Bone mineral density in adults with Down syndrome: a cross-sectional study in a Brazilian sample.

BACKGROUND: We aim to investigate the relationship between bone mass in a sample of Brazilian individuals with DS and handgrip strength, body mass index (BMI) and physical exercise. METHODS: Dual-energy X-ray emission densitometry analysis of bone mass in 26 individuals with DS (8 men and 18 women with a mean age of 30.7 ± 10.3 years) was conducted. Additionally, weight and height were measured to determine BMI, palmar grip strength was measured using a Jammar dynamometer®, and physical activity was classified using the International Physical Activity Questionnaire (IPAQ). RESULTS: In this sample, 2/15 (13.3%) individuals with age between 18 to 29 years had low BMD in the spine; 2/8 (25%) of those with age between 30 and 39 years also had low BMD in the spine and 2/3 (66.6%) with age ≥40 had low BMD in the femur. There were significant correlations between palmar grip strength and Z femoral neck score in women (P = 0.02) and between BMI and Z femoral neck score in men (P = 0.04). All other correlations lacked statistical significance (P > 0.05). CONCLUSIONS: Brazilian patients with DS showed a high prevalence of low bone mass. Traditional factors such as muscle strength, BMI and physical activity appear to have little effect on bone mineral density in this population.

Assessing the potential of poplar short rotation plantations to contribute to a low-carbon bioeconomy under water-limited conditions.

Poplar short rotation coppice (SRC) systems are important for biomass production and for short-to medium-term carbon (C) sequestration, contributing to a low-carbon bioeconomy and thus helping to mitigate global warming. The productivity and profitability of these plantations are, however, challenged under restrictive irrigation associated with climate change. This study compares the above- and below-ground C sequestration potential and economic viability of a 12-year plantation cycle (4 rotations of 3 years each) under Mediterranean conditions with optimum irrigation (T1) and 50% irrigation reduction (T2), analysing other promising biomass uses in the form of bioproducts. A total of 138 trees of the highly productive hybrid ('AF2') in a SRC-trial were sampled monthly (first rotation). Additionally, data from an extensive poplar plantation network (30 sites) was used to complete data for the plantation cycle. The average C content for above- and below-ground biomass was 17.04 Mg C ha-1 yr-1 (T1), falling by 24% in T2. The net present value (NPV) in T1 (6461 € ha-1) was 52% lower under T2 conditions. Extra payments for C sequestration increased the NPV to 8023 for T1 and 4331 € ha-1 for T2. Roots represent an important C storage in the soil, accumulating 29.9 Mg C ha-1 (T1) and 22.8 Mg C ha-1 (T2) by the end of the cycle in our study. The mitigation potential is strongly fortified when the share of bioproducts in biomass end-use increases. Assuming a distribution of 50% bioenergy and 50% bioproducts, emission were reduced between -114 Mg CO2eq ha-1 (T1) and -88 Mg CO2eq ha-1 (T2) compared to BAU until end of the century. This scenario plays a crucial sink-effect role by storing C contained in biomass, which is not immediately released into the atmosphere.

Effects of aerobic exercise on molecular aspects of asthma: involvement of SOCS-JAK-STAT.

BACKGROUND: Aerobic training (AT) decreases airway inflammation in asthma, but the underlying cellular and molecular mechanisms are not completely understood. Thus, this study evaluated the participation of SOCS-JAK-STAT signaling in the effects of AT on airway inflammation, remodeling and hyperresponsiveness in a model of allergic airway inflammation. METHODS: C57Bl/6 mice were divided into Control (Co), Exercise (Ex), HDM (HDM), and HDM+Exercise (HDM+ Ex). Dermatophagoides pteronyssinus (100ug/mouse) were administered oro-tracheally on days 0, 7, 14, 21, 28, 35, 42 and 49. AT was performed in a treadmill during 4 weeks in moderate intensity, from day 24 until day 52. RESULTS: AT inhibited HDM-induced total cells (p<0.001), eosinophils (p<0.01), neutrophils (p<0.01) and lymphocytes (p<0.01) in BAL, and eosinophils (p<0.01), neutrophils (p<0.01) and lymphocytes (p<0.01) in peribronchial space. AT also reduced BAL levels of IL-4 (p<0.001), IL-5 (p<0.001), IL-13 (p<0.001), CXCL1 (p<0.01), IL-17 (p<0.01), IL-23 (p<0.05), IL-33 (p<0.05), while increased IL- 10 (p<0.05). Airway collagen fibers (p<0.01), elastic fibers p<0.01) and mucin (p<0.01) were also reduced by AT. AT also inhibited HDM-induced airway hyperresponsiveness (AHR) to methacholine 6,25mg/ml (p<0.01), 12,5mg/mL (p<0.01), 25mg/mL (p<0.01) and 50mg/mL (p<0.01). Mechanistically, AT reduced the expression of STAT6 (p<0.05), STAT3 (p<0.001), STAT5 (p<0.01) and JAK2 (p<0.001), similarly by peribronchial leukocytes and by airway epithelial cells. SOCS1 expression (p<0.001) was upregulated in leukocytes and in epithelial cells, SOCS2 (p<0.01) was upregulated in leukocytes and SOCS3 down-regulated in leukocytes (p<0.05) and in epithelial cells (p<0.001). CONCLUSIONS: AT reduces asthma phenotype involving SOCSJAK- STAT signaling.

The spin-forbidden vacuum-ultraviolet absorption spectrum of 14N15N.

Photoabsorption spectra of 14N15N were recorded at high resolution with a vacuum-ultraviolet Fourier-transform spectrometer fed by synchrotron radiation in the range of 81-100 nm. The combination of high column density (3 × 1017 cm-2) and low temperature (98 K) allowed for the recording of weak spin-forbidden absorption bands' exciting levels of triplet character. The triplet states borrow intensity from 1Πu states of Rydberg and valence character while causing their predissociation. New predissociation linewidths and molecular constants are obtained for the states C3Πu(v = 7, 8, 14, 15, 16, 21), G3Πu(v = 0, 1, 4), and F3Πu(v = 0). The positions and widths of these levels are shown to be well-predicted by a coupled-Schrödinger equation model with empirical parameters based on experimental data on 14N2 and 15N2 triplet levels.

Quantifying the photoionization cross section of the hydroxyl radical.

The hydroxyl free radical, OH, is one of the most important radicals in atmospheric and interstellar chemistry, and its cation plays a role in the reactions leading to H2O formation. Knowledge of the photoionization efficiency of the OH radical is crucial to properly model the water photochemical cycle of atmospheres and astrophysical objects. Using a gas-phase radical source based on a single H-abstraction reaction combined with a photoelectron/photoion imaging coincidence spectrometer coupled with synchrotron radiation, we recorded the OH+ photoion yield over the 12.6-15 eV energy range, and we set it to an absolute cross section scale using an absolute point measurement performed at 13.8 eV: σOH ion=9.0±2.7 Mb. The resulting cross section values differ by approximately a factor 2 from the recent measurement of Dodson et al. [J. Chem. Phys. 148, 184302 (2018)] performed with a different radical source, which is somewhat greater than the combined uncertainties of the measurements. This finding underlines the need for further investigations of this cross section.

Fourier-transform-spectroscopic photoabsorption cross sections and oscillator strengths for the S2 BΣu-3-XΣg-3 system.

Photoabsorption cross sections and oscillator strengths for the strong, predissociating vibrational bands, v ≥ 11, in the S2 BΣu-3-XΣg-3(v,0) system are reported. Absorption measurements were undertaken on S2 vapor produced by a radio-frequency discharge through H2S seeded in helium, and also in a two-temperature sulfur furnace, at temperatures of 370 K and 823 K, respectively. S2 column densities were determined in each source by combining experimental line strengths in low-v non-predissociating B - X bands (v < 7) with calculated line f-values based on measured radiative lifetimes and calculated branching ratios. The broad-band capabilities of two vacuum-ultraviolet Fourier-transform spectrometers, used with instrumental resolutions of 0.22 cm-1 and 0.12 cm-1, respectively, allowed for simultaneous recordings of both non-predissociating and predissociating bands, thus placing the predissociating-band cross sections on a common absolute scale. Uncertainties in the final cross section datasets are estimated to be 15% for the 370-K vapor and 10% for the 823-K vapor. The experimental cross sections are used to inform a detailed predissociation model of the B(v) levels in Paper II [Lewis et al., J. Chem. Phys. 148, 244303 (2018)]. For astrophysical and other applications, this model can be adjusted simply to provide isotopologue-specific cross sections for a range of relevant temperatures.

Iliac Seal Zone Dynamics and Clinical Consequences After Endovascular Aneurysm Repair.

OBJECTIVE: To evaluate the dynamics of the iliac attachment zone after EVAR, and the association with clinical events. METHODS: A tertiary institution's prospective EVAR database was searched to identify common iliac arteries at risk. Internally validated measurements were made, using centre lumen line reconstructions. Iliac dilatation and endograft limb retraction were the main endpoints. Associations between dilatation, retraction, oversizing, and distal seal length were investigated. Association with clinical events (sealing or occlusion) was also explored. RESULTS: Of 452 primary EVAR patients treated from 2004 to 2012, 341 were included (mean age 72 years, 12% female, 597 common iliac arteries). Median follow-up was 4.7 years. At 30 days, the mean iliac diameter increased from 14 mm to 15 mm (p < .001). Over follow-up, it increased to 18 mm (p < .001). Iliac dilatation ≥20% occurred in 295 cases (49.4%) and exceeded the implanted endograft diameter in 170 (28.7%). Limb retraction ≥5 mm was identified in 54 patients (9.1%) and was associated with iliac seal complications (p < 0.001). Iliac endograft extension diameter ≥24 mm (OR 3.3, 95% CI 1.7-6.4) and iliac artery dilatation beyond the endograft (OR 2.1, 95% CI 1.2-3.8) were independent risk factors. Overall, there were 34 (5.7%) iliac seal complications. Retraction of the iliac endograft (OR 1.17 per mm, 95% CI 1.10-1.24) and baseline AAA diameter (1.04 per mm, 95% CI 1.01-1.07) were independent risk factors for seal related complications. Greater initial post-operative iliac seal length was protective (OR 0.94 per mm, 95% CI 0.90-0.97). CONCLUSIONS: Iliac dilatation and endograft retraction are common findings during follow-up, potentially leading to adverse clinical events. Optimisation of the iliac seal zone providing a long distal seal length and added attention to patients with large aneurysms or receiving ≥24 mm diameter iliac extensions are recommended. Also, long-term surveillance including CTA is advised to reveal and correct loss of seal at the iliac attachments before adverse clinical events occur.

The role of epigenetic modifiers in extended cultures of functional hepatocyte-like cells derived from human neonatal mesenchymal stem cells.

The development of predictive in vitro stem cell-derived hepatic models for toxicological drug screening is an increasingly important topic. Herein, umbilical cord tissue-derived mesenchymal stem cells (hnMSCs) underwent hepatic differentiation using an optimized three-step core protocol of 24 days that mimicked liver embryogenesis with further exposure to epigenetic markers, namely the histone deacetylase inhibitor trichostatin A (TSA), the cytidine analogue 5-azacytidine (5-AZA) and dimethyl sulfoxide (DMSO). FGF-2 and FGF-4 were also tested to improve endoderm commitment and foregut induction during Step 1 of the differentiation protocol, being HHEX expression increased with FGF-2 (4 ng/mL). DMSO (1%, v/v) when added at day 10 enhanced cell morphology, glycogen storage ability, enzymatic activity and induction capacity. Moreover, the stability of the hepatic phenotype under the optimized differentiation conditions was examined up to day 34. Our findings showed that hepatocyte-like cells (HLCs) acquired the ability to metabolize glucose, produce albumin and detoxify ammonia. Global transcriptional analysis of the HLCs showed a partial hepatic differentiation degree. Global analysis of gene expression in the different cells revealed shared expression of gene groups between HLCs and human primary hepatocytes (hpHeps) that were not observed between HepG2 and hpHeps. In addition, bioinformatics analysis of gene expression data placed HLCs between the HepG2 cell line and hpHeps and distant from hnMSCs. The enhanced hepatic differentiation observed was supported by the presence of the hepatic drug transporters OATP-C and MRP-2 and gene expression of the hepatic markers CK18, TAT, AFP, ALB, HNF4A and CEBPA; and by their ability to display stable UGT-, EROD-, ECOD-, CYP1A1-, CYP2C9- and CYP3A4-dependent activities at levels either comparable with or even higher than those observed in primary hepatocytes and HepG2 cells. Overall, an improvement of the hepatocyte-like phenotype was achieved for an extended culture time suggesting a role of the epigenetic modifiers in hepatic differentiation and maturation and presenting hnMSC-HLCs as an advantageous alternative for drug discovery and in vitro toxicology testing.

Phylogenetic analysis of Monascus and new species from honey, pollen and nests of stingless bees.

The genus Monascus was described by van Tieghem (1884) to accommodate M. ruber and M. mucoroides, two species with non-ostiolate ascomata. Species delimitation in the genus is still mainly based on phenotypic characters, and taxonomic studies that include sequence data are limited. The genus is of economic importance. Species are used in fermented Asian foods as food colourants (e.g. 'red rice' (ang-kak, angka)) and found as spoilage organisms, and recently Monascus was found to be essential in the lifecycle of stingless bees. In this study, a polyphasic approach was applied combining morphological characters, ITS, LSU, ß-tubulin, calmodulin and RNA polymerase II second largest subunit sequences and extrolite data, to delimit species and to study phylogenetic relationships in Monascus. Furthermore, 30 Monascus isolates from honey, pollen and nests of stingless bees in Brazil were included. Based on this polyphasic approach, the genus Monascus is resolved in nine species, including three new species associated with stingless bees (M. flavipigmentosus sp. nov., M. mellicola sp. nov., M. recifensis sp. nov., M. argentinensis, M. floridanus, M. lunisporas, M. pallens, M. purpureus, M. ruber), and split in two new sections (section Floridani sect. nov., section Rubri sect. nov.). Phylogenetic analysis showed that the xerophile Monascus eremophilus does not belong in Monascus and monophyly in Monascus is restored with the transfer of M. eremophilus to Penicillium (P. eremophilum comb. nov.). A list of accepted and excluded Monascus and Basipetospora species is given, together with information on (ex-)types cultures and barcode sequence data.

Population genetic structure of three species in the genus Astrocaryum G. Mey. (Arecaceae).

We assessed the level and distribution of genetic diversity in three species of the economically important palm genus Astrocaryum located in Pará State, in northern Brazil. Samples were collected in three municipalities for Astrocaryum aculeatum: Belterra, Santarém, and Terra Santa; and in two municipalities for both A. murumuru: Belém and Santo Antônio do Tauá and A. paramaca: Belém and Ananindeua. Eight microsatellite loci amplified well and were used for genetic analysis. The mean number of alleles per locus for A. aculeatum, A. murumuru, and A. paramaca were 2.33, 2.38, and 2.06, respectively. Genetic diversity was similar for the three species, ranging from HE = 0.222 in A. aculeatum to HE = 0.254 in A. murumuru. Both FST and AMOVA showed that most of the genetic variation was found within populations for all three species, but high genetic differentiation among populations was found for A. aculeatum. Three loci were not in Hardy-Weinberg equilibrium, with populations of A. paramaca showing a tendency for the excess of heterozygotes (FIS = -0.144). Gene flow was high for populations of A. paramaca (Nm = 19.35). Our results suggest that the genetic diversity within populations followed the genetic differentiation among populations due to high gene flow among the population. Greater geographic distances among the three collection sites for A. aculeatum likely hampered gene flow for this species.

The antimicrobial peptide aureocin A53 as an alternative agent for biopreservation of dairy products.

AIMS: The aim of this study was to investigate the potential of aureocin A53, a staphylococcal antimicrobial peptide, for improving food safety. METHODS AND RESULTS: The antimicrobial activity of aureocin A53 against strains of Listeria monocytogenes isolated from food was tested and the bacteriocin proved to be bactericidal and bacteriolytic against the listerial strains. Aureocin A53 was neither toxic to eukaryotic cell lines nor haemolytic against sheep erythrocytes. It also exhibited a remarkable stability during storage at different temperatures and sensitivity to both simulated gastric juice and bile salts. When the antibacterial activity of aureocin A53 (256 AU ml(-1) ) was tested in skimmed milk artificially inoculated with a L. monocytogenes strain (1·0 × 10(4)  CFU ml(-1) ) isolated from food, during storage at 4°C, the bacteriocin reduced the viable counts by 7·7-log10 units up to 7 days of incubation, when compared with the controls not treated with the bacteriocin. CONCLUSIONS: Aureocin A53 exhibited several features considered important for biopreservation and remained fully active in a food matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: Taken together, the results confirmed that aureocin A53 has potential to be used as a food preservative, representing an alternative to the use of nisin in biopreservation of dairy products.

Optimal first trimester preeclampsia prediction: a comparison of multimarker algorithm, risk profiles and their sequential application.

OBJECTIVE: To compare performance of multimarker algorithm, risk profiles and their sequential application in prediction of preeclampsia and determining potential intervention targets. STUDY DESIGN: Maternal characteristics, ultrasound variables and serum biomarkers were collected prospectively at first trimester. Univariate analysis identified preeclampsia associated variables followed by logistic regression analysis to determine the prediction rule. Combined characteristics of the cardiovascular, metabolic and the personal risk factors were compared to the multimarker algorithm and the sequential application of both methods. RESULTS: Out of 2433 women, 108 developed preeclampsia (4.4%). Probability scores considering nulliparity, prior preeclampsia, body mass index, diastolic blood pressure and placental growth factor had an area under the receiver operating characteristic curve 0.784 (95% CI = 0.721-0.847). While the multimarker algorithm had the lowest false negative rate, sequential application of cardiovascular and metabolic risk profiles in screen positives reduced false positives by 26% and identified blood pressure and metabolic risk in 49/54 (91%) women with subsequent preeclampsia as treatable risk factors. CONCLUSION: Sequential application of a multimarker algorithm followed by determination of treatable risk factors in screen positive women is the optimal approach for first trimester preeclampsia prediction and identification of women that may benefit from targeted metabolic or cardiovascular treatment. © 2015 John Wiley & Sons, Ltd.

Comparative proteomic analysis of ductal and lobular invasive breast carcinoma.

Breast cancer is the second most common cancer worldwide and the first among women. Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the two major histological subtypes, and the clinical and molecular differences between them justify the search for new markers to distinguish them. As proteomic analysis allows for a powerful and analytical approach to identify potential biomarkers, we performed a comparative analysis of IDC and ILC samples by using two-dimensional electrophoresis and mass spectrometry. Twenty-three spots were identified corresponding to 10 proteins differentially expressed between the two subtypes. ACTB, ACTG, TPM3, TBA1A, TBA1B, VIME, TPIS, PDIA3, PDIA6, and VTDB were upregulated in ductal carcinoma compared to in lobular carcinoma samples. Overall, these 10 proteins have a key role in oncogenesis. Their specific functions and relevance in cancer initiation and progression are further discussed in this study. The identified peptides represent promising biomarkers for the differentiation of ductal and lobular breast cancer subtypes, and for future interventions based on tailored therapy.

Who runs the fastest? Anthropometric and physiological correlates of 20 m sprint performance in male soccer players.

The aim of the present study was to examine the relationship of 20 m sprint performance with anthropometrical and physiological parameters in male soccer players. A hundred and 81 soccer players from the region of Athens (age 23.4 ± 5.0 yrs, body mass 73.4 ± 7.7 kg, height 180.0 ± 5.9 cm, body fat (BF) 14.4 ± 3.6%), classified into quartiles according to 20 m sprint time (group A, 2.84-3.03 s; group B, 3.04-3.09 s; group C, 3.10-3.18 s; group D, 3.19-3.61 s), participated. Soccer players in group A were younger and had better performance in vertical jumps and in the Wingate anaerobic test (WAnT, p < 0.05). Sprint time correlated to age (r = 0.27), body mass (r = 0.23), body height (r = 0.20), BF (r = 0.23), vertical jumps (-0.58 ≤ r ≤ -0.50) and the WAnT (-0.45 ≤ r ≤ -0.30, p < 0.05). In summary, the magnitude of correlations of sprint time with measures of lower limbs muscle strength and power (WAnT and jumps) was larger than with anthropometric measures (body mass and BF).

Reduced Incidence of Cytomegalovirus Infection in Kidney Transplant Recipients Receiving Everolimus and Reduced Tacrolimus Doses.

This study compared the incidence of CMV infection/disease in de novo kidney transplant recipients receiving everolimus or mycophenolate and no CMV pharmacological prophylaxis. We randomized 288 patients to receive a single 3 mg/kg dose of antithymocyte globulin, tacrolimus, everolimus, and prednisone (r-ATG/EVR, n = 85); basiliximab, tacrolimus, everolimus, and prednisone (BAS/EVR, n = 102); or basiliximab, tacrolimus, mycophenolate, and prednisone (BAS/MPS, n = 101). The primary end-point was the incidence of first CMV infection/disease in the intention-to-treat population at 12 months. Patients treated with r-ATG/EVR showed a 90% proportional reduction (4.7% vs. 37.6%, HR 0.10, 95% CI 0.037-0.29; p < 0.001), while those treated with BAS/EVR showed a 75% proportional reduction (10.8% vs. 37.6%, HR 0.25, 95% CI 0.13-0.48; p < 0.001) in the incidence of CMV infection/disease compared to BAS/MPS. There were no differences in the incidence of acute rejection (9.4 vs. 18.6 vs. 15.8%, p = 0.403), wound-healing complications, delayed graft function, and proteinuria. Mean estimated glomerular filtration rate was lower in BAS/EVR (65.7 ± 21.8 vs. 60.6 ± 20.9 vs. 69.5 ± 21.5 ml/min, p = 0.021). In de novo kidney transplant recipients receiving no pharmacological CMV prophylaxis, reduced-dose tacrolimus and everolimus was associated with a significant reduction in the incidence of CMV infection/disease compared to standard tacrolimus dose and mycophenolate (ClinicalTrials.gov NCT01354301).

Mid-Term Results of EVAR in Severe Proximal Aneurysm Neck Angulation.

OBJECTIVE: To determine if mid-term outcome following endovascular aneurysm repair (EVAR) with the Endurant Stent Graft (Medtronic, Santa Rosa, CA, USA) is influenced by severe proximal neck angulation. METHODS: A retrospective case-control study was performed using data from a prospective multicenter database. All measurements were obtained using dedicated reconstruction software and center-lumen line reconstruction. Patients with neck length >15 mm, infrarenal angle ß > 75°, and/or suprarenal angle α > 60°, or neck length >10 mm with ß > 60°, and/or α > 45° were compared with a matched control group. Primary endpoint was primary clinical success. Secondary endpoints were freedom from rupture, type 1A endoleak, stent fractures, freedom from neck-related reinterventions, and aneurysm-related adverse events. Morphological neck variation over time was also assessed. RESULTS: Forty-five patients were included in the study group and were compared with a matched control group with 65 patients. Median follow-up time was 49.5 months (range 30.5-58.4). The 4-year primary clinical success estimates were 83% and 80% for the angulated and nonangulated groups (p = .42). Proximal neck angulation did not affect primary clinical success in a multivariate model (hazard ratio 1.56, 95% confidence interval 0.55-4.41).Groups did not differ significantly in regard to freedom from rupture (p =.79), freedom from type 1A endoleak (p = .79), freedom from neck-related adverse events (p = .68), and neck-related reinterventions (p = .68). Neck angle reduction was more pronounced in patients with severe proximal neck angulation (mean deltaα -15.6°, mean deltaß -30.6°) than in the control group (mean deltaα -0.39°, mean deltaß -5.9°) (p < .001). CONCLUSION: Mid-term outcomes following EVAR with the Endurant Stent Graft were not influenced by severe proximal neck angulation in our population. Despite the conformability of the device, moderate aortic neck remodeling was identified in the group of patients with angulated neck anatomy on the first computed tomography scan after implantation with no important further remodeling afterwards. No device integrity failures were encountered.

A Near-Threshold Shape Resonance in the Valence-Shell Photoabsorption of Linear Alkynes.

The room-temperature photoabsorption spectra of a number of linear alkynes with internal triple bonds (e.g., 2-butyne, 2-pentyne, and 2- and 3-hexyne) show similar resonances just above the lowest ionization threshold of the neutral molecules. These features result in a substantial enhancement of the photoabsorption cross sections relative to the cross sections of alkynes with terminal triple bonds (e.g., propyne, 1-butyne, 1-pentyne, ...). Based on earlier work on 2-butyne [ Xu et al., J. Chem. Phys. 2012, 136, 154303 ], these features are assigned to excitation from the neutral highest occupied molecular orbital (HOMO) to a shape resonance with g (l = 4) character and approximate π symmetry. This generic behavior results from the similarity of the HOMOs in all internal alkynes, as well as the similarity of the corresponding gπ virtual orbital in the continuum. Theoretical calculations of the absorption spectrum above the ionization threshold for the 2- and 3-alkynes show the presence of a shape resonance when the coupling between the two degenerate or nearly degenerate π channels is included, with a dominant contribution from l = 4. These calculations thus confirm the qualitative arguments for the importance of the l = 4 continuum near threshold for internal alkynes, which should also apply to other linear internal alkynes and alkynyl radicals. The 1-alkynes do not have such high partial waves present in the shape resonance. The lower l partial waves in these systems are consistent with the broader features observed in the corresponding spectra.