Increasing Fiber Length Research Articles

Numerical simulation of four-wave mixing efficiency and its induced relative intensity noise

Four-wave mixing, as well as its induced intensity noise, is harmful to wavelength division multiplexing systems. The efficiency and the relative intensity noise of four-wave mixing are numerically simulated for the two-wave and the three-wave fiber transmissions. It is found that the efficiency decreases with the increase of both the frequency spacing and the fiber length, which can be explained using the quasi-phase-matching condition. Furthermore, the relative intensity noise decreases with the increase of frequency spacing, while it increases with the increase of fiber length, which is due to the considerable power loss of the pump light. This investigation presents a good reference for the practical application of wavelength division multiplexing systems.

Overexpression of a Potato Sucrose Synthase Gene in Cotton Accelerates Leaf Expansion, Reduces Seed Abortion, and Enhances Fiber Production

Sucrose synthase (Sus) is a key enzyme in the breakdown of sucrose and is considered a biochemical marker for sink strength, especially in crop species, based on mutational and gene suppression studies. It remains elusive, however, whether, or to what extent, increase in Sus activity may enhance sink development. We aimed to address this question by expressing a potato Sus gene in cotton where Sus expression has been previously shown to be critical for normal seed and fiber development. Segregation analyses at T1 generation followed by studies in homozygous progeny lines revealed that increased Sus activity in cotton (1) enhanced leaf expansion with the effect evident from young leaves emerging from shoot apex; (2) improved early seed development, which reduced seed abortion, hence enhanced seed set, and (3) promoted fiber elongation. In young leaves of Sus overexpressing lines, fructose concentrations were significantly increased whereas, in elongating fibers, both fructose and glucose levels were increased. Since hexoses contribute little to osmolality in leaves, in contrast to developing fibers, it is concluded that high Sus activity promotes leaf development independently of osmotic regulation, probably through sugar signaling. The analyses also showed that doubling the Sus activity in 0-d cotton seeds increased their fresh weight by about 30%. However, further increase in Sus activity did not lead to any further increase in seed weight, indicating an upper limit for the Sus overexpression effect. Finally, based on the observed additive effect on fiber yield from increased fiber length and seed number, a new strategy is proposed to increase cotton fiber yield by improving seed development as a whole, rather than solely focusing on manipulating fiber growth.

Study of Hybridized Kenaf/Palf-Reinforced Hdpe Composites by Dynamic Mechanical Analysis

This article presents an experimental study on the dynamic mechanical property of hybridized Kenaf/PALF-reinforced HDPE composites. Variation in storage modulus (E′), loss modulus (E″) and damping parameter (tan δ) with fiber loading and variation in fiber length were investigated. The concept of hybridization was also discussed as it affects the dynamic properties. Initial storage modulus (E′) of all hybrids at different fibre ratios have been enormously improved compared to pure HDPE, and dependence of modulus on cellulose content of natural fibres was very clear. A lower percentage of PALF is required for hybridization with kenaf bast fibre to achieve a positive hybridization effect. Adequate hybridization could impart higher impact strength to the composite. The dynamic modulus curve showed an increase in the E′ value with increase in operating temperature up to about 130°C and is at a maximum at higher fibre loading. At lower temperatures, 60% of fibre loading had reduced the loss modulus peak of the pure HDPE. At temperature range of 30 to 65°C, incorporation of the fibres helped reduce the E″ peak of the matrix. Increasing the fibre content of the hybrids raised the damping peak with temperature. In addition, there is an increase in storage modulus with increased fibre length at room temperature up to about 65°C. Above this temperature, variation in fibre length became irrelevant up to the less viscous point of the matrix. A marginal difference in loss modulus with variation in fibre length was observed, no difference could be seen in the case of loss tangent (tan delta) in regard to variation in fibre length.

Performance analysis of dense wavelength division multiplexing secure communications with multiple chaotic optical channels

The performance of dense wavelength division multiplexing secure communications with multiple chaotic optical channels is numerically analyzed in this paper. Taking the multiplexing of three chaotic optical channels as an example, we investigate the effects of second-order dispersion coefficient and nonlinear coefficient of fiber, channel spacing, message amplitude and bit rates on chaotic synchronization and multiplexing communications. Chaotic synchronization quality and Q-factor of the recovered message decrease with the increasing fiber length. A 1.25 Gbits/s non-return-to-zero (NRZ) sequence can be securely transmitted up to 60 km under the influence of the other two chaotic optical channels. Compared with the fiber dispersion, the cross-phase modulation is the primary factor which deteriorates the quality of communications. The results also show that the quality of communications is unlimited to the channel spacing as long as chaotic synchronization can be maintained. In addition, the effect of the amplitude of encrypted message on Q-factor and the confidentiality is demonstrated.

Overexpression of GhSusA1 increases plant biomass and improves cotton fiber yield and quality

Cotton (Gossypium spp.) is an important economic crop and the largest source of textile fiber in the world. However, to date, only a few genes have been identified that exhibit critical roles in fiber development, and few has shown positive effects on fiber yield and quality in transgenic cotton. Here, we report the characterization of a novel sucrose synthase (SusA1) gene from a superior quality fiber germplasm line 7235 in Gossypium hirsutum. By association analysis, GhSusA1 was highly correlated with fiber qualities in (7235× TM-1) recombinant inbred lines based on polymorphism of GhSusA1 between 7235 and TM-1. Subsequently, based on an interspecific population of 141 BC₁ individuals generated from the cross between TM-1 and Gossypium barbadense line, Hai7124, we further mapped GhSusA1 genes on homeologous chromosomes A8 (chro.8) and D8 (chro.24). Suppression of GhSusA1 in transgenic cotton reduced fiber quality and decreased the boll size and seed weight. Importantly, overexpression of this gene increased fiber length and strength, with the latter indicated by the enhanced thickening of cell wall during secondary wall formation stage. Moreover, increasing GhSusA1 transcript abundance in vegetative tissues led to elevated seedling biomass. Together, these findings identified GhSusA1 as a key regulator of sink strength in cotton, which is tightly associated with productivity, and hence a promising candidate gene that can be developed to increase cotton fiber yield and quality.

Testing on Energy Absorption of Banana Fiber Polyester Composite

Natural fibers are now becoming a subject of interest to replace synthetic fiber as reinforcement materials where the development of natural fiber composites has been conducted in the last few decades. The objective of this research is to investigate the energy absorption capacity of banana fiber polyester composite and its specific energy absorption capacity as well. Banana fibers are extracted and cut into 10mm, 20mm and 30mm fiber length. Fabrication of rectangular bar as composite samples with different banana fiber length and fiber volume fraction (1%, 2%, and 3%) were conducted and the results are studied and analyzed. The information on energy absorption and specific energy absorption capacity are useful for applications such as automotive structures where the ability to absorb impact may save life. The increase of banana fiber content and length shows an increase of maximum load and energy absorption values for all specimens.

Utilizing polypropylene fibers to improve physical and mechanical properties of concrete

The influence of polypropylene fibers has been studied in different proportioning and fiber aspect ratios to improve physical and mechanical properties of fiber-reinforced concretes. Fibers are used in two different lengths (12 mm and 19 mm) and proportions (0.1% and 0.3%) in concrete mixture design. Hardened concrete properties, such as 7- and 28-day compressive strength, splitting tensile strength, flexural strength, water and air absorption, and restrained shrinkage cracking were evaluated.No statistically significant effects were observed for polypropylene fibers on the compressive strength of concrete, while toughness indexes, splitting tensile and flexural strength and durability parameters showed an increase in the presence of polypropylene fibers. Increased fiber availability (fiber aspect ratio) in the concrete matrix, in addition to the ability of longer polypropylene fibers to bridge on the micro cracks, are suggested as the reasons for the enhancement in mechanical properties. Finally, crack width in fiber-reinforced concrete is calculated analytically with fiber property variables (fiber type, length, diameter and proportion). Results are compared with experimental values and concluded that with an increase in fiber length and/or decrease in fiber diameter crack width, decrease significantly.

Effect of the glass fiber length on the mechanical properties of long glass fiber reinforced polyphenylene sulfide

Abstract The effects of the length of glass fibers on the toughness of long glass fiber reinforced polyphenylene sulfide (PPS) composites (PPS-LFT), made by the pulltrusion process, were studied with regards to both the molding V notched specimen and the cutting V notched specimen. Toughness was excellent on the molding V notched specimen. By observing the fracture morphology of the molded V notched specimen, it was found that a crack was formed, due to a slip or debonding at the fiber surface. The crack was propagated along the fiber, due to the pulling out of fibers from the matrix polymer. Both the maximum load and the fracture energy increased with increasing length of the glass fiber, because the resistance created by pulling out the fibers increased with increasing fiber length. In the case of PPS-LFT, it is understood that toughness improved because the slip between the fiber and the resin occurs before the excessive elastic strain energy is stored.

Effect of Fiber Length on Mechanical Properties of Short Carbon Fiber Reinforced PTFE Composites

Carbon fiber reinforced composites have all the ideal properties, leading to their rapid development and successful use for many applications over the last decade. In this paper, short carbon fiber reinforced Polytetrafluoroethylene (SCF/PTFE) composite were prepared with melt blending and hot-pressing techniques. The mechanical properties of this composite were investigated taking into account the combined effect of mean fiber length. Finally it can be shown that an increase in fiber length can enhance the mechanical properties of CF/PTFE composites. The fracture surface of PTFE composite was examined by SEM, to identify the topography of outside force.

Length of Optical Fiber Influence on the Performance of Radio-over-fiber Systems

The paper investigates performance impairments due to constraints imposed by the MAC layer when optical fiber is used to extend the IEEE 802.11n network. It is shown that data throughput decreases as fiber length increases. In UDP packet transmission the maximum throughput decreases gradually by 16.6% and 18.6% for basic access and RTS/CTS, respectively. But, with considering TCP packet transmission, the reductions are 21.3% and 22% when the fiber delay increases from 0 to 22.5 μs with using basic mechanism and 0 to 18 μs with RTS/CTS one (i.e., fiber length increases from 0 to 4.3 km and 0 to 3.5 km for basic access and RTS/CTS respectively). It is also noted that the network fails long before physical layer limitations set in due to the timeout values defined within the MAC protocol.

Effects of growth on geometry of gastrocnemius muscle in children: a three-dimensional ultrasound analysis

During development, muscle growth is usually finely adapted to meet functional demands in daily activities. However, how muscle geometry changes in typically developing children and how these changes are related to functional and mechanical properties is largely unknown. In rodents, longitudinal growth of the pennate m. gastrocnemius medialis (GM) has been shown to occur mainly by an increase in physiological cross-sectional area and less by an increase in fibre length. Therefore, we aimed to: (i) determine how geometry of GM changes in healthy children between the ages of 5 and 12 years, (ii) test whether GM geometry in these children is affected by gender, (iii) compare normalized growth of GM geometry in children with that in rats at similar normalized ages, and (iv) investigate how GM geometry in children relates to range of motion of angular foot movement at a given moment. Thirty children (16 females, 14 males) participated in the study. Moment-angle data were collected over a range of angles by rotating the foot from plantar flexion to dorsal flexion at standardized moments. GM geometry in the mid-longitudinal plane was measured using three-dimensional ultrasound imaging. This geometry was compared with that of GM geometry in rats. During growth from 5 to 12 years of age, the mean neutral footplate angle (0 Nm) occurred at -5° (SD 7°) and was not a function of age. Measured at standardized moments (4 Nm), footplate angles towards plantar flexion and dorsal flexion decreased by 25 and 40%, respectively. In both rats and children, GM muscle length increased proportionally with tibia length. In children, the length component of the physiological cross-sectional area and fascicle length increased by 7 and 5% per year, respectively. Fascicle angle did not change over the age range measured. In children, the Achilles tendon length increased by 6% per year. GM geometry was not affected by gender. We conclude that, whereas the length of GM in rat develops mainly by an increase in physiological cross-sectional area of the muscle, GM in children develops by uniform scaling of the muscle. This effect is probably related to the smaller fascicle angle in human GM, which entails a smaller contribution of radial muscle growth to increased GM muscle length. The net effect of uniform scaling of GM muscle belly causes it to be stiffer, explaining the decrease in range of motion of angular foot movement at 4 Nm towards dorsal flexion during growth.

Effect of Span Length on the Tensile Properties of Natural Fibers

Natural fibers are widely used as “reinforcing agents” in polymer composites. The aim of the current study is to evaluate the effect of span length on the tensile properties of several natural fibers (Vietnamese coir and bamboo and Bangladeshi jute). Tensile testing of jute, bamboo and coir fibers was carried out by varying span length (5, 10, 15, 25 and 35 mm). The Young’s modulus and strain to failure were corrected by using newly developed analytical equations in order to correlate the Young’s modulus and strain to failure of natural fibers. Scanning electron microscopy of the fibers was also carried out. It is clearly observed that the Young’s modulus increased with an increase in span length. Whereas tensile strength and strain to failure decreased with an increase in the span length of single fibers. The correction method resulted in a high Young’s modulus for larger span, while strain to failure found was lower compared to smaller span. This is because larger span length helps to minimize the machine displacement compared to smaller ones. Among all fibers, the Young’s modulus of bamboo fiber was highest, followed by jute and coir respectively. Jute fiber had smoother surface and compact structure compared to other two fibers.

SHORT INTERNODES‐like genes regulate shoot growth and xylem proliferation in Populus

• Genes controlling plant growth and form are of considerable interest, because they affect survival and productivity traits, and are largely unknown or poorly characterized. The SHORT INTERNODES(SHI) gene is one of a 10-member SHI-RELATED SEQUENCE (SRS) gene family in Arabidopsis that includes important developmental regulators. • Using comparative sequence analysis of the SRS gene families in poplar and Arabidopsis, we identified two poplar proteins that are most similar to SHI and its closely related gene STYLISH1 (STY1). The two poplar genes are very similar in sequence and expression and are therefore probably paralogs with redundant functions. • RNAi suppression of the two Populus genes enhanced shoot and root growth, whereas the overexpression of Arabidopsis SHI in poplar reduced internode and petiole length. The suppression of the two genes increased fiber length and the proportion of xylem tissue, mainly through increased xylem cell proliferation. The transgenic modifications were also associated with significant changes in the concentrations of gibberellins and cytokinin. • We conclude that Populus SHI-RELATED SEQUENCE (SRS) genes play an important role in the regulation of vegetative growth, including wood formation, and thus could be useful tools for the modification of biomass productivity, wood quality or plant form.

Studying the effect of fiber size and fiber loading on the mechanical properties of hybridized kenaf/PALF-reinforced HDPE composite

Hybridization, especially where only variant natural lignocelluloses are combined, is fast receiving encouraging attention because it offers a range of properties that may be difficult to obtain with a single kind of reinforcement. In this study, tensile, flexural, and impact properties of hybridized kenaf/PALF-reinforced HDPE composite were studied. Sheets from which tensile, flexural, and impact specimens were cut out were produced from the compression molding of composite pellets and subsequently conditioned in an oven for 21 h at 103°C. The tensile and flexural specimens were tested according to ASTM D638 and ASTM D790 using a 5-kN INSTRON bluehill universal testing machine accordingly. While a notched Izoid impact test was conducted using a 1-J universal pendulum according to ASTM D256. All specimens were prepared at a fiber ratio of 1:1 kenaf:PALF and fiber lengths of 0.25, 0.5, 0.75, and 2 mm; fiber loadings of between 10% and 70% were utilized for the study. About 0.25 mm fiber showed the best tensile and flexural properties with a linear increase in properties up to 60% fiber loading while impact strength showed better property with 0.75 and 2 mm fiber lengths. At 0.25 mm fiber length, tensile strength of 32.24 MPa, flexural strength and modulus of 34.01 MPa and 4114.11 MPa, respectively, were observed at 60% fiber loading. Moduli results of all the composites formulated generally obeyed the ROM. SEM was used to examine the surface of composites produced. Tensile and impact strengths result showed inverse proportionality while flexural strength of the composite generally adhered to the ROM. However, a positive effect was observed in the case of composite’s impact strength in respect of increasing fiber length. Thus, reduction in some mechanical properties of the composite with respect to increasing fiber length is attributed more to fiber entanglement rather than attrition.

Effects of Irrigation, Cultivar, and Plant Density on Cotton Within‐Boll Fiber Quality

This study was designed to determine how within‐boll fiber quality of cotton (Gossypium hirsutum L.) is affected through irrigation, cultivar, and plant density management. Field experiments were conducted in 2006 and 2007 using two contemporary cultivars, arranged in a split‐split plot design with two irrigation rates (6.33 and 4.32 mm d−1) as the main plot, plant density (79,071; 128,490; 197,677 plants ha−1) as the subplot, and cotton cultivar (FM9063B2RF and ST4554B2RF) as the subsubplot. Plants from 3 m of one row from each plot were hand harvested by fruiting position. First fruiting position bolls from main‐stem nodes 9 and 14 were hand harvested by seed position and ginned separately for Advanced Fiber Information System (AFIS) fiber quality analysis. Increased irrigation generally increased fiber length and upper quartile length, and decreased fineness and maturity ratio. Irrigation effects were greater on fiber length and maturity ratio at seed positions close to the apex of the locule. Increased plant density reduced both fineness and maturity ratio. The cultivar FM9063B2RF produced longer, more mature, and finer fibers than the ST4554B2RF. The overall lowest fiber quality (i.e., shorter and less mature fibers) occurred at seed positions close to the apex of the locule. The superior fiber quality (i.e., longer and more mature fibers) was from the middle to the base of the locule. Abundant rainfall diminished the effects of irrigation on fiber quality.

Effect of Fibre Size and Fibre Loading on Tensile Properties of Hybridized Kenaf/PALF Reinforced HDPE Composite

Hybridization, especially where only variant natural lignocelluloses are combined, is fast receiving encouraging attention because it offers range of properties that are quite difficult to obtain with a single kind of reinforcement. In this work, tensile strength and modulus of hybridized kenaf/PALF reinforced HDPE composite was examined. Pellets were produced form the mixture of the composite in an internal mixer at 190oC, 40rpm and 25minutes for processing temperature, speed and duration of mixing respectively. The composite sheets with thickness of 1mm produced from pellets were prepared using compression moulding. Then the tensile specimen were prepared and tested using an INSTRON bluehill universal testing machine according to ASTM D638 requirements. All samples were prepared at 1:1 kenaf:PALF ratio; ≤0.25mm and ≤0.5mm fibre length; fiber loading of 10 to 40% were utilized. Linear relationship of tensile modulus was observed with about 26% reduction in tensile strength at 10% fibre loading that subsequently reduced but with a reversal increase at 40% fibre loading. This was attributed to a better supportive load at that fibre content and a better interaction between fibre and matrix. Furthermore, the result also corroborates with the one obtained for the tensile modulus at same fibre loading. The best tensile strength and tensile modulus obtained was 32.43MPa;642.61MPa and 30.01MPa;636.73MPa for 0.25mm and 0.5mm fibre length respectively. Increase in fibre length did not show any significant improvement in tensile strength which may have been coursed by fibre attrition. It is possible to achieve improved mechanical properties if the fibres are given some kind of treatment.

Effect of short, randomly distributed polypropylene microfibres on shear strength behaviour of soils

ABSTRACT: An experimental programme was carried out on the shear strength behaviour of sandy and clayey soils reinforced with short, randomly distributed, polypropylene (PP) microfibres. The influence of fibre texture, fibre content, fibre length and normal stress level was investigated by means of direct shear tests. The best procedure to mix the soil with the fibres in order to achieve homogeneous and isotropic samples is described. This study shows that fibres increase the shear strength and significantly modify the shear stress displacement behaviour of the tested soils. Shear strength increases with increase in fibre content, fibre length and displacement. No appreciable advantage is achieved by using crimped (texturised) fibres as far as shear strength is concerned. Furthermore, mixture is achieved with greater difficulty when compared with straight fibres. There is an increase in both the apparent cohesion and the angle of shearing resistance of soils, owing to the short PP microfibres. The fibre contribution is especially significant for low normal stress levels. Despite the occurrence of some fibre damage, damaged fibres are still suitable for reinforcement.

Modality-Specific Axonal Regeneration: Toward Selective Regenerative Neural Interfaces

Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control of robotic prosthetic devices. However, sensory and motor axons at the neural interface are of mixed sub-modality types, which difficult the specific recording from motor axons and the eliciting of precise sensory modalities through selective stimulation. Here we evaluated the possibility of using type specific neurotrophins to preferentially entice the regeneration of defined axonal populations from transected peripheral nerves into separate compartments. Segregation of mixed sensory fibers from dorsal root ganglion neurons was evaluated in vitro by compartmentalized diffusion delivery of nerve growth factor (NGF) and neurotrophin-3 (NT-3), to preferentially entice the growth of TrkA+ nociceptive and TrkC+ proprioceptive subsets of sensory neurons, respectively. The average axon length in the NGF channel increased 2.5-fold compared to that in saline or NT-3, whereas the number of branches increased threefold in the NT-3 channels. These results were confirmed using a 3D “Y”-shaped in vitro assay showing that the arm containing NGF was able to entice a fivefold increase in axonal length of unbranched fibers. To address if such segregation can be enticed in vivo, a “Y”-shaped tubing was used to allow regeneration of the transected adult rat sciatic nerve into separate compartments filled with either NFG or NT-3. A significant increase in the number of CGRP+ pain fibers were attracted toward the sural nerve, while N-52+ large-diameter axons were observed in the tibial and NT-3 compartments. This study demonstrates the guided enrichment of sensory axons in specific regenerative chambers, and supports the notion that neurotrophic factors can be used to segregate sensory and perhaps motor axons in separate peripheral interfaces.

Topiramate improves neurovascular function, epidermal nerve fiber morphology, and metabolism in patients with type 2 diabetes mellitus

Topiramate improves neurovascular function, epidermal nerve fiber morphology, and metabolism in patients with type 2 diabetes mellitus Amanda L Boyd, Patricia M Barlow, Gary L Pittenger, Kathryn F Simmons, Aaron I VinikDepartment of Internal Medicine, Eastern Virginia Medical School, Norfolk, VA, USAPurpose: To assess the effects of topiramate on C-fiber function, nerve fiber morphology, and metabolism (including insulin sensitivity, obesity, and dyslipidemia) in type 2 diabetes.Patients and methods: We conducted an 18-week, open-label trial treating patients with topiramate. Twenty subjects with type 2 diabetes and neuropathy (61.5 ± 1.29 years; 15 male, 5 female) were enrolled and completed the trial. Neuropathy was evaluated by total neuropathy scores, nerve conduction studies, quantitative sensory tests, laser Doppler skin blood flow, and intraepidermal nerve fibers in skin biopsies.Results: Topiramate treatment improved symptoms compatible with C-fiber dysfunction. Weight, blood pressure, and hemoglobin A1c also improved. Laser Doppler skin blood flow improved significantly after 12 weeks of treatment, but returned to baseline at 18 weeks. After 18 weeks of treatment there was a significant increase in intraepidermal nerve fiber length at the forearm, thigh, and proximal leg. Intraepidermal nerve fiber density was significantly increased by topiramate in the proximal leg.Conclusion: This study is the first to demonstrate that it is possible to induce skin intraepidermal nerve fiber regeneration accompanied by enhancement of neurovascular function, translating into improved symptoms as well as sensory nerve function. The simultaneous improvement of selective metabolic indices may play a role in this effect, but this remains to be determined.Keywords: diabetic neuropathy, skin blood flow, skin biopsy, diabetes

Topiramate improves neurovascular function, epidermal nerve fiber morphology, and metabolism in patients with type 2 diabetes mellitus.

PurposeTo assess the effects of topiramate on C-fiber function, nerve fiber morphology, and metabolism (including insulin sensitivity, obesity, and dyslipidemia) in type 2 diabetes.Patients and methodsWe conducted an 18-week, open-label trial treating patients with topiramate. Twenty subjects with type 2 diabetes and neuropathy (61.5 ± 1.29 years; 15 male, 5 female) were enrolled and completed the trial. Neuropathy was evaluated by total neuropathy scores, nerve conduction studies, quantitative sensory tests, laser Doppler skin blood flow, and intraepidermal nerve fibers in skin biopsies.ResultsTopiramate treatment improved symptoms compatible with C-fiber dysfunction. Weight, blood pressure, and hemoglobin A1c also improved. Laser Doppler skin blood flow improved significantly after 12 weeks of treatment, but returned to baseline at 18 weeks. After 18 weeks of treatment there was a significant increase in intraepidermal nerve fiber length at the forearm, thigh, and proximal leg. Intraepidermal nerve fiber density was significantly increased by topiramate in the proximal leg.ConclusionThis study is the first to demonstrate that it is possible to induce skin intraepidermal nerve fiber regeneration accompanied by enhancement of neurovascular function, translating into improved symptoms as well as sensory nerve function. The simultaneous improvement of selective metabolic indices may play a role in this effect, but this remains to be determined.