Stocking Rates and Carrying Capacity of Grazing Lands in Bale Mountain National Park and Adjacent Areas, Southeast Ethiopia

Knowledge of grazing land carrying capacity and grazing pressure in and around protected areas is very crucial to support decision making over sustainable grazing levels and developing grazing pressure reduction strategies. However, there was lack of studies conducted on livestock carrying capacity and grazing pressure in the connected and dynamic system over a wider landscape scale. Hence, this study was conducted to estimate the livestock stocking rates and carrying capacity of grazing lands in Bale Mountain National Park (BMNP) and adjacent districts grazing lands, southeast Ethiopia. Three categories of data: Field surveys, satellite imagery, and socioeconomic secondary data were used. Each of the three components of the data ware designed to synergistically provide scientific evidence to meet the study objectives. The result of the study shows the mean livestock stocking rate of grazing lands during wet and dry seasons in the park were 1.01 TLU/ha and 0.47 TLU/ha respectively. The mean livestock stocking rate of park adjacent district grazing lands during wet and dry season were 12.01 TLU/ha and 14.25 TLU/ha respectively. The mean carrying capacity of grazing land in the park during wet and dry seasons were 67.88 TLU Km2 (0.68TLU/ha) and 28.71 TLU Km2 (0.29 TLU/ha), respectively. The result shows the mean carrying capacity of park adjacent district grazing land during wet and dry seasons were 51.22 TLU Km2 (0.51TLU/ha) and 13.11 TLU Km2 (0.13 TLU/ha), respectively. Thus, the existing stocking rate is higher than the carrying capacity . Thus, it clearly signals the risk of overgrazing in the afroalpine habitat considering the herbivores wildlife in the study areas. In view of such a situation, measures have been suggested to reduce livestock population in order to protect the biodiversity and ecosystem services that BMNP and the buffer zone provides

The power of light – From dental materials processing to diagnostics and therapeutics

Harnessing the power of light and its photonic energy is a powerful tool in biomedical applications. Its use ranges from biomaterials processing and fabrication of polymers to diagnostics and therapeutics. Dental light curable materials have evolved over several decades and now offer very fast (≤ 10 s) and reliable polymerization through depth (4–6 mm thick). This has been achieved by developments on two fronts: (1) chemistries with more efficient light absorption characteristics (camphorquinone [CQ], ~30 L mol-1 cm1[ʎmax 470 nm]; monoacylphosphine oxides [MAPO], ~800 L mol-1 cm-1 [ʎmax 385 nm]; bisacylphosphine oxide [BAPO], ~1,000 L mol-1 cm-1 [ʎmax 385 nm]) as well mechanistically efficient and prolonged radical generation processes during and after light irradiation, and; (2) introducing light curing technologies (light emitting diodes [LEDs] and less common lasers) with higher powers (≤ 2 W), better spectral range using multiple diodes (short: 390–405 nm; intermediate: 410–450 nm; and long: 450–480 nm), and better spatial power distribution (i.e. homogenous irradiance). However, adequate cure of materials falls short for several reasons, including improper selection of materials and lights, limitations in the chemistry of the materials, and limitations in delivering light through depth. Photonic energy has further applications in dentistry which include transillumination for diagnostics, and therapeutic applications that include photodynamic therapy, photobiomodulation, and photodisinfection. Light interactions with materials and biological tis-sues are complex and it is important to understand the advantages and limitations of these interactions for successful treatment outcomes. This article highlights the advent of photonic technologies in dentistry, its applications, the advantages and limitations, and possible future developments

The dark art of light measurement: accurate radiometry for low-level light therapy

Lasers and light-emitting diodes are used for a range of biomedical applications with many studies reporting their beneficial effects. However, three main concerns exist regarding much of the low-level light therapy (LLLT) or photobiomodulation literature; (1) incomplete, inaccurate and unverified irradiation parameters, (2) miscalculation of ‘dose,’ and (3) the misuse of appropriate light property terminology. The aim of this systematic review was to assess where, and to what extent, these inadequacies exist and to provide an overview of ‘best practice’ in light measurement methods and importance of correct light measurement. A review of recent relevant literature was performed in PubMed using the terms LLLT and photobiomodulation (March 2014–March 2015) to investigate the contemporary information available in LLLT and photobiomodulation literature in terms of reporting light properties and irradiation parameters. A total of 74 articles formed the basis of this systematic review. Although most articles reported beneficial effects following LLLT, the majority contained no information in terms of how light was measured (73 %) and relied on manufacturer-stated values. For all papers reviewed, missing information for specific light parameters included wavelength (3 %), light source type (8 %), power (41 %), pulse frequency (52 %), beam area (40 %), irradiance (43 %), exposure time (16 %), radiant energy (74 %) and fluence (16 %). Frequent use of incorrect terminology was also observed within the reviewed literature. A poor understanding of photophysics is evident as a significant number of papers neglected to report or misreported important radiometric data. These errors affect repeatability and reliability of studies shared between scientists, manufacturers and clinicians and could degrade efficacy of patient treatments. Researchers need a physicist or appropriately skilled engineer on the team, and manuscript reviewers should reject papers that do not report beam measurement methods and all ten key parameters: wavelength, power, irradiation time, beam area (at the skin or culture surface; this is not necessarily the same size as the aperture), radiant energy, radiant exposure, pulse parameters, number of treatments, interval between treatments and anatomical location. Inclusion of these parameters will improve the information available to compare and contrast study outcomes and improve repeatability, reliability of studies

Implantable and transcutaneous photobiomodulation promote neuroregeneration and recovery of lost function after spinal cord injury

Spinal cord injury (SCI) is a cause of profound and irreversible damage, with no effective therapy to promote functional recovery. Photobiomodulation (PBM) may provide a viable therapeutic approach using red or near-infrared light to promote recovery after SCI by mitigating neuroinflammation and preventing neuronal apoptosis. Our current study aimed to optimize PBM dose regimens and develop and validate the efficacy of an invasive PBM delivery paradigm for SCI. Dose optimization studies were performed using a serum withdrawal model of injury in cultures of primary adult rat dorsal root ganglion neurons (DRGN). Implantable and transcutaneous PBM delivery protocols were developed and validated using cadaveric modeling. The efficacy of PBM in promoting recovery after SCI in vivo was studied in a dorsal column crush injury model of SCI in adult rats. Optimal neuroprotection in vitro was achieved between 4 and 22 mW/cm2. 11 mW/cm2 for 1 min per day (0.66 J/cm2) increased cell viability by 45% over 5 days (p <0.0001), increasing neurite outgrowth by 25% (p < 0.01). A method for invasive application of PBM was developed using a diffusion-tipped optogenetics fiber optic. Delivery methods for PBM were developed and validated for both invasive (iPBM) and noninvasive (transcutaneous) (tcPBM) application. iPBM and tcPBM (24 mW/cm2 at spinal cord, 1 min per day (1.44 J/cm2) up to 7 days) increased activation of regeneration-associated protein at 3 days after SCI, increasing GAP43+ axons in DRGN from 18.0% (control) to 41.4% ± 10.5 (iPBM) and 45.8% ± 3.4 (tcPBM) (p < 0.05). This corresponded to significant improvements at 6 weeks post-injury in functional locomotor and sensory function recovery (p < 0.01), axonal regeneration (p < 0.01), and reduced lesion size (p < 0.01). Our results demonstrated that PBM achieved a significant therapeutic benefit after SCI, either using iPBM or tcPBM application and can potentially be developed for clinical use in SCI patients

Photobiomodulation improves functional recovery after mild traumatic brain injury

Mild traumatic brain injury (mTBI) is a common consequence of head injury but there are no recognized interventions to promote recovery of the brain. We previously showed that photobiomodulation (PBM) significantly reduced the number of apoptotic cells in adult rat hippocampal organotypic slice cultures. In this study, we first optimized PBM delivery parameters for use in mTBI, conducting cadaveric studies to calibrate 660 and 810 nm lasers for transcutaneous delivery of PBM to the cortical surface. We then used an in vivo weight drop mTBI model in adult rats and delivered daily optimized doses of 660, 810 nm, or combined 660/810 nm PBM. Functional recovery was assessed using novel object recognition (NOR) and beam balance tests, whilst histology and immunohistochemistry were used to assess the mTBI neuropathology. We found that PBM at 810, 660 nm, or 810/660 nm all significantly improved both NOR and beam balance performance, with 810 nm PBM having the greatest effects. Histology demonstrated no overt structural damage in the brain after mTBI, however, immunohistochemistry using brain sections showed significantly reduced activation of both CD11b+ microglia and glial fibrillary acidic protein (GFAP)+ astrocytes at 3 days post-injury. Significantly reduced cortical localization of the apoptosis marker, cleaved caspase-3, and modest reductions in extracellular matrix deposition after PBM treatment, limited to choroid plexus and periventricular areas were also observed. Our results demonstrate that 810 nm PBM optimally improved functional outcomes after mTBI, reduced markers associated with apoptosis and astrocyte/microglial activation, and thus may be useful as a potential regenerative therapy

Differential responses of myoblasts and myotubes to photobiomodulation are associated with mitochondrial number

Objective Photobiomodulation (PBM) is the application of light to promote tissue healing. Current indications suggest PBM induces its beneficial effects in vivo through upregulation of mitochondrial activity. However, how mitochondrial content influences such PBM responses have yet to be evaluated. Hence, the current study assessed the biological response of cells to PBM with varying mitochondrial contents. Methods DNA was isolated from myoblasts and myotubes (differentiated myoblasts), and mitochondrial DNA (mtDNA) was amplified and quantified using a microplate assay. Cells were seeded in 96‐wellplates, incubated overnight and subsequently irradiated using a light‐emitting diode array (400, 450, 525, 660, 740, 810, 830 and white light, 24 mW/cm2, 30‐240 seconds, 0.72‐5.76J/cm2). The effects of PBM on markers of mitochondrial activity including reactive‐oxygen‐species and real‐time mitochondrial respiration (Seahorse XFe96) assays were assessed 8 hours post‐irradiation. Datasets were analysed using general linear model followed by one‐way analysis of variance (and post hoc‐Tukey tests); P = 0.05). Results Myotubes exhibited mtDNA levels 86% greater than myoblasts (P < 0.001). Irradiation of myotubes at 400, 450 or 810 nm induced 53%, 29% and 47% increases (relative to non‐irradiated control) in maximal respiratory rates, respectively (P < 0.001). Conversely, irradiation of myoblasts at 400 or 450 nm had no significant effect on maximal respiratory rates. Conclusion This study suggests that mitochondrial content may influence cellular responses to PBM and as such explain the variability of PBM responses seen in the literature

Barrier Tissue Macrophages: Functional Adaptation to Environmental Challenges

Macrophages are found throughout the body, where they have crucial roles in tissue development, homeostasis and remodeling, as well as being sentinels of the innate immune system that can contribute to protective immunity and inflammation. Barrier tissues, such as the intestine, lung, skin and liver, are exposed constantly to the outside world, which places special demands on resident cell populations such as macrophages. Here we review the mounting evidence that although macrophages in different barrier tissues may be derived from distinct progenitors, their highly specific properties are shaped by the local environment, which allows them to adapt precisely to the needs of their anatomical niche. We discuss the properties of macrophages in steady-state barrier tissues, outline the factors that shape their differentiation and behavior and describe how macrophages change during protective immunity and inflammation