , Hsu Chyong‐Hsin
Published: June 2013

Orbital abscess is life‐threatening and rare in children. Reported herein is a term male neonate who had methicillin‐resistant Staphylococcus aureus orbital abscess, and a literature review of this disease. A total of 16 neonates diagnosed with neonatal orbital abscess are reported in the literature. There is a mild male predilection and two neonates were delivered prematurely. Leukocytosis, fever, ethmoiditis and associated upper respiratory tract infection were found in approximately half of them. Eight neonates had sepsis and 14 patients underwent surgical intervention. One patient died. Staphylococcus aureus was identified in 14 out of 17 patients. Neonatal orbital abscess is rarely encountered but may be fatal. Although streptococci are prevalent in childhood orbital infection, S. aureus was predominant in neonatal orbital abscess in the present series. Appropriate antimicrobial therapy against S. aureus is essential in treating neonatal orbital abscess. This case suggests that a higher initial dose of vancomycin may be an effective and safe strategy for severe S. aureus infection in neonates.
Skin hamartoma on the hand of a newborn infant
Authors: Kaga Akimune , Itabashi Chieko , Kanda Susumu , Suzuki Yutaka , Tanabu Muneyuki , Kure Shigeo
Published: June 2013

Skin hamartoma is an extremely rare disease on the hand in newborn infants. Reported herein is the case of a newborn infant who presented with a skin hamartoma on the hand. The patient was a girl born at 37 weeks of gestational age. The mass was seen on her proximal left thumb at birth. The mass had a spherical diameter of 4 cm and was pedunculated. One the day after birth, the stalk on the mass was ligated in the neonatal intensive care unit. The mass was diagnosed as skin hamartoma on histopathology. At 1 year of age, the child had good hand function, and no recurrence of the neoplasia was evident.
Langerhans cell histiocytosis in non‐twin siblings
Authors: Yoon Jong Hyung , Park Hyeon Jin , Park Seog‐Yun , Park Byung‐Kiu
Published: June 2013

Langerhans cell histiocytosis (LCH), which has unknown pathogenesis, can manifest as many kinds of signs and symptoms at any age. Although its genetic background has not been exactly identified, the familial clustering of this disease has been described in some reports. It is very uncommon, however, in siblings who are not monozygotic or dizygotic twins. Reported herein is a case of LCH in non‐twin siblings (younger sister and elder brother) who were diagnosed at 3.3 and 14.5 years of age, respectively, and successfully treated with chemotherapy, with BRAF V600E mutation status, and a brief review of the literature.
Clinical spectrum of cleidocranial dysplasia in a family with twins
Authors: Wang Jiangping , Huang Xinwen , Lai Can , Jiang Kewen
Published: June 2013

Cleidocranial dysplasia (CCD) is a rare congenital defect of autosomal dominant inheritance, primarily affecting bones that undergo intra‐membranous ossification. Herein is reported the case of monozygotic male 13‐year‐old twins with typical features of this syndrome, such as large wide‐open fontanels, abnormal clavicles with narrow, sloping shoulders that can be apposed at the midline, short stature, mid‐face hypoplasia, multiple supernumerary teeth, and skeletal anomalies. Their physical appearance led to the diagnosis of CCD. Genetic analysis found a C–T exchange in exon 2 at cDNA position 568, which changes the codon CGG for arginine to TGG for tryptophan (R190W) of the runt‐related transcription factor 2 RUNX2 gene. CCD should be suspected in patients with persistence of the widely open anterior fontanels and sutures, short stature, and poor clavicles, calvarium, or teeth. Timely recognition and hereditary tendency counseling is required and useful because of the possibility of covert transmissibility and sporadic genetic mutation.
What Is Wrong withHacker'sWittgenstein? On Grammar, Context and Sense‐Determination
Authors: Dobler Tamara
Published: June 2013

Peter Hacker defends an interpretation of the later Wittgenstein's notion of grammar, according to which the inherently general grammatical rules are sufficient for sense‐determination. My aim is to show that this interpretation fails to account for an important contextualist shift inWittgenstein's views on sense‐determination. I argue that Hacker attributes to the later Wittgenstein a rule‐based, combinatorial account of sense, which Wittgenstein puts forward in theTractatus. I propose that this is not how we should interpret the later Wittgenstein because he insists that particular circumstances of use play a necessary role in determining the boundary between sense and nonsense.
The Role of Bodily Perception in Emotion: In Defense of an Impure Somatic Theory
Authors: Barlassina Luca , Newen Albert
Published: June 2013

In this paper, we develop an impure somatic theory of emotion, according to which emotions are constituted by the integration of bodily perceptions with representations of external objects, events, or states of affairs. We put forward our theory by contrasting it with Prinz's (2004) pure somatic theory, according to which emotions are entirely constituted by bodily perceptions. After illustrating Prinz's theory and discussing the evidence in its favor, we show that it is beset by serious problems—i.e., it gets the neural correlates of emotion wrong, it isn't able to distinguish emotions from bodily perceptions that aren't emotions, it cannot account for emotions being directed towards particular objects, and it mischaracterizes emotion phenomenology. We argue that our theory accounts for the empirical evidence considered by Prinz and solves the problems faced by his theory. In particular, we maintain that our theory gives a unified and principled account of the relation between emotions and bodily perceptions, the intentionality of emotions, and emotion phenomenology.
Heterologous expression of tomato glycoside hydrolase family 3 α‐L‐arabinofuranosidase/β‐xylosidases in tobacco suspension cultured cells and synergic action of a family 51 isozyme under antisense suppression of the enzyme
Authors: Tateishi Akira , Kamiyoshihara Yusuke , Matsuno Junko , Miyohashi Fumika , Shiba Hajime , Kanayama Yoshinori , Watanabe Keiichi , Nomura Kazunari , Inoue Hiroaki
Published: June 2013

Four cDNA clones (SlArf/Xyl1‐4) encoding α‐l‐arabinofuranosidase/β‐xylosidase belonging to glycoside hydrolase family 3 were obtained from tomato (Solanum lycopersicum) fruit. SlArf/Xyl1 was expressed in various organs. Its level was particularly high in flower and leaves but low in fruit. SlArf/Xyl3 was highly expressed in flower. On the contrary, SlArf/Xyl2 and 4 were expressed in early developmental stage in various organs. Comparison with SlArf/Xyl4, SlArf/Xyl2 expression was observed in earlier stages. The active recombinant proteins were obtained by using BY‐2 tobacco (Nicotiana tabacum) suspension cultured cells. The SlArf/Xyl1 and 2 recombinant proteins showed a bi‐functional activity of α‐l‐arabinofuranosidase/β‐xylosidase while the SlArf/Xyl4 protein possessed a β‐xylosidase activity predominantly. Neither enzyme activities were detected for the SlArf/Xyl3 protein under the same conditions. Although SlArf/Xyl2 possessed a bi‐functional activity, it preferentially hydrolyzed arabinosyl residues from tomato hemicellulosic polysaccharides. Antisense suppression of SlArf/Xyl2 resulted in no apparent changes in the enzyme activities, monosaccharide composition or fruit phenotype. Increment of a family 51 α‐l‐arabinofuranosidase expression rather than that of family 3 resulted in a restoring the activity in SlArf/Xyl2‐suppressed fruit. The ability of recombinant SlArf/Xyl2 to hydrolyze both arabinan and arabinoxylan is nearly identical to that of α‐l‐arabinofuranosidases belonging to family 51. Our results suggested that BY‐2 cells are a useful expression system for obtaining active cell wall hydrolyzing enzymes. In addition, an α‐l‐arabinofuranosidase activity derived from SlArf/Xyl2 would be essential in young organ development and the action of the enzyme could be restored by the other enzyme belonging to a different family under a defective condition.
A Decision Support Tool to Compare Waterborne and Foodborne Infection and/or Illness Risks Associated with Climate Change
Authors: Schijven Jack , Bouwknegt Martijn , de Roda Husman Ana Maria , Rutjes Saskia , Sudre Bertrand , Suk Jonathan E. , Semenza Jan C.
Published: June 2013

Climate change may impact waterborne and foodborne infectious disease, but to what extent is uncertain. Estimating climate‐change‐associated relative infection risks from exposure to viruses, bacteria, or parasites in water or food is critical for guiding adaptation measures. We present a computational tool for strategic decision making that describes the behavior of pathogens using location‐specific input data under current and projected climate conditions. Pathogen‐pathway combinations are available for exposure to norovirus, Campylobacter, Cryptosporidium, and noncholera Vibrio species via drinking water, bathing water, oysters, or chicken fillets. Infection risk outcomes generated by the tool under current climate conditions correspond with those published in the literature. The tool demonstrates that increasing temperatures lead to increasing risks for infection with Campylobacter from consuming raw/undercooked chicken fillet and for Vibrio from water exposure. Increasing frequencies of drought generally lead to an elevated infection risk of exposure to persistent pathogens such as norovirus and Cryptosporidium, but decreasing risk of exposure to rapidly inactivating pathogens, like Campylobacter. The opposite is the case with increasing annual precipitation; an upsurge of heavy rainfall events leads to more peaks in infection risks in all cases. The interdisciplinary tool presented here can be used to guide climate change adaptation strategies focused on infectious diseases.
Addressing the oral healthcare needs of special needs children: pediatric nurses’ self‐perceived effectiveness
Authors: Parish Carrigan L. , Singer Richard , Abel Stephen , Metsch Lisa R.
Published: June 2013

Objectives

To examine the oral health knowledge and practices of pediatric nurses who coordinate healthcare services for special needs children and to identify those factors that influenced their perceived effectiveness in managing their patients’ oral health needs.

Methods

Self‐reported data were collected from 376 nurses employed at Children's Medical Services who responded to an online survey. Likert scale scores were used to specifically assess the nurses’ perceived effectiveness in addressing the oral health needs of special needs children.

Results

Characteristics significantly associated with special needs pediatric nurses who described themselves as “effective or very effective” included: the self‐perception of being very knowledgeable about basic oral health, receiving four or more hours of continuing education training, and securing dental appointments for the majority of their pediatric special needs patients with minimal waiting times.

Conclusion

Findings reveal that oral health knowledge significantly influenced nurses’ perceived effectiveness in addressing the oral health needs of special needs children, as well as their ability to secure timely dental appointments. These results support the need to incorporate oral health education into nursing curricula and expand upon the dental workforce available and willing to treat disabled patients.
A qualitative study of the dimensions of patients’ perceptions of facial disfigurement after head and neck cancer surgery
Authors: Costa Edmar Fernandes , Nogueira Túlio Eduardo , de Souza Lima Nathália Caroline , Mendonça Elismauro Francisco , Leles Cláudio Rodrigues
Published: June 2013

The study aim was to explore the underlying dimensions of patients’ perceptions and experiences of facial disfigurement following surgery for cancer treatment, using a qualitative approach based on individual in‐depth interviews. Data analysis and interpretation consisted of separating responses into phrases or statements with a single thematic aspect. Subsequently, a number of dimensions and categories were created using a deductive–inductive content analysis. Three main categories emerged: discovering of the cancer, coping with the disease and disfigurement, and reconstructing a new identity. The initial stage elicited feelings of fear, denial, and guilt as a reaction to the stigma and prejudice. Coping strategies included resignation and acceptance, deepening religiosity, reinforcement of familiar cohesion, and creation of a social network of solidarity and support. The final stage comprised incorporation of the altered facial image, rehabilitation possibilities, reconstruction of personality and self‐image, and the feeling of having overcome the disease. It was concluded that individual experiences are complex, challenging, and have striking effects on their lives. There is an urgent need for training and improvement in human resources to manage these patients in a multidisciplinary approach, aimed at their reintegration into society and reducing the prejudice and stigma of the disease and disfiguration.
A study of the behavior and mechanism of thermal conduction in the skin under moist and dry heat conditions
Authors: Igaki M. , Higashi T. , Hamamoto S. , Kodama S. , Naito S. , Tokuhara S.
Published: June 2013

Purpose

We analyzed skin heat conduction under moist and dry heat conditions to confirm the influence of moist heat on the skin and subcutaneous region.

Methods

Six healthy subjects placed their forearms in moist and dry heat air chambers, and the thickness of and moisture levels in the stratum corneum were measured. Skin surface temperatures, heat flux, and skin blood flow were measured in 11 healthy subjects.

Results

Within 10 min, the stratum corneum in skin exposed to moist heat reached a thickness of about 150%, and water content in the stratum corneum increased to about 200%. In contrast, the thickness of water content in the stratum corneum did not change in the dry heat condition. Skin surface temperatures of skin exposed to moist heat were significantly higher after 0.5 min of exposure (P < 0.01), the skin surface heat flux was greater, and blood flow was significantly higher (P < 0.05) after 10 min than that of skin exposed to dry heat.

Conclusion

Stratum corneum moisture levels and skin surface heat conductivity were higher in the moist heat condition and skin blood flow was significantly greater than that in skin exposed to dry heat. Therefore, moist heat is more efficient at warming the body than dry heat.
Expansion of recipient‐derived antiviral T cells may influence donor chimerism after allogeneic stem cell transplantation
Authors: Borchers S. , Weissinger E.M. , Pabst B. , Ganzenmueller T. , Dammann E. , Luther S. , Diedrich H. , Ganser A. , Stadler M.
Published: June 2013

Donor chimerism (DC) analysis is an important marker in the hematopoietic stem cell transplant follow‐up. Here, we present evidence for a possible relationship of infectious complications and declines in DC. We analyzed the DC in patients experiencing cytomegalovirus (CMV) reactivation. In addition, in some patients chimerism analyses of T‐cell subsets were performed. CMV‐specific cytotoxic T‐lymphocytes (CMV‐CTL) were monitored using human leukocyte antigen‐restricted multimer staining. Interestingly, CMV reactivation was accompanied by changes in DC in 11 of 67 patients transplanted. For example, DC declined in a cord blood recipient, in both total leukocytes and CD4 and CD8 T‐cell subsets upon CMV reactivation. The latter was controlled after only 5 days through expanding CMV‐CTL of 96% recipient origin, according to chimerism analysis of CMV‐CTL (enriched beyond 50%). In another patient, transplanted after reduced‐intensity conditioning from a DQB1 mismatched, CMV seronegative donor, incipient CMV reactivation was completely aborted by CMV‐CTL of recipient origin. However, at the same time, mixed chimerism dropped from 51% to 0% donor type, resulting in late graft rejection. Our data indicate that chimerism analyses in subset populations lead to a better understanding of declining total leukocyte chimerism. Furthermore, recipient‐derived CMV‐CTL may be able to control CMV reactivation after reduced‐intensity conditioning. We speculate that autologous CMV‐CTL may be instrumental to overcome recurrent CMV reactivations, especially in patients transplanted from CMV‐seronegative donors. In addition, the expansion of recipient‐derived CMV‐CTL may contribute to both, graft failure or to conversion to full DC.
Effects of gastric distension on intraabdominal pressures in horses
Authors: Barrett Elizabeth J. , Munsterman Amelia S. , Hanson R. Reid
Published: June 2013

Objective

To determine the effect of gastric distension on intraabdominal pressures (IAP) measured directly from the intraperitoneal space.

Design

Prospective, experimental study.

Setting

A university‐based equine research facility.

Animals

Ten healthy adult horses, 5 males and 5 females.

Interventions

Intraabdominal pressures were measured through an intraperitoneal cannula zeroed at a height midway between the height of the tuber ishii and point of the shoulder at 6 time points: at rest, after placement of a nasogastric tube, and after instillation of each 5 L increment up to a total of 20 L of water. Simultaneously, mean arterial pressures (MAP) were obtained using a tail cuff, and abdominal perfusion pressures (APP) were calculated using the measured IAP minus the measured MAP.

Measurements and Main Results

Baseline direct IAP measurements were subatmospheric (–4.5 ± 3.0 cm H2O). IAPs were not significantly affected by placement of a nasogastric tube (–2.69, 95% CI [–3.24, –2.14], P = 0.4195), but were significantly increased after placement of 5 L (–1.73, 95% CI [–2.28, –1.18], P = 0.0015), 10 L (–0.54, 95% CI [–1.09,0.01], P = 0.0001), 15 L (0.89, 95% CI [0.34, 1.44], P = 0.0001), or 20 L (3.08, 95% CI [2.53, 3.63], P = 0.0001) of water into the stomach. APPs were not significantly different for any volume of fluid infused into the stomach (P = 0.05 for all comparisons).

Conclusion

IAPs were significantly increased when > 5 L of water was infused into the stomach. These results indicate the need for further research in clinical cases to determine the relationship between gastric pressures and the development of intraabdominal hypertension in horses.
IMAGING DIAGNOSIS—CELIACOMESENTERIC TRUNK AND PORTAL VEIN HYPOPLASIA IN A PIT BULL TERRIER
Authors: Ricciardi Mario , Martino Rosmara , Assad Eyad Abu
Published: June 2013

The computed tomography (CT) imaging findings of a celiacomesenteric trunk (CMT) in a 1‐year‐old dog with primary hypoplasia of the portal vein (PHPV) are described. Computed tomography angiography revealed acquired porto‐systemic shunts secondary to portal hypertension and a common origin of the celiac and cranial mesenteric arteries. The imaging findings and the association of a CMT with other vascular diseases have never been reported in dogs. The recognition of this rare arterial anomaly should prompt to investigate possible concurrent vascular diseases and may influence the planning of abdominal surgeries.
PREVALENCE OF LATERAL VENTRICLE ASYMMETRY IN BRAIN MRI STUDIES OF NEUROLOGICALLY NORMAL DOGS AND DOGS WITH IDIOPATHIC EPILEPSY
Authors: Pivetta Mauro , De Risio Luisa , Newton Richard , Dennis Ruth
Published: June 2013

Asymmetry of the cerebral lateral ventricles is a common finding in cross‐sectional imaging of otherwise normal canine brains and has been assumed to be incidental. The purpose of this retrospective study was to compare the prevalence of ventricular asymmetry in brain MRI studies of normal dogs and dogs with idiopathic epilepsy. Brain MRI archives were searched for 100 neurologically normal dogs (Group 1) and 100 dogs with idiopathic epilepsy (Group 2). For each dog, asymmetry of the lateral ventricles was subjectively classified as absent, mild, moderate, and severe based on a consensus of two observers who were unaware of group status. Ventricular areas were measured from transverse T1W images at the level of the interthalamic adhesion. An asymmetry ratio was calculated as the ratio of the larger to smaller ventricular transverse area. There was excellent agreement between subjective assessments of ventricular asymmetry and quantitative assessments using asymmetry ratios (k = 0.995). The prevalence of asymmetry was 38% in Group 1 dogs and 44% in Group 2 dogs. Assymmetry was scored as mild in the majority of Group 2 dogs. There was no significant association between presence/absence and degree of ventricular asymmetry vs. dog group, age, gender, or skull conformation. Findings from the current study supported previously published assumptions that asymmetry of the lateral cerebral ventricles is an incidental finding in MRI studies of the canine brain.
Canopy gaps and tree regeneration patterns in multi-species unmanaged natural forest Sitno (preliminary results)
Authors: Danková Lucia , Saniga M.
Published: June 2013

The study of canopy gaps structure and tree regeneration patterns was conducted in mixed old-growth forest Sitno. We asked the following questions: What is the spatial scale of disturbance events? How does gap size affect the density of tree seedlings and saplings? Are there any differences in species composition of seedlings and saplings between the closed canopy and expanded gap? The research was conducted on a 2.5-ha (250 × 100 m) research plot. In total, 25 canopy openings were recorded. Canopy gaps and expanded gaps covered 22.8 % and 59.5 % of the research area. The most frequent were canopy gaps with the size up to 300 m2(64 %). Regarding the number of gapmakers, we recorded a quite large variability with the highest frequency of the gaps with 1 and 4 gapmakers. Regeneration structure (density and frequency) was sampled in 3.14 m2circular plot (n = 216) established on the grid intersections (10 × 10 m). A total of 8 tree species were identified in natural regeneration. The difference between overall density of natural regeneration under closed canopy and in expanded gaps was observed. The density of all tree species seedlings (except ofCarpinus betulus) was higher under closed canopy than in expanded gaps. The most frequent were seedlings ofAcer pseudoplatanusandAcer platanoideswhich occurred on 80 % and 73 % of the plots under closed canopy, and 75 % and 68 % of the plots in expanded gaps. Seedlings ofQuercus petraeawere not recorded. Density of saplings was higher in expanded gaps than under canopy (except of saplings ofAcer platanoidesandTilia cordata). The density of saplings ofAcer pseudoplatanusandAcer platanoidesincreased with increasing size of expanded gap, whileFraxinus excelsiorsaplings density decreased. There was no significant relationship between density of other species seedlings and saplings and expanded gap size.
Growth under elevated CO2 concentration affects the temperature response of photosynthetic rate
Authors: Holišová P. , Šigut L. , Klem K. , Urban O.
Published: June 2013

In this study, we tested the hypothesis that an elevated CO2concentration leads to a shift of the temperature optimum of the photosynthetic rate in trees. Since the elevated CO2treatment usually leads to a significant decrease in stomatal conductance and consequently to decrease in transpiration followed by an increase in leaf temperature, we hypothesized that elevated CO2results in the acclimation of photosynthetic apparatus to the higher temperature.

We studied the two most common species in the Czech Republic – European beech (Fagus sylvaticaL.) and Norway spruce (Picea abies(L.) Karsten). The eight-year-old trees were grown in glass domes at the experimental research site Bílý Kříž in the Beskydy Mts. and they were exposed to ambient (AC; 385 µmol CO2mol-1) and elevated CO2concentrations (EC; 700 µmol CO2mol-1). Based on the gas-exchange and fluorescence techniques we determined the basic photosynthetic characteristics in the range of leaf temperatures from 10 to 45 °C. The changes in temperature acclimation of tree species studied were evaluated on the basis of the shift of temperature optima.

EC treatment led indeed to an increase of leaf temperature up to 3.5 °C in both species studied. The temperature optimum of the light-saturated rate of CO2assimilation, measured at the growth CO2concentration (i.e. 385 for AC and 700 µmol CO2mol-1for EC trees), was higher by 3 °C in both tree species of the EC variant. Although the shift in photosynthetic temperature optimum disappeared when the AC plants were exposed to an elevated CO2concentration, an acclimation of Rubisco carboxylation and electron transport to higher temperature was observed.
Statistical evaluation of ozone concentrations on open plots in a submountain beech ecosystem in the Western Carpathians Mts.
Authors: Kellerová Daniela , Janík Rastislav
Published: June 2013

The research was conducted on two plots without forest cover situated in the Štiavnické vrchy (A) Mts and in the Kremnické vrchy (B) Mts (Western Carpathian region) and a plot covered with several-year-old naturally regenerated beech stand (C) in the Kremnické vrchy Mts. The highest average value of 71 µg m-3 was recorded in 2007 for all plots; the lowest one was 45 µg m-3 recorded in 2009. Maximum values of ground level ozone concentrations ranging from 124 to 144 µg m-3 were recorded in spring 2008 on all study plots. The values were displaying fairly high variability over the whore research period, with minima in years 2007 and 2008 on the plot covered with forest stand at the time. Statistically significant differences were distinct especially between the years 2007 and 2009.
Monoidal transforms and invariants of singularities in positive characteristic
Authors: Benito Angélica , Villamayor U. Orlando E.
Published: June 2013

The problem of resolution of singularities in positive characteristic can be reformulated as follows: fix a hypersurface$X$, embedded in a smooth scheme, with points of multiplicity at most$n$. Let an$n$-sequence of transformations of$X$be a finite composition of monoidal transformations with centers included in the$n$-fold points of$X$, and of its successive strict transforms. The open problem (in positive characteristic) is to prove that there is an$n$-sequence such that the final strict transform of$X$has no points of multiplicity$n$(no$n$-fold points). In characteristic zero, such an$n$-sequence is defined in two steps. The first consists of the transformation of$X$to a hypersurface with$n$-fold points in the so-calledmonomial case. The second step consists of the elimination of these$n$-fold points (in the monomial case), which is achieved by a simple combinatorial procedure for choices of centers. The invariants treated in this work allow us to present a notion ofstrong monomial casewhich parallels that of monomial case in characteristic zero: if a hypersurface is within the strong monomial case we prove that a resolution can be achieved in a combinatorial manner.
Limit transition between hypergeometric functions of type BC and type A
Authors: Rösler Margit , Koornwinder Tom , Voit Michael
Published: June 2013

Let ${F}_{BC} (\lambda , k; t)$ be the Heckman–Opdam hypergeometric function of type BC with multiplicities $k= ({k}_{1} , {k}_{2} , {k}_{3} )$ and weighted half-sum $\rho (k)$ of positive roots. We prove that ${F}_{BC} (\lambda + \rho (k), k; t)$ converges as ${k}_{1} + {k}_{2} \rightarrow \infty $ and ${k}_{1} / {k}_{2} \rightarrow \infty $ to a function of type A for $t\in { \mathbb{R} }^{n} $ and $\lambda \in { \mathbb{C} }^{n} $. This limit is obtained from a corresponding result for Jacobi polynomials of type BC, which is proven for a slightly more general limit behavior of the multiplicities, using an explicit representation of Jacobi polynomials in terms of Jack polynomials. Our limits include limit transitions for the spherical functions of non-compact Grassmann manifolds over one of the fields $ \mathbb{F} = \mathbb{R} , \mathbb{C} , \mathbb{H} $ when the rank is fixed and the dimension tends to infinity. The limit functions turn out to be exactly the spherical functions of the corresponding infinite-dimensional Grassmann manifold in the sense of Olshanski.
On the Relations Between Audio Features and Room Acoustic Parameters of Auralizations
Authors: Cerdá Salvador , Giménez Alicia , Montell Radha , Barba Arturo , Lacatis Radu , Segura Jaume , Cibrián Rosa M.
Published: June 2013

The usual parameters in room acoustics are used to quantify the acoustic characteristics of rooms and their relation to the subjective perception of transmitted signals. Audio features (calculated with MIRToolbox) have been designed to study the relationships between the characteristics of musical audio files and their subjective perception. Both musical characteristics and acoustic parameters are oriented towards acoustic perception. By using auralizations with calibrated models of auditoriums and tools from the MIRtoolbox it is possible to jointly work with the calculation of audio features and room parameters. In this work, the statistical correlations between C80, STI, D50, EDT, RT and certain audio features have been analyzed. The Pearson r values are higher than 0.8 in all cases. These high correlations enable acoustic parameters to be calculated from the musical characteristics of auralized audio signals.
On the Accuracy of a Four-Node Delaminated Composite Plate Element and Its Application to Damage Detection
Authors: Casanova Cesar F. , Gallego A. , Lázaro M.
Published: June 2013

This paper presents a new four-node composite element, which incorporates nd delaminations through its thickness. Based on the extended finite element method (X-FEM) technology, the element is particularized on a CLT (classical laminate theory). Delamination is considered in the kinematic equations with additional degrees of freedom. The result is a four-node quadrilateral element requiring only two single FEM (finite element method) formulations, a bending one and a membrane one. An important result is that this formulation has the same accuracy as when separate elements are considered (“four region approach”). It is furthermore proven that the delaminated element passes the “patch test” if the selected FEM formulations to build the element pass the test in the pure single problems, making this methodology very attractive to develop other fractured elements. To illustrate this result, two benchmark problems were studied: first a complete delaminated cantilever plate, and second a complete delaminated circular plate. The element was tested in the context of SHM (structural health monitoring). Frequency shifts, damage indexes, and changes in mode shapes and frequency response functions (FRF) were obtained to quantify the severity of damage due to delamination.
Analytical Evaluation of the Acoustic Behavior of Multilayer Walls When Subjected to Three-Dimensional and Moving 2.5-Dimensional Loads
Authors: Tadeu A. , António J. , Godinho L.
Published: June 2013

This paper focuses on the analytical evaluation of the acoustic behavior of multilayer walls when subjected to 3D and moving 2.5D loads. The computations are performed in the frequency domain for a wall system composed of multiple solid and fluid layers. The pressure generated by the 3D load is computed as Bessel integrals, following the transformations proposed by Sommerfeld. The integrals are discretized by assuming the existence of a set of virtual loads equally spaced in a direction perpendicular to the plane of the wall. The expressions presented here allow the pressure field to be computed without discretizing the interfaces between layers. The full interaction between the fluid (air) and the solid layers is taken into account. As the 3D pressure field can also be computed as a summation of spatially sinusoidal harmonic line loads, which can be seen as a moving 2.5D load, this paper studies the contribution made to the global 3D response by the insulation provided by the wall when subjected to each of these loads. To illustrate the main findings, simulated responses are computed in the frequency domains for single and double walls that are subjected to 3D and moving 2.5D loads. Additionally, time responses have been synthesized using inverse Fourier transformations.
Directional Order Tracking in Rotating Machines
Authors: Bucher Izhak
Published: June 2013

This paper describes a computationally simple method to isolate transient vibration from rotating components whose frequency is tightly linked to rotation and to modes of vibration. The results can be viewed as an enhancement of computed order tracking or amplitude demodulation of multiple crossing frequency terms. By measuring the response with an array of sensors, one can compute the relative, instantaneous phase between different sensors and thus obtain information about the spatial behavior of different components with different wavelengths, frequencies, and traveling directions. An array of sensors would thus exploit spatial information to separate different vibration modes and thus gain deeper insight into the dynamical behavior. The proposed method is suitable for whirling shafts and rotating disk-like structures. It is computationally simple and fast while providing better separation of components than single sensor based approaches, in particular when ordinary methods fail to separate close frequencies. It is demonstrated that through the exploitation of cyclic symmetry of rotating structures and the angular periodicity of the vibration modes, the spectral contents of different modes can be separated. Simulated and measured data demonstrate the merits of the proposed algorithm.
Vibration Analysis of the Flexible Connecting Rod With the Breathing Crack in a Slider-Crank Mechanism
Authors: Shih Yan-Shin , Chung Chen-Yuan
Published: June 2013

This paper investigates the dynamic response of the cracked and flexible connecting rod in a slider-crank mechanism. Using Euler–Bernoulli beam theory to model the connecting rod without a crack, the governing equation and boundary conditions of the rod's transverse vibration are derived through Hamilton's principle. The moving boundary constraint of the joint between the connecting rod and the slider is considered. After transforming variables and applying the Galerkin method, the governing equation without a crack is reduced to a time-dependent differential equation. After this, the stiffness without a crack is replaced by the stiffness with a crack in the equation. Then, the Runge–Kutta numerical method is applied to solve the transient amplitude of the cracked connecting rod. In addition, the breathing crack model is applied to discuss the behavior of vibration. The influence of cracks with different crack depths on natural frequencies and amplitudes is also discussed. The results of the proposed method agree with the experimental and numerical results available in the literature.
Damage Detection in Fiber-Reinforced Composite Beams by Using a Bayesian Fusion Method
Authors: Baneen U. , Guivant J. E.
Published: June 2013

This paper presents a method for the detection of damage present in composite beam-type structures. The method, which successfully detected damage in steel beams, is applied to a glass fiber-reinforced beam in order to verify its suitability for composite structures as well. The damage indices were obtained using the gapped-smoothing method (GSM), which does not require a baseline model in order to detect damage. Despite the advantage of avoiding the need for a reference model altogether, unavoidable measurement errors make GSM rather ineffective. The proposed method uses the damage indices that GSM provides for synthesizing a set of likelihood functions that is processed under a Bayesian approach in order to reduce the effect of the noise and other uncertainty sources. The quality of the damage detection was examined by investigating an optimal sampling size analytically, and it was demonstrated through numerical simulation. This paper details the theory of the noise suppression method based on Bayesian data fusion, includes an analysis of the optimal sampling size, and presents the experimental results for two glass fiber-reinforced composite beams with a narrow and wide delamination, respectively. A noise-addition process was applied to the simulated data considering two different noise distributions. The composite beam was modeled in ANSYS, and harmonic analysis was used to obtain the frequency response functions at different beam locations. The results were obtained by adding 5, 10, and 15% noise in the simulated data, and they were then validated from the experimental results.
Analytical and Finite Element Modal Analysis of a Hyperelastic Membrane for Micro Air Vehicle Wings
Authors: Chakravarty Uttam Kumar
Published: June 2013

Analytical and finite element models are developed for investigating the modal characteristics of a hyperelastic rubber latex membrane for micro air vehicle wings applications. A radially prestretched membrane specimen is attached to a thin, rigid circular ring and vibrated in vacuum and in air at atmospheric pressure. The natural frequencies of the membrane computed by analytical and finite element models are correlated well. The natural frequencies increase with mode and prestretch level of the membrane but decrease in air from those in vacuum due to the effect of added mass of air. The damping is low and has a very minimal effect on the frequencies but helps to reduce the amplitude of vibration. Aerodynamic pressure at different angles of attack and a freestream velocity is computed from the wind tunnel test data, and a finite element model is developed for investigating the effect of the aerodynamic pressure on the modal characteristics of the membrane. It is found that the effect of aerodynamic pressure on the natural frequencies of the membrane is not significant.
Load Recovery in Components Based on Dynamic Strain Measurements
Authors: Dhingra Anoop K. , Hunter Timothy G. , Gupta Deepak K.
Published: June 2013

This paper presents a modeling approach for estimating time varying loads acting on a component from experimental strain measurements. The strain response of an elastic vibrating system is written as a linear superposition of strain modes. Since the strain modes, as well as the normal displacement modes, are intrinsic dynamic characteristics of a component, the dynamic loads exciting a component are estimated by measuring induced strain fields. The accuracy of the estimated loads depends on a number of factors, such as the placement locations and orientations of the gauges on the instrumented structure, as well as the number of retained modes from strain modal analysis. A solution procedure based on the construction of D-optimal designs is implemented to determine the optimum locations and orientations of strain gauges such that the variance in load estimates is minimized. A numerical as well as an experimental validation of the proposed approach through two example problems is also presented.
Design of Acoustic Metamaterial Devices Based on Inverse Method
Authors: Jing Yang Jing , Huang Ming , Hui Cai Guang , Sheng Xie Ru , Yang Jie
Published: June 2013

The inverse method based on the numerical solution of Laplace's equation is introduced for the design of acoustic metamaterial devices. An arbitrary shaped acoustic concentrator and an external cloak are designed numerically and validated by full wave simulation. Besides, an acoustic reciprocal cloak and a field rotator are proposed. Compared with the analytical method, the inverse method is much more universal, and arbitrary shaped acoustic metamaterial devices can be flexibly designed without any knowledge of the transformation equations.