Missing Ring Research Articles

Missing rings of Qilian juniper associated with drought on the Northeastern Tibetan Plateau, China

A missing ring occurs when the radial growth of a tree is disturbed when the plant is under stress (e.g., extreme drought, fire, insect attack, frost) as a result of inhibition of cambial activities. Missing rings have been detected in several tree species in different parts of the world, and this phenomenon may be an indicator of imminent tree death. However, we still lack an in-depth understanding of the characteristics and causes of missing rings and their relationship with tree mortality. In this study, we examined missing ring occurrence in Qilian juniper (Juniperus przewalskii Kom.), one of the most long-lived tree species in China, growing in an extremely harsh environment on the Northeastern Tibetan Plateau. The results showed that the missing ring rate was sensitive to drought events during the period 1500–2000 AD, with extreme values of missing ring rate occurring in certain drought years, such as 1665, 1687, 1715, 1824, 1918, etc. In addition, climate warming in recent decades did not lead to an increase in the missing ring rate of Qilian juniper, which may be related to the improving regional water conditions on the plateau. The missing ring rate of Qilian juniper was related to the age of the tree, i.e., it increased first in younger trees and then decreased, with the highest missing ring rate occurring in trees about 800-years-old. Furthermore, trees that eventually died had a higher rate of missing rings before their death than those that survived, suggesting that missing rings have the potential to predict tree mortality. However, the relationship between tree mortality and missing ring rate is a very complex issue and requires further study.

Type 2 Diabetes and Alzheimer's Disease: The Emerging Role of Cellular Lipotoxicity.

Type 2 diabetes (T2D) and Alzheimer's diseases (AD) represent major health issues that have reached alarming levels in the last decades. Although growing evidence demonstrates that AD is a significant comorbidity of T2D, and there is a ~1.4-2-fold increase in the risk of developing AD among T2D patients, the involvement of possible common triggers in the pathogenesis of these two diseases remains largely unknown. Of note, recent mechanistic insights suggest that lipotoxicity could represent the missing ring in the pathogenetic mechanisms linking T2D to AD. Indeed, obesity, which represents the main cause of lipotoxicity, has been recognized as a major risk factor for both pathological conditions. Lipotoxicity can lead to inflammation, insulin resistance, oxidative stress, ceramide and amyloid accumulation, endoplasmic reticulum stress, ferroptosis, and autophagy, which are shared biological events in the pathogenesis of T2D and AD. In the current review, we try to provide a critical and comprehensive view of the common molecular pathways activated by lipotoxicity in T2D and AD, attempting to summarize how these mechanisms can drive future research and open the way to new therapeutic perspectives.

Laryngeal signs and pH-multichannel intraluminal impedance in infants and children: The missing ring: LPR and MII-pH in children

Objectiveto investigate the reliability of laryngeal reflux finding score (RFS) and symptom index (RSI) in assessing gastroesophageal reflux (GER) in children and infants. Methodspatients with laryngeal or respiratory symptoms, who underwent laryngoscopy and esophageal pH-impedance (MII-pH) were recruited. RSI and RFS were correlated to MII-pH results. A RSI>13, RFS>7, acid exposure index>7%, total reflux episodes>100/24 h in infants or>70/24 h in children, or a positive symptom index or association probability, were considered pathological. Analysis considering age (</>12 months) was performed. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of the laryngeal scores were calculated. Results197 children (median 53 months, 61 infants) were enrolled. MII-pH was pathological in 5/10 patients with RFS>7, and in 17/31 with RSI>13. RFS>7 had 3.9% sensitivity, 93% specificity, a PPV of 50 and a NPV of 34 in predicting GER disease. RFS was inversely associated to weakly acidic and proximal GER. RSI>13 had 13% sensitivity, 83% specificity, and a PPV and NPV similar to RFS. RSI was significantly associated with the number of acid reflux episodes, and, in infants, with bolus exposure index. ConclusionsRSI and RFS aren't accurate in predicting GER in infants and children. Acid reflux relates to laryngeal symptoms, but neither acid, nor proximal and weakly acidic GER relate to laryngeal alterations.

MISSING AND DARK RINGS ASSOCIATED WITH DROUGHT IN PINUS HALEPENSIS

The responses of the vascular cambium and tracheid differentiation to extreme drought in Aleppo pine (Pinus halepensis Mill.) were investigated. The research focused on the drought year of 2005, in the primary study area at Maigmo (MAI) in southeastern Spain, with comparisons in Jarafuel (JAL) and Guardamar (GUA). The climate in this region is typically warm and dry with hot summers. Wood formation throughout the 2005 growing season was studied in transverse microtome sections and integrated with a retrospective dendrochronological analysis of crossdated increment cores collected in 2009. For most anatomical sections collected throughout the growing season at MAI, the vascular cambium appeared to be dormant as indicated by the low number of cells per radial file. Occasionally, immature xylem derivatives were observed during the growing season but without production of an annual ring. In increment cores collected at MAI, the 2005 position in the annual ring series contained either a narrow ring of both earlywood and latewood (47% of samples), a narrow ring of apparent latewood with no earlywood (13%), or a missing ring (50%). We introduce the term “dark ring” to refer to those annual rings of apparent latewood with no earlywood. For trees at JAL, the 2005 ring had below-average width and contained both earlywood and latewood. At GUA, the trees produced the widest 2005 ring of all three sites and mainly contained an intra-annual density fluctuation (IADF). The IADF was formed after cambial reactivation in the autumn. Although dark rings, IADFs, and especially missing rings complicate dendrochronological analysis, these anatomical features may provide an additional proxy record from which to infer climate variability and change in the past.

Missing Rings in Pinus halepensis - The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events.

Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees to adverse environmental conditions. The demonstrated relationship of MR formation to ECE across this dendrochronological network in the Mediterranean basin shows the potential of MR analysis to reconstruct the history of past climatic extremes and to predict future forest dynamics in a changing climate.

New Perspectives in Therapy of Intoxications by Organophosphoric Compounds

Little references actually exist on neutralization therapy which could constitute the missing ring from an efficient treatment. As structural model capable to interact with organophosphoric substances, at the level of phosphor (P) atom, the common chemical element of the hole class of substances, was proposed those of benzimidazole. Different quantities of benzimidazole were put in contact with a fix quantity of trichlorphon in acid conditions and formation of a new compound was evidentiated by infrared spectrometry. Similar experiments were made utilizing benzimidazole derivatives (2 methyl or 2 benzyl benzimidazole) and different temperatures: 35°C and 40°C. By increasing massic rate: benzimidazole/triclorfon as well an increased reaction temperature, have favourably influenced trichlorphon capture. The obtained results justified an continuation of researches in the direction of new compounds with a structure similar with that of benzimidazole for funding an efficient neutralization therapy for organophosphoric substances.

Diameter increment of beech in relation to social position of trees, climate characteristics and thinning intensity

1Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic 2Forestry and Game Management Research Institute, Jíloviště-Strnady, Opočno Research Station, Opočno, Czech Republic ABSTRACT: We present the results of research on diameter increment in beech stands in the area of Hostýnské and Vsetínské vrchy. The data were collected on three series of permanent research plots (PRP) in middle-aged stands in the property of BFP Forests and Estates of Tomas Baťa, Ltd. established for the evaluation of the effect of different thinning regimes. Each series consists of one control plot and two plots with different treatment intensity. The objective of this paper was to assess the increment response of beech individuals in the first year after a thinning intervention and to evaluate the increment of sample trees in relation to the social position of tree in the stand and the climate trends in the last 30 years. The diameter increment was evaluated on harvested sample trees, after the thinning treatment the growth reaction of standing sample trees of the main stand was evaluated based on their dendrometric characteristics. To calculate the radial growth of beech, the annual ring increment series were cross-dated individually (to eliminate errors caused by missing annual rings) using statistical tests in the PAST4 application software (Knibbe 2007) and then subjected to visual inspection according to Yamaguchi (1991). If a missing annual ring was found, a ring 0.01 mm wide was inserted in its place. The individual curves from PRPs were then detrended and an average annual ring series was created in the ARSTAN software. First a negative exponential spline was used, and then the 30-year spline was applied (Grissino-Mayer et al. 1992). The response of tree radial growth to climatic factors was evaluated using the DendroClim software. The method of single pointer years analysis was used to estimate the influence of extreme climatic events on diameter growth. One year after thinning, the harvest intensity had no significant effect on the radial growth of dominant trees (F(4, 293) = 1.0, P > 0.05), but oppositely, differences in the average diameter increment of co-dominant trees on PRPs were statistically significant (F(4, 362) = 2.6, P < 0.05). The diameter increment of dominant trees in 1978-2013 showed positive correlations with the March temperatures of the current year (r = 0.27) and negative ones with June-September (r = -0.28 to -0.43) and November (r = -0.36) of the last year and April, June and July (r = -0.35 to -0.44) of the current year. Negative correlations of temperature in the growing season of the current year were similar to dominant trees, only the impact was weaker in April to August (r = -0.28 to -0.32). According to the results of the PCA analysis, annual ring width was negatively correlated with temperatures in the vegetation season of the last year and current year, July, April and June temperature of the current year, and with precipitation in January-March of the current year.

Postoperative outcome after oesophagectomy for cancer: Nutritional status is the missing ring in the current prognostic scores

BackgroundSeveral prognostic scores were designed in order to estimate the risk of postoperative adverse events. None of them includes a component directly associated to the nutritional status. The aims of the study were the evaluation of performance of risk-adjusted models for early outcomes after oesophagectomy and to develop a score for severe complication prediction with special consideration regarding nutritional status. MethodsA comparison of POSSUM and Charlson score and their derivates, ASA, Lagarde score and nutritional index (PNI) was performed on 167 patients undergoing oesophagectomy for cancer. A logistic regression model was also estimated to obtain a new prognostic score for severe morbidity prediction. ResultsOverall morbidity was 35.3% (59 cases), severe complications (grade III–V of Clavien–Dindo classification) occurred in 20 cases. Discrimination was poor for all the scores. Multivariable analysis identified pulse, connective tissue disease, PNI and potassium as independent predictors of severe morbidity. This model showed good discrimination and calibration. Internal validation using standard bootstrapping techniques confirmed the good performance. ConclusionsNutrition could be an independent risk factor for major complications and a nutritional status coefficient could be included in current prognostic scores to improve risk estimation of major postoperative complications after oesophagectomy for cancer.

Patient, ready, and daring would-be shogun-spirits: a secret of Japan's silicon valley, ‘hamamatsu’

Hamamatsu region can be regarded as a sort of ‘Silicon Valley’ in Japan. Why have some world-renowned companies as Toyota, Honda, Yamaha, and Suzuki still emerged from this narrow region? Why do even small and medium-sized enterprises (SMEs) there tend to invest in long-term research and development (R&D)? And what is the Japanese SMEs’ solution to the puzzling mismatch between consistency and flexibility? As keywords for above research questions, start-up as an innovative SME is defined as a portfolio of real options, by regarding entrepreneur's ideas as investment opportunities. And long-term R&D investment means a call option as the flexible decision right to make the commercialisation investment if future business condition becomes favorable. As a research tool for conceptual perspective, real options approach is a methodology for evaluating and designing the flexibility of irreversible investment in real assets as R&D projects under uncertainty. This paper's objective is firstly to explain R&D investment as a call option of real options, secondly to find a missing ring between consistency and flexibility in Hamamatsu as a sustainable innovation center, and thirdly to examine viability of long-term R&D strategy of a Japanese SME, Hamamatsu Photonics KK.

2-Chloro- and 2-bromo-3-pyridinecarboxaldehydes: Structures, rotamers, fermi resonance and vibration modes

FT-Infrared (4000–400 cm −1) and NIR-FT-Raman (4000–50 cm −1) spectral measurements have been made for 2-chloro- and 2-bromo-3-pyridinecarboxaldehydes. A DFT vibration analysis at B3LYP/6-311++G (d,p) level, valence force-fields and vibrational mode calculations have been performed. Aided by very good agreement between observed and computed vibration spectra, a complete assignment of fundamental vibration modes to the observed absorptions and Raman bands has been proposed. Orientations of the aldehydic group have produced two oblate asymmetric rotamers for each molecule, ON- trans and ON- cis: the ON- trans rotamer being more stable than cis by 3.42 kcal mol −1 for 2-chloro-3-pyridinecarboxaldehyde and 3.68 kcal mol −1 for 2-bromo-3-pyridinecarboxaldehyde. High potential energy barrier ca 14 kcal/mol, induced by steric hindrance, restricts rotamers’ population to ON- trans only. It is observed that, in the presence of bromine, C–H stretching modes are pronounced; a missing characteristic ring mode in chlorine's presence shows at 1557 cm −1; the characteristic ring mode at 1051 cm −1 is diminished; a mixed mode near 707 cm −1 is enhanced. Further, an observed doublet near 1696–1666 cm −1 in both IR and Raman spectra is explained on the basis of Fermi resonance between aldehydic carbonyl stretching at 1696 cm −1 and a combination mode of ring stretch near 1059 cm −1 and deformation vibration, 625 cm −1. A strong Raman aldehydic torsional mode at 62 cm −1 is interpreted to correspond to the dominant ON- trans over cis rotamers population.

Musings on privacy issues in health research involving disaggregate geographic data about individuals.

This paper offers a state-of-the-art overview of the intertwined privacy, confidentiality, and security issues that are commonly encountered in health research involving disaggregate geographic data about individuals. Key definitions are provided, along with some examples of actual and potential security and confidentiality breaches and related incidents that captured mainstream media and public interest in recent months and years. The paper then goes on to present a brief survey of the research literature on location privacy/confidentiality concerns and on privacy-preserving solutions in conventional health research and beyond, touching on the emerging privacy issues associated with online consumer geoinformatics and location-based services. The 'missing ring' (in many treatments of the topic) of data security is also discussed. Personal information and privacy legislations in two countries, Canada and the UK, are covered, as well as some examples of recent research projects and events about the subject. Select highlights from a June 2009 URISA (Urban and Regional Information Systems Association) workshop entitled 'Protecting Privacy and Confidentiality of Geographic Data in Health Research' are then presented. The paper concludes by briefly charting the complexity of the domain and the many challenges associated with it, and proposing a novel, 'one stop shop' case-based reasoning framework to streamline the provision of clear and individualised guidance for the design and approval of new research projects (involving geographical identifiers about individuals), including crisp recommendations on which specific privacy-preserving solutions and approaches would be suitable in each case.

Quadruple H therapy for vasospasm.

Triple H therapy has been enthusiastically used to increase cerebral blood flow in cases of vasospasm. Nevertheless, the oxygen-carrying capacity of the blood is lowered with this treatment. This side effect can theoretically be partially corrected using hyperbaric oxygen therapy (HBO) which appears to be the missing ring in the above therapeutic regimen. We conducted a review of of the available evidence regarding the beneficial effects of HBO in preventing postoperative ischemic complications due to vasospasm after surgery on ruptured cerebral aneurysms and the rationale for including HBO into the standards of care of these difficult patients.

New Monascus metabolites: Structure elucidation and toxicological properties studied with immortalized human kidney epithelial cells

Monascus sp. are used for the production of red yeast rice, which has been applied in Asian food and medicine for centuries. The fungi form several secondary metabolites, among others the monascopyridines A and B. We have now detected two new monascopyridines (named C and D) with similar UV absorption spectra and maxima at 306-307 nm in red rice fermented with M. purpureus. The new monascopyridines have the same chromophores as the already known and differ in a missing gamma-lactone ring only. Monascopyridine C has a hexanoyl side chain, whereas monascopyridine D is the higher homologue with an octanoyl side chain. The toxicological properties of monascopyridines were studied using immortalized human kidney epithelial cells, displaying cytotoxic effects in micromolar concentrations with median effective concentration values between 20.7 and 43.2 micromol/L, depending on the compound and method used. The monascopyridines C and D did not induce apoptosis. However, they caused a rise of the mitotic index from 3.21 +/- 0.27% (control) to maximum 8.14 +/- 0.89% (monascopyridine D) by an accumulation of cells in the metaphase with a simultaneous decrease of cells in the ana- and telophase. Monascopyridine-induced metaphase arrest is caused by a partial or complete loss of the spindle apparatus as indicated by the occurrence of abnormal metaphases and immunological staining of alpha-tubulin. These effects are indicating an aneuploidic potential and therefore the monascopyridines C and D might contribute to tumor formations.

Early summer temperatures since 1670 A.D. for Central Kamchatka reconstructed based on a Siberian larch tree-ring width chronology

A tree-ring width chronology of larch (Larixkurilensis Mayr) has been developed from along the Bystraya River near Esso in the interior valley of the Kamchatka Peninsula, Russia. The chronology, which covers from 1670 to 1992, explains 38% of the variance in May–June temperatures for the Esso meteorological station. This ring-width series is used to develop the first dendroclimatic reconstruction for Kamchatka. We caution that the Esso station record, the closest to the tree-ring site, is only 42 years in length, making model verification difficult. Periods of above-average temperatures are inferred for ca. 1750, 1800, and over the last few decades; colder than average conditions are inferred for 1710–1720, 1760–1770s, and 1860–1880s. The ring-width chronology cross-dates with other larch tree-ring data for Kamchatka and, during certain intervals, with a larch ring-width record from eastern Siberia. Comparison of the two records suggests that the insertion of a missing ring for the year 1816 in the eastern Siberian series is not justified. A birch (Betulaermanii Cham.) chronology from a coastal site near Petropavlovsk-Kamchatskiy correlates with July–August temperatures. Both the larch and more widespread birch species show promise for further dendroclimatic studies in Kamchatka.

14C and 90Sr measurements at the Erlangen AMS facility

The AMS beamline at the Erlangen EN tandem accelerator has been completed and improved. The high-current Cs sputter ion source has been finished and is being used mainly with carbon and SrF 2 samples. Sample exchange is done by remote control, under high voltage and without breaking the vacuum. Fast isotope switching is performed by applying high voltage pulses of adjustable length at the chamber of the 90° injection magnet, which can be used for different kinds of ions and beam currents. Using a new 120° magnetic split-pole spectrograph, 90Sr was measured at isotopic ratios 90Sr/ 88Sr between 10 −9 and 10 −8 for environmental applications. Radiocarbon dating of samples along the cross section of tropical trees yielded information about the growth rhythms of the tropical wood, which are difficult to determine because of missing tree ring patterns.

The effect of virulent and hypovirulent strains of Endothia parasitica on hydraulic conductance in American chestnut

Measurements of hydraulic conductance per unit length (Kh) were made on stems of Castanea dentata (Marsh) Borkh. that were inoculated with virulent and hypovirulent strains of Endothia parasitica and on stems with naturally occurring (wild) cankers. For stem segments infected with virulent strains (virulent infections), Kh values were significantly lower (p &lt; 0.01) than in healthy control stems or in stem segments immediately above or below the canker. Adjacent segments were not significantly different from controls at the 0.05 level of probability. For hypovirulent infections, the Kh of canker segments, adjacent segments, and controls were not significantly different from one another. Dye ascents and descents indicated the xylem conductive area was sharply reduced in stem segments with virulent, but not hypovirulent, infections. Stem segments with wild virulent infections showed not only a reduction in xylem conductive area, but often a missing or incomplete outer xylem growth ring. Segments with wild hypovirulent infections often showed an incomplete outer xylem growth ring, with the intact portion of the outer growth ring (or rings) often quite swollen and sometimes with anomalous vascular bundles. It is concluded that xylem dysfunction is strongly correlated with reductions in Kh and with death of the leaves distal to virulent infections.

Changes in the Growth Pattern of White Pine Trees Undergoing Suppression

The phenotypic responses of suppressed trees were studied in a 60—year—old white pine stand. The first evidence of suppression is a tree—wide decrease in the production of secondary xylem. Height growth is relatively insensitive. During the latter 30 years of life suppressed trees made 50.7% of their total height growth but only 19.1% of their total diameter growth. Eventually the cambium fails to cut off xylem at the base of the tree. With time, the sheath of new—formed xylem retreats from the based giving rise to an increasingly large zone of missing rings. Girdling experiments indicate that diminished supplies of food and growth regulators move through the zone of missing rings to support primary root growth. Apparently the phloem remains functional in the zone of missing rings. Either the phloem can function for periods greater than 1 or 2 years, or the cambium cuts off phloem alone in the missing ring zone. In the normal cambial cycle, phloem alone is produced during the last part of the growing season. It is proposed that a physiological threshold exists below which growth conditions are inadequate for the production of secondary xylem but remain favorable for the production of primary root growth and possibly for secondary phloem. This physiological mechanism is of considerable ecological significance since, as suppression proceeds, the plant invests a higher and higher proportion of its decreasing energy supply in primary growth or in all tissues that require annual renewal thus prolonging its survival. Hence, the growth of white pine, while undergoing suppression, illustrates the principle of phenotypic adaptability.