bluuebunny/crossref_metadata_2025 huggingface dataset:
Baroreceptor afferents modulate brain excitation and influence susceptibility to toxic effects of hyperbaric oxygen
Authors: Demchenko Ivan T. , Gasier Heath G. , Zhilyaev Sergei Yu , Moskvin Alexander N. , Krivchenko Alexander I. , Piantadosi Claude A. , Allen Barry W.
Published: July 2014

Unexplained adjustments in baroreflex sensitivity occur in conjunction with exposures to potentially toxic levels of hyperbaric oxygen. To investigate this, we monitored central nervous system, autonomic and cardiovascular responses in conscious and anesthetized rats exposed to hyperbaric oxygen at 5 and 6 atmospheres absolute, respectively. We observed two contrasting phases associated with time-dependent alterations in the functional state of the arterial baroreflex. The first phase, which conferred protection against potentially neurotoxic doses of oxygen, was concurrent with an increase in baroreflex sensitivity and included decreases in cerebral blood flow, heart rate, cardiac output, and sympathetic drive. The second phase was characterized by baroreflex impairment, cerebral hyperemia, spiking on the electroencephalogram, increased sympathetic drive, parasympatholysis, and pulmonary injury. Complete arterial baroreceptor deafferentation abolished the initial protective response, whereas electrical stimulation of intact arterial baroreceptor afferents prolonged it. We concluded that increased afferent traffic attributable to arterial baroreflex activation delays the development of excessive central excitation and seizures. Baroreflex inactivation or impairment removes this protection, and seizures may follow. Finally, electrical stimulation of intact baroreceptor afferents extends the normal delay in seizure development. These findings reveal that the autonomic nervous system is a powerful determinant of susceptibility to sympathetic hyperactivation and seizures in hyperbaric oxygen and the ensuing neurogenic pulmonary injury.
Ventilation/perfusion mismatch during lung aeration at birth
Authors: Lang Justin A. R. , Pearson James T. , te Pas Arjan B. , Wallace Megan J. , Siew Melissa L. , Kitchen Marcus J. , Fouras Andreas , Lewis Robert A. , Wheeler Kevin I. , Polglase Graeme R. , Shirai Mikiyasu , Sonobe Takashi , Hooper Stuart B.
Published: July 2014

At birth, the transition to newborn life is triggered by lung aeration, which stimulates a large increase in pulmonary blood flow (PBF). Current theories predict that the increase in PBF is spatially related to ventilated lung regions as they aerate after birth. Using simultaneous phase-contrast X-ray imaging and angiography we investigated the spatial relationships between lung aeration and the increase in PBF after birth. Six near-term (30-day gestation) rabbits were delivered by caesarean section, intubated and an intravenous catheter inserted, before they were positioned for X-ray imaging. During imaging, iodine was injected before ventilation onset, after ventilation of the right lung only, and after ventilation of both lungs. Unilateral ventilation increased iodine levels entering both left and right pulmonary arteries (PAs) and significantly increased heart rate, iodine ejection per beat, diameters of both left and right PAs, and number of visible vessels in both lungs. Within the 6th intercostal space, the mean gray level (relative measure of iodine level) increased from 68.3 ± 11.6 and 70.3 ± 7.5%·s to 136.3 ± 22.6 and 136.3 ± 23.7%·s in the left and right PAs, respectively. No differences were observed between vessels in the left and right lungs, despite the left lung not initially being ventilated. The increase in PBF at birth is not spatially related to lung aeration allowing a large ventilation/perfusion mismatch, or pulmonary shunting, to occur in the partially aerated lung at birth.
Immediate Utility of Two Approved Agents to Target Both the Metabolic Mevalonate Pathway and Its Restorative Feedback Loop
Authors: Pandyra Aleksandra , Mullen Peter J. , Kalkat Manpreet , Yu Rosemary , Pong Janice T. , Li Zhihua , Trudel Suzanne , Lang Karl S. , Minden Mark D. , Schimmer Aaron D. , Penn Linda Z.
Published: July 2014

New therapies are urgently needed for hematologic malignancies, especially in patients with relapsed acute myelogenous leukemia (AML) and multiple myeloma. We and others have previously shown that FDA-approved statins, which are used to control hypercholesterolemia and target the mevalonate pathway (MVA), can trigger tumor-selective apoptosis. Our goal was to identify other FDA-approved drugs that synergize with statins to further enhance the anticancer activity of statins in vivo. Using a screen composed of other FDA approved drugs, we identified dipyridamole, used for the prevention of cerebral ischemia, as a potentiator of statin anticancer activity. The statin–dipyridamole combination was synergistic and induced apoptosis in multiple myeloma and AML cell lines and primary patient samples, whereas normal peripheral blood mononuclear cells were not affected. This novel combination also decreased tumor growth in vivo. Statins block HMG-CoA reductase (HMGCR), the rate-limiting enzyme of the MVA pathway. Dipyridamole blunted the feedback response, which upregulates HMGCR and HMG-CoA synthase 1 (HMGCS1) following statin treatment. We further show that dipyridamole inhibited the cleavage of the transcription factor required for this feedback regulation, sterol regulatory element–binding transcription factor 2 (SREBF2, SREBP2). Simultaneously targeting the MVA pathway and its restorative feedback loop is preclinically effective against hematologic malignancies. This work provides strong evidence for the immediate evaluation of this novel combination of FDA-approved drugs in clinical trials. Cancer Res; 74(17); 4772–82. ©2014 AACR.
Gene–Environment Interaction Involving Recently Identified Colorectal Cancer Susceptibility Loci
Authors: Kantor Elizabeth D. , Hutter Carolyn M. , Minnier Jessica , Berndt Sonja I. , Brenner Hermann , Caan Bette J. , Campbell Peter T. , Carlson Christopher S. , Casey Graham , Chan Andrew T. , Chang-Claude Jenny , Chanock Stephen J. , Cotterchio Michelle , Du Mengmeng , Duggan David , Fuchs Charles S. , Giovannucci Edward L. , Gong Jian , Harrison Tabitha A. , Hayes Richard B. , Henderson Brian E. , Hoffmeister Michael , Hopper John L. , Jenkins Mark A. , Jiao Shuo , Kolonel Laurence N. , Le Marchand Loic , Lemire Mathieu , Ma Jing , Newcomb Polly A. , Ochs-Balcom Heather M. , Pflugeisen Bethann M. , Potter John D. , Rudolph Anja , Schoen Robert E. , Seminara Daniela , Slattery Martha L. , Stelling Deanna L. , Thomas Fridtjof , Thornquist Mark , Ulrich Cornelia M. , Warnick Greg S. , Zanke Brent W. , Peters Ulrike , Hsu Li , White Emily
Published: July 2014

Background: Genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) that are associated with risk of colorectal cancer. Prior research has evaluated the presence of gene–environment interaction involving the first 10 identified susceptibility loci, but little work has been conducted on interaction involving SNPs at recently identified susceptibility loci, including: rs10911251, rs6691170, rs6687758, rs11903757, rs10936599, rs647161, rs1321311, rs719725, rs1665650, rs3824999, rs7136702, rs11169552, rs59336, rs3217810, rs4925386, and rs2423279.

Methods: Data on 9,160 cases and 9,280 controls from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and Colon Cancer Family Registry (CCFR) were used to evaluate the presence of interaction involving the above-listed SNPs and sex, body mass index (BMI), alcohol consumption, smoking, aspirin use, postmenopausal hormone (PMH) use, as well as intake of dietary calcium, dietary fiber, dietary folate, red meat, processed meat, fruit, and vegetables. Interaction was evaluated using a fixed effects meta-analysis of an efficient Empirical Bayes estimator, and permutation was used to account for multiple comparisons.

Results: None of the permutation-adjusted P values reached statistical significance.

Conclusions: The associations between recently identified genetic susceptibility loci and colorectal cancer are not strongly modified by sex, BMI, alcohol, smoking, aspirin, PMH use, and various dietary factors.

Impact: Results suggest no evidence of strong gene–environment interactions involving the recently identified 16 susceptibility loci for colorectal cancer taken one at a time. Cancer Epidemiol Biomarkers Prev; 23(9); 1824–33. ©2014 AACR.
Activating FGFR2–RAS–BRAF Mutations in Ameloblastoma
Authors: Brown Noah A. , Rolland Delphine , McHugh Jonathan B. , Weigelin Helmut C. , Zhao Lili , Lim Megan S. , Elenitoba-Johnson Kojo S.J. , Betz Bryan L.
Published: July 2014

Purpose: Ameloblastoma is an odontogenic neoplasm whose overall mutational landscape has not been well characterized. We sought to characterize pathogenic mutations in ameloblastoma and their clinical and functional significance with an emphasis on the mitogen-activated protein kinase (MAPK) pathway.

Experimental Design: A total of 84 ameloblastomas and 40 non-ameloblastoma odontogenic tumors were evaluated with a combination of BRAF V600E allele–specific PCR, VE1 immunohistochemistry, the Ion AmpliSeq Cancer Hotspot Panel, and Sanger sequencing. Efficacy of a BRAF inhibitor was evaluated in an ameloblastoma-derived cell line.

Results: Somatic, activating, and mutually exclusive RAS–BRAF and FGFR2 mutations were identified in 88% of cases. Somatic mutations in SMO, CTNNB1, PIK3CA, and SMARCB1 were also identified. BRAF V600E was the most common mutation, found in 62% of ameloblastomas and in ameloblastic fibromas/fibrodentinomas but not in other odontogenic tumors. This mutation was associated with a younger age of onset, whereas BRAF wild-type cases arose more frequently in the maxilla and showed earlier recurrences. One hundred percent concordance was observed between VE1 immunohistochemistry and molecular detection of BRAF V600E mutations. Ameloblastoma cells demonstrated constitutive MAPK pathway activation in vitro. Proliferation and MAPK activation were potently inhibited by the BRAF inhibitor vemurafenib.

Conclusions: Our findings suggest that activating FGFR2–RAS–BRAF mutations play a critical role in the pathogenesis of most cases of ameloblastoma. Somatic mutations in SMO, CTNNB1, PIK3CA, and SMARCB1 may function as secondary mutations. BRAF V600E mutations have both diagnostic and prognostic implications. In vitro response of ameloblastoma to a BRAF inhibitor suggests a potential role for targeted therapy. Clin Cancer Res; 20(21); 5517–26. ©2014 AACR.
Selenium and Prostate Cancer Prevention: What Next—If Anything?
Authors: Christensen Merrill J.
Published: July 2014

Chemopreventive effects of the essential trace element selenium against prostate cancer have been shown in preclinical models and human observational studies, but results from clinical trials have been disappointing. It appears that there is a threshold selenium (Se) status below which improvement will decrease prostate cancer risk, but above which supplemental Se may be deleterious. Different forms of selenium have different effects, and genetic and other factors modify selenium's chemopreventive potential. Identification of men most likely to benefit from Se status improvement could have significant public health benefits. Cancer Prev Res; 7(8); 781–5. ©2014 AACR.
Effect of an Isoenergetic Traditional Mediterranean Diet on the High-Density Lipoprotein Proteome in Men with the Metabolic Syndrome
Authors: Richard Caroline , Couture Patrick , Desroches Sophie , Nehmé Benjamin , Bourassa Sylvie , Droit Arnaud , Lamarche Benoît
Published: July 2014

Background/Aims: The objective of this preliminary study was to examine the impact of the Mediterranean diet (MedDiet) on the high-density lipoprotein (HDL) proteome in men with the metabolic syndrome (MetS). Methods: Twenty-six men with the MetS first consumed a standardized baseline North American isoenergetic control diet (5 weeks) and then consumed an isoenergetic MedDiet (5 weeks), both in full feeding condition. The HDL fraction was isolated by ultracentrifugation at the end of each diet and the HDL proteome assessed by isobaric tags for relative and absolute quantitation and mass spectrometry. Results: Of all proteins identified within HDL, only 3 showed significant changes in relative abundance after the MedDiet versus the control diet, including a reduction in inflammation-related inter-α-trypsin inhibitor heavy chain H4 (fold change: 0.62) and hemoglobin subunits α (fold change: 0.40) and β (fold change: 0.46). Other HDL-bound proteins associated with functions related to lipid metabolism/cholesterol homeostasis, oxidation, coagulation, complement activation and immunity were unchanged after consumption of the MedDiet for 5 weeks. Conclusions: Changes in the HDL proteome may explain, at least partly, the well-known anti-inflammatory effect ascribed to the MedDiet. Otherwise, short-term consumption of the MedDiet seems to have little impact on other features of the HDL proteome in men with the MetS.
Effects of Short-Term Continuous Positive Airway Pressure on Myocardial Sympathetic Nerve Function and Energetics in Patients With Heart Failure and Obstructive Sleep Apnea
Authors: Hall Allison B. , Ziadi Maria C. , Leech Judith A. , Chen Shin-Yee , Burwash Ian G. , Renaud Jennifer , deKemp Robert A. , Haddad Haissam , Mielniczuk Lisa M. , Yoshinaga Keiichiro , Guo Ann , Chen Li , Walter Olga , Garrard Linda , DaSilva Jean N. , Floras John S. , Beanlands Rob S.B.
Published: July 2014

Background—

Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function. We hypothesized that short-term (6–8 weeks) CPAP in patients with OSA and heart failure with reduced ejection fraction would improve myocardial sympathetic nerve function and energetics.

Methods and Results—

Forty-five patients with OSA and heart failure with reduced ejection fraction (left ventricular ejection fraction 35.8±9.7% [mean±SD]) were evaluated with the use of echocardiography and
11
C-acetate and
11
C-hydroxyephedrine positron emission tomography before and ≈6 to 8 weeks after randomization to receive short-term CPAP (n=22) or no CPAP (n=23). Work metabolic index, an estimate of myocardial efficiency, was calculated as follows: (stroke volume index×heart rate×systolic blood pressure÷K
mono
), where K
mono
is the monoexponential function fit to the myocardial
11
C-acetate time-activity data, reflecting oxidative metabolism. Presynaptic sympathetic nerve function was measured with the use of the
11
C-hydroxyephedrine retention index. CPAP significantly increased hydroxyephedrine retention versus no CPAP (Δretention: +0.012 [0.002, 0.021] versus −0.006 [−0.013, 0.005] min
−1
;
P
=0.003). There was no significant change in work metabolic index between groups. However, in those with more severe OSA (apnea-hypopnea index >20 events per hour), CPAP significantly increased both work metabolic index and systolic blood pressure (
P
<0.05).

Conclusions—

In patients with heart failure with reduced ejection fraction and OSA, short-term CPAP increased hydroxyephedrine retention, indicating improved myocardial sympathetic nerve function, but overall did not affect energetics. In those with more severe OSA, CPAP may improve cardiac efficiency. Further outcome-based investigation of the consequences of CPAP is warranted.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00756366.
Establishment of Government-Initiated Comprehensive Stroke Centers for Acute Ischemic Stroke Management in South Korea
Authors: Kim Jei , Hwang Yang-Ha , Kim Joon-Tae , Choi Nack-Cheon , Kang Sa-Yoon , Cha Jae-Kwan , Ha Yeon Soo , Shin Dong-Ick , Kim Seongheon , Lim Byeong-Hoon
Published: July 2014

Background and Purpose—

In 2008, the Ministry of Health and Welfare of South Korea initiated the Regional Comprehensive Stroke Center (CSC) program to decrease the incidence and mortality of stroke nationwide. We evaluated the performance of acute ischemic stroke management after the Regional CSC program was introduced.

Methods—

The Ministry of Health and Welfare established 9 Regional CSCs in different provinces from 2008 to 2010. All Regional CSCs have been able to execute the critical processes independently for stroke management since 2011. The Ministry of Health and Welfare was responsible for program development and financial support, the Regional CSC for program execution, and the Korea Centers for Disease Control and Prevention for auditing the execution. We analyzed prospectively collected data on the required indices from 2011 and repeated the analysis the following year for comparison.

Results—

After the Regional CSCs were established, the first brain image was taken within 1 hour from arrival at the emergency room for all patients with stroke; the length of hospital stay decreased from 14 to 12 days; for the rapid execution of thrombolysis, the first brain image was taken within 12 minutes; intravenous and intra-arterial thrombolysis were started within 40 and 110 minutes, respectively, after emergency room arrival; and the hospital stay of thrombolytic patients decreased from 19 to 15 days.

Conclusions—

The Regional CSC program has improved the performance of acute stroke management in South Korea and can be used as a model for rapidly improving stroke management.
Redirected aggression reduces the cost for victims in semi-provisioned free-ranging Japanese macaques (Macaca fuscata fuscata)
Authors: Tokuyama Nahoko , Furuichi Takeshi
Published: July 2014

In many social species, the victim often attacks an uninvolved third individual soon after a conflict. This behaviour is called ‘redirected aggression’ or ‘redirection’, and its role(s) remain(s) controversial. We observed semi-provisioned free-ranging Japanese macaques at Iwatayama Monkey Park in Arashiyama, Kyoto, Japan, to test three hypotheses concerning the function of redirected aggression: Japanese macaques perform redirection to (1) indirectly retaliate against the aggressor, (2) reduce post-conflict stress, or (3) reduce post-conflict uncertainty. When we observed aggressive interactions, we recorded the behaviour of victims during the subsequent 10 min. Redirection occurred more frequently when the rank of the victim of the initial conflict was high, when the victim was an older monkey, and when conflicts occurred among kin. The results largely supported hypothesis 3. Victims received renewed aggression not only from the initial aggressor but also from bystanders more frequently within 1 min after the initial conflict than in the subsequent 9 min. Victims who performed redirection received less aggression from bystanders. Victims might have been able to avoid renewed aggression because they could change their state from victim to aggressor by performing redirection. This effect of redirection did not differ with the victim’s rank. However, the lower the victim’s rank, the higher the risk that they would receive retaliation from the target of the redirected aggression or the latter’s kin. Thus, redirection caused the same magnitude of benefit and a different magnitude of risk according to the victim’s rank. The victim may need to judge his/her own situation when making the decision as to whether to perform redirection.
Competition and cuckoldry: estimating fitness of alternative reproductive tactics in plainfin midshipman
Authors: Cogliati Karen M. , Balshine Sigal , Neff Bryan D.
Published: July 2014

There has been much debate about how male alternative reproductive tactics (ARTs) evolve. In particular, researchers question whether ARTs have evolved as a conditional, ‘best of a bad job’ strategy where one tactic has higher fitness than the other, or whether they have evolved as a result of a genetic polymorphism where both tactics have equal fitness. Despite the large number of species known to have ARTs, tests of equal fitness between tactics have only been conducted in a handful of species. We tested the prediction of equal fitness using the plainfin midshipman (Porichthys notatus), a species with two well characterized male ARTs: guarding type I males and cuckolding type II males. We collected data across three years and three sampling locations to determine the proportion of each reproductive tactic, as well as the proportion of offspring sired by each male type using microsatellite markers. Our analysis suggests that males adopting the conventional guarding tactic likely have higher fitness compared to males adopting the cuckolder type II tactic. Also, we show that the guarding male tactic is able to gain paternity through cuckoldry, and that these males, who sometimes guard and sometimes cuckold, are responsible for the majority of paternity lost within nests. Indeed, the classic cuckolding type II males were responsible for only a small fraction of the paternity lost. These results highlight the degree of flexibility in male behaviour even among individuals adopting the same male tactic. Taken together, our results provide the first exploration of the evolution of male ARTs in plainfin midshipman and, given the tractability of midshipman system, a valuable next step will be to look for gene-by-environment interactions on tactic development and expression.
The Role of the Parietal Cortex in Multisensory and Response Integration: Evidence from Transcranial Direct Current Stimulation (tDCS)
Authors: Zmigrod Sharon
Published: July 2014

The question of how the brain forms unified representations from multisensory data that are processed in distinct cortical regions is known in the literature as ‘the binding problem’. In the last decade, several studies have suggested possible neural mechanisms and brain regions that might be involved in integration processes. One of the brain regions that is implicated with multisensory perception is the posterior parietal cortex (PPC). Evidence from patients with parietal lesions suggests the involvement of the PPC in coherent perception. Here, we investigated the role of the PPC in multisensory feature integration through experimental manipulation of non-invasive brain stimulation with healthy participants using transcranial direct current stimulation (tDCS). In different sessions, healthy participants received anodal, cathodal, or sham stimulation (2 mA, 20 min) over the right PPC while performing an audio-visual event-file task. The results underscore two interesting observations. Firstly, there was a significant difference in integration effects between features from different modalities in the anodal stimulation compared to sham, suggesting interference of the multisensory integration processes during the brain stimulation. And secondly, after anodal stimulation, the unattended feature became more likely to be integrated with the response feature compared to the other conditions, presumably through an interference of attentional processes. Hence, these findings emphasize the role of the right PPC in multisensory integration. Furthermore, from a methodological perspective, tDCS can be used as an experimental tool by creating a temporary, reversible disruption in cognitive processes in order to explore the mechanisms underlying cognitive functions.
Perception of Tactile Graphics: Embossings Versus Cutouts
Authors: Kalia Amy , Hopkins Rose , Jin David , Yazzolino Lindsay , Verma Svena , Merabet Lotfi , Phillips Flip , Sinha Pawan
Published: July 2014

Graphical information, such as illustrations, graphs, and diagrams, are an essential complement to text for conveying knowledge about the world. Although graphics can be communicated well via the visual modality, conveying this information via touch has proven to be challenging. The lack of easily comprehensible tactile graphics poses a problem for the blind. In this paper, we advance a hypothesis for the limited effectiveness of tactile graphics. The hypothesis contends that conventional graphics that rely upon embossings on two-dimensional surfaces do not allow the deployment of tactile exploratory procedures that are crucial for assessing global shape. Besides potentially accounting for some of the shortcomings of current approaches, this hypothesis also serves a prescriptive purpose by suggesting a different strategy for conveying graphical information via touch, one based on cutouts. We describe experiments demonstrating the greater effectiveness of this approach for conveying shape and identity information. These results hold the potential for creating more comprehensible tactile drawings for the visually impaired while also providing insights into shape estimation processes in the tactile modality.
Cupressinoxylon Jiayinense, A New Species Of The Late Cretaceous From Heilongjiang Province, China
Authors: Ru-feng Wang , Yu-fe Wang , Yong-zhe Chen
Published: July 2014

Cupressinoxylon jiayinense spec. nov., a new species of silicified coniferous wood, is described from the Late Cretaceous in Jiayin County, Heilongjiang Province, Northeast China. The growth rings are distinct. The transition from earlywood to latewood is gradual. Rays range from 1- to 2-seriate, and are 4-68 cells high. Both horizontal and tangential walls of ray cells are smooth. The cross-field pitting is cupressoid. There are 2 or 3 pits per cross field. Ray tracheids are rarely present. Wood parenchyma is abundant and diffuse. Resin canals are absent. These features indicate affinities with Cupressaceae, specifically with some members of the extant genus Cupressus.
Three-Dimensional Imaging and Analysis of Differentiating Secondary Xylem by Confocal Microscopy
Authors: Kitin Peter , Sano Yuzou , Funada Ryo
Published: July 2014

We examined the three-dimensional (3-D) structure of differentiating xylem in a hardwood tree, Kalopanax pictus, by confocallaser scanning microscopy (CLSM) using relatively thick, hand-cut histological sections. 3-D studies of plant tissues by mechanical serial sectioning with a microtome are very time-con suming. By contrast, the preparation of samples for CLSM is easier and the 3-D structure of intact tissue is preserved during optical sectioning. We obtained extended-focus images of the surface of specimens and these images resembled the stereographic images obtained by scanning electron microscopy. In addition , we observed radial files of cambial derivative cells at various stages of differenti ation and the internal structure along the 'z' axis of specimens on serial optical sections. We analysed the developmental changes in the morphology of cambial derivat ive cells, for example, the 3-D shape and arrangement of cells, the readjustment of the position of cells, and the development of secondary walls, pits and perforation plates. Our results showed that the arrangement of the differentiating xylem cells mirror s that of the cambial cell s. Deviations from the longitudinal orientation of vessel elements were specified by similar patterns of orientation of fusiform and ray cambial cells. The development of vessel elements progressed more rapidly than that of other xylem elements. When secondary walls with bordered pits and perforation plates with membranes were present in vessel elements and their expansion ceased, no secondary wall formation was detected in adjacent ray cells. The delay in secondary wall formation by the ray parenchyma cells, as compared to that by vessel elements, might facilitate the readju stment of the position of cells in the developing xylem tissue that is a consequence of the considerable expan sion of the vessel elements.
Imaging the Mechanical Properties of Wood Cell Wall Layers by Atomic Force Modulation Microscopy
Authors: Clair Bruno , Arinero Richard , Lévèque Gérard , Ramonda Michel , Thibaut Bernard
Published: July 2014

Atomic Force Microscopy in force modulation mode was used to study the elastic properties of the different fibre wall layers of the tension wood of holm oak and normal wood of boco. The method is based on the measurement of the resonance frequency of the microscope lever in contact with the sampie. This frequency is related to the reduced Young modulus E* = E/(I-v2) of the material, supposed to be isotropie. 'Elastic' images of the cell are obtained simultaneously with the topographie images, which allows the observation of the mechanical properties of the cells at a nanometric scale. Layers G, S1, S2 and ML can clearly be distinguished. By comparison with known materials an estimation of the absolute modulus is given in the range 5-20 GPa, but should be considered with caution, because the inherent anisotropy of the materials has not been taken into account.
High-Frequency Densitometry-A New Method for the Rapid Evaluation of Wood Density Variations
Authors: Schinker Martin G. , Hansen Norbert , Spiecker Heinrich
Published: July 2014

A new method called HF-densitometry is introduced, which measures relative density variations along wood surfaces utilizing the dielectric properties ofwood. The method is based on the propagation of continuous electromagnetic waves in a high-frequency (HF) transmitter-receiver link of an extremely small electrode system, which is in direct contact with the wood surface investigated. The electromagnetic field emitted by the transmitting electrode propagates through a small volume of the wood sampie to the receiving electrode, located very close to the transmitting electrode. The received signal strength is directly influenced by the dielectric properties of the material along the propagation path. The variation of the relative dielectric constant in different wood structures is correlated with the density variations in a way the received signal strength increases with increasing wood density. The dielectric measuring device, developed on the basis of the new method, allows non-destructive, extremely fast measurements of wood density variations . The new HF-densitometry method was compared to X-ray densitometry by performing measurements on an identical spruce sampie.
Analysis of Turee Microscopic Cuaracters for Separating the Wood of Pinus Contorta and P. Ponderosa
Authors: Wiedenhoeft Alex C. , Miller Regis B. , Theim Terra J.
Published: July 2014

Three microscopic characters were evaluated for the identification of Pinus contorta and Pinus ponderosa. The tangential diameter of the resin canals, including the epithelium, was compared to the tangential diameter of the entire resin canal complex. The latter measurement was shown to give diagnostic results for these species. Data from the examination of ray composition do not support previously published methods for separating P. contorta and P. ponderosa. The presence or absence of small elongate crystals in the subsidiary parenchyma of the resin canal complexes was shown to be the most powerful diagnostic character for separating the wood of these species.
The Wood of Pinus Canariensis and Its Resinous Heartwood
Authors: Esteban Luis García , Gasson Peter , Climent José María , de Palacios Paloma , Guindeo Antonio
Published: July 2014

Pinus canariensis (Canary Island Pine or Piteh Pine) forms natural forests on the islands of Tenerife and La Palma. The heartwood has an extraordinarily high resin eontent, and this paper provides an anatomical deseription of the wood as well as an interpretation of the faetors relating to this resinifieation
A Topocuemical and Semiquantitative Study of The Lignification During Ageing of Bamboo Culms (Phyllostachys Viridiglaucescens)
Authors: Lybeer Bieke , Koch Gerald
Published: July 2014

The lignification of Phyllostachys viridiglaucescens (Carr.) Riv. & Riv. during ageing was studied topochemically by means of UV microspectrophotometry. The study revealed that p-coumaric and ferulic acids are widely distributed in P. viridiglaucescens and that their content is dependent on the anatomicallocation and the differentiation phase. The lignin in the epidermal cell wall is deposited early in the development and does not increase with age. This is in contrast with the fibres and the ground parenchyma cells where an increasing trend in lignification during the first year is shown. The early maturing fibres of the vascular bundles reveal a maximum absorbance value at 280 nm (guaiacyl peak) whereas the late maturing fibres displaya shoulder at 310-320 nm in young culms and a guaiacyl peak in older culms. The S2 fibre wall has a lamellar structure with an increasing lignin content from the centre towards the compound middle lamella. The compound middle lamellae show higher absorbance values and are richer in p-coumaric and ferulic acid esters in comparison to the S2 wall layers. The vessel walls have a low lignin content.
Microfibril Angle Prediction of Pinus Taeda Wood Samples Based on Tangential Face Nir Spectra
Authors: Schimleck L.R. , Sussenbach E. , Leaf G. , Jones P.D. , Huang C.L.
Published: July 2014

The use of calibrated near infrared (NIR) spectroscopy for predicting the microfibril angle (MFA) of Pinus taeda L. (loblolly pine) wood samples is described. NIR spectra were collected from the tangential face of earlywood (EW) and latewood (LW) sections cut from eleven P. taeda radial strips. The MFA of these sections was measured using X-ray diffraction. Calibrations for MFA were determined using all samples combined, EW only and LW only. Relationships were good, with coefficients of determination (R2) ranging from 0.86 (EW) to 0.91 (LW). A calibration for MFA based on NIR spectra collected from sections of 8 strips was used to predict the MFA of sections from the remaining 3 strips. Prediction statistics were strong (R2p = 0.81, SEP= 5.2 degrees, RPDp = 2.23) however errors were greater than those reported previously for studies based on NIR spectra collected from the radial-longitudinal face. The results presented in this study demonstrate that it is possible to use tangential face NIR spectra to determine MFA variation for EW and LW within individual growth rings.
Variations of Wood Anatomy and δ13C Within-Tree Rings of Coastal Pinus Pinaster Showing Intra-Annual Density Fluctuations
Authors: De Micco Veronica , Saurer Matthias , Aronne Giovanna , Tognetti Roberto , Cherubini Paolo
Published: July 2014

We investigated the variation of wood anatomical characteristics and carbon isotopic composition of tree rings showing intra-annual density fluctuations (IADFs) in plants of Pinus pinaster Ait. growing at a coastal plantation in Tuscany (Italy). IADFs are regions of the tree ring where wood density changes abruptly due to a sudden change of environmental conditions, particularly of water availability. Dendrochronological analyses allowed dating of the rings and four regions were considered in each tree ring: earlywood, IADF, late-earlywood and latewood. Although IADF commonly has been classified as latewood-like tissue in the literature, we found differences in anatomical characteristics and carbon isotopic composition between tracheids of the two regions. The lumen area of tracheids in IADF was significantly larger than in latewood, while still smaller than in earlywood and late-earlywood. Latewood and IADF had a greater proportion of narrow tracheids than both earlywood and late-earlywood. Although latewood and IADF were characterized by tracheids with lumina lengthened in the tangential direction, while earlywood tracheids were elongated in the radial direction, some differences were found also between latewood and IADF. Moreover, IADF tracheids had a higher 13C/12C ratio than any other region and showed isotopic values significantly different from the latewood. The quantification of anatomical features of tracheids within rings was useful to discriminate between latewood and IADFs, as well as helpful for the identification of tree-ring boundaries. The overall interpretation of dendrochronological, wood anatomical and carbon isotopic data seems to be a promising approach for the dating and the ecological interpretation of tree rings in Mediterranean ecosystems and for gaining climatic information with intra-annual resolution.
The Putative Jurassic Angiosperm Wood Suevioxylon Zonatum Revisited
Authors: Philippe Marc , Gromyko Dmitri
Published: July 2014

As the phylogeny and evolution of angiosperms is being completely rewritten by molecular data, there is renewed interest in the earliest fossil record of the group. A putative Jurassic Angiosperm wood, Suevioxylon zonatum Kräusel is revisited. We reinvestigated the type material (specimen and five thin sections) with light microscopy and SEM. This reappraisal indicates that Suevioxylon zonatum is actually a poorly preserved softwood and not an angiosperm.
WOOD ULTRASTRUCTURE OF ANCIENT BURIED LOGS OF FITZROYA CUPRESSOlDES
Authors: Castro María A. , Roig Fidel A.
Published: July 2014

The anatomy and ultrastructure of subfossil wood of Fitzroya cupressoides from the late Pleistocene (>50,000 14C years before present) were compared with those of extant F. cupressoides trees from southern Chile, using light microscopy (polarized light and ftuorescence), scanning electron microscopy coupled with an energy dispersive X-ray spectroscopy system, and transmission electron microscopy. The ancient wood showed an unchanged gross wood structure, loss of cell wall birefringence, loss of lignin autoftuorescence, and a loss of the original microfibrillar pattern. The energy dispersive X-ray spectroscopy analysis indicated higher than normal contents of S, Cl, and Na in subfossil wood. Ultrastructural modifications in the cell wall of the subfossil wood could have important implications for further studies involving isotopic and wood anatomical measurements of ancient wood.
STRUCTURAL VARIATIONS IN ROOT AND STEM WOOD OF STYRAX (STYRACACEAE) FROM BRAZILIAN FOREST AND CERRADO
Authors: Machado Silvia Rodrigues , Rodella Roberto Antonio , Angyalossy Veronica , Marcati Carmen Regina
Published: July 2014

The genus Styrax L. (Styracaceae) has a wide distribution in Brazil, occurring in diverse ecosystems. To get a better insight into the ecologieal adaptations ofwood strueture, we studied two speeies, S. camporum and S.jerrugineus from the cerrado, and three species, S. latifolium, S. martii and S. leprosus from the Atlantie forest. For each species, the wood of root and stern was analyzed separately and observations inc1uded qualitative as well as quantitative wood characteristics. The results show that there were significant anatomical differences between the forest and cerrado species as well as between the root and stern wood within single species. Quantitatively, the most informative features in the root wood that separated the forest from the cerrado species were diameter, length and number of vessels, length of fibres, and width and frequeney of rays. In the stern wood, length and frequency of vessels, length of fibres, and width and frequency of rays were the most informative features. In contrast to the forest species, which had larger vessel diameters in their stem wood, the cerrado species had larger vessel diameters in their root wood. The ca1culated vulnerability index indicates that all Styrax species have adaptations to mesic conditions. The cerrado species had the smallest index values, which could be related to the seasonally dry condition of this environment.
Variations In Dieot Wood Anatomy: A Global Analysis Based on the Insidewood Database
Authors: Wheeler E.A. , Baas P. , Rodgers S.
Published: July 2014

Information from the Inside Wood database (5,663 descriptions) was used to determine the relative abundance of selected IAWA Hardwood List Features, for the whole world and for the broad geographic regions used in the IAWA List. Features that occur in more than 75 % of the records are: growth ring boundaries indistinct or absent, diffuse porosity, exclusively simple perforation plates, alternate intervessel pitting, and non-septate fibers. The geographic distribution of vessel element features found in this study is consistent with previous studies: ring porosity is a Northern Hemisphere adaptation; numerous, narrow, short vessel elements are more common in temperate regions than in tropical regions. Element size is related to habit, with few wide vessels being a syndrome that is virtually absent from shrubs and small trees. The co-occurrence of selected features, ones that earlier have been suggested to be correlated, was examined; e.g., tangential vessel arrangement and ring porosity, rare axial parenchyma and septate fibers, tracheids and exclusively solitary vessels that are of medium to wide diameter. Axial parenchyma features show geographic variation, with aliform to confluent parenchyma and bands more than 3 cells wide being primarily tropical in occurrence. Storied rays, crystals, and silica bodies are more common in the tropics than in the temperate Northern Hemisphere. For ray features, geographic patterns are less apparent. In Australia, incidences of some features (vestured pits, solitary vessels, radial/diagonal vessel arrangement) are influenced by the Myrtaceae being a major component of the flora. This paper is but a general overview. Information from the Inside Wood database when combined with detailed information on ecological and geographical distributions of species, and subjected to more robust statistical analyses can be used to address a variety of questions on the evolution of wood structure and the ecological and phylogenetic significance of suites of features.
Wood Anatomy in Japan Since Its Early Beginnings
Authors: Sudo Syoji
Published: July 2014

The history of wood anatomy in Japan, which goes back to 1882, is reviewed, based on a comprehensive literature study. In the early phase most publications dealt with descriptive wood anatomy and identification, while later publications are highly diversified. The beginning of Japanese wood anatomy coincided with the publication of Nakamura's PhD thesis in Munich on the wood anatomical properties and identification of Japanese softwood species. In subsequent decades, several wood anatomists have made studies in Nakamura's footsteps on the Japanese soft- and hardwood species, in the tradition of the German school of comparative plant anatomy. In the first half of the 20th century, the development of wood anatomy in Japan is dominated by the work of Fujioka, Kanehira, Kawai, Yamabayashi and their collaborators and students. In this period there was a growing interest in timber species from abroad. In the second half of the 20th century, activities have steadily increased with a growing number of wood anatomists. Electron microscopic studies on wood began in the Government Forest Experiment Station in the nineteen-fifties, led by Harada, who later continued his research and teaching at Kyoto University. Other centres of wood ultrastructural research soon followed. A large number of research reports and books has been published on the wood anatomy of tropical species. This is because of the influx on the market of a huge volume of imported logs from a great number of lesser-known tropical species since the mid nineteen-sixties. Names of Fujioka and Kanehira are found in the list of the IAWA founders and since the foundation of IAWA the participation of Japanese wood anatomists has seen an upward tendency.
Wood Anatomy of Endemic RHAMNUS Species In The Mediterranean Region of Turkey
Authors: Akkemik Ünal , Efe Asuman , Kaya Zafer , Demir Dilek
Published: July 2014

The wood anatomy is described of five Rhamnus species endemic in the Mediterranean region of Turkey, and ecological adaptations are discussed. The wood of all species is drought-adapted with low mesomorphy values (range 11–23), high vessel frequencies (277–457/mm2), spiral thickenings, low vessel diameters (22–35 μm) and short vessel elements (189–240 μm). The vessels are grouped in a dentritic pattern with abundant vasicentric and vascular tracheids.
Comparative Anatomy of the Bark of Stems, Roots and Xylopodia of Brosimum Gaudichaudii (Moraceae)
Authors: Palhares Dario , de Paula José Elias , Rodrigues Pereira Luiz Alfredo , dos Santos Silveira Conceição Eneida
Published: July 2014

Brosimum gaudichaudii Tréc. occurs in the Atlantic and Amazon forests, and is the only species of Brosimum commonly found in Cerrado vegetation. It is of pharmaceutical interest due to the large accumulation of furocoumarins such as psoralens in the bark of roots and xylopodia. This work describes the bark anatomy of sterns, roots, and xylopodia. Although the external bark morphology of stern and subterranean system are different, anatomically they are similar, with both having wavy and fused rays at the outer region of the phloem and a gradual transition between pervious (non-collapsed) and collapsed phloem. Tbe stern and bark periderms have three to seven layers of cells. The bark of younger stern regions is different from the bark of older parts of the stern. Younger stern parts have higher abundance of laticifers in the phloem, and gelatinous fibers arranged in bundles. Compared with the younger regions, older sterns have fewer laticifers and the gelatinous fibers are scattered in the phloem. The root and the xylopodium bark are structurally similar to each other, with a higher abundance of laticifers than sterns. Starch was found in the roots, but not in sterns.
A taxonomic revision of the Capparis spinosa group (Capparaceae) from the Mediterranean to Central Asia
Authors: Fici Silvio
Published: July 2014

A revision of the Capparis spinosa group has been carried out in southern Europe, northern Africa, western and central Asia, in order to provide a uniform taxonomic treatment of its representatives. The xerotropical origin of this group, showing disjunct distribution in several holoarctic and paleotropical regions, is underlined and the different species concepts historically adopted are discussed. In the present treatment a single species is recognized, C. spinosa, represented in the study area by two subspecies. C. spinosa subsp. spinosa shows derived characters, high polymorphism and a wide distribution range from the Mediterranean eastwards to China and Nepal. C. spinosa subsp. rupestris, less variable and showing phenotypic characters closer to the  tropical stock of the group, is recorded in the Mediterranean Region and the Sahara. On the basis of  herbarium and field investigations, the variability and distribution of the two subspecies are examined. Within each subspecies some varieties are recognized, for which morphological, chorological and autecological data are presented. Four new combinations (C. spinosa subsp. spinosa var. herbacea, C. spinosa subsp. spinosa var. atlantica, C. spinosa subsp. rupestris var. ovata, C. spinosa subsp. rupestris var. myrtifolia) are proposed.
Strengthening practicum conversations: Enhancing professional learning and development through returning lecturer supervisions
Authors: Ussher Bill , Carss Wendy
Published: July 2014

Relationships between teachers, children and university lecturers must be positive, productive and professional to optimise the learning and development of student teachers in school-based experiences. The limited research into these ‘high stakes’ relationships mostly explores alternative approaches. This paper explores the perceptions of student teachers and associate teachers as they consider the value of an alternative practicum supervision approach. The lecturers supervised and mentored the student teachers in all of their practicum experiences. Findings indicate a clear preference for this approach, mostly because of reduced stress, especially in the final practicum. The lecturer was a stable influence with a greater depth of knowledge of the student’s learning journey. The later visits were future-focused, identifying next steps in developing both strengths and weaknesses. There are some current examples of this approach, but these participants suggest that it should be common practice because of the value of the professional conversations that occurred.