bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian modelling disentangles language versus executive control disruption in stroke
Authors: Hartwigsen Gesa , Lim Jae-Sung , Bae Hee-Joon , Yu Kyung-Ho , Kuijf Hugo J , Weaver Nick A , Biesbroek J Matthijs , Kopal Jakub , Bzdok Danilo
Published: April 2024

Stroke is the leading cause of long-term disability worldwide. Incurred brain damage can disrupt cognition, often with persisting deficits in language and executive capacities. Yet, despite their clinical relevance, the commonalities and differences between language versus executive control impairments remain under-specified. To fill this gap, we tailored a Bayesian hierarchical modelling solution in a largest-of-its-kind cohort (1080 patients with stroke) to deconvolve language and executive control with respect to the stroke topology. Cognitive function was assessed with a rich neuropsychological test battery including global cognitive function (tested with the Mini-Mental State Exam), language (assessed with a picture naming task), executive speech function (tested with verbal fluency tasks), executive control functions (Trail Making Test and Digit Symbol Coding Task), visuospatial functioning (Rey Complex Figure), as well as verbal learning and memory function (Soul Verbal Learning). Bayesian modelling predicted interindividual differences in eight cognitive outcome scores three months after stroke based on specific tissue lesion topologies. A multivariate factor analysis extracted four distinct cognitive factors that distinguish left- and right-hemispheric contributions to ischaemic tissue lesions. These factors were labelled according to the neuropsychological tests that had the strongest factor loadings: One factor delineated language and general cognitive performance and was mainly associated with damage to left-hemispheric brain regions in the frontal and temporal cortex. A factor for executive control summarized mental flexibility, task switching and visual-constructional abilities. This factor was strongly related to right-hemispheric brain damage of posterior regions in the occipital cortex. The interplay of language and executive control was reflected in two distinct factors that were labelled as executive speech functions and verbal memory. Impairments on both factors were mainly linked to left-hemispheric lesions. These findings shed light onto the causal implications of hemispheric specialization for cognition; and make steps towards subgroup-specific treatment protocols after stroke.
Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry Analysis of Urinary Oligosaccharides and Glycoamino Acids for the Diagnosis of Mucopolysaccharidosis and Glycoproteinosis
Authors: Wongkittichote Parith , Cho Se Hyun , Miller Artis , King Kaitlyn , Herbst Zackary M , Ren Zhimei , Gelb Michael H , Hong Xinying
Published: April 2024

Background

Mucopolysaccharidosis (MPS) and glycoproteinosis are 2 groups of heterogenous lysosomal storage disorders (LSDs) caused by defective degradation of glycosaminoglycans (GAGs) and glycoproteins, respectively. Oligosaccharides and glycoamino acids have been recognized as biomarkers for MPS and glycoproteinosis. Given that both groups of LSDs have overlapping clinical features, a multiplexed assay capable of unambiguous subtyping is desired for accurate diagnosis, and potentially for severity stratification and treatment monitoring.

Methods

Urinary oligosaccharides were derivatized with 3-methyl-1-phenyl-2-pyrazoline-5-one (PMP) and analyzed by ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) together with the underivatized glycoamino acids. Novel biomarkers were identified with a semi-targeted approach with precursor mass scanning, the fragmentation pattern (if applicable), and the biochemical basis of the condition.

Results

A UPLC-MS/MS analysis with improved chromatographic separation was developed. Novel biomarkers for MPS-IIIA, IIIB, IIIC, and VII were identified and validated. A total of 28 oligosaccharides, 2 glycoamino acids, and 2 ratios were selected as key diagnostic biomarkers. Validation studies including linearity, lower limit of quantitation (LLOQ), and precision were carried out with the assay performance meeting the required criteria. Age-specific reference ranges were collected. In the 76 untreated patients, unambiguous diagnosis was achieved with 100% sensitivity and specificity. Additionally, the levels of disease-specific biomarkers were substantially reduced in the treated patients.

Conclusions

A multiplexed UPLC-MS/MS assay for urinary oligosaccharides and glycoamino acids measurement was developed and validated. The assay is suitable for the accurate diagnosis and subtyping of MPS and glycoproteinosis, and potentially for severity stratification and monitoring response to treatment.
The influence of transcatheter aortic valve replacement on left atrial mechanics: a systematic review and meta-analysis
Authors: Meredith Thomas , Brown Lauren , Mohammed Farhan , Pomeroy Amy , Roy David , Muller David W M , Hayward Christopher , Feneley Michael , Namasivayam Mayooran
Published: April 2024

Aims

The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. Data pertaining to the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry are scarce. The aim of the study was to quantify associations between TAVR and LA remodelling by pooling available data from published observational studies.

Methods and results

A systematic review and meta-analysis were performed. Studies reporting serial LA speckle-tracking echocardiographic (STE) data, before and after TAVR, were included. Other outcome data included LA area and indexed volume (LAVi) and standard chamber measurements. Outcomes were stratified by timing of follow-up echocardiography: early (<6 months) or late (≥6 months). Twelve studies were included, comprising 1066 patients. The mean reduction in LAVi was 2.72 mL/m2 [95% confidence interval (CI) 1.37–4.06, P < 0.01]. LA reservoir function improved overall by a mean difference (MD) of 3.71% (95% CI 1.82–5.6, P < 0.01), although there was significant heterogeneity within the pooled studies (I2 = 87.3%). Significant improvement in reservoir strain was seen in both early follow-up (MD 3.1%, P < 0.01) and late follow-up studies (MD 4.48%, P = 0.03), but heterogeneity remained high (I2 = 65.23 and 94.4%, respectively). Six studies reported a change in LA contractile function, which recovered in the early follow-up studies (MD 2.26, P < 0.01), but not in the late group (MD 1.41, P = 0.05). Pooled improvement in LA booster function was 1.96% (95% CI 1.11–2.8, P < 0.01).

Conclusion

TAVR is associated with significant negative LA remodelling, and an improvement in LA mechanics, quantified by STE. The prognostic implications of these findings require further study.
A single-centre analysis of lung transplantation outcomes in recipients aged 70 or older
Authors: Kashem Mohammed Abul , Calvelli Hannah , Warnick Michael , Kehara Hiromu , Dulam Vipin , Zhao Huaqing , Yanigada Roh , Shigemura Norihisa , Toyoda Yoshiya
Published: April 2024

OBJECTIVES

As life expectancies continue to increase, a greater proportion of older patients will require lung transplants (LTs). However, there are no well-defined age cutoffs for which LT can be performed safely. At our high-volume LT centre, we explored outcomes for LT recipients ≥70 vs <70 years old.

METHODS

This is a retrospective single-centre study of survival after LT among older recipients. Data were stratified by recipient age (≥70 vs <70 years old) and procedure type (single versus double LT). Demographics and clinical variables were compared using Chi-square test and 2 sample t-test. Survival was assessed by Kaplan–Meier curves and compared by log-rank test with propensity score matching.

RESULTS

A total of 988 LTs were performed at our centre over 10 years, including 289 LTs in patients ≥70 years old and 699 LTs in patients <70 years old. The recipient groups differed significantly by race (P < 0.0001), sex (P = 0.003) and disease aetiology (P < 0.0001). Older patients were less likely to receive a double LT compared to younger patients (P < 0.0001) and had lower rates of intraoperative cardiopulmonary bypass (P = 0.019) and shorter length of stay (P = 0.001). Both groups had overall high 1-year survival (85.8% vs 89.1%, respectively). Survival did not differ between groups after propensity matching (P = 0.15).

CONCLUSIONS

Our data showed high survival for older and younger LT recipients. There were no statistically significant differences observed in survival between the groups after propensity matching, however, a trend in favour of younger patients was observed.
Performance of left internal thoracic artery-left anterior descending artery anastomosis by residents versus attendings and coronary artery bypass grafting outcomes
Authors: Gikandi Ajami , Stock Eileen , DeMatt Ellen , Hirji Sameer , Awtry Jake , Quin Jacquelyn A , Tolis George , Biswas Kousick , Zenati Marco A
Published: April 2024

OBJECTIVES

Performance of a technically sound left internal thoracic artery to left anterior descending artery (LITA-LAD) anastomosis during coronary artery bypass grafting (CABG) is critically important. We used prospectively collected data from the multicentre, randomized REGROUP (Randomized Endograft Vein Perspective) trial to investigate CABG outcomes based on whether a resident or an attending surgeon performed the LITA-LAD anastomosis.

METHODS

This was a post hoc subanalysis of the REGROUP trial, which randomized veterans undergoing isolated on-pump CABG to endoscopic versus open vein harvest from 2014 through 2017. The primary end point was major cardiac adverse events, defined as the composite of all-cause deaths, nonfatal myocardial infarctions or repeat revascularizations.

RESULTS

Among 1,084 patients, 344 (31.8%) LITA-LAD anastomoses were performed by residents and 740 (68.2%), by attending surgeons. Residents (compared to attendings) operated on fewer patients with high tercile SYNTAX scores (22.1% vs 37.4%, P < 0.001), performed fewer multiarterial CABGs (5.2% vs 14.6%, P < 0.001) and performed more anastomoses to distal targets with diameters > 2.0 mm (19.0% vs 10.9%, P < 0.001) and non-calcified landing zones (25.1% vs 21.6%, P < 0.001). During a median observation time of 4.7 years (interquartile range 3.84–5.45), major cardiac adverse events occurred in 77 patients (22.4%) in the group treated by residents and 169 patients (22.8%) in the group treated by attendings (unadjusted HR 1.00; 95% confidence interval, 0.76–1.33; P = 0.99). Outcomes persisted on adjusted analyses.

CONCLUSIONS

Based on this REGROUP trial subanalysis, under careful supervision and with appropriate patient selection, LITA-LAD anastomoses performed by the residents yielded clinical outcomes similar to those of the attendings.
‘Working me to life’: longitudinal perceptions from adults with heart failure with preserved ejection fraction enrolled in an exercise training clinical trial
Authors: Salahshurian Erin , Pozehl Bunny J , Lundgren Scott W , Bills Sara , Pandey Ambarish , Carbone Salvatore , Alonso Windy W
Published: April 2024

Aims

Adults with heart failure with preserved ejection fraction (HFpEF) responded more favourably to an exercise intervention compared with those with reduced ejection fraction. This study explores factors that contributed to this response, focusing on the qualitative perceptions of adults with HFpEF enrolled in an exercise intervention.

Methods and results

This qualitative descriptive study is a secondary analysis of longitudinal interviews collected at 3, 6, 12, and 18 months from participants with HFpEF enrolled in a randomized controlled trial testing an intervention to promote adherence to exercise. We included participants with at least two interviews. Interviews were examined across and within participants and time points using thematic analysis. Analyses included 67 interviews from 21 adults with HFpEF enrolled in the intervention arm. The sample consisted of 52% (11/21) males and over 47% (10/21) non-White participants. Mean age at enrolment was 63.7 ± 9.9 years. We identified four major themes: (1) overcoming negative attitudes, barriers, and injury, (2) motivations to exercise, (3) exercise—the panacea for HFpEF symptoms and quality of life, and (4) advice for others with HFpEF.

Conclusion

Our findings suggest that for many adults with HFpEF, initial hesitancy, fear, and negative attitudes about exercise can be overcome. Exercise coaching using social cognitive constructs, medical fitness centre memberships, and heart rate self-monitoring are successful strategies of engaging adults with HFpEF in long-term unsupervised exercise training.

Registration

ClinicalTrials.gov, NCT01658670.
Impact of atrial fibrillation phenotype and left atrial volume on outcome after pulmonary vein isolation
Authors: Chollet Laurève , Iqbal Salik ur Rehman , Wittmer Severin , Thalmann Gregor , Madaffari Antonio , Kozhuharov Nikola , Galuszka Oskar , Küffer Thomas , Gräni Christoph , Brugger Nicolas , Servatius Helge , Noti Fabian , Haeberlin Andreas , Roten Laurent , Tanner Hildegard , Reichlin Tobias
Published: April 2024

Aims

Pulmonary vein isolation (PVI) is increasingly performed in patients with atrial fibrillation (AF). Both AF phenotype and left atrial (LA) volume have been shown to influence ablation outcome. The inter-relationship of the two is incompletely understood. We aimed to investigate the impact of AF phenotype vs. LA volume on outcome after PVI.

Methods and results

In a retrospective analysis of a prospective registry of patients undergoing a first PVI, the association of AF phenotype and LA volume index (LAVI) was assessed as well as their impact on AF recurrence during follow-up. Overall, 476 patients were enrolled (median age 63 years, 29% females, 65.8% paroxysmal AF). Obesity, hypertension, chronic kidney disease, and heart failure were all significantly more frequent in persistent AF. After 1 year, single-procedure, freedom from arrhythmia recurrence was 61.5%. Patients with paroxysmal AF had better outcomes compared with patients with persistent AF (65.6 vs. 52.7%, P = 0.003), as had patients with no/mild vs. moderate/severe LA dilation (LAVI <42 mL/m2 67.1% vs. LAVI ≥42 mL/m2 53%, P < 0.001). The combination of both parameters refined prediction of 1-year recurrence (P < 0.001). After adjustment for additional clinical risk factors in multivariable Cox proportional hazard analysis, both AF phenotype and LAVI ≥42 mL/m2 contributed significantly towards the prediction of 1-year recurrence.

Conclusion

Atrial fibrillation phenotype and LA volume are independent predictors of outcome after PVI. Persistent AF with no/mild LA dilation has a similar risk of recurrence as paroxysmal AF with a moderate/severe LA dilation and should be given similar priority for ablation.
Insects and Leaf Area Losses of Planted Northern Red Oak Seedlings in an Ozark Forest
Authors: Linit M. J. , Johnson P. S. , McKinney R. A. , Kearby W. H.
Published: April 2024

Insects representing 25 families from six orders were associated with northern red oak (Quercus rubra L.) seedlings planted in clearcut and partially cut plots. Most insect taxa were equally represented in both plot types. However, three of the most abundant insects were found in only one plot type: Cyrtepistomus castaneus (Roelofs) and Limonius spp. in partial cuts and Attelabus bipustulatus Fabricius in clearcuts. Linear regression equations were derived for estimating leaf area before defoliation from either leaf length or petiole diameter. Oak seedlings in clearcuts had twice the number of leaves and potential standing leaf area as seedlings in partial cuts throughout the growing season. Leaf area losses in both overstory types averaged about 22 percent of potential standing leaf area by 30 October. Forest Sci. 32:11-20.
Oak Regeneration After Clear Felling in Southwest Virginia
Authors: Ross Michael S. , Sharik Terry L. , Smith David Wm.
Published: April 2024

Oak advance regeneration and stump sprouts were studied during a 2- to 3-year period after clear felling and whole-tree removal in ten midslope stands in the Ridge and Valley Physiographic Province of southwest Virginia. Site quality ranged from poor (oak site index 8-16 m, base age 50) to medium (site index 17-22 m). Chestnut oak was the dominant oak species in most pre-harvest stands. Two years after clear felling, chestnut oak also had a higher density of advance regeneration, a higher frequency of stump sprouting, and greater sprout growth per stump than scarlet or black oak. However, shoot growth of advance regeneration following clear felling did not differ among oak species after correcting for initial stem size and vigor. Both height increase and diameter growth of oak advance regeneration during the 2-year post-harvest period were significantly greater on medium sites than on poor sites, and stump sprouts were taller on medium sites. Regression equations for predicting 2-year stump sprout growth from characteristics of the parent tree usually explained less than 40 percent of the variation among stumps, while equations for predicting 2-year growth of advance regeneration from pre-harvest measurements accounted for as much as 82 percent of total variation. Density of well-established oak advance regeneration 3 years after clear felling was greatest in stands of site index 17-20 m, and decreased on both better and poorer sites. The success of advance oak regeneration following clear felling was most highly correlated with pre-harvest advance regeneration density when small stems (i.e., <30 cm tall) as well as larger stems were included in the pre-harvest inventory. Forest Sci. 32: 157-169.
Estimates of Genetic Parameters for Deer Browsing of Douglas-fir
Authors: Silen Roy R. , Randall William K. , Mandel Nancy L.
Published: April 2024

This report evaluates genetic variation in wintertime deer browsing among full-sib families of Douglas-fir. Cuttings of 10-year-old progeny of a mating of six trees as females crossed with 11 trees as males provided estimates of heritability, combining ability, and genetic gain in browsing resistance. Open-pollinated progeny and cuttings from parent trees were also included in the study. An average of 46 percent of the cuttings were browsed after 38 days exposure. Browsing among seedling families ranged from 39 to 69 percent. Sixty-five percent of the total genetic variation was additive. Reciprocal, maternal, and specific combining ability components were nonsignificant. Family heritability was estimated at 0.73. Gain per generation, based on selecting 10 percent of the most resistant families, was estimated at 11 percent. Forest Sci. 32:178-184.
Characterizing Diameter Distributions with Modified Data Types and Forms of the Weibull Distribution
Authors: Zutter B. R. , Oderwald R. G. , Murphy P. A. , Farrar R. M.
Published: April 2024

Complete, left censored, and left truncated data fitted with a two-parameter complete Weibull distribution were compared for characterizing complete diameter distributions. The complete data provided the best fit, followed by the censored and truncated data. As the intensity of censoring and truncation increased distribution description was generally poorer. The use of left truncated data was judged unacceptable. Left censored data appears to be a reasonable alternative to complete data. In field applications collection of left censored data would reduce measurement time. Complete, left censored, and left truncated data fitted with a two-parameter complete Weibull and left truncated data fitted with a two-parameter left truncated Weibull were compared for characterizing left truncated diameter distributions. The left truncated data fitted with a left truncated Weibull performed best, but no data type-distribution combination worked well for inverse j-shape distributions. Forest Sci. 32:37-48.
Complex Compatible Taper and Volume Estimation Systems for Red and Loblolly Pine
Authors: Byrne John C. , Reed David D.
Published: April 2024

Five equation systems are described which can be used to estimate upper stem diameter, total individual tree cubic-foot volume, and merchantable cubic-foot volumes to any merchantability limit (expressed in terms of diameter or height), both inside and outside bark. The equations provide consistent results since they are mathematically related and are fit using stem analysis data from plantation-grown red and loblolly pine. Comparisons are made to determine which equation system provides the best overall fit to a set of validation data for each species. Results indicate that a system based on a segmented taper equation outperformed all other systems for both species. Forest Sci. 32:423-443.
Simulation Studies on Line Intersect Sampling of Forest Residue, Part II
Authors: Hazard John W. , Pickford Stewart G.
Published: April 2024

A simulation study was conducted to establish the statistical properties of line intersect sampling of forest residue on cable-logged and tractor-logged populations. These two distinctly patterned populations were described and reproduced in the computer by mathematical functions. Systematic grid sampling of clusters of one, two, and three lines with random and systematic orientation was performed.

Three sampling allocation strategies were used to compare systematic grid sampling with random sampling; one-, two-, and three-line clusters; and systematic orientation with random orientation. The strategies studied were maximum precision for fixed total cost, fixed total length of transect, and fixed number of sample points (line clusters).

The authors recommend systematic grid sampling of forest residues from cable logging. Either two- or three-line clusters at each grid point (line orientations of 90 or 120 degrees, respectively) axe most efficient: two-line clusters for controlling precision when total cost and total transect length are fixed; three-line clusters when the number of grid points is fixed.

For sampling tractor-logged residues with a fixed total length of transect, we recommend sampling with one randomly located and oriented transect line per sample point. Otherwise, we recommend systematic sampling with two or three lines (at 90 and 120 degrees, respectively). Lines should be randomly oriented. Three lines are recommended for a strategy of fixed number of sample points, and two lines for a fixed cost strategy. Forest Sci. 32:447-470.
Regeneration and Growth After Logging Florida Pondcypress Domes
Authors: Terwilliger Valery J. , Carter Ewel Katherine
Published: April 2024

Recovery of vegetation after logging 16 small (1-5 ha), undrained pondcypress domes in north central Florida was analyzed. One dome was undisturbed and the others had been logged from a few months to 45 years before the study began. Densities of young (<2 yr old) pondcypress (Taxodium distichum var. nutans (Ait.) Sweet) were higher in domes that were recently logged than in older domes, whereas densities of other young woody plants were similar regardless of when a dome had been logged. Pondcypress saplings were significantly more abundant in domes logged 3 years before the study, and had sprouted after the domes were logged. There were no striking differences in canopy composition between older (15-45 yr) logged domes and historical descriptions of unlogged domes. In general, no differences in tree species composition (importance values, relative and absolute densities, frequencies and dominances of major species, and species diversity) were found among the domes. Also, selective logging did not result in a growth release among remaining trees. Over a period of 45 years or less, pondcypress domes appeared to recover their original basal area and dominance after selective logging and clearcutting. Forest Sci. 32: 493-506.
Lateral Root Morphology as an Expression of Sweetgum Seedling Quality
Authors: Kormanik Paul P.
Published: April 2024

Sweetgum seedlings from four open pollinated mother trees were grown in nursery beds infested with one of four vesicular-arbuscular mycorrhizal (VAM) fungi, and with available soil P levels (Bray II) adjusted to 50 ppm. Comparable beds had no VAM fungi present but had their available soil P levels adjusted to about 75, 100, 200, and 300 ppm. When lifted, the seedlings were placed in one of three morphological grades based upon number of permanent lateral roots exceeding 1 mm in diameter: Grade 1 seedlings had more than six roots; grade 2 between four and six roots; grade 3 had fewer than four roots. Approximately 50 percent of all seedlings fell within the inferior root grade 3 classification. Nursery mycorrhizal condition and phosphorus fertilization had no affect upon lateral root morphology of seedlings from the four seedlots. No significant biological differences in seedling heights were observed among the different root grades at lifting but root collar diameter (RCD) varied significantly among the grades in order: grade 1 > grade 2 > grade 3. One year after outplanting, effects of root grade were significant for both height and RCD: grade 1 > grade 2 > grade 3. Early first year seedling dieback and first year survival varied significantly among grades. Dieback percentages for grades 1, 2, and 3 were 41, 67, and 89 percent; survival averages for grades 1, 2, and 3 were 79, 67, and 51 percent. These data suggest that number of lateral roots on a sweetgum nursery seedling is an indicator of probable performance after outplanting. Forest Sci. 32:595-604.
Clearcutting Northern Hardwoods: Effects on Hydrologic and Nutrient Ion Budgets
Authors: Hornbeck J. W. , Martin C. W. , Pierce R. S. , Bormann F. H. , Likens G. E. , Eaton J. S.
Published: April 2024

Two evenaged management systems, progressive strip cutting and block clearcutting, have been studied since 1970 on small watersheds at the Hubbard Brook Experimental Forest, New Hampshire. In the progressive strip cutting, all merchantable trees were harvested in a series of three strips over 4 years (1970-74). In the block clearcutting, all trees were harvested in a single operation in 1970. Block cutting caused an increase in water yield of 673 mm over 10 years compared to an increase of 397 mm for strip cutting. Maximum annual increases were 278 mm in the first year after block cutting versus 114 mm in the third year of the strip cutting sequence (two-thirds of watershed harvested). Nearly all of the increases on both watersheds occurred during the growing season months of June through September. For the 10-year period after strip cutting, nutrients lost as dissolved ions in streamflow were increased by 27 kg ha-1 for Ca2+, 30 kg ha-1 for K+, and 22 kg ha-1 for N. Corresponding increases after block clearcutting were 40 kg ha-1; for Ca2+, 48 kg ha-1 for K+, and 59 kg ha-1 for N. The combined losses of nutrients to product removal and increased leaching did not exceed 3 percent of preharvest capital for any of the nutrients studied. The losses assume greater importance when contrasted with plant-available capitals of nutrients. However, with careful logging and continued use of intervals of 70 to 120 years between harvests, clearcutting of northern hardwoods should not have adverse impacts on site nutrient capital. Forest Sci. 32:667-686.
A Growth Model for Mixed Species Stands
Authors: Lynch Thomas B. , Moser John W.
Published: April 2024

A technique for predicting stand tables for each of two species groups in a mixed species stand was developed. Future stand conditions for each species group are determined by integrating a system of differential equations which relate rates of change in per acre values of basal area, sum of diameters, and numbers of trees to current amounts of basal area, sum of diameters, and numbers of trees. Solutions to the system at future times include estimates of basal area, sum of diameters, and number of trees for each species group. Parameter recovery is used to obtain the Weibull diameter distribution parameters for each species group, which are used to develop predicted stand tables. Forest Sci. 32:697-706.
A Nonlinear Programming Approach to Stand Optimization
Authors: Roise Joseph P.
Published: April 2024

The stand management decision problem is formulated as a constrained nonlinear program. Constraints inherent to the production system are part of the production function and can be incorporated into the objective function. If there are no constraints from external sources the problem is an unconstrained nonlinear program. Three nonlinear programming (NP) techniques and discrete dynamic programming (DP) are compared for their relative efficiency in solving an example problem. The three NP techniques are the simplex method of Nelder and Mead, Hook and Jeeves' method, and Powell's method. Hook and Jeeves' and Powell's method are computationally more efficient techniques. Discrete DP optima did not compare favorably with NP optima. Forest Sci. 32:735-748.
Uptake and Phytotoxicity of Selenium in Black Cherry and White Ash Seedlings
Authors: Angradi Theodore R. , Tzilkowski Walter M.
Published: April 2024

Uptake and phytotoxicity of soil-applied sodium selenite in black cherry (Prunus serotina Ehrh.) and white ash (Fraxinus americana L.) seedlings were evaluated in a greenhouse study. For both species, foliar concentration of selenium was positively related to treatment level and elapsed time from treatment. Selenium toxicity was observed at all treatment levels in both species. Fifty percent mortality occurred at foliar Se concentrations exceeding 10 and 90 ppm dry weight basis in black cherry and white ash, respectively. At soil treatment levels > 10 ppm Se, dry weight basis, cherry diameter growth was reduced. Forest Sci. 32:806-811.
Evaluating the Efficiency of Even-Aged and Uneven-Aged Stand Management
Authors: Haight Robert G.
Published: April 2024

The first part of this paper describes a general investment model for stand management. The objective of the model is to find the sequences of diameter-class harvesting rates and planting intensities that maximize the present value of an existing stand. Since the model includes the problems of converting the initial stand to plantation management and converting the stand to steady-state uneven-aged management as special cases, the model provides a unifying framework for comparing three measures of management system efficiency: forest value, land expectation value, and managed forest value. When maximum present value is the efficiency criterion, forest value, which measures the present value of conversion and steady-state management for both even-aged and uneven-aged systems, is the correct measure for evaluating the efficiency of these systems. Determining the most efficient system by comparing land expectation values is correct in a special case. Managed forest value measures the present value of steady-state management and should not be used to evaluate the efficiency of management systems that include both conversion and steady-state management policies. In the second part of the paper, the investment model is coupled with equations for recruitment, growth, and valuation developed for ponderosa pine (Pinus ponderosa Laws.) in Arizona to demonstrate that gradient techniques can be used to solve for optimal harvesting and planting regimes. The case study emphasizes that, in general, constrained management regimes that involve clearcutting and planting are suboptimal relative to the optimal solution to the more general investment model, which may involve selection harvesting and uneven-aged management. For. Sci. 33(1):116-134.
Efficient Specification and Solution of the Even-aged Rotation and Thinning Problem
Authors: Paredes V. Gonzalo L. , Brodie J. Douglas
Published: April 2024

Dynamic programming is frequently used for stand level optimization. In recent years, solution methods have been made available for a number of growth models. However, increasingly complex growth models require network specifications with high dimensionality and its associated high computational cost.

This paper presents a more efficient solution algorithm that overcomes the computational burdens of the traditional dynamic programming approach. The algorithm is described using LaGrange multipliers and network theory.

An illustrative example is presented, and the computational efficiency of the new method is demonstrated by comparing its performance with an existing dynamic programming algorithm. The scope of applicability of the proposed method is discussed as well as aspects requiring further analysis and research. For. Sci. 33(1):14-29.
Compatible Basal Area and Diameter Distribution Models for Thinned Loblolly Pine Plantations in Santa Catarina, Brazil
Authors: McTague John P. , Bailey Robert L.
Published: April 2024

A simultaneous basal area growth and yield model based on diameter percentiles is developed. It is suggested that the diameter distribution percentiles essentially provide a description of the past stand history. The subsequent growth of a thinned or unthinned stand is affected by the shape and position of the diameter distribution percentiles. A noniterative technique is demonstrated for recovering the Weibull distribution parameters and generating a diameter distribution consistent with basal area. For. Sci. 33(1):43-51.
Plant—Water Relationships and Growth of Black Walnut in a Walnut-Forage Multicropping Regime
Authors: Dey D. , Conway M. R. , Garrett H. E. , Hinckley T. S. , Cox G. S.
Published: April 2024

Eastern black walnut seedlings were planted on a 1.5 x 1.5 m spacing in the spring of 1976 and irrigated throughout the growing season. During the spring of 1977, forage plots consisting of Kentucky 31 tall fescue, orchard grass, or Kobe lespedeza measuring 1 m wide and 10.2 m long and centered on a row of trees, were established with and without irrigation. Soil-water relationships measured throughout the 1977 growing season demonstrated lower Ψs, on the average, in irrigated than in nonirrigated plots during drought periods. Differences were attributed to the greater physiological vigor, thus greater transpiration, of forages growing under irrigated conditions. At the 45 cm depth, Ψs dropped to a low during August of -3.0 MPa with irrigation and only -0.8 MPa without. Predawn xylem pressure potentials of walnut seedlings however, were consistently lower on forage plots without irrigation. Significant decreases in dry weights of walnut grown with forages were associated with reductions in Ψ1 and increases in anthracnose infection. For. Sci. 33(1):70-80.
Response of Longleaf, Sand, and Loblolly Pines to Pisolithus Ectomycorrhizae and Fertilizer on a Sandhills Site in South Carolina
Authors: Hatchell Glyndon E. , Marx Donald H.
Published: April 2024

Barefoot seedlings were established on a deep sandy soil to test the responses of three pine species with ectomycorrhizae formed by Pisolithus tinctorius (Pt) or naturally occurring fungi in the nursery and with one of three fertilizer treatments applied during planting. Longleaf pine (Pinus palustris Mill.) had better survival and growth with Pt through seven growing seasons, but the effect of fertilizer was not significant for either ectomycorrhizal condition. Pisolithus tinctorius significantly increased the percentage of longleaf seedlings in active height growth after 3 years. Pisolithus tinctorius significantly improved growth of Choctawhatchee sand pine (P. clausa var. immuginata D. B. Ward) through 4 growing seasons, but survival of this species exhibited a significant interaction of ectomycorrhizal and fertilizer treatments. Pisolithus tinctorius significantly improved survival and growth of loblolly pine (P. taeda L.) only in the first growing season, and this species responded significantly to fertilizer in terms of increased survival and early growth. Ranking of 3- to 7-year growth of the three species was sand pine > loblolly pine > longleaf pine. Longleaf and Choctawhatchee sand pines, which are well adapted to sandy sites and are resistant to fusiform rust infection, are good choices for planting on deep sandy soils in the South Carolina sand-hills. For. Sci. 33(2):301-315.
Factors Influencing the Timber Harvest Intentions of Nonindustrial Private Forest Owners
Authors: Young Robert A. , Reichenbach Michael R.
Published: April 2024

Intentions of woodland owners to harvest timber were examined in an effort to increase understanding of the factors that influence wood production on nonindustrial private forests. Six-hundred-twenty-one randomly selected woodland owners were interviewed by telephone to determine their attitude and beliefs about harvesting timber, and the influence of "important others" in making harvest decisions. Responses were compared for those owners who intended to harvest timber within the next 10 years with those who had no intention to harvest. Attitudes and subjective norms accurately predicted intentions to harvest (R = .75). Standard regression coefficients indicate that intentions were more influenced by the owner's attitude than by the influence of social groups. Differences in beliefs and in the influence of social groups were observed between those who intended to harvest and those respondents who did not. Recommendations are made that would increase the number of owners who intend to produce wood products from their private woodlands. For. Sci. 33(2):381-393.
Production and Cost of Scenic Beauty: Examples for a Ponderosa Pine Forest
Authors: Brown Thomas C.
Published: April 2024

Psychophysical models of scenic b eauty for an all-aged ponderosa pine area were combined with estimates of management costs and physical output values to indicate more efficient input combinations for production of scenic beauty. Also, in combination with biophysical models, the scenic beauty models were used to examine tradeoffs between scenic beauty and net present worth from timber, forage, and water yields. These examples demonstrate the use, as well as important limitations, of scenic beauty models in a multiple use context. For. Sci. 33(2):394-410.
Efficient Unbiased Tree-Volume Estimation
Authors: Van Deusen Paul C. , Lynch Thomas B.
Published: April 2024

Two unbiased methods for estimating the volume of an individual tree are examined. One method is based on importance sampling and has been discussed by Gregoire et al. (1986). The other method is a logical extension of critical height sampling, which was first discussed by Kitamura (1962). The two methods are compared using a simple model for tree taper. When independent samples are drawn, the critical height method requires an inordinate sample size. However, when a negative correlation is induced in the sample observations using antithetic variates, both methods become much more efficient. The conclusion is that antithetic variates should be considered when taking multiple observations with either of these methods for unbiased tree volume estimation. For. Sci. 33(2):583-590.
A Stem Dissection Technique for Dating Branch Mortality and Reconstructing Past Crown Recession
Authors: MaGuire Douglas A. , Hann David W.
Published: April 2024

A stem dissection technique for dating branch mortality and estimating past crown recession was evaluated on 28 Douglas-fir trees from permanent plots in Oregon and Washington. Repeated height to live crown measurements over the past 15 years on each of the 28 trees provided a basis for comparison with the branch mortality dating technique. After each tree was felled in a scheduled thinning, heights to 10-15 consecutive branch whorls below crown base were measured. Sections containing the whorls were then removed and dissected on a band saw to expose longitudinal sections through the encased dead branches. Discontinuities between branch and bole growth rings, corresponding to the delineation between tight and loose knot zones, allowed estimation of years since branch mortality. Past heights to live crown were reconstructed from the branch mortality estimates and whorl heights. Backdated crown base positions corresponded closely with the 15-yr field remeasurements. For. Sci. 33(4):858-871.
Fixed and Equilibrium Endpoint Problems in Uneven-Aged Stand Management
Authors: Haight Robert G. , Getz Wayne M.
Published: April 2024

Studies in uneven-aged management have concentrated on the determination of optimal steady-state diameter distribution harvest policies for single and mixed species stands. To find optimal transition harvests for irregular stands, either fixed endpoint or equilibrium endpoint constraints can be imposed after finite transition periods. Penalty function and gradient methods are presented to solve these problems. The methods are demonstrated with a stage-structured model for projecting stands that contain mixtures of California white fir (Abies concolor [Gord. & Glend.] Lindl. (Iowiana [Gord.])) and red fir (Abies magnifica A. Murr.). With present value as the efficiency criterion, optimal transition strategies are computed for three kinds of target steady states: the extremal steady state associated with an infinite time horizon dynamic optimization problem, an investment-efficient steady state, and a maximum sustainable rent steady state. Harvest regimes that convert to investment-efficient or maximum sustainable rent steady states are dominated by red fir and are suboptimal compared to transition regimes that convert to the extremal steady state, which includes only white fir. The fixed endpoint regimes are compared with transition strategies that are obtained with equilibrium endpoint constraints that do not require a particular steady-state stand structure. Transition regimes that convert to the extremal steady state are suboptimal compared to regimes that solve the more general equilibrium endpoint problem, and the present values of these two kinds of regimes converge as the transition period lengthens. The species composition and structure of the steady states found by solving the equilibrium endpoint problem depend on the transition period length. For. Sci. 33(4):908-931.
Effects of Aeriai Detection Schedules on the Age of Southern Pine Beetle Infestations
Authors: de Steiguer J. E. , Hedden Roy L.
Published: April 2024

A method for scheduling southern pine beetle detection flights was developed and implemented as a computer program entitled OVERFLIGHT. The program determines the seasonal arrangement of flights that minimizes spot age, and therefore, forest damage, at the time of detection. The only data input to the program are the percentage of annual spots initiated in each month. These data were obtained from state pest control officers and the methodology applied to two regions of the South. The results indicate the best seasonal positioning of flights. Also, incremental flights showed decreasing marginal gains in reducing spot age with little improvement beyond five flights per year. Assumptions of the model are discussed, as well as use of the model in economic analyses. For. Sci. 34(1):229-235.
Ontogenetic Patterns of CO2 Exchange of Quercus rubra L. Leaves During Three Flushes of Shoot Growth II. Insertion Gradients of Leaf Photosynthesis
Authors: Hanson P. J. , Isebrands J. G. , Dickson R. E. , Dixon R. K.
Published: April 2024

Carbon dioxide exchange rates (CERs) of all leaves along the stem of northern red oak (Quercus rubra L.) seedlings (a leaf insertion gradient or profile) were determined at several stages of ontogeny. Seedlings were grown and measured under growth chamber conditions favorable for the production of multiple flushes of shoot growth. The CERs were measured with a portable closed-circuit CO2 analyzer at ambient photosynthetic photon flux densities and were determined for every leaf of each seedling. Carbon dioxide exchange rates per unit projected area of individual leaves (CERA) increased along leaf-maturation gradients in expanding flushes. After flush growth was completed, all leaves of a flush has similar CERA. However, because median flush leaves were the largest, they accounted for the greatest proportion of an expanded-flush's CER. First-flush leaves were the major contributors to total seedling CER through the second flush of growth—encompassing half of the period required to produce a three-flush oak seedling. This study's data, based on short-term CER measurements, showed ontogenetic patterns of CO2 exchange similar to those reported for northern red oak under "steady state" laboratory conditions. For. Sci. 34(1):69-76.
Site Preparation Effects on Soil Moisture and Available Nutrients in a Pine Plantation in the Florida Flatwoods
Authors: Burger J. A. , Pritchett W. L.
Published: April 2024

Burning and mechanical preparation of cutover forest sites enhances pine plantation establishment, but soil and site changes in southeastern forests have not been well documented. Two site-preparation treatments (burned-chopped and burned-bladed-harrowed-bedded) were applied to plots on a Florida flatwoods site. Harvesting caused a rise in the water table, and during the drier times of the year, the more intensively prepared plots had a higher water table than the chopped plots. Despite lower total nitrogen reserves after two growing seasons on the more intensively prepared plots (770 versus 1020 kg ha-1), ammonium and nitrate levels in the soil solution were twice that of the chopped plots; as a result, foliar-N levels of two-year-old planted seedlings were 0.93 versus 0.85%, respectively. Soil solution phosphorus levels averaged ten times higher and potassium averaged five times higher on the intensively prepared plots compared to the chopped plots. Total biomass of the competing vegetation two years after harvest was 1489 kg ha-1 on the intensively prepared plots compared to 3548 kg ha-1 on the chopped plots. At the end of the second season there was no difference in survival between the two treatments, but stem volume of trees on the intensively prepared plots was 2.8 times greater. This superior growth response elicited by intensive preparation was attributed to better moisture conditions, higher levels of available nutrients, and less competition. For. Sci. 34(1):77-87.
A Discrete State, Continuous Parameter Markov Process Approach to Timber Harvesting Systems Analysis
Authors: Hassler Curt C. , Disney Ralph L. , Singlair Steven A.
Published: April 2024

The introduction of simulation into timber harvesting systems analysis has spawned a proliferation of such models. As a result, the potential for applying stochastic process theory has been largely overlooked. This paper develops the theoretical aspects of a discrete state, continuous parameter Markov process model for application to timber harvesting systems analysis. Erlang and mixed Erlang probability distributions are introduced as models for time-based timber harvesting activities. These families of distributions are used because they offer flexibility in modeling the variety of distributions encountered in the field, yet maintain the integrity of the Markov assumptions. General formulation and solution of the Markov process model is discussed. An application of the theory to the analysis of timber harvesting system interaction is presented. The interaction between a grapple skidder and a mechanical slasher is formulated and solved as a discrete state, continuous parameter Markov process. The analytic solution showed that the system was severely unbalanced, with the skidder delayed 84.5% of the time, the slasher never idle, and both simultaneously performing productive work 15.5% of the time. For. Sci. 34(2):276-291.
A Framework for Stand Structure Projection of Uneven-Aged Loblolly-Shortleaf Pine Stands
Authors: Murphy Paul A. , Farrar Robert M.
Published: April 2024

A growth and yield model for uneven-aged loblolly-shortleaf pine (Pinus taeda L.-Pinus echinata Mill.) was developed. Stand-level equations for merchantable basal area, sawtimber basal area, quadratic mean diameter, and maximum tree diameter were derived first. Parameters for the doubly truncated Weibull distribution were obtained by the "parameter recovery" technique by using estimates of maximum diameter, quadratic mean diameter, and the sawtimber-merchantable basal area ratio. Compatibility for basal area estimates is thus maintained between the stand-level estimates and those produced from the Weibull distribution. Because inventory data were used to develop the model, potential users should be cautious in applying the model on an operational basis. For. Sci. 34(2):321-332.