Diameter Growth Rate Research Articles

Branch occlusion and discoloration of Betula alnoides under artificial and natural pruning

Knot-related defects are important criteria for timber grading of valuable tree species. Clear-wood production through pruning has been an important issue in silviculture and forest management. In this study, knot attributes, branch occlusion and discoloration under natural and artificial pruning were investigated in a 10-year-old Betula alnoides plantation to determine the effectiveness of artificial pruning in mitigating knot-related defects. The dataset contained 270 occluded branches sampled from 30 artificially-pruned trees and 284 from 30 trees under natural pruning. Linear and generalized linear mixed-effect models were constructed to reveal the differences in factors influencing branch occlusion, knot size, and discoloration between natural and artificial pruning treatments. The mixed-effect models indicated that the most important factor in predicting branch occlusion time, dead knot radius, total knot radius and discoloration length was branch diameter for artificial pruning and dead branch stub length for natural pruning. The dead branch stub length was also closely and positively correlated with branch diameter under natural pruning. Branch occlusion time was negatively correlated with stem diameter growth rate during the period of branch occlusion while discoloration length was positively correlated with branch occlusion time for both treatments. In addition, acute branch insertion angle increased the size of dead knot and discoloration. It was concluded that artificial pruning promotes faster branch occlusion, reduces knot sizes and does not lead to stem discolorations, and should hence be applied in the plantation management of this species.

Prenatal and postnatal growth: An ultrasound and clinical investigation

Background Understanding facial development requires sound knowledge of growth at different stages. Although studies in the past have established the relationship between prenatal and postnatal growth, little research has been done using noninvasive ultrasound. The purpose of this study is to evaluate correlation between prenatal and postnatal growths using ultrasound as a fetal growth assessment tool. Study Settings: It is a hospital-based study where prenatal growth is measured at different intervals of gestational period and compared with the growth at birth. Materials and Methods: Ten subjects with normal pregnancy were studied using ultrasound. Cephalocaudal growth gradient, body proportions of the fetus were assessed and compared at different stages. Growth was also evaluated at birth and compared with the predicted growth. Results The growth rate of estimated fetal weight is at maximum between the 28th and 32nd week of the fetal life (P ≤ 0.001). The growth rate of head circumference, occipitofrontal diameter, and femur length is maximum between the 20th and 28th week of the fetal life (P < 0.001). Cephalocaudal growth gradient decreases with increased age of the fetus. Conclusions Prenatal growth is correlated with postnatal growth. Ultrasound can be used as a tool for the measurement and prediction of prenatal and postnatal growths.

Expression of Genes by Aflatoxigenic and Nonaflatoxigenic Strains of Aspergillus flavus Isolated from Brazil Nuts.

The aims of the present study were to monitor the production of aflatoxin B1 (AFB1) and mycelial growth, and to evaluate the expression of genes directly and indirectly involved in the biosynthesis of aflatoxins by Aspergillus flavus isolated from Brazil nuts. Six previously identified A. flavus strains were grown on coconut agar at 25°C for up to 10 days. Mycotoxins were separated by high-performance liquid chromatography and fungal growth was measured daily using the diametric mycelial growth rate. Transcriptional analysis was performed by real-time polymerase chain reaction (PCR) after 2 and 7 d of incubation using specific primers (aflR, aflD, aflP, lipase, metalloprotease, and LaeA). Three (50%) of the six A. flavus isolates produced AFB1 (ICB-1, ICB-12, and ICB-54) and three (50%) were not aflatoxigenic (ICB-141, ICB-161, and ICB-198). Aflatoxin production was observed from d 2 of incubation (1.5 ng/g for ICB-54) and increased gradually with time of incubation until d 10 (15,803.6 ng/g for ICB-54). Almost all A. flavus isolates exhibited a similar gene expression pattern after 2 d of incubation (p > 0.10). After 7 d of incubation, the LaeA (p < 0.05) and metalloprotease (p < 0.05) genes were the most expressed by nonaflatoxigenic strains, whereas aflatoxigenic isolates exhibited higher expression of the aflR (p < 0.05) and aflD genes (p < 0.05). Our results suggest that the expression of aflR and aflD is correlated with aflatoxin production in A. flavus and that overexpression of aflR could affect the transcriptional and aflatoxigenic pattern (ICB-54). Elucidation of the molecular mechanisms that regulate the secondary metabolism of toxigenic fungi may permit the rational silencing of the genes involved and consequently the programmed inhibition of aflatoxin production. Knowledge of the conditions, under which aflatoxin genes are expressed, should contribute to the development of innovative and more cost-effective strategies to reduce and prevent aflatoxin contamination in Brazil nuts.

Determination of Growth Rate and Age Structure of &lt;i&gt;Boswellia papyrifera&lt;/i&gt; from Tree Ring Analysis: Implications for Sustainable Harvest Scheduling

Boswellia papyrifera is a multipurpose deciduous species that grows in Combretum – Terminalia deciduous woodlands of Ethiopia. It is widely known for its commercial frankincense production. The B. papyrifera woodland is under a problematic state of population decline due to heavy encroachment and unsustainable tapping. To sustainably manage such a sensitive ecosystem needs exact knowledge of growth rates and age structure of trees where such information on tropical trees under natural condition is rather poor. In this study growth rate and age of B. papyrifera was determined from tree ring analysis. The study was carried out in Lemlem Terara, Metema district, Ethiopia. The mean annual diameter growth rate of B. papyrifera derived from the mean ring-width is 2.32mm and varies among sample trees. All sampled trees showed a comparable general growth trend which can be divided into three phases – i) good growth in the beginning, ii) phase with depression in middle and iii) increase in ring width. The average age of B. papyrifera trees growing in the study site is estimated to be about 75 years. Although there is strong correlation between diameter of a tree and age, the result from this study highlighted that age-size relations should be used cautiously as the diameter may not reflect the true age. The result from this study is important input to develop strategic plan for the species regarding tapping frequency and intensity as per the annual increment of the species. For further dendrochronological studies of the species, it is recommended to take samples from different size classes and slope gradients for better and reliable results. In future, the use of tree ring analysis as a tool to understand growth dynamics and age structure of trees species, and their response to climate variability should be strengthen in Ethiopian. Keywords: Boswellia papyrifera, Annual growth rings, Diameter growth rate, Age structure, Ethiopia.

Volume growth of abdominal aortic aneurysms correlates with baseline volume and increasing finite element analysis-derived rupture risk

The diagnosis and management of abdominal aortic aneurysms (AAAs) currently relies on the aortic maximal diameter, which grows in an unpredictable manner. Infrarenal aortic volume has recently become clinically feasible to measure, and an estimate of biomechanical rupture risk derived from finite element analysis, the peak wall rupture index (PWRI), has been shown to predict AAA rupture. Our objective was to ascertain how well volume growth correlates with baseline volume and increasing PWRI, compared with the maximal diameter. We retrospectively identified 41 AAA patients (nine women, 32 men) at our institution who had undergone two computed tomography angiographies with an interval of 8 to 17months. Digital three-dimensional reproductions of the aneurysms were segmented from the 82 computed tomography angiographies. AAA diameter, volume, and PWRI were measured and calculated with finite element analysis software. Growth rates of diameter and volume were related to baseline diameter and volume as well as to change rates of PWRI. Significant growth was defined as growth exceeding our interobserver 95% limits of agreement. Diameter growth rate did not correlate with baseline diameter (r= 0.15, 95% confidence interval [CI],-0.17 to 0.45), but volume growth rate correlated with baseline volume (r= 0.56; 95% CI, 0.30-0.75). The correlation between baseline volume and volume growth rate was stronger than the correlation between baseline diameter and diameter growth rate (95% CI, 0.086-0.71). Increasing PWRI correlated with volume growth rate (r= 0.70; 95% CI, 0.40-0.87) but not with diameter growth rate (r= 0.044; 95% CI,-0.44 to 0.51), and the difference between the correlation coefficients was significant (95% CI, 0.11-1.16). Volume better predicts aneurysm growth rate and correlates stronger with increasing estimated biomechanical rupture risk compared with diameter. Our results support the notion of monitoring all three dimensions of an AAA.

Long-term growth rate of vestibular schwannoma in neurofibromatosis 2: A volumetric consideration

To determine the long-term growth rate of vestibular schwannoma (VS) in neurofibromatosis type 2 (NF2) patients based on volumetric measurements. Retrospective review. We retrospectively reviewed magnetic resonance imaging (MRI) scans acquired from patients with NF2 from 1999 to 2013. Patients with an annual radiologic follow-up over at least 3 consecutive years were included. Volumetric VS growth was prospectively measured using a three-dimensional imaging workstation and through manual contouring of the lesion. Time to tumor progression was assessed according to the Response Evaluation in Neurofibromatosis and Schwannomatosis Tumor Measurement Group. Eighteen patients presenting with a total of 26 VSs were included. The mean age at diagnosis was 26.1 years (range, 7 to 49 years). One hundred five MRI scans were analyzed during a median radiological follow-up of 5.6 years (range, 3 to 12 years). The annual volume and diameter growth rates were respectively 218.3 mm(3) /yr (range, -10 to 1,250 mm(3) /yr) and 0.9 mm/yr (range, -0.5 to 4.5 mm/yr). Time to tumor progression was 3 years (median survival). There was a weak correlation between volumetric and linear measurements (P < .0001, linear regression, n = 26, r(2) = 0.58). Among the 26 VSs, 76.9% (20/26) showed progression (VS growth more than 20%), 19.2% were stable, and 3.9% (1/26) exhibited shrinkage (spontaneous regression of more than 20% of the initial volume). This study helps to assess the long-term growth profile of VS in a population of NF2 patients with untreated VS. These data could help to better acknowledge VS natural growth history. 4 Laryngoscope, 126:2358-2362, 2016.

How do size distributions relate to concurrently measured demographic rates? Evidence from over 150 tree species in Panama

Abstract:In stable populations with constant demographic rates, size distributions reflect size-dependent patterns of growth and mortality. However, population growth can also affect size distributions, which may not be aligned with current growth and mortality. Using 25 y of demographic data from the 50-ha Barro Colorado Island plot, we examined how interspecific variation in diameter distributions of over 150 tropical trees relates to growth–diameter and mortality–diameter curves and to population growth rates. Diameter distributions were more skewed in species with faster increases/slower decreases in absolute growth and mortality with diameter and higher population growth rates. The strongest predictor of the diameter distribution shape was the exponent governing the scaling of growth with diameter (partial R2 = 0.20–0.34), which differed among growth forms, indicating a role of life history variation. However, interspecific variation in diameter distributions was also significantly related to population growth rates (partial R2 = 0.03–0.23), reinforcing that many populations are not at equilibrium. Consequently, although fitted size distribution parameters were positively related to theoretical predictions based on current size-dependent growth and mortality, there was considerable deviation. These analyses show that temporally variable demographic rates, probably related to cyclic climate variation, are important influences on forest structure.

Analysis on the Absolute Growth Rate of Rhizophora mucronata Seedling in Silvicultural Pond Canals by the Influence of Initial Condition and Changes of Environment Quality

&lt;p&gt;Mangrove seedling growth in silvofishery pond is limited to water quality dynamics while the water quality dynamically changes. This research aimed to study the changes of environmental factor condition in silvofishery pond and to analyze its impacts on the growth of mangrove seedling. Research experiment involved18 treatment plots with mangrove Rhizophora mucronata seedling. Observed parameters included temperature, turbidity, salinity, pH, DO, TSS, BO, N and P. Calculation was conducted for the deviation of each parameters. Mangrove growth parameters were including height and diameter growth while its data processing was absolute daily growth. Data analysis was conducted through regression. The result showed there were changes on environment parameters. Growth rate of R. mucronata showed variations on absolute daily height growth rate range of 0.215-3.333 mm/day (average 1.296 ±0.036 mm/day), while absolute daily diameter growth rate range was 2.15x10-3-0.196 mm/day (average 4.25x10-2 ± 3.59x10-2 mm/day). The analysis of regression showed several parameters effectedthe growth of mangrove seedlings including temperature, temperature change, turbidty, salinity change, pH, pH change, and DO on the growth of R. mucronata seedlings. This research concluded that environment parameters and its changes had significant effects on the growth of mangrove seedling. &lt;/p&gt;&lt;p&gt;&lt;strong&gt;How to Cite&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Hastuti, E., &amp;amp; Budihastuti, R. (2016). Analysis on the Absolute Growth Rate of Rhizophora mucronata Seedling in Silvicultural Pond Canals by the Influence of Initial Condition and Changes of Environment Quality. &lt;em&gt;Biosaintifika: Journal of Biology &amp;amp; Biology Education&lt;/em&gt;, 8(1), 56-63.&lt;/p&gt;

A New Model for Size-Dependent Tree Growth in Forests.

Tree growth, especially diameter growth of tree stems, is an important issue for understanding the productivity and dynamics of forest stands. Metabolic scaling theory predicted that the 2/3 power of stem diameter at a certain time is a linear function of the 2/3 power of the initial diameter and that the diameter growth rate scales to the 1/3 power of the initial diameter. We tested these predictions of the metabolic scaling theory for 11 Japanese secondary forests at various growth stages. The predictions were not supported by the data, especially in younger stands. Alternatively, we proposed a new theoretical model for stem diameter growth on the basis of six assumptions. All these assumptions were supported by the data. The model produced a nearly linear to curvilinear relationship between the 2/3 power of stem diameters at two different times. It also fitted well to the curvilinear relationship between diameter growth rate and the initial diameter. Our model fitted better than the metabolic scaling theory, suggesting the importance of asymmetric competition among trees, which has not been incorporated in the metabolic scaling theory.

RELATIONSHIP BETWEEN CLIMATE VARIABLES, TRUNK GROWTH RATE AND WOOD DENSITY OF Eucalyptus grandis W. Mill ex Maiden TREES

ABSTRACT Climatic conditions stimulates the cambial activity of plants, and cause significant changes in trunk diameter growth and wood characteristics. The objective of this study was to evaluate the influence of climate variables in the diameter growth rate of the stem and the wood density of Eucalyptus grandis trees in different classes of the basal area. A total of 25 Eucalyptus trees at 22 months of age were selected according to the basal area distribution. Dendrometer bands were installed at the height of 1.30 meters (DBH) to monitor the diameter growth every 14 days, for 26 months. After measuring growth, the trees were felled and wood discs were removed at the DBH level to determine the radial density profile through x-ray microdensitometry and then re-scale the average values every 14 days. Climatic variables for the monitoring period were obtained and grouped every 14 days. The effect of the climate variables was determined by maximum and minimum growth periods in assessing trunk growth. These growth periods were related with precipitation, average temperature and relative air humidity. The re-scaled wood density values, calculated using the radial growth of the tree trunks measured accurately with steel dendrometers, enabled the determination of the relationship of small changes in wood density and the effect of the climatic variations and growth rate of eucalyptus tree trunks. A high sensitivity of the wood density to variation in precipitation levels was found.

Growth of hartweg’s pine ( Pinus hartwegii ) parasitized by two dwarf mistletoe species ( Arceuthobium spp.)

Coniferous forests occupy a large extent ( 7 %) of the Mexican territory. Within these forests, pines are a common and sometimes dominant component; however, several abiotic and biotic factors affect pines growth. Among the main biotic factors is the parasitic effect of dwarf mistletoes. In Zoquiapan (Iztaccíhuatl Popocatépetl National Park, Central Mexico) two dwarf mistletoe species coexist parasitizing Pinus hartwegii . The aim of this study was to know the effect of Arceuthobium globosum and A. vaginatum , either individually or as a pair, on P. hartwegii growth, allometric relations, and size susceptibility. We recorded diameter at breast height (dbh) and crown spread of P. hartwegii for 3 years on individuals infested by either one of the species, both, or none, as well as the infection severity. The relative growth rate (RGR) in diameter was strongly in uenced by the pines initial dbh; whereas the infecting species or severity did not show a differential effect. The allometric relation of dbh and height was affected by parasitism, where the trees infected by both species were shorter than the uninfected and infected by A. vaginatum at the same dbh. The parasitic effect does not differ among these mistletoe species. However, the host-size structure affects the presence and severity of infection; maintaining even-age stands provides a better scenario for a milder effect of parasitism, which should be considered for managing plans.

Mechanism of metal dusting corrosion by pitting of a chromia-forming alloy at atmospheric pressure and low gas velocity

FeNiCr samples (800HT) were exposed at 570°C, 1bar to a 47.25CO-47.25H2-5.5H2O atmosphere (ac=33) flowing at 18μm/s. Pitting corrosion was observed. Pits showed a flattened morphology and a constant pit diameter growth rate. Corrosion rings appeared successively at the surface during pit growth. A four-step mechanism is proposed which includes internal oxidation of carbides, graphitisation and localised enhanced graphitisation. Gas velocity and thermal cycling play key roles in pit morphology. Thermal cycling induces circular cracks. Low gas velocity induces the gas to evolve in crevices, due to local oxygen consumption.

Characterization of morphology and component of struvite pellets crystallized from sludge dewatering liquor: Effects of total suspended solid and phosphate concentrations

A lab-scale struvite pellet crystallization system was used to study phosphorus (P) removal and recovery from sludge dewatering liquor (SDL). Influences of total suspended solids (TSS) and phosphate concentrations on P removal as well as the size, morphology, purity, and components of struvite pellets were investigated. The increase in TSS concentration resulted in not only the decreases in phosphate removal efficiency and struvite purity but also the irregular pellet morphology and broken struvite crystals. Increasing inlet PO4-P concentration enhanced PO4-P removal, average struvite pellet diameter, purity and crystal volume growth rate. Amorphous calcium phosphate (ACP), calcite, brucite and magnesium phosphate were formed as co-precipitates with struvite. However, species and quantity of co-precipitates could be variable. More calcium precipitates were easily formed at lower PO4-P concentration (48mg/L), while brucite was the main co-precipitate at higher PO4-P concentration (151mg/L). Organic compounds were involved in struvite pellets along with suspended solids during the formation of struvite. Higher TSS concentration resulted in both more species and higher contents of organic compounds in struvite pellets. Therefore, it is essential to remove suspended solids in advance so as to obtain high P-removal and harvest high-quality struvite pellets.

Growth Performance of Three Indigenous Tree Species (Cratoxylum arborescens Vahl. Blume, Alstonia spathulata Blume, and Stemonurus scorpioides Becc.) Planted at Burned Area in Klias Peat Swamp Forest, Beaufort, Sabah, Malaysia

&lt;p&gt;The aim of the study was to evaluate the growth performance of three indigenous tree species planted under open area planting technique of burned area at Klias Peat Swamp Forest, Beaufort, Sabah. Three indigenous tree species was used in this study, namely are &lt;em&gt;Cratoxylum arborescens&lt;/em&gt; (Vahl) Blume (Geronggang), &lt;em&gt;Alstonia spathulata&lt;/em&gt; Blume (Pulai), and &lt;em&gt;Stemonurus scorpioides&lt;/em&gt; Becc. (Katok). A total of 45 seedlings for each species were examined using Randomized Complete Block Design (RCBD) with spacing of 3mx3m. Data collection for height, diameter, and survivality was recorded every two weeks within 10 weeks period from the seedlings was planted. Results from this study showed, the growth performance of Geronggang species was much better than the Pulai species, while all the Katok seedlings were died after week 6 in this experiment. The Geronggang species had the average mean height increment of 24.17 cm and average mean diameter increment of 2.76 mm, while Pulai species had average mean height increment of 9.36 cm and average mean diameter increment with 1.86 mm. For the survivality results, it showed that the Geronggang species had the highest survivality rate at 93.33% and Pulai species with 86.67%. There was a significant difference in term of relative height growth rate between Geronggang and Pulai species. However, there was no significant difference in term of relative diameter growth rate at significant level of P ≤ 0.05. The findings indicates that Geronggang and Pulai are suitable to be planted at burned area in Klias peat swamp forest for the purpose of reforestation using open area planting technique, while the Katok species is not suitable due to environment consideration. The better growth performance of the Geronggang and Pulai species are because they can easily adapted with the open area planting at the study site.&lt;/p&gt;

Effects of temperature, water activity and incubation time on fungal growth and aflatoxin B1 production by toxinogenic Aspergillus flavus isolates on sorghum seeds

Sorghum, which is consumed in Tunisia as human food, suffers from severe colonization by several toxigenic fungi and contamination by mycotoxins. The Tunisian climate is characterized by high temperature and humidity that stimulates mold proliferation and mycotoxin accumulation in foodstuffs. This study investigated the effects of temperature (15, 25 and 37°C), water activity (aw, between 0.85 and 0.99) and incubation time (7, 14, 21 and 28d) on fungal growth and aflatoxin B1 (AFB1) production by three Aspergillus flavus isolates (8, 10 and 14) inoculated on sorghum grains. The Baranyi model was applied to identify the limits of growth and mycotoxin production. Maximum diameter growth rates were observed at 0.99aw at 37°C for two of the isolates. The minimum aw needed for mycelial growth was 0.91 at 25 and 37°C. At 15°C, only isolate 8 grew at 0.99aw. Aflatoxin B1 accumulation could be avoided by storing sorghum at low water activity levels (≤0.91aw). Aflatoxin production was not observed at 15°C. This is the first work on the effects of water activity and temperature on A. flavus growth and AFB1 production by A. flavus isolates on sorghum grains.

Response of ice-damaged northern hardwood stands in northern New York

At three previously thinned, even-aged northern hardwood stands affected by the 1998 ice storm, we evaluated the responses of trees in plots given a rehabilitation treatment, and compared findings to adjacent untreated areas. In both the rehabilitated and untreated areas mortality seemed consistent with regional norms for northern hardwood stands. Trees that died after the storm had essentially complete crown loss due to ice loading, and 12% of living trees lost at least half of their crown. In both sets of plots, epicormic branching within the crown led to crown rebuilding, resulting in high levels of tree survival and good post-storm diameter growth on all plots. Release of selected upper-canopy trees by the rehabilitation cutting significantly increased diameter growth rates compared to those in untreated areas. While some epicormics developed below the base of the original crown in both treated and untreated plots, they largely emanated at &gt; 5.2 m from the ground and did not degrade the butt log of most trees.

In vitro toxic effects of heavy metals on fungal growth and phosphate-solubilising abilities of isolates obtained from Phragmites australis rhizosphere

ABSTRACT In this research, we evaluated the toxic effect of metal ions on mycelial growth and phosphate-solubilising activity of soil-borne micromycetes isolated from the Phragmites australis rhizosphere using Pikovskaya-agar plates supplemented with four metal concentrations. The diameter growth rate (DGR) decreased as the metal concentration rise for all tested fungi. Trichoderma atroviride had the fastest growth rate (1.48 cm2 day−1) and was the least susceptible to Al3+, Cd2+, Cr3+, Cu2+ and Pb2+ with a median effective concentration (MEC50) of 12.19, 0.48, 4.51, 11.44 and 50.05 mM, respectively. Aspergillus japonicus was the most tolerant to Co2+, Ni2+ and Zn2+, with MEC50 values of 3.36, 1.095 and 2.34 mM, respectively. Penicillium italicum was the most tolerant to Cr6+ (MEC50 = 0.677 mM). The ability to solubilise phosphate remained, despite the decrease in the DGR, and P. italicum and Penicillium dipodomyicola had the highest Phosphate Solubilisation Indexes (PSIs) at 1.97 and 2.12, respectively. In particular, P. italicum recorded the highest PSI of all the studied isolates at 0.62 mM Cr3+ (PSI = 4.74). A. japonicus and T. atroviride were the most tolerant isolates to all tested metals, which suggests that these isolates are promising candidates for further study with regard to mycoremediation and biofertilisation of metal-polluted soils.

Performance of Seedlings of a Shade-Tolerant Tropical Tree Species after Moderate Addition of N and P

Nitrogen deposition to tropical forests is predicted to increase in future in many regions due to agricultural intensification. We conducted a seedling transplantation experiment in a tropical premontane forest in Ecuador with a locally abundant late-successional tree species (Pouteria torta, Sapotaceae) aimed at detecting species-specific responses to moderate N and P addition and to understand how increasing nutrient availability will affect regeneration. From locally collected seeds, 320 seedlings were produced and transplanted to the plots of the Ecuadorian Nutrient Manipulation Experiment (NUMEX) with three treatments (moderate N addition: 50 kg N ha-1 yr-1, moderate P addition: 10 kg P ha-1 yr-1 and combined N and P addition) and a control (80 plants per treatment). After 12 months, mortality, relative growth rate, leaf nutrient content and leaf herbivory rate were measured. N and NP addition significantly increased the mortality rate (70 % vs. 54 % in the control). However, N and P addition also increased the diameter growth rate of the surviving seedlings. N and P addition did not alter foliar nutrient concentrations and leaf N:P ratio, but N addition decreased the leaf C:N ratio and increased SLA. P addition (but not N addition) resulted in higher leaf area loss to herbivore consumption and also shifted carbon allocation to root growth. This fertilization experiment with a common rainforest tree species conducted in old-growth forest shows that already moderate doses of added N and P are affecting seedling performance which most likely will have consequences for the competitive strength in the understory and the recruitment success of P. torta. Simultaneous increases in growth, herbivory and mortality rates make it difficult to assess the species’ overall performance and predict how a future increase in nutrient deposition will alter the abundance of this species in the Andean tropical montane forests.

The History of Incidentally Discovered Penetrating Aortic Ulcers of the Abdominal Aorta

The management of incidentally discovered penetrating ulcers of the abdominal aorta (PUAA) is not well described. A search of computed tomography (CT) angiography imaging reports for the words "penetrating ulcer" was performed from October 2010 to August 2011. Patients with a PUAA were identified, and their clinical course was followed through December 2014 (n=53). No specific intervention for the ulcers was sought unless additional aortic pathology necessitated intervention. Prospective and retrospective review of imaging was performed by dedicated vascular radiologists. Aortic diameters and ulcer dimensions were measured for patients with repeat imaging. Mann-Whitney U, Fisher's exact, and Pearson correlation coefficient tests were performed for statistical analysis. The calculated incidence of PUAA for patients undergoing CT imaging was 0.48%. Age at diagnosis was 71.6±10.5years in a population that included 35 (66.0%) males. Repeat imaging was performed for 29 (54.7%) patients. Median clinical and imaging follow-up was 36 (1-127) months and 34 (1-89) months. A history of hypertension (92.5%), hyperlipidemia (77.4%), and tobacco use (81.8%) was common. Twenty-seven (50.9%) had concomitant aneurysms not necessarily associated with PUAA. No aortic aneurysm or PUAA rupture occurred, but the population was sick with 19 patients (35.8%) deceased at the end of the study. Median aortic diameter growth rate through the PUAA was 0.5 (0-11.4) mm/year. No difference in mortality or aortic pathology was detected in patients with aortic growth rates >1mm/year compared with <1mm/year (P=0.21 and P=0.71, respectively). Patients with PUAA in general are elderly with multiple comorbidities. A large percentage of patients have concurrent, separate, aortic pathology, most frequently aortic aneurysms. Small changes in the appearance of the PUAA were frequent but did not equate with abdominal aortic catastrophe. Long-term mortality for this population was high, but the ulcer growth during follow-up did not suggest PUAA treatment would improve survival.

Dynamics of ultrafine particles inside a roadway tunnel

Size-segregated ultrafine particles from motor vehicles were investigated in the Craeybeckx tunnel (E19 motorway, Antwerp, Belgium) at two measurement sites, at 100 and 300m inside the tunnel, respectively, during March 2008. It was observed that out of the three size modes, nucleation, Aitken, and accumulation, Aitken mode was the most dominant size fraction inside the tunnel. The diurnal variation in ultrafine particle (UFP) levels closely follows the vehicular traffic inside the tunnel, which was maximum during office rush hours, both in the morning and evening and minimum during night-time around 3am. The tunnel data showed very high growth rates in comparison with free atmosphere. The average condensation sink during the growth period was 14.1-17.3×10(-2)s(-1). The average growth rate (GR) of geometric mean diameter was found to be 18.6±2.45nmh(-1). It was observed that increase in Aitken mode was related to the numbers of heavy-duty vehicles (HDV), as they emit mainly in the Aitken mode. The higher Aitken mode during traffic jams correlated well with HDV numbers. At the end of the tunnel, sudden dilution leading to fast coagulation was responsible for the sudden drop in the UFP number concentration.