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Recent Submissions
Mutu Kayu Gergajian Komersial di Toko Bangunan Kawasan Cibubur Berdasarkan Keragaan Fisik Kayunya
Christiawan, Nikolaus Adven; Nugroho, Naresworo; Larasatie, Pipiet; Karlinasarie, Lina (Mulawarman University, 2025-09-25)
Penggunaan kayu sebagai bahan material bangunan masih menjadi pilihan untuk berbagai keperluan termasuk untuk komponen bangunan. Kawasan Cibubur menjadi contoh daerah yang sangat pesat perkembangan wilayahnya karena dinggap menjaadi daerah penyangga beberapa kota besar dan industri. Penelitian ini bertujuan untuk menganalisis serta mengevaluasi kualitas kayu gergajian komersial yang dijual di pasaran melalui toko bangunan yang ada. Sampel penelitian berjumlah 1,050 sampel kayu dari berbagai bentuk dan ukuran sortimen berupa balok, papan, kaso, dan reng yang diperoleh dari 36 toko bangunan. Pengumpulan data dilakukan melalui penilaian visual dari 10 sampel untuk semua sortimen yang tersedia di toko bangunan. Penilaian jenis cacat berupa mata kayu, miring serat, dan cacat badan lain seperti retak dan pecah, serta cacat bentuk akibat proses pengeringan. Hasil penelitian menunjukkan cacat utama yang paling paling banyak dijumpai adalah cacat mata kayu. Sebagian besar sortimen yang dijual di kawasan Cibubur masih termasuk ke dalam mutu A. Penilaian terhadap strength ratio menunjukkan bahwa mayoritas sampel sortimen yang dijual di Kawasan Cibubur memiliki strength ratio yang tinggi masuk pada rentang 100-76%.
Northern Long-eared Bats in the Central Appalachians Following White-nose Syndrome: Failed Maternity Colonies?
Kalen, Nicholas J.; Muthersbaugh, Michael S.; Johnson, Joshua B.; Silvis, Alexander; Ford, W. Mark (2022)
Northern long-eared bat (Myotis septentrionalis) populations have experienced severe declines in eastern North America from white-nose syndrome (WNS), yet potential secondary effects on maternity roosting and recruitment remain largely unknown. We documented female dayroosting at two locations in the central Appalachians of Virginia, Back Creek Mountain (BCM) and Rapidan Camp (RC), during 2015 and 2016, approximately six years after the regional onset of WNS. We compared roost characteristics with available trees and roosts recorded prior to WNS at the Fernow Experimental Forest (FEF), West Virginia, in 2007 and 2008. Roosts at BCM were smaller than pre-WNS roosts but were otherwise similar in terms of stand condition and species use, though bats selected for red maple (Acer rubrum) at BCM rather than black locust (Robinia pseudoacacia) as at FEF. At RC, bats roosted almost exclusively in large eastern hemlock (Tsuga canadensis) snags (dbhx¯=50.13 cm, SD=23.1) with high solar exposure that had been killed by the hemlock woolly adelgid (Adelges tsugae). The two observed strategies, selection of smaller, midstory trees at BCM and of dominant, exposed roosts at RC, correspond with pre-WNS observations of female northern long-eared bat roost use at similar sites. However, our results suggest reliance on smaller roosts and canopy-dominant positions that better accommodate solitary individuals and small groups associated with smaller post-WNS colonies in terms of space and thermoregulatory benefits. Despite some observations of pregnant and lactating individuals, all three post-WNS colonies vacated roost networks in early June, and we observed no juveniles. Potential colony failure at BCM and RC is consistent with predicted secondary physiological effects from WNS-induced population collapses, suggesting, if recruitment failed, northern long-eared bats may already be functionally extirpated in portions of the central Appalachians.
Fast growth rate is associated with musculoskeletal biomechanical imbalance and dorsal cranial myopathy in broiler chickens
Lourenço-Silva, Marconi Italo; Norton, Anderson H. III; Jacobs, Leonie (Public Library of Science, 2025-09-01)
Dorsal cranial myopathy is a degenerative lesion that affects the anterior Latissimus dorsi muscle in broiler chickens, with an etiology that remains unknown. The objective was to investigate the influence of musculoskeletal biomechanical balance and gait on the prevalence of dorsal cranial myopathy in three broiler chicken strains with differing growth potential. Three-hundred and ninety-six broiler chickens from three genetic strains with differing growth potential (fast, intermediate, and slow, 132 birds/ strain) were housed in 18 pens with 22 birds/pen. Five birds/pen (n = 30 birds/genetic strain) were randomly wing- or leg-banded to assess gait and musculoskeletal biomechanical balance (by calculating body angulation) at 1, 2, 3, and 3.7 kg weight sampling points. Dorsal cranial myopathy was assessed one day after birds reached final body weight. Gait and musculoskeletal balance were both negatively impacted by body weight in fast- and slow-growing strains but not in the intermediate-growing strain. Dorsal cranial myopathy was more prevalent in fast-growing broilers compared to other strains, with no case observed in the slow-growing strain. Impaired gait negatively affected musculoskeletal biomechanical balance and increased the prevalence of dorsal cranial myopathy. Our results suggest that genetic strain, musculoskeletal biomechanical imbalance, poor gait, and high body weight are all associated with the prevalence of dorsal cranial myopathy in broiler chickens. We successfully simplified a non-invasive body posture methodology to quantify the musculoskeletal biomechanical balance in broiler chickens.
Telomere length as a biomarker for cumulative experience in broiler chickens
Campbell, Andrew M.; Anderson, Mallory G.; Haussmann, Mark F.; Rowell, Raquel; Jacobs, Leonie (Public Library of Science, 2025-06-25)
Cumulative experience can be defined as the sum of all positive and negative experiences during an animal’s lifetime. Telomere length shows promise as a biomarker of cumulative experience in humans and non-human animals but is not yet assessed for broiler chickens. Therefore, our objective was to determine telomere length changes due to positive and negative experiences in fast-growing broiler chickens. In three replicated experiments, male Ross 708 broilers were housed in a 2×2 factorial study investigating high environmental complexity as a positive environment (vs. low complexity; 6 pens/treatment) and high stocking density as a negative environment (vs. low density; 6 pens/treatment). Telomere length was quantified at day 48 of age via quantitative RT-PCR (qRT-PCR) from gonad and kidney samples (N=9 samples/ treatment/tissue/experiment). Prior to analysis, raw relative telomere length (rTL) values were z-transformed to allow comparison between experiments. Combined data from the three experiments were analyzed using mixed models with complexity, density, and their interactions as fixed factor and pen nested within experiment and qRT-PCR plate number as random factors. Over all three trials, birds housed in high complexity environments tended (P=0.0503) to have longer telomeres from kidney tissue than birds housed in low complexity environments. Stocking density did not impact combined kidney telomere length and gonadal telomere length was not impacted by environmental complexity or stocking density. Longer telomeres (statistical trend) in response to positive experience (environmental complexity) when compared to low-complexity indicate that high-complexity environments elicited positive cumulative experience in broiler chickens, although effect size was small. Telomere length has the potential to be a valuable tool in the assessment of cumulative experience in production settings, and future works should replicate these findings and expand upon this work by comparing telomere length with other more traditional animal welfare markers.
Mantle Transition Zone-Penetrating Upwellings Beneath the Eastern North American Margin and Beyond
Luo, Yantao; Long, Maureen D.; Rondenay, Stephane; King, Scott D.; Mazza, Sarah E.; Wolf, Jonathan (American Geophysical Union, 2025-04)
Low-velocity anomalies in the upper mantle beneath eastern North America, including the Northern Appalachian Anomaly (NAA), the Central Appalachian Anomaly (CAA), and the weaker Southern Coastal Anomaly (SCA), have been characterized by many continent-scale and regional seismic studies. Different models have been proposed to explain their existence beneath the passive margin of eastern North America, variously invoking the past passage of hot spot tracks, modern upwelling due to edge-driven convection, or other processes. Depending on the nature and origin of these anomalies, they may influence, and/or be influenced by, the mantle transition zone (MTZ) structure beneath them. Previous receiver function studies have identified an overall thinner MTZ beneath the eastern margin of the US than beneath the continental interior. In this study, we resolve the MTZ geometry beneath these low-velocity anomalies in unprecedented detail using the scattered wavefield migration technique. We find substantially thinned MTZ beneath the NAA and the CAA, and a moderately thinned MTZ beneath the SCA. In all cases, the thinning is achieved via a minor depression of the 410-km discontinuity and a major uplift of the 660-km discontinuity, which suggests the presence of a series of MTZ-penetrating deep upwellings beneath eastern North America. The upwellings beneath eastern North America and a similar style upwelling beneath Bermuda may initiate from ponded thermally buoyant materials below the MTZ fed by hot return flows from the descending Farallon slab in the deep mantle.